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vif.c
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vif.c
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/* $NetBSD: vif.c,v 1.6 1995/12/10 10:07:19 mycroft Exp $ */
/*
* The mrouted program is covered by the license in the accompanying file
* named "LICENSE". Use of the mrouted program represents acceptance of
* the terms and conditions listed in that file.
*
* The mrouted program is COPYRIGHT 1989 by The Board of Trustees of
* Leland Stanford Junior University.
*/
#include "defs.h"
#include <fcntl.h>
/*
* Exported variables.
*/
struct uvif uvifs[MAXVIFS]; /* array of virtual interfaces */
vifi_t numvifs; /* number of vifs in use */
int vifs_down; /* 1=>some interfaces are down */
int phys_vif; /* An enabled vif */
int udp_socket; /* Since the honkin' kernel doesn't support */
/* ioctls on raw IP sockets, we need a UDP */
/* socket as well as our IGMP (raw) socket. */
/* How dumb. */
int vifs_with_neighbors; /* == 1 if I am a leaf */
typedef struct {
vifi_t vifi;
struct listaddr *g;
int q_time;
} cbk_t;
/*
* Forward declarations.
*/
static void start_vif(vifi_t vifi);
static void start_vif2(vifi_t vifi);
static void stop_vif(vifi_t vifi);
static void age_old_hosts(void);
static void send_probe_on_vif(struct uvif *v);
static int info_version(char *p, int);
static void DelVif(void *arg);
static int SetTimer(int vifi, struct listaddr *g);
static int DeleteTimer(int id);
static void SendQuery(void *arg);
static int SetQueryTimer(struct listaddr *g, vifi_t vifi, int to_expire,
int q_time);
/*
* Initialize the virtual interfaces, but do not install
* them in the kernel. Start routing on all vifs that are
* not down or disabled.
*/
void
init_vifs(void)
{
vifi_t vifi;
struct uvif *v;
int enabled_vifs, enabled_phyints;
extern char *configfilename;
numvifs = 0;
vifs_with_neighbors = 0;
vifs_down = FALSE;
/*
* Configure the vifs based on the interface configuration of the
* the kernel and the contents of the configuration file.
* (Open a UDP socket for ioctl use in the config procedures.)
*/
if ((udp_socket = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
logit(LOG_ERR, errno, "UDP socket");
logit(LOG_INFO,0,"Getting vifs from kernel interfaces");
config_vifs_from_kernel();
logit(LOG_INFO,0,"Getting vifs from %s",configfilename);
config_vifs_from_file();
/*
* Quit if there are fewer than two enabled vifs.
*/
enabled_vifs = 0;
enabled_phyints = 0;
phys_vif = -1;
for (vifi = 0, v = uvifs; vifi < numvifs; ++vifi, ++v) {
if (!(v->uv_flags & VIFF_DISABLED)) {
++enabled_vifs;
if (!(v->uv_flags & VIFF_TUNNEL)) {
if (phys_vif == -1)
phys_vif = vifi;
++enabled_phyints;
}
}
}
if (enabled_vifs < 2)
logit(LOG_ERR, 0, "can't forward: %s",
enabled_vifs == 0 ? "no enabled vifs" : "only one enabled vif");
if (enabled_phyints == 0)
logit(LOG_WARNING, 0,
"no enabled interfaces, forwarding via tunnels only");
logit(LOG_INFO, 0, "Installing vifs in mrouted...");
for (vifi = 0, v = uvifs; vifi < numvifs; ++vifi, ++v) {
if (!(v->uv_flags & VIFF_DISABLED)) {
if (!(v->uv_flags & VIFF_DOWN)) {
if (v->uv_flags & VIFF_TUNNEL)
logit(LOG_INFO, 0, "vif #%d, tunnel %s -> %s", vifi,
inet_fmt(v->uv_lcl_addr, s1),
inet_fmt(v->uv_rmt_addr, s2));
else
logit(LOG_INFO, 0, "vif #%d, phyint %s", vifi,
inet_fmt(v->uv_lcl_addr, s1));
start_vif2(vifi);
} else logit(LOG_INFO, 0,
"%s is not yet up; vif #%u not in service",
v->uv_name, vifi);
}
}
}
/*
* Start routing on all virtual interfaces that are not down or
* administratively disabled.
