mount: use TMPDIR to create a temporary dir

diff --git a/mount.c b/mount.c
index 75b2706128d70c459e3663102fe8f9c568d97661..22631656cea7b09e647e66678081408185579ab7 100644 (file)
--- a/mount.c
+++ b/mount.c
@@ -248,33 +248,31 @@ static bool mountMkdirAndTest(const char *dir)
        return true;
 }
 
-static bool mountGetDirs(struct nsjconf_t *nsjconf, char *destdir, char *tmpdir)
+static bool mountGetDir(struct nsjconf_t *nsjconf, char *dir, const char *name)
 {
-       snprintf(destdir, PATH_MAX, "/tmp/nsjail.root.%d", (int)nsjconf->orig_euid);
-       if (!mountMkdirAndTest(destdir)) {
-               snprintf(destdir, PATH_MAX, "/tmp/nsjail.root");
-               if (!mountMkdirAndTest(destdir)) {
-                       snprintf(destdir, PATH_MAX, "/tmp/nsjail.root.%" PRIx64, utilRnd64());
-                       if (!mountMkdirAndTest(destdir)) {
-                               LOG_E("Couldn't create directory for ROOT fs");
-                               return false;
-                       }
-               }
+       snprintf(dir, PATH_MAX, "/tmp/nsjail.%s", name);
+       if (mountMkdirAndTest(dir)) {
+               return true;
+       }
+       snprintf(dir, PATH_MAX, "/tmp/nsjail.%s.%d", name, (int)nsjconf->orig_euid);
+       if (mountMkdirAndTest(dir)) {
+               return true;
+       }
+       snprintf(dir, PATH_MAX, "/tmp/nsjail.%s.%" PRIx64, name, utilRnd64());
+       if (mountMkdirAndTest(dir)) {
+               return true;
        }
 
-       snprintf(tmpdir, PATH_MAX, "/tmp/nsjail.tmp.%d", (int)nsjconf->orig_euid);
-       if (!mountMkdirAndTest(tmpdir)) {
-               snprintf(tmpdir, PATH_MAX, "/tmp/nsjail.tmp");
-               if (!mountMkdirAndTest(tmpdir)) {
-                       snprintf(tmpdir, PATH_MAX, "/tmp/nsjail.tmp.%" PRIx64, utilRnd64());
-                       if (!mountMkdirAndTest(tmpdir)) {
-                               LOG_E("Couldn't create a directory for TMP files");
-                               return false;
-                       }
+       const char *tmp = getenv("TMPDIR");
+       if (tmp) {
+               snprintf(dir, PATH_MAX, "%s/nsjail.%s", name, tmp);
+               if (mountMkdirAndTest(dir)) {
+                       return true;
                }
        }
 
-       return true;
+       LOG_E("Couldn't create tmp directory of type '%s'", name);
+       return false;
 }
 
 static bool mountInitNsInternal(struct nsjconf_t *nsjconf)
@@ -298,9 +296,8 @@ static bool mountInitNsInternal(struct nsjconf_t *nsjconf)
        }
 
        char destdir[PATH_MAX];
-       char tmpdir[PATH_MAX];
-       if (mountGetDirs(nsjconf, destdir, tmpdir) == false) {
-               LOG_E("Couldn't obtain temporary mount directories");
+       if (mountGetDir(nsjconf, destdir, "root") == false) {
+               LOG_E("Couldn't obtain root mount directories");
                return false;
        }
 
@@ -309,6 +306,11 @@ static bool mountInitNsInternal(struct nsjconf_t *nsjconf)
                return false;
        }
 
+       char tmpdir[PATH_MAX];
+       if (mountGetDir(nsjconf, tmpdir, "tmp") == false) {
+               LOG_E("Couldn't obtain temporary mount directories");
+               return false;
+       }
        if (mount(NULL, tmpdir, "tmpfs", 0, "size=16777216") == -1) {
                PLOG_E("mount('%s', 'tmpfs')", tmpdir);
                return false;