CI: Add warning exemptions for Sun C (suncc-5.14) on Solaris 10

[tcpdump] / print-gre.c

diff --git a/print-gre.c b/print-gre.c
index 136fb69d1b3ed6dba14babcf4d51d2bef3b5f668..1d545b3f8b076a2039e2e8b3300d34d7551b8f86 100644 (file)
--- a/print-gre.c
+++ b/print-gre.c
@@ -30,12 +30,21 @@
 
 /*
  * netdissect printer for GRE - Generic Routing Encapsulation
 
 /*
  * netdissect printer for GRE - Generic Routing Encapsulation

- * RFC1701 (GRE), RFC1702 (GRE IPv4), and RFC2637 (Enhanced GRE)
+ * RFC 1701 (GRE), RFC 1702 (GRE IPv4), RFC 2637 (PPTP, which
+ * has an extended form of GRE), RFC 2784 (revised GRE, with
+ * R, K, S, and s bits and Recur and Offset fields now reserved
+ * in the header, and no optional Key or Sequence number in the
+ * header), and RFC 2890 (proposal to add back the K and S bits
+ * and the optional Key and Sequence number).
+ *
+ * The RFC 2637 PPTP GRE repurposes the Key field to hold a
+ * 16-bit Payload Length and a 16-bit Call ID.
+ *
+ * RFC 7637 (NVGRE) repurposes the Key field to hold a 24-bit
+ * Virtual Subnet ID (VSID) and an 8-bit FlowID.

  */
 
  */
 

-#ifdef HAVE_CONFIG_H

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

-#endif

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


@@ -44,14 +53,7 @@
 #include "addrtostr.h"
 #include "extract.h"
 #include "ethertype.h"
 #include "addrtostr.h"
 #include "extract.h"
 #include "ethertype.h"

-
-
-#define        GRE_CP          0x8000          /* checksum present */
-#define        GRE_RP          0x4000          /* routing present */
-#define        GRE_KP          0x2000          /* key present */
-#define        GRE_SP          0x1000          /* sequence# present */
-#define        GRE_sP          0x0800          /* source routing */
-#define        GRE_AP          0x0080          /* acknowledgment# present */
+#include "gre.h"

 
 static const struct tok gre_flag_values[] = {
     { GRE_CP, "checksum present"},
 
 static const struct tok gre_flag_values[] = {
     { GRE_CP, "checksum present"},


@@ -70,6 +72,26 @@ static const struct tok gre_flag_values[] = {
 #define        GRESRE_IP       0x0800          /* IP */
 #define        GRESRE_ASN      0xfffe          /* ASN */
 
 #define        GRESRE_IP       0x0800          /* IP */
 #define        GRESRE_ASN      0xfffe          /* ASN */
 

+/*
+ * Ethertype values used for GRE (but not elsewhere?).
+ */
+#define GRE_CDP                        0x2000  /* Cisco Discovery Protocol */
+#define GRE_NHRP               0x2001  /* Next Hop Resolution Protocol */
+#define GRE_MIKROTIK_EOIP      0x6400  /* MikroTik RouterBoard Ethernet over IP (EoIP) */
+#define GRE_ERSPAN_III         0x22eb
+#define GRE_WCCP               0x883e  /* Web Cache C* Protocol */
+#define GRE_ERSPAN_I_II                0x88be
+
+struct wccp_redirect {
+       nd_uint8_t      flags;
+#define WCCP_T                 (1 << 7)
+#define WCCP_A                 (1 << 6)
+#define WCCP_U                 (1 << 5)
+       nd_uint8_t      ServiceId;
+       nd_uint8_t      AltBucket;
+       nd_uint8_t      PriBucket;
+};
+

 static void gre_print_0(netdissect_options *, const u_char *, u_int);
 static void gre_print_1(netdissect_options *, const u_char *, u_int);
 static int gre_sre_print(netdissect_options *, uint16_t, uint8_t, uint8_t, const u_char *, u_int);
 static void gre_print_0(netdissect_options *, const u_char *, u_int);
 static void gre_print_1(netdissect_options *, const u_char *, u_int);
 static int gre_sre_print(netdissect_options *, uint16_t, uint8_t, uint8_t, const u_char *, u_int);


@@ -141,10 +163,21 @@ gre_print_0(netdissect_options *ndo, const u_char *bp, u_int length)
        }
 
        if (flags & GRE_KP) {
        }
 
        if (flags & GRE_KP) {

+               uint32_t key;
+

                ND_ICHECK_U(len, <, 4);
                ND_ICHECK_U(len, <, 4);

