Upgrade to tcpdump 4.9.0.

From CHANGES:

  Wednesday January 18, 2017 devel.fx.lebail@orange.fr
  Summary for 4.9.0 tcpdump release
    General updates:
    Improve separation frontend/backend (tcpdump/libnetdissect)
    Don't require IPv6 library support in order to support IPv6 addresses
    Introduce data types to use for integral values in packet structures
    Fix display of timestamps with -tt, -ttt and -ttttt options
    Fix some heap overflows found with American Fuzzy Lop by Hanno Boeck and others
        (More information in the log with CVE-2016-* and CVE-2017-*)
    Change the way protocols print link-layer addresses (Fix heap overflows
        in CALM-FAST and GeoNetworking printers)
    Pass correct caplen value to ether_print() and some other functions
    Fix lookup_nsap() to match what isonsap_string() expects
    Clean up relative time stamp printing (Fix an array overflow)
    Fix some alignment issues with GCC on Solaris 10 SPARC
    Add some ND_TTEST_/ND_TCHECK_ macros to simplify writing bounds checks
    Add a fn_printztn() which returns the number of bytes processed
    Add nd_init() and nd_cleanup() functions. Improve libsmi support
    Add CONTRIBUTING file
    Add a summary comment in all printers
    Compile with more warning options in devel mode if supported (-Wcast-qual, ...)
    Fix some leaks found by Valgrind/Memcheck
    Fix a bunch of de-constifications
    Squelch some Coverity warnings and some compiler warnings
    Update Coverity and Travis-CI setup
    Update Visual Studio files

    Frontend:
    Fix capsicum support to work with zerocopy buffers in bpf
    Try opening interfaces by name first, then by name-as-index
    Work around pcap_create() failures fetching time stamp type lists
    Fix a segmentation fault with 'tcpdump -J'
    Improve addrtostr6() bounds checking
    Add exit_tcpdump() function
    Don't drop CAP_SYS_CHROOT before chrooting
    Fixes issue where statistics not reported when -G and -W options used

    New printers supporting:
    Generic Protocol Extension for VXLAN (VXLAN-GPE)
    Home Networking Control Protocol (HNCP), RFCs 7787 and 7788
    Locator/Identifier Separation Protocol (LISP), type 3 and type 4 packets
    Marvell Extended Distributed Switch Architecture header (MEDSA)
    Network Service Header (NSH)
    REdis Serialization Protocol (RESP)

