/* Copyright 1988,1990,1993,1994 by Paul Vixie

/* $NetBSD: crontab.c,v 1.15 2018/03/06 21:21:27 htodd Exp $ */

/* Copyright 1988,1990,1993,1994 by Paul Vixie
* All rights reserved
*/

/*
* Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
* Copyright (c) 1997,2000 by Internet Software Consortium, Inc.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
* OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/cdefs.h>
#if !defined(lint) && !defined(LINT)
#if 0
static char rcsid[] = "Id: crontab.c,v 1.12 2004/01/23 18:56:42 vixie Exp";
#else
__RCSID("$NetBSD: crontab.c,v 1.15 2018/03/06 21:21:27 htodd Exp $");
#endif
#endif

/* crontab - install and manage per-user crontab files
* vix 02may87 [RCS has the rest of the log]
* vix 26jan87 [original]
*/

#define MAIN_PROGRAM

#include "cron.h"

#define NHEADER_LINES 3

enum opt_t { opt_unknown, opt_list, opt_delete, opt_edit, opt_replace };

#if DEBUGGING
static const char *Options[] = {
"???", "list", "delete", "edit", "replace" };
static const char *getoptargs = "u:lerx:";
#else
static const char *getoptargs = "u:ler";
#endif

static PID_T Pid;
static char User[MAX_UNAME], RealUser[MAX_UNAME];
static char Filename[MAX_FNAME], TempFilename[MAX_FNAME];
static FILE *NewCrontab;
static int CheckErrorCount;
static enum opt_t Option;
static struct passwd *pw;
static void list_cmd(void),
delete_cmd(void),
edit_cmd(void),
poke_daemon(void),
check_error(const char *),
parse_args(int c, char *v[]);
static int replace_cmd(void);
static int allowed(const char *, const char *, const char *);
static int in_file(const char *, FILE *, int);
static int relinquish_priv(void);
static int regain_priv(void);

static __dead void
usage(const char *msg) {
(void)fprintf(stderr, "%s: usage error: %s\n", getprogname(), msg);
(void)fprintf(stderr, "usage:\t%s [-u user] file\n", getprogname());
(void)fprintf(stderr, "\t%s [-u user] [ -e | -l | -r ]\n", getprogname());
(void)fprintf(stderr, "\t\t(default operation is replace, per 1003.2)\n");
(void)fprintf(stderr, "\t-e\t(edit user's crontab)\n");
(void)fprintf(stderr, "\t-l\t(list user's crontab)\n");
(void)fprintf(stderr, "\t-r\t(delete user's crontab)\n");
exit(ERROR_EXIT);
}

static uid_t euid, ruid;
static gid_t egid, rgid;

int
main(int argc, char *argv[]) {
int exitstatus;

setprogname(argv[0]);
Pid = getpid();
(void)setlocale(LC_ALL, "");

euid = geteuid();
egid = getegid();
ruid = getuid();
rgid = getgid();

if (euid == ruid && ruid != 0)
errx(ERROR_EXIT, "Not installed setuid root");

(void)setvbuf(stderr, NULL, _IOLBF, 0);
parse_args(argc, argv); /* sets many globals, opens a file */
set_cron_cwd();
if (!allowed(RealUser, CRON_ALLOW, CRON_DENY)) {
(void)fprintf(stderr,
"You `%s' are not allowed to use this program `%s'\n",
User, getprogname());
(void)fprintf(stderr, "See crontab(1) for more information\n");
log_it(RealUser, Pid, "AUTH", "crontab command not allowed");
exit(ERROR_EXIT);
}
exitstatus = OK_EXIT;
switch (Option) {
case opt_unknown:
usage("unrecognized option");
exitstatus = ERROR_EXIT;
break;
case opt_list:
list_cmd();
break;
case opt_delete:
delete_cmd();
break;
case opt_edit:
edit_cmd();
break;
case opt_replace:
if (replace_cmd() < 0)
exitstatus = ERROR_EXIT;
break;
default:
abort();
}
exit(exitstatus);
/*NOTREACHED*/
}

static void
get_time(const struct stat *st, struct timespec *ts)
{
ts[0].tv_sec = st->st_atime;
ts[0].tv_nsec = st->st_atimensec;
ts[1].tv_sec = st->st_mtime;
ts[1].tv_nsec = st->st_mtimensec;
}

