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osmo-sip-connector
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sdp.c FIXME 

Change-Id: Iea61d25827893208cbb5323809908477a3118a54
This commit is contained in:
Neels Hofmeyr 2019-10-22 03:39:55 +02:00
parent effead9835
commit 71fa54959c
4 changed files with 109 additions and 253 deletions
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2
src/call.c
View File

@ -179,6 +179,4 @@ void call_leg_update_sdp(struct call_leg *leg, const char *sdp)
if (!sdp || !*sdp)
return;
OSMO_STRLCPY_ARRAY(leg->sdp, sdp);
LOGP(DAPP, LOGL_NOTICE, "call(%u) leg(0x%p) received SDP: %s\n",
leg->call->id, leg, leg->sdp);
}

263
src/sdp.c
View File

@ -32,223 +32,86 @@
#include <string.h>
/*
* Check if the media mode attribute exists in SDP, in this
* case update the passed pointer with the media mode
*/
bool sdp_get_sdp_mode(const sip_t *sip, sdp_mode_t *mode) {
static const struct value_string sdp_mode_attr[] = {
{ SDP_MODE_UNSET, ""},
{ SDP_MODE_INACTIVE, "a=inactive\r\n"},
{ SDP_MODE_SENDRECV, "a=sendrecv\r\n"},
{ SDP_MODE_SENDONLY, "a=sendonly\r\n"},
{ SDP_MODE_RECVONLY, "a=recvonly\r\n"},
{}
};
const char *sdp_data;
sdp_parser_t *parser;
sdp_session_t *sdp;
const struct value_string sdp_mode_names[] = {
{ SDP_MODE_UNSET, "unset"},
{ SDP_MODE_INACTIVE, "inactive"},
{ SDP_MODE_SENDRECV, "sendrecv"},
{ SDP_MODE_SENDONLY, "sendonly"},
{ SDP_MODE_RECVONLY, "recvonly"},
{}
};
if (!sip->sip_payload || !sip->sip_payload->pl_data) {
LOGP(DSIP, LOGL_ERROR, "No SDP file\n");
return false;
}
sdp_data = sip->sip_payload->pl_data;
parser = sdp_parse(NULL, sdp_data, strlen(sdp_data), sdp_f_mode_0000);
if (!parser) {
LOGP(DSIP, LOGL_ERROR, "Failed to parse SDP\n");
return false;
}
sdp = sdp_session(parser);
if (!sdp) {
LOGP(DSIP, LOGL_ERROR, "No sdp session\n");
sdp_parser_free(parser);
return false;
}
if (!sdp->sdp_media || !sdp->sdp_media->m_mode) {
sdp_parser_free(parser);
return sdp_sendrecv;
}
sdp_parser_free(parser);
*mode = sdp->sdp_media->m_mode;
return true;
}
/*
* We want to decide on the audio codec later but we need to see
* if it is even including some of the supported ones.
*/
bool sdp_screen_sdp(const sip_t *sip)
/* Return location of a given SDP sendrecv mode attribute, if any. */
const char *sdp_find_mode(const char *sdp_str, enum sdp_mode mode)
{
const char *sdp_data;
sdp_parser_t *parser;
sdp_session_t *sdp;
sdp_media_t *media;
const char *found;
if (mode == SDP_MODE_UNSET)
return NULL;
if (!sip->sip_payload || !sip->sip_payload->pl_data) {
LOGP(DSIP, LOGL_ERROR, "No SDP file\n");
return false;
}
found = strstr(sdp_str, get_value_string(sdp_mode_attr, mode));
if (!found)
return NULL;
sdp_data = sip->sip_payload->pl_data;
parser = sdp_parse(NULL, sdp_data, strlen(sdp_data), 0);
if (!parser) {
LOGP(DSIP, LOGL_ERROR, "Failed to parse SDP\n");
return false;
}
/* At the start of the line? */
if (found > sdp_str && *(found-1) != '\n')
return NULL;
sdp = sdp_session(parser);
if (!sdp) {
LOGP(DSIP, LOGL_ERROR, "No sdp session\n");
sdp_parser_free(parser);
return false;
}
for (media = sdp->sdp_media; media; media = media->m_next) {
sdp_rtpmap_t *map;
if (media->m_proto != sdp_proto_rtp)
continue;
if (media->m_type != sdp_media_audio)
continue;
for (map = media->m_rtpmaps; map; map = map->rm_next) {
if (strcasecmp(map->rm_encoding, "GSM") == 0)
goto success;
if (strcasecmp(map->rm_encoding, "GSM-EFR") == 0)
goto success;
if (strcasecmp(map->rm_encoding, "GSM-HR-08") == 0)
goto success;
if (strcasecmp(map->rm_encoding, "AMR") == 0)
goto success;
}
}
sdp_parser_free(parser);
return false;
success:
sdp_parser_free(parser);
return true;
return found;
}
bool sdp_extract_sdp(struct sip_call_leg *leg, const sip_t *sip, bool any_codec)
