diff options
author | Ilan Peer <ilan.peer@intel.com> | 2022-09-06 10:48:56 +0200 |
---|---|---|
committer | Johannes Berg <johannes.berg@intel.com> | 2022-10-07 15:23:55 +0200 |
commit | 45ebac4f059b92906e7e86dd1a780739f883857c (patch) | |
tree | 8fb032c367162fb482973e8e2fcba0866c57925a | |
parent | wifi: cfg80211/mac80211: Fix ML element common size validation (diff) | |
download | linux-45ebac4f059b92906e7e86dd1a780739f883857c.tar.xz linux-45ebac4f059b92906e7e86dd1a780739f883857c.zip |
wifi: mac80211: Parse station profile from association response
When processing an association response frame for a Multi-Link
connection, extract the per station profile for each additional
link, and use it for parsing the link elements.
As the Multi-Link element might be fragmented, add support for
reassembling a fragmented element. To simplify memory management
logic, extend 'struct ieee802_11_elems' to hold a scratch buffer,
which is used for the defragmentation. Once an element is
reconstructed in the scratch area, point the corresponding element
pointer to it. Currently only defragmentation of Multi-Link element
and the contained per-STA profile subelement is supported.
Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
-rw-r--r-- | include/linux/ieee80211.h | 1 | ||||
-rw-r--r-- | net/mac80211/ieee80211_i.h | 26 | ||||
-rw-r--r-- | net/mac80211/mlme.c | 17 | ||||
-rw-r--r-- | net/mac80211/util.c | 150 |
4 files changed, 188 insertions, 6 deletions
diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h index b935a85b2f44..f51e939f28f2 100644 --- a/include/linux/ieee80211.h +++ b/include/linux/ieee80211.h @@ -4666,6 +4666,7 @@ static inline bool ieee80211_mle_size_ok(const u8 *data, size_t len) enum ieee80211_mle_subelems { IEEE80211_MLE_SUBELEM_PER_STA_PROFILE = 0, + IEEE80211_MLE_SUBELEM_FRAGMENT = 254, }; #define IEEE80211_MLE_STA_CONTROL_LINK_ID 0x000f diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 4e1d4c339f2d..5dcbc8de53fd 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -1707,8 +1707,27 @@ struct ieee802_11_elems { u8 tx_pwr_env_num; u8 eht_cap_len; + /* mult-link element can be de-fragmented and thus u8 is not sufficient */ + size_t multi_link_len; + + /* + * store the per station profile pointer and length in case that the + * parsing also handled Multi-Link element parsing for a specific link + * ID. + */ + struct ieee80211_mle_per_sta_profile *prof; + size_t sta_prof_len; + /* whether a parse error occurred while retrieving these elements */ bool parse_error; + + /* + * scratch buffer that can be used for various element parsing related + * tasks, e.g., element de-fragmentation etc. + */ + size_t scratch_len; + u8 *scratch_pos; + u8 scratch[]; }; static inline struct ieee80211_local *hw_to_local( @@ -2197,9 +2216,13 @@ static inline void ieee80211_tx_skb(struct ieee80211_sub_if_data *sdata, * represent a non-transmitting BSS in which case the data * for that non-transmitting BSS is returned * @link_id: the link ID to parse elements for, if a STA profile - * is present in the multi-link element, or -1 to ignore + * is present in the multi-link element, or -1 to ignore; + * note that the code currently assumes parsing an association + * (or re-association) response frame if this is given * @from_ap: frame is received from an AP (currently used only * for EHT capabilities parsing) + * @scratch_len: if non zero, specifies the requested length of the scratch + * buffer; otherwise, 'len' is used. */ struct ieee80211_elems_parse_params { const u8 *start; @@ -2210,6 +2233,7 @@ struct ieee80211_elems_parse_params { struct cfg80211_bss *bss; int link_id; bool from_ap; + size_t scratch_len; }; struct ieee802_11_elems * diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index 54b8d5065bbd..a7e06c8ddaf3 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -3923,11 +3923,12 @@ static bool ieee80211_assoc_config_link(struct ieee80211_link_data *link, struct ieee80211_mgd_assoc_data *assoc_data = sdata->u.mgd.assoc_data; struct ieee80211_bss_conf *bss_conf = link->conf; struct ieee80211_local *local = sdata->local; + unsigned int link_id = link->link_id; struct ieee80211_elems_parse_params parse_params = { .start = elem_start, .len = elem_len, .bss = cbss, - .link_id = link == &sdata->deflink ? -1 : link->link_id, + .link_id = link_id == assoc_data->assoc_link_id ? -1 : link_id, .from_ap = true, }; bool is_6ghz = cbss->channel->band == NL80211_BAND_6GHZ; @@ -3942,8 +3943,18 @@ static bool ieee80211_assoc_config_link(struct ieee80211_link_data *link, if (!elems) return false; - /* FIXME: use from STA profile element after parsing that */ - capab_info = le16_to_cpu(mgmt->u.assoc_resp.capab_info); + if (link_id == assoc_data->assoc_link_id) { + capab_info = le16_to_cpu(mgmt->u.assoc_resp.capab_info); + } else if (!elems->prof) { + ret = false; + goto out; + } else { + const u8 *ptr = elems->prof->variable + + elems->prof->sta_info_len - 1; + + /* FIXME: need to also handle the status code */ + capab_info = get_unaligned_le16(ptr); + } if (!is_s1g && !elems->supp_rates) { sdata_info(sdata, "no SuppRates element in AssocResp\n"); diff --git a/net/mac80211/util.c b/net/mac80211/util.c index bf7461c41bef..40b75fa82b15 100644 --- a/net/mac80211/util.c +++ b/net/mac80211/util.c @@ -1026,8 +1026,10 @@ ieee80211_parse_extension_element(u32 *crc, elems->eht_operation = data; break; case WLAN_EID_EXT_EHT_MULTI_LINK: - if (ieee80211_mle_size_ok(data, len)) + if (ieee80211_mle_size_ok(data, len)) { elems->multi_link = (void *)data; + elems->multi_link_len = len; + } break; } } @@ -1497,6 +1499,145 @@ static size_t ieee802_11_find_bssid_profile(const u8 *start, size_t len, return found ? profile_len : 0; } +static void ieee80211_defragment_element(struct ieee802_11_elems *elems, + void **elem_ptr, size_t *len, + size_t total_len, u8 frag_id) +{ + u8 *data = *elem_ptr, *pos, *start; + const struct element *elem; + + /* + * Since 'data' points to the data of the element, not the element + * itself, allow 254 in case it was an extended element where the + * extended ID isn't part of the data we see here and thus not part of + * 'len' either. + */ + if (!data || (*len != 254 && *len != 255)) + return; + + start = elems->scratch_pos; + + if (WARN_ON(*len > (elems->scratch + elems->scratch_len - + elems->scratch_pos))) + return; + + memcpy(elems->scratch_pos, data, *len); + elems->scratch_pos += *len; + + pos = data + *len; + total_len -= *len; + for_each_element(elem, pos, total_len) { + if (elem->id != frag_id) + break; + + if (WARN_ON(elem->datalen > + (elems->scratch + elems->scratch_len - + elems->scratch_pos))) + return; + + memcpy(elems->scratch_pos, elem->data, elem->datalen); + elems->scratch_pos += elem->datalen; + + *len += elem->datalen; + } + + *elem_ptr = start; +} + +static void ieee80211_mle_get_sta_prof(struct ieee802_11_elems *elems, + u8 link_id) +{ + const struct ieee80211_multi_link_elem *ml = elems->multi_link; + size_t