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ripd.c
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ripd.c
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/* RIP version 1 and 2.
* Copyright (C) 2005 6WIND <alain.ritoux@6wind.com>
* Copyright (C) 1997, 98, 99 Kunihiro Ishiguro <kunihiro@zebra.org>
*
* This file is part of GNU Zebra.
*
* GNU Zebra is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2, or (at your option) any
* later version.
*
* GNU Zebra is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; see the file COPYING; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <zebra.h>
#include "vrf.h"
#include "if.h"
#include "command.h"
#include "prefix.h"
#include "table.h"
#include "thread.h"
#include "memory.h"
#include "log.h"
#include "stream.h"
#include "filter.h"
#include "sockunion.h"
#include "sockopt.h"
#include "routemap.h"
#include "if_rmap.h"
#include "plist.h"
#include "distribute.h"
#include "md5.h"
#include "keychain.h"
#include "privs.h"
#include "lib_errors.h"
#include "ripd/ripd.h"
#include "ripd/rip_debug.h"
#include "ripd/rip_errors.h"
DEFINE_QOBJ_TYPE(rip)
/* UDP receive buffer size */
#define RIP_UDP_RCV_BUF 41600
/* RIP Structure. */
struct rip *rip = NULL;
/* RIP neighbor address table. */
struct route_table *rip_neighbor_table;
/* RIP route changes. */
long rip_global_route_changes = 0;
/* RIP queries. */
long rip_global_queries = 0;
/* Prototypes. */
static void rip_event(enum rip_event, int);
static void rip_output_process(struct connected *, struct sockaddr_in *, int,
uint8_t);
static int rip_triggered_update(struct thread *);
static int rip_update_jitter(unsigned long);
/* RIP output routes type. */
enum { rip_all_route, rip_changed_route };
/* RIP command strings. */
static const struct message rip_msg[] = {{RIP_REQUEST, "REQUEST"},
{RIP_RESPONSE, "RESPONSE"},
{RIP_TRACEON, "TRACEON"},
{RIP_TRACEOFF, "TRACEOFF"},
{RIP_POLL, "POLL"},
{RIP_POLL_ENTRY, "POLL ENTRY"},
{0}};
/* Utility function to set boradcast option to the socket. */
static int sockopt_broadcast(int sock)
{
int ret;
int on = 1;
ret = setsockopt(sock, SOL_SOCKET, SO_BROADCAST, (char *)&on,
sizeof on);
if (ret < 0) {
zlog_warn("can't set sockopt SO_BROADCAST to socket %d", sock);
return -1;
}
return 0;
}
static int rip_route_rte(struct rip_info *rinfo)
{
return (rinfo->type == ZEBRA_ROUTE_RIP
&& rinfo->sub_type == RIP_ROUTE_RTE);
}
static struct rip_info *rip_info_new(void)
{
return XCALLOC(MTYPE_RIP_INFO, sizeof(struct rip_info));
}
void rip_info_free(struct rip_info *rinfo)
{
XFREE(MTYPE_RIP_INFO, rinfo);
}
/* RIP route garbage collect timer. */
static int rip_garbage_collect(struct thread *t)
{
struct rip_info *rinfo;
struct route_node *rp;
rinfo = THREAD_ARG(t);
rinfo->t_garbage_collect = NULL;
/* Off timeout timer. */
RIP_TIMER_OFF(rinfo->t_timeout);
/* Get route_node pointer. */
rp = rinfo->rp;
/* Unlock route_node. */
listnode_delete(rp->info, rinfo);
if (list_isempty((struct list *)rp->info)) {
list_delete_and_null((struct list **)&rp->info);
route_unlock_node(rp);
}
/* Free RIP routing information. */
rip_info_free(rinfo);
return 0;
}
static void rip_timeout_update(struct rip_info *rinfo);
/* Add new route to the ECMP list.
* RETURN: the new entry added in the list, or NULL if it is not the first
* entry and ECMP is not allowed.
