/*
 * Copyright (c) 2022-2024, NVIDIA CORPORATION.  All rights reserved.
 *
 * 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 "ipcsocket.h"
#include "tensorrt_llm/common/assert.h"
#include "tensorrt_llm/common/logger.h"
#include <errno.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#if ENABLE_MULTI_DEVICE
namespace tensorrt_llm::runtime::ub
{

static char const* ipcSocketResultStrings[static_cast<int>(ipcSocketNumResults)] = {
    "Success",
    "Unhandled CUDA error",
    "System error",
    "Internal error",
    "Invalid argument",
    "Invalid usage",
    "Remote error",
    "In progress",
};

char const* ipcSocketGetErrorString(ipcSocketResult_t res)
{
    return ipcSocketResultStrings[static_cast<int>(res)];
}

#define USE_ABSTRACT_SOCKET // Enable Linux abstract socket naming

#define IPC_SOCKNAME_STR "/tmp/ub-ipc-socket-%d-%lx"

/*
 * Create a Unix Domain Socket
 */
ipcSocketResult_t ipcSocketInit(IpcSocketHandle* handle, int rank, uint64_t hash, uint32_t volatile* abortFlag)
{
    int fd = -1;
    struct sockaddr_un cliaddr;
    char temp[IPC_SOCKNAME_LEN] = "";

    if (handle == NULL)
    {
        return ipcSocketInternalError;
    }

    handle->fd = -1;
    handle->socketName[0] = '\0';
    if ((fd = socket(AF_UNIX, SOCK_DGRAM, 0)) < 0)
    {
        TLLM_LOG_WARNING("UDS: Socket creation error");
        return ipcSocketSystemError;
    }

    bzero(&cliaddr, sizeof(cliaddr));
    cliaddr.sun_family = AF_UNIX;

    // Create unique name for the socket.
    size_t len = snprintf(temp, IPC_SOCKNAME_LEN, IPC_SOCKNAME_STR, rank, hash);
    if (len > (sizeof(cliaddr.sun_path) - 1))
    {
        errno = ENAMETOOLONG;
        TLLM_LOG_WARNING("UDS: Cannot bind provided name to socket. Name too large");
        return ipcSocketInternalError;
    }
    strncpy(cliaddr.sun_path, temp, len);
#ifdef USE_ABSTRACT_SOCKET
    cliaddr.sun_path[0] = '\0'; // Linux abstract socket trick
#else
    unlink(temp);
#endif
    if (bind(fd, (struct sockaddr*) &cliaddr, sizeof(cliaddr)) < 0)
    {
        TLLM_LOG_WARNING("UDS: Binding to socket %s failed", temp);
        close(fd);
        return ipcSocketSystemError;
    }

    handle->fd = fd;
    strcpy(handle->socketName, temp); // NOLINT(*)

    handle->abortFlag = abortFlag;
    // Mark socket as non-blocking
    if (handle->abortFlag)
    {
        int flags = fcntl(fd, F_GETFL);
        fcntl(fd, F_SETFL, flags | O_NONBLOCK);
    }

    return ipcSocketSuccess;
}

ipcSocketResult_t ipcSocketGetFd(struct IpcSocketHandle* handle, int* fd)
{
    if (handle == NULL)
    {
        errno = EINVAL;
        TLLM_LOG_WARNING("ipcSocketSocketGetFd: pass NULL socket");
        return ipcSocketInvalidArgument;
    }
    if (fd)
        *fd = handle->fd;
    return ipcSocketSuccess;
}

ipcSocketResult_t ipcSocketClose(IpcSocketHandle* handle)
{
    if (handle == NULL)
    {
        return ipcSocketInternalError;
    }
    if (handle->fd <= 0)
    {
        return ipcSocketSuccess;
    }
#ifndef USE_ABSTRACT_SOCKET
    if (handle->socketName[0] != '\0')
    {
        unlink(handle->socketName);
    }
#endif
    close(handle->fd);

    return ipcSocketSuccess;
}

ipcSocketResult_t ipcSocketRecvMsg(IpcSocketHandle* handle, void* hdr, int hdrLen, int* recvFd)
{
    struct msghdr msg = {0, 0, 0, 0, 0, 0, 0};
    struct iovec iov[1];

