1 /*****************************************************************************
2  * udp.c:
3  *****************************************************************************
4  * Copyright (C) 2004-2006 VLC authors and VideoLAN
5  * Copyright © 2006-2007 Rémi Denis-Courmont
6  *
7  * $Id: 2c1bc722de07a3f782a0bc98d6cf37ea78bff00c $
8  *
9  * Authors: Laurent Aimar <fenrir@videolan.org>
10  *          Rémi Denis-Courmont
11  *
12  * This program is free software; you can redistribute it and/or modify it
13  * under the terms of the GNU Lesser General Public License as published by
14  * the Free Software Foundation; either version 2.1 of the License, or
15  * (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20  * GNU Lesser General Public License for more details.
21  *
22  * You should have received a copy of the GNU Lesser General Public License
23  * along with this program; if not, write to the Free Software Foundation,
24  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
25  *****************************************************************************/
26 
27 /*****************************************************************************
28  * Preamble
29  *****************************************************************************/
30 #ifdef HAVE_CONFIG_H
31 # include "config.h"
32 #endif
33 
34 #include <vlc_common.h>
35 
36 #include <errno.h>
37 #include <assert.h>
38 
39 #include <vlc_network.h>
40 
41 #ifdef _WIN32
42 #   undef EAFNOSUPPORT
43 #   define EAFNOSUPPORT WSAEAFNOSUPPORT
44 #   include <iphlpapi.h>
45 #else
46 #   include <unistd.h>
47 #   ifdef HAVE_NET_IF_H
48 #       include <net/if.h>
49 #   endif
50 #endif
51 
52 #ifdef HAVE_LINUX_DCCP_H
53 # include <linux/dccp.h>
54 # ifndef SOCK_DCCP /* provisional API */
55 #  define SOCK_DCCP 6
56 # endif
57 #endif
58 
59 #ifndef SOL_IP
60 # define SOL_IP IPPROTO_IP
61 #endif
62 #ifndef SOL_IPV6
63 # define SOL_IPV6 IPPROTO_IPV6
64 #endif
65 #ifndef IPPROTO_IPV6
66 # define IPPROTO_IPV6 41 /* IANA */
67 #endif
68 #ifndef SOL_DCCP
69 # define SOL_DCCP IPPROTO_DCCP
70 #endif
71 #ifndef IPPROTO_DCCP
72 # define IPPROTO_DCCP 33 /* IANA */
73 #endif
74 #ifndef SOL_UDPLITE
75 # define SOL_UDPLITE IPPROTO_UDPLITE
76 #endif
77 #ifndef IPPROTO_UDPLITE
78 # define IPPROTO_UDPLITE 136 /* IANA */
79 #endif
80 
81 #if defined (HAVE_NETINET_UDPLITE_H)
82 # include <netinet/udplite.h>
83 #elif defined (__linux__)
84 /* still missing from glibc 2.6 */
85 # define UDPLITE_SEND_CSCOV     10
86 # define UDPLITE_RECV_CSCOV     11
87 #endif
88 
89 extern int net_Socket( vlc_object_t *p_this, int i_family, int i_socktype,
90                        int i_protocol );
91 
92 /* */
net_SetupDgramSocket(vlc_object_t * p_obj,int fd,const struct addrinfo * ptr)93 static int net_SetupDgramSocket (vlc_object_t *p_obj, int fd,
94                                  const struct addrinfo *ptr)
95 {
96 #if defined (SO_REUSEPORT) && !defined (__linux__)
97     setsockopt (fd, SOL_SOCKET, SO_REUSEPORT, &(int){ 1 }, sizeof (int));
98 #endif
99 
100 #if defined (_WIN32)
101 
102     /* Check windows version so we know if we need to increase receive buffers
103      * for Windows 7 and earlier
104 
105      * SetSocketMediaStreamingMode is present in win 8 and later, so we set
106      * receive buffer if that isn't present
107      */
108 #if (_WIN32_WINNT < _WIN32_WINNT_WIN8)
109     HINSTANCE h_Network = LoadLibrary(TEXT("Windows.Networking.dll"));
110     if( (h_Network == NULL) ||
111         (GetProcAddress( h_Network, "SetSocketMediaStreamingMode" ) == NULL ) )
112     {
113         setsockopt (fd, SOL_SOCKET, SO_RCVBUF,
114                          (void *)&(int){ 0x80000 }, sizeof (int));
115     }
116     if( h_Network )
117         FreeLibrary( h_Network );
118 #endif
119 
120     if (net_SockAddrIsMulticast (ptr->ai_addr, ptr->ai_addrlen)
121      && (sizeof (struct sockaddr_storage) >= ptr->ai_addrlen))
122     {
123         // This works for IPv4 too - don't worry!
