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* [PATCH net-next v2 5/8] sctp: move flushing of data chunks out of sctp_outq_flush
From: Marcelo Ricardo Leitner @ 2018-05-12 22:21 UTC (permalink / raw)
  To: netdev; +Cc: linux-sctp, Neil Horman, Vlad Yasevich, Xin Long
In-Reply-To: <cover.1526142784.git.marcelo.leitner@gmail.com>

To the new sctp_outq_flush_data. Again, smaller functions and with well
defined objectives.

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
---
 net/sctp/outqueue.c | 148 ++++++++++++++++++++++++++--------------------------
 1 file changed, 75 insertions(+), 73 deletions(-)

diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c
index 6d7ee372a9d6b8e68a759277830d5334ec992d47..7522188107792643f3bb5f00e5c254b00e91ef12 100644
--- a/net/sctp/outqueue.c
+++ b/net/sctp/outqueue.c
@@ -1038,45 +1038,17 @@ static bool sctp_outq_flush_rtx(struct sctp_outq *q,
 
 	return true;
 }
-/*
- * Try to flush an outqueue.
- *
- * Description: Send everything in q which we legally can, subject to
- * congestion limitations.
- * * Note: This function can be called from multiple contexts so appropriate
- * locking concerns must be made.  Today we use the sock lock to protect
- * this function.
- */
-static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
+
+static void sctp_outq_flush_data(struct sctp_outq *q,
+				 struct sctp_transport **_transport,
+				 struct list_head *transport_list,
+				 int rtx_timeout, gfp_t gfp)
 {
-	struct sctp_packet *packet;
+	struct sctp_transport *transport = *_transport;
+	struct sctp_packet *packet = transport ? &transport->packet : NULL;
 	struct sctp_association *asoc = q->asoc;
-	struct sctp_transport *transport = NULL;
 	struct sctp_chunk *chunk;
 	enum sctp_xmit status;
-	int error = 0;
-
-	/* These transports have chunks to send. */
-	struct list_head transport_list;
-	struct list_head *ltransport;
-
-	INIT_LIST_HEAD(&transport_list);
-	packet = NULL;
-
-	/*
-	 * 6.10 Bundling
-	 *   ...
-	 *   When bundling control chunks with DATA chunks, an
-	 *   endpoint MUST place control chunks first in the outbound
-	 *   SCTP packet.  The transmitter MUST transmit DATA chunks
-	 *   within a SCTP packet in increasing order of TSN.
-	 *   ...
-	 */
-
-	sctp_outq_flush_ctrl(q, &transport, &transport_list, gfp);
-
-	if (q->asoc->src_out_of_asoc_ok)
-		goto sctp_flush_out;
 
 	/* Is it OK to send data chunks?  */
 	switch (asoc->state) {
@@ -1101,10 +1073,11 @@ static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
 		 * current cwnd).
 		 */
 		if (!list_empty(&q->retransmit)) {
-			if (!sctp_outq_flush_rtx(q, &transport, &transport_list,
+			if (!sctp_outq_flush_rtx(q, _transport, transport_list,
 						 rtx_timeout))
 				break;
 			/* We may have switched current transport */
+			transport = *_transport;
 			packet = &transport->packet;
 		}
 
@@ -1130,12 +1103,14 @@ static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
 
 			if (asoc->stream.out[sid].state == SCTP_STREAM_CLOSED) {
 				sctp_outq_head_data(q, chunk);
-				goto sctp_flush_out;
+				break;
 			}
 
-			if (sctp_outq_select_transport(chunk, asoc, &transport,
-						       &transport_list))
+			if (sctp_outq_select_transport(chunk, asoc, _transport,
+						       transport_list)) {
+				transport = *_transport;
 				packet = &transport->packet;
+			}
 
 			pr_debug("%s: outq:%p, chunk:%p[%s], tx-tsn:0x%x skb->head:%p "
 				 "skb->users:%d\n",
@@ -1147,8 +1122,10 @@ static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
 
 			/* Add the chunk to the packet.  */
 			status = sctp_packet_transmit_chunk(packet, chunk, 0, gfp);
-
 			switch (status) {
+			case SCTP_XMIT_OK:
+				break;
+
 			case SCTP_XMIT_PMTU_FULL:
 			case SCTP_XMIT_RWND_FULL:
 			case SCTP_XMIT_DELAY:
@@ -1160,41 +1137,25 @@ static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
 					 status);
 
 				sctp_outq_head_data(q, chunk);
-				goto sctp_flush_out;
-
-			case SCTP_XMIT_OK:
-				/* The sender is in the SHUTDOWN-PENDING state,
-				 * The sender MAY set the I-bit in the DATA
-				 * chunk header.
-				 */
-				if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING)
-					chunk->chunk_hdr->flags |= SCTP_DATA_SACK_IMM;
-				if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
-					asoc->stats.ouodchunks++;
-				else
-					asoc->stats.oodchunks++;
-
-				/* Only now it's safe to consider this
-				 * chunk as sent, sched-wise.
-				 */
-				sctp_sched_dequeue_done(q, chunk);
-
-				break;
-
-			default:
-				BUG();
+				return;
 			}
 
-			/* BUG: We assume that the sctp_packet_transmit()
-			 * call below will succeed all the time and add the
-			 * chunk to the transmitted list and restart the
-			 * timers.
-			 * It is possible that the call can fail under OOM
-			 * conditions.
-			 *
-			 * Is this really a problem?  Won't this behave
-			 * like a lost TSN?
+			/* The sender is in the SHUTDOWN-PENDING state,
+			 * The sender MAY set the I-bit in the DATA
+			 * chunk header.
 			 */
+			if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING)
+				chunk->chunk_hdr->flags |= SCTP_DATA_SACK_IMM;
+			if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
+				asoc->stats.ouodchunks++;
+			else
+				asoc->stats.oodchunks++;
+
+			/* Only now it's safe to consider this
+			 * chunk as sent, sched-wise.
+			 */
+			sctp_sched_dequeue_done(q, chunk);
+
 			list_add_tail(&chunk->transmitted_list,
 				      &transport->transmitted);
 
@@ -1205,7 +1166,7 @@ static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
 			 * COOKIE-ECHO chunk.
 			 */
 			if (packet->has_cookie_echo)
-				goto sctp_flush_out;
+				break;
 		}
 		break;
 
@@ -1213,6 +1174,47 @@ static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
 		/* Do nothing.  */
 		break;
 	}
+}
+
+/*
+ * Try to flush an outqueue.
+ *
+ * Description: Send everything in q which we legally can, subject to
+ * congestion limitations.
+ * * Note: This function can be called from multiple contexts so appropriate
+ * locking concerns must be made.  Today we use the sock lock to protect
+ * this function.
+ */
+static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
+{
+	struct sctp_packet *packet;
+	struct sctp_association *asoc = q->asoc;
+	struct sctp_transport *transport = NULL;
+	int error = 0;
+
+	/* These transports have chunks to send. */
+	struct list_head transport_list;
+	struct list_head *ltransport;
+
+	INIT_LIST_HEAD(&transport_list);
+	packet = NULL;
+
+	/*
+	 * 6.10 Bundling
+	 *   ...
+	 *   When bundling control chunks with DATA chunks, an
+	 *   endpoint MUST place control chunks first in the outbound
+	 *   SCTP packet.  The transmitter MUST transmit DATA chunks
+	 *   within a SCTP packet in increasing order of TSN.
+	 *   ...
+	 */
+
+	sctp_outq_flush_ctrl(q, &transport, &transport_list, gfp);
+
+	if (q->asoc->src_out_of_asoc_ok)
+		goto sctp_flush_out;
+
+	sctp_outq_flush_data(q, &transport, &transport_list, rtx_timeout, gfp);
 
 sctp_flush_out:
 
-- 
2.14.3

^ permalink raw reply related

* [PATCH net-next v2 4/8] sctp: move outq data rtx code out of sctp_outq_flush
From: Marcelo Ricardo Leitner @ 2018-05-12 22:21 UTC (permalink / raw)
  To: netdev; +Cc: linux-sctp, Neil Horman, Vlad Yasevich, Xin Long
In-Reply-To: <cover.1526142784.git.marcelo.leitner@gmail.com>

This patch renames current sctp_outq_flush_rtx to __sctp_outq_flush_rtx
and create a new sctp_outq_flush_rtx, with the code that was on
sctp_outq_flush. Again, the idea is to have functions with small and
defined objectives.

Yes, there is an open-coded path selection in the now sctp_outq_flush_rtx.
That is kept as is for now because it may be very different when we
implement retransmission path selection algorithms for CMT-SCTP.

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
---
 net/sctp/outqueue.c | 101 ++++++++++++++++++++++++++++++----------------------
 1 file changed, 58 insertions(+), 43 deletions(-)

diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c
index 800202c68cb89f1086ee7d3a4493dc752c8bf6ac..6d7ee372a9d6b8e68a759277830d5334ec992d47 100644
--- a/net/sctp/outqueue.c
+++ b/net/sctp/outqueue.c
@@ -601,14 +601,14 @@ void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
 
 /*
  * Transmit DATA chunks on the retransmit queue.  Upon return from
- * sctp_outq_flush_rtx() the packet 'pkt' may contain chunks which
+ * __sctp_outq_flush_rtx() the packet 'pkt' may contain chunks which
  * need to be transmitted by the caller.
  * We assume that pkt->transport has already been set.
  *
  * The return value is a normal kernel error return value.
  */
-static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt,
-			       int rtx_timeout, int *start_timer)
+static int __sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt,
+				 int rtx_timeout, int *start_timer)
 {
 	struct sctp_transport *transport = pkt->transport;
 	struct sctp_chunk *chunk, *chunk1;
@@ -987,6 +987,57 @@ static void sctp_outq_flush_ctrl(struct sctp_outq *q,
 	}
 }
 
+/* Returns false if new data shouldn't be sent */
+static bool sctp_outq_flush_rtx(struct sctp_outq *q,
+				struct sctp_transport **_transport,
+				struct list_head *transport_list,
+				int rtx_timeout)
+{
+	struct sctp_transport *transport = *_transport;
+	struct sctp_packet *packet = transport ? &transport->packet : NULL;
+	struct sctp_association *asoc = q->asoc;
+	int error, start_timer = 0;
+
+	if (asoc->peer.retran_path->state == SCTP_UNCONFIRMED)
+		return false;
+
+	if (transport != asoc->peer.retran_path) {
+		/* Switch transports & prepare the packet.  */
+		transport = asoc->peer.retran_path;
+		*_transport = transport;
+
+		if (list_empty(&transport->send_ready))
+			list_add_tail(&transport->send_ready,
+				      transport_list);
+
+		packet = &transport->packet;
+		sctp_packet_config(packet, asoc->peer.i.init_tag,
+				   asoc->peer.ecn_capable);
+	}
+
+	error = __sctp_outq_flush_rtx(q, packet, rtx_timeout, &start_timer);
+	if (error < 0)
+		asoc->base.sk->sk_err = -error;
+
+	if (start_timer) {
+		sctp_transport_reset_t3_rtx(transport);
+		transport->last_time_sent = jiffies;
+	}
+
+	/* This can happen on COOKIE-ECHO resend.  Only
+	 * one chunk can get bundled with a COOKIE-ECHO.
+	 */
+	if (packet->has_cookie_echo)
+		return false;
+
+	/* Don't send new data if there is still data
+	 * waiting to retransmit.
+	 */
+	if (!list_empty(&q->retransmit))
+		return false;
+
+	return true;
+}
 /*
  * Try to flush an outqueue.
  *
@@ -1000,12 +1051,10 @@ static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
 {
 	struct sctp_packet *packet;
 	struct sctp_association *asoc = q->asoc;
-	__u32 vtag = asoc->peer.i.init_tag;
 	struct sctp_transport *transport = NULL;
 	struct sctp_chunk *chunk;
 	enum sctp_xmit status;
 	int error = 0;
-	int start_timer = 0;
 
 	/* These transports have chunks to send. */
 	struct list_head transport_list;
@@ -1052,45 +1101,11 @@ static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
 		 * current cwnd).
 		 */
 		if (!list_empty(&q->retransmit)) {
-			if (asoc->peer.retran_path->state == SCTP_UNCONFIRMED)
-				goto sctp_flush_out;
-			if (transport == asoc->peer.retran_path)
-				goto retran;
-
-			/* Switch transports & prepare the packet.  */
-
-			transport = asoc->peer.retran_path;
-
-			if (list_empty(&transport->send_ready)) {
-				list_add_tail(&transport->send_ready,
-					      &transport_list);
-			}
-
+			if (!sctp_outq_flush_rtx(q, &transport, &transport_list,
+						 rtx_timeout))
+				break;
+			/* We may have switched current transport */
 			packet = &transport->packet;
-			sctp_packet_config(packet, vtag,
-					   asoc->peer.ecn_capable);
-		retran:
-			error = sctp_outq_flush_rtx(q, packet,
-						    rtx_timeout, &start_timer);
-			if (error < 0)
-				asoc->base.sk->sk_err = -error;
-
-			if (start_timer) {
-				sctp_transport_reset_t3_rtx(transport);
-				transport->last_time_sent = jiffies;
-			}
-
-			/* This can happen on COOKIE-ECHO resend.  Only
-			 * one chunk can get bundled with a COOKIE-ECHO.
-			 */
-			if (packet->has_cookie_echo)
-				goto sctp_flush_out;
-
-			/* Don't send new data if there is still data
-			 * waiting to retransmit.
-			 */
-			if (!list_empty(&q->retransmit))
-				goto sctp_flush_out;
 		}
 
 		/* Apply Max.Burst limitation to the current transport in
-- 
2.14.3

^ permalink raw reply related

* [PATCH net-next v2 3/8] sctp: move the flush of ctrl chunks into its own function
From: Marcelo Ricardo Leitner @ 2018-05-12 22:21 UTC (permalink / raw)
  To: netdev; +Cc: linux-sctp, Neil Horman, Vlad Yasevich, Xin Long
In-Reply-To: <cover.1526142784.git.marcelo.leitner@gmail.com>

Named sctp_outq_flush_ctrl and, with that, keep the contexts contained.

One small fix embedded is the reset of one_packet at every iteration.
This allows bundling of some control chunks in case they were preceded by
another control chunk that cannot be bundled.

Other than this, it has the same behavior.

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
---
 net/sctp/outqueue.c | 89 ++++++++++++++++++++++++++++++++---------------------
 1 file changed, 54 insertions(+), 35 deletions(-)

diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c
index bda50596d4bfebeac03966c5a161473df1c1986a..800202c68cb89f1086ee7d3a4493dc752c8bf6ac 100644
--- a/net/sctp/outqueue.c
+++ b/net/sctp/outqueue.c
@@ -875,45 +875,21 @@ static bool sctp_outq_select_transport(struct sctp_chunk *chunk,
 	return changed;
 }

-/*
- * Try to flush an outqueue.
- *
- * Description: Send everything in q which we legally can, subject to
- * congestion limitations.
- * * Note: This function can be called from multiple contexts so appropriate
- * locking concerns must be made.  Today we use the sock lock to protect
- * this function.
- */
-static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
+static void sctp_outq_flush_ctrl(struct sctp_outq *q,
+				 struct sctp_transport **_transport,
+				 struct list_head *transport_list,
+				 gfp_t gfp)
 {
-	struct sctp_packet *packet;
+	struct sctp_transport *transport = *_transport;
 	struct sctp_association *asoc = q->asoc;
-	__u32 vtag = asoc->peer.i.init_tag;
-	struct sctp_transport *transport = NULL;
+	struct sctp_packet *packet = NULL;
 	struct sctp_chunk *chunk, *tmp;
 	enum sctp_xmit status;
-	int error = 0;
-	int start_timer = 0;
-	int one_packet = 0;
-
-	/* These transports have chunks to send. */
-	struct list_head transport_list;
-	struct list_head *ltransport;
-
-	INIT_LIST_HEAD(&transport_list);
-	packet = NULL;
-
-	/*
-	 * 6.10 Bundling
-	 *   ...
-	 *   When bundling control chunks with DATA chunks, an
-	 *   endpoint MUST place control chunks first in the outbound
-	 *   SCTP packet.  The transmitter MUST transmit DATA chunks
-	 *   within a SCTP packet in increasing order of TSN.
-	 *   ...
-	 */
+	int one_packet, error;

 	list_for_each_entry_safe(chunk, tmp, &q->control_chunk_list, list) {
+		one_packet = 0;
+
 		/* RFC 5061, 5.3
 		 * F1) This means that until such time as the ASCONF
 		 * containing the add is acknowledged, the sender MUST
@@ -930,8 +906,10 @@ static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
 		 * the first chunk as we don't have a transport by then.
 		 */
 		if (sctp_outq_select_transport(chunk, asoc, &transport,
-					       &transport_list))
+					       transport_list)) {
+			transport = *_transport;
 			packet = &transport->packet;
+		}

 		switch (chunk->chunk_hdr->type) {
 		/*
@@ -954,6 +932,7 @@ static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
 			if (sctp_test_T_bit(chunk))
 				packet->vtag = asoc->c.my_vtag;
 			/* fallthru */
+
 		/* The following chunks are "response" chunks, i.e.
 		 * they are generated in response to something we
 		 * received.  If we are sending these, then we can
@@ -979,7 +958,7 @@ static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
 		case SCTP_CID_RECONF:
 			status = sctp_packet_transmit_chunk(packet, chunk,
 							    one_packet, gfp);
-			if (status  != SCTP_XMIT_OK) {
+			if (status != SCTP_XMIT_OK) {
 				/* put the chunk back */
 				list_add(&chunk->list, &q->control_chunk_list);
 				break;
@@ -1006,6 +985,46 @@ static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
 			BUG();
 		}
 	}
+}
+
+/*
+ * Try to flush an outqueue.
+ *
+ * Description: Send everything in q which we legally can, subject to
+ * congestion limitations.
+ * * Note: This function can be called from multiple contexts so appropriate
+ * locking concerns must be made.  Today we use the sock lock to protect
+ * this function.
+ */
+static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
+{
+	struct sctp_packet *packet;
+	struct sctp_association *asoc = q->asoc;
+	__u32 vtag = asoc->peer.i.init_tag;
+	struct sctp_transport *transport = NULL;
+	struct sctp_chunk *chunk;
+	enum sctp_xmit status;
+	int error = 0;
+	int start_timer = 0;
+
+	/* These transports have chunks to send. */
+	struct list_head transport_list;
+	struct list_head *ltransport;
+
+	INIT_LIST_HEAD(&transport_list);
+	packet = NULL;
+
+	/*
+	 * 6.10 Bundling
+	 *   ...
+	 *   When bundling control chunks with DATA chunks, an
+	 *   endpoint MUST place control chunks first in the outbound
+	 *   SCTP packet.  The transmitter MUST transmit DATA chunks
+	 *   within a SCTP packet in increasing order of TSN.
+	 *   ...
+	 */
+
+	sctp_outq_flush_ctrl(q, &transport, &transport_list, gfp);

 	if (q->asoc->src_out_of_asoc_ok)
 		goto sctp_flush_out;

^ permalink raw reply related

* [PATCH net-next v2 2/8] sctp: factor out sctp_outq_select_transport
From: Marcelo Ricardo Leitner @ 2018-05-12 22:20 UTC (permalink / raw)
  To: netdev; +Cc: linux-sctp, Neil Horman, Vlad Yasevich, Xin Long
In-Reply-To: <cover.1526142784.git.marcelo.leitner@gmail.com>

We had two spots doing such complex operation and they were very close to
each other, a bit more tailored to here or there.

This patch unifies these under the same function,
sctp_outq_select_transport, which knows how to handle control chunks and
original transmissions (but not retransmissions).

