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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"
/*
* Local functions definitions.
*/
static int parse_pim_hello (char *pim_message, size_t datalen, u_int32 src, u_int16 *holdtime);
static int send_pim_register_stop (u_int32 reg_src, u_int32 reg_dst, u_int32 inner_source, u_int32 inner_grp);
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 (pim_nbr_entry_t *pim_nbr);
static void send_jp_message (pim_nbr_entry_t *pim_nbr);
static int compare_metrics (u_int32 local_preference,
u_int32 local_metric,
u_int32 local_address,
u_int32 remote_preference,
u_int32 remote_metric,
u_int32 remote_address);
build_jp_message_t *build_jp_message_pool;
int build_jp_message_pool_counter;
/************************************************************************
* PIM_HELLO
************************************************************************/
int receive_pim_hello(u_int32 src, u_int32 dst __attribute__((unused)), char *pim_message, size_t datalen)
{
vifi_t vifi;
struct uvif *v;
pim_nbr_entry_t *nbr, *prev_nbr, *new_nbr;
u_int16 holdtime = 0;
int bsr_length;
u_int8 *data_ptr __attribute__((unused));
srcentry_t *srcentry_ptr;
mrtentry_t *mrtentry_ptr;
/* Checksum */
if (inet_cksum((u_int16 *)pim_message, datalen))
return FALSE;
if ((vifi = find_vif_direct(src)) == 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_INFO, 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 */
data_ptr = (u_int8 *)(pim_message + sizeof(pim_header_t));
/* Get the Holdtime (in seconds) from the message. Return if error. */
if (parse_pim_hello(pim_message, datalen, src, &holdtime) == 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)), holdtime);
}
for (prev_nbr = (pim_nbr_entry_t *)NULL, nbr = v->uv_pim_neighbors;
nbr != (pim_nbr_entry_t *)NULL;
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 == 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;
}
SET_TIMER(nbr->timer, holdtime);
return TRUE;
}
else {
/*
* No entry for this neighbor. Exit the loop and 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`
*/
new_nbr = (pim_nbr_entry_t *)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;
SET_TIMER(new_nbr->timer, holdtime);
new_nbr->build_jp_message = (build_jp_message_t *)NULL;
new_nbr->next = nbr;
new_nbr->prev = prev_nbr;
if (prev_nbr != (pim_nbr_entry_t *)NULL)
prev_nbr->next = new_nbr;
else
v->uv_pim_neighbors = new_nbr;
if (new_nbr->next != (pim_nbr_entry_t *)NULL)
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);
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_lcl_addr, src, PIM_BOOTSTRAP, bsr_length);
/* The router with highest network address is the elected DR */
if (ntohl(v->uv_lcl_addr) < ntohl(src)) {
/* 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_ptr = srclist->next;
srcentry_ptr != (srcentry_t *)NULL;
srcentry_ptr = srcentry_ptr->next) {
/* If not directly connected source for vifi */
if ((srcentry_ptr->incoming != vifi)
|| (srcentry_ptr->upstream != (pim_nbr_entry_t *)NULL))
continue;
for (mrtentry_ptr = srcentry_ptr->mrtlink;
mrtentry_ptr != (mrtentry_t *)NULL;
mrtentry_ptr = mrtentry_ptr->srcnext) {
if (!(mrtentry_ptr->flags & MRTF_SG))
continue; /* This is not (S,G) entry */
/* Remove the register oif */
VIFM_CLR(reg_vif_num, mrtentry_ptr->joined_oifs);
change_interfaces(mrtentry_ptr,
mrtentry_ptr->incoming,
mrtentry_ptr->joined_oifs,
mrtentry_ptr->pruned_oifs,
mrtentry_ptr->leaves,
mrtentry_ptr->asserted_oifs, 0);
}
}
v->uv_flags &= ~VIFF_DR;
}
}
/*
* 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 *srcentry_ptr;
srcentry_t *srcentry_ptr_next;
mrtentry_t *mrtentry_ptr;
mrtentry_t *mrtentry_srcs;
grpentry_t *grpentry_ptr;
pim_nbr_entry_t *new_nbr __attribute__((unused));
cand_rp_t *cand_rp_ptr;
rp_grp_entry_t *rp_grp_entry_ptr;
rpentry_t *rpentry_ptr;
struct uvif *v;
v = &uvifs[nbr_delete->vifi];
/* Delete the entry from the pim_nbrs chain */
if (nbr_delete->prev != (pim_nbr_entry_t *)NULL)
nbr_delete->prev->next = nbr_delete->next;
else
v->uv_pim_neighbors = nbr_delete->next;
if (nbr_delete->next != (pim_nbr_entry_t *)NULL)
nbr_delete->next->prev = nbr_delete->prev;
return_jp_working_buff(nbr_delete);
if (v->uv_pim_neighbors == (pim_nbr_entry_t *)NULL) {
/* This was our last neighbor. */
v->uv_flags &= ~VIFF_PIM_NBR;
v->uv_flags |= (VIFF_NONBRS | VIFF_DR);
}
else {
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;
}
/* Update the source entries */
for (srcentry_ptr = srclist; srcentry_ptr != (srcentry_t *)NULL;
srcentry_ptr = srcentry_ptr_next) {
srcentry_ptr_next = srcentry_ptr->next;
if (srcentry_ptr->upstream != nbr_delete)
continue;
/* Reset the next hop (PIM) router */
if (set_incoming(srcentry_ptr, 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.
