It wasn't obvious to me the best way to pass in a pointer to the ipv4
(and ipv6 address) to a dynamic trace point (unless I create a temp
string first in generic_ip_connect and do the conversion (via "%pI4"
and "%pI6" with sprintf) e.g.
sprintf(ses->ip_addr, "%pI4", &addr->sin_addr);
The approach I tried passing in the pointer to sin_addr (the
ipv4_address) caused an oops on loading it the first time and the
warning:
[14928.818532] event smb3_ipv4_connect has unsafe dereference of argument 3
[14928.818534] print_fmt: "conn_id=0x%llx server=%s addr=%pI4:%d",
REC->conn_id, __get_str(hostname), REC->ipaddr, REC->port
What I tried was the following (also see attached diff) to print the
ipv4 address that we were trying to connect to
DECLARE_EVENT_CLASS(smb3_connect_class,
TP_PROTO(char *hostname,
__u64 conn_id,
__u16 port,
struct in_addr *ipaddr),
TP_ARGS(hostname, conn_id, port, ipaddr),
TP_STRUCT__entry(
__string(hostname, hostname)
__field(__u64, conn_id)
__field(__u16, port)
__field(const void *, ipaddr)
),
TP_fast_assign(
__entry->port = port;
__entry->conn_id = conn_id;
__entry->ipaddr = ipaddr;
__assign_str(hostname, hostname);
),
TP_printk("conn_id=0x%llx server=%s addr=%pI4:%d",
__entry->conn_id,
__get_str(hostname),
__entry->ipaddr,
__entry->port)
)
#define DEFINE_SMB3_CONNECT_EVENT(name) \
DEFINE_EVENT(smb3_connect_class, smb3_##name, \
TP_PROTO(char *hostname, \
__u64 conn_id, \
__u16 port, \
struct in_addr *ipaddr), \
TP_ARGS(hostname, conn_id, port, ipaddr))
DEFINE_SMB3_CONNECT_EVENT(ipv4_connect);
Any ideas how to pass in the ipv4 address - or is it better to convert
it to a string before we call the trace point (which seems wasteful to
me but there must be examples of how to pass in structs to printks in
trace in Linux)
--
Thanks,
Steve
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index e6e261dfd107..4cbfca90a47c 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -2590,6 +2590,8 @@ generic_ip_connect(struct TCP_Server_Info *server)
sfamily = AF_INET;
cifs_dbg(FYI, "%s: connecting to %pI4:%d\n", __func__, &ipv4->sin_addr,
ntohs(sport));
+ trace_smb3_ipv4_connect(server->hostname, server->conn_id,
+ ntohs(sport), &ipv4->sin_addr);
}
if (socket == NULL) {
diff --git a/fs/cifs/trace.h b/fs/cifs/trace.h
index dafcb6ab050d..3162f484fb85 100644
--- a/fs/cifs/trace.h
+++ b/fs/cifs/trace.h
@@ -11,7 +11,7 @@
#define _CIFS_TRACE_H
#include <linux/tracepoint.h>
-
+#include <linux/inet.h>
/*
* Please use this 3-part article as a reference for writing new tracepoints:
* https://lwn.net/Articles/379903/
@@ -854,6 +854,41 @@ DEFINE_EVENT(smb3_lease_err_class, smb3_##name, \
DEFINE_SMB3_LEASE_ERR_EVENT(lease_err);
+DECLARE_EVENT_CLASS(smb3_connect_class,
+ TP_PROTO(char *hostname,
+ __u64 conn_id,
+ __u16 port,
+ struct in_addr *ipaddr),
+ TP_ARGS(hostname, conn_id, port, ipaddr),
+ TP_STRUCT__entry(
+ __string(hostname, hostname)
+ __field(__u64, conn_id)
+ __field(__u16, port)
+ __field(const void *, ipaddr)
+ ),
+ TP_fast_assign(
+ __entry->port = port;
+ __entry->conn_id = conn_id;
+ __entry->ipaddr = ipaddr;
+ __assign_str(hostname, hostname);
+ ),
+ TP_printk("conn_id=0x%llx server=%s addr=%pI4:%d",
+ __entry->conn_id,
+ __get_str(hostname),
+ __entry->ipaddr,
+ __entry->port)
+)
+
+#define DEFINE_SMB3_CONNECT_EVENT(name) \
+DEFINE_EVENT(smb3_connect_class, smb3_##name, \
+ TP_PROTO(char *hostname, \
+ __u64 conn_id, \
+ __u16 port, \
+ struct in_addr *ipaddr), \
+ TP_ARGS(hostname, conn_id, port, ipaddr))
+
+DEFINE_SMB3_CONNECT_EVENT(ipv4_connect);
+
DECLARE_EVENT_CLASS(smb3_reconnect_class,
TP_PROTO(__u64 currmid,
__u64 conn_id,
