]> The Tcpdump Group git mirrors - tcpdump/blobdiff - print-tcp.c
Use the passed in length instead of the IP header's length in the
[tcpdump] / print-tcp.c
index 1561cdc3a01edfa32af1d0059382bf2aa15a4f7b..54ae3d5571c6d7dff716625f0188baab98d009a5 100644 (file)
@@ -21,7 +21,7 @@
 
 #ifndef lint
 static const char rcsid[] =
-    "@(#) $Header: /tcpdump/master/tcpdump/print-tcp.c,v 1.62 1999-12-22 06:27:23 itojun Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/tcpdump/print-tcp.c,v 1.88 2001-08-20 17:53:53 fenner Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -31,57 +31,34 @@ static const char rcsid[] =
 #include <sys/param.h>
 #include <sys/time.h>
 
+#include <rpc/rpc.h>
+
 #include <netinet/in.h>
-#include <netinet/in_systm.h>
-#include <netinet/ip.h>
-#include <netinet/ip_var.h>
-#include <netinet/tcp.h>
 
-#ifdef HAVE_MEMORY_H
-#include <memory.h>
-#endif
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <ctype.h>
 #include <unistd.h>
 
-#ifdef INET6
-#include <netinet/ip6.h>
-#endif
-
 #include "interface.h"
 #include "addrtoname.h"
 #include "extract.h"
 
-/* Compatibility */
-#ifndef TCPOPT_WSCALE
-#define        TCPOPT_WSCALE           3       /* window scale factor (rfc1072) */
-#endif
-#ifndef TCPOPT_SACKOK
-#define        TCPOPT_SACKOK           4       /* selective ack ok (rfc1072) */
-#endif
-#ifndef TCPOPT_SACK
-#define        TCPOPT_SACK             5       /* selective ack (rfc1072) */
-#endif
-#ifndef TCPOPT_ECHO
-#define        TCPOPT_ECHO             6       /* echo (rfc1072) */
-#endif
-#ifndef TCPOPT_ECHOREPLY
-#define        TCPOPT_ECHOREPLY        7       /* echo (rfc1072) */
-#endif
-#ifndef TCPOPT_TIMESTAMP
-#define TCPOPT_TIMESTAMP       8       /* timestamps (rfc1323) */
-#endif
-#ifndef TCPOPT_CC
-#define TCPOPT_CC              11      /* T/TCP CC options (rfc1644) */
-#endif
-#ifndef TCPOPT_CCNEW
-#define TCPOPT_CCNEW           12      /* T/TCP CC options (rfc1644) */
-#endif
-#ifndef TCPOPT_CCECHO
-#define TCPOPT_CCECHO          13      /* T/TCP CC options (rfc1644) */
+#include "tcp.h"
+
+#include "ip.h"
+#ifdef INET6
+#include "ip6.h"
 #endif
 
+#include "nameser.h"
+
+static void print_tcp_rst_data(register const u_char *sp, u_int length);
+
+#define MAX_RST_DATA_LEN       30
+
+
 struct tha {
 #ifndef INET6
        struct in_addr src;
@@ -108,21 +85,107 @@ struct tcp_seq_hash {
 static struct tcp_seq_hash tcp_seq_hash[TSEQ_HASHSIZE];
 
