393 lines
8.9 KiB
C
393 lines
8.9 KiB
C
/*
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* Network availability and change notifications for linux.
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*
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* Authors:
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* Gonzalo Paniagua Javier (gonzalo@novell.com)
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*
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* Copyright (c) Novell, Inc. 2011
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*/
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#ifdef HAVE_CONFIG_H
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#include <config.h>
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#endif
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#include "nl.h"
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#if defined(HAVE_LINUX_NETLINK_H) && defined(HAVE_LINUX_RTNETLINK_H)
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#include <errno.h>
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#include <unistd.h>
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#include <fcntl.h>
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <arpa/inet.h>
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#include <linux/netlink.h>
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#include <linux/rtnetlink.h>
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#undef NL_DEBUG
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#define NL_DEBUG_STMT(a) do { } while (0)
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#define NL_DEBUG_PRINT(...)
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/*
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#define NL_DEBUG 1
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#define NL_DEBUG_STMT(a) do { a } while (0)
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#define NL_DEBUG_PRINT(...) g_message(__VA_ARGS__)
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*/
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#ifdef AF_INET6
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#define ADDR_BYTE_LENGTH 16
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#define ADDR_STR_LENGTH INET6_ADDRSTRLEN
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#else
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#define ADDR_LENGTH 4
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#define ADDR_STR_LENGTH INET_ADDRSTRLEN
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#endif
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enum event_type {
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EVT_NONE = 0,
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#define EVT_NONE 0
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EVT_AVAILABILITY = 1 << 0,
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#define EVT_AVAILABILITY (1 << 0)
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EVT_ADDRESS = 1 << 1,
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#define EVT_ADDRESS (1 << 1)
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EVT_ALL = EVT_AVAILABILITY | EVT_ADDRESS
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#define EVT_ALL (EVT_AVAILABILITY | EVT_ADDRESS)
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};
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#ifdef NL_DEBUG
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typedef struct {
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int value;
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const char *name;
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} value2name_t;
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#define INIT(x) { x, #x }
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#define FIND_NAME(a, b) value_to_name (a, b)
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#define FIND_RT_TYPE_NAME(b) FIND_NAME (rt_types, b)
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static value2name_t rt_types [] = {
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INIT (RTM_NEWROUTE),
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INIT (RTM_DELROUTE),
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INIT (RTM_GETROUTE),
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INIT (RTM_NEWADDR),
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INIT (RTM_DELADDR),
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INIT (RTM_GETADDR),
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INIT (RTM_NEWLINK),
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INIT (RTM_GETLINK),
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INIT (RTM_DELLINK),
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INIT (RTM_NEWNEIGH),
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INIT (RTM_GETNEIGH),
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INIT (RTM_DELNEIGH),
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{0, NULL}
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};
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#define FIND_RTM_TYPE_NAME(b) FIND_NAME (rtm_types, b)
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static value2name_t rtm_types [] = {
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INIT (RTN_UNSPEC),
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INIT (RTN_UNICAST),
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INIT (RTN_LOCAL),
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INIT (RTN_BROADCAST),
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INIT (RTN_ANYCAST),
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INIT (RTN_MULTICAST),
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INIT (RTN_BLACKHOLE),
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INIT (RTN_UNREACHABLE),
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INIT (RTN_PROHIBIT),
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INIT (RTN_THROW),
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INIT (RTN_NAT),
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INIT (RTN_XRESOLVE),
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{0, NULL}
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};
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#define FIND_RTM_PROTO_NAME(b) FIND_NAME (rtm_protocols, b)
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static value2name_t rtm_protocols[] = {
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INIT (RTPROT_UNSPEC),
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INIT (RTPROT_REDIRECT),
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INIT (RTPROT_KERNEL),
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INIT (RTPROT_BOOT),
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INIT (RTPROT_STATIC),
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{0, NULL}
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};
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#define FIND_RTM_SCOPE_NAME(b) FIND_NAME (rtm_scopes, b)
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static value2name_t rtm_scopes [] = {
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INIT (RT_SCOPE_UNIVERSE),
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INIT (RT_SCOPE_SITE),
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INIT (RT_SCOPE_LINK),
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INIT (RT_SCOPE_HOST),
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INIT (RT_SCOPE_NOWHERE),
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{0, NULL}
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};
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#define FIND_RTM_ATTRS_NAME(b) FIND_NAME (rtm_attrs, b)
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static value2name_t rtm_attrs [] = {
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INIT (RTA_UNSPEC),
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INIT (RTA_DST),
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INIT (RTA_SRC),
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INIT (RTA_IIF),
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INIT (RTA_OIF),
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INIT (RTA_GATEWAY),
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INIT (RTA_PRIORITY),
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INIT (RTA_PREFSRC),
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INIT (RTA_METRICS),
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INIT (RTA_MULTIPATH),
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INIT (RTA_PROTOINFO),
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INIT (RTA_FLOW),
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INIT (RTA_CACHEINFO),
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INIT (RTA_SESSION),
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INIT (RTA_MP_ALGO),
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INIT (RTA_TABLE),
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{0, NULL}
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};
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#define FIND_RT_TABLE_NAME(b) FIND_NAME (rtm_tables, b)
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static value2name_t rtm_tables [] = {
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INIT (RT_TABLE_UNSPEC),
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INIT (RT_TABLE_COMPAT),
