[patch] Work with ARP floods

dhcpcd-arp.patch (text/plain), 4.08 KB, created by Roy Marples (RETIRED) on 2007-08-07 08:42:15 UTC

Index: arp.c
===================================================================
--- arp.c	(revision 255)
+++ arp.c	(working copy)
@@ -105,6 +105,8 @@
 	int nprobes = 0;
 	int nclaims = 0;
 	struct in_addr null_address;
+	struct timeval stopat;
+	struct timeval now;
 
 	if (! iface->arpable) {
 		logger (LOG_DEBUG, "interface `%s' is not ARPable", iface->name);
@@ -130,20 +132,26 @@
 		int buflen = sizeof (char *) * iface->buffer_length;
 		fd_set rset;
 		int bytes;
-		int s;
+		int s = 0;
 
-		tv.tv_sec = 0; 
-		tv.tv_usec = timeout;
+		/* Only select if we have a timeout */
+		if (timeout > 0) {
+			tv.tv_sec = 0; 
+			tv.tv_usec = timeout;
 
-		FD_ZERO (&rset);
-		FD_SET (iface->fd, &rset);
-		errno = 0;
-		if ((s = select (FD_SETSIZE, &rset, NULL, NULL, &tv)) == -1) {
-			if (errno != EINTR)
-				logger (LOG_ERR, "select: `%s'", strerror (errno));
-			break;
-		} else if (s == 0) {
-			/* Timed out */
+			FD_ZERO (&rset);
+			FD_SET (iface->fd, &rset);
+
+			errno = 0;
+			if ((s = select (FD_SETSIZE, &rset, NULL, NULL, &tv)) == -1) {
+				if (errno != EINTR)
+					logger (LOG_ERR, "select: `%s'", strerror (errno));
+				break;
+			}
+		}
+
+		/* Timed out */
+		if (s == 0) {
 			if (nprobes < NPROBES) {
 				nprobes ++;
 				timeout = PROBE_INTERVAL;
@@ -159,8 +167,23 @@
 				retval = 0;
 				break;
 			}
+
+			/* Setup our stop time */
+			if (get_time (&stopat) != 0)
+				break;
+			stopat.tv_usec += timeout;
+
+			continue;
 		}
-		
+
+		/* We maybe ARP flooded, so check our time */
+		if (get_time (&now) != 0)
+			break;
+		if (timercmp (&now, &stopat, >)) {
+			timeout = 0;
+			continue;
+		}
+
 		if (! FD_ISSET (iface->fd, &rset))
 			continue;
 
Index: Makefile
===================================================================
--- Makefile	(revision 264)
+++ Makefile	(working copy)
@@ -1,4 +1,4 @@
-VERSION = 3.1.3
+VERSION = 3.1.4_pre2
 CFLAGS ?= -O2 -pipe
 
 # Should work for both GNU make and BSD make
@@ -49,12 +49,16 @@
 dhcpcd_OBJS = arp.o client.o common.o configure.o dhcp.o dhcpcd.o duid.o \
 		info.o interface.o ipv4ll.o logger.o signals.o socket.o
 
-# By default we don't need to link to anything
-# Except on Darwin where we need -lresolv, so they need to uncomment this
-#dhcpcd_LIBS = -lresolv
+# These are nasty hacks to work out what libs we need to link to
+# We require librt for glibc bases systems
+LIBRT != ldd /bin/date 2>/dev/null | grep -q /librt.so && echo "-lrt" || exit 0
+LIBRT ?= $(shell ldd /bin/date 2>/dev/null | grep -q /librt.so && echo "-lrt")
 
+# Darwin needs this, but we have no way of detecting this atm
+#LIBRESOLV = -lresolv
+
 dhcpcd: $(dhcpcd_H) $(dhcpcd_OBJS)
-	$(CC) $(LDFLAGS) $(dhcpcd_OBJS) $(dhcpcd_LIBS) -o dhcpcd
+	$(CC) $(LDFLAGS) $(dhcpcd_OBJS) $(LIBRT) $(LIBRESOLV) -o dhcpcd
 
 version.h:
 	echo '#define VERSION "$(VERSION)"' > version.h
Index: common.c
===================================================================
--- common.c	(revision 254)
+++ common.c	(working copy)
@@ -76,17 +76,22 @@
 #  endif
 #endif
 
-/* This requires us to link to rt on glibc, so we use sysinfo instead */
-#ifdef __linux__
-#include <sys/sysinfo.h>
-long uptime (void)
+/* Handy function to get the time. */
+int get_time(struct timeval *tp)
 {
-	struct sysinfo info;
+	struct timespec ts;
 
-	sysinfo (&info);
-	return info.uptime;
+	if (clock_gettime (CLOCK_MONOTONIC, &ts) == -1) {
+		logger (LOG_ERR, "clock_gettime: %s", strerror (errno));
+		return (-1);
+	}
+
+	tp->tv_sec = ts.tv_sec;
+	tp->tv_usec = ts.tv_nsec / 1000;
+	return (0);
 }
-#elif __APPLE__
+
+#ifdef __APPLE__
 /* Darwin doesn't appear to have an uptime, so try and make one ourselves */
 long uptime (void)
 {
Index: common.h
===================================================================
--- common.h	(revision 244)
+++ common.h	(working copy)
@@ -23,6 +23,7 @@
 #define COMMON_H
 
 /* string.h pulls in features.h so the below define checks work */
+#include <sys/time.h>
 #include <string.h>
 
 /* Only GLIBC doesn't support strlcpy */
@@ -36,6 +37,7 @@
 void srandomdev (void);
 #endif
 
+int get_time(struct timeval *tp);
 long uptime (void);
 void *xmalloc (size_t size);
 char *xstrdup (const char *str);