freebsd-dev/lib/libnetmap/nmport.c
Vincenzo Maffione f8113f0a65 libnetmap: add support for the offset features
The companion libnetmap changes for the "offsets" kernel support added
in a6d768d845. This includes code to parse the "@offset=NNN"
option that can be appended to the port name by any nmport_* application.
Example:
   # pkt-gen -i 'netmap:em0@offset=16'
2021-03-29 16:38:37 +00:00

915 lines
20 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (C) 2018 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.
*
* $FreeBSD$
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <inttypes.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <net/netmap_user.h>
#define LIBNETMAP_NOTHREADSAFE
#include "libnetmap.h"
struct nmport_cleanup_d {
struct nmport_cleanup_d *next;
void (*cleanup)(struct nmport_cleanup_d *, struct nmport_d *);
};
static void
nmport_push_cleanup(struct nmport_d *d, struct nmport_cleanup_d *c)
{
c->next = d->clist;
d->clist = c;
}
static void
nmport_pop_cleanup(struct nmport_d *d)
{
struct nmport_cleanup_d *top;
top = d->clist;
d->clist = d->clist->next;
(*top->cleanup)(top, d);
nmctx_free(d->ctx, top);
}
void nmport_do_cleanup(struct nmport_d *d)
{
while (d->clist != NULL) {
nmport_pop_cleanup(d);
}
}
static struct nmport_d *
nmport_new_with_ctx(struct nmctx *ctx)
{
struct nmport_d *d;
/* allocate a descriptor */
d = nmctx_malloc(ctx, sizeof(*d));
if (d == NULL) {
nmctx_ferror(ctx, "cannot allocate nmport descriptor");
goto out;
}
memset(d, 0, sizeof(*d));
nmreq_header_init(&d->hdr, NETMAP_REQ_REGISTER, &d->reg);
d->ctx = ctx;
d->fd = -1;
out:
return d;
}
struct nmport_d *
nmport_new(void)
{
struct nmctx *ctx = nmctx_get();
return nmport_new_with_ctx(ctx);
}
void
nmport_delete(struct nmport_d *d)
{
nmctx_free(d->ctx, d);
}
void
nmport_extmem_cleanup(struct nmport_cleanup_d *c, struct nmport_d *d)
{
(void)c;
if (d->extmem == NULL)
return;
nmreq_remove_option(&d->hdr, &d->extmem->nro_opt);
nmctx_free(d->ctx, d->extmem);
d->extmem = NULL;
}
int
nmport_extmem(struct nmport_d *d, void *base, size_t size)
{
struct nmctx *ctx = d->ctx;
struct nmport_cleanup_d *clnup = NULL;
if (d->register_done) {
nmctx_ferror(ctx, "%s: cannot set extmem of an already registered port", d->hdr.nr_name);
errno = EINVAL;
return -1;
}
if (d->extmem != NULL) {
nmctx_ferror(ctx, "%s: extmem already in use", d->hdr.nr_name);
errno = EINVAL;
return -1;
}
clnup = (struct nmport_cleanup_d *)nmctx_malloc(ctx, sizeof(*clnup));
if (clnup == NULL) {
nmctx_ferror(ctx, "failed to allocate cleanup descriptor");
errno = ENOMEM;
return -1;
}
d->extmem = nmctx_malloc(ctx, sizeof(*d->extmem));
if (d->extmem == NULL) {
nmctx_ferror(ctx, "%s: cannot allocate extmem option", d->hdr.nr_name);
nmctx_free(ctx, clnup);
errno = ENOMEM;
return -1;
}
memset(d->extmem, 0, sizeof(*d->extmem));
d->extmem->nro_usrptr = (uintptr_t)base;
d->extmem->nro_opt.nro_reqtype = NETMAP_REQ_OPT_EXTMEM;
