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v1.20.1
src/image/script.c
427 строк
9 KB
Michael Brown
[legal] Relicense files under GPL2_OR_LATER_OR_UBDL
02 мар 2015, 17:17
02 мар 2015, 17:17
b6ee89f
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/* * Copyright (C) 2007 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., 51 Franklin Street, Fifth Floor, Boston, MA * 02110-1301, USA. * * You can also choose to distribute this program under the terms of * the Unmodified Binary Distribution Licence (as given in the file * COPYING.UBDL), provided that you have satisfied its requirements. */ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); /** * @file * * iPXE scripts * */ #include <string.h> #include <stdlib.h> #include <stdio.h> #include <ctype.h> #include <errno.h> #include <getopt.h> #include <ipxe/command.h> #include <ipxe/parseopt.h> #include <ipxe/image.h> #include <ipxe/shell.h> #include <usr/prompt.h> #include <ipxe/script.h> /** Offset within current script * * This is a global in order to allow goto_exec() to update the * offset. */ static size_t script_offset; /** * Process script lines * * @v image Script * @v process_line Line processor * @v terminate Termination check * @ret rc Return status code */ static int process_script ( struct image *image, int ( * process_line ) ( struct image *image, size_t offset, const char *label, const char *command ), int ( * terminate ) ( int rc ) ) { size_t len = 0; char *line = NULL; size_t line_offset; char *label; char *command; off_t eol; size_t frag_len; char *tmp; int rc; /* Initialise script and line offsets */ script_offset = 0; line_offset = 0; do { /* Find length of next line, excluding any terminating '\n' */ eol = memchr_user ( image->data, script_offset, '\n', ( image->len - script_offset ) ); if ( eol < 0 ) eol = image->len; frag_len = ( eol - script_offset ); /* Allocate buffer for line */ tmp = realloc ( line, ( len + frag_len + 1 /* NUL */ ) ); if ( ! tmp ) { rc = -ENOMEM; goto err_alloc; } line = tmp; /* Copy line */ copy_from_user ( ( line + len ), image->data, script_offset, frag_len ); len += frag_len; /* Move to next line in script */ script_offset += ( frag_len + 1 ); /* Strip trailing CR, if present */ if ( len && ( line[ len - 1 ] == '\r' ) ) len--; /* Handle backslash continuations */ if ( len && ( line[ len - 1 ] == '\\' ) ) { len--; rc = -EINVAL; continue; } /* Terminate line */ line[len] = '\0'; /* Split line into (optional) label and command */ command = line; while ( isspace ( *command ) ) command++; if ( *command == ':' ) { label = ++command; while ( *command && ! isspace ( *command ) ) command++; if ( *command ) *(command++) = '\0'; } else { label = NULL; } /* Process line */ rc = process_line ( image, line_offset, label, command ); if ( terminate ( rc ) ) goto err_process; /* Free line */ free ( line ); line = NULL; len = 0; /* Update line offset */ line_offset = script_offset; } while ( script_offset < image->len ); err_process: err_alloc: free ( line ); return rc; } /** * Terminate script processing on shell exit or command failure * * @v rc Line processing status * @ret terminate Terminate script processing */ static int terminate_on_exit_or_failure ( int rc ) { return ( shell_stopped ( SHELL_STOP_COMMAND_SEQUENCE ) || ( rc != 0 ) ); } /** * Execute script line * * @v image Script * @v offset Offset within script * @v label Label, or NULL * @v command Command * @ret rc Return status code */ static int script_exec_line ( struct image *image, size_t offset, const char *label __unused, const char *command ) { int rc; DBGC ( image, "[%04zx] $ %s\n", offset, command ); /* Execute command */ if ( ( rc = system ( command ) ) != 0 ) return rc; return 0; } /** * Execute script * * @v image Script * @ret rc Return status code */ static int script_exec ( struct image *image ) { size_t saved_offset; int rc; /* Temporarily de-register image, so that a "boot" command * doesn't throw us into an execution loop. */ unregister_image ( image ); /* Preserve state of any currently-running script */ saved_offset = script_offset; /* Process script */ rc = process_script ( image, script_exec_line, terminate_on_exit_or_failure ); /* Restore saved state */ script_offset = saved_offset; /* Re-register image (unless we have been replaced) */ if ( ! image->replacement ) register_image ( image ); return rc; } /** * Probe script