gvpe/src/connection.h

/*
    connection.h -- header for connection.C
    Copyright (C) 2003-2008,2013 Marc Lehmann <gvpe@schmorp.de>
 
    This file is part of GVPE.

    GVPE is free software; you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by the
    Free Software Foundation; either version 3 of the License, or (at your
    option) any later version.
   
    This program is distributed in the hope that it will be useful, but
    WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
    Public License for more details.
   
    You should have received a copy of the GNU General Public License along
    with this program; if not, see <http://www.gnu.org/licenses/>.
   
    Additional permission under GNU GPL version 3 section 7
   
    If you modify this Program, or any covered work, by linking or
    combining it with the OpenSSL project's OpenSSL library (or a modified
    version of that library), containing parts covered by the terms of the
    OpenSSL or SSLeay licenses, the licensors of this Program grant you
    additional permission to convey the resulting work.  Corresponding
    Source for a non-source form of such a combination shall include the
    source code for the parts of OpenSSL used as well as that of the
    covered work.
*/

#ifndef GVPE_CONNECTION_H__
#define GVPE_CONNECTION_H__

#include <openssl/hmac.h>

#include "global.h"
#include "conf.h"
#include "sockinfo.h"
#include "util.h"
#include "device.h"
#include "curve25519.h"
#include "iv_gen.h"

struct vpn;

// called after HUP etc. to (re-)initialize global data structures
void connection_init ();

typedef curve25519_key ecdh_key;

struct rsa_data
{
  u32 seqno;
  u8 auth_key[AUTH_SIZE];
  u8 mac_key[MAC_KEYSIZE]; // used to generate hmac key
  u8 cipher_key[CIPHER_KEYSIZE]; // used to generate cipher key
  u8 hkdf_salt[HKDF_SALT]; // used as hkdf salt
  u8 pad[
    (RSABITS >> 3)
    - 41 // OAEP
    - sizeof (u32) // seqno
    - AUTH_SIZE
    - MAC_KEYSIZE
    - CIPHER_KEYSIZE
    - HKDF_SALT
    - 3 // struct alignment...
  ];
};

struct auth_data
{
  rsa_data rsa;
  ecdh_key ecdh;
};

typedef u8 rsa_crypt[RSA_KEYLEN]; // encrypted challenge

struct auth_encr
{
  rsa_crypt rsa;
  ecdh_key ecdh;
};

typedef u8 auth_mac[AUTH_SIZE];

struct auth_response
{
  auth_mac mac;
  ecdh_key ecdh;
};

////////////////////////////////////////////////////////////////////////////////////////

struct crypto_ctx;

struct hmac_packet : net_packet
{
  u8 hmac[HMACLENGTH];          // each and every packet has a hmac field, but that is not (yet) checked everywhere

  void hmac_set (crypto_ctx * ctx);
  bool hmac_chk (crypto_ctx * ctx);

private:
  static unsigned char hmac_digest[EVP_MAX_MD_SIZE];

  void hmac_gen (crypto_ctx * ctx);
};

struct vpn_packet : hmac_packet
{
  enum ptype
  {
    PT_RESET = 0,
    PT_DATA_UNCOMPRESSED,
    PT_DATA_COMPRESSED,
    PT_PING, PT_PONG,   // wasting namespace space? ;)
    PT_AUTH_REQ,        // authentification request
    PT_AUTH_RES,        // authentification response
    PT_CONNECT_REQ,     // want other node to contact me
    PT_CONNECT_INFO,    // request connection to some node
    PT_DATA_BRIDGED,    // uncompressed packet with foreign mac pot. larger than path mtu (NYI)
    PT_MAX
  };

  u8 type;
  u8 srcdst, src1, dst1;

  void set_hdr (ptype type_, unsigned int dst);

  unsigned int src () const
  {
    return src1 | ((srcdst >> 4) << 8);
  }

  unsigned int dst () const
  {
    return dst1 | ((srcdst & 0xf) << 8);
  }

  ptype typ () const
  {
    return (ptype) type;
  }
};

