/*-
 * Copyright 2016 Vsevolod Stakhov
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#include "config.h"
#include "rspamd.h"
#include "rspamd_control.h"
#include "worker_util.h"
#include "libserver/http/http_connection.h"
#include "libserver/http/http_private.h"
#include "libutil/libev_helper.h"
#include "unix-std.h"
#include "utlist.h"

#ifdef HAVE_SYS_RESOURCE_H
#include <sys/resource.h>
#endif

#ifdef WITH_HYPERSCAN
#include "hyperscan_tools.h"
#endif

static ev_tstamp io_timeout = 30.0;
static ev_tstamp worker_io_timeout = 0.5;

struct rspamd_control_session;

struct rspamd_control_reply_elt {
	struct rspamd_control_reply reply;
	struct rspamd_io_ev ev;
	struct ev_loop *event_loop;
	GQuark wrk_type;
	pid_t wrk_pid;
	gpointer ud;
	gint attached_fd;
	GHashTable *pending_elts;
	struct rspamd_control_reply_elt *prev, *next;
};

struct rspamd_control_session {
	gint fd;
	struct ev_loop *event_loop;
	struct rspamd_main *rspamd_main;
	struct rspamd_http_connection *conn;
	struct rspamd_control_command cmd;
	struct rspamd_control_reply_elt *replies;
	rspamd_inet_addr_t *addr;
	guint replies_remain;
	gboolean is_reply;
};

static const struct rspamd_control_cmd_match {
	rspamd_ftok_t name;
	enum rspamd_control_type type;
} cmd_matches[] = {
	{.name = {
		 .begin = "/stat",
		 .len = sizeof("/stat") - 1},
	 .type = RSPAMD_CONTROL_STAT},
	{.name = {.begin = "/reload", .len = sizeof("/reload") - 1}, .type = RSPAMD_CONTROL_RELOAD},
	{.name = {.begin = "/reresolve", .len = sizeof("/reresolve") - 1}, .type = RSPAMD_CONTROL_RERESOLVE},
	{.name = {.begin = "/recompile", .len = sizeof("/recompile") - 1}, .type = RSPAMD_CONTROL_RECOMPILE},
	{.name = {.begin = "/fuzzystat", .len = sizeof("/fuzzystat") - 1}, .type = RSPAMD_CONTROL_FUZZY_STAT},
	{.name = {.begin = "/fuzzysync", .len = sizeof("/fuzzysync") - 1}, .type = RSPAMD_CONTROL_FUZZY_SYNC},
};

static void rspamd_control_ignore_io_handler(int fd, short what, void *ud);

static void
rspamd_control_stop_pending(struct rspamd_control_reply_elt *elt)
{
	GHashTable *htb;
	/* It stops event and frees hash */
	htb = elt->pending_elts;
	g_hash_table_remove(elt->pending_elts, elt);
	/* Release hash reference */
	g_hash_table_unref(htb);
}

void rspamd_control_send_error(struct rspamd_control_session *session,
							   gint code, const gchar *error_msg, ...)
{
	struct rspamd_http_message *msg;
	rspamd_fstring_t *reply;
	va_list args;

	msg = rspamd_http_new_message(HTTP_RESPONSE);

	va_start(args, error_msg);
	msg->status = rspamd_fstring_new();
	rspamd_vprintf_fstring(&msg->status, error_msg, args);
	va_end(args);

	msg->date = time(NULL);
	msg->code = code;
	reply = rspamd_fstring_sized_new(msg->status->len + 16);
	rspamd_printf_fstring(&reply, "{\"error\":\"%V\"}", msg->status);
	rspamd_http_message_set_body_from_fstring_steal(msg, reply);
	rspamd_http_connection_reset(session->conn);
	rspamd_http_connection_write_message(session->conn,
										 msg,
										 NULL,
										 "application/json",
										 session,
										 io_timeout);
}

static void
rspamd_control_send_ucl(struct rspamd_control_session *session,
						ucl_object_t *obj)
{
	struct rspamd_http_message *msg;
	rspamd_fstring_t *reply;

	msg = rspamd_http_new_message(HTTP_RESPONSE);
	msg->date = time(NULL);
	msg->code = 200;
	msg->status = rspamd_fstring_new_init("OK", 2);
	reply = rspamd_fstring_sized_new(BUFSIZ);
	rspamd_ucl_emit_fstring(obj, UCL_EMIT_JSON_COMPACT, &reply);
	rspamd_http_message_set_body_from_fstring_steal(msg, reply);
	rspamd_http_connection_reset(session->conn);
	rspamd_http_connection_write_message(session->conn,
										 msg,
										 NULL,
										 "application/json",
										 session,
										 io_timeout);
}

static void
rspamd_control_connection_close(struct rspamd_control_session *session)
{
	struct rspamd_control_reply_elt *elt, *telt;
	struct rspamd_main *rspamd_main;

	rspamd_main = session->rspamd_main;
	msg_info_main("finished connection from %s",
				  rspamd_inet_address_to_string(session->addr));

	DL_FOREACH_SAFE(session->replies, elt, telt)
	{
		rspamd_control_stop_pending(elt);
	}

	rspamd_inet_address_free(session->addr);
	rspamd_http_connection_unref(session->conn);
	close(session->fd);
	g_free(session);
}

static void
rspamd_control_write_reply(struct rspamd_control_session *session)
{
	ucl_object_t *rep, *cur, *workers;
	struct rspamd_control_reply_elt *elt;
	gchar tmpbuf[64];
	gdouble total_utime = 0, total_systime = 0;
	struct ucl_parser *parser;
	guint total_conns = 0;

	rep = ucl_object_typed_new(UCL_OBJECT);
	workers = ucl_object_typed_new(UCL_OBJECT);

