1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2021 Ng Peng Nam Sean 5 * Copyright (c) 2022 Alexander V. Chernikov <melifaro@FreeBSD.org> 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 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. 15 * 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 26 * SUCH DAMAGE. 27 */ 28 29 #ifndef _NETLINK_NETLINK_MESSAGE_WRITER_H_ 30 #define _NETLINK_NETLINK_MESSAGE_WRITER_H_ 31 32 #ifdef _KERNEL 33 34 #include <netinet/in.h> 35 36 /* 37 * It is not meant to be included directly 38 */ 39 40 struct nl_buf; 41 struct nl_writer; 42 typedef bool nl_writer_cb(struct nl_writer *nw); 43 44 struct nl_writer { 45 struct nl_buf *buf; /* Underlying storage pointer */ 46 struct nlmsghdr *hdr; /* Pointer to the currently-filled msg */ 47 nl_writer_cb *cb; /* Callback to flush data */ 48 union { 49 struct nlpcb *nlp; 50 struct { 51 uint16_t proto; 52 uint16_t id; 53 } group; 54 }; 55 u_int num_messages; /* Number of messages in the buffer */ 56 int malloc_flag; /* M_WAITOK or M_NOWAIT */ 57 bool ignore_limit; /* If true, ignores RCVBUF limit */ 58 bool enomem; /* True if ENOMEM occured */ 59 bool suppress_ack; /* If true, don't send NLMSG_ERR */ 60 }; 61 62 #define NLMSG_SMALL 128 63 #define NLMSG_LARGE 2048 64 65 /* Message and attribute writing */ 66 #if defined(NETLINK) || defined(NETLINK_MODULE) 67 /* Provide optimized calls to the functions inside the same linking unit */ 68 69 bool _nlmsg_get_unicast_writer(struct nl_writer *nw, int expected_size, struct nlpcb *nlp); 70 bool _nlmsg_get_group_writer(struct nl_writer *nw, int expected_size, int proto, int group_id); 71 bool _nlmsg_flush(struct nl_writer *nw); 72 void _nlmsg_ignore_limit(struct nl_writer *nw); 73 74 bool _nlmsg_refill_buffer(struct nl_writer *nw, u_int required_len); 75 bool _nlmsg_add(struct nl_writer *nw, uint32_t portid, uint32_t seq, uint16_t type, 76 uint16_t flags, uint32_t len); 77 bool _nlmsg_end(struct nl_writer *nw); 78 void _nlmsg_abort(struct nl_writer *nw); 79 80 bool _nlmsg_end_dump(struct nl_writer *nw, int error, struct nlmsghdr *hdr); 81 82 83 static inline bool 84 nlmsg_get_unicast_writer(struct nl_writer *nw, int expected_size, struct nlpcb *nlp) 85 { 86 return (_nlmsg_get_unicast_writer(nw, expected_size, nlp)); 87 } 88 89 static inline bool 90 nlmsg_get_group_writer(struct nl_writer *nw, int expected_size, int proto, int group_id) 91 { 92 return (_nlmsg_get_group_writer(nw, expected_size, proto, group_id)); 93 } 94 95 static inline bool 96 nlmsg_flush(struct nl_writer *nw) 97 { 98 return (_nlmsg_flush(nw)); 99 } 100 101 static inline void 102 nlmsg_ignore_limit(struct nl_writer *nw) 103 { 104 _nlmsg_ignore_limit(nw); 105 } 106 107 static inline bool 108 nlmsg_refill_buffer(struct nl_writer *nw, int required_size) 109 { 110 return (_nlmsg_refill_buffer(nw, required_size)); 111 } 112 113 static inline bool 114 nlmsg_add(struct nl_writer *nw, uint32_t portid, uint32_t seq, uint16_t type, 115 uint16_t flags, uint32_t len) 116 { 117 return (_nlmsg_add(nw, portid, seq, type, flags, len)); 118 } 119 120 static inline bool 121 nlmsg_end(struct nl_writer *nw) 122 { 123 return (_nlmsg_end(nw)); 124 } 125 126 static inline void 127 nlmsg_abort(struct nl_writer *nw) 128 { 129 return (_nlmsg_abort(nw)); 130 } 131 132 static inline bool 133 nlmsg_end_dump(struct nl_writer *nw, int error, struct nlmsghdr *hdr) 134 { 135 return (_nlmsg_end_dump(nw, error, hdr)); 136 } 137 138 #else 139 /* Provide access to the functions via netlink_glue.c */ 140 141 bool nlmsg_get_unicast_writer(struct nl_writer *nw, int expected_size, struct nlpcb *nlp); 142 bool nlmsg_get_group_writer(struct nl_writer *nw, int expected_size, int proto, int group_id); 143 bool nlmsg_get_chain_writer(struct nl_writer *nw, int expected_size, struct mbuf **pm); 144 bool nlmsg_flush(struct nl_writer *nw); 145 void nlmsg_ignore_limit(struct nl_writer *nw); 146 147 bool nlmsg_refill_buffer(struct nl_writer *nw, int required_size); 148 bool nlmsg_add(struct nl_writer *nw, uint32_t portid, uint32_t seq, uint16_t type, 149 uint16_t flags, uint32_t len); 150 bool nlmsg_end(struct nl_writer *nw); 151 void nlmsg_abort(struct nl_writer *nw); 152 153 bool nlmsg_end_dump(struct nl_writer *nw, int error, struct nlmsghdr *hdr); 154 155 #endif /* defined(NETLINK) || defined(NETLINK_MODULE) */ 156 157 static inline bool 158 nlmsg_reply(struct nl_writer *nw, const struct nlmsghdr *hdr, int payload_len) 159 { 160 return (nlmsg_add(nw, hdr->nlmsg_pid, hdr->nlmsg_seq, hdr->nlmsg_type, 161 hdr->nlmsg_flags, payload_len)); 162 } 163 164 /* 165 * KPI similar to mtodo(): 166 * current (uncompleted) header is guaranteed to be contiguous, 167 * but can be reallocated, thus pointers may need to be readjusted. 