init repo.

third_party/curl/lib/conncache.c

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+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) Linus Nielsen Feltzing, <linus@haxx.se>
+ * Copyright (C) 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 https://curl.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.
+ *
+ * SPDX-License-Identifier: curl
+ *
+ ***************************************************************************/
+
+#include "curl_setup.h"
+
+#include <curl/curl.h>
+
+#include "urldata.h"
+#include "url.h"
+#include "progress.h"
+#include "multiif.h"
+#include "sendf.h"
+#include "conncache.h"
+#include "share.h"
+#include "sigpipe.h"
+#include "connect.h"
+#include "strcase.h"
+
+/* The last 3 #include files should be in this order */
+#include "curl_printf.h"
+#include "curl_memory.h"
+#include "memdebug.h"
+
+#define HASHKEY_SIZE 128
+
+static CURLcode bundle_create(struct connectbundle **bundlep)
+{
+  DEBUGASSERT(*bundlep == NULL);
+  *bundlep = malloc(sizeof(struct connectbundle));
+  if(!*bundlep)
+    return CURLE_OUT_OF_MEMORY;
+
+  (*bundlep)->num_connections = 0;
+  (*bundlep)->multiuse = BUNDLE_UNKNOWN;
+
+  Curl_llist_init(&(*bundlep)->conn_list, NULL);
+  return CURLE_OK;
+}
+
+static void bundle_destroy(struct connectbundle *bundle)
+{
+  free(bundle);
+}
+
+/* Add a connection to a bundle */
+static void bundle_add_conn(struct connectbundle *bundle,
+                            struct connectdata *conn)
+{
+  Curl_llist_append(&bundle->conn_list, conn, &conn->bundle_node);
+  conn->bundle = bundle;
+  bundle->num_connections++;
+}
+
+/* Remove a connection from a bundle */
+static int bundle_remove_conn(struct connectbundle *bundle,
+                              struct connectdata *conn)
+{
+  struct Curl_llist_element *curr;
+
+  curr = bundle->conn_list.head;
+  while(curr) {
+    if(curr->ptr == conn) {
+      Curl_llist_remove(&bundle->conn_list, curr, NULL);
+      bundle->num_connections--;
+      conn->bundle = NULL;
+      return 1; /* we removed a handle */
+    }
+    curr = curr->next;
+  }
+  DEBUGASSERT(0);
+  return 0;
+}
+
+static void free_bundle_hash_entry(void *freethis)
+{
+  struct connectbundle *b = (struct connectbundle *) freethis;
+
+  bundle_destroy(b);
+}
+
+int Curl_conncache_init(struct conncache *connc, size_t size)
+{
+  /* allocate a new easy handle to use when closing cached connections */
+  connc->closure_handle = curl_easy_init();
+  if(!connc->closure_handle)
+    return 1; /* bad */
+  connc->closure_handle->state.internal = true;
+
+  Curl_hash_init(&connc->hash, size, Curl_hash_str,
+                 Curl_str_key_compare, free_bundle_hash_entry);
+  connc->closure_handle->state.conn_cache = connc;
+
+  return 0; /* good */
+}
+
+void Curl_conncache_destroy(struct conncache *connc)
+{
+  if(connc)
+    Curl_hash_destroy(&connc->hash);
+}
+
+/* creates a key to find a bundle for this connection */
+static void hashkey(struct connectdata *conn, char *buf, size_t len)
+{
+  const char *hostname;
+  long port = conn->remote_port;
+  DEBUGASSERT(len >= HASHKEY_SIZE);
+#ifndef CURL_DISABLE_PROXY
+  if(conn->bits.httpproxy && !conn->bits.tunnel_proxy) {
+    hostname = conn->http_proxy.host.name;
+    port = conn->primary.remote_port;
+  }
+  else
+#endif
+    if(conn->bits.conn_to_host)
+      hostname = conn->conn_to_host.name;
+  else
+    hostname = conn->host.name;
+
+  /* put the numbers first so that the hostname gets cut off if too long */
+#ifdef USE_IPV6
+  msnprintf(buf, len, "%u/%ld/%s", conn->scope_id, port, hostname);
+#else
+  msnprintf(buf, len, "%ld/%s", port, hostname);
+#endif
+  Curl_strntolower(buf, buf, len);
+}
+
+/* Returns number of connections currently held in the connection cache.
+   Locks/unlocks the cache itself!
