libnl  1.1
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 #include <netlink/attr.h>
18 
19 #ifdef __cplusplus
20 extern "C" {
21 #endif
22 
23 #define NL_DONTPAD 0
24 
25 /**
26  * @ingroup msg
27  * @brief
28  * Will cause the netlink pid to be set to the pid assigned to
29  * the netlink handle (socket) just before sending the message off.
30  * @note Requires the use of nl_send_auto_complete()!
31  */
32 #define NL_AUTO_PID 0
33 
34 /**
35  * @ingroup msg
36  * @brief
37  * May be used to refer to a sequence number which should be
38  * automatically set just before sending the message off.
39  * @note Requires the use of nl_send_auto_complete()!
40  */
41 #define NL_AUTO_SEQ 0
42 
43 struct nl_msg;
44 struct nl_tree;
45 struct ucred;
46 
47 /* size calculations */
48 extern int nlmsg_msg_size(int);
49 extern int nlmsg_total_size(int);
50 extern int nlmsg_padlen(int);
51 
52 /* payload access */
53 extern void * nlmsg_data(const struct nlmsghdr *);
54 extern int nlmsg_len(const struct nlmsghdr *);
55 extern void * nlmsg_tail(const struct nlmsghdr *);
56 
57 /* attribute access */
58 extern struct nlattr * nlmsg_attrdata(const struct nlmsghdr *, int);
59 extern int nlmsg_attrlen(const struct nlmsghdr *, int);
60 
61 /* message parsing */
62 extern int nlmsg_valid_hdr(const struct nlmsghdr *, int);
63 extern int nlmsg_ok(const struct nlmsghdr *, int);
64 extern struct nlmsghdr * nlmsg_next(struct nlmsghdr *, int *);
65 extern int nlmsg_parse(struct nlmsghdr *, int, struct nlattr **,
66  int, struct nla_policy *);
67 extern struct nlattr * nlmsg_find_attr(struct nlmsghdr *, int, int);
68 extern int nlmsg_validate(struct nlmsghdr *, int, int,
69  struct nla_policy *);
70 
71 /* Backward compatibility */
72 #define nlmsg_new() nlmsg_alloc()
73 #define nlmsg_build_simple(a, b) nlmsg_alloc_simple(a, b)
74 #define nlmsg_build(ptr) nlmsg_inherit(ptr)
75 
76 extern struct nl_msg * nlmsg_alloc(void);
77 extern struct nl_msg * nlmsg_alloc_size(size_t);
78 extern struct nl_msg * nlmsg_alloc_simple(int, int);
79 extern void nlmsg_set_default_size(size_t);
80 extern struct nl_msg * nlmsg_inherit(struct nlmsghdr *);
81 extern struct nl_msg * nlmsg_convert(struct nlmsghdr *);
82 extern void * nlmsg_reserve(struct nl_msg *, size_t, int);
83 extern int nlmsg_append(struct nl_msg *, void *, size_t, int);
84 extern int nlmsg_expand(struct nl_msg *, size_t);
85 
86 extern struct nlmsghdr * nlmsg_put(struct nl_msg *, uint32_t, uint32_t,
87  int, int, int);
88 extern struct nlmsghdr * nlmsg_hdr(struct nl_msg *);
89 extern void nlmsg_free(struct nl_msg *);
90 
91 /* attribute modification */
92 extern void nlmsg_set_proto(struct nl_msg *, int);
93 extern int nlmsg_get_proto(struct nl_msg *);
94 extern size_t nlmsg_get_max_size(struct nl_msg *);
95 extern void nlmsg_set_src(struct nl_msg *, struct sockaddr_nl *);
96 extern struct sockaddr_nl *nlmsg_get_src(struct nl_msg *);
97 extern void nlmsg_set_dst(struct nl_msg *, struct sockaddr_nl *);
98 extern struct sockaddr_nl *nlmsg_get_dst(struct nl_msg *);
99 extern void nlmsg_set_creds(struct nl_msg *, struct ucred *);
100 extern struct ucred * nlmsg_get_creds(struct nl_msg *);
101 
102 extern char * nl_nlmsgtype2str(int, char *, size_t);
103 extern int nl_str2nlmsgtype(const char *);
104 
105 extern char * nl_nlmsg_flags2str(int, char *, size_t);
106 
107 extern int nl_msg_parse(struct nl_msg *,
108  void (*cb)(struct nl_object *, void *),
109  void *);
110 
111 extern void nl_msg_dump(struct nl_msg *, FILE *);
112 
113 /**
114  * @name Iterators
115  * @{
116  */
117 
118 /**
119  * @ingroup msg
120  * Iterate over a stream of attributes in a message
121  * @arg pos loop counter, set to current attribute
122  * @arg nlh netlink message header
123  * @arg hdrlen length of family header
124  * @arg rem initialized to len, holds bytes currently remaining in stream
125  */
126 #define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
127  nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
128  nlmsg_attrlen(nlh, hdrlen), rem)
129 
130 /**
131  * Iterate over a stream of messages
132  * @arg pos loop counter, set to current message
133  * @arg head head of message stream
134  * @arg len length of message stream
135  * @arg rem initialized to len, holds bytes currently remaining in stream
136  */
137 #define nlmsg_for_each_msg(pos, head, len, rem) \
138  for (pos = head, rem = len; \
139  nlmsg_ok(pos, rem); \
140  pos = nlmsg_next(pos, &(rem)))
141 
142 /** @} */
143 
144 #ifdef __cplusplus
145 }
146 #endif
147 
148 #endif