root/usr.sbin/usbdump/usbdump.c
/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2010 Weongyo Jeong <weongyo@freebsd.org>
 * All rights reserved.
 *
 * 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,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
 *    redistribution must be conditioned upon including a substantially
 *    similar Disclaimer requirement for further binary redistribution.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR 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 DAMAGES.
 */

#include <sys/param.h>
#include <sys/endian.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/utsname.h>
#include <sys/queue.h>
#include <net/if.h>
#include <net/bpf.h>
#include <dev/usb/usb.h>
#include <dev/usb/usb_pf.h>
#include <dev/usb/usbdi.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <sysexits.h>
#include <err.h>

#define BPF_STORE_JUMP(x,_c,_k,_jt,_jf) do {    \
  (x).code = (_c);                              \
  (x).k = (_k);                                 \
  (x).jt = (_jt);                               \
  (x).jf = (_jf);                               \
} while (0)

#define BPF_STORE_STMT(x,_c,_k) do {            \
  (x).code = (_c);                              \
  (x).k = (_k);                                 \
  (x).jt = 0;                                   \
  (x).jf = 0;                                   \
} while (0)

struct usb_filt {
        STAILQ_ENTRY(usb_filt) entry;
        int unit;
        int endpoint;
};

struct usbcap {
        int             fd;             /* fd for /dev/usbpf */
        uint32_t        bufsize;
        uint8_t         *buffer;

        /* for -w option */
        int             wfd;
        /* for -r option */
        int             rfd;
        /* for -b option */
        int             bfd;
};

struct usbcap_filehdr {
        uint32_t        magic;
#define USBCAP_FILEHDR_MAGIC    0x9a90000e
        uint8_t         major;
        uint8_t         minor;
        uint8_t         reserved[26];
} __packed;

struct header_32 {
        /* capture timestamp */
        uint32_t ts_sec;
        uint32_t ts_usec;
        /* data length and alignment information */
        uint32_t caplen;
        uint32_t datalen;
        uint8_t hdrlen;
        uint8_t align;
} __packed;

static int doexit;
static int pkt_captured;
static int verbose;
static int uf_minor;
static char *i_arg;
static char *r_arg;
static char *w_arg;
static char *b_arg;
static struct usbcap uc;
static const char *errstr_table[USB_ERR_MAX] = {
        [USB_ERR_NORMAL_COMPLETION]     = "0",
        [USB_ERR_PENDING_REQUESTS]      = "PENDING_REQUESTS",
        [USB_ERR_NOT_STARTED]           = "NOT_STARTED",
        [USB_ERR_INVAL]                 = "INVAL",
        [USB_ERR_NOMEM]                 = "NOMEM",
        [USB_ERR_CANCELLED]             = "CANCELLED",
        [USB_ERR_BAD_ADDRESS]           = "BAD_ADDRESS",
        [USB_ERR_BAD_BUFSIZE]           = "BAD_BUFSIZE",
        [USB_ERR_BAD_FLAG]              = "BAD_FLAG",
        [USB_ERR_NO_CALLBACK]           = "NO_CALLBACK",
        [USB_ERR_IN_USE]                = "IN_USE",
        [USB_ERR_NO_ADDR]               = "NO_ADDR",
        [USB_ERR_NO_PIPE]               = "NO_PIPE",
        [USB_ERR_ZERO_NFRAMES]          = "ZERO_NFRAMES",
        [USB_ERR_ZERO_MAXP]             = "ZERO_MAXP",
        [USB_ERR_SET_ADDR_FAILED]       = "SET_ADDR_FAILED",
        [USB_ERR_NO_POWER]              = "NO_POWER",
        [USB_ERR_TOO_DEEP]              = "TOO_DEEP",
        [USB_ERR_IOERROR]               = "IOERROR",
        [USB_ERR_NOT_CONFIGURED]        = "NOT_CONFIGURED",
        [USB_ERR_TIMEOUT]               = "TIMEOUT",
        [USB_ERR_SHORT_XFER]            = "SHORT_XFER",
        [USB_ERR_STALLED]               = "STALLED",
        [USB_ERR_INTERRUPTED]           = "INTERRUPTED",
        [USB_ERR_DMA_LOAD_FAILED]       = "DMA_LOAD_FAILED",
        [USB_ERR_BAD_CONTEXT]           = "BAD_CONTEXT",
        [USB_ERR_NO_ROOT_HUB]           = "NO_ROOT_HUB",
        [USB_ERR_NO_INTR_THREAD]        = "NO_INTR_THREAD",
        [USB_ERR_NOT_LOCKED]            = "NOT_LOCKED",
};

