don't pass on src & dst MAC adresses to the isoclns decoder as MAC adresses

[tcpdump] / print-ip.c

diff --git a/print-ip.c b/print-ip.c
index 62c70342fe606607b584be85f3099fc4db3a2d06..f3471c5057854358336b4e7940bda57605dd6b6d 100644 (file)
--- a/print-ip.c
+++ b/print-ip.c
@@ -21,24 +21,18 @@
 
 #ifndef lint
 static const char rcsid[] =
 
 #ifndef lint
 static const char rcsid[] =

-    "@(#) $Header: /tcpdump/master/tcpdump/print-ip.c,v 1.101 2001-10-27 07:42:46 guy Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/tcpdump/print-ip.c,v 1.125 2003-05-21 08:39:57 hannes Exp $ (LBL)";

 #endif
 
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 
 #endif
 
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 

-#include <sys/param.h>
-#include <sys/time.h>
-#include <sys/socket.h>
+#include <tcpdump-stdinc.h>

 
 

-#include <netinet/in.h>
-
-#include <netdb.h>

 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

-#include <unistd.h>

 
 #include "addrtoname.h"
 #include "interface.h"
 
 #include "addrtoname.h"
 #include "interface.h"


@@ -76,13 +70,59 @@ ip_printroute(const char *type, register const u_char *cp, u_int length)
        printf("%s}", ptr == len? "#" : "");
 }
 
        printf("%s}", ptr == len? "#" : "");
 }
 

+/*
+ * If source-routing is present, return the final destination.
+ * Otherwise, return IP destination.
+ *
+ * This is used for UDP and TCP pseudo-header in the checksum
+ * calculation.
+ */
+u_int32_t
+ip_finddst(const struct ip *ip)
+{
+       int length;
+       int len;
+       const u_char *cp;
+       u_int32_t retval;
+
+       cp = (const u_char *)(ip + 1);
+       length = (IP_HL(ip) << 2) - sizeof(struct ip);
+
+       for (; length > 0; cp += len, length -= len) {
+               int tt = *cp;
+
+               if (tt == IPOPT_NOP || tt == IPOPT_EOL)
+                       len = 1;
+               else {
+                       if (&cp[1] >= snapend) {
+                               return 0;
+                       }
+                       len = cp[1];
+               }
+               if (len <= 0) {
+                       return 0;
+               }
+               if (&cp[1] >= snapend || cp + len > snapend) {
+                       return 0;
+               }
+               switch (tt) {
+
+               case IPOPT_SSRR:
+               case IPOPT_LSRR:
+                       memcpy(&retval, cp + len - 4, 4);
+                       return retval;
+               }
+       }
+       return ip->ip_dst.s_addr;
+}
+

 static void
 ip_printts(register const u_char *cp, u_int length)
 {
        register u_int ptr = cp[2] - 1;
        register u_int len = 0;
        int hoplen;
 static void
 ip_printts(register const u_char *cp, u_int length)
 {
        register u_int ptr = cp[2] - 1;
        register u_int len = 0;
        int hoplen;

-       char *type;
+       const char *type;

 
        printf(" TS{");
        hoplen = ((cp[3]&0xF) != IPOPT_TS_TSONLY) ? 8 : 4;
 
        printf(" TS{");
        hoplen = ((cp[3]&0xF) != IPOPT_TS_TSONLY) ? 8 : 4;


@@ -109,7 +149,7 @@ ip_printts(register const u_char *cp, u_int length)
        case 3:                 /* IPOPT_TS_PRESPEC */
                printf("PRESPEC");
                break;
        case 3:                 /* IPOPT_TS_PRESPEC */
                printf("PRESPEC");
                break;

-       default:        
+       default:

                printf("[bad ts type %d]", cp[3]&0xF);
                goto done;
        }
                printf("[bad ts type %d]", cp[3]&0xF);
                goto done;
        }


@@ -225,12 +265,12 @@ in_cksum(const u_short *addr, register u_int len, int csum)
        u_short answer;
        int sum = csum;
 
        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.
         *  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;
        while (nleft > 1)  {
                sum += *w++;
                nleft -= 2;


@@ -247,6 +287,73 @@ in_cksum(const u_short *addr, register u_int len, int csum)
        return (answer);
 }
 
        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[] = {
+        { IP_MF,        "+" },
+        { IP_DF,        "DF" },
+       { IP_RES,       "rsvd" }, /* The RFC3514 evil ;-) bit */
+        { 0,            NULL }
+};
+

 /*
  * print an IP datagram.
  */
 /*
  * print an IP datagram.
  */


@@ -259,34 +366,12 @@ ip_print(register const u_char *bp, register u_int length)
        u_char nh;
        int advance;
        struct protoent *proto;
        u_char nh;
        int advance;
        struct protoent *proto;

