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

 *                                  _   _ ____  _

 *  Project                     ___| | | |  _ \| |

 *                             / __| | | | |_) | |

 *                            | (__| |_| |  _ <| |___

 *                             \___|\___/|_| \_\_____|

 *

 * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.

 *

 * This software is licensed as described in the file COPYING, which

 * you should have received as part of this distribution. The terms

 * are also available at https://curl.se/docs/copyright.html.

 *

 * You may opt to use, copy, modify, merge, publish, distribute and/or sell

 * copies of the Software, and permit persons to whom the Software is

 * furnished to do so, under the terms of the COPYING file.

 *

 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY

 * KIND, either express or implied.

 *

 * SPDX-License-Identifier: curl

 *

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

#include "curl_setup.h"

#ifndef CURL_DISABLE_FILE

#ifdef HAVE_NETINET_IN_H

#include <netinet/in.h>

#endif

#ifdef HAVE_NETDB_H

#include <netdb.h>

#endif

#ifdef HAVE_ARPA_INET_H

#include <arpa/inet.h>

#endif

#ifdef HAVE_NET_IF_H

#include <net/if.h>

#endif

#ifdef HAVE_SYS_IOCTL_H

#include <sys/ioctl.h>

#endif

#ifdef HAVE_SYS_PARAM_H

#include <sys/param.h>

#endif

#ifdef HAVE_SYS_TYPES_H

#include <sys/types.h>

#endif

#ifdef HAVE_DIRENT_H

#include <dirent.h>

#endif

#include "urldata.h"

#include "progress.h"

#include "sendf.h"

#include "curl_trc.h"

#include "escape.h"

#include "file.h"

#include "multiif.h"

#include "transfer.h"

#include "url.h"

#include "parsedate.h" /* for the week day and month names */

#include "curlx/fopen.h"

#include "curl_range.h"

#if defined(_WIN32) || defined(MSDOS)

#define DOS_FILESYSTEM 1

#elif defined(__amigaos4__)

#define AMIGA_FILESYSTEM 1

#endif

/* meta key for storing protocol meta at easy handle */

#define CURL_META_FILE_EASY   "meta:proto:file:easy"

struct FILEPROTO {

  char *path; /* the path we operate on */

  char *freepath; /* pointer to the allocated block we must free, this might

                     differ from the 'path' pointer */

  int fd;     /* open file descriptor to read from! */

};

/*

 * Forward declarations.

 */

static CURLcode file_do(struct Curl_easy *data, bool *done);

static CURLcode file_done(struct Curl_easy *data,

                          CURLcode status, bool premature);

static CURLcode file_connect(struct Curl_easy *data, bool *done);

static CURLcode file_disconnect(struct Curl_easy *data,

                                struct connectdata *conn,

                                bool dead_connection);

static CURLcode file_setup_connection(struct Curl_easy *data,

                                      struct connectdata *conn);

/*

 * FILE scheme handler.

 */

const struct Curl_handler Curl_handler_file = {

  "file",                               /* scheme */

  file_setup_connection,                /* setup_connection */

  file_do,                              /* do_it */

  file_done,                            /* done */

  ZERO_NULL,                            /* do_more */

  file_connect,                         /* connect_it */

  ZERO_NULL,                            /* connecting */

  ZERO_NULL,                            /* doing */

  ZERO_NULL,                            /* proto_pollset */

  ZERO_NULL,                            /* doing_pollset */

  ZERO_NULL,                            /* domore_pollset */

  ZERO_NULL,                            /* perform_pollset */

  file_disconnect,                      /* disconnect */

  ZERO_NULL,                            /* write_resp */

  ZERO_NULL,                            /* write_resp_hd */

  ZERO_NULL,                            /* connection_check */

  ZERO_NULL,                            /* attach connection */

  ZERO_NULL,                            /* follow */

  0,                                    /* defport */

  CURLPROTO_FILE,                       /* protocol */

  CURLPROTO_FILE,                       /* family */

  PROTOPT_NONETWORK | PROTOPT_NOURLQUERY /* flags */

};

static void file_cleanup(struct FILEPROTO *file)