124         struct sockaddr_in6 dumb =
125         {
126             .sin6_family = ptr->ai_addr->sa_family,
127             .sin6_port =  ((struct sockaddr_in *)(ptr->ai_addr))->sin_port
128         };
129 
130         bind (fd, (struct sockaddr *)&dumb, ptr->ai_addrlen);
131     }
132     else
133 #endif
134     if (bind (fd, ptr->ai_addr, ptr->ai_addrlen))
135     {
136         msg_Err( p_obj, "socket bind error: %s", vlc_strerror_c(net_errno) );
137         net_Close (fd);
138         return -1;
139     }
140     return fd;
141 }
142 
143 /* */
net_ListenSingle(vlc_object_t * obj,const char * host,int port,int protocol)144 static int net_ListenSingle (vlc_object_t *obj, const char *host, int port,
145                              int protocol)
146 {
147     struct addrinfo hints = {
148         .ai_socktype = SOCK_DGRAM,
149         .ai_protocol = protocol,
150         .ai_flags = AI_PASSIVE | AI_NUMERICSERV | AI_IDN,
151     }, *res;
152 
153     if (host && !*host)
154         host = NULL;
155 
156     msg_Dbg (obj, "net: opening %s datagram port %d",
157              host ? host : "any", port);
158 
159     int val = vlc_getaddrinfo (host, port, &hints, &res);
160     if (val)
161     {
162         msg_Err (obj, "Cannot resolve %s port %d : %s", host, port,
163                  gai_strerror (val));
164         return -1;
165     }
166 
167     val = -1;
168 
169     for (const struct addrinfo *ptr = res; ptr != NULL; ptr = ptr->ai_next)
170     {
171         int fd = net_Socket (obj, ptr->ai_family, ptr->ai_socktype,
172                              ptr->ai_protocol);
173         if (fd == -1)
174         {
175             msg_Dbg (obj, "socket error: %s", vlc_strerror_c(net_errno));
176             continue;
177         }
178 
179 #ifdef IPV6_V6ONLY
180         /* Try dual-mode IPv6 if available. */
181         if (ptr->ai_family == AF_INET6)
182             setsockopt (fd, SOL_IPV6, IPV6_V6ONLY, &(int){ 0 }, sizeof (int));
183 #endif
184         fd = net_SetupDgramSocket( obj, fd, ptr );
185         if( fd == -1 )
186             continue;
187 
188         if (net_SockAddrIsMulticast (ptr->ai_addr, ptr->ai_addrlen)
189          && net_Subscribe (obj, fd, ptr->ai_addr, ptr->ai_addrlen))
190         {
191             net_Close (fd);
192             continue;
193         }
194 
195         val = fd;
196         break;
197     }
198 
199     freeaddrinfo (res);
200     return val;
201 }
202 
203 
net_SetMcastHopLimit(vlc_object_t * p_this,int fd,int family,int hlim)204 static int net_SetMcastHopLimit( vlc_object_t *p_this,
205                                  int fd, int family, int hlim )
206 {
207     int proto, cmd;
208 
209     /* There is some confusion in the world whether IP_MULTICAST_TTL
210      * takes a byte or an int as an argument.
