1 /*
2  * InspIRCd -- Internet Relay Chat Daemon
3  *
4  *   Copyright (C) 2019 linuxdaemon <linuxdaemon.irc@gmail.com>
5  *   Copyright (C) 2013-2014 Attila Molnar <attilamolnar@hush.com>
6  *   Copyright (C) 2013, 2017-2021 Sadie Powell <sadie@witchery.services>
7  *   Copyright (C) 2013 Daniel Vassdal <shutter@canternet.org>
8  *   Copyright (C) 2012 Robby <robby@chatbelgie.be>
9  *   Copyright (C) 2009-2011 Daniel De Graaf <danieldg@inspircd.org>
10  *   Copyright (C) 2009 Uli Schlachter <psychon@inspircd.org>
11  *   Copyright (C) 2008 Thomas Stagner <aquanight@inspircd.org>
12  *   Copyright (C) 2007 John Brooks <special@inspircd.org>
13  *   Copyright (C) 2007 Dennis Friis <peavey@inspircd.org>
14  *   Copyright (C) 2006 Craig Edwards <brain@inspircd.org>
15  *
16  * This file is part of InspIRCd.  InspIRCd is free software: you can
17  * redistribute it and/or modify it under the terms of the GNU General Public
18  * License as published by the Free Software Foundation, version 2.
19  *
20  * This program is distributed in the hope that it will be useful, but WITHOUT
21  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
22  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
23  * details.
24  *
25  * You should have received a copy of the GNU General Public License
26  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
27  */
28 
29 
30 #include "inspircd.h"
31 
BindPort(ConfigTag * tag,const irc::sockets::sockaddrs & sa,std::vector<ListenSocket * > & old_ports)32 bool InspIRCd::BindPort(ConfigTag* tag, const irc::sockets::sockaddrs& sa, std::vector<ListenSocket*>& old_ports)
33 {
34 	for (std::vector<ListenSocket*>::iterator n = old_ports.begin(); n != old_ports.end(); ++n)
35 	{
36 		if ((**n).bind_sa == sa)
37 		{
38 			// Replace tag, we know addr and port match, but other info (type, ssl) may not.
39 			ServerInstance->Logs->Log("SOCKET", LOG_DEFAULT, "Replacing listener on %s from old tag at %s with new tag from %s",
40 				sa.str().c_str(), (*n)->bind_tag->getTagLocation().c_str(), tag->getTagLocation().c_str());
41 			(*n)->bind_tag = tag;
42 			(*n)->ResetIOHookProvider();
43 
44 			old_ports.erase(n);
45 			return true;
46 		}
47 	}
48 
49 	ListenSocket* ll = new ListenSocket(tag, sa);
50 	if (!ll->HasFd())
51 	{
52 		ServerInstance->Logs->Log("SOCKET", LOG_DEFAULT, "Failed to listen on %s from tag at %s: %s",
53 			sa.str().c_str(), tag->getTagLocation().c_str(), strerror(errno));
54 		delete ll;
55 		return false;
56 	}
57 
58 	ServerInstance->Logs->Log("SOCKET", LOG_DEFAULT, "Added a listener on %s from tag at %s", sa.str().c_str(), tag->getTagLocation().c_str());
59 	ports.push_back(ll);
60 	return true;
61 }
62 
BindPorts(FailedPortList & failed_ports)63 size_t InspIRCd::BindPorts(FailedPortList& failed_ports)
64 {
65 	size_t bound = 0;
66 	std::vector<ListenSocket*> old_ports(ports.begin(), ports.end());
67 
68 	ConfigTagList tags = ServerInstance->Config->ConfTags("bind");
69 	for (ConfigIter i = tags.first; i != tags.second; ++i)
70 	{
71 		ConfigTag* tag = i->second;
72 
73 		// Are we creating a TCP/IP listener?
