X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/2d86b23ecde8e2e815ace35e5060856fa61a7e36..f5877da285f3e030d59a28236295573f27e344bc:/print-ip.c diff --git a/print-ip.c b/print-ip.c index 2951875e..5edc6221 100644 --- a/print-ip.c +++ b/print-ip.c @@ -1,7 +1,5 @@ -/* $NetBSD: print-ip.c,v 1.4 1995/04/24 13:27:43 cgd Exp $ */ - /* - * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994 + * 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 @@ -21,363 +19,510 @@ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. */ -#ifndef lint -static const char rcsid[] = - "@(#) $Header: /tcpdump/master/tcpdump/print-ip.c,v 1.68 1999-10-17 21:56:54 mcr Exp $ (LBL)"; -#endif - -#include -#include -#include -#include - -#include -#include -#include -#include -#include - -#include -#ifdef __STDC__ -#include -#endif -#include - -#include "interface.h" +/* \summary: IP printer */ + +#include + +#include "netdissect-stdinc.h" + +#include "netdissect.h" #include "addrtoname.h" +#include "extract.h" -static void -igmp_print(register const u_char *bp, register int len, - register const u_char *bp2) -{ - register const struct ip *ip; - register const u_char *ep; +#include "ip.h" +#include "ipproto.h" - ip = (const struct ip *)bp2; - ep = (const u_char *)snapend; - (void)printf("%s > %s: ", - ipaddr_string(&ip->ip_src), - ipaddr_string(&ip->ip_dst)); - if (bp + 7 > ep) { - (void)printf("[|igmp]"); - return; - } - switch (bp[0] & 0xf) { - case 1: - (void)printf("igmp query"); - if (*(int *)&bp[4]) - (void)printf(" [gaddr %s]", ipaddr_string(&bp[4])); - if (len != 8) - (void)printf(" [len %d]", len); - break; - case 2: - (void)printf("igmp report %s", ipaddr_string(&bp[4])); - if (len != 8) - (void)printf(" [len %d]", len); - break; - case 3: - (void)printf("igmp dvmrp %s", ipaddr_string(&bp[4])); - if (len < 8) - (void)printf(" [len %d]", len); - break; - default: - (void)printf("igmp-%d", bp[0] & 0xf); - break; - } - if ((bp[0] >> 4) != 1) - (void)printf(" [v%d]", bp[0] >> 4); - if (bp[1]) - (void)printf(" [b1=0x%x]", bp[1]); -} +static const struct tok ip_option_values[] = { + { IPOPT_EOL, "EOL" }, + { IPOPT_NOP, "NOP" }, + { IPOPT_TS, "timestamp" }, + { IPOPT_SECURITY, "security" }, + { IPOPT_RR, "RR" }, + { IPOPT_SSRR, "SSRR" }, + { IPOPT_LSRR, "LSRR" }, + { IPOPT_RA, "RA" }, + { IPOPT_RFC1393, "traceroute" }, + { 0, NULL } +}; /* * print the recorded route in an IP RR, LSRR or SSRR option. */ -static void -ip_printroute(const char *type, register const u_char *cp, int length) +static int +ip_printroute(netdissect_options *ndo, + const u_char *cp, u_int length) { - int ptr = cp[2] - 1; - int len; + u_int ptr; + u_int len; - printf(" %s{", type); + if (length < 3) { + ND_PRINT(" [bad length %u]", length); + return (0); + } if ((length + 1) & 3) - printf(" [bad length %d]", length); + ND_PRINT(" [bad length %u]", length); + ptr = GET_U_1(cp + 2) - 1; if (ptr < 3 || ((ptr + 1) & 3) || ptr > length + 1) - printf(" [bad ptr %d]", cp[2]); + ND_PRINT(" [bad ptr %u]", GET_U_1(cp + 2)); - type = ""; for (len = 3; len < length; len += 4) { - if (ptr == len) - type = "#"; -#ifdef TCPDUMP_ALIGN - { - struct in_addr addr; - bcopy((char *)&cp[len], (char *)&addr, sizeof(addr)); - printf("%s%s", type, ipaddr_string(&addr)); + ND_TCHECK_4(cp + len); /* Needed to print the IP addresses */ + ND_PRINT(" %s", GET_IPADDR_STRING(cp + len)); + if (ptr > len) + ND_PRINT(","); + } + return (0); + +trunc: + return (-1); +} + +/* + * If source-routing is present and valid, return the final destination. + * Otherwise, return IP destination. + * + * This is used for UDP and TCP pseudo-header in the checksum + * calculation. + */ +static uint32_t +ip_finddst(netdissect_options *ndo, + const struct ip *ip) +{ + u_int length; + u_int len; + const u_char *cp; + + cp = (const u_char *)(ip + 1); + length = IP_HL(ip) * 4; + if (length < sizeof(struct ip)) + goto trunc; + length -= sizeof(struct ip); + + for (; length != 0; cp += len, length -= len) { + int tt; + + tt = GET_U_1(cp); + if (tt == IPOPT_EOL) + break; + else if (tt == IPOPT_NOP) + len = 1; + else { + len = GET_U_1(cp + 1); + if (len < 2) + break; + } + if (length < len) + goto trunc; + ND_TCHECK_LEN(cp, len); + switch (tt) { + + case IPOPT_SSRR: + case IPOPT_LSRR: + if (len < 7) + break; + return (GET_IPV4_TO_NETWORK_ORDER(cp + len - 4)); } -#else - printf("%s%s", type, ipaddr_string(&cp[len])); -#endif + } +trunc: + return (GET_IPV4_TO_NETWORK_ORDER(ip->ip_dst)); +} + +/* + * Compute a V4-style checksum by building a pseudoheader. + */ +uint16_t +nextproto4_cksum(netdissect_options *ndo, + const struct ip *ip, const uint8_t *data, + u_int len, u_int covlen, uint8_t next_proto) +{ + struct phdr { + uint32_t src; + uint32_t dst; + uint8_t mbz; + uint8_t proto; + uint16_t len; + } ph; + struct cksum_vec vec[2]; + + /* pseudo-header.. */ + ph.len = htons((uint16_t)len); + ph.mbz = 0; + ph.proto = next_proto; + ph.src = GET_IPV4_TO_NETWORK_ORDER(ip->ip_src); + if (IP_HL(ip) == 5) + ph.dst = GET_IPV4_TO_NETWORK_ORDER(ip->ip_dst); + else + ph.dst = ip_finddst(ndo, ip); + + vec[0].ptr = (const uint8_t *)(void *)&ph; + vec[0].len = sizeof(ph); + vec[1].ptr = data; + vec[1].len = covlen; + return (in_cksum(vec, 2)); +} + +static int +ip_printts(netdissect_options *ndo, + const u_char *cp, u_int length) +{ + u_int ptr; + u_int len; + u_int hoplen; + const char *type; + + if (length < 4) { + ND_PRINT("[bad length %u]", length); + return (0); + } + ND_PRINT(" TS{"); + hoplen = ((GET_U_1(cp + 3) & 0xF) != IPOPT_TS_TSONLY) ? 8 : 4; + if ((length - 4) & (hoplen-1)) + ND_PRINT("[bad length %u]", length); + ptr = GET_U_1(cp + 2) - 1; + len = 0; + if (ptr < 4 || ((ptr - 4) & (hoplen-1)) || ptr > length + 1) + ND_PRINT("[bad ptr %u]", GET_U_1(cp + 2)); + switch (GET_U_1(cp + 3)&0xF) { + case IPOPT_TS_TSONLY: + ND_PRINT("TSONLY"); + break; + case IPOPT_TS_TSANDADDR: + ND_PRINT("TS+ADDR"); + break; + case IPOPT_TS_PRESPEC: + ND_PRINT("PRESPEC"); + break; + default: + ND_PRINT("[bad ts type %u]", GET_U_1(cp + 3)&0xF); + goto done; + } + + type = " "; + for (len = 4; len < length; len += hoplen) { + if (ptr == len) + type = " ^ "; + ND_TCHECK_LEN(cp + len, hoplen); + ND_PRINT("%s%u@%s", type, GET_BE_U_4(cp + len + hoplen - 4), + hoplen!=8 ? "" : GET_IPADDR_STRING(cp + len)); type = " "; } - printf("%s}", ptr == len? "#" : ""); + +done: + ND_PRINT("%s", ptr == len ? " ^ " : ""); + + if (GET_U_1(cp + 3) >> 4) + ND_PRINT(" [%u hops not recorded]} ", GET_U_1(cp + 3)>>4); + else + ND_PRINT("}"); + return (0); + +trunc: + return (-1); } /* * print IP options. + If truncated return -1, else 0. */ -static void -ip_optprint(register const u_char *cp, int length) +static int +ip_optprint(netdissect_options *ndo, + const u_char *cp, u_int length) { - int len; + u_int option_len; + const char *sep = ""; - for (; length > 0; cp += len, length -= len) { - int tt = *cp; + for (; length > 0; cp += option_len, length -= option_len) { + u_int option_code; - len = (tt == IPOPT_NOP || tt == IPOPT_EOL) ? 