[Libguestfs] [libnbd PATCH 2/4] states: Reject payload to NBD_REP_ACK
The protocol says NBD_REP_ACK should be sent without payload. Enforce
this.
---
generator/states-newstyle-opt-go.c | 5 +++++
generator/states-newstyle-opt-set-meta-context.c | 5 +++++
generator/states-newstyle-opt-structured-reply.c | 6 ++++++
3 files changed, 16 insertions(+)
diff --git a/generator/states-newstyle-opt-go.c b/generator/states-newstyle-opt-go.c
index 6a7b3af..200d16f 100644
--- a/generator/states-newstyle-opt-go.c
+++ b/generator/states-newstyle-opt-go.c
@@ -118,6 +118,11 @@
}
switch (reply) {
case NBD_REP_ACK:
+ if (len != 0) {
+ SET_NEXT_STATE (%.DEAD);
+ set_error (0, "handshake: invalid option reply length");
+ return -1;
+ }
SET_NEXT_STATE (%.READY);
return 0;
case NBD_REP_INFO:
diff --git a/generator/states-newstyle-opt-set-meta-context.c
b/generator/states-newstyle-opt-set-meta-context.c
index fdc0500..5a445b2 100644
--- a/generator/states-newstyle-opt-set-meta-context.c
+++ b/generator/states-newstyle-opt-set-meta-context.c
@@ -133,6 +133,11 @@ const char base_allocation[] = "base:allocation";
}
switch (reply) {
case NBD_REP_ACK: /* End of list of replies. */
+ if (len != 0) {
+ SET_NEXT_STATE (%.DEAD);
+ set_error (0, "handshake: invalid option reply length");
+ return -1;
+ }
SET_NEXT_STATE (%FINISH);
break;
case NBD_REP_META_CONTEXT: /* A context. */
diff --git a/generator/states-newstyle-opt-structured-reply.c
b/generator/states-newstyle-opt-structured-reply.c
index 56335fd..91acdcc 100644
--- a/generator/states-newstyle-opt-structured-reply.c
+++ b/generator/states-newstyle-opt-structured-reply.c
@@ -74,10 +74,16 @@
}
switch (reply) {
case NBD_REP_ACK:
+ if (conn->sbuf.or.option_reply.replylen != 0) {
+ SET_NEXT_STATE (%.DEAD);
+ set_error (0, "handshake: invalid option reply length");
+ return -1;
+ }
debug (conn->h, "negotiated structured replies on this connection");
conn->structured_replies = true;
break;
default:
+ /* XXX: capture instead of skip server's payload to NBD_REP_ERR*? */
debug (conn->h, "structured replies are not supported by this server");
conn->structured_replies = false;
break;
--
2.20.1