/*

 * sftpserver.c - server based function for the sftp protocol

 *

 * This file is part of the SSH Library

 *

 * Copyright (c) 2005      by Aris Adamantiadis

 *

 * The SSH Library is free software; you can redistribute it and/or modify

 * it under the terms of the GNU Lesser General Public License as published by

 * the Free Software Foundation; either version 2.1 of the License, or (at your

 * option) any later version.

 *

 * The SSH Library is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY

 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public

 * License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public License

 * along with the SSH Library; see the file COPYING.  If not, write to

 * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,

 * MA 02111-1307, USA.

 */

#include "config.h"

#include <stdio.h>

#ifndef _WIN32

#include <netinet/in.h>

#include <arpa/inet.h>

#endif

#include "libssh/libssh.h"

#include "libssh/sftp.h"

#include "libssh/sftp_priv.h"

#include "libssh/ssh2.h"

#include "libssh/priv.h"

#include "libssh/buffer.h"

#include "libssh/misc.h"

#define SFTP_HANDLES 256

sftp_client_message sftp_get_client_message(sftp_session sftp) {

  ssh_session session = sftp->session;

  sftp_packet packet;

  sftp_client_message msg;

  ssh_buffer payload;

  int rc;

  msg = malloc(sizeof (struct sftp_client_message_struct));

  if (msg == NULL) {

    ssh_set_error_oom(session);

    return NULL;

  }

  ZERO_STRUCTP(msg);

  packet = sftp_packet_read(sftp);

  if (packet == NULL) {

    ssh_set_error_oom(session);

    sftp_client_message_free(msg);

    return NULL;

  }

  payload = packet->payload;

  msg->type = packet->type;

  msg->sftp = sftp;

  /* take a copy of the whole packet */

  msg->complete_message = ssh_buffer_new();

  ssh_buffer_add_data(msg->complete_message,

                      ssh_buffer_get(payload),

                      ssh_buffer_get_len(payload));

  ssh_buffer_get_u32(payload, &msg->id);

  switch(msg->type) {

    case SSH_FXP_CLOSE:

    case SSH_FXP_READDIR:

      msg->handle = ssh_buffer_get_ssh_string(payload);

      if (msg->handle == NULL) {

        ssh_set_error_oom(session);

        sftp_client_message_free(msg);

        return NULL;

      }

      break;

    case SSH_FXP_READ:

      rc = ssh_buffer_unpack(payload,

                             "Sqd",

                             &msg->handle,

                             &msg->offset,

                             &msg->len);

      if (rc != SSH_OK) {

        ssh_set_error_oom(session);

        sftp_client_message_free(msg);

        return NULL;

      }

      break;

    case SSH_FXP_WRITE:

      rc = ssh_buffer_unpack(payload,

                             "SqS",

                             &msg->handle,

                             &msg->offset,

                             &msg->data);

      if (rc != SSH_OK) {

        ssh_set_error_oom(session);

        sftp_client_message_free(msg);

        return NULL;

      }

      break;

    case SSH_FXP_REMOVE:

    case SSH_FXP_RMDIR:

    case SSH_FXP_OPENDIR:

    case SSH_FXP_READLINK:

    case SSH_FXP_REALPATH:

      rc = ssh_buffer_unpack(payload,

                             "s",

                             &msg->filename);

      if (rc != SSH_OK) {

        ssh_set_error_oom(session);

        sftp_client_message_free(msg);

        return NULL;

      }

      break;

    case SSH_FXP_RENAME:

    case SSH_FXP_SYMLINK:

      rc = ssh_buffer_unpack(payload,

                             "sS",

                             &msg->filename,

                             &msg->data);

      if (rc != SSH_OK) {

        ssh_set_error_oom(session);

        sftp_client_message_free(msg);

        return NULL;

      }

      break;

    case SSH_FXP_MKDIR:

    case SSH_FXP_SETSTAT:

      rc = ssh_buffer_unpack(payload,

                             "s",

                             &msg->filename);

      if (rc != SSH_OK) {

        ssh_set_error_oom(session);

        sftp_client_message_free(msg);

        return NULL;