 
+#ifndef TELNET_PORT
+#define TELNET_PORT    23
+#endif
 #ifndef BGP_PORT
 #define BGP_PORT       179
 #endif
 #define NETBIOS_SSN_PORT 139
+#ifndef PPTP_PORT
+#define PPTP_PORT      1723
+#endif
+#define BXXP_PORT        10288
+#ifndef NFS_PORT
+#define NFS_PORT       2049
+#endif
+
+static int tcp_cksum(register const struct ip *ip,
+                    register const struct tcphdr *tp,
+                    register int len)
+{
+       union phu {
+               struct phdr {
+                       u_int32_t src;
+                       u_int32_t dst;
+                       u_char mbz;
+                       u_char proto;
+                       u_int16_t len;
+               } ph;
+               u_int16_t pa[6];
+       } phu;
+       const u_int16_t *sp;
+
+       /* pseudo-header.. */
+       phu.ph.len = htons(len);        /* XXX */
+       phu.ph.mbz = 0;
+       phu.ph.proto = IPPROTO_TCP;
+       memcpy(&phu.ph.src, &ip->ip_src.s_addr, sizeof(u_int32_t));
+       memcpy(&phu.ph.dst, &ip->ip_dst.s_addr, sizeof(u_int32_t));
+
+       sp = &phu.pa[0];
+       return in_cksum((u_short *)tp, len,
+                       sp[0]+sp[1]+sp[2]+sp[3]+sp[4]+sp[5]);
+}
+
+#ifdef INET6
+static int tcp6_cksum(const struct ip6_hdr *ip6, const struct tcphdr *tp,
+       int len)
+{
+       int i, tlen;
+       register const u_int16_t *sp;
+       u_int32_t sum;
+       union {
+               struct {
+                       struct in6_addr ph_src;
+                       struct in6_addr ph_dst;
+                       u_int32_t       ph_len;
+                       u_int8_t        ph_zero[3];
+                       u_int8_t        ph_nxt;
+               } ph;
+               u_int16_t pa[20];
+       } phu;
+
+       tlen = ntohs(ip6->ip6_plen) + sizeof(struct ip6_hdr) -
+           ((const char *)tp - (const char*)ip6);
+
+       /* pseudo-header */
+       memset(&phu, 0, sizeof(phu));
+       phu.ph.ph_src = ip6->ip6_src;
+       phu.ph.ph_dst = ip6->ip6_dst;
+       phu.ph.ph_len = htonl(tlen);
+       phu.ph.ph_nxt = IPPROTO_TCP;
+
+       sum = 0;
+       for (i = 0; i < sizeof(phu.pa) / sizeof(phu.pa[0]); i++)
+               sum += phu.pa[i];
+
+       sp = (const u_int16_t *)tp;
+
+       for (i = 0; i < (tlen & ~1); i += 2)
+               sum += *sp++;
+
+       if (tlen & 1)
+               sum += htons((*(const u_int8_t *)sp) << 8);
+
+       while (sum > 0xffff)
+               sum = (sum & 0xffff) + (sum >> 16);
+       sum = ~sum & 0xffff;
+
+       return (sum);
+}
+#endif
 
 void
 tcp_print(register const u_char *bp, register u_int length,
-         register const u_char *bp2)
+         register const u_char *bp2, int fragmented)
 {
        register const struct tcphdr *tp;
        register const struct ip *ip;
        register u_char flags;
        register int hlen;
        register char ch;
-       u_short sport, dport, win, urp;
+       u_int16_t sport, dport, win, urp;
        u_int32_t seq, ack, thseq, thack;
        int threv;
 #ifdef INET6
@@ -132,7 +195,7 @@ tcp_print(register const u_char *bp, register u_int length,
        tp = (struct tcphdr *)bp;
        ip = (struct ip *)bp2;
 #ifdef INET6
-       if (ip->ip_v == 6)
+       if (IP_V(ip) == 6)
                ip6 = (struct ip6_hdr *)bp2;
        else
                ip6 = NULL;
@@ -148,6 +211,28 @@ tcp_print(register const u_char *bp, register u_int length,
        sport = ntohs(tp->th_sport);
        dport = ntohs(tp->th_dport);
 
