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ospf_packet.c
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* OSPF Sending and Receiving OSPF Packets.
* Copyright (C) 1999, 2000 Toshiaki Takada
*/
#include <zebra.h>
#include "monotime.h"
#include "frrevent.h"
#include "memory.h"
#include "linklist.h"
#include "prefix.h"
#include "if.h"
#include "table.h"
#include "sockunion.h"
#include "stream.h"
#include "log.h"
#include "sockopt.h"
#include "checksum.h"
#ifdef CRYPTO_INTERNAL
#include "md5.h"
#endif
#include "vrf.h"
#include "lib_errors.h"
#include "ospfd/ospfd.h"
#include "ospfd/ospf_network.h"
#include "ospfd/ospf_interface.h"
#include "ospfd/ospf_ism.h"
#include "ospfd/ospf_abr.h"
#include "ospfd/ospf_asbr.h"
#include "ospfd/ospf_lsa.h"
#include "ospfd/ospf_lsdb.h"
#include "ospfd/ospf_neighbor.h"
#include "ospfd/ospf_nsm.h"
#include "ospfd/ospf_packet.h"
#include "ospfd/ospf_spf.h"
#include "ospfd/ospf_flood.h"
#include "ospfd/ospf_dump.h"
#include "ospfd/ospf_errors.h"
#include "ospfd/ospf_zebra.h"
#include "ospfd/ospf_gr.h"
/*
* OSPF Fragmentation / fragmented writes
*
* ospfd can support writing fragmented packets, for cases where
* kernel will not fragment IP_HDRINCL and/or multicast destined
* packets (ie TTBOMK all kernels, BSD, SunOS, Linux). However,
* SunOS, probably BSD too, clobber the user supplied IP ID and IP
* flags fields, hence user-space fragmentation will not work.
* Only Linux is known to leave IP header unmolested.
* Further, fragmentation really should be done the kernel, which already
* supports it, and which avoids nasty IP ID state problems.
*
* Fragmentation of OSPF packets can be required on networks with router
* with many many interfaces active in one area, or on networks with links
* with low MTUs.
*/
#ifdef GNU_LINUX
#define WANT_OSPF_WRITE_FRAGMENT
#endif
/* Packet Type String. */
const struct message ospf_packet_type_str[] = {
{OSPF_MSG_HELLO, "Hello"},
{OSPF_MSG_DB_DESC, "Database Description"},
{OSPF_MSG_LS_REQ, "Link State Request"},
{OSPF_MSG_LS_UPD, "Link State Update"},
{OSPF_MSG_LS_ACK, "Link State Acknowledgment"},
{0}};
/* Minimum (besides OSPF_HEADER_SIZE) lengths for OSPF packets of
particular types, offset is the "type" field of a packet. */
static const uint16_t ospf_packet_minlen[] = {
0,
OSPF_HELLO_MIN_SIZE,
OSPF_DB_DESC_MIN_SIZE,
OSPF_LS_REQ_MIN_SIZE,
OSPF_LS_UPD_MIN_SIZE,
OSPF_LS_ACK_MIN_SIZE,
};
/* Minimum (besides OSPF_LSA_HEADER_SIZE) lengths for LSAs of particular
types, offset is the "LSA type" field. */
static const uint16_t ospf_lsa_minlen[] = {
0, /* OSPF_UNKNOWN_LSA */
OSPF_ROUTER_LSA_MIN_SIZE, /* OSPF_ROUTER_LSA */
OSPF_NETWORK_LSA_MIN_SIZE, /* OSPF_NETWORK_LSA */
OSPF_SUMMARY_LSA_MIN_SIZE, /* OSPF_SUMMARY_LSA */
OSPF_SUMMARY_LSA_MIN_SIZE, /* OSPF_ASBR_SUMMARY_LSA */
OSPF_AS_EXTERNAL_LSA_MIN_SIZE, /* OSPF_AS_EXTERNAL_LSA */
0, /* Unsupported, OSPF_GROUP_MEMBER_LSA */
OSPF_AS_EXTERNAL_LSA_MIN_SIZE, /* OSPF_AS_NSSA_LSA */
0, /* Unsupported, OSPF_EXTERNAL_ATTRIBURES_LSA */
OSPF_OPAQUE_LSA_MIN_SIZE, /* OSPF_OPAQUE_LINK_LSA */