    Updated printers:
    802.11: Beginnings of 11ac radiotap support
    802.11: Check the Protected bit for management frames
    802.11: Do bounds checking on last_presentp before dereferencing it (Fix a heap overflow)
    802.11: Fix the radiotap printer to handle the special bits correctly
    802.11: If we have the MCS field, it's 11n
    802.11: Only print unknown frame type or subtype messages once
    802.11: Radiotap dBm values get printed as dB; Update a test output accordingly
    802.11: Source and destination addresses were backwards
    AH: Add a bounds check
    AH: Report to our caller that dissection failed if a bounds check fails
    AP1394: Print src > dst, not dst > src
    ARP: Don't assume the target hardware address is <= 6 octets long (Fix a heap overflow)
    ATALK: Add bounds and length checks (Fix heap overflows)
    ATM: Add some bounds checks (Fix a heap overflow)
    ATM: Fix an incorrect bounds check
    BFD: Update specification from draft to RFC 5880
    BFD: Update to print optional authentication field
    BGP: Add decoding of ADD-PATH capability
    BGP: Add support for the AIGP attribute (RFC7311)
    BGP: Print LARGE_COMMUNITY Path Attribute
    BGP: Update BGP numbers from IANA; Print minor values for FSM notification
    BOOTP: Add a bounds check
    Babel: Add decoder for source-specific extension
    CDP: Filter out non-printable characters
    CFM: Fixes to match the IEEE standard, additional bounds and length checks
    CSLIP: Add more bounds checks (Fix a heap overflow)
    ClassicalIPoATM: Add a bounds check on LLC+SNAP header (Fix a heap overflow)
    DHCP: Fix MUDURL and TZ options
    DHCPv6: Process MUDURL and TZ options
    DHCPv6: Update Status Codes with RFCs/IANA names
    DNS: Represent the "DNSSEC OK" bit as "DO" instead of "OK". Add a test case
    DTP: Improve packet integrity checks
    EGP: Fix bounds checks
    ESP: Don't use OpenSSL_add_all_algorithms() in OpenSSL 1.1.0 or later
    ESP: Handle OpenSSL 1.1.x
    Ethernet: Add some bounds checking before calling isoclns_print (Fix a heap overflow)
    Ethernet: Print the Length/Type field as length when needed
    FDDI: Fix -e output for FDDI
    FR: Add some packet-length checks and improve Q.933 printing (Fix heap overflows)
    GRE: Add some bounds checks (Fix heap overflows)
    Geneve: Fix error message with invalid option length; Update list option classes
    HNCP: Fix incorrect time interval format. Fix handling of IPv4 prefixes
    ICMP6: Fetch a 32-bit big-endian quantity with EXTRACT_32BITS()
    ICMP6: dagid is always an IPv6 address, not an opaque 128-bit string
    IGMP: Add a length check
    IP: Add a bounds check (Fix a heap overflow)
    IP: Check before fetching the protocol version (Fix a heap overflow)
    IP: Don't try to dissect if IP version != 4 (Fix a heap overflow)
    IP: Stop processing IPPROTO_ values once we hit IPPROTO_IPCOMP
    IPComp: Check whether we have the CPI before we fetch it (Fix a heap overflow)
    IPoFC: Fix -e output (IP-over-Fibre Channel)
    IPv6: Don't overwrite the destination IPv6 address for routing headers
    IPv6: Fix header printing
    IPv6: Stop processing IPPROTO_ values once we hit IPPROTO_IPCOMP
    ISAKMP: Clean up parsing of IKEv2 Security Associations
    ISOCLNS/IS-IS: Add support for Purge Originator Identifier (RFC6232) and test cases
    ISOCLNS/IS-IS: Don't overwrite packet data when checking the signature
    ISOCLNS/IS-IS: Filter out non-printable characters
    ISOCLNS/IS-IS: Fix segmentation faults
    ISOCLNS/IS-IS: Have signature_verify() do the copying and clearing
    ISOCLNS: Add some bounds checks
    Juniper: Make sure a Juniper header TLV isn't bigger than what's left in the packet (Fix a heap overflow)
    LLC/SNAP: With -e, print the LLC header before the SNAP header; without it, cut the SNAP header
    LLC: Add a bounds check (Fix a heap overflow)
    LLC: Clean up printing of LLC packets
    LLC: Fix the printing of RFC 948-style IP packets
    LLC: Skip the LLC and SNAP headers with -x for 802.11 and some other protocols
    LLDP: Implement IANA OUI and LLDP MUD option
    MPLS LSP ping: Update printing for RFC 4379, bug fixes, more bounds checks
    MPLS: "length" is now the *remaining* packet length
    MPLS: Add bounds and length checks (Fix a heap overflow)
    NFS: Add a test that makes unaligned accesses
    NFS: Don't assume the ONC RPC header is nicely aligned
    NFS: Don't overflow the Opaque_Handle buffer (Fix a segmentation fault)
    NFS: Don't run past the end of an NFSv3 file handle
    OLSR: Add a test to cover a HNA sgw case
    OLSR: Fix 'Advertised networks' count
    OLSR: Fix printing of smart-gateway HNAs in IPv4
    OSPF: Add a bounds check for the Hello packet options
    OSPF: Do more bounds checking
    OSPF: Fix a segmentation fault
    OSPF: Fix printing 'ospf_topology_values' default
    OTV: Add missing bounds checks
    PGM: Print the formatted IP address, not the raw binary address, as a string
    PIM: Add some bounds checking (Fix a heap overflow)
    PIMv2: Fix checksumming of Register messages
    PPI: Pass an adjusted struct pcap_pkthdr to the sub-printer
    PPP: Add some bounds checks (Fix a heap overflow)
    PPP: Report invalid PAP AACK/ANAK packets
    Q.933: Add a missing bounds check
    RADIUS: Add Value 13 "VLAN" to Tunnel-Type attribute
    RADIUS: Filter out non-printable characters
    RADIUS: Translate UDP/1700 as RADIUS
    RESP: Do better checking of RESP packets
    RPKI-RTR: Add a return value check for "fn_printn" call
    RPKI-RTR: Remove printing when truncated condition already detected
    RPL: Fix 'Consistency Check' control code
    RPL: Fix suboption print
    RSVP: An INTEGRITY object in a submessage covers only the submessage
    RSVP: Fix an infinite loop; Add bounds and length checks
    RSVP: Fix some if statements missing brackets
    RSVP: Have signature_verify() do the copying and clearing
    RTCP: Add some bounds checks
    RTP: Add some bounds checks, fix two segmentation faults
    SCTP: Do more bounds checking
    SFLOW: Fix bounds checking
    SLOW: Fix bugs, add checks
    SMB: Before fetching the flags2 field, make sure we have it
    SMB: Do bounds checks on NBNS resource types and resource data lengths
    SNMP: Clean up the "have libsmi but no modules loaded" case
    SNMP: Clean up the object abbreviation list and fix the code to match them
    SNMP: Do bounds checks when printing character and octet strings
    SNMP: Improve ASN.1 bounds checks
    SNMP: More bounds and length checks
    STP: Add a bunch of bounds checks, and fix some printing (Fix heap overflows)
    STP: Filter out non-printable characters
    TCP: Add bounds and length checks for packets with TCP option 20
    TCP: Correct TCP option Kind value for TCP Auth and add SCPS-TP
    TCP: Fix two bounds checks (Fix heap overflows)
    TCP: Make sure we have the data offset field before fetching it (Fix a heap overflow)
    TCP: Put TCP-AO option decoding right
    TFTP: Don't use strchr() to scan packet data (Fix a heap overflow)
    Telnet: Add some bounds checks
    TokenRing: Fix -e output
    UDLD: Fix an infinite loop
    UDP: Add a bounds check (Fix a heap overflow)
    UDP: Check against the packet length first
    UDP: Don't do the DDP-over-UDP heuristic check up front
    VAT: Add some bounds checks
    VTP: Add a test on Mgmt Domain Name length
    VTP: Add bounds checks and filter out non-printable characters
    VXLAN: Add a bound check and a test case
    ZeroMQ: Fix an infinite loop