+*/
+size_t Curl_conncache_size(struct Curl_easy *data)
+{
+  size_t num;
+  CONNCACHE_LOCK(data);
+  num = data->state.conn_cache->num_conn;
+  CONNCACHE_UNLOCK(data);
+  return num;
+}
+
+/* Look up the bundle with all the connections to the same host this
+   connectdata struct is setup to use.
+
+   **NOTE**: When it returns, it holds the connection cache lock! */
+struct connectbundle *
+Curl_conncache_find_bundle(struct Curl_easy *data,
+                           struct connectdata *conn,
+                           struct conncache *connc)
+{
+  struct connectbundle *bundle = NULL;
+  CONNCACHE_LOCK(data);
+  if(connc) {
+    char key[HASHKEY_SIZE];
+    hashkey(conn, key, sizeof(key));
+    bundle = Curl_hash_pick(&connc->hash, key, strlen(key));
+  }
+
+  return bundle;
+}
+
+static void *conncache_add_bundle(struct conncache *connc,
+                                  char *key,
+                                  struct connectbundle *bundle)
+{
+  return Curl_hash_add(&connc->hash, key, strlen(key), bundle);
+}
+
+static void conncache_remove_bundle(struct conncache *connc,
+                                    struct connectbundle *bundle)
+{
+  struct Curl_hash_iterator iter;
+  struct Curl_hash_element *he;
+
+  if(!connc)
+    return;
+
+  Curl_hash_start_iterate(&connc->hash, &iter);
+
+  he = Curl_hash_next_element(&iter);
+  while(he) {
+    if(he->ptr == bundle) {
+      /* The bundle is destroyed by the hash destructor function,
+         free_bundle_hash_entry() */
+      Curl_hash_delete(&connc->hash, he->key, he->key_len);
+      return;
+    }
+
+    he = Curl_hash_next_element(&iter);
+  }
+}
+
+CURLcode Curl_conncache_add_conn(struct Curl_easy *data)
+{
+  CURLcode result = CURLE_OK;
+  struct connectbundle *bundle = NULL;
+  struct connectdata *conn = data->conn;
+  struct conncache *connc = data->state.conn_cache;
+  DEBUGASSERT(conn);
+
+  /* *find_bundle() locks the connection cache */
+  bundle = Curl_conncache_find_bundle(data, conn, data->state.conn_cache);
+  if(!bundle) {
+    char key[HASHKEY_SIZE];
+
+    result = bundle_create(&bundle);
+    if(result) {
+      goto unlock;
+    }
+
+    hashkey(conn, key, sizeof(key));
+
+    if(!conncache_add_bundle(data->state.conn_cache, key, bundle)) {
+      bundle_destroy(bundle);
+      result = CURLE_OUT_OF_MEMORY;
+      goto unlock;
+    }
+  }
+
+  bundle_add_conn(bundle, conn);
+  conn->connection_id = connc->next_connection_id++;
+  connc->num_conn++;
+
+  DEBUGF(infof(data, "Added connection %" CURL_FORMAT_CURL_OFF_T ". "
+               "The cache now contains %zu members",
+               conn->connection_id, connc->num_conn));
+
+unlock:
+  CONNCACHE_UNLOCK(data);
+
+  return result;
+}
+
+/*
+ * Removes the connectdata object from the connection cache, but the transfer
+ * still owns this connection.
+ *
+ * Pass TRUE/FALSE in the 'lock' argument depending on if the parent function
+ * already holds the lock or not.
+ */
+void Curl_conncache_remove_conn(struct Curl_easy *data,
+                                struct connectdata *conn, bool lock)
+{
+  struct connectbundle *bundle = conn->bundle;
+  struct conncache *connc = data->state.conn_cache;
+
+  /* The bundle pointer can be NULL, since this function can be called
+     due to a failed connection attempt, before being added to a bundle */
+  if(bundle) {
+    if(lock) {
+      CONNCACHE_LOCK(data);
+    }
+    bundle_remove_conn(bundle, conn);
+    if(bundle->num_connections == 0)
+      conncache_remove_bundle(connc, bundle);
+    conn->bundle = NULL; /* removed from it */
+    if(connc) {
+      connc->num_conn--;
+      DEBUGF(infof(data, "The cache now contains %zu members",
+                   connc->num_conn));
+    }
+    if(lock) {
+      CONNCACHE_UNLOCK(data);
+    }
+  }
+}
+
+/* This function iterates the entire connection cache and calls the function
+   func() with the connection pointer as the first argument and the supplied
+   'param' argument as the other.
+
+   The conncache lock is still held when the callback is called. It needs it,
+   so that it can safely continue traversing the lists once the callback
+   returns.