*/
void
init_installvifs(void)
{
vifi_t vifi;
struct uvif *v;
logit(LOG_INFO, 0, "Installing vifs in kernel...");
for (vifi = 0, v = uvifs; vifi < numvifs; ++vifi, ++v) {
if (!(v->uv_flags & VIFF_DISABLED)) {
if (!(v->uv_flags & VIFF_DOWN)) {
if (v->uv_flags & VIFF_TUNNEL)
logit(LOG_INFO, 0, "vif #%d, tunnel %s -> %s", vifi,
inet_fmt(v->uv_lcl_addr, s1),
inet_fmt(v->uv_rmt_addr, s2));
else
logit(LOG_INFO, 0, "vif #%d, phyint %s", vifi,
inet_fmt(v->uv_lcl_addr, s1));
k_add_vif(vifi, &uvifs[vifi]);
} else logit(LOG_INFO, 0,
"%s is not yet up; vif #%u not in service",
v->uv_name, vifi);
}
}
}
/*
* See if any interfaces have changed from up state to down, or vice versa,
* including any non-multicast-capable interfaces that are in use as local
* tunnel end-points. Ignore interfaces that have been administratively
* disabled.
*/
void
check_vif_state(void)
{
vifi_t vifi;
struct uvif *v;
struct ifreq ifr;
vifs_down = FALSE;
for (vifi = 0, v = uvifs; vifi < numvifs; ++vifi, ++v) {
if (v->uv_flags & VIFF_DISABLED) continue;
strncpy(ifr.ifr_name, v->uv_name, IFNAMSIZ);
if (ioctl(udp_socket, SIOCGIFFLAGS, (char *)&ifr) == -1)
logit(LOG_ERR, errno,
"ioctl SIOCGIFFLAGS for %s", ifr.ifr_name);
if (v->uv_flags & VIFF_DOWN) {
if (ifr.ifr_flags & IFF_UP) {
v->uv_flags &= ~VIFF_DOWN;
start_vif(vifi);
logit(LOG_INFO, 0,
"%s has come up; vif #%u now in service",
v->uv_name, vifi);
}
else vifs_down = TRUE;
}
else {
if (!(ifr.ifr_flags & IFF_UP)) {
stop_vif(vifi);
v->uv_flags |= VIFF_DOWN;
logit(LOG_INFO, 0,
"%s has gone down; vif #%u taken out of service",
v->uv_name, vifi);
vifs_down = TRUE;
}
}
}
}
/*
* Send a probe message on vif v
*/
static void
send_probe_on_vif(struct uvif *v)
{
char *p;
int datalen = 0;
struct listaddr *nbr;
int i;
p = send_buf + MIN_IP_HEADER_LEN + IGMP_MINLEN;
for (i = 0; i < 4; i++)
*p++ = ((char *)&(dvmrp_genid))[i];
datalen += 4;
/*
* add the neighbor list on the interface to the message
*/
nbr = v->uv_neighbors;
while (nbr) {
for (i = 0; i < 4; i++)
*p++ = ((char *)&nbr->al_addr)[i];
datalen +=4;
nbr = nbr->al_next;
}
send_igmp(v->uv_lcl_addr,
(v->uv_flags & VIFF_TUNNEL) ? v->uv_rmt_addr
: dvmrp_group,
IGMP_DVMRP, DVMRP_PROBE,
htonl(MROUTED_LEVEL |
((v->uv_flags & VIFF_LEAF) ? 0 : LEAF_FLAGS)),
datalen);
}
/*
* Add a vifi to the kernel and start routing on it.
