Something went wrong. Try again.
(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
Something went wrong. Try again.
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538// SPDX-License-Identifier: GPL-2.0-or-later/* * "LAPB via ethernet" driver release 001 * * This code REQUIRES 2.1.15 or higher/ NET3.038 * * This is a "pseudo" network driver to allow LAPB over Ethernet. * * This driver can use any ethernet destination address, and can be * limited to accept frames from one dedicated ethernet card only. * * History * LAPBETH 001 Jonathan Naylor Cloned from bpqether.c * 2000-10-29 Henner Eisen lapb_data_indication() return status. * 2000-11-14 Henner Eisen dev_hold/put, NETDEV_GOING_DOWN support */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/errno.h>#include <linux/types.h>#include <linux/socket.h>#include <linux/in.h>#include <linux/slab.h>#include <linux/kernel.h>#include <linux/string.h>#include <linux/net.h>#include <linux/inet.h>#include <linux/netdevice.h>#include <linux/if_arp.h>#include <linux/skbuff.h>#include <net/sock.h>#include <linux/uaccess.h>#include <linux/mm.h>#include <linux/interrupt.h>#include <linux/notifier.h>#include <linux/stat.h>#include <linux/module.h>#include <linux/lapb.h>#include <linux/init.h>
#include <net/netdev_lock.h>#include <net/x25device.h>
static const u8 bcast_addr[6] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
/* If this number is made larger, check that the temporary string buffer * in lapbeth_new_device is large enough to store the probe device name. */#define MAXLAPBDEV 100
struct lapbethdev { struct list_head node; struct net_device *ethdev; /* link to ethernet device */ struct net_device *axdev; /* lapbeth device (lapb#) */ bool up; spinlock_t up_lock; /* Protects "up" */ struct sk_buff_head rx_queue; struct napi_struct napi;};
static LIST_HEAD(lapbeth_devices);
static void lapbeth_connected(struct net_device *dev, int reason);static void lapbeth_disconnected(struct net_device *dev, int reason);
/* ------------------------------------------------------------------------ */
/* Get the LAPB device for the ethernet device */static struct lapbethdev *lapbeth_get_x25_dev(struct net_device *dev){ struct lapbethdev *lapbeth;
list_for_each_entry_rcu(lapbeth, &lapbeth_devices, node, lockdep_rtnl_is_held()) { if (lapbeth->ethdev == dev) return lapbeth; } return NULL;}
static __inline__ int dev_is_ethdev(struct net_device *dev){ return dev->type == ARPHRD_ETHER && !netdev_need_ops_lock(dev);}
/* ------------------------------------------------------------------------ */
static int lapbeth_napi_poll(struct napi_struct *napi, int budget){ struct lapbethdev *lapbeth = container_of(napi, struct lapbethdev, napi); struct sk_buff *skb; int processed = 0;
for (; processed < budget; ++processed) { skb = skb_dequeue(&lapbeth->rx_queue); if (!skb) break; netif_receive_skb_core(skb); }
if (processed < budget) napi_complete(napi);
return processed;}
/* Receive a LAPB frame via an ethernet interface. */static int lapbeth_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *ptype, struct net_device *orig_dev){ int len, err; struct lapbethdev *lapbeth;
if (dev_net(dev) != &init_net) goto drop;
skb = skb_share_check(skb, GFP_ATOMIC); if (!skb) return NET_RX_DROP;
if (!pskb_may_pull(skb, 2)) goto drop;
rcu_read_lock(); lapbeth = lapbeth_get_x25_dev(dev); if (!lapbeth) goto drop_unlock_rcu; spin_lock_bh(&lapbeth->up_lock); if (!lapbeth->up) goto drop_unlock;
len = skb->data[0] + skb->data[1] * 256; dev->stats.rx_packets++; dev->stats.rx_bytes += len;
skb_pull(skb, 2); /* Remove the length bytes */ skb_trim(skb, len); /* Set the length of the data */
err = lapb_data_received(lapbeth->axdev, skb); if (err != LAPB_OK) { printk(KERN_DEBUG "lapbether: lapb_data_received err - %d\n", err); goto drop_unlock; }out: spin_unlock_bh(&lapbeth->up_lock); rcu_read_unlock(); return 0;drop_unlock: kfree_skb(skb); goto out;drop_unlock_rcu: rcu_read_unlock();drop: kfree_skb(skb); return 0;}
