// SPDX-License-Identifier: GPL-2.0
/*
* The test checks that both active and passive reset have correct TCP-AO
* signature. An "active" reset (abort) here is procured from closing
* listen() socket with non-accepted connections in the queue:
* inet_csk_listen_stop() => inet_child_forget() =>
* => tcp_disconnect() => tcp_send_active_reset()
*
* The passive reset is quite hard to get on established TCP connections.
* It could be procured from non-established states, but the synchronization
* part from userspace in order to reliably get RST seems uneasy.
* So, instead it's procured by corrupting SEQ number on TIMED-WAIT state.
*
* It's important to test both passive and active RST as they go through
* different code-paths:
* - tcp_send_active_reset() makes no-data skb, sends it with tcp_transmit_skb()
* - tcp_v*_send_reset() create their reply skbs and send them with
* ip_send_unicast_reply()
*
* In both cases TCP-AO signatures have to be correct, which is verified by
* (1) checking that the TCP-AO connection was reset and (2) TCP-AO counters.
*
* Author: Dmitry Safonov <[email protected]>
*/
#include <inttypes.h>
#include "../../../../include/linux/kernel.h"
#include "aolib.h"
const size_t quota = 1000;
const size_t packet_sz = 100;
/*
* Backlog == 0 means 1 connection in queue, see:
* commit 64a146513f8f ("[NET]: Revert incorrect accept queue...")
*/
const unsigned int backlog;
static void netstats_check(struct netstat *before, struct netstat *after,
char *msg)
{
uint64_t before_cnt, after_cnt;
before_cnt = netstat_get(before, "TCPAORequired", NULL);
after_cnt = netstat_get(after, "TCPAORequired", NULL);
if (after_cnt > before_cnt)
test_fail("Segments without AO sign (%s): %" PRIu64 " => %" PRIu64,
msg, before_cnt, after_cnt);
else
test_ok("No segments without AO sign (%s)", msg);
before_cnt = netstat_get(before, "TCPAOGood", NULL);
after_cnt = netstat_get(after, "TCPAOGood", NULL);
if (after_cnt <= before_cnt)
test_fail("Signed AO segments (%s): %" PRIu64 " => %" PRIu64,
msg, before_cnt, after_cnt);
else
test_ok("Signed AO segments (%s): %" PRIu64 " => %" PRIu64,
msg, before_cnt, after_cnt);
before_cnt = netstat_get(before, "TCPAOBad", NULL);
after_cnt = netstat_get(after, "TCPAOBad", NULL);
if (after_cnt > before_cnt)
test_fail("Segments with bad AO sign (%s): %" PRIu64 " => %" PRIu64,
msg, before_cnt, after_cnt);
else
test_ok("No segments with bad AO sign (%s)", msg);
}
/*
* Another way to send RST, but not through tcp_v{4,6}_send_reset()
* is tcp_send_active_reset(), that is not in reply to inbound segment,
* but rather active send. It uses tcp_transmit_skb(), so that should
* work, but as it also sends RST - nice that it can be covered as well.