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INIT (RT_TABLE_DEFAULT),
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INIT (RT_TABLE_MAIN),
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INIT (RT_TABLE_LOCAL),
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{0,0}
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};
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static const char *
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value_to_name (value2name_t *tbl, int value)
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{
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static char auto_name [16];
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while (tbl->name) {
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if (tbl->value == value)
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return tbl->name;
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tbl++;
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}
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snprintf (auto_name, sizeof (auto_name), "#%d", value);
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return auto_name;
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}
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#endif /* NL_DEBUG */
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int
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CreateNLSocket (void)
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{
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int sock;
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struct sockaddr_nl sa;
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int ret;
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sock = socket (AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
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ret = fcntl (sock, F_GETFL, 0);
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if (ret != -1) {
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ret |= O_NONBLOCK;
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ret = fcntl (sock, F_SETFL, ret);
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if (ret < 0)
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return -1;
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}
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memset (&sa, 0, sizeof (sa));
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if (sock < 0)
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return -1;
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sa.nl_family = AF_NETLINK;
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sa.nl_pid = getpid ();
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sa.nl_groups = RTMGRP_IPV4_ROUTE | RTMGRP_IPV6_ROUTE | RTMGRP_NOTIFY;
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/* RTNLGRP_IPV4_IFADDR | RTNLGRP_IPV6_IFADDR
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* RTMGRP_LINK */
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if (bind (sock, (struct sockaddr *) &sa, sizeof (sa)) < 0)
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return -1;
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return sock;
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}
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int
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ReadEvents (gpointer sock, gpointer buffer, gint32 count, gint32 size)
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{
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struct nlmsghdr *nlp;
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struct rtmsg *rtp;
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int rtl;
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struct rtattr *rtap;
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int result;
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int s;
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NL_DEBUG_PRINT ("ENTER ReadEvents()");
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result = EVT_NONE;
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s = GPOINTER_TO_INT (sock);
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/* This socket is not found by IO layer, so we do everything here */
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if (count == 0) {
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while ((count = recv (s, buffer, size, 0)) == -1 && errno == EINTR);
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if (count <= 0) {
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NL_DEBUG_PRINT ("EXIT ReadEvents()");
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return result;
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}
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}
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for (nlp = (struct nlmsghdr *) buffer; NLMSG_OK (nlp, count); nlp = NLMSG_NEXT (nlp, count)) {
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int family;
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int addr_length;
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int msg_type;
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int table;
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#ifdef NL_DEBUG
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int protocol;
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int scope;
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#endif
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int rtm_type;
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gboolean have_dst;
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gboolean have_src;
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gboolean have_pref_src;
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gboolean have_gw;
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char dst [ADDR_BYTE_LENGTH];
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char src [ADDR_BYTE_LENGTH];
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char pref_src [ADDR_BYTE_LENGTH];
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char gw [ADDR_BYTE_LENGTH];
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msg_type = nlp->nlmsg_type;
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NL_DEBUG_PRINT ("TYPE: %d %s", msg_type, FIND_RT_TYPE_NAME (msg_type));
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if (msg_type != RTM_NEWROUTE && msg_type != RTM_DELROUTE)
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continue;
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rtp = (struct rtmsg *) NLMSG_DATA (nlp);
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family = rtp->rtm_family;
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#ifdef AF_INET6
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if (family != AF_INET && family != AF_INET6) {
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#else
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if (family != AF_INET) {
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#endif
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continue;
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}
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addr_length = (family == AF_INET) ? 4 : 16;
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table = rtp->rtm_table;
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#ifdef NL_DEBUG
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protocol = rtp->rtm_protocol;
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scope = rtp->rtm_scope;
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#endif
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rtm_type = rtp->rtm_type;
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NL_DEBUG_PRINT ("\tRTMSG table: %d %s", table, FIND_RT_TABLE_NAME (table));
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if (table != RT_TABLE_MAIN && table != RT_TABLE_LOCAL)
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continue;
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NL_DEBUG_PRINT ("\tRTMSG protocol: %d %s", protocol, FIND_RTM_PROTO_NAME (protocol));
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NL_DEBUG_PRINT ("\tRTMSG scope: %d %s", scope, FIND_RTM_SCOPE_NAME (scope));
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NL_DEBUG_PRINT ("\tRTMSG type: %d %s", rtm_type, FIND_RTM_TYPE_NAME (rtm_type));
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rtap = (struct rtattr *) RTM_RTA (rtp);
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rtl = RTM_PAYLOAD (nlp);
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// loop & get every attribute
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//
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//
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// NEW_ROUTE
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// table = RT_TABLE_LOCAL, Scope = HOST + pref.src == src + type=LOCAL -> new if addr
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// RT_TABLE_MAIN, Scope = Universe, unicast, gateway exists -> NEW default route
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// DEL_ROUTE
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// table = RT_TABLE_LOCAL, Scope = HOST, perfsrc = dst + type=LOCAL -> if addr deleted
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// RT_TABLE_MAIN - DELROUTE + unicast -> event (gw down?)
