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/* $NetBSD: misc.c,v 1.5 2017/08/17 08:53:00 christos 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: misc.c,v 1.16 2004/01/23 18:56:43 vixie Exp";
#else
__RCSID("$NetBSD: misc.c,v 1.5 2017/08/17 08:53:00 christos Exp $");
#endif
#endif
/* vix 26jan87 [RCS has the rest of the log]
* vix 30dec86 [written]
*/
#include "cron.h"
#include <limits.h>
#include <vis.h>
#if defined(SYSLOG) && defined(LOG_FILE)
# undef LOG_FILE
#endif
#if defined(LOG_DAEMON) && !defined(LOG_CRON)
# define LOG_CRON LOG_DAEMON
#endif
#ifndef FACILITY
#define FACILITY LOG_CRON
#endif
static int LogFD = ERR;
#if defined(SYSLOG)
static int syslog_open = FALSE;
#endif
static void mkprint(char *, char *, size_t);
/*
* glue_strings is the overflow-safe equivalent of
* sprintf(buffer, "%s%c%s", a, separator, b);
*
* returns 1 on success, 0 on failure. 'buffer' MUST NOT be used if
* glue_strings fails.
*/
int
glue_strings(char *buffer, size_t buffer_size, const char *a, const char *b,
char separator)
{
char *buf;
char *buf_end;
if (buffer_size == 0)
return (0);
buf_end = buffer + buffer_size;
buf = buffer;
for ( /* nothing */; buf < buf_end && *a != '\0'; buf++, a++ )
*buf = *a;
if (buf == buf_end)
return (0);
if (separator != '/' || buf == buffer || buf[-1] != '/')
*buf++ = separator;
if (buf == buf_end)
return (0);
for ( /* nothing */; buf < buf_end && *b != '\0'; buf++, b++ )
*buf = *b;
if (buf == buf_end)
return (0);
*buf = '\0';
return (1);
}
int
strcmp_until(const char *left, const char *right, char until) {
while (*left && *left != until && *left == *right) {
left++;
right++;
}
if ((*left=='\0' || *left == until) &&
(*right=='\0' || *right == until)) {
return (0);
}
return (*left - *right);
}
#ifdef notdef
/* 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 (int)(x - s);
}
#endif
int
set_debug_flags(const 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 */
const 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 != NULL && strcmp_until(*test, pc, ',');
test++, mask <<= 1)
continue;
if (!*test) {
warnx("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;
(void)fprintf(stderr, "debug flags enabled:");
for (flag = 0; DebugFlagNames[flag]; flag++)
if (DebugFlags & (1 << flag))
(void)fprintf(stderr, " %s", DebugFlagNames[flag]);
(void)fprintf(stderr, "\n");
}
return (TRUE);
#endif /* DEBUGGING */
}
void
set_cron_uid(void) {
#if defined(BSD) || defined(POSIX)
if (seteuid(ROOT_UID) < OK) {
err(ERROR_EXIT, "cannot seteuid");
}
#else
if (setuid(ROOT_UID) < OK) {
err(ERROR_EXIT, "cannot setuid");
}
#endif
}
void
set_cron_cwd(void) {
struct stat sb;
struct group *grp = NULL;
#ifdef CRON_GROUP
grp = getgrnam(CRON_GROUP);
#endif
/* first check for CRONDIR ("/var/cron" or some such)
*/
#ifdef ENABLE_FIX_DIRECTORIES
if (stat(CRONDIR, &sb) < OK && errno == ENOENT) {
warn("Cannot stat `%s'", CRONDIR);
if (OK == mkdir(CRONDIR, 0710)) {
(void)fprintf(stderr, "%s: created\n", CRONDIR);
if (stat(CRONDIR, &sb) == -1)
err(ERROR_EXIT, "cannot stat `%s'", CRONDIR);
} else {
err(ERROR_EXIT, "cannot create `%s'", CRONDIR);
}
}
if (!S_ISDIR(sb.st_mode)) {
