Commit | Line | Data |
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2b27bdcc | 1 | // SPDX-License-Identifier: GPL-2.0-only |
02a47617 RDC |
2 | /* |
3 | * File: pep-gprs.c | |
4 | * | |
5 | * GPRS over Phonet pipe end point socket | |
6 | * | |
7 | * Copyright (C) 2008 Nokia Corporation. | |
8 | * | |
31fdc555 | 9 | * Author: Rémi Denis-Courmont |
02a47617 RDC |
10 | */ |
11 | ||
12 | #include <linux/kernel.h> | |
13 | #include <linux/netdevice.h> | |
14 | #include <linux/if_ether.h> | |
15 | #include <linux/if_arp.h> | |
16 | #include <net/sock.h> | |
17 | ||
18 | #include <linux/if_phonet.h> | |
19 | #include <net/tcp_states.h> | |
20 | #include <net/phonet/gprs.h> | |
21 | ||
22 | #define GPRS_DEFAULT_MTU 1400 | |
23 | ||
24 | struct gprs_dev { | |
25 | struct sock *sk; | |
26 | void (*old_state_change)(struct sock *); | |
676d2369 | 27 | void (*old_data_ready)(struct sock *); |
02a47617 RDC |
28 | void (*old_write_space)(struct sock *); |
29 | ||
09a2c3c0 | 30 | struct net_device *dev; |
02a47617 RDC |
31 | }; |
32 | ||
5c7f0333 | 33 | static __be16 gprs_type_trans(struct sk_buff *skb) |
02a47617 RDC |
34 | { |
35 | const u8 *pvfc; | |
36 | u8 buf; | |
37 | ||
38 | pvfc = skb_header_pointer(skb, 0, 1, &buf); | |
39 | if (!pvfc) | |
5c7f0333 | 40 | return htons(0); |
02a47617 RDC |
41 | /* Look at IP version field */ |
42 | switch (*pvfc >> 4) { | |
43 | case 4: | |
44 | return htons(ETH_P_IP); | |
45 | case 6: | |
46 | return htons(ETH_P_IPV6); | |
47 | } | |
5c7f0333 | 48 | return htons(0); |
02a47617 RDC |
49 | } |
50 | ||
893873f3 RDC |
51 | static void gprs_writeable(struct gprs_dev *gp) |
52 | { | |
53 | struct net_device *dev = gp->dev; | |
54 | ||
55 | if (pep_writeable(gp->sk)) | |
56 | netif_wake_queue(dev); | |
57 | } | |
58 | ||
02a47617 RDC |
59 | /* |
60 | * Socket callbacks | |
61 | */ | |
62 | ||
63 | static void gprs_state_change(struct sock *sk) | |
64 | { | |
09a2c3c0 | 65 | struct gprs_dev *gp = sk->sk_user_data; |
02a47617 RDC |
66 | |
67 | if (sk->sk_state == TCP_CLOSE_WAIT) { | |
09a2c3c0 RDC |
68 | struct net_device *dev = gp->dev; |
69 | ||
70 | netif_stop_queue(dev); | |
71 | netif_carrier_off(dev); | |
02a47617 RDC |
72 | } |
73 | } | |
74 | ||
09a2c3c0 | 75 | static int gprs_recv(struct gprs_dev *gp, struct sk_buff *skb) |
02a47617 | 76 | { |
09a2c3c0 | 77 | struct net_device *dev = gp->dev; |
02a47617 | 78 | int err = 0; |
5c7f0333 | 79 | __be16 protocol = gprs_type_trans(skb); |
02a47617 RDC |
80 | |
81 | if (!protocol) { | |
82 | err = -EINVAL; | |
83 | goto drop; | |
84 | } | |
85 | ||
fc6a1107 | 86 | if (skb_headroom(skb) & 3) { |
02a47617 RDC |
87 | struct sk_buff *rskb, *fs; |
88 | int flen = 0; | |
89 | ||
fc6a1107 | 90 | /* Phonet Pipe data header may be misaligned (3 bytes), |
02a47617 RDC |
91 | * so wrap the IP packet as a single fragment of an head-less |
92 | * socket buffer. The network stack will pull what it needs, | |
93 | * but at least, the whole IP payload is not memcpy'd. */ | |
09a2c3c0 | 94 | rskb = netdev_alloc_skb(dev, 0); |
02a47617 RDC |
95 | if (!rskb) { |
96 | err = -ENOBUFS; | |
97 | goto drop; | |
98 | } | |
99 | skb_shinfo(rskb)->frag_list = skb; | |
100 | rskb->len += skb->len; | |
101 | rskb->data_len += rskb->len; | |
102 | rskb->truesize += rskb->len; | |
103 | ||
104 | /* Avoid nested fragments */ | |