*/
static void
start_vif(vifi_t vifi)
{
/*
* Install the interface in the kernel's vif structure.
*/
k_add_vif(vifi, &uvifs[vifi]);
start_vif2(vifi);
}
/*
* Add a vifi to all the user-level data structures but don't add
* it to the kernel yet.
*/
static void
start_vif2(vifi_t vifi)
{
struct uvif *v;
u_int32_t src;
struct phaddr *p;
v = &uvifs[vifi];
src = v->uv_lcl_addr;
/*
* Update the existing route entries to take into account the new vif.
*/
add_vif_to_routes(vifi);
if (!(v->uv_flags & VIFF_TUNNEL)) {
/*
* Join the DVMRP multicast group on the interface.
* (This is not strictly necessary, since the kernel promiscuously
* receives IGMP packets addressed to ANY IP multicast group while
* multicast routing is enabled. However, joining the group allows
* this host to receive non-IGMP packets as well, such as 'pings'.)
*/
k_join(dvmrp_group, src);
/*
* Join the ALL-ROUTERS multicast group on the interface.
* This allows mtrace requests to loop back if they are run
* on the multicast router.
*/
k_join(allrtrs_group, src);
/*
* Install an entry in the routing table for the subnet to which
* the interface is connected.
*/
start_route_updates();
update_route(v->uv_subnet, v->uv_subnetmask, 0, 0, vifi);
for (p = v->uv_addrs; p; p = p->pa_next) {
start_route_updates();
update_route(p->pa_subnet, p->pa_subnetmask, 0, 0, vifi);
}
/*
* Until neighbors are discovered, assume responsibility for sending
* periodic group membership queries to the subnet. Send the first
* query.
*/
v->uv_flags |= VIFF_QUERIER;
send_igmp(src, allhosts_group, IGMP_HOST_MEMBERSHIP_QUERY,
(v->uv_flags & VIFF_IGMPV1) ? 0 :
IGMP_MAX_HOST_REPORT_DELAY * IGMP_TIMER_SCALE, 0, 0);
age_old_hosts();
}
v->uv_leaf_timer = LEAF_CONFIRMATION_TIME;
/*
* Send a probe via the new vif to look for neighbors.
*/
send_probe_on_vif(v);
}
/*
* Stop routing on the specified virtual interface.
*/
static void
stop_vif(vifi_t vifi)
{
struct uvif *v;
struct listaddr *a;
struct phaddr *p;
v = &uvifs[vifi];
if (!(v->uv_flags & VIFF_TUNNEL)) {
/*
* Depart from the DVMRP multicast group on the interface.
*/
k_leave(dvmrp_group, v->uv_lcl_addr);
/*
* Depart from the ALL-ROUTERS multicast group on the interface.
*/
k_leave(allrtrs_group, v->uv_lcl_addr);
/*
* Update the entry in the routing table for the subnet to which
* the interface is connected, to take into account the interface
* failure.
*/
start_route_updates();
update_route(v->uv_subnet, v->uv_subnetmask, UNREACHABLE, 0, vifi);
for (p = v->uv_addrs; p; p = p->pa_next) {
start_route_updates();
update_route(p->pa_subnet, p->pa_subnetmask, UNREACHABLE, 0, vifi);
}
/*
* Discard all group addresses. (No need to tell kernel;
* the k_del_vif() call, below, will clean up kernel state.)
*/
while (v->uv_groups != NULL) {
a = v->uv_groups;
v->uv_groups = a->al_next;
free((char *)a);
}
v->uv_flags &= ~VIFF_QUERIER;
}
/*
* Update the existing route entries to take into account the vif failure.
*/
delete_vif_from_routes(vifi);
/*
* Delete the interface from the kernel's vif structure.
*/
k_del_vif(vifi);
/*
* Discard all neighbor addresses.