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
---
 net/sctp/outqueue.c | 187 +++++++++++++++++++++++++---------------------------
 1 file changed, 90 insertions(+), 97 deletions(-)

diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c
index 300bd0dfc7c14c9df579dbe2f9e78dd8356ae1a3..bda50596d4bfebeac03966c5a161473df1c1986a 100644
--- a/net/sctp/outqueue.c
+++ b/net/sctp/outqueue.c
@@ -791,6 +791,90 @@ static int sctp_packet_singleton(struct sctp_transport *transport,
 	return sctp_packet_transmit(&singleton, gfp);
 }
 
+static bool sctp_outq_select_transport(struct sctp_chunk *chunk,
+				       struct sctp_association *asoc,
+				       struct sctp_transport **transport,
+				       struct list_head *transport_list)
+{
+	struct sctp_transport *new_transport = chunk->transport;
+	struct sctp_transport *curr = *transport;
+	bool changed = false;
+
+	if (!new_transport) {
+		if (!sctp_chunk_is_data(chunk)) {
+			/*
+			 * If we have a prior transport pointer, see if
+			 * the destination address of the chunk
+			 * matches the destination address of the
+			 * current transport.  If not a match, then
+			 * try to look up the transport with a given
+			 * destination address.  We do this because
+			 * after processing ASCONFs, we may have new
+			 * transports created.
+			 */
+			if (curr && sctp_cmp_addr_exact(&chunk->dest,
+							&curr->ipaddr))
+				new_transport = curr;
+			else
+				new_transport = sctp_assoc_lookup_paddr(asoc,
+								  &chunk->dest);
+		}
+
+		/* if we still don't have a new transport, then
+		 * use the current active path.
+		 */
+		if (!new_transport)
+			new_transport = asoc->peer.active_path;
+	} else {
+		__u8 type;
+
+		switch (new_transport->state) {
+		case SCTP_INACTIVE:
+		case SCTP_UNCONFIRMED:
+		case SCTP_PF:
+			/* If the chunk is Heartbeat or Heartbeat Ack,
+			 * send it to chunk->transport, even if it's
+			 * inactive.
+			 *
+			 * 3.3.6 Heartbeat Acknowledgement:
+			 * ...
+			 * A HEARTBEAT ACK is always sent to the source IP
+			 * address of the IP datagram containing the
+			 * HEARTBEAT chunk to which this ack is responding.
+			 * ...
+			 *
+			 * ASCONF_ACKs also must be sent to the source.
+			 */
+			type = chunk->chunk_hdr->type;
+			if (type != SCTP_CID_HEARTBEAT &&
+			    type != SCTP_CID_HEARTBEAT_ACK &&
+			    type != SCTP_CID_ASCONF_ACK)
+				new_transport = asoc->peer.active_path;
+			break;
+		default:
+			break;
+		}
+	}
+
+	/* Are we switching transports? Take care of transport locks. */
+	if (new_transport != curr) {
+		changed = true;
+		curr = new_transport;
+		*transport = curr;
+		if (list_empty(&curr->send_ready))
+			list_add_tail(&curr->send_ready, transport_list);
+
+		sctp_packet_config(&curr->packet, asoc->peer.i.init_tag,
+				   asoc->peer.ecn_capable);
+		/* We've switched transports, so apply the
+		 * Burst limit to the new transport.
+		 */
+		sctp_transport_burst_limited(curr);
+	}
+
+	return changed;
+}
+
 /*
  * Try to flush an outqueue.
  *
@@ -806,7 +890,6 @@ static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
 	struct sctp_association *asoc = q->asoc;
 	__u32 vtag = asoc->peer.i.init_tag;
 	struct sctp_transport *transport = NULL;
-	struct sctp_transport *new_transport;
 	struct sctp_chunk *chunk, *tmp;
 	enum sctp_xmit status;
 	int error = 0;
@@ -843,68 +926,12 @@ static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
 
 		list_del_init(&chunk->list);
 
-		/* Pick the right transport to use. */
-		new_transport = chunk->transport;
-
-		if (!new_transport) {
-			/*
-			 * If we have a prior transport pointer, see if
-			 * the destination address of the chunk
-			 * matches the destination address of the
-			 * current transport.  If not a match, then
-			 * try to look up the transport with a given
-			 * destination address.  We do this because
-			 * after processing ASCONFs, we may have new
-			 * transports created.
-			 */
-			if (transport &&
-			    sctp_cmp_addr_exact(&chunk->dest,
-						&transport->ipaddr))
-					new_transport = transport;
-			else
-				new_transport = sctp_assoc_lookup_paddr(asoc,
-								&chunk->dest);
-
-			/* if we still don't have a new transport, then
-			 * use the current active path.
-			 */
-			if (!new_transport)
-				new_transport = asoc->peer.active_path;
-		} else if ((new_transport->state == SCTP_INACTIVE) ||
-			   (new_transport->state == SCTP_UNCONFIRMED) ||
-			   (new_transport->state == SCTP_PF)) {
-			/* If the chunk is Heartbeat or Heartbeat Ack,
-			 * send it to chunk->transport, even if it's
-			 * inactive.
-			 *
-			 * 3.3.6 Heartbeat Acknowledgement:
-			 * ...
-			 * A HEARTBEAT ACK is always sent to the source IP
-			 * address of the IP datagram containing the
-			 * HEARTBEAT chunk to which this ack is responding.
-			 * ...
-			 *
-			 * ASCONF_ACKs also must be sent to the source.
-			 */
-			if (chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT &&
-			    chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT_ACK &&
-			    chunk->chunk_hdr->type != SCTP_CID_ASCONF_ACK)
-				new_transport = asoc->peer.active_path;
-		}
-
-		/* Are we switching transports?
-		 * Take care of transport locks.
+		/* Pick the right transport to use. Should always be true for
+		 * the first chunk as we don't have a transport by then.
 		 */
-		if (new_transport != transport) {
-			transport = new_transport;
-			if (list_empty(&transport->send_ready)) {
-				list_add_tail(&transport->send_ready,
-					      &transport_list);
-			}
+		if (sctp_outq_select_transport(chunk, asoc, &transport,
+					       &transport_list))
 			packet = &transport->packet;
-			sctp_packet_config(packet, vtag,
-					   asoc->peer.ecn_capable);
-		}
 
 		switch (chunk->chunk_hdr->type) {
 		/*
@@ -1072,43 +1099,9 @@ static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
 				goto sctp_flush_out;
 			}
 
-			/* If there is a specified transport, use it.
-			 * Otherwise, we want to use the active path.
-			 */
-			new_transport = chunk->transport;
-			if (!new_transport ||
-			    ((new_transport->state == SCTP_INACTIVE) ||
-			     (new_transport->state == SCTP_UNCONFIRMED) ||
-			     (new_transport->state == SCTP_PF)))
-				new_transport = asoc->peer.active_path;
-			if (new_transport->state == SCTP_UNCONFIRMED) {
-				WARN_ONCE(1, "Attempt to send packet on unconfirmed path.");
-				sctp_sched_dequeue_done(q, chunk);
-				sctp_chunk_fail(chunk, 0);
-				sctp_chunk_free(chunk);
-				continue;
-			}
-
-			/* Change packets if necessary.  */
-			if (new_transport != transport) {
-				transport = new_transport;
-
-				/* Schedule to have this transport's
-				 * packet flushed.
-				 */
-				if (list_empty(&transport->send_ready)) {
-					list_add_tail(&transport->send_ready,
-						      &transport_list);
-				}
-
+			if (sctp_outq_select_transport(chunk, asoc, &transport,
+						       &transport_list))
 				packet = &transport->packet;
-				sctp_packet_config(packet, vtag,
-						   asoc->peer.ecn_capable);
-				/* We've switched transports, so apply the
-				 * Burst limit to the new transport.
-				 */
-				sctp_transport_burst_limited(transport);
-			}
 
 			pr_debug("%s: outq:%p, chunk:%p[%s], tx-tsn:0x%x skb->head:%p "
 				 "skb->users:%d\n",
-- 
2.14.3

^ permalink raw reply related

* [PATCH net-next v2 1/8] sctp: add sctp_packet_singleton
From: Marcelo Ricardo Leitner @ 2018-05-12 22:20 UTC (permalink / raw)
  To: netdev; +Cc: linux-sctp, Neil Horman, Vlad Yasevich, Xin Long
In-Reply-To: <cover.1526142784.git.marcelo.leitner@gmail.com>

Factor out the code for generating singletons. It's used only once, but
helps to keep the context contained.

The const variables are to ease the reading of subsequent calls in there.

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
---
 net/sctp/outqueue.c | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c
index dee7cbd5483149024f2f3195db2fe4d473b1a00a..300bd0dfc7c14c9df579dbe2f9e78dd8356ae1a3 100644
--- a/net/sctp/outqueue.c
+++ b/net/sctp/outqueue.c
@@ -776,6 +776,20 @@ void sctp_outq_uncork(struct sctp_outq *q, gfp_t gfp)
 	sctp_outq_flush(q, 0, gfp);
 }
 
+static int sctp_packet_singleton(struct sctp_transport *transport,
+				 struct sctp_chunk *chunk, gfp_t gfp)
+{
+	const struct sctp_association *asoc = transport->asoc;
+	const __u16 sport = asoc->base.bind_addr.port;
+	const __u16 dport = asoc->peer.port;
+	const __u32 vtag = asoc->peer.i.init_tag;
+	struct sctp_packet singleton;
+
+	sctp_packet_init(&singleton, transport, sport, dport);
+	sctp_packet_config(&singleton, vtag, 0);
+	sctp_packet_append_chunk(&singleton, chunk);
+	return sctp_packet_transmit(&singleton, gfp);
+}
 
 /*
  * Try to flush an outqueue.
@@ -789,10 +803,7 @@ void sctp_outq_uncork(struct sctp_outq *q, gfp_t gfp)
 static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
 {
 	struct sctp_packet *packet;
-	struct sctp_packet singleton;
 	struct sctp_association *asoc = q->asoc;
-	__u16 sport = asoc->base.bind_addr.port;
-	__u16 dport = asoc->peer.port;
 	__u32 vtag = asoc->peer.i.init_tag;
 	struct sctp_transport *transport = NULL;
 	struct sctp_transport *new_transport;
@@ -905,10 +916,7 @@ static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
 		case SCTP_CID_INIT:
 		case SCTP_CID_INIT_ACK:
 		case SCTP_CID_SHUTDOWN_COMPLETE:
-			sctp_packet_init(&singleton, transport, sport, dport);
-			sctp_packet_config(&singleton, vtag, 0);
-			sctp_packet_append_chunk(&singleton, chunk);
-			error = sctp_packet_transmit(&singleton, gfp);
+			error = sctp_packet_singleton(transport, chunk, gfp);
 			if (error < 0) {
 				asoc->base.sk->sk_err = -error;
 				return;
-- 
2.14.3

^ permalink raw reply related

* [PATCH net-next v2 0/8] sctp: refactor sctp_outq_flush
From: Marcelo Ricardo Leitner @ 2018-05-12 22:20 UTC (permalink / raw)
  To: netdev; +Cc: linux-sctp, Neil Horman, Vlad Yasevich, Xin Long

Currently sctp_outq_flush does many different things and arguably
unrelated, such as doing transport selection and outq dequeueing.

This patchset refactors it into smaller and more dedicated functions.
The end behavior should be the same.

The next patchset will rework the function parameters.

Changes since v1:
- fix build issues on patches 3 and 4, and updated 5 and 8 because of
  it.

Marcelo Ricardo Leitner (8):
  sctp: add sctp_packet_singleton
  sctp: factor out sctp_outq_select_transport
  sctp: move the flush of ctrl chunks into its own function
  sctp: move outq data rtx code out of sctp_outq_flush
  sctp: move flushing of data chunks out of sctp_outq_flush
  sctp: move transport flush code out of sctp_outq_flush
  sctp: make use of gfp on retransmissions
  sctp: rework switch cases in sctp_outq_flush_data

 net/sctp/outqueue.c | 593 +++++++++++++++++++++++++++-------------------------
 1 file changed, 311 insertions(+), 282 deletions(-)

^ permalink raw reply

* Re: [PATCH v6 1/6] net: phy: at803x: Export at803x_debug_reg_mask()
From: Andrew Lunn @ 2018-05-12 21:37 UTC (permalink / raw)
  To: Paul Burton; +Cc: Darren Hart, netdev, linux-mips, David S . Miller
In-Reply-To: <20180511222239.aznt4ngtnrbnvshf@pburton-laptop>

On Fri, May 11, 2018 at 03:22:39PM -0700, Paul Burton wrote:
> Hi Andrew,
> 
> On Fri, May 11, 2018 at 09:24:46PM +0200, Andrew Lunn wrote:
> > > I could reorder the probe function a little to initialize the PHY before
> > > performing the MAC reset, drop this patch and the AR803X hibernation
> > > stuff from patch 2 if you like. But again, I can't actually test the
> > > result on the affected hardware.
> > 
> > Hi Paul
> > 
> > I don't like a MAC driver poking around in PHY registers.
> > 
> > So if you can rearrange the code, that would be great.
> > 
> >    Thanks
> > 	Andrew
> 
> Sure, I'll give it a shot.
> 
> After digging into it I see 2 ways to go here:
> 
>   1) We could just always reset the PHY before we reset the MAC. That
>      would give us a window of however long the PHY takes to enter its
>      low power state & stop providing the RX clock during which we'd
>      need the MAC reset to complete. In the case of the AR8031 that's
>      "about 10 seconds" according to its data sheet. In this particular
>      case that feels like plenty, but it does also feel a bit icky to
>      rely on the timing chosen by the PHY manufacturer to line up with
>      that of the MAC reset.
> 
>   2) We could introduce a couple of new phy_* functions to disable &
>      enable low power states like the AR8031's hibernation feature, by
>      calling new function pointers in struct phy_driver. Then pch_gbe &
>      other MACs could call those to have the PHY driver disable
>      hibernation at times where we know we'll need the RX clock and
>      re-enable it afterwards.

Hi Paul

When there is no link, you don't need the MAC running. My assumption
is that the PHY is designed around that idea, you leave the MAC idle
until there is a link. When the phylib calls the link_change handler,
the MAC should then be started/stopped depending on the state of the
link. You are then guaranteed to have the clock when you need it.

I've no idea how easy this is to implement given the current code...

     Andrew

^ permalink raw reply

* Re: [PATCH bpf v3] x86/cpufeature: bpf hack for clang not supporting asm goto
From: Thomas Gleixner @ 2018-05-12 20:30 UTC (permalink / raw)
  To: Alexei Starovoitov
  Cc: Borislav Petkov, Peter Zijlstra, Yonghong Song, Ingo Molnar,
	Linus Torvalds, Alexei Starovoitov, Daniel Borkmann, LKML, X86 ML,
	Network Development, Kernel Team
In-Reply-To: <CAADnVQKVEmD4RrcTAiuMn-uua5TP0N-buvRHXq6Mgp1ZeF=G_Q@mail.gmail.com>

On Sat, 12 May 2018, Alexei Starovoitov wrote:
> On Thu, May 10, 2018 at 10:58 AM, Alexei Starovoitov
> <alexei.starovoitov@gmail.com> wrote:
> > I see no option, but to fix the kernel.
> > Regardless whether it's called user space breakage or kernel breakage.

There is a big difference. If you are abusing a kernel internal header in a
user space tool, then there is absolutely ZERO excuse for requesting that
the header in question has to be modified.

But yes, the situation is slightly different here because tools which
create trace event magic _HAVE_ to pull in kernel headers. At the same time
these tools depend on a compiler which failed to implement asm_goto for
fricking 8 years.

So while Boris is right, that nothing has to fiddle with a kernel only
header, I grumpily agree with you that we need a workaround in the kernel
for this particular issue.

> could you please ack the patch or better yet take it into tip tree
> and send to Linus asap ?

Nope. The patch is a horrible hack.

Why the heck do we need that extra fugly define? That has exactly zero
value simply because we already have a define which denotes availablity of
ASM GOTO: CC_HAVE_ASM_GOTO.

In case of samples/bpf/ and libbcc the compile does not go through the
arch/x86 Makefile which stops the build anyway when ASM_GOTO is
missing. Those builds merily pull in the headers and have their own build
magic, which is broken btw: Changing a kernel header which gets pulled into
the build does not rebuild anything in samples/bpf. Qualitee..

So we can just use CC_HAVE_ASM_GOTO and be done with it.

But we also want the tools which needs this to be aware of this. Peter
requested -D __BPF__ several times which got ignored. It's not too much of
a request to add that.

Find a patch which deos exactly this for samples/bpf, but also allows other
tools to build with a warning emitted so they get fixed.

Thanks,

	tglx

8<----------------
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -140,6 +140,20 @@ extern void clear_cpu_cap(struct cpuinfo
 
 #define setup_force_cpu_bug(bit) setup_force_cpu_cap(bit)
 
+#ifndef CC_HAVE_ASM_GOTO
+
+/*
+ * Workaround for the sake of BPF compilation which utilizes kernel
+ * headers, but clang does not support ASM GOTO and fails the build.
+ */
+#ifndef __BPF__
+#warning "Compiler lacks ASM_GOTO support. Add -D __BPF__ to your compiler arguments"
+#endif
+
+#define static_cpu_has(bit)		boot_cpu_has(bit)
+
+#else
+
 /*
  * Static testing of CPU features.  Used the same as boot_cpu_has().
  * These will statically patch the target code for additional
@@ -195,6 +209,7 @@ static __always_inline __pure bool _stat
 		boot_cpu_has(bit) :				\
 		_static_cpu_has(bit)				\
 )
+#endif
 
 #define cpu_has_bug(c, bit)		cpu_has(c, (bit))
 #define set_cpu_bug(c, bit)		set_cpu_cap(c, (bit))
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -255,7 +255,7 @@ verify_target_bpf: verify_cmds
 $(obj)/%.o: $(src)/%.c
 	$(CLANG) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS) -I$(obj) \
 		-I$(srctree)/tools/testing/selftests/bpf/ \
-		-D__KERNEL__ -Wno-unused-value -Wno-pointer-sign \
+		-D__KERNEL__ -D__BPF__ -Wno-unused-value -Wno-pointer-sign \
 		-D__TARGET_ARCH_$(ARCH) -Wno-compare-distinct-pointer-types \
 		-Wno-gnu-variable-sized-type-not-at-end \
 		-Wno-address-of-packed-member -Wno-tautological-compare \

^ permalink raw reply

* Re: KASAN: use-after-free Read in sit_tunnel_xmit
From: Eric Biggers @ 2018-05-12 20:06 UTC (permalink / raw)
  To: Cong Wang
  Cc: Dmitry Vyukov, syzbot, David Miller, Alexey Kuznetsov, LKML,
	Linux Kernel Network Developers, syzkaller-bugs,
	Hideaki YOSHIFUJI, Eric Dumazet, Willem de Bruijn
In-Reply-To: <CAM_iQpVEAZ3wOuKV_zbQ_j+1nzKyNHBb5Ne+OfGWDc7EKrPQrQ@mail.gmail.com>

On Thu, Feb 15, 2018 at 04:22:28PM -0800, Cong Wang wrote:
> On Tue, Feb 13, 2018 at 10:48 AM, Dmitry Vyukov <dvyukov@google.com> wrote:
> > On Mon, Oct 30, 2017 at 7:41 PM, Cong Wang <xiyou.wangcong@gmail.com> wrote:
> >> On Mon, Oct 30, 2017 at 8:34 AM, syzbot
> >> <bot+1aa412fe58f4059538c0204a0f096524e6dce60b@syzkaller.appspotmail.com>
> >> wrote:
> >>> Hello,
> >>>
> >>> syzkaller hit the following crash on
> >>> 4dc12ffeaeac939097a3f55c881d3dc3523dff0c
> >>> git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/master
> >>> compiler: gcc (GCC) 7.1.1 20170620
> >>> .config is attached
> >>> Raw console output is attached.
> >>>
> >>> skbuff: bad partial csum: csum=53081/14726 len=2273
> >>> ==================================================================
> >>> BUG: KASAN: use-after-free in ipv6_get_dsfield include/net/dsfield.h:23
> >>> [inline]
> >>> BUG: KASAN: use-after-free in ipip6_tunnel_xmit net/ipv6/sit.c:968 [inline]
> >>> BUG: KASAN: use-after-free in sit_tunnel_xmit+0x2a41/0x3130
> >>> net/ipv6/sit.c:1016
> >>> Read of size 2 at addr ffff8801c64afd00 by task syz-executor3/16942
> >>>
> >>> CPU: 0 PID: 16942 Comm: syz-executor3 Not tainted 4.14.0-rc5+ #97
> >>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> >>> Google 01/01/2011
> >>> Call Trace:
> >>>  __dump_stack lib/dump_stack.c:16 [inline]
> >>>  dump_stack+0x194/0x257 lib/dump_stack.c:52
> >>>  print_address_description+0x73/0x250 mm/kasan/report.c:252
> >>>  kasan_report_error mm/kasan/report.c:351 [inline]
> >>>  kasan_report+0x25b/0x340 mm/kasan/report.c:409
> >>>  __asan_report_load2_noabort+0x14/0x20 mm/kasan/report.c:428
> >>>  ipv6_get_dsfield include/net/dsfield.h:23 [inline]
> >>>  ipip6_tunnel_xmit net/ipv6/sit.c:968 [inline]
> >>>  sit_tunnel_xmit+0x2a41/0x3130 net/ipv6/sit.c:1016
> >>>  __netdev_start_xmit include/linux/netdevice.h:4022 [inline]
> >>>  netdev_start_xmit include/linux/netdevice.h:4031 [inline]
> >>>  xmit_one net/core/dev.c:3008 [inline]
> >>>  dev_hard_start_xmit+0x248/0xac0 net/core/dev.c:3024
> >>>  __dev_queue_xmit+0x17d2/0x2070 net/core/dev.c:3505
> >>>  dev_queue_xmit+0x17/0x20 net/core/dev.c:3538
> >>>  neigh_direct_output+0x15/0x20 net/core/neighbour.c:1390
> >>>  neigh_output include/net/neighbour.h:481 [inline]
> >>>  ip6_finish_output2+0xad1/0x22a0 net/ipv6/ip6_output.c:120
> >>>  ip6_fragment+0x25ae/0x3420 net/ipv6/ip6_output.c:723
> >>>  ip6_finish_output+0x319/0x920 net/ipv6/ip6_output.c:144
> >>>  NF_HOOK_COND include/linux/netfilter.h:238 [inline]
> >>>  ip6_output+0x1f4/0x850 net/ipv6/ip6_output.c:163
> >>>  dst_output include/net/dst.h:459 [inline]
> >>>  ip6_local_out+0x95/0x160 net/ipv6/output_core.c:176
> >>>  ip6_send_skb+0xa1/0x330 net/ipv6/ip6_output.c:1658
> >>>  ip6_push_pending_frames+0xb3/0xe0 net/ipv6/ip6_output.c:1678
> >>>  rawv6_push_pending_frames net/ipv6/raw.c:616 [inline]
> >>>  rawv6_sendmsg+0x2eb9/0x3e40 net/ipv6/raw.c:935
> >>>  inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:763
> >>>  sock_sendmsg_nosec net/socket.c:633 [inline]
> >>>  sock_sendmsg+0xca/0x110 net/socket.c:643
> >>>  SYSC_sendto+0x352/0x5a0 net/socket.c:1750
> >>>  SyS_sendto+0x40/0x50 net/socket.c:1718
> >>>  entry_SYSCALL_64_fastpath+0x1f/0xbe
> >>> RIP: 0033:0x452869
> >>> RSP: 002b:00007fe3c12e5be8 EFLAGS: 00000212 ORIG_RAX: 000000000000002c
> >>> RAX: ffffffffffffffda RBX: 00000000007580d8 RCX: 0000000000452869
> >>> RDX: 00000000000007f1 RSI: 000000002013b7ff RDI: 0000000000000014
> >>> RBP: 0000000000000161 R08: 00000000204e8fe4 R09: 000000000000001c
> >>> R10: 0000000001000000 R11: 0000000000000212 R12: 00000000006f01b8
> >>> R13: 00000000ffffffff R14: 00007fe3c12e66d4 R15: 0000000000000017
> >>>
> >>> Allocated by task 16924:
> >>>  save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
> >>>  save_stack+0x43/0xd0 mm/kasan/kasan.c:447
> >>>  set_track mm/kasan/kasan.c:459 [inline]
> >>>  kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
> >>>  __do_kmalloc_node mm/slab.c:3689 [inline]
> >>>  __kmalloc_node_track_caller+0x47/0x70 mm/slab.c:3703
> >>>  __kmalloc_reserve.isra.40+0x41/0xd0 net/core/skbuff.c:138
> >>>  __alloc_skb+0x13b/0x780 net/core/skbuff.c:206
> >>>  alloc_skb include/linux/skbuff.h:985 [inline]
> >>>  sock_wmalloc+0x140/0x1d0 net/core/sock.c:1932
> >>>  __ip6_append_data.isra.43+0x2681/0x3340 net/ipv6/ip6_output.c:1397
> >>>  ip6_append_data+0x189/0x290 net/ipv6/ip6_output.c:1552
> >>>  rawv6_sendmsg+0x1dd9/0x3e40 net/ipv6/raw.c:928
> >>>  inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:763
> >>>  sock_sendmsg_nosec net/socket.c:633 [inline]
> >>>  sock_sendmsg+0xca/0x110 net/socket.c:643
> >>>  SYSC_sendto+0x352/0x5a0 net/socket.c:1750
> >>>  SyS_sendto+0x40/0x50 net/socket.c:1718
> >>>  entry_SYSCALL_64_fastpath+0x1f/0xbe
> >>>
> >>> Freed by task 16942:
> >>>  save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
> >>>  save_stack+0x43/0xd0 mm/kasan/kasan.c:447
> >>>  set_track mm/kasan/kasan.c:459 [inline]
> >>>  kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
> >>>  __cache_free mm/slab.c:3503 [inline]
> >>>  kfree+0xca/0x250 mm/slab.c:3820
> >>>  skb_free_head+0x74/0xb0 net/core/skbuff.c:554
> >>>  pskb_expand_head+0x36b/0x1210 net/core/skbuff.c:1494
> >>>  __pskb_pull_tail+0x14a/0x17c0 net/core/skbuff.c:1877
> >>>  pskb_may_pull include/linux/skbuff.h:2102 [inline]
> >>>  _decode_session6+0x8a4/0x1100 net/ipv6/xfrm6_policy.c:148
> >>
> >> Looks like we should indicate error by returning some int
> >> for afinfo->decode_session().
> >
> >
> > Cong, do you want to do something with this bug? Otherwise I want to
> > close this as part of old bug bankruptcy.
> 
> I will work on a patch to address this.
> 
> Thanks.

Hi Cong, have you sent a patch for this yet?

Thanks,

Eric

^ permalink raw reply

* Re: KASAN: use-after-free Read in sctp_packet_transmit
From: Eric Biggers @ 2018-05-12 20:00 UTC (permalink / raw)
  To: syzbot
  Cc: davem, linux-kernel, linux-sctp, netdev, nhorman, syzkaller-bugs,
	vyasevich
In-Reply-To: <94eb2c1fcf4cf899b405620eaa66@google.com>

On Fri, Jan 05, 2018 at 02:07:01PM -0800, syzbot wrote:
> Hello,
> 
> syzkaller hit the following crash on
> 8a4816cad00bf14642f0ed6043b32d29a05006ce
> git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/master
> compiler: gcc (GCC) 7.1.1 20170620
> .config is attached
> Raw console output is attached.
> Unfortunately, I don't have any reproducer for this bug yet.
> 
> 
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+5adcca18fca253b4cb15@syzkaller.appspotmail.com
> It will help syzbot understand when the bug is fixed. See footer for
> details.
> If you forward the report, please keep this part and the footer.
> 
> ==================================================================
> BUG: KASAN: use-after-free in sctp_packet_transmit+0x3505/0x3750
> net/sctp/output.c:643
> Read of size 8 at addr ffff8801bda9fb80 by task modprobe/23740
> 
> CPU: 1 PID: 23740 Comm: modprobe Not tainted 4.15.0-rc5+ #175
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> Google 01/01/2011
> Call Trace:
>  <IRQ>
>  __dump_stack lib/dump_stack.c:17 [inline]
>  dump_stack+0x194/0x257 lib/dump_stack.c:53
>  print_address_description+0x73/0x250 mm/kasan/report.c:252
>  kasan_report_error mm/kasan/report.c:351 [inline]
>  kasan_report+0x25b/0x340 mm/kasan/report.c:409
>  __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430
>  sctp_packet_transmit+0x3505/0x3750 net/sctp/output.c:643
>  sctp_outq_flush+0x121b/0x4060 net/sctp/outqueue.c:1197
>  sctp_outq_uncork+0x5a/0x70 net/sctp/outqueue.c:776
>  sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1807 [inline]
>  sctp_side_effects net/sctp/sm_sideeffect.c:1210 [inline]
>  sctp_do_sm+0x4e0/0x6ed0 net/sctp/sm_sideeffect.c:1181
>  sctp_generate_heartbeat_event+0x292/0x3f0 net/sctp/sm_sideeffect.c:406
>  call_timer_fn+0x228/0x820 kernel/time/timer.c:1320
>  expire_timers kernel/time/timer.c:1357 [inline]
>  __run_timers+0x7ee/0xb70 kernel/time/timer.c:1660
>  run_timer_softirq+0x4c/0xb0 kernel/time/timer.c:1686
>  __do_softirq+0x2d7/0xb85 kernel/softirq.c:285
>  invoke_softirq kernel/softirq.c:365 [inline]
>  irq_exit+0x1cc/0x200 kernel/softirq.c:405
>  exiting_irq arch/x86/include/asm/apic.h:540 [inline]
>  smp_apic_timer_interrupt+0x16b/0x700 arch/x86/kernel/apic/apic.c:1052
>  apic_timer_interrupt+0xa9/0xb0 arch/x86/entry/entry_64.S:904
>  </IRQ>
> RIP: 0010:__preempt_count_add arch/x86/include/asm/preempt.h:76 [inline]
> RIP: 0010:__rcu_read_lock include/linux/rcupdate.h:83 [inline]
> RIP: 0010:rcu_read_lock include/linux/rcupdate.h:629 [inline]
> RIP: 0010:__is_insn_slot_addr+0x8f/0x330 kernel/kprobes.c:303
> RSP: 0018:ffff8801d4937430 EFLAGS: 00000283 ORIG_RAX: ffffffffffffff11
> RAX: ffff8801bf13c000 RBX: ffffffff8656dd00 RCX: ffffffff8170bd88
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8656dd00
> RBP: ffff8801d4937518 R08: 0000000000000000 R09: 1ffff1003a926e67
> R10: ffff8801d4937300 R11: 0000000000000000 R12: 0000000000000000
> R13: 0000000000000000 R14: ffff8801d49374f0 R15: ffff8801dae230c0
>  is_kprobe_insn_slot include/linux/kprobes.h:318 [inline]
>  kernel_text_address+0x132/0x140 kernel/extable.c:150
>  __kernel_text_address+0xd/0x40 kernel/extable.c:107
>  unwind_get_return_address+0x61/0xa0 arch/x86/kernel/unwind_frame.c:18
>  __save_stack_trace+0x7e/0xd0 arch/x86/kernel/stacktrace.c:45
>  save_stack_trace+0x1a/0x20 arch/x86/kernel/stacktrace.c:60
>  save_stack+0x43/0xd0 mm/kasan/kasan.c:447
>  set_track mm/kasan/kasan.c:459 [inline]
>  kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
>  kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489
>  kmem_cache_alloc+0x12e/0x760 mm/slab.c:3544
>  kmem_cache_zalloc include/linux/slab.h:678 [inline]
>  file_alloc_security security/selinux/hooks.c:369 [inline]
>  selinux_file_alloc_security+0xae/0x190 security/selinux/hooks.c:3454
>  security_file_alloc+0x6d/0xa0 security/security.c:873
>  get_empty_filp+0x189/0x4f0 fs/file_table.c:129
>  path_openat+0xed/0x3530 fs/namei.c:3496
>  do_filp_open+0x25b/0x3b0 fs/namei.c:3554
>  do_sys_open+0x502/0x6d0 fs/open.c:1059
>  SYSC_open fs/open.c:1077 [inline]
>  SyS_open+0x2d/0x40 fs/open.c:1072
>  entry_SYSCALL_64_fastpath+0x23/0x9a
> RIP: 0033:0x7efdff1bb120
> RSP: 002b:00007ffde6213c08 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
> RAX: ffffffffffffffda RBX: 000055c34fab4090 RCX: 00007efdff1bb120
> RDX: 00000000000001b6 RSI: 0000000000080000 RDI: 00007ffde6213d20
> RBP: 00007ffde6214d90 R08: 0000000000000008 R09: 0000000000000001
> R10: 0000000000000000 R11: 0000000000000246 R12: 000055c34fab4090
> R13: 00007ffde6215de0 R14: 0000000000000000 R15: 0000000000000000
> 
> Allocated by task 23739:
>  save_stack+0x43/0xd0 mm/kasan/kasan.c:447
>  set_track mm/kasan/kasan.c:459 [inline]
>  kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
>  kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489
>  kmem_cache_alloc+0x12e/0x760 mm/slab.c:3544
>  kmem_cache_zalloc include/linux/slab.h:678 [inline]
>  sctp_chunkify+0xce/0x3f0 net/sctp/sm_make_chunk.c:1329
>  _sctp_make_chunk+0x13c/0x260 net/sctp/sm_make_chunk.c:1397
>  sctp_make_control+0x39/0x150 net/sctp/sm_make_chunk.c:1433
>  sctp_make_heartbeat+0x90/0x420 net/sctp/sm_make_chunk.c:1151
>  sctp_sf_heartbeat.isra.24+0x26/0x180 net/sctp/sm_statefuns.c:973
>  sctp_sf_do_prm_requestheartbeat+0x27/0x100 net/sctp/sm_statefuns.c:5251
>  sctp_do_sm+0x192/0x6ed0 net/sctp/sm_sideeffect.c:1178
>  sctp_primitive_REQUESTHEARTBEAT+0xa0/0xd0 net/sctp/primitive.c:200
>  sctp_apply_peer_addr_params+0x759/0xf30 net/sctp/socket.c:2462
>  sctp_setsockopt_peer_addr_params+0x36f/0x5f0 net/sctp/socket.c:2658
>  sctp_setsockopt+0x199a/0x61a0 net/sctp/socket.c:4173
>  sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2978
>  SYSC_setsockopt net/socket.c:1821 [inline]
>  SyS_setsockopt+0x189/0x360 net/socket.c:1800
>  entry_SYSCALL_64_fastpath+0x23/0x9a
> 
> Freed by task 23739:
>  save_stack+0x43/0xd0 mm/kasan/kasan.c:447
>  set_track mm/kasan/kasan.c:459 [inline]
>  kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
>  __cache_free mm/slab.c:3488 [inline]
>  kmem_cache_free+0x83/0x2a0 mm/slab.c:3746
>  sctp_chunk_destroy net/sctp/sm_make_chunk.c:1450 [inline]
>  sctp_chunk_put+0x2fd/0x420 net/sctp/sm_make_chunk.c:1473
>  sctp_chunk_free+0x53/0x60 net/sctp/sm_make_chunk.c:1460
>  sctp_packet_transmit+0xf5d/0x3750 net/sctp/output.c:646
>  sctp_outq_flush+0x121b/0x4060 net/sctp/outqueue.c:1197
>  sctp_outq_uncork+0x5a/0x70 net/sctp/outqueue.c:776
>  sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1807 [inline]
>  sctp_side_effects net/sctp/sm_sideeffect.c:1210 [inline]
>  sctp_do_sm+0x4e0/0x6ed0 net/sctp/sm_sideeffect.c:1181
>  sctp_primitive_REQUESTHEARTBEAT+0xa0/0xd0 net/sctp/primitive.c:200
>  sctp_apply_peer_addr_params+0x759/0xf30 net/sctp/socket.c:2462
>  sctp_setsockopt_peer_addr_params+0x36f/0x5f0 net/sctp/socket.c:2658
>  sctp_setsockopt+0x199a/0x61a0 net/sctp/socket.c:4173
>  sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2978
>  SYSC_setsockopt net/socket.c:1821 [inline]
>  SyS_setsockopt+0x189/0x360 net/socket.c:1800
>  entry_SYSCALL_64_fastpath+0x23/0x9a
> 
> The buggy address belongs to the object at ffff8801bda9fb80
>  which belongs to the cache sctp_chunk of size 256
> The buggy address is located 0 bytes inside of
>  256-byte region [ffff8801bda9fb80, ffff8801bda9fc80)
> The buggy address belongs to the page:
> page:00000000d1261812 count:1 mapcount:0 mapping:000000003e733284 index:0x0
> flags: 0x2fffc0000000100(slab)
> raw: 02fffc0000000100 ffff8801bda9f040 0000000000000000 000000010000000c
> raw: ffffea000714c9e0 ffffea0006fa8520 ffff8801d3246c80 0000000000000000
> page dumped because: kasan: bad access detected
> 
> Memory state around the buggy address:
>  ffff8801bda9fa80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>  ffff8801bda9fb00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
> > ffff8801bda9fb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>                    ^
>  ffff8801bda9fc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>  ffff8801bda9fc80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
> ==================================================================
> 
> 
> ---
> This bug is generated by a dumb bot. It may contain errors.
> See https://goo.gl/tpsmEJ for details.
> Direct all questions to syzkaller@googlegroups.com.
> 
> syzbot will keep track of this bug report.
> If you forgot to add the Reported-by tag, once the fix for this bug is
> merged
> into any tree, please reply to this email with:
> #syz fix: exact-commit-title
> To mark this as a duplicate of another syzbot report, please reply with:
> #syz dup: exact-subject-of-another-report
> If it's a one-off invalid bug report, please reply with:
> #syz invalid
> Note: if the crash happens again, it will cause creation of a new bug
> report.
> Note: all commands must start from beginning of the line in the email body.

No reproducer, this only happened once (Jan 5 on net-next), and there have been
a lot of SCTP fixes in the mean time including commit 6910e25de225 ("sctp:
remove sctp_chunk_put from fail_mark err path in sctp_ulpevent_make_rcvmsg")
which may be relevant since it fixed a case of incorrect reference counting of
'struct sctp_chunk', which is the struct in which the use-after-free occurred
here.  So I'm just invalidating this bug:

#syz invalid

- Eric

^ permalink raw reply

* Re: [PATCH bpf-next 3/4] samples: bpf: fix build after move to compiling full libbpf.a
From: Jakub Kicinski @ 2018-05-12 19:38 UTC (permalink / raw)
  To: alexei.starovoitov, daniel; +Cc: oss-drivers, netdev, Björn Töpel
In-Reply-To: <20180512001729.21634-4-jakub.kicinski@netronome.com>

On Fri, 11 May 2018 17:17:28 -0700, Jakub Kicinski wrote:
> There are many ways users may compile samples, some of them got
> broken by commit 5f9380572b4b ("samples: bpf: compile and link
> against full libbpf").  Improve path resolution and make libbpf
> building a dependency of source files to force its build.
> 
> Samples should now again build with any of:
>  cd samples/bpf; make
>  make samples/bpf
>  make -C samples/bpf
>  cd samples/bpf; make O=builddir
>  make samples/bpf O=builddir
>  make -C samples/bpf O=builddir
> 
> Fixes: 5f9380572b4b ("samples: bpf: compile and link against full libbpf")
> Reported-by: Björn Töpel <bjorn.topel@gmail.com>
> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>

Unfortunately Björn reports this still doesn't fix the build for him.
Investigating further.

^ permalink raw reply

* [PATCH] net/mlx5: Use 'kvfree()' for memory allocated by 'kvzalloc()'
From: Christophe JAILLET @ 2018-05-12 17:09 UTC (permalink / raw)
  To: saeedm, matanb, leon, davem
  Cc: netdev, linux-rdma, linux-kernel, kernel-janitors,
	Christophe JAILLET

'out' is allocated with 'kvzalloc()'. 'kvfree()' must be used to free it.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
 drivers/net/ethernet/mellanox/mlx5/core/vport.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/vport.c b/drivers/net/ethernet/mellanox/mlx5/core/vport.c
index 177e076b8d17..49968a4db758 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/vport.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/vport.c
@@ -511,7 +511,7 @@ int mlx5_query_nic_vport_system_image_guid(struct mlx5_core_dev *mdev,
 	*system_image_guid = MLX5_GET64(query_nic_vport_context_out, out,
 					nic_vport_context.system_image_guid);
 
-	kfree(out);
+	kvfree(out);
 
 	return 0;
 }
-- 
2.17.0

^ permalink raw reply related

* Re: iproute2 - modifying routes in place
From: David Ahern @ 2018-05-12 17:00 UTC (permalink / raw)
  To: Ryan Whelan, netdev
In-Reply-To: <CAM3m09SxxFRfhssnj9k21D=PVfJ-yRx7P2DnfpLK2C4QHvcrtQ@mail.gmail.com>

On 5/11/18 4:42 AM, Ryan Whelan wrote:
> `ip route` has 2 subcommands that don't seem to work as expected and i'm
> not sure if its a bug, or if i'm misunderstanding the semantics.

Can you try with ipv6/route-bugs branch in
https://github.com/dsahern/linux

^ permalink raw reply

* Re: [PATCH bpf v3] x86/cpufeature: bpf hack for clang not supporting asm goto
From: Alexei Starovoitov @ 2018-05-12 16:03 UTC (permalink / raw)
  To: Borislav Petkov
  Cc: Peter Zijlstra, Yonghong Song, Ingo Molnar, Linus Torvalds,
	Alexei Starovoitov, Daniel Borkmann, LKML, X86 ML,
	Network Development, Kernel Team, Thomas Gleixner

On Thu, May 10, 2018 at 10:58 AM, Alexei Starovoitov
<alexei.starovoitov@gmail.com> wrote:
> I see no option, but to fix the kernel.
> Regardless whether it's called user space breakage or kernel breakage.

Peter,

could you please ack the patch or better yet take it into tip tree
and send to Linus asap ?
rc5 is almost here and we didn't have full test coverage
for more than a month due to this issue.

Thanks

^ permalink raw reply

* Re: [PATCH bpf-next v5 0/6] ipv6: sr: introduce seg6local End.BPF action
From: Mathieu Xhonneux @ 2018-05-12 15:30 UTC (permalink / raw)
  To: Alexei Starovoitov; +Cc: netdev
In-Reply-To: <cover.1526143526.git.m.xhonneux@gmail.com>

Sorry for the v4 still throwing warnings from the kbuild bot, this
version should be OK.

2018-05-12 18:25 GMT+01:00 Mathieu Xhonneux <m.xhonneux@gmail.com>:
> As of Linux 4.14, it is possible to define advanced local processing for
> IPv6 packets with a Segment Routing Header through the seg6local LWT
> infrastructure. This LWT implements the network programming principles
> defined in the IETF “SRv6 Network Programming” draft.
>
> The implemented operations are generic, and it would be very interesting to
> be able to implement user-specific seg6local actions, without having to
> modify the kernel directly. To do so, this patchset adds an End.BPF action
> to seg6local, powered by some specific Segment Routing-related helpers,
> which provide SR functionalities that can be applied on the packet. This
> BPF hook would then allow to implement specific actions at native kernel
> speed such as OAM features, advanced SR SDN policies, SRv6 actions like
> Segment Routing Header (SRH) encapsulation depending on the content of
> the packet, etc.
>
> This patchset is divided in 6 patches, whose main features are :
>
> - A new seg6local action End.BPF with the corresponding new BPF program
>   type BPF_PROG_TYPE_LWT_SEG6LOCAL. Such attached BPF program can be
>   passed to the LWT seg6local through netlink, the same way as the LWT
>   BPF hook operates.
> - 3 new BPF helpers for the seg6local BPF hook, allowing to edit/grow/
>   shrink a SRH and apply on a packet some of the generic SRv6 actions.
> - 1 new BPF helper for the LWT BPF IN hook, allowing to add a SRH through
>   encapsulation (via IPv6 encapsulation or inlining if the packet contains
>   already an IPv6 header).
>
> As this patchset adds a new LWT BPF hook, I took into account the result of
> the discussions when the LWT BPF infrastructure got merged. Hence, the
> seg6local BPF hook doesn’t allow write access to skb->data directly, only
> the SRH can be modified through specific helpers, which ensures that the
> integrity of the packet is maintained.
> More details are available in the related patches messages.
>
> The performances of this BPF hook have been assessed with the BPF JIT
> enabled on a Intel Xeon X3440 processors with 4 cores and 8 threads
> clocked at 2.53 GHz. No throughput losses are noted with the seg6local
> BPF hook when the BPF program does nothing (440kpps). Adding a 8-bytes
> TLV (1 call each to bpf_lwt_seg6_adjust_srh and bpf_lwt_seg6_store_bytes)
> drops the throughput to 410kpps, and inlining a SRH via
> bpf_lwt_seg6_action drops the throughput to 420kpps.
> All throughputs are stable.
>
> -------
> v2: move the SRH integrity state from skb->cb to a per-cpu buffer
> v3: - document helpers in man-page style
>     - fix kbuild bugs
>     - un-break BPF LWT out hook
>     - bpf_push_seg6_encap is now static
>     - preempt_enable is now called when the packet is dropped in
>       input_action_end_bpf
> v4: fix kbuild bugs when CONFIG_IPV6=m
> v5: fix kbuild sparse warnings when CONFIG_IPV6=m
>
> Thanks.
>
>
> Mathieu Xhonneux (6):
>   ipv6: sr: make seg6.h includable without IPv6
>   ipv6: sr: export function lookup_nexthop
>   bpf: Add IPv6 Segment Routing helpers
>   bpf: Split lwt inout verifier structures
>   ipv6: sr: Add seg6local action End.BPF
>   selftests/bpf: test for seg6local End.BPF action
>
>  include/linux/bpf_types.h                         |   5 +-
>  include/net/seg6.h                                |   7 +-
>  include/net/seg6_local.h                          |  32 ++
>  include/uapi/linux/bpf.h                          |  98 ++++-
>  include/uapi/linux/seg6_local.h                   |   3 +
>  kernel/bpf/verifier.c                             |   1 +
>  net/core/filter.c                                 | 390 ++++++++++++++++---
>  net/ipv6/Kconfig                                  |   5 +
>  net/ipv6/seg6_local.c                             | 180 ++++++++-
>  tools/include/uapi/linux/bpf.h                    |  98 ++++-
>  tools/lib/bpf/libbpf.c                            |   1 +
>  tools/testing/selftests/bpf/Makefile              |   5 +-
>  tools/testing/selftests/bpf/bpf_helpers.h         |  12 +
>  tools/testing/selftests/bpf/test_lwt_seg6local.c  | 438 ++++++++++++++++++++++
>  tools/testing/selftests/bpf/test_lwt_seg6local.sh | 140 +++++++
>  15 files changed, 1340 insertions(+), 75 deletions(-)
>  create mode 100644 include/net/seg6_local.h
>  create mode 100644 tools/testing/selftests/bpf/test_lwt_seg6local.c
>  create mode 100755 tools/testing/selftests/bpf/test_lwt_seg6local.sh
>
> --
> 2.16.1
>

^ permalink raw reply

* [PATCH bpf-next v5 6/6] selftests/bpf: test for seg6local End.BPF action
From: Mathieu Xhonneux @ 2018-05-12 17:25 UTC (permalink / raw)
  To: netdev; +Cc: dlebrun, alexei.starovoitov
In-Reply-To: <cover.1526143526.git.m.xhonneux@gmail.com>

Add a new test for the seg6local End.BPF action. The following helpers
are also tested :

- bpf_lwt_push_encap within the LWT BPF IN hook
- bpf_lwt_seg6_action
- bpf_lwt_seg6_adjust_srh
- bpf_lwt_seg6_store_bytes

A chain of End.BPF actions is built. The SRH is injected through a LWT
BPF IN hook before the chain. Each End.BPF action validates the previous
one, otherwise the packet is dropped.
The test succeeds if the last node in the chain receives the packet and
the UDP datagram contained can be retrieved from userspace.

Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com>
---
 tools/include/uapi/linux/bpf.h                    |  98 ++++-
 tools/testing/selftests/bpf/Makefile              |   5 +-
 tools/testing/selftests/bpf/bpf_helpers.h         |  12 +
 tools/testing/selftests/bpf/test_lwt_seg6local.c  | 438 ++++++++++++++++++++++
 tools/testing/selftests/bpf/test_lwt_seg6local.sh | 140 +++++++
 5 files changed, 689 insertions(+), 4 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/test_lwt_seg6local.c
 create mode 100755 tools/testing/selftests/bpf/test_lwt_seg6local.sh

diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 02e4112510f8..c6a213075368 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -140,6 +140,7 @@ enum bpf_prog_type {
 	BPF_PROG_TYPE_SK_MSG,
 	BPF_PROG_TYPE_RAW_TRACEPOINT,
 	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
+	BPF_PROG_TYPE_LWT_SEG6LOCAL,
 };
 
 enum bpf_attach_type {
@@ -1828,7 +1829,6 @@ union bpf_attr {
  * 	Return
  * 		0 on success, or a negative error in case of failure.
  *
- *
  * int bpf_fib_lookup(void *ctx, struct bpf_fib_lookup *params, int plen, u32 flags)
  *	Description
  *		Do FIB lookup in kernel tables using parameters in *params*.
@@ -1855,6 +1855,90 @@ union bpf_attr {
  *             Egress device index on success, 0 if packet needs to continue
  *             up the stack for further processing or a negative error in case
  *             of failure.
+ *
+ * int bpf_lwt_push_encap(struct sk_buff *skb, u32 type, void *hdr, u32 len)
+ *	Description
+ *		Encapsulate the packet associated to *skb* within a Layer 3
+ *		protocol header. This header is provided in the buffer at
+ *		address *hdr*, with *len* its size in bytes. *type* indicates
+ *		the protocol of the header and can be one of:
+ *
+ *		**BPF_LWT_ENCAP_SEG6**
+ *			IPv6 encapsulation with Segment Routing Header
+ *			(**struct ipv6_sr_hdr**). *hdr* only contains the SRH,
+ *			the IPv6 header is computed by the kernel.
+ *		**BPF_LWT_ENCAP_SEG6_INLINE**
+ *			Only works if *skb* contains an IPv6 packet. Insert a
+ *			Segment Routing Header (**struct ipv6_sr_hdr**) inside
+ *			the IPv6 header.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ *	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_lwt_seg6_store_bytes(struct sk_buff *skb, u32 offset, const void *from, u32 len)
+ *	Description
+ *		Store *len* bytes from address *from* into the packet
+ *		associated to *skb*, at *offset*. Only the flags, tag and TLVs
+ *		inside the outermost IPv6 Segment Routing Header can be
+ *		modified through this helper.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ *	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_lwt_seg6_adjust_srh(struct sk_buff *skb, u32 offset, s32 delta)
+ *	Description
+ *		Adjust the size allocated to TLVs in the outermost IPv6
+ *		Segment Routing Header contained in the packet associated to
+ *		*skb*, at position *offset* by *delta* bytes. Only offsets
+ *		after the segments are accepted. *delta* can be as well
+ *		positive (growing) as negative (shrinking).
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ *	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_lwt_seg6_action(struct sk_buff *skb, u32 action, void *param, u32 param_len)
+ *	Description
+ *		Apply an IPv6 Segment Routing action of type *action* to the
+ *		packet associated to *skb*. Each action takes a parameter
+ *		contained at address *param*, and of length *param_len* bytes.
+ *		*action* can be one of:
+ *
+ *		**SEG6_LOCAL_ACTION_END_X**
+ *			End.X action: Endpoint with Layer-3 cross-connect.
+ *			Type of *param*: **struct in6_addr**.
+ *		**SEG6_LOCAL_ACTION_END_T**
+ *			End.T action: Endpoint with specific IPv6 table lookup.
+ *			Type of *param*: **int**.
+ *		**SEG6_LOCAL_ACTION_END_B6**
+ *			End.B6 action: Endpoint bound to an SRv6 policy.
+ *			Type of param: **struct ipv6_sr_hdr**.
+ *		**SEG6_LOCAL_ACTION_END_B6_ENCAP**
+ *			End.B6.Encap action: Endpoint bound to an SRv6
+ *			encapsulation policy.
+ *			Type of param: **struct ipv6_sr_hdr**.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ *	Return
+ * 		0 on success, or a negative error in case of failure.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -1926,7 +2010,11 @@ union bpf_attr {
 	FN(skb_get_xfrm_state),		\
 	FN(get_stack),			\
 	FN(skb_load_bytes_relative),	\
-	FN(fib_lookup),
+	FN(fib_lookup),			\
+	FN(lwt_push_encap),		\
+	FN(lwt_seg6_store_bytes),	\
+	FN(lwt_seg6_adjust_srh),	\
+	FN(lwt_seg6_action),
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call
@@ -1993,6 +2081,12 @@ enum bpf_hdr_start_off {
 	BPF_HDR_START_NET,
 };
 
+/* Encapsulation type for BPF_FUNC_lwt_push_encap helper. */
+enum bpf_lwt_encap_mode {
+	BPF_LWT_ENCAP_SEG6,
+	BPF_LWT_ENCAP_SEG6_INLINE
+};
+
 /* user accessible mirror of in-kernel sk_buff.
  * new fields can only be added to the end of this structure
  */
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 438d4f93875b..009aa27be884 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -33,7 +33,7 @@ TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o test
 	sample_map_ret0.o test_tcpbpf_kern.o test_stacktrace_build_id.o \
 	sockmap_tcp_msg_prog.o connect4_prog.o connect6_prog.o test_adjust_tail.o \
 	test_btf_haskv.o test_btf_nokv.o test_sockmap_kern.o test_tunnel_kern.o \
-	test_get_stack_rawtp.o
+	test_get_stack_rawtp.o test_lwt_seg6local.o
 
 # Order correspond to 'make run_tests' order
 TEST_PROGS := test_kmod.sh \
@@ -42,7 +42,8 @@ TEST_PROGS := test_kmod.sh \
 	test_xdp_meta.sh \
 	test_offload.py \
 	test_sock_addr.sh \
-	test_tunnel.sh
+	test_tunnel.sh \
+	test_lwt_seg6local.sh
 
 # Compile but not part of 'make run_tests'
 TEST_GEN_PROGS_EXTENDED = test_libbpf_open test_sock_addr
diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h
index 2375d06c706b..b29f2215361b 100644
--- a/tools/testing/selftests/bpf/bpf_helpers.h
+++ b/tools/testing/selftests/bpf/bpf_helpers.h
@@ -106,6 +106,18 @@ static int (*bpf_get_stack)(void *ctx, void *buf, int size, int flags) =
 static int (*bpf_fib_lookup)(void *ctx, struct bpf_fib_lookup *params,
 			     int plen, __u32 flags) =
 	(void *) BPF_FUNC_fib_lookup;
+static int (*bpf_lwt_push_encap)(void *ctx, unsigned int type, void *hdr,
+				 unsigned int len) =
+	(void *) BPF_FUNC_lwt_push_encap;
+static int (*bpf_lwt_seg6_store_bytes)(void *ctx, unsigned int offset,
+				       void *from, unsigned int len) =
+	(void *) BPF_FUNC_lwt_seg6_store_bytes;
+static int (*bpf_lwt_seg6_action)(void *ctx, unsigned int action, void *param,
+				  unsigned int param_len) =
+	(void *) BPF_FUNC_lwt_seg6_action;
+static int (*bpf_lwt_seg6_adjust_srh)(void *ctx, unsigned int offset,
+				      unsigned int len) =
+	(void *) BPF_FUNC_lwt_seg6_adjust_srh;
 