      }

      msg->attr = sftp_parse_attr(sftp, payload, 0);

      if (msg->attr == NULL) {

        ssh_set_error_oom(session);

        sftp_client_message_free(msg);

        return NULL;

      }

      break;

    case SSH_FXP_FSETSTAT:

      msg->handle = ssh_buffer_get_ssh_string(payload);

      if (msg->handle == NULL) {

        ssh_set_error_oom(session);

        sftp_client_message_free(msg);

        return NULL;

      }

      msg->attr = sftp_parse_attr(sftp, payload, 0);

      if (msg->attr == NULL) {

        ssh_set_error_oom(session);

        sftp_client_message_free(msg);

        return NULL;

      }

      break;

    case SSH_FXP_LSTAT:

    case SSH_FXP_STAT:

      rc = ssh_buffer_unpack(payload,

                             "s",

                             &msg->filename);

      if (rc != SSH_OK) {

        ssh_set_error_oom(session);

        sftp_client_message_free(msg);

        return NULL;

      }

      if(sftp->version > 3) {

        ssh_buffer_unpack(payload, "d", &msg->flags);

      }

      break;

    case SSH_FXP_OPEN:

      rc = ssh_buffer_unpack(payload,

                             "sd",

                             &msg->filename,

                             &msg->flags);

      if (rc != SSH_OK) {

        ssh_set_error_oom(session);

        sftp_client_message_free(msg);

        return NULL;

      }

      msg->attr = sftp_parse_attr(sftp, payload, 0);

      if (msg->attr == NULL) {

        ssh_set_error_oom(session);

        sftp_client_message_free(msg);

        return NULL;

      }

      break;

    case SSH_FXP_FSTAT:

      rc = ssh_buffer_unpack(payload,

                             "S",

                             &msg->handle);

      if (rc != SSH_OK) {

        ssh_set_error_oom(session);

        sftp_client_message_free(msg);

        return NULL;

      }

      break;

    case SSH_FXP_EXTENDED:

      rc = ssh_buffer_unpack(payload,

                             "s",

                             &msg->submessage);

      if (rc != SSH_OK) {

        ssh_set_error_oom(session);

        sftp_client_message_free(msg);

        return NULL;

      }

      if (strcmp(msg->submessage, "hardlink@openssh.com") == 0 ||

          strcmp(msg->submessage, "posix-rename@openssh.com") == 0) {

        rc = ssh_buffer_unpack(payload,

                               "sS",

                               &msg->filename,

                               &msg->data);

        if (rc != SSH_OK) {

          ssh_set_error_oom(session);

          sftp_client_message_free(msg);

          return NULL;

        }

      }

      break;

    default:

      ssh_set_error(sftp->session, SSH_FATAL,

                    "Received unhandled sftp message %d", msg->type);

      sftp_client_message_free(msg);

      return NULL;

  }

  return msg;

}

/* Send an sftp client message. Can be used in cas of proxying */

int sftp_send_client_message(sftp_session sftp, sftp_client_message msg){

	return sftp_packet_write(sftp, msg->type, msg->complete_message);

}

uint8_t sftp_client_message_get_type(sftp_client_message msg){

	return msg->type;

}

const char *sftp_client_message_get_filename(sftp_client_message msg){

	return msg->filename;

}

void sftp_client_message_set_filename(sftp_client_message msg, const char *newname){

	free(msg->filename);

	msg->filename = strdup(newname);

}

const char *sftp_client_message_get_data(sftp_client_message msg){

	if (msg->str_data == NULL)

		msg->str_data = ssh_string_to_char(msg->data);

	return msg->str_data;

}

uint32_t sftp_client_message_get_flags(sftp_client_message msg){

	return msg->flags;

}

const char *sftp_client_message_get_submessage(sftp_client_message msg){

        return msg->submessage;

}

void sftp_client_message_free(sftp_client_message msg) {

  if (msg == NULL) {

    return;

