]> The Tcpdump Group git mirrors - tcpdump/blobdiff - print-ospf6.c
Use more the EXTRACT_U_1() macro (40/n)
[tcpdump] / print-ospf6.c
index 1a89bd68add6999192f78ea9d5068225d66952b3..b08aa50e33e4682f14b53497dc0f86e700917eec 100644 (file)
  * OSPF support contributed by Jeffrey Honig ([email protected])
  */
 
-#define NETDISSECT_REWORKED
+/* \summary: IPv6 Open Shortest Path First (OSPFv3) printer */
+
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 
-#include <tcpdump-stdinc.h>
+#include <netdissect-stdinc.h>
 
 #include <string.h>
 
-#include "interface.h"
+#include "netdissect.h"
 #include "addrtoname.h"
 #include "extract.h"
 
 #define OSPF6_AT_HDRLEN             16U
 #define OSPF6_AUTH_TYPE_HMAC        0x0001
 
-typedef u_int32_t rtrid_t;
+typedef uint32_t rtrid_t;
 
 /* link state advertisement header */
 struct lsa6_hdr {
-    u_int16_t ls_age;
-    u_int16_t ls_type;
+    uint16_t ls_age;
+    uint16_t ls_type;
     rtrid_t ls_stateid;
     rtrid_t ls_router;
-    u_int32_t ls_seq;
-    u_int16_t ls_chksum;
-    u_int16_t ls_length;
+    uint32_t ls_seq;
+    uint16_t ls_chksum;
+    uint16_t ls_length;
 };
 
+/* Length of an IPv6 address, in bytes. */
+#define IPV6_ADDR_LEN_BYTES (128/8)
+
 struct lsa6_prefix {
-    u_int8_t lsa_p_len;
-    u_int8_t lsa_p_opt;
-    u_int16_t lsa_p_metric;
-    u_int8_t lsa_p_prefix[4];
+    uint8_t lsa_p_len;
+    uint8_t lsa_p_opt;
+    uint16_t lsa_p_metric;
+    uint8_t lsa_p_prefix[IPV6_ADDR_LEN_BYTES]; /* maximum length */
 };
 
 /* link state advertisement */
@@ -146,36 +150,36 @@ struct lsa6 {
        /* Router links advertisements */
        struct {
            union {
-               u_int8_t flg;
-               u_int32_t opt;
+               uint8_t flg;
+               uint32_t opt;
            } rla_flgandopt;
 #define rla_flags      rla_flgandopt.flg
 #define rla_options    rla_flgandopt.opt
            struct rlalink6 {
-               u_int8_t link_type;
-               u_int8_t link_zero[1];
-               u_int16_t link_metric;
-               u_int32_t link_ifid;
-               u_int32_t link_nifid;
+               uint8_t link_type;
+               uint8_t link_zero[1];
+               uint16_t link_metric;
+               uint32_t link_ifid;
+               uint32_t link_nifid;
                rtrid_t link_nrtid;
            } rla_link[1];              /* may repeat   */
        } un_rla;
 
        /* Network links advertisements */
        struct {
-           u_int32_t nla_options;
+           uint32_t nla_options;
            rtrid_t nla_router[1];      /* may repeat   */
        } un_nla;
 
        /* Inter Area Prefix LSA */
        struct {
-           u_int32_t inter_ap_metric;
+           uint32_t inter_ap_metric;
            struct lsa6_prefix inter_ap_prefix[1];
        } un_inter_ap;
 
        /* AS external links advertisements */
        struct {
-           u_int32_t asla_metric;
+           uint32_t asla_metric;
            struct lsa6_prefix asla_prefix[1];
            /* some optional fields follow */
        } un_asla;
@@ -184,12 +188,12 @@ struct lsa6 {
        /* Summary links advertisements */
        struct {
            struct in_addr sla_mask;
-           u_int32_t sla_tosmetric[1]; /* may repeat   */
+           uint32_t sla_tosmetric[1];  /* may repeat   */
        } un_sla;
 
        /* Multicast group membership */
        struct mcla {
-           u_int32_t mcla_vtype;
+           uint32_t mcla_vtype;
            struct in_addr mcla_vid;
        } un_mcla[1];
 #endif
@@ -199,20 +203,20 @@ struct lsa6 {
        /* Link LSA */
        struct llsa {
            union {
-               u_int8_t pri;
-               u_int32_t opt;
+               uint8_t pri;
+               uint32_t opt;
            } llsa_priandopt;
 #define llsa_priority  llsa_priandopt.pri
 #define llsa_options   llsa_priandopt.opt
            struct in6_addr llsa_lladdr;
-           u_int32_t llsa_nprefix;
+           uint32_t llsa_nprefix;
            struct lsa6_prefix llsa_prefix[1];
        } un_llsa;
 
