[CRIU] [PATCH 2/4] Add support for configuration files
vkabatov at redhat.com
vkabatov at redhat.com
Mon May 22 08:00:15 PDT 2017
From: Veronika Kabatova <vkabatov at redhat.com>
Implementation changes for usage of simple configuration files. Before
parsing the command line options, either default configuration files
(/etc/criu.d/default.conf, $HOME/.criu.d/default.conf; in this order) are
parsed, or a specific config file passed by the user. Two new options are
introduced: "--config FILEPATH" option allows users to specify a single
configuration file they want to use; and "--no-default-config" option to
forbid the parsing of default configuration files. Both options are to be
passed only via the command line.
Usage of configuration files is not mandatory to keep backwards
compatibility. The implementation of this feature tries to be compatible
with command line usage -- the user should get the same results whether
he passes the options (in the right order of parsing) on command line or
writes them in config files. This allows the user to:
1) Override boolean options if needed
2) Specify partial configuration for options that are possible to pass
several times (e.g. "--external"), and pass the rest of the options
based on process runtime by command line
Configuration file syntax allows comments marked with '#' sign, the rest
of the line after '#' is ignored. The user can use one option per line
(with argument supplied on the same line if needed, divided with whitespace
characters), the options are the same as long options (without the "--"
prefix used on command line).
Configuration file example (syntax purposes only, doesn't make sense):
$ cat ~/.criu.d/default.conf
tcp-established
work-dir /home/<USERNAME>/criu/work_directory
extra # inline comment
no-restore-sibling
tree 111111
Signed-off-by: Veronika Kabatova <vkabatov at redhat.com>
---
criu/Makefile | 7 ++
criu/crtools.c | 203 ++++++++++++++++++++++++++++++++++++++++++++--
criu/include/cr_options.h | 7 ++
3 files changed, 209 insertions(+), 8 deletions(-)
diff --git a/criu/Makefile b/criu/Makefile
index b2c6633..8e1a803 100644
--- a/criu/Makefile
+++ b/criu/Makefile
@@ -15,6 +15,12 @@ ifeq ($(filter clean mrproper,$(MAKECMDGOALS)),)
endif
#
+# Configuration file paths
+CONFIG-DEFINES += -DGLOBAL_CONFIG_DIR='"/etc/criu.d/"'
+CONFIG-DEFINES += -DDEFAULT_CONFIG_FILENAME='"default.conf"'
+CONFIG-DEFINES += -DUSER_CONFIG_DIR='".criu.d/"'
+
+#
# General flags.
ccflags-y += -fno-strict-aliasing
ccflags-y += -iquote criu/include
@@ -24,6 +30,7 @@ ccflags-y += -iquote $(ARCH_DIR)/include
ccflags-y += -iquote .
ccflags-y += -I/usr/include/libnl3
ccflags-y += $(COMPEL_UAPI_INCLUDES)
+ccflags-y += $(CONFIG-DEFINES)
export ccflags-y
diff --git a/criu/crtools.c b/criu/crtools.c
index ab8e1b5..c4c5ebd 100644
--- a/criu/crtools.c
+++ b/criu/crtools.c
@@ -55,6 +55,8 @@
#include "../soccr/soccr.h"
struct cr_options opts;
+char **first_conf = NULL;
+char **second_conf = NULL;
void init_opts(void)
{
@@ -208,21 +210,178 @@ bool deprecated_ok(char *what)
return false;
}
-int main(int argc, char *argv[], char *envp[])
+bool is_default_config_forbidden(char *args[])
{
+ int i = 0;
+ while (args[i] != NULL) {
+ if (!strncmp(args[i], "--no-default-config", strlen("--no-default-config")))
