diff options
| -rw-r--r-- | coreutils/who.c | 2 | ||||
| -rw-r--r-- | include/libbb.h | 6 | ||||
| -rw-r--r-- | init/halt.c | 1 | ||||
| -rw-r--r-- | libbb/Kbuild | 2 | ||||
| -rw-r--r-- | libbb/utmp.c | 92 | ||||
| -rw-r--r-- | loginutils/getty.c | 61 | ||||
| -rw-r--r-- | loginutils/login.c | 112 |
7 files changed, 117 insertions, 159 deletions
diff --git a/coreutils/who.c b/coreutils/who.c index dfbb4c046..2b4331025 100644 --- a/coreutils/who.c +++ b/coreutils/who.c @@ -16,7 +16,7 @@ * *---------------------------------------------------------------------- */ -/* BB_AUDIT SUSv3 _NOT_ compliant -- missing options -b, -d, -H, -l, -m, -p, -q, -r, -s, -t, -T, -u; Missing argument 'file'. */ +/* BB_AUDIT SUSv3 _NOT_ compliant -- missing options -b, -d, -l, -m, -p, -q, -r, -s, -t, -T, -u; Missing argument 'file'. */ #include "libbb.h" #include <utmp.h> diff --git a/include/libbb.h b/include/libbb.h index e674e4aea..ea61701b7 100644 --- a/include/libbb.h +++ b/include/libbb.h @@ -796,6 +796,12 @@ void die_if_bad_username(const char* name) FAST_FUNC; #define die_if_bad_username(name) ((void)(name)) #endif +#if ENABLE_FEATURE_UTMP +void FAST_FUNC update_utmp(int new_type, const char *short_tty, const char *username, const char *opt_host); +#else +# define update_utmp(new_type, short_tty, username, opt_host) ((void)0) +#endif + int execable_file(const char *name) FAST_FUNC; char *find_execable(const char *filename, char **PATHp) FAST_FUNC; int exists_execable(const char *filename) FAST_FUNC; diff --git a/init/halt.c b/init/halt.c index 16906dfe0..a3459ee48 100644 --- a/init/halt.c +++ b/init/halt.c @@ -30,7 +30,6 @@ static void write_wtmp(void) if (uname(&uts) == 0) safe_strncpy(utmp.ut_host, uts.release, sizeof(utmp.ut_host)); updwtmp(bb_path_wtmp_file, &utmp); - } #else #define write_wtmp() ((void)0) diff --git a/libbb/Kbuild b/libbb/Kbuild index 4606d5aa7..1b11d5d39 100644 --- a/libbb/Kbuild +++ b/libbb/Kbuild @@ -120,6 +120,8 @@ lib-y += xgethostbyname.o lib-y += xreadlink.o lib-y += xrealloc_vector.o +lib-$(CONFIG_FEATURE_UTMP) += utmp.o + # A mix of optimizations (why build stuff we know won't be used) # and objects which may fail to build (SELinux on selinux-less system) lib-$(CONFIG_SELINUX) += selinux_common.o diff --git a/libbb/utmp.c b/libbb/utmp.c new file mode 100644 index 000000000..06b939b9d --- /dev/null +++ b/libbb/utmp.c @@ -0,0 +1,92 @@ +/* vi: set sw=4 ts=4: */ +/* + * utmp/wtmp support routines. + * + * Copyright (C) 2010 Denys Vlasenko + * + * Licensed under GPL version 2, see file LICENSE in this tarball for details. + */ +#include "libbb.h" +#include <utmp.h> + +static void touch(const char *filename) +{ + if (access(filename, R_OK | W_OK) == -1) + close(open(filename, O_WRONLY | O_CREAT, 0664)); +} + +/* + * Read "man utmp" to make sense out of it. + */ +void FAST_FUNC update_utmp(int new_type, const char *short_tty, const char *username, const char *opt_host) +{ + struct utmp utent; + struct utmp *ut; + pid_t pid; + + touch(_PATH_UTMP); + utmpname(_PATH_UTMP); + setutent(); + + pid = getpid(); + /* Did init/getty/telnetd/sshd/... create an entry for us? + * It should be (new_type-1), but we'd also reuse + * any other potentially stale xxx_PROCESS entry */ + while ((ut = getutent()) != NULL) { + if (ut->ut_pid == pid + // && ut->ut_line[0] + && ut->ut_id[0] /* must have nonzero id */ + && ( ut->ut_type == INIT_PROCESS + || ut->ut_type == LOGIN_PROCESS + || ut->ut_type == USER_PROCESS + || ut->ut_type == DEAD_PROCESS + ) + ) { + utent = *ut; /* struct copy */ + if (ut->ut_type >= new_type) { + /* Stale record. Nuke hostname */ + memset(utent.ut_host, 0, sizeof(utent.ut_host)); + } + /* NB: pututline (see later) searches for matching utent + * using getutid(utent) - we must not change ut_id + * if we want *exactly this* record to be overwritten! + */ + break; + } + } + endutent(); + + if (!ut) { + /* Didn't find anything, create new one */ + memset(&utent, 0, sizeof(utent)); + utent.ut_pid = pid; + /* Invent our own ut_id. ut_id is only 4 chars wide. + * Try to fit something remotely meaningful... */ + if (short_tty[0] == 'p') { + /* if "ptyXXX", map to "pXXX" */ + /* if "pts/XX", map to "p/XX" */ + utent.ut_id[0] = 'p'; + strncpy(utent.ut_id + 1, short_tty + 3, sizeof(utent.ut_id)-1); + } else { + /* assuming it's "ttyXXXX", map to "XXXX" */ + strncpy(utent.ut_id, short_tty + 3, sizeof(utent.ut_id)); + } + } + + utent.ut_type = new_type; + safe_strncpy(utent.ut_line, short_tty, sizeof(utent.ut_line)); + safe_strncpy(utent.ut_user, username, sizeof(utent.ut_user)); + if (opt_host) + safe_strncpy(utent.ut_host, opt_host, sizeof(utent.ut_host)); + utent.ut_tv.tv_sec = time(NULL); + + /* Update, or append new one */ + setutent(); + pututline(&utent); + endutent(); + +#if ENABLE_FEATURE_WTMP + touch(bb_path_wtmp_file); + updwtmp(bb_path_wtmp_file, &utent); +#endif +} diff --git a/loginutils/getty.c b/loginutils/getty.c index 20411b04c..8d1d5254e 100644 --- a/loginutils/getty.c +++ b/loginutils/getty.c @@ -19,7 +19,7 @@ #include <syslog.h> #if ENABLE_FEATURE_UTMP -#include <utmp.h> /* updwtmp() */ +#include <utmp.h> /* LOGIN_PROCESS */ #endif #ifndef IUCLC @@ -575,61 +575,6 @@ static void termios_final(struct options *op, struct termios *tp, struct chardat ioctl_or_perror_and_die(0, TCSETS, tp, "%s: TCSETS", op->tty); } -#if ENABLE_FEATURE_UTMP -static void touch(const char *filename) -{ - if (access(filename, R_OK | W_OK) == -1) - close(open(filename, O_WRONLY | O_CREAT, 0664)); -} - -/* update_utmp - update our utmp entry */ -static NOINLINE void update_utmp(const char *line, char *fakehost) -{ - struct utmp ut; - struct utmp *utp; - int mypid = getpid(); - - /* In case we won't find an entry below... */ - memset(&ut, 0, sizeof(ut)); - safe_strncpy(ut.ut_id, line + 3, sizeof(ut.ut_id)); - - /* - * The utmp file holds miscellaneous information about things started by - * /sbin/init and other system-related events. Our purpose is to update - * the utmp entry for the current process, in particular the process type - * and the tty line we are listening to. Return successfully only if the - * utmp file can be opened for update, and if we are able to find our - * entry in the utmp file. - */ - touch(_PATH_UTMP); - - utmpname(_PATH_UTMP); - setutent(); - while ((utp = getutent()) != NULL) { - if (utp->ut_type == INIT_PROCESS && utp->ut_pid == mypid) { - memcpy(&ut, utp, sizeof(ut)); - break; - } - } - - strcpy(ut.ut_user, "LOGIN"); - safe_strncpy(ut.ut_line, line, sizeof(ut.ut_line)); - if (fakehost) - safe_strncpy(ut.ut_host, fakehost, sizeof(ut.ut_host)); - ut.ut_tv.tv_sec = time(NULL); - ut.ut_type = LOGIN_PROCESS; - ut.ut_pid = mypid; - - pututline(&ut); - endutent(); - -#if ENABLE_FEATURE_WTMP - touch(bb_path_wtmp_file); - updwtmp(bb_path_wtmp_file, &ut); -#endif -} -#endif /* CONFIG_FEATURE_UTMP */ - int getty_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int getty_main(int argc UNUSED_PARAM, char **argv) { @@ -715,10 +660,8 @@ int getty_main(int argc UNUSED_PARAM, char **argv) tcsetpgrp(0, getpid()); #endif -#if ENABLE_FEATURE_UTMP /* Update the utmp file. This tty is ours now! */ - update_utmp(options.tty, fakehost); -#endif + update_utmp(LOGIN_PROCESS, options.tty, "LOGIN", fakehost); /* Initialize the termios settings (raw mode, eight-bit, blocking i/o). */ debug("calling termios_init\n"); diff --git a/loginutils/login.c b/loginutils/login.c index 256c7c475..4a820379d 100644 --- a/loginutils/login.c +++ b/loginutils/login.c @@ -2,25 +2,26 @@ /* * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. */ - #include "libbb.h" #include <syslog.h> -#include <utmp.h> +#if ENABLE_FEATURE_UTMP +# include <utmp.h> /* USER_PROCESS */ +#endif #include <sys/resource.