// 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 <[email protected]>
*/
#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
/* Server is expected to fail with hard error if ::accept_icmp is set */
#ifdef TEST_ICMPS_ACCEPT
# define test_icmps_fail test_ok
# define test_icmps_ok test_fail
#else
# define test_icmps_fail test_fail
# define test_icmps_ok test_ok
#endif
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;
}
#ifdef TEST_ICMPS_ACCEPT
test_tcp_ao_counters_cmp(NULL, &ao_cnt1, &ao_cnt2, TEST_CNT_GOOD);
#else
test_tcp_ao_counters_cmp(NULL, &ao_cnt1, &ao_cnt2, TEST_CNT_GOOD | TEST_CNT_AO_DROPPED_ICMP);
#endif
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, sk, lsk;
bool accept_icmps = false;
lsk = test_listen_socket(this_ip_addr, test_server_port, 1);
#ifdef TEST_ICMPS_ACCEPT
accept_icmps = true;
#endif
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();
if (test_wait_fd(lsk, TEST_TIMEOUT_SEC, 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(4, server_fn, client_fn);
return 0;
}
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