net: support ALPN.

net/third_party/nss/ssl/ssl.h

 /*
  * This file contains prototypes for the public SSL functions.
  *
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 /* $Id$ */
 
 #ifndef __ssl_h_
 #define __ssl_h_
@@ skipping 186 matching lines @@
 SSL_IMPORT SECStatus SSL_SetNextProtoCallback(PRFileDesc *fd,
                                               SSLNextProtoCallback callback,
                                               void *arg);
 
 /* SSL_SetNextProtoNego can be used as an alternative to
  * SSL_SetNextProtoCallback. It also causes a client to advertise NPN and
  * installs a default callback function which selects the first supported
  * protocol in server-preference order. If no matching protocol is found it
  * selects the first supported protocol.
  *
+ * In addition to SSL_SetNextProtoCallback, this allows the client to also
+ * support ALPN.

[Ryan Sleevi, 2013/07/02 00:41:43]

nit: I'm not sure I fully parse this comment. Does this mean
SSL_SetNextProtoCallback *also* supports ALPN? This function is documented as
being an *alternative* to SSL_SetNextProtoCallbac, so the "in addition" is
confusing.

[agl, 2013/07/02 17:43:01]

You're right, that was nonsense.

" * Using this function also allows the client to transparently support ALPN.
 * The same set of protocols will be advertised via ALPN and, if the server
 * uses ALPN to select a protocol, SSL_GetNextProto will return
 * SSL_NEXT_PROTO_SELECTED as the state.
"

+ *
  * The supported protocols are specified in |data| in wire-format (8-bit
  * length-prefixed). For example: "\010http/1.1\006spdy/2". */
 SSL_IMPORT SECStatus SSL_SetNextProtoNego(PRFileDesc *fd,
                                           const unsigned char *data,
                                           unsigned int length);
 
 typedef enum SSLNextProtoState { 
   SSL_NEXT_PROTO_NO_SUPPORT = 0, /* No peer support                */
   SSL_NEXT_PROTO_NEGOTIATED = 1, /* Mutual agreement               */
-  SSL_NEXT_PROTO_NO_OVERLAP = 2  /* No protocol overlap found      */
+  SSL_NEXT_PROTO_NO_OVERLAP = 2, /* No protocol overlap found      */
+  SSL_NEXT_PROTO_SELECTED   = 3, /* Server selected proto (ALPN)   */
 } SSLNextProtoState;
 
 /* SSL_GetNextProto can be used in the HandshakeCallback or any time after
  * a handshake to retrieve the result of the Next Protocol negotiation.
  *
  * The length of the negotiated protocol, if any, is written into *bufLen.
  * If the negotiated protocol is longer than bufLenMax, then SECFailure is
  * returned. Otherwise, the negotiated protocol, if any, is written into buf,
  * and SECSuccess is returned. */
 SSL_IMPORT SECStatus SSL_GetNextProto(PRFileDesc *fd,
@@ skipping 865 matching lines @@
  * should continue using the connection. If the application passes a non-zero
  * value for second argument (error), or if SSL_AuthCertificateComplete returns
  * anything other than SECSuccess, then the application should close the
  * connection.
  */
 SSL_IMPORT SECStatus SSL_AuthCertificateComplete(PRFileDesc *fd,
                                                  PRErrorCode error);
 SEC_END_PROTOS
 
 #endif /* __ssl_h_ */