#include <sys/resource.h>
#include <syslog.h>
-#ifdef CONFIG_SELINUX
+#if ENABLE_SELINUX
#include <selinux/selinux.h> /* for is_selinux_enabled() */
#include <selinux/get_context_list.h> /* for get_default_context() */
#include <selinux/flask.h> /* for security class definitions */
TTYNAME_SIZE = 32,
};
-static char full_tty[TTYNAME_SIZE];
-static char* short_tty = full_tty;
+static char* short_tty;
#if ENABLE_FEATURE_UTMP
/* vv Taken from tinylogin utmp.c vv */
* This means that getty should never invoke login with any
* command line flags.
*/
-static struct utmp utent;
-static void read_or_build_utent(int picky)
+
+static void read_or_build_utent(struct utmp *utptr, int picky)
{
struct utmp *ut;
pid_t pid = getpid();
/* If there is one, just use it, otherwise create a new one. */
if (ut) {
- utent = *ut;
+ *utptr = *ut;
} else {
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, short_tty, sizeof(utent.ut_line));
+ memset(utptr, 0, sizeof(*utptr));
+ utptr->ut_type = LOGIN_PROCESS;
+ utptr->ut_pid = pid;
+ strncpy(utptr->ut_line, short_tty, sizeof(utptr->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));
- utent.ut_time = time(NULL);
+ strncpy(utptr->ut_id, short_tty + 3, sizeof(utptr->ut_id));
+ strncpy(utptr->ut_user, "LOGIN", sizeof(utptr->ut_user));
+ utptr->ut_time = time(NULL);
}
if (!picky) /* root login */
- memset(utent.ut_host, 0, sizeof(utent.ut_host));
+ memset(utptr->ut_host, 0, sizeof(utptr->ut_host));
}
/*
* write_utent changes the type of the current utmp entry to
* USER_PROCESS. the wtmp file will be updated as well.
*/
-static void write_utent(const char *username)
+static void write_utent(struct utmp *utptr, const char *username)
{
- utent.ut_type = USER_PROCESS;
- strncpy(utent.ut_user, username, sizeof(utent.ut_user));
- utent.ut_time = time(NULL);
+ utptr->ut_type = USER_PROCESS;
+ strncpy(utptr->ut_user, username, sizeof(utptr->ut_user));
+ utptr->ut_time = time(NULL);
/* other fields already filled in by read_or_build_utent above */
setutent();
- pututline(&utent);
+ pututline(utptr);
endutent();
#if ENABLE_FEATURE_WTMP
if (access(bb_path_wtmp_file, R_OK|W_OK) == -1) {
close(creat(bb_path_wtmp_file, 0664));
}
- updwtmp(bb_path_wtmp_file, &utent);
+ updwtmp(bb_path_wtmp_file, utptr);
#endif
}
-#else /* !CONFIG_FEATURE_UTMP */
-static inline void read_or_build_utent(int) {}
-static inline void write_utent(const char *) {}
-#endif /* !CONFIG_FEATURE_UTMP */
+#else /* !ENABLE_FEATURE_UTMP */
+#define read_or_build_utent(utptr, picky) ((void)0)
+#define write_utent(utptr, username) ((void)0)
+#endif /* !ENABLE_FEATURE_UTMP */
static void die_if_nologin_and_non_root(int amroot)
{
return 1;
}
while (fgets(buf, sizeof(buf)-1, fp)) {
- for(i = strlen(buf)-1; i>=0; --i) {
+ for (i = strlen(buf)-1; i>=0; --i) {
if (!isspace(buf[i]))
break;
}
}
}
-static void nonblock(int fd)
-{
- fcntl(fd, F_SETFL, O_NONBLOCK | fcntl(fd, F_GETFL));
-}
-
static void alarm_handler(int sig ATTRIBUTE_UNUSED)
{
/* This is the escape hatch! Poor serial line users and the like
* arrive here when their connection is broken.
