Import the current version of netmap, aligned with the one on github.

This commit, long overdue, contains contributions in the last 2 years
from Stefano Garzarella, Giuseppe Lettieri, Vincenzo Maffione, including:
+ fixes on monitor ports
+ the 'ptnet' virtual device driver, and ptnetmap backend, for
  high speed virtual passthrough on VMs (bhyve fixes in an upcoming commit)
+ improved emulated netmap mode
+ more robust error handling
+ removal of stale code
+ various fixes to code and documentation (some mixup between RX and TX
  parameters, and private and public variables)

We also include an additional tool, nmreplay, which is functionally
equivalent to tcpreplay but operating on netmap ports.

share/man/man4/netmap.4

@@ -33,48 +33,71 @@
 .Sh NAME
 .Nm netmap
 .Nd a framework for fast packet I/O
-.Pp
+.br
 .Nm VALE
 .Nd a fast VirtuAl Local Ethernet using the netmap API
-.Pp
+.br
 .Nm netmap pipes
 .Nd a shared memory packet transport channel
 .Sh SYNOPSIS
 .Cd device netmap
 .Sh DESCRIPTION
 .Nm
 is a framework for extremely fast and efficient packet I/O
-for both userspace and kernel clients.
+for userspace and kernel clients, and for Virtual Machines.
 It runs on
 .Fx
-and Linux, and includes
-.Nm VALE ,
-a very fast and modular in-kernel software switch/dataplane,
-and
-.Nm netmap pipes ,
-a shared memory packet transport channel.
-All these are accessed interchangeably with the same API.
+Linux and some versions of Windows, and supports a variety of
+.Nm netmap ports ,
+including
+.Bl -tag -width XXXX
+.It Nm physical NIC ports
+to access individual queues of network interfaces;
+.It Nm host ports
+to inject packets into the host stack;
+.It Nm VALE ports
+implementing a very fast and modular in-kernel software switch/dataplane;
+.It Nm netmap pipes
+a shared memory packet transport channel;
+.It Nm netmap monitors
+a mechanism similar to
+.Xr bpf
+to capture traffic
+.El
 .Pp
-.Nm ,
-.Nm VALE
-and
-.Nm netmap pipes
-are at least one order of magnitude faster than
+All these
+.Nm netmap ports
+are accessed interchangeably with the same API,
+and are at least one order of magnitude faster than
 standard OS mechanisms
-(sockets, bpf, tun/tap interfaces, native switches, pipes),
-reaching 14.88 million packets per second (Mpps)
-with much less than one core on a 10 Gbit NIC,
-about 20 Mpps per core for VALE ports,
-and over 100 Mpps for netmap pipes.
+(sockets, bpf, tun/tap interfaces, native switches, pipes).
+With suitably fast hardware (NICs, PCIe buses, CPUs),
+packet I/O using
+.Nm
+on supported NICs
+reaches 14.88 million packets per second (Mpps)
+with much less than one core on 10 Gbit/s NICs;
+35-40 Mpps on 40 Gbit/s NICs (limited by the hardware);
+about 20 Mpps per core for VALE ports;
+and over 100 Mpps for
+.Nm netmap pipes.
+NICs without native
+.Nm
+support can still use the API in emulated mode,
+which uses unmodified device drivers and is 3-5 times faster than
+.Xr bpf
+or raw sockets.
 .Pp
 Userspace clients can dynamically switch NICs into
 .Nm
 mode and send and receive raw packets through
 memory mapped buffers.
 Similarly,
 .Nm VALE
-switch instances and ports, and
+switch instances and ports,
 .Nm netmap pipes
+and
+.Nm netmap monitors
 can be created dynamically,
 providing high speed packet I/O between processes,
 virtual machines, NICs and the host stack.
@@ -89,17 +112,17 @@ and standard OS mechanisms such as
 .Xr epoll 2 ,
 and
 .Xr kqueue 2 .
-.Nm VALE
-and
-.Nm netmap pipes
+All types of
+.Nm netmap ports
+and the
+.Nm VALE switch
 are implemented by a single kernel module, which also emulates the
 .Nm
-API over standard drivers for devices without native
-.Nm
-support.
+API over standard drivers.
 For best performance,
 .Nm
-requires explicit support in device drivers.
+requires native support in device drivers.
+A list of such devices is at the end of this document.
 .Pp
 In the rest of this (long) manual page we document
 various aspects of the
@@ -116,7 +139,7 @@ which can be connected to a physical interface
 to the host stack,
 or to a
 .Nm VALE
-switch).
+switch.
 Ports use preallocated circular queues of buffers
 .Em ( rings )
 residing in an mmapped region.
@@ -166,16 +189,18 @@ has multiple modes of operation controlled by the
 .Vt struct nmreq
 argument.
 .Va arg.nr_name
-specifies the port name, as follows:
+specifies the netmap port name, as follows:
 .Bl -tag -width XXXX
 .It Dv OS network interface name (e.g. 'em0', 'eth1', ... )
 the data path of the NIC is disconnected from the host stack,
