1
2/*
3 * netgraph.h
4 *
5 * Copyright (c) 1996-1999 Whistle Communications, Inc.
6 * All rights reserved.
7 *
8 * Subject to the following obligations and disclaimer of warranty, use and
9 * redistribution of this software, in source or object code forms, with or
10 * without modifications are expressly permitted by Whistle Communications;
11 * provided, however, that:
12 * 1. Any and all reproductions of the source or object code must include the
13 * copyright notice above and the following disclaimer of warranties; and
14 * 2. No rights are granted, in any manner or form, to use Whistle
15 * Communications, Inc. trademarks, including the mark "WHISTLE
16 * COMMUNICATIONS" on advertising, endorsements, or otherwise except as
17 * such appears in the above copyright notice or in the software.
18 *
19 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
20 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
21 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
22 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
23 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
24 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
25 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
26 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
27 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
28 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
29 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
30 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
31 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
32 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
35 * OF SUCH DAMAGE.
36 *
37 * Author: Julian Elischer <julian@freebsd.org>
38 *
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40 * $Whistle: netgraph.h,v 1.29 1999/11/01 07:56:13 julian Exp $
41 */
42
43#ifndef _NETGRAPH_NETGRAPH_H_
44#define _NETGRAPH_NETGRAPH_H_ 1
45
46#include <sys/queue.h>
47#include <sys/malloc.h>
48#include <sys/module.h>
49
50#ifndef _KERNEL
51#error "This file should not be included in user level programs"
52#endif
53
54/*
55 * Structure of a hook
56 */
57struct ng_hook {
58 char *name; /* what this node knows this link as */
59 void *private; /* node dependant ID for this hook */
60 int flags; /* info about this hook/link */
61 int refs; /* dont actually free this till 0 */
62 struct ng_hook *peer; /* the other end of this link */
63 struct ng_node *node; /* The node this hook is attached to */
64 LIST_ENTRY(ng_hook) hooks; /* linked list of all hooks on node */
65};
66typedef struct ng_hook *hook_p;
67
68/* Flags for a hook */
69#define HK_INVALID 0x0001 /* don't trust it! */
70#define HK_QUEUE 0x0002 /* queue for later delivery */
71
72/*
73 * Structure of a node
74 */
75struct ng_node {
76 char *name; /* optional globally unique name */
77 struct ng_type *type; /* the installed 'type' */
78 int flags; /* see below for bit definitions */
79 int sleepers; /* #procs sleeping on this node */
80 int refs; /* number of references to this node */
81 int numhooks; /* number of hooks */
82 int colour; /* for graph colouring algorithms */
83 void *private; /* node type dependant node ID */
84 ng_ID_t ID; /* Unique per node */
85 LIST_HEAD(hooks, ng_hook) hooks; /* linked list of node hooks */
86 LIST_ENTRY(ng_node) nodes; /* linked list of all nodes */
87 LIST_ENTRY(ng_node) idnodes; /* ID hash collision list */
88};
89typedef struct ng_node *node_p;
90
91/* Flags for a node */
92#define NG_INVALID 0x001 /* free when all sleepers and refs go to 0 */
93#define NG_BUSY 0x002 /* callers should sleep or wait */
94#define NG_TOUCHED 0x004 /* to avoid cycles when 'flooding' */
95#define NGF_TYPE1 0x10000000 /* reserved for type specific storage */
96#define NGF_TYPE2 0x20000000 /* reserved for type specific storage */
97#define NGF_TYPE3 0x40000000 /* reserved for type specific storage */
98#define NGF_TYPE4 0x80000000 /* reserved for type specific storage */
99
100/*
101 * The structure that holds meta_data about a data packet (e.g. priority)
102 * Nodes might add or subtract options as needed if there is room.
103 * They might reallocate the struct to make more room if they need to.
104 * Meta-data is still experimental.