static int
change_time(const char *name, const struct timespec *ts)
{
#if defined(HAVE_UTIMENSAT)
return utimensat(AT_FDCWD, name, ts, 0);
#elif defined(HAVE_UTIMES)
struct timeval tv[2];
TIMESPEC_TO_TIMEVAL(&tv[0], &ts[0]);
TIMESPEC_TO_TIMEVAL(&tv[1], &ts[1]);
return utimes(name, tv);
#else
struct utimbuf ut;
ut.actime = ts[0].tv_sec;
ut.modtime = ts[1].tv_sec;
return utime(name, &ut);
#endif
}

static int
compare_time(const struct stat *st, const struct timespec *ts2)
{
struct timespec ts1[2];
get_time(st, ts1);

return ts1[1].tv_sec == ts2[1].tv_sec
#if defined(HAVE_UTIMENSAT)
&& ts1[1].tv_nsec == ts2[1].tv_nsec
#elif defined(HAVE_UTIMES)
&& ts1[1].tv_nsec / 1000 == ts2[1].tv_nsec / 1000
#endif
;
}

static void
parse_args(int argc, char *argv[]) {
int argch;

if (!(pw = getpwuid(getuid()))) {
errx(ERROR_EXIT,
"your UID isn't in the passwd file. bailingo out");
}
if (strlen(pw->pw_name) >= sizeof User) {
errx(ERROR_EXIT, "username too long");
}
(void)strlcpy(User, pw->pw_name, sizeof(User));
(void)strlcpy(RealUser, User, sizeof(RealUser));
Filename[0] = '\0';
Option = opt_unknown;
while (-1 != (argch = getopt(argc, argv, getoptargs))) {
switch (argch) {
#if DEBUGGING
case 'x':
if (!set_debug_flags(optarg))
usage("bad debug option");
break;
#endif
case 'u':
if (MY_UID(pw) != ROOT_UID) {
errx(ERROR_EXIT,
"must be privileged to use -u");
}
if (!(pw = getpwnam(optarg))) {
errx(ERROR_EXIT, "user `%s' unknown", optarg);
}
if (strlen(optarg) >= sizeof User)
usage("username too long");
(void) strlcpy(User, optarg, sizeof(User));
break;
case 'l':
if (Option != opt_unknown)
usage("only one operation permitted");
Option = opt_list;
break;
case 'r':
if (Option != opt_unknown)
usage("only one operation permitted");
Option = opt_delete;
break;
case 'e':
if (Option != opt_unknown)
usage("only one operation permitted");
Option = opt_edit;
break;
default:
usage("unrecognized option");
}
}

endpwent();

if (Option != opt_unknown) {
if (argv[optind] != NULL)
usage("no arguments permitted after this option");
} else {
if (argv[optind] != NULL) {
Option = opt_replace;
if (strlen(argv[optind]) >= sizeof Filename)
usage("filename too long");
(void)strlcpy(Filename, argv[optind], sizeof(Filename));
} else
usage("file name must be specified for replace");
}

if (Option == opt_replace) {
/* we have to open the file here because we're going to
* chdir(2) into /var/cron before we get around to
* reading the file.
*/
if (!strcmp(Filename, "-"))
NewCrontab = stdin;
else {
/* relinquish the setuid status of the binary during
* the open, lest nonroot users read files they should
* not be able to read. we can't use access() here
* since there's a race condition. thanks go out to
* Arnt Gulbrandsen <[email protected]> for spotting
* the race.
*/

if (relinquish_priv() < OK) {
err(ERROR_EXIT, "swapping uids");
}
if (!(NewCrontab = fopen(Filename, "r"))) {
err(ERROR_EXIT, "cannot open `%s'", Filename);
}
if (regain_priv() < OK) {
err(ERROR_EXIT, "swapping uids back");
}
}
}

Debug(DMISC, ("user=%s, file=%s, option=%s\n",
User, Filename, Options[(int)Option]));
}

static void
skip_header(int *pch, FILE *f)
{
int ch;
int x;

/* ignore the top few comments since we probably put them there.
*/
for (x = 0; x < NHEADER_LINES; x++) {
ch = get_char(f);
if (EOF == ch)
break;
if ('#' != ch)
break;
while (EOF != (ch = get_char(f)))
if (ch == '\n')
break;
if (EOF == ch)
break;
}
if (ch == '\n')
ch = get_char(f);

