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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.c,v 1.24 2002/09/26 00:59:30 pavlin Exp $
*/
#include "defs.h"
#define SEND_DEBUG_NUMBER 50 /* For throttling log messages */
/*
* Exported variables.
*/
char *pim_recv_buf; /* input packet buffer */
char *pim_send_buf; /* output packet buffer */
uint32_t allpimrouters_group; /* ALL_PIM_ROUTERS address in net order */
int pim_socket; /* socket for PIM control msgs */
#ifdef RAW_OUTPUT_IS_RAW
extern int curttl;
#endif /* RAW_OUTPUT_IS_RAW */
/*
* Local variables.
*/
static uint16_t ip_id = 0;
//static u_int pim_send_cnt = 0;
/*
* Local function definitions.
*/
static void pim_read (int f, fd_set *rfd);
static void accept_pim (ssize_t recvlen);
static int send_frame (char *buf, size_t len, size_t frag, size_t mtu, struct sockaddr *dst, size_t salen);
/*
* Setup raw kernel socket for PIM protocol and send/receive buffers.
*/
void init_pim(void)
{
struct ip *ip;
/* Setup the PIM raw socket */
if ((pim_socket = socket(AF_INET, SOCK_RAW, IPPROTO_PIM)) < 0)
logit(LOG_ERR, errno, "Failed creating PIM socket");
k_hdr_include(pim_socket, TRUE); /* include IP header when sending */
k_set_sndbuf(pim_socket, SO_SEND_BUF_SIZE_MAX,
SO_SEND_BUF_SIZE_MIN); /* lots of output buffering */
k_set_rcvbuf(pim_socket, SO_RECV_BUF_SIZE_MAX,
SO_RECV_BUF_SIZE_MIN); /* lots of input buffering */
k_set_ttl(pim_socket, MINTTL); /* restrict multicasts to one hop */
k_set_loop(pim_socket, FALSE); /* disable multicast loopback */
allpimrouters_group = htonl(INADDR_ALL_PIM_ROUTERS);
pim_recv_buf = calloc(1, RECV_BUF_SIZE);
pim_send_buf = calloc(1, SEND_BUF_SIZE);
if (!pim_recv_buf || !pim_send_buf)
logit(LOG_ERR, 0, "Ran out of memory in init_pim()");
/* One time setup in the buffers */
ip = (struct ip *)pim_send_buf;
memset(ip, 0, sizeof(*ip));
ip->ip_v = IPVERSION;
ip->ip_hl = (sizeof(struct ip) >> 2);
ip->ip_tos = 0; /* TODO: setup?? */
ip->ip_id = 0; /* Make sure to update ID field, maybe fragmenting below */
ip->ip_off = 0;
ip->ip_p = IPPROTO_PIM;
ip->ip_sum = 0; /* let kernel fill in */
if (register_input_handler(pim_socket, pim_read) < 0)
logit(LOG_ERR, 0, "Failed registering pim_read() as an input handler");
/* Initialize the building Join/Prune messages working area */
build_jp_message_pool = (build_jp_message_t *)NULL;
build_jp_message_pool_counter = 0;
}
/* Read a PIM message */
static void pim_read(int f __attribute__((unused)), fd_set *rfd __attribute__((unused)))
{
ssize_t len;
socklen_t dummy = 0;
sigset_t block, oblock;
while ((len = recvfrom(pim_socket, pim_recv_buf, RECV_BUF_SIZE, 0, NULL, &dummy)) < 0) {
if (errno == EINTR)
continue; /* Received signal, retry syscall. */
logit(LOG_ERR, errno, "Failed recvfrom() in pim_read()");
return;
}
sigemptyset(&block);
sigaddset(&block, SIGALRM);
if (sigprocmask(SIG_BLOCK, &block, &oblock) < 0)
logit(LOG_ERR, errno, "sigprocmask");
