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[tcpdump] / print-sflow.c
index cad42c129154998c913cc75df06fb0bca691d15b..dcaf28e8648c1dbd607a0a9ff7291b30eb19b6c1 100644 (file)
  * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  * FOR A PARTICULAR PURPOSE.
  *
- * The SFLOW protocol as per http://www.sflow.org/developers/specifications.php
- *
  * Original code by Carles Kishimoto <[email protected]>
  *
  * Expansion and refactoring by Rick Jones <[email protected]>
  */
 
-#define NETDISSECT_REWORKED
+/* \summary: sFlow protocol printer */
+
+/* specification: http://www.sflow.org/developers/specifications.php */
+
 #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"
 
  */
 
 struct sflow_datagram_t {
-    u_int8_t   version[4];
-    u_int8_t   ip_version[4];
-    u_int8_t   agent[4];
-    u_int8_t   agent_id[4];
-    u_int8_t   seqnum[4];
-    u_int8_t   uptime[4];
-    u_int8_t   samples[4];
+    uint8_t    version[4];
+    uint8_t    ip_version[4];
+    uint8_t    agent[4];
+    uint8_t    agent_id[4];
+    uint8_t    seqnum[4];
+    uint8_t    uptime[4];
+    uint8_t    samples[4];
 };
 
 struct sflow_sample_header {
-    u_int8_t   format[4];
-    u_int8_t   len[4];
+    uint8_t    format[4];
+    uint8_t    len[4];
 };
 
 #define                SFLOW_FLOW_SAMPLE               1
@@ -82,29 +83,29 @@ static const struct tok sflow_format_values[] = {
 };
 
 struct sflow_flow_sample_t {
-    u_int8_t    seqnum[4];
-    u_int8_t    typesource[4];
-    u_int8_t    rate[4];
-    u_int8_t    pool[4];
-    u_int8_t    drops[4];
-    u_int8_t    in_interface[4];
-    u_int8_t    out_interface[4];
-    u_int8_t    records[4];
+    uint8_t    seqnum[4];
+    uint8_t    typesource[4];
+    uint8_t    rate[4];
+    uint8_t    pool[4];
+    uint8_t    drops[4];
+    uint8_t    in_interface[4];
+    uint8_t    out_interface[4];
+    uint8_t    records[4];
 
 };
 
 struct sflow_expanded_flow_sample_t {
-    u_int8_t    seqnum[4];
-    u_int8_t    type[4];
-    u_int8_t    index[4];
-    u_int8_t    rate[4];
-    u_int8_t    pool[4];
-    u_int8_t    drops[4];
-    u_int8_t    in_interface_format[4];
-    u_int8_t    in_interface_value[4];
-    u_int8_t    out_interface_format[4];
-    u_int8_t    out_interface_value[4];
-    u_int8_t    records[4];
+    uint8_t    seqnum[4];
+    uint8_t    type[4];
+    uint8_t    index[4];
+    uint8_t    rate[4];
+    uint8_t    pool[4];
+    uint8_t    drops[4];
+    uint8_t    in_interface_format[4];
+    uint8_t    in_interface_value[4];
+    uint8_t    out_interface_format[4];
+    uint8_t    out_interface_value[4];
+    uint8_t    records[4];
 };
 
 #define        SFLOW_FLOW_RAW_PACKET                   1
@@ -156,47 +157,47 @@ static const struct tok sflow_flow_raw_protocol_values[] = {
 };
 
 struct sflow_expanded_flow_raw_t {
-    u_int8_t    protocol[4];
-    u_int8_t    length[4];
-    u_int8_t    stripped_bytes[4];
-    u_int8_t    header_size[4];
+    uint8_t    protocol[4];
+    uint8_t    length[4];
+    uint8_t    stripped_bytes[4];
+    uint8_t    header_size[4];
 };
 
