lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-ID: <20231215-tcp-ao-selftests-v1-2-f6c08180b985@arista.com> Date: Fri, 15 Dec 2023 02:36:16 +0000 From: Dmitry Safonov <dima@...sta.com> To: Shuah Khan <shuah@...nel.org>, David Ahern <dsahern@...nel.org>, "David S. Miller" <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>, Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com> Cc: Dmitry Safonov <dima@...sta.com>, Salam Noureddine <noureddine@...sta.com>, Bob Gilligan <gilligan@...sta.com>, linux-kernel@...r.kernel.org, linux-kselftest@...r.kernel.org, netdev@...r.kernel.org, Dmitry Safonov <0x7f454c46@...il.com> Subject: [PATCH 02/12] selftests/net: Verify that TCP-AO complies with ignoring ICMPs Hand-crafted ICMP packets are sent to the server, the server checks for hard/soft errors and fails if any. Expected output for ipv4 version: > # ./icmps-discard_ipv4 > 1..3 > # 3164[lib/setup.c:166] rand seed 1642623745 > TAP version 13 > # 3164[lib/proc.c:207] Snmp6 Ip6InReceives: 0 => 1 > # 3164[lib/proc.c:207] Snmp6 Ip6InNoRoutes: 0 => 1 > # 3164[lib/proc.c:207] Snmp6 Ip6InOctets: 0 => 76 > # 3164[lib/proc.c:207] Snmp6 Ip6InNoECTPkts: 0 => 1 > # 3164[lib/proc.c:207] Tcp InSegs: 2 => 203 > # 3164[lib/proc.c:207] Tcp OutSegs: 1 => 202 > # 3164[lib/proc.c:207] IcmpMsg InType3: 0 => 543 > # 3164[lib/proc.c:207] Icmp InMsgs: 0 => 543 > # 3164[lib/proc.c:207] Icmp InDestUnreachs: 0 => 543 > # 3164[lib/proc.c:207] Ip InReceives: 2 => 746 > # 3164[lib/proc.c:207] Ip InDelivers: 2 => 746 > # 3164[lib/proc.c:207] Ip OutRequests: 1 => 202 > # 3164[lib/proc.c:207] IpExt InOctets: 132 => 61684 > # 3164[lib/proc.c:207] IpExt OutOctets: 68 => 31324 > # 3164[lib/proc.c:207] IpExt InNoECTPkts: 2 => 744 > # 3164[lib/proc.c:207] TcpExt TCPPureAcks: 1 => 2 > # 3164[lib/proc.c:207] TcpExt TCPOrigDataSent: 0 => 200 > # 3164[lib/proc.c:207] TcpExt TCPDelivered: 0 => 199 > # 3164[lib/proc.c:207] TcpExt TCPAOGood: 2 => 203 > # 3164[lib/proc.c:207] TcpExt TCPAODroppedIcmps: 0 => 541 > ok 1 InDestUnreachs delivered 543 > ok 2 Server survived 20000 bytes of traffic > ok 3 ICMPs ignored 541 > # Totals: pass:3 fail:0 xfail:0 xpass:0 skip:0 error:0 Expected output for ipv6 version: > # ./icmps-discard_ipv6 > 1..3 > # 3186[lib/setup.c:166] rand seed 1642623803 > TAP version 13 > # 3186[lib/proc.c:207] Snmp6 Ip6InReceives: 4 => 568 > # 3186[lib/proc.c:207] Snmp6 Ip6InDelivers: 3 => 564 > # 3186[lib/proc.c:207] Snmp6 Ip6OutRequests: 2 => 204 > # 3186[lib/proc.c:207] Snmp6 Ip6InMcastPkts: 1 => 4 > # 3186[lib/proc.c:207] Snmp6 Ip6OutMcastPkts: 0 => 1 > # 3186[lib/proc.c:207] Snmp6 Ip6InOctets: 320 => 70420 > # 3186[lib/proc.c:207] Snmp6 Ip6OutOctets: 160 => 35512 > # 3186[lib/proc.c:207] Snmp6 Ip6InMcastOctets: 72 => 336 > # 3186[lib/proc.c:207] Snmp6 Ip6OutMcastOctets: 0 => 76 > # 3186[lib/proc.c:207] Snmp6 Ip6InNoECTPkts: 4 => 568 > # 3186[lib/proc.c:207] Snmp6 Icmp6InMsgs: 1 => 361 > # 3186[lib/proc.c:207] Snmp6 Icmp6OutMsgs: 1 => 2 > # 3186[lib/proc.c:207] Snmp6 Icmp6InDestUnreachs: 0 => 360 > # 3186[lib/proc.c:207] Snmp6 Icmp6OutMLDv2Reports: 0 => 1 > # 3186[lib/proc.c:207] Snmp6 Icmp6InType1: 0 => 360 > # 3186[lib/proc.c:207] Snmp6 Icmp6OutType143: 0 => 1 > # 3186[lib/proc.c:207] Tcp InSegs: 2 => 203 > # 3186[lib/proc.c:207] Tcp OutSegs: 1 => 202 > # 3186[lib/proc.c:207] TcpExt TCPPureAcks: 1 => 2 > # 3186[lib/proc.c:207] TcpExt