*/
struct rip_info *rip_ecmp_add(struct rip_info *rinfo_new)
{
struct route_node *rp = rinfo_new->rp;
struct rip_info *rinfo = NULL;
struct list *list = NULL;
if (rp->info == NULL)
rp->info = list_new();
list = (struct list *)rp->info;
/* If ECMP is not allowed and some entry already exists in the list,
* do nothing. */
if (listcount(list) && !rip->ecmp)
return NULL;
rinfo = rip_info_new();
memcpy(rinfo, rinfo_new, sizeof(struct rip_info));
listnode_add(list, rinfo);
if (rip_route_rte(rinfo)) {
rip_timeout_update(rinfo);
rip_zebra_ipv4_add(rp);
}
/* Set the route change flag on the first entry. */
rinfo = listgetdata(listhead(list));
SET_FLAG(rinfo->flags, RIP_RTF_CHANGED);
/* Signal the output process to trigger an update (see section 2.5). */
rip_event(RIP_TRIGGERED_UPDATE, 0);
return rinfo;
}
/* Replace the ECMP list with the new route.
* RETURN: the new entry added in the list
*/
struct rip_info *rip_ecmp_replace(struct rip_info *rinfo_new)
{
struct route_node *rp = rinfo_new->rp;
struct list *list = (struct list *)rp->info;
struct rip_info *rinfo = NULL, *tmp_rinfo = NULL;
struct listnode *node = NULL, *nextnode = NULL;
if (list == NULL || listcount(list) == 0)
return rip_ecmp_add(rinfo_new);
/* Get the first entry */
rinfo = listgetdata(listhead(list));
/* Learnt route replaced by a local one. Delete it from zebra. */
if (rip_route_rte(rinfo) && !rip_route_rte(rinfo_new))
if (CHECK_FLAG(rinfo->flags, RIP_RTF_FIB))
rip_zebra_ipv4_delete(rp);
/* Re-use the first entry, and delete the others. */
for (ALL_LIST_ELEMENTS(list, node, nextnode, tmp_rinfo))
if (tmp_rinfo != rinfo) {
RIP_TIMER_OFF(tmp_rinfo->t_timeout);
RIP_TIMER_OFF(tmp_rinfo->t_garbage_collect);
list_delete_node(list, node);
rip_info_free(tmp_rinfo);
}
RIP_TIMER_OFF(rinfo->t_timeout);
RIP_TIMER_OFF(rinfo->t_garbage_collect);
memcpy(rinfo, rinfo_new, sizeof(struct rip_info));
if (rip_route_rte(rinfo)) {
rip_timeout_update(rinfo);
/* The ADD message implies an update. */
rip_zebra_ipv4_add(rp);
}
/* Set the route change flag. */
SET_FLAG(rinfo->flags, RIP_RTF_CHANGED);
/* Signal the output process to trigger an update (see section 2.5). */
rip_event(RIP_TRIGGERED_UPDATE, 0);
return rinfo;
}
/* Delete one route from the ECMP list.
* RETURN:
* null - the entry is freed, and other entries exist in the list
* the entry - the entry is the last one in the list; its metric is set
* to INFINITY, and the garbage collector is started for it
*/
struct rip_info *rip_ecmp_delete(struct rip_info *rinfo)
{
struct route_node *rp = rinfo->rp;
struct list *list = (struct list *)rp->info;
RIP_TIMER_OFF(rinfo->t_timeout);
if (listcount(list) > 1) {
/* Some other ECMP entries still exist. Just delete this entry.
*/
RIP_TIMER_OFF(rinfo->t_garbage_collect);
listnode_delete(list, rinfo);
if (rip_route_rte(rinfo)
&& CHECK_FLAG(rinfo->flags, RIP_RTF_FIB))
/* The ADD message implies the update. */
rip_zebra_ipv4_add(rp);
rip_info_free(rinfo);
rinfo = NULL;
} else {
assert(rinfo == listgetdata(listhead(list)));
/* This is the only entry left in the list. We must keep it in
* the list for garbage collection time, with INFINITY metric.