OSPF_OPAQUE_LSA_MIN_SIZE, /* OSPF_OPAQUE_AREA_LSA */
OSPF_OPAQUE_LSA_MIN_SIZE, /* OSPF_OPAQUE_AS_LSA */
};
/* for ospf_check_auth() */
static int ospf_check_sum(struct ospf_header *);
/* OSPF authentication checking function */
static int ospf_auth_type(struct ospf_interface *oi)
{
int auth_type;
if (OSPF_IF_PARAM(oi, auth_type) == OSPF_AUTH_NOTSET)
auth_type = oi->area->auth_type;
else
auth_type = OSPF_IF_PARAM(oi, auth_type);
/* Handle case where MD5 key list is not configured aka Cisco */
if (auth_type == OSPF_AUTH_CRYPTOGRAPHIC
&& list_isempty(OSPF_IF_PARAM(oi, auth_crypt)))
return OSPF_AUTH_NULL;
return auth_type;
}
static struct ospf_packet *ospf_packet_new(size_t size)
{
struct ospf_packet *new;
new = XCALLOC(MTYPE_OSPF_PACKET, sizeof(struct ospf_packet));
new->s = stream_new(size);
return new;
}
void ospf_packet_free(struct ospf_packet *op)
{
if (op->s)
stream_free(op->s);
XFREE(MTYPE_OSPF_PACKET, op);
}
struct ospf_fifo *ospf_fifo_new(void)
{
struct ospf_fifo *new;
new = XCALLOC(MTYPE_OSPF_FIFO, sizeof(struct ospf_fifo));
return new;
}
/* Add new packet to fifo. */
void ospf_fifo_push(struct ospf_fifo *fifo, struct ospf_packet *op)
{
if (fifo->tail)
fifo->tail->next = op;
else
fifo->head = op;
fifo->tail = op;
fifo->count++;
}
/* Add new packet to head of fifo. */
static void ospf_fifo_push_head(struct ospf_fifo *fifo, struct ospf_packet *op)
{
op->next = fifo->head;
if (fifo->tail == NULL)
fifo->tail = op;
fifo->head = op;
fifo->count++;
}
/* Delete first packet from fifo. */
struct ospf_packet *ospf_fifo_pop(struct ospf_fifo *fifo)
{
struct ospf_packet *op;
op = fifo->head;
if (op) {
fifo->head = op->next;
if (fifo->head == NULL)
fifo->tail = NULL;
fifo->count--;
}
return op;
}
/* Return first fifo entry. */
struct ospf_packet *ospf_fifo_head(struct ospf_fifo *fifo)
{
return fifo->head;
}
/* Flush ospf packet fifo. */
void ospf_fifo_flush(struct ospf_fifo *fifo)
{
struct ospf_packet *op;
struct ospf_packet *next;
for (op = fifo->head; op; op = next) {
next = op->next;
ospf_packet_free(op);
}
fifo->head = fifo->tail = NULL;
fifo->count = 0;
}
/* Free ospf packet fifo. */
void ospf_fifo_free(struct ospf_fifo *fifo)
{
ospf_fifo_flush(fifo);
XFREE(MTYPE_OSPF_FIFO, fifo);
}
static void ospf_packet_add(struct ospf_interface *oi, struct ospf_packet *op)
{
/* Add packet to end of queue. */
ospf_fifo_push(oi->obuf, op);
/* Debug of packet fifo*/
/* ospf_fifo_debug (oi->obuf); */
}
static void ospf_packet_add_top(struct ospf_interface *oi,
struct ospf_packet *op)
{
/* Add packet to head of queue. */
ospf_fifo_push_head(oi->obuf, op);
/* Debug of packet fifo*/
/* ospf_fifo_debug (oi->obuf); */
}
static void ospf_packet_delete(struct ospf_interface *oi)
{
struct ospf_packet *op;
op = ospf_fifo_pop(oi->obuf);
if (op)
ospf_packet_free(op);
}
static struct ospf_packet *ospf_packet_dup(struct ospf_packet *op)
{
struct ospf_packet *new;
if (stream_get_endp(op->s) != op->length)
/* XXX size_t */
zlog_debug(
"ospf_packet_dup stream %lu ospf_packet %u size mismatch",
(unsigned long)STREAM_SIZE(op->s), op->length);
/* Reserve space for MD5 authentication that may be added later. */
