/** @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 /** File descriptor for "single-file-only" PXE TFTP transfer */ static int pxe_single_fd = -1; /** Block size for "single-file-only" PXE TFTP transfer */ static size_t pxe_single_blksize; /** Current block index for "single-file-only" PXE TFTP transfer */ static unsigned int pxe_single_blkidx; /** Length of a PXE-derived URI * * The "single-file-only" API calls use a filename field of 128 bytes. * 256 bytes provides plenty of space for constructing the (temporary) * full URI. */ #define PXE_URI_LEN 256 /** * Build PXE URI string * * @v uri_string URI string to fill in * @v ipaddress Server IP address (in network byte order) * @v port Server port (in network byte order) * @v filename File name * @v blksize Requested block size, or 0 * * The URI string buffer must be at least @c PXE_URI_LEN bytes long. */ static void pxe_tftp_build_uri ( char *uri_string, uint32_t ipaddress, unsigned int port, const unsigned char *filename, int blksize ) { struct in_addr address; address.s_addr = ipaddress; if ( ! port ) port = htons ( TFTP_PORT ); if ( ! blksize ) blksize = TFTP_MAX_BLKSIZE; tftp_set_request_blksize ( blksize ); snprintf ( uri_string, PXE_URI_LEN, "tftp://%s:%d%s%s", inet_ntoa ( address ), ntohs ( port ), ( ( filename[0] == '/' ) ? "" : "/" ), filename ); } /** * 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. * * Because we support arbitrary protocols, most of which have no * notion of "block size" and will return data in arbitrary-sized * chunks, we cheat and pretend to the caller that the blocksize is * always accepted as-is. * * 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 ) { char uri_string[PXE_URI_LEN]; DBG ( "PXENV_TFTP_OPEN" ); /* Guard against callers that fail to close before re-opening */ close ( pxe_single_fd ); pxe_single_fd = -1; /* Construct URI */ pxe_tftp_build_uri ( uri_string, tftp_open->ServerIPAddress, tftp_open->TFTPPort, tftp_open->FileName, tftp_open->PacketSize ); DBG ( " %s", uri_string ); /* Open URI */ pxe_single_fd = open ( uri_string ); if ( pxe_single_fd < 0 ) { tftp_open->Status = PXENV_STATUS ( pxe_single_fd ); return PXENV_EXIT_FAILURE; } /* Record parameters for later use */ pxe_single_blksize = tftp_open->PacketSize; pxe_single_blkidx = 0; tftp_open->Status = PXENV_STATUS_SUCCESS; return 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" ); close ( pxe_single_fd ); pxe_single_fd = -1; 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 ) { userptr_t buffer; ssize_t len; DBG ( "PXENV_TFTP_READ to %04x:%04x", tftp_read->Buffer.segment, tftp_read->Buffer.offset ); buffer = real_to_user ( tftp_read->Buffer.segment, tftp_read->Buffer.offset ); len = read_user ( pxe_single_fd, buffer, 0, pxe_single_blksize ); if ( len < 0 ) { tftp_read->Status = PXENV_STATUS ( len ); return PXENV_EXIT_FAILURE; } tftp_read->BufferSize = len; tftp_read->PacketNumber = ++pxe_single_blkidx; tftp_read->Status = PXENV_STATUS_SUCCESS; return 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 ) { char uri_string[PXE_URI_LEN]; int fd; userptr_t buffer; size_t max_len; ssize_t frag_len; size_t len = 0; int rc = -ENOBUFS; DBG ( "PXENV_TFTP_READ_FILE" ); /* Construct URI */ pxe_tftp_build_uri ( uri_string, tftp_read_file->ServerIPAddress, tftp_read_file->TFTPSrvPort, tftp_read_file->FileName, 0 ); DBG ( " %s", uri_string ); DBG ( " to %08lx+%lx", tftp_read_file->Buffer, tftp_read_file->BufferSize ); /* Open URI */ fd = open ( uri_string ); if ( fd < 0 ) { tftp_read_file->Status = PXENV_STATUS ( fd ); return PXENV_EXIT_FAILURE; } /* Read file */ buffer = phys_to_user ( tftp_read_file->Buffer ); max_len = tftp_read_file->BufferSize; while ( max_len ) { frag_len = read_user ( fd, buffer, len, max_len ); if ( frag_len <= 0 ) { rc = frag_len; break; } len += frag_len; max_len -= frag_len; } close ( fd ); tftp_read_file->BufferSize = len; 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 ) { char uri_string[PXE_URI_LEN]; int fd; ssize_t size; DBG ( "PXENV_TFTP_GET_FSIZE" ); /* Construct URI */ pxe_tftp_build_uri ( uri_string, tftp_get_fsize->ServerIPAddress, 0, tftp_get_fsize->FileName, 0 ); DBG ( " %s", uri_string ); /* Open URI */ fd = open ( uri_string ); if ( fd < 0 ) { tftp_get_fsize->Status = PXENV_STATUS ( fd ); return PXENV_EXIT_FAILURE; } /* Determine size */ size = fsize ( fd ); close ( fd ); if ( size < 0 ) { tftp_get_fsize->Status = PXENV_STATUS ( size ); return PXENV_EXIT_FAILURE; } tftp_get_fsize->FileSize = size; tftp_get_fsize->Status = PXENV_STATUS_SUCCESS; return PXENV_EXIT_SUCCESS; }