1 /*
2  * net/tipc/bearer.h: Include file for TIPC bearer code
3  *
4  * Copyright (c) 1996-2006, Ericsson AB
5  * Copyright (c) 2005, 2010-2011, Wind River Systems
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the names of the copyright holders nor the names of its
17  *    contributors may be used to endorse or promote products derived from
18  *    this software without specific prior written permission.
19  *
20  * Alternatively, this software may be distributed under the terms of the
21  * GNU General Public License ("GPL") version 2 as published by the Free
22  * Software Foundation.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
25  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
28  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34  * POSSIBILITY OF SUCH DAMAGE.
35  */
36 
37 #ifndef _TIPC_BEARER_H
38 #define _TIPC_BEARER_H
39 
40 #include "bcast.h"
41 
42 #define MAX_BEARERS	2
43 #define MAX_MEDIA	2
44 
45 /*
46  * Identifiers associated with TIPC message header media address info
47  *
48  * - address info field is 20 bytes long
49  * - media type identifier located at offset 3
50  * - remaining bytes vary according to media type
51  */
52 
53 #define TIPC_MEDIA_ADDR_SIZE	20
54 #define TIPC_MEDIA_TYPE_OFFSET	3
55 
56 /*
57  * Identifiers of supported TIPC media types
58  */
59 #define TIPC_MEDIA_TYPE_ETH	1
60 
61 /*
62  * struct tipc_media_addr - destination address used by TIPC bearers
63  * @value: address info (format defined by media)
64  * @media_id: TIPC media type identifier
65  * @broadcast: non-zero if address is a broadcast address
66  */
67 
68 struct tipc_media_addr {
69 	u8 value[TIPC_MEDIA_ADDR_SIZE];
70 	u8 media_id;
71 	u8 broadcast;
72 };
73 
74 struct tipc_bearer;
75 
76 /**
77  * struct tipc_media - TIPC media information available to internal users
78  * @send_msg: routine which handles buffer transmission
79  * @enable_bearer: routine which enables a bearer
80  * @disable_bearer: routine which disables a bearer
81  * @addr2str: routine which converts media address to string
82  * @str2addr: routine which converts media address from string
83  * @addr2msg: routine which converts media address to protocol message area
84  * @msg2addr: routine which converts media address from protocol message area
85  * @bcast_addr: media address used in broadcasting
86  * @priority: default link (and bearer) priority
87  * @tolerance: default time (in ms) before declaring link failure
88  * @window: default window (in packets) before declaring link congestion
89  * @type_id: TIPC media identifier
90  * @name: media name
91  */
92 
93 struct tipc_media {
94 	int (*send_msg)(struct sk_buff *buf,
95 			struct tipc_bearer *b_ptr,
96 			struct tipc_media_addr *dest);
97 	int (*enable_bearer)(struct tipc_bearer *b_ptr);
98 	void (*disable_bearer)(struct tipc_bearer *b_ptr);
99 	int (*addr2str)(struct tipc_media_addr *a, char *str_buf, int str_size);
100 	int (*str2addr)(struct tipc_media_addr *a, char *str_buf);
101 	int (*addr2msg)(struct tipc_media_addr *a, char *msg_area);
102 	int (*msg2addr)(struct tipc_media_addr *a, char *msg_area);
103 	struct tipc_media_addr bcast_addr;
104 	u32 priority;
105 	u32 tolerance;
106 	u32 window;
107 	u32 type_id;
108 	char name[TIPC_MAX_MEDIA_NAME];
109 };
110 
111 /**
112  * struct tipc_bearer - TIPC bearer structure
113  * @usr_handle: pointer to additional media-specific information about bearer
114  * @mtu: max packet size bearer can support
115  * @blocked: non-zero if bearer is blocked
116  * @lock: spinlock for controlling access to bearer
117  * @addr: media-specific address associated with bearer
118  * @name: bearer name (format = media:interface)
119  * @media: ptr to media structure associated with bearer
120  * @priority: default link priority for bearer
121  * @window: default window size for bearer
122  * @tolerance: default link tolerance for bearer
123  * @identity: array index of this bearer within TIPC bearer array
124  * @link_req: ptr to (optional) structure making periodic link setup requests
125  * @links: list of non-congested links associated with bearer
126  * @cong_links: list of congested links associated with bearer
127  * @active: non-zero if bearer structure is represents a bearer
128  * @net_plane: network plane ('A' through 'H') currently associated with bearer
129  * @nodes: indicates which nodes in cluster can be reached through bearer
130  *
131  * Note: media-specific code is responsible for initialization of the fields
132  * indicated below when a bearer is enabled; TIPC's generic bearer code takes
133  * care of initializing all other fields.
