libexec/crond/misc.c

#if !defined(lint) && !defined(LINT)
static char rcsid[] = "$Header: /a/cvs/386BSD/src/libexec/crond/misc.c,v 1.1.1.1 1993/06/12 14:55:03 rgrimes Exp $";
#endif

/* vix 26jan87 [RCS has the rest of the log]
 * vix 15jan87 [added TIOCNOTTY, thanks csg@pyramid]
 * vix 30dec86 [written]
 *
 * PATCHES MAGIC                LEVEL   PATCH THAT GOT US HERE
 * --------------------         -----   ----------------------
 * CURRENT PATCH LEVEL:         1       00131
 * --------------------         -----   ----------------------
 *
 * 06 Apr 93    Adam Glass      Fixes so it compiles quitely
 *
 */

/* Copyright 1988,1990 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, 329 Noe Street, San Francisco, CA, 94114, (415) 864-7013,
 * paul@vixie.sf.ca.us || {hoptoad,pacbell,decwrl,crash}!vixie!paul
 */


#include "cron.h"
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/ioctl.h>
#include <sys/file.h>
#include <errno.h>
#include <string.h>
#if defined(ATT)
# include <fcntl.h>
#endif


void log_it(), be_different(), acquire_daemonlock();


char *
savestr(str)
        char    *str;
{
        extern  char    *malloc(), *strcpy();
        /**/    char    *temp;

        temp = malloc((unsigned) (strlen(str) + 1));
        (void) strcpy(temp, str);
        return temp;
}


int
nocase_strcmp(left, right)
        char    *left;
        char    *right;
{
        while (*left && (MkLower(*left) == MkLower(*right)))
        {
                left++;
                right++;
        }
        return MkLower(*left) - MkLower(*right);
}


int
strcmp_until(left, right, until)
        char    *left;
        char    *right;
        char    until;
{
        register int    diff;

        Debug(DPARS|DEXT, ("strcmp_until(%s,%s,%c) ... ", left, right, until))

        while (*left && *left != until && *left == *right)
        {
                left++;
                right++;
        }

        if (    (*left=='\0' || *left == until)
            &&  (*right=='\0' || *right == until)
           )
                diff = 0;
        else
                diff = *left - *right;

        Debug(DPARS|DEXT, ("%d\n", diff))

        return diff;
}


/* strdtb(s) - delete trailing blanks in string 's' and return new length
 */
int
strdtb(s)
        register char   *s;
{
        register 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 */
}


#if defined(BSD)
void
set_cron_uid()
{
        int     seteuid();

        if (seteuid(ROOT_UID) < OK)
        {
                perror("seteuid");
                exit(ERROR_EXIT);
        }
}
#endif

#if defined(ATT)
void
set_cron_uid()
{
        int     setuid();

        if (setuid(ROOT_UID) < OK)
        {
                perror("setuid");
                exit(ERROR_EXIT);
        }
}
#endif

void
set_cron_cwd()
{
        extern int      errno;
        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);
        }
}


#if defined(BSD)
void
be_different()
{
        /* release the control terminal:
         *  get new pgrp (name after our PID)
         *  do an IOCTL to void tty association
         */

        auto int        fd;

        (void) setpgrp(0, getpid());

        if ((fd = open("/dev/tty", 2)) >= 0)
        {
                (void) ioctl(fd, TIOCNOTTY, (char*)0);
                (void) close(fd);
        }
}
#endif /*BSD*/

#if defined(ATT)
void
be_different()
{
        /* not being a system V wiz, I don't know if this is what you have
         * to do to release your control terminal.  what I want to accomplish
         * is to keep this process from getting any signals from the tty.
         *
         * some system V person should let me know if this works... (vixie)
         */
        int     setpgrp(), close(), open();

        (void) setpgrp();

        (void) close(STDIN);    (void) open("/dev/null", 0);
        (void) close(STDOUT);   (void) open("/dev/null", 1);
        (void) close(STDERR);   (void) open("/dev/null", 2);
}
#endif /*ATT*/


