Remove some duplicate DTLS code.

In |dtls1_process_out_of_seq_message|, we know that
|frag_len| <= |msg_hdr->msg_len| so the later tests for |frag_len <
msg_hdr->msg_len| can be more clearly written as |frag_len !=
msg_hdr->msg_len|, since that's the only remaining case.

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Emilia Käsper <emilia@openssl.org>

Author: agl

ssl/d1_both.c

@@ -593,7 +593,7 @@ static unsigned long dtls1_max_handshake_message_len(const SSL *s)
 	}
 
 static int
-dtls1_reassemble_fragment(SSL *s, struct hm_header_st* msg_hdr, int *ok)
+dtls1_reassemble_fragment(SSL *s, const struct hm_header_st* msg_hdr, int *ok)
 	{
 	hm_fragment *frag = NULL;
 	pitem *item = NULL;
@@ -705,7 +705,7 @@ dtls1_reassemble_fragment(SSL *s, struct hm_header_st* msg_hdr, int *ok)
 
 
 static int
-dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok)
+dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st* msg_hdr, int *ok)
 {
 	int i=-1;
 	hm_fragment *frag = NULL;
@@ -725,7 +725,7 @@ dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok)
 	/* If we already have an entry and this one is a fragment,
 	 * don't discard it and rather try to reassemble it.
 	 */
-	if (item != NULL && frag_len < msg_hdr->msg_len)
+	if (item != NULL && frag_len != msg_hdr->msg_len)
 		item = NULL;
 
 	/* Discard the message if sequence number was already there, is
@@ -750,7 +750,7 @@ dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok)
 		}
 	else
 		{
-		if (frag_len < msg_hdr->msg_len)
+		if (frag_len != msg_hdr->msg_len)
 			return dtls1_reassemble_fragment(s, msg_hdr, ok);
 
 		if (frag_len > dtls1_max_handshake_message_len(s))