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<h1>Socket</h1> </div>
<div class="ingroups"><a class="el" href="group__nl.html">Core Netlink API</a></div></div>
<div class="contents">
<p>Handle representing a netlink socket.
<a href="#_details">More...</a></p>
<table class="memberdecls">
<tr><td colspan="2"><h2><a name="member-group"></a>
Allocation</h2></td></tr>
<tr><td class="memItemLeft" align="right" valign="top">struct nl_handle * </td><td class="memItemRight" valign="bottom"><a class="el" href="group__socket.html#gaf903c9ea089735b1ba8e40dae801c47d">nl_handle_alloc</a> (void)</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Allocate new netlink socket handle. <a href="#gaf903c9ea089735b1ba8e40dae801c47d"></a><br/></td></tr>
<tr><td class="memItemLeft" align="right" valign="top">struct nl_handle * </td><td class="memItemRight" valign="bottom"><a class="el" href="group__socket.html#gaeae22da82a96561d9b89fb67763c258d">nl_handle_alloc_cb</a> (struct nl_cb *cb)</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Allocate new socket handle with custom callbacks. <a href="#gaeae22da82a96561d9b89fb67763c258d"></a><br/></td></tr>
<tr><td class="memItemLeft" align="right" valign="top">void </td><td class="memItemRight" valign="bottom"><a class="el" href="group__socket.html#gaf73c4d1d895ec4cd19f504aae96219b5">nl_handle_destroy</a> (struct nl_handle *handle)</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Destroy netlink handle. <a href="#gaf73c4d1d895ec4cd19f504aae96219b5"></a><br/></td></tr>
<tr><td colspan="2"><h2><a name="member-group"></a>
Sequence Numbers</h2></td></tr>
<tr><td class="memItemLeft" align="right" valign="top">void </td><td class="memItemRight" valign="bottom"><a class="el" href="group__socket.html#ga0ff2f43147e3a4547f7109578b3ca422">nl_disable_sequence_check</a> (struct nl_handle *handle)</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Disable sequence number checking. <a href="#ga0ff2f43147e3a4547f7109578b3ca422"></a><br/></td></tr>
<tr><td class="memItemLeft" align="right" valign="top">unsigned int </td><td class="memItemRight" valign="bottom"><a class="el" href="group__socket.html#ga92142abf81ef25b2518528dc9f82ce98">nl_socket_use_seq</a> (struct nl_handle *handle)</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Use next sequence number. <a href="#ga92142abf81ef25b2518528dc9f82ce98"></a><br/></td></tr>
<tr><td colspan="2"><h2><a name="member-group"></a>
Source Idenficiation</h2></td></tr>
<tr><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="gabd4ed5b431c7ed3bf41cfa49d53e3663"></a><!-- doxytag: member="socket::nl_socket_get_local_port" ref="gabd4ed5b431c7ed3bf41cfa49d53e3663" args="(struct nl_handle *handle)" -->
uint32_t </td><td class="memItemRight" valign="bottom"><b>nl_socket_get_local_port</b> (struct nl_handle *handle)</td></tr>
<tr><td class="memItemLeft" align="right" valign="top">void </td><td class="memItemRight" valign="bottom"><a class="el" href="group__socket.html#ga9cf7b89ddc00d1c9d7c0f00437c27e6b">nl_socket_set_local_port</a> (struct nl_handle *handle, uint32_t port)</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Set local port of socket. <a href="#ga9cf7b89ddc00d1c9d7c0f00437c27e6b"></a><br/></td></tr>
<tr><td colspan="2"><h2><a name="member-group"></a>
Group Subscriptions</h2></td></tr>
<tr><td class="memItemLeft" align="right" valign="top">int </td><td class="memItemRight" valign="bottom"><a class="el" href="group__socket.html#ga3d0fb09feebd7fe9d919437aef47239a">nl_socket_add_membership</a> (struct nl_handle *handle, int group)</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Join a group. <a href="#ga3d0fb09feebd7fe9d919437aef47239a"></a><br/></td></tr>
<tr><td class="memItemLeft" align="right" valign="top">int </td><td class="memItemRight" valign="bottom"><a class="el" href="group__socket.html#ga0114b0736393662d10296a0480ebd49d">nl_socket_drop_membership</a> (struct nl_handle *handle, int group)</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Leave a group. <a href="#ga0114b0736393662d10296a0480ebd49d"></a><br/></td></tr>
<tr><td class="memItemLeft" align="right" valign="top">void </td><td class="memItemRight" valign="bottom"><a class="el" href="group__socket.html#gab6a2c1fb173efe3696184bdb2c5f5ae7">nl_join_groups</a> (struct nl_handle *handle, int groups)</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Join multicast groups (deprecated) <a href="#gab6a2c1fb173efe3696184bdb2c5f5ae7"></a><br/></td></tr>
<tr><td colspan="2"><h2><a name="member-group"></a>
Peer Identfication</h2></td></tr>
<tr><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="gade89ef9bc39b3ac548e72dd7fd46822c"></a><!-- doxytag: member="socket::nl_socket_get_peer_port" ref="gade89ef9bc39b3ac548e72dd7fd46822c" args="(struct nl_handle *handle)" -->
uint32_t </td><td class="memItemRight" valign="bottom"><b>nl_socket_get_peer_port</b> (struct nl_handle *handle)</td></tr>
<tr><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="ga6e5776649504df187653113a7d2eee7a"></a><!-- doxytag: member="socket::nl_socket_set_peer_port" ref="ga6e5776649504df187653113a7d2eee7a" args="(struct nl_handle *handle, uint32_t port)" -->
