/*
	 * Copyright 2010-2024 Red Hat, Inc.
	 *
	 * Author: Angus Salkeld <asalkeld@redhat.com>
	 *
	 * This file is part of libqb.
	 *
	 * libqb is free software: you can redistribute it and/or modify
	 * it under the terms of the GNU Lesser General Public License as published by
	 * the Free Software Foundation, either version 2.1 of the License, or
	 * (at your option) any later version.
	 *
	 * libqb 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 Lesser General Public License for more details.
	 *
	 * You should have received a copy of the GNU Lesser General Public License
	 * along with libqb.  If not, see <http://www.gnu.org/licenses/>.
	 */
	#include "os_base.h"
	#include <poll.h>
	
	#include "ipc_int.h"
	#include "util_int.h"
	#include <qb/qbdefs.h>
	#include <qb/qbipcc.h>
	
	qb_ipcc_connection_t *

	qb_ipcc_connect(const char *name, size_t max_msg_size)
	{
		int32_t res;
		qb_ipcc_connection_t *c = NULL;
		struct qb_ipc_connection_response response;
	
		c = calloc(1, sizeof(struct qb_ipcc_connection));

		if (c == NULL) {
			return NULL;

		}
	

		c->setup.max_msg_size = QB_MAX(max_msg_size,
					       sizeof(struct qb_ipc_connection_response));
		(void)strlcpy(c->name, name, NAME_MAX);
		res = qb_ipcc_us_setup_connect(c, &response);

		if (res < 0) {

			goto disconnect_and_cleanup;
		}
		qb_ipc_us_ready(&c->setup, NULL, -1, POLLIN);
		res = qb_ipcc_connect_continue(c);
		if (res != 0) {
			/* qb_ipcc_connect_continue() has cleaned up for us */
			errno = -res;
			return NULL;
		}
	
		return c;
	

	disconnect_and_cleanup:

		if (c->setup.u.us.sock >= 0) {
			qb_ipcc_us_sock_close(c->setup.u.us.sock);
		}
		free(c->receive_buf);
		free(c);
		errno = -res;
		return NULL;
	}
	
	qb_ipcc_connection_t *
	qb_ipcc_connect_async(const char *name, size_t max_msg_size, int *connect_fd)
	{
		int32_t res;
		qb_ipcc_connection_t *c = NULL;
		struct qb_ipc_connection_response response;
	
		c = calloc(1, sizeof(struct qb_ipcc_connection));
		if (c == NULL) {
			return NULL;
		}
	
		c->setup.max_msg_size = QB_MAX(max_msg_size,
					       sizeof(struct qb_ipc_connection_response));
		(void)strlcpy(c->name, name, NAME_MAX);
		res = qb_ipcc_us_setup_connect(c, &response);
		if (res < 0) {
			goto disconnect_and_cleanup;
		}
	
		*connect_fd = c->setup.u.us.sock;
		return c;
	
	disconnect_and_cleanup:
		if (c->setup.u.us.sock >= 0) {
			qb_ipcc_us_sock_close(c->setup.u.us.sock);
		}
		free(c->receive_buf);
		free(c);
		errno = -res;
		return NULL;
	}
	
	int qb_ipcc_connect_continue(struct qb_ipcc_connection * c)
	{
		struct qb_ipc_connection_response response;
		int32_t res;
	
