| /* mgcp_utils - common functions to setup an MGCP connection |
| */ |
| /* (C) 2016 by sysmocom s.f.m.c. GmbH <info@sysmocom.de> |
| * All Rights Reserved |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 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 General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| * |
| */ |
| |
| #include <osmocom/core/linuxlist.h> |
| #include <osmocom/core/select.h> |
| #include <osmocom/core/write_queue.h> |
| #include <osmocom/core/msgb.h> |
| #include <osmocom/core/logging.h> |
| #include <osmocom/core/byteswap.h> |
| #include <osmocom/core/socket.h> |
| #include <osmocom/core/sockaddr_str.h> |
| |
| #include <osmocom/mgcp_client/mgcp_client.h> |
| #include <osmocom/mgcp_client/mgcp_client_internal.h> |
| |
| #include <netinet/in.h> |
| #include <arpa/inet.h> |
| |
| #include <errno.h> |
| #include <unistd.h> |
| #include <string.h> |
| #include <ctype.h> |
| #include <stdlib.h> |
| #include <limits.h> |
| |
| #ifndef OSMUX_CID_MAX |
| #define OSMUX_CID_MAX 255 /* FIXME: use OSMUX_CID_MAX from libosmo-netif? */ |
| #endif |
| |
| /* Codec descripton for dynamic payload types (SDP) */ |
| const struct value_string osmo_mgcpc_codec_names[] = { |
| { CODEC_PCMU_8000_1, "PCMU/8000/1" }, |
| { CODEC_GSM_8000_1, "GSM/8000/1" }, |
| { CODEC_PCMA_8000_1, "PCMA/8000/1" }, |
| { CODEC_G729_8000_1, "G729/8000/1" }, |
| { CODEC_GSMEFR_8000_1, "GSM-EFR/8000/1" }, |
| { CODEC_GSMHR_8000_1, "GSM-HR-08/8000/1" }, |
| { CODEC_AMR_8000_1, "AMR/8000/1" }, |
| { CODEC_AMRWB_16000_1, "AMR-WB/16000/1" }, |
| { 0, NULL }, |
| }; |
| |
| /* Get encoding name from a full codec string e,g. |
| * ("CODEC/8000/2" => returns "CODEC") */ |
| static char *extract_codec_name(const char *str) |
| { |
| static char buf[64]; |
| unsigned int i; |
| |
| if (!str) |
| return NULL; |
| |
| /* FIXME osmo_strlcpy */ |
| osmo_strlcpy(buf, str, sizeof(buf)); |
| |
| for (i = 0; i < strlen(buf); i++) { |
| if (buf[i] == '/') |
| buf[i] = '\0'; |
| } |
| |
| return buf; |
| } |
| |
| /*! Map a string to a codec. |
| * \ptmap[in] str input string (e.g "GSM/8000/1", "GSM/8000" or "GSM") |
| * \returns codec that corresponds to the given string representation. */ |
| enum mgcp_codecs map_str_to_codec(const char *str) |
| { |
| unsigned int i; |
| char *codec_name; |
| char str_buf[64]; |
| |
| osmo_strlcpy(str_buf, extract_codec_name(str), sizeof(str_buf)); |
| |
| for (i = 0; i < ARRAY_SIZE(osmo_mgcpc_codec_names); i++) { |
| codec_name = extract_codec_name(osmo_mgcpc_codec_names[i].str); |
| if (!codec_name) |
| continue; |
| if (strcmp(codec_name, str_buf) == 0) |
| return osmo_mgcpc_codec_names[i].value; |
| } |
| |
| return -1; |
| } |
| |
| /* Check the ptmap for illegal mappings */ |
| static int check_ptmap(const struct ptmap *ptmap) |
| { |
| /* Check if there are mappings that leave the IANA assigned dynamic |
| * payload type range. Under normal conditions such mappings should |
| * not occur */ |
| |
| /* Its ok to have a 1:1 mapping in the statically defined |
| * range, this won't hurt */ |
| if (ptmap->codec == ptmap->pt) |
| return 0; |
| |
| if (ptmap->codec < 96 || ptmap->codec > 127) |
| goto error; |
| if (ptmap->pt < 96 || ptmap->pt > 127) |
| goto error; |
| |
| return 0; |
| error: |
| LOGP(DLMGCP, LOGL_ERROR, |
| "ptmap contains illegal mapping: codec=%u maps to pt=%u\n", |
| ptmap->codec, ptmap->pt); |
| return -1; |
| } |
| |
| /*! Map a codec to a payload type. |
| * \ptmap[in] payload pointer to payload type map with specified payload types. |
| * \ptmap[in] ptmap_len length of the payload type map. |
| * \ptmap[in] codec the codec for which the payload type should be looked up. |
| * \returns assigned payload type */ |
| unsigned int map_codec_to_pt(const struct ptmap *ptmap, unsigned int ptmap_len, |
| enum mgcp_codecs codec) |
| { |
| unsigned int i; |
| |
| /*! Note: If the payload type map is empty or the codec is not found |
| * in the map, then a 1:1 mapping is performed. If the codec falls |
| * into the statically defined range or if the mapping table isself |
| * tries to map to the statically defined range, then the mapping |
| * is also ignored and a 1:1 mapping is performed instead. */ |
| |
| /* we may return the codec directly since enum mgcp_codecs directly |
| * corresponds to the statićally assigned payload types */ |
| if (codec < 96 || codec > 127) |
| return codec; |
| |
| for (i = 0; i < ptmap_len; i++) { |
| /* Skip illegal map entries */ |
| if (check_ptmap(ptmap) == 0 && ptmap->codec == codec) |
| return ptmap->pt; |
| ptmap++; |
| } |
| |
| /* If nothing is found, do not perform any mapping */ |
| return codec; |
| } |
| |
| /*! Map a payload type to a codec. |
| * \ptmap[in] payload pointer to payload type map with specified payload types. |
| * \ptmap[in] ptmap_len length of the payload type map. |
| * \ptmap[in] payload type for which the codec should be looked up. |
| * \returns codec that corresponds to the specified payload type */ |
| enum mgcp_codecs map_pt_to_codec(struct ptmap *ptmap, unsigned int ptmap_len, |
| unsigned int pt) |
| { |
| unsigned int i; |
| |
| /*! Note: If the payload type map is empty or the payload type is not |
| * found in the map, then a 1:1 mapping is performed. If the payload |
| * type falls into the statically defined range or if the mapping |
| * table isself tries to map to the statically defined range, then |
| * the mapping is also ignored and a 1:1 mapping is performed |
| * instead. */ |
| |
| /* See also note in map_codec_to_pt() */ |
| if (pt < 96 || pt > 127) |
