// SPDX-License-Identifier: GPL-2.0 /* * The USB Monitor, inspired by Dave Harding's USBMon. * * This is a binary format reader. * * Copyright (C) 2006 Paolo Abeni ([email protected]) * Copyright (C) 2006,2007 Pete Zaitcev ([email protected]) */ #include <linux/kernel.h> #include <linux/sched/signal.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 <linux/time64.h> #include <linux/uaccess.h> #include "usb_mon.h" /* * Defined by USB 2.0 clause 9.3, table 9.2. */ #define SETUP_LEN … /* ioctl macros */ #define MON_IOC_MAGIC … #define MON_IOCQ_URB_LEN … /* #2 used to be MON_IOCX_URB, removed before it got into Linus tree */ #define MON_IOCG_STATS … #define MON_IOCT_RING_SIZE … #define MON_IOCQ_RING_SIZE … #define MON_IOCX_GET … #define MON_IOCX_MFETCH … #define MON_IOCH_MFLUSH … /* #9 was MON_IOCT_SETAPI */ #define MON_IOCX_GETX … #ifdef CONFIG_COMPAT #define MON_IOCX_GET32 … #define MON_IOCX_MFETCH32 … #define MON_IOCX_GETX32 … #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 … #define CHUNK_ALIGN(x) … /* * 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 … #define BUFF_DFL … #define BUFF_MIN … /* * The per-event API header (2 per URB). * * This structure is seen in userland as defined by the documentation. */ struct mon_bin_hdr { … }; /* * 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 { … }; /* per file statistic */ struct mon_bin_stats { … }; struct mon_bin_get { … }; struct mon_bin_mfetch { … }; #ifdef CONFIG_COMPAT struct mon_bin_get32 { … }; struct mon_bin_mfetch32 { … }; #endif /* Having these two values same prevents wrapping of the mon_bin_hdr */ #define PKT_ALIGN … #define PKT_SIZE … #define PKT_SZ_API0 … #define PKT_SZ_API1 … #define ISODESC_MAX … /* max number of USB bus supported */ #define MON_BIN_MAX_MINOR … /* * The buffer: map of used pages. */ struct mon_pgmap { … }; /* * This gets associated with an open file struct. */ struct mon_reader_bin { … }; static inline struct mon_bin_hdr *MON_OFF2HDR(const struct mon_reader_bin *rp, unsigned int offset) { … } #define MON_RING_EMPTY(rp) … static unsigned char xfer_to_pipe[4] = …; static const 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) { … } /* * 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) { … } /* * 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) { … } /* * 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) { … } /* * 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) { … } /* * 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) { … } static void mon_buff_area_fill(const struct mon_reader_bin *rp, unsigned int offset, unsigned int size) { … } static inline char mon_bin_get_setup(unsigned char *setupb, const struct urb *urb, char ev_type) { … } static unsigned int mon_bin_get_data(const struct mon_reader_bin *rp, unsigned int offset, struct urb *urb, unsigned int length, char *flag) { … } /* * 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) { … } static void mon_bin_get_isodesc(const struct mon_reader_bin *rp, unsigned int offset, struct urb *urb, char ev_type, unsigned int ndesc) { … } static void mon_bin_event(struct mon_reader_bin *rp, struct urb *urb, char ev_type, int status) { … } static void mon_bin_submit(void *data, struct urb *urb) { … } static void mon_bin_complete(void *data, struct urb *urb, int status) { … } static void mon_bin_error(void *data, struct urb *urb, int error) { … } static int mon_bin_open(struct inode *inode, struct file *file) { … } /* * 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) { … } static int mon_bin_release(struct inode *inode, struct file *file) { … } static ssize_t mon_bin_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos) { … } /* * 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) { … } /* * 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) { … } /* * 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) { … } /* */ static long mon_bin_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { … } #ifdef CONFIG_COMPAT static long mon_bin_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { … } #endif /* CONFIG_COMPAT */ static __poll_t mon_bin_poll(struct file *file, struct poll_table_struct *wait) { … } /* * 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) { … } static void mon_bin_vma_close(struct vm_area_struct *vma) { … } /* * Map ring pages to user space. */ static vm_fault_t mon_bin_vma_fault(struct vm_fault *vmf) { … } static const struct vm_operations_struct mon_bin_vm_ops = …; static int mon_bin_mmap(struct file *filp, struct vm_area_struct *vma) { … } static const struct file_operations mon_fops_binary = …; 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) { … } int mon_bin_add(struct mon_bus *mbus, const struct usb_bus *ubus) { … } void mon_bin_del(struct mon_bus *mbus) { … } int __init mon_bin_init(void) { … } void mon_bin_exit(void) { … }
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