+
+       hlen = TH_OFF(tp) * 4;
+
+       /*
+        * If data present and NFS port used, assume NFS.
+        * Pass offset of data plus 4 bytes for RPC TCP msg length
+        * to NFS print routines.
+        */
+       if (!qflag) {
+               if ((u_char *)tp + 4 + sizeof(struct rpc_msg) <= snapend &&
+                   dport == NFS_PORT) {
+                       nfsreq_print((u_char *)tp + hlen + 4, length - hlen,
+                                    (u_char *)ip);
+                       return;
+               } else if ((u_char *)tp + 4 + sizeof(struct rpc_msg)
+                          <= snapend &&
+                          sport == NFS_PORT) {
+                       nfsreply_print((u_char *)tp + hlen + 4, length - hlen,
+                                      (u_char *)ip);
+                       return;
+               }
+       }
 #ifdef INET6
        if (ip6) {
                if (ip6->ip6_nxt == IPPROTO_TCP) {
@@ -177,21 +262,17 @@ tcp_print(register const u_char *bp, register u_int length,
 
        TCHECK(*tp);
 
-       seq = ntohl(tp->th_seq);
-       ack = ntohl(tp->th_ack);
+       seq = (u_int32_t)ntohl(tp->th_seq);
+       ack = (u_int32_t)ntohl(tp->th_ack);
        win = ntohs(tp->th_win);
        urp = ntohs(tp->th_urp);
 
        if (qflag) {
-               (void)printf("tcp %d", length - tp->th_off * 4);
+               (void)printf("tcp %d", length - TH_OFF(tp) * 4);
                return;
        }
-#ifdef TH_ECN
-       if ((flags = tp->th_flags) & (TH_SYN|TH_FIN|TH_RST|TH_PUSH|TH_ECN))
-#else
-       if ((flags = tp->th_flags) & (TH_SYN|TH_FIN|TH_RST|TH_PUSH))
-#endif
-       {
+       if ((flags = tp->th_flags) & (TH_SYN|TH_FIN|TH_RST|TH_PUSH|
+                                     TH_ECNECHO|TH_CWR)) {
                if (flags & TH_SYN)
                        putchar('S');
                if (flags & TH_FIN)
@@ -200,22 +281,13 @@ tcp_print(register const u_char *bp, register u_int length,
                        putchar('R');
                if (flags & TH_PUSH)
                        putchar('P');
-#ifdef TH_ECN
-               if (flags & TH_ECN)
-                       putchar('C');
-#endif
+               if (flags & TH_CWR)
+                       putchar('W');   /* congestion _W_indow reduced (ECN) */
+               if (flags & TH_ECNECHO)
+                       putchar('E');   /* ecn _E_cho sent (ECN) */
        } else
                putchar('.');
 
-       if (flags&0xc0) {
-               printf(" [");
-               if (flags&0x40)
-                       printf("ECN-Echo");
-               if (flags&0x80)
-                       printf("%sCWR", (flags&0x40) ? "," : "");
-               printf("]");
-       }
-
        if (!Sflag && (flags & TH_ACK)) {
                register struct tcp_seq_hash *th;
                register int rev;
@@ -227,21 +299,21 @@ tcp_print(register const u_char *bp, register u_int length,
                 * both directions).
                 */
 #ifdef INET6
-               bzero(&tha, sizeof(tha));
+               memset(&tha, 0, sizeof(tha));
                rev = 0;
                if (ip6) {
-                       if (sport > dport) {
+                       if (sport > dport)
                                rev = 1;
-                       } else if (sport == dport) {
-                           int i;
-
-                           for (i = 0; i < 4; i++) {
-                               if (((u_int32_t *)(&ip6->ip6_src))[i] >
-                                   ((u_int32_t *)(&ip6->ip6_dst))[i]) {
-                                       rev = 1;
-                                       break;
+                       else if (sport == dport) {
+                               int i;
+
+                               for (i = 0; i < 4; i++) {
+                                       if (((u_int32_t *)(&ip6->ip6_src))[i] >
+                                           ((u_int32_t *)(&ip6->ip6_dst))[i]) {
+                                               rev = 1;
+                                               break;
+                                       }
                                }
-                           }
                        }
                        if (rev) {
                                tha.src = ip6->ip6_dst;
@@ -289,7 +361,7 @@ tcp_print(register const u_char *bp, register u_int length,
                                  sizeof(th->addr)))
                                break;
 