| return pt; |
| |
| for (i = 0; i < ptmap_len; i++) { |
| if (check_ptmap(ptmap) == 0 && ptmap->pt == pt) |
| return ptmap->codec; |
| ptmap++; |
| } |
| |
| /* If nothing is found, do not perform any mapping */ |
| return pt; |
| } |
| |
| /*! Initalize MGCP client configuration struct with default values. |
| * \param[out] conf Client configuration.*/ |
| void mgcp_client_conf_init(struct mgcp_client_conf *conf) |
| { |
| /* NULL and -1 default to MGCP_CLIENT_*_DEFAULT values */ |
| *conf = (struct mgcp_client_conf){ |
| .local_addr = NULL, |
| .local_port = -1, |
| .remote_addr = NULL, |
| .remote_port = -1, |
| }; |
| } |
| |
| static void mgcp_client_handle_response(struct mgcp_client *mgcp, |
| struct mgcp_response_pending *pending, |
| struct mgcp_response *response) |
| { |
| if (!pending) { |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Cannot handle NULL response\n"); |
| return; |
| } |
| if (pending->response_cb) |
| pending->response_cb(response, pending->priv); |
| else |
| LOGP(DLMGCP, LOGL_DEBUG, "MGCP response ignored (NULL cb)\n"); |
| talloc_free(pending); |
| } |
| |
| static int mgcp_response_parse_head(struct mgcp_response *r, struct msgb *msg) |
| { |
| int comment_pos; |
| char *end; |
| |
| if (mgcp_msg_terminate_nul(msg)) |
| goto response_parse_failure; |
| |
| r->body = (char *)msg->data; |
| |
| if (sscanf(r->body, "%3d %u %n", |
| &r->head.response_code, &r->head.trans_id, |
| &comment_pos) != 2) |
| goto response_parse_failure; |
| |
| osmo_strlcpy(r->head.comment, r->body + comment_pos, sizeof(r->head.comment)); |
| end = strchr(r->head.comment, '\r'); |
| if (!end) |
| goto response_parse_failure; |
| /* Mark the end of the comment */ |
| *end = '\0'; |
| return 0; |
| |
| response_parse_failure: |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Failed to parse MGCP response header\n"); |
| return -EINVAL; |
| } |
| |
| /* TODO undup against mgcp_protocol.c:mgcp_check_param() */ |
| static bool mgcp_line_is_valid(const char *line) |
| { |
| const size_t line_len = strlen(line); |
| if (line[0] == '\0') |
| return true; |
| |
| if (line_len < 2 |
| || line[1] != '=') { |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Wrong MGCP option format: '%s'\n", |
| line); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| /* Parse a line like "m=audio 16002 RTP/AVP 98", extract port and payload types */ |
| static int mgcp_parse_audio_port_pt(struct mgcp_response *r, char *line) |
| { |
| char *pt_str; |
| char *pt_end; |
| unsigned long int pt; |
| unsigned int count = 0; |
| unsigned int i; |
| |
| /* Extract port information */ |
| if (sscanf(line, "m=audio %hu", &r->audio_port) != 1) |
| goto response_parse_failure_port; |
| if (r->audio_port == 0) |
| goto response_parse_failure_port; |
| |
| /* Extract payload types */ |
| line = strstr(line, "RTP/AVP "); |
| if (!line) |
| goto exit; |
| |
| pt_str = strtok(line, " "); |
| while (1) { |
| /* Do not allow excessive payload types */ |
| if (count > ARRAY_SIZE(r->codecs)) |
| goto response_parse_failure_pt; |
| |
| pt_str = strtok(NULL, " "); |
| if (!pt_str) |
| break; |
| errno = 0; |
| pt = strtoul(pt_str, &pt_end, 0); |
| if ((errno == ERANGE && pt == ULONG_MAX) || (errno && !pt) || |
| pt_str == pt_end) |
| goto response_parse_failure_pt; |
| |
| if (pt >> 7) /* PT is 7 bit field, higher values not allowed */ |
| goto response_parse_failure_pt; |
| |
| /* Do not allow duplicate payload types */ |
| for (i = 0; i < count; i++) |
| if (r->codecs[i] == pt) |
| goto response_parse_failure_pt; |
| |
| /* Note: The payload type we store may not necessarly match |
| * the codec types we have defined in enum mgcp_codecs. To |
| * ensure that the end result only contains codec types which |
| * match enum mgcp_codecs, we will go through afterwards and |
| * remap the affected entries with the inrofmation we learn |
| * from rtpmap */ |
| r->codecs[count] = pt; |
| count++; |
| } |
| |
| r->codecs_len = count; |
| |
| exit: |
| return 0; |
| |
| response_parse_failure_port: |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Failed to parse SDP parameter port (%s)\n", line); |
| return -EINVAL; |
| |
| response_parse_failure_pt: |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Failed to parse SDP parameter payload types (%s)\n", line); |
| return -EINVAL; |
| } |
| |
| /* Parse a line like "m=audio 16002 RTP/AVP 98", extract port and payload types */ |
| static int mgcp_parse_audio_ptime_rtpmap(struct mgcp_response *r, const char *line) |
| { |
| unsigned int pt; |
| char codec_resp[64]; |
| enum mgcp_codecs codec; |
| |
| #define A_PTIME "a=ptime:" |
| #define A_RTPMAP "a=rtpmap:" |
| |
| if (osmo_str_startswith(line, A_PTIME)) { |
| if (sscanf(line, A_PTIME "%u", &r->ptime) != 1) { |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Failed to parse SDP parameter, invalid ptime (%s)\n", line); |
| return -EINVAL; |
| } |
| } else if (osmo_str_startswith(line, A_RTPMAP)) { |
| if (sscanf(line, A_RTPMAP "%d %63s", &pt, codec_resp) != 2) { |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Failed to parse SDP parameter, invalid rtpmap: %s\n", osmo_quote_str(line, -1)); |
| return -EINVAL; |
| } |
| if (r->ptmap_len >= ARRAY_SIZE(r->ptmap)) { |
| LOGP(DLMGCP, LOGL_ERROR, "No more space in ptmap array (len=%u)\n", r->ptmap_len); |
| return -ENOSPC; |
| } |
| codec = map_str_to_codec(codec_resp); |
| r->ptmap[r->ptmap_len].pt = pt; |
| r->ptmap[r->ptmap_len].codec = codec; |
| r->ptmap_len++; |
| } |
| |
| return 0; |
| } |
| |
| /* Parse a line like "c=IN IP4 10.11.12.13" */ |
