Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[linux-btrfs-devel.git] / net / caif / cfrfml.c
blob81660f8097131f2c7cb952e7a1f6d51ba2ce3a40
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 */
7 #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
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>
17 #define container_obj(layr) container_of(layr, struct cfrfml, serv.layer)
18 #define RFM_SEGMENTATION_BIT 0x01
19 #define RFM_HEAD_SIZE 7
21 static int cfrfml_receive(struct cflayer *layr, struct cfpkt *pkt);
22 static int cfrfml_transmit(struct cflayer *layr, struct cfpkt *pkt);
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;
34 static void cfrfml_release(struct cflayer *layer)
36 struct cfsrvl *srvl = container_of(layer, struct cfsrvl, layer);
37 struct cfrfml *rfml = container_obj(&srvl->layer);
39 if (rfml->incomplete_frm)
40 cfpkt_destroy(rfml->incomplete_frm);
42 kfree(srvl);
45 struct cflayer *cfrfml_create(u8 channel_id, struct dev_info *dev_info,
46 int mtu_size)
48 int tmp;
49 struct cfrfml *this = kzalloc(sizeof(struct cfrfml), GFP_ATOMIC);
51 if (!this)
52 return NULL;
54 cfsrvl_init(&this->serv, channel_id, dev_info, false);
55 this->serv.release = cfrfml_release;
56 this->serv.layer.receive = cfrfml_receive;
57 this->serv.layer.transmit = cfrfml_transmit;
59 /* Round down to closest multiple of 16 */
60 tmp = (mtu_size - RFM_HEAD_SIZE - 6) / 16;
61 tmp *= 16;
63 this->fragment_size = tmp;
64 spin_lock_init(&this->sync);
65 snprintf(this->serv.layer.name, CAIF_LAYER_NAME_SZ,
66 "rfm%d", channel_id);
68 return &this->serv.layer;
71 static struct cfpkt *rfm_append(struct cfrfml *rfml, char *seghead,
72 struct cfpkt *pkt, int *err)
74 struct cfpkt *tmppkt;
75 *err = -EPROTO;
76 /* n-th but not last segment */
78 if (cfpkt_extr_head(pkt, seghead, 6) < 0)
79 return NULL;
81 /* Verify correct header */
82 if (memcmp(seghead, rfml->seghead, 6) != 0)
83 return NULL;
85 tmppkt = cfpkt_append(rfml->incomplete_frm, pkt,
86 rfml->pdu_size + RFM_HEAD_SIZE);
88 /* If cfpkt_append failes input pkts are not freed */
89 *err = -ENOMEM;
90 if (tmppkt == NULL)
91 return NULL;
93 *err = 0;
94 return tmppkt;
97 static int cfrfml_receive(struct cflayer *layr, struct cfpkt *pkt)
99 u8 tmp;
100 bool segmented;
101 int err;
102 u8 seghead[6];
103 struct cfrfml *rfml;
104 struct cfpkt *tmppkt = NULL;
106 caif_assert(layr->up != NULL);
107 caif_assert(layr->receive != NULL);
108 rfml = container_obj(layr);
109 spin_lock(&rfml->sync);
111 err = -EPROTO;
112 if (cfpkt_extr_head(pkt, &tmp, 1) < 0)
113 goto out;
114 segmented = tmp & RFM_SEGMENTATION_BIT;
116 if (segmented) {
117 if (rfml->incomplete_frm == NULL) {
118 /* Initial Segment */
119 if (cfpkt_peek_head(pkt, rfml->seghead, 6) < 0)
120 goto out;
122 rfml->pdu_size = get_unaligned_le16(rfml->seghead+4);
124 if (cfpkt_erroneous(pkt))
125 goto out;
126 rfml->incomplete_frm = pkt;
127 pkt = NULL;
128 } else {
130 tmppkt = rfm_append(rfml, seghead, pkt, &err);
131 if (tmppkt == NULL)
132 goto out;
134 if (cfpkt_erroneous(tmppkt))
135 goto out;
137 rfml->incomplete_frm = tmppkt;
140 if (cfpkt_erroneous(tmppkt))
141 goto out;
143 err = 0;
144 goto out;
147 if (rfml->incomplete_frm) {
149 /* Last Segment */
150 tmppkt = rfm_append(rfml, seghead, pkt, &err);
151 if (tmppkt == NULL)
152 goto out;
154 if (cfpkt_erroneous(tmppkt))
155 goto out;
157 rfml->incomplete_frm = NULL;
