// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
// Copyright (c) 2020 Cloudflare
/*
* Test BPF attach point for INET socket lookup (BPF_SK_LOOKUP).
*
* Tests exercise:
* - attaching/detaching/querying programs to BPF_SK_LOOKUP hook,
* - redirecting socket lookup to a socket selected by BPF program,
* - failing a socket lookup on BPF program's request,
* - error scenarios for selecting a socket from BPF program,
* - accessing BPF program context,
* - attaching and running multiple BPF programs.
*
* Tests run in a dedicated network namespace.
*/
#define _GNU_SOURCE
#include <arpa/inet.h>
#include <assert.h>
#include <errno.h>
#include <error.h>
#include <fcntl.h>
#include <sched.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <bpf/libbpf.h>
#include <bpf/bpf.h>
#include "test_progs.h"
#include "bpf_util.h"
#include "cgroup_helpers.h"
#include "network_helpers.h"
#include "testing_helpers.h"
#include "test_sk_lookup.skel.h"
/* External (address, port) pairs the client sends packets to. */
#define EXT_IP4 "127.0.0.1"
#define EXT_IP6 "fd00::1"
#define EXT_PORT 7007
/* Internal (address, port) pairs the server listens/receives at. */
#define INT_IP4 "127.0.0.2"
#define INT_IP4_V6 "::ffff:127.0.0.2"
#define INT_IP6 "fd00::2"
#define INT_PORT 8008
#define IO_TIMEOUT_SEC 3
enum server {
SERVER_A = 0,
SERVER_B = 1,
MAX_SERVERS,
};
enum {
PROG1 = 0,
PROG2,
};
struct inet_addr {
const char *ip;
unsigned short port;
};
struct test {
const char *desc;
struct bpf_program *lookup_prog;
struct bpf_program *reuseport_prog;
struct bpf_map *sock_map;
int sotype;
struct inet_addr connect_to;
struct inet_addr listen_at;
enum server accept_on;
bool reuseport_has_conns; /* Add a connected socket to reuseport group */
};
struct cb_opts {
int family;
int sotype;
bool reuseport;
};
static __u32 duration; /* for CHECK macro */
static bool is_ipv6(const char *ip)
{
return !!strchr(ip, ':');
}
static int attach_reuseport(int sock_fd, struct bpf_program *reuseport_prog)
{
int err, prog_fd;
prog_fd = bpf_program__fd(reuseport_prog);
if (prog_fd < 0) {
errno = -prog_fd;
return -1;
}
err = setsockopt(sock_fd, SOL_SOCKET, SO_ATTACH_REUSEPORT_EBPF,
&prog_fd, sizeof(prog_fd));
if (err)
return -1;
return 0;
}
static socklen_t inetaddr_len(const struct sockaddr_storage *addr)
{
return (addr->ss_family == AF_INET ? sizeof(struct sockaddr_in) :
addr->ss_family == AF_INET6 ? sizeof(struct sockaddr_in6) : 0);
}
static int make_socket(int sotype, const char *ip, int port,
struct sockaddr_storage *addr)
{
struct timeval timeo = { .tv_sec = IO_TIMEOUT_SEC };
int err, family, fd;
family = is_ipv6(ip) ? AF_INET6 : AF_INET;
err = make_sockaddr(family, ip, port, addr, NULL);
if (CHECK(err, "make_address", "failed\n"))
return -1;
fd = socket(addr->ss_family, sotype, 0);
if (CHECK(fd < 0, "socket", "failed\n")) {
log_err("failed to make socket");
return -1;
}
err = setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &timeo, sizeof(timeo));
if (CHECK(err, "setsockopt(SO_SNDTIMEO)", "failed\n")) {
log_err("failed to set SNDTIMEO");
close(fd);
return -1;
}
err = setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &timeo, sizeof(timeo));
if (CHECK(err, "setsockopt(SO_RCVTIMEO)", "failed\n")) {
log_err("failed to set RCVTIMEO");
close(fd);
return -1;
}
return fd;
}
static int setsockopts(int fd, void *opts)
{
struct cb_opts *co = (struct cb_opts *)opts;
const int one = 1;
int err = 0;
/* Enabled for UDPv6 sockets for IPv4-mapped IPv6 to work. */
if (co->sotype == SOCK_DGRAM) {
err = setsockopt(fd, SOL_IP, IP_RECVORIGDSTADDR, &one,
sizeof(one));
if (CHECK(err, "setsockopt(IP_RECVORIGDSTADDR)", "failed\n")) {
log_err("failed to enable IP_RECVORIGDSTADDR");
goto fail;
}
}
if (co->sotype == SOCK_DGRAM && co->family == AF_INET6) {
err = setsockopt(fd, SOL_IPV6, IPV6_RECVORIGDSTADDR, &one,
sizeof(one));
if (CHECK(err, "setsockopt(IPV6_RECVORIGDSTADDR)", "failed\n")) {
log_err("failed to enable IPV6_RECVORIGDSTADDR");
goto fail;
}
}
if (co->sotype == SOCK_STREAM) {
err = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one,
sizeof(one));
if (CHECK(err, "setsockopt(SO_REUSEADDR)", "failed\n")) {
log_err("failed to enable SO_REUSEADDR");
goto fail;
}
}
if (co->reuseport) {
err = setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &one,
sizeof(one));
if (CHECK(err, "setsockopt(SO_REUSEPORT)", "failed\n")) {
log_err("failed to enable SO_REUSEPORT");
goto fail;
}
}
fail:
return err;
}
static int make_server(int sotype, const char *ip, int port,
struct bpf_program *reuseport_prog)
{
struct cb_opts cb_opts = {
.family = is_ipv6(ip) ? AF_INET6 : AF_INET,
.sotype = sotype,
.reuseport = reuseport_prog,
};
struct network_helper_opts opts = {
.backlog = SOMAXCONN,
.post_socket_cb = setsockopts,