-               ND_PRINT(", key=0x%x", GET_BE_U_4(bp));
+               key = GET_BE_U_4(bp);

                bp += 4;
                len -= 4;
                bp += 4;
                len -= 4;

+
+               /*
+                * OpenBSD shows this as both a 32-bit
+                * (decimal) key value and a VSID+FlowID
+                * pair, with the VSID in decimal and
+                * the FlowID in hex, as key=<Key>|<VSID>+<FlowID>,
+                * in case this is NVGRE.
+                */
+               ND_PRINT(", key=0x%x", key);

        }
 
        if (flags & GRE_SP) {
        }
 
        if (flags & GRE_SP) {


@@ -191,6 +224,59 @@ gre_print_0(netdissect_options *ndo, const u_char *bp, u_int length)
                ND_PRINT("\n\t"); /* if verbose go multiline */
 
        switch (prot) {
                ND_PRINT("\n\t"); /* if verbose go multiline */
 
        switch (prot) {

+       case 0x0000:
+               /*
+                * 0x0000 is reserved, but Cisco, at least, appears to
+                * use it for keep-alives; see, for example,
+                * https://www.cisco.com/c/en/us/support/docs/ip/generic-routing-encapsulation-gre/118370-technote-gre-00.html#anc1
+                */
+               ND_PRINT("keep-alive");
+               break;
+       case GRE_WCCP:
+               /*
+                * This is a bit weird.
+                *
+                * This may either just mean "IPv4" or it may mean
+                * "IPv4 preceded by a WCCP redirect header".  We
+                * check to see if the first octet looks like the
+                * beginning of an IPv4 header and, if not, dissect
+                * it "IPv4 preceded by a WCCP redirect header",
+                * otherwise we dissect it as just IPv4.
+                *
+                * See "Packet redirection" in draft-forster-wrec-wccp-v1-00,
+                * section 4.12 "Traffic Forwarding" in
+                * draft-wilson-wrec-wccp-v2-01, and section 3.12.1
+                * "Forwarding using GRE Encapsulation" in
+                * draft-param-wccp-v2rev1-01.
+                */
+               ND_PRINT("wccp ");
+
+               ND_ICHECK_U(len, <, 1);
+               if (GET_U_1(bp) >> 4 != 4) {
+                       /*
+                        * First octet isn't 0x4*, so it's not IPv4.
+                        */
+                       const struct wccp_redirect *wccp;
+                       uint8_t wccp_flags;
+
+                       ND_ICHECK_ZU(len, <, sizeof(*wccp));
+                       wccp = (const struct wccp_redirect *)bp;
+                       wccp_flags = GET_U_1(wccp->flags);
+
+                       ND_PRINT("T:%c A:%c U:%c SId:%u Alt:%u Pri:%u",
+                           (wccp_flags & WCCP_T) ? '1' : '0',
+                           (wccp_flags & WCCP_A) ? '1' : '0',
+                           (wccp_flags & WCCP_U) ? '1' : '0',
+                           GET_U_1(wccp->ServiceId),
+                           GET_U_1(wccp->AltBucket),
+                           GET_U_1(wccp->PriBucket));
+
+                       bp += sizeof(*wccp);
+                       len -= sizeof(*wccp);
+
+                       ND_PRINT(": ");
+               }
+               /* FALLTHROUGH */

        case ETHERTYPE_IP:
                ip_print(ndo, bp, len);
                break;
        case ETHERTYPE_IP:
                ip_print(ndo, bp, len);
                break;


@@ -198,6 +284,7 @@ gre_print_0(netdissect_options *ndo, const u_char *bp, u_int length)
                ip6_print(ndo, bp, len);
                break;
        case ETHERTYPE_MPLS:
                ip6_print(ndo, bp, len);
                break;
        case ETHERTYPE_MPLS:

+       case ETHERTYPE_MPLS_MULTI:

                mpls_print(ndo, bp, len);
                break;
        case ETHERTYPE_IPX:
                mpls_print(ndo, bp, len);
                break;
        case ETHERTYPE_IPX:


@@ -212,6 +299,21 @@ gre_print_0(netdissect_options *ndo, const u_char *bp, u_int length)
        case ETHERTYPE_TEB:
                ether_print(ndo, bp, len, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);
                break;
        case ETHERTYPE_TEB:
                ether_print(ndo, bp, len, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);
                break;

