2 This file is part of GNUnet.
3 (C) 2009, 2010 Christian Grothoff (and other contributing authors)
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6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
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11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
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17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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22 * @file dht/dht_api_find_peer.c
23 * @brief library to access the DHT to find peers
24 * @author Christian Grothoff
25 * @author Nathan Evans
29 #include "gnunet_constants.h"
30 #include "gnunet_arm_service.h"
31 #include "gnunet_protocols.h"
32 #include "gnunet_util_lib.h"
33 #include "gnunet_dht_service.h"
38 * Handle to control a find peer operation.
40 struct GNUNET_DHT_FindPeerHandle
44 * Handle to the actual route operation for the request
46 struct GNUNET_DHT_RouteHandle *route_handle;
49 * Iterator to call on data receipt
51 GNUNET_DHT_FindPeerProcessor proc;
54 * Closure for the iterator callback
63 * Iterator called on each result obtained from a generic route
67 * @param key key that was used
68 * @param outgoing_path NULL-terminated array of pointers
69 * to the peers on reverse path
70 * (or NULL if not recorded)
71 * @param reply response
74 find_peer_reply_iterator (void *cls,
75 const GNUNET_HashCode * key,
76 const struct GNUNET_PeerIdentity *const
78 const struct GNUNET_MessageHeader *reply)
80 struct GNUNET_DHT_FindPeerHandle *find_peer_handle = cls;
81 const struct GNUNET_MessageHeader *hello;
83 if (ntohs (reply->type) != GNUNET_MESSAGE_TYPE_DHT_FIND_PEER_RESULT)
88 GNUNET_assert (ntohs (reply->size) >= sizeof (struct GNUNET_MessageHeader));
89 hello = (const struct GNUNET_MessageHeader *) &reply[1];
90 if (ntohs (hello->type) != GNUNET_MESSAGE_TYPE_HELLO)
95 find_peer_handle->proc (find_peer_handle->proc_cls,
96 (const struct GNUNET_HELLO_Message *) hello);
102 * Perform an asynchronous FIND PEER operation on the DHT.
104 * @param handle handle to the DHT service
105 * @param timeout timeout for this request to be sent to the
107 * @param options routing options for this message
108 * @param key the key to look up
109 * @param proc function to call on each result
110 * @param proc_cls closure for proc
111 * @return handle to stop the async get, NULL on error
113 struct GNUNET_DHT_FindPeerHandle *
114 GNUNET_DHT_find_peer_start (struct GNUNET_DHT_Handle *handle,
115 struct GNUNET_TIME_Relative timeout,
116 const GNUNET_HashCode * key,
117 enum GNUNET_DHT_RouteOption options,
118 GNUNET_DHT_FindPeerProcessor proc, void *proc_cls)
120 struct GNUNET_DHT_FindPeerHandle *find_peer_handle;
121 struct GNUNET_DHT_FindPeerMessage find_peer_msg;
123 find_peer_handle = GNUNET_malloc (sizeof (struct GNUNET_DHT_FindPeerHandle));
124 find_peer_handle->proc = proc;
125 find_peer_handle->proc_cls = proc_cls;
126 find_peer_msg.header.size =
127 htons (sizeof (struct GNUNET_DHT_FindPeerMessage));
128 find_peer_msg.header.type = htons (GNUNET_MESSAGE_TYPE_DHT_FIND_PEER);
129 find_peer_handle->route_handle =
130 GNUNET_DHT_route_start (handle, key,
132 &find_peer_msg.header,
134 &find_peer_reply_iterator, find_peer_handle,
136 GNUNET_break (find_peer_handle->route_handle != NULL);
137 return find_peer_handle;
142 * Stop async find peer. Frees associated resources.
144 * @param find_peer_handle GET operation to stop.
147 GNUNET_DHT_find_peer_stop (struct GNUNET_DHT_FindPeerHandle *find_peer_handle)
149 GNUNET_DHT_route_stop (find_peer_handle->route_handle);
150 GNUNET_free (find_peer_handle);
154 /* end of dht_api_find_peer.c */