// SPDX-License-Identifier: GPL-2.0
/*
* Check if we can migrate child sockets.
*
* 1. call listen() for 4 server sockets.
* 2. call connect() for 25 client sockets.
* 3. call listen() for 1 server socket. (migration target)
* 4. update a map to migrate all child sockets
* to the last server socket (migrate_map[cookie] = 4)
* 5. call shutdown() for first 4 server sockets
* and migrate the requests in the accept queue
* to the last server socket.
* 6. call listen() for the second server socket.
* 7. call shutdown() for the last server
* and migrate the requests in the accept queue
* to the second server socket.
* 8. call listen() for the last server.
* 9. call shutdown() for the second server
* and migrate the requests in the accept queue
* to the last server socket.
* 10. call accept() for the last server socket.
*
* Author: Kuniyuki Iwashima <[email protected]>
*/
#include <bpf/bpf.h>
#include <bpf/libbpf.h>
#include "test_progs.h"
#include "test_migrate_reuseport.skel.h"
#include "network_helpers.h"
#ifndef TCP_FASTOPEN_CONNECT
#define TCP_FASTOPEN_CONNECT 30
#endif
#define IFINDEX_LO 1
#define NR_SERVERS 5
#define NR_CLIENTS (NR_SERVERS * 5)
#define MIGRATED_TO (NR_SERVERS - 1)
/* fastopenq->max_qlen and sk->sk_max_ack_backlog */
#define QLEN (NR_CLIENTS * 5)
#define MSG "Hello World\0"
#define MSGLEN 12
static struct migrate_reuseport_test_case {
const char *name;
__s64 servers[NR_SERVERS];
__s64 clients[NR_CLIENTS];
struct sockaddr_storage addr;
socklen_t addrlen;
int family;
int state;
bool drop_ack;
bool expire_synack_timer;
bool fastopen;
struct bpf_link *link;
} test_cases[] = {
{
.name = "IPv4 TCP_ESTABLISHED inet_csk_listen_stop",
.family = AF_INET,
.state = BPF_TCP_ESTABLISHED,
.drop_ack = false,
.expire_synack_timer = false,
.fastopen = false,
},
{
.name = "IPv4 TCP_SYN_RECV inet_csk_listen_stop",
.family = AF_INET,
.state = BPF_TCP_SYN_RECV,
.drop_ack = true,
.expire_synack_timer = false,
.fastopen = true,
},
{
.name = "IPv4 TCP_NEW_SYN_RECV reqsk_timer_handler",
.family = AF_INET,
.state = BPF_TCP_NEW_SYN_RECV,
.drop_ack = true,
.expire_synack_timer = true,
.fastopen = false,
},
{
.name = "IPv4 TCP_NEW_SYN_RECV inet_csk_complete_hashdance",
.family = AF_INET,
.state = BPF_TCP_NEW_SYN_RECV,
.drop_ack = true,
.expire_synack_timer = false,
.fastopen = false,
},
{
.name = "IPv6 TCP_ESTABLISHED inet_csk_listen_stop",
.family = AF_INET6,
.state = BPF_TCP_ESTABLISHED,
.drop_ack = false,
.expire_synack_timer = false,
.fastopen = false,
},
{
.name = "IPv6 TCP_SYN_RECV inet_csk_listen_stop",
.family = AF_INET6,
.state = BPF_TCP_SYN_RECV,
.drop_ack = true,
.expire_synack_timer = false,
.fastopen = true,
},
{
.name = "IPv6 TCP_NEW_SYN_RECV reqsk_timer_handler",
.family = AF_INET6,
.state = BPF_TCP_NEW_SYN_RECV,
.drop_ack = true,
.expire_synack_timer = true,
.fastopen = false,
},
{
.name = "IPv6 TCP_NEW_SYN_RECV inet_csk_complete_hashdance",
.family = AF_INET6,
.state = BPF_TCP_NEW_SYN_RECV,
.drop_ack = true,
.expire_synack_timer = false,
.fastopen = false,
}
};
static void init_fds(__s64 fds[], int len)
{
int i;
for (i = 0; i < len; i++)
fds[i] = -1;
}
static void close_fds(__s64 fds[], int len)
{
int i;
for (i = 0; i < len; i++) {
if (fds[i] != -1) {
close(fds[i]);
fds[i] = -1;
}
}
}
