/* * u_ether.c -- Ethernet-over-USB link layer utilities for Gadget stack * * Copyright (C) 2003-2005,2008 David Brownell * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger * Copyright (C) 2008 Nokia Corporation * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. */ /* #define VERBOSE_DEBUG */ #include #include #include #include #include #include #include "u_ether.h" /* * This component encapsulates the Ethernet link glue needed to provide * one (!) network link through the USB gadget stack, normally "usb0". * * The control and data models are handled by the function driver which * connects to this code; such as CDC Ethernet (ECM or EEM), * "CDC Subset", or RNDIS. That includes all descriptor and endpoint * management. * * Link level addressing is handled by this component using module * parameters; if no such parameters are provided, random link level * addresses are used. Each end of the link uses one address. The * host end address is exported in various ways, and is often recorded * in configuration databases. * * The driver which assembles each configuration using such a link is * responsible for ensuring that each configuration includes at most one * instance of is network link. (The network layer provides ways for * this single "physical" link to be used by multiple virtual links.) */ #define UETH__VERSION "29-May-2008" static struct workqueue_struct *uether_wq; struct eth_dev { /* lock is held while accessing port_usb * or updating its backlink port_usb->ioport */ spinlock_t lock; struct gether *port_usb; struct net_device *net; struct usb_gadget *gadget; spinlock_t req_lock; /* guard {rx,tx}_reqs */ struct list_head tx_reqs, rx_reqs; unsigned tx_qlen; /* Minimum number of TX USB request queued to UDC */ #define TX_REQ_THRESHOLD 5 int no_tx_req_used; int tx_skb_hold_count; u32 tx_req_bufsize; struct sk_buff_head rx_frames; unsigned header_len; unsigned int ul_max_pkts_per_xfer; unsigned int dl_max_pkts_per_xfer; bool rx_trigger_enabled; struct sk_buff *(*wrap)(struct gether *, struct sk_buff *skb); int (*unwrap)(struct gether *, struct sk_buff *skb, struct sk_buff_head *list); struct work_struct work; struct work_struct rx_work; unsigned long todo; #define WORK_RX_MEMORY 0 bool zlp; u8 host_mac[ETH_ALEN]; }; /*-------------------------------------------------------------------------*/ #define RX_EXTRA 20 /* bytes guarding against rx overflows */ #define DEFAULT_QLEN 2 /* double buffering by default */ static unsigned qmult = 10; module_param(qmult, uint, S_IRUGO|S_IWUSR); MODULE_PARM_DESC(qmult, "queue length multiplier at high/super speed"); /* for dual-speed hardware, use deeper queues at high/super speed */ static inline int qlen(struct usb_gadget *gadget) { if (gadget_is_dualspeed(gadget) && (gadget->speed == USB_SPEED_HIGH || gadget->speed == USB_SPEED_SUPER)) return qmult * DEFAULT_QLEN; else return DEFAULT_QLEN; } /*-------------------------------------------------------------------------*/ /* REVISIT there must be a better way than having two sets * of debug calls ... */ #undef DBG #undef VDBG #undef ERROR #undef INFO #define xprintk(d, level, fmt, args...) \ printk(level "%s: " fmt , (d)->net->name , ## args) #ifdef DEBUG #undef DEBUG #define DBG(dev, fmt, args...) \ xprintk(dev , KERN_DEBUG , fmt , ## args) #else #define DBG(dev, fmt, args...) \ do { } while (0) #endif /* DEBUG */ #ifdef VERBOSE_DEBUG #define VDBG DBG #else #define VDBG(dev, fmt, args...) \ do { } while (0) #endif /* DEBUG */ #define ERROR(dev, fmt, args...) \ xprintk(dev , KERN_ERR , fmt , ## args) #define INFO(dev, fmt, args...) \ xprintk(dev , KERN_INFO , fmt , ## args) /*-------------------------------------------------------------------------*/ /* NETWORK DRIVER HOOKUP (to the layer above this driver) */ static int ueth_change_mtu(struct