X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/8c59e1bd9338a5f3fb68ef544f6fecd7415a0e39..05ec05a87b3a7c6983a16b5ae62d0f1512c4ce89:/print-ip.c diff --git a/print-ip.c b/print-ip.c index fc58f655..494eb295 100644 --- a/print-ip.c +++ b/print-ip.c @@ -21,7 +21,7 @@ #ifndef lint static const char rcsid[] _U_ = - "@(#) $Header: /tcpdump/master/tcpdump/print-ip.c,v 1.149 2005-04-07 00:28:17 mcr Exp $ (LBL)"; + "@(#) $Header: /tcpdump/master/tcpdump/print-ip.c,v 1.159 2007-09-14 01:29:28 guy Exp $ (LBL)"; #endif #ifdef HAVE_CONFIG_H @@ -50,6 +50,7 @@ struct tok ip_option_values[] = { { IPOPT_SSRR, "SSRR" }, { IPOPT_LSRR, "LSRR" }, { IPOPT_RA, "RA" }, + { IPOPT_RFC1393, "traceroute" }, { 0, NULL } }; @@ -73,9 +74,9 @@ ip_printroute(register const u_char *cp, u_int length) printf(" [bad ptr %u]", cp[2]); for (len = 3; len < length; len += 4) { - printf("%s", ipaddr_string(&cp[len])); + printf(" %s", ipaddr_string(&cp[len])); if (ptr > len) - printf (", "); + printf(","); } } @@ -86,7 +87,7 @@ ip_printroute(register const u_char *cp, u_int length) * This is used for UDP and TCP pseudo-header in the checksum * calculation. */ -u_int32_t +static u_int32_t ip_finddst(const struct ip *ip) { int length; @@ -128,6 +129,39 @@ trunc: return retval; } +/* + * Compute a V4-style checksum by building a pseudoheader. + */ +int +nextproto4_cksum(const struct ip *ip, const u_int8_t *data, + u_int len, u_int next_proto) +{ + struct phdr { + u_int32_t src; + u_int32_t dst; + u_char mbz; + u_char proto; + u_int16_t len; + } ph; + struct cksum_vec vec[2]; + + /* pseudo-header.. */ + ph.len = htons((u_int16_t)len); + ph.mbz = 0; + ph.proto = next_proto; + memcpy(&ph.src, &ip->ip_src.s_addr, sizeof(u_int32_t)); + if (IP_HL(ip) == 5) + memcpy(&ph.dst, &ip->ip_dst.s_addr, sizeof(u_int32_t)); + else + ph.dst = ip_finddst(ip); + + vec[0].ptr = (const u_int8_t *)(void *)&ph; + vec[0].len = sizeof(ph); + vec[1].ptr = data; + vec[1].len = len; + return (in_cksum(vec, 2)); +} + static void ip_printts(register const u_char *cp, u_int length) { @@ -137,17 +171,17 @@ ip_printts(register const u_char *cp, u_int length) const char *type; if (length < 4) { - printf("[bad length %d]", length); + printf("[bad length %u]", length); return; } printf(" TS{"); hoplen = ((cp[3]&0xF) != IPOPT_TS_TSONLY) ? 8 : 4; if ((length - 4) & (hoplen-1)) - printf("[bad length %d]", length); + printf("[bad length %u]", length); ptr = cp[2] - 1; len = 0; if (ptr < 4 || ((ptr - 4) & (hoplen-1)) || ptr > length + 1) - printf("[bad ptr %d]", cp[2]); + printf("[bad ptr %u]", cp[2]); switch (cp[3]&0xF) { case IPOPT_TS_TSONLY: printf("TSONLY"); @@ -197,29 +231,37 @@ static void ip_optprint(register const u_char *cp, u_int length) { register u_int option_len; + const char *sep = ""; for (; length > 0; cp += option_len, length -= option_len) { u_int option_code; + printf("%s", sep); + sep = ","; + TCHECK(*cp); option_code = *cp; + printf("%s", + tok2str(ip_option_values,"unknown %u",option_code)); + if (option_code == IPOPT_NOP || option_code == IPOPT_EOL) option_len = 1; else { TCHECK(cp[1]); - option_len = cp[1]; + option_len = cp[1]; + if (option_len < 2) { + printf(" [bad length %u]", option_len); + return; + } } - printf("%s (%u) len %u", - tok2str(ip_option_values,"unknown",option_code), - option_code, - option_len); - - if (option_len < 2) - return; + if (option_len > length) { + printf(" [bad length %u]", option_len); + return; + } TCHECK2(*cp, option_len); @@ -234,13 +276,17 @@ ip_optprint(register const u_char *cp, u_int length) case IPOPT_RR: /* fall through */ case IPOPT_SSRR: case IPOPT_LSRR: - ip_printroute( cp, option_len); + ip_printroute(cp, option_len); break; case IPOPT_RA: + if (option_len < 4) { + printf(" [bad length %u]", option_len); + break; + } TCHECK(cp[3]); if (EXTRACT_16BITS(&cp[2]) != 0) - printf("value %u", EXTRACT_16BITS(&cp[2])); + printf(" value %u", EXTRACT_16BITS(&cp[2])); break; case IPOPT_NOP: /* nothing to print - fall through */ @@ -255,98 +301,6 @@ trunc: printf("[|ip]"); } -/* - * 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); -} - -/* - * Given the host-byte-order value of the checksum field in a packet - * header, and the network-byte-order computed checksum of the data - * that the checksum covers (including the checksum itself), compute - * what the checksum field *should* have been. - */ -u_int16_t -in_cksum_shouldbe(u_int16_t sum, u_int16_t computed_sum) -{ - u_int32_t shouldbe; - - /* - * The value that should have gone into the checksum field - * is the negative of the value gotten by summing up everything - * *but* the checksum field. - * - * We can compute that by subtracting the value of the checksum - * field from the sum of all the data in the packet, and then - * computing the negative of that value. - * - * "sum" is the value of the checksum field, and "computed_sum" - * is the negative of the sum of all the data in the packets, - * so that's -(-computed_sum - sum), or (sum + computed_sum). - * - * All the arithmetic in question is one's complement, so the - * addition must include an end-around carry; we do this by - * doing the arithmetic in 32 bits (with no sign-extension), - * and then adding the upper 16 bits of the sum, which contain - * the carry, to the lower 16 bits of the sum, and then do it - * again in case *that* sum produced a carry. - * - * As RFC 1071 notes, the checksum can be computed without - * byte-swapping the 16-bit words; summing 16-bit words - * on a big-endian machine gives a big-endian checksum, which - * can be directly stuffed into the big-endian checksum fields - * in protocol headers, and summing words on a little-endian - * machine gives a little-endian checksum, which must be - * byte-swapped before being stuffed into a big-endian checksum - * field. - * - * "computed_sum" is a network-byte-order value, so we must put - * it in host byte order before subtracting it from the - * host-byte-order value from the header; the adjusted checksum - * will be in host byte order, which is what we'll return. - */ - shouldbe = sum; - shouldbe += ntohs(computed_sum); - shouldbe = (shouldbe & 0xFFFF) + (shouldbe >> 16); - shouldbe = (shouldbe & 0xFFFF) + (shouldbe >> 