+
+   Returns 1 if the loop was aborted due to the callback's return code.
+
+   Return 0 from func() to continue the loop, return 1 to abort it.
+ */
+bool Curl_conncache_foreach(struct Curl_easy *data,
+                            struct conncache *connc,
+                            void *param,
+                            int (*func)(struct Curl_easy *data,
+                                        struct connectdata *conn, void *param))
+{
+  struct Curl_hash_iterator iter;
+  struct Curl_llist_element *curr;
+  struct Curl_hash_element *he;
+
+  if(!connc)
+    return FALSE;
+
+  CONNCACHE_LOCK(data);
+  Curl_hash_start_iterate(&connc->hash, &iter);
+
+  he = Curl_hash_next_element(&iter);
+  while(he) {
+    struct connectbundle *bundle;
+
+    bundle = he->ptr;
+    he = Curl_hash_next_element(&iter);
+
+    curr = bundle->conn_list.head;
+    while(curr) {
+      /* Yes, we need to update curr before calling func(), because func()
+         might decide to remove the connection */
+      struct connectdata *conn = curr->ptr;
+      curr = curr->next;
+
+      if(1 == func(data, conn, param)) {
+        CONNCACHE_UNLOCK(data);
+        return TRUE;
+      }
+    }
+  }
+  CONNCACHE_UNLOCK(data);
+  return FALSE;
+}
+
+/* Return the first connection found in the cache. Used when closing all
+   connections.
+
+   NOTE: no locking is done here as this is presumably only done when cleaning
+   up a cache!
+*/
+static struct connectdata *
+conncache_find_first_connection(struct conncache *connc)
+{
+  struct Curl_hash_iterator iter;
+  struct Curl_hash_element *he;
+  struct connectbundle *bundle;
+
+  Curl_hash_start_iterate(&connc->hash, &iter);
+
+  he = Curl_hash_next_element(&iter);
+  while(he) {
+    struct Curl_llist_element *curr;
+    bundle = he->ptr;
+
+    curr = bundle->conn_list.head;
+    if(curr) {
+      return curr->ptr;
+    }
+
+    he = Curl_hash_next_element(&iter);
+  }
+
+  return NULL;
+}
+
+/*
+ * Give ownership of a connection back to the connection cache. Might
+ * disconnect the oldest existing in there to make space.
+ *
+ * Return TRUE if stored, FALSE if closed.
+ */
+bool Curl_conncache_return_conn(struct Curl_easy *data,
+                                struct connectdata *conn)
+{
+  unsigned int maxconnects = !data->multi->maxconnects ?
+    data->multi->num_easy * 4: data->multi->maxconnects;
+  struct connectdata *conn_candidate = NULL;
+
+  conn->lastused = Curl_now(); /* it was used up until now */
+  if(maxconnects && Curl_conncache_size(data) > maxconnects) {
+    infof(data, "Connection cache is full, closing the oldest one");
+
+    conn_candidate = Curl_conncache_extract_oldest(data);
+    if(conn_candidate) {
+      /* Use the closure handle for this disconnect so that anything that
+         happens during the disconnect is not stored and associated with the
+         'data' handle which already just finished a transfer and it is
+         important that details from this (unrelated) disconnect does not
+         taint meta-data in the data handle. */
+      struct conncache *connc = data->state.conn_cache;
+      Curl_disconnect(connc->closure_handle, conn_candidate,
+                      /* dead_connection */ FALSE);
+    }
+  }
+
+  return (conn_candidate == conn) ? FALSE : TRUE;
+
+}
+
+/*
+ * This function finds the connection in the connection bundle that has been
+ * unused for the longest time.
+ *
+ * Does not lock the connection cache!
+ *
+ * Returns the pointer to the oldest idle connection, or NULL if none was
+ * found.
+ */
+struct connectdata *
+Curl_conncache_extract_bundle(struct Curl_easy *data,
+                              struct connectbundle *bundle)
+{
+  struct Curl_llist_element *curr;
+  timediff_t highscore = -1;
+  timediff_t score;
+  struct curltime now;
+  struct connectdata *conn_candidate = NULL;
+  struct connectdata *conn;
+
+  (void)data;
+
+  now = Curl_now();
+
+  curr = bundle->conn_list.head;
+  while(curr) {
+    conn = curr->ptr;
+
+    if(!CONN_INUSE(conn)) {
+      /* Set higher score for the age passed since the connection was used */
+      score = Curl_timediff(now, conn->lastused);
+
+      if(score > highscore) {
+        highscore = score;
+        conn_candidate = conn;
+      }
+    }
+    curr = curr->next;
+  }
+  if(conn_candidate) {
+    /* remove it to prevent another thread from nicking it */
+    bundle_remove_conn(bundle, conn_candidate);
+    data->state.conn_cache->num_conn--;
+    DEBUGF(infof(data, "The cache now contains %zu members",
+                 data->state.conn_cache->num_conn));
+  }
+
+  return conn_candidate;
+}
+
+/*
+ * This function finds the connection in the connection cache that has been
+ * unused for the longest time and extracts that from the bundle.