net_device *net, int new_mtu) { struct eth_dev *dev = netdev_priv(net); unsigned long flags; int status = 0; /* don't change MTU on "live" link (peer won't know) */ spin_lock_irqsave(&dev->lock, flags); if (dev->port_usb) status = -EBUSY; else if (new_mtu <= ETH_HLEN || new_mtu > ETH_FRAME_LEN) status = -ERANGE; else net->mtu = new_mtu; spin_unlock_irqrestore(&dev->lock, flags); return status; } static void eth_get_drvinfo(struct net_device *net, struct ethtool_drvinfo *p) { struct eth_dev *dev = netdev_priv(net); strlcpy(p->driver, "g_ether", sizeof p->driver); strlcpy(p->version, UETH__VERSION, sizeof p->version); strlcpy(p->fw_version, dev->gadget->name, sizeof p->fw_version); strlcpy(p->bus_info, dev_name(&dev->gadget->dev), sizeof p->bus_info); } /* REVISIT can also support: * - WOL (by tracking suspends and issuing remote wakeup) * - msglevel (implies updated messaging) * - ... probably more ethtool ops */ static const struct ethtool_ops ops = { .get_drvinfo = eth_get_drvinfo, .get_link = ethtool_op_get_link, }; static void defer_kevent(struct eth_dev *dev, int flag) { if (test_and_set_bit(flag, &dev->todo)) return; if (!schedule_work(&dev->work)) ERROR(dev, "kevent %d may have been dropped\n", flag); else DBG(dev, "kevent %d scheduled\n", flag); } static void rx_complete(struct usb_ep *ep, struct usb_request *req); static void tx_complete(struct usb_ep *ep, struct usb_request *req); static int rx_submit(struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags) { struct sk_buff *skb; int retval = -ENOMEM; size_t size = 0; struct usb_ep *out; unsigned long flags; spin_lock_irqsave(&dev->lock, flags); if (dev->port_usb) out = dev->port_usb->out_ep; else out = NULL; spin_unlock_irqrestore(&dev->lock, flags); if (!out) return -ENOTCONN; /* Padding up to RX_EXTRA handles minor disagreements with host. * Normally we use the USB "terminate on short read" convention; * so allow up to (N*maxpacket), since that memory is normally * already allocated. Some hardware doesn't deal well with short * reads (e.g. DMA must be N*maxpacket), so for now don't trim a * byte off the end (to force hardware errors on overflow). * * RNDIS uses internal framing, and explicitly allows senders to * pad to end-of-packet. That's potentially nice for speed, but * means receivers can't recover lost synch on their own (because * new packets don't only start after a short RX). */ size += sizeof(struct ethhdr) + dev->net->mtu + RX_EXTRA; size += dev->port_usb->header_len; size += out->maxpacket - 1; size -= size % out->maxpacket; if (dev->ul_max_pkts_per_xfer) size *= dev->ul_max_pkts_per_xfer; if (dev->port_usb->is_fixed) size = max_t(size_t, size, dev->port_usb->fixed_out_len); pr_debug("%s: size: %d", __func__, size); skb = alloc_skb(size + NET_IP_ALIGN, gfp_flags); if (skb == NULL) { DBG(dev, "no rx skb\n"); goto enomem; } /* Some platforms perform better when IP packets are aligned, * but on at least one, checksumming fails otherwise. Note: * RNDIS headers involve variable numbers of LE32 values. */ skb_reserve(skb, NET_IP_ALIGN); req->buf = skb->data; req->length = size; req->context = skb; retval = usb_ep_queue(out, req, gfp_flags); if (retval == -ENOMEM) enomem: defer_kevent(dev, WORK_RX_MEMORY); if (retval) { DBG(dev, "rx submit --> %d\n", retval); if (skb) dev_kfree_skb_any(skb); } return retval; } static void rx_complete(struct usb_ep *ep, struct usb_request *req) { struct sk_buff *skb = req->context; struct eth_dev *dev = ep->driver_data; int status = req->status; bool queue = 0; switch (status) { /* normal completion */ case 0: skb_put(skb, req->actual); if (dev->unwrap) { unsigned long flags; spin_lock_irqsave(&dev->lock, flags); if (dev->port_usb) { status = dev->unwrap(dev->port_usb, skb, &dev->rx_frames); if (status == -EINVAL) dev->net->stats.rx_errors++; else if (status == -EOVERFLOW) dev->net->stats.rx_over_errors++; } else { dev_kfree_skb_any(skb); status = -ENOTCONN; } spin_unlock_irqrestore(&dev->lock, flags); } else { skb_queue_tail(&dev->rx_frames, skb); } if (!status) queue = 1; break; /* software-driven interface shutdown */ case -ECONNRESET: /* unlink */ case -ESHUTDOWN: /* disconnect etc */ VDBG(dev, "rx shutdown, code %d\n", status); goto quiesce; /* for hardware automagic (such as pxa) */ case -ECONNABORTED: /* endpoint reset */ DBG(dev, "rx %s reset\n", ep->name); defer_kevent(dev, WORK_RX_MEMORY); quiesce: dev_kfree_skb_any(skb); goto clean; /* data overrun */ case -EOVERFLOW: dev->net->stats.rx_over_errors++; /* FALLTHROUGH */ default: queue = 1; dev_kfree_skb_any(skb); dev->net->stats.rx_errors++; DBG(dev, "rx status %d\n", status); break; } clean: spin_lock(&dev->req_lock); list_add(&req->list, &dev->rx_reqs); spin_unlock(&dev->req_lock); if (queue) queue_work(uether_wq, &dev->rx_work); } static int prealloc(struct list_head *list, struct usb_ep *ep, unsigned n) { unsigned i; struct usb_request *req; bool usb_in; if (!n) return -ENOMEM; /* queue/recycle up to N requests */ i = n; list_for_each_entry(req, list, list) { if (i-- == 0) goto extra; } if (ep->desc->bEndpointAddress & USB_DIR_IN) usb_in = true; else usb_in = false; while (i--) { req = usb_ep_alloc_request(ep, GFP_ATOMIC); if (!req) return list_empty(list) ? -ENOMEM : 0; /* update completion handler */ if (usb_in) req->complete = tx_complete; else req->complete = rx_complete; list_add(&req->list, list); } return 0; extra: /* free extras */ for (;;) { struct list_head *next; next = req->list.next; list_del(&req->list); usb_ep_free_request(ep, req); if (next == list) break; req = container_of(next, struct usb_request, list); } return 0; } static int alloc_requests(struct eth_dev *dev, struct gether *link, unsigned n) { int status; spin_lock(&dev->req_lock); status = prealloc(&dev->tx_reqs, link->in_ep, n); if (status < 0) goto fail; status = prealloc(&dev->rx_reqs, link->out_ep, n); if (status < 0) goto fail; goto done; fail: DBG(dev, "can't alloc requests\n"); done: spin_unlock(&dev->req_lock); return status; } static void rx_fill(struct eth_dev *dev, gfp_t gfp_flags) { struct usb_request *req; unsigned long flags; int req_cnt = 0; /* fill unused rxq slots with some skb */ spin_lock_irqsave(&dev->req_lock, flags); while (!list_empty(&dev->rx_reqs)) { /* break the nexus of continuous completion and re-submission*/ if (++req_cnt > qlen(dev->gadget)) break; req = container_of(dev->rx_reqs.next, struct usb_request, list); list_del_init(&req->list); spin_unlock_irqrestore(&dev->req_lock, flags); if (rx_submit(dev, req, gfp_flags) < 0) { spin_lock_irqsave(&dev->req_lock, flags); list_add(&req->list, &dev->rx_reqs); spin_unlock_irqrestore(&dev->req_lock, flags); defer_kevent(dev, WORK_RX_MEMORY); return; } spin_lock_irqsave(&dev->req_lock, flags); } spin_unlock_irqrestore(&dev->req_lock, flags); } static void process_rx_w(struct work_struct *work) { struct eth_dev *dev = container_of(work, struct eth_dev, rx_work); struct sk_buff *skb; int status = 0; if (!dev->port_usb) return; while ((skb = skb_dequeue(&dev->rx_frames))) { if (status < 0 || ETH_HLEN > skb->len || skb->len > ETH_FRAME_LEN) { dev->net->stats.rx_errors++; dev->net->stats.rx_length_errors++; DBG(dev, "rx length %d\n", skb->len); dev_kfree_skb_any(skb); continue; } skb->protocol = eth_type_trans(skb, dev->net); dev->net->stats.rx_packets++; dev->net->stats.rx_bytes += skb->len; status = netif_rx_ni(skb); } if (netif_running(dev->net)) rx_fill(dev, GFP_KERNEL); } static void eth_work(struct work_struct *work) { struct eth_dev *dev = container_of(work, struct eth_dev, work); if (test_and_clear_bit(WORK_RX_MEMORY, &dev->todo)) { if (netif_running(dev->net)) rx_fill(dev, GFP_KERNEL); } if (dev->todo) DBG(dev, "work done, flags = 0x%lx\n", dev->todo); } static void tx_complete(struct usb_ep *ep, struct usb_request *req) { struct sk_buff *skb; struct eth_dev *dev; struct net_device *net; struct usb_request *new_req; struct usb_ep *in; int length; int retval; if (!ep->driver_data) { usb_ep_free_request(ep, req); return; } dev = ep->driver_data; net = dev->net; if (!dev->port_usb) { usb_ep_free_request(ep, req); return; } switch (req->status) { default: dev->net->stats.tx_errors++; VDBG(dev, "tx err %d\n", req->status); /* FALLTHROUGH */ case -ECONNRESET: /* unlink */ case -ESHUTDOWN: /* disconnect etc */ break; case 0: if (!req->zero) dev->net->stats.tx_bytes += req->length-1; else dev->net->stats.tx_bytes += req->length; } dev->net->stats.tx_packets++; spin_lock(&dev->req_lock); list_add_tail(&req->list, &dev->tx_reqs); if (dev->port_usb->multi_pkt_xfer) { dev->no_tx_req_used--; req->length = 0; in = dev->port_usb->in_ep; if (!list_empty(&dev->tx_reqs)) { new_req = container_of(dev->tx_reqs.next, struct usb_request, list); list_del(&new_req->list); spin_unlock(&dev->req_lock); if (new_req->length > 0) { length = new_req->length; /* NCM requires no zlp if transfer is * dwNtbInMaxSize */ if (dev->port_usb->is_fixed && length == dev->port_usb->fixed_in_len && (length % in->maxpacket) == 0) new_req->zero = 0; else new_req->zero = 1; /* use zlp framing on tx for strict CDC-Ether * conformance, though any robust network rx * path ignores extra padding. and some hardware * doesn't like to write zlps. */ if (new_req->zero && !dev->zlp && (length % in->maxpacket) == 0) { new_req->zero = 0; length++; } new_req->length = length; retval = usb_ep_queue(in, new_req, GFP_ATOMIC); switch (retval) { default: DBG(dev, "tx queue err %d\n", retval); new_req->length = 0; spin_lock(&dev->req_lock); list_add_tail(&new_req->list, &dev->tx_reqs); spin_unlock(&dev->req_lock); break; case 0: spin_lock(&dev->req_lock); dev->no_tx_req_used++; spin_unlock(&dev->req_lock); net->trans_start = jiffies; } } else { spin_lock(&dev->req_lock); /* * Put the idle request at the back of the * queue. The xmit function will put the * unfinished request at the beginning of the * queue. */ list_add_tail(&new_req->list, &dev->tx_reqs); spin_unlock(&dev->req_lock); } } else { spin_unlock(&dev->req_lock); } } else { skb = req->context; spin_unlock(&dev->req_lock); dev_kfree_skb_any(skb); } if (netif_carrier_ok(dev->net)) netif_wake_queue(dev->net); } static inline int is_promisc(u16 cdc_filter) { return cdc_filter & USB_CDC_PACKET_TYPE_PROMISCUOUS; } static int alloc_tx_buffer(struct eth_dev *dev) { struct list_head *act; struct usb_request *req; dev->tx_req_bufsize = (dev->dl_max_pkts_per_xfer * (dev->net->mtu + sizeof(struct ethhdr) /* size of rndis_packet_msg_type */ + 44 + 22)); list_for_each(act, &dev->tx_reqs) { req = container_of(act, struct usb_request, list); if (!req->buf) req->buf = kzalloc(dev->tx_req_bufsize, GFP_ATOMIC); if (!req->buf) goto free_buf; } return 0; free_buf: /* tx_req_bufsize = 0 retries mem alloc on next eth_start_xmit */ dev->tx_req_bufsize = 0; list_for_each(act, &dev->tx_reqs) { req = container_of(act, struct usb_request, list); kfree(req->buf); } return -ENOMEM; } static netdev_tx_t eth_start_xmit(struct sk_buff *skb, struct net_device *net) { struct eth_dev *dev = netdev_priv(net); int length = skb->len; int retval; struct usb_request *req = NULL; unsigned long flags; struct usb_ep *in; u16 cdc_filter; bool multi_pkt_xfer = false; spin_lock_irqsave(&dev->lock, flags); if (dev->port_usb) { in = dev->port_usb->in_ep; cdc_filter = dev->port_usb->cdc_filter; multi_pkt_xfer = dev->port_usb->multi_pkt_xfer; } else { in = NULL; cdc_filter = 0; } spin_unlock_irqrestore(&dev->lock, flags); if (!in) { dev_kfree_skb_any(skb); return NETDEV_TX_OK; } /* Allocate memory for tx_reqs to support multi packet transfer */ if (multi_pkt_xfer && !dev->tx_req_bufsize) { retval = alloc_tx_buffer(dev); if (retval < 0) return -ENOMEM; } /* apply outgoing CDC or RNDIS filters */ if (!is_promisc(cdc_filter)) { u8 *dest = skb->data; if (is_multicast_ether_addr(dest)) { u16 type; /* ignores USB_CDC_PACKET_TYPE_MULTICAST and host * SET_ETHERNET_MULTICAST_FILTERS requests */ if (is_broadcast_ether_addr(dest)) type = USB_CDC_PACKET_TYPE_BROADCAST; else type = USB_CDC_PACKET_TYPE_ALL_MULTICAST; if (!(cdc_filter & type)) { dev_kfree_skb_any(skb); return NETDEV_TX_OK; } } /* ignores USB_CDC_PACKET_TYPE_DIRECTED */ } spin_lock_irqsave(&dev->req_lock, flags); /* * this freelist can be empty if an interrupt triggered disconnect() * and reconfigured the gadget (shutting down this queue) after the * network stack decided to xmit but before we got the spinlock. */ if (list_empty(&dev->tx_reqs)) { spin_unlock_irqrestore(&dev->req_lock, flags); return NETDEV_TX_BUSY; } req = container_of(dev->tx_reqs.next, struct usb_request, list); list_del(&req->list); /* temporarily stop TX queue when the freelist empties */ if (list_empty(&dev->tx_reqs)) netif_stop_queue(net); spin_unlock_irqrestore(&dev->req_lock, flags); /* no buffer copies needed, unless the network stack did it * or the hardware can't use skb buffers. * or there's not enough space for extra headers we need */ spin_lock_irqsave(&dev->lock, flags); if (dev->wrap) { if (dev->port_usb) skb = dev->wrap(dev->port_usb, skb); if (!skb) { spin_unlock_irqrestore(&dev->lock, flags); goto drop; } } if (multi_pkt_xfer) { pr_debug("req->length:%d header_len:%u\n" "skb->len:%d skb->data_len:%d\n", req->length, dev->header_len, skb->len, skb->data_len); /* Add RNDIS Header */ memcpy(req->buf + req->length, dev->port_usb->header, dev->header_len); /* Increment req length by header size */ req->length += dev->header_len; spin_unlock_irqrestore(&dev->lock, flags); /* Copy received IP data from SKB */ memcpy(req->buf + req->length, skb->data, skb->len); /* Increment req length by skb data length */ req->length += skb->len; length = req->length; dev_kfree_skb_any(skb); spin_lock_irqsave(&dev->req_lock, flags); dev->tx_skb_hold_count++; if (dev->tx_skb_hold_count < dev->dl_max_pkts_per_xfer) { if (dev->no_tx_req_used > TX_REQ_THRESHOLD) { list_add(&req->list, &dev->tx_reqs); spin_unlock_irqrestore(&dev->req_lock, flags); goto success; } } dev->no_tx_req_used++; dev->tx_skb_hold_count = 0; spin_unlock_irqrestore(&dev->req_lock, flags); } else { spin_unlock_irqrestore(&dev->lock, flags); length = skb->len; req->buf = skb->data; req->context = skb; } /* NCM requires no zlp if transfer is dwNtbInMaxSize */ if (dev->port_usb->is_fixed && length == dev->port_usb->fixed_in_len && (length % in->maxpacket) == 0) req->zero = 0; else req->zero = 1; /* use zlp framing on tx for strict CDC-Ether conformance, * though any robust network rx path ignores extra padding. * and some hardware doesn't like to write zlps. */ if (req->zero && !dev->zlp && (length % in->maxpacket) == 0) { req->zero = 0; length++; } req->length = length; /* throttle highspeed IRQ rate back slightly */ if (gadget_is_dualspeed(dev->gadget) && (dev->gadget->speed == USB_SPEED_HIGH)) { dev->tx_qlen++; if (dev->tx_qlen == (qmult/2)) { req->no_interrupt = 0; dev->tx_qlen = 0; } else { req->no_interrupt = 1; } } else { req->no_interrupt = 0; } retval = usb_ep_queue(in, req, GFP_ATOMIC); switch (retval) { default: DBG(dev, "tx queue err %d\n", retval); break; case 0: net->trans_start = jiffies; } if (retval) { if (!multi_pkt_xfer) dev_kfree_skb_any(skb); else req->length = 0; drop: dev->net->stats.tx_dropped++; spin_lock_irqsave(&dev->req_lock, flags); if (list_empty(&dev->tx_reqs)) netif_start_queue(net); list_add_tail(&req->list, &dev->tx_reqs); spin_unlock_irqrestore(&dev->req_lock, flags); } success: return NETDEV_TX_OK; } /*-------------------------------------------------------------------------*/ static void eth_start(struct eth_dev *dev, gfp_t gfp_flags) { DBG(dev, "%s\n", __func__); /* fill the rx queue */ rx_fill(dev, gfp_flags); /* and open the tx floodgates */ dev->tx_qlen = 0; netif_wake_queue(dev->net); } static int eth_open(struct net_device *net) { struct eth_dev *dev = netdev_priv(net); struct gether *link; bool wait_for_rx_trigger; DBG(dev, "%s\n", __func__); spin_lock_irq(&dev->lock); link = dev->port_usb; spin_unlock_irq(&dev->lock); wait_for_rx_trigger = dev->rx_trigger_enabled && link && !link->rx_triggered; if (netif_carrier_ok(dev->net) && !wait_for_rx_trigger) eth_start(dev, GFP_KERNEL); spin_lock_irq(&dev->lock); if (link && link->open) link->open(link); spin_unlock_irq(&dev->lock); return 0; } static int eth_stop(struct net_device *net) { struct eth_dev *dev = netdev_priv(net); unsigned long flags; VDBG(dev, "%s\n", __func__); netif_stop_queue(net); DBG(dev, "stop stats: rx/tx %ld/%ld, errs %ld/%ld\n", dev->net->stats.rx_packets, dev->net->stats.tx_packets, dev->net->stats.rx_errors, dev->net->stats.tx_errors ); /* ensure there are no more active requests */ spin_lock_irqsave(&dev->lock, flags); if (dev->port_usb) { struct gether *link = dev->port_usb; if (link->close) link->close(link); /* NOTE: we have no abort-queue primitive we could use * to cancel all pending I/O. Instead, we disable then * reenable the endpoints ... this idiom may leave toggle * wrong, but that's a self-correcting error. * * REVISIT: we *COULD* just let the transfers complete at * their own pace; the network stack can handle old packets. * For the moment we leave this here, since it works. */ usb_ep_disable(link->in_ep); usb_ep_disable(link->out_ep); if (netif_carrier_ok(net)) { if (config_ep_by_speed(dev->gadget, &link->func, link->in_ep) || config_ep_by_speed(dev->gadget, &link->func, link->out_ep)) { link->in_ep->desc = NULL; link->out_ep->desc = NULL; return -EINVAL; } DBG(dev, "host still using in/out endpoints\n"); usb_ep_enable(link->in_ep); usb_ep_enable(link->out_ep); } } spin_unlock_irqrestore(&dev->lock, flags); return 0; } /*-------------------------------------------------------------------------*/ /* initial value, changed by "ifconfig usb0 hw ether xx:xx:xx:xx:xx:xx" */ static char *dev_addr; module_param(dev_addr, charp, S_IRUGO); MODULE_PARM_DESC(dev_addr, "Device Ethernet Address"); /* this address is invisible to ifconfig */ static char *host_addr; module_param(host_addr, charp, S_IRUGO); MODULE_PARM_DESC(host_addr, "Host Ethernet Address"); static int get_ether_addr(const char *str, u8 *dev_addr) { if (str) { unsigned i; for (i = 0; i < 6; i++) { unsigned char num; if ((*str == '.') || (*str == ':')) str++; num = hex_to_bin(*str++) << 4; num |= hex_to_bin(*str++); dev_addr [i] = num; } if (is_valid_ether_addr(dev_addr)) return 0; } random_ether_addr(dev_addr); return 1; } static struct eth_dev *the_dev; static const struct net_device_ops eth_netdev_ops = { .ndo_open = eth_open, .ndo_stop = eth_stop, .ndo_start_xmit = eth_start_xmit, .ndo_change_mtu = ueth_change_mtu, .ndo_set_mac_address = eth_mac_addr, .ndo_validate_addr = eth_validate_addr, }; static struct device_type gadget_type = { .name = "gadget", }; /** * gether_setup - initialize one ethernet-over-usb link * @g: gadget to associated with these links * @ethaddr: NULL, or a buffer in which the ethernet address of the * host side of the link is recorded * Context: may sleep * * This sets up the single network link that may be exported by a * gadget driver using this framework. The link layer addresses