lib: pass in 'struct Curl_easy *' to most functions

... in most cases instead of 'struct connectdata *' but in some cases in
addition to.

- We mostly operate on transfers and not connections.

- We need the transfer handle to log, store data and more. Everything in
  libcurl is driven by a transfer (the CURL * in the public API).

- This work clarifies and separates the transfers from the connections
  better.

- We should avoid "conn->data". Since individual connections can be used
  by many transfers when multiplexing, making sure that conn->data
  points to the current and correct transfer at all times is difficult
  and has been notoriously error-prone over the years. The goal is to
  ultimately remove the conn->data pointer for this reason.

Closes #6425

2 files changed, 61 insertions, 62 deletions

diff --git a/lib/vquic/ngtcp2.c b/lib/vquic/ngtcp2.c
index 3b401ef15..e1882dafc 100644
--- a/lib/vquic/ngtcp2.c
+++ b/lib/vquic/ngtcp2.c
@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2021, 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
@@ -90,7 +90,7 @@ struct h3out {
 static CURLcode ng_process_ingress(struct connectdata *conn,
                                    curl_socket_t sockfd,
                                    struct quicsocket *qs);
-static CURLcode ng_flush_egress(struct connectdata *conn, int sockfd,
+static CURLcode ng_flush_egress(struct Curl_easy *data, int sockfd,
                                 struct quicsocket *qs);
 static int cb_h3_acked_stream_data(nghttp3_conn *conn, int64_t stream_id,
                                    size_t datalen, void *user_data,
@@ -843,9 +843,10 @@ int Curl_quic_ver(char *p, size_t len)
                    ng2->version_str, ht3->version_str);
 }
 
-static int ng_getsock(struct connectdata *conn, curl_socket_t *socks)
+static int ng_getsock(struct Curl_easy *data, struct connectdata *conn,
+                      curl_socket_t *socks)
 {
-  struct SingleRequest *k = &conn->data->req;
+  struct SingleRequest *k = &data->req;
   int bitmap = GETSOCK_BLANK;
 
   socks[0] = conn->sock[FIRSTSOCKET];
@@ -861,12 +862,6 @@ static int ng_getsock(struct connectdata *conn, curl_socket_t *socks)
   return bitmap;
 }
 
-static int ng_perform_getsock(const struct connectdata *conn,
-                              curl_socket_t *socks)
-{
-  return ng_getsock((struct connectdata *)conn, socks);
-}
-
 static void qs_disconnect(struct quicsocket *qs)
 {
   int i;
@@ -904,18 +899,22 @@ void Curl_quic_disconnect(struct connectdata *conn,
     qs_disconnect(&conn->hequic[tempindex]);
 }
 
-static CURLcode ng_disconnect(struct connectdata *conn,
+static CURLcode ng_disconnect(struct Curl_easy *data,
+                              struct connectdata *conn,
                               bool dead_connection)
 {
   (void)dead_connection;
+  (void)data;
   Curl_quic_disconnect(conn, 0);
   Curl_quic_disconnect(conn, 1);
   return CURLE_OK;
 }
 
-static unsigned int ng_conncheck(struct connectdata *conn,
+static unsigned int ng_conncheck(struct Curl_easy *data,
+                                 struct connectdata *conn,
                                  unsigned int checks_to_perform)
 {
+  (void)data;
   (void)conn;
   (void)checks_to_perform;
   return CONNRESULT_NONE;
@@ -933,7 +932,7 @@ static const struct Curl_handler Curl_handler_http3 = {
   ng_getsock,                           /* proto_getsock */
   ng_getsock,                           /* doing_getsock */
   ZERO_NULL,                            /* domore_getsock */
-  ng_perform_getsock,                   /* perform_getsock */
+  ng_getsock,                           /* perform_getsock */
   ng_disconnect,                        /* disconnect */
   ZERO_NULL,                            /* readwrite */
   ng_conncheck,                         /* connection_check */
@@ -1235,14 +1234,15 @@ static size_t drain_overflow_buffer(struct HTTP *stream)
 }
 
