1 /* 2 * Copyright (C) 2011-2014 Matteo Landi, Luigi Rizzo. 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 ``S 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 * Definitions of constants and the structures used by the netmap 31 * framework, for the part visible to both kernel and userspace. 32 * Detailed info on netmap is available with "man netmap" or at 33 * 34 * http://info.iet.unipi.it/~luigi/netmap/ 35 * 36 * This API is also used to communicate with the VALE software switch 37 */ 38 39 #ifndef _NET_NETMAP_H_ 40 #define _NET_NETMAP_H_ 41 42 #define NETMAP_API 11 /* current API version */ 43 44 #define NETMAP_MIN_API 11 /* min and max versions accepted */ 45 #define NETMAP_MAX_API 15 46 /* 47 * Some fields should be cache-aligned to reduce contention. 48 * The alignment is architecture and OS dependent, but rather than 49 * digging into OS headers to find the exact value we use an estimate 50 * that should cover most architectures. 51 */ 52 #define NM_CACHE_ALIGN 128 53 54 /* 55 * --- Netmap data structures --- 56 * 57 * The userspace data structures used by netmap are shown below. 58 * They are allocated by the kernel and mmap()ed by userspace threads. 59 * Pointers are implemented as memory offsets or indexes, 60 * so that they can be easily dereferenced in kernel and userspace. 61 62 KERNEL (opaque, obviously) 63 64 ==================================================================== 65 | 66 USERSPACE | struct netmap_ring 67 +---->+---------------+ 68 / | head,cur,tail | 69 struct netmap_if (nifp, 1 per fd) / | buf_ofs | 70 +---------------+ / | other fields | 71 | ni_tx_rings | / +===============+ 72 | ni_rx_rings | / | buf_idx, len | slot[0] 73 | | / | flags, ptr | 74 | | / +---------------+ 75 +===============+ / | buf_idx, len | slot[1] 76 | txring_ofs[0] | (rel.to nifp)--' | flags, ptr | 77 | txring_ofs[1] | +---------------+ 78 (tx+1 entries) (num_slots entries) 79 | txring_ofs[t] | | buf_idx, len | slot[n-1] 80 +---------------+ | flags, ptr | 81 | rxring_ofs[0] | +---------------+ 82 | rxring_ofs[1] | 83 (rx+1 entries) 84 | rxring_ofs[r] | 85 +---------------+ 86 87 * For each "interface" (NIC, host stack, PIPE, VALE switch port) bound to 88 * a file descriptor, the mmap()ed region contains a (logically readonly) 89 * struct netmap_if pointing to struct netmap_ring's. 90 * 91 * There is one netmap_ring per physical NIC ring, plus one tx/rx ring 92 * pair attached to the host stack (this pair is unused for non-NIC ports). 93 * 94 * All physical/host stack ports share the same memory region, 95 * so that zero-copy can be implemented between them. 96 * VALE switch ports instead have separate memory regions. 97 * 98 * The netmap_ring is the userspace-visible replica of the NIC ring. 99 * Each slot has the index of a buffer (MTU-sized and residing in the 100 * mmapped region), its length and some flags. An extra 64-bit pointer 101 * is provided for user-supplied buffers in the tx path. 102 * 103 * In user space, the buffer address is computed as 104 * (char *)ring + buf_ofs + index * NETMAP_BUF_SIZE 105 * 106 * Added in NETMAP_API 11: 107 * 108 * + NIOCREGIF can request the allocation of extra spare buffers from 109 * the same memory pool. The desired number of buffers must be in 110 * nr_arg3. The ioctl may return fewer buffers, depending on memory 111 * availability. nr_arg3 will return the actual value, and, once 112 * mapped, nifp->ni_bufs_head will be the index of the first buffer. 113 * 114 * The buffers are linked to each other using the first uint32_t 115 * as the index. On close, ni_bufs_head must point to the list of 116 * buffers to be released. 117 * 118 * + NIOCREGIF can request space for extra rings (and buffers) 119 * allocated in the same memory space. The number of extra rings 120 * is in nr_arg1, and is advisory. This is a no-op on NICs where 121 * the size of the memory space is fixed. 