1 /* $NetBSD: bpf.h,v 1.65 2014/06/24 22:19:36 rmind Exp $ */ 2 3 /* 4 * Copyright (c) 1990, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from the Stanford/CMU enet packet filter, 8 * (net/enet.c) distributed as part of 4.3BSD, and code contributed 9 * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence 10 * Berkeley Laboratory. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)bpf.h 8.2 (Berkeley) 1/9/95 37 * @(#) Header: bpf.h,v 1.36 97/06/12 14:29:53 leres Exp (LBL) 38 */ 39 40 #ifndef _NET_BPF_H_ 41 #define _NET_BPF_H_ 42 43 #include <sys/time.h> 44 45 /* BSD style release date */ 46 #define BPF_RELEASE 199606 47 48 /* Date when COP instructions and external memory have been released. */ 49 #define BPF_COP_EXTMEM_RELEASE 20140624 50 51 __BEGIN_DECLS 52 53 typedef int bpf_int32; 54 typedef u_int bpf_u_int32; 55 56 /* 57 * Alignment macros. BPF_WORDALIGN rounds up to the next 58 * even multiple of BPF_ALIGNMENT. 59 */ 60 #define BPF_ALIGNMENT sizeof(long) 61 #define BPF_ALIGNMENT32 sizeof(int) 62 63 #define BPF_WORDALIGN(x) (((x)+(BPF_ALIGNMENT-1))&~(BPF_ALIGNMENT-1)) 64 #define BPF_WORDALIGN32(x) (((x)+(BPF_ALIGNMENT32-1))&~(BPF_ALIGNMENT32-1)) 65 66 #define BPF_MAXINSNS 512 67 #define BPF_DFLTBUFSIZE (1024*1024) /* default static upper limit */ 68 #define BPF_MAXBUFSIZE (1024*1024*16) /* hard limit on sysctl'able value */ 69 #define BPF_MINBUFSIZE 32 70 71 /* 72 * Structure for BIOCSETF. 73 */ 74 struct bpf_program { 75 u_int bf_len; 76 struct bpf_insn *bf_insns; 77 }; 78 79 /* 80 * Struct returned by BIOCGSTATS and net.bpf.stats sysctl. 81 */ 82 struct bpf_stat { 83 uint64_t bs_recv; /* number of packets received */ 84 uint64_t bs_drop; /* number of packets dropped */ 85 uint64_t bs_capt; /* number of packets captured */ 86 uint64_t bs_padding[13]; 87 }; 88 89 /* 90 * Struct returned by BIOCGSTATSOLD. 91 */ 92 struct bpf_stat_old { 93 u_int bs_recv; /* number of packets received */ 94 u_int bs_drop; /* number of packets dropped */ 95 }; 96 97 /* 98 * Struct return by BIOCVERSION. This represents the version number of 99 * the filter language described by the instruction encodings below. 100 * bpf understands a program iff kernel_major == filter_major && 101 * kernel_minor >= filter_minor, that is, if the value returned by the 102 * running kernel has the same major number and a minor number equal 103 * equal to or less than the filter being downloaded. Otherwise, the 104 * results are undefined, meaning an error may be returned or packets 105 * may be accepted haphazardly. 106 * It has nothing to do with the source code version. 107 */ 108 struct bpf_version { 109 u_short bv_major; 110 u_short bv_minor; 111 }; 112 /* Current version number of filter architecture. */ 113 #define BPF_MAJOR_VERSION 1 114 #define BPF_MINOR_VERSION 1 115 116 /* 117 * BPF ioctls 118 * 119 * The first set is for compatibility with Sun's pcc style 120 * header files. If your using gcc, we assume that you 121 * have run fixincludes so the latter set should work. 122 */ 123 #define BIOCGBLEN _IOR('B',102, u_int) 124 #define BIOCSBLEN _IOWR('B',102, u_int) 125 #define BIOCSETF _IOW('B',103, struct bpf_program) 126 #define BIOCFLUSH _IO('B',104) 127 #define BIOCPROMISC _IO('B',105) 128 #define BIOCGDLT _IOR('B',106, u_int) 129 #define BIOCGETIF _IOR('B',107, struct ifreq) 130 #define BIOCSETIF _IOW('B',108, struct ifreq) 131 #ifdef COMPAT_50 132 #include <compat/sys/time.h> 133 #define