src/modules/rtp/sap.c

   1 /***
   2   This file is part of PulseAudio.
   3
   4   Copyright 2006 Lennart Poettering
   5
   6   PulseAudio is free software; you can redistribute it and/or modify
   7   it under the terms of the GNU Lesser General Public License as published
   8   by the Free Software Foundation; either version 2.1 of the License,
   9   or (at your option) any later version.
  10
  11   PulseAudio is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with PulseAudio; if not, write to the Free Software
  18   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  19   USA.
  20 ***/
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include <time.h>
  27 #include <stdlib.h>
  28 #include <sys/types.h>
  29 #include <sys/socket.h>
  30 #include <netinet/in.h>
  31 #include <arpa/inet.h>
  32 #include <errno.h>
  33 #include <string.h>
  34 #include <unistd.h>
  35 #include <sys/ioctl.h>
  36
  37 #ifdef HAVE_SYS_FILIO_H
  38 #include <sys/filio.h>
  39 #endif
  40
  41 #ifdef HAVE_SYS_UIO_H
  42 #include <sys/uio.h>
  43 #endif
  44
  45 #include <pulse/xmalloc.h>
  46
  47 #include <pulsecore/core-error.h>
  48 #include <pulsecore/core-util.h>
  49 #include <pulsecore/log.h>
  50 #include <pulsecore/macro.h>
  51
  52 #include "sap.h"
  53 #include "sdp.h"
  54
  55 #define MIME_TYPE "application/sdp"
  56
  57 pa_sap_context* pa_sap_context_init_send(pa_sap_context *c, int fd, char *sdp_data) {
  58     pa_assert(c);
  59     pa_assert(fd >= 0);
  60     pa_assert(sdp_data);
  61
  62     c->fd = fd;
  63     c->sdp_data = sdp_data;
  64     c->msg_id_hash = (uint16_t) (rand()*rand());
  65
  66     return c;
  67 }
  68
  69 void pa_sap_context_destroy(pa_sap_context *c) {
  70     pa_assert(c);
  71
  72     pa_close(c->fd);
  73     pa_xfree(c->sdp_data);
  74 }
  75
  76 int pa_sap_send(pa_sap_context *c, pa_bool_t goodbye) {
  77     uint32_t header;
  78     struct sockaddr_storage sa_buf;
  79     struct sockaddr *sa = (struct sockaddr*) &sa_buf;
  80     socklen_t salen = sizeof(sa_buf);
  81     struct iovec iov[4];
  82     struct msghdr m;
  83     ssize_t k;
  84
  85     if (getsockname(c->fd, sa, &salen) < 0) {
  86         pa_log("getsockname() failed: %s\n", pa_cstrerror(errno));
  87         return -1;
  88     }
  89
  90 #ifdef HAVE_IPV6
  91     pa_assert(sa->sa_family == AF_INET || sa->sa_family == AF_INET6);
  92 #else
  93     pa_assert(sa->sa_family == AF_INET);
  94 #endif
  95
  96     header = htonl(((uint32_t) 1 << 29) |
  97 #ifdef HAVE_IPV6
  98                    (sa->sa_family == AF_INET6 ? (uint32_t) 1 << 28 : 0) |
  99 #endif
 100                    (goodbye ? (uint32_t) 1 << 26 : 0) |
 101                    (c->msg_id_hash));
 102
 103     iov[0].iov_base = &header;
 104     iov[0].iov_len = sizeof(header);
 105
 106     if (sa->sa_family == AF_INET) {
 107         iov[1].iov_base = (void*) &((struct sockaddr_in*) sa)->sin_addr;
 108         iov[1].iov_len = 4U;
 109 #ifdef HAVE_IPV6
 110     } else {
 111         iov[1].iov_base = (void*) &((struct sockaddr_in6*) sa)->sin6_addr;
 112         iov[1].iov_len = 16U;
 113 #endif
 114     }
 115
 116     iov[2].iov_base = (char*) MIME_TYPE;
 117     iov[2].iov_len = sizeof(MIME_TYPE);
