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"

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 ikm[IKM_SIZE]; // used as additional keying material for both sides
  u8 pad[
    (RSABITS >> 3)
    - 41 // OAEP
    - sizeof (u32) // seqno
    - AUTH_SIZE
    - MAC_KEYSIZE
    - CIPHER_KEYSIZE
    - HKDF_SALT
    - IKM_SIZE
    - 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;

  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:	1.37
Committed:	Tue Jul 16 16:44:36 2013 UTC (10 years, 10 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.36:	+62 -8 lines
Log Message:	3.x
#	User	Rev	Content
1	pcg	1.1	/*
2			connection.h -- header for connection.C
3	root	1.37	Copyright (C) 2003-2008,2013 Marc Lehmann <gvpe@schmorp.de>
4	pcg	1.1
5	pcg	1.18	This file is part of GVPE.
6
7	pcg	1.32	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	pcg	1.1	*/
31
32	pcg	1.22	#ifndef GVPE_CONNECTION_H__
33			#define GVPE_CONNECTION_H__
34	pcg	1.1
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	root	1.37	#include "curve25519.h"
43	pcg	1.1
44			struct vpn;
45
46			// called after HUP etc. to (re-)initialize global data structures
47			void connection_init ();
48
49	root	1.37	typedef curve25519_key ecdh_key;
50
51			struct rsa_data
52			{
53			u32 seqno;
54			u8 auth_key[AUTH_SIZE];
55			u8 mac_key[MAC_KEYSIZE]; // used to generate hmac key
56			u8 cipher_key[CIPHER_KEYSIZE]; // used to generate cipher key
57			u8 hkdf_salt[HKDF_SALT]; // used as hkdf salt
58			u8 ikm[IKM_SIZE]; // used as additional keying material for both sides
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			- IKM_SIZE
68			- 3 // struct alignment...
69			];
70			};
71
72			struct auth_data
73			{
74			rsa_data rsa;
75			ecdh_key ecdh;
76			};
77
78			typedef u8 rsa_crypt[RSA_KEYLEN]; // encrypted challenge
79
80			struct auth_encr
81	pcg	1.29	{
82	root	1.37	rsa_crypt rsa;
83			ecdh_key ecdh;
84	pcg	1.1	};
85
86	root	1.37	typedef u8 auth_mac[AUTH_SIZE];
87
88			struct auth_response
89			{
90			auth_mac mac;
91			ecdh_key ecdh;
92			};
93	pcg	1.1
94			////////////////////////////////////////////////////////////////////////////////////////
95
96			struct crypto_ctx;
97
98	pcg	1.13	struct hmac_packet : net_packet
99	pcg	1.1	{
100			u8 hmac[HMACLENGTH]; // each and every packet has a hmac field, but that is not (yet) checked everywhere
101
102			void hmac_set (crypto_ctx * ctx);
103			bool hmac_chk (crypto_ctx * ctx);
104
105			private:
106			static unsigned char hmac_digest[EVP_MAX_MD_SIZE];
107
108			void hmac_gen (crypto_ctx * ctx);
109			};
110
111			struct vpn_packet : hmac_packet
112	pcg	1.29	{
113			enum ptype
114	pcg	1.1	{
115	pcg	1.29	PT_RESET = 0,
116			PT_DATA_UNCOMPRESSED,
117			PT_DATA_COMPRESSED,
118			PT_PING, PT_PONG, // wasting namespace space? ;)
119			PT_AUTH_REQ, // authentification request
120			PT_AUTH_RES, // authentification response
121			PT_CONNECT_REQ, // want other node to contact me
122			PT_CONNECT_INFO, // request connection to some node
123	pcg	1.31	PT_DATA_BRIDGED, // uncompressed packet with foreign mac pot. larger than path mtu (NYI)
124	pcg	1.29	PT_MAX
125	pcg	1.1	};
126
127	pcg	1.29	u8 type;
128			u8 srcdst, src1, dst1;
129
130			void set_hdr (ptype type_, unsigned int dst);
131
132			unsigned int src () const
133			{
134			return src1 \| ((srcdst >> 4) << 8);
135			}
136
137			unsigned int dst () const
138			{
139			return dst1 \| ((srcdst & 0xf) << 8);
140			}
141
142			ptype typ () const
143			{
144			return (ptype) type;
145			}
146			};
147
148	pcg	1.1	////////////////////////////////////////////////////////////////////////////////////////
149
150			// a very simple fifo pkt-queue
151			class pkt_queue
152	pcg	1.29	{
153			int i, j;
154	pcg	1.30	int max_queue;
155			double max_ttl;
156
157			struct pkt {
158			ev_tstamp tstamp;
159			net_packet *pkt;
160			} *queue;
161
162			void expire_cb (ev::timer &w, int revents); ev::timer expire;
163	pcg	1.1
164	pcg	1.29	public:
165	pcg	1.1
166	pcg	1.29	void put (net_packet *p);
167			net_packet *get ();
168	pcg	1.1
169	pcg	1.30	bool empty ()
170			{
171			return i == j;
172			}
173
174			pkt_queue (double max_ttl, int max_queue);
175	pcg	1.29	~pkt_queue ();
176			};
177	pcg	1.1
178	pcg	1.14	enum
179	pcg	1.29	{
180			FEATURE_COMPRESSION = 0x01,
181			FEATURE_ROHC = 0x02,
182			FEATURE_BRIDGING = 0x04,
183			};
184	pcg	1.14
185	pcg	1.1	struct connection
186	pcg	1.29	{
187			conf_node *conf;
188			struct vpn *vpn;
189	pcg	1.1
190	pcg	1.29	sockinfo si; // the current(!) destination ip to send packets to
191			int retry_cnt;
192	pcg	1.1
193	pcg	1.29	tstamp last_activity; // time of last packet received
194	root	1.35	tstamp last_establish_attempt;
195	pcg	1.33	//tstamp last_si_change; // time we last changed the socket address
196	pcg	1.1
197	pcg	1.29	u32 oseqno;
198			sliding_window iseqno;
199	pcg	1.1
200	pcg	1.29	u8 protocol;
201			u8 features;
202	pcg	1.33	bool is_direct; // current connection (si) is direct?
203	pcg	1.1
204	pcg	1.29	pkt_queue data_queue, vpn_queue;
205	pcg	1.1
206	pcg	1.29	crypto_ctx octx, ictx;
207	pcg	1.1
208	root	1.37	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	pcg	1.15	#if ENABLE_DNS
226	pcg	1.29	struct dns_connection *dns;
227	pcg	1.15	#endif
228
229	pcg	1.29	enum conf_node::connectmode connectmode;
230			u8 prot_minor; // minor number of other side
231	pcg	1.1
232	pcg	1.29	void reset_si ();
233			const sockinfo &forward_si (const sockinfo &si) const;
234	pcg	1.1
235	pcg	1.29	void shutdown ();
236	root	1.37	void connection_established (const sockinfo &rsi);
237	pcg	1.29	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	root	1.37	void send_auth_response (const sockinfo &si);
246	pcg	1.29	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	pcg	1.31	void post_inject_queue ();
252			void inject_data_packet (tap_packet *pkt);
253	pcg	1.29	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	pcg	1.34	const char *script_node_change ();
262	pcg	1.29	const char *script_node_down ();
263	pcg	1.1
264	pcg	1.29	void dump_status ();
265	pcg	1.1
266	pcg	1.29	connection (struct vpn vpn, conf_node conf);
267			~connection ();
268			};
269	pcg	1.1
270			#endif
271