*/
#include "libbb.h"
+#include <syslog.h>
#include <utmp.h>
#include <sys/resource.h>
-#include <syslog.h>
#if ENABLE_SELINUX
#include <selinux/selinux.h> /* for is_selinux_enabled() */
* remotely meaningful by skipping "tty"... */
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);
+ utptr->ut_tv.tv_sec = time(NULL);
}
if (!picky) /* root login */
memset(utptr->ut_host, 0, sizeof(utptr->ut_host));
{
utptr->ut_type = USER_PROCESS;
strncpy(utptr->ut_user, username, sizeof(utptr->ut_user));
- utptr->ut_time = time(NULL);
+ utptr->ut_tv.tv_sec = time(NULL);
/* other fields already filled in by read_or_build_utent above */
setutent();
pututline(utptr);
#endif /* !ENABLE_FEATURE_UTMP */
#if ENABLE_FEATURE_NOLOGIN
-static void die_if_nologin_and_non_root(int amroot)
+static void die_if_nologin(void)
{
FILE *fp;
int c;
if (access("/etc/nologin", F_OK))
return;
- fp = fopen("/etc/nologin", "r");
+ fp = fopen_for_read("/etc/nologin");
if (fp) {
while ((c = getc(fp)) != EOF)
- putchar((c=='\n') ? '\r' : c);
+ bb_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");
+ exit(EXIT_FAILURE);
}
#else
-static ALWAYS_INLINE void die_if_nologin_and_non_root(int amroot) {}
+static ALWAYS_INLINE void die_if_nologin(void) {}
#endif
#if ENABLE_FEATURE_SECURETTY && !ENABLE_PAM
static int check_securetty(void)
{
- FILE *fp;
- int i;
- char buf[256];
-
- fp = fopen("/etc/securetty", "r");
- 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] || (buf[0] == '#'))
- continue;
- if (strcmp(buf, short_tty) == 0) {
- fclose(fp);
- return 1;
- }
+ 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;
}
- fclose(fp);
- return 0;
+ 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(void) { return 1; }
/* skip whitespace */
do {
c = getchar();
- if (c == EOF) exit(1);
+ if (c == EOF) exit(EXIT_FAILURE);
if (c == '\n') {
- if (!--cntdown) exit(1);
+ if (!--cntdown) exit(EXIT_FAILURE);
goto prompt;
}
} while (isspace(c));
*buf++ = c;
if (!fgets(buf, size_buf-2, stdin))
- exit(1);
+ exit(EXIT_FAILURE);
if (!strchr(buf, '\n'))
- exit(1);
+ exit(EXIT_FAILURE);
while (isgraph(*buf)) buf++;
*buf = '\0';
}
int fd;
fd = open(bb_path_motd_file, O_RDONLY);
- if (fd) {
+ if (fd >= 0) {
fflush(stdout);
bb_copyfd_eof(fd, STDOUT_FILENO);
close(fd);
}
}
-static void alarm_handler(int sig ATTRIBUTE_UNUSED)
+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(1);
- ndelay_on(2);
printf("\r\nLogin timed out after %d seconds\r\n", TIMEOUT);
- exit(EXIT_SUCCESS);
+ fflush(stdout);
+ /* unix API is brain damaged regarding O_NONBLOCK,
+ * we should undo it, or else we can affect other processes */
+ ndelay_off(1);
+ _exit(EXIT_SUCCESS);
}
-int login_main(int argc, char **argv);
-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)
{
enum {
LOGIN_OPT_f = (1<<0),
unsigned opt;
int count = 0;
struct passwd *pw;
- char *opt_host = NULL;
- char *opt_user = NULL;
+ char *opt_host = opt_host; /* for compiler */
+ char *opt_user = opt_user; /* for compiler */
char full_tty[TTYNAME_SIZE];
USE_SELINUX(security_context_t user_sid = NULL;)
USE_FEATURE_UTMP(struct utmp utent;)
- USE_PAM(pam_handle_t *pamh;)
- USE_PAM(int pamret;)
- USE_PAM(const char *failed_msg;)
+#if ENABLE_PAM
+ int pamret;
+ pam_handle_t *pamh;
+ const char *pamuser;
+ const char *failed_msg;
+ struct passwd pwdstruct;
+ char pwdbuf[256];
+#endif
short_tty = full_tty;
username[0] = '\0';
- amroot = (getuid() == 0);
signal(SIGALRM, alarm_handler);
alarm(TIMEOUT);
+ /* More of suid paranoia if called by non-root */
+ amroot = !sanitize_env_if_suid(); /* Clear dangerous stuff, set PATH */
+
/* 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.