{

  Curl_safefree(file->freepath);

  file->path = NULL;

  if(file->fd != -1) {

    close(file->fd);

    file->fd = -1;

  }

}

static void file_easy_dtor(void *key, size_t klen, void *entry)

{

  struct FILEPROTO *file = entry;

  (void)key;

  (void)klen;

  file_cleanup(file);

  curlx_free(file);

}

static CURLcode file_setup_connection(struct Curl_easy *data,

                                      struct connectdata *conn)

{

  struct FILEPROTO *filep;

  (void)conn;

  /* allocate the FILE specific struct */

  filep = curlx_calloc(1, sizeof(*filep));

  if(!filep ||

     Curl_meta_set(data, CURL_META_FILE_EASY, filep, file_easy_dtor))

    return CURLE_OUT_OF_MEMORY;

  return CURLE_OK;

}

/*

 * file_connect() gets called from Curl_protocol_connect() to allow us to

 * do protocol-specific actions at connect-time. We emulate a

 * connect-then-transfer protocol and "connect" to the file here

 */

static CURLcode file_connect(struct Curl_easy *data, bool *done)

{

  char *real_path;

  struct FILEPROTO *file = Curl_meta_get(data, CURL_META_FILE_EASY);

  int fd;

#ifdef DOS_FILESYSTEM

  size_t i;

  char *actual_path;

#endif

  size_t real_path_len;

  CURLcode result;

  if(!file)

    return CURLE_FAILED_INIT;

  if(file->path) {

    /* already connected.

     * the handler->connect_it() is normally only called once, but

     * FILE does a special check on setting up the connection which

     * calls this explicitly. */

    *done = TRUE;

    return CURLE_OK;

  }

  result = Curl_urldecode(data->state.up.path, 0, &real_path,

                          &real_path_len, REJECT_ZERO);

  if(result)

    return result;

#ifdef DOS_FILESYSTEM

  /* If the first character is a slash, and there is

     something that looks like a drive at the beginning of

     the path, skip the slash. If we remove the initial

     slash in all cases, paths without drive letters end up

     relative to the current directory which is not how

     browsers work.

     Some browsers accept | instead of : as the drive letter

     separator, so we do too.

     On other platforms, we need the slash to indicate an

     absolute pathname. On Windows, absolute paths start

     with a drive letter.

  */

  actual_path = real_path;

  if((actual_path[0] == '/') &&

      actual_path[1] &&

     (actual_path[2] == ':' || actual_path[2] == '|')) {

    actual_path[2] = ':';

    actual_path++;

    real_path_len--;

  }

  /* change path separators from '/' to '\\' for DOS, Windows and OS/2 */

  for(i = 0; i < real_path_len; ++i)

    if(actual_path[i] == '/')

      actual_path[i] = '\\';

    else if(!actual_path[i]) { /* binary zero */

      Curl_safefree(real_path);

      return CURLE_URL_MALFORMAT;

    }

  fd = curlx_open(actual_path, O_RDONLY | CURL_O_BINARY);

  file->path = actual_path;

#else

  if(memchr(real_path, 0, real_path_len)) {

    /* binary zeroes indicate foul play */

    Curl_safefree(real_path);

    return CURLE_URL_MALFORMAT;

  }

  #ifdef AMIGA_FILESYSTEM

  /*

   * A leading slash in an AmigaDOS path denotes the parent

   * directory, and hence we block this as it is relative.

   * Absolute paths start with 'volumename:', so we check for

   * this first. Failing that, we treat the path as a real Unix

   * path, but only if the application was compiled with -lunix.

