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Comparing gvpe/src/connection.C (file contents):
Revision 1.2 by pcg, Wed Apr 2 03:25:17 2003 UTC vs.
Revision 1.72 by pcg, Fri Aug 8 16:48:00 2008 UTC

1	/*	1	/*
2	connection.C -- manage a single connection	2	connection.C -- manage a single connection
		3	Copyright (C) 2003-2008 Marc Lehmann <gvpe@schmorp.de>
3		4
		5	This file is part of GVPE.
		6
4	This program is free software; you can redistribute it and/or modify	7	GVPE is free software; you can redistribute it and/or modify it
5	it under the terms of the GNU General Public License as published by	8	under the terms of the GNU General Public License as published by the
6	the Free Software Foundation; either version 2 of the License, or	9	Free Software Foundation; either version 3 of the License, or (at your
7	(at your option) any later version.	10	option) any later version.
8		11
9	This program is distributed in the hope that it will be useful,	12	This program is distributed in the hope that it will be useful, but
10	but WITHOUT ANY WARRANTY; without even the implied warranty of	13	WITHOUT ANY WARRANTY; without even the implied warranty of
11	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the	14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
12	GNU General Public License for more details.	15	Public License for more details.
13		16
14	You should have received a copy of the GNU General Public License	17	You should have received a copy of the GNU General Public License along
15	along with this program; if not, write to the Free Software	18	with this program; if not, see <http://www.gnu.org/licenses/>.
16	Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA	19
		20	Additional permission under GNU GPL version 3 section 7
		21
		22	If you modify this Program, or any covered work, by linking or
		23	combining it with the OpenSSL project's OpenSSL library (or a modified
		24	version of that library), containing parts covered by the terms of the
		25	OpenSSL or SSLeay licenses, the licensors of this Program grant you
		26	additional permission to convey the resulting work. Corresponding
		27	Source for a non-source form of such a combination shall include the
		28	source code for the parts of OpenSSL used as well as that of the
		29	covered work.
17	*/	30	*/
18		31
19	#include "config.h"	32	#include "config.h"
20		33
21	extern "C" {
22	# include "lzf/lzf.h"
23	}
24
25	#include <list>	34	#include <list>
		35	#include <queue>
		36	#include <utility>
26		37
27	#include <openssl/rand.h>	38	#include <openssl/rand.h>
28	#include <openssl/evp.h>	39	#include <openssl/evp.h>
29	#include <openssl/rsa.h>	40	#include <openssl/rsa.h>
30	#include <openssl/err.h>	41	#include <openssl/err.h>
31
32	#include "gettext.h"
33		42
34	#include "conf.h"	43	#include "conf.h"
35	#include "slog.h"	44	#include "slog.h"
36	#include "device.h"	45	#include "device.h"
37	#include "vpn.h"	46	#include "vpn.h"
38	#include "connection.h"	47	#include "connection.h"
39		48
		49	#include "netcompat.h"
		50
40	#if !HAVE_RAND_PSEUDO_BYTES	51	#if !HAVE_RAND_PSEUDO_BYTES
41	# define RAND_pseudo_bytes RAND_bytes	52	# define RAND_pseudo_bytes RAND_bytes
42	#endif	53	#endif
43		54
44	#define MAGIC "vped\xbd\xc6\xdb\x82" // 8 bytes of magic	55	#define MAGIC "vped\xbd\xc6\xdb\x82" // 8 bytes of magic
45		56
		57	#define ULTRA_FAST 1
		58	#define HLOG 15
		59	#include "lzf/lzf.h"
		60	#include "lzf/lzf_c.c"
		61	#include "lzf/lzf_d.c"
		62
		63	//////////////////////////////////////////////////////////////////////////////
		64
		65	static std::queue< std::pair<run_script_cb *, const char *> > rs_queue;
		66	static ev::child rs_child_ev;
		67
		68	void // c++ requires external linkage here, apparently :(
		69	rs_child_cb (ev::child &w, int revents)
		70	{
		71	w.stop ();
		72
		73	if (rs_queue.empty ())
		74	return;
		75
		76	pid_t pid = run_script (*rs_queue.front ().first, false);
		77	if (pid)
		78	{
		79	w.set (pid);
		80	w.start ();
		81	}
		82	else
		83	slog (L_WARN, rs_queue.front ().second);
		84
		85	delete rs_queue.front ().first;
		86	rs_queue.pop ();
		87	}
		88
		89	// despite the fancy name, this is quite a hack
		90	static void
		91	run_script_queued (run_script_cb *cb, const char *warnmsg)
		92	{
		93	rs_queue.push (std::make_pair (cb, warnmsg));
		94
		95	if (!rs_child_ev.is_active ())
		96	{
		97	rs_child_ev.set<rs_child_cb> ();
		98	rs_child_ev ();
		99	}
		100	}
		101
		102	//////////////////////////////////////////////////////////////////////////////
		103
46	struct crypto_ctx	104	struct crypto_ctx
47	{	105	{
48	EVP_CIPHER_CTX cctx;	106	EVP_CIPHER_CTX cctx;
49	HMAC_CTX hctx;	107	HMAC_CTX hctx;
50		108
…		…
53	};	111	};
54		112
55	crypto_ctx::crypto_ctx (const rsachallenge &challenge, int enc)	113	crypto_ctx::crypto_ctx (const rsachallenge &challenge, int enc)
56	{	114	{
57	EVP_CIPHER_CTX_init (&cctx);	115	EVP_CIPHER_CTX_init (&cctx);
58	EVP_CipherInit_ex (&cctx, CIPHER, 0, &challenge[CHG_CIPHER_KEY], 0, enc);	116	require (EVP_CipherInit_ex (&cctx, CIPHER, 0, &challenge[CHG_CIPHER_KEY], 0, enc));
59	HMAC_CTX_init (&hctx);	117	HMAC_CTX_init (&hctx);
60	HMAC_Init_ex (&hctx, &challenge[CHG_HMAC_KEY], HMAC_KEYLEN, DIGEST, 0);	118	HMAC_Init_ex (&hctx, &challenge[CHG_HMAC_KEY], HMAC_KEYLEN, DIGEST, 0);
61	}	119	}
62		120
63	crypto_ctx::~crypto_ctx ()	121	crypto_ctx::~crypto_ctx ()
64	{	122	{
65	EVP_CIPHER_CTX_cleanup (&cctx);	123	require (EVP_CIPHER_CTX_cleanup (&cctx));
66	HMAC_CTX_cleanup (&hctx);	124	HMAC_CTX_cleanup (&hctx);
67	}	125	}
68		126
69	static void	127	static void
70	rsa_hash (const rsaid &id, const rsachallenge &chg, rsaresponse &h)	128	rsa_hash (const rsaid &id, const rsachallenge &chg, rsaresponse &h)
71	{	129	{
72	EVP_MD_CTX ctx;	130	EVP_MD_CTX ctx;
73		131
74	EVP_MD_CTX_init (&ctx);	132	EVP_MD_CTX_init (&ctx);
75	EVP_DigestInit (&ctx, RSA_HASH);	133	require (EVP_DigestInit (&ctx, RSA_HASH));
76	EVP_DigestUpdate(&ctx, &chg, sizeof chg);	134	require (EVP_DigestUpdate(&ctx, &chg, sizeof chg));
77	EVP_DigestUpdate(&ctx, &id, sizeof id);	135	require (EVP_DigestUpdate(&ctx, &id, sizeof id));
78	EVP_DigestFinal (&ctx, (unsigned char *)&h, 0);	136	require (EVP_DigestFinal (&ctx, (unsigned char *)&h, 0));
79	EVP_MD_CTX_cleanup (&ctx);	137	EVP_MD_CTX_cleanup (&ctx);
80	}	138	}
81		139
82	struct rsa_entry {	140	struct rsa_entry
