3006ec67fe
This is a type of physical link that can chat and talk LCP & CCP. A bundle contains a list of these (only one in the list for the moment). The datalink is a type of descriptor, and dials, enters LCP (& does CCP), kicks the bundle when its FSMs do something interesting and does the hangup chat script on the way down. It also handles redials and reconnects. There are lots of loose ends, and probably lots of bugs, but the data structures are getting there !
539 lines
14 KiB
C
539 lines
14 KiB
C
/*
|
|
* PPP IP Protocol Interface
|
|
*
|
|
* Written by Toshiharu OHNO (tony-o@iij.ad.jp)
|
|
*
|
|
* Copyright (C) 1993, Internet Initiative Japan, Inc. All rights reserverd.
|
|
*
|
|
* Redistribution and use in source and binary forms are permitted
|
|
* provided that the above copyright notice and this paragraph are
|
|
* duplicated in all such forms and that any documentation,
|
|
* advertising materials, and other materials related to such
|
|
* distribution and use acknowledge that the software was developed
|
|
* by the Internet Initiative Japan. The name of the
|
|
* IIJ may not be used to endorse or promote products derived
|
|
* from this software without specific prior written permission.
|
|
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
|
|
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
|
|
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
|
|
*
|
|
* $Id: ip.c,v 1.38.2.6 1998/02/07 20:49:38 brian Exp $
|
|
*
|
|
* TODO:
|
|
* o Return ICMP message for filterd packet
|
|
* and optionaly record it into log.
|
|
*/
|
|
#include <sys/param.h>
|
|
#include <sys/time.h>
|
|
#include <sys/socket.h>
|
|
#include <net/if.h>
|
|
#include <net/if_tun.h>
|
|
#include <netinet/in.h>
|
|
#include <netinet/in_systm.h>
|
|
#include <netinet/ip.h>
|
|
#include <netinet/ip_icmp.h>
|
|
#include <netinet/udp.h>
|
|
#include <netinet/tcp.h>
|
|
#include <arpa/inet.h>
|
|
|
|
#ifndef NOALIAS
|
|
#include <alias.h>
|
|
#endif
|
|
#include <errno.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <termios.h>
|
|
#include <unistd.h>
|
|
|
|
#include "command.h"
|
|
#include "mbuf.h"
|
|
#include "log.h"
|
|
#include "defs.h"
|
|
#include "timer.h"
|
|
#include "fsm.h"
|
|
#include "hdlc.h"
|
|
#include "loadalias.h"
|
|
#include "vars.h"
|
|
#include "filter.h"
|
|
#include "bundle.h"
|
|
#include "iplist.h"
|
|
#include "throughput.h"
|
|
#include "ipcp.h"
|
|
#include "vjcomp.h"
|
|
#include "lcp.h"
|
|
#include "modem.h"
|
|
#include "tun.h"
|
|
#include "ip.h"
|
|
|
|
static struct pppTimer IdleTimer;
|
|
|
|
static void
|
|
IdleTimeout(void *v)
|
|
{
|
|
LogPrintf(LogPHASE, "Idle timer expired.\n");
|
|
bundle_Close(LcpInfo.fsm.bundle, NULL, 1);
|
|
}
|
|
|
|
/*
|
|
* Start Idle timer. If timeout is reached, we call bundle_Close() to
|
|
* close LCP and link.
|
|
*/
|
|
void
|
|
StartIdleTimer()
|
|
{
|
|
static time_t IdleStarted;
|
|
|
|
if (!(mode & (MODE_DEDICATED | MODE_DDIAL))) {
|
|
StopTimer(&IdleTimer);
|
|
IdleTimer.func = IdleTimeout;
|
|
IdleTimer.load = VarIdleTimeout * SECTICKS;
|
|
IdleTimer.state = TIMER_STOPPED;
|
|
time(&IdleStarted);
|
|
IdleTimer.arg = (void *)&IdleStarted;
|
|
StartTimer(&IdleTimer);
|
|
}
|
|
}
|
|
|
|
void
|
|
UpdateIdleTimer(const struct bundle *bundle)
|
|
{
|
|
if (bundle_LinkIsUp(bundle))
|
|
StartIdleTimer();
|
|
}
|
|
|
|
void
|
|
StopIdleTimer()
|
|
{
|
|
StopTimer(&IdleTimer);
|
|
}
|
|
|
|
int
|
|
RemainingIdleTime()
|
|
{
|
|
if (VarIdleTimeout == 0 || IdleTimer.state != TIMER_RUNNING ||
|
|
IdleTimer.arg == NULL)
|
|
return -1;
|
|
return VarIdleTimeout - (time(NULL) - *(time_t *)IdleTimer.arg);
|
|
}
|
|
|
|
/*
|
|
* If any IP layer traffic is detected, refresh IdleTimer.
