xref: /freebsd/sys/netgraph/netgraph.h (revision 4cf49a43559ed9fdad601bdcccd2c55963008675)
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@whistle.com>
38  *
39  * $FreeBSD$
40  * $Whistle: netgraph.h,v 1.24 1999/01/28 23:54:52 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  */
57 struct 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 };
66 typedef struct ng_hook *hook_p;
67 
68 /* Flags for a hook */
69 #define HK_INVALID		0x0001	/* don't trust it! */
70 
71 /*
72  * Structure of a node
73  */
74 struct ng_node {
75 	char   *name;		/* optional globally unique name */
76 	struct	ng_type *type;	/* the installed 'type' */
77 	int	flags;		/* see below for bit definitions */
78 	int	sleepers;	/* #procs sleeping on this node */
79 	int	refs;		/* number of references to this node */
80 	int	numhooks;	/* number of hooks */
81 	int	colour;		/* for graph colouring algorithms */
82 	void   *private;	/* node type dependant node ID */
83 	LIST_HEAD(hooks, ng_hook) hooks;	/* linked list of node hooks */
84 	LIST_ENTRY(ng_node)	  nodes;	/* linked list of all nodes */
85 };
86 typedef struct ng_node *node_p;
87 
88 /* Flags for a node */
89 #define NG_INVALID	0x001	/* free when all sleepers and refs go to 0 */
90 #define NG_BUSY		0x002	/* callers should sleep or wait */
91 #define NG_TOUCHED	0x004	/* to avoid cycles when 'flooding' */
92 #define NGF_TYPE1	0x10000000	/* reserved for type specific storage */
93 #define NGF_TYPE2	0x20000000	/* reserved for type specific storage */
94 #define NGF_TYPE3	0x40000000	/* reserved for type specific storage */
95 #define NGF_TYPE4	0x80000000	/* reserved for type specific storage */
96 
97 /*
98  * The structure that holds meta_data about a data packet (e.g. priority)
99  * Nodes might add or subtract options as needed if there is room.
100  * They might reallocate the struct to make more room if they need to.
101  * Meta-data is still experimental.
102  */
103 struct meta_field_header {
104 	u_long	cookie;		/* cookie for the field. Skip fields you don't
105 				 * know about (same cookie as in messgaes) */
106 	u_short type;		/* field ID */
107 	u_short len;		/* total len of this field including extra
108 				 * data */
109 	char	data[0];	/* data starts here */
110 };
111 
112 /* To zero out an option 'in place' set it's cookie to this */
113 #define INVALID_COOKIE 865455152
114 
115 /* This part of the metadata is always present if the pointer is non NULL */
116 struct ng_meta {
117 	char	priority;	/* -ve is less priority,  0 is default */
118 	char	discardability; /* higher is less valuable.. discard first */
119 	u_short allocated_len;	/* amount malloc'd */
120 	u_short used_len;	/* sum of all fields, options etc. */
121 	u_short flags;		/* see below.. generic flags */
122 	struct meta_field_header options[0];	/* add as (if) needed */
123 };
124 typedef struct ng_meta *meta_p;
125 
126 /* Flags for meta-data */
127 #define NGMF_TEST	0x01	/* discard at the last moment before sending */
128 #define NGMF_TRACE	0x02	/* trace when handing this data to a node */
129 
130 /*
131  * Structure of a node type
132  */
133 struct ng_type {
134 
135 	/* Netgraph version number (must equal NG_VERSION) */
136 	u_int32_t version;
137 
138 	/* Unique type name */
139 	const	char *name;
140 
141 	/* Module event handler (optional) */
142 	modeventhand_t	mod_event;
143 
144 	/* Node constructor */
145 	int	(*constructor)(node_p *node);
146 
147 	/* Calls using the node */
148 	int	(*rcvmsg)(node_p node, struct ng_mesg *msg,
149 				const char *retaddr, struct ng_mesg **resp);
150 	int	(*shutdown)(node_p node);
151 	int	(*newhook)(node_p node, hook_p hook, const char *name);
152 	hook_p	(*findhook)(node_p node, const char *name);
153 
154 	/* Calls using the hook */
155 	int	(*connect)(hook_p hook);	/* already linked in */
