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064af421 | 1 | /* |
91496302 | 2 | * Copyright (c) 2008, 2009, 2010, 2011, 2013, 2015 Nicira, Inc. |
064af421 | 3 | * |
a14bc59f BP |
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: | |
064af421 | 7 | * |
a14bc59f BP |
8 | * http://www.apache.org/licenses/LICENSE-2.0 |
9 | * | |
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. | |
064af421 BP |
15 | */ |
16 | ||
17 | #ifndef NETLINK_H | |
18 | #define NETLINK_H 1 | |
19 | ||
2fe27d5a | 20 | /* Netlink message helpers. |
064af421 BP |
21 | * |
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". | |
25 | * | |
26 | * Netlink is not suitable for use in physical networks of heterogeneous | |
2fe27d5a BP |
27 | * machines because host byte order is used throughout. |
28 | * | |
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. | |
32 | */ | |
064af421 | 33 | |
b2befd5b | 34 | #include <sys/types.h> |
1b186808 | 35 | #include <netinet/in.h> |
064af421 | 36 | #include <stdbool.h> |
2fe27d5a | 37 | #include <stddef.h> |
064af421 | 38 | #include <stdint.h> |
7f8ca645 BP |
39 | #include "netlink-protocol.h" |
40 | #include "openvswitch/types.h" | |
064af421 BP |
41 | |
42 | struct ofpbuf; | |
064af421 BP |
43 | struct nlattr; |
44 | ||
064af421 BP |
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); | |
50 | ||
46d34fef | 51 | /* Appending and prepending headers and raw data. */ |
69123704 | 52 | void nl_msg_put_nlmsghdr(struct ofpbuf *, size_t expected_payload, |
064af421 | 53 | uint32_t type, uint32_t flags); |
69123704 BP |
54 | void nl_msg_put_genlmsghdr(struct ofpbuf *, size_t expected_payload, |
55 | int family, uint32_t flags, | |
064af421 BP |
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); | |
46d34fef BP |
59 | void nl_msg_push(struct ofpbuf *, const void *, size_t); |
60 | void *nl_msg_push_uninit(struct ofpbuf *, size_t); | |
064af421 BP |
61 | |
62 | /* Appending attributes. */ | |
63 | void *nl_msg_put_unspec_uninit(struct ofpbuf *, uint16_t type, size_t); | |
9ddf12cc | 64 | void *nl_msg_put_unspec_zero(struct ofpbuf *, uint16_t type, size_t); |
064af421 BP |
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); | |
ab79d262 | 71 | void nl_msg_put_u128(struct ofpbuf *, uint16_t type, ovs_u128 value); |
ee913f98 BP |
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); | |
ab79d262 | 75 | void nl_msg_put_be128(struct ofpbuf *, uint16_t type, ovs_be128 value); |
1b186808 JB |
76 | void nl_msg_put_in6_addr(struct ofpbuf *msg, uint16_t type, |
77 | const struct in6_addr *value); | |
4e022ec0 | 78 | void nl_msg_put_odp_port(struct ofpbuf *, uint16_t type, odp_port_t value); |
d787ad39 JS |
79 | void nl_msg_put_string__(struct ofpbuf *, uint16_t type, const char *value, |
80 | size_t len); | |
064af421 | 81 | void nl_msg_put_string(struct ofpbuf *, uint16_t type, const char *value); |
38a99756 BP |
82 | |
83 | size_t nl_msg_start_nested(struct ofpbuf *, uint16_t type); | |
84 | void nl_msg_end_nested(struct ofpbuf *, size_t offset); | |
ab5617db AZ |
85 | void nl_msg_cancel_nested(struct ofpbuf *, size_t offset); |
86 | bool nl_msg_end_non_empty_nested(struct ofpbuf *, size_t offset); | |
38a99756 BP |
87 | void nl_msg_put_nested(struct ofpbuf *, uint16_t type, |
88 | const void *data, size_t size); | |
974d6a6d | 89 | |
46d34fef BP |
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); | |
ab79d262 | 98 | void nl_msg_push_u128(struct ofpbuf *, uint16_t type, ovs_u128 value); |
46d34fef BP |
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); | |
ab79d262 | 102 | void nl_msg_push_be128(struct ofpbuf *, uint16_t type, ovs_be128 value); |
46d34fef BP |
103 | void nl_msg_push_string(struct ofpbuf *, uint16_t type, const char *value); |
104 | ||
974d6a6d BP |
105 | /* Separating buffers into individual messages. */ |
106 | struct nlmsghdr *nl_msg_next(struct ofpbuf *buffer, struct ofpbuf *msg); | |
3a706b33 BP |
107 | |
108 | /* Sizes of various attribute types, in bytes, including the attribute header | |
91496302 BP |
109 | * and padding. |
110 | * | |
111 | * A minimum-size attribute is 4 bytes long: 4 bytes of header, no bytes of | |
112 | * payload, no padding. | |
113 | * | |
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.) */ | |
3a706b33 BP |
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)) | |
ab79d262 | 122 | #define NL_A_U128_SIZE NL_ATTR_SIZE(sizeof(ovs_u128)) |
3a706b33 BP |