		141	{
83	tstamp expire;	142	tstamp expire;
84	rsaid id;	143	rsaid id;
85	rsachallenge chg;	144	rsachallenge chg;
86	};	145	};
87		146
88	struct rsa_cache : list<rsa_entry>	147	struct rsa_cache : list<rsa_entry>
89	{	148	{
90	void cleaner_cb (tstamp &ts); time_watcher cleaner;	149	inline void cleaner_cb (ev::timer &w, int revents); ev::timer cleaner;
91		150
92	bool find (const rsaid &id, rsachallenge &chg)	151	bool find (const rsaid &id, rsachallenge &chg)
93	{	152	{
94	for (iterator i = begin (); i != end (); ++i)	153	for (iterator i = begin (); i != end (); ++i)
95	{	154	{
96	if (!memcmp (&id, &i->id, sizeof id) && i->expire > NOW)	155	if (!memcmp (&id, &i->id, sizeof id) && i->expire > ev_now ())
97	{	156	{
98	memcpy (&chg, &i->chg, sizeof chg);	157	memcpy (&chg, &i->chg, sizeof chg);
99		158
100	erase (i);	159	erase (i);
101	return true;	160	return true;
102	}	161	}
103	}	162	}
104		163
105	if (cleaner.at < NOW)	164	if (!cleaner.is_active ())
106	cleaner.start (NOW + RSA_TTL);	165	cleaner.again ();
107		166
108	return false;	167	return false;
109	}	168	}
110		169
111	void gen (rsaid &id, rsachallenge &chg)	170	void gen (rsaid &id, rsachallenge &chg)
112	{	171	{
113	rsa_entry e;	172	rsa_entry e;
114		173
115	RAND_bytes ((unsigned char *)&id, sizeof id);	174	RAND_bytes ((unsigned char *)&id, sizeof id);
116	RAND_bytes ((unsigned char *)&chg, sizeof chg);	175	RAND_bytes ((unsigned char *)&chg, sizeof chg);
117		176
118	e.expire = NOW + RSA_TTL;	177	e.expire = ev_now () + RSA_TTL;
119	e.id = id;	178	e.id = id;
120	memcpy (&e.chg, &chg, sizeof chg);	179	memcpy (&e.chg, &chg, sizeof chg);
121		180
122	push_back (e);	181	push_back (e);
123		182
124	if (cleaner.at < NOW)	183	if (!cleaner.is_active ())
125	cleaner.start (NOW + RSA_TTL);	184	cleaner.again ();
126	}	185	}
127		186
128	rsa_cache ()	187	rsa_cache ()
129	: cleaner (this, &rsa_cache::cleaner_cb)	188	{
130	{ }	189	cleaner.set<rsa_cache, &rsa_cache::cleaner_cb> (this);
		190	cleaner.set (RSA_TTL, RSA_TTL);
		191	}
131		192
132	} rsa_cache;	193	} rsa_cache;
133		194
134	void rsa_cache::cleaner_cb (tstamp &ts)	195	void rsa_cache::cleaner_cb (ev::timer &w, int revents)
135	{	196	{
136	if (empty ())	197	if (empty ())
137	ts = TSTAMP_CANCEL;	198	w.stop ();
138	else	199	else
139	{	200	{
140	ts = NOW + RSA_TTL;
141
142	for (iterator i = begin (); i != end (); )	201	for (iterator i = begin (); i != end (); )
143	if (i->expire <= NOW)	202	if (i->expire <= ev_now ())
144	i = erase (i);	203	i = erase (i);
145	else	204	else
146	++i;	205	++i;
147	}	206	}
148	}	207	}
149		208
150	//////////////////////////////////////////////////////////////////////////////	209	//////////////////////////////////////////////////////////////////////////////
151		210
152	void pkt_queue::put (tap_packet *p)	211	pkt_queue::pkt_queue (double max_ttl, int max_queue)
		212	: max_ttl (max_ttl), max_queue (max_queue)
153	{	213	{
154	if (queue[i])	214	queue = new pkt [max_queue];
155	{
156	delete queue[i];
157	j = (j + 1) % QUEUEDEPTH;
158	}
159		215
160	queue[i] = p;
161
162	i = (i + 1) % QUEUEDEPTH;
163	}
164
165	tap_packet *pkt_queue::get ()
166	{
167	tap_packet *p = queue[j];
168
169	if (p)
170	{
171	queue[j] = 0;
172	j = (j + 1) % QUEUEDEPTH;
173	}
174
175	return p;
176	}
177
178	pkt_queue::pkt_queue ()
179	{
180	memset (queue, 0, sizeof (queue));
181	i = 0;	216	i = 0;
182	j = 0;	217	j = 0;
		218
		219	expire.set<pkt_queue, &pkt_queue::expire_cb> (this);
183	}	220	}
184		221
185	pkt_queue::~pkt_queue ()	222	pkt_queue::~pkt_queue ()
186	{	223	{
187	for (i = QUEUEDEPTH; --i > 0; )	224	while (net_packet *p = get ())
		225	delete p;
		226
188	delete queue[i];	227	delete [] queue;
189	}	228	}
190		229
		230	void pkt_queue::expire_cb (ev::timer &w, int revents)
		231	{
		232	ev_tstamp expire = ev_now () - max_ttl;
		233
		234	for (;;)
		235	{
		236	if (empty ())
		237	break;
		238
		239	double diff = queue[j].tstamp - expire;
		240
		241	if (diff >= 0.)
		242	{
		243	w.start (diff > 0.5 ? diff : 0.5);
		244	break;
		245	}
		246
		247	delete get ();
		248	}
		249	}
		250
		251	void pkt_queue::put (net_packet *p)
		252	{
		253	ev_tstamp now = ev_now ();
		254
		255	// start expiry timer
		256	if (empty ())
		257	expire.start (max_ttl);
		258
		259	int ni = i + 1 == max_queue ? 0 : i + 1;
		260
		261	if (ni == j)
		262	delete get ();
		263
		264	queue[i].pkt = p;
		265	queue[i].tstamp = now;
		266
		267	i = ni;
		268	}
		269
		270	net_packet *pkt_queue::get ()
		271	{
		272	if (empty ())
		273	return 0;
		274
		275	net_packet *p = queue[j].pkt;
		276	queue[j].pkt = 0;
		277
		278	j = j + 1 == max_queue ? 0 : j + 1;
		279
		280	return p;
		281	}
		282
191	struct net_rateinfo {	283	struct net_rateinfo
		284	{
192	u32 host;	285	u32 host;
193	double pcnt, diff;	286	double pcnt, diff;
194	tstamp last;	287	tstamp last;
195	};	288	};
196		289
197	// only do action once every x seconds per host whole allowing bursts.	290	// only do action once every x seconds per host whole allowing bursts.
198	// this implementation ("splay list" ;) is inefficient,	291	// this implementation ("splay list" ;) is inefficient,
199	// but low on resources.	292	// but low on resources.
200	struct net_rate_limiter : list<net_rateinfo>	293	struct net_rate_limiter : list<net_rateinfo>
201	{	294	{
202	static const double ALPHA = 1. - 1. / 90.; // allow bursts	295	# define NRL_ALPHA (1. - 1. / 600.) // allow bursts
203	static const double CUTOFF = 20.; // one event every CUTOFF seconds	296	# define NRL_CUTOFF 10. // one event every CUTOFF seconds
204	static const double EXPIRE = CUTOFF * 30.; // expire entries after this time	297	# define NRL_EXPIRE (NRL_CUTOFF * 30.) // expire entries after this time
		298	# define NRL_MAXDIF (NRL_CUTOFF * (1. / (1. - NRL_ALPHA))) // maximum diff /count value
205		299
206	bool can (const sockinfo &si) { return can((u32)si.host); }	300	bool can (const sockinfo &si) { return can((u32)si.host); }
207	bool can (u32 host);	301	bool can (u32 host);
208	};	302	};
209		303
210	net_rate_limiter auth_rate_limiter, reset_rate_limiter;	304	net_rate_limiter auth_rate_limiter, reset_rate_limiter;
211		305
…		…
214	iterator i;	308	iterator i;
215		309
216	for (i = begin (); i != end (); )	310	for (i = begin (); i != end (); )
217	if (i->host == host)	311	if (i->host == host)
218	break;	312	break;
