bsd: Use correct size for routing socket

The buffer size for routing socket is fixed to 2048.
This patch fix it to obtain the size from OS.

This patch worked on x86 platform with NetBSD 5.0.2.

src/drivers/driver_bsd.c

@@ -15,6 +15,7 @@
 
 #include "includes.h"
 #include <sys/ioctl.h>
+#include <sys/sysctl.h>
 
 #include "common.h"
 #include "driver.h"
@@ -569,6 +570,21 @@ bsd_set_opt_ie(void *priv, const u8 *ie, size_t ie_len)
 	return 0;
 }
 
+static int
+rtbuf_len(void)
+{
+	size_t len;
+
+	int mib[6] = {CTL_NET, AF_ROUTE, 0, AF_INET6, NET_RT_DUMP, 0};
+
+	if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0) {
+		wpa_printf(MSG_ERROR, "%s failed: %s\n", __func__,
+			   strerror(errno));
+		return -1;
+	}
+
+	return len;
+}
 
 #ifdef HOSTAPD
 
@@ -691,26 +707,39 @@ static void
 bsd_wireless_event_receive(int sock, void *ctx, void *sock_ctx)
 {
 	struct bsd_driver_data *drv = ctx;
-	char buf[2048] __attribute__ ((aligned (4)));
+	char *buf;
 	struct if_announcemsghdr *ifan;
 	struct rt_msghdr *rtm;
 	struct ieee80211_michael_event *mic;
 	struct ieee80211_join_event *join;
 	struct ieee80211_leave_event *leave;
-	int n;
+	int n, len;
 	union wpa_event_data data;
 
-	n = read(sock, buf, sizeof(buf));
+	len = rtbuf_len();
+	if (len < 0)
+		return;
+
+	buf = os_malloc(len);
+	if (buf == NULL) {
+		wpa_printf(MSG_ERROR, "%s os_malloc() failed\n", __func__);
+		return;
+	}
+
+	n = read(sock, buf, len);
 	if (n < 0) {
 		if (errno != EINTR && errno != EAGAIN)
-			perror("read(PF_ROUTE)");
+			wpa_printf(MSG_ERROR, "%s read() failed: %s\n",
+				   __func__, strerror(errno));
+		os_free(buf);
 		return;
 	}
 
 	rtm = (struct rt_msghdr *) buf;
 	if (rtm->rtm_version != RTM_VERSION) {
-		wpa_printf(MSG_DEBUG, "Routing message version %d not "
+		wpa_printf(MSG_DEBUG, "Invalid routing message version=%d",
-			"understood\n", rtm->rtm_version);
+			   rtm->rtm_version);
+		os_free(buf);
 		return;
 	}
 	ifan = (struct if_announcemsghdr *) rtm;
@@ -751,6 +780,7 @@ bsd_wireless_event_receive(int sock, void *ctx, void *sock_ctx)
 		}
 		break;
 	}
+	os_free(buf);
 }
 
 static void
@@ -1115,7 +1145,7 @@ static void
 wpa_driver_bsd_event_receive(int sock, void *ctx, void *sock_ctx)
 {
 	struct bsd_driver_data *drv = sock_ctx;
-	char buf[2048] __attribute__ ((aligned (4)));
+	char *buf;
 	struct if_announcemsghdr *ifan;
 	struct if_msghdr *ifm;
 	struct rt_msghdr *rtm;
@@ -1123,19 +1153,32 @@ wpa_driver_bsd_event_receive(int sock, void *ctx, void *sock_ctx)
 	struct ieee80211_michael_event *mic;
 	struct ieee80211_leave_event *leave;
 	struct ieee80211_join_event *join;
-	int n;
+	int n, len;
 
-	n = read(sock, buf, sizeof(buf));
+	len = rtbuf_len();
+	if (len < 0)
+		return;
+
+	buf = os_malloc(len);
+	if (buf == NULL) {
+		wpa_printf(MSG_ERROR, "%s os_malloc() failed\n", __func__);
+		return;
+	}
+
+	n = read(sock, buf, len);
 	if (n < 0) {
 		if (errno != EINTR && errno != EAGAIN)
-			perror("read(PF_ROUTE)");
+			wpa_printf(MSG_ERROR, "%s read() failed: %s\n",
+				   __func__, strerror(errno));
+		os_free(buf);
 		return;
 	}
 
 	rtm = (struct rt_msghdr *) buf;
 	if (rtm->rtm_version != RTM_VERSION) {
-		wpa_printf(MSG_DEBUG, "Routing message version %d not "
+		wpa_printf(MSG_DEBUG, "Invalid routing message version=%d",
-			"understood\n", rtm->rtm_version);
+			   rtm->rtm_version);
+		os_free(buf);
 		return;
 	}
 	os_memset(&event, 0, sizeof(event));
@@ -1150,6 +1193,7 @@ wpa_driver_bsd_event_receive(int sock, void *ctx, void *sock_ctx)
 		case IFAN_DEPARTURE:
 			event.interface_status.ievent = EVENT_INTERFACE_REMOVED;
 		default:
+			os_free(buf);
 			return;
 		}
 		wpa_printf(MSG_DEBUG, "RTM_IFANNOUNCE: Interface '%s' %s",
@@ -1222,6 +1266,7 @@ wpa_driver_bsd_event_receive(int sock, void *ctx, void *sock_ctx)
 		}
 		break;
 	}
+	os_free(buf);
 }
 
 static void