[PULL 00/13] Net patches

[PULL 00/13] Net patches

[Jason Wang]

The following changes since commit bdee969c0e65d4d509932b1d70e3a3b2ffbff6d5:

  Merge remote-tracking branch 'remotes/bonzini-gitlab/tags/for-upstream' into staging (2021-03-19 18:01:17 +0000)

are available in the git repository at:

  https://github.com/jasowang/qemu.git tags/net-pull-request

for you to fetch changes up to c7274b5ef43614dd133daec1e2018f71d8744088:

  net/eth: Add an assert() and invert if() statement to simplify code (2021-03-22 17:34:31 +0800)

----------------------------------------------------------------

----------------------------------------------------------------
Bin Meng (4):
      net: eth: Add a helper to pad a short Ethernet frame
      net: Add a 'do_not_pad" to NetClientState
      net: Pad short frames to minimum size before sending from SLiRP/TAP
      hw/net: virtio-net: Initialize nc->do_not_pad to true

Lukas Straub (2):
      net/colo-compare.c: Fix memory leak for non-tcp packet
      net/colo-compare.c: Optimize removal of secondary packet

Philippe Mathieu-Daudé (7):
      net/eth: Use correct in6_address offset in _eth_get_rss_ex_dst_addr()
      net/eth: Simplify _eth_get_rss_ex_dst_addr()
      net/eth: Better describe _eth_get_rss_ex_dst_addr's offset argument
      net/eth: Check size earlier in _eth_get_rss_ex_dst_addr()
      net/eth: Check iovec has enough data earlier
      net/eth: Read ip6_ext_hdr_routing buffer before accessing it
      net/eth: Add an assert() and invert if() statement to simplify code

 MAINTAINERS                    |  1 +
 hw/net/virtio-net.c            |  4 +++
 include/net/eth.h              | 17 ++++++++++++
 include/net/net.h              |  1 +
 net/colo-compare.c             |  3 ++-
 net/eth.c                      | 61 +++++++++++++++++++++++++++---------------
 net/slirp.c                    | 10 +++++++
 net/tap-win32.c                | 10 +++++++
 net/tap.c                      | 10 +++++++
 tests/qtest/fuzz-e1000e-test.c | 53 ++++++++++++++++++++++++++++++++++++
 tests/qtest/meson.build        |  1 +
 11 files changed, 148 insertions(+), 23 deletions(-)
 create mode 100644 tests/qtest/fuzz-e1000e-test.c

[PULL 01/13] net: eth: Add a helper to pad a short Ethernet frame

[Jason Wang]

From: Bin Meng <bmeng.cn@gmail.com>

Add a helper to pad a short Ethernet frame to the minimum required
length, which can be used by backends' code.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 include/net/eth.h | 17 +++++++++++++++++
 net/eth.c         | 17 +++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/include/net/eth.h b/include/net/eth.h
index 0671be6..7767ae8 100644
--- a/include/net/eth.h
+++ b/include/net/eth.h
@@ -31,6 +31,7 @@
 
 #define ETH_ALEN 6
 #define ETH_HLEN 14
+#define ETH_ZLEN 60     /* Min. octets in frame without FCS */
 
 struct eth_header {
     uint8_t  h_dest[ETH_ALEN];   /* destination eth addr */
@@ -422,4 +423,20 @@ bool
 eth_parse_ipv6_hdr(const struct iovec *pkt, int pkt_frags,
                    size_t ip6hdr_off, eth_ip6_hdr_info *info);
 
+/**
+ * eth_pad_short_frame - pad a short frame to the minimum Ethernet frame length
+ *
+ * If the Ethernet frame size is shorter than 60 bytes, it will be padded to
+ * 60 bytes at the address @padded_pkt.
+ *
+ * @padded_pkt: buffer address to hold the padded frame
+ * @padded_buflen: pointer holding length of @padded_pkt. If the frame is
+ *                 padded, the length will be updated to the padded one.
+ * @pkt: address to hold the original Ethernet frame
+ * @pkt_size: size of the original Ethernet frame
+ * @return true if the frame is padded, otherwise false
+ */
+bool eth_pad_short_frame(uint8_t *padded_pkt, size_t *padded_buflen,
+                         const void *pkt, size_t pkt_size);
+
 #endif
diff --git a/net/eth.c b/net/eth.c
index 1e0821c..f913e43 100644
--- a/net/eth.c
+++ b/net/eth.c
@@ -548,3 +548,20 @@ bool eth_parse_ipv6_hdr(const struct iovec *pkt, int pkt_frags,
     info->l4proto = ext_hdr.ip6r_nxt;
     return true;
 }
+
+bool eth_pad_short_frame(uint8_t *padded_pkt, size_t *padded_buflen,
+                         const void *pkt, size_t pkt_size)
+{
+    assert(padded_buflen && *padded_buflen >= ETH_ZLEN);
+
+    if (pkt_size >= ETH_ZLEN) {
+        return false;
+    }
+
+    /* pad to minimum Ethernet frame length */
+    memcpy(padded_pkt, pkt, pkt_size);
+    memset(&padded_pkt[pkt_size], 0, ETH_ZLEN - pkt_size);
+    *padded_buflen = ETH_ZLEN;
+
+    return true;
+}
-- 
2.7.4

