Merge branch 'lukeshu/error'HEADmain

1 files changed, 79 insertions, 66 deletions

diff --git a/lib9p/srv_include/lib9p/srv.h b/lib9p/srv_include/lib9p/srv.h
index 89dc986..ce82e59 100644
--- a/lib9p/srv_include/lib9p/srv.h
+++ b/lib9p/srv_include/lib9p/srv.h
@@ -17,6 +17,11 @@
 
 #include <lib9p/core.h>
 
+#ifndef CONFIG_9P_SRV_MAX_ERR_SIZE
+	#error config.h must define CONFIG_9P_SRV_MAX_ERR_SIZE
+#endif
+static_assert(CONFIG_9P_SRV_MAX_ERR_SIZE <= UINT16_MAX);
+
 /* context ********************************************************************/
 
 struct lib9p_srv_userid {
@@ -45,8 +50,7 @@ struct lib9p_srv_ctx {
 	struct _lib9p_srv_sess          *parent_sess;
 	lib9p_tag_t                      tag;
 	uint8_t                         *net_bytes;
-	_lib9p_srv_flush_ch_t            flush_ch;
-	bool                             flush_acknowledged;
+	_lib9p_srv_flush_ch_t            flush_ch; /* flushers for this req _read_ from here */
 	bool                             responded;
 	END_PRIVATE(LIB9P_SRV_H);
 };
@@ -55,20 +59,13 @@ struct lib9p_srv_ctx {
  * Return whether there is an outstanding Tflush or Tversion
  * cancellation of this request.  After becoming true, this may go
  * back to false if the Tflush itself is flushed.
+ *
+ * As a special case, returning E_POSIX_ECANCELED indicates that the
+ * flush has been observed, and a Rerror should not be sent ot the
+ * client.
  */
 bool lib9p_srv_flush_requested(struct lib9p_srv_ctx *ctx);
 
-/**
- * Acknowledge that the handler is responding to an outstanding flush;
- * a non-Rerror R-message will be elided in favor of Rflush/Rversion.
- * lib9p_srv_flush_requested() must be true; so do not cr_yield()
- * between checking lib9p_srv_flush_requested() and calling
- * lib9p_srv_acknowledge_flush().  These are separate calls to
- * facilitate cases where a flush merely truncates a call, instead of
- * totally canceling it.
- */
-void lib9p_srv_acknowledge_flush(struct lib9p_srv_ctx *ctx);
-
 /* version-independent stat ***************************************************/
 
 struct lib9p_srv_stat {
@@ -95,18 +92,22 @@ struct lib9p_srv_stat {
 	struct lib9p_s          extension;
 #endif
 };
+typedef struct lib9p_srv_stat lib9p_srv_stat;
+DECLARE_ERROR_OR(lib9p_srv_stat);
 
 void lib9p_srv_stat_assert(struct lib9p_srv_stat stat);
 
 /* interface definitions ******************************************************/
 
+typedef struct iovec iovec;
+DECLARE_ERROR_OR(iovec);
+
 struct lib9p_srv_dirent {
 	struct lib9p_qid        qid;
 	struct lib9p_s          name;
 };
-
-lo_interface lib9p_srv_fio;
-lo_interface lib9p_srv_dio;
+typedef struct lib9p_srv_dirent lib9p_srv_dirent;
+DECLARE_ERROR_OR(lib9p_srv_dirent);
 
