--- /dev/null
+/*
+ * 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);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff