Add missing defines for SOFT_FAIL/HARD_FAIL in util.h

This is for these previous 2 commits:
  * 428c1b6 Allow checking ssl files are readable (check_ssl_files)
  * a03b123 Also reload SSL context on bip reload, allowing for SSL cert updates

configure.ac

@@ -94,6 +94,74 @@ if test "$ap_cv_cc_pie" = "yes"; then
 	enable_pie=yes
 fi
 
+
+AC_CACHE_CHECK([whether $CC accepts hardening flags], [ap_cv_cc_hardening], [
+	save_CFLAGS=$CFLAGS
+	save_LDFLAGS=$LDFLAGS
+	CFLAGS="$CFLAGS -O2 -D_FORTIFY_SOURCE=2 -fstack-protector-strong -fstack-clash-protection -Wl,-z,relro -Wl,-z,now -Wl,-z,noexecstack -Wl,-z,separate-code"
+	AC_RUN_IFELSE([AC_LANG_SOURCE([[static int foo[30000]; int main () { return 0; }]])],
+		[ap_cv_cc_hardening=yes],
+		[ap_cv_cc_hardening=no],
+		[ap_cv_cc_hardening=yes]
+	)
+	CFLAGS=$save_CFLAGS
+])
+if test "$ap_cv_cc_hardening" = "yes"; then
+	CFLAGS="$CFLAGS -O2 -D_FORTIFY_SOURCE=2 -fstack-protector-strong -fstack-clash-protection -Wl,-z,relro -Wl,-z,now -Wl,-z,noexecstack -Wl,-z,separate-code"
+	enable_cc_hardening=yes
+fi
+
+AC_CACHE_CHECK([whether $CC accepts some warning flags], [ap_cv_cc_warnings], [
+	save_CFLAGS=$CFLAGS
+	save_LDFLAGS=$LDFLAGS
+	CFLAGS="$CFLAGS -Wformat-overflow=2 -Wformat-truncation=2 -Wtrampolines -Warray-bounds=2 -Wimplicit-fallthrough=3 -Wtraditional-conversion -Wshift-overflow=2 -Wstringop-overflow=4 -Wlogical-op -Wduplicated-cond -Wduplicated-branches -Wformat-signedness -Wstack-usage=1000000 -Wcast-align=strict"
+	AC_RUN_IFELSE([AC_LANG_SOURCE([[static int foo[30000]; int main () { return 0; }]])],
+		[ap_cv_cc_warnings=yes],
+		[ap_cv_cc_warnings=no],
+		[ap_cv_cc_warnings=yes]
+	)
+	CFLAGS=$save_CFLAGS
+])
+if test "$ap_cv_cc_warnings" = "yes"; then
+	CFLAGS="$CFLAGS -Wformat-overflow=2 -Wformat-truncation=2 -Wtrampolines -Warray-bounds=2 -Wimplicit-fallthrough=3 -Wtraditional-conversion -Wshift-overflow=2 -Wstringop-overflow=4 -Wlogical-op -Wduplicated-cond -Wduplicated-branches -Wformat-signedness -Wstack-usage=1000000 -Wcast-align=strict"
+	enable_cc_warnings=yes
+fi
+
+AC_CACHE_CHECK([whether $CC accepts some supplementary warning flags], [ap_cv_cc_warnings2], [
+	save_CFLAGS=$CFLAGS
+	save_LDFLAGS=$LDFLAGS
+	CFLAGS="$CFLAGS -Wformat=2 -Wformat-security -Wnull-dereference -Wstack-protector -Walloca -Wvla -Wcast-qual -Wconversion -Wshadow -Wstrict-overflow=4 -Wstrict-prototypes -Wswitch-default -Wswitch-enum"
+	AC_RUN_IFELSE([AC_LANG_SOURCE([[static int foo[30000]; int main () { return 0; }]])],
+		[ap_cv_cc_warnings2=yes],
+		[ap_cv_cc_warnings2=no],
+		[ap_cv_cc_warnings2=yes]
+	)
+	CFLAGS=$save_CFLAGS
+])
+if test "$ap_cv_cc_warnings2" = "yes"; then
+	CFLAGS="$CFLAGS -Wformat=2 -Wformat-security -Wnull-dereference -Wstack-protector -Walloca -Wvla -Wcast-qual -Wconversion -Wshadow -Wstrict-overflow=4 -Wstrict-prototypes -Wswitch-default -Wswitch-enum"
+	enable_cc_warnings2=yes
+fi
+
+
+
+AC_CACHE_CHECK([whether $CC accepts -Warith-conversion flag], [ap_cv_cc_warith], [
+	save_CFLAGS=$CFLAGS
+	save_LDFLAGS=$LDFLAGS
+	CFLAGS="$CFLAGS -Warith-conversion"
+	AC_RUN_IFELSE([AC_LANG_SOURCE([[static int foo[30000]; int main () { return 0; }]])],
+		[ap_cv_cc_warith=yes],
+		[ap_cv_cc_warith=no],
+		[ap_cv_cc_warith=yes]
+	)
+	CFLAGS=$save_CFLAGS
+])
+if test "$ap_cv_cc_warith" = "yes"; then
+	CFLAGS="$CFLAGS -Warith-conversion"
+	enable_warith_conversion=yes
+fi
+
+
 PKG_CHECK_MODULES([CHECK], [check >= 0.9.6], [enable_tests=yes], [enable_tests=no])
 AM_CONDITIONAL([COND_WANT_TESTS], [test "$enable_tests" = yes])
 

