diff options
| -rw-r--r-- | fastboot/usb_linux.c | 181 |
1 files changed, 103 insertions, 78 deletions
diff --git a/fastboot/usb_linux.c b/fastboot/usb_linux.c index b7a9ca3..9153c8d 100644 --- a/fastboot/usb_linux.c +++ b/fastboot/usb_linux.c @@ -75,10 +75,18 @@ struct usb_handle unsigned char ep_out; }; +/* True if name isn't a valid name for a USB device in /sys/bus/usb/devices. + * Device names are made up of numbers, dots, and dashes, e.g., '7-1.5'. + * We reject interfaces (e.g., '7-1.5:1.0') and host controllers (e.g. 'usb1'). + * The name must also start with a digit, to disallow '.' and '..' + */ static inline int badname(const char *name) { - while(*name) { - if(!isdigit(*name++)) return 1; + if (!isdigit(*name)) + return 1; + while(*++name) { + if(!isdigit(*name) && *name != '.' && *name != '-') + return 1; } return 0; } @@ -95,7 +103,8 @@ static int check(void *_desc, int len, unsigned type, int size) return 0; } -static int filter_usb_device(int fd, char *ptr, int len, int writable, +static int filter_usb_device(int fd, char* sysfs_name, + char *ptr, int len, int writable, ifc_match_func callback, int *ept_in_id, int *ept_out_id, int *ifc_id) { @@ -131,69 +140,35 @@ static int filter_usb_device(int fd, char *ptr, int len, int writable, info.dev_protocol = dev->bDeviceProtocol; info.writable = writable; - // read device serial number (if there is one) - info.serial_number[0] = 0; - if (dev->iSerialNumber) { - struct usbdevfs_ctrltransfer ctrl; - // Keep it short enough because some bootloaders are borked if the URB len is > 255 - // 128 is too big by 1. - __u16 buffer[127]; - - memset(buffer, 0, sizeof(buffer)); - - ctrl.bRequestType = USB_DIR_IN|USB_TYPE_STANDARD|USB_RECIP_DEVICE; - ctrl.bRequest = USB_REQ_GET_DESCRIPTOR; - ctrl.wValue = (USB_DT_STRING << 8) | dev->iSerialNumber; - //language ID (en-us) for serial number string - ctrl.wIndex = 0x0409; - ctrl.wLength = sizeof(buffer); - ctrl.data = buffer; - ctrl.timeout = 50; - - result = ioctl(fd, USBDEVFS_CONTROL, &ctrl); - if (result > 0) { - int i; - // skip first word, and copy the rest to the serial string, changing shorts to bytes. - result /= 2; - for (i = 1; i < result; i++) - info.serial_number[i - 1] = buffer[i]; - info.serial_number[i - 1] = 0; - } - } + snprintf(info.device_path, sizeof(info.device_path), "usb:%s", sysfs_name); - /* We need to get a path that represents a particular port on a particular - * hub. We are passed an fd that was obtained by opening an entry under - * /dev/bus/usb. Unfortunately, the names of those entries change each - * time devices are plugged and unplugged. So how to get a repeatable - * path? udevadm provided the inspiration. We can get the major and - * minor of the device file, read the symlink that can be found here: - * /sys/dev/char/<major>:<minor> - * and then use the last element of that path. As a concrete example, I - * have an Android device at /dev/bus/usb/001/027 so working with bash: - * $ ls -l /dev/bus/usb/001/027 - * crw-rw-r-- 1 root plugdev 189, 26 Apr 9 11:03 /dev/bus/usb/001/027 - * $ ls -l /sys/dev/char/189:26 - * lrwxrwxrwx 1 root root 0 Apr 9 11:03 /sys/dev/char/189:26 -> - * ../../devices/pci0000:00/0000:00:1a.7/usb1/1-4/1-4.2/1-4.2.3 - * So our device_path would be 1-4.2.3 which says my device is connected - * to port 3 of a hub on port 2 of a hub on port 4 of bus 1 (per - * http://www.linux-usb.org/FAQ.html). + /* Read device serial number (if there is one). + * We read the serial number from sysfs, since it's faster and more + * reliable than issuing a control pipe read, and also won't + * cause problems for devices which don't like getting descriptor + * requests while they're in the middle of flashing. */ - info.device_path[0] = '\0'; - result = fstat(fd, &st); - if (!result && S_ISCHR(st.st_mode)) { - char