/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

#include "uv.h"
#include "internal.h"

#include <assert.h>
#include <errno.h>
#include <string.h>
#include <sys/un.h>
#include <unistd.h>
#include <stdlib.h>


int uv_pipe_init(uv_loop_t* loop, uv_pipe_t* handle, int ipc) {
  uv__stream_init(loop, (uv_stream_t*)handle, UV_NAMED_PIPE);
  handle->shutdown_req = NULL;
  handle->connect_req = NULL;
  handle->pipe_fname = NULL;
  handle->ipc = ipc;
  return 0;
}


int uv_pipe_bind(uv_pipe_t* handle, const char* name) {
  struct sockaddr_un saddr;
  const char* pipe_fname = NULL;
  int sockfd = -1;
  int err;

  /* Already bound? */
  if (uv__stream_fd(handle) >= 0)
    return -EINVAL;

  /* Make a copy of the file name, it outlives this function's scope. */
  pipe_fname = uv__strdup(name);
  if (pipe_fname == NULL)
    return -ENOMEM;

  /* We've got a copy, don't touch the original any more. */
  name = NULL;

  err = uv__socket(AF_UNIX, SOCK_STREAM, 0);
  if (err < 0)
    goto err_socket;
  sockfd = err;

  memset(&saddr, 0, sizeof saddr);
  strncpy(saddr.sun_path, pipe_fname, sizeof(saddr.sun_path) - 1);
  saddr.sun_path[sizeof(saddr.sun_path) - 1] = '\0';
  saddr.sun_family = AF_UNIX;

  if (bind(sockfd, (struct sockaddr*)&saddr, sizeof saddr)) {
    err = -errno;
    /* Convert ENOENT to EACCES for compatibility with Windows. */
    if (err == -ENOENT)
      err = -EACCES;
    goto err_bind;
  }

  /* Success. */
  handle->flags |= UV_HANDLE_BOUND;
  handle->pipe_fname = pipe_fname; /* Is a strdup'ed copy. */
  handle->io_watcher.fd = sockfd;
  return 0;

err_bind:
  uv__close(sockfd);

err_socket:
  uv__free((void*)pipe_fname);
  return err;
}


int uv_pipe_listen(uv_pipe_t* handle, int backlog, uv_connection_cb cb) {
  if (uv__stream_fd(handle) == -1)
    return -EINVAL;

#if defined(__MVS__)
  /* On zOS, backlog=0 has undefined behaviour */
  if (backlog == 0)
    backlog = 1;
  else if (backlog < 0)
    backlog = SOMAXCONN;
#endif

  if (listen(uv__stream_fd(handle), backlog))
    return -errno;

  handle->connection_cb = cb;
  handle->io_watcher.cb = uv__server_io;
  uv__io_start(handle->loop, &handle->io_watcher, POLLIN);
  return 0;
}


void uv__pipe_close(uv_pipe_t* handle) {
  if (handle->pipe_fname) {
    /*
     * Unlink the file system entity before closing the file descriptor.
     * Doing it the other way around introduces a race where our process
     * unlinks a socket with the same name that's just been created by
     * another thread or process.
     */
    unlink(handle->pipe_fname);
    uv__free((void*)handle->pipe_fname);
    handle->pipe_fname = NULL;
  }

  uv__stream_close((uv_stream_t*)handle);
}


int uv_pipe_open(uv_pipe_t* handle, uv_file fd) {
  int err;

  err = uv__nonblock(fd, 1);
  if (err)
    return err;

