Hello Harald Welte, Jenkins Builder,

I'd like you to reexamine a change.  Please visit

    https://gerrit.osmocom.org/4006

to look at the new patch set (#6).

sdp: refactoring sdp parser/generator

move SDP generator function write_response_sdp() from mgcp_protocol.c
to mgcp_sdp.c

move prototypes for mgcp_parse_sdp_data() and mgcp_set_audio_info()
to mgcp_sdp.h

change parameter list of mgcp_parse_sdp_data() so that it takes the
rtp conn directly, rather than struct mgcp_rtp_end.

fix sourcecode formatting in mgcp_sdp.c

add doxygen comments to all public functions

Change-Id: I9f88c93872ff913bc211f560b26901267f577324
---
M include/osmocom/mgcp/Makefile.am
M include/osmocom/mgcp/mgcp_internal.h
A include/osmocom/mgcp/mgcp_sdp.h
M src/libosmo-mgcp/mgcp_protocol.c
M src/libosmo-mgcp/mgcp_sdp.c
5 files changed, 211 insertions(+), 142 deletions(-)


  git pull ssh://gerrit.osmocom.org:29418/osmo-mgw refs/changes/06/4006/6

diff --git a/include/osmocom/mgcp/Makefile.am b/include/osmocom/mgcp/Makefile.am
index 646b887..cd8f599 100644
--- a/include/osmocom/mgcp/Makefile.am
+++ b/include/osmocom/mgcp/Makefile.am
@@ -4,4 +4,5 @@
        mgcp_conn.h \
        mgcp_stat.h \
        mgcp_ep.h \
+       mgcp_sdp.h \
        $(NULL)
diff --git a/include/osmocom/mgcp/mgcp_internal.h 
b/include/osmocom/mgcp/mgcp_internal.h
index 3a22d51..777d787 100644
--- a/include/osmocom/mgcp/mgcp_internal.h
+++ b/include/osmocom/mgcp/mgcp_internal.h
@@ -317,9 +317,6 @@
 #define DEFAULT_RTP_AUDIO_DEFAULT_CHANNELS 1
 
 #define PTYPE_UNDEFINED (-1)
-int mgcp_parse_sdp_data(struct mgcp_endpoint *endp, struct mgcp_rtp_end *rtp, 
struct mgcp_parse_data *p);
-int mgcp_set_audio_info(void *ctx, struct mgcp_rtp_codec *codec,
-                       int payload_type, const char *audio_name);
 
 /*! get the ip-address where the mgw application is bound on.
  *  \param[in] endp mgcp endpoint, that holds a copy of the VTY parameters
diff --git a/include/osmocom/mgcp/mgcp_sdp.h b/include/osmocom/mgcp/mgcp_sdp.h
new file mode 100644
index 0000000..0eb376d
--- /dev/null
+++ b/include/osmocom/mgcp/mgcp_sdp.h
@@ -0,0 +1,33 @@
+/*
+ * SDP generation and parsing
+ *
+ * (C) 2009-2015 by Holger Hans Peter Freyther <[email protected]>
+ * (C) 2009-2014 by On-Waves
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#pragma once
+
+int mgcp_parse_sdp_data(struct mgcp_endpoint *endp, struct mgcp_conn_rtp *conn,
+                       struct mgcp_parse_data *p);
+
+int mgcp_set_audio_info(void *ctx, struct mgcp_rtp_codec *codec,
+                       int payload_type, const char *audio_name);
+
+int mgcp_write_response_sdp(struct mgcp_endpoint *endp,
+                           struct mgcp_conn_rtp *conn, char *sdp_record,
+                           size_t size, const char *addr);
diff --git a/src/libosmo-mgcp/mgcp_protocol.c b/src/libosmo-mgcp/mgcp_protocol.c
index ac25894..5d4dd47 100644
--- a/src/libosmo-mgcp/mgcp_protocol.c
+++ b/src/libosmo-mgcp/mgcp_protocol.c
@@ -38,6 +38,7 @@
 #include <osmocom/mgcp/mgcp_stat.h>
 #include <osmocom/mgcp/mgcp_msg.h>
 #include <osmocom/mgcp/mgcp_ep.h>
+#include <osmocom/mgcp/mgcp_sdp.h>
 
 struct mgcp_request {
        char *name;
@@ -190,80 +191,6 @@
        return create_resp(endp, code, " FAIL", msg, trans, NULL, NULL);
 }
 
