src/stream_output/sdp.c

   1 /*****************************************************************************
   2  * sdp.c : SDP creation helpers
   3  *****************************************************************************
   4  * Copyright © 2007 Rémi Denis-Courmont
   5  * $Id$
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU Lesser General Public License as published by
   9  * the Free Software Foundation; either version 2.1 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15  * GNU Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public License
  18  * along with this program; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  20  *****************************************************************************/
  21
  22 #ifdef HAVE_CONFIG_H
  23 # include "config.h"
  24 #endif
  25
  26 #include <vlc_common.h>
  27
  28 #include <stddef.h>
  29 #include <string.h>
  30 #include <stdarg.h>
  31 #include <stdio.h>
  32 #include <assert.h>
  33 #include <vlc_network.h>
  34 #include <vlc_charset.h>
  35
  36 #include "stream_output.h"
  37
  38 #define MAXSDPADDRESS 47
  39
  40 static
  41 char *AddressToSDP (const struct sockaddr *addr, socklen_t addrlen, char *buf)
  42 {
  43     if (addrlen < offsetof (struct sockaddr, sa_family)
  44                  + sizeof (addr->sa_family))
  45         return NULL;
  46
  47     strcpy (buf, "IN IP* ");
  48
  49     if (vlc_getnameinfo (addr, addrlen, buf + 7, MAXSDPADDRESS - 7, NULL,
  50                          NI_NUMERICHOST))
  51         return NULL;
  52
  53     switch (addr->sa_family)
  54     {
  55         case AF_INET:
  56         {
  57             if (net_SockAddrIsMulticast (addr, addrlen))
  58                 strcat (buf, "/255"); // obsolete in RFC4566, dummy value
  59             buf[5] = '4';
  60             break;
  61         }
  62
  63 #ifdef AF_INET6
  64         case AF_INET6:
  65         {
  66             char *ptr = strchr (buf, '%');
  67             if (ptr != NULL)
  68                 *ptr = '\0'; // remove scope ID
  69             buf[5] = '6';
  70             break;
  71         }
  72 #endif
  73
  74         default:
  75             return NULL;
  76     }
  77
  78     return buf;
  79 }
  80
  81
  82 static bool IsSDPString (const char *str)
  83 {
  84     if (strchr (str, '\r') != NULL)
  85         return false;
  86     if (strchr (str, '\n') != NULL)
  87         return false;
  88     if (!IsUTF8 (str))
  89         return false;
  90     return true;
  91 }
  92
  93
  94 static
  95 char *sdp_Start (const char *name, const char *description, const char *url,
  96                  const char *email, const char *phone,
  97                  const struct sockaddr *src, size_t srclen,
  98                  const struct sockaddr *addr, size_t addrlen)
  99 {
 100     uint64_t now = NTPtime64 ();
 101     char *sdp;
 102     char connection[MAXSDPADDRESS], hostname[256],
 103          sfilter[MAXSDPADDRESS + sizeof ("\r\na=source-filter: incl * ")];
 104     const char *preurl = "\r\nu=", *premail = "\r\ne=", *prephone = "\r\np=";
 105
 106     gethostname (hostname, sizeof (hostname));
 107
 108     if (name == NULL)
 109         name = "Unnamed";
 110     if (description == NULL)
 111         description = "N/A";
 112     if (url == NULL)
 113         preurl = url = "";
 114     if (email == NULL)
 115         premail = email = "";
 116     if (phone == NULL)
 117         prephone = phone = "";
 118
 119     if (!IsSDPString (name) || !IsSDPString (description)
 120      || !IsSDPString (url) || !IsSDPString (email) || !IsSDPString (phone)
 121      || (AddressToSDP (addr, addrlen, connection) == NULL))
 122         return NULL;
 123
 124     strcpy (sfilter, "");
 125     if (srclen > 0)
 126     {
 127         char machine[MAXSDPADDRESS];
 128
 129         if (AddressToSDP (src, srclen, machine) != NULL)
 130             sprintf (sfilter, "\r\na=source-filter: incl IN IP%c * %s",
 131                      machine[5], machine + 7);
 132     }
 133
 134     if (asprintf (&sdp, "v=0"
 135                     "\r\no=- %"PRIu64" %"PRIu64" IN IP%c %s"
 136                     "\r\ns=%s"
 137                     "\r\ni=%s"
 138                     "%s%s" // optional URL
 139                     "%s%s" // optional email
 140                     "%s%s" // optional phone number
 141                     "\r\nc=%s"
 142                         // bandwidth not specified
 143                     "\r\nt=0 0" // one dummy time span
 144                         // no repeating
 145                         // no time zone adjustment (silly idea anyway)
 146                         // no encryption key (deprecated)
 147                     "\r\na=tool:"PACKAGE_STRING
 148                     "\r\na=recvonly"
 149                     "\r\na=type:broadcast"
 150                     "\r\na=charset:UTF-8"
 151                     "%s" // optional source filter
 152                     "\r\n",
 153                /* o= */ now, now, connection[5], hostname,
 154                /* s= */ name,
 155                /* i= */ description,
 156                /* u= */ preurl, url,
 157                /* e= */ premail, email,
 158                /* p= */ prephone, phone,
 159                /* c= */ connection,
 160     /* source-filter */ sfilter) == -1)
 161         return NULL;
 162     return sdp;
 163 }
 164
 165
 166 static char *
 167 vsdp_AddAttribute (char **sdp, const char *name, const char *fmt, va_list ap)
 168 {
 169     size_t oldlen = strlen (*sdp);
 170     size_t addlen = sizeof ("a=\r\n") + strlen (name);
 171
 172     if (fmt != NULL)
 173     {
 174         va_list aq;
 175
 176         va_copy (aq, ap);
 177         addlen += 1 + vsnprintf (NULL, 0, fmt, aq);
 178         va_end (aq);
 179     }
 180
 181     char *ret = realloc (*sdp, oldlen + addlen);
 182     if (ret == NULL)
 183         return NULL;
 184
 185     oldlen += sprintf (ret + oldlen, "a=%s", name);
 186     if (fmt != NULL)
 187     {
 188         ret[oldlen++] = ':';
 189         oldlen += vsprintf (ret + oldlen, fmt, ap);
 190     }
 191
 192     strcpy (ret + oldlen, "\r\n");
 193     return *sdp = ret;
 194 }
 195
 196
 197 char *sdp_AddAttribute (char **sdp, const char *name, const char *fmt, ...)
 198 {
 199     char *ret;
 200     va_list ap;
 201
 202     va_start (ap, fmt);
 203     ret = vsdp_AddAttribute (sdp, name, fmt, ap);
 204     va_end (ap);
 205
 206     return ret;
 207 }
 208
 209
 210 char *sdp_AddMedia (char **sdp,
 211                     const char *type, const char *protocol, int dport,
 212                     unsigned pt, bool bw_indep, unsigned bw,
 213                     const char *ptname, unsigned clock, unsigned chans,
 214                     const char *fmtp)
 215 {
 216     char *newsdp, *ptr;
 217     size_t inlen = strlen (*sdp), outlen = inlen;
 218
 219     /* Some default values */
 220     if (type == NULL)
 221         type = "video";
 222     if (protocol == NULL)
 223         protocol = "RTP/AVP";
 224     assert (pt < 128u);
 225
 226     outlen += snprintf (NULL, 0,
 227                         "m=%s %u %s %d\r\n"
 228                         "b=TIAS:%u\r\n"
 229                         "b=RR:0\r\n",
 230                         type, dport, protocol, pt, bw);
 231
 232     newsdp = realloc (*sdp, outlen + 1);
 233     if (newsdp == NULL)
 234         return NULL;
 235
 236     *sdp = newsdp;
 237     ptr = newsdp + inlen;
 238
 239     ptr += sprintf (ptr, "m=%s %u %s %u\r\n",
 240                          type, dport, protocol, pt);
 241     if (bw > 0)
 242         ptr += sprintf (ptr, "b=%s:%u\r\n", bw_indep ? "TIAS" : "AS", bw);
 243     ptr += sprintf (ptr, "b=RR:0\r\n");
 244
 245     /* RTP payload type map */
 246     if (ptname != NULL)
 247     {
 248         if ((strcmp (type, "audio") == 0) && (chans != 1))
 249             sdp_AddAttribute (sdp, "rtpmap", "%u %s/%u/%u", pt, ptname, clock,
 250                               chans);
 251         else
 252             sdp_AddAttribute (sdp, "rtpmap", "%u %s/%u", pt, ptname, clock);
 253     }
 254     /* Format parameters */
 255     if (fmtp != NULL)
 256         sdp_AddAttribute (sdp, "fmtp", "%u %s", pt, fmtp);
 257
 258     return newsdp;
 259 }
 260
 261
 262 char *vlc_sdp_Start (vlc_object_t *obj, const char *cfgpref,
 263                      const struct sockaddr *src, size_t srclen,
 264                      const struct sockaddr *addr, size_t addrlen)
 265 {
 266     size_t cfglen = strlen (cfgpref);
 267     if (cfglen > 100)
 268         return NULL;
 269
 270     char varname[cfglen + sizeof ("description")], *subvar = varname + cfglen;
 271     strcpy (varname, cfgpref);
 272
 273     strcpy (subvar, "name");
 274     char *name = var_GetNonEmptyString (obj, varname);
 275     strcpy (subvar, "description");
 276     char *description = var_GetNonEmptyString (obj, varname);
 277     strcpy (subvar, "url");
 278     char *url = var_GetNonEmptyString (obj, varname);
 279     strcpy (subvar, "email");
 280     char *email = var_GetNonEmptyString (obj, varname);
 281     strcpy (subvar, "phone");
 282     char *phone = var_GetNonEmptyString (obj, varname);
 283
 284     char *sdp = sdp_Start (name, description, url, email, phone,
 285                            src, srclen, addr, addrlen);
 286     free (name);
 287     free (description);
 288     free (url);
 289     free (email);
 290     free (phone);
 291
 292     if (sdp == NULL)
 293         return NULL;
 294
 295     /* Totally non-standard */
 296     strcpy (subvar, "group");
 297     char *group = var_GetNonEmptyString (obj, varname);
 298     if (group != NULL)
 299     {
 300         sdp_AddAttribute (&sdp, "x-plgroup", "%s", group);
 301         free (group);
 302     }
 303
 304     return sdp;
 305 }