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Message-ID: <fe2b641f-a8aa-428c-9f04-f099015e0eb9@linuxfoundation.org>
Date: Sat, 26 Oct 2024 17:40:58 -0600
From: Shuah Khan <skhan@...uxfoundation.org>
To: Antonio Quartulli <antonio@...nvpn.net>,
 Eric Dumazet <edumazet@...gle.com>, Jakub Kicinski <kuba@...nel.org>,
 Paolo Abeni <pabeni@...hat.com>, Donald Hunter <donald.hunter@...il.com>,
 Shuah Khan <shuah@...nel.org>, sd@...asysnail.net, ryazanov.s.a@...il.com,
 Andrew Lunn <andrew@...n.ch>
Cc: netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
 linux-kselftest@...r.kernel.org, Shuah Khan <skhan@...uxfoundation.org>
Subject: Re: [PATCH net-next v10 23/23] testing/selftests: add test tool and
 scripts for ovpn module

On 10/25/24 03:14, Antonio Quartulli wrote:
> The ovpn-cli tool can be compiled and used as selftest for the ovpn
> kernel module.
> 
> It implements the netlink API and can thus be integrated in any
> script for more automated testing.
> 
> Along with the tool, 4 scripts are added that perform basic
> functionality tests by means of network namespaces.
> 
> Cc: shuah@...nel.org
> Cc: linux-kselftest@...r.kernel.org
> Signed-off-by: Antonio Quartulli <antonio@...nvpn.net>
> ---
>   MAINTAINERS                                        |    1 +
>   tools/testing/selftests/Makefile                   |    1 +
>   tools/testing/selftests/net/ovpn/.gitignore        |    2 +
>   tools/testing/selftests/net/ovpn/Makefile          |   17 +
>   tools/testing/selftests/net/ovpn/config            |   10 +
>   tools/testing/selftests/net/ovpn/data64.key        |    5 +
>   tools/testing/selftests/net/ovpn/ovpn-cli.c        | 2370 ++++++++++++++++++++
>   tools/testing/selftests/net/ovpn/tcp_peers.txt     |    5 +
>   .../testing/selftests/net/ovpn/test-chachapoly.sh  |    9 +
>   tools/testing/selftests/net/ovpn/test-float.sh     |    9 +
>   tools/testing/selftests/net/ovpn/test-tcp.sh       |    9 +
>   tools/testing/selftests/net/ovpn/test.sh           |  183 ++
>   tools/testing/selftests/net/ovpn/udp_peers.txt     |    5 +
>   13 files changed, 2626 insertions(+)
> 

What does the test output look like? Add that to the change log.

> diff --git a/MAINTAINERS b/MAINTAINERS
> index cf3d55c3e98aaea8f8817faed99dd7499cd59a71..110485aec73ae5bfeef4f228490ed76e28e01870 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -17295,6 +17295,7 @@ T:	git https://github.com/OpenVPN/linux-kernel-ovpn.git
>   F:	Documentation/netlink/specs/ovpn.yaml
>   F:	drivers/net/ovpn/
>   F:	include/uapi/linux/ovpn.h
> +F:	tools/testing/selftests/net/ovpn/
>   
>   OPENVSWITCH
>   M:	Pravin B Shelar <pshelar@....org>
> diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
> index 363d031a16f7e14152c904e6b68dab1f90c98392..be42906ecb11d4b0f9866d2c04b0e8fb27a2b995 100644
> --- a/tools/testing/selftests/Makefile
> +++ b/tools/testing/selftests/Makefile
> @@ -68,6 +68,7 @@ TARGETS += net/hsr
>   TARGETS += net/mptcp
>   TARGETS += net/netfilter
>   TARGETS += net/openvswitch
> +TARGETS += net/ovpn
>   TARGETS += net/packetdrill
>   TARGETS += net/rds
>   TARGETS += net/tcp_ao
> diff --git a/tools/testing/selftests/net/ovpn/.gitignore b/tools/testing/selftests/net/ovpn/.gitignore
> new file mode 100644
> index 0000000000000000000000000000000000000000..ee44c081ca7c089933659689303c303a9fa9713b
> --- /dev/null
> +++ b/tools/testing/selftests/net/ovpn/.gitignore
> @@ -0,0 +1,2 @@
> +# SPDX-License-Identifier: GPL-2.0+
> +ovpn-cli
> diff --git a/tools/testing/selftests/net/ovpn/Makefile b/tools/testing/selftests/net/ovpn/Makefile
> new file mode 100644
> index 0000000000000000000000000000000000000000..c76d8fd953c5674941c8c2787813063b1bce180f
> --- /dev/null
> +++ b/tools/testing/selftests/net/ovpn/Makefile
> @@ -0,0 +1,17 @@
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (C) 2020-2024 OpenVPN, Inc.
