modules/admin-full: fix backup generation (#74)

1 files changed, 35 insertions, 6 deletions

diff --git a/modules/admin-full/luasrc/controller/admin/system.lua b/modules/admin-full/luasrc/controller/admin/system.lua
index 56010ea9e6..1aabe637a1 100644
--- a/modules/admin-full/luasrc/controller/admin/system.lua
+++ b/modules/admin-full/luasrc/controller/admin/system.lua
@@ -130,9 +130,9 @@ end
 
 function action_backup()
 	local reset_avail = os.execute([[grep '"rootfs_data"' /proc/mtd >/dev/null 2>&1]]) == 0
-	local restore_cmd = "gunzip | tar -xC/ >/dev/null 2>&1"
-	local backup_cmd  = "tar -c %s | gzip 2>/dev/null"
-	
+	local restore_cmd = "tar -xzC/ >/dev/null 2>&1"
+	local backup_cmd  = "tar -cz %s 2>/dev/null"
+
 	local restore_fpi 
 	luci.http.setfilehandler(
 		function(meta, chunk, eof)
@@ -156,12 +156,11 @@ function action_backup()
 		luci.template.render("admin_system/applyreboot")
 		luci.sys.reboot()
 	elseif backup then
-		luci.util.perror(backup_cmd:format(_keep_pattern()))
-		local backup_fpi = io.popen(backup_cmd:format(_keep_pattern()), "r")
+		local reader = ltn12_popen(backup_cmd:format(_keep_pattern()))
 		luci.http.header('Content-Disposition', 'attachment; filename="backup-%s-%s.tar.gz"' % {
 			luci.sys.hostname(), os.date("%Y-%m-%d")})
 		luci.http.prepare_content("application/x-targz")
-		luci.ltn12.pump.all(luci.ltn12.source.file(backup_fpi), luci.http.write)
+		luci.ltn12.pump.all(reader, luci.http.write)
 	elseif reset then
 		luci.template.render("admin_system/applyreboot")
 		luci.util.exec("mtd -r erase rootfs_data")
@@ -341,3 +340,33 @@ function _keep_pattern()
 	end
 	return kpattern
 end
+
+function ltn12_popen(command)
+
+	local fdi, fdo = nixio.pipe()
+	local pid = nixio.fork()
+
+	if pid > 0 then
+		fdo:close()
+		local close
+		return function()
+			local buffer = fdi:read(2048)
+			local wpid, stat = nixio.waitpid(pid, "nohang")
+			if not close and wpid and stat == "exited" then
+				close = true
+			end
+
+			if buffer and #buffer > 0 then
+				return buffer
+			elseif close then
+				fdi:close()
+				return nil
+			end
+		end
+	elseif pid == 0 then
+		nixio.dup(fdo, nixio.stdout)
+		fdi:close()
+		fdo:close()
+		nixio.exec("/bin/sh", "-c", command)
+	end
+end