/* 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 . */ #include #include #include #include #include #include #include #include #include GRUB_MOD_LICENSE ("GPLv3+"); /* A simple implementation for signed numbers. */ static int grub_strtosl (char *arg, char **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 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); }