[sr-dev] Permission problem and setuid in Kamailio 1.5

Hi all, There is a permission problem if the daemon is started given -u and -g parameters (sets up user and group for the process). The do_suid function (defined in demonize.c) is called after the call to init_modules(), so the mod_init functions of the configured module are loaded before the call to do_suid. This wasn't a problem in 1.3 because no module(I am aware off) use the uid and gid of the process to do permission checks. This has changed in 1.5, module carrierroute, as there is a check to see if the route file in config-file mode (usually /etc/kamailio/carrierroute.conf) has the right permission set on it (Issues an warning if it's worldly writable and error if it's not writable by the process owner). This of course is a problem because kamailio hasn't yet setuid()/setgid() so the checks are done using the wrong uid. A correct (imho) course of action is to move the call to do_suid function before the call to init_modules()(and before any other calls to initialization functions). I've attached a small patch that does this (tested). There are any considerations on why the init_modules() should be called with another uid/gid? Greetings, Marius Index: main.c =================================================================== --- main.c (revision 5937) +++ main.c (working copy) @@ -656,10 +656,6 @@ LM_WARN("using only the first listen address (no fork)\n"); } - /* try to drop privileges */ - if (do_suid(uid, gid)==-1) - goto error; - /* we need another process to act as the timer*/ if (start_timer_processes()!=0) { LM_CRIT("cannot start timer process(es)\n"); @@ -752,7 +748,6 @@ /* all processes should have access to all the sockets (for sending) * so we open all first*/ - if (do_suid(uid, gid)==-1) goto error; /* try to drop privileges */ /* udp processes */ for(si=udp_listen; si; si=si->next){ @@ -1278,6 +1273,12 @@ LM_INFO("no private memory pool configured, processes use system memory\n"); #endif + /* Set uid/gid */ + if (do_suid(uid, gid)==-1){ + LM_ERR("failed to drop privileges"); + goto error; /* try to drop privileges */ + } + /* Init statistics */ if (init_stats_collector()<0) { LM_ERR("failed to initialize statistics\n"); @@ -1330,3 +1331,4 @@ cleanup(0); return ret; } +