| static int mgcp_parse_audio_ip(struct mgcp_response *r, const char *line) |
| { |
| struct in6_addr ip_test; |
| bool is_ipv6; |
| |
| if (strncmp("c=IN IP", line, 7) != 0) |
| goto response_parse_failure; |
| line += 7; |
| if (*line == '6') |
| is_ipv6 = true; |
| else if (*line == '4') |
| is_ipv6 = false; |
| else |
| goto response_parse_failure; |
| line++; |
| if (*line != ' ') |
| goto response_parse_failure; |
| line++; |
| |
| /* Extract and check IP-Address */ |
| if (is_ipv6) { |
| /* 45 = INET6_ADDRSTRLEN -1 */ |
| if (sscanf(line, "%45s", r->audio_ip) != 1) |
| goto response_parse_failure; |
| if (inet_pton(AF_INET6, r->audio_ip, &ip_test) != 1) |
| goto response_parse_failure; |
| } else { |
| /* 15 = INET_ADDRSTRLEN -1 */ |
| if (sscanf(line, "%15s", r->audio_ip) != 1) |
| goto response_parse_failure; |
| if (inet_pton(AF_INET, r->audio_ip, &ip_test) != 1) |
| goto response_parse_failure; |
| } |
| return 0; |
| |
| response_parse_failure: |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Failed to parse MGCP response header (audio ip)\n"); |
| return -EINVAL; |
| } |
| |
| /*! Extract OSMUX CID from an MGCP parameter line (string). |
| * \param[in] line single parameter line from the MGCP message |
| * \returns OSMUX CID, -1 wildcard, -2 on error |
| * FIXME: This is a copy of function in mgcp_msg.c. Have some common.c file between both libs? |
| */ |
| static int mgcp_parse_osmux_cid(const char *line) |
| { |
| int osmux_cid; |
| |
| |
| if (strcasecmp(line + 2, "Osmux: *") == 0) { |
| LOGP(DLMGCP, LOGL_DEBUG, "Parsed wilcard Osmux CID\n"); |
| return -1; |
| } |
| |
| if (sscanf(line + 2 + 7, "%u", &osmux_cid) != 1) { |
| LOGP(DLMGCP, LOGL_ERROR, "Failed parsing Osmux in MGCP msg line: %s\n", |
| line); |
| return -2; |
| } |
| |
| if (osmux_cid > OSMUX_CID_MAX) { /* OSMUX_CID_MAX from libosmo-netif */ |
| LOGP(DLMGCP, LOGL_ERROR, "Osmux ID too large: %u > %u\n", |
| osmux_cid, OSMUX_CID_MAX); |
| return -2; |
| } |
| LOGP(DLMGCP, LOGL_DEBUG, "bsc-nat offered Osmux CID %u\n", osmux_cid); |
| |
| return osmux_cid; |
| } |
| |
| /* A new section is marked by a double line break, check a few more |
| * patterns as there may be variants */ |
| static char *mgcp_find_section_end(char *string) |
| { |
| char *rc; |
| |
| rc = strstr(string, "\n\n"); |
| if (rc) |
| return rc; |
| |
| rc = strstr(string, "\n\r\n\r"); |
| if (rc) |
| return rc; |
| |
| rc = strstr(string, "\r\n\r\n"); |
| if (rc) |
| return rc; |
| |
| return NULL; |
| } |
| |
| /*! Parse body (SDP) parameters of the MGCP response |
| * \param[in,out] r Response data |
| * \returns 0 on success, -EINVAL on error. */ |
| int mgcp_response_parse_params(struct mgcp_response *r) |
| { |
| char *line; |
| int rc; |
| char *data; |
| char *data_ptr; |
| int i; |
| |
| /* Since this functions performs a destructive parsing, we create a |
| * local copy of the body data */ |
| OSMO_ASSERT(r->body); |
| data = talloc_strdup(r, r->body); |
| OSMO_ASSERT(data); |
| |
| /* Find beginning of the parameter (SDP) section */ |
| data_ptr = mgcp_find_section_end(data); |
| if (!data_ptr) { |
| LOGP(DLMGCP, LOGL_DEBUG, "MGCP response contains no SDP parameters\n"); |
| rc = 0; |
| goto exit; |
| } |
| |
| /* data_ptr now points to the beginning of the section-end-marker; for_each_non_empty_line() |
| * skips any \r and \n characters for free, so we don't need to skip the marker. */ |
| |
| for_each_non_empty_line(line, data_ptr) { |
| if (!mgcp_line_is_valid(line)) |
| return -EINVAL; |
| |
| switch (line[0]) { |
| case 'a': |
| rc = mgcp_parse_audio_ptime_rtpmap(r, line); |
| if (rc) |
| goto exit; |
| break; |
| case 'm': |
| rc = mgcp_parse_audio_port_pt(r, line); |
| if (rc) |
| goto exit; |
| break; |
| case 'c': |
| rc = mgcp_parse_audio_ip(r, line); |
| if (rc) |
| goto exit; |
| break; |
| default: |
| /* skip unhandled parameters */ |
| break; |
| } |
| } |
| |
| /* See also note in mgcp_parse_audio_port_pt() */ |
| for (i = 0; i < r->codecs_len; i++) |
| r->codecs[i] = map_pt_to_codec(r->ptmap, r->ptmap_len, r->codecs[i]); |
| |
| rc = 0; |
| exit: |
| talloc_free(data); |
| return rc; |
| } |
| |
| /* Parse a line like "X: something" */ |
| static int mgcp_parse_head_param(char *result, unsigned int result_len, |
| char label, const char *line) |
| { |
| char label_string[4]; |
| size_t rc; |
| |
| /* Detect empty parameters */ |
| if (strlen(line) < 4) |
| goto response_parse_failure; |
| |
| /* Check if the label matches */ |
| snprintf(label_string, sizeof(label_string), "%c: ", label); |
| if (memcmp(label_string, line, 3) != 0) |
| goto response_parse_failure; |
| |
| /* Copy payload part of the string to destinations (the label string |
| * is always 3 chars long) */ |
| rc = osmo_strlcpy(result, line + 3, result_len); |
| if (rc >= result_len) { |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Failed to parse MGCP response (parameter label: %c):" |
| " the received conn ID is too long: %zu, maximum is %u characters\n", |
| label, rc, result_len - 1); |
| return -ENOSPC; |
| } |
| return 0; |
| |
| response_parse_failure: |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Failed to parse MGCP response (parameter label: %c)\n", label); |
| return -EINVAL; |
| } |
| |
| /* Parse MGCP parameters of the response */ |
| static int parse_head_params(struct mgcp_response *r) |
| { |
| char *line; |
| int rc = 0; |
| OSMO_ASSERT(r->body); |
| char *data; |
| char *data_ptr; |
| char *data_end; |
| |
| /* Since this functions performs a destructive parsing, we create a |
