1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 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 37 #ifndef _NET_BPF_H_ 38 #define _NET_BPF_H_ 39 40 #include <sys/_eventhandler.h> 41 #include <sys/ck.h> 42 #include <net/dlt.h> 43 44 /* BSD style release date */ 45 #define BPF_RELEASE 199606 46 47 typedef int32_t bpf_int32; 48 typedef u_int32_t bpf_u_int32; 49 typedef int64_t bpf_int64; 50 typedef u_int64_t bpf_u_int64; 51 struct ifnet; 52 53 /* 54 * Alignment macros. BPF_WORDALIGN rounds up to the next multiple of 55 * BPF_ALIGNMENT. 56 */ 57 #define BPF_ALIGNMENT sizeof(long) 58 #define BPF_WORDALIGN(x) (((x)+(BPF_ALIGNMENT-1))&~(BPF_ALIGNMENT-1)) 59 60 #define BPF_MAXINSNS 512 61 #define BPF_MAXBUFSIZE 0x80000 62 #define BPF_MINBUFSIZE 32 63 64 /* 65 * Structure for BIOCSETF. 66 */ 67 struct bpf_program { 68 u_int bf_len; 69 struct bpf_insn *bf_insns; 70 }; 71 72 /* 73 * Struct returned by BIOCGSTATS. 74 */ 75 struct bpf_stat { 76 u_int bs_recv; /* number of packets received */ 77 u_int bs_drop; /* number of packets dropped */ 78 }; 79 80 /* 81 * Struct return by BIOCVERSION. This represents the version number of 82 * the filter language described by the instruction encodings below. 83 * bpf understands a program iff kernel_major == filter_major && 84 * kernel_minor >= filter_minor, that is, if the value returned by the 85 * running kernel has the same major number and a minor number equal 86 * equal to or less than the filter being downloaded. Otherwise, the 87 * results are undefined, meaning an error may be returned or packets 88 * may be accepted haphazardly. 89 * It has nothing to do with the source code version. 90 */ 91 struct bpf_version { 92 u_short bv_major; 93 u_short bv_minor; 94 }; 95 /* Current version number of filter architecture. */ 96 #define BPF_MAJOR_VERSION 1 97 #define BPF_MINOR_VERSION 1 98 99 /* 100 * Historically, BPF has supported a single buffering model, first using mbuf 101 * clusters in kernel, and later using malloc(9) buffers in kernel. We now 102 * support multiple buffering modes, which may be queried and set using 103 * BIOCGETBUFMODE and BIOCSETBUFMODE. So as to avoid handling the complexity 104 * of changing modes while sniffing packets, the mode becomes fixed once an 105 * interface has been attached to the BPF descriptor. 106 */ 107 #define BPF_BUFMODE_BUFFER 1 /* Kernel buffers with read(). */ 108 #define BPF_BUFMODE_ZBUF 2 /* Zero-copy buffers. */ 109 110 /*- 111 * Struct used by BIOCSETZBUF, BIOCROTZBUF: describes up to two zero-copy 112 * buffer as used by BPF. 113 */ 114 struct bpf_zbuf { 115 void *bz_bufa; /* Location of 'a' zero-copy buffer. */ 116 void *bz_bufb; /* Location of 'b' zero-copy buffer. */ 117 size_t bz_buflen; /* Size of zero-copy buffers. */ 118 }; 119 120 #define BIOCGBLEN _IOR('B', 102, u_int) 121 #define