5c313e9a | 105 | skb_walk_frags(skb, fs) |
02a47617 RDC |
106 | flen += fs->len; |
107 | skb->next = skb_shinfo(skb)->frag_list; | |
5c313e9a | 108 | skb_frag_list_init(skb); |
02a47617 RDC |
109 | skb->len -= flen; |
110 | skb->data_len -= flen; | |
111 | skb->truesize -= flen; | |
112 | ||
113 | skb = rskb; | |
114 | } | |
115 | ||
116 | skb->protocol = protocol; | |
117 | skb_reset_mac_header(skb); | |
09a2c3c0 | 118 | skb->dev = dev; |
02a47617 | 119 | |
09a2c3c0 RDC |
120 | if (likely(dev->flags & IFF_UP)) { |
121 | dev->stats.rx_packets++; | |
122 | dev->stats.rx_bytes += skb->len; | |
02a47617 RDC |
123 | netif_rx(skb); |
124 | skb = NULL; | |
125 | } else | |
126 | err = -ENODEV; | |
127 | ||
128 | drop: | |
129 | if (skb) { | |
130 | dev_kfree_skb(skb); | |
09a2c3c0 | 131 | dev->stats.rx_dropped++; |
02a47617 RDC |
132 | } |
133 | return err; | |
134 | } | |
135 | ||
676d2369 | 136 | static void gprs_data_ready(struct sock *sk) |
02a47617 | 137 | { |
09a2c3c0 | 138 | struct gprs_dev *gp = sk->sk_user_data; |
02a47617 RDC |
139 | struct sk_buff *skb; |
140 | ||
141 | while ((skb = pep_read(sk)) != NULL) { | |
142 | skb_orphan(skb); | |
09a2c3c0 | 143 | gprs_recv(gp, skb); |
02a47617 RDC |
144 | } |
145 | } | |
146 | ||
147 | static void gprs_write_space(struct sock *sk) | |
148 | { | |
09a2c3c0 | 149 | struct gprs_dev *gp = sk->sk_user_data; |
02a47617 | 150 | |
893873f3 RDC |
151 | if (netif_running(gp->dev)) |
152 | gprs_writeable(gp); | |
02a47617 RDC |
153 | } |
154 | ||
155 | /* | |
156 | * Network device callbacks | |
157 | */ | |
158 | ||
4798a2b8 RDC |
159 | static int gprs_open(struct net_device *dev) |
160 | { | |
161 | struct gprs_dev *gp = netdev_priv(dev); | |
162 | ||
893873f3 | 163 | gprs_writeable(gp); |
4798a2b8 RDC |
164 | return 0; |
165 | } | |
166 | ||
167 | static int gprs_close(struct net_device *dev) | |
168 | { | |
4798a2b8 | 169 | netif_stop_queue(dev); |
4798a2b8 RDC |
170 | return 0; |
171 | } | |
172 | ||
424efe9c | 173 | static netdev_tx_t gprs_xmit(struct sk_buff *skb, struct net_device *dev) |
02a47617 | 174 | { |
09a2c3c0 | 175 | struct gprs_dev *gp = netdev_priv(dev); |
893873f3 RDC |
176 | struct sock *sk = gp->sk; |
177 | int len, err; | |
02a47617 RDC |
178 | |
179 | switch (skb->protocol) { | |
180 | case htons(ETH_P_IP): | |
181 | case htons(ETH_P_IPV6): | |
182 | break; | |
183 | default: | |
184 | dev_kfree_skb(skb); | |
6ed10654 | 185 | return NETDEV_TX_OK; |
02a47617 RDC |
186 | } |
187 | ||
893873f3 RDC |
188 | skb_orphan(skb); |
189 | skb_set_owner_w(skb, sk); | |
190 | len = skb->len; | |
191 | err = pep_write(sk, skb); | |
192 | if (err) { | |
ba7a46f1 | 193 | net_dbg_ratelimited("%s: TX error (%d)\n", dev->name, err); |
893873f3 RDC |
194 | dev->stats.tx_aborted_errors++; |
195 | dev->stats.tx_errors++; | |
893873f3 | 196 | } else { |
09a2c3c0 | 197 | dev->stats.tx_packets++; |
893873f3 | 198 | dev->stats.tx_bytes += len; |
02a47617 RDC |
199 | } |
200 | ||
bbd5898d RDC |
201 | netif_stop_queue(dev); |
202 | if (pep_writeable(sk)) | |
203 | netif_wake_queue(dev); | |
6ed10654 | 204 | return NETDEV_TX_OK; |
02a47617 RDC |
205 | } |
206 | ||
ab638e69 SH |
207 | static const struct net_device_ops gprs_netdev_ops = { |
208 | .ndo_open = gprs_open, | |
209 | .ndo_stop = gprs_close, | |
210 | .ndo_start_xmit = gprs_xmit, | |
ab638e69 SH |
211 | }; |
212 | ||
