1386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari/* 2386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari * rtp.c 3386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari * 4386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari * library functions for the real-time transport protocol 5386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari * 6386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari * David A. McGrew 7386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari * Cisco Systems, Inc. 8386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari */ 9386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 10386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 11386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari#include "rtp_priv.h" 12386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 13386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari#include <stdio.h> 14386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari#include <string.h> 15386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 16386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari#include <sys/types.h> 17386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari#ifdef HAVE_SYS_SOCKET_H 18386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari# include <sys/socket.h> 19386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari#endif 20386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 21386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari#define PRINT_DEBUG 0 /* set to 1 to print out debugging data */ 22386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari#define VERBOSE_DEBUG 0 /* set to 1 to print out more data */ 23386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 24386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagariunsigned int 25386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagarirtp_sendto(rtp_sender_t sender, const void* msg, int len) { 26386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari int octets_sent; 27386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari err_status_t stat; 28386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari int pkt_len = len + RTP_HEADER_LEN; 29386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 30386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari /* marshal data */ 31386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari strncpy(sender->message.body, msg, len); 32386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 33386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari /* update header */ 34386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari sender->message.header.seq = ntohs(sender->message.header.seq) + 1; 35386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari sender->message.header.seq = htons(sender->message.header.seq); 36386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari sender->message.header.ts = ntohl(sender->message.header.ts) + 1; 37386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari sender->message.header.ts = htonl(sender->message.header.ts); 38386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 39386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari /* apply srtp */ 40386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari stat = srtp_protect(sender->srtp_ctx, &sender->message.header, &pkt_len); 41386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari if (stat) { 42386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari#if PRINT_DEBUG 43386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari fprintf(stderr, "error: srtp protection failed with code %d\n", stat); 44386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari#endif 45386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari return -1; 46386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari } 47386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari#if VERBOSE_DEBUG 48386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari srtp_print_packet(&sender->message.header, pkt_len); 49386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari#endif 50386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari octets_sent = sendto(sender->socket, (void*)&sender->message, 51386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari pkt_len, 0, (struct sockaddr *)&sender->addr, 52386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari sizeof (struct sockaddr_in)); 53386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 54386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari if (octets_sent != pkt_len) { 55386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari#if PRINT_DEBUG 56386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari fprintf(stderr, "error: couldn't send message %s", (char *)msg); 57386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari perror(""); 58386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari#endif 59386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari } 60386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 61386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari return octets_sent; 62386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari} 63386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 64386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagariunsigned int 65386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagarirtp_recvfrom(rtp_receiver_t receiver, void *msg, int *len) { 66386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari int octets_recvd; 67386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari err_status_t stat; 68386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 69386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari octets_recvd = recvfrom(receiver->socket, (void *)&receiver->message, 70386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari *len, 0, (struct sockaddr *) NULL, 0); 71386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 72386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari /* verify rtp header */ 73386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari if (receiver->message.header.version != 2) { 74386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari *len = 0; 75386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari return -1; 76386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari } 77386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 78386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari#if PRINT_DEBUG 79386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari fprintf(stderr, "%d octets received from SSRC %u\n", 80386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari octets_recvd, receiver->message.header.ssrc); 81386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari#endif 82386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari#if VERBOSE_DEBUG 83386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari srtp_print_packet(&receiver->message.header, octets_recvd); 84386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari#endif 85386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 86386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari /* apply srtp */ 87386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari stat = srtp_unprotect(receiver->srtp_ctx, 88386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari &receiver->message.header, &octets_recvd); 89386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari if (stat) { 90386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari fprintf(stderr, 91386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari "error: srtp unprotection failed with code %d%s\n", stat, 92386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari stat == err_status_replay_fail ? " (replay check failed)" : 93386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari stat == err_status_auth_fail ? " (auth check failed)" : ""); 94386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari return -1; 95386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari } 96386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari strncpy(msg, receiver->message.body, octets_recvd); 97386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 98386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari return octets_recvd; 99386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari} 100386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 101386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagariint 102386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagarirtp_sender_init(rtp_sender_t sender, 103386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari int socket, 104386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari struct sockaddr_in addr, 105386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari unsigned int ssrc) { 106386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 107386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari /* set header values */ 108386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari sender->message.header.ssrc = htonl(ssrc); 109386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari sender->message.header.ts = 0; 110386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari sender->message.header.seq = (uint16_t) rand(); 111386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari sender->message.header.m = 0; 112386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari sender->message.header.pt = 0x1; 113386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari sender->message.header.version = 2; 114386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari sender->message.header.p = 0; 115386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari sender->message.header.x = 0; 116386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari sender->message.header.cc = 0; 117386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 118386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari /* set other stuff */ 119386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari sender->socket = socket; 120386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari sender->addr = addr; 121386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 122386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari return 0; 123386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari} 124386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 125386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagariint 126386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagarirtp_receiver_init(rtp_receiver_t rcvr, 127386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari int socket, 128386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari struct sockaddr_in addr, 129386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari unsigned int ssrc) { 130386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 131386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari /* set header values */ 132386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari rcvr->message.header.ssrc = htonl(ssrc); 133386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari rcvr->message.header.ts = 0; 134386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari rcvr->message.header.seq = 0; 135386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari rcvr->message.header.m = 0; 136386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari rcvr->message.header.pt = 0x1; 137386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari rcvr->message.header.version = 2; 138386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari rcvr->message.header.p = 0; 139386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari rcvr->message.header.x = 0; 140386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari rcvr->message.header.cc = 0; 141386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 142386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari /* set other stuff */ 143386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari rcvr->socket = socket; 144386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari rcvr->addr = addr; 145386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 146386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari return 0; 147386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari} 148386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 149386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagariint 150386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagarirtp_sender_init_srtp(rtp_sender_t sender, const srtp_policy_t *policy) { 151386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari return srtp_create(&sender->srtp_ctx, policy); 152386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari} 153386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 154386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagariint 155386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagarirtp_receiver_init_srtp(rtp_receiver_t sender, const srtp_policy_t *policy) { 156386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari return srtp_create(&sender->srtp_ctx, policy); 157386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari} 158386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 159386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagarirtp_sender_t 160386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagarirtp_sender_alloc() { 161386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari return (rtp_sender_t)malloc(sizeof(rtp_sender_ctx_t)); 162386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari} 163386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari 164386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagarirtp_receiver_t 165386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagarirtp_receiver_alloc() { 166386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari return (rtp_receiver_t)malloc(sizeof(rtp_receiver_ctx_t)); 167386ce4d9144fc190797f4e43a31aeaf76ca2e373Param Reddappagari} 168