2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (C) 2011-2014 Matteo Landi, Luigi Rizzo. All rights reserved.
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7 * modification, are permitted provided that the following conditions
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32 * Definitions of constants and the structures used by the netmap
33 * framework, for the part visible to both kernel and userspace.
34 * Detailed info on netmap is available with "man netmap" or at
36 * http://info.iet.unipi.it/~luigi/netmap/
38 * This API is also used to communicate with the VALE software switch
41 #ifndef _NET_NETMAP_H_
42 #define _NET_NETMAP_H_
44 #define NETMAP_API 11 /* current API version */
46 #define NETMAP_MIN_API 11 /* min and max versions accepted */
47 #define NETMAP_MAX_API 15
49 * Some fields should be cache-aligned to reduce contention.
50 * The alignment is architecture and OS dependent, but rather than
51 * digging into OS headers to find the exact value we use an estimate
52 * that should cover most architectures.
54 #define NM_CACHE_ALIGN 128
57 * --- Netmap data structures ---
59 * The userspace data structures used by netmap are shown below.
60 * They are allocated by the kernel and mmap()ed by userspace threads.
61 * Pointers are implemented as memory offsets or indexes,
62 * so that they can be easily dereferenced in kernel and userspace.
64 KERNEL (opaque, obviously)
66 ====================================================================
68 USERSPACE | struct netmap_ring
69 +---->+---------------+
71 struct netmap_if (nifp, 1 per fd) / | buf_ofs |
72 +---------------+ / | other fields |
73 | ni_tx_rings | / +===============+
74 | ni_rx_rings | / | buf_idx, len | slot[0]
76 | | / +---------------+
77 +===============+ / | buf_idx, len | slot[1]
78 | txring_ofs[0] | (rel.to nifp)--' | flags, ptr |
79 | txring_ofs[1] | +---------------+
80 (tx+1 entries) (num_slots entries)
81 | txring_ofs[t] | | buf_idx, len | slot[n-1]
82 +---------------+ | flags, ptr |
83 | rxring_ofs[0] | +---------------+
89 * For each "interface" (NIC, host stack, PIPE, VALE switch port) bound to
90 * a file descriptor, the mmap()ed region contains a (logically readonly)
91 * struct netmap_if pointing to struct netmap_ring's.
93 * There is one netmap_ring per physical NIC ring, plus one tx/rx ring
94 * pair attached to the host stack (this pair is unused for non-NIC ports).
96 * All physical/host stack ports share the same memory region,
97 * so that zero-copy can be implemented between them.
98 * VALE switch ports instead have separate memory regions.
100 * The netmap_ring is the userspace-visible replica of the NIC ring.
101 * Each slot has the index of a buffer (MTU-sized and residing in the
102 * mmapped region), its length and some flags. An extra 64-bit pointer
103 * is provided for user-supplied buffers in the tx path.
105 * In user space, the buffer address is computed as
106 * (char *)ring + buf_ofs + index * NETMAP_BUF_SIZE
108 * Added in NETMAP_API 11:
110 * + NIOCREGIF can request the allocation of extra spare buffers from
111 * the same memory pool. The desired number of buffers must be in
112 * nr_arg3. The ioctl may return fewer buffers, depending on memory
113 * availability. nr_arg3 will return the actual value, and, once
114 * mapped, nifp->ni_bufs_head will be the index of the first buffer.
116 * The buffers are linked to each other using the first uint32_t
117 * as the index. On close, ni_bufs_head must point to the list of
118 * buffers to be released.
120 * + NIOCREGIF can request space for extra rings (and buffers)
121 * allocated in the same memory space. The number of extra rings
122 * is in nr_arg1, and is advisory. This is a no-op on NICs where
123 * the size of the memory space is fixed.
125 * + NIOCREGIF can attach to PIPE rings sharing the same memory
126 * space with a parent device. The ifname indicates the parent device,
127 * which must already exist. Flags in nr_flags indicate if we want to
128 * bind the master or slave side, the index (from nr_ringid)
129 * is just a cookie and does not need to be sequential.
