lxclock: use XDG_RUNTIME_DIR for lock if appropriate (v2)

If we are euid==0 or XDG_RUNTIME_DIR is not set, then use
/run/lock/lxc/$lxcpath/$lxcname as before.  Otherwise,
use $XDG_RUNTIME_DIR/lock/lxc/$lxcpath/$lxcname.

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Cc: Stéphane Graber <stephane.graber@canonical.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>

diff --git a/src/lxc/lxclock.c b/src/lxc/lxclock.c
index 31bedd8ab772a682f5dfa59a06e44e61d4f510e8..43e76fa73a9273573eaa2bd221d32e99747e18d2 100644 (file)
--- a/src/lxc/lxclock.c
+++ b/src/lxc/lxclock.c
@@ -24,6 +24,8 @@
 #include <errno.h>
 #include <unistd.h>
 #include <fcntl.h>
+#define _GNU_SOURCE
+#include <stdlib.h>
 #include <lxc/utils.h>
 #include <lxc/log.h>
 #include <lxc/lxccontainer.h>
@@ -40,14 +42,29 @@ pthread_mutex_t thread_mutex = PTHREAD_MUTEX_INITIALIZER;
 static char *lxclock_name(const char *p, const char *n)
 {
        int ret;
-       // /run/lock/lxc/$lxcpath/$lxcname + '\0'
-       int len = strlen(p) + strlen(n) + strlen("/run/lock/lxc/") + 2;
-       char *dest = malloc(len);
+       int len;
+       char *dest;
+       const char *rundir;
        struct stat sb;
 
-       if (!dest)
+       /* lockfile will be:
+        * "/run" + "/lock/lxc/$lxcpath/$lxcname + '\0' if root
+        * or
+        * $XDG_RUNTIME_DIR + "/lock/lxc/$lxcpath/$lxcname + '\0' if non-root
+        */
+
+       /* length of "/lock/lxc/" + $lxcpath + "/" + $lxcname + '\0' */
+       len = strlen("/lock/lxc/") + strlen(n) + strlen(p) + 2;
+       rundir = getenv("XDG_RUNTIME_DIR");
+       if (geteuid() == 0 || rundir == NULL)
+               rundir = "/run";
+
+       len += strlen(rundir);
+
+       if ((dest = malloc(len)) == NULL)
                return NULL;
-       ret = snprintf(dest, len, "/run/lock/lxc/%s", p);
+
+       ret = snprintf(dest, len, "%s/lock/lxc/%s", rundir, p);
        if (ret < 0 || ret >= len) {
                free(dest);
                return NULL;
@@ -69,7 +86,7 @@ static char *lxclock_name(const char *p, const char *n)
                        ERROR("Failed to set mode for lockdir %s\n", dest);
        }
 
-       ret = snprintf(dest, len, "/run/lock/lxc/%s/%s", p, n);
+       ret = snprintf(dest, len, "%s/lock/lxc/%s/%s", rundir, p, n);
        if (ret < 0 || ret >= len) {
                free(dest);
                return NULL;