mod_erlang_event: Support for reading erlang cookie from a file

mod_erlang_event will now try to read $HOME/.erlang.cookie if no cookie
is specified in the config file. You can specify an arbitary cookie file
via the 'cookie-file' parameter in the config file. The cookie file MUST
be readable by the user freeswitch is running as (either the owner or
root) and the file MUST NOT be readable/writeable/executable by any
other user (eg 0400 permissions). Thanks to James Aimonetti for the idea
and the original patch.

diff --git a/src/mod/event_handlers/mod_erlang_event/mod_erlang_event.c b/src/mod/event_handlers/mod_erlang_event/mod_erlang_event.c
index 848a2c58ea1ccdeee45adc51b0feafef83a15e85..f2a20f34c9cdee95bcb9a63a3ac6ce991a9160cc 100644 (file)
--- a/src/mod/event_handlers/mod_erlang_event/mod_erlang_event.c
+++ b/src/mod/event_handlers/mod_erlang_event/mod_erlang_event.c
@@ -1015,6 +1015,53 @@ static void launch_listener_thread(listener_t *listener)
 
 }
 
+static int read_cookie_from_file(char *filename) {
+       int fd;
+       char cookie[MAXATOMLEN+1];
+       char *end;
+       struct stat buf;
+       ssize_t res;
+
+       if (!stat(filename, &buf)) {
+               if ((buf.st_mode & S_IRWXG) || (buf.st_mode & S_IRWXO)) {
+                       switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "%s must only be accessible by owner only.\n", filename);
+                       return 2;
+               }
+               if (buf.st_size > MAXATOMLEN) {
+                       switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "%s contains a cookie larger than the maximum atom size of %d.\n", filename, MAXATOMLEN);
+                       return 2;
+               }
+               fd = open(filename, O_RDONLY);
+               if (fd < 1) {
+                       switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Unable to open cookie file %s : %d.\n", filename, errno);
+                       return 2;
+               }
+
+               if ((res = read(fd, cookie, MAXATOMLEN)) < 1) {
+                       switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Unable to read cookie file %s : %d.\n", filename, errno);
+               }
+
+               cookie[MAXATOMLEN+1] = '\0';
+
+               /* replace any end of line characters with a null */
+               if ((end = strchr(cookie, '\n'))) {
+                       *end = '\0';
+               }
+
+               if ((end = strchr(cookie, '\r'))) {
+                       *end = '\0';
+               }
+
+               switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Read %d bytes from cookie file %s.\n", (int)res, filename);
+
+               set_pref_cookie(cookie);
+               return 0;
+       } else {
+               /* don't error here, because we might be blindly trying to read $HOME/.erlang.cookie, and that can fail silently */
+               return 1;
+       }
+}
+
 
 static int config(void)
 {
@@ -1041,6 +1088,10 @@ static int config(void)
                                        prefs.port = (uint16_t) atoi(val);
                                } else if (!strcmp(var, "cookie")) {
                                        set_pref_cookie(val);
+                               } else if (!strcmp(var, "cookie-file")) {
+                                       if (read_cookie_from_file(val) == 1) {
+                                               switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Unable to read cookie from %s\n", val);
+                                       }
                                } else if (!strcmp(var, "nodename")) {
                                        set_pref_nodename(val);
                                } else if (!strcmp(var, "compat-rel")) {
@@ -1075,7 +1126,21 @@ static int config(void)
        }
 
        if (zstr(prefs.cookie)) {
-               set_pref_cookie("ClueCon");
+               int res;
+               char* home_dir = getenv("HOME");
+               char path_buf[1024];
+
+               if (!zstr(home_dir)) {
+                       /* $HOME/.erlang.cookie */
+                       switch_snprintf(path_buf, sizeof(path_buf), "%s%s%s", home_dir, SWITCH_PATH_SEPARATOR, ".erlang.cookie");
+                       switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Checking for cookie at path: %s\n", path_buf);
+
+                       res = read_cookie_from_file(path_buf);
+                       if (res) {
+                               switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, "No cookie or valid cookie file specified, using default cookie\n");
+                               set_pref_cookie("ClueCon");
+                       }
+               }
        }
 
        if (!prefs.port) {