make all (?) asynchronously operating FS operations actually cancel-able

1 files changed, 342 insertions, 0 deletions

diff --git a/src/fs/fs_publish_ksk.c b/src/fs/fs_publish_ksk.c
new file mode 100644
index 000000000..5119de4c5
--- /dev/null
+++ b/src/fs/fs_publish_ksk.c
@@ -0,0 +1,342 @@
+/*
+     This file is part of GNUnet.
+     (C) 2009, 2010, 2012 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/fs_publish_ksk.c
+ * @brief publish a URI under a keyword in GNUnet
+ * @see https://gnunet.org/encoding
+ * @author Krista Bennett
+ * @author Christian Grothoff
+ */
+
+#include "platform.h"
+#include "gnunet_constants.h"
+#include "gnunet_signatures.h"
+#include "gnunet_util_lib.h"
+#include "gnunet_fs_service.h"
+#include "fs_api.h"
+#include "fs_tree.h"
+
+
+/**
+ * Maximum legal size for a kblock.
+ */
+#define MAX_KBLOCK_SIZE (60 * 1024)
+
+
+/**
+ * Context for the KSK publication.
+ */
+struct GNUNET_FS_PublishKskContext
+{
+
+  /**
+   * Keywords to use.
+   */
+  struct GNUNET_FS_Uri *ksk_uri;
+
+  /**
+   * Global FS context.
+   */
+  struct GNUNET_FS_Handle *h;
+
+  /**
+   * The master block that we are sending
+   * (in plaintext), has "mdsize+slen" more
+   * bytes than the struct would suggest.
+   */
+  struct KBlock *kb;
+
+  /**
+   * Buffer of the same size as "kb" for
+   * the encrypted version.
+   */
+  struct KBlock *cpy;
+
+  /**
+   * Handle to the datastore, NULL if we are just
+   * simulating.
+   */
+  struct GNUNET_DATASTORE_Handle *dsh;
+
+  /**
+   * Handle to datastore PUT request.
+   */
+  struct GNUNET_DATASTORE_QueueEntry *qre;
+
+  /**
+   * Current task.
+   */
+  GNUNET_SCHEDULER_TaskIdentifier ksk_task;
+
+  /**
+   * Function to call once we're done.
+   */
+  GNUNET_FS_PublishContinuation cont;
+
+  /**
+   * Closure for cont.
+   */
+  void *cont_cls;
+
+  /**
+   * When should the KBlocks expire?
+   */
+  struct GNUNET_FS_BlockOptions bo;
+
+  /**
+   * Size of the serialized metadata.
+   */
+  ssize_t mdsize;
+
+  /**
+   * Size of the (CHK) URI as a string.
+   */
+  size_t slen;
+
+  /**
+   * Keyword that we are currently processing.
+   */
+  unsigned int i;
+
+};
+
+
+/**
+ * Continuation of "GNUNET_FS_publish_ksk" that performs
+ * the actual publishing operation (iterating over all
+ * of the keywords).
+ *
+ * @param cls closure of type "struct PublishKskContext*"
+ * @param tc unused
+ */
+static void
+publish_ksk_cont (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
+
+
+/**
+ * Function called by the datastore API with
+ * the result from the PUT request.
+ *
+ * @param cls closure of type "struct GNUNET_FS_PublishKskContext*"
+ * @param success GNUNET_OK on success
+ * @param min_expiration minimum expiration time required for content to be stored
+ * @param msg error message (or NULL)
+ */
+static void
+kb_put_cont (void *cls, int success, 
+             struct GNUNET_TIME_Absolute min_expiration,
+             const char *msg)
+{
+  struct GNUNET_FS_PublishKskContext *pkc = cls;
+
+  pkc->qre = NULL;
+  if (GNUNET_OK != success)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, 
+                "KBlock PUT operation failed: %s\n", msg);
+    pkc->cont (pkc->cont_cls, NULL, msg);
+    GNUNET_FS_publish_ksk_cancel (pkc);
+    return;
+  }
+  pkc->ksk_task = GNUNET_SCHEDULER_add_now (&publish_ksk_cont, pkc);
+}
+
+
+/**
+ * Continuation of "GNUNET_FS_publish_ksk" that performs the actual
+ * publishing operation (iterating over all of the keywords).
