cronie/src/crontab.c

972 lines
23 KiB
C
Raw Normal View History

2017-05-08 15:30:03 +02:00
/* 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.
*/
/* crontab - install and manage per-user crontab files
* vix 02may87 [RCS has the rest of the log]
* vix 26jan87 [original]
*/
/*
* Modified 2010/09/10 by Colin Dean, Durham University IT Service,
* to add clustering support.
*/
#define MAIN_PROGRAM
#include <cron.h>
#ifdef WITH_SELINUX
# include <selinux/selinux.h>
# include <selinux/context.h>
# include <selinux/av_permissions.h>
#endif
#define NHEADER_LINES 0
enum opt_t {opt_unknown, opt_list, opt_delete, opt_edit, opt_replace, opt_hostset, opt_hostget};
#if DEBUGGING
static char *Options[] = {"???", "list", "delete", "edit", "replace", "hostset", "hostget"};
# ifdef WITH_SELINUX
static char *getoptargs = "u:lerisncx:";
# else
static char *getoptargs = "u:lerincx:";
# endif
#else
# ifdef WITH_SELINUX
static char *getoptargs = "u:lerisnc";
# else
static char *getoptargs = "u:lerinc";
# endif
#endif
static char *selinux_context = 0;
static PID_T Pid;
static char User[MAX_UNAME], RealUser[MAX_UNAME];
static char Filename[MAX_FNAME], TempFilename[MAX_FNAME];
static char Host[MAXHOSTNAMELEN];
static FILE *NewCrontab;
static int CheckErrorCount;
static int PromptOnDelete;
static int HostSpecified;
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[]), die(int);
static int replace_cmd(void), hostset_cmd(void), hostget_cmd(void);
static char *host_specific_filename(char *filename, int prefix);
static char *tmp_path(void);
static void usage(const char *msg) {
fprintf(stderr, "%s: usage error: %s\n", ProgramName, msg);
fprintf(stderr, "usage:\t%s [-u user] file\n", ProgramName);
fprintf(stderr, "\t%s [-u user] [ -e | -l | -r ]\n", ProgramName);
fprintf(stderr, "\t%s -n [ hostname ]\n", ProgramName);
fprintf(stderr, "\t%s -c\n", ProgramName);
fprintf(stderr, "\t\t(default operation is replace, per 1003.2)\n");
fprintf(stderr, "\t-e\t(edit user's crontab)\n");
fprintf(stderr, "\t-l\t(list user's crontab)\n");
fprintf(stderr, "\t-r\t(delete user's crontab)\n");
fprintf(stderr, "\t-i\t(prompt before deleting user's crontab)\n");
fprintf(stderr, "\t-n\t(set host in cluster to run users' crontabs)\n");
fprintf(stderr, "\t-c\t(get host in cluster to run users' crontabs)\n");
#ifdef WITH_SELINUX
fprintf(stderr, "\t-s\t(selinux context)\n");
#endif
exit(ERROR_EXIT);
}
int main(int argc, char *argv[]) {
int exitstatus;
Pid = getpid();
ProgramName = argv[0];
MailCmd[0] = '\0';
cron_default_mail_charset[0] = '\0';
setlocale(LC_ALL, "");
#if defined(BSD)
setlinebuf(stderr);
#endif
char *n = "-"; /*set the n string to - so we have a valid string to use */
/*should we desire to make changes to behavior later. */
if (argv[1] == NULL) { /* change behavior to allow crontab to take stdin with no '-' */
argv[1] = n;
}
parse_args(argc, argv); /* sets many globals, opens a file */
check_spool_dir();
if (!allowed(RealUser, CRON_ALLOW, CRON_DENY)) {
fprintf(stderr,
"You (%s) are not allowed to use this program (%s)\n",
User, ProgramName);
fprintf(stderr, "See crontab(1) for more information\n");
log_it(RealUser, Pid, "AUTH", "crontab command not allowed", 0);
exit(ERROR_EXIT);
}
#if defined(WITH_PAM)
if (cron_start_pam(pw) != PAM_SUCCESS) {
fprintf(stderr,
"You (%s) are not allowed to access to (%s) because of pam configuration.\n",
User, ProgramName);
exit(ERROR_EXIT);
};
#endif
