1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (C) 2011-2016 Universita` di Pisa
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 *   1. Redistributions of source code must retain the above copyright
12 *      notice, this list of conditions and the following disclaimer.
13 *   2. Redistributions in binary form must reproduce the above copyright
14 *      notice, this list of conditions and the following disclaimer in the
15 *      documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30/*
31 *
32 * Functions and macros to manipulate netmap structures and packets
33 * in userspace. See netmap(4) for more information.
34 *
35 * The address of the struct netmap_if, say nifp, is computed from the
36 * value returned from ioctl(.., NIOCREG, ...) and the mmap region:
37 *	ioctl(fd, NIOCREG, &req);
38 *	mem = mmap(0, ... );
39 *	nifp = NETMAP_IF(mem, req.nr_nifp);
40 *		(so simple, we could just do it manually)
41 *
42 * From there:
43 *	struct netmap_ring *NETMAP_TXRING(nifp, index)
44 *	struct netmap_ring *NETMAP_RXRING(nifp, index)
45 *		we can access ring->cur, ring->head, ring->tail, etc.
46 *
47 *	ring->slot[i] gives us the i-th slot (we can access
48 *		directly len, flags, buf_idx)
49 *
50 *	char *buf = NETMAP_BUF(ring, x) returns a pointer to
51 *		the buffer numbered x
52 *
53 * All ring indexes (head, cur, tail) should always move forward.
54 * To compute the next index in a circular ring you can use
55 *	i = nm_ring_next(ring, i);
56 *
57 * To ease porting apps from pcap to netmap we supply a few functions
58 * that can be called to open, close, read and write on netmap in a way
59 * similar to libpcap. Note that the read/write function depend on
60 * an ioctl()/select()/poll() being issued to refill rings or push
61 * packets out.
62 *
63 * In order to use these, include #define NETMAP_WITH_LIBS
64 * in the source file that invokes these functions.
65 */
66
67#ifndef _NET_NETMAP_USER_H_
68#define _NET_NETMAP_USER_H_
69
70#define NETMAP_DEVICE_NAME "/dev/netmap"
71
72#ifdef __CYGWIN__
73/*
74 * we can compile userspace apps with either cygwin or msvc,
75 * and we use _WIN32 to identify windows specific code
76 */
77#ifndef _WIN32
78#define _WIN32
79#endif	/* _WIN32 */
80
81#endif	/* __CYGWIN__ */
82
83#ifdef _WIN32
84#undef NETMAP_DEVICE_NAME
85#define NETMAP_DEVICE_NAME "/proc/sys/DosDevices/Global/netmap"
86#include <windows.h>
87#include <WinDef.h>
88#include <sys/cygwin.h>
89#endif /* _WIN32 */
90
91#include <stdint.h>
92#include <sys/socket.h>		/* apple needs sockaddr */
93#include <net/if.h>		/* IFNAMSIZ */
94#include <ctype.h>
95#include <string.h>	/* memset */
96#include <sys/time.h>   /* gettimeofday */
97
98#ifndef likely
99#define likely(x)	__builtin_expect(!!(x), 1)
100#define unlikely(x)	__builtin_expect(!!(x), 0)
101#endif /* likely and unlikely */
102
103#include <net/netmap.h>
104
105/* helper macro */
106#define _NETMAP_OFFSET(type, ptr, offset) \
107	((type)(void *)((char *)(ptr) + (offset)))
108
109#define NETMAP_IF(_base, _ofs)	_NETMAP_OFFSET(struct netmap_if *, _base, _ofs)
110
111#define NETMAP_TXRING(nifp, index) _NETMAP_OFFSET(struct netmap_ring *, \
112	nifp, (nifp)->ring_ofs[index] )
113
114#define NETMAP_RXRING(nifp, index) _NETMAP_OFFSET(struct netmap_ring *,	\
115	nifp, (nifp)->ring_ofs[index + (nifp)->ni_tx_rings + 		\
116		(nifp)->ni_host_tx_rings] )
117
118#define NETMAP_BUF(ring, index)				\
119	((char *)(ring) + (ring)->buf_ofs + ((size_t)(index)*(ring)->nr_buf_size))
120
121#define NETMAP_BUF_IDX(ring, buf)			\
122	( ((char *)(buf) - ((char *)(ring) + (ring)->buf_ofs) ) / \
123		(ring)->nr_buf_size )
124
125/* read the offset field in a ring's slot */
126#define NETMAP_ROFFSET(ring, slot)			\
127	((slot)->ptr & (ring)->offset_mask)
128
129/* update the offset field in a ring's slot */
130#define NETMAP_WOFFSET(ring, slot, offset)		\
131	do { (slot)->ptr = ((slot)->ptr & ~(ring)->offset_mask) | \
132		((offset) & (ring)->offset_mask); } while (0)
133
134/* obtain the start of the buffer pointed to by  a ring's slot, taking the
135 * offset field into account
136 */
137#define NETMAP_BUF_OFFSET(ring, slot)			\
138	(NETMAP_BUF(ring, (slot)->buf_idx) + NETMAP_ROFFSET(ring, slot))
139
140
141static inline uint32_t
142nm_ring_next(struct netmap_ring *r, uint32_t i)
143{
144	return ( unlikely(i + 1 == r->num_slots) ? 0 : i + 1);
145}
146
147
148/*
149 * Return 1 if we have pending transmissions in the tx ring.