accept_pim(len);
sigprocmask(SIG_SETMASK, &oblock, (sigset_t *)NULL);
}
static void accept_pim(ssize_t recvlen)
{
uint32_t src, dst;
struct ip *ip;
pim_header_t *pim;
int iphdrlen, pimlen;
char source[20], dest[20];
if (recvlen < (ssize_t)sizeof(struct ip)) {
logit(LOG_WARNING, 0, "Received PIM packet too short (%u bytes) for IP header", recvlen);
return;
}
ip = (struct ip *)pim_recv_buf;
src = ip->ip_src.s_addr;
dst = ip->ip_dst.s_addr;
iphdrlen = ip->ip_hl << 2;
pim = (pim_header_t *)(pim_recv_buf + iphdrlen);
pimlen = recvlen - iphdrlen;
/* Sanity check packet length */
if (pimlen < (ssize_t)sizeof(*pim)) {
logit(LOG_WARNING, 0, "IP data field too short (%d bytes) for PIM header, from %s to %s",
pimlen, inet_fmt(src, source, sizeof(source)), inet_fmt(dst, dest, sizeof(dest)));
return;
}
IF_DEBUG(DEBUG_PIM_DETAIL) {
IF_DEBUG(DEBUG_PIM) {
logit(LOG_DEBUG, 0, "RECV %5d bytes %s from %-15s to %s ", recvlen,
packet_kind(IPPROTO_PIM, pim->pim_type, 0),
inet_fmt(src, source, sizeof(source)), inet_fmt(dst, dest, sizeof(dest)));
}
}
/* TODO: Check PIM version */
/* TODO: check the dest. is ALL_PIM_ROUTERS (if multicast address) */
/* TODO: Checksum verification is done in each of the processing functions.
* No need for checksum, if already done in the kernel?
*/
switch (pim->pim_type) {
case PIM_HELLO:
receive_pim_hello(src, dst, (char *)(pim), pimlen);
break;
case PIM_REGISTER:
receive_pim_register(src, dst, (char *)(pim), pimlen);
break;
case PIM_REGISTER_STOP:
receive_pim_register_stop(src, dst, (char *)(pim), pimlen);
break;
case PIM_JOIN_PRUNE:
receive_pim_join_prune(src, dst, (char *)(pim), pimlen);
break;
case PIM_BOOTSTRAP:
receive_pim_bootstrap(src, dst, (char *)(pim), pimlen);
break;
case PIM_ASSERT:
receive_pim_assert(src, dst, (char *)(pim), pimlen);
break;
case PIM_GRAFT:
case PIM_GRAFT_ACK:
logit(LOG_INFO, 0, "ignore %s from %s to %s", packet_kind(IPPROTO_PIM, pim->pim_type, 0),
inet_fmt(src, source, sizeof(source)), inet_fmt(dst, dest, sizeof(dest)));
break;
case PIM_CAND_RP_ADV:
receive_pim_cand_rp_adv(src, dst, (char *)(pim), pimlen);
break;
default:
logit(LOG_INFO, 0, "ignore unknown PIM message code %u from %s to %s", pim->pim_type,
inet_fmt(src, source, sizeof(source)), inet_fmt(dst, dest, sizeof(dest)));
break;
}
}
/*
* Send a multicast PIM packet from src to dst, PIM message type = "type"
* and data length (after the PIM header) = "len"
*/
void send_pim(char *buf, uint32_t src, uint32_t dst, int type, size_t len)
{
struct sockaddr_in sin;
struct ip *ip;
pim_header_t *pim;
int sendlen = sizeof(struct ip) + sizeof(pim_header_t) + len;
int setloop = 0;
char source[20], dest[20];
/* Prepare the IP header */
ip = (struct ip *)buf;
ip->ip_id = htons(++ip_id);
ip->ip_off = 0;
ip->ip_src.s_addr = src;
ip->ip_dst.s_addr = dst;
ip->ip_ttl = MAXTTL; /* applies to unicast only */
#ifdef HAVE_IP_HDRINCL_BSD_ORDER
ip->ip_len = sendlen;
#else
