wip

4 files changed, 82 insertions, 82 deletions

diff --git a/lib9p/include/lib9p/9p.h b/lib9p/include/lib9p/9p.h
index 954498e..b33ae96 100644
--- a/lib9p/include/lib9p/9p.h
+++ b/lib9p/include/lib9p/9p.h
@@ -38,6 +38,9 @@ int lib9p_errorf(struct lib9p_ctx *ctx, uint32_t linux_errno, char const *fmt, .
  * @param net_bytes : the complete request, starting with the "size[4]"
  *
  * @return required size, or -1 on error
+ *
+ * @errno LINUX_EBADMSG: message is too short for content
+ * @errno LINUX_EBADMSG: message contains invalid UTF-8
  */
 ssize_t lib9p_unmarshal_size(struct lib9p_ctx *ctx, uint8_t *net_bytes);
 
@@ -67,6 +70,8 @@ void lib9p_unmarshal(struct lib9p_ctx *ctx, uint8_t *net_bytes,
  *
  * @return ret_bytes : the buffer to encode to, must be at be at least lib9p_ctx_max_msg_size(ctx) bytes
  * @return whether there was an error (false=success, true=error)
+ *
+ * @errno LINUX_ERANGE: reply does not fit in ctx->max_msg_size
  */
 bool lib9p_marshal(struct lib9p_ctx *ctx, enum lib9p_msg_type typ, uint16_t tag, void *body,
                    uint8_t *ret_bytes);
diff --git a/lib9p/srv.c b/lib9p/srv.c
index 9a68a2b..039b4c2 100644
--- a/lib9p/srv.c
+++ b/lib9p/srv.c
@@ -16,8 +16,7 @@ struct lib9p_srvconn {
 	cid_t                    reader;
 	int                      fd;
 	/* mutable */
-	uint32_t                 max_msg_size;
-	enum lib9p_version       version;
+	struct lib9p_ctx         ctx;
 	unsigned int             refcount;
 };
 
@@ -26,6 +25,19 @@ struct lib9p_srvreq {
 	uint8_t                 *msg;
 };
 
+static void marshal_error(struct lib9p_ctx *ctx, uint16_t tag, uint8_t *net) {
+	struct lib9p_msg_Rerror host = {
+		.ename = {
+			.len = strnlen(ctx->err_msg, CONFIG_9P_MAX_ERR_SIZE),
+			.utf8 = (uint8_t*)ctx->err_msg,
+		},
+		.errno = ctx->err_num,
+	};
+	lib9p_marshal(ctx, LIB9P_TYP_Rerror, tag, &host, net);
+}
+
+void handle_message(struct lib9p_srvconn *conn, uint8_t *net);
+
 COROUTINE lib9p_srv_read_cr(void *_srv) {
 	uint8_t buf[CONFIG_9P_MAX_MSG_SIZE];
 