exitstatus = OK_EXIT;
switch (Option) {
case opt_unknown:
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;
case opt_hostset:
if (hostset_cmd() < 0)
exitstatus = ERROR_EXIT;
break;
case opt_hostget:
if (hostget_cmd() < 0)
exitstatus = ERROR_EXIT;
break;
default:
abort();
}
cron_close_pam();
exit(exitstatus);
/*NOTREACHED*/}
static void parse_args(int argc, char *argv[]) {
int argch;
if (!(pw = getpwuid(getuid()))) {
fprintf(stderr, "%s: your UID isn't in the passwd file.\n",
ProgramName);
fprintf(stderr, "bailing out.\n");
exit(ERROR_EXIT);
}
if (strlen(pw->pw_name) >= sizeof User) {
fprintf(stderr, "username too long\n");
exit(ERROR_EXIT);
}
strcpy(User, pw->pw_name);
strcpy(RealUser, User);
Filename[0] = '\0';
Option = opt_unknown;
PromptOnDelete = 0;
HostSpecified = 0;
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) {
fprintf(stderr, "must be privileged to use -u\n");
exit(ERROR_EXIT);
}
if (crontab_security_access() != 0) {
fprintf(stderr,
"Access denied by SELinux, must be privileged to use -u\n");
exit(ERROR_EXIT);
}
if (Option == opt_hostset || Option == opt_hostget) {
fprintf(stderr,
"cannot use -u with -n or -c\n");
exit(ERROR_EXIT);
}
if (!(pw = getpwnam(optarg))) {
fprintf(stderr, "%s: user `%s' unknown\n",
ProgramName, optarg);
exit(ERROR_EXIT);
}
if (strlen(optarg) >= sizeof User)
usage("username too long");
(void) strcpy(User, optarg);
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;
case 'i':
PromptOnDelete = 1;
break;
#ifdef WITH_SELINUX
case 's':
if (getprevcon((security_context_t *) & (selinux_context))) {
fprintf(stderr, "Cannot obtain SELinux process context\n");
exit(ERROR_EXIT);
}
break;
#endif
case 'n':
if (MY_UID(pw) != ROOT_UID) {
fprintf(stderr,
"must be privileged to set host with -n\n");
exit(ERROR_EXIT);
}
if (Option != opt_unknown)
usage("only one operation permitted");
if (strcmp(User, RealUser) != 0) {
fprintf(stderr,
"cannot use -u with -n or -c\n");
exit(ERROR_EXIT);
}
Option = opt_hostset;
break;
case 'c':
if (Option != opt_unknown)
usage("only one operation permitted");
if (strcmp(User, RealUser) != 0) {
fprintf(stderr,
"cannot use -u with -n or -c\n");
exit(ERROR_EXIT);
}
Option = opt_hostget;
break;
default:
usage("unrecognized option");
}
}
endpwent();
if (Option == opt_hostset && argv[optind] != NULL) {
HostSpecified = 1;
if (strlen(argv[optind]) >= sizeof Host)
usage("hostname too long");
(void) strcpy(Host, argv[optind]);
optind++;
}
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) strcpy(Filename, argv[optind]);
}
else
usage("file name must be specified for replace");
}
if (Option == opt_replace) {
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 <agulbra@pvv.unit.no> for spotting
* the race.
*/
if (swap_uids() < OK) {
perror("swapping uids");
exit(ERROR_EXIT);
}
if (!(NewCrontab = fopen(Filename, "r"))) {
perror(Filename);
exit(ERROR_EXIT);
}
if (swap_uids_back() < OK) {
perror("swapping uids back");
exit(ERROR_EXIT);
}
}
}
Debug(DMISC, ("user=%s, file=%s, option=%s\n",
User, Filename, Options[(int) Option]))
}
static void list_cmd(void) {
char n[MAX_FNAME];
FILE *f;
int ch;
log_it(RealUser, Pid, "LIST", User, 0);
if (!glue_strings(n, sizeof n, SPOOL_DIR, User, '/')) {
fprintf(stderr, "path too long\n");
exit(ERROR_EXIT);
}
if (!(f = fopen(n, "r"))) {
if (errno == ENOENT)
fprintf(stderr, "no crontab for %s\n", User);
else
perror(n);
exit(ERROR_EXIT);
}
/* file is open. copy to stdout, close.
