lib: remove 'conn->data' completelybagder/conn-data-is-gone

The Curl_easy pointer struct entry in connectdata is now gone.

7 files changed, 26 insertions, 79 deletions

diff --git a/lib/conncache.c b/lib/conncache.c
index 8dfdc0ac8..5453c00f3 100644
--- a/lib/conncache.c
+++ b/lib/conncache.c
@@ -466,7 +466,6 @@ Curl_conncache_extract_bundle(struct Curl_easy *data,
     data->state.conn_cache->num_conn--;
     DEBUGF(infof(data, "The cache now contains %zu members\n",
                  data->state.conn_cache->num_conn));
-    conn_candidate->data = data; /* associate! */
   }
 
   return conn_candidate;
@@ -529,7 +528,6 @@ Curl_conncache_extract_oldest(struct Curl_easy *data)
     connc->num_conn--;
     DEBUGF(infof(data, "The cache now contains %zu members\n",
                  connc->num_conn));
-    conn_candidate->data = data; /* associate! */
   }
   CONNCACHE_UNLOCK(data);
 
diff --git a/lib/connect.c b/lib/connect.c
index 0bcfac325..6c9464360 100644
--- a/lib/connect.c
+++ b/lib/connect.c
@@ -1448,11 +1448,9 @@ curl_socket_t Curl_getconnectinfo(struct Curl_easy *data,
     }
 
     c = find.found;
-    if(connp) {
+    if(connp)
       /* only store this if the caller cares for it */
       *connp = c;
-      c->data = data;
-    }
     return c->sock[FIRSTSOCKET];
   }
   return CURL_SOCKET_BAD;
diff --git a/lib/easy.c b/lib/easy.c
index 0fb255af4..fd4123bed 100644
--- a/lib/easy.c
+++ b/lib/easy.c
@@ -1052,8 +1052,6 @@ CURLcode curl_easy_pause(struct Curl_easy *data, int action)
       unsigned int i;
       unsigned int count = data->state.tempcount;
       struct tempbuf writebuf[3]; /* there can only be three */
-      struct connectdata *conn = data->conn;
-      struct Curl_easy *saved_data = NULL;
 
       /* copy the structs to allow for immediate re-pausing */
       for(i = 0; i < data->state.tempcount; i++) {
@@ -1062,12 +1060,6 @@ CURLcode curl_easy_pause(struct Curl_easy *data, int action)
       }
       data->state.tempcount = 0;
 
-      /* set the connection's current owner */
-      if(conn->data != data) {
-        saved_data = conn->data;
-        conn->data = data;
-      }
-
       for(i = 0; i < count; i++) {
         /* even if one function returns error, this loops through and frees
            all buffers */
@@ -1078,10 +1070,6 @@ CURLcode curl_easy_pause(struct Curl_easy *data, int action)
         Curl_dyn_free(&writebuf[i].b);
       }
 
-      /* recover previous owner of the connection */
-      if(saved_data)
-        conn->data = saved_data;
-
       if(result)
         return result;
     }
diff --git a/lib/multi.c b/lib/multi.c
index bae8398bc..7bea2aba4 100644
--- a/lib/multi.c
+++ b/lib/multi.c
@@ -562,8 +562,6 @@ static CURLcode multi_done(struct Curl_easy *data,
     /* Stop if multi_done() has already been called */
     return CURLE_OK;
 
-  conn->data = data; /* ensure the connection uses this transfer now */
-
   /* Stop the resolver and free its own resources (but not dns_entry yet). */
   Curl_resolver_kill(data);
 
@@ -604,16 +602,13 @@ static CURLcode multi_done(struct Curl_easy *data,
   Curl_detach_connnection(data);
   if(CONN_INUSE(conn)) {
     /* Stop if still used. */
-    /* conn->data must not remain pointing to this transfer since it is going
-       away! Find another to own it! */
-    conn->data = conn->easyq.head->ptr;
     CONNCACHE_UNLOCK(data);
     DEBUGF(infof(data, "Connection still in use %zu, "
                  "no more multi_done now!\n",
                  conn->easyq.size));
     return CURLE_OK;
   }
-  conn->data = NULL; /* the connection now has no owner */
+
   data->state.done = TRUE; /* called just now! */
 
   if(conn->dns_entry) {
@@ -718,7 +713,6 @@ CURLMcode curl_multi_remove_handle(struct Curl_multi *multi,
 {
   struct Curl_easy *easy = data;
   bool premature;
-  bool easy_owns_conn;
   struct Curl_llist_element *e;
 