> +#
> +CFLAGS = -pedantic -Wextra -Wall -Wl,--no-as-needed -g -O0 -ggdb $(KHDR_INCLUDES)
> +CFLAGS += $(shell pkg-config --cflags libnl-3.0 libnl-genl-3.0)
> +
> +LDFLAGS = -lmbedtls -lmbedcrypto
> +LDFLAGS += $(shell pkg-config --libs libnl-3.0 libnl-genl-3.0)
> +
> +TEST_PROGS = test.sh \
> +	test-chachapoly.sh \
> +	test-tcp.sh \
> +	test-float.sh
> +
> +TEST_GEN_FILES = ovpn-cli
> +
> +include ../../lib.mk
> diff --git a/tools/testing/selftests/net/ovpn/config b/tools/testing/selftests/net/ovpn/config
> new file mode 100644
> index 0000000000000000000000000000000000000000..71946ba9fa175c191725e369eb9b973503d9d9c4
> --- /dev/null
> +++ b/tools/testing/selftests/net/ovpn/config
> @@ -0,0 +1,10 @@
> +CONFIG_NET=y
> +CONFIG_INET=y
> +CONFIG_STREAM_PARSER=y
> +CONFIG_NET_UDP_TUNNEL=y
> +CONFIG_DST_CACHE=y
> +CONFIG_CRYPTO=y
> +CONFIG_CRYPTO_AES=y
> +CONFIG_CRYPTO_GCM=y
> +CONFIG_CRYPTO_CHACHA20POLY1305=y
> +CONFIG_OVPN=m
> diff --git a/tools/testing/selftests/net/ovpn/data64.key b/tools/testing/selftests/net/ovpn/data64.key
> new file mode 100644
> index 0000000000000000000000000000000000000000..a99e88c4e290f58b12f399b857b873f308d9ba09
> --- /dev/null
> +++ b/tools/testing/selftests/net/ovpn/data64.key
> @@ -0,0 +1,5 @@
> +jRqMACN7d7/aFQNT8S7jkrBD8uwrgHbG5OQZP2eu4R1Y7tfpS2bf5RHv06Vi163CGoaIiTX99R3B
> +ia9ycAH8Wz1+9PWv51dnBLur9jbShlgZ2QHLtUc4a/gfT7zZwULXuuxdLnvR21DDeMBaTbkgbai9
> +uvAa7ne1liIgGFzbv+Bas4HDVrygxIxuAnP5Qgc3648IJkZ0QEXPF+O9f0n5+QIvGCxkAUVx+5K6
> +KIs+SoeWXnAopELmoGSjUpFtJbagXK82HfdqpuUxT2Tnuef0/14SzVE/vNleBNu2ZbyrSAaah8tE
> +BofkPJUBFY+YQcfZNM5Dgrw3i+Bpmpq/gpdg5w==
> diff --git a/tools/testing/selftests/net/ovpn/ovpn-cli.c b/tools/testing/selftests/net/ovpn/ovpn-cli.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..046dd069aaaf4e5b091947bd57ed79f8519a780f
> --- /dev/null
> +++ b/tools/testing/selftests/net/ovpn/ovpn-cli.c
> @@ -0,0 +1,2370 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*  OpenVPN data channel accelerator
> + *
> + *  Copyright (C) 2020-2024 OpenVPN, Inc.
> + *
> + *  Author:	Antonio Quartulli <antonio@...nvpn.net>
> + */
> +
> +#include <stdio.h>
> +#include <inttypes.h>
> +#include <stdbool.h>
> +#include <string.h>
> +#include <errno.h>
> +#include <unistd.h>
> +#include <arpa/inet.h>
> +#include <net/if.h>
> +#include <netinet/in.h>
> +#include <time.h>
> +
> +#include <linux/ovpn.h>
> +#include <linux/types.h>
> +#include <linux/netlink.h>
> +
> +#include <netlink/socket.h>
> +#include <netlink/netlink.h>
> +#include <netlink/genl/genl.h>
> +#include <netlink/genl/family.h>
> +#include <netlink/genl/ctrl.h>
> +
> +#include <mbedtls/base64.h>
> +#include <mbedtls/error.h>
> +
> +#include <sys/socket.h>
> +
> +/* defines to make checkpatch happy */
> +#define strscpy strncpy
> +#define __always_unused __attribute__((__unused__))
> +
> +/* libnl < 3.5.0 does not set the NLA_F_NESTED on its own, therefore we
> + * have to explicitly do it to prevent the kernel from failing upon
> + * parsing of the message
> + */
> +#define nla_nest_start(_msg, _type) \
> +	nla_nest_start(_msg, (_type) | NLA_F_NESTED)
> +
> +uint64_t nla_get_uint(struct nlattr *attr)
> +{
> +	if (nla_len(attr) == sizeof(uint32_t))
> +		return nla_get_u32(attr);
> +	else
> +		return nla_get_u64(attr);
> +}
> +
> +typedef int (*ovpn_nl_cb)(struct nl_msg *msg, void *arg);
> +
> +enum ovpn_key_direction {
> +	KEY_DIR_IN = 0,
> +	KEY_DIR_OUT,
> +};
> +
> +#define KEY_LEN (256 / 8)
> +#define NONCE_LEN 8
> +
> +#define PEER_ID_UNDEF 0x00FFFFFF
> +
> +struct nl_ctx {