        /* Intra-Area-Prefix */
        struct {
-           u_int16_t intra_ap_nprefix;
-           u_int16_t intra_ap_lstype;
+           uint16_t intra_ap_nprefix;
+           uint16_t intra_ap_lstype;
            rtrid_t intra_ap_lsid;
            rtrid_t intra_ap_rtid;
            struct lsa6_prefix intra_ap_prefix[1];
@@ -224,68 +228,61 @@ struct lsa6 {
  * the main header
  */
 struct ospf6hdr {
-    u_int8_t ospf6_version;
-    u_int8_t ospf6_type;
-    u_int16_t ospf6_len;
+    uint8_t ospf6_version;
+    uint8_t ospf6_type;
+    uint16_t ospf6_len;
     rtrid_t ospf6_routerid;
     rtrid_t ospf6_areaid;
-    u_int16_t ospf6_chksum;
-    u_int8_t ospf6_instanceid;
-    u_int8_t ospf6_rsvd;
-    union {
+    uint16_t ospf6_chksum;
+    uint8_t ospf6_instanceid;
+    uint8_t ospf6_rsvd;
+};
 
-       /* Hello packet */
-       struct {
-           u_int32_t hello_ifid;
-           union {
-               u_int8_t pri;
-               u_int32_t opt;
-           } hello_priandopt;
+/*
+ * The OSPF6 header length is 16 bytes, regardless of how your compiler
+ * might choose to pad the above structure.
+ */
+#define OSPF6HDR_LEN    16
+
+/* Hello packet */
+struct hello6 {
+    uint32_t hello_ifid;
+    union {
+       uint8_t pri;
+       uint32_t opt;
+    } hello_priandopt;
 #define hello_priority hello_priandopt.pri
 #define hello_options  hello_priandopt.opt
-           u_int16_t hello_helloint;
-           u_int16_t hello_deadint;
-           rtrid_t hello_dr;
-           rtrid_t hello_bdr;
-           rtrid_t hello_neighbor[1]; /* may repeat    */
-       } un_hello;
-
-       /* Database Description packet */
-       struct {
-           u_int32_t db_options;
-           u_int16_t db_mtu;
-           u_int8_t db_mbz;
-           u_int8_t db_flags;
-           u_int32_t db_seq;
-           struct lsa6_hdr db_lshdr[1]; /* may repeat  */
-       } un_db;
-
-       /* Link State Request */
-       struct lsr6 {
-           u_int16_t ls_mbz;
-           u_int16_t ls_type;
-           rtrid_t ls_stateid;
-           rtrid_t ls_router;
-       } un_lsr[1];            /* may repeat   */
-
-       /* Link State Update */
-       struct {
-           u_int32_t lsu_count;
-           struct lsa6 lsu_lsa[1]; /* may repeat       */
-       } un_lsu;
+    uint16_t hello_helloint;
+    uint16_t hello_deadint;
+    rtrid_t hello_dr;
+    rtrid_t hello_bdr;
+    rtrid_t hello_neighbor[1]; /* may repeat   */
+};
 
-       /* Link State Acknowledgement */
-       struct {
-           struct lsa6_hdr lsa_lshdr[1]; /* may repeat */
-       } un_lsa ;
-    } ospf6_un ;
+/* Database Description packet */
+struct dd6 {
+    uint32_t db_options;
+    uint16_t db_mtu;
+    uint8_t db_mbz;
+    uint8_t db_flags;
+    uint32_t db_seq;
+    struct lsa6_hdr db_lshdr[1]; /* may repeat */
 };
 
-#define        ospf6_hello     ospf6_un.un_hello
-#define        ospf6_db        ospf6_un.un_db
-#define        ospf6_lsr       ospf6_un.un_lsr
-#define        ospf6_lsu       ospf6_un.un_lsu
-#define        ospf6_lsa       ospf6_un.un_lsa
+/* Link State Request */
+struct lsr6 {
+    uint16_t ls_mbz;
+    uint16_t ls_type;
+    rtrid_t ls_stateid;
+    rtrid_t ls_router;
+};
+
+/* Link State Update */
+struct lsu6 {
+    uint32_t lsu_count;
+    struct lsa6 lsu_lsa[1]; /* may repeat      */
+};
 
 static const char tstr[] = " [|ospf3]";
 
@@ -390,18 +387,19 @@ static int
 ospf6_print_lshdr(netdissect_options *ndo,
                   register const struct lsa6_hdr *lshp, const u_char *dataend)
 {
-       if ((u_char *)(lshp + 1) > dataend)
+       if ((const u_char *)(lshp + 1) > dataend)
                goto trunc;
        ND_TCHECK(lshp->ls_type);
        ND_TCHECK(lshp->ls_seq);
 
