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pim_proto.c
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pim_proto.c
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/*
* Copyright (c) 1998-2001
* University of Southern California/Information Sciences Institute.
* All rights reserved.
*
* 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.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT 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 PROJECT 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.
*/
/*
* $Id: pim_proto.c,v 1.47 2003/05/28 22:57:16 pavlin Exp $
*/
#include <arpa/inet.h>
#include "defs.h"
typedef struct {
uint16_t holdtime;
uint32_t dr_prio;
int8_t dr_prio_present;
uint32_t genid;
} pim_hello_opts_t;
/*
* Local functions definitions.
*/
static int restart_dr_election (struct uvif *v);
static int parse_pim_hello (char *msg, size_t len, uint32_t src, pim_hello_opts_t *opts);
static void cache_nbr_settings (pim_nbr_entry_t *nbr, pim_hello_opts_t *opts);
static int send_pim_register_stop (uint32_t reg_src, uint32_t reg_dst, uint32_t inner_grp, uint32_t inner_source);
static build_jp_message_t *get_jp_working_buff (void);
static void return_jp_working_buff (pim_nbr_entry_t *pim_nbr);
static void pack_jp_message_grp (pim_nbr_entry_t *pim_nbr);
static void pack_jp_message_rp (pim_nbr_entry_t *pim_nbr);
static void send_jp_message (pim_nbr_entry_t *pim_nbr);
static int compare_metrics (uint32_t local_preference,
uint32_t local_metric,
uint32_t local_address,
uint32_t remote_preference,
uint32_t remote_metric,
uint32_t remote_address);
build_jp_message_t *build_jp_message_pool;
int build_jp_message_pool_counter;
/************************************************************************
* PIM_HELLO
************************************************************************/
int receive_pim_hello(uint32_t src, uint32_t dst __attribute__((unused)), char *msg, size_t len)
{
vifi_t vifi;
struct uvif *v;
size_t bsr_length;
pim_nbr_entry_t *nbr, *prev_nbr, *new_nbr;
pim_hello_opts_t opts;
srcentry_t *srcentry;
mrtentry_t *mrtentry;
if (inet_cksum((uint16_t *)msg, len))
return FALSE;
vifi = find_vif_direct(src);
if (vifi == NO_VIF) {
/* Either a local vif or somehow received PIM_HELLO from
* non-directly connected router. Ignore it. */
if (local_address(src) == NO_VIF)
logit(LOG_DEBUG, 0, "Ignoring PIM_HELLO from non-neighbor router %s",
inet_fmt(src, s1, sizeof(s1)));
return FALSE;
}
v = &uvifs[vifi];
if (v->uv_flags & (VIFF_DOWN | VIFF_DISABLED | VIFF_REGISTER))
return FALSE; /* Shoudn't come on this interface */
/* Get the Holdtime (in seconds) and any DR priority from the message. Return if error. */
if (parse_pim_hello(msg, len, src, &opts) == FALSE)
return FALSE;
IF_DEBUG(DEBUG_PIM_HELLO | DEBUG_PIM_TIMER)
logit(LOG_DEBUG, 0, "PIM HELLO holdtime from %s is %u",
inet_fmt(src, s1, sizeof(s1)), opts.holdtime);
IF_DEBUG(DEBUG_PIM_HELLO | DEBUG_PIM_TIMER)
logit(LOG_DEBUG, 0, "PIM DR PRIORITY from %s is %u",
inet_fmt(src, s1, sizeof(s1)), opts.dr_prio);
IF_DEBUG(DEBUG_PIM_HELLO | DEBUG_PIM_TIMER)
logit(LOG_DEBUG, 0, "PIM GenID from %s is %u",
inet_fmt(src, s1, sizeof(s1)), opts.genid);
for (prev_nbr = NULL, nbr = v->uv_pim_neighbors; nbr; prev_nbr = nbr, nbr = nbr->next) {
/* The PIM neighbors are sorted in decreasing order of the
* network addresses (note that to be able to compare them
* correctly we must translate the addresses in host order.
*/
if (ntohl(src) < ntohl(nbr->address))
continue;
if (src == nbr->address) {
/* We already have an entry for this host */
if (0 == opts.holdtime) {
/* Looks like we have a nice neighbor who is going down
* and wants to inform us by sending "holdtime=0". Thanks
* buddy and see you again!
