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 _nl_writer_unicast(struct nl_writer *, size_t, struct nlpcb *nlp, bool); 70 bool _nl_writer_group(struct nl_writer *, size_t, uint16_t, uint16_t, bool); 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, size_t required_len); 75 bool _nlmsg_add(struct nl_writer *nw, uint32_t portid, uint32_t seq, 76 uint16_t type, 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 nl_writer_unicast(struct nl_writer *nw, size_t size, struct nlpcb *nlp, 85 bool waitok) 86 { 87 return (_nl_writer_unicast(nw, size, nlp, waitok)); 88 } 89 90 static inline bool 91 nl_writer_group(struct nl_writer *nw, size_t size, uint16_t proto, 92 uint16_t group_id, bool waitok) 93 { 94 return (_nl_writer_group(nw, size, proto, group_id, waitok)); 95 } 96 97 static inline bool 98 nlmsg_flush(struct nl_writer *nw) 99 { 100 return (_nlmsg_flush(nw)); 101 } 102 103 static inline void 104 nlmsg_ignore_limit(struct nl_writer *nw) 105 { 106 _nlmsg_ignore_limit(nw); 107 } 108 109 static inline bool 110 nlmsg_refill_buffer(struct nl_writer *nw, size_t required_size) 111 { 112 return (_nlmsg_refill_buffer(nw, required_size)); 113 } 114 115 static inline bool 116 nlmsg_add(struct nl_writer *nw, uint32_t portid, uint32_t seq, uint16_t type, 117 uint16_t flags, uint32_t len) 118 { 119 return (_nlmsg_add(nw, portid, seq, type, flags, len)); 120 } 121 122 static inline bool 123 nlmsg_end(struct nl_writer *nw) 124 { 125 return (_nlmsg_end(nw)); 126 } 127 128 static inline void 129 nlmsg_abort(struct nl_writer *nw) 130 { 131 return (_nlmsg_abort(nw)); 132 } 133 134 static inline bool 135 nlmsg_end_dump(struct nl_writer *nw, int error, struct nlmsghdr *hdr) 136 { 137 return (_nlmsg_end_dump(nw, error, hdr)); 138 } 139 140 #else 141 /* Provide access to the functions via netlink_glue.c */ 142 143 bool nl_writer_unicast(struct nl_writer *, size_t, struct nlpcb *, bool waitok); 144 bool nl_writer_group(struct nl_writer *, size_t, uint16_t, uint16_t, 145 bool waitok); 146 bool nlmsg_flush(struct nl_writer *nw); 147 void nlmsg_ignore_limit(struct nl_writer *nw); 148 149 bool nlmsg_refill_buffer(struct nl_writer *nw, size_t required_size); 150 bool nlmsg_add(struct nl_writer *nw, uint32_t portid, uint32_t seq, 151 uint16_t type, uint16_t flags, uint32_t len); 152 bool nlmsg_end(struct nl_writer *nw); 153 void nlmsg_abort(struct nl_writer *nw); 154 155 bool nlmsg_end_dump(struct nl_writer *nw, int error, struct nlmsghdr *hdr); 156 157 #endif /* defined(NETLINK) || defined(NETLINK_MODULE) */ 158 159 static inline bool 160 nlmsg_reply(struct nl_writer *nw, const struct nlmsghdr *hdr, int payload_len) 161 { 162 return (nlmsg_add(nw, hdr->nlmsg_pid, hdr->nlmsg_seq, hdr->nlmsg_type, 163 hdr->nlmsg_flags, payload_len)); 164 } 165 166 /* 167 * KPI similar to mtodo(): 168 * current (uncompleted) header is guaranteed to be contiguous, 169 * but can be reallocated, thus pointers may need to be readjusted. 170 */ 171 u_int nlattr_save_offset(const struct nl_writer *nw); 172 173 static inline void * 174 _nlattr_restore_offset(const struct nl_writer *nw, int off) 175 { 176 return ((void *)((char *)nw->hdr + off)); 177 } 178 #define nlattr_restore_offset(_ns, _off, _t) ((_t *)_nlattr_restore_offset(_ns, _off)) 179 180 static inline void 181 nlattr_set_len(const struct nl_writer *nw, int off) 182 { 183 struct nlattr *nla = nlattr_restore_offset(nw, off, struct nlattr); 184 nla->nla_len = nlattr_save_offset(nw) - off; 185 } 186 187 void *nlmsg_reserve_data_raw(struct nl_writer *nw, size_t sz); 188 #define nlmsg_reserve_object(_ns, _t) ((_t *)nlmsg_reserve_data_raw(_ns, sizeof(_t))) 