#define USB_XFERTYPE_MAX 4

static const char *xfertype_table[USB_XFERTYPE_MAX] = {
        [UE_CONTROL]                    = "CTRL",
        [UE_ISOCHRONOUS]                = "ISOC",
        [UE_BULK]                       = "BULK",
        [UE_INTERRUPT]                  = "INTR"
};

static const char *speed_table[USB_SPEED_MAX] = {
        [USB_SPEED_FULL] = "FULL",
        [USB_SPEED_HIGH] = "HIGH",
        [USB_SPEED_LOW] = "LOW",
        [USB_SPEED_VARIABLE] = "VARI",
        [USB_SPEED_SUPER] = "SUPER",
};

static STAILQ_HEAD(,usb_filt) usb_filt_head =
    STAILQ_HEAD_INITIALIZER(usb_filt_head);

static void
add_filter(int usb_filt_unit, int usb_filt_ep)
{
        struct usb_filt *puf;

        puf = malloc(sizeof(struct usb_filt));
        if (puf == NULL)
                errx(EX_SOFTWARE, "Out of memory.");

        puf->unit = usb_filt_unit;
        puf->endpoint = usb_filt_ep;

        STAILQ_INSERT_TAIL(&usb_filt_head, puf, entry);
}

static void
make_filter(struct bpf_program *pprog, int snapshot)
{
        struct usb_filt *puf;
        struct bpf_insn *dynamic_insn;
        int len;

        len = 0;

        STAILQ_FOREACH(puf, &usb_filt_head, entry)
                len++;

        dynamic_insn = malloc(((len * 5) + 1) * sizeof(struct bpf_insn));

        if (dynamic_insn == NULL)
                errx(EX_SOFTWARE, "Out of memory.");

        len++;

        if (len == 1) {
                /* accept all packets */

                BPF_STORE_STMT(dynamic_insn[0], BPF_RET | BPF_K, snapshot);

                goto done;
        }

        len = 0;

        STAILQ_FOREACH(puf, &usb_filt_head, entry) {
                const int addr_off = (uintptr_t)&((struct usbpf_pkthdr *)0)->up_address;
                const int addr_ep = (uintptr_t)&((struct usbpf_pkthdr *)0)->up_endpoint;
                
                if (puf->unit != -1) {
                        if (puf->endpoint != -1) {
                                BPF_STORE_STMT(dynamic_insn[len],
                                    BPF_LD | BPF_B | BPF_ABS, addr_off);
                                len++;
                                BPF_STORE_JUMP(dynamic_insn[len],
                                    BPF_JMP | BPF_JEQ | BPF_K, (uint8_t)puf->unit, 0, 3);
                                len++;
                                BPF_STORE_STMT(dynamic_insn[len],
                                    BPF_LD | BPF_W | BPF_ABS, addr_ep);
                                len++;
                                BPF_STORE_JUMP(dynamic_insn[len],
                                    BPF_JMP | BPF_JEQ | BPF_K, htobe32(puf->endpoint), 0, 1);
                                len++;
                        } else {
                                BPF_STORE_STMT(dynamic_insn[len],
                                    BPF_LD | BPF_B | BPF_ABS, addr_off);
                                len++;
                                BPF_STORE_JUMP(dynamic_insn[len],
                                    BPF_JMP | BPF_JEQ | BPF_K, (uint8_t)puf->unit, 0, 1);
                                len++;
                        }
                } else {
                        if (puf->endpoint != -1) {
                                BPF_STORE_STMT(dynamic_insn[len],
                                    BPF_LD | BPF_W | BPF_ABS, addr_ep);
                                len++;
                                BPF_STORE_JUMP(dynamic_insn[len],
                                    BPF_JMP | BPF_JEQ | BPF_K, htobe32(puf->endpoint), 0, 1);
                                len++;
                        }
                }
                BPF_STORE_STMT(dynamic_insn[len],
                    BPF_RET | BPF_K, snapshot);
                len++;
        }

