curl 7.38.0 (reduced)

Extract upstream curl using the following shell code.

url=git://github.com/bagder/curl.git &&
v=7.38.0 &&
r=202aa9f7 &&
paths="
  CMake/*
  CMakeLists.txt
  COPYING
  include/curl/*.h
  include/curl/curlbuild.h.cmake
  lib/*.c
  lib/*.h
  lib/CMakeLists.txt
  lib/Makefile.inc
  lib/curl_config.h.cmake
  lib/libcurl.rc
  lib/vtls/*.c
  lib/vtls/*.h
" &&
mkdir curl-$v-g$r-reduced &&
git clone $url curl-git &&
date=$(cd curl-git && git log -n 1 --format='%cd' $r) &&
(cd curl-git && git checkout $r &&
 git archive --format=tar $r -- $paths) |
(cd curl-$v-g$r-reduced && tar xv &&
 rm lib/config-*.h) &&
echo "g$r date: $date"

1 files changed, 1036 insertions, 0 deletions

diff --git a/lib/http2.c b/lib/http2.c
new file mode 100644
index 0000000..604514d
--- /dev/null
+++ b/lib/http2.c
@@ -0,0 +1,1036 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2014, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at http://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+#include "curl_setup.h"
+
+#ifdef USE_NGHTTP2
+#define _MPRINTF_REPLACE
+#include <curl/mprintf.h>
+
+#include <nghttp2/nghttp2.h>
+#include "urldata.h"
+#include "http2.h"
+#include "http.h"
+#include "sendf.h"
+#include "curl_base64.h"
+#include "curl_memory.h"
+#include "rawstr.h"
+#include "multiif.h"
+
+/* include memdebug.h last */
+#include "memdebug.h"
+
+#if (NGHTTP2_VERSION_NUM < 0x000600)
+#error too old nghttp2 version, upgrade!
+#endif
+
+static int http2_perform_getsock(const struct connectdata *conn,
+                                 curl_socket_t *sock, /* points to
+                                                         numsocks
+                                                         number of
+                                                         sockets */
+                                 int numsocks)
+{
+  const struct http_conn *httpc = &conn->proto.httpc;
+  int bitmap = GETSOCK_BLANK;
+  (void)numsocks;
+
+  /* TODO We should check underlying socket state if it is SSL socket
+     because of renegotiation. */
+  sock[0] = conn->sock[FIRSTSOCKET];
+
+  if(nghttp2_session_want_read(httpc->h2))
+    bitmap |= GETSOCK_READSOCK(FIRSTSOCKET);
+
+  if(nghttp2_session_want_write(httpc->h2))
+    bitmap |= GETSOCK_WRITESOCK(FIRSTSOCKET);
+
+  return bitmap;
+}
+
+static int http2_getsock(struct connectdata *conn,
+                         curl_socket_t *sock, /* points to numsocks
+                                                 number of sockets */
+                         int numsocks)
+{
+  return http2_perform_getsock(conn, sock, numsocks);
+}
+
+static CURLcode http2_disconnect(struct connectdata *conn,
+                                 bool dead_connection)
+{
+  struct http_conn *httpc = &conn->proto.httpc;
+  (void)dead_connection;
+
+  infof(conn->data, "HTTP/2 DISCONNECT starts now\n");
+
+  nghttp2_session_del(httpc->h2);
+
+  Curl_safefree(httpc->header_recvbuf->buffer);
+  Curl_safefree(httpc->header_recvbuf);
+
+  Curl_safefree(httpc->inbuf);
+
+  infof(conn->data, "HTTP/2 DISCONNECT done\n");
+
+  return CURLE_OK;
+}
+
+/*
+ * HTTP2 handler interface. This isn't added to the general list of protocols
+ * but will be used at run-time when the protocol is dynamically switched from
+ * HTTP to HTTP2.
