code.delx.au - pulseaudio/blob - src/modules/rtp/sap.c

   1 /* $Id$ */
   2
   3 /***
   4   This file is part of polypaudio.
   5
   6   polypaudio 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 of the License,
   9   or (at your option) any later version.
  10
  11   polypaudio 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 polypaudio; 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 <assert.h>
  27 #include <time.h>
  28 #include <stdlib.h>
  29 #include <sys/types.h>
  30 #include <sys/socket.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 #include <polyp/error.h>
  42 #include <polyp/xmalloc.h>
  43
  44 #include <polypcore/core-util.h>
  45 #include <polypcore/log.h>
  46
  47 #include "sap.h"
  48 #include "sdp.h"
  49
  50 #define MIME_TYPE "application/sdp"
  51
  52 pa_sap_context* pa_sap_context_init_send(pa_sap_context *c, int fd, char *sdp_data) {
  53     assert(c);
  54     assert(fd >= 0);
  55     assert(sdp_data);
  56
  57     c->fd = fd;
  58     c->sdp_data = sdp_data;
  59     c->msg_id_hash = (uint16_t) (rand()*rand());
  60
  61     return c;
  62 }
  63
  64 void pa_sap_context_destroy(pa_sap_context *c) {
  65     assert(c);
  66
  67     close(c->fd);
  68     pa_xfree(c->sdp_data);
  69 }
  70
  71 int pa_sap_send(pa_sap_context *c, int goodbye) {
  72     uint32_t header;
  73     struct sockaddr_storage sa_buf;
  74     struct sockaddr *sa = (struct sockaddr*) &sa_buf;
  75     socklen_t salen = sizeof(sa_buf);
  76     struct iovec iov[4];
  77     struct msghdr m;
  78     int k;
  79
  80     if (getsockname(c->fd, sa, &salen) < 0) {
  81         pa_log("getsockname() failed: %s\n", pa_cstrerror(errno));
  82         return -1;
  83     }
  84
  85     assert(sa->sa_family == AF_INET || sa->sa_family == AF_INET6);
  86
  87     header = htonl(((uint32_t) 1 << 29) |
  88                    (sa->sa_family == AF_INET6 ? (uint32_t) 1 << 28 : 0) |
  89                    (goodbye ? (uint32_t) 1 << 26 : 0) |
  90                    (c->msg_id_hash));
  91
  92     iov[0].iov_base = &header;
  93     iov[0].iov_len = sizeof(header);
  94
  95     iov[1].iov_base = sa->sa_family == AF_INET ? (void*) &((struct sockaddr_in*) sa)->sin_addr : (void*) &((struct sockaddr_in6*) sa)->sin6_addr;
  96     iov[1].iov_len = sa->sa_family == AF_INET ? 4 : 16;
  97
  98     iov[2].iov_base = (char*) MIME_TYPE;
  99     iov[2].iov_len = sizeof(MIME_TYPE);
 100
 101     iov[3].iov_base = c->sdp_data;
 102     iov[3].iov_len = strlen(c->sdp_data);
 103
 104     m.msg_name = NULL;
 105     m.msg_namelen = 0;
 106     m.msg_iov = iov;
 107     m.msg_iovlen = 4;
 108     m.msg_control = NULL;
 109     m.msg_controllen = 0;
 110     m.msg_flags = 0;
 111
 112     if ((k = sendmsg(c->fd, &m, MSG_DONTWAIT)) < 0)
 113         pa_log("sendmsg() failed: %s\n", pa_cstrerror(errno));
 114
 115     return k;
 116 }
 117
 118 pa_sap_context* pa_sap_context_init_recv(pa_sap_context *c, int fd) {
 119     assert(c);
 120     assert(fd >= 0);
 121
 122     c->fd = fd;
 123     c->sdp_data = NULL;
 124     return c;
 125 }
 126
 127 int pa_sap_recv(pa_sap_context *c, int *goodbye) {
 128     struct msghdr m;
 129     struct iovec iov;
 130     int size, k;
 131     char *buf = NULL, *e;
 132     uint32_t header;
 133     int six, ac;
 134     ssize_t r;
 135
 136     assert(c);
 137     assert(goodbye);
 138
 139     if (ioctl(c->fd, FIONREAD, &size) < 0) {
 140         pa_log(__FILE__": FIONREAD failed: %s", pa_cstrerror(errno));
 141         goto fail;
 142     }
 143
 144     if (!size)
 145         return 0;
 146
 147     buf = pa_xnew(char, size+1);
 148     buf[size] = 0;
 149
 150     iov.iov_base = buf;
 151     iov.iov_len = size;
 152
 153     m.msg_name = NULL;
 154     m.msg_namelen = 0;
 155     m.msg_iov = &iov;
 156     m.msg_iovlen = 1;
 157     m.msg_control = NULL;
 158     m.msg_controllen = 0;
 159     m.msg_flags = 0;
 160
 161     if ((r = recvmsg(c->fd, &m, 0)) != size) {
 162         pa_log(__FILE__": recvmsg() failed: %s", r < 0 ? pa_cstrerror(errno) : "size mismatch");
 163         goto fail;
 164     }
 165
 166     if (size < 4) {
 167         pa_log(__FILE__": SAP packet too short.");
 168         goto fail;
 169     }
 170
 171     memcpy(&header, buf, sizeof(uint32_t));
 172     header = ntohl(header);
 173
 174     if (header >> 29 != 1) {
 175         pa_log(__FILE__": Unsupported SAP version.");
 176         goto fail;
 177     }
 178
 179     if ((header >> 25) & 1) {
 180         pa_log(__FILE__": Encrypted SAP not supported.");
 181         goto fail;
 182     }
 183
 184     if ((header >> 24) & 1) {
 185         pa_log(__FILE__": Compressed SAP not supported.");
 186         goto fail;
 187     }
 188
 189     six = (header >> 28) & 1;
 190     ac = (header >> 16) & 0xFF;
 191
 192     k = 4 + (six ? 16 : 4) + ac*4;
 193     if (size < k) {
 194         pa_log(__FILE__": SAP packet too short (AD).");
 195         goto fail;
 196     }
 197
 198     e = buf + k;
 199     size -= k;
 200
 201     if ((unsigned) size >= sizeof(MIME_TYPE) && !strcmp(e, MIME_TYPE)) {
 202         e += sizeof(MIME_TYPE);
 203         size -= sizeof(MIME_TYPE);
 204     } else if ((unsigned) size < sizeof(PA_SDP_HEADER)-1 || strncmp(e, PA_SDP_HEADER, sizeof(PA_SDP_HEADER)-1)) {
 205         pa_log(__FILE__": Invalid SDP header.");
 206         goto fail;
 207     }
 208
 209     if (c->sdp_data)
 210         pa_xfree(c->sdp_data);
 211
 212     c->sdp_data = pa_xstrndup(e, size);
 213     pa_xfree(buf);
 214
 215     *goodbye = !!((header >> 26) & 1);
 216
 217     return 0;
 218
 219 fail:
 220     pa_xfree(buf);
 221
 222     return -1;
 223 }