*/
static void close_forced(int sk)
{
struct linger sl;
sl.l_onoff = 1;
sl.l_linger = 0;
if (setsockopt(sk, SOL_SOCKET, SO_LINGER, &sl, sizeof(sl)))
test_error("setsockopt(SO_LINGER)");
close(sk);
}
static void test_server_active_rst(unsigned int port)
{
struct tcp_ao_counters cnt1, cnt2;
ssize_t bytes;
int sk, lsk;
lsk = test_listen_socket(this_ip_addr, port, backlog);
if (test_add_key(lsk, DEFAULT_TEST_PASSWORD, this_ip_dest, -1, 100, 100))
test_error("setsockopt(TCP_AO_ADD_KEY)");
if (test_get_tcp_ao_counters(lsk, &cnt1))
test_error("test_get_tcp_ao_counters()");
synchronize_threads(); /* 1: MKT added */
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()");
synchronize_threads(); /* 2: connection accept()ed, another queued */
if (test_get_tcp_ao_counters(lsk, &cnt2))
test_error("test_get_tcp_ao_counters()");
synchronize_threads(); /* 3: close listen socket */
close(lsk);
bytes = test_server_run(sk, quota, 0);
if (bytes != quota)
test_error("servered only %zd bytes", bytes);
else
test_ok("servered %zd bytes", bytes);
synchronize_threads(); /* 4: finishing up */
close_forced(sk);
synchronize_threads(); /* 5: closed active sk */
synchronize_threads(); /* 6: counters checks */
if (test_tcp_ao_counters_cmp("active RST server", &cnt1, &cnt2, TEST_CNT_GOOD))
test_fail("MKT counters (server) have not only good packets");
else
test_ok("MKT counters are good on server");
}
static void test_server_passive_rst(unsigned int port)
{
struct tcp_ao_counters ao1, ao2;
int sk, lsk;
ssize_t bytes;
lsk = test_listen_socket(this_ip_addr, port, 1);
if (test_add_key(lsk, DEFAULT_TEST_PASSWORD, this_ip_dest, -1, 100, 100))
test_error("setsockopt(TCP_AO_ADD_KEY)");
synchronize_threads(); /* 1: MKT added => connect() */
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()");
synchronize_threads(); /* 2: accepted => send data */
close(lsk);
if (test_get_tcp_ao_counters(sk, &ao1))
test_error("test_get_tcp_ao_counters()");
bytes = test_server_run(sk, quota, TEST_TIMEOUT_SEC);
if (bytes != quota) {
if (bytes > 0)
test_fail("server served: %zd", bytes);
else
test_fail("server returned %zd", bytes);
}
synchronize_threads(); /* 3: checkpoint the client */
synchronize_threads(); /* 4: close the server, creating twsk */
if (test_get_tcp_ao_counters(sk, &ao2))
test_error("test_get_tcp_ao_counters()");
close(sk);
synchronize_threads(); /* 5: restore the socket, send more data */
test_tcp_ao_counters_cmp("passive RST server", &ao1, &ao2, TEST_CNT_GOOD);
synchronize_threads(); /* 6: server exits */
}
static void *server_fn(void *arg)
{
struct netstat *ns_before, *ns_after;
unsigned int port = test_server_port;
ns_before = netstat_read();
test_server_active_rst(port++);
test_server_passive_rst(port++);
ns_after = netstat_read();
netstats_check(ns_before, ns_after, "server");
netstat_free(ns_after);
netstat_free(ns_before);
synchronize_threads(); /* exit */
synchronize_threads(); /* don't race to exit() - client exits */
return NULL;
}
static int test_wait_fds(int sk[], size_t nr, bool is_writable[],
ssize_t wait_for, time_t sec)
{
struct timeval tv = { .tv_sec = sec };
struct timeval *ptv = NULL;
fd_set left;
size_t i;
int ret;
FD_ZERO(&left);
for (i = 0; i < nr; i++) {
FD_SET(sk[i], &left);
if (is_writable)
is_writable[i] = false;
}
if (sec)
ptv = &tv;
do {
bool is_empty = true;
fd_set fds, efds;
int nfd = 0;
FD_ZERO(&fds);
FD_ZERO(&efds);
for (i = 0; i < nr; i++) {
if (!FD_ISSET(sk[i], &left))
continue;
if (sk[i] > nfd)
nfd = sk[i];
FD_SET(sk[i], &fds);
FD_SET(sk[i], &efds);
is_empty = false;
}
if (is_empty)
return -ENOENT;
