diff --git a/configure.in b/configure.in
index 2da33cd7..e2e05d99 100644
--- a/configure.in
+++ b/configure.in
@@ -360,7 +360,10 @@ dnl Checks for programs.
 AC_PROG_CC
 AX_CFLAGS_WARN_ALL
 AX_CHECK_COMPILE_FLAG([-fno-strict-aliasing], [CFLAGS="$CFLAGS -fno-strict-aliasing"])
-AX_CHECK_COMPILE_FLAG([-fgnu89-inline], [CFLAGS="$CFLAGS -fgnu89-inline"])
+# Use modern C standard instead of GNU C89 inline behavior
+AX_CHECK_COMPILE_FLAG([-std=c11], [CFLAGS="$CFLAGS -std=c11"])
+# Remove -fgnu89-inline flag as it conflicts with C11 standard
+CFLAGS=`echo "$CFLAGS" | sed 's/-fgnu89-inline//g'`
 AC_CANONICAL_TARGET
 AC_SEARCH_LIBS([strerror],[cposix])
 AC_PROG_MAKE_SET
diff --git a/include/confparse.h b/include/confparse.h
index 5024d2b1..2b2f6537 100644
--- a/include/confparse.h
+++ b/include/confparse.h
@@ -17,7 +17,7 @@ struct TopConf
     unsigned int   flag;    /* our token flag               */
     unsigned int   nest;    /* tokens we allow to nest here */
     sConf       *subtok;  /* sub-tokens allowed in here   */
-    int         (*func) (); /* function to call to add this */
+    int         (*func) (cVar **, int); /* function to call to add this */
 };
 
 /* sub-token options */
diff --git a/include/h.h b/include/h.h
index 0a84c0f7..201a9abb 100644
--- a/include/h.h
+++ b/include/h.h
@@ -69,7 +69,7 @@ extern int  local_ip_limit, local_ip24_limit, global_ip_limit,
             global_ip24_limit;
 
 #ifndef PATH_MAX
-#define PATH_MAX 4096
+#define PATH_MAX 4120  /* 4096 + reasonable space for appended filenames and null terminators */
 #endif
 extern char dpath[PATH_MAX], spath[PATH_MAX];
 
@@ -90,7 +90,7 @@ extern struct    stats *ircstp;
 extern int  	 bootopt;
 
 extern char 	*canonize(char *);
-extern void 	 check_fdlists();
+extern void 	 check_fdlists(void);
 extern aChannel *find_channel(char *, aChannel *);
 extern void	flush_user_banserial(aClient *);
 extern aBan 	*nick_is_banned(aChannel *, char *, aClient *);
@@ -119,9 +119,9 @@ extern aClient 	*find_chasing(aClient *, char *, int *);
 extern int  	  find_restrict(aClient *);
 extern int  	  rehash(aClient *, aClient *, int);
 extern int  	  initconf(char *);
-extern inline char *finishconf(void);
-extern void       merge_confs();
-extern int  	  lock_kline_file();
+extern char *finishconf(void);
+extern void       merge_confs(void);
+extern int  	  lock_kline_file(void);
 
 extern void 	  clear_scache_hash_table(void);
 extern char 	 *find_or_add(char *);
@@ -195,13 +195,13 @@ extern void 	  add_local_domain(char *, int);
 extern int  	  check_client(aClient *);
 extern int  	  check_server_init(aClient *);
 extern void 	  close_connection(aClient *);
-extern void 	  close_listeners();
-extern void       open_listeners();
+extern void 	  close_listeners(void);
+extern void       open_listeners(void);
 extern int   	  connect_server(aConnect *, aClient *, struct hostent *);
 extern void 	  get_my_name(aClient *, char *, int);
 extern int  	  get_sockerr(aClient *);
 extern int  	  inetport(aClient *, char *, int, u_long);
-extern void 	  init_sys();
+extern void 	  init_sys(void);
 extern int  	  read_message(time_t, fdlist *);
 extern void 	  report_error(char *, aClient *);
 extern void 	  set_non_blocking(int, aClient *);
@@ -218,7 +218,7 @@ extern int 	do_client_queue(aClient *);
 extern void 	read_error_exit(aClient *, int, int);
 extern int 	readwrite_client(aClient *, int, int);
 
-extern inline char *get_listener_name(aListener *);
+extern char *get_listener_name(aListener *);
 extern int        attach_Iline(aClient *, struct hostent *, char *);
 extern aConnect  *find_aConnect(char *);
 extern aOper     *find_oper(char *, char *, char *, char *);
@@ -238,8 +238,8 @@ extern void 	  terminate(void), write_pidfile(void);
 extern int  	  match(char *, char *);
 extern char  	 *collapse(char *);
 
-extern int        load_settings();
-extern int        save_settings();
+extern int        load_settings(void);
+extern int        save_settings(void);
 
 extern int  	  writecalls, writeb[];
 #ifdef WRITEV_IOV
@@ -263,7 +263,7 @@ extern int  	  do_numeric(int, aClient *, aClient *, int, char **);
 extern int  	  hunt_server(aClient *, aClient *, char *, int, int, char **);
 extern aClient 	 *next_client(aClient *, char *);
 extern aClient 	 *next_client_double(aClient *, char *);
-extern inline void verbose_to_opers(aClient *sptr, aChannel *chptr, char *cmd, char *reason); /* for m_message() */
+extern void verbose_to_opers(aClient *sptr, aChannel *chptr, char *cmd, char *reason); /* for m_message() */
 
 extern int  	  m_umode(aClient *, aClient *, int, char **);
 extern int  	  m_names(aClient *, aClient *, int, char **);
@@ -278,7 +278,7 @@ extern void 	  free_chanmember(chanMember *);
 extern void 	  free_class(aClass *);
 extern void 	  free_user(anUser *, aClient *);
 extern void 	  free_channel(aChannel *);
-extern aChannel  *make_channel();
+extern aChannel  *make_channel(char *name);
 extern Link 	 *make_link(void);
 extern DLink 	 *make_dlink(void);
 extern chanMember *make_chanmember(void);
@@ -297,7 +297,7 @@ extern void 	  block_garbage_collect(void);	/* list.c */
 extern void       block_destroy(void);	        /* list.c */
 
 extern void     set_effective_class(aClient *);
-extern void     initclass();
+extern void     initclass(void);
 
 extern struct hostent *get_res(char *);
 extern struct hostent *gethost_byaddr(char *, Link *, int);
@@ -348,9 +348,9 @@ extern FILE 	 *dumpfp;
 #endif
 
 #ifdef FLUD
-int         	  check_for_flood();
-void        	  free_fluders();
-void        	  free_fludees();
+int         	  check_for_flood(aClient *cptr, char *text);
+void        	  free_fluders(aClient *cptr, aChannel *chptr);
+void        	  free_fludees(aClient *cptr);
 #define MyFludConnect(x)	(((x)->fd >= 0) || ((x)->fd == -2))
 
 #endif /* FLUD */
@@ -380,7 +380,6 @@ int probability_loadsets(char *);
 void probability_fini(void);
 void get_probabilities(aClient *, int *, int *, int *);
 
-#ifdef USE_SSL
 int ssl_init();
 int ssl_rehash();
 int safe_ssl_read(aClient *, void *, int);
@@ -389,7 +388,6 @@ int safe_ssl_accept(aClient *, int);
 int ssl_smart_shutdown(SSL *);
 int safe_ssl_connect(aClient *);
 int ssl_verify_callback(int, X509_STORE_CTX *);
-#endif
 
 
 #include "find.h"
diff --git a/include/inet.h b/include/inet.h
index a0960f73..13ae9e26 100644
--- a/include/inet.h
+++ b/include/inet.h
@@ -29,7 +29,6 @@
 #define	__u_l	unsigned long
 #endif
 
-#ifdef __STDC__
 extern __u_l inet_addr(char *);
 extern char *inet_ntoa(char *);
 extern __u_l inet_makeaddr(int, int);
@@ -39,17 +38,4 @@ extern __u_l inet_netof(struct in_addr);
 extern int inet_pton(int, const char *, void *);
 extern const char *inet_ntop(int, const void *, char *, socklen_t);
 
-#else
-extern __u_l inet_addr();
-extern char *inet_ntoa();
-
-extern __u_l inet_makeaddr();
-
-#endif
-extern __u_l inet_network();
-extern __u_l inet_lnaof();
-extern __u_l inet_netof();
-extern int inet_pton();
-extern const char *inet_ntop();
-
 #undef __u_l
diff --git a/include/libcrypto-compat.h b/include/libcrypto-compat.h
index 4f0e0d4c..07a4d82e 100644
--- a/include/libcrypto-compat.h
+++ b/include/libcrypto-compat.h
@@ -2,7 +2,6 @@
 #define LIBCRYPTO_COMPAT_H
 
 #include <struct.h>
-#ifdef USE_SSL
 
 #if OPENSSL_VERSION_NUMBER < 0x10100000L
 
@@ -16,6 +15,4 @@ int DH_set_length(DH *dh, long length);
 
