libnl  3.2.28
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 port to be set to the port assigned to
29  * the netlink icoket ust before sending the message off.
30  *
31  * @note Requires the use of nl_send_auto()!
32  */
33 #define NL_AUTO_PORT 0
34 #define NL_AUTO_PID NL_AUTO_PORT
35 
36 /**
37  * @ingroup msg
38  * @brief
39  * May be used to refer to a sequence number which should be
40  * automatically set just before sending the message off.
41  *
42  * @note Requires the use of nl_send_auto()!
43  */
44 #define NL_AUTO_SEQ 0
45 
46 struct nl_msg;
47 struct nl_tree;
48 struct ucred;
49 
50 extern int nlmsg_size(int);
51 extern int nlmsg_total_size(int);
52 extern int nlmsg_padlen(int);
53 
54 extern void * nlmsg_data(const struct nlmsghdr *);
55 extern int nlmsg_datalen(const struct nlmsghdr *);
56 extern void * nlmsg_tail(const struct nlmsghdr *);
57 
58 /* attribute access */
59 extern struct nlattr * nlmsg_attrdata(const struct nlmsghdr *, int);
60 extern int nlmsg_attrlen(const struct nlmsghdr *, int);
61 
62 /* message parsing */
63 extern int nlmsg_valid_hdr(const struct nlmsghdr *, int);
64 extern int nlmsg_ok(const struct nlmsghdr *, int);
65 extern struct nlmsghdr * nlmsg_next(struct nlmsghdr *, int *);
66 extern int nlmsg_parse(struct nlmsghdr *, int, struct nlattr **,
67  int, struct nla_policy *);
68 extern struct nlattr * nlmsg_find_attr(struct nlmsghdr *, int, int);
69 extern int nlmsg_validate(struct nlmsghdr *, int, int,
70  struct nla_policy *);
71 
72 extern struct nl_msg * nlmsg_alloc(void);
73 extern struct nl_msg * nlmsg_alloc_size(size_t);
74 extern struct nl_msg * nlmsg_alloc_simple(int, int);
75 extern void nlmsg_set_default_size(size_t);
76 extern struct nl_msg * nlmsg_inherit(struct nlmsghdr *);
77 extern struct nl_msg * nlmsg_convert(struct nlmsghdr *);
78 extern void * nlmsg_reserve(struct nl_msg *, size_t, int);
79 extern int nlmsg_append(struct nl_msg *, void *, size_t, int);
80 extern int nlmsg_expand(struct nl_msg *, size_t);
81 
82 extern struct nlmsghdr * nlmsg_put(struct nl_msg *, uint32_t, uint32_t,
83  int, int, int);
84 extern struct nlmsghdr * nlmsg_hdr(struct nl_msg *);
85 extern void nlmsg_get(struct nl_msg *);
86 extern void nlmsg_free(struct nl_msg *);
87 
88 /* attribute modification */
89 extern void nlmsg_set_proto(struct nl_msg *, int);
90 extern int nlmsg_get_proto(struct nl_msg *);
91 extern size_t nlmsg_get_max_size(struct nl_msg *);
92 extern void nlmsg_set_src(struct nl_msg *, struct sockaddr_nl *);
93 extern struct sockaddr_nl *nlmsg_get_src(struct nl_msg *);
94 extern void nlmsg_set_dst(struct nl_msg *, struct sockaddr_nl *);
95 extern struct sockaddr_nl *nlmsg_get_dst(struct nl_msg *);
96 extern void nlmsg_set_creds(struct nl_msg *, struct ucred *);
97 extern struct ucred * nlmsg_get_creds(struct nl_msg *);
98 
99 extern char * nl_nlmsgtype2str(int, char *, size_t);
100 extern int nl_str2nlmsgtype(const char *);
101 
102 extern char * nl_nlmsg_flags2str(int, char *, size_t);
103 
104 extern int nl_msg_parse(struct nl_msg *,
105  void (*cb)(struct nl_object *, void *),
106  void *);
107 
108 extern void nl_msg_dump(struct nl_msg *, FILE *);
109 
110 /**
111  * @name Iterators
112  * @{
113  */
114 
115 /**
116  * @ingroup msg
117  * Iterate over a stream of attributes in a message
118  * @arg pos loop counter, set to current attribute
119  * @arg nlh netlink message header
120  * @arg hdrlen length of family header
121  * @arg rem initialized to len, holds bytes currently remaining in stream
122  */
123 #define nlmsg_for_each_attr(pos, nlh, hdrlen, rem) \
124  nla_for_each_attr(pos, nlmsg_attrdata(nlh, hdrlen), \
125  nlmsg_attrlen(nlh, hdrlen), rem)
126 
127 /**
128  * Iterate over a stream of messages
129  * @arg pos loop counter, set to current message
130  * @arg head head of message stream
131  * @arg len length of message stream
132  */
133 #define nlmsg_for_each(pos, head, len) \
134  for (int rem = len, pos = head; \
135  nlmsg_ok(pos, rem); \
136  pos = nlmsg_next(pos, &rem))
137 
138 #define nlmsg_for_each_msg(pos, head, len, rem) \
139  nlmsg_for_each(pos, head, len)
140 
141 /** @} */
142 
143 #ifdef __cplusplus
144 }
145 #endif
146 
147 #endif
struct nl_msg * nlmsg_alloc_size(size_t)
Allocate a new netlink message with maximum payload size specified.
