/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (C) 2011-2016 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_
#define NETMAP_DEVICE_NAME "/dev/netmap"
#ifdef __CYGWIN__
/*
* we can compile userspace apps with either cygwin or msvc,
* and we use _WIN32 to identify windows specific code
*/
#ifndef _WIN32
#define _WIN32
#endif /* _WIN32 */
#endif /* __CYGWIN__ */
#ifdef _WIN32
#undef NETMAP_DEVICE_NAME
#define NETMAP_DEVICE_NAME "/proc/sys/DosDevices/Global/netmap"
#include <windows.h>
#include <WinDef.h>
#include <sys/cygwin.h>
#endif /* _WIN32 */
#include <stdint.h>
#include <sys/socket.h> /* apple needs sockaddr */
#include <net/if.h> /* IFNAMSIZ */
#include <ctype.h>
#include <string.h> /* memset */
#include <sys/time.h> /* gettimeofday */
#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 + \
(nifp)->ni_host_tx_rings] )
#define NETMAP_BUF(ring, index) \
((char *)(ring) + (ring)->buf_ofs + ((size_t)(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;
}
/* Compute the number of slots available in the netmap ring. We use
* ring->head as explained in the comment above nm_ring_empty(). */
static inline uint32_t
nm_ring_space(struct netmap_ring *ring)
{
int ret = ring->tail - ring->head;
if (ret < 0)
ret += ring->num_slots;
return ret;
}
#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
/*
* 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.
*/
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 || l % 64)) {
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++;
}
}
#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 <sys/ioctl.h>
#include <sys/errno.h> /* EINVAL */
#include <fcntl.h> /* O_RDWR */
#include <unistd.h> /* close() */
#include <signal.h>
#include <stdlib.h>
struct nm_pkthdr { /* first part is the same as pcap_pkthdr */
struct timeval ts;
uint32_t caplen;
uint32_t len;
uint64_t flags; /* NM_MORE_PKTS etc */
#define NM_MORE_PKTS 1
struct nm_desc *d;
struct netmap_slot *slot;
uint8_t *buf;
};
struct nm_stat { /* same as pcap_stat */
u_int ps_recv;
u_int ps_drop;
u_int ps_ifdrop;
#ifdef WIN32 /* XXX or _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;
size_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) ((const struct nm_desc *)(p))
#define IS_NETMAP_DESC(d) ((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_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
* -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 (both tx and rx)
* t monitor tx side (copy monitor)
* r monitor rx side (copy monitor)
* R bind only RX ring(s)
* T bind only TX ring(s)
*
* 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_mmap() do mmap or inherit from parent if the nr_arg2
* (memory block) matches.
*/
static int nm_mmap(struct nm_desc *, const 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 *);
#ifdef _WIN32
intptr_t _get_osfhandle(int); /* defined in io.h in windows */
/*
* In windows we do not have yet native poll support, so we keep track
* of file descriptors associated to netmap ports to emulate poll on
* them and fall back on regular poll on other file descriptors.
*/
struct win_netmap_fd_list {
struct win_netmap_fd_list *next;
int win_netmap_fd;
HANDLE win_netmap_handle;
};
/*
* list head containing all the netmap opened fd and their
* windows HANDLE counterparts
*/
static struct win_netmap_fd_list *win_netmap_fd_list_head;
static void
win_insert_fd_record(int fd)
{
struct win_netmap_fd_list *curr;
for (curr = win_netmap_fd_list_head; curr; curr = curr->next) {
if (fd == curr->win_netmap_fd) {
return;
}
}
curr = calloc(1, sizeof(*curr));
curr->next = win_netmap_fd_list_head;
curr->win_netmap_fd = fd;
curr->win_netmap_handle = IntToPtr(_get_osfhandle(fd));