09a2c3c0 | 213 | static void gprs_setup(struct net_device *dev) |
02a47617 | 214 | { |
09a2c3c0 | 215 | dev->features = NETIF_F_FRAGLIST; |
57c81fff | 216 | dev->type = ARPHRD_PHONET_PIPE; |
09a2c3c0 RDC |
217 | dev->flags = IFF_POINTOPOINT | IFF_NOARP; |
218 | dev->mtu = GPRS_DEFAULT_MTU; | |
b3e3893e JW |
219 | dev->min_mtu = 576; |
220 | dev->max_mtu = (PHONET_MAX_MTU - 11); | |
09a2c3c0 RDC |
221 | dev->hard_header_len = 0; |
222 | dev->addr_len = 0; | |
223 | dev->tx_queue_len = 10; | |
224 | ||
ab638e69 | 225 | dev->netdev_ops = &gprs_netdev_ops; |
cf124db5 | 226 | dev->needs_free_netdev = true; |
02a47617 RDC |
227 | } |
228 | ||
229 | /* | |
230 | * External interface | |
231 | */ | |
232 | ||
233 | /* | |
234 | * Attach a GPRS interface to a datagram socket. | |
235 | * Returns the interface index on success, negative error code on error. | |
236 | */ | |
237 | int gprs_attach(struct sock *sk) | |
238 | { | |
239 | static const char ifname[] = "gprs%d"; | |
09a2c3c0 RDC |
240 | struct gprs_dev *gp; |
241 | struct net_device *dev; | |
02a47617 RDC |
242 | int err; |
243 | ||
244 | if (unlikely(sk->sk_type == SOCK_STREAM)) | |
245 | return -EINVAL; /* need packet boundaries */ | |
246 | ||
247 | /* Create net device */ | |
c835a677 | 248 | dev = alloc_netdev(sizeof(*gp), ifname, NET_NAME_UNKNOWN, gprs_setup); |
09a2c3c0 | 249 | if (!dev) |
02a47617 | 250 | return -ENOMEM; |
09a2c3c0 | 251 | gp = netdev_priv(dev); |
893873f3 | 252 | gp->sk = sk; |
09a2c3c0 | 253 | gp->dev = dev; |
09a2c3c0 RDC |
254 | |
255 | netif_stop_queue(dev); | |
256 | err = register_netdev(dev); | |
02a47617 | 257 | if (err) { |
09a2c3c0 | 258 | free_netdev(dev); |
02a47617 RDC |
259 | return err; |
260 | } | |
261 | ||
262 | lock_sock(sk); | |
263 | if (unlikely(sk->sk_user_data)) { | |
264 | err = -EBUSY; | |
265 | goto out_rel; | |
266 | } | |
267 | if (unlikely((1 << sk->sk_state & (TCPF_CLOSE|TCPF_LISTEN)) || | |
268 | sock_flag(sk, SOCK_DEAD))) { | |
269 | err = -EINVAL; | |
270 | goto out_rel; | |
271 | } | |
09a2c3c0 RDC |
272 | sk->sk_user_data = gp; |
273 | gp->old_state_change = sk->sk_state_change; | |
274 | gp->old_data_ready = sk->sk_data_ready; | |
275 | gp->old_write_space = sk->sk_write_space; | |
02a47617 RDC |
276 | sk->sk_state_change = gprs_state_change; |
277 | sk->sk_data_ready = gprs_data_ready; | |
278 | sk->sk_write_space = gprs_write_space; | |
279 | release_sock(sk); | |
02a47617 | 280 | sock_hold(sk); |
02a47617 | 281 | |
09a2c3c0 RDC |
282 | printk(KERN_DEBUG"%s: attached\n", dev->name); |
283 | return dev->ifindex; | |
02a47617 RDC |
284 | |
285 | out_rel: | |
286 | release_sock(sk); | |
09a2c3c0 | 287 | unregister_netdev(dev); |
02a47617 RDC |
288 | return err; |
289 | } | |
290 | ||
291 | void gprs_detach(struct sock *sk) | |
292 | { | |
09a2c3c0 RDC |
293 | struct gprs_dev *gp = sk->sk_user_data; |
294 | struct net_device *dev = gp->dev; | |
02a47617 RDC |
295 | |
296 | lock_sock(sk); | |
297 | sk->sk_user_data = NULL; | |
09a2c3c0 RDC |
298 | sk->sk_state_change = gp->old_state_change; |
299 | sk->sk_data_ready = gp->old_data_ready; | |
300 | sk->sk_write_space = gp->old_write_space; | |
02a47617 RDC |
301 | release_sock(sk); |
302 | ||
09a2c3c0 RDC |
303 | printk(KERN_DEBUG"%s: detached\n", dev->name); |
304 | unregister_netdev(dev); | |
02a47617 | 305 | sock_put(sk); |
02a47617 | 306 | } |