code.delx.au - pulseaudio/blob - 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 <stdlib.h>
  27 #include <sys/types.h>
  28 #include <sys/socket.h>
  29 #include <netinet/in.h>
  30 #include <errno.h>
  31 #include <string.h>
  32 #include <unistd.h>
  33 #include <sys/ioctl.h>
  34
  35 #ifdef HAVE_SYS_FILIO_H
  36 #include <sys/filio.h>
  37 #endif
  38
  39 #ifdef HAVE_SYS_UIO_H
  40 #include <sys/uio.h>
  41 #endif
  42
  43 #include <pulse/xmalloc.h>
  44
  45 #include <pulsecore/core-error.h>
  46 #include <pulsecore/core-util.h>
  47 #include <pulsecore/log.h>
  48 #include <pulsecore/macro.h>
  49 #include <pulsecore/arpa-inet.h>
  50
  51 #include "sap.h"
  52 #include "sdp.h"
  53
  54 #define MIME_TYPE "application/sdp"
  55
  56 pa_sap_context* pa_sap_context_init_send(pa_sap_context *c, int fd, char *sdp_data) {
  57     pa_assert(c);
  58     pa_assert(fd >= 0);
  59     pa_assert(sdp_data);
  60
  61     c->fd = fd;
  62     c->sdp_data = sdp_data;
  63     c->msg_id_hash = (uint16_t) (rand()*rand());
  64
  65     return c;
  66 }
  67
  68 void pa_sap_context_destroy(pa_sap_context *c) {
  69     pa_assert(c);
  70
  71     pa_close(c->fd);
  72     pa_xfree(c->sdp_data);
  73 }
  74
  75 int pa_sap_send(pa_sap_context *c, bool goodbye) {
  76     uint32_t header;
  77     struct sockaddr_storage sa_buf;
  78     struct sockaddr *sa = (struct sockaddr*) &sa_buf;
  79     socklen_t salen = sizeof(sa_buf);
  80     struct iovec iov[4];
  81     struct msghdr m;
  82     ssize_t k;
  83
  84     if (getsockname(c->fd, sa, &salen) < 0) {
  85         pa_log("getsockname() failed: %s\n", pa_cstrerror(errno));
  86         return -1;
  87     }
  88
  89 #ifdef HAVE_IPV6
  90     pa_assert(sa->sa_family == AF_INET || sa->sa_family == AF_INET6);
  91 #else
  92     pa_assert(sa->sa_family == AF_INET);
  93 #endif
  94
  95     header = htonl(((uint32_t) 1 << 29) |
  96 #ifdef HAVE_IPV6
  97                    (sa->sa_family == AF_INET6 ? (uint32_t) 1 << 28 : 0) |
  98 #endif
  99                    (goodbye ? (uint32_t) 1 << 26 : 0) |
 100                    (c->msg_id_hash));
 101
 102     iov[0].iov_base = &header;
 103     iov[0].iov_len = sizeof(header);
 104
 105     if (sa->sa_family == AF_INET) {
 106         iov[1].iov_base = (void*) &((struct sockaddr_in*) sa)->sin_addr;
 107         iov[1].iov_len = 4U;
 108 #ifdef HAVE_IPV6
 109     } else {
 110         iov[1].iov_base = (void*) &((struct sockaddr_in6*) sa)->sin6_addr;
 111         iov[1].iov_len = 16U;
 112 #endif
 113     }
 114
 115     iov[2].iov_base = (char*) MIME_TYPE;
 116     iov[2].iov_len = sizeof(MIME_TYPE);
 117
 118     iov[3].iov_base = c->sdp_data;
 119     iov[3].iov_len = strlen(c->sdp_data);
 120
 121     m.msg_name = NULL;
 122     m.msg_namelen = 0;
 123     m.msg_iov = iov;
 124     m.msg_iovlen = 4;
 125     m.msg_control = NULL;
 126     m.msg_controllen = 0;
 127     m.msg_flags = 0;
 128
