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 #define container_obj(layr) ((struct cfsrvl *) layr) 17 18 #define DGM_CMD_BIT 0x80 19 #define DGM_FLOW_OFF 0x81 20 #define DGM_FLOW_ON 0x80 21 #define DGM_CTRL_PKT_SIZE 1 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 = 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 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 85 static int cfdgml_transmit(struct cflayer *layr, struct cfpkt *pkt) 86 { 87 u32 zero = 0; 88 struct caif_payload_info *info; 89 struct cfsrvl *service = container_obj(layr); 90 int ret; 91 if (!cfsrvl_ready(service, &ret)) 92 return ret; 93 94 /* STE Modem cannot handle more than 1500 bytes datagrams */ 95 if (cfpkt_getlen(pkt) > DGM_MTU) 96 return -EMSGSIZE; 97 98 cfpkt_add_head(pkt, &zero, 4); 99 100 /* Add info for MUX-layer to route the packet out. */ 101 info = cfpkt_info(pkt); 102 info->channel_id = service->layer.id; 103 /* To optimize alignment, we add up the size of CAIF header 104 * before payload. 105 */ 106 info->hdr_len = 4; 107 info->dev_info = &service->dev_info; 108 ret = layr->dn->transmit(layr->dn, pkt); 109 if (ret < 0) { 110 u32 tmp32; 111 cfpkt_extr_head(pkt, &tmp32, 4); 112 } 113 return ret; 114 } 115