+       case ETHERTYPE_NSH:
+               nsh_print(ndo, bp, len);
+               break;
+       case GRE_ERSPAN_I_II:
+               erspan_i_ii_print(ndo, flags, bp, len);
+               break;
+       case GRE_ERSPAN_III:
+               erspan_iii_print(ndo, bp, len);
+               break;
+       case GRE_CDP:
+               cdp_print(ndo, bp, len);
+               break;
+       case GRE_NHRP:
+               nhrp_print(ndo, bp, len);
+               break;

        default:
                ND_PRINT("gre-proto-0x%x", prot);
        }
        default:
                ND_PRINT("gre-proto-0x%x", prot);
        }


@@ -241,16 +343,48 @@ gre_print_1(netdissect_options *ndo, const u_char *bp, u_int length)
        len -= 2;
        bp += 2;
 
        len -= 2;
        bp += 2;
 

+       /*
+        * This version is used for two purposes:
+        *
+        *  RFC 2637 PPTP;
+        *  Some Mikrotik Ethernet-over-IP hack.
+        */
+       switch (prot) {
+       case GRE_MIKROTIK_EOIP:
+               /*
+                * The MikroTik hack uses only the key field, and uses it
+                * for its own purposes.  If anything other than the version
+                * and K bit are set, report an error and give up.
+                */
+               if ((flags & ~GRE_VERS_MASK) != GRE_KP) {
+                       ND_PRINT(" unknown-eoip-flags-%04x!", flags);
+                       return;
+               }
+               break;
+       default:
+               /*
+                * XXX - what should we do if it's not ETHERTYPE_PPP?
+                */
+               break;
+       }

 
        if (flags & GRE_KP) {
 
        if (flags & GRE_KP) {

-               uint32_t k;
+               /* Skip payload length? */
+               ND_ICHECK_U(len, <, 2);
+               ND_TCHECK_2(bp);
+               len -= 2;
+               bp += 2;

 
 

-               ND_ICHECK_U(len, <, 4);
-               k = GET_BE_U_4(bp);
-               ND_PRINT(", call %u", k & 0xffff);
-               len -= 4;
-               bp += 4;
-       }
+               ND_ICHECK_U(len, <, 2);
+               if (prot == GRE_MIKROTIK_EOIP) {
+                       /* Non-standard */
+                       ND_PRINT(", tunnel-id %u", GET_BE_U_2(bp));
+               } else
+                       ND_PRINT(", call %u", GET_BE_U_2(bp));
+               len -= 2;
+               bp += 2;
+       } else
+               ND_PRINT(", (ERROR: K flag not set)");

 
        if (flags & GRE_SP) {
                ND_ICHECK_U(len, <, 4);
 
        if (flags & GRE_SP) {
                ND_ICHECK_U(len, <, 4);


@@ -266,7 +400,10 @@ gre_print_1(netdissect_options *ndo, const u_char *bp, u_int length)
                len -= 4;
        }
 
                len -= 4;
        }
 

-       if ((flags & GRE_SP) == 0)
+       /*
+        * More non-standard EoIP behavior.
+        */
+       if (prot != GRE_MIKROTIK_EOIP && (flags & GRE_SP) == 0)

                ND_PRINT(", no-payload");
 
        if (ndo->ndo_eflag)
                ND_PRINT(", no-payload");
 
        if (ndo->ndo_eflag)


@@ -275,7 +412,10 @@ gre_print_1(netdissect_options *ndo, const u_char *bp, u_int length)
 
        ND_PRINT(", length %u",length);
 
 
        ND_PRINT(", length %u",length);
 

-       if ((flags & GRE_SP) == 0)
+       /*
+        * More non-standard EoIP behavior.
+        */
+       if (prot != GRE_MIKROTIK_EOIP && (flags & GRE_SP) == 0)

                return;
 
        if (ndo->ndo_vflag < 1)
                return;
 
        if (ndo->ndo_vflag < 1)


@@ -287,6 +427,13 @@ gre_print_1(netdissect_options *ndo, const u_char *bp, u_int length)
        case ETHERTYPE_PPP:
                ppp_print(ndo, bp, len);
                break;
        case ETHERTYPE_PPP:
                ppp_print(ndo, bp, len);
                break;

+       case GRE_MIKROTIK_EOIP:
+               /* MikroTik RouterBoard Ethernet over IP (EoIP) */
+               if (len == 0)
+                       ND_PRINT("keepalive");
+               else
+                       ether_print(ndo, bp, len, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);
+               break;

        default:
                ND_PRINT("gre-proto-0x%x", prot);
                break;
        default:
                ND_PRINT("gre-proto-0x%x", prot);
                break;