win_netmap_fd_list_head = curr;
}
void
win_remove_fd_record(int fd)
{
struct win_netmap_fd_list *curr = win_netmap_fd_list_head;
struct win_netmap_fd_list *prev = NULL;
for (; curr ; prev = curr, curr = curr->next) {
if (fd != curr->win_netmap_fd)
continue;
/* found the entry */
if (prev == NULL) { /* we are freeing the first entry */
win_netmap_fd_list_head = curr->next;
} else {
prev->next = curr->next;
}
free(curr);
break;
}
}
HANDLE
win_get_netmap_handle(int fd)
{
struct win_netmap_fd_list *curr;
for (curr = win_netmap_fd_list_head; curr; curr = curr->next) {
if (fd == curr->win_netmap_fd) {
return curr->win_netmap_handle;
}
}
return NULL;
}
/*
* we need to wrap ioctl and mmap, at least for the netmap file descriptors
*/
/*
* use this function only from netmap_user.h internal functions
* same as ioctl, returns 0 on success and -1 on error
*/
static int
win_nm_ioctl_internal(HANDLE h, int32_t ctlCode, void *arg)
{
DWORD bReturn = 0, szIn, szOut;
BOOL ioctlReturnStatus;
void *inParam = arg, *outParam = arg;
switch (ctlCode) {
case NETMAP_POLL:
szIn = sizeof(POLL_REQUEST_DATA);
szOut = sizeof(POLL_REQUEST_DATA);
break;
case NETMAP_MMAP:
szIn = 0;
szOut = sizeof(void*);
inParam = NULL; /* nothing on input */
break;
case NIOCTXSYNC:
case NIOCRXSYNC:
szIn = 0;
szOut = 0;
break;
case NIOCREGIF:
szIn = sizeof(struct nmreq);
szOut = sizeof(struct nmreq);
break;
case NIOCCONFIG:
D("unsupported NIOCCONFIG!");
return -1;
default: /* a regular ioctl */
D("invalid ioctl %x on netmap fd", ctlCode);
return -1;
}
ioctlReturnStatus = DeviceIoControl(h,
ctlCode, inParam, szIn,
outParam, szOut,
&bReturn, NULL);
// XXX note windows returns 0 on error or async call, 1 on success
// we could call GetLastError() to figure out what happened
return ioctlReturnStatus ? 0 : -1;
}
/*
* this function is what must be called from user-space programs
* same as ioctl, returns 0 on success and -1 on error
*/
static int
win_nm_ioctl(int fd, int32_t ctlCode, void *arg)
{
HANDLE h = win_get_netmap_handle(fd);
if (h == NULL) {
return ioctl(fd, ctlCode, arg);
} else {
return win_nm_ioctl_internal(h, ctlCode, arg);
}
}
#define ioctl win_nm_ioctl /* from now on, within this file ... */
/*
* We cannot use the native mmap on windows
* The only parameter used is "fd", the other ones are just declared to
* make this signature comparable to the FreeBSD/Linux one
*/
static void *
win32_mmap_emulated(void *addr, size_t length, int prot, int flags, int fd, int32_t offset)
{
HANDLE h = win_get_netmap_handle(fd);
if (h == NULL) {
return mmap(addr, length, prot, flags, fd, offset);
} else {
MEMORY_ENTRY ret;
return win_nm_ioctl_internal(h, NETMAP_MMAP, &ret) ?
NULL : ret.pUsermodeVirtualAddress;
}
}
#define mmap win32_mmap_emulated
#include <sys/poll.h> /* XXX needed to use the structure pollfd */
static int
win_nm_poll(struct pollfd *fds, int nfds, int timeout)
{
HANDLE h;
if (nfds != 1 || fds == NULL || (h = win_get_netmap_handle(fds->fd)) == NULL) {;
return poll(fds, nfds, timeout);
} else {
POLL_REQUEST_DATA prd;
prd.timeout = timeout;
prd.events = fds->events;
win_nm_ioctl_internal(h, NETMAP_POLL, &prd);
if ((prd.revents == POLLERR) || (prd.revents == STATUS_TIMEOUT)) {
return -1;
}
return 1;
}
}
#define poll win_nm_poll
static int
win_nm_open(char* pathname, int flags)
{
if (strcmp(pathname, NETMAP_DEVICE_NAME) == 0) {
int fd = open(NETMAP_DEVICE_NAME, O_RDWR);
if (fd < 0) {
return -1;
}
win_insert_fd_record(fd);
return fd;
} else {
return open(pathname, flags);
}
}
#define open win_nm_open
static int
win_nm_close(int fd)
{
if (fd != -1) {
close(fd);
if (win_get_netmap_handle(fd) != NULL) {
win_remove_fd_record(fd);
}
}
return 0;
}
#define close win_nm_close
#endif /* _WIN32 */
