ipv4: flush route cache after change accept_local
[linux-2.6.git] / net / caif / cfrfml.c
1 /*
2  * Copyright (C) ST-Ericsson AB 2010
3  * Author:      Sjur Brendeland/sjur.brandeland@stericsson.com
4  * License terms: GNU General Public License (GPL) version 2
5  */
6
7 #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
8
9 #include <linux/stddef.h>
10 #include <linux/spinlock.h>
11 #include <linux/slab.h>
12 #include <asm/unaligned.h>
13 #include <net/caif/caif_layer.h>
14 #include <net/caif/cfsrvl.h>
15 #include <net/caif/cfpkt.h>
16
17 #define container_obj(layr) container_of(layr, struct cfrfml, serv.layer)
18 #define RFM_SEGMENTATION_BIT 0x01
19 #define RFM_HEAD_SIZE 7
20
21 static int cfrfml_receive(struct cflayer *layr, struct cfpkt *pkt);
22 static int cfrfml_transmit(struct cflayer *layr, struct cfpkt *pkt);
23
24 struct cfrfml {
25         struct cfsrvl serv;
26         struct cfpkt *incomplete_frm;
27         int fragment_size;
28         u8  seghead[6];
29         u16 pdu_size;
30         /* Protects serialized processing of packets */
31         spinlock_t sync;
32 };
33
34 static void cfrfml_release(struct cflayer *layer)
35 {
36         struct cfsrvl *srvl = container_of(layer, struct cfsrvl, layer);
37         struct cfrfml *rfml = container_obj(&srvl->layer);
38
39         if (rfml->incomplete_frm)
40                 cfpkt_destroy(rfml->incomplete_frm);
41
42         kfree(srvl);
43 }
44
45 struct cflayer *cfrfml_create(u8 channel_id, struct dev_info *dev_info,
46                                         int mtu_size)
47 {
48         int tmp;
49         struct cfrfml *this =
50                 kzalloc(sizeof(struct cfrfml), GFP_ATOMIC);
51
52         if (!this) {
53                 pr_warn("Out of memory\n");
54                 return NULL;
55         }
56
57         cfsrvl_init(&this->serv, channel_id, dev_info, false);
58         this->serv.release = cfrfml_release;
59         this->serv.layer.receive = cfrfml_receive;
60         this->serv.layer.transmit = cfrfml_transmit;
61
62         /* Round down to closest multiple of 16 */
63         tmp = (mtu_size - RFM_HEAD_SIZE - 6) / 16;
64         tmp *= 16;
65
66         this->fragment_size = tmp;
67         spin_lock_init(&this->sync);
68         snprintf(this->serv.layer.name, CAIF_LAYER_NAME_SZ,
69                 "rfm%d", channel_id);
70
71         return &this->serv.layer;
72 }
73
74 static struct cfpkt *rfm_append(struct cfrfml *rfml, char *seghead,
75                         struct cfpkt *pkt, int *err)
76 {
77         struct cfpkt *tmppkt;
78         *err = -EPROTO;
79         /* n-th but not last segment */
80
81         if (cfpkt_extr_head(pkt, seghead, 6) < 0)
82                 return NULL;
83
84         /* Verify correct header */
85         if (memcmp(seghead, rfml->seghead, 6) != 0)
86                 return NULL;
87
88         tmppkt = cfpkt_append(rfml->incomplete_frm, pkt,
89                         rfml->pdu_size + RFM_HEAD_SIZE);
90
91         /* If cfpkt_append failes input pkts are not freed */
92         *err = -ENOMEM;
93         if (tmppkt == NULL)
94                 return NULL;
95
96         *err = 0;
97         return tmppkt;
98 }
99
100 static int cfrfml_receive(struct cflayer *layr, struct cfpkt *pkt)
101 {
102         u8 tmp;
103         bool segmented;
104         int err;
105         u8 seghead[6];
106         struct cfrfml *rfml;
107         struct cfpkt *tmppkt = NULL;
108
109         caif_assert(layr->up != NULL);
110         caif_assert(layr->receive != NULL);
111         rfml = container_obj(layr);
112         spin_lock(&rfml->sync);
113
114         err = -EPROTO;
115         if (cfpkt_extr_head(pkt, &tmp, 1) < 0)
116                 goto out;
117         segmented = tmp & RFM_SEGMENTATION_BIT;
118
119         if (segmented) {
120                 if (rfml->incomplete_frm == NULL) {
121                         /* Initial Segment */
122                         if (cfpkt_peek_head(pkt, rfml->seghead, 6) < 0)
123                                 goto out;
124
125                         rfml->pdu_size = get_unaligned_le16(rfml->seghead+4);
126
127                         if (cfpkt_erroneous(pkt))
128                                 goto out;
129                         rfml->incomplete_frm = pkt;
130                         pkt = NULL;
131                 } else {
132
133                         tmppkt = rfm_append(rfml, seghead, pkt, &err);
134                         if (tmppkt == NULL)
135                                 goto out;
136
137                         if (cfpkt_erroneous(tmppkt))
138                                 goto out;
139
140                         rfml->incomplete_frm = tmppkt;
141
142
143                         if (cfpkt_erroneous(tmppkt))
144                                 goto out;
145                 }
146                 err = 0;
147                 goto out;
148         }
149
150         if (rfml->incomplete_frm) {
151
152                 /* Last Segment */
153                 tmppkt = rfm_append(rfml, seghead, pkt, &err);
154                 if (tmppkt == NULL)
155                         goto out;
156
157                 if (cfpkt_erroneous(tmppkt))
158                         goto out;
159
