udp.c

VLC Player Source Code

/*****************************************************************************
 * udp.c:
 *****************************************************************************
 * Copyright (C) 2004-2006 the VideoLAN team
 * Copyright © 2006-2007 Rémi Denis-Courmont
 *
 * $Id$
 *
 * Authors: Laurent Aimar <[e-mail]>
 *          Rémi Denis-Courmont <rem # videolan.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
 *****************************************************************************/

/*****************************************************************************
 * Preamble
 *****************************************************************************/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <vlc_common.h>

#include <errno.h>

#ifdef HAVE_SYS_TIME_H
#    include <sys/time.h>
#endif

#include <vlc_network.h>

#ifdef WIN32
#   if defined(UNDER_CE)
#       undef IP_MULTICAST_TTL
#       define IP_MULTICAST_TTL 3
#       undef IP_ADD_MEMBERSHIP
#       define IP_ADD_MEMBERSHIP 5
#   endif
#   define EAFNOSUPPORT WSAEAFNOSUPPORT
#   define if_nametoindex( str ) atoi( str )
#else
#   include <unistd.h>
#   ifdef HAVE_NET_IF_H
#       include <net/if.h>
#   endif
#endif

#ifdef HAVE_LINUX_DCCP_H
# include <linux/dccp.h>
# ifndef SOCK_DCCP /* provisional API */
#  define SOCK_DCCP 6
# endif
#endif

#ifndef SOL_IP
# define SOL_IP IPPROTO_IP
#endif
#ifndef SOL_IPV6
# define SOL_IPV6 IPPROTO_IPV6
#endif
#ifndef IPPROTO_IPV6
# define IPPROTO_IPV6 41 /* IANA */
#endif
#ifndef SOL_DCCP
# define SOL_DCCP IPPROTO_DCCP
#endif
#ifndef IPPROTO_DCCP
# define IPPROTO_DCCP 33 /* IANA */
#endif
#ifndef SOL_UDPLITE
# define SOL_UDPLITE IPPROTO_UDPLITE
#endif
#ifndef IPPROTO_UDPLITE
# define IPPROTO_UDPLITE 136 /* IANA */
#endif

#if defined (HAVE_NETINET_UDPLITE_H)
# include <netinet/udplite.h>
#elif defined (__linux__)
/* still missing from glibc 2.6 */
# define UDPLITE_SEND_CSCOV     10
# define UDPLITE_RECV_CSCOV     11
#endif

extern int net_Socket( vlc_object_t *p_this, int i_family, int i_socktype,
                       int i_protocol );

/* */
static int net_SetupDgramSocket( vlc_object_t *p_obj, int fd, const struct addrinfo *ptr )
{
#ifdef SO_REUSEPORT
    setsockopt (fd, SOL_SOCKET, SO_REUSEPORT, &(int){ 1 }, sizeof (int));
#endif

#ifdef SO_RCVBUF
    /* Increase the receive buffer size to 1/2MB (8Mb/s during 1/2s)
     * to avoid packet loss caused in case of scheduling hiccups */
    setsockopt (fd, SOL_SOCKET, SO_RCVBUF,
                (void *)&(int){ 0x80000 }, sizeof (int));
    setsockopt (fd, SOL_SOCKET, SO_SNDBUF,
                (void *)&(int){ 0x80000 }, sizeof (int));
#endif

#if defined (WIN32) || defined (UNDER_CE)
    if (net_SockAddrIsMulticast (ptr->ai_addr, ptr->ai_addrlen)
     && (sizeof (struct sockaddr_storage) >= ptr->ai_addrlen))
    {
        // This works for IPv4 too - don't worry!
        struct sockaddr_in6 dumb =
        {
            .sin6_family = ptr->ai_addr->sa_family,
            .sin6_port =  ((struct sockaddr_in *)(ptr->ai_addr))->sin_port
        };

        bind (fd, (struct sockaddr *)&dumb, ptr->ai_addrlen);
    }
    else
#endif
    if (bind (fd, ptr->ai_addr, ptr->ai_addrlen))
    {
        msg_Err( p_obj, "socket bind error (%m)" );
        net_Close (fd);
        return -1;
    }
    return fd;
}

