/* vi: set sw=4 ts=4: */
/*
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
-#include <fcntl.h>
-#include <signal.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
+//usage:#define login_trivial_usage
+//usage: "[-p] [-h HOST] [[-f] USER]"
+//usage:#define login_full_usage "\n\n"
+//usage: "Begin a new session on the system\n"
+//usage: "\n -f Don't authenticate (user already authenticated)"
+//usage: "\n -h Name of the remote host"
+//usage: "\n -p Preserve environment"
+
+#include "libbb.h"
#include <syslog.h>
-#include <termios.h>
-#include <unistd.h>
-#include <utmp.h>
#include <sys/resource.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <sys/wait.h>
-#include <ctype.h>
-#include <time.h>
-
-#include "busybox.h"
-#ifdef CONFIG_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 */
-#include <errno.h>
+
+#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 */
#endif
-#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;
+#if ENABLE_PAM
+/* PAM may include <locale.h>. We may need to undefine bbox's stub define: */
+# undef setlocale
+/* For some obscure reason, PAM is not in pam/xxx, but in security/xxx.
+ * Apparently they like to confuse people. */
+# include <security/pam_appl.h>
+# include <security/pam_misc.h>
+static const struct pam_conv conv = {
+ misc_conv,
+ NULL
+};
#endif
enum {
TIMEOUT = 60,
EMPTY_USERNAME_COUNT = 10,
- USERNAME_SIZE = 32,
+ /* Some users found 32 chars limit to be too low: */
+ USERNAME_SIZE = 64,
+ TTYNAME_SIZE = 32,
};
-static int check_nologin(int amroot);
+struct globals {
+ struct termios tty_attrs;
+} FIX_ALIASING;
+#define G (*(struct globals*)&bb_common_bufsiz1)
+#define INIT_G() do { } while (0)
-#if defined CONFIG_FEATURE_SECURETTY
-static int check_tty(const char *tty);
+#if ENABLE_FEATURE_NOLOGIN
+static void die_if_nologin(void)
+{
+ FILE *fp;
+ int c;
+ int empty = 1;
+
+ fp = fopen_for_read("/etc/nologin");
+ if (!fp) /* assuming it does not exist */
+ return;
+
+ while ((c = getc(fp)) != EOF) {
+ if (c == '\n')
+ bb_putchar('\r');
+ bb_putchar(c);
+ empty = 0;
+ }
+ if (empty)
+ puts("\r\nSystem closed for routine maintenance\r");
+
+ fclose(fp);
+ fflush_all();
+ /* Users say that they do need this prior to exit: */
+ tcdrain(STDOUT_FILENO);
+ exit(EXIT_FAILURE);
+}
#else
-static inline int check_tty(const char *tty) { return 1; }
+# define die_if_nologin() ((void)0)
+#endif
+#if ENABLE_FEATURE_SECURETTY && !ENABLE_PAM
+static int check_securetty(const char *short_tty)
+{
+ char *buf = (char*)"/etc/securetty"; /* any non-NULL is ok */
+ parser_t *parser = config_open2("/etc/securetty", fopen_for_read);
+ while (config_read(parser, &buf, 1, 1, "# \t", PARSE_NORMAL)) {
+ if (strcmp(buf, short_tty) == 0)
+ break;
+ buf = NULL;
+ }
+ config_close(parser);
+ /* buf != NULL here if config file was not found, empty
+ * or line was found which equals short_tty */
+ return buf != NULL;
+}
+#else
+static ALWAYS_INLINE int check_securetty(const char *short_tty UNUSED_PARAM) { return 1; }
#endif
-static int is_my_tty(const char *tty);
-static int login_prompt(char *buf_name);
-static void motd(void);