[PULL 02/13] net: Add a 'do_not_pad" to NetClientState

[Jason Wang]

From: Bin Meng <bmeng.cn@gmail.com>

This adds a flag in NetClientState, so that a net client can tell
its peer that the packets do not need to be padded to the minimum
size of an Ethernet frame (60 bytes) before sending to it.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 include/net/net.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/net/net.h b/include/net/net.h
index a02949f..3559f3c 100644
--- a/include/net/net.h
+++ b/include/net/net.h
@@ -103,6 +103,7 @@ struct NetClientState {
     int vring_enable;
     int vnet_hdr_len;
     bool is_netdev;
+    bool do_not_pad; /* do not pad to the minimum ethernet frame length */
     QTAILQ_HEAD(, NetFilterState) filters;
 };
 
-- 
2.7.4

[PULL 03/13] net: Pad short frames to minimum size before sending from SLiRP/TAP

[Jason Wang]

From: Bin Meng <bmeng.cn@gmail.com>

The minimum Ethernet frame length is 60 bytes. For short frames with
smaller length like ARP packets (only 42 bytes), on a real world NIC
it can choose either padding its length to the minimum required 60
bytes, or sending it out directly to the wire. Such behavior can be
hardcoded or controled by a register bit. Similarly on the receive
path, NICs can choose either dropping such short frames directly or
handing them over to software to handle.

On the other hand, for the network backends like SLiRP/TAP, they
don't expose a way to control the short frame behavior. As of today
they just send/receive data from/to the other end connected to them,
which means any sized packet is acceptable. So they can send and
receive short frames without any problem. It is observed that ARP
packets sent from SLiRP/TAP are 42 bytes, and SLiRP/TAP just send
these ARP packets to the other end which might be a NIC model that
does not allow short frames to pass through.

To provide better compatibility, for packets sent from QEMU network
backends like SLiRP/TAP, we change to pad short frames before sending
it out to the other end, if the other end does not forbid it via the
nc->do_not_pad flag. This ensures a backend as an Ethernet sender
does not violate the spec. But with this change, the behavior of
dropping short frames from SLiRP/TAP interfaces in the NIC model
cannot be emulated because it always receives a packet that is spec
complaint. The capability of sending short frames from NIC models is
still supported and short frames can still pass through SLiRP/TAP.

This commit should be able to fix the issue as reported with some
NIC models before, that ARP requests get dropped, preventing the
guest from becoming visible on the network. It was workarounded in
these NIC models on the receive path, that when a short frame is
received, it is padded up to 60 bytes.

The following 2 commits seem to be the one to workaround this issue
in e1000 and vmxenet3 before, and should probably be reverted.

  commit 78aeb23eded2 ("e1000: Pad short frames to minimum size (60 bytes)")
  commit 40a87c6c9b11 ("vmxnet3: Pad short frames to minimum size (60 bytes)")

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 net/slirp.c     | 10 ++++++++++
 net/tap-win32.c | 10 ++++++++++
 net/tap.c       | 10 ++++++++++
 3 files changed, 30 insertions(+)

diff --git a/net/slirp.c b/net/slirp.c
index 9454a67..a9fdc7a 100644
--- a/net/slirp.c
+++ b/net/slirp.c
@@ -31,6 +31,7 @@
 #include <pwd.h>
 #include <sys/wait.h>
 #endif
+#include "net/eth.h"
 #include "net/net.h"
 #include "clients.h"
 #include "hub.h"
@@ -115,6 +116,15 @@ static ssize_t net_slirp_send_packet(const void *pkt, size_t pkt_len,
                                      void *opaque)
 {
     SlirpState *s = opaque;
+    uint8_t min_pkt[ETH_ZLEN];
+    size_t min_pktsz = sizeof(min_pkt);
+
+    if (!s->nc.peer->do_not_pad) {
+        if (eth_pad_short_frame(min_pkt, &min_pktsz, pkt, pkt_len)) {
+            pkt = min_pkt;
+            pkt_len = min_pktsz;
+        }
+    }
 
     return qemu_send_packet(&s->nc, pkt, pkt_len);
 }
diff --git a/net/tap-win32.c b/net/tap-win32.c
index 21e4511..d7c2a87 100644
--- a/net/tap-win32.c
+++ b/net/tap-win32.c
@@ -31,6 +31,7 @@
 