+ */
+const struct Curl_handler Curl_handler_http2 = {
+  "HTTP2",                              /* scheme */
+  ZERO_NULL,                            /* setup_connection */
+  Curl_http,                            /* do_it */
+  ZERO_NULL,                            /* done */
+  ZERO_NULL,                            /* do_more */
+  ZERO_NULL,                            /* connect_it */
+  ZERO_NULL,                            /* connecting */
+  ZERO_NULL,                            /* doing */
+  http2_getsock,                        /* proto_getsock */
+  http2_getsock,                        /* doing_getsock */
+  ZERO_NULL,                            /* domore_getsock */
+  http2_perform_getsock,                /* perform_getsock */
+  http2_disconnect,                     /* disconnect */
+  ZERO_NULL,                            /* readwrite */
+  PORT_HTTP,                            /* defport */
+  CURLPROTO_HTTP,                       /* protocol */
+  PROTOPT_NONE                          /* flags */
+};
+
+const struct Curl_handler Curl_handler_http2_ssl = {
+  "HTTP2",                              /* scheme */
+  ZERO_NULL,                            /* setup_connection */
+  Curl_http,                            /* do_it */
+  ZERO_NULL,                            /* done */
+  ZERO_NULL,                            /* do_more */
+  ZERO_NULL,                            /* connect_it */
+  ZERO_NULL,                            /* connecting */
+  ZERO_NULL,                            /* doing */
+  http2_getsock,                        /* proto_getsock */
+  http2_getsock,                        /* doing_getsock */
+  ZERO_NULL,                            /* domore_getsock */
+  http2_perform_getsock,                /* perform_getsock */
+  http2_disconnect,                     /* disconnect */
+  ZERO_NULL,                            /* readwrite */
+  PORT_HTTP,                            /* defport */
+  CURLPROTO_HTTPS,                      /* protocol */
+  PROTOPT_SSL                           /* flags */
+};
+
+/*
+ * Store nghttp2 version info in this buffer, Prefix with a space.  Return
+ * total length written.
+ */
+int Curl_http2_ver(char *p, size_t len)
+{
+  nghttp2_info *h2 = nghttp2_version(0);
+  return snprintf(p, len, " nghttp2/%s", h2->version_str);
+}
+
+/*
+ * The implementation of nghttp2_send_callback type. Here we write |data| with
+ * size |length| to the network and return the number of bytes actually
+ * written. See the documentation of nghttp2_send_callback for the details.
+ */
+static ssize_t send_callback(nghttp2_session *h2,
+                             const uint8_t *data, size_t length, int flags,
+                             void *userp)
+{
+  struct connectdata *conn = (struct connectdata *)userp;
+  struct http_conn *httpc = &conn->proto.httpc;
+  ssize_t written;
+  CURLcode rc;
+  (void)h2;
+  (void)flags;
+
+  rc = 0;
+  written = ((Curl_send*)httpc->send_underlying)(conn, FIRSTSOCKET,
+                                                 data, length, &rc);
+
+  if(rc == CURLE_AGAIN) {
+    return NGHTTP2_ERR_WOULDBLOCK;
+  }
+
+  if(written == -1) {
+    failf(conn->data, "Failed sending HTTP2 data");
+    return NGHTTP2_ERR_CALLBACK_FAILURE;
+  }
+
+  if(!written)
+    return NGHTTP2_ERR_WOULDBLOCK;
+
+  return written;
+}
+
+static int on_frame_recv(nghttp2_session *session, const nghttp2_frame *frame,
+                         void *userp)
+{
+  struct connectdata *conn = (struct connectdata *)userp;
+  struct http_conn *c = &conn->proto.httpc;
+  int rv;
+  size_t left, ncopy;
+
+  (void)session;
+  (void)frame;
+  infof(conn->data, "on_frame_recv() was called with header %x\n",
+        frame->hd.type);
+  switch(frame->hd.type) {
+  case NGHTTP2_DATA:
+    /* If body started, then receiving DATA is illegal. */
+    if(!c->bodystarted) {
+      rv = nghttp2_submit_rst_stream(session, NGHTTP2_FLAG_NONE,
+                                     frame->hd.stream_id,
+                                     NGHTTP2_PROTOCOL_ERROR);
+
+      if(nghttp2_is_fatal(rv)) {
+        return NGHTTP2_ERR_CALLBACK_FAILURE;
+      }
+    }
+    break;
+  case NGHTTP2_HEADERS:
+    if(frame->headers.cat == NGHTTP2_HCAT_REQUEST)
+      break;
+
+    if(c->bodystarted) {
+      /* Only valid HEADERS after body started is trailer header,
+         which is not fully supported in this code.  If HEADERS is not
+         trailer, then it is a PROTOCOL_ERROR. */
+      if((frame->hd.flags & NGHTTP2_FLAG_END_STREAM) == 0) {
