Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * X.25 Packet Layer release 002 |
| 3 | * |
YOSHIFUJI Hideaki | f8e1d201 | 2007-02-09 23:25:27 +0900 | [diff] [blame] | 4 | * This is ALPHA test software. This code may break your machine, randomly fail to work with new |
| 5 | * releases, misbehave and/or generally screw up. It might even work. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 6 | * |
| 7 | * This code REQUIRES 2.1.15 or higher |
| 8 | * |
| 9 | * This module: |
| 10 | * This module is free software; you can redistribute it and/or |
| 11 | * modify it under the terms of the GNU General Public License |
| 12 | * as published by the Free Software Foundation; either version |
| 13 | * 2 of the License, or (at your option) any later version. |
| 14 | * |
| 15 | * History |
| 16 | * X.25 001 Jonathan Naylor Started coding. |
| 17 | * 2000-09-04 Henner Eisen Prevent freeing a dangling skb. |
| 18 | */ |
| 19 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 20 | #include <linux/kernel.h> |
| 21 | #include <linux/netdevice.h> |
| 22 | #include <linux/skbuff.h> |
| 23 | #include <net/sock.h> |
| 24 | #include <linux/if_arp.h> |
| 25 | #include <net/x25.h> |
| 26 | |
| 27 | static int x25_receive_data(struct sk_buff *skb, struct x25_neigh *nb) |
| 28 | { |
| 29 | struct sock *sk; |
| 30 | unsigned short frametype; |
| 31 | unsigned int lci; |
| 32 | |
| 33 | frametype = skb->data[2]; |
YOSHIFUJI Hideaki | f8e1d201 | 2007-02-09 23:25:27 +0900 | [diff] [blame] | 34 | lci = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | |
| 36 | /* |
| 37 | * LCI of zero is always for us, and its always a link control |
| 38 | * frame. |
| 39 | */ |
| 40 | if (lci == 0) { |
| 41 | x25_link_control(skb, nb, frametype); |
| 42 | return 0; |
| 43 | } |
| 44 | |
| 45 | /* |
| 46 | * Find an existing socket. |
| 47 | */ |
| 48 | if ((sk = x25_find_socket(lci, nb)) != NULL) { |
| 49 | int queued = 1; |
| 50 | |
Arnaldo Carvalho de Melo | badff6d | 2007-03-13 13:06:52 -0300 | [diff] [blame] | 51 | skb_reset_transport_header(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | bh_lock_sock(sk); |
| 53 | if (!sock_owned_by_user(sk)) { |
| 54 | queued = x25_process_rx_frame(sk, skb); |
| 55 | } else { |
| 56 | sk_add_backlog(sk, skb); |
| 57 | } |
| 58 | bh_unlock_sock(sk); |
Andrew Hendry | 9d0f7d2 | 2007-01-15 19:29:31 -0800 | [diff] [blame] | 59 | sock_put(sk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | return queued; |
| 61 | } |
| 62 | |
| 63 | /* |
| 64 | * Is is a Call Request ? if so process it. |
| 65 | */ |
| 66 | if (frametype == X25_CALL_REQUEST) |
| 67 | return x25_rx_call_request(skb, nb, lci); |
| 68 | |
| 69 | /* |
Andrew Hendry | 95a9dc4 | 2007-02-08 13:34:02 -0800 | [diff] [blame] | 70 | * Its not a Call Request, nor is it a control frame. |
| 71 | * Can we forward it? |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 72 | */ |
Andrew Hendry | 95a9dc4 | 2007-02-08 13:34:02 -0800 | [diff] [blame] | 73 | |
| 74 | if (x25_forward_data(lci, nb, skb)) { |
| 75 | if (frametype == X25_CLEAR_CONFIRMATION) { |
| 76 | x25_clear_forward_by_lci(lci); |
| 77 | } |
| 78 | kfree_skb(skb); |
| 79 | return 1; |
| 80 | } |
| 81 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | /* |
| 83 | x25_transmit_clear_request(nb, lci, 0x0D); |
| 84 | */ |
| 85 | |
| 86 | if (frametype != X25_CLEAR_CONFIRMATION) |
| 87 | printk(KERN_DEBUG "x25_receive_data(): unknown frame type %2x\n",frametype); |
| 88 | |
| 89 | return 0; |
| 90 | } |
| 91 | |