 #include "qemu-common.h"
 #include "clients.h"            /* net_init_tap */
+#include "net/eth.h"
 #include "net/net.h"
 #include "net/tap.h"            /* tap_has_ufo, ... */
 #include "qemu/error-report.h"
@@ -688,9 +689,18 @@ static void tap_win32_send(void *opaque)
     uint8_t *buf;
     int max_size = 4096;
     int size;
+    uint8_t min_pkt[ETH_ZLEN];
+    size_t min_pktsz = sizeof(min_pkt);
 
     size = tap_win32_read(s->handle, &buf, max_size);
     if (size > 0) {
+        if (!s->nc.peer->do_not_pad) {
+            if (eth_pad_short_frame(min_pkt, &min_pktsz, buf, size)) {
+                buf = min_pkt;
+                size = min_pktsz;
+            }
+        }
+
         qemu_send_packet(&s->nc, buf, size);
         tap_win32_free_buffer(s->handle, buf);
     }
diff --git a/net/tap.c b/net/tap.c
index 12a08d5..d6d8456 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -32,6 +32,7 @@
 #include <sys/socket.h>
 #include <net/if.h>
 
+#include "net/eth.h"
 #include "net/net.h"
 #include "clients.h"
 #include "monitor/monitor.h"
@@ -189,6 +190,8 @@ static void tap_send(void *opaque)
 
     while (true) {
         uint8_t *buf = s->buf;
+        uint8_t min_pkt[ETH_ZLEN];
+        size_t min_pktsz = sizeof(min_pkt);
 
         size = tap_read_packet(s->fd, s->buf, sizeof(s->buf));
         if (size <= 0) {
@@ -200,6 +203,13 @@ static void tap_send(void *opaque)
             size -= s->host_vnet_hdr_len;
         }
 
+        if (!s->nc.peer->do_not_pad) {
+            if (eth_pad_short_frame(min_pkt, &min_pktsz, buf, size)) {
+                buf = min_pkt;
+                size = min_pktsz;
+            }
+        }
+
         size = qemu_send_packet_async(&s->nc, buf, size, tap_send_completed);
         if (size == 0) {
             tap_read_poll(s, false);
-- 
2.7.4

[PULL 04/13] hw/net: virtio-net: Initialize nc->do_not_pad to true

[Jason Wang]

From: Bin Meng <bmeng.cn@gmail.com>

For virtio-net, there is no need to pad the Ethernet frame size to
60 bytes before sending to it.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 hw/net/virtio-net.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 96a3cc8..66b9ff4 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -3314,6 +3314,10 @@ static void virtio_net_device_realize(DeviceState *dev, Error **errp)
                               object_get_typename(OBJECT(dev)), dev->id, n);
     }
 
+    for (i = 0; i < n->max_queues; i++) {
+        n->nic->ncs[i].do_not_pad = true;
+    }
+
     peer_test_vnet_hdr(n);
     if (peer_has_vnet_hdr(n)) {
         for (i = 0; i < n->max_queues; i++) {
-- 
2.7.4

[PULL 05/13] net/colo-compare.c: Fix memory leak for non-tcp packet

[Jason Wang]

From: Lukas Straub <lukasstraub2@web.de>

Additional to removing the packet from the secondary queue,
we also need to free it.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
Signed-off-by: Zhang Chen <chen.zhang@intel.com>
Reviewed-by: Zhang Chen <chen.zhang@intel.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 net/colo-compare.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/colo-compare.c b/net/colo-compare.c
index 84db497..2e819ff 100644
--- a/net/colo-compare.c
+++ b/net/colo-compare.c
@@ -690,6 +690,7 @@ static void colo_compare_packet(CompareState *s, Connection *conn,
 
         if (result) {
             colo_release_primary_pkt(s, pkt);
+            packet_destroy(result->data, NULL);
             g_queue_remove(&conn->secondary_list, result->data);
         } else {
             /*
-- 
2.7.4