|
|
*/
|
|
static void
|
|
RestartIdleTimer(void)
|
|
{
|
|
if (!(mode & (MODE_DEDICATED | MODE_DDIAL)) && ipKeepAlive) {
|
|
time((time_t *)IdleTimer.arg);
|
|
StartTimer(&IdleTimer);
|
|
}
|
|
}
|
|
|
|
static const u_short interactive_ports[32] = {
|
|
544, 513, 514, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
|
|
0, 0, 0, 0, 0, 21, 22, 23, 0, 0, 0, 0, 0, 0, 0, 543,
|
|
};
|
|
|
|
#define INTERACTIVE(p) (interactive_ports[(p) & 0x1F] == (p))
|
|
|
|
static const char *TcpFlags[] = { "FIN", "SYN", "RST", "PSH", "ACK", "URG" };
|
|
|
|
static const char *Direction[] = {"INP", "OUT", "OUT", "IN/OUT"};
|
|
static struct filterent *Filters[] = {ifilters, ofilters, dfilters, afilters};
|
|
|
|
static 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);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Check a packet against with defined filters
|
|
*/
|
|
static int
|
|
FilterCheck(struct ip * pip, int direction)
|
|
{
|
|
struct filterent *fp = Filters[direction];
|
|
int gotinfo, cproto, estab, n;
|
|
struct tcphdr *th;
|
|
struct udphdr *uh;
|
|
struct icmp *ih;
|
|
char *ptop;
|
|
u_short sport, dport;
|
|
|
|
if (fp->action) {
|
|
cproto = gotinfo = estab = 0;
|
|
sport = dport = 0;
|
|
for (n = 0; n < MAXFILTERS; n++) {
|
|
if (fp->action) {
|
|
/* permit fragments on in and out filter */
|
|
if ((direction == FL_IN || direction == FL_OUT) &&
|
|
(ntohs(pip->ip_off) & IP_OFFMASK) != 0) {
|
|
return (A_PERMIT);
|
|
}
|
|
LogPrintf(LogDEBUG, "rule = %d\n", n);
|
|
if ((pip->ip_src.s_addr & fp->smask.s_addr) ==
|
|
(fp->saddr.s_addr & fp->smask.s_addr) &&
|
|
(pip->ip_dst.s_addr & fp->dmask.s_addr) ==
|
|
(fp->daddr.s_addr & fp->dmask.s_addr)) {
|
|
if (fp->proto) {
|
|
if (!gotinfo) {
|
|
ptop = (char *) pip + (pip->ip_hl << 2);
|
|
|
|
switch (pip->ip_p) {
|
|
case IPPROTO_ICMP:
|
|
cproto = P_ICMP;
|
|
ih = (struct icmp *) ptop;
|
|
sport = ih->icmp_type;
|
|
estab = 1;
|
|
break;
|
|
case IPPROTO_UDP:
|
|
cproto = P_UDP;
|
|
uh = (struct udphdr *) ptop;
|
|
sport = ntohs(uh->uh_sport);
|
|
dport = ntohs(uh->uh_dport);
|
|
estab = 1;
|
|
break;
|
|
case IPPROTO_TCP:
|
|
cproto = P_TCP;
|
|
th = (struct tcphdr *) ptop;
|
|
sport = ntohs(th->th_sport);
|
|
dport = ntohs(th->th_dport);
|
|
estab = (th->th_flags & TH_ACK);
|
|
if (estab == 0)
|
|
LogPrintf(LogDEBUG, "flag = %02x, sport = %d, dport = %d\n",
|
|
th->th_flags, sport, dport);
|
|
break;
|
|
default:
|
|
return (A_DENY);/* We'll block unknown type of packet */
|
|
}
|
|
gotinfo = 1;
|
|
LogPrintf(LogDEBUG, "dir = %d, proto = %d, srcop = %d,"
|
|
" dstop = %d, estab = %d\n", direction, cproto,
|
|
fp->opt.srcop, fp->opt.dstop, estab);
|
|
}
|
|
LogPrintf(LogDEBUG, "check0: rule = %d, proto = %d, sport = %d,"
|
