/* * Generic HDLC support routines for Linux * Cisco HDLC support * * Copyright (C) 2000 - 2006 Krzysztof Halasa <khc@pm.waw.pl> * * This program is free software; you can redistribute it and/or modify it * under the terms of version 2 of the GNU General Public License * as published by the Free Software Foundation. */ #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> #include <linux/slab.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; }__attribute__ ((packed)); struct cisco_packet { __be32 type; /* code */ __be32 par1; __be32 par2; __be16 rel; /* reliability */ __be32 time; }__attribute__ ((packed)); #define CISCO_PACKET_LEN 18 #define CISCO_BIG_PACKET_LEN 20 struct cisco_state { cisco_proto settings; struct timer_list timer; spinlock_t lock; unsigned long last_poll; int up; int request_sent; u32 txseq; /* TX sequence number */ u32 rxseq; /* RX sequence number */ }; static int cisco_ioctl(struct net_device *dev, struct ifreq *ifr); 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 printk(KERN_DEBUG "%s: cisco_hard_header called\n", dev->name); #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) { printk(KERN_WARNING "%s: Memory squeeze on cisco_keepalive_send()\n", dev->name); 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_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; 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)) { printk(KERN_INFO "%s: Invalid length of Cisco control" " packet (%d bytes)\n", dev->name, 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 :-) */ in_dev = dev->ip_ptr; addr = 0; mask = ~cpu_to_be32(0); /* is the mask correct? */ if (in_dev != NULL) { struct in_ifaddr **ifap = &in_dev->ifa_list; while (*ifap != NULL) { if (strcmp(dev->name, (*ifap)->ifa_label) == 0) { addr = (*ifap)->ifa_local; mask = (*ifap)->ifa_mask; break; } ifap = &(*ifap)->ifa_next; } cisco_keepalive_send(dev, CISCO_ADDR_REPLY, addr, mask); } dev_kfree_skb_any(skb); return NET_RX_SUCCESS; case CISCO_ADDR_REPLY: printk(KERN_INFO "%s: Unexpected Cisco IP address " "reply\n", dev->name); goto rx_error; case CISCO_KEEPALIVE_REQ: spin_lock(&st->lock); st->rxseq = ntohl(cisco_data->par1); if (st->request_sent && ntohl(cisco_data->par2) == st->txseq) { 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; printk(KERN_INFO "%s: Link up (peer " "uptime %ud%uh%um%us)\n", dev->name, 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) */ printk(KERN_INFO "%s: Unsupported protocol %x\n", dev->name, 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(unsigned long arg) { struct net_device *dev = (struct net_device *)arg; hdlc_device *hdlc = dev_to_hdlc(dev); struct cisco_state *st = state(hdlc); spin_lock(&st->lock); if (st->up && time_after(jiffies, st->last_poll + st->settings.timeout * HZ)) { st->up = 0; printk(KERN_INFO "%s: Link down\n", dev->name); netif_dormant_on(dev); } cisco_keepalive_send(dev, CISCO_KEEPALIVE_REQ, htonl(++st->txseq), htonl(st->rxseq)); st->request_sent = 1; spin_unlock(&st->lock); st->timer.expires = jiffies + st->settings.interval * HZ; st->timer.function = cisco_timer; st->timer.data = arg; 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 = 0; st->request_sent = 0; st->txseq = st->rxseq = 0; spin_unlock_irqrestore(&st->lock, flags); init_timer(&st->timer); st->timer.expires = jiffies + HZ; /* First poll after 1 s */ st->timer.function = cisco_timer; st->timer.data = (unsigned long)dev; 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 = 0; st->request_sent = 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 ifreq *ifr) { cisco_proto __user *cisco_s = ifr->ifr_settings.ifs_ifsu.cisco; const size_t size = sizeof(cisco_proto); cisco_proto new_settings; hdlc_device *hdlc = dev_to_hdlc(dev); int result; switch (ifr->ifr_settings.type) { case IF_GET_PROTO: if (dev_to_hdlc(dev)->proto != &proto) return -EINVAL; ifr->ifr_settings.type = IF_PROTO_CISCO; if (ifr->ifr_settings.size < size) { ifr->ifr_settings.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->type = ARPHRD_CISCO; netif_dormant_on(dev); return 0; } return -EINVAL; } static int __init mod_init(void) { register_hdlc_protocol(&proto); return 0; } static void __exit mod_exit(void) { unregister_hdlc_protocol(&proto); } module_init(mod_init); module_exit(mod_exit); MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>"); MODULE_DESCRIPTION("Cisco HDLC protocol support for generic HDLC"); MODULE_LICENSE("GPL v2");