131 * + NIOCREGIF can also attach to 'monitor' rings that replicate
132 * the content of specific rings, also from the same memory space.
134 * Extra flags in nr_flags support the above functions.
135 * Application libraries may use the following naming scheme:
136 * netmap:foo all NIC ring pairs
137 * netmap:foo^ only host ring pair
138 * netmap:foo+ all NIC ring + host ring pairs
139 * netmap:foo-k the k-th NIC ring pair
140 * netmap:foo{k PIPE ring pair k, master side
141 * netmap:foo}k PIPE ring pair k, slave side
143 * Some notes about host rings:
145 * + The RX host ring is used to store those packets that the host network
146 * stack is trying to transmit through a NIC queue, but only if that queue
147 * is currently in netmap mode. Netmap will not intercept host stack mbufs
148 * designated to NIC queues that are not in netmap mode. As a consequence,
149 * registering a netmap port with netmap:foo^ is not enough to intercept
150 * mbufs in the RX host ring; the netmap port should be registered with
151 * netmap:foo*, or another registration should be done to open at least a
152 * NIC TX queue in netmap mode.
154 * + Netmap is not currently able to deal with intercepted trasmit mbufs which
155 * require offloadings like TSO, UFO, checksumming offloadings, etc. It is
156 * responsibility of the user to disable those offloadings (e.g. using
157 * ifconfig on FreeBSD or ethtool -K on Linux) for an interface that is being
158 * used in netmap mode. If the offloadings are not disabled, GSO and/or
159 * unchecksummed packets may be dropped immediately or end up in the host RX
160 * ring, and will be dropped as soon as the packet reaches another netmap
165 * struct netmap_slot is a buffer descriptor
168 uint32_t buf_idx; /* buffer index */
169 uint16_t len; /* length for this slot */
170 uint16_t flags; /* buf changed, etc. */
171 uint64_t ptr; /* pointer for indirect buffers */
175 * The following flags control how the slot is used
178 #define NS_BUF_CHANGED 0x0001 /* buf_idx changed */
180 * must be set whenever buf_idx is changed (as it might be
181 * necessary to recompute the physical address and mapping)
183 * It is also set by the kernel whenever the buf_idx is
184 * changed internally (e.g., by pipes). Applications may
185 * use this information to know when they can reuse the
186 * contents of previously prepared buffers.
189 #define NS_REPORT 0x0002 /* ask the hardware to report results */
191 * Request notification when slot is used by the hardware.
192 * Normally transmit completions are handled lazily and
193 * may be unreported. This flag lets us know when a slot
194 * has been sent (e.g. to terminate the sender).
197 #define NS_FORWARD 0x0004 /* pass packet 'forward' */
199 * (Only for physical ports, rx rings with NR_FORWARD set).
200 * Slot released to the kernel (i.e. before ring->head) with
201 * this flag set are passed to the peer ring (host/NIC),
202 * thus restoring the host-NIC connection for these slots.
203 * This supports efficient traffic monitoring or firewalling.
206 #define NS_NO_LEARN 0x0008 /* disable bridge learning */
208 * On a VALE switch, do not 'learn' the source port for
212 #define NS_INDIRECT 0x0010 /* userspace buffer */
214 * (VALE tx rings only) data is in a userspace buffer,
215 * whose address is in the 'ptr' field in the slot.
218 #define NS_MOREFRAG 0x0020 /* packet has more fragments */
221 * Set on all but the last slot of a multi-segment packet.
222 * The 'len' field refers to the individual fragment.
225 #define NS_PORT_SHIFT 8
226 #define NS_PORT_MASK (0xff << NS_PORT_SHIFT)
228 * The high 8 bits of the flag, if not zero, indicate the
229 * destination port for the VALE switch, overriding
233 #define NS_RFRAGS(_slot) ( ((_slot)->flags >> 8) & 0xff)
235 * (VALE rx rings only) the high 8 bits
236 * are the number of fragments.
243 * Netmap representation of a TX or RX ring (also known as "queue").
244 * This is a queue implemented as a fixed-size circular array.