        ND_PRINT((ndo, "\n\t  Advertising Router %s, seq 0x%08x, age %us, length %u",
                ipaddr_string(ndo, &lshp->ls_router),
-               EXTRACT_32BITS(&lshp->ls_seq),
-               EXTRACT_16BITS(&lshp->ls_age),
-               EXTRACT_16BITS(&lshp->ls_length)-(u_int)sizeof(struct lsa6_hdr)));
+               EXTRACT_BE_U_4(&lshp->ls_seq),
+               EXTRACT_BE_U_2(&lshp->ls_age),
+               EXTRACT_BE_U_2(&lshp->ls_length)-(u_int)sizeof(struct lsa6_hdr)));
 
-       ospf6_print_ls_type(ndo, EXTRACT_16BITS(&lshp->ls_type), &lshp->ls_stateid);
+       ospf6_print_ls_type(ndo, EXTRACT_BE_U_2(&lshp->ls_type),
+                           &lshp->ls_stateid);
 
        return (0);
 trunc:
@@ -410,16 +408,16 @@ trunc:
 
 static int
 ospf6_print_lsaprefix(netdissect_options *ndo,
-                      const u_int8_t *tptr, u_int lsa_length)
+                      const uint8_t *tptr, u_int lsa_length)
 {
-       const struct lsa6_prefix *lsapp = (struct lsa6_prefix *)tptr;
+       const struct lsa6_prefix *lsapp = (const struct lsa6_prefix *)tptr;
        u_int wordlen;
        struct in6_addr prefix;
 
-       if (lsa_length < sizeof (*lsapp) - 4)
+       if (lsa_length < sizeof (*lsapp) - IPV6_ADDR_LEN_BYTES)
                goto trunc;
-       lsa_length -= sizeof (*lsapp) - 4;
-       ND_TCHECK2(*lsapp, sizeof (*lsapp) - 4);
+       lsa_length -= sizeof (*lsapp) - IPV6_ADDR_LEN_BYTES;
+       ND_TCHECK2(*lsapp, sizeof (*lsapp) - IPV6_ADDR_LEN_BYTES);
        wordlen = (lsapp->lsa_p_len + 31) / 32;
        if (wordlen * 4 > sizeof(struct in6_addr)) {
                ND_PRINT((ndo, " bogus prefixlen /%d", lsapp->lsa_p_len));
@@ -438,8 +436,8 @@ ospf6_print_lsaprefix(netdissect_options *ndo,
                    bittok2str(ospf6_lsa_prefix_option_values,
                               "none", lsapp->lsa_p_opt)));
         }
-        ND_PRINT((ndo, ", metric %u", EXTRACT_16BITS(&lsapp->lsa_p_metric)));
-       return sizeof(*lsapp) - 4 + wordlen * 4;
+        ND_PRINT((ndo, ", metric %u", EXTRACT_BE_U_2(&lsapp->lsa_p_metric)));
+       return sizeof(*lsapp) - IPV6_ADDR_LEN_BYTES + wordlen * 4;
 
 trunc:
        return -1;
@@ -465,18 +463,18 @@ ospf6_print_lsa(netdissect_options *ndo,
        register const struct llsa *llsap;
        register const struct lsa6_prefix *lsapp;
 #if 0
-       register const u_int32_t *lp;
+       register const uint32_t *lp;
 #endif
        register u_int prefixes;
        register int bytelen;
        register u_int length, lsa_length;
-       u_int32_t flags32;
-       const u_int8_t *tptr;
+       uint32_t flags32;
+       const uint8_t *tptr;
 
        if (ospf6_print_lshdr(ndo, &lsap->ls_hdr, dataend))
                return (1);
        ND_TCHECK(lsap->ls_hdr.ls_length);
-        length = EXTRACT_16BITS(&lsap->ls_hdr.ls_length);
+        length = EXTRACT_BE_U_2(&lsap->ls_hdr.ls_length);
 
        /*
         * The LSA length includes the length of the header;
@@ -484,12 +482,12 @@ ospf6_print_lsa(netdissect_options *ndo,
         * If it does, find the length of what follows the
         * header.
         */
-        if (length < sizeof(struct lsa6_hdr) || (u_char *)lsap + length > dataend)
+        if (length < sizeof(struct lsa6_hdr) || (const u_char *)lsap + length > dataend)
                return (1);
         lsa_length = length - sizeof(struct lsa6_hdr);
-        tptr = (u_int8_t *)lsap+sizeof(struct lsa6_hdr);
+        tptr = (const uint8_t *)lsap+sizeof(struct lsa6_hdr);
 
