freebsd-dev/sys/net/netmap_user.h
Luigi Rizzo 0506889c15 return kernel-supplied error if available.
Also fix field names in a comment.
2014-11-10 08:31:56 +00:00

682 lines
19 KiB
C

/*
* Copyright (C) 2011-2014 Universita` di Pisa. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* 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.
*
* 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 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.
*/
/*
* $FreeBSD$
*
* Functions and macros to manipulate netmap structures and packets
* in userspace. See netmap(4) for more information.
*
* The address of the struct netmap_if, say nifp, is computed from the
* value returned from ioctl(.., NIOCREG, ...) and the mmap region:
* ioctl(fd, NIOCREG, &req);
* mem = mmap(0, ... );
* nifp = NETMAP_IF(mem, req.nr_nifp);
* (so simple, we could just do it manually)
*
* From there:
* struct netmap_ring *NETMAP_TXRING(nifp, index)
* struct netmap_ring *NETMAP_RXRING(nifp, index)
* we can access ring->cur, ring->head, ring->tail, etc.
*
* ring->slot[i] gives us the i-th slot (we can access
* directly len, flags, buf_idx)
*
* char *buf = NETMAP_BUF(ring, x) returns a pointer to
* the buffer numbered x
*
* All ring indexes (head, cur, tail) should always move forward.
* To compute the next index in a circular ring you can use
* i = nm_ring_next(ring, i);
*
* To ease porting apps from pcap to netmap we supply a few fuctions
* that can be called to open, close, read and write on netmap in a way
* similar to libpcap. Note that the read/write function depend on
* an ioctl()/select()/poll() being issued to refill rings or push
* packets out.
*
* 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 <sys/socket.h> /* apple needs sockaddr */
#include <net/if.h> /* IFNAMSIZ */
#ifndef likely
#define likely(x) __builtin_expect(!!(x), 1)
#define unlikely(x) __builtin_expect(!!(x), 0)
#endif /* likely and unlikely */
#include <net/netmap.h>
/* helper macro */
#define _NETMAP_OFFSET(type, ptr, offset) \
((type)(void *)((char *)(ptr) + (offset)))
#define NETMAP_IF(_base, _ofs) _NETMAP_OFFSET(struct netmap_if *, _base, _ofs)
#define NETMAP_TXRING(nifp, index) _NETMAP_OFFSET(struct netmap_ring *, \
nifp, (nifp)->ring_ofs[index] )
#define NETMAP_RXRING(nifp, index) _NETMAP_OFFSET(struct netmap_ring *, \
nifp, (nifp)->ring_ofs[index + (nifp)->ni_tx_rings + 1] )
#define NETMAP_BUF(ring, index) \
((char *)(ring) + (ring)->buf_ofs + ((index)*(ring)->nr_buf_size))
#define NETMAP_BUF_IDX(ring, buf) \
( ((char *)(buf) - ((char *)(ring) + (ring)->buf_ofs) ) / \
(ring)->nr_buf_size )
static inline uint32_t
nm_ring_next(struct netmap_ring *r, uint32_t i)
{
return ( unlikely(i + 1 == r->num_slots) ? 0 : i + 1);
}
/*
* Return 1 if we have pending transmissions in the tx ring.
* When everything is complete ring->head = ring->tail + 1 (modulo ring size)
*/
static inline int
nm_tx_pending(struct netmap_ring *r)
{
return nm_ring_next(r, r->tail) != r->head;
}
static inline uint32_t
nm_ring_space(struct netmap_ring *ring)
{
int ret = ring->tail - ring->cur;
if (ret < 0)
ret += ring->num_slots;
return ret;
}
#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 <stdio.h>
#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 <unistd.h> /* close() */
#include <signal.h>
#include <stdlib.h>
#ifndef ND /* debug macros */
/* debug support */
#define ND(_fmt, ...) do {} while(0)
#define D(_fmt, ...) \
do { \
struct timeval _t0; \
gettimeofday(&_t0, NULL); \
fprintf(stderr, "%03d.%06d %s [%d] " _fmt "\n", \
(int)(_t0.tv_sec % 1000), (int)_t0.tv_usec, \
__FUNCTION__, __LINE__, ##__VA_ARGS__); \
} while (0)
/* Rate limited version of "D", lps indicates how many per second */
#define RD(lps, format, ...) \
do { \
static int __t0, __cnt; \
struct timeval __xxts; \
gettimeofday(&__xxts, NULL); \
if (__t0 != __xxts.tv_sec) { \
__t0 = __xxts.tv_sec; \
__cnt = 0; \
} \
if (__cnt++ < lps) { \
D(format, ##__VA_ARGS__); \
} \
} while (0)
#endif
struct nm_pkthdr { /* same as pcap_pkthdr */
struct timeval ts;
uint32_t caplen;
uint32_t len;
};
struct nm_stat { /* same as pcap_stat */
u_int ps_recv;
u_int ps_drop;
u_int ps_ifdrop;
#ifdef WIN32
u_int bs_capt;
#endif /* WIN32 */
};
#define NM_ERRBUF_SIZE 512
struct nm_desc {
struct nm_desc *self; /* point to self if netmap. */
int fd;
void *mem;
uint32_t memsize;
int done_mmap; /* set if mem is the result of mmap */
struct netmap_if * const nifp;
uint16_t first_tx_ring, last_tx_ring, cur_tx_ring;
uint16_t first_rx_ring, last_rx_ring, cur_rx_ring;
struct nmreq req; /* also contains the nr_name = ifname */
struct nm_pkthdr hdr;
/*
* The memory contains netmap_if, rings and then buffers.
