diff --git a/FTL.h b/FTL.h
index a9c4775d..adee6061 100644
--- a/FTL.h
+++ b/FTL.h
@@ -80,6 +80,14 @@
 // can be 24 hours + 59 minutes
 #define OVERTIME_SLOTS ((MAXLOGAGE+1)*3600/OVERTIME_INTERVAL)
 
+// Interval for resolving NEW client and upstream server host names [seconds]
+// Default: 60 (once every minute)
+#define RESOLVE_INTERVAL 60
+
+// Interval for re-resolving ALL known host names [seconds]
+// Default: 3600 (once every hour)
+#define RERESOLVE_INTERVAL 3600
+
 // FTLDNS enums
 enum { DATABASE_WRITE_TIMER, EXIT_TIMER, GC_TIMER, LISTS_TIMER, REGEX_TIMER, ARP_TIMER, LAST_TIMER };
 enum { QUERIES, FORWARDED, CLIENTS, DOMAINS, OVERTIME, WILDCARD };
@@ -103,6 +111,8 @@ enum {
   DEBUG_REGEX      = (1 << 8),  /* 00000001 00000000 */
   DEBUG_API        = (1 << 9),  /* 00000010 00000000 */
   DEBUG_OVERTIME   = (1 << 10), /* 00000100 00000000 */
+  DEBUG_EXTBLOCKED = (1 << 11), /* 00001000 00000000 */
+  DEBUG_CAPS       = (1 << 12), /* 00010000 00000000 */
 };
 
 // Database table "ftl"
diff --git a/Makefile b/Makefile
index 6f7f78c7..009e18f0 100644
--- a/Makefile
+++ b/Makefile
@@ -98,7 +98,7 @@ CCFLAGS=-std=gnu11 -I$(IDIR) $(WARNFLAGS) -D_FILE_OFFSET_BITS=64 $(HARDENING_FLA
 # for dnsmasq we need the nettle crypto library and the gmp maths library
 # We link the two libraries statically. Although this increases the binary file size by about 1 MB, it saves about 5 MB of shared libraries and makes deployment easier
 #LIBS=-pthread -lnettle -lgmp -lhogweed
-LIBS=-pthread -lrt -lcap -Wl,-Bstatic -L/usr/local/lib -lhogweed -lgmp -lnettle -Wl,-Bdynamic
+LIBS=-pthread -lrt -Wl,-Bstatic -L/usr/local/lib -lhogweed -lgmp -lnettle -Wl,-Bdynamic
 # Flags for compiling with libidn : -lidn
 # Flags for compiling with libidn2: -lidn2
 
diff --git a/api.c b/api.c
index 28871a9b..b1585ba5 100644
--- a/api.c
+++ b/api.c
@@ -19,8 +19,8 @@
 /* qsort comparision function (count field), sort ASC */
 static int __attribute__((pure)) cmpasc(const void *a, const void *b)
 {
-	int *elem1 = (int*)a;
-	int *elem2 = (int*)b;
+	const int *elem1 = (int*)a;
+	const int *elem2 = (int*)b;
 
 	if (elem1[1] < elem2[1])
 		return -1;
@@ -33,8 +33,8 @@ static int __attribute__((pure)) cmpasc(const void *a, const void *b)
 // qsort subroutine, sort DESC
 static int __attribute__((pure)) cmpdesc(const void *a, const void *b)
 {
-	int *elem1 = (int*)a;
-	int *elem2 = (int*)b;
+	const int *elem1 = (int*)a;
+	const int *elem2 = (int*)b;
 
 	if (elem1[1] > elem2[1])
 		return -1;
@@ -44,10 +44,10 @@ static int __attribute__((pure)) cmpdesc(const void *a, const void *b)
 		return 0;
 }
 
-void getStats(int *sock)
+void getStats(const int *sock)
 {
-	int blocked = counters->blocked;
-	int total = counters->queries;
+	const int blocked = counters->blocked;
+	const int total = counters->queries;
 	float percentage = 0.0f;
 
 	// Avoid 1/0 condition
@@ -112,7 +112,7 @@ void getStats(int *sock)
 		pack_uint8(*sock, blockingstatus);
 }
 
-void getOverTime(int *sock)
+void getOverTime(const int *sock)
 {
 	int from = 0, until = OVERTIME_SLOTS;
 	bool found = false;
@@ -175,12 +175,12 @@ void getOverTime(int *sock)
 	}
 }
 
-void getTopDomains(const char *client_message, int *sock)
+void getTopDomains(const char *client_message, const int *sock)
 {
 	int temparray[counters->domains][2], count=10, num;
-	bool blocked, audit = false, asc = false;
+	bool audit = false, asc = false;
 
-	blocked = command(client_message, ">top-ads");
+	const bool blocked = command(client_message, ">top-ads");
 
 	// Exit before processing any data if requested via config setting
 	get_privacy_level(NULL);
@@ -230,7 +230,7 @@ void getTopDomains(const char *client_message, int *sock)
 
 
 	// Get filter
-	char * filter = read_setupVarsconf("API_QUERY_LOG_SHOW");
+	const char* filter = read_setupVarsconf("API_QUERY_LOG_SHOW");
 	bool showpermitted = true, showblocked = true;
 	if(filter != NULL)
 	{
@@ -270,8 +270,7 @@ void getTopDomains(const char *client_message, int *sock)
 	for(int i=0; i < counters->domains; i++)
 	{
 		// Get sorted index
-		int domainID = temparray[i][0];
-
+		const int domainID = temparray[i][0];
 		// Get domain pointer
 		const domainsData* domain = getDomain(domainID, true);
 
@@ -341,7 +340,7 @@ void getTopDomains(const char *client_message, int *sock)
 		clearSetupVarsArray();
 }
 
-void getTopClients(const char *client_message, int *sock)
+void getTopClients(const char *client_message, const int *sock)
 {
 	int temparray[counters->clients][2], count=10, num;
 
@@ -398,7 +397,7 @@ void getTopClients(const char *client_message, int *sock)
 		qsort(temparray, counters->clients, sizeof(int[2]), cmpdesc);
 
 	// Get clients which the user doesn't want to see
-	char* excludeclients = read_setupVarsconf("API_EXCLUDE_CLIENTS");
+	const char* excludeclients = read_setupVarsconf("API_EXCLUDE_CLIENTS");
 	if(excludeclients != NULL)
 	{
 		getSetupVarsArray(excludeclients);
@@ -414,8 +413,8 @@ void getTopClients(const char *client_message, int *sock)
 	for(int i=0; i < counters->clients; i++)
 	{
 		// Get sorted indices and counter values (may be either total or blocked count)
-		int clientID = temparray[i][0];
-		int ccount = temparray[i][1];
+		const int clientID = temparray[i][0];
+		const int ccount = temparray[i][1];
 		// Get client pointer
 		const clientsData* client = getClient(clientID, true);
 
@@ -458,7 +457,7 @@ void getTopClients(const char *client_message, int *sock)
 }
 
 
-void getForwardDestinations(const char *client_message, int *sock)
+void getForwardDestinations(const char *client_message, const int *sock)
 {
 	bool sort = true;
 	int temparray[counters->forwarded][2], totalqueries = 0;
@@ -554,7 +553,7 @@ void getForwardDestinations(const char *client_message, int *sock)
 }
 
 
-void getQueryTypes(int *sock)
+void getQueryTypes(const int *sock)
 {
 	int total = 0;
 	for(int i=0; i < TYPE_MAX-1; i++)
@@ -598,7 +597,7 @@ void getQueryTypes(int *sock)
 
 const char *querytypes[8] = {"A","AAAA","ANY","SRV","SOA","PTR","TXT","UNKN"};
 
-void getAllQueries(const char *client_message, int *sock)
+void getAllQueries(const char *client_message, const int *sock)
 {
 	// Exit before processing any data if requested via config setting
 	get_privacy_level(NULL);
@@ -872,7 +871,7 @@ void getAllQueries(const char *client_message, int *sock)
 		free(forwarddest);
 }
 
-void getRecentBlocked(const char *client_message, int *sock)
+void getRecentBlocked(const char *client_message, const int *sock)
 {
 	int num=1;
 
@@ -910,7 +909,7 @@ void getRecentBlocked(const char *client_message, int *sock)
 	}
 }
 
-void getClientID(int *sock)
+void getClientID(const int *sock)
 {
 	if(istelnet[*sock])
 		ssend(*sock,"%i\n", *sock);
@@ -918,10 +917,11 @@ void getClientID(int *sock)
 		pack_int32(*sock, *sock);
 }
 
-void getQueryTypesOverTime(int *sock)
+void getQueryTypesOverTime(const int *sock)
 {
 	int from = -1, until = OVERTIME_SLOTS;
-	time_t mintime = overTime[0].timestamp;
+	const time_t mintime = overTime[0].timestamp;
+
 	for(int slot = 0; slot < OVERTIME_SLOTS; slot++)
 	{
 		if((overTime[slot].total > 0 || overTime[slot].blocked > 0) && overTime[slot].timestamp >= mintime)
@@ -965,7 +965,7 @@ void getQueryTypesOverTime(int *sock)
 	}
 }
 
-void getVersion(int *sock)
+void getVersion(const int *sock)
 {
 	const char * commit = GIT_HASH;
 	const char * tag = GIT_TAG;
@@ -1014,7 +1014,7 @@ void getVersion(int *sock)
 	}
 }
 
-void getDBstats(int *sock)
+void getDBstats(const int *sock)
 {
 	// Get file details
 	struct stat st;
@@ -1041,7 +1041,7 @@ void getDBstats(int *sock)
 	}
 }
 
-void getClientsOverTime(int *sock)
+void getClientsOverTime(const int *sock)
 {
 	int sendit = -1, until = OVERTIME_SLOTS;
 
@@ -1112,8 +1112,7 @@ void getClientsOverTime(int *sock)
 
 			// Get client pointer
 			const clientsData* client = getClient(clientID, true);
-
-			int thisclient = client->overTime[slot];
+			const int thisclient = client->overTime[slot];
 
 			if(istelnet[*sock])
 				ssend(*sock, " %i", thisclient);
@@ -1131,7 +1130,7 @@ void getClientsOverTime(int *sock)
 		clearSetupVarsArray();
 }
 
-void getClientNames(int *sock)
+void getClientNames(const int *sock)
 {
 	// Exit before processing any data if requested via config setting
 	get_privacy_level(NULL);
@@ -1169,7 +1168,6 @@ void getClientNames(int *sock)
 
 		// Get client pointer
 		const clientsData* client = getClient(clientID, true);
-
 		const char *client_ip = getstr(client->ippos);
 		const char *client_name = getstr(client->namepos);
 
@@ -1185,7 +1183,7 @@ void getClientNames(int *sock)
 		clearSetupVarsArray();
 }
 
-void getUnknownQueries(int *sock)
+void getUnknownQueries(const int *sock)
 {
 	// Exit before processing any data if requested via config setting
 	get_privacy_level(NULL);
@@ -1236,7 +1234,7 @@ void getUnknownQueries(int *sock)
 	}
 }
 
-void getDomainDetails(const char *client_message, int *sock)
+void getDomainDetails(const char *client_message, const int *sock)
 {
 	// Get domain name
 	char domainString[128];
diff --git a/api.h b/api.h
index ed2203d6..c329342d 100644
--- a/api.h
+++ b/api.h
@@ -9,36 +9,36 @@
 *  Please see LICENSE file for your rights under this license. */
 
 // Statistic methods
-void getStats(int *sock);
-void getOverTime(int *sock);
-void getTopDomains(const char *client_message, int *sock);
-void getTopClients(const char *client_message, int *sock);
-void getForwardDestinations(const char *client_message, int *sock);
-void getQueryTypes(int *sock);
-void getAllQueries(const char *client_message, int *sock);
-void getRecentBlocked(const char *client_message, int *sock);
-void getQueryTypesOverTime(int *sock);
-void getClientsOverTime(int *sock);
-void getClientNames(int *sock);
-void getDomainDetails(const char *client_message, int *sock);
+void getStats(const int *sock);
+void getOverTime(const int *sock);
+void getTopDomains(const char *client_message, const int *sock);
+void getTopClients(const char *client_message, const int *sock);
+void getForwardDestinations(const char *client_message, const int *sock);
+void getQueryTypes(const int *sock);
+void getAllQueries(const char *client_message, const int *sock);
+void getRecentBlocked(const char *client_message, const int *sock);
+void getQueryTypesOverTime(const int *sock);
+void getClientsOverTime(const int *sock);
+void getClientNames(const int *sock);
+void getDomainDetails(const char *client_message, const int *sock);
 
 // FTL methods
-void getClientID(int *sock);
-void getVersion(int *sock);
-void getDBstats(int *sock);
-void getUnknownQueries(int *sock);
+void getClientID(const int *sock);
+void getVersion(const int *sock);
+void getDBstats(const int *sock);
+void getUnknownQueries(const int *sock);
 
 // DNS resolver methods (dnsmasq_interface.c)
-void getCacheInformation(int *sock);
+void getCacheInformation(const int *sock);
 
 // MessagePack serialization helpers
-void pack_eom(int sock);
-void pack_bool(int sock, bool value);
-void pack_uint8(int sock, uint8_t value);
-void pack_uint64(int sock, uint64_t value);
-void pack_int32(int sock, int32_t value);
-void pack_int64(int sock, int64_t value);
-void pack_float(int sock, float value);
-bool pack_fixstr(int sock, const char *string);
-bool pack_str32(int sock, const char *string);
-void pack_map16_start(int sock, uint16_t length);
+void pack_eom(const int sock);
+void pack_bool(const int sock, const bool value);
+void pack_uint8(const int sock, const uint8_t value);
+void pack_uint64(const int sock, const uint64_t value);
+void pack_int32(const int sock, const int32_t value);
+void pack_int64(const int sock, const int64_t value);
+void pack_float(const int sock, const float value);
+bool pack_fixstr(const int sock, const char *string);
+bool pack_str32(const int sock, const char *string);
+void pack_map16_start(const int sock, const uint16_t length);
diff --git a/args.c b/args.c
index 8e2bdbf5..eb03049e 100644
--- a/args.c
+++ b/args.c
@@ -52,7 +52,6 @@ void parse_args(int argc, char* argv[])
 		   strcmp(argv[i], "version") == 0 ||
 		   strcmp(argv[i], "--version") == 0)
 		{
-			const char * commit = GIT_HASH;
 			const char * tag = GIT_TAG;
 			if(strlen(tag) > 1)
 			{
@@ -60,6 +59,7 @@ void parse_args(int argc, char* argv[])
 			}
 			else
 			{
+				const char * commit = GIT_HASH;
 				char hash[8];
 				// Extract first 7 characters of the hash
 				strncpy(hash, commit, 7); hash[7] = 0;
diff --git a/capabilities.c b/capabilities.c
index 1a33fee8..3d3a8e4b 100644
--- a/capabilities.c
+++ b/capabilities.c
@@ -8,36 +8,99 @@
 *  This file is copyright under the latest version of the EUPL.
 *  Please see LICENSE file for your rights under this license. */
 
+// Definition of LINUX_CAPABILITY_VERSION_*
+#define FTLDNS
+#include "dnsmasq/dnsmasq.h"
+#undef __USE_XOPEN
 #include "FTL.h"
-#include <sys/capability.h>
 
-bool check_capabilities()
+static const unsigned int capabilityIDs[]   = { CAP_CHOWN ,  CAP_DAC_OVERRIDE ,  CAP_DAC_READ_SEARCH ,  CAP_FOWNER ,  CAP_FSETID ,  CAP_KILL ,  CAP_SETGID ,  CAP_SETUID ,  CAP_SETPCAP ,  CAP_LINUX_IMMUTABLE ,  CAP_NET_BIND_SERVICE ,  CAP_NET_BROADCAST ,  CAP_NET_ADMIN ,  CAP_NET_RAW ,  CAP_IPC_LOCK ,  CAP_IPC_OWNER ,  CAP_SYS_MODULE ,  CAP_SYS_RAWIO ,  CAP_SYS_CHROOT ,  CAP_SYS_PTRACE ,  CAP_SYS_PACCT ,  CAP_SYS_ADMIN ,  CAP_SYS_BOOT ,  CAP_SYS_NICE ,  CAP_SYS_RESOURCE ,  CAP_SYS_TIME ,  CAP_SYS_TTY_CONFIG ,  CAP_MKNOD ,  CAP_LEASE ,  CAP_AUDIT_WRITE ,  CAP_AUDIT_CONTROL ,  CAP_SETFCAP ,  CAP_MAC_OVERRIDE ,  CAP_MAC_ADMIN ,  CAP_SYSLOG ,  CAP_WAKE_ALARM ,  CAP_BLOCK_SUSPEND ,  CAP_AUDIT_READ };
+static const char*        capabilityNames[] = {"CAP_CHOWN", "CAP_DAC_OVERRIDE", "CAP_DAC_READ_SEARCH", "CAP_FOWNER", "CAP_FSETID", "CAP_KILL", "CAP_SETGID", "CAP_SETUID", "CAP_SETPCAP", "CAP_LINUX_IMMUTABLE", "CAP_NET_BIND_SERVICE", "CAP_NET_BROADCAST", "CAP_NET_ADMIN", "CAP_NET_RAW", "CAP_IPC_LOCK", "CAP_IPC_OWNER", "CAP_SYS_MODULE", "CAP_SYS_RAWIO", "CAP_SYS_CHROOT", "CAP_SYS_PTRACE", "CAP_SYS_PACCT", "CAP_SYS_ADMIN", "CAP_SYS_BOOT", "CAP_SYS_NICE", "CAP_SYS_RESOURCE", "CAP_SYS_TIME", "CAP_SYS_TTY_CONFIG", "CAP_MKNOD", "CAP_LEASE", "CAP_AUDIT_WRITE", "CAP_AUDIT_CONTROL", "CAP_SETFCAP", "CAP_MAC_OVERRIDE", "CAP_MAC_ADMIN", "CAP_SYSLOG", "CAP_WAKE_ALARM", "CAP_BLOCK_SUSPEND", "CAP_AUDIT_READ"};
+static const unsigned int numCaps = sizeof(capabilityIDs) / sizeof(const unsigned int);
+
+bool check_capabilities(void)
 {
-	if(!cap_get_bound(CAP_NET_ADMIN))
+	// First assume header version 1
+	int capsize = 1; // VFS_CAP_U32_1
+	cap_user_data_t data = NULL;
+	cap_user_header_t hdr = calloc(sizeof(*hdr), capsize);
+
+	// Determine capabilities version used by the current kernel
+	capget(hdr, NULL);
+
+	// Check version
+	if (hdr->version != LINUX_CAPABILITY_VERSION_1)
+	{
+		// If unknown version, use largest supported version (3)
+		// Version 2 is deprecated according to linux/capability.h
+		if (hdr->version != LINUX_CAPABILITY_VERSION_2)
+		{
+			hdr->version = LINUX_CAPABILITY_VERSION_3;
+			capsize = 2; // VFS_CAP_U32_3
+		}
+		else
+		{
+			// Use version 2
+			capsize = 2; // VFS_CAP_U32_2
+		}
+	}
+
+	// Get current capabilities
+	data = calloc(sizeof(*data), capsize);
+	capget(hdr, data);
+
+	if(config.debug & DEBUG_CAPS)
+	{
+		logg("***************************************");
+		logg("* Linux capability debugging enabled  *");
+		for(unsigned int i = 0u; i < numCaps; i++)
+		{
+			const unsigned int capid = capabilityIDs[i];
+
+			// Check if capability is valid for the current kernel
+			// If not, exit loop early
+			if(!cap_valid(capid))
+				break;
+
+			logg("* %-24s (%02u) = %s%s%s *",
+			     capabilityNames[capid], capid,
+			     ((data->permitted   & (1 << capid)) ? "P":"-"),
+			     ((data->inheritable & (1 << capid)) ? "I":"-"),
+			     ((data->effective   & (1 << capid)) ? "E":"-"));
+		}
+		logg("***************************************");
+	}
+
+	bool capabilities_okay = true;
+	if (!(data->permitted & (1 << CAP_NET_ADMIN)))
 	{
 		// Needed for ARP-injection (used when we're the DHCP server)
-		logg("**************************************************************");
-		logg("WARNING: Required linux capability CAP_NET_ADMIN not available");
-		logg("**************************************************************");
-		return false;
+		logg("*************************************************************************");
+		logg("* WARNING: Required Linux capability CAP_NET_ADMIN not available        *");
+		logg("*************************************************************************");
+		capabilities_okay = false;
 	}
-	if(!cap_get_bound(CAP_NET_RAW))
+	if (!(data->permitted & (1 << CAP_NET_RAW)))
 	{
 		// Needed for raw socket access (necessary for ICMP)
-		logg("************************************************************");
-		logg("WARNING: Required linux capability CAP_NET_RAW not available");
-		logg("************************************************************");
-		return false;
+		logg("*************************************************************************");
+		logg("* WARNING: Required Linux capability CAP_NET_RAW not available          *");
+		logg("*************************************************************************");
+		capabilities_okay = false;
 	}
-	if(!cap_get_bound(CAP_NET_BIND_SERVICE))
+	if (!(data->permitted & (1 << CAP_NET_BIND_SERVICE)))
 	{
 		// Necessary for dynamic port binding
-		logg("*********************************************************************");
-		logg("WARNING: Required linux capability CAP_NET_BIND_SERVICE not available");
-		logg("*********************************************************************");
-		return false;
+		logg("*************************************************************************");
+		logg("* WARNING: Required Linux capability CAP_NET_BIND_SERVICE not available *");
+		logg("*************************************************************************");
+		capabilities_okay = false;
 	}
 
-	// All okay!
-	return true;
+	// Free allocated memory
+	free(hdr);
+	free(data);
+
+	// Return whether capabilities are all okay
+	return capabilities_okay;
 }
diff --git a/config.c b/config.c
index 5664f3c5..460d0297 100644
--- a/config.c
+++ b/config.c
@@ -13,7 +13,7 @@
 ConfigStruct config;
 static char *parse_FTLconf(FILE *fp, const char * key);
 static void release_config_memory(void);
-void getpath(FILE* fp, const char *option, const char *defaultloc, char **pointer);
+static void getpath(FILE* fp, const char *option, const char *defaultloc, char **pointer);
 
 char *conflinebuffer = NULL;
 
@@ -334,7 +334,7 @@ void read_FTLconf(void)
 		fclose(fp);
 }
 
-void getpath(FILE* fp, const char *option, const char *defaultloc, char **pointer)
+static void getpath(FILE* fp, const char *option, const char *defaultloc, char **pointer)
 {
 	// This subroutine is used to read paths from pihole-FTL.conf
 	// fp:         File pointer to opened and readable config file
@@ -588,6 +588,18 @@ void read_debuging_settings(FILE *fp)
 	if(buffer != NULL && strcasecmp(buffer, "true") == 0)
 		config.debug |= DEBUG_OVERTIME;
 
+	// DEBUG_EXTBLOCKED
+	// defaults to: false
+	buffer = parse_FTLconf(fp, "DEBUG_EXTBLOCKED");
+	if(buffer != NULL && strcasecmp(buffer, "true") == 0)
+		config.debug |= DEBUG_EXTBLOCKED;
+
+	// DEBUG_CAPS
+	// defaults to: false
+	buffer = parse_FTLconf(fp, "DEBUG_CAPS");
+	if(buffer != NULL && strcasecmp(buffer, "true") == 0)
+		config.debug |= DEBUG_CAPS;
+
 	// DEBUG_ALL
 	// defaults to: false
 	buffer = parse_FTLconf(fp, "DEBUG_ALL");
@@ -609,6 +621,8 @@ void read_debuging_settings(FILE *fp)
 		logg("* DEBUG_REGEX      %s *", (config.debug & DEBUG_REGEX)? "YES":"NO ");
 		logg("* DEBUG_API        %s *", (config.debug & DEBUG_API)? "YES":"NO ");
 		logg("* DEBUG_OVERTIME   %s *", (config.debug & DEBUG_OVERTIME)? "YES":"NO ");
+		logg("* DEBUG_EXTBLOCKED %s *", (config.debug & DEBUG_EXTBLOCKED)? "YES":"NO ");
+		logg("* DEBUG_CAPS       %s *", (config.debug & DEBUG_CAPS)? "YES":"NO ");
 		logg("************************");
 	}
 
diff --git a/daemon.c b/daemon.c
index 9236c36a..ef4b6176 100644
--- a/daemon.c
+++ b/daemon.c
@@ -14,11 +14,8 @@ struct timeval t0[NUMTIMERS];
 
 void go_daemon(void)
 {
-	pid_t process_id = 0;
-	pid_t sid = 0;
-
 	// Create child process
-	process_id = fork();
+	pid_t process_id = fork();
 
 	// Indication of fork() failure
 	if (process_id < 0)
@@ -41,7 +38,7 @@ void go_daemon(void)
 
 	//set new session
 	// creates a session and sets the process group ID
-	sid = setsid();
+	const pid_t sid = setsid();
 	if(sid < 0)
 	{
 		// Return failure
@@ -80,7 +77,7 @@ void go_daemon(void)
 	// Closing stdin, stdout and stderr is handled by dnsmasq
 }
 
-void timer_start(int i)
+void timer_start(const int i)
 {
 	if(i >= NUMTIMERS)
 	{
@@ -90,7 +87,7 @@ void timer_start(int i)
 	gettimeofday(&t0[i], 0);
 }
 
-double timer_elapsed_msec(int i)
+double timer_elapsed_msec(const int i)
 {
 	if(i >= NUMTIMERS)
 	{
@@ -102,7 +99,7 @@ double timer_elapsed_msec(int i)
 	return (t1.tv_sec - t0[i].tv_sec) * 1000.0f + (t1.tv_usec - t0[i].tv_usec) / 1000.0f;
 }
 
-void sleepms(int milliseconds)
+void sleepms(const int milliseconds)
 {
 	struct timeval tv;
 	tv.tv_sec = milliseconds / 1000;
@@ -113,7 +110,7 @@ void sleepms(int milliseconds)
 void savepid(void)
 {
 	FILE *f;
-	pid_t pid = getpid();
+	const pid_t pid = getpid();
 	if((f = fopen(FTLfiles.pid, "w+")) == NULL)
 	{
 		logg("WARNING: Unable to write PID to file.");
@@ -143,8 +140,8 @@ char *getUserName(void)
 	char * name;
 	// the getpwuid() function shall search the user database for an entry with a matching uid
 	// the geteuid() function shall return the effective user ID of the calling process - this is used as the search criteria for the getpwuid() function
-	uid_t euid = geteuid();
-	struct passwd *pw = getpwuid(euid);
+	const uid_t euid = geteuid();
+	const struct passwd *pw = getpwuid(euid);
 	if(pw)
 	{
 		name = strdup(pw->pw_name);
diff --git a/database.c b/database.c
index 79fbd3a4..d83b53cb 100644
--- a/database.c
+++ b/database.c
@@ -19,8 +19,8 @@ long int lastdbindex = 0;
 
 static pthread_mutex_t dblock;
 
-bool db_set_counter(unsigned int ID, int value);
-int db_get_FTL_property(unsigned int ID);
+static bool db_set_counter(const unsigned int ID, const int value);
+static int db_get_FTL_property(const unsigned int ID);
 
 static void check_database(int rc)
 {
@@ -265,7 +265,7 @@ void db_init(void)
 	database = true;
 }
 
-int db_get_FTL_property(unsigned int ID)
+static int db_get_FTL_property(const unsigned int ID)
 {
 	// Prepare SQL statement
 	char* querystr = NULL;
@@ -283,17 +283,17 @@ int db_get_FTL_property(unsigned int ID)
 	return value;
 }
 
-bool db_set_FTL_property(unsigned int ID, int value)
+bool db_set_FTL_property(const unsigned int ID, const int value)
 {
 	return dbquery("INSERT OR REPLACE INTO ftl (id, value) VALUES ( %u, %i );", ID, value);
 }
 
-bool db_set_counter(unsigned int ID, int value)
+static bool db_set_counter(const unsigned int ID, const int value)
 {
 	return dbquery("INSERT OR REPLACE INTO counters (id, value) VALUES ( %u, %i );", ID, value);
 }
 
-static bool db_update_counters(int total, int blocked)
+static bool db_update_counters(const int total, const int blocked)
 {
 	if(!dbquery("UPDATE counters SET value = value + %i WHERE id = %i;", total, DB_TOTALQUERIES))
 		return false;
@@ -428,7 +428,7 @@ void save_to_DB(void)
 	}
 
 	unsigned int saved = 0, saved_error = 0;
-	sqlite3_stmt* stmt;
+	sqlite3_stmt* stmt = NULL;
 
 	// Get last ID stored in the database
 	sqlite3_int64 lastID = last_ID_in_DB();
@@ -597,7 +597,7 @@ static void delete_old_queries_in_DB(void)
 	}
 
 	// Get how many rows have been affected (deleted)
-	int affected = sqlite3_changes(db);
+	const int affected = sqlite3_changes(db);
 
 	// Print final message only if there is a difference
 	if((config.debug & DEBUG_DATABASE) || affected)
@@ -672,8 +672,8 @@ void read_data_from_DB(void)
 	// Prepare request
 	char *rstr = NULL;
 	// Get time stamp 24 hours in the past
-	time_t now = time(NULL);
-	time_t mintime = now - config.maxlogage;
+	const time_t now = time(NULL);
+	const time_t mintime = now - config.maxlogage;
 	int rc = asprintf(&rstr, "SELECT * FROM queries WHERE timestamp >= %li", mintime);
 	if(rc < 1)
 	{
@@ -684,7 +684,7 @@ void read_data_from_DB(void)
 	if(config.debug & DEBUG_DATABASE) logg("%s", rstr);
 
 	// Prepare SQLite3 statement
-	sqlite3_stmt* stmt;
+	sqlite3_stmt* stmt = NULL;
 	rc = sqlite3_prepare_v2(db, rstr, -1, &stmt, NULL);
 	if( rc ){
 		logg("read_data_from_DB() - SQL error prepare (%i): %s", rc, sqlite3_errmsg(db));
@@ -696,8 +696,8 @@ void read_data_from_DB(void)
 	// Loop through returned database rows
 	while((rc = sqlite3_step(stmt)) == SQLITE_ROW)
 	{
-		sqlite3_int64 dbid = sqlite3_column_int64(stmt, 0);
-		time_t queryTimeStamp = sqlite3_column_int(stmt, 1);
+		const sqlite3_int64 dbid = sqlite3_column_int64(stmt, 0);
+		const time_t queryTimeStamp = sqlite3_column_int(stmt, 1);
 		// 1483228800 = 01/01/2017 @ 12:00am (UTC)
 		if(queryTimeStamp < 1483228800)
 		{
@@ -710,7 +710,7 @@ void read_data_from_DB(void)
 			continue;
 		}
 
-		int type = sqlite3_column_int(stmt, 2);
+		const int type = sqlite3_column_int(stmt, 2);
 		if(type < TYPE_A || type >= TYPE_MAX)
 		{
 			logg("DB warn: TYPE should not be %i", type);
@@ -723,7 +723,7 @@ void read_data_from_DB(void)
 			continue;
 		}
 
-		int status = sqlite3_column_int(stmt, 3);
+		const int status = sqlite3_column_int(stmt, 3);
 		if(status < QUERY_UNKNOWN || status > QUERY_EXTERNAL_BLOCKED_NXRA)
 		{
 			logg("DB warn: STATUS should be within [%i,%i] but is %i", QUERY_UNKNOWN, QUERY_EXTERNAL_BLOCKED_NXRA, status);
@@ -766,15 +766,15 @@ void read_data_from_DB(void)
 		}
 
 		// Obtain IDs only after filtering which queries we want to keep
-		int timeidx = getOverTimeID(queryTimeStamp);
-		int domainID = findDomainID(domainname);
-		int clientID = findClientID(clientIP, true);
+		const int timeidx = getOverTimeID(queryTimeStamp);
+		const int domainID = findDomainID(domainname);
+		const int clientID = findClientID(clientIP, true);
 
 		// Ensure we have enough space in the queries struct
 		memory_check(QUERIES);
 
 		// Set index for this query
-		int queryIndex = counters->queries;
+		const int queryIndex = counters->queries;
 
 		// Store this query in memory
 		queriesData* query = getQuery(queryIndex, false);
diff --git a/datastructure.c b/datastructure.c
index 75905c06..4de41130 100644
--- a/datastructure.c
+++ b/datastructure.c
@@ -17,7 +17,7 @@ void strtolower(char *str)
 	while(str[i]){ str[i] = tolower(str[i]); i++; }
 }
 
-int findForwardID(const char * forwardString, bool count)
+int findForwardID(const char * forwardString, const bool count)
 {
 	// Go through already knows forward servers and see if we used one of those
 	for(int forwardID=0; forwardID < counters->forwarded; forwardID++)
@@ -109,7 +109,7 @@ int findDomainID(const char *domainString)
 	return domainID;
 }
 
-int findClientID(const char *clientIP, bool count)
+int findClientID(const char *clientIP, const bool count)
 {
 	// Compare content of client against known client IP addresses
 	for(int clientID=0; clientID < counters->clients; clientID++)
@@ -187,7 +187,7 @@ bool isValidIPv6(const char *addr)
 
 // Privacy-level sensitive subroutine that returns the domain name
 // only when appropriate for the requested query
-const char *getDomainString(int queryID)
+const char *getDomainString(const int queryID)
 {
 	const queriesData* query = getQuery(queryID, true);
 	if(query->privacylevel < PRIVACY_HIDE_DOMAINS)
@@ -204,7 +204,7 @@ const char *getDomainString(int queryID)
 
 // Privacy-level sensitive subroutine that returns the client IP
 // only when appropriate for the requested query
-const char *getClientIPString(int queryID)
+const char *getClientIPString(const int queryID)
 {
 	const queriesData* query = getQuery(queryID, false);
 	if(query->privacylevel < PRIVACY_HIDE_DOMAINS_CLIENTS)
@@ -221,7 +221,7 @@ const char *getClientIPString(int queryID)
 
 // Privacy-level sensitive subroutine that returns the client host name
 // only when appropriate for the requested query
-const char *getClientNameString(int queryID)
+const char *getClientNameString(const int queryID)
 {
 	const queriesData* query = getQuery(queryID, true);
 	if(query->privacylevel < PRIVACY_HIDE_DOMAINS_CLIENTS)
diff --git a/dnsmasq_interface.c b/dnsmasq_interface.c
index 5864d084..3be6e79c 100644
--- a/dnsmasq_interface.c
+++ b/dnsmasq_interface.c
@@ -17,18 +17,20 @@
 // Prototype of getCacheInformation()
 #include "api.h"
 
-void print_flags(unsigned int flags);
-void save_reply_type(unsigned int flags, int queryID, struct timeval response);
-static unsigned long converttimeval(struct timeval time) __attribute__((const));
-static void block_single_domain_regex(char *domain);
-static void detect_blocked_IP(unsigned short flags, const char* answer, int queryID);
-static void query_externally_blocked(int i, unsigned char status);
-static int findQueryID(int id);
+static void print_flags(const unsigned int flags);
+static void save_reply_type(const unsigned int flags, const int queryID, const struct timeval response);
+static unsigned long converttimeval(const struct timeval time) __attribute__((const));
+static void block_single_domain_regex(const char *domain);
+static void detect_blocked_IP(const unsigned short flags, const char* answer, const int queryID);
+static void query_externally_blocked(const int queryID, const unsigned char status);
+static int findQueryID(const int id);
 
 unsigned char* pihole_privacylevel = &config.privacylevel;
-char flagnames[28][12] = {"F_IMMORTAL ", "F_NAMEP ", "F_REVERSE ", "F_FORWARD ", "F_DHCP ", "F_NEG ", "F_HOSTS ", "F_IPV4 ", "F_IPV6 ", "F_BIGNAME ", "F_NXDOMAIN ", "F_CNAME ", "F_DNSKEY ", "F_CONFIG ", "F_DS ", "F_DNSSECOK ", "F_UPSTREAM ", "F_RRNAME ", "F_SERVER ", "F_QUERY ", "F_NOERR ", "F_AUTH ", "F_DNSSEC ", "F_KEYTAG ", "F_SECSTAT ", "F_NO_RR ", "F_IPSET ", "F_NOEXTRA "};
+const char flagnames[28][12] = {"F_IMMORTAL ", "F_NAMEP ", "F_REVERSE ", "F_FORWARD ", "F_DHCP ", "F_NEG ", "F_HOSTS ", "F_IPV4 ", "F_IPV6 ", "F_BIGNAME ", "F_NXDOMAIN ", "F_CNAME ", "F_DNSKEY ", "F_CONFIG ", "F_DS ", "F_DNSSECOK ", "F_UPSTREAM ", "F_RRNAME ", "F_SERVER ", "F_QUERY ", "F_NOERR ", "F_AUTH ", "F_DNSSEC ", "F_KEYTAG ", "F_SECSTAT ", "F_NO_RR ", "F_IPSET ", "F_NOEXTRA "};
 
-void _FTL_new_query(unsigned int flags, char *name, struct all_addr *addr, char *types, int id, char type, const char* file, const int line)
+void _FTL_new_query(const unsigned int flags, const char *name, const struct all_addr *addr,
+                    const char *types, const int id, const char type,
+                    const char* file, const int line)
 {
 	// Don't analyze anything if in PRIVACY_NOSTATS mode
 	if(config.privacylevel >= PRIVACY_NOSTATS)
@@ -38,7 +40,7 @@ void _FTL_new_query(unsigned int flags, char *name, struct all_addr *addr, char
 	lock_shm();
 
 	// Get timestamp
-	time_t querytimestamp = time(NULL);
+	const time_t querytimestamp = time(NULL);
 
 	// Save request time
 	struct timeval request;
@@ -78,7 +80,7 @@ void _FTL_new_query(unsigned int flags, char *name, struct all_addr *addr, char
 
 	// Ensure we have enough space in the queries struct
 	memory_check(QUERIES);
-	int queryID = counters->queries;
+	const int queryID = counters->queries;
 
 	// If domain is "pi.hole" we skip this query
 	if(strcasecmp(name, "pi.hole") == 0)
@@ -111,14 +113,15 @@ void _FTL_new_query(unsigned int flags, char *name, struct all_addr *addr, char
 	const char *proto = (type == UDP) ? "UDP" : "TCP";
 	if(config.debug & DEBUG_QUERIES)
 	{
-		logg("**** new %s %s \"%s\" from %s (ID %i, %s:%i)", proto, types, domainString, clientIP, id, file, line);
+		logg("**** new %s %s \"%s\" from %s (ID %i, FTL %i, %s:%i)",
+		     proto, types, domainString, clientIP, id, queryID, file, line);
 	}
 
 	// Update counters
 	counters->querytype[querytype-1]++;
 
 	// Update overTime
-	unsigned int timeidx = getOverTimeID(querytimestamp);
+	const unsigned int timeidx = getOverTimeID(querytimestamp);
 	overTime[timeidx].querytypedata[querytype-1]++;
 
 	// Skip rest of the analysis if this query is not of type A or AAAA
@@ -134,10 +137,10 @@ void _FTL_new_query(unsigned int flags, char *name, struct all_addr *addr, char
 	}
 
 	// Go through already knows domains and see if it is one of them
-	int domainID = findDomainID(domainString);
+	const int domainID = findDomainID(domainString);
 
 	// Go through already knows clients and see if it is one of them
-	int clientID = findClientID(clientIP, true);
+	const int clientID = findClientID(clientIP, true);
 
 	// Save everything
 	queriesData* query = getQuery(queryID, false);
@@ -220,7 +223,7 @@ void _FTL_new_query(unsigned int flags, char *name, struct all_addr *addr, char
 	unlock_shm();
 }
 
-static int findQueryID(int id)
+static int findQueryID(const int id)
 {
 	// Loop over all queries - we loop in reverse order (start from the most recent query and
 	// continuously walk older queries while trying to find a match. Ideally, we should always
@@ -229,8 +232,8 @@ static int findQueryID(int id)
 	// We iterate from the most recent query down to at most MAXITER queries in the past to avoid
 	// iterating through the entire array of queries
 	// MAX(0, a) is used to return 0 in case a is negative (negative array indices are harmful)
-	int until = MAX(0, counters->queries-MAXITER);
-	int start = MAX(0, counters->queries-1);
+	const int until = MAX(0, counters->queries-MAXITER);
+	const int start = MAX(0, counters->queries-1);
 
 	// Check UUIDs of queries
 	for(int i = start; i >= until; i--)
@@ -244,7 +247,8 @@ static int findQueryID(int id)
 	return -1;
 }
 
-void _FTL_forwarded(unsigned int flags, char *name, struct all_addr *addr, int id, const char* file, const int line)
+void _FTL_forwarded(const unsigned int flags, const char *name, const struct all_addr *addr, const int id,
+                    const char* file, const int line)
 {
 	// Don't analyze anything if in PRIVACY_NOSTATS mode
 	if(config.privacylevel >= PRIVACY_NOSTATS)
@@ -267,7 +271,7 @@ void _FTL_forwarded(unsigned int flags, char *name, struct all_addr *addr, int i
 	if(config.debug & DEBUG_QUERIES) logg("**** forwarded %s to %s (ID %i, %s:%i)", name, forward, id, file, line);
 
 	// Save status and forwardID in corresponding query identified by dnsmasq's ID
-	int queryID = findQueryID(id);
+	const int queryID = findQueryID(id);
 	if(queryID < 0)
 	{
 		// This may happen e.g. if the original query was a PTR query or "pi.hole"
@@ -295,10 +299,10 @@ void _FTL_forwarded(unsigned int flags, char *name, struct all_addr *addr, int i
 
 	// Get ID of forward destination, create new forward destination record
 	// if not found in current data structure
-	int forwardID = findForwardID(forward, true);
+	const int forwardID = findForwardID(forward, true);
 	query->forwardID = forwardID;
 
-	unsigned int timeidx = query->timeidx;
+	const unsigned int timeidx = query->timeidx;
 
 	if(query->status == QUERY_CACHE)
 	{
@@ -361,6 +365,8 @@ void FTL_dnsmasq_reload(void)
 	// *before* clearing the cache and rereading the lists
 	// This is the only hook that is not skipped in PRIVACY_NOSTATS mode
 
+	logg("Received SIGHUP, reloading cache");
+
 	// Called when dnsmasq re-reads its config and hosts files
 	// Reset number of blocked domains
 	counters->gravity = 0;
@@ -382,9 +388,14 @@ void FTL_dnsmasq_reload(void)
 
 	// Reread pihole-FTL.conf to see which debugging flags are set
 	read_debuging_settings(NULL);
+
+	// Print current set of capabilities if requested via debug flag
+	if(config.debug & DEBUG_CAPS)
+		check_capabilities();
 }
 
-void _FTL_reply(unsigned short flags, char *name, struct all_addr *addr, int id, const char* file, const int line)
+void _FTL_reply(const unsigned short flags, const char *name, const struct all_addr *addr, const int id,
+                const char* file, const int line)
 {
 	// Don't analyze anything if in PRIVACY_NOSTATS mode
 	if(config.privacylevel >= PRIVACY_NOSTATS)
@@ -420,7 +431,7 @@ void _FTL_reply(unsigned short flags, char *name, struct all_addr *addr, int id,
 	gettimeofday(&response, 0);
 
 	// Save status in corresponding query identified by dnsmasq's ID
-	int i = findQueryID(id);
+	const int i = findQueryID(id);
 	if(i < 0)
 	{
 		// This may happen e.g. if the original query was "pi.hole"
@@ -440,13 +451,13 @@ void _FTL_reply(unsigned short flags, char *name, struct all_addr *addr, int id,
 	}
 
 	// Determine if this reply is an exact match for the queried domain
-	int domainID = query->domainID;
+	const int domainID = query->domainID;
 
 	// Get domain pointer
 	domainsData* domain = getDomain(domainID, true);
 
 	// Check if this domain matches exactly
-	bool isExactMatch = (name != NULL && strcmp(getstr(domain->domainpos), name) == 0);
+	const bool isExactMatch = (name != NULL && strcmp(getstr(domain->domainpos), name) == 0);
 
 	if((flags & F_CONFIG) && isExactMatch && !query->complete)
 	{
@@ -455,7 +466,7 @@ void _FTL_reply(unsigned short flags, char *name, struct all_addr *addr, int id,
 		counters->unknown--;
 
 		// Get time index
-		unsigned int timeidx = query->timeidx;
+		const unsigned int timeidx = query->timeidx;
 
 		if(strcmp(answer, "(NXDOMAIN)") == 0 ||
 		   strcmp(answer, "0.0.0.0") == 0 ||
@@ -530,12 +541,25 @@ void _FTL_reply(unsigned short flags, char *name, struct all_addr *addr, int id,
 	unlock_shm();
 }
 
-static void detect_blocked_IP(unsigned short flags, const char* answer, int queryID)
+static void detect_blocked_IP(const unsigned short flags, const char* answer, const int queryID)
 {
-	// Skip replies which originated locally. Otherwise, we would count
-	// gravity.list blocked queries as externally blocked.
 	if(flags & F_HOSTS)
 	{
+		// Skip replies which originated locally. Otherwise, we would
+		// count gravity.list blocked queries as externally blocked.
+		if(config.debug & DEBUG_EXTBLOCKED)
+		{
+			logg("Skipping detection of external blocking IP for ID %i as origin is HOSTS", queryID);
+		}
+		return;
+	}
+	else if(flags & F_REVERSE)
+	{
+		// Do not mark responses of PTR requests as externally blocked.
+		if(config.debug & DEBUG_EXTBLOCKED)
+		{
+			logg("Skipping detection of external blocking IP for ID %i as query is PTR", queryID);
+		}
 		return;
 	}
 
@@ -552,7 +576,16 @@ static void detect_blocked_IP(unsigned short flags, const char* answer, int quer
 		 strcmp("146.112.61.109", answer) == 0 ||
 		 strcmp("146.112.61.110", answer) == 0 ))
 	{
-			query_externally_blocked(queryID, QUERY_EXTERNAL_BLOCKED_IP);
+		if(config.debug & DEBUG_EXTBLOCKED)
+		{
+			const queriesData* query = getQuery(queryID, true);
+			const domainsData* domain = getDomain(query->domainID, true);
+			logg("Upstream responded with known blocking page (IPv4), ID %i:\n\t\"%s\" -> \"%s\"",
+			     queryID, getstr(domain->domainpos), answer);
+		}
+
+		// Update status
+		query_externally_blocked(queryID, QUERY_EXTERNAL_BLOCKED_IP);
 	}
 
 	else if(flags & F_IPV6 && answer != NULL &&
@@ -564,7 +597,16 @@ static void detect_blocked_IP(unsigned short flags, const char* answer, int quer
 		 strcmp("::ffff:146.112.61.109", answer) == 0 ||
 		 strcmp("::ffff:146.112.61.110", answer) == 0 ))
 	{
-			query_externally_blocked(queryID, QUERY_EXTERNAL_BLOCKED_IP);
+		if(config.debug & DEBUG_EXTBLOCKED)
+		{
+			const queriesData* query = getQuery(queryID, true);
+			const domainsData* domain = getDomain(query->domainID, true);
+			logg("Upstream responded with known blocking page (IPv6), ID %i:\n\t\"%s\" -> \"%s\"",
+			     queryID, getstr(domain->domainpos), answer);
+		}
+
+		// Update status
+		query_externally_blocked(queryID, QUERY_EXTERNAL_BLOCKED_IP);
 	}
 
 	// If upstream replied with 0.0.0.0 or ::,
@@ -573,23 +615,41 @@ static void detect_blocked_IP(unsigned short flags, const char* answer, int quer
 	else if(flags & F_IPV4 && answer != NULL &&
 		strcmp("0.0.0.0", answer) == 0)
 	{
-			query_externally_blocked(queryID, QUERY_EXTERNAL_BLOCKED_NULL);
+		if(config.debug & DEBUG_EXTBLOCKED)
+		{
+			const queriesData* query = getQuery(queryID, true);
+			const domainsData* domain = getDomain(query->domainID, true);
+			logg("Upstream responded with 0.0.0.0, ID %i:\n\t\"%s\" -> \"%s\"",
+			     queryID, getstr(domain->domainpos), answer);
+		}
+
+		// Update status
+		query_externally_blocked(queryID, QUERY_EXTERNAL_BLOCKED_NULL);
 	}
 
 	else if(flags & F_IPV6 && answer != NULL &&
 		strcmp("::", answer) == 0)
 	{
-			query_externally_blocked(queryID, QUERY_EXTERNAL_BLOCKED_NULL);
+		if(config.debug & DEBUG_EXTBLOCKED)
+		{
+			const queriesData* query = getQuery(queryID, true);
+			const domainsData* domain = getDomain(query->domainID, true);
+			logg("Upstream responded with ::, ID %i:\n\t\"%s\" -> \"%s\"",
+			     queryID, getstr(domain->domainpos), answer);
+		}
+
+		// Update status
+		query_externally_blocked(queryID, QUERY_EXTERNAL_BLOCKED_NULL);
 	}
 }
 
-static void query_externally_blocked(int i, unsigned char status)
+static void query_externally_blocked(const int queryID, const unsigned char status)
 {
 	// Get query pointer
-	queriesData* query = getQuery(i, true);
+	queriesData* query = getQuery(queryID, true);
 
 	// Get time index
-	unsigned int timeidx = query->timeidx;
+	const unsigned int timeidx = query->timeidx;
 
 	// If query is already known to be externally blocked,
 	// then we have nothing to do here
@@ -624,7 +684,8 @@ static void query_externally_blocked(int i, unsigned char status)
 	query->status = status;
 }
 
-void _FTL_cache(unsigned int flags, char *name, struct all_addr *addr, char *arg, int id, const char* file, const int line)
+void _FTL_cache(const unsigned int flags, const char *name, const struct all_addr *addr,
+                const char *arg, const int id, const char* file, const int line)
 {
 	// Don't analyze anything if in PRIVACY_NOSTATS mode
 	if(config.privacylevel >= PRIVACY_NOSTATS)
@@ -696,8 +757,8 @@ void _FTL_cache(unsigned int flags, char *name, struct all_addr *addr, char *arg
 			print_flags(flags);
 		}
 
-		int i = findQueryID(id);
-		if(i < 0)
+		const int queryID = findQueryID(id);
+		if(queryID < 0)
 		{
 			// This may happen e.g. if the original query was a PTR query or "pi.hole"
 			// as we ignore them altogether
@@ -706,7 +767,7 @@ void _FTL_cache(unsigned int flags, char *name, struct all_addr *addr, char *arg
 		}
 
 		// Get query pointer
-		queriesData* query = getQuery(i, true);
+		queriesData* query = getQuery(queryID, true);
 
 		if(query->complete)
 		{
@@ -719,7 +780,7 @@ void _FTL_cache(unsigned int flags, char *name, struct all_addr *addr, char *arg
 		counters->unknown--;
 
 		// Get time index
-		unsigned int timeidx = query->timeidx;
+		const unsigned int timeidx = query->timeidx;
 
 		// Get domain pointer
 		domainsData* domain = getDomain(query->domainID, true);
@@ -734,7 +795,7 @@ void _FTL_cache(unsigned int flags, char *name, struct all_addr *addr, char *arg
 		query->status = requesttype;
 
 		// Detect if returned IP indicates that this query was blocked
-		detect_blocked_IP(flags, dest, i);
+		detect_blocked_IP(flags, dest, queryID);
 
 		// Re-read requesttype as detect_blocked_IP() might have changed it
 		requesttype = query->status;
@@ -763,7 +824,7 @@ void _FTL_cache(unsigned int flags, char *name, struct all_addr *addr, char *arg
 		}
 
 		// Save reply type and update individual reply counters
-		save_reply_type(flags, i, response);
+		save_reply_type(flags, queryID, response);
 
 		// Hereby, this query is now fully determined
 		query->complete = true;
@@ -776,7 +837,7 @@ void _FTL_cache(unsigned int flags, char *name, struct all_addr *addr, char *arg
 	unlock_shm();
 }
 
-void _FTL_dnssec(int status, int id, const char* file, const int line)
+void _FTL_dnssec(const int status, const int id, const char* file, const int line)
 {
 	// Don't analyze anything if in PRIVACY_NOSTATS mode
 	if(config.privacylevel >= PRIVACY_NOSTATS)
@@ -785,8 +846,8 @@ void _FTL_dnssec(int status, int id, const char* file, const int line)
 	// Process DNSSEC result for a domain
 	lock_shm();
 	// Search for corresponding query identified by ID
-	int i = findQueryID(id);
-	if(i < 0)
+	const int queryID = findQueryID(id);
+	if(queryID < 0)
 	{
 		// This may happen e.g. if the original query was an unhandled query type
 		unlock_shm();
@@ -794,7 +855,7 @@ void _FTL_dnssec(int status, int id, const char* file, const int line)
 	}
 
 	// Get query pointer
-	queriesData* query = getQuery(i, true);
+	queriesData* query = getQuery(queryID, true);
 
 	// Debug logging
 	if(config.debug & DEBUG_QUERIES)
@@ -816,7 +877,7 @@ void _FTL_dnssec(int status, int id, const char* file, const int line)
 	unlock_shm();
 }
 
-void _FTL_upstream_error(unsigned int rcode, int id, const char* file, const int line)
+void _FTL_upstream_error(const unsigned int rcode, const int id, const char* file, const int line)
 {
 	// Process upstream errors
 	// Queries with error are those where the RCODE
@@ -829,8 +890,8 @@ void _FTL_upstream_error(unsigned int rcode, int id, const char* file, const int
 	// Process DNSSEC result for a domain
 	lock_shm();
 	// Search for corresponding query identified by ID
-	int i = findQueryID(id);
-	if(i < 0)
+	const int queryID = findQueryID(id);
+	if(queryID < 0)
 	{
 		// This may happen e.g. if the original query was an unhandled query type
 		unlock_shm();
@@ -838,7 +899,7 @@ void _FTL_upstream_error(unsigned int rcode, int id, const char* file, const int
 	}
 
 	// Get query pointer
-	queriesData* query = getQuery(i, true);
+	queriesData* query = getQuery(queryID, true);
 
 	// Translate dnsmasq's rcode into something we can use
 	const char *rcodestr = NULL;
@@ -901,7 +962,7 @@ void _FTL_header_analysis(const unsigned char header4, const unsigned int rcode,
 	lock_shm();
 
 	// Search for corresponding query identified by ID
-	int queryID = findQueryID(id);
+	const int queryID = findQueryID(id);
 	if(queryID < 0)
 	{
 		// This may happen e.g. if the original query was an unhandled query type
@@ -932,7 +993,7 @@ void _FTL_header_analysis(const unsigned char header4, const unsigned int rcode,
 	unlock_shm();
 }
 
-void print_flags(unsigned int flags)
+void print_flags(const unsigned int flags)
 {
 	// Debug function, listing resolver flags in clear text
 	// e.g. "Flags: F_FORWARD F_NEG F_IPV6"
@@ -941,16 +1002,15 @@ void print_flags(unsigned int flags)
 	if(!(config.debug & DEBUG_FLAGS))
 		return;
 
-	unsigned int i;
 	char *flagstr = calloc(256,sizeof(char));
-	for(i = 0; i < sizeof(flags)*8; i++)
+	for(unsigned int i = 0; i < sizeof(flags)*8; i++)
 		if(flags & (1u << i))
 			strcat(flagstr, flagnames[i]);
 	logg("     Flags: %s", flagstr);
 	free(flagstr);
 }
 
-void save_reply_type(unsigned int flags, int queryID, struct timeval response)
+void save_reply_type(const unsigned int flags, const int queryID, const struct timeval response)
 {
 	// Get query pointer
 	queriesData* query = getQuery(queryID, true);
@@ -1079,7 +1139,7 @@ void FTL_fork_and_bind_sockets(struct passwd *ent_pw)
 }
 
 // int cache_inserted, cache_live_freed are defined in dnsmasq/cache.c
-void getCacheInformation(int *sock)
+void getCacheInformation(const int *sock)
 {
 	ssend(*sock,"cache-size: %i\ncache-live-freed: %i\ncache-inserted: %i\n",
 	            daemon->cachesize,
@@ -1095,7 +1155,7 @@ void getCacheInformation(int *sock)
 	// which hasn't been looked up for the longest time is evicted.
 }
 
-void _FTL_forwarding_failed(struct server *server, const char* file, const int line)
+void _FTL_forwarding_failed(const struct server *server, const char* file, const int line)
 {
 	// Don't analyze anything if in PRIVACY_NOSTATS mode
 	if(config.privacylevel >= PRIVACY_NOSTATS)
@@ -1112,7 +1172,7 @@ void _FTL_forwarding_failed(struct server *server, const char* file, const int l
 	// Convert forward to lower case
 	char *forwarddest = strdup(dest);
 	strtolower(forwarddest);
-	int forwardID = findForwardID(forwarddest, false);
+	const int forwardID = findForwardID(forwarddest, false);
 
 	if(config.debug & DEBUG_QUERIES) logg("**** forwarding to %s (ID %i, %s:%i) failed", dest, forwardID, file, line);
 
@@ -1127,7 +1187,7 @@ void _FTL_forwarding_failed(struct server *server, const char* file, const int l
 	return;
 }
 
-static unsigned long __attribute__((const)) converttimeval(struct timeval time)
+static unsigned long __attribute__((const)) converttimeval(const struct timeval time)
 {
 	// Convert time from struct timeval into units
 	// of 10*milliseconds
@@ -1191,8 +1251,8 @@ void rehash(int size);
 // This routine adds one domain to the resolver's cache. Depending on the configured blocking mode it may create
 // a single entry valid for IPv4 & IPv6 or two entries one for IPv4 and one for IPv6.
 // When IPv6 is not available on the machine, we do not add IPv6 cache entries (likewise for IPv4)
-static int add_blocked_domain(struct all_addr *addr4, struct all_addr *addr6, bool has_IPv4, bool has_IPv6,
-                              char *domain, int len, struct crec **rhash, int hashsz, unsigned int index)
+static int add_blocked_domain(struct all_addr *addr4, struct all_addr *addr6, const bool has_IPv4, const bool has_IPv6,
+                              const char *domain, const int len, struct crec **rhash, int hashsz, unsigned int index)
 {
 	int name_count = 0;
 	struct crec *cache4,*cache6;
@@ -1246,7 +1306,7 @@ static int add_blocked_domain(struct all_addr *addr4, struct all_addr *addr6, bo
 // Add a single domain to resolver's cache. This respects the configured blocking mode
 // Note: This routine is meant for adding a single domain at a time. It should not be
 //       invoked for batch processing
-static void block_single_domain_regex(char *domain)
+static void block_single_domain_regex(const char *domain)
 {
 	struct all_addr addr4 = {{{ 0 }}}, addr6 = {{{ 0 }}};
 	bool has_IPv4 = false, has_IPv6 = false;
@@ -1261,7 +1321,7 @@ static void block_single_domain_regex(char *domain)
 	return;
 }
 
-int FTL_listsfile(char* filename, unsigned int index, FILE *f, int cache_size, struct crec **rhash, int hashsz)
+int FTL_listsfile(const char* filename, unsigned int index, FILE *f, int cache_size, struct crec **rhash, int hashsz)
 {
 	int name_count = cache_size;
 	int added = 0;
diff --git a/dnsmasq_interface.h b/dnsmasq_interface.h
index 51b76af9..87a65469 100644
--- a/dnsmasq_interface.h
+++ b/dnsmasq_interface.h
@@ -12,29 +12,29 @@ extern unsigned char* pihole_privacylevel;
 enum { TCP, UDP };
 
 #define FTL_new_query(flags, name, addr, types, id, type) _FTL_new_query(flags, name, addr, types, id, type, __FILE__, __LINE__)
-void _FTL_new_query(unsigned int flags, char *name, struct all_addr *addr, char *types, int id, char type, const char* file, const int line);
+void _FTL_new_query(const unsigned int flags, const char *name, const struct all_addr *addr, const char *types, const int id, const char type, const char* file, const int line);
 
 #define FTL_forwarded(flags, name, addr, id) _FTL_forwarded(flags, name, addr, id, __FILE__, __LINE__)
-void _FTL_forwarded(unsigned int flags, char *name, struct all_addr *addr, int id, const char* file, const int line);
+void _FTL_forwarded(const unsigned int flags, const char *name, const struct all_addr *addr, const int id, const char* file, const int line);
 
 #define FTL_reply(flags, name, addr, id) _FTL_reply(flags, name, addr, id, __FILE__, __LINE__)
-void _FTL_reply(unsigned short flags, char *name, struct all_addr *addr, int id, const char* file, const int line);
+void _FTL_reply(const unsigned short flags, const char *name, const struct all_addr *addr, const int id, const char* file, const int line);
 
 #define FTL_cache(flags, name, addr, arg, id) _FTL_cache(flags, name, addr, arg, id, __FILE__, __LINE__)
-void _FTL_cache(unsigned int flags, char *name, struct all_addr *addr, char * arg, int id, const char* file, const int line);
+void _FTL_cache(const unsigned int flags, const char *name, const struct all_addr *addr, const char * arg, const int id, const char* file, const int line);
 
 #define FTL_dnssec(status, id) _FTL_dnssec(status, id, __FILE__, __LINE__)
-void _FTL_dnssec(int status, int id, const char* file, const int line);
+void _FTL_dnssec(const int status, const int id, const char* file, const int line);
 
 #define FTL_header_analysis(header4, rcode, id) _FTL_header_analysis(header4, rcode, id, __FILE__, __LINE__)
-void _FTL_header_analysis(unsigned char header4, unsigned int rcode, int id, const char* file, const int line);
+void _FTL_header_analysis(const unsigned char header4, const unsigned int rcode, const int id, const char* file, const int line);
 
 #define FTL_forwarding_failed(server) _FTL_forwarding_failed(server, __FILE__, __LINE__)
-void _FTL_forwarding_failed(struct server *server, const char* file, const int line);
+void _FTL_forwarding_failed(const struct server *server, const char* file, const int line);
 
 #define FTL_upstream_error(rcode, id) _FTL_upstream_error(rcode, id, __FILE__, __LINE__)
-void _FTL_upstream_error(unsigned int rcode, int id, const char* file, const int line);
+void _FTL_upstream_error(const unsigned int rcode, const int id, const char* file, const int line);
 
 void FTL_dnsmasq_reload(void);
 void FTL_fork_and_bind_sockets(struct passwd *ent_pw);
-int FTL_listsfile(char* filename, unsigned int index, FILE *f, int cache_size, struct crec **rhash, int hashsz);
+int FTL_listsfile(const char* filename, unsigned int index, FILE *f, int cache_size, struct crec **rhash, int hashsz);
diff --git a/gc.c b/gc.c
index 9de255e5..08dadf4a 100644
--- a/gc.c
+++ b/gc.c
@@ -44,12 +44,11 @@ void *GC_thread(void *val)
 
 			if(config.debug & DEBUG_GC) timer_start(GC_TIMER);
 
-			long int i;
 			int removed = 0;
 			if(config.debug & DEBUG_GC) logg("GC starting, mintime: %lu %s", mintime, ctime(&mintime));
 
 			// Process all queries
-			for(i=0; i < counters->queries; i++)
+			for(long int i=0; i < counters->queries; i++)
 			{
 				queriesData* query = getQuery(i, true);
 				// Test if this query is too new
@@ -61,7 +60,7 @@ void *GC_thread(void *val)
 				client->count--;
 
 				// Adjust total counters and total over time data
-				int timeidx = query->timeidx;
+				const int timeidx = query->timeidx;
 				overTime[timeidx].total--;
 				// Adjust corresponding overTime counters
 				client->overTime[timeidx]--;
@@ -169,7 +168,8 @@ void *GC_thread(void *val)
 			// Determine if overTime memory needs to get moved
 			moveOverTimeMemory(mintime);
 
-			if(config.debug & DEBUG_GC) logg("Notice: GC removed %i queries (took %.2f ms)", removed, timer_elapsed_msec(GC_TIMER));
+			if(config.debug & DEBUG_GC)
+				logg("Notice: GC removed %i queries (took %.2f ms)", removed, timer_elapsed_msec(GC_TIMER));
 
 			// Release thread lock
 			unlock_shm();
diff --git a/grep.c b/grep.c
index 09cba3c8..628940a3 100644
--- a/grep.c
+++ b/grep.c
@@ -105,7 +105,7 @@ int countlineswith(const char* str, const char* fname)
 
 void check_blocking_status(void)
 {
-	char* blocking = read_setupVarsconf("BLOCKING_ENABLED");
+	const char* blocking = read_setupVarsconf("BLOCKING_ENABLED");
 	const char* message;
 
 	if(blocking == NULL || getSetupVarsBool(blocking))
diff --git a/log.c b/log.c
index fe71c417..71170537 100644
--- a/log.c
+++ b/log.c
@@ -11,8 +11,8 @@
 #include "FTL.h"
 #include "version.h"
 
-pthread_mutex_t lock;
-FILE *logfile = NULL;
+static pthread_mutex_t lock;
+static FILE *logfile = NULL;
 
 static void close_FTL_log(void)
 {
@@ -20,7 +20,7 @@ static void close_FTL_log(void)
 		fclose(logfile);
 }
 
-void open_FTL_log(bool test)
+void open_FTL_log(const bool test)
 {
 	if(test)
 	{
@@ -52,11 +52,11 @@ void open_FTL_log(bool test)
 
 static void get_timestr(char *timestring)
 {
-	time_t t = time(NULL);
-	struct tm tm = *localtime(&t);
+	const time_t t = time(NULL);
+	const struct tm tm = *localtime(&t);
 	struct timeval tv;
 	gettimeofday(&tv, NULL);
-	int millisec = tv.tv_usec/1000;
+	const int millisec = tv.tv_usec/1000;
 
 	sprintf(timestring,"%d-%02d-%02d %02d:%02d:%02d.%03i", tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec, millisec);
 }
@@ -72,7 +72,7 @@ void __attribute__ ((format (gnu_printf, 1, 2))) logg(const char *format, ...)
 
