5 files changed, 346 insertions, 0 deletions
diff --git a/src/include/ndpi_protocol_ids.h b/src/include/ndpi_protocol_ids.h
index 099127dff..69e957452 100644
--- a/src/include/ndpi_protocol_ids.h
+++ b/src/include/ndpi_protocol_ids.h
@@ -375,6 +375,7 @@ typedef enum {
   NDPI_PROTOCOL_PROTONVPN             = 344,
   NDPI_PROTOCOL_APACHE_THRIFT         = 345,
   NDPI_PROTOCOL_ROBLOX                = 346,
+  NDPI_PROTOCOL_SERVICE_LOCATION      = 347,
 
 #ifdef CUSTOM_NDPI_PROTOCOLS
 #include "../../../nDPI-custom/custom_ndpi_protocol_ids.h"
diff --git a/src/include/ndpi_protocols.h b/src/include/ndpi_protocols.h
index 6a73f152b..4dae42c48 100644
--- a/src/include/ndpi_protocols.h
+++ b/src/include/ndpi_protocols.h
@@ -243,6 +243,7 @@ void init_oicq_dissector(struct ndpi_detection_module_struct *ndpi_struct, u_int
 void init_epicgames_dissector(struct ndpi_detection_module_struct *ndpi_struct, u_int32_t *id);
 void init_bitcoin_dissector(struct ndpi_detection_module_struct *ndpi_struct, u_int32_t *id);
 void init_apache_thrift_dissector(struct ndpi_detection_module_struct *ndpi_struct, u_int32_t *id);
+void init_slp_dissector(struct ndpi_detection_module_struct *ndpi_struct, u_int32_t *id);
 
 /* ndpi_main.c */
 extern u_int32_t ndpi_ip_port_hash_funct(u_int32_t ip, u_int16_t port);
diff --git a/src/include/ndpi_typedefs.h b/src/include/ndpi_typedefs.h
index 15415526c..708322a5d 100644
--- a/src/include/ndpi_typedefs.h
+++ b/src/include/ndpi_typedefs.h
@@ -1608,6 +1608,11 @@ struct ndpi_flow_struct {
       u_int8_t message_type;
       char method[64];
     } thrift;
+
+    struct {
+      u_int8_t url_count;
+      char url[4][48];
+    } slp;
   } protos;
 
   /*** ALL protocol specific 64 bit variables here ***/
diff --git a/src/lib/ndpi_main.c b/src/lib/ndpi_main.c
index 9b955e7a9..9d31564a7 100644
--- a/src/lib/ndpi_main.c
+++ b/src/lib/ndpi_main.c
@@ -2147,6 +2147,10 @@ static void ndpi_init_protocol_defaults(struct ndpi_detection_module_struct *ndp
 			  "Roblox", NDPI_PROTOCOL_CATEGORY_GAME,
 			  ndpi_build_default_ports(ports_a, 0, 0, 0, 0, 0) /* TCP */,
 			  ndpi_build_default_ports(ports_b, 0, 0, 0, 0, 0) /* UDP */);
+  ndpi_set_proto_defaults(ndpi_str, 1 /* cleartext */, 0 /* nw proto */, NDPI_PROTOCOL_ACCEPTABLE, NDPI_PROTOCOL_SERVICE_LOCATION,
+			  "Service_Location_Protocol", NDPI_PROTOCOL_CATEGORY_RPC,
+			  ndpi_build_default_ports(ports_a, 427, 0, 0, 0, 0) /* TCP */,
+			  ndpi_build_default_ports(ports_b, 427, 0, 0, 0, 0) /* UDP */);
 
 
 #ifdef CUSTOM_NDPI_PROTOCOLS
@@ -5049,6 +5053,9 @@ static int ndpi_callback_init(struct ndpi_detection_module_struct *ndpi_str) {
   /* Apache Thrift */
   init_apache_thrift_dissector(ndpi_str, &a);
 
+  /* Service Location Protocol */
+  init_slp_dissector(ndpi_str, &a);
+
 #ifdef CUSTOM_NDPI_PROTOCOLS
 #include "../../../nDPI-custom/custom_ndpi_main_init.c"
 #endif
diff --git a/src/lib/protocols/slp.c b/src/lib/protocols/slp.c
new file mode 100644
index 000000000..bf8f31d6b
--- /dev/null
+++ b/src/lib/protocols/slp.c
@@ -0,0 +1,332 @@
+/*
+ * slp.c
+ *
+ * Copyright (C) 2023 - ntop.org
+ *
+ * This file is part of nDPI, an open source deep packet inspection
+ * library based on the OpenDPI and PACE technology by ipoque GmbH
+ *
+ * nDPI is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * nDPI is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with nDPI.  If not, see <http://www.gnu.org/licenses/>.
