[people/ms/dnsmasq.git] / src / netlink.c

/* dnsmasq is Copyright (c) 2000-2015 Simon Kelley

   This program 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; version 2 dated June, 1991, or
   (at your option) version 3 dated 29 June, 2007.
 
   This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "dnsmasq.h"

#ifdef HAVE_LINUX_NETWORK

#include <linux/types.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>

/* linux 2.6.19 buggers up the headers, patch it up here. */ 
#ifndef IFA_RTA
#  define IFA_RTA(r)  \
       ((struct rtattr*)(((char*)(r)) + NLMSG_ALIGN(sizeof(struct ifaddrmsg))))

#  include <linux/if_addr.h>
#endif

#ifndef NDA_RTA
#  define NDA_RTA(r) ((struct rtattr*)(((char*)(r)) + NLMSG_ALIGN(sizeof(struct ndmsg)))) 
#endif 


static struct iovec iov;
static u32 netlink_pid;

static void nl_async(struct nlmsghdr *h);

void netlink_init(void)
{
  struct sockaddr_nl addr;
  socklen_t slen = sizeof(addr);

  addr.nl_family = AF_NETLINK;
  addr.nl_pad = 0;
  addr.nl_pid = 0; /* autobind */
  addr.nl_groups = RTMGRP_IPV4_ROUTE;
  if (option_bool(OPT_CLEVERBIND))
    addr.nl_groups |= RTMGRP_IPV4_IFADDR;  
#ifdef HAVE_IPV6
  addr.nl_groups |= RTMGRP_IPV6_ROUTE;
  if (option_bool(OPT_CLEVERBIND))
    addr.nl_groups |= RTMGRP_IPV6_IFADDR;
#endif
#ifdef HAVE_DHCP6
  if (daemon->doing_ra || daemon->doing_dhcp6)
    addr.nl_groups |= RTMGRP_IPV6_IFADDR;
#endif
  
  /* May not be able to have permission to set multicast groups don't die in that case */
  if ((daemon->netlinkfd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE)) != -1)
    {
      if (bind(daemon->netlinkfd, (struct sockaddr *)&addr, sizeof(addr)) == -1)
	{
	  addr.nl_groups = 0;
	  if (errno != EPERM || bind(daemon->netlinkfd, (struct sockaddr *)&addr, sizeof(addr)) == -1)
	    daemon->netlinkfd = -1;
	}
    }
  
  if (daemon->netlinkfd == -1 || 
      getsockname(daemon->netlinkfd, (struct sockaddr *)&addr, &slen) == 1)
    die(_("cannot create netlink socket: %s"), NULL, EC_MISC);
   
  /* save pid assigned by bind() and retrieved by getsockname() */ 
  netlink_pid = addr.nl_pid;
  
  iov.iov_len = 100;
  iov.iov_base = safe_malloc(iov.iov_len);
}

static ssize_t netlink_recv(void)
{
  struct msghdr msg;
  struct sockaddr_nl nladdr;
  ssize_t rc;

  while (1)
    {
      msg.msg_control = NULL;
      msg.msg_controllen = 0;
      msg.msg_name = &nladdr;
      msg.msg_namelen = sizeof(nladdr);
      msg.msg_iov = &iov;
      msg.msg_iovlen = 1;
      msg.msg_flags = 0;
      
      while ((rc = recvmsg(daemon->netlinkfd, &msg, MSG_PEEK | MSG_TRUNC)) == -1 && errno == EINTR);
      
      /* make buffer big enough */
      if (rc != -1 && (msg.msg_flags & MSG_TRUNC))
	{
	  /* Very new Linux kernels return the actual size needed, older ones always return truncated size */
	  if ((size_t)rc == iov.iov_len)
	    {
	      if (expand_buf(&iov, rc + 100))
		continue;
	    }
	  else
	    expand_buf(&iov, rc);
	}

      /* read it for real */
      msg.msg_flags = 0;
      while ((rc = recvmsg(daemon->netlinkfd, &msg, 0)) == -1 && errno == EINTR);
      
