/*
* The USB Monitor, inspired by Dave Harding's USBMon.
*
* This is a binary format reader.
*
* Copyright (C) 2006 Paolo Abeni (paolo.abeni@email.it)
* Copyright (C) 2006,2007 Pete Zaitcev (zaitcev@redhat.com)
*/
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <linux/export.h>
#include <linux/usb.h>
#include <linux/poll.h>
#include <linux/compat.h>
#include <linux/mm.h>
#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <asm/uaccess.h>
#include "usb_mon.h"
/*
* Defined by USB 2.0 clause 9.3, table 9.2.
*/
#define SETUP_LEN 8
/* ioctl macros */
#define MON_IOC_MAGIC 0x92
#define MON_IOCQ_URB_LEN _IO(MON_IOC_MAGIC, 1)
/* #2 used to be MON_IOCX_URB, removed before it got into Linus tree */
#define MON_IOCG_STATS _IOR(MON_IOC_MAGIC, 3, struct mon_bin_stats)
#define MON_IOCT_RING_SIZE _IO(MON_IOC_MAGIC, 4)
#define MON_IOCQ_RING_SIZE _IO(MON_IOC_MAGIC, 5)
#define MON_IOCX_GET _IOW(MON_IOC_MAGIC, 6, struct mon_bin_get)
#define MON_IOCX_MFETCH _IOWR(MON_IOC_MAGIC, 7, struct mon_bin_mfetch)
#define MON_IOCH_MFLUSH _IO(MON_IOC_MAGIC, 8)
/* #9 was MON_IOCT_SETAPI */
#define MON_IOCX_GETX _IOW(MON_IOC_MAGIC, 10, struct mon_bin_get)
#ifdef CONFIG_COMPAT
#define MON_IOCX_GET32 _IOW(MON_IOC_MAGIC, 6, struct mon_bin_get32)
#define MON_IOCX_MFETCH32 _IOWR(MON_IOC_MAGIC, 7, struct mon_bin_mfetch32)
#define MON_IOCX_GETX32 _IOW(MON_IOC_MAGIC, 10, struct mon_bin_get32)
#endif
/*
* Some architectures have enormous basic pages (16KB for ia64, 64KB for ppc).
* But it's all right. Just use a simple way to make sure the chunk is never
* smaller than a page.
*
* N.B. An application does not know our chunk size.
*
* Woops, get_zeroed_page() returns a single page. I guess we're stuck with
* page-sized chunks for the time being.
*/
#define CHUNK_SIZE PAGE_SIZE
#define CHUNK_ALIGN(x) (((x)+CHUNK_SIZE-1) & ~(CHUNK_SIZE-1))
/*
* The magic limit was calculated so that it allows the monitoring
* application to pick data once in two ticks. This way, another application,
* which presumably drives the bus, gets to hog CPU, yet we collect our data.
* If HZ is 100, a 480 mbit/s bus drives 614 KB every jiffy. USB has an
* enormous overhead built into the bus protocol, so we need about 1000 KB.
*
* This is still too much for most cases, where we just snoop a few
* descriptor fetches for enumeration. So, the default is a "reasonable"
* amount for systems with HZ=250 and incomplete bus saturation.
*
* XXX What about multi-megabyte URBs which take minutes to transfer?
*/
#define BUFF_MAX CHUNK_ALIGN(1200*1024)
#define BUFF_DFL CHUNK_ALIGN(300*1024)
#define BUFF_MIN CHUNK_ALIGN(8*1024)
/*
* The per-event API header (2 per URB).
*
* This structure is seen in userland as defined by the documentation.
*/
struct mon_bin_hdr {
u64 id; /* URB ID - from submission to callback */
unsigned char type; /* Same as in text API; extensible. */
unsigned char xfer_type; /* ISO, Intr, Control, Bulk */
unsigned char epnum; /* Endpoint number and transfer direction */
unsigned char devnum; /* Device address */
unsigned short busnum; /* Bus number */
char flag_setup;
char flag_data;
s64 ts_sec; /* gettimeofday */
s32 ts_usec; /* gettimeofday */
int status;
unsigned int len_urb; /* Length of data (submitted or actual) */
unsigned int len_cap; /* Delivered length */
union {
unsigned char setup[SETUP_LEN]; /* Only for Control S-type */
struct iso_rec {
int error_count;
int numdesc;
} iso;
} s;
int interval;
int start_frame;
unsigned int xfer_flags;
unsigned int ndesc; /* Actual number of ISO descriptors */
};
/*
* ISO vector, packed into the head of data stream.
* This has to take 16 bytes to make sure that the end of buffer
* wrap is not happening in the middle of a descriptor.
*/
struct mon_bin_isodesc {
int iso_status;
unsigned int iso_off;
unsigned int iso_len;
u32 _pad;
};
/* per file statistic */
struct mon_bin_stats {
u32 queued;
u32 dropped;
};
struct mon_bin_get {
struct mon_bin_hdr __user *hdr; /* Can be 48 bytes or 64. */
void __user *data;
size_t alloc; /* Length of data (can be zero) */
};
struct mon_bin_mfetch {
u32 __user *offvec; /* Vector of events fetched */
u32 nfetch; /* Number of events to fetch (out: fetched) */
u32 nflush; /* Number of events to flush */
};
#ifdef CONFIG_COMPAT
struct mon_bin_get32 {
u32 hdr32;
u32 data32;
u32 alloc32;
};
struct mon_bin_mfetch32 {
u32 offvec32;
u32 nfetch32;
u32 nflush32;
};
#endif
/* Having these two values same prevents wrapping of the mon_bin_hdr */
#define PKT_ALIGN 64
#define PKT_SIZE 64
#define PKT_SZ_API0 48 /* API 0 (2.6.20) size */
#define PKT_SZ_API1 64 /* API 1 size: extra fields */
#define ISODESC_MAX 128 /* Same number as usbfs allows, 2048 bytes. */
/* max number of USB bus supported */
#define MON_BIN_MAX_MINOR 128
/*
* The buffer: map of used pages.
