1 /**
2  * @file
3  * Network Point to Point Protocol over Layer 2 Tunneling Protocol header file.
4  *
5  */
6 
7 /*
8  * Redistribution and use in source and binary forms, with or without modification,
9  * are permitted provided that the following conditions are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright notice,
12  *    this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright notice,
14  *    this list of conditions and the following disclaimer in the documentation
15  *    and/or other materials provided with the distribution.
16  * 3. The name of the author may not be used to endorse or promote products
17  *    derived from this software without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
20  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
21  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
22  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
23  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
24  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
27  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
28  * OF SUCH DAMAGE.
29  *
30  * This file is part of the lwIP TCP/IP stack.
31  *
32  */
33 
34 #include "netif/ppp/ppp_opts.h"
35 #if PPP_SUPPORT && PPPOL2TP_SUPPORT /* don't build if not configured for use in lwipopts.h */
36 
37 #ifndef PPPOL2TP_H
38 #define PPPOL2TP_H
39 
40 #include "ppp.h"
41 
42 /* Timeout */
43 #define PPPOL2TP_CONTROL_TIMEOUT         (5*1000)  /* base for quick timeout calculation */
44 #define PPPOL2TP_SLOW_RETRY              (60*1000) /* persistent retry interval */
45 
46 #define PPPOL2TP_MAXSCCRQ                4         /* retry SCCRQ four times (quickly) */
47 #define PPPOL2TP_MAXICRQ                 4         /* retry IRCQ four times */
48 #define PPPOL2TP_MAXICCN                 4         /* retry ICCN four times */
49 
50 /* L2TP header flags */
51 #define PPPOL2TP_HEADERFLAG_CONTROL      0x8000
52 #define PPPOL2TP_HEADERFLAG_LENGTH       0x4000
53 #define PPPOL2TP_HEADERFLAG_SEQUENCE     0x0800
54 #define PPPOL2TP_HEADERFLAG_OFFSET       0x0200
55 #define PPPOL2TP_HEADERFLAG_PRIORITY     0x0100
56 #define PPPOL2TP_HEADERFLAG_VERSION      0x0002
57 
58 /* Mandatory bits for control: Control, Length, Sequence, Version 2 */
59 #define PPPOL2TP_HEADERFLAG_CONTROL_MANDATORY     (PPPOL2TP_HEADERFLAG_CONTROL|PPPOL2TP_HEADERFLAG_LENGTH|PPPOL2TP_HEADERFLAG_SEQUENCE|PPPOL2TP_HEADERFLAG_VERSION)
60 /* Forbidden bits for control: Offset, Priority */
61 #define PPPOL2TP_HEADERFLAG_CONTROL_FORBIDDEN     (PPPOL2TP_HEADERFLAG_OFFSET|PPPOL2TP_HEADERFLAG_PRIORITY)
62 
63 /* Mandatory bits for data: Version 2 */
64 #define PPPOL2TP_HEADERFLAG_DATA_MANDATORY        (PPPOL2TP_HEADERFLAG_VERSION)
65 
66 /* AVP (Attribute Value Pair) header */
67 #define PPPOL2TP_AVPHEADERFLAG_MANDATORY  0x8000
68 #define PPPOL2TP_AVPHEADERFLAG_HIDDEN     0x4000
69 #define PPPOL2TP_AVPHEADERFLAG_LENGTHMASK 0x03ff
70 
71 /* -- AVP - Message type */
72 #define PPPOL2TP_AVPTYPE_MESSAGE      0 /* Message type */
73 
74 /* Control Connection Management */
75 #define PPPOL2TP_MESSAGETYPE_SCCRQ    1 /* Start Control Connection Request */
76 #define PPPOL2TP_MESSAGETYPE_SCCRP    2 /* Start Control Connection Reply */
77 #define PPPOL2TP_MESSAGETYPE_SCCCN    3 /* Start Control Connection Connected */
78 #define PPPOL2TP_MESSAGETYPE_STOPCCN  4 /* Stop Control Connection Notification */
79 #define PPPOL2TP_MESSAGETYPE_HELLO    6 /* Hello */
80 /* Call Management */
81 #define PPPOL2TP_MESSAGETYPE_OCRQ     7 /* Outgoing Call Request */
82 #define PPPOL2TP_MESSAGETYPE_OCRP     8 /* Outgoing Call Reply */
83 #define PPPOL2TP_MESSAGETYPE_OCCN     9 /* Outgoing Call Connected */
84 #define PPPOL2TP_MESSAGETYPE_ICRQ    10 /* Incoming Call Request */
85 #define PPPOL2TP_MESSAGETYPE_ICRP    11 /* Incoming Call Reply */
86 #define PPPOL2TP_MESSAGETYPE_ICCN    12 /* Incoming Call Connected */
87 #define PPPOL2TP_MESSAGETYPE_CDN     14 /* Call Disconnect Notify */
88 /* Error reporting */
89 #define PPPOL2TP_MESSAGETYPE_WEN     15 /* WAN Error Notify */
90 /* PPP Session Control */
91 #define PPPOL2TP_MESSAGETYPE_SLI     16 /* Set Link Info */
92 
93 /* -- AVP - Result code */
94 #define PPPOL2TP_AVPTYPE_RESULTCODE   1 /* Result code */
95 #define PPPOL2TP_RESULTCODE           1 /* General request to clear control connection */
96 
97 /* -- AVP - Protocol version (!= L2TP Header version) */
98 #define PPPOL2TP_AVPTYPE_VERSION      2
99 #define PPPOL2TP_VERSION         0x0100 /* L2TP Protocol version 1, revision 0 */
