BUG/MINOR: server: check strdup return on server-template ID generation

Check strdup() return value when a server-template prefix is expanded
into the final server name. Now, an alert is reported in case of error
and server parsing is interrupted.

Along with this change, the server prefix expansion function has been
renamed and its documentation adjusted.

This could be backported to all stable releases. However, this depends
on a previous patch which prevents ignoring of errors during
server-template generation. As this is a minor fix which is only useful
after memory allocation failure, it is probably better to not pick them.
If backporting is considered necessary, the following patch is required
first.

  commit 467440a34f81c635ccb33d434328799b027cbf03
  MINOR: server: do not ignore errors during server-template init

diff --git a/src/server.c b/src/server.c
index 5fda7bc4c4913a5853ff7077c481a6bda263b711..d342aaca555181207c9d6d60132bc80e3133f40b 100644 (file)
--- a/src/server.c
+++ b/src/server.c
@@ -3365,22 +3365,13 @@ static int _srv_parse_tmpl_range(struct server *srv, const char *arg,
        return 0;
 }
 
-/* Parse as much as possible such a range string argument: low[-high]
- * Set <nb_low> and <nb_high> values so that they may be reused by this loop
- * for(int i = nb_low; i <= nb_high; i++)... with nb_low >= 1.
- *
- * This function is first intended to be used through parse_server to
- * initialize a new server on startup.
- *
- * Fails if 'low' < 0 or 'high' is present and not higher than 'low'.
- * Returns 0 if succeeded, -1 if not.
+/* Generate a server ID from <prefix> and <nb>. Used for server-template.
+ * Returns a newly allocated string or NULL.
  */
-static inline void _srv_parse_set_id_from_prefix(struct server *srv,
-                                                 const char *prefix, int nb)
+static inline char *server_set_id_from_prefix(const char *prefix, int nb)
 {
        chunk_printf(&trash, "%s%d", prefix, nb);
-       free(srv->id);
-       srv->id = strdup(trash.area);
+       return strdup(trash.area);
 }
 
 /* Parse the sni and pool-conn-name expressions. Returns 0 on success and non-zero on
@@ -3459,7 +3450,14 @@ static int _srv_parse_tmpl_init(struct server *srv, struct proxy *px)
        char *msg = NULL;
 
        /* Set the first server's ID. */
-       _srv_parse_set_id_from_prefix(srv, srv->tmpl_info.prefix, srv->tmpl_info.nb_low);
+       srv->id = server_set_id_from_prefix(srv->tmpl_info.prefix,
+                                           srv->tmpl_info.nb_low);
+       if (!srv->id) {
+               ha_alert("out of memory");
+               err_code = ERR_ALERT | ERR_ABORT;
+               goto out;
+       }
+
        cebis_item_insert(&curproxy->conf.used_server_name, conf.name_node, id, srv);
 
        /* then create other servers from this one */
@@ -3488,7 +3486,12 @@ static int _srv_parse_tmpl_init(struct server *srv, struct proxy *px)
                        LIST_APPEND(&newsrv->srvrq->attached_servers, &newsrv->srv_rec_item);
 
                /* Set this new server ID. */
-               _srv_parse_set_id_from_prefix(newsrv, srv->tmpl_info.prefix, i);
+               newsrv->id = server_set_id_from_prefix(srv->tmpl_info.prefix, i);
+               if (!newsrv->id) {
+                       ha_alert("out of memory");
+                       err_code = ERR_ALERT | ERR_ABORT;
+                       goto out;
+               }
 
                cebis_item_insert(&curproxy->conf.used_server_name, conf.name_node, id, newsrv);
        }