219	else if (i->last < NOW - EXPIRE)	313	else if (i->last < ev_now () - NRL_EXPIRE)
220	i = erase (i);	314	i = erase (i);
221	else	315	else
222	i++;	316	i++;
223		317
224	if (i == end ())	318	if (i == end ())
225	{	319	{
226	net_rateinfo ri;	320	net_rateinfo ri;
227		321
228	ri.host = host;	322	ri.host = host;
229	ri.pcnt = 1.;	323	ri.pcnt = 1.;
230	ri.diff = CUTOFF * (1. / (1. - ALPHA));	324	ri.diff = NRL_MAXDIF;
231	ri.last = NOW;	325	ri.last = ev_now ();
232		326
233	push_front (ri);	327	push_front (ri);
234		328
235	return true;	329	return true;
236	}	330	}
237	else	331	else
238	{	332	{
239	net_rateinfo ri (*i);	333	net_rateinfo ri (*i);
240	erase (i);	334	erase (i);
241		335
242	ri.pcnt = ri.pcnt * ALPHA;	336	ri.pcnt = ri.pcnt * NRL_ALPHA;
243	ri.diff = ri.diff * ALPHA + (NOW - ri.last);	337	ri.diff = ri.diff * NRL_ALPHA + (ev_now () - ri.last);
244		338
245	ri.last = NOW;	339	ri.last = ev_now ();
246		340
		341	double dif = ri.diff / ri.pcnt;
		342
247	bool send = ri.diff / ri.pcnt > CUTOFF;	343	bool send = dif > NRL_CUTOFF;
248		344
		345	if (dif > NRL_MAXDIF)
		346	{
		347	ri.pcnt = 1.;
		348	ri.diff = NRL_MAXDIF;
		349	}
249	if (send)	350	else if (send)
250	ri.pcnt++;	351	ri.pcnt++;
251		352
252	push_front (ri);	353	push_front (ri);
253		354
254	return send;	355	return send;
…		…
285	hmac_gen (ctx);	386	hmac_gen (ctx);
286		387
287	return !memcmp (hmac, hmac_digest, HMACLENGTH);	388	return !memcmp (hmac, hmac_digest, HMACLENGTH);
288	}	389	}
289		390
290	void vpn_packet::set_hdr (ptype type, unsigned int dst)	391	void vpn_packet::set_hdr (ptype type_, unsigned int dst)
291	{	392	{
292	this->type = type;	393	type = type_;
293		394
294	int src = THISNODE->id;	395	int src = THISNODE->id;
295		396
296	src1 = src;	397	src1 = src;
297	srcdst = ((src >> 8) << 4) | (dst >> 8);	398	srcdst = ((src >> 8) << 4) | (dst >> 8);
…		…
299	}	400	}
300		401
301	#define MAXVPNDATA (MAX_MTU - 6 - 6)	402	#define MAXVPNDATA (MAX_MTU - 6 - 6)
302	#define DATAHDR (sizeof (u32) + RAND_SIZE)	403	#define DATAHDR (sizeof (u32) + RAND_SIZE)
303		404
304	struct vpndata_packet:vpn_packet	405	struct vpndata_packet : vpn_packet
305	{	406	{
306	u8 data[MAXVPNDATA + DATAHDR]; // seqno	407	u8 data[MAXVPNDATA + DATAHDR]; // seqno
307		408
308	void setup (connection *conn, int dst, u8 *d, u32 len, u32 seqno);	409	void setup (connection *conn, int dst, u8 *d, u32 len, u32 seqno);
309	tap_packet *unpack (connection *conn, u32 &seqno);	410	tap_packet *unpack (connection *conn, u32 &seqno);
…		…
322	int outl = 0, outl2;	423	int outl = 0, outl2;
323	ptype type = PT_DATA_UNCOMPRESSED;	424	ptype type = PT_DATA_UNCOMPRESSED;
324		425
325	#if ENABLE_COMPRESSION	426	#if ENABLE_COMPRESSION
326	u8 cdata[MAX_MTU];	427	u8 cdata[MAX_MTU];
327	u32 cl;
328		428
		429	if (conn->features & ENABLE_COMPRESSION)
		430	{
329	cl = lzf_compress (d, l, cdata + 2, (l - 2) & ~7);	431	u32 cl = lzf_compress (d, l, cdata + 2, (l - 2) & ~7);
		432
330	if (cl)	433	if (cl)
331	{	434	{
332	type = PT_DATA_COMPRESSED;	435	type = PT_DATA_COMPRESSED;
333	d = cdata;	436	d = cdata;
334	l = cl + 2;	437	l = cl + 2;
335		438
336	d[0] = cl >> 8;	439	d[0] = cl >> 8;
337	d[1] = cl;	440	d[1] = cl;
		441	}
338	}	442	}
339	#endif	443	#endif
340		444
341	EVP_EncryptInit_ex (cctx, 0, 0, 0, 0);	445	require (EVP_EncryptInit_ex (cctx, 0, 0, 0, 0));
342		446
343	struct {	447	struct {
344	#if RAND_SIZE	448	#if RAND_SIZE
345	u8 rnd[RAND_SIZE];	449	u8 rnd[RAND_SIZE];
346	#endif	450	#endif
…		…
350	datahdr.seqno = ntohl (seqno);	454	datahdr.seqno = ntohl (seqno);
351	#if RAND_SIZE	455	#if RAND_SIZE
352	RAND_pseudo_bytes ((unsigned char *) datahdr.rnd, RAND_SIZE);	456	RAND_pseudo_bytes ((unsigned char *) datahdr.rnd, RAND_SIZE);
353	#endif	457	#endif
354		458
355	EVP_EncryptUpdate (cctx,	459	require (EVP_EncryptUpdate (cctx,
356	(unsigned char *) data + outl, &outl2,	460	(unsigned char *) data + outl, &outl2,
357	(unsigned char *) &datahdr, DATAHDR);	461	(unsigned char *) &datahdr, DATAHDR));
358	outl += outl2;	462	outl += outl2;
359		463
360	EVP_EncryptUpdate (cctx,	464	require (EVP_EncryptUpdate (cctx,
361	(unsigned char *) data + outl, &outl2,	465	(unsigned char *) data + outl, &outl2,
362	(unsigned char *) d, l);	466	(unsigned char *) d, l));
363	outl += outl2;	467	outl += outl2;
364		468
365	EVP_EncryptFinal_ex (cctx, (unsigned char *) data + outl, &outl2);	469	require (EVP_EncryptFinal_ex (cctx, (unsigned char *) data + outl, &outl2));
366	outl += outl2;	470	outl += outl2;
367		471
368	len = outl + data_hdr_size ();	472	len = outl + data_hdr_size ();
369		473
370	set_hdr (type, dst);	474	set_hdr (type, dst);
…		…
379	int outl = 0, outl2;	483	int outl = 0, outl2;
380	tap_packet *p = new tap_packet;	484	tap_packet *p = new tap_packet;
381	u8 *d;	485	u8 *d;
382	u32 l = len - data_hdr_size ();	486	u32 l = len - data_hdr_size ();
383		487
384	EVP_DecryptInit_ex (cctx, 0, 0, 0, 0);	488	require (EVP_DecryptInit_ex (cctx, 0, 0, 0, 0));
385		489
386	#if ENABLE_COMPRESSION	490	#if ENABLE_COMPRESSION
387	u8 cdata[MAX_MTU];	491	u8 cdata[MAX_MTU];
388		492
389	if (type == PT_DATA_COMPRESSED)	493	if (type == PT_DATA_COMPRESSED)
…		…
391	else	495	else
392	#endif	496	#endif
393	d = &(*p)[6 + 6 - DATAHDR];	497	d = &(*p)[6 + 6 - DATAHDR];
394		498
395	/* this overwrites part of the src mac, but we fix that later */	499	/* this overwrites part of the src mac, but we fix that later */
396	EVP_DecryptUpdate (cctx,	500	require (EVP_DecryptUpdate (cctx,
397	d, &outl2,	501	d, &outl2,
398	(unsigned char *)&data, len - data_hdr_size ());	502	(unsigned char *)&data, len - data_hdr_size ()));
399	outl += outl2;	503	outl += outl2;
400		504
401	EVP_DecryptFinal_ex (cctx, (unsigned char *)d + outl, &outl2);	505	require (EVP_DecryptFinal_ex (cctx, (unsigned char *)d + outl, &outl2));
402	outl += outl2;	506	outl += outl2;
403		507
404	seqno = ntohl (*(u32 *)(d + RAND_SIZE));	508	seqno = ntohl (*(u32 *)(d + RAND_SIZE));
405		509
406	id2mac (dst () ? dst() : THISNODE->id, p->dst);	510	id2mac (dst () ? dst() : THISNODE->id, p->dst);
…		…
435	{	539	{
436	// actually, hmaclen cannot be checked because the hmac	540	// actually, hmaclen cannot be checked because the hmac
437	// field comes before this data, so peers with other	541	// field comes before this data, so peers with other
438	// hmacs simply will not work.	542	// hmacs simply will not work.
