Added mroute map-mbone and mrinfo to a CLEANFILE target. Otherwise

[unix-history] / usr.sbin / cron / misc.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
* From Id: misc.c,v 2.9 1994/01/15 20:43:43 vixie Exp
*/

#if !defined(lint) && !defined(LINT)
static char rcsid[] = "$Header: $";
#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*/