 /* FIXME: I don't like that the pointer returned by pread() has to
  * remain live after it returns.  Perhaps a `respond()`-callback?  But
@@ -114,6 +115,46 @@ lo_interface lib9p_srv_dio;
  *
  * FIXME: It would be nice if pread() could return more than 1 iovec.
  */
+#define lib9p_srv_fio_LO_IFACE /*<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<*/ \
+	LO_FUNC(struct lib9p_qid           , qid    )                          \
+	LO_FUNC(void                       , iofree )                          \
+	LO_FUNC(uint32_t                   , iounit )                          \
+	LO_FUNC(iovec_or_error             , pread  , struct lib9p_srv_ctx *,  \
+	                                              uint32_t byte_count,     \
+	                                              uint64_t byte_offset)    \
+	/**                                                                    \
+	 * If the file was append-only when fopen()ed, then byte_offset will   \
+	 * always be 0.                                                        \
+	 */                                                                    \
+	LO_FUNC(uint32_t_or_error          , pwrite , struct lib9p_srv_ctx *,  \
+	                                              void *buf,               \
+	                                              uint32_t byte_count,     \
+	                                              uint64_t byte_offset)
+LO_INTERFACE(lib9p_srv_fio); /*>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>*/
+typedef lo_interface lib9p_srv_fio lib9p_srv_fio;
+DECLARE_ERROR_OR(lib9p_srv_fio);
+
+#define lib9p_srv_dio_LO_IFACE /*<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<*/ \
+	LO_FUNC(struct lib9p_qid           , qid    )                          \
+	LO_FUNC(void                       , iofree )                          \
+	/**                                                                    \
+	 * Return the idx-th dirent.  idx will always be either 0 or           \
+	 * prev_idx+1.  A dirent with an empty name signals EOF.  The string   \
+	 * must remain valid until the next dread() call or iofree().          \
+	 */                                                                    \
+	LO_FUNC(lib9p_srv_dirent_or_error  , dread  , struct lib9p_srv_ctx *,  \
+	                                              size_t idx)
+LO_INTERFACE(lib9p_srv_dio); /*>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>*/
+typedef lo_interface lib9p_srv_dio lib9p_srv_dio;
+DECLARE_ERROR_OR(lib9p_srv_dio);
+
+struct _lo_lib9p_srv_file_vtable;
+lo_interface lib9p_srv_file {
+	void *self;
+	const struct _lo_lib9p_srv_file_vtable *vtable;
+};
+typedef lo_interface lib9p_srv_file lib9p_srv_file;
+DECLARE_ERROR_OR(lib9p_srv_file);
 #define lib9p_srv_file_LO_IFACE /*<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<*/ \
 	/* resource management **********************************************/ \
 	                                                                       \
@@ -139,16 +180,16 @@ lo_interface lib9p_srv_dio;
 	/* non-"opened" generic I/O *****************************************/ \
 	                                                                       \
 	/** Strings returned from stat() must remain valid until free().  */   \
-	LO_FUNC(struct lib9p_srv_stat      , stat   , struct lib9p_srv_ctx *)  \
-	LO_FUNC(void                       , wstat  , struct lib9p_srv_ctx *,  \
+	LO_FUNC(lib9p_srv_stat_or_error    , stat   , struct lib9p_srv_ctx *)  \
+	LO_FUNC(error                      , wstat  , struct lib9p_srv_ctx *,  \
 	                                              struct lib9p_srv_stat)   \
-	LO_FUNC(void                       , remove , struct lib9p_srv_ctx *)  \
+	LO_FUNC(error                      , remove , struct lib9p_srv_ctx *)  \
 	                                                                       \
 	/* non-"opened" directory I/O ***************************************/ \
 	                                                                       \
-	LO_FUNC(lo_interface lib9p_srv_file, dwalk  , struct lib9p_srv_ctx *,         \
+	LO_FUNC(lib9p_srv_file_or_error    , dwalk  , struct lib9p_srv_ctx *,         \
 	                                              struct lib9p_s childname)       \
-	LO_FUNC(lo_interface lib9p_srv_file, dcreate, struct lib9p_srv_ctx *,         \
+	LO_FUNC(lib9p_srv_file_or_error    , dcreate, struct lib9p_srv_ctx *,         \
 	                                              struct lib9p_s childname,       \
 	                                              struct lib9p_srv_userid *user,  \
 	                                              struct lib9p_srv_userid *group, \
@@ -156,50 +197,22 @@ lo_interface lib9p_srv_dio;
 	                                                                       \
 	/* open() for I/O ***************************************************/ \
 	                                                                       \
-	LO_FUNC(lo_interface lib9p_srv_fio , fopen  , struct lib9p_srv_ctx *,  \
+	LO_FUNC(lib9p_srv_fio_or_error     , fopen  , struct lib9p_srv_ctx *,  \
 	                                              bool rd, bool wr,        \
 	                                              bool trunc)              \
-	LO_FUNC(lo_interface lib9p_srv_dio , dopen  , struct lib9p_srv_ctx *)
+	LO_FUNC(lib9p_srv_dio_or_error     , dopen  , struct lib9p_srv_ctx *)
 LO_INTERFACE(lib9p_srv_file); /*>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>*/
 