 struct sflow_ethernet_frame_t {
-    u_int8_t length[4];
-    u_int8_t src_mac[8];
-    u_int8_t dst_mac[8];
-    u_int8_t type[4];
+    uint8_t length[4];
+    uint8_t src_mac[8];
+    uint8_t dst_mac[8];
+    uint8_t type[4];
 };
 
 struct sflow_extended_switch_data_t {
-    u_int8_t src_vlan[4];
-    u_int8_t src_pri[4];
-    u_int8_t dst_vlan[4];
-    u_int8_t dst_pri[4];
+    uint8_t src_vlan[4];
+    uint8_t src_pri[4];
+    uint8_t dst_vlan[4];
+    uint8_t dst_pri[4];
 };
 
 struct sflow_counter_record_t {
-    u_int8_t    format[4];
-    u_int8_t    length[4];
+    uint8_t    format[4];
+    uint8_t    length[4];
 };
 
 struct sflow_flow_record_t {
-    u_int8_t    format[4];
-    u_int8_t    length[4];
+    uint8_t    format[4];
+    uint8_t    length[4];
 };
 
 struct sflow_counter_sample_t {
-    u_int8_t    seqnum[4];
-    u_int8_t    typesource[4];
-    u_int8_t    records[4];
+    uint8_t    seqnum[4];
+    uint8_t    typesource[4];
+    uint8_t    records[4];
 };
 
 struct sflow_expanded_counter_sample_t {
-    u_int8_t    seqnum[4];
-    u_int8_t    type[4];
-    u_int8_t    index[4];
-    u_int8_t    records[4];
+    uint8_t    seqnum[4];
+    uint8_t    type[4];
+    uint8_t    index[4];
+    uint8_t    records[4];
 };
 
 #define         SFLOW_COUNTER_GENERIC           1
@@ -232,80 +233,80 @@ static const struct tok sflow_iface_direction_values[] = {
 };
 
 struct sflow_generic_counter_t {
-    u_int8_t    ifindex[4];
-    u_int8_t    iftype[4];
-    u_int8_t    ifspeed[8];
-    u_int8_t    ifdirection[4];
-    u_int8_t    ifstatus[4];
-    u_int8_t    ifinoctets[8];
-    u_int8_t    ifinunicastpkts[4];
-    u_int8_t    ifinmulticastpkts[4];
-    u_int8_t    ifinbroadcastpkts[4];
-    u_int8_t    ifindiscards[4];
-    u_int8_t    ifinerrors[4];
-    u_int8_t    ifinunkownprotos[4];
-    u_int8_t    ifoutoctets[8];
-    u_int8_t    ifoutunicastpkts[4];
-    u_int8_t    ifoutmulticastpkts[4];
-    u_int8_t    ifoutbroadcastpkts[4];
-    u_int8_t    ifoutdiscards[4];
-    u_int8_t    ifouterrors[4];
-    u_int8_t    ifpromiscmode[4];
+    uint8_t    ifindex[4];
+    uint8_t    iftype[4];
+    uint8_t    ifspeed[8];
+    uint8_t    ifdirection[4];
+    uint8_t    ifstatus[4];
+    uint8_t    ifinoctets[8];
+    uint8_t    ifinunicastpkts[4];
+    uint8_t    ifinmulticastpkts[4];
+    uint8_t    ifinbroadcastpkts[4];
+    uint8_t    ifindiscards[4];
+    uint8_t    ifinerrors[4];
+    uint8_t    ifinunkownprotos[4];
+    uint8_t    ifoutoctets[8];
+    uint8_t    ifoutunicastpkts[4];
+    uint8_t    ifoutmulticastpkts[4];
+    uint8_t    ifoutbroadcastpkts[4];
+    uint8_t    ifoutdiscards[4];
+    uint8_t    ifouterrors[4];
+    uint8_t    ifpromiscmode[4];
 };
 
