NetBSD-5.0.2/usr.sbin/cron/misc.c
/* $NetBSD: misc.c,v 1.14 2008/02/16 07:26:00 matt Exp $ */
/* Copyright 1988,1990,1993,1994 by Paul Vixie
* All rights reserved
*
* Distribute freely, except: don't remove my name from the source or
* documentation (don't take credit for my work), mark your changes (don't
* get me blamed for your possible bugs), don't alter or remove this
* notice. May be sold if buildable source is provided to buyer. No
* warrantee of any kind, express or implied, is included with this
* software; use at your own risk, responsibility for damages (if any) to
* anyone resulting from the use of this software rests entirely with the
* user.
*
* Send bug reports, bug fixes, enhancements, requests, flames, etc., and
* I'll try to keep a version up to date. I can be reached as follows:
* Paul Vixie <paul@vix.com> uunet!decwrl!vixie!paul
*/
#include <sys/cdefs.h>
#if !defined(lint) && !defined(LINT)
#if 0
static char rcsid[] = "Id: misc.c,v 2.9 1994/01/15 20:43:43 vixie Exp";
#else
__RCSID("$NetBSD: misc.c,v 1.14 2008/02/16 07:26:00 matt Exp $");
#endif
#endif
/* vix 26jan87 [RCS has the rest of the log]
* vix 30dec86 [written]
*/
#include "cron.h"
#if SYS_TIME_H
# include <sys/time.h>
#else
# include <time.h>
#endif
#include <sys/file.h>
#include <sys/stat.h>
#include <err.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#if defined(SYSLOG)
# include <syslog.h>
#endif
#include <ctype.h>
#include <vis.h>
#if defined(LOG_DAEMON) && !defined(LOG_CRON)
#define LOG_CRON LOG_DAEMON
#endif
static int in_file(char *, FILE *);
static void mkprint(char *, unsigned char *, int);
static int LogFD = ERR;
int
strcmp_until(const char *left, const char *right, int until)
{
int diff;
while (*left && *left != until && *left == *right) {
left++;
right++;
}
if ((*left=='\0' || *left == until) &&
(*right=='\0' || *right == until)) {
diff = 0;
} else {
diff = *left - *right;
}
return diff;
}
/* strdtb(s) - delete trailing blanks in string 's' and return new length
*/
int
strdtb(char *s)
{
char *x = s;
/* scan forward to the null
*/
while (*x)
x++;
/* scan backward to either the first character before the string,
* or the last non-blank in the string, whichever comes first.
*/
do {x--;}
while (x >= s && isspace((unsigned char)*x));
/* one character beyond where we stopped above is where the null
* goes.
*/
*++x = '\0';
/* the difference between the position of the null character and
* the position of the first character of the string is the length.
*/
return x - s;
}
int
set_debug_flags(char *flags)
{
/* debug flags are of the form flag[,flag ...]
*
* if an error occurs, print a message to stdout and return FALSE.
* otherwise return TRUE after setting ERROR_FLAGS.
*/
#if !DEBUGGING
printf("this program was compiled without debugging enabled\n");
return FALSE;
#else /* DEBUGGING */
char *pc = flags;
DebugFlags = 0;
while (*pc) {
const char * const *test;
int mask;
/* try to find debug flag name in our list.