  Tuesday April 14, 2015 guy@alum.mit.edu
  Summary for 4.8.0 tcpdump release
        Fix "-x" for Apple PKTAP and PPI packets

Bug: N/A
Test: "adb shell tcpdump"
Change-Id: I81df72cf1ebdbe61c5b6069d8532ae817570f23f
diff --git a/print-slow.c b/print-slow.c
index 2db3581..92d4a7b 100644
--- a/print-slow.c
+++ b/print-slow.c
@@ -18,24 +18,20 @@
  * Original code by Hannes Gredler (hannes@juniper.net)
  */
 
-#define NETDISSECT_REWORKED
+/* \summary: IEEE "slow protocols" (802.3ad/802.3ah) printer */
+
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 
-#include <tcpdump-stdinc.h>
+#include <netdissect-stdinc.h>
 
-#include "interface.h"
+#include "netdissect.h"
 #include "extract.h"
 #include "addrtoname.h"
 #include "ether.h"
 #include "oui.h"
 
-struct slow_common_header_t {
-    uint8_t proto_subtype;
-    uint8_t version;
-};
-
 #define	SLOW_PROTO_LACP                     1
 #define	SLOW_PROTO_MARKER                   2
 #define SLOW_PROTO_OAM                      3
@@ -185,21 +181,21 @@
     uint8_t length;
 };
 
-#define LACP_TLV_TERMINATOR     0x00
-#define LACP_TLV_ACTOR_INFO     0x01
-#define LACP_TLV_PARTNER_INFO   0x02
-#define LACP_TLV_COLLECTOR_INFO 0x03
+#define LACP_MARKER_TLV_TERMINATOR     0x00  /* same code for LACP and Marker */
 