BIOCSORTIMEOUT _IOW('B',109, struct timeval50) 134 #define BIOCGORTIMEOUT _IOR('B',110, struct timeval50) 135 #endif 136 #define BIOCGSTATS _IOR('B',111, struct bpf_stat) 137 #define BIOCGSTATSOLD _IOR('B',111, struct bpf_stat_old) 138 #define BIOCIMMEDIATE _IOW('B',112, u_int) 139 #define BIOCVERSION _IOR('B',113, struct bpf_version) 140 #define BIOCSTCPF _IOW('B',114, struct bpf_program) 141 #define BIOCSUDPF _IOW('B',115, struct bpf_program) 142 #define BIOCGHDRCMPLT _IOR('B',116, u_int) 143 #define BIOCSHDRCMPLT _IOW('B',117, u_int) 144 #define BIOCSDLT _IOW('B',118, u_int) 145 #define BIOCGDLTLIST _IOWR('B',119, struct bpf_dltlist) 146 #define BIOCGSEESENT _IOR('B',120, u_int) 147 #define BIOCSSEESENT _IOW('B',121, u_int) 148 #define BIOCSRTIMEOUT _IOW('B',122, struct timeval) 149 #define BIOCGRTIMEOUT _IOR('B',123, struct timeval) 150 #define BIOCGFEEDBACK _IOR('B',124, u_int) 151 #define BIOCSFEEDBACK _IOW('B',125, u_int) 152 #define BIOCFEEDBACK BIOCSFEEDBACK /* FreeBSD name */ 153 154 /* 155 * Structure prepended to each packet. This is "wire" format, so we 156 * cannot change it unfortunately to 64 bit times on 32 bit systems [yet]. 157 */ 158 struct bpf_timeval { 159 long tv_sec; 160 long tv_usec; 161 }; 162 163 struct bpf_timeval32 { 164 int32_t tv_sec; 165 int32_t tv_usec; 166 }; 167 168 struct bpf_hdr { 169 struct bpf_timeval bh_tstamp; /* time stamp */ 170 uint32_t bh_caplen; /* length of captured portion */ 171 uint32_t bh_datalen; /* original length of packet */ 172 uint16_t bh_hdrlen; /* length of bpf header (this struct 173 plus alignment padding) */ 174 }; 175 176 struct bpf_hdr32 { 177 struct bpf_timeval32 bh_tstamp; /* time stamp */ 178 uint32_t bh_caplen; /* length of captured portion */ 179 uint32_t bh_datalen; /* original length of packet */ 180 uint16_t bh_hdrlen; /* length of bpf header (this struct 181 plus alignment padding) */ 182 }; 183 /* 184 * Because the structure above is not a multiple of 4 bytes, some compilers 185 * will insist on inserting padding; hence, sizeof(struct bpf_hdr) won't work. 186 * Only the kernel needs to know about it; applications use bh_hdrlen. 187 * XXX To save a few bytes on 32-bit machines, we avoid end-of-struct 188 * XXX padding by using the size of the header data elements. This is 189 * XXX fail-safe: on new machines, we just use the 'safe' sizeof. 190 */ 191 #ifdef _KERNEL 192 #if defined(__arm32__) || defined(__i386__) || defined(__m68k__) || \ 193 defined(__mips__) || defined(__ns32k__) || defined(__vax__) || \ 194 defined(__sh__) || (defined(__sparc__) && !defined(__sparc64__)) 195 #define SIZEOF_BPF_HDR 18 196 #define SIZEOF_BPF_HDR32 18 197 #else 198 #define SIZEOF_BPF_HDR sizeof(struct bpf_hdr) 199 #define SIZEOF_BPF_HDR32 sizeof(struct bpf_hdr32) 200 #endif 201 #endif 202 203 /* Pull in data-link level type codes. */ 204 #include <net/dlt.h> 205 206 /* 207 * The instruction encodings. 208 */ 209 /* instruction classes */ 210 #define BPF_CLASS(code) ((code) & 0x07) 211 #define BPF_LD 0x00 212 #define BPF_LDX 0x01 213 #define BPF_ST 0x02 214 #define BPF_STX 0x03 215 #define BPF_ALU 0x04 216 #define BPF_JMP 0x05 217 #define BPF_RET 0x06 218 #define BPF_MISC 0x07 219 220 /* ld/ldx fields */ 221 #define BPF_SIZE(code) ((code) & 0x18) 222 #define BPF_W 0x00 223 #define BPF_H 0x08 224 #define BPF_B 0x10 225 #define BPF_MODE(code) ((code) & 0xe0) 226 #define BPF_IMM 0x00 227 #define BPF_ABS 0x20 228 #define BPF_IND 