 129     if ((k = sendmsg(c->fd, &m, MSG_DONTWAIT)) < 0)
 130         pa_log_warn("sendmsg() failed: %s\n", pa_cstrerror(errno));
 131
 132     return (int) k;
 133 }
 134
 135 pa_sap_context* pa_sap_context_init_recv(pa_sap_context *c, int fd) {
 136     pa_assert(c);
 137     pa_assert(fd >= 0);
 138
 139     c->fd = fd;
 140     c->sdp_data = NULL;
 141     return c;
 142 }
 143
 144 int pa_sap_recv(pa_sap_context *c, bool *goodbye) {
 145     struct msghdr m;
 146     struct iovec iov;
 147     int size;
 148     char *buf = NULL, *e;
 149     uint32_t header;
 150     unsigned six, ac, k;
 151     ssize_t r;
 152
 153     pa_assert(c);
 154     pa_assert(goodbye);
 155
 156     if (ioctl(c->fd, FIONREAD, &size) < 0) {
 157         pa_log_warn("FIONREAD failed: %s", pa_cstrerror(errno));
 158         goto fail;
 159     }
 160
 161     buf = pa_xnew(char, (unsigned) size+1);
 162     buf[size] = 0;
 163
 164     iov.iov_base = buf;
 165     iov.iov_len = (size_t) size;
 166
 167     m.msg_name = NULL;
 168     m.msg_namelen = 0;
 169     m.msg_iov = &iov;
 170     m.msg_iovlen = 1;
 171     m.msg_control = NULL;
 172     m.msg_controllen = 0;
 173     m.msg_flags = 0;
 174
 175     if ((r = recvmsg(c->fd, &m, 0)) != size) {
 176         pa_log_warn("recvmsg() failed: %s", r < 0 ? pa_cstrerror(errno) : "size mismatch");
 177         goto fail;
 178     }
 179
 180     if (size < 4) {
 181         pa_log_warn("SAP packet too short.");
 182         goto fail;
 183     }
 184
 185     memcpy(&header, buf, sizeof(uint32_t));
 186     header = ntohl(header);
 187
 188     if (header >> 29 != 1) {
 189         pa_log_warn("Unsupported SAP version.");
 190         goto fail;
 191     }
 192
 193     if ((header >> 25) & 1) {
 194         pa_log_warn("Encrypted SAP not supported.");
 195         goto fail;
 196     }
 197
 198     if ((header >> 24) & 1) {
 199         pa_log_warn("Compressed SAP not supported.");
 200         goto fail;
 201     }
 202
 203     six = (header >> 28) & 1U;
 204     ac = (header >> 16) & 0xFFU;
 205
 206     k = 4 + (six ? 16U : 4U) + ac*4U;
 207     if ((unsigned) size < k) {
 208         pa_log_warn("SAP packet too short (AD).");
 209         goto fail;
 210     }
 211
 212     e = buf + k;
 213     size -= (int) k;
 214
 215     if ((unsigned) size >= sizeof(MIME_TYPE) && pa_streq(e, MIME_TYPE)) {
 216         e += sizeof(MIME_TYPE);
 217         size -= (int) sizeof(MIME_TYPE);
 218     } else if ((unsigned) size < sizeof(PA_SDP_HEADER)-1 || strncmp(e, PA_SDP_HEADER, sizeof(PA_SDP_HEADER)-1)) {
 219         pa_log_warn("Invalid SDP header.");
 220         goto fail;
 221     }
 222
 223     if (c->sdp_data)
 224         pa_xfree(c->sdp_data);
 225
 226     c->sdp_data = pa_xstrndup(e, (unsigned) size);
 227     pa_xfree(buf);
 228
 229     *goodbye = !!((header >> 26) & 1);
 230
 231     return 0;
 232
 233 fail:
 234     pa_xfree(buf);
 235
 236     return -1;
 237 }