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TOMOYO Linux Cross Reference
Linux/net/nfc/nci/data.c

Version: ~ [ linux-5.6-rc1 ] ~ [ linux-5.5.2 ] ~ [ linux-5.4.17 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.102 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.170 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.213 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.213 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.81 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  *  The NFC Controller Interface is the communication protocol between an
  3  *  NFC Controller (NFCC) and a Device Host (DH).
  4  *
  5  *  Copyright (C) 2011 Texas Instruments, Inc.
  6  *
  7  *  Written by Ilan Elias <ilane@ti.com>
  8  *
  9  *  This program is free software; you can redistribute it and/or modify
 10  *  it under the terms of the GNU General Public License version 2
 11  *  as published by the Free Software Foundation
 12  *
 13  *  This program is distributed in the hope that it will be useful,
 14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 16  *  GNU General Public License for more details.
 17  *
 18  *  You should have received a copy of the GNU General Public License
 19  *  along with this program; if not, write to the Free Software
 20  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 21  *
 22  */
 23 
 24 #define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__
 25 
 26 #include <linux/types.h>
 27 #include <linux/interrupt.h>
 28 #include <linux/wait.h>
 29 #include <linux/bitops.h>
 30 #include <linux/skbuff.h>
 31 
 32 #include "../nfc.h"
 33 #include <net/nfc/nci.h>
 34 #include <net/nfc/nci_core.h>
 35 #include <linux/nfc.h>
 36 
 37 /* Complete data exchange transaction and forward skb to nfc core */
 38 void nci_data_exchange_complete(struct nci_dev *ndev, struct sk_buff *skb,
 39                                 int err)
 40 {
 41         data_exchange_cb_t cb = ndev->data_exchange_cb;
 42         void *cb_context = ndev->data_exchange_cb_context;
 43 
 44         pr_debug("len %d, err %d\n", skb ? skb->len : 0, err);
 45 
 46         /* data exchange is complete, stop the data timer */
 47         del_timer_sync(&ndev->data_timer);
 48         clear_bit(NCI_DATA_EXCHANGE_TO, &ndev->flags);
 49 
 50         if (cb) {
 51                 ndev->data_exchange_cb = NULL;
 52                 ndev->data_exchange_cb_context = NULL;
 53 
 54                 /* forward skb to nfc core */
 55                 cb(cb_context, skb, err);
 56         } else if (skb) {
 57                 pr_err("no rx callback, dropping rx data...\n");
 58 
 59                 /* no waiting callback, free skb */
 60                 kfree_skb(skb);
 61         }
 62 
 63         clear_bit(NCI_DATA_EXCHANGE, &ndev->flags);
 64 }
 65 
 66 /* ----------------- NCI TX Data ----------------- */
 67 
 68 static inline void nci_push_data_hdr(struct nci_dev *ndev,
 69                                      __u8 conn_id,
 70                                      struct sk_buff *skb,
 71                                      __u8 pbf)
 72 {
 73         struct nci_data_hdr *hdr;
 74         int plen = skb->len;
 75 
 76         hdr = (struct nci_data_hdr *) skb_push(skb, NCI_DATA_HDR_SIZE);
 77         hdr->conn_id = conn_id;
 78         hdr->rfu = 0;
 79         hdr->plen = plen;
 80 
 81         nci_mt_set((__u8 *)hdr, NCI_MT_DATA_PKT);
 82         nci_pbf_set((__u8 *)hdr, pbf);
 83 
 84         skb->dev = (void *) ndev;
 85 }
 86 
 87 static int nci_queue_tx_data_frags(struct nci_dev *ndev,
 88                                    __u8 conn_id,
 89                                    struct sk_buff *skb) {
 90         int total_len = skb->len;
 91         unsigned char *data = skb->data;
 92         unsigned long flags;
 93         struct sk_buff_head frags_q;
 94         struct sk_buff *skb_frag;
 95         int frag_len;
 96         int rc = 0;
 97 
 98         pr_debug("conn_id 0x%x, total_len %d\n", conn_id, total_len);
 99 
100         __skb_queue_head_init(&frags_q);
101 
102         while (total_len) {
103                 frag_len =
104                         min_t(int, total_len, ndev->max_data_pkt_payload_size);
105 
106                 skb_frag = nci_skb_alloc(ndev,
107                                          (NCI_DATA_HDR_SIZE + frag_len),
108                                          GFP_KERNEL);
109                 if (skb_frag == NULL) {
110                         rc = -ENOMEM;
111                         goto free_exit;
112                 }
113                 skb_reserve(skb_frag, NCI_DATA_HDR_SIZE);
114 
115                 /* first, copy the data */
116                 memcpy(skb_put(skb_frag, frag_len), data, frag_len);
117 
118                 /* second, set the header */
119                 nci_push_data_hdr(ndev, conn_id, skb_frag,
120                                   ((total_len == frag_len) ?
121                                    (NCI_PBF_LAST) : (NCI_PBF_CONT)));
122 
123                 __skb_queue_tail(&frags_q, skb_frag);
124 
125                 data += frag_len;
126                 total_len -= frag_len;
127 
128                 pr_debug("frag_len %d, remaining total_len %d\n",
129                          frag_len, total_len);
130         }
131 
132         /* queue all fragments atomically */
133         spin_lock_irqsave(&ndev->tx_q.lock, flags);
134 
135         while ((skb_frag = __skb_dequeue(&frags_q)) != NULL)
136                 __skb_queue_tail(&ndev->tx_q, skb_frag);
137 
138         spin_unlock_irqrestore(&ndev->tx_q.lock, flags);
139 
140         /* free the original skb */
141         kfree_skb(skb);
142 
143         goto exit;
144 
145 free_exit:
146         while ((skb_frag = __skb_dequeue(&frags_q)) != NULL)
147                 kfree_skb(skb_frag);
148 
149 exit:
150         return rc;
151 }
152 
153 /* Send NCI data */
154 int nci_send_data(struct nci_dev *ndev, __u8 conn_id, struct sk_buff *skb)
155 {
156         int rc = 0;
157 
158         pr_debug("conn_id 0x%x, plen %d\n", conn_id, skb->len);
159 
160         /* check if the packet need to be fragmented */
161         if (skb->len <= ndev->max_data_pkt_payload_size) {
162                 /* no need to fragment packet */
163                 nci_push_data_hdr(ndev, conn_id, skb, NCI_PBF_LAST);
164 
165                 skb_queue_tail(&ndev->tx_q, skb);
166         } else {
167                 /* fragment packet and queue the fragments */
168                 rc = nci_queue_tx_data_frags(ndev, conn_id, skb);
169                 if (rc) {
170                         pr_err("failed to fragment tx data packet\n");
171                         goto free_exit;
172                 }
173         }
174 
175         queue_work(ndev->tx_wq, &ndev->tx_work);
176 
177         goto exit;
178 
179 free_exit:
180         kfree_skb(skb);
181 
182 exit:
183         return rc;
184 }
185 
186 /* ----------------- NCI RX Data ----------------- */
187 
188 static void nci_add_rx_data_frag(struct nci_dev *ndev,
189                                  struct sk_buff *skb,
190                                  __u8 pbf)
191 {
192         int reassembly_len;
193         int err = 0;
194 
195         if (ndev->rx_data_reassembly) {
196                 reassembly_len = ndev->rx_data_reassembly->len;
197 
198                 /* first, make enough room for the already accumulated data */
199                 if (skb_cow_head(skb, reassembly_len)) {
200                         pr_err("error adding room for accumulated rx data\n");
201 
202                         kfree_skb(skb);
203                         skb = NULL;
204 
205                         kfree_skb(ndev->rx_data_reassembly);
206                         ndev->rx_data_reassembly = NULL;
207 
208                         err = -ENOMEM;
209                         goto exit;
210                 }
211 
212                 /* second, combine the two fragments */
213                 memcpy(skb_push(skb, reassembly_len),
214                        ndev->rx_data_reassembly->data,
215                        reassembly_len);
216 
217                 /* third, free old reassembly */
218                 kfree_skb(ndev->rx_data_reassembly);
219                 ndev->rx_data_reassembly = NULL;
220         }
221 
222         if (pbf == NCI_PBF_CONT) {
223                 /* need to wait for next fragment, store skb and exit */
224                 ndev->rx_data_reassembly = skb;
225                 return;
226         }
227 
228 exit:
229         nci_data_exchange_complete(ndev, skb, err);
230 }
231 
232 /* Rx Data packet */
233 void nci_rx_data_packet(struct nci_dev *ndev, struct sk_buff *skb)
234 {
235         __u8 pbf = nci_pbf(skb->data);
236 
237         pr_debug("len %d\n", skb->len);
238 
239         pr_debug("NCI RX: MT=data, PBF=%d, conn_id=%d, plen=%d\n",
240                  nci_pbf(skb->data),
241                  nci_conn_id(skb->data),
242                  nci_plen(skb->data));
243 
244         /* strip the nci data header */
245         skb_pull(skb, NCI_DATA_HDR_SIZE);
246 
247         if (ndev->target_active_prot == NFC_PROTO_MIFARE) {
248                 /* frame I/F => remove the status byte */
249                 pr_debug("NFC_PROTO_MIFARE => remove the status byte\n");
250                 skb_trim(skb, (skb->len - 1));
251         }
252 
253         nci_add_rx_data_frag(ndev, skb, pbf);
254 }
255 

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