ml_len = elems->multi_link_len; + const struct element *sub; + + if (!ml || !ml_len) + return; + + if (le16_get_bits(ml->control, IEEE80211_ML_CONTROL_TYPE) != + IEEE80211_ML_CONTROL_TYPE_BASIC) + return; + + for_each_mle_subelement(sub, (u8 *)ml, ml_len) { + struct ieee80211_mle_per_sta_profile *prof = (void *)sub->data; + u16 control; + + if (sub->id != IEEE80211_MLE_SUBELEM_PER_STA_PROFILE) + continue; + + if (!ieee80211_mle_sta_prof_size_ok(sub->data, sub->datalen)) + return; + + control = le16_to_cpu(prof->control); + + if (link_id != u16_get_bits(control, + IEEE80211_MLE_STA_CONTROL_LINK_ID)) + continue; + + if (!(control & IEEE80211_MLE_STA_CONTROL_COMPLETE_PROFILE)) + return; + + elems->prof = prof; + elems->sta_prof_len = sub->datalen; + + /* the sub element can be fragmented */ + ieee80211_defragment_element(elems, (void **)&elems->prof, + &elems->sta_prof_len, + ml_len - (sub->data - (u8 *)ml), + IEEE80211_MLE_SUBELEM_FRAGMENT); + return; + } +} + +static void ieee80211_mle_parse_link(struct ieee802_11_elems *elems, + struct ieee80211_elems_parse_params *params) +{ + struct ieee80211_mle_per_sta_profile *prof; + struct ieee80211_elems_parse_params sub = { + .action = params->action, + .from_ap = params->from_ap, + .link_id = -1, + }; + const struct element *non_inherit = NULL; + const u8 *end; + + if (params->link_id == -1) + return; + + ieee80211_defragment_element(elems, (void **)&elems->multi_link, + &elems->multi_link_len, + elems->total_len - ((u8 *)elems->multi_link - + elems->ie_start), + WLAN_EID_FRAGMENT); + + ieee80211_mle_get_sta_prof(elems, params->link_id); + prof = elems->prof; + + if (!prof) + return; + + /* check if we have the 4 bytes for the fixed part in assoc response */ + if (elems->sta_prof_len < sizeof(*prof) + prof->sta_info_len - 1 + 4) { + elems->prof = NULL; + elems->sta_prof_len = 0; + return; + } + + /* + * Skip the capability information and the status code that are expected + * as part of the station profile in association response frames. Note + * the -1 is because the 'sta_info_len' is accounted to as part of the + * per-STA profile, but not part of the 'u8 variable[]' portion. + */ + sub.start = prof->variable + prof->sta_info_len - 1 + 4; + end = (const u8 *)prof + elems->sta_prof_len; + sub.len = end - sub.start; + + non_inherit = cfg80211_find_ext_elem(WLAN_EID_EXT_NON_INHERITANCE, + sub.start, sub.len); + _ieee802_11_parse_elems_full(&sub, elems, non_inherit); +} + struct ieee802_11_elems * ieee802_11_parse_elems_full(struct ieee80211_elems_parse_params *params) { @@ -1504,12 +1645,15 @@ ieee802_11_parse_elems_full(struct ieee80211_elems_parse_params *params) const struct element *non_inherit = NULL; u8 *nontransmitted_profile; int nontransmitted_profile_len = 0; + size_t scratch_len = params->scratch_len ?: 2 * params->len; - elems = kzalloc(sizeof(*elems), GFP_ATOMIC); + elems = kzalloc(sizeof(*elems) + scratch_len, GFP_ATOMIC); if (!elems) return NULL; elems->ie_start = params->start; elems->total_len = params->len; + elems->scratch_len = scratch_len; + elems->scratch_pos = elems->scratch; nontransmitted_profile = kmalloc(params->len, GFP_ATOMIC); if (nontransmitted_profile) { @@ -1537,6 +1681,8 @@ ieee802_11_parse_elems_full(struct ieee80211_elems_parse_params *params) _ieee802_11_parse_elems_full(&sub, elems, NULL); } + ieee80211_mle_parse_link(elems, params); + if (elems->tim && !elems->parse_error) { const struct ieee80211_tim_ie *tim_ie = elems->tim; |