*/
for ( test = DebugFlagNames, mask = 1;
*test && strcmp_until(*test, pc, ',');
test++, mask <<= 1
)
;
if (!*test) {
fprintf(stderr,
"unrecognized debug flag <%s> <%s>\n",
flags, pc);
return FALSE;
}
DebugFlags |= mask;
/* skip to the next flag
*/
while (*pc && *pc != ',')
pc++;
if (*pc == ',')
pc++;
}
if (DebugFlags) {
int flag;
fprintf(stderr, "debug flags enabled:");
for (flag = 0; DebugFlagNames[flag]; flag++)
if (DebugFlags & (1 << flag))
fprintf(stderr, " %s", DebugFlagNames[flag]);
fprintf(stderr, "\n");
}
return TRUE;
#endif /* DEBUGGING */
}
void
set_cron_uid(void)
{
#if defined(BSD) || defined(POSIX)
if (seteuid(ROOT_UID) < OK) {
warn("cannot seteuid");
exit(ERROR_EXIT);
}
#else
if (setuid(ROOT_UID) < OK) {
warn("cannot setuid");
exit(ERROR_EXIT);
}
#endif
}
void
set_cron_cwd(void)
{
struct stat sb;
/* first check for CRONDIR ("/var/cron" or some such)
*/
if (stat(CRONDIR, &sb) < OK && errno == ENOENT) {
warn("cannot stat %s", CRONDIR);
if (OK == mkdir(CRONDIR, 0700)) {
fprintf(stderr, "%s: created\n", CRONDIR);
stat(CRONDIR, &sb);
} else {
warn("cannot create %s", CRONDIR);
exit(ERROR_EXIT);
}
}
if (!S_ISDIR(sb.st_mode)) {
warnx("`%s' is not a directory, bailing out", CRONDIR);
exit(ERROR_EXIT);
}
if (chdir(CRONDIR) < OK) {
warn("cannot chdir(%s), bailing out", CRONDIR);
exit(ERROR_EXIT);
}
/* CRONDIR okay (now==CWD), now look at SPOOL_DIR ("tabs" or some such)
*/
if (stat(SPOOL_DIR, &sb) < OK && errno == ENOENT) {
warn("cannot stat %s", SPOOL_DIR);
if (OK == mkdir(SPOOL_DIR, 0700)) {
fprintf(stderr, "%s: created\n", SPOOL_DIR);
stat(SPOOL_DIR, &sb);
} else {
warn("cannot create %s", SPOOL_DIR);
exit(ERROR_EXIT);
}
}
if (!S_ISDIR(sb.st_mode)) {
fprintf(stderr, "'%s' is not a directory, bailing out.\n",
SPOOL_DIR);
exit(ERROR_EXIT);
}
}
/* acquire_daemonlock() - write our PID into /etc/cron.pid, unless
* another daemon is already running, which we detect here.
*
* note: main() calls us twice; once before forking, once after.
* we maintain static storage of the file pointer so that we
* can rewrite our PID into the PIDFILE after the fork.
*
* it would be great if fflush() disassociated the file buffer.
*/
void
acquire_daemonlock(int closeflag)
{
static FILE *fp = NULL;
if (closeflag && fp) {
fclose(fp);
fp = NULL;
return;
}
if (!fp) {
char pidfile[MAX_FNAME];
char buf[MAX_TEMPSTR];
int fd, otherpid;
(void) snprintf(pidfile, sizeof(pidfile), PIDFILE, PIDDIR);
if ((-1 == (fd = open(pidfile, O_RDWR|O_CREAT, 0644)))
|| (NULL == (fp = fdopen(fd, "r+")))
) {
snprintf(buf, sizeof(buf),
"can't open or create %s: %s",
pidfile, strerror(errno));
warnx(buf);
log_it("CRON", getpid(), "DEATH", buf);
exit(ERROR_EXIT);
}
if (flock(fd, LOCK_EX|LOCK_NB) < OK) {
int save_errno = errno;
fscanf(fp, "%d", &otherpid);
snprintf(buf, sizeof(buf),
"can't lock %s, otherpid may be %d: %s",
pidfile, otherpid, strerror(save_errno));
warnx(buf);
log_it("CRON", getpid(), "DEATH", buf);
exit(ERROR_EXIT);
}
(void) fcntl(fd, F_SETFD, 1);
}
rewind(fp);
fprintf(fp, "%d\n", getpid());
fflush(fp);
(void) ftruncate(fileno(fp), ftell(fp));
/* abandon fd and fp even though the file is open. we need to
* keep it open and locked, but we don't need the handles elsewhere.
