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freebsd-nq/crypto/openssh/loginrec.c
Dag-Erling Smørgrav 333ee03933 Merge conflicts. 
MFC after:	1 week
2006-09-30 13:38:06 +00:00

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/*
* Copyright (c) 2000 Andre Lucas. All rights reserved.
* Portions copyright (c) 1998 Todd C. Miller
* Portions copyright (c) 1996 Jason Downs
* Portions copyright (c) 1996 Theo de Raadt
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* The btmp logging code is derived from login.c from util-linux and is under
* the the following license:
*
* Copyright (c) 1980, 1987, 1988 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley. The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
/**
** loginrec.c: platform-independent login recording and lastlog retrieval
**/
/*
* The new login code explained
* ============================
*
* This code attempts to provide a common interface to login recording
* (utmp and friends) and last login time retrieval.
*
* Its primary means of achieving this is to use 'struct logininfo', a
* union of all the useful fields in the various different types of
* system login record structures one finds on UNIX variants.
*
* We depend on autoconf to define which recording methods are to be
* used, and which fields are contained in the relevant data structures
* on the local system. Many C preprocessor symbols affect which code
* gets compiled here.
*
* The code is designed to make it easy to modify a particular
* recording method, without affecting other methods nor requiring so
* many nested conditional compilation blocks as were commonplace in
* the old code.
*
* For login recording, we try to use the local system's libraries as
* these are clearly most likely to work correctly. For utmp systems
* this usually means login() and logout() or setutent() etc., probably
* in libutil, along with logwtmp() etc. On these systems, we fall back
* to writing the files directly if we have to, though this method
* requires very thorough testing so we do not corrupt local auditing
* information. These files and their access methods are very system
* specific indeed.
*
* For utmpx systems, the corresponding library functions are
* setutxent() etc. To the author's knowledge, all utmpx systems have
* these library functions and so no direct write is attempted. If such
* a system exists and needs support, direct analogues of the [uw]tmp
* code should suffice.
*
* Retrieving the time of last login ('lastlog') is in some ways even
* more problemmatic than login recording. Some systems provide a
* simple table of all users which we seek based on uid and retrieve a
* relatively standard structure. Others record the same information in
* a directory with a separate file, and others don't record the
* information separately at all. For systems in the latter category,
* we look backwards in the wtmp or wtmpx file for the last login entry
* for our user. Naturally this is slower and on busy systems could
* incur a significant performance penalty.
*
* Calling the new code
* --------------------
*
* In OpenSSH all login recording and retrieval is performed in
* login.c. Here you'll find working examples. Also, in the logintest.c
* program there are more examples.
*
* Internal handler calling method
* -------------------------------
*
* When a call is made to login_login() or login_logout(), both
* routines set a struct logininfo flag defining which action (log in,
* or log out) is to be taken. They both then call login_write(), which
* calls whichever of the many structure-specific handlers autoconf
* selects for the local system.
*
* The handlers themselves handle system data structure specifics. Both
* struct utmp and struct utmpx have utility functions (see
* construct_utmp*()) to try to make it simpler to add extra systems
* that introduce new features to either structure.
*
* While it may seem terribly wasteful to replicate so much similar
* code for each method, experience has shown that maintaining code to
* write both struct utmp and utmpx in one function, whilst maintaining
* support for all systems whether they have library support or not, is
* a difficult and time-consuming task.
*
* Lastlog support proceeds similarly. Functions login_get_lastlog()
* (and its OpenSSH-tuned friend login_get_lastlog_time()) call
* getlast_entry(), which tries one of three methods to find the last
* login time. It uses local system lastlog support if it can,
* otherwise it tries wtmp or wtmpx before giving up and returning 0,
* meaning "tilt".
*
* Maintenance
* -----------
*
* In many cases it's possible to tweak autoconf to select the correct
* methods for a particular platform, either by improving the detection
* code (best), or by presetting DISABLE_<method> or CONF_<method>_FILE
* symbols for the platform.
*
* Use logintest to check which symbols are defined before modifying
* configure.ac and loginrec.c. (You have to build logintest yourself
* with 'make logintest' as it's not built by default.)
*
* Otherwise, patches to the specific method(s) are very helpful!
*/
#include "includes.h"
__RCSID("$FreeBSD$");
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <errno.h>
#include <fcntl.h>
#ifdef HAVE_PATHS_H
# include <paths.h>
#endif
#include <pwd.h>
#include <stdarg.h>
#include <string.h>
#include <unistd.h>
#include "xmalloc.h"
#include "key.h"
#include "hostfile.h"
#include "ssh.h"
#include "loginrec.h"
#include "log.h"
#include "atomicio.h"
#include "packet.h"
#include "canohost.h"
#include "auth.h"
#include "buffer.h"
#ifdef HAVE_UTIL_H
# include <util.h>
#endif
#ifdef HAVE_LIBUTIL_H
# include <libutil.h>
#endif
/**
** prototypes for helper functions in this file
**/
#if HAVE_UTMP_H
void set_utmp_time(struct logininfo *li, struct utmp *ut);
void construct_utmp(struct logininfo *li, struct utmp *ut);
#endif
#ifdef HAVE_UTMPX_H
void set_utmpx_time(struct logininfo *li, struct utmpx *ut);
void construct_utmpx(struct logininfo *li, struct utmpx *ut);
#endif
int utmp_write_entry(struct logininfo *li);
int utmpx_write_entry(struct logininfo *li);
int wtmp_write_entry(struct logininfo *li);
int wtmpx_write_entry(struct logininfo *li);
int lastlog_write_entry(struct logininfo *li);
int syslogin_write_entry(struct logininfo *li);
int getlast_entry(struct logininfo *li);
int lastlog_get_entry(struct logininfo *li);
int wtmp_get_entry(struct logininfo *li);
int wtmpx_get_entry(struct logininfo *li);
extern Buffer loginmsg;
/* pick the shortest string */
#define MIN_SIZEOF(s1,s2) (sizeof(s1) < sizeof(s2) ? sizeof(s1) : sizeof(s2))
/**
** platform-independent login functions
**/
/*
* login_login(struct logininfo *) - Record a login
*
* Call with a pointer to a struct logininfo initialised with
* login_init_entry() or login_alloc_entry()
*
* Returns:
* >0 if successful
* 0 on failure (will use OpenSSH's logging facilities for diagnostics)
*/
int
login_login(struct logininfo *li)
{
li->type = LTYPE_LOGIN;
return (login_write(li));
}
/*
* login_logout(struct logininfo *) - Record a logout
*
* Call as with login_login()
*
* Returns:
* >0 if successful
* 0 on failure (will use OpenSSH's logging facilities for diagnostics)
*/
int
login_logout(struct logininfo *li)
{
li->type = LTYPE_LOGOUT;
return (login_write(li));
}
/*
* login_get_lastlog_time(int) - Retrieve the last login time
*
* Retrieve the last login time for the given uid. Will try to use the
* system lastlog facilities if they are available, but will fall back
* to looking in wtmp/wtmpx if necessary
*
* Returns:
* 0 on failure, or if user has never logged in
* Time in seconds from the epoch if successful
*
* Useful preprocessor symbols:
* DISABLE_LASTLOG: If set, *never* even try to retrieve lastlog
* info
* USE_LASTLOG: If set, indicates the presence of system lastlog
* facilities. If this and DISABLE_LASTLOG are not set,
* try to retrieve lastlog information from wtmp/wtmpx.