-               if (!th->nxt || flags & TH_SYN) {
+               if (!th->nxt || (flags & TH_SYN)) {
                        /* didn't find it or new conversation */
                        if (th->nxt == NULL) {
                                th->nxt = (struct tcp_seq_hash *)
@@ -303,21 +375,46 @@ tcp_print(register const u_char *bp, register u_int length,
                        else
                                th->seq = seq, th->ack = ack - 1;
                } else {
-         
-                       thseq = th->seq;
-                       thack = th->ack;
-
                        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 = threv = 0;
        }
-       hlen = tp->th_off * 4;
        if (hlen > length) {
                (void)printf(" [bad hdr length]");
                return;
        }
+
+       if (IP_V(ip) == 4 && vflag && !fragmented) {
+               int sum;
+               if (TTEST2(tp->th_sport, length)) {
+                       sum = tcp_cksum(ip, tp, length);
+                       if (sum != 0)
+                               (void)printf(" [bad tcp cksum %x!]", sum);
+                       else
+                               (void)printf(" [tcp sum ok]");
+               }
+       }
+#ifdef INET6
+       if (IP_V(ip) == 6 && ip6->ip6_plen && vflag && !fragmented) {
+               int sum;
+               if (TTEST2(tp->th_sport, length)) {
+                       sum = tcp6_cksum(ip6, tp, length);
+                       if (sum != 0)
+                               (void)printf(" [bad tcp cksum %x!]", sum);
+                       else
+                               (void)printf(" [tcp sum ok]");
+               }
+       }
+#endif
+
        length -= hlen;
        if (vflag > 1 || length > 0 || flags & (TH_SYN | TH_FIN | TH_RST))
                (void)printf(" %u:%u(%d)", seq, seq + length, length);
@@ -490,11 +587,28 @@ tcp_print(register const u_char *bp, register u_int length,
        /*
         * Decode payload if necessary.
         */
-       bp += (tp->th_off * 4);
-       if (sport == BGP_PORT || dport == BGP_PORT)
-               bgp_print(bp, length);
-       if (sport == NETBIOS_SSN_PORT || dport == NETBIOS_SSN_PORT)
-               nbt_tcp_print(bp, length);
+       bp += TH_OFF(tp) * 4;
+       if (flags & TH_RST) {
+               if (vflag)
+                       print_tcp_rst_data(bp, length);
+       } else {
+               if (sport == TELNET_PORT || dport == TELNET_PORT) {
+                       if (!qflag && vflag)
+                               telnet_print(bp, length);
+               } else if (sport == BGP_PORT || dport == BGP_PORT)
+                       bgp_print(bp, length);
+               else if (sport == PPTP_PORT || dport == PPTP_PORT)
+                       pptp_print(bp, length);
+               else if (sport == NETBIOS_SSN_PORT || dport == NETBIOS_SSN_PORT)
+                       nbt_tcp_print(bp, length);
+               else if (sport == BXXP_PORT || dport == BXXP_PORT)
+                       bxxp_print(bp, length);
+               else if (length > 2 &&
+                   (sport == NAMESERVER_PORT || dport == NAMESERVER_PORT)) {
+                       /* TCP DNS query has 2byte length at the head */
+                       ns_print(bp + 2, length - 2);
+               }
+       }
        return;
 bad:
        fputs("[bad opt]", stdout);
@@ -507,3 +621,38 @@ trunc:
                putchar('>');
 }
 
+/*
+ * 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(register const u_char *sp, u_int length)
+{
+       int c;
+
+       if (TTEST2(*sp, length))
+               printf(" [RST");
+       else
+               printf(" [!RST");
+       if (length > MAX_RST_DATA_LEN) {
+               length = MAX_RST_DATA_LEN;      /* can use -X for longer */
+               putchar('+');                   /* indicate we truncate */
+       }
+       putchar(' ');
+       while (length-- && sp <= snapend) {
+               c = *sp++;
+               safeputchar(c);
+       }
+       putchar(']');
+}