void </td><td class="memItemRight" valign="bottom"><b>nl_socket_set_peer_port</b> (struct nl_handle *handle, uint32_t port)</td></tr>
<tr><td colspan="2"><h2><a name="member-group"></a>
File Descriptor</h2></td></tr>
<tr><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="ga05497fee30b0ea23b6c60a214c4e0059"></a><!-- doxytag: member="socket::nl_socket_get_fd" ref="ga05497fee30b0ea23b6c60a214c4e0059" args="(struct nl_handle *handle)" -->
int </td><td class="memItemRight" valign="bottom"><b>nl_socket_get_fd</b> (struct nl_handle *handle)</td></tr>
<tr><td class="memItemLeft" align="right" valign="top">int </td><td class="memItemRight" valign="bottom"><a class="el" href="group__socket.html#gafbf20258be9d18116a9179c76cdd2637">nl_socket_set_nonblocking</a> (struct nl_handle *handle)</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Set file descriptor of socket handle to non-blocking state. <a href="#gafbf20258be9d18116a9179c76cdd2637"></a><br/></td></tr>
<tr><td class="memItemLeft" align="right" valign="top">void </td><td class="memItemRight" valign="bottom"><a class="el" href="group__socket.html#ga6dcc8125ee5726e240d8c04b2b83df2f">nl_socket_enable_msg_peek</a> (struct nl_handle *handle)</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Enable use of MSG_PEEK when reading from socket. <a href="#ga6dcc8125ee5726e240d8c04b2b83df2f"></a><br/></td></tr>
<tr><td class="memItemLeft" align="right" valign="top">void </td><td class="memItemRight" valign="bottom"><a class="el" href="group__socket.html#gaa385f5778249903909a0016f89044faa">nl_socket_disable_msg_peek</a> (struct nl_handle *handle)</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Disable use of MSG_PEEK when reading from socket. <a href="#gaa385f5778249903909a0016f89044faa"></a><br/></td></tr>
<tr><td colspan="2"><h2><a name="member-group"></a>
Callback Handler</h2></td></tr>
<tr><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="gacfa811f4c8200ac214b064ef6a661ae6"></a><!-- doxytag: member="socket::nl_socket_get_cb" ref="gacfa811f4c8200ac214b064ef6a661ae6" args="(struct nl_handle *handle)" -->
struct nl_cb * </td><td class="memItemRight" valign="bottom"><b>nl_socket_get_cb</b> (struct nl_handle *handle)</td></tr>
<tr><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="gaee5a6852433a1817ef9973530eecb68e"></a><!-- doxytag: member="socket::nl_socket_set_cb" ref="gaee5a6852433a1817ef9973530eecb68e" args="(struct nl_handle *handle, struct nl_cb *cb)" -->
void </td><td class="memItemRight" valign="bottom"><b>nl_socket_set_cb</b> (struct nl_handle *handle, struct nl_cb *cb)</td></tr>
<tr><td class="memItemLeft" align="right" valign="top">int </td><td class="memItemRight" valign="bottom"><a class="el" href="group__socket.html#ga6ae4e46ad6ea991e92dd0cc2653ff371">nl_socket_modify_cb</a> (struct nl_handle *handle, enum <a class="el" href="group__cb.html#ga3f60f4515ada826d2bf16395ee722363">nl_cb_type</a> type, enum <a class="el" href="group__cb.html#gaba3fabad0c62db483941101e1a18d14d">nl_cb_kind</a> kind, <a class="el" href="group__cb.html#ga1bf04ce17ab1b5867017556a6b4ba729">nl_recvmsg_msg_cb_t</a> func, void *arg)</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Modify the callback handler associated to the socket. <a href="#ga6ae4e46ad6ea991e92dd0cc2653ff371"></a><br/></td></tr>
<tr><td colspan="2"><h2><a name="member-group"></a>
Utilities</h2></td></tr>
<tr><td class="memItemLeft" align="right" valign="top">int </td><td class="memItemRight" valign="bottom"><a class="el" href="group__socket.html#ga0b6d4741ee2ec8f0392b600a626ff1fd">nl_set_buffer_size</a> (struct nl_handle *handle, int rxbuf, int txbuf)</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Set socket buffer size of netlink handle. <a href="#ga0b6d4741ee2ec8f0392b600a626ff1fd"></a><br/></td></tr>
<tr><td class="memItemLeft" align="right" valign="top">int </td><td class="memItemRight" valign="bottom"><a class="el" href="group__socket.html#ga4caab1fb14937565d7b38b57742a82ce">nl_set_passcred</a> (struct nl_handle *handle, int state)</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Enable/disable credential passing on netlink handle. <a href="#ga4caab1fb14937565d7b38b57742a82ce"></a><br/></td></tr>
<tr><td class="memItemLeft" align="right" valign="top">int </td><td class="memItemRight" valign="bottom"><a class="el" href="group__socket.html#gaf2962e6065572d8da9a4cde6b7672f39">nl_socket_recv_pktinfo</a> (struct nl_handle *handle, int state)</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Enable/disable receival of additional packet information. <a href="#gaf2962e6065572d8da9a4cde6b7672f39"></a><br/></td></tr>
</table>
<hr/><a name="_details"></a><h2>Detailed Description</h2>
<p>The socket is represented in a structure called the netlink handle, besides the socket, it stores various settings and values related to the socket. Every socket handle has a mandatory association with a set of callbacks which can be used to modify the behaviour when sending/receiving data from the socket.</p>
<dl class="user"><dt><b>Socket Attributes</b></dt><dd><ul>
