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/* $NetBSD: socketops.c,v 1.36 2022/06/26 17:55:38 riastradh Exp $ */
/*
* Copyright (c) 2010 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Mihai Chelaru <kefren@NetBSD.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <assert.h>
#include <errno.h>
#include <ifaddrs.h>
#include <poll.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <unistd.h>
#include "conffile.h"
#include "fsm.h"
#include "ldp.h"
#include "ldp_command.h"
#include "tlv.h"
#include "ldp_peer.h"
#include "notifications.h"
#include "tlv_stack.h"
#include "mpls_interface.h"
#include "label.h"
#include "mpls_routes.h"
#include "ldp_errors.h"
#include "socketops.h"
struct hello_info_head hello_info_head;
static SLIST_HEAD(,hello_socket) hello_socket_head;
int ls; /* TCP listening socket on port 646 */
int route_socket; /* used to see when a route is added/deleted */
int command_socket; /* Listening socket for interface command */
int current_msg_id = 0x233;
int command_port = LDP_COMMAND_PORT;
extern int replay_index;
extern struct rt_msg replay_rt[REPLAY_MAX];
extern struct com_sock csockets[MAX_COMMAND_SOCKETS];
int ldp_hello_time = LDP_HELLO_TIME;
int ldp_keepalive_time = LDP_KEEPALIVE_TIME;
int ldp_holddown_time = LDP_HOLDTIME;
int no_default_route = 1;
int loop_detection = 0;
bool may_connect;
void recv_pdu(int);
void send_hello_alarm(int);
__dead static void bail_out(int);
static void print_info(int);
static int bind_socket(int s, int stype);
static int set_tos(int);
static int socket_reuse_port(int);
static int get_local_addr(struct sockaddr_dl *, struct in_addr *);
static int is_hello_socket(int);
static int is_passive_if(const char *if_name);
int
create_hello_sockets()
{
struct ip_mreq mcast_addr;
int s, joined_groups;
struct ifaddrs *ifa, *ifb;
uint lastifindex;
#ifdef INET6
struct ipv6_mreq mcast_addr6;
struct sockaddr_in6 *if_sa6;
#endif
struct hello_socket *hs;
SLIST_INIT(&hello_socket_head);
s = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
if (s < 0)
return s;
debugp("INET4 socket created (%d)\n", s);
/*
* RFC5036 specifies we should listen to all subnet routers multicast
* group
*/
mcast_addr.imr_multiaddr.s_addr = htonl(INADDR_ALLRTRS_GROUP);
if (socket_reuse_port(s) < 0)
goto chs_error;
/* Bind it to port 646 */
if (bind_socket(s, AF_INET) == -1) {
warnp("Cannot bind INET hello socket\n");
goto chs_error;
}
/* We don't need to receive back our messages */
if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_LOOP, &(u_char){0},
sizeof(u_char)) == -1) {
fatalp("INET setsockopt IP_MCAST_LOOP: %s\n", strerror(errno));
goto chs_error;
}
/* Finally join the group on all interfaces */
if (getifaddrs(&ifa) == -1) {
fatalp("Cannot iterate interfaces\n");
return -1;
}
lastifindex = UINT_MAX;
joined_groups = 0;
for (ifb = ifa; ifb; ifb = ifb->ifa_next) {
struct sockaddr_in *if_sa = (struct sockaddr_in *) ifb->ifa_addr;
if (if_sa->sin_family != AF_INET || (!(ifb->ifa_flags & IFF_UP)) ||
(ifb->ifa_flags & IFF_LOOPBACK) ||
(!(ifb->ifa_flags & IFF_MULTICAST)) ||
(ntohl(if_sa->sin_addr.s_addr) >> 24 == IN_LOOPBACKNET) ||
is_passive_if(ifb->ifa_name) ||
lastifindex == if_nametoindex(ifb->ifa_name))
continue;
lastifindex = if_nametoindex(ifb->ifa_name);
mcast_addr.imr_interface.s_addr = if_sa->sin_addr.s_addr;
debugp("Join IPv4 mcast on %s\n", ifb->ifa_name);
if (setsockopt(s, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char *) &mcast_addr,
sizeof(mcast_addr)) == -1) {
fatalp("setsockopt ADD_MEMBER: %s\n", strerror(errno));
goto chs_error;
}
joined_groups++;
if (joined_groups == IP_MAX_MEMBERSHIPS) {
warnp("Maximum group memberships reached for INET socket\n");
break;
}
}
/* TTL:1 for IPv4 */
if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL, &(int){1},
sizeof(int)) == -1) {
fatalp("set mcast ttl: %s\n", strerror(errno));
goto chs_error;
}
/* TOS :0xc0 for IPv4 */
if (set_tos(s) == -1) {
fatalp("set_tos: %s", strerror(errno));
goto chs_error;
}
/* we need to get the input interface for message processing */
if (setsockopt(s, IPPROTO_IP, IP_RECVIF, &(uint32_t){1},
sizeof(uint32_t)) == -1) {
fatalp("Cannot set IP_RECVIF\n");
goto chs_error;
}
hs = (struct hello_socket *)malloc(sizeof(*hs));
if (hs == NULL) {
fatalp("Cannot alloc hello_socket structure\n");
goto chs_error;
}
hs->type = AF_INET;
hs->socket = s;
SLIST_INSERT_HEAD(&hello_socket_head, hs, listentry);
#ifdef INET6
/*
* Now we do the same for IPv6
*/
s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_UDP);
if (s < 0) {
fatalp("Cannot create INET6 socket\n");
return -1;
}
debugp("INET6 socket created (%d)\n", s);
if (socket_reuse_port(s) < 0)
goto chs_error;
if (bind_socket(s, AF_INET6) == -1) {
fatalp("Cannot bind INET6 hello socket\n");
goto chs_error;
}
if (setsockopt(s, IPPROTO_IPV6, IPV6_MULTICAST_LOOP,
&(uint){0}, sizeof(uint)) == -1) {
fatalp("INET6 setsocketopt IP_MCAST_LOOP: %s\n",
strerror(errno));
goto chs_error;
}
lastifindex = UINT_MAX;
mcast_addr6.ipv6mr_multiaddr = in6addr_linklocal_allrouters;
for (ifb = ifa; ifb; ifb = ifb->ifa_next) {
if_sa6 = (struct sockaddr_in6 *) ifb->ifa_addr;
if (if_sa6->sin6_family != AF_INET6 ||
(!(ifb->ifa_flags & IFF_UP)) ||
(!(ifb->ifa_flags & IFF_MULTICAST)) ||
(ifb->ifa_flags & IFF_LOOPBACK) ||
is_passive_if(ifb->ifa_name) ||
IN6_IS_ADDR_LOOPBACK(&if_sa6->sin6_addr))
continue;
/*
* draft-ietf-mpls-ldp-ipv6-07 Section 5.1:
* Additionally, the link-local
* IPv6 address MUST be used as the source IP address in IPv6
* LDP Link Hellos.
