bird/sysdep/bsd/sysio.h
Alexander Zubkov 87a02489f3 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.
2022-01-08 19:02:31 +01:00

279 lines
5.9 KiB
C

/*
* BIRD Internet Routing Daemon -- BSD Multicasting and Network Includes
*
* (c) 2004 Ondrej Filip <feela@network.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#include <net/if_dl.h>
#include <netinet/in_systm.h> // Workaround for some BSDs
#include <netinet/ip.h>
#include <sys/param.h>
#ifdef __FreeBSD__
/* Should be defined in sysdep/cf/bsd.h, but it is flavor-specific */
#define CONFIG_DONTROUTE_UNICAST
#endif
#ifdef __NetBSD__
#ifndef IP_RECVTTL
#define IP_RECVTTL 23
#endif
#ifndef IP_MINTTL
#define IP_MINTTL 24
#endif
#endif
#ifdef __DragonFly__
#define TCP_MD5SIG TCP_SIGNATURE_ENABLE
#endif
#undef SA_LEN
#define SA_LEN(x) (x).sa.sa_len
/*
* BSD IPv4 multicast syscalls
*/
#define INIT_MREQ4(maddr,ifa) \
{ .imr_multiaddr = ipa_to_in4(maddr), .imr_interface = ip4_to_in4(ifa->sysdep) }
static inline int
sk_setup_multicast4(sock *s)
{
struct in_addr ifa = ip4_to_in4(s->iface->sysdep);
u8 ttl = s->ttl;
u8 n = 0;
/* This defines where should we send _outgoing_ multicasts */
if (setsockopt(s->fd, IPPROTO_IP, IP_MULTICAST_IF, &ifa, sizeof(ifa)) < 0)
ERR("IP_MULTICAST_IF");
if (setsockopt(s->fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
ERR("IP_MULTICAST_TTL");
if (setsockopt(s->fd, IPPROTO_IP, IP_MULTICAST_LOOP, &n, sizeof(n)) < 0)
ERR("IP_MULTICAST_LOOP");
return 0;
}
static inline int
sk_join_group4(sock *s, ip_addr maddr)
{
struct ip_mreq mr = INIT_MREQ4(maddr, s->iface);
if (setsockopt(s->fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mr, sizeof(mr)) < 0)
ERR("IP_ADD_MEMBERSHIP");
return 0;
}
static inline int
sk_leave_group4(sock *s, ip_addr maddr)
{
struct ip_mreq mr = INIT_MREQ4(maddr, s->iface);
if (setsockopt(s->fd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mr, sizeof(mr)) < 0)
ERR("IP_ADD_MEMBERSHIP");
return 0;
}
/*
* BSD IPv4 packet control messages
*/
/* It uses IP_RECVDSTADDR / IP_RECVIF socket options instead of IP_PKTINFO */
#define CMSG4_SPACE_PKTINFO (CMSG_SPACE(sizeof(struct in_addr)) + \
CMSG_SPACE(sizeof(struct sockaddr_dl)))
#define CMSG4_SPACE_TTL CMSG_SPACE(sizeof(char))
static inline int
sk_request_cmsg4_pktinfo(sock *s)
{
int y = 1;
if (setsockopt(s->fd, IPPROTO_IP, IP_RECVDSTADDR, &y, sizeof(y)) < 0)
ERR("IP_RECVDSTADDR");
if (setsockopt(s->fd, IPPROTO_IP, IP_RECVIF, &y, sizeof(y)) < 0)
ERR("IP_RECVIF");
return 0;
}
static inline int
sk_request_cmsg4_ttl(sock *s)
{
int y = 1;
if (setsockopt(s->fd, IPPROTO_IP, IP_RECVTTL, &y, sizeof(y)) < 0)
ERR("IP_RECVTTL");
return 0;
}
static inline void
sk_process_cmsg4_pktinfo(sock *s, struct cmsghdr *cm)
{
if (cm->cmsg_type == IP_RECVDSTADDR)
s->laddr = ipa_from_in4(* (struct in_addr *) CMSG_DATA(cm));
if (cm->cmsg_type == IP_RECVIF)
s->lifindex = ((struct sockaddr_dl *) CMSG_DATA(cm))->sdl_index;