 /* incoming data frames on the h3 stream */
-static ssize_t ngh3_stream_recv(struct connectdata *conn,
+static ssize_t ngh3_stream_recv(struct Curl_easy *data,
                                 int sockindex,
                                 char *buf,
                                 size_t buffersize,
                                 CURLcode *curlcode)
 {
+  struct connectdata *conn = data->conn;
   curl_socket_t sockfd = conn->sock[sockindex];
-  struct HTTP *stream = conn->data->req.p.http;
+  struct HTTP *stream = data->req.p.http;
   struct quicsocket *qs = conn->quic;
 
   if(!stream->memlen) {
@@ -1261,7 +1261,7 @@ static ssize_t ngh3_stream_recv(struct connectdata *conn,
     *curlcode = CURLE_RECV_ERROR;
     return -1;
   }
-  if(ng_flush_egress(conn, sockfd, qs)) {
+  if(ng_flush_egress(data, sockfd, qs)) {
     *curlcode = CURLE_SEND_ERROR;
     return -1;
   }
@@ -1277,7 +1277,7 @@ static ssize_t ngh3_stream_recv(struct connectdata *conn,
     /* extend the stream window with the data we're consuming and send out
        any additional packets to tell the server that we can receive more */
     extend_stream_window(qs->qconn, stream);
-    if(ng_flush_egress(conn, sockfd, qs)) {
+    if(ng_flush_egress(data, sockfd, qs)) {
       *curlcode = CURLE_SEND_ERROR;
       return -1;
     }
@@ -1289,7 +1289,7 @@ static ssize_t ngh3_stream_recv(struct connectdata *conn,
     return 0;
   }
 
-  infof(conn->data, "ngh3_stream_recv returns 0 bytes and EAGAIN\n");
+  infof(data, "ngh3_stream_recv returns 0 bytes and EAGAIN\n");
   *curlcode = CURLE_AGAIN;
   return -1;
 }
@@ -1382,10 +1382,11 @@ static ssize_t cb_h3_readfunction(nghttp3_conn *conn, int64_t stream_id,
    field list. */
 #define AUTHORITY_DST_IDX 3
 
-static CURLcode http_request(struct connectdata *conn, const void *mem,
+static CURLcode http_request(struct Curl_easy *data, const void *mem,
                              size_t len)
 {
-  struct HTTP *stream = conn->data->req.p.http;
+  struct connectdata *conn = data->conn;
+  struct HTTP *stream = data->req.p.http;
   size_t nheader;
   size_t i;
   size_t authority_idx;
@@ -1393,7 +1394,6 @@ static CURLcode http_request(struct connectdata *conn, const void *mem,
   char *end, *line_end;
   struct quicsocket *qs = conn->quic;
   CURLcode result = CURLE_OK;
-  struct Curl_easy *data = conn->data;
   nghttp3_nv *nva = NULL;
   int64_t stream3_id;
   int rc;
@@ -1401,7 +1401,7 @@ static CURLcode http_request(struct connectdata *conn, const void *mem,
 
   rc = ngtcp2_conn_open_bidi_stream(qs->qconn, &stream3_id, NULL);
   if(rc) {
-    failf(conn->data, "can get bidi streams");
+    failf(data, "can get bidi streams");
     result = CURLE_SEND_ERROR;
     goto fail;
   }
@@ -1587,8 +1587,7 @@ static CURLcode http_request(struct connectdata *conn, const void *mem,
     stream->h3out = h3out;
 