	DL_FOREACH(session->replies, elt)
	{
		/* Skip incompatible worker for fuzzy_stat */
		if ((session->cmd.type == RSPAMD_CONTROL_FUZZY_STAT ||
			 session->cmd.type == RSPAMD_CONTROL_FUZZY_SYNC) &&
			elt->wrk_type != g_quark_from_static_string("fuzzy")) {
			continue;
		}

		rspamd_snprintf(tmpbuf, sizeof(tmpbuf), "%P", elt->wrk_pid);
		cur = ucl_object_typed_new(UCL_OBJECT);

		ucl_object_insert_key(cur, ucl_object_fromstring(g_quark_to_string(elt->wrk_type)), "type", 0, false);

		switch (session->cmd.type) {
		case RSPAMD_CONTROL_STAT:
			ucl_object_insert_key(cur, ucl_object_fromint(elt->reply.reply.stat.conns), "conns", 0, false);
			ucl_object_insert_key(cur, ucl_object_fromdouble(elt->reply.reply.stat.utime), "utime", 0, false);
			ucl_object_insert_key(cur, ucl_object_fromdouble(elt->reply.reply.stat.systime), "systime", 0, false);
			ucl_object_insert_key(cur, ucl_object_fromdouble(elt->reply.reply.stat.uptime), "uptime", 0, false);
			ucl_object_insert_key(cur, ucl_object_fromint(elt->reply.reply.stat.maxrss), "maxrss", 0, false);

			total_utime += elt->reply.reply.stat.utime;
			total_systime += elt->reply.reply.stat.systime;
			total_conns += elt->reply.reply.stat.conns;

			break;

		case RSPAMD_CONTROL_RELOAD:
			ucl_object_insert_key(cur, ucl_object_fromint(elt->reply.reply.reload.status), "status", 0, false);
			break;
		case RSPAMD_CONTROL_RECOMPILE:
			ucl_object_insert_key(cur, ucl_object_fromint(elt->reply.reply.recompile.status), "status", 0, false);
			break;
		case RSPAMD_CONTROL_RERESOLVE:
			ucl_object_insert_key(cur, ucl_object_fromint(elt->reply.reply.reresolve.status), "status", 0, false);
			break;
		case RSPAMD_CONTROL_FUZZY_STAT:
			if (elt->attached_fd != -1) {
				/* We have some data to parse */
				parser = ucl_parser_new(0);
				ucl_object_insert_key(cur,
									  ucl_object_fromint(
										  elt->reply.reply.fuzzy_stat.status),
									  "status",
									  0,
									  false);

				if (ucl_parser_add_fd(parser, elt->attached_fd)) {
					ucl_object_insert_key(cur, ucl_parser_get_object(parser),
										  "data", 0, false);
					ucl_parser_free(parser);
				}
				else {

					ucl_object_insert_key(cur, ucl_object_fromstring(ucl_parser_get_error(parser)), "error", 0, false);

					ucl_parser_free(parser);
				}

				ucl_object_insert_key(cur,
									  ucl_object_fromlstring(
										  elt->reply.reply.fuzzy_stat.storage_id,
										  MEMPOOL_UID_LEN - 1),
									  "id",
									  0,
									  false);
			}
			else {
				ucl_object_insert_key(cur,
									  ucl_object_fromstring("missing file"),
									  "error",
									  0,
									  false);
				ucl_object_insert_key(cur,
									  ucl_object_fromint(
										  elt->reply.reply.fuzzy_stat.status),
									  "status",
									  0,
									  false);
			}
			break;
		case RSPAMD_CONTROL_FUZZY_SYNC:
			ucl_object_insert_key(cur, ucl_object_fromint(elt->reply.reply.fuzzy_sync.status), "status", 0, false);
			break;
		default:
			break;
		}

		if (elt->attached_fd != -1) {
			close(elt->attached_fd);
			elt->attached_fd = -1;
		}

		ucl_object_insert_key(workers, cur, tmpbuf, 0, true);
	}

	ucl_object_insert_key(rep, workers, "workers", 0, false);

	if (session->cmd.type == RSPAMD_CONTROL_STAT) {
		/* Total stats */
		cur = ucl_object_typed_new(UCL_OBJECT);
		ucl_object_insert_key(cur, ucl_object_fromint(total_conns), "conns", 0, false);
		ucl_object_insert_key(cur, ucl_object_fromdouble(total_utime), "utime", 0, false);
		ucl_object_insert_key(cur, ucl_object_fromdouble(total_systime), "systime", 0, false);

		ucl_object_insert_key(rep, cur, "total", 0, false);
	}

	rspamd_control_send_ucl(session, rep);
	ucl_object_unref(rep);
}

static void
rspamd_control_wrk_io(gint fd, short what, gpointer ud)
{
	struct rspamd_control_reply_elt *elt = ud;
	struct rspamd_control_session *session;
	guchar fdspace[CMSG_SPACE(sizeof(int))];
	struct iovec iov;
	struct msghdr msg;
	gssize r;

	session = elt->ud;
	elt->attached_fd = -1;

	if (what == EV_READ) {
		iov.iov_base = &elt->reply;
		iov.iov_len = sizeof(elt->reply);
		memset(&msg, 0, sizeof(msg));
		msg.msg_control = fdspace;
		msg.msg_controllen = sizeof(fdspace);
		msg.msg_iov = &iov;
		msg.msg_iovlen = 1;

		r = recvmsg(fd, &msg, 0);
		if (r == -1) {
			msg_err("cannot read reply from the worker %P (%s): %s",
					elt->wrk_pid, g_quark_to_string(elt->wrk_type),
					strerror(errno));
		}
		else if (r >= (gssize) sizeof(elt->reply)) {
			if (msg.msg_controllen >= CMSG_LEN(sizeof(int))) {
				elt->attached_fd = *(int *) CMSG_DATA(CMSG_FIRSTHDR(&msg));
			}
		}
	}
	else {
		/* Timeout waiting */
		msg_warn("timeout waiting reply from %P (%s)",
				 elt->wrk_pid, g_quark_to_string(elt->wrk_type));
	}