*/
delete_srcentry(srcentry_ptr);
}
else if (srcentry_ptr->upstream != (pim_nbr_entry_t *)NULL) {
/* 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.
*/
new_nbr = srcentry_ptr->upstream;
for (mrtentry_ptr = srcentry_ptr->mrtlink;
mrtentry_ptr != (mrtentry_t *)NULL;
mrtentry_ptr = mrtentry_ptr->srcnext) {
if (!(mrtentry_ptr->flags & MRTF_RP)) {
mrtentry_ptr->upstream = srcentry_ptr->upstream;
mrtentry_ptr->metric = srcentry_ptr->metric;
mrtentry_ptr->preference = srcentry_ptr->preference;
change_interfaces(mrtentry_ptr, srcentry_ptr->incoming,
mrtentry_ptr->joined_oifs,
mrtentry_ptr->pruned_oifs,
mrtentry_ptr->leaves,
mrtentry_ptr->asserted_oifs, 0);
}
}
}
}
/* Update the RP entries */
for (cand_rp_ptr = cand_rp_list; cand_rp_ptr != (cand_rp_t *)NULL;
cand_rp_ptr = cand_rp_ptr->next) {
if (cand_rp_ptr->rpentry->upstream != nbr_delete)
continue;
rpentry_ptr = cand_rp_ptr->rpentry;
/* Reset the RP entry iif */
/* TODO: check if error setting the iif! */
if (local_address(rpentry_ptr->address) == NO_VIF)
set_incoming(rpentry_ptr, PIM_IIF_RP);
else {
rpentry_ptr->incoming = reg_vif_num;
rpentry_ptr->upstream = (pim_nbr_entry_t *)NULL;
}
mrtentry_ptr = rpentry_ptr->mrtlink;
if (mrtentry_ptr != (mrtentry_t *)NULL) {
mrtentry_ptr->upstream = rpentry_ptr->upstream;
mrtentry_ptr->metric = rpentry_ptr->metric;
mrtentry_ptr->preference = rpentry_ptr->preference;
change_interfaces(mrtentry_ptr,
rpentry_ptr->incoming,
mrtentry_ptr->joined_oifs,
mrtentry_ptr->pruned_oifs,
mrtentry_ptr->leaves,
mrtentry_ptr->asserted_oifs, 0);
}
/* Update the group entries for this RP */
for (rp_grp_entry_ptr = cand_rp_ptr->rp_grp_next;
rp_grp_entry_ptr != (rp_grp_entry_t *)NULL;
rp_grp_entry_ptr = rp_grp_entry_ptr->rp_grp_next) {
for (grpentry_ptr = rp_grp_entry_ptr->grplink;
grpentry_ptr != (grpentry_t *)NULL;
grpentry_ptr = grpentry_ptr->rpnext) {
mrtentry_ptr = grpentry_ptr->grp_route;
if (mrtentry_ptr != (mrtentry_t *)NULL) {
mrtentry_ptr->upstream = rpentry_ptr->upstream;
mrtentry_ptr->metric = rpentry_ptr->metric;
mrtentry_ptr->preference = rpentry_ptr->preference;
change_interfaces(mrtentry_ptr,
rpentry_ptr->incoming,
mrtentry_ptr->joined_oifs,
mrtentry_ptr->pruned_oifs,
mrtentry_ptr->leaves,
mrtentry_ptr->asserted_oifs, 0);
}
/* Update only the (S,G)RPbit entries for this group */
for (mrtentry_srcs = grpentry_ptr->mrtlink;
mrtentry_srcs != (mrtentry_t *)NULL;
mrtentry_srcs = mrtentry_srcs->grpnext) {
if (mrtentry_srcs->flags & MRTF_RP) {
mrtentry_ptr->upstream = rpentry_ptr->upstream;
mrtentry_ptr->metric = rpentry_ptr->metric;
mrtentry_ptr->preference = rpentry_ptr->preference;
change_interfaces(mrtentry_srcs,
rpentry_ptr->incoming,
mrtentry_srcs->joined_oifs,
mrtentry_srcs->pruned_oifs,
mrtentry_srcs->leaves,
mrtentry_srcs->asserted_oifs, 0);
}
}
}
}
}
free((char *)nbr_delete);
}
/* TODO: simplify it! */
static int parse_pim_hello(char *pim_message, size_t datalen, u_int32 src, u_int16 *holdtime)
{
u_int8 *pim_hello_message;
u_int8 *data_ptr;
u_int16 option_type;
