chiark / gitweb /
Merge pull request #5 from elogind/dev_v227
[elogind.git] / src / shared / acl-util.c
index d1eb6f226876813b403e2520346e47722c44b8f2..44076d04c063509246f7ac9137db1c4d721db835 100644 (file)
@@ -3,7 +3,7 @@
 /***
   This file is part of systemd.
 
-  Copyright 2011 Lennart Poettering
+  Copyright 2011,2013 Lennart Poettering
 
   systemd is free software; you can redistribute it and/or modify it
   under the terms of the GNU Lesser General Public License as published by
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
-#include <assert.h>
-#include <sys/acl.h>
-#include <acl/libacl.h>
 #include <errno.h>
 #include <stdbool.h>
 
 #include "acl-util.h"
+#include "util.h"
+#include "strv.h"
 
 int acl_find_uid(acl_t acl, uid_t uid, acl_entry_t *entry) {
         acl_entry_t i;
-        int found;
+        int r;
 
         assert(acl);
         assert(entry);
 
-        for (found = acl_get_entry(acl, ACL_FIRST_ENTRY, &i);
-             found > 0;
-             found = acl_get_entry(acl, ACL_NEXT_ENTRY, &i)) {
+        for (r = acl_get_entry(acl, ACL_FIRST_ENTRY, &i);
+             r > 0;
+             r = acl_get_entry(acl, ACL_NEXT_ENTRY, &i)) {
 
                 acl_tag_t tag;
                 uid_t *u;
@@ -60,9 +59,342 @@ int acl_find_uid(acl_t acl, uid_t uid, acl_entry_t *entry) {
                         return 1;
                 }
         }
+        if (r < 0)
+                return -errno;
+
+        return 0;
+}
+
+/// UNNEEDED by elogind
+#if 0
+int calc_acl_mask_if_needed(acl_t *acl_p) {
+        acl_entry_t i;
+        int r;
+
+        assert(acl_p);
+
+        for (r = acl_get_entry(*acl_p, ACL_FIRST_ENTRY, &i);
+             r > 0;
+             r = acl_get_entry(*acl_p, ACL_NEXT_ENTRY, &i)) {
+                acl_tag_t tag;
+
+                if (acl_get_tag_type(i, &tag) < 0)
+                        return -errno;
+
+                if (tag == ACL_MASK)
+                        return 0;
+
+                if (IN_SET(tag, ACL_USER, ACL_GROUP)) {
+                        if (acl_calc_mask(acl_p) < 0)
+                                return -errno;
+
+                        return 1;
+                }
+        }
+        if (r < 0)
+                return -errno;
+
+        return 0;
+}
+
+int add_base_acls_if_needed(acl_t *acl_p, const char *path) {
+        acl_entry_t i;
+        int r;
+        bool have_user_obj = false, have_group_obj = false, have_other = false;
+        struct stat st;
+        _cleanup_(acl_freep) acl_t basic = NULL;
+
+        assert(acl_p);
+
+        for (r = acl_get_entry(*acl_p, ACL_FIRST_ENTRY, &i);
+             r > 0;
+             r = acl_get_entry(*acl_p, ACL_NEXT_ENTRY, &i)) {
+                acl_tag_t tag;
+
+                if (acl_get_tag_type(i, &tag) < 0)
+                        return -errno;
+
+                if (tag == ACL_USER_OBJ)
+                        have_user_obj = true;
+                else if (tag == ACL_GROUP_OBJ)
+                        have_group_obj = true;
+                else if (tag == ACL_OTHER)
+                        have_other = true;
+                if (have_user_obj && have_group_obj && have_other)
+                        return 0;
+        }
+        if (r < 0)
+                return -errno;
+
+        r = stat(path, &st);
+        if (r < 0)
+                return -errno;
+
+        basic = acl_from_mode(st.st_mode);
+        if (!basic)
+                return -errno;
+
+        for (r = acl_get_entry(basic, ACL_FIRST_ENTRY, &i);
+             r > 0;
+             r = acl_get_entry(basic, ACL_NEXT_ENTRY, &i)) {
+                acl_tag_t tag;
+                acl_entry_t dst;
+
+                if (acl_get_tag_type(i, &tag) < 0)
+                        return -errno;
+
+                if ((tag == ACL_USER_OBJ && have_user_obj) ||
+                    (tag == ACL_GROUP_OBJ && have_group_obj) ||
+                    (tag == ACL_OTHER && have_other))
+                        continue;
+
+                r = acl_create_entry(acl_p, &dst);
+                if (r < 0)
+                        return -errno;
+
+                r = acl_copy_entry(dst, i);
+                if (r < 0)
+                        return -errno;
+        }
+        if (r < 0)
+                return -errno;
+        return 0;
+}
+
+int acl_search_groups(const char *path, char ***ret_groups) {
+        _cleanup_strv_free_ char **g = NULL;
+        _cleanup_(acl_free) acl_t acl = NULL;
+        bool ret = false;
+        acl_entry_t entry;
+        int r;
+
+        assert(path);
+
+        acl = acl_get_file(path, ACL_TYPE_DEFAULT);
+        if (!acl)
+                return -errno;
+
+        r = acl_get_entry(acl, ACL_FIRST_ENTRY, &entry);
+        for (;;) {
+                _cleanup_(acl_free_gid_tpp) gid_t *gid = NULL;
+                acl_tag_t tag;
+
+                if (r < 0)
+                        return -errno;
+                if (r == 0)
+                        break;
+
+                if (acl_get_tag_type(entry, &tag) < 0)
+                        return -errno;
+
+                if (tag != ACL_GROUP)
+                        goto next;
+
+                gid = acl_get_qualifier(entry);
+                if (!gid)
+                        return -errno;
+
+                if (in_gid(*gid) > 0) {
+                        if (!ret_groups)
+                                return true;
+
+                        ret = true;
+                }
+
+                if (ret_groups) {
+                        char *name;
+
+                        name = gid_to_name(*gid);
+                        if (!name)
+                                return -ENOMEM;
+
+                        r = strv_consume(&g, name);
+                        if (r < 0)
+                                return r;
+                }
+
+        next:
+                r = acl_get_entry(acl, ACL_NEXT_ENTRY, &entry);
+        }
+
+        if (ret_groups) {
+                *ret_groups = g;
+                g = NULL;
+        }
+
+        return ret;
+}
+
+int parse_acl(const char *text, acl_t *acl_access, acl_t *acl_default, bool want_mask) {
+        _cleanup_free_ char **a = NULL, **d = NULL; /* strings are not be freed */
+        _cleanup_strv_free_ char **split;
+        char **entry;
+        int r = -EINVAL;
+        _cleanup_(acl_freep) acl_t a_acl = NULL, d_acl = NULL;
+
+        split = strv_split(text, ",");
+        if (!split)
+                return -ENOMEM;
+
+        STRV_FOREACH(entry, split) {
+                char *p;
+
+                p = startswith(*entry, "default:");
+                if (!p)
+                        p = startswith(*entry, "d:");
+
+                if (p)
+                        r = strv_push(&d, p);
+                else
+                        r = strv_push(&a, *entry);
+                if (r < 0)
+                        return r;
+        }
+
+        if (!strv_isempty(a)) {
+                _cleanup_free_ char *join;
+
+                join = strv_join(a, ",");
+                if (!join)
+                        return -ENOMEM;
+
+                a_acl = acl_from_text(join);
+                if (!a_acl)
+                        return -errno;
+
+                if (want_mask) {
+                        r = calc_acl_mask_if_needed(&a_acl);
+                        if (r < 0)
+                                return r;
+                }
+        }
+
+        if (!strv_isempty(d)) {
+                _cleanup_free_ char *join;
+
+                join = strv_join(d, ",");
+                if (!join)
+                        return -ENOMEM;
+
+                d_acl = acl_from_text(join);
+                if (!d_acl)
+                        return -errno;
+
+                if (want_mask) {
+                        r = calc_acl_mask_if_needed(&d_acl);
+                        if (r < 0)
+                                return r;
+                }
+        }
+
+        *acl_access = a_acl;
+        *acl_default = d_acl;
+        a_acl = d_acl = NULL;
+
+        return 0;
+}
+
+static int acl_entry_equal(acl_entry_t a, acl_entry_t b) {
+        acl_tag_t tag_a, tag_b;
+
+        if (acl_get_tag_type(a, &tag_a) < 0)
+                return -errno;
+
+        if (acl_get_tag_type(b, &tag_b) < 0)
+                return -errno;
 
