/*
 * Copyright (C) 2014-2015 The Android Open Source Project
 *
 * 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 <assert.h>
#include <lk/list.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <trusty/time.h>
#include <trusty_ipc.h>
#include <uapi/err.h>

#define TLOG_TAG "ipc-unittest-srv"

#include <app/ipc_unittest/common.h>
#include <ipc_unittest_uuid_consts.h>

typedef void (*event_handler_proc_t)(const uevent_t* ev);

typedef struct tipc_event_handler {
    event_handler_proc_t proc;
    void* priv;
} tipc_event_handler_t;

typedef struct tipc_srv {
    const char* name;
    unsigned int msg_num;
    size_t msg_size;
    unsigned int port_flags;
    size_t port_state_size;
    size_t chan_state_size;
    event_handler_proc_t port_handler;
    event_handler_proc_t chan_handler;
} tipc_srv_t;

typedef struct tipc_srv_state {
    const struct tipc_srv* service;
    handle_t port;
    void* priv;
    tipc_event_handler_t handler;
} tipc_srv_state_t;

/* closer services */
static void closer1_handle_port(const uevent_t* ev);

typedef struct closer1_state {
    unsigned int conn_cnt;
} closer1_state_t;

static void closer2_handle_port(const uevent_t* ev);

typedef struct closer2_state {
    unsigned int conn_cnt;
} closer2_state_t;

static void closer3_handle_port(const uevent_t* ev);

typedef struct closer3_state {
    handle_t chans[4];
    unsigned int chan_cnt;
} closer3_state_t;

/* connect service */
static void connect_handle_port(const uevent_t* ev);

/* datasync service */
static void datasink_handle_port(const uevent_t* ev);
static void datasink_handle_chan(const uevent_t* ev);

/* datasink service has no per channel state so we can
 * just attach handler struct directly to channel handle
 */
static struct tipc_event_handler _datasink_chan_handler = {
        .proc = datasink_handle_chan,
        .priv = NULL,
};

/* echo service */
static void echo_handle_port(const uevent_t* ev);
static void echo_handle_chan(const uevent_t* ev);

struct echo_msg {
    uint8_t msg_buf[MAX_PORT_BUF_SIZE];
    size_t msg_len;
    handle_t handles[IPC_MAX_MSG_HANDLES];
    size_t handle_cnt;
};

typedef struct echo_chan_state {
    struct tipc_event_handler handler;
    unsigned int msg_max_num;
    struct echo_msg echo_msgs[];
} echo_chan_state_t;

/* uuid service */
static void uuid_handle_port(const uevent_t* ev);

/* Other globals */
static bool stopped = false;

/************************************************************************/

#define IPC_PORT_ALLOW_ALL \
    (IPC_PORT_ALLOW_NS_CONNECT | IPC_PORT_ALLOW_TA_CONNECT)

