1 /* 2 * Copyright (C) 2011 Matteo Landi, Luigi Rizzo. All rights reserved. 3 * Copyright (C) 2013 Universita` di Pisa 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 /* 29 * $FreeBSD$ 30 * 31 * This header contains the macros used to manipulate netmap structures 32 * and packets in userspace. See netmap(4) for more information. 33 * 34 * The address of the struct netmap_if, say nifp, is computed from the 35 * value returned from ioctl(.., NIOCREG, ...) and the mmap region: 36 * ioctl(fd, NIOCREG, &req); 37 * mem = mmap(0, ... ); 38 * nifp = NETMAP_IF(mem, req.nr_nifp); 39 * (so simple, we could just do it manually) 40 * 41 * From there: 42 * struct netmap_ring *NETMAP_TXRING(nifp, index) 43 * struct netmap_ring *NETMAP_RXRING(nifp, index) 44 * we can access ring->nr_cur, ring->nr_avail, ring->nr_flags 45 * 46 * ring->slot[i] gives us the i-th slot (we can access 47 * directly plen, flags, bufindex) 48 * 49 * char *buf = NETMAP_BUF(ring, x) returns a pointer to 50 * the buffer numbered x 51 * 52 * Since rings are circular, we have macros to compute the next index 53 * i = NETMAP_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 and read from netmap in a way 57 * similar to libpcap. 58 * 59 * In order to use these, include #define NETMAP_WITH_LIBS 60 * in the source file that invokes these functions. 61 */ 62 63 #ifndef _NET_NETMAP_USER_H_ 64 #define _NET_NETMAP_USER_H_ 65 66 #include <stdint.h> 67 #include <net/if.h> /* IFNAMSIZ */ 68 #include <net/netmap/netmap.h> 69 70 #define _NETMAP_OFFSET(type, ptr, offset) \ 71 ((type)(void *)((char *)(ptr) + (offset))) 72 73 #define NETMAP_IF(b, o) _NETMAP_OFFSET(struct netmap_if *, b, o) 74 75 #define NETMAP_TXRING(nifp, index) _NETMAP_OFFSET(struct netmap_ring *, \ 76 nifp, (nifp)->ring_ofs[index] ) 77 78 #define NETMAP_RXRING(nifp, index) _NETMAP_OFFSET(struct netmap_ring *, \ 79 nifp, (nifp)->ring_ofs[index + (nifp)->ni_tx_rings + 1] ) 80 81 #define NETMAP_BUF(ring, index) \ 82 ((char *)(ring) + (ring)->buf_ofs + ((index)*(ring)->nr_buf_size)) 83 84 #define NETMAP_BUF_IDX(ring, buf) \ 85 ( ((char *)(buf) - ((char *)(ring) + (ring)->buf_ofs) ) / \ 86 (ring)->nr_buf_size ) 87 88 #define NETMAP_RING_NEXT(r, i) \ 89 ((i)+1 == (r)->num_slots ? 0 : (i) + 1 ) 90 91 #define NETMAP_RING_FIRST_RESERVED(r) \ 92 ( (r)->cur < (r)->reserved ? \ 93 (r)->cur + (r)->num_slots - (r)->reserved : \ 94 (r)->cur - (r)->reserved ) 95 96 /* 97 * Return 1 if the given tx ring is empty. 98 */ 99 #define NETMAP_TX_RING_EMPTY(r) ((r)->avail >= (r)->num_slots - 1) 100 101 #ifdef NETMAP_WITH_LIBS 102 /* 103 * Support for simple I/O libraries. 