*/
if (v->uv_neighbors)
vifs_with_neighbors--;
while (v->uv_neighbors != NULL) {
a = v->uv_neighbors;
v->uv_neighbors = a->al_next;
free((char *)a);
}
}
/*
* stop routing on all vifs
*/
void
stop_all_vifs(void)
{
vifi_t vifi;
struct uvif *v;
struct listaddr *a;
struct vif_acl *acl;
for (vifi = 0; vifi < numvifs; vifi++) {
v = &uvifs[vifi];
while (v->uv_groups != NULL) {
a = v->uv_groups;
v->uv_groups = a->al_next;
free((char *)a);
}
while (v->uv_neighbors != NULL) {
a = v->uv_neighbors;
v->uv_neighbors = a->al_next;
free((char *)a);
}
while (v->uv_acl != NULL) {
acl = v->uv_acl;
v->uv_acl = acl->acl_next;
free((char *)acl);
}
}
}
/*
* Find the virtual interface from which an incoming packet arrived,
* based on the packet's source and destination IP addresses.
*/
vifi_t
find_vif(u_int32_t src, u_int32_t dst)
{
vifi_t vifi;
struct uvif *v;
struct phaddr *p;
for (vifi = 0, v = uvifs; vifi < numvifs; ++vifi, ++v) {
if (!(v->uv_flags & (VIFF_DOWN|VIFF_DISABLED))) {
if (v->uv_flags & VIFF_TUNNEL) {
if (src == v->uv_rmt_addr && dst == v->uv_lcl_addr)
return(vifi);
}
else {
if ((src & v->uv_subnetmask) == v->uv_subnet &&
((v->uv_subnetmask == 0xffffffff) ||
(src != v->uv_subnetbcast)))
return(vifi);
for (p=v->uv_addrs; p; p=p->pa_next) {
if ((src & p->pa_subnetmask) == p->pa_subnet &&
((p->pa_subnetmask == 0xffffffff) ||
(src != p->pa_subnetbcast)))
return(vifi);
}
}
}
}
return (NO_VIF);
}
static void
age_old_hosts(void)
{
vifi_t vifi;
struct uvif *v;
struct listaddr *g;
/*
* Decrement the old-hosts-present timer for each
* active group on each vif.
*/
for (vifi = 0, v = uvifs; vifi < numvifs; vifi++, v++)
for (g = v->uv_groups; g != NULL; g = g->al_next)
if (g->al_old)
g->al_old--;
}
/*
* Send group membership queries to all subnets for which I am querier.
*/
void
query_groups(void)
{
vifi_t vifi;
struct uvif *v;
for (vifi = 0, v = uvifs; vifi < numvifs; vifi++, v++) {
if (v->uv_flags & VIFF_QUERIER) {
send_igmp(v->uv_lcl_addr, allhosts_group,
IGMP_HOST_MEMBERSHIP_QUERY,
(v->uv_flags & VIFF_IGMPV1) ? 0 :
IGMP_MAX_HOST_REPORT_DELAY * IGMP_TIMER_SCALE, 0, 0);
}
}
age_old_hosts();
}
/*
* Process an incoming host membership query
*/
void
accept_membership_query(u_int32_t src, u_int32_t dst, u_int32_t group,
int tmo)
{
vifi_t vifi;
struct uvif *v;
if ((vifi = find_vif(src, dst)) == NO_VIF ||
(uvifs[vifi].uv_flags & VIFF_TUNNEL)) {
logit(LOG_INFO, 0,
"ignoring group membership query from non-adjacent host %s",
inet_fmt(src, s1));
return;
}
v = &uvifs[vifi];
/*
* If we consider ourselves the querier for this vif, but hear a
* query from a router with a lower IP address, yield to them.
*
* This is done here as well as in the neighbor discovery in case
* there is a querier that doesn't speak DVMRP.
*
* XXX If this neighbor doesn't speak DVMRP, then we need to create
* some neighbor state for him so that we can time him out!