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 */ +# 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 #if ENABLE_PAM /* PAM may include <locale.h>. We may need to undefine bbox's stub define: */ -#undef setlocale +# 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> +# include <security/pam_appl.h> +# include <security/pam_misc.h> static const struct pam_conv conv = { misc_conv, NULL @@ -36,87 +37,6 @@ enum { 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 void read_or_build_utent(struct utmp *utptr, int run_by_root) -{ - struct utmp *ut; - pid_t pid = getpid(); - - setutent(); - - /* First, try to find a valid utmp entry for this process. */ - /* If there is one, just use it. */ - while ((ut = getutent()) != NULL) { - if (ut->ut_pid == pid && ut->ut_line[0] && ut->ut_id[0] - && (ut->ut_type == LOGIN_PROCESS || ut->ut_type == USER_PROCESS) - ) { - *utptr = *ut; /* struct copy */ - if (run_by_root) /* why only for root? */ - memset(utptr->ut_host, 0, sizeof(utptr->ut_host)); - return; - } - } - -// Why? Do we require non-root to exec login from another -// former login process (e.g. login shell)? Some login's have -// login shells as children, so it won't work... -// if (!run_by_root) -// bb_error_msg_and_die("no utmp entry found"); - - /* Otherwise create a new one. */ - 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_tv.tv_sec = time(NULL); -} - -/* - * 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_tv.tv_sec = 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, run_by_root) ((void)0) -#define write_utent(utptr, username) ((void)0) -#endif /* !ENABLE_FEATURE_UTMP */ - #if ENABLE_FEATURE_NOLOGIN static void die_if_nologin(void) { @@ -144,7 +64,7 @@ static void die_if_nologin(void) exit(EXIT_FAILURE); } #else -static ALWAYS_INLINE void die_if_nologin(void) {} +# define die_if_nologin() ((void)0) #endif #if ENABLE_FEATURE_SECURETTY && !ENABLE_PAM @@ -286,11 +206,10 @@ int login_main(int argc UNUSED_PARAM, char **argv) unsigned opt; int count = 0; struct passwd *pw; - char *opt_host = opt_host; /* for compiler */ + char *opt_host = NULL; char *opt_user = opt_user; /* for compiler */ char *full_tty; IF_SELINUX(security_context_t user_sid = NULL;) - IF_FEATURE_UTMP(struct utmp utent;) #if ENABLE_PAM int pamret; pam_handle_t *pamh; @@ -334,10 +253,7 @@ int login_main(int argc UNUSED_PARAM, char **argv) if (strncmp(full_tty, "/dev/", 5) == 0) short_tty += 5; - read_or_build_utent(&utent, run_by_root); - - if (opt & LOGIN_OPT_h) { - IF_FEATURE_UTMP(safe_strncpy(utent.ut_host, opt_host, sizeof(utent.ut_host));) + if (opt_host) { fromhost = xasprintf(" on '%s' from '%s'", short_tty, opt_host); } else { fromhost = xasprintf(" on '%s'", short_tty); @@ -461,8 +377,6 @@ int login_main(int argc UNUSED_PARAM, char **argv) if (pw->pw_uid != 0) die_if_nologin(); - write_utent(&utent, username); - IF_SELINUX(initselinux(username, full_tty, &user_sid)); /* Try these, but don't complain if they fail. @@ -470,6 +384,8 @@ int login_main(int argc UNUSED_PARAM, char **argv) fchown(0, pw->pw_uid, pw->pw_gid); fchmod(0, 0600); + update_utmp(USER_PROCESS, short_tty, username, run_by_root ? opt_host : NULL); + /* We trust environment only if we run by root */ if (ENABLE_LOGIN_SCRIPTS && run_by_root) run_login_script(pw, full_tty); |