*/
if (IN6_IS_ADDR_LINKLOCAL(&if_sa6->sin6_addr) == 0)
continue;
/* We should have only one LLADDR per interface, but... */
if (lastifindex == if_nametoindex(ifb->ifa_name))
continue;
mcast_addr6.ipv6mr_interface = lastifindex =
if_nametoindex(ifb->ifa_name);
debugp("Join IPv6 mcast on %s\n", ifb->ifa_name);
if (setsockopt(s, IPPROTO_IPV6, IPV6_JOIN_GROUP,
(char *)&mcast_addr6, sizeof(mcast_addr6)) == -1) {
fatalp("INET6 setsockopt JOIN: %s\n", strerror(errno));
goto chs_error;
}
}
freeifaddrs(ifa);
/* TTL: 255 for IPv6 - draft-ietf-mpls-ldp-ipv6-07 Section 9 */
if (setsockopt(s, IPPROTO_IPV6, IPV6_MULTICAST_HOPS,
&(int){255}, sizeof(int)) == -1) {
fatalp("set mcast hops: %s\n", strerror(errno));
goto chs_error;
}
if (setsockopt(s, IPPROTO_IPV6, IPV6_RECVPKTINFO,
&(uint32_t){1}, sizeof(uint32_t)) == -1)
goto chs_error;
hs = (struct hello_socket *)malloc(sizeof(*hs));
if (hs == NULL) {
fatalp("Memory alloc problem: hs\n");
goto chs_error;
}
hs->type = AF_INET6;
hs->socket = s;
SLIST_INSERT_HEAD(&hello_socket_head, hs, listentry);
#endif
return 0;
chs_error:
close(s);
return -1;
}
/* Check if parameter is a hello socket */
int
is_hello_socket(int s)
{
struct hello_socket *hs;
SLIST_FOREACH(hs, &hello_socket_head, listentry)
if (hs->socket == s)
return 1;
return 0;
}
/* Check if interface is passive */
static int
is_passive_if(const char *if_name)
{
struct conf_interface *coif;
SLIST_FOREACH(coif, &coifs_head, iflist)
if (strncasecmp(if_name, coif->if_name, IF_NAMESIZE) == 0 &&
coif->passive != 0)
return 1;
return 0;
}
/* Sets the TTL to 1 as we don't want to transmit outside this subnet */
int
set_ttl(int s)
{
int ret;
if ((ret = setsockopt(s, IPPROTO_IP, IP_TTL, &(int){1}, sizeof(int)))
== -1)
fatalp("set_ttl: %s", strerror(errno));
return ret;
}
/* Sets TOS to 0xc0 aka IP Precedence 6 */
static int
set_tos(int s)
{
int ret;
if ((ret = setsockopt(s, IPPROTO_IP, IP_TOS, &(int){0xc0},
sizeof(int))) == -1)
fatalp("set_tos: %s", strerror(errno));
return ret;
}
static int
socket_reuse_port(int s)
{
int ret;
if ((ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &(int){1},
sizeof(int))) == -1)
fatalp("socket_reuse_port: %s", strerror(errno));
return ret;
}
/* binds an UDP socket */
static int
bind_socket(int s, int stype)
{
union sockunion su;
assert (stype == AF_INET || stype == AF_INET6);
memset(&su, 0, sizeof su);
if (stype == AF_INET) {
su.sin.sin_len = sizeof(su.sin);
su.sin.sin_family = AF_INET;
su.sin.sin_addr.s_addr = htonl(INADDR_ANY);
su.sin.sin_port = htons(LDP_PORT);
}
#ifdef INET6
else if (stype == AF_INET6) {
su.sin6.sin6_len = sizeof(su.sin6);
su.sin6.sin6_family = AF_INET6;
su.sin6.sin6_addr = in6addr_any;
su.sin6.sin6_port = htons(LDP_PORT);
}
#endif
if (bind(s, &su.sa, su.sa.sa_len)) {
fatalp("bind_socket: %s\n", strerror(errno));
return -1;
}
return 0;
}
/* Create / bind the TCP socket */
int
create_listening_socket(void)
{
struct sockaddr_in sa;
int s;
sa.sin_len = sizeof(sa);
sa.sin_family = AF_INET;
sa.sin_port = htons(LDP_PORT);
sa.sin_addr.s_addr = htonl(INADDR_ANY);
s = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
if (s < 0)
return s;
if (bind(s, (struct sockaddr *) & sa, sizeof(sa))) {
fatalp("bind: %s", strerror(errno));
close(s);
return -1;
}
if (listen(s, 10) == -1) {
fatalp("listen: %s", strerror(errno));
close(s);
return -1;
}
/* if (set_tos(s) == -1) {
fatalp("set_tos: %s", strerror(errno));
close(s);
return -1;
}
*/ return s;
}
/*
* It's ugly. We need a function to pass all tlvs and create pdu but since I
* use UDP socket only to send hellos, I didn't bother
*/
void
send_hello(void)
{
struct hello_tlv *t;
struct common_hello_tlv *cht;
struct ldp_pdu *spdu;
struct in_addr ldp_id;
struct transport_address_tlv *trtlv;
void *v;
struct sockaddr_in sadest; /* Destination ALL_ROUTERS */
ssize_t sb = 0; /* sent bytes */
struct ifaddrs *ifa, *ifb;
struct sockaddr_in *if_sa;
int ip4socket = -1;
uint lastifindex;
struct hello_socket *hs;
struct conf_interface *coif;
bool bad_tr_addr;
#ifdef INET6
struct sockaddr_in6 sadest6;
int ip6socket = -1;
#endif
#define BASIC_HELLO_MSG_SIZE (sizeof(struct ldp_pdu) + /* PDU */ \
TLV_TYPE_LENGTH + MSGID_SIZE + /* Hello TLV */ \
/* Common Hello TLV */ \
sizeof(struct common_hello_tlv))
#define GENERAL_HELLO_MSG_SIZE BASIC_HELLO_MSG_SIZE + \
/* Transport Address */ \
sizeof(struct transport_address_tlv)
#define IPV4_HELLO_MSG_SIZE BASIC_HELLO_MSG_SIZE + 4 + sizeof(struct in_addr)
#define IPV6_HELLO_MSG_SIZE BASIC_HELLO_MSG_SIZE + 4 + sizeof(struct in6_addr)
if ((v = calloc(1, GENERAL_HELLO_MSG_SIZE)) == NULL) {
fatalp("alloc problem in send_hello()\n");
return;
}
spdu = (struct ldp_pdu *)((char *)v);
t = (struct hello_tlv *)(spdu + 1);
cht = &t->ch; /* Hello tlv struct includes CHT */
trtlv = (struct transport_address_tlv *)(t + 1);
/* Prepare PDU envelope */
spdu->version = htons(LDP_VERSION);
spdu->length = htons(IPV4_HELLO_MSG_SIZE - PDU_VER_LENGTH);
inet_aton(LDP_ID, &ldp_id);
spdu->ldp_id = ldp_id;
/* Prepare Hello TLV */
t->type = htons(LDP_HELLO);
t->length = htons(MSGID_SIZE +
sizeof(struct common_hello_tlv) +
IPV4_HELLO_MSG_SIZE - BASIC_HELLO_MSG_SIZE);
/*
* We used ID 0 instead of htonl(get_message_id()) because we've
* seen hellos from Cisco routers doing the same thing
*/
t->messageid = 0;
/* Prepare Common Hello attributes */
cht->type = htons(TLV_COMMON_HELLO);
cht->length = htons(sizeof(cht->holdtime) + sizeof(cht->res));
cht->holdtime = htons(ldp_holddown_time);
cht->res = 0;
/*
* Prepare Transport Address TLV RFC5036 says: "If this optional TLV
* is not present the IPv4 source address for the UDP packet carrying
* the Hello should be used." But we send it because everybody seems
* to do so
*/
trtlv->type = htons(TLV_IPV4_TRANSPORT);
trtlv->length = htons(sizeof(struct in_addr));
/* trtlv->address will be set for each socket */
/* Destination sockaddr */
memset(&sadest, 0, sizeof(sadest));
sadest.sin_len = sizeof(sadest);
sadest.sin_family = AF_INET;
sadest.sin_port = htons(LDP_PORT);
sadest.sin_addr.s_addr = htonl(INADDR_ALLRTRS_GROUP);
/* Find our socket */
SLIST_FOREACH(hs, &hello_socket_head, listentry)
if (hs->type == AF_INET) {
ip4socket = hs->socket;
break;
}
assert(ip4socket >= 0);
if (getifaddrs(&ifa) == -1) {
free(v);
fatalp("Cannot enumerate interfaces\n");
return;
}
lastifindex = UINT_MAX;
/* Loop all interfaces in order to send IPv4 hellos */
for (ifb = ifa; ifb; ifb = ifb->ifa_next) {
if_sa = (struct sockaddr_in *) ifb->ifa_addr;
if (if_sa->sin_family != AF_INET ||
(!(ifb->ifa_flags & IFF_UP)) ||
(ifb->ifa_flags & IFF_LOOPBACK) ||
(!(ifb->ifa_flags & IFF_MULTICAST)) ||
is_passive_if(ifb->ifa_name) ||
(ntohl(if_sa->sin_addr.s_addr) >> 24 == IN_LOOPBACKNET) ||
lastifindex == if_nametoindex(ifb->ifa_name))
continue;
/* Send only once per interface, using primary address */
if (lastifindex == if_nametoindex(ifb->ifa_name))
continue;
/* Check if there is transport address set for this interface */
bad_tr_addr = false;
SLIST_FOREACH(coif, &coifs_head, iflist)
if (strncasecmp(coif->if_name, ifb->ifa_name,
IF_NAMESIZE) == 0 &&
coif->tr_addr.s_addr != 0 &&
coif->tr_addr.s_addr != if_sa->sin_addr.s_addr)
bad_tr_addr = true;
if (bad_tr_addr == true)
continue;
lastifindex = if_nametoindex(ifb->ifa_name);
if (setsockopt(ip4socket, IPPROTO_IP, IP_MULTICAST_IF,
&if_sa->sin_addr, sizeof(struct in_addr)) == -1) {
warnp("setsockopt failed: %s\n", strerror(errno));
continue;
}
trtlv->address.ip4addr.s_addr = if_sa->sin_addr.s_addr;
/* Put it on the wire */
sb = sendto(ip4socket, v, IPV4_HELLO_MSG_SIZE, 0,
(struct sockaddr *) & sadest, sizeof(sadest));
if (sb < (ssize_t)(IPV4_HELLO_MSG_SIZE))
fatalp("send: %s", strerror(errno));
else
debugp("Sent (IPv4) %zd bytes on %s"
" (PDU: %d, Hello TLV: %d, CH: %d, TR: %d)\n",
sb, ifb->ifa_name,
ntohs(spdu->length), ntohs(t->length),
ntohs(cht->length), ntohs(trtlv->length));
}
#ifdef INET6
/* Adjust lengths */
spdu->length = htons(IPV6_HELLO_MSG_SIZE - PDU_VER_LENGTH);
t->length = htons(MSGID_SIZE +
sizeof(struct common_hello_tlv) +
IPV6_HELLO_MSG_SIZE - BASIC_HELLO_MSG_SIZE);
trtlv->length = htons(sizeof(struct in6_addr));
trtlv->type = htons(TLV_IPV6_TRANSPORT);
/* Prepare destination sockaddr */
memset(&sadest6, 0, sizeof(sadest6));
sadest6.sin6_len = sizeof(sadest6);
sadest6.sin6_family = AF_INET6;
sadest6.sin6_port = htons(LDP_PORT);