-       switch (EXTRACT_16BITS(&lsap->ls_hdr.ls_type)) {
+       switch (EXTRACT_BE_U_2(&lsap->ls_hdr.ls_type)) {
        case LS_TYPE_ROUTER | LS_SCOPE_AREA:
                if (lsa_length < sizeof (lsap->lsa_un.un_rla.rla_options))
                        return (1);
@@ -497,7 +495,7 @@ ospf6_print_lsa(netdissect_options *ndo,
                ND_TCHECK(lsap->lsa_un.un_rla.rla_options);
                ND_PRINT((ndo, "\n\t      Options [%s]",
                          bittok2str(ospf6_option_values, "none",
-                         EXTRACT_32BITS(&lsap->lsa_un.un_rla.rla_options))));
+                         EXTRACT_BE_U_4(&lsap->lsa_un.un_rla.rla_options))));
                ND_PRINT((ndo, ", RLA-Flags [%s]",
                          bittok2str(ospf6_rla_flag_values, "none",
                          lsap->lsa_un.un_rla.rla_flags)));
@@ -539,7 +537,7 @@ ospf6_print_lsa(netdissect_options *ndo,
                                    rlp->link_type));
                                return (0);
                        }
-                       ND_PRINT((ndo, ", metric %d", EXTRACT_16BITS(&rlp->link_metric)));
+                       ND_PRINT((ndo, ", metric %d", EXTRACT_BE_U_2(&rlp->link_metric)));
                        rlp++;
                }
                break;
@@ -551,7 +549,7 @@ ospf6_print_lsa(netdissect_options *ndo,
                ND_TCHECK(lsap->lsa_un.un_nla.nla_options);
                ND_PRINT((ndo, "\n\t      Options [%s]",
                          bittok2str(ospf6_option_values, "none",
-                         EXTRACT_32BITS(&lsap->lsa_un.un_nla.nla_options))));
+                         EXTRACT_BE_U_4(&lsap->lsa_un.un_nla.nla_options))));
 
                ND_PRINT((ndo, "\n\t      Connected Routers:"));
                ap = lsap->lsa_un.un_nla.nla_router;
@@ -571,9 +569,9 @@ ospf6_print_lsa(netdissect_options *ndo,
                lsa_length -= sizeof (lsap->lsa_un.un_inter_ap.inter_ap_metric);
                ND_TCHECK(lsap->lsa_un.un_inter_ap.inter_ap_metric);
                ND_PRINT((ndo, ", metric %u",
-                       EXTRACT_32BITS(&lsap->lsa_un.un_inter_ap.inter_ap_metric) & SLA_MASK_METRIC));
+                       EXTRACT_BE_U_4(&lsap->lsa_un.un_inter_ap.inter_ap_metric) & SLA_MASK_METRIC));
 
-               tptr = (u_int8_t *)lsap->lsa_un.un_inter_ap.inter_ap_prefix;
+               tptr = (const uint8_t *)lsap->lsa_un.un_inter_ap.inter_ap_prefix;
                while (lsa_length != 0) {
                        bytelen = ospf6_print_lsaprefix(ndo, tptr, lsa_length);
                        if (bytelen < 0)
@@ -588,15 +586,15 @@ ospf6_print_lsa(netdissect_options *ndo,
                        return (1);
                lsa_length -= sizeof (lsap->lsa_un.un_asla.asla_metric);
                ND_TCHECK(lsap->lsa_un.un_asla.asla_metric);
-               flags32 = EXTRACT_32BITS(&lsap->lsa_un.un_asla.asla_metric);
+               flags32 = EXTRACT_BE_U_4(&lsap->lsa_un.un_asla.asla_metric);
                ND_PRINT((ndo, "\n\t     Flags [%s]",
                          bittok2str(ospf6_asla_flag_values, "none", flags32)));
                ND_PRINT((ndo, " metric %u",
-                      EXTRACT_32BITS(&lsap->lsa_un.un_asla.asla_metric) &
+                      EXTRACT_BE_U_4(&lsap->lsa_un.un_asla.asla_metric) &
                       ASLA_MASK_METRIC));
 
-               tptr = (u_int8_t *)lsap->lsa_un.un_asla.asla_prefix;
-               lsapp = (struct lsa6_prefix *)tptr;
+               tptr = (const uint8_t *)lsap->lsa_un.un_asla.asla_prefix;
+               lsapp = (const struct lsa6_prefix *)tptr;
                bytelen = ospf6_print_lsaprefix(ndo, tptr, lsa_length);
                if (bytelen < 0)
                        goto trunc;
@@ -604,9 +602,9 @@ ospf6_print_lsa(netdissect_options *ndo,
                tptr += bytelen;
 
                if ((flags32 & ASLA_FLAG_FWDADDR) != 0) {
-                       struct in6_addr *fwdaddr6;
+                       const struct in6_addr *fwdaddr6;
 
