/* * Ultra Wide Band * Information Element Handling * * Copyright (C) 2005-2006 Intel Corporation * Inaky Perez-Gonzalez * Reinette Chatre * * 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 /** * 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);