<li><b>Local</b> <b>Port:</b> The local port is a netlink port identifying the local endpoint. It is used as source address for outgoing messages and will be addressed in replies. It must therefore be unique among all userspace applications. When the socket handle is allocated, a unique port number is generated automatically in the form of 22 bits Process Identifier + 10 bits Arbitary Number. Therefore the library is capable of generating 1024 unique local port numbers for every process. If more sockets are required, the application has to manage port numbers itself using <a class="el" href="group__socket.html#ga9cf7b89ddc00d1c9d7c0f00437c27e6b" title="Set local port of socket.">nl_socket_set_local_port()</a>.</li>
<li><b>Group</b> <b>Subscriptions:</b> A socket can subscribe to any number of multicast groups. It will then receive a copy of all messages sent to one of the groups. This method is mainly used for event notification. Prior to kernel 2.6.14, the group subscription was done via bitmask which limited to a total number of groups of 32. With 2.6.14 a new method was added based on continous identifiers which supports an arbitary number of groups. Both methods are supported, see <a class="el" href="group__socket.html#gab6a2c1fb173efe3696184bdb2c5f5ae7" title="Join multicast groups (deprecated)">nl_join_groups()</a> respectively <a class="el" href="group__socket.html#ga3d0fb09feebd7fe9d919437aef47239a" title="Join a group.">nl_socket_add_membership()</a> and <a class="el" href="group__socket.html#ga0114b0736393662d10296a0480ebd49d" title="Leave a group.">nl_socket_drop_membership()</a>.</li>
<li><b>Peer</b> <b>Port:</b> The peer port is a netlink port identifying the peer's endpoint. If no peer port is specified, the kernel will try to autobind to a socket of the specified netlink family automatically. This is very common as typically only one listening socket exists on the kernel side. The peer port can be modified using nl_socket_set_peer_port().</li>
<li><b>Peer</b> <b>Groups:</b> </li>
<li><b>File</b> <b>Descriptor:</b> The file descriptor of the socket, it can be accessed via nl_socket_get_fd() to change socket options or monitor activity using poll()/select().</li>
<li><b>Protocol:</b> Once connected, the socket is bound to stick to one netlink family. This field is invisible, it is maintained automatically. (See <a class="el" href="group__nl.html#ga68655d7fa8bd1944bec4761c95e576e9" title="Create and connect netlink socket.">nl_connect()</a>)</li>
<li><b>Next</b> <b>Sequence</b> <b>Number:</b> Next available sequence number to be used for the next message being sent out. (Initial value: UNIX time when the socket was allocated.) Sequence numbers can be used via <a class="el" href="group__socket.html#ga92142abf81ef25b2518528dc9f82ce98" title="Use next sequence number.">nl_socket_use_seq()</a>.</li>
<li><b>Expected</b> <b>Sequence</b> <b>Number:</b> Expected sequence number in the next message received from the socket. (Initial value: Equal to next sequence number.)</li>
<li><b>Callbacks</b> <b>Configuration:</b> </li>
</ul>
</dd></dl>
<dl class="user"><dt><b>1) Creating the netlink handle</b></dt><dd><div class="fragment"><pre class="fragment"> <span class="keyword">struct </span>nl_handle *handle;
<span class="comment">// Allocate and initialize a new netlink handle</span>
handle = <a class="code" href="group__socket.html#gaf903c9ea089735b1ba8e40dae801c47d" title="Allocate new netlink socket handle.">nl_handle_alloc</a>();
<span class="comment">// Use nl_socket_get_fd() to fetch the file description, for example to</span>
<span class="comment">// put a socket into non-blocking i/o mode.</span>
fcntl(nl_socket_get_fd(handle), F_SETFL, O_NONBLOCK);
</pre></div></dd></dl>
<dl class="user"><dt><b>2) Group Subscriptions</b></dt><dd><div class="fragment"><pre class="fragment"> <span class="comment">// Event notifications are typically sent to multicast addresses which</span>
<span class="comment">// represented by groups. Join a group to f.e. receive link notifications.</span>
<a class="code" href="group__socket.html#ga3d0fb09feebd7fe9d919437aef47239a" title="Join a group.">nl_socket_add_membership</a>(handle, RTNLGRP_LINK);
</pre></div></dd></dl>
<dl class="user"><dt><b>6) Cleaning up</b></dt><dd><div class="fragment"><pre class="fragment"> <span class="comment">// Finally destroy the netlink handle</span>
<a class="code" href="group__socket.html#gaf73c4d1d895ec4cd19f504aae96219b5" title="Destroy netlink handle.">nl_handle_destroy</a>(handle);
</pre></div> </dd></dl>
<hr/><h2>Function Documentation</h2>
<a class="anchor" id="gaf903c9ea089735b1ba8e40dae801c47d"></a><!-- doxytag: member="socket.c::nl_handle_alloc" ref="gaf903c9ea089735b1ba8e40dae801c47d" args="(void)" -->
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<td class="memname">struct nl_handle* nl_handle_alloc </td>
<td>(</td>
<td class="paramtype">void </td>
<td class="paramname"></td><td>)</td>
<td><code> [read]</code></td>
</tr>
</table>
</div>
<div class="memdoc">
<dl class="return"><dt><b>Returns:</b></dt><dd>Newly allocated netlink socket handle or NULL. </dd></dl>
<p>Definition at line <a class="el" href="socket_8c_source.html#l00206">206</a> of file <a class="el" href="socket_8c_source.html">socket.c</a>.</p>
<p>References <a class="el" href="handlers_8c_source.html#l00255">nl_cb_alloc()</a>.</p>