static int
nm_is_identifier(const char *s, const char *e)
{
for (; s != e; s++) {
if (!isalnum(*s) && *s != '_') {
return 0;
}
}
return 1;
}
#define MAXERRMSG 80
static int
nm_parse(const char *ifname, struct nm_desc *d, char *err)
{
int is_vale;
const char *port = NULL;
const char *vpname = NULL;
u_int namelen;
uint32_t nr_ringid = 0, nr_flags;
char errmsg[MAXERRMSG] = "", *tmp;
long num;
uint16_t nr_arg2 = 0;
enum { P_START, P_RNGSFXOK, P_GETNUM, P_FLAGS, P_FLAGSOK, P_MEMID } p_state;
errno = 0;
is_vale = (ifname[0] == 'v');
if (is_vale) {
port = index(ifname, ':');
if (port == NULL) {
snprintf(errmsg, MAXERRMSG,
"missing ':' in vale name");
goto fail;
}
if (!nm_is_identifier(ifname + 4, port)) {
snprintf(errmsg, MAXERRMSG, "invalid bridge name");
goto fail;
}
vpname = ++port;
} else {
ifname += 7;
port = ifname;
}
/* scan for a separator */
for (; *port && !index("-*^{}/@", *port); port++)
;
if (is_vale && !nm_is_identifier(vpname, port)) {
snprintf(errmsg, MAXERRMSG, "invalid bridge port name");
goto fail;
}
namelen = port - ifname;
if (namelen >= sizeof(d->req.nr_name)) {
snprintf(errmsg, MAXERRMSG, "name too long");
goto fail;
}
memcpy(d->req.nr_name, ifname, namelen);
d->req.nr_name[namelen] = '\0';
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;
case '@': /* start of memid */
p_state = P_MEMID;
break;
default:
snprintf(errmsg, MAXERRMSG, "unknown modifier: '%c'", *port);
goto fail;
}
port++;
break;
case P_RNGSFXOK:
switch (*port) {
case '/':
p_state = P_FLAGS;
break;
case '@':
p_state = P_MEMID;
break;
default:
snprintf(errmsg, MAXERRMSG, "unexpected character: '%c'", *port);
goto fail;
}
port++;
break;
case P_GETNUM:
num = strtol(port, &tmp, 10);
if (num < 0 || num >= NETMAP_RING_MASK) {
snprintf(errmsg, MAXERRMSG, "'%ld' out of range [0, %d)",
num, NETMAP_RING_MASK);
goto fail;
}
port = tmp;
nr_ringid = num & NETMAP_RING_MASK;
p_state = P_RNGSFXOK;
break;
case P_FLAGS:
case P_FLAGSOK:
if (*port == '@') {
port++;
p_state = P_MEMID;
break;
}
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;
case 'R':
nr_flags |= NR_RX_RINGS_ONLY;
break;
case 'T':
nr_flags |= NR_TX_RINGS_ONLY;
break;
default:
snprintf(errmsg, MAXERRMSG, "unrecognized flag: '%c'", *port);
goto fail;
}
port++;
p_state = P_FLAGSOK;
break;
case P_MEMID:
if (nr_arg2 != 0) {
snprintf(errmsg, MAXERRMSG, "double setting of memid");
goto fail;
}
num = strtol(port, &tmp, 10);
if (num <= 0) {
snprintf(errmsg, MAXERRMSG, "invalid memid %ld, must be >0", num);
goto fail;
}
port = tmp;
nr_arg2 = num;
p_state = P_RNGSFXOK;
break;
}
}
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->req.nr_flags |= nr_flags;
d->req.nr_ringid |= nr_ringid;
d->req.nr_arg2 = nr_arg2;
d->self = d;
return 0;
fail:
if (!errno)
errno = EINVAL;
if (err)
strncpy(err, errmsg, MAXERRMSG);
return -1;
}
/*
* 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 XXX avoid mmap
* 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;
char errmsg[MAXERRMSG] = "";
uint32_t nr_reg;
if (strncmp(ifname, "netmap:", 7) &&
strncmp(ifname, NM_BDG_NAME, strlen(NM_BDG_NAME))) {
errno = 0; /* name not recognised, not an error */
return NULL;
}
d = (struct nm_desc *)calloc(1, sizeof(*d));
if (d == NULL) {
snprintf(errmsg, MAXERRMSG, "nm_desc alloc failure");
errno = ENOMEM;
return NULL;
}
d->self = d; /* set this early so nm_close() works */
d->fd = open(NETMAP_DEVICE_NAME, O_RDWR);
if (d->fd < 0) {
snprintf(errmsg, MAXERRMSG, "cannot open /dev/netmap: %s", strerror(errno));
goto fail;
}
if (req)
d->req = *req;
if (!(new_flags & NM_OPEN_IFNAME)) {
if (nm_parse(ifname, d, errmsg) < 0)
goto fail;
}
d->req.nr_version = NETMAP_API;
d->req.nr_ringid &= NETMAP_RING_MASK;