*/
struct mon_pgmap {
struct page *pg;
unsigned char *ptr; /* XXX just use page_to_virt everywhere? */
};
/*
* This gets associated with an open file struct.
*/
struct mon_reader_bin {
/* The buffer: one per open. */
spinlock_t b_lock; /* Protect b_cnt, b_in */
unsigned int b_size; /* Current size of the buffer - bytes */
unsigned int b_cnt; /* Bytes used */
unsigned int b_in, b_out; /* Offsets into buffer - bytes */
unsigned int b_read; /* Amount of read data in curr. pkt. */
struct mon_pgmap *b_vec; /* The map array */
wait_queue_head_t b_wait; /* Wait for data here */
struct mutex fetch_lock; /* Protect b_read, b_out */
int mmap_active;
/* A list of these is needed for "bus 0". Some time later. */
struct mon_reader r;
/* Stats */
unsigned int cnt_lost;
};
static inline struct mon_bin_hdr *MON_OFF2HDR(const struct mon_reader_bin *rp,
unsigned int offset)
{
return (struct mon_bin_hdr *)
(rp->b_vec[offset / CHUNK_SIZE].ptr + offset % CHUNK_SIZE);
}
#define MON_RING_EMPTY(rp) ((rp)->b_cnt == 0)
static unsigned char xfer_to_pipe[4] = {
PIPE_CONTROL, PIPE_ISOCHRONOUS, PIPE_BULK, PIPE_INTERRUPT
};
static struct class *mon_bin_class;
static dev_t mon_bin_dev0;
static struct cdev mon_bin_cdev;
static void mon_buff_area_fill(const struct mon_reader_bin *rp,
unsigned int offset, unsigned int size);
static int mon_bin_wait_event(struct file *file, struct mon_reader_bin *rp);
static int mon_alloc_buff(struct mon_pgmap *map, int npages);
static void mon_free_buff(struct mon_pgmap *map, int npages);
/*
* This is a "chunked memcpy". It does not manipulate any counters.
*/
static unsigned int mon_copy_to_buff(const struct mon_reader_bin *this,
unsigned int off, const unsigned char *from, unsigned int length)
{
unsigned int step_len;
unsigned char *buf;
unsigned int in_page;
while (length) {
/*
* Determine step_len.
*/
step_len = length;
in_page = CHUNK_SIZE - (off & (CHUNK_SIZE-1));
if (in_page < step_len)
step_len = in_page;
/*
* Copy data and advance pointers.
*/
buf = this->b_vec[off / CHUNK_SIZE].ptr + off % CHUNK_SIZE;
memcpy(buf, from, step_len);
if ((off += step_len) >= this->b_size) off = 0;
from += step_len;
length -= step_len;
}
return off;
}
/*
* This is a little worse than the above because it's "chunked copy_to_user".
* The return value is an error code, not an offset.
*/
static int copy_from_buf(const struct mon_reader_bin *this, unsigned int off,
char __user *to, int length)
{
unsigned int step_len;
unsigned char *buf;
unsigned int in_page;
while (length) {
/*
* Determine step_len.
*/
step_len = length;
in_page = CHUNK_SIZE - (off & (CHUNK_SIZE-1));
if (in_page < step_len)
step_len = in_page;
/*
* Copy data and advance pointers.
*/
buf = this->b_vec[off / CHUNK_SIZE].ptr + off % CHUNK_SIZE;
if (copy_to_user(to, buf, step_len))
return -EINVAL;
if ((off += step_len) >= this->b_size) off = 0;
to += step_len;
length -= step_len;
}
return 0;
}
/*
* Allocate an (aligned) area in the buffer.
* This is called under b_lock.
* Returns ~0 on failure.
*/
static unsigned int mon_buff_area_alloc(struct mon_reader_bin *rp,
unsigned int size)
{
unsigned int offset;
size = (size + PKT_ALIGN-1) & ~(PKT_ALIGN-1);
if (rp->b_cnt + size > rp->b_size)
return ~0;
offset = rp->b_in;
rp->b_cnt += size;
if ((rp->b_in += size) >= rp->b_size)
rp->b_in -= rp->b_size;
return offset;
}
/*
* This is the same thing as mon_buff_area_alloc, only it does not allow
* buffers to wrap. This is needed by applications which pass references
* into mmap-ed buffers up their stacks (libpcap can do that).
*
* Currently, we always have the header stuck with the data, although
* it is not strictly speaking necessary.
*
* When a buffer would wrap, we place a filler packet to mark the space.
