Root/package/libs/libnl-tiny/src/include/netlink/msg.h

1/*
2 * netlink/msg.c Netlink Messages Interface
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_MSG_H_
13#define NETLINK_MSG_H_
14
15#include <netlink/netlink.h>
16#include <netlink/object.h>
17
18#ifdef __cplusplus
19extern "C" {
20#endif
21
22struct nla_policy;
23
24#define NL_DONTPAD 0
25
26/**
27 * @ingroup msg
28 * @brief
29 * Will cause the netlink pid to be set to the pid assigned to
30 * the netlink handle (socket) just before sending the message off.
31 * @note Requires the use of nl_send_auto_complete()!
32 */
33#define NL_AUTO_PID 0
34
35/**
36 * @ingroup msg
37 * @brief
38 * May be used to refer to a sequence number which should be
39 * automatically set just before sending the message off.
40 * @note Requires the use of nl_send_auto_complete()!
41 */
42#define NL_AUTO_SEQ 0
43
44#define NL_MSG_CRED_PRESENT 1
45
46struct nl_msg
47{
48    int nm_protocol;
49    int nm_flags;
50    struct sockaddr_nl nm_src;
51    struct sockaddr_nl nm_dst;
52    struct ucred nm_creds;
53    struct nlmsghdr * nm_nlh;
54    size_t nm_size;
55    int nm_refcnt;
56};
57
58
59struct nl_msg;
60struct nl_tree;
61struct ucred;
62
63/* message parsing */
64extern int nlmsg_ok(const struct nlmsghdr *, int);
65extern struct nlmsghdr * nlmsg_next(struct nlmsghdr *, int *);
66extern int nlmsg_parse(struct nlmsghdr *, int, struct nlattr **,
67                      int, struct nla_policy *);
68extern int nlmsg_validate(struct nlmsghdr *, int, int,
69                     struct nla_policy *);
70
71extern struct nl_msg * nlmsg_alloc(void);
72extern struct nl_msg * nlmsg_alloc_size(size_t);
73extern struct nl_msg * nlmsg_alloc_simple(int, int);
74extern void nlmsg_set_default_size(size_t);
75extern struct nl_msg * nlmsg_inherit(struct nlmsghdr *);
76extern struct nl_msg * nlmsg_convert(struct nlmsghdr *);
77extern void * nlmsg_reserve(struct nl_msg *, size_t, int);
78extern int nlmsg_append(struct nl_msg *, void *, size_t, int);
79
80extern struct nlmsghdr * nlmsg_put(struct nl_msg *, uint32_t, uint32_t,
81                    int, int, int);
82extern void nlmsg_free(struct nl_msg *);
83
84extern int nl_msg_parse(struct nl_msg *,
85                       void (*cb)(struct nl_object *, void *),
86                       void *);
87
88extern void nl_msg_dump(struct nl_msg *, FILE *);
89
90/**
91 * length of netlink message not including padding
92 * @arg payload length of message payload
93 */
94static inline int nlmsg_msg_size(int payload)
95{
96    return NLMSG_HDRLEN + payload;
97}
98
99/**
100 * length of netlink message including padding
101 * @arg payload length of message payload
102 */
103static inline int nlmsg_total_size(int payload)
104{
105    return NLMSG_ALIGN(nlmsg_msg_size(payload));
106}
107
108/**
109 * length of padding at the message's tail
110 * @arg payload length of message payload
111 */
112static inline int nlmsg_padlen(int payload)
113{
114    return nlmsg_total_size(payload) - nlmsg_msg_size(payload);
115}
116
117/**
118 * head of message payload
119 * @arg nlh netlink messsage header
120 */
121static inline void *nlmsg_data(const struct nlmsghdr *nlh)
122{
123    return (unsigned char *) nlh + NLMSG_HDRLEN;
124}
125
126static inline void *nlmsg_tail(const struct nlmsghdr *nlh)
127{
128    return (unsigned char *) nlh + NLMSG_ALIGN(nlh->nlmsg_len);
129}
130
131/**
132 * length of message payload
133 * @arg nlh netlink message header
134 */
135static inline int nlmsg_len(const struct nlmsghdr *nlh)
136{
137    return nlh->nlmsg_len - NLMSG_HDRLEN;
138}
139
140/**
141 * head of attributes data
142 * @arg nlh netlink message header
143 * @arg hdrlen length of family specific header
144 */
145static inline struct nlattr *nlmsg_attrdata(const struct nlmsghdr *nlh, int hdrlen)
146{
147    unsigned char *data = (unsigned char*)nlmsg_data(nlh);
148    return (struct nlattr *) (data + NLMSG_ALIGN(hdrlen));
149}
150
151/**
152 * length of attributes data
153 * @arg nlh netlink message header
154 * @arg hdrlen length of family specific header
155 */
156static inline int nlmsg_attrlen(const struct nlmsghdr *nlh, int hdrlen)
157{
158    return nlmsg_len(nlh) - NLMSG_ALIGN(hdrlen);