/* 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 = parent->req.nr_arg2;
}
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)) {
snprintf(errmsg, MAXERRMSG, "NIOCREGIF failed: %s", strerror(errno));
goto fail;
}
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 (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 (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 (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;
} else { /* pipes */
d->first_tx_ring = d->last_tx_ring = 0;
d->first_rx_ring = d->last_rx_ring = 0;
}
/* if parent is defined, do nm_mmap() even if NM_OPEN_NO_MMAP is set */
if ((!(new_flags & NM_OPEN_NO_MMAP) || parent) && nm_mmap(d, parent)) {
snprintf(errmsg, MAXERRMSG, "mmap failed: %s", strerror(errno));
goto fail;
}
#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[0])
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;
}
static int
nm_mmap(struct nm_desc *d, const struct nm_desc *parent)
{
if (d->done_mmap)
return 0;
if (IS_NETMAP_DESC(parent) && parent->mem &&
parent->req.nr_arg2 == d->req.nr_arg2) {
/* do not mmap, inherit from parent */
D("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) {
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, d->first_rx_ring);
if ((void *)r == (void *)nifp) {
/* the descriptor is open for TX only */
r = NETMAP_TXRING(nifp, d->first_tx_ring);
}
*(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;
}
return 0;
fail:
return EINVAL;
}
/*
* 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,
ri = d->cur_tx_ring;
for (c = 0; c < n ; c++, ri++) {
/* compute current ring to use */
struct netmap_ring *ring;
uint32_t i, j, idx;
size_t rem;
if (ri > d->last_tx_ring)
ri = d->first_tx_ring;
ring = NETMAP_TXRING(d->nifp, ri);
rem = size;
j = ring->cur;
while (rem > ring->nr_buf_size && j != ring->tail) {
rem -= ring->nr_buf_size;
j = nm_ring_next(ring, j);
}
if (j == ring->tail && rem > 0)
continue;
i = ring->cur;
while (i != j) {
idx = ring->slot[i].buf_idx;
ring->slot[i].len = ring->nr_buf_size;
ring->slot[i].flags = NS_MOREFRAG;
nm_pkt_copy(buf, NETMAP_BUF(ring, idx), ring->nr_buf_size);
i = nm_ring_next(ring, i);
buf = (const char *)buf + ring->nr_buf_size;
}
idx = ring->slot[i].buf_idx;
ring->slot[i].len = rem;
ring->slot[i].flags = 0;
nm_pkt_copy(buf, NETMAP_BUF(ring, idx), rem);
ring->head = ring->cur = nm_ring_next(ring, i);
d->cur_tx_ring = ri;
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;
d->hdr.buf = NULL;
d->hdr.flags = NM_MORE_PKTS;
d->hdr.d = d;
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++, ri++) {
/* compute current ring to use */
struct netmap_ring *ring;
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 idx, i;
u_char *oldbuf;
struct netmap_slot *slot;
if (d->hdr.buf) { /* from previous round */
cb(arg, &d->hdr, d->hdr.buf);
}
i = ring->cur;
slot = &ring->slot[i];
idx = slot->buf_idx;
/* d->cur_rx_ring doesn't change inside this loop, but
* set it here, so it reflects d->hdr.buf's ring */
d->cur_rx_ring = ri;
d->hdr.slot = slot;
oldbuf = d->hdr.buf = (u_char *)NETMAP_BUF(ring, idx);
// __builtin_prefetch(buf);
d->hdr.len = d->hdr.caplen = slot->len;
while (slot->flags & NS_MOREFRAG) {
u_char *nbuf;
u_int oldlen = slot->len;
i = nm_ring_next(ring, i);
slot = &ring->slot[i];
d->hdr.len += slot->len;
nbuf = (u_char *)NETMAP_BUF(ring, slot->buf_idx);
if (oldbuf != NULL && nbuf - oldbuf == (int)ring->nr_buf_size &&
oldlen == ring->nr_buf_size) {
d->hdr.caplen += slot->len;
oldbuf = nbuf;
} else {
oldbuf = NULL;
}
}
d->hdr.ts = ring->ts;
ring->head = ring->cur = nm_ring_next(ring, i);
}
}
if (d->hdr.buf) { /* from previous round */
d->hdr.flags = 0;
cb(arg, &d->hdr, d->hdr.buf);
}
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_ */