]>
git.proxmox.com Git - mirror_ovs.git/blob - lib/netlink.h
2 * Copyright (c) 2008, 2009, 2010, 2011, 2013, 2015 Nicira, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
20 /* Netlink message helpers.
22 * Netlink is a datagram-based network protocol primarily for communication
23 * between user processes and the kernel, and mainly on Linux. Netlink is
24 * specified in RFC 3549, "Linux Netlink as an IP Services Protocol".
26 * Netlink is not suitable for use in physical networks of heterogeneous
27 * machines because host byte order is used throughout.
29 * This header file defines helper functions for working with Netlink messages.
30 * For Netlink protocol definitions, see netlink-protocol.h. For
31 * Linux-specific definitions for Netlink sockets, see netlink-socket.h.
34 #include <sys/types.h>
35 #include <netinet/in.h>
39 #include "netlink-protocol.h"
40 #include "openvswitch/types.h"
45 /* Accessing headers and data. */
46 struct nlmsghdr
*nl_msg_nlmsghdr(const struct ofpbuf
*);
47 struct genlmsghdr
*nl_msg_genlmsghdr(const struct ofpbuf
*);
48 bool nl_msg_nlmsgerr(const struct ofpbuf
*, int *error
);
49 void nl_msg_reserve(struct ofpbuf
*, size_t);
51 /* Appending and prepending headers and raw data. */
52 void nl_msg_put_nlmsghdr(struct ofpbuf
*, size_t expected_payload
,
53 uint32_t type
, uint32_t flags
);
54 void nl_msg_put_genlmsghdr(struct ofpbuf
*, size_t expected_payload
,
55 int family
, uint32_t flags
,
56 uint8_t cmd
, uint8_t version
);
57 void nl_msg_put(struct ofpbuf
*, const void *, size_t);
58 void *nl_msg_put_uninit(struct ofpbuf
*, size_t);
59 void nl_msg_push(struct ofpbuf
*, const void *, size_t);
60 void *nl_msg_push_uninit(struct ofpbuf
*, size_t);
62 /* Appending attributes. */
63 void *nl_msg_put_unspec_uninit(struct ofpbuf
*, uint16_t type
, size_t);
64 void *nl_msg_put_unspec_zero(struct ofpbuf
*, uint16_t type
, size_t);
65 void nl_msg_put_unspec(struct ofpbuf
*, uint16_t type
, const void *, size_t);
66 void nl_msg_put_flag(struct ofpbuf
*, uint16_t type
);
67 void nl_msg_put_u8(struct ofpbuf
*, uint16_t type
, uint8_t value
);
68 void nl_msg_put_u16(struct ofpbuf
*, uint16_t type
, uint16_t value
);
69 void nl_msg_put_u32(struct ofpbuf
*, uint16_t type
, uint32_t value
);
70 void nl_msg_put_u64(struct ofpbuf
*, uint16_t type
, uint64_t value
);
71 void nl_msg_put_u128(struct ofpbuf
*, uint16_t type
, ovs_u128 value
);
72 void nl_msg_put_be16(struct ofpbuf
*, uint16_t type
, ovs_be16 value
);
73 void nl_msg_put_be32(struct ofpbuf
*, uint16_t type
, ovs_be32 value
);
74 void nl_msg_put_be64(struct ofpbuf
*, uint16_t type
, ovs_be64 value
);
75 void nl_msg_put_be128(struct ofpbuf
*, uint16_t type
, ovs_be128 value
);
76 void nl_msg_put_in6_addr(struct ofpbuf
*msg
, uint16_t type
,
77 const struct in6_addr
*value
);
78 void nl_msg_put_odp_port(struct ofpbuf
*, uint16_t type
, odp_port_t value
);
79 void nl_msg_put_string__(struct ofpbuf
*, uint16_t type
, const char *value
,
81 void nl_msg_put_string(struct ofpbuf
*, uint16_t type
, const char *value
);
83 size_t nl_msg_start_nested(struct ofpbuf
*, uint16_t type
);
