freebsd-skq/sys/dev/usb/usb_pf.c
Hans Petter Selasky 22ef3de712 Fix race in USB PF which can happen if we stop tracing exactly when
the kernel is tapping an USB transfer. This leads to a NULL pointer
access. The solution is to only trace while the USB bus lock is
locked.

MFC after:	2 weeks
2015-08-15 09:00:36 +00:00

533 lines
13 KiB
C

/* $FreeBSD$ */
/*-
* Copyright (c) 1990, 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from the Stanford/CMU enet packet filter,
* (net/enet.c) distributed as part of 4.3BSD, and code contributed
* to Berkeley by Steven McCanne and Van Jacobson both of Lawrence
* Berkeley Laboratory.
*
* 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.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*/
#ifdef USB_GLOBAL_INCLUDE_FILE
#include USB_GLOBAL_INCLUDE_FILE
#else
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/bus.h>
#include <sys/fcntl.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_types.h>
#include <net/if_clone.h>
#include <net/bpf.h>
#include <sys/sysctl.h>
#include <net/route.h>
#include <dev/usb/usb.h>
#include <dev/usb/usbdi.h>
#include <dev/usb/usb_busdma.h>
#include <dev/usb/usb_controller.h>
#include <dev/usb/usb_core.h>
#include <dev/usb/usb_process.h>
#include <dev/usb/usb_device.h>
#include <dev/usb/usb_bus.h>
#include <dev/usb/usb_pf.h>
#include <dev/usb/usb_transfer.h>
#endif /* USB_GLOBAL_INCLUDE_FILE */
static void usbpf_init(void *);
static void usbpf_uninit(void *);
static int usbpf_ioctl(struct ifnet *, u_long, caddr_t);
static int usbpf_clone_match(struct if_clone *, const char *);
static int usbpf_clone_create(struct if_clone *, char *, size_t, caddr_t);
static int usbpf_clone_destroy(struct if_clone *, struct ifnet *);
static struct usb_bus *usbpf_ifname2ubus(const char *);
static uint32_t usbpf_aggregate_xferflags(struct usb_xfer_flags *);
static uint32_t usbpf_aggregate_status(struct usb_xfer_flags_int *);
static int usbpf_xfer_frame_is_read(struct usb_xfer *, uint32_t);
static uint32_t usbpf_xfer_precompute_size(struct usb_xfer *, int);
static struct if_clone *usbpf_cloner;
static const char usbusname[] = "usbus";
SYSINIT(usbpf_init, SI_SUB_PSEUDO, SI_ORDER_MIDDLE, usbpf_init, NULL);
SYSUNINIT(usbpf_uninit, SI_SUB_PSEUDO, SI_ORDER_MIDDLE, usbpf_uninit, NULL);
static void
usbpf_init(void *arg)
{
usbpf_cloner = if_clone_advanced(usbusname, 0, usbpf_clone_match,
usbpf_clone_create, usbpf_clone_destroy);
}
static void
usbpf_uninit(void *arg)
{
int devlcnt;
device_t *devlp;
devclass_t dc;
struct usb_bus *ubus;
int error;
int i;
if_clone_detach(usbpf_cloner);
dc = devclass_find(usbusname);
if (dc == NULL)
return;
error = devclass_get_devices(dc, &devlp, &devlcnt);
if (error)
return;
for (i = 0; i < devlcnt; i++) {
ubus = device_get_softc(devlp[i]);
if (ubus != NULL && ubus->ifp != NULL)
usbpf_clone_destroy(usbpf_cloner, ubus->ifp);
}
free(devlp, M_TEMP);
}
static int
usbpf_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
{
/* No configuration allowed. */
return (EINVAL);
}
static struct usb_bus *
usbpf_ifname2ubus(const char *ifname)
