From 0f6dba145a4be998e0e5e4ccd94d9df8609eb327 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 19 Jan 2021 20:44:51 +0100 Subject: [PATCH] usb: add pcap support. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Log all traffic of a specific usb device to a pcap file for later inspection. File format is compatible with linux usb monitor. Usage: qemu -device usb-${somedevice},pcap=file.pcap wireshark file.pcap Signed-off-by: Gerd Hoffmann Reviewed-by: Philippe Mathieu-Daudé Message-Id: <20210119194452.2148048-1-kraxel@redhat.com> Signed-off-by: Gerd Hoffmann --- hw/usb/bus.c | 16 +++ hw/usb/core.c | 17 +++ hw/usb/meson.build | 1 + hw/usb/pcap.c | 251 +++++++++++++++++++++++++++++++++++++++++++++ include/hw/usb.h | 8 ++ 5 files changed, 293 insertions(+) create mode 100644 hw/usb/pcap.c diff --git a/hw/usb/bus.c b/hw/usb/bus.c index 2b11041451..064f94e9c3 100644 --- a/hw/usb/bus.c +++ b/hw/usb/bus.c @@ -23,6 +23,7 @@ static Property usb_props[] = { USB_DEV_FLAG_FULL_PATH, true), DEFINE_PROP_BIT("msos-desc", USBDevice, flags, USB_DEV_FLAG_MSOS_DESC_ENABLE, true), + DEFINE_PROP_STRING("pcap", USBDevice, pcap_filename), DEFINE_PROP_END_OF_LIST() }; @@ -270,6 +271,17 @@ static void usb_qdev_realize(DeviceState *qdev, Error **errp) return; } } + + if (dev->pcap_filename) { + int fd = qemu_open_old(dev->pcap_filename, O_CREAT | O_WRONLY | O_TRUNC, 0666); + if (fd < 0) { + error_setg(errp, "open %s failed", dev->pcap_filename); + usb_qdev_unrealize(qdev); + return; + } + dev->pcap = fdopen(fd, "w"); + usb_pcap_init(dev->pcap); + } } static void usb_qdev_unrealize(DeviceState *qdev) @@ -283,6 +295,10 @@ static void usb_qdev_unrealize(DeviceState *qdev) g_free(s); } + if (dev->pcap) { + fclose(dev->pcap); + } + if (dev->attached) { usb_device_detach(dev); } diff --git a/hw/usb/core.c b/hw/usb/core.c index c895522a1d..975f76250a 100644 --- a/hw/usb/core.c +++ b/hw/usb/core.c @@ -154,6 +154,7 @@ static void do_token_setup(USBDevice *s, USBPacket *p) index = (s->setup_buf[5] << 8) | s->setup_buf[4]; if (s->setup_buf[0] & USB_DIR_IN) { + usb_pcap_ctrl(p, true); usb_device_handle_control(s, p, request, value, index, s->setup_len, s->data_buf); if (p->status == USB_RET_ASYNC) { @@ -190,6 +191,7 @@ static void do_token_in(USBDevice *s, USBPacket *p) switch(s->setup_state) { case SETUP_STATE_ACK: if (!(s->setup_buf[0] & USB_DIR_IN)) { + usb_pcap_ctrl(p, true); usb_device_handle_control(s, p, request, value, index, s->setup_len, s->data_buf); if (p->status == USB_RET_ASYNC) { @@ -197,6 +199,7 @@ static void do_token_in(USBDevice *s, USBPacket *p) } s->setup_state = SETUP_STATE_IDLE; p->actual_length = 0; + usb_pcap_ctrl(p, false); } break; @@ -215,6 +218,7 @@ static void do_token_in(USBDevice *s, USBPacket *p) } s->setup_state = SETUP_STATE_IDLE; p->status = USB_RET_STALL; + usb_pcap_ctrl(p, false); break; default: @@ -230,6 +234,7 @@ static void do_token_out(USBDevice *s, USBPacket *p) case SETUP_STATE_ACK: if (s->setup_buf[0] & USB_DIR_IN) { s->setup_state = SETUP_STATE_IDLE; + usb_pcap_ctrl(p, false); /* transfer OK */ } else { /* ignore additional output */ @@ -251,6 +256,7 @@ static void