168 */ 169 u_int nlattr_save_offset(const struct nl_writer *nw); 170 171 static inline void * 172 _nlattr_restore_offset(const struct nl_writer *nw, int off) 173 { 174 return ((void *)((char *)nw->hdr + off)); 175 } 176 #define nlattr_restore_offset(_ns, _off, _t) ((_t *)_nlattr_restore_offset(_ns, _off)) 177 178 static inline void 179 nlattr_set_len(const struct nl_writer *nw, int off) 180 { 181 struct nlattr *nla = nlattr_restore_offset(nw, off, struct nlattr); 182 nla->nla_len = nlattr_save_offset(nw) - off; 183 } 184 185 void *nlmsg_reserve_data_raw(struct nl_writer *nw, size_t sz); 186 #define nlmsg_reserve_object(_ns, _t) ((_t *)nlmsg_reserve_data_raw(_ns, sizeof(_t))) 187 #define nlmsg_reserve_data(_ns, _sz, _t) ((_t *)nlmsg_reserve_data_raw(_ns, _sz)) 188 189 static inline int 190 nlattr_add_nested(struct nl_writer *nw, uint16_t nla_type) 191 { 192 int off = nlattr_save_offset(nw); 193 struct nlattr *nla = nlmsg_reserve_data(nw, sizeof(struct nlattr), struct nlattr); 194 if (__predict_false(nla == NULL)) 195 return (0); 196 nla->nla_type = nla_type; 197 return (off); 198 } 199 200 static inline void * 201 _nlmsg_reserve_attr(struct nl_writer *nw, uint16_t nla_type, uint16_t sz) 202 { 203 sz += sizeof(struct nlattr); 204 205 struct nlattr *nla = nlmsg_reserve_data(nw, sz, struct nlattr); 206 if (__predict_false(nla == NULL)) 207 return (NULL); 208 nla->nla_type = nla_type; 209 nla->nla_len = sz; 210 211 return ((void *)(nla + 1)); 212 } 213 #define nlmsg_reserve_attr(_ns, _at, _t) ((_t *)_nlmsg_reserve_attr(_ns, _at, NLA_ALIGN(sizeof(_t)))) 214 215 bool nlattr_add(struct nl_writer *nw, int attr_type, int attr_len, 216 const void *data); 217 218 static inline bool 219 nlattr_add_raw(struct nl_writer *nw, const struct nlattr *nla_src) 220 { 221 int attr_len = nla_src->nla_len - sizeof(struct nlattr); 222 223 MPASS(attr_len >= 0); 224 225 return (nlattr_add(nw, nla_src->nla_type, attr_len, (const void *)(nla_src + 1))); 226 } 227 228 static inline bool 229 nlattr_add_u8(struct nl_writer *nw, int attrtype, uint8_t value) 230 { 231 return (nlattr_add(nw, attrtype, sizeof(uint8_t), &value)); 232 } 233 234 static inline bool 235 nlattr_add_u16(struct nl_writer *nw, int attrtype, uint16_t value) 236 { 237 return (nlattr_add(nw, attrtype, sizeof(uint16_t), &value)); 238 } 239 240 static inline bool 241 nlattr_add_u32(struct nl_writer *nw, int attrtype, uint32_t value) 242 { 243 return (nlattr_add(nw, attrtype, sizeof(uint32_t), &value)); 244 } 245 246 static inline bool 247 nlattr_add_u64(struct nl_writer *nw, int attrtype, uint64_t value) 248 { 249 return (nlattr_add(nw, attrtype, sizeof(uint64_t), &value)); 250 } 251 252 static inline bool 253 nlattr_add_s8(struct nl_writer *nw, int attrtype, int8_t value) 254 { 255 return (nlattr_add(nw, attrtype, sizeof(int8_t), &value)); 256 } 257 258 static inline bool 259 nlattr_add_s16(struct nl_writer *nw, int attrtype, int16_t value) 260 { 261 return (nlattr_add(nw, attrtype, sizeof(int16_t), &value)); 262 } 263 264 static inline bool 265 nlattr_add_s32(struct nl_writer *nw, int attrtype, int32_t value) 266 { 267 return (nlattr_add(nw, attrtype, sizeof(int32_t), &value)); 268 } 269 270 static inline bool 271 nlattr_add_s64(struct nl_writer *nw, int attrtype, int64_t value) 272 { 273 return (nlattr_add(nw, attrtype, sizeof(int64_t), &value)); 274 } 275 276 static inline bool 277 nlattr_add_flag(struct nl_writer *nw, int attrtype) 278 { 279 return (nlattr_add(nw, attrtype, 0, NULL)); 280 } 281 282 static inline bool 283 nlattr_add_string(struct nl_writer *nw, int attrtype, const char *str) 284 { 285 return (nlattr_add(nw, attrtype, strlen(str) + 1, str)); 286 } 287 288 static inline bool 289 nlattr_add_in_addr(struct nl_writer *nw, int attrtype, const struct in_addr *in) 290 { 291 return (nlattr_add(nw, attrtype, sizeof(*in), in)); 292 } 293 294 static inline bool 295 nlattr_add_in6_addr(struct nl_writer *nw, int attrtype, const struct in6_addr *in6) 296 { 297 return (nlattr_add(nw, attrtype, sizeof(*in6), in6)); 298 } 299 #endif 300 #endif 301