u_int16 option_length;
int holdtime_received_ok = FALSE;
int option_total_length;
pim_hello_message = (u_int8 *)(pim_message + sizeof(pim_header_t));
datalen -= sizeof(pim_header_t);
for ( ; datalen >= sizeof(pim_hello_t); ) {
/* Ignore any data if shorter than (pim_hello header) */
data_ptr = pim_hello_message;
GET_HOSTSHORT(option_type, data_ptr);
GET_HOSTSHORT(option_length, data_ptr);
if (option_type == PIM_MESSAGE_HELLO_HOLDTIME) {
if (PIM_MESSAGE_HELLO_HOLDTIME_LENGTH != option_length) {
IF_DEBUG(DEBUG_PIM_HELLO) {
logit(LOG_DEBUG, 0, "PIM HELLO Holdtime from %s: invalid OptionLength = %u",
inet_fmt(src, s1, sizeof(s1)), option_length);
}
return FALSE;
}
GET_HOSTSHORT(*holdtime, data_ptr);
holdtime_received_ok = TRUE;
} else {
/* Ignore any unknown options */
}
/* Move to the next option */
/* XXX: TODO: If we are padding to the end of the 32 bit boundary,
* use the first method to move to the next option, otherwise
* simply (sizeof(pim_hello_t) + option_length).
*/
#ifdef BOUNDARY_32_BIT
option_total_length = (sizeof(pim_hello_t) + (option_length & ~0x3) +
((option_length & 0x3) ? 4 : 0));
#else
option_total_length = (sizeof(pim_hello_t) + option_length);
#endif /* BOUNDARY_32_BIT */
datalen -= option_total_length;
pim_hello_message += option_total_length;
}
return holdtime_received_ok;
}
int send_pim_hello(struct uvif *v, u_int16 holdtime)
{
char *buf;
u_int8 *data_ptr;
int datalen;
buf = pim_send_buf + sizeof(struct ip) + sizeof(pim_header_t);
data_ptr = (u_int8 *)buf;
PUT_HOSTSHORT(PIM_MESSAGE_HELLO_HOLDTIME, data_ptr);
PUT_HOSTSHORT(PIM_MESSAGE_HELLO_HOLDTIME_LENGTH, data_ptr);
PUT_HOSTSHORT(holdtime, data_ptr);
datalen = data_ptr - (u_int8 *)buf;
send_pim(pim_send_buf, v->uv_lcl_addr, allpimrouters_group, PIM_HELLO, datalen);
SET_TIMER(v->uv_pim_hello_timer, PIM_TIMER_HELLO_PERIOD);
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(u_int32 reg_src, u_int32 reg_dst, char *pim_message, size_t datalen)
{
u_int32 inner_src, inner_grp;
pim_register_t *register_p;
struct ip *ip;
u_int32 borderBit, nullRegisterBit;
mrtentry_t *mrtentry_ptr;
mrtentry_t *mrtentry_ptr2;
vifbitmap_t oifs;
/*
* 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 (datalen < 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",
datalen, 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((u_int16 *)pim_message, sizeof(pim_header_t) + sizeof(pim_register_t)))
&& (inet_cksum((u_int16 *)pim_message, datalen))) {
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;
}
register_p = (pim_register_t *)(pim_message + sizeof(pim_header_t));
borderBit = ntohl(register_p->reg_flags) & PIM_MESSAGE_REGISTER_BORDER_BIT;
nullRegisterBit = ntohl(register_p->reg_flags) & PIM_MESSAGE_REGISTER_NULL_REGISTER_BIT;
/* initialize the pointer to the encapsulated packet */
ip = (struct ip *)(register_p + 1);
/* check the IP version (especially for the NULL register...see above) */
if (ip->ip_v != IPVERSION && (! nullRegisterBit)) {
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.
