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1 /*
2  * netlink/handlers.c	default netlink message handlers
3  *
4  *	This library is free software; you can redistribute it and/or
5  *	modify it under the terms of the GNU Lesser General Public
6  *	License as published by the Free Software Foundation version 2.1
7  *	of the License.
8  *
9  * Copyright (c) 2003-2006 Thomas Graf <tgraf@suug.ch>
10  */
11 
12 #ifndef NETLINK_HANDLERS_H_
13 #define NETLINK_HANDLERS_H_
14 
15 #include <stdio.h>
16 #include <stdint.h>
17 #include <sys/types.h>
18 #include <netlink/netlink-compat.h>
19 #include <netlink/netlink-kernel.h>
20 
21 #ifdef __cplusplus
22 extern "C" {
23 #endif
24 
25 struct nl_cb;
26 struct nl_sock;
27 struct nl_msg;
28 struct ucred;
29 
30 /**
31  * @name Callback Typedefs
32  * @{
33  */
34 
35 /**
36  * nl_recvmsgs() callback for message processing customization
37  * @ingroup cb
38  * @arg msg		netlink message being processed
39  * @arg arg		argument passwd on through caller
40  */
41 typedef int (*nl_recvmsg_msg_cb_t)(struct nl_msg *msg, void *arg);
42 
43 /**
44  * nl_recvmsgs() callback for error message processing customization
45  * @ingroup cb
46  * @arg nla		netlink address of the peer
47  * @arg nlerr		netlink error message being processed
48  * @arg arg		argument passed on through caller
49  */
50 typedef int (*nl_recvmsg_err_cb_t)(struct sockaddr_nl *nla,
51 				   struct nlmsgerr *nlerr, void *arg);
52 
53 /** @} */
54 
55 /**
56  * Callback actions
57  * @ingroup cb
58  */
59 enum nl_cb_action {
60 	/** Proceed with wathever would come next */
61 	NL_OK,
62 	/** Skip this message */
63 	NL_SKIP,
64 	/** Stop parsing altogether and discard remaining messages */
65 	NL_STOP,
66 };
67 
68 /**
69  * Callback kinds
70  * @ingroup cb
71  */
72 enum nl_cb_kind {
73 	/** Default handlers (quiet) */
74 	NL_CB_DEFAULT,
75 	/** Verbose default handlers (error messages printed) */
76 	NL_CB_VERBOSE,
77 	/** Debug handlers for debugging */
78 	NL_CB_DEBUG,
79 	/** Customized handler specified by the user */
80 	NL_CB_CUSTOM,
81 	__NL_CB_KIND_MAX,
82 };
83 
84 #define NL_CB_KIND_MAX (__NL_CB_KIND_MAX - 1)
85 
86 /**
87  * Callback types
88  * @ingroup cb
89  */
90 enum nl_cb_type {
91 	/** Message is valid */
92 	NL_CB_VALID,
93 	/** Last message in a series of multi part messages received */
94 	NL_CB_FINISH,
95 	/** Report received that data was lost */
96 	NL_CB_OVERRUN,
97 	/** Message wants to be skipped */
98 	NL_CB_SKIPPED,
99 	/** Message is an acknowledge */
100 	NL_CB_ACK,
101 	/** Called for every message received */
102 	NL_CB_MSG_IN,
103 	/** Called for every message sent out except for nl_sendto() */
104 	NL_CB_MSG_OUT,
105 	/** Message is malformed and invalid */
106 	NL_CB_INVALID,
107 	/** Called instead of internal sequence number checking */
108 	NL_CB_SEQ_CHECK,
109 	/** Sending of an acknowledge message has been requested */
110 	NL_CB_SEND_ACK,
111 	/** Flag NLM_F_DUMP_INTR is set in message */
112 	NL_CB_DUMP_INTR,
113 	__NL_CB_TYPE_MAX,
114 };
115 
116 #define NL_CB_TYPE_MAX (__NL_CB_TYPE_MAX - 1)
117 
118 extern struct nl_cb *	nl_cb_alloc(enum nl_cb_kind);
119 extern struct nl_cb *	nl_cb_clone(struct nl_cb *);
120 extern struct nl_cb *	nl_cb_get(struct nl_cb *);
121 extern void		nl_cb_put(struct nl_cb *);
122 
123 extern int  nl_cb_set(struct nl_cb *, enum nl_cb_type, enum nl_cb_kind,
124 		      nl_recvmsg_msg_cb_t, void *);
125 extern int  nl_cb_set_all(struct nl_cb *, enum nl_cb_kind,
126 			  nl_recvmsg_msg_cb_t, void *);
127 extern int  nl_cb_err(struct nl_cb *, enum nl_cb_kind, nl_recvmsg_err_cb_t,
128 		      void *);
129 
130 extern void nl_cb_overwrite_recvmsgs(struct nl_cb *,
131 				     int (*func)(struct nl_sock *,
132 						 struct nl_cb *));
133 extern void nl_cb_overwrite_recv(struct nl_cb *,
134 				 int (*func)(struct nl_sock *,
135 					     struct sockaddr_nl *,
136 					     unsigned char **,
137 					     struct ucred **));
138 extern void nl_cb_overwrite_send(struct nl_cb *,
139 				 int (*func)(struct nl_sock *,
140 					     struct nl_msg *));
141 
142 extern enum nl_cb_type nl_cb_active_type(struct nl_cb *cb);
143 
144 #ifdef __cplusplus
145 }
146 #endif
147 
148 #endif
149