/** @file
*
* PXE TFTP API
*
*/
/*
* Copyright (C) 2004 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program 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
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
FILE_LICENCE ( GPL2_OR_LATER );
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <byteswap.h>
#include <gpxe/uaccess.h>
#include <gpxe/in.h>
#include <gpxe/tftp.h>
#include <gpxe/xfer.h>
#include <gpxe/open.h>
#include <gpxe/process.h>
#include <pxe.h>
/** A PXE TFTP connection */
struct pxe_tftp_connection {
/** Data transfer interface */
struct xfer_interface xfer;
/** Data buffer */
userptr_t buffer;
/** Size of data buffer */
size_t size;
/** Starting offset of data buffer */
size_t start;
/** File position */
size_t offset;
/** Maximum file position */
size_t max_offset;
/** Block size */
size_t blksize;
/** Block index */
unsigned int blkidx;
/** Overall return status code */
int rc;
};
/** The PXE TFTP connection */
static struct pxe_tftp_connection pxe_tftp = {
.xfer = XFER_INIT ( &null_xfer_ops ),
};
/**
* Close PXE TFTP connection
*
* @v rc Final status code
*/
static void pxe_tftp_close ( int rc ) {
xfer_nullify ( &pxe_tftp.xfer );
xfer_close ( &pxe_tftp.xfer, rc );
pxe_tftp.rc = rc;
}
/**
* Receive new data
*
* @v xfer Data transfer interface
* @v iobuf I/O buffer
* @v meta Transfer metadata
* @ret rc Return status code
*/
static int pxe_tftp_xfer_deliver_iob ( struct xfer_interface *xfer __unused,
struct io_buffer *iobuf,
struct xfer_metadata *meta ) {
size_t len = iob_len ( iobuf );
int rc = 0;
/* Calculate new buffer position */
if ( meta->whence != SEEK_CUR )
pxe_tftp.offset = 0;
pxe_tftp.offset += meta->offset;
/* Copy data block to buffer */
if ( len == 0 ) {
/* No data (pure seek); treat as success */
} else if ( pxe_tftp.offset < pxe_tftp.start ) {
DBG ( " buffer underrun at %zx (min %zx)",
pxe_tftp.offset, pxe_tftp.start );
rc = -ENOBUFS;
} else if ( ( pxe_tftp.offset + len ) >
( pxe_tftp.start + pxe_tftp.size ) ) {
DBG ( " buffer overrun at %zx (max %zx)",
( pxe_tftp.offset + len ),
( pxe_tftp.start + pxe_tftp.size ) );
rc = -ENOBUFS;
} else {
copy_to_user ( pxe_tftp.buffer,
( pxe_tftp.offset - pxe_tftp.start ),
iobuf->data, len );
}
/* Calculate new buffer position */
pxe_tftp.offset += len;
/* Record maximum offset as the file size */
if ( pxe_tftp.max_offset < pxe_tftp.offset )
pxe_tftp.max_offset = pxe_tftp.offset;
/* Terminate transfer on error */
if ( rc != 0 )
pxe_tftp_close ( rc );
free_iob ( iobuf );
return rc;
}
/**
* Handle close() event
*
* @v xfer Data transfer interface
* @v rc Reason for close
*/
static void pxe_tftp_xfer_close ( struct xfer_interface *xfer __unused,
int rc ) {
pxe_tftp_close ( rc );
}
static struct xfer_interface_operations pxe_tftp_xfer_ops = {
.close = pxe_tftp_xfer_close,
.vredirect = xfer_vreopen,
.window = unlimited_xfer_window,
.alloc_iob = default_xfer_alloc_iob,
.deliver_iob = pxe_tftp_xfer_deliver_iob,
.deliver_raw = xfer_deliver_as_iob,
};
/**
* Maximum length of a PXE TFTP URI
*
* The PXE TFTP API provides 128 characters for the filename; the
* extra 128 bytes allow for the remainder of the URI.
