Revert "smbd: make use of smbd_impersonate_{conn_vuid,conn_sess,root,guest}_create() wrappers"

This reverts commit 0dcaa0707bad67f7bfaa10ccaf167bfefbe87a0c.

See the discussion in

https://lists.samba.org/archive/samba-technical/2018-December/131731.html

for the reasoning behind this revert.

Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>

5 files changed, 9 insertions, 67 deletions

diff --git a/source3/modules/vfs_readonly.c b/source3/modules/vfs_readonly.c
index e7e12747a22..570eb7c4d15 100644
--- a/source3/modules/vfs_readonly.c
+++ b/source3/modules/vfs_readonly.c
@@ -84,7 +84,7 @@ static int readonly_connect(vfs_handle_struct *handle,
       for (i=0; i< VUID_CACHE_SIZE; i++) {
         struct vuid_cache_entry *ent = &conn->vuid_cache->array[i];
         ent->vuid = UID_FIELD_INVALID;
-        TALLOC_FREE(ent->user_ev_ctx);
+        ent->user_ev_ctx = NULL;
         TALLOC_FREE(ent->session_info);
         ent->read_only = false;
         ent->share_access = 0;
diff --git a/source3/smbd/conn.c b/source3/smbd/conn.c
index cfff6404608..3b9aaac7834 100644
--- a/source3/smbd/conn.c
+++ b/source3/smbd/conn.c
@@ -98,7 +98,7 @@ static void conn_clear_vuid_cache(connection_struct *conn, uint64_t vuid)
 			if (conn->user_ev_ctx == ent->user_ev_ctx) {
 				conn->user_ev_ctx = NULL;
 			}
-			TALLOC_FREE(ent->user_ev_ctx);
+			ent->user_ev_ctx = NULL;
 
 			/*
 			 * We need to keep conn->session_info around
diff --git a/source3/smbd/msdfs.c b/source3/smbd/msdfs.c
index 5283edbecfc..a5771646971 100644
--- a/source3/smbd/msdfs.c
+++ b/source3/smbd/msdfs.c
@@ -264,17 +264,8 @@ static NTSTATUS create_conn_struct_as_root(TALLOC_CTX *ctx,
 		return NT_STATUS_NO_MEMORY;
 	}
 
-	sconn->root_ev_ctx = smbd_impersonate_root_create(sconn->raw_ev_ctx);
-	if (sconn->root_ev_ctx == NULL) {
-		TALLOC_FREE(sconn);
-		return NT_STATUS_NO_MEMORY;
-	}
-	sconn->guest_ev_ctx = smbd_impersonate_guest_create(sconn->raw_ev_ctx);
-	if (sconn->guest_ev_ctx == NULL) {
-		TALLOC_FREE(sconn);
-		return NT_STATUS_NO_MEMORY;
-	}
-
+	sconn->root_ev_ctx = sconn->raw_ev_ctx;
+	sconn->guest_ev_ctx = sconn->raw_ev_ctx;
 	sconn->msg_ctx = msg;
 
 	conn = conn_new(sconn);
@@ -328,26 +319,7 @@ static NTSTATUS create_conn_struct_as_root(TALLOC_CTX *ctx,
 		vfs_user = get_current_username();
 	}
 
-	/*
-	 * The impersonation has to be done by the caller
-	 * of create_conn_struct_tos[_cwd]().
-	 *
-	 * Note: the context can't be changed anyway
-	 * as we're using our own tevent_context
-	 * and not a global one were other requests
-	 * could change the current unix token.
-	 *
-	 * We just use a wrapper tevent_context in order
-	 * to avoid crashes because TALLOC_FREE(conn->user_ev_ctx)
-	 * would also remove sconn->raw_ev_ctx.
-	 */
-	conn->user_ev_ctx = smbd_impersonate_debug_create(sconn->raw_ev_ctx,
-							  "FAKE impersonation",
-							  DBGLVL_DEBUG);
-	if (conn->user_ev_ctx == NULL) {
-		TALLOC_FREE(conn);
-		return NT_STATUS_NO_MEMORY;
-	}
+	conn->user_ev_ctx = sconn->raw_ev_ctx;
 
