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/*
* pam_tally.c
*
* Revision history? :) 0.1
*/
/* By Tim Baverstock <warwick@mmm.co.uk>, Multi Media Machine Ltd.
* 5 March 1997
*
* Stuff stolen from pam_rootok and pam_listfile
*/
#ifdef linux
# define _GNU_SOURCE
# include <features.h>
#endif
#include <stdio.h>
#include <strings.h>
#include <unistd.h>
#include <stdarg.h>
#include <syslog.h>
#include <pwd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h>
#ifndef TRUE
#define TRUE 1L
#define FALSE 0L
#endif
/*
* here, we make a definition for the externally accessible function
* in this file (this definition is required for static a module
* but strongly encouraged generally) it is used to instruct the
* modules include file to define the function prototypes.
*/
#define PAM_SM_AUTH
#define PAM_SM_ACCOUNT
/* #define PAM_SM_SESSION */
/* #define PAM_SM_PASSWORD */
#include <security/pam_modules.h>
/*---------------------------------------------------------------------*/
#define DEFAULT_LOGFILE "/var/log/faillog"
#define MODULE_NAME "pam_tally"
enum TALLY_RESET {
TALLY_RESET_DEFAULT,
TALLY_RESET_RESET,
TALLY_RESET_NO_RESET
};
#define tally_t unsigned short int
#define TALLY_FMT "%hu"
#define TALLY_HI ((tally_t)~0L)
#define UID_FMT "%hu"
#ifndef FILENAME_MAX
# define FILENAME_MAX MAXPATHLEN
#endif
/*---------------------------------------------------------------------*/
/* some syslogging */
static void _pam_log(int err, const char *format, ...)
{
va_list args;
va_start(args, format);
#ifdef MAIN
vfprintf(stderr,format,args);
#else
openlog(MODULE_NAME, LOG_CONS|LOG_PID, LOG_AUTH);
vsyslog(err, format, args);
closelog();
#endif
va_end(args);
}
/*---------------------------------------------------------------------*/
/* --- Support function: get uid (and optionally username) from PAM or
cline_user --- */
#ifdef MAIN
static char *cline_user=0; /* cline_user is used in the administration prog */
#endif
static int pam_get_uid( pam_handle_t *pamh, uid_t *uid, const char **userp )
{
const char *user;
struct passwd *pw;
#ifdef MAIN
user = cline_user;
#else
pam_get_user( pamh, &user, NULL );
#endif
if ( !user || !*user ) {
_pam_log(LOG_ERR, MODULE_NAME ": pam_get_uid; user?");
return PAM_AUTH_ERR;
}
if ( ! ( pw = getpwnam( user ) ) ) {
_pam_log(LOG_ERR,MODULE_NAME ": pam_get_uid; no such user %s",user);
return PAM_USER_UNKNOWN;
}
if ( uid ) *uid = pw->pw_uid;
if ( userp ) *userp = user;
return PAM_SUCCESS;
}
/*---------------------------------------------------------------------*/
/* --- Support function: open/create tallyfile and return tally for uid --- */
/* If on entry *tally==TALLY_HI, tallyfile is opened READONLY */
/* Otherwise, if on entry tallyfile doesn't exist, creation is attempted. */
static int get_tally( tally_t *tally,
uid_t uid,
const char *filename,
FILE **TALLY )
{
struct stat fileinfo;
int lstat_ret = lstat(filename,&fileinfo);
if ( lstat_ret && *tally!=TALLY_HI ) {
if ( ( *TALLY=fopen(filename, "a") ) ) {
/* Create file, or append-open in pathological case. */
_pam_log(LOG_ALERT, "Couldn't create %s",filename);
return PAM_AUTH_ERR;
}
fclose(*TALLY);
lstat_ret = lstat(filename,&fileinfo);
}
if ( lstat_ret ) {
_pam_log(LOG_ALERT, "Couldn't stat %s",filename);
return PAM_AUTH_ERR;
}
if((fileinfo.st_mode & S_IWOTH) || !S_ISREG(fileinfo.st_mode)) {
/* If the file is world writable or is not a
normal file, return error */
_pam_log(LOG_ALERT,
"%s is either world writable or not a normal file",
filename);
return PAM_AUTH_ERR;
}
if ( ! ( *TALLY = fopen(filename,(*tally!=TALLY_HI)?"r+":"r") ) ) {
_pam_log(LOG_ALERT, "Error opening %s for update", filename);
/* Discovering why account service fails: e/uid are target user.