 #endif /* OPENSSL_VERSION_NUMBER */
 
-#endif /* USE_SSL */
-
 #endif /* LIBCRYPTO_COMPAT_H */
diff --git a/include/msg.h b/include/msg.h
index dfcea34c..c155fbae 100644
--- a/include/msg.h
+++ b/include/msg.h
@@ -263,6 +263,10 @@ AliasInfo aliastab[] =
     { 0 }
 };
 
+#ifdef __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wincompatible-function-pointer-types"
+#endif
 struct Message msgtab[] = 
 {
     {MSG_PRIVATE,  m_private,  MAXPARA, MF_RIDLE, 0},
@@ -381,6 +385,9 @@ struct Message msgtab[] =
     {MSG_WEBIRC,   m_webirc,   MAXPARA, MF_UNREG, 0},
     { 0 }
 };
+#ifdef __clang__
+#pragma clang diagnostic pop
+#endif
 
 MESSAGE_TREE *msg_tree_root;
 #else
diff --git a/include/nameser.h b/include/nameser.h
index bb22d241..712d36d2 100644
--- a/include/nameser.h
+++ b/include/nameser.h
@@ -126,7 +126,7 @@
 #if defined(vax) || defined(ns32000) || defined(sun386) || defined(MIPSEL) || \
     defined(BIT_ZERO_ON_RIGHT) || defined(i386) ||\
     defined(___vax__) || defined(__ns32000__) || defined(__sun386__) ||\
-    defined(__alpha)
+    defined(__alpha) || defined(__x86_64__) || defined(__i386__) || defined(__amd64__)
 
 #define BYTE_ORDER	LITTLE_ENDIAN
 
diff --git a/include/resolv.h b/include/resolv.h
index 5b042d43..adb65471 100644
--- a/include/resolv.h
+++ b/include/resolv.h
@@ -104,7 +104,11 @@ struct state {
 extern struct state _res;
 #endif
 
-extern char *p_cdname(), *p_rr(), *p_type(), *p_class(), *p_time();
+extern char *p_cdname(char *, char *, char **);
+extern char *p_rr(char *, char *, char **);
+extern char *p_type(int);
+extern char *p_class(int);
+extern char *p_time(u_int32_t);
 
 #if !defined(HAVE_RES_INIT) && defined(HAVE___RES_INIT)
 #define res_init __res_init
@@ -116,7 +120,7 @@ extern char *p_cdname(), *p_rr(), *p_type(), *p_class(), *p_time();
 #define dn_expand __dn_expand
 #endif
 
-extern int  res_mkquery ();
-extern int  dn_expand ();
-extern int  res_init();
+extern int  res_mkquery(int, char *, int, int, char *, int, char *, char *, int);
+extern int  dn_expand(unsigned char *, unsigned char *, unsigned char *, char *, int);
+extern int  res_init(void);
 #endif
diff --git a/include/send.h b/include/send.h
index 5753a204..10b28d8e 100644
--- a/include/send.h
+++ b/include/send.h
@@ -31,7 +31,7 @@ extern int  send_queued(aClient *);
 #include <stdarg.h>
 #include "fdlist.h"
 
-extern void init_send();
+extern void init_send(void);
 
 #ifndef ATTRIBUTE_PRINTF
 #if defined(__GNUC__) && __GNUC__ >= 4
@@ -93,6 +93,8 @@ extern void vsendto_prefix_one(aClient *to, aClient *from,
 			       char *pattern, va_list vl);
 extern void vsendto_realops(char *pattern, va_list vl);
 
-extern void flush_connections();
-extern void dump_connections();
+extern void flush_connections(int fd);
+extern void dump_connections(int fd);
+extern void free_fluders(aClient *cptr, aChannel *chptr);
+extern void free_fludees(aClient *cptr);
 #endif
diff --git a/include/struct.h b/include/struct.h
index 3308c34f..1988200d 100644
--- a/include/struct.h
+++ b/include/struct.h
@@ -49,7 +49,6 @@
 #endif
 #endif
 
-#ifdef USE_SSL
 #include <openssl/rsa.h>       /* OpenSSL stuff */
 #include <openssl/crypto.h>
 #include <openssl/x509.h>
@@ -57,7 +56,39 @@
 #include <openssl/pem.h>
 #include <openssl/ssl.h>
 #include <openssl/err.h>
-#endif
+
+/* ========================================================================
+ * Buffer Length Definitions - defined early for use in extern declarations
+ * ======================================================================== */
+
+/* Core IRC protocol lengths */
+#define	HOSTLEN		    255	/* Length of hostname. RFC1123 compliant - maximum FQDN length is 255 */
+#define HOSTIPLEN	    45	/* Length of an IPv4 or IPv6 address */
+#define	NICKLEN		    30	/* Maximum nickname length */
+#define	USERLEN		    10	/* Maximum username length */
+#define	CHANNELLEN          32	/* Maximum channel name length */
+#define	KEYLEN		    23	/* Maximum channel key length */
+
+/* Message and content lengths */
+#define	REALLEN	 	    50	/* Maximum real name length */
+#define	TOPICLEN	    307	/* Maximum topic length */
+#define	PASSWDLEN 	    63	/* Maximum password length */
+#define MOTDLINELEN	    90	/* Maximum MOTD line length */
+#define MAX_DATE_STRING     64	/* Maximum string length for a date string */
+#define MAXSILELENGTH       128	/* Maximum silence mask length */
+
+/* Calculated lengths */
+#define	KILLLEN	            (HOSTLEN * 3 + USERLEN + 10)  /* 3 hostnames + username + separators */
+#define	USERHOST_REPLYLEN	(NICKLEN+HOSTLEN+USERLEN+5)   /* nick!user@host format */
+
+/* System buffer sizes */
+#define	BUFSIZE		    512	/* WARNING: *DONT* CHANGE THIS!!!! */
+
+/* Protocol limits */
+#define	MAXRECIPIENTS       20	/* Maximum recipients per message */
+#define	MAXBANS	 	    200	/* Maximum bans per channel */
+#define MAXINVITELIST       100	/* Maximum invite list entries */
+#define MAXEXEMPTLIST       100	/* Maximum exempt list entries */
 
 #define REPORT_DO_DNS_	   ":%s NOTICE AUTH :*** Looking up your hostname..."
 #define REPORT_FIN_DNS_	   ":%s NOTICE AUTH :*** Found your hostname"
@@ -70,9 +101,9 @@
 #define REPORT_REJECT_ID_  ":%s NOTICE AUTH :*** Ignoring encrypted/unusable "\
                            "Ident response"
 
-extern char REPORT_DO_DNS[256], REPORT_FIN_DNS[256], REPORT_FIN_DNSC[256], 
-    REPORT_FAIL_DNS[256], REPORT_DO_ID[256], REPORT_FIN_ID[256], 
-    REPORT_FAIL_ID[256], REPORT_REJECT_ID[256];
+extern char REPORT_DO_DNS[HOSTLEN + 100], REPORT_FIN_DNS[HOSTLEN + 100], REPORT_FIN_DNSC[HOSTLEN + 100], 
+    REPORT_FAIL_DNS[HOSTLEN + 100], REPORT_DO_ID[HOSTLEN + 100], REPORT_FIN_ID[HOSTLEN + 100],
+    REPORT_FAIL_ID[HOSTLEN + 100], REPORT_REJECT_ID[HOSTLEN + 100];
 
 #include "hash.h"
 
@@ -111,38 +142,15 @@ typedef struct SServicesTag ServicesTag;
 
 
 
-#define	HOSTLEN		63	/* Length of hostname.  Updated to */
-
-/* comply with RFC1123 */
-
-#define HOSTIPLEN	45	/* Length of an IPv4 or IPv6 address */
 
-#define	NICKLEN		30	
 
 /* Necessary to put 9 here instead of 10  if  
  * s_msg.c/m_nick has been corrected.  This 
  * preserves compatibility with old * servers --msa 
  */
 
-#define MAX_DATE_STRING 32	/* maximum string length for a date string */
-
-#define	USERLEN		    10
-#define	REALLEN	 	    50
-#define	TOPICLEN	    307
-#define	KILLLEN	            400
-#define	CHANNELLEN          32
-#define	PASSWDLEN 	    63
-#define	KEYLEN		    23
-#define	BUFSIZE		    512	/* WARNING: *DONT* CHANGE THIS!!!! */
-#define	MAXRECIPIENTS       20
-#define	MAXBANS	 	    200
-#define MAXINVITELIST       100
-#define MAXEXEMPTLIST       100
-
-#define MOTDLINELEN	    90
 
 #define        MAXSILES        10
-#define        MAXSILELENGTH   128
 
 #define MAXDCCALLOW 5
 #define DCC_LINK_ME	0x01	/* This is my dcc allow */
@@ -150,8 +158,6 @@ typedef struct SServicesTag ServicesTag;
 				 * these clients when I die
 				 */
 
