9a9edf200

Denis Vlasenko

2006-09-08

SOURCE BUG Duration: 53s

Subject

SOURCE BUG

This commit was genuinely broken at the time (not related to our build system): scripts/config/mkconfigs.c (2005-08-01 - 2006-10-05 arasi) uretilen bbconfigopts.h icine .config satirlarini kacissiz, ham newline'larla gömüyordu - gecerli C degildi, busybox'un kendi bb_mkdep araci bile parse edemiyordu (7d219aab7 ile duzeltildi, mkconfigs shell scripte cevrildi)

→ Bu hatanin tam hikayesini ve duzeltme diffini gor

Binary

No binary (build failed)

Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

Build Log

(log yok)

Commit Diff GitHub →

loginutils/login.c +131 -185

loginutils/login.c+131 -185

@@ -29,59 +29,59 @@

	#ifdef CONFIG_FEATURE_UTMP
	// import from utmp.c
-	static void checkutmp(int picky);
-	static void setutmp(const char name, const char line);
-	/* Stuff global to this file */
	static struct utmp utent;
+	static void read_or_build_utent(int picky);
+	static void write_utent(const char *username);
	#endif

	enum {
	TIMEOUT = 60,
	EMPTY_USERNAME_COUNT = 10,
	USERNAME_SIZE = 32,
+	TTYNAME_SIZE = 32,
	};

-	static int check_nologin(int amroot);
+	static void die_if_nologin_and_non_root(int amroot);

	#if defined CONFIG_FEATURE_SECURETTY
-	static int check_tty(const char *tty);
+	static int check_securetty(void);

	#else
-	static inline int check_tty(const char *tty) { return 1; }
+	static inline int check_securetty(void) { return 1; }

	#endif

-	static int is_my_tty(const char *tty);
-	static int login_prompt(char *buf_name);
+	static int is_my_tty(void);
+	static void get_username_or_die(char *buf, int size_buf);
	static void motd(void);


	static void alarm_handler(int sig ATTRIBUTE_UNUSED)
	{
-	fprintf(stderr, "\r\nLogin timed out after %s seconds\r\n", TIMEOUT);
+	fprintf(stderr, "\r\nLogin timed out after %d seconds\r\n", TIMEOUT);
	exit(EXIT_SUCCESS);
	}


+	static char full_tty[TTYNAME_SIZE];
+	static char* short_tty = full_tty;
+
+
	int login_main(int argc, char **argv)
	{
-	char tty[BUFSIZ];
-	char full_tty[200];
	char fromhost[512];
	char username[USERNAME_SIZE];
	const char *tmp;
	int amroot;
	int flag;
-	int failed;
	int count = 0;
-	struct passwd *pw, pw_copy;
+	struct passwd *pw;
	#ifdef CONFIG_WHEEL_GROUP
	struct group *grp;
	#endif
	int opt_preserve = 0;
	int opt_fflag = 0;
	char *opt_host = 0;
-	int alarmstarted = 0;
	#ifdef CONFIG_SELINUX
	security_context_t user_sid = NULL;
	#endif
@@ -90,7 +90,6 @@ int login_main(int argc, char **argv)
	amroot = (getuid() == 0);
	signal(SIGALRM, alarm_handler);
	alarm(TIMEOUT);
-	alarmstarted = 1;

	while ((flag = getopt(argc, argv, "f:h:p")) != EOF) {
	switch (flag) {
@@ -105,10 +104,10 @@ int login_main(int argc, char **argv)
	if (optarg != argv[optind-1])
	bb_show_usage();

-	if (!amroot) /* Auth bypass only if real UID is zero */
-	bb_error_msg_and_die("-f permission denied");
+	if (!amroot) /* Auth bypass only if real UID is zero */
+	bb_error_msg_and_die("-f is for root only");

-	safe_strncpy(username, optarg, USERNAME_SIZE);
+	safe_strncpy(username, optarg, sizeof(username));
	opt_fflag = 1;
	break;
	case 'h':
@@ -118,113 +117,83 @@ int login_main(int argc, char **argv)
	bb_show_usage();
	}
	}
-
	if (optind < argc) /* user from command line (getty) */
-	safe_strncpy(username, argv[optind], USERNAME_SIZE);
+	safe_strncpy(username, argv[optind], sizeof(username));

