1 /* 2 * Copyright (C) 2011-2014 Universita` di Pisa. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 /* 28 * $FreeBSD$ 29 * 30 * Functions and macros to manipulate netmap structures and packets 31 * in userspace. See netmap(4) for more information. 32 * 33 * The address of the struct netmap_if, say nifp, is computed from the 34 * value returned from ioctl(.., NIOCREG, ...) and the mmap region: 35 * ioctl(fd, NIOCREG, &req); 36 * mem = mmap(0, ... ); 37 * nifp = NETMAP_IF(mem, req.nr_nifp); 38 * (so simple, we could just do it manually) 39 * 40 * From there: 41 * struct netmap_ring *NETMAP_TXRING(nifp, index) 42 * struct netmap_ring *NETMAP_RXRING(nifp, index) 43 * we can access ring->nr_cur, ring->nr_avail, ring->nr_flags 44 * 45 * ring->slot[i] gives us the i-th slot (we can access 46 * directly len, flags, buf_idx) 47 * 48 * char *buf = NETMAP_BUF(ring, x) returns a pointer to 49 * the buffer numbered x 50 * 51 * All ring indexes (head, cur, tail) should always move forward. 52 * To compute the next index in a circular ring you can use 53 * i = nm_ring_next(ring, i); 54 * 55 * To ease porting apps from pcap to netmap we supply a few fuctions 56 * that can be called to open, close, read and write on netmap in a way 57 * similar to libpcap. Note that the read/write function depend on 58 * an ioctl()/select()/poll() being issued to refill rings or push 59 * packets out. 60 * 61 * In order to use these, include #define NETMAP_WITH_LIBS 62 * in the source file that invokes these functions. 63 */ 64 65 #ifndef _NET_NETMAP_USER_H_ 66 #define _NET_NETMAP_USER_H_ 67 68 #include <stdint.h> 69 #include <sys/socket.h> /* apple needs sockaddr */ 70 #include <net/if.h> /* IFNAMSIZ */ 71 72 #ifndef likely 73 #define likely(x) __builtin_expect(!!(x), 1) 74 #define unlikely(x) __builtin_expect(!!(x), 0) 75 #endif /* likely and unlikely */ 76 77 #include <net/netmap.h> 78 79 /* helper macro */ 80 #define _NETMAP_OFFSET(type, ptr, offset) \ 81 ((type)(void *)((char *)(ptr) + (offset))) 82 83 #define NETMAP_IF(_base, _ofs) _NETMAP_OFFSET(struct netmap_if *, _base, _ofs) 84 85 #define NETMAP_TXRING(nifp, index) _NETMAP_OFFSET(struct netmap_ring *, \ 86 nifp, (nifp)->ring_ofs[index] ) 87 88 #define NETMAP_RXRING(nifp, index) _NETMAP_OFFSET(struct netmap_ring *, \ 89 nifp, (nifp)->ring_ofs[index + (nifp)->ni_tx_rings + 1] ) 90 91 #define NETMAP_BUF(ring, index) \ 92 ((char *)(ring) + (ring)->buf_ofs + ((index)*(ring)->nr_buf_size)) 93 94 #define NETMAP_BUF_IDX(ring, buf) \ 95 ( ((char *)(buf) - ((char *)(ring) + (ring)->buf_ofs) ) / \ 96 (ring)->nr_buf_size ) 97 98 99 static inline uint32_t 100 nm_ring_next(struct netmap_ring *r, uint32_t i) 101 { 102 return ( unlikely(i + 1 == r->num_slots) ? 0 : i + 1); 103 } 104 105 106 /* 107 * Return 1 if we have pending transmissions in the tx ring. 108 * When everything is complete ring->head = ring->tail + 1 (modulo ring size) 109 */ 110 static inline int 111 nm_tx_pending(struct netmap_ring *r) 112 { 113 return nm_ring_next(r, r->tail) != r->head; 114 } 115 116 117 static inline uint32_t 118 nm_ring_space(struct netmap_ring *ring) 119 { 120 int ret = ring->tail - ring->cur; 121 if (ret < 0) 122 ret += ring->num_slots; 123 return ret; 124 } 125 126 127 #ifdef NETMAP_WITH_LIBS 128 /* 129 * Support for simple I/O libraries. 