Commit e6091ba5 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'add-ip-port-information-to-udp-drop-tracepoint' 

Balazs Scheidler says:

====================
Add IP/port information to UDP drop tracepoint

In our use-case we would like to recover the properties of dropped UDP
packets. Unfortunately the current udp_fail_queue_rcv_skb tracepoint
only exposes the port number of the receiving socket.

This patch-set will add the source/dest ip/port to the tracepoint, while
keeping the socket's local port as well for compatibility.

Thanks for the review comments by Jason and Kuniyuki, they helped me a lot
and I tried to address all of their comments in this new iteration.
====================

Link: https://lore.kernel.org/r/cover.1711475011.git.balazs.scheidler@axoflow.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents b7b1c590 e9669a00

include/trace/events/net_probe_common.h

+40 −0
Original line number Diff line number Diff line
@@ -70,4 +70,44 @@ 
	TP_STORE_V4MAPPED(__entry, saddr, daddr)

#endif



#define TP_STORE_ADDR_PORTS_SKB_V4(__entry, skb, protoh)		\

	do {								\

		struct sockaddr_in *v4 = (void *)__entry->saddr;	\

									\

		v4->sin_family = AF_INET;				\

		v4->sin_port = protoh->source;				\

		v4->sin_addr.s_addr = ip_hdr(skb)->saddr;		\

		v4 = (void *)__entry->daddr;				\

		v4->sin_family = AF_INET;				\

		v4->sin_port = protoh->dest;				\

		v4->sin_addr.s_addr = ip_hdr(skb)->daddr;		\

	} while (0)



#if IS_ENABLED(CONFIG_IPV6)



#define TP_STORE_ADDR_PORTS_SKB(__entry, skb, protoh)			\

	do {								\

		const struct iphdr *iph = ip_hdr(skb);			\

									\

		if (iph->version == 6) {				\

			struct sockaddr_in6 *v6 = (void *)__entry->saddr; \

									\

			v6->sin6_family = AF_INET6;			\

			v6->sin6_port = protoh->source;			\

			v6->sin6_addr = ipv6_hdr(skb)->saddr;		\

			v6 = (void *)__entry->daddr;			\

			v6->sin6_family = AF_INET6;			\

			v6->sin6_port = protoh->dest;			\

			v6->sin6_addr = ipv6_hdr(skb)->daddr;		\

		} else							\

			TP_STORE_ADDR_PORTS_SKB_V4(__entry, skb, protoh); \

	} while (0)



#else



#define TP_STORE_ADDR_PORTS_SKB(__entry, skb, protoh)		\

	TP_STORE_ADDR_PORTS_SKB_V4(__entry, skb, protoh)



#endif



#endif

include/trace/events/tcp.h

+2 −43
Original line number Diff line number Diff line
@@ -273,48 +273,6 @@ TRACE_EVENT(tcp_probe, 
		  __entry->skbaddr, __entry->skaddr)

);



#define TP_STORE_ADDR_PORTS_SKB_V4(__entry, skb)			\

	do {								\

		const struct tcphdr *th = (const struct tcphdr *)skb->data; \

		struct sockaddr_in *v4 = (void *)__entry->saddr;	\

									\

		v4->sin_family = AF_INET;				\

		v4->sin_port = th->source;				\

		v4->sin_addr.s_addr = ip_hdr(skb)->saddr;		\

		v4 = (void *)__entry->daddr;				\

		v4->sin_family = AF_INET;				\

		v4->sin_port = th->dest;				\

		v4->sin_addr.s_addr = ip_hdr(skb)->daddr;		\

	} while (0)



#if IS_ENABLED(CONFIG_IPV6)



#define TP_STORE_ADDR_PORTS_SKB(__entry, skb)				\

	do {								\

		const struct iphdr *iph = ip_hdr(skb);			\

									\

		if (iph->version == 6) {				\

			const struct tcphdr *th = (const struct tcphdr *)skb->data; \

			struct sockaddr_in6 *v6 = (void *)__entry->saddr; \

									\

			v6->sin6_family = AF_INET6;			\

			v6->sin6_port = th->source;			\

			v6->sin6_addr = ipv6_hdr(skb)->saddr;		\

			v6 = (void *)__entry->daddr;			\

			v6->sin6_family = AF_INET6;			\

			v6->sin6_port = th->dest;			\

			v6->sin6_addr = ipv6_hdr(skb)->daddr;		\

		} else							\

			TP_STORE_ADDR_PORTS_SKB_V4(__entry, skb);	\

	} while (0)