*/
rinfo->metric = RIP_METRIC_INFINITY;
RIP_TIMER_ON(rinfo->t_garbage_collect, rip_garbage_collect,
rip->garbage_time);
if (rip_route_rte(rinfo)
&& CHECK_FLAG(rinfo->flags, RIP_RTF_FIB))
rip_zebra_ipv4_delete(rp);
}
/* Set the route change flag on the first entry. */
rinfo = listgetdata(listhead(list));
SET_FLAG(rinfo->flags, RIP_RTF_CHANGED);
/* Signal the output process to trigger an update (see section 2.5). */
rip_event(RIP_TRIGGERED_UPDATE, 0);
return rinfo;
}
/* Timeout RIP routes. */
static int rip_timeout(struct thread *t)
{
rip_ecmp_delete((struct rip_info *)THREAD_ARG(t));
return 0;
}
static void rip_timeout_update(struct rip_info *rinfo)
{
if (rinfo->metric != RIP_METRIC_INFINITY) {
RIP_TIMER_OFF(rinfo->t_timeout);
RIP_TIMER_ON(rinfo->t_timeout, rip_timeout, rip->timeout_time);
}
}
static int rip_filter(int rip_distribute, struct prefix_ipv4 *p,
struct rip_interface *ri)
{
struct distribute *dist;
struct access_list *alist;
struct prefix_list *plist;
int distribute = rip_distribute == RIP_FILTER_OUT ? DISTRIBUTE_V4_OUT
: DISTRIBUTE_V4_IN;
const char *inout = rip_distribute == RIP_FILTER_OUT ? "out" : "in";
/* Input distribute-list filtering. */
if (ri->list[rip_distribute]) {
if (access_list_apply(ri->list[rip_distribute],
(struct prefix *)p)
== FILTER_DENY) {
if (IS_RIP_DEBUG_PACKET)
zlog_debug("%s/%d filtered by distribute %s",
inet_ntoa(p->prefix), p->prefixlen,
inout);
return -1;
}
}
if (ri->prefix[rip_distribute]) {
if (prefix_list_apply(ri->prefix[rip_distribute],
(struct prefix *)p)
== PREFIX_DENY) {
if (IS_RIP_DEBUG_PACKET)
zlog_debug("%s/%d filtered by prefix-list %s",
inet_ntoa(p->prefix), p->prefixlen,
inout);
return -1;
}
}
/* All interface filter check. */
dist = distribute_lookup(NULL);
if (dist) {
if (dist->list[distribute]) {
alist = access_list_lookup(AFI_IP,
dist->list[distribute]);
if (alist) {
if (access_list_apply(alist, (struct prefix *)p)
== FILTER_DENY) {
if (IS_RIP_DEBUG_PACKET)
zlog_debug(
"%s/%d filtered by distribute %s",
inet_ntoa(p->prefix),
p->prefixlen, inout);
return -1;
}
}
}
if (dist->prefix[distribute]) {
plist = prefix_list_lookup(AFI_IP,
dist->prefix[distribute]);
if (plist) {
if (prefix_list_apply(plist, (struct prefix *)p)
== PREFIX_DENY) {
if (IS_RIP_DEBUG_PACKET)
zlog_debug(
"%s/%d filtered by prefix-list %s",
inet_ntoa(p->prefix),
p->prefixlen, inout);
return -1;
}
}
}
}
return 0;
}
/* Check nexthop address validity. */
static int rip_nexthop_check(struct in_addr *addr)
{
struct vrf *vrf = vrf_lookup_by_id(VRF_DEFAULT);
struct interface *ifp;
struct listnode *cnode;
struct connected *ifc;
struct prefix *p;
/* If nexthop address matches local configured address then it is
invalid nexthop. */
FOR_ALL_INTERFACES (vrf, ifp) {
for (ALL_LIST_ELEMENTS_RO(ifp->connected, cnode, ifc)) {
p = ifc->address;
if (p->family == AF_INET
&& IPV4_ADDR_SAME(&p->u.prefix4, addr))
return -1;
}
}
return 0;
}
/* RIP add route to routing table. */
static void rip_rte_process(struct rte *rte, struct sockaddr_in *from,
struct interface *ifp)
{
int ret;
struct prefix_ipv4 p;
struct route_node *rp;