      /* Make sure this is from the kernel */
      if (rc == -1 || nladdr.nl_pid == 0)
	break;
    }
      
  /* discard stuff which is truncated at this point (expand_buf() may fail) */
  if (msg.msg_flags & MSG_TRUNC)
    {
      rc = -1;
      errno = ENOMEM;
    }
  
  return rc;
}
  

/* family = AF_UNSPEC finds ARP table entries.
   family = AF_LOCAL finds MAC addresses. */
int iface_enumerate(int family, void *parm, int (*callback)())
{
  struct sockaddr_nl addr;
  struct nlmsghdr *h;
  ssize_t len;
  static unsigned int seq = 0;
  int callback_ok = 1;

  struct {
    struct nlmsghdr nlh;
    struct rtgenmsg g; 
  } req;

  addr.nl_family = AF_NETLINK;
  addr.nl_pad = 0;
  addr.nl_groups = 0;
  addr.nl_pid = 0; /* address to kernel */
 
 again: 
  if (family == AF_UNSPEC)
    req.nlh.nlmsg_type = RTM_GETNEIGH;
  else if (family == AF_LOCAL)
    req.nlh.nlmsg_type = RTM_GETLINK;
  else
    req.nlh.nlmsg_type = RTM_GETADDR;

  req.nlh.nlmsg_len = sizeof(req);
  req.nlh.nlmsg_flags = NLM_F_ROOT | NLM_F_MATCH | NLM_F_REQUEST | NLM_F_ACK; 
  req.nlh.nlmsg_pid = 0;
  req.nlh.nlmsg_seq = ++seq;
  req.g.rtgen_family = family; 

  /* Don't block in recvfrom if send fails */
  while(retry_send(sendto(daemon->netlinkfd, (void *)&req, sizeof(req), 0, 
			  (struct sockaddr *)&addr, sizeof(addr))));

  if (errno != 0)
    return 0;
    
  while (1)
    {
      if ((len = netlink_recv()) == -1)
	{
	  if (errno == ENOBUFS)
	    {
	      sleep(1);
	      goto again;
	    }
	  return 0;
	}

      for (h = (struct nlmsghdr *)iov.iov_base; NLMSG_OK(h, (size_t)len); h = NLMSG_NEXT(h, len))
	if (h->nlmsg_seq != seq || h->nlmsg_pid != netlink_pid || h->nlmsg_type == NLMSG_ERROR)
	  {
	    /* May be multicast arriving async */
	    nl_async(h);
	  }
	else if (h->nlmsg_type == NLMSG_DONE)
	  return callback_ok;
	else if (h->nlmsg_type == RTM_NEWADDR && family != AF_UNSPEC && family != AF_LOCAL)
	  {
	    struct ifaddrmsg *ifa = NLMSG_DATA(h);  
	    struct rtattr *rta = IFA_RTA(ifa);
	    unsigned int len1 = h->nlmsg_len - NLMSG_LENGTH(sizeof(*ifa));
	    
	    if (ifa->ifa_family == family)
	      {
		if (ifa->ifa_family == AF_INET)
		  {
		    struct in_addr netmask, addr, broadcast;
		    char *label = NULL;

		    netmask.s_addr = htonl(~(in_addr_t)0 << (32 - ifa->ifa_prefixlen));

		    addr.s_addr = 0;
		    broadcast.s_addr = 0;
		    
		    while (RTA_OK(rta, len1))
		      {
			if (rta->rta_type == IFA_LOCAL)
			  addr = *((struct in_addr *)(rta+1));
			else if (rta->rta_type == IFA_BROADCAST)
			  broadcast = *((struct in_addr *)(rta+1));
			else if (rta->rta_type == IFA_LABEL)
			  label = RTA_DATA(rta);
			
