condition: split out most of condition handling into libsystemd-shard

The parts that require linknig to libcap, libselinux and friends stays in libsystemd-core.

2 files changed, 320 insertions, 0 deletions

diff --git a/src/shared/condition-util.c b/src/shared/condition-util.c
new file mode 100644
index 0000000000..d31c4bf5b1
--- /dev/null
+++ b/src/shared/condition-util.c
@@ -0,0 +1,243 @@
+/*-*- 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/statvfs.h>
+#include <fnmatch.h>
+
+#include <systemd/sd-id128.h>
+#include "util.h"
+#include "condition-util.h"
+#include "virt.h"
+#include "path-util.h"
+#include "fileio.h"
+#include "unit.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);
+}
+
+bool condition_test_kernel_command_line(Condition *c) {
+        char *line, *w, *state, *word = NULL;
+        bool equal;
+        int r;
+        size_t l, pl;
+        bool found = false;
+
+        assert(c);
+        assert(c->parameter);
+        assert(c->type == CONDITION_KERNEL_COMMAND_LINE);
+
+        r = proc_cmdline(&line);
+        if (r < 0)
+                log_warning("Failed to read /proc/cmdline, ignoring: %s", strerror(-r));
+        if (r <= 0)
+                return c->negate;
+
+        equal = !!strchr(c->parameter, '=');
+        pl = strlen(c->parameter);
+
+        FOREACH_WORD_QUOTED(w, l, line, state) {
+
+                free(word);
+                word = strndup(w, l);
+                if (!word)
+                        break;
+
+                if (equal) {
+                        if (streq(word, c->parameter)) {
+                                found = true;
+                                break;
+                        }
+                } else {
+                        if (startswith(word, c->parameter) && (word[pl] == '=' || word[pl] == 0)) {
+                                found = true;
+                                break;
+                        }
+                }
+
+        }
+
+        free(word);
+        free(line);
+
+        return found == !c->negate;
+}
+
+bool condition_test_virtualization(Condition *c) {
+        int b;
+        Virtualization v;
+        const char *id;
+
+        assert(c);
+        assert(c->parameter);
+        assert(c->type == CONDITION_VIRTUALIZATION);
+
+        v = detect_virtualization(&id);
+        if (v < 0) {
+                log_warning("Failed to detect virtualization, ignoring: %s", strerror(-v));
+                return c->negate;
+        }
+
+        /* First, compare with yes/no */
+        b = parse_boolean(c->parameter);
+
+        if (v > 0 && b > 0)
+                return !c->negate;
+
+        if (v == 0 && b == 0)
+                return !c->negate;
+
+        /* Then, compare categorization */
+        if (v == VIRTUALIZATION_VM && streq(c->parameter, "vm"))
+                return !c->negate;
+
+        if (v == VIRTUALIZATION_CONTAINER && streq(c->parameter, "container"))
+                return !c->negate;
+
+        /* Finally compare id */
+        return (v > 0 && streq(c->parameter, id)) == !c->negate;
+}
+
+bool condition_test_host(Condition *c) {
+        sd_id128_t x, y;
+        char *h;
+        int r;
+        bool b;
+
+        assert(c);
+        assert(c->parameter);
+        assert(c->type == CONDITION_HOST);
+
+        if (sd_id128_from_string(c->parameter, &x) >= 0) {
+
+                r = sd_id128_get_machine(&y);
+                if (r < 0)
+                        return c->negate;
+
+                return sd_id128_equal(x, y);
+        }
+
+        h = gethostname_malloc();
+        if (!h)
+                return c->negate;
+
+        b = fnmatch(c->parameter, h, FNM_CASEFOLD) == 0;
+        free(h);
+
+        return b == !c->negate;
+}
+
+bool condition_test_ac_power(Condition *c) {
+        int r;
+
+        assert(c);
+        assert(c->parameter);
+        assert(c->type == CONDITION_AC_POWER);
+
+        r = parse_boolean(c->parameter);
+        if (r < 0)
+                return !c->negate;
+
+        return ((on_ac_power() != 0) == !!r) == !c->negate;
+}
+
+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);
diff --git a/src/shared/condition-util.h b/src/shared/condition-util.h
new file mode 100644
index 0000000000..85d4d5bbfc
--- /dev/null
+++ b/src/shared/condition-util.h
@@ -0,0 +1,77 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#pragma once
+
+/***
+  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 <stdbool.h>
+#include <stdio.h>
+
+#include "list.h"
+#include "macro.h"
+
+typedef enum ConditionType {
+        CONDITION_PATH_EXISTS,
+        CONDITION_PATH_EXISTS_GLOB,
+        CONDITION_PATH_IS_DIRECTORY,
+        CONDITION_PATH_IS_SYMBOLIC_LINK,
+        CONDITION_PATH_IS_MOUNT_POINT,
+        CONDITION_PATH_IS_READ_WRITE,
+        CONDITION_DIRECTORY_NOT_EMPTY,
+        CONDITION_FILE_NOT_EMPTY,
+        CONDITION_FILE_IS_EXECUTABLE,
+        CONDITION_KERNEL_COMMAND_LINE,
+        CONDITION_VIRTUALIZATION,
+        CONDITION_SECURITY,
+        CONDITION_CAPABILITY,
+        CONDITION_HOST,
+        CONDITION_AC_POWER,
+        CONDITION_NULL,
+        _CONDITION_TYPE_MAX,
+        _CONDITION_TYPE_INVALID = -1
+} ConditionType;
+
+typedef struct Condition {
+        ConditionType type;
+
+        bool trigger:1;
+        bool negate:1;
+
+        char *parameter;
+
+        int state;
+
+        LIST_FIELDS(struct Condition, conditions);
+} Condition;
+
+Condition* condition_new(ConditionType type, const char *parameter, bool trigger, bool negate);
+void condition_free(Condition *c);
+void condition_free_list(Condition *c);
+
+bool condition_test_kernel_command_line(Condition *c);
+bool condition_test_virtualization(Condition *c);
+bool condition_test_host(Condition *c);
+bool condition_test_ac_power(Condition *c);
+
+void condition_dump(Condition *c, FILE *f, const char *prefix);
+void condition_dump_list(Condition *c, FILE *f, const char *prefix);
+
+const char* condition_type_to_string(ConditionType t) _const_;
+int condition_type_from_string(const char *s) _pure_;