   /* First, make some basic checks that the CURLM handle is a good handle */
@@ -741,8 +735,6 @@ CURLMcode curl_multi_remove_handle(struct Curl_multi *multi,
     return CURLM_RECURSIVE_API_CALL;
 
   premature = (data->mstate < CURLM_STATE_COMPLETED) ? TRUE : FALSE;
-  easy_owns_conn = (data->conn && (data->conn->data == easy)) ?
-    TRUE : FALSE;
 
   /* If the 'state' is not INIT or COMPLETED, we might need to do something
      nice to put the easy_handle in a good known state when this returns. */
@@ -757,24 +749,16 @@ CURLMcode curl_multi_remove_handle(struct Curl_multi *multi,
      data->mstate < CURLM_STATE_COMPLETED) {
     /* Set connection owner so that the DONE function closes it.  We can
        safely do this here since connection is killed. */
-    data->conn->data = easy;
     streamclose(data->conn, "Removed with partial response");
-    easy_owns_conn = TRUE;
   }
 
   if(data->conn) {
+    /* multi_done() clears the association between the easy handle and the
+       connection.
 
-    /* we must call multi_done() here (if we still own the connection) so that
-       we don't leave a half-baked one around */
-    if(easy_owns_conn) {
-
-      /* multi_done() clears the association between the easy handle and the
-         connection.
-
-         Note that this ignores the return code simply because there's
-         nothing really useful to do with it anyway! */
-      (void)multi_done(data, data->result, premature);
-    }
+       Note that this ignores the return code simply because there's
+       nothing really useful to do with it anyway! */
+    (void)multi_done(data, data->result, premature);
   }
 
   /* The timer must be shut down before data->multi is set to NULL, else the
@@ -984,12 +968,6 @@ static int multi_getsock(struct Curl_easy *data,
   if(!conn)
     return 0;
 
-  if(data->mstate > CURLM_STATE_CONNECT &&
-     data->mstate < CURLM_STATE_COMPLETED) {
-    /* Set up ownership correctly */
-    data->conn->data = data;
-  }
-
   switch(data->mstate) {
   default:
     return 0;
@@ -1397,7 +1375,6 @@ static CURLcode multi_do(struct Curl_easy *data, bool *done)
 
   DEBUGASSERT(conn);
   DEBUGASSERT(conn->handler);
-  DEBUGASSERT(conn->data == data);
 
   if(conn->handler->do_it)
     /* generic protocol-specific function pointer set in curl_connect() */
@@ -1584,7 +1561,6 @@ static CURLMcode multi_runsingle(struct Curl_multi *multi,
       DEBUGASSERT(data->conn);
       if(!data->conn)
         return CURLM_INTERNAL_ERROR;
-      data->conn->data = data;
     }
 
     if(data->conn &&
diff --git a/lib/url.c b/lib/url.c
index 442760273..ae6c8e9c1 100644
--- a/lib/url.c
+++ b/lib/url.c
@@ -992,12 +992,12 @@ static bool extract_if_dead(struct connectdata *conn,
       /* briefly attach the connection to this transfer for the purpose of
          checking it */
       Curl_attach_connnection(data, conn);
-      conn->data = data; /* find the way back if necessary */
+
       state = conn->handler->connection_check(data, conn, CONNCHECK_ISDEAD);
       dead = (state & CONNRESULT_DEAD);
       /* detach the connection again */
       Curl_detach_connnection(data);
-      conn->data = NULL; /* clear it again */
+
     }
     else {
       /* Use the general method for determining the death of a connection */
@@ -1098,13 +1098,13 @@ ConnectionExists(struct Curl_easy *data,
 
 #ifdef USE_NTLM
   bool wantNTLMhttp = ((data->state.authhost.want &
-                      (CURLAUTH_NTLM | CURLAUTH_NTLM_WB)) &&
-                      (needle->handler->protocol & PROTO_FAMILY_HTTP));
+                        (CURLAUTH_NTLM | CURLAUTH_NTLM_WB)) &&
+                       (needle->handler->protocol & PROTO_FAMILY_HTTP));
 #ifndef CURL_DISABLE_PROXY
   bool wantProxyNTLMhttp = (needle->bits.proxy_user_passwd &&
-                           ((data->state.authproxy.want &
-                           (CURLAUTH_NTLM | CURLAUTH_NTLM_WB)) &&
-                           (needle->handler->protocol & PROTO_FAMILY_HTTP)));
+                            ((data->state.authproxy.want &
+                              (CURLAUTH_NTLM | CURLAUTH_NTLM_WB)) &&
+                             (needle->handler->protocol & PROTO_FAMILY_HTTP)));
 #else
   bool wantProxyNTLMhttp = FALSE;
 #endif
@@ -1272,17 +1272,19 @@ ConnectionExists(struct Curl_easy *data,
       }
 #endif
 
