- 根目录:
- drivers
- uwb
- ie.c
/*
* Ultra Wide Band
* Information Element Handling
*
* Copyright (C) 2005-2006 Intel Corporation
* Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
* 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/slab.h>
#include <linux/export.h>
#include "uwb-internal.h"
/**
* uwb_ie_next - get the next IE in a buffer
* @ptr: start of the buffer containing the IE data
* @len: length of the buffer
*
* Both @ptr and @len are updated so subsequent calls to uwb_ie_next()
* will get the next IE.
*
* NULL is returned (and @ptr and @len will not be updated) if there
* are no more IEs in the buffer or the buffer is too short.
*/
struct uwb_ie_hdr *uwb_ie_next(void **ptr, size_t *len)
{
struct uwb_ie_hdr *hdr;
size_t ie_len;
if (*len < sizeof(struct uwb_ie_hdr))
return NULL;
hdr = *ptr;
ie_len = sizeof(struct uwb_ie_hdr) + hdr->length;
if (*len < ie_len)
return NULL;
*ptr += ie_len;
*len -= ie_len;
return hdr;
}
EXPORT_SYMBOL_GPL(uwb_ie_next);
/**
* uwb_ie_dump_hex - print IEs to a character buffer
* @ies: the IEs to print.
* @len: length of all the IEs.
* @buf: the destination buffer.
* @size: size of @buf.
*
* Returns the number of characters written.
*/
int uwb_ie_dump_hex(const struct uwb_ie_hdr *ies, size_t len,
char *buf, size_t size)
{
void *ptr;
const struct uwb_ie_hdr *ie;
int r = 0;
u8 *d;
ptr = (void *)ies;
for (;;) {
ie = uwb_ie_next(&ptr, &len);
if (!ie)
break;
r += scnprintf(buf + r, size - r, "%02x %02x",
(unsigned)ie->element_id,
(unsigned)ie->length);
d = (uint8_t *)ie + sizeof(struct uwb_ie_hdr);
while (d != ptr && r < size)
r += scnprintf(buf + r, size - r, " %02x", (unsigned)*d++);
if (r < size)
buf[r++] = '\n';
};
return r;
}
/**
* Get the IEs that a radio controller is sending in its beacon
*
* @uwb_rc: UWB Radio Controller
* @returns: Size read from the system
*
* We don't need to lock the uwb_rc's mutex because we don't modify
* anything. Once done with the iedata buffer, call
* uwb_rc_ie_release(iedata). Don't call kfree on it.
*/
static
ssize_t uwb_rc_get_ie(struct uwb_rc *uwb_rc, struct uwb_rc_evt_get_ie **pget_ie)
{
ssize_t result;
struct device *dev = &uwb_rc->uwb_dev.dev;
struct uwb_rccb *cmd = NULL;
struct uwb_rceb *reply = NULL;
struct uwb_rc_evt_get_ie *get_ie;
cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
if (cmd == NULL)
return -ENOMEM;
cmd->bCommandType = UWB_RC_CET_GENERAL;
cmd->wCommand = cpu_to_le16(UWB_RC_CMD_GET_IE);
result = uwb_rc_vcmd(uwb_rc, "GET_IE", cmd, sizeof(*cmd),
UWB_RC_CET_GENERAL, UWB_RC_CMD_GET_IE,
&reply);
kfree(cmd);
if (result < 0)
return result;
get_ie = container_of(reply, struct uwb_rc_evt_get_ie, rceb);
if (result < sizeof(*get_ie)) {
dev_err(dev, "not enough data returned for decoding GET IE "
"(%zu bytes received vs %zu needed)\n",
result, sizeof(*get_ie));
return -EINVAL;
} else if (result < sizeof(*get_ie) + le16_to_cpu(get_ie->wIELength)) {
dev_err(dev, "not enough data returned for decoding GET IE "
"payload (%zu bytes received vs %zu needed)\n", result,
sizeof(*get_ie) + le16_to_cpu(get_ie->wIELength));
return -EINVAL;
}
*pget_ie = get_ie;
return result;
}
/**
* Replace all IEs currently being transmitted by a device
*
* @cmd: pointer to the SET-IE command with the IEs to set
* @size: size of @buf
*/
int uwb_rc_set_ie(struct uwb_rc *rc, struct uwb_rc_cmd_set_ie *cmd)
{
int result;
struct device *dev = &rc->uwb_dev.dev;
struct uwb_rc_evt_set_ie reply;
reply.rceb.bEventType = UWB_RC_CET_GENERAL;
reply.rceb.wEvent = UWB_RC_CMD_SET_IE;
result = uwb_rc_cmd(rc, "SET-IE", &cmd->rccb,
sizeof(*cmd) + le16_to_cpu(cmd->wIELength),
&reply.rceb, sizeof(reply));
if (result < 0)
goto error_cmd;
else if (result != sizeof(reply)) {
dev_err(dev, "SET-IE: not enough data to decode reply "
"(%d bytes received vs %zu needed)\n",
result, sizeof(reply));
result = -EIO;
} else if (reply.bResultCode != UWB_RC_RES_SUCCESS) {
dev_err(dev, "SET-IE: command execution failed: %s (%d)\n",
uwb_rc_strerror(reply.bResultCode), reply.bResultCode);
result = -EIO;
} else
result = 0;
error_cmd:
return result;
}
/* Cleanup the whole IE management subsystem */
void uwb_rc_ie_init(struct uwb_rc *uwb_rc)
{
mutex_init(&uwb_rc->ies_mutex);
}
/**
* uwb_rc_ie_setup - setup a radio controller's IE manager
* @uwb_rc: the radio controller.
*
* The current set of IEs are obtained from the hardware with a GET-IE
* command (since the radio controller is not yet beaconing this will
* be just the hardware's MAC and PHY Capability IEs).
*
* Returns 0 on success; -ve on an error.
*/
int uwb_rc_ie_setup(struct uwb_rc *uwb_rc)
{
struct uwb_rc_evt_get_ie *ie_info = NULL;
int capacity;
capacity = uwb_rc_get_ie(uwb_rc, &ie_info);
if (capacity < 0)
return capacity;
mutex_lock(&uwb_rc->ies_mutex);
uwb_rc->ies = (struct uwb_rc_cmd_set_ie *)ie_info;
uwb_rc->ies->rccb.bCommandType = UWB_RC_CET_GENERAL;
uwb_rc->ies->rccb.wCommand = cpu_to_le16(UWB_RC_CMD_SET_IE);
uwb_rc->ies_capacity = capacity;
mutex_unlock(&uwb_rc->ies_mutex);
return 0;
}
/* Cleanup the whole IE management subsystem */
void uwb_rc_ie_release(struct uwb_rc *uwb_rc)
{
kfree(uwb_rc->ies);
uwb_rc->ies = NULL;
uwb_rc->ies_capacity = 0;
}
static int uwb_rc_ie_add_one(struct uwb_rc *rc, const struct uwb_ie_hdr *new_ie)
{
struct uwb_rc_cmd_set_ie *new_ies;
void *ptr, *prev_ie;
struct uwb_ie_hdr *ie;
size_t length, new_ie_len, new_capacity, size, prev_size;
length = le16_to_cpu(rc->ies->wIELength);
new_ie_len = sizeof(struct uwb_ie_hdr) + new_ie->length;
new_capacity = sizeof(struct uwb_rc_cmd_set_ie) + length + new_ie_len;
if (new_capacity > rc->ies_capacity) {
new_ies = krealloc(rc->ies, new_capacity, GFP_KERNEL);
if (!new_ies)
return -ENOMEM;
rc->ies = new_ies;
}
ptr = rc->ies->IEData;
size = length;
for (;;) {
prev_ie = ptr;
prev_size = size;
ie = uwb_ie_next(&ptr, &size);
if (!ie || ie->element_id > new_ie->element_id)
break;
}
memmove(prev_ie + new_ie_len, prev_ie, prev_size);
memcpy(prev_ie, new_ie, new_ie_len);
rc->ies->wIELength = cpu_to_le16(length + new_ie_len);
return 0;
}
/**
* uwb_rc_ie_add - add new IEs to the radio controller's beacon
* @uwb_rc: the radio controller.
