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b7018c17c75a5eb69c441fbe554395cbdede64ad
libssh/src/sftp_aio.c
Jakub Jelen b7018c17c7 Fix implicit type conversions and warnings on windows builds 
The visual studio windows builds spit dozens of lines of warnings
on these.

Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
2025-01-03 15:18:53 +01:00

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/*
* sftp_aio.c - Secure FTP functions for asynchronous i/o
*
* This file is part of the SSH Library
*
* Copyright (c) 2005-2008 by Aris Adamantiadis
* Copyright (c) 2008-2018 by Andreas Schneider <asn@cryptomilk.org>
* Copyright (c) 2023 by Eshan Kelkar <eshankelkar@galorithm.com>
*
* 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 "libssh/sftp.h"
#include "libssh/sftp_priv.h"
#include "libssh/buffer.h"
#include "libssh/session.h"
#ifdef WITH_SFTP
struct sftp_aio_struct {
sftp_file file;
uint32_t id;
size_t len;
};
static sftp_aio sftp_aio_new(void)
{
sftp_aio aio = NULL;
aio = calloc(1, sizeof(struct sftp_aio_struct));
return aio;
}
void sftp_aio_free(sftp_aio aio)
{
SAFE_FREE(aio);
}
ssize_t sftp_aio_begin_read(sftp_file file, size_t len, sftp_aio *aio)
{
sftp_session sftp = NULL;
ssh_buffer buffer = NULL;
sftp_aio aio_handle = NULL;
uint32_t id;
int rc;
if (file == NULL ||
file->sftp == NULL ||
file->sftp->session == NULL) {
return SSH_ERROR;
}
sftp = file->sftp;
if (len == 0) {
ssh_set_error(sftp->session, SSH_FATAL,
"Invalid argument, 0 passed as the number of "
"bytes to read");
sftp_set_error(sftp, SSH_FX_FAILURE);
return SSH_ERROR;
}
/* Apply a cap on the length a user is allowed to read */
if (len > sftp->limits->max_read_length) {
if (sftp->limits->max_read_length > SIZE_MAX) {
return SSH_ERROR;
}
len = (size_t)sftp->limits->max_read_length;
}
if (aio == NULL) {
ssh_set_error(sftp->session, SSH_FATAL,
"Invalid argument, NULL passed instead of a pointer to "
"a location to store an sftp aio handle");
sftp_set_error(sftp, SSH_FX_FAILURE);
return SSH_ERROR;
}
buffer = ssh_buffer_new();
if (buffer == NULL) {
ssh_set_error_oom(sftp->session);
sftp_set_error(sftp, SSH_FX_FAILURE);
return SSH_ERROR;
}
id = sftp_get_new_id(sftp);
rc = ssh_buffer_pack(buffer,
"dSqd",
id,
file->handle,
file->offset,
len);
if (rc != SSH_OK) {
ssh_set_error_oom(sftp->session);
sftp_set_error(sftp, SSH_FX_FAILURE);
SSH_BUFFER_FREE(buffer);
return SSH_ERROR;
}
aio_handle = sftp_aio_new();
if (aio_handle == NULL) {
ssh_set_error_oom(sftp->session);
sftp_set_error(sftp, SSH_FX_FAILURE);
SSH_BUFFER_FREE(buffer);
return SSH_ERROR;
}
aio_handle->file = file;
aio_handle->id = id;
aio_handle->len = len;
rc = sftp_packet_write(sftp, SSH_FXP_READ, buffer);
SSH_BUFFER_FREE(buffer);
if (rc == SSH_ERROR) {
SFTP_AIO_FREE(aio_handle);
return SSH_ERROR;
}
/* Assume we read len bytes from the file */
file->offset += len;
*aio = aio_handle;
return len;
}
ssize_t sftp_aio_wait_read(sftp_aio *aio,
void *buf,
size_t buf_size)
{
sftp_file file = NULL;
size_t bytes_requested;
sftp_session sftp = NULL;
sftp_message msg = NULL;
sftp_status_message status = NULL;
uint32_t string_len, host_len;
int rc, err;
/*
* This function releases the memory of the structure
* that (*aio) points to in all cases except when the
* return value is SSH_AGAIN.
*
* If the return value is SSH_AGAIN, the user should call this
* function again to get the response for the request corresponding
* to the structure that (*aio) points to, hence we don't release the
* structure's memory when SSH_AGAIN is returned.