+ return true;
+ i++;
+ }
+ return false;
+}
-#define BOOL_OPT(OPT_NAME, SAVE_TO) \
- {OPT_NAME, no_argument, SAVE_TO, true},\
- {"no-" OPT_NAME, no_argument, SAVE_TO, false}
+char * specific_config_passed(char *args[])
+{
+ int i = 0;
+ while (args[i]) {
+ if (!strncmp(args[i], "--config", strlen("--config"))) {
+ /* getopt takes next string as required argument automatically */
+ return args[i + 1];
+ } else if (strstr(args[i], "--config=") != NULL) {
+ return args[i] + strlen("--config=");
+ }
+ i++;
+ }
+ return NULL;
+}
+
+void free_array(char **to_free)
+{
+ if (to_free == NULL) return;
+ int i = 0;
+ while (to_free[i] != NULL) {
+ free(to_free[i]);
+ i++;
+ }
+ free(to_free);
+ to_free = NULL;
+}
+
+void free_confs()
+{
+ free_array(first_conf);
+ free_array(second_conf);
+}
+static int count_elements(char **to_count)
+{
+ int count = 0;
+ if (to_count != NULL)
+ while (to_count[count] != NULL)
+ count++;
+ return count;
+}
+
+char ** parse_config(char *filepath, bool is_default)
+{
+ FILE* configfile = fopen(filepath, "r");
+ if (!configfile) {
+ /* Nonexistent default config file is *NOT* an error */
+ if (!is_default)
+ pr_err("Can't access configuration file %s.\n", filepath);
+ return NULL;
+ }
+
+ int size = 10;
+ int elements_read = 0, len = 0;
+ bool was_newline = true;
+ char **configuration = xmalloc(size * sizeof(char *));
+ if (configuration == NULL) {
+ fclose(configfile);
+ return NULL;
+ }
+ /* Initialize first element, getopt ignores it */
+ configuration[0] = xmalloc((strlen("criu") + 1) * sizeof(char));
+ if (configuration[0] == NULL) {
+ fclose(configfile);
+ return NULL;
+ }
+ memcpy(configuration[0], "criu\0", strlen("criu") + 1);
+
+ while (fscanf(configfile, "%ms", &configuration[elements_read + 1]) == 1) {
+ if (configuration[elements_read + 1][0] == '#') {
+ fscanf(configfile, "%*[^\n]");
+ was_newline = true;
+ } else {
+ if (was_newline) {
+ len = strlen(configuration[elements_read + 1]);
+ char *tmp = xrealloc(configuration[elements_read + 1], len + strlen("--") + 1);
+ if (tmp == NULL) {
+ free_array(configuration);
+ fclose(configfile);
+ return NULL;
+ }
+ memmove(tmp + strlen("--"), tmp, len + 1);
+ memmove(tmp, "--", strlen("--"));
+ configuration[elements_read + 1] = tmp;
+ }
+ elements_read++;
+ was_newline = fgetc(configfile) == '\n' ? true : false;
+ }
+ if (elements_read == size) {
+ size *= 2;
+ char **tmp_conf = xrealloc(configuration, size * sizeof(char *));
+ if (tmp_conf == NULL) {
+ free_array(configuration);
+ fclose(configfile);
+ return NULL;
+ }
+ configuration = tmp_conf;
+ }
+ }
+ configuration[elements_read + 1] = NULL;
+
+ fclose(configfile);
+ return configuration;
+}
+
+int main(int argc, char *argv[], char *envp[])
+{
pid_t pid = 0, tree_id = 0;
int ret = -1;
bool usage_error = true;
bool has_exec_cmd = false;
bool has_sub_command;
- int opt, idx;
+ int opt = 0;
+ int idx;
+ int state = PARSING_FIRST;
int log_level = DEFAULT_LOGLEVEL;
char *imgs_dir = ".";
+
+ /* Check for --help / -h on commandline before parsing, otherwise
+ * the help message won't be displayed if there is an error in
+ * configuration file syntax. Checks are kept in parser in case of
+ * option being put in the configuration file itself.