439	u8 prot_major, prot_minor, randsize, hmaclen;	543	u8 prot_major, prot_minor, randsize, hmaclen;
440	u8 flags, challengelen, pad2, pad3;	544	u8 flags, challengelen, features, pad3;
441	u32 cipher_nid, digest_nid, hmac_nid;	545	u32 cipher_nid, digest_nid, hmac_nid;
442
443	const u8 curflags () const
444	{
445	return 0x80
446	| (ENABLE_COMPRESSION ? 0x01 : 0x00);
447	}
448		546
449	void setup (ptype type, int dst);	547	void setup (ptype type, int dst);
450	bool chk_config () const;	548	bool chk_config () const;
		549
		550	static u8 get_features ()
		551	{
		552	u8 f = 0;
		553	#if ENABLE_COMPRESSION
		554	f |= FEATURE_COMPRESSION;
		555	#endif
		556	#if ENABLE_ROHC
		557	f |= FEATURE_ROHC;
		558	#endif
		559	#if ENABLE_BRIDGING
		560	f |= FEATURE_BRIDGING;
		561	#endif
		562	return f;
		563	}
451	};	564	};
452		565
453	void config_packet::setup (ptype type, int dst)	566	void config_packet::setup (ptype type, int dst)
454	{	567	{
455	prot_major = PROTOCOL_MAJOR;	568	prot_major = PROTOCOL_MAJOR;
456	prot_minor = PROTOCOL_MINOR;	569	prot_minor = PROTOCOL_MINOR;
457	randsize = RAND_SIZE;	570	randsize = RAND_SIZE;
458	hmaclen = HMACLENGTH;	571	hmaclen = HMACLENGTH;
459	flags = curflags ();	572	flags = 0;
460	challengelen = sizeof (rsachallenge);	573	challengelen = sizeof (rsachallenge);
		574	features = get_features ();
461		575
462	cipher_nid = htonl (EVP_CIPHER_nid (CIPHER));	576	cipher_nid = htonl (EVP_CIPHER_nid (CIPHER));
463	digest_nid = htonl (EVP_MD_type (RSA_HASH));	577	digest_nid = htonl (EVP_MD_type (RSA_HASH));
464	hmac_nid = htonl (EVP_MD_type (DIGEST));	578	hmac_nid = htonl (EVP_MD_type (DIGEST));
465		579
…		…
467	set_hdr (type, dst);	581	set_hdr (type, dst);
468	}	582	}
469		583
470	bool config_packet::chk_config () const	584	bool config_packet::chk_config () const
471	{	585	{
472	return prot_major == PROTOCOL_MAJOR	586	if (prot_major != PROTOCOL_MAJOR)
473	&& randsize == RAND_SIZE	587	slog (L_WARN, _("major version mismatch (remote %d <=> local %d)"), prot_major, PROTOCOL_MAJOR);
474	&& hmaclen == HMACLENGTH	588	else if (randsize != RAND_SIZE)
475	&& flags == curflags ()	589	slog (L_WARN, _("rand size mismatch (remote %d <=> local %d)"), randsize, RAND_SIZE);
		590	else if (hmaclen != HMACLENGTH)
		591	slog (L_WARN, _("hmac length mismatch (remote %d <=> local %d)"), hmaclen, HMACLENGTH);
476	&& challengelen == sizeof (rsachallenge)	592	else if (challengelen != sizeof (rsachallenge))
		593	slog (L_WARN, _("challenge length mismatch (remote %d <=> local %d)"), challengelen, sizeof (rsachallenge));
477	&& cipher_nid == htonl (EVP_CIPHER_nid (CIPHER))	594	else if (cipher_nid != htonl (EVP_CIPHER_nid (CIPHER)))
		595	slog (L_WARN, _("cipher mismatch (remote %x <=> local %x)"), ntohl (cipher_nid), EVP_CIPHER_nid (CIPHER));
478	&& digest_nid == htonl (EVP_MD_type (RSA_HASH))	596	else if (digest_nid != htonl (EVP_MD_type (RSA_HASH)))
		597	slog (L_WARN, _("digest mismatch (remote %x <=> local %x)"), ntohl (digest_nid), EVP_MD_type (RSA_HASH));
479	&& hmac_nid == htonl (EVP_MD_type (DIGEST));	598	else if (hmac_nid != htonl (EVP_MD_type (DIGEST)))
		599	slog (L_WARN, _("hmac mismatch (remote %x <=> local %x)"), ntohl (hmac_nid), EVP_MD_type (DIGEST));
		600	else
		601	return true;
		602
		603	return false;
480	}	604	}
481		605
482	struct auth_req_packet : config_packet	606	struct auth_req_packet : config_packet
483	{	607	{
484	char magic[8];	608	char magic[8];
485	u8 initiate; // false if this is just an automatic reply	609	u8 initiate; // false if this is just an automatic reply
486	u8 protocols; // supported protocols (will get patches on forward)	610	u8 protocols; // supported protocols (will be patched on forward)
487	u8 pad2, pad3;	611	u8 pad2, pad3;
488	rsaid id;	612	rsaid id;
489	rsaencrdata encr;	613	rsaencrdata encr;
490		614
491	auth_req_packet (int dst, bool initiate_, u8 protocols_)	615	auth_req_packet (int dst, bool initiate_, u8 protocols_)
…		…
546	};	670	};
547		671
548	/////////////////////////////////////////////////////////////////////////////	672	/////////////////////////////////////////////////////////////////////////////
549		673
550	void	674	void
		675	connection::connection_established ()
		676	{
		677	slog (L_TRACE, _("%s: possible connection establish (ictx %d, octx %d)"), conf->nodename, !!ictx, !!octx);
		678
		679	if (ictx && octx)
		680	{
		681	// make sure rekeying timeouts are slightly asymmetric
		682	ev::tstamp rekey_interval = ::conf.rekey + (conf->id > THISNODE->id ? 10 : 0);
		683	rekey.start (rekey_interval, rekey_interval);
		684	keepalive.start (::conf.keepalive);
		685
		686	// send queued packets
		687	if (ictx && octx)
		688	{
		689	while (tap_packet *p = (tap_packet *)data_queue.get ())
		690	{
		691	if (p->len) send_data_packet (p);
		692	delete p;
		693	}
		694
		695	while (vpn_packet *p = (vpn_packet *)vpn_queue.get ())
		696	{
		697	if (p->len) send_vpn_packet (p, si, IPTOS_RELIABILITY);
		698	delete p;
		699	}
		700	}
		701	}
		702	else
		703	{
		704	retry_cnt = 0;
		705	establish_connection.start (5);
		706	keepalive.stop ();
		707	rekey.stop ();
		708	}
		709	}
		710
		711	void
551	connection::reset_dstaddr ()	712	connection::reset_si ()
552	{	713	{
		714	protocol = best_protocol (THISNODE->protocols & conf->protocols);
		715
		716	// mask out endpoints we can't connect to
		717	if (!conf->udp_port) protocol &= ~PROT_UDPv4;
		718	if (!conf->tcp_port) protocol &= ~PROT_TCPv4;
		719	if (!conf->dns_port) protocol &= ~PROT_DNSv4;
		720
		721	if (protocol
		722	&& (!conf->can_direct (THISNODE)
		723	|| !THISNODE->can_direct (conf)))
		724	{
		725	slog (L_DEBUG, _("%s: direct connection denied"), conf->nodename);
		726	protocol = 0;
		727	}
		728
553	si.set (conf);	729	si.set (conf, protocol);
		730	}
		731
		732	// ensure sockinfo is valid, forward if necessary
		733	const sockinfo &
		734	connection::forward_si (const sockinfo &si) const
		735	{
		736	if (!si.valid ())
		737	{
		738	connection *r = vpn->find_router ();
		739
		740	if (r)
		741	{
		742	slog (L_DEBUG, _("%s: no common protocol, trying indirectly through %s (%s)"),
		743	conf->nodename, r->conf->nodename, (const char *)r->si);
		744	return r->si;
		745	}
		746	else
		747	slog (L_DEBUG, _("%s: node unreachable, no common protocol, no router"),
		748	conf->nodename);
		749	}
		750
		751	return si;
		752	}
		753
		754	void
		755	connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos)
		756	{
		757	if (!vpn->send_vpn_packet (pkt, si, tos))
		758	reset_connection ();
554	}	759	}
555		760
556	void	761	void
557	connection::send_ping (const sockinfo &si, u8 pong)	762	connection::send_ping (const sockinfo &si, u8 pong)
558	{	763	{
…		…
581	void	786	void