////////////////////////////////////////////////////////////////////////////////////////

// a very simple fifo pkt-queue
class pkt_queue
{
  int i, j;
  int max_queue;
  double max_ttl;

  struct pkt {
    ev_tstamp tstamp;
    net_packet *pkt;
  } *queue;

  void expire_cb (ev::timer &w, int revents); ev::timer expire;

public:

  void put (net_packet *p);
  net_packet *get ();

  bool empty ()
  {
    return i == j;
  }

  pkt_queue (double max_ttl, int max_queue);
  ~pkt_queue ();
};

enum
{
  FEATURE_COMPRESSION = 0x01,
  FEATURE_ROHC        = 0x02,
  FEATURE_BRIDGING    = 0x04,
};

struct connection
{
  conf_node *conf;
  struct vpn *vpn;

  sockinfo si; // the current(!) destination ip to send packets to
  int retry_cnt;

  tstamp last_activity; // time of last packet received
  tstamp last_establish_attempt;
  //tstamp last_si_change; // time we last changed the socket address

  u32 oseqno;
  sliding_window iseqno;

  u8 protocol;
  u8 features;
  bool is_direct; // current connection (si) is direct?

  pkt_queue data_queue, vpn_queue;

  crypto_ctx *octx, *ictx;
  iv_gen oiv; // generator for random byte prefix

  void generate_auth_data ();

  ev_tstamp auth_expire; // when the snd_* and *_ecdh values expire

  // send auth data - used for octx
  auth_data snd_auth;
  auth_mac snd_auth_mac; // expected response mac
  ecdh_key snd_ecdh_a; // the secret ecdh key we used for our request
  ecdh_key snd_ecdh_b; // the public ecdh key we received in the response
  bool have_snd_auth; // received response for our req

  // receive auth data - used for ictx
  auth_data rcv_auth;
  ecdh_key rcv_ecdh_a; // the secret ecdh key we used for our response
  ecdh_key rcv_ecdh_b; // the public ecdh key we sent in our response
  bool have_rcv_auth; // received auth from other side

#if ENABLE_DNS
  struct dns_connection *dns;
#endif

  enum conf_node::connectmode connectmode;
  u8 prot_minor; // minor number of other side

  void reset_si ();
  const sockinfo &forward_si (const sockinfo &si) const;

  void shutdown ();
  void connection_established (const sockinfo &rsi);
  void reset_connection ();

  void establish_connection_cb (ev::timer &w, int revents); ev::timer establish_connection;
  void rekey_cb (ev::timer &w, int revents); ev::timer rekey; // next rekying (actually current reset + reestablishing)
  void keepalive_cb (ev::timer &w, int revents); ev::timer keepalive; // next keepalive probe

  void send_connect_request (int id);
  void send_auth_request (const sockinfo &si, bool initiate);
  void send_auth_response (const sockinfo &si);
  void send_connect_info (int rid, const sockinfo &rsi, u8 rprotocols);
  void send_reset (const sockinfo &dsi);
  void send_ping (const sockinfo &dsi, u8 pong = 0);
  void send_data_packet (tap_packet *pkt);

  void post_inject_queue ();
  void inject_data_packet (tap_packet *pkt);
  void inject_vpn_packet (vpn_packet *pkt, int tos = 0); // for forwarding

  void recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi);
  void send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos = 0);

  void script_init_env (const char *ext);
  void script_init_connect_env ();
  const char *script_node_up ();
  const char *script_node_change ();
  const char *script_node_down ();

  void dump_status ();

  connection (struct vpn *vpn, conf_node *conf);
  ~connection ();
};

