[PATCH 2/5] Add NetEm XML recipe parsing support

[Jiri Prochazka]

This patch adds parsing of XML elements identifying NetEm parameters.
Along with parsing, basic syntax check is executed, checking if
mandatory attributes are correctly entered.

Signed-off-by: Jiri Prochazka <jprochaz(a)redhat.com&gt;
---
 lnst/Controller/RecipeParser.py | 63 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)

diff --git a/lnst/Controller/RecipeParser.py b/lnst/Controller/RecipeParser.py
index 7269820..73422f1 100644
--- a/lnst/Controller/RecipeParser.py
+++ b/lnst/Controller/RecipeParser.py
@@ -111,6 +111,11 @@ class RecipeParser(XmlParser):
         if self._has_attribute(iface_tag, "netns"):
             iface["netns"] = self._get_attribute(iface_tag, "netns")
 
+        # netem
+        netem_tag = iface_tag.find("netem")
+        if netem_tag is not None:
+            iface["netem"] = self._process_netem(netem_tag)
+
         # params
         params_tag = iface_tag.find("params")
         params = self._process_params(params_tag)
@@ -269,6 +274,64 @@ class RecipeParser(XmlParser):
 
         return options
 
+    def _validate_netem(self, options, netem_op, netem_tag):
+        if netem_op == "delay":
+            valid = False
+            jitter = False
+            correlation = False
+            distribution = False
+            valid_distributions = ["normal", "uniform",
"pareto", "paretonormal"]
+            for opt in options:
+                if "time" in opt.values():
+                    valid = True
+                elif "distribution" in opt.values():
+                    if opt["value"] not in valid_distributions:
+                        raise RecipeError("netem: invalid distribution type",
netem_tag)
+                    else:
+                        distribution = True
+                elif "jitter" in opt.values():
+                    jitter =  True
+                elif "correlation" in opt.values():
+                    correlation = True
+            if not jitter:
+                if correlation or distribution:
+                    raise RecipeError("netem: jitter option is mandatory when using
<correlation> or <distribution>", netem_tag)
+            if not valid:
+                raise RecipeError("netem: time option is mandatory for
<delay>", netem_tag)
+        elif netem_op == "loss":
+            for opt in options:
+                if "percent" in opt.values():
+                    return
+            raise RecipeError("netem: percent option is mandatory for
<loss>", netem_tag)
+        elif netem_op == "duplication":
+            for opt in options:
+                if "percent" in opt.values():
+                    return
+            raise RecipeError("netem: percent option is mandatory for
<duplication>", netem_tag)
+        elif netem_op == "corrupt":
+            for opt in options:
+                if "percent" in opt.values():
+                    return
+            raise RecipeError("netem: percent option is mandatory for
<corrupt>", netem_tag)
+        elif netem_op == "reordering":
+            for opt in options:
+                if "percent" in opt.values():
+                    return
+            raise RecipeError("netem: percent option is mandatory for
<reordering>", netem_tag)
+
+    def _process_netem(self, netem_tag):
+        interface = XmlData(netem_tag)
+        # params
+        for netem_op in ["delay", "loss", "duplication",
"corrupt", "reordering"]:
+            netem_op_tag = netem_tag.find(netem_op)
+            if netem_op_tag is not None:
+                options_tag = netem_op_tag.find("options")
+                options = self._process_options(options_tag)
+                if len(options) > 0:
+                    self._validate_netem(options, netem_op, netem_tag)
+                    interface[netem_op] = options
+        return interface
+
     def _process_task(self, task_tag):
         task = XmlData(task_tag)
 
-- 
2.1.0