.cb_opts = &cb_opts,
};
int err, fd;
fd = start_server_str(cb_opts.family, sotype, ip, port, &opts);
if (!ASSERT_OK_FD(fd, "start_server_str"))
return -1;
/* Late attach reuseport prog so we can have one init path */
if (reuseport_prog) {
err = attach_reuseport(fd, reuseport_prog);
if (CHECK(err, "attach_reuseport", "failed\n")) {
log_err("failed to attach reuseport prog");
goto fail;
}
}
return fd;
fail:
close(fd);
return -1;
}
static int make_client(int sotype, const char *ip, int port)
{
struct sockaddr_storage addr = {0};
int err, fd;
fd = make_socket(sotype, ip, port, &addr);
if (fd < 0)
return -1;
err = connect(fd, (void *)&addr, inetaddr_len(&addr));
if (CHECK(err, "make_client", "connect")) {
log_err("failed to connect client socket");
goto fail;
}
return fd;
fail:
close(fd);
return -1;
}
static __u64 socket_cookie(int fd)
{
__u64 cookie;
socklen_t cookie_len = sizeof(cookie);
if (CHECK(getsockopt(fd, SOL_SOCKET, SO_COOKIE, &cookie, &cookie_len) < 0,
"getsockopt(SO_COOKIE)", "%s\n", strerror(errno)))
return 0;
return cookie;
}
static int fill_sk_lookup_ctx(struct bpf_sk_lookup *ctx, const char *local_ip, __u16 local_port,
const char *remote_ip, __u16 remote_port)
{
void *local, *remote;
int err;
memset(ctx, 0, sizeof(*ctx));
ctx->local_port = local_port;
ctx->remote_port = htons(remote_port);
if (is_ipv6(local_ip)) {
ctx->family = AF_INET6;
local = &ctx->local_ip6[0];
remote = &ctx->remote_ip6[0];
} else {
ctx->family = AF_INET;
local = &ctx->local_ip4;
remote = &ctx->remote_ip4;
}
err = inet_pton(ctx->family, local_ip, local);
if (CHECK(err != 1, "inet_pton", "local_ip failed\n"))
return 1;
err = inet_pton(ctx->family, remote_ip, remote);
if (CHECK(err != 1, "inet_pton", "remote_ip failed\n"))
return 1;
return 0;
}
static int send_byte(int fd)
{
ssize_t n;
errno = 0;
n = send(fd, "a", 1, 0);
if (CHECK(n <= 0, "send_byte", "send")) {
log_err("failed/partial send");
return -1;
}
return 0;
}
static int recv_byte(int fd)
{
char buf[1];
ssize_t n;
n = recv(fd, buf, sizeof(buf), 0);
if (CHECK(n <= 0, "recv_byte", "recv")) {
log_err("failed/partial recv");
return -1;
}
return 0;
}
static int tcp_recv_send(int server_fd)
{
char buf[1];
int ret, fd;
ssize_t n;
fd = accept(server_fd, NULL, NULL);
if (CHECK(fd < 0, "accept", "failed\n")) {
log_err("failed to accept");
return -1;
}
n = recv(fd, buf, sizeof(buf), 0);
if (CHECK(n <= 0, "recv", "failed\n")) {
log_err("failed/partial recv");
ret = -1;
goto close;
}
n = send(fd, buf, n, 0);
if (CHECK(n <= 0, "send", "failed\n")) {
log_err("failed/partial send");
ret = -1;
goto close;
}
ret = 0;
close:
close(fd);
return ret;
}
static void v4_to_v6(struct sockaddr_storage *ss)
{
struct sockaddr_in6 *v6 = (struct sockaddr_in6 *)ss;
struct sockaddr_in v4 = *(struct sockaddr_in *)ss;
v6->sin6_family = AF_INET6;
v6->sin6_port = v4.sin_port;
v6->sin6_addr.s6_addr[10] = 0xff;
v6->sin6_addr.s6_addr[11] = 0xff;
memcpy(&v6->sin6_addr.s6_addr[12], &v4.sin_addr.s_addr, 4);
memset(&v6->sin6_addr.s6_addr[0], 0, 10);
}
static int udp_recv_send(int server_fd)
{
char cmsg_buf[CMSG_SPACE(sizeof(struct sockaddr_storage))];
struct sockaddr_storage _src_addr = { 0 };
struct sockaddr_storage *src_addr = &_src_addr;
struct sockaddr_storage *dst_addr = NULL;
struct msghdr msg = { 0 };
struct iovec iov = { 0 };
struct cmsghdr *cm;
char buf[1];
int ret, fd;
ssize_t n;
iov.iov_base = buf;
iov.iov_len = sizeof(buf);
msg.msg_name = src_addr;
msg.msg_namelen = sizeof(*src_addr);
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_control = cmsg_buf;
msg.msg_controllen = sizeof(cmsg_buf);
errno = 0;
n = recvmsg(server_fd, &msg, 0);
if (CHECK(n <= 0, "recvmsg", "failed\n")) {
log_err("failed to receive");
return -1;
}
if (CHECK(msg.msg_flags & MSG_CTRUNC, "recvmsg", "truncated cmsg\n"))
return -1;
for (cm = CMSG_FIRSTHDR(&msg); cm; cm = CMSG_NXTHDR(&msg, cm)) {
if ((cm->cmsg_level == SOL_IP &&
cm->cmsg_type == IP_ORIGDSTADDR) ||
(cm->cmsg_level == SOL_IPV6 &&
cm->cmsg_type == IPV6_ORIGDSTADDR)) {
dst_addr = (struct sockaddr_storage *)CMSG_DATA(cm);
break;
}
log_err("warning: ignored cmsg at level %d type %d",
cm->cmsg_level, cm->cmsg_type);
}
if (CHECK(!dst_addr, "recvmsg", "missing ORIGDSTADDR\n"))
return -1;
/* Server socket bound to IPv4-mapped IPv6 address */
if (src_addr->ss_family == AF_INET6 &&
dst_addr->ss_family == AF_INET) {
v4_to_v6(dst_addr);
}
/* Reply from original destination address. */
fd = start_server_addr(SOCK_DGRAM, dst_addr, sizeof(*dst_addr), NULL);
if (!ASSERT_OK_FD(fd, "start_server_addr")) {
log_err("failed to create tx socket");
return -1;
}
msg.msg_control = NULL;
msg.msg_controllen = 0;
n = sendmsg(fd, &msg, 0);
if (CHECK(n <= 0, "sendmsg", "failed\n")) {
log_err("failed to send echo reply");