84 void nl_msg_end_nested(struct ofpbuf
*, size_t offset
);
85 void nl_msg_cancel_nested(struct ofpbuf
*, size_t offset
);
86 bool nl_msg_end_non_empty_nested(struct ofpbuf
*, size_t offset
);
87 void nl_msg_put_nested(struct ofpbuf
*, uint16_t type
,
88 const void *data
, size_t size
);
90 /* Prepending attributes. */
91 void *nl_msg_push_unspec_uninit(struct ofpbuf
*, uint16_t type
, size_t);
92 void nl_msg_push_unspec(struct ofpbuf
*, uint16_t type
, const void *, size_t);
93 void nl_msg_push_flag(struct ofpbuf
*, uint16_t type
);
94 void nl_msg_push_u8(struct ofpbuf
*, uint16_t type
, uint8_t value
);
95 void nl_msg_push_u16(struct ofpbuf
*, uint16_t type
, uint16_t value
);
96 void nl_msg_push_u32(struct ofpbuf
*, uint16_t type
, uint32_t value
);
97 void nl_msg_push_u64(struct ofpbuf
*, uint16_t type
, uint64_t value
);
98 void nl_msg_push_u128(struct ofpbuf
*, uint16_t type
, ovs_u128 value
);
99 void nl_msg_push_be16(struct ofpbuf
*, uint16_t type
, ovs_be16 value
);
100 void nl_msg_push_be32(struct ofpbuf
*, uint16_t type
, ovs_be32 value
);
101 void nl_msg_push_be64(struct ofpbuf
*, uint16_t type
, ovs_be64 value
);
102 void nl_msg_push_be128(struct ofpbuf
*, uint16_t type
, ovs_be128 value
);
103 void nl_msg_push_string(struct ofpbuf
*, uint16_t type
, const char *value
);
105 /* Separating buffers into individual messages. */
106 struct nlmsghdr
*nl_msg_next(struct ofpbuf
*buffer
, struct ofpbuf
*msg
);
108 /* Sizes of various attribute types, in bytes, including the attribute header
111 * A minimum-size attribute is 4 bytes long: 4 bytes of header, no bytes of
112 * payload, no padding.
114 * A maximum-size attribute is 65536 bytes long: 4 bytes of header, 65531 bytes
115 * of payload, 1 byte of padding. (Thus, NL_ATTR_SIZE() of a maximum length
116 * attribute payload does not fit in 16 bits.) */
117 #define NL_ATTR_SIZE(PAYLOAD_SIZE) (NLA_HDRLEN + NLA_ALIGN(PAYLOAD_SIZE))
118 #define NL_A_U8_SIZE NL_ATTR_SIZE(sizeof(uint8_t))
119 #define NL_A_U16_SIZE NL_ATTR_SIZE(sizeof(uint16_t))
120 #define NL_A_U32_SIZE NL_ATTR_SIZE(sizeof(uint32_t))
121 #define NL_A_U64_SIZE NL_ATTR_SIZE(sizeof(uint64_t))
122 #define NL_A_U128_SIZE NL_ATTR_SIZE(sizeof(ovs_u128))
123 #define NL_A_BE16_SIZE NL_ATTR_SIZE(sizeof(ovs_be16))
124 #define NL_A_BE32_SIZE NL_ATTR_SIZE(sizeof(ovs_be32))
125 #define NL_A_BE64_SIZE NL_ATTR_SIZE(sizeof(ovs_be64))
126 #define NL_A_BE128_SIZE NL_ATTR_SIZE(sizeof(ovs_be128))
127 #define NL_A_FLAG_SIZE NL_ATTR_SIZE(0)
128 #define NL_A_IPV6_SIZE NL_ATTR_SIZE(sizeof(struct in6_addr))
130 bool nl_attr_oversized(size_t payload_size
);
132 /* Netlink attribute types. */
139 NL_A_BE16
= NL_A_U16
,
141 NL_A_BE32
= NL_A_U32
,
143 NL_A_BE64
= NL_A_U64
,
145 NL_A_BE128
= NL_A_U128
,
153 /* Netlink attribute iteration. */
154 static inline struct nlattr
*
155 nl_attr_next(const struct nlattr
*nla
)
157 return ALIGNED_CAST(struct nlattr
*,
158 ((uint8_t *) nla
+ NLA_ALIGN(nla
->nla_len
)));
162 nl_attr_is_valid(const struct nlattr
*nla
, size_t maxlen
)
164 return (maxlen
>= sizeof *nla
165 && nla
->nla_len
>= sizeof *nla
166 && nla
->nla_len
<= maxlen