156 	int	(*rcvdata)(hook_p hook, struct mbuf *m, meta_p meta);
157 	int	(*rcvdataq)(hook_p hook, struct mbuf *m, meta_p meta);
158 	int	(*disconnect)(hook_p hook);	/* notify on disconnect */
159 
160 	/* These are private to the base netgraph code */
161 	LIST_ENTRY(ng_type) types;		/* linked list of all types */
162 	int		    refs;		/* number of instances */
163 };
164 
165 /* Send data packet with meta-data */
166 #define NG_SEND_DATA(error, hook, m, a)					\
167 	do {								\
168 		(error) = ng_send_data((hook), (m), (a));		\
169 		(m) = NULL;						\
170 		(a) = NULL;						\
171 	} while (0)
172 
173 /* Send  queued data packet with meta-data */
174 #define NG_SEND_DATAQ(error, hook, m, a)				\
175 	do {								\
176 		(error) = ng_send_dataq((hook), (m), (a));		\
177 		(m) = NULL;						\
178 		(a) = NULL;						\
179 	} while (0)
180 
181 /* Free metadata */
182 #define NG_FREE_META(a)							\
183 	do {								\
184 		if ((a)) {						\
185 			FREE((a), M_NETGRAPH);				\
186 			a = NULL;					\
187 		}							\
188 	} while (0)
189 
190 /* Free any data packet and/or meta-data */
191 #define NG_FREE_DATA(m, a)						\
192 	do {								\
193 		if ((m)) {						\
194 			m_freem((m));					\
195 			m = NULL;					\
196 		}							\
197 		NG_FREE_META((a));					\
198 	} while (0)
199 
200 /*
201  * Use the NETGRAPH_INIT() macro to link a node type into the
202  * netgraph system. This works for types compiled into the kernel
203  * as well as KLD modules. The first argument should be the type
204  * name (eg, echo) and the second a pointer to the type struct.
205  *
206  * If a different link time is desired, e.g., a device driver that
207  * needs to install its netgraph type before probing, use the
208  * NETGRAPH_INIT_ORDERED() macro instead. Deivce drivers probably
209  * want to use SI_SUB_DRIVERS instead of SI_SUB_PSEUDO.
210  */
211 
212 #define NETGRAPH_INIT_ORDERED(typename, typestructp, sub, order)	\
213 static moduledata_t ng_##typename##_mod = {				\
214 	"ng_" #typename,						\
215 	ng_mod_event,							\
216 	(typestructp)							\
217 };									\
218 DECLARE_MODULE(ng_##typename, ng_##typename##_mod, sub, order)
219 
220 #define NETGRAPH_INIT(tn, tp)						\
221 	NETGRAPH_INIT_ORDERED(tn, tp, SI_SUB_PSEUDO, SI_ORDER_ANY)
222 
223 /* Special malloc() type for netgraph structs and ctrl messages */
224 MALLOC_DECLARE(M_NETGRAPH);
225 
226 void	ng_cutlinks(node_p node);
227 int	ng_con_nodes(node_p node,
228 	     const char *name, node_p node2, const char *name2);
229 void	ng_destroy_hook(hook_p hook);
230 node_p	ng_findname(node_p node, const char *name);
231 struct	ng_type *ng_findtype(const char *type);
232 int	ng_make_node(const char *type, node_p *nodepp);
233 int	ng_make_node_common(struct ng_type *typep, node_p *nodep);
234 int	ng_mkpeer(node_p node, const char *name, const char *name2, char *type);
235 int	ng_mod_event(module_t mod, int what, void *arg);
236 int	ng_name_node(node_p node, const char *name);
237 int	ng_newtype(struct ng_type *tp);
238 int	ng_path2node(node_p here, const char *path, node_p *dest, char **rtnp);
239 int	ng_path_parse(char *addr, char **node, char **path, char **hook);
240 int	ng_queue_data(hook_p hook, struct mbuf *m, meta_p meta);
241 int	ng_queue_msg(node_p here, struct ng_mesg *msg, int len,
242 	     const char *address);
243 void	ng_release_node(node_p node);
244 void	ng_rmnode(node_p node);
245 int	ng_send_data(hook_p hook, struct mbuf *m, meta_p meta);
246 int	ng_send_dataq(hook_p hook, struct mbuf *m, meta_p meta);
247 int	ng_send_msg(node_p here, struct ng_mesg *msg,
248 	    const char *address, struct ng_mesg **resp);
249 void	ng_unname(node_p node);
250 void	ng_unref(node_p node);
251 int	ng_bypass(hook_p hook1, hook_p hook2);
252 int	ng_wait_node(node_p node, char *msg);
253 
254 #endif /* _NETGRAPH_NETGRAPH_H_ */
255 
256