*: intrduce and use safe_gethostname. By Tito <farmatito AT tiscali.it>

safe_gethostname                                       -      48     +48
glob3                                                 35      37      +2
timestamp_and_log                                    314     315      +1
udhcp_send_kernel_packet                             234     231      -3
scan_tree                                            275     271      -4
passwd_main                                         1074    1070      -4
print_login_prompt                                    68      58     -10
obscure                                              392     377     -15
syslogd_main                                         882     866     -16
print_login_issue                                    516     478     -38
hostname_main                                        278     223     -55
parse_and_put_prompt                                 825     756     -69
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 2/9 up/down: 51/-214)          Total: -163 bytes
   text    data     bss     dec     hex filename
 798791     728    7484  807003   c505b busybox_old
 798631     728    7484  806843   c4fbb busybox_unstripped

include/libbb.h

@@ -550,6 +550,8 @@ extern FILE *fopen_or_warn_stdin(const char *filename);
  * If this is a problem, use bare poll and open-code EINTR/ENOMEM handling */
 int safe_poll(struct pollfd *ufds, nfds_t nfds, int timeout_ms);
 
+char *safe_gethostname(void);
+
 /* Convert each alpha char in str to lower-case */
 char* str_tolower(char *str);
 

libbb/Kbuild

@@ -73,6 +73,7 @@ lib-y += recursive_action.o
 lib-y += remove_file.o
 lib-y += restricted_shell.o
 lib-y += run_shell.o
+lib-y += safe_gethostname.o
 lib-y += safe_poll.o
 lib-y += safe_strncpy.o
 lib-y += safe_write.o

libbb/lineedit.c

@@ -1203,11 +1203,7 @@ static void parse_and_put_prompt(const char *prmt_ptr)
 					break;
 #endif
 				case 'h':
-					pbuf = free_me = xzalloc(256);
+					pbuf = free_me = safe_gethostname();
-					if (gethostname(pbuf, 255) < 0) {
-						pbuf[0] = '?';
-						pbuf[1] = '\0';
-					}
 					*strchrnul(pbuf, '.') = '\0';
 					break;
 				case '$':

libbb/login.c

@@ -50,6 +50,7 @@ void print_login_issue(const char *issue_file, const char *tty)
 				outbuf = uts.sysname;
 				break;
 			case 'n':
+			case 'h':
 				outbuf = uts.nodename;
 				break;
 			case 'r':
@@ -72,10 +73,6 @@ void print_login_issue(const char *issue_file, const char *tty)
 			case 't':
 				strftime(buf, sizeof(buf), fmtstr_t, localtime(&t));
 				break;
-			case 'h':
-				gethostname(buf, sizeof(buf) - 1);
-				buf[sizeof(buf) - 1] = '\0';
-				break;
 			case 'l':
 				outbuf = tty;
 				break;
@@ -91,13 +88,12 @@ void print_login_issue(const char *issue_file, const char *tty)
 
 void print_login_prompt(void)
 {
-	char buf[MAXHOSTNAMELEN+1];
+	char *hostname = safe_gethostname();
-
+	
-	if (gethostname(buf, MAXHOSTNAMELEN) == 0)
+	fputs(hostname, stdout);
-		fputs(buf, stdout);
-
 	fputs(LOGIN, stdout);
 	fflush(stdout);
+	free(hostname);
 }
 
 /* Clear dangerous stuff, set PATH */

libbb/obscure.c

@@ -93,7 +93,7 @@ static const char *obscure_msg(const char *old_p, const char *new_p, const struc
 	/* Add 2 for each type of characters to the minlen of password */
 	int size = CONFIG_PASSWORD_MINLEN + 8;
 	const char *p;
-	char hostname[255];
+	char *hostname;
 
 	/* size */
 	if (!new_p || (length = strlen(new_p)) < CONFIG_PASSWORD_MINLEN)
@@ -108,12 +108,11 @@ static const char *obscure_msg(const char *old_p, const char *new_p, const struc
 		return "similar to gecos";
 	}
 	/* hostname as-is, as sub-string, reversed, capitalized, doubled */
-	if (gethostname(hostname, 255) == 0) {
+	hostname = safe_gethostname();
-		hostname[254] = '\0';
+	i = string_checker(new_p, hostname);
-		if (string_checker(new_p, hostname)) {
+	free(hostname);
-			return "similar to hostname";
+	if (i)
-		}
+		return "similar to hostname";
-	}
 
 	/* Should / Must contain a mix of: */
 	for (i = 0; i < length; i++) {

miscutils/devfsd.c

@@ -1133,8 +1133,8 @@ static void signal_handler(int sig)
 static const char *get_variable(const char *variable, void *info)
 {
 	static char sbuf[sizeof(int)*3 + 2]; /* sign and NUL */
+	static char *hostname;
 
