adam/metasploit-gs
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
Files
c3f5bd3de2d1affa01e2f6c2066c6bb0fc6413bc
metasploit-gs/api/Msf/Exploit/Remote/SNMPClient.html
T
jenkins-metasploit c3f5bd3de2 Reboot gh-pages
2026-05-08 17:08:43 +00:00

630 lines
24 KiB
HTML
Raw Blame History

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>
Module: Msf::Exploit::Remote::SNMPClient
&mdash; Documentation by YARD 0.9.37
</title>
<link rel="stylesheet" href="../../../css/style.css" type="text/css" />
<link rel="stylesheet" href="../../../css/common.css" type="text/css" />
<script type="text/javascript">
pathId = "Msf::Exploit::Remote::SNMPClient";
relpath = '../../../';
</script>
<script type="text/javascript" charset="utf-8" src="../../../js/jquery.js"></script>
<script type="text/javascript" charset="utf-8" src="../../../js/app.js"></script>
</head>
<body>
<div class="nav_wrap">
<iframe id="nav" src="../../../class_list.html?1"></iframe>
<div id="resizer"></div>
</div>
<div id="main" tabindex="-1">
<div id="header">
<div id="menu">
<a href="../../../_index.html">Index (S)</a> &raquo;
<span class='title'><span class='object_link'><a href="../../../Msf.html" title="Msf (module)">Msf</a></span></span> &raquo; <span class='title'><span class='object_link'><a href="../../Exploit.html" title="Msf::Exploit (class)">Exploit</a></span></span> &raquo; <span class='title'><span class='object_link'><a href="../Remote.html" title="Msf::Exploit::Remote (class)">Remote</a></span></span>
&raquo;
<span class="title">SNMPClient</span>
</div>
<div id="search">
<a class="full_list_link" id="class_list_link"
href="../../../class_list.html">
<svg width="24" height="24">
<rect x="0" y="4" width="24" height="4" rx="1" ry="1"></rect>
<rect x="0" y="12" width="24" height="4" rx="1" ry="1"></rect>
<rect x="0" y="20" width="24" height="4" rx="1" ry="1"></rect>
</svg>
</a>
</div>
<div class="clear"></div>
</div>
<div id="content"><h1>Module: Msf::Exploit::Remote::SNMPClient
</h1>
<div class="box_info">
<dl>
<dt>Includes:</dt>
<dd><span class='object_link'><a href="Udp.html" title="Msf::Exploit::Remote::Udp (module)">Udp</a></span></dd>
</dl>
<dl>
<dt>Defined in:</dt>
<dd>lib/msf/core/exploit/remote/snmp_client.rb</dd>
</dl>
</div>
<h2>Overview</h2><div class="docstring">
<div class="discussion">
<p>This module exposes methods for querying a SNMP service</p>
</div>
</div>
<div class="tags">
</div>
<h2>Instance Attribute Summary <small><a href="#" class="summary_toggle">collapse</a></small></h2>
<ul class="summary">
<li class="protected ">
<span class="summary_signature">
<a href="#snmp-instance_method" title="#snmp (instance method)">#<strong>snmp</strong> &#x21d2; Object </a>
</span>
<span class="note title protected">protected</span>
<span class="summary_desc"><div class='inline'>
<p>Returns the value of attribute snmp.</p>
</div></span>
</li>
</ul>
<h3 class="inherited">Attributes included from <span class='object_link'><a href="Udp.html" title="Msf::Exploit::Remote::Udp (module)">Udp</a></span></h3>
<p class="inherited"><span class='object_link'><a href="Udp.html#udp_sock-instance_method" title="Msf::Exploit::Remote::Udp#udp_sock (method)">#udp_sock</a></span></p>
<h2>
Instance Method Summary
<small><a href="#" class="summary_toggle">collapse</a></small>
</h2>
<ul class="summary">
<li class="public ">
<span class="summary_signature">
<a href="#community-instance_method" title="#community (instance method)">#<strong>community</strong> &#x21d2; Object </a>
</span>
<span class="summary_desc"><div class='inline'></div></span>
</li>
<li class="public ">
<span class="summary_signature">
<a href="#connect_snmp-instance_method" title="#connect_snmp (instance method)">#<strong>connect_snmp</strong>(global = true, opts = {}) &#x21d2; Object </a>
</span>
<span class="summary_desc"><div class='inline'>
<p>This method wraps the snmp library and passes in the Rex UDP socket.</p>
</div></span>
</li>
<li class="public ">
<span class="summary_signature">
