/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2009-2010 The FreeBSD Foundation
 *
 * This software was developed by Pawel Jakub Dawidek under sponsorship from
 * the FreeBSD Foundation.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/types.h>
#include <sys/queue.h>
#include <sys/socket.h>

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

#include "pjdlog.h"
#include "proto.h"
#include "proto_impl.h"

#define PROTO_CONN_MAGIC        0x907041c
struct proto_conn {
        int              pc_magic;
        struct proto    *pc_proto;
        void            *pc_ctx;
        int              pc_side;
#define PROTO_SIDE_CLIENT               0
#define PROTO_SIDE_SERVER_LISTEN        1
#define PROTO_SIDE_SERVER_WORK          2
};

static TAILQ_HEAD(, proto) protos = TAILQ_HEAD_INITIALIZER(protos);

void
proto_register(struct proto *proto, bool isdefault)
{
        static bool seen_default = false;

        if (!isdefault)
                TAILQ_INSERT_HEAD(&protos, proto, prt_next);
        else {
                PJDLOG_ASSERT(!seen_default);
                seen_default = true;
                TAILQ_INSERT_TAIL(&protos, proto, prt_next);
        }
}

static struct proto_conn *
proto_alloc(struct proto *proto, int side)
{
        struct proto_conn *conn;

        PJDLOG_ASSERT(proto != NULL);
        PJDLOG_ASSERT(side == PROTO_SIDE_CLIENT ||
            side == PROTO_SIDE_SERVER_LISTEN ||
            side == PROTO_SIDE_SERVER_WORK);

        conn = malloc(sizeof(*conn));
        if (conn != NULL) {
                conn->pc_proto = proto;
                conn->pc_side = side;
                conn->pc_magic = PROTO_CONN_MAGIC;
        }
        return (conn);
}

static void
proto_free(struct proto_conn *conn)
{

        PJDLOG_ASSERT(conn != NULL);
        PJDLOG_ASSERT(conn->pc_magic == PROTO_CONN_MAGIC);
        PJDLOG_ASSERT(conn->pc_side == PROTO_SIDE_CLIENT ||
            conn->pc_side == PROTO_SIDE_SERVER_LISTEN ||
            conn->pc_side == PROTO_SIDE_SERVER_WORK);
        PJDLOG_ASSERT(conn->pc_proto != NULL);

        bzero(conn, sizeof(*conn));
        free(conn);
}

static int
proto_common_setup(const char *srcaddr, const char *dstaddr,
    struct proto_conn **connp, int side)
{
        struct proto *proto;
        struct proto_conn *conn;
        void *ctx;
        int ret;

        PJDLOG_ASSERT(side == PROTO_SIDE_CLIENT ||
            side == PROTO_SIDE_SERVER_LISTEN);

        TAILQ_FOREACH(proto, &protos, prt_next) {
                if (side == PROTO_SIDE_CLIENT) {
                        if (proto->prt_client == NULL)
                                ret = -1;
                        else
                                ret = proto->prt_client(srcaddr, dstaddr, &ctx);
                } else /* if (side == PROTO_SIDE_SERVER_LISTEN) */ {
                        if (proto->prt_server == NULL)
                                ret = -1;
                        else
                                ret = proto->prt_server(dstaddr, &ctx);
                }
                /*
                 * ret == 0  - success
                 * ret == -1 - dstaddr is not for this protocol
                 * ret > 0   - right protocol, but an error occurred
                 */
                if (ret >= 0)
                        break;
        }
        if (proto == NULL) {
                /* Unrecognized address. */
                errno = EINVAL;
                return (-1);
        }
        if (ret > 0) {
                /* An error occurred. */
                errno = ret;
                return (-1);
        }
        conn = proto_alloc(proto, side);
        if (conn == NULL) {
                if (proto->prt_close != NULL)
                        proto->prt_close(ctx);
                errno = ENOMEM;
                return (-1);
        }
        conn->pc_ctx = ctx;
        *connp = conn;

        return (0);
}

int
proto_client(const char *srcaddr, const char *dstaddr,
    struct proto_conn **connp)
{

        return (proto_common_setup(srcaddr, dstaddr, connp, PROTO_SIDE_CLIENT));
}

int
proto_connect(struct proto_conn *conn, int timeout)
{
        int ret;

