--- libaitio/src/bpf.c	2013/06/25 16:42:41	1.1.2.12
+++ libaitio/src/bpf.c	2013/06/26 16:22:12	1.1.2.19
@@ -154,7 +154,7 @@ io_etherOpen(const char *csIface, int flags, int whdr,
 			close(eth);
 			return -1;
 		}
-		if (ioctl(eth, BIOCSETZBUF, (struct bpf_zbuf*) *zcbuf) == -1) {
+		if (ioctl(eth, BIOCSETZBUF, *zcbuf) == -1) {
 			LOGERR;
 			io_etherClose(eth, zcbuf);
 			return -1;
@@ -164,17 +164,6 @@ io_etherOpen(const char *csIface, int flags, int whdr,
 #endif
 	}
 
-	if (ioctl(eth, BIOCIMMEDIATE, &n) == -1) {
-		LOGERR;
-		close(eth);
-		return -1;
-	}
-	if (whdr && ioctl(eth, BIOCSHDRCMPLT, &n) == -1) {
-		LOGERR;
-		close(eth);
-		return -1;
-	}
-
 	if (csIface)
 		strlcpy(szStr, csIface, sizeof szStr);
 	else if (io_get1stiface(szStr, sizeof szStr) == -1) {
@@ -189,6 +178,18 @@ io_etherOpen(const char *csIface, int flags, int whdr,
 		return -1;
 	}
 
+	n = 1;
+	if (whdr && ioctl(eth, BIOCSHDRCMPLT, &n) == -1) {
+		LOGERR;
+		io_etherClose(eth, zcbuf);
+		return -1;
+	}
+	if (ioctl(eth, BIOCIMMEDIATE, &n) == -1) {
+		LOGERR;
+		io_etherClose(eth, zcbuf);
+		return -1;
+	}
+
 	return eth;
 }
 
@@ -218,47 +219,43 @@ io_etherSend(int eth, const void *buf, size_t buflen)
 
 #ifdef __FreeBSD__
 static inline void
-ackZCbuf(struct bpf_zbuf_header * __restrict bzh)
+ackZCbuf(struct bpf_zbuf_header *bzh)
 {
 	atomic_store_rel_int(&bzh->bzh_user_gen, bzh->bzh_kernel_gen);
 }
 
 static inline int
-chkZCbuf(struct bpf_zbuf_header * __restrict bzh)
+chkZCbuf(struct bpf_zbuf_header *bzh)
 {
 	/* return true if userspace owns buffer, and false otherwise. */
 	return (bzh->bzh_user_gen != atomic_load_acq_int(&bzh->bzh_kernel_gen));
 }
 
 static inline ssize_t
-nextZCbuf(void ** __restrict zcache, struct bpf_zbuf * __restrict zbuf, 
-		const void * __restrict buf)
+nextZCbuf(int eth, struct bpf_zbuf * __restrict zbuf, void * __restrict buf, size_t buflen)
 {
-	ssize_t rlen = -1;
+	ssize_t rlen = 0;
+	struct bpf_zbuf bz;
 	struct bpf_zbuf_header *bzh;
+	off_t pos = 0;
 
-	if (!*zcache || *zcache == zbuf->bz_bufb) {
-		bzh = (struct bpf_zbuf_header *) zbuf->bz_bufa;
-		if (chkZCbuf(bzh)) {
-			rlen = atomic_load_acq_int(&bzh->bzh_kernel_len);
-			*zcache = zbuf->bz_bufa;
-			if (buf)
-				buf = ((caddr_t) *zcache) + sizeof(struct bpf_zbuf_header);
-			ackZCbuf(bzh);
-		} else
-			io_SetErr(EAGAIN, "kernel owns the buffer");
-	} else if (*zcache == zbuf->bz_bufa) {
-		bzh = (struct bpf_zbuf_header *) zbuf->bz_bufb;
-		if (chkZCbuf(bzh)) {
-			rlen = atomic_load_acq_int(&bzh->bzh_kernel_len);
-			*zcache = zbuf->bz_bufb;
-			if (buf)
-				buf = ((caddr_t) *zcache) + sizeof(struct bpf_zbuf_header);
-			ackZCbuf(bzh);
-		} else
-			io_SetErr(EAGAIN, "kernel owns the buffer");
+	bzh = (struct bpf_zbuf_header *) zbuf->bz_bufa;
+	if (chkZCbuf(bzh)) {
+		rlen = MIN(atomic_load_acq_int(&bzh->bzh_kernel_len), buflen);
+		memcpy(buf + pos, zbuf->bz_bufa + sizeof(struct bpf_zbuf_header), rlen);
+		ackZCbuf(bzh);
+		pos += rlen;
 	}
+	bzh = (struct bpf_zbuf_header *) zbuf->bz_bufb;
+	if (chkZCbuf(bzh)) {
+		rlen = MIN(atomic_load_acq_int(&bzh->bzh_kernel_len), buflen);
+		memcpy(buf + pos, zbuf->bz_bufb + sizeof(struct bpf_zbuf_header), rlen);
+		ackZCbuf(bzh);
+		pos += rlen;
+	}
 
+	if (!pos)
+		ioctl(eth, BIOCROTZBUF, &bz);
 	return rlen;
 }
 #endif
@@ -276,7 +273,6 @@ ssize_t
 io_etherRecv(int eth, void * __restrict buf, size_t buflen, void * __restrict zcbuf)
 {
 	ssize_t rlen = 0;
-	void **zcache = NULL;
 
 	if (!buf || !buflen) {
 		io_SetErr(EINVAL, "invalid arguments");
@@ -289,8 +285,13 @@ io_etherRecv(int eth, void * __restrict buf, size_t bu
 			LOGERR;
 	} else {
 #ifdef __FreeBSD__
-		rlen = nextZCbuf(zcache, (struct bpf_zbuf*) zcbuf, buf);
+		do {
+			rlen = nextZCbuf(eth, (struct bpf_zbuf*) zcbuf, buf, buflen);
+			if (!rlen)
+				continue;
+		} while (0);
 #else
+		rlen = -1;
 		io_SetErr(ENOTSUP, "bpf zero copy buffer mode is not supported");
 #endif
 	}