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freebsd/usr.sbin/cron/lib/misc.c
Jordan K. Hubbard 84f33dea62 Paul Vixie's cron, version 3.0. Munged into bmake format. If this goes
well, expect our two seperate directories for cron and crontab to go away
shortly.
Submitted by:	jkh
1994-08-27 13:43:04 +00:00

665 lines
13 KiB
C

/* 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
*/
#if !defined(lint) && !defined(LINT)
static char rcsid[] = "$Id: misc.c,v 2.9 1994/01/15 20:43:43 vixie Exp $";
#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 <errno.h>
#include <string.h>
#include <fcntl.h>
#if defined(SYSLOG)
# include <syslog.h>
#endif
#if defined(LOG_DAEMON) && !defined(LOG_CRON)
#define LOG_CRON LOG_DAEMON
#endif
static int LogFD = ERR;
int
strcmp_until(left, right, until)
char *left;
char *right;
int until;
{
register 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(s)
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(*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(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) {
char **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()
{
#if defined(BSD) || defined(POSIX)
if (seteuid(ROOT_UID) < OK) {
perror("seteuid");
exit(ERROR_EXIT);
}
#else
if (setuid(ROOT_UID) < OK) {
perror("setuid");
exit(ERROR_EXIT);
}
#endif
}
void
set_cron_cwd()
{
struct stat sb;
/* first check for CRONDIR ("/var/cron" or some such)
*/
if (stat(CRONDIR, &sb) < OK && errno == ENOENT) {
perror(CRONDIR);
if (OK == mkdir(CRONDIR, 0700)) {
fprintf(stderr, "%s: created\n", CRONDIR);
stat(CRONDIR, &sb);
} else {
fprintf(stderr, "%s: ", CRONDIR);
perror("mkdir");
exit(ERROR_EXIT);
}
}
if (!(sb.st_mode & S_IFDIR)) {
fprintf(stderr, "'%s' is not a directory, bailing out.\n",
CRONDIR);
exit(ERROR_EXIT);
}
if (chdir(CRONDIR) < OK) {
fprintf(stderr, "cannot chdir(%s), bailing out.\n", CRONDIR);
perror(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) {
perror(SPOOL_DIR);
if (OK == mkdir(SPOOL_DIR, 0700)) {
fprintf(stderr, "%s: created\n", SPOOL_DIR);
stat(SPOOL_DIR, &sb);
} else {
fprintf(stderr, "%s: ", SPOOL_DIR);
perror("mkdir");
exit(ERROR_EXIT);
}
}
if (!(sb.st_mode & S_IFDIR)) {
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(closeflag)
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) sprintf(pidfile, PIDFILE, PIDDIR);
if ((-1 == (fd = open(pidfile, O_RDWR|O_CREAT, 0644)))
|| (NULL == (fp = fdopen(fd, "r+")))
) {
sprintf(buf, "can't open or create %s: %s",
pidfile, strerror(errno));
fprintf(stderr, "%s: %s\n", ProgramName, 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);
sprintf(buf, "can't lock %s, otherpid may be %d: %s",
pidfile, otherpid, strerror(save_errno));
fprintf(stderr, "%s: %s\n", ProgramName, 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 *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(ch, file)
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(string, size, file, terms)
char *string;
int size;
FILE *file;
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 *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(string, 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(username)
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))
#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(username, xpid, event, detail)
char *username;
int xpid;
char *event;
char *detail;
{
PID_T pid = xpid;
#if defined(LOG_FILE)
char *msg;
TIME_T now = time((TIME_T) 0);
register 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.
*/
msg = malloc(strlen(username)
+ strlen(event)
+ strlen(detail)
+ MAX_TEMPSTR);
if (LogFD < OK) {
LogFD = open(LOG_FILE, O_WRONLY|O_APPEND|O_CREAT, 0600);
if (LogFD < OK) {
fprintf(stderr, "%s: can't open log file\n",
ProgramName);
perror(LOG_FILE);
} else {
(void) fcntl(LogFD, F_SETFD, 1);
}
}
/* we have to sprintf() it because fprintf() doesn't always write
* everything out in one chunk and this has to be atomically appended
* to the log file.
*/
sprintf(msg, "%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)
perror(LOG_FILE);
fprintf(stderr, "%s: can't write to log file\n", ProgramName);
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(ProgramName, LOG_PID, LOG_CRON);
# else
openlog(ProgramName, 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() {
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(s, t)
register char *s; /* string we want the first word of */
register char *t; /* terminators, implicitly including \0 */
{
static char retbuf[2][MAX_TEMPSTR + 1]; /* sure wish C had GC */
static int retsel = 0;
register 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.
*/
void
mkprint(dst, src, len)
register char *dst;
register unsigned char *src;
register int len;
{
while (len-- > 0)
{
register unsigned char ch = *src++;
if (ch < ' ') { /* control character */
*dst++ = '^';
*dst++ = ch + '@';
} else if (ch < 0177) { /* printable */
*dst++ = ch;
} else if (ch == 0177) { /* delete/rubout */
*dst++ = '^';
*dst++ = '?';
} else { /* parity character */
sprintf(dst, "\\%03o", ch);
dst += 4;
}
}
*dst = '\0';
}
/* warning:
* returns a pointer to malloc'd storage, you must call free yourself.
*/
char *
mkprints(src, len)
register unsigned char *src;
register unsigned int len;
{
register char *dst = malloc(len*4 + 1);
mkprint(dst, src, len);
return dst;
}
#ifdef MAIL_DATE
/* Sat, 27 Feb 93 11:44:51 CST
* 123456789012345678901234567
*/
char *
arpadate(clock)
time_t *clock;
{
time_t t = clock ?*clock :time(0L);
struct tm *tm = localtime(&t);
static char ret[30]; /* zone name might be >3 chars */
(void) sprintf(ret, "%s, %2d %s %2d %02d:%02d:%02d %s",
DowNames[tm->tm_wday],
tm->tm_mday,
MonthNames[tm->tm_mon],
tm->tm_year,
tm->tm_hour,
tm->tm_min,
tm->tm_sec,
TZONE(*tm));
return ret;
}
#endif /*MAIL_DATE*/
#ifdef HAVE_SAVED_SUIDS
static int save_euid;
int swap_uids() { save_euid = geteuid(); return seteuid(getuid()); }
int swap_uids_back() { return seteuid(save_euid); }
#else /*HAVE_SAVED_UIDS*/
int swap_uids() { return setreuid(geteuid(), getuid()); }
int swap_uids_back() { return swap_uids(); }
#endif /*HAVE_SAVED_UIDS*/