FreeBSD-5.3/usr.sbin/ppp/ip.c
/*-
* Copyright (c) 1996 - 2001 Brian Somers <brian@Awfulhak.org>
* based on work by Toshiharu OHNO <tony-o@iij.ad.jp>
* Internet Initiative Japan, Inc (IIJ)
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* $FreeBSD: src/usr.sbin/ppp/ip.c,v 1.101 2004/05/13 09:03:00 dds Exp $
*/
#include <sys/param.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#ifndef NOINET6
#include <netinet/icmp6.h>
#include <netinet/ip6.h>
#endif
#include <netinet/ip_icmp.h>
#include <netinet/udp.h>
#include <netinet/tcp.h>
#include <sys/un.h>
#include <errno.h>
#include <netdb.h>
#include <stdio.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>
#include "layer.h"
#include "proto.h"
#include "mbuf.h"
#include "log.h"
#include "defs.h"
#include "timer.h"
#include "fsm.h"
#include "lqr.h"
#include "hdlc.h"
#include "throughput.h"
#include "iplist.h"
#include "slcompress.h"
#include "ncpaddr.h"
#include "ip.h"
#include "ipcp.h"
#include "filter.h"
#include "descriptor.h"
#include "lcp.h"
#include "ccp.h"
#include "link.h"
#include "mp.h"
#ifndef NORADIUS
#include "radius.h"
#endif
#include "ipv6cp.h"
#include "ncp.h"
#include "bundle.h"
#include "tun.h"
#define OPCODE_QUERY 0
#define OPCODE_IQUERY 1
#define OPCODE_STATUS 2
struct dns_header {
u_short id;
unsigned qr : 1;
unsigned opcode : 4;
unsigned aa : 1;
unsigned tc : 1;
unsigned rd : 1;
unsigned ra : 1;
unsigned z : 3;
unsigned rcode : 4;
u_short qdcount;
u_short ancount;
u_short nscount;
u_short arcount;
};
static const char *
dns_Qclass2Txt(u_short qclass)
{
static char failure[6];
struct {
u_short id;
const char *txt;
} qtxt[] = {
/* rfc1035 */
{ 1, "IN" }, { 2, "CS" }, { 3, "CH" }, { 4, "HS" }, { 255, "*" }
};
int f;
for (f = 0; f < sizeof qtxt / sizeof *qtxt; f++)
if (qtxt[f].id == qclass)
return qtxt[f].txt;
return HexStr(qclass, failure, sizeof failure);
}
static const char *
dns_Qtype2Txt(u_short qtype)
{
static char failure[6];
struct {
u_short id;
const char *txt;
} qtxt[] = {
/* rfc1035/rfc1700 */
{ 1, "A" }, { 2, "NS" }, { 3, "MD" }, { 4, "MF" }, { 5, "CNAME" },
{ 6, "SOA" }, { 7, "MB" }, { 8, "MG" }, { 9, "MR" }, { 10, "NULL" },
{ 11, "WKS" }, { 12, "PTR" }, { 13, "HINFO" }, { 14, "MINFO" },
{ 15, "MX" }, { 16, "TXT" }, { 17, "RP" }, { 18, "AFSDB" },
{ 19, "X25" }, { 20, "ISDN" }, { 21, "RT" }, { 22, "NSAP" },
{ 23, "NSAP-PTR" }, { 24, "SIG" }, { 25, "KEY" }, { 26, "PX" },
{ 27, "GPOS" }, { 28, "AAAA" }, { 252, "AXFR" }, { 253, "MAILB" },
{ 254, "MAILA" }, { 255, "*" }
};
int f;
for (f = 0; f < sizeof qtxt / sizeof *qtxt; f++)
if (qtxt[f].id == qtype)
return qtxt[f].txt;
return HexStr(qtype, failure, sizeof failure);
}
static __inline int
PortMatch(int op, u_short pport, u_short rport)
{
switch (op) {
case OP_EQ:
return pport == rport;
case OP_GT:
return pport > rport;
case OP_LT:
return pport < rport;
default:
return 0;
}
}
/*
* Return a text string representing the cproto protocol number.
*
* The purpose of this routine is calculate this result, for
* the many times it is needed in FilterCheck, only on demand
* (i.e. when the corresponding logging functions are invoked).
