diff options
Diffstat (limited to 'share/man/man4/netmap.4')
| -rw-r--r-- | share/man/man4/netmap.4 | 31 |
1 files changed, 18 insertions, 13 deletions
diff --git a/share/man/man4/netmap.4 b/share/man/man4/netmap.4 index 1ad574d..8edcb02 100644 --- a/share/man/man4/netmap.4 +++ b/share/man/man4/netmap.4 @@ -21,14 +21,14 @@ .\" 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. -.\" +.\" .\" This document is derived in part from the enet man page (enet.4) .\" distributed with 4.3BSD Unix. .\" .\" $FreeBSD$ .\" $Id: netmap.4 9662 2011-11-16 13:18:06Z luigi $: stable/8/share/man/man4/bpf.4 181694 2008-08-13 17:45:06Z ed $ .\" -.Dd November 16, 2011 +.Dd February 27, 2012 .Dt NETMAP 4 .Os .Sh NAME @@ -43,7 +43,7 @@ is a framework for fast and safe access to network devices .Nm uses memory mapped buffers and metadata (buffer indexes and lengths) to communicate with the kernel, -which is in charge of validating information through +which is in charge of validating information through .Pa ioctl() and .Pa select()/poll(). @@ -51,7 +51,6 @@ and can exploit the parallelism in multiqueue devices and multicore systems. .Pp -.Pp .Nm requires explicit support in device drivers. For a list of supported devices, see the end of this manual page. @@ -66,7 +65,7 @@ to bind the file descriptor to a network device. When a device is put in .Nm mode, its data path is disconnected from the host stack. -The processes owning the file descriptor +The processes owning the file descriptor can exchange packets with the device, or with the host stack, through an mmapped memory region that contains pre-allocated buffers and metadata. @@ -89,7 +88,6 @@ are relative (offsets or indexes). Some macros help converting them into actual pointers. .Pp The data structures in shared memory are the following: -.Pp .Bl -tag -width XXX .It Dv struct netmap_if (one per interface) indicates the number of rings supported by an interface, their @@ -123,8 +121,9 @@ one ring pair (numbered N) for packets from/to the host stack. struct netmap_ring { const ssize_t buf_ofs; const uint32_t num_slots; /* number of slots in the ring. */ - uint32_t avail; /* number of usable slots */ - uint32_t cur; /* 'current' index for the user side */ + uint32_t avail; /* number of usable slots */ + uint32_t cur; /* 'current' index for the user side */ + uint32_t reserved; /* not refilled before current */ const uint16_t nr_buf_size; uint16_t flags; @@ -161,7 +160,6 @@ int i = txring->slot[txring->cur].buf_idx; char *buf = NETMAP_BUF(txring, i); .Ed .Ss IOCTLS -.Pp .Nm supports some ioctl() to synchronize the state of the rings between the kernel and the user processes, plus some @@ -173,10 +171,14 @@ defined as follows: .Bd -literal struct nmreq { char nr_name[IFNAMSIZ]; + uint32_t nr_version; /* API version */ +#define NETMAP_API 2 /* current version */ uint32_t nr_offset; /* nifp offset in the shared region */ uint32_t nr_memsize; /* size of the shared region */ - uint32_t nr_numdescs; /* descriptors per queue */ - uint16_t nr_numqueues; + uint32_t nr_tx_slots; /* slots in tx rings */ + uint32_t nr_rx_slots; /* slots in rx rings */ + uint16_t nr_tx_rings; /* number of tx rings */ + uint16_t nr_rx_rings; /* number of tx rings */ uint16_t nr_ringid; /* ring(s) we care about */ #define NETMAP_HW_RING 0x4000 /* low bits indicate one hw ring */ #define NETMAP_SW_RING 0x2000 /* we process the sw ring */ @@ -199,8 +201,10 @@ and are: returns information about the interface named in nr_name. On return, nr_memsize indicates the size of the shared netmap memory region (this is device-independent), -nr_numslots indicates how many buffers are in a ring, -nr_numrings indicates the number of rings supported by the hardware. +nr_tx_slots and nr_rx_slots indicates how many buffers are in a +transmit and receive ring, +nr_tx_rings and nr_rx_rings indicates the number of transmit +and receive rings supported by the hardware. .Pp If the device does not support netmap, the ioctl returns EINVAL. .It Dv NIOCREGIF @@ -266,6 +270,7 @@ struct netmap_request nmr; fd = open("/dev/netmap", O_RDWR); bzero(&nmr, sizeof(nmr)); strcpy(nmr.nm_name, "ix0"); +nmr.nm_version = NETMAP_API; ioctl(fd, NIOCREG, &nmr); p = mmap(0, nmr.memsize, fd); nifp = NETMAP_IF(p, nmr.offset); |