582	connection::send_auth_request (const sockinfo &si, bool initiate)	787	connection::send_auth_request (const sockinfo &si, bool initiate)
583	{	788	{
584	auth_req_packet *pkt = new auth_req_packet (conf->id, initiate, THISNODE->protocols);	789	auth_req_packet *pkt = new auth_req_packet (conf->id, initiate, THISNODE->protocols);
585		790
586	protocol = best_protocol (THISNODE->protocols & conf->protocols);
587
588	// mask out protocols we cannot establish
589	if (!conf->udp_port) protocol &= ~PROT_UDPv4;
590	if (!conf->tcp_port) protocol &= ~PROT_TCPv4;
591
592	if (protocol)
593	{
594	rsachallenge chg;	791	rsachallenge chg;
595
596	rsa_cache.gen (pkt->id, chg);	792	rsa_cache.gen (pkt->id, chg);
		793	rsa_encrypt (conf->rsa_key, chg, pkt->encr);
597		794
598	if (0 > RSA_public_encrypt (sizeof chg,
599	(unsigned char *)&chg, (unsigned char *)&pkt->encr,
600	conf->rsa_key, RSA_PKCS1_OAEP_PADDING))
601	fatal ("RSA_public_encrypt error");
602
603	slog (L_TRACE, ">>%d PT_AUTH_REQ [%s]", conf->id, (const char *)si);	795	slog (L_TRACE, ">>%d PT_AUTH_REQ [%s]", conf->id, (const char *)si);
604		796
605	send_vpn_packet (pkt, si, IPTOS_RELIABILITY); // rsa is very very costly	797	send_vpn_packet (pkt, si, IPTOS_RELIABILITY | IPTOS_LOWDELAY); // rsa is very very costly
606		798
607	delete pkt;	799	delete pkt;
608	}
609	else
610	; // silently fail
611	}	800	}
612		801
613	void	802	void
614	connection::send_auth_response (const sockinfo &si, const rsaid &id, const rsachallenge &chg)	803	connection::send_auth_response (const sockinfo &si, const rsaid &id, const rsachallenge &chg)
615	{	804	{
…		…
629	}	818	}
630		819
631	void	820	void
632	connection::send_connect_info (int rid, const sockinfo &rsi, u8 rprotocols)	821	connection::send_connect_info (int rid, const sockinfo &rsi, u8 rprotocols)
633	{	822	{
634	slog (L_TRACE, ">>%d PT_CONNECT_INFO(%d,%s)\n",	823	slog (L_TRACE, ">>%d PT_CONNECT_INFO(%d,%s)",
635	conf->id, rid, (const char *)rsi);	824	conf->id, rid, (const char *)rsi);
636		825
637	connect_info_packet *r = new connect_info_packet (conf->id, rid, rsi, rprotocols);	826	connect_info_packet *r = new connect_info_packet (conf->id, rid, rsi, rprotocols);
638		827
639	r->hmac_set (octx);	828	r->hmac_set (octx);
640	send_vpn_packet (r, si);	829	send_vpn_packet (r, si);
641		830
642	delete r;	831	delete r;
643	}	832	}
644		833
645	void	834	inline void
646	connection::establish_connection_cb (tstamp &ts)	835	connection::establish_connection_cb (ev::timer &w, int revents)
647	{	836	{
648	if (ictx || conf == THISNODE	837	if (!ictx
		838	&& conf != THISNODE
649	|| connectmode == conf_node::C_NEVER	839	&& connectmode != conf_node::C_NEVER
650	|| connectmode == conf_node::C_DISABLED)	840	&& connectmode != conf_node::C_DISABLED
651	ts = TSTAMP_CANCEL;	841	&& !w.is_active ())
652	else if (ts <= NOW)
653	{	842	{
654	double retry_int = double (retry_cnt & 3 ? (retry_cnt & 3) : 1 << (retry_cnt >> 2)) * 0.6;	843	// a bit hacky, if ondemand, and packets are no longer queued, then reset the connection
655		844	// and stop trying. should probably be handled by a per-connection expire handler.
656	if (retry_int < 3600 * 8)	845	if (connectmode == conf_node::C_ONDEMAND && vpn_queue.empty () && data_queue.empty ())
657	retry_cnt++;
658
659	ts = NOW + retry_int;
660
661	if (conf->hostname)
662	{	846	{
663	reset_dstaddr ();	847	reset_connection ();
664	if (si.host && auth_rate_limiter.can (si))	848	return;
665	{
666	if (retry_cnt < 4)
667	send_auth_request (si, true);
668	else
669	send_ping (si, 0);
670	}	849	}
		850
		851	last_establish_attempt = ev_now ();
		852
		853	ev::tstamp retry_int = ev::tstamp (retry_cnt & 3
		854	? (retry_cnt & 3) + 1
		855	: 1 << (retry_cnt >> 2));
		856
		857	reset_si ();
		858
		859	bool slow = si.prot & PROT_SLOW;
		860
		861	if (si.prot && !si.host)
		862	{
		863	slog (L_TRACE, _("%s: connection request (indirect)"), conf->nodename);
		864	/*TODO*/ /* start the timer so we don't recurse endlessly */
		865	w.start (1);
		866	vpn->send_connect_request (conf->id);
671	}	867	}
672	else	868	else
673	vpn->connect_request (conf->id);	869	{
		870	slog (L_TRACE, _("%s: connection request (direct)"), conf->nodename, !!ictx, !!octx);
		871
		872	const sockinfo &dsi = forward_si (si);
		873
		874	slow = slow || (dsi.prot & PROT_SLOW);
		875
		876	if (dsi.valid () && auth_rate_limiter.can (dsi))
		877	{
		878	if (retry_cnt < 4)
		879	send_auth_request (dsi, true);
		880	else
		881	send_ping (dsi, 0);
		882	}
		883	}
		884
		885	retry_int *= slow ? 8. : 0.9;
		886
		887	if (retry_int < conf->max_retry)
		888	retry_cnt++;
		889	else
		890	retry_int = conf->max_retry;
		891
		892	w.start (retry_int);
674	}	893	}
675	}	894	}
676		895
677	void	896	void
678	connection::reset_connection ()	897	connection::reset_connection ()
…		…
681	{	900	{
682	slog (L_INFO, _("%s(%s): connection lost"),	901	slog (L_INFO, _("%s(%s): connection lost"),
683	conf->nodename, (const char *)si);	902	conf->nodename, (const char *)si);
684		903
685	if (::conf.script_node_down)	904	if (::conf.script_node_down)
686	run_script (run_script_cb (this, &connection::script_node_down), false);	905	{
		906	run_script_cb *cb = new run_script_cb;
		907	cb->set<connection, &connection::script_node_down> (this);
		908	run_script_queued (cb, _("node-down command execution failed, continuing."));
		909	}
687	}	910	}
688		911
689	delete ictx; ictx = 0;	912	delete ictx; ictx = 0;
690	delete octx; octx = 0;	913	delete octx; octx = 0;
		914	#if ENABLE_DNS
		915	dnsv4_reset_connection ();
		916	#endif
691		917
692	si.host= 0;	918	si.host = 0;
693		919
694	last_activity = 0;	920	last_activity = 0;
695	retry_cnt = 0;	921	retry_cnt = 0;
696		922
697	rekey.reset ();	923	rekey.stop ();
698	keepalive.reset ();	924	keepalive.stop ();
699	establish_connection.reset ();	925	establish_connection.stop ();
700	}	926	}
701		927
702	void	928	void
703	connection::shutdown ()	929	connection::shutdown ()
704	{	930	{
…		…
706	send_reset (si);	932	send_reset (si);
707		933
708	reset_connection ();	934	reset_connection ();
709	}	935	}
710		936
711	void	937	inline void
712	connection::rekey_cb (tstamp &ts)	938	connection::rekey_cb (ev::timer &w, int revents)
713	{	939	{
714	ts = TSTAMP_CANCEL;
715
716	reset_connection ();	940	reset_connection ();
717	establish_connection ();	941	establish_connection ();
718	}	942	}
719		943
720	void	944	void
721	connection::send_data_packet (tap_packet *pkt, bool broadcast)	945	connection::send_data_packet (tap_packet *pkt)
722	{	946	{
723	vpndata_packet *p = new vpndata_packet;	947	vpndata_packet *p = new vpndata_packet;
724	int tos = 0;	948	int tos = 0;
725		949
726	if (conf->inherit_tos	950	// I am not hilarious about peeking into packets, but so be it.