ret = -1;
goto out;
}
ret = 0;
out:
close(fd);
return ret;
}
static int tcp_echo_test(int client_fd, int server_fd)
{
int err;
err = send_byte(client_fd);
if (err)
return -1;
err = tcp_recv_send(server_fd);
if (err)
return -1;
err = recv_byte(client_fd);
if (err)
return -1;
return 0;
}
static int udp_echo_test(int client_fd, int server_fd)
{
int err;
err = send_byte(client_fd);
if (err)
return -1;
err = udp_recv_send(server_fd);
if (err)
return -1;
err = recv_byte(client_fd);
if (err)
return -1;
return 0;
}
static struct bpf_link *attach_lookup_prog(struct bpf_program *prog)
{
struct bpf_link *link;
int net_fd;
net_fd = open("/proc/self/ns/net", O_RDONLY);
if (CHECK(net_fd < 0, "open", "failed\n")) {
log_err("failed to open /proc/self/ns/net");
return NULL;
}
link = bpf_program__attach_netns(prog, net_fd);
if (!ASSERT_OK_PTR(link, "bpf_program__attach_netns")) {
errno = -PTR_ERR(link);
log_err("failed to attach program '%s' to netns",
bpf_program__name(prog));
link = NULL;
}
close(net_fd);
return link;
}
static int update_lookup_map(struct bpf_map *map, int index, int sock_fd)
{
int err, map_fd;
uint64_t value;
map_fd = bpf_map__fd(map);
if (CHECK(map_fd < 0, "bpf_map__fd", "failed\n")) {
errno = -map_fd;
log_err("failed to get map FD");
return -1;
}
value = (uint64_t)sock_fd;
err = bpf_map_update_elem(map_fd, &index, &value, BPF_NOEXIST);
if (CHECK(err, "bpf_map_update_elem", "failed\n")) {
log_err("failed to update redir_map @ %d", index);
return -1;
}
return 0;
}
static void query_lookup_prog(struct test_sk_lookup *skel)
{
struct bpf_link *link[3] = {};
struct bpf_link_info info;
__u32 attach_flags = 0;
__u32 prog_ids[3] = {};
__u32 prog_cnt = 3;
__u32 prog_id;
int net_fd;
int err;
net_fd = open("/proc/self/ns/net", O_RDONLY);
if (CHECK(net_fd < 0, "open", "failed\n")) {
log_err("failed to open /proc/self/ns/net");
return;
}
link[0] = attach_lookup_prog(skel->progs.lookup_pass);
if (!link[0])
goto close;
link[1] = attach_lookup_prog(skel->progs.lookup_pass);
if (!link[1])
goto detach;
link[2] = attach_lookup_prog(skel->progs.lookup_drop);
if (!link[2])
goto detach;
err = bpf_prog_query(net_fd, BPF_SK_LOOKUP, 0 /* query flags */,
&attach_flags, prog_ids, &prog_cnt);
if (CHECK(err, "bpf_prog_query", "failed\n")) {
log_err("failed to query lookup prog");
goto detach;
}
errno = 0;
if (CHECK(attach_flags != 0, "bpf_prog_query",
"wrong attach_flags on query: %u", attach_flags))
goto detach;
if (CHECK(prog_cnt != 3, "bpf_prog_query",
"wrong program count on query: %u", prog_cnt))
goto detach;
prog_id = link_info_prog_id(link[0], &info);
CHECK(prog_ids[0] != prog_id, "bpf_prog_query",
"invalid program #0 id on query: %u != %u\n",
prog_ids[0], prog_id);
CHECK(info.netns.netns_ino == 0, "netns_ino",
"unexpected netns_ino: %u\n", info.netns.netns_ino);
prog_id = link_info_prog_id(link[1], &info);
CHECK(prog_ids[1] != prog_id, "bpf_prog_query",
"invalid program #1 id on query: %u != %u\n",
prog_ids[1], prog_id);
CHECK(info.netns.netns_ino == 0, "netns_ino",
"unexpected netns_ino: %u\n", info.netns.netns_ino);
prog_id = link_info_prog_id(link[2], &info);
CHECK(prog_ids[2] != prog_id, "bpf_prog_query",
"invalid program #2 id on query: %u != %u\n",
prog_ids[2], prog_id);
CHECK(info.netns.netns_ino == 0, "netns_ino",
"unexpected netns_ino: %u\n", info.netns.netns_ino);
err = bpf_link__detach(link[0]);
if (CHECK(err, "link_detach", "failed %d\n", err))
goto detach;
/* prog id is still there, but netns_ino is zeroed out */
prog_id = link_info_prog_id(link[0], &info);
CHECK(prog_ids[0] != prog_id, "bpf_prog_query",
"invalid program #0 id on query: %u != %u\n",
prog_ids[0], prog_id);
CHECK(info.netns.netns_ino != 0, "netns_ino",
"unexpected netns_ino: %u\n", info.netns.netns_ino);
detach:
if (link[2])
bpf_link__destroy(link[2]);
if (link[1])
bpf_link__destroy(link[1]);
if (link[0])
bpf_link__destroy(link[0]);
close:
close(net_fd);
}
static void run_lookup_prog(const struct test *t)
{
int server_fds[] = { [0 ... MAX_SERVERS - 1] = -1 };
int client_fd, reuse_conn_fd = -1;
struct bpf_link *lookup_link;
int i, err;
lookup_link = attach_lookup_prog(t->lookup_prog);
if (!lookup_link)
return;
for (i = 0; i < ARRAY_SIZE(server_fds); i++) {
server_fds[i] = make_server(t->sotype, t->listen_at.ip,
t->listen_at.port,
t->reuseport_prog);
if (server_fds[i] < 0)
goto close;
err = update_lookup_map(t->sock_map, i, server_fds[i]);
if (err)
goto close;
/* want just one server for non-reuseport test */
if (!t->reuseport_prog)
break;
}
/* Regular UDP socket lookup with reuseport behaves
* differently when reuseport group contains connected
* sockets. Check that adding a connected UDP socket to the
* reuseport group does not affect how reuseport works with
* BPF socket lookup.