*/
if ((!inet_valid_host(inner_src)) || (!IN_MULTICAST(ntohl(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_ptr = find_route(inner_src, inner_grp, MRTF_SG | MRTF_WC | MRTF_PMBR, DONT_CREATE);
if (!mrtentry_ptr) {
/* 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: shoudn't be inner_src=INADDR_ANY? Not in the spec. */
send_pim_register_stop(reg_dst, reg_src, inner_grp, inner_src);
return TRUE;
}
/* XXX: not in the spec: check if I am the RP for that group */
if ((local_address(reg_dst) == NO_VIF) ||
(check_mrtentry_rp(mrtentry_ptr, reg_dst) == FALSE)) {
send_pim_register_stop(reg_dst, reg_src, inner_grp, inner_src);
return TRUE;
}
if (mrtentry_ptr->flags & MRTF_SG) {
/* (S,G) found */
/* TODO: check the timer again */
SET_TIMER(mrtentry_ptr->timer, PIM_DATA_TIMEOUT); /* restart timer */
if (!(mrtentry_ptr->flags & MRTF_SPT)) { /* The SPT bit is not set */
if (!nullRegisterBit) {
calc_oifs(mrtentry_ptr, &oifs);
if (VIFM_ISEMPTY(oifs) && (mrtentry_ptr->incoming == reg_vif_num)) {
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 (borderBit) {
if (mrtentry_ptr->pmbr_addr != reg_src) {
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 */
send_pim_register_stop(reg_dst, reg_src, inner_grp, inner_src);
return TRUE;
}
}
if (mrtentry_ptr->flags & (MRTF_WC | MRTF_PMBR)) {
if (borderBit) {
/* Create (S,G) state. The oifs will be the copied from the
* existing (*,G) or (*,*,RP) entry. */
mrtentry_ptr2 = find_route(inner_src, inner_grp, MRTF_SG, CREATE);
if (mrtentry_ptr2) {
mrtentry_ptr2->pmbr_addr = reg_src;
/* Clear the SPT flag */
mrtentry_ptr2->flags &= ~(MRTF_SPT | MRTF_NEW);
SET_TIMER(mrtentry_ptr2->timer, PIM_DATA_TIMEOUT);
/* TODO: explicitly call the Join/Prune send function? */
FIRE_TIMER(mrtentry_ptr2->jp_timer); /* Send the Join immediately */
/* TODO: explicitly call this function?
send_pim_join_prune(mrtentry_ptr2->upstream->vifi,
mrtentry_ptr2->upstream,
PIM_JOIN_PRUNE_HOLDTIME);
*/
}
}
}
if (mrtentry_ptr->flags & MRTF_WC) {
/* (*,G) entry */
calc_oifs(mrtentry_ptr, &oifs);
if (VIFM_ISEMPTY(oifs)) {
send_pim_register_stop(reg_dst, reg_src, inner_grp, INADDR_ANY_N);
return FALSE;
}
/* XXX: TODO: check with the spec again */
else {
if (!nullRegisterBit) {
/* Install cache entry in the kernel */
/* TODO: XXX: probably redundant here, because the
* decapsulated mcast packet in the kernel will
* result in CACHE_MISS
*/
u_int32 mfc_source = inner_src;
#ifdef KERNEL_MFC_WC_G
if (!(mrtentry_ptr->flags & MRTF_MFC_CLONE_SG))
mfc_source = INADDR_ANY_N;
#endif /* KERNEL_MFC_WC_G */
add_kernel_cache(mrtentry_ptr, mfc_source, inner_grp, 0);
k_chg_mfc(igmp_socket, mfc_source, inner_grp,
mrtentry_ptr->incoming, mrtentry_ptr->oifs,
mrtentry_ptr->group->rpaddr);
return TRUE;
}
}
return TRUE;
}
if (mrtentry_ptr->flags & MRTF_PMBR) {
/* (*,*,RP) entry */
if (!nullRegisterBit) {
u_int32 mfc_source = inner_src;
/* XXX: have to create either (S,G) or (*,G).