   */

  fd = -1;

  file->path = real_path;

  if(real_path[0] == '/') {

    extern int __unix_path_semantics;

    if(strchr(real_path + 1, ':')) {

      /* Amiga absolute path */

      fd = curlx_open(real_path + 1, O_RDONLY);

      file->path++;

    }

    else if(__unix_path_semantics) {

      /* -lunix fallback */

      fd = curlx_open(real_path, O_RDONLY);

    }

  }

  #else

  fd = curlx_open(real_path, O_RDONLY);

  file->path = real_path;

  #endif

#endif

  curlx_free(file->freepath);

  file->freepath = real_path; /* free this when done */

  file->fd = fd;

  if(!data->state.upload && (fd == -1)) {

    failf(data, "Could not open file %s", data->state.up.path);

    file_done(data, CURLE_FILE_COULDNT_READ_FILE, FALSE);

    return CURLE_FILE_COULDNT_READ_FILE;

  }

  *done = TRUE;

  return CURLE_OK;

}

static CURLcode file_done(struct Curl_easy *data,

                          CURLcode status, bool premature)

{

  struct FILEPROTO *file = Curl_meta_get(data, CURL_META_FILE_EASY);

  (void)status;

  (void)premature;

  if(file)

    file_cleanup(file);

  return CURLE_OK;

}

static CURLcode file_disconnect(struct Curl_easy *data,

                                struct connectdata *conn,

                                bool dead_connection)

{

  (void)dead_connection;

  (void)conn;

  return file_done(data, CURLE_OK, FALSE);

}

#ifdef DOS_FILESYSTEM

#define DIRSEP '\\'

#else

#define DIRSEP '/'

#endif

static CURLcode file_upload(struct Curl_easy *data,

                            struct FILEPROTO *file)

{

  const char *dir = strchr(file->path, DIRSEP);

  int fd;

  int mode;

  CURLcode result = CURLE_OK;

  char *xfer_ulbuf;

  size_t xfer_ulblen;

  struct_stat file_stat;

  const char *sendbuf;

  bool eos = FALSE;

  /*

   * Since FILE: does not do the full init, we need to provide some extra

   * assignments here.

   */

  if(!dir)

    return CURLE_FILE_COULDNT_READ_FILE; /* fix: better error code */

  if(!dir[1])

    return CURLE_FILE_COULDNT_READ_FILE; /* fix: better error code */

  mode = O_WRONLY | O_CREAT | CURL_O_BINARY;

  if(data->state.resume_from)

    mode |= O_APPEND;

  else

    mode |= O_TRUNC;

#ifdef _WIN32

  fd = curlx_open(file->path, mode,

                  data->set.new_file_perms & (_S_IREAD | _S_IWRITE));

#elif (defined(ANDROID) || defined(__ANDROID__)) && \

  (defined(__i386__) || defined(__arm__))

  fd = curlx_open(file->path, mode, (mode_t)data->set.new_file_perms);

#else

  fd = curlx_open(file->path, mode, data->set.new_file_perms);

#endif

  if(fd < 0) {

    failf(data, "cannot open %s for writing", file->path);

    return CURLE_WRITE_ERROR;

  }

  if(data->state.infilesize != -1)

    /* known size of data to "upload" */

    Curl_pgrsSetUploadSize(data, data->state.infilesize);

  /* treat the negative resume offset value as the case of "-" */

  if(data->state.resume_from < 0) {

    if(fstat(fd, &file_stat)) {

      close(fd);

      failf(data, "cannot get the size of %s", file->path);

      return CURLE_WRITE_ERROR;

    }

    data->state.resume_from = (curl_off_t)file_stat.st_size;

  }

  result = Curl_multi_xfer_ulbuf_borrow(data, &xfer_ulbuf, &xfer_ulblen);

  if(result)

    goto out;

  while(!result && !eos) {

    size_t nread, nwritten;

    ssize_t rv;

    size_t readcount;

    result = Curl_client_read(data, xfer_ulbuf, xfer_ulblen, &readcount, &eos);

    if(result)

      break;

    if(!readcount)

      break;

    nread = readcount;

    /* skip bytes before resume point */

    if(data->state.resume_from) {

      if((curl_off_t)nread <= data->state.resume_from) {

        data->state.resume_from -= nread;

        nread = 0;

        sendbuf = xfer_ulbuf;

      }

      else {

        sendbuf = xfer_ulbuf + data->state.resume_from;

        nread -= (size_t)data->state.resume_from;

        data->state.resume_from = 0;