104 * Include other system headers required for compiling this. 105 */ 106 107 #ifndef HAVE_NETMAP_WITH_LIBS 108 #define HAVE_NETMAP_WITH_LIBS 109 110 #include <sys/time.h> 111 #include <sys/mman.h> 112 #include <string.h> /* memset */ 113 #include <sys/ioctl.h> 114 #include <sys/errno.h> /* EINVAL */ 115 #include <fcntl.h> /* O_RDWR */ 116 #include <stdlib.h> 117 118 struct nm_hdr_t { /* same as pcap_pkthdr */ 119 struct timeval ts; 120 uint32_t caplen; 121 uint32_t len; 122 }; 123 124 struct nm_desc_t { 125 struct nm_desc_t *self; 126 int fd; 127 void *mem; 128 int memsize; 129 struct netmap_if *nifp; 130 uint16_t first_ring, last_ring, cur_ring; 131 struct nmreq req; 132 struct nm_hdr_t hdr; 133 }; 134 135 /* 136 * when the descriptor is open correctly, d->self == d 137 */ 138 #define P2NMD(p) ((struct nm_desc_t *)(p)) 139 #define IS_NETMAP_DESC(d) (P2NMD(d)->self == P2NMD(d)) 140 #define NETMAP_FD(d) (P2NMD(d)->fd) 141 142 /* 143 * The callback, invoked on each received packet. Same as libpcap 144 */ 145 typedef void (*nm_cb_t)(u_char *, const struct nm_hdr_t *, const u_char *d); 146 147 /* 148 * The open routine accepts an ifname (netmap:foo or vale:foo) and 149 * optionally a second (string) argument indicating the ring number 150 * to open. If successful, t opens the fd and maps the memory. 151 */ 152 static struct nm_desc_t *nm_open(const char *ifname, 153 const char *ring_no, int flags, int ring_flags); 154 155 /* 156 * nm_dispatch() is the same as pcap_dispatch() 157 * nm_next() is the same as pcap_next() 158 */ 159 static int nm_dispatch(struct nm_desc_t *, int, nm_cb_t, u_char *); 160 static u_char *nm_next(struct nm_desc_t *, struct nm_hdr_t *); 161 162 /* 163 * unmap memory, close file descriptor and free the descriptor. 164 */ 165 static int nm_close(struct nm_desc_t *); 166 167 168 /* 169 * Try to open, return descriptor if successful, NULL otherwise. 170 * An invalid netmap name will return errno = 0; 171 */ 172 static struct nm_desc_t * 173 nm_open(const char *ifname, const char *ring_name, int flags, int ring_flags) 174 { 175 struct nm_desc_t *d; 176 u_int n; 177 178 if (strncmp(ifname, "netmap:", 7) && strncmp(ifname, "vale", 4)) { 179 errno = 0; /* name not recognised */ 180 return NULL; 181 } 182 if (ifname[0] == 'n') 183 ifname += 7; 184 d = (struct nm_desc_t *)calloc(1, sizeof(*d)); 185 if (d == NULL) { 186 errno = ENOMEM; 187 return NULL; 188 } 189 d->self = d; /* set this early so nm_close() works */ 190 d->fd = open("/dev/netmap", O_RDWR); 191 if (d->fd < 0) 192 goto fail; 193 194 if (flags & NETMAP_SW_RING) { 195 d->req.nr_ringid = NETMAP_SW_RING; 196 } else { 197 u_int r; 198 if (flags & NETMAP_HW_RING) /* interpret ring as int */ 199 r = (uintptr_t)ring_name; 200 else /* interpret ring as numeric string */ 201 r = ring_name ? atoi(ring_name) : ~0; 202 r = (r < NETMAP_RING_MASK) ? (r | NETMAP_HW_RING) : 0; 203 d->req.nr_ringid = r; /* set the ring */ 204 } 205 d->req.nr_ringid |= (flags & ~NETMAP_RING_MASK); 206 d->req.nr_version = NETMAP_API; 207 strncpy(d->req.nr_name, ifname, sizeof(d->req.nr_name)); 208 if (ioctl(d->fd, NIOCREGIF, &d->req)) 209 goto fail; 210 211 d->memsize = d->req.nr_memsize; 212 d->mem = mmap(0, d->memsize, PROT_WRITE | PROT_READ, MAP_SHARED, 213 d->fd, 0); 214 if (d->mem == NULL) 215 goto fail; 216 d->nifp = NETMAP_IF(d->mem, d->req.nr_offset); 217 if (d->req.nr_ringid & NETMAP_SW_RING) { 218 d->first_ring = d->last_ring = d->req.nr_rx_rings; 219 } else if (d->req.nr_ringid & NETMAP_HW_RING) { 220 d->first_ring = d->last_ring = 221 d->req.nr_ringid & NETMAP_RING_MASK; 222 } else { 223 d->first_ring = 0; 224 d->last_ring = d->req.nr_rx_rings - 1; 225 } 226 d->cur_ring = d->first_ring; 227 for (n = d->first_ring; n <= d->last_ring; n++) { 228 struct netmap_ring *ring = NETMAP_RXRING(d->nifp, n); 229 ring->flags |= ring_flags; 230 } 231 return d; 232 233 fail: 234 nm_close(d); 235 errno = EINVAL; 236 return NULL; 237 } 238 239 240 static int 241 nm_close(struct nm_desc_t *d) 242 { 243 if (d == NULL || d->self != d) 244 return EINVAL; 245 if (d->mem) 246 munmap(d->mem, d->memsize); 247 if (d->fd) 248 close(d->fd); 249 bzero(d, sizeof(*d)); 250 free(d); 251 return 0; 252 } 253 254 255 /* 256 * Same prototype as pcap_dispatch(), only need to cast. 257 */ 258 inline /* not really, but disable unused warnings */ 259 static int 260 nm_dispatch(struct nm_desc_t *d, int cnt, nm_cb_t cb, u_char *arg) 261 { 262 int n = d->last_ring - d->first_ring + 1; 263 int c, got = 0, ri = d->cur_ring; 264 265 if (cnt == 0) 266 cnt = -1; 267 /* cnt == -1 means infinite, but rings have a finite amount 268 * of buffers and the int is large enough that we never wrap, 269 * so we can omit checking for -1 270 */ 271 for (c=0; c < n && cnt != got; c++) { 272 /* compute current ring to use */ 273 struct netmap_ring *ring; 274 275 ri = d->cur_ring + c; 276 if (ri > d->last_ring) 277 ri = d->first_ring; 278 ring = NETMAP_RXRING(d->nifp, ri); 279 for ( ; ring->avail > 0 && cnt != got; got++) { 280 u_int i = ring->cur; 281 u_int idx = ring->slot[i].buf_idx; 282 u_char *buf = (u_char *)NETMAP_BUF(ring, idx); 283 // XXX should check valid buf 284 // prefetch(buf); 285 d->hdr.len = d->hdr.caplen = ring->slot[i].len; 286 d->hdr.ts = ring->ts; 287 cb(arg, &d->hdr, buf); 288 ring->cur = NETMAP_RING_NEXT(ring, i); 289 ring->avail--; 290 } 291 } 292 d->cur_ring = ri; 293 return got; 294 } 295 296 inline /* not really, but disable unused warnings */ 297 static u_char * 298 nm_next(struct nm_desc_t *d, struct nm_hdr_t *hdr) 299 { 300 int ri = d->cur_ring; 301 302 do { 303 /* compute current ring to use */ 304 struct netmap_ring *ring = NETMAP_RXRING(d->nifp, ri); 305 if (ring->avail > 0) { 306 u_int i = ring->cur; 307 u_int idx = ring->slot[i].buf_idx; 308 u_char *buf = (u_char *)NETMAP_BUF(ring, idx); 309 // XXX should check valid buf 310 // prefetch(buf); 311 hdr->ts = ring->ts; 312 hdr->len = hdr->caplen = ring->slot[i].len; 313 ring->cur = NETMAP_RING_NEXT(ring, i); 314 ring->avail--; 315 d->cur_ring = ri; 316 return buf; 317 } 318 ri++; 319 if (ri > d->last_ring) 320 ri = d->first_ring; 321 } while (ri != d->cur_ring); 322 return NULL; /* nothing found */ 323 } 324 325 #endif /* !HAVE_NETMAP_WITH_LIBS */ 326 327 #endif /* NETMAP_WITH_LIBS */ 328 329 #endif /* _NET_NETMAP_USER_H_ */ 330