[dm-devel] [PATCH 1/2] multipath.conf: add "enable_foreign" parameter
Martin Wilck
Martin.Wilck at suse.com
Thu Aug 15 14:46:54 UTC 2019
From: Martin Wilck <mwilck at suse.com>
This new configuration parameter can be used to selectively
enable foreign libraries. The value is a regular expression,
against which foreign library names such as "nvme" are matched.
By setting this to a value that matches no foreign library
(e.g. "^$" or "NONE"), foreign code is completely disabled.
By default, all available foreign libraries are loaded.
Signed-off-by: Martin Wilck <mwilck at suse.com>
---
libmultipath/config.h | 1 +
libmultipath/defaults.h | 2 ++
libmultipath/dict.c | 6 +++++
libmultipath/foreign.c | 53 +++++++++++++++++++++++++++++++++++++----
libmultipath/foreign.h | 3 ++-
multipath/main.c | 2 +-
multipathd/main.c | 2 +-
7 files changed, 62 insertions(+), 7 deletions(-)
diff --git a/libmultipath/config.h b/libmultipath/config.h
index ff2b4e86..36e99196 100644
--- a/libmultipath/config.h
+++ b/libmultipath/config.h
@@ -224,6 +224,7 @@ struct config {
vector elist_device;
vector elist_property;
vector elist_protocol;
+ char *enable_foreign;
};
extern struct udev * udev;
diff --git a/libmultipath/defaults.h b/libmultipath/defaults.h
index decc9335..4dfe007c 100644
--- a/libmultipath/defaults.h
+++ b/libmultipath/defaults.h
@@ -48,6 +48,8 @@
#define DEFAULT_FIND_MULTIPATHS_TIMEOUT -10
#define DEFAULT_UNKNOWN_FIND_MULTIPATHS_TIMEOUT 1
#define DEFAULT_ALL_TG_PT ALL_TG_PT_OFF
+/* Enable all foreign libraries by default */
+#define DEFAULT_ENABLE_FOREIGN ""
#define CHECKINT_UNDEF (~0U)
#define DEFAULT_CHECKINT 5
diff --git a/libmultipath/dict.c b/libmultipath/dict.c
index c6eba0f6..9f282c3f 100644
--- a/libmultipath/dict.c
+++ b/libmultipath/dict.c
@@ -610,6 +610,10 @@ declare_def_handler(find_multipaths_timeout, set_int)
declare_def_snprint_defint(find_multipaths_timeout, print_int,
DEFAULT_FIND_MULTIPATHS_TIMEOUT)
+declare_def_handler(enable_foreign, set_str)
+declare_def_snprint_defstr(enable_foreign, print_str,
+ DEFAULT_ENABLE_FOREIGN)
+
static int
def_config_dir_handler(struct config *conf, vector strvec)
{
@@ -1710,6 +1714,8 @@ init_keywords(vector keywords)
install_keyword("find_multipaths_timeout",
&def_find_multipaths_timeout_handler,
&snprint_def_find_multipaths_timeout);
+ install_keyword("enable_foreign", &def_enable_foreign_handler,
+ &snprint_def_enable_foreign);
__deprecated install_keyword("default_selector", &def_selector_handler, NULL);
__deprecated install_keyword("default_path_grouping_policy", &def_pgpolicy_handler, NULL);
__deprecated install_keyword("default_uid_attribute", &def_uid_attribute_handler, NULL);
diff --git a/libmultipath/foreign.c b/libmultipath/foreign.c
index 48e8d247..4b34e141 100644
--- a/libmultipath/foreign.c
+++ b/libmultipath/foreign.c
@@ -16,6 +16,7 @@
*/
#include <sys/sysmacros.h>
+#include <sys/types.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
@@ -25,6 +26,7 @@
#include <fnmatch.h>
#include <dlfcn.h>
#include <libudev.h>
+#include <regex.h>
#include "vector.h"
#include "debug.h"
#include "util.h"
@@ -111,17 +113,45 @@ static int select_foreign_libs(const struct dirent *di)
return fnmatch(foreign_pattern, di->d_name, FNM_FILE_NAME) == 0;
}
-static int _init_foreign(const char *multipath_dir)
+static void free_pre(void *arg)
+{
+ regex_t **pre = arg;
+
+ if (pre != NULL && *pre != NULL) {
+ regfree(*pre);
+ free(*pre);
+ *pre = NULL;
+ }
+}
+