/* */
static int net_ListenSingle (vlc_object_t *obj, const char *host, int port,
                             int family, int protocol)
{
    struct addrinfo hints, *res;

    memset (&hints, 0, sizeof( hints ));
    hints.ai_family = family;
    hints.ai_socktype = SOCK_DGRAM;
    hints.ai_flags = AI_PASSIVE;

    if (host && !*host)
        host = NULL;

    msg_Dbg (obj, "net: opening %s datagram port %d", host ?: "any", port);

    int val = vlc_getaddrinfo (obj, host, port, &hints, &res);
    if (val)
    {
        msg_Err (obj, "Cannot resolve %s port %d : %s", host, port,
                 vlc_gai_strerror (val));
        return -1;
    }

    val = -1;

    for (const struct addrinfo *ptr = res; ptr != NULL; ptr = ptr->ai_next)
    {
        int fd = net_Socket (obj, ptr->ai_family, ptr->ai_socktype,
                             protocol ?: ptr->ai_protocol);
        if (fd == -1)
        {
            msg_Dbg (obj, "socket error: %m");
            continue;
        }

        if (ptr->ai_next != NULL)
        {
#ifdef IPV6_V6ONLY
            if ((ptr->ai_family != AF_INET6)
             || setsockopt (fd, SOL_IPV6, IPV6_V6ONLY, &(int){ 0 },
                            sizeof (int)))
#endif
            {
                msg_Err (obj, "Multiple network protocols present");
                msg_Err (obj, "Please select network protocol manually");
            }
        }

        fd = net_SetupDgramSocket( obj, fd, ptr );
        if( fd == -1 )
            continue;

        if (net_SockAddrIsMulticast (ptr->ai_addr, ptr->ai_addrlen)
         && net_Subscribe (obj, fd, ptr->ai_addr, ptr->ai_addrlen))
        {
            net_Close (fd);
            continue;
        }

        val = fd;
        break;
    }

    vlc_freeaddrinfo (res);
    return val;
}


static int net_SetMcastHopLimit( vlc_object_t *p_this,
                                 int fd, int family, int hlim )
{
    int proto, cmd;

    /* There is some confusion in the world whether IP_MULTICAST_TTL
     * takes a byte or an int as an argument.
     * BSD seems to indicate byte so we are going with that and use
     * int as a fallback to be safe */
    switch( family )
    {
#ifdef IP_MULTICAST_TTL
        case AF_INET:
            proto = SOL_IP;
            cmd = IP_MULTICAST_TTL;
            break;
#endif

#ifdef IPV6_MULTICAST_HOPS
        case AF_INET6:
            proto = SOL_IPV6;
            cmd = IPV6_MULTICAST_HOPS;
            break;
#endif

        default:
            errno = EAFNOSUPPORT;
            msg_Warn( p_this, "%m" );
            return VLC_EGENERIC;
    }

    if( setsockopt( fd, proto, cmd, &hlim, sizeof( hlim ) ) < 0 )
    {
        /* BSD compatibility */
        unsigned char buf;

        buf = (unsigned char)(( hlim > 255 ) ? 255 : hlim);
        if( setsockopt( fd, proto, cmd, &buf, sizeof( buf ) ) )
            return VLC_EGENERIC;
    }

    return VLC_SUCCESS;
}


static int net_SetMcastOutIface (int fd, int family, int scope)
{
    switch (family)
    {
#ifdef IPV6_MULTICAST_IF
        case AF_INET6:
            return setsockopt (fd, SOL_IPV6, IPV6_MULTICAST_IF,
                               &scope, sizeof (scope));
#endif

#ifdef __linux__
        case AF_INET:
        {
            struct ip_mreqn req = { .imr_ifindex = scope };

            return setsockopt (fd, SOL_IP, IP_MULTICAST_IF, &req,
                               sizeof (req));
        }
#endif
    }

    errno = EAFNOSUPPORT;
    return -1;
}


static inline int net_SetMcastOutIPv4 (int fd, struct in_addr ipv4)
{
#ifdef IP_MULTICAST_IF
    return setsockopt( fd, SOL_IP, IP_MULTICAST_IF, &ipv4, sizeof (ipv4));
#else
    errno = EAFNOSUPPORT;
    return -1;
#endif
}


static int net_SetMcastOut (vlc_object_t *p_this, int fd, int family,
                            const char *iface, const char *addr)
{
    if (iface != NULL)
    {
        int scope = if_nametoindex (iface);
        if (scope == 0)
        {
            msg_Err (p_this, "invalid multicast interface: %s", iface);
            return -1;
        }