+#if ENABLE_SELINUX
+static void initselinux(char *username, char *full_tty,
+ security_context_t *user_sid)
+{
+ security_context_t old_tty_sid, new_tty_sid;
+ if (!is_selinux_enabled())
+ return;
-static void alarm_handler(int sig ATTRIBUTE_UNUSED)
+ if (get_default_context(username, NULL, user_sid)) {
+ bb_error_msg_and_die("can't get SID for %s", username);
+ }
+ if (getfilecon(full_tty, &old_tty_sid) < 0) {
+ 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(%s) failed", full_tty);
+ }
+ if (setfilecon(full_tty, new_tty_sid) != 0) {
+ bb_perror_msg_and_die("chsid(%s, %s) failed", full_tty, new_tty_sid);
+ }
+}
+#endif
+
+#if ENABLE_LOGIN_SCRIPTS
+static void run_login_script(struct passwd *pw, char *full_tty)
{
- fprintf(stderr, "\nLogin timed out after %d seconds.\n", TIMEOUT);
- exit(EXIT_SUCCESS);
+ char *t_argv[2];
+
+ t_argv[0] = getenv("LOGIN_PRE_SUID_SCRIPT");
+ if (t_argv[0]) {
+ t_argv[1] = NULL;
+ xsetenv("LOGIN_TTY", full_tty);
+ xsetenv("LOGIN_USER", pw->pw_name);
+ xsetenv("LOGIN_UID", utoa(pw->pw_uid));
+ xsetenv("LOGIN_GID", utoa(pw->pw_gid));
+ xsetenv("LOGIN_SHELL", pw->pw_shell);
+ spawn_and_wait(t_argv); /* NOMMU-friendly */
+ unsetenv("LOGIN_TTY");
+ unsetenv("LOGIN_USER");
+ unsetenv("LOGIN_UID");
+ unsetenv("LOGIN_GID");
+ unsetenv("LOGIN_SHELL");
+ }
+}
+#else
+void run_login_script(struct passwd *pw, char *full_tty);
+#endif
+
+#if ENABLE_LOGIN_SESSION_AS_CHILD && ENABLE_PAM
+static void login_pam_end(pam_handle_t *pamh)
+{
+ int pamret;
+
+ pamret = pam_setcred(pamh, PAM_DELETE_CRED);
+ if (pamret != PAM_SUCCESS) {
+ bb_error_msg("pam_%s failed: %s (%d)", "setcred",
+ pam_strerror(pamh, pamret), pamret);
+ }
+ pamret = pam_close_session(pamh, 0);
+ if (pamret != PAM_SUCCESS) {
+ bb_error_msg("pam_%s failed: %s (%d)", "close_session",
+ pam_strerror(pamh, pamret), pamret);
+ }
+ pamret = pam_end(pamh, pamret);
+ if (pamret != PAM_SUCCESS) {
+ bb_error_msg("pam_%s failed: %s (%d)", "end",
+ pam_strerror(pamh, pamret), pamret);
+ }
+}
+#endif /* ENABLE_PAM */
+
+static void get_username_or_die(char *buf, int size_buf)
+{
+ int c, cntdown;
+
+ cntdown = EMPTY_USERNAME_COUNT;
+ prompt:
+ print_login_prompt();
+ /* skip whitespace */
+ do {
+ c = getchar();
+ if (c == EOF)
+ exit(EXIT_FAILURE);
+ if (c == '\n') {
+ if (!--cntdown)
+ exit(EXIT_FAILURE);
+ goto prompt;
+ }
+ } while (isspace(c)); /* maybe isblank? */
+
+ *buf++ = c;
+ if (!fgets(buf, size_buf-2, stdin))
+ exit(EXIT_FAILURE);
+ if (!strchr(buf, '\n'))
+ exit(EXIT_FAILURE);
+ while ((unsigned char)*buf > ' ')
+ buf++;
+ *buf = '\0';
+}
+
+static void motd(void)
+{
+ int fd;
+
+ fd = open(bb_path_motd_file, O_RDONLY);
+ if (fd >= 0) {
+ fflush_all();
+ bb_copyfd_eof(fd, STDOUT_FILENO);
+ close(fd);
+ }
}
+static void alarm_handler(int sig UNUSED_PARAM)
+{
+ /* 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 */
+ ndelay_on(STDOUT_FILENO);
+ /* Test for correct attr restoring:
+ * run "getty 0 -" from a shell, enter bogus username, stop at
+ * password prompt, let it time out. Without the tcsetattr below,
+ * when you are back at shell prompt, echo will be still off.