| * local copy of the body data */ |
| data = talloc_zero_size(r, strlen(r->body)+1); |
| OSMO_ASSERT(data); |
| data_ptr = data; |
| osmo_strlcpy(data, r->body, strlen(r->body)); |
| |
| /* If there is an SDP body attached, prevent for_each_non_empty_line() |
| * into running in there, we are not yet interested in the parameters |
| * stored there. */ |
| data_end = mgcp_find_section_end(data); |
| if (data_end) |
| *data_end = '\0'; |
| |
| for_each_non_empty_line(line, data_ptr) { |
| switch (toupper(line[0])) { |
| case 'Z': |
| rc = mgcp_parse_head_param(r->head.endpoint, |
| sizeof(r->head.endpoint), |
| 'Z', line); |
| if (rc) |
| goto exit; |
| |
| /* A specific endpoint identifier returned by the MGW |
| * must not contain any wildcard characters */ |
| if (strstr(r->head.endpoint, "*") != NULL) { |
| rc = -EINVAL; |
| goto exit; |
| } |
| |
| /* A specific endpoint identifier returned by the MGW |
| * must contain an @ character */ |
| if (strstr(r->head.endpoint, "@") == NULL) { |
| rc = -EINVAL; |
| goto exit; |
| } |
| break; |
| case 'I': |
| rc = mgcp_parse_head_param(r->head.conn_id, |
| sizeof(r->head.conn_id), |
| 'I', line); |
| if (rc) |
| goto exit; |
| break; |
| case 'X': |
| if (strncasecmp("Osmux: ", line + 2, strlen("Osmux: ")) == 0) { |
| rc = mgcp_parse_osmux_cid(line); |
| if (rc < 0) { |
| /* -1: we don't want wildcards in response. -2: error */ |
| rc = -EINVAL; |
| goto exit; |
| } |
| r->head.x_osmo_osmux_use = true; |
| r->head.x_osmo_osmux_cid = (uint8_t) rc; |
| rc = 0; |
| break; |
| } |
| /* Ignore unknown X-headers */ |
| break; |
| default: |
| /* skip unhandled parameters */ |
| break; |
| } |
| } |
| exit: |
| talloc_free(data); |
| return rc; |
| } |
| |
| static struct mgcp_response_pending *mgcp_client_response_pending_get( |
| struct mgcp_client *mgcp, |
| mgcp_trans_id_t trans_id) |
| { |
| struct mgcp_response_pending *pending; |
| llist_for_each_entry(pending, &mgcp->responses_pending, entry) { |
| if (pending->trans_id == trans_id) { |
| llist_del(&pending->entry); |
| return pending; |
| } |
| } |
| return NULL; |
| } |
| |
| /* Feed an MGCP message into the receive processing. |
| * Parse the head and call any callback registered for the transaction id found |
| * in the MGCP message. This is normally called directly from the internal |
| * mgcp_do_read that reads from the socket connected to the MGCP gateway. This |
| * function is published mainly to be able to feed data from the test suite. |
| */ |
| int mgcp_client_rx(struct mgcp_client *mgcp, struct msgb *msg) |
| { |
| struct mgcp_response *r; |
| struct mgcp_response_pending *pending; |
| int rc; |
| |
| r = talloc_zero(mgcp, struct mgcp_response); |
| OSMO_ASSERT(r); |
| |
| rc = mgcp_response_parse_head(r, msg); |
| if (rc) { |
| LOGP(DLMGCP, LOGL_ERROR, "Cannot parse MGCP response (head)\n"); |
| rc = 1; |
| goto error; |
| } |
| |
| rc = parse_head_params(r); |
| if (rc) { |
| LOGP(DLMGCP, LOGL_ERROR, "Cannot parse MGCP response (head parameters)\n"); |
| rc = 1; |
| goto error; |
| } |
| |
| pending = mgcp_client_response_pending_get(mgcp, r->head.trans_id); |
| if (!pending) { |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Cannot find matching MGCP transaction for trans_id %d\n", |
| r->head.trans_id); |
| rc = -ENOENT; |
| goto error; |
| } |
| |
| mgcp_client_handle_response(mgcp, pending, r); |
| rc = 0; |
| |
| error: |
| talloc_free(r); |
| return rc; |
| } |
| |
| static int mgcp_do_read(struct osmo_fd *fd) |
| { |
| struct mgcp_client *mgcp = fd->data; |
| struct msgb *msg; |
| int ret; |
| |
| msg = msgb_alloc_headroom(4096, 128, "mgcp_from_gw"); |
| if (!msg) { |
| LOGP(DLMGCP, LOGL_ERROR, "Failed to allocate MGCP message.\n"); |
| return -1; |
| } |
| |
| ret = read(fd->fd, msg->data, 4096 - 128); |
| if (ret <= 0) { |
| LOGP(DLMGCP, LOGL_ERROR, "Failed to read: %s: %d='%s'\n", osmo_sock_get_name2(fd->fd), |
| errno, strerror(errno)); |
| |
| msgb_free(msg); |
| return -1; |
| } else if (ret > 4096 - 128) { |
| LOGP(DLMGCP, LOGL_ERROR, "Too much data: %s: %d\n", osmo_sock_get_name2(fd->fd), ret); |
| msgb_free(msg); |
| return -1; |
| } |
| |
| msg->l2h = msgb_put(msg, ret); |
| ret = mgcp_client_rx(mgcp, msg); |
| talloc_free(msg); |
| return ret; |
| } |
| |
| static int mgcp_do_write(struct osmo_fd *fd, struct msgb *msg) |
| { |
| int ret; |
| |
| LOGP(DLMGCP, LOGL_DEBUG, "Tx MGCP: %s: len=%u '%s'...\n", |
| osmo_sock_get_name2(fd->fd), msg->len, osmo_escape_str((const char*)msg->data, OSMO_MIN(42, msg->len))); |
| |
| ret = write(fd->fd, msg->data, msg->len); |
| if (ret != msg->len) |
| LOGP(DLMGCP, LOGL_ERROR, "Failed to Tx MGCP: %s: %d='%s'; msg: len=%u '%s'...\n", |
| osmo_sock_get_name2(fd->fd), errno, strerror(errno), |
| msg->len, osmo_escape_str((const char*)msg->data, OSMO_MIN(42, msg->len))); |
| return ret; |
| } |
| |
| struct mgcp_client *mgcp_client_init(void *ctx, |
| struct mgcp_client_conf *conf) |
| { |
| struct mgcp_client *mgcp; |
| |
| mgcp = talloc_zero(ctx, struct mgcp_client); |
| if (!mgcp) |
| return NULL; |
| |
| INIT_LLIST_HEAD(&mgcp->responses_pending); |
| INIT_LLIST_HEAD(&mgcp->inuse_endpoints); |
| |
| mgcp->next_trans_id = 1; |
| |
| mgcp->actual.local_addr = conf->local_addr ? conf->local_addr : |
| MGCP_CLIENT_LOCAL_ADDR_DEFAULT; |
| mgcp->actual.local_port = conf->local_port >= 0 ? (uint16_t)conf->local_port : |
| MGCP_CLIENT_LOCAL_PORT_DEFAULT; |
| |
| mgcp->actual.remote_addr = conf->remote_addr ? conf->remote_addr : |
| MGCP_CLIENT_REMOTE_ADDR_DEFAULT; |
| mgcp->actual.remote_port = conf->remote_port >= 0 ? (uint16_t)conf->remote_port : |