 	set_conn_connectpath(conn, connpath);
 
diff --git a/source3/smbd/process.c b/source3/smbd/process.c
index dc95af17393..a3571ee811a 100644
--- a/source3/smbd/process.c
+++ b/source3/smbd/process.c
@@ -3900,8 +3900,6 @@ void smbd_process(struct tevent_context *ev_ctx,
 		.ev = ev_ctx,
 		.frame = talloc_stackframe(),
 	};
-	struct tevent_context *root_ev_ctx = NULL;
-	struct tevent_context *guest_ev_ctx = NULL;
 	struct smbXsrv_client *client = NULL;
 	struct smbd_server_connection *sconn = NULL;
 	struct smbXsrv_connection *xconn = NULL;
@@ -3914,18 +3912,6 @@ void smbd_process(struct tevent_context *ev_ctx,
 	char *chroot_dir = NULL;
 	int rc;
 
-	root_ev_ctx = smbd_impersonate_root_create(ev_ctx);
-	if (root_ev_ctx == NULL) {
-		DEBUG(0,("smbd_impersonate_root_create() failed\n"));
-		exit_server_cleanly("smbd_impersonate_root_create().\n");
-	}
-
-	guest_ev_ctx = smbd_impersonate_guest_create(ev_ctx);
-	if (guest_ev_ctx == NULL) {
-		DEBUG(0,("smbd_impersonate_guest_create() failed\n"));
-		exit_server_cleanly("smbd_impersonate_guest_create().\n");
-	}
-
 	status = smbXsrv_client_create(ev_ctx, ev_ctx, msg_ctx, now, &client);
 	if (!NT_STATUS_IS_OK(status)) {
 		DBG_ERR("smbXsrv_client_create(): %s\n", nt_errstr(status));
@@ -3946,8 +3932,8 @@ void smbd_process(struct tevent_context *ev_ctx,
 	sconn->client = client;
 
 	sconn->raw_ev_ctx = ev_ctx;
-	sconn->root_ev_ctx = root_ev_ctx;
-	sconn->guest_ev_ctx = guest_ev_ctx;
+	sconn->root_ev_ctx = ev_ctx;
+	sconn->guest_ev_ctx = ev_ctx;
 	sconn->msg_ctx = msg_ctx;
 
 	ret = pthreadpool_tevent_init(sconn, lp_aio_max_threads(),
diff --git a/source3/smbd/uid.c b/source3/smbd/uid.c
index e7f0a8f620b..2ce5366b775 100644
--- a/source3/smbd/uid.c
+++ b/source3/smbd/uid.c
@@ -307,7 +307,7 @@ static void free_conn_session_info_if_unused(connection_struct *conn)
 		}
 	}
 	/* Not used, safe to free. */
-	TALLOC_FREE(conn->user_ev_ctx);
+	conn->user_ev_ctx = NULL;
 	TALLOC_FREE(conn->session_info);
 }
 
@@ -482,23 +482,7 @@ static bool check_user_ok(connection_struct *conn,
 		ent->session_info->unix_token->uid = sec_initial_uid();
 	}
 
-	if (vuid == UID_FIELD_INVALID) {
-		ent->user_ev_ctx = smbd_impersonate_conn_sess_create(
-			conn->sconn->raw_ev_ctx, conn, ent->session_info);
-		if (ent->user_ev_ctx == NULL) {
-			TALLOC_FREE(ent->session_info);
-			ent->vuid = UID_FIELD_INVALID;
-			return false;
-		}
-	} else {
-		ent->user_ev_ctx = smbd_impersonate_conn_vuid_create(
-			conn->sconn->raw_ev_ctx, conn, vuid);
-		if (ent->user_ev_ctx == NULL) {
-			TALLOC_FREE(ent->session_info);
-			ent->vuid = UID_FIELD_INVALID;
-			return false;
-		}
-	}
+	ent->user_ev_ctx = conn->sconn->raw_ev_ctx;
 
 	/*
 	 * It's actually OK to call check_user_ok() with