diff options
Diffstat (limited to 'drivers/uwb/ie.c')
| -rw-r--r-- | drivers/uwb/ie.c | 541 |
1 files changed, 541 insertions, 0 deletions
diff --git a/drivers/uwb/ie.c b/drivers/uwb/ie.c new file mode 100644 index 0000000..cf6f3d1 --- /dev/null +++ b/drivers/uwb/ie.c @@ -0,0 +1,541 @@ +/* + * 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 "uwb-internal.h" +#define D_LOCAL 0 +#include <linux/uwb/debug.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); + +/** + * 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. + */ +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; + + d_fnstart(3, dev, "(%p, %p)\n", uwb_rc, pget_ie); + result = -ENOMEM; + cmd = kzalloc(sizeof(*cmd), GFP_KERNEL); + if (cmd == NULL) + goto error_kzalloc; + 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); + if (result < 0) + goto error_cmd; + 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)); + result = -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)); + result = -EINVAL; + } else + *pget_ie = get_ie; +error_cmd: + kfree(cmd); +error_kzalloc: + d_fnend(3, dev, "(%p, %p) = %d\n", uwb_rc, pget_ie, (int)result); + return result; +} +EXPORT_SYMBOL_GPL(uwb_rc_get_ie); + + +/* + * Given a pointer to an IE, print it in ASCII/hex followed by a new line + * + * @ie_hdr: pointer to the IE header. Length is in there, and it is + * guaranteed that the ie_hdr->length bytes following it are + * safely accesible. + * + * @_data: context data passed from uwb_ie_for_each(), an struct output_ctx + */ +int uwb_ie_dump_hex(struct uwb_dev *uwb_dev, const struct uwb_ie_hdr *ie_hdr, + size_t offset, void *_ctx) +{ + struct uwb_buf_ctx *ctx = _ctx; + const u8 *pl = (void *)(ie_hdr + 1); + u8 pl_itr; + + ctx->bytes += scnprintf(ctx->buf + ctx->bytes, ctx->size - ctx->bytes, + "%02x %02x ", (unsigned) ie_hdr->element_id, + (unsigned) ie_hdr->length); + pl_itr = 0; + while (pl_itr < ie_hdr->length && ctx->bytes < ctx->size) + ctx->bytes += scnprintf(ctx->buf + ctx->bytes, + ctx->size - ctx->bytes, + "%02x ", (unsigned) pl[pl_itr++]); + if (ctx->bytes < ctx->size) + ctx->buf[ctx->bytes++] = '\n'; + return 0; +} +EXPORT_SYMBOL_GPL(uwb_ie_dump_hex); + + +/** + * Verify that a pointer in a buffer points to valid IE + * + * @start: pointer to start of buffer in which IE appears + * @itr: pointer to IE inside buffer that will be verified + * @top: pointer to end of buffer + * + * @returns: 0 if IE is valid, <0 otherwise + * + * Verification involves checking that the buffer can contain a + * header and the amount of data reported in the IE header can be found in + * the buffer. + */ +static +int uwb_rc_ie_verify(struct uwb_dev *uwb_dev, const void *start, + const void *itr, const void *top) +{ + struct device *dev = &uwb_dev->dev; + const struct uwb_ie_hdr *ie_hdr; + + if (top - itr < sizeof(*ie_hdr)) { + dev_err(dev, "Bad IE: no data to decode header " + "(%zu bytes left vs %zu needed) at offset %zu\n", + top - itr, sizeof(*ie_hdr), itr - start); + return -EINVAL; + } + ie_hdr = itr; + itr += sizeof(*ie_hdr); + if (top - itr < ie_hdr->length) { + dev_err(dev, "Bad IE: not enough data for payload " + "(%zu bytes left vs %zu needed) at offset %zu\n", + top - itr, (size_t)ie_hdr->length, + (void *)ie_hdr - start); + return -EINVAL; + } + return 0; +} + + +/** + * Walk a buffer filled with consecutive IE's a buffer + * + * @uwb_dev: UWB device this IEs belong to (for err messages mainly) + * + * @fn: function to call with each IE; if it returns 0, we keep + * traversing the buffer. If it returns !0, we'll stop and return + * that value. + * + * @data: pointer passed to @fn + * + * @buf: buffer where the consecutive IEs are located + * + * @size: size of @buf + * + * Each IE is checked for basic correctness (there is space left for + * the header and the payload). If that test is failed, we stop + * processing. For every good IE, @fn is called. + */ +ssize_t uwb_ie_for_each(struct uwb_dev *uwb_dev, uwb_ie_f fn, void *data, + const void *buf, size_t size) +{ + ssize_t result = 0; + const struct uwb_ie_hdr *ie_hdr; + const void *itr = buf, *top = itr + size; + + while (itr < top) { + if (uwb_rc_ie_verify(uwb_dev, buf, itr, top) != 0) + break; + ie_hdr = itr; + itr += sizeof(*ie_hdr) + ie_hdr->length; + result = fn(uwb_dev, ie_hdr, itr - buf, data); + if (result != 0) + break; + } + return result; +} +EXPORT_SYMBOL_GPL(uwb_ie_for_each); + + +/** + * 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; +} + +/** + * Determine by IE id if IE is host settable + * WUSB 1.0 [8.6.2.8 Table 8.85] + * + * EXCEPTION: + * All but UWB_IE_WLP appears in Table 8.85 from WUSB 1.0. Setting this IE + * is required for the WLP substack to perform association with its WSS so + * we hope that the WUSB spec will be changed to reflect this. + */ +static +int uwb_rc_ie_is_host_settable(enum uwb_ie element_id) +{ + if (element_id == UWB_PCA_AVAILABILITY || + element_id == UWB_BP_SWITCH_IE || + element_id == UWB_MAC_CAPABILITIES_IE || + element_id == UWB_PHY_CAPABILITIES_IE || + element_id == UWB_APP_SPEC_PROBE_IE || + element_id == UWB_IDENTIFICATION_IE || + element_id == UWB_MASTER_KEY_ID_IE || + element_id == UWB_IE_WLP || + element_id == UWB_APP_SPEC_IE) + return 1; + return 0; +} + + +/** + * Extract Host Settable IEs from IE + * + * @ie_data: pointer to buffer containing all IEs + * @size: size of buffer + * + * @returns: length of buffer that only includes host settable IEs + * + * Given a buffer of IEs we move all Host Settable IEs to front of buffer + * by overwriting the IEs that are not Host Settable. + * Buffer length is adjusted accordingly. + */ +static +ssize_t uwb_rc_parse_host_settable_ie(struct uwb_dev *uwb_dev, + void *ie_data, size_t size) +{ + size_t new_len = size; + struct uwb_ie_hdr *ie_hdr; + size_t ie_length; + void *itr = ie_data, *top = itr + size; + + while (itr < top) { + if (uwb_rc_ie_verify(uwb_dev, ie_data, itr, top) != 0) + break; + ie_hdr = itr; + ie_length = sizeof(*ie_hdr) + ie_hdr->length; + if (uwb_rc_ie_is_host_settable(ie_hdr->element_id)) { + itr += ie_length; + } else { + memmove(itr, itr + ie_length, top - (itr + ie_length)); + new_len -= ie_length; + top -= ie_length; + } + } + return new_len; +} + + +/* Cleanup the whole IE management subsystem */ +void uwb_rc_ie_init(struct uwb_rc *uwb_rc) +{ + mutex_init(&uwb_rc->ies_mutex); +} + + +/** + * Set up cache for host settable IEs currently being transmitted + * + * First we just call GET-IE to get the current IEs being transmitted + * (or we workaround and pretend we did) and (because the format is + * the same) reuse that as the IE cache (with the command prefix, as + * explained in 'struct uwb_rc'). + * + * @returns: size of cache created + */ +ssize_t uwb_rc_ie_setup(struct uwb_rc *uwb_rc) +{ + struct device *dev = &uwb_rc->uwb_dev.dev; + ssize_t result; + size_t capacity; + struct uwb_rc_evt_get_ie *ie_info; + + d_fnstart(3, dev, "(%p)\n", uwb_rc); + mutex_lock(&uwb_rc->ies_mutex); + result = uwb_rc_get_ie(uwb_rc, &ie_info); + if (result < 0) + goto error_get_ie; + capacity = result; + d_printf(5, dev, "Got IEs %zu bytes (%zu long at %p)\n", result, + (size_t)le16_to_cpu(ie_info->wIELength), ie_info); + + /* Remove IEs that host should not set. */ + result = uwb_rc_parse_host_settable_ie(&uwb_rc->uwb_dev, + ie_info->IEData, le16_to_cpu(ie_info->wIELength)); + if (result < 0) + goto error_parse; + d_printf(5, dev, "purged non-settable IEs to %zu bytes\n", result); + uwb_rc->ies = (void *) 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; + d_printf(5, dev, "IE cache at %p %zu bytes, %zu capacity\n", + ie_info, result, capacity); + result = 0; +error_parse: +error_get_ie: + mutex_unlock(&uwb_rc->ies_mutex); + d_fnend(3, dev, "(%p) = %zu\n", uwb_rc, result); + return result; +} + + +/* 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 __acc_size(struct uwb_dev *uwb_dev, const struct uwb_ie_hdr *ie_hdr, + size_t offset, void *_ctx) +{ + size_t *acc_size = _ctx; + *acc_size += sizeof(*ie_hdr) + ie_hdr->length; + d_printf(6, &uwb_dev->dev, "new acc size %zu\n", *acc_size); + return 0; +} + + +/** + * Add a new IE to IEs currently being transmitted by device + * + * @ies: the buffer containing the new IE or IEs to be added to + * the device's beacon. The buffer will be verified for + * consistence (meaning the headers should be right) and + * consistent with the buffer size. + * @size: size of @ies (in bytes, total buffer size) + * @returns: 0 if ok, <0 errno code on error + * + * 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, append the + * new one, and call SET IE with all the IEs needed. + * + * The local IE cache will only be updated with the new IE if SET IE + * completed successfully. + */ +int uwb_rc_ie_add(struct uwb_rc *uwb_rc, + const struct uwb_ie_hdr *ies, size_t size) +{ + int result = 0; + struct device *dev = &uwb_rc->uwb_dev.dev; + struct uwb_rc_cmd_set_ie *new_ies; + size_t ies_size, total_size, acc_size = 0; + + if (uwb_rc->ies == NULL) + return -ESHUTDOWN; + uwb_ie_for_each(&uwb_rc->uwb_dev, __acc_size, &acc_size, ies, size); + if (acc_size != size) { + dev_err(dev, "BUG: bad IEs, misconstructed headers " + "[%zu bytes reported vs %zu calculated]\n", + size, acc_size); + WARN_ON(1); + return -EINVAL; + } + mutex_lock(&uwb_rc->ies_mutex); + ies_size = le16_to_cpu(uwb_rc->ies->wIELength); + total_size = sizeof(*uwb_rc->ies) + ies_size; + if (total_size + size > uwb_rc->ies_capacity) { + d_printf(4, dev, "Reallocating IE cache from %p capacity %zu " + "to capacity %zu\n", uwb_rc->ies, uwb_rc->ies_capacity, + total_size + size); + new_ies = kzalloc(total_size + size, GFP_KERNEL); + if (new_ies == NULL) { + dev_err(dev, "No memory for adding new IE\n"); + result = -ENOMEM; + goto error_alloc; + } + memcpy(new_ies, uwb_rc->ies, total_size); + uwb_rc->ies_capacity = total_size + size; + kfree(uwb_rc->ies); + uwb_rc->ies = new_ies; + d_printf(4, dev, "New IE cache at %p capacity %zu\n", + uwb_rc->ies, uwb_rc->ies_capacity); + } + memcpy((void *)uwb_rc->ies + total_size, ies, size); + uwb_rc->ies->wIELength = cpu_to_le16(ies_size + size); + if (uwb_rc->beaconing != -1) { + result = uwb_rc_set_ie(uwb_rc, uwb_rc->ies); + if (result < 0) { + dev_err(dev, "Cannot set new IE on device: %d\n", + result); + uwb_rc->ies->wIELength = cpu_to_le16(ies_size); + } else + result = 0; + } + d_printf(4, dev, "IEs now occupy %hu bytes of %zu capacity at %p\n", + le16_to_cpu(uwb_rc->ies->wIELength), uwb_rc->ies_capacity, + uwb_rc->ies); +error_alloc: + 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 +int uwb_rc_ie_cache_rm(struct uwb_rc *uwb_rc, enum uwb_ie to_remove) +{ + struct uwb_ie_hdr *ie_hdr; + size_t new_len = le16_to_cpu(uwb_rc->ies->wIELength); + void *itr = uwb_rc->ies->IEData; + void *top = itr + new_len; + + while (itr < top) { + ie_hdr = itr; + if (ie_hdr->element_id != to_remove) { + itr += sizeof(*ie_hdr) + ie_hdr->length; + } else { + int ie_length; + ie_length = sizeof(*ie_hdr) + ie_hdr->length; + if (top - itr != ie_length) + memmove(itr, itr + ie_length, top - itr + ie_length); + top -= ie_length; + new_len -= ie_length; + } + } + uwb_rc->ies->wIELength = cpu_to_le16(new_len); + return 0; +} + + +/** + * Remove an IE currently being transmitted by device + * + * @element_id: id of IE to be removed from device's beacon + */ +int uwb_rc_ie_rm(struct uwb_rc *uwb_rc, enum uwb_ie element_id) +{ + struct device *dev = &uwb_rc->uwb_dev.dev; + int result; + + if (uwb_rc->ies == NULL) + return -ESHUTDOWN; + mutex_lock(&uwb_rc->ies_mutex); + result = uwb_rc_ie_cache_rm(uwb_rc, element_id); + if (result < 0) + dev_err(dev, "Cannot remove IE from cache.\n"); + if (uwb_rc->beaconing != -1) { + result = uwb_rc_set_ie(uwb_rc, uwb_rc->ies); + if (result < 0) + dev_err(dev, "Cannot set new IE on device.\n"); + } + mutex_unlock(&uwb_rc->ies_mutex); + return result; +} +EXPORT_SYMBOL_GPL(uwb_rc_ie_rm); |