245 * At the software level the important fields are: head, cur, tail.
249 * head first slot available for transmission.
250 * cur wakeup point. select() and poll() will unblock
251 * when 'tail' moves past 'cur'
252 * tail (readonly) first slot reserved to the kernel
254 * [head .. tail-1] can be used for new packets to send;
255 * 'head' and 'cur' must be incremented as slots are filled
256 * with new packets to be sent;
257 * 'cur' can be moved further ahead if we need more space
258 * for new transmissions. XXX todo (2014-03-12)
262 * head first valid received packet
263 * cur wakeup point. select() and poll() will unblock
264 * when 'tail' moves past 'cur'
265 * tail (readonly) first slot reserved to the kernel
267 * [head .. tail-1] contain received packets;
268 * 'head' and 'cur' must be incremented as slots are consumed
269 * and can be returned to the kernel;
270 * 'cur' can be moved further ahead if we want to wait for
271 * new packets without returning the previous ones.
273 * DATA OWNERSHIP/LOCKING:
274 * The netmap_ring, and all slots and buffers in the range
275 * [head .. tail-1] are owned by the user program;
276 * the kernel only accesses them during a netmap system call
277 * and in the user thread context.
279 * Other slots and buffers are reserved for use by the kernel
283 * buf_ofs is meant to be used through macros.
284 * It contains the offset of the buffer region from this
287 const int64_t buf_ofs;
288 const uint32_t num_slots; /* number of slots in the ring. */
289 const uint32_t nr_buf_size;
290 const uint16_t ringid;
291 const uint16_t dir; /* 0: tx, 1: rx */
293 uint32_t head; /* (u) first user slot */
294 uint32_t cur; /* (u) wakeup point */
295 uint32_t tail; /* (k) first kernel slot */
299 struct timeval ts; /* (k) time of last *sync() */
301 /* opaque room for a mutex or similar object */
302 #if !defined(_WIN32) || defined(__CYGWIN__)
303 uint8_t __attribute__((__aligned__(NM_CACHE_ALIGN))) sem[128];
305 uint8_t __declspec(align(NM_CACHE_ALIGN)) sem[128];
308 /* the slots follow. This struct has variable size */
309 struct netmap_slot slot[0]; /* array of slots. */
316 #define NR_TIMESTAMP 0x0002 /* set timestamp on *sync() */
318 * updates the 'ts' field on each netmap syscall. This saves
319 * saves a separate gettimeofday(), and is not much worse than
320 * software timestamps generated in the interrupt handler.
323 #define NR_FORWARD 0x0004 /* enable NS_FORWARD for ring */
325 * Enables the NS_FORWARD slot flag for the ring.
330 * Netmap representation of an interface and its queue(s).
331 * This is initialized by the kernel when binding a file
332 * descriptor to a port, and should be considered as readonly
333 * by user programs. The kernel never uses it.
335 * There is one netmap_if for each file descriptor on which we want
337 * select/poll operates on one or all pairs depending on the value of
338 * nmr_queueid passed on the ioctl.
341 char ni_name[IFNAMSIZ]; /* name of the interface. */
342 const uint32_t ni_version; /* API version, currently unused */
343 const uint32_t ni_flags; /* properties */
344 #define NI_PRIV_MEM 0x1 /* private memory region */
347 * The number of packet rings available in netmap mode.
348 * Physical NICs can have different numbers of tx and rx rings.
349 * Physical NICs also have a 'host' ring pair.
350 * Additionally, clients can request additional ring pairs to
351 * be used for internal communication.
353 const uint32_t ni_tx_rings; /* number of HW tx rings */
354 const uint32_t ni_rx_rings; /* number of HW rx rings */
356 uint32_t ni_bufs_head; /* head index for extra bufs */
357 uint32_t ni_spare1[5];
359 * The following array contains the offset of each netmap ring
360 * from this structure, in the following order:
361 * NIC tx rings (ni_tx_rings); host tx ring (1); extra tx rings;
362 * NIC rx rings (ni_rx_rings); host tx ring (1); extra rx rings.