*/
logit(LOG_INFO, 0, "PIM HELLO received: neighbor %s going down",
inet_fmt(src, s1, sizeof(s1)));
delete_pim_nbr(nbr);
return TRUE;
}
/* https://tools.ietf.org/html/draft-ietf-pim-hello-genid-01 */
if (nbr->genid != opts.genid) {
/* Known neighbor rebooted, update info and resend RP-Set */
cache_nbr_settings(nbr, &opts);
goto rebooted;
}
if (nbr->dr_prio != opts.dr_prio) {
/* New DR priority for neighbor, restart DR election */
cache_nbr_settings(nbr, &opts);
goto election;
}
cache_nbr_settings(nbr, &opts);
return TRUE;
}
/* No entry for this neighbor. Exit loop to create an entry for it. */
break;
}
/*
* This is a new neighbor. Create a new entry for it.
* It must be added right after `prev_nbr`
*/
IF_DEBUG(DEBUG_PIM_HELLO | DEBUG_PIM_TIMER)
logit(LOG_INFO, 0, "Received PIM HELLO from new neighbor %s", inet_fmt(src, s1, sizeof(s1)));
new_nbr = calloc(1, sizeof(pim_nbr_entry_t));
if (!new_nbr)
logit(LOG_ERR, 0, "Ran out of memory in receive_pim_hello()");
new_nbr->address = src;
new_nbr->vifi = vifi;
new_nbr->build_jp_message = NULL;
new_nbr->next = nbr;
new_nbr->prev = prev_nbr;
/* Add PIM Hello options */
cache_nbr_settings(new_nbr, &opts);
/* Add to linked list of neighbors */
if (prev_nbr)
prev_nbr->next = new_nbr;
else
v->uv_pim_neighbors = new_nbr;
if (new_nbr->next)
new_nbr->next->prev = new_nbr;
v->uv_flags &= ~VIFF_NONBRS;
v->uv_flags |= VIFF_PIM_NBR;
/* Since a new neighbour has come up, let it know your existence */
/* XXX: TODO: not in the spec,
* but probably should send the message after a short random period?
*/
send_pim_hello(v, pim_timer_hello_holdtime);
rebooted:
if (v->uv_flags & VIFF_DR) {
/*
* If I am the current DR on that interface, so
* send an RP-Set message to the new neighbor.
*/
if ((bsr_length = create_pim_bootstrap_message(pim_send_buf)))
send_pim_unicast(pim_send_buf, v->uv_mtu, v->uv_lcl_addr, src, PIM_BOOTSTRAP, bsr_length);
}
election:
if (restart_dr_election(v)) {
/* I was the DR, but not anymore. Remove all register_vif from
* oif list for all directly connected sources (for vifi). */
/* TODO: XXX: first entry is not used! */
for (srcentry = srclist->next; srcentry; srcentry = srcentry->next) {
/* If not directly connected source for vifi */
if ((srcentry->incoming != vifi) || srcentry->upstream)
continue;
for (mrtentry = srcentry->mrtlink; mrtentry; mrtentry = mrtentry->srcnext) {
if (!(mrtentry->flags & MRTF_SG))
continue; /* This is not (S,G) entry */
/* Remove the register oif */
VIFM_CLR(reg_vif_num, mrtentry->joined_oifs);
change_interfaces(mrtentry,
mrtentry->incoming,
mrtentry->joined_oifs,
mrtentry->pruned_oifs,
mrtentry->leaves,
mrtentry->asserted_oifs, 0);
}
}
}
/*
* TODO: XXX: does a new neighbor change any routing entries info?
* Need to trigger joins?
*/
IF_DEBUG(DEBUG_PIM_HELLO)
dump_vifs(stderr); /* Show we got a new neighbor */
return TRUE;
}
void delete_pim_nbr(pim_nbr_entry_t *nbr_delete)
{
srcentry_t *src;
srcentry_t *src_next;
mrtentry_t *mrt;
mrtentry_t *mrt_srcs;
grpentry_t *grp;
cand_rp_t *cand_rp;
rp_grp_entry_t *rp_grp;
rpentry_t *rp;
struct uvif *v;
IF_DEBUG(DEBUG_PIM_HELLO | DEBUG_PIM_TIMER)
logit(LOG_INFO, 0, "Deleting PIM neighbor %s", inet_fmt(nbr_delete->address, s1, sizeof(s1)));
v = &uvifs[nbr_delete->vifi];
/* Delete the entry from the pim_nbrs chain */
if (nbr_delete->prev)
nbr_delete->prev->next = nbr_delete->next;
else
v->uv_pim_neighbors = nbr_delete->next;
if (nbr_delete->next)
nbr_delete->next->prev = nbr_delete->prev;
return_jp_working_buff(nbr_delete);
/* That neighbor could've been the DR */
restart_dr_election(v);
/* Update the source entries */
for (src = srclist; src; src = src_next) {
src_next = src->next;
if (src->upstream != nbr_delete)
continue;
/* Reset the next hop (PIM) router */
if (set_incoming(src, PIM_IIF_SOURCE) == FALSE) {
/* Coudn't reset it. Sorry, the hext hop router toward that
* source is probably not a PIM router, or cannot find route
* at all, hence I cannot handle this source and have to
* delete it.