/* Return the last SDP sendrecv mode attribute, or SDP_MODE_UNSET */
enum sdp_mode sdp_get_mode(const char *sdp_str, const char **found_at)
{
sdp_connection_t *conn;
sdp_session_t *sdp;
sdp_parser_t *parser;
sdp_media_t *media;
const char *sdp_data;
bool found_conn = false, found_map = false;
if (!sip->sip_payload || !sip->sip_payload->pl_data) {
LOGP(DSIP, LOGL_ERROR, "leg(%p) but no SDP file\n", leg);
return false;
}
sdp_data = sip->sip_payload->pl_data;
parser = sdp_parse(NULL, sdp_data, strlen(sdp_data), 0);
if (!parser) {
LOGP(DSIP, LOGL_ERROR, "leg(%p) failed to parse SDP\n",
leg);
return false;
}
sdp = sdp_session(parser);
if (!sdp) {
LOGP(DSIP, LOGL_ERROR, "leg(%p) no sdp session\n", leg);
sdp_parser_free(parser);
return false;
}
for (conn = sdp->sdp_connection; conn; conn = conn->c_next) {
struct in_addr addr;
if (conn->c_addrtype != sdp_addr_ip4)
const char *at = NULL;
enum sdp_mode mode = SDP_MODE_UNSET;
enum sdp_mode i;
for (i = 0; i < SDP_MODES_COUNT; i++) {
const char *found = sdp_find_mode(sdp_str, i);
if (!found)
continue;
inet_aton(conn->c_address, &addr);
leg->base.ip = addr.s_addr;
found_conn = true;
break;
}
for (media = sdp->sdp_media; media; media = media->m_next) {
sdp_rtpmap_t *map;
if (media->m_proto != sdp_proto_rtp)
/* If more than one sendrecv attrib are in the SDP string, let the last one win */
if (at > found)
continue;
if (media->m_type != sdp_media_audio)
continue;
for (map = media->m_rtpmaps; map; map = map->rm_next) {
if (!any_codec && strcasecmp(map->rm_encoding, leg->wanted_codec) != 0)
continue;
leg->base.port = media->m_port;
leg->base.payload_type = map->rm_pt;
found_map = true;
break;
}
if (found_map)
break;
at = found;
mode = i;
}
if (!found_conn || !found_map) {
LOGP(DSIP, LOGL_ERROR, "leg(%p) did not find %d/%d\n",
leg, found_conn, found_map);
sdp_parser_free(parser);
return false;
}
sdp_parser_free(parser);
return true;
if (found_at)
*found_at = at;
return mode;
}
char *sdp_create_file(struct sip_call_leg *leg, struct call_leg *other, sdp_mode_t mode)
/* Remove all pre-existing occurences of an SDP mode attribute, and then add the given mode attribute (if not
* SDP_MODE_UNSET). Allocate the resulting string from ctx (talloc). */
char *sdp_copy_and_set_mode(void *ctx, const char *sdp_str, enum sdp_mode mode)
{
struct in_addr net = { .s_addr = other->ip };
char *fmtp_str = NULL, *sdp;
char *mode_attribute;
char ip_addr[INET_ADDRSTRLEN];
char *removed = talloc_strdup(ctx, sdp_str);
char *added;
char *found_at;
inet_ntop(AF_INET, &net, ip_addr, sizeof(ip_addr));
leg->wanted_codec = app_media_name(other->payload_msg_type);
if (strcmp(leg->wanted_codec, "AMR") == 0)
fmtp_str = talloc_asprintf(leg, "a=fmtp:%d octet-align=1\r\n", other->payload_type);
switch (mode) {
case sdp_inactive:
mode_attribute = "a=inactive\r\n";
break;
case sdp_sendrecv:
mode_attribute = "a=sendrecv\r\n";
break;
case sdp_sendonly:
mode_attribute = "a=sendonly\r\n";
break;
case sdp_recvonly:
mode_attribute = "a=recvonly\r\n";
break;
default:
OSMO_ASSERT(false);
break;
/* Remove */
while (sdp_get_mode(removed, (const char**)&found_at) != SDP_MODE_UNSET) {
char *next_line = strchr(found_at, '\n');
if (!next_line)
*found_at = '\0';
else
strcpy(found_at, next_line);
}
sdp = talloc_asprintf(leg,
"v=0\r\n"
"o=Osmocom 0 0 IN IP4 %s\r\n"
"s=GSM Call\r\n"
"c=IN IP4 %s\r\n"
"t=0 0\r\n"
"m=audio %d RTP/AVP %d\r\n"
"%s"
"a=rtpmap:%d %s/8000\r\n"
"%s",
ip_addr, ip_addr,
other->port, other->payload_type,
fmtp_str ? fmtp_str : "",
other->payload_type,
leg->wanted_codec,
mode_attribute);
talloc_free(fmtp_str);
return sdp;
/* Add */
if (mode == SDP_MODE_UNSET)
return removed;
added = talloc_asprintf(ctx, "%s%s", removed, get_value_string(sdp_mode_attr, mode));
talloc_free(removed);
return added;
}