-#define MARKER_TLV_TERMINATOR   0x00
-#define MARKER_TLV_MARKER_INFO  0x01
+#define LACP_TLV_ACTOR_INFO            0x01
+#define LACP_TLV_PARTNER_INFO          0x02
+#define LACP_TLV_COLLECTOR_INFO        0x03
+
+#define MARKER_TLV_MARKER_INFO         0x01
 
 static const struct tok slow_tlv_values[] = {
-    { (SLOW_PROTO_LACP << 8) + LACP_TLV_TERMINATOR, "Terminator"},
+    { (SLOW_PROTO_LACP << 8) + LACP_MARKER_TLV_TERMINATOR, "Terminator"},
     { (SLOW_PROTO_LACP << 8) + LACP_TLV_ACTOR_INFO, "Actor Information"},
     { (SLOW_PROTO_LACP << 8) + LACP_TLV_PARTNER_INFO, "Partner Information"},
     { (SLOW_PROTO_LACP << 8) + LACP_TLV_COLLECTOR_INFO, "Collector Information"},
 
-    { (SLOW_PROTO_MARKER << 8) + MARKER_TLV_TERMINATOR, "Terminator"},
+    { (SLOW_PROTO_MARKER << 8) + LACP_MARKER_TLV_TERMINATOR, "Terminator"},
     { (SLOW_PROTO_MARKER << 8) + MARKER_TLV_MARKER_INFO, "Marker Information"},
     { 0, NULL}
 };
@@ -242,35 +238,42 @@
     uint8_t pad[50];
 };
 
-static void slow_marker_lacp_print(netdissect_options *, register const u_char *, register u_int);
+static void slow_marker_lacp_print(netdissect_options *, register const u_char *, register u_int, u_int);
 static void slow_oam_print(netdissect_options *, register const u_char *, register u_int);
 
-const struct slow_common_header_t *slow_com_header;
-
 void
 slow_print(netdissect_options *ndo,
            register const u_char *pptr, register u_int len)
 {
     int print_version;
+    u_int subtype;
 
-    slow_com_header = (const struct slow_common_header_t *)pptr;
-    ND_TCHECK(*slow_com_header);
+    if (len < 1)
+        goto tooshort;
+    ND_TCHECK(*pptr);
+    subtype = *pptr;
 
     /*
      * Sanity checking of the header.
      */
-    switch (slow_com_header->proto_subtype) {
+    switch (subtype) {
     case SLOW_PROTO_LACP:
-        if (slow_com_header->version != LACP_VERSION) {
-            ND_PRINT((ndo, "LACP version %u packet not supported",slow_com_header->version));
+        if (len < 2)
+            goto tooshort;
+        ND_TCHECK(*(pptr+1));
+        if (*(pptr+1) != LACP_VERSION) {
+            ND_PRINT((ndo, "LACP version %u packet not supported", *(pptr+1)));
             return;
         }
         print_version = 1;
         break;
 
     case SLOW_PROTO_MARKER:
-        if (slow_com_header->version != MARKER_VERSION) {
-            ND_PRINT((ndo, "MARKER version %u packet not supported",slow_com_header->version));
+        if (len < 2)
+            goto tooshort;
+        ND_TCHECK(*(pptr+1));
+        if (*(pptr+1) != MARKER_VERSION) {
+            ND_PRINT((ndo, "MARKER version %u packet not supported", *(pptr+1)));
             return;
         }
         print_version = 1;
@@ -286,15 +289,15 @@
         break;
     }
 
-    if (print_version) {
+    if (print_version == 1) {
         ND_PRINT((ndo, "%sv%u, length %u",
-               tok2str(slow_proto_values, "unknown (%u)",slow_com_header->proto_subtype),
-               slow_com_header->version,
+               tok2str(slow_proto_values, "unknown (%u)", subtype),
+               *(pptr+1),
                len));
     } else {
         /* some slow protos don't have a version number in the header */
         ND_PRINT((ndo, "%s, length %u",
-               tok2str(slow_proto_values, "unknown (%u)",slow_com_header->proto_subtype),
+               tok2str(slow_proto_values, "unknown (%u)", subtype),
                len));
     }
 
@@ -307,32 +310,45 @@
     if (!ndo->ndo_vflag)
         return;
 
-    switch (slow_com_header->proto_subtype) {
+    switch (subtype) {
     default: /* should not happen */
         break;
 
     case SLOW_PROTO_OAM:
-        /* skip proto_subtype */
-        slow_oam_print(ndo, pptr+1, len-1);
+        /* skip subtype */
+        len -= 1;
+        pptr += 1;
+        slow_oam_print(ndo, pptr, len);
         break;
 
     case SLOW_PROTO_LACP:   /* LACP and MARKER share the same semantics */
     case SLOW_PROTO_MARKER:
-        /* skip slow_common_header */
-        len -= sizeof(const struct slow_common_header_t);
-        pptr += sizeof(const struct slow_common_header_t);
-        slow_marker_lacp_print(ndo, pptr, len);
+        /* skip subtype and version */
+        len -= 2;
+        pptr += 2;
+        slow_marker_lacp_print(ndo, pptr, len, subtype);
         break;
     }
     return;
 
+tooshort:
+    if (!ndo->ndo_vflag)
+        ND_PRINT((ndo, " (packet is too short)"));
+    else
+        ND_PRINT((ndo, "\n\t\t packet is too short"));
+    return;
+
 trunc:
-    ND_PRINT((ndo, "\n\t\t packet exceeded snapshot"));
+    if (!ndo->ndo_vflag)
+        ND_PRINT((ndo, " (packet exceeded snapshot)"));
+    else
+        ND_PRINT((ndo, "\n\t\t packet exceeded snapshot"));
 }
 
 static void
 slow_marker_lacp_print(netdissect_options *ndo,
-                       register const u_char *tptr, register u_int tlen)
+                       register const u_char *tptr, register u_int tlen,
+                       u_int proto_subtype)
 {
     const struct tlv_header_t *tlv_header;
     const u_char *tlv_tptr;
@@ -346,6 +362,9 @@
     } tlv_ptr;
 
     while(tlen>0) {
+        /* is the packet big enough to include the tlv header ? */
+        if (tlen < sizeof(struct tlv_header_t))
+            goto tooshort;
         /* did we capture enough for fully decoding the tlv header ? */
         ND_TCHECK2(*tptr, sizeof(struct tlv_header_t));
         tlv_header = (const struct tlv_header_t *)tptr;
@@ -354,30 +373,46 @@
         ND_PRINT((ndo, "\n\t%s TLV (0x%02x), length %u",
                tok2str(slow_tlv_values,
                        "Unknown",
-                       (slow_com_header->proto_subtype << 8) + tlv_header->type),
+                       (proto_subtype << 8) + tlv_header->type),
                tlv_header->type,
                tlv_len));
 
-        if ((tlv_len < sizeof(struct tlv_header_t) ||
-            tlv_len > tlen) &&
-            tlv_header->type != LACP_TLV_TERMINATOR &&
-            tlv_header->type != MARKER_TLV_TERMINATOR) {
-            ND_PRINT((ndo, "\n\t-----trailing data-----"));
-            print_unknown_data(ndo, tptr+sizeof(struct tlv_header_t), "\n\t  ", tlen);
+        if (tlv_header->type == LACP_MARKER_TLV_TERMINATOR) {
+            /*
+             * This TLV has a length of zero, and means there are no
+             * more TLVs to process.
+             */
             return;
         }
 
+        /* length includes the type and length fields */
+        if (tlv_len < sizeof(struct tlv_header_t)) {
+            ND_PRINT((ndo, "\n\t    ERROR: illegal length - should be >= %lu",
+                   (unsigned long) sizeof(struct tlv_header_t)));
+            return;
+        }
+
+        /* is the packet big enough to include the tlv ? */
+        if (tlen < tlv_len)
+            goto tooshort;
+        /* did we capture enough for fully decoding the tlv ? */
+        ND_TCHECK2(*tptr, tlv_len);
+
         tlv_tptr=tptr+sizeof(struct tlv_header_t);
         tlv_tlen=tlv_len-sizeof(struct tlv_header_t);
 
-        /* did we capture enough for fully decoding the tlv ? */
-        ND_TCHECK2(*tptr, tlv_len);
-
-        switch((slow_com_header->proto_subtype << 8) + tlv_header->type) {
+        switch((proto_subtype << 8) + tlv_header->type) {
 
