From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- drivers/net/wan/hdlc.c | 379 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 379 insertions(+) create mode 100644 drivers/net/wan/hdlc.c (limited to 'drivers/net/wan/hdlc.c') diff --git a/drivers/net/wan/hdlc.c b/drivers/net/wan/hdlc.c new file mode 100644 index 000000000..cbed10b1d --- /dev/null +++ b/drivers/net/wan/hdlc.c @@ -0,0 +1,379 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Generic HDLC support routines for Linux + * + * Copyright (C) 1999 - 2008 Krzysztof Halasa + * + * Currently supported: + * * raw IP-in-HDLC + * * Cisco HDLC + * * Frame Relay with ANSI or CCITT LMI (both user and network side) + * * PPP + * * X.25 + * + * Use sethdlc utility to set line parameters, protocol and PVCs + * + * How does it work: + * - proto->open(), close(), start(), stop() calls are serialized. + * The order is: open, [ start, stop ... ] close ... + * - proto->start() and stop() are called with spin_lock_irq held. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static const char *version = "HDLC support module revision 1.22"; + +#undef DEBUG_LINK + +static struct hdlc_proto *first_proto; + +static int hdlc_rcv(struct sk_buff *skb, struct net_device *dev, + struct packet_type *p, struct net_device *orig_dev) +{ + struct hdlc_device *hdlc; + + /* First make sure "dev" is an HDLC device */ + if (!(dev->priv_flags & IFF_WAN_HDLC)) { + kfree_skb(skb); + return NET_RX_SUCCESS; + } + + hdlc = dev_to_hdlc(dev); + + if (!net_eq(dev_net(dev), &init_net)) { + kfree_skb(skb); + return 0; + } + + BUG_ON(!hdlc->proto->netif_rx); + return hdlc->proto->netif_rx(skb); +} + +netdev_tx_t hdlc_start_xmit(struct sk_buff *skb, struct net_device *dev) +{ + hdlc_device *hdlc = dev_to_hdlc(dev); + + if (hdlc->proto->xmit) + return hdlc->proto->xmit(skb, dev); + + return hdlc->xmit(skb, dev); /* call hardware driver directly */ +} +EXPORT_SYMBOL(hdlc_start_xmit); + +static inline void hdlc_proto_start(struct net_device *dev) +{ + hdlc_device *hdlc = dev_to_hdlc(dev); + + if (hdlc->proto->start) + hdlc->proto->start(dev); +} + +static inline void hdlc_proto_stop(struct net_device *dev) +{ + hdlc_device *hdlc = dev_to_hdlc(dev); + + if (hdlc->proto->stop) + hdlc->proto->stop(dev); +} + +static int hdlc_device_event(struct notifier_block *this, unsigned long event, + void *ptr) +{ + struct net_device *dev = netdev_notifier_info_to_dev(ptr); + hdlc_device *hdlc; + unsigned long flags; + int on; + + if (!net_eq(dev_net(dev), &init_net)) + return NOTIFY_DONE; + + if (!(dev->priv_flags & IFF_WAN_HDLC)) + return NOTIFY_DONE; /* not an HDLC device */ + + if (event != NETDEV_CHANGE) + return NOTIFY_DONE; /* Only interested in carrier changes */ + + on = netif_carrier_ok(dev); + +#ifdef DEBUG_LINK + printk(KERN_DEBUG "%s: hdlc_device_event NETDEV_CHANGE, carrier %i\n", + dev->name, on); +#endif + + hdlc = dev_to_hdlc(dev); + spin_lock_irqsave(&hdlc->state_lock, flags); + + if (hdlc->carrier == on) + goto carrier_exit; /* no change in DCD line level */ + + hdlc->carrier = on; + + if (!hdlc->open) + goto carrier_exit; + + if (hdlc->carrier) { + netdev_info(dev, "Carrier detected\n"); + hdlc_proto_start(dev); + } else { + netdev_info(dev, "Carrier lost\n"); + hdlc_proto_stop(dev); + } + +carrier_exit: + spin_unlock_irqrestore(&hdlc->state_lock, flags); + return NOTIFY_DONE; +} + +/* Must be called by hardware driver when HDLC device is being opened */ +int hdlc_open(struct net_device *dev) +{ + hdlc_device *hdlc = dev_to_hdlc(dev); +#ifdef DEBUG_LINK + printk(KERN_DEBUG "%s: hdlc_open() carrier %i open %i\n", dev->name, + hdlc->carrier, hdlc->open); +#endif + + if (!hdlc->proto) + return -ENOSYS; /* no protocol attached */ + + if (hdlc->proto->open) { + int result = hdlc->proto->open(dev); + + if (result) + return result; + } + + spin_lock_irq(&hdlc->state_lock); + + if (hdlc->carrier) { + netdev_info(dev, "Carrier detected\n"); + hdlc_proto_start(dev); + } else { + netdev_info(dev, "No carrier\n"); + } + + hdlc->open = 1; + + spin_unlock_irq(&hdlc->state_lock); + return 0; +} +EXPORT_SYMBOL(hdlc_open); + +/* Must be called by hardware driver when HDLC device is being closed */ +void hdlc_close(struct net_device *dev) +{ + hdlc_device *hdlc = dev_to_hdlc(dev); +#ifdef