diff options
Diffstat (limited to 'print-tcp.c')
-rw-r--r-- | print-tcp.c | 926 |
1 files changed, 926 insertions, 0 deletions
diff --git a/print-tcp.c b/print-tcp.c new file mode 100644 index 000000000000..b80a2f264d45 --- /dev/null +++ b/print-tcp.c @@ -0,0 +1,926 @@ +/* $NetBSD: print-tcp.c,v 1.9 2007/07/26 18:15:12 plunky Exp $ */ + +/* + * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997 + * The Regents of the University of California. All rights reserved. + * + * Copyright (c) 1999-2004 The tcpdump.org project + * + * 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. + */ + +/* \summary: TCP printer */ + +#ifndef lint +#else +__RCSID("$NetBSD: print-tcp.c,v 1.8 2007/07/24 11:53:48 drochner Exp $"); +#endif + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include <netdissect-stdinc.h> + +#include <stdlib.h> +#include <string.h> + +#include "netdissect.h" +#include "addrtoname.h" +#include "extract.h" + +#include "tcp.h" + +#include "ip.h" +#include "ip6.h" +#include "ipproto.h" +#include "rpc_auth.h" +#include "rpc_msg.h" + +#ifdef HAVE_LIBCRYPTO +#include <openssl/md5.h> +#include "signature.h" + +static int tcp_verify_signature(netdissect_options *ndo, + const struct ip *ip, const struct tcphdr *tp, + const u_char *data, int length, const u_char *rcvsig); +#endif + +static void print_tcp_rst_data(netdissect_options *, register const u_char *sp, u_int length); +static void print_tcp_fastopen_option(netdissect_options *ndo, register const u_char *cp, + u_int datalen, int exp); + +#define MAX_RST_DATA_LEN 30 + + +struct tha { + struct in_addr src; + struct in_addr dst; + u_int port; +}; + +struct tcp_seq_hash { + struct tcp_seq_hash *nxt; + struct tha addr; + tcp_seq seq; + tcp_seq ack; +}; + +struct tha6 { + struct in6_addr src; + struct in6_addr dst; + u_int port; +}; + +struct tcp_seq_hash6 { + struct tcp_seq_hash6 *nxt; + struct tha6 addr; + tcp_seq seq; + tcp_seq ack; +}; + +#define TSEQ_HASHSIZE 919 + +/* These tcp optinos do not have the size octet */ +#define ZEROLENOPT(o) ((o) == TCPOPT_EOL || (o) == TCPOPT_NOP) + +static struct tcp_seq_hash tcp_seq_hash4[TSEQ_HASHSIZE]; +static struct tcp_seq_hash6 tcp_seq_hash6[TSEQ_HASHSIZE]; + +static const struct tok tcp_flag_values[] = { + { TH_FIN, "F" }, + { TH_SYN, "S" }, + { TH_RST, "R" }, + { TH_PUSH, "P" }, + { TH_ACK, "." }, + { TH_URG, "U" }, + { TH_ECNECHO, "E" }, + { TH_CWR, "W" }, + { 0, NULL } +}; + +static const struct tok tcp_option_values[] = { + { TCPOPT_EOL, "eol" }, + { TCPOPT_NOP, "nop" }, + { TCPOPT_MAXSEG, "mss" }, + { TCPOPT_WSCALE, "wscale" }, + { TCPOPT_SACKOK, "sackOK" }, + { TCPOPT_SACK, "sack" }, + { TCPOPT_ECHO, "echo" }, + { TCPOPT_ECHOREPLY, "echoreply" }, + { TCPOPT_TIMESTAMP, "TS" }, + { TCPOPT_CC, "cc" }, + { TCPOPT_CCNEW, "ccnew" }, + { TCPOPT_CCECHO, "" }, + { TCPOPT_SIGNATURE, "md5" }, + { TCPOPT_SCPS, "scps" }, + { TCPOPT_UTO, "uto" }, + { TCPOPT_TCPAO, "tcp-ao" }, + { TCPOPT_MPTCP, "mptcp" }, + { TCPOPT_FASTOPEN, "tfo" }, + { TCPOPT_EXPERIMENT2, "exp" }, + { 