ip.c revision 6059
16059Samurai/* 26059Samurai * PPP IP Protocol Interface 36059Samurai * 46059Samurai * Written by Toshiharu OHNO (tony-o@iij.ad.jp) 56059Samurai * 66059Samurai * Copyright (C) 1993, Internet Initiative Japan, Inc. All rights reserverd. 76059Samurai * 86059Samurai * Redistribution and use in source and binary forms are permitted 96059Samurai * provided that the above copyright notice and this paragraph are 106059Samurai * duplicated in all such forms and that any documentation, 116059Samurai * advertising materials, and other materials related to such 126059Samurai * distribution and use acknowledge that the software was developed 136059Samurai * by the Internet Initiative Japan. The name of the 146059Samurai * IIJ may not be used to endorse or promote products derived 156059Samurai * from this software without specific prior written permission. 166059Samurai * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 176059Samurai * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 186059Samurai * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 196059Samurai * 206059Samurai * $Id:$ 216059Samurai * 226059Samurai * TODO: 236059Samurai * o Return ICMP message for filterd packet 246059Samurai * and optionaly record it into log. 256059Samurai */ 266059Samurai#include "fsm.h" 276059Samurai#include "lcpproto.h" 286059Samurai#include "hdlc.h" 296059Samurai#include <netinet/in_systm.h> 306059Samurai#include <netinet/ip.h> 316059Samurai#include <netinet/ip_icmp.h> 326059Samurai#include <netinet/udp.h> 336059Samurai#include <netinet/tcp.h> 346059Samurai#include "vars.h" 356059Samurai#include "filter.h" 366059Samurai 376059Samuraiextern void SendPppFlame(); 386059Samuraiextern int PacketCheck(); 396059Samuraiextern void LcpClose(); 406059Samurai 416059Samuraistatic struct pppTimer IdleTimer; 426059Samurai 436059Samuraistatic void IdleTimeout() 446059Samurai{ 456059Samurai LogPrintf(LOG_PHASE, "Idle timer expired.\n"); 466059Samurai LcpClose(); 476059Samurai} 486059Samurai 496059Samurai/* 506059Samurai * Start Idle timer. If timeout is reached, we call LcpClose() to 516059Samurai * close LCP and link. 526059Samurai */ 536059Samuraivoid 546059SamuraiStartIdleTimer() 556059Samurai{ 566059Samurai if (!(mode & MODE_DEDICATED)) { 576059Samurai StopTimer(&IdleTimer); 586059Samurai IdleTimer.func = IdleTimeout; 596059Samurai IdleTimer.load = VarIdleTimeout * SECTICKS; 606059Samurai IdleTimer.state = TIMER_STOPPED; 616059Samurai StartTimer(&IdleTimer); 626059Samurai } 636059Samurai} 646059Samurai 656059Samuraivoid 666059SamuraiStopIdleTimer() 676059Samurai{ 686059Samurai StopTimer(&IdleTimer); 696059Samurai} 706059Samurai 716059Samurai/* 726059Samurai * If any IP layer traffic is detected, refresh IdleTimer. 736059Samurai */ 746059Samuraistatic void 756059SamuraiRestartIdleTimer() 766059Samurai{ 776059Samurai if (!(mode & MODE_DEDICATED)) { 786059Samurai StopTimer(&IdleTimer); 796059Samurai StartTimer(&IdleTimer); 806059Samurai ipIdleSecs = 0; 816059Samurai } 826059Samurai} 836059Samurai 846059Samuraistatic u_short interactive_ports[8] = { 856059Samurai 0, 513, 0, 0, 0, 21, 0, 23, 866059Samurai}; 876059Samurai 886059Samurai#define INTERACTIVE(p) (interactive_ports[(p) & 7] == (p)) 896059Samurai 906059Samuraistatic char *TcpFlags[] = { 916059Samurai "FIN", "SYN", "RST", "PSH", "ACK", "URG", 926059Samurai}; 936059Samurai 946059Samuraistatic char *Direction[] = { "INP", "OUT", "OUT" }; 956059Samuraistatic