 struct sflow_ethernet_counter_t {
-    u_int8_t    alignerrors[4];
-    u_int8_t    fcserrors[4];
-    u_int8_t    single_collision_frames[4];
-    u_int8_t    multiple_collision_frames[4];
-    u_int8_t    test_errors[4];
-    u_int8_t    deferred_transmissions[4];
-    u_int8_t    late_collisions[4];
-    u_int8_t    excessive_collisions[4];
-    u_int8_t    mac_transmit_errors[4];
-    u_int8_t    carrier_sense_errors[4];
-    u_int8_t    frame_too_longs[4];
-    u_int8_t    mac_receive_errors[4];
-    u_int8_t    symbol_errors[4];
+    uint8_t    alignerrors[4];
+    uint8_t    fcserrors[4];
+    uint8_t    single_collision_frames[4];
+    uint8_t    multiple_collision_frames[4];
+    uint8_t    test_errors[4];
+    uint8_t    deferred_transmissions[4];
+    uint8_t    late_collisions[4];
+    uint8_t    excessive_collisions[4];
+    uint8_t    mac_transmit_errors[4];
+    uint8_t    carrier_sense_errors[4];
+    uint8_t    frame_too_longs[4];
+    uint8_t    mac_receive_errors[4];
+    uint8_t    symbol_errors[4];
 };
 
 struct sflow_100basevg_counter_t {
-    u_int8_t    in_highpriority_frames[4];
-    u_int8_t    in_highpriority_octets[8];
-    u_int8_t    in_normpriority_frames[4];
-    u_int8_t    in_normpriority_octets[8];
-    u_int8_t    in_ipmerrors[4];
-    u_int8_t    in_oversized[4];
-    u_int8_t    in_data_errors[4];
-    u_int8_t    in_null_addressed_frames[4];
-    u_int8_t    out_highpriority_frames[4];
-    u_int8_t    out_highpriority_octets[8];
-    u_int8_t    transitioninto_frames[4];
-    u_int8_t    hc_in_highpriority_octets[8];
-    u_int8_t    hc_in_normpriority_octets[8];
-    u_int8_t    hc_out_highpriority_octets[8];
+    uint8_t    in_highpriority_frames[4];
+    uint8_t    in_highpriority_octets[8];
+    uint8_t    in_normpriority_frames[4];
+    uint8_t    in_normpriority_octets[8];
+    uint8_t    in_ipmerrors[4];
+    uint8_t    in_oversized[4];
+    uint8_t    in_data_errors[4];
+    uint8_t    in_null_addressed_frames[4];
+    uint8_t    out_highpriority_frames[4];
+    uint8_t    out_highpriority_octets[8];
+    uint8_t    transitioninto_frames[4];
+    uint8_t    hc_in_highpriority_octets[8];
+    uint8_t    hc_in_normpriority_octets[8];
+    uint8_t    hc_out_highpriority_octets[8];
 };
 
 struct sflow_vlan_counter_t {
-    u_int8_t    vlan_id[4];
-    u_int8_t    octets[8];
-    u_int8_t    unicast_pkt[4];
-    u_int8_t    multicast_pkt[4];
-    u_int8_t    broadcast_pkt[4];
-    u_int8_t    discards[4];
+    uint8_t    vlan_id[4];
+    uint8_t    octets[8];
+    uint8_t    unicast_pkt[4];
+    uint8_t    multicast_pkt[4];
+    uint8_t    broadcast_pkt[4];
+    uint8_t    discards[4];
 };
 
 static int
 print_sflow_counter_generic(netdissect_options *ndo,
-                            const u_char *pointer, u_int len) {
-
+                            const u_char *pointer, u_int len)
+{
     const struct sflow_generic_counter_t *sflow_gen_counter;
 
     if (len < sizeof(struct sflow_generic_counter_t))
        return 1;
 