	session->replies_remain--;
	rspamd_ev_watcher_stop(session->event_loop,
						   &elt->ev);

	if (session->replies_remain == 0) {
		rspamd_control_write_reply(session);
	}
}

static void
rspamd_control_error_handler(struct rspamd_http_connection *conn, GError *err)
{
	struct rspamd_control_session *session = conn->ud;
	struct rspamd_main *rspamd_main;

	rspamd_main = session->rspamd_main;

	if (!session->is_reply) {
		msg_info_main("abnormally closing control connection: %e", err);
		session->is_reply = TRUE;
		rspamd_control_send_error(session, err->code, "%s", err->message);
	}
	else {
		rspamd_control_connection_close(session);
	}
}

void rspamd_pending_control_free(gpointer p)
{
	struct rspamd_control_reply_elt *rep_elt = (struct rspamd_control_reply_elt *) p;

	rspamd_ev_watcher_stop(rep_elt->event_loop, &rep_elt->ev);
	g_free(rep_elt);
}

static struct rspamd_control_reply_elt *
rspamd_control_broadcast_cmd(struct rspamd_main *rspamd_main,
							 struct rspamd_control_command *cmd,
							 gint attached_fd,
							 rspamd_ev_cb handler,
							 gpointer ud,
							 pid_t except_pid)
{
	GHashTableIter it;
	struct rspamd_worker *wrk;
	struct rspamd_control_reply_elt *rep_elt, *res = NULL;
	gpointer k, v;
	struct msghdr msg;
	struct cmsghdr *cmsg;
	struct iovec iov;
	guchar fdspace[CMSG_SPACE(sizeof(int))];
	gssize r;

	g_hash_table_iter_init(&it, rspamd_main->workers);

	while (g_hash_table_iter_next(&it, &k, &v)) {
		wrk = v;

		/* No control pipe */
		if (wrk->control_pipe[0] == -1) {
			continue;
		}

		if (except_pid != 0 && wrk->pid == except_pid) {
			continue;
		}

		/* Worker is terminating, do not bother sending stuff */
		if (wrk->state == rspamd_worker_state_terminating) {
			continue;
		}

		memset(&msg, 0, sizeof(msg));

		/* Attach fd to the message */
		if (attached_fd != -1) {
			memset(fdspace, 0, sizeof(fdspace));
			msg.msg_control = fdspace;
			msg.msg_controllen = sizeof(fdspace);
			cmsg = CMSG_FIRSTHDR(&msg);
			cmsg->cmsg_level = SOL_SOCKET;
			cmsg->cmsg_type = SCM_RIGHTS;
			cmsg->cmsg_len = CMSG_LEN(sizeof(int));
			memcpy(CMSG_DATA(cmsg), &attached_fd, sizeof(int));
		}

		iov.iov_base = cmd;
		iov.iov_len = sizeof(*cmd);
		msg.msg_iov = &iov;
		msg.msg_iovlen = 1;

		r = sendmsg(wrk->control_pipe[0], &msg, 0);

		if (r == sizeof(*cmd)) {
			rep_elt = g_malloc0(sizeof(*rep_elt));
			rep_elt->wrk_pid = wrk->pid;
			rep_elt->wrk_type = wrk->type;
			rep_elt->event_loop = rspamd_main->event_loop;
			rep_elt->ud = ud;
			rep_elt->pending_elts = g_hash_table_ref(wrk->control_events_pending);
			rspamd_ev_watcher_init(&rep_elt->ev,
								   wrk->control_pipe[0],
								   EV_READ, handler,
								   rep_elt);
			rspamd_ev_watcher_start(rspamd_main->event_loop,
									&rep_elt->ev, worker_io_timeout);
			g_hash_table_insert(wrk->control_events_pending, rep_elt, rep_elt);

			DL_APPEND(res, rep_elt);
		}
		else {
			msg_err_main("cannot write command %d(%z) to the worker %P(%s), fd: %d: %s",
						 (int) cmd->type, iov.iov_len,
						 wrk->pid,
						 g_quark_to_string(wrk->type),
						 wrk->control_pipe[0],
						 strerror(errno));
		}
	}

	return res;
}

void rspamd_control_broadcast_srv_cmd(struct rspamd_main *rspamd_main,
									  struct rspamd_control_command *cmd,
									  pid_t except_pid)
{
	rspamd_control_broadcast_cmd(rspamd_main, cmd, -1,
								 rspamd_control_ignore_io_handler, NULL, except_pid);
}

static gint
rspamd_control_finish_handler(struct rspamd_http_connection *conn,
							  struct rspamd_http_message *msg)
{
	struct rspamd_control_session *session = conn->ud;
	rspamd_ftok_t srch;
	guint i;
	gboolean found = FALSE;
	struct rspamd_control_reply_elt *cur;


	if (!session->is_reply) {
		if (msg->url == NULL) {
			rspamd_control_connection_close(session);

			return 0;
		}

		srch.begin = msg->url->str;
		srch.len = msg->url->len;

		session->is_reply = TRUE;

		for (i = 0; i < G_N_ELEMENTS(cmd_matches); i++) {
			if (rspamd_ftok_casecmp(&srch, &cmd_matches[i].name) == 0) {
				session->cmd.type = cmd_matches[i].type;
				found = TRUE;
				break;
			}
		}

		if (!found) {
			rspamd_control_send_error(session, 404, "Command not defined");
		}
		else {
			/* Send command to all workers */
			session->replies = rspamd_control_broadcast_cmd(
				session->rspamd_main, &session->cmd, -1,
				rspamd_control_wrk_io, session, 0);

			DL_FOREACH(session->replies, cur)
			{
				session->replies_remain++;
			}
		}
	}
	else {
		rspamd_control_connection_close(session);
	}


	return 0;
}

void rspamd_control_process_client_socket(struct rspamd_main *rspamd_main,
										  gint fd, rspamd_inet_addr_t *addr)
{
	struct rspamd_control_session *session;

	session = g_malloc0(sizeof(*session));

	session->fd = fd;
	session->conn = rspamd_http_connection_new_server(rspamd_main->http_ctx,
													  fd,
													  NULL,
													  rspamd_control_error_handler,
													  rspamd_control_finish_handler,
													  0);
	session->rspamd_main = rspamd_main;
	session->addr = addr;
	session->event_loop = rspamd_main->event_loop;
	rspamd_http_connection_read_message(session->conn, session,
										io_timeout);
}

struct rspamd_worker_control_data {
	ev_io io_ev;
	struct rspamd_worker *worker;
	struct ev_loop *ev_base;
	struct {
		rspamd_worker_control_handler handler;
		gpointer ud;
	} handlers[RSPAMD_CONTROL_MAX];
};

static void
rspamd_control_default_cmd_handler(gint fd,
								   gint attached_fd,
								   struct rspamd_worker_control_data *cd,
								   struct rspamd_control_command *cmd)
{
	struct rspamd_control_reply rep;
	gssize r;
	struct rusage rusg;
	struct rspamd_config *cfg;
	struct rspamd_main *rspamd_main;

	memset(&rep, 0, sizeof(rep));
	rep.type = cmd->type;
	rspamd_main = cd->worker->srv;

	switch (cmd->type) {
	case RSPAMD_CONTROL_STAT:
		if (getrusage(RUSAGE_SELF, &rusg) == -1) {
			msg_err_main("cannot get rusage stats: %s",
						 strerror(errno));
		}
		else {
			rep.reply.stat.utime = tv_to_double(&rusg.ru_utime);
			rep.reply.stat.systime = tv_to_double(&rusg.ru_stime);
			rep.reply.stat.maxrss = rusg.ru_maxrss;
		}

		rep.reply.stat.conns = cd->worker->nconns;
		rep.reply.stat.uptime = rspamd_get_calendar_ticks() - cd->worker->start_time;
		break;
	case RSPAMD_CONTROL_RELOAD:
	case RSPAMD_CONTROL_RECOMPILE:
	case RSPAMD_CONTROL_HYPERSCAN_LOADED:
	case RSPAMD_CONTROL_MONITORED_CHANGE:
	case RSPAMD_CONTROL_FUZZY_STAT:
	case RSPAMD_CONTROL_FUZZY_SYNC:
	case RSPAMD_CONTROL_LOG_PIPE:
	case RSPAMD_CONTROL_CHILD_CHANGE:
	case RSPAMD_CONTROL_FUZZY_BLOCKED:
		break;
	case RSPAMD_CONTROL_RERESOLVE:
		if (cd->worker->srv->cfg) {
			REF_RETAIN(cd->worker->srv->cfg);
			cfg = cd->worker->srv->cfg;

			if (cfg->ups_ctx) {
				msg_info_config("reresolving upstreams");
				rspamd_upstream_reresolve(cfg->ups_ctx);
			}

			rep.reply.reresolve.status = 0;
			REF_RELEASE(cfg);
		}
		else {
			rep.reply.reresolve.status = EINVAL;
		}
		break;
	default:
		break;
	}

	r = write(fd, &rep, sizeof(rep));

	if (r != sizeof(rep)) {
		msg_err_main("cannot write reply to the control socket: %s",
					 strerror(errno));
	}

	if (attached_fd != -1) {
		close(attached_fd);
	}
}

static void
rspamd_control_default_worker_handler(EV_P_ ev_io *w, int revents)
{
	struct rspamd_worker_control_data *cd =
		(struct rspamd_worker_control_data *) w->data;
	static struct rspamd_control_command cmd;
	static struct msghdr msg;
	static struct iovec iov;
	static guchar fdspace[CMSG_SPACE(sizeof(int))];
	gint rfd = -1;
	gssize r;

	iov.iov_base = &cmd;
	iov.iov_len = sizeof(cmd);
	memset(&msg, 0, sizeof(msg));
	msg.msg_control = fdspace;
	msg.msg_controllen = sizeof(fdspace);
	msg.msg_iov = &iov;
	msg.msg_iovlen = 1;

	r = recvmsg(w->fd, &msg, 0);

	if (r == -1) {
		if (errno != EAGAIN && errno != EINTR) {
			if (errno != ECONNRESET) {
				/*
				 * In case of connection reset it means that main process
				 * has died, so do not pollute logs
				 */
				msg_err("cannot read request from the control socket: %s",
						strerror(errno));
			}
			ev_io_stop(cd->ev_base, &cd->io_ev);
			close(w->fd);
		}
	}
	else if (r < (gint) sizeof(cmd)) {
		msg_err("short read of control command: %d of %d", (gint) r,
				(gint) sizeof(cmd));

		if (r == 0) {
			ev_io_stop(cd->ev_base, &cd->io_ev);
			close(w->fd);
		}
	}
	else if ((gint) cmd.type >= 0 && cmd.type < RSPAMD_CONTROL_MAX) {

		if (msg.msg_controllen >= CMSG_LEN(sizeof(int))) {
			rfd = *(int *) CMSG_DATA(CMSG_FIRSTHDR(&msg));
		}

		if (cd->handlers[cmd.type].handler) {
			cd->handlers[cmd.type].handler(cd->worker->srv,
										   cd->worker,
										   w->fd,
										   rfd,
										   &cmd,
										   cd->handlers[cmd.type].ud);
		}
		else {
			rspamd_control_default_cmd_handler(w->fd, rfd, cd, &cmd);
		}
	}
	else {
		msg_err("unknown command: %d", (gint) cmd.type);
	}
}

void rspamd_control_worker_add_default_cmd_handlers(struct rspamd_worker *worker,
													struct ev_loop *ev_base)
{
	struct rspamd_worker_control_data *cd;

	cd = g_malloc0(sizeof(*cd));
	cd->worker = worker;
	cd->ev_base = ev_base;