*/
logit(LOG_WARNING, 0, "Delete source entry for source %s", inet_fmt(src->address, s1, sizeof(s1)));
delete_srcentry(src);
} else if (src->upstream) {
/* Ignore the local or directly connected sources */
/* Browse all MRT entries for this source and reset the
* upstream router. Note that the upstream router is not always
* toward the source: it could be toward the RP for example.
*/
for (mrt = src->mrtlink; mrt; mrt = mrt->srcnext) {
if (!(mrt->flags & MRTF_RP)) {
mrt->upstream = src->upstream;
mrt->metric = src->metric;
mrt->preference = src->preference;
change_interfaces(mrt, src->incoming,
mrt->joined_oifs,
mrt->pruned_oifs,
mrt->leaves,
mrt->asserted_oifs, 0);
}
}
}
}
/* Update the RP entries */
for (cand_rp = cand_rp_list; cand_rp; cand_rp = cand_rp->next) {
if (cand_rp->rpentry->upstream != nbr_delete)
continue;
rp = cand_rp->rpentry;
/* Reset the RP entry iif
* TODO: check if error setting the iif! */
if (local_address(rp->address) == NO_VIF) {
set_incoming(rp, PIM_IIF_RP);
} else {
rp->incoming = reg_vif_num;
rp->upstream = NULL;
}
mrt = rp->mrtlink;
if (mrt) {
mrt->upstream = rp->upstream;
mrt->metric = rp->metric;
mrt->preference = rp->preference;
change_interfaces(mrt,
rp->incoming,
mrt->joined_oifs,
mrt->pruned_oifs,
mrt->leaves,
mrt->asserted_oifs, 0);
}
/* Update the group entries for this RP */
for (rp_grp = cand_rp->rp_grp_next; rp_grp; rp_grp = rp_grp->rp_grp_next) {
for (grp = rp_grp->grplink; grp; grp = grp->rpnext) {
mrt = grp->grp_route;
if (mrt) {
mrt->upstream = rp->upstream;
mrt->metric = rp->metric;
mrt->preference = rp->preference;
change_interfaces(mrt,
rp->incoming,
mrt->joined_oifs,
mrt->pruned_oifs,
mrt->leaves,
mrt->asserted_oifs, 0);
}
/* Update only the (S,G)RPbit entries for this group */
for (mrt_srcs = grp->mrtlink; mrt_srcs; mrt_srcs = mrt_srcs->grpnext) {
if (mrt_srcs->flags & MRTF_RP) {
mrt_srcs->upstream = rp->upstream;
mrt_srcs->metric = rp->metric;
mrt_srcs->preference = rp->preference;
change_interfaces(mrt_srcs,
rp->incoming,
mrt_srcs->joined_oifs,
mrt_srcs->pruned_oifs,
mrt_srcs->leaves,
mrt_srcs->asserted_oifs, 0);
}
}
}
}
}
/* Fix GitHub issue #22: Crash in (S,G) state when neighbor is lost */
for (cand_rp = cand_rp_list; cand_rp; cand_rp = cand_rp->next) {
for (rp_grp = cand_rp->rp_grp_next; rp_grp; rp_grp = rp_grp->rp_grp_next) {
for (grp = rp_grp->grplink; grp; grp = grp->next) {
mrt = grp->grp_route;
if (mrt && mrt->upstream) {
if (mrt->upstream == nbr_delete)
mrt->upstream = NULL;
}
}
}
}
free(nbr_delete);
}
/*
* If all PIM routers on a network segment support DR-Priority we use
* that to elect the DR, and use the highest IP address as the tie
* breaker. If any routers does *not* support DR-Priority all routers
* must use the IP address to elect the DR, this for backwards compat.
*
* Returns TRUE if we lost the DR role, elected another router.
