From 348583843f9499b0f1c335edc684a077bb2c2710 Mon Sep 17 00:00:00 2001 From: Matt Corallo Date: Mon, 5 Apr 2021 19:30:55 -0400 Subject: [PATCH] Implement (only manually-tested) flowspec community detection except ratelimit --- genrules.py | 170 +++++++++++++++++++++++++++++++++------------------- install.sh | 4 +- test.sh | 104 ++++++++++++++++---------------- xdp.c | 41 +++++++------ 4 files changed, 186 insertions(+), 133 deletions(-) diff --git a/genrules.py b/genrules.py index 480e628..51e547d 100755 --- a/genrules.py +++ b/genrules.py @@ -249,6 +249,7 @@ def flow_label_to_rule(rules): 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;""" + with open("rules.h", "w") as out: parse = argparse.ArgumentParser() parse.add_argument("--ihl", dest="ihl", required=True, choices=["drop-options","accept-options","parse-options"]) @@ -288,72 +289,121 @@ with open("rules.h", "w") as out: use_v6_frags = False rulecnt = 0 + lastrule = None for line in sys.stdin.readlines(): - t = line.split("{") - if len(t) != 2: - continue - if t[0].strip() == "flow4": - proto = 4 - rules4 += "\tdo {\\\n" - elif t[0].strip() == "flow6": - proto = 6 - rules6 += "\tdo {\\\n" - else: + if "{" in line: + if lastrule is not None: + print("Skipped rule due to lack of understood community tag: " + lastrule) + lastrule = line continue - - def write_rule(r): - global rules4, rules6 - if proto == 6: - rules6 += "\t\t" + r.replace("\n", " \\\n\t\t") + " \\\n" + if "BGP.ext_community: " in line: + assert lastrule is not None + + t = lastrule.split("{") + if t[0].strip() == "flow4": + proto = 4 + rules4 += "\tdo {\\\n" + elif t[0].strip() == "flow6": + proto = 6 + rules6 += "\tdo {\\\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"): - nets = step.strip()[3:].strip().split(" ") - if len(nets) > 1: - assert nets[1] == "offset" - offset = nets[2] + continue + + def write_rule(r): + global rules4, rules6 + if proto == 6: + rules6 += "\t\t" + r.replace("\n", " \\\n\t\t") + " \\\n" else: - offset = None - if step.strip().startswith("src"): - write_rule(ip_to_rule(proto, nets[0], "saddr", offset)) + 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"): + nets = step.strip()[3:].strip().split(" ") + if len(nets) > 1: + assert nets[1] == "offset" + offset = nets[2] + else: + offset = None + if step.strip().startswith("src"): + write_rule(ip_to_rule(proto, nets[0], "saddr", offset)) + else: + write_rule(ip_to_rule(proto, nets[0], "daddr", offset)) + elif step.strip().startswith("proto") and proto == 4: + write_rule(proto_to_rule(4, step.strip()[6:])) + elif step.strip().startswith("next header") and proto == 6: + write_rule(proto_to_rule(6, step.strip()[12:])) + elif step.strip().startswith("icmp type"): + write_rule(icmp_type_to_rule(proto, step.strip()[10:])) + elif step.strip().startswith("icmp code"): + write_rule(icmp_code_to_rule(proto, step.strip()[10:])) + elif step.strip().startswith("sport") or step.strip().startswith("dport") or step.strip().startswith("port"): + write_rule(port_to_rule(step.strip().split(" ")[0], step.strip().split(" ", 1)[1])) + elif step.strip().startswith("length"): + write_rule(len_to_rule(step.strip()[7:])) + elif step.strip().startswith("dscp"): + write_rule(dscp_to_rule(proto, step.strip()[5:])) + elif step.strip().startswith("tcp flags"): + write_rule(tcp_flags_to_rule(step.strip()[10:])) + 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: - write_rule(ip_to_rule(proto, nets[0], "daddr", offset)) - elif step.strip().startswith("proto") and proto == 4: - write_rule(proto_to_rule(4, step.strip()[6:])) - elif step.strip().startswith("next header") and proto == 6: - write_rule(proto_to_rule(6, step.strip()[12:])) - elif step.strip().startswith("icmp type"): - write_rule(icmp_type_to_rule(proto, step.strip()[10:])) - elif step.strip().startswith("icmp code"): - write_rule(icmp_code_to_rule(proto, step.strip()[10:])) - elif step.strip().startswith("sport") or step.strip().startswith("dport") or step.strip().startswith("port"): - write_rule(port_to_rule(step.strip().split(" ")[0], step.strip().split(" ", 1)[1])) - elif step.strip().startswith("length"): - write_rule(len_to_rule(step.strip()[7:])) - elif step.strip().startswith("dscp"): - write_rule(dscp_to_rule(proto, step.strip()[5:])) - elif step.strip().startswith("tcp flags"): - write_rule(tcp_flags_to_rule(step.strip()[10:])) - 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 + assert False + + # Now write the match handling! + first_action = None + last_action = None + for community in line.split("("): + if not community.startswith("generic, "): + continue + blocks = community.split(",") + assert len(blocks) == 3 + if len(blocks[1].strip()) != 10: # Should be 0x12345678 + continue + ty = blocks[1].strip()[:6] + low_bytes = int(blocks[2].strip(") \n"), 16) + if ty == "0x8006": + if low_bytes == 0: + first_action = "return XDP_DROP;" + else: + assert False # Not yet supported + elif ty == "0x8007": + 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);") + elif ty == "0x8008": + assert False # We do not implement the redirect action + elif ty == "0x8009": + if low_bytes & ~0b111111 != 0: + assert False # Invalid DSCP value + if proto == 4: + write_rule("int32_t chk = ~BE16(ip->check) & 0xffff;") + write_rule("uint8_t orig_tos = ip->tos;") + write_rule("ip->tos = (ip->tos & 3) | " + str(low_bytes << 2) + ";") + write_rule("chk = (chk - orig_tos + ip->tos);") + write_rule("if (unlikely(chk < 0)) { chk += 65534; }") + write_rule("ip->check = ~BE16(chk);") + else: + 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) + if last_action is not None: + write_rule(last_action) + if proto == 6: + rules6 += "\t} while(0);\\\n" else: - assert False - 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 + rules4 += "\t} while(0);\\\n" + rulecnt += 1 + lastrule = None out.write("\n") out.write(f"#define RULECNT {rulecnt}\n") diff --git a/install.sh b/install.sh index 97df120..af9a3ed 100755 --- a/install.sh +++ b/install.sh @@ -1,8 +1,8 @@ #!/bin/bash set -e -RULES="$(birdc show route table flowspec4) -$(birdc show route table flowspec6)" +RULES="$(birdc show route table flowspec4 primary all) +$(birdc show route table flowspec6 primary all)" echo "$RULES" | ./genrules.py --8021q=drop-vlan --v6frag=ignore-parse-if-rule --ihl=drop-options clang -std=c99 -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O3 -emit-llvm -c xdp.c -o - | llc -O3 -march=bpf -filetype=obj -o xdp diff --git a/test.sh b/test.sh index 850ab36..d9aa68a 100755 --- a/test.sh +++ b/test.sh @@ -2,6 +2,10 @@ set -e +COMMUNITY_DROP=" + Type: static univ + BGP.ext_community: (generic, 0x80060000, 0x0) (generic, 0x80070000, 0xf) (generic, 0x80090000, 0x3f)" + TEST_PKT='#define TEST \ "\x00\x17\x10\x95\xe8\x96\x00\x0d\xb9\x50\x11\x4c\x08\x00\x45\x00" \ "\x00\x8c\x7d\x0f\x00\x00\x40\x11\x3a\x31\x48\xe5\x68\xce\x67\x63" \ @@ -15,70 +19,70 @@ TEST_PKT='#define TEST \ "\xb5\xc3\xa9\xa6\x21\x14\xc7\xd9\x71\x07"' # Test all the things... -echo "flow4 { src 72.229.104.206/32; dst 103.99.170.10/32; proto = 17; sport = 56733; dport = 4242; length = 140; dscp = 0; fragment !dont_fragment && !is_fragment && !first_fragment && !last_fragment };" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore +echo "flow4 { src 72.229.104.206/32; dst 103.99.170.10/32; proto = 17; sport = 56733; dport = 4242; length = 140; dscp = 0; fragment !dont_fragment && !is_fragment && !first_fragment && !last_fragment };$COMMUNITY_DROP" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_DROP" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow4 { port = 4242; icmp code = 0; };" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=drop-frags +echo "flow4 { port = 4242; icmp code = 0; };$COMMUNITY_DROP" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=drop-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_PASS" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp # Some port tests... -echo "flow4 { port = 4242 && = 56733; };" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore +echo "flow4 { port = 4242 && = 56733; };$COMMUNITY_DROP" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_DROP" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow4 { port = 4242 || 1; sport = 56733 };" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore +echo "flow4 { port = 4242 || 1; sport = 56733 };$COMMUNITY_DROP" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_DROP" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow4 { port = 4242 && 1 };" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=drop-frags +echo "flow4 { port = 4242 && 1 };$COMMUNITY_DROP" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=drop-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_PASS" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp # Some match-order tests... # (43 && 42) || 4242 -echo "flow4 { port = 43 && 42, 4242; };" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore +echo "flow4 { port = 43 && 42, 4242; };$COMMUNITY_DROP" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_DROP" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp # (43 && 42) || 4242 -echo "flow4 { port = 43 && 42 || 4242; };" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore +echo "flow4 { port = 43 && 42 || 4242; };$COMMUNITY_DROP" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_DROP" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp # 4242 || (42 && 43) -echo "flow4 { port = 4242, 42 && 43; };" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore +echo "flow4 { port = 4242, 42 && 43; };$COMMUNITY_DROP" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_DROP" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp # (4242 && false) || (42 && 4242) -echo "flow4 { port = 4242 && false, 42 && 4242; };" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore +echo "flow4 { port = 4242 && false, 42 && 4242; };$COMMUNITY_DROP" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_PASS" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp # (4242 && true) || (42 && 43) -echo "flow4 { port = 4242 && true, 42 && 43; };" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore +echo "flow4 { port = 4242 && true, 42 && 43; };$COMMUNITY_DROP" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_DROP" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp # 42 || true -echo "flow4 { port = 42, true; };" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore +echo "flow4 { port = 42, true; };$COMMUNITY_DROP" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_DROP" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow4 { icmp code != 0; };" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=drop-frags +echo "flow4 { icmp code != 0; };$COMMUNITY_DROP" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=drop-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_PASS" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp @@ -92,22 +96,22 @@ TEST_PKT='#define TEST \ "\x75\xde\xeb\x22\xd6\x80"' # Some v6 TCP tests with a DSCP of all 1s... -echo "flow6 { src 2a01:4f8:130:71d2::2/128; dst 2620:6e:a000:2001::6/128; next header 6; port 8333 && 49778; tcp flags 0x010/0xfff;};" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore +echo "flow6 { src 2a01:4f8:130:71d2::2/128; dst 2620:6e:a000:2001::6/128; next header 6; port 8333 && 49778; tcp flags 0x010/0xfff;};$COMMUNITY_DROP" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_DROP" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow6 { src 0:4f8:130:71d2::2/128 offset 16; dst 0:0:a000:2001::/64 offset 32; next header 6; port 8333 && 49778; tcp flags 0x010/0xfff;};" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore +echo "flow6 { src 0:4f8:130:71d2::2/128 offset 16; dst 0:0:a000:2001::/64 offset 32; next header 6; port 8333 && 49778; tcp flags 0x010/0xfff;};$COMMUNITY_DROP" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_DROP" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow6 { dscp 0x3f; };" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=drop-frags +echo "flow6 { dscp 0x3f; };$COMMUNITY_DROP" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=drop-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_DROP" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow6 { icmp code != 0; };" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=drop-frags +echo "flow6 { icmp code != 0; };$COMMUNITY_DROP" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=drop-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_PASS" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp @@ -122,54 +126,54 @@ TEST_PKT='#define TEST \ "\x32\x33\x34\x35\x36\x37"' # ICMP and VLAN tests with DSCP of all 1s... -echo "flow4 { src 10.0.0.0/8; dst 209.250.0.0/16; proto = 1; icmp type 8; icmp code >= 0; length < 100; fragment dont_fragment; };" | ./genrules.py --ihl=accept-options --8021q=parse-vlan --v6frag=ignore +echo "flow4 { src 10.0.0.0/8; dst 209.250.0.0/16; proto = 1; icmp type 8; icmp code >= 0; length < 100; fragment dont_fragment; };$COMMUNITY_DROP" | ./genrules.py --ihl=accept-options --8021q=parse-vlan --v6frag=ignore echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_DROP" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow4 { icmp type 8; icmp code > 0; };" | ./genrules.py --ihl=drop-options --8021q=parse-vlan --v6frag=drop-frags +echo "flow4 { icmp type 8; icmp code > 0; };$COMMUNITY_DROP" | ./genrules.py --ihl=drop-options --8021q=parse-vlan --v6frag=drop-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_PASS" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow4 { icmp type 9; };" | ./genrules.py --ihl=drop-options --8021q=parse-vlan --v6frag=drop-frags +echo "flow4 { icmp type 9; };$COMMUNITY_DROP" | ./genrules.py --ihl=drop-options --8021q=parse-vlan --v6frag=drop-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_PASS" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow4 { src 10.0.0.0/8; dst 209.250.0.0/16; proto = 1; icmp type 8; icmp code >= 0; length < 100; fragment dont_fragment; };" | ./genrules.py --ihl=accept-options --8021q=parse-vlan --require-8021q=3 --v6frag=ignore +echo "flow4 { src 10.0.0.0/8; dst 209.250.0.0/16; proto = 1; icmp type 8; icmp code >= 0; length < 100; fragment dont_fragment; };$COMMUNITY_DROP" | ./genrules.py --ihl=accept-options --8021q=parse-vlan --require-8021q=3 --v6frag=ignore echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_DROP" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow4 { src 0.0.0.0/32; };" | ./genrules.py --ihl=accept-options --8021q=parse-vlan --require-8021q=4 --v6frag=ignore +echo "flow4 { src 0.0.0.0/32; };$COMMUNITY_DROP" | ./genrules.py --ihl=accept-options --8021q=parse-vlan --require-8021q=4 --v6frag=ignore echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_DROP" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow4 { src 0.0.0.0/32; };" | ./genrules.py --ihl=drop-options --8021q=parse-vlan --require-8021q=3 --v6frag=drop-frags +echo "flow4 { src 0.0.0.0/32; };$COMMUNITY_DROP" | ./genrules.py --ihl=drop-options --8021q=parse-vlan --require-8021q=3 --v6frag=drop-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_PASS" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow4 { port 42; };" | ./genrules.py --ihl=drop-options --8021q=parse-vlan --v6frag=drop-frags +echo "flow4 { port 42; };$COMMUNITY_DROP" | ./genrules.py --ihl=drop-options --8021q=parse-vlan --v6frag=drop-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_PASS" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow4 { dscp 0x3f; };" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=drop-frags +echo "flow4 { dscp 0x3f; };$COMMUNITY_DROP" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=drop-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_DROP" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp # Test --8021q option handling -echo "flow4 { port 42; };" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=drop-frags +echo "flow4 { port 42; };$COMMUNITY_DROP" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=drop-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_DROP" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow4 { };" | ./genrules.py --ihl=drop-options --8021q=accept-vlan --v6frag=drop-frags +echo "flow4 { };$COMMUNITY_DROP" | ./genrules.py --ihl=drop-options --8021q=accept-vlan --v6frag=drop-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_PASS" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp @@ -186,27 +190,27 @@ TEST_PKT='#define TEST \ "\x00\x00\x00\x00\x00\x00"' # ICMPv6 tests -echo "flow6 { icmp type 129; icmp code 0; };" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore +echo "flow6 { icmp type 129; icmp code 0; };$COMMUNITY_DROP" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_DROP" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow6 { icmp code != 0; };" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=drop-frags +echo "flow6 { icmp code != 0; };$COMMUNITY_DROP" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=drop-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_PASS" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow6 { tcp flags 0x0/0x0; };" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=drop-frags +echo "flow6 { tcp flags 0x0/0x0; };$COMMUNITY_DROP" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=drop-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_PASS" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow6 { port 42; };" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=drop-frags +echo "flow6 { port 42; };$COMMUNITY_DROP" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=drop-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_PASS" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow6 { fragment is_fragment || first_fragment || last_fragment; };" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=drop-frags +echo "flow6 { fragment is_fragment || first_fragment || last_fragment; };$COMMUNITY_DROP" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=drop-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_PASS" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp @@ -224,50 +228,50 @@ TEST_PKT='#define TEST \ # Last frag ICMPv6 tests -echo "flow6 { src 2620:6e:a007:233::1/128; dst 2001:470:0:503::2/128; fragment is_fragment && !first_fragment && last_fragment; };" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=parse-frags +echo "flow6 { src 2620:6e:a007:233::1/128; dst 2001:470:0:503::2/128; fragment is_fragment && !first_fragment && last_fragment; };$COMMUNITY_DROP" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=parse-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_DROP" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow6 { src 2620:6e:a007:233::1/128; dst 2001:470:0:503::2/128; fragment !is_fragment; };" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=parse-frags +echo "flow6 { src 2620:6e:a007:233::1/128; dst 2001:470:0:503::2/128; fragment !is_fragment; };$COMMUNITY_DROP" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=parse-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_PASS" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow6 { src 2620:6e:a007:233::1/128; dst 2001:470:0:503::2/128; fragment !is_fragment || first_fragment || !last_fragment; };" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=parse-frags +echo "flow6 { src 2620:6e:a007:233::1/128; dst 2001:470:0:503::2/128; fragment !is_fragment || first_fragment || !last_fragment; };$COMMUNITY_DROP" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=parse-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_PASS" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow6 { src 2620:6e:a007:233::1/128; dst 2001:470:0:503::2/128; fragment !is_fragment || first_fragment || !last_fragment; };" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=parse-frags +echo "flow6 { src 2620:6e:a007:233::1/128; dst 2001:470:0:503::2/128; fragment !is_fragment || first_fragment || !last_fragment; };$COMMUNITY_DROP" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=parse-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_PASS" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp # Note on the second fragment we don't know the ICMP header (though < 256 is trivially true) -echo "flow6 { icmp type < 256; };" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=parse-frags +echo "flow6 { icmp type < 256; };$COMMUNITY_DROP" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=parse-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_PASS" >> rules.h -clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp +clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -Wno-tautological-constant-out-of-range-compare -O0 -g xdp.c -o xdp && ./xdp #TODO Is nextheader frag correct to match on here? Should we support matching on any nexthdr? -echo "flow6 { next header 44; };" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=parse-frags +echo "flow6 { next