[PATCH] start-stop-daemon: make --exec follow symlinks.
Joakim Tjernlund
joakim.tjernlund at transmode.se
Fri Apr 18 09:32:48 UTC 2008
Currently start-stop-daemon --stop --exec <file> does not follow
symlinks and this is wrong.
This patch uses stat(2) to get the file's st_dev and st_ino and searches
for a matching pair. A positive side effect is the right file is always
found. The code is also smaller.
The stat(2) method is also used by debian.
This patch is also against 1.8.2 gentoo
--- a/debianutils/start_stop_daemon.c.org 2008-04-18 11:01:39.000000000 +0200
+++ b/debianutils/start_stop_daemon.c 2008-04-18 11:02:43.000000000 +0200
@@ -23,6 +23,7 @@
static char *userspec;
static char *cmdname;
static char *execname;
+static struct stat execstat;
static char *pidfile;
static smallint quiet;
@@ -36,19 +37,15 @@
static int pid_is_exec(pid_t pid, const char *name)
{
char buf[sizeof("/proc//exe") + sizeof(int)*3];
- char *execbuf;
- int n;
+ struct stat st;
sprintf(buf, "/proc/%u/exe", pid);
- n = strlen(name) + 1;
- execbuf = xzalloc(n + 1);
- readlink(buf, execbuf, n);
-
- /* if readlink fails, execbuf still contains "" */
- n = strcmp(execbuf, name);
- if (ENABLE_FEATURE_CLEAN_UP)
- free(execbuf);
- return !n; /* nonzero (true) if execbuf == name */
+ if (stat(buf, &st) <0)
+ return 0;
+ if (st.st_dev == execstat.st_dev &&
+ st.st_ino == execstat.st_ino)
+ return 1;
+ return 0;
}
static int pid_is_user(int pid, int uid)
@@ -288,6 +285,8 @@
if (errno)
user_id = xuname2uid(userspec);
}
+ if (execname)
+ stat(execname, &execstat);
if (opt & CTX_STOP) {
int i = do_stop();
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