	cd->io_ev.data = cd;
	ev_io_init(&cd->io_ev, rspamd_control_default_worker_handler,
			   worker->control_pipe[1], EV_READ);
	ev_io_start(ev_base, &cd->io_ev);

	worker->control_data = cd;
}

/**
 * Register custom handler for a specific control command for this worker
 */
void rspamd_control_worker_add_cmd_handler(struct rspamd_worker *worker,
										   enum rspamd_control_type type,
										   rspamd_worker_control_handler handler,
										   gpointer ud)
{
	struct rspamd_worker_control_data *cd;

	g_assert(type >= 0 && type < RSPAMD_CONTROL_MAX);
	g_assert(handler != NULL);
	g_assert(worker->control_data != NULL);

	cd = worker->control_data;
	cd->handlers[type].handler = handler;
	cd->handlers[type].ud = ud;
}

struct rspamd_srv_reply_data {
	struct rspamd_worker *worker;
	struct rspamd_main *srv;
	gint fd;
	struct rspamd_srv_reply rep;
};

static void
rspamd_control_ignore_io_handler(int fd, short what, void *ud)
{
	struct rspamd_control_reply_elt *elt =
		(struct rspamd_control_reply_elt *) ud;

	struct rspamd_control_reply rep;

	/* At this point we just ignore replies from the workers */
	if (read(fd, &rep, sizeof(rep)) == -1) {
		msg_debug("cannot read %d bytes: %s", (int) sizeof(rep), strerror(errno));
	}
	rspamd_control_stop_pending(elt);
}

static void
rspamd_control_log_pipe_io_handler(int fd, short what, void *ud)
{
	struct rspamd_control_reply_elt *elt =
		(struct rspamd_control_reply_elt *) ud;
	struct rspamd_control_reply rep;

	/* At this point we just ignore replies from the workers */
	(void) !read(fd, &rep, sizeof(rep));
	rspamd_control_stop_pending(elt);
}

static void
rspamd_control_handle_on_fork(struct rspamd_srv_command *cmd,
							  struct rspamd_main *srv)
{
	struct rspamd_worker *parent, *child;

	parent = g_hash_table_lookup(srv->workers,
								 GSIZE_TO_POINTER(cmd->cmd.on_fork.ppid));

	if (parent == NULL) {
		msg_err("cannot find parent for a forked process %P (%P child)",
				cmd->cmd.on_fork.ppid, cmd->cmd.on_fork.cpid);

		return;
	}

	if (cmd->cmd.on_fork.state == child_dead) {
		/* We need to remove stale worker */
		child = g_hash_table_lookup(srv->workers,
									GSIZE_TO_POINTER(cmd->cmd.on_fork.cpid));

		if (child == NULL) {
			msg_err("cannot find child for a forked process %P (%P parent)",
					cmd->cmd.on_fork.cpid, cmd->cmd.on_fork.ppid);

			return;
		}

		REF_RELEASE(child->cf);
		g_hash_table_remove(srv->workers,
							GSIZE_TO_POINTER(cmd->cmd.on_fork.cpid));
		g_hash_table_unref(child->control_events_pending);
		g_free(child);
	}
	else {
		child = g_malloc0(sizeof(struct rspamd_worker));
		child->srv = srv;
		child->type = parent->type;
		child->pid = cmd->cmd.on_fork.cpid;
		child->srv_pipe[0] = -1;
		child->srv_pipe[1] = -1;
		child->control_pipe[0] = -1;
		child->control_pipe[1] = -1;
		child->cf = parent->cf;
		child->ppid = parent->pid;
		REF_RETAIN(child->cf);
		child->control_events_pending = g_hash_table_new_full(g_direct_hash, g_direct_equal,
															  NULL, rspamd_pending_control_free);
		g_hash_table_insert(srv->workers,
							GSIZE_TO_POINTER(cmd->cmd.on_fork.cpid), child);
	}
}

static void
rspamd_fill_health_reply(struct rspamd_main *srv, struct rspamd_srv_reply *rep)
{
	GHashTableIter it;
	gpointer k, v;

	memset(&rep->reply.health, 0, sizeof(rep->reply));
	g_hash_table_iter_init(&it, srv->workers);

	while (g_hash_table_iter_next(&it, &k, &v)) {
		struct rspamd_worker *wrk = (struct rspamd_worker *) v;

		if (wrk->hb.nbeats < 0) {
			rep->reply.health.workers_hb_lost++;
		}
		else if (rspamd_worker_is_scanner(wrk)) {
			rep->reply.health.scanners_count++;
		}

		rep->reply.health.workers_count++;
	}

	rep->reply.status = (g_hash_table_size(srv->workers) > 0);
}


static void
rspamd_srv_handler(EV_P_ ev_io *w, int revents)
{
	struct rspamd_worker *worker;
	static struct rspamd_srv_command cmd;
	struct rspamd_main *srv;
	struct rspamd_srv_reply_data *rdata;
	struct msghdr msg;
	struct cmsghdr *cmsg;
	static struct iovec iov;
	static guchar fdspace[CMSG_SPACE(sizeof(int))];
	gint *spair, rfd = -1;
	gchar *nid;
	struct rspamd_control_command wcmd;
	gssize r;

	if (revents == EV_READ) {
		worker = (struct rspamd_worker *) w->data;
		srv = worker->srv;
		iov.iov_base = &cmd;
		iov.iov_len = sizeof(cmd);
		memset(&msg, 0, sizeof(msg));
		msg.msg_control = fdspace;
		msg.msg_controllen = sizeof(fdspace);
		msg.msg_iov = &iov;
		msg.msg_iovlen = 1;

		r = recvmsg(w->fd, &msg, 0);