* We don't want to block here */
- nonblock(1);
- nonblock(2);
+ ndelay_on(1);
+ ndelay_on(2);
bb_info_msg("\r\nLogin timed out after %d seconds\r", TIMEOUT);
exit(EXIT_SUCCESS);
}
+int login_main(int argc, char **argv);
int login_main(int argc, char **argv)
{
+ enum {
+ LOGIN_OPT_f = (1<<0),
+ LOGIN_OPT_h = (1<<1),
+ LOGIN_OPT_p = (1<<2),
+ };
char fromhost[512];
char username[USERNAME_SIZE];
const char *tmp;
int amroot;
- int flag;
+ unsigned opt;
int count = 0;
struct passwd *pw;
- int opt_preserve = 0;
- int opt_fflag = 0;
- char *opt_host = 0;
-#ifdef CONFIG_SELINUX
- security_context_t user_sid = NULL;
-#endif
+ char *opt_host = NULL;
+ char *opt_user = NULL;
+ char full_tty[TTYNAME_SIZE];
+ USE_SELINUX(security_context_t user_sid = NULL;)
+ USE_FEATURE_UTMP(struct utmp utent;)
+ short_tty = full_tty;
username[0] = '\0';
amroot = (getuid() == 0);
signal(SIGALRM, alarm_handler);
alarm(TIMEOUT);
- while ((flag = getopt(argc, argv, "f:h:p")) != EOF) {
- switch (flag) {
- case 'p':
- opt_preserve = 1;
- break;
- case 'f':
- /*
- * username must be a separate token
- * (-f root, *NOT* -froot). --marekm
- */
- if (optarg != argv[optind-1])
- bb_show_usage();
-
- if (!amroot) /* Auth bypass only if real UID is zero */
- bb_error_msg_and_die("-f is for root only");
-
- safe_strncpy(username, optarg, sizeof(username));
- opt_fflag = 1;
- break;
- case 'h':
- opt_host = optarg;
- break;
- default:
- bb_show_usage();
- }
+ opt = getopt32(argc, argv, "f:h:p", &opt_user, &opt_host);
+ if (opt & LOGIN_OPT_f) {
+ if (!amroot)
+ bb_error_msg_and_die("-f is for root only");
+ safe_strncpy(username, opt_user, sizeof(username));
}
- if (optind < argc) /* user from command line (getty) */
+ if (optind < argc) /* user from command line (getty) */
safe_strncpy(username, argv[optind], sizeof(username));
/* Let's find out and memorize our tty */
short_tty = full_tty + 5;
}
- read_or_build_utent(!amroot);
+ read_or_build_utent(&utent, !amroot);
if (opt_host) {
- if (ENABLE_FEATURE_UTMP)
+ USE_FEATURE_UTMP(
safe_strncpy(utent.ut_host, opt_host, sizeof(utent.ut_host));
- snprintf(fromhost, sizeof(fromhost)-1, " on `%.100s' from "
- "`%.200s'", short_tty, opt_host);
- }
- else
- snprintf(fromhost, sizeof(fromhost)-1, " on `%.100s'", short_tty);
+ )
+ snprintf(fromhost, sizeof(fromhost)-1, " on '%.100s' from "
+ "'%.200s'", short_tty, opt_host);
+ } else
+ snprintf(fromhost, sizeof(fromhost)-1, " on '%.100s'", short_tty);
bb_setpgrp;
- openlog(bb_applet_name, LOG_PID | LOG_CONS | LOG_NOWAIT, LOG_AUTH);
+ openlog(applet_name, LOG_PID | LOG_CONS | LOG_NOWAIT, LOG_AUTH);
while (1) {
if (!username[0])
if (pw->pw_passwd[0] == '!' || pw->pw_passwd[0] == '*')
goto auth_failed;
- if (opt_fflag)
+ if (opt & LOGIN_OPT_f)
break; /* -f USER: success without asking passwd */
if (pw->pw_uid == 0 && !check_securetty())
/* Don't check the password if password entry is empty (!) */
if (!pw->pw_passwd[0])
- break;
+ break;
/* authorization takes place here */
if (correct_password(pw))
- break;
+ break;
auth_failed:
- opt_fflag = 0;
+ opt &= ~LOGIN_OPT_f;
bb_do_delay(FAIL_DELAY);
puts("Login incorrect");
if (++count == 3) {
- syslog(LOG_WARNING, "invalid password for `%s'%s",