struct filterent *Filters[] = { ifilters, ofilters, dfilters }; 966059Samurai 976059Samuraistatic int 986059SamuraiPortMatch(op, pport, rport) 996059Samuraiint op; 1006059Samuraiu_short pport, rport; 1016059Samurai{ 1026059Samurai switch (op) { 1036059Samurai case OP_EQ: 1046059Samurai return(pport == rport); 1056059Samurai case OP_GT: 1066059Samurai return(pport > rport); 1076059Samurai case OP_LT: 1086059Samurai return(pport < rport); 1096059Samurai default: 1106059Samurai return(0); 1116059Samurai } 1126059Samurai} 1136059Samurai 1146059Samurai/* 1156059Samurai * Check a packet against with defined filters 1166059Samurai */ 1176059Samuraistatic int 1186059SamuraiFilterCheck(pip, direction) 1196059Samuraistruct ip *pip; 1206059Samuraiint direction; 1216059Samurai{ 1226059Samurai struct filterent *fp = Filters[direction]; 1236059Samurai int gotinfo, cproto, estab, n; 1246059Samurai struct tcphdr *th; 1256059Samurai struct udphdr *uh; 1266059Samurai struct icmp *ih; 1276059Samurai char *ptop; 1286059Samurai u_short sport, dport; 1296059Samurai 1306059Samurai if (fp->action) { 1316059Samurai cproto = gotinfo = estab = 0; 1326059Samurai sport = dport = 0; 1336059Samurai for (n = 0; n < MAXFILTERS; n++) { 1346059Samurai if (fp->action) { 1356059Samurai#ifdef DEBUG 1366059Samurailogprintf("rule = %d\n", n); 1376059Samurai#endif 1386059Samurai if ((pip->ip_src.s_addr & fp->smask.s_addr) == fp->saddr.s_addr 1396059Samurai && (pip->ip_dst.s_addr & fp->dmask.s_addr) == fp->daddr.s_addr) { 1406059Samurai if (fp->proto) { 1416059Samurai if (!gotinfo) { 1426059Samurai ptop = (char *)pip + (pip->ip_hl << 2); 1436059Samurai 1446059Samurai switch (pip->ip_p) { 1456059Samurai case IPPROTO_ICMP: 1466059Samurai cproto = P_ICMP; ih = (struct icmp *)ptop; 1476059Samurai sport = ih->icmp_type; estab = 1; 1486059Samurai break; 1496059Samurai case IPPROTO_UDP: 1506059Samurai cproto = P_UDP; uh = (struct udphdr *)ptop; 1516059Samurai sport = ntohs(uh->uh_sport); dport = ntohs(uh->uh_dport); 1526059Samurai estab = 1; 1536059Samurai break; 1546059Samurai case IPPROTO_TCP: 1556059Samurai cproto = P_TCP; th = (struct tcphdr *)ptop; 1566059Samurai sport = ntohs(th->th_sport); dport = ntohs(th->th_dport); 1576059Samurai estab = (th->th_flags & TH_ACK); 1586059Samurai break; 1596059Samurai default: 1606059Samurai return(A_DENY); /* We'll block unknown type of packet */ 1616059Samurai } 1626059Samurai gotinfo = 1; 1636059Samurai#ifdef DEBUG 1646059Samurailogprintf("dir = %d, proto = %d, srcop = %d, dstop = %d, estab = %d\n", 1656059Samuraidirection, cproto, fp->opt.srcop, fp->opt.dstop, estab); 1666059Samuraiif (estab == 0) 1676059Samurailogprintf("flag = %02x, sport = %d, dport = %d\n", th->th_flags, sport, dport); 1686059Samurai#endif 1696059Samurai } 1706059Samurai#ifdef DEBUG 1716059Samurai logprintf("check0: rule = %d, proto = %d, sport = %d, dport = %d\n", 1726059Samurai n, cproto, sport, dport); 1736059Samurai logprintf("check0: action = %d\n", fp->action); 1746059Samurai#endif 1756059Samurai if (cproto == fp->proto) { 1766059Samurai if ((fp->opt.srcop == OP_NONE || 1776059Samurai PortMatch(fp->opt.srcop, sport, fp->opt.srcport)) 1786059Samurai && 1796059Samurai (fp->opt.dstop == OP_NONE || 1806059Samurai PortMatch(fp->opt.dstop, dport, fp->opt.dstport)) 1816059Samurai && 1826059Samurai (fp->opt.estab == 0 || estab)) { 1836059Samurai return(fp->action); 1846059Samurai } 1856059Samurai } 1866059Samurai } else { 1876059Samurai /* Address is mached. Make a decision. */ 1886059Samurai#ifdef DEBUG 1896059Samurai logprintf("check1: action = %d\n", fp->action); 1906059Samurai#endif 1916059Samurai return(fp->action); 1926059Samurai } 1936059Samurai } 1946059Samurai } 1956059Samurai fp++; 1966059Samurai } 1976059Samuraidrop: 1986059Samurai return(A_DENY); /* No rule is mached. Deny this packet */ 1996059Samurai } 2006059Samurai return(A_PERMIT); /* No rule is given. Permit this packet */ 2016059Samurai} 2026059Samurai 2036059Samuraistatic void 2046059SamuraiIcmpError(pip, code) 2056059Samuraistruct ip *pip; 2066059Samuraiint code; 2076059Samurai{ 2086059Samurai#ifdef notdef 2096059Samurai struct mbuf *bp; 2106059Samurai 2116059Samurai if (pip->ip_p != IPPROTO_ICMP) { 2126059Samurai bp = mballoc(cnt, MB_IPIN); 2136059Samurai bcopy(ptr, MBUF_CTOP(bp), cnt); 2146059Samurai SendPppFlame(PRI_URGENT, bp); 2156059Samurai RestartIdleTimer(); 2166059Samurai ipOutOctets += cnt; 2176059Samurai } 2186059Samurai#endif 2196059Samurai} 2206059Samurai 2216059Samurai/* 2226059Samurai * For debugging aid. 2236059Samurai */ 2246059Samuraiint 2256059SamuraiPacketCheck(cp, nb, direction) 2266059Samuraichar *cp; 2276059Samuraiint nb; 2286059Samuraiint direction; 2296059Samurai{ 2306059Samurai struct ip *pip; 2316059Samurai struct tcphdr *th; 2326059Samurai struct udphdr *uh; 2336059Samurai struct icmp *icmph; 2346059Samurai char *ptop; 2356059Samurai int mask, len, n; 2366059Samurai int logit; 2376059Samurai int pri = PRI_NORMAL; 2386059Samurai 2396059Samurai logit = (loglevel & (1 << LOG_TCPIP)); 2406059Samurai 2416059Samurai pip = (struct ip *)cp; 2426059Samurai 2436059Samurai if (logit) logprintf("%s ", Direction[direction]); 2446059Samurai 2456059Samurai ptop = (cp + (pip->ip_hl << 2)); 2466059Samurai 2476059Samurai switch (pip->ip_p) { 2486059Samurai case IPPROTO_ICMP: 2496059Samurai if (logit) { 2506059Samurai icmph = (struct icmp *)ptop; 2516059Samurai logprintf("ICMP: %s:%d ---> ", inet_ntoa(pip->ip_src), icmph->icmp_type); 2526059Samurai logprintf("%s:%d\n", inet_ntoa(pip->ip_dst), icmph->icmp_type); 2536059Samurai } 2546059Samurai break; 2556059Samurai case IPPROTO_UDP: 2566059Samurai if (logit) { 2576059Samurai uh = (struct udphdr *)ptop; 2586059Samurai logprintf("UDP: %s:%d ---> ", inet_ntoa(pip->ip_src), ntohs(uh->uh_sport)); 2596059Samurai logprintf("%s:%d\n", inet_ntoa(pip->ip_dst), ntohs(uh->uh_dport)); 2606059Samurai } 2616059Samurai break; 2626059Samurai case IPPROTO_TCP: 2636059Samurai th = (struct tcphdr *)ptop; 2646059Samurai if (pip->ip_tos == IPTOS_LOWDELAY) 2656059Samurai pri = PRI_FAST; 2666059Samurai else if (pip->ip_off == 0) { 2676059Samurai if (INTERACTIVE(ntohs(th->th_sport)) || INTERACTIVE(ntohs(th->th_dport))) 2686059Samurai pri = PRI_FAST; 2696059Samurai } 2706059Samurai 2716059Samurai if (logit) { 2726059Samurai len = ntohs(pip->ip_len) - (pip->ip_hl << 2) - (th->th_off << 2); 2736059Samurai logprintf("TCP: %s:%d ---> ", inet_ntoa(pip->ip_src), ntohs(th->th_sport)); 2746059Samurai logprintf("%s:%d", inet_ntoa(pip->ip_dst), ntohs(th->th_dport)); 2756059Samurai n = 0; 2766059Samurai for (mask = TH_FIN; mask != 0x40; mask <<= 1) { 2776059Samurai if (th->th_flags & mask) 2786059Samurai logprintf(" %s", TcpFlags[n]); 2796059Samurai n++; 2806059Samurai } 2816059Samurai logprintf(" seq:%x ack:%x (%d/%d)\n", 2826059Samurai ntohl(th->th_seq), ntohl(th->th_ack), len, nb); 2836059Samurai if ((th->th_flags & TH_SYN) && nb > 40) { 2846059Samurai u_short *sp; 2856059Samurai 2866059Samurai ptop += 20; 2876059Samurai sp = (u_short *)ptop; 2886059Samurai if (ntohs(sp[0]) == 0x0204) 2896059Samurai logprintf(" MSS = %d\n", ntohs(sp[1])); 2906059Samurai } 2916059Samurai } 2926059Samurai break; 2936059Samurai } 2946059Samurai pri = FilterCheck(pip, direction); 2956059Samurai if (pri & A_DENY) { 2966059Samurai#ifdef DEBUG 2976059Samurai logprintf("blocked.