librecmc-fossil/trunk/tools/upslug2/patches/100-libpcap_fix.patch

--- a/pcap_wire.cc
+++ b/pcap_wire.cc
@@ -18,6 +18,7 @@
 
 #include <sys/time.h>
 #include <sys/select.h>
+#include <sys/poll.h>
 
 /* Ways of finding the hardware MAC on this machine... */
 /* This is the Linux only fallback. */
@@ -130,20 +131,18 @@ namespace NSLU2Upgrade {
 		 * non-static (real) Handler.
 		 */
 		void Handler(const struct pcap_pkthdr *packet_header, const u_char *packet) {
-			/* This should only be called once... */
-			if (captured)
-				throw std::logic_error("Handler called twice");
-
 			/* Verify the protocol and originating address of the packet, then
 			 * return this packet.
 			 */
+			if (captured)
+				return;
 			if (packet_header->caplen > 14 && (broadcast ||
 				std::memcmp(packet+6, header, 6) == 0)) {
-				/* Record the address and copy the data */
-				std::memcpy(source, packet+6, 6);
 				const size_t len(packet_header->caplen - 14);
 				if (len > captureSize)
-					throw std::logic_error("packet too long");
+					return;
+				/* Record the address and copy the data */
+				std::memcpy(source, packet+6, 6);
 				std::memcpy(captureBuffer, packet+14, len);
 				captureSize = len;
 				captured = true;
@@ -156,7 +155,7 @@ namespace NSLU2Upgrade {
 			 * packet and the buffer should be big enough.
 			 */
 			if (packet_header->caplen < packet_header->len)
-				throw std::logic_error("truncated packet");
+				return;
 
 			/*IGNORE EVIL: known evil cast */
 			reinterpret_cast<PCapWire*>(user)->Handler(packet_header, packet);
@@ -173,56 +172,24 @@ namespace NSLU2Upgrade {
 		virtual void Receive(void *buffer, size_t &size, unsigned long timeout) {
 			/* Now try to read packets until the timeout has been consumed.
 			 */
-			struct timeval tvStart;
-			if (timeout > 0 && gettimeofday(&tvStart, 0) != 0)
-				throw OSError(errno, "gettimeofday(base)");
+			int time_count;
 
 			captureBuffer = buffer;
 			captureSize = size;
 			captured = false;
+			time_count = timeout / 2000; /* 2 ms intervals */
+			time_count++;
 			do {
 				/*IGNORE EVIL: known evil cast */
-				int count(pcap_dispatch(pcap, 1, PCapHandler,
-							reinterpret_cast<u_char*>(this)));
+				int count = pcap_dispatch(pcap, 1, PCapHandler,
+							reinterpret_cast<u_char*>(this));
 
-				if (count > 0) {
-					/* Were any packets handled? */
-					if (captured) {
-						size = captureSize;
-						return;
-					}
-					/* else try again. */
-				} else if (count == 0) {
-					/* Nothing to handle - do the timeout, do this
-					 * by waiting a bit then trying again, the trick
-					 * to this is to work out how long to wait each
-					 * time, for the moment a 10ms delay is used.
-					 */
-					if (timeout == 0)
-						break;
-
-					struct timeval tvNow;
-					if (gettimeofday(&tvNow, 0) != 0)
-						throw OSError(errno, "gettimeofday(now)");
-
-					unsigned long t(tvNow.tv_sec - tvStart.tv_sec);
-					t *= 1000000;
-					t += tvNow.tv_usec;
-					t -= tvStart.tv_usec;
-					if (t > timeout)
-						break;
-
-					tvNow.tv_sec = 0;
-					tvNow.tv_usec = timeout-t;
-					if (tvNow.tv_usec > 10000)
-						tvNow.tv_usec = 10000;
-
-					/* Delay, may be interrupted - this should
-					 * be portable to the BSDs (since the
-					 * technique originates in BSD.)
-					 */
-					(void)select(0, 0, 0, 0, &tvNow);
-				} else {
+				/* Were any packets handled? */
+				if (captured) {
+					size = captureSize;
+					return;
+				}
+				if (count < 0) {
 					/* Error condition. */
 					if (count == -1) {
 						if (errno != EINTR)
@@ -232,7 +199,8 @@ namespace NSLU2Upgrade {
 					} else
 						throw std::logic_error("pcap unexpected result");
 				}
-			} while (timeout != 0);
+				time_count--;
+			} while (time_count > 0);
 
 			/* Here on timeout. */
 			size = 0;
@@ -288,6 +256,7 @@ NSLU2Upgrade::Wire *NSLU2Upgrade::Wire::
 		const unsigned char *mac, const unsigned char *address, int uid) {
 	/* This is used to store the error passed to throw. */
 	static char PCapErrbuf[PCAP_ERRBUF_SIZE];
+	struct bpf_program fp;
 
 	/* Check the device name.  If not given use 'DEFAULT_ETHERNET_IF'. */
 	if (device == NULL)
@@ -301,20 +270,12 @@ NSLU2Upgrade::Wire *NSLU2Upgrade::Wire::
 		 * for other ethernet MACs.  (Because the code above does not
 		 * check that the destination matches the device in use).
 		 */
-		pcap = pcap_open_live(device, 1540, false/*promiscuous*/, 1/*ms*/, PCapErrbuf);
+		pcap = pcap_open_live(device, 1540, false/*promiscuous*/, 2/*ms*/, PCapErrbuf);
 
 		if (pcap == NULL)
 			throw WireError(errno, PCapErrbuf);
 	}
 
-	/* Always do a non-blocking read, because the 'timeout' above
-	 * doesn't work on Linux (return is immediate) and on OSX (and
-	 * maybe other BSDs) the interface tends to hang waiting for
-	 * the timeout to expire even after receiving a single packet.
-	 */
-	if (pcap_setnonblock(pcap, true, PCapErrbuf))
-		throw WireError(errno, PCapErrbuf);
-
 	try {
 		/* The MAC of the transmitting device is needed - without
 		 * this the return packet won't go to the right place!