+ *
+ * @param cls closure of type "struct GNUNET_FS_PublishKskContext*"
+ * @param tc unused
+ */
+static void
+publish_ksk_cont (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+  struct GNUNET_FS_PublishKskContext *pkc = cls;
+  const char *keyword;
+  GNUNET_HashCode key;
+  GNUNET_HashCode query;
+  struct GNUNET_CRYPTO_AesSessionKey skey;
+  struct GNUNET_CRYPTO_AesInitializationVector iv;
+  struct GNUNET_CRYPTO_RsaPrivateKey *pk;
+
+  pkc->ksk_task = GNUNET_SCHEDULER_NO_TASK;
+  if ((pkc->i == pkc->ksk_uri->data.ksk.keywordCount) || (NULL == pkc->dsh))
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "KSK PUT operation complete\n");
+    pkc->cont (pkc->cont_cls, pkc->ksk_uri, NULL);
+    GNUNET_FS_publish_ksk_cancel (pkc);
+    return;
+  }
+  keyword = pkc->ksk_uri->data.ksk.keywords[pkc->i++];
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Publishing under keyword `%s'\n",
+              keyword);
+  /* first character of keyword indicates if it is
+   * mandatory or not -- ignore for hashing */
+  GNUNET_CRYPTO_hash (&keyword[1], strlen (&keyword[1]), &key);
+  GNUNET_CRYPTO_hash_to_aes_key (&key, &skey, &iv);
+  GNUNET_CRYPTO_aes_encrypt (&pkc->kb[1], pkc->slen + pkc->mdsize, &skey, &iv,
+                             &pkc->cpy[1]);
+  pk = GNUNET_CRYPTO_rsa_key_create_from_hash (&key);
+  GNUNET_assert (NULL != pk);
+  GNUNET_CRYPTO_rsa_key_get_public (pk, &pkc->cpy->keyspace);
+  GNUNET_CRYPTO_hash (&pkc->cpy->keyspace,
+                      sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
+                      &query);
+  GNUNET_assert (GNUNET_OK ==
+                 GNUNET_CRYPTO_rsa_sign (pk, &pkc->cpy->purpose,
+                                         &pkc->cpy->signature));
+  GNUNET_CRYPTO_rsa_key_free (pk);
+  pkc->qre =
+      GNUNET_DATASTORE_put (pkc->dsh, 0, &query,
+                            pkc->mdsize + sizeof (struct KBlock) + pkc->slen,
+                            pkc->cpy, GNUNET_BLOCK_TYPE_FS_KBLOCK,
+                            pkc->bo.content_priority, pkc->bo.anonymity_level,
+                            pkc->bo.replication_level, pkc->bo.expiration_time,
+                            -2, 1, GNUNET_CONSTANTS_SERVICE_TIMEOUT,
+                            &kb_put_cont, pkc);
+}
+
+
+/**
+ * Publish a CHK under various keywords on GNUnet.
+ *
+ * @param h handle to the file sharing subsystem
+ * @param ksk_uri keywords to use
+ * @param meta metadata to use
+ * @param uri URI to refer to in the KBlock
+ * @param bo per-block options
+ * @param options publication options
+ * @param cont continuation
+ * @param cont_cls closure for cont
+ * @return NULL on error ('cont' will still be called)
+ */
+struct GNUNET_FS_PublishKskContext *
+GNUNET_FS_publish_ksk (struct GNUNET_FS_Handle *h,
+                       const struct GNUNET_FS_Uri *ksk_uri,
+                       const struct GNUNET_CONTAINER_MetaData *meta,
+                       const struct GNUNET_FS_Uri *uri,
+                       const struct GNUNET_FS_BlockOptions *bo,
+                       enum GNUNET_FS_PublishOptions options,
+                       GNUNET_FS_PublishContinuation cont, void *cont_cls)
+{
+  struct GNUNET_FS_PublishKskContext *pkc;
+  char *uris;
+  size_t size;
+  char *kbe;
+  char *sptr;
+
+  GNUNET_assert (NULL != uri);
+  pkc = GNUNET_malloc (sizeof (struct GNUNET_FS_PublishKskContext));
+  pkc->h = h;
+  pkc->bo = *bo;
+  pkc->cont = cont;
+  pkc->cont_cls = cont_cls;
+  if (0 == (options & GNUNET_FS_PUBLISH_OPTION_SIMULATE_ONLY))
+  {
+    pkc->dsh = GNUNET_DATASTORE_connect (h->cfg);
+    if (NULL == pkc->dsh)
+    {
+      cont (cont_cls, NULL, _("Could not connect to datastore."));
+      GNUNET_free (pkc);
+      return NULL;
+    }
+  }
+  if (meta == NULL)
+    pkc->mdsize = 0;
+  else
+    pkc->mdsize = GNUNET_CONTAINER_meta_data_get_serialized_size (meta);
+  GNUNET_assert (pkc->mdsize >= 0);
+  uris = GNUNET_FS_uri_to_string (uri);
+  pkc->slen = strlen (uris) + 1;
+  size = pkc->mdsize + sizeof (struct KBlock) + pkc->slen;
+  if (size > MAX_KBLOCK_SIZE)
+  {
+    size = MAX_KBLOCK_SIZE;
+    pkc->mdsize = size - sizeof (struct KBlock) - pkc->slen;
+  }
+  pkc->kb = GNUNET_malloc (size);
+  kbe = (char *) &pkc->kb[1];
+  memcpy (kbe, uris, pkc->slen);
+  GNUNET_free (uris);
+  sptr = &kbe[pkc->slen];
+  if (meta != NULL)
+    pkc->mdsize =
+        GNUNET_CONTAINER_meta_data_serialize (meta, &sptr, pkc->mdsize,
+                                              GNUNET_CONTAINER_META_DATA_SERIALIZE_PART);
+  if (-1 == pkc->mdsize)
+  {
+    GNUNET_break (0);
+    GNUNET_free (pkc->kb);
+    if (pkc->dsh != NULL)
+    {
+      GNUNET_DATASTORE_disconnect (pkc->dsh, GNUNET_NO);
+      pkc->dsh = NULL;
+    }
+    GNUNET_free (pkc);
+    cont (cont_cls, NULL, _("Internal error."));
+    return NULL;
+  }
+  size = sizeof (struct KBlock) + pkc->slen + pkc->mdsize;
+
+  pkc->cpy = GNUNET_malloc (size);
+  pkc->cpy->purpose.size =
+      htonl (sizeof (struct GNUNET_CRYPTO_RsaSignaturePurpose) +
+             sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded) +
+             pkc->mdsize + pkc->slen);
+  pkc->cpy->purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_FS_KBLOCK);
+  pkc->ksk_uri = GNUNET_FS_uri_dup (ksk_uri);
+  pkc->ksk_task = GNUNET_SCHEDULER_add_now (&publish_ksk_cont, pkc);
+  return pkc;
+}
+
+
+/**
+ * Abort the KSK publishing operation.
+ *
+ * @param pkc context of the operation to abort.
+ */
+void
+GNUNET_FS_publish_ksk_cancel (struct GNUNET_FS_PublishKskContext *pkc)
+{
+  if (GNUNET_SCHEDULER_NO_TASK != pkc->ksk_task)
+  {
+    GNUNET_SCHEDULER_cancel (pkc->ksk_task);
+    pkc->ksk_task = GNUNET_SCHEDULER_NO_TASK;
+  }
+  if (NULL != pkc->qre)
+  {
+    GNUNET_DATASTORE_cancel (pkc->qre);
+    pkc->qre = NULL;
+  }
+  if (NULL != pkc->dsh)
+  {
+    GNUNET_DATASTORE_disconnect (pkc->dsh, GNUNET_NO);
+    pkc->dsh = NULL;
+  }
+  GNUNET_free (pkc->cpy);
+  GNUNET_free (pkc->kb);
+  GNUNET_FS_uri_destroy (pkc->ksk_uri);
+  GNUNET_free (pkc);
+}
+
+
+/* end of fs_publish_ksk.c */