*/
static int restart_dr_election(struct uvif *v)
{
int was_dr = 0, use_dr_prio = 1;
uint32_t best_dr_prio = 0;
pim_nbr_entry_t *nbr;
if (v->uv_flags & VIFF_DR)
was_dr = 1;
if (!v->uv_pim_neighbors) {
/* This was our last neighbor, now we're it. */
IF_DEBUG(DEBUG_PIM_HELLO | DEBUG_PIM_TIMER)
logit(LOG_DEBUG, 0, "All neighbor PIM routers on %s lost, we are the DR now.",
inet_fmt(v->uv_lcl_addr, s1, sizeof(s1)));
v->uv_flags &= ~VIFF_PIM_NBR;
v->uv_flags |= (VIFF_NONBRS | VIFF_DR);
return FALSE;
}
/* Check if all routers on segment advertise DR Priority option
* in their PIM Hello messages. Figure out highest prio. */
for (nbr = v->uv_pim_neighbors; nbr; nbr = nbr->next) {
if (!nbr->dr_prio_present) {
use_dr_prio = 0;
break;
}
if (nbr->dr_prio > best_dr_prio)
best_dr_prio = nbr->dr_prio;
}
/*
* RFC4601 sec. 4.3.2
*/
if (use_dr_prio) {
IF_DEBUG(DEBUG_PIM_HELLO | DEBUG_PIM_TIMER)
logit(LOG_DEBUG, 0, "All routers in %s segment support DR Priority based DR election.",
inet_fmt(v->uv_lcl_addr, s1, sizeof(s1)));
if (best_dr_prio < v->uv_dr_prio) {
v->uv_flags |= VIFF_DR;
return FALSE;
}
if (best_dr_prio == v->uv_dr_prio)
goto tiebreak;
} else {
tiebreak:
IF_DEBUG(DEBUG_PIM_HELLO | DEBUG_PIM_TIMER)
logit(LOG_DEBUG, 0, "Using fallback DR election on %s.",
inet_fmt(v->uv_lcl_addr, s1, sizeof(s1)));
if (ntohl(v->uv_lcl_addr) > ntohl(v->uv_pim_neighbors->address)) {
/* The first address is the new potential remote
* DR address, but the local address is the winner. */
v->uv_flags |= VIFF_DR;
return FALSE;
}
}
if (was_dr) {
IF_DEBUG(DEBUG_PIM_HELLO | DEBUG_PIM_TIMER)
logit(LOG_INFO, 0, "We lost DR role on %s in election.",
inet_fmt(v->uv_lcl_addr, s1, sizeof(s1)));
v->uv_flags &= ~VIFF_DR;
return TRUE; /* Lost election, clean up. */
}
return FALSE;
}
static int validate_pim_opt(uint32_t src, char *str, uint16_t len, uint16_t opt_len)
{
if (len != opt_len) {
IF_DEBUG(DEBUG_PIM_HELLO | DEBUG_PIM_TIMER)
logit(LOG_DEBUG, 0, "PIM HELLO %s from %s: invalid OptionLength = %u",
str, inet_fmt(src, s1, sizeof(s1)), opt_len);
return FALSE;
}
return TRUE;
}
static int parse_pim_hello(char *msg, size_t len, uint32_t src, pim_hello_opts_t *opts)
{
int result = FALSE;
size_t rec_len;
uint8_t *data;
uint16_t opt_type;
uint16_t opt_len;
/* Assume no opts. */
memset(opts, 0, sizeof(*opts));
/* Body of PIM message */
msg += sizeof(pim_header_t);
/* Ignore any data if shorter than (pim_hello header) */
for (len -= sizeof(pim_header_t); len >= sizeof(pim_hello_t); len -= rec_len) {
data = (uint8_t *)msg;
GET_HOSTSHORT(opt_type, data);
GET_HOSTSHORT(opt_len, data);
switch (opt_type) {
case PIM_HELLO_HOLDTIME:
result = validate_pim_opt(src, "Holdtime", PIM_HELLO_HOLDTIME_LEN, opt_len);
if (TRUE == result)
GET_HOSTSHORT(opts->holdtime, data);
break;
case PIM_HELLO_DR_PRIO:
result = validate_pim_opt(src, "DR Priority", PIM_HELLO_DR_PRIO_LEN, opt_len);
if (TRUE == result) {
opts->dr_prio_present = 1;
GET_HOSTLONG(opts->dr_prio, data);
}
break;
case PIM_HELLO_GENID:
result = validate_pim_opt(src, "GenID", PIM_HELLO_GENID_LEN, opt_len);
if (TRUE == result)
GET_HOSTLONG(opts->genid, data);
break;
default:
break; /* Ignore any unknown options */
}
/* Move to the next option */
rec_len = (sizeof(pim_hello_t) + opt_len);
if (len < rec_len || result == FALSE)
return FALSE;
msg += rec_len;
}
return result;
}
static void cache_nbr_settings(pim_nbr_entry_t *nbr, pim_hello_opts_t *opts)
{
SET_TIMER(nbr->timer, opts->holdtime);
nbr->genid = opts->genid;
nbr->dr_prio = opts->dr_prio;
nbr->dr_prio_present = opts->dr_prio_present;
}
int send_pim_hello(struct uvif *v, uint16_t holdtime)
{
char *buf;
uint8_t *data;
size_t len;
buf = pim_send_buf + sizeof(struct ip) + sizeof(pim_header_t);
data = (uint8_t *)buf;
PUT_HOSTSHORT(PIM_HELLO_HOLDTIME, data);
PUT_HOSTSHORT(PIM_HELLO_HOLDTIME_LEN, data);
PUT_HOSTSHORT(holdtime, data);
PUT_HOSTSHORT(PIM_HELLO_DR_PRIO, data);
PUT_HOSTSHORT(PIM_HELLO_DR_PRIO_LEN, data);
PUT_HOSTLONG(v->uv_dr_prio, data);
#ifdef ENABLE_PIM_HELLO_GENID
PUT_HOSTSHORT(PIM_HELLO_GENID, data);
PUT_HOSTSHORT(PIM_HELLO_GENID_LEN, data);
PUT_HOSTLONG(v->uv_genid, data);
#endif
len = data - (uint8_t *)buf;
send_pim(pim_send_buf, v->uv_lcl_addr, allpimrouters_group, PIM_HELLO, len);
SET_TIMER(v->uv_hello_timer, pim_timer_hello_interval);
return TRUE;
}
/************************************************************************
* PIM_REGISTER
************************************************************************/
/* TODO: XXX: IF THE BORDER BIT IS SET, THEN
* FORWARD THE WHOLE PACKET FROM USER SPACE
* AND AT THE SAME TIME IGNORE ANY CACHE_MISS
* SIGNALS FROM THE KERNEL.