@@ -37,9 +49,11 @@ COROUTINE lib9p_srv_read_cr(void *_srv) {
 		struct lib9p_srvconn conn = {
 			.srv          = srv,
 			.reader       = cr_getcid(),
-			
-			.max_msg_size = CONFIG_9P_MAX_MSG_SIZE,
-			.version      = LIB9P_VER_UNINITIALIZED,
+
+			.ctx          = {
+				.version      = LIB9P_VER_UNINITIALIZED,
+				.max_msg_size = CONFIG_9P_MAX_MSG_SIZE,
+			},
 			.refcount     = 1,
 		};
 		conn.fd = netio_accept(srv->sockfd);
@@ -54,7 +68,7 @@ COROUTINE lib9p_srv_read_cr(void *_srv) {
 			while (done < goal) {
 				ssize_t r = netio_read(conn.fd, &buf[done], sizeof(buf)-done);
 				if (r < 0) {
-					fprintf(stderr, "error: read: %m", -r);
+					fprintf(stderr, "error: read: %s", strerror(-r));
 					goto close;
 				} else if (r == 0) {
 					if (done != 0)
@@ -69,16 +83,11 @@ COROUTINE lib9p_srv_read_cr(void *_srv) {
 				fprintf(stderr, "error: T-message is impossibly small");
 				goto close;
 			}
-			if (goal > conn.max_msg_size) {
-				struct lib9p_ctx ctx = {
-					.version      = conn.version,
-					.max_msg_size = conn.max_msg_size,
-				};
-				if (initialized)
-					lib9p_errorf(&ctx, LINUX_EMSGSIZE, "T-message larger than negotiated limit (%zu > %zu)", goal, conn.max_msg_size);
-				else
-					lib9p_errorf(&ctx, LINUX_EMSGSIZE, "T-message larger than server limit (%zu > %zu)", goal, conn.max_msg_size);
-				marshal_error(&ctx, buf);
+			if (goal > conn.ctx.max_msg_size) {
+				lib9p_errorf(&conn.ctx, LINUX_EMSGSIZE, "T-message larger than %s limit (%zu > %zu)",
+				             conn.ctx.version ? "negotiated" : "server", goal, conn.ctx.max_msg_size);
+				uint16_t tag = decode_u16le(&buf[5]);
+				marshal_error(&conn.ctx, tag, buf);
 				netio_write(conn.fd, buf, decode_u32le(buf));
 				continue;
 			}
@@ -86,7 +95,7 @@ COROUTINE lib9p_srv_read_cr(void *_srv) {
 			while (done < goal) {
 				ssize_t r = netio_read(conn.fd, &buf[done], sizeof(buf)-done);
 				if (r < 0) {
-					fprintf(stderr, "error: read: %m", -r);
+					fprintf(stderr, "error: read: %s", strerror(-r));
 					goto close;
 				} else if (r == 0) {
 					fprintf(stderr, "error: read: unexpected EOF");
@@ -96,7 +105,7 @@ COROUTINE lib9p_srv_read_cr(void *_srv) {
 			}
 
 			/* Handle the message... */
-			if (conn.version == LIB9P_VER_UNINITIALIZED) {
+			if (conn.ctx.version == LIB9P_VER_UNINITIALIZED) {
 				/* ...synchronously if we haven't negotiated the protocol yet, ... */
 				handle_message(&conn, buf);
 			} else {
@@ -140,7 +149,7 @@ COROUTINE lib9p_srv_write_cr(void *_srv) {
 	cr_end();
 }
 
-void handle_message(lib9p_srvconn *conn, uint8_t *net) {
+void handle_message(struct lib9p_srvconn *conn, uint8_t *net) {
 	uint8_t host[CONFIG_9P_MAX_MSG_SIZE];
 
 	struct lib9p_ctx ctx = {
@@ -175,24 +184,5 @@ void handle_message(lib9p_srvconn *conn, uint8_t *net) {
 	netio_write(req.conn->fd, net, decode_u32le(net));
 }
 
-static inline uint16_t min_u16(uint16_t a, b) {
-	return (a < b) ? a : b;
-}
-
-/* We have special code for marshaling Rerror because we don't ever
- * want to produce an error because the err_msg is too long for the
- * `ctx->max_msg_size`!  */
-void marshal_error(struct lib9p_ctx *ctx, uint16_t tag, uint8_t *net) {
-	struct lib9p_msg_Rerror host = {
-		.ename = {
-			.len = strnlen(ctx->err_msg, CONFIG_9P_MAX_ERR_SIZE),
-			.utf8 = ctx->err_msg,
-		},
-	};
-	if (host.ename.len + ctx->Rerror_overhead > ctx->max_msg_size)
-		host.ename.len = ctx->max_msg_size - overhead;
-	lib9p_marshal(ctx, tag, host, net);
-}
-
-ERANGE for reply too large
-EPROTONOSUPPORT for version errors
+// EMSGSIZE for request too large
+// EPROTONOSUPPORT for version errors
diff --git a/lib9p/types.c b/lib9p/types.c
index 5b6d0a0..071e3c8 100644
--- a/lib9p/types.c
+++ b/lib9p/types.c
@@ -83,10 +83,10 @@ static inline bool checksize_stat(struct _checksize_ctx *ctx) {
 	    || checksize_s(ctx)
 	    || checksize_s(ctx)
 	    || checksize_s(ctx)
-	    || ( ( (ctx->ctx->version==LIB9P_VER_9P2000_u) ) && checksize_s(ctx) )
-	    || ( ( (ctx->ctx->version==LIB9P_VER_9P2000_u) ) && checksize_4(ctx) )
-	    || ( ( (ctx->ctx->version==LIB9P_VER_9P2000_u) ) && checksize_4(ctx) )
-	    || ( ( (ctx->ctx->version==LIB9P_VER_9P2000_u) ) && checksize_4(ctx) );
+	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && checksize_s(ctx) )
+	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && checksize_4(ctx) )
+	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && checksize_4(ctx) )
+	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && checksize_4(ctx) );
 }
 
