Merge pull request #1771 from pi-hole/tweak/clients_mac_hostnames

/api/client: Include hostnames of clients specified by MAC

src/api/list.c

@@ -58,9 +58,11 @@ static int api_list_read(struct ftl_conn *api,
 			char *name = NULL;
 			if(table.client != NULL)
 			{
-				// Try to obtain hostname if this is a valid IP address
+				// Try to obtain hostname
 				if(isValidIPv4(table.client) || isValidIPv6(table.client))
 					name = getNameFromIP(NULL, table.client);
+				else if(isMAC(table.client))
+					name = getNameFromMAC(table.client);
 			}
 
 			JSON_COPY_STR_TO_OBJECT(row, "client", table.client);

src/database/network-table.c

@@ -2144,6 +2144,84 @@ char *__attribute__((malloc)) getNameFromIP(sqlite3 *db, const char *ipaddr)
 	return name;
 }
 
+// Get most recently seen host name of device identified by MAC address
+char *__attribute__((malloc)) getNameFromMAC(const char *client)
+{
+	// Return early if database is known to be broken
+	if(FTLDBerror())
+		return NULL;
+
+	log_debug(DEBUG_DATABASE,"Looking up host name for %s", client);
+
+	// Open pihole-FTL.db database file
+	sqlite3 *db = NULL;
+	if((db = dbopen(false, false)) == NULL)
+	{
+		log_warn("getNameFromMAC(\"%s\") - Failed to open DB", client);
+		return NULL;
+	}
+
+	// Check for a host name associated with the given client as MAC address
+	// COLLATE NOCASE: Case-insensitive comparison
+	const char *querystr = "SELECT name FROM network_addresses "
+	                               "WHERE name IS NOT NULL AND "
+	                                     "network_id = (SELECT id FROM network WHERE hwaddr = ? COLLATE NOCASE) "
+	                               "ORDER BY lastSeen DESC LIMIT 1";
+	sqlite3_stmt *stmt = NULL;
+	int rc = sqlite3_prepare_v2(db, querystr, -1, &stmt, NULL);
+	if(rc != SQLITE_OK)
+	{
+		log_err("getNameFromMAC(\"%s\") - SQL error prepare: %s",
+		        client, sqlite3_errstr(rc));
+		dbclose(&db);
+		return NULL;
+	}
+
+	// Bind client to prepared statement
+	if((rc = sqlite3_bind_text(stmt, 1, client, -1, SQLITE_STATIC)) != SQLITE_OK)
+	{
+		log_warn("getNameFromMAC(\"%s\"): Failed to bind ip: %s",
+		         client, sqlite3_errstr(rc));
+		checkFTLDBrc(rc);
+		sqlite3_reset(stmt);
+		sqlite3_finalize(stmt);
+
+		dbclose(&db);
+		return NULL;
+	}
+
+	char *name = NULL;
+	rc = sqlite3_step(stmt);
+	if(rc == SQLITE_ROW)
+	{
+		// Database record found (result might be empty)
+		name = strdup((char*)sqlite3_column_text(stmt, 0));
+
+		if(config.debug.resolver.v.b)
+			log_debug(DEBUG_RESOLVER, "Found database host name (by MAC) %s -> %s",
+			          client, name);
+	}
+	else if(rc == SQLITE_DONE)
+	{
+		// Not found
+		if(config.debug.resolver.v.b)
+			log_debug(DEBUG_RESOLVER, " ---> not found");
+	}
+	else
+	{
+		// Error
+		checkFTLDBrc(rc);
+		return NULL;
+	}
+
+	// Finalize statement and close database handle
+	sqlite3_reset(stmt);
+	sqlite3_finalize(stmt);
+
+	dbclose(&db);
+	return name;
+}
+
 // Get interface of device identified by IP address
 char *__attribute__((malloc)) getIfaceFromIP(sqlite3 *db, const char *ipaddr)
 {
@@ -2425,3 +2503,29 @@ bool networkTable_deleteDevice(sqlite3 *db, const int id, const char **message)
 
 	return true;
 }
+
+// Counting number of occurrences of a specific char in a string
+static size_t __attribute__ ((pure)) count_char(const char *haystack, const char needle)
+{
+	size_t count = 0u;
+	while(*haystack)
+		if (*haystack++ == needle)
+			++count;
+	return count;
+}
+
+// Identify MAC addresses using a set of suitable criteria
+bool __attribute__ ((pure)) isMAC(const char *input)
+{
+	if(input != NULL &&                // Valid input
+	   strlen(input) == 17u &&         // MAC addresses are always 17 chars long (6 bytes + 5 colons)
+	   count_char(input, ':') == 5u && // MAC addresses always have 5 colons
+	   strstr(input, "::") == NULL)    // No double-colons (IPv6 address abbreviation)
+	   {
+		// This is a MAC address of the form AA:BB:CC:DD:EE:FF
+		return true;
+	   }
+
+	// Not a MAC address
+	return false;
+}

src/database/network-table.h

@@ -18,12 +18,14 @@ bool create_network_addresses_with_names_table(sqlite3 *db);
 void parse_neighbor_cache(sqlite3 *db);
 void updateMACVendorRecords(sqlite3 *db);
 bool unify_hwaddr(sqlite3 *db);
-char* __attribute__((malloc)) getMACfromIP(sqlite3 *db, const char* ipaddr);
+char *getMACfromIP(sqlite3 *db, const char* ipaddr) __attribute__((malloc));
 int getAliasclientIDfromIP(sqlite3 *db, const char *ipaddr);
-char* __attribute__((malloc)) getNameFromIP(sqlite3 *db, const char* ipaddr);
-char* __attribute__((malloc)) getIfaceFromIP(sqlite3 *db, const char* ipaddr);
+char *getNameFromIP(sqlite3 *db, const char* ipaddr) __attribute__((malloc));
+char *getNameFromMAC(const char *client) __attribute__((malloc));
+char *getIfaceFromIP(sqlite3 *db, const char* ipaddr) __attribute__((malloc));
 void resolveNetworkTableNames(void);
 bool flush_network_table(void);
+bool isMAC(const char *input) __attribute__ ((pure));
 
 typedef struct {
 	unsigned int id;

src/database/sqlite3-ext.c

@@ -29,32 +29,6 @@
 // isMAC()
 #include "network-table.h"
 
-// Counting number of occurrences of a specific char in a string
-static size_t __attribute__ ((pure)) count_char(const char *haystack, const char needle)
-{
-	size_t count = 0u;
-	while(*haystack)
-		if (*haystack++ == needle)
-			++count;
-	return count;
-}
-
-// Identify MAC addresses using a set of suitable criteria
-static bool __attribute__ ((pure)) isMAC(const char *input)
-{
-	if(input != NULL &&                // Valid input
-	   strlen(input) == 17u &&         // MAC addresses are always 17 chars long (6 bytes + 5 colons)
-	   count_char(input, ':') == 5u && // MAC addresses always have 5 colons
-	   strstr(input, "::") == NULL)    // No double-colons (IPv6 address abbreviation)
-	   {
-		// This is a MAC address of the form AA:BB:CC:DD:EE:FF
-		return true;
-	   }
-
-	// Not a MAC address
-	return false;
-}
-
 static void subnet_match_impl(sqlite3_context *context, int argc, sqlite3_value **argv)
 {
 	// Exactly two arguments should be submitted to this routine