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have_dst = have_src = have_pref_src = have_gw = FALSE;
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for(; RTA_OK (rtap, rtl); rtap = RTA_NEXT(rtap, rtl)) {
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char *data;
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#ifdef NL_DEBUG
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char ip [ADDR_STR_LENGTH];
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#endif
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NL_DEBUG_PRINT ("\tAttribute: %d %d (%s)", rtap->rta_len, rtap->rta_type, FIND_RTM_ATTRS_NAME (rtap->rta_type));
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data = RTA_DATA (rtap);
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switch (rtap->rta_type) {
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case RTA_DST:
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have_dst = TRUE;
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memcpy (dst, data, addr_length);
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NL_DEBUG_STMT (
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*ip = 0;
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inet_ntop (family, RTA_DATA (rtap), ip, sizeof (ip));
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NL_DEBUG_PRINT ("\t\tDst: %s", ip);
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);
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break;
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case RTA_PREFSRC:
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have_pref_src = TRUE;
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memcpy (pref_src, data, addr_length);
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NL_DEBUG_STMT (
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*ip = 0;
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inet_ntop (family, RTA_DATA (rtap), ip, sizeof (ip));
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NL_DEBUG_PRINT ("\t\tPref. Src.: %s", ip);
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);
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break;
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case RTA_SRC:
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have_src = TRUE;
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memcpy (src, data, addr_length);
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NL_DEBUG_STMT (
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*ip = 0;
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inet_ntop (family, RTA_DATA (rtap), ip, sizeof (ip));
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NL_DEBUG_PRINT ("\tSrc: %s", ip);
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);
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break;
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case RTA_GATEWAY:
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have_gw = TRUE;
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memcpy (gw, data, addr_length);
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NL_DEBUG_STMT (
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*ip = 0;
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inet_ntop (family, RTA_DATA (rtap), ip, sizeof (ip));
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NL_DEBUG_PRINT ("\t\tGateway: %s", ip);
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);
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break;
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default:
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break;
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}
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}
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if (msg_type == RTM_NEWROUTE) {
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if (table == RT_TABLE_MAIN) {
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NL_DEBUG_PRINT ("NEWROUTE: Availability changed");
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result |= EVT_AVAILABILITY;
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} else if (table == RT_TABLE_LOCAL) {
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NL_DEBUG_PRINT ("NEWROUTE: new IP");
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if (have_dst && have_pref_src && memcmp (dst, pref_src, addr_length) == 0)
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result |= EVT_ADDRESS;
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}
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} else if (msg_type == RTM_DELROUTE) {
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if (table == RT_TABLE_MAIN) {
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if (rtm_type == RTN_UNICAST && (have_dst || have_pref_src)) {
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result |= EVT_AVAILABILITY;
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NL_DEBUG_PRINT ("DELROUTE: Availability changed");
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}
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} else if (table == RT_TABLE_LOCAL) {
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if (have_dst && have_pref_src && memcmp (dst, pref_src, addr_length) == 0) {
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result |= EVT_ADDRESS;
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NL_DEBUG_PRINT ("DELROUTE: deleted IP");
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}
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}
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}
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while ((count = recv (s, buffer, size, 0)) == -1 && errno == EINTR);
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if (count <= 0) {
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NL_DEBUG_PRINT ("EXIT ReadEvents() -> %d", result);
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return result;
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}
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nlp = (struct nlmsghdr *) buffer;
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}
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NL_DEBUG_PRINT ("EXIT ReadEvents() -> %d", result);
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return result;
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}
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int
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CloseNLSocket (gpointer sock)
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{
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return close (GPOINTER_TO_INT (sock));
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}
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#else
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int
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GetNLSocket (void)
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{
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return -1;
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}
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int
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ReadEvents (gpointer sock, gpointer buffer, gint32 count, gint32 size)
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{
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return 0;
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}
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int
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CreateNLSocket (void)
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{
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return -1;
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}
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int
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CloseNLSocket (gpointer sock)
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{
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return -1;
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}
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#endif /* linux/netlink.h + linux/rtnetlink.h */
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