/*-*- 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 Lesser General Public License as published by the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details. You should have received a copy of the GNU Lesser 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> #include <sys/capability.h> #include <sys/statvfs.h> #include <fnmatch.h> #include <systemd/sd-id128.h> #include "util.h" #include "condition.h" #include "virt.h" #include "path-util.h" #include "fileio.h" #include "unit.h" #include "smack-util.h" #include "apparmor-util.h" #include "ima-util.h" #include "selinux-util.h" Condition* condition_new(ConditionType type, const char *parameter, bool trigger, bool negate) { Condition *c; assert(type < _CONDITION_TYPE_MAX); c = new0(Condition, 1); if (!c) return NULL; c->type = type; c->trigger = trigger; c->negate = negate; if (parameter) { c->parameter = strdup(parameter); if (!c->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); r = proc_cmdline(&line); if (r < 0) log_warning("Failed to read /proc/cmdline, ignoring: %s", strerror(-r)); if (r <= 0) return false; equal = !!strchr(parameter, '='); pl = strlen(parameter); FOREACH_WORD_QUOTED(w, l, line, state) { free(word); word = strndup(w, l); if (!word) 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 b; Virtualization v; const char *id; assert(parameter); v = detect_virtualization(&id); if (v < 0) { log_warning("Failed to detect virtualization, ignoring: %s", strerror(-v)); return false; } /* First, compare with yes/no */ b = parse_boolean(parameter); if (v > 0 && b > 0) return true; if (v == 0 && b == 0) return true; /* Then, compare categorization */ if (v == VIRTUALIZATION_VM && streq(parameter, "vm")) return true; if (v == VIRTUALIZATION_CONTAINER && streq(parameter, "container")) return true; /* Finally compare id */ return v > 0 && streq(parameter, id); } static bool test_security(const char *parameter) { if (streq(parameter, "selinux")) return use_selinux(); if (streq(parameter, "apparmor")) return use_apparmor(); if (streq(parameter, "ima")) return use_ima(); if (streq(parameter, "smack")) return use_smack(); return false; } static bool test_capability(const char *parameter) { cap_value_t value; FILE *f; char line[LINE_MAX]; unsigned long long capabilities = (unsigned long long) -1; /* If it's an invalid capability, we don't have it */ if (cap_from_name(parameter, &value) < 0) return false; /* If it's a valid capability we default to assume * that we have it */ f = fopen("/proc/self/status", "re"); if (!f) return true; while (fgets(line, sizeof(line), f)) { truncate_nl(line); if (startswith(line, "CapBnd:")) { (void) sscanf(line+7, "%llx", &capabilities); break; } } fclose(f); return !!(capabilities & (1ULL << value)); } static bool test_host(const char *parameter) { sd_id128_t x, y; char *h; int r; bool b; if (sd_id128_from_string(parameter, &x) >= 0) { r = sd_id128_get_machine(&y); if (r < 0) return false; return sd_id128_equal(x, y); } h = gethostname_malloc(); if (!h) return false; b = fnmatch(parameter, h, FNM_CASEFOLD) == 0; free(h); return b; } static bool test_ac_power(const char *parameter) { int r; r = parse_boolean(parameter); if (r < 0) return true; return (on_ac_power() != 0) == !!r; } static 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_EXISTS_GLOB: return (glob_exists(c->parameter) > 0) == !c->negate; case CONDITION_PATH_IS_DIRECTORY: { struct stat st; if (stat(c->parameter, &st) < 0) return c->negate; return S_ISDIR(st.st_mode) == !c->negate; } case CONDITION_PATH_IS_SYMBOLIC_LINK: { struct stat st; if (lstat(c->parameter, &st) < 0) return c->negate; return S_ISLNK(st.st_mode) == !c->negate; } case CONDITION_PATH_IS_MOUNT_POINT: return (path_is_mount_point(c->parameter, true) > 0) == !c->negate; case CONDITION_PATH_IS_READ_WRITE: return (path_is_read_only_fs(c->parameter) > 0) == c->negate; case CONDITION_DIRECTORY_NOT_EMPTY: { int k; k = dir_is_empty(c->parameter); return !(k == -ENOENT || k > 0) == !c->negate; } case CONDITION_FILE_NOT_EMPTY: { struct stat st; if (stat(c->parameter, &st) < 0) return c->negate; return (S_ISREG(st.st_mode) && st.st_size > 0) == !c->negate; } case CONDITION_FILE_IS_EXECUTABLE: { struct stat st; if (stat(c->parameter, &st) < 0) return c->negate; return (S_ISREG(st.st_mode) && (st.st_mode & 0111)) == !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_CAPABILITY: return test_capability(c->parameter) == !c->negate; case CONDITION_HOST: return test_host(c->parameter) == !c->negate; case CONDITION_AC_POWER: return test_ac_power(c->parameter) == !c->negate; case CONDITION_NULL: return !c->negate; default: assert_not_reached("Invalid condition type."); } } bool condition_test_list(const char *unit, 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 (unit) log_debug_unit(unit, "%s=%s%s%s %s for %s.", condition_type_to_string(c->type), c->trigger ? "|" : "", c->negate ? "!" : "", c->parameter, b ? "succeeded" : "failed", unit); c->state = b ? 1 : -1; 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 %s\n", prefix, condition_type_to_string(c->type), c->trigger ? "|" : "", c->negate ? "!" : "", c->parameter, c->state < 0 ? "failed" : c->state > 0 ? "succeeded" : "untested"); } 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_EXISTS_GLOB] = "ConditionPathExistsGlob", [CONDITION_PATH_IS_DIRECTORY] = "ConditionPathIsDirectory", [CONDITION_PATH_IS_SYMBOLIC_LINK] = "ConditionPathIsSymbolicLink", [CONDITION_PATH_IS_MOUNT_POINT] = "ConditionPathIsMountPoint", [CONDITION_PATH_IS_READ_WRITE] = "ConditionPathIsReadWrite", [CONDITION_DIRECTORY_NOT_EMPTY] = "ConditionDirectoryNotEmpty", [CONDITION_FILE_NOT_EMPTY] = "ConditionFileNotEmpty", [CONDITION_FILE_IS_EXECUTABLE] = "ConditionFileIsExecutable", [CONDITION_KERNEL_COMMAND_LINE] = "ConditionKernelCommandLine", [CONDITION_VIRTUALIZATION] = "ConditionVirtualization", [CONDITION_SECURITY] = "ConditionSecurity", [CONDITION_CAPABILITY] = "ConditionCapability", [CONDITION_HOST] = "ConditionHost", [CONDITION_AC_POWER] = "ConditionACPower", [CONDITION_NULL] = "ConditionNull" }; DEFINE_STRING_TABLE_LOOKUP(condition_type, ConditionType);