/* acquire_daemonlock() - write our PID into /etc/crond.pid, unless
 *      another daemon is already running, which we detect here.
 */
void
acquire_daemonlock()
{
        int     fd = open(PIDFILE, O_RDWR|O_CREAT, 0644);
        FILE    *fp = fdopen(fd, "r+");
        int     pid = getpid(), otherpid;
        char    buf[MAX_TEMPSTR];

        if (fd < 0 || fp == NULL) {
                sprintf(buf, "can't open or create %s, errno %d", PIDFILE, errno);
                log_it("CROND", pid, "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, errno %d",
                        PIDFILE, otherpid, save_errno);
                log_it("CROND", pid, "DEATH", buf);
                exit(ERROR_EXIT);
        }

        rewind(fp);
        fprintf(fp, "%d\n", pid);
        fflush(fp);
        ftruncate(fd, 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;
        char    *index();

        while (EOF != (ch = get_char(file)) && !index(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.
                 */
        }
        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.
 */
int
in_file(string, file)
        char *string;
        FILE *file;
{
        char line[MAX_TEMPSTR];

        /* let's be persnickety today.
         */
        if (!file) {
                if (!string)
                        string = "0x0";
                fprintf(stderr,
                        "in_file(\"%s\", 0x%x): called with NULL file--botch",
                        string, file);
                exit(ERROR_EXIT);
        }

        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
}


#if defined(LOG_FILE) || defined(SYSLOG)
void
log_it(username, pid, event, detail)
        char    *username;
        int     pid;
        char    *event;
        char    *detail;
{
#if defined(LOG_FILE)
        extern struct tm        *localtime();
        extern long             time();
        extern char             *malloc();
        auto char               *msg;
        auto long               now = time((long *) 0);
        register struct tm      *t = localtime(&now);
        static int              log_fd = -1;
#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 (log_fd < OK) {
                log_fd = open(LOG_FILE, O_WRONLY|O_APPEND|O_CREAT, 0600);
                if (log_fd < OK) {
                        fprintf(stderr, "%s: can't open log file\n", ProgramName);
                        perror(LOG_FILE);
                }
        }

        /* 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 BSD
         */
        if (log_fd < OK || write(log_fd, msg, strlen(msg)) < OK) {
                fprintf(stderr, "%s: can't write to log file\n", ProgramName);
                if (log_fd >= OK)
                        perror(LOG_FILE);
                write(STDERR, msg, strlen(msg));
        }

        /* I suppose we could use alloca()...
         */
        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_CRON
                openlog(ProgramName, 0, LOG_CRON);
# else
# ifdef LOG_DAEMON
                openlog(ProgramName, 0, LOG_DAEMON);
# else
                openlog(ProgramName, 0);
# endif /*LOG_DAEMON*/
# endif /*LOG_CRON*/
                syslog_open = TRUE;             /* assume openlog success */
        }

        syslog(LOG_INFO, "(%s %d) %s (%s)\n",
                username, pid, event, detail);

#endif /*SYSLOG*/

        if (DebugFlags) {
                fprintf(stderr, "log_it: (%s %d) %s (%s)",
                        username, pid, event, detail);
        }
}
#endif /*LOG_FILE || SYSLOG */


/* two warnings:
 *      (1) this routine is fairly slow
 *      (2) it returns a pointer to static storage
 */
char *
first_word(s, t)
        local char *s;  /* string we want the first word of */
        local char *t;  /* terminators, implicitly including \0 */
{
        static char retbuf[2][MAX_TEMPSTR + 1]; /* sure wish I had GC */
        static int retsel = 0;
        local char *rb, *rp;
        extern char *index();

        /* select a return buffer */
        retsel = 1-retsel;
        rb = &retbuf[retsel][0];
        rp = rb;

        /* skip any leading terminators */
        while (*s && (NULL != index(t, *s))) {s++;}

        /* copy until next terminator or full buffer */
        while (*s && (NULL == index(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 = NULL;
}


/* 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;
{
        extern char *malloc();
        register char *dst = malloc(len*4 + 1);

        mkprint(dst, src, len);

        return dst;
}