727	&& (*pkt)[12] == 0x08 && (*pkt)[13] == 0x00 // IP	951	if (conf->inherit_tos && pkt->is_ipv4 ())
728	&& ((*pkt)[14] & 0xf0) == 0x40) // IPv4
729	tos = (*pkt)[15] & IPTOS_TOS_MASK;	952	tos = (*pkt)[15] & IPTOS_TOS_MASK;
730		953
731	p->setup (this, broadcast ? 0 : conf->id, &((*pkt)[6 + 6]), pkt->len - 6 - 6, ++oseqno); // skip 2 macs	954	p->setup (this, conf->id, &((*pkt)[6 + 6]), pkt->len - 6 - 6, ++oseqno); // skip 2 macs
732	send_vpn_packet (p, si, tos);	955	send_vpn_packet (p, si, tos);
733		956
734	delete p;	957	delete p;
735		958
736	if (oseqno > MAX_SEQNO)	959	if (oseqno > MAX_SEQNO)
737	rekey ();	960	rekey ();
738	}	961	}
739		962
740	void	963	void
		964	connection::post_inject_queue ()
		965	{
		966	// force a connection every now and when when packets are sent (max 1/s)
		967	if (ev_now () - last_establish_attempt >= 0.95) // arbitrary
		968	establish_connection.stop ();
		969
		970	establish_connection ();
		971	}
		972
		973	void
741	connection::inject_data_packet (tap_packet *pkt, bool broadcast)	974	connection::inject_data_packet (tap_packet *pkt)
742	{	975	{
743	if (ictx && octx)	976	if (ictx && octx)
744	send_data_packet (pkt, broadcast);	977	send_data_packet (pkt);
745	else	978	else
746	{	979	{
747	if (!broadcast)//DDDD
748	queue.put (new tap_packet (*pkt));	980	data_queue.put (new tap_packet (*pkt));
		981	post_inject_queue ();
		982	}
		983	}
749		984
750	establish_connection ();	985	void connection::inject_vpn_packet (vpn_packet *pkt, int tos)
		986	{
		987	if (ictx && octx)
		988	send_vpn_packet (pkt, si, tos);
		989	else
		990	{
		991	vpn_queue.put ((vpn_packet *)new data_packet (*(data_packet *)pkt));
		992	post_inject_queue ();
751	}	993	}
752	}	994	}
753		995
754	void	996	void
755	connection::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi)	997	connection::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi)
756	{	998	{
757	last_activity = NOW;	999	last_activity = ev_now ();
758		1000
759	slog (L_NOISE, "<<%d received packet type %d from %d to %d",	1001	slog (L_NOISE, "<<%d received packet type %d from %d to %d",
760	conf->id, pkt->typ (), pkt->src (), pkt->dst ());	1002	conf->id, pkt->typ (), pkt->src (), pkt->dst ());
761		1003
		1004	if (connectmode == conf_node::C_DISABLED)
		1005	return;
		1006
762	switch (pkt->typ ())	1007	switch (pkt->typ ())
763	{	1008	{
764	case vpn_packet::PT_PING:	1009	case vpn_packet::PT_PING:
765	// we send pings instead of auth packets after some retries,	1010	// we send pings instead of auth packets after some retries,
766	// so reset the retry counter and establish a connection	1011	// so reset the retry counter and establish a connection
767	// when we receive a ping.	1012	// when we receive a ping.
768	if (!ictx)	1013	if (!ictx)
		1014	{
		1015	if (auth_rate_limiter.can (rsi))
		1016	send_auth_request (rsi, true);
		1017	}
		1018	else
		1019	send_ping (rsi, 1); // pong
		1020
		1021	break;
		1022
		1023	case vpn_packet::PT_PONG:
		1024	break;
		1025
		1026	case vpn_packet::PT_RESET:
769	{	1027	{
770	if (auth_rate_limiter.can (rsi))	1028	reset_connection ();
771	send_auth_request (rsi, true);	1029
		1030	config_packet *p = (config_packet *) pkt;
		1031
		1032	if (!p->chk_config ())
		1033	{
		1034	slog (L_WARN, _("%s(%s): protocol mismatch, disabling node"),
		1035	conf->nodename, (const char *)rsi);
		1036	connectmode = conf_node::C_DISABLED;
		1037	}
		1038	else if (connectmode == conf_node::C_ALWAYS)
		1039	establish_connection ();
772	}	1040	}
773	else
774	send_ping (rsi, 1); // pong
775
776	break;	1041	break;
777		1042
778	case vpn_packet::PT_PONG:
779	break;
780
781	case vpn_packet::PT_RESET:	1043	case vpn_packet::PT_AUTH_REQ:
782	{	1044	if (auth_rate_limiter.can (rsi))
783	reset_connection ();
784
785	config_packet *p = (config_packet *) pkt;
786
787	if (!p->chk_config ())
788	{	1045	{
		1046	auth_req_packet *p = (auth_req_packet *) pkt;
		1047
		1048	slog (L_TRACE, "<<%d PT_AUTH_REQ(%d)", conf->id, p->initiate);
		1049
		1050	if (p->chk_config () && !strncmp (p->magic, MAGIC, 8))
		1051	{
		1052	if (p->prot_minor != PROTOCOL_MINOR)
		1053	slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."),
		1054	conf->nodename, (const char *)rsi,
		1055	PROTOCOL_MINOR, conf->nodename, p->prot_minor);
		1056
		1057	if (p->initiate)
		1058	send_auth_request (rsi, false);
		1059
		1060	rsachallenge k;
		1061
		1062	if (!rsa_decrypt (::conf.rsa_key, p->encr, k))
		1063	{
		1064	slog (L_ERR, _("%s(%s): challenge illegal or corrupted (%s). mismatched key or config file?"),
		1065	conf->nodename, (const char *)rsi, ERR_error_string (ERR_get_error (), 0));
		1066	break;
		1067	}
		1068	else
		1069	{
		1070	delete octx;
		1071
		1072	octx = new crypto_ctx (k, 1);
		1073	oseqno = ntohl (*(u32 *)&k[CHG_SEQNO]) & 0x7fffffff;
		1074
		1075	conf->protocols = p->protocols;
		1076	features = p->features & config_packet::get_features ();
		1077
		1078	send_auth_response (rsi, p->id, k);
		1079
		1080	connection_established ();
		1081
		1082	break;
		1083	}
		1084	}
		1085	else
789	slog (L_WARN, _("%s(%s): protocol mismatch, disabling node"),	1086	slog (L_WARN, _("%s(%s): protocol mismatch"),
790	conf->nodename, (const char *)rsi);	1087	conf->nodename, (const char *)rsi);
791	connectmode = conf_node::C_DISABLED;	1088
		1089	send_reset (rsi);
792	}	1090	}
793	else if (connectmode == conf_node::C_ALWAYS)	1091
794	establish_connection ();
795	}
796	break;	1092	break;
797		1093
798	case vpn_packet::PT_AUTH_REQ:	1094	case vpn_packet::PT_AUTH_RES:
799	if (auth_rate_limiter.can (rsi))
800	{	1095	{
801	auth_req_packet *p = (auth_req_packet *) pkt;	1096	auth_res_packet *p = (auth_res_packet *) pkt;
802		1097
803	slog (L_TRACE, "<<%d PT_AUTH_REQ(%d)", conf->id, p->initiate);	1098	slog (L_TRACE, "<<%d PT_AUTH_RES", conf->id);
804		1099
805	if (p->chk_config () && !strncmp (p->magic, MAGIC, 8))	1100	if (p->chk_config ())
806	{	1101	{
807	if (p->prot_minor != PROTOCOL_MINOR)	1102	if (p->prot_minor != PROTOCOL_MINOR)
808	slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."),	1103	slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."),
809	conf->nodename, (const char *)rsi,	1104	conf->nodename, (const char *)rsi,
810	PROTOCOL_MINOR, conf->nodename, p->prot_minor);	1105	PROTOCOL_MINOR, conf->nodename, p->prot_minor);
811		1106
812	if (p->initiate)
813	send_auth_request (rsi, false);
814
815	rsachallenge k;	1107	rsachallenge chg;
816		1108
817	if (0 > RSA_private_decrypt (sizeof (p->encr),	1109	if (!rsa_cache.find (p->id, chg))
818	(unsigned char *)&p->encr, (unsigned char *)&k,	1110	{
819	::conf.rsa_key, RSA_PKCS1_OAEP_PADDING))	1111	slog (L_ERR, _("%s(%s): unrequested auth response ignored"),
820	slog (L_ERR, _("%s(%s): challenge illegal or corrupted"),
821	conf->nodename, (const char *)rsi);	1112	conf->nodename, (const char *)rsi);
		1113	break;
		1114	}
822	else	1115	else
823	{	1116	{
824	retry_cnt = 0;	1117	crypto_ctx *cctx = new crypto_ctx (chg, 0);
825	establish_connection.set (NOW + 8); //? ;)	1118
826	keepalive.reset ();	1119	if (!p->hmac_chk (cctx))
		1120	{
		1121	slog (L_ERR, _("%s(%s): hmac authentication error on auth response, received invalid packet\n"
		1122	"could be an attack, or just corruption or a synchronization error"),
		1123	conf->nodename, (const char *)rsi);
		1124	break;
		1125	}
827	rekey.reset ();	1126	else
