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authorDavid Oberhollenzer <david.oberhollenzer@tele2.at>2018-09-16 15:38:45 +0200
committerDavid Oberhollenzer <david.oberhollenzer@tele2.at>2018-09-17 14:53:19 +0200
commit5cd5f48f765f00b81786c6f569314474a91a06b8 (patch)
treef7cbda4a0f09ebffd8efb71295914a22557cc2b8 /lib/cron/rdcron.c
parent481744a2ba4d9b795918d3bc0767321e05e10bbd (diff)
Add helper library for cron configuration
Signed-off-by: David Oberhollenzer <david.oberhollenzer@tele2.at>
Diffstat (limited to 'lib/cron/rdcron.c')
-rw-r--r--lib/cron/rdcron.c503
1 files changed, 503 insertions, 0 deletions
diff --git a/lib/cron/rdcron.c b/lib/cron/rdcron.c
new file mode 100644
index 0000000..42936ce
--- /dev/null
+++ b/lib/cron/rdcron.c
@@ -0,0 +1,503 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * Copyright (C) 2018 - David Oberhollenzer
+ *
+ * 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 3 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, see <https://www.gnu.org/licenses/>.
+ */
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+#include <limits.h>
+#include <stdio.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <ctype.h>
+#include <pwd.h>
+#include <grp.h>
+
+#include "crontab.h"
+#include "libcfg.h"
+#include "util.h"
+
+
+static const enum_map_t weekday[] = {
+ { "MON", 1 },
+ { "TUE", 2 },
+ { "WED", 3 },
+ { "THU", 4 },
+ { "FRI", 5 },
+ { "SAT", 6 },
+ { "SUN", 0 },
+};
+
+static const enum_map_t month[] = {
+ { "JAN", 1 },
+ { "FEB", 2 },
+ { "MAR", 3 },
+ { "APR", 4 },
+ { "MAY", 5 },
+ { "JUN", 6 },
+ { "JUL", 7 },
+ { "AUG", 8 },
+ { "SEP", 9 },
+ { "OCT", 10 },
+ { "NOV", 11 },
+ { "DEC", 12 },
+};
+
+static const struct {
+ const char *macro;
+ crontab_t tab;
+} intervals[] = {
+ {
+ .macro = "yearly",
+ .tab = {
+ .minute = 0x01,
+ .hour = 0x01,
+ .dayofmonth = 0x01,
+ .month = 0x01,
+ .dayofweek = 0xFF
+ },
+ }, {
+ .macro = "annually",
+ .tab = {
+ .minute = 0x01,
+ .hour = 0x01,
+ .dayofmonth = 0x01,
+ .month = 0x01,
+ .dayofweek = 0xFF
+ },
+ }, {
+ .macro = "monthly",
+ .tab = {
+ .minute = 0x01,
+ .hour = 0x01,
+ .dayofmonth = 0x01,
+ .month = 0xFFFF,
+ .dayofweek = 0xFF
+ },
+ }, {
+ .macro = "weekly",
+ .tab = {
+ .minute = 0x01,
+ .hour = 0x01,
+ .dayofmonth = 0xFFFFFFFF,
+ .month = 0xFFFF,
+ .dayofweek = 0x01
+ },
+ }, {
+ .macro = "daily",
+ .tab = {
+ .minute = 0x01,
+ .hour = 0x01,
+ .dayofmonth = 0xFFFFFFFF,
+ .month = 0xFFFF,
+ .dayofweek = 0xFF
+ },
+ }, {
+ .macro = "hourly",
+ .tab = {
+ .minute = 0x01,
+ .hour = 0xFFFFFFFF,
+ .dayofmonth = 0xFFFFFFFF,
+ .month = 0xFFFF,
+ .dayofweek = 0xFF
+ },
+ },
+};
+
+/*****************************************************************************/
+
+static int try_unescape(char *arg, rdline_t *rd)
+{
+ if (unescape(arg)) {
+ fprintf(stderr, "%s: %zu: malformed string constant\n",
+ rd->filename, rd->lineno);
+ return -1;
+ }
+ return 0;
+}
+
+static char *try_strdup(const char *str, rdline_t *rd)
+{
+ char *out = strdup(str);
+
+ if (out == NULL) {
+ fprintf(stderr, "%s: %zu: out of memory\n",
+ rd->filename, rd->lineno);
+ }
+ return out;
+}
+
+static char *readnum(char *line, int *out, int minval, int maxval,
+ const enum_map_t *mnemonic, rdline_t *rd)
+{
+ int i, temp, value = 0;
+ const enum_map_t *ev;
+
+ if (!isdigit(*line)) {
+ if (!mnemonic)
+ goto fail_mn;
+
+ for (i = 0; isalnum(line[i]); ++i)
+ ;
+ if (i == 0)
+ goto fail_mn;
+