105 */
106struct meta_field_header {
107 u_long cookie; /* cookie for the field. Skip fields you don't
108 * know about (same cookie as in messgaes) */
109 u_short type; /* field ID */
110 u_short len; /* total len of this field including extra
111 * data */
112 char data[0]; /* data starts here */
113};
114
115/* To zero out an option 'in place' set it's cookie to this */
116#define NGM_INVALID_COOKIE 865455152
117
118/* This part of the metadata is always present if the pointer is non NULL */
119struct ng_meta {
120 char priority; /* -ve is less priority, 0 is default */
121 char discardability; /* higher is less valuable.. discard first */
122 u_short allocated_len; /* amount malloc'd */
123 u_short used_len; /* sum of all fields, options etc. */
124 u_short flags; /* see below.. generic flags */
125 struct meta_field_header options[0]; /* add as (if) needed */
126};
127typedef struct ng_meta *meta_p;
128
129/* Flags for meta-data */
130#define NGMF_TEST 0x01 /* discard at the last moment before sending */
131#define NGMF_TRACE 0x02 /* trace when handing this data to a node */
132
133/* node method definitions */
134typedef int ng_constructor_t(node_p *node);
135typedef int ng_rcvmsg_t(node_p node, struct ng_mesg *msg,
136 const char *retaddr, struct ng_mesg **resp,
137 hook_p lasthook);
138typedef int ng_shutdown_t(node_p node);
139typedef int ng_newhook_t(node_p node, hook_p hook, const char *name);
140typedef hook_p ng_findhook_t(node_p node, const char *name);
141typedef int ng_connect_t(hook_p hook);
142typedef int ng_rcvdata_t(hook_p hook, struct mbuf *m, meta_p meta,
143 struct mbuf **ret_m, meta_p *ret_meta, struct ng_mesg **resp);
144typedef int ng_disconnect_t(hook_p hook);
145
146/*
147 * Command list -- each node type specifies the command that it knows
148 * how to convert between ASCII and binary using an array of these.
149 * The last element in the array must be a terminator with cookie=0.
150 */
151
152struct ng_cmdlist {
153 u_int32_t cookie; /* command typecookie */
154 int cmd; /* command number */
155 const char *name; /* command name */
156 const struct ng_parse_type *mesgType; /* args if !NGF_RESP */
157 const struct ng_parse_type *respType; /* args if NGF_RESP */
158};
159
160/*
161 * Structure of a node type
162 * If data is sent to the "rcvdata()" entrypoint then the system
163 * may decide to defer it until later by queing it with the normal netgraph
164 * input queuing system. This is decidde by the HK_QUEUE flag being set in
165 * the flags word of the peer (receiving) hook. The dequeuing mechanism will
166 * ensure it is not requeued again.
167 * Note the input queueing system is to allow modules
168 * to 'release the stack' or to pass data across spl layers.
169 * The data will be redelivered as soon as the NETISR code runs
170 * which may be almost immediatly. A node may also do it's own queueing
171 * for other reasons (e.g. device output queuing).
172 */
173struct ng_type {
174
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201/* Send data packet with meta-data */
202#define NG_SEND_DATA(err, hook, m, meta) \
203 do { \
204 (err) = ng_send_data((hook), (m), (meta), \
205 NULL, NULL, NULL); \
206 (m) = NULL; \
207 (meta) = NULL; \
208 } while (0)
209
210/* Send data packet with no meta-data */
211#define NG_SEND_DATA_ONLY(err, hook, m) \
212 do { \
213 (err) = ng_send_data((hook), (m), NULL, \
214 NULL, NULL, NULL); \
215 (m) = NULL; \
216 } while (0)
217
218/* Send data packet including a possible sync response pointer */
219#define NG_SEND_DATA_RESP(err, hook, m, meta, rmsg) \
220 do { \
221 (err) = ng_send_data((hook), (m), (meta), \
222 NULL, NULL, rmsg); \
223 (m) = NULL; \
224 (meta) = NULL; \
225 } while (0)
226
227/*
228 * Send data packet including a possible sync response pointer
229 * Allow the callee to replace the data and pass it back
230 * or to simply 'reject it' or 'keep it'
231 */
232#define NG_SEND_DATA_RET(err, hook, m, meta, rmsg) \
233 do { \
234 struct mbuf *rm = NULL; \
235 meta_p rmeta = NULL; \
236 (err) = ng_send_data((hook), (m), (meta), \
237 &rm, &rmeta, (rmsg)); \
238 (m) = rm; \
239 (meta) = rmeta; \
240 } while (0)
241
242
243/* Free metadata */
244#define NG_FREE_META(meta) \
245 do { \
246 if ((meta)) { \
247 FREE((meta), M_NETGRAPH); \
248 meta = NULL; \
249 } \
250 } while (0)
251
252/* Free any data packet and/or meta-data */
253#define NG_FREE_DATA(m, meta) \
254 do { \
255 if ((m)) { \
256 m_freem((m)); \
257 m = NULL; \
258 } \
259 NG_FREE_META((meta)); \
260 } while (0)
261
262/*
263 * Use the NETGRAPH_INIT() macro to link a node type into the
264 * netgraph system. This works for types compiled into the kernel
265 * as well as KLD modules. The first argument should be the type
266 * name (eg, echo) and the second a pointer to the type struct.