* Given a pointer (e.g. to nm_inject) we can compare with
* mem/buf_start/buf_end to tell if it is a buffer or
* some other descriptor in our region.
* We also store a pointer to some ring as it helps in the
* translation from buffer indexes to addresses.
*/
struct netmap_ring * const some_ring;
void * const buf_start;
void * const buf_end;
/* parameters from pcap_open_live */
int snaplen;
int promisc;
int to_ms;
char *errbuf;
/* save flags so we can restore them on close */
uint32_t if_flags;
uint32_t if_reqcap;
uint32_t if_curcap;
struct nm_stat st;
char msg[NM_ERRBUF_SIZE];
};
/*
* when the descriptor is open correctly, d->self == d
* Eventually we should also use some magic number.
*/
#define P2NMD(p) ((struct nm_desc *)(p))
#define IS_NETMAP_DESC(d) ((d) && P2NMD(d)->self == P2NMD(d))
#define NETMAP_FD(d) (P2NMD(d)->fd)
/*
* this is a slightly optimized copy routine which rounds
* to multiple of 64 bytes and is often faster than dealing
* with other odd sizes. We assume there is enough room
* in the source and destination buffers.
*
* XXX only for multiples of 64 bytes, non overlapped.
*/
static inline void
nm_pkt_copy(const void *_src, void *_dst, int l)
{
const uint64_t *src = (const uint64_t *)_src;
uint64_t *dst = (uint64_t *)_dst;
if (unlikely(l >= 1024)) {
memcpy(dst, src, l);
return;
}
for (; likely(l > 0); l-=64) {
*dst++ = *src++;
*dst++ = *src++;
*dst++ = *src++;
*dst++ = *src++;
*dst++ = *src++;
*dst++ = *src++;
*dst++ = *src++;
*dst++ = *src++;
}
}
/*
* The callback, invoked on each received packet. Same as libpcap
*/
typedef void (*nm_cb_t)(u_char *, const struct nm_pkthdr *, const u_char *d);
/*
*--- the pcap-like API ---
*
* nm_open() opens a file descriptor, binds to a port and maps memory.
*
* ifname (netmap:foo or vale:foo) is the port name
* a suffix can indicate the follwing:
* ^ bind the host (sw) ring pair
* * bind host and NIC ring pairs (transparent)
* -NN bind individual NIC ring pair
* {NN bind master side of pipe NN
* }NN bind slave side of pipe NN
*
* req provides the initial values of nmreq before parsing ifname.
* Remember that the ifname parsing will override the ring
* number in nm_ringid, and part of nm_flags;
* flags special functions, normally 0
* indicates which fields of *arg are significant
* arg special functions, normally NULL
* if passed a netmap_desc with mem != NULL,
* use that memory instead of mmap.
*/
static struct nm_desc *nm_open(const char *ifname, const struct nmreq *req,
uint64_t flags, const struct nm_desc *arg);
/*
* nm_open can import some fields from the parent descriptor.
* These flags control which ones.
* Also in flags you can specify NETMAP_NO_TX_POLL and NETMAP_DO_RX_POLL,
* which set the initial value for these flags.
* Note that the 16 low bits of the flags are reserved for data
* that may go into the nmreq.
*/
enum {
NM_OPEN_NO_MMAP = 0x040000, /* reuse mmap from parent */
NM_OPEN_IFNAME = 0x080000, /* nr_name, nr_ringid, nr_flags */
NM_OPEN_ARG1 = 0x100000,
NM_OPEN_ARG2 = 0x200000,
NM_OPEN_ARG3 = 0x400000,
NM_OPEN_RING_CFG = 0x800000, /* tx|rx rings|slots */
};
/*
* nm_close() closes and restores the port to its previous state
*/
static int nm_close(struct nm_desc *);
/*
* nm_inject() is the same as pcap_inject()
* nm_dispatch() is the same as pcap_dispatch()
* nm_nextpkt() is the same as pcap_next()
*/
static int nm_inject(struct nm_desc *, const void *, size_t);
static int nm_dispatch(struct nm_desc *, int, nm_cb_t, u_char *);
static u_char *nm_nextpkt(struct nm_desc *, struct nm_pkthdr *);
/*
* Try to open, return descriptor if successful, NULL otherwise.