		if (r == -1) {
			if (errno != EAGAIN) {
				msg_err("cannot read from worker's srv pipe: %s",
						strerror(errno));
			}
			else {
				return;
			}
		}
		else if (r == 0) {
			/*
			 * Usually this means that a worker is dead, so do not try to read
			 * anything
			 */
			msg_err("cannot read from worker's srv pipe connection closed; command = %s",
					rspamd_srv_command_to_string(cmd.type));
			ev_io_stop(EV_A_ w);
		}
		else if (r != sizeof(cmd)) {
			msg_err("cannot read from worker's srv pipe incomplete command: %d != %d; command = %s",
					(gint) r, (gint) sizeof(cmd), rspamd_srv_command_to_string(cmd.type));
		}
		else {
			rdata = g_malloc0(sizeof(*rdata));
			rdata->worker = worker;
			rdata->srv = srv;
			rdata->rep.id = cmd.id;
			rdata->rep.type = cmd.type;
			rdata->fd = -1;
			worker->tmp_data = rdata;

			if (msg.msg_controllen >= CMSG_LEN(sizeof(int))) {
				rfd = *(int *) CMSG_DATA(CMSG_FIRSTHDR(&msg));
			}

			switch (cmd.type) {
			case RSPAMD_SRV_SOCKETPAIR:
				spair = g_hash_table_lookup(srv->spairs, cmd.cmd.spair.pair_id);
				if (spair == NULL) {
					spair = g_malloc(sizeof(gint) * 2);

					if (rspamd_socketpair(spair, cmd.cmd.spair.af) == -1) {
						rdata->rep.reply.spair.code = errno;
						msg_err("cannot create socket pair: %s", strerror(errno));
					}
					else {
						nid = g_malloc(sizeof(cmd.cmd.spair.pair_id));
						memcpy(nid, cmd.cmd.spair.pair_id,
							   sizeof(cmd.cmd.spair.pair_id));
						g_hash_table_insert(srv->spairs, nid, spair);
						rdata->rep.reply.spair.code = 0;
						rdata->fd = cmd.cmd.spair.pair_num ? spair[1] : spair[0];
					}
				}
				else {
					rdata->rep.reply.spair.code = 0;
					rdata->fd = cmd.cmd.spair.pair_num ? spair[1] : spair[0];
				}
				break;
			case RSPAMD_SRV_HYPERSCAN_LOADED:
				/* Load RE cache to provide it for new forks */
				if (rspamd_re_cache_is_hs_loaded(srv->cfg->re_cache) != RSPAMD_HYPERSCAN_LOADED_FULL ||
					cmd.cmd.hs_loaded.forced) {
					rspamd_re_cache_load_hyperscan(
						srv->cfg->re_cache,
						cmd.cmd.hs_loaded.cache_dir,
						false);
				}

				/* Broadcast command to all workers */
				memset(&wcmd, 0, sizeof(wcmd));
				wcmd.type = RSPAMD_CONTROL_HYPERSCAN_LOADED;
				rspamd_strlcpy(wcmd.cmd.hs_loaded.cache_dir,
							   cmd.cmd.hs_loaded.cache_dir,
							   sizeof(wcmd.cmd.hs_loaded.cache_dir));
				wcmd.cmd.hs_loaded.forced = cmd.cmd.hs_loaded.forced;
				rspamd_control_broadcast_cmd(srv, &wcmd, rfd,
											 rspamd_control_ignore_io_handler, NULL, worker->pid);
				break;
			case RSPAMD_SRV_MONITORED_CHANGE:
				/* Broadcast command to all workers */
				memset(&wcmd, 0, sizeof(wcmd));
				wcmd.type = RSPAMD_CONTROL_MONITORED_CHANGE;
				rspamd_strlcpy(wcmd.cmd.monitored_change.tag,
							   cmd.cmd.monitored_change.tag,
							   sizeof(wcmd.cmd.monitored_change.tag));
				wcmd.cmd.monitored_change.alive = cmd.cmd.monitored_change.alive;
				wcmd.cmd.monitored_change.sender = cmd.cmd.monitored_change.sender;
				rspamd_control_broadcast_cmd(srv, &wcmd, rfd,
											 rspamd_control_ignore_io_handler, NULL, 0);
				break;
			case RSPAMD_SRV_LOG_PIPE:
				memset(&wcmd, 0, sizeof(wcmd));
				wcmd.type = RSPAMD_CONTROL_LOG_PIPE;
				wcmd.cmd.log_pipe.type = cmd.cmd.log_pipe.type;
				rspamd_control_broadcast_cmd(srv, &wcmd, rfd,
											 rspamd_control_log_pipe_io_handler, NULL, 0);
				break;
			case RSPAMD_SRV_ON_FORK:
				rdata->rep.reply.on_fork.status = 0;
				rspamd_control_handle_on_fork(&cmd, srv);
				break;
			case RSPAMD_SRV_HEARTBEAT:
				worker->hb.last_event = ev_time();
				rdata->rep.reply.heartbeat.status = 0;
				break;
			case RSPAMD_SRV_HEALTH:
				rspamd_fill_health_reply(srv, &rdata->rep);
				break;
			case RSPAMD_SRV_NOTICE_HYPERSCAN_CACHE:
#ifdef WITH_HYPERSCAN
				rspamd_hyperscan_notice_known(cmd.cmd.hyperscan_cache_file.path);
#endif
				rdata->rep.reply.hyperscan_cache_file.unused = 0;
				break;
			case RSPAMD_SRV_FUZZY_BLOCKED:
				/* Broadcast command to all workers */
				memset(&wcmd, 0, sizeof(wcmd));
				wcmd.type = RSPAMD_CONTROL_FUZZY_BLOCKED;
				/* Ensure that memcpy is safe */
				G_STATIC_ASSERT(sizeof(wcmd.cmd.fuzzy_blocked) == sizeof(cmd.cmd.fuzzy_blocked));
				memcpy(&wcmd.cmd.fuzzy_blocked, &cmd.cmd.fuzzy_blocked, sizeof(wcmd.cmd.fuzzy_blocked));
				rspamd_control_broadcast_cmd(srv, &wcmd, rfd,
											 rspamd_control_ignore_io_handler, NULL, worker->pid);
				break;
			default:
				msg_err("unknown command type: %d", cmd.type);
				break;
			}

			if (rfd != -1) {
				/* Close our copy to avoid descriptors leak */
				close(rfd);
			}