*/
static unsigned int mon_buff_area_alloc_contiguous(struct mon_reader_bin *rp,
unsigned int size)
{
unsigned int offset;
unsigned int fill_size;
size = (size + PKT_ALIGN-1) & ~(PKT_ALIGN-1);
if (rp->b_cnt + size > rp->b_size)
return ~0;
if (rp->b_in + size > rp->b_size) {
/*
* This would wrap. Find if we still have space after
* skipping to the end of the buffer. If we do, place
* a filler packet and allocate a new packet.
*/
fill_size = rp->b_size - rp->b_in;
if (rp->b_cnt + size + fill_size > rp->b_size)
return ~0;
mon_buff_area_fill(rp, rp->b_in, fill_size);
offset = 0;
rp->b_in = size;
rp->b_cnt += size + fill_size;
} else if (rp->b_in + size == rp->b_size) {
offset = rp->b_in;
rp->b_in = 0;
rp->b_cnt += size;
} else {
offset = rp->b_in;
rp->b_in += size;
rp->b_cnt += size;
}
return offset;
}
/*
* Return a few (kilo-)bytes to the head of the buffer.
* This is used if a data fetch fails.
*/
static void mon_buff_area_shrink(struct mon_reader_bin *rp, unsigned int size)
{
/* size &= ~(PKT_ALIGN-1); -- we're called with aligned size */
rp->b_cnt -= size;
if (rp->b_in < size)
rp->b_in += rp->b_size;
rp->b_in -= size;
}
/*
* This has to be called under both b_lock and fetch_lock, because
* it accesses both b_cnt and b_out.
*/
static void mon_buff_area_free(struct mon_reader_bin *rp, unsigned int size)
{
size = (size + PKT_ALIGN-1) & ~(PKT_ALIGN-1);
rp->b_cnt -= size;
if ((rp->b_out += size) >= rp->b_size)
rp->b_out -= rp->b_size;
}
static void mon_buff_area_fill(const struct mon_reader_bin *rp,
unsigned int offset, unsigned int size)
{
struct mon_bin_hdr *ep;
ep = MON_OFF2HDR(rp, offset);
memset(ep, 0, PKT_SIZE);
ep->type = '@';
ep->len_cap = size - PKT_SIZE;
}
static inline char mon_bin_get_setup(unsigned char *setupb,
const struct urb *urb, char ev_type)
{
if (urb->setup_packet == NULL)
return 'Z';
memcpy(setupb, urb->setup_packet, SETUP_LEN);
return 0;
}
static unsigned int mon_bin_get_data(const struct mon_reader_bin *rp,
unsigned int offset, struct urb *urb, unsigned int length,
char *flag)
{
int i;
struct scatterlist *sg;
unsigned int this_len;
*flag = 0;
if (urb->num_sgs == 0) {
if (urb->transfer_buffer == NULL) {
*flag = 'Z';
return length;
}
mon_copy_to_buff(rp, offset, urb->transfer_buffer, length);
length = 0;
} else {
/* If IOMMU coalescing occurred, we cannot trust sg_page */
if (urb->transfer_flags & URB_DMA_SG_COMBINED) {
*flag = 'D';
return length;
}
/* Copy up to the first non-addressable segment */
for_each_sg(urb->sg, sg, urb->num_sgs, i) {
if (length == 0 || PageHighMem(sg_page(sg)))
break;
this_len = min_t(unsigned int, sg->length, length);
offset = mon_copy_to_buff(rp, offset, sg_virt(sg),
this_len);
length -= this_len;
}
if (i == 0)
*flag = 'D';
}
return length;
}
/*
* This is the look-ahead pass in case of 'C Zi', when actual_length cannot
* be used to determine the length of the whole contiguous buffer.
*/
static unsigned int mon_bin_collate_isodesc(const struct mon_reader_bin *rp,
struct urb *urb, unsigned int ndesc)
{
struct usb_iso_packet_descriptor *fp;
unsigned int length;
length = 0;
fp = urb->iso_frame_desc;
while (ndesc-- != 0) {
if (fp->actual_length != 0) {
if (fp->offset + fp->actual_length > length)
length = fp->offset + fp->actual_length;
}
fp++;
}
return length;
}
static void mon_bin_get_isodesc(const struct mon_reader_bin *rp,
unsigned int offset, struct urb *urb, char ev_type, unsigned int ndesc)
{
struct mon_bin_isodesc *dp;
struct usb_iso_packet_descriptor *fp;
fp = urb->iso_frame_desc;
while (ndesc-- != 0) {
dp = (struct mon_bin_isodesc *)
(rp->b_vec[offset / CHUNK_SIZE].ptr + offset % CHUNK_SIZE);
dp->iso_status = fp->status;
dp->iso_off = fp->offset;
dp->iso_len = (ev_type == 'S') ? fp->length : fp->actual_length;
dp->_pad = 0;
if ((offset += sizeof(struct mon_bin_isodesc)) >= rp->b_size)
offset = 0;
fp++;
}
}
static void mon_bin_event(struct mon_reader_bin *rp, struct urb *urb,
char ev_type, int status)
{
const struct usb_endpoint_descriptor *epd = &urb->ep->desc;
struct timeval ts;
unsigned long flags;
unsigned int urb_length;
unsigned int offset;
unsigned int length;
unsigned int delta;
unsigned int ndesc, lendesc;
unsigned char dir;
struct mon_bin_hdr *ep;
char data_tag = 0;
do_gettimeofday(&ts);
spin_lock_irqsave(&rp->b_lock, flags);
/*
* Find the maximum allowable length, then allocate space.