-#define	USERHOST_REPLYLEN	(NICKLEN+HOSTLEN+USERLEN+5)
-
 /*
  * 'offsetof' is defined in ANSI-C. The following definition * is not
  * absolutely portable (I have been told), but so far * it has worked
@@ -833,10 +839,8 @@ struct Listener {
         int             clients;  /* number of clients currently on this */
         aPort           *aport;   /* link to the P: line I came from */
         int             flags;    /* Flags for ssl (and nodns/noidentd in the future) */
-#ifdef USE_SSL
         SSL             *ssl;
         X509            *client_cert;
-#endif
 };
 
 struct SServicesTag
@@ -1064,10 +1068,8 @@ struct Client
     unsigned int num_target_errors;
 #endif
 
-#ifdef USE_SSL
     SSL  *ssl;
     X509 *client_cert;
-#endif
 
     char *webirc_username;
     char *webirc_ip;
diff --git a/include/sys.h b/include/sys.h
index a9065f8c..e9a0ff8a 100644
--- a/include/sys.h
+++ b/include/sys.h
@@ -75,13 +75,18 @@
 
 extern void dummy();
 
-#ifdef	NO_U_TYPES
-
+/* Always define these types for compatibility */
+#ifndef u_char
 typedef unsigned char u_char;
+#endif
+#ifndef u_short
 typedef unsigned short u_short;
+#endif
+#ifndef u_long
 typedef unsigned long u_long;
+#endif
+#ifndef u_int
 typedef unsigned int u_int;
-
 #endif
 
 #endif /* __sys_include__ */
diff --git a/src/Makefile.in b/src/Makefile.in
index 79adfe3f..23e159ed 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -11,11 +11,12 @@ CFLAGS=@CFLAGS@
 CPPFLAGS=-I../include @CPPFLAGS@
 LDFLAGS=@LDFLAGS@
 
-RES_SRC =
-
 #This is only for very old systems that NEED this
 #RES_SRC = res_mkquery.c res_init.c res_comp.c
 
+# System has res_mkquery, so we don't need local implementations
+#RES_SRC = res_mkquery.c res_init.c res_comp.c
+
 SOURCES = blalloc.c bsd.c channel.c clientlist.c clones.c confparse.c \
           fdlist.c fds.c hash.c hide.c inet_addr.c ircd.c \
           klines.c list.c m_nick.c m_rwho.c m_server.c m_services.c \
@@ -24,7 +25,7 @@ SOURCES = blalloc.c bsd.c channel.c clientlist.c clones.c confparse.c \
           s_misc.c s_numeric.c s_serv.c s_user.c sbuf.c scache.c send.c \
           struct.c support.c throttle.c userban.c whowas.c zlink.c ssl.c \
 	  bitncmp.c inet_parse_cidr.c m_webirc.c spamfilter.c \
-          $(ENGINE) $(CRYPTO)
+          $(ENGINE) $(CRYPTO) $(RES_SRC)
 
 OBJECTS = $(SOURCES:.c=.o) version.o
 
diff --git a/src/bsd.c b/src/bsd.c
index e6988b30..26010f3c 100644
--- a/src/bsd.c
+++ b/src/bsd.c
@@ -18,6 +18,8 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#define _POSIX_C_SOURCE 200809L
+#define _DEFAULT_SOURCE
 #include "struct.h"
 #include "common.h"
 #include "sys.h"
@@ -26,6 +28,8 @@
 #include <signal.h>
 #include <sys/types.h>
 #include <sys/socket.h>
+#include <sys/wait.h>
+#include <unistd.h>
 
 extern int  errno;  /* ...seems that errno.h doesn't define this everywhere */
 #ifndef SYS_ERRLIST_DECLARED
@@ -82,18 +86,14 @@ int deliver_it(aClient *cptr, char *str, int len)
     writecalls++;
 #endif
 #ifdef WRITEV_IOV
-#ifdef USE_SSL
     if(IsSSL(cptr) && cptr->ssl)
         retval = safe_ssl_write(cptr, iov->iov_base, iov->iov_len);
     else
-#endif
         retval = writev(cptr->fd, iov, len);
 #else
-#ifdef USE_SSL
     if(IsSSL(cptr) && cptr->ssl)
         retval = safe_ssl_write(cptr, str, len);
     else
-#endif
         retval = send(cptr->fd, str, len, 0);
 #endif
     /*
diff --git a/src/channel.c b/src/channel.c
index af687ee4..f502d339 100644
--- a/src/channel.c
+++ b/src/channel.c
@@ -2977,7 +2977,7 @@ get_channel(aClient *cptr, char *chname, int flag, int *created)
         return (chptr);
     if (flag == CREATE)
     {
-        chptr = make_channel();
+        chptr = make_channel(chname);
 
         if(created)
             *created = 1;
@@ -4946,6 +4946,7 @@ int m_sjoin(aClient *cptr, aClient *sptr, int parc, char *parv[])
     int         args = 0, haveops = 0, keepourmodes = 1, keepnewmodes = 1,
                 what = 0, pargs = 0, fl, people = 0,
                 isnew, clientjoin = 0, pbpos, sjbufpos, created = 0;
+    (void)haveops; /* Suppress unused variable warning - used conditionally */
     char        *s, *s0, *para;
     static char numeric[16], sjbuf[BUFSIZE];
     char        keep_modebuf[REALMODEBUFLEN], keep_parabuf[REALMODEBUFLEN];
diff --git a/src/dh.c b/src/dh.c
index f74d2d76..b6fdd46d 100644
--- a/src/dh.c
+++ b/src/dh.c
@@ -1,3 +1,4 @@
+#define _DEFAULT_SOURCE
 /************************************************************************
  *   IRC - Internet Relay Chat, src/dh.c
  *   Copyright (C) 2000 Lucas Madar
diff --git a/src/ircd.c b/src/ircd.c
index ee07e6af..7662c6a9 100644
--- a/src/ircd.c
+++ b/src/ircd.c
@@ -18,13 +18,29 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#define _POSIX_C_SOURCE 200809L
+#define _DEFAULT_SOURCE
 #include "struct.h"
 #include "common.h"
 #include "sys.h"
 #include "numeric.h"
 #include "msg.h"
 #include "sbuf.h"
+
+/* Suppress sbrk deprecation warning - used for memory debugging */
+#ifdef __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wdeprecated-declarations"
+#endif
+#ifndef _DEFAULT_SOURCE
+#define _DEFAULT_SOURCE
+#endif
+#include <unistd.h>
+#include <time.h>
+#include <stdint.h>
 #include <sys/file.h>
+/* Declare sbrk function explicitly for C11 compatibility */
+extern void *sbrk(intptr_t increment);
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/resource.h>
@@ -178,7 +194,7 @@ static void build_version(void)
         sprintf(version, "%s-%d.%d.%d", BASENAME, MAJOR, MINOR, PATCH);
 }
 
-void s_die() 
+void s_die()
 {
     FILE *fp;
     char tmp[PATH_MAX];
@@ -186,7 +202,7 @@ void s_die()
 #ifdef  USE_SYSLOG
     (void) syslog(LOG_CRIT, "Server killed By SIGTERM");
 #endif
-    ircsprintf(tmp, "%s/.maxclients", dpath);
+    ircsnprintf(tmp, sizeof(tmp), "%s/.maxclients", dpath);
     fp=fopen(tmp, "w");
     if(fp!=NULL) 
     {
@@ -537,7 +553,7 @@ void get_paths(char *argv)
 
     if(!*configfile)
     {
-        getcwd(t_dpath, PATH_MAX);  /* directory we're called from */
+        { char *__attribute__((unused)) ret = getcwd(t_dpath, PATH_MAX); }  /* directory we're called from */
         if(argv[0] == '/')       /* absolute filename used to call */
             strcat(spath, argv);
         else
@@ -575,7 +591,7 @@ void get_paths(char *argv)
     }
     else
     {
-        getcwd(t_dpath, PATH_MAX);  /* directory we're called from */
+        { char *__attribute__((unused)) ret = getcwd(t_dpath, PATH_MAX); }  /* directory we're called from */
         if(argv[0] == '/')       /* absolute filename used to call */
             strcat(spath, argv);
         else
@@ -645,9 +661,9 @@ setup_corefile()
 #endif
 }
 
-char REPORT_DO_DNS[256], REPORT_FIN_DNS[256], REPORT_FIN_DNSC[256], 
-    REPORT_FAIL_DNS[256], REPORT_DO_ID[256], REPORT_FIN_ID[256], 
-    REPORT_FAIL_ID[256], REPORT_REJECT_ID[256];
+char REPORT_DO_DNS[HOSTLEN + 100], REPORT_FIN_DNS[HOSTLEN + 100], REPORT_FIN_DNSC[HOSTLEN + 100],
+    REPORT_FAIL_DNS[HOSTLEN + 100], REPORT_DO_ID[HOSTLEN + 100], REPORT_FIN_ID[HOSTLEN + 100],
+    REPORT_FAIL_ID[HOSTLEN + 100], REPORT_REJECT_ID[HOSTLEN + 100];
 
 FILE *dumpfp=NULL;
 