			rta = RTA_NEXT(rta, len1);
		      }
		    
		    if (addr.s_addr && callback_ok)
		      if (!((*callback)(addr, ifa->ifa_index, label,  netmask, broadcast, parm)))
			callback_ok = 0;
		  }
#ifdef HAVE_IPV6
		else if (ifa->ifa_family == AF_INET6)
		  {
		    struct in6_addr *addrp = NULL;
		    u32 valid = 0, preferred = 0;
		    int flags = 0;
		    
		    while (RTA_OK(rta, len1))
		      {
			if (rta->rta_type == IFA_ADDRESS)
			  addrp = ((struct in6_addr *)(rta+1)); 
			else if (rta->rta_type == IFA_CACHEINFO)
			  {
			    struct ifa_cacheinfo *ifc = (struct ifa_cacheinfo *)(rta+1);
			    preferred = ifc->ifa_prefered;
			    valid = ifc->ifa_valid;
			  }
			rta = RTA_NEXT(rta, len1);
		      }
		    
		    if (ifa->ifa_flags & IFA_F_TENTATIVE)
		      flags |= IFACE_TENTATIVE;
		    
		    if (ifa->ifa_flags & IFA_F_DEPRECATED)
		      flags |= IFACE_DEPRECATED;
		    
		    if (!(ifa->ifa_flags & IFA_F_TEMPORARY))
		      flags |= IFACE_PERMANENT;
    		    
		    if (addrp && callback_ok)
		      if (!((*callback)(addrp, (int)(ifa->ifa_prefixlen), (int)(ifa->ifa_scope), 
					(int)(ifa->ifa_index), flags, 
					(int) preferred, (int)valid, parm)))
			callback_ok = 0;
		  }
#endif
	      }
	  }
	else if (h->nlmsg_type == RTM_NEWNEIGH && family == AF_UNSPEC)
	  {
	    struct ndmsg *neigh = NLMSG_DATA(h);  
	    struct rtattr *rta = NDA_RTA(neigh);
	    unsigned int len1 = h->nlmsg_len - NLMSG_LENGTH(sizeof(*neigh));
	    size_t maclen = 0;
	    char *inaddr = NULL, *mac = NULL;
	    
	    while (RTA_OK(rta, len1))
	      {
		if (rta->rta_type == NDA_DST)
		  inaddr = (char *)(rta+1);
		else if (rta->rta_type == NDA_LLADDR)
		  {
		    maclen = rta->rta_len - sizeof(struct rtattr);
		    mac = (char *)(rta+1);
		  }
		
		rta = RTA_NEXT(rta, len1);
	      }

	    if (inaddr && mac && callback_ok)
	      if (!((*callback)(neigh->ndm_family, inaddr, mac, maclen, parm)))
		callback_ok = 0;
	  }
#ifdef HAVE_DHCP6
	else if (h->nlmsg_type == RTM_NEWLINK && family == AF_LOCAL)
	  {
	    struct ifinfomsg *link =  NLMSG_DATA(h);
	    struct rtattr *rta = IFLA_RTA(link);
	    unsigned int len1 = h->nlmsg_len - NLMSG_LENGTH(sizeof(*link));
	    char *mac = NULL;
	    size_t maclen = 0;

	    while (RTA_OK(rta, len1))
	      {
		if (rta->rta_type == IFLA_ADDRESS)
		  {
		    maclen = rta->rta_len - sizeof(struct rtattr);
		    mac = (char *)(rta+1);
		  }
		
		rta = RTA_NEXT(rta, len1);
	      }

	    if (mac && callback_ok && !((link->ifi_flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) && 
		!((*callback)((int)link->ifi_index, (unsigned int)link->ifi_type, mac, maclen, parm)))
	      callback_ok = 0;
	  }
#endif
    }
}

void netlink_multicast(void)
{
  ssize_t len;
  struct nlmsghdr *h;
  int flags;
  
  /* don't risk blocking reading netlink messages here. */
  if ((flags = fcntl(daemon->netlinkfd, F_GETFL)) == -1 ||
      fcntl(daemon->netlinkfd, F_SETFL, flags | O_NONBLOCK) == -1) 
    return;
  
  if ((len = netlink_recv()) != -1)
    for (h = (struct nlmsghdr *)iov.iov_base; NLMSG_OK(h, (size_t)len); h = NLMSG_NEXT(h, len))
      nl_async(h);
  