			/* Now plan write event and send data back */
			w->data = rdata;
			ev_io_stop(EV_A_ w);
			ev_io_set(w, worker->srv_pipe[0], EV_WRITE);
			ev_io_start(EV_A_ w);
		}
	}
	else if (revents == EV_WRITE) {
		rdata = (struct rspamd_srv_reply_data *) w->data;
		worker = rdata->worker;
		worker->tmp_data = NULL; /* Avoid race */
		srv = rdata->srv;

		memset(&msg, 0, sizeof(msg));

		/* Attach fd to the message */
		if (rdata->fd != -1) {
			memset(fdspace, 0, sizeof(fdspace));
			msg.msg_control = fdspace;
			msg.msg_controllen = sizeof(fdspace);
			cmsg = CMSG_FIRSTHDR(&msg);
			cmsg->cmsg_level = SOL_SOCKET;
			cmsg->cmsg_type = SCM_RIGHTS;
			cmsg->cmsg_len = CMSG_LEN(sizeof(int));
			memcpy(CMSG_DATA(cmsg), &rdata->fd, sizeof(int));
		}

		iov.iov_base = &rdata->rep;
		iov.iov_len = sizeof(rdata->rep);
		msg.msg_iov = &iov;
		msg.msg_iovlen = 1;

		r = sendmsg(w->fd, &msg, 0);

		if (r == -1) {
			msg_err("cannot write to worker's srv pipe when writing reply: %s; command = %s",
					strerror(errno), rspamd_srv_command_to_string(rdata->rep.type));
		}
		else if (r != sizeof(rdata->rep)) {
			msg_err("cannot write to worker's srv pipe: %d != %d; command = %s",
					(int) r, (int) sizeof(rdata->rep),
					rspamd_srv_command_to_string(rdata->rep.type));
		}

		g_free(rdata);
		w->data = worker;
		ev_io_stop(EV_A_ w);
		ev_io_set(w, worker->srv_pipe[0], EV_READ);
		ev_io_start(EV_A_ w);
	}
}

void rspamd_srv_start_watching(struct rspamd_main *srv,
							   struct rspamd_worker *worker,
							   struct ev_loop *ev_base)
{
	g_assert(worker != NULL);

	worker->tmp_data = NULL;
	worker->srv_ev.data = worker;
	ev_io_init(&worker->srv_ev, rspamd_srv_handler, worker->srv_pipe[0], EV_READ);
	ev_io_start(ev_base, &worker->srv_ev);
}

struct rspamd_srv_request_data {
	struct rspamd_worker *worker;
	struct rspamd_srv_command cmd;
	gint attached_fd;
	struct rspamd_srv_reply rep;
	rspamd_srv_reply_handler handler;
	ev_io io_ev;
	gpointer ud;
};

static void
rspamd_srv_request_handler(EV_P_ ev_io *w, int revents)
{
	struct rspamd_srv_request_data *rd = (struct rspamd_srv_request_data *) w->data;
	struct msghdr msg;
	struct iovec iov;
	guchar fdspace[CMSG_SPACE(sizeof(int))];
	struct cmsghdr *cmsg;
	gssize r;
	gint rfd = -1;

	if (revents == EV_WRITE) {
		/* Send request to server */
		memset(&msg, 0, sizeof(msg));

		/* Attach fd to the message */
		if (rd->attached_fd != -1) {
			memset(fdspace, 0, sizeof(fdspace));
			msg.msg_control = fdspace;
			msg.msg_controllen = sizeof(fdspace);
			cmsg = CMSG_FIRSTHDR(&msg);
			cmsg->cmsg_level = SOL_SOCKET;
			cmsg->cmsg_type = SCM_RIGHTS;
			cmsg->cmsg_len = CMSG_LEN(sizeof(int));
			memcpy(CMSG_DATA(cmsg), &rd->attached_fd, sizeof(int));
		}

		iov.iov_base = &rd->cmd;
		iov.iov_len = sizeof(rd->cmd);
		msg.msg_iov = &iov;
		msg.msg_iovlen = 1;

		r = sendmsg(w->fd, &msg, 0);

		if (r == -1) {
			if (r == ENOBUFS) {
				/* On BSD derived systems we can have this error when trying to send
				 * requests too fast.
				 * It might be good to retry...
				 */
				msg_info("cannot write to server pipe: %s; command = %s; retrying sending",
						 strerror(errno),
						 rspamd_srv_command_to_string(rd->cmd.type));
				return;
			}
			msg_err("cannot write to server pipe: %s; command = %s", strerror(errno),
					rspamd_srv_command_to_string(rd->cmd.type));
			goto cleanup;
		}
		else if (r != sizeof(rd->cmd)) {
			msg_err("incomplete write to the server pipe: %d != %d, command = %s",
					(int) r, (int) sizeof(rd->cmd), rspamd_srv_command_to_string(rd->cmd.type));
			goto cleanup;
		}

		ev_io_stop(EV_A_ w);
		ev_io_set(w, rd->worker->srv_pipe[1], EV_READ);
		ev_io_start(EV_A_ w);
	}
	else {
		iov.iov_base = &rd->rep;
		iov.iov_len = sizeof(rd->rep);
		memset(&msg, 0, sizeof(msg));
		msg.msg_control = fdspace;
		msg.msg_controllen = sizeof(fdspace);
		msg.msg_iov = &iov;
		msg.msg_iovlen = 1;

		r = recvmsg(w->fd, &msg, 0);

		if (r == -1) {
			msg_err("cannot read from server pipe: %s; command = %s", strerror(errno),
					rspamd_srv_command_to_string(rd->cmd.type));
			goto cleanup;
		}

		if (r != (gint) sizeof(rd->rep)) {
			msg_err("cannot read from server pipe, invalid length: %d != %d; command = %s",
					(gint) r, (int) sizeof(rd->rep), rspamd_srv_command_to_string(rd->cmd.type));
			goto cleanup;
		}

		if (msg.msg_controllen >= CMSG_LEN(sizeof(int))) {
			rfd = *(int *) CMSG_DATA(CMSG_FIRSTHDR(&msg));
		}