*/
urb_length = (ev_type == 'S') ?
urb->transfer_buffer_length : urb->actual_length;
length = urb_length;
if (usb_endpoint_xfer_isoc(epd)) {
if (urb->number_of_packets < 0) {
ndesc = 0;
} else if (urb->number_of_packets >= ISODESC_MAX) {
ndesc = ISODESC_MAX;
} else {
ndesc = urb->number_of_packets;
}
if (ev_type == 'C' && usb_urb_dir_in(urb))
length = mon_bin_collate_isodesc(rp, urb, ndesc);
} else {
ndesc = 0;
}
lendesc = ndesc*sizeof(struct mon_bin_isodesc);
/* not an issue unless there's a subtle bug in a HCD somewhere */
if (length >= urb->transfer_buffer_length)
length = urb->transfer_buffer_length;
if (length >= rp->b_size/5)
length = rp->b_size/5;
if (usb_urb_dir_in(urb)) {
if (ev_type == 'S') {
length = 0;
data_tag = '<';
}
/* Cannot rely on endpoint number in case of control ep.0 */
dir = USB_DIR_IN;
} else {
if (ev_type == 'C') {
length = 0;
data_tag = '>';
}
dir = 0;
}
if (rp->mmap_active) {
offset = mon_buff_area_alloc_contiguous(rp,
length + PKT_SIZE + lendesc);
} else {
offset = mon_buff_area_alloc(rp, length + PKT_SIZE + lendesc);
}
if (offset == ~0) {
rp->cnt_lost++;
spin_unlock_irqrestore(&rp->b_lock, flags);
return;
}
ep = MON_OFF2HDR(rp, offset);
if ((offset += PKT_SIZE) >= rp->b_size) offset = 0;
/*
* Fill the allocated area.
*/
memset(ep, 0, PKT_SIZE);
ep->type = ev_type;
ep->xfer_type = xfer_to_pipe[usb_endpoint_type(epd)];
ep->epnum = dir | usb_endpoint_num(epd);
ep->devnum = urb->dev->devnum;
ep->busnum = urb->dev->bus->busnum;
ep->id = (unsigned long) urb;
ep->ts_sec = ts.tv_sec;
ep->ts_usec = ts.tv_usec;
ep->status = status;
ep->len_urb = urb_length;
ep->len_cap = length + lendesc;
ep->xfer_flags = urb->transfer_flags;
if (usb_endpoint_xfer_int(epd)) {
ep->interval = urb->interval;
} else if (usb_endpoint_xfer_isoc(epd)) {
ep->interval = urb->interval;
ep->start_frame = urb->start_frame;
ep->s.iso.error_count = urb->error_count;
ep->s.iso.numdesc = urb->number_of_packets;
}
if (usb_endpoint_xfer_control(epd) && ev_type == 'S') {
ep->flag_setup = mon_bin_get_setup(ep->s.setup, urb, ev_type);
} else {
ep->flag_setup = '-';
}
if (ndesc != 0) {
ep->ndesc = ndesc;
mon_bin_get_isodesc(rp, offset, urb, ev_type, ndesc);
if ((offset += lendesc) >= rp->b_size)
offset -= rp->b_size;
}
if (length != 0) {
length = mon_bin_get_data(rp, offset, urb, length,
&ep->flag_data);
if (length > 0) {
delta = (ep->len_cap + PKT_ALIGN-1) & ~(PKT_ALIGN-1);
ep->len_cap -= length;
delta -= (ep->len_cap + PKT_ALIGN-1) & ~(PKT_ALIGN-1);
mon_buff_area_shrink(rp, delta);
}
} else {
ep->flag_data = data_tag;
}
spin_unlock_irqrestore(&rp->b_lock, flags);
wake_up(&rp->b_wait);
}
static void mon_bin_submit(void *data, struct urb *urb)
{
struct mon_reader_bin *rp = data;
mon_bin_event(rp, urb, 'S', -EINPROGRESS);
}
static void mon_bin_complete(void *data, struct urb *urb, int status)
{
struct mon_reader_bin *rp = data;
mon_bin_event(rp, urb, 'C', status);
}
static void mon_bin_error(void *data, struct urb *urb, int error)
{
struct mon_reader_bin *rp = data;
struct timeval ts;
unsigned long flags;
unsigned int offset;
struct mon_bin_hdr *ep;
do_gettimeofday(&ts);
spin_lock_irqsave(&rp->b_lock, flags);
offset = mon_buff_area_alloc(rp, PKT_SIZE);
if (offset == ~0) {
/* Not incrementing cnt_lost. Just because. */
spin_unlock_irqrestore(&rp->b_lock, flags);
return;
}
ep = MON_OFF2HDR(rp, offset);
memset(ep, 0, PKT_SIZE);
ep->type = 'E';
ep->xfer_type = xfer_to_pipe[usb_endpoint_type(&urb->ep->desc)];
ep->epnum = usb_urb_dir_in(urb) ? USB_DIR_IN : 0;
ep->epnum |= usb_endpoint_num(&urb->ep->desc);
ep->devnum = urb->dev->devnum;
ep->busnum = urb->dev->bus->busnum;
ep->id = (unsigned long) urb;
ep->ts_sec = ts.tv_sec;
ep->ts_usec = ts.tv_usec;
ep->status = error;
ep->flag_setup = '-';
ep->flag_data = 'E';
spin_unlock_irqrestore(&rp->b_lock, flags);
wake_up(&rp->b_wait);
}
static int mon_bin_open(struct inode *inode, struct file *file)