struct rip_info *rinfo = NULL, newinfo;
struct rip_interface *ri;
struct in_addr *nexthop;
int same = 0;
unsigned char old_dist, new_dist;
struct list *list = NULL;
struct listnode *node = NULL;
/* Make prefix structure. */
memset(&p, 0, sizeof(struct prefix_ipv4));
p.family = AF_INET;
p.prefix = rte->prefix;
p.prefixlen = ip_masklen(rte->mask);
/* Make sure mask is applied. */
apply_mask_ipv4(&p);
/* Apply input filters. */
ri = ifp->info;
ret = rip_filter(RIP_FILTER_IN, &p, ri);
if (ret < 0)
return;
memset(&newinfo, 0, sizeof(newinfo));
newinfo.type = ZEBRA_ROUTE_RIP;
newinfo.sub_type = RIP_ROUTE_RTE;
newinfo.nh.gate.ipv4 = rte->nexthop;
newinfo.from = from->sin_addr;
newinfo.nh.ifindex = ifp->ifindex;
newinfo.nh.type = NEXTHOP_TYPE_IPV4_IFINDEX;
newinfo.metric = rte->metric;
newinfo.metric_out = rte->metric; /* XXX */
newinfo.tag = ntohs(rte->tag); /* XXX */
/* Modify entry according to the interface routemap. */
if (ri->routemap[RIP_FILTER_IN]) {
int ret;
/* The object should be of the type of rip_info */
ret = route_map_apply(ri->routemap[RIP_FILTER_IN],
(struct prefix *)&p, RMAP_RIP, &newinfo);
if (ret == RMAP_DENYMATCH) {
if (IS_RIP_DEBUG_PACKET)
zlog_debug(
"RIP %s/%d is filtered by route-map in",
inet_ntoa(p.prefix), p.prefixlen);
return;
}
/* Get back the object */
rte->nexthop = newinfo.nexthop_out;
rte->tag = htons(newinfo.tag_out); /* XXX */
rte->metric = newinfo.metric_out; /* XXX: the routemap uses the
metric_out field */
}
/* Once the entry has been validated, update the metric by
adding the cost of the network on wich the message
arrived. If the result is greater than infinity, use infinity
(RFC2453 Sec. 3.9.2) */
/* Zebra ripd can handle offset-list in. */
ret = rip_offset_list_apply_in(&p, ifp, &rte->metric);
/* If offset-list does not modify the metric use interface's
metric. */
if (!ret)
rte->metric += ifp->metric ? ifp->metric : 1;
if (rte->metric > RIP_METRIC_INFINITY)
rte->metric = RIP_METRIC_INFINITY;
/* Set nexthop pointer. */
if (rte->nexthop.s_addr == 0)
nexthop = &from->sin_addr;
else
nexthop = &rte->nexthop;
/* Check if nexthop address is myself, then do nothing. */
if (rip_nexthop_check(nexthop) < 0) {
if (IS_RIP_DEBUG_PACKET)
zlog_debug("Nexthop address %s is myself",
inet_ntoa(*nexthop));
return;
}
/* Get index for the prefix. */
rp = route_node_get(rip->table, (struct prefix *)&p);
newinfo.rp = rp;
newinfo.nh.gate.ipv4 = *nexthop;
newinfo.nh.type = NEXTHOP_TYPE_IPV4;
newinfo.metric = rte->metric;
newinfo.tag = ntohs(rte->tag);
newinfo.distance = rip_distance_apply(&newinfo);
new_dist = newinfo.distance ? newinfo.distance
: ZEBRA_RIP_DISTANCE_DEFAULT;
/* Check to see whether there is already RIP route on the table. */
if ((list = rp->info) != NULL)
for (ALL_LIST_ELEMENTS_RO(list, node, rinfo)) {
/* Need to compare with redistributed entry or local
* entry */
if (!rip_route_rte(rinfo))
break;
if (IPV4_ADDR_SAME(&rinfo->from, &from->sin_addr)
&& IPV4_ADDR_SAME(&rinfo->nh.gate.ipv4, nexthop))
break;
if (!listnextnode(node)) {
/* Not found in the list */
if (rte->metric > rinfo->metric) {
/* New route has a greater metric.