150 * When everything is complete ring->head = ring->tail + 1 (modulo ring size)
151 */
152static inline int
153nm_tx_pending(struct netmap_ring *r)
154{
155	return nm_ring_next(r, r->tail) != r->head;
156}
157
158/* Compute the number of slots available in the netmap ring. We use
159 * ring->head as explained in the comment above nm_ring_empty(). */
160static inline uint32_t
161nm_ring_space(struct netmap_ring *ring)
162{
163        int ret = ring->tail - ring->head;
164        if (ret < 0)
165                ret += ring->num_slots;
166        return ret;
167}
168
169#ifndef ND /* debug macros */
170/* debug support */
171#define ND(_fmt, ...) do {} while(0)
172#define D(_fmt, ...)						\
173	do {							\
174		struct timeval _t0;				\
175		gettimeofday(&_t0, NULL);			\
176		fprintf(stderr, "%03d.%06d %s [%d] " _fmt "\n",	\
177		    (int)(_t0.tv_sec % 1000), (int)_t0.tv_usec,	\
178		    __FUNCTION__, __LINE__, ##__VA_ARGS__);	\
179        } while (0)
180
181/* Rate limited version of "D", lps indicates how many per second */
182#define RD(lps, format, ...)                                    \
183    do {                                                        \
184        static int __t0, __cnt;                                 \
185        struct timeval __xxts;                                  \
186        gettimeofday(&__xxts, NULL);                            \
187        if (__t0 != __xxts.tv_sec) {                            \
188            __t0 = __xxts.tv_sec;                               \
189            __cnt = 0;                                          \
190        }                                                       \
191        if (__cnt++ < lps) {                                    \
192            D(format, ##__VA_ARGS__);                           \
193        }                                                       \
194    } while (0)
195#endif
196
197/*
198 * this is a slightly optimized copy routine which rounds
199 * to multiple of 64 bytes and is often faster than dealing
200 * with other odd sizes. We assume there is enough room
201 * in the source and destination buffers.
202 */
203static inline void
204nm_pkt_copy(const void *_src, void *_dst, int l)
205{
206	const uint64_t *src = (const uint64_t *)_src;
207	uint64_t *dst = (uint64_t *)_dst;
208
209	if (unlikely(l >= 1024 || l % 64)) {
210		memcpy(dst, src, l);
211		return;
212	}
213	for (; likely(l > 0); l-=64) {
214		*dst++ = *src++;
215		*dst++ = *src++;
216		*dst++ = *src++;
217		*dst++ = *src++;
218		*dst++ = *src++;
219		*dst++ = *src++;
220		*dst++ = *src++;
221		*dst++ = *src++;
222	}
223}
224
225#ifdef NETMAP_WITH_LIBS
226/*
227 * Support for simple I/O libraries.
228 * Include other system headers required for compiling this.
229 */
230
231#ifndef HAVE_NETMAP_WITH_LIBS
232#define HAVE_NETMAP_WITH_LIBS
233
234#include <stdio.h>
235#include <sys/time.h>
236#include <sys/mman.h>
237#include <sys/ioctl.h>
238#include <sys/errno.h>	/* EINVAL */
239#include <fcntl.h>	/* O_RDWR */
240#include <unistd.h>	/* close() */
241#include <signal.h>
242#include <stdlib.h>
243
244struct nm_pkthdr {	/* first part is the same as pcap_pkthdr */
245	struct timeval	ts;
246	uint32_t	caplen;
247	uint32_t	len;
248
249	uint64_t flags;	/* NM_MORE_PKTS etc */
250#define NM_MORE_PKTS	1
251	struct nm_desc *d;
252	struct netmap_slot *slot;
253	uint8_t *buf;
254};
255
256struct nm_stat {	/* same as pcap_stat	*/
257	u_int	ps_recv;
258	u_int	ps_drop;
259	u_int	ps_ifdrop;
260#ifdef WIN32 /* XXX or _WIN32 ? */
261	u_int	bs_capt;
262#endif /* WIN32 */
263};
264
265#define NM_ERRBUF_SIZE	512
266
267struct nm_desc {
268	struct nm_desc *self; /* point to self if netmap. */
269	int fd;
270	void *mem;
271	size_t memsize;
272	int done_mmap;	/* set if mem is the result of mmap */
273	struct netmap_if * const nifp;
274	uint16_t first_tx_ring, last_tx_ring, cur_tx_ring;
275	uint16_t first_rx_ring, last_rx_ring, cur_rx_ring;
276	struct nmreq req;	/* also contains the nr_name = ifname */
277	struct nm_pkthdr hdr;
278
279	/*
280	 * The memory contains netmap_if, rings and then buffers.
281	 * Given a pointer (e.g. to nm_inject) we can compare with
282	 * mem/buf_start/buf_end to tell if it is a buffer or
283	 * some other descriptor in our region.
284	 * We also store a pointer to some ring as it helps in the
285	 * translation from buffer indexes to addresses.
286	 */
287	struct netmap_ring * const some_ring;
288	void * const buf_start;
289	void * const buf_end;
290	/* parameters from pcap_open_live */
291	int snaplen;
292	int promisc;
293	int to_ms;
294	char *errbuf;
295
296	/* save flags so we can restore them on close */
297	uint32_t if_flags;
298        uint32_t if_reqcap;
299        uint32_t if_curcap;
300
301	struct nm_stat st;
302	char msg[NM_ERRBUF_SIZE];
303};
304
305/*
306 * when the descriptor is open correctly, d->self == d
307 * Eventually we should also use some magic number.