*/
if ((v->uv_flags & VIFF_QUERIER) &&
(ntohl(src) < ntohl(v->uv_lcl_addr))) {
v->uv_flags &= ~VIFF_QUERIER;
}
}
/*
* Process an incoming group membership report.
*/
void
accept_group_report(u_int32_t src, u_int32_t dst, u_int32_t group,
int r_type)
{
vifi_t vifi;
struct uvif *v;
struct listaddr *g;
if ((vifi = find_vif(src, dst)) == NO_VIF ||
(uvifs[vifi].uv_flags & VIFF_TUNNEL)) {
logit(LOG_INFO, 0,
"ignoring group membership report from non-adjacent host %s",
inet_fmt(src, s1));
return;
}
v = &uvifs[vifi];
/*
* Look for the group in our group list; if found, reset its timer.
*/
for (g = v->uv_groups; g != NULL; g = g->al_next) {
if (group == g->al_addr) {
if (r_type == IGMP_v1_HOST_MEMBERSHIP_REPORT)
g->al_old = OLD_AGE_THRESHOLD;
/** delete old timers, set a timer for expiration **/
g->al_timer = GROUP_EXPIRE_TIME;
if (g->al_query)
g->al_query = DeleteTimer(g->al_query);
if (g->al_timerid)
g->al_timerid = DeleteTimer(g->al_timerid);
g->al_timerid = SetTimer(vifi, g);
break;
}
}
/*
* If not found, add it to the list and update kernel cache.
*/
if (g == NULL) {
g = malloc(sizeof(struct listaddr));
if (g == NULL)
logit(LOG_ERR, 0, "ran out of memory"); /* fatal */
g->al_addr = group;
if (r_type == IGMP_v2_HOST_MEMBERSHIP_REPORT)
g->al_old = 0;
else
g->al_old = OLD_AGE_THRESHOLD;
/** set a timer for expiration **/
g->al_query = 0;
g->al_timer = GROUP_EXPIRE_TIME;
time(&g->al_ctime);
g->al_timerid = SetTimer(vifi, g);
g->al_next = v->uv_groups;
v->uv_groups = g;
update_lclgrp(vifi, group);
}
/*
* Check if a graft is necessary for this group
*/
chkgrp_graft(vifi, group);
}
void
accept_leave_message(u_int32_t src, u_int32_t dst, u_int32_t group)
{
vifi_t vifi;
struct uvif *v;
struct listaddr *g;
if ((vifi = find_vif(src, dst)) == NO_VIF ||
(uvifs[vifi].uv_flags & VIFF_TUNNEL)) {
logit(LOG_INFO, 0,
"ignoring group leave report from non-adjacent host %s",
inet_fmt(src, s1));
return;
}
v = &uvifs[vifi];
if (!(v->uv_flags & VIFF_QUERIER) || (v->uv_flags & VIFF_IGMPV1))
return;
/*
* Look for the group in our group list in order to set up a short-timeout
* query.
*/
for (g = v->uv_groups; g != NULL; g = g->al_next) {
if (group == g->al_addr) {
logit(LOG_DEBUG, 0,
"[vif.c, _accept_leave_message] %d %d \n",
g->al_old, g->al_query);
/* Ignore the leave message if there are old hosts present */
if (g->al_old)
return;
/* still waiting for a reply to a query, ignore the leave */
if (g->al_query)
return;
/** delete old timer set a timer for expiration **/
if (g->al_timerid)
g->al_timerid = DeleteTimer(g->al_timerid);
/** send a group specific querry **/
g->al_timer = LEAVE_EXPIRE_TIME;
send_igmp(v->uv_lcl_addr, g->al_addr,
IGMP_HOST_MEMBERSHIP_QUERY,
LEAVE_EXPIRE_TIME / 3 * IGMP_TIMER_SCALE,
g->al_addr, 0);
g->al_query = SetQueryTimer(g, vifi, g->al_timer / 3,
LEAVE_EXPIRE_TIME / 3 * IGMP_TIMER_SCALE);
g->al_timerid = SetTimer(vifi, g);
break;
}
}
}
/*
* Send a periodic probe on all vifs.