errx(ERROR_EXIT, "`%s' is not a directory, bailing out.",
CRONDIR);
}
#endif /* ENABLE_FIX_DIRECTORIES */
if (chdir(CRONDIR) < OK) {
err(ERROR_EXIT, "cannot chdir `%s', bailing out.\n", CRONDIR);
}
/* CRONDIR okay (now==CWD), now look at SPOOL_DIR ("tabs" or some such)
*/
#ifdef ENABLE_FIX_DIRECTORIES
if (stat(SPOOL_DIR, &sb) < OK && errno == ENOENT) {
warn("cannot stat `%s'", SPOOL_DIR);
if (OK == mkdir(SPOOL_DIR, 0700)) {
(void)fprintf(stderr, "%s: created\n", SPOOL_DIR);
if (stat(SPOOL_DIR, &sb) == -1)
err(ERROR_EXIT, "cannot stat `%s'", CRONDIR);
} else {
err(ERROR_EXIT, "cannot create `%s'", SPOOL_DIR);
}
}
#else
if (stat(SPOOL_DIR, &sb)) {
err(ERROR_EXIT, "cannot stat `%s'", SPOOL_DIR);
}
#endif /* ENABLE_FIX_DIRECTORIES */
if (!S_ISDIR(sb.st_mode)) {
errx(ERROR_EXIT, "`%s' is not a directory, bailing out.",
SPOOL_DIR);
}
if (grp != NULL) {
if (sb.st_gid != grp->gr_gid) {
#ifdef ENABLE_FIX_DIRECTORIES
errx(ERROR_EXIT, "Bad group %d != %d for `%s'",
(int)sb.st_gid, (int)grp->gr_gid, SPOOL_DIR);
#else
if (chown(SPOOL_DIR, (uid_t)-1, grp->gr_gid) == -1)
err(ERROR_EXIT, "cannot chown `%s'", SPOOL_DIR);
#endif
}
if (sb.st_mode != 01730)
#ifdef ENABLE_FIX_DIRECTORIES
errx(ERROR_EXIT, "Bad mode %#o != %#o for `%s'",
(int)sb.st_mode, 01730, SPOOL_DIR);
#else
if (chmod(SPOOL_DIR, 01730) == -1)
err(ERROR_EXIT, "cannot chmod `%s'", SPOOL_DIR);
#endif
}
}
/* 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 _PATH_CRON_PID after the fork.
*/
void
acquire_daemonlock(int closeflag) {
static int fd = -1;
char buf[3*MAX_FNAME];
const char *pidfile;
char *ep;
long otherpid;
ssize_t num;
if (closeflag) {
/* close stashed fd for child so we don't leak it. */
if (fd != -1) {
(void)close(fd);
fd = -1;
}
return;
}
if (fd == -1) {
pidfile = _PATH_CRON_PID;
/* Initial mode is 0600 to prevent flock() race/DoS. */
if ((fd = open(pidfile, O_RDWR|O_CREAT, 0600)) == -1) {
log_itx("CRON", getpid(), "DEATH",
"can't open or create %s: %s",
pidfile, strerror(errno));
exit(ERROR_EXIT);
}
/* fd must be > STDERR since we dup fd 0-2 to /dev/null */
if (fd <= STDERR) {
if (dup2(fd, STDERR + 1) < 0) {
log_itx("CRON", getpid(), "DEATH",
"can't dup pid fd: %s", strerror(errno));
exit(ERROR_EXIT);
}
close(fd);
fd = STDERR + 1;
}
if (flock(fd, LOCK_EX|LOCK_NB) < OK) {
int save_errno = errno;
memset(buf, 0, sizeof(buf));
if ((num = read(fd, buf, sizeof(buf) - 1)) > 0 &&
(otherpid = strtol(buf, &ep, 10)) > 0 &&
ep != buf && *ep == '\n' && otherpid != LONG_MAX) {
log_itx("CRON", getpid(), "DEATH",
"can't lock %s, otherpid may be %ld: %s",
pidfile, otherpid, strerror(save_errno));
} else {
log_itx("CRON", getpid(), "DEATH",
"can't lock %s, otherpid unknown: %s",
pidfile, strerror(save_errno));
}
exit(ERROR_EXIT);
}
(void) fchmod(fd, 0644);
(void) fcntl(fd, F_SETFD, 1);
}
(void)snprintf(buf, sizeof(buf), "%ld\n", (long)getpid());
(void) lseek(fd, (off_t)0, SEEK_SET);
num = write(fd, buf, strlen(buf));
(void) ftruncate(fd, num);
/* abandon fd 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) {
(void)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);
}
void
log_itx(const char *username, PID_T xpid, const char *event, const char *fmt,
...)
