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cronie/src/entry.c

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/*
* 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.
*/
/* vix 26jan87 [RCS'd; rest of log is in RCS file]
* vix 01jan87 [added line-level error recovery]
* vix 31dec86 [added /step to the from-to range, per bob@acornrc]
* vix 30dec86 [written]
*/
#include "config.h"
#include <ctype.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#include <errno.h>
#include "bitstring.h"
#include "funcs.h"
#include "globals.h"
#include "macros.h"
#include "pathnames.h"
typedef enum ecode {
e_none, e_minute, e_hour, e_dom, e_month, e_dow,
e_cmd, e_timespec, e_username, e_option, e_memory
} ecode_e;
static const char *ecodes[] = {
"no error",
"bad minute",
"bad hour",
"bad day-of-month",
"bad month",
"bad day-of-week",
"bad command",
"bad time specifier",
"bad username",
"bad option",
"out of memory"
};
static int get_list(bitstr_t *, int, int, const char *[], int, FILE *),
get_range(bitstr_t *, int, int, const char *[], int, FILE *),
get_number(int *, int, const char *[], int, FILE *, const char *),
set_element(bitstr_t *, int, int, int);
void free_entry(entry * e) {
free(e->cmd);
free(e->pwd);
env_free(e->envp);
free(e);
}
/* return NULL if eof or syntax error occurs;
* otherwise return a pointer to a new entry.
*/
entry *load_entry(FILE * file, void (*error_func) (), struct passwd *pw,
char **envp) {
/* this function reads one crontab entry -- the next -- from a file.
* it skips any leading blank lines, ignores comments, and returns
* NULL if for any reason the entry can't be read and parsed.
*
* the entry is also parsed here.
*
* syntax:
* user crontab:
* minutes hours doms months dows cmd\n
* system crontab (/etc/crontab):
* minutes hours doms months dows USERNAME cmd\n
*/
ecode_e ecode = e_none;
entry *e = NULL;
int ch;
char cmd[MAX_COMMAND];
char envstr[MAX_ENVSTR];
char **tenvp;
char *p;
struct passwd temppw;
int i;
Debug(DPARS, ("load_entry()...about to eat comments\n"));
ch = get_char(file);
if (ch == EOF)
return (NULL);
/* ch is now the first useful character of a useful line.
* it may be an @special or it may be the first character
* of a list of minutes.
*/
e = (entry *) calloc(sizeof (entry), sizeof (char));
if (e == NULL) {
ecode = e_memory;
goto eof;
}
/* check for '-' as a first character, this option will disable
* writing a syslog message about command getting executed
*/
if (ch == '-') {
/* if we are editing system crontab or user uid is 0 (root)
* we are allowed to disable logging
*/
if (pw == NULL || pw->pw_uid == 0)
e->flags |= DONT_LOG;
else {
log_it("CRON", getpid(), "ERROR", "Only privileged user can disable logging", 0);
ecode = e_option;
goto eof;
}
ch = get_char(file);
if (ch == EOF) {
free(e);
return NULL;
}
}
if (ch == '@') {
/* all of these should be flagged and load-limited; i.e.,
* instead of @hourly meaning "0 * * * *" it should mean
* "close to the front of every hour but not 'til the
* system load is low". Problems are: how do you know
* what "low" means? (save me from /etc/cron.conf!) and:
* how to guarantee low variance (how low is low?), which
* means how to we run roughly every hour -- seems like
* we need to keep a history or let the first hour set
* the schedule, which means we aren't load-limited
* anymore. too much for my overloaded brain. (vix, jan90)
* HINT
*/
ch = get_string(cmd, MAX_COMMAND, file, " \t\n");
if (!strcmp("reboot", cmd)) {
e->flags |= WHEN_REBOOT;
}
else if (!strcmp("yearly", cmd) || !strcmp("annually", cmd)) {
bit_set(e->minute, 0);