*
* perror(MODULE_NAME);
* fprintf(stderr,"uid %d euid %d\n",getuid(), geteuid());
*/
return PAM_AUTH_ERR;
}
if ( fseek( *TALLY, uid * sizeof (tally_t), SEEK_SET ) ) {
_pam_log(LOG_ALERT, "fseek failed %s", filename);
return PAM_AUTH_ERR;
}
if ( ( fread(tally, sizeof(tally_t), 1, *TALLY) )==0 ) {
*tally=0; /* Assuming a gappy filesystem */
}
return PAM_SUCCESS;
}
/*---------------------------------------------------------------------*/
/* --- Support function: update and close tallyfile with tally!=TALLY_HI --- */
static int set_tally( tally_t tally,
uid_t uid,
const char *filename,
FILE **TALLY )
{
if ( tally!=TALLY_HI )
{
if ( fseek( *TALLY, uid * sizeof(tally_t), SEEK_SET ) ) {
_pam_log(LOG_ALERT, "fseek failed %s", filename);
return PAM_AUTH_ERR;
}
if ( fwrite(&tally, sizeof(tally_t), 1, *TALLY)==0 ) {
_pam_log(LOG_ALERT, "tally update (fputc) failed.", filename);
return PAM_AUTH_ERR;
}
}
if ( fclose(*TALLY) ) {
_pam_log(LOG_ALERT, "tally update (fclose) failed.", filename);
return PAM_AUTH_ERR;
}
*TALLY=NULL;
return PAM_SUCCESS;
}
/*---------------------------------------------------------------------*/
/* --- PAM bits --- */
#ifndef MAIN
#define PAM_FUNCTION(name) \
PAM_EXTERN int name (pam_handle_t *pamh,int flags,int argc,const char **argv)
#define RETURN_ERROR(i) return ((fail_on_error)?(i):(PAM_SUCCESS))
/*---------------------------------------------------------------------*/
/* --- tally bump function: bump tally for uid by (signed) inc --- */
static int tally_bump (int inc,
pam_handle_t *pamh,
int flags,
int argc,
const char **argv) {
uid_t uid;
int
fail_on_error = FALSE;
tally_t
tally = 0; /* !TALLY_HI --> Log opened for update */
char
no_magic_root = FALSE;
char
filename[ FILENAME_MAX ] = DEFAULT_LOGFILE;
/* Should probably decode the parameters before anything else. */
{
for ( ; argc-- > 0; ++argv ) {
/* generic options.. um, ignored. :] */
if ( ! strcmp( *argv, "no_magic_root" ) ) {
no_magic_root = TRUE;
}
else if ( ! strncmp( *argv, "file=", 5 ) ) {
char const
*from = (*argv)+5;
char
*to = filename;
if ( *from!='/' || strlen(from)>FILENAME_MAX-1 ) {
_pam_log(LOG_ERR,
MODULE_NAME ": filename not /rooted or too long; ",
*argv);
RETURN_ERROR( PAM_AUTH_ERR );
}
while ( ( *to++ = *from++ ) );
}
else if ( ! strcmp( *argv, "onerr=fail" ) ) {
fail_on_error=TRUE;
}
else if ( ! strcmp( *argv, "onerr=succeed" ) ) {
fail_on_error=FALSE;
}
else {
_pam_log(LOG_ERR, MODULE_NAME ": unknown option; %s",*argv);
}
} /* for() */
}
{
FILE
*TALLY = NULL;
const char
*user = NULL;
int i=pam_get_uid(pamh, &uid, &user);
if ( i != PAM_SUCCESS ) RETURN_ERROR( i );
i=get_tally( &tally, uid, filename, &TALLY );
if ( i != PAM_SUCCESS ) { if (TALLY) fclose(TALLY); RETURN_ERROR( i ); }
if ( no_magic_root || getuid() ) { /* no_magic_root kills uid test */
tally+=inc;
if ( tally==TALLY_HI ) { /* Overflow *and* underflow. :) */
tally-=inc;
_pam_log(LOG_ALERT,"Tally %sflowed for user %s",
(inc<0)?"under":"over",user);
}
}
i=set_tally( tally, uid, filename, &TALLY );
if ( i != PAM_SUCCESS ) { if (TALLY) fclose(TALLY); RETURN_ERROR( i ); }
}
return PAM_SUCCESS;
}
/*---------------------------------------------------------------------*/
/* --- authentication management functions (only) --- */
#ifdef PAM_SM_AUTH
PAM_FUNCTION( pam_sm_authenticate ) {
return tally_bump( 1, pamh, flags, argc, argv);
}
/* --- Seems to need this function. Ho hum. --- */
PAM_FUNCTION( pam_sm_setcred ) { return PAM_SUCCESS; }
#endif