new = ospf_packet_new(stream_get_endp(op->s) + OSPF_AUTH_MD5_SIZE);
stream_copy(new->s, op->s);
new->dst = op->dst;
new->length = op->length;
return new;
}
/* XXX inline */
static unsigned int ospf_packet_authspace(struct ospf_interface *oi)
{
int auth = 0;
if (ospf_auth_type(oi) == OSPF_AUTH_CRYPTOGRAPHIC)
auth = OSPF_AUTH_MD5_SIZE;
return auth;
}
static unsigned int ospf_packet_max(struct ospf_interface *oi)
{
int max;
max = oi->ifp->mtu - ospf_packet_authspace(oi);
max -= (OSPF_HEADER_SIZE + sizeof(struct ip));
return max;
}
static int ospf_check_md5_digest(struct ospf_interface *oi,
struct ospf_header *ospfh)
{
#ifdef CRYPTO_OPENSSL
EVP_MD_CTX *ctx;
#elif CRYPTO_INTERNAL
MD5_CTX ctx;
#endif
unsigned char digest[OSPF_AUTH_MD5_SIZE];
struct crypt_key *ck;
struct ospf_neighbor *nbr;
uint16_t length = ntohs(ospfh->length);
/* Get secret key. */
ck = ospf_crypt_key_lookup(OSPF_IF_PARAM(oi, auth_crypt),
ospfh->u.crypt.key_id);
if (ck == NULL) {
flog_warn(
EC_OSPF_MD5,
"interface %s: ospf_check_md5 no key %d, Router-ID: %pI4",
IF_NAME(oi), ospfh->u.crypt.key_id, &ospfh->router_id);
return 0;
}
/* check crypto seqnum. */
nbr = ospf_nbr_lookup_by_routerid(oi->nbrs, &ospfh->router_id);
if (nbr
&& ntohl(nbr->crypt_seqnum) > ntohl(ospfh->u.crypt.crypt_seqnum)) {
flog_warn(
EC_OSPF_MD5,
"interface %s: ospf_check_md5 bad sequence %d (expect %d), Router-ID: %pI4",
IF_NAME(oi), ntohl(ospfh->u.crypt.crypt_seqnum),
ntohl(nbr->crypt_seqnum), &ospfh->router_id);
return 0;
}
/* Generate a digest for the ospf packet - their digest + our digest. */
#ifdef CRYPTO_OPENSSL
unsigned int md5_size = OSPF_AUTH_MD5_SIZE;
ctx = EVP_MD_CTX_new();
EVP_DigestInit(ctx, EVP_md5());
EVP_DigestUpdate(ctx, ospfh, length);
EVP_DigestUpdate(ctx, ck->auth_key, OSPF_AUTH_MD5_SIZE);
EVP_DigestFinal(ctx, digest, &md5_size);
EVP_MD_CTX_free(ctx);
#elif CRYPTO_INTERNAL
memset(&ctx, 0, sizeof(ctx));
MD5Init(&ctx);
MD5Update(&ctx, ospfh, length);
MD5Update(&ctx, ck->auth_key, OSPF_AUTH_MD5_SIZE);
MD5Final(digest, &ctx);
#endif
/* compare the two */
if (memcmp((caddr_t)ospfh + length, digest, OSPF_AUTH_MD5_SIZE)) {
flog_warn(
EC_OSPF_MD5,
"interface %s: ospf_check_md5 checksum mismatch, Router-ID: %pI4",
IF_NAME(oi), &ospfh->router_id);
return 0;
}
/* save neighbor's crypt_seqnum */
if (nbr)
nbr->crypt_seqnum = ospfh->u.crypt.crypt_seqnum;
return 1;
}
/* This function is called from ospf_write(), it will detect the
authentication scheme and if it is MD5, it will change the sequence
and update the MD5 digest. */
static int ospf_make_md5_digest(struct ospf_interface *oi,
struct ospf_packet *op)
{
struct ospf_header *ospfh;
unsigned char digest[OSPF_AUTH_MD5_SIZE] = {0};
#ifdef CRYPTO_OPENSSL
EVP_MD_CTX *ctx;
#elif CRYPTO_INTERNAL
MD5_CTX ctx;
#endif
void *ibuf;
uint32_t t;
struct crypt_key *ck;
const uint8_t *auth_key;
ibuf = STREAM_DATA(op->s);
ospfh = (struct ospf_header *)ibuf;
if (ntohs(ospfh->auth_type) != OSPF_AUTH_CRYPTOGRAPHIC)
return 0;
/* We do this here so when we dup a packet, we don't have to
waste CPU rewriting other headers.