+        rv = nghttp2_submit_rst_stream(session, NGHTTP2_FLAG_NONE,
+                                       frame->hd.stream_id,
+                                       NGHTTP2_PROTOCOL_ERROR);
+
+        if(nghttp2_is_fatal(rv)) {
+          return NGHTTP2_ERR_CALLBACK_FAILURE;
+        }
+      }
+      break;
+    }
+
+    if(c->status_code == -1) {
+      /* No :status header field means PROTOCOL_ERROR. */
+      rv = nghttp2_submit_rst_stream(session, NGHTTP2_FLAG_NONE,
+                                     frame->hd.stream_id,
+                                     NGHTTP2_PROTOCOL_ERROR);
+
+      if(nghttp2_is_fatal(rv)) {
+        return NGHTTP2_ERR_CALLBACK_FAILURE;
+      }
+
+      break;
+    }
+
+    /* Only final status code signals the end of header */
+    if(c->status_code / 100 != 1) {
+      c->bodystarted = TRUE;
+    }
+
+    c->status_code = -1;
+
+    Curl_add_buffer(c->header_recvbuf, "\r\n", 2);
+
+    left = c->header_recvbuf->size_used - c->nread_header_recvbuf;
+    ncopy = c->len < left ? c->len : left;
+
+    memcpy(c->mem, c->header_recvbuf->buffer + c->nread_header_recvbuf, ncopy);
+    c->nread_header_recvbuf += ncopy;
+
+    c->mem += ncopy;
+    c->len -= ncopy;
+    break;
+  case NGHTTP2_PUSH_PROMISE:
+    rv = nghttp2_submit_rst_stream(session, NGHTTP2_FLAG_NONE,
+                                   frame->push_promise.promised_stream_id,
+                                   NGHTTP2_CANCEL);
+    if(nghttp2_is_fatal(rv)) {
+      return rv;
+    }
+    break;
+  }
+  return 0;
+}
+
+static int on_invalid_frame_recv(nghttp2_session *session,
+                                 const nghttp2_frame *frame,
+                                 uint32_t error_code, void *userp)
+{
+  struct connectdata *conn = (struct connectdata *)userp;
+  (void)session;
+  (void)frame;
+  infof(conn->data, "on_invalid_frame_recv() was called, error_code = %d\n",
+        error_code);
+  return 0;
+}
+
+static int on_data_chunk_recv(nghttp2_session *session, uint8_t flags,
+                              int32_t stream_id,
+                              const uint8_t *data, size_t len, void *userp)
+{
+  struct connectdata *conn = (struct connectdata *)userp;
+  struct http_conn *c = &conn->proto.httpc;
+  size_t nread;
+  (void)session;
+  (void)flags;
+  (void)data;
+  infof(conn->data, "on_data_chunk_recv() "
+        "len = %u, stream = %x\n", len, stream_id);
+
+  if(stream_id != c->stream_id) {
+    return 0;
+  }
+
+  nread = c->len < len ? c->len : len;
+  memcpy(c->mem, data, nread);
+
+  c->mem += nread;
+  c->len -= nread;
+
+  infof(conn->data, "%zu data written\n", nread);
+
+  if(nread < len) {
+    c->data = data + nread;
+    c->datalen = len - nread;
+    return NGHTTP2_ERR_PAUSE;
+  }
+  return 0;
+}
+
+static int before_frame_send(nghttp2_session *session,
+                             const nghttp2_frame *frame,
+                             void *userp)
+{
+  struct connectdata *conn = (struct connectdata *)userp;
+  (void)session;
+  (void)frame;
+  infof(conn->data, "before_frame_send() was called\n");
+  return 0;
+}
+static int on_frame_send(nghttp2_session *session,
+                         const nghttp2_frame *frame,
+                         void *userp)
+{
+  struct connectdata *conn = (struct connectdata *)userp;
+  (void)session;
+  (void)frame;
+  infof(conn->data, "on_frame_send() was called\n");
+  return 0;
+}
+static int on_frame_not_send(nghttp2_session *session,
+                             const nghttp2_frame *frame,
+                             int lib_error_code, void *userp)
+{
+  struct connectdata *conn = (struct connectdata *)userp;
+  (void)session;
+  (void)frame;
+  infof(conn->data, "on_frame_not_send() was called, lib_error_code = %d\n",
+        lib_error_code);
+  return 0;
+}
+static int on_stream_close(nghttp2_session *session, int32_t stream_id,
+                           uint32_t error_code, void *userp)
+{
+  struct connectdata *conn = (struct connectdata *)userp;
+  struct http_conn *c = &conn->proto.httpc;
+  (void)session;
+  (void)stream_id;
+  infof(conn->data, "on_stream_close() was called, error_code = %d\n",
+        error_code);
+
+  if(stream_id != c->stream_id) {
+    return 0;
+  }
+
+  c->closed = TRUE;
+
+  return 0;
+}
+
+static int on_begin_headers(nghttp2_session *session,
+                            const nghttp2_frame *frame, void *userp)
+{
+  struct connectdata *conn = (struct connectdata *)userp;
+  (void)session;
+  (void)frame;
+  infof(conn->data, "on_begin_headers() was called\n");
+  return 0;
