chiark / gitweb /
acl-util: fix memleak
[elogind.git] / src / shared / acl-util.c
index 950f472..b99ecbb 100644 (file)
@@ -1,5 +1,3 @@
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
 /***
   This file is part of systemd.
 
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
-#include <assert.h>
 #include <errno.h>
 #include <stdbool.h>
 
 #include "acl-util.h"
-#include "util.h"
+#include "alloc-util.h"
+#include "string-util.h"
 #include "strv.h"
+#include "user-util.h"
+#include "util.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;
@@ -60,23 +60,23 @@ int acl_find_uid(acl_t acl, uid_t uid, acl_entry_t *entry) {
                         return 1;
                 }
         }
-
-        if (found < 0)
+        if (r < 0)
                 return -errno;
 
         return 0;
 }
 
+#if 0 /// UNNEEDED by elogind
 int calc_acl_mask_if_needed(acl_t *acl_p) {
         acl_entry_t i;
-        int found;
+        int r;
+        bool need = false;
 
         assert(acl_p);
 
-        for (found = acl_get_entry(*acl_p, ACL_FIRST_ENTRY, &i);
-             found > 0;
-             found = acl_get_entry(*acl_p, ACL_NEXT_ENTRY, &i)) {
-
+        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)
@@ -84,73 +84,148 @@ int calc_acl_mask_if_needed(acl_t *acl_p) {
 
                 if (tag == ACL_MASK)
                         return 0;
+
+                if (IN_SET(tag, ACL_USER, ACL_GROUP))
+                        need = true;
+        }
+        if (r < 0)
+                return -errno;
+
+        if (need && acl_calc_mask(acl_p) < 0)
+                return -errno;
+
+        return need;
+}
+
+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;
 
-        if (found < 0)
+        r = stat(path, &st);
+        if (r < 0)
                 return -errno;
 
-        if (acl_calc_mask(acl_p) < 0)
+        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 search_acl_groups(char*** dst, const char* path, bool* belong) {
-        acl_t acl;
+int acl_search_groups(const char *path, char ***ret_groups) {
+        _cleanup_strv_free_ char **g = NULL;
+        _cleanup_(acl_freep) acl_t acl = NULL;
+        bool ret = false;
+        acl_entry_t entry;
+        int r;
 
         assert(path);
-        assert(belong);
 
         acl = acl_get_file(path, ACL_TYPE_DEFAULT);
-        if (acl) {
-                acl_entry_t entry;
-                int r;
-
-                r = acl_get_entry(acl, ACL_FIRST_ENTRY, &entry);
-                while (r > 0) {
-                        acl_tag_t tag;
-                        gid_t *gid;
-                        char *name;
+        if (!acl)
+                return -errno;
 
-                        r = acl_get_tag_type(entry, &tag);
-                        if (r < 0)
-                                break;
+        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;
+                if (tag != ACL_GROUP)
+                        goto next;
 
-                        gid = acl_get_qualifier(entry);
-                        if (!gid)
-                                break;
+                gid = acl_get_qualifier(entry);
+                if (!gid)
+                        return -errno;
+
+                if (in_gid(*gid) > 0) {
+                        if (!ret_groups)
+                                return true;
 
-                        if (in_gid(*gid) > 0) {
-                                *belong = true;
-                                break;
-                        }
+                        ret = true;
+                }
+
+                if (ret_groups) {
+                        char *name;
 
                         name = gid_to_name(*gid);
-                        if (!name) {
-                                acl_free(acl);
-                                return log_oom();
-                        }
-
-                        r = strv_consume(dst, name);
-                        if (r < 0) {
-                                acl_free(acl);
-                                return log_oom();
-                        }
-
-                next:
-                        r = acl_get_entry(acl, ACL_NEXT_ENTRY, &entry);
+                        if (!name)
+                                return -ENOMEM;
+
+                        r = strv_consume(&g, name);
+                        if (r < 0)
+                                return r;
                 }
 
-                acl_free(acl);
+        next:
+                r = acl_get_entry(acl, ACL_NEXT_ENTRY, &entry);
         }
 
-        return 0;
+        if (ret_groups) {
+                *ret_groups = g;
+                g = NULL;
+        }
+
+        return ret;
 }
 
-int parse_acl(char *text, acl_t *acl_access, acl_t *acl_default, bool want_mask) {
+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;
@@ -159,7 +234,7 @@ int parse_acl(char *text, acl_t *acl_access, acl_t *acl_default, bool want_mask)
 
         split = strv_split(text, ",");
         if (!split)
-                return log_oom();
+                return -ENOMEM;
 
         STRV_FOREACH(entry, split) {
                 char *p;
@@ -172,9 +247,9 @@ int parse_acl(char *text, acl_t *acl_access, acl_t *acl_default, bool want_mask)
                         r = strv_push(&d, p);
                 else
                         r = strv_push(&a, *entry);
+                if (r < 0)
+                        return r;
         }
-        if (r < 0)
-                return r;
 
         if (!strv_isempty(a)) {
                 _cleanup_free_ char *join;
@@ -185,7 +260,7 @@ int parse_acl(char *text, acl_t *acl_access, acl_t *acl_default, bool want_mask)
 
                 a_acl = acl_from_text(join);
                 if (!a_acl)
-                        return -EINVAL;
+                        return -errno;
 
                 if (want_mask) {
                         r = calc_acl_mask_if_needed(&a_acl);
@@ -203,7 +278,7 @@ int parse_acl(char *text, acl_t *acl_access, acl_t *acl_default, bool want_mask)
 
                 d_acl = acl_from_text(join);
                 if (!d_acl)
-                        return -EINVAL;
+                        return -errno;
 
                 if (want_mask) {
                         r = calc_acl_mask_if_needed(&d_acl);
@@ -215,36 +290,142 @@ int parse_acl(char *text, acl_t *acl_access, acl_t *acl_default, bool want_mask)
         *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 (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 found, r;
+        int r;
 
         old = acl_get_file(path, type);
         if (!old)
                 return -errno;
 
-        for (found = acl_get_entry(new, ACL_FIRST_ENTRY, &i);
-             found > 0;
-             found = acl_get_entry(new, ACL_NEXT_ENTRY, &i)) {
+        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;
 
-                if (acl_create_entry(&old, &j) < 0)
-                        return -errno;
+                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;
         }
-
-        r = calc_acl_mask_if_needed(&old);
         if (r < 0)
-                return r;
+                return -errno;
 
         *acl = old;
         old = NULL;
         return 0;
 }
+
+int add_acls_for_user(int fd, uid_t uid) {
+        _cleanup_(acl_freep) acl_t acl = NULL;
+        acl_entry_t entry;
+        acl_permset_t permset;
+        int r;
+
+        acl = acl_get_fd(fd);
+        if (!acl)
+                return -errno;
+
+        r = acl_find_uid(acl, uid, &entry);
+        if (r <= 0) {
+                if (acl_create_entry(&acl, &entry) < 0 ||
+                    acl_set_tag_type(entry, ACL_USER) < 0 ||
+                    acl_set_qualifier(entry, &uid) < 0)
+                        return -errno;
+        }
+
+        /* We do not recalculate the mask unconditionally here,
+         * so that the fchmod() mask above stays intact. */
+        if (acl_get_permset(entry, &permset) < 0 ||
+            acl_add_perm(permset, ACL_READ) < 0)
+                return -errno;
+
+        r = calc_acl_mask_if_needed(&acl);
+        if (r < 0)
+                return r;
+
+        return acl_set_fd(fd, acl);
+}
+#endif // 0