 /* llvm builtin functions that eBPF C program may use to
  * emit BPF_LD_ABS and BPF_LD_IND instructions
diff --git a/tools/testing/selftests/bpf/test_lwt_seg6local.c b/tools/testing/selftests/bpf/test_lwt_seg6local.c
new file mode 100644
index 000000000000..d752bc1fe81c
--- /dev/null
+++ b/tools/testing/selftests/bpf/test_lwt_seg6local.c
@@ -0,0 +1,438 @@
+#include <stddef.h>
+#include <inttypes.h>
+#include <errno.h>
+#include <linux/seg6_local.h>
+#include <linux/bpf.h>
+#include "bpf_helpers.h"
+#include "bpf_endian.h"
+
+#define bpf_printk(fmt, ...)				\
+({							\
+	char ____fmt[] = fmt;				\
+	bpf_trace_printk(____fmt, sizeof(____fmt),	\
+			##__VA_ARGS__);			\
+})
+
+/* Packet parsing state machine helpers. */
+#define cursor_advance(_cursor, _len) \
+	({ void *_tmp = _cursor; _cursor += _len; _tmp; })
+
+#define SR6_FLAG_ALERT (1 << 4)
+
+#define htonll(x) ((bpf_htonl(1)) == 1 ? (x) : ((uint64_t)bpf_htonl((x) & \
+				0xFFFFFFFF) << 32) | bpf_htonl((x) >> 32))
+#define ntohll(x) ((bpf_ntohl(1)) == 1 ? (x) : ((uint64_t)bpf_ntohl((x) & \
+				0xFFFFFFFF) << 32) | bpf_ntohl((x) >> 32))
+#define BPF_PACKET_HEADER __attribute__((packed))
+
+struct ip6_t {
+	unsigned int ver:4;
+	unsigned int priority:8;
+	unsigned int flow_label:20;
+	unsigned short payload_len;
+	unsigned char next_header;
+	unsigned char hop_limit;
+	unsigned long long src_hi;
+	unsigned long long src_lo;
+	unsigned long long dst_hi;
+	unsigned long long dst_lo;
+} BPF_PACKET_HEADER;
+
+struct ip6_addr_t {
+	unsigned long long hi;
+	unsigned long long lo;
+} BPF_PACKET_HEADER;
+
+struct ip6_srh_t {
+	unsigned char nexthdr;
+	unsigned char hdrlen;
+	unsigned char type;
+	unsigned char segments_left;
+	unsigned char first_segment;
+	unsigned char flags;
+	unsigned short tag;
+
+	struct ip6_addr_t segments[0];
+} BPF_PACKET_HEADER;
+
+struct sr6_tlv_t {
+	unsigned char type;
+	unsigned char len;
+	unsigned char value[0];
+} BPF_PACKET_HEADER;
+
+__attribute__((always_inline)) struct ip6_srh_t *get_srh(struct __sk_buff *skb)
+{
+	void *cursor, *data_end;
+	struct ip6_srh_t *srh;
+	struct ip6_t *ip;
+	uint8_t *ipver;
+
+	data_end = (void *)(long)skb->data_end;
+	cursor = (void *)(long)skb->data;
+	ipver = (uint8_t *)cursor;
+
+	if ((void *)ipver + sizeof(*ipver) > data_end)
+		return NULL;
+
+	if ((*ipver >> 4) != 6)
+		return NULL;
+
+	ip = cursor_advance(cursor, sizeof(*ip));
+	if ((void *)ip + sizeof(*ip) > data_end)
+		return NULL;
+
+	if (ip->next_header != 43)
+		return NULL;
+
+	srh = cursor_advance(cursor, sizeof(*srh));
+	if ((void *)srh + sizeof(*srh) > data_end)
+		return NULL;
+
+	if (srh->type != 4)
+		return NULL;
+
+	return srh;
+}
+
+__attribute__((always_inline))
+int update_tlv_pad(struct __sk_buff *skb, uint32_t new_pad,
+		   uint32_t old_pad, uint32_t pad_off)
+{
+	int err;
+
+	if (new_pad != old_pad) {
+		err = bpf_lwt_seg6_adjust_srh(skb, pad_off,
+					  (int) new_pad - (int) old_pad);
+		if (err)
+			return err;
+	}
+
+	if (new_pad > 0) {
+		char pad_tlv_buf[16] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+					0, 0, 0};
+		struct sr6_tlv_t *pad_tlv = (struct sr6_tlv_t *) pad_tlv_buf;
+
+		pad_tlv->type = SR6_TLV_PADDING;
+		pad_tlv->len = new_pad - 2;
+
+		err = bpf_lwt_seg6_store_bytes(skb, pad_off,
+					       (void *)pad_tlv_buf, new_pad);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+__attribute__((always_inline))
+int is_valid_tlv_boundary(struct __sk_buff *skb, struct ip6_srh_t *srh,
+			  uint32_t *tlv_off, uint32_t *pad_size,
+			  uint32_t *pad_off)
+{
+	uint32_t srh_off, cur_off;
+	int offset_valid = 0;
+	int err;
+
+	srh_off = (char *)srh - (char *)(long)skb->data;
+	// cur_off = end of segments, start of possible TLVs
+	cur_off = srh_off + sizeof(*srh) +
+		sizeof(struct ip6_addr_t) * (srh->first_segment + 1);
+
+	*pad_off = 0;
+
+	// we can only go as far as ~10 TLVs due to the BPF max stack size
+	#pragma clang loop unroll(full)
+	for (int i = 0; i < 10; i++) {
+		struct sr6_tlv_t tlv;
+
+		if (cur_off == *tlv_off)
+			offset_valid = 1;
+
+		if (cur_off >= srh_off + ((srh->hdrlen + 1) << 3))
+			break;
+
+		err = bpf_skb_load_bytes(skb, cur_off, &tlv, sizeof(tlv));
+		if (err)
+			return err;
+
+		if (tlv.type == SR6_TLV_PADDING) {
+			*pad_size = tlv.len + sizeof(tlv);
+			*pad_off = cur_off;
+
+			if (*tlv_off == srh_off) {
+				*tlv_off = cur_off;
+				offset_valid = 1;
+			}
+			break;
+
+		} else if (tlv.type == SR6_TLV_HMAC) {
+			break;
+		}
+
+		cur_off += sizeof(tlv) + tlv.len;
+	} // we reached the padding or HMAC TLVs, or the end of the SRH
+
+	if (*pad_off == 0)
+		*pad_off = cur_off;
+
+	if (*tlv_off == -1)
+		*tlv_off = cur_off;
+	else if (!offset_valid)
+		return -EINVAL;
+
+	return 0;
+}
+
+__attribute__((always_inline))
+int add_tlv(struct __sk_buff *skb, struct ip6_srh_t *srh, uint32_t tlv_off,
+	    struct sr6_tlv_t *itlv, uint8_t tlv_size)
+{
+	uint32_t srh_off = (char *)srh - (char *)(long)skb->data;
+	uint8_t len_remaining, new_pad;
+	uint32_t pad_off = 0;
+	uint32_t pad_size = 0;
+	uint32_t partial_srh_len;
+	int err;
+
+	if (tlv_off != -1)
+		tlv_off += srh_off;
+
+	if (itlv->type == SR6_TLV_PADDING || itlv->type == SR6_TLV_HMAC)
+		return -EINVAL;
+
+	err = is_valid_tlv_boundary(skb, srh, &tlv_off, &pad_size, &pad_off);
+	if (err)
+		return err;
+
+	err = bpf_lwt_seg6_adjust_srh(skb, tlv_off, sizeof(*itlv) + itlv->len);
+	if (err)
+		return err;
+
+	err = bpf_lwt_seg6_store_bytes(skb, tlv_off, (void *)itlv, tlv_size);
+	if (err)
+		return err;
+
+	// the following can't be moved inside update_tlv_pad because the
+	// bpf verifier has some issues with it
+	pad_off += sizeof(*itlv) + itlv->len;
+	partial_srh_len = pad_off - srh_off;
+	len_remaining = partial_srh_len % 8;
+	new_pad = 8 - len_remaining;
+
+	if (new_pad == 1) // cannot pad for 1 byte only
+		new_pad = 9;
+	else if (new_pad == 8)
+		new_pad = 0;
+
+	return update_tlv_pad(skb, new_pad, pad_size, pad_off);
+}
+
+__attribute__((always_inline))
+int delete_tlv(struct __sk_buff *skb, struct ip6_srh_t *srh,
+	       uint32_t tlv_off)
+{
+	uint32_t srh_off = (char *)srh - (char *)(long)skb->data;
+	uint8_t len_remaining, new_pad;
+	uint32_t partial_srh_len;
+	uint32_t pad_off = 0;
+	uint32_t pad_size = 0;
+	struct sr6_tlv_t tlv;
+	int err;
+
+	tlv_off += srh_off;
+
+	err = is_valid_tlv_boundary(skb, srh, &tlv_off, &pad_size, &pad_off);
+	if (err)
+		return err;
+
+	err = bpf_skb_load_bytes(skb, tlv_off, &tlv, sizeof(tlv));
+	if (err)
+		return err;
+
+	err = bpf_lwt_seg6_adjust_srh(skb, tlv_off, -(sizeof(tlv) + tlv.len));
+	if (err)
+		return err;
+
+	pad_off -= sizeof(tlv) + tlv.len;
+	partial_srh_len = pad_off - srh_off;
+	len_remaining = partial_srh_len % 8;
+	new_pad = 8 - len_remaining;
+	if (new_pad == 1) // cannot pad for 1 byte only
+		new_pad = 9;
+	else if (new_pad == 8)
+		new_pad = 0;
+
+	return update_tlv_pad(skb, new_pad, pad_size, pad_off);
+}
+
+__attribute__((always_inline))
+int has_egr_tlv(struct __sk_buff *skb, struct ip6_srh_t *srh)
+{
+	int tlv_offset = sizeof(struct ip6_t) + sizeof(struct ip6_srh_t) +
+		((srh->first_segment + 1) << 4);
+	struct sr6_tlv_t tlv;
+
+	if (bpf_skb_load_bytes(skb, tlv_offset, &tlv, sizeof(struct sr6_tlv_t)))
+		return 0;
+
+	if (tlv.type == SR6_TLV_EGRESS && tlv.len == 18) {
+		struct ip6_addr_t egr_addr;
+
+		if (bpf_skb_load_bytes(skb, tlv_offset + 4, &egr_addr, 16))
+			return 0;
+
+		// check if egress TLV value is correct
+		if (ntohll(egr_addr.hi) == 0xfd00000000000000 &&
+				ntohll(egr_addr.lo) == 0x4)
+			return 1;
+	}
+
+	return 0;
+}
+
+// This function will push a SRH with segments fd00::1, fd00::2, fd00::3,
+// fd00::4
+SEC("encap_srh")
+int __encap_srh(struct __sk_buff *skb)
+{
+	bpf_printk("got pkt\n");
+	unsigned long long hi = 0xfd00000000000000;
+	struct ip6_addr_t *seg;
+	struct ip6_srh_t *srh;
+	char srh_buf[72]; // room for 4 segments
+	int err;
+
+	srh = (struct ip6_srh_t *)srh_buf;
+	srh->nexthdr = 0;
+	srh->hdrlen = 8;
+	srh->type = 4;
+	srh->segments_left = 3;
+	srh->first_segment = 3;
+	srh->flags = 0;
+	srh->tag = 0;
+
+	seg = (struct ip6_addr_t *)((char *)srh + sizeof(*srh));
+
+	#pragma clang loop unroll(full)
+	for (unsigned long long lo = 0; lo < 4; lo++) {
+		seg->lo = htonll(4 - lo);
+		seg->hi = htonll(hi);
+		seg = (struct ip6_addr_t *)((char *)seg + sizeof(*seg));
+	}
+
+	err = bpf_lwt_push_encap(skb, 0, (void *)srh, sizeof(srh_buf));
+	if (err)
+		return BPF_DROP;
+
+	return BPF_REDIRECT;
+}
+
+// Add an Egress TLV fc00::4, add the flag A,
+// and apply End.X action to fc42::1
+SEC("add_egr_x")
+int __add_egr_x(struct __sk_buff *skb)
+{
+	unsigned long long hi = 0xfc42000000000000;
+	unsigned long long lo = 0x1;
+	struct ip6_srh_t *srh = get_srh(skb);
+	uint8_t new_flags = SR6_FLAG_ALERT;
+	struct ip6_addr_t addr;
+	int err, offset;
+
+	if (srh == NULL)
+		return BPF_DROP;
+
+	uint8_t tlv[20] = {2, 18, 0, 0, 0xfd, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+			   0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x4};
+
+	err = add_tlv(skb, srh, (srh->hdrlen+1) << 3,
+		      (struct sr6_tlv_t *)&tlv, 20);
+	if (err)
+		return BPF_DROP;
+
+	offset = sizeof(struct ip6_t) + offsetof(struct ip6_srh_t, flags);
+	err = bpf_lwt_seg6_store_bytes(skb, offset,
+				       (void *)&new_flags, sizeof(new_flags));
+	if (err)
+		return BPF_DROP;
+
+	addr.lo = htonll(lo);
+	addr.hi = htonll(hi);
+	err = bpf_lwt_seg6_action(skb, SEG6_LOCAL_ACTION_END_X,
+				  (void *)&addr, sizeof(addr));
+	if (err)
+		return BPF_DROP;
+	return BPF_REDIRECT;
+}
+
+// Pop the Egress TLV, reset the flags, change the tag 2442 and finally do a
+// simple End action
+SEC("pop_egr")
+int __pop_egr(struct __sk_buff *skb)
+{
+	struct ip6_srh_t *srh = get_srh(skb);
+	uint16_t new_tag = bpf_htons(2442);
+	uint8_t new_flags = 0;
+	int err, offset;
+
+	if (srh == NULL)
+		return BPF_DROP;
+
+	if (srh->flags != SR6_FLAG_ALERT)
+		return BPF_DROP;
+
+	if (srh->hdrlen != 11) // 4 segments + Egress TLV + Padding TLV
+		return BPF_DROP;
+
+	if (!has_egr_tlv(skb, srh))
+		return BPF_DROP;
+
+	err = delete_tlv(skb, srh, 8 + (srh->first_segment + 1) * 16);
+	if (err)
+		return BPF_DROP;
+
+	offset = sizeof(struct ip6_t) + offsetof(struct ip6_srh_t, flags);
+	if (bpf_lwt_seg6_store_bytes(skb, offset, (void *)&new_flags,
+				     sizeof(new_flags)))
+		return BPF_DROP;
+
+	offset = sizeof(struct ip6_t) + offsetof(struct ip6_srh_t, tag);
+	if (bpf_lwt_seg6_store_bytes(skb, offset, (void *)&new_tag,
+				     sizeof(new_tag)))
+		return BPF_DROP;
+
+	return BPF_OK;
+}
+
+// Inspect if the Egress TLV and flag have been removed, if the tag is correct,
+// then apply a End.T action to reach the last segment
+SEC("inspect_t")
+int __inspect_t(struct __sk_buff *skb)
+{
+	struct ip6_srh_t *srh = get_srh(skb);
+	int table = 117;
+	int err;
+
+	if (srh == NULL)
+		return BPF_DROP;
+
+	if (srh->flags != 0)
+		return BPF_DROP;
+
+	if (srh->tag != bpf_htons(2442))
+		return BPF_DROP;
+
+	if (srh->hdrlen != 8) // 4 segments
+		return BPF_DROP;
+
+	err = bpf_lwt_seg6_action(skb, SEG6_LOCAL_ACTION_END_T,
+				  (void *)&table, sizeof(table));
+
+	if (err)
+		return BPF_DROP;
+
+	return BPF_REDIRECT;
+}
+
+char __license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/test_lwt_seg6local.sh b/tools/testing/selftests/bpf/test_lwt_seg6local.sh
new file mode 100755
index 000000000000..1c77994b5e71
--- /dev/null
+++ b/tools/testing/selftests/bpf/test_lwt_seg6local.sh
@@ -0,0 +1,140 @@
+#!/bin/bash
+# Connects 6 network namespaces through veths.
+# Each NS may have different IPv6 global scope addresses :
+#   NS1 ---- NS2 ---- NS3 ---- NS4 ---- NS5 ---- NS6
+# fb00::1           fd00::1  fd00::2  fd00::3  fb00::6
+#                   fc42::1           fd00::4
+#
+# All IPv6 packets going to fb00::/16 through NS2 will be encapsulated in a
+# IPv6 header with a Segment Routing Header, with segments :
+# 	fd00::1 -> fd00::2 -> fd00::3 -> fd00::4
+#
+# 3 fd00::/16 IPv6 addresses are binded to seg6local End.BPF actions :
+# - fd00::1 : add a TLV, change the flags and apply a End.X action to fc42::1
+# - fd00::2 : remove the TLV, change the flags, add a tag
+# - fd00::3 : apply an End.T action to fd00::4, through routing table 117
+#
+# fd00::4 is a simple Segment Routing node decapsulating the inner IPv6 packet.
+# Each End.BPF action will validate the operations applied on the SRH by the
+# previous BPF program in the chain, otherwise the packet is dropped.
+#
+# An UDP datagram is sent from fb00::1 to fb00::6. The test succeeds if this
+# datagram can be read on NS6 when binding to fb00::6.
+
+TMP_FILE="/tmp/selftest_lwt_seg6local.txt"
+
+cleanup()
+{
+	if [ "$?" = "0" ]; then
+		echo "selftests: test_lwt_seg6local [PASS]";
+	else
+		echo "selftests: test_lwt_seg6local [FAILED]";
+	fi
+
+	set +e
+	ip netns del ns1 2> /dev/null
+	ip netns del ns2 2> /dev/null
+	ip netns del ns3 2> /dev/null
+	ip netns del ns4 2> /dev/null
+	ip netns del ns5 2> /dev/null
+	ip netns del ns6 2> /dev/null
+	rm -f $TMP_FILE
+}
+
+set -e
+
+ip netns add ns1
+ip netns add ns2
+ip netns add ns3
+ip netns add ns4
+ip netns add ns5
+ip netns add ns6
+
+trap cleanup 0 2 3 6 9
+
+ip link add veth1 type veth peer name veth2
+ip link add veth3 type veth peer name veth4
+ip link add veth5 type veth peer name veth6
+ip link add veth7 type veth peer name veth8
+ip link add veth9 type veth peer name veth10
+
+ip link set veth1 netns ns1
+ip link set veth2 netns ns2
+ip link set veth3 netns ns2
+ip link set veth4 netns ns3
+ip link set veth5 netns ns3
+ip link set veth6 netns ns4
+ip link set veth7 netns ns4
+ip link set veth8 netns ns5
+ip link set veth9 netns ns5
+ip link set veth10 netns ns6
+
+ip netns exec ns1 ip link set dev veth1 up
+ip netns exec ns2 ip link set dev veth2 up
+ip netns exec ns2 ip link set dev veth3 up
+ip netns exec ns3 ip link set dev veth4 up
+ip netns exec ns3 ip link set dev veth5 up
+ip netns exec ns4 ip link set dev veth6 up
+ip netns exec ns4 ip link set dev veth7 up
+ip netns exec ns5 ip link set dev veth8 up
+ip netns exec ns5 ip link set dev veth9 up
+ip netns exec ns6 ip link set dev veth10 up
+ip netns exec ns6 ip link set dev lo up
+
+# All link scope addresses and routes required between veths
+ip netns exec ns1 ip -6 addr add fb00::12/16 dev veth1 scope link
+ip netns exec ns1 ip -6 route add fb00::21 dev veth1 scope link
+ip netns exec ns2 ip -6 addr add fb00::21/16 dev veth2 scope link
+ip netns exec ns2 ip -6 addr add fb00::34/16 dev veth3 scope link
+ip netns exec ns2 ip -6 route add fb00::43 dev veth3 scope link
+ip netns exec ns3 ip -6 route add fb00::65 dev veth5 scope link
+ip netns exec ns3 ip -6 addr add fb00::43/16 dev veth4 scope link
+ip netns exec ns3 ip -6 addr add fb00::56/16 dev veth5 scope link
+ip netns exec ns4 ip -6 addr add fb00::65/16 dev veth6 scope link
+ip netns exec ns4 ip -6 addr add fb00::78/16 dev veth7 scope link
+ip netns exec ns4 ip -6 route add fb00::87 dev veth7 scope link
+ip netns exec ns5 ip -6 addr add fb00::87/16 dev veth8 scope link
+ip netns exec ns5 ip -6 addr add fb00::910/16 dev veth9 scope link
+ip netns exec ns5 ip -6 route add fb00::109 dev veth9 scope link
+ip netns exec ns5 ip -6 route add fb00::109 table 117 dev veth9 scope link
+ip netns exec ns6 ip -6 addr add fb00::109/16 dev veth10 scope link
+
+ip netns exec ns1 ip -6 addr add fb00::1/16 dev lo
+ip netns exec ns1 ip -6 route add fb00::6 dev veth1 via fb00::21
+
+ip netns exec ns2 ip -6 route add fb00::6 encap bpf in obj test_lwt_seg6local.o sec encap_srh dev veth2
+ip netns exec ns2 ip -6 route add fd00::1 dev veth3 via fb00::43 scope link
+
+ip netns exec ns3 ip -6 route add fc42::1 dev veth5 via fb00::65
+ip netns exec ns3 ip -6 route add fd00::1 encap seg6local action End.BPF obj test_lwt_seg6local.o sec add_egr_x dev veth4
+
+ip netns exec ns4 ip -6 route add fd00::2 encap seg6local action End.BPF obj test_lwt_seg6local.o sec pop_egr dev veth6
+ip netns exec ns4 ip -6 addr add fc42::1 dev lo
+ip netns exec ns4 ip -6 route add fd00::3 dev veth7 via fb00::87
+
+ip netns exec ns5 ip -6 route add fd00::4 table 117 dev veth9 via fb00::109
+ip netns exec ns5 ip -6 route add fd00::3 encap seg6local action End.BPF obj test_lwt_seg6local.o sec inspect_t dev veth8
+
+ip netns exec ns6 ip -6 addr add fb00::6/16 dev lo
+ip netns exec ns6 ip -6 addr add fd00::4/16 dev lo
+
+ip netns exec ns1 sysctl net.ipv6.conf.all.forwarding=1 > /dev/null
+ip netns exec ns2 sysctl net.ipv6.conf.all.forwarding=1 > /dev/null
+ip netns exec ns3 sysctl net.ipv6.conf.all.forwarding=1 > /dev/null
+ip netns exec ns4 sysctl net.ipv6.conf.all.forwarding=1 > /dev/null
+ip netns exec ns5 sysctl net.ipv6.conf.all.forwarding=1 > /dev/null
+
+ip netns exec ns6 sysctl net.ipv6.conf.all.seg6_enabled=1 > /dev/null
+ip netns exec ns6 sysctl net.ipv6.conf.lo.seg6_enabled=1 > /dev/null
+ip netns exec ns6 sysctl net.ipv6.conf.veth10.seg6_enabled=1 > /dev/null
+
+ip netns exec ns6 nc -l -6 -u -d 7330 > $TMP_FILE &
+ip netns exec ns1 bash -c "echo 'foobar' | nc -w0 -6 -u -p 2121 -s fb00::1 fb00::6 7330"
+sleep 5 # wait enough time to ensure the UDP datagram arrived to the last segment
+kill -INT $!
+
+if [[ $(< $TMP_FILE) != "foobar" ]]; then
+	exit 1
+fi
+
+exit 0
-- 
2.16.1

^ permalink raw reply related

* [PATCH bpf-next v5 5/6] ipv6: sr: Add seg6local action End.BPF
From: Mathieu Xhonneux @ 2018-05-12 17:25 UTC (permalink / raw)
  To: netdev; +Cc: dlebrun, alexei.starovoitov
In-Reply-To: <cover.1526143526.git.m.xhonneux@gmail.com>

This patch adds the End.BPF action to the LWT seg6local infrastructure.
This action works like any other seg6local End action, meaning that an IPv6
header with SRH is needed, whose DA has to be equal to the SID of the
action. It will also advance the SRH to the next segment, the BPF program
does not have to take care of this.

Since the BPF program may not be a source of instability in the kernel, it
is important to ensure that the integrity of the packet is maintained
before yielding it back to the IPv6 layer. The hook hence keeps track if
the SRH has been altered through the helpers, and re-validates its
content if needed with seg6_validate_srh. The state kept for validation is
stored in a per-CPU buffer. The BPF program is not allowed to directly
write into the packet, and only some fields of the SRH can be altered
through the helper bpf_lwt_seg6_store_bytes.

Performances profiling has shown that the SRH re-validation does not induce
a significant overhead. If the altered SRH is deemed as invalid, the packet
is dropped.

This validation is also done before executing any action through
bpf_lwt_seg6_action, and will not be performed again if the SRH is not
modified after calling the action.

The BPF program may return 3 types of return codes:
    - BPF_OK: the End.BPF action will look up the next destination through
             seg6_lookup_nexthop.
    - BPF_REDIRECT: if an action has been executed through the
          bpf_lwt_seg6_action helper, the BPF program should return this
          value, as the skb's destination is already set and the default
          lookup should not be performed.
    - BPF_DROP : the packet will be dropped.

Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com>
Acked-by: David Lebrun <dlebrun@google.com>
---
 include/linux/bpf_types.h       |   1 +
 include/uapi/linux/bpf.h        |   1 +
 include/uapi/linux/seg6_local.h |   3 +
 kernel/bpf/verifier.c           |   1 +
 net/core/filter.c               |  25 +++++++
 net/ipv6/seg6_local.c           | 158 +++++++++++++++++++++++++++++++++++++++-
 tools/lib/bpf/libbpf.c          |   1 +
 7 files changed, 187 insertions(+), 3 deletions(-)

diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h
index cc9d7e031330..6a979f95f986 100644
--- a/include/linux/bpf_types.h
+++ b/include/linux/bpf_types.h
@@ -12,6 +12,7 @@ BPF_PROG_TYPE(BPF_PROG_TYPE_CGROUP_SOCK_ADDR, cg_sock_addr)
 BPF_PROG_TYPE(BPF_PROG_TYPE_LWT_IN, lwt_in)
 BPF_PROG_TYPE(BPF_PROG_TYPE_LWT_OUT, lwt_out)
 BPF_PROG_TYPE(BPF_PROG_TYPE_LWT_XMIT, lwt_xmit)
+BPF_PROG_TYPE(BPF_PROG_TYPE_LWT_SEG6LOCAL, lwt_seg6local)
 BPF_PROG_TYPE(BPF_PROG_TYPE_SOCK_OPS, sock_ops)
 BPF_PROG_TYPE(BPF_PROG_TYPE_SK_SKB, sk_skb)
 BPF_PROG_TYPE(BPF_PROG_TYPE_SK_MSG, sk_msg)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 0349c91329fd..c6a213075368 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -140,6 +140,7 @@ enum bpf_prog_type {
 	BPF_PROG_TYPE_SK_MSG,
 	BPF_PROG_TYPE_RAW_TRACEPOINT,
 	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
+	BPF_PROG_TYPE_LWT_SEG6LOCAL,
 };
 
 enum bpf_attach_type {
diff --git a/include/uapi/linux/seg6_local.h b/include/uapi/linux/seg6_local.h
index ef2d8c3e76c1..aadcc11fb918 100644
--- a/include/uapi/linux/seg6_local.h
+++ b/include/uapi/linux/seg6_local.h
@@ -25,6 +25,7 @@ enum {
 	SEG6_LOCAL_NH6,
 	SEG6_LOCAL_IIF,
 	SEG6_LOCAL_OIF,
+	SEG6_LOCAL_BPF,
 	__SEG6_LOCAL_MAX,
 };
 #define SEG6_LOCAL_MAX (__SEG6_LOCAL_MAX - 1)
@@ -59,6 +60,8 @@ enum {
 	SEG6_LOCAL_ACTION_END_AS	= 13,
 	/* forward to SR-unaware VNF with masquerading */
 	SEG6_LOCAL_ACTION_END_AM	= 14,
+	/* custom BPF action */
+	SEG6_LOCAL_ACTION_END_BPF	= 15,
 
 	__SEG6_LOCAL_ACTION_MAX,
 };
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index d92d9c37affd..c6b5eadcad16 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1262,6 +1262,7 @@ static bool may_access_direct_pkt_data(struct bpf_verifier_env *env,
 	switch (env->prog->type) {
 	case BPF_PROG_TYPE_LWT_IN:
 	case BPF_PROG_TYPE_LWT_OUT:
+	case BPF_PROG_TYPE_LWT_SEG6LOCAL:
 		/* dst_input() and dst_output() can't write for now */
 		if (t == BPF_WRITE)
 			return false;
diff --git a/net/core/filter.c b/net/core/filter.c
index 71434204b037..d69771e56d1f 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4847,6 +4847,21 @@ lwt_xmit_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 	}
 }
 
+static const struct bpf_func_proto *
+lwt_seg6local_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
+{
+	switch (func_id) {
+	case BPF_FUNC_lwt_seg6_store_bytes:
+		return &bpf_lwt_seg6_store_bytes_proto;
+	case BPF_FUNC_lwt_seg6_action:
+		return &bpf_lwt_seg6_action_proto;
+	case BPF_FUNC_lwt_seg6_adjust_srh:
+		return &bpf_lwt_seg6_adjust_srh_proto;
+	default:
+		return lwt_out_func_proto(func_id, prog);
+	}
+}
+
 static bool bpf_skb_is_valid_access(int off, int size, enum bpf_access_type type,
 				    const struct bpf_prog *prog,
 				    struct bpf_insn_access_aux *info)
@@ -6447,6 +6462,16 @@ const struct bpf_prog_ops lwt_xmit_prog_ops = {
 	.test_run		= bpf_prog_test_run_skb,
 };
 
+const struct bpf_verifier_ops lwt_seg6local_verifier_ops = {
+	.get_func_proto		= lwt_seg6local_func_proto,
+	.is_valid_access	= lwt_is_valid_access,
+	.convert_ctx_access	= bpf_convert_ctx_access,
+};
+
+const struct bpf_prog_ops lwt_seg6local_prog_ops = {
+	.test_run		= bpf_prog_test_run_skb,
+};
+
 const struct bpf_verifier_ops cg_sock_verifier_ops = {
 	.get_func_proto		= sock_filter_func_proto,
 	.is_valid_access	= sock_filter_is_valid_access,
diff --git a/net/ipv6/seg6_local.c b/net/ipv6/seg6_local.c
index ae68c1ef8fb0..2ac887da63e2 100644
--- a/net/ipv6/seg6_local.c
+++ b/net/ipv6/seg6_local.c
@@ -1,8 +1,9 @@
 /*
  *  SR-IPv6 implementation
  *
- *  Author:
+ *  Authors:
  *  David Lebrun <david.lebrun@uclouvain.be>
+ *  eBPF support: Mathieu Xhonneux <m.xhonneux@gmail.com>
  *
  *
  *  This program is free software; you can redistribute it and/or
@@ -32,6 +33,7 @@
 #endif
 #include <net/seg6_local.h>
 #include <linux/etherdevice.h>
+#include <linux/bpf.h>
 
 struct seg6_local_lwt;
 
@@ -42,6 +44,11 @@ struct seg6_action_desc {
 	int static_headroom;
 };
 
+struct bpf_lwt_prog {
+	struct bpf_prog *prog;
+	char *name;
+};
+
 struct seg6_local_lwt {
 	int action;
 	struct ipv6_sr_hdr *srh;
@@ -50,6 +57,7 @@ struct seg6_local_lwt {
 	struct in6_addr nh6;
 	int iif;
 	int oif;
+	struct bpf_lwt_prog bpf;
 
 	int headroom;
 	struct seg6_action_desc *desc;
@@ -451,6 +459,69 @@ static int input_action_end_b6_encap(struct sk_buff *skb,
 
 DEFINE_PER_CPU(struct seg6_bpf_srh_state, seg6_bpf_srh_states);
 
+static int input_action_end_bpf(struct sk_buff *skb,
+				struct seg6_local_lwt *slwt)
+{
+	struct seg6_bpf_srh_state *srh_state =
+		this_cpu_ptr(&seg6_bpf_srh_states);
+	struct seg6_bpf_srh_state local_srh_state;
+	struct ipv6_sr_hdr *srh;
+	int srhoff = 0;
+	int ret;
+
+	srh = get_and_validate_srh(skb);
+	if (!srh)
+		goto drop;
+	advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
+
+	/* preempt_disable is needed to protect the per-CPU buffer srh_state,
+	 * which is also accessed by the bpf_lwt_seg6_* helpers
+	 */
+	preempt_disable();
+	srh_state->hdrlen = srh->hdrlen << 3;
+	srh_state->valid = 1;
+
+	rcu_read_lock();
+	bpf_compute_data_pointers(skb);
+	ret = bpf_prog_run_save_cb(slwt->bpf.prog, skb);
+	rcu_read_unlock();
+
+	local_srh_state = *srh_state;
+	preempt_enable();
+
+	switch (ret) {
+	case BPF_OK:
+	case BPF_REDIRECT:
+		break;
+	case BPF_DROP:
+		goto drop;
+	default:
+		pr_warn_once("bpf-seg6local: Illegal return value %u\n", ret);
+		goto drop;
+	}
+
+	if (unlikely((local_srh_state.hdrlen & 7) != 0))
+		goto drop;
+
+	if (ipv6_find_hdr(skb, &srhoff, IPPROTO_ROUTING, NULL, NULL) < 0)
+		goto drop;
+	srh = (struct ipv6_sr_hdr *)(skb->data + srhoff);
+	srh->hdrlen = (u8)(local_srh_state.hdrlen >> 3);
+
+	if (!local_srh_state.valid &&
+	    unlikely(!seg6_validate_srh(srh, (srh->hdrlen + 1) << 3)))
+		goto drop;
+
+	if (ret != BPF_REDIRECT)
+		seg6_lookup_nexthop(skb, NULL, 0);
+
+	return dst_input(skb);
+
+drop:
+	kfree_skb(skb);
+	return -EINVAL;
+}
+
 static struct seg6_action_desc seg6_action_table[] = {
 	{
 		.action		= SEG6_LOCAL_ACTION_END,
@@ -497,7 +568,13 @@ static struct seg6_action_desc seg6_action_table[] = {
 		.attrs		= (1 << SEG6_LOCAL_SRH),
 		.input		= input_action_end_b6_encap,
 		.static_headroom	= sizeof(struct ipv6hdr),
-	}
+	},
+	{
+		.action		= SEG6_LOCAL_ACTION_END_BPF,
+		.attrs		= (1 << SEG6_LOCAL_BPF),
+		.input		= input_action_end_bpf,
+	},
+
 };
 
 static struct seg6_action_desc *__get_action_desc(int action)
@@ -542,6 +619,7 @@ static const struct nla_policy seg6_local_policy[SEG6_LOCAL_MAX + 1] = {
 				    .len = sizeof(struct in6_addr) },
 	[SEG6_LOCAL_IIF]	= { .type = NLA_U32 },
 	[SEG6_LOCAL_OIF]	= { .type = NLA_U32 },
+	[SEG6_LOCAL_BPF]	= { .type = NLA_NESTED },
 };
 
 static int parse_nla_srh(struct nlattr **attrs, struct seg6_local_lwt *slwt)
@@ -719,6 +797,71 @@ static int cmp_nla_oif(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
 	return 0;
 }
 
+#define MAX_PROG_NAME 256
+static const struct nla_policy bpf_prog_policy[LWT_BPF_PROG_MAX + 1] = {
+	[LWT_BPF_PROG_FD]   = { .type = NLA_U32, },
+	[LWT_BPF_PROG_NAME] = { .type = NLA_NUL_STRING,
+				.len = MAX_PROG_NAME },
+};
+
+static int parse_nla_bpf(struct nlattr **attrs, struct seg6_local_lwt *slwt)
+{
+	struct nlattr *tb[LWT_BPF_PROG_MAX + 1];
+	struct bpf_prog *p;
+	int ret;
+	u32 fd;
+
+	ret = nla_parse_nested(tb, LWT_BPF_PROG_MAX, attrs[SEG6_LOCAL_BPF],
+			       bpf_prog_policy, NULL);
+	if (ret < 0)
+		return ret;
+
+	if (!tb[LWT_BPF_PROG_FD] || !tb[LWT_BPF_PROG_NAME])
+		return -EINVAL;
+
+	slwt->bpf.name = nla_memdup(tb[LWT_BPF_PROG_NAME], GFP_KERNEL);
+	if (!slwt->bpf.name)
+		return -ENOMEM;
+
+	fd = nla_get_u32(tb[LWT_BPF_PROG_FD]);
+	p = bpf_prog_get_type(fd, BPF_PROG_TYPE_LWT_SEG6LOCAL);
+	if (IS_ERR(p))
+		return PTR_ERR(p);
+
+	slwt->bpf.prog = p;
+
+	return 0;
+}
+
+static int put_nla_bpf(struct sk_buff *skb, struct seg6_local_lwt *slwt)
+{
+	struct nlattr *nest;
+
+	if (!slwt->bpf.prog)
+		return 0;
+
+	nest = nla_nest_start(skb, SEG6_LOCAL_BPF);
+	if (!nest)
+		return -EMSGSIZE;
+
+	if (slwt->bpf.name &&
+	    nla_put_string(skb, LWT_BPF_PROG_NAME, slwt->bpf.name))
+		return -EMSGSIZE;
+
+	return nla_nest_end(skb, nest);
+}
+
+static int cmp_nla_bpf(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
+{
+	if (!a->bpf.name && !b->bpf.name)
+		return 0;
+
+	if (!a->bpf.name || !b->bpf.name)
+		return 1;
+
+	return strcmp(a->bpf.name, b->bpf.name);
+}
+
 struct seg6_action_param {
 	int (*parse)(struct nlattr **attrs, struct seg6_local_lwt *slwt);
 	int (*put)(struct sk_buff *skb, struct seg6_local_lwt *slwt);
@@ -749,6 +892,11 @@ static struct seg6_action_param seg6_action_params[SEG6_LOCAL_MAX + 1] = {
 	[SEG6_LOCAL_OIF]	= { .parse = parse_nla_oif,
 				    .put = put_nla_oif,
 				    .cmp = cmp_nla_oif },
+
+	[SEG6_LOCAL_BPF]	= { .parse = parse_nla_bpf,
+				    .put = put_nla_bpf,
+				    .cmp = cmp_nla_bpf },
+
 };
 
 static int parse_nla_action(struct nlattr **attrs, struct seg6_local_lwt *slwt)
@@ -797,7 +945,6 @@ static int seg6_local_build_state(struct nlattr *nla, unsigned int family,
 
 	err = nla_parse_nested(tb, SEG6_LOCAL_MAX, nla, seg6_local_policy,
 			       extack);
-
 	if (err < 0)
 		return err;
 
@@ -886,6 +1033,11 @@ static int seg6_local_get_encap_size(struct lwtunnel_state *lwt)
 	if (attrs & (1 << SEG6_LOCAL_OIF))
 		nlsize += nla_total_size(4);
 
+	if (attrs & (1 << SEG6_LOCAL_BPF))
+		nlsize += nla_total_size(sizeof(struct nlattr)) +
+		       nla_total_size(MAX_PROG_NAME) +
+		       nla_total_size(4);
+
 	return nlsize;
 }
 
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index df54c4c9e48a..68865dc83aea 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -1450,6 +1450,7 @@ static bool bpf_prog_type__needs_kver(enum bpf_prog_type type)
 	case BPF_PROG_TYPE_LWT_IN:
 	case BPF_PROG_TYPE_LWT_OUT:
 	case BPF_PROG_TYPE_LWT_XMIT:
+	case BPF_PROG_TYPE_LWT_SEG6LOCAL:
 	case BPF_PROG_TYPE_SOCK_OPS:
 	case BPF_PROG_TYPE_SK_SKB:
 	case BPF_PROG_TYPE_CGROUP_DEVICE:
-- 
2.16.1

^ permalink raw reply related

* [PATCH bpf-next v5 4/6] bpf: Split lwt inout verifier structures
From: Mathieu Xhonneux @ 2018-05-12 17:25 UTC (permalink / raw)
  To: netdev; +Cc: dlebrun, alexei.starovoitov
In-Reply-To: <cover.1526143526.git.m.xhonneux@gmail.com>

The new bpf_lwt_push_encap helper should only be accessible within the
LWT BPF IN hook, and not the OUT one, as this may lead to a skb under
panic.

At the moment, both LWT BPF IN and OUT share the same list of helpers,
whose calls are authorized by the verifier. This patch separates the
verifier ops for the IN and OUT hooks, and allows the IN hook to call the
bpf_lwt_push_encap helper.

This patch is also the occasion to put all lwt_*_func_proto functions
together for clarity. At the moment, socks_op_func_proto is in the middle
of lwt_inout_func_proto and lwt_xmit_func_proto.

Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com>
Acked-by: David Lebrun <dlebrun@google.com>
---
 include/linux/bpf_types.h |  4 +--
 net/core/filter.c         | 83 +++++++++++++++++++++++++++++------------------
 2 files changed, 54 insertions(+), 33 deletions(-)

diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h
index d7df1b323082..cc9d7e031330 100644
--- a/include/linux/bpf_types.h
+++ b/include/linux/bpf_types.h
@@ -9,8 +9,8 @@ BPF_PROG_TYPE(BPF_PROG_TYPE_XDP, xdp)
 BPF_PROG_TYPE(BPF_PROG_TYPE_CGROUP_SKB, cg_skb)
 BPF_PROG_TYPE(BPF_PROG_TYPE_CGROUP_SOCK, cg_sock)
 BPF_PROG_TYPE(BPF_PROG_TYPE_CGROUP_SOCK_ADDR, cg_sock_addr)
-BPF_PROG_TYPE(BPF_PROG_TYPE_LWT_IN, lwt_inout)
-BPF_PROG_TYPE(BPF_PROG_TYPE_LWT_OUT, lwt_inout)
+BPF_PROG_TYPE(BPF_PROG_TYPE_LWT_IN, lwt_in)
+BPF_PROG_TYPE(BPF_PROG_TYPE_LWT_OUT, lwt_out)
 BPF_PROG_TYPE(BPF_PROG_TYPE_LWT_XMIT, lwt_xmit)
 BPF_PROG_TYPE(BPF_PROG_TYPE_SOCK_OPS, sock_ops)
 BPF_PROG_TYPE(BPF_PROG_TYPE_SK_SKB, sk_skb)
diff --git a/net/core/filter.c b/net/core/filter.c
index 67b4ab4ec404..71434204b037 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4715,33 +4715,6 @@ xdp_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 	}
 }
 
-static const struct bpf_func_proto *
-lwt_inout_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
-{
-	switch (func_id) {
-	case BPF_FUNC_skb_load_bytes:
-		return &bpf_skb_load_bytes_proto;
-	case BPF_FUNC_skb_pull_data:
-		return &bpf_skb_pull_data_proto;
-	case BPF_FUNC_csum_diff:
-		return &bpf_csum_diff_proto;
-	case BPF_FUNC_get_cgroup_classid:
-		return &bpf_get_cgroup_classid_proto;
-	case BPF_FUNC_get_route_realm:
-		return &bpf_get_route_realm_proto;
-	case BPF_FUNC_get_hash_recalc:
-		return &bpf_get_hash_recalc_proto;
-	case BPF_FUNC_perf_event_output:
-		return &bpf_skb_event_output_proto;
-	case BPF_FUNC_get_smp_processor_id:
-		return &bpf_get_smp_processor_id_proto;
-	case BPF_FUNC_skb_under_cgroup:
-		return &bpf_skb_under_cgroup_proto;
-	default:
-		return bpf_base_func_proto(func_id);
-	}
-}
-
 static const struct bpf_func_proto *
 sock_ops_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 {
@@ -4801,6 +4774,44 @@ sk_skb_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 	}
 }
 
+static const struct bpf_func_proto *
+lwt_out_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
+{
+	switch (func_id) {
+	case BPF_FUNC_skb_load_bytes:
+		return &bpf_skb_load_bytes_proto;
+	case BPF_FUNC_skb_pull_data:
+		return &bpf_skb_pull_data_proto;
+	case BPF_FUNC_csum_diff:
+		return &bpf_csum_diff_proto;
+	case BPF_FUNC_get_cgroup_classid:
+		return &bpf_get_cgroup_classid_proto;
+	case BPF_FUNC_get_route_realm:
+		return &bpf_get_route_realm_proto;
+	case BPF_FUNC_get_hash_recalc:
+		return &bpf_get_hash_recalc_proto;
+	case BPF_FUNC_perf_event_output:
+		return &bpf_skb_event_output_proto;
+	case BPF_FUNC_get_smp_processor_id:
+		return &bpf_get_smp_processor_id_proto;
+	case BPF_FUNC_skb_under_cgroup:
+		return &bpf_skb_under_cgroup_proto;
+	default:
+		return bpf_base_func_proto(func_id);
+	}
+}
+
+static const struct bpf_func_proto *
+lwt_in_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
+{
+	switch (func_id) {
+	case BPF_FUNC_lwt_push_encap:
+		return &bpf_lwt_push_encap_proto;
+	default:
+		return lwt_out_func_proto(func_id, prog);
+	}
+}
+
 static const struct bpf_func_proto *
 lwt_xmit_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 {
@@ -4832,7 +4843,7 @@ lwt_xmit_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 	case BPF_FUNC_set_hash_invalid:
 		return &bpf_set_hash_invalid_proto;
 	default:
-		return lwt_inout_func_proto(func_id, prog);
+		return lwt_out_func_proto(func_id, prog);
 	}
 }
 
@@ -6405,13 +6416,23 @@ const struct bpf_prog_ops cg_skb_prog_ops = {
 	.test_run		= bpf_prog_test_run_skb,
 };
 
-const struct bpf_verifier_ops lwt_inout_verifier_ops = {
-	.get_func_proto		= lwt_inout_func_proto,
+const struct bpf_verifier_ops lwt_in_verifier_ops = {
+	.get_func_proto		= lwt_in_func_proto,
+	.is_valid_access	= lwt_is_valid_access,
+	.convert_ctx_access	= bpf_convert_ctx_access,
+};
+
+const struct bpf_prog_ops lwt_in_prog_ops = {
+	.test_run		= bpf_prog_test_run_skb,
+};
+
+const struct bpf_verifier_ops lwt_out_verifier_ops = {
+	.get_func_proto		= lwt_out_func_proto,
 	.is_valid_access	= lwt_is_valid_access,
 	.convert_ctx_access	= bpf_convert_ctx_access,
 };
 
-const struct bpf_prog_ops lwt_inout_prog_ops = {
+const struct bpf_prog_ops lwt_out_prog_ops = {
 	.test_run		= bpf_prog_test_run_skb,
 };
 
-- 
2.16.1

^ permalink raw reply related

* [PATCH bpf-next v5 3/6] bpf: Add IPv6 Segment Routing helpers
From: Mathieu Xhonneux @ 2018-05-12 17:25 UTC (permalink / raw)
  To: netdev; +Cc: dlebrun, alexei.starovoitov
In-Reply-To: <cover.1526143526.git.m.xhonneux@gmail.com>

The BPF seg6local hook should be powerful enough to enable users to
implement most of the use-cases one could think of. After some thinking,
we figured out that the following actions should be possible on a SRv6
packet, requiring 3 specific helpers :
    - bpf_lwt_seg6_store_bytes: Modify non-sensitive fields of the SRH
    - bpf_lwt_seg6_adjust_srh: Allow to grow or shrink a SRH
                               (to add/delete TLVs)
    - bpf_lwt_seg6_action: Apply some SRv6 network programming actions
                           (specifically End.X, End.T, End.B6 and
                            End.B6.Encap)

The specifications of these helpers are provided in the patch (see
include/uapi/linux/bpf.h).