-
     sflow_gen_counter = (const struct sflow_generic_counter_t *)pointer;
+    ND_TCHECK(*sflow_gen_counter);
     ND_PRINT((ndo, "\n\t      ifindex %u, iftype %u, ifspeed %" PRIu64 ", ifdirection %u (%s)",
           EXTRACT_32BITS(sflow_gen_counter->ifindex),
           EXTRACT_32BITS(sflow_gen_counter->iftype),
@@ -339,18 +340,22 @@ print_sflow_counter_generic(netdissect_options *ndo,
           EXTRACT_32BITS(sflow_gen_counter->ifpromiscmode)));
 
     return 0;
+
+trunc:
+    return 1;
 }
 
 static int
 print_sflow_counter_ethernet(netdissect_options *ndo,
-                             const u_char *pointer, u_int len){
-
+                             const u_char *pointer, u_int len)
+{
     const struct sflow_ethernet_counter_t *sflow_eth_counter;
 
     if (len < sizeof(struct sflow_ethernet_counter_t))
        return 1;
 
     sflow_eth_counter = (const struct sflow_ethernet_counter_t *)pointer;
+    ND_TCHECK(*sflow_eth_counter);
     ND_PRINT((ndo, "\n\t      align errors %u, fcs errors %u, single collision %u, multiple collision %u, test error %u",
           EXTRACT_32BITS(sflow_eth_counter->alignerrors),
           EXTRACT_32BITS(sflow_eth_counter->fcserrors),
@@ -369,25 +374,29 @@ print_sflow_counter_ethernet(netdissect_options *ndo,
           EXTRACT_32BITS(sflow_eth_counter->symbol_errors)));
 
     return 0;
+
+trunc:
+    return 1;
 }
 
 static int
 print_sflow_counter_token_ring(netdissect_options *ndo _U_,
-                               const u_char *pointer _U_, u_int len _U_) {
-
+                               const u_char *pointer _U_, u_int len _U_)
+{
     return 0;
 }
 
 static int
 print_sflow_counter_basevg(netdissect_options *ndo,
-                           const u_char *pointer, u_int len) {
-
+                           const u_char *pointer, u_int len)
+{
     const struct sflow_100basevg_counter_t *sflow_100basevg_counter;
 
     if (len < sizeof(struct sflow_100basevg_counter_t))
        return 1;
 
     sflow_100basevg_counter = (const struct sflow_100basevg_counter_t *)pointer;
+    ND_TCHECK(*sflow_100basevg_counter);
     ND_PRINT((ndo, "\n\t      in high prio frames %u, in high prio octets %" PRIu64,
           EXTRACT_32BITS(sflow_100basevg_counter->in_highpriority_frames),
           EXTRACT_64BITS(sflow_100basevg_counter->in_highpriority_octets)));
@@ -412,18 +421,22 @@ print_sflow_counter_basevg(netdissect_options *ndo,
           EXTRACT_64BITS(sflow_100basevg_counter->hc_out_highpriority_octets)));
 
     return 0;
+
+trunc:
+    return 1;
 }
 
 static int
 print_sflow_counter_vlan(netdissect_options *ndo,
-                         const u_char *pointer, u_int len) {
-
+                         const u_char *pointer, u_int len)
+{
     const struct sflow_vlan_counter_t *sflow_vlan_counter;
 
     if (len < sizeof(struct sflow_vlan_counter_t))
        return 1;
 
     sflow_vlan_counter = (const struct sflow_vlan_counter_t *)pointer;
+    ND_TCHECK(*sflow_vlan_counter);
     ND_PRINT((ndo, "\n\t      vlan_id %u, octets %" PRIu64
           ", unicast_pkt %u, multicast_pkt %u, broadcast_pkt %u, discards %u",
           EXTRACT_32BITS(sflow_vlan_counter->vlan_id),
@@ -434,26 +447,30 @@ print_sflow_counter_vlan(netdissect_options *ndo,
           EXTRACT_32BITS(sflow_vlan_counter->discards)));
 