130 * Include other system headers required for compiling this. 131 */ 132 133 #ifndef HAVE_NETMAP_WITH_LIBS 134 #define HAVE_NETMAP_WITH_LIBS 135 136 #include <sys/time.h> 137 #include <sys/mman.h> 138 #include <string.h> /* memset */ 139 #include <sys/ioctl.h> 140 #include <sys/errno.h> /* EINVAL */ 141 #include <fcntl.h> /* O_RDWR */ 142 #include <unistd.h> /* close() */ 143 #include <signal.h> 144 #include <stdlib.h> 145 146 #ifndef ND /* debug macros */ 147 /* debug support */ 148 #define ND(_fmt, ...) do {} while(0) 149 #define D(_fmt, ...) \ 150 do { \ 151 struct timeval t0; \ 152 gettimeofday(&t0, NULL); \ 153 fprintf(stderr, "%03d.%06d %s [%d] " _fmt "\n", \ 154 (int)(t0.tv_sec % 1000), (int)t0.tv_usec, \ 155 __FUNCTION__, __LINE__, ##__VA_ARGS__); \ 156 } while (0) 157 158 /* Rate limited version of "D", lps indicates how many per second */ 159 #define RD(lps, format, ...) \ 160 do { \ 161 static int t0, __cnt; \ 162 struct timeval __xxts; \ 163 gettimeofday(&__xxts, NULL); \ 164 if (t0 != __xxts.tv_sec) { \ 165 t0 = __xxts.tv_sec; \ 166 __cnt = 0; \ 167 } \ 168 if (__cnt++ < lps) { \ 169 D(format, ##__VA_ARGS__); \ 170 } \ 171 } while (0) 172 #endif 173 174 struct nm_pkthdr { /* same as pcap_pkthdr */ 175 struct timeval ts; 176 uint32_t caplen; 177 uint32_t len; 178 }; 179 180 struct nm_stat { /* same as pcap_stat */ 181 u_int ps_recv; 182 u_int ps_drop; 183 u_int ps_ifdrop; 184 #ifdef WIN32 185 u_int bs_capt; 186 #endif /* WIN32 */ 187 }; 188 189 #define NM_ERRBUF_SIZE 512 190 191 struct nm_desc { 192 struct nm_desc *self; /* point to self if netmap. */ 193 int fd; 194 void *mem; 195 int memsize; 196 int done_mmap; /* set if mem is the result of mmap */ 197 struct netmap_if * const nifp; 198 uint16_t first_tx_ring, last_tx_ring, cur_tx_ring; 199 uint16_t first_rx_ring, last_rx_ring, cur_rx_ring; 200 struct nmreq req; /* also contains the nr_name = ifname */ 201 struct nm_pkthdr hdr; 202 203 /* 204 * The memory contains netmap_if, rings and then buffers. 205 * Given a pointer (e.g. to nm_inject) we can compare with 206 * mem/buf_start/buf_end to tell if it is a buffer or 207 * some other descriptor in our region. 208 * We also store a pointer to some ring as it helps in the 209 * translation from buffer indexes to addresses. 210 */ 211 struct netmap_ring * const some_ring; 212 void * const buf_start; 213 void * const buf_end; 214 /* parameters from pcap_open_live */ 215 int snaplen; 216 int promisc; 217 int to_ms; 218 char *errbuf; 219 220 /* save flags so we can restore them on close */ 221 uint32_t if_flags; 222 uint32_t if_reqcap; 223 uint32_t if_curcap; 224 225 struct nm_stat st; 226 char msg[NM_ERRBUF_SIZE]; 227 }; 228 229 /* 230 * when the descriptor is open correctly, d->self == d 231 * Eventually we should also use some magic number. 232 */ 233 #define P2NMD(p) ((struct nm_desc *)(p)) 234 #define IS_NETMAP_DESC(d) ((d) && P2NMD(d)->self == P2NMD(d)) 235 #define NETMAP_FD(d) (P2NMD(d)->fd) 236 237 238 /* 239 * this is a slightly optimized copy routine which rounds 240 * to multiple of 64 bytes and is often faster than dealing 241 * with other odd sizes. We assume there is enough room 242 * in the source and destination buffers. 