sadest6.sin6_addr = in6addr_linklocal_allrouters;
SLIST_FOREACH(hs, &hello_socket_head, listentry)
if (hs->type == AF_INET6) {
ip6socket = hs->socket;
break;
}
lastifindex = UINT_MAX;
for (ifb = ifa; ifb; ifb = ifb->ifa_next) {
struct sockaddr_in6 * if_sa6 =
(struct sockaddr_in6 *) ifb->ifa_addr;
if (if_sa6->sin6_family != AF_INET6 ||
(!(ifb->ifa_flags & IFF_UP)) ||
(!(ifb->ifa_flags & IFF_MULTICAST)) ||
(ifb->ifa_flags & IFF_LOOPBACK) ||
is_passive_if(ifb->ifa_name) ||
IN6_IS_ADDR_LOOPBACK(&if_sa6->sin6_addr))
continue;
/*
* draft-ietf-mpls-ldp-ipv6-07 Section 5.1:
* Additionally, the link-local
* IPv6 address MUST be used as the source IP address in IPv6
* LDP Link Hellos.
*/
if (IN6_IS_ADDR_LINKLOCAL(&if_sa6->sin6_addr) == 0)
continue;
/* We should have only one LLADDR per interface, but... */
if (lastifindex == if_nametoindex(ifb->ifa_name))
continue;
lastifindex = if_nametoindex(ifb->ifa_name);
if (setsockopt(ip6socket, IPPROTO_IPV6, IPV6_MULTICAST_IF,
&lastifindex, sizeof(int)) == -1) {
fatalp("ssopt6 IPV6_MULTICAST_IF failed: %s for %s\n",
strerror(errno), ifb->ifa_name);
continue;
}
memcpy(&trtlv->address.ip6addr, &if_sa6->sin6_addr,
sizeof(struct in6_addr));
/* Put it on the wire */
sb = sendto(ip6socket, v, IPV6_HELLO_MSG_SIZE,
0, (struct sockaddr *)&sadest6, sizeof(sadest6));
if (sb < (ssize_t)(IPV6_HELLO_MSG_SIZE))
fatalp("send6: %s", strerror(errno));
else
debugp("Sent (IPv6) %zd bytes on %s "
"(PDU: %d, Hello TLV: %d, CH: %d TR: %d)\n",
sb, ifb->ifa_name, htons(spdu->length),
htons(t->length), htons(cht->length),
htons(trtlv->length));
}
#endif
freeifaddrs(ifa);
free(v);
}
int
get_message_id(void)
{
current_msg_id++;
return current_msg_id;
}
static int
get_local_addr(struct sockaddr_dl *sdl, struct in_addr *sin)
{
struct ifaddrs *ifa, *ifb;
struct sockaddr_in *sinet;
if (sdl == NULL)
return -1;
if (getifaddrs(&ifa) == -1)
return -1;
for (ifb = ifa; ifb; ifb = ifb->ifa_next)
if (ifb->ifa_addr->sa_family == AF_INET) {
if (if_nametoindex(ifb->ifa_name) != sdl->sdl_index)
continue;
sinet = (struct sockaddr_in*) ifb->ifa_addr;
sin->s_addr = sinet->sin_addr.s_addr;
freeifaddrs(ifa);
return 0;
}
freeifaddrs(ifa);
return -1;
}
/* Receive PDUs on Multicast UDP socket */
void
recv_pdu(int sock)
{
struct ldp_pdu rpdu;
int c, i;
struct msghdr msg;
struct iovec iov[1];
unsigned char recvspace[MAX_PDU_SIZE];
struct hello_tlv *t;
union sockunion sender;
struct sockaddr_dl *sdl = NULL;
struct in_addr my_ldp_addr, local_addr;
struct cmsghdr *cmptr;
union {
struct cmsghdr cm;
char control[1024];
} control_un;
memset(&msg, 0, sizeof(msg));
msg.msg_control = control_un.control;
msg.msg_controllen = sizeof(control_un.control);
msg.msg_flags = 0;
msg.msg_name = &sender;
msg.msg_namelen = sizeof(sender);
iov[0].iov_base = recvspace;
iov[0].iov_len = sizeof(recvspace);
msg.msg_iov = iov;
msg.msg_iovlen = 1;
c = recvmsg(sock, &msg, MSG_WAITALL);
/* Check to see if this is larger than MIN_PDU_SIZE */
if (c < MIN_PDU_SIZE)
return;
/* Read the PDU */
i = get_pdu(recvspace, &rpdu);
debugp("recv_pdu(%d): PDU(size: %d) from: %s\n", sock,
c, satos(&sender.sa));
/* We currently understand Version 1 */
if (rpdu.version != LDP_VERSION) {
warnp("recv_pdu: Version mismatch\n");
return;
}
/* Check if it's our hello */
inet_aton(LDP_ID, &my_ldp_addr);
if (rpdu.ldp_id.s_addr == my_ldp_addr.s_addr) {
/* It should not be looped. We set MULTICAST_LOOP 0 */
fatalp("Received our PDU. Ignoring it\n");
return;
}
if (msg.msg_controllen < (socklen_t)sizeof(struct cmsghdr) ||
(msg.msg_flags & MSG_CTRUNC))
local_addr.s_addr = my_ldp_addr.s_addr;
else {
for (cmptr = CMSG_FIRSTHDR(&msg); cmptr != NULL;
cmptr = CMSG_NXTHDR(&msg, cmptr))
if (cmptr->cmsg_level == IPPROTO_IP &&
cmptr->cmsg_type == IP_RECVIF) {
sdl = (struct sockaddr_dl *) CMSG_DATA(cmptr);
break;
}
if (get_local_addr(sdl, &local_addr) != 0)
local_addr.s_addr = my_ldp_addr.s_addr;
}
debugp("Read %d bytes from address %s Length: %.4d Version: %d\n",
c, inet_ntoa(rpdu.ldp_id), rpdu.length, rpdu.version);
/* Fill the TLV messages */
t = get_hello_tlv(recvspace + i, c - i);
run_ldp_hello(&rpdu, t, &sender.sa, &local_addr, sock, may_connect);
}
void
send_hello_alarm(int unused)