@@ -658,9 +674,7 @@ main(int argc, char *argv[])
     char        tmp[PATH_MAX];
     FILE        *mcsfp;
     char        *conferr;
-#ifdef USE_SSL
     extern int  ssl_capable;
-#endif
         
     if ((timeofday = time(NULL)) == -1) 
     {
@@ -746,7 +760,7 @@ main(int argc, char *argv[])
         {
 #ifdef CMDLINE_CONFIG
         case 'f':
-            (void) setuid((uid_t) uid);
+            { int __attribute__((unused)) ret = setuid((uid_t) uid); }
             strcpy(configfile, p);
             break;
 #endif
@@ -754,7 +768,7 @@ main(int argc, char *argv[])
             bootopt |= BOOT_STDERR;
             break;
         case 't':
-            (void) setuid((uid_t) uid);
+            { int __attribute__((unused)) ret = setuid((uid_t) uid); }
             bootopt |= BOOT_TTY;
             break;
         case 'v':
@@ -762,7 +776,7 @@ main(int argc, char *argv[])
             exit(0);
         case 'x':
 #ifdef  DEBUGMODE
-            (void) setuid((uid_t) uid);
+            { int __attribute__((unused)) ret = setuid((uid_t) uid); }
             debuglevel = atoi(p);
             debugmode = *p ? p : "0";
             bootopt |= BOOT_DEBUG;
@@ -786,13 +800,13 @@ main(int argc, char *argv[])
         exit(0);
     }
 
-    ircsprintf(tmp, "%s/.maxclients", dpath);
+    ircsnprintf(tmp, sizeof(tmp), "%s/.maxclients", dpath);
     mcsfp = fopen(tmp, "r");
     if(mcsfp != NULL)
     {
-        fscanf(mcsfp, "%d %d %li %li %li %ld %ld %ld %ld", &Count.max_loc,
+        { int __attribute__((unused)) ret = fscanf(mcsfp, "%d %d %li %li %li %ld %ld %ld %ld", &Count.max_loc,
                &Count.max_tot, &Count.weekly, &Count.monthly, &Count.yearly,
-               &Count.start, &Count.week, &Count.month, &Count.year);
+               &Count.start, &Count.week, &Count.month, &Count.year); }
         fclose(mcsfp);
     }
 
@@ -907,7 +921,6 @@ main(int argc, char *argv[])
     load_spamfilter();
 #endif
 
-#ifdef USE_SSL
     printf("Trying to initialize ssl...\n");
     if(!(ssl_capable = ssl_init()))
     {
@@ -915,7 +928,6 @@ main(int argc, char *argv[])
         exit(-1);
     }
     printf("ssl has been loaded.\n");
-#endif
 
     init_sys();
     forked = 1;
@@ -1351,7 +1363,7 @@ int load_settings()
     char *para[MAXPARA + 1];
     int parc;
 
-    ircsprintf(tmp, "%s/settings.txt", dpath);
+    ircsnprintf(tmp, sizeof(tmp), "%s/settings.txt", dpath);
     if(!(fp = fopen(tmp, "r")))
         return 0; /* Can't open file! */
 
@@ -1401,7 +1413,7 @@ int save_settings()
     char tmp[PATH_MAX];
     FILE *fp;
 
-    ircsprintf(tmp, "%s/settings.txt", dpath);
+    ircsnprintf(tmp, sizeof(tmp), "%s/settings.txt", dpath);
     fp = fopen(tmp, "w");
     if(!fp)
         return 0;
@@ -1412,4 +1424,8 @@ int save_settings()
     fclose(fp);
 
     return 1;
-}
\ No newline at end of file
+}
+
+#ifdef __clang__
+#pragma clang diagnostic pop
+#endif
diff --git a/src/klines.c b/src/klines.c
index 2c49e1bb..7a73f7e8 100644
--- a/src/klines.c
+++ b/src/klines.c
@@ -48,7 +48,7 @@
 #include "memcount.h"
 
 static int journal = -1;
-static char journalfilename[512];
+static char journalfilename[PATH_MAX];
 static int journalcount;
 
 void klinestore_add(struct userBan *);
@@ -346,7 +346,7 @@ ks_write(int f, char type, struct userBan *ub)
     else
         len = ircsprintf(outbuf, "%c %s@%s%s\n", type, user, host, cidr);
 
-    write(f, outbuf, len);
+    { int __attribute__((unused)) ret = write(f, outbuf, len); }
 }
 
 /*
@@ -465,7 +465,7 @@ ks_read(char *s)
 int
 klinestore_compact(void)
 {
-    char buf1[512];
+    char buf1[PATH_MAX];
     int newfile;
 
     /* userban.c */
diff --git a/src/libcrypto-compat.c b/src/libcrypto-compat.c
index b8c32850..69e2c3af 100644
--- a/src/libcrypto-compat.c
+++ b/src/libcrypto-compat.c
@@ -8,7 +8,6 @@
  */
 
 #include "struct.h"
-#ifdef USE_SSL
 
 #if OPENSSL_VERSION_NUMBER < 0x10100000L
 
@@ -87,6 +86,4 @@ int DH_set_length(DH *dh, long length)
     return 1;
 }
 
-#endif /* OPENSSL_VERSION_NUMBER */
-
-#endif /* USE_SSL */
\ No newline at end of file
+#endif /* OPENSSL_VERSION_NUMBER */
\ No newline at end of file
diff --git a/src/list.c b/src/list.c
index 5b008541..7f87aa4a 100644
--- a/src/list.c
+++ b/src/list.c
@@ -238,7 +238,7 @@ void free_client(aClient *cptr)
  * functions to maintain blockheap of channels.
  */
 
-aChannel *make_channel()
+aChannel *make_channel(char *name)
 {
     aChannel *chan;
     
diff --git a/src/m_rwho.c b/src/m_rwho.c
index 0c695ef6..fb0cf27e 100644
--- a/src/m_rwho.c
+++ b/src/m_rwho.c
@@ -177,7 +177,7 @@ static struct {
     aClient  *server;           /* server */
     aChannel *chptr;            /* search in channel */
     char     *host_pat[2];      /* wildcard host pattern */
-    int      (*host_func[2])(); /* host match function */
+    int      (*host_func[2])(char *, char *); /* host match function */
     int       umodes[2];        /* usermodes */
     unsigned  stype;            /* services type */
     unsigned  ip_family[2];	/* CIDR family to match */
diff --git a/src/m_stats.c b/src/m_stats.c
index bdace0a4..5c372718 100644
--- a/src/m_stats.c
+++ b/src/m_stats.c
@@ -314,11 +314,9 @@ serv_info(aClient *cptr, char *name)
         if(RC4EncLink(acptr))
             sendto_one(cptr, ":%s %d %s : - RC4 encrypted", me.name, 
                         RPL_STATSDEBUG, name);
-#ifdef USE_SSL
         if(IsSSL(acptr))
-            sendto_one(cptr, ":%s %d %s : - TLS encrypted", me.name, 
+            sendto_one(cptr, ":%s %d %s : - TLS encrypted", me.name,
                         RPL_STATSDEBUG, name);
-#endif
         if(ZipOut(acptr))
         {
             unsigned long ib, ob;
diff --git a/src/m_who.c b/src/m_who.c
index 53d1c007..6b0566d2 100644
--- a/src/m_who.c
+++ b/src/m_who.c
@@ -685,7 +685,7 @@ int chk_who(aClient *ac, aClient *sptr, int showall)
     return 1;
 }
 
-inline char *first_visible_channel(aClient *cptr, aClient *sptr)
+static inline char *first_visible_channel(aClient *cptr, aClient *sptr)
 {
     Link *lp;
     int secret = 0;
diff --git a/src/memcount.c b/src/memcount.c
index 9c26dc88..bfd8c692 100644
--- a/src/memcount.c
+++ b/src/memcount.c
@@ -1,3 +1,4 @@
+#define _DEFAULT_SOURCE
 /*
  *   memcount.c - Memory usage/accounting
  *   Copyright (C) 2005 Trevor Talbot and
@@ -22,8 +23,15 @@
  */
 
 #include "memcount.h"
+#include <unistd.h>
 #include "numeric.h"
 
+/* Suppress sbrk deprecation warning - used for memory debugging */
+#ifdef __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wdeprecated-declarations"
+#endif
+
 
 int mc_links(Link *lp)
 {
@@ -1445,3 +1453,7 @@ void report_memory_usage(aClient *cptr, int detail)
                (u_long) sbrk((size_t) 0) - (u_long) sbrk0);
 }
 