+}
+
+/* Decode HTTP status code.  Returns -1 if no valid status code was
+   decoded. */
+static int decode_status_code(const uint8_t *value, size_t len)
+{
+  int i;
+  int res;
+
+  if(len != 3) {
+    return -1;
+  }
+
+  res = 0;
+
+  for(i = 0; i < 3; ++i) {
+    char c = value[i];
+
+    if(c < '0' || c > '9') {
+      return -1;
+    }
+
+    res *= 10;
+    res += c - '0';
+  }
+
+  return res;
+}
+
+static const char STATUS[] = ":status";
+
+/* frame->hd.type is either NGHTTP2_HEADERS or NGHTTP2_PUSH_PROMISE */
+static int on_header(nghttp2_session *session, const nghttp2_frame *frame,
+                     const uint8_t *name, size_t namelen,
+                     const uint8_t *value, size_t valuelen,
+                     uint8_t flags,
+                     void *userp)
+{
+  struct connectdata *conn = (struct connectdata *)userp;
+  struct http_conn *c = &conn->proto.httpc;
+  int rv;
+  int goodname;
+  int goodheader;
+
+  (void)session;
+  (void)frame;
+  (void)flags;
+
+  if(frame->hd.stream_id != c->stream_id) {
+    return 0;
+  }
+
+  if(c->bodystarted) {
+    /* Ignore trailer or HEADERS not mapped to HTTP semantics.  The
+       consequence is handled in on_frame_recv(). */
+    return 0;
+  }
+
+  goodname = nghttp2_check_header_name(name, namelen);
+  goodheader = nghttp2_check_header_value(value, valuelen);
+
+  if(!goodname || !goodheader) {
+
+    infof(conn->data, "Detected bad incoming header %s%s, reset stream!\n",
+          goodname?"":"name",
+          goodheader?"":"value");
+
+    rv = nghttp2_submit_rst_stream(session, NGHTTP2_FLAG_NONE,
+                                   frame->hd.stream_id,
+                                   NGHTTP2_PROTOCOL_ERROR);
+
+    if(nghttp2_is_fatal(rv)) {
+      return NGHTTP2_ERR_CALLBACK_FAILURE;
+    }
+
+    return NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE;
+  }
+
+  if(namelen == sizeof(":status") - 1 &&
+     memcmp(STATUS, name, namelen) == 0) {
+
+    /* :status must appear exactly once. */
+    if(c->status_code != -1 ||
+       (c->status_code = decode_status_code(value, valuelen)) == -1) {
+
+      rv = nghttp2_submit_rst_stream(session, NGHTTP2_FLAG_NONE,
+                                     frame->hd.stream_id,
+                                     NGHTTP2_PROTOCOL_ERROR);
+      if(nghttp2_is_fatal(rv)) {
+        return NGHTTP2_ERR_CALLBACK_FAILURE;
+      }
+
+      return NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE;
+    }
+
+    Curl_add_buffer(c->header_recvbuf, "HTTP/2.0 ", 9);
+    Curl_add_buffer(c->header_recvbuf, value, valuelen);
+    Curl_add_buffer(c->header_recvbuf, "\r\n", 2);
+
+    return 0;
+  }
+  else {
+    /* Here we are sure that namelen > 0 because of
+       nghttp2_check_header_name().  Pseudo header other than :status
+       is illegal. */
+    if(c->status_code == -1 || name[0] == ':') {
+      rv = nghttp2_submit_rst_stream(session, NGHTTP2_FLAG_NONE,
+                                     frame->hd.stream_id,
+                                     NGHTTP2_PROTOCOL_ERROR);
+      if(nghttp2_is_fatal(rv)) {
+        return NGHTTP2_ERR_CALLBACK_FAILURE;
+      }
+
+      return NGHTTP2_ERR_TEMPORAL_CALLBACK_FAILURE;
+    }
+
+    /* convert to a HTTP1-style header */
+    Curl_add_buffer(c->header_recvbuf, name, namelen);
+    Curl_add_buffer(c->header_recvbuf, ":", 1);
+    Curl_add_buffer(c->header_recvbuf, value, valuelen);
+    Curl_add_buffer(c->header_recvbuf, "\r\n", 2);
+
+    infof(conn->data, "got http2 header: %.*s: %.*s\n",
+          namelen, name, valuelen, value);
+  }
+
+  return 0; /* 0 is successful */
+}
+
+static ssize_t data_source_read_callback(nghttp2_session *session,
+                                         int32_t stream_id,
+                                         uint8_t *buf, size_t length,
+                                         uint32_t *data_flags,
+                                         nghttp2_data_source *source,
+                                         void *userp)
+{
+  struct connectdata *conn = (struct connectdata *)userp;
+  struct http_conn *c = &conn->proto.httpc;
+  size_t nread;
+  (void)session;
+  (void)stream_id;
+  (void)source;
+
+  nread = c->upload_len < length ? c->upload_len : length;
+  if(nread > 0) {
+    memcpy(buf, c->upload_mem, nread);
+    c->upload_mem += nread;
+    c->upload_len -= nread;
+    c->upload_left -= nread;
+  }
+
+  if(c->upload_left == 0)
+    *data_flags = 1;
+  else if(nread == 0)
+    return NGHTTP2_ERR_DEFERRED;
+
+  return nread;
+}
+
+/*
+ * The HTTP2 settings we send in the Upgrade request
+ */
+static nghttp2_settings_entry settings[] = {
+  { NGHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS, 100 },
+  { NGHTTP2_SETTINGS_INITIAL_WINDOW_SIZE, NGHTTP2_INITIAL_WINDOW_SIZE },
+};
+
+#define H2_BUFSIZE 4096
+
+/*
+ * Initialize nghttp2 for a Curl connection
+ */
+CURLcode Curl_http2_init(struct connectdata *conn)
+{
+  if(!conn->proto.httpc.h2) {
+    int rc;
+    nghttp2_session_callbacks *callbacks;
+
+    conn->proto.httpc.inbuf = malloc(H2_BUFSIZE);
+    if(conn->proto.httpc.inbuf == NULL)
+      return CURLE_OUT_OF_MEMORY;
+
+    rc = nghttp2_session_callbacks_new(&callbacks);
+
+    if(rc) {
+      failf(conn->data, "Couldn't initialize nghttp2 callbacks!");
+      return CURLE_OUT_OF_MEMORY; /* most likely at least */
+    }
+
+    /* nghttp2_send_callback */
+    nghttp2_session_callbacks_set_send_callback(callbacks, send_callback);
+    /* nghttp2_on_frame_recv_callback */
+    nghttp2_session_callbacks_set_on_frame_recv_callback
+      (callbacks, on_frame_recv);
+    /* nghttp2_on_invalid_frame_recv_callback */
+    nghttp2_session_callbacks_set_on_invalid_frame_recv_callback
+      (callbacks, on_invalid_frame_recv);
+    /* nghttp2_on_data_chunk_recv_callback */
+    nghttp2_session_callbacks_set_on_data_chunk_recv_callback
+      (callbacks, on_data_chunk_recv);
+    /* nghttp2_before_frame_send_callback */
+    nghttp2_session_callbacks_set_before_frame_send_callback
+      (callbacks, before_frame_send);
+    /* nghttp2_on_frame_send_callback */
+    nghttp2_session_callbacks_set_on_frame_send_callback
+      (callbacks, on_frame_send);
+    /* nghttp2_on_frame_not_send_callback */
+    nghttp2_session_callbacks_set_on_frame_not_send_callback
+      (callbacks, on_frame_not_send);
+    /* nghttp2_on_stream_close_callback */
+    nghttp2_session_callbacks_set_on_stream_close_callback
+      (callbacks, on_stream_close);
+    /* nghttp2_on_begin_headers_callback */
+    nghttp2_session_callbacks_set_on_begin_headers_callback
+      (callbacks, on_begin_headers);
+    /* nghttp2_on_header_callback */
+    nghttp2_session_callbacks_set_on_header_callback(callbacks, on_header);
+
+    /* The nghttp2 session is not yet setup, do it */
+    rc = nghttp2_session_client_new(&conn->proto.httpc.h2,
+                                    callbacks, conn);
+
+    nghttp2_session_callbacks_del(callbacks);
+
+    if(rc) {
+      failf(conn->data, "Couldn't initialize nghttp2!");
+      return CURLE_OUT_OF_MEMORY; /* most likely at least */
+    }
+  }
+  return CURLE_OK;
+}
+
+/*
+ * Send a request using http2
+ */
+CURLcode Curl_http2_send_request(struct connectdata *conn)
+{
+  (void)conn;
+  return CURLE_OK;
+}
+
+/*
+ * Append headers to ask for a HTTP1.1 to HTTP2 upgrade.
+ */
+CURLcode Curl_http2_request_upgrade(Curl_send_buffer *req,
+                                    struct connectdata *conn)
+{
+  CURLcode result;
+  ssize_t binlen;
+  char *base64;
+  size_t blen;
+  struct SingleRequest *k = &conn->data->req;
+  uint8_t *binsettings = conn->proto.httpc.binsettings;
+
+  result = Curl_http2_init(conn);
+  if(result)
+    return result;
+
+  result = Curl_http2_setup(conn);
+  if(result)
+    return result;
+
+  /* As long as we have a fixed set of settings, we don't have to dynamically
+   * figure out the base64 strings since it'll always be the same. However,
+   * the settings will likely not be fixed every time in the future.
+   */
+
+  /* this returns number of bytes it wrote */
+  binlen = nghttp2_pack_settings_payload(binsettings, H2_BINSETTINGS_LEN,
+                                         settings,
+                                         sizeof(settings)/sizeof(settings[0]));
+  if(!binlen) {
+    failf(conn->data, "nghttp2 unexpectedly failed on pack_settings_payload");
+    return CURLE_FAILED_INIT;
+  }
+  conn->proto.httpc.binlen = binlen;
+
+  result = Curl_base64url_encode(conn->data, (const char *)binsettings, binlen,
+                                 &base64, &blen);
+  if(result)
+    return result;
+
+  result = Curl_add_bufferf(req,
+                            "Connection: Upgrade, HTTP2-Settings\r\n"
+                            "Upgrade: %s\r\n"
+                            "HTTP2-Settings: %s\r\n",
+                            NGHTTP2_CLEARTEXT_PROTO_VERSION_ID, base64);
+  Curl_safefree(base64);
+
+  k->upgr101 = UPGR101_REQUESTED;
+
+  return result;
+}
+
+/*
+ * If the read would block (EWOULDBLOCK) we return -1. Otherwise we return
+ * a regular CURLcode value.
