From 89579b4317a7f7ab6ee706399bee4b8f25a12c3a Mon Sep 17 00:00:00 2001 From: Harald Welte Date: Fri, 4 Mar 2011 13:18:30 +0100 Subject: prefix sub-directories containing libraries with 'lib' ... and make sure tests work again after restructuring --- openbsc/src/libtrau/rtp_proxy.c | 728 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 728 insertions(+) create mode 100644 openbsc/src/libtrau/rtp_proxy.c (limited to 'openbsc/src/libtrau/rtp_proxy.c') diff --git a/openbsc/src/libtrau/rtp_proxy.c b/openbsc/src/libtrau/rtp_proxy.c new file mode 100644 index 000000000..eefc0e1d6 --- /dev/null +++ b/openbsc/src/libtrau/rtp_proxy.c @@ -0,0 +1,728 @@ +/* RTP proxy handling for ip.access nanoBTS */ + +/* (C) 2009 by Harald Welte + * 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 . + * + */ + +#include +#include +#include +#include +#include +#include /* gettimeofday() */ +#include /* get..() */ +#include /* clock() */ +#include /* uname() */ + +#include +#include +#include +#include +#include +#include + +/* attempt to determine byte order */ +#include +#include +#include + +#ifndef __BYTE_ORDER +#error "__BYTE_ORDER should be defined by someone" +#endif + +static LLIST_HEAD(rtp_sockets); + +/* should we mangle the CNAME inside SDES of RTCP packets? We disable + * this by default, as it seems to be not needed */ +static int mangle_rtcp_cname = 0; + +enum rtp_bfd_priv { + RTP_PRIV_NONE, + RTP_PRIV_RTP, + RTP_PRIV_RTCP +}; + +#define RTP_ALLOC_SIZE 1500 + +/* according to RFC 1889 */ +struct rtcp_hdr { + u_int8_t byte0; + u_int8_t type; + u_int16_t length; +} __attribute__((packed)); + +#define RTCP_TYPE_SDES 202 + +#define RTCP_IE_CNAME 1 + +/* according to RFC 3550 */ +struct rtp_hdr { +#if __BYTE_ORDER == __LITTLE_ENDIAN + u_int8_t csrc_count:4, + extension:1, + padding:1, + version:2; + u_int8_t payload_type:7, + marker:1; +#elif __BYTE_ORDER == __BIG_ENDIAN + u_int8_t version:2, + padding:1, + extension:1, + csrc_count:4; + u_int8_t marker:1, + payload_type:7; +#endif + u_int16_t sequence; + u_int32_t timestamp; + u_int32_t ssrc; +} __attribute__((packed)); + +struct rtp_x_hdr { + u_int16_t by_profile; + u_int16_t length; +} __attribute__((packed)); + +#define RTP_VERSION 2 + +/* decode an rtp frame and create a new buffer with payload */ +static int rtp_decode(struct msgb *msg, u_int32_t callref, struct msgb **data) +{ + struct msgb *new_msg; + struct gsm_data_frame *frame; + struct rtp_hdr *rtph = (struct rtp_hdr *)msg->data; + struct rtp_x_hdr *rtpxh; + u_int8_t *payload; + int payload_len; + int msg_type; + int x_len; + + if (msg->len < 12) { + DEBUGPC(DMUX, "received RTP frame too short (len = %d)\n", + msg->len); + return -EINVAL; + } + if (rtph->version != RTP_VERSION) { + DEBUGPC(DMUX, "received RTP version %d not supported.\n", + rtph->version); + return -EINVAL; + } + payload = msg->data + sizeof(struct rtp_hdr) + (rtph->csrc_count << 2); + payload_len = msg->len - sizeof(struct rtp_hdr) - (rtph->csrc_count << 2); + if (payload_len < 0) { + DEBUGPC(DMUX, "received RTP frame too short (len = %d, " + "csrc count = %d)\n", msg->len, rtph->csrc_count); + return -EINVAL; + } + if (rtph->extension) { + if (payload_len < sizeof(struct rtp_x_hdr)) { + DEBUGPC(DMUX, "received RTP frame too short for " + "extension header\n"); + return -EINVAL; + } + rtpxh = (struct rtp_x_hdr *)payload; + x_len = ntohs(rtpxh->length) * 4 + sizeof(struct rtp_x_hdr); + payload += x_len; + payload_len -= x_len; + if (payload_len < 0) { + DEBUGPC(DMUX, "received RTP frame too short, " + "extension header exceeds frame length\n"); + return -EINVAL; + } + } + if (rtph->padding) { + if (payload_len < 0) { + DEBUGPC(DMUX, "received RTP frame too short for " + "padding length\n"); + return -EINVAL; + } + payload_len -= payload[payload_len - 1]; + if (payload_len < 0) { + DEBUGPC(DMUX, "received RTP frame with padding " + "greater than payload\n"); + return -EINVAL; + } + } + + switch (rtph->payload_type) { + case RTP_PT_GSM_FULL: + msg_type = GSM_TCHF_FRAME; + if (payload_len != 33) { + DEBUGPC(DMUX, "received RTP full rate frame with " + "payload length != 32 (len = %d)\n", + payload_len); + return -EINVAL; + } + break; + case RTP_PT_GSM_EFR: + msg_type = GSM_TCHF_FRAME_EFR; + break; + default: + DEBUGPC(DMUX, "received RTP frame with unknown payload " + "type %d\n", rtph->payload_type); + return -EINVAL; + } + + new_msg = msgb_alloc(sizeof(struct gsm_data_frame) + payload_len, + "GSM-DATA"); + if (!new_msg) + return -ENOMEM; + frame = (struct gsm_data_frame *)(new_msg->data); + frame->msg_type = msg_type; + frame->callref = callref; + memcpy(frame->data, payload, payload_len); + msgb_put(new_msg, sizeof(struct gsm_data_frame) + payload_len); + + *data = new_msg; + return 0; +} + +/* "to - from" */ +static void tv_difference(struct timeval *diff, const struct timeval *from, + const struct timeval *__to) +{ + struct timeval _to = *__to, *to = &_to; + + if (to->tv_usec < from->tv_usec) { + to->tv_sec -= 1; + to->tv_usec += 1000000; + } + + diff->tv_usec = to->tv_usec - from->tv_usec; + diff->tv_sec = to->tv_sec - from->tv_sec; +} + +/* encode and send a rtp frame */ +int rtp_send_frame(struct rtp_socket *rs, struct gsm_data_frame *frame) +{ + struct rtp_sub_socket *rss = &rs->rtp; + struct msgb *msg; + struct rtp_hdr *rtph; + int payload_type; + int payload_len; + int duration; /* in samples */ + + if (rs->tx_action != RTP_SEND_DOWNSTREAM) { + /* initialize sequences */ + rs->tx_action = RTP_SEND_DOWNSTREAM; + rs->transmit.ssrc = rand(); + rs->transmit.sequence = random(); + rs->transmit.timestamp = random(); + } + + switch (frame->msg_type) { + case GSM_TCHF_FRAME: + payload_type = RTP_PT_GSM_FULL; + payload_len = 33; + duration = 160; + break; + case GSM_TCHF_FRAME_EFR: + payload_type = RTP_PT_GSM_EFR; + payload_len = 31; + duration = 160; + break; + default: + DEBUGPC(DMUX, "unsupported message type %d\n", + frame->msg_type); + return -EINVAL; + } + + { + struct timeval tv, tv_diff; + long int usec_diff, frame_diff; + + gettimeofday(&tv, NULL); + tv_difference(&tv_diff, &rs->transmit.last_tv, &tv); + rs->transmit.last_tv = tv; + + usec_diff = tv_diff.tv_sec * 1000000 + tv_diff.tv_usec; + frame_diff = (usec_diff / 20000); + + if (abs(frame_diff) > 1) { + long int frame_diff_excess = frame_diff - 1; + + LOGP(DMUX, LOGL_NOTICE, + "Correcting frame difference of %ld frames\n", frame_diff_excess); + rs->transmit.sequence += frame_diff_excess; + rs->transmit.timestamp += frame_diff_excess * duration; + } + } + + msg = msgb_alloc(sizeof(struct rtp_hdr) + payload_len, "RTP-GSM-FULL"); + if (!msg) + return -ENOMEM; + rtph = (struct rtp_hdr *)msg->data; + rtph->version = RTP_VERSION; + rtph->padding = 0; + rtph->extension = 0; + rtph->csrc_count = 0; + rtph->marker = 0; + rtph->payload_type = payload_type; + rtph->sequence = htons(rs->transmit.sequence++); + rtph->timestamp = htonl(rs->transmit.timestamp); + rs->transmit.timestamp += duration; + rtph->ssrc = htonl(rs->transmit.ssrc); + memcpy(msg->data + sizeof(struct rtp_hdr), frame->data, payload_len); + msgb_put(msg, sizeof(struct rtp_hdr) + payload_len); + msgb_enqueue(&rss->tx_queue, msg); + rss->bfd.when |= BSC_FD_WRITE; + + return 0; +} + +/* iterate over all chunks in one RTCP message, look for CNAME IEs and + * replace all of those with 'new_cname' */ +static int rtcp_sdes_cname_mangle(struct msgb *msg, struct rtcp_hdr *rh, + u_int16_t *rtcp_len, const char *new_cname) +{ + u_int8_t *rtcp_end; + u_int8_t *cur = (u_int8_t *) rh; + u_int8_t tag, len = 0; + + rtcp_end = cur + *rtcp_len; + /* move cur to end of RTP header */ + cur += sizeof(*rh); + + /* iterate over Chunks */ + while (cur+4 < rtcp_end) { + /* skip four bytes SSRC/CSRC */ + cur += 4; + + /* iterate over IE's inside the chunk */ + while (cur+1 < rtcp_end) { + tag = *cur++; + if (tag == 0) { + /* end of chunk, skip additional zero */ + while (*cur++ == 0) { } + break; + } + len = *cur++; + + if (tag == RTCP_IE_CNAME) { + /* we've found the CNAME, lets mangle it */ + if (len < strlen(new_cname)) { + /* we need to make more space */ + int increase = strlen(new_cname) - len; + + msgb_push(msg, increase); + memmove(cur+len+increase, cur+len, + rtcp_end - (cur+len)); + /* FIXME: we have to respect RTCP + * padding/alignment rules! */ + len += increase; + *(cur-1) += increase; + rtcp_end += increase; + *rtcp_len += increase; + } + /* copy new CNAME into message */ + memcpy(cur, new_cname, strlen(new_cname)); + /* FIXME: zero the padding in case new CNAME + * is smaller than old one !!! */ + } + cur += len; + } + } + + return 0; +} + +static int rtcp_mangle(struct msgb *msg, struct rtp_socket *rs) +{ + struct rtp_sub_socket *rss = &rs->rtcp; + struct rtcp_hdr *rtph; + u_int16_t old_len; + int rc; + + if (!mangle_rtcp_cname) + return 0; + + printf("RTCP\n"); + /* iterate over list of RTCP messages */ + rtph = (struct rtcp_hdr *)msg->data; + while ((void *)rtph + sizeof(*rtph) <= (void *)msg->data + msg->len) { + old_len = (ntohs(rtph->length) + 1) * 4; + if ((void *)rtph + old_len > (void *)msg->data + msg->len) { + DEBUGPC(DMUX, "received RTCP packet too short for " + "length element\n"); + return -EINVAL; + } + if (rtph->type == RTCP_TYPE_SDES) { + char new_cname[255]; + strncpy(new_cname, inet_ntoa(rss->sin_local.sin_addr), + sizeof(new_cname)); + new_cname[sizeof(new_cname)-1] = '\0'; + rc = rtcp_sdes_cname_mangle(msg, rtph, &old_len, + new_cname); + if (rc < 0) + return rc; + } + rtph = (void *)rtph + old_len; + } + + return 0; +} + +/* read from incoming RTP/RTCP socket */ +static int rtp_socket_read(struct rtp_socket *rs, struct rtp_sub_socket *rss) +{ + int rc; + struct msgb *msg = msgb_alloc(RTP_ALLOC_SIZE, "RTP/RTCP"); + struct msgb *new_msg; + struct rtp_sub_socket *other_rss; + + if (!msg) + return -ENOMEM; + + rc = read(rss->bfd.fd, msg->data, RTP_ALLOC_SIZE); + if (rc <= 0) { + rss->bfd.when &= ~BSC_FD_READ; + return rc; + } + + msgb_put(msg, rc); + + switch (rs->rx_action) { + case RTP_PROXY: + if (!rs->proxy.other_sock) { + rc = -EIO; + goto out_free; + } + if (rss->bfd.priv_nr == RTP_PRIV_RTP) + other_rss = &rs->proxy.other_sock->rtp; + else if (rss->bfd.priv_nr == RTP_PRIV_RTCP) { + other_rss = &rs->proxy.other_sock->rtcp; + /* modify RTCP SDES CNAME */ + rc = rtcp_mangle(msg, rs); + if (rc < 0) + goto out_free; + } else { + rc = -EINVAL; + goto out_free; + } + msgb_enqueue(&other_rss->tx_queue, msg); + other_rss->bfd.when |= BSC_FD_WRITE; + break; + + case RTP_RECV_UPSTREAM: + if (!rs->receive.callref || !rs->receive.net) { + rc = -EIO; + goto out_free; + } + if (rss->bfd.priv_nr == RTP_PRIV_RTCP) { + if (!mangle_rtcp_cname) { + msgb_free(msg); + break; + } + /* modify RTCP SDES CNAME */ + rc = rtcp_mangle(msg, rs); + if (rc < 0) + goto out_free; + msgb_enqueue(&rss->tx_queue, msg); + rss->bfd.when |= BSC_FD_WRITE; + break; + } + if (rss->bfd.priv_nr != RTP_PRIV_RTP) { + rc = -EINVAL; + goto out_free; + } + rc = rtp_decode(msg, rs->receive.callref, &new_msg); + if (rc < 0) + goto out_free; + msgb_free(msg); + trau_tx_to_mncc(rs->receive.net, new_msg); + break; + + case RTP_NONE: /* if socket exists, but disabled by app */ + msgb_free(msg); + break; + } + + return 0; + +out_free: + msgb_free(msg); + return rc; +} + +/* write from tx_queue to RTP/RTCP socket */ +static int rtp_socket_write(struct rtp_socket *rs, struct rtp_sub_socket *rss) +{ + struct msgb *msg; + int written; + + msg = msgb_dequeue(&rss->tx_queue); + if (!msg) { + rss->bfd.when &= ~BSC_FD_WRITE; + return 0; + } + + written = write(rss->bfd.fd, msg->data, msg->len); + if (written < msg->len) { + LOGP(DMIB, LOGL_ERROR, "short write"); + msgb_free(msg); + return -EIO; + } + + msgb_free(msg); + + return 0; +} + + +/* callback for the select.c:bfd_* layer */ +static int rtp_bfd_cb(struct bsc_fd *bfd, unsigned int flags) +{ + struct rtp_socket *rs = bfd->data; + struct rtp_sub_socket *rss; + + switch (bfd->priv_nr) { + case RTP_PRIV_RTP: + rss = &rs->rtp; + break; + case RTP_PRIV_RTCP: + rss = &rs->rtcp; + break; + default: + return -EINVAL; + } + + if (flags & BSC_FD_READ) + rtp_socket_read(rs, rss); + + if (flags & BSC_FD_WRITE) + rtp_socket_write(rs, rss); + + return 0; +} + +static void init_rss(struct rtp_sub_socket *rss, + struct rtp_socket *rs, int fd, int priv_nr) +{ + /* initialize bfd */ + rss->bfd.fd = fd; + rss->bfd.data = rs; + rss->bfd.priv_nr = priv_nr; + rss->bfd.cb = rtp_bfd_cb; +} + +struct rtp_socket *rtp_socket_create(void) +{ + int rc; + struct rtp_socket *rs; + + DEBUGP(DMUX, "rtp_socket_create(): "); + + rs = talloc_zero(tall_bsc_ctx, struct rtp_socket); + if (!rs) + return NULL; + + INIT_LLIST_HEAD(&rs->rtp.tx_queue); + INIT_LLIST_HEAD(&rs->rtcp.tx_queue); + + rc = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP); + if (rc < 0) + goto out_free; + + init_rss(&rs->rtp, rs, rc, RTP_PRIV_RTP); + rc = bsc_register_fd(&rs->rtp.bfd); + if (rc < 0) + goto out_rtp_socket; + + rc = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP); + if (rc < 0) + goto out_rtp_bfd; + + init_rss(&rs->rtcp, rs, rc, RTP_PRIV_RTCP); + rc = bsc_register_fd(&rs->rtcp.bfd); + if (rc < 0) + goto out_rtcp_socket; + + DEBUGPC(DMUX, "success\n"); + + rc = rtp_socket_bind(rs, INADDR_ANY); + if (rc < 0) + goto out_rtcp_bfd; + + return rs; + +out_rtcp_bfd: + bsc_unregister_fd(&rs->rtcp.bfd); +out_rtcp_socket: + close(rs->rtcp.bfd.fd); +out_rtp_bfd: + bsc_unregister_fd(&rs->rtp.bfd); +out_rtp_socket: + close(rs->rtp.bfd.fd); +out_free: + talloc_free(rs); + DEBUGPC(DMUX, "failed\n"); + return NULL; +} + +static int rtp_sub_socket_bind(struct rtp_sub_socket *rss, u_int32_t ip, + u_int16_t port) +{ + int rc; + socklen_t alen = sizeof(rss->sin_local); + + rss->sin_local.sin_family = AF_INET; + rss->sin_local.sin_addr.s_addr = htonl(ip); + rss->sin_local.sin_port = htons(port); + rss->bfd.when |= BSC_FD_READ; + + rc = bind(rss->bfd.fd, (struct sockaddr *)&rss->sin_local, + sizeof(rss->sin_local)); + if (rc < 0) + return rc; + + /* retrieve the address we actually bound to, in case we + * passed INADDR_ANY as IP address */ + return getsockname(rss->bfd.fd, (struct sockaddr *)&rss->sin_local, + &alen); +} + +#define RTP_PORT_BASE 30000 +static unsigned int next_udp_port = RTP_PORT_BASE; + +/* bind a RTP socket to a local address */ +int rtp_socket_bind(struct rtp_socket *rs, u_int32_t ip) +{ + int rc = -EIO; + struct in_addr ia; + + ia.s_addr = htonl(ip); + DEBUGP(DMUX, "rtp_socket_bind(rs=%p, IP=%s): ", rs, + inet_ntoa(ia)); + + /* try to bind to a consecutive pair of ports */ + for (next_udp_port = next_udp_port % 0xffff; + next_udp_port < 0xffff; next_udp_port += 2) { + rc = rtp_sub_socket_bind(&rs->rtp, ip, next_udp_port); + if (rc != 0) + continue; + + rc = rtp_sub_socket_bind(&rs->rtcp, ip, next_udp_port+1); + if (rc == 0) + break; + } + if (rc < 0) { + DEBUGPC(DMUX, "failed\n"); + return rc; + } + + ia.s_addr = rs->rtp.sin_local.sin_addr.s_addr; + DEBUGPC(DMUX, "BOUND_IP=%s, BOUND_PORT=%u\n", + inet_ntoa(ia), ntohs(rs->rtp.sin_local.sin_port)); + return ntohs(rs->rtp.sin_local.sin_port); +} + +static int rtp_sub_socket_connect(struct rtp_sub_socket *rss, + u_int32_t ip, u_int16_t port) +{ + int rc; + socklen_t alen = sizeof(rss->sin_local); + + rss->sin_remote.sin_family = AF_INET; + rss->sin_remote.sin_addr.s_addr = htonl(ip); + rss->sin_remote.sin_port = htons(port); + + rc = connect(rss->bfd.fd, (struct sockaddr *) &rss->sin_remote, + sizeof(rss->sin_remote)); + if (rc < 0) + return rc; + + return getsockname(rss->bfd.fd, (struct sockaddr *)&rss->sin_local, + &alen); +} + +/* 'connect' a RTP socket to a remote peer */ +int rtp_socket_connect(struct rtp_socket *rs, u_int32_t ip, u_int16_t port) +{ + int rc; + struct in_addr ia; + + ia.s_addr = htonl(ip); + DEBUGP(DMUX, "rtp_socket_connect(rs=%p, ip=%s, port=%u)\n", + rs, inet_ntoa(ia), port); + + rc = rtp_sub_socket_connect(&rs->rtp, ip, port); + if (rc < 0) + return rc; + + return rtp_sub_socket_connect(&rs->rtcp, ip, port+1); +} + +/* bind two RTP/RTCP sockets together */ +int rtp_socket_proxy(struct rtp_socket *this, struct rtp_socket *other) +{ + DEBUGP(DMUX, "rtp_socket_proxy(this=%p, other=%p)\n", + this, other); + + this->rx_action = RTP_PROXY; + this->proxy.other_sock = other; + + other->rx_action = RTP_PROXY; + other->proxy.other_sock = this; + + return 0; +} + +/* bind RTP/RTCP socket to application */ +int rtp_socket_upstream(struct rtp_socket *this, struct gsm_network *net, + u_int32_t callref) +{ + DEBUGP(DMUX, "rtp_socket_proxy(this=%p, callref=%u)\n", + this, callref); + + if (callref) { + this->rx_action = RTP_RECV_UPSTREAM; + this->receive.net = net; + this->receive.callref = callref; + } else + this->rx_action = RTP_NONE; + + return 0; +} + +static void free_tx_queue(struct rtp_sub_socket *rss) +{ + struct msgb *msg; + + while ((msg = msgb_dequeue(&rss->tx_queue))) + msgb_free(msg); +} + +int rtp_socket_free(struct rtp_socket *rs) +{ + DEBUGP(DMUX, "rtp_socket_free(rs=%p)\n", rs); + + /* make sure we don't leave references dangling to us */ + if (rs->rx_action == RTP_PROXY && + rs->proxy.other_sock) + rs->proxy.other_sock->proxy.other_sock = NULL; + + bsc_unregister_fd(&rs->rtp.bfd); + close(rs->rtp.bfd.fd); + free_tx_queue(&rs->rtp); + + bsc_unregister_fd(&rs->rtcp.bfd); + close(rs->rtcp.bfd.fd); + free_tx_queue(&rs->rtcp); + + talloc_free(rs); + + return 0; +} -- cgit v1.2.3