308 */
309#define P2NMD(p)		((const struct nm_desc *)(p))
310#define IS_NETMAP_DESC(d)	((d) && P2NMD(d)->self == P2NMD(d))
311#define NETMAP_FD(d)		(P2NMD(d)->fd)
312
313/*
314 * The callback, invoked on each received packet. Same as libpcap
315 */
316typedef void (*nm_cb_t)(u_char *, const struct nm_pkthdr *, const u_char *d);
317
318/*
319 *--- the pcap-like API ---
320 *
321 * nm_open() opens a file descriptor, binds to a port and maps memory.
322 *
323 * ifname	(netmap:foo or vale:foo) is the port name
324 *		a suffix can indicate the following:
325 *		^		bind the host (sw) ring pair
326 *		*		bind host and NIC ring pairs
327 *		-NN		bind individual NIC ring pair
328 *		{NN		bind master side of pipe NN
329 *		}NN		bind slave side of pipe NN
330 *		a suffix starting with / and the following flags,
331 *		in any order:
332 *		x		exclusive access
333 *		z		zero copy monitor (both tx and rx)
334 *		t		monitor tx side (copy monitor)
335 *		r		monitor rx side (copy monitor)
336 *		R		bind only RX ring(s)
337 *		T		bind only TX ring(s)
338 *
339 * req		provides the initial values of nmreq before parsing ifname.
340 *		Remember that the ifname parsing will override the ring
341 *		number in nm_ringid, and part of nm_flags;
342 * flags	special functions, normally 0
343 *		indicates which fields of *arg are significant
344 * arg		special functions, normally NULL
345 *		if passed a netmap_desc with mem != NULL,
346 *		use that memory instead of mmap.
347 */
348
349static struct nm_desc *nm_open(const char *ifname, const struct nmreq *req,
350	uint64_t flags, const struct nm_desc *arg);
351
352/*
353 * nm_open can import some fields from the parent descriptor.
354 * These flags control which ones.
355 * Also in flags you can specify NETMAP_NO_TX_POLL and NETMAP_DO_RX_POLL,
356 * which set the initial value for these flags.
357 * Note that the 16 low bits of the flags are reserved for data
358 * that may go into the nmreq.
359 */
360enum {
361	NM_OPEN_NO_MMAP =	0x040000, /* reuse mmap from parent */
362	NM_OPEN_IFNAME =	0x080000, /* nr_name, nr_ringid, nr_flags */
363	NM_OPEN_ARG1 =		0x100000,
364	NM_OPEN_ARG2 =		0x200000,
365	NM_OPEN_ARG3 =		0x400000,
366	NM_OPEN_RING_CFG =	0x800000, /* tx|rx rings|slots */
367};
368
369
370/*
371 * nm_close()	closes and restores the port to its previous state
372 */
373
374static int nm_close(struct nm_desc *);
375
376/*
377 * nm_mmap()    do mmap or inherit from parent if the nr_arg2
378 *              (memory block) matches.
379 */
380
381static int nm_mmap(struct nm_desc *, const struct nm_desc *);
382
383/*
384 * nm_inject() is the same as pcap_inject()
385 * nm_dispatch() is the same as pcap_dispatch()
386 * nm_nextpkt() is the same as pcap_next()
387 */
388
389static int nm_inject(struct nm_desc *, const void *, size_t);
390static int nm_dispatch(struct nm_desc *, int, nm_cb_t, u_char *);
391static u_char *nm_nextpkt(struct nm_desc *, struct nm_pkthdr *);
392
393#ifdef _WIN32
394
395intptr_t _get_osfhandle(int); /* defined in io.h in windows */
396
397/*
398 * In windows we do not have yet native poll support, so we keep track
399 * of file descriptors associated to netmap ports to emulate poll on
400 * them and fall back on regular poll on other file descriptors.
401 */
402struct win_netmap_fd_list {
403	struct win_netmap_fd_list *next;
404	int win_netmap_fd;
405	HANDLE win_netmap_handle;
406};
407
408/*
409 * list head containing all the netmap opened fd and their
410 * windows HANDLE counterparts
411 */
412static struct win_netmap_fd_list *win_netmap_fd_list_head;
413
414static void
415win_insert_fd_record(int fd)
416{
417	struct win_netmap_fd_list *curr;
418
419	for (curr = win_netmap_fd_list_head; curr; curr = curr->next) {
420		if (fd == curr->win_netmap_fd) {
421			return;
422		}
423	}
424	curr = calloc(1, sizeof(*curr));
425	curr->next = win_netmap_fd_list_head;
426	curr->win_netmap_fd = fd;
427	curr->win_netmap_handle = IntToPtr(_get_osfhandle(fd));
428	win_netmap_fd_list_head = curr;
429}
430
431void
432win_remove_fd_record(int fd)
433{
434	struct win_netmap_fd_list *curr = win_netmap_fd_list_head;
435	struct win_netmap_fd_list *prev = NULL;
436	for (; curr ; prev = curr, curr = curr->next) {
437		if (fd != curr->win_netmap_fd)
438			continue;
439		/* found the entry */
440		if (prev == NULL) { /* we are freeing the first entry */
441			win_netmap_fd_list_head = curr->next;
442		} else {
443			prev->next = curr->next;
444		}
445		free(curr);
446		break;
447	}