-#define lib9p_srv_fio_LO_IFACE /*<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<*/ \
-	LO_FUNC(struct lib9p_qid           , qid    )                          \
-	LO_FUNC(void                       , iofree )                          \
-	LO_FUNC(uint32_t                   , iounit )                          \
-	LO_FUNC(void                       , pread  , struct lib9p_srv_ctx *,  \
-	                                              uint32_t byte_count,     \
-	                                              uint64_t byte_offset,    \
-	                                              struct iovec *ret)       \
-	/**                                                                    \
-	 * If the file was append-only when fopen()ed, then byte_offset will   \
-	 * always be 0.                                                        \
-	 */                                                                    \
-	LO_FUNC(uint32_t                   , pwrite , struct lib9p_srv_ctx *,  \
-	                                              void *buf,               \
-	                                              uint32_t byte_count,     \
-	                                              uint64_t byte_offset)
-LO_INTERFACE(lib9p_srv_fio); /*>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>*/
-
-#define lib9p_srv_dio_LO_IFACE /*<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<*/ \
-	LO_FUNC(struct lib9p_qid           , qid    )                          \
-	LO_FUNC(void                       , iofree )                          \
-	/**                                                                    \
-	 * Return the idx-th dirent.  idx will always be either 0 or           \
-	 * prev_idx+1.  A dirent with an empty name signals EOF.  The string   \
-	 * must remain valid until the next dread() call or iofree().          \
-	 */                                                                    \
-	LO_FUNC(struct lib9p_srv_dirent    , dread  , struct lib9p_srv_ctx *,  \
-	                                              size_t idx)
-LO_INTERFACE(lib9p_srv_dio); /*>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>*/
-
 #define LIB9P_SRV_NOTDIR(TYP, NAM)                                                                                                                                   \
-	static lo_interface lib9p_srv_file NAM##_dwalk  (TYP *, struct lib9p_srv_ctx *, struct lib9p_s)                    { assert_notreached("not a directory"); } \
-	static lo_interface lib9p_srv_file NAM##_dcreate(TYP *, struct lib9p_srv_ctx *, struct lib9p_s,                                                              \
-	                                                 struct lib9p_srv_userid *, struct lib9p_srv_userid *, lib9p_dm_t) { assert_notreached("not a directory"); } \
-	static lo_interface lib9p_srv_dio  NAM##_dopen  (TYP *, struct lib9p_srv_ctx *)                                    { assert_notreached("not a directory"); }
+	static lib9p_srv_file_or_error NAM##_dwalk  (TYP *, struct lib9p_srv_ctx *, struct lib9p_s)                    { assert_notreached("not a directory"); } \
+	static lib9p_srv_file_or_error NAM##_dcreate(TYP *, struct lib9p_srv_ctx *, struct lib9p_s,                                                              \
+	                                             struct lib9p_srv_userid *, struct lib9p_srv_userid *, lib9p_dm_t) { assert_notreached("not a directory"); } \
+	static lib9p_srv_dio_or_error  NAM##_dopen  (TYP *, struct lib9p_srv_ctx *)                                    { assert_notreached("not a directory"); } \
+	LM_FORCE_SEMICOLON
 
 #define LIB9P_SRV_NOTFILE(TYP, NAM) \
-	static lo_interface lib9p_srv_fio  NAM##_fopen  (TYP *, struct lib9p_srv_ctx *, bool, bool, bool)                  { assert_notreached("not a file"); }
+	static lib9p_srv_fio_or_error  NAM##_fopen  (TYP *, struct lib9p_srv_ctx *, bool, bool, bool)                  { assert_notreached("not a file"); } \
+	LM_FORCE_SEMICOLON
 
 /* main server entrypoints ****************************************************/
 
@@ -215,9 +228,9 @@ LO_INTERFACE(net_stream_conn_unix);
 
 struct lib9p_srv {
 	/* Things you provide */
-	void /*TODO*/               (*auth   )(struct lib9p_srv_ctx *, struct lib9p_s treename); /* optional */
-	lo_interface lib9p_srv_file (*rootdir)(struct lib9p_srv_ctx *, struct lib9p_s treename);
-	void                        (*msglog )(struct lib9p_srv_ctx *, enum lib9p_msg_type, void *hostmsg); /* optional */
+	error /*TODO*/          (*auth   )(struct lib9p_srv_ctx *, struct lib9p_s treename); /* optional */
+	lib9p_srv_file_or_error (*rootdir)(struct lib9p_srv_ctx *, struct lib9p_s treename);
+	void                    (*msglog )(struct lib9p_srv_ctx *, enum lib9p_msg_type, void *hostmsg); /* optional */
 #if CONFIG_9P_ENABLE_9P2000_p9p
 	lo_interface net_stream_conn_unix (*type_assert_unix)(lo_interface net_stream_conn); /* optional */
 #endif
@@ -263,10 +276,10 @@ void lib9p_srv_accept_and_read_loop(struct lib9p_srv *srv, lo_interface net_stre
  *
  * Errors that this function itself may send to clients:
  *
- * @errno L_EMSGSIZE   T-message has size[4] bigger than max_msg_size
- * @errno L_EDOM       Tversion specified an impossibly small max_msg_size
- * @errno L_EOPNOTSUPP T-message has an R-message type, or an unrecognized T-message type
- * @errno L_EBADMSG    T-message has wrong size[4] for its content, or has invalid UTF-8
+ * @errno E_POSIX_EMSGSIZE   T-message has size[4] bigger than max_msg_size
+ * @errno E_POSIX_EDOM       Tversion specified an impossibly small max_msg_size
+ * @errno E_POSIX_EOPNOTSUPP T-message has an R-message type, or an unrecognized T-message type
+ * @errno E_POSIX_EBADMSG    T-message has wrong size[4] for its content, or has invalid UTF-8
  */
 void lib9p_srv_read(struct lib9p_srv *srv, lo_interface net_stream_conn conn);
 
@@ -291,7 +304,7 @@ void lib9p_srv_worker_loop(struct lib9p_srv *srv);
  *
  * Errors that this function itself may send to clients:
  *
- * @errno L_ERANGE     R-message does not fit into max_msg_size
+ * @errno E_POSIX_ERANGE     R-message does not fit into max_msg_size
  */
 void lib9p_srv_worker(struct lib9p_srv_ctx *req);