     return 0;
+
+trunc:
+    return 1;
 }
 
 struct sflow_processor_counter_t {
-    u_int8_t five_sec_util[4];
-    u_int8_t one_min_util[4];
-    u_int8_t five_min_util[4];
-    u_int8_t total_memory[8];
-    u_int8_t free_memory[8];
+    uint8_t five_sec_util[4];
+    uint8_t one_min_util[4];
+    uint8_t five_min_util[4];
+    uint8_t total_memory[8];
+    uint8_t free_memory[8];
 };
 
 static int
 print_sflow_counter_processor(netdissect_options *ndo,
-                              const u_char *pointer, u_int len) {
-
+                              const u_char *pointer, u_int len)
+{
     const struct sflow_processor_counter_t *sflow_processor_counter;
 
     if (len < sizeof(struct sflow_processor_counter_t))
        return 1;
 
     sflow_processor_counter = (const struct sflow_processor_counter_t *)pointer;
+    ND_TCHECK(*sflow_processor_counter);
     ND_PRINT((ndo, "\n\t      5sec %u, 1min %u, 5min %u, total_mem %" PRIu64
           ", total_mem %" PRIu64,
           EXTRACT_32BITS(sflow_processor_counter->five_sec_util),
@@ -463,12 +480,15 @@ print_sflow_counter_processor(netdissect_options *ndo,
           EXTRACT_64BITS(sflow_processor_counter->free_memory)));
 
     return 0;
+
+trunc:
+    return 1;
 }
 
 static int
 sflow_print_counter_records(netdissect_options *ndo,
-                            const u_char *pointer, u_int len, u_int records) {
-
+                            const u_char *pointer, u_int len, u_int records)
+{
     u_int nrecords;
     const u_char *tptr;
     u_int tlen;
@@ -486,6 +506,7 @@ sflow_print_counter_records(netdissect_options *ndo,
        if (tlen < sizeof(struct sflow_counter_record_t))
            return 1;
        sflow_counter_record = (const struct sflow_counter_record_t *)tptr;
+       ND_TCHECK(*sflow_counter_record);
 
        enterprise = EXTRACT_32BITS(sflow_counter_record->format);
        counter_type = enterprise & 0x0FFF;
@@ -541,24 +562,26 @@ sflow_print_counter_records(netdissect_options *ndo,
     }
 
     return 0;
-}
 
+trunc:
+    return 1;
+}
 
 static int
 sflow_print_counter_sample(netdissect_options *ndo,
-                           const u_char *pointer, u_int len) {
-
+                           const u_char *pointer, u_int len)
+{
     const struct sflow_counter_sample_t *sflow_counter_sample;
     u_int           nrecords;
     u_int           typesource;
     u_int           type;
     u_int           index;
 
-
     if (len < sizeof(struct sflow_counter_sample_t))
        return 1;
 
     sflow_counter_sample = (const struct sflow_counter_sample_t *)pointer;
+    ND_TCHECK(*sflow_counter_sample);
 
     typesource = EXTRACT_32BITS(sflow_counter_sample->typesource);
     nrecords   = EXTRACT_32BITS(sflow_counter_sample->records);
@@ -575,12 +598,14 @@ sflow_print_counter_sample(netdissect_options *ndo,
                                       len - sizeof(struct sflow_counter_sample_t),
                                       nrecords);
 
+trunc:
+    return 1;
 }
 
 static int
 sflow_print_expanded_counter_sample(netdissect_options *ndo,
-                                    const u_char *pointer, u_int len) {
-
+                                    const u_char *pointer, u_int len)
+{
     const struct sflow_expanded_counter_sample_t *sflow_expanded_counter_sample;
     u_int           nrecords;
 
@@ -589,6 +614,7 @@ sflow_print_expanded_counter_sample(netdissect_options *ndo,
        return 1;
 
     sflow_expanded_counter_sample = (const struct sflow_expanded_counter_sample_t *)pointer;
+    ND_TCHECK(*sflow_expanded_counter_sample);
 
     nrecords = EXTRACT_32BITS(sflow_expanded_counter_sample->records);
 