16); - return shouldbe; -} - -#ifndef IP_MF -#define IP_MF 0x2000 -#endif /* IP_MF */ -#ifndef IP_DF -#define IP_DF 0x4000 -#endif /* IP_DF */ #define IP_RES 0x8000 static struct tok ip_frag_values[] = { @@ -369,6 +323,7 @@ ip_print_demux(netdissect_options *ndo, struct ip_print_demux_state *ipds) { struct protoent *proto; + struct cksum_vec vec[1]; again: switch (ipds->nh) { @@ -395,7 +350,7 @@ again: ipds->nh = enh & 0xff; goto again; } - + case IPPROTO_IPCOMP: { int enh; @@ -411,23 +366,29 @@ again: case IPPROTO_SCTP: sctp_print(ipds->cp, (const u_char *)ipds->ip, ipds->len); break; - + + case IPPROTO_DCCP: + dccp_print(ipds->cp, (const u_char *)ipds->ip, ipds->len); + break; + case IPPROTO_TCP: + /* pass on the MF bit plus the offset to detect fragments */ tcp_print(ipds->cp, ipds->len, (const u_char *)ipds->ip, - (ipds->off &~ 0x6000)); + ipds->off & (IP_MF|IP_OFFMASK)); break; - + case IPPROTO_UDP: + /* pass on the MF bit plus the offset to detect fragments */ udp_print(ipds->cp, ipds->len, (const u_char *)ipds->ip, - (ipds->off &~ 0x6000)); + ipds->off & (IP_MF|IP_OFFMASK)); break; - + case IPPROTO_ICMP: /* pass on the MF bit plus the offset to detect fragments */ icmp_print(ipds->cp, ipds->len, (const u_char *)ipds->ip, - (ipds->off & 0x3fff)); + ipds->off & (IP_MF|IP_OFFMASK)); break; - + case IPPROTO_PIGP: /* * XXX - the current IANA protocol number assignments @@ -444,11 +405,11 @@ again: */ igrp_print(ipds->cp, ipds->len, (const u_char *)ipds->ip); break; - + case IPPROTO_EIGRP: eigrp_print(ipds->cp, ipds->len); break; - + case IPPROTO_ND: ND_PRINT((ndo, " nd %d", ipds->len)); break; @@ -467,17 +428,17 @@ again: case IPPROTO_IPV4: /* DVMRP multicast tunnel (ip-in-ip encapsulation) */ - ip_print(gndo, ipds->cp, ipds->len); + ip_print(ndo, ipds->cp, ipds->len); if (! vflag) { ND_PRINT((ndo, " (ipip-proto-4)")); return; } break; - + #ifdef INET6 case IPPROTO_IPV6: /* ip6-in-ip encapsulation */ - ip6_print(ipds->cp, ipds->len); + ip6_print(ndo, ipds->cp, ipds->len); break; #endif /*INET6*/ @@ -495,15 +456,33 @@ again: break; case IPPROTO_PIM: - pim_print(ipds->cp, ipds->len); + vec[0].ptr = ipds->cp; + vec[0].len = ipds->len; + pim_print(ipds->cp, ipds->len, in_cksum(vec, 1)); break; case IPPROTO_VRRP: - vrrp_print(ipds->cp, ipds->len, ipds->ip->ip_ttl); + if (packettype == PT_CARP) { + if (vflag) + (void)printf("carp %s > %s: ", + ipaddr_string(&ipds->ip->ip_src), + ipaddr_string(&ipds->ip->ip_dst)); + carp_print(ipds->cp, ipds->len, ipds->ip->ip_ttl); + } else { + if (vflag) + (void)printf("vrrp %s > %s: ", + ipaddr_string(&ipds->ip->ip_src), + ipaddr_string(&ipds->ip->ip_dst)); + vrrp_print(ipds->cp, ipds->len, ipds->ip->ip_ttl); + } + break; + + case IPPROTO_PGM: + pgm_print(ipds->cp, ipds->len, (const u_char *)ipds->ip); break; default: - if ((proto = getprotobynumber(ipds->nh)) != NULL) + if (ndo->ndo_nflag==0 && (proto = getprotobynumber(ipds->nh)) != NULL) ND_PRINT((ndo, " %s", proto->p_name)); else ND_PRINT((ndo, " ip-proto-%d", ipds->nh)); @@ -511,7 +490,7 @@ again: break; } } - + void ip_print_inner(netdissect_options *ndo, const