diff options
Diffstat (limited to 'grub-core/commands/test.c')
| -rw-r--r-- | grub-core/commands/test.c | 455 |
1 files changed, 455 insertions, 0 deletions
diff --git a/grub-core/commands/test.c b/grub-core/commands/test.c new file mode 100644 index 0000000..62d3fb3 --- /dev/null +++ b/grub-core/commands/test.c @@ -0,0 +1,455 @@ +/* test.c -- The test command.. */ +/* + * GRUB -- GRand Unified Bootloader + * Copyright (C) 2005,2007,2009 Free Software Foundation, Inc. + * + * GRUB 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 3 of the License, or + * (at your option) any later version. + * + * GRUB 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 GRUB. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <grub/dl.h> +#include <grub/misc.h> +#include <grub/mm.h> +#include <grub/env.h> +#include <grub/fs.h> +#include <grub/device.h> +#include <grub/file.h> +#include <grub/command.h> +#include <grub/i18n.h> + +GRUB_MOD_LICENSE ("GPLv3+"); + +/* A simple implementation for signed numbers. */ +static int +grub_strtosl (char *arg, const char ** const end, int base) +{ + if (arg[0] == '-') + return -grub_strtoul (arg + 1, end, base); + return grub_strtoul (arg, end, base); +} + +/* Context for test_parse. */ +struct test_parse_ctx +{ + int invert; + int or, and; + int file_exists; + struct grub_dirhook_info file_info; + char *filename; +}; + +/* Take care of discarding and inverting. */ +static void +update_val (int val, struct test_parse_ctx *ctx) +{ + ctx->and = ctx->and && (ctx->invert ? ! val : val); + ctx->invert = 0; +} + +/* A hook for iterating directories. */ +static int +find_file (const char *cur_filename, const struct grub_dirhook_info *info, + void *data) +{ + struct test_parse_ctx *ctx = data; + + if ((info->case_insensitive ? grub_strcasecmp (cur_filename, ctx->filename) + : grub_strcmp (cur_filename, ctx->filename)) == 0) + { + ctx->file_info = *info; + ctx->file_exists = 1; + return 1; + } + return 0; +} + +/* Check if file exists and fetch its information. */ +static void +get_fileinfo (char *path, struct test_parse_ctx *ctx) +{ + char *pathname; + char *device_name; + grub_fs_t fs; + grub_device_t dev; + + ctx->file_exists = 0; + device_name = grub_file_get_device_name (path); + dev = grub_device_open (device_name); + if (! dev) + { + grub_free (device_name); + return; + } + + fs = grub_fs_probe (dev); + if (! fs) + { + grub_free (device_name); + grub_device_close (dev); + return; + } + + pathname = grub_strchr (path, ')'); + if (! pathname) + pathname = path; + else + pathname++; + + /* Remove trailing '/'. */ + while (*pathname && pathname[grub_strlen (pathname) - 1] == '/') + pathname[grub_strlen (pathname) - 1] = 0; + + /* Split into path and filename. */ + ctx->filename = grub_strrchr (pathname, '/'); + if (! ctx->filename) + { + path = grub_strdup ("/"); + ctx->filename = pathname; + } + else + { + ctx->filename++; + path = grub_strdup (pathname); + path[ctx->filename - pathname] = 0; + } + + /* It's the whole device. */ + if (! *pathname) + { + ctx->file_exists = 1; + grub_memset (&ctx->file_info, 0, sizeof (ctx->file_info)); + /* Root is always a directory. */ + ctx->file_info.dir = 1; + + /* Fetch writing time. */ + ctx->file_info.mtimeset = 0; + if (fs->fs_mtime) + { + if (! fs->fs_mtime (dev, &ctx->file_info.mtime)) + ctx->file_info.mtimeset = 1; + grub_errno = GRUB_ERR_NONE; + } + } + else + (fs->fs_dir) (dev, path, find_file, ctx); + + grub_device_close (dev); + grub_free (path); + grub_free (device_name); +} + +/* Parse a test expression starting from *argn. */ +static int +test_parse (char **args, int *argn, int argc) +{ + struct test_parse_ctx ctx = { + .and = 1, + .or = 0, + .invert = 0 + }; + + /* Here we have the real parsing. */ + while (*argn < argc) + { + /* First try 3 argument tests. */ + if (*argn + 2 < argc) + { + /* String tests. */ + if (grub_strcmp (args[*argn + 1], "=") == 0 + || grub_strcmp (args[*argn + 1], "==") == 0) + { + update_val (grub_strcmp (args[*argn], args[*argn + 2]) == 0, + &ctx); + (*argn) += 3; + continue; + } + + if (grub_strcmp (args[*argn + 1], "!=") == 0) + { + update_val (grub_strcmp (args[*argn], args[*argn + 2]) != 0, + &ctx); + (*argn) += 3; + continue; + } + + /* GRUB extension: lexicographical sorting. */ + if (grub_strcmp (args[*argn + 1], "<") == 0) + { + update_val (grub_strcmp (args[*argn], args[*argn + 2]) < 0, + &ctx); + (*argn) += 3; + continue; + } + + if (grub_strcmp (args[*argn + 1], "<=") == 0) + { + update_val (grub_strcmp (args[*argn], args[*argn + 2]) <= 0, + &ctx); + (*argn) += 3; + continue; + } + + if (grub_strcmp (args[*argn + 1], ">") == 0) + { + update_val (grub_strcmp (args[*argn], args[*argn + 2]) > 0, + &ctx); + (*argn) += 3; + continue; + } + + if (grub_strcmp (args[*argn + 1], ">=") == 0) + { + update_val (grub_strcmp (args[*argn], args[*argn + 2]) >= 0, + &ctx); + (*argn) += 3; + continue; + } + + /* Number tests. */ + if (grub_strcmp (args[*argn + 1], "-eq") == 0) + { + update_val (grub_strtosl (args[*argn], 0, 0) + == grub_strtosl (args[*argn + 2], 0, 0), &ctx); + (*argn) += 3; + continue; + } + + if (grub_strcmp (args[*argn + 1], "-ge") == 0) + { + update_val (grub_strtosl (args[*argn], 0, 0) + >= grub_strtosl (args[*argn + 2], 0, 0), &ctx); + (*argn) += 3; + continue; + } + + if (grub_strcmp (args[*argn + 1], "-gt") == 0) + { + update_val (grub_strtosl (args[*argn], 0, 0) + > grub_strtosl (args[*argn + 2], 0, 0), &ctx); + (*argn) += 3; + continue; + } + + if (grub_strcmp (args[*argn + 1], "-le") == 0) + { + update_val (grub_strtosl (args[*argn], 0, 0) + <= grub_strtosl (args[*argn + 2], 0, 0), &ctx); + (*argn) += 3; + continue; + } + + if (grub_strcmp (args[*argn + 1], "-lt") == 0) + { + update_val (grub_strtosl (args[*argn], 0, 0) + < grub_strtosl (args[*argn + 2], 0, 0), &ctx); + (*argn) += 3; + continue; + } + + if (grub_strcmp (args[*argn + 1], "-ne") == 0) + { + update_val (grub_strtosl (args[*argn], 0, 0) + != grub_strtosl (args[*argn + 2], 0, 0), &ctx); + (*argn) += 3; + continue; + } + + /* GRUB extension: compare numbers skipping prefixes. + Useful for comparing versions. E.g. vmlinuz-2 -plt vmlinuz-11. */ + if (grub_strcmp (args[*argn + 1], "-pgt") == 0 + || grub_strcmp (args[*argn + 1], "-plt") == 0) + { + int i; + /* Skip common prefix. */ + for (i = 0; args[*argn][i] == args[*argn + 2][i] + && args[*argn][i]; i++); + + /* Go the digits back. */ + i--; + while (grub_isdigit (args[*argn][i]) && i > 0) + i--; + i++; + + if (grub_strcmp (args[*argn + 1], "-pgt") == 0) + update_val (grub_strtoul (args[*argn] + i, 0, 0) + > grub_strtoul (args[*argn + 2] + i, 0, 0), &ctx); + else + update_val (grub_strtoul (args[*argn] + i, 0, 0) + < grub_strtoul (args[*argn + 2] + i, 0, 0), &ctx); + (*argn) += 3; + continue; + } + + /* -nt and -ot tests. GRUB extension: when doing -?t<bias> bias + will be added to the first mtime. */ + if (grub_memcmp (args[*argn + 1], "-nt", 3) == 0 + || grub_memcmp (args[*argn + 1], "-ot", 3) == 0) + { + struct grub_dirhook_info