Note that frr_time /deliberately/ is not used here */
t = (time(NULL) & 0xFFFFFFFF);
if (t > oi->crypt_seqnum)
oi->crypt_seqnum = t;
else
oi->crypt_seqnum++;
ospfh->u.crypt.crypt_seqnum = htonl(oi->crypt_seqnum);
/* Get MD5 Authentication key from auth_key list. */
if (list_isempty(OSPF_IF_PARAM(oi, auth_crypt)))
auth_key = (const uint8_t *)digest;
else {
ck = listgetdata(listtail(OSPF_IF_PARAM(oi, auth_crypt)));
auth_key = ck->auth_key;
}
/* Generate a digest for the entire packet + our secret key. */
#ifdef CRYPTO_OPENSSL
unsigned int md5_size = OSPF_AUTH_MD5_SIZE;
ctx = EVP_MD_CTX_new();
EVP_DigestInit(ctx, EVP_md5());
EVP_DigestUpdate(ctx, ibuf, ntohs(ospfh->length));
EVP_DigestUpdate(ctx, auth_key, OSPF_AUTH_MD5_SIZE);
EVP_DigestFinal(ctx, digest, &md5_size);
EVP_MD_CTX_free(ctx);
#elif CRYPTO_INTERNAL
memset(&ctx, 0, sizeof(ctx));
MD5Init(&ctx);
MD5Update(&ctx, ibuf, ntohs(ospfh->length));
MD5Update(&ctx, auth_key, OSPF_AUTH_MD5_SIZE);
MD5Final(digest, &ctx);
#endif
/* Append md5 digest to the end of the stream. */
stream_put(op->s, digest, OSPF_AUTH_MD5_SIZE);
/* We do *NOT* increment the OSPF header length. */
op->length = ntohs(ospfh->length) + OSPF_AUTH_MD5_SIZE;
if (stream_get_endp(op->s) != op->length)
/* XXX size_t */
flog_warn(
EC_OSPF_MD5,
"%s: length mismatch stream %lu ospf_packet %u, Router-ID %pI4",
__func__, (unsigned long)stream_get_endp(op->s),
op->length, &ospfh->router_id);
return OSPF_AUTH_MD5_SIZE;
}
static void ospf_ls_req_timer(struct event *thread)
{
struct ospf_neighbor *nbr;
nbr = EVENT_ARG(thread);
nbr->t_ls_req = NULL;
/* Send Link State Request. */
if (ospf_ls_request_count(nbr))
ospf_ls_req_send(nbr);
/* Set Link State Request retransmission timer. */
OSPF_NSM_TIMER_ON(nbr->t_ls_req, ospf_ls_req_timer, nbr->v_ls_req);
}
void ospf_ls_req_event(struct ospf_neighbor *nbr)
{
EVENT_OFF(nbr->t_ls_req);
event_add_event(master, ospf_ls_req_timer, nbr, 0, &nbr->t_ls_req);
}
/* Cyclic timer function. Fist registered in ospf_nbr_new () in
ospf_neighbor.c */
void ospf_ls_upd_timer(struct event *thread)
{
struct ospf_neighbor *nbr;
nbr = EVENT_ARG(thread);
nbr->t_ls_upd = NULL;
/* Send Link State Update. */
if (ospf_ls_retransmit_count(nbr) > 0) {
struct list *update;
struct ospf_lsdb *lsdb;
int i;
int retransmit_interval;
retransmit_interval =
OSPF_IF_PARAM(nbr->oi, retransmit_interval);
lsdb = &nbr->ls_rxmt;
update = list_new();
for (i = OSPF_MIN_LSA; i < OSPF_MAX_LSA; i++) {
struct route_table *table = lsdb->type[i].db;
struct route_node *rn;
for (rn = route_top(table); rn; rn = route_next(rn)) {
struct ospf_lsa *lsa;
if ((lsa = rn->info) != NULL) {
/* Don't retransmit an LSA if we
received it within
the last RxmtInterval seconds - this
is to allow the
neighbour a chance to acknowledge the
LSA as it may
have ben just received before the
retransmit timer
fired. This is a small tweak to what
is in the RFC,
but it will cut out out a lot of
retransmit traffic
- MAG */
if (monotime_since(&lsa->tv_recv, NULL)
>= retransmit_interval * 1000000LL)
listnode_add(update, rn->info);
}
}
}
if (listcount(update) > 0)
ospf_ls_upd_send(nbr, update, OSPF_SEND_PACKET_DIRECT,
0);
list_delete(&update);
}
/* Set LS Update retransmission timer. */
OSPF_NSM_TIMER_ON(nbr->t_ls_upd, ospf_ls_upd_timer, nbr->v_ls_upd);
}
void ospf_ls_ack_timer(struct event *thread)
{
struct ospf_interface *oi;
oi = EVENT_ARG(thread);
oi->t_ls_ack = NULL;
/* Send Link State Acknowledgment. */
if (listcount(oi->ls_ack) > 0)
ospf_ls_ack_send_delayed(oi);
/* Set LS Ack timer. */
OSPF_ISM_TIMER_ON(oi->t_ls_ack, ospf_ls_ack_timer, oi->v_ls_ack);
}
#ifdef WANT_OSPF_WRITE_FRAGMENT
static void ospf_write_frags(int fd, struct ospf_packet *op, struct ip *iph,
struct msghdr *msg, unsigned int maxdatasize,
unsigned int mtu, int flags, uint8_t type)
{
#define OSPF_WRITE_FRAG_SHIFT 3
uint16_t offset;
struct iovec *iovp;
int ret;
assert(op->length == stream_get_endp(op->s));
assert(msg->msg_iovlen == 2);
/* we can but try.