364 * The area is filled up by the kernel on NIOCREGIF,
365 * and then only read by userspace code.
367 const ssize_t ring_ofs[0];
373 * ioctl names and related fields
375 * NIOCTXSYNC, NIOCRXSYNC synchronize tx or rx queues,
376 * whose identity is set in NIOCREGIF through nr_ringid.
377 * These are non blocking and take no argument.
379 * NIOCGINFO takes a struct ifreq, the interface name is the input,
380 * the outputs are number of queues and number of descriptor
381 * for each queue (useful to set number of threads etc.).
382 * The info returned is only advisory and may change before
383 * the interface is bound to a file descriptor.
385 * NIOCREGIF takes an interface name within a struct nmre,
386 * and activates netmap mode on the interface (if possible).
388 * The argument to NIOCGINFO/NIOCREGIF overlays struct ifreq so we
389 * can pass it down to other NIC-related ioctls.
391 * The actual argument (struct nmreq) has a number of options to request
392 * different functions.
393 * The following are used in NIOCREGIF when nr_cmd == 0:
396 * The name of the port (em0, valeXXX:YYY, etc.)
397 * limited to IFNAMSIZ for backward compatibility.
399 * nr_version (in/out)
400 * Must match NETMAP_API as used in the kernel, error otherwise.
401 * Always returns the desired value on output.
403 * nr_tx_slots, nr_tx_slots, nr_tx_rings, nr_rx_rings (in/out)
404 * On input, non-zero values may be used to reconfigure the port
405 * according to the requested values, but this is not guaranteed.
406 * On output the actual values in use are reported.
409 * Indicates how rings should be bound to the file descriptors.
410 * If nr_flags != 0, then the low bits (in NETMAP_RING_MASK)
411 * are used to indicate the ring number, and nr_flags specifies
412 * the actual rings to bind. NETMAP_NO_TX_POLL is unaffected.
414 * NOTE: THE FOLLOWING (nr_flags == 0) IS DEPRECATED:
415 * If nr_flags == 0, NETMAP_HW_RING and NETMAP_SW_RING control
416 * the binding as follows:
417 * 0 (default) binds all physical rings
418 * NETMAP_HW_RING | ring number binds a single ring pair
419 * NETMAP_SW_RING binds only the host tx/rx rings
421 * NETMAP_NO_TX_POLL can be OR-ed to make select()/poll() push
422 * packets on tx rings only if POLLOUT is set.
423 * The default is to push any pending packet.
425 * NETMAP_DO_RX_POLL can be OR-ed to make select()/poll() release
426 * packets on rx rings also when POLLIN is NOT set.
427 * The default is to touch the rx ring only with POLLIN.
428 * Note that this is the opposite of TX because it
429 * reflects the common usage.
431 * NOTE: NETMAP_PRIV_MEM IS DEPRECATED, use nr_arg2 instead.
432 * NETMAP_PRIV_MEM is set on return for ports that do not use
433 * the global memory allocator.
434 * This information is not significant and applications
435 * should look at the region id in nr_arg2
437 * nr_flags is the recommended mode to indicate which rings should
438 * be bound to a file descriptor. Values are NR_REG_*
440 * nr_arg1 (in) The number of extra rings to be reserved.
441 * Especially when allocating a VALE port the system only
442 * allocates the amount of memory needed for the port.
443 * If more shared memory rings are desired (e.g. for pipes),
444 * the first invocation for the same basename/allocator
445 * should specify a suitable number. Memory cannot be
446 * extended after the first allocation without closing
447 * all ports on the same region.
449 * nr_arg2 (in/out) The identity of the memory region used.
450 * On input, 0 means the system decides autonomously,
451 * other values may try to select a specific region.
452 * On return the actual value is reported.
453 * Region '1' is the global allocator, normally shared
454 * by all interfaces. Other values are private regions.
455 * If two ports the same region zero-copy is possible.
457 * nr_arg3 (in/out) number of extra buffers to be allocated.