| 92 | int x25_lapb_receive_frame(struct sk_buff *skb, struct net_device *dev, |
David S. Miller | f2ccd8f | 2005-08-09 19:34:12 -0700 | [diff] [blame] | 93 | struct packet_type *ptype, struct net_device *orig_dev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 94 | { |
| 95 | struct sk_buff *nskb; |
| 96 | struct x25_neigh *nb; |
| 97 | |
| 98 | nskb = skb_copy(skb, GFP_ATOMIC); |
| 99 | if (!nskb) |
| 100 | goto drop; |
| 101 | kfree_skb(skb); |
| 102 | skb = nskb; |
| 103 | |
| 104 | /* |
| 105 | * Packet received from unrecognised device, throw it away. |
| 106 | */ |
| 107 | nb = x25_get_neigh(dev); |
| 108 | if (!nb) { |
| 109 | printk(KERN_DEBUG "X.25: unknown neighbour - %s\n", dev->name); |
| 110 | goto drop; |
| 111 | } |
| 112 | |
| 113 | switch (skb->data[0]) { |
| 114 | case 0x00: |
| 115 | skb_pull(skb, 1); |
| 116 | if (x25_receive_data(skb, nb)) { |
| 117 | x25_neigh_put(nb); |
| 118 | goto out; |
| 119 | } |
| 120 | break; |
| 121 | case 0x01: |
| 122 | x25_link_established(nb); |
| 123 | break; |
| 124 | case 0x02: |
| 125 | x25_link_terminated(nb); |
| 126 | break; |
| 127 | } |
| 128 | x25_neigh_put(nb); |
| 129 | drop: |
| 130 | kfree_skb(skb); |
| 131 | out: |
| 132 | return 0; |
| 133 | } |
| 134 | |
| 135 | void x25_establish_link(struct x25_neigh *nb) |
| 136 | { |
| 137 | struct sk_buff *skb; |
| 138 | unsigned char *ptr; |
| 139 | |
| 140 | switch (nb->dev->type) { |
| 141 | case ARPHRD_X25: |
| 142 | if ((skb = alloc_skb(1, GFP_ATOMIC)) == NULL) { |
| 143 | printk(KERN_ERR "x25_dev: out of memory\n"); |
| 144 | return; |
| 145 | } |
| 146 | ptr = skb_put(skb, 1); |
| 147 | *ptr = 0x01; |
| 148 | break; |
| 149 | |
| 150 | #if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE) |
| 151 | case ARPHRD_ETHER: |
| 152 | return; |
| 153 | #endif |
| 154 | default: |
| 155 | return; |
| 156 | } |
| 157 | |
| 158 | skb->protocol = htons(ETH_P_X25); |
| 159 | skb->dev = nb->dev; |
| 160 | |
| 161 | dev_queue_xmit(skb); |
| 162 | } |
| 163 | |
| 164 | void x25_terminate_link(struct x25_neigh *nb) |
| 165 | { |
| 166 | struct sk_buff *skb; |
| 167 | unsigned char *ptr; |
| 168 | |
| 169 | #if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE) |
| 170 | if (nb->dev->type == ARPHRD_ETHER) |
| 171 | return; |
| 172 | #endif |
| 173 | if (nb->dev->type != ARPHRD_X25) |
| 174 | return; |
| 175 | |
| 176 | skb = alloc_skb(1, GFP_ATOMIC); |
| 177 | if (!skb) { |
| 178 | printk(KERN_ERR "x25_dev: out of memory\n"); |
| 179 | return; |
| 180 | } |
| 181 | |
| 182 | ptr = skb_put(skb, 1); |
| 183 | *ptr = 0x02; |
| 184 | |
| 185 | skb->protocol = htons(ETH_P_X25); |
| 186 | skb->dev = nb->dev; |
| 187 | dev_queue_xmit(skb); |
| 188 | } |
| 189 | |
| 190 | void x25_send_frame(struct sk_buff *skb, struct x25_neigh *nb) |
| 191 | { |
| 192 | unsigned char *dptr; |
| 193 | |
Arnaldo Carvalho de Melo | c1d2bbe | 2007-04-10 20:45:18 -0700 | [diff] [blame] | 194 | skb_reset_network_header(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 195 | |
| 196 | switch (nb->dev->type) { |
| 197 | case ARPHRD_X25: |
| 198 | dptr = skb_push(skb, 1); |
| 199 | *dptr = 0x00; |
| 200 | break; |
| 201 | |
| 202 | #if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE) |
| 203 | case ARPHRD_ETHER: |
| 204 | kfree_skb(skb); |
| 205 | return; |
| 206 | #endif |
| 207 | default: |
| 208 | kfree_skb(skb); |
| 209 | return; |
| 210 | } |
| 211 | |
| 212 | skb->protocol = htons(ETH_P_X25); |
| 213 | skb->dev = nb->dev; |
| 214 | |
| 215 | dev_queue_xmit(skb); |
| 216 | } |