211      * BSD seems to indicate byte so we are going with that and use
212      * int as a fallback to be safe */
213     switch( family )
214     {
215 #ifdef IP_MULTICAST_TTL
216         case AF_INET:
217             proto = SOL_IP;
218             cmd = IP_MULTICAST_TTL;
219             break;
220 #endif
221 
222 #ifdef IPV6_MULTICAST_HOPS
223         case AF_INET6:
224             proto = SOL_IPV6;
225             cmd = IPV6_MULTICAST_HOPS;
226             break;
227 #endif
228 
229         default:
230             errno = EAFNOSUPPORT;
231             msg_Warn( p_this, "%s", vlc_strerror_c(EAFNOSUPPORT) );
232             return VLC_EGENERIC;
233     }
234 
235     if( setsockopt( fd, proto, cmd, &hlim, sizeof( hlim ) ) < 0 )
236     {
237         /* BSD compatibility */
238         unsigned char buf;
239 
240         msg_Dbg( p_this, "cannot set hop limit (%d): %s", hlim,
241                  vlc_strerror_c(net_errno) );
242         buf = (unsigned char)(( hlim > 255 ) ? 255 : hlim);
243         if( setsockopt( fd, proto, cmd, &buf, sizeof( buf ) ) )
244         {
245             msg_Err( p_this, "cannot set hop limit (%d): %s", hlim,
246                      vlc_strerror_c(net_errno) );
247             return VLC_EGENERIC;
248         }
249     }
250 
251     return VLC_SUCCESS;
252 }
253 
254 
net_SetMcastOut(vlc_object_t * p_this,int fd,int family,const char * iface)255 static int net_SetMcastOut (vlc_object_t *p_this, int fd, int family,
256                             const char *iface)
257 {
258     int scope = if_nametoindex (iface);
259     if (scope == 0)
260     {
261         msg_Err (p_this, "invalid multicast interface: %s", iface);
262         return -1;
263     }
264 
265     switch (family)
266     {
267 #ifdef IPV6_MULTICAST_IF
268         case AF_INET6:
269             if (setsockopt (fd, SOL_IPV6, IPV6_MULTICAST_IF,
270                             &scope, sizeof (scope)) == 0)
271                 return 0;
272             break;
273 #endif
274 
275 #ifdef __linux__
276         case AF_INET:
277         {
278             struct ip_mreqn req = { .imr_ifindex = scope };
279             if (setsockopt (fd, SOL_IP, IP_MULTICAST_IF,
280                             &req, sizeof (req)) == 0)
281                 return 0;
282             break;
283         }
284 #endif
285         default:
286             errno = EAFNOSUPPORT;
287     }
288     msg_Err (p_this, "cannot force multicast interface %s: %s", iface,
289              vlc_strerror_c(errno));
290     return -1;
291 }
292 
293 
var_GetIfIndex(vlc_object_t * obj)294 static unsigned var_GetIfIndex (vlc_object_t *obj)
295 {
296     char *ifname = var_InheritString (obj, "miface");
297     if (ifname == NULL)
298         return 0;
299 
300     unsigned ifindex = if_nametoindex (ifname);
301     if (ifindex == 0)
302         msg_Err (obj, "invalid multicast interface: %s", ifname);
303     free (ifname);
304     return ifindex;
305 }
306 
307 
308 /**
309  * IP-agnostic multicast join,
310  * with fallback to old APIs, and fallback from SSM to ASM.