d->extmem->nro_info.nr_memsize = size;
nmreq_push_option(&d->hdr, &d->extmem->nro_opt);
clnup->cleanup = nmport_extmem_cleanup;
nmport_push_cleanup(d, clnup);
return 0;
}
struct nmport_extmem_from_file_cleanup_d {
struct nmport_cleanup_d up;
void *p;
size_t size;
};
void nmport_extmem_from_file_cleanup(struct nmport_cleanup_d *c,
struct nmport_d *d)
{
(void)d;
struct nmport_extmem_from_file_cleanup_d *cc =
(struct nmport_extmem_from_file_cleanup_d *)c;
munmap(cc->p, cc->size);
}
int
nmport_extmem_from_file(struct nmport_d *d, const char *fname)
{
struct nmctx *ctx = d->ctx;
int fd = -1;
off_t mapsize;
void *p;
struct nmport_extmem_from_file_cleanup_d *clnup = NULL;
clnup = nmctx_malloc(ctx, sizeof(*clnup));
if (clnup == NULL) {
nmctx_ferror(ctx, "cannot allocate cleanup descriptor");
errno = ENOMEM;
goto fail;
}
fd = open(fname, O_RDWR);
if (fd < 0) {
nmctx_ferror(ctx, "cannot open '%s': %s", fname, strerror(errno));
goto fail;
}
mapsize = lseek(fd, 0, SEEK_END);
if (mapsize < 0) {
nmctx_ferror(ctx, "failed to obtain filesize of '%s': %s", fname, strerror(errno));
goto fail;
}
p = mmap(0, mapsize, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
if (p == MAP_FAILED) {
nmctx_ferror(ctx, "cannot mmap '%s': %s", fname, strerror(errno));
goto fail;
}
close(fd);
clnup->p = p;
clnup->size = mapsize;
clnup->up.cleanup = nmport_extmem_from_file_cleanup;
nmport_push_cleanup(d, &clnup->up);
if (nmport_extmem(d, p, mapsize) < 0)
goto fail;
return 0;
fail:
if (fd >= 0)
close(fd);
if (clnup != NULL) {
if (clnup->p != MAP_FAILED)
nmport_pop_cleanup(d);
else
nmctx_free(ctx, clnup);
}
return -1;
}
struct nmreq_pools_info*
nmport_extmem_getinfo(struct nmport_d *d)
{
if (d->extmem == NULL)
return NULL;
return &d->extmem->nro_info;
}
struct nmport_offset_cleanup_d {
struct nmport_cleanup_d up;
struct nmreq_opt_offsets *opt;
};
static void
nmport_offset_cleanup(struct nmport_cleanup_d *c,
struct nmport_d *d)
{
struct nmport_offset_cleanup_d *cc =
(struct nmport_offset_cleanup_d *)c;
nmreq_remove_option(&d->hdr, &cc->opt->nro_opt);
nmctx_free(d->ctx, cc->opt);
}
int
nmport_offset(struct nmport_d *d, uint64_t initial,
uint64_t maxoff, uint64_t bits, uint64_t mingap)
{
struct nmctx *ctx = d->ctx;
struct nmreq_opt_offsets *opt;
struct nmport_offset_cleanup_d *clnup = NULL;
clnup = nmctx_malloc(ctx, sizeof(*clnup));
if (clnup == NULL) {
nmctx_ferror(ctx, "cannot allocate cleanup descriptor");
errno = ENOMEM;
return -1;
}
opt = nmctx_malloc(ctx, sizeof(*opt));
if (opt == NULL) {
nmctx_ferror(ctx, "%s: cannot allocate offset option", d->hdr.nr_name);
nmctx_free(ctx, clnup);
errno = ENOMEM;
return -1;
}
memset(opt, 0, sizeof(*opt));
opt->nro_opt.nro_reqtype = NETMAP_REQ_OPT_OFFSETS;
opt->nro_offset_bits = bits;
opt->nro_initial_offset = initial;
opt->nro_max_offset = maxoff;
opt->nro_min_gap = mingap;
nmreq_push_option(&d->hdr, &opt->nro_opt);
clnup->up.cleanup = nmport_offset_cleanup;