static int setup_fastopen(char *buf, int size, int *saved_len, bool restore)
{
int err = 0, fd, len;
fd = open("/proc/sys/net/ipv4/tcp_fastopen", O_RDWR);
if (!ASSERT_NEQ(fd, -1, "open"))
return -1;
if (restore) {
len = write(fd, buf, *saved_len);
if (!ASSERT_EQ(len, *saved_len, "write - restore"))
err = -1;
} else {
*saved_len = read(fd, buf, size);
if (!ASSERT_GE(*saved_len, 1, "read")) {
err = -1;
goto close;
}
err = lseek(fd, 0, SEEK_SET);
if (!ASSERT_OK(err, "lseek"))
goto close;
/* (TFO_CLIENT_ENABLE | TFO_SERVER_ENABLE |
* TFO_CLIENT_NO_COOKIE | TFO_SERVER_COOKIE_NOT_REQD)
*/
len = write(fd, "519", 3);
if (!ASSERT_EQ(len, 3, "write - setup"))
err = -1;
}
close:
close(fd);
return err;
}
static int drop_ack(struct migrate_reuseport_test_case *test_case,
struct test_migrate_reuseport *skel)
{
if (test_case->family == AF_INET)
skel->bss->server_port = ((struct sockaddr_in *)
&test_case->addr)->sin_port;
else
skel->bss->server_port = ((struct sockaddr_in6 *)
&test_case->addr)->sin6_port;
test_case->link = bpf_program__attach_xdp(skel->progs.drop_ack,
IFINDEX_LO);
if (!ASSERT_OK_PTR(test_case->link, "bpf_program__attach_xdp"))
return -1;
return 0;
}
static int pass_ack(struct migrate_reuseport_test_case *test_case)
{
int err;
err = bpf_link__destroy(test_case->link);
if (!ASSERT_OK(err, "bpf_link__destroy"))
return -1;
test_case->link = NULL;
return 0;
}
static int start_servers(struct migrate_reuseport_test_case *test_case,
struct test_migrate_reuseport *skel)
{
int i, err, prog_fd, reuseport = 1, qlen = QLEN;
prog_fd = bpf_program__fd(skel->progs.migrate_reuseport);
make_sockaddr(test_case->family,
test_case->family == AF_INET ? "127.0.0.1" : "::1", 0,
&test_case->addr, &test_case->addrlen);
for (i = 0; i < NR_SERVERS; i++) {
test_case->servers[i] = socket(test_case->family, SOCK_STREAM,
IPPROTO_TCP);
if (!ASSERT_NEQ(test_case->servers[i], -1, "socket"))
return -1;
err = setsockopt(test_case->servers[i], SOL_SOCKET,
SO_REUSEPORT, &reuseport, sizeof(reuseport));
if (!ASSERT_OK(err, "setsockopt - SO_REUSEPORT"))
return -1;
err = bind(test_case->servers[i],
(struct sockaddr *)&test_case->addr,
test_case->addrlen);
if (!ASSERT_OK(err, "bind"))
return -1;
if (i == 0) {
err = setsockopt(test_case->servers[i], SOL_SOCKET,
SO_ATTACH_REUSEPORT_EBPF,
&prog_fd, sizeof(prog_fd));
if (!ASSERT_OK(err,
"setsockopt - SO_ATTACH_REUSEPORT_EBPF"))
return -1;
err = getsockname(test_case->servers[i],
(struct sockaddr *)&test_case->addr,
&test_case->addrlen);
if (!ASSERT_OK(err, "getsockname"))
return -1;
}
if (test_case->fastopen) {
err = setsockopt(test_case->servers[i],
SOL_TCP, TCP_FASTOPEN,
&qlen, sizeof(qlen));
if (!ASSERT_OK(err, "setsockopt - TCP_FASTOPEN"))
return -1;
}
/* All requests will be tied to the first four listeners */
if (i != MIGRATED_TO) {
err = listen(test_case->servers[i], qlen);
if (!ASSERT_OK(err, "listen"))
return -1;
}
}
return 0;
}
static int start_clients(struct migrate_reuseport_test_case *test_case)
{
char buf[MSGLEN] = MSG;
int i, err;
for (i = 0; i < NR_CLIENTS; i++) {
test_case->clients[i] = socket(test_case->family, SOCK_STREAM,
IPPROTO_TCP);
if (!ASSERT_NEQ(test_case->clients[i], -1, "socket"))
return -1;
/* The attached XDP program drops only the final ACK, so
* clients will transition to TCP_ESTABLISHED immediately.