311  */
312 static int
net_SourceSubscribe(vlc_object_t * obj,int fd,const struct sockaddr * src,socklen_t srclen,const struct sockaddr * grp,socklen_t grplen)313 net_SourceSubscribe (vlc_object_t *obj, int fd,
314                      const struct sockaddr *src, socklen_t srclen,
315                      const struct sockaddr *grp, socklen_t grplen)
316 {
317 /* MCAST_JOIN_SOURCE_GROUP was introduced to OS X in v10.7, but it doesn't work,
318  * so ignore it to use the same code path as on 10.5 or 10.6 */
319 #if defined (MCAST_JOIN_SOURCE_GROUP) && !defined (__APPLE__) && !defined (__FreeBSD__)
320     /* Family-agnostic Source-Specific Multicast join */
321     int level;
322     struct group_source_req gsr;
323 
324     memset (&gsr, 0, sizeof (gsr));
325     gsr.gsr_interface = var_GetIfIndex (obj);
326 
327     switch (grp->sa_family)
328     {
329 #ifdef AF_INET6
330         case AF_INET6:
331         {
332             const struct sockaddr_in6 *g6 = (const struct sockaddr_in6 *)grp;
333 
334             level = SOL_IPV6;
335             assert (grplen >= sizeof (struct sockaddr_in6));
336             if (g6->sin6_scope_id != 0)
337                 gsr.gsr_interface = g6->sin6_scope_id;
338             break;
339         }
340 #endif
341         case AF_INET:
342             level = SOL_IP;
343             break;
344         default:
345             errno = EAFNOSUPPORT;
346             return -1;
347     }
348 
349     assert (grplen <= sizeof (gsr.gsr_group));
350     memcpy (&gsr.gsr_source, src, srclen);
351     assert (srclen <= sizeof (gsr.gsr_source));
352     memcpy (&gsr.gsr_group,  grp, grplen);
353     if (setsockopt (fd, level, MCAST_JOIN_SOURCE_GROUP,
354                     &gsr, sizeof (gsr)) == 0)
355         return 0;
356 
357 #else
358     if (src->sa_family != grp->sa_family)
359     {
360         errno = EAFNOSUPPORT;
361         return -1;
362     }
363 
364     switch (grp->sa_family)
365     {
366 # ifdef IP_ADD_SOURCE_MEMBERSHIP
367         /* IPv4-specific API */
368         case AF_INET:
369         {
370             struct ip_mreq_source imr;
371 
372             memset (&imr, 0, sizeof (imr));
373             assert (grplen >= sizeof (struct sockaddr_in));
374             imr.imr_multiaddr = ((const struct sockaddr_in *)grp)->sin_addr;
375             assert (srclen >= sizeof (struct sockaddr_in));
376             imr.imr_sourceaddr = ((const struct sockaddr_in *)src)->sin_addr;
377             if (setsockopt (fd, SOL_IP, IP_ADD_SOURCE_MEMBERSHIP,
378                             &imr, sizeof (imr)) == 0)
379                 return 0;
380             break;
381         }
382 # endif
383         default:
384             errno = EAFNOSUPPORT;
385     }
386 
387 #endif
388     msg_Err (obj, "cannot join source multicast group: %s",
389              vlc_strerror_c(net_errno));
390     msg_Warn (obj, "trying ASM instead of SSM...");
391     return net_Subscribe (obj, fd, grp, grplen);
392 }
393 
394 
net_Subscribe(vlc_object_t * obj,int fd,const struct sockaddr * grp,socklen_t grplen)395 int net_Subscribe (vlc_object_t *obj, int fd,
396                    const struct sockaddr *grp, socklen_t grplen)
397 {
398 /* MCAST_JOIN_GROUP was introduced to OS X in v10.7, but it doesn't work,
399  * so ignore it to use the same code as on 10.5 or 10.6 */
400 #if defined (MCAST_JOIN_GROUP) && !defined (__APPLE__)
401     /* Family-agnostic Any-Source Multicast join */
402     int level;