25
src/sdp.h
View File

@ -1,15 +1,20 @@
#pragma once
#include <sofia-sip/sip.h>
#include <sofia-sip/sdp.h>
#include <osmocom/core/utils.h>
#include <stdbool.h>
enum sdp_mode {
SDP_MODE_UNSET = 0,
SDP_MODE_INACTIVE,
SDP_MODE_SENDRECV,
SDP_MODE_SENDONLY,
SDP_MODE_RECVONLY,
SDP_MODES_COUNT,
};
struct sip_call_leg;
struct call_leg;
extern const struct value_string sdp_mode_names[];
static inline const char *sdp_mode_name(enum sdp_mode mode)
{ return get_value_string(sdp_mode_names, mode); }
bool sdp_get_sdp_mode(const sip_t *sip, sdp_mode_t *mode);
bool sdp_screen_sdp(const sip_t *sip);
bool sdp_extract_sdp(struct sip_call_leg *leg, const sip_t *sip, bool any_codec);
char *sdp_create_file(struct sip_call_leg *, struct call_leg *, sdp_mode_t mode);
const char *sdp_find_mode(const char *sdp_str, enum sdp_mode mode);
enum sdp_mode sdp_get_mode(const char *sdp_str, const char **found_at);
char *sdp_copy_and_set_mode(void *ctx, const char *sdp_str, enum sdp_mode mode);

