/*      $OpenBSD: scheduler_proc.c,v 1.13 2024/11/21 13:42:22 claudio Exp $     */

/*
 * Copyright (c) 2013 Eric Faurot <eric@openbsd.org>
 *
 * 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 THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR 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.
 */

#include <errno.h>
#include <string.h>

#include "smtpd.h"
#include "log.h"

static struct imsgbuf    ibuf;
static struct imsg       imsg;
static size_t            rlen;
static char             *rdata;

static void
scheduler_proc_call(void)
{
        ssize_t n;

        if (imsgbuf_flush(&ibuf) == -1) {
                log_warn("warn: scheduler-proc: imsgbuf_flush");
                fatalx("scheduler-proc: exiting");
        }

        while (1) {
                if ((n = imsg_get(&ibuf, &imsg)) == -1) {
                        log_warn("warn: scheduler-proc: imsg_get");
                        break;
                }
                if (n) {
                        rlen = imsg.hdr.len - IMSG_HEADER_SIZE;
                        rdata = imsg.data;

                        if (imsg.hdr.type != PROC_SCHEDULER_OK) {
                                log_warnx("warn: scheduler-proc: bad response");
                                break;
                        }
                        return;
                }

                if ((n = imsgbuf_read(&ibuf)) == -1) {
                        log_warn("warn: scheduler-proc: imsgbuf_read");
                        break;
                }

                if (n == 0) {
                        log_warnx("warn: scheduler-proc: pipe closed");
                        break;
                }
        }

        fatalx("scheduler-proc: exiting");
}

static void
scheduler_proc_read(void *dst, size_t len)
{
        if (len > rlen) {
                log_warnx("warn: scheduler-proc: bad msg len");
                fatalx("scheduler-proc: exiting");
        }

        memmove(dst, rdata, len);
        rlen -= len;
        rdata += len;
}

static void
scheduler_proc_end(void)
{
        if (rlen) {
                log_warnx("warn: scheduler-proc: bogus data");
                fatalx("scheduler-proc: exiting");
        }
        imsg_free(&imsg);
}

/*
 * API
 */

static int
scheduler_proc_init(const char *conf)
{
        int             fd, r;
        uint32_t        version;

        fd = fork_proc_backend("scheduler", conf, "scheduler-proc", 0);
        if (fd == -1)
                fatalx("scheduler-proc: exiting");

        if (imsgbuf_init(&ibuf, fd) == -1)
                fatal("scheduler-proc: exiting");
        imsgbuf_allow_fdpass(&ibuf);

        version = PROC_SCHEDULER_API_VERSION;
        imsg_compose(&ibuf, PROC_SCHEDULER_INIT, 0, 0, -1,
            &version, sizeof(version));
        scheduler_proc_call();
        scheduler_proc_read(&r, sizeof(r));
        scheduler_proc_end();

        return (1);
}

static int
scheduler_proc_insert(struct scheduler_info *si)
{
        int     r;

        log_debug("debug: scheduler-proc: PROC_SCHEDULER_INSERT");

        imsg_compose(&ibuf, PROC_SCHEDULER_INSERT, 0, 0, -1, si, sizeof(*si));

        scheduler_proc_call();
        scheduler_proc_read(&r, sizeof(r));
        scheduler_proc_end();

        return (r);
}

static size_t
scheduler_proc_commit(uint32_t msgid)
{
        size_t  s;

        log_debug("debug: scheduler-proc: PROC_SCHEDULER_COMMIT");

        imsg_compose(&ibuf, PROC_SCHEDULER_COMMIT, 0, 0, -1,
            &msgid, sizeof(msgid));

        scheduler_proc_call();
        scheduler_proc_read(&s, sizeof(s));
        scheduler_proc_end();

        return (s);
}

static size_t
scheduler_proc_rollback(uint32_t msgid)
{
        size_t  s;

        log_debug("debug: scheduler-proc: PROC_SCHEDULER_ROLLBACK");

        imsg_compose(&ibuf, PROC_SCHEDULER_ROLLBACK, 0, 0, -1,
            &msgid, sizeof(msgid));

