--- libaitio/src/bpf.c	2013/06/26 12:27:40	1.1.2.14
+++ libaitio/src/bpf.c	2013/06/26 15:31:17	1.1.2.18
@@ -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;
@@ -178,6 +178,7 @@ 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);
@@ -218,45 +219,36 @@ 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, void ** __restrict zcache, struct bpf_zbuf * __restrict zbuf)
 {
-	ssize_t rlen = -1;
+	ssize_t rlen = 0;
 	struct bpf_zbuf_header *bzh;
 
 	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 A");
+			rlen = atomic_load_acq_int(&bzh->bzh_kernel_len);
+		}
 	} 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 B");
+			rlen = atomic_load_acq_int(&bzh->bzh_kernel_len);
+		}
 	}
 
 	return rlen;
@@ -277,6 +269,15 @@ io_etherRecv(int eth, void * __restrict buf, size_t bu
 {
 	ssize_t rlen = 0;
 	void *zcache = NULL;
+#ifdef __FreeBSD__
+	struct bpf_zbuf bz;
+	struct bpf_zbuf_header *bzh;
+#else
+	if (zcbuf) {
+		io_SetErr(ENOTSUP, "bpf zero copy buffer mode is not supported");
+		return -1;
+	}
+#endif
 
 	if (!buf || !buflen) {
 		io_SetErr(EINVAL, "invalid arguments");
@@ -289,8 +290,18 @@ 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, &zcache, (struct bpf_zbuf*) zcbuf);
+			if (rlen > 0) {
+				bzh = (struct bpf_zbuf_header*) zcache;
+				memcpy(buf, zcache + sizeof(struct bpf_zbuf_header), 
+						MIN(buflen, rlen));
+			}
+			if (!rlen && !ioctl(eth, BIOCROTZBUF, &bz))
+				continue;
+		} while (0);
 #else
+		rlen = -1;
 		io_SetErr(ENOTSUP, "bpf zero copy buffer mode is not supported");
 #endif
 	}