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