{
struct ldp_peer *p, *ptmp;
struct hello_info *hi, *hinext;
time_t t = time(NULL);
int olderrno = errno;
if (may_connect == false)
may_connect = true;
/* Send hellos */
if (!(t % ldp_hello_time))
send_hello();
/* Timeout -- */
SLIST_FOREACH(p, &ldp_peer_head, peers)
p->timeout--;
/* Check for timeout */
SLIST_FOREACH_SAFE(p, &ldp_peer_head, peers, ptmp)
if (p->timeout < 1)
switch (p->state) {
case LDP_PEER_HOLDDOWN:
debugp("LDP holddown expired for peer %s\n",
inet_ntoa(p->ldp_id));
ldp_peer_delete(p);
break;
case LDP_PEER_ESTABLISHED:
case LDP_PEER_CONNECTED:
send_notification(p, 0,
NOTIF_FATAL|NOTIF_KEEP_ALIVE_TIMER_EXPIRED);
warnp("Keepalive expired for %s\n",
inet_ntoa(p->ldp_id));
ldp_peer_holddown(p);
break;
} /* switch */
/* send keepalives */
if (!(t % ldp_keepalive_time)) {
SLIST_FOREACH(p, &ldp_peer_head, peers)
if (p->state == LDP_PEER_ESTABLISHED) {
debugp("Sending KeepAlive to %s\n",
inet_ntoa(p->ldp_id));
keep_alive(p);
}
}
/* Decrement and Check hello keepalives */
SLIST_FOREACH_SAFE(hi, &hello_info_head, infos, hinext) {
if (hi->keepalive != 0xFFFF)
hi->keepalive--;
if (hi->keepalive < 1)
SLIST_REMOVE(&hello_info_head, hi, hello_info, infos);
}
/* Set the alarm again and bail out */
alarm(1);
errno = olderrno;
}
static void
bail_out(int x)
{
ldp_peer_holddown_all();
flush_mpls_routes();
exit(0);
}
static void
print_info(int x)
{
printf("Info for %s\n-------\n", LDP_ID);
printf("Neighbours:\n");
show_neighbours(1, NULL);
printf("Bindings:\n");
show_bindings(1, NULL);
printf("Labels:\n");
show_labels(1, NULL);
printf("--------\n");
}
/*
* The big poll that catches every single event
* on every socket.
*/
int
the_big_loop(void)
{
int sock_error;
uint32_t i;
socklen_t sock_error_size = sizeof(int);
struct ldp_peer *p;
struct com_sock *cs;
struct pollfd pfd[MAX_POLL_FDS];
struct hello_socket *hs;
nfds_t pollsum;
#ifdef RO_MSGFILTER
unsigned char msgfilter[] = {
RTM_NEWADDR, RTM_DELADDR,
RTM_ADD, RTM_DELETE, RTM_CHANGE,
};
#endif
assert(MAX_POLL_FDS > 5);
SLIST_INIT(&hello_info_head);
signal(SIGALRM, send_hello_alarm);
signal(SIGPIPE, SIG_IGN);
signal(SIGINT, bail_out);
signal(SIGTERM, bail_out);
signal(SIGINFO, print_info);
/* Send first hellos in 5 seconds. Avoid No hello notifications */
may_connect = false;
alarm(5);
route_socket = socket(PF_ROUTE, SOCK_RAW, AF_UNSPEC);
setsockopt(route_socket, SOL_SOCKET, SO_USELOOPBACK, &(int){0},
sizeof(int));
#ifdef RO_MSGFILTER
setsockopt(route_socket, PF_ROUTE, RO_MSGFILTER, &msgfilter,
sizeof(msgfilter));
#endif
sock_error = bind_current_routes();
if (sock_error != LDP_E_OK) {
fatalp("Cannot get current routes\n");
return sock_error;
}
for (;;) {
pfd[0].fd = ls;
pfd[0].events = POLLRDNORM;
pfd[0].revents = 0;
pfd[1].fd = route_socket;
pfd[1].events = POLLRDNORM;
pfd[1].revents = 0;
pfd[2].fd = command_socket;
pfd[2].events = POLLRDNORM;
pfd[2].revents = 0;
/* Hello sockets */
pollsum = 3;
SLIST_FOREACH(hs, &hello_socket_head, listentry) {
pfd[pollsum].fd = hs->socket;
pfd[pollsum].events = POLLIN;
pfd[pollsum].revents = 0;
pollsum++;
}
/* Command sockets */
for (i=0; i < MAX_COMMAND_SOCKETS; i++)
if (csockets[i].socket != -1) {
if (pollsum >= MAX_POLL_FDS)
break;
pfd[pollsum].fd = csockets[i].socket;
pfd[pollsum].events = POLLIN;
pfd[pollsum].revents = 0;
pollsum++;
}
/* LDP Peer sockets */
SLIST_FOREACH(p, &ldp_peer_head, peers) {
if (p->socket < 1)
continue;
switch (p->state) {
case LDP_PEER_CONNECTED:
case LDP_PEER_ESTABLISHED:
if (pollsum >= MAX_POLL_FDS)
break;
pfd[pollsum].fd = p->socket;
pfd[pollsum].events = POLLRDNORM;
pfd[pollsum].revents = 0;
pollsum++;
break;
case LDP_PEER_CONNECTING:
if (pollsum >= MAX_POLL_FDS)
break;
pfd[pollsum].fd = p->socket;
pfd[pollsum].events = POLLWRNORM;
pfd[pollsum].revents = 0;
pollsum++;
break;
}
}
if (pollsum >= MAX_POLL_FDS) {
fatalp("Too many sockets. Increase MAX_POLL_FDS\n");
return LDP_E_TOO_MANY_FDS;
}
if (poll(pfd, pollsum, INFTIM) < 0) {
if (errno != EINTR)
fatalp("poll: %s", strerror(errno));
continue;
}
for (i = 0; i < pollsum; i++) {
if ((pfd[i].revents & POLLRDNORM) ||
(pfd[i].revents & POLLIN)) {
if(pfd[i].fd == ls)
new_peer_connection();
else if (pfd[i].fd == route_socket) {