        BPF_STORE_STMT(dynamic_insn[len], BPF_RET | BPF_K, 0);
        len++;

done:
        pprog->bf_len = len;
        pprog->bf_insns = dynamic_insn;
}

static int
match_filter(int unit, int endpoint)
{
        struct usb_filt *puf;

        if (STAILQ_FIRST(&usb_filt_head) == NULL)
                return (1);

        STAILQ_FOREACH(puf, &usb_filt_head, entry) {
                if ((puf->unit == -1 || puf->unit == unit) &&
                    (puf->endpoint == -1 || puf->endpoint == endpoint))
                        return (1);
        }
        return (0);
}

static void
free_filter(struct bpf_program *pprog)
{
        struct usb_filt *puf;

        while ((puf = STAILQ_FIRST(&usb_filt_head)) != NULL) {
                STAILQ_REMOVE_HEAD(&usb_filt_head, entry);
                free(puf);
        }
        free(pprog->bf_insns);
}

static void
handle_sigint(int sig)
{

        (void)sig;
        doexit = 1;
}

#define FLAGS(x, name)  \
        (((x) & USBPF_FLAG_##name) ? #name "|" : "")

#define STATUS(x, name) \
        (((x) & USBPF_STATUS_##name) ? #name "|" : "")

static const char *
usb_errstr(uint32_t error)
{
        if (error >= USB_ERR_MAX || errstr_table[error] == NULL)
                return ("UNKNOWN");
        else
                return (errstr_table[error]);
}

static const char *
usb_speedstr(uint8_t speed)
{
        if (speed >= USB_SPEED_MAX  || speed_table[speed] == NULL)
                return ("UNKNOWN");
        else
                return (speed_table[speed]);
}

static const char *
usb_xferstr(uint8_t type)
{
        if (type >= USB_XFERTYPE_MAX  || xfertype_table[type] == NULL)
                return ("UNKN");
        else
                return (xfertype_table[type]);
}

static void
print_flags(uint32_t flags)
{
        printf(" flags %#x <%s%s%s%s%s%s%s%s%s0>\n",
            flags,
            FLAGS(flags, FORCE_SHORT_XFER),
            FLAGS(flags, SHORT_XFER_OK),
            FLAGS(flags, SHORT_FRAMES_OK),
            FLAGS(flags, PIPE_BOF),
            FLAGS(flags, PROXY_BUFFER),
            FLAGS(flags, EXT_BUFFER),
            FLAGS(flags, MANUAL_STATUS),
            FLAGS(flags, NO_PIPE_OK),
            FLAGS(flags, STALL_PIPE));
}

static void
print_status(uint32_t status)
{
        printf(" status %#x <%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s0>\n",
            status, 
            STATUS(status, OPEN),
            STATUS(status, TRANSFERRING),
            STATUS(status, DID_DMA_DELAY),
            STATUS(status, DID_CLOSE),
            STATUS(status, DRAINING),
            STATUS(status, STARTED),
            STATUS(status, BW_RECLAIMED),
            STATUS(status, CONTROL_XFR),
            STATUS(status, CONTROL_HDR),
            STATUS(status, CONTROL_ACT),
            STATUS(status, CONTROL_STALL),
            STATUS(status, SHORT_FRAMES_OK),
            STATUS(status, SHORT_XFER_OK),
            STATUS(status, BDMA_ENABLE),
            STATUS(status, BDMA_NO_POST_SYNC),
            STATUS(status, BDMA_SETUP),
            STATUS(status, ISOCHRONOUS_XFR),
            STATUS(status, CURR_DMA_SET),
            STATUS(status, CAN_CANCEL_IMMED),
            STATUS(status, DOING_CALLBACK));
}