*/
if (aio == NULL || *aio == NULL) {
return SSH_ERROR;
}
file = (*aio)->file;
bytes_requested = (*aio)->len;
if (file == NULL ||
file->sftp == NULL ||
file->sftp->session == NULL) {
SFTP_AIO_FREE(*aio);
return SSH_ERROR;
}
sftp = file->sftp;
if (bytes_requested == 0) {
/* should never happen */
ssh_set_error(sftp->session, SSH_FATAL,
"Invalid sftp aio, len for requested i/o is 0");
sftp_set_error(sftp, SSH_FX_FAILURE);
SFTP_AIO_FREE(*aio);
return SSH_ERROR;
}
if (buf == NULL) {
ssh_set_error(sftp->session, SSH_FATAL,
"Invalid argument, NULL passed "
"instead of a buffer's address");
sftp_set_error(sftp, SSH_FX_FAILURE);
SFTP_AIO_FREE(*aio);
return SSH_ERROR;
}
if (buf_size < bytes_requested) {
ssh_set_error(sftp->session, SSH_FATAL,
"Buffer size (%zu, passed by the caller) is "
"smaller than the number of bytes requested "
"to read (%zu, as per the supplied sftp aio)",
buf_size, bytes_requested);
sftp_set_error(sftp, SSH_FX_FAILURE);
SFTP_AIO_FREE(*aio);
return SSH_ERROR;
}
/* handle an existing request */
rc = sftp_recv_response_msg(sftp, (*aio)->id, !file->nonblocking, &msg);
if (rc == SSH_ERROR) {
SFTP_AIO_FREE(*aio);
return SSH_ERROR;
}
if (rc == SSH_AGAIN) {
/* return without freeing the (*aio) */
return SSH_AGAIN;
}
/*
* Release memory for the structure that (*aio) points to
* as all further points of return are for success or
* failure.
*/
SFTP_AIO_FREE(*aio);
switch (msg->packet_type) {
case SSH_FXP_STATUS:
status = parse_status_msg(msg);
sftp_message_free(msg);
if (status == NULL) {
return SSH_ERROR;
}
sftp_set_error(sftp, status->status);
if (status->status != SSH_FX_EOF) {
ssh_set_error(sftp->session, SSH_REQUEST_DENIED,
"SFTP server : %s", status->errormsg);
err = SSH_ERROR;
} else {
file->eof = 1;
/* Update the offset correctly */
file->offset = file->offset - bytes_requested;
err = SSH_OK;
}
status_msg_free(status);
return err;
case SSH_FXP_DATA:
rc = ssh_buffer_get_u32(msg->payload, &string_len);
if (rc == 0) {
/* Insufficient data in the buffer */
ssh_set_error(sftp->session, SSH_FATAL,
"Received invalid DATA packet from sftp server");
sftp_set_error(sftp, SSH_FX_BAD_MESSAGE);
sftp_message_free(msg);
return SSH_ERROR;
}
host_len = ntohl(string_len);
if (host_len > buf_size) {
/*
* This should never happen, as according to the
* SFTP protocol the server reads bytes less than
* or equal to the number of bytes requested to read.
*
* And we have checked before that the buffer size is
* greater than or equal to the number of bytes requested
* to read, hence code of this if block should never
* get executed.
*/
ssh_set_error(sftp->session, SSH_FATAL,
"DATA packet (%u bytes) received from sftp server "
"cannot fit into the supplied buffer (%zu bytes)",
host_len, buf_size);
sftp_set_error(sftp, SSH_FX_FAILURE);
sftp_message_free(msg);
return SSH_ERROR;
}
string_len = ssh_buffer_get_data(msg->payload, buf, host_len);
if (string_len != host_len) {
/* should never happen */
ssh_set_error(sftp->session, SSH_FATAL,
"Received invalid DATA packet from sftp server");
sftp_set_error(sftp, SSH_FX_BAD_MESSAGE);
sftp_message_free(msg);
return SSH_ERROR;
}
/* Update the offset with the correct value */
file->offset = file->offset - (bytes_requested - string_len);
sftp_message_free(msg);
return string_len;
default:
ssh_set_error(sftp->session, SSH_FATAL,
"Received message %d during read!", msg->packet_type);
sftp_set_error(sftp, SSH_FX_BAD_MESSAGE);
sftp_message_free(msg);
return SSH_ERROR;
}
return SSH_ERROR; /* not reached */
}
ssize_t sftp_aio_begin_write(sftp_file file,
const void *buf,
size_t len,
sftp_aio *aio)
{
sftp_session sftp = NULL;
ssh_buffer buffer = NULL;
sftp_aio aio_handle = NULL;
uint32_t id;
int rc;
if (file == NULL ||
file->sftp == NULL ||
file->sftp->session == NULL) {
return SSH_ERROR;
}