189 #define nlmsg_reserve_data(_ns, _sz, _t) ((_t *)nlmsg_reserve_data_raw(_ns, _sz)) 190 191 static inline int 192 nlattr_add_nested(struct nl_writer *nw, uint16_t nla_type) 193 { 194 int off = nlattr_save_offset(nw); 195 struct nlattr *nla = nlmsg_reserve_data(nw, sizeof(struct nlattr), struct nlattr); 196 if (__predict_false(nla == NULL)) 197 return (0); 198 nla->nla_type = nla_type; 199 return (off); 200 } 201 202 static inline void * 203 _nlmsg_reserve_attr(struct nl_writer *nw, uint16_t nla_type, uint16_t sz) 204 { 205 sz += sizeof(struct nlattr); 206 207 struct nlattr *nla = nlmsg_reserve_data(nw, sz, struct nlattr); 208 if (__predict_false(nla == NULL)) 209 return (NULL); 210 nla->nla_type = nla_type; 211 nla->nla_len = sz; 212 213 return ((void *)(nla + 1)); 214 } 215 #define nlmsg_reserve_attr(_ns, _at, _t) ((_t *)_nlmsg_reserve_attr(_ns, _at, NLA_ALIGN(sizeof(_t)))) 216 217 bool nlattr_add(struct nl_writer *nw, uint16_t attr_type, uint16_t attr_len, 218 const void *data); 219 220 static inline bool 221 nlattr_add_raw(struct nl_writer *nw, const struct nlattr *nla_src) 222 { 223 MPASS(nla_src->nla_len >= sizeof(struct nlattr)); 224 225 return (nlattr_add(nw, nla_src->nla_type, 226 nla_src->nla_len - sizeof(struct nlattr), 227 (const void *)(nla_src + 1))); 228 } 229 230 static inline bool 231 nlattr_add_bool(struct nl_writer *nw, uint16_t attrtype, bool value) 232 { 233 return (nlattr_add(nw, attrtype, sizeof(bool), &value)); 234 } 235 236 static inline bool 237 nlattr_add_u8(struct nl_writer *nw, uint16_t attrtype, uint8_t value) 238 { 239 return (nlattr_add(nw, attrtype, sizeof(uint8_t), &value)); 240 } 241 242 static inline bool 243 nlattr_add_u16(struct nl_writer *nw, uint16_t attrtype, uint16_t value) 244 { 245 return (nlattr_add(nw, attrtype, sizeof(uint16_t), &value)); 246 } 247 248 static inline bool 249 nlattr_add_u32(struct nl_writer *nw, uint16_t attrtype, uint32_t value) 250 { 251 return (nlattr_add(nw, attrtype, sizeof(uint32_t), &value)); 252 } 253 254 static inline bool 255 nlattr_add_u64(struct nl_writer *nw, uint16_t attrtype, uint64_t value) 256 { 257 return (nlattr_add(nw, attrtype, sizeof(uint64_t), &value)); 258 } 259 260 static inline bool 261 nlattr_add_s8(struct nl_writer *nw, uint16_t attrtype, int8_t value) 262 { 263 return (nlattr_add(nw, attrtype, sizeof(int8_t), &value)); 264 } 265 266 static inline bool 267 nlattr_add_s16(struct nl_writer *nw, uint16_t attrtype, int16_t value) 268 { 269 return (nlattr_add(nw, attrtype, sizeof(int16_t), &value)); 270 } 271 272 static inline bool 273 nlattr_add_s32(struct nl_writer *nw, uint16_t attrtype, int32_t value) 274 { 275 return (nlattr_add(nw, attrtype, sizeof(int32_t), &value)); 276 } 277 278 static inline bool 279 nlattr_add_s64(struct nl_writer *nw, uint16_t attrtype, int64_t value) 280 { 281 return (nlattr_add(nw, attrtype, sizeof(int64_t), &value)); 282 } 283 284 static inline bool 285 nlattr_add_flag(struct nl_writer *nw, uint16_t attrtype) 286 { 287 return (nlattr_add(nw, attrtype, 0, NULL)); 288 } 289 290 static inline bool 291 nlattr_add_string(struct nl_writer *nw, uint16_t attrtype, const char *str) 292 { 293 return (nlattr_add(nw, attrtype, strlen(str) + 1, str)); 294 } 295 296 static inline bool 297 nlattr_add_in_addr(struct nl_writer *nw, uint16_t attrtype, 298 const struct in_addr *in) 299 { 300 return (nlattr_add(nw, attrtype, sizeof(*in), in)); 301 } 302 303 static inline bool 304 nlattr_add_in6_addr(struct nl_writer *nw, uint16_t attrtype, 305 const struct in6_addr *in6) 306 { 307 return (nlattr_add(nw, attrtype, sizeof(*in6), in6)); 308 } 309 #endif 310 #endif 311