1 /*
2 * msgbuff.h - netlink message buffer
3 *
4 * Declarations of netlink message buffer and related functions.
5 */
6
7 #ifndef ETHTOOL_NETLINK_MSGBUFF_H__
8 #define ETHTOOL_NETLINK_MSGBUFF_H__
9
10 #include <string.h>
11 #include <libmnl/libmnl.h>
12 #include <linux/netlink.h>
13 #include <linux/genetlink.h>
14
15 struct nl_context;
16
17 /**
18 * struct nl_msg_buff - message buffer abstraction
19 * @buff: pointer to buffer
20 * @size: total size of allocated buffer
21 * @left: remaining length current message end to end of buffer
22 * @nlhdr: pointer to netlink header of current message
23 * @genlhdr: pointer to genetlink header of current message
24 * @payload: pointer to message payload (after genetlink header)
25 */
26 struct nl_msg_buff {
27 char *buff;
28 unsigned int size;
29 unsigned int left;
30 struct nlmsghdr *nlhdr;
31 struct genlmsghdr *genlhdr;
32 void *payload;
33 };
34
35 void msgbuff_init(struct nl_msg_buff *msgbuff);
36 void msgbuff_done(struct nl_msg_buff *msgbuff);
37 int msgbuff_realloc(struct nl_msg_buff *msgbuff, unsigned int new_size);
38 int msgbuff_append(struct nl_msg_buff *dest, struct nl_msg_buff *src);
39
40 int __msg_init(struct nl_msg_buff *msgbuff, int family, int cmd,
41 unsigned int flags, int version);
42 int msg_init(struct nl_context *nlctx, struct nl_msg_buff *msgbuff, int cmd,
43 unsigned int flags);
44
45 bool ethnla_put(struct nl_msg_buff *msgbuff, uint16_t type, size_t len,
46 const void *data);
47 struct nlattr *ethnla_nest_start(struct nl_msg_buff *msgbuff, uint16_t type);
48 bool ethnla_fill_header(struct nl_msg_buff *msgbuff, uint16_t type,
49 const char *devname, uint32_t flags);
50
51 /* length of current message */
msgbuff_len(const struct nl_msg_buff * msgbuff)52 static inline unsigned int msgbuff_len(const struct nl_msg_buff *msgbuff)
53 {
54 return msgbuff->nlhdr->nlmsg_len;
55 }
56
57 /* reset message length to position returned by msgbuff_len() */
msgbuff_reset(const struct nl_msg_buff * msgbuff,unsigned int len)58 static inline void msgbuff_reset(const struct nl_msg_buff *msgbuff,
59 unsigned int len)
60 {
61 msgbuff->nlhdr->nlmsg_len = len;
62 }
63
64 /* put data wrappers */
65
ethnla_nest_end(struct nl_msg_buff * msgbuff,struct nlattr * nest)66 static inline void ethnla_nest_end(struct nl_msg_buff *msgbuff,
67 struct nlattr *nest)
68 {
69 mnl_attr_nest_end(msgbuff->nlhdr, nest);
70 }
71
ethnla_nest_cancel(struct nl_msg_buff * msgbuff,struct nlattr * nest)72 static inline void ethnla_nest_cancel(struct nl_msg_buff *msgbuff,
73 struct nlattr *nest)
74 {
75 mnl_attr_nest_cancel(msgbuff->nlhdr, nest);
76 }
77
ethnla_put_u32(struct nl_msg_buff * msgbuff,uint16_t type,uint32_t data)78 static inline bool ethnla_put_u32(struct nl_msg_buff *msgbuff, uint16_t type,
79 uint32_t data)
80 {
81 return ethnla_put(msgbuff, type, sizeof(uint32_t), &data);
82 }
83
ethnla_put_u16(struct nl_msg_buff * msgbuff,uint16_t type,uint16_t data)84 static inline bool ethnla_put_u16(struct nl_msg_buff *msgbuff, uint16_t type,
85 uint16_t data)
86 {
87 return ethnla_put(msgbuff, type, sizeof(uint16_t), &data);
88 }
89
ethnla_put_u8(struct nl_msg_buff * msgbuff,uint16_t type,uint8_t data)90 static inline bool ethnla_put_u8(struct nl_msg_buff *msgbuff, uint16_t type,
91 uint8_t data)
92 {
93 return ethnla_put(msgbuff, type, sizeof(uint8_t), &data);
94 }
95
ethnla_put_flag(struct nl_msg_buff * msgbuff,uint16_t type,bool val)96 static inline bool ethnla_put_flag(struct nl_msg_buff *msgbuff, uint16_t type,
97 bool val)
98 {
99 if (val)
100 return ethnla_put(msgbuff, type, 0, &val);
101 else
102 return false;
103 }
104
ethnla_put_bitfield32(struct nl_msg_buff * msgbuff,uint16_t type,uint32_t value,uint32_t selector)105 static inline bool ethnla_put_bitfield32(struct nl_msg_buff *msgbuff,
106 uint16_t type, uint32_t value,
107 uint32_t selector)
108 {
109 struct nla_bitfield32 val = {
110 .value = value,
111 .selector = selector,
112 };
113
114 return ethnla_put(msgbuff, type, sizeof(val), &val);
115 }
116
ethnla_put_strz(struct nl_msg_buff * msgbuff,uint16_t type,const char * data)117 static inline bool ethnla_put_strz(struct nl_msg_buff *msgbuff, uint16_t type,
118 const char *data)
119 {
120 return ethnla_put(msgbuff, type, strlen(data) + 1, data);
121 }
122
123 #endif /* ETHTOOL_NETLINK_MSGBUFF_H__ */
124