*pch = ch;
}

static void
list_cmd(void) {
char n[MAX_FNAME];
FILE *f;
int ch;

log_it(RealUser, Pid, "LIST", User);
if (!glue_strings(n, sizeof n, SPOOL_DIR, User, '/')) {
errx(ERROR_EXIT, "path too long");
}
if (!(f = fopen(n, "r"))) {
if (errno == ENOENT)
errx(ERROR_EXIT, "no crontab for `%s'", User);
else
err(ERROR_EXIT, "Cannot open `%s'", n);
}

/* file is open. copy to stdout, close.
*/
Set_LineNum(1);
skip_header(&ch, f);
for (; EOF != ch; ch = get_char(f))
(void)putchar(ch);
(void)fclose(f);
}

static void
delete_cmd(void) {
char n[MAX_FNAME];

log_it(RealUser, Pid, "DELETE", User);
if (!glue_strings(n, sizeof n, SPOOL_DIR, User, '/')) {
errx(ERROR_EXIT, "path too long");
}
if (unlink(n) != 0) {
if (errno == ENOENT)
errx(ERROR_EXIT, "no crontab for `%s'", User);
else
err(ERROR_EXIT, "cannot unlink `%s'", n);
}
poke_daemon();
}

static void
check_error(const char *msg) {
CheckErrorCount++;
(void)fprintf(stderr, "\"%s\":%d: %s\n", Filename, LineNumber-1, msg);
}

static void
edit_cmd(void) {
char n[MAX_FNAME], q[MAX_TEMPSTR];
const char *editor;
FILE *f;
int ch, t, x;
sig_t oint, oabrt, oquit, ohup;
struct stat statbuf;
WAIT_T waiter;
PID_T pid, xpid;
struct timespec ts[2];

log_it(RealUser, Pid, "BEGIN EDIT", User);
if (!glue_strings(n, sizeof n, SPOOL_DIR, User, '/')) {
errx(ERROR_EXIT, "path too long");
}
if (!(f = fopen(n, "r"))) {
if (errno != ENOENT) {
err(ERROR_EXIT, "cannot open `%s'", n);
}
warnx("no crontab for `%s' - using an empty one", User);
if (!(f = fopen(_PATH_DEVNULL, "r"))) {
err(ERROR_EXIT, "cannot open `%s'", _PATH_DEVNULL);
}
}

if (fstat(fileno(f), &statbuf) < 0) {
warn("cannot stat crontab file");
goto fatal;
}
get_time(&statbuf, ts);

/* Turn off signals. */
ohup = signal(SIGHUP, SIG_IGN);
oint = signal(SIGINT, SIG_IGN);
oquit = signal(SIGQUIT, SIG_IGN);
oabrt = signal(SIGABRT, SIG_IGN);

if (!glue_strings(Filename, sizeof Filename, _PATH_TMP,
"crontab.XXXXXXXXXX", '/')) {
warnx("path too long");
goto fatal;
}
if (-1 == (t = mkstemp(Filename))) {
warn("cannot create `%s'", Filename);
goto fatal;
}
#ifdef HAS_FCHOWN
x = fchown(t, MY_UID(pw), MY_GID(pw));
#else
x = chown(Filename, MY_UID(pw), MY_GID(pw));
#endif
if (x < 0) {
warn("cannot chown `%s'", Filename);
goto fatal;
}
if (!(NewCrontab = fdopen(t, "r+"))) {
warn("cannot open fd");
goto fatal;
}

Set_LineNum(1);

skip_header(&ch, f);

/* copy the rest of the crontab (if any) to the temp file.
*/
for (; EOF != ch; ch = get_char(f))
(void)putc(ch, NewCrontab);
(void)fclose(f);
if (fflush(NewCrontab) < OK) {
err(ERROR_EXIT, "cannot flush output for `%s'", Filename);
}
#ifdef HAVE_FUTIMENS
if (futimens(t, ts) == -1)
#else
if (change_time(Filename, ts) == -1)
#endif
err(ERROR_EXIT, "cannot set time info for `%s'", Filename);
again:
rewind(NewCrontab);
if (ferror(NewCrontab)) {
warn("error while writing new crontab to `%s'", Filename);
fatal:
(void)unlink(Filename);
exit(ERROR_EXIT);
}

if (((editor = getenv("VISUAL")) == NULL || *editor == '\0') &&
((editor = getenv("EDITOR")) == NULL || *editor == '\0')) {
editor = EDITOR;
}