461 * nr_cmd (in) if non-zero indicates a special command:
462 * NETMAP_BDG_ATTACH and nr_name = vale*:ifname
463 * attaches the NIC to the switch; nr_ringid specifies
464 * which rings to use. Used by vale-ctl -a ...
465 * nr_arg1 = NETMAP_BDG_HOST also attaches the host port
466 * as in vale-ctl -h ...
468 * NETMAP_BDG_DETACH and nr_name = vale*:ifname
469 * disconnects a previously attached NIC.
470 * Used by vale-ctl -d ...
473 * list the configuration of VALE switches.
475 * NETMAP_BDG_VNET_HDR
476 * Set the virtio-net header length used by the client
477 * of a VALE switch port.
480 * create a persistent VALE port with name nr_name.
481 * Used by vale-ctl -n ...
484 * delete a persistent VALE port. Used by vale-ctl -d ...
486 * nr_arg1, nr_arg2, nr_arg3 (in/out) command specific
494 * struct nmreq overlays a struct ifreq (just the name)
497 char nr_name[IFNAMSIZ];
498 uint32_t nr_version; /* API version */
499 uint32_t nr_offset; /* nifp offset in the shared region */
500 uint32_t nr_memsize; /* size of the shared region */
501 uint32_t nr_tx_slots; /* slots in tx rings */
502 uint32_t nr_rx_slots; /* slots in rx rings */
503 uint16_t nr_tx_rings; /* number of tx rings */
504 uint16_t nr_rx_rings; /* number of rx rings */
506 uint16_t nr_ringid; /* ring(s) we care about */
507 #define NETMAP_HW_RING 0x4000 /* single NIC ring pair */
508 #define NETMAP_SW_RING 0x2000 /* only host ring pair */
510 #define NETMAP_RING_MASK 0x0fff /* the ring number */
512 #define NETMAP_NO_TX_POLL 0x1000 /* no automatic txsync on poll */
514 #define NETMAP_DO_RX_POLL 0x8000 /* DO automatic rxsync on poll */
517 #define NETMAP_BDG_ATTACH 1 /* attach the NIC */
518 #define NETMAP_BDG_DETACH 2 /* detach the NIC */
519 #define NETMAP_BDG_REGOPS 3 /* register bridge callbacks */
520 #define NETMAP_BDG_LIST 4 /* get bridge's info */
521 #define NETMAP_BDG_VNET_HDR 5 /* set the port virtio-net-hdr length */
522 #define NETMAP_BDG_OFFSET NETMAP_BDG_VNET_HDR /* deprecated alias */
523 #define NETMAP_BDG_NEWIF 6 /* create a virtual port */
524 #define NETMAP_BDG_DELIF 7 /* destroy a virtual port */
525 #define NETMAP_PT_HOST_CREATE 8 /* create ptnetmap kthreads */
526 #define NETMAP_PT_HOST_DELETE 9 /* delete ptnetmap kthreads */
527 #define NETMAP_BDG_POLLING_ON 10 /* delete polling kthread */
528 #define NETMAP_BDG_POLLING_OFF 11 /* delete polling kthread */
529 #define NETMAP_VNET_HDR_GET 12 /* get the port virtio-net-hdr length */
530 #define NETMAP_POOLS_INFO_GET 13 /* get memory allocator pools info */
531 uint16_t nr_arg1; /* reserve extra rings in NIOCREGIF */
532 #define NETMAP_BDG_HOST 1 /* attach the host stack on ATTACH */
535 uint32_t nr_arg3; /* req. extra buffers in NIOCREGIF */
537 /* various modes, extends nr_ringid */
541 #define NR_REG_MASK 0xf /* values for nr_flags */
542 enum { NR_REG_DEFAULT = 0, /* backward compat, should not be used. */
547 NR_REG_PIPE_MASTER = 5,
548 NR_REG_PIPE_SLAVE = 6,
550 /* monitor uses the NR_REG to select the rings to monitor */
551 #define NR_MONITOR_TX 0x100
552 #define NR_MONITOR_RX 0x200
553 #define NR_ZCOPY_MON 0x400
554 /* request exclusive access to the selected rings */
555 #define NR_EXCLUSIVE 0x800
556 /* request ptnetmap host support */
557 #define NR_PASSTHROUGH_HOST NR_PTNETMAP_HOST /* deprecated */
558 #define NR_PTNETMAP_HOST 0x1000
559 #define NR_RX_RINGS_ONLY 0x2000
560 #define NR_TX_RINGS_ONLY 0x4000
561 /* Applications set this flag if they are able to deal with virtio-net headers,
562 * that is send/receive frames that start with a virtio-net header.
