Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * X.25 Packet Layer release 002 | |
3 | * | |
f8e1d201 YH |
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. | |
1da177e4 LT |
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 | ||
b73e9e3c | 20 | #define pr_fmt(fmt) "X25: " fmt |
21 | ||
1da177e4 LT |
22 | #include <linux/kernel.h> |
23 | #include <linux/netdevice.h> | |
24 | #include <linux/skbuff.h> | |
5a0e3ad6 | 25 | #include <linux/slab.h> |
1da177e4 LT |
26 | #include <net/sock.h> |
27 | #include <linux/if_arp.h> | |
28 | #include <net/x25.h> | |
5ebfbc06 | 29 | #include <net/x25device.h> |
1da177e4 LT |
30 | |
31 | static int x25_receive_data(struct sk_buff *skb, struct x25_neigh *nb) | |
32 | { | |
33 | struct sock *sk; | |
34 | unsigned short frametype; | |
35 | unsigned int lci; | |
36 | ||
cb101ed2 MD |
37 | if (!pskb_may_pull(skb, X25_STD_MIN_LEN)) |
38 | return 0; | |
39 | ||
1da177e4 | 40 | frametype = skb->data[2]; |
f8e1d201 | 41 | lci = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF); |
1da177e4 LT |
42 | |
43 | /* | |
44 | * LCI of zero is always for us, and its always a link control | |
45 | * frame. | |
46 | */ | |
47 | if (lci == 0) { | |
48 | x25_link_control(skb, nb, frametype); | |
49 | return 0; | |
50 | } | |
51 | ||
52 | /* | |
53 | * Find an existing socket. | |
54 | */ | |
55 | if ((sk = x25_find_socket(lci, nb)) != NULL) { | |
56 | int queued = 1; | |
57 | ||
badff6d0 | 58 | skb_reset_transport_header(skb); |
1da177e4 LT |
59 | bh_lock_sock(sk); |
60 | if (!sock_owned_by_user(sk)) { | |
61 | queued = x25_process_rx_frame(sk, skb); | |
62 | } else { | |
f545a38f | 63 | queued = !sk_add_backlog(sk, skb, sk->sk_rcvbuf); |
1da177e4 LT |
64 | } |
65 | bh_unlock_sock(sk); | |
9d0f7d29 | 66 | sock_put(sk); |
1da177e4 LT |
67 | return queued; |
68 | } | |
69 | ||
70 | /* | |
71 | * Is is a Call Request ? if so process it. | |
72 | */ | |
73 | if (frametype == X25_CALL_REQUEST) | |
74 | return x25_rx_call_request(skb, nb, lci); | |
75 | ||
76 | /* | |
95a9dc43 AH |
77 | * Its not a Call Request, nor is it a control frame. |
78 | * Can we forward it? | |
1da177e4 | 79 | */ |
95a9dc43 AH |
80 | |
81 | if (x25_forward_data(lci, nb, skb)) { | |
82 | if (frametype == X25_CLEAR_CONFIRMATION) { | |
83 | x25_clear_forward_by_lci(lci); | |
84 | } | |
85 | kfree_skb(skb); | |
86 | return 1; | |
87 | } | |
88 | ||
1da177e4 LT |
89 | /* |
90 | x25_transmit_clear_request(nb, lci, 0x0D); | |
91 | */ | |
92 | ||
93 | if (frametype != X25_CLEAR_CONFIRMATION) | |
b73e9e3c | 94 | pr_debug("x25_receive_data(): unknown frame type %2x\n",frametype); |
1da177e4 LT |
95 | |
96 | return 0; | |
97 | } | |
98 | ||
99 | int x25_lapb_receive_frame(struct sk_buff *skb, struct net_device *dev, | |
f2ccd8fa | 100 | struct packet_type *ptype, struct net_device *orig_dev) |
1da177e4 LT |
101 | { |
102 | struct sk_buff *nskb; | |
103 | struct x25_neigh *nb; | |
104 | ||
721499e8 | 105 | if (!net_eq(dev_net(dev), &init_net)) |
e730c155 EB |
106 | goto drop; |
107 | ||
1da177e4 LT |
108 | nskb = skb_copy(skb, GFP_ATOMIC); |
109 | if (!nskb) | |
110 | goto drop; | |
111 | kfree_skb(skb); | |
112 | skb = nskb; | |
113 | ||
114 | /* | |