#define SRV_NAME(name) SRV_PATH_BASE ".srv." name

static const struct tipc_srv _services[] = {
        {
                .name = SRV_NAME("closer1"),
                .msg_num = 2,
                .msg_size = 64,
                .port_flags = IPC_PORT_ALLOW_ALL,
                .port_handler = closer1_handle_port,
                .port_state_size = sizeof(struct closer1_state),
                .chan_handler = NULL,
        },
        {
                .name = SRV_NAME("closer2"),
                .msg_num = 2,
                .msg_size = 64,
                .port_flags = IPC_PORT_ALLOW_ALL,
                .port_handler = closer2_handle_port,
                .port_state_size = sizeof(struct closer2_state),
                .chan_handler = NULL,
        },
        {
                .name = SRV_NAME("closer3"),
                .msg_num = 2,
                .msg_size = 64,
                .port_flags = IPC_PORT_ALLOW_ALL,
                .port_handler = closer3_handle_port,
                .port_state_size = sizeof(struct closer3_state),
                .chan_handler = NULL,
        },
        {
                .name = SRV_NAME("connect"),
                .msg_num = 2,
                .msg_size = 64,
                .port_flags = IPC_PORT_ALLOW_TA_CONNECT,
                .port_handler = connect_handle_port,
                .chan_handler = NULL,
        },
        /* datasink services */
        {
                .name = SRV_NAME("datasink"),
                .msg_num = 2,
                .msg_size = 64,
                .port_flags = IPC_PORT_ALLOW_ALL,
                .port_handler = datasink_handle_port,
                .chan_handler = NULL,
        },
        {
                .name = SRV_NAME("ns_only"),
                .msg_num = 8,
                .msg_size = 64,
                .port_flags = IPC_PORT_ALLOW_NS_CONNECT,
                .port_handler = datasink_handle_port,
                .chan_handler = NULL,
        },
        {
                .name = SRV_NAME("ta_only"),
                .msg_num = 8,
                .msg_size = 64,
                .port_flags = IPC_PORT_ALLOW_TA_CONNECT,
                .port_handler = datasink_handle_port,
                .chan_handler = NULL,
        },
        /* echo */
        {
                .name = SRV_NAME("echo"),
                .msg_num = 8,
                .msg_size = MAX_PORT_BUF_SIZE,
                .port_flags = IPC_PORT_ALLOW_ALL,
                .port_handler = echo_handle_port,
                .chan_handler = echo_handle_chan,
        },
        /* uuid  test */
        {
                .name = SRV_NAME("uuid"),
                .msg_num = 2,
                .msg_size = 64,
                .port_flags = IPC_PORT_ALLOW_ALL,
                .port_handler = uuid_handle_port,
                .chan_handler = NULL,
        },
};

static struct tipc_srv_state _srv_states[countof(_services)] = {
        [0 ...(countof(_services) - 1)] =
                {
                        .port = INVALID_IPC_HANDLE,
                },
};

/************************************************************************/

static struct tipc_srv_state* get_srv_state(const uevent_t* ev) {
    return containerof(ev->cookie, struct tipc_srv_state, handler);
}

static void _destroy_service(struct tipc_srv_state* state) {
    if (!state) {
        TLOGI("non-null state expected\n");
        return;
    }

    /* free state if any */
    if (state->priv) {
        free(state->priv);
        state->priv = NULL;
    }

    /* close port */
    if (state->port != INVALID_IPC_HANDLE) {
        int rc = close(state->port);
        if (rc != NO_ERROR) {
            TLOGI("Failed (%d) to close port %d\n", rc, state->port);
        }
        state->port = INVALID_IPC_HANDLE;
    }

    /* reset handler */
    state->service = NULL;
    state->handler.proc = NULL;
    state->handler.priv = NULL;
}

/*
 *  Create service
 */
static int _create_service(const struct tipc_srv* srv,
                           struct tipc_srv_state* state) {
    if (!srv || !state) {
        TLOGI("null services specified\n");
        return ERR_INVALID_ARGS;
    }

    /* create port */
    int rc = port_create(srv->name, srv->msg_num, srv->msg_size,
                         srv->port_flags);
    if (rc < 0) {
        TLOGI("Failed (%d) to create port\n", rc);
        return rc;
    }

    /* setup port state  */
    state->port = (handle_t)rc;
    state->handler.proc = srv->port_handler;
    state->handler.priv = state;
    state->service = srv;
    state->priv = NULL;

    if (srv->port_state_size) {
        /* allocate port state */
        state->priv = calloc(1, srv->port_state_size);
        if (!state->priv) {
            rc = ERR_NO_MEMORY;
            goto err_calloc;
        }
    }

    /* attach handler to port handle */
    rc = set_cookie(state->port, &state->handler);
    if (rc < 0) {
        TLOGI("Failed (%d) to set cookie on port %d\n", rc, state->port);
        goto err_set_cookie;
    }

    return NO_ERROR;

err_calloc:
err_set_cookie:
    _destroy_service(state);
    return rc;
}

/*
 *  Restart specified service
 */
static int restart_service(struct tipc_srv_state* state) {
    if (!state) {
        TLOGI("non-null state expected\n");
        return ERR_INVALID_ARGS;
    }

    const struct tipc_srv* srv = state->service;
    _destroy_service(state);
    return _create_service(srv, state);
}

/*
 *  Kill all servoces
 */
static void kill_services(void) {
    TLOGD("Terminating unittest services\n");