        scheduler_proc_call();
        scheduler_proc_read(&s, sizeof(s));
        scheduler_proc_end();

        return (s);
}

static int
scheduler_proc_update(struct scheduler_info *si)
{
        int     r;

        log_debug("debug: scheduler-proc: PROC_SCHEDULER_UPDATE");

        imsg_compose(&ibuf, PROC_SCHEDULER_UPDATE, 0, 0, -1, si, sizeof(*si));

        scheduler_proc_call();
        scheduler_proc_read(&r, sizeof(r));
        if (r == 1)
                scheduler_proc_read(si, sizeof(*si));
        scheduler_proc_end();

        return (r);
}

static int
scheduler_proc_delete(uint64_t evpid)
{
        int     r;

        log_debug("debug: scheduler-proc: PROC_SCHEDULER_DELETE");

        imsg_compose(&ibuf, PROC_SCHEDULER_DELETE, 0, 0, -1,
            &evpid, sizeof(evpid));

        scheduler_proc_call();
        scheduler_proc_read(&r, sizeof(r));
        scheduler_proc_end();

        return (r);
}

static int
scheduler_proc_hold(uint64_t evpid, uint64_t holdq)
{
        struct ibuf     *buf;
        int              r;

        log_debug("debug: scheduler-proc: PROC_SCHEDULER_HOLD");

        buf = imsg_create(&ibuf, PROC_SCHEDULER_HOLD, 0, 0,
            sizeof(evpid) + sizeof(holdq));
        if (buf == NULL)
                return (-1);
        if (imsg_add(buf, &evpid, sizeof(evpid)) == -1)
                return (-1);
        if (imsg_add(buf, &holdq, sizeof(holdq)) == -1)
                return (-1);
        imsg_close(&ibuf, buf);

        scheduler_proc_call();

        scheduler_proc_read(&r, sizeof(r));
        scheduler_proc_end();

        return (r);
}

static int
scheduler_proc_release(int type, uint64_t holdq, int n)
{
        struct ibuf     *buf;
        int              r;

        log_debug("debug: scheduler-proc: PROC_SCHEDULER_RELEASE");

        buf = imsg_create(&ibuf, PROC_SCHEDULER_RELEASE, 0, 0,
            sizeof(holdq) + sizeof(n));
        if (buf == NULL)
                return (-1);
        if (imsg_add(buf, &type, sizeof(type)) == -1)
                return (-1);
        if (imsg_add(buf, &holdq, sizeof(holdq)) == -1)
                return (-1);
        if (imsg_add(buf, &n, sizeof(n)) == -1)
                return (-1);
        imsg_close(&ibuf, buf);

        scheduler_proc_call();

        scheduler_proc_read(&r, sizeof(r));
        scheduler_proc_end();

        return (r);
}

static int
scheduler_proc_batch(int typemask, int *delay, size_t *count, uint64_t *evpids, int *types)
{
        struct ibuf     *buf;
        int              r;

        log_debug("debug: scheduler-proc: PROC_SCHEDULER_BATCH");

        buf = imsg_create(&ibuf, PROC_SCHEDULER_BATCH, 0, 0,
            sizeof(typemask) + sizeof(*count));
        if (buf == NULL)
                return (-1);
        if (imsg_add(buf, &typemask, sizeof(typemask)) == -1)
                return (-1);
        if (imsg_add(buf, count, sizeof(*count)) == -1)
                return (-1);
        imsg_close(&ibuf, buf);

        scheduler_proc_call();
        scheduler_proc_read(&r, sizeof(r));
        scheduler_proc_read(delay, sizeof(*delay));
        scheduler_proc_read(count, sizeof(*count));
        if (r > 0) {
                scheduler_proc_read(evpids, sizeof(*evpids) * (*count));
                scheduler_proc_read(types, sizeof(*types) * (*count));
        }
        scheduler_proc_end();

        return (r);
}

static size_t
scheduler_proc_messages(uint32_t from, uint32_t *dst, size_t size)
{
        struct ibuf     *buf;
        size_t           s;

        log_debug("debug: scheduler-proc: PROC_SCHEDULER_MESSAGES");

        buf = imsg_create(&ibuf, PROC_SCHEDULER_MESSAGES, 0, 0,
            sizeof(from) + sizeof(size));
        if (buf == NULL)
                return (-1);
        if (imsg_add(buf, &from, sizeof(from)) == -1)
                return (-1);
        if (imsg_add(buf, &size, sizeof(size)) == -1)
                return (-1);
        imsg_close(&ibuf, buf);

        scheduler_proc_call();

        s = rlen / sizeof(*dst);
        scheduler_proc_read(dst, s * sizeof(*dst));
        scheduler_proc_end();

        return (s);
}

static size_t
scheduler_proc_envelopes(uint64_t from, struct evpstate *dst, size_t size)
{
        struct ibuf     *buf;
        size_t           s;

        log_debug("debug: scheduler-proc: PROC_SCHEDULER_ENVELOPES");

        buf = imsg_create(&ibuf, PROC_SCHEDULER_ENVELOPES, 0, 0,
            sizeof(from) + sizeof(size));
        if (buf == NULL)
                return (-1);
        if (imsg_add(buf, &from, sizeof(from)) == -1)
                return (-1);
        if (imsg_add(buf, &size, sizeof(size)) == -1)
                return (-1);
        imsg_close(&ibuf, buf);

        scheduler_proc_call();

        s = rlen / sizeof(*dst);
        scheduler_proc_read(dst, s * sizeof(*dst));
        scheduler_proc_end();

        return (s);
}

static int
scheduler_proc_schedule(uint64_t evpid)
{
        int     r;

        log_debug("debug: scheduler-proc: PROC_SCHEDULER_SCHEDULE");

        imsg_compose(&ibuf, PROC_SCHEDULER_SCHEDULE, 0, 0, -1,
            &evpid, sizeof(evpid));

        scheduler_proc_call();

        scheduler_proc_read(&r, sizeof(r));
        scheduler_proc_end();

        return (r);
}

static int
scheduler_proc_remove(uint64_t evpid)
{
        int     r;

        log_debug("debug: scheduler-proc: PROC_SCHEDULER_REMOVE");

        imsg_compose(&ibuf, PROC_SCHEDULER_REMOVE, 0, 0, -1,
            &evpid, sizeof(evpid));

        scheduler_proc_call();

        scheduler_proc_read(&r, sizeof(r));
        scheduler_proc_end();

        return (r);
}

static int
scheduler_proc_suspend(uint64_t evpid)
{
        int     r;

        log_debug("debug: scheduler-proc: PROC_SCHEDULER_SUSPEND");

        imsg_compose(&ibuf, PROC_SCHEDULER_SUSPEND, 0, 0, -1,
            &evpid, sizeof(evpid));

        scheduler_proc_call();

        scheduler_proc_read(&r, sizeof(r));
        scheduler_proc_end();

        return (r);
}

static int
scheduler_proc_resume(uint64_t evpid)
{
        int     r;

        log_debug("debug: scheduler-proc: PROC_SCHEDULER_RESUME");

        imsg_compose(&ibuf, PROC_SCHEDULER_RESUME, 0, 0, -1,
            &evpid, sizeof(evpid));

        scheduler_proc_call();

        scheduler_proc_read(&r, sizeof(r));
        scheduler_proc_end();

        return (r);
}

struct scheduler_backend scheduler_backend_proc = {
        scheduler_proc_init,
        scheduler_proc_insert,
        scheduler_proc_commit,
        scheduler_proc_rollback,
        scheduler_proc_update,
        scheduler_proc_delete,
        scheduler_proc_hold,
        scheduler_proc_release,
        scheduler_proc_batch,
        scheduler_proc_messages,
        scheduler_proc_envelopes,
        scheduler_proc_schedule,
        scheduler_proc_remove,
        scheduler_proc_suspend,
        scheduler_proc_resume,
};