if self.action == ASTAction.EXPR:
return self.left.write(expr_param, expr_param2)
-def parse_ast(expr, parse_expr):
+def parse_ast(expr, parse_expr, comma_is_or):
expr = expr.strip()
comma_split = expr.split(",", 1)
or_split = expr.split("||", 1)
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))
+ # Confusingly, BIRD uses `,` as either || or &&, depending on the type
+ # of expression being parsed. Specifically, a `numbers-match` uses `,`
+ # as OR, whereas a `bitmask-match` uses `,` as AND.
+ if comma_is_or:
+ return ASTNode(ASTAction.OR, parse_ast(comma_split[0], parse_expr, comma_is_or), parse_ast(comma_split[1], parse_expr, comma_is_or))
+ else:
+ return ASTNode(ASTAction.AND, parse_ast(comma_split[0], parse_expr, comma_is_or), parse_ast(comma_split[1], parse_expr, comma_is_or))
if len(or_split) > 1:
assert not "," in or_split[0]
- return ASTNode(ASTAction.OR, parse_ast(or_split[0], parse_expr), parse_ast(or_split[1], parse_expr))
+ return ASTNode(ASTAction.OR, parse_ast(or_split[0], parse_expr, comma_is_or), parse_ast(or_split[1], parse_expr, comma_is_or))
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))
+ return ASTNode(ASTAction.AND, parse_ast(and_split[0], parse_expr, comma_is_or), parse_ast(and_split[1], parse_expr, comma_is_or))
if expr.strip() == "true":
return ASTNode(ASTAction.TRUE, None)
return ASTNode(ASTAction.FALSE, None)
if expr.startswith("!"):
- return ASTNode(ASTAction.NOT, parse_ast(expr[1:], parse_expr))
+ return ASTNode(ASTAction.NOT, parse_ast(expr[1:], parse_expr, comma_is_or))
return parse_expr(expr)
break;"""
def fragment_to_rule(ipproto, rules):
- ast = parse_ast(rules, parse_frag_expr)
+ ast = parse_ast(rules, parse_frag_expr, False)
return "if (!( " + ast.write(ipproto) + " )) break;"
def len_to_rule(rules):
- ast = parse_ast(rules, parse_numbers_expr)
+ ast = parse_ast(rules, parse_numbers_expr, True)
return "if (!( " + ast.write("(data_end - pktdata)") + " )) break;"
def proto_to_rule(ipproto, proto):
- ast = parse_ast(proto, parse_numbers_expr)
+ ast = parse_ast(proto, parse_numbers_expr, True)
if ipproto == 4:
return "if (!( " + ast.write("ip->protocol") + " )) break;"
return "if (!( " + ast.write("ip6->nexthdr") + " )) break;"
def icmp_type_to_rule(proto, ty):
- ast = parse_ast(ty, parse_numbers_expr)
+ ast = parse_ast(ty, parse_numbers_expr, True)
if proto == 4:
return "if (icmp == NULL) break;\nif (!( " + ast.write("icmp->type") + " )) break;"
else:
return "if (icmpv6 == NULL) break;\nif (!( " + ast.write("icmpv6->icmp6_type") + " )) break;"
def icmp_code_to_rule(proto, code):
- ast = parse_ast(code, parse_numbers_expr)
+ ast = parse_ast(code, parse_numbers_expr, True)
if proto == 4:
return "if (icmp == NULL) break;\nif (!( " + ast.write("icmp->code") + " )) break;"
else:
return "if (icmpv6 == NULL) break;\nif (!( " + ast.write("icmpv6->icmp6_code") + " )) break;"
def dscp_to_rule(proto, rules):
- ast = parse_ast(rules, parse_numbers_expr)
+ ast = parse_ast(rules, parse_numbers_expr, True)
if proto == 4:
return "if (!( " + ast.write("((ip->tos & 0xfc) >> 2)") + " )) break;"
def port_to_rule(ty, rules):
if ty == "port" :
- ast = parse_ast(rules, parse_numbers_expr)
- return "if (!ports_valid) break;\nif (!( " + ast.write("sport", "dport") + " )) break;"
+ ast = parse_ast(rules, parse_numbers_expr, True)
+ return "if (sport == -1 || dport == -1) break;\nif (!( " + ast.write("sport", "dport") + " )) break;"
- ast = parse_ast(rules, parse_numbers_expr)
- return "if (!ports_valid) break;\nif (!( " + ast.write(ty) + " )) break;"
+ ast = parse_ast(rules, parse_numbers_expr, True)
+ return "if (" + ty + " == -1) break;\nif (!( " + ast.write(ty) + " )) break;"
def tcp_flags_to_rule(rules):
- ast = parse_ast(rules, parse_bit_expr)
+ ast = parse_ast(rules, parse_bit_expr, False)
return f"""if (tcp == NULL) break;
if (!( {ast.write("(ntohs(tcp->flags) & 0xfff)")} )) break;"""
def flow_label_to_rule(rules):
- ast = parse_ast(rules, parse_bit_expr)
+ ast = parse_ast(rules, parse_bit_expr, False)
return f"""if (ip6 == NULL) break;
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;"""
use_v6_frags = False
rulecnt = 0
ratelimitcnt = 0
- v4persrcratelimitcnt = 0
- v6persrcratelimitcnt = 0
+ v4persrcratelimits = []
+ v6persrcratelimits = []
lastrule = None
for line in sys.stdin.readlines():
# Now write the match handling!
first_action = None
+ stats_action = None
last_action = None
for community in line.split("("):
if not community.startswith("generic, "):
if len(blocks[1].strip()) != 10: # Should be 0x12345678
continue
ty = blocks[1].strip()[:6]
- high_byte = int(blocks[1].strip()[8:], 16)
+ high_byte = int(blocks[1].strip()[6:8], 16)
+ mid_byte = int(blocks[1].strip()[8:], 16)
low_bytes = int(blocks[2].strip(") \n"), 16)
if ty == "0x8006" or ty == "0x800c" or ty == "0x8306" or ty == "0x830c":
if first_action is not None:
first_action = None
exp = (low_bytes & (0xff << 23)) >> 23
if low_bytes == 0:
- first_action = "return XDP_DROP;"
+ first_action = "{stats_replace}\nreturn XDP_DROP;"
elif low_bytes & (1 << 31) != 0:
# Negative limit, just drop
- first_action = "return XDP_DROP;"
+ first_action = "{stats_replace}\nreturn XDP_DROP;"
elif exp == 0xff:
# NaN/INF. Just treat as INF and accept
first_action = None
elif exp <= 127: # < 1
- first_action = "return XDP_DROP;"
+ first_action = "{stats_replace}\nreturn XDP_DROP;"
elif exp >= 127 + 63: # The count won't even fit in 64-bits, just accept
first_action = None
else:
spin_lock = "/* No locking as we're per-CPU */"
spin_unlock = "/* No locking as we're per-CPU */"
if proto == 4:
- if high_byte > 32:
+ if mid_byte > 32:
continue
- first_action += f"const uint32_t srcip = ip->saddr & MASK4({high_byte});\n"
- first_action += f"void *rate_map = &v4_src_rate_{v4persrcratelimitcnt};\n"
- v4persrcratelimitcnt += 1
+ first_action += f"const uint32_t srcip = ip->saddr & MASK4({mid_byte});\n"
+ first_action += f"void *rate_map = &v4_src_rate_{len(v4persrcratelimits)};\n"
+ v4persrcratelimits.append((high_byte + 1) * 1024)
else:
- if high_byte > 128:
+ if mid_byte > 128:
continue
- first_action += f"const uint128_t srcip = ip6->saddr & MASK6({high_byte});\n"
- first_action += f"void *rate_map = &v6_src_rate_{v6persrcratelimitcnt};\n"
- v6persrcratelimitcnt += 1
+ first_action += f"const uint128_t srcip = ip6->saddr & MASK6({mid_byte});\n"
+ first_action += f"void *rate_map = &v6_src_rate_{len(v6persrcratelimits)};\n"
+ v6persrcratelimits.append((high_byte + 1) * 1024)
first_action += f"struct percpu_ratelimit *rate = bpf_map_lookup_elem(rate_map, &srcip);\n"
first_action += "if (rate) {\n"
first_action += f"\t{spin_lock}\n"
first_action += f"\t\t{spin_unlock}\n"
first_action += "\t} else {\n"
first_action += f"\t\t{spin_unlock}\n"
+ first_action += "\t\t{stats_replace}\n"
first_action += "\t\treturn XDP_DROP;\n"
first_action += "\t}\n"
if ty == "0x8306" or ty == "0x830c":
if low_bytes & 1 == 0:
last_action = "return XDP_PASS;"
if low_bytes & 2 == 2:
- write_rule(f"const uint32_t ruleidx = STATIC_RULE_CNT + {rulecnt};")
- write_rule("INCREMENT_MATCH(ruleidx);")
+ stats_action = f"const uint32_t ruleidx = STATIC_RULE_CNT + {rulecnt};\n"
+ stats_action += "INCREMENT_MATCH(ruleidx);"
elif ty == "0x8008":
assert False # We do not implement the redirect action
elif ty == "0x8009":
write_rule("ip6->priority = " + str(low_bytes >> 2) + ";")
write_rule("ip6->flow_lbl[0] = (ip6->flow_lbl[0] & 0x3f) | " + str((low_bytes & 3) << 6) + ";")
if first_action is not None:
- write_rule(first_action)
+ write_rule(first_action.replace("{stats_replace}", stats_action))
+ if stats_action is not None and (first_action is None or "{stats_replace}" not in first_action):
+ write_rule(stats_action)
if last_action is not None:
write_rule(last_action)
if proto == 6:
out.write(f"#define RULECNT {rulecnt}\n")
if ratelimitcnt != 0:
out.write(f"#define RATE_CNT {ratelimitcnt}\n")
- if v4persrcratelimitcnt != 0:
- out.write(f"#define V4_SRC_RATE_CNT {v4persrcratelimitcnt}\n")
- if v6persrcratelimitcnt != 0:
- out.write(f"#define V6_SRC_RATE_CNT {v6persrcratelimitcnt}\n")
if rules4 != "":
out.write("#define NEED_V4_PARSE\n")
out.write("#define RULES4 {\\\n" + rules4 + "}\n")
if args.v6frag == "ignore-parse-if-rule":
if use_v6_frags:
out.write("#define PARSE_V6_FRAG PARSE\n")
+ with open("maps.h", "w") as out:
+ for idx, limit in enumerate(v4persrcratelimits):
+ out.write(f"V4_SRC_RATE_DEFINE({idx}, {limit})\n")
+ for idx, limit in enumerate(v6persrcratelimits):
+ out.write(f"V6_SRC_RATE_DEFINE({idx}, {limit})\n")
projects / flowspec-xdp / blobdiff