  }

  SAFE_FREE(msg->filename);

  SAFE_FREE(msg->submessage);

  SSH_STRING_FREE(msg->data);

  SSH_STRING_FREE(msg->handle);

  sftp_attributes_free(msg->attr);

  SSH_BUFFER_FREE(msg->complete_message);

  SAFE_FREE(msg->str_data);

  ZERO_STRUCTP(msg);

  SAFE_FREE(msg);

}

int sftp_reply_name(sftp_client_message msg, const char *name,

    sftp_attributes attr) {

  ssh_buffer out;

  ssh_string file;

  out = ssh_buffer_new();

  if (out == NULL) {

    return -1;

  }

  file = ssh_string_from_char(name);

  if (file == NULL) {

    SSH_BUFFER_FREE(out);

    return -1;

  }

  if (ssh_buffer_add_u32(out, msg->id) < 0 ||

      ssh_buffer_add_u32(out, htonl(1)) < 0 ||

      ssh_buffer_add_ssh_string(out, file) < 0 ||

      ssh_buffer_add_ssh_string(out, file) < 0 || /* The protocol is broken here between 3 & 4 */

      buffer_add_attributes(out, attr) < 0 ||

      sftp_packet_write(msg->sftp, SSH_FXP_NAME, out) < 0) {

    SSH_BUFFER_FREE(out);

    SSH_STRING_FREE(file);

    return -1;

  }

  SSH_BUFFER_FREE(out);

  SSH_STRING_FREE(file);

  return 0;

}

int sftp_reply_handle(sftp_client_message msg, ssh_string handle){

  ssh_buffer out;

  out = ssh_buffer_new();

  if (out == NULL) {

    return -1;

  }

  if (ssh_buffer_add_u32(out, msg->id) < 0 ||

      ssh_buffer_add_ssh_string(out, handle) < 0 ||

      sftp_packet_write(msg->sftp, SSH_FXP_HANDLE, out) < 0) {

    SSH_BUFFER_FREE(out);

    return -1;

  }

  SSH_BUFFER_FREE(out);

  return 0;

}

int sftp_reply_attr(sftp_client_message msg, sftp_attributes attr) {

  ssh_buffer out;

  out = ssh_buffer_new();

  if (out == NULL) {

    return -1;

  }

  if (ssh_buffer_add_u32(out, msg->id) < 0 ||

      buffer_add_attributes(out, attr) < 0 ||

      sftp_packet_write(msg->sftp, SSH_FXP_ATTRS, out) < 0) {

    SSH_BUFFER_FREE(out);

    return -1;

  }

  SSH_BUFFER_FREE(out);

  return 0;

}

int sftp_reply_names_add(sftp_client_message msg, const char *file,

    const char *longname, sftp_attributes attr) {

  ssh_string name;

  name = ssh_string_from_char(file);

  if (name == NULL) {

    return -1;

  }

  if (msg->attrbuf == NULL) {

    msg->attrbuf = ssh_buffer_new();

    if (msg->attrbuf == NULL) {

      SSH_STRING_FREE(name);

      return -1;

    }

  }

  if (ssh_buffer_add_ssh_string(msg->attrbuf, name) < 0) {

    SSH_STRING_FREE(name);

    return -1;

  }

  SSH_STRING_FREE(name);

  name = ssh_string_from_char(longname);

  if (name == NULL) {

    return -1;

  }

  if (ssh_buffer_add_ssh_string(msg->attrbuf,name) < 0 ||

      buffer_add_attributes(msg->attrbuf,attr) < 0) {

    SSH_STRING_FREE(name);

    return -1;

  }

  SSH_STRING_FREE(name);

  msg->attr_num++;

  return 0;

}

int sftp_reply_names(sftp_client_message msg) {

  ssh_buffer out;

  out = ssh_buffer_new();

  if (out == NULL) {

    SSH_BUFFER_FREE(msg->attrbuf);

    return -1;

