diff options
| -rw-r--r-- | lib9p/protogen/c.py | 5 | ||||
| -rw-r--r-- | lib9p/srv.c | 12 |
2 files changed, 12 insertions, 5 deletions
diff --git a/lib9p/protogen/c.py b/lib9p/protogen/c.py index a6824ce..363f0df 100644 --- a/lib9p/protogen/c.py +++ b/lib9p/protogen/c.py @@ -122,6 +122,11 @@ def gen_c(versions: set[str], typs: list[idl.UserType]) -> str: ret += f"const struct {c9util.ident('_ver_tentry')} {c9util.ident('_table_ver')}[{c9util.ver_enum('NUM')}] = {{\n" rerror = next(typ for typ in typs if typ.typname == "Rerror") for ver in ["unknown", *sorted(versions)]: + # XXX: There are good arguments that min_msg_size should be + # something larger than rerror.min_size(). + # srv.c:respond_error() assumes that min_msg_size is + # rerror.min_size(); if you do change min_msg_size to + # something larger, then be sure to update respond_error(). if ver == "unknown": min_msg_size = rerror.min_size("9P2000") # SPECIAL (initialization) else: diff --git a/lib9p/srv.c b/lib9p/srv.c index 5ff083f..836890c 100644 --- a/lib9p/srv.c +++ b/lib9p/srv.c @@ -127,7 +127,6 @@ struct _srv_sess { struct _srv_conn *parent_conn; enum lib9p_version version; uint32_t max_msg_size; - uint32_t rerror_overhead; /* mutable */ bool initialized; bool closing; @@ -190,10 +189,15 @@ static void respond_error(struct _lib9p_srv_req *req) { struct _srv_sess *sess = req->parent_sess; + /* XXX: This assumes that a version's min_msg_size is the + * Rerror overhead. That's true for the current + * implementation of protogen, but is a sneaky assumption. */ + uint32_t overhead = lib9p_version_min_msg_size(sess->version); + /* Truncate the error-string if necessary to avoid needing to * return LINUX_ERANGE. */ - if (((uint32_t)host.errstr.len) + sess->rerror_overhead > sess->max_msg_size) - host.errstr.len = sess->max_msg_size - sess->rerror_overhead; + if (((uint32_t)host.errstr.len) + overhead > sess->max_msg_size) + host.errstr.len = sess->max_msg_size - overhead; struct lib9p_Rmsg_send_buf net; @@ -267,7 +271,6 @@ void lib9p_srv_read(struct lib9p_srv *srv, lo_interface net_stream_conn _conn) { .parent_conn = &conn, .version = LIB9P_VER_unknown, .max_msg_size = CONFIG_9P_SRV_MAX_MSG_SIZE, - .rerror_overhead = lib9p_version_min_msg_size(LIB9P_VER_unknown), .initialized = false, }; for (;;) { @@ -659,7 +662,6 @@ static void handle_Tversion(struct _lib9p_srv_req *ctx, /* Replace the old session with the new session. */ ctx->parent_sess->version = version; ctx->parent_sess->max_msg_size = resp->max_msg_size; - ctx->parent_sess->rerror_overhead = min_msg_size; } static void handle_Tauth(struct _lib9p_srv_req *ctx, |