+static int _init_foreign(const char *multipath_dir, const char *enable)
{
char pathbuf[PATH_MAX];
struct dirent **di;
struct scandir_result sr;
int r, i;
+ regex_t *enable_re = NULL;
foreigns = vector_alloc();
if (foreigns == NULL)
return -ENOMEM;
+ pthread_cleanup_push(free_pre, &enable_re);
+ enable_re = calloc(1, sizeof(*enable_re));
+ if (enable_re) {
+ const char *str = enable ? enable : DEFAULT_ENABLE_FOREIGN;
+
+ r = regcomp(enable_re, str, REG_EXTENDED|REG_NOSUB);
+ if (r != 0) {
+ char errbuf[64];
+
+ (void)regerror(r, enable_re, errbuf, sizeof(errbuf));
+ condlog (2, "%s: error compiling enable_foreign = \"%s\": \"%s\"",
+ __func__, str, errbuf);
+ free_pre(&enable_re);
+ }
+ }
+
r = scandir(multipath_dir, &di, select_foreign_libs, alphasort);
if (r == 0) {
@@ -163,6 +193,20 @@ static int _init_foreign(const char *multipath_dir)
memset(fgn, 0, sizeof(*fgn));
strlcpy((char*)fgn + offsetof(struct foreign, name), c, namesz);
+ if (enable_re != NULL) {
+ int ret = regexec(enable_re, fgn->name, 0, NULL, 0);
+
+ if (ret == REG_NOMATCH) {
+ condlog(3, "%s: foreign library \"%s\" is not enabled",
+ __func__, fgn->name);
+ free(fgn);
+ continue;
+ } else if (ret != 0)
+ /* assume it matches */
+ condlog(2, "%s: error %d in regexec() for %s",
+ __func__, ret, fgn->name);
+ }
+
snprintf(pathbuf, sizeof(pathbuf), "%s/%s", multipath_dir, fn);
fgn->handle = dlopen(pathbuf, RTLD_NOW|RTLD_LOCAL);
msg = dlerror();
@@ -205,11 +249,12 @@ static int _init_foreign(const char *multipath_dir)
dl_err:
free_foreign(fgn);
}
- pthread_cleanup_pop(1);
+ pthread_cleanup_pop(1); /* free_scandir_result */
+ pthread_cleanup_pop(1); /* free_pre */
return 0;
}
-int init_foreign(const char *multipath_dir)
+int init_foreign(const char *multipath_dir, const char *enable)
{
int ret;
@@ -222,7 +267,7 @@ int init_foreign(const char *multipath_dir)
}
pthread_cleanup_push(unlock_foreigns, NULL);
- ret = _init_foreign(multipath_dir);
+ ret = _init_foreign(multipath_dir, enable);
pthread_cleanup_pop(1);
return ret;
diff --git a/libmultipath/foreign.h b/libmultipath/foreign.h
index 697f12f8..acd33601 100644
--- a/libmultipath/foreign.h
+++ b/libmultipath/foreign.h
@@ -195,9 +195,10 @@ struct foreign {
* init_foreign(dir)
* load and initialize foreign multipath libraries in dir (libforeign-*.so).
* @param dir: directory to search
+ * @param enable: regex to match foreign library name ("*" above) against
* @returns: 0 on success, negative value on failure.
*/
-int init_foreign(const char *multipath_dir);
+int init_foreign(const char *multipath_dir, const char *enable);
/**
* cleanup_foreign(dir)
diff --git a/multipath/main.c b/multipath/main.c
index 96a11468..4f4d8e89 100644
--- a/multipath/main.c
+++ b/multipath/main.c
@@ -1050,7 +1050,7 @@ main (int argc, char *argv[])
goto out;
}
/* Failing here is non-fatal */
- init_foreign(conf->multipath_dir);
+ init_foreign(conf->multipath_dir, conf->enable_foreign);
if (cmd == CMD_USABLE_PATHS) {
r = check_usable_paths(conf, dev, dev_type) ?
RTVL_FAIL : RTVL_OK;
diff --git a/multipathd/main.c b/multipathd/main.c
index 7a5cd115..b5f08617 100644
--- a/multipathd/main.c
+++ b/multipathd/main.c
@@ -2848,7 +2848,7 @@ child (void * param)
}
/* Failing this is non-fatal */
- init_foreign(conf->multipath_dir);
+ init_foreign(conf->multipath_dir, conf->enable_foreign);
if (poll_dmevents)
poll_dmevents = dmevent_poll_supported();
--
2.22.0
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