+	/* Let's find out and memorize our tty */
	if (!isatty(0) \|\| !isatty(1) \|\| !isatty(2))
	return EXIT_FAILURE; /* Must be a terminal */
-
-	#ifdef CONFIG_FEATURE_UTMP
-	checkutmp(!amroot);
-	#endif
-
+	safe_strncpy(full_tty, "UNKNOWN", sizeof(full_tty));
	tmp = ttyname(0);
-	if (tmp && (strncmp(tmp, "/dev/", 5) == 0))
-	safe_strncpy(tty, tmp + 5, sizeof(tty));
-	else if (tmp && *tmp == '/')
-	safe_strncpy(tty, tmp, sizeof(tty));
-	else
-	safe_strncpy(tty, "UNKNOWN", sizeof(tty));
+	if (tmp) {
+	safe_strncpy(full_tty, tmp, sizeof(full_tty));
+	if (strncmp(full_tty, "/dev/", 5) == 0)
+	short_tty = full_tty + 5;
+	}

-	#ifdef CONFIG_FEATURE_UTMP
-	if (amroot)
-	memset(utent.ut_host, 0, sizeof(utent.ut_host));
-	#endif
+	if (ENABLE_FEATURE_UTMP) {
+	read_or_build_utent(!amroot);
+	if (amroot)
+	memset(utent.ut_host, 0, sizeof(utent.ut_host));
+	}

	if (opt_host) {
-	#ifdef CONFIG_FEATURE_UTMP
-	safe_strncpy(utent.ut_host, opt_host, sizeof(utent.ut_host));
-	#endif
+	if (ENABLE_FEATURE_UTMP)
+	safe_strncpy(utent.ut_host, opt_host, sizeof(utent.ut_host));
	snprintf(fromhost, sizeof(fromhost)-1, " on `%.100s' from "
-	"`%.200s'", tty, opt_host);
+	"`%.200s'", short_tty, opt_host);
	}
	else
-	snprintf(fromhost, sizeof(fromhost)-1, " on `%.100s'", tty);
+	snprintf(fromhost, sizeof(fromhost)-1, " on `%.100s'", short_tty);

	bb_setpgrp;

	openlog(bb_applet_name, LOG_PID \| LOG_CONS \| LOG_NOWAIT, LOG_AUTH);

	while (1) {
-	failed = 0;
-
	if (!username[0])
-	if (!login_prompt(username))
-	return EXIT_FAILURE;
-
-	if (!alarmstarted && (TIMEOUT > 0)) {
-	alarm(TIMEOUT);
-	alarmstarted = 1;
-	}
+	get_username_or_die(username, sizeof(username));

	pw = getpwnam(username);
	if (!pw) {
-	pw_copy.pw_name = "UNKNOWN";
-	pw_copy.pw_passwd = "!";
-	opt_fflag = 0;
-	failed = 1;
-	} else
-	pw_copy = *pw;
-
-	pw = &pw_copy;
+	safe_strncpy(username, "UNKNOWN", sizeof(username));
+	goto auth_failed;
+	}

-	if ((pw->pw_passwd[0] == '!') \|\| (pw->pw_passwd[0] == '*'))
-	failed = 1;
+	if (pw->pw_passwd[0] == '!' \|\| pw->pw_passwd[0] == '*')
+	goto auth_failed;

-	if (opt_fflag) {
-	opt_fflag = 0;
-	goto auth_ok;
-	}
+	if (opt_fflag)
+	break; /* -f USER: success without asking passwd */

-	if (!failed && (pw->pw_uid == 0) && (!check_tty(tty)))
-	failed = 1;
+	if (pw->pw_uid == 0 && !check_securetty())
+	goto auth_failed;

	/* Don't check the password if password entry is empty (!) */
	if (!pw->pw_passwd[0])
-	goto auth_ok;
+	break;

	/* authorization takes place here */
	if (correct_password(pw))
-	goto auth_ok;
-
-	failed = 1;
-
-	auth_ok:
-	if (!failed)
-	break;
+	break;

+	auth_failed:
+	opt_fflag = 0;
	bb_do_delay(FAIL_DELAY);
	puts("Login incorrect");
-	username[0] = 0;
	if (++count == 3) {
-	syslog(LOG_WARNING, "invalid password for `%s'%s", pw->pw_name, fromhost);
+	syslog(LOG_WARNING, "invalid password for `%s'%s",
+	username, fromhost);
	return EXIT_FAILURE;
	}
+	username[0] = '\0';
	}

	alarm(0);
-	if (check_nologin(pw->pw_uid == 0))
-	return EXIT_FAILURE;
-
-	#ifdef CONFIG_FEATURE_UTMP
-	setutmp(username, tty);
-	#endif
+	die_if_nologin_and_non_root(pw->pw_uid == 0);

