libnl 3.5.0

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 struct nlmsghdr;
24
25 #define NL_DONTPAD 0
26
27 /**
28 * @ingroup msg
29 * @brief
30 * Will cause the netlink port to be set to the port assigned to
31 * the netlink icoket ust before sending the message off.
32 *
33 * @note Requires the use of nl_send_auto()!
34 */
35 #define NL_AUTO_PORT 0
36 #define NL_AUTO_PID NL_AUTO_PORT
37
38 /**
39 * @ingroup msg
40 * @brief
41 * May be used to refer to a sequence number which should be
42 * automatically set just before sending the message off.
43 *
44 * @note Requires the use of nl_send_auto()!
45 */
46 #define NL_AUTO_SEQ 0
47
48 struct nl_msg;
49 struct nl_tree;
50 struct ucred;
51
52 extern int nlmsg_size(int);
53 extern int nlmsg_total_size(int);
54 extern int nlmsg_padlen(int);
55
56 extern void * nlmsg_data(const struct nlmsghdr *);
57 extern int nlmsg_datalen(const struct nlmsghdr *);
58 extern void * nlmsg_tail(const struct nlmsghdr *);
59
60 /* attribute access */
61 extern struct nlattr * nlmsg_attrdata(const struct nlmsghdr *, int);
62 extern int nlmsg_attrlen(const struct nlmsghdr *, int);
63
64 /* message parsing */
65 extern int nlmsg_valid_hdr(const struct nlmsghdr *, int);
66 extern int nlmsg_ok(const struct nlmsghdr *, int);
67 extern struct nlmsghdr * nlmsg_next(struct nlmsghdr *, int *);
68 extern int nlmsg_parse(struct nlmsghdr *, int, struct nlattr **,
69 int, const struct nla_policy *);
70 extern struct nlattr * nlmsg_find_attr(struct nlmsghdr *, int, int);
71 extern int nlmsg_validate(struct nlmsghdr *, int, int,
72 const struct nla_policy *);
73
74 extern struct nl_msg * nlmsg_alloc(void);
75 extern struct nl_msg * nlmsg_alloc_size(size_t);
76 extern struct nl_msg * nlmsg_alloc_simple(int, int);
77 extern void nlmsg_set_default_size(size_t);
78 extern struct nl_msg * nlmsg_inherit(struct nlmsghdr *);
79 extern struct nl_msg * nlmsg_convert(struct nlmsghdr *);
80 extern void * nlmsg_reserve(struct nl_msg *, size_t, int);
81 extern int nlmsg_append(struct nl_msg *, void *, size_t, int);
82 extern int nlmsg_expand(struct nl_msg *, size_t);
83
84 extern struct nlmsghdr * nlmsg_put(struct nl_msg *, uint32_t, uint32_t,
85 int, int, int);
86 extern struct nlmsghdr * nlmsg_hdr(struct nl_msg *);
87 extern void nlmsg_get(struct nl_msg *);
88 extern void nlmsg_free(struct nl_msg *);
89
90 /* attribute modification */
91 extern void nlmsg_set_proto(struct nl_msg *, int);
92 extern int nlmsg_get_proto(struct nl_msg *);
93 extern size_t nlmsg_get_max_size(struct nl_msg *);
94 extern void nlmsg_set_src(struct nl_msg *, struct sockaddr_nl *);
95 extern struct sockaddr_nl *nlmsg_get_src(struct nl_msg *);
96 extern void nlmsg_set_dst(struct nl_msg *, struct sockaddr_nl *);
97 extern struct sockaddr_nl *nlmsg_get_dst(struct nl_msg *);
98 extern void nlmsg_set_creds(struct nl_msg *, struct ucred *);
99 extern struct ucred * nlmsg_get_creds(struct nl_msg *);
100
101 extern char * nl_nlmsgtype2str(int, char *, size_t);
102 extern int nl_str2nlmsgtype(const char *);
103
104 extern char * nl_nlmsg_flags2str(int, char *, size_t);
105
106 extern int nl_msg_parse(struct nl_msg *,
107 void (*cb)(struct nl_object *, void *),
108 void *);
109
110 extern void nl_msg_dump(struct nl_msg *, FILE *);
111
112 /**
113 * @name Iterators
114 * @{
115 */
116
117 /**
118 * @ingroup msg
119 * Iterate over a stream of attributes in a message
120 * @arg pos loop counter, set to current attribute
121 * @arg nlh netlink message header
122 * @arg hdrlen length of family header
123 * @arg rem initialized to len, holds bytes currently remaining in stream
124 */
125 #define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
126 nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
127 nlmsg_attrlen(nlh, hdrlen), rem)
128
129 /**
130 * Iterate over a stream of messages
131 * @arg pos loop counter, set to current message
132 * @arg head head of message stream
133 * @arg len length of message stream
134 */
135 #define nlmsg_for_each(pos, head, len) \
136 for (int rem = len, pos = head; \
137 nlmsg_ok(pos, rem); \
138 pos = nlmsg_next(pos, &rem))
139
140 #define nlmsg_for_each_msg(pos, head, len, rem) \
141 nlmsg_for_each(pos, head, len)
142
143 /** @} */
144
145 #ifdef __cplusplus
146 }
147 #endif
148
149 #endif
nlmsg_alloc_size
struct nl_msg * nlmsg_alloc_size(size_t)
Allocate a new netlink message with maximum payload size specified.