\n"); 2986059Samurai#endif 2996059Samurai if (direction == 0) IcmpError(pip, pri); 3006059Samurai return(-1); 3016059Samurai } else { 3026059Samurai return(pri); 3036059Samurai } 3046059Samurai} 3056059Samurai 3066059Samuraivoid 3076059SamuraiIpInput(bp) 3086059Samuraistruct mbuf *bp; /* IN: Pointer to IP pakcet */ 3096059Samurai{ 3106059Samurai u_char *cp; 3116059Samurai struct mbuf *wp; 3126059Samurai int nb, nw; 3136059Samurai u_char tunbuff[MAX_MRU]; 3146059Samurai 3156059Samurai cp = tunbuff; 3166059Samurai nb = 0; 3176059Samurai for (wp = bp; wp; wp = wp->next) { /* Copy to continuois region */ 3186059Samurai bcopy(MBUF_CTOP(wp), cp, wp->cnt); 3196059Samurai cp += wp->cnt; 3206059Samurai nb += wp->cnt; 3216059Samurai } 3226059Samurai 3236059Samurai if (PacketCheck(tunbuff, nb, 0) < 0) { 3246059Samurai pfree(bp); 3256059Samurai return; 3266059Samurai } 3276059Samurai 3286059Samurai ipInOctets += nb; 3296059Samurai /* 3306059Samurai * Pass it to tunnel device 3316059Samurai */ 3326059Samurai nw = write(tun_out, tunbuff, nb); 3336059Samurai if (nw != nb) 3346059Samurai fprintf(stderr, "wrote %d, got %d\r\n"); 3356059Samurai pfree(bp); 3366059Samurai 3376059Samurai RestartIdleTimer(); 3386059Samurai} 3396059Samurai 3406059Samuraivoid 3416059SamuraiIpOutput(ptr, cnt) 3426059Samuraiu_char *ptr; /* IN: Pointer to IP packet */ 3436059Samuraiint cnt; /* IN: Length of packet */ 3446059Samurai{ 3456059Samurai struct mbuf *bp; 3466059Samurai int pri; 3476059Samurai 3486059Samurai if (IpcpFsm.state != ST_OPENED) 3496059Samurai return; 3506059Samurai 3516059Samurai pri = PacketCheck(ptr, cnt, 1); 3526059Samurai if (pri >= 0) { 3536059Samurai bp = mballoc(cnt, MB_IPIN); 3546059Samurai bcopy(ptr, MBUF_CTOP(bp), cnt); 3556059Samurai SendPppFlame(pri, bp); 3566059Samurai RestartIdleTimer(); 3576059Samurai ipOutOctets += cnt; 3586059Samurai } 3596059Samurai} 3606059Samurai 3616059Samuraistatic struct mqueue IpOutputQueues[PRI_URGENT+1]; 3626059Samurai 3636059Samuraivoid 3646059SamuraiIpEnqueue(pri, ptr, count) 3656059Samuraiint pri; 3666059Samuraichar *ptr; 3676059Samuraiint count; 3686059Samurai{ 3696059Samurai struct mbuf *bp; 3706059Samurai 3716059Samurai bp = mballoc(count, MB_IPQ); 3726059Samurai bcopy(ptr, MBUF_CTOP(bp), count); 3736059Samurai Enqueue(&IpOutputQueues[pri], bp); 3746059Samurai} 3756059Samurai 3766059Samuraivoid 3776059SamuraiIpStartOutput() 3786059Samurai{ 3796059Samurai struct mqueue *queue; 3806059Samurai struct mbuf *bp; 3816059Samurai int pri, cnt; 3826059Samurai 3836059Samurai if (IpcpFsm.state != ST_OPENED) 3846059Samurai return; 3856059Samurai pri = PRI_URGENT; 3866059Samurai for (queue = &IpOutputQueues[PRI_URGENT]; queue >= IpOutputQueues; queue--) { 3876059Samurai if (queue->top) { 3886059Samurai bp = Dequeue(queue); 3896059Samurai if (bp) { 3906059Samurai cnt = plength(bp); 3916059Samurai SendPppFlame(pri, bp); 3926059Samurai RestartIdleTimer(); 3936059Samurai ipOutOctets += cnt; 3946059Samurai } 3956059Samurai } 3966059Samurai pri--; 3976059Samurai } 3986059Samurai} 399