static int lapbeth_data_indication(struct net_device *dev, struct sk_buff *skb){ struct lapbethdev *lapbeth = netdev_priv(dev); unsigned char *ptr;
if (skb_cow(skb, 1)) { kfree_skb(skb); return NET_RX_DROP; }
skb_push(skb, 1);
ptr = skb->data; *ptr = X25_IFACE_DATA;
skb->protocol = x25_type_trans(skb, dev);
skb_queue_tail(&lapbeth->rx_queue, skb); napi_schedule(&lapbeth->napi); return NET_RX_SUCCESS;}
/* Send a LAPB frame via an ethernet interface */static netdev_tx_t lapbeth_xmit(struct sk_buff *skb, struct net_device *dev){ struct lapbethdev *lapbeth = netdev_priv(dev); int err;
spin_lock_bh(&lapbeth->up_lock); if (!lapbeth->up) goto drop;
/* There should be a pseudo header of 1 byte added by upper layers. * Check to make sure it is there before reading it. */ if (skb->len < 1) goto drop;
switch (skb->data[0]) { case X25_IFACE_DATA: break; case X25_IFACE_CONNECT: err = lapb_connect_request(dev); if (err == LAPB_CONNECTED) lapbeth_connected(dev, LAPB_OK); else if (err != LAPB_OK) pr_err("lapb_connect_request error: %d\n", err); goto drop; case X25_IFACE_DISCONNECT: err = lapb_disconnect_request(dev); if (err == LAPB_NOTCONNECTED) lapbeth_disconnected(dev, LAPB_OK); else if (err != LAPB_OK) pr_err("lapb_disconnect_request err: %d\n", err); fallthrough; default: goto drop; }
skb_pull(skb, 1);
err = lapb_data_request(dev, skb); if (err != LAPB_OK) { pr_err("lapb_data_request error - %d\n", err); goto drop; }out: spin_unlock_bh(&lapbeth->up_lock); return NETDEV_TX_OK;drop: kfree_skb(skb); goto out;}
static void lapbeth_data_transmit(struct net_device *ndev, struct sk_buff *skb){ struct lapbethdev *lapbeth = netdev_priv(ndev); unsigned char *ptr; struct net_device *dev; int size = skb->len;
ptr = skb_push(skb, 2);
*ptr++ = size % 256; *ptr++ = size / 256;
ndev->stats.tx_packets++; ndev->stats.tx_bytes += size;
skb->dev = dev = lapbeth->ethdev;
skb->protocol = htons(ETH_P_DEC);
skb_reset_network_header(skb);
dev_hard_header(skb, dev, ETH_P_DEC, bcast_addr, NULL, 0);
dev_queue_xmit(skb);}
static void lapbeth_connected(struct net_device *dev, int reason){ struct lapbethdev *lapbeth = netdev_priv(dev); unsigned char *ptr; struct sk_buff *skb = __dev_alloc_skb(1, GFP_ATOMIC | __GFP_NOMEMALLOC);
if (!skb) return;
ptr = skb_put(skb, 1); *ptr = X25_IFACE_CONNECT;
skb->protocol = x25_type_trans(skb, dev);
skb_queue_tail(&lapbeth->rx_queue, skb); napi_schedule(&lapbeth->napi);}
static void lapbeth_disconnected(struct net_device *dev, int reason){ struct lapbethdev *lapbeth = netdev_priv(dev); unsigned char *ptr; struct sk_buff *skb = __dev_alloc_skb(1, GFP_ATOMIC | __GFP_NOMEMALLOC);
if (!skb) return;
ptr = skb_put(skb, 1); *ptr = X25_IFACE_DISCONNECT;
skb->protocol = x25_type_trans(skb, dev);
skb_queue_tail(&lapbeth->rx_queue, skb); napi_schedule(&lapbeth->napi);}
/* Set AX.25 callsign */static int lapbeth_set_mac_address(struct net_device *dev, void *addr){ struct sockaddr *sa = addr;
dev_addr_set(dev, sa->sa_data); return 0;}
static const struct lapb_register_struct lapbeth_callbacks = { .connect_confirmation = lapbeth_connected, .connect_indication = lapbeth_connected, .disconnect_confirmation = lapbeth_disconnected, .disconnect_indication = lapbeth_disconnected, .data_indication = lapbeth_data_indication, .data_transmit = lapbeth_data_transmit,};
/* open/close a device */static int lapbeth_open(struct net_device *dev){ struct lapbethdev *lapbeth = netdev_priv(dev); int err;
napi_enable(&lapbeth->napi);
err = lapb_register(dev, &lapbeth_callbacks); if (err != LAPB_OK) { napi_disable(&lapbeth->napi); pr_err("lapb_register error: %d\n", err); return -ENODEV; }
spin_lock_bh(&lapbeth->up_lock); lapbeth->up = true; spin_unlock_bh(&lapbeth->up_lock);
return 0;}
static int lapbeth_close(struct net_device *dev){ struct lapbethdev *lapbeth = netdev_priv(dev); int err;
spin_lock_bh(&lapbeth->up_lock); lapbeth->up = false; spin_unlock_bh(&lapbeth->up_lock);
err = lapb_unregister(dev); if (err != LAPB_OK) pr_err("lapb_unregister error: %d\n", err);
napi_disable(&lapbeth->napi);
