import sys
import ipaddress
from enum import Enum
+import argparse
+
IP_PROTO_ICMP = 1
IP_PROTO_ICMPV6 = 58
IP_PROTO_TCP = 6
IP_PROTO_UDP = 17
-if len(sys.argv) > 2 and sys.argv[2].startswith("parse_ihl"):
- PARSE_IHL = True
-else:
- PARSE_IHL = False
-if len(sys.argv) > 3 and sys.argv[3].startswith("parse_exthdr"):
- PARSE_EXTHDR = True
-else:
- PARSE_EXTHDR = False
-
-
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
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))
expr = expr[2:]
return ASTNode(ASTAction.EXPR, NumbersExpr(NumbersAction.EQ, expr))
-class FragExpr:
- def __init__(self, val):
- if val == "is_fragment":
- self.rule = "(ip->frag_off & BE16(IP_MF|IP_OFFSET)) != 0"
- elif val == "first_fragment":
- self.rule = "(ip->frag_off & BE16(IP_MF)) != 0 && (ip->frag_off & BE16(IP_OFFSET)) == 0"
- elif val == "dont_fragment":
- self.rule = "(ip->frag_off & BE16(IP_DF)) != 0"
- elif val == "last_fragment":
- self.rule = "(ip->frag_off & BE16(IP_MF)) == 0 && (ip->frag_off & BE16(IP_OFFSET)) != 0"
+class FragExpr(Enum):
+ IF = 1
+ FF = 2
+ DF = 3
+ LF = 4
+
+ def write(self, ipproto, _param2):
+ if ipproto == 4:
+ if self == FragExpr.IF:
+ return "(ip->frag_off & BE16(IP_MF|IP_OFFSET)) != 0"
+ elif self == FragExpr.FF:
+ return "((ip->frag_off & BE16(IP_MF)) != 0 && (ip->frag_off & BE16(IP_OFFSET)) == 0)"
+ elif self == FragExpr.DF:
+ return "(ip->frag_off & BE16(IP_DF)) != 0"
+ elif self == FragExpr.LF:
+ return "((ip->frag_off & BE16(IP_MF)) == 0 && (ip->frag_off & BE16(IP_OFFSET)) != 0)"
+ else:
+ assert False
else:
- assert False
-
- def write(self, _param, _param2):
- return self.rule
+ if self == FragExpr.IF:
+ return "frag6 != NULL"
+ elif self == FragExpr.FF:
+ return "(frag6 != NULL && (frag6->frag_off & BE16(IP6_MF)) != 0 && (frag6->frag_off & BE16(IP6_FRAGOFF)) == 0)"
+ elif self == FragExpr.DF:
+ assert False # No such thing in v6
+ elif self == FragExpr.LF:
+ return "(frag6 != NULL && (frag6->frag_off & BE16(IP6_MF)) == 0 && (frag6->frag_off & BE16(IP6_FRAGOFF)) != 0)"
+ else:
+ assert False
def parse_frag_expr(expr):
- return ASTNode(ASTAction.EXPR, FragExpr(expr))
+ if expr == "is_fragment":
+ return ASTNode(ASTAction.EXPR, FragExpr.IF)
+ elif expr == "first_fragment":
+ return ASTNode(ASTAction.EXPR, FragExpr.FF)
+ elif expr == "dont_fragment":
+ return ASTNode(ASTAction.EXPR, FragExpr.DF)
+ elif expr == "last_fragment":
+ return ASTNode(ASTAction.EXPR, FragExpr.LF)
+ else:
+ assert False
class BitExpr:
def __init__(self, val):
break;"""
def fragment_to_rule(ipproto, rules):
- if ipproto == 6:
- assert False # XXX: unimplemented
ast = parse_ast(rules, parse_frag_expr)
- return "if (!( " + ast.write(()) + " )) break;"
+ return "if (!( " + ast.write(ipproto) + " )) break;"
def len_to_rule(rules):
ast = parse_ast(rules, parse_numbers_expr)
if ipproto == 4:
return "if (!( " + ast.write("ip->protocol") + " )) break;"
else:
- if PARSE_EXTHDR:
- assert False # XXX: unimplemented
return "if (!( " + ast.write("ip6->nexthdr") + " )) break;"
def icmp_type_to_rule(proto, ty):
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)
if (!( {ast.write("((((uint32_t)(ip6->flow_lbl[0] & 0xf)) << 2*8) | (((uint32_t)ip6->flow_lbl[1]) << 1*8) | (uint32_t)ip6->flow_lbl[0])")} )) break;"""
with open("rules.h", "w") as out:
- if len(sys.argv) > 1 and sys.argv[1] == "parse_8021q":
- out.write("#define PARSE_8021Q\n")
- if len(sys.argv) > 1 and sys.argv[1].startswith("req_8021q="):
- out.write("#define PARSE_8021Q\n")
- out.write(f"#define REQ_8021Q {sys.argv[1][10:]}\n")
-
-
- out.write("#define RULES \\\n")
+ parse = argparse.ArgumentParser()
+ parse.add_argument("--ihl", dest="ihl", required=True, choices=["drop-options","accept-options","parse-options"])
+ parse.add_argument("--v6frag", dest="v6frag", required=True, choices=["drop-frags","ignore","parse-frags","ignore-parse-if-rule"])
+ parse.add_argument("--8021q", dest="vlan", required=True, choices=["drop-vlan","accept-vlan","parse-vlan"])
+ parse.add_argument("--require-8021q", dest="vlan_tag")
+ args = parse.parse_args(sys.argv[1:])
+
+ if args.ihl == "drop-options":
+ out.write("#define PARSE_IHL XDP_DROP\n")
+ elif args.ihl == "accept-options":
+ out.write("#define PARSE_IHL XDP_PASS\n")
+ elif args.ihl == "parse-options":
+ out.write("#define PARSE_IHL PARSE\n")
+
+ if args.v6frag == "drop-frags":
+ out.write("#define PARSE_V6_FRAG XDP_DROP\n")
+ elif args.v6frag == "ignore":
+ pass
+ elif args.v6frag == "parse-frags":
+ out.write("#define PARSE_V6_FRAG PARSE\n")
+
+ if args.vlan == "drop-vlan":
+ out.write("#define PARSE_8021Q XDP_DROP\n")
+ elif args.vlan == "accept-vlan":
+ out.write("#define PARSE_8021Q XDP_PASS\n")
+ elif args.vlan == "parse-vlan":
+ out.write("#define PARSE_8021Q PARSE\n")
+
+ if args.vlan_tag is not None:
+ if args.vlan != "parse-vlan":
+ assert False
+ out.write("#define REQ_8021Q " + args.vlan_tag + "\n")
- def write_rule(r):
- out.write("\t\t" + r.replace("\n", " \\\n\t\t") + " \\\n")
+ rules6 = ""
+ rules4 = ""
+ use_v6_frags = False
+ rulecnt = 0
for line in sys.stdin.readlines():
t = line.split("{")
continue
if t[0].strip() == "flow4":
proto = 4
- out.write("if (eth_proto == htons(ETH_P_IP)) { \\\n")
- out.write("\tdo {\\\n")
+ rules4 += "\tdo {\\\n"
elif t[0].strip() == "flow6":
proto = 6
- 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"):
elif step.strip().startswith("label"):
write_rule(flow_label_to_rule(step.strip()[6:]))
elif step.strip().startswith("fragment"):
+ if proto == 6:
+ use_v6_frags = True
write_rule(fragment_to_rule(proto, step.strip()[9:]))
elif step.strip() == "":
pass
else:
assert False
- out.write("\t\treturn 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 rules4 != "":
+ out.write("#define NEED_V4_PARSE\n")
+ 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")
projects / flowspec-xdp / blobdiff