  }

  if (ssh_buffer_add_u32(out, msg->id) < 0 ||

      ssh_buffer_add_u32(out, htonl(msg->attr_num)) < 0 ||

      ssh_buffer_add_data(out, ssh_buffer_get(msg->attrbuf),

        ssh_buffer_get_len(msg->attrbuf)) < 0 ||

      sftp_packet_write(msg->sftp, SSH_FXP_NAME, out) < 0) {

    SSH_BUFFER_FREE(out);

    SSH_BUFFER_FREE(msg->attrbuf);

    return -1;

  }

  SSH_BUFFER_FREE(out);

  SSH_BUFFER_FREE(msg->attrbuf);

  msg->attr_num = 0;

  msg->attrbuf = NULL;

  return 0;

}

int sftp_reply_status(sftp_client_message msg, uint32_t status,

    const char *message) {

  ssh_buffer out;

  ssh_string s;

  out = ssh_buffer_new();

  if (out == NULL) {

    return -1;

  }

  s = ssh_string_from_char(message ? message : "");

  if (s == NULL) {

    SSH_BUFFER_FREE(out);

    return -1;

  }

  if (ssh_buffer_add_u32(out, msg->id) < 0 ||

      ssh_buffer_add_u32(out, htonl(status)) < 0 ||

      ssh_buffer_add_ssh_string(out, s) < 0 ||

      ssh_buffer_add_u32(out, 0) < 0 || /* language string */

      sftp_packet_write(msg->sftp, SSH_FXP_STATUS, out) < 0) {

    SSH_BUFFER_FREE(out);

    SSH_STRING_FREE(s);

    return -1;

  }

  SSH_BUFFER_FREE(out);

  SSH_STRING_FREE(s);

  return 0;

}

int sftp_reply_data(sftp_client_message msg, const void *data, int len) {

  ssh_buffer out;

  out = ssh_buffer_new();

  if (out == NULL) {

    return -1;

  }

  if (ssh_buffer_add_u32(out, msg->id) < 0 ||

      ssh_buffer_add_u32(out, ntohl(len)) < 0 ||

      ssh_buffer_add_data(out, data, len) < 0 ||

      sftp_packet_write(msg->sftp, SSH_FXP_DATA, out) < 0) {

    SSH_BUFFER_FREE(out);

    return -1;

  }

  SSH_BUFFER_FREE(out);

  return 0;

}

/*

 * This function will return you a new handle to give the client.

 * the function accepts an info that can be retrieved later with

 * the handle. Care is given that a corrupted handle won't give a

 * valid info (or worse).

 */

ssh_string sftp_handle_alloc(sftp_session sftp, void *info) {

  ssh_string ret;

  uint32_t val;

  uint32_t i;

  if (sftp->handles == NULL) {

    sftp->handles = calloc(SFTP_HANDLES, sizeof(void *));

    if (sftp->handles == NULL) {

      return NULL;

    }

  }

  for (i = 0; i < SFTP_HANDLES; i++) {

    if (sftp->handles[i] == NULL) {

      break;

    }

  }

  if (i == SFTP_HANDLES) {

    return NULL; /* no handle available */

  }

  val = i;

  ret = ssh_string_new(4);

  if (ret == NULL) {

    return NULL;

  }

  memcpy(ssh_string_data(ret), &val, sizeof(uint32_t));

  sftp->handles[i] = info;

  return ret;

}

void *sftp_handle(sftp_session sftp, ssh_string handle){

  uint32_t val;

  if (sftp->handles == NULL) {

    return NULL;

  }

  if (ssh_string_len(handle) != sizeof(uint32_t)) {

    return NULL;

  }

  memcpy(&val, ssh_string_data(handle), sizeof(uint32_t));

  if (val > SFTP_HANDLES) {

    return NULL;

  }

  return sftp->handles[val];

}

void sftp_handle_remove(sftp_session sftp, void *handle) {

  int i;

  for (i = 0; i < SFTP_HANDLES; i++) {

    if (sftp->handles[i] == handle) {

      sftp->handles[i] = NULL;

      break;

    }

  }

}