image * * @v image Script * @ret rc Return status code */ static int script_probe ( struct image *image ) { static const char ipxe_magic[] = "#!ipxe"; static const char gpxe_magic[] = "#!gpxe"; linker_assert ( sizeof ( ipxe_magic ) == sizeof ( gpxe_magic ), magic_size_mismatch ); char test[ sizeof ( ipxe_magic ) - 1 /* NUL */ + 1 /* terminating space */]; /* Sanity check */ if ( image->len < sizeof ( test ) ) { DBGC ( image, "Too short to be a script\n" ); return -ENOEXEC; } /* Check for magic signature */ copy_from_user ( test, image->data, 0, sizeof ( test ) ); if ( ! ( ( ( memcmp ( test, ipxe_magic, sizeof ( test ) - 1 ) == 0 ) || ( memcmp ( test, gpxe_magic, sizeof ( test ) - 1 ) == 0 )) && isspace ( test[ sizeof ( test ) - 1 ] ) ) ) { DBGC ( image, "Invalid magic signature\n" ); return -ENOEXEC; } return 0; } /** Script image type */ struct image_type script_image_type __image_type ( PROBE_NORMAL ) = { .name = "script", .probe = script_probe, .exec = script_exec, }; /** "goto" options */ struct goto_options {}; /** "goto" option list */ static struct option_descriptor goto_opts[] = {}; /** "goto" command descriptor */ static struct command_descriptor goto_cmd = COMMAND_DESC ( struct goto_options, goto_opts, 1, 1, "<label>" ); /** * Current "goto" label * * Valid only during goto_exec(). Consider this part of a closure. */ static const char *goto_label; /** * Check for presence of label * * @v image Script * @v offset Offset within script * @v label Label * @v command Command * @ret rc Return status code */ static int goto_find_label ( struct image *image, size_t offset, const char *label, const char *command __unused ) { /* Check label exists */ if ( ! label ) return -ENOENT; /* Check label matches */ if ( strcmp ( goto_label, label ) != 0 ) return -ENOENT; /* Update script offset */ script_offset = offset; DBGC ( image, "[%04zx] Gone to :%s\n", offset, label ); return 0; } /** * Terminate script processing when label is found * * @v rc Line processing status * @ret terminate Terminate script processing */ static int terminate_on_label_found ( int rc ) { return ( rc == 0 ); } /** * "goto" command * * @v argc Argument count * @v argv Argument list * @ret rc Return status code */ static int goto_exec ( int argc, char **argv ) { struct goto_options opts; size_t saved_offset; int rc; /* Parse options */ if ( ( rc = parse_options ( argc, argv, &goto_cmd, &opts ) ) != 0 ) return rc; /* Sanity check */ if ( ! current_image ) { rc = -ENOTTY; printf ( "Not in a script: %s\n", strerror ( rc ) ); return rc; } /* Parse label */ goto_label = argv[optind]; /* Find label */ saved_offset = script_offset; if ( ( rc = process_script ( current_image, goto_find_label, terminate_on_label_found ) ) != 0 ) { script_offset = saved_offset; DBGC ( current_image, "[%04zx] No such label :%s\n", script_offset, goto_label ); return rc; } /* Terminate processing of current command */ shell_stop ( SHELL_STOP_COMMAND ); return 0; } /** "goto" command */ struct command goto_command __command = { .name = "goto", .exec = goto_exec, }; /** "prompt" options */ struct prompt_options { /** Key to wait for */ unsigned int key; /** Timeout */ unsigned long timeout; }; /** "prompt" option list */ static struct option_descriptor prompt_opts[] = { OPTION_DESC ( "key", 'k', required_argument, struct prompt_options, key, parse_key ), OPTION_DESC ( "timeout", 't', required_argument, struct prompt_options, timeout, parse_timeout ), }; /** "prompt" command descriptor */ static struct command_descriptor prompt_cmd = COMMAND_DESC ( struct prompt_options, prompt_opts, 0, MAX_ARGUMENTS, "[<text>]" ); /** * "prompt" command * * @v argc Argument count * @v argv Argument list * @ret rc Return status code */ static int prompt_exec ( int argc, char **argv ) { struct prompt_options opts; char *text; int rc; /* Parse options */ if ( ( rc = parse_options ( argc, argv, &prompt_cmd, &opts ) ) != 0 ) goto err_parse; /* Parse prompt text */ text = concat_args ( &argv[optind] ); if ( ! text ) { rc = -ENOMEM; goto err_concat; } /* Display prompt and wait for key */ if ( ( rc = prompt ( text, opts.timeout, opts.key ) ) != 0 ) goto err_prompt; /* Free prompt text */ free ( text ); return 0; err_prompt: free ( text ); err_concat: err_parse: return rc; } /** "prompt" command */ struct command prompt_command __command = { .name = "prompt", .exec = prompt_exec, };