/** @file * * PXE TFTP API * */ /* * Copyright (C) 2004 Michael Brown . * * 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. */ #include #include #include #include #include #include #include #include #include #include #include /** 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; /* Mildly ugly hack; assume that the first non-zero seek * indicates the block size. */ if ( pxe_tftp.blksize == 0 ) pxe_tftp.blksize = pxe_tftp.offset; /* 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_vopen, .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 ) { 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:%d%s%s?blksize=%d", 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 ) { 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.blksize == 0 ) ) { step(); } tftp_open->PacketSize = pxe_tftp.blksize; /* 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 %08lx+%lx", 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 ) { 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 ) ) != 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; /* 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 ); }