-                       fwdaddr6 = (struct in6_addr *)tptr;
+                       fwdaddr6 = (const struct in6_addr *)tptr;
                        if (lsa_length < sizeof (*fwdaddr6))
                                return (1);
                        lsa_length -= sizeof (*fwdaddr6);
@@ -617,23 +615,23 @@ ospf6_print_lsa(netdissect_options *ndo,
                }
 
                if ((flags32 & ASLA_FLAG_ROUTETAG) != 0) {
-                       if (lsa_length < sizeof (u_int32_t))
+                       if (lsa_length < sizeof (uint32_t))
                                return (1);
-                       lsa_length -= sizeof (u_int32_t);
-                       ND_TCHECK(*(u_int32_t *)tptr);
+                       lsa_length -= sizeof (uint32_t);
+                       ND_TCHECK(*(const uint32_t *)tptr);
                        ND_PRINT((ndo, " tag %s",
-                              ipaddr_string(ndo, (u_int32_t *)tptr)));
-                       tptr += sizeof(u_int32_t);
+                              ipaddr_string(ndo, (const uint32_t *)tptr)));
+                       tptr += sizeof(uint32_t);
                }
 
                if (lsapp->lsa_p_metric) {
-                       if (lsa_length < sizeof (u_int32_t))
+                       if (lsa_length < sizeof (uint32_t))
                                return (1);
-                       lsa_length -= sizeof (u_int32_t);
-                       ND_TCHECK(*(u_int32_t *)tptr);
+                       lsa_length -= sizeof (uint32_t);
+                       ND_TCHECK(*(const uint32_t *)tptr);
                        ND_PRINT((ndo, " RefLSID: %s",
-                              ipaddr_string(ndo, (u_int32_t *)tptr)));
-                       tptr += sizeof(u_int32_t);
+                              ipaddr_string(ndo, (const uint32_t *)tptr)));
+                       tptr += sizeof(uint32_t);
                }
                break;
 
@@ -646,18 +644,19 @@ ospf6_print_lsa(netdissect_options *ndo,
                ND_TCHECK(llsap->llsa_priandopt);
                ND_PRINT((ndo, "\n\t      Options [%s]",
                          bittok2str(ospf6_option_values, "none",
-                         EXTRACT_32BITS(&llsap->llsa_options))));
+                         EXTRACT_BE_U_4(&llsap->llsa_options))));
 
                if (lsa_length < sizeof (llsap->llsa_lladdr) + sizeof (llsap->llsa_nprefix))
                        return (1);
                lsa_length -= sizeof (llsap->llsa_lladdr) + sizeof (llsap->llsa_nprefix);
-                prefixes = EXTRACT_32BITS(&llsap->llsa_nprefix);
+                ND_TCHECK(llsap->llsa_nprefix);
+                prefixes = EXTRACT_BE_U_4(&llsap->llsa_nprefix);
                ND_PRINT((ndo, "\n\t      Priority %d, Link-local address %s, Prefixes %d:",
                        llsap->llsa_priority,
                        ip6addr_string(ndo, &llsap->llsa_lladdr),
                        prefixes));
 
-               tptr = (u_int8_t *)llsap->llsa_prefix;
+               tptr = (const uint8_t *)llsap->llsa_prefix;
                while (prefixes > 0) {
                        bytelen = ospf6_print_lsaprefix(ndo, tptr, lsa_length);
                        if (bytelen < 0)
@@ -675,17 +674,17 @@ ospf6_print_lsa(netdissect_options *ndo,
                lsa_length -= sizeof (lsap->lsa_un.un_intra_ap.intra_ap_rtid);
                ND_TCHECK(lsap->lsa_un.un_intra_ap.intra_ap_rtid);
                ospf6_print_ls_type(ndo,
-                       EXTRACT_16BITS(&lsap->lsa_un.un_intra_ap.intra_ap_lstype),
+                       EXTRACT_BE_U_2(&lsap->lsa_un.un_intra_ap.intra_ap_lstype),
                        &lsap->lsa_un.un_intra_ap.intra_ap_lsid);
 
                if (lsa_length < sizeof (lsap->lsa_un.un_intra_ap.intra_ap_nprefix))
                        return (1);
                lsa_length -= sizeof (lsap->lsa_un.un_intra_ap.intra_ap_nprefix);
                ND_TCHECK(lsap->lsa_un.un_intra_ap.intra_ap_nprefix);
-                prefixes = EXTRACT_16BITS(&lsap->lsa_un.un_intra_ap.intra_ap_nprefix);
+                prefixes = EXTRACT_BE_U_2(&lsap->lsa_un.un_intra_ap.intra_ap_nprefix);
                ND_PRINT((ndo, "\n\t      Prefixes %d:", prefixes));
 