#if defined(__APPLE__)
  err = uv__stream_try_select((uv_stream_t*) handle, &fd);
  if (err)
    return err;
#endif /* defined(__APPLE__) */

  return uv__stream_open((uv_stream_t*)handle,
                         fd,
                         UV_STREAM_READABLE | UV_STREAM_WRITABLE);
}


void uv_pipe_connect(uv_connect_t* req,
                    uv_pipe_t* handle,
                    const char* name,
                    uv_connect_cb cb) {
  struct sockaddr_un saddr;
  int new_sock;
  int err;
  int r;

  new_sock = (uv__stream_fd(handle) == -1);

  if (new_sock) {
    err = uv__socket(AF_UNIX, SOCK_STREAM, 0);
    if (err < 0)
      goto out;
    handle->io_watcher.fd = err;
  }

  memset(&saddr, 0, sizeof saddr);
  strncpy(saddr.sun_path, name, sizeof(saddr.sun_path) - 1);
  saddr.sun_path[sizeof(saddr.sun_path) - 1] = '\0';
  saddr.sun_family = AF_UNIX;

  do {
    r = connect(uv__stream_fd(handle),
                (struct sockaddr*)&saddr, sizeof saddr);
  }
  while (r == -1 && errno == EINTR);

  if (r == -1 && errno != EINPROGRESS) {
    err = -errno;
    goto out;
  }

  err = 0;
  if (new_sock) {
    err = uv__stream_open((uv_stream_t*)handle,
                          uv__stream_fd(handle),
                          UV_STREAM_READABLE | UV_STREAM_WRITABLE);
  }

  if (err == 0)
    uv__io_start(handle->loop, &handle->io_watcher, POLLIN | POLLOUT);

out:
  handle->delayed_error = err;
  handle->connect_req = req;

  uv__req_init(handle->loop, req, UV_CONNECT);
  req->handle = (uv_stream_t*)handle;
  req->cb = cb;
  QUEUE_INIT(&req->queue);

  /* Force callback to run on next tick in case of error. */
  if (err)
    uv__io_feed(handle->loop, &handle->io_watcher);

}


typedef int (*uv__peersockfunc)(int, struct sockaddr*, socklen_t*);


static int uv__pipe_getsockpeername(const uv_pipe_t* handle,
                                    uv__peersockfunc func,
                                    char* buffer,
                                    size_t* size) {
  struct sockaddr_un sa;
  socklen_t addrlen;
  int err;

  addrlen = sizeof(sa);
  memset(&sa, 0, addrlen);
  err = func(uv__stream_fd(handle), (struct sockaddr*) &sa, &addrlen);
  if (err < 0) {
    *size = 0;
    return -errno;
  }

#if defined(__linux__)
  if (sa.sun_path[0] == 0)
    /* Linux abstract namespace */
    addrlen -= offsetof(struct sockaddr_un, sun_path);
  else
#endif
    addrlen = strlen(sa.sun_path);


  if (addrlen >= *size) {
    *size = addrlen + 1;
    return UV_ENOBUFS;
  }

  memcpy(buffer, sa.sun_path, addrlen);
  *size = addrlen;

  /* only null-terminate if it's not an abstract socket */
  if (buffer[0] != '\0')
    buffer[addrlen] = '\0';

  return 0;
}


int uv_pipe_getsockname(const uv_pipe_t* handle, char* buffer, size_t* size) {
  return uv__pipe_getsockpeername(handle, getsockname, buffer, size);
}


int uv_pipe_getpeername(const uv_pipe_t* handle, char* buffer, size_t* size) {
  return uv__pipe_getsockpeername(handle, getpeername, buffer, size);
}


void uv_pipe_pending_instances(uv_pipe_t* handle, int count) {
}


int uv_pipe_pending_count(uv_pipe_t* handle) {
  uv__stream_queued_fds_t* queued_fds;

  if (!handle->ipc)
    return 0;

  if (handle->accepted_fd == -1)
    return 0;

  if (handle->queued_fds == NULL)
    return 1;

  queued_fds = handle->queued_fds;
  return queued_fds->offset + 1;
}


uv_handle_type uv_pipe_pending_type(uv_pipe_t* handle) {
  if (!handle->ipc)
    return UV_UNKNOWN_HANDLE;

  if (handle->accepted_fd == -1)
    return UV_UNKNOWN_HANDLE;
  else
    return uv__handle_type(handle->accepted_fd);
}