@@ -602,18 +628,21 @@ sflow_print_expanded_counter_sample(netdissect_options *ndo,
                                       len - sizeof(struct sflow_expanded_counter_sample_t),
                                       nrecords);
 
+trunc:
+    return 1;
 }
 
 static int
 print_sflow_raw_packet(netdissect_options *ndo,
-                       const u_char *pointer, u_int len) {
-
+                       const u_char *pointer, u_int len)
+{
     const struct sflow_expanded_flow_raw_t *sflow_flow_raw;
 
     if (len < sizeof(struct sflow_expanded_flow_raw_t))
        return 1;
 
     sflow_flow_raw = (const struct sflow_expanded_flow_raw_t *)pointer;
+    ND_TCHECK(*sflow_flow_raw);
     ND_PRINT((ndo, "\n\t      protocol %s (%u), length %u, stripped bytes %u, header_size %u",
           tok2str(sflow_flow_raw_protocol_values,"Unknown",EXTRACT_32BITS(sflow_flow_raw->protocol)),
           EXTRACT_32BITS(sflow_flow_raw->protocol),
@@ -625,36 +654,44 @@ print_sflow_raw_packet(netdissect_options *ndo,
        assuming of course there is wnough data present to do so... */
 
     return 0;
+
+trunc:
+    return 1;
 }
 
 static int
 print_sflow_ethernet_frame(netdissect_options *ndo,
-                           const u_char *pointer, u_int len) {
-
+                           const u_char *pointer, u_int len)
+{
     const struct sflow_ethernet_frame_t *sflow_ethernet_frame;
 
     if (len < sizeof(struct sflow_ethernet_frame_t))
        return 1;
 
     sflow_ethernet_frame = (const struct sflow_ethernet_frame_t *)pointer;
+    ND_TCHECK(*sflow_ethernet_frame);
 
     ND_PRINT((ndo, "\n\t      frame len %u, type %u",
           EXTRACT_32BITS(sflow_ethernet_frame->length),
           EXTRACT_32BITS(sflow_ethernet_frame->type)));
 
     return 0;
+
+trunc:
+    return 1;
 }
 
 static int
 print_sflow_extended_switch_data(netdissect_options *ndo,
-                                 const u_char *pointer, u_int len) {
-
+                                 const u_char *pointer, u_int len)
+{
     const struct sflow_extended_switch_data_t *sflow_extended_sw_data;
 
     if (len < sizeof(struct sflow_extended_switch_data_t))
        return 1;
 
     sflow_extended_sw_data = (const struct sflow_extended_switch_data_t *)pointer;
+    ND_TCHECK(*sflow_extended_sw_data);
     ND_PRINT((ndo, "\n\t      src vlan %u, src pri %u, dst vlan %u, dst pri %u",
           EXTRACT_32BITS(sflow_extended_sw_data->src_vlan),
           EXTRACT_32BITS(sflow_extended_sw_data->src_pri),
@@ -662,12 +699,15 @@ print_sflow_extended_switch_data(netdissect_options *ndo,
           EXTRACT_32BITS(sflow_extended_sw_data->dst_pri)));
 
     return 0;
+
+trunc:
+    return 1;
 }
 
 static int
 sflow_print_flow_records(netdissect_options *ndo,
-                         const u_char *pointer, u_int len, u_int records) {
-
+                         const u_char *pointer, u_int len, u_int records)
+{
     u_int nrecords;
     const u_char *tptr;
     u_int tlen;
@@ -686,6 +726,7 @@ sflow_print_flow_records(netdissect_options *ndo,
            return 1;
 
        sflow_flow_record = (const struct sflow_flow_record_t *)tptr;
+       ND_TCHECK(*sflow_flow_record);
 
