lib/socket.h

   1 /*
   2  *      BIRD Socket Interface
   3  *
   4  *      (c) 1998--2004 Martin Mares <mj@ucw.cz>
   5  *
   6  *      Can be freely distributed and used under the terms of the GNU GPL.
   7  */
   8
   9 #ifndef _BIRD_SOCKET_H_
  10 #define _BIRD_SOCKET_H_
  11
  12 #include <errno.h>
  13
  14 #include "lib/resource.h"
  15 #ifdef HAVE_LIBSSH
  16 #define LIBSSH_LEGACY_0_4
  17 #include <libssh/libssh.h>
  18 #endif
  19
  20 #ifdef HAVE_LIBSSH
  21 struct ssh_sock {
  22     const char *username;               /* (Required) SSH user name */
  23     const char *server_hostkey_path;    /* (Optional) Filepath to the SSH public key of remote side, can be knownhost file */
  24     const char *client_privkey_path;    /* (Optional) Filepath to the SSH private key of BIRD */
  25     const char *subsystem;              /* (Optional) Name of SSH subsytem */
  26     ssh_session session;                /* Internal */
  27     ssh_channel channel;                /* Internal */
  28     int state;                          /* Internal */
  29 #define SK_SSH_CONNECT          0       /* Start state */
  30 #define SK_SSH_SERVER_KNOWN     1       /* Internal */
  31 #define SK_SSH_USERAUTH         2       /* Internal */
  32 #define SK_SSH_CHANNEL          3       /* Internal */
  33 #define SK_SSH_SESSION          4       /* Internal */
  34 #define SK_SSH_SUBSYSTEM        5       /* Internal */
  35 #define SK_SSH_ESTABLISHED      6       /* Final state */
  36 };
  37 #endif
  38
  39 typedef struct birdsock {
  40   resource r;
  41   pool *pool;                           /* Pool where incoming connections should be allocated (for SK_xxx_PASSIVE) */
  42   int type;                             /* Socket type */
  43   int subtype;                          /* Socket subtype */
  44   void *data;                           /* User data */
  45   ip_addr saddr, daddr;                 /* IPA_NONE = unspecified */
  46   const char *host;                     /* Alternative to daddr, NULL = unspecified */
  47   uint sport, dport;                    /* 0 = unspecified (for IP: protocol type) */
  48   int tos;                              /* TOS / traffic class, -1 = default */
  49   int priority;                         /* Local socket priority, -1 = default */
  50   int ttl;                              /* Time To Live, -1 = default */
  51   u32 flags;
  52   struct iface *iface;                  /* Interface; specify this for broad/multicast sockets */
  53   struct iface *vrf;                    /* Related VRF instance, NULL if global */
  54
  55   byte *rbuf, *rpos;                    /* NULL=allocate automatically */
  56   uint fast_rx;                         /* RX has higher priority in event loop */
  57   uint rbsize;
  58   int (*rx_hook)(struct birdsock *, uint size); /* NULL=receiving turned off, returns 1 to clear rx buffer */
  59
  60   byte *tbuf, *tpos;                    /* NULL=allocate automatically */
  61   byte *ttx;                            /* Internal */
  62   uint tbsize;
  63   void (*tx_hook)(struct birdsock *);
  64
  65   void (*err_hook)(struct birdsock *, int); /* errno or zero if EOF */
  66
  67   /* Information about received datagrams (UDP, RAW), valid in rx_hook */
  68   ip_addr faddr, laddr;                 /* src (From) and dst (Local) address of the datagram */
  69   uint fport;                           /* src port of the datagram */
  70   uint lifindex;                        /* local interface that received the datagram */
  71   /* laddr and lifindex are valid only if SKF_LADDR_RX flag is set to request it */
  72
  73   int af;                               /* System-dependend adress family (e.g. AF_INET) */
  74   int fd;                               /* System-dependent data */
  75   int index;                            /* Index in poll buffer */
  76   int rcv_ttl;                          /* TTL of last received datagram */
  77   node n;
  78   void *rbuf_alloc, *tbuf_alloc;
  79   char *password;                       /* Password for MD5 authentication */
  80   const char *err;                      /* Error message */
  81   struct ssh_sock *ssh;                 /* Used in SK_SSH */
  82 } sock;
  83
  84 sock *sock_new(pool *);                 /* Allocate new socket */
  85 #define sk_new(X) sock_new(X)           /* Wrapper to avoid name collision with OpenSSL */
  86
  87 int sk_open(sock *);                    /* Open socket */
  88 int sk_rx_ready(sock *s);