1 : cp[1]; - if (&cp[1] >= snapend || cp + len > snapend) { - printf("[|ip]"); - return; - } - switch (tt) { + ND_PRINT("%s", sep); + sep = ","; - case IPOPT_EOL: - printf(" EOL"); - if (length > 1) - printf("-%d", length - 1); - return; + option_code = GET_U_1(cp); - case IPOPT_NOP: - printf(" NOP"); - break; + ND_PRINT("%s", + tok2str(ip_option_values,"unknown %u",option_code)); - case IPOPT_TS: - printf(" TS{%d}", len); - break; + if (option_code == IPOPT_NOP || + option_code == IPOPT_EOL) + option_len = 1; - case IPOPT_SECURITY: - printf(" SECURITY{%d}", len); - break; + else { + option_len = GET_U_1(cp + 1); + if (option_len < 2) { + ND_PRINT(" [bad length %u]", option_len); + return 0; + } + } + + if (option_len > length) { + ND_PRINT(" [bad length %u]", option_len); + return 0; + } - case IPOPT_RR: - printf(" RR{%d}=", len); - ip_printroute("RR", cp, len); + ND_TCHECK_LEN(cp, option_len); + + switch (option_code) { + case IPOPT_EOL: + return 0; + + case IPOPT_TS: + if (ip_printts(ndo, cp, option_len) == -1) + goto trunc; break; + case IPOPT_RR: /* fall through */ case IPOPT_SSRR: - ip_printroute("SSRR", cp, len); + case IPOPT_LSRR: + if (ip_printroute(ndo, cp, option_len) == -1) + goto trunc; break; - case IPOPT_LSRR: - ip_printroute("LSRR", cp, len); + case IPOPT_RA: + if (option_len < 4) { + ND_PRINT(" [bad length %u]", option_len); + break; + } + ND_TCHECK_1(cp + 3); + if (GET_BE_U_2(cp + 2) != 0) + ND_PRINT(" value %u", GET_BE_U_2(cp + 2)); break; + case IPOPT_NOP: /* nothing to print - fall through */ + case IPOPT_SECURITY: default: - printf(" IPOPT-%d{%d}", cp[0], len); break; } } -} - -/* - * compute an IP header checksum. - * don't modifiy the packet. - */ -static int -in_cksum(const struct ip *ip) -{ - register const u_short *sp = (u_short *)ip; - register u_int32 sum = 0; - register int count; + return 0; - /* - * No need for endian conversions. - */ - for (count = ip->ip_hl * 2; --count >= 0; ) - sum += *sp++; - while (sum > 0xffff) - sum = (sum & 0xffff) + (sum >> 16); - sum = ~sum & 0xffff; - - return (sum); +trunc: + return -1; } +#define IP_RES 0x8000 + +static const struct tok ip_frag_values[] = { + { IP_MF, "+" }, + { IP_DF, "DF" }, + { IP_RES, "rsvd" }, /* The RFC3514 evil ;-) bit */ + { 0, NULL } +}; -void -print_ipproto(u_int proto, const struct ip *ip, - const u_char *cp, int len) -{ - switch (proto) { - case IPPROTO_TCP: - tcp_print(cp, len, (const u_char *)ip); - break; - case IPPROTO_UDP: - udp_print(cp, len, (const u_char *)ip); - break; - case IPPROTO_ICMP: - icmp_print(cp, (const u_char *)ip); - break; - case IPPROTO_ND: - (void)printf("%s > %s:", ipaddr_string(&ip->ip_src), - ipaddr_string(&ip->ip_dst)); - (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, (const u_char *)ip); - break; -#ifndef IPPROTO_ENCAP -#define IPPROTO_ENCAP 4 -#endif - case IPPROTO_ENCAP: - /* ip-in-ip encapsulation */ - if (vflag) - (void)printf("%s > %s: ", - ipaddr_string(&ip->ip_src), - ipaddr_string(&ip->ip_dst)); - ip_print(cp, len); - if (! vflag) { - printf(" (encap)"); - return; - } - break; - -#ifndef IPPROTO_ESP -#define IPPROTO_ESP 50 -#endif - case IPPROTO_ESP: - esp_print(cp, len, (const u_char *)ip); - break; - -#ifndef IPPROTO_AH -#define IPPROTO_AH 