diff options
Diffstat (limited to 'libmisc/utmp.c')
| -rw-r--r-- | libmisc/utmp.c | 474 |
1 files changed, 474 insertions, 0 deletions
diff --git a/libmisc/utmp.c b/libmisc/utmp.c new file mode 100644 index 0000000..45b479f --- /dev/null +++ b/libmisc/utmp.c @@ -0,0 +1,474 @@ +/* + * SPDX-FileCopyrightText: 1989 - 1994, Julianne Frances Haugh + * SPDX-FileCopyrightText: 1996 - 1999, Marek Michałkiewicz + * SPDX-FileCopyrightText: 2001 - 2005, Tomasz Kłoczko + * SPDX-FileCopyrightText: 2008 - 2009, Nicolas François + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include <config.h> + +#include "defines.h" +#include "prototypes.h" + +#ifdef USE_UTMPX +#include <utmpx.h> +#else +#include <utmp.h> +#endif + +#include <assert.h> +#include <sys/param.h> +#include <sys/types.h> +#include <sys/socket.h> +#include <netdb.h> +#include <stdio.h> + +#ident "$Id$" + + +/* + * is_my_tty -- determine if "tty" is the same TTY stdin is using + */ +static bool is_my_tty (const char *tty) +{ + /* full_tty shall be at least sizeof utmp.ut_line + 5 */ + char full_tty[200]; + /* tmptty shall be bigger than full_tty */ + static char tmptty[sizeof (full_tty)+1]; + + if ('/' != *tty) { + (void) snprintf (full_tty, sizeof full_tty, "/dev/%s", tty); + tty = &full_tty[0]; + } + + if ('\0' == tmptty[0]) { + const char *tname = ttyname (STDIN_FILENO); + if (NULL != tname) { + (void) strncpy (tmptty, tname, sizeof tmptty); + tmptty[sizeof (tmptty) - 1] = '\0'; + } + } + + if ('\0' == tmptty[0]) { + (void) puts (_("Unable to determine your tty name.")); + exit (EXIT_FAILURE); + } else if (strncmp (tty, tmptty, sizeof (tmptty)) != 0) { + return false; + } else { + return true; + } +} + +/* + * get_current_utmp - return the most probable utmp entry for the current + * session + * + * The utmp file is scanned for an entry with the same process ID. + * The line entered by the *getty / telnetd, etc. should also match + * the current terminal. + * + * When an entry is returned by get_current_utmp, and if the utmp + * structure has a ut_id field, this field should be used to update + * the entry information. + * + * Return NULL if no entries exist in utmp for the current process. + */ +#ifndef USE_UTMPX +/*@null@*/ /*@only@*/struct utmp *get_current_utmp (void) +{ + struct utmp *ut; + struct utmp *ret = NULL; + + setutent (); + + /* First, try to find a valid utmp entry for this process. */ + while ((ut = getutent ()) != NULL) { + if ( (ut->ut_pid == getpid ()) +#ifdef HAVE_STRUCT_UTMP_UT_ID + && ('\0' != ut->ut_id[0]) +#endif +#ifdef HAVE_STRUCT_UTMP_UT_TYPE + && ( (LOGIN_PROCESS == ut->ut_type) + || (USER_PROCESS == ut->ut_type)) +#endif + /* A process may have failed to close an entry + * Check if this entry refers to the current tty */ + && is_my_tty (ut->ut_line)) { + break; + } + } + + if (NULL != ut) { + ret = (struct utmp *) xmalloc (sizeof (*ret)); + memcpy (ret, ut, sizeof (*ret)); + } + + endutent (); + + return ret; +} +#else +/*@null@*/ /*@only*/struct utmpx *get_current_utmp(void) +{ + struct utmpx *ut; + struct utmpx *ret = NULL; + + setutxent (); + + /* Find the utmpx entry for