*
* SunOS, BSD and BSD derived kernels likely will clear ip_id, as
* well as the IP_MF flag, making this all quite pointless.
*
* However, for a system on which IP_MF is left alone, and ip_id left
* alone or else which sets same ip_id for each fragment this might
* work, eg linux.
*
* XXX-TODO: It would be much nicer to have the kernel's use their
* existing fragmentation support to do this for us. Bugs/RFEs need to
* be raised against the various kernels.
*/
/* set More Frag */
iph->ip_off |= IP_MF;
/* ip frag offset is expressed in units of 8byte words */
offset = maxdatasize >> OSPF_WRITE_FRAG_SHIFT;
iovp = &msg->msg_iov[1];
while ((stream_get_endp(op->s) - stream_get_getp(op->s))
> maxdatasize) {
/* data length of this frag is to next offset value */
iovp->iov_len = offset << OSPF_WRITE_FRAG_SHIFT;
iph->ip_len = iovp->iov_len + sizeof(struct ip);
assert(iph->ip_len <= mtu);
sockopt_iphdrincl_swab_htosys(iph);
ret = sendmsg(fd, msg, flags);
sockopt_iphdrincl_swab_systoh(iph);
if (ret < 0)
flog_err(
EC_LIB_SOCKET,
"*** %s: sendmsg failed to %pI4, id %d, off %d, len %d, mtu %u failed with %s",
__func__, &iph->ip_dst, iph->ip_id, iph->ip_off,
iph->ip_len, mtu, safe_strerror(errno));
if (IS_DEBUG_OSPF_PACKET(type - 1, SEND)) {
zlog_debug("%s: sent id %d, off %d, len %d to %pI4",
__func__, iph->ip_id, iph->ip_off,
iph->ip_len, &iph->ip_dst);
}
iph->ip_off += offset;
stream_forward_getp(op->s, iovp->iov_len);
iovp->iov_base = stream_pnt(op->s);
}
/* setup for final fragment */
iovp->iov_len = stream_get_endp(op->s) - stream_get_getp(op->s);
iph->ip_len = iovp->iov_len + sizeof(struct ip);
iph->ip_off &= (~IP_MF);
}
#endif /* WANT_OSPF_WRITE_FRAGMENT */
static void ospf_write(struct event *thread)
{
struct ospf *ospf = EVENT_ARG(thread);
struct ospf_interface *oi;
struct ospf_packet *op;
struct sockaddr_in sa_dst;
struct ip iph;
struct msghdr msg;
struct iovec iov[2];
uint8_t type;
int ret, fd;
int flags = 0;
struct listnode *node;
#ifdef WANT_OSPF_WRITE_FRAGMENT
static uint16_t ipid = 0;
uint16_t maxdatasize;
#endif /* WANT_OSPF_WRITE_FRAGMENT */
#define OSPF_WRITE_IPHL_SHIFT 2
int pkt_count = 0;
#ifdef GNU_LINUX
unsigned char cmsgbuf[64] = {};
struct cmsghdr *cm = (struct cmsghdr *)cmsgbuf;
struct in_pktinfo *pi;
#endif
fd = ospf->fd;
if (fd < 0 || ospf->oi_running == 0) {
if (IS_DEBUG_OSPF_EVENT)
zlog_debug("%s failed to send, fd %d, instance %u",
__func__, fd, ospf->oi_running);
return;
}
node = listhead(ospf->oi_write_q);
assert(node);
oi = listgetdata(node);
#ifdef WANT_OSPF_WRITE_FRAGMENT
/* seed ipid static with low order bits of time */
if (ipid == 0)
ipid = (time(NULL) & 0xffff);
#endif /* WANT_OSPF_WRITE_FRAGMENT */
while ((pkt_count < ospf->write_oi_count) && oi) {
pkt_count++;
#ifdef WANT_OSPF_WRITE_FRAGMENT
/* convenience - max OSPF data per packet */
maxdatasize = oi->ifp->mtu - sizeof(struct ip);
