cronie/anacron/readtab.c
2019-08-06 18:08:05 +02:00

452 lines
12 KiB
C

/*
Anacron - run commands periodically
Copyright (C) 1998 Itai Tzur <itzur@actcom.co.il>
Copyright (C) 1999 Sean 'Shaleh' Perry <shaleh@debian.org>
Copyright (C) 2004 Pascal Hakim <pasc@redellipse.net>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
The GNU General Public License can also be found in the file
`COPYING' that comes with the Anacron source distribution.
*/
/* /etc/anacrontab parsing, and job sorting
*/
#include <string.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <obstack.h>
#include <limits.h>
#include <fnmatch.h>
#include <unistd.h>
#include <signal.h>
#include "global.h"
#include "matchrx.h"
static struct obstack input_o; /* holds input line */
static struct obstack tab_o; /* holds processed data read from anacrontab */
static FILE *tab;
job_rec **job_array;
int njobs; /* number of jobs to run */
static int jobs_read; /* number of jobs read */
static int line_num; /* current line in anacrontab */
static job_rec *last_job_rec; /* last job stored in memory, at the moment */
static env_rec *last_env_rec; /* last environment assignment stored */
static int random_number = 0;
/* some definitions for the obstack macros */
#define obstack_chunk_alloc xmalloc
#define obstack_chunk_free free
static void *
xmalloc (size_t size)
/* Just like standard malloc(), only never returns NULL. */
{
void * ptr;
ptr = malloc(size);
if (ptr == NULL)
die("Memory exhausted");
return ptr;
}
static int
conv2int(const char *s)
/* Return the int or -1 on over/under-flow
*/
{
long l;
errno = 0;
l = strtol(s, NULL, 10);
/* we use negative as error, so I am really returning unsigned int */
if (errno == ERANGE || l < 0 || l > INT_MAX) return - 1;
return (int)l;
}
static char *
read_tab_line (void)
/* Read one line and return a pointer to it.
Return NULL if no more lines.
*/
{
int c, prev=0;
if (feof(tab)) return NULL;
while (1)
{
c = getc(tab);
if ((c == '\n' && prev != '\\') || c == EOF)
{
if (0 != prev) obstack_1grow(&input_o, (char)prev);
break;
}
if ('\\' != prev && 0 != prev && '\n' != prev) obstack_1grow(&input_o, (char)prev);
else if ('\n' == prev) obstack_1grow(&input_o, ' ');
prev = c;
}
if (ferror(tab)) die_e("Error reading %s", anacrontab);
obstack_1grow(&input_o, '\0');
return obstack_finish(&input_o);
}
static int
job_arg_num(const char *ident)
/* Return the command-line-argument number referring to this job-identifier.
* If it isn't specified, return -1.
*/
{
int i, r;
for (i = 0; i < job_nargs; i++)
{
r = fnmatch(job_args[i], ident, 0);
if (r == 0) return i;
if (r != FNM_NOMATCH) die("fnmatch() error");
}
return - 1;
}
static void
register_env(const char *env_var, const char *value)
/* Store the environment assignment "env_var"="value" */
{
env_rec *er;
int var_len, val_len;
var_len = (int)strlen(env_var);
val_len = (int)strlen(value);
if (!var_len) {
return;
}
er = obstack_alloc(&tab_o, sizeof(env_rec));
if (er == NULL) {
die_e("Cannot allocate memory.");
}
er->assign = obstack_alloc(&tab_o, var_len + 1 + val_len + 1);
if (er->assign == NULL) {
die_e("Cannot allocate memory.");
}
strcpy(er->assign, env_var);
er->assign[var_len] = '=';
strcpy(er->assign + var_len + 1, value);
er->assign[var_len + 1 + val_len] = 0;
if (last_env_rec != NULL) last_env_rec->next = er;
else first_env_rec = er;
last_env_rec = er;
Debug(("on line %d: %s", line_num, er->assign));