+ */
+ tcsetattr_stdin_TCSANOW(&G.tty_attrs);
+ printf("\r\nLogin timed out after %u seconds\r\n", TIMEOUT);
+ fflush_all();
+ /* unix API is brain damaged regarding O_NONBLOCK,
+ * we should undo it, or else we can affect other processes */
+ ndelay_off(STDOUT_FILENO);
+ _exit(EXIT_SUCCESS);
+}
-int login_main(int argc, char **argv)
+int login_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int login_main(int argc UNUSED_PARAM, char **argv)
{
- char tty[BUFSIZ];
- char full_tty[200];
- char fromhost[512];
+ enum {
+ LOGIN_OPT_f = (1<<0),
+ LOGIN_OPT_h = (1<<1),
+ LOGIN_OPT_p = (1<<2),
+ };
+ char *fromhost;
char username[USERNAME_SIZE];
- const char *tmp;
- int amroot;
- int flag;
- int failed;
+ int run_by_root;
+ unsigned opt;
int count = 0;
- struct passwd *pw, pw_copy;
-#ifdef CONFIG_WHEEL_GROUP
- struct group *grp;
+ struct passwd *pw;
+ char *opt_host = NULL;
+ char *opt_user = opt_user; /* for compiler */
+ char *full_tty;
+ char *short_tty;
+ IF_SELINUX(security_context_t user_sid = NULL;)
+#if ENABLE_PAM
+ int pamret;
+ pam_handle_t *pamh;
+ const char *pamuser;
+ const char *failed_msg;
+ struct passwd pwdstruct;
+ char pwdbuf[256];
+ char **pamenv;
#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;
+#if ENABLE_LOGIN_SESSION_AS_CHILD
+ pid_t child_pid;
#endif
- username[0] = '\0';
- amroot = (getuid() == 0);
- signal(SIGALRM, alarm_handler);
- alarm(TIMEOUT);
- alarmstarted = 1;
+ INIT_G();
- 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 permission denied");
-
- safe_strncpy(username, optarg, USERNAME_SIZE);
- opt_fflag = 1;
- break;
- case 'h':
- opt_host = optarg;
- break;
- default:
- bb_show_usage();
- }
- }
+ /* More of suid paranoia if called by non-root: */
+ /* Clear dangerous stuff, set PATH */
+ run_by_root = !sanitize_env_if_suid();
- if (optind < argc) /* user from command line (getty) */
- safe_strncpy(username, argv[optind], USERNAME_SIZE);
+ /* Mandatory paranoia for suid applet:
+ * ensure that fd# 0,1,2 are opened (at least to /dev/null)
+ * and any extra open fd's are closed.
+ * (The name of the function is misleading. Not daemonizing here.) */
+ bb_daemonize_or_rexec(DAEMON_ONLY_SANITIZE | DAEMON_CLOSE_EXTRA_FDS, NULL);
- if (!isatty(0) || !isatty(1) || !isatty(2))
- return EXIT_FAILURE; /* Must be a terminal */
+ username[0] = '\0';
+ opt = getopt32(argv, "f:h:p", &opt_user, &opt_host);
+ if (opt & LOGIN_OPT_f) {
+ if (!run_by_root)
+ bb_error_msg_and_die("-f is for root only");
+ safe_strncpy(username, opt_user, sizeof(username));
+ }
+ argv += optind;
+ if (argv[0]) /* user from command line (getty) */
+ safe_strncpy(username, argv[0], sizeof(username));
+
+ /* Save tty attributes - and by doing it, check that it's indeed a tty */
+ if (tcgetattr(STDIN_FILENO, &G.tty_attrs) < 0
+ || !isatty(STDOUT_FILENO)
+ /*|| !isatty(STDERR_FILENO) - no, guess some people might want to redirect this */
+ ) {
+ return EXIT_FAILURE; /* Must be a terminal */
+ }
-#ifdef CONFIG_FEATURE_UTMP
- checkutmp(!amroot);
-#endif
+ /* We install timeout handler only _after_ we saved G.tty_attrs */
+ signal(SIGALRM, alarm_handler);
+ alarm(TIMEOUT);
- 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));
-
-#ifdef CONFIG_FEATURE_UTMP
- if (amroot)
- memset(utent.ut_host, 0, sizeof(utent.ut_host));
-#endif
+ /* Find out and memorize our tty name */
+ full_tty = xmalloc_ttyname(STDIN_FILENO);
+ if (!full_tty)
+ full_tty = xstrdup("UNKNOWN");
+ short_tty = skip_dev_pfx(full_tty);
if (opt_host) {
-#ifdef CONFIG_FEATURE_UTMP
- safe_strncpy(utent.ut_host, opt_host, sizeof(utent.ut_host));
-#endif
