cfg80211/mac80211: move information element parsing logic to cfg80211

Moving the parsing logic for retrieving the information elements
stored in management frames, e.g. beacons or probe responses,
and making it available to other cfg80211 drivers.

Signed-off-by: Yogesh Ashok Powar <yogeshp@marvell.com>
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 168 insertions, 0 deletions

diff --git a/net/wireless/util.c b/net/wireless/util.c
index be75a3a..844ddb0 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -6,6 +6,7 @@
 #include <linux/bitops.h>
 #include <linux/etherdevice.h>
 #include <linux/slab.h>
+#include <linux/crc32.h>
 #include <net/cfg80211.h>
 #include <net/ip.h>
 #include "core.h"
@@ -1044,3 +1045,170 @@ int ieee80211_get_ratemask(struct ieee80211_supported_band *sband,
 
 	return 0;
 }
+
+u32 ieee802_11_parse_elems_crc(u8 *start, size_t len,
+			       struct ieee802_11_elems *elems,
+			       u64 filter, u32 crc)
+{
+	size_t left = len;
+	u8 *pos = start;
+	bool calc_crc = filter != 0;
+
+	memset(elems, 0, sizeof(*elems));
+	elems->ie_start = start;
+	elems->total_len = len;
+
+	while (left >= 2) {
+		u8 id, elen;
+
+		id = *pos++;
+		elen = *pos++;
+		left -= 2;
+
+		if (elen > left)
+			break;
+
+		if (calc_crc && id < 64 && (filter & (1ULL << id)))
+			crc = crc32_be(crc, pos - 2, elen + 2);
+
+		switch (id) {
+		case WLAN_EID_SSID:
+			elems->ssid = pos;
+			elems->ssid_len = elen;
+			break;
+		case WLAN_EID_SUPP_RATES:
+			elems->supp_rates = pos;
+			elems->supp_rates_len = elen;
+			break;
+		case WLAN_EID_FH_PARAMS:
+			elems->fh_params = pos;
+			elems->fh_params_len = elen;
+			break;
+		case WLAN_EID_DS_PARAMS:
+			elems->ds_params = pos;
+			elems->ds_params_len = elen;
+			break;
+		case WLAN_EID_CF_PARAMS:
+			elems->cf_params = pos;
+			elems->cf_params_len = elen;
+			break;
+		case WLAN_EID_TIM:
+			if (elen >= sizeof(struct ieee80211_tim_ie)) {
+				elems->tim = (void *)pos;
+				elems->tim_len = elen;
+			}
+			break;
+		case WLAN_EID_IBSS_PARAMS:
+			elems->ibss_params = pos;
+			elems->ibss_params_len = elen;
+			break;
+		case WLAN_EID_CHALLENGE:
+			elems->challenge = pos;
+			elems->challenge_len = elen;
+			break;
+		case WLAN_EID_VENDOR_SPECIFIC:
+			if (elen >= 4 && pos[0] == 0x00 && pos[1] == 0x50 &&
+			    pos[2] == 0xf2) {
+				/* Microsoft OUI (00:50:F2) */
+
+				if (calc_crc)
+					crc = crc32_be(crc, pos - 2, elen + 2);
+
+				if (pos[3] == 1) {
+					/* OUI Type 1 - WPA IE */
+					elems->wpa = pos;
+					elems->wpa_len = elen;
+				} else if (elen >= 5 && pos[3] == 2) {
+					/* OUI Type 2 - WMM IE */
+					if (pos[4] == 0) {
+						elems->wmm_info = pos;
+						elems->wmm_info_len = elen;
+					} else if (pos[4] == 1) {
+						elems->wmm_param = pos;
+						elems->wmm_param_len = elen;
+					}
+				}
+			}
+			break;
+		case WLAN_EID_RSN:
+			elems->rsn = pos;
+			elems->rsn_len = elen;
+			break;
+		case WLAN_EID_ERP_INFO:
+			elems->erp_info = pos;
+			elems->erp_info_len = elen;
+			break;
+		case WLAN_EID_EXT_SUPP_RATES:
+			elems->ext_supp_rates = pos;
+			elems->ext_supp_rates_len = elen;
+			break;
+		case WLAN_EID_HT_CAPABILITY:
+			if (elen >= sizeof(struct ieee80211_ht_cap))
+				elems->ht_cap_elem = (void *)pos;
+			break;
+		case WLAN_EID_HT_INFORMATION:
+			if (elen >= sizeof(struct ieee80211_ht_info))
+				elems->ht_info_elem = (void *)pos;
+			break;
+		case WLAN_EID_MESH_ID:
+			elems->mesh_id = pos;
+			elems->mesh_id_len = elen;
+			break;
+		case WLAN_EID_MESH_CONFIG:
+			if (elen >= sizeof(struct ieee80211_meshconf_ie))
+				elems->mesh_config = (void *)pos;
+			break;
+		case WLAN_EID_PEER_LINK:
+			elems->peer_link = pos;
+			elems->peer_link_len = elen;
+			break;
+		case WLAN_EID_PREQ:
+			elems->preq = pos;
+			elems->preq_len = elen;
+			break;
+		case WLAN_EID_PREP:
+			elems->prep = pos;
+			elems->prep_len = elen;
+			break;
+		case WLAN_EID_PERR:
+			elems->perr = pos;
+			elems->perr_len = elen;
+			break;
+		case WLAN_EID_RANN:
+			if (elen >= sizeof(struct ieee80211_rann_ie))
+				elems->rann = (void *)pos;
+			break;
+		case WLAN_EID_CHANNEL_SWITCH:
+			elems->ch_switch_elem = pos;
+			elems->ch_switch_elem_len = elen;
+			break;
+		case WLAN_EID_QUIET:
+			if (!elems->quiet_elem) {
+				elems->quiet_elem = pos;
+				elems->quiet_elem_len = elen;
+			}
+			elems->num_of_quiet_elem++;
+			break;
+		case WLAN_EID_COUNTRY:
+			elems->country_elem = pos;
+			elems->country_elem_len = elen;
+			break;
+		case WLAN_EID_PWR_CONSTRAINT:
+			elems->pwr_constr_elem = pos;
+			elems->pwr_constr_elem_len = elen;
+			break;
+		case WLAN_EID_TIMEOUT_INTERVAL:
+			elems->timeout_int = pos;
+			elems->timeout_int_len = elen;
+			break;
+		default:
+			break;
+		}
+
+		left -= elen;
+		pos += elen;
+	}
+
+	return crc;
+}
+EXPORT_SYMBOL(ieee802_11_parse_elems_crc);