bit_set(e->hour, 0);
bit_set(e->dom, 0);
bit_set(e->month, 0);
bit_nset(e->dow, 0, LAST_DOW - FIRST_DOW);
e->flags |= DOW_STAR;
}
else if (!strcmp("monthly", cmd)) {
bit_set(e->minute, 0);
bit_set(e->hour, 0);
bit_set(e->dom, 0);
bit_nset(e->month, 0, LAST_MONTH - FIRST_MONTH);
bit_nset(e->dow, 0, LAST_DOW - FIRST_DOW);
e->flags |= DOW_STAR;
}
else if (!strcmp("weekly", cmd)) {
bit_set(e->minute, 0);
bit_set(e->hour, 0);
bit_nset(e->dom, 0, LAST_DOM - FIRST_DOM);
bit_nset(e->month, 0, LAST_MONTH - FIRST_MONTH);
bit_set(e->dow, 0);
e->flags |= DOW_STAR;
}
else if (!strcmp("daily", cmd) || !strcmp("midnight", cmd)) {
bit_set(e->minute, 0);
bit_set(e->hour, 0);
bit_nset(e->dom, 0, LAST_DOM - FIRST_DOM);
bit_nset(e->month, 0, LAST_MONTH - FIRST_MONTH);
bit_nset(e->dow, 0, LAST_DOW - FIRST_DOW);
}
else if (!strcmp("hourly", cmd)) {
bit_set(e->minute, 0);
bit_nset(e->hour, 0, LAST_HOUR - FIRST_HOUR);
bit_nset(e->dom, 0, LAST_DOM - FIRST_DOM);
bit_nset(e->month, 0, LAST_MONTH - FIRST_MONTH);
bit_nset(e->dow, 0, LAST_DOW - FIRST_DOW);
e->flags |= HR_STAR;
}
else {
ecode = e_timespec;
goto eof;
}
/* Advance past whitespace between shortcut and
* username/command.
*/
Skip_Blanks(ch, file);
if (ch == EOF || ch == '\n') {
ecode = e_cmd;
goto eof;
}
}
else {
Debug(DPARS, ("load_entry()...about to parse numerics\n"));
if (ch == '*')
e->flags |= MIN_STAR;
ch = get_list(e->minute, FIRST_MINUTE, LAST_MINUTE, PPC_NULL, ch, file);
if (ch == EOF) {
ecode = e_minute;
goto eof;
}
/* hours
*/
if (ch == '*')
e->flags |= HR_STAR;
ch = get_list(e->hour, FIRST_HOUR, LAST_HOUR, PPC_NULL, ch, file);
if (ch == EOF) {
ecode = e_hour;
goto eof;
}
/* DOM (days of month)
*/
if (ch == '*')
e->flags |= DOM_STAR;
ch = get_list(e->dom, FIRST_DOM, LAST_DOM, PPC_NULL, ch, file);
if (ch == EOF) {
ecode = e_dom;
goto eof;
}
/* month
*/
ch = get_list(e->month, FIRST_MONTH, LAST_MONTH, MonthNames, ch, file);
if (ch == EOF) {
ecode = e_month;
goto eof;
}
/* DOW (days of week)
*/
if (ch == '*')
e->flags |= DOW_STAR;
ch = get_list(e->dow, FIRST_DOW, LAST_DOW, DowNames, ch, file);
if (ch == EOF) {
ecode = e_dow;
goto eof;
}
}
/* make sundays equivalent */
if (bit_test(e->dow, 0) || bit_test(e->dow, 7)) {
bit_set(e->dow, 0);
bit_set(e->dow, 7);
}
/* check for permature EOL and catch a common typo */
if (ch == '\n' || ch == '*') {
ecode = e_cmd;
goto eof;
}
/* ch is the first character of a command, or a username */
unget_char(ch, file);
if (!pw) {
char *username = cmd; /* temp buffer */
Debug(DPARS, ("load_entry()...about to parse username\n"));
ch = get_string(username, MAX_COMMAND, file, " \t\n");
Debug(DPARS, ("load_entry()...got %s\n", username));
if (ch == EOF || ch == '\n' || ch == '*') {
ecode = e_cmd;
goto eof;
}
pw = getpwnam(username);
if (pw == NULL) {
Debug(DPARS, ("load_entry()...unknown user entry\n"));
memset(&temppw, 0, sizeof (temppw));
temppw.pw_name = username;
temppw.pw_passwd = "";
pw = &temppw;
} else {
Debug(DPARS, ("load_entry()...uid %ld, gid %ld\n",
(long) pw->pw_uid, (long) pw->pw_gid));
}
}
if ((e->pwd = pw_dup(pw)) == NULL) {
ecode = e_memory;
goto eof;
}
memset(e->pwd->pw_passwd, 0, strlen(e->pwd->pw_passwd));
p = env_get("RANDOM_DELAY", envp);
if (p) {
char *endptr;
long val;
errno = 0; /* To distinguish success/failure after call */
val = strtol(p, &endptr, 10);
if (errno != 0 || val < 0 || val > 24*60) {
log_it("CRON", getpid(), "ERROR", "bad value of RANDOM_DELAY", 0);
} else {
e->delay = (int)((double)val * RandomScale);
}
}
/* copy and fix up environment. some variables are just defaults and
* others are overrides.