122 * 123 * + NIOCREGIF can attach to PIPE rings sharing the same memory 124 * space with a parent device. The ifname indicates the parent device, 125 * which must already exist. Flags in nr_flags indicate if we want to 126 * bind the master or slave side, the index (from nr_ringid) 127 * is just a cookie and does not need to be sequential. 128 * 129 * + NIOCREGIF can also attach to 'monitor' rings that replicate 130 * the content of specific rings, also from the same memory space. 131 * 132 * Extra flags in nr_flags support the above functions. 133 * Application libraries may use the following naming scheme: 134 * netmap:foo all NIC ring pairs 135 * netmap:foo^ only host ring pair 136 * netmap:foo+ all NIC ring + host ring pairs 137 * netmap:foo-k the k-th NIC ring pair 138 * netmap:foo{k PIPE ring pair k, master side 139 * netmap:foo}k PIPE ring pair k, slave side 140 */ 141 142 /* 143 * struct netmap_slot is a buffer descriptor 144 */ 145 struct netmap_slot { 146 uint32_t buf_idx; /* buffer index */ 147 uint16_t len; /* length for this slot */ 148 uint16_t flags; /* buf changed, etc. */ 149 uint64_t ptr; /* pointer for indirect buffers */ 150 }; 151 152 /* 153 * The following flags control how the slot is used 154 */ 155 156 #define NS_BUF_CHANGED 0x0001 /* buf_idx changed */ 157 /* 158 * must be set whenever buf_idx is changed (as it might be 159 * necessary to recompute the physical address and mapping) 160 * 161 * It is also set by the kernel whenever the buf_idx is 162 * changed internally (e.g., by pipes). Applications may 163 * use this information to know when they can reuse the 164 * contents of previously prepared buffers. 165 */ 166 167 #define NS_REPORT 0x0002 /* ask the hardware to report results */ 168 /* 169 * Request notification when slot is used by the hardware. 170 * Normally transmit completions are handled lazily and 171 * may be unreported. This flag lets us know when a slot 172 * has been sent (e.g. to terminate the sender). 173 */ 174 175 #define NS_FORWARD 0x0004 /* pass packet 'forward' */ 176 /* 177 * (Only for physical ports, rx rings with NR_FORWARD set). 178 * Slot released to the kernel (i.e. before ring->head) with 179 * this flag set are passed to the peer ring (host/NIC), 180 * thus restoring the host-NIC connection for these slots. 181 * This supports efficient traffic monitoring or firewalling. 182 */ 183 184 #define NS_NO_LEARN 0x0008 /* disable bridge learning */ 185 /* 186 * On a VALE switch, do not 'learn' the source port for 187 * this buffer. 188 */ 189 190 #define NS_INDIRECT 0x0010 /* userspace buffer */ 191 /* 192 * (VALE tx rings only) data is in a userspace buffer, 193 * whose address is in the 'ptr' field in the slot. 194 */ 195 196 #define NS_MOREFRAG 0x0020 /* packet has more fragments */ 197 /* 198 * (VALE ports only) 199 * Set on all but the last slot of a multi-segment packet. 200 * The 'len' field refers to the individual fragment. 201 */ 202 203 #define NS_PORT_SHIFT 8 204 #define NS_PORT_MASK (0xff << NS_PORT_SHIFT) 205 /* 206 * The high 8 bits of the flag, if not zero, indicate the 207 * destination port for the VALE switch, overriding 208 * the lookup table. 209 */ 210 211 #define NS_RFRAGS(_slot) ( ((_slot)->flags >> 8) & 0xff) 212 /* 213 * (VALE rx rings only) the high 8 bits 214 * are the number of fragments. 215 */ 216 217 218 /* 219 * struct netmap_ring 220 * 221 * Netmap representation of a TX or RX ring (also known as "queue"). 222 * This is a queue implemented as a fixed-size circular array. 223 * At the software level the important fields are: head, cur, tail. 224 * 225 * In TX rings: 226 * 227 * head first slot available for transmission. 228 * cur wakeup point. select() and poll() will unblock 229 * when 'tail' moves past 'cur' 230 * tail (readonly) first slot reserved to the kernel 231 * 232 * [head .. tail-1] can be used for new packets to send; 233 * 'head' and 'cur' must be incremented as slots are filled 234 * with new packets to be sent; 235 * 'cur' can be moved further ahead if we need more space 236 * for new transmissions. XXX todo (2014-03-12) 237 * 238 * In RX rings: 239 * 240 * head first valid received packet 241 * cur wakeup point. select() and poll() will unblock 242 * when 'tail' moves past 'cur' 243 * tail (readonly) first slot reserved to the kernel 244 * 245 * [head .. tail-1] contain received packets; 246 * 'head' and 'cur' must be incremented as slots are consumed 247 * and can be returned to the kernel; 248 * 'cur' can be moved further ahead if we want to wait for 249 * new packets without returning the previous ones. 250 * 251 * DATA OWNERSHIP/LOCKING: 252 * The netmap_ring, and all slots and buffers in the range 253 * [head .. tail-1] are owned by the user program; 254 * the kernel only accesses them during a netmap system call 255 * and in the user thread context. 256 * 257 * Other slots and buffers are reserved for use by the kernel 258 */ 259 struct netmap_ring { 260 /* 261 * buf_ofs is meant to be used through macros. 262 * It contains the offset of the buffer region from this 263 * descriptor. 264 */ 265 const int64_t buf_ofs; 266 const uint32_t num_slots; /* number of slots in the ring. */ 267 const uint32_t nr_buf_size; 268 const uint16_t ringid; 269 const uint16_t dir; /* 0: tx, 1: rx */ 270 271 uint32_t head; /* (u) first user slot */ 272 uint32_t cur; /* (u) wakeup point */ 273 uint32_t tail; /* (k) first kernel slot */ 274 275 uint32_t flags; 276 277 struct timeval ts; /* (k) time of last *sync() */ 278 279 /* opaque room for a mutex or similar object */ 280 uint8_t sem[128] __attribute__((__aligned__(NM_CACHE_ALIGN))); 281 282 /* the slots follow. This struct has variable size */ 283 struct netmap_slot slot[0]; /* array of slots. */ 284 }; 285 286 287 /* 288 * RING FLAGS 289 */ 290 #define NR_TIMESTAMP 0x0002 /* set timestamp on *sync() */ 291 /* 292 * updates the 'ts' field on each netmap syscall. This saves 293 * saves a separate gettimeofday(), and is not much worse than 294 * software timestamps generated in the interrupt handler. 295 */ 296 297 #define NR_FORWARD 0x0004 /* enable NS_FORWARD for ring */ 298 /* 299 * Enables the NS_FORWARD slot flag for the ring. 300 */ 301 302 303 /* 304 * Netmap representation of an interface and its queue(s). 305 * This is initialized by the kernel when binding a file 306 * descriptor to a port, and should be considered as readonly 307 * by user programs. The kernel never uses it. 308 * 309 * There is one netmap_if for each file descriptor on which we want 310 * to select/poll. 311 * select/poll operates on one or all pairs depending on the value of 312 * nmr_queueid passed on the ioctl. 313 */ 314 struct netmap_if { 315 char ni_name[IFNAMSIZ]; /* name of the interface. */ 316 const uint32_t ni_version; /* API version, currently unused */ 317 const uint32_t ni_flags; /* properties */ 318 #define NI_PRIV_MEM 0x1 /* private memory region */ 319 320 /* 321 * The number of packet rings available in netmap mode. 322 * Physical NICs can have different numbers of tx and rx rings. 323 * Physical NICs also have a 'host' ring pair. 324 * Additionally, clients can request additional ring pairs to 325 * be used for internal communication. 326 */ 327 const uint32_t ni_tx_rings; /* number of HW tx rings */ 328 const uint32_t ni_rx_rings; /* number of HW rx rings */ 329 330 uint32_t ni_bufs_head; /* head index for extra bufs */ 331 uint32_t ni_spare1[5]; 332 /* 333 * The following array contains the offset of each netmap ring 334 * from this structure, in the following order: 335 * NIC tx rings (ni_tx_rings); host tx ring (1); extra tx rings; 336 * NIC rx rings (ni_rx_rings); host tx ring (1); extra rx rings. 337 * 338 * The area is filled up by the kernel on NIOCREGIF, 339 * and then only read by userspace code. 340 */ 341 const ssize_t ring_ofs[0]; 342 }; 343 344 345 #ifndef NIOCREGIF 346 /* 347 * ioctl names and related fields 348 * 349 * NIOCTXSYNC, NIOCRXSYNC synchronize tx or rx queues, 350 * whose identity is set in NIOCREGIF through nr_ringid. 351 * These are non blocking and take no argument. 