| MGCP_CLIENT_REMOTE_PORT_DEFAULT; |
| |
| if (osmo_strlcpy(mgcp->actual.endpoint_domain_name, conf->endpoint_domain_name, |
| sizeof(mgcp->actual.endpoint_domain_name)) |
| >= sizeof(mgcp->actual.endpoint_domain_name)) { |
| LOGP(DLMGCP, LOGL_ERROR, "MGCP client: endpoint domain name is too long, max length is %zu: '%s'\n", |
| sizeof(mgcp->actual.endpoint_domain_name) - 1, conf->endpoint_domain_name); |
| talloc_free(mgcp); |
| return NULL; |
| } |
| LOGP(DLMGCP, LOGL_NOTICE, "MGCP client: using endpoint domain '@%s'\n", mgcp_client_endpoint_domain(mgcp)); |
| |
| return mgcp; |
| } |
| |
| static int init_socket(struct mgcp_client *mgcp) |
| { |
| int rc; |
| struct osmo_wqueue *wq; |
| int i; |
| |
| wq = &mgcp->wq; |
| |
| for (i = 0; i < 100; i++) { |
| |
| /* Initalize socket with the currently configured port |
| * number */ |
| rc = osmo_sock_init2_ofd(&wq->bfd, AF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP, mgcp->actual.local_addr, |
| mgcp->actual.local_port, mgcp->actual.remote_addr, mgcp->actual.remote_port, |
| OSMO_SOCK_F_BIND | OSMO_SOCK_F_CONNECT); |
| if (rc > 0) |
| return rc; |
| |
| /* If there is a different port than the default port |
| * configured then we assume that the user has choosen |
| * that port conciously and we will not try to resolve |
| * this by silently choosing a different port. */ |
| if (mgcp->actual.local_port != MGCP_CLIENT_LOCAL_PORT_DEFAULT && i == 0) |
| return -EINVAL; |
| |
| /* Choose a new port number to try next */ |
| LOGP(DLMGCP, LOGL_NOTICE, |
| "MGCPGW failed to bind to %s:%u, retrying with port %u\n", |
| mgcp->actual.local_addr, mgcp->actual.local_port, mgcp->actual.local_port + 1); |
| mgcp->actual.local_port++; |
| } |
| |
| LOGP(DLMGCP, LOGL_FATAL, "MGCPGW failed to find a port to bind on %i times.\n", i); |
| return -EINVAL; |
| } |
| |
| /*! Initalize client connection (opens socket only, no request is sent yet) |
| * \param[in,out] mgcp MGCP client descriptor. |
| * \returns 0 on success, -EINVAL on error. */ |
| int mgcp_client_connect(struct mgcp_client *mgcp) |
| { |
| struct osmo_wqueue *wq; |
| int rc; |
| |
| if (!mgcp) { |
| LOGP(DLMGCP, LOGL_FATAL, "MGCPGW client not initialized properly\n"); |
| return -EINVAL; |
| } |
| |
| wq = &mgcp->wq; |
| |
| rc = init_socket(mgcp); |
| if (rc < 0) { |
| LOGP(DLMGCP, LOGL_FATAL, |
| "Failed to initialize socket %s:%u -> %s:%u for MGCP GW: %s\n", |
| mgcp->actual.local_addr, mgcp->actual.local_port, |
| mgcp->actual.remote_addr, mgcp->actual.remote_port, strerror(errno)); |
| goto error_close_fd; |
| } |
| |
| osmo_wqueue_init(wq, 1024); |
| wq->bfd.when = OSMO_FD_READ; |
| wq->bfd.data = mgcp; |
| wq->read_cb = mgcp_do_read; |
| wq->write_cb = mgcp_do_write; |
| |
| LOGP(DLMGCP, LOGL_INFO, "MGCP GW connection: %s\n", osmo_sock_get_name2(wq->bfd.fd)); |
| |
| return 0; |
| error_close_fd: |
| close(wq->bfd.fd); |
| wq->bfd.fd = -1; |
| return rc; |
| } |
| |
| /*! Get the IP-Aaddress of the associated MGW as string. |
| * \param[in] mgcp MGCP client descriptor. |
| * \returns a pointer to the address string. */ |
| const char *mgcp_client_remote_addr_str(struct mgcp_client *mgcp) |
| { |
| return mgcp->actual.remote_addr; |
| } |
| |
| /*! Get the IP-Port of the associated MGW. |
| * \param[in] mgcp MGCP client descriptor. |
| * \returns port number. */ |
| uint16_t mgcp_client_remote_port(struct mgcp_client *mgcp) |
| { |
| return mgcp->actual.remote_port; |
| } |
| |
| /*! Get the IP-Address of the associated MGW as its numeric representation. |
| * DEPRECATED, DON'T USE. |
| * \param[in] mgcp MGCP client descriptor. |
| * \returns IP-Address as 32 bit integer (network byte order) */ |
| uint32_t mgcp_client_remote_addr_n(struct mgcp_client *mgcp) |
| { |
| return 0; |
| } |
| |
| /* To compose endpoint names, usually for CRCX, use this as domain name. |
| * For example, snprintf("rtpbridge\*@%s", mgcp_client_endpoint_domain(mgcp)). */ |
| const char *mgcp_client_endpoint_domain(const struct mgcp_client *mgcp) |
| { |
| return mgcp->actual.endpoint_domain_name[0] ? mgcp->actual.endpoint_domain_name : "mgw"; |
| } |
| |
| static const char *_mgcp_client_name_append_domain(const struct mgcp_client *mgcp, char *name) |
| { |
| static char endpoint[MGCP_ENDPOINT_MAXLEN]; |
| int rc; |
| |
| rc = snprintf(endpoint, sizeof(endpoint), "%s@%s", name, mgcp_client_endpoint_domain(mgcp)); |
| if (rc > sizeof(endpoint) - 1) { |
| LOGP(DLMGCP, LOGL_ERROR, "MGCP endpoint exceeds maximum length of %zu: '%s@%s'\n", |
| sizeof(endpoint) - 1, name, mgcp_client_endpoint_domain(mgcp)); |
| return NULL; |
| } |
| if (rc < 1) { |
| LOGP(DLMGCP, LOGL_ERROR, "Cannot compose MGCP endpoint name\n"); |
| return NULL; |
| } |
| return endpoint; |
| } |
| |
| /*! Compose endpoint name for a wildcarded request to the virtual trunk |
| * \param[in] mgcp MGCP client descriptor. |
| * \returns string containing the endpoint name (e.g. rtpbridge\*@mgw) */ |
| const char *mgcp_client_rtpbridge_wildcard(const struct mgcp_client *mgcp) |
| { |
| return _mgcp_client_name_append_domain(mgcp, "rtpbridge/*"); |
| } |
| |
| /*! Compose endpoint name for an E1 endpoint. |
| * \param[in] ctx talloc context. |
| * \param[in] mgcp MGCP client descriptor. |
| * \param[in] trunk_id id number of the E1 trunk (1-64). |
| * \param[in] ts timeslot on the E1 trunk (1-31). |
| * \param[in] rate bitrate used on the E1 trunk (e.g 16 for 16kbit). |
| * \param[in] offset bit offset of the E1 subslot (e.g. 4 for the third 16k subslot). |
