--- libaitio/src/bpf.c	2013/06/26 13:33:55	1.1.2.16
+++ libaitio/src/bpf.c	2013/06/26 16:34:28	1.1.2.20
@@ -219,38 +219,46 @@ 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 size_t
-nextZCbuf(void ** __restrict zcache, struct bpf_zbuf * __restrict zbuf)
+static ssize_t
+nextZCbuf(int eth, struct bpf_zbuf * __restrict zbuf, void * __restrict buf, size_t buflen)
 {
-	size_t rlen = 0;
+	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;
-		}
-	} 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;
-		}
+	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) {
+		if ((rlen = ioctl(eth, BIOCROTZBUF, &bz)) == -1)
+			LOGERR;
+	} else
+		rlen = pos;
 	return rlen;
 }
 #endif
@@ -268,10 +276,6 @@ ssize_t
 io_etherRecv(int eth, void * __restrict buf, size_t buflen, void * __restrict zcbuf)
 {
 	ssize_t rlen = 0;
-	void *zcache = NULL;
-#ifdef __FreeBSD__
-	struct bpf_zbuf_header *bzh;
-#endif
 
 	if (!buf || !buflen) {
 		io_SetErr(EINVAL, "invalid arguments");
@@ -284,12 +288,9 @@ io_etherRecv(int eth, void * __restrict buf, size_t bu
 			LOGERR;
 	} else {
 #ifdef __FreeBSD__
-		rlen = (ssize_t) nextZCbuf(&zcache, (struct bpf_zbuf*) zcbuf);
-		if (rlen > 0) {
-			bzh = (struct bpf_zbuf_header*) zcache;
-			memcpy(buf, zcache + sizeof(struct bpf_zbuf_header), buflen);
-			ackZCbuf(bzh);
-		}
+		rlen = nextZCbuf(eth, (struct bpf_zbuf*) zcbuf, buf, buflen);
+		if (!rlen)
+			rlen = nextZCbuf(eth, (struct bpf_zbuf*) zcbuf, buf, buflen);
 #else
 		rlen = -1;
 		io_SetErr(ENOTSUP, "bpf zero copy buffer mode is not supported");