0, NULL } +}; + +static int +tcp_cksum(netdissect_options *ndo, + register const struct ip *ip, + register const struct tcphdr *tp, + register u_int len) +{ + return nextproto4_cksum(ndo, ip, (const uint8_t *)tp, len, len, + IPPROTO_TCP); +} + +static int +tcp6_cksum(netdissect_options *ndo, + register const struct ip6_hdr *ip6, + register const struct tcphdr *tp, + register u_int len) +{ + return nextproto6_cksum(ndo, ip6, (const uint8_t *)tp, len, len, + IPPROTO_TCP); +} + +void +tcp_print(netdissect_options *ndo, + register const u_char *bp, register u_int length, + register const u_char *bp2, int fragmented) +{ + register const struct tcphdr *tp; + register const struct ip *ip; + register u_char flags; + register u_int hlen; + register char ch; + uint16_t sport, dport, win, urp; + uint32_t seq, ack, thseq, thack; + u_int utoval; + uint16_t magic; + register int rev; + register const struct ip6_hdr *ip6; + + tp = (const struct tcphdr *)bp; + ip = (const struct ip *)bp2; + if (IP_V(ip) == 6) + ip6 = (const struct ip6_hdr *)bp2; + else + ip6 = NULL; + ch = '\0'; + if (!ND_TTEST(tp->th_dport)) { + ND_PRINT((ndo, "%s > %s: [|tcp]", + ipaddr_string(ndo, &ip->ip_src), + ipaddr_string(ndo, &ip->ip_dst))); + return; + } + + sport = EXTRACT_16BITS(&tp->th_sport); + dport = EXTRACT_16BITS(&tp->th_dport); + + if (ip6) { + if (ip6->ip6_nxt == IPPROTO_TCP) { + ND_PRINT((ndo, "%s.%s > %s.%s: ", + ip6addr_string(ndo, &ip6->ip6_src), + tcpport_string(ndo, sport), + ip6addr_string(ndo, &ip6->ip6_dst), + tcpport_string(ndo, dport))); + } else { + ND_PRINT((ndo, "%s > %s: ", + tcpport_string(ndo, sport), tcpport_string(ndo, dport))); + } + } else { + if (ip->ip_p == IPPROTO_TCP) { + ND_PRINT((ndo, "%s.%s > %s.%s: ", + ipaddr_string(ndo, &ip->ip_src), + tcpport_string(ndo, sport), + ipaddr_string(ndo, &ip->ip_dst), + tcpport_string(ndo, dport))); + } else { + ND_PRINT((ndo, "%s > %s: ", + tcpport_string(ndo, sport), tcpport_string(ndo, dport))); + } + } + + ND_TCHECK(*tp); + + hlen = TH_OFF(tp) * 4; + + if (hlen < sizeof(*tp)) { + ND_PRINT((ndo, " tcp %d [bad hdr length %u - too short, < %lu]", + length - hlen, hlen, (unsigned long)sizeof(*tp))); + return; + } + + seq = EXTRACT_32BITS(&tp->th_seq); + ack = EXTRACT_32BITS(&tp->th_ack); + win = EXTRACT_16BITS(&tp->th_win); + urp = EXTRACT_16BITS(&tp->th_urp); + + if (ndo->ndo_qflag) { + ND_PRINT((ndo, "tcp %d", length - hlen)); + if (hlen > length) { + ND_PRINT((ndo, " [bad hdr length %u - too long, > %u]", + hlen, length)); + } + return; + } + + flags = tp->th_flags; + ND_PRINT((ndo, "Flags [%s]", bittok2str_nosep(tcp_flag_values, "none", flags))); + + if (!ndo->ndo_Sflag && (flags & TH_ACK)) { + /* + * Find (or record) the initial sequence numbers for + * this conversation. (we pick an arbitrary + * collating order so there's only one entry for + * both directions). + */ + rev = 0; + if (ip6) { + register struct tcp_seq_hash6 *th; + struct tcp_seq_hash6 *tcp_seq_hash; + const struct in6_addr *src, *dst; + struct tha6 tha; + + tcp_seq_hash = tcp_seq_hash6; + src = &ip6->ip6_src; + dst = &ip6->ip6_dst; + if (sport > dport) + rev = 1; + else if (sport == dport) { + if (UNALIGNED_MEMCMP(src, dst, sizeof ip6->ip6_dst) > 0) + rev = 1; + } + if (rev) { + UNALIGNED_MEMCPY(&tha.src, dst, sizeof ip6->ip6_dst); + UNALIGNED_MEMCPY(&tha.dst, src, sizeof ip6->ip6_src); + tha.port = ((u_int)dport) << 16 | sport; + } else { + UNALIGNED_MEMCPY(&tha.dst, dst, sizeof ip6->ip6_dst); + UNALIGNED_MEMCPY(&tha.src, src, sizeof ip6->ip6_src); + tha.port = ((u_int)sport) << 16 | dport; + } + + for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE]; + th->nxt; th = th->nxt) + if (memcmp((char *)&tha, (char *)&th->addr, + sizeof(th->addr)) == 0) + break; + + if (!th->nxt || (flags & TH_SYN)) { + /* didn't find it or new conversation */ + if (th->nxt == NULL) { + th->nxt = (struct tcp_seq_hash6 *) + calloc(1, sizeof(*th)); + if (th->nxt == NULL) + (*ndo->ndo_error)(ndo, + "tcp_print: calloc"); + } + th->addr = tha; + if (rev) + th->ack = seq, th->seq = ack - 1; + else + th->seq = seq, th->ack = ack - 1; + } else { + if (rev) + seq -= th->ack, ack -= th->seq; + else + seq -= th->seq, ack -= th->ack; + } + + thseq = th->seq; + thack = th->ack; + } else { + register struct tcp_seq_hash *th; + struct tcp_seq_hash *tcp_seq_hash; + struct tha tha; + + tcp_seq_hash = tcp_seq_hash4; + if (sport > dport) + rev = 1; + else if (sport == dport) { + if (UNALIGNED_MEMCMP(&ip->ip_src, &ip->ip_dst, sizeof ip->ip_dst) > 0) + rev = 1; + } + if (rev) { + UNALIGNED_MEMCPY(&tha.src, &ip->ip_dst, sizeof ip->ip_dst); + UNALIGNED_MEMCPY(&tha.dst, &ip->ip_src, sizeof ip->ip_src); + tha.port = ((u_int)dport) << 16 | sport; + } else { + UNALIGNED_MEMCPY(&tha.dst, &ip->ip_dst, sizeof ip->ip_dst); + UNALIGNED_MEMCPY(&tha.src, &ip->ip_src, sizeof ip->ip_src); + tha.port = ((u_int)sport) << 16 | dport; + } + + for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE]; + th->nxt; th = th->nxt) + if (memcmp((char *)&tha, (char *)&th->addr, + sizeof(th->addr)) == 0) + break; + + if (!th->nxt || (flags & TH_SYN)) { + /* didn't find it or new conversation */ + if (th->nxt == NULL) { + th->nxt = (struct tcp_seq_hash *) + calloc(1, sizeof(*th)); + if (th->nxt == NULL) + (*ndo->ndo_error)(ndo, + "tcp_print: calloc"); + } + th->addr = tha; + if (rev) + th->ack = seq, th->seq = ack - 1; + else + th->seq = seq, th->ack = ack - 1; + } else { + if (rev) + seq -= th->ack, ack -= th->seq; + else + seq -= th->seq, ack -= th->ack; + } + + thseq = th->seq; + thack = th->ack; + } + } else { + /*fool gcc*/ + thseq = thack = rev = 0; + } + if (hlen > length) { + ND_PRINT((ndo, " [bad hdr length %u - too long, > %u]", + hlen, length)); + return; + } + + if (ndo->ndo_vflag && !ndo->ndo_Kflag && !fragmented) { + /* Check the checksum, if possible. */ + uint16_t sum, tcp_sum; + + if (IP_V(ip) == 4) { + if (ND_TTEST2(tp->th_sport, length)) { + sum = tcp_cksum(ndo, ip, tp, length); + tcp_sum = EXTRACT_16BITS(&tp->th_sum); + + ND_PRINT((ndo, ", cksum 0x%04x", tcp_sum)); + if (sum != 0) + ND_PRINT((ndo, " (incorrect -> 0x%04x)", + in_cksum_shouldbe(tcp_sum, sum))); + else + ND_PRINT((ndo, " (correct)")); + } + } else if (IP_V(ip) == 6 && ip6->ip6_plen) { + if (ND_TTEST2(tp->th_sport, length)) { + sum = tcp6_cksum(ndo, ip6, tp, length); + tcp_sum = EXTRACT_16BITS(&tp->th_sum); + + ND_PRINT((ndo, ", cksum 0x%04x", tcp_sum)); + if (sum != 0) + ND_PRINT((ndo, " (incorrect -> 0x%04x)", + in_cksum_shouldbe(tcp_sum, sum))); + else + ND_PRINT((ndo, " (correct)")); + + } + } + } + + length -= hlen; + if (ndo->ndo_vflag > 1 || length > 0 || flags & (TH_SYN | TH_FIN | TH_RST)) { + ND_PRINT((ndo, ", seq %u", seq)); + + if (length > 0) { + ND_PRINT((ndo, ":%u", seq + length)); + } + } + + if (flags & TH_ACK) { + ND_PRINT((ndo, ", ack %u", ack)); + } + + ND_PRINT((ndo, ", win %d", win)); + + if (flags & TH_URG) + ND_PRINT((ndo, ", urg %d", urp)); + /* + * Handle any options. + */ + if (hlen > sizeof(*tp)) { + register const u_char *cp; + register u_int i, opt, datalen; + register u_int len; + + hlen -= sizeof(*tp); + cp = (const u_char *)tp + sizeof(*tp); + ND_PRINT((ndo, ", options [")); + while (hlen > 0) { + if (ch != '\0') + ND_PRINT((ndo, "%c", ch)); + ND_TCHECK(*cp); + opt = *cp++; + if (ZEROLENOPT(opt)) + len = 1; + else { + ND_TCHECK(*cp); + len = *cp++; /* total including type, len */ + if (len < 2 || len > hlen) + goto bad; + --hlen; /* account for length byte */ + } + --hlen; /* account for type byte */ + datalen = 0; + +/* Bail if "l" bytes of data are not left or were not captured */ +#define LENCHECK(l) { if ((l) > hlen) goto bad; ND_TCHECK2(*cp, l); } + + + ND_PRINT((ndo, "%s", tok2str(tcp_option_values, "unknown-%u", opt))); + + switch (opt) { + + case TCPOPT_MAXSEG: + datalen = 2; + LENCHECK(datalen); + ND_PRINT((ndo, " %u", EXTRACT_16BITS(cp))); + break; + + case TCPOPT_WSCALE: + datalen = 1; + LENCHECK(datalen); + ND_PRINT((ndo, " %u", *cp)); + break; + + case TCPOPT_SACK: + datalen = len - 2; + if (datalen % 8 != 0) { + ND_PRINT((ndo, " invalid sack")); + } else { + uint32_t s, e; + + ND_PRINT((ndo, " %d ", datalen / 8)); + for (i = 0; i < datalen; i += 8) { + LENCHECK(i + 4); + s = EXTRACT_32BITS(cp + i); + LENCHECK(i + 8); + e = EXTRACT_32BITS(cp + i + 4); + if (rev) { + s -= thseq; + e -= thseq; + } else { + s -= thack; + e -= thack; + } + ND_PRINT((ndo, "{%u:%u}", s, e)); + } + } + break; + + case TCPOPT_CC: + case TCPOPT_CCNEW: + case TCPOPT_CCECHO: + case TCPOPT_ECHO: + case TCPOPT_ECHOREPLY: + + /* + * those options share their semantics. + * fall through + */ + datalen = 4; + LENCHECK(datalen); + ND_PRINT((ndo, " %u", EXTRACT_32BITS(cp))); + break; + + case TCPOPT_TIMESTAMP: + datalen = 8; + LENCHECK(datalen); + ND_PRINT((ndo, " val %u ecr %u", + EXTRACT_32BITS(cp), + EXTRACT_32BITS(cp + 4))); + break; + + case TCPOPT_SIGNATURE: + datalen = TCP_SIGLEN; + LENCHECK(datalen); + ND_PRINT((ndo, " ")); +#ifdef HAVE_LIBCRYPTO + switch (tcp_verify_signature(ndo, ip, tp, + bp + TH_OFF(tp) * 4, length, cp)) { + + case SIGNATURE_VALID: + ND_PRINT((ndo, "valid")); + break; + + case SIGNATURE_INVALID: + ND_PRINT((ndo, "invalid")); + break; + + case CANT_CHECK_SIGNATURE: + ND_PRINT((ndo, "can't check - ")); + for (i = 0; i < TCP_SIGLEN; ++i) + ND_PRINT((ndo, "%02x", cp[i])); + break; + } +#else + for (i = 0; i < TCP_SIGLEN; ++i) + ND_PRINT((ndo, "%02x", cp[i])); +#endif + break; + + case TCPOPT_SCPS: + datalen = 2; + LENCHECK(datalen); + ND_PRINT((ndo, " cap %02x id %u", cp[0], cp[1])); + break; + + case TCPOPT_TCPAO: + datalen = len - 2; + /* RFC 5925 Section 2.2: + * "The Length value MUST be greater than or equal to 4." + * (This includes the Kind and Length fields already processed + * at this point.) + */ + if (datalen < 2) { + ND_PRINT((ndo, " invalid")); + } else { + LENCHECK(1); + ND_PRINT((ndo, " keyid %u", cp[0])); + LENCHECK(2); + ND_PRINT((ndo, " rnextkeyid %u", cp[1])); + if (datalen > 2) { + ND_PRINT((ndo, " mac 0x")); + for (i = 2; i < datalen; i++) { + LENCHECK(i + 1); + ND_PRINT((ndo, "%02x", cp[i])); + } + } + } + break; + + case TCPOPT_EOL: + case TCPOPT_NOP: + case TCPOPT_SACKOK: + /* + * Nothing interesting. + * fall through + */ + break; + + case TCPOPT_UTO: + datalen = 2; + LENCHECK(datalen); + utoval = EXTRACT_16BITS(cp); + ND_PRINT((ndo, " 0x%x", utoval)); + if (utoval & 0x0001) + utoval = (utoval >> 1) * 60; + else + utoval >>= 1; + ND_PRINT((ndo, " %u", utoval)); + break; + + case TCPOPT_MPTCP: + datalen = len - 2; + LENCHECK(datalen); + if (!mptcp_print(ndo, cp-2, len, flags)) + goto bad; + break; + + case TCPOPT_FASTOPEN: + datalen = len - 2; + LENCHECK(datalen); + ND_PRINT((ndo, " ")); + print_tcp_fastopen_option(ndo, cp, datalen, FALSE); + break; + + case TCPOPT_EXPERIMENT2: + datalen = len - 2; + LENCHECK(datalen); + if (datalen < 2) + goto bad; + /* RFC6994 */ + magic = EXTRACT_16BITS(cp); + ND_PRINT((ndo, "-")); + + switch(magic) { + + case 0xf989: /* TCP Fast Open RFC 7413 */ + print_tcp_fastopen_option(ndo, cp + 2, datalen - 2, TRUE); + break; + + default: + /* Unknown magic number */ + ND_PRINT((ndo, "%04x", magic)); + break; + } + break; + + default: + datalen = len - 2; + if (datalen) + ND_PRINT((ndo, " 0x")); + for (i = 0; i < datalen; ++i) { + LENCHECK(i + 1); + ND_PRINT((ndo, "%02x", cp[i])); + } + break; + } + + /* Account for data printed */ + cp += datalen; + hlen -= datalen; + + /* Check specification against observed length */ + ++datalen; /* option octet */ + if (!ZEROLENOPT(opt)) + ++datalen; /* size octet */ + if (datalen != len) + ND_PRINT((ndo, "[len %d]", len)); + ch = ','; + if (opt == TCPOPT_EOL) + break; + } + ND_PRINT((ndo, "]")); + } + + /* + * Print length field before crawling down the stack. + */ + ND_PRINT((ndo, ", length %u", length)); + + if (length <= 0) + return; + + /* + * Decode payload if necessary. + */ + bp += TH_OFF(tp) * 4; + if ((flags & TH_RST) && ndo->ndo_vflag) { + print_tcp_rst_data(ndo, bp, length); + return; + } + + if (ndo->ndo_packettype) { + switch (ndo->ndo_packettype) { + case PT_ZMTP1: + zmtp1_print(ndo, bp, length); + break; + case PT_RESP: + resp_print(ndo, bp, length); + break; + } + return; + } + + if (IS_SRC_OR_DST_PORT(TELNET_PORT)) { + telnet_print(ndo, bp, length); + } else if (IS_SRC_OR_DST_PORT(SMTP_PORT)) { + ND_PRINT((ndo, ": ")); + smtp_print(ndo, bp, length); + } else if (IS_SRC_OR_DST_PORT(BGP_PORT)) + bgp_print(ndo, bp, length); + else if (IS_SRC_OR_DST_PORT(PPTP_PORT)) + pptp_print(ndo, bp); + else if (IS_SRC_OR_DST_PORT(REDIS_PORT)) + resp_print(ndo, bp, length); +#ifdef ENABLE_SMB + else if (IS_SRC_OR_DST_PORT(NETBIOS_SSN_PORT)) + nbt_tcp_print(ndo, bp, length); + else if (IS_SRC_OR_DST_PORT(SMB_PORT)) + smb_tcp_print(ndo, bp, length); +#endif + else if (IS_SRC_OR_DST_PORT(BEEP_PORT)) + beep_print(ndo, bp, length); + else if (IS_SRC_OR_DST_PORT(OPENFLOW_PORT_OLD) || IS_SRC_OR_DST_PORT(OPENFLOW_PORT_IANA)) + openflow_print(ndo, bp, length); + else if (IS_SRC_OR_DST_PORT(FTP_PORT)) { + ND_PRINT((ndo, ": ")); + ftp_print(ndo, bp, length); + } else if (IS_SRC_OR_DST_PORT(HTTP_PORT) || IS_SRC_OR_DST_PORT(HTTP_PORT_ALT)) { + ND_PRINT((ndo, ": ")); + http_print(ndo, bp, length); + } else if (IS_SRC_OR_DST_PORT(RTSP_PORT) || IS_SRC_OR_DST_PORT(RTSP_PORT_ALT)) { + ND_PRINT((ndo, ": ")); + rtsp_print(ndo, bp, length); + } else if (length > 2 && + (IS_SRC_OR_DST_PORT(NAMESERVER_PORT))) { + /* domain_print() assumes it does not have to prepend a space before its + * own output to separate it from the output of the calling function. This + * works well with udp_print(), but requires a small prop here. + */ + ND_PRINT((ndo, " ")); + + /* + * TCP DNS query has 2byte