header 44; };$COMMUNITY_DROP" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=parse-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_DROP" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp # Test the --v6frag options (ignore-parse-if-rule is tested below) -echo "flow6 { tcp flags 42/42; };" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=parse-frags +echo "flow6 { tcp flags 42/42; };$COMMUNITY_DROP" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=parse-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_PASS" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow6 { tcp flags 42/42; };" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=drop-frags +echo "flow6 { tcp flags 42/42; };$COMMUNITY_DROP" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=drop-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_DROP" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow6 { tcp flags 42/42; };" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore +echo "flow6 { tcp flags 42/42; };$COMMUNITY_DROP" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_PASS" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp @@ -357,50 +361,50 @@ TEST_PKT='#define TEST \ # First frag ICMPv6 tests -echo "flow6 { src 2620:6e:a007:233::1/128; dst 2001:470:0:503::2/128; fragment is_fragment && first_fragment && !last_fragment; };" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=parse-frags +echo "flow6 { src 2620:6e:a007:233::1/128; dst 2001:470:0:503::2/128; fragment is_fragment && first_fragment && !last_fragment; };$COMMUNITY_DROP" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=parse-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_DROP" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow6 { src 2620:6e:a007:233::1/128; dst 2001:470:0:503::2/128; fragment !is_fragment; };" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=parse-frags +echo "flow6 { src 2620:6e:a007:233::1/128; dst 2001:470:0:503::2/128; fragment !is_fragment; };$COMMUNITY_DROP" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=parse-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_PASS" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow6 { src 2620:6e:a007:233::1/128; dst 2001:470:0:503::2/128; fragment !is_fragment || !first_fragment || last_fragment; };" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=parse-frags +echo "flow6 { src 2620:6e:a007:233::1/128; dst 2001:470:0:503::2/128; fragment !is_fragment || !first_fragment || last_fragment; };$COMMUNITY_DROP" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=parse-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_PASS" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow6 { src 2620:6e:a007:233::1/128; dst 2001:470:0:503::2/128; fragment is_fragment && first_fragment && !last_fragment; icmp code 0; icmp type 128 };" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=parse-frags +echo "flow6 { src 2620:6e:a007:233::1/128; dst 2001:470:0:503::2/128; fragment is_fragment && first_fragment && !last_fragment; icmp code 0; icmp type 128 };$COMMUNITY_DROP" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=parse-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_DROP" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp #TODO Is nextheader frag correct to match on here? Should we support matching on any nexthdr? -echo "flow6 { next header 44; };" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=parse-frags +echo "flow6 { next header 44; };$COMMUNITY_DROP" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=parse-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_DROP" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp #TODO Is nextheader frag correct to match on here? Should we support matching on any nexthdr? -echo "flow6 { next header 58; };" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=parse-frags +echo "flow6 { next header 58; };$COMMUNITY_DROP" | ./genrules.py --ihl=drop-options --8021q=drop-vlan --v6frag=parse-frags echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_PASS" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp # Test accept-parse-if-rule -echo "flow6 { icmp code 0; icmp type 128; };" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore-parse-if-rule +echo "flow6 { icmp code 0; icmp type 128; };$COMMUNITY_DROP" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore-parse-if-rule echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_PASS" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow6 { icmp code 0; icmp type 128; fragment is_fragment; };" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore-parse-if-rule +echo "flow6 { icmp code 0; icmp type 128; fragment is_fragment; };$COMMUNITY_DROP" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore-parse-if-rule echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_DROP" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp -echo "flow6 { icmp code 0; icmp type 128; fragment !is_fragment };" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore-parse-if-rule +echo "flow6 { icmp code 0; icmp type 128; fragment !is_fragment };$COMMUNITY_DROP" | ./genrules.py --ihl=accept-options --8021q=accept-vlan --v6frag=ignore-parse-if-rule echo "$TEST_PKT" >> rules.h echo "#define TEST_EXP XDP_PASS" >> rules.h clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -O0 -g xdp.c -o xdp && ./xdp diff --git a/xdp.c b/xdp.c index 4e4d6c6..3ebec88 100644 --- a/xdp.c +++ b/xdp.c @@ -96,6 +96,7 @@ struct tcphdr { #elif defined(__BIG_ENDIAN) #define BIGEND128(a, b, c, d) ((((uint128_t)a) << 3*32) | (((uint128_t)b) << 2*32) | (((uint128_t)c) << 1*32) | (((uint128_t)d) << 0*32)) #define HTON128(a) (a) +#define BE16(a) ((uint16_t)a) #else #error "Need endian info" #endif @@ -117,6 +118,16 @@ static const uint32_t IHL_DROP = 2; static const uint32_t V6FRAG_DROP = 3; #define STATIC_RULE_CNT 4 +#define DO_RETURN(reason, ret) {\ + if (ret == XDP_DROP) { INCREMENT_MATCH(reason); } \ + return ret; \ + } + +// It seems (based on drop counts) that data_end points to the last byte, not one-past-the-end. +// This feels strange, but some documentation suggests > here as well, so we stick with that. +#define CHECK_LEN(start, struc) \ + if (unlikely((void*)(start) + sizeof(struct struc) > data_end)) DO_RETURN(PKT_LEN_DROP, XDP_DROP); + #ifdef TEST // 64 bit version of xdp_md for testing struct xdp_md { @@ -133,10 +144,7 @@ static const int XDP_PASS = 0; static const int XDP_DROP = 1; static long drop_cnt_map[RULECNT + STATIC_RULE_CNT]; -#define DO_RETURN(reason, ret) { \ - if (ret == XDP_DROP) drop_cnt_map[reason] += 1; \ - return ret; \ - } +#define INCREMENT_MATCH(reason) drop_cnt_map[reason] += 1; #else #include @@ -148,23 +156,14 @@ struct bpf_map_def SEC("maps") drop_cnt_map = { .value_size = sizeof(long), .max_entries = RULECNT + STATIC_RULE_CNT, }; -#define DO_RETURN(reason, ret) {\ - if (ret == XDP_DROP) { \ - long *value = bpf_map_lookup_elem(&drop_cnt_map, &reason); \ - if (value) \ - *value += 1; \ - } \ - return XDP_DROP; \ - } +#define INCREMENT_MATCH(reason) { \ + long *value = bpf_map_lookup_elem(&drop_cnt_map, &reason); \ + if (value) \ + *value += 1; \ +} SEC("xdp_drop") #endif - -// It seems (based on drop counts) that data_end points to the last byte, not one-past-the-end. -// This feels strange, but some documentation suggests > here as well, so we stick with that. -#define CHECK_LEN(start, struc) \ - if (unlikely((void*)(start) + sizeof(struct struc) > data_end)) DO_RETURN(PKT_LEN_DROP, XDP_DROP); - int xdp_drop_prog(struct xdp_md *ctx) { const void *const data_end = (void *)(size_t)ctx->data_end; @@ -210,7 +209,7 @@ int xdp_drop_prog(struct xdp_md *ctx) #ifdef NEED_V4_PARSE if (eth_proto == BE16(ETH_P_IP)) { CHECK_LEN(pktdata, iphdr); - const struct iphdr *ip = (struct iphdr*) pktdata; + struct iphdr *ip = (struct iphdr*) pktdata; #if PARSE_IHL == PARSE if (unlikely(ip->ihl < 5)) DO_RETURN(IHL_DROP, XDP_DROP); @@ -246,7 +245,7 @@ int xdp_drop_prog(struct xdp_md *ctx) #ifdef NEED_V6_PARSE if (eth_proto == BE16(ETH_P_IPV6)) { CHECK_LEN(pktdata, ip6hdr); - const struct ip6hdr *ip6 = (struct ip6hdr*) pktdata; + struct ip6hdr *ip6 = (struct ip6hdr*) pktdata; l4hdr = pktdata + 40; @@ -298,7 +297,7 @@ int xdp_drop_prog(struct xdp_md *ctx) #include #include -const char d[] = TEST; +char d[] = TEST; int main() { struct xdp_md test = { .data = (uint64_t)d, -- 2.39.5