/*---------------------------------------------------------------------*/
/* --- session management functions (only) --- */
/*
* Unavailable until .so files can be suid
*/
#ifdef PAM_SM_SESSION
/* To maintain a balance-tally of successful login/outs */
PAM_FUNCTION( pam_sm_open_session ) {
return tally_bump( 1, pamh, flags, argc, argv);
}
PAM_FUNCTION( pam_sm_close_session ) {
return tally_bump(-1, pamh, flags, argc, argv);
}
#endif
/*---------------------------------------------------------------------*/
/* --- authentication management functions (only) --- */
#ifdef PAM_SM_AUTH
/* To lock out a user with an unacceptably high tally */
PAM_FUNCTION( pam_sm_acct_mgmt ) {
uid_t
uid;
int
fail_on_error = FALSE;
tally_t
deny = 0;
tally_t
tally = 0; /* !TALLY_HI --> Log opened for update */
char
no_magic_root = FALSE,
even_deny_root_account = FALSE;
const char
*user = NULL;
enum TALLY_RESET
reset = TALLY_RESET_DEFAULT;
char
filename[ FILENAME_MAX ] = DEFAULT_LOGFILE;
/* Should probably decode the parameters before anything else. */
{
for ( ; argc-- > 0; ++argv ) {
/* generic options.. um, ignored. :] */
if ( ! strcmp( *argv, "no_magic_root" ) ) {
no_magic_root = TRUE;
}
else if ( ! strcmp( *argv, "even_deny_root_account" ) ) {
even_deny_root_account = TRUE;
}
else if ( ! strcmp( *argv, "reset" ) ) {
reset = TALLY_RESET_RESET;
}
else if ( ! strcmp( *argv, "no_reset" ) ) {
reset = TALLY_RESET_NO_RESET;
}
else if ( ! strncmp( *argv, "file=", 5 ) ) {
char const
*from = (*argv)+5;
char
*to = filename;
if ( *from != '/' || strlen(from) > FILENAME_MAX-1 ) {
_pam_log(LOG_ERR,
MODULE_NAME ": filename not /rooted or too long; ",
*argv);
RETURN_ERROR( PAM_AUTH_ERR );
}
while ( ( *to++ = *from++ ) );
}
else if ( ! strncmp( *argv, "deny=", 5 ) ) {
if ( sscanf((*argv)+5,TALLY_FMT,&deny) != 1 ) {
_pam_log(LOG_ERR,"bad number supplied; %s",*argv);
RETURN_ERROR( PAM_AUTH_ERR );
}
}
else if ( ! strcmp( *argv, "onerr=fail" ) ) {
fail_on_error=TRUE;
}
else if ( ! strcmp( *argv, "onerr=succeed" ) ) {
fail_on_error=FALSE;
}
else {
_pam_log(LOG_ERR, MODULE_NAME ": unknown option; %s",*argv);
}
} /* for() */
}
{
FILE *TALLY=0;
int i=pam_get_uid(pamh, &uid, &user);
if ( i != PAM_SUCCESS ) RETURN_ERROR( i );
i=get_tally( &tally, uid, filename, &TALLY );
if ( i != PAM_SUCCESS ) { if (TALLY) fclose(TALLY); RETURN_ERROR( i ); }
if ( no_magic_root || getuid() ) { /* no_magic_root kills uid test */
/* To deny or not to deny; that is the question */
if (
( deny != 0 ) && /* deny==0 means no deny */
( tally > deny ) && /* tally>deny means exceeded */
( even_deny_root_account || uid ) /* even_deny stops uid check */
) {
_pam_log(LOG_NOTICE,"user %s ("UID_FMT") tally "TALLY_FMT", deny "TALLY_FMT,
user, uid, tally, deny);
return PAM_AUTH_ERR; /* Only unconditional failure */
}
/* resets for explicit reset
* or by default if deny exists and not magic-root
*/
if ( ( reset == TALLY_RESET_RESET ) ||
( reset == TALLY_RESET_DEFAULT && deny ) ) { tally=0; }
}
else /* is magic root */ {
/* Magic root skips deny test... */
/* Magic root only resets on explicit reset, regardless of deny */
if ( reset == TALLY_RESET_RESET ) { tally=0; }
}
i=set_tally( tally, uid, filename, &TALLY );
if ( i != PAM_SUCCESS ) { if (TALLY) fclose(TALLY); RETURN_ERROR( i ); }
}
return PAM_SUCCESS;
}
#endif /* #ifdef PAM_SM_AUTH */
/*-----------------------------------------------------------------------*/
#ifdef PAM_STATIC
/* static module data */