352 * 353 * NIOCGINFO takes a struct ifreq, the interface name is the input, 354 * the outputs are number of queues and number of descriptor 355 * for each queue (useful to set number of threads etc.). 356 * The info returned is only advisory and may change before 357 * the interface is bound to a file descriptor. 358 * 359 * NIOCREGIF takes an interface name within a struct nmre, 360 * and activates netmap mode on the interface (if possible). 361 * 362 * The argument to NIOCGINFO/NIOCREGIF overlays struct ifreq so we 363 * can pass it down to other NIC-related ioctls. 364 * 365 * The actual argument (struct nmreq) has a number of options to request 366 * different functions. 367 * The following are used in NIOCREGIF when nr_cmd == 0: 368 * 369 * nr_name (in) 370 * The name of the port (em0, valeXXX:YYY, etc.) 371 * limited to IFNAMSIZ for backward compatibility. 372 * 373 * nr_version (in/out) 374 * Must match NETMAP_API as used in the kernel, error otherwise. 375 * Always returns the desired value on output. 376 * 377 * nr_tx_slots, nr_tx_slots, nr_tx_rings, nr_rx_rings (in/out) 378 * On input, non-zero values may be used to reconfigure the port 379 * according to the requested values, but this is not guaranteed. 380 * On output the actual values in use are reported. 381 * 382 * nr_ringid (in) 383 * Indicates how rings should be bound to the file descriptors. 384 * If nr_flags != 0, then the low bits (in NETMAP_RING_MASK) 385 * are used to indicate the ring number, and nr_flags specifies 386 * the actual rings to bind. NETMAP_NO_TX_POLL is unaffected. 387 * 388 * NOTE: THE FOLLOWING (nr_flags == 0) IS DEPRECATED: 389 * If nr_flags == 0, NETMAP_HW_RING and NETMAP_SW_RING control 390 * the binding as follows: 391 * 0 (default) binds all physical rings 392 * NETMAP_HW_RING | ring number binds a single ring pair 393 * NETMAP_SW_RING binds only the host tx/rx rings 394 * 395 * NETMAP_NO_TX_POLL can be OR-ed to make select()/poll() push 396 * packets on tx rings only if POLLOUT is set. 397 * The default is to push any pending packet. 398 * 399 * NETMAP_DO_RX_POLL can be OR-ed to make select()/poll() release 400 * packets on rx rings also when POLLIN is NOT set. 401 * The default is to touch the rx ring only with POLLIN. 402 * Note that this is the opposite of TX because it 403 * reflects the common usage. 404 * 405 * NOTE: NETMAP_PRIV_MEM IS DEPRECATED, use nr_arg2 instead. 406 * NETMAP_PRIV_MEM is set on return for ports that do not use 407 * the global memory allocator. 408 * This information is not significant and applications 409 * should look at the region id in nr_arg2 410 * 411 * nr_flags is the recommended mode to indicate which rings should 412 * be bound to a file descriptor. Values are NR_REG_* 413 * 414 * nr_arg1 (in) The number of extra rings to be reserved. 415 * Especially when allocating a VALE port the system only 416 * allocates the amount of memory needed for the port. 417 * If more shared memory rings are desired (e.g. for pipes), 418 * the first invocation for the same basename/allocator 419 * should specify a suitable number. Memory cannot be 420 * extended after the first allocation without closing 421 * all ports on the same region. 422 * 423 * nr_arg2 (in/out) The identity of the memory region used. 424 * On input, 0 means the system decides autonomously, 425 * other values may try to select a specific region. 426 * On return the actual value is reported. 427 * Region '1' is the global allocator, normally shared 428 * by all interfaces. Other values are private regions. 429 * If two ports the same region zero-copy is possible. 430 * 431 * nr_arg3 (in/out) number of extra buffers to be allocated. 432 * 433 * 434 * 435 * nr_cmd (in) if non-zero indicates a special command: 436 * NETMAP_BDG_ATTACH and nr_name = vale*:ifname 437 * attaches the NIC to the switch; nr_ringid specifies 438 * which rings to use. Used by vale-ctl -a ... 439 * nr_arg1 = NETMAP_BDG_HOST also attaches the host port 440 * as in vale-ctl -h ... 441 * 442 * NETMAP_BDG_DETACH and nr_name = vale*:ifname 443 * disconnects a previously attached NIC. 444 * Used by vale-ctl -d ... 