74 		const std::string address = tag->getString("address");
75 		const std::string portlist = tag->getString("port");
76 		if (!address.empty() || !portlist.empty())
77 		{
78 			// InspIRCd supports IPv4 and IPv6 natively; no 4in6 required.
79 			if (strncasecmp(address.c_str(), "::ffff:", 7) == 0)
80 				this->Logs->Log("SOCKET", LOG_DEFAULT, "Using 4in6 (::ffff:) isn't recommended. You should bind IPv4 addresses directly instead.");
81 
82 			// A TCP listener with no ports is not very useful.
83 			if (portlist.empty())
84 				this->Logs->Log("SOCKET", LOG_DEFAULT, "TCP listener on %s at %s has no ports specified!",
85 					address.empty() ? "*" : address.c_str(), tag->getTagLocation().c_str());
86 
87 			irc::portparser portrange(portlist, false);
88 			for (int port; (port = portrange.GetToken()); )
89 			{
90 				irc::sockets::sockaddrs bindspec;
91 				if (!irc::sockets::aptosa(address, port, bindspec))
92 					continue;
93 
94 				if (!BindPort(tag, bindspec, old_ports))
95 					failed_ports.push_back(FailedPort(errno, bindspec, tag));
96 				else
97 					bound++;
98 			}
99 			continue;
100 		}
101 
102 #ifndef _WIN32
103 		// Are we creating a UNIX listener?
104 		const std::string path = tag->getString("path");
105 		if (!path.empty())
106 		{
107 			// Expand the path relative to the config directory.
108 			const std::string fullpath = ServerInstance->Config->Paths.PrependRuntime(path);
109 
110 			// UNIX socket paths are length limited to less than PATH_MAX.
111 			irc::sockets::sockaddrs bindspec;
112 			if (fullpath.length() > std::min(ServerInstance->Config->Limits.MaxHost, sizeof(bindspec.un.sun_path) - 1))
113 			{
114 				this->Logs->Log("SOCKET", LOG_DEFAULT, "UNIX listener on %s at %s specified a path that is too long!",
115 					fullpath.c_str(), tag->getTagLocation().c_str());
116 				continue;
117 			}
118 
119 			// Check for characters which are problematic in the IRC message format.
120 			if (fullpath.find_first_of("\n\r\t!@: ") != std::string::npos)
121 			{
122 				this->Logs->Log("SOCKET", LOG_DEFAULT, "UNIX listener on %s at %s specified a path containing invalid characters!",
123 					fullpath.c_str(), tag->getTagLocation().c_str());
124 				continue;
125 			}
126 
127 			irc::sockets::untosa(fullpath, bindspec);
128 			if (!BindPort(tag, bindspec, old_ports))
129 				failed_ports.push_back(FailedPort(errno, bindspec, tag));
130 			else
131 				bound++;
132 		}
133 #endif
134 	}
135 
136 	std::vector<ListenSocket*>::iterator n = ports.begin();
137 	for (std::vector<ListenSocket*>::iterator o = old_ports.begin(); o != old_ports.end(); ++o)
138 	{
139 		while (n != ports.end() && *n != *o)
140 			n++;
141 		if (n == ports.end())
142 		{
143 			this->Logs->Log("SOCKET", LOG_DEFAULT, "Port bindings slipped out of vector, aborting close!");
144 			break;
145 		}
146 
147 		this->Logs->Log("SOCKET", LOG_DEFAULT, "Port binding %s was removed from the config file, closing.",