Definition: msg.c:307
void nlmsg_free(struct nl_msg *)
Release a reference from an netlink message.
Definition: msg.c:558
int nlmsg_attrlen(const struct nlmsghdr *, int)
length of attributes data
Definition: msg.c:154
void * nlmsg_data(const struct nlmsghdr *)
Return pointer to message payload.
Definition: msg.c:105
int nlmsg_size(int)
Calculates size of netlink message based on payload length.
Definition: msg.c:54
struct nl_msg * nlmsg_inherit(struct nlmsghdr *)
Allocate a new netlink message and inherit netlink message header.
Definition: msg.c:322
void * nlmsg_reserve(struct nl_msg *, size_t, int)
Reserve room for additional data in a netlink message.
Definition: msg.c:407
Attribute validation policy.
Definition: attr.h:67
struct nl_msg * nlmsg_alloc(void)
Allocate a new netlink message with the default maximum payload size.
Definition: msg.c:299
void nlmsg_set_default_size(size_t)
Set the default maximum message payload size for allocated messages.
Definition: msg.c:365
int nlmsg_ok(const struct nlmsghdr *, int)
check if the netlink message fits into the remaining bytes
Definition: msg.c:179
int nlmsg_parse(struct nlmsghdr *nlh, int hdrlen, struct nlattr *tb[], int maxtype, struct nla_policy *policy)
parse attributes of a netlink message
Definition: msg.c:213
struct nlattr * nlmsg_find_attr(struct nlmsghdr *, int, int)
nlmsg_find_attr - find a specific attribute in a netlink message
Definition: msg.c:231
int nlmsg_total_size(int)
Calculates size of netlink message including padding based on payload length.
Definition: msg.c:72
struct nlattr * nlmsg_attrdata(const struct nlmsghdr *, int)
head of attributes data
Definition: msg.c:143
struct nlmsghdr * nlmsg_next(struct nlmsghdr *, int *)
next netlink message in message stream
Definition: msg.c:194
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:503
int nlmsg_datalen(const struct nlmsghdr *)
Return length of message payload.
Definition: msg.c:121
void nl_msg_dump(struct nl_msg *, FILE *)
Dump message in human readable format to file descriptor.
Definition: msg.c:970
struct nlmsghdr * nlmsg_hdr(struct nl_msg *)
Return actual netlink message.
Definition: msg.c:536
int nlmsg_expand(struct nl_msg *, size_t)
Expand maximum payload size of a netlink message.
Definition: msg.c:470
int nlmsg_padlen(int)
Size of padding that needs to be added at end of message.
Definition: msg.c:87
void nlmsg_get(struct nl_msg *)
Acquire a reference on a netlink message.
Definition: msg.c:545
int nlmsg_append(struct nl_msg *, void *, size_t, int)
Append data to tail of a netlink message.
Definition: msg.c:442
struct nl_msg * nlmsg_alloc_simple(int, int)
Allocate a new netlink message.
Definition: msg.c:346
int nlmsg_validate(struct nlmsghdr *, int, int, struct nla_policy *)
nlmsg_validate - validate a netlink message including attributes
Definition: msg.c:244
struct nl_msg * nlmsg_convert(struct nlmsghdr *)
Convert a netlink message received from a netlink socket to a nl_msg.
Definition: msg.c:382