<div class="fragment"><pre class="fragment">{
<span class="keyword">struct </span>nl_cb *cb;
cb = <a class="code" href="group__cb.html#gaea2e77b9e3c0c875f44aec236d9a1009" title="Allocate a new callback handle.">nl_cb_alloc</a>(default_cb);
<span class="keywordflow">if</span> (!cb) {
nl_errno(ENOMEM);
<span class="keywordflow">return</span> NULL;
}
<span class="keywordflow">return</span> __alloc_handle(cb);
}
</pre></div>
</div>
</div>
<a class="anchor" id="gaeae22da82a96561d9b89fb67763c258d"></a><!-- doxytag: member="socket.c::nl_handle_alloc_cb" ref="gaeae22da82a96561d9b89fb67763c258d" args="(struct nl_cb *cb)" -->
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<td class="memname">struct nl_handle* nl_handle_alloc_cb </td>
<td>(</td>
<td class="paramtype">struct nl_cb * </td>
<td class="paramname"><em>cb</em></td><td>)</td>
<td><code> [read]</code></td>
</tr>
</table>
</div>
<div class="memdoc">
<dl><dt><b>Parameters:</b></dt><dd>
<table class="params">
<tr><td class="paramname">cb</td><td>Callback handler</td></tr>
</table>
</dd>
</dl>
<p>The reference to the callback handler is taken into account automatically, it is released again upon calling <a class="el" href="group__socket.html#gaf73c4d1d895ec4cd19f504aae96219b5" title="Destroy netlink handle.">nl_handle_destroy()</a>.</p>
<dl class="return"><dt><b>Returns:</b></dt><dd>Newly allocted socket handle or NULL. </dd></dl>
<p>Definition at line <a class="el" href="socket_8c_source.html#l00228">228</a> of file <a class="el" href="socket_8c_source.html">socket.c</a>.</p>
<div class="fragment"><pre class="fragment">{
<span class="keywordflow">if</span> (cb == NULL)
BUG();
<span class="keywordflow">return</span> __alloc_handle(nl_cb_get(cb));
}
</pre></div>
</div>
</div>
<a class="anchor" id="gaf73c4d1d895ec4cd19f504aae96219b5"></a><!-- doxytag: member="socket.c::nl_handle_destroy" ref="gaf73c4d1d895ec4cd19f504aae96219b5" args="(struct nl_handle *handle)" -->
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<td class="memname">void nl_handle_destroy </td>
<td>(</td>
<td class="paramtype">struct nl_handle * </td>
<td class="paramname"><em>handle</em></td><td>)</td>
<td></td>
</tr>
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<div class="memdoc">
<dl><dt><b>Parameters:</b></dt><dd>
<table class="params">
<tr><td class="paramname">handle</td><td>Netlink handle. </td></tr>
</table>
</dd>
</dl>
<p>Definition at line <a class="el" href="socket_8c_source.html#l00240">240</a> of file <a class="el" href="socket_8c_source.html">socket.c</a>.</p>
<p>Referenced by <a class="el" href="cache__mngr_8c_source.html#l00373">nl_cache_mngr_free()</a>.</p>
<div class="fragment"><pre class="fragment">{
<span class="keywordflow">if</span> (!handle)
<span class="keywordflow">return</span>;
<span class="keywordflow">if</span> (handle->h_fd >= 0)
close(handle->h_fd);
<span class="keywordflow">if</span> (!(handle->h_flags & NL_OWN_PORT))
release_local_port(handle->h_local.nl_pid);
nl_cb_put(handle->h_cb);
free(handle);
}
</pre></div>
</div>
</div>
<a class="anchor" id="ga0ff2f43147e3a4547f7109578b3ca422"></a><!-- doxytag: member="socket.c::nl_disable_sequence_check" ref="ga0ff2f43147e3a4547f7109578b3ca422" args="(struct nl_handle *handle)" -->
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<td class="memname">void nl_disable_sequence_check </td>
<td>(</td>
<td class="paramtype">struct nl_handle * </td>
<td class="paramname"><em>handle</em></td><td>)</td>
<td></td>
</tr>
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</div>
<div class="memdoc">
<dl><dt><b>Parameters:</b></dt><dd>
<table class="params">
<tr><td class="paramname">handle</td><td>Netlink handle.</td></tr>
</table>
</dd>
</dl>
<p>Disables checking of sequence numbers on the netlink handle. This is required to allow messages to be processed which were not requested by a preceding request message, e.g. netlink events.</p>
<dl class="note"><dt><b>Note:</b></dt><dd>This function modifies the NL_CB_SEQ_CHECK configuration in the callback handle associated with the socket. </dd></dl>
<p>Definition at line <a class="el" href="socket_8c_source.html#l00279">279</a> of file <a class="el" href="socket_8c_source.html">socket.c</a>.</p>
<p>References <a class="el" href="handlers_8h_source.html#l00083">NL_CB_CUSTOM</a>, <a class="el" href="handlers_8h_source.html#l00111">NL_CB_SEQ_CHECK</a>, and <a class="el" href="handlers_8c_source.html#l00337">nl_cb_set()</a>.</p>
<p>Referenced by <a class="el" href="cache__mngr_8c_source.html#l00149">nl_cache_mngr_alloc()</a>.</p>
<div class="fragment"><pre class="fragment">{
<a class="code" href="group__cb.html#gabe7b2516f28fbb8bb9c5b1ea2dfaf1d3" title="Set up a callback.">nl_cb_set</a>(handle->h_cb, <a class="code" href="group__cb.html#gga3f60f4515ada826d2bf16395ee722363ae73e906b997f00e8911b09e0f254364d" title="Called instead of internal sequence number checking.">NL_CB_SEQ_CHECK</a>,
<a class="code" href="group__cb.html#ggaba3fabad0c62db483941101e1a18d14da22448271a402b4c4a55733ef4884c038" title="Customized handler specified by the user.">NL_CB_CUSTOM</a>, noop_seq_check, NULL);
}
</pre></div>
</div>
</div>