BIOCSBLEN _IOWR('B', 102, u_int) 122 #define BIOCSETF _IOW('B', 103, struct bpf_program) 123 #define BIOCFLUSH _IO('B', 104) 124 #define BIOCPROMISC _IO('B', 105) 125 #define BIOCGDLT _IOR('B', 106, u_int) 126 #define BIOCGETIF _IOR('B', 107, struct ifreq) 127 #define BIOCSETIF _IOW('B', 108, struct ifreq) 128 #define BIOCSRTIMEOUT _IOW('B', 109, struct timeval) 129 #define BIOCGRTIMEOUT _IOR('B', 110, struct timeval) 130 #define BIOCGSTATS _IOR('B', 111, struct bpf_stat) 131 #define BIOCIMMEDIATE _IOW('B', 112, u_int) 132 #define BIOCVERSION _IOR('B', 113, struct bpf_version) 133 #define BIOCGRSIG _IOR('B', 114, u_int) 134 #define BIOCSRSIG _IOW('B', 115, u_int) 135 #define BIOCGHDRCMPLT _IOR('B', 116, u_int) 136 #define BIOCSHDRCMPLT _IOW('B', 117, u_int) 137 #define BIOCGDIRECTION _IOR('B', 118, u_int) 138 #define BIOCSDIRECTION _IOW('B', 119, u_int) 139 #define BIOCSDLT _IOW('B', 120, u_int) 140 #define BIOCGDLTLIST _IOWR('B', 121, struct bpf_dltlist) 141 #define BIOCLOCK _IO('B', 122) 142 #define BIOCSETWF _IOW('B', 123, struct bpf_program) 143 #define BIOCFEEDBACK _IOW('B', 124, u_int) 144 #define BIOCGETBUFMODE _IOR('B', 125, u_int) 145 #define BIOCSETBUFMODE _IOW('B', 126, u_int) 146 #define BIOCGETZMAX _IOR('B', 127, size_t) 147 #define BIOCROTZBUF _IOR('B', 128, struct bpf_zbuf) 148 #define BIOCSETZBUF _IOW('B', 129, struct bpf_zbuf) 149 #define BIOCSETFNR _IOW('B', 130, struct bpf_program) 150 #define BIOCGTSTAMP _IOR('B', 131, u_int) 151 #define BIOCSTSTAMP _IOW('B', 132, u_int) 152 #define BIOCSETVLANPCP _IOW('B', 133, u_int) 153 154 /* Obsolete */ 155 #define BIOCGSEESENT BIOCGDIRECTION 156 #define BIOCSSEESENT BIOCSDIRECTION 157 158 /* Packet directions */ 159 enum bpf_direction { 160 BPF_D_IN, /* See incoming packets */ 161 BPF_D_INOUT, /* See incoming and outgoing packets */ 162 BPF_D_OUT /* See outgoing packets */ 163 }; 164 165 /* Time stamping functions */ 166 #define BPF_T_MICROTIME 0x0000 167 #define BPF_T_NANOTIME 0x0001 168 #define BPF_T_BINTIME 0x0002 169 #define BPF_T_NONE 0x0003 170 #define BPF_T_FORMAT_MASK 0x0003 171 #define BPF_T_NORMAL 0x0000 172 #define BPF_T_FAST 0x0100 173 #define BPF_T_MONOTONIC 0x0200 174 #define BPF_T_MONOTONIC_FAST (BPF_T_FAST | BPF_T_MONOTONIC) 175 #define BPF_T_FLAG_MASK 0x0300 176 #define BPF_T_FORMAT(t) ((t) & BPF_T_FORMAT_MASK) 177 #define BPF_T_FLAG(t) ((t) & BPF_T_FLAG_MASK) 178 #define BPF_T_VALID(t) \ 179 ((t) == BPF_T_NONE || (BPF_T_FORMAT(t) != BPF_T_NONE && \ 180 ((t) & ~(BPF_T_FORMAT_MASK | BPF_T_FLAG_MASK)) == 0)) 181 182 #define BPF_T_MICROTIME_FAST (BPF_T_MICROTIME | BPF_T_FAST) 183 #define BPF_T_NANOTIME_FAST (BPF_T_NANOTIME | BPF_T_FAST) 184 #define BPF_T_BINTIME_FAST (BPF_T_BINTIME | BPF_T_FAST) 185 #define BPF_T_MICROTIME_MONOTONIC (BPF_T_MICROTIME | BPF_T_MONOTONIC) 186 #define BPF_T_NANOTIME_MONOTONIC (BPF_T_NANOTIME | BPF_T_MONOTONIC) 187 #define BPF_T_BINTIME_MONOTONIC (BPF_T_BINTIME | BPF_T_MONOTONIC) 188 #define BPF_T_MICROTIME_MONOTONIC_FAST (BPF_T_MICROTIME | BPF_T_MONOTONIC_FAST) 189 #define BPF_T_NANOTIME_MONOTONIC_FAST (BPF_T_NANOTIME | BPF_T_MONOTONIC_FAST) 190 #define BPF_T_BINTIME_MONOTONIC_FAST (BPF_T_BINTIME | BPF_T_MONOTONIC_FAST) 191 192 /* 193 * Structure prepended to each packet. 