-static int write_response_sdp(struct mgcp_endpoint *endp,
-                             struct mgcp_conn_rtp *conn,
-                             char *sdp_record, size_t size, const char *addr)
-{
-       const char *fmtp_extra;
-       const char *audio_name;
-       int payload_type;
-       int len;
-       int nchars;
-
-       if (!conn)
-               return -1;
-
-       endp->cfg->get_net_downlink_format_cb(endp, &payload_type,
-                                             &audio_name, &fmtp_extra, conn);
-
-       len = snprintf(sdp_record, size,
-                      "v=0\r\n"
-                      "o=- %u 23 IN IP4 %s\r\n"
-                      "s=-\r\n"
-                      "c=IN IP4 %s\r\n"
-                      "t=0 0\r\n", conn->conn->id, addr, addr);
-
-       if (len < 0 || len >= size)
-               goto buffer_too_small;
-
-       if (payload_type >= 0) {
-               nchars = snprintf(sdp_record + len, size - len,
-                                 "m=audio %d RTP/AVP %d\r\n",
-                                 conn->end.local_port, payload_type);
-               if (nchars < 0 || nchars >= size - len)
-                       goto buffer_too_small;
-
-               len += nchars;
-
-               if (audio_name && endp->tcfg->audio_send_name) {
-                       nchars = snprintf(sdp_record + len, size - len,
-                                         "a=rtpmap:%d %s\r\n",
-                                         payload_type, audio_name);
-
-                       if (nchars < 0 || nchars >= size - len)
-                               goto buffer_too_small;
-
-                       len += nchars;
-               }
-
-               if (fmtp_extra) {
-                       nchars = snprintf(sdp_record + len, size - len,
-                                         "%s\r\n", fmtp_extra);
-
-                       if (nchars < 0 || nchars >= size - len)
-                               goto buffer_too_small;
-
-                       len += nchars;
-               }
-       }
-       if (conn->end.packet_duration_ms > 0 && endp->tcfg->audio_send_ptime) {
-               nchars = snprintf(sdp_record + len, size - len,
-                                 "a=ptime:%u\r\n",
-                                 conn->end.packet_duration_ms);
-               if (nchars < 0 || nchars >= size - len)
-                       goto buffer_too_small;
-
-               len += nchars;
-       }
-
-       return len;
-
-buffer_too_small:
-       LOGP(DLMGCP, LOGL_ERROR, "SDP buffer too small: %zu (needed %d)\n",
-            size, len);
-       return -1;
-}
-
 /* Format MGCP response string (with SDP attached) */
 static struct msgb *create_response_with_sdp(struct mgcp_endpoint *endp,
                                             struct mgcp_conn_rtp *conn,
@@ -291,8 +218,8 @@
        if (len < 0)
                return NULL;
 
-       nchars = write_response_sdp(endp, conn, sdp_record + len,
-                                   sizeof(sdp_record) - len - 1, addr);
+       nchars = mgcp_write_response_sdp(endp, conn, sdp_record + len,
+                                        sizeof(sdp_record) - len - 1, addr);
        if (nchars < 0)
                return NULL;
 