*/
unsigned int
login_get_lastlog_time(const int uid)
{
struct logininfo li;
if (login_get_lastlog(&li, uid))
return (li.tv_sec);
else
return (0);
}
/*
* login_get_lastlog(struct logininfo *, int) - Retrieve a lastlog entry
*
* Retrieve a logininfo structure populated (only partially) with
* information from the system lastlog data, or from wtmp/wtmpx if no
* system lastlog information exists.
*
* Note this routine must be given a pre-allocated logininfo.
*
* Returns:
* >0: A pointer to your struct logininfo if successful
* 0 on failure (will use OpenSSH's logging facilities for diagnostics)
*/
struct logininfo *
login_get_lastlog(struct logininfo *li, const int uid)
{
struct passwd *pw;
memset(li, '\0', sizeof(*li));
li->uid = uid;
/*
* If we don't have a 'real' lastlog, we need the username to
* reliably search wtmp(x) for the last login (see
* wtmp_get_entry().)
*/
pw = getpwuid(uid);
if (pw == NULL)
fatal("%s: Cannot find account for uid %i", __func__, uid);
/* No MIN_SIZEOF here - we absolutely *must not* truncate the
* username (XXX - so check for trunc!) */
strlcpy(li->username, pw->pw_name, sizeof(li->username));
if (getlast_entry(li))
return (li);
else
return (NULL);
}
/*
* login_alloc_entry(int, char*, char*, char*) - Allocate and initialise
* a logininfo structure
*
* This function creates a new struct logininfo, a data structure
* meant to carry the information required to portably record login info.
*
* Returns a pointer to a newly created struct logininfo. If memory
* allocation fails, the program halts.
*/
struct
logininfo *login_alloc_entry(int pid, const char *username,
const char *hostname, const char *line)
{
struct logininfo *newli;
newli = xmalloc(sizeof(*newli));
login_init_entry(newli, pid, username, hostname, line);
return (newli);
}
/* login_free_entry(struct logininfo *) - free struct memory */
void
login_free_entry(struct logininfo *li)
{
xfree(li);
}
/* login_init_entry(struct logininfo *, int, char*, char*, char*)
* - initialise a struct logininfo
*
* Populates a new struct logininfo, a data structure meant to carry
* the information required to portably record login info.
*
* Returns: 1
*/
int
login_init_entry(struct logininfo *li, int pid, const char *username,
const char *hostname, const char *line)
{
struct passwd *pw;
memset(li, 0, sizeof(*li));
li->pid = pid;
/* set the line information */
if (line)
line_fullname(li->line, line, sizeof(li->line));
if (username) {
strlcpy(li->username, username, sizeof(li->username));
pw = getpwnam(li->username);
if (pw == NULL) {
fatal("%s: Cannot find user \"%s\"", __func__,
li->username);
}
li->uid = pw->pw_uid;
}
if (hostname)
strlcpy(li->hostname, hostname, sizeof(li->hostname));
return (1);
}
/*
* login_set_current_time(struct logininfo *) - set the current time
*
* Set the current time in a logininfo structure. This function is
* meant to eliminate the need to deal with system dependencies for
* time handling.