struct rt_msg xbuf;
int l, rtmlen = sizeof(xbuf);
/* Read at least rtm_msglen */
l = recv(route_socket, &xbuf,
sizeof(u_short), MSG_PEEK);
if (l == sizeof(u_short))
rtmlen = xbuf.m_rtm.rtm_msglen;
do {
l = recv(route_socket, &xbuf,
rtmlen, MSG_WAITALL);
} while ((l == -1) && (errno == EINTR));
if (l == -1)
break;
check_route(&xbuf, l);
} else if (is_hello_socket(pfd[i].fd) == 1) {
/* Receiving hello socket */
recv_pdu(pfd[i].fd);
} else if (pfd[i].fd == command_socket) {
command_accept(command_socket);
} else if ((cs = is_command_socket(pfd[i].fd))
!= NULL) {
command_dispatch(cs);
} else {
/* ldp peer socket */
p = get_ldp_peer_by_socket(pfd[i].fd);
if (p)
recv_session_pdu(p);
}
} else if(pfd[i].revents & POLLWRNORM) {
p = get_ldp_peer_by_socket(pfd[i].fd);
if (!p)
continue;
assert(p->state == LDP_PEER_CONNECTING);
if (getsockopt(pfd[i].fd, SOL_SOCKET, SO_ERROR,
&sock_error, &sock_error_size) != 0 ||
sock_error != 0) {
ldp_peer_holddown(p);
sock_error = 0;
} else {
p->state = LDP_PEER_CONNECTED;
send_initialize(p);
}
}
}
for (int ri = 0; ri < replay_index; ri++) {
debugp("Replaying: PID %d, SEQ %d\n",
replay_rt[ri].m_rtm.rtm_pid,
replay_rt[ri].m_rtm.rtm_seq);
check_route(&replay_rt[ri], sizeof(struct rt_msg));
}
replay_index = 0;
} /* for (;;) */
}
void
new_peer_connection()
{
union sockunion peer_address, my_address;
struct in_addr *peer_ldp_id = NULL;
struct hello_info *hi;
int s;
s = accept(ls, &peer_address.sa,
& (socklen_t) { sizeof(union sockunion) } );
if (s < 0) {
fatalp("accept: %s", strerror(errno));
return;
}
if (getsockname(s, &my_address.sa,
& (socklen_t) { sizeof(union sockunion) } )) {
fatalp("new_peer_connection(): cannot getsockname\n");
close(s);
return;
}
if (peer_address.sa.sa_family == AF_INET)
peer_address.sin.sin_port = 0;
else if (peer_address.sa.sa_family == AF_INET6)
peer_address.sin6.sin6_port = 0;
else {
fatalp("Unknown peer address family\n");
close(s);
return;
}
/* Already peered or in holddown ? */
if (get_ldp_peer(&peer_address.sa) != NULL) {
close(s);
return;
}
warnp("Accepted a connection from %s\n", satos(&peer_address.sa));
/* Verify if it should connect - XXX: no check for INET6 */
if (peer_address.sa.sa_family == AF_INET &&
ntohl(peer_address.sin.sin_addr.s_addr) <
ntohl(my_address.sin.sin_addr.s_addr)) {
fatalp("Peer %s: connect from lower ID\n",
satos(&peer_address.sa));
close(s);
return;
}
/* Match hello info in order to get ldp_id */
SLIST_FOREACH(hi, &hello_info_head, infos) {
if (sockaddr_cmp(&peer_address.sa,
&hi->transport_address.sa) == 0) {
peer_ldp_id = &hi->ldp_id;
break;
}
}
if (peer_ldp_id == NULL) {
warnp("Got connection from %s, but no hello info exists\n",
satos(&peer_address.sa));
close(s);
return;
} else
ldp_peer_new(peer_ldp_id, &peer_address.sa, NULL,
ldp_holddown_time, s);
}
void
send_initialize(const struct ldp_peer * p)
{
struct init_tlv ti;
ti.type = htons(LDP_INITIALIZE);
ti.length = htons(sizeof(struct init_tlv) - TLV_TYPE_LENGTH);
ti.messageid = htonl(get_message_id());
ti.cs_type = htons(TLV_COMMON_SESSION);
ti.cs_len = htons(CS_LEN);
ti.cs_version = htons(LDP_VERSION);
ti.cs_keepalive = htons(2 * ldp_keepalive_time);
ti.cs_adpvlim = 0;
ti.cs_maxpdulen = htons(MAX_PDU_SIZE);
ti.cs_peeraddress.s_addr = p->ldp_id.s_addr;
ti.cs_peeraddrspace = 0;
send_tlv(p, (struct tlv *) (void *) &ti);
}
void
keep_alive(const struct ldp_peer * p)
{
struct ka_tlv kt;
kt.type = htons(LDP_KEEPALIVE);
kt.length = htons(sizeof(kt.messageid));
kt.messageid = htonl(get_message_id());
send_tlv(p, (struct tlv *) (void *) &kt);
}
/*
* Process a message received from a peer
*/
void
recv_session_pdu(struct ldp_peer * p)
{
struct ldp_pdu *rpdu;
struct address_tlv *atlv;
struct al_tlv *altlv;
struct init_tlv *itlv;
struct label_map_tlv *lmtlv;
struct fec_tlv *fectlv;
struct label_tlv *labeltlv;
struct notification_tlv *nottlv;
struct hello_info *hi;
int c;
int32_t wo = 0;
struct tlv *ttmp;
unsigned char recvspace[MAX_PDU_SIZE];
memset(recvspace, 0, MAX_PDU_SIZE);
do {
c = recv(p->socket, (void *) recvspace, MAX_PDU_SIZE, MSG_PEEK);
} while (c == -1 && errno == EINTR);
debugp("Ready to read %d bytes\n", c);
if (c < 1) { /* Session closed */