DEBUG_LINK + printk(KERN_DEBUG "%s: hdlc_close() carrier %i open %i\n", dev->name, + hdlc->carrier, hdlc->open); +#endif + + spin_lock_irq(&hdlc->state_lock); + + hdlc->open = 0; + if (hdlc->carrier) + hdlc_proto_stop(dev); + + spin_unlock_irq(&hdlc->state_lock); + + if (hdlc->proto->close) + hdlc->proto->close(dev); +} +EXPORT_SYMBOL(hdlc_close); + +int hdlc_ioctl(struct net_device *dev, struct if_settings *ifs) +{ + struct hdlc_proto *proto = first_proto; + int result; + + if (dev_to_hdlc(dev)->proto) { + result = dev_to_hdlc(dev)->proto->ioctl(dev, ifs); + if (result != -EINVAL) + return result; + } + + /* Not handled by currently attached protocol (if any) */ + + while (proto) { + result = proto->ioctl(dev, ifs); + if (result != -EINVAL) + return result; + proto = proto->next; + } + return -EINVAL; +} +EXPORT_SYMBOL(hdlc_ioctl); + +static const struct header_ops hdlc_null_ops; + +static void hdlc_setup_dev(struct net_device *dev) +{ + /* Re-init all variables changed by HDLC protocol drivers, + * including ether_setup() called from hdlc_raw_eth.c. + */ + dev->flags = IFF_POINTOPOINT | IFF_NOARP; + dev->priv_flags = IFF_WAN_HDLC; + dev->mtu = HDLC_MAX_MTU; + dev->min_mtu = 68; + dev->max_mtu = HDLC_MAX_MTU; + dev->type = ARPHRD_RAWHDLC; + dev->hard_header_len = 0; + dev->needed_headroom = 0; + dev->addr_len = 0; + dev->header_ops = &hdlc_null_ops; +} + +static void hdlc_setup(struct net_device *dev) +{ + hdlc_device *hdlc = dev_to_hdlc(dev); + + hdlc_setup_dev(dev); + hdlc->carrier = 1; + hdlc->open = 0; + spin_lock_init(&hdlc->state_lock); +} + +struct net_device *alloc_hdlcdev(void *priv) +{ + struct net_device *dev; + + dev = alloc_netdev(sizeof(struct hdlc_device), "hdlc%d", + NET_NAME_UNKNOWN, hdlc_setup); + if (dev) + dev_to_hdlc(dev)->priv = priv; + return dev; +} +EXPORT_SYMBOL(alloc_hdlcdev); + +void unregister_hdlc_device(struct net_device *dev) +{ + rtnl_lock(); + detach_hdlc_protocol(dev); + unregister_netdevice(dev); + rtnl_unlock(); +} +EXPORT_SYMBOL(unregister_hdlc_device); + +int attach_hdlc_protocol(struct net_device *dev, struct hdlc_proto *proto, + size_t size) +{ + int err; + + err = detach_hdlc_protocol(dev); + if (err) + return err; + + if (!try_module_get(proto->module)) + return -ENOSYS; + + if (size) { + dev_to_hdlc(dev)->state = kmalloc(size, GFP_KERNEL); + if (!dev_to_hdlc(dev)->state) { + module_put(proto->module); + return -ENOBUFS; + } + } + dev_to_hdlc(dev)->proto = proto; + + return 0; +} +EXPORT_SYMBOL(attach_hdlc_protocol); + +int detach_hdlc_protocol(struct net_device *dev) +{ + hdlc_device *hdlc = dev_to_hdlc(dev); + int err; + + if (hdlc->proto) { + err = call_netdevice_notifiers(NETDEV_PRE_TYPE_CHANGE, dev); + err = notifier_to_errno(err); + if (err) { + netdev_err(dev, "Refused to change device type\n"); + return err; + } + + if (hdlc->proto->detach) + hdlc->proto->detach(dev); + module_put(hdlc->proto->module); + hdlc->proto = NULL; + } + kfree(hdlc->state); + hdlc->state = NULL; + hdlc_setup_dev(dev); + + return 0; +} +EXPORT_SYMBOL(detach_hdlc_protocol); + +void register_hdlc_protocol(struct hdlc_proto *proto) +{ + rtnl_lock(); + proto->next = first_proto; + first_proto = proto; + rtnl_unlock(); +} +EXPORT_SYMBOL(register_hdlc_protocol); + +void unregister_hdlc_protocol(struct hdlc_proto *proto) +{ + struct hdlc_proto **p; + + rtnl_lock(); + p = &first_proto; + while (*p != proto) { + BUG_ON(!*p); + p = &((*p)->next); + } + *p = proto->next; + rtnl_unlock(); +} +EXPORT_SYMBOL(unregister_hdlc_protocol); + +MODULE_AUTHOR("Krzysztof Halasa "); +MODULE_DESCRIPTION("HDLC support module"); +MODULE_LICENSE("GPL v2"); + +static struct packet_type hdlc_packet_type __read_mostly = { + .type = cpu_to_be16(ETH_P_HDLC), + .func = hdlc_rcv, +}; + +static struct notifier_block hdlc_notifier = { + .notifier_call = hdlc_device_event, +}; + +static int __init hdlc_module_init(void) +{ + int result; + + pr_info("%s\n", version); + result = register_netdevice_notifier(&hdlc_notifier); + if (result) + return result; + dev_add_pack(&hdlc_packet_type); + return 0; +} + +static void __exit hdlc_module_exit(void) +{ + dev_remove_pack(&hdlc_packet_type); + unregister_netdevice_notifier(&hdlc_notifier); +} + +module_init(hdlc_module_init); +module_exit(hdlc_module_exit); -- cgit v1.2.3