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sftp: Reformat read/write functions

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Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
This commit is contained in:
Jakub Jelen
2025-01-13 13:50:48 +01:00
parent 00fce9cb6c
commit 4af88c84d4
1 changed files with 329 additions and 304 deletions
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633
src/sftp.c
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@@ -1131,365 +1131,390 @@ void sftp_file_set_blocking(sftp_file handle)
}
/* Read from a file using an opened sftp file handle. */
ssize_t sftp_read(sftp_file handle, void *buf, size_t count) {
sftp_session sftp;
sftp_message msg = NULL;
sftp_status_message status;
ssh_string datastring;
size_t datalen;
ssh_buffer buffer;
uint32_t id;
int rc;
ssize_t
sftp_read(sftp_file handle, void *buf, size_t count)
{
sftp_session sftp = NULL;
sftp_message msg = NULL;
sftp_status_message status;
ssh_string datastring = NULL;
size_t datalen;
ssh_buffer buffer = NULL;
uint32_t id;
int rc;
if (handle == NULL) {
return -1;
}
sftp = handle->sftp;
if (handle == NULL) {
return -1;
}
sftp = handle->sftp;
if (handle->eof) {
return 0;
}
if (handle->eof) {
return 0;
}
/*
* limit the reads to the maximum specified in Section 3 of
* https://datatracker.ietf.org/doc/html/draft-ietf-secsh-filexfer-02
* or to the values provided by the limits@openssh.com extension.
*
* TODO: We should iterate over the blocks rather than writing less than
* requested to provide less surprises to the calling applications.
*/
if (count > sftp->limits->max_read_length) {
if (sftp->limits->max_read_length > SIZE_MAX) {
return SSH_ERROR;
}
count = (size_t)sftp->limits->max_read_length;
}
/*
* limit the reads to the maximum specified in Section 3 of
* https://datatracker.ietf.org/doc/html/draft-ietf-secsh-filexfer-02
* or to the values provided by the limits@openssh.com extension.
*
* TODO: We should iterate over the blocks rather than writing less than
* requested to provide less surprises to the calling applications.
*/
if (count > sftp->limits->max_read_length) {
if (sftp->limits->max_read_length > SIZE_MAX) {
return SSH_ERROR;
}
count = (size_t)sftp->limits->max_read_length;
}
buffer = ssh_buffer_new();
if (buffer == NULL) {
ssh_set_error_oom(sftp->session);
return -1;
}
buffer = ssh_buffer_new();
if (buffer == NULL) {
ssh_set_error_oom(sftp->session);
return -1;
}
id = sftp_get_new_id(handle->sftp);
id = sftp_get_new_id(handle->sftp);
rc = ssh_buffer_pack(buffer,
"dSqd",
id,
handle->handle,
handle->offset,
count);
if (rc != SSH_OK){
ssh_set_error_oom(sftp->session);
rc = ssh_buffer_pack(buffer,
"dSqd",
id,
handle->handle,
handle->offset,
count);
if (rc != SSH_OK) {
ssh_set_error_oom(sftp->session);
SSH_BUFFER_FREE(buffer);
sftp_set_error(sftp, SSH_FX_FAILURE);
return -1;
}
if (sftp_packet_write(handle->sftp, SSH_FXP_READ, buffer) < 0) {
SSH_BUFFER_FREE(buffer);
return -1;
}
SSH_BUFFER_FREE(buffer);
sftp_set_error(sftp, SSH_FX_FAILURE);
return -1;
}
if (sftp_packet_write(handle->sftp, SSH_FXP_READ, buffer) < 0) {
SSH_BUFFER_FREE(buffer);
return -1;
}
SSH_BUFFER_FREE(buffer);
rc = sftp_recv_response_msg(handle->sftp, id, !handle->nonblocking, &msg);
if (rc == SSH_ERROR) {
return -1;
}
rc = sftp_recv_response_msg(handle->sftp, id, !handle->nonblocking, &msg);
if (rc == SSH_ERROR) {
return -1;
}
if (rc == SSH_AGAIN) {
/*
* file opened in non blocking mode and the response has not arrived yet.
* Since we cannot block, return 0 as the number of bytes read.
*/
return 0;
}
if (rc == SSH_AGAIN) {
/*
* file opened in non blocking mode and the response has not arrived
* yet. Since we cannot block, return 0 as the number of bytes read.