struct pam_module _pam_tally_modstruct = {
MODULE_NAME,
#ifdef PAM_SM_AUTH
pam_sm_authenticate,
pam_sm_setcred,
#else
NULL,
NULL,
#endif
#ifdef PAM_SM_ACCOUNT
pam_sm_acct_mgmt,
#else
NULL,
#endif
#ifdef PAM_SM_SESSION
pam_sm_open_session,
pam_sm_close_session,
#else
NULL,
NULL,
#endif
#ifdef PAM_SM_PASSWORD
pam_sm_chauthtok,
#else
NULL,
#endif
};
#endif /* #ifdef PAM_STATIC */
/*-----------------------------------------------------------------------*/
#else /* #ifndef MAIN */
static const char *cline_filename = DEFAULT_LOGFILE;
static tally_t cline_reset = TALLY_HI; /* Default is `interrogate only' */
static int cline_quiet = 0;
/*
* Not going to link with pamlib just for these.. :)
*/
static const char * pam_errors( int i ) {
switch (i) {
case PAM_AUTH_ERR: return "Authentication error";
case PAM_SERVICE_ERR: return "Service error";
case PAM_USER_UNKNOWN: return "Unknown user";
default: return "Unknown error";
}
}
static int getopts( int argc, char **argv ) {
const char *pname = *argv;
for ( ; *argv ; (void)(*argv && ++argv) ) {
if ( !strcmp (*argv,"--file") ) cline_filename=*++argv;
else if ( !strncmp(*argv,"--file=",7) ) cline_filename=*argv+7;
else if ( !strcmp (*argv,"--user") ) cline_user=*++argv;
else if ( !strncmp(*argv,"--user=",7) ) cline_user=*argv+7;
else if ( !strcmp (*argv,"--reset") ) cline_reset=0;
else if ( !strncmp(*argv,"--reset=",8)) {
if ( sscanf(*argv+8,TALLY_FMT,&cline_reset) != 1 )
fprintf(stderr,"%s: Bad number given to --reset=\n",pname), exit(0);
}
else if ( !strcmp (*argv,"--quiet") ) cline_quiet=1;
else {
fprintf(stderr,"%s: Unrecognised option %s\n",pname,*argv);
return FALSE;
}
}
return TRUE;
}
int main ( int argc, char **argv ) {
if ( ! getopts( argc, argv+1 ) ) {
printf("%s: [--file rooted-filename] [--user username] "
"[--reset[=n]] [--quiet]\n",
*argv);
exit(0);
}
/*
* Major difference between individual user and all users:
* --user just handles one user, just like PAM.
* --user=* handles all users, sniffing cline_filename for nonzeros
*/
if ( cline_user ) {
uid_t uid;
tally_t tally=cline_reset;
FILE *TALLY=0;
int i=pam_get_uid( NULL, &uid, NULL);
if ( i != PAM_SUCCESS ) {
fprintf(stderr,"%s: %s\n",*argv,pam_errors(i));
exit(0);
}
i=get_tally( &tally, uid, cline_filename, &TALLY );
if ( i != PAM_SUCCESS ) {
if (TALLY) fclose(TALLY);
fprintf(stderr,"%s: %s\n",*argv,pam_errors(i));
exit(0);
}
if ( !cline_quiet )
printf("User %s\t("UID_FMT")\t%s "TALLY_FMT"\n",cline_user,uid,
(cline_reset!=TALLY_HI)?"had":"has",tally);
i=set_tally( cline_reset, uid, cline_filename, &TALLY );
if ( i != PAM_SUCCESS ) {
if (TALLY) fclose(TALLY);
fprintf(stderr,"%s: %s\n",*argv,pam_errors(i));
exit(0);
}
}
else /* !cline_user (ie, operate on all users) */ {
FILE *TALLY=fopen(cline_filename, "r");
uid_t uid=0;
if ( !TALLY ) perror(*argv), exit(0);
for ( ; !feof(TALLY); uid++ ) {
tally_t tally;
struct passwd *pw;
if ( ! fread(&tally, sizeof(tally_t), 1, TALLY) || ! tally ) continue;
if ( ( pw=getpwuid(uid) ) ) {
printf("User %s\t("UID_FMT")\t%s "TALLY_FMT"\n",pw->pw_name,uid,
(cline_reset!=TALLY_HI)?"had":"has",tally);
}
else {
printf("User [NONAME]\t("UID_FMT")\t%s "TALLY_FMT"\n",uid,
(cline_reset!=TALLY_HI)?"had":"has",tally);
}
}
fclose(TALLY);
if ( cline_reset!=0 && cline_reset!=TALLY_HI ) {
fprintf(stderr,"%s: Can't reset all users to non-zero\n",*argv);
}
else if ( !cline_reset ) {
TALLY=fopen(cline_filename, "w");
if ( !TALLY ) perror(*argv), exit(0);
fclose(TALLY);
}
}
return 0;
}
#endif
|