[Qemu-devel] [PATCH 08/18] usb-linux: fix device path aka physical port handling

[Gerd Hoffmann <kraxel@redhat.com>]

The device path isn't just a number.  It specifies the physical port
the device is connected to and in case the device is connected via
usb hub you'll have two numbers there, like this: "5.1".  The first
specifies the root port where the hub is plugged into, the second
specifies the port number of the hub where the device is plugged in.
With multiple hubs chained the string can become longer.

This patch renames devpath to port and makes it a string.   It also
adapts the sysfs parsing code accordingly.  The parser code is also more
strict now and skips the root hubs (which can't be assigned anyway).

The "info usbhost" monitor command now prints bus number, (os-assigned)
device address and physical port for each device.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 usb-linux.c |   42 ++++++++++++++++++++----------------------
 1 files changed, 20 insertions(+), 22 deletions(-)

diff --git a/usb-linux.c b/usb-linux.c
index 84d3a8b..2c6e249 100644
--- a/usb-linux.c
+++ b/usb-linux.c
@@ -54,7 +54,7 @@ struct usb_ctrltransfer {
     void *data;
 };
 
-typedef int USBScanFunc(void *opaque, int bus_num, int addr, int devpath,
+typedef int USBScanFunc(void *opaque, int bus_num, int addr, char *port,
                         int class_id, int vendor_id, int product_id,
                         const char *product_name, int speed);
 
@@ -71,6 +71,7 @@ typedef int USBScanFunc(void *opaque, int bus_num, int addr, int devpath,
 #define USBPROCBUS_PATH "/proc/bus/usb"
 #define PRODUCT_NAME_SZ 32
 #define MAX_ENDPOINTS 15
+#define MAX_PORTLEN 16
 #define USBDEVBUS_PATH "/dev/bus/usb"
 #define USBSYSBUS_PATH "/sys/bus/usb"
 
@@ -123,7 +124,7 @@ typedef struct USBHostDevice {
     /* Host side address */
     int bus_num;
     int addr;
-    int devpath;
+    char port[MAX_PORTLEN];
     struct USBAutoFilter match;
 
     QTAILQ_ENTRY(USBHostDevice) next;
@@ -836,7 +837,7 @@ static int usb_linux_get_configuration(USBHostDevice *s)
         char device_name[32], line[1024];
         int configuration;
 
-        sprintf(device_name, "%d-%d", s->bus_num, s->devpath);
+        sprintf(device_name, "%d-%s", s->bus_num, s->port);
 
         if (!usb_host_read_file(line, sizeof(line), "bConfigurationValue",
                                 device_name)) {
@@ -882,7 +883,7 @@ static uint8_t usb_linux_get_alt_setting(USBHostDevice *s,
         char device_name[64], line[1024];
         int alt_setting;
 
-        sprintf(device_name, "%d-%d:%d.%d", s->bus_num, s->devpath,
+        sprintf(device_name, "%d-%s:%d.%d", s->bus_num, s->port,
                 (int)configuration, (int)interface);
 
         if (!usb_host_read_file(line, sizeof(line), "bAlternateSetting",
@@ -1001,7 +1002,7 @@ static int usb_linux_update_endp_table(USBHostDevice *s)
 }
 
 static int usb_host_open(USBHostDevice *dev, int bus_num,
-                         int addr, int devpath, const char *prod_name)
+                         int addr, char *port, const char *prod_name)
 {
     int fd = -1, ret;
     struct usbdevfs_connectinfo ci;
@@ -1027,7 +1028,7 @@ static int usb_host_open(USBHostDevice *dev, int bus_num,
 
     dev->bus_num = bus_num;
     dev->addr = addr;
-    dev->devpath = devpath;
+    strcpy(dev->port, port);
     dev->fd = fd;
 