115 | * Packet received from unrecognised device, throw it away. | |
116 | */ | |
117 | nb = x25_get_neigh(dev); | |
118 | if (!nb) { | |
b73e9e3c | 119 | pr_debug("unknown neighbour - %s\n", dev->name); |
1da177e4 LT |
120 | goto drop; |
121 | } | |
122 | ||
cb101ed2 MD |
123 | if (!pskb_may_pull(skb, 1)) |
124 | return 0; | |
125 | ||
1da177e4 | 126 | switch (skb->data[0]) { |
5ebfbc06 AH |
127 | |
128 | case X25_IFACE_DATA: | |
129 | skb_pull(skb, 1); | |
130 | if (x25_receive_data(skb, nb)) { | |
131 | x25_neigh_put(nb); | |
132 | goto out; | |
133 | } | |
134 | break; | |
135 | ||
136 | case X25_IFACE_CONNECT: | |
137 | x25_link_established(nb); | |
138 | break; | |
139 | ||
140 | case X25_IFACE_DISCONNECT: | |
141 | x25_link_terminated(nb); | |
142 | break; | |
1da177e4 LT |
143 | } |
144 | x25_neigh_put(nb); | |
145 | drop: | |
146 | kfree_skb(skb); | |
147 | out: | |
148 | return 0; | |
149 | } | |
150 | ||
151 | void x25_establish_link(struct x25_neigh *nb) | |
152 | { | |
153 | struct sk_buff *skb; | |
154 | unsigned char *ptr; | |
155 | ||
156 | switch (nb->dev->type) { | |
fddc5f3e JP |
157 | case ARPHRD_X25: |
158 | if ((skb = alloc_skb(1, GFP_ATOMIC)) == NULL) { | |
b73e9e3c | 159 | pr_err("x25_dev: out of memory\n"); |
fddc5f3e JP |
160 | return; |
161 | } | |
162 | ptr = skb_put(skb, 1); | |
163 | *ptr = X25_IFACE_CONNECT; | |
164 | break; | |
1da177e4 | 165 | |
29c36262 | 166 | #if IS_ENABLED(CONFIG_LLC) |
fddc5f3e JP |
167 | case ARPHRD_ETHER: |
168 | return; | |
1da177e4 | 169 | #endif |
fddc5f3e JP |
170 | default: |
171 | return; | |
1da177e4 LT |
172 | } |
173 | ||
174 | skb->protocol = htons(ETH_P_X25); | |
175 | skb->dev = nb->dev; | |
176 | ||
177 | dev_queue_xmit(skb); | |
178 | } | |
179 | ||
180 | void x25_terminate_link(struct x25_neigh *nb) | |
181 | { | |
182 | struct sk_buff *skb; | |
183 | unsigned char *ptr; | |
184 | ||
29c36262 | 185 | #if IS_ENABLED(CONFIG_LLC) |
1da177e4 LT |
186 | if (nb->dev->type == ARPHRD_ETHER) |
187 | return; | |
188 | #endif | |
189 | if (nb->dev->type != ARPHRD_X25) | |
190 | return; | |
191 | ||
192 | skb = alloc_skb(1, GFP_ATOMIC); | |
193 | if (!skb) { | |
b73e9e3c | 194 | pr_err("x25_dev: out of memory\n"); |
1da177e4 LT |
195 | return; |
196 | } | |
197 | ||
198 | ptr = skb_put(skb, 1); | |
5ebfbc06 | 199 | *ptr = X25_IFACE_DISCONNECT; |
1da177e4 LT |
200 | |
201 | skb->protocol = htons(ETH_P_X25); | |
202 | skb->dev = nb->dev; | |
203 | dev_queue_xmit(skb); | |
204 | } | |
205 | ||
206 | void x25_send_frame(struct sk_buff *skb, struct x25_neigh *nb) | |
207 | { | |
208 | unsigned char *dptr; | |
209 | ||
c1d2bbe1 | 210 | skb_reset_network_header(skb); |
1da177e4 LT |
211 | |
212 | switch (nb->dev->type) { | |
fddc5f3e JP |
213 | case ARPHRD_X25: |
214 | dptr = skb_push(skb, 1); | |
215 | *dptr = X25_IFACE_DATA; | |
216 | break; | |
1da177e4 | 217 | |
29c36262 | 218 | #if IS_ENABLED(CONFIG_LLC) |
fddc5f3e JP |
219 | case ARPHRD_ETHER: |
220 | kfree_skb(skb); | |
221 | return; | |
1da177e4 | 222 | #endif |
fddc5f3e JP |
223 | default: |
224 | kfree_skb(skb); | |
225 | return; | |
1da177e4 LT |
226 | } |
227 | ||
228 | skb->protocol = htons(ETH_P_X25); | |
229 | skb->dev = nb->dev; | |
230 | ||
231 | dev_queue_xmit(skb); | |
232 | } |