-	char hostname[STRING_LENGTH];
 	struct get_variable_info *gv_info = info;
 	const char *field_names[] = {
 			"hostname", "mntpt", "devpath", "devname",
@@ -1143,12 +1143,8 @@ static const char *get_variable(const char *variable, void *info)
 	};
 	int i;
 
-	if (gethostname(hostname, STRING_LENGTH - 1) != 0)
+	if (!hostname)
-		/* Here on error we should do exit(RV_SYS_ERROR), instead we do exit(EXIT_FAILURE) */
+		hostname = safe_gethostname();
-		error_logger_and_die(LOG_ERR, "gethostname");
-
-	hostname[STRING_LENGTH - 1] = '\0';
-
 	/* index_in_str_array returns i>=0  */
 	i = index_in_str_array(field_names, variable);
 

networking/hostname.c

@@ -24,8 +24,7 @@ static void do_sethostname(char *s, int isfile)
 		if (sethostname(s, strlen(s)) < 0) {
 			if (errno == EPERM)
 				bb_error_msg_and_die(bb_msg_perm_denied_are_you_root);
-			else
+			bb_perror_msg_and_die("sethostname");
-				bb_perror_msg_and_die("sethostname");
 		}
 	} else {
 		f = xfopen(s, "r");
@@ -54,27 +53,27 @@ int hostname_main(int argc, char **argv)
 		OPT_dfis = 0xf,
 	};
 
-	char buf[256];
+	char *buf;
 	char *hostname_str;
 
 	if (argc < 1)
 		bb_show_usage();
 
 	getopt32(argv, "dfisF:", &hostname_str);
+	argv += optind;
+	buf = safe_gethostname();
 
 	/* Output in desired format */
 	if (option_mask32 & OPT_dfis) {
 		struct hostent *hp;
 		char *p;
-		gethostname(buf, sizeof(buf));
 		hp = xgethostbyname(buf);
 		p = strchr(hp->h_name, '.');
 		if (option_mask32 & OPT_f) {
 			puts(hp->h_name);
 		} else if (option_mask32 & OPT_s) {
-			if (p != NULL) {
+			if (p)
 				*p = '\0';
-			}
 			puts(hp->h_name);
 		} else if (option_mask32 & OPT_d) {
 			if (p)
@@ -89,14 +88,15 @@ int hostname_main(int argc, char **argv)
 	/* Set the hostname */
 	else if (option_mask32 & OPT_F) {
 		do_sethostname(hostname_str, 1);
-	} else if (optind < argc) {
+	} else if (argv[0]) {
-		do_sethostname(argv[optind], 0);
+		do_sethostname(argv[0], 0);
 	}
 	/* Or if all else fails,
 	 * just print the current hostname */
 	else {
-		gethostname(buf, sizeof(buf));
 		puts(buf);
 	}
+	if (ENABLE_FEATURE_CLEAN_UP)
+		free(buf);
 	return 0;
 }

sysklogd/syslogd.c

@@ -97,8 +97,8 @@ struct globals {
 	struct shbuf_ds *shbuf;
 #endif
 	time_t last_log_time;
-	/* localhost's name */
+	/* localhost's name. We print only first 64 chars */
-	char localHostName[64];
+	char *hostname;
 
 	/* We recv into recvbuf... */
 	char recvbuf[MAX_READ];
@@ -416,7 +416,7 @@ static void timestamp_and_log(int pri, char *msg, int len)
 	else {
 		char res[20];
 		parse_fac_prio_20(pri, res);
-		sprintf(G.printbuf, "%s %s %s %s\n", timestamp, G.localHostName, res, msg);
+		sprintf(G.printbuf, "%s %.64s %s %s\n", timestamp, G.hostname, res, msg);
 	}
 
 	/* Log message locally (to file or shared mem) */
@@ -647,11 +647,8 @@ int syslogd_main(int argc, char **argv)
 		option_mask32 |= OPT_locallog;
 
 	/* Store away localhost's name before the fork */
-	/* "It is unspecified whether the truncated hostname
+	G.hostname = safe_gethostname();
-	 * will be null-terminated". We give it (size - 1),
+	*strchrnul(G.hostname, '.') = '\0';
-	 * thus last byte will be NUL no matter what. */
-	gethostname(G.localHostName, sizeof(G.localHostName) - 1);
-	*strchrnul(G.localHostName, '.') = '\0';
 
 	if (!(option_mask32 & OPT_nofork)) {
 		bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);