*/
if (t->reuseport_has_conns) {
/* Add an extra socket to reuseport group */
reuse_conn_fd = make_server(t->sotype, t->listen_at.ip,
t->listen_at.port,
t->reuseport_prog);
if (reuse_conn_fd < 0)
goto close;
/* Connect the extra socket to itself */
err = connect_fd_to_fd(reuse_conn_fd, reuse_conn_fd, 0);
if (!ASSERT_OK(err, "connect_fd_to_fd"))
goto close;
}
client_fd = make_client(t->sotype, t->connect_to.ip, t->connect_to.port);
if (client_fd < 0)
goto close;
if (t->sotype == SOCK_STREAM)
tcp_echo_test(client_fd, server_fds[t->accept_on]);
else
udp_echo_test(client_fd, server_fds[t->accept_on]);
close(client_fd);
close:
if (reuse_conn_fd != -1)
close(reuse_conn_fd);
for (i = 0; i < ARRAY_SIZE(server_fds); i++) {
if (server_fds[i] != -1)
close(server_fds[i]);
}
bpf_link__destroy(lookup_link);
}
static void test_redirect_lookup(struct test_sk_lookup *skel)
{
const struct test tests[] = {
{
.desc = "TCP IPv4 redir port",
.lookup_prog = skel->progs.redir_port,
.sock_map = skel->maps.redir_map,
.sotype = SOCK_STREAM,
.connect_to = { EXT_IP4, EXT_PORT },
.listen_at = { EXT_IP4, INT_PORT },
},
{
.desc = "TCP IPv4 redir addr",
.lookup_prog = skel->progs.redir_ip4,
.sock_map = skel->maps.redir_map,
.sotype = SOCK_STREAM,
.connect_to = { EXT_IP4, EXT_PORT },
.listen_at = { INT_IP4, EXT_PORT },
},
{
.desc = "TCP IPv4 redir with reuseport",
.lookup_prog = skel->progs.select_sock_a,
.reuseport_prog = skel->progs.select_sock_b,
.sock_map = skel->maps.redir_map,
.sotype = SOCK_STREAM,
.connect_to = { EXT_IP4, EXT_PORT },
.listen_at = { INT_IP4, INT_PORT },
.accept_on = SERVER_B,
},
{
.desc = "TCP IPv4 redir skip reuseport",
.lookup_prog = skel->progs.select_sock_a_no_reuseport,
.reuseport_prog = skel->progs.select_sock_b,
.sock_map = skel->maps.redir_map,
.sotype = SOCK_STREAM,
.connect_to = { EXT_IP4, EXT_PORT },
.listen_at = { INT_IP4, INT_PORT },
.accept_on = SERVER_A,
},
{
.desc = "TCP IPv6 redir port",
.lookup_prog = skel->progs.redir_port,
.sock_map = skel->maps.redir_map,
.sotype = SOCK_STREAM,
.connect_to = { EXT_IP6, EXT_PORT },
.listen_at = { EXT_IP6, INT_PORT },
},
{
.desc = "TCP IPv6 redir addr",
.lookup_prog = skel->progs.redir_ip6,
.sock_map = skel->maps.redir_map,
.sotype = SOCK_STREAM,
.connect_to = { EXT_IP6, EXT_PORT },
.listen_at = { INT_IP6, EXT_PORT },
},
{
.desc = "TCP IPv4->IPv6 redir port",
.lookup_prog = skel->progs.redir_port,
.sock_map = skel->maps.redir_map,
.sotype = SOCK_STREAM,
.connect_to = { EXT_IP4, EXT_PORT },
.listen_at = { INT_IP4_V6, INT_PORT },
},
{
.desc = "TCP IPv6 redir with reuseport",
.lookup_prog = skel->progs.select_sock_a,
.reuseport_prog = skel->progs.select_sock_b,
.sock_map = skel->maps.redir_map,
.sotype = SOCK_STREAM,
.connect_to = { EXT_IP6, EXT_PORT },
.listen_at = { INT_IP6, INT_PORT },
.accept_on = SERVER_B,
},
{
.desc = "TCP IPv6 redir skip reuseport",
.lookup_prog = skel->progs.select_sock_a_no_reuseport,
.reuseport_prog = skel->progs.select_sock_b,
.sock_map = skel->maps.redir_map,
.sotype = SOCK_STREAM,
.connect_to = { EXT_IP6, EXT_PORT },
.listen_at = { INT_IP6, INT_PORT },
.accept_on = SERVER_A,
},
{
.desc = "UDP IPv4 redir port",
.lookup_prog = skel->progs.redir_port,
.sock_map = skel->maps.redir_map,
.sotype = SOCK_DGRAM,
.connect_to = { EXT_IP4, EXT_PORT },
.listen_at = { EXT_IP4, INT_PORT },
},
{
.desc = "UDP IPv4 redir addr",
.lookup_prog = skel->progs.redir_ip4,
.sock_map = skel->maps.redir_map,
.sotype = SOCK_DGRAM,
.connect_to = { EXT_IP4, EXT_PORT },
.listen_at = { INT_IP4, EXT_PORT },
},
{
.desc = "UDP IPv4 redir with reuseport",
.lookup_prog = skel->progs.select_sock_a,
.reuseport_prog = skel->progs.select_sock_b,
.sock_map = skel->maps.redir_map,
.sotype = SOCK_DGRAM,
.connect_to = { EXT_IP4, EXT_PORT },
.listen_at = { INT_IP4, INT_PORT },
.accept_on = SERVER_B,
},
{
.desc = "UDP IPv4 redir and reuseport with conns",
.lookup_prog = skel->progs.select_sock_a,
.reuseport_prog = skel->progs.select_sock_b,