        PJDLOG_ASSERT(conn != NULL);
        PJDLOG_ASSERT(conn->pc_magic == PROTO_CONN_MAGIC);
        PJDLOG_ASSERT(conn->pc_side == PROTO_SIDE_CLIENT);
        PJDLOG_ASSERT(conn->pc_proto != NULL);
        PJDLOG_ASSERT(conn->pc_proto->prt_connect != NULL);
        PJDLOG_ASSERT(timeout >= -1);

        ret = conn->pc_proto->prt_connect(conn->pc_ctx, timeout);
        if (ret != 0) {
                errno = ret;
                return (-1);
        }

        return (0);
}

int
proto_connect_wait(struct proto_conn *conn, int timeout)
{
        int ret;

        PJDLOG_ASSERT(conn != NULL);
        PJDLOG_ASSERT(conn->pc_magic == PROTO_CONN_MAGIC);
        PJDLOG_ASSERT(conn->pc_side == PROTO_SIDE_CLIENT);
        PJDLOG_ASSERT(conn->pc_proto != NULL);
        PJDLOG_ASSERT(conn->pc_proto->prt_connect_wait != NULL);
        PJDLOG_ASSERT(timeout >= 0);

        ret = conn->pc_proto->prt_connect_wait(conn->pc_ctx, timeout);
        if (ret != 0) {
                errno = ret;
                return (-1);
        }

        return (0);
}

int
proto_server(const char *addr, struct proto_conn **connp)
{

        return (proto_common_setup(NULL, addr, connp, PROTO_SIDE_SERVER_LISTEN));
}

int
proto_accept(struct proto_conn *conn, struct proto_conn **newconnp)
{
        struct proto_conn *newconn;
        int ret;

        PJDLOG_ASSERT(conn != NULL);
        PJDLOG_ASSERT(conn->pc_magic == PROTO_CONN_MAGIC);
        PJDLOG_ASSERT(conn->pc_side == PROTO_SIDE_SERVER_LISTEN);
        PJDLOG_ASSERT(conn->pc_proto != NULL);
        PJDLOG_ASSERT(conn->pc_proto->prt_accept != NULL);

        newconn = proto_alloc(conn->pc_proto, PROTO_SIDE_SERVER_WORK);
        if (newconn == NULL)
                return (-1);

        ret = conn->pc_proto->prt_accept(conn->pc_ctx, &newconn->pc_ctx);
        if (ret != 0) {
                proto_free(newconn);
                errno = ret;
                return (-1);
        }

        *newconnp = newconn;

        return (0);
}

int
proto_send(const struct proto_conn *conn, const void *data, size_t size)
{
        int ret;

        PJDLOG_ASSERT(conn != NULL);
        PJDLOG_ASSERT(conn->pc_magic == PROTO_CONN_MAGIC);
        PJDLOG_ASSERT(conn->pc_proto != NULL);
        PJDLOG_ASSERT(conn->pc_proto->prt_send != NULL);

        ret = conn->pc_proto->prt_send(conn->pc_ctx, data, size, -1);
        if (ret != 0) {
                errno = ret;
                return (-1);
        }
        return (0);
}

int
proto_recv(const struct proto_conn *conn, void *data, size_t size)
{
        int ret;

        PJDLOG_ASSERT(conn != NULL);
        PJDLOG_ASSERT(conn->pc_magic == PROTO_CONN_MAGIC);
        PJDLOG_ASSERT(conn->pc_proto != NULL);
        PJDLOG_ASSERT(conn->pc_proto->prt_recv != NULL);

        ret = conn->pc_proto->prt_recv(conn->pc_ctx, data, size, NULL);
        if (ret != 0) {
                errno = ret;
                return (-1);
        }
        return (0);
}

int
proto_connection_send(const struct proto_conn *conn, struct proto_conn *mconn)
{
        const char *protoname;
        int ret, fd;

        PJDLOG_ASSERT(conn != NULL);
        PJDLOG_ASSERT(conn->pc_magic == PROTO_CONN_MAGIC);
        PJDLOG_ASSERT(conn->pc_proto != NULL);
        PJDLOG_ASSERT(conn->pc_proto->prt_send != NULL);
        PJDLOG_ASSERT(mconn != NULL);
        PJDLOG_ASSERT(mconn->pc_magic == PROTO_CONN_MAGIC);
        PJDLOG_ASSERT(mconn->pc_proto != NULL);
        fd = proto_descriptor(mconn);
        PJDLOG_ASSERT(fd >= 0);
        protoname = mconn->pc_proto->prt_name;
        PJDLOG_ASSERT(protoname != NULL);

        ret = conn->pc_proto->prt_send(conn->pc_ctx,
            (const unsigned char *)protoname, strlen(protoname) + 1, fd);
        proto_close(mconn);
        if (ret != 0) {
                errno = ret;
                return (-1);
        }
        return (0);
}

int
proto_connection_recv(const struct proto_conn *conn, bool client,
    struct proto_conn **newconnp)
{
        char protoname[128];
        struct proto *proto;
        struct proto_conn *newconn;
        int ret, fd;