  /* restore non-blocking status */
  fcntl(daemon->netlinkfd, F_SETFL, flags);
}

static void nl_async(struct nlmsghdr *h)
{
  if (h->nlmsg_type == NLMSG_ERROR)
    {
      struct nlmsgerr *err = NLMSG_DATA(h);
      if (err->error != 0)
	my_syslog(LOG_ERR, _("netlink returns error: %s"), strerror(-(err->error)));
    }
  else if (h->nlmsg_pid == 0 && h->nlmsg_type == RTM_NEWROUTE) 
    {
      /* We arrange to receive netlink multicast messages whenever the network route is added.
	 If this happens and we still have a DNS packet in the buffer, we re-send it.
	 This helps on DoD links, where frequently the packet which triggers dialling is
	 a DNS query, which then gets lost. By re-sending, we can avoid the lookup
	 failing. */ 
      struct rtmsg *rtm = NLMSG_DATA(h);
      
      if (rtm->rtm_type == RTN_UNICAST && rtm->rtm_scope == RT_SCOPE_LINK)
	queue_event(EVENT_NEWROUTE);
    }
  else if (h->nlmsg_type == RTM_NEWADDR || h->nlmsg_type == RTM_DELADDR) 
    queue_event(EVENT_NEWADDR);
}
#endif
Commit	Line	Data
aff33962	1	/* dnsmasq is Copyright (c) 2000-2015 Simon Kelley
0a852541 SK	2
	3	This program is free software; you can redistribute it and/or modify
	4	it under the terms of the GNU General Public License as published by
824af85b SK	5	the Free Software Foundation; version 2 dated June, 1991, or
	6	(at your option) version 3 dated 29 June, 2007.
	7
0a852541 SK	8	This program is distributed in the hope that it will be useful,
	9	but WITHOUT ANY WARRANTY; without even the implied warranty of
	10	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	11	GNU General Public License for more details.
824af85b	12
73a08a24 SK	13	You should have received a copy of the GNU General Public License
73a08a24 SK	14	along with this program. If not, see <http://www.gnu.org/licenses/>.
0a852541 SK	15	*/
0a852541 SK	16
0a852541 SK	17	#include "dnsmasq.h"
0a852541 SK	18
5e9e0efb	19	#ifdef HAVE_LINUX_NETWORK
0a852541	20
91dccd09	21	#include <linux/types.h>
0a852541 SK	22	#include <linux/netlink.h>
	23	#include <linux/rtnetlink.h>
	24
832af0ba SK	25	/* linux 2.6.19 buggers up the headers, patch it up here. */
	26	#ifndef IFA_RTA
	27	# define IFA_RTA(r) \
	28	((struct rtattr)(((char)(r)) + NLMSG_ALIGN(sizeof(struct ifaddrmsg))))
	29
	30	# include <linux/if_addr.h>
	31	#endif
	32
28866e95 SK	33	#ifndef NDA_RTA
	34	# define NDA_RTA(r) ((struct rtattr)(((char)(r)) + NLMSG_ALIGN(sizeof(struct ndmsg))))
	35	#endif
	36
c72daea8	37
5e9e0efb	38	static struct iovec iov;
7622fc06	39	static u32 netlink_pid;
5e9e0efb	40
a0358e5d	41	static void nl_async(struct nlmsghdr *h);
cdeda28f	42
5aabfc78	43	void netlink_init(void)
0a852541 SK	44	{
0a852541 SK	45	struct sockaddr_nl addr;
