Imported Upstream version 0.9.2upstream/0.9.2

1 files changed, 510 insertions, 0 deletions

diff --git a/src/fs/gnunet-service-fs_lc.c b/src/fs/gnunet-service-fs_lc.c
new file mode 100644
index 0000000..36aafdd
--- /dev/null
+++ b/src/fs/gnunet-service-fs_lc.c
@@ -0,0 +1,510 @@
+/*
+     This file is part of GNUnet.
+     (C) 2011 Christian Grothoff (and other contributing authors)
+
+     GNUnet is free software; you can redistribute it and/or modify
+     it under the terms of the GNU General Public License as published
+     by the Free Software Foundation; either version 3, or (at your
+     option) any later version.
+
+     GNUnet is distributed in the hope that it will be useful, but
+     WITHOUT ANY WARRANTY; without even the implied warranty of
+     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+     General Public License for more details.
+
+     You should have received a copy of the GNU General Public License
+     along with GNUnet; see the file COPYING.  If not, write to the
+     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+     Boston, MA 02111-1307, USA.
+*/
+
+/**
+ * @file fs/gnunet-service-fs_lc.c
+ * @brief API to handle 'local clients'
+ * @author Christian Grothoff
+ */
+
+#include "platform.h"
+#include "gnunet-service-fs.h"
+#include "gnunet-service-fs_lc.h"
+#include "gnunet-service-fs_cp.h"
+#include "gnunet-service-fs_pr.h"
+
+
+/**
+ * Doubly-linked list of requests we are performing
+ * on behalf of the same client.
+ */
+struct ClientRequest
+{
+
+  /**
+   * This is a doubly-linked list.
+   */
+  struct ClientRequest *next;
+
+  /**
+   * This is a doubly-linked list.
+   */
+  struct ClientRequest *prev;
+
+  /**
+   * Request this entry represents.
+   */
+  struct GSF_PendingRequest *pr;
+
+  /**
+   * Client list this request belongs to.
+   */
+  struct GSF_LocalClient *lc;
+
+  /**
+   * Task scheduled to destroy the request.
+   */
+  GNUNET_SCHEDULER_TaskIdentifier kill_task;
+
+};
+
+
+/**
+ * Replies to be transmitted to the client.  The actual
+ * response message is allocated after this struct.
+ */
+struct ClientResponse
+{
+  /**
+   * This is a doubly-linked list.
+   */
+  struct ClientResponse *next;
+
+  /**
+   * This is a doubly-linked list.
+   */
+  struct ClientResponse *prev;
+
+  /**
+   * Client list entry this response belongs to.
+   */
+  struct GSF_LocalClient *lc;
+
+  /**
+   * Number of bytes in the response.
+   */
+  size_t msize;
+};
+
+
+/**
+ * A local client.
+ */
+struct GSF_LocalClient
+{
+
+  /**
+   * We keep clients in a DLL.
+   */
+  struct GSF_LocalClient *next;
+
+  /**
+   * We keep clients in a DLL.
+   */
+  struct GSF_LocalClient *prev;
+
+  /**
+   * ID of the client.
+   */
+  struct GNUNET_SERVER_Client *client;
+
+  /**
+   * Head of list of requests performed on behalf
+   * of this client right now.
+   */
+  struct ClientRequest *cr_head;
+
+  /**
+   * Tail of list of requests performed on behalf
+   * of this client right now.
+   */
+  struct ClientRequest *cr_tail;
+
+  /**
+   * Head of linked list of responses.
+   */
+  struct ClientResponse *res_head;
+
+  /**
+   * Tail of linked list of responses.
+   */
+  struct ClientResponse *res_tail;
+
+  /**
+   * Context for sending replies.
+   */
+  struct GNUNET_CONNECTION_TransmitHandle *th;
+
+};
+
+
+/**
+ * Head of linked list of our local clients.
+ */
+static struct GSF_LocalClient *client_head;
+
+
+/**
+ * Head of linked list of our local clients.
+ */
+static struct GSF_LocalClient *client_tail;
+
+
+/**
+ * Look up a local client record or create one if it
+ * doesn't exist yet.
+ *
+ * @param client handle of the client
+ * @return handle to local client entry
+ */
+struct GSF_LocalClient *
+GSF_local_client_lookup_ (struct GNUNET_SERVER_Client *client)
+{
+  struct GSF_LocalClient *pos;
+
+  pos = client_head;
+  while ((pos != NULL) && (pos->client != client))
+    pos = pos->next;
+  if (pos != NULL)
+    return pos;
+  pos = GNUNET_malloc (sizeof (struct GSF_LocalClient));
+  pos->client = client;
+  GNUNET_CONTAINER_DLL_insert (client_head, client_tail, pos);
+  return pos;
+}
+
+
+/**
+ * Free the given client request.