<a href="#disconnect_snmp-instance_method" title="#disconnect_snmp (instance method)">#<strong>disconnect_snmp</strong> &#x21d2; Object </a>
</span>
<span class="summary_desc"><div class='inline'></div></span>
</li>
<li class="public ">
<span class="summary_signature">
<a href="#initialize-instance_method" title="#initialize (instance method)">#<strong>initialize</strong>(info = {}) &#x21d2; Object </a>
</span>
<span class="summary_desc"><div class='inline'>
<p>Creates an instance of a SNMP exploit module.</p>
</div></span>
</li>
<li class="public ">
<span class="summary_signature">
<a href="#retries-instance_method" title="#retries (instance method)">#<strong>retries</strong> &#x21d2; Object </a>
</span>
<span class="summary_desc"><div class='inline'></div></span>
</li>
<li class="public ">
<span class="summary_signature">
<a href="#timeout-instance_method" title="#timeout (instance method)">#<strong>timeout</strong> &#x21d2; Object </a>
</span>
<span class="summary_desc"><div class='inline'></div></span>
</li>
</ul>
<h3 class="inherited">Methods included from <span class='object_link'><a href="Udp.html" title="Msf::Exploit::Remote::Udp (module)">Udp</a></span></h3>
<p class="inherited"><span class='object_link'><a href="Udp.html#chost-instance_method" title="Msf::Exploit::Remote::Udp#chost (method)">#chost</a></span>, <span class='object_link'><a href="Udp.html#cleanup-instance_method" title="Msf::Exploit::Remote::Udp#cleanup (method)">#cleanup</a></span>, <span class='object_link'><a href="Udp.html#connect_udp-instance_method" title="Msf::Exploit::Remote::Udp#connect_udp (method)">#connect_udp</a></span>, <span class='object_link'><a href="Udp.html#cport-instance_method" title="Msf::Exploit::Remote::Udp#cport (method)">#cport</a></span>, <span class='object_link'><a href="Udp.html#deregister_udp_options-instance_method" title="Msf::Exploit::Remote::Udp#deregister_udp_options (method)">#deregister_udp_options</a></span>, <span class='object_link'><a href="Udp.html#disconnect_udp-instance_method" title="Msf::Exploit::Remote::Udp#disconnect_udp (method)">#disconnect_udp</a></span>, <span class='object_link'><a href="Udp.html#handler-instance_method" title="Msf::Exploit::Remote::Udp#handler (method)">#handler</a></span>, <span class='object_link'><a href="Udp.html#lhost-instance_method" title="Msf::Exploit::Remote::Udp#lhost (method)">#lhost</a></span>, <span class='object_link'><a href="Udp.html#lport-instance_method" title="Msf::Exploit::Remote::Udp#lport (method)">#lport</a></span>, <span class='object_link'><a href="Udp.html#rhost-instance_method" title="Msf::Exploit::Remote::Udp#rhost (method)">#rhost</a></span>, <span class='object_link'><a href="Udp.html#rport-instance_method" title="Msf::Exploit::Remote::Udp#rport (method)">#rport</a></span></p>
<div id="instance_attr_details" class="attr_details">
<h2>Instance Attribute Details</h2>
<span id="snmp=-instance_method"></span>
<div class="method_details first">
<h3 class="signature first" id="snmp-instance_method">
#<strong>snmp</strong> &#x21d2; <tt>Object</tt> <span class="extras">(protected)</span>
</h3><div class="docstring">
<div class="discussion">
<p>Returns the value of attribute snmp.</p>
</div>
</div>
<div class="tags">
</div><table class="source_code">
<tr>
<td>
<pre class="lines">
65
66
67</pre>
</td>
<td>
<pre class="code"><span class="info file"># File 'lib/msf/core/exploit/remote/snmp_client.rb', line 65</span>
<span class='kw'>def</span> <span class='id identifier rubyid_snmp'>snmp</span>
<span class='ivar'>@snmp</span>
<span class='kw'>end</span></pre>
</td>
</tr>
</table>
</div>
</div>
<div id="instance_method_details" class="method_details_list">
<h2>Instance Method Details</h2>
<div class="method_details first">
<h3 class="signature first" id="community-instance_method">
#<strong>community</strong> &#x21d2; <tt>Object</tt>
</h3><table class="source_code">
<tr>
<td>
<pre class="lines">
69
70
71</pre>
</td>
<td>