 and the file descriptor is bound to the NIC (one or all queues),
 or to the host stack;
-.It Dv valeXXX:YYY (arbitrary XXX and YYY)
-the file descriptor is bound to port YYY of a VALE switch called XXX,
-both dynamically created if necessary.
-The string cannot exceed IFNAMSIZ characters, and YYY cannot
+.It Dv valeSSS:PPP
+the file descriptor is bound to port PPP of VALE switch SSS.
+Switch instances and ports are dynamically created if necessary.
+.br
+Both SSS and PPP have the form [0-9a-zA-Z_]+ , the string
+cannot exceed IFNAMSIZ characters, and PPP cannot
 be the name of any existing OS network interface.
 .El
 .Pp
@@ -312,9 +337,6 @@ one slot is always kept empty.
 The ring size
 .Va ( num_slots )
 should not be assumed to be a power of two.
-.br
-(NOTE: older versions of netmap used head/count format to indicate
-the content of a ring).
 .Pp
 .Va head
 is the first slot available to userspace;
@@ -585,6 +607,15 @@ it from the host stack.
 Multiple file descriptors can be bound to the same port,
 with proper synchronization left to the user.
 .Pp
+The recommended way to bind a file descriptor to a port is
+to use function
+.Va nm_open(..)
+(see
+.Xr LIBRARIES )
+which parses names to access specific port types and
+enable features.
+In the following we document the main features.
+.Pp
 .Dv NIOCREGIF can also bind a file descriptor to one endpoint of a
 .Em netmap pipe ,
 consisting of two netmap ports with a crossover connection.
@@ -734,7 +765,7 @@ similar to
 binds a file descriptor to a port.
 .Bl -tag -width XX
 .It Va ifname
-is a port name, in the form "netmap:XXX" for a NIC and "valeXXX:YYY" for a
+is a port name, in the form "netmap:PPP" for a NIC and "valeSSS:PPP" for a
 .Nm VALE
 port.
 .It Va req
@@ -774,28 +805,39 @@ similar to pcap_next(), fetches the next packet
 natively supports the following devices:
 .Pp
 On FreeBSD:
+.Xr cxgbe 4 ,
 .Xr em 4 ,
 .Xr igb 4 ,
 .Xr ixgbe 4 ,
+.Xr ixl 4 ,
 .Xr lem 4 ,
 .Xr re 4 .
 .Pp
 On Linux
 .Xr e1000 4 ,
 .Xr e1000e 4 ,
+.Xr i40e 4 ,
 .Xr igb 4 ,
 .Xr ixgbe 4 ,
-.Xr mlx4 4 ,
-.Xr forcedeth 4 ,
 .Xr r8169 4 .
 .Pp
 NICs without native support can still be used in
 .Nm
 mode through emulation.
 Performance is inferior to native netmap
-mode but still significantly higher than sockets, and approaching
+mode but still significantly higher than various raw socket types
+(bpf, PF_PACKET, etc.).
+Note that for slow devices (such as 1 Gbit/s and slower NICs,
+or several 10 Gbit/s NICs whose hardware is unable 
 that of in-kernel solutions such as Linux's
 .Xr pktgen .
+When emulation is in use, packet sniffer programs such as tcpdump
+could see received packets before they are diverted by netmap. This behaviour
+is not intentional, being just an artifact of the implementation of emulation.
+Note that in case the netmap application subsequently moves packets received
+from the emulated adapter onto the host RX ring, the sniffer will intercept
+those packets again, since the packets are injected to the host stack as they
+were received by the network interface.
 .Pp
 Emulation is also available for devices with native netmap support,
 which can be used for testing or performance comparison.
@@ -812,8 +854,12 @@ and module parameters on Linux
 .Bl -tag -width indent
 .It Va dev.netmap.admode: 0
 Controls the use of native or emulated adapter mode.
-0 uses the best available option, 1 forces native and
-fails if not available, 2 forces emulated hence never fails.
+.br
+0 uses the best available option;
+.br
+1 forces native mode and fails if not available;
+.br
+2 forces emulated hence never fails.
 .It Va dev.netmap.generic_ringsize: 1024
 Ring size used for emulated netmap mode
 .It Va dev.netmap.generic_mit: 100000
@@ -861,9 +907,9 @@ performance.
 uses
 .Xr select 2 ,
 .Xr poll 2 ,
-.Xr epoll
+.Xr epoll 2
 and
-.Xr kqueue
+.Xr kqueue 2
 to wake up processes when significant events occur, and
 .Xr mmap 2
 to map memory.
@@ -1015,8 +1061,8 @@ e.g. running the following in two different terminals:
 .Dl pkt-gen -i vale1:b -f tx # sender
 The same example can be used to test netmap pipes, by simply
 changing port names, e.g.
-.Dl pkt-gen -i vale:x{3 -f rx # receiver on the master side
-.Dl pkt-gen -i vale:x}3 -f tx # sender on the slave side
+.Dl pkt-gen -i vale2:x{3 -f rx # receiver on the master side
+.Dl pkt-gen -i vale2:x}3 -f tx # sender on the slave side
 .Pp
 The following command attaches an interface and the host stack
 to a switch:

sys/conf/files

@@ -2187,6 +2187,7 @@ dev/nand/nfc_if.m		optional nand
 dev/ncr/ncr.c			optional ncr pci
 dev/ncv/ncr53c500.c		optional ncv
 dev/ncv/ncr53c500_pccard.c	optional ncv pccard
+dev/netmap/if_ptnet.c		optional netmap
 dev/netmap/netmap.c		optional netmap
 dev/netmap/netmap_freebsd.c	optional netmap
 dev/netmap/netmap_generic.c	optional netmap
@@ -2195,6 +2196,7 @@ dev/netmap/netmap_mem2.c	optional netmap
 dev/netmap/netmap_monitor.c	optional netmap
 dev/netmap/netmap_offloadings.c	optional netmap
 dev/netmap/netmap_pipe.c	optional netmap
+dev/netmap/netmap_pt.c		optional netmap
 dev/netmap/netmap_vale.c	optional netmap
 # compile-with "${NORMAL_C} -Wconversion -Wextra"
 dev/nfsmb/nfsmb.c		optional nfsmb pci

sys/dev/netmap/if_ixl_netmap.h

@@ -59,7 +59,7 @@ extern int ixl_rx_miss, ixl_rx_miss_bufs, ixl_crcstrip;
 /*
  * device-specific sysctl variables:
  *
- * ixl_crcstrip: 0: keep CRC in rx frames (default), 1: strip it.
+ * ixl_crcstrip: 0: NIC keeps CRC in rx frames, 1: NIC strips it (default).
  *	During regular operations the CRC is stripped, but on some
  *	hardware reception of frames not multiple of 64 is slower,
  *	so using crcstrip=0 helps in benchmarks.
@@ -73,7 +73,7 @@ SYSCTL_DECL(_dev_netmap);
  */
 #if 0
 SYSCTL_INT(_dev_netmap, OID_AUTO, ixl_crcstrip,
-    CTLFLAG_RW, &ixl_crcstrip, 1, "strip CRC on rx frames");
+    CTLFLAG_RW, &ixl_crcstrip, 1, "NIC strips CRC on rx frames");
 #endif
 SYSCTL_INT(_dev_netmap, OID_AUTO, ixl_rx_miss,
     CTLFLAG_RW, &ixl_rx_miss, 0, "potentially missed rx intr");