*/
int receive_pim_register(uint32_t reg_src, uint32_t reg_dst, char *msg, size_t len)
{
uint32_t inner_src, inner_grp;
pim_register_t *reg;
struct ip *ip;
uint32_t is_border, is_null;
mrtentry_t *mrtentry;
mrtentry_t *mrtentry2;
vifbitmap_t oifs;
/*
* If instance specific multicast routing table is in use, check
* that we are the target of the register packet. Otherwise we
* might end up responding to register packet belonging to another
* pimd instance. If we are not an RP candidate, we shouldn't have
* pimreg interface and shouldn't receive register packets, but we'll
* check the cand_rp flag anyway, just to be on the safe side.
*/
if (mrt_table_id != 0) {
if (!cand_rp_flag || my_cand_rp_address != reg_dst) {
IF_DEBUG(DEBUG_PIM_REGISTER)
logit(LOG_DEBUG, 0, "PIM register: packet from %s to %s is not destined for us",
inet_fmt(reg_src, s1, sizeof(s1)), inet_fmt(reg_dst, s2, sizeof(s2)));
return FALSE;
}
}
IF_DEBUG(DEBUG_PIM_REGISTER)
logit(LOG_INFO, 0, "Received PIM register: len = %d from %s",
len, inet_fmt(reg_src, s1, sizeof(s1)));
/*
* Message length validation.
* This is suppose to be done in the kernel, but some older kernel
* versions do not pefrorm the check for the NULL register messages.
*/
if (len < sizeof(pim_header_t) + sizeof(pim_register_t) + sizeof(struct ip)) {
IF_DEBUG(DEBUG_PIM_REGISTER)
logit(LOG_INFO, 0, "PIM register: short packet (len = %d) from %s",
len, inet_fmt(reg_src, s1, sizeof(s1)));
return FALSE;
}
/*
* XXX: For PIM_REGISTER the checksum does not include
* the inner IP packet. However, some older routers might
* create the checksum over the whole packet. Hence,
* verify the checksum over the first 8 bytes, and if fails,
* then over the whole Register
*/
if ((inet_cksum((uint16_t *)msg, sizeof(pim_header_t) + sizeof(pim_register_t)))
&& (inet_cksum((uint16_t *)msg, len))) {
IF_DEBUG(DEBUG_PIM_REGISTER)
logit(LOG_DEBUG, 0, "PIM REGISTER from DR %s: invalid PIM header checksum",
inet_fmt(reg_src, s1, sizeof(s1)));
return FALSE;
}
/* Lookup register message flags */
reg = (pim_register_t *)(msg + sizeof(pim_header_t));
is_border = ntohl(reg->reg_flags) & PIM_REGISTER_BORDER_BIT;
is_null = ntohl(reg->reg_flags) & PIM_REGISTER_NULL_REGISTER_BIT;
/* initialize the pointer to the encapsulated packet */
ip = (struct ip *)(msg + sizeof(pim_header_t) + sizeof(pim_register_t));
/* check the IP version (especially for the NULL register...see above) */
if (ip->ip_v != IPVERSION && (! is_null)) {
IF_DEBUG(DEBUG_PIM_REGISTER)
logit(LOG_INFO, 0, "PIM register: incorrect IP version (%d) of the inner packet from %s",
ip->ip_v, inet_fmt(reg_src, s1, sizeof(s1)));
return FALSE;
}
/* We are keeping all addresses in network order, so no need for ntohl()*/
inner_src = ip->ip_src.s_addr;
inner_grp = ip->ip_dst.s_addr;
/*
* inner_src and inner_grp must be valid IP unicast and multicast address
* respectively. XXX: not in the spec.
