Re: [Qemu-devel] Re: [PATCH] Add USB sys file-system support (v6)

[Jason Wessel <jason.wessel@windriver.com>]

[-- Attachment #1: Type: text/plain, Size: 1071 bytes --]

Anthony Liguori wrote:
> TJ wrote:
>   
>> +    snprintf(buf, sizeof(buf), "%s/%03d/%03d", usb_host_device_path,
>>               bus_num, addr);
>>   
>>     
>
> You have tabs here.
>
>   
>>      fd = open(buf, O_RDWR | O_NONBLOCK);
>>      }
>>   
>>     
>
> And here and almost everywhere.
>
>   
>> +    while ((de = readdir(dir))) {
>> +    	if (de->d_name[0] != '.' && ! strchr(de->d_name, ':')) {
>> +    		char filename[PATH_MAX];
>> +    		char* tmpstr = de->d_name;
>> +    		if (!strncmp(de->d_name, "usb", 3))
>> +    			tmpstr += 3;
>>   
>>     
>
> This is indented wrong.
>
>   
>> +    			}
>> +    			else { // devices found in /dev/bus/usb/ (yes - not a mistake!)
>>   
>>     
>
> else belongs on the same line as curly brackets.  Please avoid C99 
> comments too.
>
>   


Anthony if that is all that you consider to be blocking a commit,
attached is a fixed version with white space and comments fixups.

It would be good to get this applied because it actually makes the usb
pass through usable on a significant number of hosts.

Thanks,
Jason.

[-- Attachment #2: sys-usb.patch --]
[-- Type: text/x-diff, Size: 10320 bytes --]

From: TJ <linux@tjworld.net>
Subject: [PATCH] Add USB sys file-system support

This patch adds support for host USB devices discovered via:

/sys/bus/usb/devices/* and opened from /dev/bus/usb/*/*
/dev/bus/usb/devices and opened from /dev/bus/usb/*/*

in addition to the existing discovery via:

/proc/bus/usb/devices and opened from /proc/bus/usb/*/*

Signed-off-by: TJ <linux@tjworld.net>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>

---
 usb-linux.c |  228 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 217 insertions(+), 11 deletions(-)

--- a/usb-linux.c
+++ b/usb-linux.c
@@ -7,6 +7,10 @@
  *      Support for host device auto connect & disconnect
  *      Major rewrite to support fully async operation
  *
+ * Copyright 2008 TJ <linux@tjworld.net>
+ *      Added flexible support for /dev/bus/usb /sys/bus/usb/devices in addition
+ *      to the legacy /proc/bus/usb USB device discovery and handling
+ *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
@@ -72,9 +76,20 @@ static int usb_host_find_device(int *pbu
 #define dprintf(...)
 #endif
 
-#define USBDEVFS_PATH "/proc/bus/usb"
+#define USBPROCBUS_PATH "/proc/bus/usb"
 #define PRODUCT_NAME_SZ 32
 #define MAX_ENDPOINTS 16
+#define USBDEVBUS_PATH "/dev/bus/usb"
+#define USBSYSBUS_PATH "/sys/bus/usb"
+
+static char *usb_host_device_path;
+
+#define USB_FS_NONE 0
+#define USB_FS_PROC 1
+#define USB_FS_DEV 2
+#define USB_FS_SYS 3
+
+static int usb_fs_type = 0;
 
 /* endpoint association data */
 struct endp_data {
@@ -890,13 +905,18 @@ static USBDevice *usb_host_device_open_a
 
     printf("husb: open device %d.%d\n", bus_num, addr);
 
-    snprintf(buf, sizeof(buf), USBDEVFS_PATH "/%03d/%03d",
+    if (!usb_host_device_path) {
+        perror("husb: USB Host Device Path not set");
+        goto fail;
+    }
+    snprintf(buf, sizeof(buf), "%s/%03d/%03d", usb_host_device_path,
              bus_num, addr);
     fd = open(buf, O_RDWR | O_NONBLOCK);
     if (fd < 0) {
         perror(buf);
         goto fail;
     }
+    dprintf("husb: opened %s\n", buf);
 
     /* read the device description */
     dev->descr_len = read(fd, dev->descr, sizeof(dev->descr));
@@ -1038,23 +1058,29 @@ static int get_tag_value(char *buf, int 
     return q - buf;
 }
 
