X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=loginutils%2Flogin.c;h=c1e0c769973dffcf518dbda4c34c7e5962997c11;hb=6e1b62b18ccc928cfa5ff62eb7030b3e5543c15d;hp=88123c0aabf9cfdcbdf05394f01ae9bd64996ba8;hpb=a3896511152cd5dcd64d2eb4aebcce65b29c6c0b;p=oweals%2Fbusybox.git diff --git a/loginutils/login.c b/loginutils/login.c index 88123c0aa..c1e0c7699 100644 --- a/loginutils/login.c +++ b/loginutils/login.c @@ -1,481 +1,505 @@ /* vi: set sw=4 ts=4: */ -#include -#include -#include -#include -#include -#include -#include -#include +/* + * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. + */ + +#include "libbb.h" #include #include -#include -#include -#include -#include -#include - -#include "busybox.h" -#ifdef CONFIG_SELINUX +#include + +#if ENABLE_SELINUX #include /* for is_selinux_enabled() */ #include /* for get_default_context() */ #include /* for security class definitions */ -#include #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 . 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 +#include +static const struct pam_conv conv = { + misc_conv, + NULL +}; #endif -// login defines -#define TIMEOUT 60 -#define EMPTY_USERNAME_COUNT 10 -#define USERNAME_SIZE 32 +enum { + TIMEOUT = 60, + EMPTY_USERNAME_COUNT = 10, + USERNAME_SIZE = 32, + TTYNAME_SIZE = 32, +}; + +static char* short_tty; +#if ENABLE_FEATURE_UTMP +/* vv Taken from tinylogin utmp.c vv */ +/* + * 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. + * 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 int check_nologin ( int amroot ); +static void read_or_build_utent(struct utmp *utptr, int picky) +{ + struct utmp *ut; + pid_t pid = getpid(); -#if defined CONFIG_FEATURE_SECURETTY -static int check_tty ( const char *tty ); + setutent(); -#else -static inline int check_tty ( const char *tty ) { return 1; } + /* 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; + + /* If there is one, just use it, otherwise create a new one. */ + if (ut) { + *utptr = *ut; + } else { + if (picky) + bb_error_msg_and_die("no utmp entry found"); + + 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(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(utptr->ut_host, 0, sizeof(utptr->ut_host)); +} + +/* + * write_utent - put a USER_PROCESS entry in the utmp file + * + * 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(struct utmp *utptr, const char *username) +{ + 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(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, utptr); +#endif +} +#else /* !ENABLE_FEATURE_UTMP */ +#define read_or_build_utent(utptr, picky) ((void)0) +#define write_utent(utptr, username) ((void)0) +#endif /* !ENABLE_FEATURE_UTMP */ +#if ENABLE_FEATURE_NOLOGIN +static void die_if_nologin_and_non_root(int amroot) +{ + FILE *fp; + int c; + + if (access("/etc/nologin", F_OK)) + return; + + fp = fopen("/etc/nologin", "r"); + if (fp) { + while ((c = getc(fp)) != EOF) + 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"); +} +#else +static ALWAYS_INLINE void die_if_nologin_and_non_root(int amroot) {} #endif -static int is_my_tty ( const char *tty ); -static int login_prompt ( char *buf_name ); -static void motd ( void ); +#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; + } + } + fclose(fp); + return 0; +} +#else +static ALWAYS_INLINE int check_securetty(void) { return 1; } +#endif +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(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 void alarm_handler ( int sig ATTRIBUTE_UNUSED) +static void motd(void) { - fprintf (stderr, "\nLogin timed out after %d seconds.\n", TIMEOUT ); - exit ( EXIT_SUCCESS ); + int fd; + + fd = open(bb_path_motd_file, O_RDONLY); + if (fd >= 0) { + fflush(stdout); + bb_copyfd_eof(fd, STDOUT_FILENO); + close(fd); + } } +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 */ + ndelay_on(1); + ndelay_on(2); + printf("\r\nLogin timed out after %d seconds\r\n", TIMEOUT); + /* unix API is brain damaged regarding O_NONBLOCK, + * we should undo it, or else we can affect other processes */ + ndelay_off(1); + ndelay_off(2); + exit(EXIT_SUCCESS); +} +int login_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int login_main(int argc, 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 count=0; - struct passwd *pw, pw_copy; -#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; + unsigned opt; + int count = 0; + struct passwd *pw; + 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;) +#if ENABLE_PAM + int pamret; + pam_handle_t *pamh; + const char *pamuser; + const char *failed_msg; + struct passwd pwdstruct; + char pwdbuf[256]; #endif - username[0]=0; - amroot = ( getuid ( ) == 0 ); - signal ( SIGALRM, alarm_handler ); - alarm ( TIMEOUT ); - alarmstarted = 1; - - 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( ); - } + short_tty = full_tty; + username[0] = '\0'; + amroot = (getuid() == 0); + signal(SIGALRM, alarm_handler); + alarm(TIMEOUT); + + /* 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); + /* More of suid paranoia if called by non-root */ + if (!amroot) { + /* Clear dangerous stuff, set PATH */ + sanitize_env_for_suid(); } - if (optind < argc) // user from command line (getty) - safe_strncpy(username, argv[optind], USERNAME_SIZE); + opt = getopt32(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) */ + safe_strncpy(username, argv[optind], sizeof(username)); - if ( !isatty ( 0 ) || !isatty ( 1 ) || !isatty ( 2 )) + /* Let's find out and memorize our tty */ + if (!isatty(0) || !isatty(1) || !isatty(2)) return