- snprintf(fromhost, sizeof(fromhost)-1, " on `%.100s' from `%.200s'", tty, opt_host);
+ fromhost = xasprintf(" on '%s' from '%s'", short_tty, opt_host);
+ } else {
+ fromhost = xasprintf(" on '%s'", short_tty);
}
- else
- snprintf(fromhost, sizeof(fromhost)-1, " on `%.100s'", tty);
- bb_setpgrp;
+ /* Was breaking "login <username>" from shell command line: */
+ /*bb_setpgrp();*/
- openlog("login", LOG_PID | LOG_CONS | LOG_NOWAIT, LOG_AUTH);
+ openlog(applet_name, LOG_PID | LOG_CONS, LOG_AUTH);
while (1) {
- failed = 0;
+ /* flush away any type-ahead (as getty does) */
+ tcflush(0, TCIFLUSH);
if (!username[0])
- if (!login_prompt(username))
- return EXIT_FAILURE;
+ get_username_or_die(username, sizeof(username));
- if (!alarmstarted && (TIMEOUT > 0)) {
- alarm(TIMEOUT);
- alarmstarted = 1;
+#if ENABLE_PAM
+ pamret = pam_start("login", username, &conv, &pamh);
+ if (pamret != PAM_SUCCESS) {
+ failed_msg = "start";
+ goto pam_auth_failed;
}
-
+ /* set TTY (so things like securetty work) */
+ pamret = pam_set_item(pamh, PAM_TTY, short_tty);
+ if (pamret != PAM_SUCCESS) {
+ failed_msg = "set_item(TTY)";
+ goto pam_auth_failed;
+ }
+ /* set RHOST */
+ if (opt_host) {
+ pamret = pam_set_item(pamh, PAM_RHOST, opt_host);
+ if (pamret != PAM_SUCCESS) {
+ failed_msg = "set_item(RHOST)";
+ goto pam_auth_failed;
+ }
+ }
+ if (!(opt & LOGIN_OPT_f)) {
+ pamret = pam_authenticate(pamh, 0);
+ if (pamret != PAM_SUCCESS) {
+ failed_msg = "authenticate";
+ goto pam_auth_failed;
+ /* TODO: or just "goto auth_failed"
+ * since user seems to enter wrong password
+ * (in this case pamret == 7)
+ */
+ }
+ }
+ /* check that the account is healthy */
+ pamret = pam_acct_mgmt(pamh, 0);
+ if (pamret != PAM_SUCCESS) {
+ failed_msg = "acct_mgmt";
+ goto pam_auth_failed;
+ }
+ /* read user back */
+ pamuser = NULL;
+ /* gcc: "dereferencing type-punned pointer breaks aliasing rules..."
+ * thus we cast to (void*) */
+ if (pam_get_item(pamh, PAM_USER, (void*)&pamuser) != PAM_SUCCESS) {
+ failed_msg = "get_item(USER)";
+ goto pam_auth_failed;
+ }
+ if (!pamuser || !pamuser[0])
+ goto auth_failed;
+ safe_strncpy(username, pamuser, sizeof(username));
+ /* Don't use "pw = getpwnam(username);",
+ * PAM is said to be capable of destroying static storage
+ * used by getpwnam(). We are using safe(r) function */
+ pw = NULL;
+ getpwnam_r(username, &pwdstruct, pwdbuf, sizeof(pwdbuf), &pw);
+ if (!pw)
+ goto auth_failed;
+ pamret = pam_open_session(pamh, 0);
+ if (pamret != PAM_SUCCESS) {
+ failed_msg = "open_session";
+ goto pam_auth_failed;
+ }
+ pamret = pam_setcred(pamh, PAM_ESTABLISH_CRED);
+ if (pamret != PAM_SUCCESS) {
+ failed_msg = "setcred";
+ goto pam_auth_failed;
+ }
+ break; /* success, continue login process */
+
+ pam_auth_failed:
+ /* syslog, because we don't want potential attacker
+ * to know _why_ login failed */
+ syslog(LOG_WARNING, "pam_%s call failed: %s (%d)", failed_msg,
+ pam_strerror(pamh, pamret), pamret);
+ safe_strncpy(username, "UNKNOWN", sizeof(username));
+#else /* not PAM */
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;
+ strcpy(username, "UNKNOWN");
+ goto fake_it;
+ }
- 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 & LOGIN_OPT_f)
+ 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(short_tty))
+ goto auth_failed;
/* Don't check the password if password entry is empty (!) */
if (!pw->pw_passwd[0])
- goto auth_ok;
-
- /* authorization takes place here */
+ break;
+ fake_it:
+ /* Password reading and authorization takes place here.
+ * Note that reads (in no-echo mode) trash tty attributes.
+ * If we get interrupted by SIGALRM, we need to restore attrs.