        /* so, the funky encoding means we cannot blythly mask-off
           bits, we must also check the enterprise. */
@@ -748,12 +789,15 @@ sflow_print_flow_records(netdissect_options *ndo,
     }
 
     return 0;
+
+trunc:
+    return 1;
 }
 
 static int
 sflow_print_flow_sample(netdissect_options *ndo,
-                        const u_char *pointer, u_int len) {
-
+                        const u_char *pointer, u_int len)
+{
     const struct sflow_flow_sample_t *sflow_flow_sample;
     u_int          nrecords;
     u_int          typesource;
@@ -763,7 +807,8 @@ sflow_print_flow_sample(netdissect_options *ndo,
     if (len < sizeof(struct sflow_flow_sample_t))
        return 1;
 
-    sflow_flow_sample = (struct sflow_flow_sample_t *)pointer;
+    sflow_flow_sample = (const struct sflow_flow_sample_t *)pointer;
+    ND_TCHECK(*sflow_flow_sample);
 
     typesource = EXTRACT_32BITS(sflow_flow_sample->typesource);
     nrecords = EXTRACT_32BITS(sflow_flow_sample->records);
@@ -785,12 +830,14 @@ sflow_print_flow_sample(netdissect_options *ndo,
                                    len - sizeof(struct sflow_flow_sample_t),
                                    nrecords);
 
+trunc:
+    return 1;
 }
 
 static int
 sflow_print_expanded_flow_sample(netdissect_options *ndo,
-                                 const u_char *pointer, u_int len) {
-
+                                 const u_char *pointer, u_int len)
+{
     const struct sflow_expanded_flow_sample_t *sflow_expanded_flow_sample;
     u_int nrecords;
 
@@ -798,6 +845,7 @@ sflow_print_expanded_flow_sample(netdissect_options *ndo,
        return 1;
 
     sflow_expanded_flow_sample = (const struct sflow_expanded_flow_sample_t *)pointer;
+    ND_TCHECK(*sflow_expanded_flow_sample);
 
     nrecords = EXTRACT_32BITS(sflow_expanded_flow_sample->records);
 
@@ -814,24 +862,33 @@ sflow_print_expanded_flow_sample(netdissect_options *ndo,
                                    len - sizeof(struct sflow_expanded_flow_sample_t),
                                    nrecords);
 
+trunc:
+    return 1;
 }
 
 void
 sflow_print(netdissect_options *ndo,
-            const u_char *pptr, u_int len) {
-
+            const u_char *pptr, u_int len)
+{
     const struct sflow_datagram_t *sflow_datagram;
     const struct sflow_sample_header *sflow_sample;
 
     const u_char *tptr;
     u_int tlen;
-    u_int32_t sflow_sample_type, sflow_sample_len;
-    u_int32_t nsamples;
-
+    uint32_t sflow_sample_type, sflow_sample_len;
+    uint32_t nsamples;
 
     tptr = pptr;
     tlen = len;
     sflow_datagram = (const struct sflow_datagram_t *)pptr;
+    if (len < sizeof(struct sflow_datagram_t)) {
+        ND_TCHECK(sflow_datagram->version);
+        ND_PRINT((ndo, "sFlowv%u", EXTRACT_32BITS(sflow_datagram->version)));
+        ND_PRINT((ndo, " [length %u < %zu]",
+                  len, sizeof(struct sflow_datagram_t)));
+        ND_PRINT((ndo, " (invalid)"));
+        return;
+    }
     ND_TCHECK(*sflow_datagram);
 
     /*
@@ -867,6 +924,8 @@ sflow_print(netdissect_options *ndo,
 
     /* skip Common header */
     tptr += sizeof(const struct sflow_datagram_t);
+
+    if(tlen <= sizeof(const struct sflow_datagram_t)) goto trunc;
     tlen -= sizeof(const struct sflow_datagram_t);
 
     while (nsamples > 0 && tlen > 0) {