+ * 
+ */
+
+#include "ndpi_protocol_ids.h"
+
+#define NDPI_CURRENT_PROTO NDPI_PROTOCOL_SERVICE_LOCATION
+
+#include "ndpi_api.h"
+
+PACK_ON
+struct slp_hdr_v1 {
+  uint8_t version;
+  uint8_t function;
+  uint16_t length;
+  uint8_t flags;
+  uint8_t dialect;
+  uint16_t lang_code;
+  uint16_t encoding;
+  uint16_t xid;
+} PACK_OFF;
+
+PACK_ON
+struct slp_hdr_v2 {
+  uint8_t version;
+  uint8_t function_id;
+  PACK_ON struct {
+    uint16_t high;
+    uint8_t low;
+  } PACK_OFF length;
+  uint16_t flags;
+  PACK_ON struct {
+    uint16_t high;
+    uint8_t low;
+  } PACK_OFF next_ext_offset;
+  uint16_t xid;
+  uint16_t lang_tag_length;
+  uint16_t lang_tag;
+} PACK_OFF;
+
+PACK_ON
+struct slp_url_entry {
+  uint8_t reserved;
+  uint16_t lifetime;
+  uint16_t length;
+  // char URL[length]
+  // uint8_t num_auths;
+} PACK_OFF;
+
+enum function_id {
+  FID_UNKNOWN     = 0,
+  FID_SrvRqst     = 1,
+  FID_SrvRply     = 2,
+  FID_SrvReg      = 3,
+  FID_SrvDeReg    = 4,
+  FID_SrvAck      = 5,
+  FID_AttrRqst    = 6,
+  FID_AttrRply    = 7,
+  FID_DAAdvert    = 8,
+  FID_SrvTypeRqst = 9,
+  FID_SrvTypeRply = 10,
+  FID_MAX_v1      = 11,
+  FID_SAAdvert    = 11, // Not available in version 1
+  FID_MAX
+};
+
+static void ndpi_int_slp_add_connection(struct ndpi_detection_module_struct *ndpi_struct,
+                                        struct ndpi_flow_struct *flow)
+{
+  NDPI_LOG_INFO(ndpi_struct, "found Service Location Protocol\n");
+
+  ndpi_set_detected_protocol(ndpi_struct, flow,
+                             NDPI_PROTOCOL_SERVICE_LOCATION, NDPI_PROTOCOL_UNKNOWN,
+                             NDPI_CONFIDENCE_DPI);
+}
+
+static int slp_check_packet_length(struct ndpi_detection_module_struct *ndpi_struct,
+                                   struct ndpi_flow_struct *flow,
+                                   unsigned int packet_length)
+{
+  struct ndpi_packet_struct const * const packet = &ndpi_struct->packet;
+
+  if (packet->payload_packet_len != packet_length) {
+    NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+    return 1;
+  }
+
+  return 0;
+}
+
+static int slp_check_fid(struct ndpi_detection_module_struct *ndpi_struct,
+                         struct ndpi_flow_struct *flow,
+                         enum function_id fid, uint8_t slp_version)
+{
+  if (fid <= FID_UNKNOWN) {
+    NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+    return 1;
+  }
+
+  switch (slp_version) {
+    case 0x01:
+      if (fid >= FID_MAX_v1) {
+        NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+        return 1;
+      }
+      break;
+    case 0x02:
+      if (fid >= FID_MAX) {
+        NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+        return 1;
+      }
+      break;
+    default:
+      NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+      return 1;
+  }
+
+  return 0;
+}
+
+static int slp_dissect_url_entries(struct ndpi_detection_module_struct *ndpi_struct,
+                                   struct ndpi_flow_struct *flow,
+                                   uint16_t url_entries_offset)
+{
+  struct ndpi_packet_struct const * const packet = &ndpi_struct->packet;
+  struct slp_url_entry const *url_entry;
+  uint16_t url_entries_count;
+
+  if (packet->payload_packet_len <= url_entries_offset + sizeof(uint16_t)) {
+    return 1;
+  }
+  url_entries_count = ntohs(*(uint16_t *)&packet->payload[url_entries_offset]);
+  url_entries_offset += sizeof(uint16_t);
+
+  for (size_t i = 0; i < ndpi_min(url_entries_count, NDPI_ARRAY_LENGTH(flow->protos.slp.url)); ++i) {
