1 files changed, 257 insertions, 23 deletions

diff --git a/sys/net/netmap_user.h b/sys/net/netmap_user.h
index fcb5cb3ea1c1..3f2858304caf 100644
--- a/sys/net/netmap_user.h
+++ b/sys/net/netmap_user.h
@@ -1,33 +1,28 @@
 /*
  * Copyright (C) 2011 Matteo Landi, Luigi Rizzo. All rights reserved.
- * 
+ * Copyright (C) 2013 Universita` di Pisa
+ *
  * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- * 
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
  *   1. Redistributions of source code must retain the above copyright
  *      notice, this list of conditions and the following disclaimer.
- * 
  *   2. Redistributions in binary form must reproduce the above copyright
  *      notice, this list of conditions and the following disclaimer in the
- *      documentation and/or other materials provided with the
- *      distribution.
- * 
- *   3. Neither the name of the authors nor the names of their contributors
- *      may be used to endorse or promote products derived from this
- *      software without specific prior written permission.
- * 
- * THIS SOFTWARE IS PROVIDED BY MATTEO LANDI AND CONTRIBUTORS "AS IS" AND
+ *      documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTEO LANDI OR CONTRIBUTORS
- * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
- * THE POSSIBILITY OF SUCH DAMAGE.
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
  */
 
 /*
@@ -56,11 +51,22 @@
  *
  * Since rings are circular, we have macros to compute the next index
  *	i = NETMAP_RING_NEXT(ring, i);
+ *
+ * To ease porting apps from pcap to netmap we supply a few fuctions
+ * that can be called to open, close and read from netmap in a way
+ * similar to libpcap.
+ *
+ * In order to use these, include #define NETMAP_WITH_LIBS
+ * in the source file that invokes these functions.
  */
 
 #ifndef _NET_NETMAP_USER_H_
 #define _NET_NETMAP_USER_H_
 
+#include <stdint.h>
+#include <net/if.h>		/* IFNAMSIZ */
+#include <net/netmap.h>
+
 #define _NETMAP_OFFSET(type, ptr, offset) \
 	((type)(void *)((char *)(ptr) + (offset)))
 
@@ -77,7 +83,7 @@
 
 #define NETMAP_BUF_IDX(ring, buf)			\
 	( ((char *)(buf) - ((char *)(ring) + (ring)->buf_ofs) ) / \
-		(ring)->nr_buf_size ) 
+		(ring)->nr_buf_size )
 
 #define	NETMAP_RING_NEXT(r, i)				\
 	((i)+1 == (r)->num_slots ? 0 : (i) + 1 )
@@ -92,4 +98,232 @@
  */
 #define NETMAP_TX_RING_EMPTY(r)	((r)->avail >= (r)->num_slots - 1)
 