#endif /* WANT_OSPF_WRITE_FRAGMENT */
/* Reset socket fd to use. */
fd = ospf->fd;
/* Check for per-interface socket */
if (ospf->intf_socket_enabled &&
(IF_OSPF_IF_INFO(oi->ifp))->oii_fd > 0)
fd = (IF_OSPF_IF_INFO(oi->ifp))->oii_fd;
/* Get one packet from queue. */
op = ospf_fifo_head(oi->obuf);
assert(op);
assert(op->length >= OSPF_HEADER_SIZE);
if (op->dst.s_addr == htonl(OSPF_ALLSPFROUTERS)
|| op->dst.s_addr == htonl(OSPF_ALLDROUTERS))
ospf_if_ipmulticast(fd, oi->address, oi->ifp->ifindex);
/* Rewrite the md5 signature & update the seq */
ospf_make_md5_digest(oi, op);
/* Retrieve OSPF packet type. */
stream_set_getp(op->s, 1);
type = stream_getc(op->s);
/* reset get pointer */
stream_set_getp(op->s, 0);
memset(&iph, 0, sizeof(iph));
memset(&sa_dst, 0, sizeof(sa_dst));
sa_dst.sin_family = AF_INET;
#ifdef HAVE_STRUCT_SOCKADDR_IN_SIN_LEN
sa_dst.sin_len = sizeof(sa_dst);
#endif /* HAVE_STRUCT_SOCKADDR_IN_SIN_LEN */
sa_dst.sin_addr = op->dst;
sa_dst.sin_port = htons(0);
/* Set DONTROUTE flag if dst is unicast. */
if (oi->type != OSPF_IFTYPE_VIRTUALLINK)
if (!IN_MULTICAST(htonl(op->dst.s_addr)))
flags = MSG_DONTROUTE;
iph.ip_hl = sizeof(struct ip) >> OSPF_WRITE_IPHL_SHIFT;
/* it'd be very strange for header to not be 4byte-word aligned
* but.. */
if (sizeof(struct ip)
> (unsigned int)(iph.ip_hl << OSPF_WRITE_IPHL_SHIFT))
iph.ip_hl++; /* we presume sizeof(struct ip) cant
overflow ip_hl.. */
iph.ip_v = IPVERSION;
iph.ip_tos = IPTOS_PREC_INTERNETCONTROL;
iph.ip_len = (iph.ip_hl << OSPF_WRITE_IPHL_SHIFT) + op->length;
#if defined(__DragonFly__)
/*
* DragonFly's raw socket expects ip_len/ip_off in network byte
* order.
*/
iph.ip_len = htons(iph.ip_len);
#endif
#ifdef WANT_OSPF_WRITE_FRAGMENT
/* XXX-MT: not thread-safe at all..
* XXX: this presumes this is only programme sending OSPF
* packets
* otherwise, no guarantee ipid will be unique
*/
iph.ip_id = ++ipid;
#endif /* WANT_OSPF_WRITE_FRAGMENT */
iph.ip_off = 0;
if (oi->type == OSPF_IFTYPE_VIRTUALLINK)
iph.ip_ttl = OSPF_VL_IP_TTL;
else
iph.ip_ttl = OSPF_IP_TTL;
iph.ip_p = IPPROTO_OSPFIGP;
iph.ip_sum = 0;
iph.ip_src.s_addr = oi->address->u.prefix4.s_addr;
iph.ip_dst.s_addr = op->dst.s_addr;
memset(&msg, 0, sizeof(msg));
msg.msg_name = (caddr_t)&sa_dst;
msg.msg_namelen = sizeof(sa_dst);
msg.msg_iov = iov;
msg.msg_iovlen = 2;
iov[0].iov_base = (char *)&iph;
iov[0].iov_len = iph.ip_hl << OSPF_WRITE_IPHL_SHIFT;
iov[1].iov_base = stream_pnt(op->s);
iov[1].iov_len = op->length;
#ifdef GNU_LINUX
msg.msg_control = (caddr_t)cm;
cm->cmsg_level = SOL_IP;
cm->cmsg_type = IP_PKTINFO;
cm->cmsg_len = CMSG_LEN(sizeof(struct in_pktinfo));
pi = (struct in_pktinfo *)CMSG_DATA(cm);
pi->ipi_ifindex = oi->ifp->ifindex;
msg.msg_controllen = cm->cmsg_len;
#endif
/* Sadly we can not rely on kernels to fragment packets
* because of either IP_HDRINCL and/or multicast
* destination being set.