clnup->opt = opt;
nmport_push_cleanup(d, &clnup->up);
return 0;
}
/* head of the list of options */
static struct nmreq_opt_parser *nmport_opt_parsers;
#define NPOPT_PARSER(o) nmport_opt_##o##_parser
#define NPOPT_DESC(o) nmport_opt_##o##_desc
#define NPOPT_NRKEYS(o) (NPOPT_DESC(o).nr_keys)
#define NPOPT_DECL(o, f) \
static int NPOPT_PARSER(o)(struct nmreq_parse_ctx *); \
static struct nmreq_opt_parser NPOPT_DESC(o) = { \
.prefix = #o, \
.parse = NPOPT_PARSER(o), \
.flags = (f), \
.default_key = -1, \
.nr_keys = 0, \
.next = NULL, \
}; \
static void __attribute__((constructor)) \
nmport_opt_##o##_ctor(void) \
{ \
NPOPT_DESC(o).next = nmport_opt_parsers; \
nmport_opt_parsers = &NPOPT_DESC(o); \
}
struct nmport_key_desc {
struct nmreq_opt_parser *option;
const char *key;
unsigned int flags;
int id;
};
static void
nmport_opt_key_ctor(struct nmport_key_desc *k)
{
struct nmreq_opt_parser *o = k->option;
struct nmreq_opt_key *ok;
k->id = o->nr_keys;
ok = &o->keys[k->id];
ok->key = k->key;
ok->id = k->id;
ok->flags = k->flags;
o->nr_keys++;
if (ok->flags & NMREQ_OPTK_DEFAULT)
o->default_key = ok->id;
}
#define NPKEY_DESC(o, k) nmport_opt_##o##_key_##k##_desc
#define NPKEY_ID(o, k) (NPKEY_DESC(o, k).id)
#define NPKEY_DECL(o, k, f) \
static struct nmport_key_desc NPKEY_DESC(o, k) = { \
.option = &NPOPT_DESC(o), \
.key = #k, \
.flags = (f), \
.id = -1, \
}; \
static void __attribute__((constructor)) \
nmport_opt_##o##_key_##k##_ctor(void) \
{ \
nmport_opt_key_ctor(&NPKEY_DESC(o, k)); \
}
#define nmport_key(p, o, k) ((p)->keys[NPKEY_ID(o, k)])
#define nmport_defkey(p, o) ((p)->keys[NPOPT_DESC(o).default_key])
NPOPT_DECL(share, 0)
NPKEY_DECL(share, port, NMREQ_OPTK_DEFAULT|NMREQ_OPTK_MUSTSET)
NPOPT_DECL(extmem, 0)
NPKEY_DECL(extmem, file, NMREQ_OPTK_DEFAULT|NMREQ_OPTK_MUSTSET)
NPKEY_DECL(extmem, if_num, 0)
NPKEY_DECL(extmem, if_size, 0)
NPKEY_DECL(extmem, ring_num, 0)
NPKEY_DECL(extmem, ring_size, 0)
NPKEY_DECL(extmem, buf_num, 0)
NPKEY_DECL(extmem, buf_size, 0)
NPOPT_DECL(conf, 0)
NPKEY_DECL(conf, rings, 0)
NPKEY_DECL(conf, host_rings, 0)
NPKEY_DECL(conf, slots, 0)
NPKEY_DECL(conf, tx_rings, 0)
NPKEY_DECL(conf, rx_rings, 0)
NPKEY_DECL(conf, host_tx_rings, 0)
NPKEY_DECL(conf, host_rx_rings, 0)
NPKEY_DECL(conf, tx_slots, 0)
NPKEY_DECL(conf, rx_slots, 0)
NPOPT_DECL(offset, NMREQ_OPTF_DISABLED)
NPKEY_DECL(offset, initial, NMREQ_OPTK_DEFAULT|NMREQ_OPTK_MUSTSET)
NPKEY_DECL(offset, bits, 0)
static int
NPOPT_PARSER(share)(struct nmreq_parse_ctx *p)
{
struct nmctx *ctx = p->ctx;
struct nmport_d *d = p->token;
int32_t mem_id;
const char *v = nmport_defkey(p, share);
mem_id = nmreq_get_mem_id(&v, ctx);
if (mem_id < 0)
return -1;
if (d->reg.nr_mem_id && d->reg.nr_mem_id != mem_id) {
nmctx_ferror(ctx, "cannot set mem_id to %"PRId32", already set to %"PRIu16"",
mem_id, d->reg.nr_mem_id);
errno = EINVAL;
return -1;
}
d->reg.nr_mem_id = mem_id;
return 0;
}
static int