    // Union to guarantee alignment requirements for control array
    union
    {
        struct cmsghdr cm;
        char control[CMSG_SPACE(sizeof(int))];
    } control_un;

    struct cmsghdr* cmptr;
    char dummy_buffer[1];
    int ret;

    msg.msg_control = control_un.control;
    msg.msg_controllen = sizeof(control_un.control);

    if (hdr == NULL)
    {
        iov[0].iov_base = reinterpret_cast<void*>(dummy_buffer);
        iov[0].iov_len = sizeof(dummy_buffer);
    }
    else
    {
        iov[0].iov_base = hdr;
        iov[0].iov_len = hdrLen;
    }

    msg.msg_iov = iov;
    msg.msg_iovlen = 1;

    while ((ret = recvmsg(handle->fd, &msg, 0)) <= 0)
    {
        if (errno != EAGAIN && errno != EWOULDBLOCK && errno != EINTR)
        {
            TLLM_LOG_WARNING("UDS: Receiving data over socket failed");
            return ipcSocketSystemError;
        }
        if (handle->abortFlag && *handle->abortFlag)
            return ipcSocketInternalError;
    }

    if (recvFd != NULL)
    {
        if (((cmptr = CMSG_FIRSTHDR(&msg)) != NULL) && (cmptr->cmsg_len == CMSG_LEN(sizeof(int))))
        {
            if ((cmptr->cmsg_level != SOL_SOCKET) || (cmptr->cmsg_type != SCM_RIGHTS))
            {
                errno = EBADMSG;
                TLLM_LOG_WARNING("UDS: Receiving data over socket %s failed", handle->socketName);
                return ipcSocketSystemError;
            }

            memmove(recvFd, CMSG_DATA(cmptr), sizeof(*recvFd));
        }
        else
        {
            errno = ENOMSG;
            TLLM_LOG_WARNING("UDS: Receiving data over socket %s failed", handle->socketName);
            return ipcSocketSystemError;
        }
    }
    else
    {
        errno = EINVAL;
        TLLM_LOG_WARNING("UDS: File descriptor pointer cannot be NULL");
        return ipcSocketInvalidArgument;
    }

    return ipcSocketSuccess;
}

ipcSocketResult_t ipcSocketRecvFd(IpcSocketHandle* handle, int* recvFd)
{
    return ipcSocketRecvMsg(handle, NULL, 0, recvFd);
}

ipcSocketResult_t ipcSocketSendMsg(
    IpcSocketHandle* handle, void* hdr, int hdrLen, int const sendFd, int rank, uint64_t hash)
{
    struct msghdr msg = {0, 0, 0, 0, 0, 0, 0};
    struct iovec iov[1];
    char temp[IPC_SOCKNAME_LEN];

    union
    {
        struct cmsghdr cm;
        char control[CMSG_SPACE(sizeof(int))];
    } control_un;

    struct cmsghdr* cmptr;
    char dummy_buffer[1];
    struct sockaddr_un cliaddr;

    // Construct client address to send this shareable handle to
    bzero(&cliaddr, sizeof(cliaddr));
    cliaddr.sun_family = AF_UNIX;

    size_t len = snprintf(temp, IPC_SOCKNAME_LEN, IPC_SOCKNAME_STR, rank, hash);
    if (len > (sizeof(cliaddr.sun_path) - 1))
    {
        errno = ENAMETOOLONG;
        TLLM_LOG_WARNING("UDS: Cannot connect to provided name for socket. Name too large");
        return ipcSocketInternalError;
    }
    (void) strncpy(cliaddr.sun_path, temp, len);

#ifdef USE_ABSTRACT_SOCKET
    cliaddr.sun_path[0] = '\0'; // Linux abstract socket trick
#endif

    if (sendFd != -1)
    {
        msg.msg_control = control_un.control;
        msg.msg_controllen = sizeof(control_un.control);

        cmptr = CMSG_FIRSTHDR(&msg);
        cmptr->cmsg_len = CMSG_LEN(sizeof(int));
        cmptr->cmsg_level = SOL_SOCKET;
        cmptr->cmsg_type = SCM_RIGHTS;
        memmove(CMSG_DATA(cmptr), &sendFd, sizeof(sendFd));
    }

    msg.msg_name = reinterpret_cast<void*>(&cliaddr);
    msg.msg_namelen = sizeof(struct sockaddr_un);

    if (hdr == NULL)
    {
        iov[0].iov_base = reinterpret_cast<void*>(dummy_buffer);
        iov[0].iov_len = sizeof(dummy_buffer);
    }
    else
    {
        iov[0].iov_base = hdr;
        iov[0].iov_len = hdrLen;
    }
    msg.msg_iov = iov;
    msg.msg_iovlen = 1;
    msg.msg_flags = 0;

    ssize_t sendResult;
    while ((sendResult = sendmsg(handle->fd, &msg, 0)) < 0)
    {
        if (errno != EAGAIN && errno != EWOULDBLOCK && errno != EINTR)
        {
            TLLM_LOG_WARNING("UDS: Sending data over socket %s failed", temp);
            return ipcSocketSystemError;
        }
        if (handle->abortFlag && *handle->abortFlag)
            return ipcSocketInternalError;
    }

    return ipcSocketSuccess;
}

ipcSocketResult_t ipcSocketSendFd(IpcSocketHandle* handle, int const sendFd, int rank, uint64_t hash)
{
    return ipcSocketSendMsg(handle, NULL, 0, sendFd, rank, hash);
}
} // namespace tensorrt_llm::runtime::ub
#endif