		/* Finish up the authentication part */
		res = qb_ipcc_setup_connect_continue(c, &response);
		if (res != 0) {
			goto disconnect_and_cleanup;
		}
	
		c->response.type = response.connection_type;
		c->request.type = response.connection_type;
		c->event.type = response.connection_type;
		c->setup.type = response.connection_type;
	
		c->response.max_msg_size = response.max_msg_size;
		c->request.max_msg_size = response.max_msg_size;
		c->event.max_msg_size = response.max_msg_size;
		c->receive_buf = calloc(1, response.max_msg_size);
		c->fc_enable_max = 1;
		if (c->receive_buf == NULL) {
			res = -ENOMEM;
			goto disconnect_and_cleanup;
		}
	
		switch (c->request.type) {
		case QB_IPC_SHM:
			res = qb_ipcc_shm_connect(c, &response);
			break;
		case QB_IPC_SOCKET:
			res = qb_ipcc_us_connect(c, &response);
			break;
		case QB_IPC_POSIX_MQ:
		case QB_IPC_SYSV_MQ:
			res = -ENOTSUP;
			break;
		default:
			res = -EINVAL;
			break;
		}
		if (res != 0) {
			goto disconnect_and_cleanup;
		}
		c->is_connected = QB_TRUE;
		return 0;
	
	disconnect_and_cleanup:
		if (c->setup.u.us.sock >= 0) {
			qb_ipcc_us_sock_close(c->setup.u.us.sock);
		}
		free(c->receive_buf);
		free(c);
		errno = -res;
		return res;
	
	}
	
	static int32_t
	_check_connection_state_with(struct qb_ipcc_connection * c, int32_t res,
				     struct qb_ipc_one_way * one_way,
				     int32_t ms_timeout, int32_t events)
	{
		if (res >= 0) return res;
	
		if (qb_ipc_us_sock_error_is_disconnected(res)) {
			errno = -res;
			qb_util_perror(LOG_DEBUG,
				       "interpreting result %d as a disconnect",
				       res);
			c->is_connected = QB_FALSE;
		}
	
		if (res == -EAGAIN || res == -ETIMEDOUT) {
			int32_t res2;
			int32_t poll_ms = ms_timeout;
			if (res == -ETIMEDOUT) {
				poll_ms = 0;
			}
			res2 = qb_ipc_us_ready(one_way, &c->setup, poll_ms, events);
			if (qb_ipc_us_sock_error_is_disconnected(res2)) {
				errno = -res2;
				qb_util_perror(LOG_DEBUG,
					       "%s %d %s",
					       "interpreting result",
					       res2,
					       "(from socket) as a disconnect");
				c->is_connected = QB_FALSE;
				res = res2;
			} else if (res != -ETIMEDOUT) {
				/* if the result we're checking against is a TIMEOUT error.
				 * don't override that result with another error that does
				 * not imply a disconnect */
				res = res2;
			}
		}
		return res;
	}
	
	
	static int32_t
	_check_connection_state(struct qb_ipcc_connection * c, int32_t res)
	{
		if (res >= 0) return res;
	
		if (qb_ipc_us_sock_error_is_disconnected(res)) {
			errno = -res;
			qb_util_perror(LOG_DEBUG,
				    "interpreting result %d as a disconnect",
				    res);
			c->is_connected = QB_FALSE;
		}
		return res;
	}
	
	static struct qb_ipc_one_way *
	_event_sock_one_way_get(struct qb_ipcc_connection * c)
	{
		if (c->needs_sock_for_poll) {
			return &c->setup;
		}
		return &c->event;
	}
	
	static struct qb_ipc_one_way *
	_response_sock_one_way_get(struct qb_ipcc_connection * c)
	{
		if (c->needs_sock_for_poll) {
			return &c->setup;
		}
		return &c->response;
	}
	
	ssize_t
	qb_ipcc_send(struct qb_ipcc_connection * c, const void *msg_ptr, size_t msg_len)
	{
		ssize_t res;
		ssize_t res2;
	
		if (c == NULL) {
			return -EINVAL;
		}
		if (msg_len > c->request.max_msg_size) {
			return -EMSGSIZE;
		}
		if (c->funcs.fc_get) {
			res = c->funcs.fc_get(&c->request);
			if (res < 0) {
				return res;
			} else if (res > 0 && res <= c->fc_enable_max) {
				return -EAGAIN;
			} else {
				/*
				 * we can transmit
				 */
			}
		}
	