NPOPT_PARSER(extmem)(struct nmreq_parse_ctx *p)
{
struct nmport_d *d;
struct nmreq_pools_info *pi;
int i;
d = p->token;
if (nmport_extmem_from_file(d, nmport_key(p, extmem, file)) < 0)
return -1;
pi = &d->extmem->nro_info;
for (i = 0; i < NPOPT_NRKEYS(extmem); i++) {
const char *k = p->keys[i];
uint32_t v;
if (k == NULL)
continue;
v = atoi(k);
if (i == NPKEY_ID(extmem, if_num)) {
pi->nr_if_pool_objtotal = v;
} else if (i == NPKEY_ID(extmem, if_size)) {
pi->nr_if_pool_objsize = v;
} else if (i == NPKEY_ID(extmem, ring_num)) {
pi->nr_ring_pool_objtotal = v;
} else if (i == NPKEY_ID(extmem, ring_size)) {
pi->nr_ring_pool_objsize = v;
} else if (i == NPKEY_ID(extmem, buf_num)) {
pi->nr_buf_pool_objtotal = v;
} else if (i == NPKEY_ID(extmem, buf_size)) {
pi->nr_buf_pool_objsize = v;
}
}
return 0;
}
static int
NPOPT_PARSER(conf)(struct nmreq_parse_ctx *p)
{
struct nmport_d *d;
d = p->token;
if (nmport_key(p, conf, rings) != NULL) {
uint16_t nr_rings = atoi(nmport_key(p, conf, rings));
d->reg.nr_tx_rings = nr_rings;
d->reg.nr_rx_rings = nr_rings;
}
if (nmport_key(p, conf, host_rings) != NULL) {
uint16_t nr_rings = atoi(nmport_key(p, conf, host_rings));
d->reg.nr_host_tx_rings = nr_rings;
d->reg.nr_host_rx_rings = nr_rings;
}
if (nmport_key(p, conf, slots) != NULL) {
uint32_t nr_slots = atoi(nmport_key(p, conf, slots));
d->reg.nr_tx_slots = nr_slots;
d->reg.nr_rx_slots = nr_slots;
}
if (nmport_key(p, conf, tx_rings) != NULL) {
d->reg.nr_tx_rings = atoi(nmport_key(p, conf, tx_rings));
}
if (nmport_key(p, conf, rx_rings) != NULL) {
d->reg.nr_rx_rings = atoi(nmport_key(p, conf, rx_rings));
}
if (nmport_key(p, conf, host_tx_rings) != NULL) {
d->reg.nr_host_tx_rings = atoi(nmport_key(p, conf, host_tx_rings));
}
if (nmport_key(p, conf, host_rx_rings) != NULL) {
d->reg.nr_host_rx_rings = atoi(nmport_key(p, conf, host_rx_rings));
}
if (nmport_key(p, conf, tx_slots) != NULL) {
d->reg.nr_tx_slots = atoi(nmport_key(p, conf, tx_slots));
}
if (nmport_key(p, conf, rx_slots) != NULL) {
d->reg.nr_rx_slots = atoi(nmport_key(p, conf, rx_slots));
}
return 0;
}
static int
NPOPT_PARSER(offset)(struct nmreq_parse_ctx *p)
{
struct nmport_d *d;
uint64_t initial, bits;
d = p->token;
initial = atoi(nmport_key(p, offset, initial));
bits = 0;
if (nmport_key(p, offset, bits) != NULL)
bits = atoi(nmport_key(p, offset, bits));
return nmport_offset(d, initial, initial, bits, 0);
}
void
nmport_disable_option(const char *opt)
{
struct nmreq_opt_parser *p;
for (p = nmport_opt_parsers; p != NULL; p = p->next) {
if (!strcmp(p->prefix, opt)) {
p->flags |= NMREQ_OPTF_DISABLED;
}
}
}
int
nmport_enable_option(const char *opt)
{
struct nmreq_opt_parser *p;
for (p = nmport_opt_parsers; p != NULL; p = p->next) {
if (!strcmp(p->prefix, opt)) {
p->flags &= ~NMREQ_OPTF_DISABLED;
return 0;
}
}
errno = EOPNOTSUPP;
return -1;
}
int
nmport_parse(struct nmport_d *d, const char *ifname)
{
const char *scan = ifname;