159}
160
161static inline int nlmsg_valid_hdr(const struct nlmsghdr *nlh, int hdrlen)
162{
163    if (nlh->nlmsg_len < (uint)nlmsg_msg_size(hdrlen))
164        return 0;
165
166    return 1;
167}
168
169
170static inline void nlmsg_set_proto(struct nl_msg *msg, int protocol)
171{
172    msg->nm_protocol = protocol;
173}
174
175static inline int nlmsg_get_proto(struct nl_msg *msg)
176{
177    return msg->nm_protocol;
178}
179
180static inline size_t nlmsg_get_max_size(struct nl_msg *msg)
181{
182    return msg->nm_size;
183}
184
185static inline void nlmsg_set_src(struct nl_msg *msg, struct sockaddr_nl *addr)
186{
187    memcpy(&msg->nm_src, addr, sizeof(*addr));
188}
189
190static inline struct sockaddr_nl *nlmsg_get_src(struct nl_msg *msg)
191{
192    return &msg->nm_src;
193}
194
195static inline void nlmsg_set_dst(struct nl_msg *msg, struct sockaddr_nl *addr)
196{
197    memcpy(&msg->nm_dst, addr, sizeof(*addr));
198}
199
200static inline struct sockaddr_nl *nlmsg_get_dst(struct nl_msg *msg)
201{
202    return &msg->nm_dst;
203}
204
205static inline void nlmsg_set_creds(struct nl_msg *msg, struct ucred *creds)
206{
207    memcpy(&msg->nm_creds, creds, sizeof(*creds));
208    msg->nm_flags |= NL_MSG_CRED_PRESENT;
209}
210
211static inline struct ucred *nlmsg_get_creds(struct nl_msg *msg)
212{
213    if (msg->nm_flags & NL_MSG_CRED_PRESENT)
214        return &msg->nm_creds;
215    return NULL;
216}
217
218/**
219 * Return actual netlink message
220 * @arg n netlink message
221 *
222 * Returns the actual netlink message casted to the type of the netlink
223 * message header.
224 *
225 * @return A pointer to the netlink message.
226 */
227static inline struct nlmsghdr *nlmsg_hdr(struct nl_msg *n)
228{
229    return n->nm_nlh;
230}
231
232/**
233 * Acquire a reference on a netlink message
234 * @arg msg message to acquire reference from
235 */
236static inline void nlmsg_get(struct nl_msg *msg)
237{
238    msg->nm_refcnt++;
239}
240
241/**
242 * Expand maximum payload size of a netlink message
243 * @arg n Netlink message.
244 * @arg newlen New maximum payload size.
245 *
246 * Reallocates the payload section of a netlink message and increases
247 * the maximum payload size of the message.
248 *
249 * @note Any pointers pointing to old payload block will be stale and
250 * need to be refetched. Therfore, do not expand while constructing
251 * nested attributes or while reserved data blocks are held.
252 *
253 * @return 0 on success or a negative error code.
254 */
255static inline int nlmsg_expand(struct nl_msg *n, size_t newlen)
256{
257    void *tmp;
258
259    if (newlen <= n->nm_size)
260        return -NLE_INVAL;
261
262    tmp = realloc(n->nm_nlh, newlen);
263    if (tmp == NULL)
264        return -NLE_NOMEM;
265
266    n->nm_nlh = (struct nlmsghdr*)tmp;
267    n->nm_size = newlen;
268
269    return 0;
270}
271
272
273/**
274 * @name Iterators
275 * @{
276 */
277
278/**
279 * @ingroup msg
280 * Iterate over a stream of attributes in a message
281 * @arg pos loop counter, set to current attribute
282 * @arg nlh netlink message header
283 * @arg hdrlen length of family header
284 * @arg rem initialized to len, holds bytes currently remaining in stream
285 */
286#define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
287    nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
288              nlmsg_attrlen(nlh, hdrlen), rem)
289
290/**
291 * Iterate over a stream of messages
292 * @arg pos loop counter, set to current message
293 * @arg head head of message stream
294 * @arg len length of message stream
295 * @arg rem initialized to len, holds bytes currently remaining in stream
296 */
297#define nlmsg_for_each_msg(pos, head, len, rem) \
298    for (pos = head, rem = len; \
299         nlmsg_ok(pos, rem); \
300         pos = nlmsg_next(pos, &(rem)))
301
302/** @} */
303
304#ifdef __cplusplus
305}
306#endif
307
308#endif
309

Archive Download this file

Branches:
backfire
history
master
release_2010-11-17
release_2010-12-14
release_2011-02-23
release_2011-05-28
release_2011-08-27
release_2011-11-13
release_2012-03-18
release_2012-04-09
release_2012-10-11
uclibc_nptl



interactive