Sync netmap sources with the version in our private tree.

This commit contains large contributions from Giuseppe Lettieri and
Stefano Garzarella, is partly supported by grants from Verisign and Cisco,
and brings in the following:

- fix zerocopy monitor ports and introduce copying monitor ports
  (the latter are lower performance but give access to all traffic
  in parallel with the application)

- exclusive open mode, useful to implement solutions that recover
  from crashes of the main netmap client (suggested by Patrick Kelsey)

- revised memory allocator in preparation for the 'passthrough mode'
  (ptnetmap) recently presented at bsdcan. ptnetmap is described in
        S. Garzarella, G. Lettieri, L. Rizzo;
        Virtual device passthrough for high speed VM networking,
        ACM/IEEE ANCS 2015, Oakland (CA) May 2015
        http://info.iet.unipi.it/~luigi/research.html

- fix rx CRC handing on ixl

- add module dependencies for netmap when building drivers as modules

- minor simplifications to device-specific routines (*txsync, *rxsync)

- general code cleanup (remove unused variables, introduce macros
  to access rings and remove duplicate code,

Applications do not need to be recompiled, unless of course
they want to use the new features (monitors and exclusive open).

Those willing to try this code on stable/10 can just update the
sys/dev/netmap/*, sys/net/netmap* with the version in HEAD
and apply the small patches to individual device drivers.

MFC after:	1 month
Sponsored by:	(partly) Verisign, Cisco

1 files changed, 109 insertions, 46 deletions

diff --git a/sys/net/netmap_user.h b/sys/net/netmap_user.h
index aab6c35..130117d 100644
--- a/sys/net/netmap_user.h
+++ b/sys/net/netmap_user.h
@@ -284,6 +284,12 @@ typedef void (*nm_cb_t)(u_char *, const struct nm_pkthdr *, const u_char *d);
  *		-NN		bind individual NIC ring pair
  *		{NN		bind master side of pipe NN
  *		}NN		bind slave side of pipe NN
+ *		a suffix starting with + and the following flags,
+ *		in any order:
+ *		x		exclusive access
+ *		z		zero copy monitor
+ *		t		monitor tx side
+ *		r		monitor rx side
  *
  * req		provides the initial values of nmreq before parsing ifname.
  *		Remember that the ifname parsing will override the ring
@@ -351,9 +357,12 @@ nm_open(const char *ifname, const struct nmreq *req,
 	struct nm_desc *d = NULL;
 	const struct nm_desc *parent = arg;
 	u_int namelen;
-	uint32_t nr_ringid = 0, nr_flags;
+	uint32_t nr_ringid = 0, nr_flags, nr_reg;
 	const char *port = NULL;
-	const char *errmsg = NULL;
+#define MAXERRMSG 80
+	char errmsg[MAXERRMSG] = "";
+	enum { P_START, P_RNGSFXOK, P_GETNUM, P_FLAGS, P_FLAGSOK } p_state;
+	long num;
 
 	if (strncmp(ifname, "netmap:", 7) && strncmp(ifname, "vale", 4)) {
 		errno = 0; /* name not recognised, not an error */
@@ -362,60 +371,112 @@ nm_open(const char *ifname, const struct nmreq *req,
 	if (ifname[0] == 'n')
 		ifname += 7;
 	/* scan for a separator */
-	for (port = ifname; *port && !index("-*^{}", *port); port++)
+	for (port = ifname; *port && !index("-*^{}/", *port); port++)
 		;
 	namelen = port - ifname;
 	if (namelen >= sizeof(d->req.nr_name)) {
-		errmsg = "name too long";
+		snprintf(errmsg, MAXERRMSG, "name too long");
 		goto fail;
 	}
-	switch (*port) {
-	default:  /* '\0', no suffix */
-		nr_flags = NR_REG_ALL_NIC;
-		break;
-	case '-': /* one NIC */
-		nr_flags = NR_REG_ONE_NIC;
-		nr_ringid = atoi(port + 1);
-		break;
-	case '*': /* NIC and SW, ignore port */
-		nr_flags = NR_REG_NIC_SW;
-		if (port[1]) {
-			errmsg = "invalid port for nic+sw";
-			goto fail;
-		}
-		break;
-	case '^': /* only sw ring */
-		nr_flags = NR_REG_SW;
-		if (port[1]) {
-			errmsg = "invalid port for sw ring";
-			goto fail;
+	p_state = P_START;
+	nr_flags = NR_REG_ALL_NIC; /* default for no suffix */
+	while (*port) {
+		switch (p_state) {
+		case P_START:
+			switch (*port) {
+			case '^': /* only SW ring */
+				nr_flags = NR_REG_SW;
+				p_state = P_RNGSFXOK;
+				break;
+			case '*': /* NIC and SW */
+				nr_flags = NR_REG_NIC_SW;
+				p_state = P_RNGSFXOK;
+				break;
+			case '-': /* one NIC ring pair */
+				nr_flags = NR_REG_ONE_NIC;
+				p_state = P_GETNUM;
+				break;
+			case '{': /* pipe (master endpoint) */
+				nr_flags = NR_REG_PIPE_MASTER;
+				p_state = P_GETNUM;
+				break;
+			case '}': /* pipe (slave endoint) */
+				nr_flags = NR_REG_PIPE_SLAVE;
+				p_state = P_GETNUM;
+				break;
+			case '/': /* start of flags */
+				p_state = P_FLAGS;
+				break;
+			default:
+				snprintf(errmsg, MAXERRMSG, "unknown modifier: '%c'", *port);
+				goto fail;
+			}
+			port++;
+			break;
+		case P_RNGSFXOK:
+			switch (*port) {
+			case '/':
+				p_state = P_FLAGS;
+				break;
+			default:
+				snprintf(errmsg, MAXERRMSG, "unexpected character: '%c'", *port);
+				goto fail;
+			}
+			port++;
+			break;
+		case P_GETNUM:
+			num = strtol(port, (char **)&port, 10);
+			if (num < 0 || num >= NETMAP_RING_MASK) {
+				snprintf(errmsg, MAXERRMSG, "'%ld' out of range [0, %d)",
+						num, NETMAP_RING_MASK);
+				goto fail;
+			}
+			nr_ringid = num & NETMAP_RING_MASK;
+			p_state = P_RNGSFXOK;
+			break;
+		case P_FLAGS:
+		case P_FLAGSOK:
+			switch (*port) {
+			case 'x':
+				nr_flags |= NR_EXCLUSIVE;
+				break;
+			case 'z':
+				nr_flags |= NR_ZCOPY_MON;
+				break;
+			case 't':
+				nr_flags |= NR_MONITOR_TX;
+				break;
+			case 'r':
+				nr_flags |= NR_MONITOR_RX;
+				break;
+			default:
+				snprintf(errmsg, MAXERRMSG, "unrecognized flag: '%c'", *port);
+				goto fail;
+			}
+			port++;
+			p_state = P_FLAGSOK;
+			break;
 		}
-		break;
-	case '{':
-		nr_flags = NR_REG_PIPE_MASTER;
-		nr_ringid = atoi(port + 1);
-		break;
-	case '}':
-		nr_flags = NR_REG_PIPE_SLAVE;
-		nr_ringid = atoi(port + 1);
-		break;
 	}
-
-	if (nr_ringid >= NETMAP_RING_MASK) {
-		errmsg = "invalid ringid";
+	if (p_state != P_START && p_state != P_RNGSFXOK && p_state != P_FLAGSOK) {
+		snprintf(errmsg, MAXERRMSG, "unexpected end of port name");
 		goto fail;
 	}
-
+	ND("flags: %s %s %s %s",
+			(nr_flags & NR_EXCLUSIVE) ? "EXCLUSIVE" : "",
+			(nr_flags & NR_ZCOPY_MON) ? "ZCOPY_MON" : "",
+			(nr_flags & NR_MONITOR_TX) ? "MONITOR_TX" : "",
+			(nr_flags & NR_MONITOR_RX) ? "MONITOR_RX" : "");
 	d = (struct nm_desc *)calloc(1, sizeof(*d));
 	if (d == NULL) {
-		errmsg = "nm_desc alloc failure";
+		snprintf(errmsg, MAXERRMSG, "nm_desc alloc failure");
 		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) {
-		errmsg = "cannot open /dev/netmap";
+		snprintf(errmsg, MAXERRMSG, "cannot open /dev/netmap: %s", strerror(errno));
 		goto fail;
 	}
 