if (nmreq_header_decode(&scan, &d->hdr, d->ctx) < 0) {
goto err;
}
/* parse the register request */
if (nmreq_register_decode(&scan, &d->reg, d->ctx) < 0) {
goto err;
}
/* parse the options, if any */
if (nmreq_options_decode(scan, nmport_opt_parsers, d, d->ctx) < 0) {
goto err;
}
return 0;
err:
nmport_undo_parse(d);
return -1;
}
void
nmport_undo_parse(struct nmport_d *d)
{
nmport_do_cleanup(d);
memset(&d->reg, 0, sizeof(d->reg));
memset(&d->hdr, 0, sizeof(d->hdr));
}
struct nmport_d *
nmport_prepare(const char *ifname)
{
struct nmport_d *d;
/* allocate a descriptor */
d = nmport_new();
if (d == NULL)
goto err;
/* parse the header */
if (nmport_parse(d, ifname) < 0)
goto err;
return d;
err:
nmport_undo_prepare(d);
return NULL;
}
void
nmport_undo_prepare(struct nmport_d *d)
{
if (d == NULL)
return;
nmport_undo_parse(d);
nmport_delete(d);
}
int
nmport_register(struct nmport_d *d)
{
struct nmctx *ctx = d->ctx;
if (d->register_done) {
errno = EINVAL;
nmctx_ferror(ctx, "%s: already registered", d->hdr.nr_name);
return -1;
}
d->fd = open("/dev/netmap", O_RDWR);
if (d->fd < 0) {
nmctx_ferror(ctx, "/dev/netmap: %s", strerror(errno));
goto err;
}
if (ioctl(d->fd, NIOCCTRL, &d->hdr) < 0) {
struct nmreq_option *o;
int option_errors = 0;
nmreq_foreach_option(&d->hdr, o) {
if (o->nro_status) {
nmctx_ferror(ctx, "%s: option %s: %s",
d->hdr.nr_name,
nmreq_option_name(o->nro_reqtype),
strerror(o->nro_status));
option_errors++;
}
}
if (!option_errors)
nmctx_ferror(ctx, "%s: %s", d->hdr.nr_name, strerror(errno));
goto err;
}
d->register_done = 1;
return 0;
err:
nmport_undo_register(d);
return -1;
}
void
nmport_undo_register(struct nmport_d *d)
{
if (d->fd >= 0)
close(d->fd);
d->fd = -1;
d->register_done = 0;
}
/* lookup the mem_id in the mem-list: do a new mmap() if
* not found, reuse existing otherwise
*/
int
nmport_mmap(struct nmport_d *d)
{
struct nmctx *ctx = d->ctx;
struct nmem_d *m = NULL;
u_int num_tx, num_rx;
unsigned int i;
if (d->mmap_done) {
errno = EINVAL;
nmctx_ferror(ctx, "%s: already mapped", d->hdr.nr_name);
return -1;
}
if (!d->register_done) {
errno = EINVAL;
nmctx_ferror(ctx, "cannot map unregistered port");
return -1;
}
nmctx_lock(ctx);
for (m = ctx->mem_descs; m != NULL; m = m->next)
if (m->mem_id == d->reg.nr_mem_id)
break;
if (m == NULL) {
m = nmctx_malloc(ctx, sizeof(*m));
if (m == NULL) {
nmctx_ferror(ctx, "cannot allocate memory descriptor");
goto err;
}
memset(m, 0, sizeof(*m));
if (d->extmem != NULL) {
m->mem = (void *)((uintptr_t)d->extmem->nro_usrptr);
m->size = d->extmem->nro_info.nr_memsize;
m->is_extmem = 1;
} else {
m->mem = mmap(NULL, d->reg.nr_memsize, PROT_READ|PROT_WRITE,
MAP_SHARED, d->fd, 0);
if (m->mem == MAP_FAILED) {
nmctx_ferror(ctx, "mmap: %s", strerror(errno));
goto err;
}
m->size = d->reg.nr_memsize;
}
m->mem_id = d->reg.nr_mem_id;
m->next = ctx->mem_descs;
if (ctx->mem_descs != NULL)
ctx->mem_descs->prev = m;
ctx->mem_descs = m;
}
m->refcount++;
