Changes to build on musl/alpine

common.c

@@ -54,3 +54,26 @@ nvlist_ptr new_property_nvlist() {
 int property_nvlist_add(nvlist_ptr list, const char *prop, const char *value) {
 	return nvlist_add_string(list, prop, value);
 }
+
+int redirect_libzfs_stdout(int to) {
+	int save, res;
+	save = dup(STDOUT_FILENO);
+	if (save < 0) {
+		return save;
+	}
+	res = dup2(to, STDOUT_FILENO);
+	if (res < 0) {
+		return res;
+	}
+	return save;
+}
+
+int restore_libzfs_stdout(int saved) {
+	int res;
+	fflush(stdout);
+	res = dup2(saved, STDOUT_FILENO);
+	if (res < 0) {
+		return res;
+	}
+	close(saved);
+}

common.go

@@ -9,7 +9,7 @@
 package zfs
 
 /*
-#cgo CFLAGS: -I /usr/include/libzfs -I /usr/include/libspl -DHAVE_IOCTL_IN_SYS_IOCTL_H
+#cgo CFLAGS: -I /usr/include/libzfs -I /usr/include/libspl -DHAVE_IOCTL_IN_SYS_IOCTL_H -D_GNU_SOURCE
 #cgo LDFLAGS: -lzfs -lzpool -lnvpair
 
 #include <stdlib.h>

common.h

@@ -2,6 +2,9 @@
  * using libzfs from go language, make go code shorter and more readable.
  */
 
+#ifndef loff_t
+	#define loff_t off_t
+#endif
 #define INT_MAX_NAME 256
 #define INT_MAX_VALUE 1024
 #define	ZAP_OLDMAXVALUELEN 1024
@@ -35,3 +38,6 @@ void free_properties(property_list_t *root);
 nvlist_ptr new_property_nvlist();
 int property_nvlist_add(nvlist_ptr ptr, const char* prop, const char *value);
 
+int redirect_libzfs_stdout(int to);
+int restore_libzfs_stdout(int saved);
+

sendrecv.go

@@ -230,13 +230,12 @@ func (d *Dataset) SendSize(FromName string, flags SendFlags) (size int64, err er
 	defer r.Close()
 	go func() {
 		var tmpe error
-		saveOut := C.dup(C.fileno(C.stdout))
+		saveOut := C.redirect_libzfs_stdout(C.int(w.Fd()))
-		if res := C.dup2(C.int(w.Fd()), C.fileno(C.stdout)); res < 0 {
+		if saveOut < 0 {
-			tmpe = fmt.Errorf("Redirection of zfslib stdout failed %d", res)
+			tmpe = fmt.Errorf("Redirection of zfslib stdout failed %d", saveOut)
 		} else {
 			tmpe = d.send(FromName, w, &flags)
-			C.fflush(C.stdout)
+			C.restore_libzfs_stdout(saveOut)
-			C.dup2(saveOut, C.fileno(C.stdout))
 		}
 		w.Close()
 		errch <- tmpe

zpool.h

@@ -79,7 +79,7 @@ nvlist_ptr get_zpool_vdev_tree(nvlist_ptr nv);
 
 nvlist_ptr go_zpool_search_import(libzfs_handle_ptr zfsh, int paths, char **path, boolean_t do_scan);
 
-__uint64_t set_zpool_vdev_online(zpool_list_t *pool, const char *path, int flags);
+uint64_t set_zpool_vdev_online(zpool_list_t *pool, const char *path, int flags);
 int set_zpool_vdev_offline(zpool_list_t *pool, const char *path, boolean_t istmp, boolean_t force);
 int do_zpool_clear(zpool_list_t *pool, const char *device, u_int32_t rewind_policy);
 

zpool_vdev.c

@@ -8,7 +8,7 @@
 #include "zpool.h"
 
 
-__uint64_t set_zpool_vdev_online(zpool_list_t *pool, const char *path, int flags) {
+uint64_t set_zpool_vdev_online(zpool_list_t *pool, const char *path, int flags) {
 	vdev_state_t newstate = VDEV_STATE_UNKNOWN;
 	zpool_vdev_online(pool->zph, path, flags, &newstate);
 	return newstate;