    /* close any opened ports */
    for (unsigned int i = 0; i < countof(_services); i++) {
        _destroy_service(&_srv_states[i]);
    }
}

/*
 *  Initialize all services
 */
static int init_services(void) {
    TLOGD("Init unittest services!!!\n");

    for (unsigned int i = 0; i < countof(_services); i++) {
        int rc = _create_service(&_services[i], &_srv_states[i]);
        if (rc < 0) {
            TLOGI("Failed (%d) to create service %s\n", rc, _services[i].name);
            return rc;
        }
    }

    return 0;
}

/*
 *  Handle common port errors
 */
static bool handle_port_errors(const uevent_t* ev) {
    if ((ev->event & IPC_HANDLE_POLL_ERROR) ||
        (ev->event & IPC_HANDLE_POLL_HUP) ||
        (ev->event & IPC_HANDLE_POLL_MSG) ||
        (ev->event & IPC_HANDLE_POLL_SEND_UNBLOCKED)) {
        /* should never happen with port handles */
        TLOGI("error event (0x%x) for port (%d)\n", ev->event, ev->handle);

        /* recreate service */
        restart_service(get_srv_state(ev));
        return true;
    }

    return false;
}

/****************************** connect test service *********************/

/*
 *  Local wrapper on top of async connect that provides
 *  synchronos connect with timeout.
 */
int sync_connect(const char* path, unsigned int timeout) {
    int rc;
    uevent_t evt;
    handle_t chan;

    rc = connect(path, IPC_CONNECT_ASYNC | IPC_CONNECT_WAIT_FOR_PORT);
    if (rc >= 0) {
        chan = (handle_t)rc;
        rc = wait(chan, &evt, timeout);
        if (rc == 0) {
            rc = ERR_BAD_STATE;
            if (evt.handle == chan) {
                if (evt.event & IPC_HANDLE_POLL_READY)
                    return chan;

                if (evt.event & IPC_HANDLE_POLL_HUP)
                    rc = ERR_CHANNEL_CLOSED;
            }
        }
        close(chan);
    }
    return rc;
}

static void connect_handle_port(const uevent_t* ev) {
    uuid_t peer_uuid;

    if (handle_port_errors(ev))
        return;

    if (ev->event & IPC_HANDLE_POLL_READY) {
        char path[MAX_PORT_PATH_LEN];

        /* accept incomming connection and close it */
        int rc = accept(ev->handle, &peer_uuid);
        if (rc < 0 && rc != ERR_CHANNEL_CLOSED) {
            TLOGI("accept failed (%d)\n", rc);
            return;
        }
        if (rc >= 0) {
            close((handle_t)rc);
        }

        /* but then issue a series of connect requests */
        for (unsigned int i = FIRST_FREE_HANDLE; i < MAX_USER_HANDLES; i++) {
            sprintf(path, "%s.port.accept%d", SRV_PATH_BASE, i);
            rc = sync_connect(path, 1000);
            close((handle_t)rc);
        }
    }
}

/****************************** closer services **************************/

static void closer1_handle_port(const uevent_t* ev) {
    uuid_t peer_uuid;
    struct closer1_state* st = get_srv_state(ev)->priv;

    if (handle_port_errors(ev))
        return;

    if (ev->event & IPC_HANDLE_POLL_READY) {
        /* new connection request, bump counter */
        st->conn_cnt++;

        /* accept it */
        int rc = accept(ev->handle, &peer_uuid);
        if (rc < 0) {
            TLOGI("accept failed (%d)\n", rc);
            return;
        }
        handle_t chan = (handle_t)rc;

        if (st->conn_cnt & 1) {
            /* sleep a bit */
            trusty_nanosleep(0, 0, 100 * MSEC);
        }
        /* and close it */
        rc = close(chan);
        if (rc != NO_ERROR) {
            TLOGI("Failed (%d) to close chan %d\n", rc, chan);
        }
    }
}

static void closer2_handle_port(const uevent_t* ev) {
    struct closer2_state* st = get_srv_state(ev)->priv;

    if (handle_port_errors(ev))
        return;

    if (ev->event & IPC_HANDLE_POLL_READY) {
        /* new connection request, bump counter */
        st->conn_cnt++;
        if (st->conn_cnt & 1) {
            /* sleep a bit */
            trusty_nanosleep(0, 0, 100 * MSEC);
        }

