diff --git a/lib/libwebsockets.c b/lib/libwebsockets.c index ba596bf7..96d39343 100644 --- a/lib/libwebsockets.c +++ b/lib/libwebsockets.c @@ -900,6 +900,12 @@ libwebsocket_service_fd(struct libwebsocket_context *this, p += sprintf(p, "Sec-WebSocket-Key2: %s\x0d\x0a", key_2); + /* give userland a chance to append, eg, cookies */ + + this->protocols[0].callback(this, wsi, + LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER, + NULL, &p, (pkt + sizeof(pkt)) - p - 12); + p += sprintf(p, "\x0d\x0a"); read(this->fd_random, p, 8); @@ -927,9 +933,17 @@ libwebsocket_service_fd(struct libwebsocket_context *this, if (wsi->c_protocol) p += sprintf(p, "Sec-WebSocket-Protocol: %s\x0d\x0a", wsi->c_protocol); - p += sprintf(p, "Sec-WebSocket-Version: %d\x0d\x0a\x0d\x0a", + p += sprintf(p, "Sec-WebSocket-Version: %d\x0d\x0a", wsi->ietf_spec_revision); + /* give userland a chance to append, eg, cookies */ + + this->protocols[0].callback(this, wsi, + LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER, + NULL, &p, (pkt + sizeof(pkt)) - p - 12); + + p += sprintf(p, "\x0d\x0a"); + /* prepare the expected server accept response */ strcpy((char *)buf, wsi->key_b64); diff --git a/lib/libwebsockets.h b/lib/libwebsockets.h index a97de07c..5d0f0473 100644 --- a/lib/libwebsockets.h +++ b/lib/libwebsockets.h @@ -47,6 +47,7 @@ enum libwebsocket_callback_reasons { LWS_CALLBACK_OPENSSL_LOAD_EXTRA_CLIENT_VERIFY_CERTS, LWS_CALLBACK_OPENSSL_LOAD_EXTRA_SERVER_VERIFY_CERTS, LWS_CALLBACK_OPENSSL_PERFORM_CLIENT_CERT_VERIFICATION, + LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER, /* external poll() management support */ LWS_CALLBACK_ADD_POLL_FD, @@ -276,6 +277,30 @@ struct libwebsocket_context; * the default callback action of returning 0 allows the client * certificates. * + * LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER: this callback happens + * when a client handshake is being compiled. @user is NULL, + * @in is a char **, it's pointing to a char * which holds the + * next location in the header buffer where you can add + * headers, and @len is the remaining space in the header buffer, + * which is typically some hundreds of bytes. So, to add a canned + * cookie, your handler code might look similar to: + * + * char **p = (char **)in; + * + * if (len < 100) + * return 1; + * + * *p += sprintf(*p, "Cookie: a=b\x0d\x0a"); + * + * return 0; + * + * Notice if you add anything, you just have to take care about + * the CRLF on the line you added. Obviously this callback is + * optional, if you don't handle it everything is fine. + * + * Notice the callback is coming to protocols[0] all the time, + * because there is no specific protocol handshook yet. + * * The next four reasons are optional and only need taking care of if you * will be integrating libwebsockets sockets into an external polling * array. diff --git a/libwebsockets-api-doc.html b/libwebsockets-api-doc.html index 966df7d0..8cc72c48 100644 --- a/libwebsockets-api-doc.html +++ b/libwebsockets-api-doc.html @@ -621,6 +621,32 @@ conventions, return 0 to mean the cert is OK or 1 to fail it. This also means that if you don't handle this callback then the default callback action of returning 0 allows the client certificates. + +

LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER

+
+this callback happens +when a client handshake is being compiled. user is NULL, +in is a char **, it's pointing to a char * which holds the +next location in the header buffer where you can add +headers, and len is the remaining space in the header buffer, +which is typically some hundreds of bytes. So, to add a canned +cookie, your handler code might look similar to: +

+char **p = (char **)in; +

+if (len < 100) +return 1; +

+*p += sprintf(*p, "Cookie: a=b\x0d\x0a"); +

+return 0; +

+Notice if you add anything, you just have to take care about +the CRLF on the line you added. Obviously this callback is +optional, if you don't handle it everything is fine. +

+Notice the callback is coming to protocols[0] all the time, +because there is no specific protocol handshook yet.

The next four reasons are optional and only need taking care of if you will be integrating libwebsockets sockets into an external polling