@@ -464,7 +525,7 @@ nm_open(const char *ifname, const struct nmreq *req,
 	d->req.nr_ringid |= new_flags & (NETMAP_NO_TX_POLL | NETMAP_DO_RX_POLL);
 
 	if (ioctl(d->fd, NIOCREGIF, &d->req)) {
-		errmsg = "NIOCREGIF failed";
+		snprintf(errmsg, MAXERRMSG, "NIOCREGIF failed: %s", strerror(errno));
 		goto fail;
 	}
 
@@ -479,7 +540,7 @@ nm_open(const char *ifname, const struct nmreq *req,
 		d->mem = mmap(0, d->memsize, PROT_WRITE | PROT_READ, MAP_SHARED,
 				d->fd, 0);
 		if (d->mem == MAP_FAILED) {
-			errmsg = "mmap failed";
+			snprintf(errmsg, MAXERRMSG, "mmap failed: %s", strerror(errno));
 			goto fail;
 		}
 		d->done_mmap = 1;
@@ -495,20 +556,22 @@ nm_open(const char *ifname, const struct nmreq *req,
 			(char *)d->mem + d->memsize;
 	}
 
-	if (d->req.nr_flags ==  NR_REG_SW) { /* host stack */
+	nr_reg = d->req.nr_flags & NR_REG_MASK;
+
+	if (nr_reg ==  NR_REG_SW) { /* host stack */
 		d->first_tx_ring = d->last_tx_ring = d->req.nr_tx_rings;
 		d->first_rx_ring = d->last_rx_ring = d->req.nr_rx_rings;
-	} else if (d->req.nr_flags ==  NR_REG_ALL_NIC) { /* only nic */
+	} else if (nr_reg ==  NR_REG_ALL_NIC) { /* only nic */
 		d->first_tx_ring = 0;
 		d->first_rx_ring = 0;
 		d->last_tx_ring = d->req.nr_tx_rings - 1;
 		d->last_rx_ring = d->req.nr_rx_rings - 1;
-	} else if (d->req.nr_flags ==  NR_REG_NIC_SW) {
+	} else if (nr_reg ==  NR_REG_NIC_SW) {
 		d->first_tx_ring = 0;
 		d->first_rx_ring = 0;
 		d->last_tx_ring = d->req.nr_tx_rings;
 		d->last_rx_ring = d->req.nr_rx_rings;
-	} else if (d->req.nr_flags == NR_REG_ONE_NIC) {
+	} else if (nr_reg == NR_REG_ONE_NIC) {
 		/* XXX check validity */
 		d->first_tx_ring = d->last_tx_ring =
 		d->first_rx_ring = d->last_rx_ring = d->req.nr_ringid & NETMAP_RING_MASK;
@@ -541,7 +604,7 @@ nm_open(const char *ifname, const struct nmreq *req,
 
 fail:
 	nm_close(d);
-	if (errmsg)
+	if (errmsg[0])
 		D("%s %s", errmsg, ifname);
 	if (errno == 0)
 		errno = EINVAL;