 	// Get and log PID of current process to avoid ambiguities when more than one
 	// pihole-FTL instance is logging into the same file
-	long pid = (long)getpid();
+	const long pid = (long)getpid();
 
 	// Print to stdout before writing to file
 	if(!daemonmode)
@@ -108,7 +108,7 @@ void __attribute__ ((format (gnu_printf, 1, 2))) logg(const char *format, ...)
 	pthread_mutex_unlock(&lock);
 }
 
-void format_memory_size(char *prefix, unsigned long int bytes, double *formated)
+void format_memory_size(char *prefix, const unsigned long int bytes, double *formated)
 {
 	int i;
 	*formated = bytes;
@@ -124,11 +124,6 @@ void format_memory_size(char *prefix, unsigned long int bytes, double *formated)
 	strcpy(prefix, prefixes[i]);
 }
 
-void logg_struct_resize(const char* str, int to, int step)
-{
-	logg("Notice: Increasing %s struct size from %i to %i", str, (to-step), to);
-}
-
 void log_counter_info(void)
 {
 	logg(" -> Total DNS queries: %i", counters->queries);
@@ -141,7 +136,7 @@ void log_counter_info(void)
 	logg(" -> Known forward destinations: %i", counters->forwarded);
 }
 
-void log_FTL_version(bool crashreport)
+void log_FTL_version(const bool crashreport)
 {
 	logg("FTL branch: %s", GIT_BRANCH);
 	logg("FTL version: %s", GIT_TAG);
diff --git a/memory.c b/memory.c
index 1bed49fb..8c240ebb 100644
--- a/memory.c
+++ b/memory.c
@@ -44,7 +44,7 @@ ConfigStruct config;
 // not be protected by our (error logging) functions!
 
 #undef strdup
-char* __attribute__((malloc)) FTLstrdup(const char *src, const char * file, const char * function, int line)
+char* __attribute__((malloc)) FTLstrdup(const char *src, const char * file, const char * function, const int line)
 {
 	// The FTLstrdup() function returns a pointer to a new string which is a
 	// duplicate of the string s. Memory for the new string is obtained with
@@ -54,7 +54,7 @@ char* __attribute__((malloc)) FTLstrdup(const char *src, const char * file, cons
 		logg("WARN: Trying to copy a NULL string in %s() (%s:%i)", function, file, line);
 		return NULL;
 	}
-	size_t len = strlen(src);
+	const size_t len = strlen(src);
 	char *dest = calloc(len+1, sizeof(char));
 	if(dest == NULL)
 	{
@@ -69,7 +69,7 @@ char* __attribute__((malloc)) FTLstrdup(const char *src, const char * file, cons
 }
 
 #undef calloc
-void* __attribute__((malloc)) __attribute__((alloc_size(1,2))) FTLcalloc(size_t nmemb, size_t size, const char * file, const char * function, int line)
+void* __attribute__((malloc)) __attribute__((alloc_size(1,2))) FTLcalloc(const size_t nmemb, const size_t size, const char * file, const char * function, const int line)
 {
 	// The FTLcalloc() function allocates memory for an array of nmemb elements
 	// of size bytes each and returns a pointer to the allocated memory. The
@@ -85,7 +85,7 @@ void* __attribute__((malloc)) __attribute__((alloc_size(1,2))) FTLcalloc(size_t
 }
 
 #undef realloc
-void __attribute__((alloc_size(2))) *FTLrealloc(void *ptr_in, size_t size, const char * file, const char * function, int line)
+void __attribute__((alloc_size(2))) *FTLrealloc(void *ptr_in, const size_t size, const char * file, const char * function, const int line)
 {
 	// The FTLrealloc() function changes the size of the memory block pointed to
 	// by ptr to size bytes. The contents will be unchanged in the range from
@@ -106,7 +106,7 @@ void __attribute__((alloc_size(2))) *FTLrealloc(void *ptr_in, size_t size, const
 }
 
 #undef free
-void FTLfree(void *ptr, const char * file, const char * function, int line)
+void FTLfree(void *ptr, const char * file, const char * function, const int line)
 {
 	// The free() function frees the memory space pointed  to  by  ptr,  which
 	// must  have  been  returned by a previous call to malloc(), calloc(), or
diff --git a/msgpack.c b/msgpack.c
index 58cc7ee9..07b61341 100644
--- a/msgpack.c
+++ b/msgpack.c
@@ -11,19 +11,19 @@
 #include "FTL.h"
 #include "api.h"
 
-void pack_eom(int sock) {
+void pack_eom(const int sock) {
 	// This byte is explicitly never used in the MessagePack spec, so it is perfect to use as an EOM for this API.
 	uint8_t eom = 0xc1;
 	swrite(sock, &eom, sizeof(eom));
 }
 
-static void pack_basic(int sock, uint8_t format, void *value, size_t size) {
+static void pack_basic(const int sock, const uint8_t format, const void *value, const size_t size) {
 	swrite(sock, &format, sizeof(format));
 	swrite(sock, value, size);
 }
 
-static uint64_t __attribute__((const)) leToBe64(uint64_t value) {
-	char *ptr = (char *) &value;
+static uint64_t __attribute__((const)) leToBe64(const uint64_t value) {
+	const char *ptr = (char *) &value;
 	uint32_t part1, part2;
 
 	// Copy the two halves of the 64 bit input into uint32_t's so we can use htonl
@@ -38,26 +38,26 @@ static uint64_t __attribute__((const)) leToBe64(uint64_t value) {
 	return (uint64_t) part1 << 32 | part2;
 }
 
-void pack_bool(int sock, bool value) {
+void pack_bool(const int sock, const bool value) {
 	uint8_t packed = (uint8_t) (value ? 0xc3 : 0xc2);
 	swrite(sock, &packed, sizeof(packed));
 }
 
-void pack_uint8(int sock, uint8_t value) {
+void pack_uint8(const int sock, const uint8_t value) {
 	pack_basic(sock, 0xcc, &value, sizeof(value));
 }
 
-void pack_uint64(int sock, uint64_t value) {
-	uint64_t bigEValue = leToBe64(value);
+void pack_uint64(const int sock, const uint64_t value) {
+	const uint64_t bigEValue = leToBe64(value);
 	pack_basic(sock, 0xcf, &bigEValue, sizeof(bigEValue));
 }
 
-void pack_int32(int sock, int32_t value) {
-	uint32_t bigEValue = htonl((uint32_t) value);
+void pack_int32(const int sock, const int32_t value) {
+	const uint32_t bigEValue = htonl((uint32_t) value);
 	pack_basic(sock, 0xd2, &bigEValue, sizeof(bigEValue));
 }
 
-void pack_int64(int sock, int64_t value) {
+void pack_int64(const int sock, const int64_t value) {
 	// Need to use memcpy to do a direct copy without reinterpreting the bytes (making negatives into positives).
 	// It should get optimized away.
 	uint64_t bigEValue;
@@ -66,7 +66,7 @@ void pack_int64(int sock, int64_t value) {
 	pack_basic(sock, 0xd3, &bigEValue, sizeof(bigEValue));
 }
 
-void pack_float(int sock, float value) {
+void pack_float(const int sock, const float value) {
 	// Need to use memcpy to do a direct copy without reinterpreting the bytes. It should get optimized away.
 	uint32_t bigEValue;
 	memcpy(&bigEValue, &value, sizeof(bigEValue));
@@ -75,16 +75,16 @@ void pack_float(int sock, float value) {
 }
 
 // Return true if successful
-bool pack_fixstr(int sock, const char *string) {
+bool pack_fixstr(const int sock, const char *string) {
 	// Make sure that the length is less than 32
-	size_t length = strlen(string);
+	const size_t length = strlen(string);
 
 	if(length >= 32) {
 		logg("Tried to send a fixstr longer than 31 bytes!");
 		return false;
 	}
 
-	uint8_t format = (uint8_t) (0xA0 | length);
+	const uint8_t format = (uint8_t) (0xA0 | length);
 	swrite(sock, &format, sizeof(format));
 	swrite(sock, string, length);
 
@@ -92,27 +92,27 @@ bool pack_fixstr(int sock, const char *string) {
 }
 
 // Return true if successful
-bool pack_str32(int sock, const char *string) {
+bool pack_str32(const int sock, const char *string) {
 	// Make sure that the length is less than 4294967296
-	size_t length = strlen(string);
+	const size_t length = strlen(string);
 
 	if(length >= 2147483648u) {
 		logg("Tried to send a str32 longer than 2147483647 bytes!");
 		return false;
 	}
 
-	uint8_t format = 0xdb;
+	const uint8_t format = 0xdb;
 	swrite(sock, &format, sizeof(format));
-	uint32_t bigELength = htonl((uint32_t) length);
+	const uint32_t bigELength = htonl((uint32_t) length);
 	swrite(sock, &bigELength, sizeof(bigELength));
 	swrite(sock, string, length);
 
 	return true;
 }
 
-void pack_map16_start(int sock, uint16_t length) {
-	uint8_t format = 0xde;
+void pack_map16_start(const int sock, const uint16_t length) {
+	const uint8_t format = 0xde;
 	swrite(sock, &format, sizeof(format));
-	uint16_t bigELength = htons(length);
+	const uint16_t bigELength = htons(length);
 	swrite(sock, &bigELength, sizeof(bigELength));
 }
diff --git a/networktable.c b/networktable.c
index e47a496c..e4474359 100644
--- a/networktable.c
+++ b/networktable.c
@@ -65,7 +65,7 @@ void parse_arp_cache(void)
 	char * linebuffer = NULL;
 	size_t linebuffersize = 0;
 	char ip[100], mask[100], hwaddr[100], iface[100];
-	int type, flags, entries = 0;
+	unsigned int type, flags, entries = 0;
 	time_t now = time(NULL);
 
 	// Start collecting database commands
@@ -102,7 +102,7 @@ void parse_arp_cache(void)
 		}
 
 		// Perform SQL query
-		int dbID = db_query_int(querystr);
+		const int dbID = db_query_int(querystr);
 		free(querystr);
 
 		if(dbID == DB_FAILED)
@@ -122,6 +122,8 @@ void parse_arp_cache(void)
 		// Get client pointer
 		clientsData* client = NULL;
 
+		// This client is known (by its IP address) to pihole-FTL if
+		// findClientID() returned a non-negative index
 		if(clientID >= 0)
 		{
 			client = getClient(clientID, true);
@@ -184,7 +186,8 @@ void parse_arp_cache(void)
 	unlock_shm();
 
 	// Debug logging
-	if(config.debug & DEBUG_ARP) logg("ARP table processing (%i entries) took %.1f ms", entries, timer_elapsed_msec(ARP_TIMER));
+	if(config.debug & DEBUG_ARP)
+		logg("ARP table processing (%i entries) took %.1f ms", entries, timer_elapsed_msec(ARP_TIMER));
 
 	// Close file handle
 	fclose(arpfp);
@@ -199,13 +202,15 @@ static char* getMACVendor(const char* hwaddr)
 	if(stat(FTLfiles.macvendordb, &st) != 0)
 	{
 		// File does not exist
-		if(config.debug & DEBUG_ARP) logg("getMACVenor(%s): %s does not exist", hwaddr, FTLfiles.macvendordb);
+		if(config.debug & DEBUG_ARP)
+			logg("getMACVenor(%s): %s does not exist", hwaddr, FTLfiles.macvendordb);
 		return strdup("");
 	}
 	else if(strlen(hwaddr) != 17)
 	{
 		// MAC address is incomplete
-		if(config.debug & DEBUG_ARP) logg("getMACVenor(%s): MAC invalid (length %zu)", hwaddr, strlen(hwaddr));
+		if(config.debug & DEBUG_ARP)
+			logg("getMACVenor(%s): MAC invalid (length %zu)", hwaddr, strlen(hwaddr));
 		return strdup("");
 	}
 
@@ -269,7 +274,8 @@ void updateMACVendorRecords()
 	if(stat(FTLfiles.macvendordb, &st) != 0)
 	{
 		// File does not exist
-		if(config.debug & DEBUG_ARP) logg("updateMACVendorRecords(): %s does not exist", FTLfiles.macvendordb);
+		if(config.debug & DEBUG_ARP)
+			logg("updateMACVendorRecords(): %s does not exist", FTLfiles.macvendordb);
 		return;
 	}
 
diff --git a/overTime.c b/overTime.c
index fa654229..6353bc94 100644
--- a/overTime.c
+++ b/overTime.c
@@ -16,7 +16,7 @@
  * @param index The overTime slot index
  * @param timestamp The timestamp of the slot
  */
-static void initSlot(unsigned int index, time_t timestamp)
+static void initSlot(const unsigned int index, const time_t timestamp)
 {
 	// Possible debug printing
 	if(config.debug & DEBUG_OVERTIME)
@@ -77,10 +77,10 @@ unsigned int getOverTimeID(time_t timestamp)
 	timestamp += OVERTIME_INTERVAL/2;
 
 	// Get timestamp of first interval
-	time_t firstTimestamp = overTime[0].timestamp;
+	const time_t firstTimestamp = overTime[0].timestamp;
 
