354 lines
11 KiB
C
354 lines
11 KiB
C
/*
|
|
* 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>
|
|
|
|
#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;
|
|
|
|
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);
|
|
return;
|
|
}
|
|
frame_ctx->wlp = wlp;
|
|
frame_ctx->skb = skb;
|
|
frame_ctx->src = *src;
|
|
switch (assoc->type) {
|
|
case WLP_ASSOC_D1:
|
|
INIT_WORK(&frame_ctx->ws, wlp_handle_d1_frame);
|
|
schedule_work(&frame_ctx->ws);
|
|
break;
|
|
case WLP_ASSOC_E1:
|
|
kfree_skb(skb); /* Temporary until we handle it */
|
|
kfree(frame_ctx); /* Temporary until we handle it */
|
|
break;
|
|
case WLP_ASSOC_C1:
|
|
INIT_WORK(&frame_ctx->ws, wlp_handle_c1_frame);
|
|
schedule_work(&frame_ctx->ws);
|
|
break;
|
|
case WLP_ASSOC_C3:
|
|
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;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
|
|
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);
|
|
}
|
|
return;
|
|
error:
|
|
kfree_skb(skb);
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
|
|
/*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:
|
|
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;
|
|
|
|
if (len < sizeof(*hdr)) {
|
|
dev_err(dev, "Not enough data to parse WLP header.\n");
|
|
result = -EINVAL;
|
|
goto out;
|
|
}
|
|
hdr = ptr;
|
|
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;
|
|
}
|
|
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;
|
|
}
|
|
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;
|
|
|
|
if (is_multicast_ether_addr(eth_hdr->h_dest)) {
|
|
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 {
|
|
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:
|
|
return result;
|
|
}
|
|
EXPORT_SYMBOL_GPL(wlp_prepare_tx_frame);
|