403     struct group_req gr;
404 
405     memset (&gr, 0, sizeof (gr));
406     gr.gr_interface = var_GetIfIndex (obj);
407 
408     switch (grp->sa_family)
409     {
410 #ifdef AF_INET6
411         case AF_INET6:
412         {
413             const struct sockaddr_in6 *g6 = (const struct sockaddr_in6 *)grp;
414 
415             level = SOL_IPV6;
416             assert (grplen >= sizeof (struct sockaddr_in6));
417             if (g6->sin6_scope_id != 0)
418                 gr.gr_interface = g6->sin6_scope_id;
419             break;
420         }
421 #endif
422         case AF_INET:
423             level = SOL_IP;
424             break;
425         default:
426             errno = EAFNOSUPPORT;
427             return -1;
428     }
429 
430     assert (grplen <= sizeof (gr.gr_group));
431     memcpy (&gr.gr_group, grp, grplen);
432     if (setsockopt (fd, level, MCAST_JOIN_GROUP, &gr, sizeof (gr)) == 0)
433         return 0;
434 
435 #else
436     switch (grp->sa_family)
437     {
438 # ifdef IPV6_JOIN_GROUP
439         case AF_INET6:
440         {
441             struct ipv6_mreq ipv6mr;
442             const struct sockaddr_in6 *g6 = (const struct sockaddr_in6 *)grp;
443 
444             memset (&ipv6mr, 0, sizeof (ipv6mr));
445             assert (grplen >= sizeof (struct sockaddr_in6));
446             ipv6mr.ipv6mr_multiaddr = g6->sin6_addr;
447             ipv6mr.ipv6mr_interface = g6->sin6_scope_id;
448             if (!setsockopt (fd, SOL_IPV6, IPV6_JOIN_GROUP,
449                              &ipv6mr, sizeof (ipv6mr)))
450                 return 0;
451             break;
452         }
453 # endif
454 # ifdef IP_ADD_MEMBERSHIP
455         case AF_INET:
456         {
457             struct ip_mreq imr;
458 
459             memset (&imr, 0, sizeof (imr));
460             assert (grplen >= sizeof (struct sockaddr_in));
461             imr.imr_multiaddr = ((const struct sockaddr_in *)grp)->sin_addr;
462             if (setsockopt (fd, SOL_IP, IP_ADD_MEMBERSHIP,
463                             &imr, sizeof (imr)) == 0)
464                 return 0;
465             break;
466         }
467 # endif
468         default:
469             errno = EAFNOSUPPORT;
470     }
471 
472 #endif
473     msg_Err (obj, "cannot join multicast group: %s",
474              vlc_strerror_c(net_errno));
475     return -1;
476 }
477 
478 
net_SetDSCP(int fd,uint8_t dscp)479 static int net_SetDSCP( int fd, uint8_t dscp )
480 {
481     struct sockaddr_storage addr;
482     if( getsockname( fd, (struct sockaddr *)&addr, &(socklen_t){ sizeof (addr) }) )
483         return -1;
484 
485     int level, cmd;
486 
487     switch( addr.ss_family )
488     {
489 #ifdef IPV6_TCLASS
490         case AF_INET6:
491             level = SOL_IPV6;
492             cmd = IPV6_TCLASS;
493             break;
494 #endif
495 
496         case AF_INET:
497             level = SOL_IP;
498             cmd = IP_TOS;
499             break;
500 
501         default:
502 #ifdef ENOPROTOOPT
503             errno = ENOPROTOOPT;
504 #endif
505             return -1;
506     }
507 
508     return setsockopt( fd, level, cmd, &(int){ dscp }, sizeof (int));
509 }
510 
511 #undef net_ConnectDgram
512 /*****************************************************************************
513  * net_ConnectDgram:
514  *****************************************************************************
515  * Open a datagram socket to send data to a defined destination, with an
516  * optional hop limit.