errno = 0;
ret = select(nfd + 1, NULL, &fds, &efds, ptv);
if (ret < 0)
return -errno;
if (!ret)
return -ETIMEDOUT;
for (i = 0; i < nr; i++) {
if (FD_ISSET(sk[i], &fds)) {
if (is_writable)
is_writable[i] = true;
FD_CLR(sk[i], &left);
wait_for--;
continue;
}
if (FD_ISSET(sk[i], &efds)) {
FD_CLR(sk[i], &left);
wait_for--;
}
}
} while (wait_for > 0);
return 0;
}
static void test_client_active_rst(unsigned int port)
{
int i, sk[3], err;
bool is_writable[ARRAY_SIZE(sk)] = {false};
unsigned int last = ARRAY_SIZE(sk) - 1;
for (i = 0; i < ARRAY_SIZE(sk); i++) {
sk[i] = socket(test_family, SOCK_STREAM, IPPROTO_TCP);
if (sk[i] < 0)
test_error("socket()");
if (test_add_key(sk[i], DEFAULT_TEST_PASSWORD,
this_ip_dest, -1, 100, 100))
test_error("setsockopt(TCP_AO_ADD_KEY)");
}
synchronize_threads(); /* 1: MKT added */
for (i = 0; i < last; i++) {
err = _test_connect_socket(sk[i], this_ip_dest, port,
(i == 0) ? TEST_TIMEOUT_SEC : -1);
if (err < 0)
test_error("failed to connect()");
}
synchronize_threads(); /* 2: two connections: one accept()ed, another queued */
err = test_wait_fds(sk, last, is_writable, last, TEST_TIMEOUT_SEC);
if (err < 0)
test_error("test_wait_fds(): %d", err);
/* async connect() with third sk to get into request_sock_queue */
err = _test_connect_socket(sk[last], this_ip_dest, port, -1);
if (err < 0)
test_error("failed to connect()");
synchronize_threads(); /* 3: close listen socket */
if (test_client_verify(sk[0], packet_sz, quota / packet_sz, TEST_TIMEOUT_SEC))
test_fail("Failed to send data on connected socket");
else
test_ok("Verified established tcp connection");
synchronize_threads(); /* 4: finishing up */
synchronize_threads(); /* 5: closed active sk */
/*
* Wait for 2 connections: one accepted, another in the accept queue,
* the one in request_sock_queue won't get fully established, so
* doesn't receive an active RST, see inet_csk_listen_stop().
*/
err = test_wait_fds(sk, last, NULL, last, TEST_TIMEOUT_SEC);
if (err < 0)
test_error("select(): %d", err);
for (i = 0; i < ARRAY_SIZE(sk); i++) {
socklen_t slen = sizeof(err);
if (getsockopt(sk[i], SOL_SOCKET, SO_ERROR, &err, &slen))
test_error("getsockopt()");
if (is_writable[i] && err != ECONNRESET) {
test_fail("sk[%d] = %d, err = %d, connection wasn't reset",
i, sk[i], err);
} else {
test_ok("sk[%d] = %d%s", i, sk[i],
is_writable[i] ? ", connection was reset" : "");
}
}
synchronize_threads(); /* 6: counters checks */
}
static void test_client_passive_rst(unsigned int port)
{
struct tcp_ao_counters ao1, ao2;
struct tcp_ao_repair ao_img;
struct tcp_sock_state img;
sockaddr_af saddr;
int sk, err;
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(); /* 1: MKT added => connect() */
if (test_connect_socket(sk, this_ip_dest, port) <= 0)
test_error("failed to connect()");
synchronize_threads(); /* 2: accepted => send data */
if (test_client_verify(sk, packet_sz, quota / packet_sz, TEST_TIMEOUT_SEC))
test_fail("Failed to send data on connected socket");
else
test_ok("Verified established tcp connection");
synchronize_threads(); /* 3: checkpoint the client */
test_enable_repair(sk);
test_sock_checkpoint(sk, &img, &saddr);
test_ao_checkpoint(sk, &ao_img);
test_disable_repair(sk);
synchronize_threads(); /* 4: close the server, creating twsk */
/*
* The "corruption" in SEQ has to be small enough to fit into TCP
* window, see tcp_timewait_state_process() for out-of-window
* segments.
*/
img.out.seq += 5; /* 5 is more noticeable in tcpdump than 1 */
/*
* FIXME: This is kind-of ugly and dirty, but it works.
*
* At this moment, the server has close'ed(sk).