cdev[128]; - char link[256]; - char *slash; - ssize_t link_len; - snprintf(cdev, sizeof(cdev), "/sys/dev/char/%d:%d", - major(st.st_rdev), minor(st.st_rdev)); - link_len = readlink(cdev, link, sizeof(link) - 1); - if (link_len > 0) { - link[link_len] = '\0'; - slash = strrchr(link, '/'); - if (slash) - snprintf(info.device_path, sizeof(info.device_path), "usb:%s", slash+1); + info.serial_number[0] = '\0'; + if (dev->iSerialNumber) { + char path[80]; + int fd; + + snprintf(path, sizeof(path), + "/sys/bus/usb/devices/%s/serial", sysfs_name); + path[sizeof(path) - 1] = '\0'; + + fd = open(path, O_RDONLY); + if (fd >= 0) { + int chars_read = read(fd, info.serial_number, + sizeof(info.serial_number) - 1); + close(fd); + + if (chars_read <= 0) + info.serial_number[0] = '\0'; + else if (info.serial_number[chars_read - 1] == '\n') { + // strip trailing newline + info.serial_number[chars_read - 1] = '\0'; + } } } @@ -241,14 +216,73 @@ static int filter_usb_device(int fd, char *ptr, int len, int writable, return -1; } +static int read_sysfs_string(const char *sysfs_name, const char *sysfs_node, + char* buf, int bufsize) +{ + char path[80]; + int fd, n; + + snprintf(path, sizeof(path), + "/sys/bus/usb/devices/%s/%s", sysfs_name, sysfs_node); + path[sizeof(path) - 1] = '\0'; + + fd = open(path, O_RDONLY); + if (fd < 0) + return -1; + + n = read(fd, buf, bufsize - 1); + close(fd); + + if (n < 0) + return -1; + + buf[n] = '\0'; + + return n; +} + +static int read_sysfs_number(const char *sysfs_name, const char *sysfs_node) +{ + char buf[16]; + int value; + + if (read_sysfs_string(sysfs_name, sysfs_node, buf, sizeof(buf)) < 0) + return -1; + + if (sscanf(buf, "%d", &value) != 1) + return -1; + + return value; +} + +/* Given the name of a USB device in sysfs, get the name for the same + * device in devfs. Returns 0 for success, -1 for failure. + */ +static int convert_to_devfs_name(const char* sysfs_name, + char* devname, int devname_size) +{ + int busnum, devnum; + + busnum = read_sysfs_number(sysfs_name, "busnum"); + if (busnum < 0) + return -1; + + devnum = read_sysfs_number(sysfs_name, "devnum"); + if (devnum < 0) + return -1; + + snprintf(devname, devname_size, "/dev/bus/usb/%03d/%03d", busnum, devnum); + return 0; +} + static usb_handle *find_usb_device(const char *base, ifc_match_func callback) { usb_handle *usb = 0; - char busname[64], devname[64]; + char devname[64]; char desc[1024]; int n, in, out, ifc; - DIR *busdir, *devdir; + DIR *busdir; struct dirent *de; int fd; int writable; @@ -259,15 +293,7 @@ static usb_handle *find_usb_device(const char *base, ifc_match_func callback) while((de = readdir(busdir)) && (usb == 0)) { if(badname(de->d_name)) continue; - sprintf(busname, "%s/%s", base, de->d_name); - devdir = opendir(busname); - if(devdir == 0) continue; - -// DBG("[ scanning %s ]\n", busname); - while((de = readdir(devdir)) && (usb == 0)) { - - if(badname(de->d_name)) continue; - sprintf(devname, "%s/%s", busname, de->d_name); + if(!convert_to_devfs_name(de->d_name, devname, sizeof(devname))) { // DBG("[ scanning %s ]\n", devname); writable = 1; @@ -282,7 +308,7 @@ static usb_handle *find_usb_device(const char *base, ifc_match_func callback) n = read(fd, desc, sizeof(desc)); - if(filter_usb_device(fd, desc, n, writable, callback, + if(filter_usb_device(fd, de->d_name, desc, n, writable, callback, &in, &out, &ifc) == 0) { usb = calloc(1, sizeof(usb_handle)); strcpy(usb->fname, devname); @@ -301,7 +327,6 @@ static usb_handle *find_usb_device(const char *base, ifc_match_func callback) close(fd); } } - closedir(devdir); } closedir(busdir); @@ -431,5 +456,5 @@ int usb_close(usb_handle *h) usb_handle *usb_open(ifc_match_func callback) { - return find_usb_device("/dev/bus/usb", callback); + return find_usb_device("/sys/bus/usb/devices", callback); } |