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
  42 #if defined(CONFIG_LINUX_MC_MREQ) || defined(CONFIG_LINUX_MC_MREQ_BIND)
  43 /*
  44  *  Older kernels support only struct mreq which matches interfaces by their
  45  *  addresses and thus fails on unnumbered devices. On newer 2.0 kernels
  46  *  we can use SO_BINDTODEVICE to circumvent this problem.
  47  */
  48
  49 #define MREQ_IFA struct in_addr
  50 #define MREQ_GRP struct ip_mreq
  51 static inline void fill_mreq_ifa(struct in_addr *m, struct iface *ifa, UNUSED ip_addr maddr)
  52 {
  53   set_inaddr(m, ifa->addr->ip);
  54 }
  55
  56 static inline void fill_mreq_grp(struct ip_mreq *m, struct iface *ifa, ip_addr maddr)
  57 {
  58   bzero(m, sizeof(*m));
  59 #ifdef CONFIG_LINUX_MC_MREQ_BIND
  60   m->imr_interface.s_addr = INADDR_ANY;
  61 #else
  62   set_inaddr(&m->imr_interface, ifa->addr->ip);
  63 #endif
  64   set_inaddr(&m->imr_multiaddr, maddr);
  65 }
  66 #endif
  67
  68
  69 #ifdef CONFIG_LINUX_MC_MREQN
  70 /*
  71  *  2.1 and newer kernels use struct mreqn which passes ifindex, so no
  72  *  problems with unnumbered devices.
  73  */
  74
  75 #ifndef HAVE_STRUCT_IP_MREQN
  76 /* Several versions of glibc don't define this structure, so we have to do it ourselves */
  77 struct ip_mreqn
  78 {
  79         struct in_addr  imr_multiaddr;          /* IP multicast address of group */
  80         struct in_addr  imr_address;            /* local IP address of interface */
  81         int             imr_ifindex;            /* Interface index */
  82 };
  83 #endif
  84
  85 #define MREQ_IFA struct ip_mreqn
  86 #define MREQ_GRP struct ip_mreqn
  87 #define fill_mreq_ifa fill_mreq
  88 #define fill_mreq_grp fill_mreq
  89
  90 static inline fill_mreq(struct ip_mreqn *m, struct iface *ifa, ip_addr maddr)
  91 {
  92   bzero(m, sizeof(*m));
  93   m->imr_ifindex = ifa->index;
  94   set_inaddr(&m->imr_address, ifa->addr->ip);
  95   set_inaddr(&m->imr_multiaddr, maddr);
  96 }
  97 #endif
  98
  99 static inline char *
 100 sysio_setup_multicast(sock *s)
 101 {
 102   MREQ_IFA m;
 103   int zero = 0;
 104
 105   if (setsockopt(s->fd, SOL_IP, IP_MULTICAST_LOOP, &zero, sizeof(zero)) < 0)
 106     return "IP_MULTICAST_LOOP";
 107
 108   if (setsockopt(s->fd, SOL_IP, IP_MULTICAST_TTL, &s->ttl, sizeof(s->ttl)) < 0)
 109     return "IP_MULTICAST_TTL";
 110
 111   /* This defines where should we send _outgoing_ multicasts */
 112   fill_mreq_ifa(&m, s->iface, IPA_NONE);
 113   if (setsockopt(s->fd, SOL_IP, IP_MULTICAST_IF, &m, sizeof(m)) < 0)
 114     return "IP_MULTICAST_IF";
 115
 116 #if defined(CONFIG_LINUX_MC_MREQ_BIND) || defined(CONFIG_LINUX_MC_MREQN)
 117   {
 118     struct ifreq ifr;
 119     strcpy(ifr.ifr_name, s->iface->name);
 120     if (setsockopt(s->fd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr)) < 0)
 121       return "SO_BINDTODEVICE";
 122   }
 123 #endif
 124
 125   return NULL;
 126 }
 127
 128 static inline char *
 129 sysio_join_group(sock *s, ip_addr maddr)
 130 {
 131   MREQ_GRP m;
 132
 133   /* And this one sets interface for _receiving_ multicasts from */
 134   fill_mreq_grp(&m, s->iface, maddr);
 135   if (setsockopt(s->fd, SOL_IP, IP_ADD_MEMBERSHIP, &m, sizeof(m)) < 0)
 136     return "IP_ADD_MEMBERSHIP";
 137
 138   return NULL;
 139 }
 140
 141 static inline char *
 142 sysio_leave_group(sock *s, ip_addr maddr)
 143 {
 144   MREQ_GRP m;
 145
 146   /* And this one sets interface for _receiving_ multicasts from */
 147   fill_mreq_grp(&m, s->iface, maddr);
 148   if (setsockopt(s->fd, SOL_IP, IP_DROP_MEMBERSHIP, &m, sizeof(m)) < 0)
 149     return "IP_DROP_MEMBERSHIP";
 150
 151   return NULL;
 152 }
 153
 154 #endif
 155
 156
 157 #include <linux/socket.h>
 158 #include <linux/tcp.h>
 159
 160 /* For the case that we have older kernel headers */
 161 /* Copied from Linux kernel file include/linux/tcp.h */
 162
 163 #ifndef TCP_MD5SIG
 164
 165 #define TCP_MD5SIG  14
 166 #define TCP_MD5SIG_MAXKEYLEN 80
 167
 168 struct tcp_md5sig {
 169   struct  sockaddr_storage tcpm_addr;             /* address associated */
 170   __u16   __tcpm_pad1;                            /* zero */
 171   __u16   tcpm_keylen;                            /* key length */
 172   __u32   __tcpm_pad2;                            /* zero */
 173   __u8    tcpm_key[TCP_MD5SIG_MAXKEYLEN];         /* key (binary) */
 174 };
 175
 176 #endif
 177
 178 static int
 179 sk_set_md5_auth_int(sock *s, sockaddr *sa, char *passwd)
 180 {
 181   struct tcp_md5sig md5;
 182
 183   memset(&md5, 0, sizeof(md5));
 184   memcpy(&md5.tcpm_addr, (struct sockaddr *) sa, sizeof(*sa));
 185
 186   if (passwd)
 187     {
 188       int len = strlen(passwd);
 189
 190       if (len > TCP_MD5SIG_MAXKEYLEN)
 191         {
 192           log(L_ERR "MD5 password too long");
 193           return -1;
 194         }
 195
 196       md5.tcpm_keylen = len;
 197       memcpy(&md5.tcpm_key, passwd, len);
 198     }
 199
 200   int rv = setsockopt(s->fd, IPPROTO_TCP, TCP_MD5SIG, &md5, sizeof(md5));
 201
 202   if (rv < 0)
 203     {
 204       if (errno == ENOPROTOOPT)
 205         log(L_ERR "Kernel does not support TCP MD5 signatures");
 206       else
 207         log(L_ERR "sk_set_md5_auth_int: setsockopt: %m");
 208     }
 209
 210   return rv;
 211 }