+ */
+static ssize_t http2_recv(struct connectdata *conn, int sockindex,
+                          char *mem, size_t len, CURLcode *err)
+{
+  CURLcode rc;
+  ssize_t rv;
+  ssize_t nread;
+  struct http_conn *httpc = &conn->proto.httpc;
+
+  (void)sockindex; /* we always do HTTP2 on sockindex 0 */
+
+  if(httpc->closed) {
+    /* Reset to FALSE to prevent infinite loop in readwrite_data
+       function. */
+    httpc->closed = FALSE;
+    return 0;
+  }
+
+  /* Nullify here because we call nghttp2_session_send() and they
+     might refer to the old buffer. */
+  httpc->upload_mem = NULL;
+  httpc->upload_len = 0;
+
+  if(httpc->bodystarted &&
+     httpc->nread_header_recvbuf < httpc->header_recvbuf->size_used) {
+    size_t left =
+      httpc->header_recvbuf->size_used - httpc->nread_header_recvbuf;
+    size_t ncopy = len < left ? len : left;
+    memcpy(mem, httpc->header_recvbuf->buffer + httpc->nread_header_recvbuf,
+           ncopy);
+    httpc->nread_header_recvbuf += ncopy;
+    return ncopy;
+  }
+
+  if(httpc->data) {
+    nread = len < httpc->datalen ? len : httpc->datalen;
+    memcpy(mem, httpc->data, nread);
+
+    httpc->data += nread;
+    httpc->datalen -= nread;
+
+    infof(conn->data, "%zu data written\n", nread);
+    if(httpc->datalen == 0) {
+      httpc->data = NULL;
+      httpc->datalen = 0;
+    }
+    return nread;
+  }
+
+  conn->proto.httpc.mem = mem;
+  conn->proto.httpc.len = len;
+
+  infof(conn->data, "http2_recv: %d bytes buffer\n",
+        conn->proto.httpc.len);
+
+  rc = 0;
+  nread = ((Curl_recv*)httpc->recv_underlying)(conn, FIRSTSOCKET,
+                                               httpc->inbuf, H2_BUFSIZE, &rc);
+
+  if(rc == CURLE_AGAIN) {
+    *err = rc;
+    return -1;
+  }
+
+  if(nread == -1) {
+    failf(conn->data, "Failed receiving HTTP2 data");
+    *err = rc;
+    return 0;
+  }
+
+  infof(conn->data, "nread=%zd\n", nread);
+  rv = nghttp2_session_mem_recv(httpc->h2,
+                                (const uint8_t *)httpc->inbuf, nread);
+
+  if(nghttp2_is_fatal((int)rv)) {
+    failf(conn->data, "nghttp2_session_mem_recv() returned %d:%s\n",
+          rv, nghttp2_strerror((int)rv));
+    *err = CURLE_RECV_ERROR;
+    return 0;
+  }
+  infof(conn->data, "nghttp2_session_mem_recv() returns %zd\n", rv);
+  /* Always send pending frames in nghttp2 session, because
+     nghttp2_session_mem_recv() may queue new frame */
+  rv = nghttp2_session_send(httpc->h2);
+  if(rv != 0) {
+    *err = CURLE_SEND_ERROR;
+    return 0;
+  }
+  if(len != httpc->len) {
+    return len - conn->proto.httpc.len;
+  }
+  /* If stream is closed, return 0 to signal the http routine to close
+     the connection */
+  if(httpc->closed) {
+    /* Reset to FALSE to prevent infinite loop in readwrite_data
+       function. */
+    httpc->closed = FALSE;
+    return 0;
+  }
+  *err = CURLE_AGAIN;
+  return -1;
+}
+
+/* Index where :authority header field will appear in request header
+   field list. */
+#define AUTHORITY_DST_IDX 3
+
+/* return number of received (decrypted) bytes */
+static ssize_t http2_send(struct connectdata *conn, int sockindex,
+                          const void *mem, size_t len, CURLcode *err)
+{
+  /*
+   * BIG TODO: Currently, we send request in this function, but this
+   * function is also used to send request body. It would be nice to
+   * add dedicated function for request.