448}
449
450
451HANDLE
452win_get_netmap_handle(int fd)
453{
454	struct win_netmap_fd_list *curr;
455
456	for (curr = win_netmap_fd_list_head; curr; curr = curr->next) {
457		if (fd == curr->win_netmap_fd) {
458			return curr->win_netmap_handle;
459		}
460	}
461	return NULL;
462}
463
464/*
465 * we need to wrap ioctl and mmap, at least for the netmap file descriptors
466 */
467
468/*
469 * use this function only from netmap_user.h internal functions
470 * same as ioctl, returns 0 on success and -1 on error
471 */
472static int
473win_nm_ioctl_internal(HANDLE h, int32_t ctlCode, void *arg)
474{
475	DWORD bReturn = 0, szIn, szOut;
476	BOOL ioctlReturnStatus;
477	void *inParam = arg, *outParam = arg;
478
479	switch (ctlCode) {
480	case NETMAP_POLL:
481		szIn = sizeof(POLL_REQUEST_DATA);
482		szOut = sizeof(POLL_REQUEST_DATA);
483		break;
484	case NETMAP_MMAP:
485		szIn = 0;
486		szOut = sizeof(void*);
487		inParam = NULL; /* nothing on input */
488		break;
489	case NIOCTXSYNC:
490	case NIOCRXSYNC:
491		szIn = 0;
492		szOut = 0;
493		break;
494	case NIOCREGIF:
495		szIn = sizeof(struct nmreq);
496		szOut = sizeof(struct nmreq);
497		break;
498	case NIOCCONFIG:
499		D("unsupported NIOCCONFIG!");
500		return -1;
501
502	default: /* a regular ioctl */
503		D("invalid ioctl %x on netmap fd", ctlCode);
504		return -1;
505	}
506
507	ioctlReturnStatus = DeviceIoControl(h,
508				ctlCode, inParam, szIn,
509				outParam, szOut,
510				&bReturn, NULL);
511	// XXX note windows returns 0 on error or async call, 1 on success
512	// we could call GetLastError() to figure out what happened
513	return ioctlReturnStatus ? 0 : -1;
514}
515
516/*
517 * this function is what must be called from user-space programs
518 * same as ioctl, returns 0 on success and -1 on error
519 */
520static int
521win_nm_ioctl(int fd, int32_t ctlCode, void *arg)
522{
523	HANDLE h = win_get_netmap_handle(fd);
524
525	if (h == NULL) {
526		return ioctl(fd, ctlCode, arg);
527	} else {
528		return win_nm_ioctl_internal(h, ctlCode, arg);
529	}
530}
531
532#define ioctl win_nm_ioctl /* from now on, within this file ... */
533
534/*
535 * We cannot use the native mmap on windows
536 * The only parameter used is "fd", the other ones are just declared to
537 * make this signature comparable to the FreeBSD/Linux one
538 */
539static void *
540win32_mmap_emulated(void *addr, size_t length, int prot, int flags, int fd, int32_t offset)
541{
542	HANDLE h = win_get_netmap_handle(fd);
543
544	if (h == NULL) {
545		return mmap(addr, length, prot, flags, fd, offset);
546	} else {
547		MEMORY_ENTRY ret;
548
549		return win_nm_ioctl_internal(h, NETMAP_MMAP, &ret) ?
550			NULL : ret.pUsermodeVirtualAddress;
551	}
552}
553
554#define mmap win32_mmap_emulated
555
556#include <sys/poll.h> /* XXX needed to use the structure pollfd */
557
558static int
559win_nm_poll(struct pollfd *fds, int nfds, int timeout)
560{
561	HANDLE h;
562
563	if (nfds != 1 || fds == NULL || (h = win_get_netmap_handle(fds->fd)) == NULL) {;
564		return poll(fds, nfds, timeout);
565	} else {
566		POLL_REQUEST_DATA prd;
567
568		prd.timeout = timeout;
569		prd.events = fds->events;
570
571		win_nm_ioctl_internal(h, NETMAP_POLL, &prd);
572		if ((prd.revents == POLLERR) || (prd.revents == STATUS_TIMEOUT)) {
573			return -1;
574		}
575		return 1;
576	}
577}
578
579#define poll win_nm_poll
580
581static int
582win_nm_open(char* pathname, int flags)
583{
584
585	if (strcmp(pathname, NETMAP_DEVICE_NAME) == 0) {
586		int fd = open(NETMAP_DEVICE_NAME, O_RDWR);
587		if (fd < 0) {
588			return -1;
589		}
590
591		win_insert_fd_record(fd);
592		return fd;
593	} else {
594		return open(pathname, flags);
595	}
596}
597
598#define open win_nm_open
599
600static int
601win_nm_close(int fd)
602{
603	if (fd != -1) {
604		close(fd);
605		if (win_get_netmap_handle(fd) != NULL) {
606			win_remove_fd_record(fd);
607		}
608	}
609	return 0;
610}
611
612#define close win_nm_close
613
614#endif /* _WIN32 */
615
616static int
617nm_is_identifier(const char *s, const char *e)
618{
619	for (; s != e; s++) {
620		if (!isalnum(*s) && *s != '_') {
621			return 0;
622		}
623	}
624
625	return 1;
626}
627
628#define MAXERRMSG 80
629static int
630nm_parse(const char *ifname, struct nm_desc *d, char *err)
631{
632	int is_vale;
633	const char *port = NULL;
634	const char *vpname = NULL;
635	u_int namelen;
636	uint32_t nr_ringid = 0, nr_flags;
637	char errmsg[MAXERRMSG] = "", *tmp;
638	long num;
639	uint16_t nr_arg2 = 0;