*/
void
login_set_current_time(struct logininfo *li)
{
struct timeval tv;
gettimeofday(&tv, NULL);
li->tv_sec = tv.tv_sec;
li->tv_usec = tv.tv_usec;
}
/* copy a sockaddr_* into our logininfo */
void
login_set_addr(struct logininfo *li, const struct sockaddr *sa,
const unsigned int sa_size)
{
unsigned int bufsize = sa_size;
/* make sure we don't overrun our union */
if (sizeof(li->hostaddr) < sa_size)
bufsize = sizeof(li->hostaddr);
memcpy(&li->hostaddr.sa, sa, bufsize);
}
/**
** login_write: Call low-level recording functions based on autoconf
** results
**/
int
login_write(struct logininfo *li)
{
#ifndef HAVE_CYGWIN
if (geteuid() != 0) {
logit("Attempt to write login records by non-root user (aborting)");
return (1);
}
#endif
/* set the timestamp */
login_set_current_time(li);
#ifdef USE_LOGIN
syslogin_write_entry(li);
#endif
#ifdef USE_LASTLOG
if (li->type == LTYPE_LOGIN)
lastlog_write_entry(li);
#endif
#ifdef USE_UTMP
utmp_write_entry(li);
#endif
#ifdef USE_WTMP
wtmp_write_entry(li);
#endif
#ifdef USE_UTMPX
utmpx_write_entry(li);
#endif
#ifdef USE_WTMPX
wtmpx_write_entry(li);
#endif
#ifdef CUSTOM_SYS_AUTH_RECORD_LOGIN
if (li->type == LTYPE_LOGIN &&
!sys_auth_record_login(li->username,li->hostname,li->line,
&loginmsg))
logit("Writing login record failed for %s", li->username);
#endif
#ifdef SSH_AUDIT_EVENTS
if (li->type == LTYPE_LOGIN)
audit_session_open(li->line);
else if (li->type == LTYPE_LOGOUT)
audit_session_close(li->line);
#endif
return (0);
}
#ifdef LOGIN_NEEDS_UTMPX
int
login_utmp_only(struct logininfo *li)
{
li->type = LTYPE_LOGIN;
login_set_current_time(li);
# ifdef USE_UTMP
utmp_write_entry(li);
# endif
# ifdef USE_WTMP
wtmp_write_entry(li);
# endif
# ifdef USE_UTMPX
utmpx_write_entry(li);
# endif
# ifdef USE_WTMPX
wtmpx_write_entry(li);
# endif
return (0);
}
#endif
/**
** getlast_entry: Call low-level functions to retrieve the last login
** time.
**/
/* take the uid in li and return the last login time */
int
getlast_entry(struct logininfo *li)
{
#ifdef USE_LASTLOG
return(lastlog_get_entry(li));
#else /* !USE_LASTLOG */
#if defined(DISABLE_LASTLOG)
/* On some systems we shouldn't even try to obtain last login
* time, e.g. AIX */
return (0);
# elif defined(USE_WTMP) && \
(defined(HAVE_TIME_IN_UTMP) || defined(HAVE_TV_IN_UTMP))
/* retrieve last login time from utmp */
return (wtmp_get_entry(li));
# elif defined(USE_WTMPX) && \
(defined(HAVE_TIME_IN_UTMPX) || defined(HAVE_TV_IN_UTMPX))
/* If wtmp isn't available, try wtmpx */
return (wtmpx_get_entry(li));
# else
/* Give up: No means of retrieving last login time */
return (0);
# endif /* DISABLE_LASTLOG */
#endif /* USE_LASTLOG */
}
/*
* 'line' string utility functions
*
* These functions process the 'line' string into one of three forms:
*
* 1. The full filename (including '/dev')
* 2. The stripped name (excluding '/dev')
* 3. The abbreviated name (e.g. /dev/ttyp00 -> yp00
* /dev/pts/1 -> ts/1 )
*
* Form 3 is used on some systems to identify a .tmp.? entry when
* attempting to remove it. Typically both addition and removal is
* performed by one application - say, sshd - so as long as the choice
* uniquely identifies a terminal it's ok.
*/
/*
* line_fullname(): add the leading '/dev/' if it doesn't exist make
* sure dst has enough space, if not just copy src (ugh)
*/
char *
line_fullname(char *dst, const char *src, u_int dstsize)
{
memset(dst, '\0', dstsize);
if ((strncmp(src, "/dev/", 5) == 0) || (dstsize < (strlen(src) + 5)))
strlcpy(dst, src, dstsize);
else {
strlcpy(dst, "/dev/", dstsize);
strlcat(dst, src, dstsize);
}
return (dst);
}
/* line_stripname(): strip the leading '/dev' if it exists, return dst */
char *
line_stripname(char *dst, const char *src, int dstsize)
{
memset(dst, '\0', dstsize);
if (strncmp(src, "/dev/", 5) == 0)
strlcpy(dst, src + 5, dstsize);
else
strlcpy(dst, src, dstsize);
return (dst);
}
/*
* line_abbrevname(): Return the abbreviated (usually four-character)
* form of the line (Just use the last <dstsize> characters of the
* full name.)
*
* NOTE: use strncpy because we do NOT necessarily want zero
* termination
*/
char *
line_abbrevname(char *dst, const char *src, int dstsize)
{
size_t len;
memset(dst, '\0', dstsize);
/* Always skip prefix if present */
if (strncmp(src, "/dev/", 5) == 0)
src += 5;
#ifdef WITH_ABBREV_NO_TTY
if (strncmp(src, "tty", 3) == 0)
src += 3;
#endif
len = strlen(src);
if (len > 0) {
if (((int)len - dstsize) > 0)
src += ((int)len - dstsize);
/* note: _don't_ change this to strlcpy */
strncpy(dst, src, (size_t)dstsize);
}
return (dst);
}
/**
** utmp utility functions
**
** These functions manipulate struct utmp, taking system differences
** into account.
**/
#if defined(USE_UTMP) || defined (USE_WTMP) || defined (USE_LOGIN)
/* build the utmp structure */
void
set_utmp_time(struct logininfo *li, struct utmp *ut)
{
# if defined(HAVE_TV_IN_UTMP)
ut->ut_tv.tv_sec = li->tv_sec;
ut->ut_tv.tv_usec = li->tv_usec;
# elif defined(HAVE_TIME_IN_UTMP)
ut->ut_time = li->tv_sec;
# endif
}
void
construct_utmp(struct logininfo *li,
struct utmp *ut)
{
# ifdef HAVE_ADDR_V6_IN_UTMP
struct sockaddr_in6 *sa6;
# endif
memset(ut, '\0', sizeof(*ut));
/* First fill out fields used for both logins and logouts */
# ifdef HAVE_ID_IN_UTMP
line_abbrevname(ut->ut_id, li->line, sizeof(ut->ut_id));
# endif
# ifdef HAVE_TYPE_IN_UTMP
/* This is done here to keep utmp constants out of struct logininfo */
switch (li->type) {
case LTYPE_LOGIN:
ut->ut_type = USER_PROCESS;
#ifdef _UNICOS
cray_set_tmpdir(ut);
#endif
break;
case LTYPE_LOGOUT:
ut->ut_type = DEAD_PROCESS;
#ifdef _UNICOS
cray_retain_utmp(ut, li->pid);
#endif
break;
}
# endif
set_utmp_time(li, ut);
line_stripname(ut->ut_line, li->line, sizeof(ut->ut_line));
# ifdef HAVE_PID_IN_UTMP
ut->ut_pid = li->pid;
# endif
/* If we're logging out, leave all other fields blank */
if (li->type == LTYPE_LOGOUT)
return;
/*
* These fields are only used when logging in, and are blank
* for logouts.