#endif

Revision:	1.38
Committed:	Thu Jul 18 13:35:16 2013 UTC (10 years, 10 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.37:	+2 -2 lines
Log Message:	* empty log message *
#	Content
1	/*
2	connection.h -- header for connection.C
3	Copyright (C) 2003-2008,2013 Marc Lehmann <gvpe@schmorp.de>
4
5	This file is part of GVPE.
6
7	GVPE is free software; you can redistribute it and/or modify it
8	under the terms of the GNU General Public License as published by the
9	Free Software Foundation; either version 3 of the License, or (at your
10	option) any later version.
11
12	This program is distributed in the hope that it will be useful, but
13	WITHOUT ANY WARRANTY; without even the implied warranty of
14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
15	Public License for more details.
16
17	You should have received a copy of the GNU General Public License along
18	with this program; if not, see <http://www.gnu.org/licenses/>.
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.
30	*/
31
32	#ifndef GVPE_CONNECTION_H__
33	#define GVPE_CONNECTION_H__
34
35	#include <openssl/hmac.h>
36
37	#include "global.h"
38	#include "conf.h"
39	#include "sockinfo.h"
40	#include "util.h"
41	#include "device.h"
42	#include "curve25519.h"
43	#include "iv_gen.h"
44
45	struct vpn;
46
47	// called after HUP etc. to (re-)initialize global data structures
48	void connection_init ();
49
50	typedef curve25519_key ecdh_key;
51
52	struct rsa_data
53	{
54	u32 seqno;
55	u8 auth_key[AUTH_SIZE];
56	u8 mac_key[MAC_KEYSIZE]; // used to generate hmac key
57	u8 cipher_key[CIPHER_KEYSIZE]; // used to generate cipher key
58	u8 hkdf_salt[HKDF_SALT]; // used as hkdf salt
59	u8 pad[
60	(RSABITS >> 3)
61	- 41 // OAEP
62	- sizeof (u32) // seqno
63	- AUTH_SIZE
64	- MAC_KEYSIZE
65	- CIPHER_KEYSIZE
66	- HKDF_SALT
67	- 3 // struct alignment...
68	];
69	};
70
71	struct auth_data
72	{
73	rsa_data rsa;
74	ecdh_key ecdh;
75	};
76
77	typedef u8 rsa_crypt[RSA_KEYLEN]; // encrypted challenge
78
79	struct auth_encr
80	{
81	rsa_crypt rsa;
82	ecdh_key ecdh;
83	};
84
85	typedef u8 auth_mac[AUTH_SIZE];
86
87	struct auth_response
88	{
89	auth_mac mac;
90	ecdh_key ecdh;
91	};
92
93	////////////////////////////////////////////////////////////////////////////////////////
94
95	struct crypto_ctx;
96
97	struct hmac_packet : net_packet
98	{
99	u8 hmac[HMACLENGTH]; // each and every packet has a hmac field, but that is not (yet) checked everywhere
100
101	void hmac_set (crypto_ctx * ctx);
102	bool hmac_chk (crypto_ctx * ctx);
103
104	private:
105	static unsigned char hmac_digest[EVP_MAX_MD_SIZE];
106
107	void hmac_gen (crypto_ctx * ctx);
108	};
109
110	struct vpn_packet : hmac_packet
111	{
112	enum ptype
113	{
114	PT_RESET = 0,
115	PT_DATA_UNCOMPRESSED,
116	PT_DATA_COMPRESSED,
117	PT_PING, PT_PONG, // wasting namespace space? ;)
118	PT_AUTH_REQ, // authentification request
119	PT_AUTH_RES, // authentification response
120	PT_CONNECT_REQ, // want other node to contact me
121	PT_CONNECT_INFO, // request connection to some node
122	PT_DATA_BRIDGED, // uncompressed packet with foreign mac pot. larger than path mtu (NYI)
123	PT_MAX
124	};
125
126	u8 type;
127	u8 srcdst, src1, dst1;
128
129	void set_hdr (ptype type_, unsigned int dst);
130
131	unsigned int src () const
132	{
133	return src1 \| ((srcdst >> 4) << 8);
134	}
135
136	unsigned int dst () const
137	{
138	return dst1 \| ((srcdst & 0xf) << 8);
139	}
140
141	ptype typ () const
142	{
143	return (ptype) type;
144	}
145	};
146
147	////////////////////////////////////////////////////////////////////////////////////////
