[PATCH net-next v5 0/3] ioam6: netlink multicast event

[PATCH net-next v5 0/3] ioam6: netlink multicast event

[Justin Iurman]

v5:
 - remove the "must be the destination" check before sending an ioam6
   event
v4:
 - rebase on top of net merge
v3:
 - patchset was mistakenly superseded due to same cover title used for
   iproute2-next equivalent patch -> resend (renamed)
v2:
 - fix warnings

Add generic netlink multicast event support to ioam6 as another solution
to share IOAM data with user space. The other one being via IPv6 raw
sockets combined with ancillary data (or packet socket, if the listener
does not need the processing of the IOAM Option-Type, since the hook is
before in that case). This patchset focuses on the IOAM Pre-allocated
Trace (the only Option-Type currently supported in the kernel), and so
on IOAM "trace" events. See an example of a consumer here [1].

  [1] https://github.com/Advanced-Observability/ioam-agent-python/blob/netlink_event/ioam-agent.py

Justin Iurman (3):
  uapi: ioam6: API for netlink multicast events
  net: ioam6: multicast event
  net: exthdrs: ioam6: send trace event

 include/net/ioam6.h             |  4 +++
 include/uapi/linux/ioam6_genl.h | 20 +++++++++++
 net/ipv6/exthdrs.c              |  4 +++
 net/ipv6/ioam6.c                | 64 +++++++++++++++++++++++++++++++++
 4 files changed, 92 insertions(+)


base-commit: 5fc3903c46a743781cd35fdecfdd889c522e2c3b
-- 
2.34.1

[PATCH net-next v5 1/3] uapi: ioam6: API for netlink multicast events

[Justin Iurman]

Add new api to support ioam6 events for generic netlink multicast. A
first "trace" event is added to the list of ioam6 events, which will
represent an IOAM Pre-allocated Trace Option-Type. It provides another
solution to share IOAM data with user space.

Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Justin Iurman <justin.iurman@uliege.be>
---
 include/uapi/linux/ioam6_genl.h | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/include/uapi/linux/ioam6_genl.h b/include/uapi/linux/ioam6_genl.h
index ca4b22833754..1733fbc51fb5 100644
--- a/include/uapi/linux/ioam6_genl.h
+++ b/include/uapi/linux/ioam6_genl.h
@@ -49,4 +49,24 @@ enum {
 
 #define IOAM6_CMD_MAX (__IOAM6_CMD_MAX - 1)
 
+#define IOAM6_GENL_EV_GRP_NAME "ioam6_events"
+
+enum ioam6_event_type {
+	IOAM6_EVENT_UNSPEC,
+	IOAM6_EVENT_TRACE,
+};
+
+enum ioam6_event_attr {
+	IOAM6_EVENT_ATTR_UNSPEC,
+
+	IOAM6_EVENT_ATTR_TRACE_NAMESPACE,	/* u16 */
+	IOAM6_EVENT_ATTR_TRACE_NODELEN,		/* u8 */
+	IOAM6_EVENT_ATTR_TRACE_TYPE,		/* u32 */
+	IOAM6_EVENT_ATTR_TRACE_DATA,		/* Binary */
+
+	__IOAM6_EVENT_ATTR_MAX
+};
+
+#define IOAM6_EVENT_ATTR_MAX (__IOAM6_EVENT_ATTR_MAX - 1)
+
 #endif /* _UAPI_LINUX_IOAM6_GENL_H */
-- 
2.34.1

[PATCH net-next v5 2/3] net: ioam6: multicast event

[Justin Iurman]

Add a multicast group to the ioam6 generic netlink family and provide
ioam6_event() to send an ioam6 event to the multicast group.

Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Justin Iurman <justin.iurman@uliege.be>
---
 include/net/ioam6.h |  4 +++
 net/ipv6/ioam6.c    | 64 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 68 insertions(+)

diff --git a/include/net/ioam6.h b/include/net/ioam6.h
index 781d2d8b2f29..2cbbee6e806a 100644
--- a/include/net/ioam6.h
+++ b/include/net/ioam6.h
@@ -12,6 +12,7 @@
 #include <linux/net.h>
 #include <linux/ipv6.h>
 #include <linux/ioam6.h>
+#include <linux/ioam6_genl.h>
 #include <linux/rhashtable-types.h>
 
 struct ioam6_namespace {
@@ -65,4 +66,7 @@ void ioam6_exit(void);
 int ioam6_iptunnel_init(void);
 void ioam6_iptunnel_exit(void);
 
+void ioam6_event(enum ioam6_event_type type, struct net *net, gfp_t gfp,
+		 void *opt, unsigned int opt_len);
+
 #endif /* _NET_IOAM6_H */
diff --git a/net/ipv6/ioam6.c b/net/ipv6/ioam6.c
index 571f0e4d9cf3..5fa923f06632 100644
--- a/net/ipv6/ioam6.c
+++ b/net/ipv6/ioam6.c
@@ -612,6 +612,68 @@ static const struct genl_ops ioam6_genl_ops[] = {
 	},
 };
 
