2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2021 Ng Peng Nam Sean
5 * Copyright (c) 2022 Alexander V. Chernikov <melifaro@FreeBSD.org>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 #ifndef _NETLINK_NETLINK_MESSAGE_WRITER_H_
30 #define _NETLINK_NETLINK_MESSAGE_WRITER_H_
34 * It is not meant to be included directly
39 typedef bool nl_writer_cb(struct nl_writer *nw, void *buf, int buflen, int cnt);
42 int alloc_len; /* allocated buffer length */
43 int offset; /* offset from the start of the buffer */
44 struct nlmsghdr *hdr; /* Pointer to the currently-filled msg */
45 char *data; /* pointer to the contiguous storage */
46 void *_storage; /* Underlying storage pointer */
47 nl_writer_cb *cb; /* Callback to flush data */
49 void *arg_ptr; /* Callback argument as pointer */
50 uint64_t arg_uint; /* Callback argument as int */
52 int num_messages; /* Number of messages in the buffer */
53 int malloc_flag; /* M_WAITOK or M_NOWAIT */
54 uint8_t writer_type; /* NS_WRITER_TYPE_* */
55 uint8_t writer_target; /* NS_WRITER_TARGET_* */
56 bool ignore_limit; /* If true, ignores RCVBUF limit */
57 bool enomem; /* True if ENOMEM occured */
58 bool suppress_ack; /* If true, don't send NLMSG_ERR */
60 #define NS_WRITER_TARGET_SOCKET 0
61 #define NS_WRITER_TARGET_GROUP 1
62 #define NS_WRITER_TARGET_CHAIN 2
64 #define NS_WRITER_TYPE_MBUF 0
65 #define NS_WRITER_TYPE_BUF 1
66 #define NS_WRITER_TYPE_LBUF 2
67 #define NS_WRITER_TYPE_MBUFC 3
70 #define NLMSG_SMALL 128
71 #define NLMSG_LARGE 2048
73 /* Message and attribute writing */
76 bool nlmsg_get_unicast_writer(struct nl_writer *nw, int expected_size, struct nlpcb *nlp);
77 bool nlmsg_get_group_writer(struct nl_writer *nw, int expected_size, int proto, int group_id);
78 bool nlmsg_get_chain_writer(struct nl_writer *nw, int expected_size, struct mbuf **pm);
79 bool nlmsg_flush(struct nl_writer *nw);
80 void nlmsg_ignore_limit(struct nl_writer *nw);
82 bool nlmsg_refill_buffer(struct nl_writer *nw, int required_size);
83 bool nlmsg_add(struct nl_writer *nw, uint32_t portid, uint32_t seq, uint16_t type,
84 uint16_t flags, uint32_t len);
85 bool nlmsg_end(struct nl_writer *nw);
86 void nlmsg_abort(struct nl_writer *nw);
88 bool nlmsg_end_dump(struct nl_writer *nw, int error, struct nlmsghdr *hdr);
91 nlmsg_reply(struct nl_writer *nw, const struct nlmsghdr *hdr, int payload_len)
93 return (nlmsg_add(nw, hdr->nlmsg_pid, hdr->nlmsg_seq, hdr->nlmsg_type,
94 hdr->nlmsg_flags, payload_len));
97 #define nlmsg_data(_hdr) ((void *)((_hdr) + 1))
100 * KPI similar to mtodo():
101 * current (uncompleted) header is guaranteed to be contiguous,
102 * but can be reallocated, thus pointers may need to be readjusted.
