xnu-3248.50.21.tar.gz

[apple/xnu.git] / bsd / kern / kern_credential.c

diff --git a/bsd/kern/kern_credential.c b/bsd/kern/kern_credential.c
index 0d2a07e02636ba788543ca7d68d4ca45f96444ac..0558ce4499be9acb0d3172f431e008ba1eec3786 100644 (file)
--- a/bsd/kern/kern_credential.c
+++ b/bsd/kern/kern_credential.c
@@ -2073,14 +2073,66 @@ static int      kauth_cred_cache_lookup(int from, int to, void *src, void *dst);
 
 #if CONFIG_EXT_RESOLVER == 0
 /*
- * If there's no resolver, short-circuit the kauth_cred_x2y() lookups.
+ * If there's no resolver, only support a subset of the kauth_cred_x2y() lookups.
  */
 static __inline int
-kauth_cred_cache_lookup(__unused int from, __unused int to,
-       __unused void *src, __unused void *dst)
+kauth_cred_cache_lookup(int from, int to, void *src, void *dst)
 {
-       return (EWOULDBLOCK);
-
+       /* NB: These must match the definitions used by Libinfo's mbr_identifier_translate(). */
+       static const uuid_t _user_compat_prefix = {0xff, 0xff, 0xee, 0xee, 0xdd, 0xdd, 0xcc, 0xcc, 0xbb, 0xbb, 0xaa, 0xaa, 0x00, 0x00, 0x00, 0x00};
+       static const uuid_t _group_compat_prefix = {0xab, 0xcd, 0xef, 0xab, 0xcd, 0xef, 0xab, 0xcd, 0xef, 0xab, 0xcd, 0xef, 0x00, 0x00, 0x00, 0x00};
+#define COMPAT_PREFIX_LEN      (sizeof(uuid_t) - sizeof(id_t))
+
+       assert(from != to);
+
+       switch (from) {
+       case KI_VALID_UID: {
+               id_t uid = htonl(*(id_t *)src);
+
+               if (to == KI_VALID_GUID) {
+                       uint8_t *uu = dst;
+                       memcpy(uu, _user_compat_prefix, sizeof(_user_compat_prefix));
+                       memcpy(&uu[COMPAT_PREFIX_LEN], &uid, sizeof(uid));
+                       return (0);
+               }
+               break;
+       }
+       case KI_VALID_GID: {
+               id_t gid = htonl(*(id_t *)src);
+
+               if (to == KI_VALID_GUID) {
+                       uint8_t *uu = dst;
+                       memcpy(uu, _group_compat_prefix, sizeof(_group_compat_prefix));
+                       memcpy(&uu[COMPAT_PREFIX_LEN], &gid, sizeof(gid));
+                       return (0);
+               }
+               break;
+       }
+       case KI_VALID_GUID: {
+               const uint8_t *uu = src;
+
+               if (to == KI_VALID_UID) {
+                       if (memcmp(uu, _user_compat_prefix, COMPAT_PREFIX_LEN) == 0) {
+                               id_t uid;
+                               memcpy(&uid, &uu[COMPAT_PREFIX_LEN], sizeof(uid));
+                               *(id_t *)dst = ntohl(uid);
+                               return (0);
+                       }
+               } else if (to == KI_VALID_GID) {
+                       if (memcmp(uu, _group_compat_prefix, COMPAT_PREFIX_LEN) == 0) {
+                               id_t gid;
+                               memcpy(&gid, &uu[COMPAT_PREFIX_LEN], sizeof(gid));
+                               *(id_t *)dst = ntohl(gid);
+                               return (0);
+                       }
+               }
+               break;
+       }
+       default:
+               /* NOT IMPLEMENTED */
+               break;
+       }
+       return (ENOENT);
 }
 #endif
 
@@ -3159,11 +3211,11 @@ kauth_cred_ismember_guid(__unused kauth_cred_t cred, guid_t *guidp, int *resultp
                *resultp = 1;
                break;
        default:
-#if CONFIG_EXT_RESOLVER
        {
-               struct kauth_identity ki;
                gid_t gid;
-#if 6603280
+#if CONFIG_EXT_RESOLVER
+               struct kauth_identity ki;
+
                /*
                 * Grovel the identity cache looking for this GUID.
                 * If we find it, and it is for a user record, return
@@ -3190,7 +3242,7 @@ kauth_cred_ismember_guid(__unused kauth_cred_t cred, guid_t *guidp, int *resultp
                                return (0);
                        }
                }
-#endif /* 6603280 */
+#endif /* CONFIG_EXT_RESOLVER */
                /*
                 * Attempt to translate the GUID to a GID.  Even if
                 * this fails, we will have primed the cache if it is
@@ -3207,13 +3259,12 @@ kauth_cred_ismember_guid(__unused kauth_cred_t cred, guid_t *guidp, int *resultp
                                error = 0;
                        }
                } else {
+#if CONFIG_EXT_RESOLVER
  do_check:
+#endif /* CONFIG_EXT_RESOLVER */
                        error = kauth_cred_ismember_gid(cred, gid, resultp);
                }
        }
-#else  /* CONFIG_EXT_RESOLVER */
-               error = ENOENT;
-#endif /* CONFIG_EXT_RESOLVER */
                break;
        }
        return(error);