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 <net/caif/caif_layer.h>
13 #include <net/caif/cfsrvl.h>
14 #include <net/caif/cfpkt.h>
15
16
17 #define container_obj(layr) ((struct cfsrvl *) layr)
18
19 #define DGM_CMD_BIT 0x80
20 #define DGM_FLOW_OFF 0x81
21 #define DGM_FLOW_ON 0x80
22 #define DGM_MTU 1500
23
24 static int cfdgml_receive(struct cflayer *layr, struct cfpkt *pkt);
25 static int cfdgml_transmit(struct cflayer *layr, struct cfpkt *pkt);
26
cfdgml_create(u8 channel_id,struct dev_info * dev_info)27 struct cflayer *cfdgml_create(u8 channel_id, struct dev_info *dev_info)
28 {
29 struct cfsrvl *dgm = kmalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
30 if (!dgm) {
31 pr_warn("Out of memory\n");
32 return NULL;
33 }
34 caif_assert(offsetof(struct cfsrvl, layer) == 0);
35 memset(dgm, 0, sizeof(struct cfsrvl));
36 cfsrvl_init(dgm, channel_id, dev_info, true);
37 dgm->layer.receive = cfdgml_receive;
38 dgm->layer.transmit = cfdgml_transmit;
39 snprintf(dgm->layer.name, CAIF_LAYER_NAME_SZ - 1, "dgm%d", channel_id);
40 dgm->layer.name[CAIF_LAYER_NAME_SZ - 1] = '\0';
41 return &dgm->layer;
42 }
43
cfdgml_receive(struct cflayer * layr,struct cfpkt * pkt)44 static int cfdgml_receive(struct cflayer *layr, struct cfpkt *pkt)
45 {
46 u8 cmd = -1;
47 u8 dgmhdr[3];
48 int ret;
49 caif_assert(layr->up != NULL);
50 caif_assert(layr->receive != NULL);
51 caif_assert(layr->ctrlcmd != NULL);
52
53 if (cfpkt_extr_head(pkt, &cmd, 1) < 0) {
54 pr_err("Packet is erroneous!\n");
55 cfpkt_destroy(pkt);
56 return -EPROTO;
57 }
58
59 if ((cmd & DGM_CMD_BIT) == 0) {
60 if (cfpkt_extr_head(pkt, &dgmhdr, 3) < 0) {
61 pr_err("Packet is erroneous!\n");
62 cfpkt_destroy(pkt);
63 return -EPROTO;
64 }
65 ret = layr->up->receive(layr->up, pkt);
66 return ret;
67 }
68
69 switch (cmd) {
70 case DGM_FLOW_OFF: /* FLOW OFF */
71 layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_OFF_IND, 0);
72 cfpkt_destroy(pkt);
73 return 0;
74 case DGM_FLOW_ON: /* FLOW ON */
75 layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_ON_IND, 0);
76 cfpkt_destroy(pkt);
77 return 0;
78 default:
79 cfpkt_destroy(pkt);
80 pr_info("Unknown datagram control %d (0x%x)\n", cmd, cmd);
81 return -EPROTO;
82 }
83 }
84
cfdgml_transmit(struct cflayer * layr,struct cfpkt * pkt)85 static int cfdgml_transmit(struct cflayer *layr, struct cfpkt *pkt)
86 {
87 u8 packet_type;
88 u32 zero = 0;
89 struct caif_payload_info *info;
90 struct cfsrvl *service = container_obj(layr);
91 int ret;
92 if (!cfsrvl_ready(service, &ret))
93 return ret;
94
95 /* STE Modem cannot handle more than 1500 bytes datagrams */
96 if (cfpkt_getlen(pkt) > DGM_MTU)
97 return -EMSGSIZE;
98
99 cfpkt_add_head(pkt, &zero, 3);
100 packet_type = 0x08; /* B9 set - UNCLASSIFIED */
101 cfpkt_add_head(pkt, &packet_type, 1);
102
103 /* Add info for MUX-layer to route the packet out. */
104 info = cfpkt_info(pkt);
105 info->channel_id = service->layer.id;
106 /* To optimize alignment, we add up the size of CAIF header
107 * before payload.
108 */
109 info->hdr_len = 4;
110 info->dev_info = &service->dev_info;
111 ret = layr->dn->transmit(layr->dn, pkt);
112 if (ret < 0) {
113 u32 tmp32;
114 cfpkt_extr_head(pkt, &tmp32, 4);
115 }
116 return ret;
117 }
118