-               tptr = (u_int8_t *)lsap->lsa_un.un_intra_ap.intra_ap_prefix;
+               tptr = (const uint8_t *)lsap->lsa_un.un_intra_ap.intra_ap_prefix;
                while (prefixes > 0) {
                        bytelen = ospf6_print_lsaprefix(ndo, tptr, lsa_length);
                        if (bytelen < 0)
@@ -735,68 +734,76 @@ ospf6_decode_v3(netdissect_options *ndo,
 
        switch (op->ospf6_type) {
 
-       case OSPF_TYPE_HELLO:
+       case OSPF_TYPE_HELLO: {
+               register const struct hello6 *hellop = (const struct hello6 *)((const uint8_t *)op + OSPF6HDR_LEN);
+
+               ND_TCHECK_4(&hellop->hello_options);
                ND_PRINT((ndo, "\n\tOptions [%s]",
                          bittok2str(ospf6_option_values, "none",
-                         EXTRACT_32BITS(&op->ospf6_hello.hello_options))));
+                         EXTRACT_BE_U_4(&hellop->hello_options))));
 
-               ND_TCHECK(op->ospf6_hello.hello_deadint);
+               ND_TCHECK(hellop->hello_deadint);
                ND_PRINT((ndo, "\n\t  Hello Timer %us, Dead Timer %us, Interface-ID %s, Priority %u",
-                         EXTRACT_16BITS(&op->ospf6_hello.hello_helloint),
-                         EXTRACT_16BITS(&op->ospf6_hello.hello_deadint),
-                         ipaddr_string(ndo, &op->ospf6_hello.hello_ifid),
-                         op->ospf6_hello.hello_priority));
+                         EXTRACT_BE_U_2(&hellop->hello_helloint),
+                         EXTRACT_BE_U_2(&hellop->hello_deadint),
+                         ipaddr_string(ndo, &hellop->hello_ifid),
+                         hellop->hello_priority));
 
-               ND_TCHECK(op->ospf6_hello.hello_dr);
-               if (EXTRACT_32BITS(&op->ospf6_hello.hello_dr) != 0)
+               ND_TCHECK(hellop->hello_dr);
+               if (EXTRACT_BE_U_4(&hellop->hello_dr) != 0)
                        ND_PRINT((ndo, "\n\t  Designated Router %s",
-                           ipaddr_string(ndo, &op->ospf6_hello.hello_dr)));
-               ND_TCHECK(op->ospf6_hello.hello_bdr);
-               if (EXTRACT_32BITS(&op->ospf6_hello.hello_bdr) != 0)
+                           ipaddr_string(ndo, &hellop->hello_dr)));
+               ND_TCHECK(hellop->hello_bdr);
+               if (EXTRACT_BE_U_4(&hellop->hello_bdr) != 0)
                        ND_PRINT((ndo, ", Backup Designated Router %s",
-                           ipaddr_string(ndo, &op->ospf6_hello.hello_bdr)));
+                           ipaddr_string(ndo, &hellop->hello_bdr)));
                if (ndo->ndo_vflag > 1) {
                        ND_PRINT((ndo, "\n\t  Neighbor List:"));
-                       ap = op->ospf6_hello.hello_neighbor;
-                       while ((u_char *)ap < dataend) {
+                       ap = hellop->hello_neighbor;
+                       while ((const u_char *)ap < dataend) {
                                ND_TCHECK(*ap);
                                ND_PRINT((ndo, "\n\t    %s", ipaddr_string(ndo, ap)));
                                ++ap;
                        }
                }
                break;  /* HELLO */
+       }
 
-       case OSPF_TYPE_DD:
-               ND_TCHECK(op->ospf6_db.db_options);
+       case OSPF_TYPE_DD: {
+               register const struct dd6 *ddp = (const struct dd6 *)((const uint8_t *)op + OSPF6HDR_LEN);
+
+               ND_TCHECK(ddp->db_options);
                ND_PRINT((ndo, "\n\tOptions [%s]",
                          bittok2str(ospf6_option_values, "none",
-                         EXTRACT_32BITS(&op->ospf6_db.db_options))));
-               ND_TCHECK(op->ospf6_db.db_flags);
+                         EXTRACT_BE_U_4(&ddp->db_options))));
+               ND_TCHECK(ddp->db_flags);
                ND_PRINT((ndo, ", DD Flags [%s]",
-                         bittok2str(ospf6_dd_flag_values,"none",op->ospf6_db.db_flags)));
+                         bittok2str(ospf6_dd_flag_values,"none",ddp->db_flags)));
 