-	if (*tty != '/')
-	snprintf(full_tty, sizeof(full_tty)-1, "/dev/%s", tty);
-	else
-	safe_strncpy(full_tty, tty, sizeof(full_tty)-1);
+	if (ENABLE_FEATURE_UTMP)
+	write_utent(username);

	#ifdef CONFIG_SELINUX
	if (is_selinux_enabled()) {
@@ -249,7 +218,7 @@ auth_ok:
	}
	}
	#endif
-	if (!is_my_tty(full_tty))
+	if (!is_my_tty())
	syslog(LOG_ERR, "unable to determine TTY name, got %s", full_tty);

	/* Try these, but don't complain if they fail
@@ -300,96 +269,91 @@ auth_ok:
	}


-	static int login_prompt(char *buf_name)
+	static void get_username_or_die(char *buf, int size_buf)
	{
-	char buf[1024];
-	char sp, ep;
-	int i;
-
-	for (i=0; i<EMPTY_USERNAME_COUNT; i++) {
-	print_login_prompt();
-
-	if (!fgets(buf, sizeof(buf)-1, stdin))
-	return 0;
-
-	if (!strchr(buf, '\n'))
-	return 0;
-
-	for (sp = buf; isspace(*sp); sp++) { }
-	for (ep = sp; isgraph(*ep); ep++) { }
-
-	*ep = '\0';
-	safe_strncpy(buf_name, sp, USERNAME_SIZE);
-	if (buf_name[0])
-	return 1;
-	}
-	return 0;
+	int c, cntdown;
+	cntdown = EMPTY_USERNAME_COUNT;
+	prompt:
+	/* skip whitespace */
+	print_login_prompt();
+	do {
+	c = getchar();
+	if (c == EOF) exit(1);
+	if (c == '\n') {
+	if (!--cntdown) exit(1);
+	goto prompt;
+	}
+	} while (isspace(c));
+
+	*buf++ = c;
+	if (!fgets(buf, size_buf-2, stdin))
+	exit(1);
+	if (!strchr(buf, '\n'))
+	exit(1);
+	while (isgraph(*buf)) buf++;
+	*buf = '\0';
	}


-	static int check_nologin(int amroot)
+	static void die_if_nologin_and_non_root(int amroot)
	{
-	if (access(bb_path_nologin_file, F_OK) == 0) {
-	FILE *fp;
-	int c;
-
-	fp = fopen(bb_path_nologin_file, "r");
-	if (fp) {
-	while ((c = getc(fp)) != EOF)
-	putchar((c=='\n') ? '\r' : c);
+	FILE *fp;
+	int c;

-	fflush(stdout);
-	fclose(fp);
-	} else {
-	puts("\r\nSystem closed for routine maintenance.\r");
-	}
-	if (!amroot)
-	return 1;
+	if (access(bb_path_nologin_file, F_OK))
+	return;

-	puts("\r\n[Disconnect bypassed -- root login allowed.]\r");
-	}
-	return 0;
+	fp = fopen(bb_path_nologin_file, "r");
+	if (fp) {
+	while ((c = getc(fp)) != EOF)
+	putchar((c=='\n') ? '\r' : c);
+	fflush(stdout);
+	fclose(fp);
+	} else
+	puts("\r\nSystem closed for routine maintenance\r");
+	if (!amroot)
+	exit(1);
+	puts("\r\n[Disconnect bypassed -- root login allowed.]\r");
	}

	#ifdef CONFIG_FEATURE_SECURETTY

-	static int check_tty(const char *tty)
+	static int check_securetty(void)
	{
	FILE *fp;
	int i;
	char buf[BUFSIZ];

	fp = fopen(bb_path_securetty_file, "r");
-	if (fp) {
-	while (fgets(buf, sizeof(buf)-1, fp)) {
-	for(i = strlen(buf)-1; i>=0; --i) {
-	if (!isspace(buf[i]))
-	break;
-	}
-	buf[++i] = '\0';
-	if ((buf[0]=='\0') \|\| (buf[0]=='#'))
-	continue;
-
-	if (strcmp(buf, tty)== 0) {
-	fclose(fp);
-	return 1;
-	}
+	if (!fp) {
+	/* A missing securetty file is not an error. */
+	return 1;
+	}
+	while (fgets(buf, sizeof(buf)-1, fp)) {
+	for(i = strlen(buf)-1; i>=0; --i) {
+	if (!isspace(buf[i]))
+	break;
+	}
+	buf[++i] = '\0';
+	if ((buf[0]=='\0') \|\| (buf[0]=='#'))
+	continue;
+	if (strcmp(buf, short_tty) == 0) {
+	fclose(fp);
+	return 1;
	}
-	fclose(fp);
-	return 0;
	}
-	/* A missing securetty file is not an error. */
-	return 1;
+	fclose(fp);
+	return 0;
	}

