1ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat/* dnsmasq is Copyright (c) 2000-2009 Simon Kelley 2ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 3ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat This program is free software; you can redistribute it and/or modify 4ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat it under the terms of the GNU General Public License as published by 5ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat the Free Software Foundation; version 2 dated June, 1991, or 6ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat (at your option) version 3 dated 29 June, 2007. 7ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 8ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat This program is distributed in the hope that it will be useful, 9ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat but WITHOUT ANY WARRANTY; without even the implied warranty of 10ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat GNU General Public License for more details. 12ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 13ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat You should have received a copy of the GNU General Public License 14ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat along with this program. If not, see <http://www.gnu.org/licenses/>. 15ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat*/ 16ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 17ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat#include "dnsmasq.h" 18ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 19ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat#ifdef HAVE_LINUX_NETWORK 20ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 21ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat#include <linux/types.h> 22ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat#include <linux/netlink.h> 23ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat#include <linux/rtnetlink.h> 24ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 25ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat/* linux 2.6.19 buggers up the headers, patch it up here. */ 26ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat#ifndef IFA_RTA 27ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat# define IFA_RTA(r) \ 28ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat ((struct rtattr*)(((char*)(r)) + NLMSG_ALIGN(sizeof(struct ifaddrmsg)))) 29ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 30ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat# include <linux/if_addr.h> 31ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat#endif 32ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 33ffd68729961f7383f2e35494a03ccdef20f86c98San Mehatstatic struct iovec iov; 34ffd68729961f7383f2e35494a03ccdef20f86c98San Mehatstatic u32 netlink_pid; 35ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 36ffd68729961f7383f2e35494a03ccdef20f86c98San Mehatstatic void nl_err(struct nlmsghdr *h); 37ffd68729961f7383f2e35494a03ccdef20f86c98San Mehatstatic void nl_routechange(struct nlmsghdr *h); 38ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 39ffd68729961f7383f2e35494a03ccdef20f86c98San Mehatvoid netlink_init(void) 40ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat{ 41ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat struct sockaddr_nl addr; 42ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat socklen_t slen = sizeof(addr); 43ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 44ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat addr.nl_family = AF_NETLINK; 45ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat addr.nl_pad = 0; 46ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat addr.nl_pid = 0; /* autobind */ 47ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat#ifdef HAVE_IPV6 48ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat addr.nl_groups = RTMGRP_IPV4_ROUTE | RTMGRP_IPV6_ROUTE; 49ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat#else 50ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat addr.nl_groups = RTMGRP_IPV4_ROUTE; 51ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat#endif 52ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 53ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat /* May not be able to have permission to set multicast groups don't die in that case */ 54ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if ((daemon->netlinkfd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE)) != -1) 55ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat { 56ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if (bind(daemon->netlinkfd, (struct sockaddr *)&addr, sizeof(addr)) == -1) 57ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat { 58ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat addr.nl_groups = 0; 59ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if (errno != EPERM || bind(daemon->netlinkfd, (struct sockaddr *)&addr, sizeof(addr)) == -1) 60ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat daemon->netlinkfd = -1; 61ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat } 62ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat } 63ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 64ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if (daemon->netlinkfd == -1 || 65ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat getsockname(daemon->netlinkfd, (struct sockaddr *)&addr, &slen) == 1) 66ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat die(_("cannot create netlink socket: %s"), NULL, EC_MISC); 67ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 68ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat /* save pid assigned by bind() and retrieved by getsockname() */ 69ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat netlink_pid = addr.nl_pid; 70ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 71ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat iov.iov_len = 100; 72ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat iov.iov_base = safe_malloc(iov.iov_len); 73ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat} 74ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 75ffd68729961f7383f2e35494a03ccdef20f86c98San Mehatstatic ssize_t netlink_recv(void) 76ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat{ 77ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat struct msghdr msg; 78ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat struct sockaddr_nl nladdr; 79ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat ssize_t rc; 80ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 81ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat while (1) 82ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat { 83ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat msg.msg_control = NULL; 84ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat msg.msg_controllen = 0; 85ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat msg.msg_name = &nladdr; 86ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat msg.msg_namelen = sizeof(nladdr); 87ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat msg.msg_iov = &iov; 88ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat msg.msg_iovlen = 1; 89ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat msg.msg_flags = 0; 90ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 91ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat while ((rc = recvmsg(daemon->netlinkfd, &msg, MSG_PEEK | MSG_TRUNC)) == -1 && errno == EINTR); 92ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 93ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat /* make buffer big enough */ 94ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if (rc != -1 && (msg.msg_flags & MSG_TRUNC)) 95ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat { 96ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat /* Very new Linux kernels return the actual size needed, older ones always return truncated size */ 97ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if ((size_t)rc == iov.iov_len) 98ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat { 99ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if (expand_buf(&iov, rc + 100)) 100ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat continue; 101ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat } 102ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat else 103ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat expand_buf(&iov, rc); 104ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat } 105ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 106ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat /* read it for real */ 107ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat msg.msg_flags = 0; 108ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat while ((rc = recvmsg(daemon->netlinkfd, &msg, 0)) == -1 && errno == EINTR); 109ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 110ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat /* Make sure this is from the kernel */ 111ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if (rc == -1 || nladdr.nl_pid == 0) 112ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat break; 113ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat } 114ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 115ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat /* discard stuff which is truncated at this point (expand_buf() may fail) */ 116ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if (msg.msg_flags & MSG_TRUNC) 117ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat { 118ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat rc = -1; 119ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat errno = ENOMEM; 120ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat } 121ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 122ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat return rc; 123ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat} 124ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 125ffd68729961f7383f2e35494a03ccdef20f86c98San Mehatint iface_enumerate(void *parm, int (*ipv4_callback)(), int (*ipv6_callback)()) 126ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat{ 127ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat struct sockaddr_nl addr; 128ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat struct nlmsghdr *h; 129ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat ssize_t len; 130ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat static unsigned int seq = 0; 131ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat int family = AF_INET; 132ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 133ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat struct { 134ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat struct nlmsghdr nlh; 135ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat struct rtgenmsg g; 136ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat } req; 137ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 138ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat addr.nl_family = AF_NETLINK; 139ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat addr.nl_pad = 0; 140ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat addr.nl_groups = 0; 141ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat addr.nl_pid = 0; /* address to kernel */ 142ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 143ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat again: 144ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat req.nlh.nlmsg_len = sizeof(req); 145ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat req.nlh.nlmsg_type = RTM_GETADDR; 146ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat req.nlh.nlmsg_flags = NLM_F_ROOT | NLM_F_MATCH | NLM_F_REQUEST | NLM_F_ACK; 147ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat req.nlh.nlmsg_pid = 0; 148ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat req.nlh.nlmsg_seq = ++seq; 149ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat req.g.rtgen_family = family; 150ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 151ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat /* Don't block in recvfrom if send fails */ 152ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat while((len = sendto(daemon->netlinkfd, (void *)&req, sizeof(req), 0, 153ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat (struct sockaddr *)&addr, sizeof(addr))) == -1 && retry_send()); 154ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 155ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if (len == -1) 156ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat return 0; 157ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 158ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat while (1) 159ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat { 160ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if ((len = netlink_recv()) == -1) 161ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat { 162ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if (errno == ENOBUFS) 163ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat { 164ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat sleep(1); 165ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat goto again; 166ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat } 167ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat return 0; 168ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat } 169ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 170ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat for (h = (struct nlmsghdr *)iov.iov_base; NLMSG_OK(h, (size_t)len); h = NLMSG_NEXT(h, len)) 171ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if (h->nlmsg_seq != seq || h->nlmsg_pid != netlink_pid) 172ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat nl_routechange(h); /* May be multicast arriving async */ 173ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat else if (h->nlmsg_type == NLMSG_ERROR) 174ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat nl_err(h); 175ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat else if (h->nlmsg_type == NLMSG_DONE) 176ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat { 177ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat#ifdef HAVE_IPV6 178ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if (family == AF_INET && ipv6_callback) 179ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat { 180ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat family = AF_INET6; 181ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat goto again; 182ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat } 183ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat#endif 184ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat return 1; 185ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat } 186ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat else if (h->nlmsg_type == RTM_NEWADDR) 187ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat { 188ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat struct ifaddrmsg *ifa = NLMSG_DATA(h); 189ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat struct rtattr *rta = IFA_RTA(ifa); 190ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat unsigned int len1 = h->nlmsg_len - NLMSG_LENGTH(sizeof(*ifa)); 191ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 192ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if (ifa->ifa_family == AF_INET) 193ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat { 194ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat struct in_addr netmask, addr, broadcast; 195ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 196ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat netmask.s_addr = htonl(0xffffffff << (32 - ifa->ifa_prefixlen)); 197ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat addr.s_addr = 0; 198ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat broadcast.s_addr = 0; 199ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 200ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat while (RTA_OK(rta, len1)) 201ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat { 202ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if (rta->rta_type == IFA_LOCAL) 203ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat addr = *((struct in_addr *)(rta+1)); 204ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat else if (rta->rta_type == IFA_BROADCAST) 205ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat broadcast = *((struct in_addr *)(rta+1)); 206ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 207ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat rta = RTA_NEXT(rta, len1); 208ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat } 209ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 210ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if (addr.s_addr && ipv4_callback) 211ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if (!