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-rw-r--r--net/caif/cfrfml.c299
1 files changed, 299 insertions, 0 deletions
diff --git a/net/caif/cfrfml.c b/net/caif/cfrfml.c
new file mode 100644
index 000000000..7b0af33bd
--- /dev/null
+++ b/net/caif/cfrfml.c
@@ -0,0 +1,299 @@
+// 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 <asm/unaligned.h>
+#include <net/caif/caif_layer.h>
+#include <net/caif/cfsrvl.h>
+#include <net/caif/cfpkt.h>
+
+#define container_obj(layr) container_of(layr, struct cfrfml, serv.layer)
+#define RFM_SEGMENTATION_BIT 0x01
+#define RFM_HEAD_SIZE 7
+
+static int cfrfml_receive(struct cflayer *layr, struct cfpkt *pkt);
+static int cfrfml_transmit(struct cflayer *layr, struct cfpkt *pkt);
+
+struct cfrfml {
+ struct cfsrvl serv;
+ struct cfpkt *incomplete_frm;
+ int fragment_size;
+ u8 seghead[6];
+ u16 pdu_size;
+ /* Protects serialized processing of packets */
+ spinlock_t sync;
+};
+
+static void cfrfml_release(struct cflayer *layer)
+{
+ struct cfsrvl *srvl = container_of(layer, struct cfsrvl, layer);
+ struct cfrfml *rfml = container_obj(&srvl->layer);
+
+ if (rfml->incomplete_frm)
+ cfpkt_destroy(rfml->incomplete_frm);
+
+ kfree(srvl);
+}
+
+struct cflayer *cfrfml_create(u8 channel_id, struct dev_info *dev_info,
+ int mtu_size)
+{
+ int tmp;
+ struct cfrfml *this = kzalloc(sizeof(struct cfrfml), GFP_ATOMIC);
+
+ if (!this)
+ return NULL;
+
+ cfsrvl_init(&this->serv, channel_id, dev_info, false);
+ this->serv.release = cfrfml_release;
+ this->serv.layer.receive = cfrfml_receive;
+ this->serv.layer.transmit = cfrfml_transmit;
+
+ /* Round down to closest multiple of 16 */
+ tmp = (mtu_size - RFM_HEAD_SIZE - 6) / 16;
+ tmp *= 16;
+
+ this->fragment_size = tmp;
+ spin_lock_init(&this->sync);
+ snprintf(this->serv.layer.name, CAIF_LAYER_NAME_SZ,
+ "rfm%d", channel_id);
+
+ return &this->serv.layer;
+}
+
+static struct cfpkt *rfm_append(struct cfrfml *rfml, char *seghead,
+ struct cfpkt *pkt, int *err)
+{
+ struct cfpkt *tmppkt;
+ *err = -EPROTO;
+ /* n-th but not last segment */
+
+ if (cfpkt_extr_head(pkt, seghead, 6) < 0)
+ return NULL;
+
+ /* Verify correct header */
+ if (memcmp(seghead, rfml->seghead, 6) != 0)
+ return NULL;
+
+ tmppkt = cfpkt_append(rfml->incomplete_frm, pkt,
+ rfml->pdu_size + RFM_HEAD_SIZE);
+
+ /* If cfpkt_append failes input pkts are not freed */
+ *err = -ENOMEM;
+ if (tmppkt == NULL)
+ return NULL;
+
+ *err = 0;
+ return tmppkt;
+}
+
+static int cfrfml_receive(struct cflayer *layr, struct cfpkt *pkt)
+{
+ u8 tmp;
+ bool segmented;
+ int err;
+ u8 seghead[6];
+ struct cfrfml *rfml;
+ struct cfpkt *tmppkt = NULL;
+
+ caif_assert(layr->up != NULL);
+ caif_assert(layr->receive != NULL);
+ rfml = container_obj(layr);
+ spin_lock(&rfml->sync);
+
+ err = -EPROTO;
+ if (cfpkt_extr_head(pkt, &tmp, 1) < 0)
+ goto out;
+ segmented = tmp & RFM_SEGMENTATION_BIT;
+
+ if (segmented) {
+ if (rfml->incomplete_frm == NULL) {
+ /* Initial Segment */
+ if (cfpkt_peek_head(pkt, rfml->seghead, 6) != 0)
+ goto out;
+
+ rfml->pdu_size = get_unaligned_le16(rfml->seghead+4);
+
+ if (cfpkt_erroneous(pkt))
+ goto out;
+ rfml->incomplete_frm = pkt;
+ pkt = NULL;
+ } else {
+
+ tmppkt = rfm_append(rfml, seghead, pkt, &err);
+ if (tmppkt == NULL)
+ goto out;
+
+ if (cfpkt_erroneous(tmppkt))
+ goto out;
+
+ rfml->incomplete_frm = tmppkt;
+
+
+ if (cfpkt_erroneous(tmppkt))
+ goto out;