{
struct mon_bus *mbus;
struct mon_reader_bin *rp;
size_t size;
int rc;
mutex_lock(&mon_lock);
mbus = mon_bus_lookup(iminor(inode));
if (mbus == NULL) {
mutex_unlock(&mon_lock);
return -ENODEV;
}
if (mbus != &mon_bus0 && mbus->u_bus == NULL) {
printk(KERN_ERR TAG ": consistency error on open\n");
mutex_unlock(&mon_lock);
return -ENODEV;
}
rp = kzalloc(sizeof(struct mon_reader_bin), GFP_KERNEL);
if (rp == NULL) {
rc = -ENOMEM;
goto err_alloc;
}
spin_lock_init(&rp->b_lock);
init_waitqueue_head(&rp->b_wait);
mutex_init(&rp->fetch_lock);
rp->b_size = BUFF_DFL;
size = sizeof(struct mon_pgmap) * (rp->b_size/CHUNK_SIZE);
if ((rp->b_vec = kzalloc(size, GFP_KERNEL)) == NULL) {
rc = -ENOMEM;
goto err_allocvec;
}
if ((rc = mon_alloc_buff(rp->b_vec, rp->b_size/CHUNK_SIZE)) < 0)
goto err_allocbuff;
rp->r.m_bus = mbus;
rp->r.r_data = rp;
rp->r.rnf_submit = mon_bin_submit;
rp->r.rnf_error = mon_bin_error;
rp->r.rnf_complete = mon_bin_complete;
mon_reader_add(mbus, &rp->r);
file->private_data = rp;
mutex_unlock(&mon_lock);
return 0;
err_allocbuff:
kfree(rp->b_vec);
err_allocvec:
kfree(rp);
err_alloc:
mutex_unlock(&mon_lock);
return rc;
}
/*
* Extract an event from buffer and copy it to user space.
* Wait if there is no event ready.
* Returns zero or error.
*/
static int mon_bin_get_event(struct file *file, struct mon_reader_bin *rp,
struct mon_bin_hdr __user *hdr, unsigned int hdrbytes,
void __user *data, unsigned int nbytes)
{
unsigned long flags;
struct mon_bin_hdr *ep;
size_t step_len;
unsigned int offset;
int rc;
mutex_lock(&rp->fetch_lock);
if ((rc = mon_bin_wait_event(file, rp)) < 0) {
mutex_unlock(&rp->fetch_lock);
return rc;
}
ep = MON_OFF2HDR(rp, rp->b_out);
if (copy_to_user(hdr, ep, hdrbytes)) {
mutex_unlock(&rp->fetch_lock);
return -EFAULT;
}
step_len = min(ep->len_cap, nbytes);
if ((offset = rp->b_out + PKT_SIZE) >= rp->b_size) offset = 0;
if (copy_from_buf(rp, offset, data, step_len)) {
mutex_unlock(&rp->fetch_lock);
return -EFAULT;
}
spin_lock_irqsave(&rp->b_lock, flags);
mon_buff_area_free(rp, PKT_SIZE + ep->len_cap);
spin_unlock_irqrestore(&rp->b_lock, flags);
rp->b_read = 0;
mutex_unlock(&rp->fetch_lock);
return 0;
}
static int mon_bin_release(struct inode *inode, struct file *file)
{
struct mon_reader_bin *rp = file->private_data;
struct mon_bus* mbus = rp->r.m_bus;
mutex_lock(&mon_lock);
if (mbus->nreaders <= 0) {
printk(KERN_ERR TAG ": consistency error on close\n");
mutex_unlock(&mon_lock);
return 0;
}
mon_reader_del(mbus, &rp->r);
mon_free_buff(rp->b_vec, rp->b_size/CHUNK_SIZE);
kfree(rp->b_vec);
kfree(rp);
mutex_unlock(&mon_lock);
return 0;
}
static ssize_t mon_bin_read(struct file *file, char __user *buf,
size_t nbytes, loff_t *ppos)
{
struct mon_reader_bin *rp = file->private_data;
unsigned int hdrbytes = PKT_SZ_API0;
unsigned long flags;
struct mon_bin_hdr *ep;
unsigned int offset;
size_t step_len;
char *ptr;
ssize_t done = 0;
int rc;
mutex_lock(&rp->fetch_lock);
if ((rc = mon_bin_wait_event(file, rp)) < 0) {
mutex_unlock(&rp->fetch_lock);
return rc;
}
ep = MON_OFF2HDR(rp, rp->b_out);
if (rp->b_read < hdrbytes) {
step_len = min(nbytes, (size_t)(hdrbytes - rp->b_read));
ptr = ((char *)ep) + rp->b_read;
if (step_len && copy_to_user(buf, ptr, step_len)) {
mutex_unlock(&rp->fetch_lock);
return -EFAULT;
}
nbytes -= step_len;
buf += step_len;
rp->b_read += step_len;
done += step_len;
}
if (rp->b_read >= hdrbytes) {
step_len = ep->len_cap;
step_len -= rp->b_read - hdrbytes;
if (step_len > nbytes)
step_len = nbytes;
offset = rp->b_out + PKT_SIZE;
offset += rp->b_read - hdrbytes;
if (offset >= rp->b_size)
offset -= rp->b_size;
if (copy_from_buf(rp, offset, buf, step_len)) {
mutex_unlock(&rp->fetch_lock);
return -EFAULT;
}
nbytes -= step_len;
buf += step_len;
rp->b_read += step_len;
done += step_len;
}
/*
* Check if whole packet was read, and if so, jump to the next one.