ip->ip_len = htons(sendlen);
#endif
/* Prepare the PIM packet */
pim = (pim_header_t *)(buf + sizeof(struct ip));
pim->pim_type = type;
pim->pim_vers = PIM_PROTOCOL_VERSION;
pim->pim_reserved = 0;
pim->pim_cksum = 0;
/* TODO: XXX: if start using this code for PIM_REGISTERS, exclude the
* encapsulated packet from the checsum. */
pim->pim_cksum = inet_cksum((uint16_t *)pim, sizeof(pim_header_t) + len);
if (IN_MULTICAST(ntohl(dst))) {
k_set_if(pim_socket, src);
if ((dst == allhosts_group) ||
(dst == allrouters_group) ||
(dst == allpimrouters_group) ||
(dst == allreports_group)) {
setloop = 1;
k_set_loop(pim_socket, TRUE);
}
#ifdef RAW_OUTPUT_IS_RAW
ip->ip_ttl = curttl;
} else {
ip->ip_ttl = MAXTTL;
#endif /* RAW_OUTPUT_IS_RAW */
}
memset(&sin, 0, sizeof(sin));
sin.sin_family = AF_INET;
sin.sin_addr.s_addr = dst;
#ifdef HAVE_SA_LEN
sin.sin_len = sizeof(sin);
#endif
while (sendto(pim_socket, buf, sendlen, 0, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
if (errno == EINTR)
continue; /* Received signal, retry syscall. */
if (errno == ENETDOWN || errno == ENODEV)
check_vif_state();
else if (errno == EPERM || errno == EHOSTUNREACH)
logit(LOG_WARNING, 0, "Not allowed to send PIM message from %s to %s, possibly firewall"
#ifdef __linux__
", or SELinux policy violation,"
#endif
" related problem."
,
inet_fmt(src, source, sizeof(source)), inet_fmt(dst, dest, sizeof(dest)));
else
logit(LOG_WARNING, errno, "sendto from %s to %s",
inet_fmt(src, source, sizeof(source)), inet_fmt(dst, dest, sizeof(dest)));
if (setloop)
k_set_loop(pim_socket, FALSE);
return;
}
if (setloop)
k_set_loop(pim_socket, FALSE);
IF_DEBUG(DEBUG_PIM_DETAIL) {
IF_DEBUG(DEBUG_PIM) {
logit(LOG_DEBUG, 0, "SENT %5d bytes %s from %-15s to %s",
sendlen, packet_kind(IPPROTO_PIM, type, 0),
src == INADDR_ANY_N ? "INADDR_ANY" :
inet_fmt(src, source, sizeof(source)), inet_fmt(dst, dest, sizeof(dest)));
}
}
}
/* TODO: This can be merged with the above procedure */
/*
* Send an unicast PIM packet from src to dst, PIM message type = "type"
* and data length (after the PIM common header) = "len"
*/
void send_pim_unicast(char *buf, int mtu, uint32_t src, uint32_t dst, int type, size_t len)
{
struct sockaddr_in sin;
struct ip *ip;
pim_header_t *pim;
int result, sendlen = sizeof(struct ip) + sizeof(pim_header_t) + len;
char source[20], dest[20];
/* Prepare the IP header */
ip = (struct ip *)buf;
ip->ip_id = htons(++ip_id);
ip->ip_src.s_addr = src;
ip->ip_dst.s_addr = dst;
ip->ip_ttl = MAXTTL; /* TODO: XXX: setup TTL from the inner mcast packet? */
#ifdef HAVE_IP_HDRINCL_BSD_ORDER
ip->ip_len = sendlen;
#else
ip->ip_len = htons(sendlen);
#endif
/* Prepare the PIM packet */
pim = (pim_header_t *)(buf + sizeof(struct ip));
pim->pim_type = type;
pim->pim_vers = PIM_PROTOCOL_VERSION;
pim->pim_reserved = 0;
pim->pim_cksum = 0;
/* XXX: The PIM_REGISTERs don't include the encapsulated
* inner packet in the checksum.
* Well, try to explain this to cisco...
* If your RP is cisco and if it shows many PIM_REGISTER checksum
* errors from this router, then #define BROKEN_CISCO_CHECKSUM here
* or in your Makefile.
* Note that such checksum is not in the spec, and such PIM_REGISTERS
* may be dropped by some implementations (pimd should be OK).
*/
#ifdef BROKEN_CISCO_CHECKSUM
pim->pim_cksum = inet_cksum((uint16_t *)pim, sizeof(pim_header_t) + len);
#else
if (PIM_REGISTER == type) {
pim->pim_cksum = inet_cksum((uint16_t *)pim, sizeof(pim_header_t) + sizeof(pim_register_t));
} else {
pim->pim_cksum = inet_cksum((uint16_t *)pim, sizeof(pim_header_t) + len);
}
#endif /* BROKEN_CISCO_CHECKSUM */
memset(&sin, 0, sizeof(sin));
sin.sin_family = AF_INET;
sin.sin_addr.s_addr = dst;
#ifdef HAVE_SA_LEN
sin.sin_len = sizeof(sin);
#endif
IF_DEBUG(DEBUG_PIM_DETAIL) {
IF_DEBUG(DEBUG_PIM) {
logit(LOG_DEBUG, 0, "SEND %5d bytes %s from %-15s to %s ...",
sendlen, packet_kind(IPPROTO_PIM, type, 0),
inet_fmt(src, source, sizeof(source)), inet_fmt(dst, dest, sizeof(dest)));
}
}
result = send_frame(buf, sendlen, 0, mtu, (struct sockaddr *)&sin, sizeof(sin));
if (result) {
logit(LOG_WARNING, errno, "sendto from %s to %s",
inet_fmt(ip->ip_src.s_addr, source, sizeof(source)),
inet_fmt(ip->ip_dst.s_addr, dest, sizeof(dest)));
return;
}
IF_DEBUG(DEBUG_PIM_DETAIL) {
IF_DEBUG(DEBUG_PIM) {
#if 0 /* TODO: use pim_send_cnt? */
if (++pim_send_cnt > SEND_DEBUG_NUMBER) {
pim_send_cnt = 0;
logit(LOG_DEBUG, 0, "SENT %5d bytes %s from %-15s to %s",
sendlen, packet_kind(IPPROTO_PIM, type, 0),
inet_fmt(src, source, sizeof(source)), inet_fmt(dst, dest, sizeof(dest)));
}
#endif
logit(LOG_DEBUG, 0, "SENT %5d bytes %s from %-15s to %s",
sendlen, packet_kind(IPPROTO_PIM, type, 0),
inet_fmt(src, source, sizeof(source)), inet_fmt(dst, dest, sizeof(dest)));
}
}
}
#if 1
/*
* send unicast register frames
* Version: Michael Fine
* Staus: Works, albeit non-optimal
* Design: Only fragments if sendto() fails with EMSGSIZE
* It then tries to re-send by splitting the frame in two equal halves,
* calling send_frame() recursively until the frame has been sent.