*/
err = settimeo(test_case->clients[i], 100);
if (!ASSERT_OK(err, "settimeo"))
return -1;
if (test_case->fastopen) {
int fastopen = 1;
err = setsockopt(test_case->clients[i], IPPROTO_TCP,
TCP_FASTOPEN_CONNECT, &fastopen,
sizeof(fastopen));
if (!ASSERT_OK(err,
"setsockopt - TCP_FASTOPEN_CONNECT"))
return -1;
}
err = connect(test_case->clients[i],
(struct sockaddr *)&test_case->addr,
test_case->addrlen);
if (!ASSERT_OK(err, "connect"))
return -1;
err = write(test_case->clients[i], buf, MSGLEN);
if (!ASSERT_EQ(err, MSGLEN, "write"))
return -1;
}
return 0;
}
static int update_maps(struct migrate_reuseport_test_case *test_case,
struct test_migrate_reuseport *skel)
{
int i, err, migrated_to = MIGRATED_TO;
int reuseport_map_fd, migrate_map_fd;
__u64 value;
reuseport_map_fd = bpf_map__fd(skel->maps.reuseport_map);
migrate_map_fd = bpf_map__fd(skel->maps.migrate_map);
for (i = 0; i < NR_SERVERS; i++) {
value = (__u64)test_case->servers[i];
err = bpf_map_update_elem(reuseport_map_fd, &i, &value,
BPF_NOEXIST);
if (!ASSERT_OK(err, "bpf_map_update_elem - reuseport_map"))
return -1;
err = bpf_map_lookup_elem(reuseport_map_fd, &i, &value);
if (!ASSERT_OK(err, "bpf_map_lookup_elem - reuseport_map"))
return -1;
err = bpf_map_update_elem(migrate_map_fd, &value, &migrated_to,
BPF_NOEXIST);
if (!ASSERT_OK(err, "bpf_map_update_elem - migrate_map"))
return -1;
}
return 0;
}
static int migrate_dance(struct migrate_reuseport_test_case *test_case)
{
int i, err;
/* Migrate TCP_ESTABLISHED and TCP_SYN_RECV requests
* to the last listener based on eBPF.
*/
for (i = 0; i < MIGRATED_TO; i++) {
err = shutdown(test_case->servers[i], SHUT_RDWR);
if (!ASSERT_OK(err, "shutdown"))
return -1;
}
/* No dance for TCP_NEW_SYN_RECV to migrate based on eBPF */
if (test_case->state == BPF_TCP_NEW_SYN_RECV)
return 0;
/* Note that we use the second listener instead of the
* first one here.
*
* The fist listener is bind()ed with port 0 and,
* SOCK_BINDPORT_LOCK is not set to sk_userlocks, so
* calling listen() again will bind() the first listener
* on a new ephemeral port and detach it from the existing
* reuseport group. (See: __inet_bind(), tcp_set_state())
*
* OTOH, the second one is bind()ed with a specific port,
* and SOCK_BINDPORT_LOCK is set. Thus, re-listen() will
* resurrect the listener on the existing reuseport group.
*/
err = listen(test_case->servers[1], QLEN);
if (!ASSERT_OK(err, "listen"))
return -1;
/* Migrate from the last listener to the second one.
*
* All listeners were detached out of the reuseport_map,
* so migration will be done by kernel random pick from here.