|
" dport = %d\n", n, cproto, sport, dport);
|
|
LogPrintf(LogDEBUG, "check0: action = %d\n", fp->action);
|
|
|
|
if (cproto == fp->proto) {
|
|
if ((fp->opt.srcop == OP_NONE ||
|
|
PortMatch(fp->opt.srcop, sport, fp->opt.srcport))
|
|
&&
|
|
(fp->opt.dstop == OP_NONE ||
|
|
PortMatch(fp->opt.dstop, dport, fp->opt.dstport))
|
|
&&
|
|
(fp->opt.estab == 0 || estab)) {
|
|
return (fp->action);
|
|
}
|
|
}
|
|
} else {
|
|
/* Address is mached. Make a decision. */
|
|
LogPrintf(LogDEBUG, "check1: action = %d\n", fp->action);
|
|
return (fp->action);
|
|
}
|
|
}
|
|
}
|
|
fp++;
|
|
}
|
|
return (A_DENY); /* No rule is mached. Deny this packet */
|
|
}
|
|
return (A_PERMIT); /* No rule is given. Permit this packet */
|
|
}
|
|
|
|
static void
|
|
IcmpError(struct ip * pip, int code)
|
|
{
|
|
#ifdef notdef
|
|
struct mbuf *bp;
|
|
|
|
if (pip->ip_p != IPPROTO_ICMP) {
|
|
bp = mballoc(cnt, MB_IPIN);
|
|
memcpy(MBUF_CTOP(bp), ptr, cnt);
|
|
SendPppFrame(bp);
|
|
RestartIdleTimer();
|
|
IpcpAddOutOctets(cnt);
|
|
}
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* For debugging aid.
|
|
*/
|
|
int
|
|
PacketCheck(char *cp, int nb, int direction)
|
|
{
|
|
struct ip *pip;
|
|
struct tcphdr *th;
|
|
struct udphdr *uh;
|
|
struct icmp *icmph;
|
|
char *ptop;
|
|
int mask, len, n;
|
|
int pri = PRI_NORMAL;
|
|
int logit, loglen;
|
|
static char logbuf[200];
|
|
|
|
logit = LogIsKept(LogTCPIP) && direction != FL_DIAL;
|
|
loglen = 0;
|
|
|
|
pip = (struct ip *) cp;
|
|
|
|
if (logit && loglen < sizeof logbuf) {
|
|
snprintf(logbuf + loglen, sizeof logbuf - loglen, "%s ",
|
|
Direction[direction]);
|
|
loglen += strlen(logbuf + loglen);
|
|
}
|
|
ptop = (cp + (pip->ip_hl << 2));
|
|
|
|
switch (pip->ip_p) {
|
|
case IPPROTO_ICMP:
|
|
if (logit && loglen < sizeof logbuf) {
|
|
icmph = (struct icmp *) ptop;
|
|
snprintf(logbuf + loglen, sizeof logbuf - loglen,
|
|
"ICMP: %s:%d ---> ", inet_ntoa(pip->ip_src), icmph->icmp_type);
|
|
loglen += strlen(logbuf + loglen);
|
|
snprintf(logbuf + loglen, sizeof logbuf - loglen,
|
|
"%s:%d", inet_ntoa(pip->ip_dst), icmph->icmp_type);
|
|
loglen += strlen(logbuf + loglen);
|
|
}
|
|
break;
|
|
case IPPROTO_UDP:
|
|
if (logit && loglen < sizeof logbuf) {
|
|
uh = (struct udphdr *) ptop;
|
|
snprintf(logbuf + loglen, sizeof logbuf - loglen,
|
|
"UDP: %s:%d ---> ", inet_ntoa(pip->ip_src), ntohs(uh->uh_sport));
|
|
loglen += strlen(logbuf + loglen);
|
|
snprintf(logbuf + loglen, sizeof logbuf - loglen,
|
|
"%s:%d", inet_ntoa(pip->ip_dst), ntohs(uh->uh_dport));
|
|
loglen += strlen(logbuf + loglen);
|
|
}
|
|
break;
|
|
case IPPROTO_TCP:
|
|
th = (struct tcphdr *) ptop;
|
|
if (pip->ip_tos == IPTOS_LOWDELAY)
|
|
pri = PRI_FAST;
|
|
else if ((ntohs(pip->ip_off) & IP_OFFMASK) == 0) {
