DTLS Multicast

Added an API so a session may be queried to see if it has seen any messages
from a specified peerId.

src/ssl.c

@@ -1024,6 +1024,35 @@ int wolfSSL_mcast_peer_add(WOLFSSL* ssl, word16 peerId, int remove)
 }
 
 
+/* If peerId is in the list of peers and its last sequence number is non-zero,
+ * return 1, otherwise return 0. */
+int wolfSSL_mcast_peer_known(WOLFSSL* ssl, unsigned short peerId)
+{
+    int known = 0;
+    int i;
+
+    WOLFSSL_ENTER("wolfSSL_mcast_peer_known()");
+
+    if (ssl == NULL || peerId > 255) {
+        return BAD_FUNC_ARG;
+    }
+
+    for (i = 0; i < WOLFSSL_DTLS_PEERSEQ_SZ; i++) {
+        if (ssl->keys.peerSeq[i].peerId == peerId) {
+            if (ssl->keys.peerSeq[i].nextSeq_hi ||
+                ssl->keys.peerSeq[i].nextSeq_lo) {
+
+                known = 1;
+            }
+            break;
+        }
+    }
+
+    WOLFSSL_LEAVE("wolfSSL_mcast_peer_known()", known);
+    return known;
+}
+
+
 int wolfSSL_CTX_mcast_set_highwater_cb(WOLFSSL_CTX* ctx, word32 maxSeq,
                                        word32 first, word32 second,
                                        CallbackMcastHighwater cb)

wolfssl/ssl.h

@@ -516,6 +516,7 @@ WOLFSSL_API int  wolfSSL_set_secret(WOLFSSL*, unsigned short,
                      const unsigned char*);
 WOLFSSL_API int  wolfSSL_mcast_read(WOLFSSL*, unsigned short*, void*, int);
 WOLFSSL_API int  wolfSSL_mcast_peer_add(WOLFSSL*, unsigned short, int);
+WOLFSSL_API int  wolfSSL_mcast_peer_known(WOLFSSL*, unsigned short);
 WOLFSSL_API int  wolfSSL_mcast_get_max_peers(void);
 typedef int (*CallbackMcastHighwater)(unsigned short peerId,
                                       unsigned int maxSeq,