are * set up using module parameters. * * Returns negative errno, or zero on success */ int gether_setup(struct usb_gadget *g, u8 ethaddr[ETH_ALEN]) { return gether_setup_name(g, ethaddr, "usb"); } /** * gether_setup_name - initialize one ethernet-over-usb link * @g: gadget to associated with these links * @ethaddr: NULL, or a buffer in which the ethernet address of the * host side of the link is recorded * @netname: name for network device (for example, "usb") * Context: may sleep * * This sets up the single network link that may be exported by a * gadget driver using this framework. The link layer addresses are * set up using module parameters. * * Returns negative errno, or zero on success */ int gether_setup_name(struct usb_gadget *g, u8 ethaddr[ETH_ALEN], const char *netname) { struct eth_dev *dev; struct net_device *net; int status; if (the_dev) return -EBUSY; net = alloc_etherdev(sizeof *dev); if (!net) return -ENOMEM; dev = netdev_priv(net); spin_lock_init(&dev->lock); spin_lock_init(&dev->req_lock); INIT_WORK(&dev->work, eth_work); INIT_WORK(&dev->rx_work, process_rx_w); INIT_LIST_HEAD(&dev->tx_reqs); INIT_LIST_HEAD(&dev->rx_reqs); skb_queue_head_init(&dev->rx_frames); /* network device setup */ dev->net = net; snprintf(net->name, sizeof(net->name), "%s%%d", netname); if (get_ether_addr(dev_addr, net->dev_addr)) dev_warn(&g->dev, "using random %s ethernet address\n", "self"); if (get_ether_addr(host_addr, dev->host_mac)) dev_warn(&g->dev, "using random %s ethernet address\n", "host"); if (ethaddr) memcpy(ethaddr, dev->host_mac, ETH_ALEN); net->netdev_ops = ð_netdev_ops; SET_ETHTOOL_OPS(net, &ops); /* two kinds of host-initiated state changes: * - iff DATA transfer is active, carrier is "on" * - tx queueing enabled if open *and* carrier is "on" */ netif_carrier_off(net); dev->gadget = g; SET_NETDEV_DEV(net, &g->dev); SET_NETDEV_DEVTYPE(net, &gadget_type); status = register_netdev(net); if (status < 0) { dev_dbg(&g->dev, "register_netdev failed, %d\n", status); free_netdev(net); } else { INFO(dev, "MAC %pM\n", net->dev_addr); INFO(dev, "HOST MAC %pM\n", dev->host_mac); the_dev = dev; } return status; } /** * gether_cleanup - remove Ethernet-over-USB device * Context: may sleep * * This is called to free all resources allocated by @gether_setup(). */ void gether_cleanup(void) { if (!the_dev) return; unregister_netdev(the_dev->net); flush_work_sync(&the_dev->work); free_netdev(the_dev->net); the_dev = NULL; } /** * gether_connect - notify network layer that USB link is active * @link: the USB link, set up with endpoints, descriptors matching * current device speed, and any framing wrapper(s) set up. * Context: irqs blocked * * This is called to activate endpoints and let the network layer know * the connection is active ("carrier detect"). It may cause the I/O * queues to open and start letting network packets flow, but will in * any case activate the endpoints so that they respond properly to the * USB host. * * Verify net_device pointer returned using IS_ERR(). If it doesn't * indicate some error code (negative errno), ep->driver_data values * have been overwritten. */ struct net_device *gether_connect(struct gether *link) { struct eth_dev *dev = the_dev; int result = 0; bool wait_for_rx_trigger; if (!dev) return ERR_PTR(-EINVAL); link->header = kzalloc(sizeof(struct rndis_packet_msg_type), GFP_ATOMIC); if (!link->header) { pr_err("RNDIS header memory allocation failed.