From db3efdcf70c752e8a8deb16071d8e693c3ef8746 Mon Sep 17 00:00:00 2001 From: Peilin He Date: Tue, 7 May 2024 15:41:03 +0800 Subject: net/ipv4: add tracepoint for icmp_send Introduce a tracepoint for icmp_send, which can help users to get more detail information conveniently when icmp abnormal events happen. 1. Giving an usecase example: ============================= When an application experiences packet loss due to an unreachable UDP destination port, the kernel will send an exception message through the icmp_send function. By adding a trace point for icmp_send, developers or system administrators can obtain detailed information about the UDP packet loss, including the type, code, source address, destination address, source port, and destination port. This facilitates the trouble-shooting of UDP packet loss issues especially for those network-service applications. 2. Operation Instructions: ========================== Switch to the tracing directory. cd /sys/kernel/tracing Filter for destination port unreachable. echo "type==3 && code==3" > events/icmp/icmp_send/filter Enable trace event. echo 1 > events/icmp/icmp_send/enable 3. Result View: ================ udp_client_erro-11370 [002] ...s.12 124.728002: icmp_send: icmp_send: type=3, code=3. From 127.0.0.1:41895 to 127.0.0.1:6666 ulen=23 skbaddr=00000000589b167a Signed-off-by: Peilin He Signed-off-by: xu xin Reviewed-by: Yunkai Zhang Cc: Yang Yang Cc: Liu Chun Cc: Xuexin Jiang Reviewed-by: Steven Rostedt (Google) Signed-off-by: David S. Miller --- include/trace/events/icmp.h | 67 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+) create mode 100644 include/trace/events/icmp.h (limited to 'include') diff --git a/include/trace/events/icmp.h b/include/trace/events/icmp.h new file mode 100644 index 000000000000..31559796949a --- /dev/null +++ b/include/trace/events/icmp.h @@ -0,0 +1,67 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM icmp + +#if !defined(_TRACE_ICMP_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_ICMP_H + +#include +#include + +TRACE_EVENT(icmp_send, + + TP_PROTO(const struct sk_buff *skb, int type, int code), + + TP_ARGS(skb, type, code), + + TP_STRUCT__entry( + __field(const void *, skbaddr) + __field(int, type) + __field(int, code) + __array(__u8, saddr, 4) + __array(__u8, daddr, 4) + __field(__u16, sport) + __field(__u16, dport) + __field(unsigned short, ulen) + ), + + TP_fast_assign( + struct iphdr *iph = ip_hdr(skb); + struct udphdr *uh = udp_hdr(skb); + int proto_4 = iph->protocol; + __be32 *p32; + + __entry->skbaddr = skb; + __entry->type = type; + __entry->code = code; + + if (proto_4 != IPPROTO_UDP || (u8 *)uh < skb->head || + (u8 *)uh + sizeof(struct udphdr) + > skb_tail_pointer(skb)) { + __entry->sport = 0; + __entry->dport = 0; + __entry->ulen = 0; + } else { + __entry->sport = ntohs(uh->source); + __entry->dport = ntohs(uh->dest); + __entry->ulen = ntohs(uh->len); + } + + p32 = (__be32 *) __entry->saddr; + *p32 = iph->saddr; + + p32 = (__be32 *) __entry->daddr; + *p32 = iph->daddr; + ), + + TP_printk("icmp_send: type=%d, code=%d. From %pI4:%u to %pI4:%u ulen=%d skbaddr=%p", + __entry->type, __entry->code, + __entry->saddr, __entry->sport, __entry->daddr, + __entry->dport, __entry->ulen, __entry->skbaddr) +); + +#endif /* _TRACE_ICMP_H */ + +/* This part must be outside protection */ +#include + -- cgit v1.2.3