conf: create directory for Unix domain command socket

Try to create the directory where will be the Unix domain command socket
bound to allow starting with empty /var/run. Check the permissions and
owner/group in case the directory already existed. It MUST NOT be
accessible by others as permissions on Unix domain sockets are ignored
on some systems (e.g. Solaris).

conf.c

@@ -1261,8 +1261,26 @@ parse_include(char *line)
 void
 CNF_CreateDirs(uid_t uid, gid_t gid)
 {
+  char *dir;
+
   UTI_CreateDirAndParents(logdir, 0755, uid, gid);
   UTI_CreateDirAndParents(dumpdir, 0755, uid, gid);
+
+  /* Create a directory for the Unix domain command socket */
+  if (bind_cmd_path[0]) {
+    dir = UTI_PathToDir(bind_cmd_path);
+    UTI_CreateDirAndParents(dir, 0770, uid, gid);
+
+    /* Check the permissions and owner/group in case the directory already
+       existed.  It MUST NOT be accessible by others as permissions on Unix
+       domain sockets are ignored on some systems (e.g. Solaris). */
+    if (!UTI_CheckDirPermissions(dir, 0770, uid, gid)) {
+      LOG(LOGS_WARN, LOGF_Configure, "Disabled command socket %s", bind_cmd_path);
+      bind_cmd_path[0] = '\0';
+    }
+
+    Free(dir);
+  }
 }
 
 /* ================================================== */

util.c

@@ -897,6 +897,27 @@ UTI_SetQuitSignalsHandler(void (*handler)(int))
 
 /* ================================================== */
 
+char *
+UTI_PathToDir(const char *path)
+{
+  char *dir, *slash;
+
+  slash = strrchr(path, '/');
+
+  if (!slash)
+    return Strdup(".");
+
+  if (slash == path)
+    return Strdup("/");
+
+  dir = Malloc(slash - path + 1);
+  snprintf(dir, slash - path + 1, "%s", path);
+
+  return dir;
+}
+
+/* ================================================== */
+
 static int
 create_dir(char *p, mode_t mode, uid_t uid, gid_t gid)
 {
@@ -986,3 +1007,33 @@ UTI_CreateDirAndParents(const char *path, mode_t mode, uid_t uid, gid_t gid)
   Free(p);
   return 1;
 }
+
+/* ================================================== */
+
+int
+UTI_CheckDirPermissions(const char *path, mode_t perm, uid_t uid, gid_t gid)
+{
+  struct stat buf;
+
+  if (stat(path, &buf)) {
+    LOG(LOGS_ERR, LOGF_Util, "Could not access %s : %s", path, strerror(errno));
+    return 0;
+  }
+
+  if (!S_ISDIR(buf.st_mode)) {
+    LOG(LOGS_ERR, LOGF_Util, "%s is not directory", path);
+    return 0;
+  }
+
+  if ((buf.st_mode & 0777) & ~perm) {
+    LOG(LOGS_ERR, LOGF_Util, "Wrong permissions on %s", path);
+    return 0;
+  }
+
+  if (buf.st_uid != uid || buf.st_gid != gid) {
+    LOG(LOGS_ERR, LOGF_Util, "Wrong owner/group of %s", path);
+    return 0;
+  }
+
+  return 1;
+}

util.h

@@ -130,10 +130,17 @@ extern int UTI_DecodePasswordFromText(char *key);
 
 extern int UTI_SetQuitSignalsHandler(void (*handler)(int));
 
+/* Get directory (as an allocated string) for a path */
+extern char *UTI_PathToDir(const char *path);
+
 /* Create a directory with a specified mode (umasked) and set its uid/gid
    (if not 0).  Create also any parent directories that don't exist with mode
    755 and default uid/gid.  Returns 1 if created or already exists (even with
    different mode/uid/gid), 0 otherwise. */
 extern int UTI_CreateDirAndParents(const char *path, mode_t mode, uid_t uid, gid_t gid);
 
+/* Check if a directory is secure.  It must not have other than the specified
+   permissions and its uid/gid must match the specified values. */
+extern int UTI_CheckDirPermissions(const char *path, mode_t perm, uid_t uid, gid_t gid);
+
 #endif /* GOT_UTIL_H */