*/
/* Use strncpy because we don't necessarily want null termination */
strncpy(ut->ut_name, li->username,
MIN_SIZEOF(ut->ut_name, li->username));
# ifdef HAVE_HOST_IN_UTMP
realhostname_sa(ut->ut_host, sizeof ut->ut_host,
&li->hostaddr.sa, li->hostaddr.sa.sa_len);
# endif
# ifdef HAVE_ADDR_IN_UTMP
/* this is just a 32-bit IP address */
if (li->hostaddr.sa.sa_family == AF_INET)
ut->ut_addr = li->hostaddr.sa_in.sin_addr.s_addr;
# endif
# ifdef HAVE_ADDR_V6_IN_UTMP
/* this is just a 128-bit IPv6 address */
if (li->hostaddr.sa.sa_family == AF_INET6) {
sa6 = ((struct sockaddr_in6 *)&li->hostaddr.sa);
memcpy(ut->ut_addr_v6, sa6->sin6_addr.s6_addr, 16);
if (IN6_IS_ADDR_V4MAPPED(&sa6->sin6_addr)) {
ut->ut_addr_v6[0] = ut->ut_addr_v6[3];
ut->ut_addr_v6[1] = 0;
ut->ut_addr_v6[2] = 0;
ut->ut_addr_v6[3] = 0;
}
}
# endif
}
#endif /* USE_UTMP || USE_WTMP || USE_LOGIN */
/**
** utmpx utility functions
**
** These functions manipulate struct utmpx, accounting for system
** variations.
**/
#if defined(USE_UTMPX) || defined (USE_WTMPX)
/* build the utmpx structure */
void
set_utmpx_time(struct logininfo *li, struct utmpx *utx)
{
# if defined(HAVE_TV_IN_UTMPX)
utx->ut_tv.tv_sec = li->tv_sec;
utx->ut_tv.tv_usec = li->tv_usec;
# elif defined(HAVE_TIME_IN_UTMPX)
utx->ut_time = li->tv_sec;
# endif
}
void
construct_utmpx(struct logininfo *li, struct utmpx *utx)
{
# ifdef HAVE_ADDR_V6_IN_UTMP
struct sockaddr_in6 *sa6;
# endif
memset(utx, '\0', sizeof(*utx));
# ifdef HAVE_ID_IN_UTMPX
line_abbrevname(utx->ut_id, li->line, sizeof(utx->ut_id));
# endif
/* this is done here to keep utmp constants out of loginrec.h */
switch (li->type) {
case LTYPE_LOGIN:
utx->ut_type = USER_PROCESS;
break;
case LTYPE_LOGOUT:
utx->ut_type = DEAD_PROCESS;
break;
}
line_stripname(utx->ut_line, li->line, sizeof(utx->ut_line));
set_utmpx_time(li, utx);
utx->ut_pid = li->pid;
/* strncpy(): Don't necessarily want null termination */
strncpy(utx->ut_name, li->username,
MIN_SIZEOF(utx->ut_name, li->username));
if (li->type == LTYPE_LOGOUT)
return;
/*
* These fields are only used when logging in, and are blank
* for logouts.
*/
# ifdef HAVE_HOST_IN_UTMPX
strncpy(utx->ut_host, li->hostname,
MIN_SIZEOF(utx->ut_host, li->hostname));
# endif
# ifdef HAVE_ADDR_IN_UTMPX
/* this is just a 32-bit IP address */
if (li->hostaddr.sa.sa_family == AF_INET)
utx->ut_addr = li->hostaddr.sa_in.sin_addr.s_addr;
# endif
# ifdef HAVE_ADDR_V6_IN_UTMP
/* this is just a 128-bit IPv6 address */
if (li->hostaddr.sa.sa_family == AF_INET6) {
sa6 = ((struct sockaddr_in6 *)&li->hostaddr.sa);
memcpy(ut->ut_addr_v6, sa6->sin6_addr.s6_addr, 16);
if (IN6_IS_ADDR_V4MAPPED(&sa6->sin6_addr)) {
ut->ut_addr_v6[0] = ut->ut_addr_v6[3];
ut->ut_addr_v6[1] = 0;
ut->ut_addr_v6[2] = 0;
ut->ut_addr_v6[3] = 0;
}
}
# endif
# ifdef HAVE_SYSLEN_IN_UTMPX
/* ut_syslen is the length of the utx_host string */
utx->ut_syslen = MIN(strlen(li->hostname), sizeof(utx->ut_host));
# endif
}
#endif /* USE_UTMPX || USE_WTMPX */
/**
** Low-level utmp functions
**/
/* FIXME: (ATL) utmp_write_direct needs testing */
#ifdef USE_UTMP
/* if we can, use pututline() etc. */
# if !defined(DISABLE_PUTUTLINE) && defined(HAVE_SETUTENT) && \
defined(HAVE_PUTUTLINE)
# define UTMP_USE_LIBRARY
# endif
/* write a utmp entry with the system's help (pututline() and pals) */
# ifdef UTMP_USE_LIBRARY
static int
utmp_write_library(struct logininfo *li, struct utmp *ut)
{
setutent();
pututline(ut);
# ifdef HAVE_ENDUTENT
endutent();
# endif
return (1);
}
# else /* UTMP_USE_LIBRARY */
/*
* Write a utmp entry direct to the file
* This is a slightly modification of code in OpenBSD's login.c
*/
static int
utmp_write_direct(struct logininfo *li, struct utmp *ut)
{
struct utmp old_ut;
register int fd;
int tty;
/* FIXME: (ATL) ttyslot() needs local implementation */
#if defined(HAVE_GETTTYENT)
struct ttyent *ty;
tty=0;
setttyent();
while (NULL != (ty = getttyent())) {
tty++;
if (!strncmp(ty->ty_name, ut->ut_line, sizeof(ut->ut_line)))
break;
}
endttyent();
if (NULL == ty) {
logit("%s: tty not found", __func__);
return (0);
}
#else /* FIXME */
tty = ttyslot(); /* seems only to work for /dev/ttyp? style names */
#endif /* HAVE_GETTTYENT */
if (tty > 0 && (fd = open(UTMP_FILE, O_RDWR|O_CREAT, 0644)) >= 0) {
off_t pos, ret;
pos = (off_t)tty * sizeof(struct utmp);
if ((ret = lseek(fd, pos, SEEK_SET)) == -1) {
logit("%s: lseek: %s", __func__, strerror(errno));
return (0);
}
if (ret != pos) {
logit("%s: Couldn't seek to tty %d slot in %s",
__func__, tty, UTMP_FILE);
return (0);
}
/*
* Prevent luser from zero'ing out ut_host.