#else



#define TP_STORE_ADDR_PORTS_SKB(__entry, skb)		\

	TP_STORE_ADDR_PORTS_SKB_V4(__entry, skb)



#endif



/*

 * tcp event with only skb

 */
@@ -331,12 +289,13 @@ DECLARE_EVENT_CLASS(tcp_event_skb, 
	),



	TP_fast_assign(

		const struct tcphdr *th = (const struct tcphdr *)skb->data;

		__entry->skbaddr = skb;



		memset(__entry->saddr, 0, sizeof(struct sockaddr_in6));

		memset(__entry->daddr, 0, sizeof(struct sockaddr_in6));



		TP_STORE_ADDR_PORTS_SKB(__entry, skb);

		TP_STORE_ADDR_PORTS_SKB(__entry, skb, th);

	),



	TP_printk("skbaddr=%p src=%pISpc dest=%pISpc",

include/trace/events/udp.h

+24 −5
Original line number Diff line number Diff line
@@ -7,24 +7,43 @@ 


#include <linux/udp.h>

#include <linux/tracepoint.h>

#include <trace/events/net_probe_common.h>



TRACE_EVENT(udp_fail_queue_rcv_skb,



	TP_PROTO(int rc, struct sock *sk),

	TP_PROTO(int rc, struct sock *sk, struct sk_buff *skb),



	TP_ARGS(rc, sk),

	TP_ARGS(rc, sk, skb),



	TP_STRUCT__entry(

		__field(int, rc)

		__field(__u16, lport)



		__field(__u16, sport)

		__field(__u16, dport)

		__field(__u16, family)

		__array(__u8, saddr, sizeof(struct sockaddr_in6))

		__array(__u8, daddr, sizeof(struct sockaddr_in6))

	),



	TP_fast_assign(

		const struct udphdr *uh = (const struct udphdr *)udp_hdr(skb);



		__entry->rc = rc;

		__entry->lport = inet_sk(sk)->inet_num;



		/* for filtering use */

		__entry->sport = ntohs(uh->source);

		__entry->dport = ntohs(uh->dest);

		__entry->family = sk->sk_family;



		memset(__entry->saddr, 0, sizeof(struct sockaddr_in6));

		memset(__entry->daddr, 0, sizeof(struct sockaddr_in6));



		TP_STORE_ADDR_PORTS_SKB(__entry, skb, uh);

	),



	TP_printk("rc=%d port=%hu", __entry->rc, __entry->lport)

	TP_printk("rc=%d family=%s src=%pISpc dest=%pISpc", __entry->rc,

		  show_family_name(__entry->family),

		  __entry->saddr, __entry->daddr)

);



#endif /* _TRACE_UDP_H */

net/ipv4/udp.c

+1 −1
Original line number Diff line number Diff line
@@ -2049,8 +2049,8 @@ static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 
			drop_reason = SKB_DROP_REASON_PROTO_MEM;

		}

		UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);

		trace_udp_fail_queue_rcv_skb(rc, sk, skb);

		kfree_skb_reason(skb, drop_reason);

		trace_udp_fail_queue_rcv_skb(rc, sk);

		return -1;

	}

net/ipv6/udp.c

+2 −1
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ 
#include <linux/slab.h>

#include <linux/uaccess.h>

#include <linux/indirect_call_wrapper.h>

#include <trace/events/udp.h>



#include <net/addrconf.h>

#include <net/ndisc.h>
@@ -658,8 +659,8 @@ static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 
			drop_reason = SKB_DROP_REASON_PROTO_MEM;

		}

		UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);

		trace_udp_fail_queue_rcv_skb(rc, sk, skb);

		kfree_skb_reason(skb, drop_reason);

		trace_udp_fail_queue_rcv_skb(rc, sk);

		return -1;

	}