@@ -688,7 +615,7 @@
 
        /* set up RTP media parameters */
        if (have_sdp)
-               mgcp_parse_sdp_data(endp, &conn->end, p);
+               mgcp_parse_sdp_data(endp, conn, p);
        else if (endp->local_options.codec)
                mgcp_set_audio_info(p->cfg, &conn->end.codec,
                                    PTYPE_UNDEFINED, endp->local_options.codec);
@@ -835,7 +762,7 @@
                        conn->conn->mode = conn->conn->mode_orig;
 
        if (have_sdp)
-               mgcp_parse_sdp_data(endp, &conn->end, p);
+               mgcp_parse_sdp_data(endp, conn, p);
 
        set_local_cx_options(endp->tcfg->endpoints, &endp->local_options,
                             local_options);
diff --git a/src/libosmo-mgcp/mgcp_sdp.c b/src/libosmo-mgcp/mgcp_sdp.c
index 7568351..048a533 100644
--- a/src/libosmo-mgcp/mgcp_sdp.c
+++ b/src/libosmo-mgcp/mgcp_sdp.c
@@ -38,6 +38,12 @@
        int channels;
 };
 
+/*! set codec configuration depending on payload type and codec name.
+ *  \endp[in] ctx talloc context
+ *  \endp[out] codec configuration (caller provided memory)
+ *  \endp[in] payload_type codec type id (e.g. 3 for GSM, -1 when undefined)
+ *  \endp[in] audio_name audio codec name (e.g. "GSM/8000/1")
+ *  \returns 0 on success, -1 on failure */
 int mgcp_set_audio_info(void *ctx, struct mgcp_rtp_codec *codec,
                        int payload_type, const char *audio_name)
 {
@@ -55,15 +61,23 @@
 
        if (!audio_name) {
                switch (payload_type) {
-               case 0: audio_name = "PCMU/8000/1"; break;
-               case 3: audio_name = "GSM/8000/1"; break;
-               case 8: audio_name = "PCMA/8000/1"; break;
-               case 18: audio_name = "G729/8000/1"; break;
+               case 0:
+                       audio_name = "PCMU/8000/1";
+                       break;
+               case 3:
+                       audio_name = "GSM/8000/1";
+                       break;
+               case 8:
+                       audio_name = "PCMA/8000/1";
+                       break;
+               case 18:
+                       audio_name = "G729/8000/1";
+                       break;
                default:
-                        /* Payload type is unknown, don't change rate and
-                         * channels. */
-                        /* TODO: return value? */
-                        return 0;
+                       /* Payload type is unknown, don't change rate and
+                        * channels. */
+                       /* TODO: return value? */
+                       return 0;
                }
        }
 
@@ -107,7 +121,7 @@
        return 0;
 }
 
-void codecs_initialize(void *ctx, struct sdp_rtp_map *codecs, int used)
+static void codecs_initialize(void *ctx, struct sdp_rtp_map *codecs, int used)
 {
        int i;
 
@@ -137,7 +151,8 @@
        }
 }
 
-void codecs_update(void *ctx, struct sdp_rtp_map *codecs, int used, int 
payload, char *audio_name)
+static void codecs_update(void *ctx, struct sdp_rtp_map *codecs, int used,
+                         int payload, char *audio_name)
 {
        int i;
 
@@ -148,8 +163,9 @@
                if (codecs[i].payload_type != payload)
                        continue;
                if (sscanf(audio_name, "%63[^/]/%d/%d",
-                               audio_codec, &rate, &channels) < 1) {
-                       LOGP(DLMGCP, LOGL_ERROR, "Failed to parse '%s'\n", 
audio_name);
+                          audio_codec, &rate, &channels) < 1) {
+                       LOGP(DLMGCP, LOGL_ERROR, "Failed to parse '%s'\n",
+                            audio_name);
                        continue;
                }
 
@@ -160,29 +176,36 @@
                return;
        }
 
-       LOGP(DLMGCP, LOGL_ERROR, "Unconfigured PT(%d) with %s\n", payload, 
audio_name);
+       LOGP(DLMGCP, LOGL_ERROR, "Unconfigured PT(%d) with %s\n", payload,
+            audio_name);
 }
 