-               ND_TCHECK(op->ospf6_db.db_seq);
+               ND_TCHECK(ddp->db_seq);
                ND_PRINT((ndo, ", MTU %u, DD-Sequence 0x%08x",
-                       EXTRACT_16BITS(&op->ospf6_db.db_mtu),
-                       EXTRACT_32BITS(&op->ospf6_db.db_seq)));
+                       EXTRACT_BE_U_2(&ddp->db_mtu),
+                       EXTRACT_BE_U_4(&ddp->db_seq)));
                if (ndo->ndo_vflag > 1) {
                        /* Print all the LS adv's */
-                       lshp = op->ospf6_db.db_lshdr;
-                       while ((u_char *)lshp < dataend) {
+                       lshp = ddp->db_lshdr;
+                       while ((const u_char *)lshp < dataend) {
                                if (ospf6_print_lshdr(ndo, lshp++, dataend))
                                        goto trunc;
                        }
                }
                break;
+       }
 
        case OSPF_TYPE_LS_REQ:
                if (ndo->ndo_vflag > 1) {
-                       lsrp = op->ospf6_lsr;
-                       while ((u_char *)lsrp < dataend) {
+                       lsrp = (const struct lsr6 *)((const uint8_t *)op + OSPF6HDR_LEN);
+                       while ((const u_char *)lsrp < dataend) {
                                ND_TCHECK(*lsrp);
                                ND_PRINT((ndo, "\n\t  Advertising Router %s",
                                          ipaddr_string(ndo, &lsrp->ls_router)));
-                               ospf6_print_ls_type(ndo, EXTRACT_16BITS(&lsrp->ls_type),
+                               ospf6_print_ls_type(ndo,
+                                                    EXTRACT_BE_U_2(&lsrp->ls_type),
                                                     &lsrp->ls_stateid);
                                ++lsrp;
                        }
@@ -805,23 +812,24 @@ ospf6_decode_v3(netdissect_options *ndo,
 
        case OSPF_TYPE_LS_UPDATE:
                if (ndo->ndo_vflag > 1) {
-                       lsap = op->ospf6_lsu.lsu_lsa;
-                       ND_TCHECK(op->ospf6_lsu.lsu_count);
-                       i = EXTRACT_32BITS(&op->ospf6_lsu.lsu_count);
-                       while ((u_char *)lsap < dataend && i--) {
+                       register const struct lsu6 *lsup = (const struct lsu6 *)((const uint8_t *)op + OSPF6HDR_LEN);
+
+                       ND_TCHECK(lsup->lsu_count);
+                       i = EXTRACT_BE_U_4(&lsup->lsu_count);
+                       lsap = lsup->lsu_lsa;
+                       while ((const u_char *)lsap < dataend && i--) {
                                if (ospf6_print_lsa(ndo, lsap, dataend))
                                        goto trunc;
-                               lsap = (struct lsa6 *)((u_char *)lsap +
-                                   EXTRACT_16BITS(&lsap->ls_hdr.ls_length));
+                               lsap = (const struct lsa6 *)((const u_char *)lsap +
+                                   EXTRACT_BE_U_2(&lsap->ls_hdr.ls_length));
                        }
                }
                break;
 