158 pkt = tmppkt;
159 tmppkt = NULL;
161 /* Verify that length is correct */
162 err = EPROTO;
163 if (rfml->pdu_size != cfpkt_getlen(pkt) - RFM_HEAD_SIZE + 1)
164 goto out;
167 err = rfml->serv.layer.up->receive(rfml->serv.layer.up, pkt);
169 out:
171 if (err != 0) {
172 if (tmppkt)
173 cfpkt_destroy(tmppkt);
174 if (pkt)
175 cfpkt_destroy(pkt);
176 if (rfml->incomplete_frm)
177 cfpkt_destroy(rfml->incomplete_frm);
178 rfml->incomplete_frm = NULL;
180 pr_info("Connection error %d triggered on RFM link\n", err);
182 /* Trigger connection error upon failure.*/
183 layr->up->ctrlcmd(layr->up, CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND,
184 rfml->serv.dev_info.id);
186 spin_unlock(&rfml->sync);
187 return err;
191 static int cfrfml_transmit_segment(struct cfrfml *rfml, struct cfpkt *pkt)
193 caif_assert(cfpkt_getlen(pkt) < rfml->fragment_size);
195 /* Add info for MUX-layer to route the packet out. */
196 cfpkt_info(pkt)->channel_id = rfml->serv.layer.id;
199 * To optimize alignment, we add up the size of CAIF header before
200 * payload.
202 cfpkt_info(pkt)->hdr_len = RFM_HEAD_SIZE;
203 cfpkt_info(pkt)->dev_info = &rfml->serv.dev_info;
205 return rfml->serv.layer.dn->transmit(rfml->serv.layer.dn, pkt);
208 static int cfrfml_transmit(struct cflayer *layr, struct cfpkt *pkt)
210 int err;
211 u8 seg;
212 u8 head[6];
213 struct cfpkt *rearpkt = NULL;
214 struct cfpkt *frontpkt = pkt;
215 struct cfrfml *rfml = container_obj(layr);
217 caif_assert(layr->dn != NULL);
218 caif_assert(layr->dn->transmit != NULL);
220 if (!cfsrvl_ready(&rfml->serv, &err))
221 return err;
223 err = -EPROTO;
224 if (cfpkt_getlen(pkt) <= RFM_HEAD_SIZE-1)
225 goto out;
227 err = 0;
228 if (cfpkt_getlen(pkt) > rfml->fragment_size + RFM_HEAD_SIZE)
229 err = cfpkt_peek_head(pkt, head, 6);
231 if (err < 0)
232 goto out;
234 while (cfpkt_getlen(frontpkt) > rfml->fragment_size + RFM_HEAD_SIZE) {
236 seg = 1;
237 err = -EPROTO;
239 if (cfpkt_add_head(frontpkt, &seg, 1) < 0)
240 goto out;
242 * On OOM error cfpkt_split returns NULL.
244 * NOTE: Segmented pdu is not correctly aligned.
245 * This has negative performance impact.
248 rearpkt = cfpkt_split(frontpkt, rfml->fragment_size);
249 if (rearpkt == NULL)
250 goto out;
252 err = cfrfml_transmit_segment(rfml, frontpkt);
254 if (err != 0)
255 goto out;
256 frontpkt = rearpkt;
257 rearpkt = NULL;
259 err = -ENOMEM;
260 if (frontpkt == NULL)
261 goto out;
262 err = -EPROTO;
263 if (cfpkt_add_head(frontpkt, head, 6) < 0)
264 goto out;
268 seg = 0;
269 err = -EPROTO;
271 if (cfpkt_add_head(frontpkt, &seg, 1) < 0)
272 goto out;
274 err = cfrfml_transmit_segment(rfml, frontpkt);
276 frontpkt = NULL;
277 out:
279 if (err != 0) {
280 pr_info("Connection error %d triggered on RFM link\n", err);
281 /* Trigger connection error upon failure.*/
283 layr->up->ctrlcmd(layr->up, CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND,
284 rfml->serv.dev_info.id);
286 if (rearpkt)
287 cfpkt_destroy(rearpkt);
289 if (frontpkt && frontpkt != pkt) {
291 cfpkt_destroy(frontpkt);
293 * Socket layer will free the original packet,
294 * but this packet may already be sent and
295 * freed. So we have to return 0 in this case
296 * to avoid socket layer to re-free this packet.
297 * The return of shutdown indication will
298 * cause connection to be invalidated anyhow.
300 err = 0;
304 return err;