-static int usb_host_scan(void *opaque, USBScanFunc *func)
+/*
+ * Use /proc/bus/usb/devices or /dev/bus/usb/devices file to determine
+ * host's USB devices. This is legacy support since many distributions
+ * are moving to /sys/bus/usb
+ */
+static int usb_host_scan_dev(void *opaque, USBScanFunc *func)
 {
-    FILE *f;
+    FILE *f = 0;
     char line[1024];
     char buf[1024];
     int bus_num, addr, speed, device_count, class_id, product_id, vendor_id;
-    int ret;
     char product_name[512];
+    int ret = 0;
 
-    f = fopen(USBDEVFS_PATH "/devices", "r");
+    snprintf(line, sizeof(line), "%s/devices", usb_host_device_path);
+    f = fopen(line, "r");
     if (!f) {
-        term_printf("husb: could not open %s\n", USBDEVFS_PATH "/devices");
-        return 0;
+        perror("husb: cannot open devices file");
+        goto the_end;
     }
+
     device_count = 0;
     bus_num = addr = speed = class_id = product_id = vendor_id = 0;
-    ret = 0;
     for(;;) {
         if (fgets(line, sizeof(line), f) == NULL)
             break;
@@ -1108,10 +1134,190 @@ static int usb_host_scan(void *opaque, U
     if (device_count && (vendor_id || product_id)) {
         /* Add the last device.  */
         ret = func(opaque, bus_num, addr, class_id, vendor_id,
-                   product_id, product_name, speed);
+                    product_id, product_name, speed);
+    }
+ the_end:
+    if (f) fclose(f);
+    return ret;
+}
+
+/*
+ * Use /sys/bus/usb/devices/ directory to determine host's USB
+ * devices.
+ *
+ * This code is taken from Robert Schiele's original patches posted to
+ * the Novell bug-tracker https://bugzilla.novell.com/show_bug.cgi?id=241950
+ */
+static int usb_host_scan_sys(void *opaque, USBScanFunc *func)
+{
+    FILE *f;
+    DIR *dir = 0;
+    char line[1024];
+    int bus_num, addr, speed, class_id, product_id, vendor_id;
+    int ret = 0;
+    char product_name[512];
+    struct dirent* de;
+
+    dir = opendir(USBSYSBUS_PATH "/devices");
+    if (!dir) {
+        perror("husb: cannot open devices directory");
+        goto the_end;
+    }
+
+    while ((de = readdir(dir))) {
+        if (de->d_name[0] != '.' && ! strchr(de->d_name, ':')) {
+            char filename[PATH_MAX];
+            char* tmpstr = de->d_name;
+            if (!strncmp(de->d_name, "usb", 3))
+                tmpstr += 3;
+
+            bus_num = atoi(tmpstr);
+            snprintf(filename, PATH_MAX, USBSYSBUS_PATH "/devices/%s/devnum", de->d_name);
+            f = fopen(filename, "r");
+            if (!f) {
+                term_printf("Could not open %s\n", filename);
+                goto the_end;
+            }
+            fgets(line, sizeof(line), f);
+            fclose(f);
+            addr = atoi(line);
+            snprintf(filename, PATH_MAX, USBSYSBUS_PATH "/devices/%s/bDeviceClass", de->d_name);
+            f = fopen(filename, "r");
+            if (!f) {
+                term_printf("Could not open %s\n", filename);
+                goto the_end;
+            }
+            fgets(line, sizeof(line), f);
+            fclose(f);
+            class_id = strtoul(line, NULL, 16);
+            snprintf(filename, PATH_MAX, USBSYSBUS_PATH "/devices/%s/idVendor", de->d_name);
+            f = fopen(filename, "r");
+            if (!f) {
+                term_printf("Could not open %s\n", filename);
+                goto the_end;
+            }
+            fgets(line, sizeof(line), f);
+            fclose(f);
+            vendor_id = strtoul(line, NULL, 16);
+            snprintf(filename, PATH_MAX, USBSYSBUS_PATH "/devices/%s/idProduct", de->d_name);
+            f = fopen(filename, "r");
+            if (!f) {
+                term_printf("Could not open %s\n", filename);
+                goto the_end;
+            }
+            fgets(line, sizeof(line), f);
+            fclose(f);
+            product_id = strtoul(line, NULL, 16);