        /*
         * then close the port without accepting any connections
         * and restart it again
         */
        restart_service(get_srv_state(ev));
    }
}

static void closer3_handle_port(const uevent_t* ev) {
    uuid_t peer_uuid;
    struct closer3_state* st = get_srv_state(ev)->priv;

    if (handle_port_errors(ev))
        return;

    if (ev->event & IPC_HANDLE_POLL_READY) {
        /* accept connection */
        int rc = accept(ev->handle, &peer_uuid);
        if (rc < 0) {
            TLOGI("accept failed (%d)\n", rc);
            return;
        }
        /* add it to connection pool */
        st->chans[st->chan_cnt++] = (handle_t)rc;

        /* attach datasink service handler just in case */
        set_cookie((handle_t)rc, &_datasink_chan_handler);

        /* when max number of connection reached */
        if (st->chan_cnt == countof(st->chans)) {
            /* wait a bit */
            trusty_nanosleep(0, 0, 100 * MSEC);

            /* and close them all */
            for (unsigned int i = 0; i < st->chan_cnt; i++)
                close(st->chans[i]);
            st->chan_cnt = 0;
        }
        return;
    }
}

/****************************** datasync service **************************/

static int datasink_handle_msg(const uevent_t* ev) {
    int rc;
    ipc_msg_info_t inf;

    /* for all messages */
    for (;;) {
        /* get message */
        rc = get_msg(ev->handle, &inf);
        if (rc == ERR_NO_MSG)
            break; /* no new messages */

        if (rc != NO_ERROR) {
            TLOGI("failed (%d) to get_msg for chan (%d)\n", rc, ev->handle);
            return rc;
        }

        /* and retire it without actually reading  */
        rc = put_msg(ev->handle, inf.id);
        if (rc != NO_ERROR) {
            TLOGI("failed (%d) to putt_msg for chan (%d)\n", rc, ev->handle);
            return rc;
        }
    }

    return NO_ERROR;
}

/*
 *  Datasink service channel handler
 */
static void datasink_handle_chan(const uevent_t* ev) {
    if ((ev->event & IPC_HANDLE_POLL_ERROR) ||
        (ev->event & IPC_HANDLE_POLL_SEND_UNBLOCKED)) {
        /* close it as it is in an error state */
        TLOGI("error event (0x%x) for chan (%d)\n", ev->event, ev->handle);
        close(ev->handle);
        return;
    }

    if (ev->event & IPC_HANDLE_POLL_MSG) {
        if (datasink_handle_msg(ev) != 0) {
            close(ev->handle);
            return;
        }
    }

    if (ev->event & IPC_HANDLE_POLL_HUP) {
        /* closed by peer */
        close(ev->handle);
        return;
    }
}

/*
 *  Datasink service port event handler
 */
static void datasink_handle_port(const uevent_t* ev) {
    uuid_t peer_uuid;

    if (handle_port_errors(ev))
        return;

    if (ev->event & IPC_HANDLE_POLL_READY) {
        /* incomming connection: accept it */
        int rc = accept(ev->handle, &peer_uuid);
        if (rc < 0) {
            TLOGI("failed (%d) to accept on port %d\n", rc, ev->handle);
            return;
        }

        handle_t chan = (handle_t)rc;
        rc = set_cookie(chan, &_datasink_chan_handler);
        if (rc) {
            TLOGI("failed (%d) to set_cookie on chan %d\n", rc, chan);
        }
    }
}