src/Makefile.am

@@ -36,9 +36,4 @@ bipmkpw_LDADD = libbip.a libbiplex.a $(OPENSSL_LIBS)
 AM_YFLAGS= -d
 BUILT_SOURCES = conf.c conf.h lex.c
 
-AM_CFLAGS=-Wall -Wextra -Werror \
-	-O2 \
-	-D_FORTIFY_SOURCE=2 \
-	-fstack-protector-strong -fstack-clash-protection \
-	-Wl,-z,relro -Wl,-z,now -Wl,-z,noexecstack -Wl,-z,separate-code \
-	-Wpedantic -Wformat=2 -Wformat-overflow=2 -Wformat-truncation=2 -Wformat-security -Wnull-dereference -Wstack-protector -Wtrampolines -Walloca -Wvla -Warray-bounds=2 -Wimplicit-fallthrough=3 -Wtraditional-conversion -Wshift-overflow=2 -Wcast-qual -Wstringop-overflow=4 -Wconversion -Warith-conversion -Wlogical-op -Wduplicated-cond -Wduplicated-branches -Wformat-signedness -Wshadow -Wstrict-overflow=4 -Wundef -Wstrict-prototypes -Wswitch-default -Wswitch-enum -Wstack-usage=1000000 -Wcast-align=strict
+AM_CFLAGS=-Wall -Wextra -Werror -Wundef -Wpedantic

src/bip.c

@@ -1396,9 +1396,10 @@ void adm_print_connection(struct link_client *ic, struct link *lnk,
 	bufpos = buf;
 
 	list_iterator_t itocs;
+	int i = 0;
 	for (list_it_init(&lnk->on_connect_send, &itocs);
-	     list_it_item(&itocs);) {
-		bufpos = bip_strcatf_fit(&remaining, bufpos, "%s",
+		 list_it_item(&itocs) && i < 10; i++) {
+		bufpos = bip_strcatf_fit(&remaining, bufpos, "    on_connect_send: %s",
 					 (char *)list_it_item(&itocs));
 		if (!bufpos) {
 			// if oversized, print and reset
@@ -1406,6 +1407,7 @@ void adm_print_connection(struct link_client *ic, struct link *lnk,
 			bip_notify(ic, "%s", buf);
 			remaining = LINE_SIZE_LIM;
 			bufpos = buf;
+			list_it_next(&itocs);
 			continue;
 		} else {
 			// if ok, go to next item

src/bip_main.c

@@ -68,6 +68,7 @@ void rlimit_cpu_reached(int i);
 void rlimit_bigfile_reached(int i);
 void conf_die(bip_t *bip, char *fmt, ...);
 int fireup(bip_t *bip, FILE *conf);
+int check_ssl_files(int failmode);
 int do_pid_stuff(void);
 
 static void usage(char *name)
@@ -143,6 +144,44 @@ static pid_t daemonize(void)
 	return getpid();
 }
 