*
* This optimization saves, over the previous implementation, which
* calculated prototxt at the beginning of FilterCheck, an
* open/read/close system call sequence per packet, approximately
* halving the ppp system overhead and reducing the overall (u + s)
* time by 38%.
*
* The caching performed here is just a side effect.
*/
static const char *
prototxt(int cproto)
{
static int oproto = -1;
static char protobuff[16] = "-1";
struct protoent *pe;
if (cproto == oproto)
return protobuff;
if ((pe = getprotobynumber(cproto)) == NULL)
snprintf(protobuff, sizeof protobuff, "%d", cproto);
else
snprintf(protobuff, sizeof protobuff, "%s", pe->p_name);
oproto = cproto;
return (protobuff);
}
/*
* Check a packet against the given filter
* Returns 0 to accept the packet, non-zero to drop the packet.
* If psecs is not NULL, populate it with the timeout associated
* with the filter rule matched.
*
* If filtering is enabled, the initial fragment of a datagram must
* contain the complete protocol header, and subsequent fragments
* must not attempt to over-write it.
*
* One (and only one) of pip or pip6 must be set.
*/
int
FilterCheck(const unsigned char *packet, u_int32_t family,
const struct filter *filter, unsigned *psecs)
{
int gotinfo; /* true if IP payload decoded */
int cproto; /* IPPROTO_* protocol number if (gotinfo) */
int estab, syn, finrst; /* TCP state flags if (gotinfo) */
u_short sport, dport; /* src, dest port from packet if (gotinfo) */
int n; /* filter rule to process */
int len; /* bytes used in dbuff */
int didname; /* true if filter header printed */
int match; /* true if condition matched */
int mindata; /* minimum data size or zero */
const struct filterent *fp = filter->rule;
char dbuff[100], dstip[16];
struct ncpaddr srcaddr, dstaddr;
const char *payload; /* IP payload */
int datalen; /* IP datagram length */
if (fp->f_action == A_NONE)
return 0; /* No rule is given. Permit this packet */
#ifndef NOINET6
if (family == AF_INET6) {
const struct ip6_hdr *pip6 = (const struct ip6_hdr *)packet;
ncpaddr_setip6(&srcaddr, &pip6->ip6_src);
ncpaddr_setip6(&dstaddr, &pip6->ip6_dst);
datalen = ntohs(pip6->ip6_plen);
payload = packet + sizeof *pip6;
cproto = pip6->ip6_nxt;
} else
#endif
{
/*
* Deny any packet fragment that tries to over-write the header.
* Since we no longer have the real header available, punt on the
* largest normal header - 20 bytes for TCP without options, rounded
* up to the next possible fragment boundary. Since the smallest
* `legal' MTU is 576, and the smallest recommended MTU is 296, any
* fragmentation within this range is dubious at best
*/
const struct ip *pip = (const struct ip *)packet;
len = ntohs(pip->ip_off) & IP_OFFMASK; /* fragment offset */
if (len > 0) { /* Not first fragment within datagram */
if (len < (24 >> 3)) { /* don't allow fragment to over-write header */
log_Printf(LogFILTER, " error: illegal header\n");
return 1;
}
/* permit fragments on in and out filter */
if (!filter->fragok) {
log_Printf(LogFILTER, " error: illegal fragmentation\n");
return 1;
} else
return 0;
}
ncpaddr_setip4(&srcaddr, pip->ip_src);
ncpaddr_setip4(&dstaddr, pip->ip_dst);
datalen = ntohs(pip->ip_len) - (pip->ip_hl << 2);