-int is_codec_compatible(struct mgcp_endpoint *endp, struct sdp_rtp_map *codec)
+/* Check if the codec matches what is set up in the trunk config */
+static int is_codec_compatible(struct mgcp_endpoint *endp,
+                              struct sdp_rtp_map *codec)
 {
-       char *bts_codec;
+       char *codec_str;
        char audio_codec[64];
 
        if (!codec->codec_name)
                return 0;
 
-       /*
-        * GSM, GSM/8000 and GSM/8000/1 should all be compatible.. let's go
-        * by name first.
-        */
-       bts_codec = endp->tcfg->audio_name;
-       if (sscanf(bts_codec, "%63[^/]/%*d/%*d", audio_codec) < 1)
+       /* GSM, GSM/8000 and GSM/8000/1 should all be compatible...
+        * let's go by name first. */
+       codec_str = endp->tcfg->audio_name;
+       if (sscanf(codec_str, "%63[^/]/%*d/%*d", audio_codec) < 1)
                return 0;
 
        return strcasecmp(audio_codec, codec->codec_name) == 0;
 }
 
-int mgcp_parse_sdp_data(struct mgcp_endpoint *endp, struct mgcp_rtp_end *rtp, 
struct mgcp_parse_data *p)
+/*! analyze SDP input string.
+ *  \endp[in] endp trunk endpoint
+ *  \endp[in] conn associated rtp connection
+ *  \endp[in] caller provided memory to store the parsing results
+ *  \returns 0 on success, -1 on failure */
+int mgcp_parse_sdp_data(struct mgcp_endpoint *endp, struct mgcp_conn_rtp *conn,
+                       struct mgcp_parse_data *p)
 {
        struct sdp_rtp_map codecs[10];
        int codecs_used = 0;
@@ -191,7 +214,19 @@
        int i;
        int codecs_assigned = 0;
        void *tmp_ctx = talloc_new(NULL);
+       struct mgcp_rtp_end *rtp;
 
+       int payload;
+       int ptime, ptime2 = 0;
+       char audio_name[64];
+       int port, rc;
+       char ipv4[16];
+
+       OSMO_ASSERT(endp);
+       OSMO_ASSERT(conn);
+       OSMO_ASSERT(p);
+
+       rtp = &conn->end;
        memset(&codecs, 0, sizeof(codecs));
 
        for_each_line(line, p->save) {
@@ -202,41 +237,36 @@
                case 'v':
                        /* skip these SDP attributes */
                        break;
-               case 'a': {
-                       int payload;
-                       int ptime, ptime2 = 0;
-                       char audio_name[64];
-
-
+               case 'a':
                        if (sscanf(line, "a=rtpmap:%d %63s",
                                   &payload, audio_name) == 2) {
-                               codecs_update(tmp_ctx, codecs, codecs_used, 
payload, audio_name);
-                       } else if (sscanf(line, "a=ptime:%d-%d",
-                                         &ptime, &ptime2) >= 1) {
+                               codecs_update(tmp_ctx, codecs,
+                                             codecs_used, payload, audio_name);
+                       } else
+                           if (sscanf
+                               (line, "a=ptime:%d-%d", &ptime, &ptime2) >= 1) {
                                if (ptime2 > 0 && ptime2 != ptime)
                                        rtp->packet_duration_ms = 0;
                                else
                                        rtp->packet_duration_ms = ptime;
-                       } else if (sscanf(line, "a=maxptime:%d", &ptime2) == 1) 
{
+                       } else if (sscanf(line, "a=maxptime:%d", &ptime2)
+                                  == 1) {
                                maxptime = ptime2;
                        }
                        break;
-               }
-               case 'm': {
-                       int port, rc;
-
-                       rc = sscanf(line, "m=audio %d RTP/AVP %d %d %d %d %d %d 
%d %d %d %d",
-                                       &port,
-                                       &codecs[0].payload_type,
-                                       &codecs[1].payload_type,
-                                       &codecs[2].payload_type,
-                                       &codecs[3].payload_type,
-                                       &codecs[4].payload_type,
-                                       &codecs[5].payload_type,
-                                       &codecs[6].payload_type,
-                                       &codecs[7].payload_type,
-                                       &codecs[8].payload_type,
-                                       &codecs[9].payload_type);
+               case 'm':
+                       rc = sscanf(line,
+                                   "m=audio %d RTP/AVP %d %d %d %d %d %d %d %d 
%d %d",
+                                   &port, &codecs[0].payload_type,
+                                   &codecs[1].payload_type,
+                                   &codecs[2].payload_type,
+                                   &codecs[3].payload_type,
+                                   &codecs[4].payload_type,
+                                   &codecs[5].payload_type,
+                                   &codecs[6].payload_type,
+                                   &codecs[7].payload_type,
+                                   &codecs[8].payload_type,
+                                   &codecs[9].payload_type);
                        if (rc >= 2) {
                                rtp->rtp_port = htons(port);
                                rtp->rtcp_port = htons(port + 1);
@@ -244,20 +274,18 @@
                                codecs_initialize(tmp_ctx, codecs, codecs_used);
                        }
                        break;
-               }
-               case 'c': {
-                       char ipv4[16];
+               case 'c':
 