* An invalid netmap name will return errno = 0;
* You can pass a pointer to a pre-filled nm_desc to add special
* parameters. Flags is used as follows
* NM_OPEN_NO_MMAP use the memory from arg, only
* if the nr_arg2 (memory block) matches.
* NM_OPEN_ARG1 use req.nr_arg1 from arg
* NM_OPEN_ARG2 use req.nr_arg2 from arg
* NM_OPEN_RING_CFG user ring config from arg
*/
static struct nm_desc *
nm_open(const char *ifname, const struct nmreq *req,
uint64_t new_flags, const struct nm_desc *arg)
{
struct nm_desc *d = NULL;
const struct nm_desc *parent = arg;
u_int namelen;
uint32_t nr_ringid = 0, nr_flags;
const char *port = NULL;
const char *errmsg = NULL;
if (strncmp(ifname, "netmap:", 7) && strncmp(ifname, "vale", 4)) {
errno = 0; /* name not recognised, not an error */
return NULL;
}
if (ifname[0] == 'n')
ifname += 7;
/* scan for a separator */
for (port = ifname; *port && !index("-*^{}", *port); port++)
;
namelen = port - ifname;
if (namelen >= sizeof(d->req.nr_name)) {
errmsg = "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;
}
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";
goto fail;
}
d = (struct nm_desc *)calloc(1, sizeof(*d));
if (d == NULL) {
errmsg = "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";
goto fail;
}
if (req)
d->req = *req;
d->req.nr_version = NETMAP_API;
d->req.nr_ringid &= ~NETMAP_RING_MASK;
/* these fields are overridden by ifname and flags processing */
d->req.nr_ringid |= nr_ringid;
d->req.nr_flags = nr_flags;
memcpy(d->req.nr_name, ifname, namelen);
d->req.nr_name[namelen] = '\0';
/* optionally import info from parent */
if (IS_NETMAP_DESC(parent) && new_flags) {
if (new_flags & NM_OPEN_ARG1)
D("overriding ARG1 %d", parent->req.nr_arg1);
d->req.nr_arg1 = new_flags & NM_OPEN_ARG1 ?
parent->req.nr_arg1 : 4;
if (new_flags & NM_OPEN_ARG2)
D("overriding ARG2 %d", parent->req.nr_arg2);
d->req.nr_arg2 = new_flags & NM_OPEN_ARG2 ?
parent->req.nr_arg2 : 0;
if (new_flags & NM_OPEN_ARG3)
D("overriding ARG3 %d", parent->req.nr_arg3);
d->req.nr_arg3 = new_flags & NM_OPEN_ARG3 ?
parent->req.nr_arg3 : 0;
if (new_flags & NM_OPEN_RING_CFG) {
D("overriding RING_CFG");
d->req.nr_tx_slots = parent->req.nr_tx_slots;
d->req.nr_rx_slots = parent->req.nr_rx_slots;
d->req.nr_tx_rings = parent->req.nr_tx_rings;
d->req.nr_rx_rings = parent->req.nr_rx_rings;
}
if (new_flags & NM_OPEN_IFNAME) {
D("overriding ifname %s ringid 0x%x flags 0x%x",
parent->req.nr_name, parent->req.nr_ringid,
parent->req.nr_flags);
memcpy(d->req.nr_name, parent->req.nr_name,
sizeof(d->req.nr_name));
d->req.nr_ringid = parent->req.nr_ringid;
d->req.nr_flags = parent->req.nr_flags;
}
}
/* add the *XPOLL flags */
d->req.nr_ringid |= new_flags & (NETMAP_NO_TX_POLL | NETMAP_DO_RX_POLL);
if (ioctl(d->fd, NIOCREGIF, &d->req)) {
errmsg = "NIOCREGIF failed";
goto fail;
}
if (IS_NETMAP_DESC(parent) && parent->mem &&
parent->req.nr_arg2 == d->req.nr_arg2) {
/* do not mmap, inherit from parent */
d->memsize = parent->memsize;
d->mem = parent->mem;
} else {
/* XXX TODO: check if memsize is too large (or there is overflow) */
d->memsize = d->req.nr_memsize;
d->mem = mmap(0, d->memsize, PROT_WRITE | PROT_READ, MAP_SHARED,
d->fd, 0);
if (d->mem == MAP_FAILED) {
errmsg = "mmap failed";
goto fail;
}
d->done_mmap = 1;
}
{
struct netmap_if *nifp = NETMAP_IF(d->mem, d->req.nr_offset);
struct netmap_ring *r = NETMAP_RXRING(nifp, );
*(struct netmap_if **)(uintptr_t)&(d->nifp) = nifp;
*(struct netmap_ring **)(uintptr_t)&d->some_ring = r;
*(void **)(uintptr_t)&d->buf_start = NETMAP_BUF(r, 0);
*(void **)(uintptr_t)&d->buf_end =