+    if (packet->payload_packet_len < url_entries_offset + sizeof(*url_entry)) {
+      return 1;
+    }
+    url_entry = (struct slp_url_entry *)&packet->payload[url_entries_offset];
+    url_entries_offset += sizeof(*url_entry);
+    uint16_t url_length = ntohs(url_entry->length);
+
+    if (packet->payload_packet_len < url_entries_offset + url_length + 1 /* num_auths */) {
+      return 1;
+    }
+    url_entries_offset += url_length;
+
+    flow->protos.slp.url_count++;
+    char const * const url = (char *)&url_entry->length + sizeof(url_entry->length);
+    strncpy(flow->protos.slp.url[i], url, ndpi_min(url_length, NDPI_ARRAY_LENGTH(flow->protos.slp.url[i]) - 1));
+    flow->protos.slp.url[i][NDPI_ARRAY_LENGTH(flow->protos.slp.url[i]) - 1] = '\0';
+
+    // handle Authentication Blocks
+    uint8_t num_auths = packet->payload[url_entries_offset++];
+    for (size_t j = 0; j < num_auths; ++j) {
+      size_t auth_block_offset = url_entries_offset + 2;
+      if (packet->payload_packet_len <= auth_block_offset + 2) {
+        return 1;
+      }
+      uint16_t auth_block_length = ntohs(*(uint16_t *)&packet->payload[auth_block_offset]);
+      if (packet->payload_packet_len < auth_block_offset + auth_block_length) {
+        return 1;
+      }
+      url_entries_offset += auth_block_length;
+    }
+  }
+
+  return flow->protos.slp.url_count == 0;
+}
+
+static void ndpi_search_slp_v1(struct ndpi_detection_module_struct *ndpi_struct,
+                               struct ndpi_flow_struct *flow)
+{
+  struct ndpi_packet_struct const * const packet = &ndpi_struct->packet;
+  struct slp_hdr_v1 const * const hdr = (struct slp_hdr_v1 *)&packet->payload[0];
+
+  NDPI_LOG_DBG(ndpi_struct, "search Service Location Protocol v1\n");
+
+  if (packet->payload_packet_len < sizeof(*hdr)) {
+    NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+    return;
+  }
+
+  const unsigned int packet_length = ntohs(hdr->length);
+  if (slp_check_packet_length(ndpi_struct, flow, packet_length) != 0)
+    return;
+
+  if (slp_check_fid(ndpi_struct, flow, hdr->function, hdr->version) != 0)
+    return;
+
+  ndpi_int_slp_add_connection(ndpi_struct, flow);
+}
+
+static int ndpi_search_slp_v2(struct ndpi_detection_module_struct *ndpi_struct,
+                              struct ndpi_flow_struct *flow)
+{
+  struct ndpi_packet_struct const * const packet = &ndpi_struct->packet;
+  struct slp_hdr_v2 const * const hdr = (struct slp_hdr_v2 *)&packet->payload[0];
+
+  NDPI_LOG_DBG(ndpi_struct, "search Service Location Protocol v2\n");
+
+  if (packet->payload_packet_len < sizeof(*hdr)) {
+    NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+    return 1;
+  }
+
+  const unsigned int packet_length = (ntohs(hdr->length.high) << 8) | hdr->length.low;
+  if (slp_check_packet_length(ndpi_struct, flow, packet_length) != 0)
+    return 1;
+
+  if (slp_check_fid(ndpi_struct, flow, hdr->function_id, hdr->version) != 0)
+    return 1;
+
+  ndpi_int_slp_add_connection(ndpi_struct, flow);
+  return 0;
+}
+
+static void ndpi_dissect_slp_v2(struct ndpi_detection_module_struct *ndpi_struct,
+                                struct ndpi_flow_struct *flow)
+{
+  struct ndpi_packet_struct const * const packet = &ndpi_struct->packet;
+  struct slp_hdr_v2 const * const hdr = (struct slp_hdr_v2 *)&packet->payload[0];
+  int url_offset = -1; // Can be either an offset to <URL String> or <URL Entry>
+  int url_length_offset = -1; // length of <URL String>