      }

    }

    else

      sendbuf = xfer_ulbuf;

    /* write the data to the target */

    rv = write(fd, sendbuf, nread);

    if(!curlx_sztouz(rv, &nwritten) || (nwritten != nread)) {

      result = CURLE_SEND_ERROR;

      break;

    }

    Curl_pgrs_upload_inc(data, nwritten);

    result = Curl_pgrsCheck(data);

  }

  if(!result)

    result = Curl_pgrsUpdate(data);

out:

  close(fd);

  Curl_multi_xfer_ulbuf_release(data, xfer_ulbuf);

  return result;

}

/*

 * file_do() is the protocol-specific function for the do-phase, separated

 * from the connect-phase above. Other protocols merely setup the transfer in

 * the do-phase, to have it done in the main transfer loop but since some

 * platforms we support do not allow select()ing etc on file handles (as

 * opposed to sockets) we instead perform the whole do-operation in this

 * function.

 */

static CURLcode file_do(struct Curl_easy *data, bool *done)

{

  /* This implementation ignores the hostname in conformance with

     RFC 1738. Only local files (reachable via the standard file system)

     are supported. This means that files on remotely mounted directories

     (via NFS, Samba, NT sharing) can be accessed through a file:// URL

  */

  struct FILEPROTO *file = Curl_meta_get(data, CURL_META_FILE_EASY);

  CURLcode result = CURLE_OK;

  struct_stat statbuf; /* struct_stat instead of struct stat just to allow the

                          Windows version to have a different struct without

                          having to redefine the simple word 'stat' */

  curl_off_t expected_size = -1;

  bool size_known;

  bool fstated = FALSE;

  int fd;

  char *xfer_buf;

  size_t xfer_blen;

  *done = TRUE; /* unconditionally */

  if(!file)

    return CURLE_FAILED_INIT;

  if(data->state.upload)

    return file_upload(data, file);

  /* get the fd from the connection phase */

  fd = file->fd;

  /* VMS: This only works reliable for STREAMLF files */

  if(fstat(fd, &statbuf) != -1) {

    if(!S_ISDIR(statbuf.st_mode))

      expected_size = statbuf.st_size;

    /* and store the modification time */

    data->info.filetime = statbuf.st_mtime;

    fstated = TRUE;

  }

  if(fstated && !data->state.range && data->set.timecondition &&

     !Curl_meets_timecondition(data, data->info.filetime))

    return CURLE_OK;

  if(fstated) {

    time_t filetime;

    struct tm buffer;

    const struct tm *tm = &buffer;

    char header[80];

    int headerlen;

    static const char accept_ranges[] = { "Accept-ranges: bytes\r\n" };

    if(expected_size >= 0) {

      headerlen =

        curl_msnprintf(header, sizeof(header),

                       "Content-Length: %" FMT_OFF_T "\r\n", expected_size);

      result = Curl_client_write(data, CLIENTWRITE_HEADER, header, headerlen);

      if(result)

        return result;

      result = Curl_client_write(data, CLIENTWRITE_HEADER,

                                 accept_ranges, sizeof(accept_ranges) - 1);

      if(result != CURLE_OK)

        return result;

    }

    filetime = (time_t)statbuf.st_mtime;

    result = curlx_gmtime(filetime, &buffer);

    if(result)

      return result;

    /* format: "Tue, 15 Nov 1994 12:45:26 GMT" */

    headerlen =

      curl_msnprintf(header, sizeof(header),

                     "Last-Modified: %s, %02d %s %4d %02d:%02d:%02d GMT\r\n",

                     Curl_wkday[tm->tm_wday ? tm->tm_wday - 1 : 6],

                     tm->tm_mday,

                     Curl_month[tm->tm_mon],

                     tm->tm_year + 1900,

                     tm->tm_hour,

                     tm->tm_min,

                     tm->tm_sec);

    result = Curl_client_write(data, CLIENTWRITE_HEADER, header, headerlen);

    if(!result)

      /* end of headers */

      result = Curl_client_write(data, CLIENTWRITE_HEADER, "\r\n", 2);

    if(result)

      return result;

