ead: use the new pcap features and the raw socket optimization to eliminate most of the cpu utilization overhead caused by the use of pcap live capturing

SVN-Revision: 15400

package/ead/Makefile

@@ -11,8 +11,10 @@ PKG_NAME:=ead
 PKG_RELEASE:=1
 
 PKG_BUILD_DEPENDS:=libpcap
+PKG_BUILD_DIR:=$(BUILD_DIR)/ead
 
 include $(INCLUDE_DIR)/package.mk
+include $(INCLUDE_DIR)/kernel.mk
 
 define Package/ead
   SECTION:=net
@@ -29,6 +31,7 @@ endef
 CONFIGURE_PATH = tinysrp
 
 TARGET_CFLAGS += \
+	-I$(LINUX_DIR)/include \
 	-I$(PKG_BUILD_DIR) \
 	-I$(PKG_BUILD_DIR)/tinysrp \
 	$(TARGET_CPPFLAGS)

package/ead/src/ead.c

@@ -42,6 +42,10 @@
 #include "libbridge_init.c"
 #endif
 
+#ifdef linux
+#include <linux/if_packet.h>
+#endif
+
 #define PASSWD_FILE	"/etc/passwd"
 
 #ifndef DEFAULT_IFNAME
@@ -110,6 +114,51 @@ static struct t_server *ts = NULL;
 static struct t_num A, *B = NULL;
 unsigned char *skey;
 
+static void
+set_recv_type(pcap_t *p, bool rx)
+{
+#ifdef PACKET_RECV_TYPE
+	struct sockaddr_ll sll;
+	struct ifreq ifr;
+	int ifindex, mask;
+	int fd, ret;
+
+	fd = pcap_get_selectable_fd(p);
+	if (fd < 0)
+		return;
+
+	if (rx)
+		mask = 1 << PACKET_BROADCAST;
+	else
+		mask = 0;
+
+	ret = setsockopt(fd, SOL_PACKET, PACKET_RECV_TYPE, &mask, sizeof(mask));
+#endif
+}
+
+
+static pcap_t *
+ead_open_pcap(const char *ifname, char *errbuf, bool rx)
+{
+	pcap_t *p;
+
+	p = pcap_create(ifname, errbuf);
+	if (p == NULL)
+		goto out;
+
+	pcap_set_snaplen(p, PCAP_MRU);
+	pcap_set_promisc(p, rx);
+	pcap_set_timeout(p, PCAP_TIMEOUT);
+#ifdef HAS_PROTO_EXTENSION
+	pcap_set_protocol(p, (rx ? htons(ETH_P_IP) : 0));
+#endif
+	pcap_set_buffer_size(p, (rx ? 10 : 1) * PCAP_MRU);
+	pcap_activate(p);
+	set_recv_type(p, rx);
+out:
+	return p;
+}
+
 static void
 get_random_bytes(void *ptr, int len)
 {
@@ -647,14 +696,18 @@ ead_pcap_reopen(bool first)
 
 	pcap_fp_rx = NULL;
 	do {
-		pcap_fp = pcap_open_live(instance->ifname, PCAP_MRU, 1, PCAP_TIMEOUT, errbuf);
 #ifdef linux
-		if (instance->bridge[0])
-			pcap_fp_rx = pcap_open_live(instance->bridge, PCAP_MRU, 1, PCAP_TIMEOUT, errbuf);
+		if (instance->bridge[0]) {
+			pcap_fp_rx = ead_open_pcap(instance->bridge, errbuf, 1);
+			pcap_fp = ead_open_pcap(instance->ifname, errbuf, 0);
+		} else
 #endif
+		{
+			pcap_fp = ead_open_pcap(instance->ifname, errbuf, 1);
+		}
+
 		if (!pcap_fp_rx)
 			pcap_fp_rx = pcap_fp;
-		pcap_setfilter(pcap_fp_rx, &pktfilter);
 		if (first && !pcap_fp) {
 			DEBUG(1, "WARNING: unable to open interface '%s'\n", instance->ifname);
 			first = false;
@@ -662,6 +715,7 @@ ead_pcap_reopen(bool first)
 		if (!pcap_fp)
 			sleep(1);
 	} while (!pcap_fp);
+	pcap_setfilter(pcap_fp_rx, &pktfilter);
 }