(char *)d->mem + d->memsize;
}
if (d->req.nr_flags == 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 */
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) {
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) {
/* 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;
} else { /* pipes */
d->first_tx_ring = d->last_tx_ring = 0;
d->first_rx_ring = d->last_rx_ring = 0;
}
#ifdef DEBUG_NETMAP_USER
{ /* debugging code */
int i;
D("%s tx %d .. %d %d rx %d .. %d %d", ifname,
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);
for (i = 0; i <= d->req.nr_tx_rings; i++) {
struct netmap_ring *r = NETMAP_TXRING(d->nifp, i);
D("TX%d %p h %d c %d t %d", i, r, r->head, r->cur, r->tail);
}
for (i = 0; i <= d->req.nr_rx_rings; i++) {
struct netmap_ring *r = NETMAP_RXRING(d->nifp, i);
D("RX%d %p h %d c %d t %d", i, r, r->head, r->cur, r->tail);
}
}
#endif /* debugging */
d->cur_tx_ring = d->first_tx_ring;
d->cur_rx_ring = d->first_rx_ring;
return d;
fail:
nm_close(d);
if (errmsg)
D("%s %s", errmsg, ifname);
if (errno == 0)
errno = EINVAL;
return NULL;
}
static int
nm_close(struct nm_desc *d)
{
/*
* ugly trick to avoid unused warnings
*/
static void *__xxzt[] __attribute__ ((unused)) =
{ (void *)nm_open, (void *)nm_inject,
(void *)nm_dispatch, (void *)nm_nextpkt } ;
if (d == NULL || d->self != d)
return EINVAL;
if (d->done_mmap && 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_inject(), only need to cast.
*/
static int
nm_inject(struct nm_desc *d, const void *buf, size_t size)
{
u_int c, n = d->last_tx_ring - d->first_tx_ring + 1;
for (c = 0; c < n ; c++) {
/* compute current ring to use */
struct netmap_ring *ring;
uint32_t i, idx;
uint32_t ri = d->cur_tx_ring + c;
if (ri > d->last_tx_ring)
ri = d->first_tx_ring;
ring = NETMAP_TXRING(d->nifp, ri);
if (nm_ring_empty(ring)) {
continue;
}
i = ring->cur;
idx = ring->slot[i].buf_idx;
ring->slot[i].len = size;
nm_pkt_copy(buf, NETMAP_BUF(ring, idx), size);
d->cur_tx_ring = ri;
ring->head = ring->cur = nm_ring_next(ring, i);
return size;
}
return 0; /* fail */
}
/*
* Same prototype as pcap_dispatch(), only need to cast.
*/
static int
nm_dispatch(struct nm_desc *d, int cnt, nm_cb_t cb, u_char *arg)
{
int n = d->last_rx_ring - d->first_rx_ring + 1;
int c, got = 0, ri = d->cur_rx_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_rx_ring + c;
if (ri > d->last_rx_ring)
ri = d->first_rx_ring;
ring = NETMAP_RXRING(d->nifp, ri);
for ( ; !nm_ring_empty(ring) && 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);
// __builtin_prefetch(buf);
d->hdr.len = d->hdr.caplen = ring->slot[i].len;
d->hdr.ts = ring->ts;
cb(arg, &d->hdr, buf);
ring->head = ring->cur = nm_ring_next(ring, i);
}
}
d->cur_rx_ring = ri;
return got;
}
static u_char *
nm_nextpkt(struct nm_desc *d, struct nm_pkthdr *hdr)
{
int ri = d->cur_rx_ring;
do {
/* compute current ring to use */
struct netmap_ring *ring = NETMAP_RXRING(d->nifp, ri);
if (!nm_ring_empty(ring)) {
u_int i = ring->cur;
u_int idx = ring->slot[i].buf_idx;
u_char *buf = (u_char *)NETMAP_BUF(ring, idx);
// __builtin_prefetch(buf);
hdr->ts = ring->ts;
hdr->len = hdr->caplen = ring->slot[i].len;
ring->cur = nm_ring_next(ring, i);
/* we could postpone advancing head if we want
* to hold the buffer. This can be supported in
* the future.
*/
ring->head = ring->cur;
d->cur_rx_ring = ri;
return buf;
}
ri++;
if (ri > d->last_rx_ring)
ri = d->first_rx_ring;
} while (ri != d->cur_rx_ring);
return NULL; /* nothing found */
}
#endif /* !HAVE_NETMAP_WITH_LIBS */
#endif /* NETMAP_WITH_LIBS */
#endif /* _NET_NETMAP_USER_H_ */