*/
#ifdef WANT_OSPF_WRITE_FRAGMENT
if (op->length > maxdatasize)
ospf_write_frags(fd, op, &iph, &msg, maxdatasize,
oi->ifp->mtu, flags, type);
#endif /* WANT_OSPF_WRITE_FRAGMENT */
/* send final fragment (could be first) */
sockopt_iphdrincl_swab_htosys(&iph);
ret = sendmsg(fd, &msg, flags);
sockopt_iphdrincl_swab_systoh(&iph);
if (IS_DEBUG_OSPF_EVENT)
zlog_debug(
"%s to %pI4, id %d, off %d, len %d, interface %s, mtu %u:",
__func__, &iph.ip_dst, iph.ip_id, iph.ip_off,
iph.ip_len, oi->ifp->name, oi->ifp->mtu);
/* sendmsg will return EPERM if firewall is blocking sending.
* This is a normal situation when 'ip nhrp map multicast xxx'
* is being used to send multicast packets to DMVPN peers. In
* that case the original message is blocked with iptables rule
* causing the EPERM result
*/
if (ret < 0 && errno != EPERM)
flog_err(
EC_LIB_SOCKET,
"*** sendmsg in %s failed to %pI4, id %d, off %d, len %d, interface %s, mtu %u: %s",
__func__, &iph.ip_dst, iph.ip_id, iph.ip_off,
iph.ip_len, oi->ifp->name, oi->ifp->mtu,
safe_strerror(errno));
/* Show debug sending packet. */
if (IS_DEBUG_OSPF_PACKET(type - 1, SEND)) {
if (IS_DEBUG_OSPF_PACKET(type - 1, DETAIL)) {
zlog_debug(
"-----------------------------------------------------");
stream_set_getp(op->s, 0);
ospf_packet_dump(op->s);
}
zlog_debug("%s sent to [%pI4] via [%s].",
lookup_msg(ospf_packet_type_str, type, NULL),
&op->dst, IF_NAME(oi));
if (IS_DEBUG_OSPF_PACKET(type - 1, DETAIL))
zlog_debug(
"-----------------------------------------------------");
}
switch (type) {
case OSPF_MSG_HELLO:
oi->hello_out++;
break;
case OSPF_MSG_DB_DESC:
oi->db_desc_out++;
break;
case OSPF_MSG_LS_REQ:
oi->ls_req_out++;
break;
case OSPF_MSG_LS_UPD:
oi->ls_upd_out++;
break;
case OSPF_MSG_LS_ACK:
oi->ls_ack_out++;
break;
default:
break;
}
/* Now delete packet from queue. */
ospf_packet_delete(oi);
/* Move this interface to the tail of write_q to
serve everyone in a round robin fashion */
list_delete_node(ospf->oi_write_q, node);
if (ospf_fifo_head(oi->obuf) == NULL) {
oi->on_write_q = 0;
oi = NULL;
} else
listnode_add(ospf->oi_write_q, oi);
/* Setup to service from the head of the queue again */
if (!list_isempty(ospf->oi_write_q)) {
node = listhead(ospf->oi_write_q);
oi = listgetdata(node);
}
}
/* If packets still remain in queue, call write thread. */
if (!list_isempty(ospf->oi_write_q))
event_add_write(master, ospf_write, ospf, ospf->fd,
&ospf->t_write);
}
/* OSPF Hello message read -- RFC2328 Section 10.5. */
static void ospf_hello(struct ip *iph, struct ospf_header *ospfh,
struct stream *s, struct ospf_interface *oi, int size)
{
struct ospf_hello *hello;
struct ospf_neighbor *nbr;
int old_state;
struct prefix p;
/* increment statistics. */
oi->hello_in++;
hello = (struct ospf_hello *)stream_pnt(s);
/* If Hello is myself, silently discard. */
if (IPV4_ADDR_SAME(&ospfh->router_id, &oi->ospf->router_id)) {
if (IS_DEBUG_OSPF_PACKET(ospfh->type - 1, RECV)) {
zlog_debug(
"ospf_header[%s/%pI4]: selforiginated, dropping.",
lookup_msg(ospf_packet_type_str, ospfh->type,
NULL),
&iph->ip_src);
}
return;
}
/* get neighbor prefix. */
p.family = AF_INET;
p.prefixlen = ip_masklen(hello->network_mask);
p.u.prefix4 = iph->ip_src;
/* Compare network mask. */
/* Checking is ignored for Point-to-Point and Virtual link. */
/* Checking is also ignored for Point-to-Multipoint with /32 prefix */
