libcgroup: Introduce cgroup_basename and modify the functions to use it.

basename() is not safe as it modifies the pointers from time to time.

In order to prevent it, write a safe version of basename which uses basename
internally.

As a side effect, it also clears up the following warning,

api.c: In function ‘cgroup_find_matching_rule’:
api.c:2201: warning: passing argument 1 of ‘__xpg_basename’ discards qualifiers from pointer target type
/usr/include/libgen.h:35: note: expected ‘char *’ but argument is of type ‘const char *’
api.c:2201: warning: passing argument 1 of ‘__xpg_basename’ discards qualifiers from pointer target type
/usr/include/libgen.h:35: note: expected ‘char *’ but argument is of type ‘const char *’
api.c:2201: warning: passing argument 1 of ‘__xpg_basename’ discards qualifiers from pointer target type
/usr/include/libgen.h:35: note: expected ‘char *’ but argument is of type ‘const char *’
api.c:2201: warning: passing argument 1 of ‘__xpg_basename’ discards qualifiers from pointer target type
/usr/include/libgen.h:35: note: expected ‘char *’ but argument is of type ‘const char *’
api.c:2201: warning: passing argument 1 of ‘__xpg_basename’ discards qualifiers from pointer target type
/usr/include/libgen.h:35: note: expected ‘char *’ but argument is of type ‘const char *’
api.c:2201: warning: passing argument 1 of ‘__xpg_basename’ discards qualifiers from pointer target type
/usr/include/libgen.h:35: note: expected ‘char *’ but argument is of type ‘const char *’
api.c:2201: warning: passing argument 1 of ‘__xpg_basename’ discards qualifiers from pointer target type
/usr/include/libgen.h:35: note: expected ‘char *’ but argument is of type ‘const char *’
api.c:2201: warning: passing argument 1 of ‘__xpg_basename’ discards qualifiers from pointer target type
/usr/include/libgen.h:35: note: expected ‘char *’ but argument is of type ‘const char *’
api.c:2201: warning: passing argument 1 of ‘__xpg_basename’ discards qualifiers from pointer target type
/usr/include/libgen.h:35: note: expected ‘char *’ but argument is of type ‘const char *’
api.c:2201: warning: passing argument 1 of ‘__xpg_basename’ discards qualifiers from pointer target type
/usr/include/libgen.h:35: note: expected ‘char *’ but argument is of type ‘const char *’
api.c:2201: warning: passing argument 1 of ‘__xpg_basename’ discards qualifiers from pointer target type
/usr/include/libgen.h:35: note: expected ‘char *’ but argument is of type ‘const char *’
api.c:2201: warning: passing argument 1 of ‘__xpg_basename’ discards qualifiers from pointer target type
/usr/include/libgen.h:35: note: expected ‘char *’ but argument is of type ‘const char *’
api.c:2201: warning: passing argument 1 of ‘__xpg_basename’ discards qualifiers from pointer target type
/usr/include/libgen.h:35: note: expected ‘char *’ but argument is of type ‘const char *’
api.c:2201: warning: passing argument 1 of ‘__xpg_basename’ discards qualifiers from pointer target type
/usr/include/libgen.h:35: note: expected ‘char *’ but argument is of type ‘const char *’
api.c:2201: warning: passing argument 1 of ‘__xpg_basename’ discards qualifiers from pointer target type
/usr/include/libgen.h:35: note: expected ‘char *’ but argument is of type ‘const char *’
api.c:2201: warning: passing argument 1 of ‘__xpg_basename’ discards qualifiers from pointer target type
/usr/include/libgen.h:35: note: expected ‘char *’ but argument is of type ‘const char *’
api.c:2201: warning: passing argument 1 of ‘__xpg_basename’ discards qualifiers from pointer target type
/usr/include/libgen.h:35: note: expected ‘char *’ but argument is of type ‘const char *’
api.c:2201: warning: passing argument 1 of ‘__xpg_basename’ discards qualifiers from pointer target type
/usr/include/libgen.h:35: note: expected ‘char *’ but argument is of type ‘const char *’
api.c:2201: warning: passing argument 1 of ‘__xpg_basename’ discards qualifiers from pointer target type
/usr/include/libgen.h:35: note: expected ‘char *’ but argument is of type ‘const char *’
api.c:2201: warning: passing argument 1 of ‘__xpg_basename’ discards qualifiers from pointer target type
/usr/include/libgen.h:35: note: expected ‘char *’ but argument is of type ‘const char *’

Signed-off-by: Dhaval Giani <dhaval.giani@gmail.com>

diff --git a/src/api.c b/src/api.c
index 672243feb7f2a06e4607befa74a4495403180791..2d4cd21e42a2051f3e9edaf289b92d546e9e2b98 100644 (file)
--- a/src/api.c
+++ b/src/api.c
@@ -180,6 +180,26 @@ static int cg_chown_recursive(char **path, uid_t owner, gid_t group)
        return ret;
 }
 
+static char *cgroup_basename(const char *path)
+{
+       char *base;
+       char *tmp_string;
+
+       tmp_string = strdup(path);
+
+       if (!tmp_string)
+               return NULL;
+
+       base = strdup(basename(tmp_string));
+
+       if (!base)
+               return NULL;
+
+       free(tmp_string);
+
+       return base;
+}
+
 static int cgroup_test_subsys_mounted(const char *name)
 {
        int i;
@@ -494,6 +514,7 @@ static int cgroup_parse_rules(bool cache, uid_t muid,
                        if (!matched)
                                continue;
                        if (len_procname) {
+                               char *mproc_base;
                                /*
                                 * If there is a rule based on process name,
                                 * it should be matched with mprocname.
@@ -505,18 +526,16 @@ static int cgroup_parse_rules(bool cache, uid_t muid,
                                        continue;
                                }
 
-                               /*
-                                * FIXME: basename() modifies the
-                                * string and really shouldn't!
-                                **/
-
+                               mproc_base = cgroup_basename(mprocname);
                                if (strcmp(mprocname, procname) &&
-                                       strcmp(basename(mprocname), procname)) {
+                                       strcmp(mproc_base, procname)) {
                                        uid = CGRULE_INVALID;
                                        gid = CGRULE_INVALID;
                                        matched = false;
+                                       free(mproc_base);
                                        continue;
                                }
+                               free(mproc_base);
                        }
                }
 
@@ -2179,6 +2198,7 @@ static struct cgroup_rule *cgroup_find_matching_rule(uid_t uid,
 {
        /* Return value */
        struct cgroup_rule *ret = rl.head;
+       char *base = NULL;
 
        pthread_rwlock_wrlock(&rl_lock);
        while (ret) {
@@ -2194,17 +2214,20 @@ static struct cgroup_rule *cgroup_find_matching_rule(uid_t uid,
                        break;
                if (!strcmp(ret->procname, procname))
                        break;
-               /*
-                * FIXME: basename() modifies the string and really shouldn't!
-                **/
 
-               if (!strcmp(ret->procname, basename(procname)))
+               base = cgroup_basename(procname);
+               if (!strcmp(ret->procname, base))
                        /* Check a rule of basename. */
                        break;
                ret = ret->next;
+               free(base);
+               base = NULL;
        }
        pthread_rwlock_unlock(&rl_lock);
 
+       if (base)
+               free(base);
+
        return ret;
 }