do_token_out(USBDevice *s, USBPacket *p) } s->setup_state = SETUP_STATE_IDLE; p->status = USB_RET_STALL; + usb_pcap_ctrl(p, false); break; default: @@ -288,6 +294,7 @@ static void do_parameter(USBDevice *s, USBPacket *p) usb_packet_copy(p, s->data_buf, s->setup_len); } + usb_pcap_ctrl(p, true); usb_device_handle_control(s, p, request, value, index, s->setup_len, s->data_buf); if (p->status == USB_RET_ASYNC) { @@ -301,6 +308,7 @@ static void do_parameter(USBDevice *s, USBPacket *p) p->actual_length = 0; usb_packet_copy(p, s->data_buf, s->setup_len); } + usb_pcap_ctrl(p, false); } /* ctrl complete function for devices which use usb_generic_handle_packet and @@ -311,6 +319,7 @@ void usb_generic_async_ctrl_complete(USBDevice *s, USBPacket *p) { if (p->status < 0) { s->setup_state = SETUP_STATE_IDLE; + usb_pcap_ctrl(p, false); } switch (s->setup_state) { @@ -325,6 +334,7 @@ void usb_generic_async_ctrl_complete(USBDevice *s, USBPacket *p) case SETUP_STATE_ACK: s->setup_state = SETUP_STATE_IDLE; p->actual_length = 0; + usb_pcap_ctrl(p, false); break; case SETUP_STATE_PARAM: @@ -359,12 +369,14 @@ USBDevice *usb_find_device(USBPort *port, uint8_t addr) static void usb_process_one(USBPacket *p) { USBDevice *dev = p->ep->dev; + bool nak; /* * Handlers expect status to be initialized to USB_RET_SUCCESS, but it * can be USB_RET_NAK here from a previous usb_process_one() call, * or USB_RET_ASYNC from going through usb_queue_one(). */ + nak = (p->status == USB_RET_NAK); p->status = USB_RET_SUCCESS; if (p->ep->nr == 0) { @@ -388,6 +400,9 @@ static void usb_process_one(USBPacket *p) } } else { /* data pipe */ + if (!nak) { + usb_pcap_data(p, true); + } usb_device_handle_data(dev, p); } } @@ -439,6 +454,7 @@ void usb_handle_packet(USBDevice *dev, USBPacket *p) assert(p->stream || !p->ep->pipeline || QTAILQ_EMPTY(&p->ep->queue)); if (p->status != USB_RET_NAK) { + usb_pcap_data(p, false); usb_packet_set_state(p, USB_PACKET_COMPLETE); } } @@ -458,6 +474,7 @@ void usb_packet_complete_one(USBDevice *dev, USBPacket *p) (p->short_not_ok && (p->actual_length < p->iov.size))) { ep->halted = true; } + usb_pcap_data(p, false); usb_packet_set_state(p, USB_PACKET_COMPLETE); QTAILQ_REMOVE(&ep->queue, p, queue); dev->port->ops->complete(dev->port, p); diff --git a/hw/usb/meson.build b/hw/usb/meson.build index f46c6b6655..653192cff6 100644 --- a/hw/usb/meson.build +++ b/hw/usb/meson.build @@ -5,6 +5,7 @@ softmmu_ss.add(files( 'bus.c', 'combined-packet.c', 'core.c', + 'pcap.c', 'libhw.c' )) diff --git a/hw/usb/pcap.c b/hw/usb/pcap.c new file mode 100644 index 0000000000..4350989d3a --- /dev/null +++ b/hw/usb/pcap.c @@ -0,0 +1,251 @@ +/* + * usb packet capture + * + * Copyright (c) 2021 Gerd Hoffmann + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#include "qemu/osdep.h" +#include "hw/usb.h" + +#define PCAP_MAGIC 0xa1b2c3d4 +#define PCAP_MAJOR 2 +#define PCAP_MINOR 4 + +/* https://wiki.wireshark.org/Development/LibpcapFileFormat */ + +struct pcap_hdr { + uint32_t magic_number; /* magic number */ + uint16_t version_major; /* major version number */ + uint16_t version_minor; /* minor version number */ + int32_t thiszone; /* GMT to