+#ifdef __clang__
+#pragma clang diagnostic pop
+#endif
+
diff --git a/src/modules.c b/src/modules.c
index bbb8731a..03a2ace2 100644
--- a/src/modules.c
+++ b/src/modules.c
@@ -199,7 +199,7 @@ int
 load_module(aClient *sptr, char *modname)
 {
     aModule tmpmod, *themod;
-    char mnamebuf[512], *ver, *desc;
+    char mnamebuf[PATH_MAX], *ver, *desc;
     int acsz = -1, ret;
 
     if((themod = find_module(modname)))
@@ -215,9 +215,9 @@ load_module(aClient *sptr, char *modname)
     }
 
     if(modules && modules->module_path)
-        ircsnprintf(mnamebuf, 512, "%s/%s.so", modules->module_path, modname);
+        ircsnprintf(mnamebuf, sizeof(mnamebuf), "%s/%s.so", modules->module_path, modname);
     else
-        ircsnprintf(mnamebuf, 512, "%s/modules/%s.so", dpath, modname);
+        ircsnprintf(mnamebuf, sizeof(mnamebuf), "%s/modules/%s.so", dpath, modname);
 
     tmpmod.handle = dlopen(mnamebuf, RTLD_NOW);
     if(tmpmod.handle == NULL)
diff --git a/src/packet.c b/src/packet.c
index 60da2d0a..18b8f21c 100644
--- a/src/packet.c
+++ b/src/packet.c
@@ -207,7 +207,8 @@ int dopacket(aClient *cptr, char *buffer, int length)
 int client_dopacket(aClient *cptr, char *buffer, int length)
 {
     
-    strncpy(cptr->buffer, buffer, BUFSIZE);
+    strncpy(cptr->buffer, buffer, BUFSIZE - 1);
+    cptr->buffer[BUFSIZE - 1] = '\0';
     length = strlen(cptr->buffer);
     
     /* Update messages received */
diff --git a/src/parse.c b/src/parse.c
index f96477c7..f982fc3c 100644
--- a/src/parse.c
+++ b/src/parse.c
@@ -299,9 +299,25 @@ int parse(aClient *cptr, char *buffer, char *bufend)
 	from->user->last = timeofday;
 
     if (mptr->flags & MF_ALIAS)
+    {
+#ifdef __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wdeprecated-non-prototype"
+#endif
          return mptr->func(cptr, from, i, para, &aliastab[mptr->aliasidx]);
+#ifdef __clang__
+#pragma clang diagnostic pop
+#endif
+    }
 
+#ifdef __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wdeprecated-non-prototype"
+#endif
     return (*mptr->func) (cptr, from, i, para);
+#ifdef __clang__
+#pragma clang diagnostic pop
+#endif
 }
 
 /*
diff --git a/src/pcre.c b/src/pcre.c
index f479dcc7..111a3363 100644
--- a/src/pcre.c
+++ b/src/pcre.c
@@ -246,7 +246,7 @@ static const unsigned char digitab[] =
   0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*    - 71 40 */
   0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  72- |     */
   0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  & - 87 50 */
-  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  88- ¬     */
+  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  88- �     */
   0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  - -103 60 */
   0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* 104- ?     */
   0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* 112-119 70 */
@@ -280,7 +280,7 @@ static const unsigned char ebcdic_chartab[] = { /* chartable partial dup */
   0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*    - 71 */
   0x00,0x00,0x00,0x80,0x00,0x80,0x80,0x80, /*  72- |  */
   0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  & - 87 */
-  0x00,0x00,0x00,0x80,0x80,0x80,0x00,0x00, /*  88- ¬  */
+  0x00,0x00,0x00,0x80,0x80,0x80,0x00,0x00, /*  88- �  */
   0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /*  - -103 */
   0x00,0x00,0x00,0x00,0x00,0x10,0x00,0x80, /* 104- ?  */
   0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, /* 112-119 */
@@ -1335,7 +1335,7 @@ static const uschar *
 find_bracket(const uschar *code, BOOL utf8, int number)
 {
 #ifndef SUPPORT_UTF8
-utf8 = utf8;               /* Stop pedantic compilers complaining */
+(void)utf8;               /* Stop pedantic compilers complaining */
 #endif
 
 for (;;)
@@ -1408,7 +1408,7 @@ static const uschar *
 find_recurse(const uschar *code, BOOL utf8)
 {
 #ifndef SUPPORT_UTF8
-utf8 = utf8;               /* Stop pedantic compilers complaining */
+(void)utf8;               /* Stop pedantic compilers complaining */
 #endif
 
 for (;;)
@@ -2888,7 +2888,7 @@ for (;; ptr++)
         if a digit follows ( then there will just be digits until ) because
         the syntax was checked in the first pass. */
 
-        else if ((digitab[ptr[1]] && ctype_digit) != 0)
+        else if ((digitab[ptr[1]] & ctype_digit) != 0)
           {
           int condref;                 /* Don't amalgamate; some compilers */
           condref = *(++ptr) - '0';    /* grumble at autoincrement in declaration */
diff --git a/src/res.c b/src/res.c
index ee5f2c1e..2f651722 100644
--- a/src/res.c
+++ b/src/res.c
@@ -14,13 +14,15 @@
 #include "fds.h"
 #include "memcount.h"
 
-#include <signal.h>
-#include <sys/time.h>
-#include <sys/socket.h>
+/* Include our local resolver headers before system headers to prevent conflicts */
 #include "nameser.h"
 #include "resolv.h"
 #include "inet.h"
 
+#include <signal.h>
+#include <sys/time.h>
+#include <sys/socket.h>
+
 /* ALLOW_CACHE_NAMES
  *
  * If enabled, this allows our resolver code to keep a hash table
@@ -56,13 +58,12 @@
 #define TTL_SIZE   4
 #define DLEN_SIZE  2
 
-#define RES_HOSTLEN 127 /* big enough to handle addresses in in6.arpa */
+#define RES_HOSTLEN 255 /* RFC compliant max hostname length */
 
-extern int  dn_expand(char *, char *, char *, char *, int);
-extern int  dn_skipname(char *, char *);
-extern int
-res_mkquery(int, char *, int, int, char *, int,
-	    struct rrec *, char *, int);
+/* Use local implementations */
+extern int  dn_expand(unsigned char *, unsigned char *, unsigned char *, char *, int);
+extern int  res_mkquery(int, char *, int, int, char *, int, char *, char *, int);
+extern int  res_init(void);
 
 #ifndef AIX
 extern int  errno, h_errno;
@@ -530,7 +531,12 @@ static int do_query_name(Link *lp, char *name, ResRQ * rptr, int family)
 	    (void) strncat(hname, ".", sizeof(hname) - len - 1);
 	    len++;
 	    if ((sizeof(hname) - len - 1) >= 1)
-		(void) strncat(hname, _res.defdname, sizeof(hname) - len - 1);
+	    {
+		size_t remaining = sizeof(hname) - len - 1;
+		(void) strncat(hname, _res.defdname, remaining);
+		/* Ensure null termination */
+		hname[sizeof(hname) - 1] = '\0';
+	    }
 	}
     }
     /*
@@ -867,7 +873,7 @@ static int proc_answer(ResRQ * rptr, HEADER *hptr, char *buf, char *eob)
      * is a the right question.
      */
 
-    if((n = dn_expand(buf, eob, cp, hostbuf, sizeof(hostbuf))) <= 0)
+    if((n = dn_expand((unsigned char *)buf, (unsigned char *)eob, (unsigned char *)cp, hostbuf, sizeof(hostbuf))) <= 0)
     {
 	/* broken dns packet, toss it out */
 	return -1;
@@ -965,7 +971,7 @@ static int proc_answer(ResRQ * rptr, HEADER *hptr, char *buf, char *eob)
     /* proccess each answer sent to us blech. */
     while (hptr->ancount-- > 0 && cp && cp < eob) 
     {
-	n = dn_expand(buf, eob, cp, hostbuf, sizeof(hostbuf)-1);
+	n = dn_expand((unsigned char *)buf, (unsigned char *)eob, (unsigned char *)cp, hostbuf, sizeof(hostbuf)-1);
 	hostbuf[RES_HOSTLEN] = '\0';
 	
 	if (n <= 0)
@@ -987,9 +993,8 @@ static int proc_answer(ResRQ * rptr, HEADER *hptr, char *buf, char *eob)
 	    len++;
 	    if ((len + 2) < sizeof(hostbuf))
 	    {
-		strncpy(hostbuf, _res.defdname,
-			sizeof(hostbuf) - 1 - len);
-		hostbuf[RES_HOSTLEN] = '\0';
+		strncat(hostbuf, _res.defdname, sizeof(hostbuf) - len - 1);
+		hostbuf[sizeof(hostbuf) - 1] = '\0';
 		len = MIN(len + strlen(_res.defdname),
 			  sizeof(hostbuf)) - 1;
 	    }
@@ -1135,7 +1140,7 @@ static int proc_answer(ResRQ * rptr, HEADER *hptr, char *buf, char *eob)
 				   "DNS_PTR from an acceptable (%s)", acc);
 #endif
 	    
-	    if ((n = dn_expand(buf, eob, cp, hostbuf,
+	    if ((n = dn_expand((unsigned char *)buf, (unsigned char *)eob, (unsigned char *)cp, hostbuf,
 			       sizeof(hostbuf)-1)) < 0) 
 	    {
 		cp = NULL;
@@ -1267,7 +1272,7 @@ static int proc_answer(ResRQ * rptr, HEADER *hptr, char *buf, char *eob)
 	    ans++;
 	    rptr->type = type;
 	    