}
static void
register_job(const char *periods, const char *delays,
const char *ident, char *command)
/* Store a job definition */
{
int period, delay;
job_rec *jr;
int ident_len, command_len;
ident_len = (int)strlen(ident);
command_len = (int)strlen(command);
jobs_read++;
period = conv2int(periods);
delay = conv2int(delays);
if (period < 0 || delay < 0)
{
complain("%s: number out of range on line %d, skipping",
anacrontab, line_num);
return;
}
jr = obstack_alloc(&tab_o, sizeof(job_rec));
if (jr == NULL) {
die_e("Cannot allocate memory.");
}
jr->period = period;
jr->named_period = 0;
delay += random_number;
jr->delay = delay;
jr->tab_line = line_num;
jr->ident = obstack_alloc(&tab_o, ident_len + 1);
if (jr->ident == NULL) {
die_e("Cannot allocate memory.");
}
strcpy(jr->ident, ident);
jr->arg_num = job_arg_num(ident);
jr->command = obstack_alloc(&tab_o, command_len + 1);
if (jr->command == NULL) {
die_e("Cannot allocate memory.");
}
strcpy(jr->command, command);
jr->job_pid = jr->mailer_pid = 0;
if (last_job_rec != NULL) last_job_rec->next = jr;
else first_job_rec = jr;
last_job_rec = jr;
jr->prev_env_rec = last_env_rec;
jr->next = NULL;
Debug(("Read job - period=%d, delay=%d, ident=%s, command=%s",
jr->period, jr->delay, jr->ident, jr->command));
}
static void
register_period_job(const char *periods, const char *delays,
const char *ident, char *command)
/* Store a job definition with a named period */
{
int delay;
job_rec *jr;
int ident_len, command_len;
ident_len = (int)strlen(ident);
command_len = (int)strlen(command);
jobs_read++;
delay = conv2int(delays);
if (delay < 0)
{
complain("%s: number out of range on line %d, skipping",
anacrontab, line_num);
return;
}
jr = obstack_alloc(&tab_o, sizeof(job_rec));
if (jr == NULL) {
die_e("Cannot allocate memory.");
}
if (!strncmp ("@monthly", periods, 8)) {
jr->named_period = 1;
} else if (!strncmp("@yearly", periods, 7) || !strncmp("@annually", periods, 9) || !strncmp(/* backwards compat misspelling */"@annualy", periods, 8)) {
jr->named_period = 2;
} else if (!strncmp ("@daily", periods, 6)) {
jr->named_period = 3;
} else if (!strncmp ("@weekly", periods, 7)) {
jr->named_period = 4;
} else {
complain("%s: Unknown named period on line %d, skipping",
anacrontab, line_num);
}
jr->period = 0;
delay += random_number;
jr->delay = delay;
jr->tab_line = line_num;
jr->ident = obstack_alloc(&tab_o, ident_len + 1);
if (jr->ident == NULL) {
die_e("Cannot allocate memory.");
}
strcpy(jr->ident, ident);
jr->arg_num = job_arg_num(ident);
jr->command = obstack_alloc(&tab_o, command_len + 1);
if (jr->command == NULL) {
die_e("Cannot allocate memory.");
}
strcpy(jr->command, command);
jr->job_pid = jr->mailer_pid = 0;
if (last_job_rec != NULL) last_job_rec->next = jr;
else first_job_rec = jr;
last_job_rec = jr;
jr->prev_env_rec = last_env_rec;
jr->next = NULL;
Debug(("Read job - period %d, delay=%d, ident%s, command=%s",
jr->named_period, jr->delay, jr->ident, jr->command));
}
static long int
unbiased_rand(long int max)
{
long int rn;
long int divisor;
divisor = RAND_MAX / (max + 1);
do {
rn = random() / divisor;
} while (rn > max);
return rn;
}
static void
parse_tab_line(char *line)
{
int r;
char *env_var;
char *value;
char *periods;
char *delays;
char *ident;
char *command;
char *from;
char *to;
char *pref_hour;
/* an empty line? */
r = match_rx("^[ \t]*($|#)", line, 0);