+#define IOAM6_GENL_EV_GRP_OFFSET 0
+
+static const struct genl_multicast_group ioam6_mcgrps[] = {
+	[IOAM6_GENL_EV_GRP_OFFSET] = { .name = IOAM6_GENL_EV_GRP_NAME,
+				       .flags = GENL_MCAST_CAP_NET_ADMIN },
+};
+
+static int ioam6_event_put_trace(struct sk_buff *skb,
+				 struct ioam6_trace_hdr *trace,
+				 unsigned int len)
+{
+	if (nla_put_u16(skb, IOAM6_EVENT_ATTR_TRACE_NAMESPACE,
+			be16_to_cpu(trace->namespace_id)) ||
+	    nla_put_u8(skb, IOAM6_EVENT_ATTR_TRACE_NODELEN, trace->nodelen) ||
+	    nla_put_u32(skb, IOAM6_EVENT_ATTR_TRACE_TYPE,
+			be32_to_cpu(trace->type_be32)) ||
+	    nla_put(skb, IOAM6_EVENT_ATTR_TRACE_DATA,
+		    len - sizeof(struct ioam6_trace_hdr) - trace->remlen * 4,
+		    trace->data + trace->remlen * 4))
+		return 1;
+
+	return 0;
+}
+
+void ioam6_event(enum ioam6_event_type type, struct net *net, gfp_t gfp,
+		 void *opt, unsigned int opt_len)
+{
+	struct nlmsghdr *nlh;
+	struct sk_buff *skb;
+
+	if (!genl_has_listeners(&ioam6_genl_family, net,
+				IOAM6_GENL_EV_GRP_OFFSET))
+		return;
+
+	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, gfp);
+	if (!skb)
+		return;
+
+	nlh = genlmsg_put(skb, 0, 0, &ioam6_genl_family, 0, type);
+	if (!nlh)
+		goto nla_put_failure;
+
+	switch (type) {
+	case IOAM6_EVENT_UNSPEC:
+		WARN_ON_ONCE(1);
+		break;
+	case IOAM6_EVENT_TRACE:
+		if (ioam6_event_put_trace(skb, (struct ioam6_trace_hdr *)opt,
+					  opt_len))
+			goto nla_put_failure;
+		break;
+	}
+
+	genlmsg_end(skb, nlh);
+	genlmsg_multicast_netns(&ioam6_genl_family, net, skb, 0,
+				IOAM6_GENL_EV_GRP_OFFSET, gfp);
+	return;
+
+nla_put_failure:
+	nlmsg_free(skb);
+}
+
 static struct genl_family ioam6_genl_family __ro_after_init = {
 	.name		= IOAM6_GENL_NAME,
 	.version	= IOAM6_GENL_VERSION,
@@ -620,6 +682,8 @@ static struct genl_family ioam6_genl_family __ro_after_init = {
 	.ops		= ioam6_genl_ops,
 	.n_ops		= ARRAY_SIZE(ioam6_genl_ops),
 	.resv_start_op	= IOAM6_CMD_NS_SET_SCHEMA + 1,
+	.mcgrps		= ioam6_mcgrps,
+	.n_mcgrps	= ARRAY_SIZE(ioam6_mcgrps),
 	.module		= THIS_MODULE,
 };
 
-- 
2.34.1

[PATCH net-next v5 3/3] net: exthdrs: ioam6: send trace event

[Justin Iurman]

If we're processing an IOAM Pre-allocated Trace Option-Type (the only
one supported currently), then send the trace as an ioam6 event to the
netlink multicast group. This way, user space apps will be able to
collect IOAM data.

Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Justin Iurman <justin.iurman@uliege.be>
---
 net/ipv6/exthdrs.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index 02e9ffb63af1..727792907d6c 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -50,6 +50,7 @@
 #endif
 #include <net/rpl.h>
 #include <linux/ioam6.h>
+#include <linux/ioam6_genl.h>
 #include <net/ioam6.h>
 #include <net/dst_metadata.h>
 
@@ -954,6 +955,9 @@ static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff)
 						   + optoff + sizeof(*hdr));
 
 		ioam6_fill_trace_data(skb, ns, trace, true);
+
+		ioam6_event(IOAM6_EVENT_TRACE, dev_net(skb->dev),
+			    GFP_ATOMIC, (void *)trace, hdr->opt_len - 2);
 		break;
 	default:
 		break;
-- 
2.34.1

Re: [PATCH net-next v5 0/3] ioam6: netlink multicast event

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net-next.git (main)
by David S. Miller <davem@davemloft.net>:

On Mon, 26 Feb 2024 14:14:09 +0100 you wrote:
> v5:
>  - remove the "must be the destination" check before sending an ioam6
>    event
> v4:
>  - rebase on top of net merge
> v3:
>  - patchset was mistakenly superseded due to same cover title used for
>    iproute2-next equivalent patch -> resend (renamed)
> v2:
>  - fix warnings
> 
> [...]

Here is the summary with links:
  - [net-next,v5,1/3] uapi: ioam6: API for netlink multicast events
    https://git.kernel.org/netdev/net-next/c/5fa918a33563
  - [net-next,v5,2/3] net: ioam6: multicast event
    https://git.kernel.org/netdev/net-next/c/67c8e4bb4f54
  - [net-next,v5,3/3] net: exthdrs: ioam6: send trace event
    https://git.kernel.org/netdev/net-next/c/f655c78d6225

You are awesome, thank you!
-- 
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