 	// Compute overTime ID
-	int id = (int) ((timestamp - firstTimestamp) / OVERTIME_INTERVAL);
+	const int id = (int) ((timestamp - firstTimestamp) / OVERTIME_INTERVAL);
 
 	// Check bounds manually
 	if(id < 0)
@@ -106,9 +106,9 @@ unsigned int getOverTimeID(time_t timestamp)
 }
 
 // This routine is called by garbage collection to rearrange the overTime structure for the next hour
-void moveOverTimeMemory(time_t mintime)
+void moveOverTimeMemory(const time_t mintime)
 {
-	time_t oldestOverTimeIS = overTime[0].timestamp;
+	const time_t oldestOverTimeIS = overTime[0].timestamp;
 	// Shift SHOULD timestemp into the future by the amount GC is running earlier
 	time_t oldestOverTimeSHOULD = mintime;
 
@@ -118,10 +118,10 @@ void moveOverTimeMemory(time_t mintime)
 
 	// Calculate the number of slots to be garbage collected, which is also the
 	// ID of the slot to move to the zero position
-	unsigned int moveOverTime = (unsigned int) ((oldestOverTimeSHOULD - oldestOverTimeIS) / OVERTIME_INTERVAL);
+	const unsigned int moveOverTime = (unsigned int) ((oldestOverTimeSHOULD - oldestOverTimeIS) / OVERTIME_INTERVAL);
 
 	// The number of slots which will be moved (not garbage collected)
-	unsigned int remainingSlots = OVERTIME_SLOTS - moveOverTime;
+	const unsigned int remainingSlots = OVERTIME_SLOTS - moveOverTime;
 
 	if(config.debug & DEBUG_OVERTIME)
 	{
@@ -176,7 +176,7 @@ void moveOverTimeMemory(time_t mintime)
 		for(unsigned int timeidx = remainingSlots; timeidx < OVERTIME_SLOTS ; timeidx++)
 		{
 			// This slot is OVERTIME_INTERVAL seconds after the previous slot
-			time_t timestamp = overTime[timeidx-1].timestamp + OVERTIME_INTERVAL;
+			const time_t timestamp = overTime[timeidx-1].timestamp + OVERTIME_INTERVAL;
 			initSlot(timeidx, timestamp);
 		}
 	}
diff --git a/regex.c b/regex.c
index 79557b96..353a975e 100644
--- a/regex.c
+++ b/regex.c
@@ -17,22 +17,22 @@ static bool *regexconfigured = NULL;
 static char **regexbuffer = NULL;
 static whitelistStruct whitelist = { NULL, 0 };
 
-static void log_regex_error(const char *where, int errcode, int index)
+static void log_regex_error(const char *where, const int errcode, const int index)
 {
 	// Regex failed for some reason (probably user syntax error)
 	// Get error string and log it
-	size_t length = regerror(errcode, &regex[index], NULL, 0);
+	const size_t length = regerror(errcode, &regex[index], NULL, 0);
 	char *buffer = calloc(length,sizeof(char));
 	(void) regerror (errcode, &regex[index], buffer, length);
 	logg("ERROR %s regex on line %i: %s (%i)", where, index+1, buffer, errcode);
 	free(buffer);
 }
 
-static bool init_regex(const char *regexin, int index)
+static bool init_regex(const char *regexin, const int index)
 {
 	// compile regular expressions into data structures that
 	// can be used with regexec to match against a string
-	int errcode = regcomp(&regex[index], regexin, REG_EXTENDED);
+	const int errcode = regcomp(&regex[index], regexin, REG_EXTENDED);
 	if(errcode != 0)
 	{
 		log_regex_error("compiling", errcode, index);
@@ -47,7 +47,7 @@ static bool init_regex(const char *regexin, int index)
 	return true;
 }
 
-bool __attribute__((pure)) in_whitelist(char *domain)
+bool __attribute__((pure)) in_whitelist(const char *domain)
 {
 	bool found = false;
 	for(int i=0; i < whitelist.count; i++)
@@ -77,14 +77,13 @@ static void free_whitelist_domains(void)
 	}
 }
 
-bool match_regex(char *input)
+bool match_regex(const char *input)
 {
-	int index;
 	bool matched = false;
 
 	// Start matching timer
 	timer_start(REGEX_TIMER);
-	for(index = 0; index < num_regex; index++)
+	for(int index = 0; index < num_regex; index++)
 	{
 		// Only check regex which have been successfully compiled
 		if(!regexconfigured[index])
diff --git a/resolve.c b/resolve.c
index bfe4beba..14818124 100644
--- a/resolve.c
+++ b/resolve.c
@@ -11,15 +11,7 @@
 #include "FTL.h"
 #include "shmem.h"
 
-// Resolve new client and upstream server host names
-// once every minute
-#define RESOLVE_INTERVAL 60
-
-// Re-resolve client names
-// once every hour
-#define RERESOLVE_INTERVAL 3600
-
-static const char *resolveHostname(const char *addr)
+static char *resolveHostname(const char *addr)
 {
 	// Get host name
 	struct hostent *he = NULL;
@@ -71,63 +63,109 @@ static const char *resolveHostname(const char *addr)
 	return hostname;
 }
 
-// Resolve client host names
-void resolveClients(bool onlynew)
+// Resolve upstream destination host names
+static size_t resolveAndAddHostname(size_t ippos, size_t oldnamepos)
 {
-	for(int clientID = 0; clientID < counters->clients; clientID++)
+	// Get IP and host name strings
+	lock_shm();
+	const char* ipaddr = getstr(ippos);
+	const char* oldname = getstr(oldnamepos);
+	unlock_shm();
+
+	// 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);
+
+	// Only store new newname if it is valid and differs from oldname
+	// We do not need to check for oldname == NULL as names are
+	// always initialized with an empty string at position 0
+	if(newname != NULL && strcmp(oldname, newname) != 0)
+	{
+		lock_shm();
+		size_t newnamepos = addstr(newname);
+		// newname has already been checked against NULL
+		// so we can safely free it
+		free(newname);
+		unlock_shm();
+		return newnamepos;
+	}
+	else if(config.debug & DEBUG_SHMEM)
+	{
+		// Debugging output
+		logg("Not adding \"%s\" to buffer (unchanged)", oldname);
+	}
+
+	// Not changed, return old namepos
+	return oldnamepos;
+}
+
+// Resolve client host names
+void resolveClients(const bool onlynew)
+{
+	// Lock counter access here, we use a copy in the following loop
+	lock_shm();
+	int clientscount = counters->clients;
+	unlock_shm();
+	for(int clientID = 0; clientID < clientscount; clientID++)
 	{
 		// Get client pointer
 		clientsData* client = getClient(clientID, true);
 
-		// If onlynew flag is set, we will only resolve new clients
-		// If not, we will try to re-resolve all known clients
-		if(onlynew && !client->new)
-			continue;
-
-		// Lock data when obtaining IP of this client
+		// Memory access needs to get locked
 		lock_shm();
-		const char* ipaddr = getstr(client->ippos);
+		bool newflag = client->new;
+		size_t ippos = client->ippos;
+		size_t oldnamepos = client->namepos;
 		unlock_shm();
 
-		// Important: Don't hold a lock while resolving as the main thread
-		// (dnsmasq) needs to be operable during the call to resolveHostname()
-		const char* hostname = resolveHostname(ipaddr);
+		// If onlynew flag is set, we will only resolve new clients
+		// If not, we will try to re-resolve all known clients
+		if(onlynew && !newflag)
+			continue;
+
+		// Obtain/update hostname of this client
+		size_t newnamepos = resolveAndAddHostname(ippos, oldnamepos);
 
-		// Finally, lock data when storing obtained hostname
 		lock_shm();
-		client->namepos = addstr(hostname);
+		// Store obtained host name (may be unchanged)
+		client->namepos = newnamepos;
+		// Mark entry as not new
 		client->new = false;
 		unlock_shm();
 	}
 }
 
 // Resolve upstream destination host names
-void resolveForwardDestinations(bool onlynew)
+void resolveForwardDestinations(const bool onlynew)
 {
-	int forwardID;
-	for(forwardID = 0; forwardID < counters->forwarded; forwardID++)
+	// Lock counter access here, we use a copy in the following loop
+	lock_shm();
+	int forwardedcount = counters->forwarded;
+	unlock_shm();
+	for(int forwardID = 0; forwardID < forwardedcount; forwardID++)
 	{
 		// Get forward pointer
 		forwardedData* forward = getForward(forwardID, true);
 
-		// If onlynew flag is set, we will only resolve new upstream destinations
-		// If not, we will try to re-resolve all known upstream destinations
-		if(onlynew && !forward->new)
-			continue;
-
-		// Lock data when obtaining IP of this forward destination
+		// Memory access needs to get locked
 		lock_shm();
-		const char* ipaddr = getstr(forward->ippos);
+		bool newflag = forward->new;
+		size_t ippos = forward->ippos;
+		size_t oldnamepos = forward->namepos;
 		unlock_shm();
 
+		// If onlynew flag is set, we will only resolve new upstream destinations
+		// If not, we will try to re-resolve all known upstream destinations
+		if(onlynew && !newflag)
+			continue;
 
-		// Important: Don't hold a lock while resolving as the main thread
-		// (dnsmasq) needs to be operable during the call to resolveHostname()
-		const char* hostname = resolveHostname(ipaddr);
+		// Obtain/update hostname of this client
+		size_t newnamepos = resolveAndAddHostname(ippos, oldnamepos);
 
-		// Finally, lock data when storing obtained hostname
 		lock_shm();
-		forward->namepos = addstr(hostname);
+		// Store obtained host name (may be unchanged)
+		forward->namepos = newnamepos;
+		// Mark entry as not new
 		forward->new = false;
 		unlock_shm();
 	}
diff --git a/routines.h b/routines.h
index db286e15..45370413 100644
--- a/routines.h
+++ b/routines.h
@@ -9,36 +9,35 @@
 *  Please see LICENSE file for your rights under this license. */
 
 void go_daemon(void);
-void timer_start(int i);
-double timer_elapsed_msec(int i);
-void sleepms(int milliseconds);
+void timer_start(const int i);
+double timer_elapsed_msec(const int i);
+void sleepms(const int milliseconds);
 void savepid(void);
 char * getUserName(void);
 void removepid(void);
 
-void open_FTL_log(bool test);
+void open_FTL_log(const bool test);
 void logg(const char* format, ...) __attribute__ ((format (gnu_printf, 1, 2)));
-void logg_struct_resize(const char* str, int to, int step);
 void log_counter_info(void);
 void format_memory_size(char *prefix, unsigned long int bytes, double *formated);
 void log_FTL_version(bool crashreport);
 
 // datastructure.c
 void strtolower(char *str);
-int findForwardID(const char * forward, bool count);
+int findForwardID(const char * forward, const bool count);
 int findDomainID(const char *domain);
-int findClientID(const char *client, bool addNew);
+int findClientID(const char *client, const bool count);
 bool isValidIPv4(const char *addr);
 bool isValidIPv6(const char *addr);
-const char *getDomainString(int queryID);
-const char *getClientIPString(int queryID);
-const char *getClientNameString(int queryID);
+const char *getDomainString(const int queryID);
+const char *getClientIPString(const int queryID);
+const char *getClientNameString(const int queryID);
 
 void close_telnet_socket(void);
 void close_unix_socket(void);
-void seom(int sock);
-void ssend(int sock, const char *format, ...) __attribute__ ((format (gnu_printf, 2, 3)));
-void swrite(int sock, const void* value, size_t size);
+void seom(const int sock);
+void ssend(const int sock, const char *format, ...) __attribute__ ((format (gnu_printf, 2, 3)));
+void swrite(const int sock, const void* value, const size_t size);
 void *telnet_listening_thread_IPv4(void *args);
 void *telnet_listening_thread_IPv6(void *args);
 
@@ -48,7 +47,6 @@ void bind_sockets(void);
 
 void process_request(const char *client_message, int *sock);
 bool command(const char *client_message, const char* cmd) __attribute__((pure));
-bool matchesEndpoint(char *client_message, const char *cmd);
 
 // grep.c
 int countlines(const char* fname);
@@ -84,7 +82,7 @@ void *DB_thread(void *val);
 int get_number_of_queries_in_DB(void);
 void save_to_DB(void);
 void read_data_from_DB(void);
-bool db_set_FTL_property(unsigned int ID, int value);
+bool db_set_FTL_property(const unsigned int ID, const int value);
 bool dbquery(const char *format, ...);
 bool dbopen(void);
 void dbclose(void);
@@ -92,11 +90,11 @@ int db_query_int(const char*);
 void SQLite3LogCallback(void *pArg, int iErrCode, const char *zMsg);
 
 // memory.c
-void memory_check(int which);
-char *FTLstrdup(const char *src, const char *file, const char *function, int line) __attribute__((malloc));
-void *FTLcalloc(size_t nmemb, size_t size, const char *file, const char *function, int line) __attribute__((malloc)) __attribute__((alloc_size(1,2)));
-void *FTLrealloc(void *ptr_in, size_t size, const char *file, const char *function, int line) __attribute__((alloc_size(2)));
-void FTLfree(void *ptr, const char* file, const char *function, int line);
+void memory_check(const int which);
+char *FTLstrdup(const char *src, const char *file, const char *function, const int line) __attribute__((malloc));
+void *FTLcalloc(size_t nmemb, size_t size, const char *file, const char *function, const int line) __attribute__((malloc)) __attribute__((alloc_size(1,2)));
+void *FTLrealloc(void *ptr_in, size_t size, const char *file, const char *function, const int line) __attribute__((alloc_size(2)));
+void FTLfree(void *ptr, const char* file, const char *function, const int line);
 
 int main_dnsmasq(int argc, const char ** argv);
 