*/
Set_LineNum(1)
while (EOF != (ch = get_char(f)))
putchar(ch);
fclose(f);
}
static void delete_cmd(void) {
char n[MAX_FNAME] = "";
if (PromptOnDelete == 1) {
printf("crontab: really delete %s's crontab? ", User);
fflush(stdout);
if ((fgets(n, MAX_FNAME - 1, stdin) == 0L)
|| ((n[0] != 'Y') && (n[0] != 'y'))
)
exit(0);
}
log_it(RealUser, Pid, "DELETE", User, 0);
if (!glue_strings(n, sizeof n, SPOOL_DIR, User, '/')) {
fprintf(stderr, "path too long\n");
exit(ERROR_EXIT);
}
if (unlink(n) != 0) {
if (errno == ENOENT)
fprintf(stderr, "no crontab for %s\n", User);
else
perror(n);
exit(ERROR_EXIT);
}
poke_daemon();
}
static void check_error(const char *msg) {
CheckErrorCount++;
fprintf(stderr, "\"%s\":%d: %s\n", Filename, LineNumber - 1, msg);
}
static char *tmp_path() {
char *tmpdir = NULL;
if ((getuid() == geteuid()) && (getgid() == getegid())) {
tmpdir = getenv("TMPDIR");
}
return tmpdir ? tmpdir : "/tmp";
}
static char *host_specific_filename(char *filename, int prefix)
{
/*
* For cluster-wide use, where there is otherwise risk of the same
* name being generated on more than one host at once, prefix with
* "hostname." or suffix with ".hostname" as requested, and return
* static buffer or NULL on failure.
*/
static char safename[MAX_FNAME];
char hostname[MAXHOSTNAMELEN];
if (gethostname(hostname, sizeof hostname) != 0)
return NULL;
if (prefix) {
if (!glue_strings(safename, sizeof safename, hostname, filename, '.'))
return NULL;
} else {
if (!glue_strings(safename, sizeof safename, filename, hostname, '.'))
return NULL;
}
return safename;
}
static void edit_cmd(void) {
char n[MAX_FNAME], q[MAX_TEMPSTR], *editor;
FILE *f;
int ch = '\0', t;
struct stat statbuf;
struct utimbuf utimebuf;
WAIT_T waiter;
PID_T pid, xpid;
log_it(RealUser, Pid, "BEGIN EDIT", User, 0);
if (!glue_strings(n, sizeof n, SPOOL_DIR, User, '/')) {
fprintf(stderr, "path too long\n");
exit(ERROR_EXIT);
}
if (!(f = fopen(n, "r"))) {
if (errno != ENOENT) {
perror(n);
exit(ERROR_EXIT);
}
fprintf(stderr, "no crontab for %s - using an empty one\n", User);
if (!(f = fopen(_PATH_DEVNULL, "r"))) {
perror(_PATH_DEVNULL);
exit(ERROR_EXIT);
}
}
/* Turn off signals. */
(void) signal(SIGHUP, SIG_IGN);
(void) signal(SIGINT, SIG_IGN);
(void) signal(SIGQUIT, SIG_IGN);
if (!glue_strings(Filename, sizeof Filename, tmp_path(),
"crontab.XXXXXX", '/')) {
fprintf(stderr, "path too long\n");
exit(ERROR_EXIT);
}
if (swap_uids() == -1) {
perror("swapping uids");
exit(ERROR_EXIT);
}
if (-1 == (t = mkstemp(Filename))) {
perror(Filename);
goto fatal;
}
if (swap_uids_back() == -1) {
perror("swapping uids back");
goto fatal;
}
if (!(NewCrontab = fdopen(t, "r+"))) {
perror("fdopen");
goto fatal;
}
Set_LineNum(1)
/*
* NHEADER_LINES processing removed for clarity
* (NHEADER_LINES == 0 in all Red Hat crontabs)
*/
/* copy the rest of the crontab (if any) to the temp file.
