/* * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that: (1) source code distributions * retain the above copyright notice and this paragraph in its entirety, (2) * distributions including binary code include the above copyright notice and * this paragraph in its entirety in the documentation or other materials * provided with the distribution, and (3) all advertising materials mentioning * features or use of this software display the following acknowledgement: * ``This product includes software developed by the University of California, * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of * the University nor the names of its contributors may 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 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. * * $FreeBSD$ */ #ifndef lint static const char rcsid[] = "@(#) $Header: /tcpdump/master/tcpdump/print-ip.c,v 1.100.4.1 2002/01/25 05:39:54 guy Exp $ (LBL)"; #endif #ifdef HAVE_CONFIG_H #include "config.h" #endif #include #include #include #include #include #include #include #include #include #include "addrtoname.h" #include "interface.h" #include "extract.h" /* must come after interface.h */ #include "ip.h" /* Compatibility */ #ifndef IPPROTO_ND #define IPPROTO_ND 77 #endif /* * print the recorded route in an IP RR, LSRR or SSRR option. */ static void ip_printroute(const char *type, register const u_char *cp, u_int length) { register u_int ptr = cp[2] - 1; register u_int len; printf(" %s{", type); if ((length + 1) & 3) printf(" [bad length %d]", length); if (ptr < 3 || ((ptr + 1) & 3) || ptr > length + 1) printf(" [bad ptr %d]", cp[2]); type = ""; for (len = 3; len < length; len += 4) { if (ptr == len) type = "#"; printf("%s%s", type, ipaddr_string(&cp[len])); type = " "; } printf("%s}", ptr == len? "#" : ""); } static void ip_printts(register const u_char *cp, u_int length) { register u_int ptr = cp[2] - 1; register u_int len = 0; int hoplen; char *type; printf(" TS{"); hoplen = ((cp[3]&0xF) != IPOPT_TS_TSONLY) ? 8 : 4; if ((length - 4) & (hoplen-1)) printf("[bad length %d]", length); if (ptr < 4 || ((ptr - 4) & (hoplen-1)) || ptr > length + 1) printf("[bad ptr %d]", cp[2]); switch (cp[3]&0xF) { case IPOPT_TS_TSONLY: printf("TSONLY"); break; case IPOPT_TS_TSANDADDR: printf("TS+ADDR"); break; /* * prespecified should really be 3, but some ones might send 2 * instead, and the IPOPT_TS_PRESPEC constant can apparently * have both values, so we have to hard-code it here. */ case 2: printf("PRESPEC2.0"); break; case 3: /* IPOPT_TS_PRESPEC */ printf("PRESPEC"); break; default: printf("[bad ts type %d]", cp[3]&0xF); goto done; } type = " "; for (len = 4; len < length; len += hoplen) { if (ptr == len) type = " ^ "; printf("%s%d@%s", type, EXTRACT_32BITS(&cp[len+hoplen-4]), hoplen!=8 ? "" : ipaddr_string(&cp[len])); type = " "; } done: printf("%s", ptr == len ? " ^ " : ""); if (cp[3]>>4) printf(" [%d hops not recorded]} ", cp[3]>>4); else printf("}"); } /* * print IP options. */ static void ip_optprint(register const u_char *cp, u_int length) { register u_int len; for (; length > 0; cp += len, length -= len) { int tt = *cp; if (tt == IPOPT_NOP || tt == IPOPT_EOL) len = 1; else { if (&cp[1] >= snapend) { printf("[|ip]"); return; } len = cp[1]; } if (len <= 0) { printf("[|ip op len %d]", len); return; } if (&cp[1] >= snapend || cp + len > snapend) { printf("[|ip]"); return; } switch (tt) { case IPOPT_EOL: printf(" EOL"); if (length > 1) printf("-%d", length - 1); return; case IPOPT_NOP: printf(" NOP"); break; case IPOPT_TS: ip_printts(cp, len); break; #ifndef IPOPT_SECURITY #define IPOPT_SECURITY 130 #endif /* IPOPT_SECURITY */ case IPOPT_SECURITY: printf(" SECURITY{%d}", len); break; case IPOPT_RR: ip_printroute("RR", cp, len); break; case IPOPT_SSRR: ip_printroute("SSRR", cp, len); break; case IPOPT_LSRR: ip_printroute("LSRR", cp, len); break; #ifndef IPOPT_RA #define IPOPT_RA 148 /* router alert */ #endif case IPOPT_RA: printf(" RA"); if (len != 4) printf("{%d}", len); else if (cp[2] || cp[3]) printf("%d.%d", cp[2], cp[3]); break; default: printf(" IPOPT-%d{%d}", cp[0], len); break; } } } /* * compute an IP header checksum. * don't modifiy the packet. */ u_short in_cksum(const u_short *addr, register u_int len, int csum) { int nleft = len; const u_short *w = addr; u_short answer; int sum = csum; /* * Our algorithm is simple, using a 32 bit accumulator (sum), * we add sequential 16 bit words to it, and at the end, fold * back all the carry bits from the top 16 bits into the lower * 16 bits. */ while (nleft > 1) { sum += *w++; nleft -= 2; } if (nleft == 1) sum += htons(*(u_char *)w<<8); /* * add back carry outs from top 16 bits to low 16 bits */ sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */ sum += (sum >> 16); /* add carry */ answer = ~sum; /* truncate to 16 bits */ return (answer); } /* * print an IP datagram. */ void ip_print(register const u_char *bp, register u_int length) { register const struct ip *ip; register u_int hlen, len, len0, off; register const u_char *cp; u_char nh; int advance; struct protoent *proto; ip = (const struct ip *)bp; #ifdef LBL_ALIGN /* * If the IP header is not aligned, copy into abuf. */ if ((long)ip & 3) { static u_char *abuf = NULL; static int didwarn = 0; if (abuf == NULL) { abuf = (u_char *)malloc(snaplen); if (abuf == NULL) error("ip_print: malloc"); } memcpy((char *)abuf, (char *)ip, min(length, snaplen)); snapend += abuf - (u_char *)ip; packetp = abuf; ip = (struct ip *)abuf; /* We really want libpcap to give us aligned packets */ if (!didwarn) { warning("compensating for unaligned libpcap packets"); ++didwarn; } } #endif if ((u_char *)(ip + 1) > snapend) { printf("[|ip]"); return; } if (length < sizeof (struct ip)) { (void)printf("truncated-ip %d", length); return; } hlen = IP_HL(ip) * 4; if (hlen < sizeof (struct ip)) { (void)printf("bad-hlen %d", hlen); return; } len = ntohs(ip->ip_len); if (length < len) (void)printf("truncated-ip - %d bytes missing! ", len - length); len -= hlen; len0 = len; /* * If this is fragment zero, hand it to the next higher * level protocol. */ off = ntohs(ip->ip_off); if ((off & 0x1fff) == 0) { cp = (const u_char *)ip + hlen; nh = ip->ip_p; #ifndef IPPROTO_SCTP #define IPPROTO_SCTP 132 #endif if (nh != IPPROTO_TCP && nh != IPPROTO_UDP && nh != IPPROTO_SCTP) { (void)printf("%s > %s: ", ipaddr_string(&ip->ip_src), ipaddr_string(&ip->ip_dst)); } again: switch (nh) { #ifndef IPPROTO_AH #define IPPROTO_AH 51 #endif case IPPROTO_AH: nh = *cp; advance = ah_print(cp, (const u_char *)ip); cp += advance; len -= advance; goto again; #ifndef IPPROTO_ESP #define IPPROTO_ESP 50 #endif case IPPROTO_ESP: { int enh, padlen; advance = esp_print(cp, (const u_char *)ip, &enh, &padlen); cp += advance; len -= advance + padlen; if (enh < 0) break; nh = enh & 0xff; goto again; } #ifndef IPPROTO_IPCOMP #define IPPROTO_IPCOMP 108 #endif case IPPROTO_IPCOMP: { int enh; advance = ipcomp_print(cp, (const u_char *)ip, &enh); cp += advance; len -= advance; if (enh < 0) break; nh = enh & 0xff; goto again; } case IPPROTO_SCTP: sctp_print(cp, (const u_char *)ip, len); break; case IPPROTO_TCP: tcp_print(cp, len, (const u_char *)ip, (off &~ 0x6000)); break; case IPPROTO_UDP: udp_print(cp, len, (const u_char *)ip, (off &~ 0x6000)); break; case IPPROTO_ICMP: icmp_print(cp, len, (const u_char *)ip); break; #ifndef IPPROTO_IGRP #define IPPROTO_IGRP 9 #endif case IPPROTO_IGRP: igrp_print(cp, len, (const u_char *)ip); break; case IPPROTO_ND: (void)printf(" nd %d", len); break; case IPPROTO_EGP: egp_print(cp, len, (const u_char *)ip); break; #ifndef IPPROTO_OSPF #define IPPROTO_OSPF 89 #endif case IPPROTO_OSPF: ospf_print(cp, len, (const u_char *)ip); break; #ifndef IPPROTO_IGMP #define IPPROTO_IGMP 2 #endif case IPPROTO_IGMP: igmp_print(cp, len); break; case 4: /* DVMRP multicast tunnel (ip-in-ip encapsulation) */ ip_print(cp, len); if (! vflag) { printf(" (ipip-proto-4)"); return; } break; #ifdef INET6 #ifndef IP6PROTO_ENCAP #define IP6PROTO_ENCAP 41 #endif case IP6PROTO_ENCAP: /* ip6-in-ip encapsulation */ ip6_print(cp, len); break; #endif /*INET6*/ #ifndef IPPROTO_GRE #define IPPROTO_GRE 47 #endif case IPPROTO_GRE: /* do it */ gre_print(cp, len); break; #ifndef IPPROTO_MOBILE #define IPPROTO_MOBILE 55 #endif case IPPROTO_MOBILE: mobile_print(cp, len); break; #ifndef IPPROTO_PIM #define IPPROTO_PIM 103 #endif case IPPROTO_PIM: pim_print(cp, len); break; #ifndef IPPROTO_VRRP #define IPPROTO_VRRP 112 #endif case IPPROTO_VRRP: vrrp_print(cp, len, ip->ip_ttl); break; default: if ((proto = getprotobynumber(nh)) != NULL) (void)printf(" %s", proto->p_name); else (void)printf(" ip-proto-%d", nh); printf(" %d", len); break; } } /* Ultra quiet now means that all this stuff should be suppressed */ /* res 3-Nov-98 */ if (qflag > 1) return; /* * for fragmented datagrams, print id:size@offset. On all * but the last stick a "+". For unfragmented datagrams, note * the don't fragment flag. */ len = len0; /* get the original length */ if (off & 0x3fff) { /* * if this isn't the first frag, we're missing the * next level protocol header. print the ip addr * and the protocol. */ if (off & 0x1fff) { (void)printf("%s > %s:", ipaddr_string(&ip->ip_src), ipaddr_string(&ip->ip_dst)); if ((proto = getprotobynumber(ip->ip_p)) != NULL) (void)printf(" %s", proto->p_name); else (void)printf(" ip-proto-%d", ip->ip_p); } #ifndef IP_MF #define IP_MF 0x2000 #endif /* IP_MF */ #ifndef IP_DF #define IP_DF 0x4000 #endif /* IP_DF */ (void)printf(" (frag %d:%u@%d%s)", ntohs(ip->ip_id), len, (off & 0x1fff) * 8, (off & IP_MF)? "+" : ""); } else if (off & IP_DF) (void)printf(" (DF)"); if (ip->ip_tos) { (void)printf(" [tos 0x%x", (int)ip->ip_tos); /* ECN bits */ if (ip->ip_tos & 0x03) { switch (ip->ip_tos & 0x03) { case 1: (void)printf(",ECT(1)"); break; case 2: (void)printf(",ECT(0)"); break; case 3: (void)printf(",CE"); } } (void)printf("] "); } if (ip->ip_ttl <= 1) (void)printf(" [ttl %d]", (int)ip->ip_ttl); if (vflag) { int sum; char *sep = ""; printf(" ("); if (ip->ip_ttl > 1) { (void)printf("%sttl %d", sep, (int)ip->ip_ttl); sep = ", "; } if ((off & 0x3fff) == 0) { (void)printf("%sid %d", sep, (int)ntohs(ip->ip_id)); sep = ", "; } (void)printf("%slen %d", sep, (int)ntohs(ip->ip_len)); sep = ", "; if ((u_char *)ip + hlen <= snapend) { sum = in_cksum((const u_short *)ip, hlen, 0); if (sum != 0) { (void)printf("%sbad cksum %x!", sep, ntohs(ip->ip_sum)); sep = ", "; } } if ((hlen -= sizeof(struct ip)) > 0) { (void)printf("%soptlen=%d", sep, hlen); ip_optprint((u_char *)(ip + 1), hlen); } printf(")"); } } void ipN_print(register const u_char *bp, register u_int length) { struct ip *ip, hdr; ip = (struct ip *)bp; if (length < 4) { (void)printf("truncated-ip %d", length); return; } memcpy (&hdr, (char *)ip, 4); switch (IP_V(&hdr)) { case 4: ip_print (bp, length); return; #ifdef INET6 case 6: ip6_print (bp, length); return; #endif default: (void)printf("unknown ip %d", IP_V(&hdr)); return; } }