Commit 324a97ec authored by Diego Bes's avatar Diego Bes Committed by Daniel Stenberg
Browse files

http2: support "prior knowledge", no upgrade from HTTP/1.1 

Supports HTTP/2 over clear TCP

- Optimize switching to HTTP/2 by removing calls to init and setup
before switching. Switching will eventually call setup and setup calls
init.

- Supports new version to “force” the use of HTTP/2 over clean TCP

- Add common line parameter “--http2-prior-knowledge” to the Curl
  command line tool.
parent e6831829

docs/HTTP2.md

+3 −0
Original line number Diff line number Diff line
@@ -96,6 +96,9 @@ curl tool 


curl offers the `--http2` command line option to enable use of HTTP/2.



curl offers the `--http2-prior-knowledge` command line option to enable use of 

HTTP/2 without HTTP/1.1 Upgrade.



Since 7.47.0, the curl tool enables HTTP/2 by default for HTTPS connections.



HTTP Alternative Services

docs/curl.1

+5 −0
Original line number Diff line number Diff line
@@ -150,6 +150,11 @@ version. (Added in 7.33.0) 
.IP "--http2"

(HTTP) Tells curl to issue its requests using HTTP 2. This requires that the

underlying libcurl was built to support it. (Added in 7.33.0)

.IP "--http2-prior-knowledge"

(HTTP) Tells curl to issue its requests using HTTP 2 without HTTP/1.1 Upgrade. 

This requires prior knowledge that the server supports HTTP 2.

This requires that the underlying libcurl was built to support it. 

(Added in 7.49.0)

.IP "--no-npn"

Disable the NPN TLS extension. NPN is enabled by default if libcurl was built

with an SSL library that supports NPN. NPN is used by a libcurl that supports

docs/libcurl/symbols-in-versions

+1 −0
Original line number Diff line number Diff line
@@ -695,6 +695,7 @@ CURL_HTTP_VERSION_1_1 7.9.1 
CURL_HTTP_VERSION_2             7.43.0

CURL_HTTP_VERSION_2_0           7.33.0

CURL_HTTP_VERSION_2TLS          7.47.0

CURL_HTTP_VERSION_2_PRIOR_KNOWLEDGE 7.49.0

CURL_HTTP_VERSION_NONE          7.9.1

CURL_IPRESOLVE_V4               7.10.8

CURL_IPRESOLVE_V6               7.10.8

include/curl/curl.h

+2 −0
Original line number Diff line number Diff line
@@ -1727,6 +1727,8 @@ enum { 
  CURL_HTTP_VERSION_1_1,  /* please use HTTP 1.1 in the request */

  CURL_HTTP_VERSION_2_0,  /* please use HTTP 2 in the request */

  CURL_HTTP_VERSION_2TLS, /* use version 2 for HTTPS, version 1.1 for HTTP */

  CURL_HTTP_VERSION_2_PRIOR_KNOWLEDGE,  /* please use HTTP 2 without HTTP/1.1

                                           Upgrade */



  CURL_HTTP_VERSION_LAST /* *ILLEGAL* http version */

};

lib/http.c

+12 −8
Original line number Diff line number Diff line
@@ -1792,13 +1792,6 @@ CURLcode Curl_http(struct connectdata *conn, bool *done) 
    switch(conn->negnpn) {

    case CURL_HTTP_VERSION_2:

      conn->httpversion = 20; /* we know we're on HTTP/2 now */

      result = Curl_http2_init(conn);

      if(result)

        return result;



      result = Curl_http2_setup(conn);

      if(result)

        return result;



      result = Curl_http2_switched(conn, NULL, 0);

      if(result)
@@ -1808,7 +1801,18 @@ CURLcode Curl_http(struct connectdata *conn, bool *done) 
      /* continue with HTTP/1.1 when explicitly requested */

      break;

    default:

      /* and as fallback */

      /* Check if user wants to use HTTP/2 with clear TCP*/

#ifdef USE_NGHTTP2

      if(conn->data->set.httpversion ==

         CURL_HTTP_VERSION_2_PRIOR_KNOWLEDGE) {

        DEBUGF(infof(data, "HTTP/2 over clean TCP\n"));

        conn->httpversion = 20;



        result = Curl_http2_switched(conn, NULL, 0);

        if(result)

          return result;

      }

#endif

      break;

    }

  }