134  */
135 struct tipc_bearer {
136 	void *usr_handle;			/* initalized by media */
137 	u32 mtu;				/* initalized by media */
138 	int blocked;				/* initalized by media */
139 	struct tipc_media_addr addr;		/* initalized by media */
140 	char name[TIPC_MAX_BEARER_NAME];
141 	spinlock_t lock;
142 	struct tipc_media *media;
143 	u32 priority;
144 	u32 window;
145 	u32 tolerance;
146 	u32 identity;
147 	struct tipc_link_req *link_req;
148 	struct list_head links;
149 	struct list_head cong_links;
150 	int active;
151 	char net_plane;
152 	struct tipc_node_map nodes;
153 };
154 
155 struct tipc_bearer_names {
156 	char media_name[TIPC_MAX_MEDIA_NAME];
157 	char if_name[TIPC_MAX_IF_NAME];
158 };
159 
160 struct tipc_link;
161 
162 extern struct tipc_bearer tipc_bearers[];
163 
164 /*
165  * TIPC routines available to supported media types
166  */
167 int tipc_register_media(struct tipc_media *m_ptr);
168 
169 void tipc_recv_msg(struct sk_buff *buf, struct tipc_bearer *tb_ptr);
170 
171 int  tipc_block_bearer(const char *name);
172 void tipc_continue(struct tipc_bearer *tb_ptr);
173 
174 int tipc_enable_bearer(const char *bearer_name, u32 disc_domain, u32 priority);
175 int tipc_disable_bearer(const char *name);
176 
177 /*
178  * Routines made available to TIPC by supported media types
179  */
180 int  tipc_eth_media_start(void);
181 void tipc_eth_media_stop(void);
182 
183 int tipc_media_set_priority(const char *name, u32 new_value);
184 int tipc_media_set_window(const char *name, u32 new_value);
185 void tipc_media_addr_printf(struct print_buf *pb, struct tipc_media_addr *a);
186 struct sk_buff *tipc_media_get_names(void);
187 
188 struct sk_buff *tipc_bearer_get_names(void);
189 void tipc_bearer_add_dest(struct tipc_bearer *b_ptr, u32 dest);
190 void tipc_bearer_remove_dest(struct tipc_bearer *b_ptr, u32 dest);
191 void tipc_bearer_schedule(struct tipc_bearer *b_ptr, struct tipc_link *l_ptr);
192 struct tipc_bearer *tipc_bearer_find(const char *name);
193 struct tipc_bearer *tipc_bearer_find_interface(const char *if_name);
194 struct tipc_media *tipc_media_find(const char *name);
195 int tipc_bearer_resolve_congestion(struct tipc_bearer *b_ptr,
196 				   struct tipc_link *l_ptr);
197 int tipc_bearer_congested(struct tipc_bearer *b_ptr, struct tipc_link *l_ptr);
198 void tipc_bearer_stop(void);
199 void tipc_bearer_lock_push(struct tipc_bearer *b_ptr);
200 
201 
202 /**
203  * tipc_bearer_send- sends buffer to destination over bearer
204  *
205  * Returns true (1) if successful, or false (0) if unable to send
206  *
207  * IMPORTANT:
208  * The media send routine must not alter the buffer being passed in
209  * as it may be needed for later retransmission!
210  *
211  * If the media send routine returns a non-zero value (indicating that
212  * it was unable to send the buffer), it must:
213  *   1) mark the bearer as blocked,
214  *   2) call tipc_continue() once the bearer is able to send again.
215  * Media types that are unable to meet these two critera must ensure their
216  * send routine always returns success -- even if the buffer was not sent --
217  * and let TIPC's link code deal with the undelivered message.
218  */
219 
tipc_bearer_send(struct tipc_bearer * b_ptr,struct sk_buff * buf,struct tipc_media_addr * dest)220 static inline int tipc_bearer_send(struct tipc_bearer *b_ptr,
221 				   struct sk_buff *buf,
222 				   struct tipc_media_addr *dest)
223 {
224 	return !b_ptr->media->send_msg(buf, b_ptr, dest);
225 }
226 
227 #endif	/* _TIPC_BEARER_H */
228