72
src/sip.c
View File

@ -104,7 +104,6 @@ static void new_call(struct sip_agent *agent, nua_handle_t *nh,
struct call *call;
struct sip_call_leg *leg;
const char *from = NULL, *to = NULL;
char ip_addr[INET_ADDRSTRLEN];
LOGP(DSIP, LOGL_INFO, "Incoming call(%s) handle(%p)\n", sip->sip_call_id->i_id, nh);
@ -146,11 +145,10 @@ static void new_call(struct sip_agent *agent, nua_handle_t *nh,
static void sip_handle_reinvite(struct sip_call_leg *leg, nua_handle_t *nh, const sip_t *sip) {
const char *reinvite_sdp;
char *sdp;
sdp_mode_t mode = sdp_sendrecv;
uint32_t ip = leg->base.ip;
uint16_t port = leg->base.port;
char ip_addr[INET_ADDRSTRLEN];
enum sdp_mode mode;
enum sdp_mode mode_other;
LOGP(DSIP, LOGL_INFO, "re-INVITE for call %s\n", sip->sip_call_id->i_id);
@ -162,11 +160,12 @@ static void sip_handle_reinvite(struct sip_call_leg *leg, nua_handle_t *nh, cons
return;
}
if (!sdp_get_sdp_mode(sip, &mode)) {
reinvite_sdp = sip_get_sdp(sip);
if (!reinvite_sdp) {
/* re-INVITE with no SDP.
* We should respond with SDP reflecting current session
*/
sdp = sdp_create_file(leg, other, sdp_sendrecv);
sdp = sdp_copy_and_set_mode(leg, other->sdp, SDP_MODE_SENDRECV);
nua_respond(nh, SIP_200_OK,
NUTAG_MEDIA_ENABLE(0),
SIPTAG_CONTENT_TYPE_STR("application/sdp"),
@ -176,37 +175,32 @@ static void sip_handle_reinvite(struct sip_call_leg *leg, nua_handle_t *nh, cons
return;
}
struct in_addr net = { .s_addr = leg->base.ip };
inet_ntop(AF_INET, &net, ip_addr, sizeof(ip_addr));
LOGP(DSIP, LOGL_DEBUG, "pre re-INVITE have IP:port (%s:%u)\n", ip_addr, leg->base.port);
mode = sdp_get_mode(reinvite_sdp, NULL);
call_leg_update_sdp(&leg->base, sip_get_sdp(sip));
call_leg_update_sdp(&leg->base, reinvite_sdp);
if (mode == sdp_sendonly) {
switch (mode) {
case SDP_MODE_SENDONLY:
/* SIP side places call on HOLD */
sdp = sdp_create_file(leg, other, sdp_recvonly);
/* TODO: Tell core network to stop sending RTP ? */
} else {
/* SIP re-INVITE may want to change media, IP, port */
if (!sdp_extract_sdp(leg, sip, true)) {
LOGP(DSIP, LOGL_ERROR, "leg(%p) no audio, releasing\n", leg);
nua_respond(nh, SIP_406_NOT_ACCEPTABLE, TAG_END());
nua_handle_destroy(nh);
call_leg_release(&leg->base);
return;
}
struct in_addr net = { .s_addr = leg->base.ip };
inet_ntop(AF_INET, &net, ip_addr, sizeof(ip_addr));
LOGP(DSIP, LOGL_DEBUG, "Media IP:port in re-INVITE: (%s:%u)\n", ip_addr, leg->base.port);
if (ip != leg->base.ip || port != leg->base.port) {
LOGP(DSIP, LOGL_INFO, "re-INVITE changes media connection.\n");
if (other->update_rtp)
other->update_rtp(leg->base.call->remote);
}
sdp = sdp_create_file(leg, other, sdp_sendrecv);
mode_other = SDP_MODE_RECVONLY;
break;
case SDP_MODE_RECVONLY:
mode_other = SDP_MODE_SENDONLY;
break;
case SDP_MODE_INACTIVE:
mode_other = SDP_MODE_INACTIVE;
break;
default:
mode_other = SDP_MODE_SENDRECV;
break;
}
LOGP(DSIP, LOGL_DEBUG, "Sending 200 response to re-INVITE for mode(%u)\n", mode);
if (other->update_rtp)
other->update_rtp(leg->base.call->remote);
sdp = sdp_copy_and_set_mode(leg, other->sdp, mode_other);
LOGP(DSIP, LOGL_DEBUG, "Sending 200 response (%s) to re-INVITE with mode '%s'\n",
sdp_mode_name(mode_other), sdp_mode_name(mode));
nua_respond(nh, SIP_200_OK,
NUTAG_MEDIA_ENABLE(0),
SIPTAG_CONTENT_TYPE_STR("application/sdp"),
@ -472,17 +466,13 @@ static void sip_connect_call(struct call_leg *_leg)
OSMO_ASSERT(_leg->type == CALL_TYPE_SIP);
leg = (struct sip_call_leg *) _leg;
/*
* TODO/FIXME: check if resulting codec is compatible..
*/
other = call_leg_other(&leg->base);
if (!other) {
sip_release_call(&leg->base);
return;
}
sdp = sdp_create_file(leg, other, sdp_sendrecv);
sdp = sdp_copy_and_set_mode(leg, other->sdp, SDP_MODE_SENDRECV);
leg->state = SIP_CC_CONNECTED;
nua_respond(leg->nua_handle, SIP_200_OK,
@ -521,7 +511,7 @@ static void sip_hold_call(struct call_leg *_leg)
sip_release_call(&leg->base);
return;
}
char *sdp = sdp_create_file(leg, other_leg, sdp_sendonly);
char *sdp = sdp_copy_and_set_mode(leg, other_leg->sdp, SDP_MODE_SENDONLY);
nua_invite(leg->nua_handle,
NUTAG_MEDIA_ENABLE(0),
SIPTAG_CONTENT_TYPE_STR("application/sdp"),
@ -543,7 +533,7 @@ static void sip_retrieve_call(struct call_leg *_leg)
sip_release_call(&leg->base);
return;
}
char *sdp = sdp_create_file(leg, other_leg, sdp_sendrecv);
char *sdp = sdp_copy_and_set_mode(leg, other_leg->sdp, SDP_MODE_SENDRECV);
nua_invite(leg->nua_handle,
NUTAG_MEDIA_ENABLE(0),
SIPTAG_CONTENT_TYPE_STR("application/sdp"),
@ -566,7 +556,7 @@ static int send_invite(struct sip_agent *agent, struct sip_call_leg *leg,
called_num,
agent->app->sip.remote_addr,
agent->app->sip.remote_port);
char *sdp = sdp_create_file(leg, other, sdp_sendrecv);
char *sdp = sdp_copy_and_set_mode(leg, other->sdp, SDP_MODE_SENDRECV);
leg->state = SIP_CC_INITIAL;
leg->dir = SIP_DIR_MT;