1 files changed, 113 insertions, 0 deletions
diff --git a/net/caif/cfdgml.c b/net/caif/cfdgml.c
new file mode 100644
index 000000000..eb6f8ef47
--- /dev/null
+++ b/net/caif/cfdgml.c
@@ -0,0 +1,113 @@
+// 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);
+}