+  int url_entry_count_offset = -1; // amount of <URL Entry>'s
+
+  switch (hdr->function_id) {
+    case FID_SrvRply:
+      url_entry_count_offset = 2;
+      url_offset = 4;
+      break;
+    case FID_SrvReg:
+      url_offset = 3; // contains always 1 <URL Entry>
+      break;
+    case FID_DAAdvert:
+      url_length_offset = 6;
+      url_offset = 8;
+      break;
+    case FID_SAAdvert:
+      url_length_offset = 0;
+      url_offset = 2;
+      break;
+    case FID_AttrRqst:
+      url_length_offset = 4;
+      url_offset = 6;
+      break;
+    case FID_SrvDeReg:
+      url_offset = 7; // contains always 1 <URL Entry>
+      break;
+  }
+
+  if (url_offset >= 0) {
+    uint16_t url_length_or_count = 0;
+
+    if (url_length_offset > 0 && packet->payload_packet_len > sizeof(*hdr) + url_length_offset + 2) {
+      // <URL String>
+      url_length_or_count = ntohs(*(uint16_t *)&packet->payload[sizeof(*hdr) + url_length_offset]);
+      if (packet->payload_packet_len > sizeof(*hdr) + url_offset + 2 + url_length_or_count) {
+        size_t len = ndpi_min(sizeof(flow->protos.slp.url[0]) - 1, url_length_or_count);
+        flow->protos.slp.url_count = 1;
+        strncpy(flow->protos.slp.url[0], (char *)&packet->payload[sizeof(*hdr) + url_offset + 2], len);
+        flow->protos.slp.url[0][len] = 0;
+      }
+    } else if (url_entry_count_offset > 0 && packet->payload_packet_len > sizeof(*hdr) + url_entry_count_offset + 2) {
+      if (slp_dissect_url_entries(ndpi_struct, flow, sizeof(*hdr) + url_entry_count_offset) != 0) {
+        ndpi_set_risk(ndpi_struct, flow, NDPI_MALFORMED_PACKET, "Invalid URL entries");
+      }
+    } else if (packet->payload_packet_len > sizeof(*hdr) + url_offset + 2) {
+      url_length_or_count = ntohs(*(uint16_t *)&packet->payload[sizeof(*hdr) + url_offset]); // FID_SrvReg or FID_SrvDeReg
+      if (packet->payload_packet_len > sizeof(*hdr) + url_offset + 2 + url_length_or_count) {
+        size_t len = ndpi_min(sizeof(flow->protos.slp.url[0]) - 1, url_length_or_count);
+        flow->protos.slp.url_count = 1;
+        strncpy(flow->protos.slp.url[0], (char *)&packet->payload[sizeof(*hdr) + url_offset + 2], len);
+        flow->protos.slp.url[0][len] = 0;
+      }
+    }
+  }
+}
+
+static void ndpi_search_slp(struct ndpi_detection_module_struct *ndpi_struct,
+                            struct ndpi_flow_struct *flow)
+{
+  struct ndpi_packet_struct const * const packet = &ndpi_struct->packet;
+
+  NDPI_LOG_DBG(ndpi_struct, "search Service Location Protocol\n");
+
+  switch (packet->payload[0]) {
+    case 0x01:
+      ndpi_search_slp_v1(ndpi_struct, flow);
+      break;
+    case 0x02:
+      if (ndpi_search_slp_v2(ndpi_struct, flow) == 0) {
+        ndpi_dissect_slp_v2(ndpi_struct, flow);
+      }
+      break;
+    default:
+      NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
+      break;
+  }
+}
+
+void init_slp_dissector(struct ndpi_detection_module_struct *ndpi_struct,
+                        u_int32_t *id)
+{
+  ndpi_set_bitmask_protocol_detection("Service_Location_Protocol", ndpi_struct, *id,
+                                      NDPI_PROTOCOL_SERVICE_LOCATION,
+                                      ndpi_search_slp,
+                                      NDPI_SELECTION_BITMASK_PROTOCOL_V4_V6_TCP_OR_UDP_WITH_PAYLOAD_WITHOUT_RETRANSMISSION,
+                                      SAVE_DETECTION_BITMASK_AS_UNKNOWN,
+                                      ADD_TO_DETECTION_BITMASK);
+
+  *id += 1;
+}