email plugin: Change owner and mode of the UNIX socket if possible.

Set the owner and mode to COLLECTD_GRP_NAME (defaulting to "collectd") and 0770
respectively. A couple of different daemons running as different users might
want to connect to it.

Signed-off-by: Sebastian Harl <sh@tokkee.org>

diff --git a/configure.in b/configure.in
index ca10e21..823845a 100644 (file)
--- a/configure.in
+++ b/configure.in
@@ -277,6 +277,7 @@ AC_CHECK_HEADERS(linux/un.h, [], [],
 #endif
 ])
 AC_CHECK_HEADERS(sys/un.h)
+AC_CHECK_HEADERS(grp.h)
 
 # For debugging interface (variable number of arguments)
 AC_CHECK_HEADERS(stdarg.h)

diff --git a/src/collectd.h b/src/collectd.h
index 4d75db4..d8f74f9 100644 (file)
--- a/src/collectd.h
+++ b/src/collectd.h
@@ -200,6 +200,10 @@
 #define MODE_LOCAL  0x04
 #define MODE_LOG    0x08
 
+#ifndef COLLECTD_GRP_NAME
+#      define COLLECTD_GRP_NAME "collectd"
+#endif
+
 #ifndef COLLECTD_STEP
 #  define COLLECTD_STEP "10"
 #endif

diff --git a/src/email.c b/src/email.c
index 5f612cd..27370ae 100644 (file)
--- a/src/email.c
+++ b/src/email.c
@@ -55,6 +55,10 @@
 #      include <sys/un.h>
 #endif /* HAVE_LINUX_UN_H | HAVE_SYS_UN_H */
 
+#if HAVE_GRP_H
+#      include <grp.h>
+#endif /* HAVE_GRP_H */
+
 #define MODULE_NAME "email"
 
 /* 256 bytes ought to be enough for anybody ;-) */
@@ -484,6 +488,29 @@ static void *open_connection (void *arg)
                pthread_exit ((void *)1);
        }
 
+       if ((uid_t)0 == geteuid ()) {
+               struct group *grp;
+
+               errno = 0;
+               if (NULL != (grp = getgrnam (COLLECTD_GRP_NAME))) {
+                       errno = 0;
+                       if (0 != chown (SOCK_PATH, (uid_t)-1, grp->gr_gid)) {
+                               syslog (LOG_WARNING, "chown() failed: %s", strerror (errno));
+                       }
+               }
+               else {
+                       syslog (LOG_WARNING, "getgrnam() failed: %s", strerror (errno));
+               }
+       }
+       else {
+               syslog (LOG_WARNING, "not running as root");
+       }
+
+       errno = 0;
+       if (0 != chmod (SOCK_PATH, S_IRWXU | S_IRWXG)) {
+               syslog (LOG_WARNING, "chmod() failed: %s", strerror (errno));
+       }
+
        { /* initialize queue of available threads */
                int i = 0;