    /* set the file size to make it available post transfer */

    Curl_pgrsSetDownloadSize(data, expected_size);

    if(data->req.no_body)

      return CURLE_OK;

  }

  /* Check whether file range has been specified */

  result = Curl_range(data);

  if(result)

    return result;

  /* Adjust the start offset in case we want to get the N last bytes

   * of the stream if the filesize could be determined */

  if(data->state.resume_from < 0) {

    if(!fstated) {

      failf(data, "cannot get the size of file.");

      return CURLE_READ_ERROR;

    }

    data->state.resume_from += (curl_off_t)statbuf.st_size;

  }

  if(data->state.resume_from > 0) {

    /* We check explicitly if we have a start offset, because

     * expected_size may be -1 if we do not know how large the file is,

     * in which case we should not adjust it. */

    if(data->state.resume_from <= expected_size)

      expected_size -= data->state.resume_from;

    else {

      failf(data, "failed to resume file:// transfer");

      return CURLE_BAD_DOWNLOAD_RESUME;

    }

  }

  /* A high water mark has been specified so we obey... */

  if(data->req.maxdownload > 0)

    expected_size = data->req.maxdownload;

  if(!fstated || (expected_size <= 0))

    size_known = FALSE;

  else

    size_known = TRUE;

  /* The following is a shortcut implementation of file reading

     this is both more efficient than the former call to download() and

     it avoids problems with select() and recv() on file descriptors

     in Winsock */

  if(size_known)

    Curl_pgrsSetDownloadSize(data, expected_size);

  if(data->state.resume_from) {

    if(!S_ISDIR(statbuf.st_mode)) {

#ifdef __AMIGA__

      if(data->state.resume_from !=

         lseek(fd, (off_t)data->state.resume_from, SEEK_SET))

#else

      if(data->state.resume_from !=

         lseek(fd, data->state.resume_from, SEEK_SET))

#endif

        return CURLE_BAD_DOWNLOAD_RESUME;

    }

    else {

      return CURLE_BAD_DOWNLOAD_RESUME;

    }

  }

  result = Curl_multi_xfer_buf_borrow(data, &xfer_buf, &xfer_blen);

  if(result)

    goto out;

  if(!S_ISDIR(statbuf.st_mode)) {

    while(!result) {

      ssize_t nread;

      /* Do not fill a whole buffer if we want less than all data */

      size_t bytestoread;

      if(size_known) {

        bytestoread = (expected_size < (curl_off_t)(xfer_blen - 1)) ?

          curlx_sotouz(expected_size) : (xfer_blen - 1);

      }

      else

        bytestoread = xfer_blen - 1;

      nread = read(fd, xfer_buf, bytestoread);

      if(nread > 0)

        xfer_buf[nread] = 0;

      if(nread <= 0 || (size_known && (expected_size == 0)))

        break;

      if(size_known)

        expected_size -= nread;

      result = Curl_client_write(data, CLIENTWRITE_BODY, xfer_buf, nread);

      if(result)

        goto out;

      result = Curl_pgrsCheck(data);

      if(result)

        goto out;

    }

  }

  else {

#ifdef HAVE_OPENDIR

    DIR *dir = opendir(file->path);

    struct dirent *entry;

    if(!dir) {

      result = CURLE_READ_ERROR;

      goto out;

    }

    else {

      while((entry = readdir(dir))) {

        if(entry->d_name[0] != '.') {

          result = Curl_client_write(data, CLIENTWRITE_BODY,

                   entry->d_name, strlen(entry->d_name));

          if(result)

            break;

          result = Curl_client_write(data, CLIENTWRITE_BODY, "\n", 1);

          if(result)

            break;

        }

      }

      closedir(dir);

    }

#else

    failf(data, "Directory listing not yet implemented on this platform.");

    result = CURLE_READ_ERROR;

#endif

  }

  if(!result)

    result = Curl_pgrsUpdate(data);

out:

  Curl_multi_xfer_buf_release(data, xfer_buf);

  return result;

}

#endif