The non-sensitive fields of the SRH are the following : flags, tag and
TLVs. The other fields can not be modified, to maintain the SRH
integrity. Flags, tag and TLVs can easily be modified as their validity
can be checked afterwards via seg6_validate_srh. It is not allowed to
modify the segments directly. If one wants to add segments on the path,
he should stack a new SRH using the End.B6 action via
bpf_lwt_seg6_action.

Growing, shrinking or editing TLVs via the helpers will flag the SRH as
invalid, and it will have to be re-validated before re-entering the IPv6
layer. This flag is stored in a per-CPU buffer, along with the current
header length in bytes.

Storing the SRH len in bytes in the control block is mandatory when using
bpf_lwt_seg6_adjust_srh. The Header Ext. Length field contains the SRH
len rounded to 8 bytes (a padding TLV can be inserted to ensure the 8-bytes
boundary). When adding/deleting TLVs within the BPF program, the SRH may
temporary be in an invalid state where its length cannot be rounded to 8
bytes without remainder, hence the need to store the length in bytes
separately. The caller of the BPF program can then ensure that the SRH's
final length is valid using this value. Again, a final SRH modified by a
BPF program which doesn’t respect the 8-bytes boundary will be discarded
as it will be considered as invalid.

Finally, a fourth helper is provided, bpf_lwt_push_encap, which is
available from the LWT BPF IN hook, but not from the seg6local BPF one.
This helper allows to encapsulate a Segment Routing Header (either with
a new outer IPv6 header, or by inlining it directly in the existing IPv6
header) into a non-SRv6 packet. This helper is required if we want to
offer the possibility to dynamically encapsulate a SRH for non-SRv6 packet,
as the BPF seg6local hook only works on traffic already containing a SRH.
This is the BPF equivalent of the seg6 LWT infrastructure, which achieves
the same purpose but with a static SRH per route.

These helpers require CONFIG_IPV6=y (and not =m).

Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com>
Acked-by: David Lebrun <dlebrun@google.com>
---
 include/net/seg6_local.h |   8 ++
 include/uapi/linux/bpf.h |  97 +++++++++++++++-
 net/core/filter.c        | 282 +++++++++++++++++++++++++++++++++++++++++++----
 net/ipv6/Kconfig         |   5 +
 net/ipv6/seg6_local.c    |   2 +
 5 files changed, 369 insertions(+), 25 deletions(-)

diff --git a/include/net/seg6_local.h b/include/net/seg6_local.h
index 57498b23085d..661fd5b4d3e0 100644
--- a/include/net/seg6_local.h
+++ b/include/net/seg6_local.h
@@ -15,10 +15,18 @@
 #ifndef _NET_SEG6_LOCAL_H
 #define _NET_SEG6_LOCAL_H
 
+#include <linux/percpu.h>
 #include <linux/net.h>
 #include <linux/ipv6.h>
 
 extern int seg6_lookup_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr,
 			       u32 tbl_id);
 
+struct seg6_bpf_srh_state {
+	bool valid;
+	u16 hdrlen;
+};
+
+DECLARE_PER_CPU(struct seg6_bpf_srh_state, seg6_bpf_srh_states);
+
 #endif
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 02e4112510f8..0349c91329fd 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -1828,7 +1828,6 @@ union bpf_attr {
  * 	Return
  * 		0 on success, or a negative error in case of failure.
  *
- *
  * int bpf_fib_lookup(void *ctx, struct bpf_fib_lookup *params, int plen, u32 flags)
  *	Description
  *		Do FIB lookup in kernel tables using parameters in *params*.
@@ -1855,6 +1854,90 @@ union bpf_attr {
  *             Egress device index on success, 0 if packet needs to continue
  *             up the stack for further processing or a negative error in case
  *             of failure.
+ *
+ * int bpf_lwt_push_encap(struct sk_buff *skb, u32 type, void *hdr, u32 len)
+ *	Description
+ *		Encapsulate the packet associated to *skb* within a Layer 3
+ *		protocol header. This header is provided in the buffer at
+ *		address *hdr*, with *len* its size in bytes. *type* indicates
+ *		the protocol of the header and can be one of:
+ *
+ *		**BPF_LWT_ENCAP_SEG6**
+ *			IPv6 encapsulation with Segment Routing Header
+ *			(**struct ipv6_sr_hdr**). *hdr* only contains the SRH,
+ *			the IPv6 header is computed by the kernel.
+ *		**BPF_LWT_ENCAP_SEG6_INLINE**
+ *			Only works if *skb* contains an IPv6 packet. Insert a
+ *			Segment Routing Header (**struct ipv6_sr_hdr**) inside
+ *			the IPv6 header.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ *	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_lwt_seg6_store_bytes(struct sk_buff *skb, u32 offset, const void *from, u32 len)
+ *	Description
+ *		Store *len* bytes from address *from* into the packet
+ *		associated to *skb*, at *offset*. Only the flags, tag and TLVs
+ *		inside the outermost IPv6 Segment Routing Header can be
+ *		modified through this helper.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ *	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_lwt_seg6_adjust_srh(struct sk_buff *skb, u32 offset, s32 delta)
+ *	Description
+ *		Adjust the size allocated to TLVs in the outermost IPv6
+ *		Segment Routing Header contained in the packet associated to
+ *		*skb*, at position *offset* by *delta* bytes. Only offsets
+ *		after the segments are accepted. *delta* can be as well
+ *		positive (growing) as negative (shrinking).
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ *	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_lwt_seg6_action(struct sk_buff *skb, u32 action, void *param, u32 param_len)
+ *	Description
+ *		Apply an IPv6 Segment Routing action of type *action* to the
+ *		packet associated to *skb*. Each action takes a parameter
+ *		contained at address *param*, and of length *param_len* bytes.
+ *		*action* can be one of:
+ *
+ *		**SEG6_LOCAL_ACTION_END_X**
+ *			End.X action: Endpoint with Layer-3 cross-connect.
+ *			Type of *param*: **struct in6_addr**.
+ *		**SEG6_LOCAL_ACTION_END_T**
+ *			End.T action: Endpoint with specific IPv6 table lookup.
+ *			Type of *param*: **int**.
+ *		**SEG6_LOCAL_ACTION_END_B6**
+ *			End.B6 action: Endpoint bound to an SRv6 policy.
+ *			Type of param: **struct ipv6_sr_hdr**.
+ *		**SEG6_LOCAL_ACTION_END_B6_ENCAP**
+ *			End.B6.Encap action: Endpoint bound to an SRv6
+ *			encapsulation policy.
+ *			Type of param: **struct ipv6_sr_hdr**.
+ *
+ * 		A call to this helper is susceptible to change the underlaying
+ * 		packet buffer. Therefore, at load time, all checks on pointers
+ * 		previously done by the verifier are invalidated and must be
+ * 		performed again, if the helper is used in combination with
+ * 		direct packet access.
+ *	Return
+ * 		0 on success, or a negative error in case of failure.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -1926,7 +2009,11 @@ union bpf_attr {
 	FN(skb_get_xfrm_state),		\
 	FN(get_stack),			\
 	FN(skb_load_bytes_relative),	\
-	FN(fib_lookup),
+	FN(fib_lookup),			\
+	FN(lwt_push_encap),		\
+	FN(lwt_seg6_store_bytes),	\
+	FN(lwt_seg6_adjust_srh),	\
+	FN(lwt_seg6_action),
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call
@@ -1993,6 +2080,12 @@ enum bpf_hdr_start_off {
 	BPF_HDR_START_NET,
 };
 
+/* Encapsulation type for BPF_FUNC_lwt_push_encap helper. */
+enum bpf_lwt_encap_mode {
+	BPF_LWT_ENCAP_SEG6,
+	BPF_LWT_ENCAP_SEG6_INLINE
+};
+
 /* user accessible mirror of in-kernel sk_buff.
  * new fields can only be added to the end of this structure
  */
diff --git a/net/core/filter.c b/net/core/filter.c
index ca60d2872da4..67b4ab4ec404 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -64,6 +64,10 @@
 #include <net/ip_fib.h>
 #include <net/flow.h>
 #include <net/arp.h>
+#include <net/ipv6.h>
+#include <linux/seg6_local.h>
+#include <net/seg6.h>
+#include <net/seg6_local.h>
 
 /**
  *	sk_filter_trim_cap - run a packet through a socket filter
@@ -3326,28 +3330,6 @@ static const struct bpf_func_proto bpf_xdp_redirect_map_proto = {
 	.arg3_type      = ARG_ANYTHING,
 };
 
-bool bpf_helper_changes_pkt_data(void *func)
-{
-	if (func == bpf_skb_vlan_push ||
-	    func == bpf_skb_vlan_pop ||
-	    func == bpf_skb_store_bytes ||
-	    func == bpf_skb_change_proto ||
-	    func == bpf_skb_change_head ||
-	    func == bpf_skb_change_tail ||
-	    func == bpf_skb_adjust_room ||
-	    func == bpf_skb_pull_data ||
-	    func == bpf_clone_redirect ||
-	    func == bpf_l3_csum_replace ||
-	    func == bpf_l4_csum_replace ||
-	    func == bpf_xdp_adjust_head ||
-	    func == bpf_xdp_adjust_meta ||
-	    func == bpf_msg_pull_data ||
-	    func == bpf_xdp_adjust_tail)
-		return true;
-
-	return false;
-}
-
 static unsigned long bpf_skb_copy(void *dst_buff, const void *skb,
 				  unsigned long off, unsigned long len)
 {
@@ -4295,6 +4277,261 @@ static const struct bpf_func_proto bpf_skb_fib_lookup_proto = {
 	.arg4_type	= ARG_ANYTHING,
 };
 
+#if IS_ENABLED(CONFIG_IPV6_SEG6_BPF)
+static int bpf_push_seg6_encap(struct sk_buff *skb, u32 type, void *hdr, u32 len)
+{
+	int err;
+	struct ipv6_sr_hdr *srh = (struct ipv6_sr_hdr *)hdr;
+
+	if (!seg6_validate_srh(srh, len))
+		return -EINVAL;
+
+	switch (type) {
+	case BPF_LWT_ENCAP_SEG6_INLINE:
+		if (skb->protocol != htons(ETH_P_IPV6))
+			return -EBADMSG;
+
+		err = seg6_do_srh_inline(skb, srh);
+		break;
+	case BPF_LWT_ENCAP_SEG6:
+		skb_reset_inner_headers(skb);
+		skb->encapsulation = 1;
+		err = seg6_do_srh_encap(skb, srh, IPPROTO_IPV6);
+		break;
+	default:
+		return -EINVAL;
+	}
+	if (err)
+		return err;
+
+	ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
+	skb_set_transport_header(skb, sizeof(struct ipv6hdr));
+
+	return seg6_lookup_nexthop(skb, NULL, 0);
+}
+#endif /* CONFIG_IPV6_SEG6_BPF */
+
+BPF_CALL_4(bpf_lwt_push_encap, struct sk_buff *, skb, u32, type, void *, hdr,
+	   u32, len)
+{
+	switch (type) {
+#if IS_ENABLED(CONFIG_IPV6_SEG6_BPF)
+	case BPF_LWT_ENCAP_SEG6:
+	case BPF_LWT_ENCAP_SEG6_INLINE:
+		return bpf_push_seg6_encap(skb, type, hdr, len);
+#endif
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct bpf_func_proto bpf_lwt_push_encap_proto = {
+	.func		= bpf_lwt_push_encap,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg2_type	= ARG_ANYTHING,
+	.arg3_type	= ARG_PTR_TO_MEM,
+	.arg4_type	= ARG_CONST_SIZE
+};
+
+BPF_CALL_4(bpf_lwt_seg6_store_bytes, struct sk_buff *, skb, u32, offset,
+	   const void *, from, u32, len)
+{
+#if IS_ENABLED(CONFIG_IPV6_SEG6_BPF)
+	struct seg6_bpf_srh_state *srh_state =
+		this_cpu_ptr(&seg6_bpf_srh_states);
+	void *srh_tlvs, *srh_end, *ptr;
+	struct ipv6_sr_hdr *srh;
+	int srhoff = 0;
+
+	if (ipv6_find_hdr(skb, &srhoff, IPPROTO_ROUTING, NULL, NULL) < 0)
+		return -EINVAL;
+
+	srh = (struct ipv6_sr_hdr *)(skb->data + srhoff);
+	srh_tlvs = (void *)((char *)srh + ((srh->first_segment + 1) << 4));
+	srh_end = (void *)((char *)srh + sizeof(*srh) + srh_state->hdrlen);
+
+	ptr = skb->data + offset;
+	if (ptr >= srh_tlvs && ptr + len <= srh_end)
+		srh_state->valid = 0;
+	else if (ptr < (void *)&srh->flags ||
+		 ptr + len > (void *)&srh->segments)
+		return -EFAULT;
+
+	if (unlikely(bpf_try_make_writable(skb, offset + len)))
+		return -EFAULT;
+
+	memcpy(ptr, from, len);
+	return 0;
+#else /* CONFIG_IPV6_SEG6_BPF */
+	return -EOPNOTSUPP;
+#endif
+}
+
+static const struct bpf_func_proto bpf_lwt_seg6_store_bytes_proto = {
+	.func		= bpf_lwt_seg6_store_bytes,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg2_type	= ARG_ANYTHING,
+	.arg3_type	= ARG_PTR_TO_MEM,
+	.arg4_type	= ARG_CONST_SIZE
+};
+
+BPF_CALL_4(bpf_lwt_seg6_action, struct sk_buff *, skb,
+	   u32, action, void *, param, u32, param_len)
+{
+#if IS_ENABLED(CONFIG_IPV6_SEG6_BPF)
+	struct seg6_bpf_srh_state *srh_state =
+		this_cpu_ptr(&seg6_bpf_srh_states);
+	struct ipv6_sr_hdr *srh;
+	int srhoff = 0;
+	int err;
+
+	if (ipv6_find_hdr(skb, &srhoff, IPPROTO_ROUTING, NULL, NULL) < 0)
+		return -EINVAL;
+	srh = (struct ipv6_sr_hdr *)(skb->data + srhoff);
+
+	if (!srh_state->valid) {
+		if (unlikely((srh_state->hdrlen & 7) != 0))
+			return -EBADMSG;
+
+		srh->hdrlen = (u8)(srh_state->hdrlen >> 3);
+		if (unlikely(!seg6_validate_srh(srh, (srh->hdrlen + 1) << 3)))
+			return -EBADMSG;
+
+		srh_state->valid = 1;
+	}
+
+	switch (action) {
+	case SEG6_LOCAL_ACTION_END_X:
+		if (param_len != sizeof(struct in6_addr))
+			return -EINVAL;
+		return seg6_lookup_nexthop(skb, (struct in6_addr *)param, 0);
+	case SEG6_LOCAL_ACTION_END_T:
+		if (param_len != sizeof(int))
+			return -EINVAL;
+		return seg6_lookup_nexthop(skb, NULL, *(int *)param);
+	case SEG6_LOCAL_ACTION_END_B6:
+		err = bpf_push_seg6_encap(skb, BPF_LWT_ENCAP_SEG6_INLINE,
+					  param, param_len);
+		if (!err)
+			srh_state->hdrlen =
+				((struct ipv6_sr_hdr *)param)->hdrlen << 3;
+		return err;
+	case SEG6_LOCAL_ACTION_END_B6_ENCAP:
+		err = bpf_push_seg6_encap(skb, BPF_LWT_ENCAP_SEG6,
+					  param, param_len);
+		if (!err)
+			srh_state->hdrlen =
+				((struct ipv6_sr_hdr *)param)->hdrlen << 3;
+		return err;
+	default:
+		return -EINVAL;
+	}
+#else /* CONFIG_IPV6_SEG6_BPF */
+	return -EOPNOTSUPP;
+#endif
+}
+
+static const struct bpf_func_proto bpf_lwt_seg6_action_proto = {
+	.func		= bpf_lwt_seg6_action,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg2_type	= ARG_ANYTHING,
+	.arg3_type	= ARG_PTR_TO_MEM,
+	.arg4_type	= ARG_CONST_SIZE
+};
+
+BPF_CALL_3(bpf_lwt_seg6_adjust_srh, struct sk_buff *, skb, u32, offset,
+	   s32, len)
+{
+#if IS_ENABLED(CONFIG_IPV6_SEG6_BPF)
+	struct seg6_bpf_srh_state *srh_state =
+		this_cpu_ptr(&seg6_bpf_srh_states);
+	void *srh_end, *srh_tlvs, *ptr;
+	struct ipv6_sr_hdr *srh;
+	struct ipv6hdr *hdr;
+	int srhoff = 0;
+	int ret;
+
+	if (ipv6_find_hdr(skb, &srhoff, IPPROTO_ROUTING, NULL, NULL) < 0)
+		return -EINVAL;
+	srh = (struct ipv6_sr_hdr *)(skb->data + srhoff);
+
+	srh_tlvs = (void *)((unsigned char *)srh + sizeof(*srh) +
+			((srh->first_segment + 1) << 4));
+	srh_end = (void *)((unsigned char *)srh + sizeof(*srh) +
+			srh_state->hdrlen);
+	ptr = skb->data + offset;
+
+	if (unlikely(ptr < srh_tlvs || ptr > srh_end))
+		return -EFAULT;
+	if (unlikely(len < 0 && (void *)((char *)ptr - len) > srh_end))
+		return -EFAULT;
+
+	if (len > 0) {
+		ret = skb_cow_head(skb, len);
+		if (unlikely(ret < 0))
+			return ret;
+
+		ret = bpf_skb_net_hdr_push(skb, offset, len);
+	} else {
+		ret = bpf_skb_net_hdr_pop(skb, offset, -1 * len);
+	}
+	if (unlikely(ret < 0))
+		return ret;
+
+	hdr = (struct ipv6hdr *)skb->data;
+	hdr->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
+
+	bpf_compute_data_pointers(skb);
+	srh_state->hdrlen += len;
+	srh_state->valid = 0;
+	return 0;
+#else /* CONFIG_IPV6_SEG6_BPF */
+	return -EOPNOTSUPP;
+#endif
+}
+
+static const struct bpf_func_proto bpf_lwt_seg6_adjust_srh_proto = {
+	.func		= bpf_lwt_seg6_adjust_srh,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+	.arg2_type	= ARG_ANYTHING,
+	.arg3_type	= ARG_ANYTHING,
+};
+
+bool bpf_helper_changes_pkt_data(void *func)
+{
+	if (func == bpf_skb_vlan_push ||
+	    func == bpf_skb_vlan_pop ||
+	    func == bpf_skb_store_bytes ||
+	    func == bpf_skb_change_proto ||
+	    func == bpf_skb_change_head ||
+	    func == bpf_skb_change_tail ||
+	    func == bpf_skb_adjust_room ||
+	    func == bpf_skb_pull_data ||
+	    func == bpf_clone_redirect ||
+	    func == bpf_l3_csum_replace ||
+	    func == bpf_l4_csum_replace ||
+	    func == bpf_xdp_adjust_head ||
+	    func == bpf_xdp_adjust_meta ||
+	    func == bpf_msg_pull_data ||
+	    func == bpf_xdp_adjust_tail ||
+	    func == bpf_lwt_push_encap ||
+	    func == bpf_lwt_seg6_store_bytes ||
+	    func == bpf_lwt_seg6_adjust_srh ||
+	    func == bpf_lwt_seg6_action
+	    )
+		return true;
+
+	return false;
+}
+
 static const struct bpf_func_proto *
 bpf_base_func_proto(enum bpf_func_id func_id)
 {
@@ -4703,7 +4940,6 @@ static bool lwt_is_valid_access(int off, int size,
 	return bpf_skb_is_valid_access(off, size, type, prog, info);
 }
 
-
 /* Attach type specific accesses */
 static bool __sock_filter_check_attach_type(int off,
 					    enum bpf_access_type access_type,
diff --git a/net/ipv6/Kconfig b/net/ipv6/Kconfig
index 6794ddf0547c..f0e8a762ae0c 100644
--- a/net/ipv6/Kconfig
+++ b/net/ipv6/Kconfig
@@ -330,4 +330,9 @@ config IPV6_SEG6_HMAC
 
 	  If unsure, say N.
 
