From f7dacfb11475ba777e1e84ccec2e14b0ba5a17a3 Mon Sep 17 00:00:00 2001 From: Sara Sharon Date: Fri, 15 Mar 2019 17:39:03 +0200 Subject: cfg80211: support non-inheritance element Subelement profile may specify element IDs it doesn't inherit from the management frame. Support it. Signed-off-by: Sara Sharon Signed-off-by: Luca Coelho Signed-off-by: Johannes Berg --- net/wireless/scan.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 60 insertions(+), 1 deletion(-) (limited to 'net/wireless') diff --git a/net/wireless/scan.c b/net/wireless/scan.c index 49f700a1460b..bda9114ded77 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -179,12 +179,63 @@ static bool __cfg80211_unlink_bss(struct cfg80211_registered_device *rdev, return true; } +bool cfg80211_is_element_inherited(const struct element *elem, + const struct element *non_inherit_elem) +{ + u8 id_len, ext_id_len, i, loop_len, id; + const u8 *list; + + if (elem->id == WLAN_EID_MULTIPLE_BSSID) + return false; + + if (!non_inherit_elem || non_inherit_elem->datalen < 2) + return true; + + /* + * non inheritance element format is: + * ext ID (56) | IDs list len | list | extension IDs list len | list + * Both lists are optional. Both lengths are mandatory. + * This means valid length is: + * elem_len = 1 (extension ID) + 2 (list len fields) + list lengths + */ + id_len = non_inherit_elem->data[1]; + if (non_inherit_elem->datalen < 3 + id_len) + return true; + + ext_id_len = non_inherit_elem->data[2 + id_len]; + if (non_inherit_elem->datalen < 3 + id_len + ext_id_len) + return true; + + if (elem->id == WLAN_EID_EXTENSION) { + if (!ext_id_len) + return true; + loop_len = ext_id_len; + list = &non_inherit_elem->data[3 + id_len]; + id = elem->data[0]; + } else { + if (!id_len) + return true; + loop_len = id_len; + list = &non_inherit_elem->data[2]; + id = elem->id; + } + + for (i = 0; i < loop_len; i++) { + if (list[i] == id) + return false; + } + + return true; +} +EXPORT_SYMBOL(cfg80211_is_element_inherited); + static size_t cfg80211_gen_new_ie(const u8 *ie, size_t ielen, const u8 *subelement, size_t subie_len, u8 *new_ie, gfp_t gfp) { u8 *pos, *tmp; const u8 *tmp_old, *tmp_new; + const struct element *non_inherit_elem; u8 *sub_copy; /* copy subelement as we need to change its content to @@ -204,6 +255,11 @@ static size_t cfg80211_gen_new_ie(const u8 *ie, size_t ielen, pos += (tmp_new[1] + 2); } + /* get non inheritance list if exists */ + non_inherit_elem = + cfg80211_find_ext_elem(WLAN_EID_EXT_NON_INHERITANCE, + sub_copy, subie_len); + /* go through IEs in ie (skip SSID) and subelement, * merge them into new_ie */ @@ -224,8 +280,11 @@ static size_t cfg80211_gen_new_ie(const u8 *ie, size_t ielen, subie_len); if (!tmp) { + const struct element *old_elem = (void *)tmp_old; + /* ie in old ie but not in subelement */ - if (tmp_old[0] != WLAN_EID_MULTIPLE_BSSID) { + if (cfg80211_is_element_inherited(old_elem, + non_inherit_elem)) { memcpy(pos, tmp_old, tmp_old[1] + 2); pos += tmp_old[1] + 2; } -- cgit