+ *
+ * @param cls the client request to free
+ * @param tc task context
+ */
+static void
+client_request_destroy (void *cls,
+                        const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+  struct ClientRequest *cr = cls;
+  struct GSF_LocalClient *lc;
+
+  cr->kill_task = GNUNET_SCHEDULER_NO_TASK;
+  lc = cr->lc;
+  GNUNET_CONTAINER_DLL_remove (lc->cr_head, lc->cr_tail, cr);
+  GSF_pending_request_cancel_ (cr->pr, GNUNET_NO);
+  GNUNET_STATISTICS_update (GSF_stats,
+                            gettext_noop ("# client searches active"), -1,
+                            GNUNET_NO);
+  GNUNET_free (cr);
+}
+
+
+/**
+ * Handle a reply to a pending request.  Also called if a request
+ * expires (then with data == NULL).  The handler may be called
+ * many times (depending on the request type), but will not be
+ * called during or after a call to GSF_pending_request_cancel
+ * and will also not be called anymore after a call signalling
+ * expiration.
+ *
+ * @param cls user-specified closure
+ * @param eval evaluation of the result
+ * @param pr handle to the original pending request
+ * @param reply_anonymity_level anonymity level for the reply, UINT32_MAX for "unknown"
+ * @param expiration when does 'data' expire?
+ * @param last_transmission when was the last time we've tried to download this block? (FOREVER if unknown)
+ * @param type type of the block
+ * @param data response data, NULL on request expiration
+ * @param data_len number of bytes in data
+ */
+static void
+client_response_handler (void *cls, enum GNUNET_BLOCK_EvaluationResult eval,
+                         struct GSF_PendingRequest *pr,
+                         uint32_t reply_anonymity_level,
+                         struct GNUNET_TIME_Absolute expiration,
+                         struct GNUNET_TIME_Absolute last_transmission,
+                         enum GNUNET_BLOCK_Type type, const void *data,
+                         size_t data_len)
+{
+  struct ClientRequest *cr = cls;
+  struct GSF_LocalClient *lc;
+  struct ClientPutMessage *pm;
+  const struct GSF_PendingRequestData *prd;
+  size_t msize;
+
+  if (NULL == data)
+  {
+    /* ugh, request 'timed out' -- how can this be? */
+    GNUNET_break (0);
+    return;
+  }
+  prd = GSF_pending_request_get_data_ (pr);
+  GNUNET_break (type != GNUNET_BLOCK_TYPE_ANY);
+  if ((prd->type != type) && (prd->type != GNUNET_BLOCK_TYPE_ANY))
+  {
+    GNUNET_break (0);
+    return;
+  }
+  GNUNET_STATISTICS_update (GSF_stats,
+                            gettext_noop
+                            ("# replies received for local clients"), 1,
+                            GNUNET_NO);
+  GNUNET_assert (pr == cr->pr);
+  lc = cr->lc;
+  msize = sizeof (struct ClientPutMessage) + data_len;
+  {
+    char buf[msize];
+
+    pm = (struct ClientPutMessage *) buf;
+    pm->header.type = htons (GNUNET_MESSAGE_TYPE_FS_PUT);
+    pm->header.size = htons (msize);
+    pm->type = htonl (type);
+    pm->expiration = GNUNET_TIME_absolute_hton (expiration);
+    pm->last_transmission = GNUNET_TIME_absolute_hton (last_transmission);
+    memcpy (&pm[1], data, data_len);
+    GSF_local_client_transmit_ (lc, &pm->header);
+  }
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Queued reply to query `%s' for local client\n",
+              GNUNET_h2s (&prd->query), (unsigned int) prd->type);
+  if (eval != GNUNET_BLOCK_EVALUATION_OK_LAST)
+    return;
+  if (GNUNET_SCHEDULER_NO_TASK != cr->kill_task)
+    cr->kill_task = GNUNET_SCHEDULER_add_now (&client_request_destroy, cr);
+}
+
+
+/**
+ * Handle START_SEARCH-message (search request from local client).
+ * Only responsible for creating the request entry itself and setting
+ * up reply callback and cancellation on client disconnect.  Does NOT
+ * execute the actual request strategy (planning).