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)) | |
ab79d262 | 126 | #define NL_A_BE128_SIZE NL_ATTR_SIZE(sizeof(ovs_be128)) |
3a706b33 | 127 | #define NL_A_FLAG_SIZE NL_ATTR_SIZE(0) |
1b186808 | 128 | #define NL_A_IPV6_SIZE NL_ATTR_SIZE(sizeof(struct in6_addr)) |
542024c4 BP |
129 | |
130 | bool nl_attr_oversized(size_t payload_size); | |
064af421 BP |
131 | \f |
132 | /* Netlink attribute types. */ | |
133 | enum nl_attr_type | |
134 | { | |
135 | NL_A_NO_ATTR = 0, | |
136 | NL_A_UNSPEC, | |
137 | NL_A_U8, | |
138 | NL_A_U16, | |
18c58479 | 139 | NL_A_BE16 = NL_A_U16, |
064af421 | 140 | NL_A_U32, |
18c58479 | 141 | NL_A_BE32 = NL_A_U32, |
064af421 | 142 | NL_A_U64, |
18c58479 | 143 | NL_A_BE64 = NL_A_U64, |
ab79d262 BP |
144 | NL_A_U128, |
145 | NL_A_BE128 = NL_A_U128, | |
064af421 BP |
146 | NL_A_STRING, |
147 | NL_A_FLAG, | |
1b186808 | 148 | NL_A_IPV6, |
064af421 BP |
149 | NL_A_NESTED, |
150 | N_NL_ATTR_TYPES | |
151 | }; | |
152 | ||
7f8ca645 BP |
153 | /* Netlink attribute iteration. */ |
154 | static inline struct nlattr * | |
155 | nl_attr_next(const struct nlattr *nla) | |
156 | { | |
8bfc3c10 SS |
157 | return ALIGNED_CAST(struct nlattr *, |
158 | ((uint8_t *) nla + NLA_ALIGN(nla->nla_len))); | |
7f8ca645 BP |
159 | } |
160 | ||
161 | static inline bool | |
162 | nl_attr_is_valid(const struct nlattr *nla, size_t maxlen) | |
163 | { | |
164 | return (maxlen >= sizeof *nla | |
165 | && nla->nla_len >= sizeof *nla | |
b66b7b18 TG |
166 | && nla->nla_len <= maxlen); |
167 | } | |
168 | ||
169 | static inline size_t | |
170 | nl_attr_len_pad(const struct nlattr *nla, size_t maxlen) | |
171 | { | |
172 | size_t len = NLA_ALIGN(nla->nla_len); | |
173 | ||
174 | return len <= maxlen ? len : nla->nla_len; | |
7f8ca645 BP |
175 | } |
176 | ||
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); \ | |
b66b7b18 | 181 | (LEFT) -= nl_attr_len_pad(ITER, LEFT), (ITER) = nl_attr_next(ITER)) |
7f8ca645 BP |
182 | |
183 | ||
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 | |
b18fcf8e | 186 | * already been validated (e.g. with NL_ATTR_FOR_EACH). */ |
7f8ca645 BP |
187 | #define NL_ATTR_FOR_EACH_UNSAFE(ITER, LEFT, ATTRS, ATTRS_LEN) \ |
188 | for ((ITER) = (ATTRS), (LEFT) = (ATTRS_LEN); \ | |
189 | (LEFT) > 0; \ | |
b66b7b18 | 190 | (LEFT) -= nl_attr_len_pad(ITER, LEFT), (ITER) = nl_attr_next(ITER)) |
7f8ca645 | 191 | |
6d23c6f4 BP |
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)) | |
197 | ||
064af421 | 198 | /* Netlink attribute parsing. */ |
7c624478 | 199 | int nl_attr_type(const struct nlattr *); |
064af421 BP |
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 *); | |
ab79d262 | 208 | ovs_u128 nl_attr_get_u128(const struct nlattr *); |
ee913f98 BP |
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 *); | |
ab79d262 | 212 | ovs_be128 nl_attr_get_be128(const struct nlattr *); |
1b186808 | 213 | struct in6_addr nl_attr_get_in6_addr(const struct nlattr *nla); |
4e022ec0 | 214 | odp_port_t nl_attr_get_odp_port(const struct nlattr *); |
064af421 | 215 | const char *nl_attr_get_string(const struct nlattr *); |
25eeae6a | 216 | void nl_attr_get_nested(const struct nlattr *, struct ofpbuf *); |
064af421 BP |
217 | |
218 | /* Netlink attribute policy. | |
219 | * | |
220 | * Specifies how to parse a single attribute from a Netlink message payload. | |
221 | */ | |
222 | struct nl_policy | |
223 | { | |
224 | enum nl_attr_type type; | |
225 | size_t min_len, max_len; | |
226 | bool optional; | |
227 | }; | |
228 | ||
f7df9823 BP |
229 | #define NL_POLICY_FOR(TYPE) \ |
230 | .type = NL_A_UNSPEC, .min_len = sizeof(TYPE), .max_len = sizeof(TYPE) | |
231 | ||
be3330a6 BP |
232 | bool nl_attr_validate(const struct nlattr *, const struct nl_policy *); |
233 | ||
064af421 BP |
234 | bool nl_policy_parse(const struct ofpbuf *, size_t offset, |
235 | const struct nl_policy[], | |
236 | struct nlattr *[], size_t n_attrs); | |
25eeae6a BP |
237 | bool nl_parse_nested(const struct nlattr *, const struct nl_policy[], |
238 | struct nlattr *[], size_t n_attrs); | |
064af421 | 239 | |
b18fcf8e BP |
240 | const struct nlattr *nl_attr_find(const struct ofpbuf *, size_t hdr_len, |
241 | uint16_t type); | |
242 | const struct nlattr *nl_attr_find_nested(const struct nlattr *, uint16_t type); | |
0b6c119b JG |
243 | const struct nlattr *nl_attr_find__(const struct nlattr *attrs, size_t size, |
244 | uint16_t type); | |
b18fcf8e | 245 | |
064af421 | 246 | #endif /* netlink.h */ |