	#endif

	/* returns 1 if true */
-	static int is_my_tty(const char *tty)
+	static int is_my_tty(void)
	{
	struct stat by_name, by_fd;

-	if (stat(tty, &by_name) \|\| fstat(0, &by_fd))
+	if (stat(full_tty, &by_name) \|\| fstat(0, &by_fd))
	return 0;

	if (by_name.st_rdev != by_fd.st_rdev)
@@ -414,15 +378,10 @@ static void motd(void)


	#ifdef CONFIG_FEATURE_UTMP
-	// vv Taken from tinylogin utmp.c vv
-
-	#define NO_UTENT \
-	"No utmp entry. You must exec \"login\" from the lowest level \"sh\""
-	#define NO_TTY \
-	"Unable to determine your tty name."
+	/* vv Taken from tinylogin utmp.c vv */

	/*
-	* checkutmp - see if utmp file is correct for this process
+	* read_or_build_utent - see if utmp file is correct for this process
	*
	* System V is very picky about the contents of the utmp file
	* and requires that a slot for the current process exist.
@@ -435,9 +394,8 @@ static void motd(void)
	* command line flags.
	*/

-	static void checkutmp(int picky)
+	static void read_or_build_utent(int picky)
	{
-	char *line;
	struct utmp *ut;
	pid_t pid = getpid();

@@ -446,53 +404,41 @@ static void checkutmp(int picky)
	/* First, try to find a valid utmp entry for this process. */
	while ((ut = getutent()))
	if (ut->ut_pid == pid && ut->ut_line[0] && ut->ut_id[0] &&
-	(ut->ut_type == LOGIN_PROCESS \|\| ut->ut_type == USER_PROCESS))
+	(ut->ut_type == LOGIN_PROCESS \|\| ut->ut_type == USER_PROCESS))
	break;

	/* If there is one, just use it, otherwise create a new one. */
	if (ut) {
	utent = *ut;
	} else {
-	time_t t_tmp;
-
-	if (picky) {
-	puts(NO_UTENT);
-	exit(1);
-	}
-	line = ttyname(0);
-	if (!line) {
-	puts(NO_TTY);
-	exit(1);
-	}
-	if (strncmp(line, "/dev/", 5) == 0)
-	line += 5;
+	if (picky)
+	bb_error_msg_and_die("no utmp entry found");
+
	memset(&utent, 0, sizeof(utent));
	utent.ut_type = LOGIN_PROCESS;
	utent.ut_pid = pid;
-	strncpy(utent.ut_line, line, sizeof(utent.ut_line));
-	/* XXX - assumes /dev/tty?? */
-	strncpy(utent.ut_id, utent.ut_line + 3, sizeof(utent.ut_id));
+	strncpy(utent.ut_line, short_tty, sizeof(utent.ut_line));
+	/* This one is only 4 chars wide. Try to fit something
+	* remotely meaningful by skipping "tty"... */
+	strncpy(utent.ut_id, short_tty + 3, sizeof(utent.ut_id));
	strncpy(utent.ut_user, "LOGIN", sizeof(utent.ut_user));
-	t_tmp = (time_t)utent.ut_time;
-	time(&t_tmp);
+	utent.ut_time = time(NULL);
	}
	}

	/*
-	* setutmp - put a USER_PROCESS entry in the utmp file
+	* write_utent - put a USER_PROCESS entry in the utmp file
	*
-	* setutmp changes the type of the current utmp entry to
+	* write_utent changes the type of the current utmp entry to
	* USER_PROCESS. the wtmp file will be updated as well.
	*/

-	static void setutmp(const char name, const char line ATTRIBUTE_UNUSED)
+	static void write_utent(const char *username)
	{
-	time_t t_tmp = (time_t)utent.ut_time;
-
	utent.ut_type = USER_PROCESS;
-	strncpy(utent.ut_user, name, sizeof(utent.ut_user));
-	time(&t_tmp);
-	/* other fields already filled in by checkutmp above */
+	strncpy(utent.ut_user, username, sizeof(utent.ut_user));
+	utent.ut_time = time(NULL);
+	/* other fields already filled in by read_or_build_utent above */
	setutent();
	pututline(&utent);
	endutent();