243 * 244 * XXX only for multiples of 64 bytes, non overlapped. 245 */ 246 static inline void 247 nm_pkt_copy(const void *_src, void *_dst, int l) 248 { 249 const uint64_t *src = (const uint64_t *)_src; 250 uint64_t *dst = (uint64_t *)_dst; 251 252 if (unlikely(l >= 1024)) { 253 memcpy(dst, src, l); 254 return; 255 } 256 for (; likely(l > 0); l-=64) { 257 *dst++ = *src++; 258 *dst++ = *src++; 259 *dst++ = *src++; 260 *dst++ = *src++; 261 *dst++ = *src++; 262 *dst++ = *src++; 263 *dst++ = *src++; 264 *dst++ = *src++; 265 } 266 } 267 268 269 /* 270 * The callback, invoked on each received packet. Same as libpcap 271 */ 272 typedef void (*nm_cb_t)(u_char *, const struct nm_pkthdr *, const u_char *d); 273 274 /* 275 *--- the pcap-like API --- 276 * 277 * nm_open() opens a file descriptor, binds to a port and maps memory. 278 * 279 * ifname (netmap:foo or vale:foo) is the port name 280 * a suffix can indicate the follwing: 281 * ^ bind the host (sw) ring pair 282 * * bind host and NIC ring pairs (transparent) 283 * -NN bind individual NIC ring pair 284 * {NN bind master side of pipe NN 285 * }NN bind slave side of pipe NN 286 * 287 * req provides the initial values of nmreq before parsing ifname. 288 * Remember that the ifname parsing will override the ring 289 * number in nm_ringid, and part of nm_flags; 290 * flags special functions, normally 0 291 * indicates which fields of *arg are significant 292 * arg special functions, normally NULL 293 * if passed a netmap_desc with mem != NULL, 294 * use that memory instead of mmap. 295 */ 296 297 static struct nm_desc *nm_open(const char *ifname, const struct nmreq *req, 298 uint64_t flags, const struct nm_desc *arg); 299 300 /* 301 * nm_open can import some fields from the parent descriptor. 302 * These flags control which ones. 303 * Also in flags you can specify NETMAP_NO_TX_POLL and NETMAP_DO_RX_POLL, 304 * which set the initial value for these flags. 305 * Note that the 16 low bits of the flags are reserved for data 306 * that may go into the nmreq. 307 */ 308 enum { 309 NM_OPEN_NO_MMAP = 0x040000, /* reuse mmap from parent */ 310 NM_OPEN_IFNAME = 0x080000, /* nr_name, nr_ringid, nr_flags */ 311 NM_OPEN_ARG1 = 0x100000, 312 NM_OPEN_ARG2 = 0x200000, 313 NM_OPEN_ARG3 = 0x400000, 314 NM_OPEN_RING_CFG = 0x800000, /* tx|rx rings|slots */ 315 }; 316 317 318 /* 319 * nm_close() closes and restores the port to its previous state 320 */ 321 322 static int nm_close(struct nm_desc *); 323 324 /* 325 * nm_inject() is the same as pcap_inject() 326 * nm_dispatch() is the same as pcap_dispatch() 327 * nm_nextpkt() is the same as pcap_next() 328 */ 329 330 static int nm_inject(struct nm_desc *, const void *, size_t); 331 static int nm_dispatch(struct nm_desc *, int, nm_cb_t, u_char *); 332 static u_char *nm_nextpkt(struct nm_desc *, struct nm_pkthdr *); 333 334 335 /* 336 * Try to open, return descriptor if successful, NULL otherwise. 337 * An invalid netmap name will return errno = 0; 338 * You can pass a pointer to a pre-filled nm_desc to add special 339 * parameters. Flags is used as follows 340 * NM_OPEN_NO_MMAP use the memory from arg, only 341 * if the nr_arg2 (memory block) matches. 