\n"); result = -ENOMEM; goto fail; } link->in_ep->driver_data = dev; result = usb_ep_enable(link->in_ep); if (result != 0) { DBG(dev, "enable %s --> %d\n", link->in_ep->name, result); goto fail0; } link->out_ep->driver_data = dev; result = usb_ep_enable(link->out_ep); if (result != 0) { DBG(dev, "enable %s --> %d\n", link->out_ep->name, result); goto fail1; } if (result == 0) result = alloc_requests(dev, link, qlen(dev->gadget)); if (result == 0) { dev->zlp = link->is_zlp_ok; DBG(dev, "qlen %d\n", qlen(dev->gadget)); dev->header_len = link->header_len; dev->unwrap = link->unwrap; dev->wrap = link->wrap; dev->ul_max_pkts_per_xfer = link->ul_max_pkts_per_xfer; dev->dl_max_pkts_per_xfer = link->dl_max_pkts_per_xfer; dev->rx_trigger_enabled = link->rx_trigger_enabled; spin_lock(&dev->lock); dev->tx_skb_hold_count = 0; dev->no_tx_req_used = 0; dev->tx_req_bufsize = 0; dev->port_usb = link; link->ioport = dev; if (netif_running(dev->net)) { if (link->open) link->open(link); } else { if (link->close) link->close(link); } spin_unlock(&dev->lock); netif_carrier_on(dev->net); wait_for_rx_trigger = dev->rx_trigger_enabled && !link->rx_triggered; if (netif_running(dev->net) && !wait_for_rx_trigger) eth_start(dev, GFP_ATOMIC); /* on error, disable any endpoints */ } else { (void) usb_ep_disable(link->out_ep); fail1: (void) usb_ep_disable(link->in_ep); } /* caller is responsible for cleanup on error */ if (result < 0) { fail0: kfree(link->header); fail: return ERR_PTR(result); } return dev->net; } /** * gether_disconnect - notify network layer that USB link is inactive * @link: the USB link, on which gether_connect() was called * Context: irqs blocked * * This is called to deactivate endpoints and let the network layer know * the connection went inactive ("no carrier"). * * On return, the state is as if gether_connect() had never been called. * The endpoints are inactive, and accordingly without active USB I/O. * Pointers to endpoint descriptors and endpoint private data are nulled. */ void gether_disconnect(struct gether *link) { struct eth_dev *dev = link->ioport; struct usb_request *req; struct sk_buff *skb; if (!dev) return; DBG(dev, "%s\n", __func__); netif_stop_queue(dev->net); netif_carrier_off(dev->net); /* disable endpoints, forcing (synchronous) completion * of all pending i/o. then free the request objects * and forget about the endpoints. */ usb_ep_disable(link->in_ep); spin_lock(&dev->req_lock); while (!list_empty(&dev->tx_reqs)) { req = container_of(dev->tx_reqs.next, struct usb_request, list); list_del(&req->list); spin_unlock(&dev->req_lock); if (link->multi_pkt_xfer) kfree(req->buf); usb_ep_free_request(link->in_ep, req); spin_lock(&dev->req_lock); } /* Free rndis header buffer memory */ kfree(link->header); link->header = NULL; spin_unlock(&dev->req_lock); link->in_ep->driver_data = NULL; link->in_ep->desc = NULL; usb_ep_disable(link->out_ep); spin_lock(&dev->req_lock); while (!list_empty(&dev->rx_reqs)) { req = container_of(dev->rx_reqs.next, struct usb_request, list); list_del(&req->list); spin_unlock(&dev->req_lock); usb_ep_free_request(link->out_ep, req); spin_lock(&dev->req_lock); } spin_unlock(&dev->req_lock); spin_lock(&dev->rx_frames.lock); while ((skb = __skb_dequeue(&dev->rx_frames))) dev_kfree_skb_any(skb); spin_unlock(&dev->rx_frames.lock); link->out_ep->driver_data = NULL; link->out_ep->desc = NULL; /* finish forgetting about this USB link episode */ dev->header_len = 0; dev->unwrap = NULL; dev->wrap = NULL; dev->rx_trigger_enabled = 0; spin_lock(&dev->lock); dev->port_usb = NULL; link->ioport = NULL; spin_unlock(&dev->lock); } int gether_up(struct gether *link) { struct eth_dev *dev = link->ioport; if (dev && netif_carrier_ok(dev->net)) eth_start(dev, GFP_KERNEL); return 0; } static int __init gether_init(void) { uether_wq = create_singlethread_workqueue("uether"); if (!uether_wq) { pr_err("%s: Unable to create workqueue: uether\n", __func__); return -ENOMEM; } return 0; } module_init(gether_init); static void __exit gether_exit(void) { destroy_workqueue(uether_wq); } module_exit(gether_exit); MODULE_DESCRIPTION("ethernet over USB driver"); MODULE_LICENSE("GPL v2");