0x40 229 #define BPF_MEM 0x60 230 #define BPF_LEN 0x80 231 #define BPF_MSH 0xa0 232 233 /* alu/jmp fields */ 234 #define BPF_OP(code) ((code) & 0xf0) 235 #define BPF_ADD 0x00 236 #define BPF_SUB 0x10 237 #define BPF_MUL 0x20 238 #define BPF_DIV 0x30 239 #define BPF_OR 0x40 240 #define BPF_AND 0x50 241 #define BPF_LSH 0x60 242 #define BPF_RSH 0x70 243 #define BPF_NEG 0x80 244 #define BPF_JA 0x00 245 #define BPF_JEQ 0x10 246 #define BPF_JGT 0x20 247 #define BPF_JGE 0x30 248 #define BPF_JSET 0x40 249 #define BPF_SRC(code) ((code) & 0x08) 250 #define BPF_K 0x00 251 #define BPF_X 0x08 252 253 /* ret - BPF_K and BPF_X also apply */ 254 #define BPF_RVAL(code) ((code) & 0x18) 255 #define BPF_A 0x10 256 257 /* misc */ 258 #define BPF_MISCOP(code) ((code) & 0xf8) 259 #define BPF_TAX 0x00 260 #define BPF_COP 0x20 261 #define BPF_COPX 0x40 262 #define BPF_TXA 0x80 263 264 /* 265 * The instruction data structure. 266 */ 267 struct bpf_insn { 268 uint16_t code; 269 u_char jt; 270 u_char jf; 271 uint32_t k; 272 }; 273 274 /* 275 * Macros for insn array initializers. 276 */ 277 #define BPF_STMT(code, k) { (uint16_t)(code), 0, 0, k } 278 #define BPF_JUMP(code, k, jt, jf) { (uint16_t)(code), jt, jf, k } 279 280 /* 281 * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST). 282 */ 283 #define BPF_MEMWORDS 16 284 285 /* 286 * bpf_memword_init_t: bits indicate which words in the external memory 287 * store will be initialised by the caller before BPF program execution. 288 */ 289 typedef uint32_t bpf_memword_init_t; 290 #define BPF_MEMWORD_INIT(k) (UINT32_C(1) << (k)) 291 292 /* Note: two most significant bits are reserved by bpfjit. */ 293 __CTASSERT(BPF_MEMWORDS + 2 <= sizeof(bpf_memword_init_t) * NBBY); 294 295 #ifdef _KERNEL 296 /* 297 * Max number of external memory words (for BPF_LD|BPF_MEM and BPF_ST). 298 */ 299 #define BPF_MAX_MEMWORDS 30 300 301 __CTASSERT(BPF_MAX_MEMWORDS >= BPF_MEMWORDS); 302 __CTASSERT(BPF_MAX_MEMWORDS + 2 <= sizeof(bpf_memword_init_t) * NBBY); 303 #endif 304 305 /* 306 * Structure to retrieve available DLTs for the interface. 307 */ 308 struct bpf_dltlist { 309 u_int bfl_len; /* number of bfd_list array */ 310 u_int *bfl_list; /* array of DLTs */ 311 }; 312 313 struct bpf_ctx; 314 typedef struct bpf_ctx bpf_ctx_t; 315 316 typedef struct bpf_args { 317 const uint8_t * pkt; 318 size_t wirelen; 319 size_t buflen; 320 /* 321 * The following arguments are used only by some kernel 322 * subsystems. 323 * They aren't required for classical bpf filter programs. 324 * For such programs, bpfjit generated code doesn't read 325 * those arguments at all. Note however that bpf interpreter 326 * always needs a pointer to memstore. 327 */ 328 uint32_t * mem; /* pointer to external memory store */ 329 void * arg; /* auxiliary argument for a copfunc */ 330 } bpf_args_t; 331 332 #if defined(_KERNEL) || defined(__BPF_PRIVATE) 333 334 typedef uint32_t (*bpf_copfunc_t)(const bpf_ctx_t *, bpf_args_t *, uint32_t); 335 336 struct bpf_ctx { 337 /* 338 * BPF coprocessor functions and the number of them. 339 */ 340 const bpf_copfunc_t * copfuncs; 341 size_t nfuncs; 342 343 /* 344 * The number of memory words in the external memory store. 345 * There may be up to BPF_MAX_MEMWORDS words; if zero is set, 346 * then the internal memory store is used which has a fixed 347 * number of words (BPF_MEMWORDS). 348 */ 349 size_t extwords; 350 351 /* 352 * The bitmask indicating which words in the external memstore 353 * will be initialised by the caller. 