+       u_int16_t sum, ip_sum;
+       const char *sep = "";
+
+       printf("IP%s ", (((*bp >> 4) & 0xf) == 4) ? "" : "%u", (*bp >> 4) & 0xf); /* print version if != 4 */

 
        ip = (const struct ip *)bp;
 
        ip = (const struct ip *)bp;

-#ifdef LBL_ALIGN
-       /*
-        * If the IP header is not aligned, copy into abuf.
-        * This will never happen with BPF.  It does happen raw packet
-        * dumps from -r.
-        */
-       if ((long)ip & 3) {
-               static u_char *abuf = NULL;
-               static int didwarn = 0;
-
-               if (abuf == NULL) {
-                       abuf = (u_char *)malloc(snaplen);
-                       if (abuf == NULL)
-                               error("ip_print: malloc");
-               }
-               memcpy((char *)abuf, (char *)ip, min(length, snaplen));
-               snapend += abuf - (u_char *)ip;
-               packetp = abuf;
-               ip = (struct ip *)abuf;
-               /* We really want libpcap to give us aligned packets */
-               if (!didwarn) {
-                       warning("compensating for unaligned libpcap packets");
-                       ++didwarn;
-               }
-       }
-#endif

        if ((u_char *)(ip + 1) > snapend) {
                printf("[|ip]");
                return;
        if ((u_char *)(ip + 1) > snapend) {
                printf("[|ip]");
                return;


@@ -301,18 +386,71 @@ ip_print(register const u_char *bp, register u_int length)
                return;
        }
 
                return;
        }
 

-       len = ntohs(ip->ip_len);
+       len = EXTRACT_16BITS(&ip->ip_len);

        if (length < len)
                (void)printf("truncated-ip - %d bytes missing! ",
                        len - length);
        len -= hlen;
        len0 = len;
 
        if (length < len)
                (void)printf("truncated-ip - %d bytes missing! ",
                        len - length);
        len -= hlen;
        len0 = len;
 

+       off = EXTRACT_16BITS(&ip->ip_off);
+
+        if (vflag) {
+            (void)printf("(tos 0x%x", (int)ip->ip_tos);
+            /* ECN bits */
+            if (ip->ip_tos & 0x03) {
+                switch (ip->ip_tos & 0x03) {
+                case 1:
+                    (void)printf(",ECT(1)");
+                    break;
+                case 2:
+                    (void)printf(",ECT(0)");
+                    break;
+                case 3:
+                    (void)printf(",CE");
+                }
+            }
+
+            if (ip->ip_ttl >= 1)
+                (void)printf(", ttl %3u", ip->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.
+            */
+
+           (void)printf(", id %u, offset %u, flags [%s]",
+                            EXTRACT_16BITS(&ip->ip_id),
+                            (off & 0x1fff) * 8,
+                            bittok2str(ip_frag_values, "none", off & 0xe000 ));
+
+            (void)printf(", length: %u", EXTRACT_16BITS(&ip->ip_len));
+
+            if ((hlen - sizeof(struct ip)) > 0) {
+                (void)printf(", optlength: %u (", hlen - (u_int)sizeof(struct ip));
+                ip_optprint((u_char *)(ip + 1), hlen - sizeof(struct ip));
+                printf(" )");
+            }
+
+           if ((u_char *)ip + hlen <= snapend) {
+               sum = in_cksum((const u_short *)ip, hlen, 0);
+               if (sum != 0) {
+                   ip_sum = EXTRACT_16BITS(&ip->ip_sum);
+                   (void)printf("%sbad cksum %x (->%x)!", sep,
+                            ip_sum,
+                            in_cksum_shouldbe(ip_sum, sum));
+                   sep = ", ";
+               }
+           }
+
+            printf(") ");
+       }
+

        /*
         * If this is fragment zero, hand it to the next higher
         * level protocol.
         */
        /*
         * 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;
                nh = ip->ip_p;
        if ((off & 0x1fff) == 0) {
                cp = (const u_char *)ip + hlen;
                nh = ip->ip_p;


@@ -333,7 +471,7 @@ again:
 #endif
                case IPPROTO_AH:
                        nh = *cp;
 #endif
                case IPPROTO_AH:
                        nh = *cp;

-                       advance = ah_print(cp, (const u_char *)ip);
+                       advance = ah_print(cp);

                        cp += advance;
                        len -= advance;
                        goto again;
                        cp += advance;
                        len -= advance;
                        goto again;


@@ -359,7 +497,7 @@ again:
                case IPPROTO_IPCOMP:
                    {
                        int enh;
                case IPPROTO_IPCOMP:
                    {
                        int enh;

-                       advance = ipcomp_print(cp, (const u_char *)ip, &enh);
+                       advance = ipcomp_print(cp, &enh);

                        cp += advance;
                        len -= advance;
                        if (enh < 0)
                        cp += advance;
                        len -= advance;
                        if (enh < 0)


@@ -369,7 +507,7 @@ again:
                    }
 
                case IPPROTO_SCTP:
                    }
 
                case IPPROTO_SCTP:

-                       sctp_print(cp, (const u_char *)ip, len);
+                       sctp_print(cp, (const u_char *)ip, len);

                        break;
 
                case IPPROTO_TCP:
                        break;
 
                case IPPROTO_TCP:


@@ -381,7 +519,8 @@ again:
                        break;
 
                case IPPROTO_ICMP:
                        break;
 
                case IPPROTO_ICMP:

-                       icmp_print(cp, len, (const u_char *)ip);
+                       /* pass on the MF bit plus the offset to detect fragments */
+                       icmp_print(cp, len, (const u_char *)ip, (off & 0x3fff));

                        break;
 
 #ifndef IPPROTO_IGRP
                        break;
 
 #ifndef IPPROTO_IGRP


@@ -396,7 +535,7 @@ again:
                        break;
 
                case IPPROTO_EGP:
                        break;
 
                case IPPROTO_EGP:

-                       egp_print(cp, len, (const u_char *)ip);
+                       egp_print(cp);

                        break;
 
 #ifndef IPPROTO_OSPF
                        break;
 
 #ifndef IPPROTO_OSPF


@@ -432,6 +571,12 @@ again:
                        break;
 #endif /*INET6*/
 
                        break;
 #endif /*INET6*/
 

+#ifndef IPPROTO_RSVP
+#define IPPROTO_RSVP 46
+#endif
+               case IPPROTO_RSVP:
+                       rsvp_print(cp, len);
+                       break;

 
 #ifndef IPPROTO_GRE
 #define IPPROTO_GRE 47
 
 #ifndef IPPROTO_GRE
 #define IPPROTO_GRE 47


@@ -470,95 +615,23 @@ again:
                        printf(" %d", len);
                        break;
                }
                        printf(" %d", len);
                        break;
                }

-       }
-
-       /* Ultra quiet now means that all this stuff should be suppressed */
-       /* res 3-Nov-98 */
-       if (qflag > 1) return;
-
-
-       /*
-        * for fragmented datagrams, print id:size@offset.  On all
-        * but the last stick a "+".  For unfragmented datagrams, note
-        * the don't fragment flag.
-        */
-       len = len0;     /* get the original length */
-       if (off & 0x3fff) {
-               /*
-                * if this isn't the first frag, we're missing the
-                * next level protocol header.  print the ip addr
-                * and the protocol.
-                */
-               if (off & 0x1fff) {
-                       (void)printf("%s > %s:", ipaddr_string(&ip->ip_src),
-                                     ipaddr_string(&ip->ip_dst));
-                       if ((proto = getprotobynumber(ip->ip_p)) != NULL)
-                               (void)printf(" %s", proto->p_name);
-                       else
-                               (void)printf(" ip-proto-%d", ip->ip_p);
-               }
-#ifndef IP_MF
-#define IP_MF 0x2000
-#endif /* IP_MF */
-#ifndef IP_DF
-#define IP_DF 0x4000
-#endif /* IP_DF */
-               (void)printf(" (frag %d:%u@%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);
-               /* ECN bits */
-               if (ip->ip_tos & 0x03) {
-                       switch (ip->ip_tos & 0x03) {
-                       case 1:
-                               (void)printf(",ECT(1)");
-                               break;
-                       case 2:
-                               (void)printf(",ECT(0)");
-                               break;
-                       case 3:
-                               (void)printf(",CE");
-                       }
-               }
-               (void)printf("] ");
-       }
-
-       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 = ", ";
-               }
-               (void)printf("%slen %d", sep, (int)ntohs(ip->ip_len));
-               sep = ", ";
-               if ((u_char *)ip + hlen <= snapend) {
-                       sum = in_cksum((const u_short *)ip, hlen, 0);
-                       if (sum != 0) {
-                               (void)printf("%sbad cksum %x!", sep,
-                                            ntohs(ip->ip_sum));
-                               sep = ", ";
-                       }
-               }
-               if ((hlen -= sizeof(struct ip)) > 0) {
-                       (void)printf("%soptlen=%d", sep, hlen);
-                       ip_optprint((u_char *)(ip + 1), hlen);
-               }
-               printf(")");
+       } else {
+           /* Ultra quiet now means that all this stuff should be suppressed */
+           if (qflag > 1) return;
+
+           /*
+            * if this isn't the first frag, we're missing the
+            * next level protocol header.  print the ip addr
+            * and the protocol.
+            */
+           if (off & 0x1fff) {
+               (void)printf("%s > %s:", ipaddr_string(&ip->ip_src),
+                            ipaddr_string(&ip->ip_dst));
+               if ((proto = getprotobynumber(ip->ip_p)) != NULL)
+                   (void)printf(" %s", proto->p_name);
+               else
+                   (void)printf(" ip-proto-%d", ip->ip_p);
+           } 

        }
 }
 
        }
 }
 


@@ -587,3 +660,6 @@ ipN_print(register const u_char *bp, register u_int length)
                return;
        }
 }
                return;
        }
 }

+
+
+