51 -#endif - case IPPROTO_AH: - ah_print(cp, len, (const u_char *)ip); - break; - - default: - (void)printf("%s > %s:", ipaddr_string(&ip->ip_src), - ipaddr_string(&ip->ip_dst)); - (void)printf(" ip-proto-%d %d", proto, len); - break; - } -} /* * print an IP datagram. */ void -ip_print(register const u_char *bp, register int length) +ip_print(netdissect_options *ndo, + const u_char *bp, + const u_int length) { - register const struct ip *ip; - register int hlen; - register int len; - register int off; - register const u_char *cp; - + const struct ip *ip; + u_int off; + u_int hlen; + u_int len; + struct cksum_vec vec[1]; + uint8_t ip_tos, ip_ttl, ip_proto; + uint16_t sum, ip_sum; + const char *p_name; + int truncated = 0; + int presumed_tso = 0; + + ndo->ndo_protocol = "ip"; ip = (const struct ip *)bp; -#ifdef TCPDUMP_ALIGN - /* - * The IP header is not word aligned, so copy into abuf. - * This will never happen with BPF. It does happen raw packet - * dumps from -r. - */ - if ((long)ip & (sizeof(long)-1)) { - static u_char *abuf; - - if (abuf == 0) - abuf = (u_char *)malloc(snaplen); - bcopy((char *)ip, (char *)abuf, min(length, snaplen)); - snapend += abuf - (u_char *)ip; - packetp = abuf; - ip = (struct ip *)abuf; + + if (!ndo->ndo_eflag) { + nd_print_protocol_caps(ndo); + ND_PRINT(" "); } -#endif - if ((u_char *)(ip + 1) > snapend) { - printf("[|ip]"); - return; + + ND_ICHECK_ZU(length, <, sizeof (struct ip)); + ND_ICHECKMSG_U("version", IP_V(ip), !=, 4); + + hlen = IP_HL(ip) * 4; + ND_ICHECKMSG_ZU("header length", hlen, <, sizeof (struct ip)); + + len = GET_BE_U_2(ip->ip_len); + if (len > length) { + ND_PRINT("[total length %u > length %u]", len, length); + nd_print_invalid(ndo); + ND_PRINT(" "); } - if (length < sizeof (struct ip)) { - (void)printf("truncated-ip %d", length); - return; + if (len == 0) { + /* we guess that it is a TSO send */ + len = length; + presumed_tso = 1; + } else + ND_ICHECKMSG_U("total length", len, <, hlen); + + ND_TCHECK_SIZE(ip); + /* + * Cut off the snapshot length to the end of the IP payload. + */ + if (!nd_push_snaplen(ndo, bp, len)) { + (*ndo->ndo_error)(ndo, S_ERR_ND_MEM_ALLOC, + "%s: can't push snaplen on buffer stack", __func__); } - hlen = ip->ip_hl * 4; - len = ntohs(ip->ip_len); - if (length < len) - (void)printf("truncated-ip - %d bytes missing!", - len - length); len -= hlen; - /* - * 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; - print_ipproto(ip->ip_p, ip, cp, len); + off = GET_BE_U_2(ip->ip_off); + + ip_proto = GET_U_1(ip->ip_p); + + if (ndo->ndo_vflag) { + ip_tos = GET_U_1(ip->ip_tos); + ND_PRINT("(tos 0x%x", ip_tos); + /* ECN bits */ + switch (ip_tos & 0x03) { + + case 0: + break; + + case 1: + ND_PRINT(",ECT(1)"); + break; + + case 2: + ND_PRINT(",ECT(0)"); + break; + + case 3: + ND_PRINT(",CE"); + break; + } + + ip_ttl = GET_U_1(ip->ip_ttl); + if (ip_ttl >= 1) + ND_PRINT(", ttl %u", ip_ttl); + + /* + * for the firewall guys, print id, offset. + * On all but the last stick a "+" in the flags portion. + * For unfragmented datagrams, note the don't fragment flag. + */ + ND_PRINT(", id %u, offset %u, flags [%s], proto %s (%u)", + GET_BE_U_2(ip->ip_id), + (off & IP_OFFMASK) * 8, + bittok2str(ip_frag_values, "none", off & (IP_RES|IP_DF|IP_MF)), + tok2str(ipproto_values, "unknown", ip_proto), + ip_proto); + + if (presumed_tso) + ND_PRINT(", length %u [was 0, presumed TSO]", length); + else + ND_PRINT(", length %u", GET_BE_U_2(ip->ip_len)); + + if ((hlen - sizeof(struct ip)) > 0) { + ND_PRINT(", options ("); + if (ip_optprint(ndo, (const u_char *)(ip + 1), + hlen - sizeof(struct ip)) == -1) { + ND_PRINT(" [truncated-option]"); + truncated = 1; + } + ND_PRINT(")"); + } + + if (!ndo->ndo_Kflag && (const u_char *)ip + hlen <= ndo->ndo_snapend) { + vec[0].ptr = (const uint8_t *)(const void *)ip; + vec[0].len = hlen; + sum = in_cksum(vec, 1); + if (sum != 0) { + ip_sum = GET_BE_U_2(ip->ip_sum); + ND_PRINT(", bad cksum %x (->%x)!", ip_sum, + in_cksum_shouldbe(ip_sum, sum)); + } + } + + ND_PRINT(")\n "); + if (truncated) { + ND_PRINT("%s > %s: ", + GET_IPADDR_STRING(ip->ip_src), + GET_IPADDR_STRING(ip->ip_dst)); + nd_print_trunc(ndo); + nd_pop_packet_info(ndo); + return; + } } + /* - * for fragmented datagrams, print id:size@offset. On all - * but the last stick a "+". For unfragmented datagrams, note - * the don't fragment flag. + * If this is fragment zero, hand it to the next higher + * level protocol. Let them know whether there are more + * fragments. */ - if (off & 0x3fff) { + if ((off & IP_OFFMASK) == 0) { + uint8_t nh = GET_U_1(ip->ip_p); + + if (nh != IPPROTO_TCP && nh != IPPROTO_UDP && + nh != IPPROTO_SCTP && nh != IPPROTO_DCCP) { + ND_PRINT("%s > %s: ", + GET_IPADDR_STRING(ip->ip_src), + GET_IPADDR_STRING(ip->ip_dst)); + } /* - * if this isn't the first frag, we're missing the - * next level protocol header. print the ip addr. + * Do a bounds check before calling ip_demux_print(). + * At least the header data is required. */ - if (off & 0x1fff) - (void)printf("%s > %s:", ipaddr_string(&ip->ip_src), - ipaddr_string(&ip->ip_dst)); - (void)printf(" (frag %d:%d@%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); - 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 = ", "; - } - sum = in_cksum(ip); - if (sum != 0) { - (void)printf("%sbad cksum %x!", sep, - ntohs(ip->ip_sum)); - sep = ", "; + if (!ND_TTEST_LEN((const u_char *)ip, hlen)) { + ND_PRINT(" [remaining caplen(%u) < header length(%u)]", + ND_BYTES_AVAILABLE_AFTER((const u_char *)ip), + hlen); + nd_trunc_longjmp(ndo); } - if ((hlen -= sizeof(struct ip)) > 0) { - (void)printf("%soptlen=%d", sep, hlen); - ip_optprint((u_char *)(ip + 1), hlen); + ip_demux_print(ndo, (const u_char *)ip + hlen, len, 4, + off & IP_MF, GET_U_1(ip->ip_ttl), nh, bp); + } else { + /* + * Ultra quiet now means that all this stuff should be + * suppressed. + */ + if (ndo->ndo_qflag > 1) { + nd_pop_packet_info(ndo); + return; } - printf(")"); + + /* + * This isn't the first frag, so we're missing the + * next level protocol header. print the ip addr + * and the protocol. + */ + ND_PRINT("%s > %s:", GET_IPADDR_STRING(ip->ip_src), + GET_IPADDR_STRING(ip->ip_dst)); + if (!ndo->ndo_nflag && (p_name = netdb_protoname(ip_proto)) != NULL) + ND_PRINT(" %s", p_name); + else + ND_PRINT(" ip-proto-%u", ip_proto); + } + nd_pop_packet_info(ndo); + return; + +trunc: + nd_print_trunc(ndo); + return; + +invalid: + nd_print_invalid(ndo); +} + +void +ipN_print(netdissect_options *ndo, const u_char *bp, u_int length) +{ + ndo->ndo_protocol = "ipn"; + if (length < 1) { + ND_PRINT("truncated-ip %u", length); + return; + } + + switch (GET_U_1(bp) & 0xF0) { + case 0x40: + ip_print(ndo, bp, length); + break; + case 0x60: + ip6_print(ndo, bp, length); + break; + default: + ND_PRINT("unknown ip %u", (GET_U_1(bp) & 0xF0) >> 4); + break; } }