354 */ 355 bpf_memword_init_t preinited; 356 }; 357 #endif 358 359 #ifdef _KERNEL 360 #include <net/bpfjit.h> 361 #include <net/if.h> 362 363 struct bpf_if; 364 365 struct bpf_ops { 366 void (*bpf_attach)(struct ifnet *, u_int, u_int, struct bpf_if **); 367 void (*bpf_detach)(struct ifnet *); 368 void (*bpf_change_type)(struct ifnet *, u_int, u_int); 369 370 void (*bpf_tap)(struct bpf_if *, u_char *, u_int); 371 void (*bpf_mtap)(struct bpf_if *, struct mbuf *); 372 void (*bpf_mtap2)(struct bpf_if *, void *, u_int, struct mbuf *); 373 void (*bpf_mtap_af)(struct bpf_if *, uint32_t, struct mbuf *); 374 void (*bpf_mtap_sl_in)(struct bpf_if *, u_char *, struct mbuf **); 375 void (*bpf_mtap_sl_out)(struct bpf_if *, u_char *, struct mbuf *); 376 }; 377 378 extern struct bpf_ops *bpf_ops; 379 380 static inline void 381 bpf_attach(struct ifnet *_ifp, u_int _dlt, u_int _hdrlen) 382 { 383 bpf_ops->bpf_attach(_ifp, _dlt, _hdrlen, &_ifp->if_bpf); 384 } 385 386 static inline void 387 bpf_attach2(struct ifnet *_ifp, u_int _dlt, u_int _hdrlen, struct bpf_if **_dp) 388 { 389 bpf_ops->bpf_attach(_ifp, _dlt, _hdrlen, _dp); 390 } 391 392 static inline void 393 bpf_tap(struct ifnet *_ifp, u_char *_pkt, u_int _len) 394 { 395 if (_ifp->if_bpf) 396 bpf_ops->bpf_tap(_ifp->if_bpf, _pkt, _len); 397 } 398 399 static inline void 400 bpf_mtap(struct ifnet *_ifp, struct mbuf *_m) 401 { 402 if (_ifp->if_bpf) 403 bpf_ops->bpf_mtap(_ifp->if_bpf, _m); 404 } 405 406 static inline void 407 bpf_mtap2(struct bpf_if *_bpf, void *_data, u_int _dlen, struct mbuf *_m) 408 { 409 bpf_ops->bpf_mtap2(_bpf, _data, _dlen, _m); 410 } 411 412 static inline void 413 bpf_mtap3(struct bpf_if *_bpf, struct mbuf *_m) 414 { 415 if (_bpf) 416 bpf_ops->bpf_mtap(_bpf, _m); 417 } 418 419 static inline void 420 bpf_mtap_af(struct ifnet *_ifp, uint32_t _af, struct mbuf *_m) 421 { 422 if (_ifp->if_bpf) 423 bpf_ops->bpf_mtap_af(_ifp->if_bpf, _af, _m); 424 } 425 426 static inline void 427 bpf_change_type(struct ifnet *_ifp, u_int _dlt, u_int _hdrlen) 428 { 429 bpf_ops->bpf_change_type(_ifp, _dlt, _hdrlen); 430 } 431 432 static inline void 433 bpf_detach(struct ifnet *_ifp) 434 { 435 bpf_ops->bpf_detach(_ifp); 436 } 437 438 static inline void 439 bpf_mtap_sl_in(struct ifnet *_ifp, u_char *_hdr, struct mbuf **_m) 440 { 441 bpf_ops->bpf_mtap_sl_in(_ifp->if_bpf, _hdr, _m); 442 } 443 444 static inline void 445 bpf_mtap_sl_out(struct ifnet *_ifp, u_char *_hdr, struct mbuf *_m) 446 { 447 if (_ifp->if_bpf) 448 bpf_ops->bpf_mtap_sl_out(_ifp->if_bpf, _hdr, _m); 449 } 450 451 452 void bpf_setops(void); 453 454 void bpf_ops_handover_enter(struct bpf_ops *); 455 void bpf_ops_handover_exit(void); 456 457 void bpfilterattach(int); 458 459 bpf_ctx_t *bpf_create(void); 460 void bpf_destroy(bpf_ctx_t *); 461 462 int bpf_set_cop(bpf_ctx_t *, const bpf_copfunc_t *, size_t); 463 int bpf_set_extmem(bpf_ctx_t *, size_t, bpf_memword_init_t); 464 u_int bpf_filter_ext(const bpf_ctx_t *, const struct bpf_insn *, bpf_args_t *); 465 int bpf_validate_ext(const bpf_ctx_t *, const struct bpf_insn *, int); 466 467 bpfjit_func_t bpf_jit_generate(bpf_ctx_t *, void *, size_t); 468 void bpf_jit_freecode(bpfjit_func_t); 469 470 #endif 471 472 int bpf_validate(const struct bpf_insn *, int); 473 u_int bpf_filter(const struct bpf_insn *, const u_char *, u_int, u_int); 474 475 __END_DECLS 476 477 #endif /* !_NET_BPF_H_ */ 478