[PULL 06/13] net/colo-compare.c: Optimize removal of secondary packet

[Jason Wang]

From: Lukas Straub <lukasstraub2@web.de>

g_queue_remove needs to look up the list entry first, but we
already have it as result and can remove it directly with
g_queue_delete_link.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
Signed-off-by: Zhang Chen <chen.zhang@intel.com>
Reviewed-by: Zhang Chen <chen.zhang@intel.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 net/colo-compare.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/colo-compare.c b/net/colo-compare.c
index 2e819ff..9d1ad99 100644
--- a/net/colo-compare.c
+++ b/net/colo-compare.c
@@ -691,7 +691,7 @@ static void colo_compare_packet(CompareState *s, Connection *conn,
         if (result) {
             colo_release_primary_pkt(s, pkt);
             packet_destroy(result->data, NULL);
-            g_queue_remove(&conn->secondary_list, result->data);
+            g_queue_delete_link(&conn->secondary_list, result);
         } else {
             /*
              * If one packet arrive late, the secondary_list or
-- 
2.7.4

[PULL 07/13] net/eth: Use correct in6_address offset in _eth_get_rss_ex_dst_addr()

[Jason Wang]

From: Philippe Mathieu-Daudé <philmd@redhat.com>

The in6_address comes after the ip6_ext_hdr_routing header,
not after the ip6_ext_hdr one. Fix the offset.

Cc: qemu-stable@nongnu.org
Reported-by: Stefano Garzarella <sgarzare@redhat.com>
Fixes: eb700029c78 ("net_pkt: Extend packet abstraction as required by e1000e functionality")
Reviewed-by: Miroslav Rezanina <mrezanin@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 net/eth.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/eth.c b/net/eth.c
index f913e43..c8babfa 100644
--- a/net/eth.c
+++ b/net/eth.c
@@ -419,7 +419,7 @@ _eth_get_rss_ex_dst_addr(const struct iovec *pkt, int pkt_frags,
         }
 
         bytes_read = iov_to_buf(pkt, pkt_frags,
-                                rthdr_offset + sizeof(*ext_hdr),
+                                rthdr_offset + sizeof(*rthdr),
                                 dst_addr, sizeof(*dst_addr));
 
         return bytes_read == sizeof(*dst_addr);
-- 
2.7.4

[PULL 08/13] net/eth: Simplify _eth_get_rss_ex_dst_addr()

[Jason Wang]

From: Philippe Mathieu-Daudé <philmd@redhat.com>

The length field is already contained in the ip6_ext_hdr structure.
Check it direcly in eth_parse_ipv6_hdr() before calling
_eth_get_rss_ex_dst_addr(), which gets a bit simplified.

Reviewed-by: Miroslav Rezanina <mrezanin@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 net/eth.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/net/eth.c b/net/eth.c
index c8babfa..06badd1 100644
--- a/net/eth.c
+++ b/net/eth.c
@@ -407,9 +407,7 @@ _eth_get_rss_ex_dst_addr(const struct iovec *pkt, int pkt_frags,
 {
     struct ip6_ext_hdr_routing *rthdr = (struct ip6_ext_hdr_routing *) ext_hdr;
 
-    if ((rthdr->rtype == 2) &&
-        (rthdr->len == sizeof(struct in6_address) / 8) &&
-        (rthdr->segleft == 1)) {
+    if ((rthdr->rtype == 2) && (rthdr->segleft == 1)) {
 
         size_t input_size = iov_size(pkt, pkt_frags);
         size_t bytes_read;
@@ -528,10 +526,12 @@ bool eth_parse_ipv6_hdr(const struct iovec *pkt, int pkt_frags,
         }
 
         if (curr_ext_hdr_type == IP6_ROUTING) {
-            info->rss_ex_dst_valid =
-                _eth_get_rss_ex_dst_addr(pkt, pkt_frags,
-                                         ip6hdr_off + info->full_hdr_len,
-                                         &ext_hdr, &info->rss_ex_dst);
+            if (ext_hdr.ip6r_len == sizeof(struct in6_address) / 8) {
+                info->rss_ex_dst_valid =
+                    _eth_get_rss_ex_dst_addr(pkt, pkt_frags,
+                                             ip6hdr_off + info->full_hdr_len,
+                                             &ext_hdr, &info->rss_ex_dst);
+            }
         } else if (curr_ext_hdr_type == IP6_DESTINATON) {
             info->rss_ex_src_valid =
                 _eth_get_rss_ex_src_addr(pkt, pkt_frags,
-- 
2.7.4

[PULL 09/13] net/eth: Better describe _eth_get_rss_ex_dst_addr's offset argument

[Jason Wang]

From: Philippe Mathieu-Daudé <philmd@redhat.com>

The 'offset' argument represents the offset to the ip6_ext_hdr
header, rename it as 'ext_hdr_offset'.