*/
return 0;
}
switch (msg->packet_type) {
switch (msg->packet_type) {
case SSH_FXP_STATUS:
status = parse_status_msg(msg);
sftp_message_free(msg);
if (status == NULL) {
return -1;
}
sftp_set_error(sftp, status->status);
switch (status->status) {
status = parse_status_msg(msg);
sftp_message_free(msg);
if (status == NULL) {
return -1;
}
sftp_set_error(sftp, status->status);
switch (status->status) {
case SSH_FX_EOF:
handle->eof = 1;
status_msg_free(status);
return 0;
handle->eof = 1;
status_msg_free(status);
return 0;
default:
break;
}
ssh_set_error(sftp->session,SSH_REQUEST_DENIED,
"SFTP server: %s", status->errormsg);
status_msg_free(status);
return -1;
break;
}
ssh_set_error(sftp->session,
SSH_REQUEST_DENIED,
"SFTP server: %s",
status->errormsg);
status_msg_free(status);
return -1;
case SSH_FXP_DATA:
datastring = ssh_buffer_get_ssh_string(msg->payload);
sftp_message_free(msg);
if (datastring == NULL) {
ssh_set_error(sftp->session, SSH_FATAL,
"Received invalid DATA packet from sftp server");
return -1;
}
datastring = ssh_buffer_get_ssh_string(msg->payload);
sftp_message_free(msg);
if (datastring == NULL) {
ssh_set_error(sftp->session,
SSH_FATAL,
"Received invalid DATA packet from sftp server");
return -1;
}
datalen = ssh_string_len(datastring);
if (datalen > count) {
ssh_set_error(sftp->session, SSH_FATAL,
"Received a too big DATA packet from sftp server: "
"%zu and asked for %zu",
datalen, count);
datalen = ssh_string_len(datastring);
if (datalen > count) {
ssh_set_error(sftp->session,
SSH_FATAL,
"Received a too big DATA packet from sftp server: "
"%zu and asked for %zu",
datalen,
count);
SSH_STRING_FREE(datastring);
return -1;
}
handle->offset += (uint64_t)datalen;
memcpy(buf, ssh_string_data(datastring), datalen);
SSH_STRING_FREE(datastring);
return -1;
}
handle->offset += (uint64_t)datalen;
memcpy(buf, ssh_string_data(datastring), datalen);
SSH_STRING_FREE(datastring);
return datalen;
return datalen;
default:
ssh_set_error(sftp->session, SSH_FATAL,
"Received message %d during read!", msg->packet_type);
sftp_message_free(msg);
sftp_set_error(sftp, SSH_FX_BAD_MESSAGE);
return -1;
}
ssh_set_error(sftp->session,
SSH_FATAL,
"Received message %d during read!",
msg->packet_type);
sftp_message_free(msg);
sftp_set_error(sftp, SSH_FX_BAD_MESSAGE);
return -1;
}
return -1; /* not reached */
return -1; /* not reached */
}
/* Start an asynchronous read from a file using an opened sftp file handle. */
int sftp_async_read_begin(sftp_file file, uint32_t len){
sftp_session sftp = file->sftp;
ssh_buffer buffer;
uint32_t id;
int rc;
int
sftp_async_read_begin(sftp_file file, uint32_t len)
{
sftp_session sftp = file->sftp;
ssh_buffer buffer = NULL;
uint32_t id;
int rc;
buffer = ssh_buffer_new();
if (buffer == NULL) {
ssh_set_error_oom(sftp->session);
sftp_set_error(sftp, SSH_FX_FAILURE);
return -1;
}
buffer = ssh_buffer_new();
if (buffer == NULL) {
ssh_set_error_oom(sftp->session);
sftp_set_error(sftp, SSH_FX_FAILURE);
return -1;
}
id = sftp_get_new_id(sftp);
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);
rc = ssh_buffer_pack(buffer, "dSqd", id, file->handle, file->offset, len);
if (rc != SSH_OK) {
ssh_set_error_oom(sftp->session);
SSH_BUFFER_FREE(buffer);
sftp_set_error(sftp, SSH_FX_FAILURE);
return -1;
}
if (sftp_packet_write(sftp, SSH_FXP_READ, buffer) < 0) {
SSH_BUFFER_FREE(buffer);
return -1;
}
SSH_BUFFER_FREE(buffer);
sftp_set_error(sftp, SSH_FX_FAILURE);
return -1;
}
if (sftp_packet_write(sftp, SSH_FXP_READ, buffer) < 0) {
SSH_BUFFER_FREE(buffer);
return -1;
}
SSH_BUFFER_FREE(buffer);
file->offset += len; /* assume we'll read len bytes */
file->offset += len; /* assume we'll read len bytes */
return id;
return id;
}
/* Wait for an asynchronous read to complete and save the data. */
int sftp_async_read(sftp_file file, void *data, uint32_t size, uint32_t id){
sftp_session sftp;
sftp_message msg = NULL;
sftp_status_message status;
ssh_string datastring;