* If the new ut_line is empty but the old one is not
* and ut_line and ut_name match, preserve the old ut_line.
*/
if (atomicio(read, fd, &old_ut, sizeof(old_ut)) == sizeof(old_ut) &&
(ut->ut_host[0] == '\0') && (old_ut.ut_host[0] != '\0') &&
(strncmp(old_ut.ut_line, ut->ut_line, sizeof(ut->ut_line)) == 0) &&
(strncmp(old_ut.ut_name, ut->ut_name, sizeof(ut->ut_name)) == 0))
memcpy(ut->ut_host, old_ut.ut_host, sizeof(ut->ut_host));
if ((ret = lseek(fd, pos, SEEK_SET)) == -1) {
logit("%s: lseek: %s", __func__, strerror(errno));
return (0);
}
if (ret != pos) {
logit("%s: Couldn't seek to tty %d slot in %s",
__func__, tty, UTMP_FILE);
return (0);
}
if (atomicio(vwrite, fd, ut, sizeof(*ut)) != sizeof(*ut)) {
logit("%s: error writing %s: %s", __func__,
UTMP_FILE, strerror(errno));
}
close(fd);
return (1);
} else {
return (0);
}
}
# endif /* UTMP_USE_LIBRARY */
static int
utmp_perform_login(struct logininfo *li)
{
struct utmp ut;
construct_utmp(li, &ut);
# ifdef UTMP_USE_LIBRARY
if (!utmp_write_library(li, &ut)) {
logit("%s: utmp_write_library() failed", __func__);
return (0);
}
# else
if (!utmp_write_direct(li, &ut)) {
logit("%s: utmp_write_direct() failed", __func__);
return (0);
}
# endif
return (1);
}
static int
utmp_perform_logout(struct logininfo *li)
{
struct utmp ut;
construct_utmp(li, &ut);
# ifdef UTMP_USE_LIBRARY
if (!utmp_write_library(li, &ut)) {
logit("%s: utmp_write_library() failed", __func__);
return (0);
}
# else
if (!utmp_write_direct(li, &ut)) {
logit("%s: utmp_write_direct() failed", __func__);
return (0);
}
# endif
return (1);
}
int
utmp_write_entry(struct logininfo *li)
{
switch(li->type) {
case LTYPE_LOGIN:
return (utmp_perform_login(li));
case LTYPE_LOGOUT:
return (utmp_perform_logout(li));
default:
logit("%s: invalid type field", __func__);
return (0);
}
}
#endif /* USE_UTMP */
/**
** Low-level utmpx functions
**/
/* not much point if we don't want utmpx entries */
#ifdef USE_UTMPX
/* if we have the wherewithall, use pututxline etc. */
# if !defined(DISABLE_PUTUTXLINE) && defined(HAVE_SETUTXENT) && \
defined(HAVE_PUTUTXLINE)
# define UTMPX_USE_LIBRARY
# endif
/* write a utmpx entry with the system's help (pututxline() and pals) */
# ifdef UTMPX_USE_LIBRARY
static int
utmpx_write_library(struct logininfo *li, struct utmpx *utx)
{
setutxent();
pututxline(utx);
# ifdef HAVE_ENDUTXENT
endutxent();
# endif
return (1);
}
# else /* UTMPX_USE_LIBRARY */
/* write a utmp entry direct to the file */
static int
utmpx_write_direct(struct logininfo *li, struct utmpx *utx)
{
logit("%s: not implemented!", __func__);
return (0);
}
# endif /* UTMPX_USE_LIBRARY */
static int
utmpx_perform_login(struct logininfo *li)
{
struct utmpx utx;
construct_utmpx(li, &utx);
# ifdef UTMPX_USE_LIBRARY
if (!utmpx_write_library(li, &utx)) {
logit("%s: utmp_write_library() failed", __func__);
return (0);
}
# else
if (!utmpx_write_direct(li, &ut)) {
logit("%s: utmp_write_direct() failed", __func__);
return (0);
}
# endif
return (1);
}
static int
utmpx_perform_logout(struct logininfo *li)
{
struct utmpx utx;
construct_utmpx(li, &utx);
# ifdef HAVE_ID_IN_UTMPX
line_abbrevname(utx.ut_id, li->line, sizeof(utx.ut_id));
# endif
# ifdef HAVE_TYPE_IN_UTMPX
utx.ut_type = DEAD_PROCESS;
# endif
# ifdef UTMPX_USE_LIBRARY
utmpx_write_library(li, &utx);
# else
utmpx_write_direct(li, &utx);
# endif
return (1);
}
int
utmpx_write_entry(struct logininfo *li)
{
switch(li->type) {
case LTYPE_LOGIN:
return (utmpx_perform_login(li));
case LTYPE_LOGOUT:
return (utmpx_perform_logout(li));
default:
logit("%s: invalid type field", __func__);
return (0);
}
}
#endif /* USE_UTMPX */
/**
** Low-level wtmp functions
**/
#ifdef USE_WTMP
/*
* Write a wtmp entry direct to the end of the file
* This is a slight modification of code in OpenBSD's logwtmp.c
*/
static int
wtmp_write(struct logininfo *li, struct utmp *ut)
{
struct stat buf;
int fd, ret = 1;
if ((fd = open(WTMP_FILE, O_WRONLY|O_APPEND, 0)) < 0) {
logit("%s: problem writing %s: %s", __func__,
WTMP_FILE, strerror(errno));
return (0);
}
if (fstat(fd, &buf) == 0)
if (atomicio(vwrite, fd, ut, sizeof(*ut)) != sizeof(*ut)) {
ftruncate(fd, buf.st_size);