194 */ 195 struct bpf_ts { 196 bpf_int64 bt_sec; /* seconds */ 197 bpf_u_int64 bt_frac; /* fraction */ 198 }; 199 struct bpf_xhdr { 200 struct bpf_ts bh_tstamp; /* time stamp */ 201 bpf_u_int32 bh_caplen; /* length of captured portion */ 202 bpf_u_int32 bh_datalen; /* original length of packet */ 203 u_short bh_hdrlen; /* length of bpf header (this struct 204 plus alignment padding) */ 205 }; 206 /* Obsolete */ 207 struct bpf_hdr { 208 struct timeval bh_tstamp; /* time stamp */ 209 bpf_u_int32 bh_caplen; /* length of captured portion */ 210 bpf_u_int32 bh_datalen; /* original length of packet */ 211 u_short bh_hdrlen; /* length of bpf header (this struct 212 plus alignment padding) */ 213 }; 214 #ifdef _KERNEL 215 #define MTAG_BPF 0x627066 216 #define MTAG_BPF_TIMESTAMP 0 217 #endif 218 219 /* 220 * When using zero-copy BPF buffers, a shared memory header is present 221 * allowing the kernel BPF implementation and user process to synchronize 222 * without using system calls. This structure defines that header. When 223 * accessing these fields, appropriate atomic operation and memory barriers 224 * are required in order not to see stale or out-of-order data; see bpf(4) 225 * for reference code to access these fields from userspace. 226 * 227 * The layout of this structure is critical, and must not be changed; if must 228 * fit in a single page on all architectures. 229 */ 230 struct bpf_zbuf_header { 231 volatile u_int bzh_kernel_gen; /* Kernel generation number. */ 232 volatile u_int bzh_kernel_len; /* Length of data in the buffer. */ 233 volatile u_int bzh_user_gen; /* User generation number. */ 234 u_int _bzh_pad[5]; 235 }; 236 237 /* 238 * The instruction encodings. 239 * 240 * Please inform tcpdump-workers@lists.tcpdump.org if you use any 241 * of the reserved values, so that we can note that they're used 242 * (and perhaps implement it in the reference BPF implementation 243 * and encourage its implementation elsewhere). 244 */ 245 246 /* 247 * The upper 8 bits of the opcode aren't used. BSD/OS used 0x8000. 