xenadmin/XenAdmin/Plugins/Placeholders.cs
Konstantina Chremmou d7b519a53c Updated copyright notice on files.
Signed-off-by: Konstantina Chremmou <Konstantina.Chremmou@cloud.com>
2023-01-30 16:24:16 +00:00

214 lines
10 KiB
C#

/* Copyright (c) Cloud Software Group, Inc.
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using System;
using System.Collections.Generic;
using System.Text.RegularExpressions;
using XenCenterLib;
using XenAdmin.XenSearch;
using XenAPI;
using System.Net.Sockets;
namespace XenAdmin.Plugins
{
/// <summary>
/// A plugin can specify various URLs, file paths, or command arguments, any of which
/// may contain placeholders such as {$session_id} or {$ip_address}. These are
/// replaced at time of use with the appropriate value.
///
/// Most values come from the parameters on the (first) selected object, but
/// {$session_id} is handled specially, and is replaced with the OpaqueRef of a
/// logged-in session.
/// </summary>
internal class Placeholders
{
private static readonly log4net.ILog log = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
private static Regex PlaceholderRegex = new Regex(@"{\$([\w:]+)}");
private const string PlaceholderFormat = @"{{${0}}}";
private const string NULL_PLACEHOLDER_KEY = "null";
private const string MULTI_TARGET_PLACEHOLDER_KEY = "multi_target";
/// <summary>
/// Gets the replacement for the specified placeholder for the specified object.
/// </summary>
/// <param name="placeholder">The placeholder to be replaced.</param>
/// <param name="objs">The objects that the placeholder replacements are for.</param>
/// <param name="match">A predicate indicating whether the specified placeholder should be replaced.</param>
/// <returns>The replacement for the specified placeholder.</returns>
private static string GetPlaceholderReplacement(string placeholder, IList<IXenObject> objs, Predicate<string> match)
{
if (match(placeholder))
{
if (objs == null || objs.Count == 0)
return NULL_PLACEHOLDER_KEY;
if (objs.Count > 1)
return MULTI_TARGET_PLACEHOLDER_KEY;
if (placeholder == "session_id")
{
if (objs[0].Connection == null || objs[0].Connection.Session == null)
{
return NULL_PLACEHOLDER_KEY;
}
return objs[0].Connection.Session.opaque_ref;
}
else
{
// otherwise update url with the latest info
PropertyNames property = (PropertyNames)Enum.Parse(typeof(PropertyNames), placeholder);
object val = PropertyAccessors.Get(property)(objs[0]);
return val != null ? val.ToString() : NULL_PLACEHOLDER_KEY;
}
}
return null;
}
/// <summary>
/// Replaces all placeholders (e.g. {$ip_address}, {$session_id} in the specified text for the specified object array.
/// Note that if there is more than one object in the array current behaviour is to sub in MULTI_TARGET_PLACEHOLDER_KEY for all situations
/// </summary>
/// <param name="text">The text that contains the placeholders to be replaced.</param>
/// <param name="objs">The objects that the placeholder replacements are for. Can be null.</param>
/// <param name="match">A predicate indicating whether the specified placeholder should be replaced.</param>
/// <returns>The processed text.</returns>
private static string Substitute(string text, IList<IXenObject> objs, Predicate<string> match)
{
return PlaceholderRegex.Replace(text, m =>
{
try
{
return GetPlaceholderReplacement(m.Groups[1].Value, objs, match) ?? m.Value;
}
catch (Exception e)
{
// Leave the placeholder in; nothing we can do.
log.Warn("Bad placeholder", e);
return m.Value;
}
});
}
/// <summary>
/// Replaces all placeholders (e.g. {$ip_address}, {$session_id} in the specified text for the specified obj.
/// </summary>
/// <param name="text">The text that contains the placeholders to be replaced.</param>
/// <param name="obj">The object that the placeholder replacements are for. Can be null.</param>
/// <param name="match">A predicate indicating whether the specified placeholder should be replaced.</param>
/// <returns>The processed text.</returns>
private static string Substitute(string text, IXenObject obj, Predicate<string> match)
{
return Substitute(text, obj == null ? null : new List<IXenObject> { obj }, match);
}
/// <summary>
/// Replaces all placeholders (e.g. {$ip_address}, {$session_id} in the specified text for the specified object array.
/// Note that if there is more than one object in the array current behaviour is to sub in MULTI_TARGET_PLACEHOLDER_KEY for all situations
/// </summary>
/// <param name="text">The text that contains the placeholders to be replaced.</param>
/// <param name="objs">The objects that the placeholder replacements are for. Can be null.</param>
/// <returns>The processed text.</returns>
public static string Substitute(string text, IList<IXenObject> objs)
{
return Substitute(text, objs, s => true);
}
/// <summary>
/// Replaces all placeholders (e.g. {$ip_address}, {$session_id} in the specified text for the specified obj.
/// </summary>
/// <param name="text">The text that contains the placeholders to be replaced.</param>
/// <param name="obj">The object that the placeholder replacements are for. Can be null.</param>
/// <returns>The processed text.</returns>
public static string Substitute(string text, IXenObject obj)
{
return Substitute(text, obj, s => true);
}
/// <summary>
/// Replaces all placeholders (e.g. {$ip_address}, {$session_id} in the specified text for the specified obj.
/// Since ip_address can take several values over different Networks, this method returns a list of Uri for
/// each of the different IP addresses.
/// </summary>
/// <param name="uri">The text that contains the placeholders to be replaced.</param>
/// <param name="obj">The object that the placeholder replacements are for.</param>
/// <returns>A List of Uris.</returns>
public static List<Uri> SubstituteUri(string uri, IXenObject obj)
{
Util.ThrowIfParameterNull(uri, "uri");
string ipAddressName = Enum.GetName(typeof(PropertyNames), PropertyNames.ip_address);
try
{
if (!uri.Contains(string.Format(PlaceholderFormat, ipAddressName)))
return new List<Uri> { new Uri(Substitute(uri, obj)) };
var ips = (List<ComparableAddress>)PropertyAccessors.Get(PropertyNames.ip_address)(obj);
if (ips == null || ips.Count == 0)
{
log.DebugFormat("Object {0} (opaque_ref {1}) has no IPs.", obj.Name(), obj.opaque_ref);
return new List<Uri> { new Uri("about:blank") };
}
string u = Substitute(uri, obj, s => s != ipAddressName);
return ips.ConvertAll(ip =>
{
var ipstring = ip.AddressIP != null && ip.AddressIP.AddressFamily == AddressFamily.InterNetworkV6
? string.Format("[{0}]", ip)
: ip.ToString();
return new Uri(u.Replace(string.Format(PlaceholderFormat, ipAddressName), ipstring));
});
}
catch (UriFormatException ex)
{
log.Warn("Failed to parse url.", ex);
return new List<Uri> { new Uri("about:blank") };
}
}
/// <summary>
/// Returns a value indicating whether the specified object can supply values for all placeholders
/// in the specified uri.
/// </summary>
/// <param name="uri">The uri string with placeholders to be read.</param>
/// <param name="obj">The IXenObject to be used for the placeholder substitution.</param>
/// <returns>A value indicating whether all place-holders could be replaced for this uri.</returns>
public static bool UriValid(string uri, IXenObject obj)
{
return SubstituteUri(uri, obj).TrueForAll(u => u.AbsoluteUri != "about:blank");
}
}
}