+ }
+ err = 0;
+ goto out;
+ }
+
+ if (rfml->incomplete_frm) {
+
+ /* Last Segment */
+ tmppkt = rfm_append(rfml, seghead, pkt, &err);
+ if (tmppkt == NULL)
+ goto out;
+
+ if (cfpkt_erroneous(tmppkt))
+ goto out;
+
+ rfml->incomplete_frm = NULL;
+ pkt = tmppkt;
+ tmppkt = NULL;
+
+ /* Verify that length is correct */
+ err = -EPROTO;
+ if (rfml->pdu_size != cfpkt_getlen(pkt) - RFM_HEAD_SIZE + 1)
+ goto out;
+ }
+
+ err = rfml->serv.layer.up->receive(rfml->serv.layer.up, pkt);
+
+out:
+
+ if (err != 0) {
+ if (tmppkt)
+ cfpkt_destroy(tmppkt);
+ if (pkt)
+ cfpkt_destroy(pkt);
+ if (rfml->incomplete_frm)
+ cfpkt_destroy(rfml->incomplete_frm);
+ rfml->incomplete_frm = NULL;
+
+ pr_info("Connection error %d triggered on RFM link\n", err);
+
+ /* Trigger connection error upon failure.*/
+ layr->up->ctrlcmd(layr->up, CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND,
+ rfml->serv.dev_info.id);
+ }
+ spin_unlock(&rfml->sync);
+
+ if (unlikely(err == -EAGAIN))
+ /* It is not possible to recover after drop of a fragment */
+ err = -EIO;
+
+ return err;
+}
+
+
+static int cfrfml_transmit_segment(struct cfrfml *rfml, struct cfpkt *pkt)
+{
+ caif_assert(cfpkt_getlen(pkt) < rfml->fragment_size + RFM_HEAD_SIZE);
+
+ /* Add info for MUX-layer to route the packet out. */
+ cfpkt_info(pkt)->channel_id = rfml->serv.layer.id;
+
+ /*
+ * To optimize alignment, we add up the size of CAIF header before
+ * payload.
+ */
+ cfpkt_info(pkt)->hdr_len = RFM_HEAD_SIZE;
+ cfpkt_info(pkt)->dev_info = &rfml->serv.dev_info;
+
+ return rfml->serv.layer.dn->transmit(rfml->serv.layer.dn, pkt);
+}
+
+static int cfrfml_transmit(struct cflayer *layr, struct cfpkt *pkt)
+{
+ int err;
+ u8 seg;
+ u8 head[6];
+ struct cfpkt *rearpkt = NULL;
+ struct cfpkt *frontpkt = pkt;
+ struct cfrfml *rfml = container_obj(layr);
+
+ caif_assert(layr->dn != NULL);
+ caif_assert(layr->dn->transmit != NULL);
+
+ if (!cfsrvl_ready(&rfml->serv, &err))
+ goto out;
+
+ err = -EPROTO;
+ if (cfpkt_getlen(pkt) <= RFM_HEAD_SIZE-1)
+ goto out;
+
+ err = 0;
+ if (cfpkt_getlen(pkt) > rfml->fragment_size + RFM_HEAD_SIZE)
+ err = cfpkt_peek_head(pkt, head, 6);
+
+ if (err != 0)
+ goto out;
+
+ while (cfpkt_getlen(frontpkt) > rfml->fragment_size + RFM_HEAD_SIZE) {
+
+ seg = 1;
+ err = -EPROTO;
+
+ if (cfpkt_add_head(frontpkt, &seg, 1) < 0)
+ goto out;
+ /*
+ * On OOM error cfpkt_split returns NULL.
+ *
+ * NOTE: Segmented pdu is not correctly aligned.
+ * This has negative performance impact.
+ */
+
+ rearpkt = cfpkt_split(frontpkt, rfml->fragment_size);
+ if (rearpkt == NULL)
+ goto out;
+
+ err = cfrfml_transmit_segment(rfml, frontpkt);
+
+ if (err != 0) {
+ frontpkt = NULL;
+ goto out;
+ }
+
+ frontpkt = rearpkt;
+ rearpkt = NULL;
+
+ err = -EPROTO;
+ if (cfpkt_add_head(frontpkt, head, 6) < 0)
+ goto out;
+
+ }
+
+ seg = 0;
+ err = -EPROTO;
+
+ if (cfpkt_add_head(frontpkt, &seg, 1) < 0)
+ goto out;
+
+ err = cfrfml_transmit_segment(rfml, frontpkt);
+
+ frontpkt = NULL;
+out:
+
+ if (err != 0) {
+ pr_info("Connection error %d triggered on RFM link\n", err);
+ /* Trigger connection error upon failure.*/
+
+ layr->up->ctrlcmd(layr->up, CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND,
+ rfml->serv.dev_info.id);
+
+ if (rearpkt)
+ cfpkt_destroy(rearpkt);
+
+ if (frontpkt)
+ cfpkt_destroy(frontpkt);
+ }
+
+ return err;
+}
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