*/
if (EOF != ch)
while (EOF != (ch = get_char(f)))
putc(ch, NewCrontab);
#ifdef WITH_SELINUX
if (selinux_context) {
context_t ccon = NULL;
const char *level = NULL;
if (!(ccon = context_new(selinux_context))) {
fprintf(stderr, "context_new failed\n");
goto fatal;
}
if (!(level = context_range_get(ccon))) {
fprintf(stderr, "context_range failed\n");
goto fatal;
}
fprintf(NewCrontab, "MLS_LEVEL=%s\n", level);
context_free(ccon);
freecon(selinux_context);
selinux_context = NULL;
}
#endif
fclose(f);
if (fflush(NewCrontab) < OK) {
perror(Filename);
exit(ERROR_EXIT);
}
if (swap_uids() == -1) {
perror("swapping uids");
exit(ERROR_EXIT);
}
/* Set it to 1970 */
utimebuf.actime = 0;
utimebuf.modtime = 0;
utime(Filename, &utimebuf);
if (swap_uids_back() == -1) {
perror("swapping uids");
exit(ERROR_EXIT);
}
again:
rewind(NewCrontab);
if (ferror(NewCrontab)) {
fprintf(stderr, "%s: error while writing new crontab to %s\n",
ProgramName, Filename);
fatal:
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:
perror("fork");
goto fatal;
case 0:
/* child */
if (setgid(MY_GID(pw)) < 0) {
perror("setgid(getgid())");
exit(ERROR_EXIT);
}
if (setuid(MY_UID(pw)) < 0) {
perror("setuid(getuid())");
exit(ERROR_EXIT);
}
if (!glue_strings(q, sizeof q, editor, Filename, ' ')) {
fprintf(stderr, "%s: editor command line too long\n", ProgramName);
exit(ERROR_EXIT);
}
execlp(_PATH_BSHELL, _PATH_BSHELL, "-c", q, (char *) 0);
perror(editor);
exit(ERROR_EXIT);
/*NOTREACHED*/ default:
/* parent */
break;
}
/* parent */
for (;;) {
xpid = waitpid(pid, &waiter, 0);
if (xpid == -1) {
if (errno != EINTR)
fprintf(stderr,
"%s: waitpid() failed waiting for PID %ld from \"%s\": %s\n",
ProgramName, (long) pid, editor, strerror(errno));
}
else if (xpid != pid) {
fprintf(stderr, "%s: wrong PID (%ld != %ld) from \"%s\"\n",
ProgramName, (long) xpid, (long) pid, editor);
goto fatal;
}
else if (WIFEXITED(waiter) && WEXITSTATUS(waiter)) {
fprintf(stderr, "%s: \"%s\" exited with status %d\n",
ProgramName, editor, WEXITSTATUS(waiter));
goto fatal;
}
else if (WIFSIGNALED(waiter)) {
fprintf(stderr,
"%s: \"%s\" killed; signal %d (%score dumped)\n",
ProgramName, editor, WTERMSIG(waiter),
WCOREDUMP(waiter) ? "" : "no ");
goto fatal;
}
else
break;
}
(void) signal(SIGHUP, SIG_DFL);
(void) signal(SIGINT, SIG_DFL);
(void) signal(SIGQUIT, SIG_DFL);
/* lstat doesn't make any harm, because
* the file is stat'ed only when crontab is touched
*/
if (lstat(Filename, &statbuf) < 0) {
perror("lstat");
goto fatal;
}
if (!S_ISREG(statbuf.st_mode)) {
fprintf(stderr, "%s: illegal crontab\n", ProgramName);
goto remove;
}
if (statbuf.st_mtime == 0) {
fprintf(stderr, "%s: no changes made to crontab\n", ProgramName);
goto remove;
}
fprintf(stderr, "%s: installing new crontab\n", ProgramName);
fclose(NewCrontab);
if (swap_uids() < OK) {
perror("swapping uids");
goto remove;
}
if (!(NewCrontab = fopen(Filename, "r+"))) {
perror("cannot read new crontab");
goto remove;
}
if (swap_uids_back() < OK) {