file1; + int file1exists; + int bias = 0; + + /* Fetch fileinfo. */ + get_fileinfo (args[*argn], &ctx); + file1 = ctx.file_info; + file1exists = ctx.file_exists; + get_fileinfo (args[*argn + 2], &ctx); + + if (args[*argn + 1][3]) + bias = grub_strtosl (args[*argn + 1] + 3, 0, 0); + + if (grub_memcmp (args[*argn + 1], "-nt", 3) == 0) + update_val ((file1exists && ! ctx.file_exists) + || (file1.mtimeset && ctx.file_info.mtimeset + && file1.mtime + bias > ctx.file_info.mtime), + &ctx); + else + update_val ((! file1exists && ctx.file_exists) + || (file1.mtimeset && ctx.file_info.mtimeset + && file1.mtime + bias < ctx.file_info.mtime), + &ctx); + (*argn) += 3; + continue; + } + } + + /* Two-argument tests. */ + if (*argn + 1 < argc) + { + /* File tests. */ + if (grub_strcmp (args[*argn], "-d") == 0) + { + get_fileinfo (args[*argn + 1], &ctx); + update_val (ctx.file_exists && ctx.file_info.dir, &ctx); + (*argn) += 2; + continue; + } + + if (grub_strcmp (args[*argn], "-e") == 0) + { + get_fileinfo (args[*argn + 1], &ctx); + update_val (ctx.file_exists, &ctx); + (*argn) += 2; + continue; + } + + if (grub_strcmp (args[*argn], "-f") == 0) + { + get_fileinfo (args[*argn + 1], &ctx); + /* FIXME: check for other types. */ + update_val (ctx.file_exists && ! ctx.file_info.dir, &ctx); + (*argn) += 2; + continue; + } + + if (grub_strcmp (args[*argn], "-s") == 0) + { + grub_file_t file; + file = grub_file_open (args[*argn + 1], GRUB_FILE_TYPE_GET_SIZE + | GRUB_FILE_TYPE_NO_DECOMPRESS); + update_val (file && (grub_file_size (file) != 0), &ctx); + if (file) + grub_file_close (file); + grub_errno = GRUB_ERR_NONE; + (*argn) += 2; + continue; + } + + /* String tests. */ + if (grub_strcmp (args[*argn], "-n") == 0) + { + update_val (args[*argn + 1][0], &ctx); + + (*argn) += 2; + continue; + } + if (grub_strcmp (args[*argn], "-z") == 0) + { + update_val (! args[*argn + 1][0], &ctx); + (*argn) += 2; + continue; + } + } + + /* Special modifiers. */ + + /* End of expression. return to parent. */ + if (grub_strcmp (args[*argn], ")") == 0) + { + (*argn)++; + return ctx.or || ctx.and; + } + /* Recursively invoke if parenthesis. */ + if (grub_strcmp (args[*argn], "(") == 0) + { + (*argn)++; + update_val (test_parse (args, argn, argc), &ctx); + continue; + } + + if (grub_strcmp (args[*argn], "!") == 0) + { + ctx.invert = ! ctx.invert; + (*argn)++; + continue; + } + if (grub_strcmp (args[*argn], "-a") == 0) + { + (*argn)++; + continue; + } + if (grub_strcmp (args[*argn], "-o") == 0) + { + ctx.or = ctx.or || ctx.and; + ctx.and = 1; + (*argn)++; + continue; + } + + /* No test found. Interpret if as just a string. */ + update_val (args[*argn][0], &ctx); + (*argn)++; + } + return ctx.or || ctx.and; +} + +static grub_err_t +grub_cmd_test (grub_command_t cmd __attribute__ ((unused)), + int argc, char **args) +{ + int argn = 0; + + if (argc >= 1 && grub_strcmp (args[argc - 1], "]") == 0) + argc--; + + return test_parse (args, &argn, argc) ? GRUB_ERR_NONE + : grub_error (GRUB_ERR_TEST_FAILURE, N_("false")); +} + +static grub_command_t cmd_1, cmd_2; + +GRUB_MOD_INIT(test) +{ + cmd_1 = grub_register_command ("[", grub_cmd_test, + N_("EXPRESSION ]"), N_("Evaluate an expression.")); + cmd_1->flags |= GRUB_COMMAND_FLAG_EXTRACTOR; + cmd_2 = grub_register_command ("test", grub_cmd_test, + N_("EXPRESSION"), N_("Evaluate an expression.")); + cmd_2->flags |= GRUB_COMMAND_FLAG_EXTRACTOR; +} + +GRUB_MOD_FINI(test) +{ + grub_unregister_command (cmd_1); + grub_unregister_command (cmd_2); +} |