517  *****************************************************************************/
net_ConnectDgram(vlc_object_t * p_this,const char * psz_host,int i_port,int i_hlim,int proto)518 int net_ConnectDgram( vlc_object_t *p_this, const char *psz_host, int i_port,
519                       int i_hlim, int proto )
520 {
521     struct addrinfo hints = {
522         .ai_socktype = SOCK_DGRAM,
523         .ai_protocol = proto,
524         .ai_flags = AI_NUMERICSERV | AI_IDN,
525     }, *res;
526     int       i_handle = -1;
527     bool      b_unreach = false;
528 
529     if( i_hlim < 0 )
530         i_hlim = var_InheritInteger( p_this, "ttl" );
531 
532     msg_Dbg( p_this, "net: connecting to [%s]:%d", psz_host, i_port );
533 
534     int val = vlc_getaddrinfo (psz_host, i_port, &hints, &res);
535     if (val)
536     {
537         msg_Err (p_this, "cannot resolve [%s]:%d : %s", psz_host, i_port,
538                  gai_strerror (val));
539         return -1;
540     }
541 
542     for (struct addrinfo *ptr = res; ptr != NULL; ptr = ptr->ai_next)
543     {
544         char *str;
545         int fd = net_Socket (p_this, ptr->ai_family, ptr->ai_socktype,
546                              ptr->ai_protocol);
547         if (fd == -1)
548             continue;
549 
550         /* Allow broadcast sending */
551         setsockopt (fd, SOL_SOCKET, SO_BROADCAST, &(int){ 1 }, sizeof (int));
552 
553         if( i_hlim >= 0 )
554             net_SetMcastHopLimit( p_this, fd, ptr->ai_family, i_hlim );
555 
556         str = var_InheritString (p_this, "miface");
557         if (str != NULL)
558         {
559             net_SetMcastOut (p_this, fd, ptr->ai_family, str);
560             free (str);
561         }
562 
563         net_SetDSCP (fd, var_InheritInteger (p_this, "dscp"));
564 
565         if( connect( fd, ptr->ai_addr, ptr->ai_addrlen ) == 0 )
566         {
567             /* success */
568             i_handle = fd;
569             break;
570         }
571 
572 #if defined( _WIN32 )
573         if( WSAGetLastError () == WSAENETUNREACH )
574 #else
575         if( errno == ENETUNREACH )
576 #endif
577             b_unreach = true;
578         else
579             msg_Warn( p_this, "%s port %d : %s", psz_host, i_port,
580                       vlc_strerror_c(errno) );
581         net_Close( fd );
582     }
583 
584     freeaddrinfo( res );
585 
586     if( i_handle == -1 )
587     {
588         if( b_unreach )
589             msg_Err( p_this, "Host %s port %d is unreachable", psz_host,
590                      i_port );
591         return -1;
592     }
593 
594     return i_handle;
595 }
596 
597 #undef net_OpenDgram
598 /*****************************************************************************
599  * net_OpenDgram:
600  *****************************************************************************
601  * OpenDgram a datagram socket and return a handle
602  *****************************************************************************/
net_OpenDgram(vlc_object_t * obj,const char * psz_bind,int i_bind,const char * psz_server,int i_server,int protocol)603 int net_OpenDgram( vlc_object_t *obj, const char *psz_bind, int i_bind,
604                    const char *psz_server, int i_server, int protocol )
605 {
606     if ((psz_server == NULL) || (psz_server[0] == '\0'))
607         return net_ListenSingle (obj, psz_bind, i_bind, protocol);
608 
609     msg_Dbg (obj, "net: connecting to [%s]:%d from [%s]:%d",
610              psz_server, i_server, psz_bind, i_bind);
611 
612     struct addrinfo hints = {
613         .ai_socktype = SOCK_DGRAM,
614         .ai_protocol = protocol,
615         .ai_flags = AI_NUMERICSERV | AI_IDN,
616     }, *loc, *rem;
617 
618     int val = vlc_getaddrinfo (psz_server, i_server, &hints, &rem);
619     if (val)
620     {
621         msg_Err (obj, "cannot resolve %s port %d : %s", psz_server, i_server,
622                  gai_strerror (val));
623         return -1;
624     }
625 
626     hints.ai_flags |= AI_PASSIVE;
627     val = vlc_getaddrinfo (psz_bind, i_bind, &hints, &loc);
628     if (val)
629     {
