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Oh GACK! src-clean doesn't quite work that easily since cleandist rebuilds the
[unix-history] / sbin / mrouted / vif.c
/*
* 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.
*
*
* $Id: vif.c,v 1.5 1993/06/24 05:11:16 deering Exp $
*/
#include "defs.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 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. */
/*
* Forward declarations.
*/
static void start_vif();
static void stop_vif();
/*
* Initialize the virtual interfaces.
*/
void init_vifs()
{
vifi_t vifi;
struct uvif *v;
int enabled_vifs, enabled_phyints;
numvifs = 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)) < 0)
log(LOG_ERR, errno, "UDP socket");
config_vifs_from_kernel();
config_vifs_from_file();
/*
* Quit if there are fewer than two enabled vifs.
*/
enabled_vifs = 0;
enabled_phyints = 0;
for (vifi = 0, v = uvifs; vifi < numvifs; ++vifi, ++v) {
if (!(v->uv_flags & VIFF_DISABLED)) {
++enabled_vifs;
if (!(v->uv_flags & VIFF_TUNNEL))
++enabled_phyints;
}
}
if (enabled_vifs < 2)
log(LOG_ERR, 0, "can't forward: %s",
enabled_vifs == 0 ? "no enabled vifs" : "only one enabled vif");
if (enabled_phyints == 0)
log(LOG_WARNING, 0,
"no enabled interfaces, forwarding via tunnels only");
/*
* Start routing on all virtual interfaces that are not down or
* administratively disabled.
*/
for (vifi = 0, v = uvifs; vifi < numvifs; ++vifi, ++v) {
if (!(v->uv_flags & VIFF_DISABLED)) {
if (!(v->uv_flags & VIFF_DOWN))
start_vif(vifi);
else log(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()
{
register vifi_t vifi;
register 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) < 0)
log(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);
log(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;
log(LOG_INFO, 0,
"%s has gone down; vif #%u taken out of service",
v->uv_name, vifi);
vifs_down = TRUE;
}
}
}
}
/*
* Start routing on the specified virtual interface.
*/
static void start_vif(vifi)
vifi_t vifi;
{
struct uvif *v;
u_long src, dst;
v = &uvifs[vifi];
src = v->uv_lcl_addr;
dst = (v->uv_flags & VIFF_TUNNEL) ? v->uv_rmt_addr : dvmrp_group;
/*
* Install the interface in the kernel's vif structure.
*/
k_add_vif(vifi, &uvifs[vifi]);
/*
* 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);
/*
* 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);
/*
* 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, 0, 0, 0);
}
/*
* Send a probe via the new vif to look for neighbors.
*/
send_igmp(src, dst, IGMP_DVMRP, DVMRP_PROBE, htonl(MROUTED_LEVEL), 0);
}
/*
* Stop routing on the specified virtual interface.
*/
static void stop_vif(vifi)
vifi_t vifi;
{
struct uvif *v;
struct listaddr *a;
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);
/*
* 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);
/*
* 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.
*/
while (v->uv_neighbors != NULL) {
a = v->uv_neighbors;
v->uv_neighbors = a->al_next;
free((char *)a);
}
}
/*
* Find the virtual interface from which an incoming packet arrived,
* based on the packet's source and destination IP addresses.
*/
vifi_t find_vif(src, dst)
register u_long src;
register u_long dst;
{
register vifi_t vifi;
register struct uvif *v;
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 &&
src != v->uv_subnetbcast)
return(vifi);
}
}
}
return (NO_VIF);
}
/*
* Send group membership queries to all subnets for which I am querier.
*/
void query_groups()
{
register vifi_t vifi;
register 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, 0, 0, 0);
}
}
}
/*
* Process an incoming group membership report.
*/
void accept_group_report(src, dst, group)
u_long src, dst, group;
{
register vifi_t vifi;
register struct uvif *v;
register struct listaddr *g;
if ((vifi = find_vif(src, dst)) == NO_VIF ||
(uvifs[vifi].uv_flags & VIFF_TUNNEL)) {
log(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) {
g->al_timer = 0;
break;
}
}
/*
* If not found, add it to the list and tell the kernel.