((*ipv4_callback)(addr, ifa->ifa_index, netmask, broadcast, parm))) 212ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat return 0; 213ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat } 214ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat#ifdef HAVE_IPV6 215ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat else if (ifa->ifa_family == AF_INET6) 216ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat { 217ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat struct in6_addr *addrp = NULL; 218ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat while (RTA_OK(rta, len1)) 219ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat { 220ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if (rta->rta_type == IFA_ADDRESS) 221ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat addrp = ((struct in6_addr *)(rta+1)); 222ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 223ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat rta = RTA_NEXT(rta, len1); 224ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat } 225ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 226ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if (addrp && ipv6_callback) 227ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if (!((*ipv6_callback)(addrp, ifa->ifa_index, ifa->ifa_index, parm))) 228ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat return 0; 229ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat } 230ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat#endif 231ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat } 232ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat } 233ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat} 234ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 235ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 236ffd68729961f7383f2e35494a03ccdef20f86c98San Mehatvoid netlink_multicast(void) 237ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat{ 238ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat ssize_t len; 239ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat struct nlmsghdr *h; 240ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat int flags; 241ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 242ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat /* don't risk blocking reading netlink messages here. */ 243ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if ((flags = fcntl(daemon->netlinkfd, F_GETFL)) == -1 || 244ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat fcntl(daemon->netlinkfd, F_SETFL, flags | O_NONBLOCK) == -1) 245ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat return; 246ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 247ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if ((len = netlink_recv()) != -1) 248ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat { 249ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat for (h = (struct nlmsghdr *)iov.iov_base; NLMSG_OK(h, (size_t)len); h = NLMSG_NEXT(h, len)) 250ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if (h->nlmsg_type == NLMSG_ERROR) 251ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat nl_err(h); 252ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat else 253ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat nl_routechange(h); 254ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat } 255ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 256ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat /* restore non-blocking status */ 257ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat fcntl(daemon->netlinkfd, F_SETFL, flags); 258ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat} 259ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 260ffd68729961f7383f2e35494a03ccdef20f86c98San Mehatstatic void nl_err(struct nlmsghdr *h) 261ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat{ 262ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat struct nlmsgerr *err = NLMSG_DATA(h); 263ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 264ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if (err->error != 0) 265ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat my_syslog(LOG_ERR, _("netlink returns error: %s"), strerror(-(err->error))); 266ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat} 267ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 268ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat/* We arrange to receive netlink multicast messages whenever the network route is added. 269ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat If this happens and we still have a DNS packet in the buffer, we re-send it. 270ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat This helps on DoD links, where frequently the packet which triggers dialling is 271ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat a DNS query, which then gets lost. By re-sending, we can avoid the lookup 272ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat failing. Note that we only accept these messages from the kernel (pid == 0) */ 273ffd68729961f7383f2e35494a03ccdef20f86c98San Mehatstatic void nl_routechange(struct nlmsghdr *h) 274ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat{ 275ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if (h->nlmsg_pid == 0 && h->nlmsg_type == RTM_NEWROUTE) 276ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat { 277ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat struct rtmsg *rtm = NLMSG_DATA(h); 278ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat int fd; 279ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 280ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if (rtm->rtm_type != RTN_UNICAST || rtm->rtm_scope != RT_SCOPE_LINK) 281ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat return; 282ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 283ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat /* Force re-reading resolv file right now, for luck. */ 284ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat daemon->last_resolv = 0; 285ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 286ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if (daemon->srv_save) 287ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat { 288ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat if (daemon->srv_save->sfd) 289ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat fd = daemon->srv_save->sfd->fd; 290ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat else if (daemon->rfd_save && daemon->rfd_save->refcount != 0) 291ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat fd = daemon->rfd_save->fd; 292ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat else 293ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat return; 294ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 295ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat while(sendto(fd, daemon->packet, daemon->packet_len, 0, 296ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat &daemon->srv_save->addr.sa, sa_len(&daemon->srv_save->addr)) == -1 && retry_send()); 297ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat } 298ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat } 299ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat} 300ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 301ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat#endif 302ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 303ffd68729961f7383f2e35494a03ccdef20f86c98San Mehat 304