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