     rc = nghttp3_conn_submit_request(qs->h3conn, stream->stream3_id,
-                                     nva, nheader, &data_reader,
-                                     conn->data);
+                                     nva, nheader, &data_reader, data);
     if(rc) {
       result = CURLE_SEND_ERROR;
       goto fail;
@@ -1598,9 +1597,7 @@ static CURLcode http_request(struct connectdata *conn, const void *mem,
   default:
     stream->upload_left = 0; /* nothing left to send */
     rc = nghttp3_conn_submit_request(qs->h3conn, stream->stream3_id,
-                                     nva, nheader,
-                                     NULL, /* no body! */
-                                     conn->data);
+                                     nva, nheader, NULL, data);
     if(rc) {
       result = CURLE_SEND_ERROR;
       goto fail;
@@ -1619,19 +1616,20 @@ fail:
   free(nva);
   return result;
 }
-static ssize_t ngh3_stream_send(struct connectdata *conn,
+static ssize_t ngh3_stream_send(struct Curl_easy *data,
                                 int sockindex,
                                 const void *mem,
                                 size_t len,
                                 CURLcode *curlcode)
 {
   ssize_t sent;
+  struct connectdata *conn = data->conn;
   struct quicsocket *qs = conn->quic;
   curl_socket_t sockfd = conn->sock[sockindex];
-  struct HTTP *stream = conn->data->req.p.http;
+  struct HTTP *stream = data->req.p.http;
 
   if(!stream->h3req) {
-    CURLcode result = http_request(conn, mem, len);
+    CURLcode result = http_request(data, mem, len);
     if(result) {
       *curlcode = CURLE_SEND_ERROR;
       return -1;
@@ -1639,7 +1637,7 @@ static ssize_t ngh3_stream_send(struct connectdata *conn,
     sent = len;
   }
   else {
-    H3BUGF(infof(conn->data, "ngh3_stream_send() wants to send %zd bytes\n",
+    H3BUGF(infof(data, "ngh3_stream_send() wants to send %zd bytes\n",
                  len));
     if(!stream->upload_len) {
       stream->upload_mem = mem;
@@ -1653,7 +1651,7 @@ static ssize_t ngh3_stream_send(struct connectdata *conn,
     }
   }
 
-  if(ng_flush_egress(conn, sockfd, qs)) {
+  if(ng_flush_egress(data, sockfd, qs)) {
     *curlcode = CURLE_SEND_ERROR;
     return -1;
   }
@@ -1689,7 +1687,7 @@ CURLcode Curl_quic_is_connected(struct connectdata *conn,
   if(result)
     goto error;
 
-  result = ng_flush_egress(conn, sockfd, qs);
+  result = ng_flush_egress(conn->data, sockfd, qs);
   if(result)
     goto error;
 
@@ -1749,7 +1747,8 @@ static CURLcode ng_process_ingress(struct connectdata *conn,
   return CURLE_OK;
 }
 
-static CURLcode ng_flush_egress(struct connectdata *conn, int sockfd,
+static CURLcode ng_flush_egress(struct Curl_easy *data,
+                                int sockfd,
                                 struct quicsocket *qs)
 {
   int rv;
@@ -1783,7 +1782,7 @@ static CURLcode ng_flush_egress(struct connectdata *conn, int sockfd,
 