640	enum { P_START, P_RNGSFXOK, P_GETNUM, P_FLAGS, P_FLAGSOK, P_MEMID } p_state;
641
642	errno = 0;
643
644	is_vale = (ifname[0] == 'v');
645	if (is_vale) {
646		port = index(ifname, ':');
647		if (port == NULL) {
648			snprintf(errmsg, MAXERRMSG,
649				 "missing ':' in vale name");
650			goto fail;
651		}
652
653		if (!nm_is_identifier(ifname + 4, port)) {
654			snprintf(errmsg, MAXERRMSG, "invalid bridge name");
655			goto fail;
656		}
657
658		vpname = ++port;
659	} else {
660		ifname += 7;
661		port = ifname;
662	}
663
664	/* scan for a separator */
665	for (; *port && !index("-*^{}/@", *port); port++)
666		;
667
668	if (is_vale && !nm_is_identifier(vpname, port)) {
669		snprintf(errmsg, MAXERRMSG, "invalid bridge port name");
670		goto fail;
671	}
672
673	namelen = port - ifname;
674	if (namelen >= sizeof(d->req.nr_name)) {
675		snprintf(errmsg, MAXERRMSG, "name too long");
676		goto fail;
677	}
678	memcpy(d->req.nr_name, ifname, namelen);
679	d->req.nr_name[namelen] = '\0';
680
681	p_state = P_START;
682	nr_flags = NR_REG_ALL_NIC; /* default for no suffix */
683	while (*port) {
684		switch (p_state) {
685		case P_START:
686			switch (*port) {
687			case '^': /* only SW ring */
688				nr_flags = NR_REG_SW;
689				p_state = P_RNGSFXOK;
690				break;
691			case '*': /* NIC and SW */
692				nr_flags = NR_REG_NIC_SW;
693				p_state = P_RNGSFXOK;
694				break;
695			case '-': /* one NIC ring pair */
696				nr_flags = NR_REG_ONE_NIC;
697				p_state = P_GETNUM;
698				break;
699			case '{': /* pipe (master endpoint) */
700				nr_flags = NR_REG_PIPE_MASTER;
701				p_state = P_GETNUM;
702				break;
703			case '}': /* pipe (slave endpoint) */
704				nr_flags = NR_REG_PIPE_SLAVE;
705				p_state = P_GETNUM;
706				break;
707			case '/': /* start of flags */
708				p_state = P_FLAGS;
709				break;
710			case '@': /* start of memid */
711				p_state = P_MEMID;
712				break;
713			default:
714				snprintf(errmsg, MAXERRMSG, "unknown modifier: '%c'", *port);
715				goto fail;
716			}
717			port++;
718			break;
719		case P_RNGSFXOK:
720			switch (*port) {
721			case '/':
722				p_state = P_FLAGS;
723				break;
724			case '@':
725				p_state = P_MEMID;
726				break;
727			default:
728				snprintf(errmsg, MAXERRMSG, "unexpected character: '%c'", *port);
729				goto fail;
730			}
731			port++;
732			break;
733		case P_GETNUM:
734			num = strtol(port, &tmp, 10);
735			if (num < 0 || num >= NETMAP_RING_MASK) {
736				snprintf(errmsg, MAXERRMSG, "'%ld' out of range [0, %d)",
737						num, NETMAP_RING_MASK);
738				goto fail;
739			}
740			port = tmp;
741			nr_ringid = num & NETMAP_RING_MASK;
742			p_state = P_RNGSFXOK;
743			break;
744		case P_FLAGS:
745		case P_FLAGSOK:
746			if (*port == '@') {
747				port++;
748				p_state = P_MEMID;
749				break;
750			}
751			switch (*port) {
752			case 'x':
753				nr_flags |= NR_EXCLUSIVE;
754				break;
755			case 'z':
756				nr_flags |= NR_ZCOPY_MON;
757				break;
758			case 't':
759				nr_flags |= NR_MONITOR_TX;
760				break;
761			case 'r':
762				nr_flags |= NR_MONITOR_RX;
763				break;
764			case 'R':
765				nr_flags |= NR_RX_RINGS_ONLY;
766				break;
767			case 'T':
768				nr_flags |= NR_TX_RINGS_ONLY;
769				break;
770			default:
771				snprintf(errmsg, MAXERRMSG, "unrecognized flag: '%c'", *port);
772				goto fail;
773			}
774			port++;
775			p_state = P_FLAGSOK;
776			break;
777		case P_MEMID:
778			if (nr_arg2 != 0) {
779				snprintf(errmsg, MAXERRMSG, "double setting of memid");
780				goto fail;
781			}
782			num = strtol(port, &tmp, 10);
783			if (num <= 0) {
784				snprintf(errmsg, MAXERRMSG, "invalid memid %ld, must be >0", num);
785				goto fail;
786			}
787			port = tmp;
788			nr_arg2 = num;
789			p_state = P_RNGSFXOK;
790			break;
791		}
792	}
793	if (p_state != P_START && p_state != P_RNGSFXOK && p_state != P_FLAGSOK) {
794		snprintf(errmsg, MAXERRMSG, "unexpected end of port name");
795		goto fail;
796	}
797	ND("flags: %s %s %s %s",
798			(nr_flags & NR_EXCLUSIVE) ? "EXCLUSIVE" : "",
799			(nr_flags & NR_ZCOPY_MON) ? "ZCOPY_MON" : "",
800			(nr_flags & NR_MONITOR_TX) ? "MONITOR_TX" : "",
801			(nr_flags & NR_MONITOR_RX) ? "MONITOR_RX" : "");
802
803	d->req.nr_flags |= nr_flags;
804	d->req.nr_ringid |= nr_ringid;
805	d->req.nr_arg2 = nr_arg2;
806
807	d->self = d;
808
809	return 0;
810fail:
811	if (!errno)
812		errno = EINVAL;
813	if (err)
814		strncpy(err, errmsg, MAXERRMSG);
815	return -1;
816}
817
818/*
819 * Try to open, return descriptor if successful, NULL otherwise.
