CMake: Fix the comment about versions. [skip ci]

[tcpdump] / print-icmp.c

diff --git a/print-icmp.c b/print-icmp.c
index 2c4dde25e0503917a44242a9caa6603c26633ee9..9b53a48a28b94abd7cd6d19034eb8a124d0cebe2 100644 (file)
--- a/print-icmp.c
+++ b/print-icmp.c
@@ -21,9 +21,7 @@
 
 /* \summary: Internet Control Message Protocol (ICMP) printer */
 
 
 /* \summary: Internet Control Message Protocol (ICMP) printer */
 

-#ifdef HAVE_CONFIG_H

 #include <config.h>
 #include <config.h>

-#endif

 
 #include "netdissect-stdinc.h"
 
 
 #include "netdissect-stdinc.h"
 


@@ -86,13 +84,10 @@ struct icmp {
 #define        icmp_data       icmp_dun.id_data
 };
 
 #define        icmp_data       icmp_dun.id_data
 };
 

-#define ICMP_MPLS_EXT_EXTRACT_VERSION(x) (((x)&0xf0)>>4)
-#define ICMP_MPLS_EXT_VERSION 2
-

 /*
  * Lower bounds on packet lengths for various types.
  * For the error advice packets must first insure that the
 /*
  * Lower bounds on packet lengths for various types.
  * For the error advice packets must first insure that the

- * packet is large enought to contain the returned ip header.
+ * packet is large enough to contain the returned ip header.

  * Only then can we do the check to see if 64 bits of packet
  * data have been returned, since we need to check the returned
  * ip header length.
  * Only then can we do the check to see if 64 bits of packet
  * data have been returned, since we need to check the returned
  * ip header length.


@@ -150,7 +145,7 @@ struct icmp {
        ((type) == ICMP_UNREACH || (type) == ICMP_SOURCEQUENCH || \
        (type) == ICMP_REDIRECT || (type) == ICMP_TIMXCEED || \
        (type) == ICMP_PARAMPROB)
        ((type) == ICMP_UNREACH || (type) == ICMP_SOURCEQUENCH || \
        (type) == ICMP_REDIRECT || (type) == ICMP_TIMXCEED || \
        (type) == ICMP_PARAMPROB)

-#define        ICMP_MPLS_EXT_TYPE(type) \
+#define        ICMP_MULTIPART_EXT_TYPE(type) \

        ((type) == ICMP_UNREACH || \
          (type) == ICMP_TIMXCEED || \
          (type) == ICMP_PARAMPROB)
        ((type) == ICMP_UNREACH || \
          (type) == ICMP_TIMXCEED || \
          (type) == ICMP_PARAMPROB)


@@ -221,13 +216,17 @@ struct id_rdiscovery {
 };
 
 /*
 };
 
 /*

- * draft-bonica-internet-icmp-08
+ * RFC 4884 - Extended ICMP to Support Multi-Part Messages
+ *
+ * This is a general extension mechanism, based on the mechanism
+ * in draft-bonica-icmp-mpls-02 ICMP Extensions for MultiProtocol
+ * Label Switching.

  *
  * The Destination Unreachable, Time Exceeded
  * and Parameter Problem messages are slightly changed as per
  *
  * The Destination Unreachable, Time Exceeded
  * and Parameter Problem messages are slightly changed as per

- * the above draft. A new Length field gets added to give
- * the caller an idea about the length of the piggypacked
- * IP packet before the MPLS extension header starts.
+ * the above RFC. A new Length field gets added to give
+ * the caller an idea about the length of the piggybacked
+ * IP packet before the extension header starts.

  *
  * The Length field represents length of the padded "original datagram"
  * field  measured in 32-bit words.
  *
  * The Length field represents length of the padded "original datagram"
  * field  measured in 32-bit words.


@@ -259,15 +258,34 @@ struct icmp_ext_t {
     nd_byte     icmp_ext_data[1];
 };
 
     nd_byte     icmp_ext_data[1];
 };
 

-struct icmp_mpls_ext_object_header_t {
+/*
+ * Extract version from the first octet of icmp_ext_version_res.
+ */
+#define ICMP_EXT_EXTRACT_VERSION(x) (((x)&0xf0)>>4)
+
+/*
+ * Current version.
+ */
+#define ICMP_EXT_VERSION 2
+
+/*
+ * Extension object class numbers.
+ *
+ * Class 1 dates back to draft-bonica-icmp-mpls-02.
+ */
+
+/* rfc4950  */
+#define MPLS_STACK_ENTRY_OBJECT_CLASS            1
+
+struct icmp_multipart_ext_object_header_t {

     nd_uint16_t length;
     nd_uint8_t  class_num;
     nd_uint8_t  ctype;
 };
 
     nd_uint16_t length;
     nd_uint8_t  class_num;
     nd_uint8_t  ctype;
 };
 