* PIM-SSM support: inner_grp must not be in PIM-SSM range
*/
if ((!inet_valid_host(inner_src)) || (!IN_MULTICAST(ntohl(inner_grp))) || IN_PIM_SSM_RANGE(inner_grp)) {
if (!inet_valid_host(inner_src)) {
logit(LOG_WARNING, 0, "Inner source address of register message by %s is invalid: %s",
inet_fmt(reg_src, s1, sizeof(s1)), inet_fmt(inner_src, s2, sizeof(s2)));
}
if (!IN_MULTICAST(ntohl(inner_grp))) {
logit(LOG_WARNING, 0, "Inner group address of register message by %s is invalid: %s",
inet_fmt(reg_src, s1, sizeof(s1)), inet_fmt(inner_grp, s2, sizeof(s2)));
}
send_pim_register_stop(reg_dst, reg_src, inner_grp, inner_src);
return FALSE;
}
mrtentry = find_route(inner_src, inner_grp, MRTF_SG | MRTF_WC | MRTF_PMBR, DONT_CREATE);
if (!mrtentry) {
/* No routing entry. Send REGISTER_STOP and return. */
IF_DEBUG(DEBUG_PIM_REGISTER)
logit(LOG_DEBUG, 0, "No routing entry for source %s and/or group %s" ,
inet_fmt(inner_src, s1, sizeof(s1)), inet_fmt(inner_grp, s2, sizeof(s2)));
/* TODO: XXX: shouldn't it be inner_src=INADDR_ANY? Not in the spec. */
send_pim_register_stop(reg_dst, reg_src, inner_grp, inner_src);
return TRUE;
}
/* Check if I am the RP for that group */
if ((local_address(reg_dst) == NO_VIF) || !check_mrtentry_rp(mrtentry, reg_dst)) {
IF_DEBUG(DEBUG_PIM_REGISTER)
logit(LOG_DEBUG, 0, "Not RP in address %s", inet_fmt(reg_dst, s1, sizeof(s1)));
send_pim_register_stop(reg_dst, reg_src, inner_grp, inner_src);
return TRUE;
}
/* I am the RP */
if (mrtentry->flags & MRTF_SG) {
/* (S,G) found */
/* TODO: check the timer again */
SET_TIMER(mrtentry->timer, PIM_DATA_TIMEOUT); /* restart timer */
if (!(mrtentry->flags & MRTF_SPT)) { /* The SPT bit is not set */
if (!is_null) {
calc_oifs(mrtentry, &oifs);
if (VIFM_ISEMPTY(oifs) && (mrtentry->incoming == reg_vif_num)) {
IF_DEBUG(DEBUG_PIM_REGISTER)
logit(LOG_DEBUG, 0, "No output intefaces found for group %s source %s",
inet_fmt(inner_grp, s1, sizeof(s1)), inet_fmt(inner_src, s2, sizeof(s2)));
send_pim_register_stop(reg_dst, reg_src, inner_grp, inner_src);
return TRUE;
}
/*
* TODO: XXX: BUG!!!
* The data will be forwarded by the kernel MFC!!!
* Need to set a special flag for this routing entry so after
* a cache miss occur, the multicast packet will be forwarded
* from user space and won't install entry in the kernel MFC.
* The problem is that the kernel MFC doesn't know the
* PMBR address and simply sets the multicast forwarding
* cache to accept/forward all data coming from the
* register_vif.
*/
if (is_border) {
if (mrtentry->pmbr_addr != reg_src) {
IF_DEBUG(DEBUG_PIM_REGISTER)
logit(LOG_DEBUG, 0, "pmbr_addr (%s) != reg_src (%s)",
inet_fmt(mrtentry->pmbr_addr, s1, sizeof(s1)), inet_fmt(reg_src, s2, sizeof(s2)));
send_pim_register_stop(reg_dst, reg_src, inner_grp, inner_src);
return TRUE;
}
}
return TRUE;
}
/* TODO: XXX: if NULL_REGISTER and has (S,G) with SPT=0, then..?*/
return TRUE;
}
else {
/* The SPT bit is set */
IF_DEBUG(DEBUG_PIM_REGISTER)
logit(LOG_DEBUG, 0, "SPT bit is set for group %s source %s",
inet_fmt(inner_grp, s1, sizeof(s1)), inet_fmt(inner_src, s2, sizeof(s2)));
send_pim_register_stop(reg_dst, reg_src, inner_grp, inner_src);
return TRUE;
}
}
if (mrtentry->flags & (MRTF_WC | MRTF_PMBR)) {
if (is_border) {
/* Create (S,G) state. The oifs will be the copied from the
* existing (*,G) or (*,*,RP) entry. */
mrtentry2 = find_route(inner_src, inner_grp, MRTF_SG, CREATE);
if (mrtentry2) {
mrtentry2->pmbr_addr = reg_src;
/* Clear the SPT flag */
mrtentry2->flags &= ~(MRTF_SPT | MRTF_NEW);
SET_TIMER(mrtentry2->timer, PIM_DATA_TIMEOUT);
/* TODO: explicitly call the Join/Prune send function? */
FIRE_TIMER(mrtentry2->jp_timer); /* Send the Join immediately */
/* TODO: explicitly call this function?