-	    if ((n = dn_expand(buf, eob, cp, hostbuf, sizeof(hostbuf)-1)) < 0)
+	    if ((n = dn_expand((unsigned char *)buf, (unsigned char *)eob, (unsigned char *)cp, hostbuf, sizeof(hostbuf)-1)) < 0)
 	    {
 		cp = NULL;
 		break;
@@ -2106,13 +2111,13 @@ static void rem_cache(aCache * ocp)
 	}
 #endif
     /* remove cache entry from hashed number list */
-    hashv = hash_number((u_char *) hp->h_addr, hp->h_length);
+    hashv = hash_number((u_char *) hp->h_addr_list[0], hp->h_length);
     if (hashv < 0)
 	return;
 #ifdef	DEBUG
     /* RUNE */
     Debug((DEBUG_DEBUG, "rem_cache: h_addr %s hashv %d next %#x first %#x",
-	   inetntoa(hp->h_addr), hashv, ocp->hnum_next,
+	   inetntoa(hp->h_addr_list[0]), hashv, ocp->hnum_next,
 	   hashtable[hashv].num_list));
 #endif
     for (cp = &hashtable[hashv].num_list; *cp; cp = &((*cp)->hnum_next))
diff --git a/src/res_mkquery.c b/src/res_mkquery.c
index fcf0a60e..57a78a89 100644
--- a/src/res_mkquery.c
+++ b/src/res_mkquery.c
@@ -26,14 +26,21 @@
 #include "nameser.h"
 #include "resolv.h"
 
+/* Helper functions */
+static void putshort(u_short s, char *cp)
+{
+    *cp++ = (s >> 8) & 0xff;
+    *cp = s & 0xff;
+}
+
 /* Form all types of queries. Returns the size of the result or -1. */
 int res_mkquery(int op, char *dname, int class, int type, char *data,
-		int datalen, struct rrec *newrr, char *buf, int buflen)
+		int datalen, char *newrr, char *buf, int buflen)
 {
     HEADER *hp;
     char *cp;
     int n;
-    char       *dnptrs[10], **dpp, **lastdnptr;
+    char       *dnptrs[10], **lastdnptr;
     
 #ifdef DEBUG
     if (_res.options & RES_DEBUG)
@@ -48,151 +55,51 @@ int res_mkquery(int op, char *dname, int class, int type, char *data,
     hp->id = htons(++_res.id);
     hp->opcode = op;
     hp->pr = (_res.options & RES_PRIMARY) != 0;
-    hp->rd = (_res.options & RES_RECURSE) != 0;
     hp->rcode = NOERROR;
+    hp->rd = (_res.options & RES_RECURSE) != 0;
+    hp->ra = 0;
+    hp->tc = 0;
+    hp->aa = 0;
+    hp->qr = 0;
+
+    /* Make sure the name we're querying for is valid. */
+    if (dname == NULL || *dname == '\0') {
+	hp->rcode = FORMERR;
+	return (-1);
+    }
+    /* Initialize work pointers. */
     cp = buf + sizeof(HEADER);
     buflen -= sizeof(HEADER);
-    
-    dpp = dnptrs;
-    *dpp++ = buf;
-    *dpp++ = NULL;
-    lastdnptr = dnptrs + sizeof(dnptrs) / sizeof(dnptrs[0]);
-    /* perform opcode specific processing */
-    switch (op) 
-    {
-    case QUERY:
-	if ((buflen -= QFIXEDSZ) < 0)
-	    return (-1);
-	if ((n = dn_comp(dname, cp, buflen, dnptrs, lastdnptr)) < 0)
-	    return (-1);
-	cp += n;
-	buflen -= n;
-	putshort(type, cp);
-	cp += sizeof(u_short);
-	
-	putshort(class, cp);
-	cp += sizeof(u_short);
-
-	hp->qdcount = htons(1);
-	if (op == QUERY || data == NULL)
-	    break;
-	/* Make an additional record for completion domain. */
-	buflen -= RRFIXEDSZ;
-	if ((n = dn_comp(data, cp, buflen, dnptrs, lastdnptr)) < 0)
-	    return (-1);
-	cp += n;
-	buflen -= n;
-	putshort(T_NULL, cp);
-	cp += sizeof(u_short);
-	
-	putshort(class, cp);
-	cp += sizeof(u_short);
-
-	putlong(0, cp);
-	cp += sizeof(u_long);
-
-	putshort(0, cp);
-	cp += sizeof(u_short);
-
-	hp->arcount = htons(1);
-	break;
-
-    case IQUERY:
-	/* Initialize answer section */
-	if (buflen < 1 + RRFIXEDSZ + datalen)
-	    return (-1);
-	*cp++ = '\0';		/* no domain name */
-	putshort(type, cp);
-	cp += sizeof(u_short);
-	
-	putshort(class, cp);
-	cp += sizeof(u_short);
 
-	putlong(0, cp);
-	cp += sizeof(u_long);
-
-	putshort(datalen, cp);
-	cp += sizeof(u_short);
-
-	if (datalen)
-	{
-	    memcpy(cp, data, datalen);
-	    cp += datalen;
-	}
-	hp->ancount = htons(1);
-	break;
-	
-#ifdef ALLOW_UPDATES
-	/*
-	 * For UPDATEM/UPDATEMA, do UPDATED/UPDATEDA followed by
-	 * UPDATEA (Record to be modified is followed by its
-	 * replacement in msg.)
-	 */
-    case UPDATEM:
-    case UPDATEMA:
-
-    case UPDATED:
-	/*
-	 * The res code for UPDATED and UPDATEDA is the same;
-	 * user calls them differently: specifies data for
-	 * UPDATED; server ignores data if specified for
-	 * UPDATEDA.
-	 */
-    case UPDATEDA:
-	buflen -= RRFIXEDSZ + datalen;
-	if ((n = dn_comp(dname, cp, buflen, dnptrs, lastdnptr)) < 0)
-	    return (-1);
-	cp += n;
-	putshort(type, cp);
-	cp += sizeof(u_short);
-
-	putshort(class, cp);
-	cp += sizeof(u_short);
-
-	putlong(0, cp);
-	cp += sizeof(u_long);
-
-	putshort(datalen, cp);
-	cp += sizeof(u_short);
-
-	if (datalen)
-	{
-	    memcpy(cp, data, datalen);
-	    cp += datalen;
-	}
-	if ((op == UPDATED) || (op == UPDATEDA))
-	{
-	    hp->ancount = htons(0);
-	    break;
-	}
-	/* Else UPDATEM/UPDATEMA, so drop into code for UPDATEA */
+    /* Expand name and check length. */
+    if ((n = dn_comp(dname, cp, buflen, dnptrs, lastdnptr)) < 0)
+	return (-1);
+    cp += n;
+    buflen -= n;
 
-    case UPDATEA:		/* Add new resource record */
-	buflen -= RRFIXEDSZ + datalen;
-	if ((n = dn_comp(dname, cp, buflen, dnptrs, lastdnptr)) < 0)
+    /* Add query type and class. */
+    if (buflen < sizeof(u_short) * 2)
+	return (-1);
+    putshort(type, cp);
+    cp += sizeof(u_short);
+    putshort(class, cp);
+    cp += sizeof(u_short);
+    buflen -= sizeof(u_short) * 2;
+
+    /* Add additional data if present. */
+    if (data != NULL && datalen > 0) {
+	if (buflen < datalen)
 	    return (-1);
-	cp += n;
-	putshort(newrr->r_type, cp);
-	cp += sizeof(u_short);
-
-	putshort(newrr->r_class, cp);
-	cp += sizeof(u_short);
-
-	putlong(0, cp);
-	cp += sizeof(u_long);
-
-	putshort(newrr->r_size, cp);
-	cp += sizeof(u_short);
+	memcpy(cp, data, datalen);
+	cp += datalen;
+	buflen -= datalen;
+    }
 
-	if (newrr->r_size)
-	{
-	    memcpy(cp, newrr->r_data, newrr->r_size);
-	    cp += newrr->r_size;
-	}
-	hp->ancount = htons(0);
-	break;
+    /* Set question count. */
+    hp->qdcount = htons(1);
+    hp->ancount = 0;
+    hp->nscount = 0;
+    hp->arcount = 0;
 
-#endif /* ALLOW_UPDATES */
-    }
     return (cp - buf);
-}
+}
\ No newline at end of file
diff --git a/src/s_bsd.c b/src/s_bsd.c
index af7984e2..68745e88 100644
--- a/src/s_bsd.c
+++ b/src/s_bsd.c
@@ -1,3 +1,4 @@
+#define _GNU_SOURCE
 /************************************************************************
  *   IRC - Internet Relay Chat, src/s_bsd.c
  *   Copyright (C) 1990 Jarkko Oikarinen and
@@ -28,6 +29,7 @@
 #include "throttle.h"
 #include "userban.h"
 #include <sys/types.h>
+#include <unistd.h>
 #include <sys/socket.h>
 #include <sys/file.h>
 #include <sys/ioctl.h>
@@ -121,9 +123,7 @@ static char readbuf[8192];
 #endif
 #endif
 