+ */
if (correct_password(pw))
- goto auth_ok;
-
- failed = 1;
-
-auth_ok:
- if (!failed)
break;
-
- bb_do_delay(FAIL_DELAY);
+#endif /* ENABLE_PAM */
+ auth_failed:
+ opt &= ~LOGIN_OPT_f;
+ bb_do_delay(LOGIN_FAIL_DELAY);
+ /* TODO: doesn't sound like correct English phrase to me */
puts("Login incorrect");
- username[0] = 0;
if (++count == 3) {
- syslog(LOG_WARNING, "invalid password for `%s'%s'\n", pw->pw_name, fromhost);
- return EXIT_FAILURE;
- }
- }
-
- alarm(0);
- if (check_nologin(pw->pw_uid == 0))
- return EXIT_FAILURE;
+ syslog(LOG_WARNING, "invalid password for '%s'%s",
+ username, fromhost);
-#ifdef CONFIG_FEATURE_UTMP
- setutmp(username, tty);
-#endif
-
- if (*tty != '/')
- snprintf(full_tty, sizeof(full_tty)-1, "/dev/%s", tty);
- else
- safe_strncpy(full_tty, tty, sizeof(full_tty)-1);
-
-#ifdef CONFIG_SELINUX
- if (is_selinux_enabled()) {
- security_context_t old_tty_sid, new_tty_sid;
+ if (ENABLE_FEATURE_CLEAN_UP)
+ free(fromhost);
- if (get_default_context(username, NULL, &user_sid)) {
- fprintf(stderr, "Unable to get SID for %s\n", username);
- exit(1);
- }
- if (getfilecon(full_tty, &old_tty_sid) < 0) {
- fprintf(stderr, "getfilecon(%.100s) failed: "
- "%.100s\n", full_tty, strerror(errno));
- return EXIT_FAILURE;
- }
- if (security_compute_relabel(user_sid, old_tty_sid, SECCLASS_CHR_FILE,
- &new_tty_sid) != 0) {
- fprintf(stderr, "security_change_sid(%.100s) failed: "
- "%.100s\n", full_tty, strerror(errno));
return EXIT_FAILURE;
}
- if (setfilecon(full_tty, new_tty_sid) != 0) {
- fprintf(stderr, "chsid(%.100s, %s) failed: "
- "%.100s\n", full_tty, new_tty_sid, strerror(errno));
- return EXIT_FAILURE;
- }
- }
-#endif
- if (!is_my_tty(full_tty))
- syslog(LOG_ERR, "unable to determine TTY name, got %s\n", full_tty);
-
- /* Try these, but don't complain if they fail
- * (for example when the root fs is read only) */
- chown(full_tty, pw->pw_uid, pw->pw_gid);
- chmod(full_tty, 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);
- }
- }
- }
-
- change_identity(pw);
- tmp = pw->pw_shell;
- if (!tmp || !*tmp)
- tmp = DEFAULT_SHELL;
- setup_environment(tmp, 1, !opt_preserve, pw);
-
- motd();
- signal(SIGALRM, SIG_DFL); /* default alarm signal */
-
- if (pw->pw_uid == 0)
- syslog(LOG_INFO, "root login %s\n", fromhost);
-#ifdef CONFIG_SELINUX
- /* well, a simple setexeccon() here would do the job as well,
- * 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. */
-
- return EXIT_FAILURE;
-}
-
-
-static int login_prompt(char *buf_name)
-{
- 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;
-}
-
-
-static int check_nologin(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);
-
- fflush(stdout);
- fclose(fp);
- } else {
- puts("\r\nSystem closed for routine maintenance.\r");
- }
- if (!amroot)
- return 1;
-
- puts("\r\n[Disconnect bypassed -- root login allowed.]\r");
- }
- return 0;
-}
-
-#ifdef CONFIG_FEATURE_SECURETTY
-
-static int check_tty(const char *tty)
-{
- 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;
+ username[0] = '\0';
+ } /* while (1) */
- if (strcmp(buf, tty)== 0) {
- fclose(fp);
- return 1;
- }
+ alarm(0);
+ /* We can ignore /etc/nologin if we are logging in as root,
+ * it doesn't matter whether we are run by root or not */
+ if (pw->pw_uid != 0)
+ die_if_nologin();
+
+#if ENABLE_LOGIN_SESSION_AS_CHILD
+ child_pid = vfork();
+ if (child_pid != 0) {
+ if (child_pid < 0)
+ bb_perror_msg("vfork");
+ else {
+ if (safe_waitpid(child_pid, NULL, 0) == -1)
+ bb_perror_msg("waitpid");
+ update_utmp(child_pid, DEAD_PROCESS, NULL, NULL, NULL);
}
- fclose(fp);
+ IF_PAM(login_pam_end(pamh);)
return 0;
}
- /* A missing securetty file is not an error. */
- return 1;
-}
-
#endif
-/* returns 1 if true */
-static int is_my_tty(const char *tty)
-{
- struct stat by_name, by_fd;
+ IF_SELINUX(initselinux(username, full_tty, &user_sid);)
- if (stat(tty, &by_name) || fstat(0, &by_fd))
- return 0;
-
- if (by_name.st_rdev != by_fd.st_rdev)
- return 0;
- else
- return 1;
-}
+ /* Try these, but don't complain if they fail.