/* we still have the file open. editors will generally rewrite the
* original file rather than renaming/unlinking it and starting a
* new one; even backup files are supposed to be made by copying
* rather than by renaming. if some editor does not support this,
* then don't use it. the security problems are more severe if we
* close and reopen the file around the edit.
*/

switch (pid = fork()) {
case -1:
warn("cannot fork");
goto fatal;
case 0:
/* child */
if (setgid(MY_GID(pw)) < 0) {
err(ERROR_EXIT, "cannot setgid(getgid())");
}
if (setuid(MY_UID(pw)) < 0) {
err(ERROR_EXIT, "cannot setuid(getuid())");
}
if (close_all(3)) {
err(ERROR_EXIT, "cannot close files");
}
if (chdir(_PATH_TMP) < 0) {
err(ERROR_EXIT, "cannot chdir to `%s'", _PATH_TMP);
}
if (!glue_strings(q, sizeof q, editor, Filename, ' ')) {
errx(ERROR_EXIT, "editor command line too long");
}
(void)execlp(_PATH_BSHELL, _PATH_BSHELL, "-c", q, (char *)0);
err(ERROR_EXIT, "cannot start `%s'", editor);
/*NOTREACHED*/
default:
/* parent */
break;
}

/* parent */
for (;;) {
xpid = waitpid(pid, &waiter, WUNTRACED);
if (xpid == -1) {
if (errno != EINTR)
warn("waitpid() failed waiting for PID %ld "
"from `%s'", (long)pid, editor);
} else if (xpid != pid) {
warnx("wrong PID (%ld != %ld) from `%s'",
(long)xpid, (long)pid, editor);
goto fatal;
} else if (WIFSTOPPED(waiter)) {
(void)kill(getpid(), WSTOPSIG(waiter));
} else if (WIFEXITED(waiter) && WEXITSTATUS(waiter)) {
warnx("`%s' exited with status %d\n",
editor, WEXITSTATUS(waiter));
goto fatal;
} else if (WIFSIGNALED(waiter)) {
warnx("`%s' killed; signal %d (%score dumped)",
editor, WTERMSIG(waiter),
WCOREDUMP(waiter) ? "" : "no ");
goto fatal;
} else
break;
}
(void)signal(SIGHUP, ohup);
(void)signal(SIGINT, oint);
(void)signal(SIGQUIT, oquit);
(void)signal(SIGABRT, oabrt);

if (fstat(t, &statbuf) < 0) {
warn("cannot stat `%s'", Filename);
goto fatal;
}
if (compare_time(&statbuf, ts)) {
warnx("no changes made to crontab");
goto remove;
}
warnx("installing new crontab");
switch (replace_cmd()) {
case 0:
break;
case -1:
for (;;) {
(void)fpurge(stdin);
(void)printf("Do you want to retry the same edit? ");
(void)fflush(stdout);
q[0] = '\0';
(void) fgets(q, (int)sizeof(q), stdin);
switch (q[0]) {
case 'y':
case 'Y':
goto again;
case 'n':
case 'N':
goto abandon;
default:
(void)printf("Enter Y or N\n");
}
}
/*NOTREACHED*/
case -2:
abandon:
warnx("edits left in `%s'", Filename);
goto done;
default:
warnx("panic: bad switch() in replace_cmd()");
goto fatal;
}
remove:
(void)unlink(Filename);
done:
log_it(RealUser, Pid, "END EDIT", User);
}

static size_t
getmaxtabsize(void)
{
char n2[MAX_FNAME];
FILE *fmaxtabsize;
size_t maxtabsize;

/* Make sure that the crontab is not an unreasonable size.
*
* XXX This is subject to a race condition--the user could
* add stuff to the file after we've checked the size but
* before we slurp it in and write it out. We can't just move
* the test to test the temp file we later create, because by
* that time we've already filled up the crontab disk. Probably
* the right thing to do is to do a bytecount in the copy loop
* rather than stating the file we're about to read.
*/
(void)snprintf(n2, sizeof(n2), "%s/%s", CRONDIR, MAXTABSIZE_FILE);
if ((fmaxtabsize = fopen(n2, "r")) != NULL) {
if (fgets(n2, (int)sizeof(n2), fmaxtabsize) == NULL) {
maxtabsize = 0;
} else {
maxtabsize = (size_t)atoi(n2);
}
(void)fclose(fmaxtabsize);
} else {
maxtabsize = MAXTABSIZE_DEFAULT;
}
return maxtabsize;
}