*/
if ((e->envp = env_copy(envp)) == NULL) {
ecode = e_memory;
goto eof;
}
if (!env_get("SHELL", e->envp)) {
if (glue_strings(envstr, sizeof envstr, "SHELL", _PATH_BSHELL, '=')) {
if ((tenvp = env_set(e->envp, envstr)) == NULL) {
ecode = e_memory;
goto eof;
}
e->envp = tenvp;
}
else
log_it("CRON", getpid(), "ERROR", "can't set SHELL", 0);
}
if ((tenvp = env_update_home(e->envp, pw->pw_dir)) == NULL) {
ecode = e_memory;
goto eof;
}
e->envp = tenvp;
#ifndef LOGIN_CAP
/* If login.conf is in used we will get the default PATH later. */
if (!env_get("PATH", e->envp)) {
char *defpath;
if (ChangePath)
defpath = _PATH_DEFPATH;
else {
defpath = getenv("PATH");
if (defpath == NULL)
defpath = _PATH_DEFPATH;
}
if (glue_strings(envstr, sizeof envstr, "PATH", defpath, '=')) {
if ((tenvp = env_set(e->envp, envstr)) == NULL) {
ecode = e_memory;
goto eof;
}
e->envp = tenvp;
}
else
log_it("CRON", getpid(), "ERROR", "can't set PATH", 0);
}
#endif /* LOGIN_CAP */
if (glue_strings(envstr, sizeof envstr, "LOGNAME", pw->pw_name, '=')) {
if ((tenvp = env_set(e->envp, envstr)) == NULL) {
ecode = e_memory;
goto eof;
}
e->envp = tenvp;
}
else
log_it("CRON", getpid(), "ERROR", "can't set LOGNAME", 0);
#if defined(BSD) || defined(__linux)
if (glue_strings(envstr, sizeof envstr, "USER", pw->pw_name, '=')) {
if ((tenvp = env_set(e->envp, envstr)) == NULL) {
ecode = e_memory;
goto eof;
}
e->envp = tenvp;
}
else
log_it("CRON", getpid(), "ERROR", "can't set USER", 0);
#endif
Debug(DPARS, ("load_entry()...about to parse command\n"));
/* Everything up to the next \n or EOF is part of the command...
* too bad we don't know in advance how long it will be, since we
* need to malloc a string for it... so, we limit it to MAX_COMMAND.
*/
ch = get_string(cmd, MAX_COMMAND, file, "\n");
/* a file without a \n before the EOF is rude, so we'll complain...
*/
if (ch == EOF) {
ecode = e_cmd;
goto eof;
}
/* got the command in the 'cmd' string; save it in *e.
*/
if ((e->cmd = strdup(cmd)) == NULL) {
ecode = e_memory;
goto eof;
}
Debug(DPARS, ("load_entry()...returning successfully\n"));
/* success, fini, return pointer to the entry we just created...
*/
return (e);
eof:
if (e) {
if (e->envp)
env_free(e->envp);
free(e->pwd);
free(e->cmd);
free(e);
}
for (i = 0; i < MAX_COMMAND && ch != '\n' && !feof(file); i++)
ch = get_char(file);
if (ecode != e_none && error_func)
(*error_func) (ecodes[(int) ecode]);
return (NULL);
}
static int
get_list(bitstr_t * bits, int low, int high, const char *names[],
int ch, FILE * file) {
int done;
/* we know that we point to a non-blank character here;
* must do a Skip_Blanks before we exit, so that the
* next call (or the code that picks up the cmd) can
* assume the same thing.
*/
Debug(DPARS | DEXT, ("get_list()...entered\n"));
/* list = range {"," range}
*/
/* clear the bit string, since the default is 'off'.