int rc, err = SSH_OK;
size_t len;
int
sftp_async_read(sftp_file file, void *data, uint32_t size, uint32_t id)
{
sftp_session sftp = NULL;
sftp_message msg = NULL;
sftp_status_message status;
ssh_string datastring = NULL;
int rc, err = SSH_OK;
size_t len;
if (file == NULL) {
return SSH_ERROR;
}
sftp = file->sftp;
if (file == NULL) {
return SSH_ERROR;
}
sftp = file->sftp;
if (file->eof) {
return 0;
}
if (file->eof) {
return 0;
}
/* handle an existing request */
rc = sftp_recv_response_msg(sftp, id, !file->nonblocking, &msg);
if (rc == SSH_ERROR || rc == SSH_AGAIN) {
return rc;
}
/* handle an existing request */
rc = sftp_recv_response_msg(sftp, id, !file->nonblocking, &msg);
if (rc == SSH_ERROR || rc == SSH_AGAIN) {
return rc;
}
switch (msg->packet_type) {
switch (msg->packet_type) {
case SSH_FXP_STATUS:
status = parse_status_msg(msg);
sftp_message_free(msg);
if (status == NULL) {
return -1;
}
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;
}
status_msg_free(status);
return err;
status = parse_status_msg(msg);
sftp_message_free(msg);
if (status == NULL) {
return -1;
}
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;
}
status_msg_free(status);
return err;
case SSH_FXP_DATA:
datastring = ssh_buffer_get_ssh_string(msg->payload);
sftp_message_free(msg);
if (datastring == NULL) {
ssh_set_error(sftp->session, SSH_FATAL,
"Received invalid DATA packet from sftp server");
return SSH_ERROR;
}
if (ssh_string_len(datastring) > size) {
ssh_set_error(sftp->session, SSH_FATAL,
"Received a too big DATA packet from sftp server: "
"%zu and asked for %" PRIu32,
ssh_string_len(datastring), size);
datastring = ssh_buffer_get_ssh_string(msg->payload);
sftp_message_free(msg);
if (datastring == NULL) {
ssh_set_error(sftp->session,
SSH_FATAL,
"Received invalid DATA packet from sftp server");
return SSH_ERROR;
}
if (ssh_string_len(datastring) > size) {
ssh_set_error(sftp->session,
SSH_FATAL,
"Received a too big DATA packet from sftp server: "
"%zu and asked for %" PRIu32,
ssh_string_len(datastring),
size);
SSH_STRING_FREE(datastring);
return SSH_ERROR;
}
len = ssh_string_len(datastring);
/* Update the offset with the correct value */
file->offset = file->offset - (size - len);
memcpy(data, ssh_string_data(datastring), len);
SSH_STRING_FREE(datastring);
return (int)len;
default:
ssh_set_error(sftp->session,
SSH_FATAL,
"Received message %d during read!",
msg->packet_type);
sftp_message_free(msg);
sftp_set_error(sftp, SSH_FX_BAD_MESSAGE);
return SSH_ERROR;
}
len = ssh_string_len(datastring);
/* Update the offset with the correct value */
file->offset = file->offset - (size - len);
memcpy(data, ssh_string_data(datastring), len);
SSH_STRING_FREE(datastring);
return (int)len;
default:
ssh_set_error(sftp->session,SSH_FATAL,"Received message %d during read!",msg->packet_type);
sftp_message_free(msg);
sftp_set_error(sftp, SSH_FX_BAD_MESSAGE);
return SSH_ERROR;
}
}
return SSH_ERROR;
return SSH_ERROR;
}
ssize_t sftp_write(sftp_file file, const void *buf, size_t count) {
sftp_session sftp;
sftp_message msg = NULL;
sftp_status_message status;
ssh_buffer buffer;
uint32_t id;
ssize_t len;
size_t packetlen;
int rc;
ssize_t
sftp_write(sftp_file file, const void *buf, size_t count)
{
sftp_session sftp = NULL;
sftp_message msg = NULL;
sftp_status_message status;
ssh_buffer buffer = NULL;
uint32_t id;
ssize_t len;
size_t packetlen;
int rc;
if (file == NULL) {
return -1;
}
sftp = file->sftp;
buffer = ssh_buffer_new();
if (buffer == NULL) {
ssh_set_error_oom(sftp->session);
sftp_set_error(sftp, SSH_FX_FAILURE);
return -1;
}
id = sftp_get_new_id(file->sftp);
/*
* limit the writes to the maximum specified in Section 3 of
* https://datatracker.ietf.org/doc/html/draft-ietf-secsh-filexfer-02
* or to the values provided by the limits@openssh.com extension.
*
* TODO: We should iterate over the blocks rather than writing less than
* requested to provide less surprises to the calling applications.