148 			(**n).bind_sa.str().c_str());
149 		delete *n;
150 
151 		// this keeps the iterator valid, pointing to the next element
152 		n = ports.erase(n);
153 	}
154 
155 	return bound;
156 }
157 
aptosa(const std::string & addr,int port,irc::sockets::sockaddrs & sa)158 bool irc::sockets::aptosa(const std::string& addr, int port, irc::sockets::sockaddrs& sa)
159 {
160 	memset(&sa, 0, sizeof(sa));
161 	if (addr.empty() || addr.c_str()[0] == '*')
162 	{
163 		if (ServerInstance->Config->WildcardIPv6)
164 		{
165 			sa.in6.sin6_family = AF_INET6;
166 			sa.in6.sin6_port = htons(port);
167 		}
168 		else
169 		{
170 			sa.in4.sin_family = AF_INET;
171 			sa.in4.sin_port = htons(port);
172 		}
173 		return true;
174 	}
175 	else if (inet_pton(AF_INET, addr.c_str(), &sa.in4.sin_addr) > 0)
176 	{
177 		sa.in4.sin_family = AF_INET;
178 		sa.in4.sin_port = htons(port);
179 		return true;
180 	}
181 	else if (inet_pton(AF_INET6, addr.c_str(), &sa.in6.sin6_addr) > 0)
182 	{
183 		sa.in6.sin6_family = AF_INET6;
184 		sa.in6.sin6_port = htons(port);
185 		return true;
186 	}
187 	return false;
188 }
189 
untosa(const std::string & path,irc::sockets::sockaddrs & sa)190 bool irc::sockets::untosa(const std::string& path, irc::sockets::sockaddrs& sa)
191 {
192 	memset(&sa, 0, sizeof(sa));
193 	if (path.length() >= sizeof(sa.un.sun_path))
194 		return false;
195 
196 	sa.un.sun_family = AF_UNIX;
197 	memcpy(&sa.un.sun_path, path.c_str(), path.length() + 1);
198 	return true;
199 }
200 
isunix(const std::string & file)201 bool irc::sockets::isunix(const std::string& file)
202 {
203 #ifndef _WIN32
204 	struct stat sb;
205 	if (stat(file.c_str(), &sb) == 0 && S_ISSOCK(sb.st_mode))
206 		return true;
207 #endif
208 	return false;
209 }
210 
211 
family() const212 int irc::sockets::sockaddrs::family() const
213 {
214 	return sa.sa_family;
215 }
216 
port() const217 int irc::sockets::sockaddrs::port() const
218 {
219 	switch (family())
220 	{
221 		case AF_INET:
222 			return ntohs(in4.sin_port);
223 
224 		case AF_INET6:
225 			return ntohs(in6.sin6_port);
226 
227 		case AF_UNIX:
228 			return 0;
229 	}
230 
231 	// If we have reached this point then we have encountered a bug.
232 	ServerInstance->Logs->Log("SOCKET", LOG_DEBUG, "BUG: irc::sockets::sockaddrs::port(): socket type %d is unknown!", family());
233 	return 0;
234 }
235 
addr() const236 std::string irc::sockets::sockaddrs::addr() const
237 {
238 	switch (family())
239 	{
240 		case AF_INET:
241 			char ip4addr[INET_ADDRSTRLEN];
242 			if (!inet_ntop(AF_INET, (void*)&in4.sin_addr, ip4addr, sizeof(ip4addr)))
243 				return "0.0.0.0";
244 			return ip4addr;
245 
246 		case AF_INET6:
247 			char ip6addr[INET6_ADDRSTRLEN];
248 			if (!inet_ntop(AF_INET6, (void*)&in6.sin6_addr, ip6addr, sizeof(ip6addr)))
249 				return "0:0:0:0:0:0:0:0";
250 			return ip6addr;
251 
252 		case AF_UNIX:
253 			return un.sun_path;
254 	}
255 
256 	// If we have reached this point then we have encountered a bug.
