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TP-Link_Archer-XR500v/EN7526G_3.18Kernel_SDK/apps/public/radvd-1.5/process.c
2024-07-22 01:58:46 -03:00

474 lines
12 KiB
C
Executable File

/*
* $Id: //BBN_Linux/Branch/Branch_for_Rel_TP_ASEAN_20161216/tclinux_phoenix/apps/public/radvd-1.5/process.c#1 $
*
* Authors:
* Pedro Roque <roque@di.fc.ul.pt>
* Lars Fenneberg <lf@elemental.net>
*
* This software is Copyright 1996,1997 by the above mentioned author(s),
* All Rights Reserved.
*
* The license which is distributed with this software in the file COPYRIGHT
* applies to this software. If your distribution is missing this file, you
* may request it from <pekkas@netcore.fi>.
*
*/
#include <config.h>
#include <includes.h>
#include <radvd.h>
static void process_rs(int, struct Interface *, unsigned char *msg,
int len, struct sockaddr_in6 *);
static void process_ra(struct Interface *, unsigned char *msg, int len,
struct sockaddr_in6 *);
static int addr_match(struct in6_addr *a1, struct in6_addr *a2,
int prefixlen);
void
process(int sock, struct Interface *ifacel, unsigned char *msg, int len,
struct sockaddr_in6 *addr, struct in6_pktinfo *pkt_info, int hoplimit)
{
struct Interface *iface;
struct icmp6_hdr *icmph;
char addr_str[INET6_ADDRSTRLEN];
//printf("radvd:Enter process");
if ( ! pkt_info )
{
flog(LOG_WARNING, "received packet with no pkt_info!" );
return;
}
/*
* can this happen?
*/
if (len < sizeof(struct icmp6_hdr))
{
flog(LOG_WARNING, "received icmpv6 packet with invalid length: %d",
len);
return;
}
icmph = (struct icmp6_hdr *) msg;
//printf("radvd:RS=%d,RA=%d",ND_ROUTER_SOLICIT,ND_ROUTER_ADVERT);
//printf("radvd:%d\n",icmph->icmp6_type);
if (icmph->icmp6_type != ND_ROUTER_SOLICIT &&
icmph->icmp6_type != ND_ROUTER_ADVERT)
{
/*
* We just want to listen to RSs and RAs
*/
flog(LOG_ERR, "icmpv6 filter failed");
return;
}
if (icmph->icmp6_type == ND_ROUTER_ADVERT)
{
if (len < sizeof(struct nd_router_advert)) {
flog(LOG_WARNING, "received icmpv6 RA packet with invalid length: %d",
len);
return;
}
if (!IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr)) {
flog(LOG_WARNING, "received icmpv6 RA packet with non-linklocal source address");
return;
}
}
if (icmph->icmp6_type == ND_ROUTER_SOLICIT)
{
//printf("radvd:rcv rs:check len\n");
if (len < sizeof(struct nd_router_solicit)) {
flog(LOG_WARNING, "received icmpv6 RS packet with invalid length: %d",
len);
return;
}
}
if (icmph->icmp6_code != 0)
{
flog(LOG_WARNING, "received icmpv6 RS/RA packet with invalid code: %d",
icmph->icmp6_code);
return;
}
//printf("radvd:process 11\n");
dlog(LOG_DEBUG, 4, "if_index %u", pkt_info->ipi6_ifindex);
/* get iface by received if_index */
for (iface = ifacel; iface; iface=iface->next)
{
if (iface->if_index == pkt_info->ipi6_ifindex)
{
break;
}
}
if (iface == NULL)
{
dlog(LOG_DEBUG, 2, "received packet from unknown interface: %d",
pkt_info->ipi6_ifindex);
return;
}
if (hoplimit != 255)
{
print_addr(&addr->sin6_addr, addr_str);
flog(LOG_WARNING, "received RS or RA with invalid hoplimit %d from %s",
hoplimit, addr_str);
return;
}
if (!iface->AdvSendAdvert)
{
dlog(LOG_DEBUG, 2, "AdvSendAdvert is off for %s", iface->Name);
return;
}
//printf("radvd:proc 22\n");
dlog(LOG_DEBUG, 4, "found Interface: %s", iface->Name);
if (icmph->icmp6_type == ND_ROUTER_SOLICIT)
{
process_rs(sock, iface, msg, len, addr);
}
else if (icmph->icmp6_type == ND_ROUTER_ADVERT)
{
process_ra(iface, msg, len, addr);
}
}
static void
process_rs(int sock, struct Interface *iface, unsigned char *msg, int len,
struct sockaddr_in6 *addr)
{
double delay;
double next;
struct timeval tv;
uint8_t *opt_str;
/* validation */
len -= sizeof(struct nd_router_solicit);
opt_str = (uint8_t *)(msg + sizeof(struct nd_router_solicit));
//printf("radvd:proc_rs enter!len=%d\n",len);
while (len > 0)
{
int optlen;
if (len < 2)
{
flog(LOG_WARNING, "trailing garbage in RS");
//printf("radvd:return1!!!\n");
return;
}
optlen = (opt_str[1] << 3);
if (optlen == 0)
{
//printf("radvd:return2!!!\n");
flog(LOG_WARNING, "zero length option in RS");
return;
}
else if (optlen > len)
{
// printf("radvd:return3!!!\n");
flog(LOG_WARNING, "option length greater than total length in RS");
return;
}
if (*opt_str == ND_OPT_SOURCE_LINKADDR &&
IN6_IS_ADDR_UNSPECIFIED(&addr->sin6_addr)) {
flog(LOG_WARNING, "received icmpv6 RS packet with unspecified source address and there is a lladdr option");
printf("radvd:received icmpv6 return!!!\n");
return;
}
len -= optlen;
opt_str += optlen;
}
// printf("radvd:proc_rs_11\n");
gettimeofday(&tv, NULL);
delay = MAX_RA_DELAY_TIME*rand()/(RAND_MAX+1.0);
dlog(LOG_DEBUG, 3, "random mdelay for %s: %.2f", iface->Name, delay);
if (iface->UnicastOnly) {
// printf("radvd:proc_rs_22\n");
mdelay(delay);
send_ra_forall(sock, iface, &addr->sin6_addr);
}
else if ((tv.tv_sec + tv.tv_usec / 1000000.0) - (iface->last_multicast_sec +
iface->last_multicast_usec / 1000000.0) < iface->MinDelayBetweenRAs) {
/* last RA was sent only a few moments ago, don't send another immediately */
// printf("radvd:proc_rs_33\n");
clear_timer(&iface->tm);
next = iface->MinDelayBetweenRAs - (tv.tv_sec + tv.tv_usec / 1000000.0) +
(iface->last_multicast_sec + iface->last_multicast_usec / 1000000.0) + delay/1000.0;
set_timer(&iface->tm, next);
}
else {
/* no RA sent in a while, send an immediate multicast reply */
// printf("radvd:ps_444\n");
clear_timer(&iface->tm);
if (send_ra_forall(sock, iface, NULL) == 0) {
next = rand_between(iface->MinRtrAdvInterval, iface->MaxRtrAdvInterval);
set_timer(&iface->tm, next);
}
}
}
/*
* check router advertisements according to RFC 4861, 6.2.7
*/
static void
process_ra(struct Interface *iface, unsigned char *msg, int len,
struct sockaddr_in6 *addr)
{
struct nd_router_advert *radvert;
char addr_str[INET6_ADDRSTRLEN];
uint8_t *opt_str;
print_addr(&addr->sin6_addr, addr_str);
radvert = (struct nd_router_advert *) msg;
if ((radvert->nd_ra_curhoplimit && iface->AdvCurHopLimit) &&
(radvert->nd_ra_curhoplimit != iface->AdvCurHopLimit))
{
flog(LOG_WARNING, "our AdvCurHopLimit on %s doesn't agree with %s",
iface->Name, addr_str);
}
if ((radvert->nd_ra_flags_reserved & ND_RA_FLAG_MANAGED) && !iface->AdvManagedFlag)
{
flog(LOG_WARNING, "our AdvManagedFlag on %s doesn't agree with %s",
iface->Name, addr_str);
}
if ((radvert->nd_ra_flags_reserved & ND_RA_FLAG_OTHER) && !iface->AdvOtherConfigFlag)
{
flog(LOG_WARNING, "our AdvOtherConfigFlag on %s doesn't agree with %s",
iface->Name, addr_str);
}
/* note: we don't check the default router preference here, because they're likely different */
if ((radvert->nd_ra_reachable && iface->AdvReachableTime) &&
(ntohl(radvert->nd_ra_reachable) != iface->AdvReachableTime))
{
flog(LOG_WARNING, "our AdvReachableTime on %s doesn't agree with %s",
iface->Name, addr_str);
}
if ((radvert->nd_ra_retransmit && iface->AdvRetransTimer) &&
(ntohl(radvert->nd_ra_retransmit) != iface->AdvRetransTimer))
{
flog(LOG_WARNING, "our AdvRetransTimer on %s doesn't agree with %s",
iface->Name, addr_str);
}
len -= sizeof(struct nd_router_advert);
if (len == 0)
return;
opt_str = (uint8_t *)(msg + sizeof(struct nd_router_advert));
while (len > 0)
{
int optlen;
struct nd_opt_prefix_info *pinfo;
struct nd_opt_rdnss_info_local *rdnssinfo;
struct nd_opt_mtu *mtu;
struct AdvPrefix *prefix;
struct AdvRDNSS *rdnss;
char prefix_str[INET6_ADDRSTRLEN];
char rdnss_str[INET6_ADDRSTRLEN];
uint32_t preferred, valid, count;
if (len < 2)
{
flog(LOG_ERR, "trailing garbage in RA on %s from %s",
iface->Name, addr_str);