+   */
+  int rv;
+  struct http_conn *httpc = &conn->proto.httpc;
+  nghttp2_nv *nva;
+  size_t nheader;
+  size_t i;
+  size_t authority_idx;
+  char *hdbuf = (char*)mem;
+  char *end;
+  nghttp2_data_provider data_prd;
+  int32_t stream_id;
+
+  (void)sockindex;
+
+  infof(conn->data, "http2_send len=%zu\n", len);
+
+  if(httpc->stream_id != -1) {
+    /* If stream_id != -1, we have dispatched request HEADERS, and now
+       are going to send or sending request body in DATA frame */
+    httpc->upload_mem = mem;
+    httpc->upload_len = len;
+    nghttp2_session_resume_data(httpc->h2, httpc->stream_id);
+    rv = nghttp2_session_send(httpc->h2);
+    if(nghttp2_is_fatal(rv)) {
+      *err = CURLE_SEND_ERROR;
+      return -1;
+    }
+    return len - httpc->upload_len;
+  }
+
+  /* Calculate number of headers contained in [mem, mem + len) */
+  /* Here, we assume the curl http code generate *correct* HTTP header
+     field block */
+  nheader = 0;
+  for(i = 0; i < len; ++i) {
+    if(hdbuf[i] == 0x0a) {
+      ++nheader;
+    }
+  }
+  /* We counted additional 2 \n in the first and last line. We need 3
+     new headers: :method, :path and :scheme. Therefore we need one
+     more space. */
+  nheader += 1;
+  nva = malloc(sizeof(nghttp2_nv) * nheader);
+  if(nva == NULL) {
+    *err = CURLE_OUT_OF_MEMORY;
+    return -1;
+  }
+  /* Extract :method, :path from request line */
+  end = strchr(hdbuf, ' ');
+  nva[0].name = (unsigned char *)":method";
+  nva[0].namelen = (uint16_t)strlen((char *)nva[0].name);
+  nva[0].value = (unsigned char *)hdbuf;
+  nva[0].valuelen = (uint16_t)(end - hdbuf);
+  nva[0].flags = NGHTTP2_NV_FLAG_NONE;
+
+  hdbuf = end + 1;
+
+  end = strchr(hdbuf, ' ');
+  nva[1].name = (unsigned char *)":path";
+  nva[1].namelen = (uint16_t)strlen((char *)nva[1].name);
+  nva[1].value = (unsigned char *)hdbuf;
+  nva[1].valuelen = (uint16_t)(end - hdbuf);
+  nva[1].flags = NGHTTP2_NV_FLAG_NONE;
+
+  nva[2].name = (unsigned char *)":scheme";
+  nva[2].namelen = (uint16_t)strlen((char *)nva[2].name);
+  if(conn->handler->flags & PROTOPT_SSL)
+    nva[2].value = (unsigned char *)"https";
+  else
+    nva[2].value = (unsigned char *)"http";
+  nva[2].valuelen = (uint16_t)strlen((char *)nva[2].value);
+  nva[2].flags = NGHTTP2_NV_FLAG_NONE;
+
+  hdbuf = strchr(hdbuf, 0x0a);
+  ++hdbuf;
+
+  authority_idx = 0;
+
+  for(i = 3; i < nheader; ++i) {
+    end = strchr(hdbuf, ':');
+    assert(end);
+    if(end - hdbuf == 4 && Curl_raw_nequal("host", hdbuf, 4)) {
+      authority_idx = i;
+      nva[i].name = (unsigned char *)":authority";
+      nva[i].namelen = (uint16_t)strlen((char *)nva[i].name);
+    }
+    else {
+      nva[i].name = (unsigned char *)hdbuf;
+      nva[i].namelen = (uint16_t)(end - hdbuf);
+    }
+    hdbuf = end + 1;
+    for(; *hdbuf == ' '; ++hdbuf);
+    end = strchr(hdbuf, 0x0d);
+    assert(end);
+    nva[i].value = (unsigned char *)hdbuf;
+    nva[i].valuelen = (uint16_t)(end - hdbuf);
+    nva[i].flags = NGHTTP2_NV_FLAG_NONE;
+
+    hdbuf = end + 2;
+    /* Inspect Content-Length header field and retrieve the request
+       entity length so that we can set END_STREAM to the last DATA
+       frame. */
+    if(nva[i].namelen == 14 &&
+       Curl_raw_nequal("content-length", (char*)nva[i].name, 14)) {
+      size_t j;
+      for(j = 0; j < nva[i].valuelen; ++j) {
+        httpc->upload_left *= 10;
+        httpc->upload_left += nva[i].value[j] - '0';
+      }
+      infof(conn->data, "request content-length=%zu\n", httpc->upload_left);
+    }
+  }
+
+  /* :authority must come before non-pseudo header fields */
+  if(authority_idx != 0 && authority_idx != AUTHORITY_DST_IDX) {
+    nghttp2_nv authority = nva[authority_idx];