100 
101 /* -- AVP - Framing capabilities */
102 #define PPPOL2TP_AVPTYPE_FRAMINGCAPABILITIES           3 /* Bearer capabilities */
103 #define PPPOL2TP_FRAMINGCAPABILITIES          0x00000003 /* Async + Sync framing */
104 
105 /* -- AVP - Bearer capabilities */
106 #define PPPOL2TP_AVPTYPE_BEARERCAPABILITIES           4 /* Bearer capabilities */
107 #define PPPOL2TP_BEARERCAPABILITIES          0x00000003 /* Analog + Digital Access */
108 
109 /* -- AVP - Tie breaker */
110 #define PPPOL2TP_AVPTYPE_TIEBREAKER   5
111 
112 /* -- AVP - Host name */
113 #define PPPOL2TP_AVPTYPE_HOSTNAME     7 /* Host name */
114 #define PPPOL2TP_HOSTNAME        "lwIP" /* FIXME: make it configurable */
115 
116 /* -- AVP - Vendor name */
117 #define PPPOL2TP_AVPTYPE_VENDORNAME   8 /* Vendor name */
118 #define PPPOL2TP_VENDORNAME      "lwIP" /* FIXME: make it configurable */
119 
120 /* -- AVP - Assign tunnel ID */
121 #define PPPOL2TP_AVPTYPE_TUNNELID     9 /* Assign Tunnel ID */
122 
123 /* -- AVP - Receive window size */
124 #define PPPOL2TP_AVPTYPE_RECEIVEWINDOWSIZE  10 /* Receive window size */
125 #define PPPOL2TP_RECEIVEWINDOWSIZE           8 /* FIXME: make it configurable */
126 
127 /* -- AVP - Challenge */
128 #define PPPOL2TP_AVPTYPE_CHALLENGE   11 /* Challenge */
129 
130 /* -- AVP - Cause code */
131 #define PPPOL2TP_AVPTYPE_CAUSECODE   12 /* Cause code*/
132 
133 /* -- AVP - Challenge response */
134 #define PPPOL2TP_AVPTYPE_CHALLENGERESPONSE   13 /* Challenge response */
135 #define PPPOL2TP_AVPTYPE_CHALLENGERESPONSE_SIZE  16
136 
137 /* -- AVP - Assign session ID */
138 #define PPPOL2TP_AVPTYPE_SESSIONID   14 /* Assign Session ID */
139 
140 /* -- AVP - Call serial number */
141 #define PPPOL2TP_AVPTYPE_CALLSERIALNUMBER   15 /* Call Serial Number */
142 
143 /* -- AVP - Framing type */
144 #define PPPOL2TP_AVPTYPE_FRAMINGTYPE         19 /* Framing Type */
145 #define PPPOL2TP_FRAMINGTYPE         0x00000001 /* Sync framing */
146 
147 /* -- AVP - TX Connect Speed */
148 #define PPPOL2TP_AVPTYPE_TXCONNECTSPEED      24 /* TX Connect Speed */
149 #define PPPOL2TP_TXCONNECTSPEED       100000000 /* Connect speed: 100 Mbits/s */
150 
151 /* L2TP Session state */
152 #define PPPOL2TP_STATE_INITIAL     0
153 #define PPPOL2TP_STATE_SCCRQ_SENT  1
154 #define PPPOL2TP_STATE_ICRQ_SENT   2
155 #define PPPOL2TP_STATE_ICCN_SENT   3
156 #define PPPOL2TP_STATE_DATA        4
157 
158 #define PPPOL2TP_OUTPUT_DATA_HEADER_LEN   6 /* Our data header len */
159 
160 /*
161  * PPPoL2TP interface control block.
162  */
163 typedef struct pppol2tp_pcb_s pppol2tp_pcb;
164 struct pppol2tp_pcb_s {
165   ppp_pcb *ppp;                /* PPP PCB */
166   u8_t phase;                  /* L2TP phase */
167   struct udp_pcb *udp;         /* UDP L2TP Socket */
168   struct netif *netif;         /* Output interface, used as a default route */
169   ip_addr_t remote_ip;         /* LNS IP Address */
170   u16_t remote_port;           /* LNS port */
171 #if PPPOL2TP_AUTH_SUPPORT
172   const u8_t *secret;          /* Secret string */
173   u8_t secret_len;             /* Secret string length */
174   u8_t secret_rv[16];          /* Random vector */
175   u8_t challenge_hash[16];     /* Challenge response */
176   u8_t send_challenge;         /* Boolean whether the next sent packet should contains a challenge response */
177 #endif /* PPPOL2TP_AUTH_SUPPORT */
178 
179   u16_t tunnel_port;           /* Tunnel port */
180   u16_t our_ns;                /* NS to peer */
181   u16_t peer_nr;               /* NR from peer */
182   u16_t peer_ns;               /* NS from peer */
183   u16_t source_tunnel_id;      /* Tunnel ID assigned by peer */
184   u16_t remote_tunnel_id;      /* Tunnel ID assigned to peer */
185   u16_t source_session_id;     /* Session ID assigned by peer */
186   u16_t remote_session_id;     /* Session ID assigned to peer */
187 
188   u8_t sccrq_retried;          /* number of SCCRQ retries already done */
189   u8_t icrq_retried;           /* number of ICRQ retries already done */
190   u8_t iccn_retried;           /* number of ICCN retries already done */
191 };
192 
193 
194 /* Create a new L2TP session. */
195 ppp_pcb *pppol2tp_create(struct netif *pppif,
196        struct netif *netif, const ip_addr_t *ipaddr, u16_t port,
197        const u8_t *secret, u8_t secret_len,
198        ppp_link_status_cb_fn link_status_cb, void *ctx_cb);
199 
200 #endif /* PPPOL2TP_H */
201 #endif /* PPP_SUPPORT && PPPOL2TP_SUPPORT */
202