perror("swapping uids back");
exit(ERROR_EXIT);
}
if (NewCrontab == 0L) {
perror("fopen");
goto fatal;
}
switch (replace_cmd()) {
case 0:
break;
case -1:
for (;;) {
printf("Do you want to retry the same edit? ");
fflush(stdout);
q[0] = '\0';
if (fgets(q, sizeof q, stdin) == 0L)
continue;
switch (q[0]) {
case 'y':
case 'Y':
goto again;
case 'n':
case 'N':
goto abandon;
default:
fprintf(stderr, "Enter Y or N\n");
}
}
/*NOTREACHED*/ case -2:
abandon:
fprintf(stderr, "%s: edits left in %s\n", ProgramName, Filename);
goto done;
default:
fprintf(stderr, "%s: panic: bad switch() in replace_cmd()\n",
ProgramName);
goto fatal;
}
remove:
unlink(Filename);
done:
log_it(RealUser, Pid, "END EDIT", User, 0);
}
/* returns 0 on success
* -1 on syntax error
* -2 on install error
*/
static int replace_cmd(void) {
char n[MAX_FNAME], envstr[MAX_ENVSTR];
FILE *tmp;
int ch, eof, fd;
int error = 0;
entry *e;
uid_t file_owner;
char **envp;
char *safename;
safename = host_specific_filename("tmp.XXXXXXXXXX", 1);
if (!safename || !glue_strings(TempFilename, sizeof TempFilename, SPOOL_DIR,
safename, '/')) {
TempFilename[0] = '\0';
fprintf(stderr, "path too long\n");
return (-2);
}
if ((fd = mkstemp(TempFilename)) == -1 || !(tmp = fdopen(fd, "w+"))) {
perror(TempFilename);
if (fd != -1) {
close(fd);
unlink(TempFilename);
}
TempFilename[0] = '\0';
return (-2);
}
(void) signal(SIGHUP, die);
(void) signal(SIGINT, die);
(void) signal(SIGQUIT, die);
/* write a signature at the top of the file.
*
* VERY IMPORTANT: make sure NHEADER_LINES agrees with this code.
*/
/*fprintf(tmp, "# DO NOT EDIT THIS FILE - edit the master and reinstall.\n");
*fprintf(tmp, "# (%s installed on %-24.24s)\n", Filename, ctime(&now));
*fprintf(tmp, "# (Cron version %s)\n", CRON_VERSION);
*/
#ifdef WITH_SELINUX
if (selinux_context)
fprintf(tmp, "SELINUX_ROLE_TYPE=%s\n", selinux_context);
#endif
/* copy the crontab to the tmp
*/
rewind(NewCrontab);
Set_LineNum(1)
while (EOF != (ch = get_char(NewCrontab)))
putc(ch, tmp);
if (ftruncate(fileno(tmp), ftell(tmp)) == -1) {
fprintf(stderr, "%s: error while writing new crontab to %s\n",
ProgramName, TempFilename);
fclose(tmp);
error = -2;
goto done;
}
fflush(tmp);
rewind(tmp);
if (ferror(tmp)) {
fprintf(stderr, "%s: error while writing new crontab to %s\n",
ProgramName, TempFilename);
fclose(tmp);
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;
envp = env_init();
if (envp == NULL) {
fprintf(stderr, "%s: Cannot allocate memory.\n", ProgramName);
fclose(tmp);
error = -2;
goto done;
}
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_entry(e);
break;
case TRUE:
break;
}
}
env_free(envp);
if (CheckErrorCount != 0) {
fprintf(stderr, "errors in crontab file, can't install.\n");
fclose(tmp);
error = -1;
goto done;
}
file_owner = (getgid() == getegid())? ROOT_UID : pw->pw_uid;
#ifdef HAVE_FCHOWN
if (fchown(fileno(tmp), file_owner, -1) < OK) {
perror("fchown");
fclose(tmp);
error = -2;
goto done;
}
#else
