1 /* 2 * Copyright (C) ST-Ericsson AB 2010 3 * Author: Sjur Brendeland 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 27 struct cflayer *cfdgml_create(u8 channel_id, struct dev_info *dev_info) 28 { 29 struct cfsrvl *dgm = kzalloc(sizeof(struct cfsrvl), GFP_ATOMIC); 30 if (!dgm) 31 return NULL; 32 caif_assert(offsetof(struct cfsrvl, layer) == 0); 33 cfsrvl_init(dgm, channel_id, dev_info, true); 34 dgm->layer.receive = cfdgml_receive; 35 dgm->layer.transmit = cfdgml_transmit; 36 snprintf(dgm->layer.name, CAIF_LAYER_NAME_SZ - 1, "dgm%d", channel_id); 37 dgm->layer.name[CAIF_LAYER_NAME_SZ - 1] = '\0'; 38 return &dgm->layer; 39 } 40 41 static int cfdgml_receive(struct cflayer *layr, struct cfpkt *pkt) 42 { 43 u8 cmd = -1; 44 u8 dgmhdr[3]; 45 int ret; 46 caif_assert(layr->up != NULL); 47 caif_assert(layr->receive != NULL); 48 caif_assert(layr->ctrlcmd != NULL); 49 50 if (cfpkt_extr_head(pkt, &cmd, 1) < 0) { 51 pr_err("Packet is erroneous!\n"); 52 cfpkt_destroy(pkt); 53 return -EPROTO; 54 } 55 56 if ((cmd & DGM_CMD_BIT) == 0) { 57 if (cfpkt_extr_head(pkt, &dgmhdr, 3) < 0) { 58 pr_err("Packet is erroneous!\n"); 59 cfpkt_destroy(pkt); 60 return -EPROTO; 61 } 62 ret = layr->up->receive(layr->up, pkt); 63 return ret; 64 } 65 66 switch (cmd) { 67 case DGM_FLOW_OFF: /* FLOW OFF */ 68 layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_OFF_IND, 0); 69 cfpkt_destroy(pkt); 70 return 0; 71 case DGM_FLOW_ON: /* FLOW ON */ 72 layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_ON_IND, 0); 73 cfpkt_destroy(pkt); 74 return 0; 75 default: 76 cfpkt_destroy(pkt); 77 pr_info("Unknown datagram control %d (0x%x)\n", cmd, cmd); 78 return -EPROTO; 79 } 80 } 81 82 static int cfdgml_transmit(struct cflayer *layr, struct cfpkt *pkt) 83 { 84 u8 packet_type; 85 u32 zero = 0; 86 struct caif_payload_info *info; 87 struct cfsrvl *service = container_obj(layr); 88 int ret; 89 90 if (!cfsrvl_ready(service, &ret)) { 91 cfpkt_destroy(pkt); 92 return ret; 93 } 94 95 /* STE Modem cannot handle more than 1500 bytes datagrams */ 96 if (cfpkt_getlen(pkt) > DGM_MTU) { 97 cfpkt_destroy(pkt); 98 return -EMSGSIZE; 99 } 100 101 cfpkt_add_head(pkt, &zero, 3); 102 packet_type = 0x08; /* B9 set - UNCLASSIFIED */ 103 cfpkt_add_head(pkt, &packet_type, 1); 104 105 /* Add info for MUX-layer to route the packet out. */ 106 info = cfpkt_info(pkt); 107 info->channel_id = service->layer.id; 108 /* To optimize alignment, we add up the size of CAIF header 109 * before payload. 110 */ 111 info->hdr_len = 4; 112 info->dev_info = &service->dev_info; 113 return layr->dn->transmit(layr->dn, pkt); 114 } 115