if (oi->type != OSPF_IFTYPE_POINTOPOINT
&& oi->type != OSPF_IFTYPE_VIRTUALLINK
&& !(oi->type == OSPF_IFTYPE_POINTOMULTIPOINT
&& oi->address->prefixlen == IPV4_MAX_BITLEN))
if (oi->address->prefixlen != p.prefixlen) {
flog_warn(
EC_OSPF_PACKET,
"Packet %pI4 [Hello:RECV]: NetworkMask mismatch on %s (configured prefix length is %d, but hello packet indicates %d).",
&ospfh->router_id, IF_NAME(oi),
(int)oi->address->prefixlen, (int)p.prefixlen);
return;
}
/* Compare Router Dead Interval. */
if (OSPF_IF_PARAM(oi, v_wait) != ntohl(hello->dead_interval)) {
flog_warn(
EC_OSPF_PACKET,
"Packet %pI4 [Hello:RECV]: RouterDeadInterval mismatch on %s (expected %u, but received %u).",
&ospfh->router_id, IF_NAME(oi),
OSPF_IF_PARAM(oi, v_wait), ntohl(hello->dead_interval));
return;
}
/* Compare Hello Interval - ignored if fast-hellos are set. */
if (OSPF_IF_PARAM(oi, fast_hello) == 0) {
if (OSPF_IF_PARAM(oi, v_hello)
!= ntohs(hello->hello_interval)) {
flog_warn(
EC_OSPF_PACKET,
"Packet %pI4 [Hello:RECV]: HelloInterval mismatch on %s (expected %u, but received %u).",
&ospfh->router_id, IF_NAME(oi),
OSPF_IF_PARAM(oi, v_hello),
ntohs(hello->hello_interval));
return;
}
}
if (IS_DEBUG_OSPF_EVENT)
zlog_debug("Packet %pI4 [Hello:RECV]: Options on %s %s vrf %s",
&ospfh->router_id, IF_NAME(oi),
ospf_options_dump(hello->options),
ospf_vrf_id_to_name(oi->ospf->vrf_id));
/* Compare options. */
#define REJECT_IF_TBIT_ON 1 /* XXX */
#ifdef REJECT_IF_TBIT_ON
if (CHECK_FLAG(hello->options, OSPF_OPTION_MT)) {
/*
* This router does not support non-zero TOS.
* Drop this Hello packet not to establish neighbor
* relationship.
*/
flog_warn(EC_OSPF_PACKET,
"Packet %pI4 [Hello:RECV]: T-bit ON on %s, drop it.",
&ospfh->router_id, IF_NAME(oi));
return;
}
#endif /* REJECT_IF_TBIT_ON */
if (CHECK_FLAG(oi->ospf->config, OSPF_OPAQUE_CAPABLE) &&
OSPF_IF_PARAM(oi, opaque_capable) &&
CHECK_FLAG(hello->options, OSPF_OPTION_O)) {
/*
* This router does know the correct usage of O-bit
* the bit should be set in DD packet only.
*/
flog_warn(EC_OSPF_PACKET,
"Packet %pI4 [Hello:RECV]: O-bit abuse? on %s",
&ospfh->router_id, IF_NAME(oi));
#ifdef STRICT_OBIT_USAGE_CHECK
return; /* Reject this packet. */
#else /* STRICT_OBIT_USAGE_CHECK */
UNSET_FLAG(hello->options, OSPF_OPTION_O); /* Ignore O-bit. */
#endif /* STRICT_OBIT_USAGE_CHECK */
}
/* new for NSSA is to ensure that NP is on and E is off */
if (oi->area->external_routing == OSPF_AREA_NSSA) {
if (!(CHECK_FLAG(OPTIONS(oi), OSPF_OPTION_NP)
&& CHECK_FLAG(hello->options, OSPF_OPTION_NP)
&& !CHECK_FLAG(OPTIONS(oi), OSPF_OPTION_E)
&& !CHECK_FLAG(hello->options, OSPF_OPTION_E))) {
flog_warn(
EC_OSPF_PACKET,
"NSSA-Packet-%pI4[Hello:RECV]: my options: %x, his options %x",
&ospfh->router_id, OPTIONS(oi),
hello->options);
return;
}
if (IS_DEBUG_OSPF_NSSA)
zlog_debug("NSSA-Hello:RECV:Packet from %pI4:",
&ospfh->router_id);
} else
/* The setting of the E-bit found in the Hello Packet's Options
field must match this area's ExternalRoutingCapability A
mismatch causes processing to stop and the packet to be
dropped. The setting of the rest of the bits in the Hello
Packet's Options field should be ignored. */
if (CHECK_FLAG(OPTIONS(oi), OSPF_OPTION_E)
!= CHECK_FLAG(hello->options, OSPF_OPTION_E)) {
flog_warn(
EC_OSPF_PACKET,
"Packet %pI4 [Hello:RECV]: my options: %x, his options %x",