/*
 * Dump a byte into hex format.
 */
static void
hexbyte(char *buf, uint8_t temp)
{
        uint8_t lo;
        uint8_t hi;

        lo = temp & 0xF;
        hi = temp >> 4;

        if (hi < 10)
                buf[0] = '0' + hi;
        else
                buf[0] = 'A' + hi - 10;

        if (lo < 10)
                buf[1] = '0' + lo;
        else
                buf[1] = 'A' + lo - 10;
}

/*
 * Display a region in traditional hexdump format.
 */
static void
hexdump(const uint8_t *region, uint32_t len)
{
        const uint8_t *line;
        char linebuf[128];
        int i;
        int x;
        int c;

        for (line = region; line < (region + len); line += 16) {

                i = 0;

                linebuf[i] = ' ';
                hexbyte(linebuf + i + 1, ((line - region) >> 8) & 0xFF);
                hexbyte(linebuf + i + 3, (line - region) & 0xFF);
                linebuf[i + 5] = ' ';
                linebuf[i + 6] = ' ';
                i += 7;

                for (x = 0; x < 16; x++) {
                  if ((line + x) < (region + len)) {
                        hexbyte(linebuf + i,
                            *(const u_int8_t *)(line + x));
                  } else {
                          linebuf[i] = '-';
                          linebuf[i + 1] = '-';
                        }
                        linebuf[i + 2] = ' ';
                        if (x == 7) {
                          linebuf[i + 3] = ' ';
                          i += 4;
                        } else {
                          i += 3;
                        }
                }
                linebuf[i] = ' ';
                linebuf[i + 1] = '|';
                i += 2;
                for (x = 0; x < 16; x++) {
                        if ((line + x) < (region + len)) {
                                c = *(const u_int8_t *)(line + x);
                                /* !isprint(c) */
                                if ((c < ' ') || (c > '~'))
                                        c = '.';
                                linebuf[i] = c;
                        } else {
                                linebuf[i] = ' ';
                        }
                        i++;
                }
                linebuf[i] = '|';
                linebuf[i + 1] = 0;
                i += 2;
                puts(linebuf);
        }
}

static void
print_apacket(const struct header_32 *hdr, const uint8_t *ptr, int ptr_len)
{
        struct tm *tm;
        struct usbpf_pkthdr up_temp;
        struct usbpf_pkthdr *up;
        struct timeval tv;
        size_t len;
        uint32_t x;
        char buf[64];

        ptr += USBPF_HDR_LEN;
        ptr_len -= USBPF_HDR_LEN;
        if (ptr_len < 0)
                return;

        /* make sure we don't change the source buffer */
        memcpy(&up_temp, ptr - USBPF_HDR_LEN, sizeof(up_temp));
        up = &up_temp;

        /*
         * A packet from the kernel is based on little endian byte
         * order.
         */
        up->up_totlen = le32toh(up->up_totlen);
        up->up_busunit = le32toh(up->up_busunit);
        up->up_flags = le32toh(up->up_flags);
        up->up_status = le32toh(up->up_status);
        up->up_error = le32toh(up->up_error);
        up->up_interval = le32toh(up->up_interval);
        up->up_frames = le32toh(up->up_frames);
        up->up_packet_size = le32toh(up->up_packet_size);
        up->up_packet_count = le32toh(up->up_packet_count);
        up->up_endpoint = le32toh(up->up_endpoint);

        if (!match_filter(up->up_address, up->up_endpoint))
                return;

        tv.tv_sec = hdr->ts_sec;
        tv.tv_usec = hdr->ts_usec;
        tm = localtime(&tv.tv_sec);

        len = strftime(buf, sizeof(buf), "%H:%M:%S", tm);

