chan_pjsip: Don't assume a session will have a channel.

When querying for PJSIP specific information using the dialplan
function CHANNEL() it is possible that the underlying session
will no longer have a channel associated with it. This is
most likely to occur when the RTCP HEP module attempts to get
the channel name. If this happens then a crash will occur.

This change just adds a check that the channel exists on the
session before querying it.

ASTERISK-26857

Change-Id: I113479cffff6ae64cf8ed089e9e1565223426f01

diff --git a/channels/pjsip/dialplan_functions.c b/channels/pjsip/dialplan_functions.c
index 719a0747c204fec72cb3740aa9aace192f3b7977..652a6b7f380465c17d31dbe1e410e4543c81cc50 100644 (file)
--- a/channels/pjsip/dialplan_functions.c
+++ b/channels/pjsip/dialplan_functions.c
@@ -737,17 +737,27 @@ static int read_pjsip(void *data)
        struct pjsip_func_args *func_args = data;
 
        if (!strcmp(func_args->param, "rtp")) {
+               if (!func_args->session->channel) {
+                       func_args->ret = -1;
+                       return 0;
+               }
                func_args->ret = channel_read_rtp(func_args->session->channel, func_args->type,
                                                  func_args->field, func_args->buf,
                                                  func_args->len);
        } else if (!strcmp(func_args->param, "rtcp")) {
+               if (!func_args->session->channel) {
+                       func_args->ret = -1;
+                       return 0;
+               }
                func_args->ret = channel_read_rtcp(func_args->session->channel, func_args->type,
                                                   func_args->field, func_args->buf,
                                                   func_args->len);
        } else if (!strcmp(func_args->param, "endpoint")) {
                if (!func_args->session->endpoint) {
-                       ast_log(AST_LOG_WARNING, "Channel %s has no endpoint!\n", ast_channel_name(func_args->session->channel));
-                       return -1;
+                       ast_log(AST_LOG_WARNING, "Channel %s has no endpoint!\n", func_args->session->channel ?
+                               ast_channel_name(func_args->session->channel) : "<unknown>");
+                       func_args->ret = -1;
+                       return 0;
                }
                snprintf(func_args->buf, func_args->len, "%s", ast_sorcery_object_get_id(func_args->session->endpoint));
        } else if (!strcmp(func_args->param, "contact")) {
@@ -761,6 +771,10 @@ static int read_pjsip(void *data)
                }
                snprintf(func_args->buf, func_args->len, "%s", ast_sorcery_object_get_id(func_args->session->aor));
        } else if (!strcmp(func_args->param, "pjsip")) {
+               if (!func_args->session->channel) {
+                       func_args->ret = -1;
+                       return 0;
+               }
                func_args->ret = channel_read_pjsip(func_args->session->channel, func_args->type,
                                                    func_args->field, func_args->buf,
                                                    func_args->len);