nmctx_unlock(ctx);
d->mem = m;
d->nifp = NETMAP_IF(m->mem, d->reg.nr_offset);
num_tx = d->reg.nr_tx_rings + d->nifp->ni_host_tx_rings;
for (i = 0; i < num_tx && !d->nifp->ring_ofs[i]; i++)
;
d->cur_tx_ring = d->first_tx_ring = i;
for ( ; i < num_tx && d->nifp->ring_ofs[i]; i++)
;
d->last_tx_ring = i - 1;
num_rx = d->reg.nr_rx_rings + d->nifp->ni_host_rx_rings;
for (i = 0; i < num_rx && !d->nifp->ring_ofs[i + num_tx]; i++)
;
d->cur_rx_ring = d->first_rx_ring = i;
for ( ; i < num_rx && d->nifp->ring_ofs[i + num_tx]; i++)
;
d->last_rx_ring = i - 1;
d->mmap_done = 1;
return 0;
err:
nmctx_unlock(ctx);
nmport_undo_mmap(d);
return -1;
}
void
nmport_undo_mmap(struct nmport_d *d)
{
struct nmem_d *m;
struct nmctx *ctx = d->ctx;
m = d->mem;
if (m == NULL)
return;
nmctx_lock(ctx);
m->refcount--;
if (m->refcount <= 0) {
if (!m->is_extmem && m->mem != MAP_FAILED)
munmap(m->mem, m->size);
/* extract from the list and free */
if (m->next != NULL)
m->next->prev = m->prev;
if (m->prev != NULL)
m->prev->next = m->next;
else
ctx->mem_descs = m->next;
nmctx_free(ctx, m);
d->mem = NULL;
}
nmctx_unlock(ctx);
d->mmap_done = 0;
d->mem = NULL;
d->nifp = NULL;
d->first_tx_ring = 0;
d->last_tx_ring = 0;
d->first_rx_ring = 0;
d->last_rx_ring = 0;
d->cur_tx_ring = 0;
d->cur_rx_ring = 0;
}
int
nmport_open_desc(struct nmport_d *d)
{
if (nmport_register(d) < 0)
goto err;
if (nmport_mmap(d) < 0)
goto err;
return 0;
err:
nmport_undo_open_desc(d);
return -1;
}
void
nmport_undo_open_desc(struct nmport_d *d)
{
nmport_undo_mmap(d);
nmport_undo_register(d);
}
struct nmport_d *
nmport_open(const char *ifname)
{
struct nmport_d *d;
/* prepare the descriptor */
d = nmport_prepare(ifname);
if (d == NULL)
goto err;
/* open netmap and register */
if (nmport_open_desc(d) < 0)
goto err;
return d;
err:
nmport_close(d);
return NULL;
}
void
nmport_close(struct nmport_d *d)
{
if (d == NULL)
return;
nmport_undo_open_desc(d);
nmport_undo_prepare(d);
}
struct nmport_d *
nmport_clone(struct nmport_d *d)
{
struct nmport_d *c;
struct nmctx *ctx;
ctx = d->ctx;
if (d->extmem != NULL && !d->register_done) {
errno = EINVAL;
nmctx_ferror(ctx, "cannot clone unregistered port that is using extmem");
return NULL;
}
c = nmport_new_with_ctx(ctx);
if (c == NULL)
return NULL;
/* copy the output of parse */
c->hdr = d->hdr;
/* redirect the pointer to the body */
c->hdr.nr_body = (uintptr_t)&c->reg;
/* options are not cloned */
c->hdr.nr_options = 0;
c->reg = d->reg; /* this also copies the mem_id */
/* put the new port in an un-registered, unmapped state */
c->fd = -1;
c->nifp = NULL;
c->register_done = 0;
c->mem = NULL;
c->extmem = NULL;
c->mmap_done = 0;
c->first_tx_ring = 0;
c->last_tx_ring = 0;
c->first_rx_ring = 0;
c->last_rx_ring = 0;
c->cur_tx_ring = 0;
c->cur_rx_ring = 0;
return c;
}
int
nmport_inject(struct nmport_d *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 = (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 */
}