From: Masatake YAMATO <yamato@redhat.com>
Date: Wed, 26 Oct 2022 02:56:00 +0000 (+0900)
Subject: lsfd: make the logic for verifying the initial line of /proc/net/{tcp,udp} more flexible
X-Git-Tag: v2.39-rc1~448^2~1
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=b49529f06f282b5c5e1e6da5c776f103d0db1d13;p=thirdparty%2Futil-linux.git

lsfd: make the logic for verifying the initial line of /proc/net/{tcp,udp} more flexible

The format of /proc/net/udp was changed in
6c25449e1a32 ("net: udp: fix alignment problem in udp4_seq_show()").
This kind of change can be applied to /proc/net/tcp, too.

Co-Authored-by: Thomas Weißschuh <thomas@t-8ch.de>
Co-Authored-by: Masatake YAMATO <yamato@redhat.com>
---

diff --git a/misc-utils/lsfd-sock-xinfo.c b/misc-utils/lsfd-sock-xinfo.c
index 1ef2f40b7c..263ffc36e9 100644
--- a/misc-utils/lsfd-sock-xinfo.c
+++ b/misc-utils/lsfd-sock-xinfo.c
@@ -654,10 +654,19 @@ static void load_xinfo_from_proc_inet_L3(ino_t netns_inode, const char *proc_fil
 
 static bool tcp_verify_initial_line(const char *line)
 {
-	return (line[0] == ' ' && line[1] == ' '
-		&& line[2] == 's' && line[3] == 'l');
+	/* At least we expect two white spaces. */
+	if (strncmp (line, "  ", 2) != 0)
+		return false;
+	line += 2;
+
+	/* Skip white spaces. */
+	while (*line == ' ')
+		line++;
+
+	return (strncmp(line, "sl", 2) == 0);
 }
 
+
 static void load_xinfo_from_proc_tcp(ino_t netns_inode)
 {
 	load_xinfo_from_proc_inet_L3(netns_inode,
@@ -711,17 +720,10 @@ static struct sock_xinfo_class udp_xinfo_class = {
 	.free = NULL,
 };
 
-static bool udp_verify_initial_line(const char *line)
-{
-	return (line[0] == ' ' && line[1] == ' ' && line[2] == ' '
-		&& line[3] == 's' && line[4] == 'l');
-}
-
-
 static void load_xinfo_from_proc_udp(ino_t netns_inode)
 {
 	load_xinfo_from_proc_inet_L3(netns_inode,
 				     "/proc/net/udp",
-				     udp_verify_initial_line,
+				     tcp_verify_initial_line,
 				     &udp_xinfo_class);
 }