);
170 nl_attr_len_pad(const struct nlattr
*nla
, size_t maxlen
)
172 size_t len
= NLA_ALIGN(nla
->nla_len
);
174 return len
<= maxlen
? len
: nla
->nla_len
;
177 /* This macro is careful to check for attributes with bad lengths. */
178 #define NL_ATTR_FOR_EACH(ITER, LEFT, ATTRS, ATTRS_LEN) \
179 for ((ITER) = (ATTRS), (LEFT) = (ATTRS_LEN); \
180 nl_attr_is_valid(ITER, LEFT); \
181 (LEFT) -= nl_attr_len_pad(ITER, LEFT), (ITER) = nl_attr_next(ITER))
184 /* This macro does not check for attributes with bad lengths. It should only
185 * be used with messages from trusted sources or with messages that have
186 * already been validated (e.g. with NL_ATTR_FOR_EACH). */
187 #define NL_ATTR_FOR_EACH_UNSAFE(ITER, LEFT, ATTRS, ATTRS_LEN) \
188 for ((ITER) = (ATTRS), (LEFT) = (ATTRS_LEN); \
190 (LEFT) -= nl_attr_len_pad(ITER, LEFT), (ITER) = nl_attr_next(ITER))
192 /* These variants are convenient for iterating nested attributes. */
193 #define NL_NESTED_FOR_EACH(ITER, LEFT, A) \
194 NL_ATTR_FOR_EACH(ITER, LEFT, nl_attr_get(A), nl_attr_get_size(A))
195 #define NL_NESTED_FOR_EACH_UNSAFE(ITER, LEFT, A) \
196 NL_ATTR_FOR_EACH_UNSAFE(ITER, LEFT, nl_attr_get(A), nl_attr_get_size(A))
198 /* Netlink attribute parsing. */
199 int nl_attr_type(const struct nlattr
*);
200 const void *nl_attr_get(const struct nlattr
*);
201 size_t nl_attr_get_size(const struct nlattr
*);
202 const void *nl_attr_get_unspec(const struct nlattr
*, size_t size
);
203 bool nl_attr_get_flag(const struct nlattr
*);
204 uint8_t nl_attr_get_u8(const struct nlattr
*);
205 uint16_t nl_attr_get_u16(const struct nlattr
*);
206 uint32_t nl_attr_get_u32(const struct nlattr
*);
207 uint64_t nl_attr_get_u64(const struct nlattr
*);
208 ovs_u128
nl_attr_get_u128(const struct nlattr
*);
209 ovs_be16
nl_attr_get_be16(const struct nlattr
*);
210 ovs_be32
nl_attr_get_be32(const struct nlattr
*);
211 ovs_be64
nl_attr_get_be64(const struct nlattr
*);
212 ovs_be128
nl_attr_get_be128(const struct nlattr
*);
213 struct in6_addr
nl_attr_get_in6_addr(const struct nlattr
*nla
);
214 odp_port_t
nl_attr_get_odp_port(const struct nlattr
*);
215 const char *nl_attr_get_string(const struct nlattr
*);
216 void nl_attr_get_nested(const struct nlattr
*, struct ofpbuf
*);
218 /* Netlink attribute policy.
220 * Specifies how to parse a single attribute from a Netlink message payload.
224 enum nl_attr_type type
;
225 size_t min_len
, max_len
;
229 #define NL_POLICY_FOR(TYPE) \
230 .type = NL_A_UNSPEC, .min_len = sizeof(TYPE), .max_len = sizeof(TYPE)
232 bool nl_attr_validate(const struct nlattr
*, const struct nl_policy
*);
234 bool nl_policy_parse(const struct ofpbuf
*, size_t offset
,
235 const struct nl_policy
[],
236 struct nlattr
*[], size_t n_attrs
);
237 bool nl_parse_nested(const struct nlattr
*, const struct nl_policy
[],
238 struct nlattr
*[], size_t n_attrs
);
240 const struct nlattr
*nl_attr_find(const struct ofpbuf
*, size_t hdr_len
,
242 const struct nlattr
*nl_attr_find_nested(const struct nlattr
*, uint16_t type
);
243 const struct nlattr
*nl_attr_find__(const struct nlattr
*attrs
, size_t size
,
246 #endif /* netlink.h */