 static bool checksize_Tversion(struct _checksize_ctx *ctx) {
@@ -103,7 +103,7 @@ static bool checksize_Tauth(struct _checksize_ctx *ctx) {
 	return checksize_4(ctx)
 	    || checksize_s(ctx)
 	    || checksize_s(ctx)
-	    || ( ( (ctx->ctx->version==LIB9P_VER_9P2000_u) ) && checksize_4(ctx) );
+	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && checksize_4(ctx) );
 }
 
 static bool checksize_Rauth(struct _checksize_ctx *ctx) {
@@ -123,7 +123,7 @@ static bool checksize_Rattach(struct _checksize_ctx *ctx) {
 
 static bool checksize_Rerror(struct _checksize_ctx *ctx) {
 	return checksize_s(ctx)
-	    || ( ( (ctx->ctx->version==LIB9P_VER_9P2000_u) ) && checksize_4(ctx) );
+	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && checksize_4(ctx) );
 }
 
 static bool checksize_Tflush(struct _checksize_ctx *ctx) {
@@ -521,7 +521,7 @@ static void unmarshal_Rswrite(struct _unmarshal_ctx *ctx, struct lib9p_msg_Rswri
 /* marshal_* ******************************************************************/
 
 static inline bool _marshal_too_large(struct _marshal_ctx *ctx) {
-	lib9p_errorf(ctx->ctx, LINUX_EMSGSIZE, "%s too large to marshal into %s limit (limit=%"PRIu32")",
+	lib9p_errorf(ctx->ctx, LINUX_ERANGE, "%s too large to marshal into %s limit (limit=%"PRIu32")",
 		(ctx->net_bytes[4] % 2 == 0) ? "T-message" : "R-message",
 		ctx->ctx->version ? "negotiated" : ((ctx->net_bytes[4] % 2 == 0) ? "client" : "server"),
 		ctx->ctx->max_msg_size);
@@ -599,10 +599,10 @@ static inline bool marshal_stat(struct _marshal_ctx *ctx, struct lib9p_stat *val
 	    || marshal_s(ctx, &val->file_owner_uid)
 	    || marshal_s(ctx, &val->file_owner_gid)
 	    || marshal_s(ctx, &val->file_last_modified_uid)
-	    || marshal_s(ctx, &val->file_extension)
-	    || marshal_4(ctx, &val->file_owner_n_uid)
-	    || marshal_4(ctx, &val->file_owner_n_gid)
-	    || marshal_4(ctx, &val->file_last_modified_n_uid);
+	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && marshal_s(ctx, &val->file_extension) )
+	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && marshal_4(ctx, &val->file_owner_n_uid) )
+	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && marshal_4(ctx, &val->file_owner_n_gid) )
+	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && marshal_4(ctx, &val->file_last_modified_n_uid) );
 }
 
 static bool marshal_Tversion(struct _marshal_ctx *ctx, struct lib9p_msg_Tversion *val) {
@@ -619,7 +619,7 @@ static bool marshal_Tauth(struct _marshal_ctx *ctx, struct lib9p_msg_Tauth *val)
 	return marshal_4(ctx, &val->afid)
 	    || marshal_s(ctx, &val->uname)
 	    || marshal_s(ctx, &val->aname)
-	    || marshal_4(ctx, &val->n_uname);
+	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && marshal_4(ctx, &val->n_uname) );
 }
 