257 	ServerInstance->Logs->Log("SOCKET", LOG_DEBUG, "BUG: irc::sockets::sockaddrs::addr(): socket type %d is unknown!", family());
258 	return "<unknown>";
259 }
260 
str() const261 std::string irc::sockets::sockaddrs::str() const
262 {
263 	switch (family())
264 	{
265 		case AF_INET:
266 			char ip4addr[INET_ADDRSTRLEN];
267 			if (!inet_ntop(AF_INET, (void*)&in4.sin_addr, ip4addr, sizeof(ip4addr)))
268 				strcpy(ip4addr, "0.0.0.0");
269 			return InspIRCd::Format("%s:%u", ip4addr, ntohs(in4.sin_port));
270 
271 		case AF_INET6:
272 			char ip6addr[INET6_ADDRSTRLEN];
273 			if (!inet_ntop(AF_INET6, (void*)&in6.sin6_addr, ip6addr, sizeof(ip6addr)))
274 				strcpy(ip6addr, "0:0:0:0:0:0:0:0");
275 			return InspIRCd::Format("[%s]:%u", ip6addr, ntohs(in6.sin6_port));
276 
277 		case AF_UNIX:
278 			return un.sun_path;
279 	}
280 
281 	// If we have reached this point then we have encountered a bug.
282 	ServerInstance->Logs->Log("SOCKET", LOG_DEBUG, "BUG: irc::sockets::sockaddrs::str(): socket type %d is unknown!", family());
283 	return "<unknown>";
284 }
285 
sa_size() const286 socklen_t irc::sockets::sockaddrs::sa_size() const
287 {
288 	switch (family())
289 	{
290 		case AF_INET:
291 			return sizeof(in4);
292 
293 		case AF_INET6:
294 			return sizeof(in6);
295 
296 		case AF_UNIX:
297 			return sizeof(un);
298 	}
299 
300 	// If we have reached this point then we have encountered a bug.
301 	ServerInstance->Logs->Log("SOCKET", LOG_DEBUG, "BUG: irc::sockets::sockaddrs::sa_size(): socket type %d is unknown!", family());
302 	return 0;
303 }
304 
operator ==(const irc::sockets::sockaddrs & other) const305 bool irc::sockets::sockaddrs::operator==(const irc::sockets::sockaddrs& other) const
306 {
307 	if (family() != other.family())
308 		return false;
309 
310 	switch (family())
311 	{
312 		case AF_INET:
313 			return (in4.sin_port == other.in4.sin_port) && (in4.sin_addr.s_addr == other.in4.sin_addr.s_addr);
314 
315 		case AF_INET6:
316 			return (in6.sin6_port == other.in6.sin6_port) && !memcmp(in6.sin6_addr.s6_addr, other.in6.sin6_addr.s6_addr, 16);
317 
318 		case AF_UNIX:
319 			return !strcmp(un.sun_path, other.un.sun_path);
320 	}
321 
322 	// If we have reached this point then we have encountered a bug.
323 	ServerInstance->Logs->Log("SOCKET", LOG_DEBUG, "BUG: irc::sockets::sockaddrs::operator==(): socket type %d is unknown!", family());
324 	return !memcmp(this, &other, sizeof(*this));
325 }
326 
sa2cidr(irc::sockets::cidr_mask & cidr,const irc::sockets::sockaddrs & sa,unsigned char range)327 static void sa2cidr(irc::sockets::cidr_mask& cidr, const irc::sockets::sockaddrs& sa, unsigned char range)
328 {
329 	const unsigned char* base;
330 	unsigned char target_byte;
331 
332 	memset(cidr.bits, 0, sizeof(cidr.bits));
333 
334 	cidr.type = sa.family();
335 	switch (cidr.type)
336 	{
337 		case AF_UNIX:
338 			// XXX: UNIX sockets don't support CIDR. This fix is non-ideal but I can't
339 			// really think of another way to handle it.
340 			cidr.length = 0;
341 			return;
342 
343 		case AF_INET:
344 			cidr.length = range > 32 ? 32 : range;
345 			target_byte = sizeof(sa.in4.sin_addr);
346 			base = (unsigned char*)&sa.in4.sin_addr;
347 			break;
348 
349 		case AF_INET6:
350 			cidr.length = range > 128 ? 128 : range;
351 			target_byte = sizeof(sa.in6.sin6_addr);
352 			base = (unsigned char*)&sa.in6.sin6_addr;
353 			break;
354 
355 		default:
356 			// If we have reached this point then we have encountered a bug.
