From: Masatake YAMATO <yamato@redhat.com>
Date: Sat, 22 Nov 2014 10:03:33 +0000 (+0900)
Subject: Print protocol name of socket descriptors with -yy option
X-Git-Tag: v4.10~356
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=f548067417e1700e549e1dfe9ffab281258df9cd;p=strace

Print protocol name of socket descriptors with -yy option

For those socket descriptors that have no associated ip:port pairs
(or when this information is not available), -yy option prints
the same <socket:[INODE]> information as -y option, e.g.

$ strace -e sendto -yy ip l > /dev/null
sendto(3<socket:[23456789]>, ...

This change makes -yy output more informative: instead of just
printing "socket", the name of protocol behind the socket descriptor
will be printed, e.g.

sendto(3<NETLINK:[23456789]>, ...

* configure.ac (AC_CHECK_HEADERS): Add sys/xattr.h.
* tests/net-yy-accept.awk: Update to support protocol names.
* tests/net-yy-connect.awk: Likewise.
* util.c [HAVE_SYS_XATTR_H]: Include <sys/xattr.h>.
(getfdproto): New function.
(printfd): Use it.

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
---

diff --git a/configure.ac b/configure.ac
index f9b056d5..47327787 100644
--- a/configure.ac
+++ b/configure.ac
@@ -251,6 +251,7 @@ AC_CHECK_HEADERS(m4_normalize([
 	sys/ptrace.h
 	sys/reg.h
 	sys/vfs.h
+	sys/xattr.h
 ]))
 AC_CHECK_HEADERS([linux/icmp.h linux/in6.h linux/netlink.h linux/if_packet.h],
                  [], [], [#include <stddef.h>
diff --git a/tests/net-yy-accept.awk b/tests/net-yy-accept.awk
index 3ea4afe1..ac3c19af 100644
--- a/tests/net-yy-accept.awk
+++ b/tests/net-yy-accept.awk
@@ -9,7 +9,7 @@ BEGIN {
   r_i = "[1-9][0-9]*"
   r_port = "[1-9][0-9][0-9][0-9]+"
   r_localhost = "127\\.0\\.0\\.1"
-  r_bind = "^bind\\(0<socket:\\[(" r_i ")\\]>, {sa_family=AF_INET, sin_port=htons\\(0\\), sin_addr=inet_addr\\(\"" r_localhost "\"\\)}, " r_i "\\) += 0$"
+  r_bind = "^bind\\(0<(TCP|socket):\\[(" r_i ")\\]>, {sa_family=AF_INET, sin_port=htons\\(0\\), sin_addr=inet_addr\\(\"" r_localhost "\"\\)}, " r_i "\\) += 0$"
   r_listen = "^/$"
   r_getsockname = "^getsockname\\(0<" r_localhost ":(" r_port ")>, {sa_family=AF_INET, sin_port=htons\\((" r_port ")\\), sin_addr=inet_addr\\(\"" r_localhost "\"\\)}, \\[" r_i "\\]\\) += 0$"
   r_accept = "^/$"
@@ -23,8 +23,8 @@ NR == 1 && /^socket\(PF_INET, SOCK_STREAM, IPPROTO_IP\) += 0$/ {next}
 
 NR == 2 {
   if (match($0, r_bind, a)) {
-    inode = a[1]
-    r_listen = "^listen\\(0<socket:\\[" inode "\\]>, 5\\) += 0$"
+    inode = a[2]
+    r_listen = "^listen\\(0<(TCP|socket):\\[" inode "\\]>, 5\\) += 0$"
     next
   }
 }
diff --git a/tests/net-yy-connect.awk b/tests/net-yy-connect.awk
index 18c1a28d..c7c63af2 100644
--- a/tests/net-yy-connect.awk
+++ b/tests/net-yy-connect.awk
@@ -8,7 +8,7 @@ BEGIN {
   r_i = "[1-9][0-9]*"
   r_port = "[1-9][0-9][0-9][0-9]+"
   r_localhost = "127\\.0\\.0\\.1"
-  r_connect = "^connect\\(0<socket:\\[" r_i "\\]>, {sa_family=AF_INET, sin_port=htons\\((" r_port ")\\), sin_addr=inet_addr\\(\"" r_localhost "\"\\)}, " r_i ") += 0$"
+  r_connect = "^connect\\(0<(TCP|socket):\\[" r_i "\\]>, {sa_family=AF_INET, sin_port=htons\\((" r_port ")\\), sin_addr=inet_addr\\(\"" r_localhost "\"\\)}, " r_i ") += 0$"
   r_send = "^/$"
   r_sendto = "^/$"
   r_close = "^/$"
@@ -18,7 +18,7 @@ NR == 1 && /^socket\(PF_INET, SOCK_STREAM, IPPROTO_IP\) += 0$/ {next}
 
 NR == 2 {
   if (match($0, r_connect, a)) {
-    port_r = a[1]
+    port_r = a[2]
     r_send = "^send\\(0<" r_localhost ":(" r_port ")->" r_localhost ":" port_r ">, \"data\", 4, MSG_DONTROUTE\\) += 4$"
     r_sendto = "^sendto\\(0<" r_localhost ":(" r_port ")->" r_localhost ":" port_r ">, \"data\", 4, MSG_DONTROUTE, NULL, 0\\) += 4$"
     next
diff --git a/util.c b/util.c
index 4f637e83..cd4b8022 100644
--- a/util.c
+++ b/util.c
@@ -35,6 +35,9 @@
 #include <sys/user.h>
 #include <sys/param.h>
 #include <fcntl.h>
+#if HAVE_SYS_XATTR_H
+# include <sys/xattr.h>
+#endif
 #include <sys/uio.h>
 
 #if defined(IA64)
@@ -418,6 +421,33 @@ printnum_int(struct tcb *tcp, long addr, const char *fmt)
 	tprints("]");
 }
 
+static char *
+getfdproto(struct tcb *tcp, int fd, char *buf, unsigned bufsize)
+{
+#if HAVE_SYS_XATTR_H
+	ssize_t r;
+	char path[sizeof("/proc/%u/fd/%u") + 2 * sizeof(int)*3];
+
+	if (fd < 0)
+		return NULL;
+
+	sprintf(path, "/proc/%u/fd/%u", tcp->pid, fd);
+	r = getxattr(path, "system.sockprotoname", buf, bufsize - 1);
+	if (r <= 0)
+		return NULL;
+	else {
+		/*
+		 * This is a protection for the case when the kernel
+		 * side does not append a null byte to the buffer.
+		 */
+		buf[r] = '\0';
+		return buf;
+	}
+#else
+	return NULL;
+#endif
+}
+
 void
 printfd(struct tcb *tcp, int fd)
 {
@@ -433,8 +463,17 @@ printfd(struct tcb *tcp, int fd)
 			unsigned long inodenr;
 			inodenr = strtoul(path + socket_prefix_len, NULL, 10);
 			tprintf("%d<", fd);
-			if (!print_sockaddr_by_inode(inodenr))
-				tprints(path);
+			if (!print_sockaddr_by_inode(inodenr)) {
+#define PROTO_NAME_LEN 32
+				char proto_buf[PROTO_NAME_LEN];
+				const char *proto =
+					getfdproto(tcp, fd, proto_buf, PROTO_NAME_LEN);
+
+				if (proto)
+					tprintf("%s:[%lu]", proto, inodenr);
+				else
+					tprints(path);
+			}
 			tprints(">");
 		} else {
 			tprintf("%d<%s>", fd, path);