send_pim_join_prune(mrtentry2->upstream->vifi,
mrtentry2->upstream,
PIM_JOIN_PRUNE_HOLDTIME);
*/
}
}
}
if (mrtentry->flags & MRTF_WC) {
/* First PIM Register for this routing entry, log it */
logit(LOG_INFO, 0, "Received PIM REGISTER: src %s, group %s",
inet_fmt(reg_src, s1, sizeof(s1)), inet_fmt(inner_grp, s2, sizeof(s2)));
/* (*,G) entry */
calc_oifs(mrtentry, &oifs);
if (VIFM_ISEMPTY(oifs)) {
IF_DEBUG(DEBUG_PIM_REGISTER)
logit(LOG_DEBUG, 0, "No output intefaces found for group %s source %s (*,G)",
inet_fmt(inner_grp, s1, sizeof(s1)), inet_fmt(inner_src, s2, sizeof(s2)));
send_pim_register_stop(reg_dst, reg_src, inner_grp, INADDR_ANY_N);
return FALSE;
} else { /* XXX: TODO: check with the spec again */
if (!is_null) {
uint32_t mfc_source = inner_src;
/* Install cache entry in the kernel */
/* TODO: XXX: probably redundant here, because the
* decapsulated mcast packet in the kernel will
* result in CACHE_MISS
*/
#ifdef KERNEL_MFC_WC_G
if (!(mrtentry->flags & MRTF_MFC_CLONE_SG))
mfc_source = INADDR_ANY_N;
#endif /* KERNEL_MFC_WC_G */
add_kernel_cache(mrtentry, mfc_source, inner_grp, 0);
k_chg_mfc(igmp_socket, mfc_source, inner_grp,
mrtentry->incoming, mrtentry->oifs,
mrtentry->group->rpaddr);
return TRUE;
}
}
return TRUE;
}
if (mrtentry->flags & MRTF_PMBR) {
/* (*,*,RP) entry */
if (!is_null) {
uint32_t mfc_source = inner_src;
/* XXX: have to create either (S,G) or (*,G).
* The choice below is (*,G)
*/
mrtentry2 = find_route(INADDR_ANY_N, inner_grp, MRTF_WC, CREATE);
if (!mrtentry2)
return FALSE;
if (mrtentry2->flags & MRTF_NEW) {
/* TODO: something else? Have the feeling sth is missing */
mrtentry2->flags &= ~MRTF_NEW;
/* TODO: XXX: copy the timer from the (*,*,RP) entry? */
COPY_TIMER(mrtentry->timer, mrtentry2->timer);
}
/* Install cache entry in the kernel */
#ifdef KERNEL_MFC_WC_G
if (!(mrtentry->flags & MRTF_MFC_CLONE_SG))
mfc_source = INADDR_ANY_N;
#endif /* KERNEL_MFC_WC_G */
add_kernel_cache(mrtentry, mfc_source, inner_grp, 0);
k_chg_mfc(igmp_socket, mfc_source, inner_grp,
mrtentry->incoming, mrtentry->oifs,
mrtentry2->group->rpaddr);
return TRUE;
}
}
/* Shoudn't happen: invalid routing entry? */
/* XXX: TODO: shoudn't be inner_src=INADDR_ANY? Not in the spec. */
IF_DEBUG(DEBUG_PIM_REGISTER)
logit(LOG_DEBUG, 0, "Shoudn't happen: invalid routing entry? (%s, %s, %s, %s)",
inet_fmt(reg_dst, s1, sizeof(s1)), inet_fmt(reg_src, s2, sizeof(s2)),
inet_fmt(inner_grp, s3, sizeof(s3)), inet_fmt(inner_src, s4, sizeof(s4)));
send_pim_register_stop(reg_dst, reg_src, inner_grp, inner_src);
return TRUE;
}
int send_pim_register(char *packet)
{
struct ip *ip;
uint32_t source, group;
vifi_t vifi;
rpentry_t *rpentry;
mrtentry_t *mrtentry;
mrtentry_t *mrtentry2;
uint32_t reg_src, reg_dst;
int reg_mtu, pktlen = 0;
char *buf;
ip = (struct ip *)packet;
source = ip->ip_src.s_addr;
group = ip->ip_dst.s_addr;
if (IN_PIM_SSM_RANGE(group))
return FALSE; /* Group is in PIM-SSM range, don't send register. */
if ((vifi = find_vif_direct_local(source)) == NO_VIF)
