| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Copyright (C) ST-Ericsson AB 2010 |
| * Author: Sjur Brendeland |
| */ |
| |
| #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_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 = kzalloc(sizeof(struct cfsrvl), GFP_ATOMIC); |
| if (!dgm) |
| return NULL; |
| caif_assert(offsetof(struct cfsrvl, layer) == 0); |
| 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, "dgm%d", channel_id); |
| 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) |
| { |
| u8 packet_type; |
| u32 zero = 0; |
| struct caif_payload_info *info; |
| struct cfsrvl *service = container_obj(layr); |
| int ret; |
| |
| if (!cfsrvl_ready(service, &ret)) { |
| cfpkt_destroy(pkt); |
| return ret; |
| } |
| |
| /* STE Modem cannot handle more than 1500 bytes datagrams */ |
| if (cfpkt_getlen(pkt) > DGM_MTU) { |
| cfpkt_destroy(pkt); |
| return -EMSGSIZE; |
| } |
| |
| cfpkt_add_head(pkt, &zero, 3); |
| packet_type = 0x08; /* B9 set - UNCLASSIFIED */ |
| cfpkt_add_head(pkt, &packet_type, 1); |
| |
| /* 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; |
| return layr->dn->transmit(layr->dn, pkt); |
| } |