             /* those two TLVs have the same structure -> fall through */
         case ((SLOW_PROTO_LACP << 8) + LACP_TLV_ACTOR_INFO):
         case ((SLOW_PROTO_LACP << 8) + LACP_TLV_PARTNER_INFO):
+            if (tlv_tlen !=
+                sizeof(struct lacp_tlv_actor_partner_info_t)) {
+                ND_PRINT((ndo, "\n\t    ERROR: illegal length - should be %lu",
+                       (unsigned long) (sizeof(struct tlv_header_t) + sizeof(struct lacp_tlv_actor_partner_info_t))));
+                goto badlength;
+            }
+
             tlv_ptr.lacp_tlv_actor_partner_info = (const struct lacp_tlv_actor_partner_info_t *)tlv_tptr;
 
             ND_PRINT((ndo, "\n\t  System %s, System Priority %u, Key %u" \
@@ -394,6 +429,13 @@
             break;
 
         case ((SLOW_PROTO_LACP << 8) + LACP_TLV_COLLECTOR_INFO):
+            if (tlv_tlen !=
+                sizeof(struct lacp_tlv_collector_info_t)) {
+                ND_PRINT((ndo, "\n\t    ERROR: illegal length - should be %lu",
+                       (unsigned long) (sizeof(struct tlv_header_t) + sizeof(struct lacp_tlv_collector_info_t))));
+                goto badlength;
+            }
+
             tlv_ptr.lacp_tlv_collector_info = (const struct lacp_tlv_collector_info_t *)tlv_tptr;
 
             ND_PRINT((ndo, "\n\t  Max Delay %u",
@@ -402,6 +444,13 @@
             break;
 
         case ((SLOW_PROTO_MARKER << 8) + MARKER_TLV_MARKER_INFO):
+            if (tlv_tlen !=
+                sizeof(struct marker_tlv_marker_info_t)) {
+                ND_PRINT((ndo, "\n\t    ERROR: illegal length - should be %lu",
+                       (unsigned long) (sizeof(struct tlv_header_t) + sizeof(struct marker_tlv_marker_info_t))));
+                goto badlength;
+            }
+
             tlv_ptr.marker_tlv_marker_info = (const struct marker_tlv_marker_info_t *)tlv_tptr;
 
             ND_PRINT((ndo, "\n\t  Request System %s, Request Port %u, Request Transaction ID 0x%08x",
@@ -411,29 +460,13 @@
 
             break;
 
-            /* those two TLVs have the same structure -> fall through */
-        case ((SLOW_PROTO_LACP << 8) + LACP_TLV_TERMINATOR):
-        case ((SLOW_PROTO_MARKER << 8) + LACP_TLV_TERMINATOR):
-            tlv_ptr.lacp_marker_tlv_terminator = (const struct lacp_marker_tlv_terminator_t *)tlv_tptr;
-            if (tlv_len == 0) {
-                tlv_len = sizeof(tlv_ptr.lacp_marker_tlv_terminator->pad) +
-                    sizeof(struct tlv_header_t);
-                /* tell the user that we modified the length field  */
-                if (ndo->ndo_vflag>1)
-                    ND_PRINT((ndo, " (=%u)", tlv_len));
-                /* we have messed around with the length field - now we need to check
-                 * again if there are enough bytes on the wire for the hexdump */
-                ND_TCHECK2(tlv_ptr.lacp_marker_tlv_terminator->pad[0],
-                        sizeof(tlv_ptr.lacp_marker_tlv_terminator->pad));
-            }
-
-            break;
-
         default:
             if (ndo->ndo_vflag <= 1)
                 print_unknown_data(ndo, tlv_tptr, "\n\t  ", tlv_tlen);
             break;
         }
+
+    badlength:
         /* do we want to see an additional hexdump ? */
         if (ndo->ndo_vflag > 1) {
             print_unknown_data(ndo, tptr+sizeof(struct tlv_header_t), "\n\t  ",
@@ -444,6 +477,11 @@
         tlen-=tlv_len;
     }
     return;
+
+tooshort:
+    ND_PRINT((ndo, "\n\t\t packet is too short"));
+    return;
+
 trunc:
     ND_PRINT((ndo, "\n\t\t packet exceeded snapshot"));
 }
@@ -477,7 +515,10 @@
         const struct slow_oam_loopbackctrl_t *slow_oam_loopbackctrl;
     } tlv;
 