-static const struct tok icmp_mpls_ext_obj_values[] = {
+static const struct tok icmp_multipart_ext_obj_values[] = {

     { 1, "MPLS Stack Entry" },
     { 1, "MPLS Stack Entry" },

-    { 2, "Extended Payload" },
+    { 2, "Interface Identification" },

     { 0, NULL}
 };
 
     { 0, NULL}
 };
 


@@ -305,8 +323,7 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *
        const struct udphdr *ouh;
         const uint8_t *obj_tptr;
         uint32_t raw_label;
        const struct udphdr *ouh;
         const uint8_t *obj_tptr;
         uint32_t raw_label;

-        const u_char *snapend_save;
-       const struct icmp_mpls_ext_object_header_t *icmp_mpls_ext_object_header;
+       const struct icmp_multipart_ext_object_header_t *icmp_multipart_ext_object_header;

        u_int hlen, mtu, obj_tlen, obj_class_num, obj_ctype;
        uint16_t dport;
        char buf[MAXHOSTNAMELEN + 100];
        u_int hlen, mtu, obj_tlen, obj_class_num, obj_ctype;
        uint16_t dport;
        char buf[MAXHOSTNAMELEN + 100];


@@ -318,14 +335,12 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *
        ip = (const struct ip *)bp2;
        str = buf;
 
        ip = (const struct ip *)bp2;
        str = buf;
 

-       ND_TCHECK_1(dp->icmp_code);

        icmp_type = GET_U_1(dp->icmp_type);
        icmp_code = GET_U_1(dp->icmp_code);
        switch (icmp_type) {
 
        case ICMP_ECHO:
        case ICMP_ECHOREPLY:
        icmp_type = GET_U_1(dp->icmp_type);
        icmp_code = GET_U_1(dp->icmp_code);
        switch (icmp_type) {
 
        case ICMP_ECHO:
        case ICMP_ECHOREPLY:

-               ND_TCHECK_2(dp->icmp_seq);

                (void)snprintf(buf, sizeof(buf), "echo %s, id %u, seq %u",
                                icmp_type == ICMP_ECHO ?
                                "request" : "reply",
                (void)snprintf(buf, sizeof(buf), "echo %s, id %u, seq %u",
                                icmp_type == ICMP_ECHO ?
                                "request" : "reply",


@@ -334,7 +349,6 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *
                break;
 
        case ICMP_UNREACH:
                break;
 
        case ICMP_UNREACH:

-               ND_TCHECK_4(dp->icmp_ip.ip_dst);

                switch (icmp_code) {
 
                case ICMP_UNREACH_NET:
                switch (icmp_code) {
 
                case ICMP_UNREACH_NET:


@@ -350,7 +364,6 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *
                        break;
 
                case ICMP_UNREACH_PROTOCOL:
                        break;
 
                case ICMP_UNREACH_PROTOCOL:

-                       ND_TCHECK_1(dp->icmp_ip.ip_p);

                        (void)snprintf(buf, sizeof(buf),
                            "%s protocol %u unreachable",
                            GET_IPADDR_STRING(dp->icmp_ip.ip_dst),
                        (void)snprintf(buf, sizeof(buf),
                            "%s protocol %u unreachable",
                            GET_IPADDR_STRING(dp->icmp_ip.ip_dst),


@@ -362,7 +375,6 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *
                        oip = &dp->icmp_ip;
                        hlen = IP_HL(oip) * 4;
                        ouh = (const struct udphdr *)(((const u_char *)oip) + hlen);
                        oip = &dp->icmp_ip;
                        hlen = IP_HL(oip) * 4;
                        ouh = (const struct udphdr *)(((const u_char *)oip) + hlen);

-                       ND_TCHECK_2(ouh->uh_dport);

                        dport = GET_BE_U_2(ouh->uh_dport);
                        ip_proto = GET_U_1(oip->ip_p);
                        switch (ip_proto) {
                        dport = GET_BE_U_2(ouh->uh_dport);
                        ip_proto = GET_U_1(oip->ip_p);
                        switch (ip_proto) {


@@ -483,7 +495,6 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *
                break;
 
        case ICMP_REDIRECT:
                break;
 
        case ICMP_REDIRECT:

-               ND_TCHECK_4(dp->icmp_ip.ip_dst);

                switch (icmp_code) {
 
                case ICMP_REDIRECT_NET:
                switch (icmp_code) {
 
                case ICMP_REDIRECT_NET:


@@ -599,7 +610,6 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *
                        (void)snprintf(buf, sizeof(buf),
                            "parameter problem - code %u", icmp_code);
                else {
                        (void)snprintf(buf, sizeof(buf),
                            "parameter problem - code %u", icmp_code);
                else {

-                       ND_TCHECK_1(dp->icmp_pptr);