160                 rfml->incomplete_frm = NULL;
161                 pkt = tmppkt;
162                 tmppkt = NULL;
163
164                 /* Verify that length is correct */
165                 err = EPROTO;
166                 if (rfml->pdu_size != cfpkt_getlen(pkt) - RFM_HEAD_SIZE + 1)
167                         goto out;
168         }
169
170         err = rfml->serv.layer.up->receive(rfml->serv.layer.up, pkt);
171
172 out:
173
174         if (err != 0) {
175                 if (tmppkt)
176                         cfpkt_destroy(tmppkt);
177                 if (pkt)
178                         cfpkt_destroy(pkt);
179                 if (rfml->incomplete_frm)
180                         cfpkt_destroy(rfml->incomplete_frm);
181                 rfml->incomplete_frm = NULL;
182
183                 pr_info("Connection error %d triggered on RFM link\n", err);
184
185                 /* Trigger connection error upon failure.*/
186                 layr->up->ctrlcmd(layr->up, CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND,
187                                         rfml->serv.dev_info.id);
188         }
189         spin_unlock(&rfml->sync);
190         return err;
191 }
192
193
194 static int cfrfml_transmit_segment(struct cfrfml *rfml, struct cfpkt *pkt)
195 {
196         caif_assert(cfpkt_getlen(pkt) < rfml->fragment_size);
197
198         /* Add info for MUX-layer to route the packet out. */
199         cfpkt_info(pkt)->channel_id = rfml->serv.layer.id;
200
201         /*
202          * To optimize alignment, we add up the size of CAIF header before
203          * payload.
204          */
205         cfpkt_info(pkt)->hdr_len = RFM_HEAD_SIZE;
206         cfpkt_info(pkt)->dev_info = &rfml->serv.dev_info;
207
208         return rfml->serv.layer.dn->transmit(rfml->serv.layer.dn, pkt);
209 }
210
211 static int cfrfml_transmit(struct cflayer *layr, struct cfpkt *pkt)
212 {
213         int err;
214         u8 seg;
215         u8 head[6];
216         struct cfpkt *rearpkt = NULL;
217         struct cfpkt *frontpkt = pkt;
218         struct cfrfml *rfml = container_obj(layr);
219
220         caif_assert(layr->dn != NULL);
221         caif_assert(layr->dn->transmit != NULL);
222
223         if (!cfsrvl_ready(&rfml->serv, &err))
224                 return err;
225
226         err = -EPROTO;
227         if (cfpkt_getlen(pkt) <= RFM_HEAD_SIZE-1)
228                 goto out;
229
230         err = 0;
231         if (cfpkt_getlen(pkt) > rfml->fragment_size + RFM_HEAD_SIZE)
232                 err = cfpkt_peek_head(pkt, head, 6);
233
234         if (err < 0)
235                 goto out;
236
237         while (cfpkt_getlen(frontpkt) > rfml->fragment_size + RFM_HEAD_SIZE) {
238
239                 seg = 1;
240                 err = -EPROTO;
241
242                 if (cfpkt_add_head(frontpkt, &seg, 1) < 0)
243                         goto out;
244                 /*
245                  * On OOM error cfpkt_split returns NULL.
246                  *
247                  * NOTE: Segmented pdu is not correctly aligned.
248                  * This has negative performance impact.
249                  */
250
251                 rearpkt = cfpkt_split(frontpkt, rfml->fragment_size);
252                 if (rearpkt == NULL)
253                         goto out;
254
255                 err = cfrfml_transmit_segment(rfml, frontpkt);
256
257                 if (err != 0)
258                         goto out;
259                 frontpkt = rearpkt;
260                 rearpkt = NULL;
261
262                 err = -ENOMEM;
263                 if (frontpkt == NULL)
264                         goto out;
265                 err = -EPROTO;
266                 if (cfpkt_add_head(frontpkt, head, 6) < 0)
267                         goto out;
268
269         }
270
271         seg = 0;
272         err = -EPROTO;
273
274         if (cfpkt_add_head(frontpkt, &seg, 1) < 0)
275                 goto out;
276
277         err = cfrfml_transmit_segment(rfml, frontpkt);
278
279         frontpkt = NULL;
280 out:
281
282         if (err != 0) {
283                 pr_info("Connection error %d triggered on RFM link\n", err);
284                 /* Trigger connection error upon failure.*/
285
286                 layr->up->ctrlcmd(layr->up, CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND,
287                                         rfml->serv.dev_info.id);
288
289                 if (rearpkt)
290                         cfpkt_destroy(rearpkt);
291
292                 if (frontpkt && frontpkt != pkt) {
293
294                         cfpkt_destroy(frontpkt);
295                         /*
296                          * Socket layer will free the original packet,
297                          * but this packet may already be sent and
298                          * freed. So we have to return 0 in this case
299                          * to avoid socket layer to re-free this packet.
300                          * The return of shutdown indication will
301                          * cause connection to be invalidated anyhow.
302                          */
303                         err = 0;
304                 }
305         }
306
307         return err;
308 }