static int
checkmaxtabsize(FILE *fp, size_t maxtabsize)
{
struct stat statbuf;

if (fstat(fileno(fp), &statbuf)) {
warn("error stat'ing crontab input");
return 0;
}
if ((uintmax_t)statbuf.st_size > (uintmax_t)maxtabsize) {
warnx("%ju bytes is larger than the maximum size of %ju bytes",
(uintmax_t)statbuf.st_size, (uintmax_t)maxtabsize);
return 0;
}
return 1;
}

static void
cleanTempFile(void)
{

if (TempFilename[0]) {
(void) unlink(TempFilename);
TempFilename[0] = '\0';
}
}

static __dead void
bail(int signo)
{

cleanTempFile();
errx(ERROR_EXIT, "Exiting on signal %d", signo);
}

/* returns 0 on success
* -1 on syntax error
* -2 on install error
*/
static int
replace_cmd(void) {
char n[MAX_FNAME], envstr[MAX_ENVSTR];
int lastch;
FILE *tmp = NULL;
int ch, eof, fd;
int error = 0;
entry *e;
sig_t oint, oabrt, oquit, ohup;
uid_t file_owner;
time_t now = time(NULL);
char **envp = env_init();
size_t i, maxtabsize;

if (envp == NULL) {
warn("Cannot allocate memory.");
return (-2);
}

if (!glue_strings(TempFilename, sizeof TempFilename, SPOOL_DIR,
"tmp.XXXXXXXXXX", '/')) {
TempFilename[0] = '\0';
warnx("path too long");
return (-2);
}

/* Interruptible while doing I/O */
ohup = signal(SIGHUP, bail);
oint = signal(SIGINT, bail);
oquit = signal(SIGQUIT, bail);
oabrt = signal(SIGABRT, bail);

if ((fd = mkstemp(TempFilename)) == -1 || !(tmp = fdopen(fd, "w+"))) {
warn("cannot create `%s'", TempFilename);
if (fd != -1)
(void)close(fd);
error = -2;
goto done;
}

maxtabsize = getmaxtabsize();

/* This does not work for stdin, so we'll also check later */
if (!checkmaxtabsize(NewCrontab, maxtabsize)) {
error = -2;
goto done;
}

/* write a signature at the top of the file.
*
* VERY IMPORTANT: make sure NHEADER_LINES agrees with this code.
*/
(void)fprintf(tmp,
"# DO NOT EDIT THIS FILE - edit the master and reinstall.\n");
(void)fprintf(tmp,
"# (%s installed on %-24.24s)\n", Filename, ctime(&now));
(void)fprintf(tmp,
"# (Cron version %s -- %s)\n", CRON_VERSION,
"$NetBSD: crontab.c,v 1.15 2018/03/06 21:21:27 htodd Exp $");

/* copy the crontab to the tmp
*/
(void)rewind(NewCrontab);
Set_LineNum(1);
lastch = EOF;
for (i = 0; i < maxtabsize && EOF != (ch = get_char(NewCrontab)); i++)
(void)putc(lastch = (char)ch, tmp);

/* Non-Interruptible while installing */
(void)signal(SIGHUP, SIG_IGN);
(void)signal(SIGINT, SIG_IGN);
(void)signal(SIGQUIT, SIG_IGN);
(void)signal(SIGABRT, SIG_IGN);

if (i == maxtabsize) {
warnx("is larger than the maximum size of %ju bytes",
(uintmax_t)maxtabsize);
error = -2;
goto done;
}

if (lastch != EOF && lastch != '\n') {
warnx("missing trailing newline in `%s'", Filename);
error = -1;
goto done;
}

if (ferror(NewCrontab)) {
warn("error while reading `%s'", Filename);
error = -2;
goto done;
}

(void)ftruncate(fileno(tmp), ftell(tmp));
/* XXX this should be a NOOP - is */
(void)fflush(tmp);

if (ferror(tmp)) {
warn("error while writing new crontab to `%s'", TempFilename);
error = -2;
goto done;
}