     /* read the device description */
@@ -1401,8 +1402,9 @@ static int usb_host_scan_sys(void *opaque, USBScanFunc *func)
 {
     DIR *dir = NULL;
     char line[1024];
-    int bus_num, addr, devpath, speed, class_id, product_id, vendor_id;
+    int bus_num, addr, speed, class_id, product_id, vendor_id;
     int ret = 0;
+    char port[MAX_PORTLEN];
     char product_name[512];
     struct dirent *de;
 
@@ -1414,12 +1416,8 @@ static int usb_host_scan_sys(void *opaque, USBScanFunc *func)
 
     while ((de = readdir(dir))) {
         if (de->d_name[0] != '.' && !strchr(de->d_name, ':')) {
-            char *tmpstr = de->d_name;
-            if (!strncmp(de->d_name, "usb", 3)) {
-                tmpstr += 3;
-            }
-            if (sscanf(tmpstr, "%d-%d", &bus_num, &devpath) < 1) {
-                goto the_end;
+            if (sscanf(de->d_name, "%d-%7[0-9.]", &bus_num, port) < 2) {
+                continue;
             }
 
             if (!usb_host_read_file(line, sizeof(line), "devnum", de->d_name)) {
@@ -1471,7 +1469,7 @@ static int usb_host_scan_sys(void *opaque, USBScanFunc *func)
                 speed = USB_SPEED_FULL;
             }
 
-            ret = func(opaque, bus_num, addr, devpath, class_id, vendor_id,
+            ret = func(opaque, bus_num, addr, port, class_id, vendor_id,
                        product_id, product_name, speed);
             if (ret) {
                 goto the_end;
@@ -1562,7 +1560,7 @@ static int usb_host_scan(void *opaque, USBScanFunc *func)
 
 static QEMUTimer *usb_auto_timer;
 
-static int usb_host_auto_scan(void *opaque, int bus_num, int addr, int devpath,
+static int usb_host_auto_scan(void *opaque, int bus_num, int addr, char *port,
                               int class_id, int vendor_id, int product_id,
                               const char *product_name, int speed)
 {
@@ -1598,7 +1596,7 @@ static int usb_host_auto_scan(void *opaque, int bus_num, int addr, int devpath,
         }
         DPRINTF("husb: auto open: bus_num %d addr %d\n", bus_num, addr);
 
-        usb_host_open(s, bus_num, addr, devpath, product_name);
+        usb_host_open(s, bus_num, addr, port, product_name);
     }
 
     return 0;
@@ -1720,8 +1718,8 @@ static const char *usb_class_str(uint8_t class)
     return p->class_name;
 }
 
-static void usb_info_device(Monitor *mon, int bus_num, int addr, int class_id,
-                            int vendor_id, int product_id,
+static void usb_info_device(Monitor *mon, int bus_num, int addr, char *port,
+                            int class_id, int vendor_id, int product_id,
                             const char *product_name,
                             int speed)
 {
@@ -1742,8 +1740,8 @@ static void usb_info_device(Monitor *mon, int bus_num, int addr, int class_id,
         break;
     }
 
-    monitor_printf(mon, "  Device %d.%d, speed %s Mb/s\n",
-                bus_num, addr, speed_str);
+    monitor_printf(mon, "  Bus %d, Addr %d, Port %s, Speed %s Mb/s\n",
+                   bus_num, addr, port, speed_str);
     class_str = usb_class_str(class_id);
     if (class_str) {
         monitor_printf(mon, "    %s:", class_str);
@@ -1758,14 +1756,14 @@ static void usb_info_device(Monitor *mon, int bus_num, int addr, int class_id,
 }
 
 static int usb_host_info_device(void *opaque, int bus_num, int addr,
-                                int devpath, int class_id,
+                                char *path, int class_id,
                                 int vendor_id, int product_id,
                                 const char *product_name,
                                 int speed)
 {
     Monitor *mon = opaque;
 
-    usb_info_device(mon, bus_num, addr, class_id, vendor_id, product_id,
+    usb_info_device(mon, bus_num, addr, path, class_id, vendor_id, product_id,
                     product_name, speed);
     return 0;
 }
-- 
1.7.1