> +	struct nl_sock *nl_sock;
> +	struct nl_msg *nl_msg;
> +	struct nl_cb *nl_cb;
> +
> +	int ovpn_dco_id;
> +};
> +
> +enum ovpn_cmd {
> +	CMD_INVALID,
> +	CMD_NEW_IFACE,
> +	CMD_DEL_IFACE,
> +	CMD_LISTEN,
> +	CMD_CONNECT,
> +	CMD_NEW_PEER,
> +	CMD_NEW_MULTI_PEER,
> +	CMD_SET_PEER,
> +	CMD_DEL_PEER,
> +	CMD_GET_PEER,
> +	CMD_NEW_KEY,
> +	CMD_DEL_KEY,
> +	CMD_GET_KEY,
> +	CMD_SWAP_KEYS,
> +	CMD_LISTEN_MCAST,
> +};
> +
> +struct ovpn_ctx {
> +	enum ovpn_cmd cmd;
> +
> +	__u8 key_enc[KEY_LEN];
> +	__u8 key_dec[KEY_LEN];
> +	__u8 nonce[NONCE_LEN];
> +
> +	enum ovpn_cipher_alg cipher;
> +
> +	sa_family_t sa_family;
> +
> +	unsigned long peer_id;
> +	unsigned long lport;
> +
> +	union {
> +		struct sockaddr_in in4;
> +		struct sockaddr_in6 in6;
> +	} remote;
> +
> +	union {
> +		struct sockaddr_in in4;
> +		struct sockaddr_in6 in6;
> +	} peer_ip;
> +
> +	bool peer_ip_set;
> +
> +	unsigned int ifindex;
> +	char ifname[IFNAMSIZ];
> +	enum ovpn_mode mode;
> +	bool mode_set;
> +
> +	int socket;
> +	int cli_socket;
> +
> +	__u32 keepalive_interval;
> +	__u32 keepalive_timeout;
> +
> +	enum ovpn_key_direction key_dir;
> +	enum ovpn_key_slot key_slot;
> +	int key_id;
> +
> +	const char *peers_file;
> +};
> +
> +static int ovpn_nl_recvmsgs(struct nl_ctx *ctx)
> +{
> +	int ret;
> +
> +	ret = nl_recvmsgs(ctx->nl_sock, ctx->nl_cb);
> +
> +	switch (ret) {
> +	case -NLE_INTR:
> +		fprintf(stderr,
> +			"netlink received interrupt due to signal - ignoring\n");
> +		break;
> +	case -NLE_NOMEM:
> +		fprintf(stderr, "netlink out of memory error\n");
> +		break;
> +	case -NLE_AGAIN:
> +		fprintf(stderr,
> +			"netlink reports blocking read - aborting wait\n");
> +		break;
> +	default:
> +		if (ret)
> +			fprintf(stderr, "netlink reports error (%d): %s\n",
> +				ret, nl_geterror(-ret));
> +		break;
> +	}
> +
> +	return ret;
> +}
> +
> +static struct nl_ctx *nl_ctx_alloc_flags(struct ovpn_ctx *ovpn, int cmd,
> +					 int flags)
> +{
> +	struct nl_ctx *ctx;
> +	int err, ret;
> +
> +	ctx = calloc(1, sizeof(*ctx));
> +	if (!ctx)
> +		return NULL;
> +
> +	ctx->nl_sock = nl_socket_alloc();
> +	if (!ctx->nl_sock) {
> +		fprintf(stderr, "cannot allocate netlink socket\n");
> +		goto err_free;
> +	}
> +
> +	nl_socket_set_buffer_size(ctx->nl_sock, 8192, 8192);
> +
> +	ret = genl_connect(ctx->nl_sock);
> +	if (ret) {
> +		fprintf(stderr, "cannot connect to generic netlink: %s\n",
> +			nl_geterror(ret));
> +		goto err_sock;
> +	}
> +
> +	/* enable Extended ACK for detailed error reporting */
> +	err = 1;
> +	setsockopt(nl_socket_get_fd(ctx->nl_sock), SOL_NETLINK, NETLINK_EXT_ACK,
> +		   &err, sizeof(err));
> +
> +	ctx->ovpn_dco_id = genl_ctrl_resolve(ctx->nl_sock, OVPN_FAMILY_NAME);
> +	if (ctx->ovpn_dco_id < 0) {
> +		fprintf(stderr, "cannot find ovpn_dco netlink component: %d\n",
> +			ctx->ovpn_dco_id);
> +		goto err_free;
> +	}
> +
> +	ctx->nl_msg = nlmsg_alloc();
> +	if (!ctx->nl_msg) {
> +		fprintf(stderr, "cannot allocate netlink message\n");
> +		goto err_sock;
> +	}
> +
> +	ctx->nl_cb = nl_cb_alloc(NL_CB_DEFAULT);
> +	if (!ctx->nl_cb) {
> +		fprintf(stderr, "failed to allocate netlink callback\n");
> +		goto err_msg;
> +	}
> +
> +	nl_socket_set_cb(ctx->nl_sock, ctx->nl_cb);
> +
> +	genlmsg_put(ctx->nl_msg, 0, 0, ctx->ovpn_dco_id, 0, flags, cmd, 0);
> +
> +	if (ovpn->ifindex > 0)
> +		NLA_PUT_U32(ctx->nl_msg, OVPN_A_IFINDEX, ovpn->ifindex);
> +
> +	return ctx;
> +nla_put_failure:
> +err_msg:
> +	nlmsg_free(ctx->nl_msg);
> +err_sock:
> +	nl_socket_free(ctx->nl_sock);
> +err_free:
> +	free(ctx);
> +	return NULL;
> +}
> +
> +static struct nl_ctx *nl_ctx_alloc(struct ovpn_ctx *ovpn, int cmd)
> +{
> +	return nl_ctx_alloc_flags(ovpn, cmd, 0);
> +}
> +
> +static void nl_ctx_free(struct nl_ctx *ctx)
> +{
> +	if (!ctx)
> +		return;
> +
> +	nl_socket_free(ctx->nl_sock);
> +	nlmsg_free(ctx->nl_msg);
> +	nl_cb_put(ctx->nl_cb);
> +	free(ctx);
> +}
> +
> +static int ovpn_nl_cb_error(struct sockaddr_nl (*nla)__always_unused,
> +			    struct nlmsgerr *err, void *arg)
> +{
> +	struct nlmsghdr *nlh = (struct nlmsghdr *)err - 1;
> +	struct nlattr *tb_msg[NLMSGERR_ATTR_MAX + 1];
> +	int len = nlh->nlmsg_len;
> +	struct nlattr *attrs;
> +	int *ret = arg;
> +	int ack_len = sizeof(*nlh) + sizeof(int) + sizeof(*nlh);
> +
> +	*ret = err->error;
> +
> +	if (!(nlh->nlmsg_flags & NLM_F_ACK_TLVS))
> +		return NL_STOP;
> +
> +	if (!(nlh->nlmsg_flags & NLM_F_CAPPED))
> +		ack_len += err->msg.nlmsg_len - sizeof(*nlh);
> +
> +	if (len <= ack_len)
> +		return NL_STOP;
> +
> +	attrs = (void *)((uint8_t *)nlh + ack_len);
> +	len -= ack_len;
> +
> +	nla_parse(tb_msg, NLMSGERR_ATTR_MAX, attrs, len, NULL);
> +	if (tb_msg[NLMSGERR_ATTR_MSG]) {
> +		len = strnlen((char *)nla_data(tb_msg[NLMSGERR_ATTR_MSG]),
> +			      nla_len(tb_msg[NLMSGERR_ATTR_MSG]));
> +		fprintf(stderr, "kernel error: %*s\n", len,
> +			(char *)nla_data(tb_msg[NLMSGERR_ATTR_MSG]));
> +	}
> +
> +	if (tb_msg[NLMSGERR_ATTR_MISS_NEST]) {
> +		fprintf(stderr, "missing required nesting type %u\n",
> +			nla_get_u32(tb_msg[NLMSGERR_ATTR_MISS_NEST]));
> +	}
> +
> +	if (tb_msg[NLMSGERR_ATTR_MISS_TYPE]) {
> +		fprintf(stderr, "missing required attribute type %u\n",
> +			nla_get_u32(tb_msg[NLMSGERR_ATTR_MISS_TYPE]));
> +	}
> +
> +	return NL_STOP;
> +}
> +
> +static int ovpn_nl_cb_finish(struct nl_msg (*msg)__always_unused,
> +			     void *arg)
> +{
> +	int *status = arg;
> +
> +	*status = 0;
> +	return NL_SKIP;
> +}
> +
> +static int ovpn_nl_cb_ack(struct nl_msg (*msg)__always_unused,
> +			  void *arg)
> +{
> +	int *status = arg;
> +
> +	*status = 0;
> +	return NL_STOP;
> +}
> +
> +static int ovpn_nl_msg_send(struct nl_ctx *ctx, ovpn_nl_cb cb)
> +{
> +	int status = 1;
> +
> +	nl_cb_err(ctx->nl_cb, NL_CB_CUSTOM, ovpn_nl_cb_error, &status);
> +	nl_cb_set(ctx->nl_cb, NL_CB_FINISH, NL_CB_CUSTOM, ovpn_nl_cb_finish,
> +		  &status);
> +	nl_cb_set(ctx->nl_cb, NL_CB_ACK, NL_CB_CUSTOM, ovpn_nl_cb_ack, &status);
> +
> +	if (cb)
> +		nl_cb_set(ctx->nl_cb, NL_CB_VALID, NL_CB_CUSTOM, cb, ctx);
> +
> +	nl_send_auto_complete(ctx->nl_sock, ctx->nl_msg);
> +
> +	while (status == 1)
> +		ovpn_nl_recvmsgs(ctx);
> +
> +	if (status < 0)
> +		fprintf(stderr, "failed to send netlink message: %s (%d)\n",
> +			strerror(-status), status);
> +
> +	return status;
> +}
> +
> +static int ovpn_parse_key(const char *file, struct ovpn_ctx *ctx)
> +{
> +	int idx_enc, idx_dec, ret = -1;
> +	unsigned char *ckey = NULL;
> +	__u8 *bkey = NULL;
> +	size_t olen = 0;
> +	long ckey_len;
> +	FILE *fp;
> +
> +	fp = fopen(file, "r");
> +	if (!fp) {
> +		fprintf(stderr, "cannot open: %s\n", file);
> +		return -1;
> +	}
> +
> +	/* get file size */
> +	fseek(fp, 0L, SEEK_END);
> +	ckey_len = ftell(fp);
> +	rewind(fp);
> +
> +	/* if the file is longer, let's just read a portion */
> +	if (ckey_len > 256)
> +		ckey_len = 256;
> +
> +	ckey = malloc(ckey_len);
> +	if (!ckey)
> +		goto err;
> +
> +	ret = fread(ckey, 1, ckey_len, fp);
> +	if (ret != ckey_len) {
> +		fprintf(stderr,
> +			"couldn't read enough data from key file: %dbytes read\n",
> +			ret);
> +		goto err;
> +	}
> +
> +	olen = 0;