148
149	// a very simple fifo pkt-queue
150	class pkt_queue
151	{
152	int i, j;
153	int max_queue;
154	double max_ttl;
155
156	struct pkt {
157	ev_tstamp tstamp;
158	net_packet *pkt;
159	} *queue;
160
161	void expire_cb (ev::timer &w, int revents); ev::timer expire;
162
163	public:
164
165	void put (net_packet *p);
166	net_packet *get ();
167
168	bool empty ()
169	{
170	return i == j;
171	}
172
173	pkt_queue (double max_ttl, int max_queue);
174	~pkt_queue ();
175	};
176
177	enum
178	{
179	FEATURE_COMPRESSION = 0x01,
180	FEATURE_ROHC = 0x02,
181	FEATURE_BRIDGING = 0x04,
182	};
183
184	struct connection
185	{
186	conf_node *conf;
187	struct vpn *vpn;
188
189	sockinfo si; // the current(!) destination ip to send packets to
190	int retry_cnt;
191
192	tstamp last_activity; // time of last packet received
193	tstamp last_establish_attempt;
194	//tstamp last_si_change; // time we last changed the socket address
195
196	u32 oseqno;
197	sliding_window iseqno;
198
199	u8 protocol;
200	u8 features;
201	bool is_direct; // current connection (si) is direct?
202
203	pkt_queue data_queue, vpn_queue;
204
205	crypto_ctx octx, ictx;
206	iv_gen oiv; // generator for random byte prefix
207
208	void generate_auth_data ();
209
210	ev_tstamp auth_expire; // when the snd_* and *_ecdh values expire
211
212	// send auth data - used for octx
213	auth_data snd_auth;
214	auth_mac snd_auth_mac; // expected response mac
215	ecdh_key snd_ecdh_a; // the secret ecdh key we used for our request
216	ecdh_key snd_ecdh_b; // the public ecdh key we received in the response
217	bool have_snd_auth; // received response for our req
218
219	// receive auth data - used for ictx
220	auth_data rcv_auth;
221	ecdh_key rcv_ecdh_a; // the secret ecdh key we used for our response
222	ecdh_key rcv_ecdh_b; // the public ecdh key we sent in our response
223	bool have_rcv_auth; // received auth from other side
224
225	#if ENABLE_DNS
226	struct dns_connection *dns;
227	#endif
228
229	enum conf_node::connectmode connectmode;
230	u8 prot_minor; // minor number of other side
231
232	void reset_si ();
233	const sockinfo &forward_si (const sockinfo &si) const;
234
235	void shutdown ();
236	void connection_established (const sockinfo &rsi);
237	void reset_connection ();
238
239	void establish_connection_cb (ev::timer &w, int revents); ev::timer establish_connection;
240	void rekey_cb (ev::timer &w, int revents); ev::timer rekey; // next rekying (actually current reset + reestablishing)
241	void keepalive_cb (ev::timer &w, int revents); ev::timer keepalive; // next keepalive probe
242
243	void send_connect_request (int id);
244	void send_auth_request (const sockinfo &si, bool initiate);
245	void send_auth_response (const sockinfo &si);
246	void send_connect_info (int rid, const sockinfo &rsi, u8 rprotocols);
247	void send_reset (const sockinfo &dsi);
248	void send_ping (const sockinfo &dsi, u8 pong = 0);
249	void send_data_packet (tap_packet *pkt);
250
251	void post_inject_queue ();
252	void inject_data_packet (tap_packet *pkt);
253	void inject_vpn_packet (vpn_packet *pkt, int tos = 0); // for forwarding
254
255	void recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi);
256	void send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos = 0);
257
258	void script_init_env (const char *ext);
259	void script_init_connect_env ();
260	const char *script_node_up ();
261	const char *script_node_change ();
262	const char *script_node_down ();
263
264	void dump_status ();
265
266	connection (struct vpn vpn, conf_node conf);
267	~connection ();
268	};
269
270	#endif
271