[PATCH v7 20/26] selftests: nettest: Initial tcp_authopt support

From: Leonard Crestez
Date: Thu Aug 18 2022 - 16:03:19 EST


Add support for configuring TCP Authentication Option. Only a single key
is supported with default options.

Reviewed-by: David Ahern <dsahern@xxxxxxxxxx>
Signed-off-by: Leonard Crestez <cdleonard@xxxxxxxxx>
---
tools/testing/selftests/net/nettest.c | 156 ++++++++++++++++++++++++--
1 file changed, 145 insertions(+), 11 deletions(-)

diff --git a/tools/testing/selftests/net/nettest.c b/tools/testing/selftests/net/nettest.c
index 3841e5fec7c7..9615489230f8 100644
--- a/tools/testing/selftests/net/nettest.c
+++ b/tools/testing/selftests/net/nettest.c
@@ -27,10 +27,11 @@
#include <string.h>
#include <unistd.h>
#include <time.h>
#include <errno.h>
#include <getopt.h>
+#include <stdbool.h>

#include <linux/xfrm.h>
#include <linux/ipsec.h>
#include <linux/pfkeyv2.h>

@@ -104,10 +105,12 @@ struct sock_args {
} key_addr;
unsigned int key_addr_prefix_len;
/* 0: default, -1: force off, +1: force on */
int bind_key_ifindex;

+ const char *authopt_password;
+
/* expected addresses and device index for connection */
const char *expected_dev;
const char *expected_server_dev;
int expected_ifindex;

@@ -254,10 +257,75 @@ static int switch_ns(const char *ns)
close(fd);

return ret;
}

+/* Fill key identification fields: address and ifindex */
+static void tcp_authopt_key_fill_id(struct tcp_authopt_key *key, struct sock_args *args)
+{
+ if (args->key_addr_prefix_str) {
+ key->flags |= TCP_AUTHOPT_KEY_ADDR_BIND;
+ switch (args->version) {
+ case AF_INET:
+ memcpy(&key->addr, &args->key_addr.v4, sizeof(args->key_addr.v4));
+ break;
+ case AF_INET6:
+ memcpy(&key->addr, &args->key_addr.v6, sizeof(args->key_addr.v6));
+ break;
+ default:
+ log_error("unknown address family\n");
+ exit(1);
+ }
+ if (args->key_addr_prefix_len) {
+ key->flags |= TCP_AUTHOPT_KEY_PREFIXLEN;
+ key->prefixlen = args->key_addr_prefix_len;
+ }
+ }
+
+ if ((args->ifindex && args->bind_key_ifindex >= 0) || args->bind_key_ifindex >= 1) {
+ key->flags |= TCP_AUTHOPT_KEY_IFINDEX;
+ key->ifindex = args->ifindex;
+ log_msg("TCP_AUTHOPT_KEY_IFINDEX set ifindex=%d\n", key->ifindex);
+ } else {
+ log_msg("TCP_AUTHOPT_KEY_IFINDEX off\n", key->ifindex);
+ }
+}
+
+static int tcp_del_authopt(int sd, struct sock_args *args)
+{
+ struct tcp_authopt_key key;
+ int rc;
+
+ memset(&key, 0, sizeof(key));
+ key.flags |= TCP_AUTHOPT_KEY_DEL;
+ tcp_authopt_key_fill_id(&key, args);
+
+ rc = setsockopt(sd, IPPROTO_TCP, TCP_AUTHOPT_KEY, &key, sizeof(key));
+ if (rc < 0)
+ log_err_errno("setsockopt(TCP_AUTHOPT_KEY) del fail");
+
+ return rc;
+}
+
+static int tcp_set_authopt(int sd, struct sock_args *args)
+{
+ struct tcp_authopt_key key;
+ int rc;
+
+ memset(&key, 0, sizeof(key));
+ strcpy((char *)key.key, args->authopt_password);
+ key.keylen = strlen(args->authopt_password);
+ key.alg = TCP_AUTHOPT_ALG_HMAC_SHA_1_96;
+ tcp_authopt_key_fill_id(&key, args);
+
+ rc = setsockopt(sd, IPPROTO_TCP, TCP_AUTHOPT_KEY, &key, sizeof(key));
+ if (rc < 0)
+ log_err_errno("setsockopt(TCP_AUTHOPT_KEY) add fail");
+
+ return rc;
+}
+
static int tcp_md5sig(int sd, void *addr, socklen_t alen, struct sock_args *args)
{
int keylen = strlen(args->password);
struct tcp_md5sig md5sig = {};
int opt = TCP_MD5SIG;
@@ -1541,10 +1609,15 @@ static int do_server(struct sock_args *args, int ipc_fd)
if (args->password && tcp_md5_remote(lsd, args)) {
close(lsd);
goto err_exit;
}

+ if (args->authopt_password && tcp_set_authopt(lsd, args)) {
+ close(lsd);
+ goto err_exit;
+ }
+
ipc_write(ipc_fd, 1);
while (1) {
log_msg("waiting for client connection.\n");
FD_ZERO(&rfds);
FD_SET(lsd, &rfds);
@@ -1663,10 +1736,13 @@ static int connectsock(void *addr, socklen_t alen, struct sock_args *args)
goto out;

if (args->password && tcp_md5sig(sd, addr, alen, args))
goto err;

+ if (args->authopt_password && tcp_set_authopt(sd, args))
+ goto err;
+
if (args->bind_test_only)
goto out;

if (connect(sd, addr, alen) < 0) {
if (errno != EINPROGRESS) {
@@ -1852,11 +1928,11 @@ static int ipc_parent(int cpid, int fd, struct sock_args *args)

wait(&status);
return client_status;
}

-#define GETOPT_STR "sr:l:c:p:t:g:P:DRn:M:X:m:d:I:BN:O:SCi6xL:0:1:2:3:Fbqf"
+#define GETOPT_STR "sr:l:c:p:t:g:P:DRn:M:X:m:A:d:I:BN:O:SCi6xL:0:1:2:3:Fbqf"
#define OPT_FORCE_BIND_KEY_IFINDEX 1001
#define OPT_NO_BIND_KEY_IFINDEX 1002

static struct option long_opts[] = {
{"force-bind-key-ifindex", 0, 0, OPT_FORCE_BIND_KEY_IFINDEX},
@@ -1897,14 +1973,15 @@ static void print_usage(char *prog)
" -L len send random message of given length\n"
" -n num number of times to send message\n"
"\n"
" -M password use MD5 sum protection\n"
" -X password MD5 password for client mode\n"
- " -m prefix/len prefix and length to use for MD5 key\n"
- " --no-bind-key-ifindex: Force TCP_MD5SIG_FLAG_IFINDEX off\n"
- " --force-bind-key-ifindex: Force TCP_MD5SIG_FLAG_IFINDEX on\n"
+ " -m prefix/len prefix and length to use for MD5/AO key\n"
+ " --no-bind-key-ifindex: Force disable binding key to ifindex\n"
+ " --force-bind-key-ifindex: Force enable binding key to ifindex\n"
" (default: only if -I is passed)\n"
+ " -A password use RFC5925 TCP Authentication Option with password\n"
"\n"
" -g grp multicast group (e.g., 239.1.1.1)\n"
" -i interactive mode (default is echo and terminate)\n"
"\n"
" -0 addr Expected local address\n"
@@ -1915,17 +1992,64 @@ static void print_usage(char *prog)
" -b Bind test only.\n"
" -q Be quiet. Run test without printing anything.\n"
, prog, DEFAULT_PORT);
}

-int main(int argc, char *argv[])
+/* Needs explicit cleanup because keys are global per-namespace */
+void cleanup_tcp_authopt(struct sock_args *args)
+{
+ int fd;
+
+ if (!args->authopt_password)
+ return;
+
+ fd = socket(AF_INET, SOCK_STREAM, 0);
+ if (fd < 0) {
+ log_err_errno("Failed to create socket");
+ return;
+ }
+ tcp_del_authopt(fd, args);
+ close(fd);
+}
+
+static bool cleanup_done;
+static struct sock_args args = {
+ .version = AF_INET,
+ .type = SOCK_STREAM,
+ .port = DEFAULT_PORT,
+};
+
+void cleanup(void)
+{
+ if (cleanup_done)
+ return;
+ cleanup_done = true;
+ cleanup_tcp_authopt(&args);
+}
+
+void signal_handler(int num)
+{
+ cleanup();
+}
+
+void atexit_handler(void)
+{
+ cleanup();
+}
+
+/* Explicit cleanup is required for TCP-AO because keys are global. */
+static void register_cleanup(void)
{
- struct sock_args args = {
- .version = AF_INET,
- .type = SOCK_STREAM,
- .port = DEFAULT_PORT,
+ struct sigaction sa = {
+ .sa_handler = signal_handler,
};
+ sigaction(SIGINT, &sa, NULL);
+ atexit(atexit_handler);
+}
+
+int main(int argc, char *argv[])
+{
struct protoent *pe;
int both_mode = 0;
unsigned int tmp;
int forever = 0;
int fd[2];
@@ -2022,10 +2146,13 @@ int main(int argc, char *argv[])
args.client_pw = optarg;
break;
case 'm':
args.key_addr_prefix_str = optarg;
break;
+ case 'A':
+ args.authopt_password = optarg;
+ break;
case 'S':
args.use_setsockopt = 1;
break;
case 'f':
args.use_freebind = 1;
@@ -2085,12 +2212,17 @@ int main(int argc, char *argv[])
args.type != SOCK_STREAM)) {
log_error("MD5 passwords apply to TCP only and require a remote ip for the password\n");
return 1;
}

- if (args.key_addr_prefix_str && !args.password) {
- log_error("Prefix range for MD5 protection specified without a password\n");
+ if (args.key_addr_prefix_str && !args.password && !args.authopt_password) {
+ log_error("Prefix range for authentication requires -M or -A\n");
+ return 1;
+ }
+
+ if (args.key_addr_prefix_len && args.authopt_password) {
+ log_error("TCP-AO does not support prefix match, only full address\n");
return 1;
}

if (iter == 0) {
fprintf(stderr, "Invalid number of messages to send\n");
@@ -2113,10 +2245,12 @@ int main(int argc, char *argv[])
fprintf(stderr,
"Local (server mode) or remote IP (client IP) required\n");
return 1;
}

+ register_cleanup();
+
if (interactive) {
prog_timeout = 0;
msg = NULL;
}

--
2.25.1