7622fc06	46	socklen_t slen = sizeof(addr);
0a852541 SK	47
	48	addr.nl_family = AF_NETLINK;
	49	addr.nl_pad = 0;
5e9e0efb	50	addr.nl_pid = 0; /* autobind */
5e9e0efb	51	addr.nl_groups = RTMGRP_IPV4_ROUTE;
54dd393f	52	if (option_bool(OPT_CLEVERBIND))
1f776932	53	addr.nl_groups \|= RTMGRP_IPV4_IFADDR;
54dd393f SK	54	#ifdef HAVE_IPV6
54dd393f SK	55	addr.nl_groups \|= RTMGRP_IPV6_ROUTE;
1f776932 SK	56	if (option_bool(OPT_CLEVERBIND))
	57	addr.nl_groups \|= RTMGRP_IPV6_IFADDR;
	58	#endif
	59	#ifdef HAVE_DHCP6
	60	if (daemon->doing_ra \|\| daemon->doing_dhcp6)
54dd393f	61	addr.nl_groups \|= RTMGRP_IPV6_IFADDR;
cdeda28f	62	#endif
0a852541	63
309331f5 SK	64	/* May not be able to have permission to set multicast groups don't die in that case */
	65	if ((daemon->netlinkfd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE)) != -1)
	66	{
	67	if (bind(daemon->netlinkfd, (struct sockaddr *)&addr, sizeof(addr)) == -1)
	68	{
	69	addr.nl_groups = 0;
	70	if (errno != EPERM \|\| bind(daemon->netlinkfd, (struct sockaddr *)&addr, sizeof(addr)) == -1)
	71	daemon->netlinkfd = -1;
	72	}
	73	}
	74
7622fc06 SK	75	if (daemon->netlinkfd == -1 \|\|
7622fc06 SK	76	getsockname(daemon->netlinkfd, (struct sockaddr *)&addr, &slen) == 1)
5aabfc78	77	die(_("cannot create netlink socket: %s"), NULL, EC_MISC);
7622fc06 SK	78
	79	/* save pid assigned by bind() and retrieved by getsockname() */
	80	netlink_pid = addr.nl_pid;
5aabfc78	81
7622fc06	82	iov.iov_len = 100;
5e9e0efb	83	iov.iov_base = safe_malloc(iov.iov_len);
0a852541 SK	84	}
0a852541 SK	85
5aabfc78	86	static ssize_t netlink_recv(void)
cdeda28f SK	87	{
cdeda28f SK	88	struct msghdr msg;
7622fc06	89	struct sockaddr_nl nladdr;
cdeda28f SK	90	ssize_t rc;
cdeda28f SK	91
5e9e0efb	92	while (1)
cdeda28f	93	{
7622fc06 SK	94	msg.msg_control = NULL;
	95	msg.msg_controllen = 0;
	96	msg.msg_name = &nladdr;
	97	msg.msg_namelen = sizeof(nladdr);
	98	msg.msg_iov = &iov;
	99	msg.msg_iovlen = 1;
5e9e0efb	100	msg.msg_flags = 0;
5e9e0efb	101
7622fc06 SK	102	while ((rc = recvmsg(daemon->netlinkfd, &msg, MSG_PEEK \| MSG_TRUNC)) == -1 && errno == EINTR);
	103
	104	/* make buffer big enough */
	105	if (rc != -1 && (msg.msg_flags & MSG_TRUNC))
5e9e0efb	106	{
7622fc06 SK	107	/* Very new Linux kernels return the actual size needed, older ones always return truncated size */
	108	if ((size_t)rc == iov.iov_len)
	109	{
	110	if (expand_buf(&iov, rc + 100))
	111	continue;
	112	}
	113	else
	114	expand_buf(&iov, rc);
5e9e0efb	115	}
7622fc06 SK	116
	117	/* read it for real */
	118	msg.msg_flags = 0;
	119	while ((rc = recvmsg(daemon->netlinkfd, &msg, 0)) == -1 && errno == EINTR);
5e9e0efb	120
7622fc06 SK	121	/* Make sure this is from the kernel */