payload = packet + (pip->ip_hl << 2);
cproto = pip->ip_p;
}
gotinfo = estab = syn = finrst = didname = 0;
sport = dport = 0;
for (n = 0; n < MAXFILTERS; ) {
if (fp->f_action == A_NONE) {
n++;
fp++;
continue;
}
if (!didname) {
log_Printf(LogDEBUG, "%s filter:\n", filter->name);
didname = 1;
}
match = 0;
if ((ncprange_family(&fp->f_src) == AF_UNSPEC ||
ncprange_contains(&fp->f_src, &srcaddr)) &&
(ncprange_family(&fp->f_dst) == AF_UNSPEC ||
ncprange_contains(&fp->f_dst, &dstaddr))) {
if (fp->f_proto != 0) {
if (!gotinfo) {
const struct tcphdr *th;
const struct udphdr *uh;
const struct icmp *ih;
#ifndef NOINET6
const struct icmp6_hdr *ih6;
#endif
mindata = 0;
sport = dport = 0;
estab = syn = finrst = -1;
switch (cproto) {
case IPPROTO_ICMP:
mindata = 8; /* ICMP must be at least 8 octets */
ih = (const struct icmp *)payload;
sport = ih->icmp_type;
if (log_IsKept(LogDEBUG))
snprintf(dbuff, sizeof dbuff, "sport = %d", sport);
break;
#ifndef NOINET6
case IPPROTO_ICMPV6:
mindata = 8; /* ICMP must be at least 8 octets */
ih6 = (const struct icmp6_hdr *)payload;
sport = ih6->icmp6_type;
if (log_IsKept(LogDEBUG))
snprintf(dbuff, sizeof dbuff, "sport = %d", sport);
break;
#endif
case IPPROTO_IGMP:
mindata = 8; /* IGMP uses 8-octet messages */
break;
#ifdef IPPROTO_GRE
case IPPROTO_GRE:
mindata = 2; /* GRE uses 2-octet+ messages */
break;
#endif
#ifdef IPPROTO_OSPFIGP
case IPPROTO_OSPFIGP:
mindata = 8; /* IGMP uses 8-octet messages */
break;
#endif
#ifndef NOINET6
case IPPROTO_IPV6:
mindata = 20; /* RFC2893 Section 3.5: 5 * 32bit words */
break;
#endif
case IPPROTO_UDP:
mindata = 8; /* UDP header is 8 octets */
uh = (const struct udphdr *)payload;
sport = ntohs(uh->uh_sport);
dport = ntohs(uh->uh_dport);
if (log_IsKept(LogDEBUG))
snprintf(dbuff, sizeof dbuff, "sport = %d, dport = %d",
sport, dport);
break;
case IPPROTO_TCP:
th = (const struct tcphdr *)payload;
/*
* TCP headers are variable length. The following code
* ensures that the TCP header length isn't de-referenced if
* the datagram is too short
*/
if (datalen < 20 || datalen < (th->th_off << 2)) {
log_Printf(LogFILTER, " error: TCP header incorrect\n");
return 1;
}
sport = ntohs(th->th_sport);
dport = ntohs(th->th_dport);
estab = (th->th_flags & TH_ACK);
syn = (th->th_flags & TH_SYN);
finrst = (th->th_flags & (TH_FIN|TH_RST));
if (log_IsKept(LogDEBUG)) {
if (!estab)
snprintf(dbuff, sizeof dbuff,
"flags = %02x, sport = %d, dport = %d",
th->th_flags, sport, dport);
else
*dbuff = '\0';
}
break;
default:
break;
}
if (datalen < mindata) {
log_Printf(LogFILTER, " error: proto %s must be at least"
" %d octets\n", prototxt(cproto), mindata);
return 1;
}
if (log_IsKept(LogDEBUG)) {
if (estab != -1) {
len = strlen(dbuff);
snprintf(dbuff + len, sizeof dbuff - len,
", estab = %d, syn = %d, finrst = %d",
estab, syn, finrst);
}
log_Printf(LogDEBUG, " Filter: proto = %s, %s\n",
prototxt(cproto), dbuff);
}
gotinfo = 1;
}
if (log_IsKept(LogDEBUG)) {
if (fp->f_srcop != OP_NONE) {
snprintf(dbuff, sizeof dbuff, ", src %s %d",
filter_Op2Nam(fp->f_srcop), fp->f_srcport);
len = strlen(dbuff);
} else
len = 0;
if (fp->f_dstop != OP_NONE) {
snprintf(dbuff + len, sizeof dbuff - len,
", dst %s %d", filter_Op2Nam(fp->f_dstop),
fp->f_dstport);