if (r == -1) goto reg_err;
if (r)
{
Debug(("line %d empty", line_num));
return;
}
/* an environment assignment? */
r = match_rx("^[ \t]*([^ \t=]+)[ \t]*=(.*)$", line, 2,
&env_var, &value);
if (r == -1) goto reg_err;
if (r)
{
if (strncmp(env_var, "START_HOURS_RANGE", 17) == 0)
{
r = match_rx("^([[:digit:]]+)-([[:digit:]]+)$", value, 2, &from, &to);
if (r == -1) goto reg_err;
if (r == 0) goto reg_invalid;
range_start = atoi(from);
range_stop = atoi(to);
if (range_stop < range_start) {
range_start = 0; range_stop = 0;
goto reg_invalid;
}
Debug(("Jobs will start in the %02d:00-%02d:00 range.", range_start, range_stop));
}
else if (strncmp(env_var, "RANDOM_DELAY", 12) == 0) {
r = match_rx("^([[:digit:]]+)$", value, 0);
if (r == -1) goto reg_err;
if (r == 0) goto reg_invalid;
random_number = (int)unbiased_rand(atoi(value));
Debug(("Randomized delay set: %d", random_number));
}
else if (strncmp(env_var, "PREFERRED_HOUR", 14) == 0) {
r = match_rx("^([[:digit:]]+)$", value, 1, &pref_hour);
if (r == -1) goto reg_err;
if (r) {
preferred_hour = atoi(pref_hour);
if ((preferred_hour < 0) || (preferred_hour > 24)) {
preferred_hour = -1;
goto reg_invalid;
}
}
}
register_env(env_var, value);
return;
}
/* a job? */
r = match_rx("^[ \t]*([[:digit:]]+)[ \t]+([[:digit:]]+)[ \t]+"
"([^ \t/]+)[ \t]+([^ \t].*)$",
line, 4, &periods, &delays, &ident, &command);
if (r == -1) goto reg_err;
if (r)
{
register_job(periods, delays, ident, command);
return;
}
/* A period job? */
r = match_rx("^[ \t]*(@[^ \t]+)[ \t]+([[:digit:]]+)[ \t]+"
"([^ \t/]+)[ \t]+([^ \t].*)$",
line, 4, &periods, &delays, &ident, &command);
if (r == -1) goto reg_err;
if (r)
{
register_period_job(periods, delays, ident, command);
return;
}
reg_invalid:
complain("Invalid syntax in %s on line %d - skipping this line",
anacrontab, line_num);
return;
reg_err:
die("Regex error reading %s", anacrontab);
}
void
read_tab(int cwd)
/* Read the anacrontab file into memory */
{
char *tab_line;
first_job_rec = last_job_rec = NULL;
first_env_rec = last_env_rec = NULL;
jobs_read = 0;
line_num = 0;
/* Open the anacrontab file */
if (fchdir(cwd)) die_e("Can't chdir to original cwd");
tab = fopen(anacrontab, "r");
if (chdir(spooldir)) die_e("Can't chdir to %s", spooldir);
if (tab == NULL) die_e("Error opening %s", anacrontab);
/* Initialize the obstacks */
obstack_init(&input_o);
obstack_init(&tab_o);
while ((tab_line = read_tab_line()) != NULL)
{
line_num++;
parse_tab_line(tab_line);
obstack_free(&input_o, tab_line);
}
if (fclose(tab)) die_e("Error closing %s", anacrontab);
}
static int
execution_order(const job_rec **job1, const job_rec **job2)
/* Comparison function for sorting the jobs.
*/
{
int d;
d = (*job1)->arg_num - (*job2)->arg_num;
if (d != 0 && now) return d;
d = (*job1)->delay - (*job2)->delay;
if (d != 0) return d;
d = (*job1)->tab_line - (*job2)->tab_line;
return d;
}
void
arrange_jobs(void)
/* Make an array of pointers to jobs that are going to be executed,
* and arrange them in the order of execution.
* Also lock these jobs.
*/
{
job_rec *j;
j = first_job_rec;
njobs = 0;
while (j != NULL)
{
if (j->arg_num != -1 && (update_only || testing_only || consider_job(j)))
{
njobs++;
obstack_grow(&tab_o, &j, sizeof(j));
}
j = j->next;
}
job_array = obstack_finish(&tab_o);
/* sort the jobs */
qsort(job_array, (size_t)njobs, sizeof(*job_array),
(int (*)(const void *, const void *))execution_order);
}