Re: [libvirt] [PATCH v2] Implement path lookup for USB by vendor:product

Based off how QEMU does it, look through /sys/bus/usb/devices/* for matching vendor:product info, and if found, use info from the surrounding files to build the device's /dev/bus/usb path. This fixes USB device assignment by vendor:product when running qemu as non-root (well, it should, but for some reason I couldn't reproduce the failure people are seeing in [1], but it appears to work properly) [1] https://bugzilla.redhat.com/show_bug.cgi?id=542450 v2: Drop 'bus.addr only' checks in security drivers Use various util helpers Signed-off-by: Cole Robinson <crobinso(a)redhat.com&gt; --- po/POTFILES.in | 1 + src/qemu/qemu_driver.c | 9 +-- src/security/security_selinux.c | 25 ++++----- src/security/virt-aa-helper.c | 32 +++++------ src/util/hostusb.c | 110 +++++++++++++++++++++++++++++++++++++- src/util/hostusb.h | 4 +- 6 files changed, 141 insertions(+), 40 deletions(-) diff --git a/po/POTFILES.in b/po/POTFILES.in index c9c78b6..3b82a74 100644 --- a/po/POTFILES.in +++ b/po/POTFILES.in @@ -55,6 +55,7 @@ src/uml/uml_conf.c src/uml/uml_driver.c src/util/bridge.c src/util/conf.c +src/util/hostusb.c src/util/json.c src/util/logging.c src/util/pci.c diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index deb8adc..f03ce91 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -2105,14 +2105,11 @@ static int qemuDomainSetHostdevUSBOwnership(virConnectPtr conn, struct qemuFileOwner owner = { uid, gid }; int ret = -1; - /* XXX what todo for USB devs assigned based on product/vendor ? Doom :-( */ - if (!def->source.subsys.u.usb.bus || - !def->source.subsys.u.usb.device) - return 0; - usbDevice *dev = usbGetDevice(conn, def->source.subsys.u.usb.bus, - def->source.subsys.u.usb.device); + def->source.subsys.u.usb.device, + def->source.subsys.u.usb.vendor, + def->source.subsys.u.usb.product); if (!dev) goto cleanup; diff --git a/src/security/security_selinux.c b/src/security/security_selinux.c index 000bc8a..cb585ed 100644 --- a/src/security/security_selinux.c +++ b/src/security/security_selinux.c @@ -481,20 +481,17 @@ SELinuxSetSecurityHostdevLabel(virConnectPtr conn, switch (dev->source.subsys.type) { case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_USB: { - if (dev->source.subsys.u.usb.bus && dev->source.subsys.u.usb.device) { - usbDevice *usb = usbGetDevice(conn, - dev->source.subsys.u.usb.bus, - dev->source.subsys.u.usb.device); + usbDevice *usb = usbGetDevice(conn, + dev->source.subsys.u.usb.bus, + dev->source.subsys.u.usb.device, + dev->source.subsys.u.usb.vendor, + dev->source.subsys.u.usb.product); - if (!usb) - goto done; + if (!usb) + goto done; - ret = usbDeviceFileIterate(conn, usb, SELinuxSetSecurityUSBLabel, vm); - usbFreeDevice(conn, usb); - } else { - /* XXX deal with product/vendor better */ - ret = 0; - } + ret = usbDeviceFileIterate(conn, usb, SELinuxSetSecurityUSBLabel, vm); + usbFreeDevice(conn, usb); break; } @@ -556,7 +553,9 @@ SELinuxRestoreSecurityHostdevLabel(virConnectPtr conn, case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_USB: { usbDevice *usb = usbGetDevice(conn, dev->source.subsys.u.usb.bus, - dev->source.subsys.u.usb.device); + dev->source.subsys.u.usb.device, + dev->source.subsys.u.usb.vendor, + dev->source.subsys.u.usb.product); if (!usb) goto done; diff --git a/src/security/virt-aa-helper.c b/src/security/virt-aa-helper.c index 35b29ad..3c8b49a 100644 --- a/src/security/virt-aa-helper.c +++ b/src/security/virt-aa-helper.c @@ -836,24 +836,22 @@ get_files(vahControl * ctl) virDomainHostdevDefPtr dev = ctl->def->hostdevs[i]; switch (dev->source.subsys.type) { case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_USB: { - if (dev->source.subsys.u.usb.bus && - dev->source.subsys.u.usb.device) { - usbDevice *usb = usbGetDevice(NULL, - dev->source.subsys.u.usb.bus, - dev->source.subsys.u.usb.device); - if (usb == NULL) - continue; - rc = usbDeviceFileIterate(NULL, usb, - file_iterate_cb, &buf); - usbFreeDevice(NULL, usb); - if (rc != 0) - goto clean; - else { - /* TODO: deal with product/vendor better */ - rc = 0; - } - } + usbDevice *usb = usbGetDevice(NULL, + dev->source.subsys.u.usb.bus, + dev->source.subsys.u.usb.device, + dev->source.subsys.u.usb.vendor, + dev->source.subsys.u.usb.product); + + if (usb == NULL) + continue; + + rc = usbDeviceFileIterate(NULL, usb, + file_iterate_cb, &buf); + usbFreeDevice(NULL, usb); + if (rc != 0) + goto clean; break; + } } /* TODO: update so files in /sys are readonly case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_PCI: { diff --git a/src/util/hostusb.c b/src/util/hostusb.c index 07e10b1..8fbb486 100644 --- a/src/util/hostusb.c +++ b/src/util/hostusb.c @@ -37,9 +37,10 @@ #include "util.h" #include "virterror_internal.h" +#define USB_SYSFS "/sys/bus/usb" #define USB_DEVFS "/dev/bus/usb/" -#define USB_ID_LEN 10 /* "XXXX XXXX" */ -#define USB_ADDR_LEN 8 /* "XXX:XXX" */ +#define USB_ID_LEN 10 /* "1234 5678" */ +#define USB_ADDR_LEN 8 /* "123:456" */ struct _usbDevice { unsigned bus; @@ -57,11 +58,108 @@ struct _usbDevice { virReportErrorHelper(conn, VIR_FROM_NONE, code, __FILE__, \ __FUNCTION__, __LINE__, fmt) +static int usbSysReadFile(virConnectPtr conn, + const char *f_name, const char *d_name, + int base, unsigned *value) +{ + int ret = -1, tmp; + char *buf = NULL; + char *filename = NULL; + char *ignore = NULL; + + tmp = virAsprintf(&filename, USB_SYSFS "/devices/%s/%s", d_name, f_name); + if (tmp < 0) { + virReportOOMError(conn); + goto error; + } + + if (virFileReadAll(filename, 1024, &buf) < 0) + goto error; + + if (virStrToLong_ui(buf, &ignore, base, value) < 0) { + usbReportError(conn, VIR_ERR_INTERNAL_ERROR, + _("Could not parse usb file %s"), filename); + goto error; + } + + ret = 0; +error: + VIR_FREE(filename); + VIR_FREE(buf); + return ret; +} + +static int usbFindBusByVendor(virConnectPtr conn, + unsigned vendor, unsigned product, + unsigned *bus, unsigned *devno) +{ + DIR *dir = NULL; + int ret = -1, found = 0; + char *ignore = NULL; + struct dirent *de; + + dir = opendir(USB_SYSFS "/devices"); + if (!dir) { + virReportSystemError(conn, errno, + _("Could not open directory %s"), + USB_SYSFS "/devices"); + goto error; + } + + while ((de = readdir(dir))) { + unsigned found_prod, found_vend; + if (de->d_name[0] == '.' || strchr(de->d_name, ':')) + continue; + + if (usbSysReadFile(conn, "idVendor", de->d_name, + 16, &found_vend) < 0) + goto error; + if (usbSysReadFile(conn, "idProduct", de->d_name, + 16, &found_prod) < 0) + goto error; + + if (found_prod == product && found_vend == vendor) { + /* Lookup bus.addr info */ + char *tmpstr = de->d_name; + unsigned found_bus, found_addr; + + if (STREQ(de->d_name, "usb")) + tmpstr += 3; + + if (virStrToLong_ui(tmpstr, &ignore, 10, &found_bus) < 0) { + usbReportError(conn, VIR_ERR_INTERNAL_ERROR, + _("Failed to parse dir name '%s'"), + de->d_name); + goto error; + } + + if (usbSysReadFile(conn, "devnum", de->d_name, + 10, &found_addr) < 0) + goto error; + + *bus = found_bus; + *devno = found_addr; + found = 1; + break; + } + } + + if (!found) + usbReportError(conn, VIR_ERR_INTERNAL_ERROR, + _("Did not find USB device %x:%x"), vendor, product); + else + ret = 0; + +error: + return ret; +} usbDevice * usbGetDevice(virConnectPtr conn, unsigned bus, - unsigned devno) + unsigned devno, + unsigned vendor, + unsigned product) { usbDevice *dev; @@ -70,6 +168,12 @@ usbGetDevice(virConnectPtr conn, return NULL; } + if (vendor) { + /* Look up bus.dev by vendor:product */ + if (usbFindBusByVendor(conn, vendor, product, &bus, &devno) < 0) + return NULL; + } + dev->bus = bus; dev->dev = devno; diff --git a/src/util/hostusb.h b/src/util/hostusb.h index 7f75c8b..739a4aa 100644 --- a/src/util/hostusb.h +++ b/src/util/hostusb.h @@ -28,7 +28,9 @@ typedef struct _usbDevice usbDevice; usbDevice *usbGetDevice (virConnectPtr conn, unsigned bus, - unsigned devno); + unsigned devno, + unsigned vendor, + unsigned product); void usbFreeDevice (virConnectPtr conn, usbDevice *dev); --