Commit 87a02489 authored by Alexander Zubkov's avatar Alexander Zubkov Committed by Ondrej Zajicek (work)
Browse files

IO: Support nonlocal bind in socket interface 

Add option to socket interface for nonlocal binding, i.e. binding to an
IP address that is not present on interfaces. This behaviour is enabled
when SKF_FREEBIND socket flag is set. For Linux systems, it is
implemented by IP_FREEBIND socket flag.

Minor changes done by commiter.
parent bcb25084

lib/socket.h

+1 −0
Original line number Diff line number Diff line
@@ -123,6 +123,7 @@ extern int sk_priority_control; /* Suggested priority for control traffic, shou 
#define SKF_TTL_RX	0x08	/* Report TTL / Hop Limit for RX packets */

#define SKF_BIND	0x10	/* Bind datagram socket to given source address */

#define SKF_HIGH_PORT	0x20	/* Choose port from high range if possible */

#define SKF_FREEBIND	0x40	/* Allow socket to bind to a nonlocal address */



#define SKF_THREAD	0x100	/* Socked used in thread, Do not add to main loop */

#define SKF_TRUNCATED	0x200	/* Received packet was truncated, set by IO layer */

sysdep/bsd/sysio.h

+6 −0
Original line number Diff line number Diff line
@@ -271,3 +271,9 @@ sk_set_priority(sock *s, int prio UNUSED) 
{

  ERR_MSG("Socket priority not supported");

}



static inline int

sk_set_freebind(sock *s)

{

  ERR_MSG("Freebind is not supported");

}

sysdep/linux/sysio.h

+19 −0
Original line number Diff line number Diff line
@@ -10,6 +10,10 @@ 
#define IPV6_MINHOPCOUNT 73

#endif



#ifndef IPV6_FREEBIND

#define IPV6_FREEBIND 78

#endif



#ifndef TCP_MD5SIG_EXT

#define TCP_MD5SIG_EXT 32

#endif
@@ -266,3 +270,18 @@ sk_set_priority(sock *s, int prio) 
  return 0;

}



static inline int

sk_set_freebind(sock *s)

{

  int y = 1;



  if (sk_is_ipv4(s))

    if (setsockopt(s->fd, SOL_IP, IP_FREEBIND, &y, sizeof(y)) < 0)

      ERR("IP_FREEBIND");



  if (sk_is_ipv6(s))

    if (setsockopt(s->fd, SOL_IPV6, IPV6_FREEBIND, &y, sizeof(y)) < 0)

      ERR("IPV6_FREEBIND");



  return 0;

}

sysdep/unix/io.c

+4 −0
Original line number Diff line number Diff line
@@ -1436,6 +1436,10 @@ sk_open(sock *s) 
	if (sk_set_high_port(s) < 0)

	  log(L_WARN "Socket error: %s%#m", s->err);



    if (s->flags & SKF_FREEBIND)

      if (sk_set_freebind(s) < 0)

        log(L_WARN "Socket error: %s%#m", s->err);



    sockaddr_fill(&sa, s->af, bind_addr, s->iface, bind_port);

    if (bind(fd, &sa.sa, SA_LEN(sa)) < 0)

      ERR2("bind");

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