Implemented DHCP field 55 decode

2 files changed, 22 insertions, 7 deletions

diff --git a/src/include/ndpi_typedefs.h b/src/include/ndpi_typedefs.h
index 71e2ba560..55c056bfb 100644
--- a/src/include/ndpi_typedefs.h
+++ b/src/include/ndpi_typedefs.h
@@ -908,6 +908,8 @@ struct ndpi_detection_module_struct {
     direction_detect_disable:1; /* disable internal detection of packet direction */
 };
 
+#define dhcp_fingerprint host_server_name
+
 struct ndpi_flow_struct {
   u_int16_t detected_protocol_stack[NDPI_PROTOCOL_SIZE];
 #ifndef WIN32
@@ -946,7 +948,7 @@ struct ndpi_flow_struct {
   */
   struct ndpi_id_struct *server_id;
   /* HTTP host or DNS query */
-  u_char host_server_name[256];
+  u_char host_server_name[256]; /* Shared with dhcp_fingerprint */
   /* Via HTTP User-Agent */
   u_char detected_os[32];
   /* Via HTTP X-Forwarded-For */
diff --git a/src/lib/protocols/dhcp.c b/src/lib/protocols/dhcp.c
index 38711c911..ee5b12834 100644
--- a/src/lib/protocols/dhcp.c
+++ b/src/lib/protocols/dhcp.c
@@ -78,24 +78,36 @@ void ndpi_search_dhcp_udp(struct ndpi_detection_module_struct *ndpi_struct, stru
 
       while(i < DHCP_VEND_LEN) {
 	u_int8_t id  = dhcp->options[i];
-	if(id == 0xFF) break;
+
+	if(id == 0xFF)
+	  break;
 	else {
 	  u_int8_t len = dhcp->options[i+1];
-	  
+
 	  if(len == 0) break;
-	  
+
 #ifdef DHCP_DEBUG
 	  printf("[DHCP] Id=%d [len=%d]\n", id, len);
 #endif
-	  
+
 	  if(id == 53 /* DHCP Message Type */) {
 	    u_int8_t msg_type = dhcp->options[i+2];
-	    
+
 	    if(msg_type <= 8) foundValidMsgType = 1;
+	  } else if(id == 55 /* Parameter Request List / Fingerprint */) {
+	    u_int idx, offset = 0,
+	      hex_len = ndpi_min(len * 2, sizeof(flow->dhcp_fingerprint));
+
+	    for(idx=0; idx<len; idx++) {
+	      snprintf((char*)&flow->dhcp_fingerprint[offset],
+		       sizeof(flow->dhcp_fingerprint)-offset-1,
+		       "%02X",  dhcp->options[i+2+idx] & 0xFF);
+	      offset += 2;
+	    }
 	  } else if(id == 12 /* Host Name */) {
 	    char *name = (char*)&dhcp->options[i+2];
 	    int j = 0;
-	    
+
 #ifdef DHCP_DEBUG
 	    printf("[DHCP] ");
 	    while(j < len) { printf("%c", name[j]); j++; }
@@ -105,6 +117,7 @@ void ndpi_search_dhcp_udp(struct ndpi_detection_module_struct *ndpi_struct, stru
 	    strncpy((char*)flow->host_server_name, name, j);
 	    flow->host_server_name[j] = '\0';
 	  }
+
 	  i += len + 2;
 	}
       }