> +	ret = mbedtls_base64_decode(NULL, 0, &olen, ckey, ckey_len);
> +	if (ret != MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL) {
> +		char buf[256];
> +
> +		mbedtls_strerror(ret, buf, sizeof(buf));
> +		fprintf(stderr, "unexpected base64 error1: %s (%d)\n", buf,
> +			ret);
> +
> +		goto err;
> +	}
> +
> +	bkey = malloc(olen);
> +	if (!bkey) {
> +		fprintf(stderr, "cannot allocate binary key buffer\n");
> +		goto err;
> +	}
> +
> +	ret = mbedtls_base64_decode(bkey, olen, &olen, ckey, ckey_len);
> +	if (ret) {
> +		char buf[256];
> +
> +		mbedtls_strerror(ret, buf, sizeof(buf));
> +		fprintf(stderr, "unexpected base64 error2: %s (%d)\n", buf,
> +			ret);
> +
> +		goto err;
> +	}
> +
> +	if (olen < 2 * KEY_LEN + NONCE_LEN) {
> +		fprintf(stderr,
> +			"not enough data in key file, found %zdB but needs %dB\n",
> +			olen, 2 * KEY_LEN + NONCE_LEN);
> +		goto err;
> +	}
> +
> +	switch (ctx->key_dir) {
> +	case KEY_DIR_IN:
> +		idx_enc = 0;
> +		idx_dec = 1;
> +		break;
> +	case KEY_DIR_OUT:
> +		idx_enc = 1;
> +		idx_dec = 0;
> +		break;
> +	default:
> +		goto err;
> +	}
> +
> +	memcpy(ctx->key_enc, bkey + KEY_LEN * idx_enc, KEY_LEN);
> +	memcpy(ctx->key_dec, bkey + KEY_LEN * idx_dec, KEY_LEN);
> +	memcpy(ctx->nonce, bkey + 2 * KEY_LEN, NONCE_LEN);
> +
> +	ret = 0;
> +
> +err:
> +	fclose(fp);
> +	free(bkey);
> +	free(ckey);
> +
> +	return ret;
> +}
> +
> +static int ovpn_parse_cipher(const char *cipher, struct ovpn_ctx *ctx)
> +{
> +	if (strcmp(cipher, "aes") == 0)
> +		ctx->cipher = OVPN_CIPHER_ALG_AES_GCM;
> +	else if (strcmp(cipher, "chachapoly") == 0)
> +		ctx->cipher = OVPN_CIPHER_ALG_CHACHA20_POLY1305;
> +	else if (strcmp(cipher, "none") == 0)
> +		ctx->cipher = OVPN_CIPHER_ALG_NONE;
> +	else
> +		return -ENOTSUP;
> +
> +	return 0;
> +}
> +
> +static int ovpn_parse_key_direction(const char *dir, struct ovpn_ctx *ctx)
> +{
> +	int in_dir;
> +
> +	in_dir = strtoll(dir, NULL, 10);
> +	switch (in_dir) {
> +	case KEY_DIR_IN:
> +	case KEY_DIR_OUT:
> +		ctx->key_dir = in_dir;
> +		break;
> +	default:
> +		fprintf(stderr,
> +			"invalid key direction provided. Can be 0 or 1 only\n");
> +		return -1;
> +	}
> +
> +	return 0;
> +}
> +
> +static int ovpn_socket(struct ovpn_ctx *ctx, sa_family_t family, int proto)
> +{
> +	struct sockaddr_storage local_sock = { 0 };
> +	struct sockaddr_in6 *in6;
> +	struct sockaddr_in *in;
> +	int ret, s, sock_type;
> +	size_t sock_len;
> +
> +	if (proto == IPPROTO_UDP)
> +		sock_type = SOCK_DGRAM;
> +	else if (proto == IPPROTO_TCP)
> +		sock_type = SOCK_STREAM;
> +	else
> +		return -EINVAL;
> +
> +	s = socket(family, sock_type, 0);
> +	if (s < 0) {
> +		perror("cannot create socket");
> +		return -1;
> +	}
> +
> +	switch (family) {
> +	case AF_INET:
> +		in = (struct sockaddr_in *)&local_sock;
> +		in->sin_family = family;
> +		in->sin_port = htons(ctx->lport);
> +		in->sin_addr.s_addr = htonl(INADDR_ANY);
> +		sock_len = sizeof(*in);
> +		break;
> +	case AF_INET6:
> +		in6 = (struct sockaddr_in6 *)&local_sock;
> +		in6->sin6_family = family;
> +		in6->sin6_port = htons(ctx->lport);
> +		in6->sin6_addr = in6addr_any;
> +		sock_len = sizeof(*in6);
> +		break;
> +	default:
> +		return -1;
> +	}
> +
> +	int opt = 1;
> +
> +	ret = setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
> +
> +	if (ret < 0) {
> +		perror("setsockopt for SO_REUSEADDR");
> +		return ret;
> +	}
> +
> +	ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &opt, sizeof(opt));
> +	if (ret < 0) {
> +		perror("setsockopt for SO_REUSEPORT");
> +		return ret;
> +	}
> +
> +	if (family == AF_INET6) {