warnp("Error in connection with %s\n", inet_ntoa(p->ldp_id));
ldp_peer_holddown(p);
return;
}
if (c > MAX_PDU_SIZE) {
debugp("Incoming PDU size exceeds MAX_PDU_SIZE !\n");
return;
}
if (c < MIN_PDU_SIZE) {
debugp("PDU too small received from peer %s\n",
inet_ntoa(p->ldp_id));
return;
}
rpdu = (struct ldp_pdu *) recvspace;
do {
c = recv(p->socket, (void *) recvspace,
ntohs(rpdu->length) + PDU_VER_LENGTH, MSG_WAITALL);
} while (c == -1 && errno == EINTR);
/* sanity check */
if (check_recv_pdu(p, rpdu, c) != 0)
return;
debugp("Read %d bytes, PDU size: %d bytes\n", c, ntohs(rpdu->length));
wo = sizeof(struct ldp_pdu);
while (wo + TLV_TYPE_LENGTH < (uint)c) {
ttmp = (struct tlv *) (&recvspace[wo]);
if ((ntohs(ttmp->type) != LDP_KEEPALIVE) &&
(ntohs(ttmp->type) != LDP_LABEL_MAPPING)) {
debugp("Got Type: 0x%.4X (Length: %d) from %s\n",
ntohs(ttmp->type), ntohs(ttmp->length),
inet_ntoa(p->ldp_id));
} else
debugp("Got Type: 0x%.4X (Length: %d) from %s\n",
ntohs(ttmp->type), ntohs(ttmp->length),
inet_ntoa(p->ldp_id));
/* Should we get the message ? */
if (p->state != LDP_PEER_ESTABLISHED &&
ntohs(ttmp->type) != LDP_INITIALIZE &&
ntohs(ttmp->type) != LDP_KEEPALIVE &&
ntohs(ttmp->type) != LDP_NOTIFICATION)
break;
/* The big switch */
switch (ntohs(ttmp->type)) {
case LDP_INITIALIZE:
itlv = (struct init_tlv *)ttmp;
/* Check size */
if (ntohs(itlv->length) <
sizeof(struct init_tlv) - TLV_TYPE_LENGTH) {
debugp("Bad size\n");
send_notification(p, 0,
NOTIF_BAD_PDU_LEN | NOTIF_FATAL);
ldp_peer_holddown(p);
break;
}
/* Check version */
if (ntohs(itlv->cs_version) != LDP_VERSION) {
debugp("Bad version");
send_notification(p, ntohl(itlv->messageid),
NOTIF_BAD_LDP_VER | NOTIF_FATAL);
ldp_peer_holddown(p);
break;
}
/* Check if we got any hello from this one */
SLIST_FOREACH(hi, &hello_info_head, infos)
if (hi->ldp_id.s_addr == rpdu->ldp_id.s_addr)
break;
if (hi == NULL) {
debugp("No hello. Moving peer to holddown\n");
send_notification(p, ntohl(itlv->messageid),
NOTIF_SESSION_REJECTED_NO_HELLO | NOTIF_FATAL);
ldp_peer_holddown(p);
break;
}
if (!p->master) {
send_initialize(p);
keep_alive(p);
} else {
p->state = LDP_PEER_ESTABLISHED;
p->established_t = time(NULL);
keep_alive(p);
/*
* Recheck here ldp id because we accepted
* connection without knowing who is it for sure
*/
p->ldp_id.s_addr = rpdu->ldp_id.s_addr;
fatalp("LDP neighbour %s is UP\n",
inet_ntoa(p->ldp_id));
mpls_add_ldp_peer(p);
send_addresses(p);
send_all_bindings(p);
}
break;
case LDP_KEEPALIVE:
if ((p->state == LDP_PEER_CONNECTED) && (!p->master)) {
p->state = LDP_PEER_ESTABLISHED;
p->established_t = time(NULL);
fatalp("LDP neighbour %s is UP\n",
inet_ntoa(p->ldp_id));
mpls_add_ldp_peer(p);
send_addresses(p);
send_all_bindings(p);
}
p->timeout = p->holdtime;
break;
case LDP_ADDRESS:
/* Add peer addresses */
atlv = (struct address_tlv *) ttmp;
altlv = (struct al_tlv *) (&atlv[1]);
add_ifaddresses(p, altlv);
/*
* try to see if we have labels with null peer that
* would match the new peer
*/
label_check_assoc(p);
print_bounded_addresses(p);
break;
case LDP_ADDRESS_WITHDRAW:
atlv = (struct address_tlv *) ttmp;
altlv = (struct al_tlv *) (&atlv[1]);
del_ifaddresses(p, altlv);
break;
case LDP_LABEL_MAPPING:
lmtlv = (struct label_map_tlv *) ttmp;
fectlv = (struct fec_tlv *) (&lmtlv[1]);
labeltlv = (struct label_tlv *)((unsigned char *)fectlv
+ ntohs(fectlv->length) + TLV_TYPE_LENGTH);
map_label(p, fectlv, labeltlv);
break;
case LDP_LABEL_REQUEST:
lmtlv = (struct label_map_tlv *) ttmp;
fectlv = (struct fec_tlv *) (&lmtlv[1]);
switch (request_respond(p, lmtlv, fectlv)) {
case LDP_E_BAD_FEC:
send_notification(p, ntohl(lmtlv->messageid),
NOTIF_UNKNOWN_TLV);
break;
case LDP_E_BAD_AF:
send_notification(p, ntohl(lmtlv->messageid),
NOTIF_UNSUPPORTED_AF);
break;
case LDP_E_NO_SUCH_ROUTE:
send_notification(p, ntohl(lmtlv->messageid),
NOTIF_NO_ROUTE);
break;
}
break;
case LDP_LABEL_WITHDRAW:
lmtlv = (struct label_map_tlv *) ttmp;
fectlv = (struct fec_tlv *) (&lmtlv[1]);
if (withdraw_label(p, fectlv) == LDP_E_OK) {
/* Send RELEASE */
prepare_release(ttmp);
send_tlv(p, ttmp);
}
break;
case LDP_LABEL_RELEASE:
/*
* XXX: we need to make a timed queue...