.sock_map = skel->maps.redir_map,
.sotype = SOCK_DGRAM,
.connect_to = { EXT_IP4, EXT_PORT },
.listen_at = { INT_IP4, INT_PORT },
.accept_on = SERVER_B,
.reuseport_has_conns = true,
},
{
.desc = "UDP IPv4 redir skip reuseport",
.lookup_prog = skel->progs.select_sock_a_no_reuseport,
.reuseport_prog = skel->progs.select_sock_b,
.sock_map = skel->maps.redir_map,
.sotype = SOCK_DGRAM,
.connect_to = { EXT_IP4, EXT_PORT },
.listen_at = { INT_IP4, INT_PORT },
.accept_on = SERVER_A,
},
{
.desc = "UDP IPv6 redir port",
.lookup_prog = skel->progs.redir_port,
.sock_map = skel->maps.redir_map,
.sotype = SOCK_DGRAM,
.connect_to = { EXT_IP6, EXT_PORT },
.listen_at = { EXT_IP6, INT_PORT },
},
{
.desc = "UDP IPv6 redir addr",
.lookup_prog = skel->progs.redir_ip6,
.sock_map = skel->maps.redir_map,
.sotype = SOCK_DGRAM,
.connect_to = { EXT_IP6, EXT_PORT },
.listen_at = { INT_IP6, EXT_PORT },
},
{
.desc = "UDP IPv4->IPv6 redir port",
.lookup_prog = skel->progs.redir_port,
.sock_map = skel->maps.redir_map,
.sotype = SOCK_DGRAM,
.listen_at = { INT_IP4_V6, INT_PORT },
.connect_to = { EXT_IP4, EXT_PORT },
},
{
.desc = "UDP IPv6 redir and reuseport",
.lookup_prog = skel->progs.select_sock_a,
.reuseport_prog = skel->progs.select_sock_b,
.sock_map = skel->maps.redir_map,
.sotype = SOCK_DGRAM,
.connect_to = { EXT_IP6, EXT_PORT },
.listen_at = { INT_IP6, INT_PORT },
.accept_on = SERVER_B,
},
{
.desc = "UDP IPv6 redir and reuseport with conns",
.lookup_prog = skel->progs.select_sock_a,
.reuseport_prog = skel->progs.select_sock_b,
.sock_map = skel->maps.redir_map,
.sotype = SOCK_DGRAM,
.connect_to = { EXT_IP6, EXT_PORT },
.listen_at = { INT_IP6, INT_PORT },
.accept_on = SERVER_B,
.reuseport_has_conns = true,
},
{
.desc = "UDP IPv6 redir skip reuseport",
.lookup_prog = skel->progs.select_sock_a_no_reuseport,
.reuseport_prog = skel->progs.select_sock_b,
.sock_map = skel->maps.redir_map,
.sotype = SOCK_DGRAM,
.connect_to = { EXT_IP6, EXT_PORT },
.listen_at = { INT_IP6, INT_PORT },
.accept_on = SERVER_A,
},
};
const struct test *t;
for (t = tests; t < tests + ARRAY_SIZE(tests); t++) {
if (test__start_subtest(t->desc))
run_lookup_prog(t);
}
}
static void drop_on_lookup(const struct test *t)
{
struct sockaddr_storage dst = {};
int client_fd, server_fd, err;
struct bpf_link *lookup_link;
ssize_t n;
lookup_link = attach_lookup_prog(t->lookup_prog);
if (!lookup_link)
return;
server_fd = make_server(t->sotype, t->listen_at.ip, t->listen_at.port,
t->reuseport_prog);
if (server_fd < 0)
goto detach;
client_fd = make_socket(t->sotype, t->connect_to.ip,
t->connect_to.port, &dst);
if (client_fd < 0)
goto close_srv;
err = connect(client_fd, (void *)&dst, inetaddr_len(&dst));
if (t->sotype == SOCK_DGRAM) {
err = send_byte(client_fd);
if (err)
goto close_all;
/* Read out asynchronous error */
n = recv(client_fd, NULL, 0, 0);
err = n == -1;
}
if (CHECK(!err || errno != ECONNREFUSED, "connect",
"unexpected success or error\n"))
log_err("expected ECONNREFUSED on connect");
close_all:
close(client_fd);
close_srv:
close(server_fd);
detach:
bpf_link__destroy(lookup_link);
}
static void test_drop_on_lookup(struct test_sk_lookup *skel)
{
const struct test tests[] = {
{
.desc = "TCP IPv4 drop on lookup",
.lookup_prog = skel->progs.lookup_drop,
.sotype = SOCK_STREAM,
.connect_to = { EXT_IP4, EXT_PORT },
.listen_at = { EXT_IP4, EXT_PORT },
},
{
.desc = "TCP IPv6 drop on lookup",
.lookup_prog = skel->progs.lookup_drop,
.sotype = SOCK_STREAM,
.connect_to = { EXT_IP6, EXT_PORT },
.listen_at = { EXT_IP6, EXT_PORT },
},
{
.desc = "UDP IPv4 drop on lookup",
.lookup_prog = skel->progs.lookup_drop,
.sotype = SOCK_DGRAM,
.connect_to = { EXT_IP4, EXT_PORT },
.listen_at = { EXT_IP4, EXT_PORT },
},
{
.desc = "UDP IPv6 drop on lookup",
.lookup_prog = skel->progs.lookup_drop,
.sotype = SOCK_DGRAM,
.connect_to = { EXT_IP6, EXT_PORT },
.listen_at = { EXT_IP6, INT_PORT },
},
/* The program will drop on success, meaning that the ifindex
* was 1.