	122	if (rc == -1 \|\| nladdr.nl_pid == 0)
	123	break;
	124	}
	125
	126	/* discard stuff which is truncated at this point (expand_buf() may fail) */
	127	if (msg.msg_flags & MSG_TRUNC)
	128	{
	129	rc = -1;
	130	errno = ENOMEM;
cdeda28f	131	}
cdeda28f SK	132
	133	return rc;
	134	}
	135
28866e95	136
c72daea8 SK	137	/* family = AF_UNSPEC finds ARP table entries.
c72daea8 SK	138	family = AF_LOCAL finds MAC addresses. */
28866e95	139	int iface_enumerate(int family, void parm, int (callback)())
0a852541 SK	140	{
	141	struct sockaddr_nl addr;
	142	struct nlmsghdr *h;
cdeda28f	143	ssize_t len;
0a852541	144	static unsigned int seq = 0;
a0358e5d	145	int callback_ok = 1;
0a852541 SK	146
	147	struct {
	148	struct nlmsghdr nlh;
	149	struct rtgenmsg g;
	150	} req;
	151
0a852541 SK	152	addr.nl_family = AF_NETLINK;
	153	addr.nl_pad = 0;
	154	addr.nl_groups = 0;
	155	addr.nl_pid = 0; /* address to kernel */
c72daea8 SK	156
	157	again:
	158	if (family == AF_UNSPEC)
	159	req.nlh.nlmsg_type = RTM_GETNEIGH;
	160	else if (family == AF_LOCAL)
	161	req.nlh.nlmsg_type = RTM_GETLINK;
	162	else
	163	req.nlh.nlmsg_type = RTM_GETADDR;
0a852541 SK	164
0a852541 SK	165	req.nlh.nlmsg_len = sizeof(req);
7cebd20f	166	req.nlh.nlmsg_flags = NLM_F_ROOT \| NLM_F_MATCH \| NLM_F_REQUEST \| NLM_F_ACK;
0a852541 SK	167	req.nlh.nlmsg_pid = 0;
0a852541 SK	168	req.nlh.nlmsg_seq = ++seq;
5e9e0efb	169	req.g.rtgen_family = family;
0a852541 SK	170
0a852541 SK	171	/* Don't block in recvfrom if send fails */
ff841ebf SK	172	while(retry_send(sendto(daemon->netlinkfd, (void *)&req, sizeof(req), 0,
	173	(struct sockaddr *)&addr, sizeof(addr))));
	174
	175	if (errno != 0)
5e9e0efb SK	176	return 0;
	177
	178	while (1)
0a852541	179	{
5aabfc78	180	if ((len = netlink_recv()) == -1)
7622fc06 SK	181	{
	182	if (errno == ENOBUFS)
	183	{
	184	sleep(1);
	185	goto again;
	186	}
	187	return 0;
	188	}
	189
5e9e0efb	190	for (h = (struct nlmsghdr *)iov.iov_base; NLMSG_OK(h, (size_t)len); h = NLMSG_NEXT(h, len))
54dd393f SK	191	if (h->nlmsg_seq != seq \|\| h->nlmsg_pid != netlink_pid \|\| h->nlmsg_type == NLMSG_ERROR)
	192	{
	193	/* May be multicast arriving async */
a0358e5d	194	nl_async(h);
54dd393f	195	}
5e9e0efb	196	else if (h->nlmsg_type == NLMSG_DONE)
a0358e5d	197	return callback_ok;
c72daea8	198	else if (h->nlmsg_type == RTM_NEWADDR && family != AF_UNSPEC && family != AF_LOCAL)
5e9e0efb SK	199	{
	200	struct ifaddrmsg *ifa = NLMSG_DATA(h);
	201	struct rtattr *rta = IFA_RTA(ifa);
	202	unsigned int len1 = h->nlmsg_len - NLMSG_LENGTH(sizeof(*ifa));
	203
28866e95	204	if (ifa->ifa_family == family)
5e9e0efb	205	{
28866e95	206	if (ifa->ifa_family == AF_INET)
5e9e0efb	207	{
28866e95	208	struct in_addr netmask, addr, broadcast;
3f2873d4 SK	209	char *label = NULL;
3f2873d4 SK	210
10cfc0dd RG	211	netmask.s_addr = htonl(~(in_addr_t)0 << (32 - ifa->ifa_prefixlen));
10cfc0dd RG	212
28866e95 SK	213	addr.s_addr = 0;
28866e95 SK	214	broadcast.s_addr = 0;
5e9e0efb	215
28866e95 SK	216	while (RTA_OK(rta, len1))
	217	{
	218	if (rta->rta_type == IFA_LOCAL)
	219	addr = ((struct in_addr )(rta+1));
	220	else if (rta->rta_type == IFA_BROADCAST)
	221	broadcast = ((struct in_addr )(rta+1));
3f2873d4 SK	222	else if (rta->rta_type == IFA_LABEL)
3f2873d4 SK	223	label = RTA_DATA(rta);
28866e95 SK	224
	225	rta = RTA_NEXT(rta, len1);
	226	}
	227
e44ddcac	228	if (addr.s_addr && callback_ok)
3f2873d4	229	if (!((*callback)(addr, ifa->ifa_index, label, netmask, broadcast, parm)))
e44ddcac	230	callback_ok = 0;
5e9e0efb	231	}
5e9e0efb	232	#ifdef HAVE_IPV6
28866e95	233	else if (ifa->ifa_family == AF_INET6)
5e9e0efb	234	{
28866e95	235	struct in6_addr *addrp = NULL;
1f776932	236	u32 valid = 0, preferred = 0;
bad7b875 SK	237	int flags = 0;
bad7b875 SK	238
28866e95 SK	239	while (RTA_OK(rta, len1))
	240	{
	241	if (rta->rta_type == IFA_ADDRESS)
	242	addrp = ((struct in6_addr *)(rta+1));
1f776932 SK	243	else if (rta->rta_type == IFA_CACHEINFO)
	244	{
	245	struct ifa_cacheinfo ifc = (struct ifa_cacheinfo )(rta+1);
	246	preferred = ifc->ifa_prefered;
	247	valid = ifc->ifa_valid;
	248	}
28866e95 SK	249	rta = RTA_NEXT(rta, len1);
28866e95 SK	250	}
5e9e0efb	251
bad7b875 SK	252	if (ifa->ifa_flags & IFA_F_TENTATIVE)
	253	flags \|= IFACE_TENTATIVE;
	254
	255	if (ifa->ifa_flags & IFA_F_DEPRECATED)
	256	flags \|= IFACE_DEPRECATED;
	257
57ab36e7 JG	258	if (!(ifa->ifa_flags & IFA_F_TEMPORARY))
	259	flags \|= IFACE_PERMANENT;
	260
e44ddcac	261	if (addrp && callback_ok)
52b92f4d	262	if (!((*callback)(addrp, (int)(ifa->ifa_prefixlen), (int)(ifa->ifa_scope),
bad7b875	263	(int)(ifa->ifa_index), flags,
1f776932	264	(int) preferred, (int)valid, parm)))
e44ddcac	265	callback_ok = 0;
5e9e0efb	266	}
5e9e0efb	267	#endif
28866e95	268	}
5e9e0efb	269	}
28866e95 SK	270	else if (h->nlmsg_type == RTM_NEWNEIGH && family == AF_UNSPEC)
	271	{
	272	struct ndmsg *neigh = NLMSG_DATA(h);
	273	struct rtattr *rta = NDA_RTA(neigh);
	274	unsigned int len1 = h->nlmsg_len - NLMSG_LENGTH(sizeof(*neigh));
	275	size_t maclen = 0;
	276	char inaddr = NULL, mac = NULL;
	277
	278	while (RTA_OK(rta, len1))
	279	{
	280	if (rta->rta_type == NDA_DST)
	281	inaddr = (char *)(rta+1);
	282	else if (rta->rta_type == NDA_LLADDR)
	283	{
	284	maclen = rta->rta_len - sizeof(struct rtattr);
	285	mac = (char *)(rta+1);
	286	}
	287
	288	rta = RTA_NEXT(rta, len1);
	289	}
	290
e44ddcac	291	if (inaddr && mac && callback_ok)
28866e95	292	if (!((*callback)(neigh->ndm_family, inaddr, mac, maclen, parm)))