        if (verbose >= 0) {
                printf("%.*s.%06ld usbus%d.%d %s-%s-EP=%08x,SPD=%s,NFR=%d,SLEN=%d,IVAL=%d%s%s\n",
                    (int)len, buf, tv.tv_usec,
                    (int)up->up_busunit, (int)up->up_address,
                    (up->up_type == USBPF_XFERTAP_SUBMIT) ? "SUBM" : "DONE",
                    usb_xferstr(up->up_xfertype),
                    (unsigned int)up->up_endpoint,
                    usb_speedstr(up->up_speed),
                    (int)up->up_frames,
                    (int)(up->up_totlen - USBPF_HDR_LEN -
                    (USBPF_FRAME_HDR_LEN * up->up_frames)),
                    (int)up->up_interval,
                    (up->up_type == USBPF_XFERTAP_DONE) ? ",ERR=" : "",
                    (up->up_type == USBPF_XFERTAP_DONE) ?
                    usb_errstr(up->up_error) : "");
        }

        if (verbose >= 1 || b_arg != NULL) {
                for (x = 0; x != up->up_frames; x++) {
                        const struct usbpf_framehdr *uf;
                        uint32_t framelen;
                        uint32_t flags;

                        uf = (const struct usbpf_framehdr *)ptr;
                        ptr += USBPF_FRAME_HDR_LEN;
                        ptr_len -= USBPF_FRAME_HDR_LEN;
                        if (ptr_len < 0)
                                return;

                        framelen = le32toh(uf->length);
                        flags = le32toh(uf->flags);

                        if (verbose >= 1) {
                                printf(" frame[%u] %s %d bytes\n",
                                    (unsigned int)x,
                                    (flags & USBPF_FRAMEFLAG_READ) ? "READ" : "WRITE",
                                    (int)framelen);
                        }

                        if (flags & USBPF_FRAMEFLAG_DATA_FOLLOWS) {

                                int tot_frame_len;

                                tot_frame_len = USBPF_FRAME_ALIGN(framelen);

                                ptr_len -= tot_frame_len;

                                if (tot_frame_len < 0 ||
                                    (int)framelen < 0 || (int)ptr_len < 0)
                                        break;

                                if (b_arg != NULL) {
                                        struct usbcap *p = &uc;
                                        int ret;
                                        ret = write(p->bfd, ptr, framelen);
                                        if (ret != (int)framelen)
                                                err(EXIT_FAILURE, "Could not write binary data");
                                }
                                if (verbose >= 1)
                                        hexdump(ptr, framelen);

                                ptr += tot_frame_len;
                        }
                }
        }
        if (verbose >= 2)
                print_flags(up->up_flags);
        if (verbose >= 3)
                print_status(up->up_status);
}

static void
fix_packets(uint8_t *data, const int datalen)
{
        struct header_32 temp;
        uint8_t *ptr;
        uint8_t *next;
        uint32_t hdrlen;
        uint32_t caplen;

        for (ptr = data; ptr < (data + datalen); ptr = next) {

                const struct bpf_hdr *hdr;

                hdr = (const struct bpf_hdr *)ptr;

                temp.ts_sec = htole32(hdr->bh_tstamp.tv_sec);
                temp.ts_usec = htole32(hdr->bh_tstamp.tv_usec);
                temp.caplen = htole32(hdr->bh_caplen);
                temp.datalen = htole32(hdr->bh_datalen);
                temp.hdrlen = hdr->bh_hdrlen;
                temp.align = BPF_WORDALIGN(1);

                hdrlen = hdr->bh_hdrlen;
                caplen = hdr->bh_caplen;

                if ((hdrlen >= sizeof(temp)) && (hdrlen <= 255) &&
                    ((ptr + hdrlen) <= (data + datalen))) {
                        memcpy(ptr, &temp, sizeof(temp));
                        memset(ptr + sizeof(temp), 0, hdrlen - sizeof(temp));
                } else {
                        err(EXIT_FAILURE, "Invalid header length %d", hdrlen);
                }

                next = ptr + BPF_WORDALIGN(hdrlen + caplen);

                if (next <= ptr)
                        err(EXIT_FAILURE, "Invalid length");
        }
}

static void
print_packets(uint8_t *data, const int datalen)
{
        struct header_32 temp;
        uint8_t *ptr;
        uint8_t *next;