} else if (!len)
*dbuff = '\0';
log_Printf(LogDEBUG, " rule = %d: Address match, "
"check against proto %d%s, action = %s\n",
n, fp->f_proto, dbuff, filter_Action2Nam(fp->f_action));
}
if (cproto == fp->f_proto) {
if ((fp->f_srcop == OP_NONE ||
PortMatch(fp->f_srcop, sport, fp->f_srcport)) &&
(fp->f_dstop == OP_NONE ||
PortMatch(fp->f_dstop, dport, fp->f_dstport)) &&
(fp->f_estab == 0 || estab) &&
(fp->f_syn == 0 || syn) &&
(fp->f_finrst == 0 || finrst)) {
match = 1;
}
}
} else {
/* Address is matched and no protocol specified. Make a decision. */
log_Printf(LogDEBUG, " rule = %d: Address match, action = %s\n", n,
filter_Action2Nam(fp->f_action));
match = 1;
}
} else
log_Printf(LogDEBUG, " rule = %d: Address mismatch\n", n);
if (match != fp->f_invert) {
/* Take specified action */
if (fp->f_action < A_NONE)
fp = &filter->rule[n = fp->f_action];
else {
if (fp->f_action == A_PERMIT) {
if (psecs != NULL)
*psecs = fp->timeout;
if (strcmp(filter->name, "DIAL") == 0) {
/* If dial filter then even print out accept packets */
if (log_IsKept(LogFILTER)) {
snprintf(dstip, sizeof dstip, "%s", ncpaddr_ntoa(&dstaddr));
log_Printf(LogFILTER, "%sbound rule = %d accept %s "
"src = %s:%d dst = %s:%d\n", filter->name, n,
prototxt(cproto), ncpaddr_ntoa(&srcaddr), sport,
dstip, dport);
}
}
return 0;
} else {
if (log_IsKept(LogFILTER)) {
snprintf(dstip, sizeof dstip, "%s", ncpaddr_ntoa(&dstaddr));
log_Printf(LogFILTER,
"%sbound rule = %d deny %s src = %s/%d dst = %s/%d\n",
filter->name, n, prototxt(cproto),
ncpaddr_ntoa(&srcaddr), sport, dstip, dport);
}
return 1;
} /* Explict match. Deny this packet */
}
} else {
n++;
fp++;
}
}
if (log_IsKept(LogFILTER)) {
snprintf(dstip, sizeof dstip, "%s", ncpaddr_ntoa(&dstaddr));
log_Printf(LogFILTER,
"%sbound rule = implicit deny %s src = %s/%d dst = %s/%d\n",
filter->name, prototxt(cproto), ncpaddr_ntoa(&srcaddr),
sport, dstip, dport);
}
return 1; /* No rule matched, deny this packet */
}
static void
ip_LogDNS(const struct udphdr *uh, const char *direction)
{
struct dns_header header;
const u_short *pktptr;
const u_char *ptr;
u_short *hptr, tmp;
int len;
ptr = (const char *)uh + sizeof *uh;
len = ntohs(uh->uh_ulen) - sizeof *uh;
if (len < sizeof header + 5) /* rfc1024 */
return;
pktptr = (const u_short *)ptr;
hptr = (u_short *)&header;
ptr += sizeof header;
len -= sizeof header;
while (pktptr < (const u_short *)ptr) {
*hptr++ = ntohs(*pktptr); /* Careful of macro side-effects ! */
pktptr++;
}
if (header.opcode == OPCODE_QUERY && header.qr == 0) {
/* rfc1035 */
char namewithdot[MAXHOSTNAMELEN + 1], *n;
const char *qtype, *qclass;
const u_char *end;
n = namewithdot;
end = ptr + len - 4;
if (end - ptr >= sizeof namewithdot)
end = ptr + sizeof namewithdot - 1;
while (ptr < end) {
len = *ptr++;
if (len > end - ptr)
len = end - ptr;
if (n != namewithdot)
*n++ = '.';
memcpy(n, ptr, len);
ptr += len;
n += len;
}
*n = '\0';
if (log_IsKept(LogDNS)) {
memcpy(&tmp, end, sizeof tmp);
qtype = dns_Qtype2Txt(ntohs(tmp));
memcpy(&tmp, end + 2, sizeof tmp);
qclass = dns_Qclass2Txt(ntohs(tmp));
log_Printf(LogDNS, "%sbound query %s %s %s\n",
direction, qclass, qtype, namewithdot);
}
}
}
/*
* Check if the given packet matches the given filter.