*/
static int send_frame(char *buf, size_t len, size_t frag, size_t mtu, struct sockaddr *dst, size_t salen)
{
struct ip *ip = (struct ip *)buf;
char source[20], dest[20];
IF_DEBUG(DEBUG_PIM_REGISTER) {
logit(LOG_INFO, 0, "Sending unicast: len = %d, frag %zd, mtu %zd, to %s",
len, frag, mtu, inet_fmt(ip->ip_dst.s_addr, source, sizeof(source)));
dump_frame(NULL, buf, len);
}
while (sendto(pim_socket, buf, len, 0, dst, salen) < 0) {
switch (errno) {
case EINTR:
continue; /* Received signal, retry syscall. */
case ENETDOWN:
check_vif_state();
return -1;
case EMSGSIZE:
{
/* split it in half and recursively send each half */
size_t hdrsize = sizeof(struct ip);
size_t newlen1 = ((len - hdrsize) / 2) & 0xFFF8; /* 8 byte boundary */
size_t sendlen = newlen1 + hdrsize;
size_t offset = ntohs(ip->ip_off);
/* send first half */
ip->ip_len = htons(sendlen);
ip->ip_off = htons(offset | IP_MF);
if (send_frame(buf, sendlen, 1, newlen1, dst, salen) == 0) {
/* send second half */
struct ip *ip2 = (struct ip *)(buf + newlen1);
size_t newlen2 = len - sendlen;
sendlen = newlen2 + hdrsize;
memcpy(ip2, ip, hdrsize);
ip2->ip_len = htons(sendlen);
ip2->ip_off = htons(offset + (newlen1 >> 3)); /* keep flgs */
return send_frame((char *)ip2, sendlen, 1, newlen2, dst, salen);
}
return -1;
}
default:
logit(LOG_WARNING, errno, "sendto from %s to %s",
inet_fmt(ip->ip_src.s_addr, source, sizeof(source)),
inet_fmt(ip->ip_dst.s_addr, dest, sizeof(dest)));
return -1;
}
}
return 0;
}
#else
/*
* send unicast register frames
* Version: Joachim Nilsson
* Staus: Does not work (yet!)
* Design: Fragment IP frames when the frame length exceeds the MTU
* reported from the interface. Optimizes for less fragments
* and fewer syscalls, should get better network utilization.
* Can be easily modified to use the PMTU instead.
*
* Feel free to debug this version and submit your patches -- it should work! --Joachim
*/
static int send_frame(char *buf, size_t len, size_t frag, size_t mtu, struct sockaddr *dst, size_t salen)
{
struct ip *next, *ip = (struct ip *)buf;
size_t xferlen, offset;
char source[20], dest[20];
if (!mtu)
mtu = IP_MSS;
if (len > mtu)
xferlen = (mtu - sizeof(struct ip)) & 0xFFF8;
else
xferlen = len;
offset = (ntohs(ip->ip_off) & IP_OFFMASK) + (frag >> 3);
ip->ip_off = offset;
len = len - xferlen;
if (len)
ip->ip_off |= IP_MF;
ip->ip_off = htons(ip->ip_off);
ip->ip_len = htons(xferlen);
IF_DEBUG(DEBUG_PIM_REGISTER) {
logit(LOG_INFO, 0, "Sending %-4d bytes %sunicast (MTU %-4d, offset %zd) to %s",
xferlen, len ? "fragmented " : "", mtu, offset,
inet_fmt(ip->ip_dst.s_addr, source, sizeof(source)));
dump_frame(NULL, buf, xferlen);
}
/* send first fragment */
while (sendto(pim_socket, ip, xferlen, 0, dst, salen) < 0) {
switch (errno) {
case EINTR:
continue; /* Received signal, retry syscall. */
case ENETDOWN:
check_vif_state();
return -1;
case EMSGSIZE:
if (mtu > IP_MSS)
return send_frame((char *)ip, xferlen, frag, IP_MSS, dst, salen);
/* fall through */
default:
return -1;
}
}
/* send reminder */
if (len) {
size_t hdrsz = sizeof(struct ip);
/* Update data pointers */
next = (struct ip *)(buf + xferlen - hdrsz);
memcpy(next, ip, hdrsz);
return send_frame((char *)next, len + hdrsz, xferlen, mtu, dst, salen);
}
return 0;
}
#endif
/**
* Local Variables:
* version-control: t
* indent-tabs-mode: t
* c-file-style: "ellemtel"
* c-basic-offset: 4
* End:
*/
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