-
        case OSPF_TYPE_LS_ACK:
                if (ndo->ndo_vflag > 1) {
-                       lshp = op->ospf6_lsa.lsa_lshdr;
-                       while ((u_char *)lshp < dataend) {
+                       lshp = (const struct lsa6_hdr *)((const uint8_t *)op + OSPF6HDR_LEN);
+                       while ((const u_char *)lshp < dataend) {
                                if (ospf6_print_lshdr(ndo, lshp++, dataend))
                                        goto trunc;
                        }
@@ -848,12 +856,12 @@ ospf6_print_lls(netdissect_options *ndo,
        if (len < OSPF_LLS_HDRLEN)
                goto trunc;
        /* Checksum */
-       ND_TCHECK2(*cp, 2);
-       ND_PRINT((ndo, "\n\tLLS Checksum 0x%04x", EXTRACT_16BITS(cp)));
+       ND_TCHECK_2(cp);
+       ND_PRINT((ndo, "\n\tLLS Checksum 0x%04x", EXTRACT_BE_U_2(cp)));
        cp += 2;
        /* LLS Data Length */
-       ND_TCHECK2(*cp, 2);
-       llsdatalen = EXTRACT_16BITS(cp);
+       ND_TCHECK_2(cp);
+       llsdatalen = EXTRACT_BE_U_2(cp);
        ND_PRINT((ndo, ", Data Length %u", llsdatalen));
        if (llsdatalen < OSPF_LLS_HDRLEN || llsdatalen > len)
                goto trunc;
@@ -879,30 +887,30 @@ ospf6_decode_at(netdissect_options *ndo,
        if (len < OSPF6_AT_HDRLEN)
                goto trunc;
        /* Authentication Type */
-       ND_TCHECK2(*cp, 2);
-       ND_PRINT((ndo, "\n\tAuthentication Type %s", tok2str(ospf6_auth_type_str, "unknown (0x%04x)", EXTRACT_16BITS(cp))));
+       ND_TCHECK_2(cp);
+       ND_PRINT((ndo, "\n\tAuthentication Type %s", tok2str(ospf6_auth_type_str, "unknown (0x%04x)", EXTRACT_BE_U_2(cp))));
        cp += 2;
        /* Auth Data Len */
-       ND_TCHECK2(*cp, 2);
-       authdatalen = EXTRACT_16BITS(cp);
+       ND_TCHECK_2(cp);
+       authdatalen = EXTRACT_BE_U_2(cp);
        ND_PRINT((ndo, ", Length %u", authdatalen));
        if (authdatalen < OSPF6_AT_HDRLEN || authdatalen > len)
                goto trunc;
        cp += 2;
        /* Reserved */
-       ND_TCHECK2(*cp, 2);
+       ND_TCHECK_2(cp);
        cp += 2;
        /* Security Association ID */
-       ND_TCHECK2(*cp, 2);
-       ND_PRINT((ndo, ", SAID %u", EXTRACT_16BITS(cp)));
+       ND_TCHECK_2(cp);
+       ND_PRINT((ndo, ", SAID %u", EXTRACT_BE_U_2(cp)));
        cp += 2;
        /* Cryptographic Sequence Number (High-Order 32 Bits) */
-       ND_TCHECK2(*cp, 4);
-       ND_PRINT((ndo, ", CSN 0x%08x", EXTRACT_32BITS(cp)));
+       ND_TCHECK_4(cp);
+       ND_PRINT((ndo, ", CSN 0x%08x", EXTRACT_BE_U_4(cp)));
        cp += 4;
        /* Cryptographic Sequence Number (Low-Order 32 Bits) */
-       ND_TCHECK2(*cp, 4);
-       ND_PRINT((ndo, ":%08x", EXTRACT_32BITS(cp)));
+       ND_TCHECK_4(cp);
+       ND_PRINT((ndo, ":%08x", EXTRACT_BE_U_4(cp)));
        cp += 4;
        /* Authentication Data */
        ND_TCHECK2(*cp, authdatalen - OSPF6_AT_HDRLEN);
@@ -924,11 +932,20 @@ ospf6_decode_v3_trailer(netdissect_options *ndo,
                         const struct ospf6hdr *op, const u_char *cp, const unsigned len)
 {
        int llslen = 0;
-       u_char lls_hello = op->ospf6_type == OSPF_TYPE_HELLO &&
-                          EXTRACT_32BITS(&op->ospf6_hello.hello_options) & OSPF6_OPTION_L;
-       u_char lls_dd    = op->ospf6_type == OSPF_TYPE_DD &&
-                          EXTRACT_32BITS(&op->ospf6_db.db_options) & OSPF6_OPTION_L;
-
+       int lls_hello = 0;
+       int lls_dd = 0;
+
+       if (op->ospf6_type == OSPF_TYPE_HELLO) {
+               const struct hello6 *hellop = (const struct hello6 *)((const uint8_t *)op + OSPF6HDR_LEN);
+               ND_TCHECK(hellop->hello_options);
+               if (EXTRACT_BE_U_4(&hellop->hello_options) & OSPF6_OPTION_L)
+                       lls_hello = 1;
+       } else if (op->ospf6_type == OSPF_TYPE_DD) {
+               const struct dd6 *ddp = (const struct dd6 *)((const uint8_t *)op + OSPF6HDR_LEN);
+               ND_TCHECK(ddp->db_options);
+               if (EXTRACT_BE_U_4(&ddp->db_options) & OSPF6_OPTION_L)
+                       lls_dd = 1;
+       }
        if ((lls_hello || lls_dd) && (llslen = ospf6_print_lls(ndo, cp, len)) < 0)
                goto trunc;
        return ospf6_decode_at(ndo, cp + llslen, len - llslen);
@@ -946,7 +963,7 @@ ospf6_print(netdissect_options *ndo,
        register const char *cp;
        uint16_t datalen;
 
-       op = (struct ospf6hdr *)bp;
+       op = (const struct ospf6hdr *)bp;
 
        /* If the type is valid translate it, or just print the type */
        /* value.  If it's not valid, say so and return */
@@ -963,7 +980,7 @@ ospf6_print(netdissect_options *ndo,
 
        /* OSPFv3 data always comes first and optional trailing data may follow. */
        ND_TCHECK(op->ospf6_len);
-       datalen = EXTRACT_16BITS(&op->ospf6_len);
+       datalen = EXTRACT_BE_U_2(&op->ospf6_len);
        if (datalen > length) {
                ND_PRINT((ndo, " [len %d]", datalen));
                return;
@@ -974,7 +991,7 @@ ospf6_print(netdissect_options *ndo,
        ND_PRINT((ndo, "\n\tRouter-ID %s", ipaddr_string(ndo, &op->ospf6_routerid)));
 
        ND_TCHECK(op->ospf6_areaid);
-       if (EXTRACT_32BITS(&op->ospf6_areaid) != 0)
+       if (EXTRACT_BE_U_4(&op->ospf6_areaid) != 0)
                ND_PRINT((ndo, ", Area %s", ipaddr_string(ndo, &op->ospf6_areaid)));
        else
                ND_PRINT((ndo, ", Backbone Area"));