*/
err = shutdown(test_case->servers[MIGRATED_TO], SHUT_RDWR);
if (!ASSERT_OK(err, "shutdown"))
return -1;
/* Back to the existing reuseport group */
err = listen(test_case->servers[MIGRATED_TO], QLEN);
if (!ASSERT_OK(err, "listen"))
return -1;
/* Migrate back to the last one from the second one */
err = shutdown(test_case->servers[1], SHUT_RDWR);
if (!ASSERT_OK(err, "shutdown"))
return -1;
return 0;
}
static void count_requests(struct migrate_reuseport_test_case *test_case,
struct test_migrate_reuseport *skel)
{
struct sockaddr_storage addr;
socklen_t len = sizeof(addr);
int err, cnt = 0, client;
char buf[MSGLEN];
err = settimeo(test_case->servers[MIGRATED_TO], 4000);
if (!ASSERT_OK(err, "settimeo"))
goto out;
for (; cnt < NR_CLIENTS; cnt++) {
client = accept(test_case->servers[MIGRATED_TO],
(struct sockaddr *)&addr, &len);
if (!ASSERT_NEQ(client, -1, "accept"))
goto out;
memset(buf, 0, MSGLEN);
read(client, &buf, MSGLEN);
close(client);
if (!ASSERT_STREQ(buf, MSG, "read"))
goto out;
}
out:
ASSERT_EQ(cnt, NR_CLIENTS, "count in userspace");
switch (test_case->state) {
case BPF_TCP_ESTABLISHED:
cnt = skel->bss->migrated_at_close;
break;
case BPF_TCP_SYN_RECV:
cnt = skel->bss->migrated_at_close_fastopen;
break;
case BPF_TCP_NEW_SYN_RECV:
if (test_case->expire_synack_timer)
cnt = skel->bss->migrated_at_send_synack;
else
cnt = skel->bss->migrated_at_recv_ack;
break;
default:
cnt = 0;
}
ASSERT_EQ(cnt, NR_CLIENTS, "count in BPF prog");
}
static void run_test(struct migrate_reuseport_test_case *test_case,
struct test_migrate_reuseport *skel)
{
int err, saved_len;
char buf[16];
skel->bss->migrated_at_close = 0;
skel->bss->migrated_at_close_fastopen = 0;
skel->bss->migrated_at_send_synack = 0;
skel->bss->migrated_at_recv_ack = 0;
init_fds(test_case->servers, NR_SERVERS);
init_fds(test_case->clients, NR_CLIENTS);
if (test_case->fastopen) {
memset(buf, 0, sizeof(buf));
err = setup_fastopen(buf, sizeof(buf), &saved_len, false);
if (!ASSERT_OK(err, "setup_fastopen - setup"))
return;
}
err = start_servers(test_case, skel);
if (!ASSERT_OK(err, "start_servers"))
goto close_servers;
if (test_case->drop_ack) {
/* Drop the final ACK of the 3-way handshake and stick the
* in-flight requests on TCP_SYN_RECV or TCP_NEW_SYN_RECV.
*/
err = drop_ack(test_case, skel);
if (!ASSERT_OK(err, "drop_ack"))
goto close_servers;
}
/* Tie requests to the first four listeners */
err = start_clients(test_case);
if (!ASSERT_OK(err, "start_clients"))
goto close_clients;
err = listen(test_case->servers[MIGRATED_TO], QLEN);
if (!ASSERT_OK(err, "listen"))
goto close_clients;
err = update_maps(test_case, skel);
if (!ASSERT_OK(err, "fill_maps"))
goto close_clients;
/* Migrate the requests in the accept queue only.
* TCP_NEW_SYN_RECV requests are not migrated at this point.
*/
err = migrate_dance(test_case);
if (!ASSERT_OK(err, "migrate_dance"))
goto close_clients;
if (test_case->expire_synack_timer) {
/* Wait for SYN+ACK timers to expire so that
* reqsk_timer_handler() migrates TCP_NEW_SYN_RECV requests.
*/
sleep(1);
}
if (test_case->link) {
/* Resume 3WHS and migrate TCP_NEW_SYN_RECV requests */
err = pass_ack(test_case);
if (!ASSERT_OK(err, "pass_ack"))
goto close_clients;
}
count_requests(test_case, skel);
close_clients:
close_fds(test_case->clients, NR_CLIENTS);
if (test_case->link) {
err = pass_ack(test_case);
ASSERT_OK(err, "pass_ack - clean up");
}
close_servers:
close_fds(test_case->servers, NR_SERVERS);
if (test_case->fastopen) {
err = setup_fastopen(buf, sizeof(buf), &saved_len, true);
ASSERT_OK(err, "setup_fastopen - restore");
}
}
void serial_test_migrate_reuseport(void)
{
struct test_migrate_reuseport *skel;
int i;
skel = test_migrate_reuseport__open_and_load();
if (!ASSERT_OK_PTR(skel, "open_and_load"))
return;
for (i = 0; i < ARRAY_SIZE(test_cases); i++) {
test__start_subtest(test_cases[i].name);
run_test(&test_cases[i], skel);
}
test_migrate_reuseport__destroy(skel);
}
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