* One of pip or pip6 must be set.
*/
int
PacketCheck(struct bundle *bundle, u_int32_t family,
const unsigned char *packet, int nb, struct filter *filter,
const char *prefix, unsigned *psecs)
{
static const char *const TcpFlags[] = {
"FIN", "SYN", "RST", "PSH", "ACK", "URG"
};
const struct tcphdr *th;
const struct udphdr *uh;
const struct icmp *icmph;
#ifndef NOINET6
const struct icmp6_hdr *icmp6h;
#endif
const unsigned char *payload;
struct ncpaddr srcaddr, dstaddr;
int cproto, mask, len, n, pri, logit, loglen, result;
char logbuf[200];
int datalen, frag;
u_char tos;
logit = (log_IsKept(LogTCPIP) || log_IsKept(LogDNS)) &&
(!filter || filter->logok);
loglen = 0;
pri = 0;
#ifndef NOINET6
if (family == AF_INET6) {
const struct ip6_hdr *pip6 = (const struct ip6_hdr *)packet;
ncpaddr_setip6(&srcaddr, &pip6->ip6_src);
ncpaddr_setip6(&dstaddr, &pip6->ip6_dst);
datalen = ntohs(pip6->ip6_plen);
payload = packet + sizeof *pip6;
cproto = pip6->ip6_nxt;
tos = 0; /* XXX: pip6->ip6_vfc >> 4 ? */
frag = 0; /* XXX: ??? */
} else
#endif
{
const struct ip *pip = (const struct ip *)packet;
ncpaddr_setip4(&srcaddr, pip->ip_src);
ncpaddr_setip4(&dstaddr, pip->ip_dst);
datalen = ntohs(pip->ip_len) - (pip->ip_hl << 2);
payload = packet + (pip->ip_hl << 2);
cproto = pip->ip_p;
tos = pip->ip_tos;
frag = ntohs(pip->ip_off) & IP_OFFMASK;
}
uh = NULL;
if (logit && loglen < sizeof logbuf) {
if (prefix)
snprintf(logbuf + loglen, sizeof logbuf - loglen, "%s", prefix);
else if (filter)
snprintf(logbuf + loglen, sizeof logbuf - loglen, "%s ", filter->name);
else
snprintf(logbuf + loglen, sizeof logbuf - loglen, " ");
loglen += strlen(logbuf + loglen);
}
switch (cproto) {
case IPPROTO_ICMP:
if (logit && loglen < sizeof logbuf) {
len = datalen - sizeof *icmph;
icmph = (const struct icmp *)payload;
snprintf(logbuf + loglen, sizeof logbuf - loglen,
"ICMP: %s:%d ---> ", ncpaddr_ntoa(&srcaddr), icmph->icmp_type);
loglen += strlen(logbuf + loglen);
snprintf(logbuf + loglen, sizeof logbuf - loglen,
"%s (%d/%d)", ncpaddr_ntoa(&dstaddr), len, nb);
loglen += strlen(logbuf + loglen);
}
break;
#ifndef NOINET6
case IPPROTO_ICMPV6:
if (logit && loglen < sizeof logbuf) {
len = datalen - sizeof *icmp6h;
icmp6h = (const struct icmp6_hdr *)payload;
snprintf(logbuf + loglen, sizeof logbuf - loglen,
"ICMP: %s:%d ---> ", ncpaddr_ntoa(&srcaddr), icmp6h->icmp6_type);
loglen += strlen(logbuf + loglen);
snprintf(logbuf + loglen, sizeof logbuf - loglen,
"%s (%d/%d)", ncpaddr_ntoa(&dstaddr), len, nb);
loglen += strlen(logbuf + loglen);
}
break;
#endif
case IPPROTO_UDP:
uh = (const struct udphdr *)payload;
if (tos == IPTOS_LOWDELAY && bundle->ncp.cfg.urgent.tos)
pri++;
if (!frag && ncp_IsUrgentUdpPort(&bundle->ncp, ntohs(uh->uh_sport),
ntohs(uh->uh_dport)))
pri++;
if (logit && loglen < sizeof logbuf) {
len = datalen - sizeof *uh;
