diff options
Diffstat (limited to 'drivers/net/wan/hdlc_cisco.c')
| -rw-r--r-- | drivers/net/wan/hdlc_cisco.c | 383 |
1 files changed, 383 insertions, 0 deletions
diff --git a/drivers/net/wan/hdlc_cisco.c b/drivers/net/wan/hdlc_cisco.c new file mode 100644 index 000000000..cdebe65a7 --- /dev/null +++ b/drivers/net/wan/hdlc_cisco.c @@ -0,0 +1,383 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Generic HDLC support routines for Linux + * Cisco HDLC support + * + * Copyright (C) 2000 - 2006 Krzysztof Halasa <khc@pm.waw.pl> + */ + +#include <linux/errno.h> +#include <linux/hdlc.h> +#include <linux/if_arp.h> +#include <linux/inetdevice.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/pkt_sched.h> +#include <linux/poll.h> +#include <linux/rtnetlink.h> +#include <linux/skbuff.h> + +#undef DEBUG_HARD_HEADER + +#define CISCO_MULTICAST 0x8F /* Cisco multicast address */ +#define CISCO_UNICAST 0x0F /* Cisco unicast address */ +#define CISCO_KEEPALIVE 0x8035 /* Cisco keepalive protocol */ +#define CISCO_SYS_INFO 0x2000 /* Cisco interface/system info */ +#define CISCO_ADDR_REQ 0 /* Cisco address request */ +#define CISCO_ADDR_REPLY 1 /* Cisco address reply */ +#define CISCO_KEEPALIVE_REQ 2 /* Cisco keepalive request */ + +struct hdlc_header { + u8 address; + u8 control; + __be16 protocol; +} __packed; + +struct cisco_packet { + __be32 type; /* code */ + __be32 par1; + __be32 par2; + __be16 rel; /* reliability */ + __be32 time; +} __packed; +#define CISCO_PACKET_LEN 18 +#define CISCO_BIG_PACKET_LEN 20 + +struct cisco_state { + cisco_proto settings; + + struct timer_list timer; + struct net_device *dev; + spinlock_t lock; + unsigned long last_poll; + int up; + u32 txseq; /* TX sequence number, 0 = none */ + u32 rxseq; /* RX sequence number */ +}; + +static int cisco_ioctl(struct net_device *dev, struct if_settings *ifs); + +static inline struct cisco_state *state(hdlc_device *hdlc) +{ + return (struct cisco_state *)hdlc->state; +} + +static int cisco_hard_header(struct sk_buff *skb, struct net_device *dev, + u16 type, const void *daddr, const void *saddr, + unsigned int len) +{ + struct hdlc_header *data; +#ifdef DEBUG_HARD_HEADER + netdev_dbg(dev, "%s called\n", __func__); +#endif + + skb_push(skb, sizeof(struct hdlc_header)); + data = (struct hdlc_header *)skb->data; + if (type == CISCO_KEEPALIVE) + data->address = CISCO_MULTICAST; + else + data->address = CISCO_UNICAST; + data->control = 0; + data->protocol = htons(type); + + return sizeof(struct hdlc_header); +} + +static void cisco_keepalive_send(struct net_device *dev, u32 type, + __be32 par1, __be32 par2) +{ + struct sk_buff *skb; + struct cisco_packet *data; + + skb = dev_alloc_skb(sizeof(struct hdlc_header) + + sizeof(struct cisco_packet)); + if (!skb) + return; + + skb_reserve(skb, 4); + cisco_hard_header(skb, dev, CISCO_KEEPALIVE, NULL, NULL, 0); + data = (struct cisco_packet *)(skb->data + 4); + + data->type = htonl(type); + data->par1 = par1; + data->par2 = par2; + data->rel = cpu_to_be16(0xFFFF); + /* we will need do_div here if 1000 % HZ != 0 */ + data->time = htonl((jiffies - INITIAL_JIFFIES) * (1000 / HZ)); + + skb_put(skb, sizeof(struct cisco_packet)); + skb->priority = TC_PRIO_CONTROL; + skb->dev = dev; + skb->protocol = htons(ETH_P_HDLC); + skb_reset_network_header(skb); + + dev_queue_xmit(skb); +} + +static __be16 cisco_type_trans(struct sk_buff *skb, struct net_device *dev) +{ + struct hdlc_header *data = (struct hdlc_header *)skb->data; + + if (skb->len < sizeof(struct hdlc_header)) + return cpu_to_be16(ETH_P_HDLC); + + if (data->address != CISCO_MULTICAST && + data->address != CISCO_UNICAST) + return cpu_to_be16(ETH_P_HDLC); + + switch (data->protocol) { + case cpu_to_be16(ETH_P_IP): + case cpu_to_be16(ETH_P_IPX): + case cpu_to_be16(ETH_P_IPV6): + skb_pull(skb, sizeof(struct hdlc_header)); + return data->protocol; + default: + return cpu_to_be16(ETH_P_HDLC); + } +} + +static int cisco_rx(struct sk_buff *skb) +{ + struct net_device *dev = skb->dev; + hdlc_device *hdlc = dev_to_hdlc(dev); + struct cisco_state *st = state(hdlc); + struct hdlc_header *data = (struct hdlc_header *)skb->data; + struct cisco_packet *cisco_data; + struct in_device *in_dev; + __be32 addr, mask; + u32 ack; + + if (skb->len < sizeof(struct hdlc_header)) + goto rx_error; + + if (data->address != CISCO_MULTICAST && + data->address != CISCO_UNICAST) + goto rx_error; + + switch (ntohs(data->protocol)) { + case CISCO_SYS_INFO: + /* Packet is not needed, drop it. */ + dev_kfree_skb_any(skb); + return NET_RX_SUCCESS; + + case CISCO_KEEPALIVE: + if ((skb->len != sizeof(struct hdlc_header) + + CISCO_PACKET_LEN) && + (skb->len != sizeof(struct hdlc_header) + + CISCO_BIG_PACKET_LEN)) { + netdev_info(dev, "Invalid length of Cisco control packet (%d bytes)\n", + skb->len); + goto rx_error; + } + + cisco_data = (struct cisco_packet *)(skb->data + sizeof + (struct hdlc_header)); + + switch (ntohl(cisco_data->type)) { + case CISCO_ADDR_REQ: /* Stolen from syncppp.c :-) */ + rcu_read_lock(); + in_dev = __in_dev_get_rcu(dev); + addr = 0; + mask = ~cpu_to_be32(0); /* is the mask correct? */ + + if (in_dev != NULL) { + const struct in_ifaddr *ifa; + + in_dev_for_each_ifa_rcu(ifa, in_dev) { + if (strcmp(dev->name, + ifa->ifa_label) == 0) { + addr = ifa->ifa_local; + mask = ifa->ifa_mask; + break; + } + } + + cisco_keepalive_send(dev, CISCO_ADDR_REPLY, + addr, mask); + } + rcu_read_unlock(); + dev_kfree_skb_any(skb); + return NET_RX_SUCCESS; + + case CISCO_ADDR_REPLY: + netdev_info(dev, "Unexpected Cisco IP address reply\n"); + goto rx_error; + + case CISCO_KEEPALIVE_REQ: + spin_lock(&st->lock); + st->rxseq = ntohl(cisco_data->par1); + ack = ntohl(cisco_data->par2); + if (ack && (ack == st->txseq || + /* our current REQ may be in transit */ + ack == st->txseq - 1)) { + st->last_poll = jiffies; + if (!st->up) { + u32 sec, min, hrs, days; + + sec = ntohl(cisco_data->time) / 1000; + min = sec / 60; sec -= min * 60; + hrs = min / 60; min -= hrs * 60; + days = hrs / 24; hrs -= days * 24; + netdev_info(dev, "Link up (peer uptime %ud%uh%um%us)\n", + days, hrs, min, sec); + netif_dormant_off(dev); + st->up = 1; + } + } + spin_unlock(&st->lock); + + dev_kfree_skb_any(skb); + return NET_RX_SUCCESS; + } /* switch (keepalive type) */ + } /* switch (protocol) */ + + netdev_info(dev, "Unsupported protocol %x\n", ntohs(data->protocol)); + dev_kfree_skb_any(skb); + return NET_RX_DROP; + +rx_error: + dev->stats.rx_errors++; /* Mark error */ + dev_kfree_skb_any(skb); + return NET_RX_DROP; +} + +static void cisco_timer(struct timer_list *t) +{ + struct cisco_state *st = from_timer(st, t, timer); + struct net_device *dev = st->dev; + + spin_lock(&st->lock); + if (st->up && + time_after(jiffies, st->last_poll + st->settings.timeout * HZ)) { + st->up = 0; + netdev_info(dev, "Link down\n"); + netif_dormant_on(dev); + } + + cisco_keepalive_send(dev, CISCO_KEEPALIVE_REQ, htonl(++st->txseq), + htonl(st->rxseq)); + spin_unlock(&st->lock); + + st->timer.expires = jiffies + st->settings.interval * HZ; + add_timer(&st->timer); +} + +static void cisco_start(struct net_device *dev) +{ + hdlc_device *hdlc = dev_to_hdlc(dev); + struct cisco_state *st = state(hdlc); + unsigned long flags; + + spin_lock_irqsave(&st->lock, flags); + st->up = st->txseq = st->rxseq = 0; + spin_unlock_irqrestore(&st->lock, flags); + + st->dev = dev; + timer_setup(&st->timer, cisco_timer, 0); + st->timer.expires = jiffies + HZ; /* First poll after 1 s */ + add_timer(&st->timer); +} + +static void cisco_stop(struct net_device *dev) +{ + hdlc_device *hdlc = dev_to_hdlc(dev); + struct cisco_state *st = state(hdlc); + unsigned long flags; + + del_timer_sync(&st->timer); + + spin_lock_irqsave(&st->lock, flags); + netif_dormant_on(dev); + st->up = st->txseq = 0; + spin_unlock_irqrestore(&st->lock, flags); +} + +static struct hdlc_proto proto = { + .start = cisco_start, + .stop = cisco_stop, + .type_trans = cisco_type_trans, + .ioctl = cisco_ioctl, + .netif_rx = cisco_rx, + .module = THIS_MODULE, +}; + +static const struct header_ops cisco_header_ops = { + .create = cisco_hard_header, +}; + +static int cisco_ioctl(struct net_device *dev, struct if_settings *ifs) +{ + cisco_proto __user *cisco_s = ifs->ifs_ifsu.cisco; + const size_t size = sizeof(cisco_proto); + cisco_proto new_settings; + hdlc_device *hdlc = dev_to_hdlc(dev); + int result; + + switch (ifs->type) { + case IF_GET_PROTO: + if (dev_to_hdlc(dev)->proto != &proto) + return -EINVAL; + ifs->type = IF_PROTO_CISCO; + if (ifs->size < size) { + ifs->size = size; /* data size wanted */ + return -ENOBUFS; + } + if (copy_to_user(cisco_s, &state(hdlc)->settings, size)) + return -EFAULT; + return 0; + + case IF_PROTO_CISCO: + if (!capable(CAP_NET_ADMIN)) + return -EPERM; + + if (dev->flags & IFF_UP) + return -EBUSY; + + if (copy_from_user(&new_settings, cisco_s, size)) + return -EFAULT; + + if (new_settings.interval < 1 || + new_settings.timeout < 2) + return -EINVAL; + + result = hdlc->attach(dev, ENCODING_NRZ, + PARITY_CRC16_PR1_CCITT); + if (result) + return result; + + result = attach_hdlc_protocol(dev, &proto, + sizeof(struct cisco_state)); + if (result) + return result; + + memcpy(&state(hdlc)->settings, &new_settings, size); + spin_lock_init(&state(hdlc)->lock); + dev->header_ops = &cisco_header_ops; + dev->hard_header_len = sizeof(struct hdlc_header); + dev->type = ARPHRD_CISCO; + call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev); + netif_dormant_on(dev); + return 0; + } + + return -EINVAL; +} + +static int __init hdlc_cisco_init(void) +{ + register_hdlc_protocol(&proto); + return 0; +} + +static void __exit hdlc_cisco_exit(void) +{ + unregister_hdlc_protocol(&proto); +} + +module_init(hdlc_cisco_init); +module_exit(hdlc_cisco_exit); + +MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>"); +MODULE_DESCRIPTION("Cisco HDLC protocol support for generic HDLC"); +MODULE_LICENSE("GPL v2"); |