| * \returns string containing the endpoint name (e.g. ds/e1-1/s-1/su16-4). */ |
| const char *mgcp_client_e1_epname(void *ctx, const struct mgcp_client *mgcp, uint8_t trunk_id, uint8_t ts, |
| uint8_t rate, uint8_t offset) |
| { |
| /* See also comment in libosmo-mgcp, mgcp_client.c, gen_e1_epname() */ |
| const uint8_t valid_rates[] = { 64, 32, 32, 16, 16, 16, 16, 8, 8, 8, 8, 8, 8, 8, 8 }; |
| const uint8_t valid_offsets[] = { 0, 0, 4, 0, 2, 4, 6, 0, 1, 2, 3, 4, 5, 6, 7 }; |
| |
| uint8_t i; |
| bool rate_offs_valid = false; |
| char *epname; |
| |
| epname = |
| talloc_asprintf(ctx, "ds/e1-%u/s-%u/su%u-%u@%s", trunk_id, ts, rate, offset, |
| mgcp_client_endpoint_domain(mgcp)); |
| if (!epname) { |
| LOGP(DLMGCP, LOGL_ERROR, "Cannot compose MGCP e1-endpoint name!\n"); |
| return NULL; |
| } |
| |
| /* Check if the supplied rate/offset pair resembles a valid combination */ |
| for (i = 0; i < sizeof(valid_rates); i++) { |
| if (valid_rates[i] == rate && valid_offsets[i] == offset) |
| rate_offs_valid = true; |
| } |
| if (!rate_offs_valid) { |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Cannot compose MGCP e1-endpoint name (%s), rate(%u)/offset(%u) combination is invalid!\n", epname, |
| rate, offset); |
| talloc_free(epname); |
| return NULL; |
| } |
| |
| /* An E1 line has a maximum of 32 timeslots, while the first (ts=0) is |
| * reserverd for framing and alignment, so we can not use it here. */ |
| if (ts == 0 || ts > 31) { |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Cannot compose MGCP e1-endpoint name (%s), E1-timeslot number (%u) is invalid!\n", epname, ts); |
| talloc_free(epname); |
| return NULL; |
| } |
| |
| return epname; |
| } |
| |
| struct mgcp_response_pending * mgcp_client_pending_add( |
| struct mgcp_client *mgcp, |
| mgcp_trans_id_t trans_id, |
| mgcp_response_cb_t response_cb, |
| void *priv) |
| { |
| struct mgcp_response_pending *pending; |
| |
| pending = talloc_zero(mgcp, struct mgcp_response_pending); |
| if (!pending) |
| return NULL; |
| |
| pending->trans_id = trans_id; |
| pending->response_cb = response_cb; |
| pending->priv = priv; |
| llist_add_tail(&pending->entry, &mgcp->responses_pending); |
| |
| return pending; |
| } |
| |
| /* Send the MGCP message in msg to the MGCP GW and handle a response with |
| * response_cb. NOTE: the response_cb still needs to call |
| * mgcp_response_parse_params(response) to get the parsed parameters -- to |
| * potentially save some CPU cycles, only the head line has been parsed when |
| * the response_cb is invoked. |
| * Before the priv pointer becomes invalid, e.g. due to transaction timeout, |
| * mgcp_client_cancel() needs to be called for this transaction. |
| */ |
| int mgcp_client_tx(struct mgcp_client *mgcp, struct msgb *msg, |
| mgcp_response_cb_t response_cb, void *priv) |
| { |
| struct mgcp_response_pending *pending = NULL; |
| mgcp_trans_id_t trans_id; |
| int rc; |
| |
| trans_id = msg->cb[MSGB_CB_MGCP_TRANS_ID]; |
| if (!trans_id) { |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Unset transaction id in mgcp send request\n"); |
| talloc_free(msg); |
| return -EINVAL; |
| } |
| |
| /* Do not allocate a dummy 'mgcp_response_pending' entry */ |
| if (response_cb != NULL) { |
| pending = mgcp_client_pending_add(mgcp, trans_id, response_cb, priv); |
| if (!pending) { |
| talloc_free(msg); |
| return -ENOMEM; |
| } |
| } |
| |
| if (msgb_l2len(msg) > 4096) { |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Cannot send, MGCP message too large: %u\n", |
| msgb_l2len(msg)); |
| msgb_free(msg); |
| rc = -EINVAL; |
| goto mgcp_tx_error; |
| } |
| |
| rc = osmo_wqueue_enqueue(&mgcp->wq, msg); |
| if (rc) { |
| LOGP(DLMGCP, LOGL_FATAL, "Could not queue message to MGCP GW\n"); |
| msgb_free(msg); |
| goto mgcp_tx_error; |
| } else |
| LOGP(DLMGCP, LOGL_DEBUG, "Queued %u bytes for MGCP GW\n", |
| msgb_l2len(msg)); |
| return 0; |
| |
| mgcp_tx_error: |
| if (!pending) |
| return rc; |
| /* Dequeue pending response, it's going to be free()d */ |
| llist_del(&pending->entry); |
| /* Pass NULL to response cb to indicate an error */ |
| mgcp_client_handle_response(mgcp, pending, NULL); |
| return rc; |
| } |
| |
| /*! Cancel a pending transaction. |
| * \param[in] mgcp MGCP client descriptor. |
| * \param[in,out] trans_id Transaction id. |
| * \returns 0 on success, -ENOENT on error. |
| * |
| * Should a priv pointer passed to mgcp_client_tx() become invalid, this function must be called. In |
| * practical terms, if the caller of mgcp_client_tx() wishes to tear down a transaction without having |
| * received a response this function must be called. The trans_id can be obtained by calling |
| * mgcp_msg_trans_id() on the msgb produced by mgcp_msg_gen(). */ |
| int mgcp_client_cancel(struct mgcp_client *mgcp, mgcp_trans_id_t trans_id) |
| { |
| struct mgcp_response_pending *pending = mgcp_client_response_pending_get(mgcp, trans_id); |
| if (!pending) { |
| /*! Note: it is not harmful to cancel a transaction twice. */ |
| LOGP(DLMGCP, LOGL_ERROR, "Cannot cancel, no such transaction: %u\n", trans_id); |
| return -ENOENT; |
| } |
| LOGP(DLMGCP, LOGL_DEBUG, "Canceled transaction %u\n", trans_id); |
| talloc_free(pending); |
| return 0; |
| /*! We don't really need to clean up the wqueue: In all sane cases, the msgb has already been sent |
| * out and is no longer in the wqueue. If it still is in the wqueue, then sending MGCP messages |
| * per se is broken and the program should notice so by a full wqueue. Even if this was called |
| * before we had a chance to send out the message and it is still going to be sent, we will just |