length at the head. + * XXX packet could be unaligned, it can go strange + */ + ns_print(ndo, bp + 2, length - 2, 0); + } else if (IS_SRC_OR_DST_PORT(MSDP_PORT)) { + msdp_print(ndo, bp, length); + } else if (IS_SRC_OR_DST_PORT(RPKI_RTR_PORT)) { + rpki_rtr_print(ndo, bp, length); + } + else if (length > 0 && (IS_SRC_OR_DST_PORT(LDP_PORT))) { + ldp_print(ndo, bp, length); + } + else if ((IS_SRC_OR_DST_PORT(NFS_PORT)) && + length >= 4 && ND_TTEST2(*bp, 4)) { + /* + * If data present, header length valid, and NFS port used, + * assume NFS. + * Pass offset of data plus 4 bytes for RPC TCP msg length + * to NFS print routines. + */ + uint32_t fraglen; + register const struct sunrpc_msg *rp; + enum sunrpc_msg_type direction; + + fraglen = EXTRACT_32BITS(bp) & 0x7FFFFFFF; + if (fraglen > (length) - 4) + fraglen = (length) - 4; + rp = (const struct sunrpc_msg *)(bp + 4); + if (ND_TTEST(rp->rm_direction)) { + direction = (enum sunrpc_msg_type)EXTRACT_32BITS(&rp->rm_direction); + if (dport == NFS_PORT && direction == SUNRPC_CALL) { + ND_PRINT((ndo, ": NFS request xid %u ", EXTRACT_32BITS(&rp->rm_xid))); + nfsreq_print_noaddr(ndo, (const u_char *)rp, fraglen, (const u_char *)ip); + return; + } + if (sport == NFS_PORT && direction == SUNRPC_REPLY) { + ND_PRINT((ndo, ": NFS reply xid %u ", EXTRACT_32BITS(&rp->rm_xid))); + nfsreply_print_noaddr(ndo, (const u_char *)rp, fraglen, (const u_char *)ip); + return; + } + } + } + + return; + bad: + ND_PRINT((ndo, "[bad opt]")); + if (ch != '\0') + ND_PRINT((ndo, ">")); + return; + trunc: + ND_PRINT((ndo, "[|tcp]")); + if (ch != '\0') + ND_PRINT((ndo, ">")); +} + +/* + * RFC1122 says the following on data in RST segments: + * + * 4.2.2.12 RST Segment: RFC-793 Section 3.4 + * + * A TCP SHOULD allow a received RST segment to include data. + * + * DISCUSSION + * It has been suggested that a RST segment could contain + * ASCII text that encoded and explained the cause of the + * RST. No standard has yet been established for such + * data. + * + */ + +static void +print_tcp_rst_data(netdissect_options *ndo, + register const u_char *sp, u_int length) +{ + int c; + + ND_PRINT((ndo, ND_TTEST2(*sp, length) ? " [RST" : " [!RST")); + if (length > MAX_RST_DATA_LEN) { + length = MAX_RST_DATA_LEN; /* can use -X for longer */ + ND_PRINT((ndo, "+")); /* indicate we truncate */ + } + ND_PRINT((ndo, " ")); + while (length-- && sp < ndo->ndo_snapend) { + c = *sp++; + safeputchar(ndo, c); + } + ND_PRINT((ndo, "]")); +} + +static void +print_tcp_fastopen_option(netdissect_options *ndo, register const u_char *cp, + u_int datalen, int exp) +{ + u_int i; + + if (exp) + ND_PRINT((ndo, "tfo")); + + if (datalen == 0) { + /* Fast Open Cookie Request */ + ND_PRINT((ndo, " cookiereq")); + } else { + /* Fast Open Cookie */ + if (datalen % 2 != 0 || datalen < 4 || datalen > 16) { + ND_PRINT((ndo, " invalid")); + } else { + ND_PRINT((ndo, " cookie ")); + for (i = 0; i < datalen; ++i) + ND_PRINT((ndo, "%02x", cp[i])); + } + } +} + +#ifdef HAVE_LIBCRYPTO +USES_APPLE_DEPRECATED_API +static int +tcp_verify_signature(netdissect_options *ndo, + const struct ip *ip, const struct tcphdr *tp, + const u_char *data, int length, const u_char *rcvsig) +{ + struct tcphdr tp1; + u_char sig[TCP_SIGLEN]; + char zero_proto = 0; + MD5_CTX ctx; + uint16_t savecsum, tlen; + const struct ip6_hdr *ip6; + uint32_t len32; + uint8_t nxt; + + if (data + length > ndo->ndo_snapend) { + ND_PRINT((ndo, "snaplen too short, ")); + return (CANT_CHECK_SIGNATURE); + } + + tp1 = *tp; + + if (ndo->ndo_sigsecret == NULL) { + ND_PRINT((ndo, "shared secret not supplied with -M, ")); + return (CANT_CHECK_SIGNATURE); + } + + MD5_Init(&ctx); + /* + * Step 1: Update MD5 hash with IP pseudo-header. + */ + if (IP_V(ip) == 4) { + MD5_Update(&ctx, (const char *)&ip->ip_src, sizeof(ip->ip_src)); + MD5_Update(&ctx, (const char *)&ip->ip_dst, sizeof(ip->ip_dst)); + MD5_Update(&ctx, (const char *)&zero_proto, sizeof(zero_proto)); + MD5_Update(&ctx, (const char *)&ip->ip_p, sizeof(ip->ip_p)); + tlen = EXTRACT_16BITS(&ip->ip_len) - IP_HL(ip) * 4; + tlen = htons(tlen); + MD5_Update(&ctx, (const char *)&tlen, sizeof(tlen)); + } else if (IP_V(ip) == 6) { + ip6 = (const struct ip6_hdr *)ip; + MD5_Update(&ctx, (const char *)&ip6->ip6_src, sizeof(ip6->ip6_src)); + MD5_Update(&ctx, (const char *)&ip6->ip6_dst, sizeof(ip6->ip6_dst)); + len32 = htonl(EXTRACT_16BITS(&ip6->ip6_plen)); + MD5_Update(&ctx, (const char *)&len32, sizeof(len32)); + nxt = 0; + MD5_Update(&ctx, (const char *)&nxt, sizeof(nxt)); + MD5_Update(&ctx, (const char *)&nxt, sizeof(nxt)); + MD5_Update(&ctx, (const char *)&nxt, sizeof(nxt)); + nxt = IPPROTO_TCP; + MD5_Update(&ctx, (const char *)&nxt, sizeof(nxt)); + } else { + ND_PRINT((ndo, "IP version not 4 or 6, ")); + return (CANT_CHECK_SIGNATURE); + } + + /* + * Step 2: Update MD5 hash with TCP header, excluding options. + * The TCP checksum must be set to zero. + */ + savecsum = tp1.th_sum; + tp1.th_sum = 0; + MD5_Update(&ctx, (const char *)&tp1, sizeof(struct tcphdr)); + tp1.th_sum = savecsum; + /* + * Step 3: Update MD5 hash with TCP segment data, if present. + */ + if (length > 0) + MD5_Update(&ctx, data, length); + /* + * Step 4: Update MD5 hash with shared secret. + */ + MD5_Update(&ctx, ndo->ndo_sigsecret, strlen(ndo->ndo_sigsecret)); + MD5_Final(sig, &ctx); + + if (memcmp(rcvsig, sig, TCP_SIGLEN) == 0) + return (SIGNATURE_VALID); + else + return (SIGNATURE_INVALID); +} +USES_APPLE_RST +#endif /* HAVE_LIBCRYPTO */ + +/* + * Local Variables: + * c-style: whitesmith + * c-basic-offset: 8 + * End: + */ |