                        (void)snprintf(buf, sizeof(buf),
                            "parameter problem - octet %u",
                            GET_U_1(dp->icmp_pptr));
                        (void)snprintf(buf, sizeof(buf),
                            "parameter problem - octet %u",
                            GET_U_1(dp->icmp_pptr));


@@ -607,13 +617,11 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *
                break;
 
        case ICMP_MASKREPLY:
                break;
 
        case ICMP_MASKREPLY:

-               ND_TCHECK_4(dp->icmp_mask);

                (void)snprintf(buf, sizeof(buf), "address mask is 0x%08x",
                    GET_BE_U_4(dp->icmp_mask));
                break;
 
        case ICMP_TSTAMP:
                (void)snprintf(buf, sizeof(buf), "address mask is 0x%08x",
                    GET_BE_U_4(dp->icmp_mask));
                break;
 
        case ICMP_TSTAMP:

-               ND_TCHECK_2(dp->icmp_seq);

                (void)snprintf(buf, sizeof(buf),
                    "time stamp query id %u seq %u",
                    GET_BE_U_2(dp->icmp_id),
                (void)snprintf(buf, sizeof(buf),
                    "time stamp query id %u seq %u",
                    GET_BE_U_2(dp->icmp_id),


@@ -657,30 +665,42 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *
 
         /*
          * print the remnants of the IP packet.
 
         /*
          * print the remnants of the IP packet.

-         * save the snaplength as this may get overidden in the IP printer.
+         * save the snaplength as this may get overridden in the IP printer.

          */
        if (ndo->ndo_vflag >= 1 && ICMP_ERRTYPE(icmp_type)) {
          */
        if (ndo->ndo_vflag >= 1 && ICMP_ERRTYPE(icmp_type)) {

+               const u_char *snapend_save;
+

                bp += 8;
                ND_PRINT("\n\t");
                ip = (const struct ip *)bp;
                bp += 8;
                ND_PRINT("\n\t");
                ip = (const struct ip *)bp;

-                snapend_save = ndo->ndo_snapend;
-               ND_TCHECK_2(ip->ip_len);
+               snapend_save = ndo->ndo_snapend;
+               /*
+                * Update the snapend because extensions (MPLS, ...) may be
+                * present after the IP packet. In this case the current
+                * (outer) packet's snapend is not what ip_print() needs to
+                * decode an IP packet nested in the middle of an ICMP payload.
+                *
+                * This prevents that, in ip_print(), for the nested IP packet,
+                * the remaining length < remaining caplen.
+                */
+               ndo->ndo_snapend = ND_MIN(bp + GET_BE_U_2(ip->ip_len),
+                                         ndo->ndo_snapend);

                ip_print(ndo, bp, GET_BE_U_2(ip->ip_len));
                ip_print(ndo, bp, GET_BE_U_2(ip->ip_len));

-                ndo->ndo_snapend = snapend_save;
+               ndo->ndo_snapend = snapend_save;

        }
 
        /* ndo_protocol reassignment after ip_print() call */
        ndo->ndo_protocol = "icmp";
 
         /*
        }
 
        /* ndo_protocol reassignment after ip_print() call */
        ndo->ndo_protocol = "icmp";
 
         /*

-         * Attempt to decode the MPLS extensions only for some ICMP types.
+         * Attempt to decode multi-part message extensions (rfc4884) only for some ICMP types.

          */
          */

-        if (ndo->ndo_vflag >= 1 && plen > ICMP_EXTD_MINLEN && ICMP_MPLS_EXT_TYPE(icmp_type)) {
+        if (ndo->ndo_vflag >= 1 && plen > ICMP_EXTD_MINLEN && ICMP_MULTIPART_EXT_TYPE(icmp_type)) {

 
             ND_TCHECK_SIZE(ext_dp);
 
             /*
 
             ND_TCHECK_SIZE(ext_dp);
 
             /*

-             * Check first if the mpls extension header shows a non-zero length.
+             * Check first if the multi-part extension header shows a non-zero length.

              * If the length field is not set then silently verify the checksum
              * to check if an extension header is present. This is expedient,
              * however not all implementations set the length field proper.
              * If the length field is not set then silently verify the checksum
              * to check if an extension header is present. This is expedient,
              * however not all implementations set the length field proper.