<a class="anchor" id="ga92142abf81ef25b2518528dc9f82ce98"></a><!-- doxytag: member="socket.c::nl_socket_use_seq" ref="ga92142abf81ef25b2518528dc9f82ce98" args="(struct nl_handle *handle)" -->
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<table class="memname">
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<td class="memname">unsigned int nl_socket_use_seq </td>
<td>(</td>
<td class="paramtype">struct nl_handle * </td>
<td class="paramname"><em>handle</em></td><td>)</td>
<td></td>
</tr>
</table>
</div>
<div class="memdoc">
<dl><dt><b>Parameters:</b></dt><dd>
<table class="params">
<tr><td class="paramname">handle</td><td>Netlink handle</td></tr>
</table>
</dd>
</dl>
<p>Uses the next available sequence number and increases the counter by one for subsequent calls.</p>
<dl class="return"><dt><b>Returns:</b></dt><dd>Unique serial sequence number </dd></dl>
<p>Definition at line <a class="el" href="socket_8c_source.html#l00294">294</a> of file <a class="el" href="socket_8c_source.html">socket.c</a>.</p>
<div class="fragment"><pre class="fragment">{
<span class="keywordflow">return</span> handle->h_seq_next++;
}
</pre></div>
</div>
</div>
<a class="anchor" id="ga9cf7b89ddc00d1c9d7c0f00437c27e6b"></a><!-- doxytag: member="socket.c::nl_socket_set_local_port" ref="ga9cf7b89ddc00d1c9d7c0f00437c27e6b" args="(struct nl_handle *handle, uint32_t port)" -->
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<td class="memname">void nl_socket_set_local_port </td>
<td>(</td>
<td class="paramtype">struct nl_handle * </td>
<td class="paramname"><em>handle</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">uint32_t </td>
<td class="paramname"><em>port</em> </td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td></td>
</tr>
</table>
</div>
<div class="memdoc">
<dl><dt><b>Parameters:</b></dt><dd>
<table class="params">
<tr><td class="paramname">handle</td><td>Netlink handle </td></tr>
<tr><td class="paramname">port</td><td>Local port identifier</td></tr>
</table>
</dd>
</dl>
<p>Assigns a local port identifier to the socket. If port is 0 a unique port identifier will be generated automatically. </p>
<p>Definition at line <a class="el" href="socket_8c_source.html#l00319">319</a> of file <a class="el" href="socket_8c_source.html">socket.c</a>.</p>
<div class="fragment"><pre class="fragment">{
<span class="keywordflow">if</span> (port == 0) {
port = generate_local_port();
handle->h_flags &= ~NL_OWN_PORT;
} <span class="keywordflow">else</span> {
<span class="keywordflow">if</span> (!(handle->h_flags & NL_OWN_PORT))
release_local_port(handle->h_local.nl_pid);
handle->h_flags |= NL_OWN_PORT;
}
handle->h_local.nl_pid = port;
}
</pre></div>
</div>
</div>
<a class="anchor" id="ga3d0fb09feebd7fe9d919437aef47239a"></a><!-- doxytag: member="socket.c::nl_socket_add_membership" ref="ga3d0fb09feebd7fe9d919437aef47239a" args="(struct nl_handle *handle, int group)" -->
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<td class="memname">int nl_socket_add_membership </td>
<td>(</td>
<td class="paramtype">struct nl_handle * </td>
<td class="paramname"><em>handle</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">int </td>
<td class="paramname"><em>group</em> </td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td></td>
</tr>
</table>
</div>
<div class="memdoc">
<dl><dt><b>Parameters:</b></dt><dd>
<table class="params">
<tr><td class="paramname">handle</td><td>Netlink handle </td></tr>
<tr><td class="paramname">group</td><td>Group identifier</td></tr>
</table>
</dd>
</dl>
<p>Joins the specified group using the modern socket option which is available since kernel version 2.6.14. It allows joining an almost arbitary number of groups without limitation.</p>
<p>Make sure to use the correct group definitions as the older bitmask definitions for <a class="el" href="group__socket.html#gab6a2c1fb173efe3696184bdb2c5f5ae7" title="Join multicast groups (deprecated)">nl_join_groups()</a> are likely to still be present for backward compatibility reasons.</p>
<dl class="return"><dt><b>Returns:</b></dt><dd>0 on sucess or a negative error code. </dd></dl>
<p>Definition at line <a class="el" href="socket_8c_source.html#l00355">355</a> of file <a class="el" href="socket_8c_source.html">socket.c</a>.</p>
<p>Referenced by <a class="el" href="cache__mngr_8c_source.html#l00209">nl_cache_mngr_add()</a>.</p>
<div class="fragment"><pre class="fragment">{
<span class="keywordtype">int</span> err;
<span class="keywordflow">if</span> (handle->h_fd == -1)
<span class="keywordflow">return</span> nl_error(EBADFD, <span class="stringliteral">"Socket not connected"</span>);
err = setsockopt(handle->h_fd, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP,
&group, <span class="keyword">sizeof</span>(group));
<span class="keywordflow">if</span> (err < 0)
<span class="keywordflow">return</span> nl_error(errno, <span class="stringliteral">"setsockopt(NETLINK_ADD_MEMBERSHIP) "</span>
<span class="stringliteral">"failed"</span>);
<span class="keywordflow">return</span> 0;
}
</pre></div>
</div>
</div>
<a class="anchor" id="ga0114b0736393662d10296a0480ebd49d"></a><!-- doxytag: member="socket.c::nl_socket_drop_membership" ref="ga0114b0736393662d10296a0480ebd49d" args="(struct nl_handle *handle, int group)" -->
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<td class="memname">int nl_socket_drop_membership </td>
<td>(</td>
<td class="paramtype">struct nl_handle * </td>
<td class="paramname"><em>handle</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">int </td>
<td class="paramname"><em>group</em> </td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td></td>
</tr>
</table>
</div>
<div class="memdoc">
<dl><dt><b>Parameters:</b></dt><dd>
<table class="params">
<tr><td class="paramname">handle</td><td>Netlink handle </td></tr>
<tr><td class="paramname">group</td><td>Group identifier</td></tr>
</table>
</dd>
</dl>
<p>Leaves the specified group using the modern socket option which is available since kernel version 2.6.14.</p>
<dl class="see"><dt><b>See also:</b></dt><dd><a class="el" href="group__socket.html#ga3d0fb09feebd7fe9d919437aef47239a" title="Join a group.">nl_socket_add_membership</a> </dd></dl>
<dl class="return"><dt><b>Returns:</b></dt><dd>0 on success or a negative error code. </dd></dl>
<p>Definition at line <a class="el" href="socket_8c_source.html#l00382">382</a> of file <a class="el" href="socket_8c_source.html">socket.c</a>.</p>
<p>Referenced by <a class="el" href="cache__mngr_8c_source.html#l00209">nl_cache_mngr_add()</a>.</p>
<div class="fragment"><pre class="fragment">{
<span class="keywordtype">int</span> err;
<span class="keywordflow">if</span> (handle->h_fd == -1)
<span class="keywordflow">return</span> nl_error(EBADFD, <span class="stringliteral">"Socket not connected"</span>);
err = setsockopt(handle->h_fd, SOL_NETLINK, NETLINK_DROP_MEMBERSHIP,
&group, <span class="keyword">sizeof</span>(group));
<span class="keywordflow">if</span> (err < 0)
<span class="keywordflow">return</span> nl_error(errno, <span class="stringliteral">"setsockopt(NETLINK_DROP_MEMBERSHIP) "</span>
<span class="stringliteral">"failed"</span>);
<span class="keywordflow">return</span> 0;
}
</pre></div>
</div>
</div>
<a class="anchor" id="gab6a2c1fb173efe3696184bdb2c5f5ae7"></a><!-- doxytag: member="socket.c::nl_join_groups" ref="gab6a2c1fb173efe3696184bdb2c5f5ae7" args="(struct nl_handle *handle, int groups)" -->
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<td class="memname">void nl_join_groups </td>
<td>(</td>
<td class="paramtype">struct nl_handle * </td>
<td class="paramname"><em>handle</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">int </td>
<td class="paramname"><em>groups</em> </td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td></td>
</tr>
</table>
</div>
<div class="memdoc">
<dl><dt><b>Parameters:</b></dt><dd>
<table class="params">
<tr><td class="paramname">handle</td><td>Netlink handle. </td></tr>
<tr><td class="paramname">groups</td><td>Bitmask of groups to join.</td></tr>
</table>
</dd>
</dl>
<p>This function defines the old way of joining multicast group which has to be done prior to calling <a class="el" href="group__nl.html#ga68655d7fa8bd1944bec4761c95e576e9" title="Create and connect netlink socket.">nl_connect()</a>. It works on any kernel version but is very limited as only 32 groups can be joined. </p>
<p>Definition at line <a class="el" href="socket_8c_source.html#l00407">407</a> of file <a class="el" href="socket_8c_source.html">socket.c</a>.</p>
<div class="fragment"><pre class="fragment">{
handle->h_local.nl_groups |= groups;
}
</pre></div>
</div>
</div>
<a class="anchor" id="gafbf20258be9d18116a9179c76cdd2637"></a><!-- doxytag: member="socket.c::nl_socket_set_nonblocking" ref="gafbf20258be9d18116a9179c76cdd2637" args="(struct nl_handle *handle)" -->
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<td class="memname">int nl_socket_set_nonblocking </td>
<td>(</td>
<td class="paramtype">struct nl_handle * </td>
<td class="paramname"><em>handle</em></td><td>)</td>
<td></td>
</tr>
</table>
</div>
<div class="memdoc">
<dl><dt><b>Parameters:</b></dt><dd>
<table class="params">
<tr><td class="paramname">handle</td><td>Netlink socket</td></tr>
</table>
</dd>
</dl>
<dl class="return"><dt><b>Returns:</b></dt><dd>0 on success or a negative error code. </dd></dl>
<p>Definition at line <a class="el" href="socket_8c_source.html#l00448">448</a> of file <a class="el" href="socket_8c_source.html">socket.c</a>.</p>
<p>Referenced by <a class="el" href="cache__mngr_8c_source.html#l00149">nl_cache_mngr_alloc()</a>.</p>
<div class="fragment"><pre class="fragment">{
<span class="keywordflow">if</span> (handle->h_fd == -1)
<span class="keywordflow">return</span> nl_error(EBADFD, <span class="stringliteral">"Socket not connected"</span>);
<span class="keywordflow">if</span> (fcntl(handle->h_fd, F_SETFL, O_NONBLOCK) < 0)
<span class="keywordflow">return</span> nl_error(errno, <span class="stringliteral">"fcntl(F_SETFL, O_NONBLOCK) failed"</span>);
<span class="keywordflow">return</span> 0;
}
</pre></div>
</div>
</div>
<a class="anchor" id="ga6dcc8125ee5726e240d8c04b2b83df2f"></a><!-- doxytag: member="socket.c::nl_socket_enable_msg_peek" ref="ga6dcc8125ee5726e240d8c04b2b83df2f" args="(struct nl_handle *handle)" -->
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<td class="memname">void nl_socket_enable_msg_peek </td>
<td>(</td>