* Discard it. */
route_unlock_node(rp);
return;
}
if (rte->metric < rinfo->metric)
/* New route has a smaller metric.
* Replace the ECMP list
* with the new one in below. */
break;
/* Metrics are same. We compare the distances.
*/
old_dist = rinfo->distance
? rinfo->distance
: ZEBRA_RIP_DISTANCE_DEFAULT;
if (new_dist > old_dist) {
/* New route has a greater distance.
* Discard it. */
route_unlock_node(rp);
return;
}
if (new_dist < old_dist)
/* New route has a smaller distance.
* Replace the ECMP list
* with the new one in below. */
break;
/* Metrics and distances are both same. Keep
* "rinfo" null and
* the new route is added in the ECMP list in
* below. */
}
}
if (rinfo) {
/* Local static route. */
if (rinfo->type == ZEBRA_ROUTE_RIP
&& ((rinfo->sub_type == RIP_ROUTE_STATIC)
|| (rinfo->sub_type == RIP_ROUTE_DEFAULT))
&& rinfo->metric != RIP_METRIC_INFINITY) {
route_unlock_node(rp);
return;
}
/* Redistributed route check. */
if (rinfo->type != ZEBRA_ROUTE_RIP
&& rinfo->metric != RIP_METRIC_INFINITY) {
old_dist = rinfo->distance;
/* Only routes directly connected to an interface
* (nexthop == 0)
* may have a valid NULL distance */
if (rinfo->nh.gate.ipv4.s_addr != 0)
old_dist = old_dist
? old_dist
: ZEBRA_RIP_DISTANCE_DEFAULT;
/* If imported route does not have STRICT precedence,
mark it as a ghost */
if (new_dist <= old_dist
&& rte->metric != RIP_METRIC_INFINITY)
rip_ecmp_replace(&newinfo);
route_unlock_node(rp);
return;
}
}
if (!rinfo) {
if (rp->info)
route_unlock_node(rp);
/* Now, check to see whether there is already an explicit route
for the destination prefix. If there is no such route, add
this route to the routing table, unless the metric is
infinity (there is no point in adding a route which
unusable). */
if (rte->metric != RIP_METRIC_INFINITY)
rip_ecmp_add(&newinfo);
} else {
/* Route is there but we are not sure the route is RIP or not.
*/
/* If there is an existing route, compare the next hop address
to the address of the router from which the datagram came.