		res = c->funcs.send(&c->request, msg_ptr, msg_len);
		if (res == msg_len && c->needs_sock_for_poll) {
			do {
				res2 = qb_ipc_us_send(&c->setup, msg_ptr, 1);
			} while (res2 == -EAGAIN);
			if (res2 == -EPIPE) {
				res2 = -ENOTCONN;
			}
			if (res2 != 1) {
				res = res2;
			}
		}
		return _check_connection_state(c, res);
	}
	
	int32_t
	qb_ipcc_fc_enable_max_set(struct qb_ipcc_connection * c, uint32_t max)
	{
		if (c == NULL || max > 2) {
			return -EINVAL;
		}
		c->fc_enable_max = max;
		return 0;
	}
	
	ssize_t
	qb_ipcc_sendv(struct qb_ipcc_connection * c, const struct iovec * iov,
		      size_t iov_len)
	{
		int32_t total_size = 0;
		int32_t i;
		int32_t res;
		int32_t res2;
	
		for (i = 0; i < iov_len; i++) {
			total_size += iov[i].iov_len;
		}
		if (c == NULL) {
			return -EINVAL;
		}
		if (total_size > c->request.max_msg_size) {
			return -EMSGSIZE;
		}
	
		if (c->funcs.fc_get) {
			res = c->funcs.fc_get(&c->request);
			if (res < 0) {
				return res;
			} else if (res > 0 && res <= c->fc_enable_max) {
				return -EAGAIN;
			} else {
				/*
				 * we can transmit
				 */
			}
		}
	
		res = c->funcs.sendv(&c->request, iov, iov_len);
		if (res > 0 && c->needs_sock_for_poll) {
			do {
				res2 = qb_ipc_us_send(&c->setup, &res, 1);
			} while (res2 == -EAGAIN);
			if (res2 == -EPIPE) {
				res2 = -ENOTCONN;
			}
			if (res2 != 1) {
				res = res2;
			}
		}
		return _check_connection_state(c, res);
	}
	
	ssize_t
	qb_ipcc_recv(struct qb_ipcc_connection * c, void *msg_ptr,
		     size_t msg_len, int32_t ms_timeout)
	{
		int32_t res = 0;
		int32_t connect_res = 0;
	
		if (c == NULL) {
			return -EINVAL;
		}
	
		res = c->funcs.recv(&c->response, msg_ptr, msg_len, ms_timeout);
		if (res >= 0) {
			return res;
		}
	
		/* if we didn't get a msg, check connection state */
		connect_res = _check_connection_state_with(c, res,
						    _response_sock_one_way_get(c),
						    ms_timeout, POLLIN);
	
		/* only report the connection state check result if an error is returned. */
		if (connect_res < 0) {
			return connect_res;
		}
		return res;
	}
	
	ssize_t
	qb_ipcc_sendv_recv(qb_ipcc_connection_t * c,
			   const struct iovec * iov, uint32_t iov_len,
			   void *res_msg, size_t res_len, int32_t ms_timeout)
	{
		ssize_t res = 0;
		int32_t timeout_now;
		int32_t timeout_rem = ms_timeout;
	
		if (c == NULL) {
			return -EINVAL;
		}
	
		if (c->funcs.fc_get) {
			res = c->funcs.fc_get(&c->request);
			if (res < 0) {
				return res;
			} else if (res > 0 && res <= c->fc_enable_max) {
				return -EAGAIN;
			} else {
				/*
				 * we can transmit
				 */
			}
		}
	
		res = qb_ipcc_sendv(c, iov, iov_len);
		if (res < 0) {
			return res;
		}
	
		do {
			/* following is a liveness-driven interleaving
			   (for cases the server side failed/exited) */
			if (timeout_rem > QB_IPC_MAX_WAIT_MS || ms_timeout == -1) {
				timeout_now = QB_IPC_MAX_WAIT_MS;
			} else {
				timeout_now = timeout_rem;
			}
	
			res = qb_ipcc_recv(c, res_msg, res_len, timeout_now);
			if (res == -ETIMEDOUT) {
				if (ms_timeout < 0) {
					res = -EAGAIN;
				} else {
					timeout_rem -= timeout_now;
					if (timeout_rem > 0) {
						res = -EAGAIN;
					}
				}
			} else	if (res < 0 && res != -EAGAIN) {
				errno = -res;
				qb_util_perror(LOG_DEBUG,
					       "qb_ipcc_recv %d timeout:(%d/%d)",
					       res, timeout_now, timeout_rem);
			}
		} while (res == -EAGAIN && c->is_connected);
	
		return res;
	}
	
	int32_t
	qb_ipcc_fd_get(struct qb_ipcc_connection * c, int32_t * fd)
	{
		if (c == NULL) {
			return -EINVAL;
		}
		if (c->event.type == QB_IPC_SOCKET) {
			*fd = c->event.u.us.sock;
		} else {
			*fd = c->setup.u.us.sock;
		}
		return 0;
	}
	
	int32_t
	qb_ipcc_auth_get(struct qb_ipcc_connection * c, pid_t *pid, uid_t *uid, gid_t *gid)
	{
		if (c == NULL) {
			return -EINVAL;
		}
		if (pid) {
			*pid = c->server_pid;
		}
		if (uid) {
			*uid = c->euid;
		}
		if (gid) {
			*gid = c->egid;
		}
		return 0;
	}
	
	ssize_t
	qb_ipcc_event_recv(struct qb_ipcc_connection * c, void *msg_pt,
			   size_t msg_len, int32_t ms_timeout)
	{
		char one_byte = 1;
		int32_t res;
		ssize_t size;
	
		if (c == NULL) {
			return -EINVAL;
		}
		res = _check_connection_state_with(c, -EAGAIN, _event_sock_one_way_get(c),
						   ms_timeout, POLLIN);
		if (res < 0) {
			return res;
		}
		size = c->funcs.recv(&c->event, msg_pt, msg_len, ms_timeout);
		if (size > 0 && c->needs_sock_for_poll) {
			res = qb_ipc_us_recv(&c->setup, &one_byte, 1, -1);
			if (res != 1) {
				size = res;
			}
		}
		return _check_connection_state(c, size);
	}
	
	void
	qb_ipcc_disconnect(struct qb_ipcc_connection *c)
	{
		struct qb_ipc_one_way *ow = NULL;
	
		qb_util_log(LOG_TRACE, "%s(%s)", __func__, (c == NULL)? "NULL" : "");
	
		if (c == NULL) {
			return;
		}
	
		ow = _event_sock_one_way_get(c);
		(void)_check_connection_state_with(c, -EAGAIN, ow, 0, POLLIN);
	
		if (c->funcs.disconnect) {
			c->funcs.disconnect(c);
		}
		free(c->receive_buf);
		free(c);
	}
	
	void
	qb_ipcc_context_set(struct qb_ipcc_connection *c, void *context)
	{
		if (c == NULL) {
			return;
		}
		c->context = context;
	}
	
	void *qb_ipcc_context_get(struct qb_ipcc_connection *c)
	{
		if (c == NULL) {
			return NULL;
		}
		return c->context;
	}
	
	int32_t
	qb_ipcc_is_connected(qb_ipcc_connection_t *c)
	{
		struct qb_ipc_one_way *ow;
	
		if (c == NULL) {
			return QB_FALSE;
		}
	
		ow = _response_sock_one_way_get(c);
		(void)_check_connection_state_with(c, -EAGAIN, ow, 0, POLLIN);
	
		return c->is_connected;
	}
	
	int32_t
	qb_ipcc_get_buffer_size(qb_ipcc_connection_t * c)
	{
		if (c == NULL) {
			return -EINVAL;
		}
	
		return c->event.max_msg_size;
	}