342 * NM_OPEN_ARG1 use req.nr_arg1 from arg 343 * NM_OPEN_ARG2 use req.nr_arg2 from arg 344 * NM_OPEN_RING_CFG user ring config from arg 345 */ 346 static struct nm_desc * 347 nm_open(const char *ifname, const struct nmreq *req, 348 uint64_t new_flags, const struct nm_desc *arg) 349 { 350 struct nm_desc *d = NULL; 351 const struct nm_desc *parent = arg; 352 u_int namelen; 353 uint32_t nr_ringid = 0, nr_flags; 354 const char *port = NULL; 355 const char *errmsg = NULL; 356 357 if (strncmp(ifname, "netmap:", 7) && strncmp(ifname, "vale", 4)) { 358 errno = 0; /* name not recognised, not an error */ 359 return NULL; 360 } 361 if (ifname[0] == 'n') 362 ifname += 7; 363 /* scan for a separator */ 364 for (port = ifname; *port && !index("-*^{}", *port); port++) 365 ; 366 namelen = port - ifname; 367 if (namelen >= sizeof(d->req.nr_name)) { 368 errmsg = "name too long"; 369 goto fail; 370 } 371 switch (*port) { 372 default: /* '\0', no suffix */ 373 nr_flags = NR_REG_ALL_NIC; 374 break; 375 case '-': /* one NIC */ 376 nr_flags = NR_REG_ONE_NIC; 377 nr_ringid = atoi(port + 1); 378 break; 379 case '*': /* NIC and SW, ignore port */ 380 nr_flags = NR_REG_NIC_SW; 381 if (port[1]) { 382 errmsg = "invalid port for nic+sw"; 383 goto fail; 384 } 385 break; 386 case '^': /* only sw ring */ 387 nr_flags = NR_REG_SW; 388 if (port[1]) { 389 errmsg = "invalid port for sw ring"; 390 goto fail; 391 } 392 break; 393 case '{': 394 nr_flags = NR_REG_PIPE_MASTER; 395 nr_ringid = atoi(port + 1); 396 break; 397 case '}': 398 nr_flags = NR_REG_PIPE_SLAVE; 399 nr_ringid = atoi(port + 1); 400 break; 401 } 402 403 if (nr_ringid >= NETMAP_RING_MASK) { 404 errmsg = "invalid ringid"; 405 goto fail; 406 } 407 /* add the *XPOLL flags */ 408 nr_ringid |= new_flags & (NETMAP_NO_TX_POLL | NETMAP_DO_RX_POLL); 409 410 d = (struct nm_desc *)calloc(1, sizeof(*d)); 411 if (d == NULL) { 412 errmsg = "nm_desc alloc failure"; 413 errno = ENOMEM; 414 return NULL; 415 } 416 d->self = d; /* set this early so nm_close() works */ 417 d->fd = open("/dev/netmap", O_RDWR); 418 if (d->fd < 0) { 419 errmsg = "cannot open /dev/netmap"; 420 goto fail; 421 } 422 423 if (req) 424 d->req = *req; 425 d->req.nr_version = NETMAP_API; 426 d->req.nr_ringid &= ~NETMAP_RING_MASK; 427 428 /* these fields are overridden by ifname and flags processing */ 429 d->req.nr_ringid |= nr_ringid; 430 d->req.nr_flags = nr_flags; 431 memcpy(d->req.nr_name, ifname, namelen); 432 d->req.nr_name[namelen] = '\0'; 433 /* optionally import info from parent */ 434 if (IS_NETMAP_DESC(parent) && new_flags) { 435 if (new_flags & NM_OPEN_ARG1) 436 D("overriding ARG1 %d", parent->req.nr_arg1); 437 d->req.nr_arg1 = new_flags & NM_OPEN_ARG1 ? 438 parent->req.nr_arg1 : 4; 439 if (new_flags & NM_OPEN_ARG2) 440 D("overriding ARG2 %d", parent->req.nr_arg2); 441 d->req.nr_arg2 = new_flags & NM_OPEN_ARG2 ? 442 parent->req.nr_arg2 : 0; 443 if (new_flags & NM_OPEN_ARG3) 444 D("overriding ARG3 %d", parent->req.nr_arg3); 445 d->req.nr_arg3 = new_flags & NM_OPEN_ARG3 ? 