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Miroslav Rezanina <mrezanin@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 net/eth.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/eth.c b/net/eth.c
index 06badd1..5eb05bd 100644
--- a/net/eth.c
+++ b/net/eth.c
@@ -401,7 +401,7 @@ eth_is_ip6_extension_header_type(uint8_t hdr_type)
 
 static bool
 _eth_get_rss_ex_dst_addr(const struct iovec *pkt, int pkt_frags,
-                        size_t rthdr_offset,
+                        size_t ext_hdr_offset,
                         struct ip6_ext_hdr *ext_hdr,
                         struct in6_address *dst_addr)
 {
@@ -412,12 +412,12 @@ _eth_get_rss_ex_dst_addr(const struct iovec *pkt, int pkt_frags,
         size_t input_size = iov_size(pkt, pkt_frags);
         size_t bytes_read;
 
-        if (input_size < rthdr_offset + sizeof(*ext_hdr)) {
+        if (input_size < ext_hdr_offset + sizeof(*ext_hdr)) {
             return false;
         }
 
         bytes_read = iov_to_buf(pkt, pkt_frags,
-                                rthdr_offset + sizeof(*rthdr),
+                                ext_hdr_offset + sizeof(*rthdr),
                                 dst_addr, sizeof(*dst_addr));
 
         return bytes_read == sizeof(*dst_addr);
-- 
2.7.4

[PULL 10/13] net/eth: Check size earlier in _eth_get_rss_ex_dst_addr()

[Jason Wang]

From: Philippe Mathieu-Daudé <philmd@redhat.com>

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Miroslav Rezanina <mrezanin@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 net/eth.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/net/eth.c b/net/eth.c
index 5eb05bd..087aa71 100644
--- a/net/eth.c
+++ b/net/eth.c
@@ -406,16 +406,14 @@ _eth_get_rss_ex_dst_addr(const struct iovec *pkt, int pkt_frags,
                         struct in6_address *dst_addr)
 {
     struct ip6_ext_hdr_routing *rthdr = (struct ip6_ext_hdr_routing *) ext_hdr;
+    size_t input_size = iov_size(pkt, pkt_frags);
+    size_t bytes_read;
 
-    if ((rthdr->rtype == 2) && (rthdr->segleft == 1)) {
-
-        size_t input_size = iov_size(pkt, pkt_frags);
-        size_t bytes_read;
-
-        if (input_size < ext_hdr_offset + sizeof(*ext_hdr)) {
-            return false;
-        }
+    if (input_size < ext_hdr_offset + sizeof(*ext_hdr)) {
+        return false;
+    }
 
+    if ((rthdr->rtype == 2) && (rthdr->segleft == 1)) {
         bytes_read = iov_to_buf(pkt, pkt_frags,
                                 ext_hdr_offset + sizeof(*rthdr),
                                 dst_addr, sizeof(*dst_addr));
-- 
2.7.4

[PULL 11/13] net/eth: Check iovec has enough data earlier

[Jason Wang]

From: Philippe Mathieu-Daudé <philmd@redhat.com>

We want to check fields from ip6_ext_hdr_routing structure
and if correct read the full in6_address. Let's directly check
if our iovec contains enough data for everything, else return
early.

Suggested-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Miroslav Rezanina <mrezanin@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 net/eth.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/eth.c b/net/eth.c
index 087aa71..6db943d 100644
--- a/net/eth.c
+++ b/net/eth.c
@@ -409,7 +409,7 @@ _eth_get_rss_ex_dst_addr(const struct iovec *pkt, int pkt_frags,
     size_t input_size = iov_size(pkt, pkt_frags);
     size_t bytes_read;
 
-    if (input_size < ext_hdr_offset + sizeof(*ext_hdr)) {
+    if (input_size < ext_hdr_offset + sizeof(*rthdr) + sizeof(*dst_addr)) {
         return false;
     }
 
-- 
2.7.4

[PULL 12/13] net/eth: Read ip6_ext_hdr_routing buffer before accessing it

[Jason Wang]

From: Philippe Mathieu-Daudé <philmd@redhat.com>

We can't know the caller read enough data in the memory pointed
by ext_hdr to cast it as a ip6_ext_hdr_routing.
Declare rt_hdr on the stack and fill it again from the iovec.