* The choice below is (*,G)
*/
mrtentry_ptr2 = find_route(INADDR_ANY_N, inner_grp, MRTF_WC, CREATE);
if (!mrtentry_ptr2)
return FALSE;
if (mrtentry_ptr2->flags & MRTF_NEW) {
/* TODO: something else? Have the feeling sth is missing */
mrtentry_ptr2->flags &= ~MRTF_NEW;
/* TODO: XXX: copy the timer from the (*,*,RP) entry? */
COPY_TIMER(mrtentry_ptr->timer, mrtentry_ptr2->timer);
}
/* Install cache entry in the kernel */
#ifdef KERNEL_MFC_WC_G
if (!(mrtentry_ptr->flags & MRTF_MFC_CLONE_SG))
mfc_source = INADDR_ANY_N;
#endif /* KERNEL_MFC_WC_G */
add_kernel_cache(mrtentry_ptr, mfc_source, inner_grp, 0);
k_chg_mfc(igmp_socket, mfc_source, inner_grp,
mrtentry_ptr->incoming, mrtentry_ptr->oifs,
mrtentry_ptr2->group->rpaddr);
return TRUE;
}
}
/* Shoudn't happen: invalid routing entry? */
/* XXX: TODO: shoudn't be inner_src=INADDR_ANY? Not in the spec. */
send_pim_register_stop(reg_dst, reg_src, inner_grp, inner_src);
return TRUE;
}
int send_pim_register(char *packet)
{
struct ip *ip;
u_int32 source, group;
vifi_t vifi;
rpentry_t *rpentry_ptr;
mrtentry_t *mrtentry_ptr;
mrtentry_t *mrtentry_ptr2;
u_int32 reg_src, reg_dst;
int pktlen = 0;
char *buf;
ip = (struct ip *)packet;
source = ip->ip_src.s_addr;
group = ip->ip_dst.s_addr;
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_ptr = rp_match(group);
if (!rpentry_ptr)
return FALSE; /* No RP for this group */
if (local_address(rpentry_ptr->address) != NO_VIF) {
/* TODO: XXX: not sure it is working! */
return FALSE; /* I am the RP for this group */
}
mrtentry_ptr = find_route(source, group, MRTF_SG, CREATE);
if (!mrtentry_ptr)
return FALSE; /* Cannot create (S,G) state */
if (mrtentry_ptr->flags & MRTF_NEW) {
/* A new entry */
mrtentry_ptr->flags &= ~MRTF_NEW;
RESET_TIMER(mrtentry_ptr->rs_timer); /* Reset the Register-Suppression timer */
mrtentry_ptr2 = mrtentry_ptr->group->grp_route;
if (!mrtentry_ptr2)
mrtentry_ptr2 = mrtentry_ptr->group->active_rp_grp->rp->rpentry->mrtlink;
if (mrtentry_ptr2) {
FIRE_TIMER(mrtentry_ptr2->jp_timer); /* Timeout the Join/Prune timer */
/* TODO: explicitly call this function?
send_pim_join_prune(mrtentry_ptr2->upstream->vifi,
mrtentry_ptr2->upstream,
PIM_JOIN_PRUNE_HOLDTIME);
*/
}
}
/* Restart the (S,G) Entry-timer */
SET_TIMER(mrtentry_ptr->timer, PIM_DATA_TIMEOUT);
IF_TIMER_NOT_SET(mrtentry_ptr->rs_timer) {
/* The Register-Suppression Timer is not running.
* Encapsulate the data and send to the RP.
*/
#ifdef PIM_OLD_KERNEL
/* TODO: verify again! */
/* recompute the checksum; as checksum may fail when decapsulating
* at the RP if we don't do this.
*/
#ifdef old_Linux
ip->ip_csum = 0;
#else
ip->ip_sum = 0;
#endif /* old_Linux */
#ifndef RAW_INPUT_IS_RAW
/* TODO: htons??? */
ip->ip_len = htons(ip->ip_len);
ip->ip_off = htons(ip->ip_off);
#endif /* !RAW_INPUT_IS_RAW */
#ifdef old_Linux
ip->ip_csum = inet_cksum((u_int16 *)ip, ip->ip_hl << 2);
#else
ip->ip_sum = inet_cksum((u_int16 *)ip, ip->ip_hl << 2);
#endif /* old_Linux */
#endif /* PIM_OLD_KERNEL */
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 */
/* TODO: check pktlen. ntohs? */
pktlen = ntohs(ip->ip_len);
memcpy(buf, ip, pktlen);
pktlen += sizeof(pim_register_t);
reg_src = uvifs[vifi].uv_lcl_addr;
reg_dst = mrtentry_ptr->group->rpaddr;
send_pim_unicast(pim_send_buf, reg_src, reg_dst,
PIM_REGISTER, pktlen);
return TRUE;
}
return TRUE;
}
int send_pim_null_register(mrtentry_t *mrtentry_ptr)
{
struct ip *ip;
pim_register_t *pim_register;
int pktlen =0;
vifi_t vifi;
u_int32 reg_source, dest;
/* No directly connected source; no local address */
if ((vifi = find_vif_direct_local(mrtentry_ptr->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_MESSAGE_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_ptr->source->address;
ip->ip_dst.s_addr = mrtentry_ptr->group->group;
#ifdef old_Linux
ip->ip_csum = 0;
ip->ip_csum = inet_cksum((u_int16 *)ip, sizeof(struct ip));
#else
ip->ip_sum = 0;
ip->ip_sum = inet_cksum((u_int16 *)ip, sizeof(struct ip));
#endif /* old_Linux */
/* include the dummy ip header */
pktlen = sizeof(pim_register_t) + sizeof(struct ip);
dest = mrtentry_ptr->group->rpaddr;
reg_source = uvifs[vifi].uv_lcl_addr;
send_pim_unicast(pim_send_buf, reg_source, dest, PIM_REGISTER, pktlen);
return TRUE;
}
/************************************************************************
* PIM_REGISTER_STOP
************************************************************************/
int receive_pim_register_stop(u_int32 reg_src, u_int32 reg_dst, char *pim_message, size_t datalen)
{
pim_register_stop_t *pim_regstop_p;
pim_encod_grp_addr_t encod_grp;
pim_encod_uni_addr_t encod_unisrc;
u_int8 *data_ptr;
mrtentry_t *mrtentry_ptr;
vifbitmap_t pruned_oifs;
/* Checksum */
if (inet_cksum((u_int16 *)pim_message, datalen))
return FALSE;
pim_regstop_p = (pim_register_stop_t *)(pim_message +
sizeof(pim_header_t));
data_ptr = (u_int8 *)&pim_regstop_p->encod_grp;
GET_EGADDR(&encod_grp, data_ptr);
GET_EUADDR(&encod_unisrc, data_ptr);
IF_DEBUG(DEBUG_PIM_REGISTER) {
logit(LOG_DEBUG, 0, "Received PIM_REGISTER_STOP from RP %s to %s for src = %s and group = %s", inet_fmt(reg_src, s1, sizeof(s1)), inet_fmt(reg_dst, s2, sizeof(s2)),
inet_fmt(encod_unisrc.unicast_addr, s3, sizeof(s3)),
inet_fmt(encod_grp.mcast_addr, s4, sizeof(s4)));
}
/* TODO: apply the group mask and do register_stop for all grp addresses */
/* TODO: check for SourceAddress == 0 */
mrtentry_ptr = find_route(encod_unisrc.unicast_addr, encod_grp.mcast_addr, MRTF_SG, DONT_CREATE);
if (!mrtentry_ptr)
return FALSE;
/* XXX: not in the spec: check if the PIM_REGISTER_STOP originator is
* really the RP
*/
if (check_mrtentry_rp(mrtentry_ptr, reg_src) == FALSE)
return FALSE;
/* restart the Register-Suppression timer */
SET_TIMER(mrtentry_ptr->rs_timer, (0.5 * PIM_REGISTER_SUPPRESSION_TIMEOUT)
