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// SPDX-License-Identifier: LGPL-2.1 OR BSD-2-Clause
/* Copyright (c) 2022, NVIDIA CORPORATION & AFFILIATES. All rights reserved. */
#define _GNU_SOURCE
#include <test_progs.h>
#include <network_helpers.h>
#include <ctype.h>
#define CMD_OUT_BUF_SIZE 1023
#define SYS(cmd) ({ \
if (!ASSERT_OK(system(cmd), (cmd))) \
goto out; \
})
#define SYS_OUT(cmd, ...) ({ \
char buf[1024]; \
snprintf(buf, sizeof(buf), (cmd), ##__VA_ARGS__); \
FILE *f = popen(buf, "r"); \
if (!ASSERT_OK_PTR(f, buf)) \
goto out; \
f; \
})
/* out must be at least `size * 4 + 1` bytes long */
static void escape_str(char *out, const char *in, size_t size)
{
static const char *hex = "0123456789ABCDEF";
size_t i;
for (i = 0; i < size; i++) {
if (isprint(in[i]) && in[i] != '\\' && in[i] != '\'') {
*out++ = in[i];
} else {
*out++ = '\\';
*out++ = 'x';
*out++ = hex[(in[i] >> 4) & 0xf];
*out++ = hex[in[i] & 0xf];
}
}
*out++ = '\0';
}
static bool expect_str(char *buf, size_t size, const char *str, const char *name)
{
static char escbuf_expected[CMD_OUT_BUF_SIZE * 4];
static char escbuf_actual[CMD_OUT_BUF_SIZE * 4];
static int duration = 0;
bool ok;
ok = size == strlen(str) && !memcmp(buf, str, size);
if (!ok) {
escape_str(escbuf_expected, str, strlen(str));
escape_str(escbuf_actual, buf, size);
}
CHECK(!ok, name, "unexpected %s: actual '%s' != expected '%s'\n",
name, escbuf_actual, escbuf_expected);
return ok;
}
static void test_synproxy(bool xdp)
{
int server_fd = -1, client_fd = -1, accept_fd = -1;
char *prog_id = NULL, *prog_id_end;
struct nstoken *ns = NULL;
FILE *ctrl_file = NULL;
char buf[CMD_OUT_BUF_SIZE];
size_t size;
SYS("ip netns add synproxy");
SYS("ip link add tmp0 type veth peer name tmp1");
SYS("ip link set tmp1 netns synproxy");
SYS("ip link set tmp0 up");
SYS("ip addr replace 198.18.0.1/24 dev tmp0");
/* When checksum offload is enabled, the XDP program sees wrong
* checksums and drops packets.
*/
SYS("ethtool -K tmp0 tx off");
if (xdp)
/* Workaround required for veth. */
SYS("ip link set tmp0 xdp object xdp_dummy.bpf.o section xdp 2> /dev/null");
ns = open_netns("synproxy");
if (!ASSERT_OK_PTR(ns, "setns"))
goto out;
SYS("ip link set lo up");
SYS("ip link set tmp1 up");
SYS("ip addr replace 198.18.0.2/24 dev tmp1");
SYS("sysctl -w net.ipv4.tcp_syncookies=2");
SYS("sysctl -w net.ipv4.tcp_timestamps=1");
SYS("sysctl -w net.netfilter.nf_conntrack_tcp_loose=0");
SYS("iptables -t raw -I PREROUTING \
-i tmp1 -p tcp -m tcp --syn --dport 8080 -j CT --notrack");
SYS("iptables -t filter -A INPUT \
-i tmp1 -p tcp -m tcp --dport 8080 -m state --state INVALID,UNTRACKED \
-j SYNPROXY --sack-perm --timestamp --wscale 7 --mss 1460");
SYS("iptables -t filter -A INPUT \
-i tmp1 -m state --state INVALID -j DROP");
ctrl_file = SYS_OUT("./xdp_synproxy --iface tmp1 --ports 8080 \
--single --mss4 1460 --mss6 1440 \
--wscale 7 --ttl 64%s", xdp ? "" : " --tc");
size = fread(buf, 1, sizeof(buf), ctrl_file);
pclose(ctrl_file);
if (!expect_str(buf, size, "Total SYNACKs generated: 0\n",
"initial SYNACKs"))
goto out;
if (!xdp) {
ctrl_file = SYS_OUT("tc filter show dev tmp1 ingress");
size = fread(buf, 1, sizeof(buf), ctrl_file);
pclose(ctrl_file);
prog_id = memmem(buf, size, " id ", 4);
if (!ASSERT_OK_PTR(prog_id, "find prog id"))
goto out;
prog_id += 4;
if (!ASSERT_LT(prog_id, buf + size, "find prog id begin"))
goto out;
prog_id_end = prog_id;
while (prog_id_end < buf + size && *prog_id_end >= '0' &&
*prog_id_end <= '9')
prog_id_end++;
if (!ASSERT_LT(prog_id_end, buf + size, "find prog id end"))
goto out;
*prog_id_end = '\0';
}
server_fd = start_server(AF_INET, SOCK_STREAM, "198.18.0.2", 8080, 0);
if (!ASSERT_GE(server_fd, 0, "start_server"))
goto out;
close_netns(ns);
ns = NULL;
client_fd = connect_to_fd(server_fd, 10000);
if (!ASSERT_GE(client_fd, 0, "connect_to_fd"))
goto out;
accept_fd = accept(server_fd, NULL, NULL);
if (!ASSERT_GE(accept_fd, 0, "accept"))
goto out;
ns = open_netns("synproxy");
if (!ASSERT_OK_PTR(ns, "setns"))
goto out;
if (xdp)
ctrl_file = SYS_OUT("./xdp_synproxy --iface tmp1 --single");
else
ctrl_file = SYS_OUT("./xdp_synproxy --prog %s --single",
prog_id);
size = fread(buf, 1, sizeof(buf), ctrl_file);
pclose(ctrl_file);
if (!expect_str(buf, size, "Total SYNACKs generated: 1\n",
"SYNACKs after connection"))
goto out;
out:
if (accept_fd >= 0)
close(accept_fd);
if (client_fd >= 0)
close(client_fd);
if (server_fd >= 0)
close(server_fd);
if (ns)
close_netns(ns);
system("ip link del tmp0");
system("ip netns del synproxy");
}
void test_xdp_synproxy(void)
{
if (test__start_subtest("xdp"))
test_synproxy(true);
if (test__start_subtest("tc"))
test_synproxy(false);
}
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