* The passive RST that is being targeted here is new data after
* half-duplex close, see tcp_timewait_state_process() => TCP_TW_RST
*
* What is needed here is:
* (1) wait for FIN from the server
* (2) make sure that the ACK from the client went out
* (3) make sure that the ACK was received and processed by the server
*
* Otherwise, the data that will be sent from "repaired" socket
* post SEQ corruption may get to the server before it's in
* TCP_FIN_WAIT2.
*
* (1) is easy with select()/poll()
* (2) is possible by polling tcpi_state from TCP_INFO
* (3) is quite complex: as server's socket was already closed,
* probably the way to do it would be tcp-diag.
*/
sleep(TEST_RETRANSMIT_SEC);
synchronize_threads(); /* 5: restore the socket, send more data */
test_kill_sk(sk);
sk = socket(test_family, SOCK_STREAM, IPPROTO_TCP);
if (sk < 0)
test_error("socket()");
test_enable_repair(sk);
test_sock_restore(sk, &img, &saddr, this_ip_dest, port);
if (test_add_repaired_key(sk, DEFAULT_TEST_PASSWORD, 0, this_ip_dest, -1, 100, 100))
test_error("setsockopt(TCP_AO_ADD_KEY)");
test_ao_restore(sk, &ao_img);
if (test_get_tcp_ao_counters(sk, &ao1))
test_error("test_get_tcp_ao_counters()");
test_disable_repair(sk);
test_sock_state_free(&img);
/*
* This is how "passive reset" is acquired in this test from TCP_TW_RST:
*
* IP 10.0.254.1.7011 > 10.0.1.1.59772: Flags [P.], seq 901:1001, ack 1001, win 249,
* options [tcp-ao keyid 100 rnextkeyid 100 mac 0x10217d6c36a22379086ef3b1], length 100
* IP 10.0.254.1.7011 > 10.0.1.1.59772: Flags [F.], seq 1001, ack 1001, win 249,
* options [tcp-ao keyid 100 rnextkeyid 100 mac 0x104ffc99b98c10a5298cc268], length 0
* IP 10.0.1.1.59772 > 10.0.254.1.7011: Flags [.], ack 1002, win 251,
* options [tcp-ao keyid 100 rnextkeyid 100 mac 0xe496dd4f7f5a8a66873c6f93,nop,nop,sack 1 {1001:1002}], length 0
* IP 10.0.1.1.59772 > 10.0.254.1.7011: Flags [P.], seq 1006:1106, ack 1001, win 251,
* options [tcp-ao keyid 100 rnextkeyid 100 mac 0x1b5f3330fb23fbcd0c77d0ca], length 100
* IP 10.0.254.1.7011 > 10.0.1.1.59772: Flags [R], seq 3215596252, win 0,
* options [tcp-ao keyid 100 rnextkeyid 100 mac 0x0bcfbbf497bce844312304b2], length 0
*/
err = test_client_verify(sk, packet_sz, quota / packet_sz, 2 * TEST_TIMEOUT_SEC);
/* Make sure that the connection was reset, not timeouted */
if (err && err == -ECONNRESET)
test_ok("client sock was passively reset post-seq-adjust");
else if (err)
test_fail("client sock was not reset post-seq-adjust: %d", err);
else
test_fail("client sock is yet connected post-seq-adjust");
if (test_get_tcp_ao_counters(sk, &ao2))
test_error("test_get_tcp_ao_counters()");
synchronize_threads(); /* 6: server exits */
close(sk);
test_tcp_ao_counters_cmp("client passive RST", &ao1, &ao2, TEST_CNT_GOOD);
}
static void *client_fn(void *arg)
{
struct netstat *ns_before, *ns_after;
unsigned int port = test_server_port;
ns_before = netstat_read();
test_client_active_rst(port++);
test_client_passive_rst(port++);
ns_after = netstat_read();
netstats_check(ns_before, ns_after, "client");
netstat_free(ns_after);
netstat_free(ns_before);
synchronize_threads(); /* exit */
return NULL;
}
int main(int argc, char *argv[])
{
test_init(15, server_fn, client_fn);
return 0;
}
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