* @ies: the buffer containing the new IE or IEs to be added to
* the device's beacon.
* @size: length of all the IEs.
*
* According to WHCI 0.95 [4.13.6] the driver will only receive the RCEB
* after the device sent the first beacon that includes the IEs specified
* in the SET IE command. We thus cannot send this command if the device is
* not beaconing. Instead, a SET IE command will be sent later right after
* we start beaconing.
*
* Setting an IE on the device will overwrite all current IEs in device. So
* we take the current IEs being transmitted by the device, insert the
* new one, and call SET IE with all the IEs needed.
*
* Returns 0 on success; or -ENOMEM.
*/
int uwb_rc_ie_add(struct uwb_rc *uwb_rc,
const struct uwb_ie_hdr *ies, size_t size)
{
int result = 0;
void *ptr;
const struct uwb_ie_hdr *ie;
mutex_lock(&uwb_rc->ies_mutex);
ptr = (void *)ies;
for (;;) {
ie = uwb_ie_next(&ptr, &size);
if (!ie)
break;
result = uwb_rc_ie_add_one(uwb_rc, ie);
if (result < 0)
break;
}
if (result >= 0) {
if (size == 0) {
if (uwb_rc->beaconing != -1)
result = uwb_rc_set_ie(uwb_rc, uwb_rc->ies);
} else
result = -EINVAL;
}
mutex_unlock(&uwb_rc->ies_mutex);
return result;
}
EXPORT_SYMBOL_GPL(uwb_rc_ie_add);
/*
* Remove an IE from internal cache
*
* We are dealing with our internal IE cache so no need to verify that the
* IEs are valid (it has been done already).
*
* Should be called with ies_mutex held
*
* We do not break out once an IE is found in the cache. It is currently
* possible to have more than one IE with the same ID included in the
* beacon. We don't reallocate, we just mark the size smaller.
*/
static
void uwb_rc_ie_cache_rm(struct uwb_rc *uwb_rc, enum uwb_ie to_remove)
{
struct uwb_ie_hdr *ie;
size_t len = le16_to_cpu(uwb_rc->ies->wIELength);
void *ptr;
size_t size;
ptr = uwb_rc->ies->IEData;
size = len;
for (;;) {
ie = uwb_ie_next(&ptr, &size);
if (!ie)
break;
if (ie->element_id == to_remove) {
len -= sizeof(struct uwb_ie_hdr) + ie->length;
memmove(ie, ptr, size);
ptr = ie;
}
}
uwb_rc->ies->wIELength = cpu_to_le16(len);
}
/**
* uwb_rc_ie_rm - remove an IE from the radio controller's beacon
* @uwb_rc: the radio controller.
* @element_id: the element ID of the IE to remove.
*
* Only IEs previously added with uwb_rc_ie_add() may be removed.
*
* Returns 0 on success; or -ve the SET-IE command to the radio
* controller failed.
*/
int uwb_rc_ie_rm(struct uwb_rc *uwb_rc, enum uwb_ie element_id)
{
int result = 0;
mutex_lock(&uwb_rc->ies_mutex);
uwb_rc_ie_cache_rm(uwb_rc, element_id);
if (uwb_rc->beaconing != -1)
result = uwb_rc_set_ie(uwb_rc, uwb_rc->ies);
mutex_unlock(&uwb_rc->ies_mutex);
return result;
}
EXPORT_SYMBOL_GPL(uwb_rc_ie_rm);