{
device_t dev;
devclass_t dc;
int unit;
int error;
if (strncmp(ifname, usbusname, sizeof(usbusname) - 1) != 0)
return (NULL);
error = ifc_name2unit(ifname, &unit);
if (error || unit < 0)
return (NULL);
dc = devclass_find(usbusname);
if (dc == NULL)
return (NULL);
dev = devclass_get_device(dc, unit);
if (dev == NULL)
return (NULL);
return (device_get_softc(dev));
}
static int
usbpf_clone_match(struct if_clone *ifc, const char *name)
{
struct usb_bus *ubus;
ubus = usbpf_ifname2ubus(name);
if (ubus == NULL)
return (0);
if (ubus->ifp != NULL)
return (0);
return (1);
}
static int
usbpf_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params)
{
int error;
int unit;
struct ifnet *ifp;
struct usb_bus *ubus;
error = ifc_name2unit(name, &unit);
if (error)
return (error);
if (unit < 0)
return (EINVAL);
ubus = usbpf_ifname2ubus(name);
if (ubus == NULL)
return (1);
if (ubus->ifp != NULL)
return (1);
error = ifc_alloc_unit(ifc, &unit);
if (error) {
device_printf(ubus->parent, "usbpf: Could not allocate "
"instance\n");
return (error);
}
ifp = ubus->ifp = if_alloc(IFT_USB);
if (ifp == NULL) {
ifc_free_unit(ifc, unit);
device_printf(ubus->parent, "usbpf: Could not allocate "
"instance\n");
return (ENOSPC);
}
strlcpy(ifp->if_xname, name, sizeof(ifp->if_xname));
ifp->if_softc = ubus;
ifp->if_dname = usbusname;
ifp->if_dunit = unit;
ifp->if_ioctl = usbpf_ioctl;
if_attach(ifp);
ifp->if_flags |= IFF_UP;
rt_ifmsg(ifp);
/*
* XXX According to the specification of DLT_USB, it indicates
* packets beginning with USB setup header. But not sure all
* packets would be.
*/
bpfattach(ifp, DLT_USB, USBPF_HDR_LEN);
return (0);
}
static int
usbpf_clone_destroy(struct if_clone *ifc, struct ifnet *ifp)
{
struct usb_bus *ubus;
int unit;
ubus = ifp->if_softc;
unit = ifp->if_dunit;
/*
* Lock USB before clearing the "ifp" pointer, to avoid
* clearing the pointer in the middle of a TAP operation:
*/
USB_BUS_LOCK(ubus);
ubus->ifp = NULL;
USB_BUS_UNLOCK(ubus);
bpfdetach(ifp);
if_detach(ifp);
if_free(ifp);
ifc_free_unit(ifc, unit);
return (0);
}
void
usbpf_attach(struct usb_bus *ubus)
{
if (bootverbose)
device_printf(ubus->parent, "usbpf: Attached\n");
}
void
usbpf_detach(struct usb_bus *ubus)
{
if (ubus->ifp != NULL)
usbpf_clone_destroy(usbpf_cloner, ubus->ifp);
if (bootverbose)
device_printf(ubus->parent, "usbpf: Detached\n");
}
static uint32_t
usbpf_aggregate_xferflags(struct usb_xfer_flags *flags)
{
uint32_t val = 0;
if (flags->force_short_xfer == 1)
val |= USBPF_FLAG_FORCE_SHORT_XFER;
if (flags->short_xfer_ok == 1)
val |= USBPF_FLAG_SHORT_XFER_OK;
if (flags->short_frames_ok == 1)
val |= USBPF_FLAG_SHORT_FRAMES_OK;
if (flags->pipe_bof == 1)
val |= USBPF_FLAG_PIPE_BOF;
if (flags->proxy_buffer == 1)
val |= USBPF_FLAG_PROXY_BUFFER;
if (flags->ext_buffer == 1)
val |= USBPF_FLAG_EXT_BUFFER;
if (flags->manual_status == 1)
val |= USBPF_FLAG_MANUAL_STATUS;
if (flags->no_pipe_ok == 1)
val |= USBPF_FLAG_NO_PIPE_OK;
if (flags->stall_pipe == 1)
val |= USBPF_FLAG_STALL_PIPE;
return (val);
}
static uint32_t
usbpf_aggregate_status(struct usb_xfer_flags_int *flags)