break;
}
optlen = (opt_str[1] << 3);
if (optlen == 0)
{
flog(LOG_ERR, "zero length option in RA on %s from %s",
iface->Name, addr_str);
break;
}
else if (optlen > len)
{
flog(LOG_ERR, "option length greater than total"
" length in RA on %s from %s",
iface->Name, addr_str);
break;
}
switch (*opt_str)
{
case ND_OPT_MTU:
mtu = (struct nd_opt_mtu *)opt_str;
if (iface->AdvLinkMTU && (ntohl(mtu->nd_opt_mtu_mtu) != iface->AdvLinkMTU))
{
flog(LOG_WARNING, "our AdvLinkMTU on %s doesn't agree with %s",
iface->Name, addr_str);
}
break;
case ND_OPT_PREFIX_INFORMATION:
pinfo = (struct nd_opt_prefix_info *) opt_str;
preferred = ntohl(pinfo->nd_opt_pi_preferred_time);
valid = ntohl(pinfo->nd_opt_pi_valid_time);
prefix = iface->AdvPrefixList;
while (prefix)
{
if (prefix->enabled &&
(prefix->PrefixLen == pinfo->nd_opt_pi_prefix_len) &&
addr_match(&prefix->Prefix, &pinfo->nd_opt_pi_prefix,
prefix->PrefixLen))
{
print_addr(&prefix->Prefix, prefix_str);
if (valid != prefix->AdvValidLifetime)
{
flog(LOG_WARNING, "our AdvValidLifetime on"
" %s for %s doesn't agree with %s",
iface->Name,
prefix_str,
addr_str
);
}
if (preferred != prefix->AdvPreferredLifetime)
{
flog(LOG_WARNING, "our AdvPreferredLifetime on"
" %s for %s doesn't agree with %s",
iface->Name,
prefix_str,
addr_str
);
}
}
prefix = prefix->next;
}
break;
case ND_OPT_ROUTE_INFORMATION:
/* not checked: these will very likely vary a lot */
break;
case ND_OPT_SOURCE_LINKADDR:
/* not checked */
break;
case ND_OPT_TARGET_LINKADDR:
case ND_OPT_REDIRECTED_HEADER:
flog(LOG_ERR, "invalid option %d in RA on %s from %s",
(int)*opt_str, iface->Name, addr_str);
break;
/* Mobile IPv6 extensions */
case ND_OPT_RTR_ADV_INTERVAL:
case ND_OPT_HOME_AGENT_INFO:
/* not checked */
break;
case ND_OPT_RDNSS_INFORMATION:
rdnssinfo = (struct nd_opt_rdnss_info_local *) opt_str;
count = rdnssinfo->nd_opt_rdnssi_len;
/* Check the RNDSS addresses received */
switch (count) {
case 7:
rdnss = iface->AdvRDNSSList;
if (!check_rdnss_presence(rdnss, &rdnssinfo->nd_opt_rdnssi_addr3 )) {
/* no match found in iface->AdvRDNSSList */
print_addr(&rdnssinfo->nd_opt_rdnssi_addr3, rdnss_str);
flog(LOG_WARNING, "RDNSS address %s received on %s from %s is not advertised by us",
rdnss_str, iface->Name, addr_str);
}
/* FALLTHROUGH */
case 5:
rdnss = iface->AdvRDNSSList;
if (!check_rdnss_presence(rdnss, &rdnssinfo->nd_opt_rdnssi_addr2 )) {
/* no match found in iface->AdvRDNSSList */
print_addr(&rdnssinfo->nd_opt_rdnssi_addr2, rdnss_str);
flog(LOG_WARNING, "RDNSS address %s received on %s from %s is not advertised by us",
rdnss_str, iface->Name, addr_str);
}
/* FALLTHROUGH */
case 3:
rdnss = iface->AdvRDNSSList;
if (!check_rdnss_presence(rdnss, &rdnssinfo->nd_opt_rdnssi_addr1 )) {
/* no match found in iface->AdvRDNSSList */
print_addr(&rdnssinfo->nd_opt_rdnssi_addr1, rdnss_str);
flog(LOG_WARNING, "RDNSS address %s received on %s from %s is not advertised by us",
rdnss_str, iface->Name, addr_str);
}
break;
default:
flog(LOG_ERR, "invalid len %i in RDNSS option on %s from %s",
count, iface->Name, addr_str);
}
break;
default:
dlog(LOG_DEBUG, 1, "unknown option %d in RA on %s from %s",
(int)*opt_str, iface->Name, addr_str);
break;
}
len -= optlen;
opt_str += optlen;
}
}
static int
addr_match(struct in6_addr *a1, struct in6_addr *a2, int prefixlen)
{
unsigned int pdw;
unsigned int pbi;
pdw = prefixlen >> 0x05; /* num of whole uint32_t in prefix */
pbi = prefixlen & 0x1f; /* num of bits in incomplete uint32_t in prefix */
if (pdw)
{
if (memcmp(a1, a2, pdw << 2))
return 0;
}
if (pbi)
{
uint32_t w1, w2;
uint32_t mask;
w1 = *((uint32_t *)a1 + pdw);
w2 = *((uint32_t *)a2 + pdw);
mask = htonl(((uint32_t) 0xffffffff) << (0x20 - pbi));
if ((w1 ^ w2) & mask)
return 0;
}
return 1;
}