*/
bit_nclear(bits, 0, (high - low));
/* process all ranges
*/
done = FALSE;
while (!done) {
if (EOF == (ch = get_range(bits, low, high, names, ch, file)))
return (EOF);
if (ch == ',')
ch = get_char(file);
else
done = TRUE;
}
/* exiting. skip to some blanks, then skip over the blanks.
*/
Skip_Nonblanks(ch, file)
Skip_Blanks(ch, file)
Debug(DPARS | DEXT, ("get_list()...exiting w/ %02x\n", ch));
return (ch);
}
static int
get_range(bitstr_t * bits, int low, int high, const char *names[],
int ch, FILE * file) {
/* range = number | number "-" number [ "/" number ]
*/
int i, num1, num2, num3;
Debug(DPARS | DEXT, ("get_range()...entering, exit won't show\n"));
if (ch == '*') {
/* '*' means "first-last" but can still be modified by /step
*/
num1 = low;
num2 = high;
ch = get_char(file);
if (ch == EOF)
return (EOF);
}
else {
ch = get_number(&num1, low, names, ch, file, ",- \t\n");
if (ch == EOF)
return (EOF);
if (ch != '-') {
/* not a range, it's a single number.
*/
if (EOF == set_element(bits, low, high, num1)) {
unget_char(ch, file);
return (EOF);
}
return (ch);
}
else {
/* eat the dash
*/
ch = get_char(file);
if (ch == EOF)
return (EOF);
/* get the number following the dash
*/
ch = get_number(&num2, low, names, ch, file, "/, \t\n");
if (ch == EOF || num1 > num2)
return (EOF);
}
}
/* check for step size
*/
if (ch == '/') {
/* eat the slash
*/
ch = get_char(file);
if (ch == EOF)
return (EOF);
/* get the step size -- note: we don't pass the
* names here, because the number is not an
* element id, it's a step size. 'low' is
* sent as a 0 since there is no offset either.
*/
ch = get_number(&num3, 0, PPC_NULL, ch, file, ", \t\n");
if (ch == EOF || num3 == 0)
return (EOF);
}
else {
/* no step. default==1.
*/
num3 = 1;
}
/* num1 (through i) will be validated by set_element() below, but num2
* and num3 are merely used as loop condition and increment, and must
* be validated separately.
*/
if (num2 < low || num2 > high || num3 > high)
return (EOF);
/* range. set all elements from num1 to num2, stepping
* by num3. (the step is a downward-compatible extension
* proposed conceptually by bob@acornrc, syntactically
* designed then implemented by paul vixie).
*/
for (i = num1; i <= num2; i += num3)
if (EOF == set_element(bits, low, high, i)) {
unget_char(ch, file);
return (EOF);
}
return (ch);
}
static int
get_number(int *numptr, int low, const char *names[], int ch, FILE * file,
const char *terms) {
char temp[MAX_TEMPSTR], *pc;
int len, i;
pc = temp;
len = 0;
/* first look for a number */
while (isdigit((unsigned char) ch)) {
if (++len >= MAX_TEMPSTR)
goto bad;
*pc++ = (char)ch;
ch = get_char(file);
}
*pc = '\0';
if (len != 0) {
/* got a number, check for valid terminator */
if (!strchr(terms, ch))
goto bad;
*numptr = atoi(temp);
return (ch);
}
/* no numbers, look for a string if we have any */
if (names) {
while (isalpha((unsigned char) ch)) {
if (++len >= MAX_TEMPSTR)
goto bad;
*pc++ = (char)ch;
ch = get_char(file);
}
*pc = '\0';
if (len != 0 && strchr(terms, ch)) {
for (i = 0; names[i] != NULL; i++) {
Debug(DPARS | DEXT,
("get_num, compare(%s,%s)\n", names[i], temp));
if (!strcasecmp(names[i], temp)) {
*numptr = i + low;
return (ch);
}
}
}
}
bad:
unget_char(ch, file);
return (EOF);
}
static int set_element(bitstr_t * bits, int low, int high, int number) {
Debug(DPARS | DEXT, ("set_element(?,%d,%d,%d)\n", low, high, number));
if (number < low || number > high)
return (EOF);
bit_set(bits, (number - low));
return (OK);
}
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