248 */ 249 250 /* instruction classes */ 251 #define BPF_CLASS(code) ((code) & 0x07) 252 #define BPF_LD 0x00 253 #define BPF_LDX 0x01 254 #define BPF_ST 0x02 255 #define BPF_STX 0x03 256 #define BPF_ALU 0x04 257 #define BPF_JMP 0x05 258 #define BPF_RET 0x06 259 #define BPF_MISC 0x07 260 261 /* ld/ldx fields */ 262 #define BPF_SIZE(code) ((code) & 0x18) 263 #define BPF_W 0x00 264 #define BPF_H 0x08 265 #define BPF_B 0x10 266 /* 0x18 reserved; used by BSD/OS */ 267 #define BPF_MODE(code) ((code) & 0xe0) 268 #define BPF_IMM 0x00 269 #define BPF_ABS 0x20 270 #define BPF_IND 0x40 271 #define BPF_MEM 0x60 272 #define BPF_LEN 0x80 273 #define BPF_MSH 0xa0 274 /* 0xc0 reserved; used by BSD/OS */ 275 /* 0xe0 reserved; used by BSD/OS */ 276 277 /* alu/jmp fields */ 278 #define BPF_OP(code) ((code) & 0xf0) 279 #define BPF_ADD 0x00 280 #define BPF_SUB 0x10 281 #define BPF_MUL 0x20 282 #define BPF_DIV 0x30 283 #define BPF_OR 0x40 284 #define BPF_AND 0x50 285 #define BPF_LSH 0x60 286 #define BPF_RSH 0x70 287 #define BPF_NEG 0x80 288 #define BPF_MOD 0x90 289 #define BPF_XOR 0xa0 290 /* 0xb0 reserved */ 291 /* 0xc0 reserved */ 292 /* 0xd0 reserved */ 293 /* 0xe0 reserved */ 294 /* 0xf0 reserved */ 295 296 #define BPF_JA 0x00 297 #define BPF_JEQ 0x10 298 #define BPF_JGT 0x20 299 #define BPF_JGE 0x30 300 #define BPF_JSET 0x40 301 /* 0x50 reserved; used on BSD/OS */ 302 /* 0x60 reserved */ 303 /* 0x70 reserved */ 304 /* 0x80 reserved */ 305 /* 0x90 reserved */ 306 /* 0xa0 reserved */ 307 /* 0xb0 reserved */ 308 /* 0xc0 reserved */ 309 /* 0xd0 reserved */ 310 /* 0xe0 reserved */ 311 /* 0xf0 reserved */ 312 #define BPF_SRC(code) ((code) & 0x08) 313 #define BPF_K 0x00 314 #define BPF_X 0x08 315 316 /* ret - BPF_K and BPF_X also apply */ 317 #define BPF_RVAL(code) ((code) & 0x18) 318 #define BPF_A 0x10 319 /* 0x18 reserved */ 320 321 /* misc */ 322 #define BPF_MISCOP(code) ((code) & 0xf8) 323 #define BPF_TAX 0x00 324 /* 0x08 reserved */ 325 /* 0x10 reserved */ 326 /* 0x18 reserved */ 327 /* #define BPF_COP 0x20 NetBSD "coprocessor" extensions */ 328 /* 0x28 reserved */ 329 /* 0x30 reserved */ 330 /* 0x38 reserved */ 331 /* #define BPF_COPX 0x40 NetBSD "coprocessor" extensions */ 332 /* also used on BSD/OS */ 333 /* 0x48 reserved */ 334 /* 0x50 reserved */ 335 /* 0x58 reserved */ 336 /* 0x60 reserved */ 337 /* 0x68 reserved */ 338 /* 0x70 reserved */ 339 /* 0x78 reserved */ 340 #define BPF_TXA 0x80 341 /* 0x88 reserved */ 342 /* 0x90 reserved */ 343 /* 0x98 reserved */ 344 /* 0xa0 reserved */ 345 /* 0xa8 reserved */ 346 /* 0xb0 reserved */ 347 /* 0xb8 reserved */ 348 /* 0xc0 reserved; used on BSD/OS */ 349 /* 0xc8 reserved */ 350 /* 0xd0 reserved */ 351 /* 0xd8 reserved */ 352 /* 0xe0 reserved */ 353 /* 0xe8 reserved */ 354 /* 0xf0 reserved */ 355 /* 0xf8 reserved */ 356 357 /* 358 * The instruction data structure. 359 */ 360 struct bpf_insn { 361 u_short code; 362 u_char jt; 363 u_char jf; 364 bpf_u_int32 k; 365 }; 366 367 /* 368 * Macros for insn array initializers. 369 */ 370 #define BPF_STMT(code, k) { (u_short)(code), 0, 0, k } 371 #define BPF_JUMP(code, k, jt, jf) { (u_short)(code), jt, jf, k } 372 373 /* 374 * Structure to retrieve available DLTs for the interface. 