1 files changed, 102 insertions, 0 deletions
diff --git a/lib/util/iov_buf.h b/lib/util/iov_buf.h
new file mode 100644
index 0000000..cb330de
--- /dev/null
+++ b/lib/util/iov_buf.h
@@ -0,0 +1,102 @@
+/*
+ * Unix SMB/CIFS implementation.
+ * Samba system utilities
+ * Copyright (C) Volker Lendecke 2014
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __LIB_IOV_BUF_H__
+#define __LIB_IOV_BUF_H__
+
+#include "replace.h"
+#include <talloc.h>
+#include "system/filesys.h"
+
+static inline
+ssize_t iov_buf(const struct iovec *iov, int iovcnt,
+		uint8_t *buf, size_t buflen)
+{
+	size_t needed = 0;
+	uint8_t *p = buf;
+	int i;
+
+	for (i=0; i<iovcnt; i++) {
+		size_t thislen = iov[i].iov_len;
+		size_t tmp;
+
+		tmp = needed + thislen;
+
+		if (tmp < needed) {
+			/* wrap */
+			return -1;
+		}
+		needed = tmp;
+
+		if ((p != NULL) && needed <= buflen && thislen > 0) {
+			memcpy(p, iov[i].iov_base, thislen);
+			p += thislen;
+		}
+	}
+
+	return needed;
+}
+
+static inline
+ssize_t iov_buflen(const struct iovec *iov, int iovcnt)
+{
+	return iov_buf(iov, iovcnt, NULL, 0);
+}
+
+static inline
+bool iov_advance(struct iovec **iov, int *iovcnt, size_t n)
+{
+	struct iovec *v = *iov;
+	int cnt = *iovcnt;
+
+	while (n > 0) {
+		if (cnt == 0) {
+			return false;
+		}
+		if (n < v->iov_len) {
+			v->iov_base = (char *)v->iov_base + n;
+			v->iov_len -= n;
+			break;
+		}
+		n -= v->iov_len;
+		v += 1;
+		cnt -= 1;
+	}
+
+	/*
+	 * Skip 0-length iovec's
+	 *
+	 * There might be empty buffers at the end of iov. Next time we do a
+	 * readv/writev based on this iov would give 0 transferred bytes, also
+	 * known as EPIPE. So we need to be careful discarding them.
+	 */
+
+	while ((cnt > 0) && (v->iov_len == 0)) {
+		v += 1;
+		cnt -= 1;
+	}
+
+	*iov = v;
+	*iovcnt = cnt;
+	return true;
+}
+
+uint8_t *iov_concat(TALLOC_CTX *mem_ctx, const struct iovec *iov, int count);
+
+#endif