* Useful to determine one-way interfaces.
* Detect neighbor loss faster.
*/
void
probe_for_neighbors(void)
{
vifi_t vifi;
struct uvif *v;
for (vifi = 0, v = uvifs; vifi < numvifs; vifi++, v++) {
if (!(v->uv_flags & (VIFF_DOWN|VIFF_DISABLED))) {
send_probe_on_vif(v);
}
}
}
/*
* Send a list of all of our neighbors to the requestor, `src'.
*/
void
accept_neighbor_request(u_int32_t src, u_int32_t dst)
{
vifi_t vifi;
struct uvif *v;
u_char *p, *ncount;
struct listaddr *la;
int datalen;
u_int32_t temp_addr, us, them = src;
/* Determine which of our addresses to use as the source of our response
* to this query.
*/
if (IN_MULTICAST(ntohl(dst))) { /* query sent to a multicast group */
int udp; /* find best interface to reply on */
struct sockaddr_in addr;
int addrlen = sizeof(addr);
memset(&addr, 0, sizeof addr);
addr.sin_family = AF_INET;
addr.sin_len = sizeof addr;
addr.sin_addr.s_addr = dst;
addr.sin_port = htons(2000); /* any port over 1024 will do... */
if ((udp = socket(AF_INET, SOCK_DGRAM, 0)) == -1
|| connect(udp, (struct sockaddr *) &addr, sizeof(addr)) == -1
|| getsockname(udp, (struct sockaddr *) &addr, &addrlen) == -1) {
logit(LOG_WARNING, errno, "Determining local address");
close(udp);
return;
}
close(udp);
us = addr.sin_addr.s_addr;
} else /* query sent to us alone */
us = dst;
#define PUT_ADDR(a) temp_addr = ntohl(a); \
*p++ = temp_addr >> 24; \
*p++ = (temp_addr >> 16) & 0xFF; \
*p++ = (temp_addr >> 8) & 0xFF; \
*p++ = temp_addr & 0xFF;
p = (u_char *) (send_buf + MIN_IP_HEADER_LEN + IGMP_MINLEN);
datalen = 0;
for (vifi = 0, v = uvifs; vifi < numvifs; vifi++, v++) {
if (v->uv_flags & VIFF_DISABLED)
continue;
ncount = 0;
for (la = v->uv_neighbors; la; la = la->al_next) {
/* Make sure that there's room for this neighbor... */
if (datalen + (ncount == 0 ? 4 + 3 + 4 : 4) > MAX_DVMRP_DATA_LEN) {
send_igmp(us, them, IGMP_DVMRP, DVMRP_NEIGHBORS,
htonl(MROUTED_LEVEL), datalen);
p = (u_char *) (send_buf + MIN_IP_HEADER_LEN + IGMP_MINLEN);
datalen = 0;
ncount = 0;
}
/* Put out the header for this neighbor list... */
if (ncount == 0) {
PUT_ADDR(v->uv_lcl_addr);
*p++ = v->uv_metric;
*p++ = v->uv_threshold;
ncount = p;
*p++ = 0;
datalen += 4 + 3;
}
PUT_ADDR(la->al_addr);
datalen += 4;
(*ncount)++;
}
}
if (datalen != 0)
send_igmp(us, them, IGMP_DVMRP, DVMRP_NEIGHBORS, htonl(MROUTED_LEVEL),
datalen);
}
/*
* Send a list of all of our neighbors to the requestor, `src'.
*/
void
accept_neighbor_request2(u_int32_t src, u_int32_t dst)
{
vifi_t vifi;
struct uvif *v;
u_char *p, *ncount;
struct listaddr *la;
int datalen;
u_int32_t us, them = src;
/* Determine which of our addresses to use as the source of our response
* to this query.
