[apparmor] [PATCH 1/2] apparmor: add clearing the profile cache when inconsistent
Seth Arnold
seth.arnold at gmail.com
Mon Aug 13 22:53:43 UTC 2012
Looks great to me, thanks for the new test cases.
-----Original Message-----
From: John Johansen <john.johansen at canonical.com>
Sender: apparmor-bounces at lists.ubuntu.com
Date: Mon, 13 Aug 2012 14:06:12
To: <apparmor at lists.ubuntu.com>
Subject: [apparmor] [PATCH 1/2] apparmor: add clearing the profile cache
when inconsistent
Add the ability to clear out the binary profile cache. This removes the
need to have a separate script to handle the logic of checking and
removing the cache if it is out of date.
The parser already does all the checking to determine cache validity
so it makes sense to allow the parser to clear out inconsistent cache
when it has been instructed to update the cache.
Signed-off-by: John Johansen <john.johansen at canonical.com>
---
parser/parser_main.c | 167 ++++++++++++++++++++++++++++++++++++++++++-------
parser/tst/caching.sh | 33 +++++++++-
2 files changed, 177 insertions(+), 23 deletions(-)
diff --git a/parser/parser_main.c b/parser/parser_main.c
index f4b4640..474dc0a 100644
--- a/parser/parser_main.c
+++ b/parser/parser_main.c
@@ -24,6 +24,7 @@
#include <string.h>
#include <stdlib.h>
#include <stdarg.h>
+#include <stddef.h>
#include <getopt.h>
#include <errno.h>
#include <fcntl.h>
@@ -71,6 +72,8 @@ int show_cache = 0;
int skip_cache = 0;
int skip_read_cache = 0;
int write_cache = 0;
+int cond_clear_cache = 1; /* only applies if write is set */
+int force_clear_cache = 0; /* force clearing regargless of state */
int preprocess_only = 0;
int skip_mode_force = 0;
struct timespec mru_tstamp;
@@ -109,6 +112,8 @@ struct option long_options[] = {
{"skip-read-cache", 0, 0, 'T'},
{"write-cache", 0, 0, 'W'},
{"show-cache", 0, 0, 'k'},
+ {"skip-bad-cache", 0, 0, 129}, /* no short option */
+ {"purge-cache", 0, 0, 130}, /* no short option */
{"cache-loc", 1, 0, 'L'},
{"debug", 0, 0, 'd'},
{"dump", 1, 0, 'D'},
@@ -151,6 +156,8 @@ static void display_usage(char *command)
"-K, --skip-cache Do not attempt to load or save cached profiles\n"
"-T, --skip-read-cache Do not attempt to load cached profiles\n"
"-W, --write-cache Save cached profile (force with -T)\n"
+ " --skip-bad-cache Don't clear cache if out of sync\n"
+ " --purge-cache Clear cache regardless of its state\n"
"-L, --cache-loc n Set the location of the profile cache\n"
"-q, --quiet Don't emit warnings\n"
"-v, --verbose Show profile names as they load\n"
@@ -527,6 +534,12 @@ static int process_arg(int c, char *optarg)
case 'T':
skip_read_cache = 1;
break;
+ case 129:
+ cond_clear_cache = 0;
+ break;
+ case 130:
+ force_clear_cache = 1;
+ break;
case 'L':
cacheloc = strdup(optarg);
break;
@@ -1165,6 +1178,120 @@ out:
return retval;
}
+static int dir_for_each(const char *dname,
+ int (* callback)(const char *, struct dirent *,
+ struct stat *)) {
+ struct dirent *dirent, *ent;
+ char *path = NULL;
+ DIR *dir = NULL;
+ int error;
+
+ dirent = malloc(offsetof(struct dirent, d_name) +
+ pathconf(dname, _PC_NAME_MAX) + 1);
+ if (!dirent) {
+ PDEBUG(_("could not alloc dirent"));
+ return -1;
+ }
+
+ PDEBUG("Opened cache directory \"%s\"\n", dname);
+ if (!(dir = opendir(dname))) {
+ free(dirent);
+ PDEBUG(_("opendir failed '%s'"), dname);
+ return -1;
+ }
+
+ for (error = readdir_r(dir, dirent, &ent);
+ error == 0 && ent != NULL;
+ error = readdir_r(dir, dirent, &ent)) {
+ struct stat my_stat;
+
+ if (strcmp(dirent->d_name, ".") == 0 ||
+ strcmp(dirent->d_name, "..") == 0)
+ continue;
+
+ if (asprintf(&path, "%s/%s", dname, dirent->d_name) < 0)
+ {
+ PDEBUG(_("Memory allocation error."));
+ goto fail;
+ }
+
+ if (stat(path, &my_stat)) {
+ PDEBUG(_("stat failed for '%s'"), path);
+ goto fail;
+ }
+
+ if (callback(path, dirent, &my_stat)) {
+ PDEBUG(_("dir_for_each callback failed\n"));
+ goto fail;
+ }
+
+ free(path);
+ path = NULL;
+ }
+
+ free(dirent);
+ closedir(dir);
+ return error;
+
+fail:
+ error = errno;
+ free(dirent);
+ free(path);
+ closedir(dir);
+ errno = error;
+
+ return -1;
+}
+
+static int clear_cache_cb(const char *path, __unused struct dirent *dirent,
+ struct stat *ent_stat)
+{
+ /* remove regular files */
+ if (S_ISREG(ent_stat->st_mode))
+ return unlink(path);
+
+ /* do nothing with other file types */
+ return 0;
+}
+
+static int clear_cache_files(const char *path)
+{
+ char *cache;
+ int error;
+
+ if (asprintf(&cache, "%s/cache", path) == -1) {
+ perror("asprintf");
+ exit(1);