logit("%s: problem writing %s: %s", __func__,
WTMP_FILE, strerror(errno));
ret = 0;
}
close(fd);
return (ret);
}
static int
wtmp_perform_login(struct logininfo *li)
{
struct utmp ut;
construct_utmp(li, &ut);
return (wtmp_write(li, &ut));
}
static int
wtmp_perform_logout(struct logininfo *li)
{
struct utmp ut;
construct_utmp(li, &ut);
return (wtmp_write(li, &ut));
}
int
wtmp_write_entry(struct logininfo *li)
{
switch(li->type) {
case LTYPE_LOGIN:
return (wtmp_perform_login(li));
case LTYPE_LOGOUT:
return (wtmp_perform_logout(li));
default:
logit("%s: invalid type field", __func__);
return (0);
}
}
/*
* Notes on fetching login data from wtmp/wtmpx
*
* Logouts are usually recorded with (amongst other things) a blank
* username on a given tty line. However, some systems (HP-UX is one)
* leave all fields set, but change the ut_type field to DEAD_PROCESS.
*
* Since we're only looking for logins here, we know that the username
* must be set correctly. On systems that leave it in, we check for
* ut_type==USER_PROCESS (indicating a login.)
*
* Portability: Some systems may set something other than USER_PROCESS
* to indicate a login process. I don't know of any as I write. Also,
* it's possible that some systems may both leave the username in
* place and not have ut_type.
*/
/* return true if this wtmp entry indicates a login */
static int
wtmp_islogin(struct logininfo *li, struct utmp *ut)
{
if (strncmp(li->username, ut->ut_name,
MIN_SIZEOF(li->username, ut->ut_name)) == 0) {
# ifdef HAVE_TYPE_IN_UTMP
if (ut->ut_type & USER_PROCESS)
return (1);
# else
return (1);
# endif
}
return (0);
}
int
wtmp_get_entry(struct logininfo *li)
{
struct stat st;
struct utmp ut;
int fd, found = 0;
/* Clear the time entries in our logininfo */
li->tv_sec = li->tv_usec = 0;
if ((fd = open(WTMP_FILE, O_RDONLY)) < 0) {
logit("%s: problem opening %s: %s", __func__,
WTMP_FILE, strerror(errno));
return (0);
}
if (fstat(fd, &st) != 0) {
logit("%s: couldn't stat %s: %s", __func__,
WTMP_FILE, strerror(errno));
close(fd);
return (0);
}
/* Seek to the start of the last struct utmp */
if (lseek(fd, -(off_t)sizeof(struct utmp), SEEK_END) == -1) {
/* Looks like we've got a fresh wtmp file */
close(fd);
return (0);
}
while (!found) {
if (atomicio(read, fd, &ut, sizeof(ut)) != sizeof(ut)) {
logit("%s: read of %s failed: %s", __func__,
WTMP_FILE, strerror(errno));
close (fd);
return (0);
}
if ( wtmp_islogin(li, &ut) ) {
found = 1;
/*
* We've already checked for a time in struct
* utmp, in login_getlast()
*/
# ifdef HAVE_TIME_IN_UTMP
li->tv_sec = ut.ut_time;
# else
# if HAVE_TV_IN_UTMP
li->tv_sec = ut.ut_tv.tv_sec;
# endif
# endif
line_fullname(li->line, ut.ut_line,
MIN_SIZEOF(li->line, ut.ut_line));
# ifdef HAVE_HOST_IN_UTMP
strlcpy(li->hostname, ut.ut_host,
MIN_SIZEOF(li->hostname, ut.ut_host));
# endif
continue;
}
/* Seek back 2 x struct utmp */
if (lseek(fd, -(off_t)(2 * sizeof(struct utmp)), SEEK_CUR) == -1) {
/* We've found the start of the file, so quit */
close(fd);
return (0);
}
}
/* We found an entry. Tidy up and return */
close(fd);
return (1);
}
# endif /* USE_WTMP */
/**
** Low-level wtmpx functions
**/
#ifdef USE_WTMPX
/*
* Write a wtmpx entry direct to the end of the file
* This is a slight modification of code in OpenBSD's logwtmp.c
*/
static int
wtmpx_write(struct logininfo *li, struct utmpx *utx)
{
#ifndef HAVE_UPDWTMPX
struct stat buf;
int fd, ret = 1;
if ((fd = open(WTMPX_FILE, O_WRONLY|O_APPEND, 0)) < 0) {
logit("%s: problem opening %s: %s", __func__,
WTMPX_FILE, strerror(errno));
return (0);
}
if (fstat(fd, &buf) == 0)
if (atomicio(vwrite, fd, utx, sizeof(*utx)) != sizeof(*utx)) {
ftruncate(fd, buf.st_size);
logit("%s: problem writing %s: %s", __func__,
WTMPX_FILE, strerror(errno));
ret = 0;
}
close(fd);
return (ret);
#else
updwtmpx(WTMPX_FILE, utx);
return (1);
#endif
}
static int
wtmpx_perform_login(struct logininfo *li)
{
struct utmpx utx;
construct_utmpx(li, &utx);
return (wtmpx_write(li, &utx));
}
static int
wtmpx_perform_logout(struct logininfo *li)
{
struct utmpx utx;
construct_utmpx(li, &utx);
return (wtmpx_write(li, &utx));
}
int
wtmpx_write_entry(struct logininfo *li)