@@ -105,27 +103,27 @@ void handle_signals(void);
 
 // resolve.c
 void *DNSclient_thread(void *val);
-void resolveClients(bool onlynew);
-void resolveForwardDestinations(bool onlynew);
+void resolveClients(const bool onlynew);
+void resolveForwardDestinations(const bool onlynew);
 
 // regex.c
-bool match_regex(char *input);
+bool match_regex(const char *input);
 void free_regex(void);
 void read_regex_from_file(void);
-bool in_whitelist(char *domain) __attribute__((pure));
+bool in_whitelist(const char *domain) __attribute__((pure));
 
 // shmem.c
 bool init_shmem(void);
 void destroy_shmem(void);
 size_t addstr(const char *str);
-const char *getstr(size_t pos);
-void *enlarge_shmem_struct(char type);
+const char *getstr(const size_t pos);
+void *enlarge_shmem_struct(const char type);
 
 /**
  * Create a new overTime client shared memory block.
  * This also updates `overTimeClientData`.
  */
-void newOverTimeClient(int clientID);
+void newOverTimeClient(const int clientID);
 
 /**
  * Add a new overTime slot to each overTime client shared memory block.
@@ -135,7 +133,7 @@ void addOverTimeClientSlot(void);
 
 // overTime.c
 void initOverTime(void);
-unsigned int getOverTimeID(time_t timestamp);
+unsigned int getOverTimeID(const time_t timestamp);
 
 /**
  * Move the overTime slots so the oldest interval starts with mintime. The time
@@ -143,7 +141,7 @@ unsigned int getOverTimeID(time_t timestamp);
  *
  * @param mintime The start of the oldest interval
  */
-void moveOverTimeMemory(time_t mintime);
+void moveOverTimeMemory(const time_t mintime);
 
 // capabilities.c
 bool check_capabilities(void);
diff --git a/shmem.c b/shmem.c
index 78157b6e..51731d5d 100644
--- a/shmem.c
+++ b/shmem.c
@@ -52,7 +52,7 @@ static ShmSettings *shmSettings = NULL;
 static int pagesize;
 static unsigned int local_shm_counter = 0;
 
-static size_t get_optimal_object_size(size_t objsize, size_t minsize);
+static size_t get_optimal_object_size(const size_t objsize, const size_t minsize);
 
 size_t addstr(const char *str)
 {
@@ -96,7 +96,7 @@ size_t addstr(const char *str)
 	return (shmSettings->next_str_pos - (len + 1));
 }
 
-const char *getstr(size_t pos)
+const char *getstr(const size_t pos)
 {
 	// Only access the string memory if this memory region has already been set
 	if(pos < shmSettings->next_str_pos)
@@ -149,17 +149,17 @@ static void remap_shm(void)
 	local_shm_counter = shmSettings->global_shm_counter;
 }
 
-void _lock_shm(const char* function, const int line, const char * file) {
+void _lock_shm(const char* func, const int line, const char * file) {
 	// Signal that FTL is waiting for a lock
 	shmLock->waitingForLock = true;
 
 	if(config.debug & DEBUG_LOCKS)
-		logg("Waiting for lock in %s() (%s:%i)", function, file, line);
+		logg("Waiting for lock in %s() (%s:%i)", func, file, line);
 
 	int result = pthread_mutex_lock(&shmLock->lock);
 
 	if(config.debug & DEBUG_LOCKS)
-		logg("Obtained lock for %s() (%s:%i)", function, file, line);
+		logg("Obtained lock for %s() (%s:%i)", func, file, line);
 
 	// Check if this process needs to remap the shared memory objects
 	if(shmSettings != NULL &&
@@ -185,11 +185,11 @@ void _lock_shm(const char* function, const int line, const char * file) {
 		logg("Failed to obtain SHM lock: %s", strerror(result));
 }
 
-void _unlock_shm(const char* function, const int line, const char * file) {
+void _unlock_shm(const char* func, const int line, const char * file) {
 	int result = pthread_mutex_unlock(&shmLock->lock);
 
 	if(config.debug & DEBUG_LOCKS)
-		logg("Removed lock in %s() (%s:%i)", function, file, line);
+		logg("Removed lock in %s() (%s:%i)", func, file, line);
 
 	if(result != 0)
 		logg("Failed to unlock SHM lock: %s", strerror(result));
@@ -280,7 +280,7 @@ void destroy_shmem(void)
 	delete_shm(&shm_settings);
 }
 
-SharedMemory create_shm(const char *name, size_t size)
+SharedMemory create_shm(const char *name, const size_t size)
 {
 	if(config.debug & DEBUG_SHMEM)
 		logg("Creating shared memory with name \"%s\" and size %zu", name, size);
@@ -313,10 +313,10 @@ SharedMemory create_shm(const char *name, size_t size)
 	}
 
 	// Resize shared memory file
-	int result = ftruncate(fd, size);
+	ret = ftruncate(fd, size);
 
 	// Check for `ftruncate` error
-	if(result == -1)
+	if(ret == -1)
 	{
 		logg("FATAL: create_shm(): ftruncate(%i, %zu): Failed to resize shared memory object \"%s\": %s",
 		     fd, size, sharedMemory.name, strerror(errno));
@@ -342,7 +342,7 @@ SharedMemory create_shm(const char *name, size_t size)
 	return sharedMemory;
 }
 
-void *enlarge_shmem_struct(char type)
+void *enlarge_shmem_struct(const char type)
 {
 	SharedMemory *sharedMemory = NULL;
 	size_t sizeofobj, allocation_step;
@@ -389,7 +389,7 @@ void *enlarge_shmem_struct(char type)
 	return sharedMemory->ptr;
 }
 
-bool realloc_shm(SharedMemory *sharedMemory, size_t size, bool resize)
+bool realloc_shm(SharedMemory *sharedMemory, const size_t size, const bool resize)
 {
 	// Check if we can skip this routine as nothing is to be done
 	// when an object is not to be resized and its size didn't
@@ -407,7 +407,7 @@ bool realloc_shm(SharedMemory *sharedMemory, size_t size, bool resize)
 	if(resize)
 	{
 		// Open shared memory object
-		int fd = shm_open(sharedMemory->name, O_RDWR, S_IRUSR | S_IWUSR);
+		const int fd = shm_open(sharedMemory->name, O_RDWR, S_IRUSR | S_IWUSR);
 		if(fd == -1)
 		{
 			logg("FATAL: realloc_shm(): Failed to open shared memory object \"%s\": %s",
@@ -416,7 +416,7 @@ bool realloc_shm(SharedMemory *sharedMemory, size_t size, bool resize)
 		}
 
 		// Truncate shared memory object to specified size
-		int result = ftruncate(fd, size);
+		const int result = ftruncate(fd, size);
 		if(result == -1) {
 			logg("FATAL: realloc_shm(): ftruncate(%i, %zu): Failed to resize \"%s\": %s",
 			     fd, size, sharedMemory->name, strerror(errno));
@@ -450,8 +450,7 @@ bool realloc_shm(SharedMemory *sharedMemory, size_t size, bool resize)
 void delete_shm(SharedMemory *sharedMemory)
 {
 	// Unmap shared memory
-	int ret;
-	ret = munmap(sharedMemory->ptr, sharedMemory->size);
+	int ret = munmap(sharedMemory->ptr, sharedMemory->size);
 	if(ret != 0)
 		logg("delete_shm(): munmap(%p, %zu) failed: %s", sharedMemory->ptr, sharedMemory->size, strerror(errno));
 
@@ -478,9 +477,9 @@ static size_t __attribute__((const)) gcd(size_t a, size_t b)
 // shared memory objects. This routine works by computing the LCM
 // of two numbers, the pagesize and the size of a single element
 // in the shared memory object
-static size_t get_optimal_object_size(size_t objsize, size_t minsize)
+static size_t get_optimal_object_size(const size_t objsize, const size_t minsize)
 {
-	size_t optsize = pagesize / gcd(pagesize, objsize);
+	const size_t optsize = pagesize / gcd(pagesize, objsize);
 	if(optsize < minsize)
 	{
 		if(config.debug & DEBUG_SHMEM)
@@ -496,7 +495,7 @@ static size_t get_optimal_object_size(size_t objsize, size_t minsize)
 		// First part: Integer division, may cause clipping, e.g., 5/3 = 1
 		// Second part: Catch a possibly happened clipping event by adding
 		//              one to the number: (5 % 3 != 0) is 1
-		size_t multiplier = (minsize/optsize) + ((minsize % optsize != 0) ? 1u : 0u);
+		const size_t multiplier = (minsize/optsize) + ((minsize % optsize != 0) ? 1u : 0u);
 		if(config.debug & DEBUG_SHMEM)
 		{
 			logg("DEBUG: Using %zu*%zu == %zu >= %zu",
diff --git a/shmem.h b/shmem.h
index 83290262..15646328 100644
--- a/shmem.h
+++ b/shmem.h
@@ -27,7 +27,7 @@ typedef struct {
 /// \param size the size to allocate
 /// \return a structure with a pointer to the mounted shared memory. The pointer
 /// will always be valid, because if it failed FTL will have exited.
-SharedMemory create_shm(const char *name, size_t size);
+SharedMemory create_shm(const char *name, const size_t size);
 
 /// Reallocate shared memory
 ///
@@ -35,7 +35,7 @@ SharedMemory create_shm(const char *name, size_t size);
 /// \param size the new size
 /// \param resize whether the object should be resized or only remapped
 /// \return if reallocation was successful
-bool realloc_shm(SharedMemory *sharedMemory, size_t size, bool resize);
+bool realloc_shm(SharedMemory *sharedMemory, const size_t size, const bool resize);
 
 /// Disconnect from shared memory. If there are no other connections to shared memory, it will be deleted.
 ///
diff --git a/socket.c b/socket.c
index 10adc411..8e779a74 100644
--- a/socket.c
+++ b/socket.c
@@ -201,7 +201,7 @@ static void removeport(void)
 	fclose(f);
 }
 
-void seom(int sock)
+void seom(const int sock)
 {
 	if(istelnet[sock])
 		ssend(sock, "---EOM---\n\n");
@@ -209,7 +209,7 @@ void seom(int sock)
 		pack_eom(sock);
 }
 
-void __attribute__ ((format (gnu_printf, 2, 3))) ssend(int sock, const char *format, ...)
+void __attribute__ ((format (gnu_printf, 2, 3))) ssend(const int sock, const char *format, ...)
 {
 	char *buffer;
 	va_list args;
@@ -224,12 +224,12 @@ void __attribute__ ((format (gnu_printf, 2, 3))) ssend(int sock, const char *for
 	}
 }
 
-void swrite(int sock, const void *value, size_t size) {
+void swrite(const int sock, const void *value, size_t size) {
 	if(write(sock, value, size) == -1)
 		logg("WARNING: Socket write returned error code %i", errno);
 }
 
-static inline int checkClientLimit(int socket) {
+static inline int checkClientLimit(const int socket) {
 	if(socket < MAXCONNS)
 	{
 		return socket;
@@ -243,7 +243,7 @@ static inline int checkClientLimit(int socket) {
 	}
 }
 
-static int listener(int sockfd, char type)
+static int listener(const int sockfd, const char type)
 {
 	struct sockaddr_un un_addr;
 	struct sockaddr_in in4_addr;
@@ -430,7 +430,7 @@ void *telnet_listening_thread_IPv4(void *args)
 	while(!killed)
 	{
 		// Look for new clients that want to connect
-		int csck = listener(telnetfd4, 4);
+		const int csck = listener(telnetfd4, 4);
 		if(csck == -1)
 		{
 			logg("IPv4 telnet error: %s (%i)", strerror(errno), errno);
@@ -471,7 +471,7 @@ void *telnet_listening_thread_IPv6(void *args)
 	while(!killed)
 	{
 		// Look for new clients that want to connect
-		int csck = listener(telnetfd6, 6);
+		const int csck = listener(telnetfd6, 6);
 		if(csck == -1)
 		{
 			logg("IPv6 telnet error: %s (%i)", strerror(errno), errno);
@@ -512,7 +512,7 @@ void *socket_listening_thread(void *args)
 	while(!killed)
 	{
 		// Look for new clients that want to connect
-		int csck = listener(socketfd, 0);
+		const int csck = listener(socketfd, 0);
 		if(csck < 0) continue;
 
 		// Allocate memory used to transport client socket ID to client listening thread
@@ -544,8 +544,8 @@ bool ipv6_available(void)
 		// Loop over interfaces
 		for (interface = allInterfaces; interface != NULL; interface = interface->ifa_next)
 		{
-			unsigned int flags = interface->ifa_flags;
-			struct sockaddr *addr = interface->ifa_addr;
+			const unsigned int flags = interface->ifa_flags;
+			const struct sockaddr *addr = interface->ifa_addr;
 
 			// Check only for up and running IPv4, IPv6 interfaces
 			if ((flags & (IFF_UP|IFF_RUNNING)) && addr != NULL)