820 * An invalid netmap name will return errno = 0;
821 * You can pass a pointer to a pre-filled nm_desc to add special
822 * parameters. Flags is used as follows
823 * NM_OPEN_NO_MMAP	use the memory from arg, only XXX avoid mmap
824 *			if the nr_arg2 (memory block) matches.
825 * NM_OPEN_ARG1		use req.nr_arg1 from arg
826 * NM_OPEN_ARG2		use req.nr_arg2 from arg
827 * NM_OPEN_RING_CFG	user ring config from arg
828 */
829static struct nm_desc *
830nm_open(const char *ifname, const struct nmreq *req,
831	uint64_t new_flags, const struct nm_desc *arg)
832{
833	struct nm_desc *d = NULL;
834	const struct nm_desc *parent = arg;
835	char errmsg[MAXERRMSG] = "";
836	uint32_t nr_reg;
837
838	if (strncmp(ifname, "netmap:", 7) &&
839			strncmp(ifname, NM_BDG_NAME, strlen(NM_BDG_NAME))) {
840		errno = 0; /* name not recognised, not an error */
841		return NULL;
842	}
843
844	d = (struct nm_desc *)calloc(1, sizeof(*d));
845	if (d == NULL) {
846		snprintf(errmsg, MAXERRMSG, "nm_desc alloc failure");
847		errno = ENOMEM;
848		return NULL;
849	}
850	d->self = d;	/* set this early so nm_close() works */
851	d->fd = open(NETMAP_DEVICE_NAME, O_RDWR);
852	if (d->fd < 0) {
853		snprintf(errmsg, MAXERRMSG, "cannot open /dev/netmap: %s", strerror(errno));
854		goto fail;
855	}
856
857	if (req)
858		d->req = *req;
859
860	if (!(new_flags & NM_OPEN_IFNAME)) {
861		if (nm_parse(ifname, d, errmsg) < 0)
862			goto fail;
863	}
864
865	d->req.nr_version = NETMAP_API;
866	d->req.nr_ringid &= NETMAP_RING_MASK;
867
868	/* optionally import info from parent */
869	if (IS_NETMAP_DESC(parent) && new_flags) {
870		if (new_flags & NM_OPEN_ARG1)
871			D("overriding ARG1 %d", parent->req.nr_arg1);
872		d->req.nr_arg1 = new_flags & NM_OPEN_ARG1 ?
873			parent->req.nr_arg1 : 4;
874		if (new_flags & NM_OPEN_ARG2) {
875			D("overriding ARG2 %d", parent->req.nr_arg2);
876			d->req.nr_arg2 =  parent->req.nr_arg2;
877		}
878		if (new_flags & NM_OPEN_ARG3)
879			D("overriding ARG3 %d", parent->req.nr_arg3);
880		d->req.nr_arg3 = new_flags & NM_OPEN_ARG3 ?
881			parent->req.nr_arg3 : 0;
882		if (new_flags & NM_OPEN_RING_CFG) {
883			D("overriding RING_CFG");
884			d->req.nr_tx_slots = parent->req.nr_tx_slots;
885			d->req.nr_rx_slots = parent->req.nr_rx_slots;
886			d->req.nr_tx_rings = parent->req.nr_tx_rings;
887			d->req.nr_rx_rings = parent->req.nr_rx_rings;
888		}
889		if (new_flags & NM_OPEN_IFNAME) {
890			D("overriding ifname %s ringid 0x%x flags 0x%x",
891				parent->req.nr_name, parent->req.nr_ringid,
892				parent->req.nr_flags);
893			memcpy(d->req.nr_name, parent->req.nr_name,
894				sizeof(d->req.nr_name));
895			d->req.nr_ringid = parent->req.nr_ringid;
896			d->req.nr_flags = parent->req.nr_flags;
897		}
898	}
899	/* add the *XPOLL flags */
900	d->req.nr_ringid |= new_flags & (NETMAP_NO_TX_POLL | NETMAP_DO_RX_POLL);
901
902	if (ioctl(d->fd, NIOCREGIF, &d->req)) {
903		snprintf(errmsg, MAXERRMSG, "NIOCREGIF failed: %s", strerror(errno));
904		goto fail;
905	}
906
907	nr_reg = d->req.nr_flags & NR_REG_MASK;
908
909	if (nr_reg == NR_REG_SW) { /* host stack */
910		d->first_tx_ring = d->last_tx_ring = d->req.nr_tx_rings;
911		d->first_rx_ring = d->last_rx_ring = d->req.nr_rx_rings;
912	} else if (nr_reg ==  NR_REG_ALL_NIC) { /* only nic */
913		d->first_tx_ring = 0;
914		d->first_rx_ring = 0;
915		d->last_tx_ring = d->req.nr_tx_rings - 1;
916		d->last_rx_ring = d->req.nr_rx_rings - 1;
917	} else if (nr_reg ==  NR_REG_NIC_SW) {
918		d->first_tx_ring = 0;