snprintf(logbuf + loglen, sizeof logbuf - loglen,
"UDP: %s:%d ---> ", ncpaddr_ntoa(&srcaddr), ntohs(uh->uh_sport));
loglen += strlen(logbuf + loglen);
snprintf(logbuf + loglen, sizeof logbuf - loglen,
"%s:%d (%d/%d)", ncpaddr_ntoa(&dstaddr), ntohs(uh->uh_dport),
len, nb);
loglen += strlen(logbuf + loglen);
}
if (Enabled(bundle, OPT_FILTERDECAP) &&
payload[sizeof *uh] == HDLC_ADDR &&
payload[sizeof *uh + 1] == HDLC_UI) {
u_short proto;
const char *type;
memcpy(&proto, payload + sizeof *uh + 2, sizeof proto);
type = NULL;
switch (ntohs(proto)) {
case PROTO_IP:
snprintf(logbuf + loglen, sizeof logbuf - loglen, " contains ");
result = PacketCheck(bundle, AF_INET, payload + sizeof *uh + 4,
nb - (payload - packet) - sizeof *uh - 4, filter,
logbuf, psecs);
if (result != -2)
return result;
type = "IP";
break;
case PROTO_VJUNCOMP: type = "compressed VJ"; break;
case PROTO_VJCOMP: type = "uncompressed VJ"; break;
case PROTO_MP: type = "Multi-link"; break;
case PROTO_ICOMPD: type = "Individual link CCP"; break;
case PROTO_COMPD: type = "CCP"; break;
case PROTO_IPCP: type = "IPCP"; break;
case PROTO_LCP: type = "LCP"; break;
case PROTO_PAP: type = "PAP"; break;
case PROTO_CBCP: type = "CBCP"; break;
case PROTO_LQR: type = "LQR"; break;
case PROTO_CHAP: type = "CHAP"; break;
}
if (type) {
snprintf(logbuf + loglen, sizeof logbuf - loglen,
" - %s data", type);
loglen += strlen(logbuf + loglen);
}
}
break;
#ifdef IPPROTO_GRE
case IPPROTO_GRE:
if (logit && loglen < sizeof logbuf) {
snprintf(logbuf + loglen, sizeof logbuf - loglen,
"GRE: %s ---> ", ncpaddr_ntoa(&srcaddr));
loglen += strlen(logbuf + loglen);
snprintf(logbuf + loglen, sizeof logbuf - loglen,
"%s (%d/%d)", ncpaddr_ntoa(&dstaddr), datalen, nb);
loglen += strlen(logbuf + loglen);
}
break;
#endif
#ifdef IPPROTO_OSPFIGP
case IPPROTO_OSPFIGP:
if (logit && loglen < sizeof logbuf) {
snprintf(logbuf + loglen, sizeof logbuf - loglen,
"OSPF: %s ---> ", ncpaddr_ntoa(&srcaddr));
loglen += strlen(logbuf + loglen);
snprintf(logbuf + loglen, sizeof logbuf - loglen,
"%s (%d/%d)", ncpaddr_ntoa(&dstaddr), datalen, nb);
loglen += strlen(logbuf + loglen);
}
break;
#endif
#ifndef NOINET6
case IPPROTO_IPV6:
if (logit && loglen < sizeof logbuf) {
snprintf(logbuf + loglen, sizeof logbuf - loglen,
"IPv6: %s ---> ", ncpaddr_ntoa(&srcaddr));
loglen += strlen(logbuf + loglen);
snprintf(logbuf + loglen, sizeof logbuf - loglen,
"%s (%d/%d)", ncpaddr_ntoa(&dstaddr), datalen, nb);
loglen += strlen(logbuf + loglen);
}
if (Enabled(bundle, OPT_FILTERDECAP)) {
snprintf(logbuf + loglen, sizeof logbuf - loglen, " contains ");
result = PacketCheck(bundle, AF_INET6, payload, nb - (payload - packet),
filter, logbuf, psecs);
if (result != -2)
return result;
}
break;
#endif
case IPPROTO_IPIP:
if (logit && loglen < sizeof logbuf) {
snprintf(logbuf + loglen, sizeof logbuf - loglen,