{
switch(li->type) {
case LTYPE_LOGIN:
return (wtmpx_perform_login(li));
case LTYPE_LOGOUT:
return (wtmpx_perform_logout(li));
default:
logit("%s: invalid type field", __func__);
return (0);
}
}
/* Please see the notes above wtmp_islogin() for information about the
next two functions */
/* Return true if this wtmpx entry indicates a login */
static int
wtmpx_islogin(struct logininfo *li, struct utmpx *utx)
{
if (strncmp(li->username, utx->ut_name,
MIN_SIZEOF(li->username, utx->ut_name)) == 0 ) {
# ifdef HAVE_TYPE_IN_UTMPX
if (utx->ut_type == USER_PROCESS)
return (1);
# else
return (1);
# endif
}
return (0);
}
int
wtmpx_get_entry(struct logininfo *li)
{
struct stat st;
struct utmpx utx;
int fd, found=0;
/* Clear the time entries */
li->tv_sec = li->tv_usec = 0;
if ((fd = open(WTMPX_FILE, O_RDONLY)) < 0) {
logit("%s: problem opening %s: %s", __func__,
WTMPX_FILE, strerror(errno));
return (0);
}
if (fstat(fd, &st) != 0) {
logit("%s: couldn't stat %s: %s", __func__,
WTMPX_FILE, strerror(errno));
close(fd);
return (0);
}
/* Seek to the start of the last struct utmpx */
if (lseek(fd, -(off_t)sizeof(struct utmpx), SEEK_END) == -1 ) {
/* probably a newly rotated wtmpx file */
close(fd);
return (0);
}
while (!found) {
if (atomicio(read, fd, &utx, sizeof(utx)) != sizeof(utx)) {
logit("%s: read of %s failed: %s", __func__,
WTMPX_FILE, strerror(errno));
close (fd);
return (0);
}
/*
* Logouts are recorded as a blank username on a particular
* line. So, we just need to find the username in struct utmpx
*/
if (wtmpx_islogin(li, &utx)) {
found = 1;
# if defined(HAVE_TV_IN_UTMPX)
li->tv_sec = utx.ut_tv.tv_sec;
# elif defined(HAVE_TIME_IN_UTMPX)
li->tv_sec = utx.ut_time;
# endif
line_fullname(li->line, utx.ut_line, sizeof(li->line));
# if defined(HAVE_HOST_IN_UTMPX)
strlcpy(li->hostname, utx.ut_host,
MIN_SIZEOF(li->hostname, utx.ut_host));
# endif
continue;
}
if (lseek(fd, -(off_t)(2 * sizeof(struct utmpx)), SEEK_CUR) == -1) {
close(fd);
return (0);
}
}
close(fd);
return (1);
}
#endif /* USE_WTMPX */
/**
** Low-level libutil login() functions
**/
#ifdef USE_LOGIN
static int
syslogin_perform_login(struct logininfo *li)
{
struct utmp *ut;
ut = xmalloc(sizeof(*ut));
construct_utmp(li, ut);
login(ut);
free(ut);
return (1);
}
static int
syslogin_perform_logout(struct logininfo *li)
{
# ifdef HAVE_LOGOUT
char line[UT_LINESIZE];
(void)line_stripname(line, li->line, sizeof(line));
if (!logout(line))
logit("%s: logout() returned an error", __func__);
# ifdef HAVE_LOGWTMP
else
logwtmp(line, "", "");
# endif
/* FIXME: (ATL - if the need arises) What to do if we have
* login, but no logout? what if logout but no logwtmp? All
* routines are in libutil so they should all be there,
* but... */
# endif
return (1);
}
int
syslogin_write_entry(struct logininfo *li)
{
switch (li->type) {
case LTYPE_LOGIN:
return (syslogin_perform_login(li));
case LTYPE_LOGOUT:
return (syslogin_perform_logout(li));
default:
logit("%s: Invalid type field", __func__);
return (0);
}
}
#endif /* USE_LOGIN */
/* end of file log-syslogin.c */
/**
** Low-level lastlog functions
**/
#ifdef USE_LASTLOG
#define LL_FILE 1
#define LL_DIR 2
#define LL_OTHER 3
static void
lastlog_construct(struct logininfo *li, struct lastlog *last)
{
/* clear the structure */
memset(last, '\0', sizeof(*last));
line_stripname(last->ll_line, li->line, sizeof(last->ll_line));
strlcpy(last->ll_host, li->hostname,
MIN_SIZEOF(last->ll_host, li->hostname));
last->ll_time = li->tv_sec;
}
static int
lastlog_filetype(char *filename)
{
struct stat st;
if (stat(LASTLOG_FILE, &st) != 0) {
logit("%s: Couldn't stat %s: %s", __func__,
LASTLOG_FILE, strerror(errno));
return (0);
}
if (S_ISDIR(st.st_mode))
return (LL_DIR);
else if (S_ISREG(st.st_mode))
return (LL_FILE);
else
return (LL_OTHER);
}
/* open the file (using filemode) and seek to the login entry */
static int
lastlog_openseek(struct logininfo *li, int *fd, int filemode)
{
off_t offset;
int type;
char lastlog_file[1024];
type = lastlog_filetype(LASTLOG_FILE);
switch (type) {
case LL_FILE:
strlcpy(lastlog_file, LASTLOG_FILE,
sizeof(lastlog_file));
break;
case LL_DIR:
snprintf(lastlog_file, sizeof(lastlog_file), "%s/%s",