local correction */ + uint32_t sigfigs; /* accuracy of timestamps */ + uint32_t snaplen; /* max length of captured packets, in octets */ + uint32_t network; /* data link type */ +}; + +struct pcaprec_hdr { + uint32_t ts_sec; /* timestamp seconds */ + uint32_t ts_usec; /* timestamp microseconds */ + uint32_t incl_len; /* number of octets of packet saved in file */ + uint32_t orig_len; /* actual length of packet */ +}; + +/* https://www.tcpdump.org/linktypes.html */ +/* linux: Documentation/usb/usbmon.rst */ +/* linux: drivers/usb/mon/mon_bin.c */ + +#define LINKTYPE_USB_LINUX 189 /* first 48 bytes only */ +#define LINKTYPE_USB_LINUX_MMAPPED 220 /* full 64 byte header */ + +struct usbmon_packet { + uint64_t id; /* 0: URB ID - from submission to callback */ + unsigned char type; /* 8: Same as text; extensible. */ + unsigned char xfer_type; /* ISO (0), Intr, Control, Bulk (3) */ + unsigned char epnum; /* Endpoint number and transfer direction */ + unsigned char devnum; /* Device address */ + uint16_t busnum; /* 12: Bus number */ + char flag_setup; /* 14: Same as text */ + char flag_data; /* 15: Same as text; Binary zero is OK. */ + int64_t ts_sec; /* 16: gettimeofday */ + int32_t ts_usec; /* 24: gettimeofday */ + int32_t status; /* 28: */ + unsigned int length; /* 32: Length of data (submitted or actual) */ + unsigned int len_cap; /* 36: Delivered length */ + union { /* 40: */ + unsigned char setup[8]; /* Only for Control S-type */ + struct iso_rec { /* Only for ISO */ + int32_t error_count; + int32_t numdesc; + } iso; + } s; + int32_t interval; /* 48: Only for Interrupt and ISO */ + int32_t start_frame; /* 52: For ISO */ + uint32_t xfer_flags; /* 56: copy of URB's transfer_flags */ + uint32_t ndesc; /* 60: Actual number of ISO descriptors */ +}; /* 64 total length */ + +/* ------------------------------------------------------------------------ */ + +#define CTRL_LEN 4096 +#define DATA_LEN 256 + +static int usbmon_status(USBPacket *p) +{ + switch (p->status) { + case USB_RET_SUCCESS: + return 0; + case USB_RET_NODEV: + return -19; /* -ENODEV */ + default: + return -121; /* -EREMOTEIO */ + } +} + +static unsigned int usbmon_epnum(USBPacket *p) +{ + unsigned epnum = 0; + + epnum |= p->ep->nr; + epnum |= (p->pid == USB_TOKEN_IN) ? 0x80 : 0; + return epnum; +} + +static unsigned char usbmon_xfer_type[] = { + [USB_ENDPOINT_XFER_CONTROL] = 2, + [USB_ENDPOINT_XFER_ISOC] = 0, + [USB_ENDPOINT_XFER_BULK] = 3, + [USB_ENDPOINT_XFER_INT] = 1, +}; + +static void do_usb_pcap_header(FILE *fp, struct usbmon_packet *packet) +{ + struct pcaprec_hdr header; + struct timeval tv; + + gettimeofday(&tv, NULL); + packet->ts_sec = tv.tv_sec; + packet->ts_usec = tv.tv_usec; + + header.ts_sec = packet->ts_sec; + header.ts_usec = packet->ts_usec; + header.incl_len = packet->len_cap; + header.orig_len = packet->length + sizeof(*packet); + fwrite(&header, sizeof(header), 1, fp); + fwrite(packet, sizeof(*packet), 1, fp); +} + +static void do_usb_pcap_ctrl(FILE *fp, USBPacket *p, bool setup) +{ + USBDevice *dev = p->ep->dev; + bool in = dev->setup_buf[0] & USB_DIR_IN; + struct usbmon_packet packet = { + .id = 0, + .type = setup ? 