Since we already checked there is enough data in the iovec buffer,
simply add an assert() call to consume the bytes_read variable.

This fix a 2 bytes buffer overrun in eth_parse_ipv6_hdr() reported
by QEMU fuzzer:

  $ cat << EOF | ./qemu-system-i386 -M pc-q35-5.0 \
    -accel qtest -monitor none \
    -serial none -nographic -qtest stdio
  outl 0xcf8 0x80001010
  outl 0xcfc 0xe1020000
  outl 0xcf8 0x80001004
  outw 0xcfc 0x7
  write 0x25 0x1 0x86
  write 0x26 0x1 0xdd
  write 0x4f 0x1 0x2b
  write 0xe1020030 0x4 0x190002e1
  write 0xe102003a 0x2 0x0807
  write 0xe1020048 0x4 0x12077cdd
  write 0xe1020400 0x4 0xba077cdd
  write 0xe1020420 0x4 0x190002e1
  write 0xe1020428 0x4 0x3509d807
  write 0xe1020438 0x1 0xe2
  EOF
  =================================================================
  ==2859770==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7ffdef904902 at pc 0x561ceefa78de bp 0x7ffdef904820 sp 0x7ffdef904818
  READ of size 1 at 0x7ffdef904902 thread T0
      #0 0x561ceefa78dd in _eth_get_rss_ex_dst_addr net/eth.c:410:17
      #1 0x561ceefa41fb in eth_parse_ipv6_hdr net/eth.c:532:17
      #2 0x561cef7de639 in net_tx_pkt_parse_headers hw/net/net_tx_pkt.c:228:14
      #3 0x561cef7dbef4 in net_tx_pkt_parse hw/net/net_tx_pkt.c:273:9
      #4 0x561ceec29f22 in e1000e_process_tx_desc hw/net/e1000e_core.c:730:29
      #5 0x561ceec28eac in e1000e_start_xmit hw/net/e1000e_core.c:927:9
      #6 0x561ceec1baab in e1000e_set_tdt hw/net/e1000e_core.c:2444:9
      #7 0x561ceebf300e in e1000e_core_write hw/net/e1000e_core.c:3256:9
      #8 0x561cef3cd4cd in e1000e_mmio_write hw/net/e1000e.c:110:5

  Address 0x7ffdef904902 is located in stack of thread T0 at offset 34 in frame
      #0 0x561ceefa320f in eth_parse_ipv6_hdr net/eth.c:486

    This frame has 1 object(s):
      [32, 34) 'ext_hdr' (line 487) <== Memory access at offset 34 overflows this variable
  HINT: this may be a false positive if your program uses some custom stack unwind mechanism, swapcontext or vfork
        (longjmp and C++ exceptions *are* supported)
  SUMMARY: AddressSanitizer: stack-buffer-overflow net/eth.c:410:17 in _eth_get_rss_ex_dst_addr
  Shadow bytes around the buggy address:
    0x10003df188d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x10003df188e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x10003df188f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x10003df18900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x10003df18910: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1
  =>0x10003df18920:[02]f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00
    0x10003df18930: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x10003df18940: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x10003df18950: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x10003df18960: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
    0x10003df18970: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  Shadow byte legend (one shadow byte represents 8 application bytes):
    Addressable:           00
    Partially addressable: 01 02 03 04 05 06 07
    Stack left redzone:      f1
    Stack right redzone:     f3
  ==2859770==ABORTING

Add the corresponding qtest case with the fuzzer reproducer.

FWIW GCC 11 similarly reported:

  net/eth.c: In function 'eth_parse_ipv6_hdr':
  net/eth.c:410:15: error: array subscript 'struct ip6_ext_hdr_routing[0]' is partly outside array bounds of 'struct ip6_ext_hdr[1]' [-Werror=array-bounds]
    410 |     if ((rthdr->rtype == 2) && (rthdr->segleft == 1)) {
        |          ~~~~~^~~~~~~
  net/eth.c:485:24: note: while referencing 'ext_hdr'
    485 |     struct ip6_ext_hdr ext_hdr;
        |                        ^~~~~~~
  net/eth.c:410:38: error: array subscript 'struct ip6_ext_hdr_routing[0]' is partly outside array bounds of 'struct ip6_ext_hdr[1]' [-Werror=array-bounds]
    410 |     if ((rthdr->rtype == 2) && (rthdr->segleft == 1)) {
        |                                 ~~~~~^~~~~~~~~
  net/eth.c:485:24: note: while referencing 'ext_hdr'
    485 |     struct ip6_ext_hdr ext_hdr;
        |                        ^~~~~~~

Cc: qemu-stable@nongnu.org
Buglink: https://bugs.launchpad.net/qemu/+bug/1879531
Reported-by: Alexander Bulekov <alxndr@bu.edu>
Reported-by: Miroslav Rezanina <mrezanin@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Miroslav Rezanina <mrezanin@redhat.com>
Fixes: eb700029c78 ("net_pkt: Extend packet abstraction as required by e1000e functionality")
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 MAINTAINERS                    |  1 +
 net/eth.c                      | 13 +++++++----
 tests/qtest/fuzz-e1000e-test.c | 53 ++++++++++++++++++++++++++++++++++++++++++
 tests/qtest/meson.build        |  1 +
 4 files changed, 63 insertions(+), 5 deletions(-)
 create mode 100644 tests/qtest/fuzz-e1000e-test.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 25fc49d..9147e9a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2027,6 +2027,7 @@ e1000e
 M: Dmitry Fleytman <dmitry.fleytman@gmail.com>
 S: Maintained
 F: hw/net/e1000e*
+F: tests/qtest/fuzz-e1000e-test.c
 
 eepro100
 M: Stefan Weil <sw@weilnetz.de>
diff --git a/net/eth.c b/net/eth.c
index 6db943d..b2704fb 100644
--- a/net/eth.c
+++ b/net/eth.c
@@ -405,17 +405,20 @@ _eth_get_rss_ex_dst_addr(const struct iovec *pkt, int pkt_frags,
                         struct ip6_ext_hdr *ext_hdr,
                         struct in6_address *dst_addr)
 {
-    struct ip6_ext_hdr_routing *rthdr = (struct ip6_ext_hdr_routing *) ext_hdr;
+    struct ip6_ext_hdr_routing rt_hdr;
     size_t input_size = iov_size(pkt, pkt_frags);
     size_t bytes_read;
 
-    if (input_size < ext_hdr_offset + sizeof(*rthdr) + sizeof(*dst_addr)) {
+    if (input_size < ext_hdr_offset + sizeof(rt_hdr) + sizeof(*dst_addr)) {
         return false;
     }
 
-    if ((rthdr->rtype == 2) && (rthdr->segleft == 1)) {
-        bytes_read = iov_to_buf(pkt, pkt_frags,
-                                ext_hdr_offset + sizeof(*rthdr),
+    bytes_read = iov_to_buf(pkt, pkt_frags, ext_hdr_offset,
+                            &rt_hdr, sizeof(rt_hdr));
+    assert(bytes_read == sizeof(rt_hdr));
+
+    if ((rt_hdr.rtype == 2) && (rt_hdr.segleft == 1)) {
+        bytes_read = iov_to_buf(pkt, pkt_frags, ext_hdr_offset + sizeof(rt_hdr),
                                 dst_addr, sizeof(*dst_addr));
 