                        if (sscanf(line, "c=IN IP4 %15s", ipv4) == 1) {
                                inet_aton(ipv4, &rtp->addr);
                        }
                        break;
-               }
                default:
                        if (p->endp)
                                LOGP(DLMGCP, LOGL_NOTICE,
                                     "Unhandled SDP option: '%c'/%d on 0x%x\n",
-                                    line[0], line[0], 
ENDPOINT_NUMBER(p->endp));
+                                    line[0], line[0],
+                                    ENDPOINT_NUMBER(p->endp));
                        else
                                LOGP(DLMGCP, LOGL_NOTICE,
                                     "Unhandled SDP option: '%c'/%d\n",
@@ -269,25 +297,24 @@
        /* Now select the primary and alt_codec */
        for (i = 0; i < codecs_used && codecs_assigned < 2; ++i) {
                struct mgcp_rtp_codec *codec = codecs_assigned == 0 ?
-                                       &rtp->codec : &rtp->alt_codec;
+                   &rtp->codec : &rtp->alt_codec;
 
                if (endp->tcfg->no_audio_transcoding &&
-                       !is_codec_compatible(endp, &codecs[i])) {
+                   !is_codec_compatible(endp, &codecs[i])) {
                        LOGP(DLMGCP, LOGL_NOTICE, "Skipping codec %s\n",
-                               codecs[i].codec_name);
+                            codecs[i].codec_name);
                        continue;
                }
 
                mgcp_set_audio_info(p->cfg, codec,
-                                       codecs[i].payload_type,
-                                       codecs[i].map_line);
+                                   codecs[i].payload_type, codecs[i].map_line);
                codecs_assigned += 1;
        }
 
        if (codecs_assigned > 0) {
                /* TODO/XXX: Store this per codec and derive it on use */
                if (maxptime >= 0 && maxptime * rtp->codec.frame_duration_den >
-                               rtp->codec.frame_duration_num * 1500) {
+                   rtp->codec.frame_duration_num * 1500) {
                        /* more than 1 frame */
                        rtp->packet_duration_ms = 0;
                }
@@ -296,11 +323,95 @@
                     "Got media info via SDP: port %d, payload %d (%s), "
                     "duration %d, addr %s\n",
                     ntohs(rtp->rtp_port), rtp->codec.payload_type,
-                    rtp->codec.subtype_name ? rtp->codec.subtype_name : 
"unknown",
-                    rtp->packet_duration_ms, inet_ntoa(rtp->addr));
+                    rtp->codec.subtype_name ? rtp->
+                    codec.subtype_name : "unknown", rtp->packet_duration_ms,
+                    inet_ntoa(rtp->addr));
        }
 