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) */
- safe_strncpy(username, argv[optind], sizeof(username));
+ argv += optind;
+ if (argv[0]) /* user from command line (getty) */
+ safe_strncpy(username, argv[0], sizeof(username));
/* Let's find out and memorize our tty */
if (!isatty(0) || !isatty(1) || !isatty(2))
read_or_build_utent(&utent, !amroot);
- if (opt_host) {
+ if (opt & LOGIN_OPT_h) {
USE_FEATURE_UTMP(
safe_strncpy(utent.ut_host, opt_host, sizeof(utent.ut_host));
)
openlog(applet_name, LOG_PID | LOG_CONS | LOG_NOWAIT, LOG_AUTH);
while (1) {
+ /* flush away any type-ahead (as getty does) */
+ ioctl(0, TCFLSH, TCIFLUSH);
+
if (!username[0])
get_username_or_die(username, sizeof(username));
#if ENABLE_PAM
pamret = pam_start("login", username, &conv, &pamh);
if (pamret != PAM_SUCCESS) {
- failed_msg = "pam_start";
+ 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 = "pam_set_item(TTY)";
+ failed_msg = "set_item(TTY)";
goto pam_auth_failed;
}
pamret = pam_authenticate(pamh, 0);
if (pamret != PAM_SUCCESS) {
- failed_msg = "pam_authenticate";
+ failed_msg = "authenticate";
goto pam_auth_failed;
/* TODO: or just "goto auth_failed"
* since user seems to enter wrong password
/* check that the account is healthy */
pamret = pam_acct_mgmt(pamh, 0);
if (pamret != PAM_SUCCESS) {
- failed_msg = "account setup";
+ failed_msg = "acct_mgmt";
goto pam_auth_failed;
}
/* read user back */
- {
- const char *pamuser;
- /* 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 = "pam_get_item(USER)";
- goto pam_auth_failed;
- }
- safe_strncpy(username, pamuser, sizeof(username));
+ 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 we get here, the user was authenticated, and is
- * granted access. */
- pw = getpwnam(username);
- if (pw)
- break;
- goto 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:
- bb_error_msg("%s failed: %s (%d)", failed_msg, pam_strerror(pamh, pamret), pamret);
+ bb_error_msg("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);
}
alarm(0);
- die_if_nologin_and_non_root(pw->pw_uid == 0);
+ if (!amroot)
+ die_if_nologin();
write_utent(&utent, username);
fchown(0, pw->pw_uid, pw->pw_gid);
fchmod(0, 0600);
- if (ENABLE_LOGIN_SCRIPTS) {
+ /* We trust environment only if we run by root */
+ if (ENABLE_LOGIN_SCRIPTS && amroot) {
char *t_argv[2];
t_argv[0] = getenv("LOGIN_PRE_SUID_SCRIPT");
xsetenv("LOGIN_UID", utoa(pw->pw_uid));
xsetenv("LOGIN_GID", utoa(pw->pw_gid));
xsetenv("LOGIN_SHELL", pw->pw_shell);
- xspawn(t_argv); /* NOMMU-friendly */
- /* All variables are unset by setup_environment */
- wait(NULL);
+ spawn_and_wait(t_argv); /* NOMMU-friendly */
+ unsetenv("LOGIN_TTY" );
+ unsetenv("LOGIN_USER" );
+ unsetenv("LOGIN_UID" );
+ unsetenv("LOGIN_GID" );
+ unsetenv("LOGIN_SHELL");
}
}
tmp = pw->pw_shell;
if (!tmp || !*tmp)
tmp = DEFAULT_SHELL;
- /* setup_environment params: shell, loginshell, changeenv, pw */
- setup_environment(tmp, 1, !(opt & LOGIN_OPT_p), pw);
- /* FIXME: login shell = 1 -> 3rd parameter is ignored! */
+ /* setup_environment params: shell, clear_env, change_env, pw */
+ setup_environment(tmp, !(opt & LOGIN_OPT_p), 1, pw);
motd();
projects / oweals / busybox.git / blobdiff