-        if (found < 0)
+        if (tag_a != tag_b)
+                return false;
+
+        switch (tag_a) {
+        case ACL_USER_OBJ:
+        case ACL_GROUP_OBJ:
+        case ACL_MASK:
+        case ACL_OTHER:
+                /* can have only one of those */
+                return true;
+        case ACL_USER: {
+                _cleanup_(acl_free_uid_tpp) uid_t *uid_a = NULL, *uid_b = NULL;
+
+                uid_a = acl_get_qualifier(a);
+                if (!uid_a)
+                        return -errno;
+
+                uid_b = acl_get_qualifier(b);
+                if (!uid_b)
+                        return -errno;
+
+                return *uid_a == *uid_b;
+        }
+        case ACL_GROUP: {
+                _cleanup_(acl_free_gid_tpp) gid_t *gid_a = NULL, *gid_b = NULL;
+
+                gid_a = acl_get_qualifier(a);
+                if (!gid_a)
+                        return -errno;
+
+                gid_b = acl_get_qualifier(b);
+                if (!gid_b)
+                        return -errno;
+
+                return *gid_a == *gid_b;
+        }
+        default:
+                assert_not_reached("Unknown acl tag type");
+        }
+}
+
+static int find_acl_entry(acl_t acl, acl_entry_t entry, acl_entry_t *out) {
+        acl_entry_t i;
+        int r;
+
+        for (r = acl_get_entry(acl, ACL_FIRST_ENTRY, &i);
+             r > 0;
+             r = acl_get_entry(acl, ACL_NEXT_ENTRY, &i)) {
+
+                r = acl_entry_equal(i, entry);
+                if (r < 0)
+                        return r;
+                if (r > 0) {
+                        *out = i;
+                        return 1;
+                }
+        }
+        if (r < 0)
+                return -errno;
+        return 0;
+}
+
+int acls_for_file(const char *path, acl_type_t type, acl_t new, acl_t *acl) {
+        _cleanup_(acl_freep) acl_t old;
+        acl_entry_t i;
+        int r;
+
+        old = acl_get_file(path, type);
+        if (!old)
+                return -errno;
+
+        for (r = acl_get_entry(new, ACL_FIRST_ENTRY, &i);
+             r > 0;
+             r = acl_get_entry(new, ACL_NEXT_ENTRY, &i)) {
+
+                acl_entry_t j;
+
+                r = find_acl_entry(old, i, &j);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        if (acl_create_entry(&old, &j) < 0)
+                                return -errno;
+
+                if (acl_copy_entry(j, i) < 0)
+                        return -errno;
+        }
+        if (r < 0)
                 return -errno;
 
+        *acl = old;
+        old = NULL;
         return 0;
 }
+#endif // 0