+ * _f_chown is safe wrt race t=ttyname(0);...;chown(t); */
+ fchown(0, pw->pw_uid, pw->pw_gid);
+ fchmod(0, 0600);
+ update_utmp(getpid(), USER_PROCESS, short_tty, username, run_by_root ? opt_host : NULL);
-static void motd(void)
-{
- FILE *fp;
- int c;
+ /* We trust environment only if we run by root */
+ if (ENABLE_LOGIN_SCRIPTS && run_by_root)
+ run_login_script(pw, full_tty);
- fp = fopen(bb_path_motd_file, "r");
- if (fp) {
- while ((c = getc(fp)) != EOF)
- putchar(c);
- fclose(fp);
+ change_identity(pw);
+ setup_environment(pw->pw_shell,
+ (!(opt & LOGIN_OPT_p) * SETUP_ENV_CLEARENV) + SETUP_ENV_CHANGEENV,
+ pw);
+
+#if ENABLE_PAM
+ /* Modules such as pam_env will setup the PAM environment,
+ * which should be copied into the new environment. */
+ pamenv = pam_getenvlist(pamh);
+ if (pamenv) while (*pamenv) {
+ putenv(*pamenv);
+ pamenv++;
}
-}
-
-
-#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."
-
-/*
- * checkutmp - 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.
- * The utmp file is scanned for an entry with the same process
- * ID. If no entry exists the process exits with a message.
- *
- * The "picky" flag is for network and other logins that may
- * use special flags. It allows the pid checks to be overridden.
- * This means that getty should never invoke login with any
- * command line flags.
- */
-
-static void checkutmp(int picky)
-{
- char *line;
- struct utmp *ut;
- pid_t pid = getpid();
-
- setutent();
+#endif
- /* 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))
- break;
+ motd();
- /* 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;
- 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_user, "LOGIN", sizeof(utent.ut_user));
- t_tmp = (time_t)utent.ut_time;
- time(&t_tmp);
- }
-}
+ if (pw->pw_uid == 0)
+ syslog(LOG_INFO, "root login%s", fromhost);
-/*
- * setutmp - put a USER_PROCESS entry in the utmp file
- *
- * setutmp changes the type of the current utmp entry to
- * USER_PROCESS. the wtmp file will be updated as well.
- */
+ if (ENABLE_FEATURE_CLEAN_UP)
+ free(fromhost);
-static void setutmp(const char *name, const char *line ATTRIBUTE_UNUSED)
-{
- 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 */
- setutent();
- pututline(&utent);
- endutent();
-#ifdef CONFIG_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);
-#endif
+ /* well, a simple setexeccon() here would do the job as well,
+ * but let's play the game for now */
+ IF_SELINUX(set_current_security_context(user_sid);)
+
+ // util-linux login also does:
+ // /* start new session */
+ // setsid();
+ // /* TIOCSCTTY: steal tty from other process group */
+ // if (ioctl(0, TIOCSCTTY, 1)) error_msg...
+ // BBox login used to do this (see above):
+ // bb_setpgrp();
+ // If this stuff is really needed, add it and explain why!
+
+ /* Set signals to defaults */
+ /* Non-ignored signals revert to SIG_DFL on exec anyway */
+ /*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 we leave SIGINT etc enabled or disabled? */
+ signal(SIGINT, SIG_DFL);
+
+ /* Exec login shell with no additional parameters */
+ run_shell(pw->pw_shell, 1, NULL, NULL);
+
+ /* return EXIT_FAILURE; - not reached */
}
-#endif /* CONFIG_FEATURE_UTMP */