#ifndef lint
static const char rcsid[] =
- "@(#) $Header: /tcpdump/master/tcpdump/print-tcp.c,v 1.66 2000-06-01 01:09:32 assar Exp $ (LBL)";
+ "@(#) $Header: /tcpdump/master/tcpdump/print-tcp.c,v 1.74 2000-09-23 08:54:41 guy Exp $ (LBL)";
#endif
#ifdef HAVE_CONFIG_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 "addrtoname.h"
#include "extract.h"
+#include "tcp.h"
+
+#include "ip.h"
+
+static void print_tcp_rst_data(register const u_char *sp, u_int length);
+
+#define MAX_RST_DATA_LEN 30
+
/* Compatibility */
#ifndef TCPOPT_WSCALE
#define TCPOPT_WSCALE 3 /* window scale factor (rfc1072) */
#define NFS_PORT 2049
#endif
+static int tcp_cksum(register const struct ip *ip,
+ register const struct tcphdr *tp,
+ register int len)
+{
+ int i, tlen;
+ 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;
+ register const u_int16_t *sp;
+ u_int32_t sum;
+ tlen = ntohs(ip->ip_len) - ((const char *)tp-(const char*)ip);
+
+ /* pseudo-header.. */
+ phu.ph.len = htons(tlen);
+ 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];
+ sum = sp[0]+sp[1]+sp[2]+sp[3]+sp[4]+sp[5];
+
+ sp = (const u_int16_t *)tp;
+
+ for (i=0; i<(tlen&~1); i+= 2)
+ sum += *sp++;
+
+ if (tlen & 1) {
+ sum += htons( (*(const char *)sp) << 8);
+ }
+
+ while (sum > 0xffff)
+ sum = (sum & 0xffff) + (sum >> 16);
+ sum = ~sum & 0xffff;
+
+ return (sum);
+}
+
+#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 char *)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)
* both directions).
*/
#ifdef INET6
- bzero(&tha, sizeof(tha));
+ memset(&tha, 0, sizeof(tha));
rev = 0;
if (ip6) {
if (sport > dport) {
(void)printf(" [bad hdr length]");
return;
}
+
+ if (ip->ip_v == 4 && vflag) {
+ 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->ip_v == 6 && ip6->ip6_plen && vflag) {
+ 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);
* Decode payload if necessary.
*/
bp += (tp->th_off * 4);
- if (!qflag && vflag && length > 0
- && (sport == TELNET_PORT || dport == TELNET_PORT))
- telnet_print(bp, length);
- else if (sport == BGP_PORT || dport == BGP_PORT)
- bgp_print(bp, length);
- else if (sport == NETBIOS_SSN_PORT || dport == NETBIOS_SSN_PORT)
- nbt_tcp_print(bp, length);
+ 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 == NETBIOS_SSN_PORT || dport == NETBIOS_SSN_PORT)
+ nbt_tcp_print(bp, length);
+ }
return;
bad:
fputs("[bad opt]", stdout);
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++;
+ if (isprint(c))
+ putchar(c);
+ else
+ putchar('.');
+ }
+ putchar(']');
+}
projects / tcpdump / blobdiff