linux/net/caif/cfdgml.c
<<
>>
Prefs
   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
  24static int cfdgml_receive(struct cflayer *layr, struct cfpkt *pkt);
  25static int cfdgml_transmit(struct cflayer *layr, struct cfpkt *pkt);
  26
  27struct 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
  44static 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
  85static 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