/******************************   echo service    **************************/

static int send_msg_wait(handle_t chan, ipc_msg_t* msg) {
    int rc;
    uevent_t ev;

    while (true) {
        rc = send_msg(chan, msg);

        if (rc != ERR_NOT_ENOUGH_BUFFER) {
            return rc;
        }

        while (true) {
            rc = wait(chan, &ev, INFINITE_TIME);
            if (rc < 0) {
                return rc;
            }

            if (ev.event & IPC_HANDLE_POLL_HUP) {
                /*
                 * It is possible that ev.event & IPC_HANDLE_POLL_MSG is also
                 * true which means the client sent a message and hung up on us.
                 * There isn't anything the echo server can do with those, so we
                 * simply log the occurrence.
                 */
                if (ev.event & IPC_HANDLE_POLL_MSG) {
                    TLOGW("Client sent a message and hung up;"
                          " message discarded.\n");
                }

                return ERR_CHANNEL_CLOSED;
            }

            if (ev.event & IPC_HANDLE_POLL_SEND_UNBLOCKED) {
                break;
            }

            /* if ev.event & IPC_HANDLE_POLL_MSG is true, continue looping */
        }
    }

    __UNREACHABLE;
}

static int echo_handle_msg(const uevent_t* ev) {
    int rc;
    ipc_msg_info_t msg_info;
    ipc_msg_t msg;
    msg.num_iov = 1;
    size_t msg_cnt = 0;
    echo_chan_state_t* st = containerof(ev->cookie, echo_chan_state_t, handler);

    /* get all messages */
    while (msg_cnt < st->msg_max_num) {
        rc = get_msg(ev->handle, &msg_info);
        if (rc == ERR_NO_MSG)
            break; /* no new messages */

        if (rc != NO_ERROR) {
            TLOGI("failed (%d) to get_msg for chan (%d)\n", rc, ev->handle);
            return rc;
        }

        /* save handle count */
        st->echo_msgs[msg_cnt].handle_cnt = msg_info.num_handles;
        /* prepare message structure for read */
        struct iovec iov = {
                .iov_base = (void*)st->echo_msgs[msg_cnt].msg_buf,
                .iov_len = MAX_PORT_BUF_SIZE,
        };
        msg.iov = &iov;
        msg.handles = st->echo_msgs[msg_cnt].handles;
        msg.num_handles = msg_info.num_handles;

        /* read msg content */
        rc = read_msg(ev->handle, msg_info.id, 0, &msg);
        if (rc < 0) {
            TLOGI("failed (%d) to read_msg for chan (%d)\n", rc, ev->handle);
            return rc;
        }

        /* update number of bytes received */
        st->echo_msgs[msg_cnt].msg_len = (size_t)rc;

        /* retire original message */
        rc = put_msg(ev->handle, msg_info.id);
        if (rc != NO_ERROR) {
            TLOGI("failed (%d) to put_msg for chan (%d)\n", rc, ev->handle);
            return rc;
        }

        msg_cnt++;
    }

    /* echo all messages received */
    for (unsigned int i = 0; i < msg_cnt; i++) {
        /* prepare message structure for send */
        struct iovec iov = {
                .iov_base = (void*)st->echo_msgs[i].msg_buf,
                .iov_len = st->echo_msgs[i].msg_len,
        };
        msg.iov = &iov;
        msg.handles = st->echo_msgs[i].handles;
        msg.num_handles = st->echo_msgs[i].handle_cnt;

        /* and send it back */
        rc = send_msg_wait(ev->handle, &msg);

        /* close all received handles */
        for (unsigned int j = 0; j < msg.num_handles; j++) {
            close(st->echo_msgs[i].handles[j]);
        }

        if (rc < 0) {
            TLOGI("failed (%d) to send_msg for chan (%d)\n", rc, ev->handle);
            return rc;
        }
    }
    return NO_ERROR;
}

/*
 * echo service channel handler
 */
static void echo_handle_chan(const uevent_t* ev) {
    if (ev->event & IPC_HANDLE_POLL_ERROR) {
        /* close it as it is in an error state */
        TLOGI("error event (0x%x) for chan (%d)\n", ev->event, ev->handle);
        goto close_it;
    }

    if (ev->event & (IPC_HANDLE_POLL_MSG | IPC_HANDLE_POLL_SEND_UNBLOCKED)) {
        if (echo_handle_msg(ev) != 0) {
            TLOGI("error event (0x%x) for chan (%d)\n", ev->event, ev->handle);
            goto close_it;
        }
    }

    if (ev->event & IPC_HANDLE_POLL_HUP) {
        goto close_it;
    }

    return;

close_it:
    free(ev->cookie);
    close(ev->handle);
}

/*
 *  echo service port event handler
 */
static void echo_handle_port(const uevent_t* ev) {
    uuid_t peer_uuid;
    struct echo_chan_state* chan_st;
    const struct tipc_srv* srv = get_srv_state(ev)->service;

    if (handle_port_errors(ev))
        return;

    if (ev->event & IPC_HANDLE_POLL_READY) {
        handle_t chan;

