1 /** @addtogroup MCD_MCDIMPL_DAEMON_SRV
2  * @{
3  * @file
4  *
5  * Connection server.
6  *
7  * Handles incoming socket connections from clients using the MobiCore driver.
8  *
9  * Iterative socket server using Netlink dgram protocol.
10  *
11  * <!-- Copyright Giesecke & Devrient GmbH 2009 - 2012 -->
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  * 3. The name of the author may not be used to endorse or promote
22  *    products derived from this software without specific prior
23  *    written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
26  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
27  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
29  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
31  * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
33  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
34  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
35  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36  */
37 #ifndef NETLINKSERVER_H_
38 #define NETLINKSERVER_H_
39 
40 #include <sys/types.h>
41 #include <sys/socket.h>
42 #include <sys/un.h>
43 #include <linux/netlink.h>
44 #include <cstdio>
45 #include <map>
46 
47 #include "NetlinkConnection.h"
48 #include "ConnectionHandler.h"
49 #include "Server.h"
50 
51 class NetlinkServer: public Server, public NetlinkConnectionManager
52 {
53 public:
54     /**
55      * Server contructor.
56      *
57      * @param connectionHanler Connection handler to pass incoming connections to.
58      */
59     NetlinkServer(
60         ConnectionHandler *connectionHandler
61     );
62 
63     /**
64      * Server destructor.
65      * All available connections will be terminated. Resources will be freed.
66      */
67     virtual ~NetlinkServer(
68         void
69     );
70 
71     /**
72      * Start server and listen for incoming connections.
73      * Implements the central socket server loop. Incoming connections will be stored.
74      */
75     virtual void run(
76         void
77     );
78 
79     /**
80      * Remove a connection object from the list of available connections.
81      * Detaching is required for notification connections wich are never used to transfer command
82      * data from TLCs to the driver. If the function succeeds, freeing the connection will no longer
83      * be the server's responsability.
84      *
85      * @param connection The connection object to remove.
86      */
87     virtual void detachConnection(
88         Connection *connection
89     );
90 
91 private:
92     /**
93      * Handle incomming Netlink message.
94      * It routes the incomming packet to the apropriate connection based on the packet's
95      * session magic.
96      *
97      * @param nlh The netlink message's header + payload
98      */
99     void handleMessage(
100         struct nlmsghdr *nlh
101     );
102 
103     /**
104      * Retreive connection based on hash.
105      * Search the peer connections hashmap for a hash and return
106      * the associated Connection object
107      *
108      * @param seq The seq to search
109      * @return The NetlinkConnection object if found or NULL if not found
110      */
111     NetlinkConnection *findConnection(
112         uint64_t hash
113     );
114 
115     /**
116      * Insert a connection in the peer connection hashmap
117      * Insert a new connection in the peer connections hashmap. If there is
118      * already such a connection it will be overriden!
119      *
120      * @param seq The seq to use
121      * @param connection The connection object to insert
122      */
123     void insertConnection(
124         uint64_t hash,
125         NetlinkConnection *connection
126     );
127 
128     /**
129      * Remove a connection from the peer connections
130      * Remove the connection associated with seq from the peer list.
131      * This doesn't actually free the connection object!
132      * If the seq is invalid nothing happens.
133      *
134      * @param seq The seq to use
135      */
136     void removeConnection(
137         uint64_t hash
138     );
139 
140 
141     /**
142      * Check for sessions started by applications that died(exited)
143      * Remove the connections to applications that are not active anymore
144      * If the application has died then all the sessions associated with it
145      * should be closed!
146      *
147      */
148     void cleanupConnections(
149         void
150     );
151 
152     connectionMap_t peerConnections; /**< Hashmap with connections to clients */
153 };
154 
155 #endif /* SERVER_H_ */
156 
157 /** @} */
158