bugfix: calculate L2TPv2 offset

3 files changed, 32 insertions, 29 deletions

diff --git a/src/packet/packet.cpp b/src/packet/packet.cpp
index ccadc9b..5954e7e 100644
--- a/src/packet/packet.cpp
+++ b/src/packet/packet.cpp
@@ -728,7 +728,21 @@ static inline uint16_t get_l2tpv2_hdr_len(const char *data, uint16_t len)
             {
                 return 0;
             }
-            return ntohs(*((uint16_t *)(data + skip_len)));
+            uint16_t offset = ntohs(*((uint16_t *)(data + skip_len)));
+            if (offset == 0)
+            {
+                return skip_len + 2;
+            }
+
+            // invalid offset
+            if (offset > len)
+            {
+                return 0;
+            }
+            else
+            {
+                return offset;
+            }
         }
         else
         {
diff --git a/test/packet_parser/cmp_layers.sh b/test/packet_parser/cmp_layers.sh
index 791c203..fd886de 100644
--- a/test/packet_parser/cmp_layers.sh
+++ b/test/packet_parser/cmp_layers.sh
@@ -15,7 +15,7 @@ fi
 # remove l7 protocol fields
 function replace() {
     file=$1
-    array=(":data" ":ntp" ":rip" ":isakmp" ":esp" ":udpencap" ":sip" ":sdp" ":rtcp" ":rtp" ":ssh" ":dns" ":ssl" ":gquic" ":http-text-lines" ":http" ":msmms" ":bfd" ":ftp-data-text-lines" ":ftp" ":ssdp" ":mdns" ":radius" ":pop" ":smtp" ":rtmpt" ":bittorrent" ":oicq" ":json" ":media" ":x11" ":telnet" ":nbss:smb" ":memcache" ":rtspi" ":rdt" ":rtsp" ":nbns" ":nbdgm:smb:browser" ":lcp" ":chap" ":ipcp" ":comp_data" ":ccp" ":snmp" ":socks" ":bgp" ":eigrp" ":bootp" ":xml" ":echo" ":vssmonitoring" ":mndp" ":websocket-text-lines" ":websocket" ":image-jfif" ":png" ":pkix1implicit" ":x509sat" ":x509ce" ":pkix1explicit" ":llmnr")
+    array=(":data" ":ntp" ":rip" ":isakmp" ":esp" ":udpencap" ":sip" ":sdp" ":rtcp" ":rtp" ":ssh" ":dns" ":ssl" ":gquic" ":http-text-lines" ":http" ":msmms" ":bfd" ":ftp-data-text-lines" ":ftp" ":ssdp" ":mdns" ":radius" ":pop" ":smtp" ":rtmpt" ":bittorrent" ":oicq" ":json" ":media" ":x11" ":telnet" ":nbss:smb" ":memcache" ":rtspi" ":rdt" ":rtsp" ":nbns" ":nbdgm:smb:browser" ":lcp" ":chap" ":ipcp" ":comp_data" ":ccp" ":snmp" ":socks" ":bgp" ":eigrp" ":bootp" ":xml" ":echo" ":vssmonitoring" ":mndp" ":websocket-text-lines" ":websocket" ":image-jfif" ":png" ":pkix1implicit" ":x509sat" ":x509ce" ":pkix1explicit" ":llmnr" ":pkcs-1")
     for key in "${array[@]}"; do
         sed "s/$key//g" ${file} >.tmp.txt
         mv .tmp.txt ${file}
diff --git a/test/packet_parser/packet_parser.cpp b/test/packet_parser/packet_parser.cpp
index 2d00575..1f5de4f 100644
--- a/test/packet_parser/packet_parser.cpp
+++ b/test/packet_parser/packet_parser.cpp
@@ -15,34 +15,23 @@ static uint64_t number = 0;
 static int ipv6_proto_to_str(const struct packet_layer *ipv6_layer, char *buff, int size)
 {
     int used = snprintf(buff, size, "ipv6");
-    uint16_t skip_len = sizeof(struct ip6_hdr);
     uint8_t next_hdr = ipv6_hdr_get_next_header((const struct ip6_hdr *)ipv6_layer->hdr_ptr);
-    while (skip_len < ipv6_layer->hdr_len)
+    switch (next_hdr)
     {
-        if (next_hdr == IPPROTO_HOPOPTS)
-        {
-            used += snprintf(buff + used, size - used, ":ipv6.hopopt");
-        }
-        else if (next_hdr == IPPROTO_ROUTING)
-        {
-            used += snprintf(buff + used, size - used, ":ipv6.routing");
-        }
-        else if (next_hdr == IPPROTO_AH)
-        {
-            used += snprintf(buff + used, size - used, ":ipv6.ah");
-        }
-        else if (next_hdr == IPPROTO_DSTOPTS)
-        {
-            used += snprintf(buff + used, size - used, ":ipv6.dstopts");
-        }
-        else
-        {
-            break;
-        }
-
-        struct ip6_ext *ext = (struct ip6_ext *)ipv6_layer->hdr_ptr + skip_len;
-        skip_len += ext->ip6e_len * 8 + 8;
-        next_hdr = ext->ip6e_nxt;
+    case IPPROTO_HOPOPTS:
+        used += snprintf(buff + used, size - used, ":ipv6.hopopt");
+        break;
+    case IPPROTO_ROUTING:
+        used += snprintf(buff + used, size - used, ":ipv6.routing");
+        break;
+    case IPPROTO_AH:
+        used += snprintf(buff + used, size - used, ":ipv6.ah");
+        break;
+    case IPPROTO_DSTOPTS:
+        used += snprintf(buff + used, size - used, ":ipv6.dstopts");
+        break;
+    default:
+        break;
     }
 
     return used;
@@ -73,7 +62,7 @@ static int packet_proto_to_str(const struct packet *pkt, char *buff, int size)
             used += snprintf(buff + used, size - used, "vlan:ethertype");
             break;
         case LAYER_TYPE_PPPOE:
-            used += snprintf(buff + used, size - used, "pppoe");
+            used += snprintf(buff + used, size - used, "pppoes:ppp");
             break;
         case LAYER_TYPE_MPLS:
             used += snprintf(buff + used, size - used, "mpls");