446 parent->req.nr_arg3 : 0; 447 if (new_flags & NM_OPEN_RING_CFG) { 448 D("overriding RING_CFG"); 449 d->req.nr_tx_slots = parent->req.nr_tx_slots; 450 d->req.nr_rx_slots = parent->req.nr_rx_slots; 451 d->req.nr_tx_rings = parent->req.nr_tx_rings; 452 d->req.nr_rx_rings = parent->req.nr_rx_rings; 453 } 454 if (new_flags & NM_OPEN_IFNAME) { 455 D("overriding ifname %s ringid 0x%x flags 0x%x", 456 parent->req.nr_name, parent->req.nr_ringid, 457 parent->req.nr_flags); 458 memcpy(d->req.nr_name, parent->req.nr_name, 459 sizeof(d->req.nr_name)); 460 d->req.nr_ringid = parent->req.nr_ringid; 461 d->req.nr_flags = parent->req.nr_flags; 462 } 463 } 464 if (ioctl(d->fd, NIOCREGIF, &d->req)) { 465 errmsg = "NIOCREGIF failed"; 466 goto fail; 467 } 468 469 if (IS_NETMAP_DESC(parent) && parent->mem && 470 parent->req.nr_arg2 == d->req.nr_arg2) { 471 /* do not mmap, inherit from parent */ 472 d->memsize = parent->memsize; 473 d->mem = parent->mem; 474 } else { 475 d->memsize = d->req.nr_memsize; 476 d->mem = mmap(0, d->memsize, PROT_WRITE | PROT_READ, MAP_SHARED, 477 d->fd, 0); 478 if (d->mem == NULL) { 479 errmsg = "mmap failed"; 480 goto fail; 481 } 482 d->done_mmap = 1; 483 } 484 { 485 struct netmap_if *nifp = NETMAP_IF(d->mem, d->req.nr_offset); 486 struct netmap_ring *r = NETMAP_RXRING(nifp, ); 487 488 *(struct netmap_if **)(uintptr_t)&(d->nifp) = nifp; 489 *(struct netmap_ring **)(uintptr_t)&d->some_ring = r; 490 *(void **)(uintptr_t)&d->buf_start = NETMAP_BUF(r, 0); 491 *(void **)(uintptr_t)&d->buf_end = 492 (char *)d->mem + d->memsize; 493 } 494 495 if (nr_flags == NR_REG_SW) { /* host stack */ 496 d->first_tx_ring = d->last_tx_ring = d->req.nr_tx_rings; 497 d->first_rx_ring = d->last_rx_ring = d->req.nr_rx_rings; 498 } else if (nr_flags == NR_REG_ALL_NIC) { /* only nic */ 499 d->first_tx_ring = 0; 500 d->first_rx_ring = 0; 501 d->last_tx_ring = d->req.nr_tx_rings - 1; 502 d->last_rx_ring = d->req.nr_rx_rings - 1; 503 } else if (nr_flags == NR_REG_NIC_SW) { 504 d->first_tx_ring = 0; 505 d->first_rx_ring = 0; 506 d->last_tx_ring = d->req.nr_tx_rings; 507 d->last_rx_ring = d->req.nr_rx_rings; 508 } else if (nr_flags == NR_REG_ONE_NIC) { 509 /* XXX check validity */ 510 d->first_tx_ring = d->last_tx_ring = 511 d->first_rx_ring = d->last_rx_ring = nr_ringid; 512 } else { /* pipes */ 513 d->first_tx_ring = d->last_tx_ring = 0; 514 d->first_rx_ring = d->last_rx_ring = 0; 515 } 516 517 #ifdef DEBUG_NETMAP_USER 518 { /* debugging code */ 519 int i; 520 521 D("%s tx %d .. %d %d rx %d .. %d %d", ifname, 522 d->first_tx_ring, d->last_tx_ring, d->req.nr_tx_rings, 523 d->first_rx_ring, d->last_rx_ring, d->req.nr_rx_rings); 524 for (i = 0; i <= d->req.nr_tx_rings; i++) { 525 struct netmap_ring *r = NETMAP_TXRING(d->nifp, i); 526 D("TX%d %p h %d c %d t %d", i, r, r->head, r->cur, r->tail); 527 } 528 for (i = 0; i <= d->req.nr_rx_rings; i++) { 529 struct netmap_ring *r = NETMAP_RXRING(d->nifp, i); 530 D("RX%d %p h %d c %d t %d", i, r, r->head, r->cur, r->tail); 531 } 532 } 533 #endif /* debugging */ 534 535 d->cur_tx_ring = d->first_tx_ring; 536 d->cur_rx_ring = d->first_rx_ring; 537 return d; 538 539 fail: 540 nm_close(d); 541 if (errmsg) 542 D("%s %s", errmsg, ifname); 543 errno = EINVAL; 544 return NULL; 545 } 546 547 548 static int 549 nm_close(struct nm_desc *d) 550 { 551 /* 552 * ugly trick to avoid unused warnings 553 */ 554 static void *__xxzt[] __attribute__ ((unused)) = 555 { (void *)nm_open, (void *)nm_inject, 556 (void *)nm_dispatch, (void *)nm_nextpkt } ; 557 558 if (d == NULL || d->self != d) 559 return EINVAL; 560 if (d->done_mmap && d->mem) 561 munmap(d->mem, d->memsize); 562 if (d->fd != -1) 563 close(d->fd); 564 bzero(d, sizeof(*d)); 565 free(d); 566 return 0; 567 } 568 569 570 /* 571 * Same prototype as pcap_inject(), only need to cast. 572 */ 573 static int 574 nm_inject(struct nm_desc *d, const void *buf, size_t size) 575 { 576 u_int c, n = d->last_tx_ring - d->first_tx_ring + 1; 577 578 for (c = 0; c < n ; c++) { 579 /* compute current ring to use */ 580 struct netmap_ring *ring; 581 uint32_t i, idx; 582 uint32_t ri = d->cur_tx_ring + c; 583 584 if (ri > d->last_tx_ring) 585 ri = d->first_tx_ring; 586 ring = NETMAP_TXRING(d->nifp, ri); 587 if (nm_ring_empty(ring)) { 588 continue; 589 } 590 i = ring->cur; 591 idx = ring->slot[i].buf_idx; 592 ring->slot[i].len = size; 593 nm_pkt_copy(buf, NETMAP_BUF(ring, idx), size); 594 d->cur_tx_ring = ri; 595 ring->head = ring->cur = nm_ring_next(ring, i); 596 return size; 597 } 598 return 0; /* fail */ 599 } 600 601 602 /* 603 * Same prototype as pcap_dispatch(), only need to cast. 604 */ 605 static int 606 nm_dispatch(struct nm_desc *d, int cnt, nm_cb_t cb, u_char *arg) 607 { 608 int n = d->last_rx_ring - d->first_rx_ring + 1; 609 int c, got = 0, ri = d->cur_rx_ring; 610 611 if (cnt == 0) 612 cnt = -1; 613 /* cnt == -1 means infinite, but rings have a finite amount 614 * of buffers and the int is large enough that we never wrap, 615 * so we can omit checking for -1 616 */ 617 for (c=0; c < n && cnt != got; c++) { 618 /* compute current ring to use */ 619 struct netmap_ring *ring; 620 621 ri = d->cur_rx_ring + c; 622 if (ri > d->last_rx_ring) 623 ri = d->first_rx_ring; 624 ring = NETMAP_RXRING(d->nifp, ri); 625 for ( ; !nm_ring_empty(ring) && cnt != got; got++) { 626 u_int i = ring->cur; 627 u_int idx = ring->slot[i].buf_idx; 628 u_char *buf = (u_char *)NETMAP_BUF(ring, idx); 629 630 // __builtin_prefetch(buf); 631 d->hdr.len = d->hdr.caplen = ring->slot[i].len; 632 d->hdr.ts = ring->ts; 633 cb(arg, &d->hdr, buf); 634 ring->head = ring->cur = nm_ring_next(ring, i); 635 } 636 } 637 d->cur_rx_ring = ri; 638 return got; 639 } 640 641 static u_char * 642 nm_nextpkt(struct nm_desc *d, struct nm_pkthdr *hdr) 643 { 644 int ri = d->cur_rx_ring; 645 646 do { 647 /* compute current ring to use */ 648 struct netmap_ring *ring = NETMAP_RXRING(d->nifp, ri); 649 if (!nm_ring_empty(ring)) { 650 u_int i = ring->cur; 651 u_int idx = ring->slot[i].buf_idx; 652 u_char *buf = (u_char *)NETMAP_BUF(ring, idx); 653 654 // __builtin_prefetch(buf); 655 hdr->ts = ring->ts; 656 hdr->len = hdr->caplen = ring->slot[i].len; 657 ring->cur = nm_ring_next(ring, i); 658 /* we could postpone advancing head if we want 659 * to hold the buffer. This can be supported in 660 * the future. 661 */ 662 ring->head = ring->cur; 663 d->cur_rx_ring = ri; 664 return buf; 665 } 666 ri++; 667 if (ri > d->last_rx_ring) 668 ri = d->first_rx_ring; 669 } while (ri != d->cur_rx_ring); 670 return NULL; /* nothing found */ 671 } 672 673 #endif /* !HAVE_NETMAP_WITH_LIBS */ 674 675 #endif /* NETMAP_WITH_LIBS */ 676 677 #endif /* _NET_NETMAP_USER_H_ */ 678