  89 int sk_send(sock *, uint len);          /* Send data, <0=err, >0=ok, 0=sleep */
  90 int sk_send_to(sock *, uint len, ip_addr to, uint port); /* sk_send to given destination */
  91 void sk_reallocate(sock *);             /* Free and allocate tbuf & rbuf */
  92 void sk_set_rbsize(sock *s, uint val);  /* Resize RX buffer */
  93 void sk_set_tbsize(sock *s, uint val);  /* Resize TX buffer, keeping content */
  94 void sk_set_tbuf(sock *s, void *tbuf);  /* Switch TX buffer, NULL-> return to internal */
  95 void sk_dump_all(void);
  96
  97 int sk_is_ipv4(sock *s);                /* True if socket is IPv4 */
  98 int sk_is_ipv6(sock *s);                /* True if socket is IPv6 */
  99
 100 static inline int sk_tx_buffer_empty(sock *sk)
 101 { return sk->tbuf == sk->tpos; }
 102
 103 int sk_setup_multicast(sock *s);        /* Prepare UDP or IP socket for multicasting */
 104 int sk_join_group(sock *s, ip_addr maddr);      /* Join multicast group on sk iface */
 105 int sk_leave_group(sock *s, ip_addr maddr);     /* Leave multicast group on sk iface */
 106 int sk_setup_broadcast(sock *s);
 107 int sk_set_ttl(sock *s, int ttl);       /* Set transmit TTL for given socket */
 108 int sk_set_min_ttl(sock *s, int ttl);   /* Set minimal accepted TTL for given socket */
 109 int sk_set_md5_auth(sock *s, ip_addr local, ip_addr remote, struct iface *ifa, char *passwd, int setkey);
 110 int sk_set_ipv6_checksum(sock *s, int offset);
 111 int sk_set_icmp6_filter(sock *s, int p1, int p2);
 112 void sk_log_error(sock *s, const char *p);
 113
 114 byte * sk_rx_buffer(sock *s, int *len); /* Temporary */
 115
 116 extern int sk_priority_control;         /* Suggested priority for control traffic, should be sysdep define */
 117
 118
 119 /* Socket flags */
 120
 121 #define SKF_V6ONLY      0x02    /* Use IPV6_V6ONLY socket option */
 122 #define SKF_LADDR_RX    0x04    /* Report local address for RX packets */
 123 #define SKF_TTL_RX      0x08    /* Report TTL / Hop Limit for RX packets */
 124 #define SKF_BIND        0x10    /* Bind datagram socket to given source address */
 125 #define SKF_HIGH_PORT   0x20    /* Choose port from high range if possible */
 126
 127 #define SKF_THREAD      0x100   /* Socked used in thread, Do not add to main loop */
 128 #define SKF_TRUNCATED   0x200   /* Received packet was truncated, set by IO layer */
 129 #define SKF_HDRINCL     0x400   /* Used internally */
 130 #define SKF_PKTINFO     0x800   /* Used internally */
 131
 132 /*
 133  *      Socket types                 SA SP DA DP IF  TTL SendTo (?=may, -=must not, *=must)
 134  */
 135
 136 #define SK_TCP_PASSIVE  0          /* ?  *  -  -  -  ?   -      */
 137 #define SK_TCP_ACTIVE   1          /* ?  ?  *  *  -  ?   -      */
 138 #define SK_TCP          2
 139 #define SK_UDP          3          /* ?  ?  ?  ?  ?  ?   ?      */
 140 #define SK_IP           5          /* ?  -  ?  *  ?  ?   ?      */
 141 #define SK_MAGIC        7          /* Internal use by sysdep code */
 142 #define SK_UNIX_PASSIVE 8
 143 #define SK_UNIX         9
 144 #define SK_SSH_ACTIVE   10         /* -  -  *  *  -  ?   -      DA = host */
 145 #define SK_SSH          11
 146
 147 /*
 148  *      Socket subtypes
 149  */
 150
 151 #define SK_IPV4         1
 152 #define SK_IPV6         2
 153
 154 /*
 155  * For TCP/IP sockets, Address family (IPv4 or IPv6) can be specified either
 156  * explicitly (SK_IPV4 or SK_IPV6) or implicitly (based on saddr, daddr). But
 157  * these specifications must be consistent.
 158  *
 159  * For SK_UDP or SK_IP sockets setting DA/DP allows to use sk_send(), otherwise
 160  * sk_send_to() must be used.
 161  *
 162  * For SK_IP sockets setting DP specifies protocol number, which is used for
 163  * both receiving and sending.
 164  *
 165  * For multicast on SK_UDP or SK_IP sockets set IF and TTL, call
 166  * sk_setup_multicast() to enable multicast on that socket, and then use
 167  * sk_join_group() and sk_leave_group() to manage a set of received multicast
 168  * groups.
 169  *
 170  * For datagram (SK_UDP, SK_IP) sockets, there are two ways to handle source
 171  * address. The socket could be bound to it using bind() syscall, but that also
 172  * forbids the reception of multicast packets, or the address could be set on
 173  * per-packet basis using platform dependent options (but these are not
 174  * available in some corner cases). The first way is used when SKF_BIND is
 175  * specified, the second way is used otherwise.
 176  */
 177
 178 #endif