563 * If not set, NIOCREGIF will fail with netmap ports that require applications
564 * to use those headers. If the flag is set, the application can use the
565 * NETMAP_VNET_HDR_GET command to figure out the header length. */
566 #define NR_ACCEPT_VNET_HDR 0x8000
568 #define NM_BDG_NAME "vale" /* prefix for bridge port name */
571 * Windows does not have _IOWR(). _IO(), _IOW() and _IOR() are defined
572 * in ws2def.h but not sure if they are in the form we need.
573 * XXX so we redefine them
574 * in a convenient way to use for DeviceIoControl signatures
577 #undef _IO // ws2def.h
578 #define _WIN_NM_IOCTL_TYPE 40000
579 #define _IO(_c, _n) CTL_CODE(_WIN_NM_IOCTL_TYPE, ((_n) + 0x800) , \
580 METHOD_BUFFERED, FILE_ANY_ACCESS )
581 #define _IO_direct(_c, _n) CTL_CODE(_WIN_NM_IOCTL_TYPE, ((_n) + 0x800) , \
582 METHOD_OUT_DIRECT, FILE_ANY_ACCESS )
584 #define _IOWR(_c, _n, _s) _IO(_c, _n)
586 /* We havesome internal sysctl in addition to the externally visible ones */
587 #define NETMAP_MMAP _IO_direct('i', 160) // note METHOD_OUT_DIRECT
588 #define NETMAP_POLL _IO('i', 162)
590 /* and also two setsockopt for sysctl emulation */
591 #define NETMAP_SETSOCKOPT _IO('i', 140)
592 #define NETMAP_GETSOCKOPT _IO('i', 141)
595 //These linknames are for the Netmap Core Driver
596 #define NETMAP_NT_DEVICE_NAME L"\\Device\\NETMAP"
597 #define NETMAP_DOS_DEVICE_NAME L"\\DosDevices\\netmap"
599 //Definition of a structure used to pass a virtual address within an IOCTL
600 typedef struct _MEMORY_ENTRY {
601 PVOID pUsermodeVirtualAddress;
602 } MEMORY_ENTRY, *PMEMORY_ENTRY;
604 typedef struct _POLL_REQUEST_DATA {
613 * FreeBSD uses the size value embedded in the _IOWR to determine
614 * how much to copy in/out. So we need it to match the actual
615 * data structure we pass. We put some spares in the structure
616 * to ease compatibility with other versions
618 #define NIOCGINFO _IOWR('i', 145, struct nmreq) /* return IF info */
619 #define NIOCREGIF _IOWR('i', 146, struct nmreq) /* interface register */
620 #define NIOCTXSYNC _IO('i', 148) /* sync tx queues */
621 #define NIOCRXSYNC _IO('i', 149) /* sync rx queues */
622 #define NIOCCONFIG _IOWR('i',150, struct nm_ifreq) /* for ext. modules */
623 #endif /* !NIOCREGIF */
627 * Helper functions for kernel and userspace
631 * check if space is available in the ring.
634 nm_ring_empty(struct netmap_ring *ring)
636 return (ring->cur == ring->tail);
640 * Opaque structure that is passed to an external kernel
641 * module via ioctl(fd, NIOCCONFIG, req) for a user-owned
642 * bridge port (at this point ephemeral VALE interface).
644 #define NM_IFRDATA_LEN 256
646 char nifr_name[IFNAMSIZ];
647 char data[NM_IFRDATA_LEN];
650 #endif /* _NET_NETMAP_H_ */