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/*
* Copyright (C) ST-Ericsson AB 2010
* Author: Sjur Brendeland/sjur.brandeland@stericsson.com
* License terms: GNU General Public License (GPL) version 2
*/
#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
#include <linux/stddef.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <net/caif/caif_layer.h>
#include <net/caif/cfsrvl.h>
#include <net/caif/cfpkt.h>
#define container_obj(layr) ((struct cfsrvl *) layr)
#define DGM_CMD_BIT 0x80
#define DGM_FLOW_OFF 0x81
#define DGM_FLOW_ON 0x80
#define DGM_CTRL_PKT_SIZE 1
#define DGM_MTU 1500
static int cfdgml_receive(struct cflayer *layr, struct cfpkt *pkt);
static int cfdgml_transmit(struct cflayer *layr, struct cfpkt *pkt);
struct cflayer *cfdgml_create(u8 channel_id, struct dev_info *dev_info)
{
struct cfsrvl *dgm = kmalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
if (!dgm) {
pr_warn("Out of memory\n");
return NULL;
}
caif_assert(offsetof(struct cfsrvl, layer) == 0);
memset(dgm, 0, sizeof(struct cfsrvl));
cfsrvl_init(dgm, channel_id, dev_info, true);
dgm->layer.receive = cfdgml_receive;
dgm->layer.transmit = cfdgml_transmit;
snprintf(dgm->layer.name, CAIF_LAYER_NAME_SZ - 1, "dgm%d", channel_id);
dgm->layer.name[CAIF_LAYER_NAME_SZ - 1] = '\0';
return &dgm->layer;
}
static int cfdgml_receive(struct cflayer *layr, struct cfpkt *pkt)
{
u8 cmd = -1;
u8 dgmhdr[3];
int ret;
caif_assert(layr->up != NULL);
caif_assert(layr->receive != NULL);
caif_assert(layr->ctrlcmd != NULL);
if (cfpkt_extr_head(pkt, &cmd, 1) < 0) {
pr_err("Packet is erroneous!\n");
cfpkt_destroy(pkt);
return -EPROTO;
}
if ((cmd & DGM_CMD_BIT) == 0) {
if (cfpkt_extr_head(pkt, &dgmhdr, 3) < 0) {
pr_err("Packet is erroneous!\n");
cfpkt_destroy(pkt);
return -EPROTO;
}
ret = layr->up->receive(layr->up, pkt);
return ret;
}
switch (cmd) {
case DGM_FLOW_OFF: /* FLOW OFF */
layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_OFF_IND, 0);
cfpkt_destroy(pkt);
return 0;
case DGM_FLOW_ON: /* FLOW ON */
layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_ON_IND, 0);
cfpkt_destroy(pkt);
return 0;
default:
cfpkt_destroy(pkt);
pr_info("Unknown datagram control %d (0x%x)\n", cmd, cmd);
return -EPROTO;
}
}
static int cfdgml_transmit(struct cflayer *layr, struct cfpkt *pkt)
{
u32 zero = 0;
struct caif_payload_info *info;
struct cfsrvl *service = container_obj(layr);
int ret;
if (!cfsrvl_ready(service, &ret))
return ret;
/* STE Modem cannot handle more than 1500 bytes datagrams */
if (cfpkt_getlen(pkt) > DGM_MTU)
return -EMSGSIZE;
cfpkt_add_head(pkt, &zero, 4);
/* Add info for MUX-layer to route the packet out. */
info = cfpkt_info(pkt);
info->channel_id = service->layer.id;
/* To optimize alignment, we add up the size of CAIF header
* before payload.
*/
info->hdr_len = 4;
info->dev_info = &service->dev_info;
ret = layr->dn->transmit(layr->dn, pkt);
if (ret < 0) {
u32 tmp32;
cfpkt_extr_head(pkt, &tmp32, 4);
}
return ret;
}
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