1 /*****************************************************************************
2  * Copyright (C) 2008 Katalix Systems Ltd
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
17  *
18  *****************************************************************************/
19 
20 /*
21  * OpenL2TP application event interface definition.
22  *
23  * This plugin is used by OpenL2TP to receive events from pppd.
24  *
25  * Events are used as follows:-
26  * PPP_UPDOWN_IND   - tells OpenL2TP of PPP session state changes.
27  * PPP_ACCM_IND               - tells OpenL2TP of PPP ACCM negotiated options
28  *
29  * Non-GPL applications are permitted to use this API, provided that
30  * any changes to this source file are made available under GPL terms.
31  */
32 
33 #ifndef L2TP_EVENT_H
34 #define L2TP_EVENT_H
35 
36 #include <stdint.h>
37 
38 /*****************************************************************************
39  * API definition
40  *****************************************************************************/
41 
42 #define OPENL2TP_EVENT_SOCKET_NAME                "/tmp/openl2tp-event.sock"
43 
44 #define OPENL2TP_MSG_TYPE_NULL                              0
45 #define OPENL2TP_MSG_TYPE_PPP_UPDOWN_IND          1
46 #define OPENL2TP_MSG_TYPE_PPP_ACCM_IND            2
47 #define OPENL2TP_MSG_TYPE_MAX                     3
48 
49 enum {
50           OPENL2TP_TLV_TYPE_TUNNEL_ID,
51           OPENL2TP_TLV_TYPE_SESSION_ID,
52           OPENL2TP_TLV_TYPE_PPP_ACCM,
53           OPENL2TP_TLV_TYPE_PPP_UNIT,
54           OPENL2TP_TLV_TYPE_PPP_IFNAME,
55           OPENL2TP_TLV_TYPE_PPP_USER_NAME,
56           OPENL2TP_TLV_TYPE_PPP_STATE
57 };
58 #define OPENL2TP_TLV_TYPE_MAX           (OPENL2TP_TLV_TYPE_PPP_STATE + 1)
59 
60 #define OPENL2TP_MSG_MAX_LEN            512
61 #define OPENL2TP_MSG_SIGNATURE                    0x6b6c7831
62 
63 #define ALIGN32(n) (((n) + 3) & ~3)
64 
65 /* Each data field in a message is defined by a Type-Length-Value
66  * (TLV) tuplet.
67  */
68 struct openl2tp_event_tlv {
69           uint16_t  tlv_type;
70           uint16_t  tlv_len;
71           uint8_t             tlv_value[0];
72 };
73 
74 /* Messages contain a small header followed by a list of TLVs. Each
75  * TLV starts on a 4-byte boundary.
76  */
77 struct openl2tp_event_msg {
78           uint32_t  msg_signature;      /* OPENL2TP_MSG_SIGNATURE */
79           uint16_t  msg_type; /* OPENL2TP_MSG_TYPE_* */
80           uint16_t  msg_len;  /* length of data that follows */
81           uint8_t             msg_data[0];        /* list of TLVs, each always longword aligned */
82 };
83 
84 /* These structs define the data field layout of each TLV.
85  */
86 struct openl2tp_tlv_tunnel_id {
87           uint16_t  tunnel_id;
88 };
89 
90 struct openl2tp_tlv_session_id {
91           uint16_t  session_id;
92 };
93 
94 struct openl2tp_tlv_ppp_accm {
95           uint32_t  send_accm;
96           uint32_t  recv_accm;
97 };
98 
99 struct openl2tp_tlv_ppp_unit {
100           uint32_t  unit;
101 };
102 
103 struct openl2tp_tlv_ppp_state {
104           uint8_t             up;                 /* 0=down, 1=up */
105 };
106 
107 struct openl2tp_tlv_ppp_ifname {
108           char                ifname[0];
109 };
110 
111 struct openl2tp_tlv_ppp_user_name {
112           char                user_name[0];
113 };
114 
115 #endif /* L2TP_EVENT_H */
116