int
libnet_open_link(libnet_t *l)
{
struct ifreq ifr;
struct bpf_version bv;
uint v;
#if defined(BIOCGHDRCMPLT) && defined(BIOCSHDRCMPLT) && !(__APPLE__)
uint spoof_eth_src = 1;
#endif
if (l == NULL)
{
return (-1);
}
if (l->device == NULL)
{
snprintf(l->err_buf, LIBNET_ERRBUF_SIZE, "%s(): NULL device",
__func__);
goto bad;
}
l->fd = libnet_bpf_open((char*)l->err_buf);
if (l->fd == -1)
{
goto bad;
}
/*
* Get bpf version.
*/
if (ioctl(l->fd, BIOCVERSION, (caddr_t)&bv) < 0)
{
snprintf(l->err_buf, LIBNET_ERRBUF_SIZE, "%s(): BIOCVERSION: %s",
__func__, strerror(errno));
goto bad;
}
if (bv.bv_major != BPF_MAJOR_VERSION || bv.bv_minor < BPF_MINOR_VERSION)
{
snprintf(l->err_buf, LIBNET_ERRBUF_SIZE,
"%s(): kernel bpf filter out of date", __func__);
goto bad;
}
/*
* Attach network interface to bpf device.
*/
strncpy(ifr.ifr_name, l->device, sizeof(ifr.ifr_name) - 1);
ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = '\0';
if (ioctl(l->fd, BIOCSETIF, (caddr_t)&ifr) == -1)
{
snprintf(l->err_buf, LIBNET_ERRBUF_SIZE, "%s(): BIOCSETIF: (%s): %s",
__func__, l->device, strerror(errno));
goto bad;
}
/*
* Get the data link-layer type.
*/
if (ioctl(l->fd, BIOCGDLT, (caddr_t)&v) == -1)
{
snprintf(l->err_buf, LIBNET_ERRBUF_SIZE, "%s(): BIOCGDLT: %s",
__func__, strerror(errno));
goto bad;
}
/*
* NetBSD and FreeBSD BPF have an ioctl for enabling/disabling
* automatic filling of the link level source address.
*/
#if defined(BIOCGHDRCMPLT) && defined(BIOCSHDRCMPLT) && !(__APPLE__)
if (ioctl(l->fd, BIOCSHDRCMPLT, &spoof_eth_src) == -1)
{
snprintf(l->err_buf, LIBNET_ERRBUF_SIZE, "%s(): BIOCSHDRCMPLT: %s",
__func__, strerror(errno));
goto bad;
}
#endif
/*
* Assign link type and offset.
*/
switch (v)
{
case DLT_SLIP:
l->link_offset = 0x10;
break;
case DLT_RAW:
l->link_offset = 0x0;
break;
case DLT_PPP:
l->link_offset = 0x04;
break;
case DLT_EN10MB:
default:
l->link_offset = 0xe; /* default to ethernet */
break;
}
#if _BSDI_VERSION - 0 >= 199510
switch (v)
{
case DLT_SLIP:
v = DLT_SLIP_BSDOS;
l->link_offset = 0x10;
break;
case DLT_PPP:
v = DLT_PPP_BSDOS;
l->link_offset = 0x04;
break;
}
#endif
l->link_type = v;
return (1);
bad:
if (l->fd > 0)
{
close(l->fd); /* this can fail ok */
}
return (-1);
}
struct libnet_link_int *
libnet_open_link_interface(char *device, char *ebuf)
{
struct ifreq ifr;
struct bpf_version bv;
u_int v;
struct libnet_link_int *l;
l = (struct libnet_link_int *)malloc(sizeof(*l));
if (!l)
{
sprintf(ebuf, "malloc: %s", ll_strerror(errno));
#if (__DEBUG)
libnet_error(LN_ERR_CRITICAL, "bpf libnet_open_link_interface: malloc %s",
ll_strerror(errno));
#endif
return (NULL);
}
memset(l, 0, sizeof(*l));
l->fd = libnet_bpf_open(ebuf);
if (l->fd == -1)
{
goto bad;
}
/*
* Get bpf version.
*/
if (ioctl(l->fd, BIOCVERSION, (caddr_t)&bv) < 0)
{
sprintf(ebuf, "BIOCVERSION: %s", ll_strerror(errno));
goto bad;
}
if (bv.bv_major != BPF_MAJOR_VERSION || bv.bv_minor < BPF_MINOR_VERSION)
{
sprintf(ebuf, "kernel bpf filter out of date");
goto bad;
}
/*
* Attach network interface to bpf device.
*/
strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
if (ioctl(l->fd, BIOCSETIF, (caddr_t)&ifr) == -1)
{
sprintf(ebuf, "%s: %s", device, ll_strerror(errno));
goto bad;
}
/*
* Get the data link layer type.
*/
if (ioctl(l->fd, BIOCGDLT, (caddr_t)&v) == -1)
{
sprintf(ebuf, "BIOCGDLT: %s", ll_strerror(errno));
goto bad;
}
/*
* Assign link type and offset.
*/
switch (v)
{
case DLT_SLIP:
l->linkoffset = 0x10;
break;
case DLT_RAW:
l->linkoffset = 0x0;
break;
case DLT_PPP:
l->linkoffset = 0x04;
break;
case DLT_EN10MB:
default:
l->linkoffset = 0xe; /* default to ethernet */
break;
}
#if _BSDI_VERSION - 0 >= 199510
switch (v)
{
case DLT_SLIP:
v = DLT_SLIP_BSDOS;
l->linkoffset = 0x10;
break;
case DLT_PPP:
v = DLT_PPP_BSDOS;
l->linkoffset = 0x04;
break;
}
#endif
l->linktype = v;
return (l);
bad:
close(l->fd); /* this can fail ok */
free(l);
return (NULL);
}