+ *
+ * @param client identification of the client
+ * @param message the actual message
+ * @param prptr where to store the pending request handle for the request
+ * @return GNUNET_YES to start local processing,
+ *         GNUNET_NO to not (yet) start local processing,
+ *         GNUNET_SYSERR on error
+ */
+int
+GSF_local_client_start_search_handler_ (struct GNUNET_SERVER_Client *client,
+                                        const struct GNUNET_MessageHeader
+                                        *message,
+                                        struct GSF_PendingRequest **prptr)
+{
+  static GNUNET_HashCode all_zeros;
+  const struct SearchMessage *sm;
+  struct GSF_LocalClient *lc;
+  struct ClientRequest *cr;
+  struct GSF_PendingRequestData *prd;
+  uint16_t msize;
+  unsigned int sc;
+  enum GNUNET_BLOCK_Type type;
+  enum GSF_PendingRequestOptions options;
+
+  msize = ntohs (message->size);
+  if ((msize < sizeof (struct SearchMessage)) ||
+      (0 != (msize - sizeof (struct SearchMessage)) % sizeof (GNUNET_HashCode)))
+  {
+    GNUNET_break (0);
+    *prptr = NULL;
+    return GNUNET_SYSERR;
+  }
+  GNUNET_STATISTICS_update (GSF_stats,
+                            gettext_noop ("# client searches received"), 1,
+                            GNUNET_NO);
+  sc = (msize - sizeof (struct SearchMessage)) / sizeof (GNUNET_HashCode);
+  sm = (const struct SearchMessage *) message;
+  type = ntohl (sm->type);
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Received request for `%s' of type %u from local client\n",
+              GNUNET_h2s (&sm->query), (unsigned int) type);
+  lc = GSF_local_client_lookup_ (client);
+  cr = NULL;
+  /* detect duplicate KBLOCK requests */
+  if ((type == GNUNET_BLOCK_TYPE_FS_KBLOCK) ||
+      (type == GNUNET_BLOCK_TYPE_FS_NBLOCK) || (type == GNUNET_BLOCK_TYPE_ANY))
+  {
+    cr = lc->cr_head;
+    while (cr != NULL)
+    {
+      prd = GSF_pending_request_get_data_ (cr->pr);
+      /* only unify with queries that hae not yet started local processing
+	 (SEARCH_MESSAGE_OPTION_CONTINUED was always set) and that have a
+	 matching query and type */
+      if ((GNUNET_YES != prd->has_started) &&
+	  (0 != memcmp (&prd->query, &sm->query, sizeof (GNUNET_HashCode))) &&
+          (prd->type == type))
+        break;
+      cr = cr->next;
+    }
+  }
+  if (cr != NULL)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                "Have existing request, merging content-seen lists.\n");
+    GSF_pending_request_update_ (cr->pr, (const GNUNET_HashCode *) &sm[1], sc);
+    GNUNET_STATISTICS_update (GSF_stats,
+                              gettext_noop
+                              ("# client searches updated (merged content seen list)"),
+                              1, GNUNET_NO);
+  }
+  else
+  {
+    GNUNET_STATISTICS_update (GSF_stats,
+                              gettext_noop ("# client searches active"), 1,
+                              GNUNET_NO);
+    cr = GNUNET_malloc (sizeof (struct ClientRequest));
+    cr->lc = lc;
+    GNUNET_CONTAINER_DLL_insert (lc->cr_head, lc->cr_tail, cr);
+    options = GSF_PRO_LOCAL_REQUEST;
+    if (0 != (SEARCH_MESSAGE_OPTION_LOOPBACK_ONLY & ntohl (sm->options)))
+      options |= GSF_PRO_LOCAL_ONLY;
+    cr->pr = GSF_pending_request_create_ (options, type, &sm->query, (type == GNUNET_BLOCK_TYPE_FS_SBLOCK) ? &sm->target        /* namespace */
+                                          : NULL,
+                                          (0 !=
+                                           memcmp (&sm->target, &all_zeros,
+                                                   sizeof (GNUNET_HashCode)))
+                                          ? (const struct GNUNET_PeerIdentity *)
+                                          &sm->target : NULL, NULL, 0,
+                                          0 /* bf */ ,
+                                          ntohl (sm->anonymity_level),
+                                          0 /* priority */ ,
+                                          0 /* ttl */ ,
+                                          0 /* sender PID */ ,
+                                          0 /* origin PID */ ,
+                                          (const GNUNET_HashCode *) &sm[1], sc,
+                                          &client_response_handler, cr);
+  }
+  *prptr = cr->pr;
+  return (0 !=
+          (SEARCH_MESSAGE_OPTION_CONTINUED & ntohl (sm->options))) ? GNUNET_NO :
+      GNUNET_YES;
+}
+
+
+/**
+ * Transmit the given message by copying it to the target buffer
+ * "buf".  "buf" will be NULL and "size" zero if the socket was closed
+ * for writing in the meantime.  In that case, do nothing
+ * (the disconnect or shutdown handler will take care of the rest).
+ * If we were able to transmit messages and there are still more
+ * pending, ask core again for further calls to this function.
+ *
+ * @param cls closure, pointer to the 'struct GSF_LocalClient'
+ * @param size number of bytes available in buf
+ * @param buf where the callee should write the message
+ * @return number of bytes written to buf
+ */
+static size_t
+transmit_to_client (void *cls, size_t size, void *buf)
+{
+  struct GSF_LocalClient *lc = cls;
+  char *cbuf = buf;
+  struct ClientResponse *res;
+  size_t msize;
+
+  lc->th = NULL;
+  if (NULL == buf)
+    return 0;
+  msize = 0;
+  while ((NULL != (res = lc->res_head)) && (res->msize <= size))
+  {
+    memcpy (&cbuf[msize], &res[1], res->msize);
+    msize += res->msize;
+    size -= res->msize;
+    GNUNET_CONTAINER_DLL_remove (lc->res_head, lc->res_tail, res);
+    GNUNET_free (res);
+  }
+  if (NULL != res)
+    lc->th =
+        GNUNET_SERVER_notify_transmit_ready (lc->client, res->msize,
+                                             GNUNET_TIME_UNIT_FOREVER_REL,
+                                             &transmit_to_client, lc);
+  return msize;
+}
+
+
+/**
+ * Transmit a message to the given local client as soon as possible.
+ * If the client disconnects before transmission, the message is
+ * simply discarded.
+ *
+ * @param lc recipient
+ * @param msg message to transmit to client
+ */
+void
+GSF_local_client_transmit_ (struct GSF_LocalClient *lc,
+                            const struct GNUNET_MessageHeader *msg)
+{
+  struct ClientResponse *res;
+  size_t msize;
+
+  msize = ntohs (msg->size);
+  res = GNUNET_malloc (sizeof (struct ClientResponse) + msize);
+  res->lc = lc;
+  res->msize = msize;
+  memcpy (&res[1], msg, msize);
+  GNUNET_CONTAINER_DLL_insert_tail (lc->res_head, lc->res_tail, res);
+  if (NULL == lc->th)
+    lc->th =
+        GNUNET_SERVER_notify_transmit_ready (lc->client, msize,
+                                             GNUNET_TIME_UNIT_FOREVER_REL,
+                                             &transmit_to_client, lc);
+}
+
+
+/**
+ * A client disconnected from us.  Tear down the local client
+ * record.
+ *
+ * @param cls unused
+ * @param client handle of the client
+ */
+void
+GSF_client_disconnect_handler_ (void *cls, struct GNUNET_SERVER_Client *client)
+{
+  struct GSF_LocalClient *pos;
+  struct ClientRequest *cr;
+  struct ClientResponse *res;
+
+  pos = client_head;
+  while ((pos != NULL) && (pos->client != client))
+    pos = pos->next;
+  if (pos == NULL)
+    return;
+  while (NULL != (cr = pos->cr_head))
+  {
+    GNUNET_CONTAINER_DLL_remove (pos->cr_head, pos->cr_tail, cr);
+    GSF_pending_request_cancel_ (cr->pr, GNUNET_NO);
+    GNUNET_STATISTICS_update (GSF_stats,
+                              gettext_noop ("# client searches active"), -1,
+                              GNUNET_NO);
+    if (GNUNET_SCHEDULER_NO_TASK != cr->kill_task)
+      GNUNET_SCHEDULER_cancel (cr->kill_task);
+    GNUNET_free (cr);
+  }
+  while (NULL != (res = pos->res_head))
+  {
+    GNUNET_CONTAINER_DLL_remove (pos->res_head, pos->res_tail, res);
+    GNUNET_free (res);
+  }
+  if (pos->th != NULL)
+  {
+    GNUNET_CONNECTION_notify_transmit_ready_cancel (pos->th);
+    pos->th = NULL;
+  }
+  GSF_handle_local_client_disconnect_ (pos);
+  GNUNET_CONTAINER_DLL_remove (client_head, client_tail, pos);
+  GNUNET_free (pos);
+}
+
+
+/* end of gnunet-service-fs_lc.c */