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/* setsockopt functions
* Copyright (C) 1999 Kunihiro Ishiguro
*
* This file is part of GNU Zebra.
*
* GNU Zebra is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2, or (at your option) any
* later version.
*
* GNU Zebra is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU Zebra; see the file COPYING. If not, write to the Free
* Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
* 02111-1307, USA.
*/
#include <zebra.h>
#include "log.h"
#include "sockopt.h"
int
setsockopt_so_recvbuf (int sock, int size)
{
int ret;
if ( (ret = setsockopt (sock, SOL_SOCKET, SO_RCVBUF, (char *)
&size, sizeof (int))) < 0)
zlog_err ("fd %d: can't setsockopt SO_RCVBUF to %d: %s",
sock,size,safe_strerror(errno));
return ret;
}
static void *
getsockopt_cmsg_data (struct msghdr *msgh, int level, int type)
{
struct cmsghdr *cmsg;
void *ptr = NULL;
for (cmsg = ZCMSG_FIRSTHDR(msgh);
cmsg != NULL;
cmsg = CMSG_NXTHDR(msgh, cmsg))
if (cmsg->cmsg_level == level && cmsg->cmsg_type)
return (ptr = CMSG_DATA(cmsg));
return NULL;
}
#ifdef HAVE_IPV6
/* Set IPv6 packet info to the socket. */
int
setsockopt_ipv6_pktinfo (int sock, int val)
{
int ret;
#ifdef IPV6_RECVPKTINFO /*2292bis-01*/
ret = setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val, sizeof(val));
if (ret < 0)
zlog_warn ("can't setsockopt IPV6_RECVPKTINFO : %s", safe_strerror (errno));
#else /*RFC2292*/
ret = setsockopt(sock, IPPROTO_IPV6, IPV6_PKTINFO, &val, sizeof(val));
if (ret < 0)
zlog_warn ("can't setsockopt IPV6_PKTINFO : %s", safe_strerror (errno));
#endif /* INIA_IPV6 */
return ret;
}
/* Set multicast hops val to the socket. */
int
setsockopt_ipv6_checksum (int sock, int val)
{
int ret;
#ifdef GNU_LINUX
ret = setsockopt(sock, IPPROTO_RAW, IPV6_CHECKSUM, &val, sizeof(val));
#else
ret = setsockopt(sock, IPPROTO_IPV6, IPV6_CHECKSUM, &val, sizeof(val));
#endif /* GNU_LINUX */
if (ret < 0)
zlog_warn ("can't setsockopt IPV6_CHECKSUM");
return ret;
}
/* Set multicast hops val to the socket. */
int
setsockopt_ipv6_multicast_hops (int sock, int val)
{
int ret;
ret = setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &val, sizeof(val));
if (ret < 0)
zlog_warn ("can't setsockopt IPV6_MULTICAST_HOPS");
return ret;
}
/* Set multicast hops val to the socket. */
int
setsockopt_ipv6_unicast_hops (int sock, int val)
{
int ret;
ret = setsockopt(sock, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &val, sizeof(val));
if (ret < 0)
zlog_warn ("can't setsockopt IPV6_UNICAST_HOPS");
return ret;
}
int
setsockopt_ipv6_hoplimit (int sock, int val)
{
int ret;
#ifdef IPV6_RECVHOPLIMIT /*2292bis-01*/
ret = setsockopt (sock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &val, sizeof(val));
if (ret < 0)
zlog_warn ("can't setsockopt IPV6_RECVHOPLIMIT");
#else /*RFC2292*/
ret = setsockopt (sock, IPPROTO_IPV6, IPV6_HOPLIMIT, &val, sizeof(val));
if (ret < 0)
zlog_warn ("can't setsockopt IPV6_HOPLIMIT");
#endif
return ret;
}
/* Set multicast loop zero to the socket. */
int
setsockopt_ipv6_multicast_loop (int sock, int val)
{
int ret;
ret = setsockopt (sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val,
sizeof (val));
if (ret < 0)
zlog_warn ("can't setsockopt IPV6_MULTICAST_LOOP");
return ret;
}
static int
getsockopt_ipv6_ifindex (struct msghdr *msgh)
{
struct in6_pktinfo *pktinfo;
pktinfo = getsockopt_cmsg_data (msgh, IPPROTO_IPV6, IPV6_PKTINFO);
return pktinfo->ipi6_ifindex;
}
#endif /* HAVE_IPV6 */
/*
* Process multicast socket options for IPv4 in an OS-dependent manner.
* Supported options are IP_MULTICAST_IF and IP_{ADD,DROP}_MEMBERSHIP.
*
* Many operating systems have a limit on the number of groups that
* can be joined per socket (where each group and local address
* counts). This impacts OSPF, which joins groups on each interface
* using a single socket. The limit is typically 20, derived from the
* original BSD multicast implementation. Some systems have
* mechanisms for increasing this limit.