Definition: msg.c:309
nlmsg_free
void nlmsg_free(struct nl_msg *)
Release a reference from an netlink message.
Definition: msg.c:565
nlmsg_parse
int nlmsg_parse(struct nlmsghdr *nlh, int hdrlen, struct nlattr *tb[], int maxtype, const struct nla_policy *policy)
parse attributes of a netlink message
Definition: msg.c:215
nlmsg_attrlen
int nlmsg_attrlen(const struct nlmsghdr *, int)
length of attributes data
Definition: msg.c:156
nlmsg_data
void * nlmsg_data(const struct nlmsghdr *)
Return pointer to message payload.
Definition: msg.c:107
nlmsg_size
int nlmsg_size(int)
Calculates size of netlink message based on payload length.
Definition: msg.c:56
nlmsg_inherit
struct nl_msg * nlmsg_inherit(struct nlmsghdr *)
Allocate a new netlink message and inherit netlink message header.
Definition: msg.c:324
nlmsg_reserve
void * nlmsg_reserve(struct nl_msg *, size_t, int)
Reserve room for additional data in a netlink message.
Definition: msg.c:411
nla_policy
Attribute validation policy.
Definition: attr.h:69
nlmsg_alloc
struct nl_msg * nlmsg_alloc(void)
Allocate a new netlink message with the default maximum payload size.
Definition: msg.c:301
nlmsg_set_default_size
void nlmsg_set_default_size(size_t)
Set the default maximum message payload size for allocated messages.
Definition: msg.c:369
nlmsg_ok
int nlmsg_ok(const struct nlmsghdr *, int)
check if the netlink message fits into the remaining bytes
Definition: msg.c:181
nlmsg_find_attr
struct nlattr * nlmsg_find_attr(struct nlmsghdr *, int, int)
nlmsg_find_attr - find a specific attribute in a netlink message
Definition: msg.c:233
nlmsg_total_size
int nlmsg_total_size(int)
Calculates size of netlink message including padding based on payload length.
Definition: msg.c:74
nlmsg_attrdata
struct nlattr * nlmsg_attrdata(const struct nlmsghdr *, int)
head of attributes data
Definition: msg.c:145
nlmsg_next
struct nlmsghdr * nlmsg_next(struct nlmsghdr *, int *)
next netlink message in message stream
Definition: msg.c:196
nlmsg_put
struct nlmsghdr * nlmsg_put(struct nl_msg *, uint32_t, uint32_t, int, int, int)
Add a netlink message header to a netlink message.
Definition: msg.c:510
nlmsg_datalen
int nlmsg_datalen(const struct nlmsghdr *)
Return length of message payload.
Definition: msg.c:123
nl_msg_dump
void nl_msg_dump(struct nl_msg *, FILE *)
Dump message in human readable format to file descriptor.
Definition: msg.c:976
nlmsg_hdr
struct nlmsghdr * nlmsg_hdr(struct nl_msg *)
Return actual netlink message.
Definition: msg.c:543
nlmsg_expand
int nlmsg_expand(struct nl_msg *, size_t)
Expand maximum payload size of a netlink message.
Definition: msg.c:477
nlmsg_validate
int nlmsg_validate(struct nlmsghdr *, int, int, const struct nla_policy *)
nlmsg_validate - validate a netlink message including attributes
Definition: msg.c:246
nlmsg_padlen
int nlmsg_padlen(int)
Size of padding that needs to be added at end of message.
Definition: msg.c:89
nlmsg_get
void nlmsg_get(struct nl_msg *)
Acquire a reference on a netlink message.
Definition: msg.c:552
nlmsg_append
int nlmsg_append(struct nl_msg *, void *, size_t, int)
Append data to tail of a netlink message.
Definition: msg.c:449
nlmsg_alloc_simple
struct nl_msg * nlmsg_alloc_simple(int, int)
Allocate a new netlink message.
Definition: msg.c:348
nlmsg_convert
struct nl_msg * nlmsg_convert(struct nlmsghdr *)
Convert a netlink message received from a netlink socket to a nl_msg.
Definition: msg.c:386