> +		opt = 0;
> +		if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &opt,
> +			       sizeof(opt))) {
> +			perror("failed to set IPV6_V6ONLY");
> +			return -1;
> +		}
> +	}
> +
> +	ret = bind(s, (struct sockaddr *)&local_sock, sock_len);
> +	if (ret < 0) {
> +		perror("cannot bind socket");
> +		goto err_socket;
> +	}
> +
> +	ctx->socket = s;
> +	ctx->sa_family = family;
> +	return 0;
> +
> +err_socket:
> +	close(s);
> +	return -1;
> +}
> +
> +static int ovpn_udp_socket(struct ovpn_ctx *ctx, sa_family_t family)
> +{
> +	return ovpn_socket(ctx, family, IPPROTO_UDP);
> +}
> +
> +static int ovpn_listen(struct ovpn_ctx *ctx, sa_family_t family)
> +{
> +	int ret;
> +
> +	ret = ovpn_socket(ctx, family, IPPROTO_TCP);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = listen(ctx->socket, 10);
> +	if (ret < 0) {
> +		perror("listen");
> +		close(ctx->socket);
> +		return -1;
> +	}
> +
> +	return 0;
> +}
> +
> +static int ovpn_accept(struct ovpn_ctx *ctx)
> +{
> +	socklen_t socklen;
> +	int ret;
> +
> +	socklen = sizeof(ctx->remote);
> +	ret = accept(ctx->socket, (struct sockaddr *)&ctx->remote, &socklen);
> +	if (ret < 0) {
> +		perror("accept");
> +		goto err;
> +	}
> +
> +	fprintf(stderr, "Connection received!\n");
> +
> +	switch (socklen) {
> +	case sizeof(struct sockaddr_in):
> +	case sizeof(struct sockaddr_in6):
> +		break;
> +	default:
> +		fprintf(stderr, "error: expecting IPv4 or IPv6 connection\n");
> +		close(ret);
> +		ret = -EINVAL;
> +		goto err;
> +	}
> +
> +	return ret;
> +err:
> +	close(ctx->socket);
> +	return ret;
> +}
> +
> +static int ovpn_connect(struct ovpn_ctx *ovpn)
> +{
> +	socklen_t socklen;
> +	int s, ret;
> +
> +	s = socket(ovpn->remote.in4.sin_family, SOCK_STREAM, 0);
> +	if (s < 0) {
> +		perror("cannot create socket");
> +		return -1;
> +	}
> +
> +	switch (ovpn->remote.in4.sin_family) {
> +	case AF_INET:
> +		socklen = sizeof(struct sockaddr_in);
> +		break;
> +	case AF_INET6:
> +		socklen = sizeof(struct sockaddr_in6);
> +		break;
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +
> +	ret = connect(s, (struct sockaddr *)&ovpn->remote, socklen);
> +	if (ret < 0) {
> +		perror("connect");
> +		goto err;
> +	}
> +
> +	fprintf(stderr, "connected\n");
> +
> +	ovpn->socket = s;
> +
> +	return 0;
> +err:
> +	close(s);
> +	return ret;
> +}
> +
> +static int ovpn_new_peer(struct ovpn_ctx *ovpn, bool is_tcp)
> +{
> +	struct nlattr *attr;
> +	struct nl_ctx *ctx;
> +	int ret = -1;
> +
> +	ctx = nl_ctx_alloc(ovpn, OVPN_CMD_PEER_NEW);
> +	if (!ctx)
> +		return -ENOMEM;
> +
> +	attr = nla_nest_start(ctx->nl_msg, OVPN_A_PEER);
> +	NLA_PUT_U32(ctx->nl_msg, OVPN_A_PEER_ID, ovpn->peer_id);
> +	NLA_PUT_U32(ctx->nl_msg, OVPN_A_PEER_SOCKET, ovpn->socket);
> +
> +	if (!is_tcp) {
> +		switch (ovpn->remote.in4.sin_family) {
> +		case AF_INET:
> +			NLA_PUT_U32(ctx->nl_msg, OVPN_A_PEER_REMOTE_IPV4,
> +				    ovpn->remote.in4.sin_addr.s_addr);
> +			NLA_PUT_U16(ctx->nl_msg, OVPN_A_PEER_REMOTE_PORT,
> +				    ovpn->remote.in4.sin_port);
> +			break;
> +		case AF_INET6:
> +			NLA_PUT(ctx->nl_msg, OVPN_A_PEER_REMOTE_IPV6,
> +				sizeof(ovpn->remote.in6.sin6_addr),
> +				&ovpn->remote.in6.sin6_addr);
> +			NLA_PUT_U32(ctx->nl_msg,
> +				    OVPN_A_PEER_REMOTE_IPV6_SCOPE_ID,
> +				    ovpn->remote.in6.sin6_scope_id);
> +			NLA_PUT_U16(ctx->nl_msg, OVPN_A_PEER_REMOTE_PORT,
> +				    ovpn->remote.in6.sin6_port);
> +			break;
> +		default:
> +			fprintf(stderr,
> +				"Invalid family for remote socket address\n");
> +			goto nla_put_failure;
> +		}
> +	}
> +