        talloc_free(tmp_ctx);
        return codecs_assigned > 0;
 }
 
+/*! generate SDP response string.
+ *  \endp[in] endp trunk endpoint
+ *  \endp[in] conn associated rtp connection
+ *  \endp[out] sdp_record resulting SDP string
+ *  \endp[in] size buffer size of sdp_record
+ *  \endp[in] addr IPV4 address string (e.g. 192.168.100.1)
+ *  \returns 0 on success, -1 on failure */
+int mgcp_write_response_sdp(struct mgcp_endpoint *endp,
+                           struct mgcp_conn_rtp *conn, char *sdp_record,
+                           size_t size, const char *addr)
+{
+       const char *fmtp_extra;
+       const char *audio_name;
+       int payload_type;
+       int len;
+       int nchars;
+
+       OSMO_ASSERT(endp);
+       OSMO_ASSERT(conn);
+       OSMO_ASSERT(sdp_record);
+       OSMO_ASSERT(size > 0);
+       OSMO_ASSERT(addr);
+
+       endp->cfg->get_net_downlink_format_cb(endp, &payload_type,
+                                             &audio_name, &fmtp_extra, conn);
+
+       len = snprintf(sdp_record, size,
+                      "v=0\r\n"
+                      "o=- %u 23 IN IP4 %s\r\n"
+                      "s=-\r\n"
+                      "c=IN IP4 %s\r\n"
+                      "t=0 0\r\n", conn->conn->id, addr, addr);
+
+       if (len < 0 || len >= size)
+               goto buffer_too_small;
+
+       if (payload_type >= 0) {
+               nchars = snprintf(sdp_record + len, size - len,
+                                 "m=audio %d RTP/AVP %d\r\n",
+                                 conn->end.local_port, payload_type);
+               if (nchars < 0 || nchars >= size - len)
+                       goto buffer_too_small;
+
+               len += nchars;
+
+               if (audio_name && endp->tcfg->audio_send_name) {
+                       nchars = snprintf(sdp_record + len, size - len,
+                                         "a=rtpmap:%d %s\r\n",
+                                         payload_type, audio_name);
+
+                       if (nchars < 0 || nchars >= size - len)
+                               goto buffer_too_small;
+
+                       len += nchars;
+               }
+
+               if (fmtp_extra) {
+                       nchars = snprintf(sdp_record + len, size - len,
+                                         "%s\r\n", fmtp_extra);
+
+                       if (nchars < 0 || nchars >= size - len)
+                               goto buffer_too_small;
+
+                       len += nchars;
+               }
+       }
+       if (conn->end.packet_duration_ms > 0 && endp->tcfg->audio_send_ptime) {
+               nchars = snprintf(sdp_record + len, size - len,
+                                 "a=ptime:%u\r\n",
+                                 conn->end.packet_duration_ms);
+               if (nchars < 0 || nchars >= size - len)
+                       goto buffer_too_small;
+
+               len += nchars;
+       }
+
+       return len;
+
+buffer_too_small:
+       LOGP(DLMGCP, LOGL_ERROR, "SDP buffer too small: %zu (needed %d)\n",
+            size, len);
+       return -1;
+}

-- 
To view, visit https://gerrit.osmocom.org/4006
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Gerrit-MessageType: newpatchset
Gerrit-Change-Id: I9f88c93872ff913bc211f560b26901267f577324
Gerrit-PatchSet: 6
Gerrit-Project: osmo-mgw
Gerrit-Branch: master
Gerrit-Owner: Neels Hofmeyr <[email protected]>
Gerrit-Reviewer: Harald Welte <[email protected]>
Gerrit-Reviewer: Jenkins Builder
Gerrit-Reviewer: dexter <[email protected]>

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