+ temp = line[i];
+ line[i] = '\0';
+ ev = enum_by_name(mnemonic, line);
+ if (!ev) {
+ fprintf(stderr, "%s: %zu: unexpected '%s'",
+ rd->filename, rd->lineno, line);
+ }
+ line[i] = temp;
+ if (!ev)
+ return NULL;
+ *out = ev->value;
+ return line + i;
+ }
+
+ while (isdigit(*line)) {
+ i = ((*(line++)) - '0');
+ if (value > (maxval - i) / 10)
+ goto fail_of;
+ value = value * 10 + i;
+ }
+
+ if (value < minval)
+ goto fail_uf;
+
+ *out = value;
+ return line;
+fail_of:
+ fprintf(stderr, "%s: %zu: value exceeds maximum (%d > %d)\n",
+ rd->filename, rd->lineno, value, maxval);
+ return NULL;
+fail_uf:
+ fprintf(stderr, "%s: %zu: value too small (%d < %d)\n",
+ rd->filename, rd->lineno, value, minval);
+ return NULL;
+fail_mn:
+ fprintf(stderr, "%s: %zu: expected numeric value",
+ rd->filename, rd->lineno);
+ return NULL;
+}
+
+static char *readfield(char *line, uint64_t *out, int minval, int maxval,
+ const enum_map_t *mnemonic, rdline_t *rd)
+{
+ int value, endvalue, step;
+ uint64_t v = 0;
+next:
+ if (*line == '*') {
+ ++line;
+ value = minval;
+ endvalue = maxval;
+ } else {
+ line = readnum(line, &value, minval, maxval, mnemonic, rd);
+ if (!line)
+ goto fail;
+
+ if (*line == '-') {
+ line = readnum(line + 1, &endvalue, minval, maxval,
+ mnemonic, rd);
+ if (!line)
+ goto fail;
+ } else {
+ endvalue = value;
+ }
+ }
+
+ if (endvalue < value)
+ goto fail;
+
+ if (*line == '/') {
+ line = readnum(line + 1, &step, 1, maxval + 1, NULL, rd);
+ if (!line)
+ goto fail;
+ } else {
+ step = 1;
+ }
+
+ while (value <= endvalue) {
+ v |= 1UL << (unsigned long)(value - minval);
+ value += step;
+ }
+
+ if (*line == ',' || *line == ' ') {
+ ++line;
+ goto next;
+ }
+
+ if (*line != '\0')
+ goto fail;
+
+ *out = v;
+ return line;
+fail:
+ fprintf(stderr, "%s: %zu: invalid time range expression\n",
+ rd->filename, rd->lineno);
+ return NULL;
+}
+
+/*****************************************************************************/
+
+static int cron_exec(void *user, char *arg, rdline_t *rd, int flags)
+{
+ crontab_t *cron = user;
+ exec_t *e, *end;
+ (void)flags;
+
+ e = calloc(1, sizeof(*e) + strlen(arg) + 1);
+ if (e == NULL) {
+ fprintf(stderr, "%s: %zu: out of memory\n",
+ rd->filename, rd->lineno);
+ return -1;
+ }
+
+ strcpy(e->args, arg);
+
+ e->argc = pack_argv(e->args);
+ if (e->argc < 0) {
+ fprintf(stderr, "%s: %zu: malformed string constant\n",
+ rd->filename, rd->lineno);
+ return -1;
+ }
+
+ if (cron->exec == NULL) {
+ cron->exec = e;
+ } else {
+ for (end = cron->exec; end->next != NULL; end = end->next)
+ ;
+ end->next = e;
+ }
+ return 0;
+}
+
+static int cron_hour(void *user, char *arg, rdline_t *rd, int flags)
+{
+ crontab_t *cron = user;
+ uint64_t value;
+ (void)flags;
+
+ if (!readfield(arg, &value, 0, 23, NULL, rd))
+ return -1;
+
+ cron->hour = value;
+ return 0;
+}
+
+static int cron_minute(void *user, char *arg, rdline_t *rd, int flags)
+{
+ crontab_t *cron = user;
+ uint64_t value;
+ (void)flags;
+
+ if (!readfield(arg, &value, 0, 59, NULL, rd))
+ return -1;
+
+ cron->minute = value;
+ return 0;
+}
+
+static int cron_dayofmonth(void *user, char *arg, rdline_t *rd, int flags)
+{
+ crontab_t *cron = user;
+ uint64_t value;
+ (void)flags;
+
+ if (!readfield(arg, &value, 1, 31, NULL, rd))
+ return -1;
+
+ cron->dayofmonth = value;
+ return 0;
+}
+
+static int cron_dayofweek(void *user, char *arg, rdline_t *rd, int flags)
+{
+ crontab_t *cron = user;
+ uint64_t value;
+ (void)flags;
+
+ if (!readfield(arg, &value, 0, 6, weekday, rd))
+ return -1;
+
+ cron->dayofweek = value;
+ return 0;
+}
+
+static int cron_month(void *user, char *arg, rdline_t *rd, int flags)
+{
+ crontab_t *cron = user;
+ uint64_t value;
+ (void)flags;
+
+ if (!readfield(arg, &value, 1, 12, month, rd))
+ return -1;
+
+ cron->month = value;
+ return 0;
+}
+
+static int cron_interval(void *user, char *arg, rdline_t *rd, int flags)
+{
+ crontab_t *cron = user;
+ size_t i;
+ (void)flags;
+
+ for (i = 0; i < ARRAY_SIZE(intervals); ++i) {
+ if (!strcmp(intervals[i].macro, arg)) {
+ cron->minute = intervals[i].tab.minute;
+ cron->hour = intervals[i].tab.hour;
+ cron->dayofmonth = intervals[i].tab.dayofmonth;
+ cron->month = intervals[i].tab.month;
+ cron->dayofweek = intervals[i].tab.dayofweek;
+ return 0;
+ }
+ }
+
+ fprintf(stderr, "%s: %zu: unknown interval '%s'\n",
+ rd->filename, rd->lineno, arg);
+ return -1;
+}
+
+static int cron_user(void *user, char *arg, rdline_t *rd, int flags)
+{
+ crontab_t *cron = user;
+ struct passwd *pwd;
+ bool isnumeric;
+ char *ptr;
+ int value;
+ (void)flags;
+
+ for (ptr = arg; isdigit(*ptr); ++ptr)
+ ;
+
+ isnumeric = (*ptr == '\0');
+ pwd = getpwnam(arg);
+
+ if (pwd == NULL && !isnumeric) {
+ fprintf(stderr, "%s: %zu: unknown user '%s'\n",
+ rd->filename, rd->lineno, arg);
+ return -1;
+ }
+
+ if (pwd != NULL) {
+ cron->uid = pwd->pw_uid;
+ } else {
+ if (readnum(arg, &value, 0, INT_MAX, NULL, rd))
+ return -1;
+ cron->uid = value;
+ }
+ return 0;
+}
+
+static int cron_group(void *user, char *arg, rdline_t *rd, int flags)
+{
+ crontab_t *cron = user;
+ struct group *group;
+ bool isnumeric;
+ char *ptr;
+ int value;
+ (void)flags;
+
+ for (ptr = arg; isdigit(*ptr); ++ptr)
+ ;
+
+ isnumeric = (*ptr == '\0');
+ group = getgrnam(arg);
+
+ if (group == NULL && !isnumeric) {
+ fprintf(stderr, "%s: %zu: unknown group '%s'\n",
+ rd->filename, rd->lineno, arg);
+ return -1;
+ }
+
+ if (group != NULL) {
+ cron->gid = group->gr_gid;
+ } else {
+ if (readnum(arg, &value, 0, INT_MAX, NULL, rd))
+ return -1;
+ cron->gid = value;
+ }
+ return 0;
+}
+
+static int cron_tty(void *user, char *arg, rdline_t *rd, int flags)
+{
+ crontab_t *cron = user;
+ (void)flags;
+
+ if (strncmp(arg, "truncate", 8) == 0 && isspace(arg[8])) {
+ cron->tty_truncate = 1;
+ arg += 8;
+ while (isspace(*arg))
+ ++arg;
+ }
+
+ if (try_unescape(arg, rd))
+ return -1;
+
+ cron->ctty = try_strdup(arg, rd);
+ return cron->ctty == NULL ? -1 : 0;
+}
+
+
+
+static const cfg_param_t cron_params[] = {
+ { "hour", 0, cron_hour },
+ { "minute", 0, cron_minute },
+ { "dayofmonth", 0, cron_dayofmonth },
+ { "dayofweek", 0, cron_dayofweek },
+ { "month", 0, cron_month },
+ { "interval", 0, cron_interval },
+ { "user", 0, cron_user },
+ { "group", 0, cron_group },
+ { "tty", 0, cron_tty },
+ { "exec", 1, cron_exec },
+};
+
+crontab_t *rdcron(int dirfd, const char *filename)
+{
+ crontab_t *cron;
+ rdline_t rd;
+ int fd, ret;
+
+ fd = openat(dirfd, filename, O_RDONLY);
+ if (fd < 0) {
+ perror(filename);
+ return NULL;
+ }
+
+ cron = calloc(1, sizeof(*cron));
+ if (cron == NULL) {
+ fputs("out of memory\n", stderr);
+ goto out;
+ }
+
+ cron->pid = -1;
+
+ rdline_init(&rd, fd, filename, 0, NULL);
+ ret = rdcfg(cron, &rd, cron_params, ARRAY_SIZE(cron_params), 0);
+ if (ret) {
+ delcron(cron);
+ cron = NULL;
+ }
+out:
+ close(fd);
+ return cron;
+}