*/
if (IN_MULTICAST(ntohl(dst))) { /* query sent to a multicast group */
int udp; /* find best interface to reply on */
struct sockaddr_in addr;
int addrlen = sizeof(addr);
memset(&addr, 0, sizeof addr);
addr.sin_family = AF_INET;
addr.sin_len = sizeof addr;
addr.sin_addr.s_addr = dst;
addr.sin_port = htons(2000); /* any port over 1024 will do... */
if ((udp = socket(AF_INET, SOCK_DGRAM, 0)) == -1
|| connect(udp, (struct sockaddr *) &addr, sizeof(addr)) == -1
|| getsockname(udp, (struct sockaddr *) &addr, &addrlen) == -1) {
logit(LOG_WARNING, errno, "Determining local address");
close(udp);
return;
}
close(udp);
us = addr.sin_addr.s_addr;
} else /* query sent to us alone */
us = dst;
p = (u_char *) (send_buf + MIN_IP_HEADER_LEN + IGMP_MINLEN);
datalen = 0;
for (vifi = 0, v = uvifs; vifi < numvifs; vifi++, v++) {
u_short vflags = v->uv_flags;
u_char rflags = 0;
if (vflags & VIFF_TUNNEL)
rflags |= DVMRP_NF_TUNNEL;
if (vflags & VIFF_SRCRT)
rflags |= DVMRP_NF_SRCRT;
if (vflags & VIFF_DOWN)
rflags |= DVMRP_NF_DOWN;
if (vflags & VIFF_DISABLED)
rflags |= DVMRP_NF_DISABLED;
if (vflags & VIFF_QUERIER)
rflags |= DVMRP_NF_QUERIER;
if (vflags & VIFF_LEAF)
rflags |= DVMRP_NF_LEAF;
ncount = 0;
la = v->uv_neighbors;
if (la == NULL) {
/*
* include down & disabled interfaces and interfaces on
* leaf nets.
*/
if (rflags & DVMRP_NF_TUNNEL)
rflags |= DVMRP_NF_DOWN;
if (datalen > MAX_DVMRP_DATA_LEN - 12) {
send_igmp(us, them, IGMP_DVMRP, DVMRP_NEIGHBORS2,
htonl(MROUTED_LEVEL), datalen);
p = (u_char *) (send_buf + MIN_IP_HEADER_LEN + IGMP_MINLEN);
datalen = 0;
}
*(u_int*)p = v->uv_lcl_addr;
p += 4;
*p++ = v->uv_metric;
*p++ = v->uv_threshold;
*p++ = rflags;
*p++ = 1;
*(u_int*)p = v->uv_rmt_addr;
p += 4;
datalen += 12;
} else {
for ( ; la; la = la->al_next) {
/* Make sure that there's room for this neighbor... */
if (datalen + (ncount == 0 ? 4+4+4 : 4) > MAX_DVMRP_DATA_LEN) {
send_igmp(us, them, IGMP_DVMRP, DVMRP_NEIGHBORS2,
htonl(MROUTED_LEVEL), datalen);
p = (u_char *) (send_buf + MIN_IP_HEADER_LEN + IGMP_MINLEN);
datalen = 0;
ncount = 0;
}
/* Put out the header for this neighbor list... */
if (ncount == 0) {
*(u_int*)p = v->uv_lcl_addr;
p += 4;
*p++ = v->uv_metric;
*p++ = v->uv_threshold;
*p++ = rflags;
ncount = p;
*p++ = 0;
datalen += 4 + 4;
}
*(u_int*)p = la->al_addr;
p += 4;
datalen += 4;
(*ncount)++;
}
}
}
if (datalen != 0)
send_igmp(us, them, IGMP_DVMRP, DVMRP_NEIGHBORS2, htonl(MROUTED_LEVEL),
datalen);
}
void
accept_info_request(u_int32_t src, u_int32_t dst, u_char *p, int datalen)
{
u_char *q;
int len;
int outlen = 0;
q = (u_char *) (send_buf + MIN_IP_HEADER_LEN + IGMP_MINLEN);
/* To be general, this must deal properly with breaking up over-sized
* packets. That implies passing a length to each function, and
* allowing each function to request to be called again. Right now,
* we're only implementing the one thing we are positive will fit into
* a single packet, so we wimp out.