*/
#define PXE_TFTP_URI_LEN 256
/**
* Open PXE TFTP connection
*
* @v ipaddress IP address
* @v port TFTP server port
* @v filename File name
* @v blksize Requested block size
* @ret rc Return status code
*/
static int pxe_tftp_open ( uint32_t ipaddress, unsigned int port,
const unsigned char *filename, size_t blksize,
int sizeonly ) {
char uri_string[PXE_TFTP_URI_LEN];
struct in_addr address;
int rc;
/* Intel bug-for-bug hack */
pxe_set_cached_filename ( filename );
/* Reset PXE TFTP connection structure */
memset ( &pxe_tftp, 0, sizeof ( pxe_tftp ) );
xfer_init ( &pxe_tftp.xfer, &pxe_tftp_xfer_ops, NULL );
pxe_tftp.rc = -EINPROGRESS;
/* Construct URI string */
address.s_addr = ipaddress;
if ( ! port )
port = htons ( TFTP_PORT );
if ( blksize < TFTP_DEFAULT_BLKSIZE )
blksize = TFTP_DEFAULT_BLKSIZE;
snprintf ( uri_string, sizeof ( uri_string ),
"tftp%s://%s:%d%s%s?blksize=%zd",
sizeonly ? "size" : "",
inet_ntoa ( address ), ntohs ( port ),
( ( filename[0] == '/' ) ? "" : "/" ), filename, blksize );
DBG ( " %s", uri_string );
/* Open PXE TFTP connection */
if ( ( rc = xfer_open_uri_string ( &pxe_tftp.xfer,
uri_string ) ) != 0 ) {
DBG ( " could not open (%s)\n", strerror ( rc ) );
return rc;
}
return 0;
}
/**
* TFTP OPEN
*
* @v tftp_open Pointer to a struct s_PXENV_TFTP_OPEN
* @v s_PXENV_TFTP_OPEN::ServerIPAddress TFTP server IP address
* @v s_PXENV_TFTP_OPEN::GatewayIPAddress Relay agent IP address, or 0.0.0.0
* @v s_PXENV_TFTP_OPEN::FileName Name of file to open
* @v s_PXENV_TFTP_OPEN::TFTPPort TFTP server UDP port
* @v s_PXENV_TFTP_OPEN::PacketSize TFTP blksize option to request
* @ret #PXENV_EXIT_SUCCESS File was opened
* @ret #PXENV_EXIT_FAILURE File was not opened
* @ret s_PXENV_TFTP_OPEN::Status PXE status code
* @ret s_PXENV_TFTP_OPEN::PacketSize Negotiated blksize
* @err #PXENV_STATUS_TFTP_INVALID_PACKET_SIZE Requested blksize too small
*
* Opens a TFTP connection for downloading a file a block at a time
* using pxenv_tftp_read().
*
* If s_PXENV_TFTP_OPEN::GatewayIPAddress is 0.0.0.0, normal IP
* routing will take place. See the relevant
* @ref pxe_routing "implementation note" for more details.
*
* On x86, you must set the s_PXE::StatusCallout field to a nonzero
* value before calling this function in protected mode. You cannot
* call this function with a 32-bit stack segment. (See the relevant
* @ref pxe_x86_pmode16 "implementation note" for more details.)
*
* @note According to the PXE specification version 2.1, this call
* "opens a file for reading/writing", though how writing is to be
* achieved without the existence of an API call %pxenv_tftp_write()
* is not made clear.
*
* @note Despite the existence of the numerous statements within the
* PXE specification of the form "...if a TFTP/MTFTP or UDP connection
* is active...", you cannot use pxenv_tftp_open() and
* pxenv_tftp_read() to read a file via MTFTP; only via plain old
* TFTP. If you want to use MTFTP, use pxenv_tftp_read_file()
* instead. Astute readers will note that, since
* pxenv_tftp_read_file() is an atomic operation from the point of
* view of the PXE API, it is conceptually impossible to issue any
* other PXE API call "if an MTFTP connection is active".