 static bool marshal_Rauth(struct _marshal_ctx *ctx, struct lib9p_msg_Rauth *val) {
@@ -638,8 +638,11 @@ static bool marshal_Rattach(struct _marshal_ctx *ctx, struct lib9p_msg_Rattach *
 }
 
 static bool marshal_Rerror(struct _marshal_ctx *ctx, struct lib9p_msg_Rerror *val) {
+	/* Truncate the error-string if necessary to avoid returning ERANGE.  */
+	if (((uint32_t)val->ename.len) + ctx->ctx->Rerror_overhead > ctx->ctx->max_msg_size)
+		val->ename.len = ctx->ctx->max_msg_size - ctx->ctx->Rerror_overhead;
 	return marshal_s(ctx, &val->ename)
-	    || marshal_4(ctx, &val->errno);
+	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && marshal_4(ctx, &val->errno) );
 }
 
 static bool marshal_Tflush(struct _marshal_ctx *ctx, struct lib9p_msg_Tflush *val) {
diff --git a/lib9p/types.gen b/lib9p/types.gen
index 48f8107..44eebbe 100755
--- a/lib9p/types.gen
+++ b/lib9p/types.gen
@@ -205,14 +205,22 @@ def c_typename(idprefix: str, typ: Atom | Struct) -> str:
             raise ValueError(f"not a type: {typ.__class__.__name__}")
 
 
+def c_verenum(idprefix: str, ver: str) -> str:
+    return f"{idprefix.upper()}VER_{ver.replace('.', '_')}"
+
+
 def c_vercomment(versions: set[str]) -> str | None:
     if "9P2000" in versions:
         return None
     return "/* " + (", ".join(sorted(versions))) + " */"
 
 
-def c_ver(idprefix: str, ver: str) -> str:
-    return f"{idprefix.upper()}VER_{ver.replace('.', '_')}"
+def c_vercond(idprefix: str, versions: set[str]) -> str:
+    if len(versions) == 1:
+        return f"(ctx->ctx->version=={c_verenum(idprefix, next(v for v in versions))})"
+    return (
+        "( " + (" || ".join(c_vercond(idprefix, {v}) for v in sorted(versions))) + " )"
+    )
 
 
 def gen_h(idprefix: str, versions: set[str], structs: list[Struct]) -> str:
@@ -233,7 +241,7 @@ enum {idprefix}version {{
 """
     verwidth = max(len(v) for v in versions)
     for ver in sorted(versions):
-        ret += f"\t{c_ver(idprefix, ver)},"
+        ret += f"\t{c_verenum(idprefix, ver)},"
         ret += (" " * (verwidth - len(ver))) + ' /* "' + ver + '" */\n'
     ret += f"\t{idprefix.upper()}VER_NUM,\n"
     ret += "};\n"
@@ -396,7 +404,9 @@ static inline bool _checksize_list(struct _checksize_ctx *ctx,
                 ret += "\tif (checksize_4(ctx))\n"
                 ret += "\t\treturn true;\n"
                 ret += "\tuint32_t len = decode_u32le(&ctx->net_bytes[base_offset]);\n"
-                ret += "\treturn _checksize_net(ctx, len) || _checksize_host(ctx, len);\n"
+                ret += (
+                    "\treturn _checksize_net(ctx, len) || _checksize_host(ctx, len);\n"
+                )
                 ret += "}\n"
             case "s":
                 # Add an extra nul-byte on the host, and validate
@@ -414,22 +424,12 @@ static inline bool _checksize_list(struct _checksize_ctx *ctx,
                 ret += "}\n"
             case _:
                 struct_versions = struct.members[0].ver
-
                 prefix = prefix0
                 prev_size: int | None = None
                 for member in struct.members:
                     ret += f"\n{prefix}"
                     if member.ver != struct_versions:
-                        ret += (
-                            "( ( "
-                            + (
-                                " || ".join(
-                                    f"(ctx->ctx->version=={c_ver(idprefix, v)})"
-                                    for v in sorted(member.ver)
-                                )
-                            )
-                            + " ) && "
-                        )
+                        ret += "( " + c_vercond(idprefix, member.ver) + " && "
                     if member.cnt is not None:
                         assert prev_size
                         ret += f"_checksize_list(ctx, decode_u{prev_size*8}le(&ctx->net_bytes[ctx->net_offset-{prev_size}]), checksize_{member.typ.name}, sizeof({c_typename(idprefix, member.typ)}))"
@@ -478,16 +478,7 @@ static inline void unmarshal_8(struct _unmarshal_ctx *ctx, uint64_t *out) {
             ret += "\t"
             prefix = "\t"
             if member.ver != struct_versions:
-                ret += (
-                    "if ( "
-                    + (
-                        " || ".join(
-                            f"(ctx->ctx->version=={c_ver(idprefix, v)})"
-                            for v in sorted(member.ver)
-                        )
-                    )
-                    + " ) "
-                )
+                ret += "if ( " + c_vercond(idprefix, member.ver) + " ) "
                 prefix = "\t\t"
             if member.cnt:
                 if member.ver != struct_versions:
@@ -507,7 +498,7 @@ static inline void unmarshal_8(struct _unmarshal_ctx *ctx, uint64_t *out) {
 /* marshal_* ******************************************************************/
 