        for (ptr = data; ptr < (data + datalen); ptr = next) {

                const struct header_32 *hdr32;

                hdr32 = (const struct header_32 *)ptr;

                temp.ts_sec = le32toh(hdr32->ts_sec);
                temp.ts_usec = le32toh(hdr32->ts_usec);
                temp.caplen = le32toh(hdr32->caplen);
                temp.datalen = le32toh(hdr32->datalen);
                temp.hdrlen = hdr32->hdrlen;
                temp.align = hdr32->align;

                next = ptr + roundup2(temp.hdrlen + temp.caplen, temp.align);

                if (next <= ptr)
                        err(EXIT_FAILURE, "Invalid length");

                if (verbose >= 0 || r_arg != NULL || b_arg != NULL) {
                        print_apacket(&temp, ptr +
                            temp.hdrlen, temp.caplen);
                }
                pkt_captured++;
        }
}

static void
write_packets(struct usbcap *p, const uint8_t *data, const int datalen)
{
        int len = htole32(datalen);
        int ret;

        ret = write(p->wfd, &len, sizeof(int));
        if (ret != sizeof(int)) {
                err(EXIT_FAILURE, "Could not write length "
                    "field of USB data payload");
        }
        ret = write(p->wfd, data, datalen);
        if (ret != datalen) {
                err(EXIT_FAILURE, "Could not write "
                    "complete USB data payload");
        }
}

static void
read_file(struct usbcap *p)
{
        int datalen;
        int ret;
        uint8_t *data;

        while ((ret = read(p->rfd, &datalen, sizeof(int))) == sizeof(int)) {
                datalen = le32toh(datalen);
                data = malloc(datalen);
                if (data == NULL)
                        errx(EX_SOFTWARE, "Out of memory.");
                ret = read(p->rfd, data, datalen);
                if (ret != datalen) {
                        err(EXIT_FAILURE, "Could not read complete "
                            "USB data payload");
                }
                if (uf_minor == 2)
                        fix_packets(data, datalen);

                print_packets(data, datalen);
                free(data);
        }
}

static void
do_loop(struct usbcap *p)
{
        int cc;

        while (doexit == 0) {
                cc = read(p->fd, (uint8_t *)p->buffer, p->bufsize);
                if (cc < 0) {
                        switch (errno) {
                        case EINTR:
                                break;
                        default:
                                fprintf(stderr, "read: %s\n", strerror(errno));
                                return;
                        }
                        continue;
                }
                if (cc == 0)
                        continue;

                fix_packets(p->buffer, cc);

                if (w_arg != NULL)
                        write_packets(p, p->buffer, cc);
                print_packets(p->buffer, cc);
        }
}

static void
init_rfile(struct usbcap *p)
{
        struct usbcap_filehdr uf;
        int ret;

        p->rfd = open(r_arg, O_RDONLY);
        if (p->rfd < 0) {
                err(EXIT_FAILURE, "Could not open "
                    "'%s' for read", r_arg);
        }
        ret = read(p->rfd, &uf, sizeof(uf));
        if (ret != sizeof(uf)) {
                err(EXIT_FAILURE, "Could not read USB capture "
                    "file header");
        }
        if (le32toh(uf.magic) != USBCAP_FILEHDR_MAGIC) {
                errx(EX_SOFTWARE, "Invalid magic field(0x%08x) "
                    "in USB capture file header.",
                    (unsigned int)le32toh(uf.magic));
        }
        if (uf.major != 0) {
                errx(EX_SOFTWARE, "Invalid major version(%d) "
                    "field in USB capture file header.", (int)uf.major);
        }

        uf_minor = uf.minor;

        if (uf.minor != 3 && uf.minor != 2) {
                errx(EX_SOFTWARE, "Invalid minor version(%d) "
                    "field in USB capture file header.", (int)uf.minor);
        }
}

static void
init_wfile(struct usbcap *p)
{
        struct usbcap_filehdr uf;
        int ret;

