Try to obtain host names from another address of the same device when nothing else is available

src/database/gravity-db.c

@@ -337,7 +337,9 @@ static bool get_client_groupids(clientsData* client)
  {
  free(hwaddr);
  hwaddr = NULL;
- logg("Skipping mock-device hardware address lookup");
+
+ if(config.debug & DEBUG_CLIENTS)
+ logg("Skipping mock-device hardware address lookup");
  }
 
  // MAC address fallback: Try to synthesize MAC address from internal buffer
@@ -348,7 +350,9 @@ static bool get_client_groupids(clientsData* client)
  snprintf(hwaddr, strlen, "%02X:%02X:%02X:%02X:%02X:%02X",
  client->hwaddr[0], client->hwaddr[1], client->hwaddr[2],
  client->hwaddr[3], client->hwaddr[4], client->hwaddr[5]);
- logg("--> Obtained %s from internal ARP cache", hwaddr);
+
+ if(config.debug & DEBUG_CLIENTS)
+ logg("--> Obtained %s from internal ARP cache", hwaddr);
  }
  }
 
@@ -432,7 +436,8 @@ static bool get_client_groupids(clientsData* client)
  {
  free(hostname);
  hostname = NULL;
- logg("Skipping empty host name lookup");
+ if(config.debug & DEBUG_CLIENTS)
+ logg("Skipping empty host name lookup");
  }
  }
 
@@ -517,7 +522,8 @@ static bool get_client_groupids(clientsData* client)
  {
  free(interface);
  interface = 0;
- logg("Skipping empty interface lookup");
+ if(config.debug & DEBUG_CLIENTS)
+ logg("Skipping empty interface lookup");
  }
  }
 

src/database/network-table.c

@@ -1581,103 +1581,87 @@ void updateMACVendorRecords(void)
  dbclose();
 }
 
-char *__attribute__((malloc)) getDatabaseHostname(const char *ipaddr)
+// Get hardware address of device identified by IP address
+char *__attribute__((malloc)) getMACfromIP(const char *ipaddr)
 {
- // Test if this is an IPv6 address
- bool IPv6 = false;
- if(ipaddr != NULL && strstr(ipaddr,":") != NULL)
- {
- IPv6 = true;
- }
-
- // Do we want to resolve IPv4/IPv6 names at all?
- if( (IPv6 && !config.resolveIPv6) ||
- (!IPv6 && !config.resolveIPv4))
- {
- if(config.debug & DEBUG_RESOLVER)
- {
- logg(" ---> \"\" (configured to not resolve %s host names)",
- IPv6 ? "IPv6" : "IPv4");
- }
- return strdup("");
- }
-
  // Open pihole-FTL.db database file if needed
  const bool db_already_open = FTL_DB_avail();
  if(!db_already_open && !dbopen())
  {
- logg("getDatabaseHostname(\"%s\") - Failed to open DB", ipaddr);
+ logg("getMACfromIP(\"%s\") - Failed to open DB", ipaddr);
  return NULL;
  }
 
  // Prepare SQLite statement
+ // We request the most recent IP entry in case there an IP appears
+ // multiple times in the network_addresses table
  sqlite3_stmt *stmt = NULL;
- const char *querystr = "SELECT name FROM network_addresses "
- "WHERE name IS NOT NULL AND ip = ?;";
+ const char *querystr = "SELECT hwaddr FROM network WHERE id = "
+ "(SELECT network_id FROM network_addresses "
+ "WHERE ip = ? GROUP BY ip HAVING max(lastSeen));";
  int rc = sqlite3_prepare_v2(FTL_db, querystr, -1, &stmt, NULL);
  if( rc != SQLITE_OK ){
- logg("getDatabaseHostname(\"%s\") - SQL error prepare: %s",
+ logg("getMACfromIP(\"%s\") - SQL error prepare: %s",
  ipaddr, sqlite3_errstr(rc));
  if(!db_already_open)
  dbclose();
- return strdup("");
+ return NULL;
  }
 
  // Bind ipaddr to prepared statement
  if((rc = sqlite3_bind_text(stmt, 1, ipaddr, -1, SQLITE_STATIC)) != SQLITE_OK)
  {
- logg("getDatabaseHostname(\"%s\"): Failed to bind ip: %s",
+ logg("getMACfromIP(\"%s\"): Failed to bind ip: %s",
  ipaddr, sqlite3_errstr(rc));
  sqlite3_reset(stmt);
  sqlite3_finalize(stmt);
  if(!db_already_open)
  dbclose();
- return strdup("");
+ return NULL;
  }
 
- char *hostname = NULL;
+ char *hwaddr = NULL;
  rc = sqlite3_step(stmt);
  if(rc == SQLITE_ROW)
  {
  // Database record found (result might be empty)
- hostname = strdup((char*)sqlite3_column_text(stmt, 0));
+ hwaddr = strdup((char*)sqlite3_column_text(stmt, 0));
  }
  else
  {
  // Not found or error (will be logged automatically through our SQLite3 hook)
- hostname = strdup("");
+ hwaddr = NULL;
  }
 