+ *
+ * Returns the pointer to the connection, or NULL if none was found.
+ */
+struct connectdata *
+Curl_conncache_extract_oldest(struct Curl_easy *data)
+{
+  struct conncache *connc = data->state.conn_cache;
+  struct Curl_hash_iterator iter;
+  struct Curl_llist_element *curr;
+  struct Curl_hash_element *he;
+  timediff_t highscore =- 1;
+  timediff_t score;
+  struct curltime now;
+  struct connectdata *conn_candidate = NULL;
+  struct connectbundle *bundle;
+  struct connectbundle *bundle_candidate = NULL;
+
+  now = Curl_now();
+
+  CONNCACHE_LOCK(data);
+  Curl_hash_start_iterate(&connc->hash, &iter);
+
+  he = Curl_hash_next_element(&iter);
+  while(he) {
+    struct connectdata *conn;
+
+    bundle = he->ptr;
+
+    curr = bundle->conn_list.head;
+    while(curr) {
+      conn = curr->ptr;
+
+      if(!CONN_INUSE(conn) && !conn->bits.close &&
+         !conn->connect_only) {
+        /* Set higher score for the age passed since the connection was used */
+        score = Curl_timediff(now, conn->lastused);
+
+        if(score > highscore) {
+          highscore = score;
+          conn_candidate = conn;
+          bundle_candidate = bundle;
+        }
+      }
+      curr = curr->next;
+    }
+
+    he = Curl_hash_next_element(&iter);
+  }
+  if(conn_candidate) {
+    /* remove it to prevent another thread from nicking it */
+    bundle_remove_conn(bundle_candidate, conn_candidate);
+    connc->num_conn--;
+    DEBUGF(infof(data, "The cache now contains %zu members",
+                 connc->num_conn));
+  }
+  CONNCACHE_UNLOCK(data);
+
+  return conn_candidate;
+}
+
+void Curl_conncache_close_all_connections(struct conncache *connc)
+{
+  struct connectdata *conn;
+  SIGPIPE_VARIABLE(pipe_st);
+  if(!connc->closure_handle)
+    return;
+
+  conn = conncache_find_first_connection(connc);
+  while(conn) {
+    sigpipe_ignore(connc->closure_handle, &pipe_st);
+    /* This will remove the connection from the cache */
+    connclose(conn, "kill all");
+    Curl_conncache_remove_conn(connc->closure_handle, conn, TRUE);
+    Curl_disconnect(connc->closure_handle, conn, FALSE);
+    sigpipe_restore(&pipe_st);
+
+    conn = conncache_find_first_connection(connc);
+  }
+
+  sigpipe_ignore(connc->closure_handle, &pipe_st);
+
+  Curl_hostcache_clean(connc->closure_handle,
+                       connc->closure_handle->dns.hostcache);
+  Curl_close(&connc->closure_handle);
+  sigpipe_restore(&pipe_st);
+}
+
+#if 0
+/* Useful for debugging the connection cache */
+void Curl_conncache_print(struct conncache *connc)
+{
+  struct Curl_hash_iterator iter;
+  struct Curl_llist_element *curr;
+  struct Curl_hash_element *he;
+
+  if(!connc)
+    return;
+
+  fprintf(stderr, "=Bundle cache=\n");
+
+  Curl_hash_start_iterate(connc->hash, &iter);
+
+  he = Curl_hash_next_element(&iter);
+  while(he) {
+    struct connectbundle *bundle;
+    struct connectdata *conn;
+
+    bundle = he->ptr;
+
+    fprintf(stderr, "%s -", he->key);
+    curr = bundle->conn_list->head;
+    while(curr) {
+      conn = curr->ptr;
+
+      fprintf(stderr, " [%p %d]", (void *)conn, conn->inuse);
+      curr = curr->next;
+    }
+    fprintf(stderr, "\n");
+
+    he = Curl_hash_next_element(&iter);
+  }
+}
+#endif