X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=loginutils%2Flogin.c;h=3d8b8e540b0c7a39ac216b990964f3bee0c368d0;hb=24efe4f15fe45151681b41333f3713357ce8694b;hp=78a2ba117ae21257d67938ae65593c1867a735a4;hpb=7ccf5cc0644ab4399b570781a42f3aeff7b98a07;p=oweals%2Fbusybox.git diff --git a/loginutils/login.c b/loginutils/login.c index 78a2ba117..3d8b8e540 100644 --- a/loginutils/login.c +++ b/loginutils/login.c @@ -8,7 +8,7 @@ #include #include -#ifdef CONFIG_SELINUX +#if ENABLE_SELINUX #include /* for is_selinux_enabled() */ #include /* for get_default_context() */ #include /* for security class definitions */ @@ -22,8 +22,7 @@ enum { 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 */ @@ -40,8 +39,8 @@ static char* short_tty = full_tty; * 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(); @@ -56,23 +55,23 @@ static void read_or_build_utent(int picky) /* 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)); } /* @@ -81,26 +80,26 @@ static void read_or_build_utent(int picky) * 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) { @@ -136,7 +135,7 @@ static int check_securetty(void) 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; } @@ -193,70 +192,51 @@ static void motd(void) } } -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 */ @@ -270,20 +250,20 @@ int login_main(int argc, char **argv) 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]) @@ -298,7 +278,7 @@ int login_main(int argc, char **argv) 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()) @@ -306,18 +286,18 @@ int login_main(int argc, char **argv) /* 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; } @@ -327,27 +307,27 @@ auth_failed: 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); } } @@ -358,23 +338,23 @@ auth_failed: 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); } } @@ -382,10 +362,9 @@ auth_failed: 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); @@ -394,7 +373,24 @@ auth_failed: * 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; }