e44ddcac	293	callback_ok = 0;
c72daea8 SK	294	}
	295	#ifdef HAVE_DHCP6
	296	else if (h->nlmsg_type == RTM_NEWLINK && family == AF_LOCAL)
	297	{
	298	struct ifinfomsg *link = NLMSG_DATA(h);
	299	struct rtattr *rta = IFLA_RTA(link);
	300	unsigned int len1 = h->nlmsg_len - NLMSG_LENGTH(sizeof(*link));
	301	char *mac = NULL;
	302	size_t maclen = 0;
	303
	304	while (RTA_OK(rta, len1))
	305	{
	306	if (rta->rta_type == IFLA_ADDRESS)
	307	{
	308	maclen = rta->rta_len - sizeof(struct rtattr);
	309	mac = (char *)(rta+1);
	310	}
	311
	312	rta = RTA_NEXT(rta, len1);
	313	}
	314
e44ddcac	315	if (mac && callback_ok && !((link->ifi_flags & (IFF_LOOPBACK \| IFF_POINTOPOINT))) &&
c5ad4e79	316	!((*callback)((int)link->ifi_index, (unsigned int)link->ifi_type, mac, maclen, parm)))
e44ddcac	317	callback_ok = 0;
c72daea8 SK	318	}
c72daea8 SK	319	#endif
0a852541	320	}
5e9e0efb	321	}
0a852541	322
a0358e5d	323	void netlink_multicast(void)
5e9e0efb SK	324	{
	325	ssize_t len;
	326	struct nlmsghdr *h;
a0358e5d	327	int flags;
7622fc06 SK	328
	329	/* don't risk blocking reading netlink messages here. */
	330	if ((flags = fcntl(daemon->netlinkfd, F_GETFL)) == -1 \|\|
	331	fcntl(daemon->netlinkfd, F_SETFL, flags \| O_NONBLOCK) == -1)
	332	return;
0a852541	333
5aabfc78	334	if ((len = netlink_recv()) != -1)
54dd393f	335	for (h = (struct nlmsghdr *)iov.iov_base; NLMSG_OK(h, (size_t)len); h = NLMSG_NEXT(h, len))
a0358e5d	336	nl_async(h);
54dd393f SK	337
	338	/* restore non-blocking status */
	339	fcntl(daemon->netlinkfd, F_SETFL, flags);
0a852541 SK	340	}
0a852541 SK	341
a0358e5d	342	static void nl_async(struct nlmsghdr *h)
5e9e0efb	343	{
54dd393f SK	344	if (h->nlmsg_type == NLMSG_ERROR)
	345	{
	346	struct nlmsgerr *err = NLMSG_DATA(h);
dfb23b3f SK	347	if (err->error != 0)
dfb23b3f SK	348	my_syslog(LOG_ERR, _("netlink returns error: %s"), strerror(-(err->error)));
54dd393f SK	349	}
	350	else if (h->nlmsg_pid == 0 && h->nlmsg_type == RTM_NEWROUTE)
	351	{
e17b4b38 SK	352	/* We arrange to receive netlink multicast messages whenever the network route is added.
	353	If this happens and we still have a DNS packet in the buffer, we re-send it.
	354	This helps on DoD links, where frequently the packet which triggers dialling is
	355	a DNS query, which then gets lost. By re-sending, we can avoid the lookup
	356	failing. */
	357	struct rtmsg *rtm = NLMSG_DATA(h);
	358
	359	if (rtm->rtm_type == RTN_UNICAST && rtm->rtm_scope == RT_SCOPE_LINK)
47a95169	360	queue_event(EVENT_NEWROUTE);
54dd393f	361	}
1f776932	362	else if (h->nlmsg_type == RTM_NEWADDR \|\| h->nlmsg_type == RTM_DELADDR)
47a95169	363	queue_event(EVENT_NEWADDR);
54dd393f	364	}
0a852541 SK	365	#endif
	366
	367