   rv = ngtcp2_conn_handle_expiry(qs->qconn, ts);
   if(rv != 0) {
-    failf(conn->data, "ngtcp2_conn_handle_expiry returned error: %s",
+    failf(data, "ngtcp2_conn_handle_expiry returned error: %s",
           ngtcp2_strerror(rv));
     return CURLE_SEND_ERROR;
   }
@@ -1796,7 +1795,7 @@ static CURLcode ng_flush_egress(struct connectdata *conn, int sockfd,
       veccnt = nghttp3_conn_writev_stream(qs->h3conn, &stream_id, &fin, vec,
                                           sizeof(vec) / sizeof(vec[0]));
       if(veccnt < 0) {
-        failf(conn->data, "nghttp3_conn_writev_stream returned error: %s",
+        failf(data, "nghttp3_conn_writev_stream returned error: %s",
               nghttp3_strerror((int)veccnt));
         return CURLE_SEND_ERROR;
       }
@@ -1817,7 +1816,7 @@ static CURLcode ng_flush_egress(struct connectdata *conn, int sockfd,
             assert(ndatalen == -1);
             rv = nghttp3_conn_block_stream(qs->h3conn, stream_id);
             if(rv != 0) {
-              failf(conn->data,
+              failf(data,
                     "nghttp3_conn_block_stream returned error: %s\n",
                     nghttp3_strerror(rv));
               return CURLE_SEND_ERROR;
@@ -1829,7 +1828,7 @@ static CURLcode ng_flush_egress(struct connectdata *conn, int sockfd,
             rv = nghttp3_conn_add_write_offset(qs->h3conn, stream_id,
                                                ndatalen);
             if(rv != 0) {
-              failf(conn->data,
+              failf(data,
                     "nghttp3_conn_add_write_offset returned error: %s\n",
                     nghttp3_strerror(rv));
               return CURLE_SEND_ERROR;
@@ -1838,7 +1837,7 @@ static CURLcode ng_flush_egress(struct connectdata *conn, int sockfd,
           }
           else {
             assert(ndatalen == -1);
-            failf(conn->data, "ngtcp2_conn_writev_stream returned error: %s",
+            failf(data, "ngtcp2_conn_writev_stream returned error: %s",
                   ngtcp2_strerror((int)outlen));
             return CURLE_SEND_ERROR;
           }
@@ -1852,7 +1851,7 @@ static CURLcode ng_flush_egress(struct connectdata *conn, int sockfd,
       outlen = ngtcp2_conn_write_pkt(qs->qconn, &ps.path, NULL,
                                      out, pktlen, ts);
       if(outlen < 0) {
-        failf(conn->data, "ngtcp2_conn_write_pkt returned error: %s",
+        failf(data, "ngtcp2_conn_write_pkt returned error: %s",
               ngtcp2_strerror((int)outlen));
         return CURLE_SEND_ERROR;
       }
@@ -1871,7 +1870,7 @@ static CURLcode ng_flush_egress(struct connectdata *conn, int sockfd,
         break;
       }
       else {
-        failf(conn->data, "send() returned %zd (errno %d)", sent,
+        failf(data, "send() returned %zd (errno %d)", sent,
               SOCKERRNO);
         return CURLE_SEND_ERROR;
       }
@@ -1886,7 +1885,7 @@ static CURLcode ng_flush_egress(struct connectdata *conn, int sockfd,
     else {
       timeout = expiry - ts;
     }
-    Curl_expire(conn->data, timeout / NGTCP2_MILLISECONDS, EXPIRE_QUIC);
+    Curl_expire(data, timeout / NGTCP2_MILLISECONDS, EXPIRE_QUIC);
   }
 
   return CURLE_OK;
diff --git a/lib/vquic/quiche.c b/lib/vquic/quiche.c
index a66b66447..5601428e9 100644
--- a/lib/vquic/quiche.c
+++ b/lib/vquic/quiche.c
@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2021, 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
@@ -65,9 +65,10 @@ static CURLcode http_request(struct connectdata *conn, const void *mem,
 static Curl_recv h3_stream_recv;
 static Curl_send h3_stream_send;
 
-static int quiche_getsock(struct connectdata *conn, curl_socket_t *socks)
+static int quiche_getsock(struct Curl_easy *data,
+                          struct connectdata *conn, curl_socket_t *socks)
 {
-  struct SingleRequest *k = &conn->data->req;
+  struct SingleRequest *k = &data->req;
   int bitmap = GETSOCK_BLANK;
 
   socks[0] = conn->sock[FIRSTSOCKET];
@@ -83,12 +84,6 @@ static int quiche_getsock(struct connectdata *conn, curl_socket_t *socks)
   return bitmap;
 }
 
-static int quiche_perform_getsock(const struct connectdata *conn,
-                                  curl_socket_t *socks)
-{
-  return quiche_getsock((struct connectdata *)conn, socks);
-}
-
 static CURLcode qs_disconnect(struct connectdata *conn,
                               struct quicsocket *qs)
 {
@@ -111,10 +106,12 @@ static CURLcode qs_disconnect(struct connectdata *conn,
   return CURLE_OK;
 }
 