LASTLOG_FILE, li->username);
break;
default:
logit("%s: %.100s is not a file or directory!", __func__,
LASTLOG_FILE);
return (0);
}
*fd = open(lastlog_file, filemode, 0600);
if (*fd < 0) {
debug("%s: Couldn't open %s: %s", __func__,
lastlog_file, strerror(errno));
return (0);
}
if (type == LL_FILE) {
/* find this uid's offset in the lastlog file */
offset = (off_t) ((long)li->uid * sizeof(struct lastlog));
if (lseek(*fd, offset, SEEK_SET) != offset) {
logit("%s: %s->lseek(): %s", __func__,
lastlog_file, strerror(errno));
return (0);
}
}
return (1);
}
static int
lastlog_perform_login(struct logininfo *li)
{
struct lastlog last;
int fd;
/* create our struct lastlog */
lastlog_construct(li, &last);
if (!lastlog_openseek(li, &fd, O_RDWR|O_CREAT))
return (0);
/* write the entry */
if (atomicio(vwrite, fd, &last, sizeof(last)) != sizeof(last)) {
close(fd);
logit("%s: Error writing to %s: %s", __func__,
LASTLOG_FILE, strerror(errno));
return (0);
}
close(fd);
return (1);
}
int
lastlog_write_entry(struct logininfo *li)
{
switch(li->type) {
case LTYPE_LOGIN:
return (lastlog_perform_login(li));
default:
logit("%s: Invalid type field", __func__);
return (0);
}
}
static void
lastlog_populate_entry(struct logininfo *li, struct lastlog *last)
{
line_fullname(li->line, last->ll_line, sizeof(li->line));
strlcpy(li->hostname, last->ll_host,
MIN_SIZEOF(li->hostname, last->ll_host));
li->tv_sec = last->ll_time;
}
int
lastlog_get_entry(struct logininfo *li)
{
struct lastlog last;
int fd, ret;
if (!lastlog_openseek(li, &fd, O_RDONLY))
return (0);
ret = atomicio(read, fd, &last, sizeof(last));
close(fd);
switch (ret) {
case 0:
memset(&last, '\0', sizeof(last));
/* FALLTHRU */
case sizeof(last):
lastlog_populate_entry(li, &last);
return (1);
case -1:
error("%s: Error reading from %s: %s", __func__,
LASTLOG_FILE, strerror(errno));
return (0);
default:
error("%s: Error reading from %s: Expecting %d, got %d",
__func__, LASTLOG_FILE, (int)sizeof(last), ret);
return (0);
}
/* NOTREACHED */
return (0);
}
#endif /* USE_LASTLOG */
#ifdef USE_BTMP
/*
* Logs failed login attempts in _PATH_BTMP if that exists.
* The most common login failure is to give password instead of username.
* So the _PATH_BTMP file checked for the correct permission, so that
* only root can read it.
*/
void
record_failed_login(const char *username, const char *hostname,
const char *ttyn)
{
int fd;
struct utmp ut;
struct sockaddr_storage from;
socklen_t fromlen = sizeof(from);
struct sockaddr_in *a4;
struct sockaddr_in6 *a6;
time_t t;
struct stat fst;
if (geteuid() != 0)
return;
if ((fd = open(_PATH_BTMP, O_WRONLY | O_APPEND)) < 0) {
debug("Unable to open the btmp file %s: %s", _PATH_BTMP,
strerror(errno));
return;
}
if (fstat(fd, &fst) < 0) {
logit("%s: fstat of %s failed: %s", __func__, _PATH_BTMP,
strerror(errno));
goto out;
}
if((fst.st_mode & (S_IRWXG | S_IRWXO)) || (fst.st_uid != 0)){
logit("Excess permission or bad ownership on file %s",
_PATH_BTMP);
goto out;
}
memset(&ut, 0, sizeof(ut));
/* strncpy because we don't necessarily want nul termination */
strncpy(ut.ut_user, username, sizeof(ut.ut_user));
strlcpy(ut.ut_line, "ssh:notty", sizeof(ut.ut_line));
time(&t);
ut.ut_time = t; /* ut_time is not always a time_t */
ut.ut_type = LOGIN_PROCESS;
ut.ut_pid = getpid();
/* strncpy because we don't necessarily want nul termination */
strncpy(ut.ut_host, hostname, sizeof(ut.ut_host));
if (packet_connection_is_on_socket() &&
getpeername(packet_get_connection_in(),
(struct sockaddr *)&from, &fromlen) == 0) {
ipv64_normalise_mapped(&from, &fromlen);
if (from.ss_family == AF_INET) {
a4 = (struct sockaddr_in *)&from;
memcpy(&ut.ut_addr, &(a4->sin_addr),
MIN_SIZEOF(ut.ut_addr, a4->sin_addr));
}
#ifdef HAVE_ADDR_V6_IN_UTMP
if (from.ss_family == AF_INET6) {
a6 = (struct sockaddr_in6 *)&from;
memcpy(&ut.ut_addr_v6, &(a6->sin6_addr),
MIN_SIZEOF(ut.ut_addr_v6, a6->sin6_addr));
}
#endif
}
if (atomicio(vwrite, fd, &ut, sizeof(ut)) != sizeof(ut))
error("Failed to write to %s: %s", _PATH_BTMP,
strerror(errno));
out:
close(fd);
}
#endif /* USE_BTMP */
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