*/
{
.desc = "TCP IPv4 drop on valid ifindex",
.lookup_prog = skel->progs.check_ifindex,
.sotype = SOCK_STREAM,
.connect_to = { EXT_IP4, EXT_PORT },
.listen_at = { EXT_IP4, EXT_PORT },
},
{
.desc = "TCP IPv6 drop on valid ifindex",
.lookup_prog = skel->progs.check_ifindex,
.sotype = SOCK_STREAM,
.connect_to = { EXT_IP6, EXT_PORT },
.listen_at = { EXT_IP6, EXT_PORT },
},
{
.desc = "UDP IPv4 drop on valid ifindex",
.lookup_prog = skel->progs.check_ifindex,
.sotype = SOCK_DGRAM,
.connect_to = { EXT_IP4, EXT_PORT },
.listen_at = { EXT_IP4, EXT_PORT },
},
{
.desc = "UDP IPv6 drop on valid ifindex",
.lookup_prog = skel->progs.check_ifindex,
.sotype = SOCK_DGRAM,
.connect_to = { EXT_IP6, EXT_PORT },
.listen_at = { EXT_IP6, EXT_PORT },
},
};
const struct test *t;
for (t = tests; t < tests + ARRAY_SIZE(tests); t++) {
if (test__start_subtest(t->desc))
drop_on_lookup(t);
}
}
static void drop_on_reuseport(const struct test *t)
{
struct sockaddr_storage dst = { 0 };
int client, server1, server2, err;
struct bpf_link *lookup_link;
ssize_t n;
lookup_link = attach_lookup_prog(t->lookup_prog);
if (!lookup_link)
return;
server1 = make_server(t->sotype, t->listen_at.ip, t->listen_at.port,
t->reuseport_prog);
if (server1 < 0)
goto detach;
err = update_lookup_map(t->sock_map, SERVER_A, server1);
if (err)
goto close_srv1;
/* second server on destination address we should never reach */
server2 = make_server(t->sotype, t->connect_to.ip, t->connect_to.port,
NULL /* reuseport prog */);
if (server2 < 0)
goto close_srv1;
client = make_socket(t->sotype, t->connect_to.ip,
t->connect_to.port, &dst);
if (client < 0)
goto close_srv2;
err = connect(client, (void *)&dst, inetaddr_len(&dst));
if (t->sotype == SOCK_DGRAM) {
err = send_byte(client);
if (err)
goto close_all;
/* Read out asynchronous error */
n = recv(client, NULL, 0, 0);
err = n == -1;
}
if (CHECK(!err || errno != ECONNREFUSED, "connect",
"unexpected success or error\n"))
log_err("expected ECONNREFUSED on connect");
close_all:
close(client);
close_srv2:
close(server2);
close_srv1:
close(server1);
detach:
bpf_link__destroy(lookup_link);
}
static void test_drop_on_reuseport(struct test_sk_lookup *skel)
{
const struct test tests[] = {
{
.desc = "TCP IPv4 drop on reuseport",
.lookup_prog = skel->progs.select_sock_a,
.reuseport_prog = skel->progs.reuseport_drop,
.sock_map = skel->maps.redir_map,
.sotype = SOCK_STREAM,
.connect_to = { EXT_IP4, EXT_PORT },
.listen_at = { INT_IP4, INT_PORT },
},
{
.desc = "TCP IPv6 drop on reuseport",
.lookup_prog = skel->progs.select_sock_a,
.reuseport_prog = skel->progs.reuseport_drop,
.sock_map = skel->maps.redir_map,
.sotype = SOCK_STREAM,
.connect_to = { EXT_IP6, EXT_PORT },
.listen_at = { INT_IP6, INT_PORT },
},
{
.desc = "UDP IPv4 drop on reuseport",
.lookup_prog = skel->progs.select_sock_a,
.reuseport_prog = skel->progs.reuseport_drop,
.sock_map = skel->maps.redir_map,
.sotype = SOCK_DGRAM,
.connect_to = { EXT_IP4, EXT_PORT },
.listen_at = { INT_IP4, INT_PORT },
},
{
.desc = "TCP IPv6 drop on reuseport",
.lookup_prog = skel->progs.select_sock_a,
.reuseport_prog = skel->progs.reuseport_drop,
.sock_map = skel->maps.redir_map,
.sotype = SOCK_STREAM,
.connect_to = { EXT_IP6, EXT_PORT },
.listen_at = { INT_IP6, INT_PORT },
},
};
const struct test *t;
for (t = tests; t < tests + ARRAY_SIZE(tests); t++) {
if (test__start_subtest(t->desc))
drop_on_reuseport(t);
}
}
static void run_sk_assign(struct test_sk_lookup *skel,
struct bpf_program *lookup_prog,
const char *remote_ip, const char *local_ip)
{
int server_fds[] = { [0 ... MAX_SERVERS - 1] = -1 };
struct bpf_sk_lookup ctx;
__u64 server_cookie;
int i, err;
DECLARE_LIBBPF_OPTS(bpf_test_run_opts, opts,
.ctx_in = &ctx,
.ctx_size_in = sizeof(ctx),
.ctx_out = &ctx,
.ctx_size_out = sizeof(ctx),
);
if (fill_sk_lookup_ctx(&ctx, local_ip, EXT_PORT, remote_ip, INT_PORT))
return;
ctx.protocol = IPPROTO_TCP;
for (i = 0; i < ARRAY_SIZE(server_fds); i++) {