If this datagram is from the same router as the existing
route, reinitialize the timeout. */
same = (IPV4_ADDR_SAME(&rinfo->from, &from->sin_addr)
&& (rinfo->nh.ifindex == ifp->ifindex));
old_dist = rinfo->distance ? rinfo->distance
: ZEBRA_RIP_DISTANCE_DEFAULT;
/* Next, compare the metrics. If the datagram is from the same
router as the existing route, and the new metric is different
than the old one; or, if the new metric is lower than the old
one, or if the tag has been changed; or if there is a route
with a lower administrave distance; or an update of the
distance on the actual route; do the following actions: */
if ((same && rinfo->metric != rte->metric)
|| (rte->metric < rinfo->metric)
|| ((same) && (rinfo->metric == rte->metric)
&& (newinfo.tag != rinfo->tag))
|| (old_dist > new_dist)
|| ((old_dist != new_dist) && same)) {
if (listcount(list) == 1) {
if (newinfo.metric != RIP_METRIC_INFINITY)
rip_ecmp_replace(&newinfo);
else
rip_ecmp_delete(rinfo);
} else {
if (newinfo.metric < rinfo->metric)
rip_ecmp_replace(&newinfo);
else if (newinfo.metric > rinfo->metric)
rip_ecmp_delete(rinfo);
else if (new_dist < old_dist)
rip_ecmp_replace(&newinfo);
else if (new_dist > old_dist)
rip_ecmp_delete(rinfo);
else {
int update = CHECK_FLAG(rinfo->flags,
RIP_RTF_FIB)
? 1
: 0;
assert(newinfo.metric
!= RIP_METRIC_INFINITY);
RIP_TIMER_OFF(rinfo->t_timeout);
RIP_TIMER_OFF(rinfo->t_garbage_collect);
memcpy(rinfo, &newinfo,
sizeof(struct rip_info));
rip_timeout_update(rinfo);
if (update)
rip_zebra_ipv4_add(rp);
/* - Set the route change flag on the
* first entry. */
rinfo = listgetdata(listhead(list));
SET_FLAG(rinfo->flags, RIP_RTF_CHANGED);
rip_event(RIP_TRIGGERED_UPDATE, 0);
}
}
} else /* same & no change */
rip_timeout_update(rinfo);
/* Unlock tempolary lock of the route. */
route_unlock_node(rp);
}
}
/* Dump RIP packet */
static void rip_packet_dump(struct rip_packet *packet, int size,
const char *sndrcv)
{
caddr_t lim;
struct rte *rte;
const char *command_str;
char pbuf[BUFSIZ], nbuf[BUFSIZ];
uint8_t netmask = 0;
uint8_t *p;
/* Set command string. */
if (packet->command > 0 && packet->command < RIP_COMMAND_MAX)
command_str = lookup_msg(rip_msg, packet->command, NULL);
else
command_str = "unknown";
/* Dump packet header. */
zlog_debug("%s %s version %d packet size %d", sndrcv, command_str,
packet->version, size);
/* Dump each routing table entry. */
rte = packet->rte;
for (lim = (caddr_t)packet + size; (caddr_t)rte < lim; rte++) {
if (packet->version == RIPv2) {
netmask = ip_masklen(rte->mask);
if (rte->family == htons(RIP_FAMILY_AUTH)) {
if (rte->tag
== htons(RIP_AUTH_SIMPLE_PASSWORD)) {
p = (uint8_t *)&rte->prefix;
zlog_debug(
" family 0x%X type %d auth string: %s",
ntohs(rte->family),
ntohs(rte->tag), p);
} else if (rte->tag == htons(RIP_AUTH_MD5)) {
struct rip_md5_info *md5;
md5 = (struct rip_md5_info *)&packet
->rte;
zlog_debug(
" family 0x%X type %d (MD5 authentication)",
ntohs(md5->family),
ntohs(md5->type));
zlog_debug(
" RIP-2 packet len %d Key ID %d"
" Auth Data len %d",
ntohs(md5->packet_len),
md5->keyid, md5->auth_len);
zlog_debug(" Sequence Number %ld",
(unsigned long)ntohl(
md5->sequence));
} else if (rte->tag == htons(RIP_AUTH_DATA)) {
p = (uint8_t *)&rte->prefix;
zlog_debug(
" family 0x%X type %d (MD5 data)",
ntohs(rte->family),