<td class="paramtype">struct nl_handle * </td>
<td class="paramname"><em>handle</em></td><td>)</td>
<td></td>
</tr>
</table>
</div>
<div class="memdoc">
<dl><dt><b>Parameters:</b></dt><dd>
<table class="params">
<tr><td class="paramname">handle</td><td>Netlink socket </td></tr>
</table>
</dd>
</dl>
<p>Definition at line <a class="el" href="socket_8c_source.html#l00463">463</a> of file <a class="el" href="socket_8c_source.html">socket.c</a>.</p>
<div class="fragment"><pre class="fragment">{
handle->h_flags |= NL_MSG_PEEK;
}
</pre></div>
</div>
</div>
<a class="anchor" id="gaa385f5778249903909a0016f89044faa"></a><!-- doxytag: member="socket.c::nl_socket_disable_msg_peek" ref="gaa385f5778249903909a0016f89044faa" args="(struct nl_handle *handle)" -->
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<td class="memname">void nl_socket_disable_msg_peek </td>
<td>(</td>
<td class="paramtype">struct nl_handle * </td>
<td class="paramname"><em>handle</em></td><td>)</td>
<td></td>
</tr>
</table>
</div>
<div class="memdoc">
<dl><dt><b>Parameters:</b></dt><dd>
<table class="params">
<tr><td class="paramname">handle</td><td>Netlink socket </td></tr>
</table>
</dd>
</dl>
<p>Definition at line <a class="el" href="socket_8c_source.html#l00472">472</a> of file <a class="el" href="socket_8c_source.html">socket.c</a>.</p>
<div class="fragment"><pre class="fragment">{
handle->h_flags &= ~NL_MSG_PEEK;
}
</pre></div>
</div>
</div>
<a class="anchor" id="ga6ae4e46ad6ea991e92dd0cc2653ff371"></a><!-- doxytag: member="socket.c::nl_socket_modify_cb" ref="ga6ae4e46ad6ea991e92dd0cc2653ff371" args="(struct nl_handle *handle, enum nl_cb_type type, enum nl_cb_kind kind, nl_recvmsg_msg_cb_t func, void *arg)" -->
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<td class="memname">int nl_socket_modify_cb </td>
<td>(</td>
<td class="paramtype">struct nl_handle * </td>
<td class="paramname"><em>handle</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">enum <a class="el" href="group__cb.html#ga3f60f4515ada826d2bf16395ee722363">nl_cb_type</a> </td>
<td class="paramname"><em>type</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">enum <a class="el" href="group__cb.html#gaba3fabad0c62db483941101e1a18d14d">nl_cb_kind</a> </td>
<td class="paramname"><em>kind</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype"><a class="el" href="group__cb.html#ga1bf04ce17ab1b5867017556a6b4ba729">nl_recvmsg_msg_cb_t</a> </td>
<td class="paramname"><em>func</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">void * </td>
<td class="paramname"><em>arg</em> </td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td></td>
</tr>
</table>
</div>
<div class="memdoc">
<dl><dt><b>Parameters:</b></dt><dd>
<table class="params">
<tr><td class="paramname">handle</td><td>netlink handle </td></tr>
<tr><td class="paramname">type</td><td>which type callback to set </td></tr>
<tr><td class="paramname">kind</td><td>kind of callback </td></tr>
<tr><td class="paramname">func</td><td>callback function </td></tr>
<tr><td class="paramname">arg</td><td>argument to be passwd to callback function</td></tr>
</table>
</dd>
</dl>
<dl class="see"><dt><b>See also:</b></dt><dd><a class="el" href="group__cb.html#gabe7b2516f28fbb8bb9c5b1ea2dfaf1d3" title="Set up a callback.">nl_cb_set</a> </dd></dl>
<p>Definition at line <a class="el" href="socket_8c_source.html#l00505">505</a> of file <a class="el" href="socket_8c_source.html">socket.c</a>.</p>
<p>References <a class="el" href="handlers_8c_source.html#l00337">nl_cb_set()</a>.</p>
<p>Referenced by <a class="el" href="cache__mngr_8c_source.html#l00149">nl_cache_mngr_alloc()</a>.</p>
<div class="fragment"><pre class="fragment">{
<span class="keywordflow">return</span> <a class="code" href="group__cb.html#gabe7b2516f28fbb8bb9c5b1ea2dfaf1d3" title="Set up a callback.">nl_cb_set</a>(handle->h_cb, type, kind, func, arg);
}
</pre></div>
</div>
</div>
<a class="anchor" id="ga0b6d4741ee2ec8f0392b600a626ff1fd"></a><!-- doxytag: member="socket.c::nl_set_buffer_size" ref="ga0b6d4741ee2ec8f0392b600a626ff1fd" args="(struct nl_handle *handle, int rxbuf, int txbuf)" -->
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<td class="memname">int nl_set_buffer_size </td>
<td>(</td>
<td class="paramtype">struct nl_handle * </td>
<td class="paramname"><em>handle</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">int </td>
<td class="paramname"><em>rxbuf</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">int </td>
<td class="paramname"><em>txbuf</em> </td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td></td>
</tr>
</table>
</div>
<div class="memdoc">
<dl><dt><b>Parameters:</b></dt><dd>
<table class="params">
<tr><td class="paramname">handle</td><td>Netlink handle. </td></tr>
<tr><td class="paramname">rxbuf</td><td>New receive socket buffer size in bytes. </td></tr>
<tr><td class="paramname">txbuf</td><td>New transmit socket buffer size in bytes.</td></tr>
</table>
</dd>
</dl>
<p>Sets the socket buffer size of a netlink handle to the specified values <code>rxbuf</code> and <code>txbuf</code>. Providing a value of <code>0</code> assumes a good default value.</p>