		1127	{
		1128	rsaresponse h;
828		1129
		1130	rsa_hash (p->id, chg, h);
		1131
		1132	if (!memcmp ((u8 *)&h, (u8 *)p->response, sizeof h))
		1133	{
		1134	prot_minor = p->prot_minor;
		1135
		1136	delete ictx; ictx = cctx;
		1137
		1138	iseqno.reset (ntohl (*(u32 *)&chg[CHG_SEQNO]) & 0x7fffffff); // at least 2**31 sequence numbers are valid
		1139
		1140	si = rsi;
		1141	protocol = rsi.prot;
		1142
		1143	connection_established ();
		1144
		1145	slog (L_INFO, _("%s(%s): connection established, protocol version %d.%d"),
		1146	conf->nodename, (const char *)rsi,
		1147	p->prot_major, p->prot_minor);
		1148
		1149	if (::conf.script_node_up)
		1150	{
		1151	run_script_cb *cb = new run_script_cb;
		1152	cb->set<connection, &connection::script_node_up> (this);
		1153	run_script_queued (cb, _("node-up command execution failed, continuing."));
		1154	}
		1155
		1156	break;
		1157	}
		1158	else
		1159	slog (L_ERR, _("%s(%s): sent and received challenge do not match"),
		1160	conf->nodename, (const char *)rsi);
		1161	}
		1162
829	delete ictx;	1163	delete cctx;
830	ictx = 0;
831
832	delete octx;
833
834	octx = new crypto_ctx (k, 1);
835	oseqno = ntohl (*(u32 *)&k[CHG_SEQNO]) & 0x7fffffff;
836
837	conf->protocols = p->protocols;
838	send_auth_response (rsi, p->id, k);
839
840	break;
841	}	1164	}
842	}	1165	}
843
844	send_reset (rsi);
845	}	1166	}
846		1167
		1168	send_reset (rsi);
847	break;	1169	break;
848		1170
849	case vpn_packet::PT_AUTH_RES:	1171	case vpn_packet::PT_DATA_COMPRESSED:
850	{	1172	#if !ENABLE_COMPRESSION
851	auth_res_packet *p = (auth_res_packet *) pkt;	1173	send_reset (rsi);
		1174	break;
		1175	#endif
852		1176
853	slog (L_TRACE, "<<%d PT_AUTH_RES", conf->id);	1177	case vpn_packet::PT_DATA_UNCOMPRESSED:
854		1178
855	if (p->chk_config ())	1179	if (ictx && octx)
856	{	1180	{
857	if (p->prot_minor != PROTOCOL_MINOR)	1181	vpndata_packet *p = (vpndata_packet *)pkt;
858	slog (L_INFO, _("%s(%s): protocol minor version mismatch: ours is %d, %s's is %d."),
859	conf->nodename, (const char *)rsi,
860	PROTOCOL_MINOR, conf->nodename, p->prot_minor);
861		1182
862	rsachallenge chg;	1183	if (!p->hmac_chk (ictx))
863		1184	slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n"
864	if (!rsa_cache.find (p->id, chg))	1185	"could be an attack, or just corruption or a synchronization error"),
865	slog (L_ERR, _("%s(%s): unrequested auth response"),
866	conf->nodename, (const char *)rsi);	1186	conf->nodename, (const char *)rsi);
867	else	1187	else
868	{	1188	{
869	crypto_ctx *cctx = new crypto_ctx (chg, 0);
870
871	if (!p->hmac_chk (cctx))
872	slog (L_ERR, _("%s(%s): hmac authentication error on auth response, received invalid packet\n"
873	"could be an attack, or just corruption or an synchronization error"),
874	conf->nodename, (const char *)rsi);
875	else	1189	u32 seqno;
		1190	tap_packet *d = p->unpack (this, seqno);
		1191
		1192	if (iseqno.recv_ok (seqno))
876	{	1193	{
877	rsaresponse h;	1194	vpn->tap->send (d);
878		1195
879	rsa_hash (p->id, chg, h);	1196	if (si != rsi)
880
881	if (!memcmp ((u8 *)&h, (u8 *)p->response, sizeof h))
882	{	1197	{
883	prot_minor = p->prot_minor;	1198	// fast re-sync on source address changes, useful especially for tcp/ip
884
885	delete ictx; ictx = cctx;
886
887	iseqno.reset (ntohl (*(u32 *)&chg[CHG_SEQNO]) & 0x7fffffff); // at least 2**31 sequence numbers are valid
888
889	si = rsi;	1199	si = rsi;
890		1200
891	rekey.set (NOW + ::conf.rekey);	1201	slog (L_INFO, _("%s(%s): socket address changed to %s"),
892	keepalive.set (NOW + ::conf.keepalive);
893
894	// send queued packets
895	while (tap_packet *p = queue.get ())
896	{
897	send_data_packet (p);
898	delete p;
899	}
900
901	connectmode = conf->connectmode;
902
903	slog (L_INFO, _("%s(%s): %s connection established, protocol version %d.%d"),
904	conf->nodename, (const char *)rsi,	1202	conf->nodename, (const char *)si, (const char *)rsi);
905	strprotocol (protocol),
906	p->prot_major, p->prot_minor);
907
908	if (::conf.script_node_up)
909	run_script (run_script_cb (this, &connection::script_node_up), false);
910
911	break;
912	}	1203	}
913	else
914	slog (L_ERR, _("%s(%s): sent and received challenge do not match"),
915	conf->nodename, (const char *)rsi);
916	}	1204	}
917		1205
918	delete cctx;	1206	delete d;
		1207	break;
919	}	1208	}
920	}	1209	}
921	}
922		1210
923	send_reset (rsi);	1211	send_reset (rsi);
924	break;	1212	break;
925		1213
926	case vpn_packet::PT_DATA_COMPRESSED:
927	#if !ENABLE_COMPRESSION
928	send_reset (rsi);
929	break;
930	#endif
931
932	case vpn_packet::PT_DATA_UNCOMPRESSED:
933
934	if (ictx && octx)
935	{
936	vpndata_packet *p = (vpndata_packet *)pkt;
937
938	if (rsi == si)
939	{
940	if (!p->hmac_chk (ictx))
941	slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n"
942	"could be an attack, or just corruption or an synchronization error"),
943	conf->nodename, (const char *)rsi);
944	else
945	{
946	u32 seqno;
947	tap_packet *d = p->unpack (this, seqno);
948
949	if (iseqno.recv_ok (seqno))
950	{
951	vpn->tap->send (d);
952
953	if (p->dst () == 0) // re-broadcast
954	for (vpn::conns_vector::iterator i = vpn->conns.begin (); i != vpn->conns.end (); ++i)
955	{
956	connection *c = *i;
957
958	if (c->conf != THISNODE && c->conf != conf)
959	c->inject_data_packet (d);
960	}
961
962	delete d;
963
964	break;
965	}
966	}
967	}
968	else
969	slog (L_ERR, _("received data packet from unknown source %s"), (const char *)rsi);
970	}
971
972	send_reset (rsi);
973	break;
974
975	case vpn_packet::PT_CONNECT_REQ:	1214	case vpn_packet::PT_CONNECT_REQ:
976	if (ictx && octx && rsi == si && pkt->hmac_chk (ictx))	1215	if (ictx && octx && rsi == si && pkt->hmac_chk (ictx))
977	{	1216	{
978	connect_req_packet *p = (connect_req_packet *) pkt;	1217	connect_req_packet *p = (connect_req_packet *) pkt;
979		1218
980	assert (p->id > 0 && p->id <= vpn->conns.size ()); // hmac-auth does not mean we accept anything	1219	if (p->id > 0 && p->id <= vpn->conns.size ())
981	conf->protocols = p->protocols;	1220	{
982	connection *c = vpn->conns[p->id - 1];	1221	connection *c = vpn->conns[p->id - 1];
		1222	conf->protocols = p->protocols;
983		1223
984	slog (L_TRACE, "<<%d PT_CONNECT_REQ(%d) [%d]\n",	1224	slog (L_TRACE, "<<%d PT_CONNECT_REQ(%d) [%d]",
985	conf->id, p->id, c->ictx && c->octx);	1225	conf->id, p->id, c->ictx && c->octx);
986		1226
987	if (c->ictx && c->octx)	1227	if (c->ictx && c->octx)
988	{	1228	{
989	// send connect_info packets to both sides, in case one is	1229	// send connect_info packets to both sides, in case one is
990	// behind a nat firewall (or both ;)	1230	// behind a nat firewall (or both ;)
991	c->send_connect_info (conf->id, si, conf->protocols);	1231	c->send_connect_info (conf->id, si, conf->protocols);
992	send_connect_info (c->conf->id, c->si, c->conf->protocols);	1232	send_connect_info (c->conf->id, c->si, c->conf->protocols);
		1233	}
		1234	else
		1235	c->establish_connection ();
993	}	1236	}
		1237	else
		1238	slog (L_WARN,
		1239	_("received authenticated connection request from unknown node #%d, config file mismatch?"),
		1240	p->id);
994	}	1241	}
995		1242
996	break;	1243	break;
997		1244
998	case vpn_packet::PT_CONNECT_INFO:	1245	case vpn_packet::PT_CONNECT_INFO:
999	if (ictx && octx && rsi == si && pkt->hmac_chk (ictx))	1246	if (ictx && octx && rsi == si && pkt->hmac_chk (ictx))