* For now I just assume peers are processing messages
* correctly so I just ignore confirmations
*/
wo = -1; /* Ignore rest of message */
break;
case LDP_LABEL_ABORT:
/* XXX: For now I pretend I can process everything
* RFC 5036, Section 3.5.9.1
* If an LSR receives a Label Abort Request Message after it
* has responded to the Label Request in question with a Label
* Mapping message or a Notification message, it ignores the
* abort request.
*/
wo = -1;
break;
case LDP_NOTIFICATION:
nottlv = (struct notification_tlv *) ttmp;
nottlv->st_code = ntohl(nottlv->st_code);
fatalp("Got notification 0x%X from peer %s\n",
nottlv->st_code, inet_ntoa(p->ldp_id));
if (nottlv->st_code >> 31) {
fatalp("LDP peer %s signalized %s\n",
inet_ntoa(p->ldp_id),
NOTIF_STR[(nottlv->st_code << 1) >> 1]);
ldp_peer_holddown(p);
wo = -1;
}
break;
case LDP_HELLO:
/* No hellos should came on tcp session */
wo = -1;
break;
default:
warnp("Unknown TLV received from %s\n",
inet_ntoa(p->ldp_id));
debug_tlv(ttmp);
wo = -1;/* discard the rest of the message */
break;
}
if (wo < 0) {
debugp("Discarding the rest of the message\n");
break;
} else {
wo += ntohs(ttmp->length) + TLV_TYPE_LENGTH;
debugp("WORKED ON %u bytes (Left %d)\n", wo, c - wo);
}
} /* while */
}
/* Sends a pdu, tlv pair to a connected peer */
int
send_message(const struct ldp_peer * p, const struct ldp_pdu * pdu,
const struct tlv * t)
{
unsigned char sendspace[MAX_PDU_SIZE];
/* Check if peer is connected */
switch (p->state) {
case LDP_PEER_CONNECTED:
case LDP_PEER_ESTABLISHED:
break;
default:
return -1;
}
/* Check length validity first */
if (ntohs(pdu->length) !=
ntohs(t->length) + TLV_TYPE_LENGTH + PDU_PAYLOAD_LENGTH) {
fatalp("LDP: TLV - PDU incompability. Message discarded\n");
fatalp("LDP: TLV len %d - PDU len %d\n", ntohs(t->length),
ntohs(pdu->length));
return -1;
}
if (ntohs(t->length) + PDU_VER_LENGTH > MAX_PDU_SIZE) {
fatalp("Message to large discarded\n");
return -1;
}
/* Arrange them in a buffer and send */
memcpy(sendspace, pdu, sizeof(struct ldp_pdu));
memcpy(sendspace + sizeof(struct ldp_pdu), t,
ntohs(t->length) + TLV_TYPE_LENGTH);
/* Report keepalives only for DEBUG */
if ((ntohs(t->type) != 0x201) && (ntohs(t->type) != 0x400)) {
debugp("Sending message type 0x%.4X to %s (size: %d)\n",
ntohs(t->type), inet_ntoa(p->ldp_id), ntohs(t->length));
} else
/* downgraded from warnp to debugp for now */
debugp("Sending message type 0x%.4X to %s (size: %d)\n",
ntohs(t->type), inet_ntoa(p->ldp_id), ntohs(t->length));
/* Send it finally */
return send(p->socket, sendspace,
ntohs(pdu->length) + PDU_VER_LENGTH, 0);
}
/*
* Encapsulates TLV into a PDU and sends it to a peer
*/
int
send_tlv(const struct ldp_peer * p, const struct tlv * t)
{
struct in_addr ldp_id;
struct ldp_pdu pdu;
inet_aton(LDP_ID, &ldp_id);
pdu.version = htons(LDP_VERSION);
pdu.ldp_id = ldp_id;
pdu.label_space = 0;
pdu.length = htons(ntohs(t->length) + TLV_TYPE_LENGTH +
PDU_PAYLOAD_LENGTH);
return send_message(p, &pdu, t);
}
int
send_addresses(const struct ldp_peer * p)
{
struct address_list_tlv *t;
int ret;
t = build_address_list_tlv();
ret = send_tlv(p, (struct tlv *) t);
free(t);
return ret;
}
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