919		d->first_rx_ring = 0;
920		d->last_tx_ring = d->req.nr_tx_rings;
921		d->last_rx_ring = d->req.nr_rx_rings;
922	} else if (nr_reg == NR_REG_ONE_NIC) {
923		/* XXX check validity */
924		d->first_tx_ring = d->last_tx_ring =
925		d->first_rx_ring = d->last_rx_ring = d->req.nr_ringid & NETMAP_RING_MASK;
926	} else { /* pipes */
927		d->first_tx_ring = d->last_tx_ring = 0;
928		d->first_rx_ring = d->last_rx_ring = 0;
929	}
930
931        /* if parent is defined, do nm_mmap() even if NM_OPEN_NO_MMAP is set */
932	if ((!(new_flags & NM_OPEN_NO_MMAP) || parent) && nm_mmap(d, parent)) {
933	        snprintf(errmsg, MAXERRMSG, "mmap failed: %s", strerror(errno));
934		goto fail;
935	}
936
937
938#ifdef DEBUG_NETMAP_USER
939    { /* debugging code */
940	int i;
941
942	D("%s tx %d .. %d %d rx %d .. %d %d", ifname,
943		d->first_tx_ring, d->last_tx_ring, d->req.nr_tx_rings,
944                d->first_rx_ring, d->last_rx_ring, d->req.nr_rx_rings);
945	for (i = 0; i <= d->req.nr_tx_rings; i++) {
946		struct netmap_ring *r = NETMAP_TXRING(d->nifp, i);
947		D("TX%d %p h %d c %d t %d", i, r, r->head, r->cur, r->tail);
948	}
949	for (i = 0; i <= d->req.nr_rx_rings; i++) {
950		struct netmap_ring *r = NETMAP_RXRING(d->nifp, i);
951		D("RX%d %p h %d c %d t %d", i, r, r->head, r->cur, r->tail);
952	}
953    }
954#endif /* debugging */
955
956	d->cur_tx_ring = d->first_tx_ring;
957	d->cur_rx_ring = d->first_rx_ring;
958	return d;
959
960fail:
961	nm_close(d);
962	if (errmsg[0])
963		D("%s %s", errmsg, ifname);
964	if (errno == 0)
965		errno = EINVAL;
966	return NULL;
967}
968
969
970static int
971nm_close(struct nm_desc *d)
972{
973	/*
974	 * ugly trick to avoid unused warnings
975	 */
976	static void *__xxzt[] __attribute__ ((unused))  =
977		{ (void *)nm_open, (void *)nm_inject,
978		  (void *)nm_dispatch, (void *)nm_nextpkt } ;
979
980	if (d == NULL || d->self != d)
981		return EINVAL;
982	if (d->done_mmap && d->mem)
983		munmap(d->mem, d->memsize);
984	if (d->fd != -1) {
985		close(d->fd);
986	}
987
988	bzero((char *)d, sizeof(*d));
989	free(d);
990	return 0;
991}
992
993
994static int
995nm_mmap(struct nm_desc *d, const struct nm_desc *parent)
996{
997	if (d->done_mmap)
998		return 0;
999
1000	if (IS_NETMAP_DESC(parent) && parent->mem &&
1001	    parent->req.nr_arg2 == d->req.nr_arg2) {
1002		/* do not mmap, inherit from parent */
1003		D("do not mmap, inherit from parent");
1004		d->memsize = parent->memsize;
1005		d->mem = parent->mem;
1006	} else {
1007		/* XXX TODO: check if memsize is too large (or there is overflow) */
1008		d->memsize = d->req.nr_memsize;
1009		d->mem = mmap(0, d->memsize, PROT_WRITE | PROT_READ, MAP_SHARED,
1010				d->fd, 0);
1011		if (d->mem == MAP_FAILED) {
1012			goto fail;
1013		}
1014		d->done_mmap = 1;
1015	}
1016	{
1017		struct netmap_if *nifp = NETMAP_IF(d->mem, d->req.nr_offset);
1018		struct netmap_ring *r = NETMAP_RXRING(nifp, d->first_rx_ring);
1019		if ((void *)r == (void *)nifp) {
1020			/* the descriptor is open for TX only */
1021			r = NETMAP_TXRING(nifp, d->first_tx_ring);
1022		}
1023
1024		*(struct netmap_if **)(uintptr_t)&(d->nifp) = nifp;
1025		*(struct netmap_ring **)(uintptr_t)&d->some_ring = r;
1026		*(void **)(uintptr_t)&d->buf_start = NETMAP_BUF(r, 0);
1027		*(void **)(uintptr_t)&d->buf_end =
1028			(char *)d->mem + d->memsize;
1029	}
1030
1031	return 0;
1032
1033fail:
1034	return EINVAL;
1035}
1036
1037/*
1038 * Same prototype as pcap_inject(), only need to cast.
1039 */
1040static int
1041nm_inject(struct nm_desc *d, const void *buf, size_t size)
1042{
1043	u_int c, n = d->last_tx_ring - d->first_tx_ring + 1,
1044		ri = d->cur_tx_ring;
1045
1046	for (c = 0; c < n ; c++, ri++) {
1047		/* compute current ring to use */
1048		struct netmap_ring *ring;
1049		uint32_t i, j, idx;
1050		size_t rem;
1051
1052		if (ri > d->last_tx_ring)
1053			ri = d->first_tx_ring;
1054		ring = NETMAP_TXRING(d->nifp, ri);
1055		rem = size;
1056		j = ring->cur;
1057		while (rem > ring->nr_buf_size && j != ring->tail) {
1058			rem -= ring->nr_buf_size;
1059			j = nm_ring_next(ring, j);
1060		}
1061		if (j == ring->tail && rem > 0)
1062			continue;
1063		i = ring->cur;
1064		while (i != j) {
1065			idx = ring->slot[i].buf_idx;
1066			ring->slot[i].len = ring->nr_buf_size;
1067			ring->slot[i].flags = NS_MOREFRAG;
1068			nm_pkt_copy(buf, NETMAP_BUF(ring, idx), ring->nr_buf_size);
1069			i = nm_ring_next(ring, i);
1070			buf = (const char *)buf + ring->nr_buf_size;
1071		}
1072		idx = ring->slot[i].buf_idx;
1073		ring->slot[i].len = rem;
1074		ring->slot[i].flags = 0;
1075		nm_pkt_copy(buf, NETMAP_BUF(ring, idx), rem);
1076		ring->head = ring->cur = nm_ring_next(ring, i);
1077		d->cur_tx_ring = ri;
1078		return size;
1079	}
1080	return 0; /* fail */
1081}
1082
1083
1084/*
1085 * Same prototype as pcap_dispatch(), only need to cast.
1086 */
1087static int
1088nm_dispatch(struct nm_desc *d, int cnt, nm_cb_t cb, u_char *arg)
1089{
1090	int n = d->last_rx_ring - d->first_rx_ring + 1;
1091	int c, got = 0, ri = d->cur_rx_ring;
1092	d->hdr.buf = NULL;
1093	d->hdr.flags = NM_MORE_PKTS;
1094	d->hdr.d = d;
1095
1096	if (cnt == 0)
1097		cnt = -1;
1098	/* cnt == -1 means infinite, but rings have a finite amount
1099	 * of buffers and the int is large enough that we never wrap,
1100	 * so we can omit checking for -1
1101	 */
1102	for (c=0; c < n && cnt != got; c++, ri++) {
1103		/* compute current ring to use */
1104		struct netmap_ring *ring;
1105
1106		if (ri > d->last_rx_ring)
1107			ri = d->first_rx_ring;
1108		ring = NETMAP_RXRING(d->nifp, ri);
1109		for ( ; !nm_ring_empty(ring) && cnt != got; got++) {
1110			u_int idx, i;
1111			u_char *oldbuf;
1112			struct netmap_slot *slot;
1113			if (d->hdr.buf) { /* from previous round */
1114				cb(arg, &d->hdr, d->hdr.buf);
1115			}
1116			i = ring->cur;
1117			slot = &ring->slot[i];
1118			idx = slot->buf_idx;
1119			/* d->cur_rx_ring doesn't change inside this loop, but
1120			 * set it here, so it reflects d->hdr.buf's ring */
1121			d->cur_rx_ring = ri;
1122			d->hdr.slot = slot;
1123			oldbuf = d->hdr.buf = (u_char *)NETMAP_BUF(ring, idx);
1124			// __builtin_prefetch(buf);
1125			d->hdr.len = d->hdr.caplen = slot->len;
1126			while (slot->flags & NS_MOREFRAG) {
1127				u_char *nbuf;
1128				u_int oldlen = slot->len;
1129				i = nm_ring_next(ring, i);
1130				slot = &ring->slot[i];
1131				d->hdr.len += slot->len;
1132				nbuf = (u_char *)NETMAP_BUF(ring, slot->buf_idx);
1133				if (oldbuf != NULL && (uint32_t)(nbuf - oldbuf) == ring->nr_buf_size &&
1134						oldlen == ring->nr_buf_size) {
1135					d->hdr.caplen += slot->len;
1136					oldbuf = nbuf;
1137				} else {
1138					oldbuf = NULL;
1139				}
1140			}
1141			d->hdr.ts = ring->ts;
1142			ring->head = ring->cur = nm_ring_next(ring, i);
1143		}
1144	}
1145	if (d->hdr.buf) { /* from previous round */
1146		d->hdr.flags = 0;
1147		cb(arg, &d->hdr, d->hdr.buf);
1148	}
1149	return got;
1150}
1151
1152static u_char *
1153nm_nextpkt(struct nm_desc *d, struct nm_pkthdr *hdr)
1154{
1155	int ri = d->cur_rx_ring;
1156
1157	do {
1158		/* compute current ring to use */
1159		struct netmap_ring *ring = NETMAP_RXRING(d->nifp, ri);
1160		if (!nm_ring_empty(ring)) {
1161			u_int i = ring->cur;
1162			u_int idx = ring->slot[i].buf_idx;
1163			u_char *buf = (u_char *)NETMAP_BUF(ring, idx);
1164
1165			// __builtin_prefetch(buf);
1166			hdr->ts = ring->ts;
1167			hdr->len = hdr->caplen = ring->slot[i].len;
1168			ring->cur = nm_ring_next(ring, i);
1169			/* we could postpone advancing head if we want
1170			 * to hold the buffer. This can be supported in
1171			 * the future.
1172			 */
1173			ring->head = ring->cur;
1174			d->cur_rx_ring = ri;
1175			return buf;
1176		}
1177		ri++;
1178		if (ri > d->last_rx_ring)
1179			ri = d->first_rx_ring;
1180	} while (ri != d->cur_rx_ring);
1181	return NULL; /* nothing found */
1182}
1183
1184#endif /* !HAVE_NETMAP_WITH_LIBS */
1185
1186#endif /* NETMAP_WITH_LIBS */
1187
1188#endif /* _NET_NETMAP_USER_H_ */
1189