*/
if (count > sftp->limits->max_write_length) {
if (sftp->limits->max_write_length > SIZE_MAX) {
return SSH_ERROR;
}
count = (size_t)sftp->limits->max_write_length;
}
rc = ssh_buffer_pack(buffer,
"dSqdP",
id,
file->handle,
file->offset,
count, /* len of datastring */
(size_t)count, buf);
if (rc != SSH_OK){
ssh_set_error_oom(sftp->session);
SSH_BUFFER_FREE(buffer);
sftp_set_error(sftp, SSH_FX_FAILURE);
return -1;
}
len = sftp_packet_write(file->sftp, SSH_FXP_WRITE, buffer);
packetlen=ssh_buffer_get_len(buffer);
SSH_BUFFER_FREE(buffer);
if (len < 0) {
return -1;
} else if ((size_t)len != packetlen) {
SSH_LOG(SSH_LOG_PACKET,
"Could not write as much data as expected");
}
/* Wait for the response in blocking mode */
rc = sftp_recv_response_msg(sftp, id, true, &msg);
if (rc != SSH_OK) {
return -1;
}
switch (msg->packet_type) {
case SSH_FXP_STATUS:
status = parse_status_msg(msg);
sftp_message_free(msg);
if (status == NULL) {
if (file == NULL) {
return -1;
}
sftp_set_error(sftp, status->status);
switch (status->status) {
}
sftp = file->sftp;
buffer = ssh_buffer_new();
if (buffer == NULL) {
ssh_set_error_oom(sftp->session);
sftp_set_error(sftp, SSH_FX_FAILURE);
return -1;
}
id = sftp_get_new_id(file->sftp);
/*
* limit the writes to the maximum specified in Section 3 of
* https://datatracker.ietf.org/doc/html/draft-ietf-secsh-filexfer-02
* or to the values provided by the limits@openssh.com extension.
*
* TODO: We should iterate over the blocks rather than writing less than
* requested to provide less surprises to the calling applications.
*/
if (count > sftp->limits->max_write_length) {
if (sftp->limits->max_write_length > SIZE_MAX) {
return SSH_ERROR;
}
count = (size_t)sftp->limits->max_write_length;
}
rc = ssh_buffer_pack(buffer,
"dSqdP",
id,
file->handle,
file->offset,
count, /* len of datastring */
(size_t)count, buf);
if (rc != SSH_OK) {
ssh_set_error_oom(sftp->session);
SSH_BUFFER_FREE(buffer);
sftp_set_error(sftp, SSH_FX_FAILURE);
return -1;
}
len = sftp_packet_write(file->sftp, SSH_FXP_WRITE, buffer);
packetlen = ssh_buffer_get_len(buffer);
SSH_BUFFER_FREE(buffer);
if (len < 0) {
return -1;
} else if ((size_t)len != packetlen) {
SSH_LOG(SSH_LOG_PACKET, "Could not write as much data as expected");
}
/* Wait for the response in blocking mode */
rc = sftp_recv_response_msg(sftp, id, true, &msg);
if (rc != SSH_OK) {
return -1;
}
switch (msg->packet_type) {
case SSH_FXP_STATUS:
status = parse_status_msg(msg);
sftp_message_free(msg);
if (status == NULL) {
return -1;
}
sftp_set_error(sftp, status->status);
switch (status->status) {
case SSH_FX_OK:
file->offset += count;
status_msg_free(status);
return count;
file->offset += count;
status_msg_free(status);
return count;
default:
break;
}
ssh_set_error(sftp->session, SSH_REQUEST_DENIED,
"SFTP server: %s", status->errormsg);
file->offset += count;
status_msg_free(status);
return -1;
break;
}
ssh_set_error(sftp->session,
SSH_REQUEST_DENIED,
"SFTP server: %s",
status->errormsg);
file->offset += count;
status_msg_free(status);
return -1;
default:
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 -1;
}
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 -1;
}
return -1; /* not reached */
return -1; /* not reached */
}
/* Seek to a specific location in a file. */
int sftp_seek(sftp_file file, uint32_t new_offset) {
if (file == NULL) {
return -1;
}
/* Seek to a specific location in a file. */
int
sftp_seek(sftp_file file, uint32_t new_offset)
{
if (file == NULL) {
return -1;
}
file->offset = new_offset;
file->eof = 0;
file->offset = new_offset;
file->eof = 0;
return 0;
return 0;
}
int sftp_seek64(sftp_file file, uint64_t new_offset) {
if (file == NULL) {
return -1;
}
int
sftp_seek64(sftp_file file, uint64_t new_offset)
{
if (file == NULL) {
return -1;
}
file->offset = new_offset;
file->eof = 0;
file->offset = new_offset;
file->eof = 0;
return 0;
return 0;
}
/* Report current byte position in file. */