EXIT_FAILURE; /* Must be a terminal */ + safe_strncpy(full_tty, "UNKNOWN", sizeof(full_tty)); + tmp = ttyname(0); + 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 - checkutmp ( !amroot ); -#endif + read_or_build_utent(&utent, !amroot); - 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 + if (opt_host) { + USE_FEATURE_UTMP( + safe_strncpy(utent.ut_host, opt_host, sizeof(utent.ut_host)); + ) + fromhost = xasprintf(" on '%s' from '%s'", short_tty, opt_host); + } else + fromhost = xasprintf(" on '%s'", short_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 ); - } - else - snprintf ( fromhost, sizeof( fromhost ) - 1, " on `%.100s'", tty ); + /* Was breaking "login " from shell command line: */ + /*bb_setpgrp();*/ - setpgrp(); + openlog(applet_name, LOG_PID | LOG_CONS | LOG_NOWAIT, LOG_AUTH); - openlog ( "login", LOG_PID | LOG_CONS | LOG_NOWAIT, LOG_AUTH ); + while (1) { - while ( 1 ) { - failed = 0; + /* flush away any type-ahead (as getty does) */ + (void) ioctl(0, TCFLSH, TCIFLUSH); - if ( !username[0] ) - if(!login_prompt ( username )) - return EXIT_FAILURE; + if (!username[0]) + 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; + } + 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: + 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); + if (!pw) { + strcpy(username, "UNKNOWN"); + goto fake_it; } - if (!( pw = getpwnam ( username ))) { - pw_copy.pw_name = "UNKNOWN"; - pw_copy.pw_passwd = "!"; - opt_fflag = 0; - failed = 1; - } else - pw_copy = *pw; - - pw = &pw_copy; - - 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()) + goto auth_failed; /* Don't check the password if password entry is empty (!) */ - if ( !pw-> pw_passwd[0] ) - goto auth_ok; - + if (!pw->pw_passwd[0]) + break; + fake_it: /* authorization takes place here */ - if ( correct_password ( pw )) - goto auth_ok; - - failed = 1; - -auth_ok: - if ( !failed) + if (correct_password(pw)) break; - +#endif /* ENABLE_PAM */ + auth_failed: + opt &= ~LOGIN_OPT_f; bb_do_delay(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); + if (++count == 3) { + 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 + alarm(0); + 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 ); + write_utent(&utent, username); -#ifdef CONFIG_SELINUX - if (is_selinux_enabled()) - { +#if ENABLE_SELINUX + if (is_selinux_enabled()) { security_context_t old_tty_sid, new_tty_sid; - if (get_default_context(username, NULL, &user_sid)) - { - fprintf(stderr, "Unable to get SID for %s\n", username); - exit(1); + if (get_default_context(username, NULL, &user_sid)) { + bb_error_msg_and_die("cannot get SID for %s", + username); } - if (getfilecon(full_tty, &old_tty_sid) < 0) - { - fprintf(stderr, "getfilecon(%.100s) failed: %.100s\n", full_tty, strerror(errno)); - return EXIT_FAILURE; + 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) - { - fprintf(stderr, "security_change_sid(%.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) { + bb_perror_msg_and_die("security_change_sid(%s) failed", + full_tty); } - 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; + if (setfilecon(full_tty, new_tty_sid) != 0) { + bb_perror_msg_and_die("chsid(%s, %s) failed", + full_tty, new_tty_sid); } } #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 ); + /* 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); + + /* 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"); + 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); + xspawn(t_argv); /* NOMMU-friendly */ + /* All variables are unset by setup_environment */ + wait(NULL); + } + } - change_identity ( pw ); - tmp = pw-> pw_shell; - if(!tmp || !*tmp) + change_identity(pw); + tmp = pw->pw_shell; + if (!tmp || !*tmp) tmp = DEFAULT_SHELL; - setup_environment ( tmp, 1, !opt_preserve, pw ); + /* setup_environment params: shell, loginshell, changeenv, pw */ + setup_environment(tmp, 1, !(opt & LOGIN_OPT_p), pw); + /* FIXME: login shell = 1 -> 3rd parameter is ignored! */ - motd ( ); - signal ( SIGALRM, SIG_DFL ); /* default alarm signal */ + motd(); - if ( pw-> pw_uid == 0 ) - syslog ( LOG_INFO, "root login %s\n", fromhost ); -#ifdef CONFIG_SELINUX + if (pw->pw_uid == 0) + syslog(LOG_INFO, "root login%s", fromhost); +#if ENABLE_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= 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; - } - } - fclose(fp); - 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 ( stat ( tty, &by_name ) || fstat ( 0, &by_fd )) - return 0; - - if ( by_name. st_rdev != by_fd. st_rdev ) - return 0; - else - return 1; -} - -static void motd (void) -{ - FILE *fp; - register int c; - - if (( fp = fopen ( bb_path_motd_file, "r" ))) { - while (( c = getc ( fp )) != EOF ) - putchar ( c ); - fclose ( fp ); - } -} - - -#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(); - - /* 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; - - /* 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((void *) &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); - } -} - -/* - * 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. - */ - -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(_PATH_WTMP, R_OK|W_OK) == -1) { - close(creat(_PATH_WTMP, 0664)); - } - updwtmp(_PATH_WTMP, &utent); -#endif + // 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 */ + 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); + + /* Exec login shell with no additional parameters */ + run_shell(tmp, 1, NULL, NULL); + + /* return EXIT_FAILURE; - not reached */ } -#endif /* CONFIG_FEATURE_UTMP */