"IPIP: %s ---> ", ncpaddr_ntoa(&srcaddr));
loglen += strlen(logbuf + loglen);
snprintf(logbuf + loglen, sizeof logbuf - loglen,
"%s", ncpaddr_ntoa(&dstaddr));
loglen += strlen(logbuf + loglen);
}
if (Enabled(bundle, OPT_FILTERDECAP) &&
((const struct ip *)payload)->ip_v == 4) {
snprintf(logbuf + loglen, sizeof logbuf - loglen, " contains ");
result = PacketCheck(bundle, AF_INET, payload, nb - (payload - packet),
filter, logbuf, psecs);
if (result != -2)
return result;
}
break;
case IPPROTO_ESP:
if (logit && loglen < sizeof logbuf) {
snprintf(logbuf + loglen, sizeof logbuf - loglen,
"ESP: %s ---> ", ncpaddr_ntoa(&srcaddr));
loglen += strlen(logbuf + loglen);
snprintf(logbuf + loglen, sizeof logbuf - loglen, "%s, spi %p",
ncpaddr_ntoa(&dstaddr), payload);
loglen += strlen(logbuf + loglen);
}
break;
case IPPROTO_AH:
if (logit && loglen < sizeof logbuf) {
snprintf(logbuf + loglen, sizeof logbuf - loglen,
"AH: %s ---> ", ncpaddr_ntoa(&srcaddr));
loglen += strlen(logbuf + loglen);
snprintf(logbuf + loglen, sizeof logbuf - loglen, "%s, spi %p",
ncpaddr_ntoa(&dstaddr), payload + sizeof(u_int32_t));
loglen += strlen(logbuf + loglen);
}
break;
case IPPROTO_IGMP:
if (logit && loglen < sizeof logbuf) {
uh = (const struct udphdr *)payload;
snprintf(logbuf + loglen, sizeof logbuf - loglen,
"IGMP: %s:%d ---> ", ncpaddr_ntoa(&srcaddr),
ntohs(uh->uh_sport));
loglen += strlen(logbuf + loglen);
snprintf(logbuf + loglen, sizeof logbuf - loglen,
"%s:%d", ncpaddr_ntoa(&dstaddr), ntohs(uh->uh_dport));
loglen += strlen(logbuf + loglen);
}
break;
case IPPROTO_TCP:
th = (const struct tcphdr *)payload;
if (tos == IPTOS_LOWDELAY && bundle->ncp.cfg.urgent.tos)
pri++;
if (!frag && ncp_IsUrgentTcpPort(&bundle->ncp, ntohs(th->th_sport),
ntohs(th->th_dport)))
pri++;
if (logit && loglen < sizeof logbuf) {
len = datalen - (th->th_off << 2);
snprintf(logbuf + loglen, sizeof logbuf - loglen,
"TCP: %s:%d ---> ", ncpaddr_ntoa(&srcaddr), ntohs(th->th_sport));
loglen += strlen(logbuf + loglen);
snprintf(logbuf + loglen, sizeof logbuf - loglen,
"%s:%d", ncpaddr_ntoa(&dstaddr), ntohs(th->th_dport));
loglen += strlen(logbuf + loglen);
n = 0;
for (mask = TH_FIN; mask != 0x40; mask <<= 1) {
if (th->th_flags & mask) {
snprintf(logbuf + loglen, sizeof logbuf - loglen, " %s", TcpFlags[n]);
loglen += strlen(logbuf + loglen);
}
n++;
}
snprintf(logbuf + loglen, sizeof logbuf - loglen,
" seq:%lx ack:%lx (%d/%d)",
(u_long)ntohl(th->th_seq), (u_long)ntohl(th->th_ack), len, nb);
loglen += strlen(logbuf + loglen);
if ((th->th_flags & TH_SYN) && nb > 40) {
const u_short *sp;
sp = (const u_short *)(payload + 20);
if (ntohs(sp[0]) == 0x0204) {
snprintf(logbuf + loglen, sizeof logbuf - loglen,
" MSS = %d", ntohs(sp[1]));
loglen += strlen(logbuf + loglen);
}
}
}
break;
default:
if (prefix)
return -2;
if (logit && loglen < sizeof logbuf) {