sftp = file->sftp;
if (buf == NULL) {
ssh_set_error(sftp->session, SSH_FATAL,
"Invalid argument, NULL passed instead "
"of a buffer's address");
sftp_set_error(sftp, SSH_FX_FAILURE);
return SSH_ERROR;
}
if (len == 0) {
ssh_set_error(sftp->session, SSH_FATAL,
"Invalid argument, 0 passed as the number "
"of bytes to write");
sftp_set_error(sftp, SSH_FX_FAILURE);
return SSH_ERROR;
}
/* Apply a cap on the length a user is allowed to write */
if (len > sftp->limits->max_write_length) {
if (sftp->limits->max_write_length > SIZE_MAX) {
return SSH_ERROR;
}
len = (size_t)sftp->limits->max_write_length;
}
if (aio == NULL) {
ssh_set_error(sftp->session, SSH_FATAL,
"Invalid argument, NULL passed instead of a pointer to "
"a location to store an sftp aio handle");
sftp_set_error(sftp, SSH_FX_FAILURE);
return SSH_ERROR;
}
buffer = ssh_buffer_new();
if (buffer == NULL) {
ssh_set_error_oom(sftp->session);
sftp_set_error(sftp, SSH_FX_FAILURE);
return SSH_ERROR;
}
id = sftp_get_new_id(sftp);
rc = ssh_buffer_pack(buffer,
"dSqdP",
id,
file->handle,
file->offset,
len, /* len of datastring */
len, buf);
if (rc != SSH_OK) {
ssh_set_error_oom(sftp->session);
sftp_set_error(sftp, SSH_FX_FAILURE);
SSH_BUFFER_FREE(buffer);
return SSH_ERROR;
}
aio_handle = sftp_aio_new();
if (aio_handle == NULL) {
ssh_set_error_oom(sftp->session);
sftp_set_error(sftp, SSH_FX_FAILURE);
SSH_BUFFER_FREE(buffer);
return SSH_ERROR;
}
aio_handle->file = file;
aio_handle->id = id;
aio_handle->len = len;
rc = sftp_packet_write(sftp, SSH_FXP_WRITE, buffer);
SSH_BUFFER_FREE(buffer);
if (rc == SSH_ERROR) {
SFTP_AIO_FREE(aio_handle);
return SSH_ERROR;
}
/* Assume we wrote len bytes to the file */
file->offset += len;
*aio = aio_handle;
return len;
}
ssize_t sftp_aio_wait_write(sftp_aio *aio)
{
sftp_file file = NULL;
size_t bytes_requested;
sftp_session sftp = NULL;
sftp_message msg = NULL;
sftp_status_message status = NULL;
int rc;
/*
* This function releases the memory of the structure
* that (*aio) points to in all cases except when the
* return value is SSH_AGAIN.
*
* If the return value is SSH_AGAIN, the user should call this
* function again to get the response for the request corresponding
* to the structure that (*aio) points to, hence we don't release the
* structure's memory when SSH_AGAIN is returned.
*/
if (aio == NULL || *aio == NULL) {
return SSH_ERROR;
}
file = (*aio)->file;
bytes_requested = (*aio)->len;
if (file == NULL ||
file->sftp == NULL ||
file->sftp->session == NULL) {
SFTP_AIO_FREE(*aio);
return SSH_ERROR;
}
sftp = file->sftp;
if (bytes_requested == 0) {
/* This should never happen */
ssh_set_error(sftp->session, SSH_FATAL,
"Invalid sftp aio, len for requested i/o is 0");
sftp_set_error(sftp, SSH_FX_FAILURE);
SFTP_AIO_FREE(*aio);
return SSH_ERROR;
}
rc = sftp_recv_response_msg(sftp, (*aio)->id, !file->nonblocking, &msg);
if (rc == SSH_ERROR) {
SFTP_AIO_FREE(*aio);
return SSH_ERROR;
}
if (rc == SSH_AGAIN) {
/* Return without freeing the (*aio) */
return SSH_AGAIN;
}
/*
* Release memory for the structure that (*aio) points to
* as all further points of return are for success or
* failure.
*/
SFTP_AIO_FREE(*aio);
if (msg->packet_type == SSH_FXP_STATUS) {
status = parse_status_msg(msg);
sftp_message_free(msg);
if (status == NULL) {
return SSH_ERROR;
}
sftp_set_error(sftp, status->status);
if (status->status == SSH_FX_OK) {
status_msg_free(status);
return bytes_requested;
}
ssh_set_error(sftp->session, SSH_REQUEST_DENIED,
"SFTP server: %s", status->errormsg);
status_msg_free(status);
return SSH_ERROR;
}
ssh_set_error(sftp->session, SSH_FATAL,
"Received message %d during write!",
msg->packet_type);
sftp_message_free(msg);
sftp_set_error(sftp, SSH_FX_BAD_MESSAGE);
return SSH_ERROR;
}
#endif /* WITH_SFTP */
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