| * ignore the reply to it later. Removing a msgb from the wqueue here would just introduce more |
| * bug surface in terms of failing to update wqueue API's counters or some such. |
| */ |
| } |
| |
| static mgcp_trans_id_t mgcp_client_next_trans_id(struct mgcp_client *mgcp) |
| { |
| /* avoid zero trans_id to distinguish from unset trans_id */ |
| if (!mgcp->next_trans_id) |
| mgcp->next_trans_id ++; |
| return mgcp->next_trans_id ++; |
| } |
| |
| #define MGCP_CRCX_MANDATORY (MGCP_MSG_PRESENCE_ENDPOINT | \ |
| MGCP_MSG_PRESENCE_CALL_ID | \ |
| MGCP_MSG_PRESENCE_CONN_MODE) |
| #define MGCP_MDCX_MANDATORY (MGCP_MSG_PRESENCE_ENDPOINT | \ |
| MGCP_MSG_PRESENCE_CALL_ID | \ |
| MGCP_MSG_PRESENCE_CONN_ID) |
| #define MGCP_DLCX_MANDATORY (MGCP_MSG_PRESENCE_ENDPOINT) |
| #define MGCP_AUEP_MANDATORY (MGCP_MSG_PRESENCE_ENDPOINT) |
| #define MGCP_RSIP_MANDATORY 0 /* none */ |
| |
| /* Helper function for mgcp_msg_gen(): Add LCO information to MGCP message */ |
| static int add_lco(struct msgb *msg, struct mgcp_msg *mgcp_msg) |
| { |
| unsigned int i; |
| int rc = 0; |
| const char *codec; |
| unsigned int pt; |
| |
| rc += msgb_printf(msg, "L:"); |
| |
| if (mgcp_msg->ptime) |
| rc += msgb_printf(msg, " p:%u,", mgcp_msg->ptime); |
| |
| if (mgcp_msg->codecs_len) { |
| rc += msgb_printf(msg, " a:"); |
| for (i = 0; i < mgcp_msg->codecs_len; i++) { |
| pt = mgcp_msg->codecs[i]; |
| codec = get_value_string_or_null(osmo_mgcpc_codec_names, pt); |
| |
| /* Note: Use codec descriptors from enum mgcp_codecs |
| * in mgcp_client only! */ |
| OSMO_ASSERT(codec); |
| rc += msgb_printf(msg, "%s", extract_codec_name(codec)); |
| if (i < mgcp_msg->codecs_len - 1) |
| rc += msgb_printf(msg, ";"); |
| } |
| rc += msgb_printf(msg, ","); |
| } |
| |
| rc += msgb_printf(msg, " nt:IN\r\n"); |
| |
| return rc; |
| } |
| |
| /* Helper function for mgcp_msg_gen(): Add SDP information to MGCP message */ |
| static int add_sdp(struct msgb *msg, struct mgcp_msg *mgcp_msg, struct mgcp_client *mgcp) |
| { |
| unsigned int i; |
| int rc = 0; |
| char local_ip[INET6_ADDRSTRLEN]; |
| int local_ip_family, audio_ip_family; |
| const char *codec; |
| unsigned int pt; |
| |
| /* Add separator to mark the beginning of the SDP block */ |
| rc += msgb_printf(msg, "\r\n"); |
| |
| /* Add SDP protocol version */ |
| rc += msgb_printf(msg, "v=0\r\n"); |
| |
| /* Determine local IP-Address */ |
| if (osmo_sock_local_ip(local_ip, mgcp->actual.remote_addr) < 0) { |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Could not determine local IP-Address!\n"); |
| msgb_free(msg); |
| return -2; |
| } |
| local_ip_family = osmo_ip_str_type(local_ip); |
| if (local_ip_family == AF_UNSPEC) { |
| msgb_free(msg); |
| return -2; |
| } |
| audio_ip_family = osmo_ip_str_type(mgcp_msg->audio_ip); |
| if (audio_ip_family == AF_UNSPEC) { |
| msgb_free(msg); |
| return -2; |
| } |
| |
| /* Add owner/creator (SDP) */ |
| rc += msgb_printf(msg, "o=- %x 23 IN IP%c %s\r\n", mgcp_msg->call_id, |
| local_ip_family == AF_INET6 ? '6' : '4', |
| local_ip); |
| |
| /* Add session name (none) */ |
| rc += msgb_printf(msg, "s=-\r\n"); |
| |
| /* Add RTP address and port */ |
| if (mgcp_msg->audio_port == 0) { |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Invalid port number, can not generate MGCP message\n"); |
| msgb_free(msg); |
| return -2; |
| } |
| if (strlen(mgcp_msg->audio_ip) <= 0) { |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Empty ip address, can not generate MGCP message\n"); |
| msgb_free(msg); |
| return -2; |
| } |
| rc += msgb_printf(msg, "c=IN IP%c %s\r\n", |
| audio_ip_family == AF_INET6 ? '6' : '4', |
| mgcp_msg->audio_ip); |
| |
| /* Add time description, active time (SDP) */ |
| rc += msgb_printf(msg, "t=0 0\r\n"); |
| |
| rc += msgb_printf(msg, "m=audio %u RTP/AVP", mgcp_msg->audio_port); |
| for (i = 0; i < mgcp_msg->codecs_len; i++) { |
| pt = map_codec_to_pt(mgcp_msg->ptmap, mgcp_msg->ptmap_len, mgcp_msg->codecs[i]); |
| rc += msgb_printf(msg, " %u", pt); |
| |
| } |
| rc += msgb_printf(msg, "\r\n"); |
| |
| /* Add optional codec parameters (fmtp) */ |
| if (mgcp_msg->param_present) { |
| for (i = 0; i < mgcp_msg->codecs_len; i++) { |
| /* The following is only applicable for AMR */ |
| if (mgcp_msg->codecs[i] != CODEC_AMR_8000_1 && mgcp_msg->codecs[i] != CODEC_AMRWB_16000_1) |
| continue; |
| pt = map_codec_to_pt(mgcp_msg->ptmap, mgcp_msg->ptmap_len, mgcp_msg->codecs[i]); |
| if (mgcp_msg->param.amr_octet_aligned_present && mgcp_msg->param.amr_octet_aligned) |
| rc += msgb_printf(msg, "a=fmtp:%u octet-align=1\r\n", pt); |
| else if (mgcp_msg->param.amr_octet_aligned_present && !mgcp_msg->param.amr_octet_aligned) |
| rc += msgb_printf(msg, "a=fmtp:%u octet-align=0\r\n", pt); |
| } |
| } |
| |
| for (i = 0; i < mgcp_msg->codecs_len; i++) { |
| pt = map_codec_to_pt(mgcp_msg->ptmap, mgcp_msg->ptmap_len, mgcp_msg->codecs[i]); |
| |
| /* Note: Only dynamic payload type from the range 96-127 |
| * require to be explained further via rtpmap. All others |
| * are implcitly definedby the number in m=audio */ |
| if (pt >= 96 && pt <= 127) { |
| codec = get_value_string_or_null(osmo_mgcpc_codec_names, mgcp_msg->codecs[i]); |
| |
| /* Note: Use codec descriptors from enum mgcp_codecs |
| * in mgcp_client only! */ |
| OSMO_ASSERT(codec); |
| |
| rc += msgb_printf(msg, "a=rtpmap:%u %s\r\n", pt, codec); |
| } |
| } |
| |
| if (mgcp_msg->ptime) |
| rc += msgb_printf(msg, "a=ptime:%u\r\n", mgcp_msg->ptime); |
| |
| return rc; |
| } |
| |
| /*! Generate an MGCP message |
| * \param[in] mgcp MGCP client descriptor. |