server_fds[i] = make_server(SOCK_STREAM, local_ip, 0, NULL);
if (server_fds[i] < 0)
goto close_servers;
err = update_lookup_map(skel->maps.redir_map, i,
server_fds[i]);
if (err)
goto close_servers;
}
server_cookie = socket_cookie(server_fds[SERVER_B]);
if (!server_cookie)
return;
err = bpf_prog_test_run_opts(bpf_program__fd(lookup_prog), &opts);
if (CHECK(err, "test_run", "failed with error %d\n", errno))
goto close_servers;
if (CHECK(ctx.cookie == 0, "ctx.cookie", "no socket selected\n"))
goto close_servers;
CHECK(ctx.cookie != server_cookie, "ctx.cookie",
"selected sk %llu instead of %llu\n", ctx.cookie, server_cookie);
close_servers:
for (i = 0; i < ARRAY_SIZE(server_fds); i++) {
if (server_fds[i] != -1)
close(server_fds[i]);
}
}
static void run_sk_assign_v4(struct test_sk_lookup *skel,
struct bpf_program *lookup_prog)
{
run_sk_assign(skel, lookup_prog, INT_IP4, EXT_IP4);
}
static void run_sk_assign_v6(struct test_sk_lookup *skel,
struct bpf_program *lookup_prog)
{
run_sk_assign(skel, lookup_prog, INT_IP6, EXT_IP6);
}
static void run_sk_assign_connected(struct test_sk_lookup *skel,
int sotype)
{
int err, client_fd, connected_fd, server_fd;
struct bpf_link *lookup_link;
server_fd = make_server(sotype, EXT_IP4, EXT_PORT, NULL);
if (server_fd < 0)
return;
connected_fd = make_client(sotype, EXT_IP4, EXT_PORT);
if (connected_fd < 0)
goto out_close_server;
/* Put a connected socket in redirect map */
err = update_lookup_map(skel->maps.redir_map, SERVER_A, connected_fd);
if (err)
goto out_close_connected;
lookup_link = attach_lookup_prog(skel->progs.sk_assign_esocknosupport);
if (!lookup_link)
goto out_close_connected;
/* Try to redirect TCP SYN / UDP packet to a connected socket */
client_fd = make_client(sotype, EXT_IP4, EXT_PORT);
if (client_fd < 0)
goto out_unlink_prog;
if (sotype == SOCK_DGRAM) {
send_byte(client_fd);
recv_byte(server_fd);
}
close(client_fd);
out_unlink_prog:
bpf_link__destroy(lookup_link);
out_close_connected:
close(connected_fd);
out_close_server:
close(server_fd);
}
static void test_sk_assign_helper(struct test_sk_lookup *skel)
{
if (test__start_subtest("sk_assign returns EEXIST"))
run_sk_assign_v4(skel, skel->progs.sk_assign_eexist);
if (test__start_subtest("sk_assign honors F_REPLACE"))
run_sk_assign_v4(skel, skel->progs.sk_assign_replace_flag);
if (test__start_subtest("sk_assign accepts NULL socket"))
run_sk_assign_v4(skel, skel->progs.sk_assign_null);
if (test__start_subtest("access ctx->sk"))
run_sk_assign_v4(skel, skel->progs.access_ctx_sk);
if (test__start_subtest("narrow access to ctx v4"))
run_sk_assign_v4(skel, skel->progs.ctx_narrow_access);
if (test__start_subtest("narrow access to ctx v6"))
run_sk_assign_v6(skel, skel->progs.ctx_narrow_access);
if (test__start_subtest("sk_assign rejects TCP established"))
run_sk_assign_connected(skel, SOCK_STREAM);
if (test__start_subtest("sk_assign rejects UDP connected"))
run_sk_assign_connected(skel, SOCK_DGRAM);
}
struct test_multi_prog {
const char *desc;
struct bpf_program *prog1;
struct bpf_program *prog2;
struct bpf_map *redir_map;
struct bpf_map *run_map;
int expect_errno;
struct inet_addr listen_at;
};
static void run_multi_prog_lookup(const struct test_multi_prog *t)
{
struct sockaddr_storage dst = {};
int map_fd, server_fd, client_fd;
struct bpf_link *link1, *link2;
int prog_idx, done, err;
map_fd = bpf_map__fd(t->run_map);
done = 0;
prog_idx = PROG1;
err = bpf_map_update_elem(map_fd, &prog_idx, &done, BPF_ANY);
if (CHECK(err, "bpf_map_update_elem", "failed\n"))
return;
prog_idx = PROG2;
err = bpf_map_update_elem(map_fd, &prog_idx, &done, BPF_ANY);
if (CHECK(err, "bpf_map_update_elem", "failed\n"))
return;
link1 = attach_lookup_prog(t->prog1);
if (!link1)
return;
link2 = attach_lookup_prog(t->prog2);
if (!link2)
goto out_unlink1;
server_fd = make_server(SOCK_STREAM, t->listen_at.ip,
t->listen_at.port, NULL);
if (server_fd < 0)