+int check_ssl_files(int failmode)
+{
+	int e;
+	struct stat fs;
+
+	if (!conf_ssl_certfile) {
+		conf_ssl_certfile = default_path(
+			conf_biphome, "bip.pem", "SSL certificate");
+	}
+
+	if (failmode == HARD_FAIL)
+		assert_path_exists(conf_ssl_certfile);
+	else if (!check_path_exists(conf_ssl_certfile))
+		return 0;
+
+	e = stat(conf_ssl_certfile, &fs);
+	if (e)
+		mylog(LOG_WARN,
+			  "Unable to check PEM file, stat(%s): %s",
+			  conf_ssl_certfile, strerror(errno));
+	else if ((fs.st_mode & S_IROTH) | (fs.st_mode & S_IWOTH))
+		mylog(LOG_ERROR,
+			  "PEM file %s should not be world "
+			  "readable / writable. Please fix the modes.",
+			  conf_ssl_certfile);
+
+	if (conf_client_dh_file) {
+		if (failmode == HARD_FAIL) {
+			assert_path_exists(conf_client_dh_file);
+		} else if (!check_path_exists(conf_client_dh_file)) {
+			return 0;
+		}
+	}
+
+	/* all is well */
+	return 1;
+}
+
 int main(int argc, char **argv)
 {
 	FILE *conf = NULL;
@@ -264,31 +303,8 @@ int main(int argc, char **argv)
 
 #ifdef HAVE_LIBSSL
 	if (conf_css) {
-		int e;
-		struct stat fs;
-
-		if (!conf_ssl_certfile) {
-			conf_ssl_certfile = default_path(
-				conf_biphome, "bip.pem", "SSL certificate");
-		}
-		assert_path_exists(conf_ssl_certfile);
-
-		e = stat(conf_ssl_certfile, &fs);
-		if (e)
-			mylog(LOG_WARN,
-			      "Unable to check PEM file, stat(%s): "
-			      "%s",
-			      conf_ssl_certfile, strerror(errno));
-		else if ((fs.st_mode & S_IROTH) | (fs.st_mode & S_IWOTH))
-			mylog(LOG_ERROR,
-			      "PEM file %s should not be world "
-			      "readable / writable. Please fix the modes.",
-			      conf_ssl_certfile);
-
-		if (conf_client_dh_file) {
-			assert_path_exists(conf_client_dh_file);
-		}
-	}
+        check_ssl_files(HARD_FAIL);
+    }
 #endif
 
 	check_dir(conf_log_root, 1);
@@ -324,6 +340,24 @@ int main(int argc, char **argv)
 
 		/* re-open to allow logfile rotate */
 		log_file_setup();
+
+#ifdef HAVE_LIBSSL
+		/*
+         * reload SSL context if server-side SSL is enabled and SSL files
+		 * seem accessible.
+         */
+		if (conf_css) {
+			if (check_ssl_files(SOFT_FAIL)) {
+				if (set_ssl_context(SSLCTX_FORCE_UPDATE) == 1)
+				    mylog(LOG_DEBUG, "SSL context has been updated");
+                else
+				    mylog(LOG_DEBUG, "SSL context has not been updated");
+            } else {
+				mylog(LOG_ERROR, "Unable to update SSL context, "
+								"file checks failed");
+            }
+		}
+#endif
 	}
 	return 1;
 }

src/bipmkpw.c

@@ -23,9 +23,9 @@
 #include "util.h"
 #include "md5.h"
 
-int conf_log_level;
-FILE *conf_global_log_file;
-int conf_log_system;
+extern int conf_log_level;
+extern FILE *conf_global_log_file;
+extern int conf_log_system;
 