267 *
268 * If a different link time is desired, e.g., a device driver that
269 * needs to install its netgraph type before probing, use the
270 * NETGRAPH_INIT_ORDERED() macro instead. Deivce drivers probably
271 * want to use SI_SUB_DRIVERS instead of SI_SUB_PSEUDO.
272 */
273
274#define NETGRAPH_INIT_ORDERED(typename, typestructp, sub, order) \
275static moduledata_t ng_##typename##_mod = { \
276 "ng_" #typename, \
277 ng_mod_event, \
278 (typestructp) \
279}; \
280DECLARE_MODULE(ng_##typename, ng_##typename##_mod, sub, order); \
281MODULE_DEPEND(ng_##typename, netgraph, 1, 1, 1)
282
283#define NETGRAPH_INIT(tn, tp) \
284 NETGRAPH_INIT_ORDERED(tn, tp, SI_SUB_PSEUDO, SI_ORDER_ANY)
285
286/* Special malloc() type for netgraph structs and ctrl messages */
287MALLOC_DECLARE(M_NETGRAPH);
288
289int ng_bypass(hook_p hook1, hook_p hook2);
290void ng_cutlinks(node_p node);
291int ng_con_nodes(node_p node,
292 const char *name, node_p node2, const char *name2);
293meta_p ng_copy_meta(meta_p meta);
294void ng_destroy_hook(hook_p hook);
295hook_p ng_findhook(node_p node, const char *name);
296node_p ng_findname(node_p node, const char *name);
297struct ng_type *ng_findtype(const char *type);
298int ng_make_node(const char *type, node_p *nodepp);
299int ng_make_node_common(struct ng_type *typep, node_p *nodep);
300int ng_mkpeer(node_p node, const char *name, const char *name2, char *type);
301int ng_mod_event(module_t mod, int what, void *arg);
302int ng_name_node(node_p node, const char *name);
303int ng_newtype(struct ng_type *tp);
304ng_ID_t ng_node2ID(node_p node);
305int ng_path2node(node_p here, const char *path,
306 node_p *dest, hook_p *lasthook);
307int ng_path_parse(char *addr, char **node, char **path, char **hook);
308int ng_queue_data(hook_p hook, struct mbuf *m, meta_p meta);
309int ng_queue_msg(node_p here, struct ng_mesg *msg, const char *address,
310 hook_p hook, char *retaddr);
311void ng_release_node(node_p node);
312void ng_rmnode(node_p node);
313int ng_send_data(hook_p hook, struct mbuf *m, meta_p meta,
314 struct mbuf **ret_m, meta_p *ret_meta, struct ng_mesg **resp);
315int ng_send_msg(node_p here, struct ng_mesg *msg, const char *address,
316 hook_p hook, char *retaddr, struct ng_mesg **resp);
317void ng_unname(node_p node);
318void ng_unref(node_p node);
319int ng_wait_node(node_p node, char *msg);
320
321#endif /* _NETGRAPH_NETGRAPH_H_ */
322
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