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Byte-swap the extra fields in the "version 1" USB monitor header.

master
Guy Harris 13 years ago
parent f9c2f9a852
commit ecd955e0df
  1. 28
      pcap-common.c
  2. 3
      pcap-common.h
  3. 41
      pcap/usb.h
  4. 5
      sf-pcap-ng.c
  5. 5
      sf-pcap.c

@ -1123,9 +1123,10 @@ linktype_to_dlt(int linktype)
* the reading host's byte order.
*/
void
swap_linux_usb_header(const struct pcap_pkthdr *hdr, u_char *buf)
swap_linux_usb_header(const struct pcap_pkthdr *hdr, u_char *buf,
int header_len_64_bytes)
{
pcap_usb_header *uhdr = (pcap_usb_header *)buf;
pcap_usb_header_mmapped *uhdr = (pcap_usb_header_mmapped *)buf;
/*
* The URB id is a totally opaque value; do we really need to
@ -1152,4 +1153,27 @@ swap_linux_usb_header(const struct pcap_pkthdr *hdr, u_char *buf)
if (hdr->caplen < 40)
return;
uhdr->data_len = SWAPLONG(uhdr->data_len);
if (header_len_64_bytes) {
/*
* This is either the "version 1" header, with
* 16 bytes of additional fields at the end, or
* a "version 0" header from a memory-mapped
* capture, with 16 bytes of zeroed-out padding
* at the end. Byte swap them as if this were
* a "version 1" header.
*/
if (hdr->caplen < 52)
return;
uhdr->interval = SWAPLONG(uhdr->interval);
if (hdr->caplen < 56)
return;
uhdr->start_frame = SWAPLONG(uhdr->start_frame);
if (hdr->caplen < 60)
return;
uhdr->xfer_flags = SWAPLONG(uhdr->xfer_flags);
if (hdr->caplen < 64)
return;
uhdr->ndesc = SWAPLONG(uhdr->ndesc);
}
}

@ -21,4 +21,5 @@ extern int dlt_to_linktype(int dlt);
extern int linktype_to_dlt(int linktype);
extern void swap_linux_usb_header(const struct pcap_pkthdr *hdr, u_char *buf);
extern void swap_linux_usb_header(const struct pcap_pkthdr *hdr, u_char *buf,
int header_len_64_bytes);

@ -54,7 +54,7 @@
/*
* USB setup header as defined in USB specification.
* Appears at the front of each packet in DLT_USB captures.
* Appears at the front of each Control S-type packet in DLT_USB captures.
*/
typedef struct _usb_setup {
u_int8_t bmRequestType;
@ -64,6 +64,13 @@ typedef struct _usb_setup {
u_int16_t wLength;
} pcap_usb_setup;
/*
* Information from the URB for Isochronous transfers.
*/
typedef struct _iso_rec {
int32_t error_count;
int32_t numdesc;
} iso_rec;
/*
* Header prepended by linux kernel to each event.
@ -87,8 +94,11 @@ typedef struct _usb_header {
} pcap_usb_header;
/*
* Header prepended by linux kernel to each event, plus padding in the
* internal buffer.
* Header prepended by linux kernel to each event for the 2.6.31
* and later kernels; for the 2.6.21 through 2.6.30 kernels, the
* "iso_rec" information, and the fields starting with "interval"
* are zeroed-out padding fields.
*
* Appears at the front of each packet in DLT_USB_LINUX_MMAPPED captures.
*/
typedef struct _usb_header_mmapped {
@ -105,8 +115,29 @@ typedef struct _usb_header_mmapped {
int32_t status;
u_int32_t urb_len;
u_int32_t data_len; /* amount of urb data really present in this event*/
pcap_usb_setup setup;
u_int8_t padding[16];
union {
pcap_usb_setup setup;
iso_rec iso;
} s;
int32_t interval; /* for Interrupt and Isochronous events */
int32_t start_frame; /* for Isochronous events */
u_int32_t xfer_flags; /* copy of URB's transfer flags */
u_int32_t ndesc; /* number of isochronous descriptors */
} pcap_usb_header_mmapped;
/*
* Isochronous descriptors; for isochronous transfers there might be
* one or more of these at the beginning of the packet data. The
* number of descriptors is given by the "ndesc" field in the header;
* as indicated, in older kernels that don't put the descriptors at
* the beginning of the packet, that field is zeroed out, so that field
* can be trusted even in captures from older kernels.
*/
typedef struct _usb_isodesc {
int32_t status;
u_int32_t offset;
u_int32_t len;
u_int8_t pad[4];
} usb_isodesc;
#endif

@ -1100,8 +1100,11 @@ found:
switch (p->linktype) {
case DLT_USB_LINUX:
swap_linux_usb_header(hdr, *data, 0);
break;
case DLT_USB_LINUX_MMAPPED:
swap_linux_usb_header(hdr, *data);
swap_linux_usb_header(hdr, *data, 1);
break;
}
}

@ -422,8 +422,11 @@ pcap_next_packet(pcap_t *p, struct pcap_pkthdr *hdr, u_char **data)
switch (p->linktype) {
case DLT_USB_LINUX:
swap_linux_usb_header(hdr, *data, 0);
break;
case DLT_USB_LINUX_MMAPPED:
swap_linux_usb_header(hdr, *data);
swap_linux_usb_header(hdr, *data, 1);
break;
}
}