-static CURLcode quiche_disconnect(struct connectdata *conn,
+static CURLcode quiche_disconnect(struct Curl_easy *data,
+                                  struct connectdata *conn,
                                   bool dead_connection)
 {
   struct quicsocket *qs = conn->quic;
+  (void)data;
   (void)dead_connection;
   return qs_disconnect(conn, qs);
 }
@@ -126,19 +123,21 @@ void Curl_quic_disconnect(struct connectdata *conn,
     qs_disconnect(conn, &conn->hequic[tempindex]);
 }
 
-static unsigned int quiche_conncheck(struct connectdata *conn,
+static unsigned int quiche_conncheck(struct Curl_easy *data,
+                                     struct connectdata *conn,
                                      unsigned int checks_to_perform)
 {
+  (void)data;
   (void)conn;
   (void)checks_to_perform;
   return CONNRESULT_NONE;
 }
 
-static CURLcode quiche_do(struct connectdata *conn, bool *done)
+static CURLcode quiche_do(struct Curl_easy *data, bool *done)
 {
-  struct HTTP *stream = conn->data->req.p.http;
+  struct HTTP *stream = data->req.p.http;
   stream->h3req = FALSE; /* not sent */
-  return Curl_http(conn, done);
+  return Curl_http(data, done);
 }
 
 static const struct Curl_handler Curl_handler_http3 = {
@@ -153,7 +152,7 @@ static const struct Curl_handler Curl_handler_http3 = {
   quiche_getsock,                       /* proto_getsock */
   quiche_getsock,                       /* doing_getsock */
   ZERO_NULL,                            /* domore_getsock */
-  quiche_perform_getsock,               /* perform_getsock */
+  quiche_getsock,                       /* perform_getsock */
   quiche_disconnect,                    /* disconnect */
   ZERO_NULL,                            /* readwrite */
   quiche_conncheck,                     /* connection_check */
@@ -256,7 +255,7 @@ CURLcode Curl_quic_connect(struct connectdata *conn, curl_socket_t sockfd,
     return CURLE_BAD_FUNCTION_ARGUMENT;
   }
   memcpy(conn->ip_addr_str, conn->primary_ip, MAX_IPADR_LEN);
-  Curl_persistconninfo(conn);
+  Curl_persistconninfo(data, conn);
 
   /* for connection reuse purposes: */
   conn->ssl[FIRSTSOCKET].state = ssl_connection_complete;
@@ -453,7 +452,7 @@ static int cb_each_header(uint8_t *name, size_t name_len,
   return 0;
 }
 
-static ssize_t h3_stream_recv(struct connectdata *conn,
+static ssize_t h3_stream_recv(struct Curl_easy *data,
                               int sockindex,
                               char *buf,
                               size_t buffersize,
@@ -461,12 +460,12 @@ static ssize_t h3_stream_recv(struct connectdata *conn,
 {
   ssize_t recvd = -1;
   ssize_t rcode;
+  struct connectdata *conn = data->conn;
   struct quicsocket *qs = conn->quic;
   curl_socket_t sockfd = conn->sock[sockindex];
   quiche_h3_event *ev;
   int rc;
   struct h3h1header headers;
-  struct Curl_easy *data = conn->data;
   struct HTTP *stream = data->req.p.http;
   headers.dest = buf;
   headers.destlen = buffersize;
@@ -546,16 +545,17 @@ static ssize_t h3_stream_recv(struct connectdata *conn,
   return recvd;
 }
 
-static ssize_t h3_stream_send(struct connectdata *conn,
+static ssize_t h3_stream_send(struct Curl_easy *data,
                               int sockindex,
                               const void *mem,
                               size_t len,
                               CURLcode *curlcode)
 {
   ssize_t sent;
+  struct connectdata *conn = data->conn;
   struct quicsocket *qs = conn->quic;
   curl_socket_t sockfd = conn->sock[sockindex];
-  struct HTTP *stream = conn->data->req.p.http;
+  struct HTTP *stream = data->req.p.http;
 
   if(!stream->h3req) {
     CURLcode result = http_request(conn, mem, len);