+config IPV6_SEG6_BPF
+	def_bool y
+	depends on IPV6_SEG6_LWTUNNEL
+	depends on IPV6 = y
+
 endif # IPV6
diff --git a/net/ipv6/seg6_local.c b/net/ipv6/seg6_local.c
index e9b23fb924ad..ae68c1ef8fb0 100644
--- a/net/ipv6/seg6_local.c
+++ b/net/ipv6/seg6_local.c
@@ -449,6 +449,8 @@ static int input_action_end_b6_encap(struct sk_buff *skb,
 	return err;
 }
 
+DEFINE_PER_CPU(struct seg6_bpf_srh_state, seg6_bpf_srh_states);
+
 static struct seg6_action_desc seg6_action_table[] = {
 	{
 		.action		= SEG6_LOCAL_ACTION_END,
-- 
2.16.1

^ permalink raw reply related

* [PATCH bpf-next v5 2/6] ipv6: sr: export function lookup_nexthop
From: Mathieu Xhonneux @ 2018-05-12 17:25 UTC (permalink / raw)
  To: netdev; +Cc: dlebrun, alexei.starovoitov
In-Reply-To: <cover.1526143526.git.m.xhonneux@gmail.com>

The function lookup_nexthop is essential to implement most of the seg6local
actions. As we want to provide a BPF helper allowing to apply some of these
actions on the packet being processed, the helper should be able to call
this function, hence the need to make it public.

Moreover, if one argument is incorrect or if the next hop can not be found,
an error should be returned by the BPF helper so the BPF program can adapt
its processing of the packet (return an error, properly force the drop,
...). This patch hence makes this function return dst->error to indicate a
possible error.

Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com>
Acked-by: David Lebrun <dlebrun@google.com>
---
 include/net/seg6.h       |  3 ++-
 include/net/seg6_local.h | 24 ++++++++++++++++++++++++
 net/ipv6/seg6_local.c    | 20 +++++++++++---------
 3 files changed, 37 insertions(+), 10 deletions(-)
 create mode 100644 include/net/seg6_local.h

diff --git a/include/net/seg6.h b/include/net/seg6.h
index 70b4cfac52d7..e029e301faa5 100644
--- a/include/net/seg6.h
+++ b/include/net/seg6.h
@@ -67,5 +67,6 @@ extern bool seg6_validate_srh(struct ipv6_sr_hdr *srh, int len);
 extern int seg6_do_srh_encap(struct sk_buff *skb, struct ipv6_sr_hdr *osrh,
 			     int proto);
 extern int seg6_do_srh_inline(struct sk_buff *skb, struct ipv6_sr_hdr *osrh);
-
+extern int seg6_lookup_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr,
+			       u32 tbl_id);
 #endif
diff --git a/include/net/seg6_local.h b/include/net/seg6_local.h
new file mode 100644
index 000000000000..57498b23085d
--- /dev/null
+++ b/include/net/seg6_local.h
@@ -0,0 +1,24 @@
+/*
+ *  SR-IPv6 implementation
+ *
+ *  Authors:
+ *  David Lebrun <david.lebrun@uclouvain.be>
+ *  eBPF support: Mathieu Xhonneux <m.xhonneux@gmail.com>
+ *
+ *
+ *  This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _NET_SEG6_LOCAL_H
+#define _NET_SEG6_LOCAL_H
+
+#include <linux/net.h>
+#include <linux/ipv6.h>
+
+extern int seg6_lookup_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr,
+			       u32 tbl_id);
+
+#endif
diff --git a/net/ipv6/seg6_local.c b/net/ipv6/seg6_local.c
index 45722327375a..e9b23fb924ad 100644
--- a/net/ipv6/seg6_local.c
+++ b/net/ipv6/seg6_local.c
@@ -30,6 +30,7 @@
 #ifdef CONFIG_IPV6_SEG6_HMAC
 #include <net/seg6_hmac.h>
 #endif
+#include <net/seg6_local.h>
 #include <linux/etherdevice.h>
 
 struct seg6_local_lwt;
@@ -140,8 +141,8 @@ static void advance_nextseg(struct ipv6_sr_hdr *srh, struct in6_addr *daddr)
 	*daddr = *addr;
 }
 
-static void lookup_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr,
-			   u32 tbl_id)
+int seg6_lookup_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr,
+			u32 tbl_id)
 {
 	struct net *net = dev_net(skb->dev);
 	struct ipv6hdr *hdr = ipv6_hdr(skb);
@@ -187,6 +188,7 @@ static void lookup_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr,
 
 	skb_dst_drop(skb);
 	skb_dst_set(skb, dst);
+	return dst->error;
 }
 
 /* regular endpoint function */
@@ -200,7 +202,7 @@ static int input_action_end(struct sk_buff *skb, struct seg6_local_lwt *slwt)
 
 	advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
 
-	lookup_nexthop(skb, NULL, 0);
+	seg6_lookup_nexthop(skb, NULL, 0);
 
 	return dst_input(skb);
 
@@ -220,7 +222,7 @@ static int input_action_end_x(struct sk_buff *skb, struct seg6_local_lwt *slwt)
 
 	advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
 
-	lookup_nexthop(skb, &slwt->nh6, 0);
+	seg6_lookup_nexthop(skb, &slwt->nh6, 0);
 
 	return dst_input(skb);
 
@@ -239,7 +241,7 @@ static int input_action_end_t(struct sk_buff *skb, struct seg6_local_lwt *slwt)
 
 	advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
 
-	lookup_nexthop(skb, NULL, slwt->table);
+	seg6_lookup_nexthop(skb, NULL, slwt->table);
 
 	return dst_input(skb);
 
@@ -331,7 +333,7 @@ static int input_action_end_dx6(struct sk_buff *skb,
 	if (!ipv6_addr_any(&slwt->nh6))
 		nhaddr = &slwt->nh6;
 
-	lookup_nexthop(skb, nhaddr, 0);
+	seg6_lookup_nexthop(skb, nhaddr, 0);
 
 	return dst_input(skb);
 drop:
@@ -380,7 +382,7 @@ static int input_action_end_dt6(struct sk_buff *skb,
 	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
 		goto drop;
 
-	lookup_nexthop(skb, NULL, slwt->table);
+	seg6_lookup_nexthop(skb, NULL, slwt->table);
 
 	return dst_input(skb);
 
@@ -406,7 +408,7 @@ static int input_action_end_b6(struct sk_buff *skb, struct seg6_local_lwt *slwt)
 	ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
 	skb_set_transport_header(skb, sizeof(struct ipv6hdr));
 
-	lookup_nexthop(skb, NULL, 0);
+	seg6_lookup_nexthop(skb, NULL, 0);
 
 	return dst_input(skb);
 
@@ -438,7 +440,7 @@ static int input_action_end_b6_encap(struct sk_buff *skb,
 	ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
 	skb_set_transport_header(skb, sizeof(struct ipv6hdr));
 
-	lookup_nexthop(skb, NULL, 0);
+	seg6_lookup_nexthop(skb, NULL, 0);
 
 	return dst_input(skb);
 
-- 
2.16.1

^ permalink raw reply related

* [PATCH bpf-next v5 1/6] ipv6: sr: make seg6.h includable without IPv6
From: Mathieu Xhonneux @ 2018-05-12 17:25 UTC (permalink / raw)
  To: netdev; +Cc: dlebrun, alexei.starovoitov
In-Reply-To: <cover.1526143526.git.m.xhonneux@gmail.com>

include/net/seg6.h cannot be included in a source file if CONFIG_IPV6 is
not enabled:
   include/net/seg6.h: In function 'seg6_pernet':
>> include/net/seg6.h:52:14: error: 'struct net' has no member named
                                        'ipv6'; did you mean 'ipv4'?
     return net->ipv6.seg6_data;
                 ^~~~
                 ipv4

This commit makes seg6_pernet return NULL if IPv6 is not compiled, hence
allowing seg6.h to be included regardless of the configuration.

Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com>
---
 include/net/seg6.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/include/net/seg6.h b/include/net/seg6.h
index 099bad59dc90..70b4cfac52d7 100644
--- a/include/net/seg6.h
+++ b/include/net/seg6.h
@@ -49,7 +49,11 @@ struct seg6_pernet_data {
 
 static inline struct seg6_pernet_data *seg6_pernet(struct net *net)
 {
+#if IS_ENABLED(CONFIG_IPV6)
 	return net->ipv6.seg6_data;
+#else
+	return NULL;
+#endif
 }
 
 extern int seg6_init(void);
-- 
2.16.1

^ permalink raw reply related

* [PATCH bpf-next v5 0/6] ipv6: sr: introduce seg6local End.BPF action
From: Mathieu Xhonneux @ 2018-05-12 17:25 UTC (permalink / raw)
  To: netdev; +Cc: dlebrun, alexei.starovoitov

As of Linux 4.14, it is possible to define advanced local processing for
IPv6 packets with a Segment Routing Header through the seg6local LWT
infrastructure. This LWT implements the network programming principles
defined in the IETF “SRv6 Network Programming” draft.

The implemented operations are generic, and it would be very interesting to
be able to implement user-specific seg6local actions, without having to
modify the kernel directly. To do so, this patchset adds an End.BPF action
to seg6local, powered by some specific Segment Routing-related helpers,
which provide SR functionalities that can be applied on the packet. This
BPF hook would then allow to implement specific actions at native kernel
speed such as OAM features, advanced SR SDN policies, SRv6 actions like
Segment Routing Header (SRH) encapsulation depending on the content of
the packet, etc.

This patchset is divided in 6 patches, whose main features are :

- A new seg6local action End.BPF with the corresponding new BPF program
  type BPF_PROG_TYPE_LWT_SEG6LOCAL. Such attached BPF program can be
  passed to the LWT seg6local through netlink, the same way as the LWT
  BPF hook operates.
- 3 new BPF helpers for the seg6local BPF hook, allowing to edit/grow/
  shrink a SRH and apply on a packet some of the generic SRv6 actions.
- 1 new BPF helper for the LWT BPF IN hook, allowing to add a SRH through
  encapsulation (via IPv6 encapsulation or inlining if the packet contains
  already an IPv6 header).

As this patchset adds a new LWT BPF hook, I took into account the result of
the discussions when the LWT BPF infrastructure got merged. Hence, the
seg6local BPF hook doesn’t allow write access to skb->data directly, only
the SRH can be modified through specific helpers, which ensures that the
integrity of the packet is maintained.
More details are available in the related patches messages.

The performances of this BPF hook have been assessed with the BPF JIT
enabled on a Intel Xeon X3440 processors with 4 cores and 8 threads
clocked at 2.53 GHz. No throughput losses are noted with the seg6local
BPF hook when the BPF program does nothing (440kpps). Adding a 8-bytes
TLV (1 call each to bpf_lwt_seg6_adjust_srh and bpf_lwt_seg6_store_bytes)
drops the throughput to 410kpps, and inlining a SRH via
bpf_lwt_seg6_action drops the throughput to 420kpps.
All throughputs are stable.

-------
v2: move the SRH integrity state from skb->cb to a per-cpu buffer
v3: - document helpers in man-page style
    - fix kbuild bugs
    - un-break BPF LWT out hook
    - bpf_push_seg6_encap is now static
    - preempt_enable is now called when the packet is dropped in
      input_action_end_bpf
v4: fix kbuild bugs when CONFIG_IPV6=m
v5: fix kbuild sparse warnings when CONFIG_IPV6=m

Thanks.


Mathieu Xhonneux (6):
  ipv6: sr: make seg6.h includable without IPv6
  ipv6: sr: export function lookup_nexthop
  bpf: Add IPv6 Segment Routing helpers
  bpf: Split lwt inout verifier structures
  ipv6: sr: Add seg6local action End.BPF
  selftests/bpf: test for seg6local End.BPF action

 include/linux/bpf_types.h                         |   5 +-
 include/net/seg6.h                                |   7 +-
 include/net/seg6_local.h                          |  32 ++
 include/uapi/linux/bpf.h                          |  98 ++++-
 include/uapi/linux/seg6_local.h                   |   3 +
 kernel/bpf/verifier.c                             |   1 +
 net/core/filter.c                                 | 390 ++++++++++++++++---
 net/ipv6/Kconfig                                  |   5 +
 net/ipv6/seg6_local.c                             | 180 ++++++++-
 tools/include/uapi/linux/bpf.h                    |  98 ++++-
 tools/lib/bpf/libbpf.c                            |   1 +
 tools/testing/selftests/bpf/Makefile              |   5 +-
 tools/testing/selftests/bpf/bpf_helpers.h         |  12 +
 tools/testing/selftests/bpf/test_lwt_seg6local.c  | 438 ++++++++++++++++++++++
 tools/testing/selftests/bpf/test_lwt_seg6local.sh | 140 +++++++
 15 files changed, 1340 insertions(+), 75 deletions(-)
 create mode 100644 include/net/seg6_local.h
 create mode 100644 tools/testing/selftests/bpf/test_lwt_seg6local.c
 create mode 100755 tools/testing/selftests/bpf/test_lwt_seg6local.sh

-- 
2.16.1

^ permalink raw reply

* Re: [PATCH net-next] net:sched: add gkprio scheduler
From: Jamal Hadi Salim @ 2018-05-12 14:48 UTC (permalink / raw)
  To: Michel Machado, Cong Wang
  Cc: Nishanth Devarajan, Jiri Pirko, David Miller,
	Linux Kernel Network Developers, Cody Doucette
In-Reply-To: <32b58e4e-c06c-0266-e4d9-caca365e46ef@digirati.com.br>

Sorry for the latency..

On 09/05/18 01:37 PM, Michel Machado wrote:
> On 05/09/2018 10:43 AM, Jamal Hadi Salim wrote:
>> On 08/05/18 10:27 PM, Cong Wang wrote:
>>> On Tue, May 8, 2018 at 6:29 AM, Jamal Hadi Salim <jhs@mojatatu.com> 
>>> wrote:

> 
> I like the suggestion of extending skbmod to mark skbprio based on ds. 
> Given that DSprio would no longer depend on the DS field, would you have 
> a name suggestion for this new queue discipline since the name "prio" is 
> currently in use?
> 

Not sure what to call it.
My struggle is still with the intended end goal of the qdisc.
It looks like prio qdisc except for the enqueue part which attempts
to use a shared global queue size for all prios. I would have
pointed to other approaches which use global priority queue pool
which do early congestion detection like RED or variants like GRED but
those use average values of the queue lengths not instantenous values 
such as you do.
I am tempted to say - based on my current understanding - that you dont
need a new qdisc; rather you need to map your dsfields to skbprio
(via skbmod) and stick with prio qdisc. I also think the skbmod
mapping is useful regardless of this need.

> What should be the range of priorities that this new queue discipline 
> would accept? skb->prioriry is of type __u32, but supporting 2^32 
> priorities would require too large of an array to index packets by 
> priority; the DS field is only 6 bits long. Do you have a use case in 
> mind to guide us here?
>

Look at the priomap or prio2band arrangement on prio qdisc
or pfifo_fast qdisc. You take an skbprio as an index into the array
and retrieve a queue to enqueue to. The size of the array is 16.
In the past this was based IIRC on ip precedence + 1 bit. Those map
similarly to DS fields (calls selectors, assured forwarding etc). So
no need to even increase the array beyond current 16.

>> I find the cleverness in changing the highest/low prios confusing.
>> It looks error-prone (I guess that is why there is a BUG check)
>> To the authors: Is there a document/paper on the theory of this thing
>> as to why no explicit queues are "faster"?
> 
> The priority orientation in GKprio is due to two factors: failing safe 
> and elegance. If zero were the highest priority, any operational mistake 
> that leads not-classified packets through GKprio would potentially 
> disrupt the system. We are humans, we'll make mistakes. The elegance 
> aspect comes from the fact that the assigned priority is not massaged to 
> fit the DS field. We find it helpful while inspecting packets on the wire.
> 
> The reason for us to avoid explicit queues in GKprio, which could change 
> the behavior within a given priority, is to closely abide to the 
> expected behavior assumed to prove Theorem 4.1 in the paper "Portcullis: 
> Protecting Connection Setup from Denial-of-Capability Attacks":
> 
> https://dl.acm.org/citation.cfm?id=1282413
> 

Paper seems to be under paywall. Googling didnt help.
My concern is still the science behind this; if you had written up
some test setup which shows how you concluded this was a better
approach at DOS prevention and showed some numbers it would have
helped greatly clarify.

>> 1) I agree that using multiple queues as in prio qdisc would make it
>> more manageable; does not necessarily need to be classful if you
>> use implicit skbprio classification. i.e on equeue use a priority
>> map to select a queue; on dequeue always dequeu from highest prio
>> until it has no more packets to send.
> 
> In my reply to Cong, I point out that there is a technical limitation in 
> the interface of queue disciplines that forbids GKprio to have explicit 
> sub-queues:
> 
> https://www.mail-archive.com/netdev@vger.kernel.org/msg234201.html
> 
>> 2) Dropping already enqueued packets will not work well for
>> local feedback (__NET_XMIT_BYPASS return code is about the
>> packet that has been dropped from earlier enqueueing because
>> it is lower priority - it does not  signify anything with
>> current skb to which actually just got enqueud).
>> Perhaps (off top of my head) is to always enqueue packets on
>> high priority when their limit is exceeded as long as lower prio has
>> some space. Means youd have to increment low prio accounting if their
>> space is used.
> 
> I don't understand the point you are making here. Could you develop it 
> further?
> 

Sorry - I was meaning NET_XMIT_CN
If you drop an already enqueued packet - it makes sense to signify as
such using NET_XMIT_CN
this does not make sense for forwarded packets but it does
for locally sourced packets.

cheers,
jamal

^ permalink raw reply

* Re: [PATCH net-next 3/8] sctp: move the flush of ctrl chunks into its own function
From: Marcelo Ricardo Leitner @ 2018-05-12 13:29 UTC (permalink / raw)
  To: netdev; +Cc: linux-sctp, Neil Horman, Vlad Yasevich, Xin Long
In-Reply-To: <23e474529812a3e804b1a4311ec48f250b81bbc5.1526077476.git.marcelo.leitner@gmail.com>

On Fri, May 11, 2018 at 08:28:45PM -0300, Marcelo Ricardo Leitner wrote:
> Named sctp_outq_flush_ctrl and, with that, keep the contexts contained.

kbuild bot spotted some issues with this patch. They were corrected
later on on the series, but I should fix them here.

Will post a v2 later today.

^ permalink raw reply

* [PATCH] ipvlan: flush arp table when mac address changed
From: liuqifa @ 2018-05-12 11:00 UTC (permalink / raw)
  To: davem, dsahern, maheshb, weiyongjun1, maowenan, dingtianhong,
	liuqifa
  Cc: netdev, linux-kernel

From: Keefe Liu <liuqifa@huawei.com>

When master device's mac has been changed, the
commit <32c10bbfe914> "ipvlan: always use the current L2
addr of the master" makes the IPVlan devices's mac changed
also, but it doesn't flush the IPVlan's arp table.

Signed-off-by: Keefe Liu <liuqifa@huawei.com>
---
 drivers/net/ipvlan/ipvlan_main.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ipvlan/ipvlan_main.c b/drivers/net/ipvlan/ipvlan_main.c
index 450eec2..a1edfe1 100644
--- a/drivers/net/ipvlan/ipvlan_main.c
+++ b/drivers/net/ipvlan/ipvlan_main.c
@@ -7,6 +7,8 @@
  *
  */
 
+#include <net/neighbour.h>
+#include <net/arp.h>
 #include "ipvlan.h"
 
 static unsigned int ipvlan_netid __read_mostly;
@@ -792,8 +794,10 @@ static int ipvlan_device_event(struct notifier_block *unused,
 		break;
 
 	case NETDEV_CHANGEADDR:
-		list_for_each_entry(ipvlan, &port->ipvlans, pnode)
+		list_for_each_entry(ipvlan, &port->ipvlans, pnode) {
 			ether_addr_copy(ipvlan->dev->dev_addr, dev->dev_addr);
+			neigh_changeaddr(&arp_tbl, ipvlan->dev);
+		}
 		break;
 
 	case NETDEV_PRE_TYPE_CHANGE:
-- 
1.8.3.1

^ permalink raw reply related


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