> +	if (ovpn->peer_ip_set) {
> +		switch (ovpn->peer_ip.in4.sin_family) {
> +		case AF_INET:
> +			NLA_PUT_U32(ctx->nl_msg, OVPN_A_PEER_VPN_IPV4,
> +				    ovpn->peer_ip.in4.sin_addr.s_addr);
> +			break;
> +		case AF_INET6:
> +			NLA_PUT(ctx->nl_msg, OVPN_A_PEER_VPN_IPV6,
> +				sizeof(struct in6_addr),
> +				&ovpn->peer_ip.in6.sin6_addr);
> +			break;
> +		default:
> +			fprintf(stderr, "Invalid family for peer address\n");
> +			goto nla_put_failure;
> +		}
> +	}
> +
> +	nla_nest_end(ctx->nl_msg, attr);
> +
> +	ret = ovpn_nl_msg_send(ctx, NULL);
> +nla_put_failure:
> +	nl_ctx_free(ctx);
> +	return ret;
> +}
> +
> +static int ovpn_set_peer(struct ovpn_ctx *ovpn)
> +{
> +	struct nlattr *attr;
> +	struct nl_ctx *ctx;
> +	int ret = -1;
> +
> +	ctx = nl_ctx_alloc(ovpn, OVPN_CMD_PEER_SET);
> +	if (!ctx)
> +		return -ENOMEM;
> +
> +	attr = nla_nest_start(ctx->nl_msg, OVPN_A_PEER);
> +	NLA_PUT_U32(ctx->nl_msg, OVPN_A_PEER_ID, ovpn->peer_id);
> +	NLA_PUT_U32(ctx->nl_msg, OVPN_A_PEER_KEEPALIVE_INTERVAL,
> +		    ovpn->keepalive_interval);
> +	NLA_PUT_U32(ctx->nl_msg, OVPN_A_PEER_KEEPALIVE_TIMEOUT,
> +		    ovpn->keepalive_timeout);
> +	nla_nest_end(ctx->nl_msg, attr);
> +
> +	ret = ovpn_nl_msg_send(ctx, NULL);
> +nla_put_failure:
> +	nl_ctx_free(ctx);
> +	return ret;
> +}
> +
> +static int ovpn_del_peer(struct ovpn_ctx *ovpn)
> +{
> +	struct nlattr *attr;
> +	struct nl_ctx *ctx;
> +	int ret = -1;
> +
> +	ctx = nl_ctx_alloc(ovpn, OVPN_CMD_PEER_DEL);
> +	if (!ctx)
> +		return -ENOMEM;
> +
> +	attr = nla_nest_start(ctx->nl_msg, OVPN_A_PEER);
> +	NLA_PUT_U32(ctx->nl_msg, OVPN_A_PEER_ID, ovpn->peer_id);
> +	nla_nest_end(ctx->nl_msg, attr);
> +
> +	ret = ovpn_nl_msg_send(ctx, NULL);
> +nla_put_failure:
> +	nl_ctx_free(ctx);
> +	return ret;
> +}
> +
> +static int ovpn_handle_peer(struct nl_msg *msg, void (*arg)__always_unused)
> +{
> +	struct nlattr *pattrs[OVPN_A_PEER_MAX + 1];
> +	struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
> +	struct nlattr *attrs[OVPN_A_MAX + 1];
> +	__u16 rport = 0, lport = 0;
> +
> +	nla_parse(attrs, OVPN_A_MAX, genlmsg_attrdata(gnlh, 0),
> +		  genlmsg_attrlen(gnlh, 0), NULL);
> +
> +	if (!attrs[OVPN_A_PEER]) {
> +		fprintf(stderr, "no packet content in netlink message\n");
> +		return NL_SKIP;
> +	}
> +
> +	nla_parse(pattrs, OVPN_A_PEER_MAX, nla_data(attrs[OVPN_A_PEER]),
> +		  nla_len(attrs[OVPN_A_PEER]), NULL);
> +
> +	if (pattrs[OVPN_A_PEER_ID])
> +		fprintf(stderr, "* Peer %u\n",
> +			nla_get_u32(pattrs[OVPN_A_PEER_ID]));
> +
> +	if (pattrs[OVPN_A_PEER_VPN_IPV4]) {
> +		char buf[INET_ADDRSTRLEN];
> +
> +		inet_ntop(AF_INET, nla_data(pattrs[OVPN_A_PEER_VPN_IPV4]),
> +			  buf, sizeof(buf));
> +		fprintf(stderr, "\tVPN IPv4: %s\n", buf);
> +	}
> +
> +	if (pattrs[OVPN_A_PEER_VPN_IPV6]) {
> +		char buf[INET6_ADDRSTRLEN];
> +
> +		inet_ntop(AF_INET6, nla_data(pattrs[OVPN_A_PEER_VPN_IPV6]),
> +			  buf, sizeof(buf));
> +		fprintf(stderr, "\tVPN IPv6: %s\n", buf);
> +	}
> +
> +	if (pattrs[OVPN_A_PEER_LOCAL_PORT])
> +		lport = ntohs(nla_get_u16(pattrs[OVPN_A_PEER_LOCAL_PORT]));
> +
> +	if (pattrs[OVPN_A_PEER_REMOTE_PORT])
> +		rport = ntohs(nla_get_u16(pattrs[OVPN_A_PEER_REMOTE_PORT]));
> +
> +	if (pattrs[OVPN_A_PEER_REMOTE_IPV6]) {
> +		void *ip = pattrs[OVPN_A_PEER_REMOTE_IPV6];
> +		char buf[INET6_ADDRSTRLEN];
> +		int scope_id = -1;
> +
> +		if (pattrs[OVPN_A_PEER_REMOTE_IPV6_SCOPE_ID]) {
> +			void *p = pattrs[OVPN_A_PEER_REMOTE_IPV6_SCOPE_ID];
> +
> +			scope_id = nla_get_u32(p);
> +		}
> +
> +		inet_ntop(AF_INET6, nla_data(ip), buf, sizeof(buf));