+    for(i = authority_idx; i > AUTHORITY_DST_IDX; --i) {
+      nva[i] = nva[i - 1];
+    }
+    nva[i] = authority;
+  }
+
+  switch(conn->data->set.httpreq) {
+  case HTTPREQ_POST:
+  case HTTPREQ_POST_FORM:
+  case HTTPREQ_PUT:
+    data_prd.read_callback = data_source_read_callback;
+    data_prd.source.ptr = NULL;
+    stream_id = nghttp2_submit_request(httpc->h2, NULL, nva, nheader,
+                                       &data_prd, NULL);
+    break;
+  default:
+    stream_id = nghttp2_submit_request(httpc->h2, NULL, nva, nheader,
+                                       NULL, NULL);
+  }
+
+  Curl_safefree(nva);
+
+  if(stream_id < 0) {
+    *err = CURLE_SEND_ERROR;
+    return -1;
+  }
+
+  httpc->stream_id = stream_id;
+
+  rv = nghttp2_session_send(httpc->h2);
+
+  if(rv != 0) {
+    *err = CURLE_SEND_ERROR;
+    return -1;
+  }
+
+  if(httpc->stream_id != -1) {
+    /* If whole HEADERS frame was sent off to the underlying socket,
+       the nghttp2 library calls data_source_read_callback. But only
+       it found that no data available, so it deferred the DATA
+       transmission. Which means that nghttp2_session_want_write()
+       returns 0 on http2_perform_getsock(), which results that no
+       writable socket check is performed. To workaround this, we
+       issue nghttp2_session_resume_data() here to bring back DATA
+       transmission from deferred state. */
+    nghttp2_session_resume_data(httpc->h2, httpc->stream_id);
+  }
+
+  return len;
+}
+
+CURLcode Curl_http2_setup(struct connectdata *conn)
+{
+  struct http_conn *httpc = &conn->proto.httpc;
+  if(conn->handler->flags & PROTOPT_SSL)
+    conn->handler = &Curl_handler_http2_ssl;
+  else
+    conn->handler = &Curl_handler_http2;
+
+  infof(conn->data, "Using HTTP2\n");
+  httpc->bodystarted = FALSE;
+  httpc->closed = FALSE;
+  httpc->header_recvbuf = Curl_add_buffer_init();
+  httpc->nread_header_recvbuf = 0;
+  httpc->data = NULL;
+  httpc->datalen = 0;
+  httpc->upload_left = 0;
+  httpc->upload_mem = NULL;
+  httpc->upload_len = 0;
+  httpc->stream_id = -1;
+  httpc->status_code = -1;
+
+  conn->httpversion = 20;
+
+  return 0;
+}
+
+CURLcode Curl_http2_switched(struct connectdata *conn)
+{
+  CURLcode rc;
+  struct http_conn *httpc = &conn->proto.httpc;
+  int rv;
+  struct SessionHandle *data = conn->data;
+
+  httpc->recv_underlying = (recving)conn->recv[FIRSTSOCKET];
+  httpc->send_underlying = (sending)conn->send[FIRSTSOCKET];
+  conn->recv[FIRSTSOCKET] = http2_recv;
+  conn->send[FIRSTSOCKET] = http2_send;
+
+  rv = (int) ((Curl_send*)httpc->send_underlying)
+    (conn, FIRSTSOCKET,
+     NGHTTP2_CLIENT_CONNECTION_PREFACE,
+     NGHTTP2_CLIENT_CONNECTION_PREFACE_LEN,
+     &rc);
+  if(rc)
+    /* TODO: This may get CURLE_AGAIN */
+    return rc;
+
+  if(rv != 24) {
+    failf(data, "Only sent partial HTTP2 packet");
+    return CURLE_SEND_ERROR;
+  }
+
+  if(conn->data->req.upgr101 == UPGR101_RECEIVED) {
+    /* stream 1 is opened implicitly on upgrade */
+    httpc->stream_id = 1;
+    /* queue SETTINGS frame (again) */
+    rv = nghttp2_session_upgrade(httpc->h2, httpc->binsettings,
+                                 httpc->binlen, NULL);
+    if(rv != 0) {
+      failf(data, "nghttp2_session_upgrade() failed: %s(%d)",
+            nghttp2_strerror(rv), rv);
+      return CURLE_HTTP2;
+    }
+  }
+  else {
+    /* stream ID is unknown at this point */
+    httpc->stream_id = -1;
+    rv = nghttp2_submit_settings(httpc->h2, NGHTTP2_FLAG_NONE, NULL, 0);
+    if(rv != 0) {
+      failf(data, "nghttp2_submit_settings() failed: %s(%d)",
+            nghttp2_strerror(rv), rv);
+      return CURLE_HTTP2;
+    }
+  }
+  return CURLE_OK;
+}
+
+#endif