+#ifdef NETMAP_WITH_LIBS
+/*
+ * Support for simple I/O libraries.
+ * Include other system headers required for compiling this.
+ */
+
+#ifndef HAVE_NETMAP_WITH_LIBS
+#define HAVE_NETMAP_WITH_LIBS
+
+#include <sys/time.h>
+#include <sys/mman.h>
+#include <string.h>	/* memset */
+#include <sys/ioctl.h>
+#include <sys/errno.h>	/* EINVAL */
+#include <fcntl.h>	/* O_RDWR */
+#include <malloc.h>
+
+struct nm_hdr_t {	/* same as pcap_pkthdr */
+	struct timeval	ts;
+	uint32_t	caplen;
+	uint32_t	len;
+};
+
+struct nm_desc_t {
+	struct nm_desc_t *self;
+	int fd;
+	void *mem;
+	int memsize;
+	struct netmap_if *nifp;
+	uint16_t first_ring, last_ring, cur_ring;
+	struct nmreq req;
+	struct nm_hdr_t hdr;
+};
+
+/*
+ * when the descriptor is open correctly, d->self == d
+ */
+#define P2NMD(p)		((struct nm_desc_t *)(p))
+#define IS_NETMAP_DESC(d)	(P2NMD(d)->self == P2NMD(d))
+#define NETMAP_FD(d)		(P2NMD(d)->fd)
+
+/*
+ * The callback, invoked on each received packet. Same as libpcap
+ */
+typedef void (*nm_cb_t)(u_char *, const struct nm_hdr_t *, const u_char *d);
+
+/*
+ * The open routine accepts an ifname (netmap:foo or vale:foo) and
+ * optionally a second (string) argument indicating the ring number
+ * to open. If successful, t opens the fd and maps the memory.
+ */
+static struct nm_desc_t *nm_open(const char *ifname,
+	 const char *ring_no, int flags, int ring_flags);
+
+/*
+ * nm_dispatch() is the same as pcap_dispatch()
+ * nm_next() is the same as pcap_next()
+ */
+static int nm_dispatch(struct nm_desc_t *, int, nm_cb_t, u_char *);
+static u_char *nm_next(struct nm_desc_t *, struct nm_hdr_t *);
+
+/*
+ * unmap memory, close file descriptor and free the descriptor.
+ */
+static int nm_close(struct nm_desc_t *);
+
+
+/*
+ * Try to open, return descriptor if successful, NULL otherwise.
+ * An invalid netmap name will return errno = 0;
+ */
+static struct nm_desc_t *
+nm_open(const char *ifname, const char *ring_name, int flags, int ring_flags)
+{
+	struct nm_desc_t *d;
+	u_int n;
+
+	if (strncmp(ifname, "netmap:", 7) && strncmp(ifname, "vale", 4)) {
+		errno = 0; /* name not recognised */
+		return NULL;
+	}
+	if (ifname[0] == 'n')
+		ifname += 7;
+	d = (struct nm_desc_t *)calloc(1, sizeof(*d));
+	if (d == NULL) {
+		errno = ENOMEM;
+		return NULL;
+	}
+	d->self = d;	/* set this early so nm_close() works */
+	d->fd = open("/dev/netmap", O_RDWR);
+	if (d->fd < 0)
+		goto fail;
+
+	if (flags & NETMAP_SW_RING) {
+		d->req.nr_ringid = NETMAP_SW_RING;
+	} else {
+		u_int r;
+		if (flags & NETMAP_HW_RING) /* interpret ring as int */
+			r = (uintptr_t)ring_name;
+		else /* interpret ring as numeric string */
+			r = ring_name ? atoi(ring_name) : ~0;
+		r = (r < NETMAP_RING_MASK) ? (r | NETMAP_HW_RING) : 0;
+		d->req.nr_ringid = r; /* set the ring */
+	}
+	d->req.nr_ringid |= (flags & ~NETMAP_RING_MASK);
+	d->req.nr_version = NETMAP_API;
+	strncpy(d->req.nr_name, ifname, sizeof(d->req.nr_name));
+	if (ioctl(d->fd, NIOCREGIF, &d->req))
+		goto fail;
+
+	d->memsize = d->req.nr_memsize;
+	d->mem = mmap(0, d->memsize, PROT_WRITE | PROT_READ, MAP_SHARED,
+			d->fd, 0);
+	if (d->mem == NULL)
+		goto fail;
+	d->nifp = NETMAP_IF(d->mem, d->req.nr_offset);
+	if (d->req.nr_ringid & NETMAP_SW_RING) {
+		d->first_ring = d->last_ring = d->req.nr_rx_rings;
+	} else if (d->req.nr_ringid & NETMAP_HW_RING) {
+		d->first_ring = d->last_ring =
+			d->req.nr_ringid & NETMAP_RING_MASK;
+	} else {
+		d->first_ring = 0;
+		d->last_ring = d->req.nr_rx_rings - 1;
+	}
+	d->cur_ring = d->first_ring;
+	for (n = d->first_ring; n <= d->last_ring; n++) {
+		struct netmap_ring *ring = NETMAP_RXRING(d->nifp, n);
+		ring->flags |= ring_flags;
+	}
+	return d;
+
+fail:
+	nm_close(d);
+	errno = EINVAL;
+	return NULL;
+}
+
+
+static int
+nm_close(struct nm_desc_t *d)
+{
+	if (d == NULL || d->self != d)
+		return EINVAL;
+	if (d->mem)
+		munmap(d->mem, d->memsize);
+	if (d->fd != -1)
+		close(d->fd);
+	bzero(d, sizeof(*d));
+	free(d);
+	return 0;
+}
+
+
+/*
+ * Same prototype as pcap_dispatch(), only need to cast.
+ */
+inline /* not really, but disable unused warnings */
+static int
+nm_dispatch(struct nm_desc_t *d, int cnt, nm_cb_t cb, u_char *arg)
+{
+	int n = d->last_ring - d->first_ring + 1;
+	int c, got = 0, ri = d->cur_ring;
+
+	if (cnt == 0)
+		cnt = -1;
+	/* cnt == -1 means infinite, but rings have a finite amount
+	 * of buffers and the int is large enough that we never wrap,
+	 * so we can omit checking for -1
+	 */
+	for (c=0; c < n && cnt != got; c++) {
+		/* compute current ring to use */
+		struct netmap_ring *ring;
+
+		ri = d->cur_ring + c;
+		if (ri > d->last_ring)
+			ri = d->first_ring;
+		ring = NETMAP_RXRING(d->nifp, ri);
+		for ( ; ring->avail > 0 && cnt != got; got++) {
+			u_int i = ring->cur;
+			u_int idx = ring->slot[i].buf_idx;
+			u_char *buf = (u_char *)NETMAP_BUF(ring, idx);
+			// XXX should check valid buf
+			// prefetch(buf);
+			d->hdr.len = d->hdr.caplen = ring->slot[i].len;
+			d->hdr.ts = ring->ts;
+			cb(arg, &d->hdr, buf);
+			ring->cur = NETMAP_RING_NEXT(ring, i);
+			ring->avail--;
+		}
+	}
+	d->cur_ring = ri;
+	return got;
+}
+
+inline /* not really, but disable unused warnings */
+static u_char *
+nm_next(struct nm_desc_t *d, struct nm_hdr_t *hdr)
+{
+	int ri = d->cur_ring;
+
+	do {
+		/* compute current ring to use */
+		struct netmap_ring *ring = NETMAP_RXRING(d->nifp, ri);
+		if (ring->avail > 0) {
+			u_int i = ring->cur;
+			u_int idx = ring->slot[i].buf_idx;
+			u_char *buf = (u_char *)NETMAP_BUF(ring, idx);
+			// XXX should check valid buf
+			// prefetch(buf);
+			hdr->ts = ring->ts;
+			hdr->len = hdr->caplen = ring->slot[i].len;
+			ring->cur = NETMAP_RING_NEXT(ring, i);
+			ring->avail--;
+			d->cur_ring = ri;
+			return buf;
+		}
+		ri++;
+		if (ri > d->last_ring)
+			ri = d->first_ring;
+	} while (ri != d->cur_ring);
+	return NULL; /* nothing found */
+}
+
+#endif /* !HAVE_NETMAP_WITH_LIBS */
+
+#endif /* NETMAP_WITH_LIBS */
+
 #endif /* _NET_NETMAP_USER_H_ */