*/
if (g == NULL) {
g = (struct listaddr *)malloc(sizeof(struct listaddr));
if (g == NULL)
log(LOG_ERR, 0, "ran out of memory"); /* fatal */
g->al_addr = group;
g->al_timer = 0;
g->al_next = v->uv_groups;
v->uv_groups = g;
k_add_group(vifi, group);
}
}
/*
* Send a probe on all vifs from which no neighbors have been heard recently.
*/
void probe_for_neighbors()
{
register vifi_t vifi;
register struct uvif *v;
for (vifi = 0, v = uvifs; vifi < numvifs; vifi++, v++) {
if (!(v->uv_flags & (VIFF_DOWN|VIFF_DISABLED)) &&
v->uv_neighbors == NULL) {
send_igmp(v->uv_lcl_addr,
(v->uv_flags & VIFF_TUNNEL) ? v->uv_rmt_addr
: dvmrp_group,
IGMP_DVMRP, DVMRP_PROBE, htonl(MROUTED_LEVEL), 0);
}
}
}
/*
* Send a list of all of our neighbors to the requestor, `src'.
*/
void accept_neighbor_request(src, dst)
u_long src, dst;
{
vifi_t vifi;
struct uvif *v;
u_char *p, *ncount;
struct listaddr *la;
int datalen;
u_long 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);
addr.sin_family = AF_INET;
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)) < 0
|| connect(udp, (struct sockaddr *) &addr, sizeof(addr)) < 0
|| getsockname(udp, (struct sockaddr *) &addr, &addrlen) < 0) {
log(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(src, dst)
u_long src, dst;
{
vifi_t vifi;
struct uvif *v;
u_char *p, *ncount;
struct listaddr *la;
int datalen;
u_long 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);
addr.sin_family = AF_INET;
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)) < 0
|| connect(udp, (struct sockaddr *) &addr, sizeof(addr)) < 0
|| getsockname(udp, (struct sockaddr *) &addr, &addrlen) < 0) {
log(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++) {
register u_short vflags = v->uv_flags;
register 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;
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);
}
/*
* Process an incoming neighbor-list message.
*/
void accept_neighbors(src, dst, p, datalen, level)
u_long src, dst, level;
char *p;
int datalen;
{
log(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(src, dst, p, datalen, level)
u_long src, dst, level;
char *p;
int datalen;
{
log(LOG_INFO, 0, "ignoring spurious DVMRP neighbor list2 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, addr, msgtype)
vifi_t vifi;
u_long addr;
int msgtype;
{
register struct uvif *v;
register struct listaddr *n;
v = &uvifs[vifi];
/*
* 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).
*/
if (!(v->uv_flags & VIFF_TUNNEL) &&
(addr == v->uv_lcl_addr ||
addr == v->uv_subnet )) {
log(LOG_WARNING, 0,
"received DVMRP message from 'the unknown host' or self: %s",
inet_fmt(addr, s1));
return (FALSE);
}
/*
* If we have received a route report from a neighbor, and we believed
* that we had no neighbors on this vif, send a full route report to
* all neighbors on the vif.
*/
if (msgtype == DVMRP_REPORT && v->uv_neighbors == NULL)
report(ALL_ROUTES, vifi,
(v->uv_flags & VIFF_TUNNEL) ? addr : dvmrp_group);
/*
* Look for addr in list of neighbors; if found, reset its timer.
*/
for (n = v->uv_neighbors; n != NULL; n = n->al_next) {
if (addr == n->al_addr) {
n->al_timer = 0;
break;
}
}
/*
* If not found, add it to the list. If the neighbor has a lower
* IP address than me, yield querier duties to it.
*/
if (n == NULL) {
n = (struct listaddr *)malloc(sizeof(struct listaddr));
if (n == NULL)
log(LOG_ERR, 0, "ran out of memory"); /* fatal */
n->al_addr = addr;
n->al_timer = 0;
n->al_next = v->uv_neighbors;
v->uv_neighbors = n;
if (!(v->uv_flags & VIFF_TUNNEL) &&
ntohl(addr) < ntohl(v->uv_lcl_addr))
v->uv_flags &= ~VIFF_QUERIER;
}
return (TRUE);
}
/*
* On every timer interrupt, advance the timer in each neighbor and
* group entry on every vif.