*
* In many 4.4BSD-derived systems, multicast group operations are not
* allowed on interfaces that are not UP. Thus, a previous attempt to
* leave the group may have failed, leaving it still joined, and we
* drop/join quietly to recover. This may not be necessary, but aims to
* defend against unknown behavior in that we will still return an error
* if the second join fails. It is not clear how other systems
* (e.g. Linux, Solaris) behave when leaving groups on down interfaces,
* but this behavior should not be harmful if they behave the same way,
* allow leaves, or implicitly leave all groups joined to down interfaces.
*/
int
setsockopt_multicast_ipv4(int sock,
int optname,
struct in_addr if_addr,
unsigned int mcast_addr,
unsigned int ifindex)
{
#ifdef HAVE_STRUCT_IP_MREQN_IMR_IFINDEX
/* This is better because it uses ifindex directly */
struct ip_mreqn mreqn;
int ret;
switch (optname)
{
case IP_MULTICAST_IF:
case IP_ADD_MEMBERSHIP:
case IP_DROP_MEMBERSHIP:
memset (&mreqn, 0, sizeof(mreqn));
if (mcast_addr)
mreqn.imr_multiaddr.s_addr = mcast_addr;
if (ifindex)
mreqn.imr_ifindex = ifindex;
else
mreqn.imr_address = if_addr;
ret = setsockopt(sock, IPPROTO_IP, optname,
(void *)&mreqn, sizeof(mreqn));
if ((ret < 0) && (optname == IP_ADD_MEMBERSHIP) && (errno == EADDRINUSE))
{
/* see above: handle possible problem when interface comes back up */
char buf[2][INET_ADDRSTRLEN];
zlog_info("setsockopt_multicast_ipv4 attempting to drop and "
"re-add (fd %d, ifaddr %s, mcast %s, ifindex %u)",
sock,
inet_ntop(AF_INET, &if_addr, buf[0], sizeof(buf[0])),
inet_ntop(AF_INET, &mreqn.imr_multiaddr,
buf[1], sizeof(buf[1])), ifindex);
setsockopt(sock, IPPROTO_IP, IP_DROP_MEMBERSHIP,
(void *)&mreqn, sizeof(mreqn));
ret = setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP,
(void *)&mreqn, sizeof(mreqn));
}
return ret;
break;
default:
/* Can out and give an understandable error */
errno = EINVAL;
return -1;
break;
}
/* Example defines for another OS, boilerplate off other code in this
function, AND handle optname as per other sections for consistency !! */
/* #elif defined(BOGON_NIX) && EXAMPLE_VERSION_CODE > -100000 */
/* Add your favourite OS here! */
#else /* #if OS_TYPE */
/* standard BSD API */
struct in_addr m;
struct ip_mreq mreq;
int ret;
#ifdef HAVE_BSD_STRUCT_IP_MREQ_HACK
if (ifindex)
m.s_addr = htonl(ifindex);
else
#endif
m = if_addr;
switch (optname)
{
case IP_MULTICAST_IF:
return setsockopt (sock, IPPROTO_IP, optname, (void *)&m, sizeof(m));
break;
case IP_ADD_MEMBERSHIP:
case IP_DROP_MEMBERSHIP:
memset (&mreq, 0, sizeof(mreq));
mreq.imr_multiaddr.s_addr = mcast_addr;
mreq.imr_interface = m;
ret = setsockopt (sock, IPPROTO_IP, optname, (void *)&mreq, sizeof(mreq));
if ((ret < 0) && (optname == IP_ADD_MEMBERSHIP) && (errno == EADDRINUSE))
{
/* see above: handle possible problem when interface comes back up */
char buf[2][INET_ADDRSTRLEN];
zlog_info("setsockopt_multicast_ipv4 attempting to drop and "
"re-add (fd %d, ifaddr %s, mcast %s, ifindex %u)",
sock,
inet_ntop(AF_INET, &if_addr, buf[0], sizeof(buf[0])),
inet_ntop(AF_INET, &mreq.imr_multiaddr,
buf[1], sizeof(buf[1])), ifindex);
setsockopt (sock, IPPROTO_IP, IP_DROP_MEMBERSHIP,
(void *)&mreq, sizeof(mreq));
ret = setsockopt (sock, IPPROTO_IP, IP_ADD_MEMBERSHIP,
(void *)&mreq, sizeof(mreq));
}
return ret;
break;
default:
/* Can out and give an understandable error */
errno = EINVAL;
return -1;
break;
}
#endif /* #if OS_TYPE */
}
static int
setsockopt_ipv4_ifindex (int sock, int val)
{
int ret;
#if defined (IP_PKTINFO)
if ((ret = setsockopt (sock, IPPROTO_IP, IP_PKTINFO, &val, sizeof (val))) < 0)
zlog_warn ("Can't set IP_PKTINFO option for fd %d to %d: %s",
sock,val,safe_strerror(errno));
#elif defined (IP_RECVIF)
if ((ret = setsockopt (sock, IPPROTO_IP, IP_RECVIF, &val, sizeof (val))) < 0)
zlog_warn ("Can't set IP_RECVIF option for fd %d to %d: %s",
sock,val,safe_strerror(errno));
#else
#warning "Neither IP_PKTINFO nor IP_RECVIF is available."