u_char *bp, @@ -543,6 +522,7 @@ ip_print(netdissect_options *ndo, struct ip_print_demux_state *ipds=&ipd; const u_char *ipend; u_int hlen; + struct cksum_vec vec[1]; u_int16_t sum, ip_sum; struct protoent *proto; @@ -555,7 +535,7 @@ ip_print(netdissect_options *ndo, else if (!eflag) printf("IP "); - if ((u_char *)(ipds->ip + 1) > snapend) { + if ((u_char *)(ipds->ip + 1) > ndo->ndo_snapend) { printf("[|ip]"); return; } @@ -593,8 +573,8 @@ ip_print(netdissect_options *ndo, * Cut off the snapshot length to the end of the IP payload. */ ipend = bp + ipds->len; - if (ipend < snapend) - snapend = ipend; + if (ipend < ndo->ndo_snapend) + ndo->ndo_snapend = ipend; ipds->len -= hlen; @@ -617,7 +597,7 @@ ip_print(netdissect_options *ndo, } if (ipds->ip->ip_ttl >= 1) - (void)printf(", ttl %3u", ipds->ip->ip_ttl); + (void)printf(", ttl %u", ipds->ip->ip_ttl); /* * for the firewall guys, print id, offset. @@ -625,23 +605,25 @@ ip_print(netdissect_options *ndo, * For unfragmented datagrams, note the don't fragment flag. */ - (void)printf(", id %u, offset %u, flags [%s], proto: %s (%u)", + (void)printf(", id %u, offset %u, flags [%s], proto %s (%u)", EXTRACT_16BITS(&ipds->ip->ip_id), (ipds->off & 0x1fff) * 8, - bittok2str(ip_frag_values, "none", ipds->off&0xe000 ), + bittok2str(ip_frag_values, "none", ipds->off&0xe000), tok2str(ipproto_values,"unknown",ipds->ip->ip_p), ipds->ip->ip_p); - (void)printf(", length: %u", EXTRACT_16BITS(&ipds->ip->ip_len)); + (void)printf(", length %u", EXTRACT_16BITS(&ipds->ip->ip_len)); if ((hlen - sizeof(struct ip)) > 0) { - printf(", options ( "); + printf(", options ("); ip_optprint((u_char *)(ipds->ip + 1), hlen - sizeof(struct ip)); - printf(" )"); + printf(")"); } - if ((u_char *)ipds->ip + hlen <= snapend) { - sum = in_cksum((const u_short *)ipds->ip, hlen, 0); + if (!Kflag && (u_char *)ipds->ip + hlen <= ndo->ndo_snapend) { + vec[0].ptr = (const u_int8_t *)(void *)ipds->ip; + vec[0].len = hlen; + sum = in_cksum(vec, 1); if (sum != 0) { ip_sum = EXTRACT_16BITS(&ipds->ip->ip_sum); (void)printf(", bad cksum %x (->%x)!", ip_sum, @@ -649,7 +631,7 @@ ip_print(netdissect_options *ndo, } } - printf(") "); + printf(")\n "); } /* @@ -661,7 +643,7 @@ ip_print(netdissect_options *ndo, ipds->nh = ipds->ip->ip_p; if (ipds->nh != IPPROTO_TCP && ipds->nh != IPPROTO_UDP && - ipds->nh != IPPROTO_SCTP) { + ipds->nh != IPPROTO_SCTP && ipds->nh != IPPROTO_DCCP) { (void)printf("%s > %s: ", ipaddr_string(&ipds->ip->ip_src), ipaddr_string(&ipds->ip->ip_dst)); @@ -679,11 +661,11 @@ ip_print(netdissect_options *ndo, if (ipds->off & 0x1fff) { (void)printf("%s > %s:", ipaddr_string(&ipds->ip->ip_src), ipaddr_string(&ipds->ip->ip_dst)); - if ((proto = getprotobynumber(ipds->ip->ip_p)) != NULL) + if (!ndo->ndo_nflag && (proto = getprotobynumber(ipds->ip->ip_p)) != NULL) (void)printf(" %s", proto->p_name); else (void)printf(" ip-proto-%d", ipds->ip->ip_p); - } + } } } @@ -704,7 +686,7 @@ ipN_print(register const u_char *bp, register u_int length) return; #ifdef INET6 case 6: - ip6_print (bp, length); + ip6_print (gndo, bp, length); return; #endif default: