1 /*
2  * InspIRCd -- Internet Relay Chat Daemon
3  *
4  *   Copyright (C) 2019 linuxdaemon <linuxdaemon.irc@gmail.com>
5  *   Copyright (C) 2014, 2017-2021 Sadie Powell <sadie@witchery.services>
6  *   Copyright (C) 2014 Daniel Vassdal <shutter@canternet.org>
7  *   Copyright (C) 2012-2016 Attila Molnar <attilamolnar@hush.com>
8  *   Copyright (C) 2012 Robby <robby@chatbelgie.be>
9  *   Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
10  *   Copyright (C) 2008, 2010 Craig Edwards <brain@inspircd.org>
11  *   Copyright (C) 2008 Thomas Stagner <aquanight@inspircd.org>
12  *   Copyright (C) 2008 Robin Burchell <robin+git@viroteck.net>
13  *
14  * This file is part of InspIRCd.  InspIRCd is free software: you can
15  * redistribute it and/or modify it under the terms of the GNU General Public
16  * License as published by the Free Software Foundation, version 2.
17  *
18  * This program is distributed in the hope that it will be useful, but WITHOUT
19  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
20  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
21  * details.
22  *
23  * You should have received a copy of the GNU General Public License
24  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
25  */
26 
27 
28 #include "inspircd.h"
29 
30 #include "treeserver.h"
31 #include "utils.h"
32 #include "link.h"
33 #include "main.h"
34 
35 struct CompatMod
36 {
37 	const char* name;
38 	ModuleFlags listflag;
39 };
40 
41 static CompatMod compatmods[] =
42 {
43 	{ "m_watch.so", VF_OPTCOMMON }
44 };
45 
MyModules(int filter)46 std::string TreeSocket::MyModules(int filter)
47 {
48 	const ModuleManager::ModuleMap& modlist = ServerInstance->Modules->GetModules();
49 
50 	std::string capabilities;
51 	for (ModuleManager::ModuleMap::const_iterator i = modlist.begin(); i != modlist.end(); ++i)
52 	{
53 		Module* const mod = i->second;
54 		// 3.0 advertises its settings for the benefit of services
55 		// 2.0 would bork on this
56 		if (proto_version < PROTO_INSPIRCD_30 && mod->ModuleSourceFile == "m_kicknorejoin.so")
57 			continue;
58 
59 		bool do_compat_include = false;
60 		if (proto_version < PROTO_INSPIRCD_30)
61 		{
62 			for (size_t j = 0; j < sizeof(compatmods)/sizeof(compatmods[0]); j++)
63 			{
64 				if ((compatmods[j].listflag & filter) && (mod->ModuleSourceFile == compatmods[j].name))
65 				{
66 					do_compat_include = true;
67 					break;
68 				}
69 			}
70 		}
71 
72 		Version v = mod->GetVersion();
73 		if ((!do_compat_include) && (!(v.Flags & filter)))
74 			continue;
75 
76 		capabilities.push_back(' ');
77 		capabilities.append(i->first);
78 		if (!v.link_data.empty())
79 		{
80 			capabilities.push_back('=');
81 			capabilities.append(v.link_data);
82 		}
83 	}
84 
85 	// If we are linked in a 2.0 server and have an ascii casemapping
86 	// advertise it as m_ascii.so from inspircd-extras
87 	if ((filter & VF_COMMON) && ServerInstance->Config->CaseMapping == "ascii" && proto_version == PROTO_INSPIRCD_20)
88 		capabilities.append(" m_ascii.so");
89 
90 	if (capabilities.empty())
91 		return capabilities;
92 
93 	return capabilities.substr(1);
94 }
95 
BuildModeList(ModeType mtype)96 std::string TreeSocket::BuildModeList(ModeType mtype)
97 {
98 	std::vector<std::string> modes;
99 	const ModeParser::ModeHandlerMap& mhs = ServerInstance->Modes.GetModes(mtype);
100 	for (ModeParser::ModeHandlerMap::const_iterator i = mhs.begin(); i != mhs.end(); ++i)
101 	{
102 		const ModeHandler* const mh = i->second;
103 		const PrefixMode* const pm = mh->IsPrefixMode();
104 		std::string mdesc;
105 		if (proto_version >= PROTO_INSPIRCD_30)
106 		{
107 			if (pm)
108 				mdesc.append("prefix:").append(ConvToStr(pm->GetPrefixRank())).push_back(':');
109 			else if (mh->IsListMode())
110 				mdesc.append("list:");
111 			else if (mh->NeedsParam(true))
112 				mdesc.append(mh->NeedsParam(false) ? "param:" : "param-set:");
113 			else
114 				mdesc.append("simple:");
115 		}
116 		mdesc.append(mh->name);
117 		mdesc.push_back('=');
118 		if (pm)
119 		{
120 			if (pm->GetPrefix())
121 				mdesc.push_back(pm->GetPrefix());
122 		}
123 		mdesc.push_back(mh->GetModeChar());
124 		modes.push_back(mdesc);
125 	}
126 	std::sort(modes.begin(), modes.end());
127 	return stdalgo::string::join(modes);
128 }
129 
SendCapabilities(int phase)130 void TreeSocket::SendCapabilities(int phase)
131 {
132 	if (capab->capab_phase >= phase)
133 		return;
134 
135 	if (capab->capab_phase < 1 && phase >= 1)
136 		WriteLine("CAPAB START " + ConvToStr(PROTO_NEWEST));
137 
138 	capab->capab_phase = phase;
139 	if (phase < 2)
140 		return;
141 
142 	const char sep = ' ';
143 	irc::sepstream modulelist(MyModules(VF_COMMON), sep);
144 	irc::sepstream optmodulelist(MyModules(VF_OPTCOMMON), sep);
145 	/* Send module names, split at 509 length */
146 	std::string item;
147 	std::string line = "CAPAB MODULES :";
148 	while (modulelist.GetToken(item))
149 	{
150 		if (line.length() + item.length() + 1 > 509)
151 		{
152 			this->WriteLine(line);
153 			line = "CAPAB MODULES :";
154 		}
155 
156 		if (line != "CAPAB MODULES :")
157 			line.push_back(sep);
158 
159 		line.append(item);
160 	}
161 	if (line != "CAPAB MODULES :")
162 		this->WriteLine(line);
163 
164 	line = "CAPAB MODSUPPORT :";
165 	while (optmodulelist.GetToken(item))
166 	{
167 		if (line.length() + item.length() + 1 > 509)
168 		{
169 			this->WriteLine(line);
170 			line = "CAPAB MODSUPPORT :";
171 		}
172 
173 		if (line != "CAPAB MODSUPPORT :")
174 			line.push_back(sep);
175 
176 		line.append(item);
177 	}
178 	if (line != "CAPAB MODSUPPORT :")
179 		this->WriteLine(line);
180 
181 	WriteLine("CAPAB CHANMODES :" + BuildModeList(MODETYPE_CHANNEL));
182 	WriteLine("CAPAB USERMODES :" + BuildModeList(MODETYPE_USER));
183 
184 	std::string extra;
185 	/* Do we have sha256 available? If so, we send a challenge */
186 	if (ServerInstance->Modules->FindService(SERVICE_DATA, "hash/sha256"))
187 	{
188 		SetOurChallenge(ServerInstance->GenRandomStr(20));
189 		extra = " CHALLENGE=" + this->GetOurChallenge();
190 	}
191 
192 	// 2.0 needs these keys.
193 	if (proto_version == PROTO_INSPIRCD_20)
194 	{
195 		extra.append(" PROTOCOL="+ConvToStr(proto_version))
196 			.append(" MAXGECOS="+ConvToStr(ServerInstance->Config->Limits.MaxReal))
197 			.append(" CHANMODES="+ServerInstance->Modes->GiveModeList(MODETYPE_CHANNEL))
198 			.append(" USERMODES="+ServerInstance->Modes->GiveModeList(MODETYPE_USER))
199 			.append(" PREFIX="+ ServerInstance->Modes->BuildPrefixes());
200 	}
201 
202 	// HACK: Allow services to know what extbans exist. This will be
203 	// replaced by CAPAB EXTBANS in the next protocol version.
204 	std::map<std::string, std::string> tokens;
205 	FOREACH_MOD(On005Numeric, (tokens));
206 	std::map<std::string, std::string>::const_iterator eiter = tokens.find("EXTBAN");
207 	if (eiter != tokens.end())
208 		extra.append(" EXTBANS=" + eiter->second);
209 
210 	this->WriteLine("CAPAB CAPABILITIES " /* Preprocessor does this one. */
211 			":NICKMAX="+ConvToStr(ServerInstance->Config->Limits.NickMax)+
212 			" CHANMAX="+ConvToStr(ServerInstance->Config->Limits.ChanMax)+
213 			" MAXMODES="+ConvToStr(ServerInstance->Config->Limits.MaxModes)+
214 			" IDENTMAX="+ConvToStr(ServerInstance->Config->Limits.IdentMax)+
215 			" MAXQUIT="+ConvToStr(ServerInstance->Config->Limits.MaxQuit)+
216 			" MAXTOPIC="+ConvToStr(ServerInstance->Config->Limits.MaxTopic)+
217 			" MAXKICK="+ConvToStr(ServerInstance->Config->Limits.MaxKick)+
218 			" MAXREAL="+ConvToStr(ServerInstance->Config->Limits.MaxReal)+
219 			" MAXAWAY="+ConvToStr(ServerInstance->Config->Limits.MaxAway)+
220 			" MAXHOST="+ConvToStr(ServerInstance->Config->Limits.MaxHost)+
221 			" MAXLINE="+ConvToStr(ServerInstance->Config->Limits.MaxLine)+
222 			extra+
223 			" CASEMAPPING="+ServerInstance->Config->CaseMapping+
224 			// XXX: Advertise the presence or absence of m_globops in CAPAB CAPABILITIES.
225 			// Services want to know about it, and since m_globops was not marked as VF_(OPT)COMMON
226 			// in 2.0, we advertise it here to not break linking to previous versions.
227 			// Protocol version 1201 (1.2) does not have this issue because we advertise m_globops
228 			// to 1201 protocol servers irrespectively of its module flags.
229 			(ServerInstance->Modules->Find("m_globops.so") != NULL ? " GLOBOPS=1" : " GLOBOPS=0")
230 			);
231 
232 	this->WriteLine("CAPAB END");
233 }
234 
235 /* Isolate and return the elements that are different between two comma separated lists */
ListDifference(const std::string & one,const std::string & two,char sep,std::string & mleft,std::string & mright)236 void TreeSocket::ListDifference(const std::string &one, const std::string &two, char sep,
237 		std::string& mleft, std::string& mright)
238 {
239 	std::set<std::string> values;
240 	irc::sepstream sepleft(one, sep);
241 	irc::sepstream sepright(two, sep);
242 	std::string item;
243 	while (sepleft.GetToken(item))
244 	{
245 		values.insert(item);
246 	}
247 	while (sepright.GetToken(item))
248 	{
249 		if (!values.erase(item))
250 		{
251 			mright.push_back(sep);
252 			mright.append(item);
253 		}
254 	}
255 	for(std::set<std::string>::iterator i = values.begin(); i != values.end(); ++i)
256 	{
257 		mleft.push_back(sep);
258 		mleft.append(*i);
259 	}
260 }
261 
Capab(const CommandBase::Params & params)262 bool TreeSocket::Capab(const CommandBase::Params& params)
263 {
264 	if (params.size() < 1)
265 	{
266 		this->SendError("Invalid number of parameters for CAPAB - Mismatched version");
267 		return false;
268 	}
269 	if (params[0] == "START")
270 	{
271 		capab->ModuleList.clear();
272 		capab->OptModuleList.clear();
273 		capab->CapKeys.clear();
274 		if (params.size() > 1)
275 			proto_version = ConvToNum<unsigned int>(params[1]);
276 
277 		if (proto_version < PROTO_OLDEST)
278 		{
279 			SendError("CAPAB negotiation failed: Server is using protocol version "
280 				+ (proto_version ? ConvToStr(proto_version) : "1201 or older")
281 				+ " which is too old to link with this server (protocol versions "
282 				+ ConvToStr(PROTO_OLDEST) + " to " + ConvToStr(PROTO_NEWEST) + " are supported)");
283 			return false;
284 		}
285 
286 		// We don't support the 2.1 protocol.
287 		if (proto_version == PROTO_INSPIRCD_21_A0 || proto_version == PROTO_INSPIRCD_21_B2)
288 		{
289 			SendError("CAPAB negotiation failed: InspIRCd 2.1 beta is not supported");
290 			return false;
291 		}
292 
293 		SendCapabilities(2);
294 	}
295 	else if (params[0] == "END")
296 	{
297 		std::string reason;
298 		/* Compare ModuleList and check CapKeys */
299 		if ((this->capab->ModuleList != this->MyModules(VF_COMMON)) && (this->capab->ModuleList.length()))
300 		{
301 			std::string diffIneed, diffUneed;
302 			ListDifference(this->capab->ModuleList, this->MyModules(VF_COMMON), ' ', diffIneed, diffUneed);
303 			if (diffIneed.length() || diffUneed.length())
304 			{
305 				reason = "Modules incorrectly matched on these servers.";
306 				if (diffIneed.length())
307 					reason += " Not loaded here:" + diffIneed;
308 				if (diffUneed.length())
309 					reason += " Not loaded there:" + diffUneed;
310 				this->SendError("CAPAB negotiation failed: "+reason);
311 				return false;
312 			}
313 		}
314 
315 		if (this->capab->OptModuleList != this->MyModules(VF_OPTCOMMON) && this->capab->OptModuleList.length())
316 		{
317 			std::string diffIneed, diffUneed;
318 			ListDifference(this->capab->OptModuleList, this->MyModules(VF_OPTCOMMON), ' ', diffIneed, diffUneed);
319 			if (diffIneed.length() || diffUneed.length())
320 			{
321 				if (Utils->AllowOptCommon)
322 				{
323 					ServerInstance->SNO->WriteToSnoMask('l',
324 						"Optional module lists do not match, some commands may not work globally.%s%s%s%s",
325 						diffIneed.length() ? " Not loaded here:" : "", diffIneed.c_str(),
326 						diffUneed.length() ? " Not loaded there:" : "", diffUneed.c_str());
327 				}
328 				else
329 				{
330 					reason = "Optional modules incorrectly matched on these servers and <options:allowmismatch> is not enabled.";
331 					if (diffIneed.length())
332 						reason += " Not loaded here:" + diffIneed;
333 					if (diffUneed.length())
334 						reason += " Not loaded there:" + diffUneed;
335 					this->SendError("CAPAB negotiation failed: "+reason);
336 					return false;
337 				}
338 			}
339 		}
340 
341 		if (!capab->ChanModes.empty())
342 		{
343 			if (capab->ChanModes != BuildModeList(MODETYPE_CHANNEL))
344 			{
345 				std::string diffIneed, diffUneed;
346 				ListDifference(capab->ChanModes, BuildModeList(MODETYPE_CHANNEL), ' ', diffIneed, diffUneed);
347 				if (diffIneed.length() || diffUneed.length())
348 				{
349 					reason = "Channel modes not matched on these servers.";
350 					if (diffIneed.length())
351 						reason += " Not loaded here:" + diffIneed;
352 					if (diffUneed.length())
353 						reason += " Not loaded there:" + diffUneed;
354 				}
355 			}
356 		}
357 		else if (proto_version == PROTO_INSPIRCD_20)
358 		{
359 			if (this->capab->CapKeys.find("CHANMODES") != this->capab->CapKeys.end())
360 			{
361 				if (this->capab->CapKeys.find("CHANMODES")->second != ServerInstance->Modes->GiveModeList(MODETYPE_CHANNEL))
362 					reason = "One or more of the channel modes on the remote server are invalid on this server.";
363 			}
364 
365 			else if (this->capab->CapKeys.find("PREFIX") != this->capab->CapKeys.end())
366 			{
367 				if (this->capab->CapKeys.find("PREFIX")->second != ServerInstance->Modes->BuildPrefixes())
368 					reason = "One or more of the prefixes on the remote server are invalid on this server.";
369 			}
370 		}
371 
372 		if (!reason.empty())
373 		{
374 			this->SendError("CAPAB negotiation failed: " + reason);
375 			return false;
376 		}
377 
378 		if (!capab->UserModes.empty())
379 		{
380 			if (capab->UserModes != BuildModeList(MODETYPE_USER))
381 			{
382 				std::string diffIneed, diffUneed;
383 				ListDifference(capab->UserModes, BuildModeList(MODETYPE_USER), ' ', diffIneed, diffUneed);
384 				if (diffIneed.length() || diffUneed.length())
385 				{
386 					reason = "User modes not matched on these servers.";
387 					if (diffIneed.length())
388 						reason += " Not loaded here:" + diffIneed;
389 					if (diffUneed.length())
390 						reason += " Not loaded there:" + diffUneed;
391 				}
392 			}
393 		}
394 		else if (proto_version == PROTO_INSPIRCD_20 && this->capab->CapKeys.find("USERMODES") != this->capab->CapKeys.end())
395 		{
396 			if (this->capab->CapKeys.find("USERMODES")->second != ServerInstance->Modes->GiveModeList(MODETYPE_USER))
397 				reason = "One or more of the user modes on the remote server are invalid on this server.";
398 		}
399 
400 		if (!reason.empty())
401 		{
402 			this->SendError("CAPAB negotiation failed: " + reason);
403 			return false;
404 		}
405 
406 		if (this->capab->CapKeys.find("CASEMAPPING") != this->capab->CapKeys.end())
407 		{
408 			const std::string casemapping = this->capab->CapKeys.find("CASEMAPPING")->second;
409 			if (casemapping != ServerInstance->Config->CaseMapping)
410 			{
411 				reason = "The casemapping of the remote server differs to that of the local server."
412 					" Local casemapping: " + ServerInstance->Config->CaseMapping +
413 					" Remote casemapping: " + casemapping;
414 				this->SendError("CAPAB negotiation failed: " + reason);
415 				return false;
416 			}
417 		}
418 
419 		/* Challenge response, store their challenge for our password */
420 		std::map<std::string,std::string>::iterator n = this->capab->CapKeys.find("CHALLENGE");
421 		if ((n != this->capab->CapKeys.end()) && (ServerInstance->Modules->FindService(SERVICE_DATA, "hash/sha256")))
422 		{
423 			/* Challenge-response is on now */
424 			this->SetTheirChallenge(n->second);
425 			if (!this->GetTheirChallenge().empty() && (this->LinkState == CONNECTING))
426 			{
427 				this->SendCapabilities(2);
428 				this->WriteLine("SERVER "+ServerInstance->Config->ServerName+" "+this->MakePass(capab->link->SendPass, capab->theirchallenge)+" 0 "+ServerInstance->Config->GetSID()+" :"+ServerInstance->Config->ServerDesc);
429 			}
430 		}
431 		else
432 		{
433 			// They didn't specify a challenge or we don't have sha256, we use plaintext
434 			if (this->LinkState == CONNECTING)
435 			{
436 				this->SendCapabilities(2);
437 				this->WriteLine("SERVER "+ServerInstance->Config->ServerName+" "+capab->link->SendPass+" 0 "+ServerInstance->Config->GetSID()+" :"+ServerInstance->Config->ServerDesc);
438 			}
439 		}
440 	}
441 	else if ((params[0] == "MODULES") && (params.size() == 2))
442 	{
443 		if (!capab->ModuleList.length())
444 		{
445 			capab->ModuleList = params[1];
446 		}
447 		else
448 		{
449 			capab->ModuleList.push_back(' ');
450 			capab->ModuleList.append(params[1]);
451 		}
452 	}
453 	else if ((params[0] == "MODSUPPORT") && (params.size() == 2))
454 	{
455 		if (!capab->OptModuleList.length())
456 		{
457 			capab->OptModuleList = params[1];
458 		}
459 		else
460 		{
461 			capab->OptModuleList.push_back(' ');
462 			capab->OptModuleList.append(params[1]);
463 		}
464 	}
465 	else if ((params[0] == "CHANMODES") && (params.size() == 2))
466 	{
467 		capab->ChanModes = params[1];
468 	}
469 	else if ((params[0] == "USERMODES") && (params.size() == 2))
470 	{
471 		capab->UserModes = params[1];
472 	}
473 	else if ((params[0] == "CAPABILITIES") && (params.size() == 2))
474 	{
475 		irc::spacesepstream capabs(params[1]);
476 		std::string item;
477 		while (capabs.GetToken(item))
478 		{
479 			/* Process each key/value pair */
480 			std::string::size_type equals = item.find('=');
481 			if (equals != std::string::npos)
482 			{
483 				std::string var(item, 0, equals);
484 				std::string value(item, equals+1);
485 				capab->CapKeys[var] = value;
486 			}
487 		}
488 	}
489 	return true;
490 }
491