        PJDLOG_ASSERT(conn != NULL);
        PJDLOG_ASSERT(conn->pc_magic == PROTO_CONN_MAGIC);
        PJDLOG_ASSERT(conn->pc_proto != NULL);
        PJDLOG_ASSERT(conn->pc_proto->prt_recv != NULL);
        PJDLOG_ASSERT(newconnp != NULL);

        bzero(protoname, sizeof(protoname));

        ret = conn->pc_proto->prt_recv(conn->pc_ctx, (unsigned char *)protoname,
            sizeof(protoname) - 1, &fd);
        if (ret != 0) {
                errno = ret;
                return (-1);
        }

        PJDLOG_ASSERT(fd >= 0);

        TAILQ_FOREACH(proto, &protos, prt_next) {
                if (strcmp(proto->prt_name, protoname) == 0)
                        break;
        }
        if (proto == NULL) {
                errno = EINVAL;
                return (-1);
        }

        newconn = proto_alloc(proto,
            client ? PROTO_SIDE_CLIENT : PROTO_SIDE_SERVER_WORK);
        if (newconn == NULL)
                return (-1);
        PJDLOG_ASSERT(newconn->pc_proto->prt_wrap != NULL);
        ret = newconn->pc_proto->prt_wrap(fd, client, &newconn->pc_ctx);
        if (ret != 0) {
                proto_free(newconn);
                errno = ret;
                return (-1);
        }

        *newconnp = newconn;

        return (0);
}

int
proto_descriptor(const struct proto_conn *conn)
{

        PJDLOG_ASSERT(conn != NULL);
        PJDLOG_ASSERT(conn->pc_magic == PROTO_CONN_MAGIC);
        PJDLOG_ASSERT(conn->pc_proto != NULL);
        PJDLOG_ASSERT(conn->pc_proto->prt_descriptor != NULL);

        return (conn->pc_proto->prt_descriptor(conn->pc_ctx));
}

bool
proto_address_match(const struct proto_conn *conn, const char *addr)
{

        PJDLOG_ASSERT(conn != NULL);
        PJDLOG_ASSERT(conn->pc_magic == PROTO_CONN_MAGIC);
        PJDLOG_ASSERT(conn->pc_proto != NULL);
        PJDLOG_ASSERT(conn->pc_proto->prt_address_match != NULL);

        return (conn->pc_proto->prt_address_match(conn->pc_ctx, addr));
}

void
proto_local_address(const struct proto_conn *conn, char *addr, size_t size)
{

        PJDLOG_ASSERT(conn != NULL);
        PJDLOG_ASSERT(conn->pc_magic == PROTO_CONN_MAGIC);
        PJDLOG_ASSERT(conn->pc_proto != NULL);
        PJDLOG_ASSERT(conn->pc_proto->prt_local_address != NULL);

        conn->pc_proto->prt_local_address(conn->pc_ctx, addr, size);
}

void
proto_remote_address(const struct proto_conn *conn, char *addr, size_t size)
{

        PJDLOG_ASSERT(conn != NULL);
        PJDLOG_ASSERT(conn->pc_magic == PROTO_CONN_MAGIC);
        PJDLOG_ASSERT(conn->pc_proto != NULL);
        PJDLOG_ASSERT(conn->pc_proto->prt_remote_address != NULL);

        conn->pc_proto->prt_remote_address(conn->pc_ctx, addr, size);
}

int
proto_timeout(const struct proto_conn *conn, int timeout)
{
        struct timeval tv;
        int fd;

        PJDLOG_ASSERT(conn != NULL);
        PJDLOG_ASSERT(conn->pc_magic == PROTO_CONN_MAGIC);
        PJDLOG_ASSERT(conn->pc_proto != NULL);

        fd = proto_descriptor(conn);
        if (fd == -1)
                return (-1);

        tv.tv_sec = timeout;
        tv.tv_usec = 0;
        if (setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv)) == -1)
                return (-1);
        if (setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv)) == -1)
                return (-1);

        return (0);
}

void
proto_close(struct proto_conn *conn)
{

        PJDLOG_ASSERT(conn != NULL);
        PJDLOG_ASSERT(conn->pc_magic == PROTO_CONN_MAGIC);
        PJDLOG_ASSERT(conn->pc_proto != NULL);
        PJDLOG_ASSERT(conn->pc_proto->prt_close != NULL);

        conn->pc_proto->prt_close(conn->pc_ctx);
        proto_free(conn);
}