}
static inline void
sk_process_cmsg4_ttl(sock *s, struct cmsghdr *cm)
{
if (cm->cmsg_type == IP_RECVTTL)
s->rcv_ttl = * (byte *) CMSG_DATA(cm);
}
#ifdef IP_SENDSRCADDR
static inline void
sk_prepare_cmsgs4(sock *s, struct msghdr *msg, void *cbuf, size_t cbuflen)
{
/* Unfortunately, IP_SENDSRCADDR does not work for raw IP sockets on BSD kernels */
struct cmsghdr *cm;
struct in_addr *sa;
int controllen = 0;
msg->msg_control = cbuf;
msg->msg_controllen = cbuflen;
cm = CMSG_FIRSTHDR(msg);
cm->cmsg_level = IPPROTO_IP;
cm->cmsg_type = IP_SENDSRCADDR;
cm->cmsg_len = CMSG_LEN(sizeof(*sa));
controllen += CMSG_SPACE(sizeof(*sa));
sa = (struct in_addr *) CMSG_DATA(cm);
*sa = ipa_to_in4(s->saddr);
msg->msg_controllen = controllen;
}
#else
static inline void
sk_prepare_cmsgs4(sock *s UNUSED, struct msghdr *msg UNUSED, void *cbuf UNUSED, size_t cbuflen UNUSED) { }
#endif
static void UNUSED
sk_prepare_ip_header(sock *s, void *hdr, int dlen)
{
struct ip *ip = hdr;
bzero(ip, 20);
ip->ip_v = 4;
ip->ip_hl = 5;
ip->ip_tos = (s->tos < 0) ? 0 : s->tos;
ip->ip_len = 20 + dlen;
ip->ip_ttl = (s->ttl < 0) ? 64 : s->ttl;
ip->ip_p = s->dport;
ip->ip_src = ipa_to_in4(s->saddr);
ip->ip_dst = ipa_to_in4(s->daddr);
#if (defined __OpenBSD__) || (defined __DragonFly__) || (defined __FreeBSD__ && (__FreeBSD_version >= 1100030))
/* Different BSDs have different expectations of ip_len endianity */
ip->ip_len = htons(ip->ip_len);
#endif
}
/*
* Miscellaneous BSD socket syscalls
*/
#ifndef TCP_KEYLEN_MAX
#define TCP_KEYLEN_MAX 80
#endif
#ifndef TCP_SIG_SPI
#define TCP_SIG_SPI 0x1000
#endif
#if defined(__FreeBSD__)
#define USE_MD5SIG_SETKEY
#include "sysdep/bsd/setkey.h"
#endif
int
sk_set_md5_auth(sock *s, ip_addr local UNUSED, ip_addr remote UNUSED, int pxlen UNUSED, struct iface *ifa UNUSED, const char *passwd, int setkey UNUSED)
{
#ifdef USE_MD5SIG_SETKEY
if (setkey)
if (sk_set_md5_in_sasp_db(s, local, remote, pxlen, ifa, passwd) < 0)
return -1;
#endif
int enable = (passwd && *passwd) ? TCP_SIG_SPI : 0;
if (setsockopt(s->fd, IPPROTO_TCP, TCP_MD5SIG, &enable, sizeof(enable)) < 0)
{
if (errno == ENOPROTOOPT)
ERR_MSG("Kernel does not support TCP MD5 signatures");
else
ERR("TCP_MD5SIG");
}
return 0;
}
static inline int
sk_set_min_ttl4(sock *s, int ttl)
{
if (setsockopt(s->fd, IPPROTO_IP, IP_MINTTL, &ttl, sizeof(ttl)) < 0)
{
if (errno == ENOPROTOOPT)
ERR_MSG("Kernel does not support IPv4 TTL security");
else
ERR("IP_MINTTL");
}
return 0;
}
static inline int
sk_set_min_ttl6(sock *s, int ttl UNUSED)
{
ERR_MSG("Kernel does not support IPv6 TTL security");
}
static inline int
sk_disable_mtu_disc4(sock *s UNUSED)
{
/* TODO: Set IP_DONTFRAG to 0 ? */
return 0;
}
static inline int
sk_disable_mtu_disc6(sock *s UNUSED)
{
/* TODO: Set IPV6_DONTFRAG to 0 ? */
return 0;
}
int sk_priority_control = -1;
static inline int
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");
}