/*
This file is part of GNUnet.
- (C) 2011 Christian Grothoff (and other contributing authors)
+ Copyright (C) 2011 GNUnet e.V.
GNUnet is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published
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.
+ Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ Boston, MA 02110-1301, USA.
*/
-
/**
* @file fs/gnunet-service-fs_lc.c
- * @brief API to handle 'connected peers'
+ * @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_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;
-
-};
-
-
-/**
- * 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;
-}
-
-
-/**
- * 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 pr handle to the original pending request
- * @param expiration when does 'data' expire?
- * @param data response data, NULL on request expiration
- * @param data_len number of bytes in data
- * @param more GNUNET_YES if the request remains active (may call
- * this function again), GNUNET_NO if the request is
- * finished (client must not call GSF_pending_request_cancel_)
- */
-static void
-client_response_handler (void *cls,
- struct GSF_PendingRequest *pr,
- struct GNUNET_TIME_Absolute expiration,
- const void *data,
- size_t data_len,
- int more)
-{
- struct ClientRequest *cr = cls;
- struct GSF_LocalClient *lc;
- struct PutMessage *pm;
- const struct GSF_PendingRequestData *prd;
- size_t msize;
-
- if (NULL == data)
- {
- /* ugh, request 'timed out' -- how can this be? */
- GNUNET_break (0);
- GNUNET_assert (GNUNET_NO == more);
- return;
- }
- GNUNET_STATISTICS_update (GSF_stats,
- gettext_noop ("# replies received for local clients"),
- 1,
- GNUNET_NO);
- prd = GSF_pending_request_get_data_ (pr);
- GNUNET_assert (pr == cr->pr);
- lc = cr->lc;
- msize = sizeof (struct PutMessage) + data_len;
- pm = GNUNET_malloc (msize);
- pm->header.type = htons (GNUNET_MESSAGE_TYPE_FS_PUT);
- pm->header.size = htons (msize);
- pm->type = htonl (prd->type);
- pm->expiration = GNUNET_TIME_absolute_hton (expiration);
- memcpy (&pm[1], data, data_len);
- GSF_local_client_transmit_ (lc, &pm->header);
-
- if (GNUNET_NO == more)
- {
- GNUNET_CONTAINER_DLL_remove (lc->cr_head,
- lc->cr_tail,
- cr);
- GNUNET_free (cr);
- }
-}
-
-
-/**
- * Handle START_SEARCH-message (search request from local client).
- *
- * @param client identification of the client
- * @param message the actual message
- * @return pending request handle for the request, NULL on error
- */
-struct GSF_PendingRequest *
-GSF_local_client_start_search_handler_ (struct GNUNET_SERVER_Client *client,
- const struct GNUNET_MessageHeader *message)
-{
- 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);
- GNUNET_SERVER_receive_done (client,
- GNUNET_SYSERR);
- return NULL;
- }
- 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);
-#if DEBUG_FS
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Received request for `%s' of type %u from local client\n",
- GNUNET_h2s (&sm->query),
- (unsigned int) type);
-#endif
- lc = GSF_local_client_lookup_ (client);
-
- /* detect duplicate KBLOCK requests */
- if ( (type == GNUNET_BLOCK_TYPE_FS_KBLOCK) ||
- (type == GNUNET_BLOCK_TYPE_FS_NBLOCK) ||
- (type == GNUNET_BLOCK_TYPE_ANY) )
- {
- /* FIXME: this does currently not work to filter duplicate
- results from *local* datastore since the local store is
- queried before we continue to process additional
- messages from the client! -- fix protocol? */
- cr = lc->cr_head;
- while (cr != NULL)
- {
- prd = GSF_pending_request_get_data_ (cr->pr);
- if ( (0 != memcmp (&prd->query,
- &sm->query,
- sizeof (GNUNET_HashCode))) &&
- (prd->type == type) )
- break;
- cr = cr->next;
- }
- if (cr != NULL)
- {
-#if DEBUG_FS
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Have existing request, merging content-seen lists.\n");
-#endif
- 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);
- GNUNET_SERVER_receive_done (client,
- GNUNET_OK);
- return NULL;
- }
- }
-
- 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 != (1 & 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 */,
- (const GNUNET_HashCode*) &sm[1], sc,
- &client_response_handler,
- cr);
- return cr->pr;
-}
-
-
-/**
- * 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_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 */
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