return FALSE;
if (!(uvifs[vifi].uv_flags & VIFF_DR))
return FALSE; /* I am not the DR for that subnet */
rpentry = rp_match(group);
if (!rpentry)
return FALSE; /* No RP for this group */
if (local_address(rpentry->address) != NO_VIF) {
/* TODO: XXX: not sure it is working! */
return FALSE; /* I am the RP for this group */
}
mrtentry = find_route(source, group, MRTF_SG, CREATE);
if (!mrtentry)
return FALSE; /* Cannot create (S,G) state */
if (mrtentry->flags & MRTF_NEW) {
/* A new entry, log it */
reg_src = uvifs[vifi].uv_lcl_addr;
reg_dst = mrtentry->group->rpaddr;
logit(LOG_INFO, 0, "Send PIM REGISTER: src %s dst %s, group %s",
inet_fmt(reg_src, s1, sizeof(s1)), inet_fmt(reg_dst, s2, sizeof(s2)),
inet_fmt(group, s3, sizeof(s3)));
mrtentry->flags &= ~MRTF_NEW;
RESET_TIMER(mrtentry->rs_timer); /* Reset the Register-Suppression timer */
mrtentry2 = mrtentry->group->grp_route;
if (!mrtentry2)
mrtentry2 = mrtentry->group->active_rp_grp->rp->rpentry->mrtlink;
if (mrtentry2) {
FIRE_TIMER(mrtentry2->jp_timer); /* Timeout the Join/Prune timer */
/* TODO: explicitly call this function?
send_pim_join_prune(mrtentry2->upstream->vifi,
mrtentry2->upstream,
PIM_JOIN_PRUNE_HOLDTIME);
*/
}
}
/* Restart the (S,G) Entry-timer */
SET_TIMER(mrtentry->timer, PIM_DATA_TIMEOUT);
IF_TIMER_NOT_SET(mrtentry->rs_timer) {
/* The Register-Suppression Timer is not running.
* Encapsulate the data and send to the RP.
*/
buf = pim_send_buf + sizeof(struct ip) + sizeof(pim_header_t);
memset(buf, 0, sizeof(pim_register_t)); /* No flags set */
buf += sizeof(pim_register_t);
/* Copy the data packet at the back of the register packet */
pktlen = ntohs(ip->ip_len);
memcpy(buf, ip, pktlen);
pktlen += sizeof(pim_register_t); /* 'sizeof(struct ip) + sizeof(pim_header_t)' added by send_pim() */
reg_mtu = uvifs[vifi].uv_mtu; /* XXX: Use PMTU to RP instead! */
reg_src = uvifs[vifi].uv_lcl_addr;
reg_dst = mrtentry->group->rpaddr;
send_pim_unicast(pim_send_buf, reg_mtu, reg_src, reg_dst, PIM_REGISTER, pktlen);
return TRUE;
}
return TRUE;
}
int send_pim_null_register(mrtentry_t *mrtentry)
{
struct ip *ip;
pim_register_t *pim_register;
int reg_mtu, pktlen;
vifi_t vifi;
uint32_t reg_src, reg_dst;
/* No directly connected source; no local address */
if ((vifi = find_vif_direct_local(mrtentry->source->address))== NO_VIF)
return FALSE;
pim_register = (pim_register_t *)(pim_send_buf + sizeof(struct ip) +
sizeof(pim_header_t));
memset(pim_register, 0, sizeof(pim_register_t));
pim_register->reg_flags = htonl(pim_register->reg_flags
| PIM_REGISTER_NULL_REGISTER_BIT);
ip = (struct ip *)(pim_register + 1);
/* set src/dst in dummy hdr */
ip->ip_v = IPVERSION;
ip->ip_hl = (sizeof(struct ip) >> 2);
ip->ip_tos = 0;
ip->ip_id = 0;
ip->ip_off = 0;
ip->ip_p = IPPROTO_UDP; /* XXX: bogus */
ip->ip_len = htons(sizeof(struct ip));
ip->ip_ttl = MINTTL; /* TODO: XXX: check whether need to setup the ttl */
ip->ip_src.s_addr = mrtentry->source->address;
ip->ip_dst.s_addr = mrtentry->group->group;
ip->ip_sum = 0;