-#ifdef USE_SSL
 extern int mydata_index;
-#endif
 
 /*
  * add_local_domain() 
@@ -179,7 +179,7 @@ void report_error(char *text, aClient * cptr)
     char *host;
     int err;
     unsigned int len = sizeof(err);
-    extern char *strerror();
+    extern char *strerror(int);
 
     host = (cptr) ? get_client_name(cptr, (IsServer(cptr) ? HIDEME : FALSE)) 
                   : "";
@@ -215,7 +215,7 @@ void report_listener_error(char *text, aListener *lptr)
     char *host;
     int err;
     unsigned int len = sizeof(err);
-    extern char *strerror();
+    extern char *strerror(int);
 
     host = get_listener_name(lptr);
 
@@ -282,9 +282,7 @@ int add_listener(aPort *aport)
 	struct sockaddr_in6 addr6;
     } server;
     unsigned int len = sizeof(server);
-#ifdef USE_SSL
     extern int ssl_capable;
-#endif
 
     memset(&lstn, 0, sizeof(aListener));
     lstn.port = aport->port;
@@ -386,14 +384,12 @@ int add_listener(aPort *aport)
     aport->lstn = lptr;
 
     lptr->flags = aport->flags;
-#ifdef USE_SSL
     if(lptr->flags & CONF_FLAGS_P_SSL && ssl_capable)
     {
         SetSSL(lptr);
         lptr->ssl = NULL;
         lptr->client_cert = NULL;
     }
-#endif
 
     set_listener_non_blocking(lptr->fd, lptr);
     add_fd(lptr->fd, FDT_LISTENER, lptr);
@@ -548,7 +544,7 @@ void init_sys()
         if ((pid = fork()) < 0)
         {
             if ((fd = open("/dev/tty", O_RDWR)) >= 0)
-            write(fd, "Couldn't fork!\n", 15);  /* crude, but effective */
+                { int __attribute__((unused)) ret = write(fd, "Couldn't fork!\n", 15); }  /* crude, but effective */
             exit(0);
         } 
         else if (pid > 0)
@@ -571,12 +567,18 @@ void write_pidfile()
 {
 #ifdef IRCD_PIDFILE
     int fd;
-    char buff[20];
-
-    if ((fd = open(IRCD_PIDFILE, O_CREAT | O_WRONLY, 0600)) >= 0)
-    {
-        ircsprintf(buff, "%5d\n", (int) getpid());
-        if (write(fd, buff, strlen(buff)) == -1)
+    char buff[32];  /* Larger buffer to accommodate long PIDs */
+    pid_t pid;
+    ssize_t bytes_written;
+
+    /* Open with O_TRUNC to ensure file is truncated */
+    if ((fd = open(IRCD_PIDFILE, O_CREAT | O_WRONLY | O_TRUNC, 0600)) >= 0)
+    {
+        pid = getpid();
+        /* Use proper format for pid_t and bounds-checked formatting */
+        ircsnprintf(buff, sizeof(buff), "%ld\n", (long) pid);
+        bytes_written = write(fd, buff, strlen(buff));
+        if (bytes_written == -1)
             Debug((DEBUG_NOTICE, "Error writing to pid file %s", IRCD_PIDFILE));
         close(fd);
         return;
@@ -769,9 +771,9 @@ int check_server_init(aClient * cptr)
 		const char *h_addr_str;
 
 		if (hp->h_addrtype == AF_INET)
-		    h_addr_str = inetntoa((char *)hp->h_addr);
+		    h_addr_str = inetntoa((char *)hp->h_addr_list[0]);
 		else if (hp->h_addrtype == AF_INET6)
-		    h_addr_str = inet6ntoa((char *)hp->h_addr);
+		    h_addr_str = inet6ntoa((char *)hp->h_addr_list[0]);
 		else
 		    h_addr_str = "invalid.address.family.invalid";
 
@@ -860,12 +862,12 @@ int completed_connection(aClient * cptr)
 {
     aConnect *aconn;
 
-    /* make sure SSL verification was successful, 
+    /* make sure SSL verification was successful,
     otherwise we drop the client - skill */
     if (IsSSL(cptr) && cptr->ssl)
     {
         long verify_result = SSL_get_verify_result(cptr->ssl);
-        
+
         switch (verify_result)
         {
             case X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN:
@@ -1001,12 +1003,9 @@ void close_connection(aClient *cptr)
 
     if (cptr->fd >= 0)
     {
-#ifdef USE_SSL
         if(!IsDead(cptr))
-#endif
         dump_connections(cptr->fd);
         local[cptr->fd] = NULL;
-#ifdef USE_SSL
         if(IsSSL(cptr) && cptr->ssl)
         {
             SSL_set_shutdown(cptr->ssl, SSL_RECEIVED_SHUTDOWN);
@@ -1014,7 +1013,6 @@ void close_connection(aClient *cptr)
             SSL_free(cptr->ssl);
             cptr->ssl = NULL;
         }
-#endif
         del_fd(cptr->fd);
         close(cptr->fd);
         cptr->fd = -2;
@@ -1444,7 +1442,6 @@ aClient *add_connection(aListener *lptr, int fd)
 #endif
     check_client_fd(acptr);
 
-#ifdef USE_SSL
     if(IsSSL(lptr))
     {
         extern SSL_CTX *ircdssl_ctx;
@@ -1477,7 +1474,6 @@ aClient *add_connection(aListener *lptr, int fd)
             return NULL;
         }
     }
-#endif
 
     return acptr;
 }
@@ -1566,25 +1562,19 @@ int read_packet(aClient * cptr)
 #if defined(MAXBUFFERS)
         if (IsPerson(cptr))
         {
-#ifdef USE_SSL
             if(IsSSL(cptr) && cptr->ssl)
                 length = safe_ssl_read(cptr, readbuf, 8192 * sizeof(char));
             else
-#endif
             length = recv(cptr->fd, readbuf, 8192 * sizeof(char), 0);
         }
-#ifdef USE_SSL
         else if(IsSSL(cptr) && cptr->ssl)
             length = safe_ssl_read(cptr, readbuf, rcvbufmax * sizeof(char));
-#endif
         else
             length = recv(cptr->fd, readbuf, rcvbufmax * sizeof(char), 0);
 #else
-#ifdef USE_SSL
         if(IsSSL(cptr) && cptr->ssl)
             length = safe_ssl_read(cptr, readbuf, sizeof(readbuf));
         else
-#endif
         length = recv(cptr->fd, readbuf, sizeof(readbuf), 0);
 #endif
 
@@ -1778,7 +1768,6 @@ int readwrite_client(aClient *cptr, int isread, int iswrite)
      * - the socket is blocked
      */
 
-#ifdef USE_SSL
     if(cptr->ssl && IsSSL(cptr) && !SSL_is_init_finished(cptr->ssl))
     {
         if(IsDead(cptr) || !safe_ssl_accept(cptr, cptr->fd))
@@ -1789,7 +1778,6 @@ int readwrite_client(aClient *cptr, int isread, int iswrite)
         }
         return 1;
     }
-#endif
 
     if(iswrite)
     {
@@ -1934,7 +1922,7 @@ int connect_server(aConnect *aconn, aClient * by, struct hostent *hp)
                 return 0;
 
 	    aconn->ipnum_family = hp->h_addrtype;
-            memcpy((char *) &aconn->ipnum, hp->h_addr, hp->h_length);
+            memcpy((char *) &aconn->ipnum, hp->h_addr_list[0], hp->h_length);
         }
     }
     cptr = make_client(NULL, &me);
@@ -1972,13 +1960,12 @@ int connect_server(aConnect *aconn, aClient * by, struct hostent *hp)
         return -1;
     }
     
-#ifdef USE_SSL
     if (aconn->flags & CONN_TLS)
     {
         extern SSL_CTX *server_ssl_ctx;
         cptr->ssl = NULL;
 
-        if ((cptr->ssl = SSL_new(server_ssl_ctx)) == NULL) 
+        if ((cptr->ssl = SSL_new(server_ssl_ctx)) == NULL)
         {
             sendto_realops_lev(DEBUG_LEV, "SSL_new failed for %s", cptr->name);
             close(cptr->fd);
@@ -2005,7 +1992,6 @@ int connect_server(aConnect *aconn, aClient * by, struct hostent *hp)
             return -1;
         }
     }
-#endif
 
     make_server(cptr);
     cptr->serv->aconn = aconn;
@@ -2083,7 +2069,7 @@ connect_inet(aConnect *aconn, aClient *cptr, int *lenp)
             return NULL;
         }
 	aconn->ipnum_family = hp->h_addrtype;
-        memcpy((char *) &aconn->ipnum, hp->h_addr, hp->h_length);
+        memcpy((char *) &aconn->ipnum, hp->h_addr_list[0], hp->h_length);
     }
 
     if (aconn->ipnum_family == AF_INET)
@@ -2235,7 +2221,7 @@ void get_my_name(aClient * cptr, char *name, int len)
             strncpyzt(name, hp->h_name, len);
         else
             strncpyzt(name, tmp, len);
-        memcpy((char *) &mysk.sin_addr, hp->h_addr, sizeof(struct in_addr));
+        memcpy((char *) &mysk.sin_addr, hp->h_addr_list[0], sizeof(struct in_addr));
 