if (chown(TempFilename, file_owner, -1) < OK) {
perror("chown");
fclose(tmp);
error = -2;
goto done;
}
#endif
if (fclose(tmp) == EOF) {
perror("fclose");
error = -2;
goto done;
}
if (!glue_strings(n, sizeof n, SPOOL_DIR, User, '/')) {
fprintf(stderr, "path too long\n");
error = -2;
goto done;
}
if (rename(TempFilename, n)) {
fprintf(stderr, "%s: error renaming %s to %s\n",
ProgramName, TempFilename, n);
perror("rename");
error = -2;
goto done;
}
TempFilename[0] = '\0';
log_it(RealUser, Pid, "REPLACE", User, 0);
poke_daemon();
done:
(void) signal(SIGHUP, SIG_DFL);
(void) signal(SIGINT, SIG_DFL);
(void) signal(SIGQUIT, SIG_DFL);
if (TempFilename[0]) {
(void) unlink(TempFilename);
TempFilename[0] = '\0';
}
return (error);
}
static int hostset_cmd(void) {
char n[MAX_FNAME];
FILE *tmp;
int fd;
int error = 0;
char *safename;
if (!HostSpecified)
gethostname(Host, sizeof Host);
safename = host_specific_filename("tmp.XXXXXXXXXX", 1);
if (!safename || !glue_strings(TempFilename, sizeof TempFilename, SPOOL_DIR,
safename, '/')) {
TempFilename[0] = '\0';
fprintf(stderr, "path too long\n");
return (-2);
}
if ((fd = mkstemp(TempFilename)) == -1 || !(tmp = fdopen(fd, "w"))) {
perror(TempFilename);
if (fd != -1) {
close(fd);
unlink(TempFilename);
}
TempFilename[0] = '\0';
return (-2);
}
(void) signal(SIGHUP, die);
(void) signal(SIGINT, die);
(void) signal(SIGQUIT, die);
(void) fchmod(fd, 0600); /* not all mkstemp() implementations do this */
if (fprintf(tmp, "%s\n", Host) < 0 || fclose(tmp) == EOF) {
fprintf(stderr, "%s: error while writing to %s\n",
ProgramName, TempFilename);
error = -2;
goto done;
}
if (!glue_strings(n, sizeof n, SPOOL_DIR, CRON_HOSTNAME, '/')) {
fprintf(stderr, "path too long\n");
error = -2;
goto done;
}
if (rename(TempFilename, n)) {
fprintf(stderr, "%s: error renaming %s to %s\n",
ProgramName, TempFilename, n);
perror("rename");
error = -2;
goto done;
}
TempFilename[0] = '\0';
log_it(RealUser, Pid, "SET HOST", Host, 0);
poke_daemon();
done:
(void) signal(SIGHUP, SIG_DFL);
(void) signal(SIGINT, SIG_DFL);
(void) signal(SIGQUIT, SIG_DFL);
if (TempFilename[0]) {
(void) unlink(TempFilename);
TempFilename[0] = '\0';
}
return (error);
}
static int hostget_cmd(void) {
char n[MAX_FNAME];
FILE *f;
if (!glue_strings(n, sizeof n, SPOOL_DIR, CRON_HOSTNAME, '/')) {
fprintf(stderr, "path too long\n");
return (-2);
}
if (!(f = fopen(n, "r"))) {
if (errno == ENOENT)
fprintf(stderr, "File %s not found\n", n);
else
perror(n);
return (-2);
}
if (get_string(Host, sizeof Host, f, "\n") == EOF) {
fprintf(stderr, "Error reading from %s\n", n);
fclose(f);
return (-2);
}
fclose(f);
printf("%s\n", Host);
fflush(stdout);
log_it(RealUser, Pid, "GET HOST", Host, 0);
return (0);
}
static void poke_daemon(void) {
if (utime(SPOOL_DIR, NULL) < OK) {
fprintf(stderr, "crontab: can't update mtime on spooldir\n");
perror(SPOOL_DIR);
return;
}
}
static void die(int x) {
if (TempFilename[0])
(void) unlink(TempFilename);
_exit(ERROR_EXIT);
}