/*
* Allocate or resize buffers.
*/
int
bpf_buffer_ioctl_sblen(struct bpf_d *d, u_int *i)
{
u_int size;
caddr_t fbuf, sbuf;
size = *i;
if (size > bpf_maxbufsize)
*i = size = bpf_maxbufsize;
else if (size < BPF_MINBUFSIZE)
*i = size = BPF_MINBUFSIZE;
/* Allocate buffers immediately */
fbuf = (caddr_t)malloc(size, M_BPF, M_WAITOK);
sbuf = (caddr_t)malloc(size, M_BPF, M_WAITOK);
BPFD_LOCK(d);
if (d->bd_bif != NULL) {
/* Interface already attached, unable to change buffers */
BPFD_UNLOCK(d);
free(fbuf, M_BPF);
free(sbuf, M_BPF);
return (EINVAL);
}
while (d->bd_hbuf_in_use)
mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock,
PRINET, "bd_hbuf", 0);
/* Free old buffers if set */
if (d->bd_fbuf != NULL)
free(d->bd_fbuf, M_BPF);
if (d->bd_sbuf != NULL)
free(d->bd_sbuf, M_BPF);
/* Fill in new data */
d->bd_bufsize = size;
d->bd_fbuf = fbuf;
d->bd_sbuf = sbuf;
d->bd_hbuf = NULL;
d->bd_slen = 0;
d->bd_hlen = 0;
BPFD_UNLOCK(d);
return (0);
}
/*
* Allocate or resize buffers.
*/
int
bpf_buffer_ioctl_sblen(struct bpf_d *d, u_int *i)
{
u_int size;
BPFD_LOCK(d);
if (d->bd_bif != NULL) {
BPFD_UNLOCK(d);
return (EINVAL);
}
size = *i;
if (size > bpf_maxbufsize)
*i = size = bpf_maxbufsize;
else if (size < BPF_MINBUFSIZE)
*i = size = BPF_MINBUFSIZE;
d->bd_bufsize = size;
BPFD_UNLOCK(d);
return (0);
}
/*
* Ioctl to force rotation of the two buffers, if there's any data available.
* This can be used by user space to implement timeouts when waiting for a
* buffer to fill.
*/
int
bpf_zerocopy_ioctl_rotzbuf(struct thread *td, struct bpf_d *d,
struct bpf_zbuf *bz)
{
struct zbuf *bzh;
bzero(bz, sizeof(*bz));
BPFD_LOCK(d);
if (d->bd_hbuf == NULL && d->bd_slen != 0) {
ROTATE_BUFFERS(d);
bzh = (struct zbuf *)d->bd_hbuf;
bz->bz_bufa = (void *)bzh->zb_uaddr;
bz->bz_buflen = d->bd_hlen;
}
BPFD_UNLOCK(d);
return (0);
}
/*
* Ioctl to configure zero-copy buffers -- may be done only once.
*/
int
bpf_zerocopy_ioctl_setzbuf(struct thread *td, struct bpf_d *d,
struct bpf_zbuf *bz)
{
struct zbuf *zba, *zbb;
int error;
KASSERT(d->bd_bufmode == BPF_BUFMODE_ZBUF,
("bpf_zerocopy_ioctl_setzbuf: not in zbuf mode"));
/*
* Must set both buffers. Cannot clear them.
*/
if (bz->bz_bufa == NULL || bz->bz_bufb == NULL)
return (EINVAL);
/*
* Buffers must have a size greater than 0. Alignment and other size
* validity checking is done in zbuf_setup().
*/
if (bz->bz_buflen == 0)
return (EINVAL);
/*
* Allocate new buffers.
*/
error = zbuf_setup(td, (vm_offset_t)bz->bz_bufa, bz->bz_buflen,
&zba);
if (error)
return (error);
error = zbuf_setup(td, (vm_offset_t)bz->bz_bufb, bz->bz_buflen,
&zbb);
if (error) {
zbuf_free(zba);
return (error);
}
/*
* We only allow buffers to be installed once, so atomically check
* that no buffers are currently installed and install new buffers.
*/
BPFD_LOCK(d);
if (d->bd_hbuf != NULL || d->bd_sbuf != NULL || d->bd_fbuf != NULL ||
d->bd_bif != NULL) {
BPFD_UNLOCK(d);
zbuf_free(zba);
zbuf_free(zbb);
return (EINVAL);
}
/*
* Point BPF descriptor at buffers; initialize sbuf as zba so that
* it is always filled first in the sequence, per bpf(4).
*/
d->bd_fbuf = (caddr_t)zbb;
d->bd_sbuf = (caddr_t)zba;
d->bd_slen = 0;
d->bd_hlen = 0;
/*
* We expose only the space left in the buffer after the size of the
* shared management region.
*/
d->bd_bufsize = bz->bz_buflen - sizeof(struct bpf_zbuf_header);
BPFD_UNLOCK(d);
return (0);
}