{
uint32_t val = 0;
if (flags->open == 1)
val |= USBPF_STATUS_OPEN;
if (flags->transferring == 1)
val |= USBPF_STATUS_TRANSFERRING;
if (flags->did_dma_delay == 1)
val |= USBPF_STATUS_DID_DMA_DELAY;
if (flags->did_close == 1)
val |= USBPF_STATUS_DID_CLOSE;
if (flags->draining == 1)
val |= USBPF_STATUS_DRAINING;
if (flags->started == 1)
val |= USBPF_STATUS_STARTED;
if (flags->bandwidth_reclaimed == 1)
val |= USBPF_STATUS_BW_RECLAIMED;
if (flags->control_xfr == 1)
val |= USBPF_STATUS_CONTROL_XFR;
if (flags->control_hdr == 1)
val |= USBPF_STATUS_CONTROL_HDR;
if (flags->control_act == 1)
val |= USBPF_STATUS_CONTROL_ACT;
if (flags->control_stall == 1)
val |= USBPF_STATUS_CONTROL_STALL;
if (flags->short_frames_ok == 1)
val |= USBPF_STATUS_SHORT_FRAMES_OK;
if (flags->short_xfer_ok == 1)
val |= USBPF_STATUS_SHORT_XFER_OK;
#if USB_HAVE_BUSDMA
if (flags->bdma_enable == 1)
val |= USBPF_STATUS_BDMA_ENABLE;
if (flags->bdma_no_post_sync == 1)
val |= USBPF_STATUS_BDMA_NO_POST_SYNC;
if (flags->bdma_setup == 1)
val |= USBPF_STATUS_BDMA_SETUP;
#endif
if (flags->isochronous_xfr == 1)
val |= USBPF_STATUS_ISOCHRONOUS_XFR;
if (flags->curr_dma_set == 1)
val |= USBPF_STATUS_CURR_DMA_SET;
if (flags->can_cancel_immed == 1)
val |= USBPF_STATUS_CAN_CANCEL_IMMED;
if (flags->doing_callback == 1)
val |= USBPF_STATUS_DOING_CALLBACK;
return (val);
}
static int
usbpf_xfer_frame_is_read(struct usb_xfer *xfer, uint32_t frame)
{
int isread;
if ((frame == 0) && (xfer->flags_int.control_xfr != 0) &&
(xfer->flags_int.control_hdr != 0)) {
/* special case */
if (xfer->flags_int.usb_mode == USB_MODE_DEVICE) {
/* The device controller writes to memory */
isread = 1;
} else {
/* The host controller reads from memory */
isread = 0;
}
} else {
isread = USB_GET_DATA_ISREAD(xfer);
}
return (isread);
}
static uint32_t
usbpf_xfer_precompute_size(struct usb_xfer *xfer, int type)
{
uint32_t totlen;
uint32_t x;
uint32_t nframes;
if (type == USBPF_XFERTAP_SUBMIT)
nframes = xfer->nframes;
else
nframes = xfer->aframes;
totlen = USBPF_HDR_LEN + (USBPF_FRAME_HDR_LEN * nframes);
/* precompute all trace lengths */
for (x = 0; x != nframes; x++) {
if (usbpf_xfer_frame_is_read(xfer, x)) {
if (type != USBPF_XFERTAP_SUBMIT) {
totlen += USBPF_FRAME_ALIGN(
xfer->frlengths[x]);
}
} else {
if (type == USBPF_XFERTAP_SUBMIT) {
totlen += USBPF_FRAME_ALIGN(
xfer->frlengths[x]);
}
}
}
return (totlen);
}
void
usbpf_xfertap(struct usb_xfer *xfer, int type)
{
struct usb_bus *bus;
struct usbpf_pkthdr *up;
struct usbpf_framehdr *uf;
usb_frlength_t offset;
uint32_t totlen;
uint32_t frame;
uint32_t temp;
uint32_t nframes;
uint32_t x;
uint8_t *buf;
uint8_t *ptr;
bus = xfer->xroot->bus;
/* sanity checks */
if (bus->ifp == NULL || bus->ifp->if_bpf == NULL)
return;
if (!bpf_peers_present(bus->ifp->if_bpf))
return;
totlen = usbpf_xfer_precompute_size(xfer, type);
if (type == USBPF_XFERTAP_SUBMIT)
nframes = xfer->nframes;
else
nframes = xfer->aframes;
/*
* XXX TODO XXX
*
* When BPF supports it we could pass a fragmented array of
* buffers avoiding the data copy operation here.