 118
 119     iov[3].iov_base = c->sdp_data;
 120     iov[3].iov_len = strlen(c->sdp_data);
 121
 122     m.msg_name = NULL;
 123     m.msg_namelen = 0;
 124     m.msg_iov = iov;
 125     m.msg_iovlen = 4;
 126     m.msg_control = NULL;
 127     m.msg_controllen = 0;
 128     m.msg_flags = 0;
 129
 130     if ((k = sendmsg(c->fd, &m, MSG_DONTWAIT)) < 0)
 131         pa_log_warn("sendmsg() failed: %s\n", pa_cstrerror(errno));
 132
 133     return (int) k;
 134 }
 135
 136 pa_sap_context* pa_sap_context_init_recv(pa_sap_context *c, int fd) {
 137     pa_assert(c);
 138     pa_assert(fd >= 0);
 139
 140     c->fd = fd;
 141     c->sdp_data = NULL;
 142     return c;
 143 }
 144
 145 int pa_sap_recv(pa_sap_context *c, pa_bool_t *goodbye) {
 146     struct msghdr m;
 147     struct iovec iov;
 148     int size;
 149     char *buf = NULL, *e;
 150     uint32_t header;
 151     unsigned six, ac, k;
 152     ssize_t r;
 153
 154     pa_assert(c);
 155     pa_assert(goodbye);
 156
 157     if (ioctl(c->fd, FIONREAD, &size) < 0) {
 158         pa_log_warn("FIONREAD failed: %s", pa_cstrerror(errno));
 159         goto fail;
 160     }
 161
 162     buf = pa_xnew(char, (unsigned) size+1);
 163     buf[size] = 0;
 164
 165     iov.iov_base = buf;
 166     iov.iov_len = (size_t) size;
 167
 168     m.msg_name = NULL;
 169     m.msg_namelen = 0;
 170     m.msg_iov = &iov;
 171     m.msg_iovlen = 1;
 172     m.msg_control = NULL;
 173     m.msg_controllen = 0;
 174     m.msg_flags = 0;
 175
 176     if ((r = recvmsg(c->fd, &m, 0)) != size) {
 177         pa_log_warn("recvmsg() failed: %s", r < 0 ? pa_cstrerror(errno) : "size mismatch");
 178         goto fail;
 179     }
 180
 181     if (size < 4) {
 182         pa_log_warn("SAP packet too short.");
 183         goto fail;
 184     }
 185
 186     memcpy(&header, buf, sizeof(uint32_t));
 187     header = ntohl(header);
 188
 189     if (header >> 29 != 1) {
 190         pa_log_warn("Unsupported SAP version.");
 191         goto fail;
 192     }
 193
 194     if ((header >> 25) & 1) {
 195         pa_log_warn("Encrypted SAP not supported.");
 196         goto fail;
 197     }
 198
 199     if ((header >> 24) & 1) {
 200         pa_log_warn("Compressed SAP not supported.");
 201         goto fail;
 202     }
 203
 204     six = (header >> 28) & 1U;
 205     ac = (header >> 16) & 0xFFU;
 206
 207     k = 4 + (six ? 16U : 4U) + ac*4U;
 208     if ((unsigned) size < k) {
 209         pa_log_warn("SAP packet too short (AD).");
 210         goto fail;
 211     }
 212
 213     e = buf + k;
 214     size -= (int) k;
 215
 216     if ((unsigned) size >= sizeof(MIME_TYPE) && !strcmp(e, MIME_TYPE)) {
 217         e += sizeof(MIME_TYPE);
 218         size -= (int) sizeof(MIME_TYPE);
 219     } else if ((unsigned) size < sizeof(PA_SDP_HEADER)-1 || strncmp(e, PA_SDP_HEADER, sizeof(PA_SDP_HEADER)-1)) {
 220         pa_log_warn("Invalid SDP header.");
 221         goto fail;
 222     }
 223
 224     if (c->sdp_data)
 225         pa_xfree(c->sdp_data);
 226
 227     c->sdp_data = pa_xstrndup(e, (unsigned) size);
 228     pa_xfree(buf);
 229
 230     *goodbye = !!((header >> 26) & 1);
 231
 232     return 0;
 233
 234 fail:
 235     pa_xfree(buf);
 236
 237     return -1;
 238 }