ntohs(rte->tag));
zlog_debug(
" MD5: %02X%02X%02X%02X%02X%02X%02X%02X"
"%02X%02X%02X%02X%02X%02X%02X%02X",
p[0], p[1], p[2], p[3], p[4],
p[5], p[6], p[7], p[8], p[9],
p[10], p[11], p[12], p[13],
p[14], p[15]);
} else {
zlog_debug(
" family 0x%X type %d (Unknown auth type)",
ntohs(rte->family),
ntohs(rte->tag));
}
} else
zlog_debug(
" %s/%d -> %s family %d tag %" ROUTE_TAG_PRI
" metric %ld",
inet_ntop(AF_INET, &rte->prefix, pbuf,
BUFSIZ),
netmask,
inet_ntop(AF_INET, &rte->nexthop, nbuf,
BUFSIZ),
ntohs(rte->family),
(route_tag_t)ntohs(rte->tag),
(unsigned long)ntohl(rte->metric));
} else {
zlog_debug(
" %s family %d tag %" ROUTE_TAG_PRI
" metric %ld",
inet_ntop(AF_INET, &rte->prefix, pbuf, BUFSIZ),
ntohs(rte->family),
(route_tag_t)ntohs(rte->tag),
(unsigned long)ntohl(rte->metric));
}
}
}
/* Check if the destination address is valid (unicast; not net 0
or 127) (RFC2453 Section 3.9.2 - Page 26). But we don't
check net 0 because we accept default route. */
static int rip_destination_check(struct in_addr addr)
{
uint32_t destination;
/* Convert to host byte order. */
destination = ntohl(addr.s_addr);
if (IPV4_NET127(destination))
return 0;
/* Net 0 may match to the default route. */
if (IPV4_NET0(destination) && destination != 0)
return 0;
/* Unicast address must belong to class A, B, C. */
if (IN_CLASSA(destination))
return 1;
if (IN_CLASSB(destination))
return 1;
if (IN_CLASSC(destination))
return 1;
return 0;
}
/* RIP version 2 authentication. */
static int rip_auth_simple_password(struct rte *rte, struct sockaddr_in *from,
struct interface *ifp)
{
struct rip_interface *ri;
char *auth_str = (char *)rte + offsetof(struct rte, prefix);
int i;
/* reject passwords with zeros in the middle of the string */
for (i = strnlen(auth_str, 16); i < 16; i++) {
if (auth_str[i] != '\0')
return 0;
}
if (IS_RIP_DEBUG_EVENT)
zlog_debug("RIPv2 simple password authentication from %s",
inet_ntoa(from->sin_addr));
ri = ifp->info;
if (ri->auth_type != RIP_AUTH_SIMPLE_PASSWORD
|| rte->tag != htons(RIP_AUTH_SIMPLE_PASSWORD))
return 0;
/* Simple password authentication. */
if (ri->auth_str) {
if (strncmp(auth_str, ri->auth_str, 16) == 0)
return 1;
}
if (ri->key_chain) {
struct keychain *keychain;
struct key *key;
keychain = keychain_lookup(ri->key_chain);
if (keychain == NULL || keychain->key == NULL)
return 0;
key = key_match_for_accept(keychain, auth_str);
if (key)
return 1;
}
return 0;
}
/* RIP version 2 authentication with MD5. */
static int rip_auth_md5(struct rip_packet *packet, struct sockaddr_in *from,
int length, struct interface *ifp)
{
struct rip_interface *ri;
struct rip_md5_info *md5;
struct rip_md5_data *md5data;
struct keychain *keychain;
struct key *key;
MD5_CTX ctx;
uint8_t digest[RIP_AUTH_MD5_SIZE];
uint16_t packet_len;
char auth_str[RIP_AUTH_MD5_SIZE];
if (IS_RIP_DEBUG_EVENT)
zlog_debug("RIPv2 MD5 authentication from %s",
inet_ntoa(from->sin_addr));
ri = ifp->info;
md5 = (struct rip_md5_info *)&packet->rte;
/* Check auth type. */
if (ri->auth_type != RIP_AUTH_MD5 || md5->type != htons(RIP_AUTH_MD5))
return 0;
/* If the authentication length is less than 16, then it must be wrong
* for
* any interpretation of rfc2082. Some implementations also interpret
* this as RIP_HEADER_SIZE+ RIP_AUTH_MD5_SIZE, aka
* RIP_AUTH_MD5_COMPAT_SIZE.