*/
void age_vifs()
{
register vifi_t vifi;
register struct uvif *v;
register struct listaddr *a, *prev_a, *n;
register u_long addr;
for (vifi = 0, v = uvifs; vifi < numvifs; ++vifi, ++v ) {
for (prev_a = (struct listaddr *)&(v->uv_neighbors),
a = v->uv_neighbors;
a != NULL;
prev_a = a, a = a->al_next) {
if ((a->al_timer += TIMER_INTERVAL) < NEIGHBOR_EXPIRE_TIME)
continue;
/*
* Neighbor has expired; delete it from the neighbor list,
* delete it from the 'dominants' and 'subordinates arrays of
* any route entries and assume querier duties unless there is
* another neighbor with a lower IP address than mine.
*/
addr = a->al_addr;
prev_a->al_next = a->al_next;
free((char *)a);
a = prev_a;
delete_neighbor_from_routes(addr, vifi);
if (!(v->uv_flags & VIFF_TUNNEL)) {
v->uv_flags |= VIFF_QUERIER;
for (n = v->uv_neighbors; n != NULL; n = n->al_next) {
if (ntohl(n->al_addr) < ntohl(v->uv_lcl_addr)) {
v->uv_flags &= ~VIFF_QUERIER;
break;
}
}
}
}
for (prev_a = (struct listaddr *)&(v->uv_groups),
a = v->uv_groups;
a != NULL;
prev_a = a, a = a->al_next) {
if ((a->al_timer += TIMER_INTERVAL) < GROUP_EXPIRE_TIME)
continue;
/*
* Group has expired; tell kernel and delete from group list.
*/
k_del_group(vifi, a->al_addr);
prev_a->al_next = a->al_next;
free((char *)a);
a = prev_a;
}
}
}
/*
* Print the contents of the uvifs array on file 'fp'.
*/
void dump_vifs(fp)
FILE *fp;
{
register vifi_t vifi;
register struct uvif *v;
register struct listaddr *a;
fprintf(fp,
"\nVirtual Interface Table\n%s",
" Vif Local-Address Metric Thresh Flags\n");
for (vifi = 0, v = uvifs; vifi < numvifs; vifi++, v++) {
fprintf(fp, " %2u %-15s %6s: %-15s %4u %7u ",
vifi,
inet_fmt(v->uv_lcl_addr, s1),
(v->uv_flags & VIFF_TUNNEL) ?
"tunnel":
"subnet",
(v->uv_flags & VIFF_TUNNEL) ?
inet_fmt(v->uv_rmt_addr, s2) :
inet_fmts(v->uv_subnet, v->uv_subnetmask, s3),
v->uv_metric,
v->uv_threshold);
if (v->uv_flags & VIFF_DOWN) fprintf(fp, " down");
if (v->uv_flags & VIFF_DISABLED) fprintf(fp, " disabled");
if (v->uv_flags & VIFF_QUERIER) fprintf(fp, " querier");
if (v->uv_flags & VIFF_SRCRT) fprintf(fp, " src-rt");
fprintf(fp, "\n");
if (v->uv_neighbors != NULL) {
fprintf(fp, " peers : %-15s\n",
inet_fmt(v->uv_neighbors->al_addr, s1));
for (a = v->uv_neighbors->al_next; a != NULL; a = a->al_next) {
fprintf(fp, " %-15s\n",
inet_fmt(a->al_addr, s1));
}
}
if (v->uv_groups != NULL) {
fprintf(fp, " groups: %-15s\n",
inet_fmt(v->uv_groups->al_addr, s1));
for (a = v->uv_groups->al_next; a != NULL; a = a->al_next) {
fprintf(fp, " %-15s\n",
inet_fmt(a->al_addr, s1));
}
}
}
fprintf(fp, "\n");
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.