        /* incomming connection: accept it */
        int rc = accept(ev->handle, &peer_uuid);
        if (rc < 0) {
            TLOGI("failed (%d) to accept on port %d\n", rc, ev->handle);
            return;
        }
        chan = (handle_t)rc;

        chan_st = calloc(1, sizeof(struct echo_chan_state) +
                                    sizeof(struct echo_msg) * srv->msg_num);
        if (!chan_st) {
            TLOGI("failed (%d) to callocate state for chan %d\n", rc, chan);
            close(chan);
            return;
        }

        /* init state */
        chan_st->msg_max_num = srv->msg_num;
        chan_st->handler.proc = srv->chan_handler;
        chan_st->handler.priv = chan_st;

        /* attach it to handle */
        rc = set_cookie(chan, &chan_st->handler);
        if (rc) {
            TLOGI("failed (%d) to set_cookie on chan %d\n", rc, chan);
            free(chan_st);
            close(chan);
            return;
        }
    }
}

/***************************************************************************/

/*
 *  uuid service port event handler
 */
static void uuid_handle_port(const uevent_t* ev) {
    ipc_msg_t msg;
    struct iovec iov;
    uuid_t peer_uuid;

    if (handle_port_errors(ev))
        return;

    if (ev->event & IPC_HANDLE_POLL_READY) {
        handle_t chan;

        /* incomming connection: accept it */
        int rc = accept(ev->handle, &peer_uuid);
        if (rc < 0) {
            TLOGI("failed (%d) to accept on port %d\n", rc, ev->handle);
            return;
        }
        chan = (handle_t)rc;

        /* send interface uuid */
        iov.iov_base = &peer_uuid;
        iov.iov_len = sizeof(peer_uuid);
        msg.num_iov = 1;
        msg.iov = &iov;
        msg.num_handles = 0;
        msg.handles = NULL;
        rc = send_msg(chan, &msg);
        if (rc < 0) {
            TLOGI("failed (%d) to send_msg for chan (%d)\n", rc, chan);
        }

        /* and close channel */
        close(chan);
    }
}

/***************************************************************************/

/*
 *  Dispatch event
 */
static void dispatch_event(const uevent_t* ev) {
    assert(ev);

    if (ev->event == IPC_HANDLE_POLL_NONE) {
        /* not really an event, do nothing */
        TLOGI("got an empty event\n");
        return;
    }

    if (ev->handle == INVALID_IPC_HANDLE) {
        /* not a valid handle  */
        TLOGI("got an event (0x%x) with invalid handle (%d)", ev->event,
              ev->handle);
        return;
    }

    /* check if we have handler */
    struct tipc_event_handler* handler = ev->cookie;
    if (handler && handler->proc) {
        /* invoke it */
        handler->proc(ev);
        return;
    }

    /* no handler? close it */
    TLOGI("no handler for event (0x%x) with handle %d\n", ev->event,
          ev->handle);
    close(ev->handle);

    return;
}

/*
 *  Main entry point of service task
 */
int main(void) {
    int rc;
    uevent_t event;

    /* Initialize service */
    rc = init_services();
    if (rc != NO_ERROR) {
        TLOGI("Failed (%d) to init service", rc);
        kill_services();
        return -1;
    }

    /* handle events */
    while (!stopped) {
        event.handle = INVALID_IPC_HANDLE;
        event.event = 0;
        event.cookie = NULL;
        rc = wait_any(&event, INFINITE_TIME);
        if (rc < 0) {
            TLOGI("wait_any failed (%d)", rc);
            continue;
        }
        if (rc == NO_ERROR) { /* got an event */
            dispatch_event(&event);
        }
    }

    kill_services();
    return 0;
}