pjsip: fix support for allow=all

This change adds improvements to support for allow=all in
pjsip.conf so that it functions as intended.  Previously,
the allow/disallow socery configuration would set & clear
codecs from the media.codecs and media.prefs list, but if
all was specified the prefs list was not updated.  Then a
call would fail when create_outgoing_sdp_stream() created
an SDP with no audio codecs.

A new function ast_codec_pref_append_all() is provided to
add all codecs to the prefs list - only those not already
on the list.  This enables the configuration to specify a
codec preference, but still add all codecs, and even then
remove some codecs, as shown in this example:

allow = ulaw, alaw, all, !g729, !g723

Also, the display order of allow in cli output is updated
to match the configuration by using prefs instead of caps
when generating a human readable string.

Finally, a change to create_outgoing_sdp_stream() skips a
codec when it does not have a payload code instead of the
call failing.

(closes issue ASTERISK-23018)
Reported by: xrobau
Review: https://reviewboard.asterisk.org/r/3131/
........

Merged revisions 405875 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@405876 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 36 insertions, 0 deletions

diff --git a/main/format_pref.c b/main/format_pref.c
index 4ea9f0cc7..b96184a08 100644
--- a/main/format_pref.c
+++ b/main/format_pref.c
@@ -143,6 +143,42 @@ void ast_codec_pref_remove(struct ast_codec_pref *pref, struct ast_format *forma
 	ast_format_list_destroy(f_list);
 }
 
+/*! \brief Append all codecs to a preference list, without distrubing existing order */
+void ast_codec_pref_append_all(struct ast_codec_pref *pref)
+{
+	int x, y, found;
+	size_t f_len = 0;
+	const struct ast_format_list *f_list = ast_format_list_get(&f_len);
+
+	/* leave any existing entries, and don't create duplicates (e.g. allow=ulaw,all) */
+	for (x = 0; x < f_len; x++) {
+		/* x = codec to add */
+		found = 0;
+		for (y = 0; y < f_len; y++) {
+			/* y = scan of existing preferences */
+			if (!pref->order[y]) {
+				break;
+			}
+			if (x + 1 == pref->order[y]) {
+				found = 1;
+				break;
+			}
+		}
+		if (found) {
+			continue;
+		}
+		for (; y < f_len; y++) {
+			/* add x to the end of y */
+			if (!pref->order[y])
+			{
+				pref->order[y] = x + 1;
+				ast_format_copy(&pref->formats[y], &f_list[x].format);
+				break;
+			}
+		}
+	}
+}
+
 /*! \brief Append codec to list */
 int ast_codec_pref_append(struct ast_codec_pref *pref, struct ast_format *format)
 {