+ (RANDOM() % (PIM_REGISTER_SUPPRESSION_TIMEOUT + 1)));
/* Prune the register_vif from the outgoing list */
VIFM_COPY(mrtentry_ptr->pruned_oifs, pruned_oifs);
VIFM_SET(reg_vif_num, pruned_oifs);
change_interfaces(mrtentry_ptr, mrtentry_ptr->incoming,
mrtentry_ptr->joined_oifs, pruned_oifs,
mrtentry_ptr->leaves,
mrtentry_ptr->asserted_oifs, 0);
return TRUE;
}
/* TODO: optional rate limiting is not implemented yet */
/* Unicasts a REGISTER_STOP message to the DR */
static int
send_pim_register_stop(u_int32 reg_src, u_int32 reg_dst, u_int32 inner_grp, u_int32 inner_src)
{
char *buf;
u_int8 *data_ptr;
buf = pim_send_buf + sizeof(struct ip) + sizeof(pim_header_t);
data_ptr = (u_int8 *)buf;
PUT_EGADDR(inner_grp, SINGLE_GRP_MSKLEN, 0, data_ptr);
PUT_EUADDR(inner_src, data_ptr);
send_pim_unicast(pim_send_buf, reg_src, reg_dst, PIM_REGISTER_STOP, data_ptr - (u_int8 *)buf);
return TRUE;
}
/************************************************************************
* PIM_JOIN_PRUNE
************************************************************************/
int join_or_prune(mrtentry_t *mrtentry_ptr, pim_nbr_entry_t *upstream_router)
{
vifbitmap_t entry_oifs;
mrtentry_t *mrtentry_grp;
if (!mrtentry_ptr || !upstream_router)
return PIM_ACTION_NOTHING;
calc_oifs(mrtentry_ptr, &entry_oifs);
if (mrtentry_ptr->flags & (MRTF_PMBR | MRTF_WC)) {
/* (*,*,RP) or (*,G) entry */
/* The (*,*,RP) or (*,G) J/P messages are sent only toward the RP */
if (upstream_router != mrtentry_ptr->upstream)
return PIM_ACTION_NOTHING;
/* TODO: XXX: Can we have (*,*,RP) prune? */
if (VIFM_ISEMPTY(entry_oifs)) {
/* NULL oifs */
if (!(uvifs[mrtentry_ptr->incoming].uv_flags & VIFF_DR))
/* I am not the DR for that subnet. */
return PIM_ACTION_PRUNE;
if (VIFM_ISSET(mrtentry_ptr->incoming, mrtentry_ptr->leaves))
/* I am the DR and have local leaves */
return PIM_ACTION_JOIN;
/* Probably the last local member hast timeout */
return PIM_ACTION_PRUNE;
}
return PIM_ACTION_JOIN;
}
if (mrtentry_ptr->flags & MRTF_SG) {
/* (S,G) entry */
/* TODO: check again */
if (mrtentry_ptr->upstream == upstream_router) {
if (!(mrtentry_ptr->flags & MRTF_RP)) {
/* Upstream router toward S */
if (VIFM_ISEMPTY(entry_oifs)) {
if (mrtentry_ptr->group->active_rp_grp &&
mrtentry_ptr->group->rpaddr == my_cand_rp_address) {
/* (S,G) at the RP. Don't send Join/Prune
* (see the end of Section 3.3.2)
*/
return PIM_ACTION_NOTHING;
}
return PIM_ACTION_PRUNE;
}
else {
return PIM_ACTION_JOIN;
}
}
else {
/* Upstream router toward RP */
if (VIFM_ISEMPTY(entry_oifs))
return PIM_ACTION_PRUNE;
}
}
/* Looks like the case when the upstream router toward S is
* different from the upstream router toward RP
*/
if (!mrtentry_ptr->group->active_rp_grp)
return PIM_ACTION_NOTHING;
mrtentry_grp = mrtentry_ptr->group->grp_route;
if (!mrtentry_grp) {
mrtentry_grp = mrtentry_ptr->group->active_rp_grp->rp->rpentry->mrtlink;
if (!mrtentry_grp)
return PIM_ACTION_NOTHING;
}
if (mrtentry_grp->upstream != upstream_router)
return PIM_ACTION_NOTHING; /* XXX: shoudn't happen */
if (!(mrtentry_ptr->flags & MRTF_RP) && (mrtentry_ptr->flags & MRTF_SPT))
return PIM_ACTION_PRUNE;
}
return PIM_ACTION_NOTHING;
}