// SPDX-License-Identifier: GPL-2.0+ /* * Copyright (C) 2003-2008 Takahiro Hirofuchi */ #include <linux/string.h> #include <linux/module.h> #include <linux/device.h> #include "usbip_common.h" #include "stub.h" #define DRIVER_AUTHOR "Takahiro Hirofuchi" #define DRIVER_DESC "USB/IP Host Driver" struct kmem_cache *stub_priv_cache; /* * busid_tables defines matching busids that usbip can grab. A user can change * dynamically what device is locally used and what device is exported to a * remote host. */ #define MAX_BUSID 16 static struct bus_id_priv busid_table[MAX_BUSID]; static spinlock_t busid_table_lock; static void init_busid_table(void) { int i; /* * This also sets the bus_table[i].status to * STUB_BUSID_OTHER, which is 0. */ memset(busid_table, 0, sizeof(busid_table)); spin_lock_init(&busid_table_lock); for (i = 0; i < MAX_BUSID; i++) spin_lock_init(&busid_table[i].busid_lock); } /* * Find the index of the busid by name. * Must be called with busid_table_lock held. */ static int get_busid_idx(const char *busid) { int i; int idx = -1; for (i = 0; i < MAX_BUSID; i++) { spin_lock(&busid_table[i].busid_lock); if (busid_table[i].name[0]) if (!strncmp(busid_table[i].name, busid, BUSID_SIZE)) { idx = i; spin_unlock(&busid_table[i].busid_lock); break; } spin_unlock(&busid_table[i].busid_lock); } return idx; } /* Returns holding busid_lock. Should call put_busid_priv() to unlock */ struct bus_id_priv *get_busid_priv(const char *busid) { int idx; struct bus_id_priv *bid = NULL; spin_lock(&busid_table_lock); idx = get_busid_idx(busid); if (idx >= 0) { bid = &(busid_table[idx]); /* get busid_lock before returning */ spin_lock(&bid->busid_lock); } spin_unlock(&busid_table_lock); return bid; } void put_busid_priv(struct bus_id_priv *bid) { if (bid) spin_unlock(&bid->busid_lock); } static int add_match_busid(char *busid) { int i; int ret = -1; spin_lock(&busid_table_lock); /* already registered? */ if (get_busid_idx(busid) >= 0) { ret = 0; goto out; } for (i = 0; i < MAX_BUSID; i++) { spin_lock(&busid_table[i].busid_lock); if (!busid_table[i].name[0]) { strlcpy(busid_table[i].name, busid, BUSID_SIZE); if ((busid_table[i].status != STUB_BUSID_ALLOC) && (busid_table[i].status != STUB_BUSID_REMOV)) busid_table[i].status = STUB_BUSID_ADDED; ret = 0; spin_unlock(&busid_table[i].busid_lock); break; } spin_unlock(&busid_table[i].busid_lock); } out: spin_unlock(&busid_table_lock); return ret; } int del_match_busid(char *busid) { int idx; int ret = -1; spin_lock(&busid_table_lock); idx = get_busid_idx(busid); if (idx < 0) goto out; /* found */ ret = 0; spin_lock(&busid_table[idx].busid_lock); if (busid_table[idx].status == STUB_BUSID_OTHER) memset(busid_table[idx].name, 0, BUSID_SIZE); if ((busid_table[idx].status != STUB_BUSID_OTHER) && (busid_table[idx].status != STUB_BUSID_ADDED)) busid_table[idx].status = STUB_BUSID_REMOV; spin_unlock(&busid_table[idx].busid_lock); out: spin_unlock(&busid_table_lock); return ret; } static ssize_t match_busid_show(struct device_driver *drv, char *buf) { int i; char *out = buf; spin_lock(&busid_table_lock); for (i = 0; i < MAX_BUSID; i++) { spin_lock(&busid_table[i].busid_lock); if (busid_table[i].name[0]) out += sprintf(out, "%s ", busid_table[i].name); spin_unlock(&busid_table[i].busid_lock); } spin_unlock(&busid_table_lock); out += sprintf(out, "\n"); return out - buf; } static ssize_t match_busid_store(struct device_driver *dev, const char *buf, size_t count) { int len; char busid[BUSID_SIZE]; if (count < 5) return -EINVAL; /* busid needs to include \0 termination */ len = strlcpy(busid, buf + 4, BUSID_SIZE); if (sizeof(busid) <= len) return -EINVAL; if (!strncmp(buf, "add ", 4)) { if (add_match_busid(busid) < 0) return -ENOMEM; pr_debug("add busid %s\n", busid); return count; } if (!strncmp(buf, "del ", 4)) { if (del_match_busid(busid) < 0) return -ENODEV; pr_debug("del busid %s\n", busid); return count; } return -EINVAL; } static DRIVER_ATTR_RW(match_busid); static int do_rebind(char *busid, struct bus_id_priv *busid_priv) { int ret; /* device_attach() callers should hold parent lock for USB */ if (busid_priv->udev->dev.parent) device_lock(busid_priv->udev->dev.parent); ret = device_attach(&busid_priv->udev->dev); if (busid_priv->udev->dev.parent) device_unlock(busid_priv->udev->dev.parent); if (ret < 0) { dev_err(&busid_priv->udev->dev, "rebind failed\n"); return ret; } return 0; } static void stub_device_rebind(void) { #if IS_MODULE(CONFIG_USBIP_HOST) struct bus_id_priv *busid_priv; int i; /* update status to STUB_BUSID_OTHER so probe ignores the device */ spin_lock(&busid_table_lock); for (i = 0; i < MAX_BUSID; i++) { if (busid_table[i].name[0] && busid_table[i].shutdown_busid) { busid_priv = &(busid_table[i]); busid_priv->status = STUB_BUSID_OTHER; } } spin_unlock(&busid_table_lock); /* now run rebind - no need to hold locks. driver files are removed */ for (i = 0; i < MAX_BUSID; i++) { if (busid_table[i].name[0] && busid_table[i].shutdown_busid) { busid_priv = &(busid_table[i]); do_rebind(busid_table[i].name, busid_priv); } } #endif } static ssize_t rebind_store(struct device_driver *dev, const char *buf, size_t count) { int ret; int len; struct bus_id_priv *bid; /* buf length should be less that BUSID_SIZE */ len = strnlen(buf, BUSID_SIZE); if (!(len < BUSID_SIZE)) return -EINVAL; bid = get_busid_priv(buf); if (!bid) return -ENODEV; /* mark the device for deletion so probe ignores it during rescan */ bid->status = STUB_BUSID_OTHER; /* release the busid lock */ put_busid_priv(bid); ret = do_rebind((char *) buf, bid); if (ret < 0) return ret; /* delete device from busid_table */ del_match_busid((char *) buf); return count; } static DRIVER_ATTR_WO(rebind); static struct stub_priv *stub_priv_pop_from_listhead(struct list_head *listhead) { struct stub_priv *priv, *tmp; list_for_each_entry_safe(priv, tmp, listhead, list) { list_del(&priv->list); return priv; } return NULL; } static struct stub_priv *stub_priv_pop(struct stub_device *sdev) { unsigned long flags; struct stub_priv *priv; spin_lock_irqsave(&sdev->priv_lock, flags); priv = stub_priv_pop_from_listhead(&sdev->priv_init); if (priv) goto done; priv = stub_priv_pop_from_listhead(&sdev->priv_tx); if (priv) goto done; priv = stub_priv_pop_from_listhead(&sdev->priv_free); done: spin_unlock_irqrestore(&sdev->priv_lock, flags); return priv; } void stub_device_cleanup_urbs(struct stub_device *sdev) { struct stub_priv *priv; struct urb *urb; dev_dbg(&sdev->udev->dev, "Stub device cleaning up urbs\n"); while ((priv = stub_priv_pop(sdev))) { urb = priv->urb; dev_dbg(&sdev->udev->dev, "free urb seqnum %lu\n", priv->seqnum); usb_kill_urb(urb); kmem_cache_free(stub_priv_cache, priv); kfree(urb->transfer_buffer); urb->transfer_buffer = NULL; kfree(urb->setup_packet); urb->setup_packet = NULL; usb_free_urb(urb); } } static int __init usbip_host_init(void) { int ret; init_busid_table(); stub_priv_cache = KMEM_CACHE(stub_priv, SLAB_HWCACHE_ALIGN); if (!stub_priv_cache) { pr_err("kmem_cache_create failed\n"); return -ENOMEM; } ret = usb_register_device_driver(&stub_driver, THIS_MODULE); if (ret) { pr_err("usb_register failed %d\n", ret); goto err_usb_register; } ret = driver_create_file(&stub_driver.drvwrap.driver, &driver_attr_match_busid); if (ret) { pr_err("driver_create_file failed\n"); goto err_create_file; } ret = driver_create_file(&stub_driver.drvwrap.driver, &driver_attr_rebind); if (ret) { pr_err("driver_create_file failed\n"); goto err_create_file; } return ret; err_create_file: usb_deregister_device_driver(&stub_driver); err_usb_register: kmem_cache_destroy(stub_priv_cache); return ret; } static void __exit usbip_host_exit(void) { driver_remove_file(&stub_driver.drvwrap.driver, &driver_attr_match_busid); driver_remove_file(&stub_driver.drvwrap.driver, &driver_attr_rebind); /* * deregister() calls stub_disconnect() for all devices. Device * specific data is cleared in stub_disconnect(). */ usb_deregister_device_driver(&stub_driver); /* initiate scan to attach devices */ stub_device_rebind(); kmem_cache_destroy(stub_priv_cache); } module_init(usbip_host_init); module_exit(usbip_host_exit); MODULE_AUTHOR(DRIVER_AUTHOR); MODULE_DESCRIPTION(DRIVER_DESC); MODULE_LICENSE("GPL");