445 * 446 * NETMAP_BDG_LIST 447 * list the configuration of VALE switches. 448 * 449 * NETMAP_BDG_VNET_HDR 450 * Set the virtio-net header length used by the client 451 * of a VALE switch port. 452 * 453 * NETMAP_BDG_NEWIF 454 * create a persistent VALE port with name nr_name. 455 * Used by vale-ctl -n ... 456 * 457 * NETMAP_BDG_DELIF 458 * delete a persistent VALE port. Used by vale-ctl -d ... 459 * 460 * nr_arg1, nr_arg2, nr_arg3 (in/out) command specific 461 * 462 * 463 * 464 */ 465 466 467 /* 468 * struct nmreq overlays a struct ifreq (just the name) 469 */ 470 struct nmreq { 471 char nr_name[IFNAMSIZ]; 472 uint32_t nr_version; /* API version */ 473 uint32_t nr_offset; /* nifp offset in the shared region */ 474 uint32_t nr_memsize; /* size of the shared region */ 475 uint32_t nr_tx_slots; /* slots in tx rings */ 476 uint32_t nr_rx_slots; /* slots in rx rings */ 477 uint16_t nr_tx_rings; /* number of tx rings */ 478 uint16_t nr_rx_rings; /* number of rx rings */ 479 480 uint16_t nr_ringid; /* ring(s) we care about */ 481 #define NETMAP_HW_RING 0x4000 /* single NIC ring pair */ 482 #define NETMAP_SW_RING 0x2000 /* only host ring pair */ 483 484 #define NETMAP_RING_MASK 0x0fff /* the ring number */ 485 486 #define NETMAP_NO_TX_POLL 0x1000 /* no automatic txsync on poll */ 487 488 #define NETMAP_DO_RX_POLL 0x8000 /* DO automatic rxsync on poll */ 489 490 uint16_t nr_cmd; 491 #define NETMAP_BDG_ATTACH 1 /* attach the NIC */ 492 #define NETMAP_BDG_DETACH 2 /* detach the NIC */ 493 #define NETMAP_BDG_REGOPS 3 /* register bridge callbacks */ 494 #define NETMAP_BDG_LIST 4 /* get bridge's info */ 495 #define NETMAP_BDG_VNET_HDR 5 /* set the port virtio-net-hdr length */ 496 #define NETMAP_BDG_OFFSET NETMAP_BDG_VNET_HDR /* deprecated alias */ 497 #define NETMAP_BDG_NEWIF 6 /* create a virtual port */ 498 #define NETMAP_BDG_DELIF 7 /* destroy a virtual port */ 499 uint16_t nr_arg1; /* reserve extra rings in NIOCREGIF */ 500 #define NETMAP_BDG_HOST 1 /* attach the host stack on ATTACH */ 501 502 uint16_t nr_arg2; 503 uint32_t nr_arg3; /* req. extra buffers in NIOCREGIF */ 504 uint32_t nr_flags; 505 /* various modes, extends nr_ringid */ 506 uint32_t spare2[1]; 507 }; 508 509 #define NR_REG_MASK 0xf /* values for nr_flags */ 510 enum { NR_REG_DEFAULT = 0, /* backward compat, should not be used. */ 511 NR_REG_ALL_NIC = 1, 512 NR_REG_SW = 2, 513 NR_REG_NIC_SW = 3, 514 NR_REG_ONE_NIC = 4, 515 NR_REG_PIPE_MASTER = 5, 516 NR_REG_PIPE_SLAVE = 6, 517 }; 518 /* monitor uses the NR_REG to select the rings to monitor */ 519 #define NR_MONITOR_TX 0x100 520 #define NR_MONITOR_RX 0x200 521 #define NR_ZCOPY_MON 0x400 522 /* request exclusive access to the selected rings */ 523 #define NR_EXCLUSIVE 0x800 524 525 526 /* 527 * FreeBSD uses the size value embedded in the _IOWR to determine 528 * how much to copy in/out. So we need it to match the actual 529 * data structure we pass. We put some spares in the structure 530 * to ease compatibility with other versions 531 */ 532 #define NIOCGINFO _IOWR('i', 145, struct nmreq) /* return IF info */ 533 #define NIOCREGIF _IOWR('i', 146, struct nmreq) /* interface register */ 534 #define NIOCTXSYNC _IO('i', 148) /* sync tx queues */ 535 #define NIOCRXSYNC _IO('i', 149) /* sync rx queues */ 536 #define NIOCCONFIG _IOWR('i',150, struct nm_ifreq) /* for ext. modules */ 537 #endif /* !NIOCREGIF */ 538 539 540 /* 541 * Helper functions for kernel and userspace 542 */ 543 544 /* 545 * check if space is available in the ring. 546 */ 547 static inline int 548 nm_ring_empty(struct netmap_ring *ring) 549 { 550 return (ring->cur == ring->tail); 551 } 552 553 /* 554 * Opaque structure that is passed to an external kernel 555 * module via ioctl(fd, NIOCCONFIG, req) for a user-owned 556 * bridge port (at this point ephemeral VALE interface). 557 */ 558 #define NM_IFRDATA_LEN 256 559 struct nm_ifreq { 560 char nifr_name[IFNAMSIZ]; 561 char data[NM_IFRDATA_LEN]; 562 }; 563 564 #endif /* _NET_NETMAP_H_ */ 565