*/
}
/* get_char(file) : like getc() but increment LineNumber on newlines
*/
int
get_char(FILE *file)
{
int ch;
ch = getc(file);
if (ch == '\n')
Set_LineNum(LineNumber + 1)
return ch;
}
/* unget_char(ch, file) : like ungetc but do LineNumber processing
*/
void
unget_char(int ch, FILE *file)
{
ungetc(ch, file);
if (ch == '\n')
Set_LineNum(LineNumber - 1)
}
/* get_string(str, max, file, termstr) : like fgets() but
* (1) has terminator string which should include \n
* (2) will always leave room for the null
* (3) uses get_char() so LineNumber will be accurate
* (4) returns EOF or terminating character, whichever
*/
int
get_string(char *string, int size, FILE *file, const char *terms)
{
int ch;
while (EOF != (ch = get_char(file)) && !strchr(terms, ch)) {
if (size > 1) {
*string++ = (char) ch;
size--;
}
}
if (size > 0)
*string = '\0';
return ch;
}
/* skip_comments(file) : read past comment (if any)
*/
void
skip_comments(FILE *file)
{
int ch;
while (EOF != (ch = get_char(file))) {
/* ch is now the first character of a line.
*/
while (ch == ' ' || ch == '\t')
ch = get_char(file);
if (ch == EOF)
break;
/* ch is now the first non-blank character of a line.
*/
if (ch != '\n' && ch != '#')
break;
/* ch must be a newline or comment as first non-blank
* character on a line.
*/
while (ch != '\n' && ch != EOF)
ch = get_char(file);
/* ch is now the newline of a line which we're going to
* ignore.
*/
}
if (ch != EOF)
unget_char(ch, file);
}
/* int in_file(char *string, FILE *file)
* return TRUE if one of the lines in file matches string exactly,
* FALSE otherwise.
*/
static int
in_file(char *string, FILE *file)
{
char line[MAX_TEMPSTR];
rewind(file);
while (fgets(line, MAX_TEMPSTR, file)) {
if (line[0] != '\0')
line[strlen(line)-1] = '\0';
if (0 == strcmp(line, string))
return TRUE;
}
return FALSE;
}
/* int allowed(char *username)
* returns TRUE if (ALLOW_FILE exists and user is listed)
* or (DENY_FILE exists and user is NOT listed)
* or (neither file exists but user=="root" so it's okay)
*/
int
allowed(char *username)
{
static int init = FALSE;
static FILE *allow, *deny;
if (!init) {
init = TRUE;
#if defined(ALLOW_FILE) && defined(DENY_FILE)
allow = fopen(ALLOW_FILE, "r");
deny = fopen(DENY_FILE, "r");
Debug(DMISC, ("allow/deny enabled, %d/%d\n", !!allow, !!deny))
if (allow)
(void)fcntl(fileno(allow), F_SETFD, FD_CLOEXEC);
if (deny)
(void)fcntl(fileno(deny), F_SETFD, FD_CLOEXEC);
#else
allow = NULL;
deny = NULL;
#endif
}
if (allow)
return (in_file(username, allow));
if (deny)
return (!in_file(username, deny));
#if defined(ALLOW_ONLY_ROOT)
return (strcmp(username, ROOT_USER) == 0);
#else
return TRUE;
#endif
}
void
log_it(const char *username, int xpid, const char *event, const char *detail)
{
PID_T pid = xpid;
#if defined(LOG_FILE)
char *msg;
size_t msglen;
TIME_T now = time((TIME_T) 0);
struct tm *t = localtime(&now);
#endif /*LOG_FILE*/
#if defined(SYSLOG)
static int syslog_open = 0;
#endif
#if defined(LOG_FILE)
/* we assume that MAX_TEMPSTR will hold the date, time, &punctuation.
*/
msglen = strlen(username) + strlen(event) + strlen(detail) +
MAX_TEMPSTR;
msg = malloc(msglen);
if (LogFD < OK) {
LogFD = open(LOG_FILE, O_WRONLY|O_APPEND|O_CREAT, 0600);
if (LogFD < OK) {
warn("can't open log file %s", LOG_FILE);
} else {
(void) fcntl(LogFD, F_SETFD, 1);
}
}
/* we have to snprintf() it because fprintf() doesn't always write
* everything out in one chunk and this has to be atomically appended
* to the log file.