+ if(config.debug & DEBUG_DATABASE && hwaddr != NULL)
+ logg("Found database hardware address %s -> %s", ipaddr, hwaddr);
+
  // Finalize statement and close database handle
  sqlite3_reset(stmt);
  sqlite3_finalize(stmt);
  if(!db_already_open)
  dbclose();
 
- return hostname;
+ return hwaddr;
 }
 
-// Get hardware address of device identified by IP address
-char *__attribute__((malloc)) getMACfromIP(const char *ipaddr)
+// Get host name of device identified by IP address
+char *__attribute__((malloc)) getNameFromIP(const char *ipaddr)
 {
  // Open pihole-FTL.db database file if needed
  const bool db_already_open = FTL_DB_avail();
  if(!db_already_open && !dbopen())
  {
- logg("getMACfromIP(\"%s\") - Failed to open DB", ipaddr);
+ logg("getNameFromIP(\"%s\") - Failed to open DB", ipaddr);
  return NULL;
  }
 
- // Prepare SQLite statement
- // We request the most recent IP entry in case there an IP appears
- // multiple times in the network_addresses table
+ // Check for a host name associated with the same IP address
  sqlite3_stmt *stmt = NULL;
- const char *querystr = "SELECT hwaddr FROM network WHERE id = "
- "(SELECT network_id FROM network_addresses "
- "WHERE ip = ? GROUP BY ip HAVING max(lastSeen));";
+ const char *querystr = "SELECT name FROM network_addresses WHERE name IS NOT NULL AND ip = ?;";
  int rc = sqlite3_prepare_v2(FTL_db, querystr, -1, &stmt, NULL);
  if( rc != SQLITE_OK ){
- logg("getMACfromIP(\"%s\") - SQL error prepare: %s",
+ logg("getNameFromIP(\"%s\") - SQL error prepare: %s",
  ipaddr, sqlite3_errstr(rc));
  if(!db_already_open)
  dbclose();
@@ -1687,7 +1671,7 @@ char *__attribute__((malloc)) getMACfromIP(const char *ipaddr)
  // Bind ipaddr to prepared statement
  if((rc = sqlite3_bind_text(stmt, 1, ipaddr, -1, SQLITE_STATIC)) != SQLITE_OK)
  {
- logg("getMACfromIP(\"%s\"): Failed to bind ip: %s",
+ logg("getNameFromIP(\"%s\"): Failed to bind ip: %s",
  ipaddr, sqlite3_errstr(rc));
  sqlite3_reset(stmt);
  sqlite3_finalize(stmt);
@@ -1696,49 +1680,45 @@ char *__attribute__((malloc)) getMACfromIP(const char *ipaddr)
  return NULL;
  }
 
- char *hwaddr = NULL;
+ char *name = NULL;
  rc = sqlite3_step(stmt);
  if(rc == SQLITE_ROW)
  {
  // Database record found (result might be empty)
- hwaddr = strdup((char*)sqlite3_column_text(stmt, 0));
+ name = strdup((char*)sqlite3_column_text(stmt, 0));
+
+ if(config.debug & DEBUG_DATABASE)
+ logg("Found database host name (same address) %s -> %s", ipaddr, name);
  }
  else
  {
  // Not found or error (will be logged automatically through our SQLite3 hook)
- hwaddr = NULL;
  }
 
- if(config.debug & DEBUG_DATABASE && hwaddr != NULL)
- logg("Found database hardware address %s -> %s", ipaddr, hwaddr);
-
- // Finalize statement and close database handle
+ // Finalize statement
  sqlite3_reset(stmt);
  sqlite3_finalize(stmt);
- if(!db_already_open)
- dbclose();
 
- return hwaddr;
-}
-
-// Get host name of device identified by IP address
-char *__attribute__((malloc)) getNameFromIP(const char *ipaddr)
-{
- // Open pihole-FTL.db database file if needed
- const bool db_already_open = FTL_DB_avail();
- if(!db_already_open && !dbopen())
+ // Return here if we found the name
+ if(name != NULL)
  {
- logg("getNameFromIP(\"%s\") - Failed to open DB", ipaddr);
- return NULL;
+ if(!db_already_open)
+ dbclose();
+
+ return name;
  }
 
