Merge git://git.infradead.org/users/dwmw2/libraid-2.6 into for-linus
[cascardo/linux.git] / net / caif / cfrfml.c
index fd27b17..eb16020 100644 (file)
 #include <linux/stddef.h>
 #include <linux/spinlock.h>
 #include <linux/slab.h>
+#include <linux/unaligned/le_byteshift.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 cfsrvl, layer)
-
+#define container_obj(layr) container_of(layr, struct cfrfml, serv.layer)
 #define RFM_SEGMENTATION_BIT 0x01
-#define RFM_PAYLOAD  0x00
-#define RFM_CMD_BIT  0x80
-#define RFM_FLOW_OFF 0x81
-#define RFM_FLOW_ON  0x80
-#define RFM_SET_PIN  0x82
-#define RFM_CTRL_PKT_SIZE 1
+#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);
-static int cfservl_modemcmd(struct cflayer *layr, enum caif_modemcmd ctrl);
 
-struct cflayer *cfrfml_create(u8 channel_id, struct dev_info *dev_info)
+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 kref *kref)
+{
+       struct cfsrvl *srvl = container_of(kref, struct cfsrvl, ref);
+       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)
 {
-       struct cfsrvl *rfm = kmalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
-       if (!rfm) {
+       int tmp;
+       struct cfrfml *this =
+               kzalloc(sizeof(struct cfrfml), GFP_ATOMIC);
+
+       if (!this) {
                pr_warning("CAIF: %s(): Out of memory\n", __func__);
                return NULL;
        }
-       caif_assert(offsetof(struct cfsrvl, layer) == 0);
-       memset(rfm, 0, sizeof(struct cfsrvl));
-       cfsrvl_init(rfm, channel_id, dev_info);
-       rfm->layer.modemcmd = cfservl_modemcmd;
-       rfm->layer.receive = cfrfml_receive;
-       rfm->layer.transmit = cfrfml_transmit;
-       snprintf(rfm->layer.name, CAIF_LAYER_NAME_SZ, "rfm%d", channel_id);
-       return &rfm->layer;
+
+       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 int cfservl_modemcmd(struct cflayer *layr, enum caif_modemcmd ctrl)
+static struct cfpkt *rfm_append(struct cfrfml *rfml, char *seghead,
+                       struct cfpkt *pkt, int *err)
 {
-       return -EPROTO;
+       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 ret;
+       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("CAIF: %s(): "
+                               "Connection error %d triggered on RFM link\n",
+                               __func__, 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);
+       return err;
+}
+
+
+static int cfrfml_transmit_segment(struct cfrfml *rfml, struct cfpkt *pkt)
+{
+       caif_assert(cfpkt_getlen(pkt) >= rfml->fragment_size);
+
+       /* Add info for MUX-layer to route the packet out. */
+       cfpkt_info(pkt)->channel_id = rfml->serv.layer.id;
 
        /*
-        * RFM is taking care of segmentation and stripping of
-        * segmentation bit.
+        * To optimize alignment, we add up the size of CAIF header before
+        * payload.
         */
-       if (cfpkt_extr_head(pkt, &tmp, 1) < 0) {
-               pr_err("CAIF: %s(): Packet is erroneous!\n", __func__);
-               cfpkt_destroy(pkt);
-               return -EPROTO;
-       }
-       segmented = tmp & RFM_SEGMENTATION_BIT;
-       caif_assert(!segmented);
+       cfpkt_info(pkt)->hdr_len = RFM_HEAD_SIZE;
+       cfpkt_info(pkt)->dev_info = &rfml->serv.dev_info;
 
-       ret = layr->up->receive(layr->up, pkt);
-       return ret;
+       return rfml->serv.layer.dn->transmit(rfml->serv.layer.dn, pkt);
 }
 
 static int cfrfml_transmit(struct cflayer *layr, struct cfpkt *pkt)
 {
-       u8 tmp = 0;
-       int ret;
-       struct cfsrvl *service = container_obj(layr);
+       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(service, &ret))
-               return ret;
+       if (!cfsrvl_ready(&rfml->serv, &err))
+               return err;
+
+       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)
+                       goto out;
+               frontpkt = rearpkt;
+               rearpkt = NULL;
+
+               err = -ENOMEM;
+               if (frontpkt == NULL)
+                       goto out;
+               err = -EPROTO;
+               if (cfpkt_add_head(frontpkt, head, 6) < 0)
+                       goto out;
 
-       if (cfpkt_getlen(pkt) > CAIF_MAX_PAYLOAD_SIZE) {
-               pr_err("CAIF: %s():Packet too large - size=%d\n",
-                       __func__, cfpkt_getlen(pkt));
-               return -EOVERFLOW;
        }
-       if (cfpkt_add_head(pkt, &tmp, 1) < 0) {
-               pr_err("CAIF: %s(): Packet is erroneous!\n", __func__);
-               return -EPROTO;
+
+       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("CAIF: %s(): "
+                               "Connection error %d triggered on RFM link\n",
+                               __func__, 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 && frontpkt != pkt) {
+
+                       cfpkt_destroy(frontpkt);
+                       /*
+                        * Socket layer will free the original packet,
+                        * but this packet may already be sent and
+                        * freed. So we have to return 0 in this case
+                        * to avoid socket layer to re-free this packet.
+                        * The return of shutdown indication will
+                        * cause connection to be invalidated anyhow.
+                        */
+                       err = 0;
+               }
        }
 
-       /* Add info for MUX-layer to route the packet out. */
-       cfpkt_info(pkt)->channel_id = service->layer.id;
-       /*
-        * To optimize alignment, we add up the size of CAIF header before
-        * payload.
-        */
-       cfpkt_info(pkt)->hdr_len = 1;
-       cfpkt_info(pkt)->dev_info = &service->dev_info;
-       ret = layr->dn->transmit(layr->dn, pkt);
-       if (ret < 0)
-               cfpkt_extr_head(pkt, &tmp, 1);
-       return ret;
+       return err;
 }