375 */ 376 struct bpf_dltlist { 377 u_int bfl_len; /* number of bfd_list array */ 378 u_int *bfl_list; /* array of DLTs */ 379 }; 380 381 #ifdef _KERNEL 382 #ifdef MALLOC_DECLARE 383 MALLOC_DECLARE(M_BPF); 384 #endif 385 #ifdef SYSCTL_DECL 386 SYSCTL_DECL(_net_bpf); 387 #endif 388 389 /* 390 * Rotate the packet buffers in descriptor d. Move the store buffer into the 391 * hold slot, and the free buffer into the store slot. Zero the length of the 392 * new store buffer. Descriptor lock should be held. One must be careful to 393 * not rotate the buffers twice, i.e. if fbuf != NULL. 394 */ 395 #define ROTATE_BUFFERS(d) do { \ 396 (d)->bd_hbuf = (d)->bd_sbuf; \ 397 (d)->bd_hlen = (d)->bd_slen; \ 398 (d)->bd_sbuf = (d)->bd_fbuf; \ 399 (d)->bd_slen = 0; \ 400 (d)->bd_fbuf = NULL; \ 401 bpf_bufheld(d); \ 402 } while (0) 403 404 /* 405 * Descriptor associated with each attached hardware interface. 406 * Part of this structure is exposed to external callers to speed up 407 * bpf_peers_present() calls. 408 */ 409 struct bpf_if; 410 CK_LIST_HEAD(bpfd_list, bpf_d); 411 412 struct bpf_if_ext { 413 CK_LIST_ENTRY(bpf_if) bif_next; /* list of all interfaces */ 414 struct bpfd_list bif_dlist; /* descriptor list */ 415 }; 416 417 void bpf_bufheld(struct bpf_d *d); 418 int bpf_validate(const struct bpf_insn *, int); 419 void bpf_tap(struct bpf_if *, u_char *, u_int); 420 void bpf_tap_if(struct ifnet *, u_char *, u_int); 421 void bpf_mtap(struct bpf_if *, struct mbuf *); 422 void bpf_mtap_if(struct ifnet *, struct mbuf *); 423 void bpf_mtap2(struct bpf_if *, void *, u_int, struct mbuf *); 424 void bpf_mtap2_if(struct ifnet *, void *, u_int, struct mbuf *); 425 void bpfattach(struct ifnet *, u_int, u_int); 426 void bpfattach2(struct ifnet *, u_int, u_int, struct bpf_if **); 427 void bpfdetach(struct ifnet *); 428 bool bpf_peers_present_if(struct ifnet *); 429 #ifdef VIMAGE 430 int bpf_get_bp_params(struct bpf_if *, u_int *, u_int *); 431 #endif 432 433 void bpfilterattach(int); 434 u_int bpf_filter(const struct bpf_insn *, u_char *, u_int, u_int); 435 436 static __inline bool 437 bpf_peers_present(struct bpf_if *bpf) 438 { 439 struct bpf_if_ext *ext; 440 441 ext = (struct bpf_if_ext *)bpf; 442 return (!CK_LIST_EMPTY(&ext->bif_dlist)); 443 } 444 445 #define BPF_TAP(_ifp,_pkt,_pktlen) \ 446 bpf_tap_if((_ifp), (_pkt), (_pktlen)) 447 #define BPF_MTAP(_ifp,_m) \ 448 bpf_mtap_if((_ifp), (_m)) 449 #define BPF_MTAP2(_ifp,_data,_dlen,_m) \ 450 bpf_mtap2_if((_ifp), (_data), (_dlen), (_m)) 451 #endif 452 453 /* 454 * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST). 455 */ 456 #define BPF_MEMWORDS 16 457 458 /* BPF attach/detach events */ 459 typedef void (*bpf_track_fn)(void *, struct ifnet *, int /* dlt */, 460 int /* 1 =>'s attach */); 461 EVENTHANDLER_DECLARE(bpf_track, bpf_track_fn); 462 463 #endif /* _NET_BPF_H_ */ 464