*/
PXENV_EXIT_t pxenv_tftp_open ( struct s_PXENV_TFTP_OPEN *tftp_open ) {
int rc;
DBG ( "PXENV_TFTP_OPEN" );
/* Guard against callers that fail to close before re-opening */
pxe_tftp_close ( 0 );
/* Open connection */
if ( ( rc = pxe_tftp_open ( tftp_open->ServerIPAddress,
tftp_open->TFTPPort,
tftp_open->FileName,
tftp_open->PacketSize,
0) ) != 0 ) {
tftp_open->Status = PXENV_STATUS ( rc );
return PXENV_EXIT_FAILURE;
}
/* Wait for OACK to arrive so that we have the block size */
while ( ( ( rc = pxe_tftp.rc ) == -EINPROGRESS ) &&
( pxe_tftp.max_offset == 0 ) ) {
step();
}
pxe_tftp.blksize = xfer_window ( &pxe_tftp.xfer );
tftp_open->PacketSize = pxe_tftp.blksize;
DBG ( " blksize=%d", tftp_open->PacketSize );
/* EINPROGRESS is normal; we don't wait for the whole transfer */
if ( rc == -EINPROGRESS )
rc = 0;
tftp_open->Status = PXENV_STATUS ( rc );
return ( rc ? PXENV_EXIT_FAILURE : PXENV_EXIT_SUCCESS );
}
/**
* TFTP CLOSE
*
* @v tftp_close Pointer to a struct s_PXENV_TFTP_CLOSE
* @ret #PXENV_EXIT_SUCCESS File was closed successfully
* @ret #PXENV_EXIT_FAILURE File was not closed
* @ret s_PXENV_TFTP_CLOSE::Status PXE status code
* @err None -
*
* Close a connection previously opened with pxenv_tftp_open(). You
* must have previously opened a connection with pxenv_tftp_open().
*
* On x86, you must set the s_PXE::StatusCallout field to a nonzero
* value before calling this function in protected mode. You cannot
* call this function with a 32-bit stack segment. (See the relevant
* @ref pxe_x86_pmode16 "implementation note" for more details.)
*/
PXENV_EXIT_t pxenv_tftp_close ( struct s_PXENV_TFTP_CLOSE *tftp_close ) {
DBG ( "PXENV_TFTP_CLOSE" );
pxe_tftp_close ( 0 );
tftp_close->Status = PXENV_STATUS_SUCCESS;
return PXENV_EXIT_SUCCESS;
}
/**
* TFTP READ
*
* @v tftp_read Pointer to a struct s_PXENV_TFTP_READ
* @v s_PXENV_TFTP_READ::Buffer Address of data buffer
* @ret #PXENV_EXIT_SUCCESS Data was read successfully
* @ret #PXENV_EXIT_FAILURE Data was not read
* @ret s_PXENV_TFTP_READ::Status PXE status code
* @ret s_PXENV_TFTP_READ::PacketNumber TFTP packet number
* @ret s_PXENV_TFTP_READ::BufferSize Length of data written into buffer
*
* Reads a single packet from a connection previously opened with
* pxenv_tftp_open() into the data buffer pointed to by
* s_PXENV_TFTP_READ::Buffer. You must have previously opened a
* connection with pxenv_tftp_open(). The data written into
* s_PXENV_TFTP_READ::Buffer is just the file data; the various
* network headers have already been removed.
*
* The buffer must be large enough to contain a packet of the size
* negotiated via the s_PXENV_TFTP_OPEN::PacketSize field in the
* pxenv_tftp_open() call. It is worth noting that the PXE
* specification does @b not require the caller to fill in
* s_PXENV_TFTP_READ::BufferSize before calling pxenv_tftp_read(), so
* the PXE stack is free to ignore whatever value the caller might
* place there and just assume that the buffer is large enough. That
* said, it may be worth the caller always filling in
* s_PXENV_TFTP_READ::BufferSize to guard against PXE stacks that
* mistake it for an input parameter.
*
* The length of the TFTP data packet will be returned via
* s_PXENV_TFTP_READ::BufferSize. If this length is less than the
* blksize negotiated via s_PXENV_TFTP_OPEN::PacketSize in the call to
* pxenv_tftp_open(), this indicates that the block is the last block
* in the file. Note that zero is a valid length for
* s_PXENV_TFTP_READ::BufferSize, and will occur when the length of
* the file is a multiple of the blksize.