*/
if (rp->b_read >= hdrbytes + ep->len_cap) {
spin_lock_irqsave(&rp->b_lock, flags);
mon_buff_area_free(rp, PKT_SIZE + ep->len_cap);
spin_unlock_irqrestore(&rp->b_lock, flags);
rp->b_read = 0;
}
mutex_unlock(&rp->fetch_lock);
return done;
}
/*
* Remove at most nevents from chunked buffer.
* Returns the number of removed events.
*/
static int mon_bin_flush(struct mon_reader_bin *rp, unsigned nevents)
{
unsigned long flags;
struct mon_bin_hdr *ep;
int i;
mutex_lock(&rp->fetch_lock);
spin_lock_irqsave(&rp->b_lock, flags);
for (i = 0; i < nevents; ++i) {
if (MON_RING_EMPTY(rp))
break;
ep = MON_OFF2HDR(rp, rp->b_out);
mon_buff_area_free(rp, PKT_SIZE + ep->len_cap);
}
spin_unlock_irqrestore(&rp->b_lock, flags);
rp->b_read = 0;
mutex_unlock(&rp->fetch_lock);
return i;
}
/*
* Fetch at most max event offsets into the buffer and put them into vec.
* The events are usually freed later with mon_bin_flush.
* Return the effective number of events fetched.
*/
static int mon_bin_fetch(struct file *file, struct mon_reader_bin *rp,
u32 __user *vec, unsigned int max)
{
unsigned int cur_out;
unsigned int bytes, avail;
unsigned int size;
unsigned int nevents;
struct mon_bin_hdr *ep;
unsigned long flags;
int rc;
mutex_lock(&rp->fetch_lock);
if ((rc = mon_bin_wait_event(file, rp)) < 0) {
mutex_unlock(&rp->fetch_lock);
return rc;
}
spin_lock_irqsave(&rp->b_lock, flags);
avail = rp->b_cnt;
spin_unlock_irqrestore(&rp->b_lock, flags);
cur_out = rp->b_out;
nevents = 0;
bytes = 0;
while (bytes < avail) {
if (nevents >= max)
break;
ep = MON_OFF2HDR(rp, cur_out);
if (put_user(cur_out, &vec[nevents])) {
mutex_unlock(&rp->fetch_lock);
return -EFAULT;
}
nevents++;
size = ep->len_cap + PKT_SIZE;
size = (size + PKT_ALIGN-1) & ~(PKT_ALIGN-1);
if ((cur_out += size) >= rp->b_size)
cur_out -= rp->b_size;
bytes += size;
}
mutex_unlock(&rp->fetch_lock);
return nevents;
}
/*
* Count events. This is almost the same as the above mon_bin_fetch,
* only we do not store offsets into user vector, and we have no limit.
*/
static int mon_bin_queued(struct mon_reader_bin *rp)
{
unsigned int cur_out;
unsigned int bytes, avail;
unsigned int size;
unsigned int nevents;
struct mon_bin_hdr *ep;
unsigned long flags;
mutex_lock(&rp->fetch_lock);
spin_lock_irqsave(&rp->b_lock, flags);
avail = rp->b_cnt;
spin_unlock_irqrestore(&rp->b_lock, flags);
cur_out = rp->b_out;
nevents = 0;
bytes = 0;
while (bytes < avail) {
ep = MON_OFF2HDR(rp, cur_out);
nevents++;
size = ep->len_cap + PKT_SIZE;
size = (size + PKT_ALIGN-1) & ~(PKT_ALIGN-1);
if ((cur_out += size) >= rp->b_size)
cur_out -= rp->b_size;
bytes += size;
}
mutex_unlock(&rp->fetch_lock);
return nevents;
}
/*
*/
static long mon_bin_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct mon_reader_bin *rp = file->private_data;
// struct mon_bus* mbus = rp->r.m_bus;
int ret = 0;
struct mon_bin_hdr *ep;
unsigned long flags;
switch (cmd) {
case MON_IOCQ_URB_LEN:
/*
* N.B. This only returns the size of data, without the header.
*/
spin_lock_irqsave(&rp->b_lock, flags);
if (!MON_RING_EMPTY(rp)) {
ep = MON_OFF2HDR(rp, rp->b_out);
ret = ep->len_cap;
}
spin_unlock_irqrestore(&rp->b_lock, flags);
break;
case MON_IOCQ_RING_SIZE:
ret = rp->b_size;
break;
case MON_IOCT_RING_SIZE:
/*
* Changing the buffer size will flush it's contents; the new
* buffer is allocated before releasing the old one to be sure
* the device will stay functional also in case of memory
* pressure.