<dl class="note"><dt><b>Note:</b></dt><dd>It is not required to call this function prior to <a class="el" href="group__nl.html#ga68655d7fa8bd1944bec4761c95e576e9" title="Create and connect netlink socket.">nl_connect()</a>. </dd></dl>
<dl class="return"><dt><b>Returns:</b></dt><dd>0 on sucess or a negative error code. </dd></dl>
<p>Definition at line <a class="el" href="socket_8c_source.html#l00532">532</a> of file <a class="el" href="socket_8c_source.html">socket.c</a>.</p>
<p>Referenced by <a class="el" href="nl_8c_source.html#l00191">nl_connect()</a>.</p>
<div class="fragment"><pre class="fragment">{
<span class="keywordtype">int</span> err;
<span class="keywordflow">if</span> (rxbuf <= 0)
rxbuf = 32768;
<span class="keywordflow">if</span> (txbuf <= 0)
txbuf = 32768;
<span class="keywordflow">if</span> (handle->h_fd == -1)
<span class="keywordflow">return</span> nl_error(EBADFD, <span class="stringliteral">"Socket not connected"</span>);
err = setsockopt(handle->h_fd, SOL_SOCKET, SO_SNDBUF,
&txbuf, <span class="keyword">sizeof</span>(txbuf));
<span class="keywordflow">if</span> (err < 0)
<span class="keywordflow">return</span> nl_error(errno, <span class="stringliteral">"setsockopt(SO_SNDBUF) failed"</span>);
err = setsockopt(handle->h_fd, SOL_SOCKET, SO_RCVBUF,
&rxbuf, <span class="keyword">sizeof</span>(rxbuf));
<span class="keywordflow">if</span> (err < 0)
<span class="keywordflow">return</span> nl_error(errno, <span class="stringliteral">"setsockopt(SO_RCVBUF) failed"</span>);
handle->h_flags |= NL_SOCK_BUFSIZE_SET;
<span class="keywordflow">return</span> 0;
}
</pre></div>
</div>
</div>
<a class="anchor" id="ga4caab1fb14937565d7b38b57742a82ce"></a><!-- doxytag: member="socket.c::nl_set_passcred" ref="ga4caab1fb14937565d7b38b57742a82ce" args="(struct nl_handle *handle, int state)" -->
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<td class="memname">int nl_set_passcred </td>
<td>(</td>
<td class="paramtype">struct nl_handle * </td>
<td class="paramname"><em>handle</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">int </td>
<td class="paramname"><em>state</em> </td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td></td>
</tr>
</table>
</div>
<div class="memdoc">
<dl><dt><b>Parameters:</b></dt><dd>
<table class="params">
<tr><td class="paramname">handle</td><td>Netlink handle </td></tr>
<tr><td class="paramname">state</td><td>New state (0 - disabled, 1 - enabled)</td></tr>
</table>
</dd>
</dl>
<dl class="return"><dt><b>Returns:</b></dt><dd>0 on success or a negative error code </dd></dl>
<p>Definition at line <a class="el" href="socket_8c_source.html#l00567">567</a> of file <a class="el" href="socket_8c_source.html">socket.c</a>.</p>
<div class="fragment"><pre class="fragment">{
<span class="keywordtype">int</span> err;
<span class="keywordflow">if</span> (handle->h_fd == -1)
<span class="keywordflow">return</span> nl_error(EBADFD, <span class="stringliteral">"Socket not connected"</span>);
err = setsockopt(handle->h_fd, SOL_SOCKET, SO_PASSCRED,
&state, <span class="keyword">sizeof</span>(state));
<span class="keywordflow">if</span> (err < 0)
<span class="keywordflow">return</span> nl_error(errno, <span class="stringliteral">"setsockopt(SO_PASSCRED) failed"</span>);
<span class="keywordflow">if</span> (state)
handle->h_flags |= NL_SOCK_PASSCRED;
<span class="keywordflow">else</span>
handle->h_flags &= ~NL_SOCK_PASSCRED;
<span class="keywordflow">return</span> 0;
}
</pre></div>
</div>
</div>
<a class="anchor" id="gaf2962e6065572d8da9a4cde6b7672f39"></a><!-- doxytag: member="socket.c::nl_socket_recv_pktinfo" ref="gaf2962e6065572d8da9a4cde6b7672f39" args="(struct nl_handle *handle, int state)" -->
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">int nl_socket_recv_pktinfo </td>
<td>(</td>
<td class="paramtype">struct nl_handle * </td>
<td class="paramname"><em>handle</em>, </td>
</tr>
<tr>
<td class="paramkey"></td>
<td></td>
<td class="paramtype">int </td>
<td class="paramname"><em>state</em> </td>
</tr>
<tr>
<td></td>
<td>)</td>
<td></td><td></td>
</tr>
</table>
</div>
<div class="memdoc">
<dl><dt><b>Parameters:</b></dt><dd>
<table class="params">
<tr><td class="paramname">handle</td><td>Netlink handle </td></tr>
<tr><td class="paramname">state</td><td>New state (0 - disabled, 1 - enabled)</td></tr>
</table>
</dd>
</dl>
<dl class="return"><dt><b>Returns:</b></dt><dd>0 on success or a negative error code </dd></dl>
<p>Definition at line <a class="el" href="socket_8c_source.html#l00594">594</a> of file <a class="el" href="socket_8c_source.html">socket.c</a>.</p>
<div class="fragment"><pre class="fragment">{
<span class="keywordtype">int</span> err;
<span class="keywordflow">if</span> (handle->h_fd == -1)
<span class="keywordflow">return</span> nl_error(EBADFD, <span class="stringliteral">"Socket not connected"</span>);
err = setsockopt(handle->h_fd, SOL_NETLINK, NETLINK_PKTINFO,
&state, <span class="keyword">sizeof</span>(state));
<span class="keywordflow">if</span> (err < 0)
<span class="keywordflow">return</span> nl_error(errno, <span class="stringliteral">"setsockopt(NETLINK_PKTINFO) failed"</span>);
<span class="keywordflow">return</span> 0;
}
</pre></div>
</div>
</div>
</div>
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