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am e6e5daac: am edeed28b: am 4a280e3d: Merge "Don\'t use control requests to read device serial numbers."

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* commit 'e6e5daace55672b1ec8fb6c5c17a85ee1531f7ad':
  Don't use control requests to read device serial numbers.
This commit is contained in:
jp abgrall 2013-09-17 14:20:31 -07:00 committed by Android Git Automerger
commit 9256bd4670
1 changed files with 103 additions and 78 deletions
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181
fastboot/usb_linux.c
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@ -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];
snprintf(info.device_path, sizeof(info.device_path), "usb:%s", sysfs_name);
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;
}
}
/* 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);
}