return 0;}
/* ------------------------------------------------------------------------ */
static const struct net_device_ops lapbeth_netdev_ops = { .ndo_open = lapbeth_open, .ndo_stop = lapbeth_close, .ndo_start_xmit = lapbeth_xmit, .ndo_set_mac_address = lapbeth_set_mac_address,};
static void lapbeth_setup(struct net_device *dev){ netdev_lockdep_set_classes(dev); dev->netdev_ops = &lapbeth_netdev_ops; dev->needs_free_netdev = true; dev->type = ARPHRD_X25; dev->hard_header_len = 0; dev->mtu = 1000; dev->addr_len = 0;}
/* Setup a new device. */static int lapbeth_new_device(struct net_device *dev){ struct net_device *ndev; struct lapbethdev *lapbeth; int rc = -ENOMEM;
ASSERT_RTNL();
if (dev->type != ARPHRD_ETHER) return -EINVAL;
ndev = alloc_netdev(sizeof(*lapbeth), "lapb%d", NET_NAME_UNKNOWN, lapbeth_setup); if (!ndev) goto out;
/* When transmitting data: * first this driver removes a pseudo header of 1 byte, * then the lapb module prepends an LAPB header of at most 3 bytes, * then this driver prepends a length field of 2 bytes, * then the underlying Ethernet device prepends its own header. */ ndev->needed_headroom = -1 + 3 + 2 + dev->hard_header_len + dev->needed_headroom; ndev->needed_tailroom = dev->needed_tailroom;
lapbeth = netdev_priv(ndev); lapbeth->axdev = ndev;
dev_hold(dev); lapbeth->ethdev = dev;
lapbeth->up = false; spin_lock_init(&lapbeth->up_lock);
skb_queue_head_init(&lapbeth->rx_queue); netif_napi_add_weight(ndev, &lapbeth->napi, lapbeth_napi_poll, 16);
rc = -EIO; if (register_netdevice(ndev)) goto fail;
list_add_rcu(&lapbeth->node, &lapbeth_devices); rc = 0;out: return rc;fail: dev_put(dev); free_netdev(ndev); goto out;}
/* Free a lapb network device. */static void lapbeth_free_device(struct lapbethdev *lapbeth){ dev_put(lapbeth->ethdev); list_del_rcu(&lapbeth->node); unregister_netdevice(lapbeth->axdev);}
/* Handle device status changes. * * Called from notifier with RTNL held. */static int lapbeth_device_event(struct notifier_block *this, unsigned long event, void *ptr){ struct net_device *dev = netdev_notifier_info_to_dev(ptr); struct lapbethdev *lapbeth;
if (dev_net(dev) != &init_net) return NOTIFY_DONE;
lapbeth = lapbeth_get_x25_dev(dev); if (!dev_is_ethdev(dev) && !lapbeth) return NOTIFY_DONE;
switch (event) { case NETDEV_UP: /* New ethernet device -> new LAPB interface */ if (!lapbeth) lapbeth_new_device(dev); break; case NETDEV_GOING_DOWN: /* ethernet device closes -> close LAPB interface */ if (lapbeth) dev_close(lapbeth->axdev); break; case NETDEV_UNREGISTER: /* ethernet device disappears -> remove LAPB interface */ if (lapbeth) lapbeth_free_device(lapbeth); break; case NETDEV_PRE_TYPE_CHANGE: /* Our underlying device type must not change. */ if (lapbeth) return NOTIFY_BAD; }
return NOTIFY_DONE;}
/* ------------------------------------------------------------------------ */
static struct packet_type lapbeth_packet_type __read_mostly = { .type = cpu_to_be16(ETH_P_DEC), .func = lapbeth_rcv,};
static struct notifier_block lapbeth_dev_notifier = { .notifier_call = lapbeth_device_event,};
static const char banner[] __initconst = KERN_INFO "LAPB Ethernet driver version 0.02\n";
static int __init lapbeth_init_driver(void){ int err;
dev_add_pack(&lapbeth_packet_type);
err = register_netdevice_notifier(&lapbeth_dev_notifier); if (err) { dev_remove_pack(&lapbeth_packet_type); return err; }
printk(banner);
return 0;}module_init(lapbeth_init_driver);
static void __exit lapbeth_cleanup_driver(void){ struct lapbethdev *lapbeth; struct list_head *entry, *tmp;
dev_remove_pack(&lapbeth_packet_type); unregister_netdevice_notifier(&lapbeth_dev_notifier);
rtnl_lock(); list_for_each_safe(entry, tmp, &lapbeth_devices) { lapbeth = list_entry(entry, struct lapbethdev, node);
dev_put(lapbeth->ethdev); unregister_netdevice(lapbeth->axdev); } rtnl_unlock();}module_exit(lapbeth_cleanup_driver);
MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>");MODULE_DESCRIPTION("The unofficial LAPB over Ethernet driver");MODULE_LICENSE("GPL");