*
* The PXE specification doesn't actually state that calls to
* pxenv_tftp_read() will return the data packets in strict sequential
* order, though most PXE stacks will probably do so. The sequence
* number of the packet will be returned in
* s_PXENV_TFTP_READ::PacketNumber. The first packet in the file has
* a sequence number of one, not zero.
*
* To guard against flawed PXE stacks, the caller should probably set
* s_PXENV_TFTP_READ::PacketNumber to one less than the expected
* returned value (i.e. set it to zero for the first call to
* pxenv_tftp_read() and then re-use the returned s_PXENV_TFTP_READ
* parameter block for subsequent calls without modifying
* s_PXENV_TFTP_READ::PacketNumber between calls). The caller should
* also guard against potential problems caused by flawed
* implementations returning the occasional duplicate packet, by
* checking that the value returned in s_PXENV_TFTP_READ::PacketNumber
* is as expected (i.e. one greater than that returned from the
* previous call to pxenv_tftp_read()).
*
* On x86, you must set the s_PXE::StatusCallout field to a nonzero
* value before calling this function in protected mode. You cannot
* call this function with a 32-bit stack segment. (See the relevant
* @ref pxe_x86_pmode16 "implementation note" for more details.)
*/
PXENV_EXIT_t pxenv_tftp_read ( struct s_PXENV_TFTP_READ *tftp_read ) {
int rc;
DBG ( "PXENV_TFTP_READ to %04x:%04x",
tftp_read->Buffer.segment, tftp_read->Buffer.offset );
/* Read single block into buffer */
pxe_tftp.buffer = real_to_user ( tftp_read->Buffer.segment,
tftp_read->Buffer.offset );
pxe_tftp.size = pxe_tftp.blksize;
pxe_tftp.start = pxe_tftp.offset;
while ( ( ( rc = pxe_tftp.rc ) == -EINPROGRESS ) &&
( pxe_tftp.offset == pxe_tftp.start ) )
step();
pxe_tftp.buffer = UNULL;
tftp_read->BufferSize = ( pxe_tftp.offset - pxe_tftp.start );
tftp_read->PacketNumber = ++pxe_tftp.blkidx;
/* EINPROGRESS is normal if we haven't reached EOF yet */
if ( rc == -EINPROGRESS )
rc = 0;
tftp_read->Status = PXENV_STATUS ( rc );
return ( rc ? PXENV_EXIT_FAILURE : PXENV_EXIT_SUCCESS );
}
/**
* TFTP/MTFTP read file
*
* @v tftp_read_file Pointer to a struct s_PXENV_TFTP_READ_FILE
* @v s_PXENV_TFTP_READ_FILE::FileName File name
* @v s_PXENV_TFTP_READ_FILE::BufferSize Size of the receive buffer
* @v s_PXENV_TFTP_READ_FILE::Buffer Address of the receive buffer
* @v s_PXENV_TFTP_READ_FILE::ServerIPAddress TFTP server IP address
* @v s_PXENV_TFTP_READ_FILE::GatewayIPAddress Relay agent IP address
* @v s_PXENV_TFTP_READ_FILE::McastIPAddress File's multicast IP address
* @v s_PXENV_TFTP_READ_FILE::TFTPClntPort Client multicast UDP port
* @v s_PXENV_TFTP_READ_FILE::TFTPSrvPort Server multicast UDP port
* @v s_PXENV_TFTP_READ_FILE::TFTPOpenTimeOut Time to wait for first packet
* @v s_PXENV_TFTP_READ_FILE::TFTPReopenDelay MTFTP inactivity timeout
* @ret #PXENV_EXIT_SUCCESS File downloaded successfully
* @ret #PXENV_EXIT_FAILURE File not downloaded
* @ret s_PXENV_TFTP_READ_FILE::Status PXE status code
* @ret s_PXENV_TFTP_READ_FILE::BufferSize Length of downloaded file
*
* Downloads an entire file via either TFTP or MTFTP into the buffer
* pointed to by s_PXENV_TFTP_READ_FILE::Buffer.
*
* The PXE specification does not make it clear how the caller
* requests that MTFTP be used rather than TFTP (or vice versa). One
* reasonable guess is that setting
* s_PXENV_TFTP_READ_FILE::McastIPAddress to 0.0.0.0 would cause TFTP
* to be used instead of MTFTP, though it is conceivable that some PXE
* stacks would interpret that as "use the DHCP-provided multicast IP
* address" instead. Some PXE stacks will not implement MTFTP at all,
* and will always use TFTP.