+            snprintf(filename, PATH_MAX, USBSYSBUS_PATH "/devices/%s/product", de->d_name);
+            f = fopen(filename, "r");
+            if (f) {
+                fgets(line, sizeof(line), f);
+                fclose(f);
+                if (strlen(line) > 0)
+                    line[strlen(line) - 1] = '\0';
+
+                pstrcpy(product_name, sizeof(product_name), line);
+            } else
+                *product_name = 0;
+
+            snprintf(filename, PATH_MAX, USBSYSBUS_PATH "/devices/%s/speed", de->d_name);
+            f = fopen(filename, "r");
+            if (!f) {
+                term_printf("Could not open %s\n", filename);
+                goto the_end;
+            }
+            fgets(line, sizeof(line), f);
+            fclose(f);
+            if (!strcmp(line, "480\n"))
+                speed = USB_SPEED_HIGH;
+            else if (!strcmp(line, "1.5\n"))
+                speed = USB_SPEED_LOW;
+            else
+                speed = USB_SPEED_FULL;
+
+            ret = func(opaque, bus_num, addr, class_id, vendor_id,
+                       product_id, product_name, speed);
+            if (ret)
+                goto the_end;
+        }
+    }
+ the_end:
+    if (dir) closedir(dir);
+    return ret;
+}
+
+/*
+ * Determine how to access the host's USB devices and call the
+ * specific support function.
+ */
+static int usb_host_scan(void *opaque, USBScanFunc *func)
+{
+    FILE *f = 0;
+    DIR *dir = 0;
+    int ret = 0;
+    const char *devices = "/devices";
+    const char *trying = "husb: trying to open %s%s\n";
+    const char *failed = "husb: could not open %s%s\n";
+    char devpath[PATH_MAX];
+
+    /* only check the host once */
+    if (!usb_fs_type) {
+        /* test for dev file-system access in /proc/ */
+        dprintf(trying, USBPROCBUS_PATH, devices);
+        f = fopen(USBPROCBUS_PATH "/devices", "r");
+        if (!f) {
+            dprintf(failed, USBPROCBUS_PATH, devices);
+            /* maybe it has been moved to the /dev/ base */
+            dprintf(trying, USBDEVBUS_PATH, devices);
+            f = fopen(USBDEVBUS_PATH "/devices", "r");
+            if (!f) {
+                dprintf(failed, USBDEVBUS_PATH, devices);
+                /* test for newer sys file-system access */
+                dprintf(trying, USBSYSBUS_PATH, devices);
+                dir = opendir(USBSYSBUS_PATH "/devices");
+                if (!dir) {
+                    dprintf(failed, USBSYSBUS_PATH, devices);
+                    goto the_end;
+                } else {
+                    /* devices found in /dev/bus/usb/ (yes - not a mistake!) */
+                    strcpy(devpath, USBDEVBUS_PATH);
+                    usb_fs_type = USB_FS_SYS;
+                }
+                if (dir) closedir(dir);
+            } else {
+                /* devices found in /dev/bus/usb/ */
+                strcpy(devpath, USBDEVBUS_PATH);
+                usb_fs_type = USB_FS_DEV;
+            }
+        } else {
+            /* devices found in /proc/bus/usb/ */
+            strcpy(devpath, USBPROCBUS_PATH);
+            usb_fs_type = USB_FS_PROC;
+        }
+        if (f) fclose(f);
+
+        /* the module setting (used later for opening devices) */
+        usb_host_device_path = qemu_mallocz(strlen(devpath)+1);
+        if (usb_host_device_path) {
+            strcpy(usb_host_device_path, devpath);
+            term_printf("husb: using %s\n", usb_host_device_path);
+        } else {
+            /* out of memory? */
+            perror("husb: unable to allocate memory for device path");
+            goto the_end;
+        }
+    }
+
+    switch (usb_fs_type) {
+        case USB_FS_PROC:
+        case USB_FS_DEV:
+            ret = usb_host_scan_dev(opaque, func);
+            break;
+        case USB_FS_SYS:
+            ret = usb_host_scan_sys(opaque, func);
+            break;
     }
  the_end:
-    fclose(f);
     return ret;
 }