From: he peilin <redacted>

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

Changelog
---------
v2->v3:
Some fixes according to
https://lore.kernel.org/all/20240319102549.7f7f6f53@gandalf.local.home/ (local)
1. Change the tracking directory to/sys/kernel/tracking.
2. Adjust the layout of the TP-STRUCT_entry parameter structure.

v1->v2:
Some fixes according to
https://lore.kernel.org/all/CANn89iL-y9e_VFpdw=sZtRnKRu_tnUwqHuFQTJvJsv-nz1xPDw@mail.gmail.com/ (local)
1. adjust the trace_icmp_send() to more protocols than UDP.
2. move the calling of trace_icmp_send after sanity checks
in __icmp_send().

Signed-off-by: Peilin He<redacted>
Reviewed-by: xu xin <xu.xin16@zte.com.cn>
Reviewed-by: Yunkai Zhang <redacted>
Cc: Yang Yang <yang.yang29@zte.com.cn>
Cc: Liu Chun <redacted>
Cc: Xuexin Jiang <redacted>
---
 include/trace/events/icmp.h | 64 +++++++++++++++++++++++++++++++++++++
 net/ipv4/icmp.c             |  4 +++
 2 files changed, 68 insertions(+)
 create mode 100644 include/trace/events/icmp.h

diff --git a/include/trace/events/icmp.h b/include/trace/events/icmp.h
new file mode 100644
index 000000000000..2098d4b1b12e
--- /dev/null
+++ b/include/trace/events/icmp.h

@@ -0,0 +1,64 @@
+/* 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 <linux/icmp.h>
+#include <linux/tracepoint.h>
+
+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);
+                       int proto_4 = iph->protocol;
+                       __be32 *p32;
+
+                       __entry->skbaddr = skb;
+                       __entry->type = type;
+                       __entry->code = code;
+
+                       if (proto_4 == IPPROTO_UDP) {
+                               struct udphdr *uh = udp_hdr(skb);
+                               __entry->sport = ntohs(uh->source);
+                               __entry->dport = ntohs(uh->dest);
+                               __entry->ulen = ntohs(uh->len);