sysdep/linux/sysio.h

   1 /*
   2  *      BIRD Internet Routing Daemon -- Linux Multicasting and Network Includes
   3  *
   4  *      (c) 1998--2000 Martin Mares <mj@ucw.cz>
   5  *
   6  *      Can be freely distributed and used under the terms of the GNU GPL.
   7  */
   8
   9 #ifdef IPV6
  10
  11 #ifndef IPV6_UNICAST_HOPS
  12 /* Needed on glibc 2.0 systems */
  13 #include <linux/in6.h>
  14 #define CONFIG_IPV6_GLIBC_20
  15 #endif
  16
  17 static inline void
  18 set_inaddr(struct in6_addr *ia, ip_addr a)
  19 {
  20   ipa_hton(a);
  21   memcpy(ia, &a, sizeof(a));
  22 }
  23
  24 #else
  25
  26 #include <net/if.h>
  27
  28 static inline void
  29 set_inaddr(struct in_addr *ia, ip_addr a)
  30 {
  31   ipa_hton(a);
  32   memcpy(&ia->s_addr, &a, sizeof(a));
  33 }
  34
  35 /*
  36  *  Multicasting in Linux systems is a real mess. Not only different kernels
  37  *  have different interfaces, but also different libc's export it in different
  38  *  ways. Horrible.
  39  */
  40
  41 static inline char *sysio_mcast_setup(sock *s)
  42 {
  43   int zero = 0;
  44
  45   if (ipa_nonzero(s->daddr))
  46     {
  47       if (
  48 #ifdef IP_DEFAULT_MULTICAST_TTL
  49           s->ttl != IP_DEFAULT_MULTICAST_TTL &&
  50 #endif
  51           setsockopt(s->fd, SOL_IP, IP_MULTICAST_TTL, &s->ttl, sizeof(s->ttl)) < 0)
  52         return "IP_MULTICAST_TTL";
  53       if (
  54 #ifdef IP_DEFAULT_MULTICAST_LOOP
  55           IP_DEFAULT_MULTICAST_LOOP &&
  56 #endif
  57           setsockopt(s->fd, SOL_IP, IP_MULTICAST_LOOP, &zero, sizeof(zero)) < 0)
  58         return "IP_MULTICAST_LOOP";
  59     }
  60   return NULL;
  61 }
  62
  63 #ifdef CONFIG_LINUX_MC_MREQN
  64 /*
  65  *  2.1 and newer kernels use struct mreqn which passes ifindex, so no
  66  *  problems with unnumbered devices.
  67  */
  68
  69 #ifndef HAVE_STRUCT_IP_MREQN
  70 /* Several versions of glibc don't define this structure, so we have to do it ourselves */
  71 struct ip_mreqn
  72 {
  73         struct in_addr  imr_multiaddr;          /* IP multicast address of group */
  74         struct in_addr  imr_address;            /* local IP address of interface */
  75         int             imr_ifindex;            /* Interface index */
  76 };
  77 #endif
  78
  79 static inline char *sysio_mcast_join(sock *s)
  80 {
  81   struct ip_mreqn mreq;
  82   char *err;
  83   struct ifreq ifr;
  84
  85   if (err = sysio_mcast_setup(s))
  86     return err;
  87   strcpy(ifr.ifr_name, s->iface->name);
  88   if (setsockopt(s->fd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr)) < 0)
  89     return "SO_BINDTODEVICE";
  90   mreq.imr_ifindex = s->iface->index;
  91   set_inaddr(&mreq.imr_address, s->iface->addr->ip);
  92   set_inaddr(&mreq.imr_multiaddr, s->daddr);
  93   /* This defines where should we send _outgoing_ multicasts */
  94   if (ipa_nonzero(s->daddr) && setsockopt(s->fd, SOL_IP, IP_MULTICAST_IF, &mreq, sizeof(mreq)) < 0)
  95     return "IP_MULTICAST_IF";
  96   /* And this one sets interface for _receiving_ multicasts from */
  97   if (ipa_nonzero(s->saddr) && setsockopt(s->fd, SOL_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0)
  98     return "IP_ADD_MEMBERSHIP";
  99   return NULL;
 100 }
 101 #endif
 102
 103 #if defined(CONFIG_LINUX_MC_MREQ) || defined(CONFIG_LINUX_MC_MREQ_BIND)
 104 /*
 105  *  Older kernels support only struct mreq which matches interfaces by their
 106  *  addresses and thus fails on unnumbered devices. On newer 2.0 kernels
 107  *  we can use SO_BINDTODEVICE to circumvent this problem.