630         msg_Err (obj, "cannot resolve %s port %d : %s", psz_bind, i_bind,
631                  gai_strerror (val));
632         freeaddrinfo (rem);
633         return -1;
634     }
635 
636     val = -1;
637     for (struct addrinfo *ptr = loc; ptr != NULL; ptr = ptr->ai_next)
638     {
639         int fd = net_Socket (obj, ptr->ai_family, ptr->ai_socktype,
640                              ptr->ai_protocol);
641         if (fd == -1)
642             continue; // usually, address family not supported
643 
644         fd = net_SetupDgramSocket( obj, fd, ptr );
645         if( fd == -1 )
646             continue;
647 
648         for (struct addrinfo *ptr2 = rem; ptr2 != NULL; ptr2 = ptr2->ai_next)
649         {
650             if ((ptr2->ai_family != ptr->ai_family)
651              || (ptr2->ai_socktype != ptr->ai_socktype)
652              || (ptr2->ai_protocol != ptr->ai_protocol))
653                 continue;
654 
655             if (net_SockAddrIsMulticast (ptr->ai_addr, ptr->ai_addrlen)
656               ? net_SourceSubscribe (obj, fd,
657                                      ptr2->ai_addr, ptr2->ai_addrlen,
658                                      ptr->ai_addr, ptr->ai_addrlen)
659               : connect (fd, ptr2->ai_addr, ptr2->ai_addrlen))
660             {
661                 msg_Err (obj, "cannot connect to %s port %d: %s",
662                          psz_server, i_server, vlc_strerror_c(net_errno));
663                 continue;
664             }
665             val = fd;
666             break;
667         }
668 
669         if (val != -1)
670             break;
671 
672         net_Close (fd);
673     }
674 
675     freeaddrinfo (rem);
676     freeaddrinfo (loc);
677     return val;
678 }
679 
680 
681 /**
682  * net_SetCSCov:
683  * Sets the send and receive checksum coverage of a socket:
684  * @param fd socket
685  * @param sendcov payload coverage of sent packets (bytes), -1 for full
686  * @param recvcov minimum payload coverage of received packets, -1 for full
687  */
net_SetCSCov(int fd,int sendcov,int recvcov)688 int net_SetCSCov (int fd, int sendcov, int recvcov)
689 {
690     int type;
691 
692     if (getsockopt (fd, SOL_SOCKET, SO_TYPE,
693                     &type, &(socklen_t){ sizeof (type) }))
694         return VLC_EGENERIC;
695 
696     switch (type)
697     {
698 #ifdef UDPLITE_RECV_CSCOV
699         case SOCK_DGRAM: /* UDP-Lite */
700             if (sendcov == -1)
701                 sendcov = 0;
702             else
703                 sendcov += 8; /* partial */
704             if (setsockopt (fd, SOL_UDPLITE, UDPLITE_SEND_CSCOV, &sendcov,
705                             sizeof (sendcov)))
706                 return VLC_EGENERIC;
707 
708             if (recvcov == -1)
709                 recvcov = 0;
710             else
711                 recvcov += 8;
712             if (setsockopt (fd, SOL_UDPLITE, UDPLITE_RECV_CSCOV,
713                             &recvcov, sizeof (recvcov)))
714                 return VLC_EGENERIC;
715 
716             return VLC_SUCCESS;
717 #endif
718 #ifdef DCCP_SOCKOPT_SEND_CSCOV
719         case SOCK_DCCP: /* DCCP and its ill-named socket type */
720             if ((sendcov == -1) || (sendcov > 56))
721                 sendcov = 0;
722             else
723                 sendcov = (sendcov + 3) / 4;
724             if (setsockopt (fd, SOL_DCCP, DCCP_SOCKOPT_SEND_CSCOV,
725                             &sendcov, sizeof (sendcov)))
726                 return VLC_EGENERIC;
727 
728             if ((recvcov == -1) || (recvcov > 56))
729                 recvcov = 0;
730             else
731                 recvcov = (recvcov + 3) / 4;
732             if (setsockopt (fd, SOL_DCCP, DCCP_SOCKOPT_RECV_CSCOV,
733                             &recvcov, sizeof (recvcov)))
734                 return VLC_EGENERIC;
735 
736             return VLC_SUCCESS;
737 #endif
738     }
739 #if !defined( UDPLITE_RECV_CSCOV ) && !defined( DCCP_SOCKOPT_SEND_CSCOV )
740     VLC_UNUSED(sendcov);
741     VLC_UNUSED(recvcov);
742 #endif
743 
744     return VLC_EGENERIC;
745 }
746