Use a shared helper function for merging supported rate lists

Signed-hostap: Jouni Malinen <j@w1.fi>

src/ap/ap_list.c

@@ -251,23 +251,9 @@ void ap_list_process_beacon(struct hostapd_iface *iface,
 		ap->ssid_len = len;
 	}
 
-	os_memset(ap->supported_rates, 0, WLAN_SUPP_RATES_MAX);
-	len = 0;
-	if (elems->supp_rates) {
-		len = elems->supp_rates_len;
-		if (len > WLAN_SUPP_RATES_MAX)
-			len = WLAN_SUPP_RATES_MAX;
-		os_memcpy(ap->supported_rates, elems->supp_rates, len);
-	}
-	if (elems->ext_supp_rates) {
-		int len2;
-		if (len + elems->ext_supp_rates_len > WLAN_SUPP_RATES_MAX)
-			len2 = WLAN_SUPP_RATES_MAX - len;
-		else
-			len2 = elems->ext_supp_rates_len;
-		os_memcpy(ap->supported_rates + len, elems->ext_supp_rates,
-			  len2);
-	}
+	merge_byte_arrays(ap->supported_rates, WLAN_SUPP_RATES_MAX,
+			  elems->supp_rates, elems->supp_rates_len,
+			  elems->ext_supp_rates, elems->ext_supp_rates_len);
 
 	ap->wpa = elems->wpa_ie != NULL;
 

src/ap/ieee802_11.c

@@ -586,35 +586,20 @@ static u16 copy_supp_rates(struct hostapd_data *hapd, struct sta_info *sta,
 		return WLAN_STATUS_UNSPECIFIED_FAILURE;
 	}
 
-	if (elems->supp_rates_len > sizeof(sta->supported_rates)) {
+	if (elems->supp_rates_len + elems->ext_supp_rates_len >
+	    sizeof(sta->supported_rates)) {
 		hostapd_logger(hapd, sta->addr, HOSTAPD_MODULE_IEEE80211,
 			       HOSTAPD_LEVEL_DEBUG,
-			       "Invalid supported rates element length %d",
-			       elems->supp_rates_len);
+			       "Invalid supported rates element length %d+%d",
+			       elems->supp_rates_len,
+			       elems->ext_supp_rates_len);
 		return WLAN_STATUS_UNSPECIFIED_FAILURE;
 	}
 
-	os_memset(sta->supported_rates, 0, sizeof(sta->supported_rates));
-	os_memcpy(sta->supported_rates, elems->supp_rates,
-		  elems->supp_rates_len);
-	sta->supported_rates_len = elems->supp_rates_len;
-
-	if (elems->ext_supp_rates) {
-		if (elems->supp_rates_len + elems->ext_supp_rates_len >
-		    sizeof(sta->supported_rates)) {
-			hostapd_logger(hapd, sta->addr,
-				       HOSTAPD_MODULE_IEEE80211,
-				       HOSTAPD_LEVEL_DEBUG,
-				       "Invalid supported rates element length"
-				       " %d+%d", elems->supp_rates_len,
-				       elems->ext_supp_rates_len);
-			return WLAN_STATUS_UNSPECIFIED_FAILURE;
-		}
-
-		os_memcpy(sta->supported_rates + elems->supp_rates_len,
-			  elems->ext_supp_rates, elems->ext_supp_rates_len);
-		sta->supported_rates_len += elems->ext_supp_rates_len;
-	}
+	sta->supported_rates_len = merge_byte_arrays(
+		sta->supported_rates, sizeof(sta->supported_rates),
+		elems->supp_rates, elems->supp_rates_len,
+		elems->ext_supp_rates, elems->ext_supp_rates_len);
 
 	return WLAN_STATUS_SUCCESS;
 }

src/utils/common.c

@@ -578,3 +578,35 @@ int is_hex(const u8 *data, size_t len)
 	}
 	return 0;
 }
+
+
+size_t merge_byte_arrays(u8 *res, size_t res_len,
+			 const u8 *src1, size_t src1_len,
+			 const u8 *src2, size_t src2_len)
+{
+	size_t len = 0;
+
+	os_memset(res, 0, res_len);
+
+	if (src1) {
+		if (src1_len >= res_len) {
+			os_memcpy(res, src1, res_len);
+			return res_len;
+		}
+
+		os_memcpy(res, src1, src1_len);
+		len += src1_len;
+	}
+
+	if (src2) {
+		if (len + src2_len >= res_len) {
+			os_memcpy(res + len, src2, res_len - len);
+			return res_len;
+		}
+
+		os_memcpy(res + len, src2, src2_len);
+		len += src2_len;
+	}
+
+	return len;
+}

src/utils/common.h

@@ -448,6 +448,9 @@ const char * wpa_ssid_txt(const u8 *ssid, size_t ssid_len);
 
 char * wpa_config_parse_string(const char *value, size_t *len);
 int is_hex(const u8 *data, size_t len);
+size_t merge_byte_arrays(u8 *res, size_t res_len,
+			 const u8 *src1, size_t src1_len,
+			 const u8 *src2, size_t src2_len);
 
 static inline int is_zero_ether_addr(const u8 *a)
 {