 void bipmkpw_fatal(char *msg, char *err)
 {

src/connection.c

@@ -34,6 +34,7 @@ extern char *conf_client_ciphers;
 extern char *conf_client_dh_file;
 static int SSLize(connection_t *cn, int *nc);
 static SSL_CTX *SSL_init_context(char *ciphers);
+SSL_CTX *get_ssl_context(void);
 /* SSH like trust management */
 int link_add_untrusted(void *ls, X509 *cert);
 #endif
@@ -62,7 +63,7 @@ void connection_close(connection_t *cn)
 {
 	mylog(LOG_DEBUG, "Connection close asked. FD:%d (status: %d)",
 	      (long)cn->handle, cn->connected);
-	if (cn->connected != CONN_DISCONN && cn->connected != CONN_ERROR) {
+	if (cn->connected != CONN_DISCONN) {
 		cn->connected = CONN_DISCONN;
 		if (close(cn->handle) == -1)
 			mylog(LOG_WARN, "Error on socket close: %s",
@@ -1171,6 +1172,7 @@ static connection_t *connection_init(int anti_flood, int ssl, time_t timeout,
 static int ctx_set_dh(SSL_CTX *ctx)
 {
 	/* Return ephemeral DH parameters. */
+#if OPENSSL_VERSION_NUMBER < 0x30000000L /* 3.0.0 */
 	DH *dh = NULL;
 	FILE *f;
 	long ret;
@@ -1203,9 +1205,104 @@ static int ctx_set_dh(SSL_CTX *ctx)
 		      ERR_error_string(ERR_get_error(), NULL));
 		return 0;
 	}
+#else
+    BIO *pbio = BIO_new_file(conf_client_dh_file, "r");
+    if (!pbio) {
+	    mylog(LOG_ERROR, "Unable to open DH parameters, BIO_new_file(%s): %s",
+                conf_client_dh_file, ERR_error_string(ERR_get_error(), NULL));
+        return 0;
+    }
 
+    EVP_PKEY *param = PEM_read_bio_Parameters(pbio, NULL);
+    BIO_free(pbio);
+    if (!param) {
+	    mylog(LOG_ERROR, "TLS DH Error: PEM_read_bio_Parameters(%s): %s",
+                conf_client_dh_file, ERR_error_string(ERR_get_error(), NULL));
+        return 0;
+    }
+
+    if (SSL_CTX_set0_tmp_dh_pkey(ctx, param) != 1) {
+        EVP_PKEY_free(param);
+	    mylog(LOG_ERROR, "TLS DH Error: SSL_CTX_set0_tmp_dh_pkey(%s): %s",
+                conf_client_dh_file, ERR_error_string(ERR_get_error(), NULL));
+        return 0;
+    }
+#endif
+	mylog(LOG_DEBUG, "TLS: succesfully set up DH params %s",
+            conf_client_dh_file);
 	return 1;
 }
+
+int set_ssl_context(int force)
+{
+	SSL_CTX *newctx = NULL;
+	if (sslctx) {
+		if (force == SSLCTX_FORCE_UPDATE) {
+			mylog(LOG_DEBUG, "SSL context already set, forcing update");
+		} else {
+			mylog(LOG_DEBUG, "SSL context is already set, not updating");
+			return 0;
+		}
+	} else {
+		mylog(LOG_DEBUG, "Initializing SSL context for accepted connections");
+	}
+
+	newctx = get_ssl_context();
+	if (!newctx) {
+		mylog(LOG_ERROR, "Failed to get new SSL context");
+		if (sslctx)
+			mylog(LOG_WARN, "Keeping old SSL context");
+		return 0;
+	}
+	sslctx = newctx;
+	return 1;
+}
+
+SSL_CTX *get_ssl_context(void)
+{
+	SSL_CTX *newctx = NULL;
+	if (!(newctx = SSL_init_context(conf_client_ciphers))) {
+		mylog(LOG_ERROR, "SSL context initialization failed");
+		return NULL;
+	}
+
+	if (!conf_client_dh_file) {
+		// try with a default path but don't fail if it doesn't exist
+		conf_client_dh_file = default_path(conf_biphome, "dh.pem",
+					 "DH parameters");
+
+		struct stat st_buf;
+		if (stat(conf_client_dh_file, &st_buf) != 0) {
+			free(conf_client_dh_file);
+			conf_client_dh_file = NULL;
+		}
+	}
+
+	if (conf_client_dh_file) {
+		if (!ctx_set_dh(newctx)) {
+			SSL_CTX_free(newctx);
+			mylog(LOG_ERROR, "SSL Unable to load DH parameters");
+			return NULL;
+		}
+	}
+
+	mylog(LOG_DEBUG, "Loading SSL cert from %s", conf_ssl_certfile);
+	if (!SSL_CTX_use_certificate_chain_file(newctx, conf_ssl_certfile)) {
+		mylog(LOG_WARN, "SSL: Unable to load certificate file");
+		SSL_CTX_free(newctx);
+		return NULL;
+	}
+
+	mylog(LOG_DEBUG, "Loading SSL key from %s", conf_ssl_certfile);
+	if (!SSL_CTX_use_PrivateKey_file(newctx, conf_ssl_certfile,
+					 SSL_FILETYPE_PEM)) {
+		mylog(LOG_WARN, "SSL: Unable to load key file");
+		SSL_CTX_free(newctx);
+		return NULL;
+	}
+
+	return newctx;
+}
 #endif
 
 connection_t *accept_new(connection_t *cn)
@@ -1241,52 +1338,11 @@ connection_t *accept_new(connection_t *cn)
 	conn->client = 1;
 #ifdef HAVE_LIBSSL
 	if (cn->ssl) {
+		if (!sslctx)
+			set_ssl_context(SSLCTX_NO_REPLACE);
 		if (!sslctx) {
-			mylog(LOG_DEBUG,
-			      "No SSL context available for "
-			      "accepted connections. "
-			      "Initializing...");
-			if (!(sslctx = SSL_init_context(conf_client_ciphers))) {
-				mylog(LOG_ERROR,
-				      "SSL context initialization "
-				      "failed");
-				connection_free(conn);
-				return NULL;
-			}
-
-			if (!conf_client_dh_file) {
-				// try with a default path but don't fail if it
-				// doesn't exist
-				conf_client_dh_file =
-					default_path(conf_biphome, "dh.pem",
-						     "DH parameters");
-
-				struct stat st_buf;
-				if (stat(conf_client_dh_file, &st_buf) != 0) {
-					free(conf_client_dh_file);
-					conf_client_dh_file = NULL;
-				}
-			}
-
-			if (conf_client_dh_file) {
-				if (!ctx_set_dh(sslctx)) {
-					mylog(LOG_ERROR,
-					      "SSL Unable to load DH "
-					      "parameters");
-					connection_free(conn);
-					return NULL;
-				}
-			}
-
-			if (!SSL_CTX_use_certificate_chain_file(
-				    sslctx, conf_ssl_certfile))
-				mylog(LOG_WARN,
-				      "SSL: Unable to load "
-				      "certificate file");
-			if (!SSL_CTX_use_PrivateKey_file(sslctx,
-							 conf_ssl_certfile,
-							 SSL_FILETYPE_PEM))
-				mylog(LOG_WARN, "SSL: Unable to load key file");
+			connection_free(conn);
+			return NULL;
 		}
 
 		conn->ssl_h = SSL_new(sslctx);

src/connection.h

@@ -60,6 +60,9 @@
 #define SSL_CHECK_NONE (0)
 #define SSL_CHECK_BASIC (1)
 #define SSL_CHECK_CA (2)
+
+#define SSLCTX_NO_REPLACE 0
+#define SSLCTX_FORCE_UPDATE 1
 #endif
 
 struct connecting_data;
@@ -113,4 +116,9 @@ uint16_t connection_localport(connection_t *cn);
 uint16_t connection_remoteport(connection_t *cn);
 char *connection_localip(connection_t *cn);
 char *connection_remoteip(connection_t *cn);
+#ifdef HAVE_LIBSSL
+/* Set SSL context, force update if already set and force is 1
+ * Return 1 if SSL context has been set */
+int set_ssl_context(int force);
+#endif
 #endif

src/irc.c

@@ -1030,6 +1030,31 @@ static int irc_cli_pass(bip_t *bip, struct link_client *ic, struct line *line)
 	return OK_FORGET;
 }
 
+static int irc_cli_cap(bip_t *bip, struct link_client *ic, struct line *line)
+{
+	if (irc_line_count(line) < 2)
+		return ERR_PROTOCOL;
+
+	/* When we decide to enable actual capabilities, we'll have to handle CAP
+	 * version, add a flag cap_started or similar, and handle CAP END.
+	 */
+	if (irc_line_elem_equals(line, 1, "LS")) {
+		WRITE_LINE2(CONN(ic), NULL, "CAP", "*", "LS");
+	} else if (irc_line_elem_equals(line, 1, "LIST")) {
+		WRITE_LINE3(CONN(ic), NULL, "CAP", "*", "LIST", "");
+	} else if (irc_line_elem_equals(line, 1, "REQ")) {
+		char *caps = irc_line_to_string_skip(line, 2);
+		if (caps) {
+			caps++;
+			WRITE_LINE3(CONN(ic), NULL, "CAP", "*", "NAK", caps);
+		}
+	}
+
+	if ((ic->state & IRCC_READY) == IRCC_READY)
+		return irc_cli_startup(bip, ic, line);
+	return OK_FORGET;
+}
+
 static int irc_cli_quit(struct link_client *ic, struct line *line)
 {
 	(void)ic;
@@ -1408,6 +1433,8 @@ static int irc_dispatch_logging_client(bip_t *bip, struct link_client *ic,
 		return irc_cli_user(bip, ic, line);
 	} else if (irc_line_elem_equals(line, 0, "PASS")) {
 		return irc_cli_pass(bip, ic, line);
+	} else if (irc_line_elem_equals(line, 0, "CAP")) {
+		return irc_cli_cap(bip, ic, line);
 	}
 	return OK_FORGET;
 }

src/line.c

@@ -16,6 +16,8 @@
 #include "line.h"
 #include "util.h"
 
+char *_irc_line_to_string(struct line *l, int skip_first);
+
 // TODO resolve assuming signed overflow does not occur when changing X +- C1
 // cmp C2 to X cmp C2 -+ C1
 #pragma GCC diagnostic ignored "-Wstrict-overflow"
@@ -76,6 +78,19 @@ void irc_line_append(struct line *l, const char *s)
 }
 
 char *irc_line_to_string(struct line *l)
+{
+    return _irc_line_to_string(l, 0);
+}
+
+char *irc_line_to_string_skip(struct line *l, int skip_first)
+{
+    if (skip_first >= irc_line_count(l)) {
+        return NULL;
+    }
+    return _irc_line_to_string(l, skip_first);
+}
+
+char *_irc_line_to_string(struct line *l, int skip_first)
 {
 	size_t len = 0;
 	int i;
@@ -83,7 +98,7 @@ char *irc_line_to_string(struct line *l)
 
 	if (l->origin)
 		len = strlen(l->origin) + 2;
-	for (i = 0; i < array_count(&l->words); i++)
+	for (i = skip_first; i < array_count(&l->words); i++)
 		len += strlen(array_get(&l->words, i)) + 1;
 	len += 1; /* remove one trailing space and add \r\n */
 	len++;	  /* last args ":" */
@@ -95,7 +110,7 @@ char *irc_line_to_string(struct line *l)
 		strcat(ret, l->origin);
 		strcat(ret, " ");
 	}
-	for (i = 0; i < array_count(&l->words) - 1; i++) {
+	for (i = skip_first; i < array_count(&l->words) - 1; i++) {
 		strcat(ret, array_get(&l->words, i));
 		strcat(ret, " ");
 	}

src/line.h

@@ -90,6 +90,7 @@ void irc_line_write(struct line *l, connection_t *c);
 void irc_line_append(struct line *l, const char *s);
 struct line *irc_line_new_from_string(char *str);
 char *irc_line_to_string(struct line *l);
+char *irc_line_to_string_skip(struct line *l, int skip_first);
 char *irc_line_to_string_to(struct line *line, char *nick);
 void irc_line_free(struct line *l);
 struct line *irc_line_dup(struct line *line);

src/path_util.c

@@ -35,3 +35,15 @@ void assert_path_exists(char *path)
 	if (stat(path, &st_buf) != 0)
 		fatal("Path %s doesn't exist (%s)", path, strerror(errno));
 }
+
+int check_path_exists(char *path)
+{
+	struct stat st_buf;
+
+	if (stat(path, &st_buf) != 0) {
+		mylog(LOG_WARN, "Path %s doesn't exist (%s)", path, strerror(errno));
+        return 0;
+    } else {
+        return 1;
+    }
+}

src/path_util.h

@@ -18,5 +18,7 @@
 char *default_path(const char *biphome, const char *filename, const char *desc);
 /* exit program if path doesn't exist */
 void assert_path_exists(char *path);
+/* return 1 if path exists, 0 otherwise */
+int check_path_exists(char *path);
 
 #endif

src/util.h

@@ -31,6 +31,9 @@
 #define HASH_NOCASE 1
 #define HASH_DEFAULT 0
 
+#define SOFT_FAIL 0
+#define HARD_FAIL 1
+
 void mylog(int level, char *fmt, ...);
 void _mylog(int level, char *fmt, va_list ap);
 void fatal(char *fmt, ...);