 static inline bool _marshal_too_large(struct _marshal_ctx *ctx) {
-	lib9p_errorf(ctx->ctx, LINUX_EMSGSIZE, "%s too large to marshal into %s limit (limit=%"PRIu32")",
+	lib9p_errorf(ctx->ctx, LINUX_ERANGE, "%s too large to marshal into %s limit (limit=%"PRIu32")",
 		(ctx->net_bytes[4] % 2 == 0) ? "T-message" : "R-message",
 		ctx->ctx->version ? "negotiated" : ((ctx->net_bytes[4] % 2 == 0) ? "client" : "server"),
 		ctx->ctx->max_msg_size);
@@ -556,21 +547,32 @@ static inline bool marshal_8(struct _marshal_ctx *ctx, uint64_t *val) {
             ret += "}\n"
             continue
 
+        if struct.name == "Rerror":
+            ret += "\n\t/* Truncate the error-string if necessary to avoid returning ERANGE.  */"
+            ret += "\n\tif (((uint32_t)val->ename.len) + ctx->ctx->Rerror_overhead > ctx->ctx->max_msg_size)"
+            ret += "\n\t\tval->ename.len = ctx->ctx->max_msg_size - ctx->ctx->Rerror_overhead;"
+
         prefix0 = "\treturn "
         prefix1 = "\t    || "
         prefix2 = "\t       "
 
+        struct_versions = struct.members[0].ver
         prefix = prefix0
         for member in struct.members:
+            ret += f"\n{prefix}"
+            if member.ver != struct_versions:
+                ret += "( " + c_vercond(idprefix, member.ver) + " && "
             if member.cnt:
-                ret += f"\n{prefix }({{"
+                ret += "({"
                 ret += f"\n{prefix2}\tbool err = false;"
                 ret += f"\n{prefix2}\tfor (typeof(val->{member.cnt}) i = 0; i < val->{member.cnt} && !err; i++)"
                 ret += f"\n{prefix2}\t\terr = marshal_{member.typ.name}(ctx, &val->{member.name}[i]);"
                 ret += f"\n{prefix2}\terr;"
                 ret += f"\n{prefix2}}})"
             else:
-                ret += f"\n{prefix}marshal_{member.typ.name}(ctx, &val->{member.name})"
+                ret += f"marshal_{member.typ.name}(ctx, &val->{member.name})"
+            if member.ver != struct_versions:
+                ret += " )"
             prefix = prefix1
         ret += ";\n}\n"
 
@@ -595,7 +597,7 @@ struct _vtable_version _{idprefix}vtables[LIB9P_VER_NUM] = {{
 	}}}},
 """
     for ver in sorted(versions):
-        ret += f"\t[{c_ver(idprefix, ver)}] = {{ .msgs = {{\n"
+        ret += f"\t[{c_verenum(idprefix, ver)}] = {{ .msgs = {{\n"
         for msg in structs:
             if ver not in msg.msgver:
                 continue