*/
if (!((md5->auth_len == RIP_AUTH_MD5_SIZE)
|| (md5->auth_len == RIP_AUTH_MD5_COMPAT_SIZE))) {
if (IS_RIP_DEBUG_EVENT)
zlog_debug(
"RIPv2 MD5 authentication, strange authentication "
"length field %d",
md5->auth_len);
return 0;
}
/* grab and verify check packet length */
packet_len = ntohs(md5->packet_len);
if (packet_len > (length - RIP_HEADER_SIZE - RIP_AUTH_MD5_SIZE)) {
if (IS_RIP_DEBUG_EVENT)
zlog_debug(
"RIPv2 MD5 authentication, packet length field %d "
"greater than received length %d!",
md5->packet_len, length);
return 0;
}
/* retrieve authentication data */
md5data = (struct rip_md5_data *)(((uint8_t *)packet) + packet_len);
memset(auth_str, 0, RIP_AUTH_MD5_SIZE);
if (ri->key_chain) {
keychain = keychain_lookup(ri->key_chain);
if (keychain == NULL)
return 0;
key = key_lookup_for_accept(keychain, md5->keyid);
if (key == NULL || key->string == NULL)
return 0;
strncpy(auth_str, key->string, RIP_AUTH_MD5_SIZE);
} else if (ri->auth_str)
strncpy(auth_str, ri->auth_str, RIP_AUTH_MD5_SIZE);
if (auth_str[0] == 0)
return 0;
/* MD5 digest authentication. */
memset(&ctx, 0, sizeof(ctx));
MD5Init(&ctx);
MD5Update(&ctx, packet, packet_len + RIP_HEADER_SIZE);
MD5Update(&ctx, auth_str, RIP_AUTH_MD5_SIZE);
MD5Final(digest, &ctx);
if (memcmp(md5data->digest, digest, RIP_AUTH_MD5_SIZE) == 0)
return packet_len;
else
return 0;
}
/* Pick correct auth string for sends, prepare auth_str buffer for use.
* (left justified and padded).
*
* presumes one of ri or key is valid, and that the auth strings they point
* to are nul terminated. If neither are present, auth_str will be fully
* zero padded.
*
*/
static void rip_auth_prepare_str_send(struct rip_interface *ri, struct key *key,
char *auth_str, int len)
{
assert(ri || key);
memset(auth_str, 0, len);
if (key && key->string)
strncpy(auth_str, key->string, len);
else if (ri->auth_str)
strncpy(auth_str, ri->auth_str, len);
return;
}
/* Write RIPv2 simple password authentication information
*
* auth_str is presumed to be 2 bytes and correctly prepared
* (left justified and zero padded).
*/
static void rip_auth_simple_write(struct stream *s, char *auth_str, int len)
{
assert(s && len == RIP_AUTH_SIMPLE_SIZE);
stream_putw(s, RIP_FAMILY_AUTH);
stream_putw(s, RIP_AUTH_SIMPLE_PASSWORD);
stream_put(s, auth_str, RIP_AUTH_SIMPLE_SIZE);
return;
}
/* write RIPv2 MD5 "authentication header"
* (uses the auth key data field)
*
* Digest offset field is set to 0.
*
* returns: offset of the digest offset field, which must be set when
* length to the auth-data MD5 digest is known.
*/
static size_t rip_auth_md5_ah_write(struct stream *s, struct rip_interface *ri,
struct key *key)
{
size_t doff = 0;
assert(s && ri && ri->auth_type == RIP_AUTH_MD5);
/* MD5 authentication. */
stream_putw(s, RIP_FAMILY_AUTH);
stream_putw(s, RIP_AUTH_MD5);
/* MD5 AH digest offset field.
*
* Set to placeholder value here, to true value when RIP-2 Packet length
* is known. Actual value is set in .....().
*/
doff = stream_get_endp(s);
stream_putw(s, 0);
/* Key ID. */
if (key)
stream_putc(s, key->index % 256);
else
stream_putc(s, 1);