proto_cron_crontab.c

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/*
 *   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 St, Fifth Floor, Boston, MA 02110-1301, USA
 */
 
/**
 * $Id: 03d6dfd8cf276253d36f3a0d802c61ad14cbb0ed $
 * @file proto_cron_crontab.c
 * @brief Generate crontab events.
 *
 * @copyright 2021 Network RADIUS SAS (legal@networkradius.com)
 */
#include <netdb.h>
#include <fcntl.h>
#include <freeradius-devel/server/protocol.h>
#include <freeradius-devel/io/application.h>
#include <freeradius-devel/io/listen.h>
#include <freeradius-devel/io/schedule.h>
 
#include "proto_cron.h"
 
extern fr_app_io_t proto_cron_crontab;
 
typedef struct proto_cron_tab_s proto_cron_crontab_t;
 
typedef struct {
        fr_event_list_t                 *el;                    //!< event list
        fr_network_t                    *nr;                    //!< network handler
 
        char const                      *name;                  //!< socket name
 
        proto_cron_crontab_t const      *inst;
 
        fr_event_timer_t const          *ev;                    //!< for writing statistics
 
        fr_listen_t                     *parent;                //!< master IO handler
 
        fr_time_t                       recv_time;              //!< when the timer hit.
 
        bool                            suspended;              //!< we suspend reading from the FD.
        bool                            bootstrap;              //!< get it started
} proto_cron_crontab_thread_t;
 
typedef struct {
        unsigned int    min;
        unsigned int    max;
 
        bool            wildcard;
        size_t          offset;
 
        uint64_t        fields;
} cron_tab_t;
 
struct proto_cron_tab_s {
        proto_cron_t                    *parent;
 
        CONF_SECTION                    *cs;                    //!< our configuration
 
        char const                      *filename;              //!< where to read input packet from
        fr_pair_list_t                  pair_list;              //!< for input packet
 
        int                             code;
        char const                      *spec;                  //!< crontab spec
 
        cron_tab_t                      tab[5];
 
        fr_client_t                     *client;                //!< static client
};
 
 
static int time_parse(TALLOC_CTX *ctx, void *out, UNUSED void *parent, CONF_ITEM *ci, conf_parser_t const *rule);
 
static const conf_parser_t crontab_listen_config[] = {
        { FR_CONF_OFFSET_FLAGS("filename", CONF_FLAG_FILE_INPUT | CONF_FLAG_REQUIRED | CONF_FLAG_NOT_EMPTY, proto_cron_crontab_t, filename) },
 
        { FR_CONF_OFFSET_FLAGS("timespec", CONF_FLAG_NOT_EMPTY | CONF_FLAG_REQUIRED, proto_cron_crontab_t, spec),
                        .func = time_parse },
 
        CONF_PARSER_TERMINATOR
};
 
/*
 *      Parse a basic field with sanity checks.
 */
static int parse_field(CONF_ITEM *ci, char const **start, char const *name,
                       cron_tab_t *tab, unsigned int min, unsigned int max, size_t offset)
{
        char const *p;
        char *end = NULL;
        unsigned int num, next, step, last = 0;
        bool last_is_set = false;
        bool wildcard = false;
        unsigned int i;
        uint64_t fields = 0;
 
        p = *start;
        fr_skip_whitespace(p);
 
        if (!*p) {
                cf_log_err(ci, "Missing field for %s", name);
                return -1;
        }
 
        tab->min = min;
        tab->max = max;
        tab->offset = offset;
        tab->fields = 0;
 
        /*
         *      See 'man 5 crontab' for the format.
         */
        while (p) {
                /*
                 *      Allow wildcards, but only once.
                 */
                if (*p == '*') {
                        if (wildcard) {
                                cf_log_err(ci, "Cannot use two wildcards for %s at %s", name, p);
                                return -1;
                        }
 
                        end = UNCONST(char *, p) + 1;
                        wildcard = true;
                        num = min;
                        next = max;
                        goto check_step;
                }
 
                /*
                 *      If there's already a "*", we can't have another one.
                 */
                if (wildcard) {
                        cf_log_err(ci, "Cannot use wildcard and numbers for %s at %s", name, p);
                        return -1;
                }
 
                /*
                 *      If it's not a wildcard, it MUST be a number,
                 *      which is between min and max.
                 */
                num = strtoul(p, &end, 10);
                if ((num < min) || (num > max)) {
                        cf_log_err(ci, "Number is invalid or out of bounds (%d..%d) for %s at %s",
                                   min, max, name, p);
                        return -1;
                }
 
                /*
                 *      Don't allow the same number to be specified
                 *      multiple times.
                 */
                if (!last_is_set) {
                        last_is_set = true;
 
                } else if (num <= last) {
                                cf_log_err(ci, "Number overlaps with previous value of %u, for %s at %s",
                                           last, name, p);
                                return -1;
                }
                last = num;
 
                /*
                 *      Ranges are allowed, with potential steps
                 */
                if (*end == '-') {
                        p = end + 1;
                        next = strtoul(p, &end, 10);
                        if (next <= num) {
                                cf_log_err(ci, "End of range number overlaps with previous value of %u, for %s at %s",
                                           num, name, p);
                                return -1;
                        }
 
                        if (next > max) {
                                cf_log_err(ci, "End of range number is invalid or out of bounds (%d..%d) for %s at %s",
                                           min, max, name, p);
                                return -1;
                        }
 
                check_step:
                        last = next;
 
                        /*
                         *      Allow /N
                         */
                        if (*end == '/') {
                                p = end + 1;
 
                                step = strtoul(p, &end, 10);
                                if (step >= max) {
                                        cf_log_err(ci, "Step value is invalid or out of bounds for %s at %s", name, p);
                                        return -1;
                                }
                        } else {
                                step = 1;
                        }
 
                        /*
                         *      Set the necessary bits.
                         */
                        for (i = num; i <= next; i += step) {
                                fields |= ((uint64_t) 1) << i;
                        }
                } /* end of range specifier */
 
                /*
                 *      We can specify multiple fields, separated by a comma.
                 */
                if (*end == ',') {
                        fields |= ((uint64_t) 1) << num;
                        p = end + 1;
                        continue;
                }
 
                /*
                 *      EOS or space is end of field.
                 */
                if (!(!*end || isspace((uint8_t) *end))) {
                        cf_log_err(ci, "Unexpected text for %s at %s", name, end);
                        return -1;
                }
 
                /*
                 *      We're at the end of the field, stop.
                 */
                break;
        }
 
        /*
         *      Set a wildcard, so we can skip a lot of the later
         *      logic.
         */
        tab->wildcard = true;
        for (i = min; i <= max; i++) {
                if ((fields & (((uint64_t) 1) << i)) == 0) {
                        tab->wildcard = false;
                        break;
                }
        }
 
        tab->fields = fields;
        *start = end;
        return 0;
}
 
/*
 *      Special names, including our own extensions.
 */
static fr_table_ptr_sorted_t time_names[] = {
        { L("annually"),        "0 0 1 1 *" },
        { L("daily"),           "0 0 * * *" },
        { L("hourly"),          "0 * * * *" },
        { L("midnight"),        "0 0 * * *" },
        { L("monthly"),         "0 0 1 * *" },
//      { L("reboot"),          "+" },
        { L("weekly"),          "0 0 * * 0" },
        { L("yearly"),          "0 0 1 1 *" },
};
static size_t time_names_len = NUM_ELEMENTS(time_names);
 
/** Wrapper around dl_instance which checks the syntax of a cron job
 *
 * @param[in] ctx       to allocate data in (instance of proto_cron).
 * @param[out] out      Where to write a dl_module_inst_t containing the module handle and instance.
 * @param[in] parent    Base structure address.
 * @param[in] ci        #CONF_PAIR specifying the name of the type module.
 * @param[in] rule      unused.
 * @return
 *      - 0 on success.
 *      - -1 on failure.
 */
static int time_parse(UNUSED TALLOC_CTX *ctx, void *out, void *parent, CONF_ITEM *ci, UNUSED conf_parser_t const *rule)
{
        proto_cron_crontab_t            *inst = talloc_get_type_abort(parent, proto_cron_crontab_t);
        CONF_PAIR               *cp = cf_item_to_pair(ci);
        char const              *value = cf_pair_value(cp);
        char const              *p;
 
        p = value;
 
        /*
         *      Check for special names.
         */
        if (*p == '@') {
                p = fr_table_value_by_str(time_names, p + 1, NULL);
                if (!p) {
                        cf_log_err(ci, "Invalid time name '%s'", value);
                        return -1;
                }
 
                /*
                 *      Over-write the special names with standard
                 *      ones, so that the rest of the parser is simpler.
                 */
                *((char const **) out) = p;
                return 0;
        }
 
        *((char const **) out) = value;
 
        if (parse_field(ci, &p, "minute",       &inst->tab[0], 0, 59, offsetof(struct tm, tm_min)) < 0) return -1;
        if (parse_field(ci, &p, "hour",         &inst->tab[1], 0, 59, offsetof(struct tm, tm_hour)) < 0) return -1;
        if (parse_field(ci, &p, "day of month", &inst->tab[2], 1, 31, offsetof(struct tm, tm_mday)) < 0) return -1;
        if (parse_field(ci, &p, "month",        &inst->tab[3], 1,12, offsetof(struct tm, tm_mon)) < 0) return -1;
        if (parse_field(ci, &p, "day of week",  &inst->tab[4], 0, 6, offsetof(struct tm, tm_wday)) < 0) return -1;
 
        fr_skip_whitespace(p);
 
        if (*p) {
                cf_log_err(ci, "Unexpected text after cron time specification");
                return -1;
        }
 
        return 0;
}
 
static ssize_t mod_read(fr_listen_t *li, void **packet_ctx, fr_time_t *recv_time_p, uint8_t *buffer, size_t buffer_len, size_t *leftover)
{
        proto_cron_crontab_t const      *inst = talloc_get_type_abort_const(li->app_io_instance, proto_cron_crontab_t);
        proto_cron_crontab_thread_t     *thread = talloc_get_type_abort(li->thread_instance, proto_cron_crontab_thread_t);
        fr_io_address_t                 *address, **address_p;
 
        *leftover = 0;
 
        /*
         *      Suspend all activity on the FD, because we let the
         *      timers do their work.
         */
        if (!thread->suspended) {
                static fr_event_update_t const pause_read[] = {
                        FR_EVENT_SUSPEND(fr_event_io_func_t, read),
                        { 0 }
                };
 
                if (fr_event_filter_update(thread->el, li->fd, FR_EVENT_FILTER_IO, pause_read) < 0) {
                        fr_assert(0);
                }
 
                /*
                 *      Don't read from it the first time.
                 */
                thread->suspended = true;
                return 0;
        }
 
        /*
         *      Where the addresses should go.  This is a special case
         *      for proto_radius.
         */
        address_p = (fr_io_address_t **) packet_ctx;
        address = *address_p;
 
        memset(address, 0, sizeof(*address));
        address->socket.inet.src_ipaddr.af = AF_INET;
        address->socket.inet.dst_ipaddr.af = AF_INET;
        address->radclient = inst->client;
 
        *recv_time_p = thread->recv_time;
 
        if (buffer_len < 1) {
                DEBUG2("proto_cron_tab read buffer is too small for input packet");
                return 0;
        }
 
        buffer[0] = 0;
 
        /*
         *      Print out what we received.
         */
        DEBUG2("proto_cron_crontab - reading packet for %s",
               thread->name);
 
        return 1;
}
 
 
static ssize_t mod_write(UNUSED fr_listen_t *li, UNUSED void *packet_ctx, UNUSED fr_time_t request_time,
                         UNUSED uint8_t *buffer, size_t buffer_len, UNUSED size_t written)
{
        return buffer_len;
}
 
 
/** Open a crontab listener
 *
 */
static int mod_open(fr_listen_t *li)
{
        proto_cron_crontab_t const      *inst = talloc_get_type_abort_const(li->app_io_instance, proto_cron_crontab_t);
        proto_cron_crontab_thread_t     *thread = talloc_get_type_abort(li->thread_instance, proto_cron_crontab_thread_t);
 
        fr_ipaddr_t                     ipaddr;
 
        /*
         *      We never read or write to this file, but we need a
         *      readable FD in order to bootstrap the process.
         */
        if (inst->filename == NULL) return -1;
        li->fd = open(inst->filename, O_RDONLY);
 
        memset(&ipaddr, 0, sizeof(ipaddr));
        ipaddr.af = AF_INET;
        li->app_io_addr = fr_socket_addr_alloc_inet_src(li, IPPROTO_UDP, 0, &ipaddr, 0);
 
        fr_assert((cf_parent(inst->cs) != NULL) && (cf_parent(cf_parent(inst->cs)) != NULL));   /* listen { ... } */
 
        thread->name = talloc_typed_asprintf(thread, "cron_crontab from filename %s", inst->filename);
        thread->parent = talloc_parent(li);
 
        return 0;
}
 
 
/** Decode the packet
 *
 */
static int mod_decode(void const *instance, request_t *request, UNUSED uint8_t *const data, UNUSED size_t data_len)
{
        proto_cron_crontab_t const      *inst = talloc_get_type_abort_const(instance, proto_cron_crontab_t);
        fr_io_track_t const     *track = talloc_get_type_abort_const(request->async->packet_ctx, fr_io_track_t);
        fr_io_address_t const   *address = track->address;
 
        /*
         *      Set the request dictionary so that we can do
         *      generic->protocol attribute conversions as
         *      the request runs through the server.
         */
        request->dict = inst->parent->dict;
 
        /*
         *      Hacks for now until we have a lower-level decode routine.
         */
        if (inst->code) request->packet->code = inst->code;
        request->packet->id = fr_rand() & 0xff;
        request->reply->id = request->packet->id;
        memset(request->packet->vector, 0, sizeof(request->packet->vector));
 
        request->packet->data = talloc_zero_array(request->packet, uint8_t, 1);
        request->packet->data_len = 1;
 
        (void) fr_pair_list_copy(request->request_ctx, &request->request_pairs, &inst->pair_list);
 
        /*
         *      Set the rest of the fields.
         */
        request->client = UNCONST(fr_client_t *, address->radclient);
 
        request->packet->socket = address->socket;
        fr_socket_addr_swap(&request->reply->socket, &address->socket);
 
        REQUEST_VERIFY(request);
 
        return 0;
}
 
/*
 *      Get the next time interval.
 *
 *      Set the relevant "struct tm" field to its next value, and
 *      return "true"
 *
 *      Set the relevant "struct tm" field to its minimum value, and
 *      return "false".
 */
static bool get_next(struct tm *tm, cron_tab_t const *tab)
{
        unsigned int i, num = *(int *) (((uint8_t *) tm) + tab->offset);
 
        num++;
 
        /*
         *      Simplified process for "do each thing".
         */
        if (tab->wildcard) {
                if (num < tab->max) goto done;
                goto next;
        }
 
        /*
         *      See when the next time interval is.
         */
        for (i = num; i <= tab->max; i++) {
                if ((tab->fields & (((uint64_t) 1) << i)) != 0) {
                        num = i;
                        break;
                }
        }
 
        /*
         *      We ran out of time intervals.  Reset this field to the
         *      minimum, and ask the caller to go to the next
         *      interval.
         */
        if (i > tab->max) {
        next:
                *(int *) (((uint8_t *) tm) + tab->offset) = tab->min;
                return false;
        }
 
done:
        *(int *) (((uint8_t *) tm) + tab->offset) = num;
        return true;
}
 
/*
 *      Called when tm.tm_sec == 0.  If it isn't zero, then it means
 *      that the timer is late, and we treat it as if tm.tm_sec == 0.
 */
static void do_cron(fr_event_list_t *el, fr_time_t now, void *uctx)
{
        proto_cron_crontab_thread_t     *thread = uctx;
        struct tm tm;
        time_t start = time(NULL), end;
 
        thread->recv_time = now;
 
        localtime_r(&start, &tm);
 
        /*
         *      For now, ignore "day of week".  If the "day of week"
         *      is a wildcard, then ignore it.  Otherwise, calculate
         *      next based on "day of month" and also "day of week",
         *      and then return the time which is closer.
         */
        tm.tm_sec = 0;
        if (get_next(&tm, &thread->inst->tab[0])) goto set; /* minutes */
        if (get_next(&tm, &thread->inst->tab[1])) goto set; /* hours */
 
        /*
         *      If we're running it every day of the week, just pay
         *      attention to the day of the month.
         */
        if (thread->inst->tab[4].wildcard) {
                if (get_next(&tm, &thread->inst->tab[2])) goto set; /* days */
 
                if (get_next(&tm, &thread->inst->tab[3])) goto set; /* month */
 
                /*
                 *      We ran out of months, so we have to go to the next year.
                 */
                tm.tm_year++;
 
        } else {
                /*
                 *      Pick the earliest of "day of month" and "day of week".
                 */
                struct tm m_tm = tm;
                struct tm w_tm = tm;
                int tm_wday = tm.tm_wday;
                bool m_day = get_next(&m_tm, &thread->inst->tab[2]);
                bool w_day = get_next(&w_tm, &thread->inst->tab[4]);
                time_t m_time;
                time_t w_time;
 
                /*
                 *      No more days this week.  Go to the
                 *      start of the next week.
                 */
                if (!w_day) {
                        w_tm = tm;
                        w_tm.tm_mday += (6 - tm_wday);
 
                        (void) mktime(&w_tm); /* normalize it */
 
                        tm_wday = w_tm.tm_wday;
#ifndef NDEBUG
                        w_day = get_next(&w_tm, &thread->inst->tab[4]);
                        fr_assert(w_day);
#else
                        (void) get_next(&w_tm, &thread->inst->tab[4]);
#endif
                }
 
                /*
                 *      Next weekday is ignored by mktime(), so we
                 *      have to update the day of the month with the
                 *      new value.
                 *
                 *      Note that mktime() will also normalize the
                 *      values, so we can just add "28 + 5" for a day
                 *      of the month, and mktime() will normalize that
                 *      to the correct day for the next month.
                 */
                fr_assert(tm.tm_wday > tm_wday);
                w_tm.tm_mday += tm.tm_wday - tm_wday;
 
                /*
                 *      No more days this month, go to the next month,
                 *      and potentially the next year.
                 */
                if (!m_day && !get_next(&m_tm, &thread->inst->tab[3])) m_tm.tm_year++;
 
                /*
                 *      We now have 2 times, one for "day of month"
                 *      and another for "day of week".  Pick the
                 *      earliest one.
                 */
                m_time = mktime(&m_tm);
                w_time = mktime(&w_tm);
 
                if (m_time < w_time) {
                        end = m_time;
                } else {
                        end = w_time;
                }
 
                goto use_time;
        }
 
set:
        end = mktime(&tm);
        fr_assert(end >= start);
 
use_time:
        if (DEBUG_ENABLED2) {
                char buffer[256];
 
                ctime_r(&end, buffer);
                DEBUG("TIMER - virtual server %s next cron is at %s, in %ld seconds",
                      cf_section_name2(thread->inst->parent->server_cs), buffer, end - start);
        }
 
        if (fr_event_timer_at(thread, el, &thread->ev, fr_time_add(now, fr_time_delta_from_sec(end - start)),
                              do_cron, thread) < 0) {
                fr_assert(0);
        }
 
        /*
         *      Don't run the event the first time.
         */
        if (thread->bootstrap) {
                thread->bootstrap = false;
                return;
        }
 
        /*
         *      Now that we've set the timer, tell the network side to
         *      call our read routine.
         */
        fr_network_listen_read(thread->nr, thread->parent);
}
 
/** Set the event list for a new socket
 *
 * @param[in] li the listener
 * @param[in] el the event list
 * @param[in] nr context from the network side
 */
static void mod_event_list_set(fr_listen_t *li, fr_event_list_t *el, void *nr)
{
        proto_cron_crontab_t const       *inst = talloc_get_type_abort_const(li->app_io_instance, proto_cron_crontab_t);
        proto_cron_crontab_thread_t     *thread = talloc_get_type_abort(li->thread_instance, proto_cron_crontab_thread_t);
 
        thread->el = el;
        thread->nr = nr;
        thread->inst = inst;
        thread->bootstrap = true;
 
        do_cron(el, fr_time(), thread);
}
 
static char const *mod_name(fr_listen_t *li)
{
        proto_cron_crontab_thread_t     *thread = talloc_get_type_abort(li->thread_instance, proto_cron_crontab_thread_t);
 
        return thread->name;
}
 
 
static int mod_bootstrap(module_inst_ctx_t const *mctx)
{
        proto_cron_crontab_t    *inst = talloc_get_type_abort(mctx->inst->data, proto_cron_crontab_t);
        CONF_SECTION            *conf = mctx->inst->data;
        dl_module_inst_t const  *dl_inst;
 
        /*
         *      Find the dl_module_inst_t holding our instance data
         *      so we can find out what the parent of our instance
         *      was.
         */
        dl_inst = dl_module_instance_by_data(inst);
        fr_assert(dl_inst);
 
        inst->parent = talloc_get_type_abort(dl_inst->parent->data, proto_cron_t);
 
        inst->cs = conf;
 
        return 0;
}
 
static fr_client_t *mod_client_find(fr_listen_t *li, UNUSED fr_ipaddr_t const *ipaddr, UNUSED int ipproto)
{
        proto_cron_crontab_t const       *inst = talloc_get_type_abort_const(li->app_io_instance, proto_cron_crontab_t);
 
        return inst->client;
}
 
 
static int mod_instantiate(module_inst_ctx_t const *mctx)
{
        proto_cron_crontab_t    *inst = talloc_get_type_abort(mctx->inst->data, proto_cron_crontab_t);
        CONF_SECTION            *conf = mctx->inst->data;
        fr_client_t             *client;
        fr_pair_t               *vp;
        FILE                    *fp;
        bool                    done = false;
 
        fr_pair_list_init(&inst->pair_list);
        inst->client = client = talloc_zero(inst, fr_client_t);
        if (!inst->client) return 0;
 
        client->ipaddr.af = AF_INET;
        client->src_ipaddr = client->ipaddr;
 
        client->longname = client->shortname = inst->filename;
        client->secret = talloc_strdup(client, "testing123");
        client->nas_type = talloc_strdup(client, "load");
        client->use_connected = false;
 
        fp = fopen(inst->filename, "r");
        if (!fp) {
                cf_log_err(conf, "Failed opening %s - %s",
                           inst->filename, fr_syserror(errno));
                return -1;
        }
 
        if (fr_pair_list_afrom_file(inst, inst->parent->dict, &inst->pair_list, fp, &done) < 0) {
                cf_log_perr(conf, "Failed reading %s", inst->filename);
                fclose(fp);
                return -1;
        }
 
        fclose(fp);
 
        vp = fr_pair_find_by_da(&inst->pair_list, NULL, inst->parent->attr_packet_type);
        if (vp) inst->code = vp->vp_uint32;
 
        return 0;
}
 
fr_app_io_t proto_cron_crontab = {
        .common = {
                .magic                  = MODULE_MAGIC_INIT,
                .name                   = "cron_crontab",
                .config                 = crontab_listen_config,
                .inst_size              = sizeof(proto_cron_crontab_t),
                .thread_inst_size       = sizeof(proto_cron_crontab_thread_t),
                .bootstrap              = mod_bootstrap,
                .instantiate            = mod_instantiate
        },
        .default_message_size   = 4096,
        .track_duplicates       = false,
 
        .open                   = mod_open,
        .read                   = mod_read,
        .write                  = mod_write,
        .event_list_set         = mod_event_list_set,
        .client_find            = mod_client_find,
        .get_name               = mod_name,
 
        .decode                 = mod_decode,
};