        if (net_SetMcastOutIface (fd, family, scope) == 0)
            return 0;

        msg_Err (p_this, "%s: %m", iface);
    }

    if (addr != NULL)
    {
        if (family == AF_INET)
        {
            struct in_addr ipv4;
            if (inet_pton (AF_INET, addr, &ipv4) <= 0)
            {
                msg_Err (p_this, "invalid IPv4 address for multicast: %s",
                         addr);
                return -1;
            }

            if (net_SetMcastOutIPv4 (fd, ipv4) == 0)
                return 0;

            msg_Err (p_this, "%s: %m", addr);
        }
    }

    return -1;
}


/**
 * Old-style any-source multicast join.
 * In use on Windows XP/2003 and older.
 */
static int
net_IPv4Join (vlc_object_t *obj, int fd,
              const struct sockaddr_in *src, const struct sockaddr_in *grp)
{
#ifdef IP_ADD_MEMBERSHIP
    union
    {
        struct ip_mreq gr4;
# ifdef IP_ADD_SOURCE_MEMBERSHIP
        struct ip_mreq_source gsr4;
# endif
    } opt;
    int cmd;
    struct in_addr id = { .s_addr = INADDR_ANY };
    socklen_t optlen;

    /* Multicast interface IPv4 address */
    char *iface = var_CreateGetNonEmptyString (obj, "miface-addr");
    if ((iface != NULL)
     && (inet_pton (AF_INET, iface, &id) <= 0))
    {
        msg_Err (obj, "invalid multicast interface address %s", iface);
        free (iface);
        goto error;
    }
    free (iface);

    memset (&opt, 0, sizeof (opt));
    if (src != NULL)
    {
# ifdef IP_ADD_SOURCE_MEMBERSHIP
        cmd = IP_ADD_SOURCE_MEMBERSHIP;
        opt.gsr4.imr_multiaddr = grp->sin_addr;
        opt.gsr4.imr_sourceaddr = src->sin_addr;
        opt.gsr4.imr_interface = id;
        optlen = sizeof (opt.gsr4);
# else
        errno = ENOSYS;
        goto error;
# endif
    }
    else
    {
        cmd = IP_ADD_MEMBERSHIP;
        opt.gr4.imr_multiaddr = grp->sin_addr;
        opt.gr4.imr_interface = id;
        optlen = sizeof (opt.gr4);
    }

    msg_Dbg (obj, "IP_ADD_%sMEMBERSHIP multicast request",
             (src != NULL) ? "SOURCE_" : "");

    if (setsockopt (fd, SOL_IP, cmd, &opt, optlen) == 0)
        return 0;

error:
#endif

    msg_Err (obj, "cannot join IPv4 multicast group (%m)");
    return -1;
}


static int
net_IPv6Join (vlc_object_t *obj, int fd, const struct sockaddr_in6 *src)
{
#ifdef IPV6_JOIN_GROUP
    struct ipv6_mreq gr6;
    memset (&gr6, 0, sizeof (gr6));
    gr6.ipv6mr_interface = src->sin6_scope_id;
    memcpy (&gr6.ipv6mr_multiaddr, &src->sin6_addr, 16);

    msg_Dbg (obj, "IPV6_JOIN_GROUP multicast request");

    if (!setsockopt (fd, SOL_IPV6, IPV6_JOIN_GROUP, &gr6, sizeof (gr6)))
        return 0;
#else
    errno = ENOSYS;
#endif

    msg_Err (obj, "cannot join IPv6 any-source multicast group (%m)");
    return -1;
}


#if defined (WIN32) && !defined (MCAST_JOIN_SOURCE_GROUP)
/*
 * I hate manual definitions: Error-prone. Portability hell.
 * Developers shall use UP-TO-DATE compilers. Full point.
 * If you remove the warning, you remove the whole ifndef.
 */
#  warning Your C headers are out-of-date. Please update.

#  define MCAST_JOIN_GROUP 41
struct group_req
{
    ULONG gr_interface;
    struct sockaddr_storage gr_group;
};

#  define MCAST_JOIN_SOURCE_GROUP 45 /* from <ws2ipdef.h> */
struct group_source_req
{
    uint32_t gsr_interface;
    struct sockaddr_storage gsr_group;
    struct sockaddr_storage gsr_source;
};