-    ptr.slow_oam_common_header = (struct slow_oam_common_header_t *)tptr;
+    ptr.slow_oam_common_header = (const struct slow_oam_common_header_t *)tptr;
+    if (tlen < sizeof(*ptr.slow_oam_common_header))
+        goto tooshort;
+    ND_TCHECK(*ptr.slow_oam_common_header);
     tptr += sizeof(struct slow_oam_common_header_t);
     tlen -= sizeof(struct slow_oam_common_header_t);
 
@@ -491,20 +532,36 @@
     case SLOW_OAM_CODE_INFO:
         while (tlen > 0) {
             ptr.slow_oam_tlv_header = (const struct slow_oam_tlv_header_t *)tptr;
+            if (tlen < sizeof(*ptr.slow_oam_tlv_header))
+                goto tooshort;
+            ND_TCHECK(*ptr.slow_oam_tlv_header);
             ND_PRINT((ndo, "\n\t  %s Information Type (%u), length %u",
                    tok2str(slow_oam_info_type_values, "Reserved",
                            ptr.slow_oam_tlv_header->type),
                    ptr.slow_oam_tlv_header->type,
                    ptr.slow_oam_tlv_header->length));
 
+            if (ptr.slow_oam_tlv_header->type == SLOW_OAM_INFO_TYPE_END_OF_TLV) {
+                /*
+                 * As IEEE Std 802.3-2015 says for the End of TLV Marker,
+                 * "(the length and value of the Type 0x00 TLV can be ignored)".
+                 */
+                return;
+            }
+
+            /* length includes the type and length fields */
+            if (ptr.slow_oam_tlv_header->length < sizeof(struct slow_oam_tlv_header_t)) {
+                ND_PRINT((ndo, "\n\t    ERROR: illegal length - should be >= %u",
+                       (u_int)sizeof(struct slow_oam_tlv_header_t)));
+                return;
+            }
+
+            if (tlen < ptr.slow_oam_tlv_header->length)
+                goto tooshort;
+            ND_TCHECK2(*tptr, ptr.slow_oam_tlv_header->length);
+
             hexdump = FALSE;
             switch (ptr.slow_oam_tlv_header->type) {
-            case SLOW_OAM_INFO_TYPE_END_OF_TLV:
-                if (ptr.slow_oam_tlv_header->length != 0) {
-                    ND_PRINT((ndo, "\n\t    ERROR: illegal length - should be 0"));
-                }
-                return;
-
             case SLOW_OAM_INFO_TYPE_LOCAL: /* identical format - fall through */
             case SLOW_OAM_INFO_TYPE_REMOTE:
                 tlv.slow_oam_info = (const struct slow_oam_info_t *)tptr;
@@ -513,7 +570,8 @@
                     sizeof(struct slow_oam_info_t)) {
                     ND_PRINT((ndo, "\n\t    ERROR: illegal length - should be %lu",
                            (unsigned long) sizeof(struct slow_oam_info_t)));
-                    return;
+                    hexdump = TRUE;
+                    goto badlength_code_info;
                 }
 
                 ND_PRINT((ndo, "\n\t    OAM-Version %u, Revision %u",
@@ -546,11 +604,7 @@
                 break;
             }
 
-            /* infinite loop check */
-            if (!ptr.slow_oam_tlv_header->length) {
-                return;
-            }
-
+        badlength_code_info:
             /* do we also want to see a hex dump ? */
             if (ndo->ndo_vflag > 1 || hexdump==TRUE) {
                 print_unknown_data(ndo, tptr, "\n\t  ",
@@ -563,22 +617,47 @@
         break;
 