*/
while (datalen > 0) {
len = 0;
switch (*p) {
case DVMRP_INFO_VERSION:
len = info_version(q, (u_char *)send_buf + RECV_BUF_SIZE - q);
break;
case DVMRP_INFO_NEIGHBORS:
default:
logit(LOG_INFO, 0, "ignoring unknown info type %d", *p);
break;
}
*(q+1) = len++;
outlen += len * 4;
q += len * 4;
len = (*(p+1) + 1) * 4;
p += len;
datalen -= len;
}
if (outlen != 0)
send_igmp(INADDR_ANY, src, IGMP_DVMRP, DVMRP_INFO_REPLY,
htonl(MROUTED_LEVEL), outlen);
}
/*
* Information response -- return version string
*/
static int
info_version(char *p, int len)
{
extern char versionstring[];
if (len < 5)
return (0);
*p++ = DVMRP_INFO_VERSION;
p++; /* skip over length */
*p++ = 0; /* zero out */
*p++ = 0; /* reserved fields */
strlcpy(p, versionstring, len - 4);
len = strlen(p);
return ((len + 3) / 4);
}
/*
* Process an incoming neighbor-list message.
*/
void
accept_neighbors(u_int32_t src, u_int32_t dst, u_char *p, int datalen,
u_int32_t level)
{
logit(LOG_INFO, 0, "ignoring spurious DVMRP neighbor list from %s to %s",
inet_fmt(src, s1), inet_fmt(dst, s2));
}
/*
* Process an incoming neighbor-list message.
*/
void
accept_neighbors2(u_int32_t src, u_int32_t dst, u_char *p, int datalen,
u_int32_t level)
{
logit(LOG_INFO, 0, "ignoring spurious DVMRP neighbor list2 from %s to %s",
inet_fmt(src, s1), inet_fmt(dst, s2));
}
/*
* Process an incoming info reply message.
*/
void
accept_info_reply(u_int32_t src, u_int32_t dst, u_char *p, int datalen)
{
logit(LOG_INFO, 0, "ignoring spurious DVMRP info reply from %s to %s",
inet_fmt(src, s1), inet_fmt(dst, s2));
}
/*
* Update the neighbor entry for neighbor 'addr' on vif 'vifi'.
* 'msgtype' is the type of DVMRP message received from the neighbor.
* Return TRUE if 'addr' is a valid neighbor, FALSE otherwise.
*/
int
update_neighbor(vifi_t vifi, u_int32_t addr, int msgtype, char *p,
int datalen, u_int32_t level)
{
struct uvif *v;
struct listaddr *n;
u_int32_t genid = 0;
u_int32_t router;
u_int32_t send_tables = 0;
int do_reset = FALSE;
int nflags;
v = &uvifs[vifi];
nflags = (level >> 16) & 0xff;
/*
* Confirm that 'addr' is a valid neighbor address on vif 'vifi'.
* IT IS ASSUMED that this was preceded by a call to find_vif(), which
* checks that 'addr' is either a valid remote tunnel endpoint or a
* non-broadcast address belonging to a directly-connected subnet.
* Therefore, here we check only that 'addr' is not our own address
* (due to an impostor or erroneous loopback) or an address of the form
* {subnet,0} ("the unknown host"). These checks are not performed in
* find_vif() because those types of address are acceptable for some
* types of IGMP message (such as group membership reports).