105 nlattr_save_offset(const struct nl_writer *nw)
107 return (nw->offset - ((char *)nw->hdr - nw->data));
111 _nlattr_restore_offset(const struct nl_writer *nw, int off)
113 return ((void *)((char *)nw->hdr + off));
115 #define nlattr_restore_offset(_ns, _off, _t) ((_t *)_nlattr_restore_offset(_ns, _off))
118 nlattr_set_len(const struct nl_writer *nw, int off)
120 struct nlattr *nla = nlattr_restore_offset(nw, off, struct nlattr);
121 nla->nla_len = nlattr_save_offset(nw) - off;
125 nlmsg_reserve_data_raw(struct nl_writer *nw, size_t sz)
127 if (__predict_false(nw->offset + NETLINK_ALIGN(sz) > nw->alloc_len)) {
128 if (!nlmsg_refill_buffer(nw, NETLINK_ALIGN(sz)))
132 void *data_ptr = &nw->data[nw->offset];
133 nw->offset += NLMSG_ALIGN(sz);
137 #define nlmsg_reserve_object(_ns, _t) ((_t *)nlmsg_reserve_data_raw(_ns, NLA_ALIGN(sizeof(_t))))
138 #define nlmsg_reserve_data(_ns, _sz, _t) ((_t *)nlmsg_reserve_data_raw(_ns, _sz))
141 nlattr_add_nested(struct nl_writer *nw, uint16_t nla_type)
143 int off = nlattr_save_offset(nw);
144 struct nlattr *nla = nlmsg_reserve_data(nw, sizeof(struct nlattr), struct nlattr);
145 if (__predict_false(nla == NULL))
147 nla->nla_type = nla_type;
152 _nlmsg_reserve_attr(struct nl_writer *nw, uint16_t nla_type, uint16_t sz)
154 sz += sizeof(struct nlattr);
156 struct nlattr *nla = nlmsg_reserve_data(nw, sz, struct nlattr);
157 if (__predict_false(nla == NULL))
159 nla->nla_type = nla_type;
162 return ((void *)(nla + 1));
164 #define nlmsg_reserve_attr(_ns, _at, _t) ((_t *)_nlmsg_reserve_attr(_ns, _at, NLA_ALIGN(sizeof(_t))))
167 nlattr_add(struct nl_writer *nw, int attr_type, int attr_len, const void *data)
169 int required_len = NLA_ALIGN(attr_len + sizeof(struct nlattr));
171 if (__predict_false(nw->offset + required_len > nw->alloc_len)) {
172 if (!nlmsg_refill_buffer(nw, required_len))
176 struct nlattr *nla = (struct nlattr *)(&nw->data[nw->offset]);
178 nla->nla_len = attr_len + sizeof(struct nlattr);
179 nla->nla_type = attr_type;
181 if ((attr_len % 4) != 0) {
182 /* clear padding bytes */
183 bzero((char *)nla + required_len - 4, 4);
185 memcpy((nla + 1), data, attr_len);
187 nw->offset += required_len;
192 nlattr_add_u8(struct nl_writer *nw, int attrtype, uint8_t value)
194 return (nlattr_add(nw, attrtype, sizeof(uint8_t), &value));
198 nlattr_add_u16(struct nl_writer *nw, int attrtype, uint16_t value)
200 return (nlattr_add(nw, attrtype, sizeof(uint16_t), &value));
204 nlattr_add_u32(struct nl_writer *nw, int attrtype, uint32_t value)
206 return (nlattr_add(nw, attrtype, sizeof(uint32_t), &value));
210 nlattr_add_u64(struct nl_writer *nw, int attrtype, uint64_t value)
212 return (nlattr_add(nw, attrtype, sizeof(uint64_t), &value));
216 nlattr_add_s8(struct nl_writer *nw, int attrtype, int8_t value)
218 return (nlattr_add(nw, attrtype, sizeof(int8_t), &value));
222 nlattr_add_s16(struct nl_writer *nw, int attrtype, int16_t value)
224 return (nlattr_add(nw, attrtype, sizeof(int16_t), &value));
228 nlattr_add_s32(struct nl_writer *nw, int attrtype, int32_t value)
230 return (nlattr_add(nw, attrtype, sizeof(int32_t), &value));
234 nlattr_add_s64(struct nl_writer *nw, int attrtype, int64_t value)
236 return (nlattr_add(nw, attrtype, sizeof(int64_t), &value));
240 nlattr_add_flag(struct nl_writer *nw, int attrtype)
242 return (nlattr_add(nw, attrtype, 0, NULL));
246 nlattr_add_string(struct nl_writer *nw, int attrtype, const char *str)
248 return (nlattr_add(nw, attrtype, strlen(str) + 1, str));