|
|
if (INTERACTIVE(ntohs(th->th_sport)) || INTERACTIVE(ntohs(th->th_dport)))
|
|
pri = PRI_FAST;
|
|
}
|
|
if (logit && loglen < sizeof logbuf) {
|
|
len = ntohs(pip->ip_len) - (pip->ip_hl << 2) - (th->th_off << 2);
|
|
snprintf(logbuf + loglen, sizeof logbuf - loglen,
|
|
"TCP: %s:%d ---> ", inet_ntoa(pip->ip_src), ntohs(th->th_sport));
|
|
loglen += strlen(logbuf + loglen);
|
|
snprintf(logbuf + loglen, sizeof logbuf - loglen,
|
|
"%s:%d", inet_ntoa(pip->ip_dst), 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:%x ack:%x (%d/%d)",
|
|
ntohl(th->th_seq), ntohl(th->th_ack), len, nb);
|
|
loglen += strlen(logbuf + loglen);
|
|
if ((th->th_flags & TH_SYN) && nb > 40) {
|
|
u_short *sp;
|
|
|
|
ptop += 20;
|
|
sp = (u_short *) ptop;
|
|
if (ntohs(sp[0]) == 0x0204) {
|
|
snprintf(logbuf + loglen, sizeof logbuf - loglen,
|
|
" MSS = %d", ntohs(sp[1]));
|
|
loglen += strlen(logbuf + loglen);
|
|
}
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
|
|
if ((FilterCheck(pip, direction) & A_DENY)) {
|
|
if (logit)
|
|
LogPrintf(LogTCPIP, "%s - BLOCKED\n", logbuf);
|
|
if (direction == 0)
|
|
IcmpError(pip, pri);
|
|
return (-1);
|
|
} else {
|
|
if (FilterCheck(pip, FL_KEEP) & A_DENY) { /* Check Keep Alive filter */
|
|
if (logit)
|
|
LogPrintf(LogTCPIP, "%s - NO KEEPALIVE\n", logbuf);
|
|
ipKeepAlive = 0;
|
|
} else {
|
|
if (logit)
|
|
LogPrintf(LogTCPIP, "%s\n", logbuf);
|
|
ipKeepAlive = 1;
|
|
}
|
|
return (pri);
|
|
}
|
|
}
|
|
|
|
void
|
|
IpInput(struct bundle *bundle, struct mbuf * bp)
|
|
{
|
|
u_char *cp;
|
|
struct mbuf *wp;
|
|
int nb, nw;
|
|
struct tun_data tun;
|
|
|
|
tun_fill_header(tun, AF_INET);
|
|
cp = tun.data;
|
|
nb = 0;
|
|
for (wp = bp; wp; wp = wp->next) { /* Copy to contiguous region */
|
|
if (sizeof tun.data - (cp - tun.data) < wp->cnt) {
|
|
LogPrintf(LogERROR, "IpInput: Packet too large (%d) - dropped\n",
|
|
plength(bp));
|
|
pfree(bp);
|
|
return;
|
|
}
|
|
memcpy(cp, MBUF_CTOP(wp), wp->cnt);
|
|
cp += wp->cnt;
|
|
nb += wp->cnt;
|
|
}
|
|
|
|
#ifndef NOALIAS
|
|
if (mode & MODE_ALIAS) {
|
|
struct tun_data *frag;
|
|
int iresult;
|
|
char *fptr;
|
|
|
|
iresult = VarPacketAliasIn(tun.data, sizeof tun.data);
|
|
nb = ntohs(((struct ip *) tun.data)->ip_len);
|
|
|
|
if (nb > MAX_MRU) {
|
|
LogPrintf(LogERROR, "IpInput: Problem with IP header length\n");
|
|
pfree(bp);
|
|
return;
|
|
}
|
|
if (iresult == PKT_ALIAS_OK
|
|
|| iresult == PKT_ALIAS_FOUND_HEADER_FRAGMENT) {
|
|
if (PacketCheck(tun.data, nb, FL_IN) < 0) {
|
|
pfree(bp);
|
|
return;
|
|
}
|
|
IpcpAddInOctets(nb);
|
|
|
|
nb = ntohs(((struct ip *) tun.data)->ip_len);
|
|
nb += sizeof tun - sizeof tun.data;
|
|
nw = write(bundle->tun_fd, &tun, nb);
|
|
if (nw != nb)
|
