| /* |
| * rtp.c |
| * |
| * library functions for the real-time transport protocol |
| * |
| * David A. McGrew |
| * Cisco Systems, Inc. |
| */ |
| |
| /* |
| * |
| * Copyright (c) 2001-2017, Cisco Systems, Inc. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following |
| * disclaimer in the documentation and/or other materials provided |
| * with the distribution. |
| * |
| * Neither the name of the Cisco Systems, Inc. nor the names of its |
| * contributors may be used to endorse or promote products derived |
| * from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, |
| * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
| * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED |
| * OF THE POSSIBILITY OF SUCH DAMAGE. |
| * |
| */ |
| |
| #include "rtp.h" |
| |
| #include <stdio.h> |
| #include <string.h> |
| |
| #include <sys/types.h> |
| #ifdef HAVE_SYS_SOCKET_H |
| #include <sys/socket.h> |
| #endif |
| |
| #include "cipher_priv.h" |
| |
| #define PRINT_DEBUG 0 /* set to 1 to print out debugging data */ |
| #define VERBOSE_DEBUG 0 /* set to 1 to print out more data */ |
| |
| int rtp_sendto(rtp_sender_t sender, const void *msg, int len) |
| { |
| int octets_sent; |
| srtp_err_status_t stat; |
| int pkt_len = len + RTP_HEADER_LEN; |
| |
| /* marshal data */ |
| strncpy(sender->message.body, msg, len); |
| |
| /* update header */ |
| sender->message.header.seq = ntohs(sender->message.header.seq) + 1; |
| sender->message.header.seq = htons(sender->message.header.seq); |
| sender->message.header.ts = ntohl(sender->message.header.ts) + 1; |
| sender->message.header.ts = htonl(sender->message.header.ts); |
| |
| /* apply srtp */ |
| stat = srtp_protect(sender->srtp_ctx, &sender->message.header, &pkt_len); |
| if (stat) { |
| #if PRINT_DEBUG |
| fprintf(stderr, "error: srtp protection failed with code %d\n", stat); |
| #endif |
| return -1; |
| } |
| #if VERBOSE_DEBUG |
| srtp_print_packet(&sender->message.header, pkt_len); |
| #endif |
| octets_sent = |
| sendto(sender->socket, (void *)&sender->message, pkt_len, 0, |
| (struct sockaddr *)&sender->addr, sizeof(struct sockaddr_in)); |
| |
| if (octets_sent != pkt_len) { |
| #if PRINT_DEBUG |
| fprintf(stderr, "error: couldn't send message %s", (char *)msg); |
| perror(""); |
| #endif |
| } |
| |
| return octets_sent; |
| } |
| |
| int rtp_recvfrom(rtp_receiver_t receiver, void *msg, int *len) |
| { |
| int octets_recvd; |
| srtp_err_status_t stat; |
| |
| octets_recvd = recvfrom(receiver->socket, (void *)&receiver->message, *len, |
| 0, (struct sockaddr *)NULL, 0); |
| |
| if (octets_recvd == -1) { |
| *len = 0; |
| return -1; |
| } |
| |
| /* verify rtp header */ |
| if (receiver->message.header.version != 2) { |
| *len = 0; |
| return -1; |
| } |
| |
| #if PRINT_DEBUG |
| fprintf(stderr, "%d octets received from SSRC %u\n", octets_recvd, |
| receiver->message.header.ssrc); |
| #endif |
| #if VERBOSE_DEBUG |
| srtp_print_packet(&receiver->message.header, octets_recvd); |
| #endif |
| |
| /* apply srtp */ |
| stat = srtp_unprotect(receiver->srtp_ctx, &receiver->message.header, |
| &octets_recvd); |
| if (stat) { |
| fprintf(stderr, "error: srtp unprotection failed with code %d%s\n", |
| stat, |
| stat == srtp_err_status_replay_fail |
| ? " (replay check failed)" |
| : stat == srtp_err_status_auth_fail ? " (auth check failed)" |
| : ""); |
| return -1; |
| } |
| strncpy(msg, receiver->message.body, octets_recvd); |
| |
| return octets_recvd; |
| } |
| |
| int rtp_sender_init(rtp_sender_t sender, |
| int sock, |
| struct sockaddr_in addr, |
| unsigned int ssrc) |
| { |
| /* set header values */ |
| sender->message.header.ssrc = htonl(ssrc); |
| sender->message.header.ts = 0; |
| sender->message.header.seq = (uint16_t)srtp_cipher_rand_u32_for_tests(); |
| sender->message.header.m = 0; |
| sender->message.header.pt = 0x1; |
| sender->message.header.version = 2; |
| sender->message.header.p = 0; |
| sender->message.header.x = 0; |
| sender->message.header.cc = 0; |
| |
| /* set other stuff */ |
| sender->socket = sock; |
| sender->addr = addr; |
| |
| return 0; |
| } |
| |
| int rtp_receiver_init(rtp_receiver_t rcvr, |
| int sock, |
| struct sockaddr_in addr, |
| unsigned int ssrc) |
| { |
| /* set header values */ |
| rcvr->message.header.ssrc = htonl(ssrc); |
| rcvr->message.header.ts = 0; |
| rcvr->message.header.seq = 0; |
| rcvr->message.header.m = 0; |
| rcvr->message.header.pt = 0x1; |
| rcvr->message.header.version = 2; |
| rcvr->message.header.p = 0; |
| rcvr->message.header.x = 0; |
| rcvr->message.header.cc = 0; |
| |
| /* set other stuff */ |
| rcvr->socket = sock; |
| rcvr->addr = addr; |
| |
| return 0; |
| } |
| |
| int rtp_sender_init_srtp(rtp_sender_t sender, const srtp_policy_t *policy) |
| { |
| return srtp_create(&sender->srtp_ctx, policy); |
| } |
| |
| int rtp_sender_deinit_srtp(rtp_sender_t sender) |
| { |
| return srtp_dealloc(sender->srtp_ctx); |
| } |
| |
| int rtp_receiver_init_srtp(rtp_receiver_t sender, const srtp_policy_t *policy) |
| { |
| return srtp_create(&sender->srtp_ctx, policy); |
| } |
| |
| int rtp_receiver_deinit_srtp(rtp_receiver_t sender) |
| { |
| return srtp_dealloc(sender->srtp_ctx); |
| } |
| |
| rtp_sender_t rtp_sender_alloc(void) |
| { |
| return (rtp_sender_t)malloc(sizeof(rtp_sender_ctx_t)); |
| } |
| |
| void rtp_sender_dealloc(rtp_sender_t rtp_ctx) |
| { |
| free(rtp_ctx); |
| } |
| |
| rtp_receiver_t rtp_receiver_alloc(void) |
| { |
| return (rtp_receiver_t)malloc(sizeof(rtp_receiver_ctx_t)); |
| } |
| |
| void rtp_receiver_dealloc(rtp_receiver_t rtp_ctx) |
| { |
| free(rtp_ctx); |
| } |