*/
{
int size;
struct mon_pgmap *vec;
if (arg < BUFF_MIN || arg > BUFF_MAX)
return -EINVAL;
size = CHUNK_ALIGN(arg);
vec = kzalloc(sizeof(struct mon_pgmap) * (size / CHUNK_SIZE), GFP_KERNEL);
if (vec == NULL) {
ret = -ENOMEM;
break;
}
ret = mon_alloc_buff(vec, size/CHUNK_SIZE);
if (ret < 0) {
kfree(vec);
break;
}
mutex_lock(&rp->fetch_lock);
spin_lock_irqsave(&rp->b_lock, flags);
mon_free_buff(rp->b_vec, rp->b_size/CHUNK_SIZE);
kfree(rp->b_vec);
rp->b_vec = vec;
rp->b_size = size;
rp->b_read = rp->b_in = rp->b_out = rp->b_cnt = 0;
rp->cnt_lost = 0;
spin_unlock_irqrestore(&rp->b_lock, flags);
mutex_unlock(&rp->fetch_lock);
}
break;
case MON_IOCH_MFLUSH:
ret = mon_bin_flush(rp, arg);
break;
case MON_IOCX_GET:
case MON_IOCX_GETX:
{
struct mon_bin_get getb;
if (copy_from_user(&getb, (void __user *)arg,
sizeof(struct mon_bin_get)))
return -EFAULT;
if (getb.alloc > 0x10000000) /* Want to cast to u32 */
return -EINVAL;
ret = mon_bin_get_event(file, rp, getb.hdr,
(cmd == MON_IOCX_GET)? PKT_SZ_API0: PKT_SZ_API1,
getb.data, (unsigned int)getb.alloc);
}
break;
case MON_IOCX_MFETCH:
{
struct mon_bin_mfetch mfetch;
struct mon_bin_mfetch __user *uptr;
uptr = (struct mon_bin_mfetch __user *)arg;
if (copy_from_user(&mfetch, uptr, sizeof(mfetch)))
return -EFAULT;
if (mfetch.nflush) {
ret = mon_bin_flush(rp, mfetch.nflush);
if (ret < 0)
return ret;
if (put_user(ret, &uptr->nflush))
return -EFAULT;
}
ret = mon_bin_fetch(file, rp, mfetch.offvec, mfetch.nfetch);
if (ret < 0)
return ret;
if (put_user(ret, &uptr->nfetch))
return -EFAULT;
ret = 0;
}
break;
case MON_IOCG_STATS: {
struct mon_bin_stats __user *sp;
unsigned int nevents;
unsigned int ndropped;
spin_lock_irqsave(&rp->b_lock, flags);
ndropped = rp->cnt_lost;
rp->cnt_lost = 0;
spin_unlock_irqrestore(&rp->b_lock, flags);
nevents = mon_bin_queued(rp);
sp = (struct mon_bin_stats __user *)arg;
if (put_user(ndropped, &sp->dropped))
return -EFAULT;
if (put_user(nevents, &sp->queued))
return -EFAULT;
}
break;
default:
return -ENOTTY;
}
return ret;
}
#ifdef CONFIG_COMPAT
static long mon_bin_compat_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
struct mon_reader_bin *rp = file->private_data;
int ret;
switch (cmd) {
case MON_IOCX_GET32:
case MON_IOCX_GETX32:
{
struct mon_bin_get32 getb;
if (copy_from_user(&getb, (void __user *)arg,
sizeof(struct mon_bin_get32)))
return -EFAULT;
ret = mon_bin_get_event(file, rp, compat_ptr(getb.hdr32),
(cmd == MON_IOCX_GET32)? PKT_SZ_API0: PKT_SZ_API1,
compat_ptr(getb.data32), getb.alloc32);
if (ret < 0)
return ret;
}
return 0;
case MON_IOCX_MFETCH32:
{
struct mon_bin_mfetch32 mfetch;
struct mon_bin_mfetch32 __user *uptr;
uptr = (struct mon_bin_mfetch32 __user *) compat_ptr(arg);
if (copy_from_user(&mfetch, uptr, sizeof(mfetch)))
return -EFAULT;
if (mfetch.nflush32) {
ret = mon_bin_flush(rp, mfetch.nflush32);
if (ret < 0)
return ret;
if (put_user(ret, &uptr->nflush32))
return -EFAULT;
}
ret = mon_bin_fetch(file, rp, compat_ptr(mfetch.offvec32),
mfetch.nfetch32);
if (ret < 0)
return ret;
if (put_user(ret, &uptr->nfetch32))
return -EFAULT;
}
return 0;
case MON_IOCG_STATS:
return mon_bin_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
case MON_IOCQ_URB_LEN:
case MON_IOCQ_RING_SIZE:
case MON_IOCT_RING_SIZE:
case MON_IOCH_MFLUSH:
return mon_bin_ioctl(file, cmd, arg);
default:
;
}
return -ENOTTY;
}
#endif /* CONFIG_COMPAT */
static unsigned int
mon_bin_poll(struct file *file, struct poll_table_struct *wait)
{
struct mon_reader_bin *rp = file->private_data;
unsigned int mask = 0;
unsigned long flags;
if (file->f_mode & FMODE_READ)
poll_wait(file, &rp->b_wait, wait);
spin_lock_irqsave(&rp->b_lock, flags);
if (!MON_RING_EMPTY(rp))
mask |= POLLIN | POLLRDNORM; /* readable */
spin_unlock_irqrestore(&rp->b_lock, flags);
return mask;
}
/*
* open and close: just keep track of how many times the device is
* mapped, to use the proper memory allocation function.