		/* Reply has been received */
		if (rd->handler) {
			rd->handler(rd->worker, &rd->rep, rfd, rd->ud);
		}

		goto cleanup;
	}

	return;


cleanup:
	ev_io_stop(EV_A_ w);
	g_free(rd);
}

void rspamd_srv_send_command(struct rspamd_worker *worker,
							 struct ev_loop *ev_base,
							 struct rspamd_srv_command *cmd,
							 gint attached_fd,
							 rspamd_srv_reply_handler handler,
							 gpointer ud)
{
	struct rspamd_srv_request_data *rd;

	g_assert(cmd != NULL);
	g_assert(worker != NULL);

	rd = g_malloc0(sizeof(*rd));
	cmd->id = ottery_rand_uint64();
	memcpy(&rd->cmd, cmd, sizeof(rd->cmd));
	rd->handler = handler;
	rd->ud = ud;
	rd->worker = worker;
	rd->rep.id = cmd->id;
	rd->rep.type = cmd->type;
	rd->attached_fd = attached_fd;

	rd->io_ev.data = rd;
	ev_io_init(&rd->io_ev, rspamd_srv_request_handler,
			   rd->worker->srv_pipe[1], EV_WRITE);
	ev_io_start(ev_base, &rd->io_ev);
}

enum rspamd_control_type
rspamd_control_command_from_string(const gchar *str)
{
	enum rspamd_control_type ret = RSPAMD_CONTROL_MAX;

	if (!str) {
		return ret;
	}

	if (g_ascii_strcasecmp(str, "hyperscan_loaded") == 0) {
		ret = RSPAMD_CONTROL_HYPERSCAN_LOADED;
	}
	else if (g_ascii_strcasecmp(str, "stat") == 0) {
		ret = RSPAMD_CONTROL_STAT;
	}
	else if (g_ascii_strcasecmp(str, "reload") == 0) {
		ret = RSPAMD_CONTROL_RELOAD;
	}
	else if (g_ascii_strcasecmp(str, "reresolve") == 0) {
		ret = RSPAMD_CONTROL_RERESOLVE;
	}
	else if (g_ascii_strcasecmp(str, "recompile") == 0) {
		ret = RSPAMD_CONTROL_RECOMPILE;
	}
	else if (g_ascii_strcasecmp(str, "log_pipe") == 0) {
		ret = RSPAMD_CONTROL_LOG_PIPE;
	}
	else if (g_ascii_strcasecmp(str, "fuzzy_stat") == 0) {
		ret = RSPAMD_CONTROL_FUZZY_STAT;
	}
	else if (g_ascii_strcasecmp(str, "fuzzy_sync") == 0) {
		ret = RSPAMD_CONTROL_FUZZY_SYNC;
	}
	else if (g_ascii_strcasecmp(str, "monitored_change") == 0) {
		ret = RSPAMD_CONTROL_MONITORED_CHANGE;
	}
	else if (g_ascii_strcasecmp(str, "child_change") == 0) {
		ret = RSPAMD_CONTROL_CHILD_CHANGE;
	}

	return ret;
}

const gchar *
rspamd_control_command_to_string(enum rspamd_control_type cmd)
{
	const gchar *reply = "unknown";

	switch (cmd) {
	case RSPAMD_CONTROL_STAT:
		reply = "stat";
		break;
	case RSPAMD_CONTROL_RELOAD:
		reply = "reload";
		break;
	case RSPAMD_CONTROL_RERESOLVE:
		reply = "reresolve";
		break;
	case RSPAMD_CONTROL_RECOMPILE:
		reply = "recompile";
		break;
	case RSPAMD_CONTROL_HYPERSCAN_LOADED:
		reply = "hyperscan_loaded";
		break;
	case RSPAMD_CONTROL_LOG_PIPE:
		reply = "log_pipe";
		break;
	case RSPAMD_CONTROL_FUZZY_STAT:
		reply = "fuzzy_stat";
		break;
	case RSPAMD_CONTROL_FUZZY_SYNC:
		reply = "fuzzy_sync";
		break;
	case RSPAMD_CONTROL_MONITORED_CHANGE:
		reply = "monitored_change";
		break;
	case RSPAMD_CONTROL_CHILD_CHANGE:
		reply = "child_change";
		break;
	default:
		break;
	}

	return reply;
}

const gchar *rspamd_srv_command_to_string(enum rspamd_srv_type cmd)
{
	const gchar *reply = "unknown";

	switch (cmd) {
	case RSPAMD_SRV_SOCKETPAIR:
		reply = "socketpair";
		break;
	case RSPAMD_SRV_HYPERSCAN_LOADED:
		reply = "hyperscan_loaded";
		break;
	case RSPAMD_SRV_MONITORED_CHANGE:
		reply = "monitored_change";
		break;
	case RSPAMD_SRV_LOG_PIPE:
		reply = "log_pipe";
		break;
	case RSPAMD_SRV_ON_FORK:
		reply = "on_fork";
		break;
	case RSPAMD_SRV_HEARTBEAT:
		reply = "heartbeat";
		break;
	case RSPAMD_SRV_HEALTH:
		reply = "health";
		break;
	case RSPAMD_SRV_NOTICE_HYPERSCAN_CACHE:
		reply = "notice_hyperscan_cache";
		break;
	case RSPAMD_SRV_FUZZY_BLOCKED:
		reply = "fuzzy_blocked";
		break;
	}

	return reply;
}