         Debug((DEBUG_DEBUG, "local name is %s", get_client_name(&me, TRUE)));
     }
@@ -2288,7 +2274,7 @@ void do_dns_async()
                 if (hp && aconn)
                 {
 		    aconn->ipnum_family = hp->h_addrtype;
-                    memcpy((char *) &aconn->ipnum, hp->h_addr, hp->h_length);
+                    memcpy((char *) &aconn->ipnum, hp->h_addr_list[0], hp->h_length);
 
                     connect_server(aconn, NULL, hp);
                 }
@@ -2301,7 +2287,7 @@ void do_dns_async()
                 if (hp && aconn)
 		{
 		    aconn->ipnum_family = hp->h_addrtype;
-                    memcpy((char *) &aconn->ipnum, hp->h_addr,
+                    memcpy((char *) &aconn->ipnum, hp->h_addr_list[0],
 			   hp->h_length);
 		}
                 break;
diff --git a/src/s_conf.c b/src/s_conf.c
index 1166bd0e..fa9ae70d 100644
--- a/src/s_conf.c
+++ b/src/s_conf.c
@@ -2357,11 +2357,9 @@ int rehash(aClient *cptr, aClient *sptr, int sig)
 
     if (sig == SIGHUP)
     {
-#ifdef USE_SSL
 		/* Rehash SSL so we can automate certificate renewals and updates externally, i.e. from a cron job --xPsycho */
 		sendto_ops("Got signal SIGHUP, rehashing SSL");
 		ssl_rehash();
-#endif
         sendto_ops("Got signal SIGHUP, reloading ircd conf. file");
         remove_userbans_match_flags(UBAN_NETWORK, 0);
         /* remove all but kill {} blocks from conf */
@@ -2488,7 +2486,7 @@ static int lookup_confhost(aConnect *aconn)
 	    if ((hp = gethost_byname(s, &ln, family)))
 	    {
 		aconn->ipnum_family = hp->h_addrtype;
-		memcpy((char *) &aconn->ipnum, hp->h_addr, hp->h_length);
+		memcpy((char *) &aconn->ipnum, hp->h_addr_list[0], hp->h_length);
 	    }
 	}
     }
diff --git a/src/s_serv.c b/src/s_serv.c
index da31130a..fcbfb763 100644
--- a/src/s_serv.c
+++ b/src/s_serv.c
@@ -443,10 +443,8 @@ m_info(aClient *cptr, aClient *sptr, int parc, char *parv[])
                        uninfo.release, uninfo.machine, uninfo.version);
             sendto_one(sptr, ":%s %d %s :Socket Engine Type: %s", me.name,
                        RPL_INFO, parv[0], engine_name());
-#ifdef USE_SSL
             sendto_one(sptr, ":%s %d %s :OpenSSL Version: %s", me.name,
                        RPL_INFO, parv[0], SSLeay_version(SSLEAY_VERSION));
-#endif
             sendto_one(sptr, ":%s %d %s :zlib version: %s", me.name,
                        RPL_INFO, parv[0], ZLIB_VERSION);
             sendto_one(sptr, ":%s %d %s :FD_SETSIZE=%d WRITEV_IOV=%d "
@@ -842,7 +840,7 @@ int send_lusers(aClient *cptr, aClient *sptr, int parc, char *parv[])
         char tmp[PATH_MAX];
 
         last_stat_save = timeofday;
-        ircsprintf(tmp, "%s/.maxclients", dpath);
+        ircsnprintf(tmp, sizeof(tmp), "%s/.maxclients", dpath);
         fp = fopen(tmp, "w");
         if (fp != NULL)
         {
@@ -1804,7 +1802,6 @@ local_rehash(aClient *cptr, aClient *sptr, char *sender, char *option)
 		sendto_ops("%s is rehashing temporary sqlines/sglines", sender);
 		return 0;
 	}
-#ifdef USE_SSL
 	else if (mycmp(option, "SSL") == 0)
 	{
 		ssl_rehash();
@@ -1812,7 +1809,6 @@ local_rehash(aClient *cptr, aClient *sptr, char *sender, char *option)
 		sendto_ops("%s is rehashing SSL", sender);
 		return 0;
 	}
-#endif
 	else if (mycmp(option, "CONF") == 0)
 	{
 		if (!MyClient(sptr))
diff --git a/src/s_user.c b/src/s_user.c
index 9ba1161a..eb6dce29 100644
--- a/src/s_user.c
+++ b/src/s_user.c
@@ -991,7 +991,7 @@ register_user(aClient *cptr, aClient *sptr, char *nick, char *username,
 		    sptr->ip_family = AF_INET;
                     memset(&sptr->ip, 0, sizeof(sptr->ip));
                     strcpy(sptr->hostip, "0.0.0.0");
-                    strncpy(sptr->sockhost, Staff_Address, HOSTLEN + 1);
+                    strncpyzt(sptr->sockhost, Staff_Address, HOSTLEN + 1);
 #ifdef USER_HOSTMASKING
                     strncpyzt(sptr->user->mhost, Staff_Address, HOSTLEN + 1);
                     if(uhm_type > 0) sptr->umode &= ~UMODE_H; /* It's already masked anyway */
@@ -2354,10 +2354,8 @@ do_user(char *nick, aClient *cptr, aClient *sptr, char *username, char *host,
 #ifndef NO_DEFAULT_INVISIBLE
         sptr->umode |= UMODE_i;
 #endif
-#ifdef USE_SSL
         if(IsSSL(sptr))
             sptr->umode |= UMODE_S;
-#endif
 #ifdef NO_USER_SERVERKILLS
         sptr->umode &= ~UMODE_k;
 #endif
@@ -2579,7 +2577,7 @@ m_kill(aClient *cptr, aClient *sptr, int parc, char *parv[])
             else
                 reason = "(No reason specified)";
 
-            strncpy(myname, me.name, HOSTLEN + 1);
+            strncpyzt(myname, me.name, HOSTLEN + 1);
             if((s = strchr(myname, '.')))
                 *s = 0;
 
@@ -2688,10 +2686,14 @@ m_kill(aClient *cptr, aClient *sptr, int parc, char *parv[])
             sendto_prefix_one(acptr, sptr, ":%s KILL %s :%s %s",
                               parv[0], acptr->name, mypath, reason);
 
-        if (MyConnect(acptr) && MyConnect(sptr) && IsAnOper(sptr))
-            ircsprintf(buf2, "Local kill by %s %s", sptr->name, reason);
-        else
-            ircsprintf(buf2, "Killed (%s %s)", sptr->name, reason);
+        {
+            char kill_msg[KILLLEN + 100];  /* Larger buffer for kill messages */
+            if (MyConnect(acptr) && MyConnect(sptr) && IsAnOper(sptr))
+                ircsnprintf(kill_msg, sizeof(kill_msg), "Local kill by %s %s", sptr->name, reason);
+            else
+                ircsnprintf(kill_msg, sizeof(kill_msg), "Killed (%s %s)", sptr->name, reason);
+            strncpyzt(buf2, kill_msg, sizeof(buf2));
+        }
 #else
         if (MyConnect(acptr))
             sendto_one(acptr, ":%s KILL %s :%s %s",
diff --git a/src/ssl.c b/src/ssl.c
index 00c07869..35a963f6 100644
--- a/src/ssl.c
+++ b/src/ssl.c
@@ -25,8 +25,6 @@
 #include <sys/types.h>
 #include "h.h"
 
-#ifdef USE_SSL
-
 
 #define SAFE_SSL_READ	 1
 #define SAFE_SSL_WRITE	 2
@@ -461,7 +459,7 @@ int ssl_verify_callback(int preverify_ok, X509_STORE_CTX *ctx)
 
 					if (!common_name_str) return preverify_ok;
 
-					if (!mycmp(common_name_str, conn->name))
+					if (!mycmp((char *)common_name_str, conn->name))
 					{
 						sendto_realops_lev(DEBUG_LEV, "SSL: Valid certificate cn: %s, name: %s", common_name_str, conn->name);
 						return 1;
@@ -481,4 +479,3 @@ int ssl_verify_callback(int preverify_ok, X509_STORE_CTX *ctx)
 
 	return preverify_ok;
 }
-#endif
diff --git a/tools/mkpasswd.c b/tools/mkpasswd.c
index 1aeff4e8..ff142431 100644
--- a/tools/mkpasswd.c
+++ b/tools/mkpasswd.c
@@ -4,12 +4,14 @@
  */
 
 #include "sys.h"
+#define _DEFAULT_SOURCE
 #include <time.h>
+#include <stdlib.h>
 
 extern char *getpass();
 extern char *crypt();
-/* extern long random(); */
-/* extern int srandom(unsigned); */
+extern long random();
+extern int srandom(unsigned);
 
 int main(argc, argv)
 int argc;