 108  */
 109
 110 static inline char *sysio_mcast_join(sock *s)
 111 {
 112   struct in_addr mreq;
 113   struct ip_mreq mreq_add;
 114   char *err;
 115
 116   if (err = sysio_mcast_setup(s))
 117     return err;
 118   set_inaddr(&mreq, s->iface->addr->ip);
 119 #ifdef CONFIG_LINUX_MC_MREQ_BIND
 120   {
 121     struct ifreq ifr;
 122     strcpy(ifr.ifr_name, s->iface->name);
 123     if (setsockopt(s->fd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr)) < 0)
 124       return "SO_BINDTODEVICE";
 125     mreq_add.imr_interface.s_addr = INADDR_ANY;
 126   }
 127 #else
 128   mreq_add.imr_interface = mreq;
 129 #endif
 130   set_inaddr(&mreq_add.imr_multiaddr, s->daddr);
 131   /* This defines where should we send _outgoing_ multicasts */
 132   if (ipa_nonzero(s->daddr) && setsockopt(s->fd, SOL_IP, IP_MULTICAST_IF, &mreq, sizeof(mreq)) < 0)
 133     return "IP_MULTICAST_IF";
 134   /* And this one sets interface for _receiving_ multicasts from */
 135   if (ipa_nonzero(s->saddr) && setsockopt(s->fd, SOL_IP, IP_ADD_MEMBERSHIP, &mreq_add, sizeof(mreq_add)) < 0)
 136     return "IP_ADD_MEMBERSHIP";
 137   return NULL;
 138 }
 139 #endif
 140
 141 #endif
 142
 143 #include <linux/socket.h>
 144 #include <linux/tcp.h>
 145
 146 /* For the case that we have older kernel headers */
 147 /* Copied from Linux kernel file include/linux/tcp.h */
 148
 149 #ifndef TCP_MD5SIG
 150
 151 #define TCP_MD5SIG  14
 152 #define TCP_MD5SIG_MAXKEYLEN 80
 153
 154 struct tcp_md5sig {
 155   struct  sockaddr_storage tcpm_addr;             /* address associated */
 156   __u16   __tcpm_pad1;                            /* zero */
 157   __u16   tcpm_keylen;                            /* key length */
 158   __u32   __tcpm_pad2;                            /* zero */
 159   __u8    tcpm_key[TCP_MD5SIG_MAXKEYLEN];         /* key (binary) */
 160 };
 161
 162 #endif
 163
 164 static int
 165 sk_set_md5_auth_int(sock *s, sockaddr *sa, char *passwd)
 166 {
 167   struct tcp_md5sig md5;
 168
 169   memset(&md5, 0, sizeof(md5));
 170   memcpy(&md5.tcpm_addr, (struct sockaddr *) sa, sizeof(*sa));
 171
 172   if (passwd)
 173     {
 174       int len = strlen(passwd);
 175
 176       if (len > TCP_MD5SIG_MAXKEYLEN)
 177         {
 178           log(L_ERR "MD5 password too long");
 179           return -1;
 180         }
 181
 182       md5.tcpm_keylen = len;
 183       memcpy(&md5.tcpm_key, passwd, len);
 184     }
 185
 186   int rv = setsockopt(s->fd, IPPROTO_TCP, TCP_MD5SIG, &md5, sizeof(md5));
 187
 188   if (rv < 0)
 189     {
 190       if (errno == ENOPROTOOPT)
 191         log(L_ERR "Kernel does not support TCP MD5 signatures");
 192       else
 193         log(L_ERR "sk_set_md5_auth_int: setsockopt: %m");
 194     }
 195
 196   return rv;
 197 }