|
if (nw == -1)
|
|
LogPrintf(LogERROR, "IpInput: wrote %d, got %s\n", nb,
|
|
strerror(errno));
|
|
else
|
|
LogPrintf(LogERROR, "IpInput: wrote %d, got %d\n", nb, nw);
|
|
|
|
if (iresult == PKT_ALIAS_FOUND_HEADER_FRAGMENT) {
|
|
while ((fptr = VarPacketAliasGetFragment(tun.data)) != NULL) {
|
|
VarPacketAliasFragmentIn(tun.data, fptr);
|
|
nb = ntohs(((struct ip *) fptr)->ip_len);
|
|
frag = (struct tun_data *)
|
|
((char *)fptr - sizeof tun + sizeof tun.data);
|
|
nb += sizeof tun - sizeof tun.data;
|
|
nw = write(bundle->tun_fd, frag, nb);
|
|
if (nw != nb)
|
|
if (nw == -1)
|
|
LogPrintf(LogERROR, "IpInput: wrote %d, got %s\n", nb,
|
|
strerror(errno));
|
|
else
|
|
LogPrintf(LogERROR, "IpInput: wrote %d, got %d\n", nb, nw);
|
|
free(frag);
|
|
}
|
|
}
|
|
} else if (iresult == PKT_ALIAS_UNRESOLVED_FRAGMENT) {
|
|
nb = ntohs(((struct ip *) tun.data)->ip_len);
|
|
nb += sizeof tun - sizeof tun.data;
|
|
frag = (struct tun_data *)malloc(nb);
|
|
if (frag == NULL)
|
|
LogPrintf(LogALERT, "IpInput: Cannot allocate memory for fragment\n");
|
|
else {
|
|
tun_fill_header(*frag, AF_INET);
|
|
memcpy(frag->data, tun.data, nb - sizeof tun + sizeof tun.data);
|
|
VarPacketAliasSaveFragment(frag->data);
|
|
}
|
|
}
|
|
} else
|
|
#endif /* #ifndef NOALIAS */
|
|
{ /* no aliasing */
|
|
if (PacketCheck(tun.data, nb, FL_IN) < 0) {
|
|
pfree(bp);
|
|
return;
|
|
}
|
|
IpcpAddInOctets(nb);
|
|
nb += sizeof tun - sizeof tun.data;
|
|
nw = write(bundle->tun_fd, &tun, nb);
|
|
if (nw != nb)
|
|
if (nw == -1)
|
|
LogPrintf(LogERROR, "IpInput: wrote %d, got %s\n", nb, strerror(errno));
|
|
else
|
|
LogPrintf(LogERROR, "IpInput: wrote %d, got %d\n", nb, nw);
|
|
}
|
|
pfree(bp);
|
|
|
|
RestartIdleTimer();
|
|
}
|
|
|
|
static struct mqueue IpOutputQueues[PRI_FAST + 1];
|
|
|
|
void
|
|
IpEnqueue(int pri, char *ptr, int count)
|
|
{
|
|
struct mbuf *bp;
|
|
|
|
bp = mballoc(count, MB_IPQ);
|
|
memcpy(MBUF_CTOP(bp), ptr, count);
|
|
Enqueue(&IpOutputQueues[pri], bp);
|
|
}
|
|
|
|
#if 0
|
|
int
|
|
IsIpEnqueued()
|
|
{
|
|
struct mqueue *queue;
|
|
int exist = 0;
|
|
|
|
for (queue = &IpOutputQueues[PRI_FAST]; queue >= IpOutputQueues; queue--) {
|
|
if (queue->qlen > 0) {
|
|
exist = 1;
|
|
break;
|
|
}
|
|
}
|
|
return (exist);
|
|
}
|
|
#endif
|
|
|
|
void
|
|
IpStartOutput(struct link *l)
|
|
{
|
|
struct mqueue *queue;
|
|
struct mbuf *bp;
|
|
int cnt;
|
|
|
|
if (IpcpInfo.fsm.state != ST_OPENED)
|
|
return;
|
|
for (queue = &IpOutputQueues[PRI_FAST]; queue >= IpOutputQueues; queue--) {
|
|
if (queue->top) {
|
|
bp = Dequeue(queue);
|
|
if (bp) {
|
|
cnt = plength(bp);
|
|
SendPppFrame(l, bp);
|
|
RestartIdleTimer();
|
|
IpcpAddOutOctets(cnt);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|