     case SLOW_OAM_CODE_EVENT_NOTIF:
+        /* Sequence number */
+        if (tlen < 2)
+            goto tooshort;
+        ND_TCHECK2(*tptr, 2);
+        ND_PRINT((ndo, "\n\t  Sequence Number %u", EXTRACT_16BITS(tptr)));
+        tlen -= 2;
+        tptr += 2;
+
+        /* TLVs */
         while (tlen > 0) {
             ptr.slow_oam_tlv_header = (const struct slow_oam_tlv_header_t *)tptr;
+            if (tlen < sizeof(*ptr.slow_oam_tlv_header))
+                goto tooshort;
+            ND_TCHECK(*ptr.slow_oam_tlv_header);
             ND_PRINT((ndo, "\n\t  %s Link Event Type (%u), length %u",
                    tok2str(slow_oam_link_event_values, "Reserved",
                            ptr.slow_oam_tlv_header->type),
                    ptr.slow_oam_tlv_header->type,
                    ptr.slow_oam_tlv_header->length));
 
+            if (ptr.slow_oam_tlv_header->type == SLOW_OAM_INFO_TYPE_END_OF_TLV) {
+                /*
+                 * As IEEE Std 802.3-2015 says for the End of TLV Marker,
+                 * "(the length and value of the Type 0x00 TLV can be ignored)".
+                 */
+                return;
+            }
+
+            /* length includes the type and length fields */
+            if (ptr.slow_oam_tlv_header->length < sizeof(struct slow_oam_tlv_header_t)) {
+                ND_PRINT((ndo, "\n\t    ERROR: illegal length - should be >= %u",
+                       (u_int)sizeof(struct slow_oam_tlv_header_t)));
+                return;
+            }
+
+            if (tlen < ptr.slow_oam_tlv_header->length)
+                goto tooshort;
+            ND_TCHECK2(*tptr, ptr.slow_oam_tlv_header->length);
+
             hexdump = FALSE;
             switch (ptr.slow_oam_tlv_header->type) {
-            case SLOW_OAM_LINK_EVENT_END_OF_TLV:
-                if (ptr.slow_oam_tlv_header->length != 0) {
-                    ND_PRINT((ndo, "\n\t    ERROR: illegal length - should be 0"));
-                }
-                return;
-
             case SLOW_OAM_LINK_EVENT_ERR_SYM_PER: /* identical format - fall through */
             case SLOW_OAM_LINK_EVENT_ERR_FRM:
             case SLOW_OAM_LINK_EVENT_ERR_FRM_PER:
@@ -589,7 +668,8 @@
                     sizeof(struct slow_oam_link_event_t)) {
                     ND_PRINT((ndo, "\n\t    ERROR: illegal length - should be %lu",
                            (unsigned long) sizeof(struct slow_oam_link_event_t)));
-                    return;
+                    hexdump = TRUE;
+                    goto badlength_event_notif;
                 }
 
                 ND_PRINT((ndo, "\n\t    Timestamp %u ms, Errored Window %" PRIu64
@@ -614,11 +694,7 @@
                 break;
             }
 
-            /* infinite loop check */
-            if (!ptr.slow_oam_tlv_header->length) {
-                return;
-            }
-
+        badlength_event_notif:
             /* do we also want to see a hex dump ? */
             if (ndo->ndo_vflag > 1 || hexdump==TRUE) {
                 print_unknown_data(ndo, tptr, "\n\t  ",
@@ -632,13 +708,16 @@
 
     case SLOW_OAM_CODE_LOOPBACK_CTRL:
         tlv.slow_oam_loopbackctrl = (const struct slow_oam_loopbackctrl_t *)tptr;
+        if (tlen < sizeof(*tlv.slow_oam_loopbackctrl))
+            goto tooshort;
+        ND_TCHECK(*tlv.slow_oam_loopbackctrl);
         ND_PRINT((ndo, "\n\t  Command %s (%u)",
                tok2str(slow_oam_loopbackctrl_cmd_values,
                        "Unknown",
                        tlv.slow_oam_loopbackctrl->command),
                tlv.slow_oam_loopbackctrl->command));
-               tptr ++;
-               tlen --;
+        tptr ++;
+        tlen --;
         break;
 
         /*
@@ -655,4 +734,11 @@
         break;
     }
     return;
+
+tooshort:
+    ND_PRINT((ndo, "\n\t\t packet is too short"));
+    return;
+
+trunc:
+    ND_PRINT((ndo, "\n\t\t packet exceeded snapshot"));
 }