*
* It is not specified whether or not
* s_PXENV_TFTP_READ_FILE::TFTPSrvPort will be used as the TFTP server
* port for TFTP (rather than MTFTP) downloads. Callers should assume
* that the only way to access a TFTP server on a non-standard port is
* to use pxenv_tftp_open() and pxenv_tftp_read().
*
* If s_PXENV_TFTP_READ_FILE::GatewayIPAddress is 0.0.0.0, normal IP
* routing will take place. See the relevant
* @ref pxe_routing "implementation note" for more details.
*
* It is interesting to note that s_PXENV_TFTP_READ_FILE::Buffer is an
* #ADDR32_t type, i.e. nominally a flat physical address. Some PXE
* NBPs (e.g. NTLDR) are known to call pxenv_tftp_read_file() in real
* mode with s_PXENV_TFTP_READ_FILE::Buffer set to an address above
* 1MB. This means that PXE stacks must be prepared to write to areas
* outside base memory. Exactly how this is to be achieved is not
* specified, though using INT 15,87 is as close to a standard method
* as any, and should probably be used. Switching to protected-mode
* in order to access high memory will fail if pxenv_tftp_read_file()
* is called in V86 mode; it is reasonably to expect that a V86
* monitor would intercept the relatively well-defined INT 15,87 if it
* wants the PXE stack to be able to write to high memory.
*
* Things get even more interesting if pxenv_tftp_read_file() is
* called in protected mode, because there is then absolutely no way
* for the PXE stack to write to an absolute physical address. You
* can't even get around the problem by creating a special "access
* everything" segment in the s_PXE data structure, because the
* #SEGDESC_t descriptors are limited to 64kB in size.
*
* Previous versions of the PXE specification (e.g. WfM 1.1a) provide
* a separate API call, %pxenv_tftp_read_file_pmode(), specifically to
* work around this problem. The s_PXENV_TFTP_READ_FILE_PMODE
* parameter block splits s_PXENV_TFTP_READ_FILE::Buffer into
* s_PXENV_TFTP_READ_FILE_PMODE::BufferSelector and
* s_PXENV_TFTP_READ_FILE_PMODE::BufferOffset, i.e. it provides a
* protected-mode segment:offset address for the data buffer. This
* API call is no longer present in version 2.1 of the PXE
* specification.
*
* Etherboot makes the assumption that s_PXENV_TFTP_READ_FILE::Buffer
* is an offset relative to the caller's data segment, when
* pxenv_tftp_read_file() is called in protected mode.
*
* On x86, you must set the s_PXE::StatusCallout field to a nonzero
* value before calling this function in protected mode. You cannot
* call this function with a 32-bit stack segment. (See the relevant
* @ref pxe_x86_pmode16 "implementation note" for more details.)
*
* @note Microsoft's NTLDR assumes that the filename passed in via
* s_PXENV_TFTP_READ_FILE::FileName will be stored in the "file" field
* of the stored DHCPACK packet, whence it will be returned via any
* subsequent calls to pxenv_get_cached_info(). Though this is
* essentially a bug in the Intel PXE implementation (not, for once,
* in the specification!), it is a bug that Microsoft relies upon, and
* so we implement this bug-for-bug compatibility by overwriting the
* filename stored DHCPACK packet with the filename passed in
* s_PXENV_TFTP_READ_FILE::FileName.