this PID. */ + while ((ut = getutxent ()) != NULL) { + if ( (ut->ut_pid == getpid ()) + && ('\0' != ut->ut_id[0]) + && ( (LOGIN_PROCESS == ut->ut_type) + || (USER_PROCESS == ut->ut_type)) + && is_my_tty (ut->ut_line)) { + break; + } + } + + if (NULL != ut) { + ret = (struct utmpx *) xmalloc (sizeof (*ret)); + memcpy (ret, ut, sizeof (*ret)); + } + + endutxent (); + + return ret; +} +#endif + + +#ifndef USE_PAM +/* + * Some systems already have updwtmp() and possibly updwtmpx(). Others + * don't, so we re-implement these functions if necessary. + */ +#ifndef HAVE_UPDWTMP +static void updwtmp (const char *filename, const struct utmp *ut) +{ + int fd; + + fd = open (filename, O_APPEND | O_WRONLY, 0); + if (fd >= 0) { + write (fd, (const char *) ut, sizeof (*ut)); + close (fd); + } +} +#endif /* ! HAVE_UPDWTMP */ + +#ifdef USE_UTMPX +#ifndef HAVE_UPDWTMPX +static void updwtmpx (const char *filename, const struct utmpx *utx) +{ + int fd; + + fd = open (filename, O_APPEND | O_WRONLY, 0); + if (fd >= 0) { + write (fd, (const char *) utx, sizeof (*utx)); + close (fd); + } +} +#endif /* ! HAVE_UPDWTMPX */ +#endif /* ! USE_UTMPX */ +#endif /* ! USE_PAM */ + + +#ifndef USE_UTMPX +/* + * prepare_utmp - prepare an utmp entry so that it can be logged in a + * utmp/wtmp file. + * + * It accepts an utmp entry in input (ut) to return an entry with + * the right ut_id. This is typically an entry returned by + * get_current_utmp + * If ut is NULL, ut_id will be forged based on the line argument. + * + * The ut_host field of the input structure may also be kept, and is + * used to define the ut_addr/ut_addr_v6 fields. (if these fields + * exist) + * + * Other fields are discarded and filed with new values (if they + * exist). + * + * The returned structure shall be freed by the caller. + */ +/*@only@*/struct utmp *prepare_utmp (const char *name, + const char *line, + const char *host, + /*@null@*/const struct utmp *ut) +{ + struct timeval tv; + char *hostname = NULL; + struct utmp *utent; + + assert (NULL != name); + assert (NULL != line); + + + + if ( (NULL != host) + && ('\0' != host[0])) { + hostname = (char *) xmalloc (strlen (host) + 1); + strcpy (hostname, host); +#ifdef HAVE_STRUCT_UTMP_UT_HOST + } else if ( (NULL != ut) + && ('\0' != ut->ut_host[0])) { + hostname = (char *) xmalloc (sizeof (ut->ut_host) + 1); + strncpy (hostname, ut->ut_host, sizeof (ut->ut_host)); + hostname[sizeof (ut->ut_host)] = '\0'; +#endif /* HAVE_STRUCT_UTMP_UT_HOST */ + } + + if (strncmp(line, "/dev/", 5) == 0) { + line += 5; + } + + + utent = (struct utmp *) xmalloc (sizeof (*utent)); + memzero (utent, sizeof (*utent)); + + + +#ifdef HAVE_STRUCT_UTMP_UT_TYPE + utent->ut_type = USER_PROCESS; +#endif /* HAVE_STRUCT_UTMP_UT_TYPE */ + utent->ut_pid = getpid (); + strncpy (utent->ut_line, line, sizeof (utent->ut_line) - 1); +#ifdef HAVE_STRUCT_UTMP_UT_ID + if (NULL != ut) { + strncpy (utent->ut_id, ut->ut_id, sizeof (utent->ut_id)); + } else { + /* XXX - assumes /dev/tty?? */ + strncpy (utent->ut_id, line + 3, sizeof (utent->ut_id) - 1); + } +#endif /* HAVE_STRUCT_UTMP_UT_ID */ +#ifdef HAVE_STRUCT_UTMP_UT_NAME + strncpy (utent->ut_name, name, sizeof (utent->ut_name)); +#endif /* HAVE_STRUCT_UTMP_UT_NAME */ +#ifdef HAVE_STRUCT_UTMP_UT_USER + strncpy (utent->ut_user, name, sizeof (utent->ut_user) - 1); +#endif /* HAVE_STRUCT_UTMP_UT_USER */ + if (NULL != hostname) { + struct addrinfo *info = NULL; +#ifdef HAVE_STRUCT_UTMP_UT_HOST + strncpy (utent->ut_host, hostname, sizeof (utent->ut_host) - 1); +#endif /* HAVE_STRUCT_UTMP_UT_HOST */ +#ifdef HAVE_STRUCT_UTMP_UT_SYSLEN + utent->ut_syslen = MIN (strlen (hostname), + sizeof (utent->ut_host)); +#endif /* HAVE_STRUCT_UTMP_UT_SYSLEN */ +#if defined(HAVE_STRUCT_UTMP_UT_ADDR) || defined(HAVE_STRUCT_UTMP_UT_ADDR_V6) + if (getaddrinfo (hostname, NULL, NULL, &info) == 0) { + /* getaddrinfo might not be reliable. + * Just try to log what may be useful. + */ + if (info->ai_family == AF_INET) { + struct sockaddr_in *sa = + (struct sockaddr_in *) info->ai_addr; +#ifdef HAVE_STRUCT_UTMP_UT_ADDR + memcpy (&(utent->ut_addr), + &(sa->sin_addr), + MIN (sizeof (utent->ut_addr), + sizeof (sa->sin_addr))); +#endif /* HAVE_STRUCT_UTMP_UT_ADDR */ +#ifdef HAVE_STRUCT_UTMP_UT_ADDR_V6 + memcpy (utent->ut_addr_v6, + &(sa->sin_addr), + MIN (sizeof (utent->ut_addr_v6), + sizeof (sa->sin_addr))); + } else if (info->ai_family == AF_INET6) { + struct sockaddr_in6 *sa = + (struct sockaddr_in6 *) info->ai_addr; + memcpy (utent->ut_addr_v6, + &(sa->sin6_addr), + MIN (sizeof (utent->ut_addr_v6), + sizeof (sa->sin6_addr))); +#endif /* HAVE_STRUCT_UTMP_UT_ADDR_V6 */ + } + freeaddrinfo (info); + } +#endif /* HAVE_STRUCT_UTMP_UT_ADDR || HAVE_STRUCT_UTMP_UT_ADDR_V6 */ + free (hostname); + } + /* ut_exit is only for DEAD_PROCESS */ + utent->ut_session = getsid (0); + if (gettimeofday (&tv, NULL) == 0) { +#ifdef HAVE_STRUCT_UTMP_UT_TIME + utent->ut_time = tv.tv_sec; +#endif /* HAVE_STRUCT_UTMP_UT_TIME */ +#ifdef HAVE_STRUCT_UTMP_UT_XTIME + utent->ut_xtime = tv.tv_usec; +#endif /* HAVE_STRUCT_UTMP_UT_XTIME */ +#ifdef HAVE_STRUCT_UTMP_UT_TV + utent->ut_tv.tv_sec = tv.tv_sec; + utent->ut_tv.tv_usec = tv.tv_usec; +#endif /* HAVE_STRUCT_UTMP_UT_TV */ + } + + return utent; +} + +/* + * setutmp - Update an entry in utmp and log an entry in wtmp + * + * Return 1 on failure and 0 on success. + */ +int setutmp (struct utmp *ut) +{ + int err = 0; + + assert (NULL != ut); + + setutent (); + if (pututline (ut) == NULL) { + err = 1; + } + endutent (); + +#ifndef USE_PAM + /* This is done by pam_lastlog */ + updwtmp (_WTMP_FILE, ut); +#endif /* ! USE_PAM */ + + return err; +} + +#else +/* + * prepare_utmpx - the UTMPX version for prepare_utmp + */ +/*@only@*/struct utmpx *prepare_utmpx (const char *name, + const char *line, + const char *host, + /*@null@*/const struct utmpx *ut) +{ + struct timeval tv; + char *hostname = NULL; + struct utmpx *utxent; + + assert (NULL != name); + assert (NULL != line); + + + + if ( (NULL != host) + && ('\0' != host[0])) { + hostname = (char *) xmalloc (strlen (host) + 1); + strcpy (hostname, host); +#ifdef HAVE_STRUCT_UTMP_UT_HOST + } else if ( (NULL != ut) + && (NULL != ut->ut_host) + && ('\0' != ut->ut_host[0])) { + hostname = (char *) xmalloc (sizeof (ut->ut_host) + 1); + strncpy (hostname, ut->ut_host, sizeof (ut->ut_host)); + hostname[sizeof (ut->ut_host)] = '\0'; +#endif /* HAVE_STRUCT_UTMP_UT_TYPE */ + } + + if (strncmp(line, "/dev/", 5) == 0) { + line += 5; + } + + utxent = (struct utmpx *) xmalloc (sizeof (*utxent)); + memzero (utxent, sizeof (*utxent)); + + + + utxent->ut_type = USER_PROCESS; + utxent->ut_pid = getpid (); + strncpy (utxent->ut_line, line, sizeof (utxent->ut_line)); + /* existence of ut->ut_id is enforced by configure */ + if (NULL != ut) { + strncpy (utxent->ut_id, ut->ut_id, sizeof (utxent->ut_id)); + } else { + /* XXX - assumes /dev/tty?? */ + strncpy (utxent->ut_id, line + 3, sizeof (utxent->ut_id)); + } +#ifdef HAVE_STRUCT_UTMPX_UT_NAME + strncpy (utxent->ut_name, name, sizeof (utxent->ut_name)); +#endif /* HAVE_STRUCT_UTMPX_UT_NAME */ + strncpy (utxent->ut_user, name, sizeof (utxent->ut_user)); + if (NULL != hostname) { + struct addrinfo *info = NULL; +#ifdef HAVE_STRUCT_UTMPX_UT_HOST + strncpy (utxent->ut_host, hostname, sizeof (utxent->ut_host)); +#endif /* HAVE_STRUCT_UTMPX_UT_HOST */ +#ifdef HAVE_STRUCT_UTMPX_UT_SYSLEN + utxent->ut_syslen = MIN (strlen (hostname), + sizeof (utxent->ut_host)); +#endif /* HAVE_STRUCT_UTMPX_UT_SYSLEN */ +#if defined(HAVE_STRUCT_UTMPX_UT_ADDR) || defined(HAVE_STRUCT_UTMPX_UT_ADDR_V6) + if (getaddrinfo (hostname, NULL, NULL, &info) == 0) { + /* getaddrinfo might not be reliable. + * Just try to log what may be useful. + */ + if (info->ai_family == AF_INET) { + struct sockaddr_in *sa = + (struct sockaddr_in *) info->ai_addr; +#ifdef HAVE_STRUCT_UTMPX_UT_ADDR + memcpy (&utxent->ut_addr, + &(sa->sin_addr), + MIN (sizeof (utxent->ut_addr), + sizeof (sa->sin_addr))); +#endif /* HAVE_STRUCT_UTMPX_UT_ADDR */ +#ifdef HAVE_STRUCT_UTMPX_UT_ADDR_V6 + memcpy (utxent->ut_addr_v6, + &(sa->sin_addr), + MIN (sizeof (utxent->ut_addr_v6), + sizeof (sa->sin_addr))); + } else if (info->ai_family == AF_INET6) { + struct sockaddr_in6 *sa = + (struct sockaddr_in6 *) info->ai_addr; + memcpy (utxent->ut_addr_v6, + &(sa->sin6_addr), + MIN (sizeof (utxent->ut_addr_v6), + sizeof (sa->sin6_addr))); +#endif /* HAVE_STRUCT_UTMPX_UT_ADDR_V6 */ + } + freeaddrinfo (info); + } +#endif /* HAVE_STRUCT_UTMPX_UT_ADDR || HAVE_STRUCT_UTMPX_UT_ADDR_V6 */ + free (hostname); + } + /* ut_exit is only for DEAD_PROCESS */ + utxent->ut_session = getsid (0); + if (gettimeofday (&tv, NULL) == 0) { +#ifdef HAVE_STRUCT_UTMPX_UT_TIME + utxent->ut_time = tv.tv_sec; +#endif /* HAVE_STRUCT_UTMPX_UT_TIME */ +#ifdef HAVE_STRUCT_UTMPX_UT_XTIME + utxent->ut_xtime = tv.tv_usec; +#endif /* HAVE_STRUCT_UTMPX_UT_XTIME */ + utxent->ut_tv.tv_sec = tv.tv_sec; + utxent->ut_tv.tv_usec = tv.tv_usec; + } + + return utxent; +} + +/* + * setutmpx - the UTMPX version for setutmp + */ +int setutmpx (struct utmpx *utx) +{ + int err = 0; + + assert (NULL != utx); + + setutxent (); + if (pututxline (utx) == NULL) { + err = 1; + } + endutxent (); + +#ifndef USE_PAM + /* This is done by pam_lastlog */ + updwtmpx (_WTMP_FILE "x", utx); +#endif /* ! USE_PAM */ + + return err; +} +#endif /* USE_UTMPX */ + |