1000	{	1247	{
1001	connect_info_packet *p = (connect_info_packet *) pkt;	1248	connect_info_packet *p = (connect_info_packet *)pkt;
1002		1249
1003	assert (p->id > 0 && p->id <= vpn->conns.size ()); // hmac-auth does not mean we accept anything	1250	if (p->id > 0 && p->id <= vpn->conns.size ())
1004	conf->protocols = p->protocols;	1251	{
1005	connection *c = vpn->conns[p->id - 1];	1252	connection *c = vpn->conns[p->id - 1];
1006		1253
		1254	c->conf->protocols = p->protocols;
		1255	protocol = best_protocol (c->conf->protocols & THISNODE->protocols & p->si.supported_protocols (c->conf));
		1256	p->si.upgrade_protocol (protocol, c->conf);
		1257
1007	slog (L_TRACE, "<<%d PT_CONNECT_INFO(%d,%s) (%d)",	1258	slog (L_TRACE, "<<%d PT_CONNECT_INFO(%d,%s) (%d)",
1008	conf->id, p->id, (const char *)p->si, !c->ictx && !c->octx);	1259	conf->id, p->id, (const char *)p->si, !c->ictx && !c->octx);
1009		1260
		1261	const sockinfo &dsi = forward_si (p->si);
		1262
		1263	if (dsi.valid ())
1010	c->send_auth_request (p->si, true);	1264	c->send_auth_request (dsi, true);
		1265	}
		1266	else
		1267	slog (L_WARN,
		1268	_("received authenticated connection request from unknown node #%d, config file mismatch?"),
		1269	p->id);
1011	}	1270	}
1012		1271
1013	break;	1272	break;
1014		1273
1015	default:	1274	default:
1016	send_reset (rsi);	1275	send_reset (rsi);
1017	break;	1276	break;
1018
1019	}	1277	}
1020	}	1278	}
1021		1279
1022	void connection::keepalive_cb (tstamp &ts)	1280	inline void
		1281	connection::keepalive_cb (ev::timer &w, int revents)
1023	{	1282	{
1024	if (NOW >= last_activity + ::conf.keepalive + 30)	1283	if (ev_now () >= last_activity + ::conf.keepalive + 30)
1025	{	1284	{
1026	reset_connection ();	1285	reset_connection ();
1027	establish_connection ();	1286	establish_connection ();
1028	}	1287	}
1029	else if (NOW < last_activity + ::conf.keepalive)	1288	else if (ev_now () < last_activity + ::conf.keepalive)
1030	ts = last_activity + ::conf.keepalive;	1289	w.start (last_activity + ::conf.keepalive - ev::now ());
1031	else if (conf->connectmode != conf_node::C_ONDEMAND	1290	else if (conf->connectmode != conf_node::C_ONDEMAND
1032	|| THISNODE->connectmode != conf_node::C_ONDEMAND)	1291	|| THISNODE->connectmode != conf_node::C_ONDEMAND)
1033	{	1292	{
1034	send_ping (si);	1293	send_ping (si);
1035	ts = NOW + 5;	1294	w.start (5);
1036	}	1295	}
		1296	else if (ev_now () < last_activity + ::conf.keepalive + 10)
		1297	// hold ondemand connections implicitly a few seconds longer
		1298	// should delete octx, though, or something like that ;)
		1299	w.start (last_activity + ::conf.keepalive + 10 - ev::now ());
1037	else	1300	else
1038	reset_connection ();	1301	reset_connection ();
1039	}	1302	}
1040		1303
1041	void connection::connect_request (int id)	1304	void connection::send_connect_request (int id)
1042	{	1305	{
1043	connect_req_packet *p = new connect_req_packet (conf->id, id, conf->protocols);	1306	connect_req_packet *p = new connect_req_packet (conf->id, id, conf->protocols);
1044		1307
1045	slog (L_TRACE, ">>%d PT_CONNECT_REQ(%d)", conf->id, id);	1308	slog (L_TRACE, ">>%d PT_CONNECT_REQ(%d)", conf->id, id);
1046	p->hmac_set (octx);	1309	p->hmac_set (octx);
1047	send_vpn_packet (p, si);	1310	send_vpn_packet (p, si);
1048		1311
1049	delete p;	1312	delete p;
1050	}	1313	}
1051		1314
		1315	void connection::script_init_env (const char *ext)
		1316	{
		1317	char *env;
		1318	asprintf (&env, "IFUPDATA%s=%s", ext, conf->if_up_data); putenv (env);
		1319	asprintf (&env, "NODENAME%s=%s", ext, conf->nodename); putenv (env);
		1320	asprintf (&env, "MAC%s=%02x:%02x:%02x:%02x:%02x:%02x", ext,
		1321	0xfe, 0xfd, 0x80, 0x00, conf->id >> 8,
		1322	conf->id & 0xff); putenv (env);
		1323	}
		1324
1052	void connection::script_node ()	1325	void connection::script_init_connect_env ()
1053	{	1326	{
1054	vpn->script_if_up (0);	1327	vpn->script_init_env ();
1055		1328
1056	char *env;	1329	char *env;
1057	asprintf (&env, "DESTID=%d", conf->id); putenv (env);	1330	asprintf (&env, "DESTID=%d", conf->id); putenv (env);
1058	asprintf (&env, "DESTNODE=%s", conf->nodename); putenv (env);	1331	asprintf (&env, "DESTNODE=%s", conf->nodename); putenv (env);
1059	asprintf (&env, "DESTIP=%s", si.ntoa ()); putenv (env);	1332	asprintf (&env, "DESTIP=%s", si.ntoa ()); putenv (env);
1060	asprintf (&env, "DESTPORT=%d", ntohs (si.port)); putenv (env);	1333	asprintf (&env, "DESTPORT=%d", ntohs (si.port)); putenv (env);
1061	}	1334	}
1062		1335
		1336	inline const char *
1063	const char *connection::script_node_up (int)	1337	connection::script_node_up ()
1064	{	1338	{
1065	script_node ();	1339	script_init_connect_env ();
1066		1340
1067	putenv ("STATE=up");	1341	putenv ((char *)"STATE=up");
1068		1342
		1343	char *filename;
		1344	asprintf (&filename,
		1345	"%s/%s",
		1346	confbase,
1069	return ::conf.script_node_up ? ::conf.script_node_up : "node-up";	1347	::conf.script_node_up ? ::conf.script_node_up : "node-up");
1070	}
1071		1348
		1349	return filename;
		1350	}
		1351
		1352	inline const char *
1072	const char *connection::script_node_down (int)	1353	connection::script_node_down ()
1073	{	1354	{
1074	script_node ();	1355	script_init_connect_env ();
1075		1356
1076	putenv ("STATE=down");	1357	putenv ((char *)"STATE=down");
1077		1358
1078	return ::conf.script_node_up ? ::conf.script_node_down : "node-down";	1359	char *filename;
1079	}	1360	asprintf (&filename,
		1361	"%s/%s",
		1362	confbase,
		1363	::conf.script_node_down ? ::conf.script_node_down : "node-down");
1080		1364
1081	// send a vpn packet out to other hosts	1365	return filename;
1082	void
1083	connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1084	{
1085	if (protocol & PROT_IPv4)
1086	vpn->send_ipv4_packet (pkt, si, tos);
1087	else
1088	vpn->send_udpv4_packet (pkt, si, tos);
1089	}	1366	}
1090		1367
1091	connection::connection(struct vpn *vpn_)	1368	connection::connection (struct vpn *vpn, conf_node *conf)
1092	: vpn(vpn_)	1369	: vpn(vpn), conf(conf),
1093	, rekey (this, &connection::rekey_cb)	1370	#if ENABLE_DNS
1094	, keepalive (this, &connection::keepalive_cb)	1371	dns (0),
		1372	#endif
		1373	data_queue(conf->max_ttl, conf->max_queue + 1),
		1374	vpn_queue(conf->max_ttl, conf->max_queue + 1)
		1375	{
		1376	rekey .set<connection, &connection::rekey_cb > (this);
		1377	keepalive .set<connection, &connection::keepalive_cb > (this);
1095	, establish_connection (this, &connection::establish_connection_cb)	1378	establish_connection.set<connection, &connection::establish_connection_cb> (this);
1096	{	1379
		1380	last_establish_attempt = 0.;
1097	octx = ictx = 0;	1381	octx = ictx = 0;
1098	retry_cnt = 0;
1099		1382
1100	connectmode = conf_node::C_ALWAYS; // initial setting	1383	if (!conf->protocols) // make sure some protocol is enabled
		1384	conf->protocols = PROT_UDPv4;
		1385
		1386	connectmode = conf->connectmode;
		1387
		1388	// queue a dummy packet to force an initial connection attempt
		1389	if (connectmode != conf_node::C_ALWAYS && connectmode != conf_node::C_DISABLED)
		1390	vpn_queue.put (new net_packet);
		1391
1101	reset_connection ();	1392	reset_connection ();
1102	}	1393	}
1103		1394
1104	connection::~connection ()	1395	connection::~connection ()
1105	{	1396	{

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