/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** This file is part of systemd. Copyright 2010 Lennart Poettering systemd 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 (at your option) any later version. systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include <stdlib.h> #include <errno.h> #include <string.h> #include <unistd.h> #ifdef HAVE_SELINUX #include <selinux/selinux.h> #endif #include "util.h" #include "condition.h" Condition* condition_new(ConditionType type, const char *parameter, bool trigger, bool negate) { Condition *c; if (!(c = new0(Condition, 1))) return NULL; c->type = type; c->trigger = trigger; c->negate = negate; if (parameter) if (!(c->parameter = strdup(parameter))) { free(c); return NULL; } return c; } void condition_free(Condition *c) { assert(c); free(c->parameter); free(c); } void condition_free_list(Condition *first) { Condition *c, *n; LIST_FOREACH_SAFE(conditions, c, n, first) condition_free(c); } static bool test_kernel_command_line(const char *parameter) { char *line, *w, *state, *word = NULL; bool equal; int r; size_t l, pl; bool found = false; assert(parameter); if (detect_virtualization(NULL) > 0) return false; if ((r = read_one_line_file("/proc/cmdline", &line)) < 0) { log_warning("Failed to read /proc/cmdline, ignoring: %s", strerror(-r)); return false; } equal = !!strchr(parameter, '='); pl = strlen(parameter); FOREACH_WORD_QUOTED(w, l, line, state) { free(word); if (!(word = strndup(w, l))) break; if (equal) { if (streq(word, parameter)) { found = true; break; } } else { if (startswith(word, parameter) && (word[pl] == '=' || word[pl] == 0)) { found = true; break; } } } free(word); free(line); return found; } static bool test_virtualization(const char *parameter) { int r, b; const char *id; assert(parameter); if ((r = detect_virtualization(&id)) < 0) { log_warning("Failed to detect virtualization, ignoring: %s", strerror(-r)); return false; } b = parse_boolean(parameter); if (r > 0 && b > 0) return true; if (r == 0 && b == 0) return true; return streq(parameter, id); } static bool test_security(const char *parameter) { #ifdef HAVE_SELINUX if (streq(parameter, "selinux")) return is_selinux_enabled() > 0; #endif return false; } bool condition_test(Condition *c) { assert(c); switch(c->type) { case CONDITION_PATH_EXISTS: return (access(c->parameter, F_OK) >= 0) == !c->negate; case CONDITION_PATH_IS_DIRECTORY: { struct stat st; if (lstat(c->parameter, &st) < 0) return !c->negate; return S_ISDIR(st.st_mode) == !c->negate; } case CONDITION_DIRECTORY_NOT_EMPTY: { int k; k = dir_is_empty(c->parameter); return !(k == -ENOENT || k > 0) == !c->negate; } case CONDITION_KERNEL_COMMAND_LINE: return test_kernel_command_line(c->parameter) == !c->negate; case CONDITION_VIRTUALIZATION: return test_virtualization(c->parameter) == !c->negate; case CONDITION_SECURITY: return test_security(c->parameter) == !c->negate; case CONDITION_NULL: return !c->negate; default: assert_not_reached("Invalid condition type."); } } bool condition_test_list(Condition *first) { Condition *c; int triggered = -1; /* If the condition list is empty, then it is true */ if (!first) return true; /* Otherwise, if all of the non-trigger conditions apply and * if any of the trigger conditions apply (unless there are * none) we return true */ LIST_FOREACH(conditions, c, first) { bool b; b = condition_test(c); if (!c->trigger && !b) return false; if (c->trigger && triggered <= 0) triggered = b; } return triggered != 0; } void condition_dump(Condition *c, FILE *f, const char *prefix) { assert(c); assert(f); if (!prefix) prefix = ""; fprintf(f, "%s\t%s: %s%s%s\n", prefix, condition_type_to_string(c->type), c->trigger ? "|" : "", c->negate ? "!" : "", c->parameter); } void condition_dump_list(Condition *first, FILE *f, const char *prefix) { Condition *c; LIST_FOREACH(conditions, c, first) condition_dump(c, f, prefix); } static const char* const condition_type_table[_CONDITION_TYPE_MAX] = { [CONDITION_PATH_EXISTS] = "ConditionPathExists", [CONDITION_PATH_IS_DIRECTORY] = "ConditionPathIsDirectory", [CONDITION_DIRECTORY_NOT_EMPTY] = "ConditionDirectoryNotEmpty", [CONDITION_KERNEL_COMMAND_LINE] = "ConditionKernelCommandLine", [CONDITION_VIRTUALIZATION] = "ConditionVirtualization", [CONDITION_SECURITY] = "ConditionSecurity", [CONDITION_NULL] = "ConditionNull" }; DEFINE_STRING_TABLE_LOOKUP(condition_type, ConditionType);