-      DEBUGASSERT(!check->data || GOOD_EASY_HANDLE(check->data));
-
-      if(!canmultiplex && check->data)
+      if(!canmultiplex && CONN_INUSE(check))
         /* this request can't be multiplexed but the checked connection is
            already in use so we skip it */
         continue;
 
-      if(check->data && (check->data->multi != needle->data->multi))
-        /* this could be subject for multiplex use, but only if they belong to
-         * the same multi handle */
-        continue;
+      if(CONN_INUSE(check)) {
+        /* Subject for multiplex use if 'checks' belongs to the same multi
+           handle as 'data' is. */
+        struct Curl_llist_element *e = check->easyq.head;
+        struct Curl_easy *entry = e->ptr;
+        if(entry->multi != data->multi)
+          continue;
+      }
 
       if(needle->localdev || needle->localport) {
         /* If we are bound to a specific local end (IP+port), we must not
@@ -1441,7 +1443,7 @@ ConnectionExists(struct Curl_easy *data,
               continue;
             }
             else if(multiplexed >=
-                    Curl_multi_max_concurrent_streams(needle->data->multi)) {
+                    Curl_multi_max_concurrent_streams(data->multi)) {
               infof(data, "client side MAX_CONCURRENT_STREAMS reached"
                     ", skip (%zu)\n",
                     multiplexed);
@@ -1465,7 +1467,6 @@ ConnectionExists(struct Curl_easy *data,
 
   if(chosen) {
     /* mark it as used before releasing the lock */
-    chosen->data = data; /* own it! */
     Curl_attach_connnection(data, chosen);
     CONNCACHE_UNLOCK(data);
     *usethis = chosen;
@@ -1680,9 +1681,6 @@ static struct connectdata *allocate_conn(struct Curl_easy *data)
   /* Store current time to give a baseline to keepalive connection times. */
   conn->keepalive = Curl_now();
 
-  conn->data = data; /* Setup the association between this connection
-                        and the Curl_easy */
-
 #ifndef CURL_DISABLE_PROXY
   conn->http_proxy.proxytype = data->set.proxytype;
   conn->socks_proxy.proxytype = CURLPROXY_SOCKS4;
@@ -3405,8 +3403,6 @@ static void reuse_conn(struct Curl_easy *data,
      allocated in vain and is targeted for destruction */
   Curl_free_primary_ssl_config(&old_conn->ssl_config);
 
-  conn->data = data;
-
   /* get the user+password information from the old_conn struct since it may
    * be new for this request even when we re-use an existing connection */
   conn->bits.user_passwd = old_conn->bits.user_passwd;
@@ -3494,7 +3490,6 @@ static void reuse_conn(struct Curl_easy *data,
  * @param async is set TRUE when an async DNS resolution is pending
  * @see Curl_setup_conn()
  *
- * *NOTE* this function assigns the conn->data pointer!
  */
 
 static CURLcode create_conn(struct Curl_easy *data,
@@ -3976,10 +3971,7 @@ out:
  * create_conn() is all done.
  *
  * Curl_setup_conn() also handles reused connections
- *
- * conn->data MUST already have been setup fine (in create_conn)
  */
-
 CURLcode Curl_setup_conn(struct Curl_easy *data,
                          bool *protocol_done)
 {
diff --git a/lib/urldata.h b/lib/urldata.h
index 6dd029f72..77862f8ad 100644
--- a/lib/urldata.h
+++ b/lib/urldata.h
@@ -911,10 +911,6 @@ struct connstate {
  * unique for an entire connection.
  */
 struct connectdata {
-  /* 'data' is the CURRENT Curl_easy using this connection -- take great
-     caution that this might very well vary between different times this
-     connection is used! */
-  struct Curl_easy *data;
   struct connstate cnnct;
   struct Curl_llist_element bundle_node; /* conncache */
 
diff --git a/lib/vtls/rustls.c b/lib/vtls/rustls.c
index 7e00ce7c0..986faa070 100644
--- a/lib/vtls/rustls.c
+++ b/lib/vtls/rustls.c
@@ -5,7 +5,8 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 2020, Jacob Hoffman-Andrews, <github@hoffman-andrews.com>
+ * Copyright (C) 2020 - 2021, Jacob Hoffman-Andrews,
+ * <github@hoffman-andrews.com>
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -61,10 +62,8 @@ static CURLcode map_error(rustls_result r)
 static bool
 cr_data_pending(const struct connectdata *conn, int sockindex)
 {
-  struct Curl_easy *data = conn->data;
   const struct ssl_connect_data *connssl = &conn->ssl[sockindex];
   struct ssl_backend_data *backend = connssl->backend;
-  infof(data, "rustls_data_pending %d\n", backend->data_pending);
   return backend->data_pending;
 }