'S' : 'C', + .xfer_type = usbmon_xfer_type[USB_ENDPOINT_XFER_CONTROL], + .epnum = in ? 0x80 : 0, + .devnum = dev->addr, + .flag_data = '=', + .length = dev->setup_len, + }; + int data_len = dev->setup_len; + + if (data_len > CTRL_LEN) { + data_len = CTRL_LEN; + } + if (setup) { + memcpy(packet.s.setup, dev->setup_buf, 8); + } else { + packet.status = usbmon_status(p); + } + + if (in && setup) { + packet.flag_data = '<'; + packet.length = 0; + data_len = 0; + } + if (!in && !setup) { + packet.flag_data = '>'; + packet.length = 0; + data_len = 0; + } + + packet.len_cap = data_len + sizeof(packet); + do_usb_pcap_header(fp, &packet); + if (data_len) { + fwrite(dev->data_buf, data_len, 1, fp); + } + + fflush(fp); +} + +static void do_usb_pcap_data(FILE *fp, USBPacket *p, bool setup) +{ + struct usbmon_packet packet = { + .id = p->id, + .type = setup ? 'S' : 'C', + .xfer_type = usbmon_xfer_type[p->ep->type], + .epnum = usbmon_epnum(p), + .devnum = p->ep->dev->addr, + .flag_data = '=', + .length = p->iov.size, + }; + int data_len = p->iov.size; + + if (p->ep->nr == 0) { + /* ignore control pipe packets */ + return; + } + + if (data_len > DATA_LEN) { + data_len = DATA_LEN; + } + if (!setup) { + packet.status = usbmon_status(p); + if (packet.length > p->actual_length) { + packet.length = p->actual_length; + } + if (data_len > p->actual_length) { + data_len = p->actual_length; + } + } + + if (p->pid == USB_TOKEN_IN && setup) { + packet.flag_data = '<'; + packet.length = 0; + data_len = 0; + } + if (p->pid == USB_TOKEN_OUT && !setup) { + packet.flag_data = '>'; + packet.length = 0; + data_len = 0; + } + + packet.len_cap = data_len + sizeof(packet); + do_usb_pcap_header(fp, &packet); + if (data_len) { + void *buf = g_malloc(data_len); + iov_to_buf(p->iov.iov, p->iov.niov, 0, buf, data_len); + fwrite(buf, data_len, 1, fp); + g_free(buf); + } + + fflush(fp); +} + +void usb_pcap_init(FILE *fp) +{ + struct pcap_hdr header = { + .magic_number = PCAP_MAGIC, + .version_major = 2, + .version_minor = 4, + .snaplen = MAX(CTRL_LEN, DATA_LEN) + sizeof(struct usbmon_packet), + .network = LINKTYPE_USB_LINUX_MMAPPED, + }; + + fwrite(&header, sizeof(header), 1, fp); +} + +void usb_pcap_ctrl(USBPacket *p, bool setup) +{ + FILE *fp = p->ep->dev->pcap; + + if (!fp) { + return; + } + + do_usb_pcap_ctrl(fp, p, setup); +} + +void usb_pcap_data(USBPacket *p, bool setup) +{ + FILE *fp = p->ep->dev->pcap; + + if (!fp) { + return; + } + + do_usb_pcap_data(fp, p, setup); +} diff --git a/include/hw/usb.h b/include/hw/usb.h index a70a72e917..abfbfc5284 100644 --- a/include/hw/usb.h +++ b/include/hw/usb.h @@ -231,6 +231,9 @@ struct USBDevice { void *opaque; uint32_t flags; + char *pcap_filename; + FILE *pcap; + /* Actual connected speed */ int speed; /* Supported speeds, not in info because it may be variable (hostdevs) */ @@ -570,4 +573,9 @@ int usb_get_quirks(uint16_t vendor_id, uint16_t product_id, uint8_t interface_class, uint8_t interface_subclass, uint8_t interface_protocol); +/* pcap.c */ +void usb_pcap_init(FILE *fp); +void usb_pcap_ctrl(USBPacket *p, bool setup); +void usb_pcap_data(USBPacket *p, bool setup); + #endif