Track and print rule source in drop prints

[flowspec-xdp] / genrules.py

diff --git a/genrules.py b/genrules.py
index 40fc5c1f2d84969b959e5d30fdaad8c3c29cdf20..4468c1e00e52d58fb12c9d4769ae12c95c7d2704 100755 (executable)
--- a/genrules.py
+++ b/genrules.py
@@ -12,13 +12,18 @@ IP_PROTO_TCP = 6
 IP_PROTO_UDP = 17
 
 class ASTAction(Enum):
-    OR = 1,
-    AND = 2,
-    NOT = 3,
-    EXPR = 4
+    OR = 1
+    AND = 2
+    NOT = 3
+    FALSE = 4
+    TRUE = 5
+    EXPR = 6
 class ASTNode:
     def __init__(self, action, left, right=None):
         self.action = action
+        if action == ASTAction.FALSE or action == ASTAction.TRUE:
+            assert left is None and right is None
+            return
         self.left = left
         if right is None:
             assert action == ASTAction.EXPR or action == ASTAction.NOT
@@ -32,23 +37,32 @@ class ASTNode:
             return "(" + self.left.write(expr_param, expr_param2) + ") && (" + self.right.write(expr_param, expr_param2) + ")"
         if self.action == ASTAction.NOT:
             return "!(" + self.left.write(expr_param, expr_param2) + ")"
+        if self.action == ASTAction.FALSE:
+            return "0"
+        if self.action == ASTAction.TRUE:
+            return "1"
         if self.action == ASTAction.EXPR:
             return self.left.write(expr_param, expr_param2)
 
 def parse_ast(expr, parse_expr):
     expr = expr.strip()
 
-    and_split = expr.split("&&", 1)
+    comma_split = expr.split(",", 1)
     or_split = expr.split("||", 1)
-    if len(and_split) > 1 and not "||" in and_split[0]:
-        return ASTNode(ASTAction.AND, parse_ast(and_split[0], parse_expr), parse_ast(and_split[1], parse_expr))
+    if len(comma_split) > 1 and not "||" in comma_split[0]:
+        return ASTNode(ASTAction.OR, parse_ast(comma_split[0], parse_expr), parse_ast(comma_split[1], parse_expr))
     if len(or_split) > 1:
-        assert not "&&" in or_split[0]
+        assert not "," in or_split[0]
         return ASTNode(ASTAction.OR, parse_ast(or_split[0], parse_expr), parse_ast(or_split[1], parse_expr))
 
-    comma_split = expr.split(",", 1)
-    if len(comma_split) > 1:
-        return ASTNode(ASTAction.OR, parse_ast(comma_split[0], parse_expr), parse_ast(comma_split[1], parse_expr))
+    and_split = expr.split("&&", 1)
+    if len(and_split) > 1:
+        return ASTNode(ASTAction.AND, parse_ast(and_split[0], parse_expr), parse_ast(and_split[1], parse_expr))
+
+    if expr.strip() == "true":
+        return ASTNode(ASTAction.TRUE, None)
+    if expr.strip() == "false":
+        return ASTNode(ASTAction.FALSE, None)
 
     if expr.startswith("!"):
         return ASTNode(ASTAction.NOT, parse_ast(expr[1:], parse_expr))
@@ -218,10 +232,10 @@ def dscp_to_rule(proto, rules):
 def port_to_rule(ty, rules):
     if ty == "port" :
         ast = parse_ast(rules, parse_numbers_expr)
-        return "if (tcp == NULL && udp == NULL) break;\nif (!( " + ast.write("sport", "dport") + " )) break;"
+        return "if (!ports_valid) break;\nif (!( " + ast.write("sport", "dport") + " )) break;"
 
     ast = parse_ast(rules, parse_numbers_expr)
-    return "if (tcp == NULL && udp == NULL) break;\nif (!( " + ast.write(ty) + " )) break;"
+    return "if (!ports_valid) break;\nif (!( " + ast.write(ty) + " )) break;"
 
 def tcp_flags_to_rule(rules):
     ast = parse_ast(rules, parse_bit_expr)
@@ -269,33 +283,31 @@ with open("rules.h", "w") as out:
             assert False
         out.write("#define REQ_8021Q " + args.vlan_tag + "\n")
 
-    use_v4 = False
-    use_v6 = False
+    rules6 = ""
+    rules4 = ""
     use_v6_frags = False
     rulecnt = 0
 
-    out.write("#define RULES \\\n")
-
-    def write_rule(r):
-        out.write("\t\t" + r.replace("\n", " \\\n\t\t") + " \\\n")
-
     for line in sys.stdin.readlines():
         t = line.split("{")
         if len(t) != 2:
             continue
         if t[0].strip() == "flow4":
             proto = 4
-            use_v4 = True
-            out.write("if (eth_proto == htons(ETH_P_IP)) { \\\n")
-            out.write("\tdo {\\\n")
+            rules4 += "\tdo {\\\n"
         elif t[0].strip() == "flow6":
             proto = 6
-            use_v6 = True
-            out.write("if (eth_proto == htons(ETH_P_IPV6)) { \\\n")
-            out.write("\tdo {\\\n")
+            rules6 += "\tdo {\\\n"
         else:
             continue
 
+        def write_rule(r):
+            global rules4, rules6
+            if proto == 6:
+                rules6 += "\t\t" + r.replace("\n", " \\\n\t\t") + " \\\n"
+            else:
+                rules4 += "\t\t" + r.replace("\n", " \\\n\t\t") + " \\\n"
+
         rule = t[1].split("}")[0].strip()
         for step in rule.split(";"):
             if step.strip().startswith("src") or step.strip().startswith("dst"):
@@ -335,17 +347,22 @@ with open("rules.h", "w") as out:
                 pass
             else:
                 assert False
-        out.write(f"\t\tconst uint32_t ruleidx = STATIC_RULE_CNT + {rulecnt};\\\n")
-        out.write("\t\tDO_RETURN(ruleidx, XDP_DROP);\\\n")
-        out.write("\t} while(0);\\\n}\\\n")
+        write_rule(f"const uint32_t ruleidx = STATIC_RULE_CNT + {rulecnt};")
+        write_rule("DO_RETURN(ruleidx, XDP_DROP);")
+        if proto == 6:
+            rules6 += "\t} while(0);\\\n"
+        else:
+            rules4 += "\t} while(0);\\\n"
         rulecnt += 1
 
     out.write("\n")
     out.write(f"#define RULECNT {rulecnt}\n")
-    if use_v4:
+    if rules4 != "":
         out.write("#define NEED_V4_PARSE\n")
-    if use_v6:
+        out.write("#define RULES4 {\\\n" + rules4 + "}\n")
+    if rules6:
         out.write("#define NEED_V6_PARSE\n")
+        out.write("#define RULES6 {\\\n" + rules6 + "}\n")
     if args.v6frag == "ignore-parse-if-rule":
         if use_v6_frags:
             out.write("#define PARSE_V6_FRAG PARSE\n")