*
*/
PXENV_EXIT_t pxenv_tftp_read_file ( struct s_PXENV_TFTP_READ_FILE
*tftp_read_file ) {
int rc;
DBG ( "PXENV_TFTP_READ_FILE to %08x+%x", tftp_read_file->Buffer,
tftp_read_file->BufferSize );
/* Open TFTP file */
if ( ( rc = pxe_tftp_open ( tftp_read_file->ServerIPAddress, 0,
tftp_read_file->FileName, 0, 0 ) ) != 0 ) {
tftp_read_file->Status = PXENV_STATUS ( rc );
return PXENV_EXIT_FAILURE;
}
/* Read entire file */
pxe_tftp.buffer = phys_to_user ( tftp_read_file->Buffer );
pxe_tftp.size = tftp_read_file->BufferSize;
while ( ( rc = pxe_tftp.rc ) == -EINPROGRESS )
step();
pxe_tftp.buffer = UNULL;
tftp_read_file->BufferSize = pxe_tftp.max_offset;
/* Close TFTP file */
pxe_tftp_close ( rc );
tftp_read_file->Status = PXENV_STATUS ( rc );
return ( rc ? PXENV_EXIT_FAILURE : PXENV_EXIT_SUCCESS );
}
/**
* TFTP GET FILE SIZE
*
* @v tftp_get_fsize Pointer to a struct s_PXENV_TFTP_GET_FSIZE
* @v s_PXENV_TFTP_GET_FSIZE::ServerIPAddress TFTP server IP address
* @v s_PXENV_TFTP_GET_FSIZE::GatewayIPAddress Relay agent IP address
* @v s_PXENV_TFTP_GET_FSIZE::FileName File name
* @ret #PXENV_EXIT_SUCCESS File size was determined successfully
* @ret #PXENV_EXIT_FAILURE File size was not determined
* @ret s_PXENV_TFTP_GET_FSIZE::Status PXE status code
* @ret s_PXENV_TFTP_GET_FSIZE::FileSize File size
*
* Determine the size of a file on a TFTP server. This uses the
* "tsize" TFTP option, and so will not work with a TFTP server that
* does not support TFTP options, or that does not support the "tsize"
* option.
*
* The PXE specification states that this API call will @b not open a
* TFTP connection for subsequent use with pxenv_tftp_read(). (This
* is somewhat daft, since the only way to obtain the file size via
* the "tsize" option involves issuing a TFTP open request, but that's
* life.)
*
* You cannot call pxenv_tftp_get_fsize() while a TFTP or UDP
* connection is open.
*
* If s_PXENV_TFTP_GET_FSIZE::GatewayIPAddress is 0.0.0.0, normal IP
* routing will take place. See the relevant
* @ref pxe_routing "implementation note" for more details.
*
* On x86, you must set the s_PXE::StatusCallout field to a nonzero
* value before calling this function in protected mode. You cannot
* call this function with a 32-bit stack segment. (See the relevant
* @ref pxe_x86_pmode16 "implementation note" for more details.)
*
* @note There is no way to specify the TFTP server port with this API
* call. Though you can open a file using a non-standard TFTP server
* port (via s_PXENV_TFTP_OPEN::TFTPPort or, potentially,
* s_PXENV_TFTP_READ_FILE::TFTPSrvPort), you can only get the size of
* a file from a TFTP server listening on the standard TFTP port.
* "Consistency" is not a word in Intel's vocabulary.
*/
PXENV_EXIT_t pxenv_tftp_get_fsize ( struct s_PXENV_TFTP_GET_FSIZE
*tftp_get_fsize ) {
int rc;
DBG ( "PXENV_TFTP_GET_FSIZE" );
/* Open TFTP file */
if ( ( rc = pxe_tftp_open ( tftp_get_fsize->ServerIPAddress, 0,
tftp_get_fsize->FileName, 0, 1 ) ) != 0 ) {
tftp_get_fsize->Status = PXENV_STATUS ( rc );
return PXENV_EXIT_FAILURE;
}
/* Wait for initial seek to arrive, and record size */
while ( ( ( rc = pxe_tftp.rc ) == -EINPROGRESS ) &&
( pxe_tftp.max_offset == 0 ) ) {
step();
}
tftp_get_fsize->FileSize = pxe_tftp.max_offset;
DBG ( " fsize=%d", tftp_get_fsize->FileSize );
/* EINPROGRESS is normal; we don't wait for the whole transfer */
if ( rc == -EINPROGRESS )
rc = 0;
/* Close TFTP file */
pxe_tftp_close ( rc );
tftp_get_fsize->Status = PXENV_STATUS ( rc );
return ( rc ? PXENV_EXIT_FAILURE : PXENV_EXIT_SUCCESS );
}