Re: Re: [PATCH v2] net/ipv4: add tracepoint for icmp_send

2024-03-20 Thread He Peilin
> > From: Peilin He
> > 
> > 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/debug/tracing
> 
> FYI, that directory is obsolete. Please always reference /sys/kernel/tracing.
OK. 
> > 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: ulen=23
> >  skbaddr=589b167a
> > 
> > v1->v2:
> > Some fixes according to
> > https://lore.kernel.org/all/CANn89iL-y9e_VFpdw=sztrnkru_tnuwqhufqtjvjsv-nz1x...@mail.gmail.com/
> > 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
> > Reviewed-by: xu xin 
> > Reviewed-by: Yunkai Zhang 
> > Cc: Yang Yang 
> > Cc: Liu Chun 
> > Cc: Xuexin Jiang 
> > ---
> >  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 ..c3dc337be7bc
> > --- /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 
> > +#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(__u16, sport)
> > +   __field(__u16, dport)
> > +   __field(int, type)
> > +   __field(int, code)
> > +   __array(__u8, saddr, 4)
> > +   __array(__u8, daddr, 4)
> > +   __field(const void *, skbaddr)
> > +   __field(unsigned short, ulen)
> 
> Note, to prevent holes, I usually suggest pointers and longs go first,
> followed by ints, and then end with char.
> 
>   __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)
> 
> -- Steve
Thank you very much for your suggestion. We will rearrange the parameters in 
TP_STRUCT_entry, prioritizing pointers and longs, followed by ints, and ending 
with char. This will be reflected in Patch v3.
> 
> 
> > +   ),
> > +
> > +   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);
> > +   } else {
> > +   __entry->sport = 0;
> > +   __entry->dport = 0;
> > +   __entry->ulen = 0;
> > +   }
> > +
> > +   p32 = (__be32 *) __entry->saddr;
> > +   *p32 = iph->saddr;
> > +
> > +   p32 = (__be32 *) __entry->daddr;
> > +   *p32 = iph->daddr;
> > + 

Re: [PATCH v2] net/ipv4: add tracepoint for icmp_send

2024-03-19 Thread Steven Rostedt
On Tue, 19 Mar 2024 20:13:52 +0800 (CST)
 wrote:

> From: Peilin He
> 
> 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/debug/tracing

FYI, that directory is obsolete. Please always reference /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: ulen=23
>  skbaddr=589b167a
> 
> v1->v2:
> Some fixes according to
> https://lore.kernel.org/all/CANn89iL-y9e_VFpdw=sztrnkru_tnuwqhufqtjvjsv-nz1x...@mail.gmail.com/
>   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
> Reviewed-by: xu xin 
> Reviewed-by: Yunkai Zhang 
> Cc: Yang Yang 
> Cc: Liu Chun 
> Cc: Xuexin Jiang 
> ---
>  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 ..c3dc337be7bc
> --- /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 
> +#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(__u16, sport)
> + __field(__u16, dport)
> + __field(int, type)
> + __field(int, code)
> + __array(__u8, saddr, 4)
> + __array(__u8, daddr, 4)
> + __field(const void *, skbaddr)
> + __field(unsigned short, ulen)

Note, to prevent holes, I usually suggest pointers and longs go first,
followed by ints, and then end with char.

__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)

-- Steve


> + ),
> +
> + 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);
> + } else {
> + __entry->sport = 0;
> + __entry->dport = 0;
> + __entry->ulen = 0;
> + }
> +
> + 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)
> +);

[PATCH v2] net/ipv4: add tracepoint for icmp_send

2024-03-19 Thread xu.xin16
From: Peilin He

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/debug/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: ulen=23
 skbaddr=589b167a

v1->v2:
Some fixes according to
https://lore.kernel.org/all/CANn89iL-y9e_VFpdw=sztrnkru_tnuwqhufqtjvjsv-nz1x...@mail.gmail.com/
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
Reviewed-by: xu xin 
Reviewed-by: Yunkai Zhang 
Cc: Yang Yang 
Cc: Liu Chun 
Cc: Xuexin Jiang 
---
 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 ..c3dc337be7bc
--- /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 
+#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(__u16, sport)
+   __field(__u16, dport)
+   __field(int, type)
+   __field(int, code)
+   __array(__u8, saddr, 4)
+   __array(__u8, daddr, 4)
+   __field(const void *, skbaddr)
+   __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);
+   } else {
+   __entry->sport = 0;
+   __entry->dport = 0;
+   __entry->ulen = 0;
+   }
+
+   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 
\ No newline at end of file
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index e63a3bf99617..21fb41257fe9 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -92,6 +92,8 @@
 #include 
 #include 
 #include 
+#define CREATE_TRACE_POINTS
+#include 

 /*
  * Build xmit assembly blocks
@@ -672,6 +674,8 @@ void __icmp_send(struct sk_buff *skb_in, int type, int 
code, __be32 info,
}
}

+   trace_icmp_send(skb_in, type, code);
+
/* Needed by both icmp_global_allow and icmp_xmit_lock */
local_bh_disable();

-- 
2.15.2