goto out_unlink2;
err = update_lookup_map(t->redir_map, SERVER_A, server_fd);
if (err)
goto out_close_server;
client_fd = make_socket(SOCK_STREAM, EXT_IP4, EXT_PORT, &dst);
if (client_fd < 0)
goto out_close_server;
err = connect(client_fd, (void *)&dst, inetaddr_len(&dst));
if (CHECK(err && !t->expect_errno, "connect",
"unexpected error %d\n", errno))
goto out_close_client;
if (CHECK(err && t->expect_errno && errno != t->expect_errno,
"connect", "unexpected error %d\n", errno))
goto out_close_client;
done = 0;
prog_idx = PROG1;
err = bpf_map_lookup_elem(map_fd, &prog_idx, &done);
CHECK(err, "bpf_map_lookup_elem", "failed\n");
CHECK(!done, "bpf_map_lookup_elem", "PROG1 !done\n");
done = 0;
prog_idx = PROG2;
err = bpf_map_lookup_elem(map_fd, &prog_idx, &done);
CHECK(err, "bpf_map_lookup_elem", "failed\n");
CHECK(!done, "bpf_map_lookup_elem", "PROG2 !done\n");
out_close_client:
close(client_fd);
out_close_server:
close(server_fd);
out_unlink2:
bpf_link__destroy(link2);
out_unlink1:
bpf_link__destroy(link1);
}
static void test_multi_prog_lookup(struct test_sk_lookup *skel)
{
struct test_multi_prog tests[] = {
{
.desc = "multi prog - pass, pass",
.prog1 = skel->progs.multi_prog_pass1,
.prog2 = skel->progs.multi_prog_pass2,
.listen_at = { EXT_IP4, EXT_PORT },
},
{
.desc = "multi prog - drop, drop",
.prog1 = skel->progs.multi_prog_drop1,
.prog2 = skel->progs.multi_prog_drop2,
.listen_at = { EXT_IP4, EXT_PORT },
.expect_errno = ECONNREFUSED,
},
{
.desc = "multi prog - pass, drop",
.prog1 = skel->progs.multi_prog_pass1,
.prog2 = skel->progs.multi_prog_drop2,
.listen_at = { EXT_IP4, EXT_PORT },
.expect_errno = ECONNREFUSED,
},
{
.desc = "multi prog - drop, pass",
.prog1 = skel->progs.multi_prog_drop1,
.prog2 = skel->progs.multi_prog_pass2,
.listen_at = { EXT_IP4, EXT_PORT },
.expect_errno = ECONNREFUSED,
},
{
.desc = "multi prog - pass, redir",
.prog1 = skel->progs.multi_prog_pass1,
.prog2 = skel->progs.multi_prog_redir2,
.listen_at = { INT_IP4, INT_PORT },
},
{
.desc = "multi prog - redir, pass",
.prog1 = skel->progs.multi_prog_redir1,
.prog2 = skel->progs.multi_prog_pass2,
.listen_at = { INT_IP4, INT_PORT },
},
{
.desc = "multi prog - drop, redir",
.prog1 = skel->progs.multi_prog_drop1,
.prog2 = skel->progs.multi_prog_redir2,
.listen_at = { INT_IP4, INT_PORT },
},
{
.desc = "multi prog - redir, drop",
.prog1 = skel->progs.multi_prog_redir1,
.prog2 = skel->progs.multi_prog_drop2,
.listen_at = { INT_IP4, INT_PORT },
},
{
.desc = "multi prog - redir, redir",
.prog1 = skel->progs.multi_prog_redir1,
.prog2 = skel->progs.multi_prog_redir2,
.listen_at = { INT_IP4, INT_PORT },
},
};
struct test_multi_prog *t;
for (t = tests; t < tests + ARRAY_SIZE(tests); t++) {
t->redir_map = skel->maps.redir_map;
t->run_map = skel->maps.run_map;
if (test__start_subtest(t->desc))
run_multi_prog_lookup(t);
}
}
static void run_tests(struct test_sk_lookup *skel)
{
if (test__start_subtest("query lookup prog"))
query_lookup_prog(skel);
test_redirect_lookup(skel);
test_drop_on_lookup(skel);
test_drop_on_reuseport(skel);
test_sk_assign_helper(skel);
test_multi_prog_lookup(skel);
}
static int switch_netns(void)
{
static const char * const setup_script[] = {
"ip -6 addr add dev lo " EXT_IP6 "/128",
"ip -6 addr add dev lo " INT_IP6 "/128",
"ip link set dev lo up",
NULL,
};
const char * const *cmd;
int err;
err = unshare(CLONE_NEWNET);
if (CHECK(err, "unshare", "failed\n")) {
log_err("unshare(CLONE_NEWNET)");
return -1;
}
for (cmd = setup_script; *cmd; cmd++) {
err = system(*cmd);
if (CHECK(err, "system", "failed\n")) {
log_err("system(%s)", *cmd);
return -1;
}
}
return 0;
}
void test_sk_lookup(void)
{
struct test_sk_lookup *skel;
int err;
err = switch_netns();
if (err)
return;
skel = test_sk_lookup__open_and_load();
if (CHECK(!skel, "skel open_and_load", "failed\n"))
return;
run_tests(skel);
test_sk_lookup__destroy(skel);
}
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