*/
static void mon_bin_vma_open(struct vm_area_struct *vma)
{
struct mon_reader_bin *rp = vma->vm_private_data;
rp->mmap_active++;
}
static void mon_bin_vma_close(struct vm_area_struct *vma)
{
struct mon_reader_bin *rp = vma->vm_private_data;
rp->mmap_active--;
}
/*
* Map ring pages to user space.
*/
static int mon_bin_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
struct mon_reader_bin *rp = vma->vm_private_data;
unsigned long offset, chunk_idx;
struct page *pageptr;
offset = vmf->pgoff << PAGE_SHIFT;
if (offset >= rp->b_size)
return VM_FAULT_SIGBUS;
chunk_idx = offset / CHUNK_SIZE;
pageptr = rp->b_vec[chunk_idx].pg;
get_page(pageptr);
vmf->page = pageptr;
return 0;
}
static const struct vm_operations_struct mon_bin_vm_ops = {
.open = mon_bin_vma_open,
.close = mon_bin_vma_close,
.fault = mon_bin_vma_fault,
};
static int mon_bin_mmap(struct file *filp, struct vm_area_struct *vma)
{
/* don't do anything here: "fault" will set up page table entries */
vma->vm_ops = &mon_bin_vm_ops;
vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
vma->vm_private_data = filp->private_data;
mon_bin_vma_open(vma);
return 0;
}
static const struct file_operations mon_fops_binary = {
.owner = THIS_MODULE,
.open = mon_bin_open,
.llseek = no_llseek,
.read = mon_bin_read,
/* .write = mon_text_write, */
.poll = mon_bin_poll,
.unlocked_ioctl = mon_bin_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = mon_bin_compat_ioctl,
#endif
.release = mon_bin_release,
.mmap = mon_bin_mmap,
};
static int mon_bin_wait_event(struct file *file, struct mon_reader_bin *rp)
{
DECLARE_WAITQUEUE(waita, current);
unsigned long flags;
add_wait_queue(&rp->b_wait, &waita);
set_current_state(TASK_INTERRUPTIBLE);
spin_lock_irqsave(&rp->b_lock, flags);
while (MON_RING_EMPTY(rp)) {
spin_unlock_irqrestore(&rp->b_lock, flags);
if (file->f_flags & O_NONBLOCK) {
set_current_state(TASK_RUNNING);
remove_wait_queue(&rp->b_wait, &waita);
return -EWOULDBLOCK; /* Same as EAGAIN in Linux */
}
schedule();
if (signal_pending(current)) {
remove_wait_queue(&rp->b_wait, &waita);
return -EINTR;
}
set_current_state(TASK_INTERRUPTIBLE);
spin_lock_irqsave(&rp->b_lock, flags);
}
spin_unlock_irqrestore(&rp->b_lock, flags);
set_current_state(TASK_RUNNING);
remove_wait_queue(&rp->b_wait, &waita);
return 0;
}
static int mon_alloc_buff(struct mon_pgmap *map, int npages)
{
int n;
unsigned long vaddr;
for (n = 0; n < npages; n++) {
vaddr = get_zeroed_page(GFP_KERNEL);
if (vaddr == 0) {
while (n-- != 0)
free_page((unsigned long) map[n].ptr);
return -ENOMEM;
}
map[n].ptr = (unsigned char *) vaddr;
map[n].pg = virt_to_page((void *) vaddr);
}
return 0;
}
static void mon_free_buff(struct mon_pgmap *map, int npages)
{
int n;
for (n = 0; n < npages; n++)
free_page((unsigned long) map[n].ptr);
}
int mon_bin_add(struct mon_bus *mbus, const struct usb_bus *ubus)
{
struct device *dev;
unsigned minor = ubus? ubus->busnum: 0;
if (minor >= MON_BIN_MAX_MINOR)
return 0;
dev = device_create(mon_bin_class, ubus ? ubus->controller : NULL,
MKDEV(MAJOR(mon_bin_dev0), minor), NULL,
"usbmon%d", minor);
if (IS_ERR(dev))
return 0;
mbus->classdev = dev;
return 1;
}
void mon_bin_del(struct mon_bus *mbus)
{
device_destroy(mon_bin_class, mbus->classdev->devt);
}
int __init mon_bin_init(void)
{
int rc;
mon_bin_class = class_create(THIS_MODULE, "usbmon");
if (IS_ERR(mon_bin_class)) {
rc = PTR_ERR(mon_bin_class);
goto err_class;
}
rc = alloc_chrdev_region(&mon_bin_dev0, 0, MON_BIN_MAX_MINOR, "usbmon");
if (rc < 0)
goto err_dev;
cdev_init(&mon_bin_cdev, &mon_fops_binary);
mon_bin_cdev.owner = THIS_MODULE;
rc = cdev_add(&mon_bin_cdev, mon_bin_dev0, MON_BIN_MAX_MINOR);
if (rc < 0)
goto err_add;
return 0;
err_add:
unregister_chrdev_region(mon_bin_dev0, MON_BIN_MAX_MINOR);
err_dev:
class_destroy(mon_bin_class);
err_class:
return rc;
}
void mon_bin_exit(void)
{
cdev_del(&mon_bin_cdev);
unregister_chrdev_region(mon_bin_dev0, MON_BIN_MAX_MINOR);
class_destroy(mon_bin_class);
}