snprintf(logbuf + loglen, sizeof logbuf - loglen,
"<%d>: %s ---> ", cproto, ncpaddr_ntoa(&srcaddr));
loglen += strlen(logbuf + loglen);
snprintf(logbuf + loglen, sizeof logbuf - loglen,
"%s (%d)", ncpaddr_ntoa(&dstaddr), nb);
loglen += strlen(logbuf + loglen);
}
break;
}
if (filter && FilterCheck(packet, family, filter, psecs)) {
if (logit)
log_Printf(LogTCPIP, "%s - BLOCKED\n", logbuf);
result = -1;
} else {
/* Check Keep Alive filter */
if (logit && log_IsKept(LogTCPIP)) {
unsigned alivesecs;
alivesecs = 0;
if (filter &&
FilterCheck(packet, family, &bundle->filter.alive, &alivesecs))
log_Printf(LogTCPIP, "%s - NO KEEPALIVE\n", logbuf);
else if (psecs != NULL) {
if(*psecs == 0)
*psecs = alivesecs;
if (*psecs) {
if (*psecs != alivesecs)
log_Printf(LogTCPIP, "%s - (timeout = %d / ALIVE = %d secs)\n",
logbuf, *psecs, alivesecs);
else
log_Printf(LogTCPIP, "%s - (timeout = %d secs)\n", logbuf, *psecs);
} else
log_Printf(LogTCPIP, "%s\n", logbuf);
}
}
result = pri;
}
if (filter && uh && ntohs(uh->uh_dport) == 53 && log_IsKept(LogDNS))
ip_LogDNS(uh, filter->name);
return result;
}
static int
ip_Input(struct bundle *bundle, struct link *l, struct mbuf *bp, u_int32_t af)
{
int nb, nw;
struct tun_data tun;
char *data;
unsigned secs, alivesecs;
nb = m_length(bp);
if (nb > sizeof tun.data) {
log_Printf(LogWARN, "ip_Input: %s: Packet too large (got %d, max %d)\n",
l->name, nb, (int)(sizeof tun.data));
m_freem(bp);
return 0;
}
mbuf_Read(bp, tun.data, nb);
secs = 0;
if (PacketCheck(bundle, af, tun.data, nb, &bundle->filter.in,
NULL, &secs) < 0)
return 0;
alivesecs = 0;
if (!FilterCheck(tun.data, af, &bundle->filter.alive, &alivesecs)) {
if (secs == 0)
secs = alivesecs;
bundle_StartIdleTimer(bundle, secs);
}
if (bundle->dev.header) {
tun.header.family = htonl(af);
nb += sizeof tun - sizeof tun.data;
data = (char *)&tun;
} else
data = tun.data;
nw = write(bundle->dev.fd, data, nb);
if (nw != nb) {
if (nw == -1)
log_Printf(LogERROR, "ip_Input: %s: wrote %d, got %s\n",
l->name, nb, strerror(errno));
else
log_Printf(LogERROR, "ip_Input: %s: wrote %d, got %d\n", l->name, nb, nw);
}
return nb;
}
struct mbuf *
ipv4_Input(struct bundle *bundle, struct link *l, struct mbuf *bp)
{
int nb;
if (bundle->ncp.ipcp.fsm.state != ST_OPENED) {
log_Printf(LogWARN, "ipv4_Input: IPCP not open - packet dropped\n");
m_freem(bp);
return NULL;
}
m_settype(bp, MB_IPIN);
nb = ip_Input(bundle, l, bp, AF_INET);
ipcp_AddInOctets(&bundle->ncp.ipcp, nb);
return NULL;
}
#ifndef NOINET6
struct mbuf *
ipv6_Input(struct bundle *bundle, struct link *l, struct mbuf *bp)
{
int nb;
if (bundle->ncp.ipv6cp.fsm.state != ST_OPENED) {
log_Printf(LogWARN, "ipv6_Input: IPV6CP not open - packet dropped\n");
m_freem(bp);
return NULL;
}
m_settype(bp, MB_IPV6IN);
nb = ip_Input(bundle, l, bp, AF_INET6);
ipv6cp_AddInOctets(&bundle->ncp.ipv6cp, nb);
return NULL;
}
#endif