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authorLennart Poettering <lennart@poettering.net>2010-10-13 02:15:41 +0200
committerLennart Poettering <lennart@poettering.net>2010-10-13 02:15:41 +0200
commit52661efd21608dc7e0ac26b714a9254ed6180ddb (patch)
tree5f64764566711e6a38a664cfc0ee9f9a997e4857 /src/condition.c
parente04aad61bb5eff117e51631727a3ef2807c75d6b (diff)
unit: add minimal condition checker for unit startup
Diffstat (limited to 'src/condition.c')
-rw-r--r--src/condition.c158
1 files changed, 158 insertions, 0 deletions
diff --git a/src/condition.c b/src/condition.c
new file mode 100644
index 0000000000..8c2db2d3e9
--- /dev/null
+++ b/src/condition.c
@@ -0,0 +1,158 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+ This file is part of systemd.
+
+ Copyright 2010 ProFUSION embedded systems
+
+ 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>
+
+#include "util.h"
+#include "condition.h"
+
+Condition* condition_new(ConditionType type, const char *parameter, bool negate) {
+ Condition *c;
+
+ c = new0(Condition, 1);
+ c->type = type;
+ c->negate = negate;
+
+ 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;
+
+ 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;
+}
+
+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_KERNEL_COMMAND_LINE:
+ return !!test_kernel_command_line(c->parameter) == !c->negate;
+
+ default:
+ assert_not_reached("Invalid condition type.");
+ }
+}
+
+bool condition_test_list(Condition *first) {
+ Condition *c;
+
+ /* If the condition list is empty, then it is true */
+ if (!first)
+ return true;
+
+ /* Otherwise, if any of the conditions apply we return true */
+ LIST_FOREACH(conditions, c, first)
+ if (condition_test(c))
+ return true;
+
+ return false;
+}
+
+void condition_dump(Condition *c, FILE *f, const char *prefix) {
+ assert(c);
+ assert(f);
+
+ if (!prefix)
+ prefix = "";
+
+ fprintf(f,
+ "%s%s: %s%s\n",
+ prefix,
+ condition_type_to_string(c->type),
+ 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_KERNEL_COMMAND_LINE] = "ConditionKernelCommandLine",
+ [CONDITION_PATH_EXISTS] = "ConditionPathExists"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(condition_type, ConditionType);