        p->wfd = open(w_arg, O_CREAT | O_TRUNC | O_WRONLY, S_IRUSR | S_IWUSR);
        if (p->wfd < 0) {
                err(EXIT_FAILURE, "Could not open "
                    "'%s' for write", w_arg);
        }
        memset(&uf, 0, sizeof(uf));
        uf.magic = htole32(USBCAP_FILEHDR_MAGIC);
        uf.major = 0;
        uf.minor = 3;
        ret = write(p->wfd, (const void *)&uf, sizeof(uf));
        if (ret != sizeof(uf)) {
                err(EXIT_FAILURE, "Could not write "
                    "USB capture header");
        }
}

static void
usage(void)
{

#define FMT "    %-14s %s\n"
        fprintf(stderr, "usage: usbdump [options]\n");
        fprintf(stderr, FMT, "-d [ugen]B", "Listen on bus, B");
        fprintf(stderr, FMT, "-d [ugen]B.D", "Listen on bus, B and device, D");
        fprintf(stderr, FMT, "-d [ugen]B.D.E", "Listen on bus, B, device, D, and endpoint E");
        fprintf(stderr, FMT, "-i <usbusX>", "Listen on this bus interface");
        fprintf(stderr, FMT, "-f <unit[.endpoint]>", "Specify a device and endpoint filter");
        fprintf(stderr, FMT, "-r <file>", "Read the raw packets from file");
        fprintf(stderr, FMT, "-s <snaplen>", "Snapshot bytes from each packet");
        fprintf(stderr, FMT, "-v", "Increase the verbose level");
        fprintf(stderr, FMT, "-b <file>", "Save raw version of all recorded data to file");
        fprintf(stderr, FMT, "-w <file>", "Write the raw packets to file");
        fprintf(stderr, FMT, "-h", "Display summary of command line options");
#undef FMT
        exit(EX_USAGE);
}

int
main(int argc, char *argv[])
{
        struct timeval tv;
        struct bpf_program total_prog;
        struct bpf_stat us;
        struct bpf_version bv;
        struct usbcap *p = &uc;
        struct ifreq ifr;
        long snapshot = 192;
        uint32_t v;
        int fd;
        int o;
        int filt_unit;
        int filt_ep;
        int ifindex;
        const char *optstring;
        char *pp;

        optstring = "b:d:hi:r:s:uvw:f:";
        while ((o = getopt(argc, argv, optstring)) != -1) {
                switch (o) {
                case 'b':
                        b_arg = optarg;
                        break;
                case 'd':
                        pp = optarg;
                        if (pp[0] == 'u' && pp[1] == 'g' && pp[2] == 'e' && pp[3] == 'n')
                                pp += 4;
                        ifindex = strtol(pp, &pp, 10);
                        /* Must be same bus when using -d option. */
                        if (i_arg != NULL) {
                                if (atoi(i_arg + 5) != ifindex)
                                        usage();
                        } else {
                                asprintf(&i_arg, "usbus%d", ifindex);
                        }
                        /* Parse unit and endpoint, if any. */
                        if (pp != NULL) {
                                if (*pp == '.') {
                                        filt_unit = strtol(pp + 1, &pp, 10);
                                        filt_ep = -1;
                                        if (pp != NULL) {
                                                if (*pp == '.') {
                                                        filt_ep = strtol(pp + 1, &pp, 10);
                                                        if (pp != NULL && *pp != 0)
                                                                usage();
                                                } else if (*pp != 0) {
                                                        usage();
                                                }
                                        }
                                        add_filter(filt_unit, filt_ep);
                                } else if (*pp != 0) {
                                        usage();
                                }
                        }
                        break;
                case 'f':
                        filt_unit = strtol(optarg, &pp, 10);
                        filt_ep = -1;
                        if (pp != NULL) {
                                if (*pp == '.') {
                                        filt_ep = strtol(pp + 1, &pp, 10);
                                        if (pp != NULL && *pp != 0)
                                                usage();
                                } else if (*pp != 0) {
                                        usage();
                                }
                        }
                        add_filter(filt_unit, filt_ep);
                        break;
                case 'i':
                        i_arg = optarg;
                        break;
                case 'r':
                        r_arg = optarg;
                        init_rfile(p);
                        break;
                case 's':
                        snapshot = strtol(optarg, &pp, 10);
                        errno = 0;
                        if (pp != NULL && *pp != 0)
                                usage();
                        if (snapshot == 0 && errno == EINVAL)
                                usage();
                        /* snapeshot == 0 is special */
                        if (snapshot == 0)
                                snapshot = -1;
                        break;
                case 'u':
                        setbuf(stdout, NULL);
                        setbuf(stderr, NULL);
                        break;
                case 'v':
                        verbose++;
                        break;
                case 'w':
                        w_arg = optarg;
                        init_wfile(p);
                        break;
                default:
                        usage();
                        /* NOTREACHED */
                }
        }