+ */
+ int i;
+ for (i = 0; i < argc; i++) {
+ if ((!strncmp(argv[i], "--help", strlen("--help"))) ||
+ (!strncmp(argv[i], "-h", strlen("-h")))) {
+ usage_error = false;
+ goto usage;
+ }
+ }
+
+ if (atexit(free_confs)) {
+ pr_err("Unable to register cleanup function.\n");
+ return 1;
+ }
+ char *specific_conf = specific_config_passed(argv);
+ if ((specific_conf == NULL) && (!is_default_config_forbidden(argv))) {
+ first_conf = parse_config(GLOBAL_CONFIG_DIR DEFAULT_CONFIG_FILENAME, true);
+ char local_filepath[PATH_MAX + 1];
+ char *home_dir = getenv("HOME");
+ if (!home_dir) {
+ pr_info("Unable to get $HOME directory, local configuration file will not be used.");
+ } else {
+ snprintf(local_filepath, PATH_MAX, "%s/%s%s",
+ home_dir, USER_CONFIG_DIR, DEFAULT_CONFIG_FILENAME);
+ second_conf = parse_config(local_filepath, true);
+ }
+ } else if (specific_conf != NULL) {
+ first_conf = parse_config(specific_conf, false);
+ if (first_conf == NULL) {
+ return 1;
+ }
+ }
+ int first_count = count_elements(first_conf);
+ int second_count = count_elements(second_conf);
+
+#define BOOL_OPT(OPT_NAME, SAVE_TO) \
+ {OPT_NAME, no_argument, SAVE_TO, true},\
+ {"no-" OPT_NAME, no_argument, SAVE_TO, false}
+
static const char short_opts[] = "dSsRf:F:t:p:hcD:o:v::x::Vr:jJ:lW:L:M:";
static struct option long_opts[] = {
{ "tree", required_argument, 0, 't' },
@@ -295,6 +454,8 @@ int main(int argc, char *argv[], char *envp[])
{ "status-fd", required_argument, 0, 1088 },
BOOL_OPT("remote", &opts.remote),
{ "verbosity", optional_argument, 0, 'v' },
+ { "config", required_argument, 0, 1089},
+ { "no-default-config", no_argument, 0, 1090},
{ },
};
@@ -333,9 +494,30 @@ int main(int argc, char *argv[], char *envp[])
while (1) {
idx = -1;
- opt = getopt_long(argc, argv, short_opts, long_opts, &idx);
- if (opt == -1)
+
+ switch (state) {
+ case PARSING_FIRST:
+ opt = getopt_long(first_count, first_conf, short_opts, long_opts, &idx);
+ break;
+ case PARSING_SECOND:
+ opt = getopt_long(second_count, second_conf, short_opts, long_opts, &idx);
+ break;
+ case PARSING_ARGV:
+ opt = getopt_long(argc, argv, short_opts, long_opts, &idx);
+ break;
+ default:
break;
+ }
+
+ if (opt == -1) {
+ if (state < PARSING_ARGV) {
+ state++;
+ optind = 0;
+ continue;
+ } else {
+ break;
+ }
+ }
if (!opt)
continue;
@@ -429,7 +611,6 @@ int main(int argc, char *argv[], char *envp[])
case 1049:
if (add_script(optarg))
return 1;
-
break;
case 1051:
opts.addr = optarg;
@@ -576,6 +757,12 @@ int main(int argc, char *argv[], char *envp[])
return 1;
}
break;
+ case 1089:
+ pr_info("Using configuration file %s\n.", optarg);
+ break;
+ case 1090:
+ pr_info("Default configuration files disabled.\n");
+ break;
case 'V':
pr_msg("Version: %s\n", CRIU_VERSION);
if (strcmp(CRIU_GITID, "0"))
diff --git a/criu/include/cr_options.h b/criu/include/cr_options.h
index 94fc717..f56c064 100644
--- a/criu/include/cr_options.h
+++ b/criu/include/cr_options.h
@@ -128,4 +128,11 @@ extern struct cr_options opts;
extern void init_opts(void);
+/*
+ * Option parsing state constants (marking max. 2 configuration files and argv)
+ */
+#define PARSING_FIRST 1
+#define PARSING_SECOND 2
+#define PARSING_ARGV 3
+
#endif /* __CR_OPTIONS_H__ */
--
2.7.4
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