+ syslog(LOG_WARNING, "invalid password for '%s'%s",
username, fromhost);
return EXIT_FAILURE;
}
alarm(0);
die_if_nologin_and_non_root(pw->pw_uid == 0);
- write_utent(username);
+ write_utent(&utent, username);
#ifdef CONFIG_SELINUX
if (is_selinux_enabled()) {
security_context_t old_tty_sid, new_tty_sid;
if (get_default_context(username, NULL, &user_sid)) {
- bb_error_msg_and_die("unable to get SID for %s",
+ bb_error_msg_and_die("cannot get SID for %s",
username);
}
if (getfilecon(full_tty, &old_tty_sid) < 0) {
- bb_perror_msg_and_die("getfilecon(%.100s) failed",
+ bb_perror_msg_and_die("getfilecon(%s) failed",
full_tty);
}
if (security_compute_relabel(user_sid, old_tty_sid,
SECCLASS_CHR_FILE, &new_tty_sid) != 0) {
- bb_perror_msg_and_die("security_change_sid(%.100s) failed",
+ bb_perror_msg_and_die("security_change_sid(%s) failed",
full_tty);
}
if (setfilecon(full_tty, new_tty_sid) != 0) {
- bb_perror_msg_and_die("chsid(%.100s, %s) failed",
+ bb_perror_msg_and_die("chsid(%s, %s) failed",
full_tty, new_tty_sid);
}
}
fchmod(0, 0600);
if (ENABLE_LOGIN_SCRIPTS) {
- char *script = getenv("LOGIN_PRE_SUID_SCRIPT");
- if (script) {
- char *t_argv[2] = { script, NULL };
- switch (fork()) {
- case -1: break;
- case 0: /* child */
- xchdir("/");
- setenv("LOGIN_TTY", full_tty, 1);
- setenv("LOGIN_USER", pw->pw_name, 1);
- setenv("LOGIN_UID", utoa(pw->pw_uid), 1);
- setenv("LOGIN_GID", utoa(pw->pw_gid), 1);
- setenv("LOGIN_SHELL", pw->pw_shell, 1);
- execvp(script, t_argv);
- exit(1);
- default: /* parent */
- wait(NULL);
- }
+ char *t_argv[2];
+
+ t_argv[0] = getenv("LOGIN_PRE_SUID_SCRIPT");
+ if (t_argv[0]) {
+ t_argv[1] = NULL;
+ setenv("LOGIN_TTY", full_tty, 1);
+ setenv("LOGIN_USER", pw->pw_name, 1);
+ setenv("LOGIN_UID", utoa(pw->pw_uid), 1);
+ setenv("LOGIN_GID", utoa(pw->pw_gid), 1);
+ setenv("LOGIN_SHELL", pw->pw_shell, 1);
+ xspawn(argv); /* NOMMU-friendly */
+ unsetenv("LOGIN_TTY");
+ unsetenv("LOGIN_USER");
+ unsetenv("LOGIN_UID");
+ unsetenv("LOGIN_GID");
+ unsetenv("LOGIN_SHELL");
+ wait(NULL);
}
}
tmp = pw->pw_shell;
if (!tmp || !*tmp)
tmp = DEFAULT_SHELL;
- setup_environment(tmp, 1, !opt_preserve, pw);
+ setup_environment(tmp, 1, !(opt & LOGIN_OPT_p), pw);
motd();
- signal(SIGALRM, SIG_DFL); /* default alarm signal */
if (pw->pw_uid == 0)
syslog(LOG_INFO, "root login%s", fromhost);
* but let's play the game for now */
set_current_security_context(user_sid);
#endif
- run_shell(tmp, 1, 0, 0); /* exec the shell finally. */
+
+ // util-linux login also does:
+ // /* start new session */
+ // setsid();
+ // /* TIOCSCTTY: steal tty from other process group */
+ // if (ioctl(0, TIOCSCTTY, 1)) error_msg...
+
+ /* set signals to defaults */
+ signal(SIGALRM, SIG_DFL);
+ /* Is this correct? This way user can ctrl-c out of /etc/profile,
+ * potentially creating security breach (tested with bash 3.0).
+ * But without this, bash 3.0 will not enable ctrl-c either.
+ * Maybe bash is buggy?
+ * Need to find out what standards say about /bin/login -
+ * should it leave SIGINT etc enabled or disabled? */
+ signal(SIGINT, SIG_DFL);
+
+ run_shell(tmp, 1, 0, 0); /* exec the shell finally */
return EXIT_FAILURE;
}
projects / oweals / busybox.git / blobdiff