| * \param[in] mgcp_msg Message description |
| * \returns message buffer on success, NULL on error. */ |
| struct msgb *mgcp_msg_gen(struct mgcp_client *mgcp, struct mgcp_msg *mgcp_msg) |
| { |
| mgcp_trans_id_t trans_id = mgcp_client_next_trans_id(mgcp); |
| uint32_t mandatory_mask; |
| struct msgb *msg = msgb_alloc_headroom(4096, 128, "MGCP tx"); |
| int rc = 0; |
| int rc_sdp; |
| bool use_sdp = false; |
| char buf[32]; |
| |
| msg->l2h = msg->data; |
| msg->cb[MSGB_CB_MGCP_TRANS_ID] = trans_id; |
| |
| /* Add command verb */ |
| switch (mgcp_msg->verb) { |
| case MGCP_VERB_CRCX: |
| mandatory_mask = MGCP_CRCX_MANDATORY; |
| rc += msgb_printf(msg, "CRCX %u", trans_id); |
| break; |
| case MGCP_VERB_MDCX: |
| mandatory_mask = MGCP_MDCX_MANDATORY; |
| rc += msgb_printf(msg, "MDCX %u", trans_id); |
| break; |
| case MGCP_VERB_DLCX: |
| mandatory_mask = MGCP_DLCX_MANDATORY; |
| rc += msgb_printf(msg, "DLCX %u", trans_id); |
| break; |
| case MGCP_VERB_AUEP: |
| mandatory_mask = MGCP_AUEP_MANDATORY; |
| rc += msgb_printf(msg, "AUEP %u", trans_id); |
| break; |
| case MGCP_VERB_RSIP: |
| mandatory_mask = MGCP_RSIP_MANDATORY; |
| rc += msgb_printf(msg, "RSIP %u", trans_id); |
| break; |
| default: |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Invalid command verb, can not generate MGCP message\n"); |
| msgb_free(msg); |
| return NULL; |
| } |
| |
| /* Check if mandatory fields are missing */ |
| if (!((mgcp_msg->presence & mandatory_mask) == mandatory_mask)) { |
| LOGP(DLMGCP, LOGL_ERROR, |
| "One or more missing mandatory fields, can not generate MGCP message\n"); |
| msgb_free(msg); |
| return NULL; |
| } |
| |
| /* Add endpoint name */ |
| if (mgcp_msg->presence & MGCP_MSG_PRESENCE_ENDPOINT) { |
| if (strlen(mgcp_msg->endpoint) <= 0) { |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Empty endpoint name, can not generate MGCP message\n"); |
| msgb_free(msg); |
| return NULL; |
| } |
| |
| if (strstr(mgcp_msg->endpoint, "@") == NULL) { |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Endpoint name (%s) lacks separator (@), can not generate MGCP message\n", |
| mgcp_msg->endpoint); |
| msgb_free(msg); |
| return NULL; |
| } |
| |
| rc += msgb_printf(msg, " %s", mgcp_msg->endpoint); |
| } |
| |
| /* Add protocol version */ |
| rc += msgb_printf(msg, " MGCP 1.0\r\n"); |
| |
| /* Add call id */ |
| if (mgcp_msg->presence & MGCP_MSG_PRESENCE_CALL_ID) |
| rc += msgb_printf(msg, "C: %x\r\n", mgcp_msg->call_id); |
| |
| /* Add connection id */ |
| if (mgcp_msg->presence & MGCP_MSG_PRESENCE_CONN_ID) { |
| if (strlen(mgcp_msg->conn_id) <= 0) { |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Empty connection id, can not generate MGCP message\n"); |
| msgb_free(msg); |
| return NULL; |
| } |
| rc += msgb_printf(msg, "I: %s\r\n", mgcp_msg->conn_id); |
| } |
| |
| /* Using SDP makes sense when a valid IP/Port combination is specifiec, |
| * if we do not know this information yet, we fall back to LCO */ |
| if (mgcp_msg->presence & MGCP_MSG_PRESENCE_AUDIO_IP |
| && mgcp_msg->presence & MGCP_MSG_PRESENCE_AUDIO_PORT) |
| use_sdp = true; |
| |
| /* Add local connection options (LCO) */ |
| if (!use_sdp |
| && (mgcp_msg->verb == MGCP_VERB_CRCX |
| || mgcp_msg->verb == MGCP_VERB_MDCX)) |
| rc += add_lco(msg, mgcp_msg); |
| |
| /* Add mode */ |
| if (mgcp_msg->presence & MGCP_MSG_PRESENCE_CONN_MODE) |
| rc += |
| msgb_printf(msg, "M: %s\r\n", |
| mgcp_client_cmode_name(mgcp_msg->conn_mode)); |
| |
| /* Add X-Osmo-IGN */ |
| if ((mgcp_msg->presence & MGCP_MSG_PRESENCE_X_OSMO_IGN) |
| && (mgcp_msg->x_osmo_ign != 0)) |
| rc += |
| msgb_printf(msg, MGCP_X_OSMO_IGN_HEADER "%s\r\n", |
| mgcp_msg->x_osmo_ign & MGCP_X_OSMO_IGN_CALLID ? " C": ""); |
| |
| /* Add X-Osmo-Osmux */ |
| if ((mgcp_msg->presence & MGCP_MSG_PRESENCE_X_OSMO_OSMUX_CID)) { |
| if (mgcp_msg->x_osmo_osmux_cid < -1 || mgcp_msg->x_osmo_osmux_cid > OSMUX_CID_MAX) { |
| LOGP(DLMGCP, LOGL_ERROR, |
| "Wrong Osmux CID %d, can not generate MGCP message\n", |
| mgcp_msg->x_osmo_osmux_cid); |
| msgb_free(msg); |
| return NULL; |
| } |
| snprintf(buf, sizeof(buf), " %d", mgcp_msg->x_osmo_osmux_cid); |
| rc += |
| msgb_printf(msg, MGCP_X_OSMO_OSMUX_HEADER "%s\r\n", |
| mgcp_msg->x_osmo_osmux_cid == -1 ? " *": buf); |
| } |
| |
| |
| /* Add session description protocol (SDP) */ |
| if (use_sdp |
| && (mgcp_msg->verb == MGCP_VERB_CRCX |
| || mgcp_msg->verb == MGCP_VERB_MDCX)) { |
| rc_sdp = add_sdp(msg, mgcp_msg, mgcp); |
| if (rc_sdp == -2) |
| return NULL; |
| else |
| rc += rc_sdp; |
| } |
| |
| if (rc != 0) { |
| LOGP(DLMGCP, LOGL_ERROR, |
| "message buffer to small, can not generate MGCP message\n"); |
| msgb_free(msg); |
| msg = NULL; |
| } |
| |
| return msg; |
| } |
| |
| /*! Retrieve the MGCP transaction ID from a msgb generated by mgcp_msg_gen() |
| * \param[in] msg message buffer |
| * \returns Transaction id. */ |
| mgcp_trans_id_t mgcp_msg_trans_id(struct msgb *msg) |
| { |
| return (mgcp_trans_id_t)msg->cb[MSGB_CB_MGCP_TRANS_ID]; |
| } |
| |
| /*! Get the configuration parameters a given MGCP client instance |
| * \param[in] mgcp MGCP client descriptor. |
| * \returns configuration */ |
| struct mgcp_client_conf *mgcp_client_conf_actual(struct mgcp_client *mgcp) |
| { |
| return &mgcp->actual; |
| } |
| |
| const struct value_string mgcp_client_connection_mode_strs[] = { |
| { MGCP_CONN_NONE, "none" }, |
| { MGCP_CONN_RECV_SEND, "sendrecv" }, |
| { MGCP_CONN_SEND_ONLY, "sendonly" }, |
| { MGCP_CONN_RECV_ONLY, "recvonly" }, |
| { MGCP_CONN_LOOPBACK, "loopback" }, |
| { 0, NULL } |
| }; |