        if (i_arg == NULL)
                i_arg = "usbus0";

        if (b_arg != NULL) {
                p->bfd = open(b_arg, O_CREAT | O_TRUNC |
                    O_WRONLY, S_IRUSR | S_IWUSR);
                if (p->bfd < 0) {
                        err(EXIT_FAILURE, "Could not open "
                            "'%s' for write", b_arg);
                }
        }

        /*
         * Require more verbosity to print anything when -w or -b is
         * specified on the command line:
         */
        if (w_arg != NULL || b_arg != NULL)
                verbose--;

        if (r_arg != NULL) {
                read_file(p);
                exit(EXIT_SUCCESS);
        }

        p->fd = fd = open("/dev/bpf", O_RDONLY);
        if (p->fd < 0)
                err(EXIT_FAILURE, "Could not open BPF device");

        if (ioctl(fd, BIOCVERSION, (caddr_t)&bv) < 0)
                err(EXIT_FAILURE, "BIOCVERSION ioctl failed");

        if (bv.bv_major != BPF_MAJOR_VERSION ||
            bv.bv_minor < BPF_MINOR_VERSION)
                errx(EXIT_FAILURE, "Kernel BPF filter out of date");

        /* USB transfers can be greater than 64KByte */
        v = 1U << 16;

        /* clear ifr structure */
        memset(&ifr, 0, sizeof(ifr));

        for ( ; v >= USBPF_HDR_LEN; v >>= 1) {
                (void)ioctl(fd, BIOCSBLEN, (caddr_t)&v);
                (void)strlcpy(ifr.ifr_name, i_arg, sizeof(ifr.ifr_name));
                if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) >= 0)
                        break;
        }
        if (v == 0)
                errx(EXIT_FAILURE, "No buffer size worked.");

        if (ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0)
                err(EXIT_FAILURE, "BIOCGBLEN ioctl failed");

        p->bufsize = v;
        p->buffer = (uint8_t *)malloc(p->bufsize);
        if (p->buffer == NULL)
                errx(EX_SOFTWARE, "Out of memory.");

        make_filter(&total_prog, snapshot);

        if (ioctl(p->fd, BIOCSETF, (caddr_t)&total_prog) < 0)
                err(EXIT_FAILURE, "BIOCSETF ioctl failed");

        free_filter(&total_prog);

        /* 1 second read timeout */
        tv.tv_sec = 1;
        tv.tv_usec = 0;
        if (ioctl(p->fd, BIOCSRTIMEOUT, (caddr_t)&tv) < 0)
                err(EXIT_FAILURE, "BIOCSRTIMEOUT ioctl failed");

        (void)signal(SIGINT, handle_sigint);

        do_loop(p);

        if (ioctl(fd, BIOCGSTATS, (caddr_t)&us) < 0)
                err(EXIT_FAILURE, "BIOCGSTATS ioctl failed");

        /* XXX what's difference between pkt_captured and us.us_recv? */
        printf("\n");
        printf("%d packets captured\n", pkt_captured);
        printf("%d packets received by filter\n", us.bs_recv);
        printf("%d packets dropped by kernel\n", us.bs_drop);

        if (p->fd > 0)
                close(p->fd);
        if (p->rfd > 0)
                close(p->rfd);
        if (p->wfd > 0)
                close(p->wfd);
        if (p->bfd > 0)
                close(p->bfd);

        return (EXIT_SUCCESS);
}