{
char *detail;
va_list ap;
va_start(ap, fmt);
if (vasprintf(&detail, fmt, ap) == -1) {
va_end(ap);
return;
}
log_it(username, xpid, event, detail);
free(detail);
}
void
log_it(const char *username, PID_T xpid, const char *event, const char *detail) {
#if defined(LOG_FILE) || DEBUGGING
PID_T pid = xpid;
#endif
#if defined(LOG_FILE)
char *msg;
int msglen;
TIME_T now = time((TIME_T) 0);
struct tm *t = localtime(&now);
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, FD_CLOEXEC);
}
}
/* 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.
*/
msglen = asprintf(&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);
if (msglen == -1)
return;
if (LogFD < OK || write(LogFD, msg, (size_t)msglen) < OK) {
warn("can't write to log file");
write(STDERR, msg, (size_t)msglen);
}
free(msg);
#endif /*LOG_FILE*/
#if defined(SYSLOG)
if (!syslog_open) {
# ifdef LOG_DAEMON
openlog(getprogname(), LOG_PID, FACILITY);
# else
openlog(getprogname(), LOG_PID);
# endif
syslog_open = TRUE; /* assume openlog success */
}
syslog(LOG_INFO, "(%s) %s (%s)", username, event, detail);
#endif /*SYSLOG*/
#if DEBUGGING
if (DebugFlags) {
(void)fprintf(stderr, "log_it: (%s %ld) %s (%s)\n",
username, (long)pid, event, detail);
}
#endif
}
void
log_close(void) {
if (LogFD != ERR) {
(void)close(LogFD);
LogFD = ERR;
}
#if defined(SYSLOG)
closelog();
syslog_open = FALSE;
#endif /*SYSLOG*/
}
/* warning:
* heavily ascii-dependent.
*/
static void
mkprint(char *dst, char *src, size_t len)
{
while(len > 0 && isblank((unsigned char) *src))
len--, src++;
(void)strvisx(dst, src, len, VIS_TAB|VIS_NL);
}
/* warning:
* returns a pointer to malloc'd storage, you must call free yourself.
*/
char *
mkprints(char *src, size_t len)
{
char *dst = malloc(len*4 + 1);
if (dst)
mkprint(dst, src, len);
return (dst);
}
#ifdef MAIL_DATE
/* Sat, 27 Feb 1993 11:44:51 -0800 (CST)
* 1234567890123456789012345678901234567
*/
char *
arpadate(time_t *clock)
{
time_t t = clock ? *clock : time((TIME_T) 0);
struct tm tm = *localtime(&t);
long gmtoff = get_gmtoff(&t, &tm);
int hours = gmtoff / SECONDS_PER_HOUR;
int minutes = (gmtoff - (hours * SECONDS_PER_HOUR)) / SECONDS_PER_MINUTE;
static char ret[64]; /* zone name might be >3 chars */
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*/
size_t
strlens(const char *last, ...) {
va_list ap;
size_t ret = 0;
const char *str;
va_start(ap, last);
for (str = last; str != NULL; str = va_arg(ap, const char *))
ret += strlen(str);
va_end(ap);
return (ret);
}
/* Return the offset from GMT in seconds (algorithm taken from sendmail).
*
* warning:
* clobbers the static storage space used by localtime() and gmtime().
* If the local pointer is non-NULL it *must* point to a local copy.
*/
#ifndef HAVE_TM_GMTOFF
long get_gmtoff(time_t *clock, struct tm *local)
{
struct tm gmt;
long offset;
gmt = *gmtime(clock);
if (local == NULL)
local = localtime(clock);
offset = (local->tm_sec - gmt.tm_sec) +
((local->tm_min - gmt.tm_min) * 60) +
((local->tm_hour - gmt.tm_hour) * 3600);
/* Timezone may cause year rollover to happen on a different day. */
if (local->tm_year < gmt.tm_year)
offset -= 24 * 3600;
else if (local->tm_year > gmt.tm_year)
offset -= 24 * 3600;
else if (local->tm_yday < gmt.tm_yday)
offset -= 24 * 3600;
else if (local->tm_yday > gmt.tm_yday)
offset += 24 * 3600;
return (offset);
}
#endif /* HAVE_TM_GMTOFF */
|