#warning "Will not be able to receive link info."
#warning "Things might be seriously broken.."
/* XXX Does this ever happen? Should there be a zlog_warn message here? */
ret = -1;
#endif
return ret;
}
int
setsockopt_ifindex (int af, int sock, int val)
{
int ret = -1;
switch (af)
{
case AF_INET:
ret = setsockopt_ipv4_ifindex (sock, val);
break;
#ifdef HAVE_IPV6
case AF_INET6:
ret = setsockopt_ipv6_pktinfo (sock, val);
break;
#endif
default:
zlog_warn ("setsockopt_ifindex: unknown address family %d", af);
}
return ret;
}
/*
* Requires: msgh is not NULL and points to a valid struct msghdr, which
* may or may not have control data about the incoming interface.
*
* Returns the interface index (small integer >= 1) if it can be
* determined, or else 0.
*/
static int
getsockopt_ipv4_ifindex (struct msghdr *msgh)
{
/* XXX: initialize to zero? (Always overwritten, so just cosmetic.) */
int ifindex = -1;
#if defined(IP_PKTINFO)
/* Linux pktinfo based ifindex retrieval */
struct in_pktinfo *pktinfo;
pktinfo =
(struct in_pktinfo *)getsockopt_cmsg_data (msgh, IPPROTO_IP, IP_PKTINFO);
/* XXX Can pktinfo be NULL? Clean up post 0.98. */
ifindex = pktinfo->ipi_ifindex;
#elif defined(IP_RECVIF)
/* retrieval based on IP_RECVIF */
#ifndef SUNOS_5
/* BSD systems use a sockaddr_dl as the control message payload. */
struct sockaddr_dl *sdl;
#else
/* SUNOS_5 uses an integer with the index. */
int *ifindex_p;
#endif /* SUNOS_5 */
#ifndef SUNOS_5
/* BSD */
sdl =
(struct sockaddr_dl *)getsockopt_cmsg_data (msgh, IPPROTO_IP, IP_RECVIF);
if (sdl != NULL)
ifindex = sdl->sdl_index;
else
ifindex = 0;
#else
/*
* Solaris. On Solaris 8, IP_RECVIF is defined, but the call to
* enable it fails with errno=99, and the struct msghdr has
* controllen 0.
*/
ifindex_p = (uint_t *)getsockopt_cmsg_data (msgh, IPPROTO_IP, IP_RECVIF);
if (ifindex_p != NULL)
ifindex = *ifindex_p;
else
ifindex = 0;
#endif /* SUNOS_5 */
#else
/*
* Neither IP_PKTINFO nor IP_RECVIF defined - warn at compile time.
* XXX Decide if this is a core service, or if daemons have to cope.
* Since Solaris 8 and OpenBSD seem not to provide it, it seems that
* daemons have to cope.
*/
#warning "getsockopt_ipv4_ifindex: Neither IP_PKTINFO nor IP_RECVIF defined."
#warning "Some daemons may fail to operate correctly!"
ifindex = 0;
#endif /* IP_PKTINFO */
return ifindex;
}
/* return ifindex, 0 if none found */
int
getsockopt_ifindex (int af, struct msghdr *msgh)
{
int ifindex = 0;
switch (af)
{
case AF_INET:
return (getsockopt_ipv4_ifindex (msgh));
break;
#ifdef HAVE_IPV6
case AF_INET6:
return (getsockopt_ipv6_ifindex (msgh));
break;
#endif
default:
zlog_warn ("getsockopt_ifindex: unknown address family %d", af);
return (ifindex = 0);
}
}
/* swab iph between order system uses for IP_HDRINCL and host order */
void
sockopt_iphdrincl_swab_htosys (struct ip *iph)
{
/* BSD and derived take iph in network order, except for
* ip_len and ip_off
*/
#ifndef HAVE_IP_HDRINCL_BSD_ORDER
iph->ip_len = htons(iph->ip_len);
iph->ip_off = htons(iph->ip_off);
#endif /* HAVE_IP_HDRINCL_BSD_ORDER */
iph->ip_id = htons(iph->ip_id);
}
void
sockopt_iphdrincl_swab_systoh (struct ip *iph)
{
#ifndef HAVE_IP_HDRINCL_BSD_ORDER
iph->ip_len = ntohs(iph->ip_len);
iph->ip_off = ntohs(iph->ip_off);
#endif /* HAVE_IP_HDRINCL_BSD_ORDER */
iph->ip_id = ntohs(iph->ip_id);
}
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