1 files changed, 42 insertions, 0 deletions
diff --git a/libhw_generic/include/libhw/generic/io.h b/libhw_generic/include/libhw/generic/io.h
index 9128bd3..a7f7378 100644
--- a/libhw_generic/include/libhw/generic/io.h
+++ b/libhw_generic/include/libhw/generic/io.h
@@ -8,6 +8,7 @@
 #define _LIBHW_GENERIC_IO_H_
 
 #include <stddef.h>    /* for size_t */
+#include <sys/types.h> /* for ssize_t */
 
 #include <libobj/obj.h>
 
@@ -31,6 +32,29 @@ struct duplex_iovec {
 /* basic interfaces ***********************************************************/
 
 /**
+ * Return bytes-read on success, 0 on EOF, -errno on error; a short
+ * read is *not* an error.
+ */
+#define io_reader_LO_IFACE \
+	LO_FUNC(ssize_t, readv, const struct iovec *iov, int iovcnt)
+LO_INTERFACE(io_reader)
+#define io_readv(r, iov, iovcnt) LO_CALL(r, readv, iov, iovcnt)
+#define io_read(r, buf, count) LO_CALL(r, readv, &((struct iovec){.iov_base = buf, .iov_len = count}), 1)
+
+/**
+ * Return `count` on success, -errno on error; a short write *is* an
+ * error.
+ *
+ * Writes are *not* guaranteed to be atomic, so if you have concurrent
+ * writers then you should arrange for a mutex to protect the writer.
+ */
+#define io_writer_LO_IFACE \
+	LO_FUNC(ssize_t, writev, const struct iovec *iov, int iovcnt)
+LO_INTERFACE(io_writer)
+#define io_writev(w, iov, iovcnt) LO_CALL(w, writev, iov, iovcnt)
+#define io_write(w, buf, count) LO_CALL(w, writev, &((struct iovec){.iov_base = buf, .iov_len = count}), 1)
+
+/**
  * Return 0 on success, -errno on error.
  */
 #define io_closer_LO_IFACE \
@@ -49,4 +73,22 @@ LO_INTERFACE(io_bidi_closer)
 #define io_close_read(c) LO_CALL(c, close_read)
 #define io_close_write(c) LO_CALL(c, close_write)
 
+/**
+ * Return bytes-read and bytes-written on success, -errno on error; a
+ * short read/write *is* an error.
+ */
+#define io_duplex_readwriter_LO_IFACE \
+	LO_FUNC(void, readwritev, const struct duplex_iovec *iov, int iovcnt)
+LO_INTERFACE(io_duplex_readwriter)
+
+#define io_readwritev(rw, iov, iovcnt) \
+	LO_CALL(rw, readwritev, iov, iovcnt)
+
+/* aggregate interfaces *******************************************************/
+
+#define io_readwriter_LO_IFACE \
+	LO_NEST(io_reader) \
+	LO_NEST(io_writer)
+LO_INTERFACE(io_readwriter)
+
 #endif /* _LIBHW_GENERIC_IO_H_ */