- // Prepare SQLite statement
- sqlite3_stmt *stmt = NULL;
- const char *querystr = "SELECT name FROM network_addresses WHERE name IS NOT NULL AND ip = ?;";
- int rc = sqlite3_prepare_v2(FTL_db, querystr, -1, &stmt, NULL);
+ // Nothing found for the exact IP address
+ // Check for a host name associated with the same device (but another IP address)
+ querystr = "SELECT name FROM network_addresses "
+ "WHERE name IS NOT NULL AND "
+ "network_id = (SELECT network_id FROM network_addresses "
+ "WHERE ip = ?) "
+ "ORDER BY lastSeen DESC LIMIT 1";
+ rc = sqlite3_prepare_v2(FTL_db, querystr, -1, &stmt, NULL);
  if( rc != SQLITE_OK ){
  logg("getNameFromIP(\"%s\") - SQL error prepare: %s",
-  ipaddr, sqlite3_errstr(rc));
+ ipaddr, sqlite3_errstr(rc));
  if(!db_already_open)
  dbclose();
  return NULL;
@@ -1748,30 +1728,28 @@ char *__attribute__((malloc)) getNameFromIP(const char *ipaddr)
  if((rc = sqlite3_bind_text(stmt, 1, ipaddr, -1, SQLITE_STATIC)) != SQLITE_OK)
  {
  logg("getNameFromIP(\"%s\"): Failed to bind ip: %s",
-  ipaddr, sqlite3_errstr(rc));
+ ipaddr, sqlite3_errstr(rc));
  sqlite3_reset(stmt);
  sqlite3_finalize(stmt);
  if(!db_already_open)
  dbclose();
  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 & DEBUG_DATABASE)
+ logg("Found database host name (same device) %s -> %s", ipaddr, name);
  }
  else
  {
  // Not found or error (will be logged automatically through our SQLite3 hook)
  name = NULL;
  }
-
- if(config.debug & DEBUG_DATABASE && name != NULL)
- logg("Found database host name %s -> %s", ipaddr, name);
-
  // Finalize statement and close database handle
  sqlite3_reset(stmt);
  sqlite3_finalize(stmt);

src/database/network-table.h

@@ -16,10 +16,9 @@ bool create_network_addresses_with_names_table(void);
 void parse_neighbor_cache(void);
 void updateMACVendorRecords(void);
 bool unify_hwaddr(void);
-char* getDatabaseHostname(const char* ipaddr) __attribute__((malloc));
-char* __attribute__((malloc)) getMACfromIP(const char* ipaddr);
-char* __attribute__((malloc)) getNameFromIP(const char* ipaddr);
-char* __attribute__((malloc)) getIfaceFromIP(const char* ipaddr);
+char *getMACfromIP(const char* ipaddr) __attribute__((malloc));
+char *getNameFromIP(const char* ipaddr) __attribute__((malloc));
+char *getIfaceFromIP(const char* ipaddr) __attribute__((malloc));
 void resolveNetworkTableNames(void);
 
 #endif //NETWORKTABLE_H

src/resolve.c

@@ -134,17 +134,6 @@ char *resolveHostname(const char *addr)
  IPv6 = true;
  }
 
- if( (IPv6 && !config.resolveIPv6) ||
- (!IPv6 && !config.resolveIPv4))
- {
- if(config.debug & DEBUG_RESOLVER)
- {
- logg(" ---> \"\" (configured to not resolve %s host names)",
- IPv6 ? "IPv6" : "IPv4");
- }
- return strdup("");
- }
-
  // Initialize resolver subroutines if trying to resolve for the first time
  // res_init() reads resolv.conf to get the default domain name and name server
  // address(es). If no server is given, the local host is tried. If no domain
@@ -285,6 +274,24 @@ static size_t resolveAndAddHostname(size_t ippos, size_t oldnamepos)
  char* oldname = strdup(getstr(oldnamepos));
  unlock_shm();
 
+ // Test if we want to resolve an IPv6 address
+ bool IPv6 = false;
+ if(strstr(ipaddr,":") != NULL)
+ {
+ IPv6 = true;
+ }
+
+ if( (IPv6 && !config.resolveIPv6) ||
+ (!IPv6 && !config.resolveIPv4))
+ {
+ if(config.debug & DEBUG_RESOLVER)
+ {
+ logg(" ---> \"\" (configured to not resolve %s host names)",
+ IPv6 ? "IPv6" : "IPv4");
+ }
+ return 0;
+ }
+
  // Important: Don't hold a lock while resolving as the main thread
  // (dnsmasq) needs to be operable during the call to resolveHostname()
  char* newname = resolveHostname(ipaddr);
@@ -294,7 +301,7 @@ static size_t resolveAndAddHostname(size_t ippos, size_t oldnamepos)
  if(strlen(newname) == 0 && config.names_from_netdb)
  {
  free(newname);
- newname = getDatabaseHostname(ipaddr);
+ newname = getNameFromIP(ipaddr);
  }
 
  // Only store new newname if it is valid and differs from oldname
@@ -318,7 +325,8 @@ static size_t resolveAndAddHostname(size_t ippos, size_t oldnamepos)
  logg("Not adding \"%s\" to buffer (unchanged)", oldname);
  }
 
- free(newname);
+ if(newname != NULL)
+ free(newname);
  free(ipaddr);
  free(oldname);