*/
buf = ptr = malloc(totlen, M_TEMP, M_NOWAIT);
if (buf == NULL) {
device_printf(bus->parent, "usbpf: Out of memory\n");
return;
}
up = (struct usbpf_pkthdr *)ptr;
ptr += USBPF_HDR_LEN;
/* fill out header */
temp = device_get_unit(bus->bdev);
up->up_totlen = htole32(totlen);
up->up_busunit = htole32(temp);
up->up_address = xfer->xroot->udev->device_index;
if (xfer->flags_int.usb_mode == USB_MODE_DEVICE)
up->up_mode = USBPF_MODE_DEVICE;
else
up->up_mode = USBPF_MODE_HOST;
up->up_type = type;
up->up_xfertype = xfer->endpoint->edesc->bmAttributes & UE_XFERTYPE;
temp = usbpf_aggregate_xferflags(&xfer->flags);
up->up_flags = htole32(temp);
temp = usbpf_aggregate_status(&xfer->flags_int);
up->up_status = htole32(temp);
temp = xfer->error;
up->up_error = htole32(temp);
temp = xfer->interval;
up->up_interval = htole32(temp);
up->up_frames = htole32(nframes);
temp = xfer->max_packet_size;
up->up_packet_size = htole32(temp);
temp = xfer->max_packet_count;
up->up_packet_count = htole32(temp);
temp = xfer->endpointno;
up->up_endpoint = htole32(temp);
up->up_speed = xfer->xroot->udev->speed;
/* clear reserved area */
memset(up->up_reserved, 0, sizeof(up->up_reserved));
/* init offset and frame */
offset = 0;
frame = 0;
/* iterate all the USB frames and copy data, if any */
for (x = 0; x != nframes; x++) {
uint32_t length;
int isread;
/* get length */
length = xfer->frlengths[x];
/* get frame header pointer */
uf = (struct usbpf_framehdr *)ptr;
ptr += USBPF_FRAME_HDR_LEN;
/* fill out packet header */
uf->length = htole32(length);
uf->flags = 0;
/* get information about data read/write */
isread = usbpf_xfer_frame_is_read(xfer, x);
/* check if we need to copy any data */
if (isread) {
if (type == USBPF_XFERTAP_SUBMIT)
length = 0;
else {
uf->flags |= htole32(
USBPF_FRAMEFLAG_DATA_FOLLOWS);
}
} else {
if (type != USBPF_XFERTAP_SUBMIT)
length = 0;
else {
uf->flags |= htole32(
USBPF_FRAMEFLAG_DATA_FOLLOWS);
}
}
/* check if data is read direction */
if (isread)
uf->flags |= htole32(USBPF_FRAMEFLAG_READ);
/* copy USB data, if any */
if (length != 0) {
/* copy data */
usbd_copy_out(&xfer->frbuffers[frame],
offset, ptr, length);
/* align length */
temp = USBPF_FRAME_ALIGN(length);
/* zero pad */
if (temp != length)
memset(ptr + length, 0, temp - length);
ptr += temp;
}
if (xfer->flags_int.isochronous_xfr) {
offset += usbd_xfer_old_frame_length(xfer, x);
} else {
frame ++;
}
}
bpf_tap(bus->ifp->if_bpf, buf, totlen);
free(buf, M_TEMP);
}