TCPOrigDataSent: 0 => 200 > # 3186[lib/proc.c:207] TcpExt TCPDelivered: 0 => 199 > # 3186[lib/proc.c:207] TcpExt TCPAOGood: 2 => 203 > # 3186[lib/proc.c:207] TcpExt TCPAODroppedIcmps: 0 => 360 > ok 1 Icmp6InDestUnreachs delivered 360 > ok 2 Server survived 20000 bytes of traffic > ok 3 ICMPs ignored 360 > # Totals: pass:3 fail:0 xfail:0 xpass:0 skip:0 error:0 Signed-off-by: Dmitry Safonov <dima@...sta.com> --- tools/testing/selftests/net/tcp_ao/Makefile | 1 + tools/testing/selftests/net/tcp_ao/icmps-discard.c | 438 +++++++++++++++++++++ 2 files changed, 439 insertions(+) diff --git a/tools/testing/selftests/net/tcp_ao/Makefile b/tools/testing/selftests/net/tcp_ao/Makefile index 62425b9fb73c..0fc5db59be0c 100644 --- a/tools/testing/selftests/net/tcp_ao/Makefile +++ b/tools/testing/selftests/net/tcp_ao/Makefile @@ -1,5 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 TEST_BOTH_AF := connect +TEST_BOTH_AF += icmps-discard TEST_IPV4_PROGS := $(TEST_BOTH_AF:%=%_ipv4) TEST_IPV6_PROGS := $(TEST_BOTH_AF:%=%_ipv6) diff --git a/tools/testing/selftests/net/tcp_ao/icmps-discard.c b/tools/testing/selftests/net/tcp_ao/icmps-discard.c new file mode 100644 index 000000000000..d77c791754de --- /dev/null +++ b/tools/testing/selftests/net/tcp_ao/icmps-discard.c @@ -0,0 +1,438 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Selftest that verifies that incomping ICMPs are ignored, + * the TCP connection stays alive, no hard or soft errors get reported + * to the usespace and the counter for ignored ICMPs is updated. + * + * RFC5925, 7.8: + * >> A TCP-AO implementation MUST default to ignore incoming ICMPv4 + * messages of Type 3 (destination unreachable), Codes 2-4 (protocol + * unreachable, port unreachable, and fragmentation needed -- ’hard + * errors’), and ICMPv6 Type 1 (destination unreachable), Code 1 + * (administratively prohibited) and Code 4 (port unreachable) intended + * for connections in synchronized states (ESTABLISHED, FIN-WAIT-1, FIN- + * WAIT-2, CLOSE-WAIT, CLOSING, LAST-ACK, TIME-WAIT) that match MKTs. + * + * Author: Dmitry Safonov <dima@...sta.com> + */ +#include <inttypes.h> +#include <linux/icmp.h> +#include <linux/icmpv6.h> +#include <linux/ipv6.h> +#include <netinet/in.h> +#include <netinet/ip.h> +#include <sys/socket.h> +#include "aolib.h" +#include "../../../../include/linux/compiler.h" + +const size_t packets_nr = 20; +const size_t packet_size = 100; +const char *tcpao_icmps = "TCPAODroppedIcmps"; + +#ifdef IPV6_TEST +const char *dst_unreach = "Icmp6InDestUnreachs"; +const int sk_ip_level = SOL_IPV6; +const int sk_recverr = IPV6_RECVERR; +#else +const char *dst_unreach = "InDestUnreachs"; +const int sk_ip_level = SOL_IP; +const int sk_recverr = IP_RECVERR; +#endif + +#define test_icmps_fail test_fail +#define test_icmps_ok test_ok + +static void serve_interfered(int sk) +{ + ssize_t test_quota = packet_size * packets_nr * 10; + uint64_t dest_unreach_a, dest_unreach_b; + uint64_t icmp_ignored_a, icmp_ignored_b; + struct tcp_ao_counters ao_cnt1, ao_cnt2; + bool counter_not_found; + struct netstat *ns_after, *ns_before; + ssize_t bytes; + + ns_before = netstat_read(); + dest_unreach_a = netstat_get(ns_before, dst_unreach, NULL); + icmp_ignored_a = netstat_get(ns_before, tcpao_icmps, NULL); + if (test_get_tcp_ao_counters(sk, &ao_cnt1)) + test_error("test_get_tcp_ao_counters()"); + bytes = test_server_run(sk, test_quota, 0); + ns_after = netstat_read(); + netstat_print_diff(ns_before, ns_after); + dest_unreach_b = netstat_get(ns_after, dst_unreach, NULL); + icmp_ignored_b = netstat_get(ns_after, tcpao_icmps, + &counter_not_found); + if (test_get_tcp_ao_counters(sk, &ao_cnt2)) + test_error("test_get_tcp_ao_counters()"); + + netstat_free(ns_before); + netstat_free(ns_after); + + if (dest_unreach_a >= dest_unreach_b) { + test_fail("%s counter didn't change: %" PRIu64 " >= %" PRIu64, + dst_unreach, dest_unreach_a, dest_unreach_b); + return; + } + test_ok("%s delivered %" PRIu64, + dst_unreach, dest_unreach_b - dest_unreach_a); + if (bytes < 0) + test_icmps_fail("Server failed with %zd: %s", bytes, strerrordesc_np(-bytes)); + else + test_icmps_ok("Server survived %zd bytes of traffic", test_quota); + if (counter_not_found) { + test_fail("Not found %s counter", tcpao_icmps); + return; + } + test_tcp_ao_counters_cmp(NULL, &ao_cnt1, &ao_cnt2, TEST_CNT_GOOD | TEST_CNT_AO_DROPPED_ICMP); + if (icmp_ignored_a >= icmp_ignored_b) { + test_icmps_fail("%s counter didn't change: %" PRIu64 " >= %" PRIu64, + tcpao_icmps, icmp_ignored_a, icmp_ignored_b); + return; + } + test_icmps_ok("ICMPs ignored %" PRIu64, icmp_ignored_b - icmp_ignored_a); +} + +static void *server_fn(void *arg) +{ + int val, err, sk, lsk; + bool accept_icmps = false; + + lsk = test_listen_socket(this_ip_addr, test_server_port, 1); + + if (test_set_ao_flags(lsk, false, accept_icmps)) + test_error("setsockopt(TCP_AO_INFO)"); + + if (test_add_key(lsk, DEFAULT_TEST_PASSWORD, this_ip_dest, -1, 100, 100)) + test_error("setsockopt(TCP_AO_ADD_KEY)"); + synchronize_threads(); + + err = test_wait_fd(lsk, TEST_TIMEOUT_SEC, 0); + if (!err) + test_error("timeouted for accept()"); + else if (err < 0) + test_error("test_wait_fd()"); + + sk = accept(lsk, NULL, NULL); + if (sk < 0) + test_error("accept()"); + + /* Fail on hard ip errors, such as dest unreachable (RFC1122) */ + val = 1; + if (setsockopt(sk, sk_ip_level, sk_recverr, &val, sizeof(val))) + test_error("setsockopt()"); + + synchronize_threads(); + + serve_interfered(sk); + return NULL; +} + +static size_t packets_sent; +static size_t icmps_sent; + +static uint32_t checksum4_nofold(void *data, size_t len, uint32_t sum) +{ + uint16_t *words = data; + size_t i; + + for (i = 0; i < len / sizeof(uint16_t); i++) + sum += words[i]; + if (len & 1) + sum += ((char *)data)[len - 1]; + return sum; +} + +static uint16_t checksum4_fold(void *data, size_t len, uint32_t sum) +{ + sum = checksum4_nofold(data, len, sum); + while (sum > 0xFFFF) + sum = (sum & 0xFFFF) + (sum >> 16); + return ~sum; +} + +static void set_ip4hdr(struct iphdr *iph, size_t packet_len, int proto, + struct sockaddr_in *src, struct sockaddr_in *dst) +{ + iph->version = 4; + iph->ihl = 5; + iph->tos = 0; + iph->tot_len = htons(packet_len); + iph->ttl = 2; + iph->protocol = proto; + iph->saddr = src->sin_addr.s_addr; + iph->daddr = dst->sin_addr.s_addr; + iph->check = checksum4_fold((void *)iph, iph->ihl << 1, 0); +} + +static void icmp_interfere4(uint8_t type, uint8_t code, uint32_t rcv_nxt, + struct sockaddr_in *src, struct sockaddr_in *dst) +{ + int sk = socket(AF_INET, SOCK_RAW, IPPROTO_RAW); + struct { + struct iphdr iph; + struct icmphdr icmph; + struct iphdr iphe; + struct { + uint16_t sport; + uint16_t dport; + uint32_t seq; + } tcph; + } packet = {}; + size_t packet_len; + ssize_t bytes; + + if (sk < 0) + test_error("socket(AF_INET, SOCK_RAW, IPPROTO_RAW)"); + + packet_len = sizeof(packet); + set_ip4hdr(&packet.iph, packet_len, IPPROTO_ICMP, src, dst); + + packet.icmph.type = type; + packet.icmph.code = code; + if (code == ICMP_FRAG_NEEDED) { + randomize_buffer(&packet.icmph.un.frag.mtu, + sizeof(packet.icmph.un.frag.mtu)); + } + + packet_len = sizeof(packet.iphe) + sizeof(packet.tcph); + set_ip4hdr(&packet.iphe, packet_len, IPPROTO_TCP, dst, src); + + packet.tcph.sport = dst->sin_port; + packet.tcph.dport = src->sin_port; + packet.tcph.seq = htonl(rcv_nxt); + + packet_len = sizeof(packet) - sizeof(packet.iph); + packet.icmph.checksum = checksum4_fold((void *)&packet.icmph, + packet_len, 0); + + bytes = sendto(sk, &packet, sizeof(packet), 0, + (struct sockaddr *)dst, sizeof(*dst)); + if (bytes != sizeof(packet)) + test_error("send(): %zd", bytes); + icmps_sent++; + + close(sk); +} + +static void set_ip6hdr(struct ipv6hdr *iph, size_t packet_len, int proto, + struct sockaddr_in6 *src, struct sockaddr_in6 *dst) +{ + iph->version = 6; + iph->payload_len = htons(packet_len); + iph->nexthdr = proto; + iph->hop_limit = 2; + iph->saddr = src->sin6_addr; + iph->daddr = dst->sin6_addr; +} + +static inline uint16_t csum_fold(uint32_t csum) +{ + uint32_t sum = csum; + + sum = (sum & 0xffff) + (sum >> 16); + sum = (sum & 0xffff) + (sum >> 16); + return (uint16_t)~sum; +} + +static inline uint32_t csum_add(uint32_t csum, uint32_t addend) +{ + uint32_t res = csum; + + res += addend; + return res + (res < addend); +} + +noinline uint32_t checksum6_nofold(void *data, size_t len, uint32_t sum) +{ + uint16_t *words = data; + size_t i; + + for (i = 0; i < len / sizeof(uint16_t); i++) + sum = csum_add(sum, words[i]); + if (len & 1) + sum = csum_add(sum, ((char *)data)[len - 1]); + return sum; +} + +noinline uint16_t icmp6_checksum(struct sockaddr_in6 *src, + struct sockaddr_in6 *dst, + void *ptr, size_t len, uint8_t proto) +{ + struct { + struct in6_addr saddr; + struct in6_addr daddr; + uint32_t payload_len; + uint8_t zero[3]; + uint8_t nexthdr; + } pseudo_header = {}; + uint32_t sum; + + pseudo_header.saddr = src->sin6_addr; + pseudo_header.daddr = dst->sin6_addr; + pseudo_header.payload_len = htonl(len); + pseudo_header.nexthdr = proto; + + sum = checksum6_nofold(&pseudo_header, sizeof(pseudo_header), 0); + sum = checksum6_nofold(ptr, len, sum); + + return csum_fold(sum); +} + +static void icmp6_interfere(int type, int code, uint32_t rcv_nxt, + struct sockaddr_in6 *src, struct sockaddr_in6 *dst) +{ + int sk = socket(AF_INET6, SOCK_RAW, IPPROTO_RAW); + struct sockaddr_in6 dst_raw = *dst; + struct { + struct ipv6hdr iph; + struct icmp6hdr icmph; + struct ipv6hdr iphe; + struct { + uint16_t sport; + uint16_t dport; + uint32_t seq; + } tcph; + } packet = {}; + size_t packet_len; + ssize_t bytes; + + + if (sk < 0) + test_error("socket(AF_INET6, SOCK_RAW, IPPROTO_RAW)"); + + packet_len = sizeof(packet) - sizeof(packet.iph); + set_ip6hdr(&packet.iph, packet_len, IPPROTO_ICMPV6, src, dst); + + packet.icmph.icmp6_type = type; + packet.icmph.icmp6_code = code; + + packet_len = sizeof(packet.iphe) + sizeof(packet.tcph); + set_ip6hdr(&packet.iphe, packet_len, IPPROTO_TCP, dst, src); + + packet.tcph.sport = dst->sin6_port; + packet.tcph.dport = src->sin6_port; + packet.tcph.seq = htonl(rcv_nxt); + + packet_len = sizeof(packet) - sizeof(packet.iph); + + packet.icmph.icmp6_cksum = icmp6_checksum(src, dst, + (void *)&packet.icmph, packet_len, IPPROTO_ICMPV6); + + dst_raw.sin6_port = htons(IPPROTO_RAW); + bytes = sendto(sk, &packet, sizeof(packet), 0, + (struct sockaddr *)&dst_raw, sizeof(dst_raw)); + if (bytes != sizeof(packet)) + test_error("send(): %zd", bytes); + icmps_sent++; + + close(sk); +} + +static uint32_t get_rcv_nxt(int sk) +{ + int val = TCP_REPAIR_ON; + uint32_t ret; + socklen_t sz = sizeof(ret); + + if (setsockopt(sk, SOL_TCP, TCP_REPAIR, &val, sizeof(val))) + test_error("setsockopt(TCP_REPAIR)"); + val = TCP_RECV_QUEUE; + if (setsockopt(sk, SOL_TCP, TCP_REPAIR_QUEUE, &val, sizeof(val))) + test_error("setsockopt(TCP_REPAIR_QUEUE)"); + if (getsockopt(sk, SOL_TCP, TCP_QUEUE_SEQ, &ret, &sz)) + test_error("getsockopt(TCP_QUEUE_SEQ)"); + val = TCP_REPAIR_OFF_NO_WP; + if (setsockopt(sk, SOL_TCP, TCP_REPAIR, &val, sizeof(val))) + test_error("setsockopt(TCP_REPAIR)"); + return ret; +} + +static void icmp_interfere(const size_t nr, uint32_t rcv_nxt, void *src, void *dst) +{ + struct sockaddr_in *saddr4 = src; + struct sockaddr_in *daddr4 = dst; + struct sockaddr_in6 *saddr6 = src; + struct sockaddr_in6 *daddr6 = dst; + size_t i; + + if (saddr4->sin_family != daddr4->sin_family) + test_error("Different address families"); + + for (i = 0; i < nr; i++) { + if (saddr4->sin_family == AF_INET) { + icmp_interfere4(ICMP_DEST_UNREACH, ICMP_PROT_UNREACH, + rcv_nxt, saddr4, daddr4); + icmp_interfere4(ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, + rcv_nxt, saddr4, daddr4); + icmp_interfere4(ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, + rcv_nxt, saddr4, daddr4); + icmps_sent += 3; + } else if (saddr4->sin_family == AF_INET6) { + icmp6_interfere(ICMPV6_DEST_UNREACH, + ICMPV6_ADM_PROHIBITED, + rcv_nxt, saddr6, daddr6); + icmp6_interfere(ICMPV6_DEST_UNREACH, + ICMPV6_PORT_UNREACH, + rcv_nxt, saddr6, daddr6); + icmps_sent += 2; + } else { + test_error("Not ip address family"); + } + } +} + +static void send_interfered(int sk) +{ + const unsigned int timeout = TEST_TIMEOUT_SEC; + struct sockaddr_in6 src, dst; + socklen_t addr_sz; + + addr_sz = sizeof(src); + if (getsockname(sk, &src, &addr_sz)) + test_error("getsockname()"); + addr_sz = sizeof(dst); + if (getpeername(sk, &dst, &addr_sz)) + test_error("getpeername()"); + + while (1) { + uint32_t rcv_nxt; + + if (test_client_verify(sk, packet_size, packets_nr, timeout)) { + test_fail("client: connection is broken"); + return; + } + packets_sent += packets_nr; + rcv_nxt = get_rcv_nxt(sk); + icmp_interfere(packets_nr, rcv_nxt, (void *)&src, (void *)&dst); + } +} + +static void *client_fn(void *arg) +{ + int sk = socket(test_family, SOCK_STREAM, IPPROTO_TCP); + + if (sk < 0) + test_error("socket()"); + + if (test_add_key(sk, DEFAULT_TEST_PASSWORD, this_ip_dest, -1, 100, 100)) + test_error("setsockopt(TCP_AO_ADD_KEY)"); + + synchronize_threads(); + if (test_connect_socket(sk, this_ip_dest, test_server_port) <= 0) + test_error("failed to connect()"); + synchronize_threads(); + + send_interfered(sk); + + /* Not expecting client to quit */ + test_fail("client disconnected"); + + return NULL; +} + +int main(int argc, char *argv[]) +{ + test_init(3, server_fn, client_fn); + return 0; +} -- 2.43.0
Powered by blists - more mailing lists