357 			ServerInstance->Logs->Log("SOCKET", LOG_DEBUG, "BUG: sa2cidr(): socket type %d is unknown!", cidr.type);
358 			cidr.length = 0;
359 			return;
360 	}
361 
362 	unsigned int border = cidr.length / 8;
363 	unsigned int bitmask = (0xFF00 >> (range & 7)) & 0xFF;
364 	for(unsigned int i=0; i < target_byte; i++)
365 	{
366 		if (i < border)
367 			cidr.bits[i] = base[i];
368 		else if (i == border)
369 			cidr.bits[i] = base[i] & bitmask;
370 		else
371 			return;
372 	}
373 }
374 
cidr_mask(const irc::sockets::sockaddrs & sa,unsigned char range)375 irc::sockets::cidr_mask::cidr_mask(const irc::sockets::sockaddrs& sa, unsigned char range)
376 {
377 	sa2cidr(*this, sa, range);
378 }
379 
cidr_mask(const std::string & mask)380 irc::sockets::cidr_mask::cidr_mask(const std::string& mask)
381 {
382 	std::string::size_type bits_chars = mask.rfind('/');
383 	irc::sockets::sockaddrs sa;
384 
385 	if (bits_chars == std::string::npos)
386 	{
387 		irc::sockets::aptosa(mask, 0, sa);
388 		sa2cidr(*this, sa, 128);
389 	}
390 	else
391 	{
392 		unsigned char range = ConvToNum<unsigned char>(mask.substr(bits_chars + 1));
393 		irc::sockets::aptosa(mask.substr(0, bits_chars), 0, sa);
394 		sa2cidr(*this, sa, range);
395 	}
396 }
397 
str() const398 std::string irc::sockets::cidr_mask::str() const
399 {
400 	irc::sockets::sockaddrs sa;
401 	sa.sa.sa_family = type;
402 
403 	unsigned char* base;
404 	size_t len;
405 	switch (type)
406 	{
407 		case AF_INET:
408 			base = (unsigned char*)&sa.in4.sin_addr;
409 			len = 4;
410 			break;
411 
412 		case AF_INET6:
413 			base = (unsigned char*)&sa.in6.sin6_addr;
414 			len = 16;
415 			break;
416 
417 		case AF_UNIX:
418 			return sa.un.sun_path;
419 
420 		default:
421 			// If we have reached this point then we have encountered a bug.
422 			ServerInstance->Logs->Log("SOCKET", LOG_DEBUG, "BUG: irc::sockets::cidr_mask::str(): socket type %d is unknown!", type);
423 			return "<unknown>";
424 	}
425 
426 	memcpy(base, bits, len);
427 	return sa.addr() + "/" + ConvToStr((int)length);
428 }
429 
operator ==(const cidr_mask & other) const430 bool irc::sockets::cidr_mask::operator==(const cidr_mask& other) const
431 {
432 	return type == other.type && length == other.length &&
433 		0 == memcmp(bits, other.bits, 16);
434 }
435 
operator <(const cidr_mask & other) const436 bool irc::sockets::cidr_mask::operator<(const cidr_mask& other) const
437 {
438 	if (type != other.type)
439 		return type < other.type;
440 	if (length != other.length)
441 		return length < other.length;
442 	return memcmp(bits, other.bits, 16) < 0;
443 }
444 
match(const irc::sockets::sockaddrs & addr) const445 bool irc::sockets::cidr_mask::match(const irc::sockets::sockaddrs& addr) const
446 {
447 	if (addr.family() != type)
448 		return false;
449 	irc::sockets::cidr_mask tmp(addr, length);
450 	return tmp == *this;
451 }
452