         return bytes_read == sizeof(*dst_addr);
diff --git a/tests/qtest/fuzz-e1000e-test.c b/tests/qtest/fuzz-e1000e-test.c
new file mode 100644
index 0000000..66229e6
--- /dev/null
+++ b/tests/qtest/fuzz-e1000e-test.c
@@ -0,0 +1,53 @@
+/*
+ * QTest testcase for e1000e device generated by fuzzer
+ *
+ * Copyright (c) 2021 Red Hat, Inc.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+
+#include "libqos/libqtest.h"
+
+/*
+ * https://bugs.launchpad.net/qemu/+bug/1879531
+ */
+static void test_lp1879531_eth_get_rss_ex_dst_addr(void)
+{
+    QTestState *s;
+
+    s = qtest_init("-nographic -monitor none -serial none -M pc-q35-5.0");
+
+    qtest_outl(s, 0xcf8, 0x80001010);
+    qtest_outl(s, 0xcfc, 0xe1020000);
+    qtest_outl(s, 0xcf8, 0x80001004);
+    qtest_outw(s, 0xcfc, 0x7);
+    qtest_writeb(s, 0x25, 0x86);
+    qtest_writeb(s, 0x26, 0xdd);
+    qtest_writeb(s, 0x4f, 0x2b);
+
+    qtest_writel(s, 0xe1020030, 0x190002e1);
+    qtest_writew(s, 0xe102003a, 0x0807);
+    qtest_writel(s, 0xe1020048, 0x12077cdd);
+    qtest_writel(s, 0xe1020400, 0xba077cdd);
+    qtest_writel(s, 0xe1020420, 0x190002e1);
+    qtest_writel(s, 0xe1020428, 0x3509d807);
+    qtest_writeb(s, 0xe1020438, 0xe2);
+    qtest_writeb(s, 0x4f, 0x2b);
+    qtest_quit(s);
+}
+
+int main(int argc, char **argv)
+{
+    const char *arch = qtest_get_arch();
+
+    g_test_init(&argc, &argv, NULL);
+
+    if (strcmp(arch, "i386") == 0 || strcmp(arch, "x86_64") == 0) {
+        qtest_add_func("fuzz/test_lp1879531_eth_get_rss_ex_dst_addr",
+                       test_lp1879531_eth_get_rss_ex_dst_addr);
+    }
+
+    return g_test_run();
+}
diff --git a/tests/qtest/meson.build b/tests/qtest/meson.build
index 9731606..902cfef 100644
--- a/tests/qtest/meson.build
+++ b/tests/qtest/meson.build
@@ -67,6 +67,7 @@ qtests_i386 = \
   (config_all_devices.has_key('CONFIG_TPM_TIS_ISA') ? ['tpm-tis-test'] : []) +              \
   (config_all_devices.has_key('CONFIG_TPM_TIS_ISA') ? ['tpm-tis-swtpm-test'] : []) +        \
   (config_all_devices.has_key('CONFIG_RTL8139_PCI') ? ['rtl8139-test'] : []) +              \
+  (config_all_devices.has_key('CONFIG_E1000E_PCI_EXPRESS') ? ['fuzz-e1000e-test'] : []) +   \
   qtests_pci +                                                                              \
   ['fdc-test',
    'ide-test',
-- 
2.7.4

[PULL 13/13] net/eth: Add an assert() and invert if() statement to simplify code

[Jason Wang]

From: Philippe Mathieu-Daudé <philmd@redhat.com>

To simplify the function body, invert the if() statement, returning
earlier.
Since we already checked there is enough data in the iovec buffer,
simply add an assert() call to consume the bytes_read variable.

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Miroslav Rezanina <mrezanin@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 net/eth.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/net/eth.c b/net/eth.c
index b2704fb..fe876d1 100644
--- a/net/eth.c
+++ b/net/eth.c
@@ -416,15 +416,14 @@ _eth_get_rss_ex_dst_addr(const struct iovec *pkt, int pkt_frags,
     bytes_read = iov_to_buf(pkt, pkt_frags, ext_hdr_offset,
                             &rt_hdr, sizeof(rt_hdr));
     assert(bytes_read == sizeof(rt_hdr));
-
-    if ((rt_hdr.rtype == 2) && (rt_hdr.segleft == 1)) {
-        bytes_read = iov_to_buf(pkt, pkt_frags, ext_hdr_offset + sizeof(rt_hdr),
-                                dst_addr, sizeof(*dst_addr));
-
-        return bytes_read == sizeof(*dst_addr);
+    if ((rt_hdr.rtype != 2) || (rt_hdr.segleft != 1)) {
+        return false;
     }
+    bytes_read = iov_to_buf(pkt, pkt_frags, ext_hdr_offset + sizeof(rt_hdr),
+                            dst_addr, sizeof(*dst_addr));
+    assert(bytes_read == sizeof(*dst_addr));
 
-    return false;
+    return true;
 }
 
 static bool
-- 
2.7.4

Re: [PULL 00/13] Net patches

[Peter Maydell]

On Mon, 22 Mar 2021 at 10:08, Jason Wang <jasowang@redhat.com> wrote:
>
> The following changes since commit bdee969c0e65d4d509932b1d70e3a3b2ffbff6d5:
>
>   Merge remote-tracking branch 'remotes/bonzini-gitlab/tags/for-upstream' into staging (2021-03-19 18:01:17 +0000)
>
> are available in the git repository at:
>
>   https://github.com/jasowang/qemu.git tags/net-pull-request
>
> for you to fetch changes up to c7274b5ef43614dd133daec1e2018f71d8744088:
>
>   net/eth: Add an assert() and invert if() statement to simplify code (2021-03-22 17:34:31 +0800)
>
> ----------------------------------------------------------------
>


Applied, thanks.

Please update the changelog at https://wiki.qemu.org/ChangeLog/6.0
for any user-visible changes.

-- PMM