<pre class="code"><span class="info file"># File 'lib/msf/core/exploit/remote/snmp_client.rb', line 69</span>
<span class='kw'>def</span> <span class='id identifier rubyid_community'>community</span>
<span class='id identifier rubyid_datastore'>datastore</span><span class='lbracket'>[</span><span class='tstring'><span class='tstring_beg'>&#39;</span><span class='tstring_content'>COMMUNITY</span><span class='tstring_end'>&#39;</span></span><span class='rbracket'>]</span> <span class='op'>||</span> <span class='tstring'><span class='tstring_beg'>&#39;</span><span class='tstring_content'>public</span><span class='tstring_end'>&#39;</span></span>
<span class='kw'>end</span></pre>
</td>
</tr>
</table>
</div>
<div class="method_details ">
<h3 class="signature " id="connect_snmp-instance_method">
#<strong>connect_snmp</strong>(global = true, opts = {}) &#x21d2; <tt>Object</tt>
</h3><div class="docstring">
<div class="discussion">
<p>This method wraps the snmp library and passes in the Rex UDP socket</p>
</div>
</div>
<div class="tags">
</div><table class="source_code">
<tr>
<td>
<pre class="lines">
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58</pre>
</td>
<td>
<pre class="code"><span class="info file"># File 'lib/msf/core/exploit/remote/snmp_client.rb', line 39</span>
<span class='kw'>def</span> <span class='id identifier rubyid_connect_snmp'>connect_snmp</span><span class='lparen'>(</span><span class='id identifier rubyid_global'>global</span><span class='op'>=</span><span class='kw'>true</span><span class='comma'>,</span> <span class='id identifier rubyid_opts'>opts</span><span class='op'>=</span><span class='lbrace'>{</span><span class='rbrace'>}</span><span class='rparen'>)</span>
<span class='id identifier rubyid_s'>s</span> <span class='op'>=</span> <span class='id identifier rubyid_connect_udp'>connect_udp</span><span class='lparen'>(</span><span class='kw'>false</span><span class='comma'>,</span> <span class='id identifier rubyid_opts'>opts</span><span class='rparen'>)</span>
<span class='id identifier rubyid_version'>version</span> <span class='op'>=</span> <span class='symbol'>:SNMPv1</span> <span class='kw'>if</span> <span class='id identifier rubyid_datastore'>datastore</span><span class='lbracket'>[</span><span class='tstring'><span class='tstring_beg'>&#39;</span><span class='tstring_content'>VERSION</span><span class='tstring_end'>&#39;</span></span><span class='rbracket'>]</span> <span class='op'>==</span> <span class='tstring'><span class='tstring_beg'>&#39;</span><span class='tstring_content'>1</span><span class='tstring_end'>&#39;</span></span>
<span class='id identifier rubyid_version'>version</span> <span class='op'>=</span> <span class='symbol'>:SNMPv2c</span> <span class='kw'>if</span> <span class='id identifier rubyid_datastore'>datastore</span><span class='lbracket'>[</span><span class='tstring'><span class='tstring_beg'>&#39;</span><span class='tstring_content'>VERSION</span><span class='tstring_end'>&#39;</span></span><span class='rbracket'>]</span> <span class='op'>==</span> <span class='tstring'><span class='tstring_beg'>&#39;</span><span class='tstring_content'>2c</span><span class='tstring_end'>&#39;</span></span>
<span class='id identifier rubyid_snmp'>snmp</span> <span class='op'>=</span> <span class='op'>::</span><span class='const'>SNMP</span><span class='op'>::</span><span class='const'>Manager</span><span class='period'>.</span><span class='id identifier rubyid_new'>new</span><span class='lparen'>(</span>
<span class='symbol'>:Host</span> <span class='op'>=&gt;</span> <span class='id identifier rubyid_opts'>opts</span><span class='lbracket'>[</span><span class='tstring'><span class='tstring_beg'>&#39;</span><span class='tstring_content'>RHOST</span><span class='tstring_end'>&#39;</span></span><span class='rbracket'>]</span> <span class='op'>||</span> <span class='id identifier rubyid_rhost'>rhost</span><span class='comma'>,</span>
<span class='symbol'>:Port</span> <span class='op'>=&gt;</span> <span class='id identifier rubyid_opts'>opts</span><span class='lbracket'>[</span><span class='tstring'><span class='tstring_beg'>&#39;</span><span class='tstring_content'>RPORT</span><span class='tstring_end'>&#39;</span></span><span class='rbracket'>]</span> <span class='op'>||</span> <span class='id identifier rubyid_rport'>rport</span><span class='comma'>,</span>
<span class='symbol'>:Community</span> <span class='op'>=&gt;</span> <span class='id identifier rubyid_datastore'>datastore</span><span class='lbracket'>[</span><span class='tstring'><span class='tstring_beg'>&#39;</span><span class='tstring_content'>COMMUNITY</span><span class='tstring_end'>&#39;</span></span><span class='rbracket'>]</span><span class='comma'>,</span>
<span class='symbol'>:Version</span> <span class='op'>=&gt;</span> <span class='id identifier rubyid_version'>version</span><span class='comma'>,</span>
<span class='symbol'>:Timeout</span> <span class='op'>=&gt;</span> <span class='id identifier rubyid_datastore'>datastore</span><span class='lbracket'>[</span><span class='tstring'><span class='tstring_beg'>&#39;</span><span class='tstring_content'>TIMEOUT</span><span class='tstring_end'>&#39;</span></span><span class='rbracket'>]</span><span class='comma'>,</span>
<span class='symbol'>:Retries</span> <span class='op'>=&gt;</span> <span class='id identifier rubyid_datastore'>datastore</span><span class='lbracket'>[</span><span class='tstring'><span class='tstring_beg'>&#39;</span><span class='tstring_content'>RETRIES</span><span class='tstring_end'>&#39;</span></span><span class='rbracket'>]</span><span class='comma'>,</span>
<span class='symbol'>:Transport</span> <span class='op'>=&gt;</span> <span class='const'>SNMP</span><span class='op'>::</span><span class='const'>RexUDPTransport</span><span class='comma'>,</span>
<span class='symbol'>:Socket</span> <span class='op'>=&gt;</span> <span class='id identifier rubyid_s'>s</span>
<span class='rparen'>)</span>
<span class='ivar'>@snmp</span> <span class='op'>=</span> <span class='id identifier rubyid_snmp'>snmp</span> <span class='kw'>if</span> <span class='id identifier rubyid_global'>global</span>
<span class='id identifier rubyid_snmp'>snmp</span>
<span class='kw'>end</span></pre>
</td>
</tr>
</table>
</div>
<div class="method_details ">
<h3 class="signature " id="disconnect_snmp-instance_method">
#<strong>disconnect_snmp</strong> &#x21d2; <tt>Object</tt>
</h3><table class="source_code">
<tr>
<td>
<pre class="lines">
60
61
62
63</pre>
</td>
<td>
<pre class="code"><span class="info file"># File 'lib/msf/core/exploit/remote/snmp_client.rb', line 60</span>
<span class='kw'>def</span> <span class='id identifier rubyid_disconnect_snmp'>disconnect_snmp</span>
<span class='ivar'>@snmp</span><span class='period'>.</span><span class='id identifier rubyid_close'>close</span> <span class='kw'>if</span> <span class='ivar'>@snmp</span>
<span class='ivar'>@snmp</span> <span class='op'>=</span> <span class='kw'>nil</span>
<span class='kw'>end</span></pre>
</td>
</tr>
</table>
</div>
<div class="method_details ">
<h3 class="signature " id="initialize-instance_method">
#<strong>initialize</strong>(info = {}) &#x21d2; <tt>Object</tt>
</h3><div class="docstring">
<div class="discussion">
<p>Creates an instance of a SNMP exploit module.</p>
</div>
</div>
<div class="tags">
</div><table class="source_code">
<tr>
<td>
<pre class="lines">
20
21
22
23
24
25
26
27
28
29
30
31
32
33</pre>
</td>
<td>
<pre class="code"><span class="info file"># File 'lib/msf/core/exploit/remote/snmp_client.rb', line 20</span>
<span class='kw'>def</span> <span class='id identifier rubyid_initialize'>initialize</span><span class='lparen'>(</span><span class='id identifier rubyid_info'>info</span> <span class='op'>=</span> <span class='lbrace'>{</span><span class='rbrace'>}</span><span class='rparen'>)</span>
<span class='kw'>super</span>
<span class='comment'># Register the options that all SNMP exploits may make use of.
</span> <span class='id identifier rubyid_register_options'>register_options</span><span class='lparen'>(</span>
<span class='lbracket'>[</span>
<span class='const'><span class='object_link'><a href="../../Opt.html" title="Msf::Opt (module)">Opt</a></span></span><span class='op'>::</span><span class='const'><span class='object_link'><a href="../../Opt.html#RHOST-constant" title="Msf::Opt::RHOST (constant)">RHOST</a></span></span><span class='comma'>,</span>
<span class='const'><span class='object_link'><a href="../../Opt.html" title="Msf::Opt (module)">Opt</a></span></span><span class='op'>::</span><span class='const'><span class='object_link'><a href="../../Opt.html#RPORT-constant" title="Msf::Opt::RPORT (constant)">RPORT</a></span></span><span class='lparen'>(</span><span class='int'>161</span><span class='rparen'>)</span><span class='comma'>,</span>
<span class='const'><span class='object_link'><a href="../../OptString.html" title="Msf::OptString (class)">OptString</a></span></span><span class='period'>.</span><span class='id identifier rubyid_new'><span class='object_link'><a href="../../OptString.html#initialize-instance_method" title="Msf::OptString#initialize (method)">new</a></span></span><span class='lparen'>(</span><span class='tstring'><span class='tstring_beg'>&#39;</span><span class='tstring_content'>COMMUNITY</span><span class='tstring_end'>&#39;</span></span><span class='comma'>,</span> <span class='lbracket'>[</span> <span class='kw'>true</span><span class='comma'>,</span> <span class='tstring'><span class='tstring_beg'>&#39;</span><span class='tstring_content'>SNMP Community String</span><span class='tstring_end'>&#39;</span></span><span class='comma'>,</span> <span class='tstring'><span class='tstring_beg'>&#39;</span><span class='tstring_content'>public</span><span class='tstring_end'>&#39;</span></span> <span class='rbracket'>]</span><span class='rparen'>)</span><span class='comma'>,</span>
<span class='const'><span class='object_link'><a href="../../OptString.html" title="Msf::OptString (class)">OptString</a></span></span><span class='period'>.</span><span class='id identifier rubyid_new'><span class='object_link'><a href="../../OptString.html#initialize-instance_method" title="Msf::OptString#initialize (method)">new</a></span></span><span class='lparen'>(</span><span class='tstring'><span class='tstring_beg'>&#39;</span><span class='tstring_content'>VERSION</span><span class='tstring_end'>&#39;</span></span><span class='comma'>,</span> <span class='lbracket'>[</span> <span class='kw'>true</span><span class='comma'>,</span> <span class='tstring'><span class='tstring_beg'>&#39;</span><span class='tstring_content'>SNMP Version &lt;1/2c&gt;</span><span class='tstring_end'>&#39;</span></span><span class='comma'>,</span> <span class='tstring'><span class='tstring_beg'>&#39;</span><span class='tstring_content'>1</span><span class='tstring_end'>&#39;</span></span> <span class='rbracket'>]</span><span class='rparen'>)</span><span class='comma'>,</span>
<span class='const'><span class='object_link'><a href="../../OptInt.html" title="Msf::OptInt (class)">OptInt</a></span></span><span class='period'>.</span><span class='id identifier rubyid_new'><span class='object_link'><a href="../../OptBase.html#initialize-instance_method" title="Msf::OptBase#initialize (method)">new</a></span></span><span class='lparen'>(</span><span class='tstring'><span class='tstring_beg'>&#39;</span><span class='tstring_content'>TIMEOUT</span><span class='tstring_end'>&#39;</span></span><span class='comma'>,</span> <span class='lbracket'>[</span> <span class='kw'>true</span><span class='comma'>,</span> <span class='tstring'><span class='tstring_beg'>&#39;</span><span class='tstring_content'>SNMP Timeout</span><span class='tstring_end'>&#39;</span></span><span class='comma'>,</span> <span class='int'>1</span> <span class='rbracket'>]</span><span class='rparen'>)</span><span class='comma'>,</span>
<span class='const'><span class='object_link'><a href="../../OptInt.html" title="Msf::OptInt (class)">OptInt</a></span></span><span class='period'>.</span><span class='id identifier rubyid_new'><span class='object_link'><a href="../../OptBase.html#initialize-instance_method" title="Msf::OptBase#initialize (method)">new</a></span></span><span class='lparen'>(</span><span class='tstring'><span class='tstring_beg'>&#39;</span><span class='tstring_content'>RETRIES</span><span class='tstring_end'>&#39;</span></span><span class='comma'>,</span> <span class='lbracket'>[</span> <span class='kw'>true</span><span class='comma'>,</span> <span class='tstring'><span class='tstring_beg'>&#39;</span><span class='tstring_content'>SNMP Retries</span><span class='tstring_end'>&#39;</span></span><span class='comma'>,</span> <span class='int'>1</span> <span class='rbracket'>]</span><span class='rparen'>)</span>
<span class='rbracket'>]</span><span class='comma'>,</span> <span class='const'><span class='object_link'><a href="../../../Msf.html" title="Msf (module)">Msf</a></span></span><span class='op'>::</span><span class='const'><span class='object_link'><a href="../../Exploit.html" title="Msf::Exploit (class)">Exploit</a></span></span><span class='op'>::</span><span class='const'><span class='object_link'><a href="../Remote.html" title="Msf::Exploit::Remote (class)">Remote</a></span></span><span class='op'>::</span><span class='const'><span class='object_link'><a href="" title="Msf::Exploit::Remote::SNMPClient (module)">SNMPClient</a></span></span><span class='rparen'>)</span>
<span class='kw'>end</span></pre>
</td>
</tr>
</table>
</div>
<div class="method_details ">
<h3 class="signature " id="retries-instance_method">
#<strong>retries</strong> &#x21d2; <tt>Object</tt>
</h3><table class="source_code">
<tr>
<td>
<pre class="lines">
77
78
79</pre>
</td>
<td>
<pre class="code"><span class="info file"># File 'lib/msf/core/exploit/remote/snmp_client.rb', line 77</span>
<span class='kw'>def</span> <span class='id identifier rubyid_retries'>retries</span>
<span class='id identifier rubyid_datastore'>datastore</span><span class='lbracket'>[</span><span class='tstring'><span class='tstring_beg'>&#39;</span><span class='tstring_content'>RETRIES</span><span class='tstring_end'>&#39;</span></span><span class='rbracket'>]</span> <span class='op'>||</span> <span class='int'>1</span>
<span class='kw'>end</span></pre>
</td>
</tr>
</table>
</div>
<div class="method_details ">
<h3 class="signature " id="timeout-instance_method">
#<strong>timeout</strong> &#x21d2; <tt>Object</tt>
</h3><table class="source_code">
<tr>
<td>
<pre class="lines">
73
74
75</pre>
</td>
<td>
<pre class="code"><span class="info file"># File 'lib/msf/core/exploit/remote/snmp_client.rb', line 73</span>
<span class='kw'>def</span> <span class='id identifier rubyid_timeout'>timeout</span>
<span class='id identifier rubyid_datastore'>datastore</span><span class='lbracket'>[</span><span class='tstring'><span class='tstring_beg'>&#39;</span><span class='tstring_content'>TIMEOUT</span><span class='tstring_end'>&#39;</span></span><span class='rbracket'>]</span> <span class='op'>||</span> <span class='int'>1</span>
<span class='kw'>end</span></pre>
</td>
</tr>
</table>
</div>
</div>
</div>
<div id="footer">
Generated on Fri May 8 17:02:01 2026 by
<a href="https://yardoc.org" title="Yay! A Ruby Documentation Tool" target="_parent">yard</a>
0.9.37 (ruby-3.1.5).
</div>
</div>
</body>
</html>
Reference in New Issue View Git Blame Copy Permalink