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