+ }
+
+ error = dir_for_each(cache, clear_cache_cb);
+
+ free(cache);
+
+ return error;
+}
+
+static int create_cache(const char *path, const char *features)
+{
+ FILE * f = NULL;
+
+ f = fopen(path, "w");
+ if (f) {
+ if (fwrite(features, strlen(features), 1, f) != 1 )
+ goto fail;
+
+ fclose(f);
+ }
+
+ return 0;
+fail:
+ if (show_cache)
+ PERROR("Cache write disabled: cannot create %s\n", path);
+ write_cache = 0;
+
+ return -1;
+}
+
static void setup_flags(void)
{
char *cache_features_path = NULL;
@@ -1203,30 +1330,23 @@ static void setup_flags(void)
get_flags_string(&cache_flags, cache_features_path);
if (cache_flags) {
if (strcmp(flags_string, cache_flags) != 0) {
- if (show_cache) PERROR("Cache read/write disabled: %s does not match %s\n", FLAGS_FILE, cache_features_path);
- write_cache = 0;
- skip_read_cache = 1;
+ if (write_cache && cond_clear_cache) {
+ if (clear_cache_files(basedir) ||
+ create_cache(cache_features_path,
+ flags_string)) {
+ skip_read_cache = 1;
+ }
+ } else {
+ if (show_cache)
+ PERROR("Cache read/write disabled: %s does not match %s\n", FLAGS_FILE, cache_features_path);
+ write_cache = 0;
+ skip_read_cache = 1;
+ }
}
free(cache_flags);
cache_flags = NULL;
- }
- else if (write_cache) {
- FILE * f = NULL;
- int failure = 0;
-
- f = fopen(cache_features_path, "w");
- if (!f) failure = 1;
- else {
- if (fwrite(flags_string, strlen(flags_string), 1, f) != 1 ) {
- failure = 1;
- }
- if (fclose(f) != 0) failure = 1;
- }
-
- if (failure) {
- if (show_cache) PERROR("Cache write disabled: cannot write to %s\n", cache_features_path);
- write_cache = 0;
- }
+ } else if (write_cache) {
+ create_cache(cache_features_path, flags_string);
}
free(cache_features_path);
@@ -1256,6 +1376,11 @@ int main(int argc, char *argv[])
return retval;
}
+ if (force_clear_cache) {
+ clear_cache_files(basedir);
+ exit(0);
+ }
+
/* Check to make sure there is an interface to load policy */
if (!(UNPRIVILEGED_OPS) && (subdomainbase == NULL) &&
(retval = find_subdomainfs_mountpoint())) {
diff --git a/parser/tst/caching.sh b/parser/tst/caching.sh
index ac265a9..7652012 100755
--- a/parser/tst/caching.sh
+++ b/parser/tst/caching.sh
@@ -93,12 +93,41 @@ echo -n "monkey" > $basedir/cache/.features
../apparmor_parser $ARGS -v -r $basedir/$profile | grep -q 'Replacement succeeded for' || { echo "FAIL"; exit 1; }
echo "ok"
-echo -n "Cache writing is skipped when features do not match cache: "
+echo -n "Cache writing is skipped when features do not match and not cleared: "
rm $basedir/cache/$profile
-../apparmor_parser $ARGS -v --write-cache -r $basedir/$profile | grep -q 'Replacement succeeded for' || { echo "FAIL"; exit 1; }
+../apparmor_parser $ARGS -v --write-cache --skip-bad-cache -r $basedir/$profile | grep -q 'Replacement succeeded for' || { echo "FAIL"; exit 1; }
[ -f $basedir/cache/$profile ] && echo "FAIL ($basedir/cache/$profile exists)" && exit 1
echo "ok"
+rm -f $basedir/cache/.features || true
+rm -f $basedir/cache/$profile || true
+echo -n "monkey" > $basedir/cache/.features
+echo -n "monkey" > $basedir/cache/$profile
+echo -n "monkey" > $basedir/cache/monkey
+../apparmor_parser $ARGS -v --write-cache -r $basedir/$profile | grep -q 'Replacement succeeded for' || { echo "Cache clear setup FAIL"; exit 1; }
+echo -n "Cache clear updates features: "
+echo -n "monkey" | diff -q $basedir/cache/.features - | grep -q 'differ' || { echo "FAIL"; exit 1; }
+echo "ok"
+echo -n "Cache clear writes updated profile: "
+echo -n "monkey" | diff -q $basedir/cache/$profile - | grep -q 'differ' || { echo "FAIL"; exit 1; }
+echo "ok"
+echo -n "Cache clear cleans out all files: "
+[ -f $basedir/cache/monkey ] && { echo "FAIL"; exit 1; }
+echo "ok"
+
+rm -f $basedir/cache/monkey
+rm -f $basedir/cache/.features || true
+rm -f $basedir/cache/$profile || true
+echo -n "monkey" > $basedir/cache/.features
+echo -n "monkey" > $basedir/cache/$profile
+echo -n "monkey" > $basedir/cache/monkey
+echo -n "Cache purge remove profiles unconditionally: "
+../apparmor_parser $ARGS -v --purge-cache -r $basedir/$profile || { echo "Cache clear setup FAIL"; exit 1; }
+[ -f $basedir/cache/.features ] && { echo "FAIL"; exit 1; }
+[ -f $basedir/cache/$profile ] && { echo "FAIL"; exit 1; }
+[ -f $basedir/cache/monkey ] && { echo "FAIL"; exit 1; }
+echo "ok"
+
echo -n "Profiles are cached when requested (again): "
rm -f $basedir/cache/.features || true
rm -f $basedir/cache/$profile || true
--
1.7.10.4
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