/* check the syntax of the file being installed.
*/

/* BUG: was reporting errors after the EOF if there were any errors
* in the file proper -- kludged it by stopping after first error.
* vix 31mar87
*/
Set_LineNum(1 - NHEADER_LINES);
CheckErrorCount = 0; eof = FALSE;
rewind(tmp);
while (!CheckErrorCount && !eof) {
switch (load_env(envstr, tmp)) {
case ERR:
/* check for data before the EOF */
if (envstr[0] != '\0') {
Set_LineNum(LineNumber + 1);
check_error("premature EOF");
}
eof = TRUE;
break;
case FALSE:
e = load_entry(tmp, check_error, pw, envp);
if (e)
free(e);
break;
case TRUE:
break;
}
}

if (CheckErrorCount != 0) {
warnx("errors in crontab file, can't install.");
error = -1;
goto done;
}

file_owner = (getgid() == getegid()) ? ROOT_UID : pw->pw_uid;

#ifdef HAVE_FCHOWN
error = fchown(fileno(tmp), file_owner, (uid_t)-1);
#else
error = chown(TempFilename, file_owner, (gid_t)-1);
#endif

if (fclose(tmp) == EOF) {
warn("error closing file");
error = -2;
tmp = NULL;
goto done;
}
tmp = NULL;

if (error < OK) {
warn("cannot chown `%s'", TempFilename);
error = -2;
goto done;
}

if (!glue_strings(n, sizeof n, SPOOL_DIR, User, '/')) {
warnx("path too long");
error = -2;
goto done;
}
if (rename(TempFilename, n)) {
warn("error renaming `%s' to `%s'", TempFilename, n);
error = -2;
goto done;
}
TempFilename[0] = '\0';
log_it(RealUser, Pid, "REPLACE", User);

poke_daemon();

done:
(void)signal(SIGHUP, ohup);
(void)signal(SIGINT, oint);
(void)signal(SIGQUIT, oquit);
(void)signal(SIGABRT, oabrt);
if (tmp != NULL)
(void)fclose(tmp);
cleanTempFile();
return (error);
}

static void
poke_daemon(void) {
struct timespec ts[2];
(void) clock_gettime(CLOCK_REALTIME, ts);
ts[1] = ts[0];
if (change_time(SPOOL_DIR, ts) == -1)
warn("can't update times on spooldir %s", SPOOL_DIR);
}

/* int allowed(const char *username, const char *allow_file, const char *deny_file)
* returns TRUE if (allow_file exists and user is listed)
* or (deny_file exists and user is NOT listed).
* root is always allowed.
*/
static int
allowed(const char *username, const char *allow_file, const char *deny_file) {
FILE *fp;
int isallowed;

if (strcmp(username, ROOT_USER) == 0)
return (TRUE);
#ifdef ALLOW_ONLY_ROOT
isallowed = FALSE;
#else
isallowed = TRUE;
#endif
if ((fp = fopen(allow_file, "r")) != NULL) {
isallowed = in_file(username, fp, FALSE);
(void)fclose(fp);
} else if ((fp = fopen(deny_file, "r")) != NULL) {
isallowed = !in_file(username, fp, FALSE);
(void)fclose(fp);
}
return (isallowed);
}
/* int in_file(const char *string, FILE *file, int error)
* return TRUE if one of the lines in file matches string exactly,
* FALSE if no lines match, and error on error.
*/
static int
in_file(const char *string, FILE *file, int error)
{
char line[MAX_TEMPSTR];
char *endp;

if (fseek(file, 0L, SEEK_SET))
return (error);
while (fgets(line, MAX_TEMPSTR, file)) {
if (line[0] != '\0') {
endp = &line[strlen(line) - 1];
if (*endp != '\n')
return (error);
*endp = '\0';
if (0 == strcmp(line, string))
return (TRUE);
}
}
if (ferror(file))
return (error);
return (FALSE);
}

#ifdef HAVE_SAVED_UIDS

static int relinquish_priv(void) {
return (setegid(rgid) || seteuid(ruid)) ? -1 : 0;
}

static int regain_priv(void) {
return (setegid(egid) || seteuid(euid)) ? -1 : 0;
}

#else /*HAVE_SAVED_UIDS*/

static int relinquish_priv(void) {
return (setregid(egid, rgid) || setreuid(euid, ruid)) ? -1 : 0;
}

static int regain_priv(void) {
return (setregid(rgid, egid) || setreuid(ruid, euid)) ? -1 : 0;
}
#endif /*HAVE_SAVED_UIDS*/