1 files changed, 374 insertions, 0 deletions

diff --git a/drivers/uwb/wlp/txrx.c b/drivers/uwb/wlp/txrx.c
new file mode 100644
index 000000000000..c701bd1a2887
--- /dev/null
+++ b/drivers/uwb/wlp/txrx.c
@@ -0,0 +1,374 @@
+/*
+ * WiMedia Logical Link Control Protocol (WLP)
+ * Message exchange infrastructure
+ *
+ * Copyright (C) 2007 Intel Corporation
+ * Reinette Chatre <reinette.chatre@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ *
+ * FIXME: Docs
+ *
+ */
+
+#include <linux/etherdevice.h>
+#include <linux/wlp.h>
+#define D_LOCAL 5
+#include <linux/uwb/debug.h>
+#include "wlp-internal.h"
+
+
+/**
+ * Direct incoming association msg to correct parsing routine
+ *
+ * We only expect D1, E1, C1, C3 messages as new. All other incoming
+ * association messages should form part of an established session that is
+ * handled elsewhere.
+ * The handling of these messages often require calling sleeping functions
+ * - this cannot be done in interrupt context. We use the kernel's
+ * workqueue to handle these messages.
+ */
+static
+void wlp_direct_assoc_frame(struct wlp *wlp, struct sk_buff *skb,
+                           struct uwb_dev_addr *src)
+{
+        struct device *dev = &wlp->rc->uwb_dev.dev;
+        struct wlp_frame_assoc *assoc = (void *) skb->data;
+        struct wlp_assoc_frame_ctx *frame_ctx;
+        d_fnstart(5, dev, "wlp %p, skb %p\n", wlp, skb);
+        frame_ctx = kmalloc(sizeof(*frame_ctx), GFP_ATOMIC);
+        if (frame_ctx == NULL) {
+                dev_err(dev, "WLP: Unable to allocate memory for association "
+                        "frame handling.\n");
+                kfree_skb(skb);
+                goto out;
+        }
+        frame_ctx->wlp = wlp;
+        frame_ctx->skb = skb;
+        frame_ctx->src = *src;
+        switch (assoc->type) {
+        case WLP_ASSOC_D1:
+                d_printf(5, dev, "Received a D1 frame.\n");
+                INIT_WORK(&frame_ctx->ws, wlp_handle_d1_frame);
+                schedule_work(&frame_ctx->ws);
+                break;
+        case WLP_ASSOC_E1:
+                d_printf(5, dev, "Received a E1 frame. FIXME?\n");
+                kfree_skb(skb); /* Temporary until we handle it */
+                kfree(frame_ctx); /* Temporary until we handle it */
+                break;
+        case WLP_ASSOC_C1:
+                d_printf(5, dev, "Received a C1 frame.\n");
+                INIT_WORK(&frame_ctx->ws, wlp_handle_c1_frame);
+                schedule_work(&frame_ctx->ws);
+                break;
+        case WLP_ASSOC_C3:
+                d_printf(5, dev, "Received a C3 frame.\n");
+                INIT_WORK(&frame_ctx->ws, wlp_handle_c3_frame);
+                schedule_work(&frame_ctx->ws);
+                break;
+        default:
+                dev_err(dev, "Received unexpected association frame. "
+                        "Type = %d \n", assoc->type);
+                kfree_skb(skb);
+                kfree(frame_ctx);
+                break;
+        }
+out:
+        d_fnend(5, dev, "wlp %p\n", wlp);
+}
+
+/**
+ * Process incoming association frame
+ *
+ * Although it could be possible to deal with some incoming association
+ * messages without creating a new session we are keeping things simple. We
+ * do not accept new association messages if there is a session in progress
+ * and the messages do not belong to that session.
+ *
+ * If an association message arrives that causes the creation of a session
+ * (WLP_ASSOC_E1) while we are in the process of creating a session then we
+ * rely on the neighbor mutex to protect the data. That is, the new session
+ * will not be started until the previous is completed.
+ */
+static
+void wlp_receive_assoc_frame(struct wlp *wlp, struct sk_buff *skb,
+                             struct uwb_dev_addr *src)
+{
+        struct device *dev = &wlp->rc->uwb_dev.dev;
+        struct wlp_frame_assoc *assoc = (void *) skb->data;
+        struct wlp_session *session = wlp->session;
+        u8 version;
+        d_fnstart(5, dev, "wlp %p, skb %p\n", wlp, skb);
+
+        if (wlp_get_version(wlp, &assoc->version, &version,
+                            sizeof(assoc->version)) < 0)
+                goto error;
+        if (version != WLP_VERSION) {
+                dev_err(dev, "Unsupported WLP version in association "
+                        "message.\n");
+                goto error;
+        }
+        if (session != NULL) {
+                /* Function that created this session is still holding the
+                 * &wlp->mutex to protect this session. */
+                if (assoc->type == session->exp_message ||
+                    assoc->type == WLP_ASSOC_F0) {
+                        if (!memcmp(&session->neighbor_addr, src,
+                                   sizeof(*src))) {
+                                session->data = skb;
+                                (session->cb)(wlp);
+                        } else {
+                                dev_err(dev, "Received expected message from "
+                                        "unexpected source.  Expected message "
+                                        "%d or F0 from %02x:%02x, but received "
+                                        "it from %02x:%02x. Dropping.\n",
+                                        session->exp_message,
+                                        session->neighbor_addr.data[1],
+                                        session->neighbor_addr.data[0],
+                                        src->data[1], src->data[0]);
+                                goto error;
+                        }
+                } else {
+                        dev_err(dev, "Association already in progress. "
+                                "Dropping.\n");
+                        goto error;
+                }
+        } else {
+                wlp_direct_assoc_frame(wlp, skb, src);
+        }
+        d_fnend(5, dev, "wlp %p\n", wlp);
+        return;
+error:
+        kfree_skb(skb);
+        d_fnend(5, dev, "wlp %p\n", wlp);
+}
+
+/**
+ * Verify incoming frame is from connected neighbor, prep to pass to WLP client
+ *
+ * Verification proceeds according to WLP 0.99 [7.3.1]. The source address
+ * is used to determine which neighbor is sending the frame and the WSS tag
+ * is used to know to which WSS the frame belongs (we only support one WSS
+ * so this test is straight forward).
+ * With the WSS found we need to ensure that we are connected before
+ * allowing the exchange of data frames.
+ */
+static
+int wlp_verify_prep_rx_frame(struct wlp *wlp, struct sk_buff *skb,
+                             struct uwb_dev_addr *src)
+{
+        struct device *dev = &wlp->rc->uwb_dev.dev;
+        int result = -EINVAL;
+        struct wlp_eda_node eda_entry;
+        struct wlp_frame_std_abbrv_hdr *hdr = (void *) skb->data;
+
+        d_fnstart(6, dev, "wlp %p, skb %p \n", wlp, skb);
+        /*verify*/
+        result = wlp_copy_eda_node(&wlp->eda, src, &eda_entry);
+        if (result < 0) {
+                if (printk_ratelimit())
+                        dev_err(dev, "WLP: Incoming frame is from unknown "
+                                "neighbor %02x:%02x.\n", src->data[1],
+                                src->data[0]);
+                goto out;
+        }
+        if (hdr->tag != eda_entry.tag) {
+                if (printk_ratelimit())
+                        dev_err(dev, "WLP: Tag of incoming frame from "
+                                "%02x:%02x does not match expected tag. "
+                                "Received 0x%02x, expected 0x%02x. \n",
+                                src->data[1], src->data[0], hdr->tag,
+                                eda_entry.tag);
+                result = -EINVAL;
+                goto out;
+        }
+        if (eda_entry.state != WLP_WSS_CONNECTED) {
+                if (printk_ratelimit())
+                        dev_err(dev, "WLP: Incoming frame from "
+                                "%02x:%02x does is not from connected WSS.\n",
+                                src->data[1], src->data[0]);
+                result = -EINVAL;
+                goto out;
+        }
+        /*prep*/
+        skb_pull(skb, sizeof(*hdr));
+out:
+        d_fnend(6, dev, "wlp %p, skb %p, result = %d \n", wlp, skb, result);
+        return result;
+}
+
+/**
+ * Receive a WLP frame from device
+ *
+ * @returns: 1 if calling function should free the skb
+ *           0 if it successfully handled skb and freed it
+ *           0 if error occured, will free skb in this case
+ */
+int wlp_receive_frame(struct device *dev, struct wlp *wlp, struct sk_buff *skb,
+                      struct uwb_dev_addr *src)
+{
+        unsigned len = skb->len;
+        void *ptr = skb->data;
+        struct wlp_frame_hdr *hdr;
+        int result = 0;
+
+        d_fnstart(6, dev, "skb (%p), len (%u)\n", skb, len);
+        if (len < sizeof(*hdr)) {
+                dev_err(dev, "Not enough data to parse WLP header.\n");
+                result = -EINVAL;
+                goto out;
+        }
+        hdr = ptr;
+        d_dump(6, dev, hdr, sizeof(*hdr));
+        if (le16_to_cpu(hdr->mux_hdr) != WLP_PROTOCOL_ID) {
+                dev_err(dev, "Not a WLP frame type.\n");
+                result = -EINVAL;
+                goto out;
+        }
+        switch (hdr->type) {
+        case WLP_FRAME_STANDARD:
+                if (len < sizeof(struct wlp_frame_std_abbrv_hdr)) {
+                        dev_err(dev, "Not enough data to parse Standard "
+                                "WLP header.\n");
+                        goto out;
+                }
+                result = wlp_verify_prep_rx_frame(wlp, skb, src);
+                if (result < 0) {
+                        if (printk_ratelimit())
+                                dev_err(dev, "WLP: Verification of frame "
+                                        "from neighbor %02x:%02x failed.\n",
+                                        src->data[1], src->data[0]);
+                        goto out;
+                }
+                result = 1;
+                break;
+        case WLP_FRAME_ABBREVIATED:
+                dev_err(dev, "Abbreviated frame received. FIXME?\n");
+                kfree_skb(skb);
+                break;
+        case WLP_FRAME_CONTROL:
+                dev_err(dev, "Control frame received. FIXME?\n");
+                kfree_skb(skb);
+                break;
+        case WLP_FRAME_ASSOCIATION:
+                if (len < sizeof(struct wlp_frame_assoc)) {
+                        dev_err(dev, "Not enough data to parse Association "
+                                "WLP header.\n");
+                        goto out;
+                }
+                d_printf(5, dev, "Association frame received.\n");
+                wlp_receive_assoc_frame(wlp, skb, src);
+                break;
+        default:
+                dev_err(dev, "Invalid frame received.\n");
+                result = -EINVAL;
+                break;
+        }
+out:
+        if (result < 0) {
+                kfree_skb(skb);
+                result = 0;
+        }
+        d_fnend(6, dev, "skb (%p)\n", skb);
+        return result;
+}
+EXPORT_SYMBOL_GPL(wlp_receive_frame);
+
+
+/**
+ * Verify frame from network stack, prepare for further transmission
+ *
+ * @skb:   the socket buffer that needs to be prepared for transmission (it
+ *         is in need of a WLP header). If this is a broadcast frame we take
+ *         over the entire transmission.
+ *         If it is a unicast the WSS connection should already be established
+ *         and transmission will be done by the calling function.
+ * @dst:   On return this will contain the device address to which the
+ *         frame is destined.
+ * @returns: 0 on success no tx : WLP header sucessfully applied to skb buffer,
+ *                                calling function can proceed with tx
+ *           1 on success with tx : WLP will take over transmission of this
+ *                                  frame
+ *           <0 on error
+ *
+ * The network stack (WLP client) is attempting to transmit a frame. We can
+ * only transmit data if a local WSS is at least active (connection will be
+ * done here if this is a broadcast frame and neighbor also has the WSS
+ * active).
+ *
+ * The frame can be either broadcast or unicast. Broadcast in a WSS is
+ * supported via multicast, but we don't support multicast yet (until
+ * devices start to support MAB IEs). If a broadcast frame needs to be
+ * transmitted it is treated as a unicast frame to each neighbor. In this
+ * case the WLP takes over transmission of the skb and returns 1
+ * to the caller to indicate so. Also, in this case, if a neighbor has the
+ * same WSS activated but is not connected then the WSS connection will be
+ * done at this time. The neighbor's virtual address will be learned at
+ * this time.
+ *
+ * The destination address in a unicast frame is the virtual address of the
+ * neighbor. This address only becomes known when a WSS connection is
+ * established. We thus rely on a broadcast frame to trigger the setup of
+ * WSS connections to all neighbors before we are able to send unicast
+ * frames to them. This seems reasonable as IP would usually use ARP first
+ * before any unicast frames are sent.
+ *
+ * If we are already connected to the neighbor (neighbor's virtual address
+ * is known) we just prepare the WLP header and the caller will continue to
+ * send the frame.
+ *
+ * A failure in this function usually indicates something that cannot be
+ * fixed automatically. So, if this function fails (@return < 0) the calling
+ * function should not retry to send the frame as it will very likely keep
+ * failing.
+ *
+ */
+int wlp_prepare_tx_frame(struct device *dev, struct wlp *wlp,
+                         struct sk_buff *skb, struct uwb_dev_addr *dst)
+{
+        int result = -EINVAL;
+        struct ethhdr *eth_hdr = (void *) skb->data;
+
+        d_fnstart(6, dev, "wlp (%p), skb (%p) \n", wlp, skb);
+        if (is_broadcast_ether_addr(eth_hdr->h_dest)) {
+                d_printf(6, dev, "WLP: handling broadcast frame. \n");
+                result = wlp_eda_for_each(&wlp->eda, wlp_wss_send_copy, skb);
+                if (result < 0) {
+                        if (printk_ratelimit())
+                                dev_err(dev, "Unable to handle broadcast "
+                                        "frame from WLP client.\n");
+                        goto out;
+                }
+                dev_kfree_skb_irq(skb);
+                result = 1;
+                /* Frame will be transmitted by WLP. */
+        } else {
+                d_printf(6, dev, "WLP: handling unicast frame. \n");
+                result = wlp_eda_for_virtual(&wlp->eda, eth_hdr->h_dest, dst,
+                                             wlp_wss_prep_hdr, skb);
+                if (unlikely(result < 0)) {
+                        if (printk_ratelimit())
+                                dev_err(dev, "Unable to prepare "
+                                        "skb for transmission. \n");
+                        goto out;
+                }
+        }
+out:
+        d_fnend(6, dev, "wlp (%p), skb (%p). result = %d \n", wlp, skb, result);
+        return result;
+}
+EXPORT_SYMBOL_GPL(wlp_prepare_tx_frame);