freebsd-dev/usr.sbin/ppp/ip.c
Brian Somers f4768038f0 o Remove the global CcpInfo. It's now part of the datalink.
Struct bundle will have its own struct ccp in the future
  too.
o The ``set stopped'' command now requires context and doesn't
  work on the IPCP FSM.
o Check if it's time to break out of our top level loop before
  doing a select - otherwise, we'll select forever :-(
o Remove `struct link'::ccp (a temporary hack).  It turns out
  that IpStartOutput() calls link_Output() and link_Output()
  incorrectly calls StartOutput() (really modem_StartOutput)
  requiring the ccp knowledge so that it can call
  IpStartOutput()...  The end result is that the whole IP
  output queue gets dumped into the modem output queue
  and a pile of physical writes are done prematurely.  This
  makes the (original) code in main() actually work in that
  it would not bother selecting() on the tun descriptor when
  our modem queue length was 20 or greater.  Instead, we now
  make that decision based on the overall queue length.

  This will need improvement later.
1998-02-23 00:38:44 +00:00

534 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 1.38.2.7 1998/02/16 00:00:11 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);
}
int
ip_QueueLen()
{
struct mqueue *queue;
int result = 0;
for (queue = &IpOutputQueues[PRI_MAX]; queue >= IpOutputQueues; queue--)
result += queue->qlen;
return result;
}
void
IpStartOutput(struct link *l, struct bundle *bundle)
{
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, bundle);
RestartIdleTimer();
IpcpAddOutOctets(cnt);
break;
}
}
}
}