@@ -694,14 +714,14 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *
                 }
             }
 
                 }
             }
 

-            ND_PRINT("\n\tMPLS extension v%u",
-                   ICMP_MPLS_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)));
+            ND_PRINT("\n\tICMP Multi-Part extension v%u",
+                   ICMP_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)));

 
             /*
              * Sanity checking of the header.
              */
 
             /*
              * Sanity checking of the header.
              */

-            if (ICMP_MPLS_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)) !=
-                ICMP_MPLS_EXT_VERSION) {
+            if (ICMP_EXT_EXTRACT_VERSION(*(ext_dp->icmp_ext_version_res)) !=
+                ICMP_EXT_VERSION) {

                 ND_PRINT(" packet not supported");
                 return;
             }
                 ND_PRINT(" packet not supported");
                 return;
             }


@@ -719,37 +739,36 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *
             hlen -= 4; /* subtract common header size */
             obj_tptr = (const uint8_t *)ext_dp->icmp_ext_data;
 
             hlen -= 4; /* subtract common header size */
             obj_tptr = (const uint8_t *)ext_dp->icmp_ext_data;
 

-            while (hlen > sizeof(struct icmp_mpls_ext_object_header_t)) {
+            while (hlen > sizeof(struct icmp_multipart_ext_object_header_t)) {

 
 

-                icmp_mpls_ext_object_header = (const struct icmp_mpls_ext_object_header_t *)obj_tptr;
-                ND_TCHECK_SIZE(icmp_mpls_ext_object_header);
-                obj_tlen = GET_BE_U_2(icmp_mpls_ext_object_header->length);
-                obj_class_num = GET_U_1(icmp_mpls_ext_object_header->class_num);
-                obj_ctype = GET_U_1(icmp_mpls_ext_object_header->ctype);
-                obj_tptr += sizeof(struct icmp_mpls_ext_object_header_t);
+                icmp_multipart_ext_object_header = (const struct icmp_multipart_ext_object_header_t *)obj_tptr;
+                ND_TCHECK_SIZE(icmp_multipart_ext_object_header);
+                obj_tlen = GET_BE_U_2(icmp_multipart_ext_object_header->length);
+                obj_class_num = GET_U_1(icmp_multipart_ext_object_header->class_num);
+                obj_ctype = GET_U_1(icmp_multipart_ext_object_header->ctype);
+                obj_tptr += sizeof(struct icmp_multipart_ext_object_header_t);

 
                 ND_PRINT("\n\t  %s Object (%u), Class-Type: %u, length %u",
 
                 ND_PRINT("\n\t  %s Object (%u), Class-Type: %u, length %u",

-                       tok2str(icmp_mpls_ext_obj_values,"unknown",obj_class_num),
+                       tok2str(icmp_multipart_ext_obj_values,"unknown",obj_class_num),

                        obj_class_num,
                        obj_ctype,
                        obj_tlen);
 
                        obj_class_num,
                        obj_ctype,
                        obj_tlen);
 

-                hlen-=sizeof(struct icmp_mpls_ext_object_header_t); /* length field includes tlv header */
+                hlen-=sizeof(struct icmp_multipart_ext_object_header_t); /* length field includes tlv header */

 
                 /* infinite loop protection */
                 if ((obj_class_num == 0) ||
 
                 /* infinite loop protection */
                 if ((obj_class_num == 0) ||

-                    (obj_tlen < sizeof(struct icmp_mpls_ext_object_header_t))) {
+                    (obj_tlen < sizeof(struct icmp_multipart_ext_object_header_t))) {

                     return;
                 }
                     return;
                 }

-                obj_tlen-=sizeof(struct icmp_mpls_ext_object_header_t);
+                obj_tlen-=sizeof(struct icmp_multipart_ext_object_header_t);

 
                 switch (obj_class_num) {
 
                 switch (obj_class_num) {

-                case 1:
+                case MPLS_STACK_ENTRY_OBJECT_CLASS:

                     switch(obj_ctype) {
                     case 1:
                     switch(obj_ctype) {
                     case 1:

-                        ND_TCHECK_4(obj_tptr);

                         raw_label = GET_BE_U_4(obj_tptr);
                         raw_label = GET_BE_U_4(obj_tptr);

-                        ND_PRINT("\n\t    label %u, exp %u", MPLS_LABEL(raw_label), MPLS_EXP(raw_label));
+                        ND_PRINT("\n\t    label %u, tc %u", MPLS_LABEL(raw_label), MPLS_TC(raw_label));

                         if (MPLS_STACK(raw_label))
                             ND_PRINT(", [S]");
                         ND_PRINT(", ttl %u", MPLS_TTL(raw_label));
                         if (MPLS_STACK(raw_label))
                             ND_PRINT(", [S]");
                         ND_PRINT(", ttl %u", MPLS_TTL(raw_label));


@@ -759,11 +778,6 @@ icmp_print(netdissect_options *ndo, const u_char *bp, u_int plen, const u_char *
                     }
                     break;
 
                     }
                     break;
 

-               /*
-                *  FIXME those are the defined objects that lack a decoder
-                *  you are welcome to contribute code ;-)
-                */
-                case 2:

                 default:
                     print_unknown_data(ndo, obj_tptr, "\n\t    ", obj_tlen);
                     break;
                 default:
                     print_unknown_data(ndo, obj_tptr, "\n\t    ", obj_tlen);
                     break;