*/
snprintf(msg, msglen, "%s (%02d/%02d-%02d:%02d:%02d-%d) %s (%s)\n",
username,
t->tm_mon+1, t->tm_mday, t->tm_hour, t->tm_min, t->tm_sec, pid,
event, detail);
/* we have to run strlen() because sprintf() returns (char*) on old BSD
*/
if (LogFD < OK || write(LogFD, msg, strlen(msg)) < OK) {
if (LogFD >= OK)
warn("can't write to log file");
write(STDERR, msg, strlen(msg));
}
free(msg);
#endif /*LOG_FILE*/
#if defined(SYSLOG)
if (!syslog_open) {
/* we don't use LOG_PID since the pid passed to us by
* our client may not be our own. therefore we want to
* print the pid ourselves.
*/
# ifdef LOG_DAEMON
openlog(getprogname(), LOG_PID, LOG_CRON);
# else
openlog(getprogname(), LOG_PID);
# endif
syslog_open = TRUE; /* assume openlog success */
}
syslog(LOG_INFO, "(%s) %s (%s)\n", username, event, detail);
#endif /*SYSLOG*/
#if DEBUGGING
if (DebugFlags) {
fprintf(stderr, "log_it: (%s %d) %s (%s)\n",
username, pid, event, detail);
}
#endif
}
void
log_close(void) {
if (LogFD != ERR) {
close(LogFD);
LogFD = ERR;
}
}
/* two warnings:
* (1) this routine is fairly slow
* (2) it returns a pointer to static storage
*/
char *
first_word(char *s, /* string we want the first word of */
const char *t /* terminators, implicitly including \0 */)
{
static char retbuf[2][MAX_TEMPSTR + 1]; /* sure wish C had GC */
static int retsel = 0;
char *rb, *rp;
/* select a return buffer */
retsel = 1-retsel;
rb = &retbuf[retsel][0];
rp = rb;
/* skip any leading terminators */
while (*s && (NULL != strchr(t, *s))) {
s++;
}
/* copy until next terminator or full buffer */
while (*s && (NULL == strchr(t, *s)) && (rp < &rb[MAX_TEMPSTR])) {
*rp++ = *s++;
}
/* finish the return-string and return it */
*rp = '\0';
return rb;
}
/* warning:
* heavily ascii-dependent.
*/
static void
mkprint(char *dst, unsigned char *src, int len)
{
while(len > 0 && isblank((unsigned char) *src))
len--, src++;
strvisx(dst, src, len, VIS_TAB|VIS_NL);
}
/* warning:
* returns a pointer to malloc'd storage, you must call free yourself.
*/
char *
mkprints(unsigned char *src, unsigned int len)
{
char *dst = malloc(len*4 + 1);
mkprint(dst, src, len);
return dst;
}
#ifdef MAIL_DATE
/* Sat, 27 Feb 1993 11:44:51 -0800 (CST)
* 1234567890123456789012345678901234567
*/
char *
arpadate(time_t *clock)
{
static char ret[64]; /* zone name might be >3 chars */
time_t t = clock ? *clock : time(NULL);
struct tm *tm = localtime(&t);
int hours = tm->tm_gmtoff / 3600;
int minutes = (tp->tm_gmtoff - (hours * 3600)) / 60;
if (minutes < 0)
minutes = -minutes;
(void)strftime(ret, sizeof(ret), "%a, %e %b %Y %T ????? (%Z)", &tm);
(void)snprintf(strchr(ret, '?'), "% .2d%.2d", hours, minutes);
ret[sizeof(ret) - 1] = '\0';
return ret;
}
#endif /*MAIL_DATE*/
#ifdef HAVE_SAVED_UIDS
static int save_euid;
int swap_uids(void) { save_euid = geteuid(); return seteuid(getuid()); }
#if 0
int swap_uids_back() { return seteuid(save_euid); }
#endif
#else /*HAVE_SAVED_UIDS*/
int swap_uids(void) { return setreuid(geteuid(), getuid()); }
#if 0
int swap_uids_back() { return swap_uids(); }
#endif
#endif /*HAVE_SAVED_UIDS*/