> +		fprintf(stderr, "\tRemote: %s:%hu (scope-id: %u)\n", buf, rport,
> +			scope_id);
> +
> +		if (pattrs[OVPN_A_PEER_LOCAL_IPV6]) {
> +			void *ip = pattrs[OVPN_A_PEER_LOCAL_IPV6];
> +
> +			inet_ntop(AF_INET6, nla_data(ip), buf, sizeof(buf));
> +			fprintf(stderr, "\tLocal: %s:%hu\n", buf, lport);
> +		}
> +	}
> +
> +	if (pattrs[OVPN_A_PEER_REMOTE_IPV4]) {
> +		void *ip = pattrs[OVPN_A_PEER_REMOTE_IPV4];
> +		char buf[INET_ADDRSTRLEN];
> +
> +		inet_ntop(AF_INET, nla_data(ip), buf, sizeof(buf));
> +		fprintf(stderr, "\tRemote: %s:%hu\n", buf, rport);
> +
> +		if (pattrs[OVPN_A_PEER_LOCAL_IPV4]) {
> +			void *p = pattrs[OVPN_A_PEER_LOCAL_IPV4];
> +
> +			inet_ntop(AF_INET, nla_data(p), buf, sizeof(buf));
> +			fprintf(stderr, "\tLocal: %s:%hu\n", buf, lport);
> +		}
> +	}
> +
> +	if (pattrs[OVPN_A_PEER_KEEPALIVE_INTERVAL]) {
> +		void *p = pattrs[OVPN_A_PEER_KEEPALIVE_INTERVAL];
> +
> +		fprintf(stderr, "\tKeepalive interval: %u sec\n",
> +			nla_get_u32(p));
> +	}
> +
> +	if (pattrs[OVPN_A_PEER_KEEPALIVE_TIMEOUT])
> +		fprintf(stderr, "\tKeepalive timeout: %u sec\n",
> +			nla_get_u32(pattrs[OVPN_A_PEER_KEEPALIVE_TIMEOUT]));
> +
> +	if (pattrs[OVPN_A_PEER_VPN_RX_BYTES])
> +		fprintf(stderr, "\tVPN RX bytes: %" PRIu64 "\n",
> +			nla_get_uint(pattrs[OVPN_A_PEER_VPN_RX_BYTES]));
> +
> +	if (pattrs[OVPN_A_PEER_VPN_TX_BYTES])
> +		fprintf(stderr, "\tVPN TX bytes: %" PRIu64 "\n",
> +			nla_get_uint(pattrs[OVPN_A_PEER_VPN_TX_BYTES]));
> +
> +	if (pattrs[OVPN_A_PEER_VPN_RX_PACKETS])
> +		fprintf(stderr, "\tVPN RX packets: %" PRIu64 "\n",
> +			nla_get_uint(pattrs[OVPN_A_PEER_VPN_RX_PACKETS]));
> +
> +	if (pattrs[OVPN_A_PEER_VPN_TX_PACKETS])
> +		fprintf(stderr, "\tVPN TX packets: %" PRIu64 "\n",
> +			nla_get_uint(pattrs[OVPN_A_PEER_VPN_TX_PACKETS]));
> +
> +	if (pattrs[OVPN_A_PEER_LINK_RX_BYTES])
> +		fprintf(stderr, "\tLINK RX bytes: %" PRIu64 "\n",
> +			nla_get_uint(pattrs[OVPN_A_PEER_LINK_RX_BYTES]));
> +
> +	if (pattrs[OVPN_A_PEER_LINK_TX_BYTES])
> +		fprintf(stderr, "\tLINK TX bytes: %" PRIu64 "\n",
> +			nla_get_uint(pattrs[OVPN_A_PEER_LINK_TX_BYTES]));
> +
> +	if (pattrs[OVPN_A_PEER_LINK_RX_PACKETS])
> +		fprintf(stderr, "\tLINK RX packets: %" PRIu64 "\n",
> +			nla_get_uint(pattrs[OVPN_A_PEER_LINK_RX_PACKETS]));
> +
> +	if (pattrs[OVPN_A_PEER_LINK_TX_PACKETS])
> +		fprintf(stderr, "\tLINK TX packets: %" PRIu64 "\n",
> +			nla_get_uint(pattrs[OVPN_A_PEER_LINK_TX_PACKETS]));
> +
> +	return NL_SKIP;
> +}
> +
> +static int ovpn_get_peer(struct ovpn_ctx *ovpn)
> +{
> +	int flags = 0, ret = -1;
> +	struct nlattr *attr;
> +	struct nl_ctx *ctx;
> +
> +	if (ovpn->peer_id == PEER_ID_UNDEF)
> +		flags = NLM_F_DUMP;
> +
> +	ctx = nl_ctx_alloc_flags(ovpn, OVPN_CMD_PEER_GET, flags);
> +	if (!ctx)
> +		return -ENOMEM;
> +
> +	if (ovpn->peer_id != PEER_ID_UNDEF) {
> +		attr = nla_nest_start(ctx->nl_msg, OVPN_A_PEER);
> +		NLA_PUT_U32(ctx->nl_msg, OVPN_A_PEER_ID, ovpn->peer_id);
> +		nla_nest_end(ctx->nl_msg, attr);
> +	}
> +
> +	ret = ovpn_nl_msg_send(ctx, ovpn_handle_peer);
> +nla_put_failure:
> +	nl_ctx_free(ctx);
> +	return ret;
> +}
> +
> +static int ovpn_new_key(struct ovpn_ctx *ovpn)
> +{
> +	struct nlattr *keyconf, *key_dir;
> +	struct nl_ctx *ctx;
> +	int ret = -1;
> +
> +	ctx = nl_ctx_alloc(ovpn, OVPN_CMD_KEY_NEW);
> +	if (!ctx)
> +		return -ENOMEM;
> +
> +	keyconf = nla_nest_start(ctx->nl_msg, OVPN_A_KEYCONF);
> +	NLA_PUT_U32(ctx->nl_msg, OVPN_A_KEYCONF_PEER_ID, ovpn->peer_id);
> +	NLA_PUT_U32(ctx->nl_msg, OVPN_A_KEYCONF_SLOT, ovpn->key_slot);
> +	NLA_PUT_U32(ctx->nl_msg, OVPN_A_KEYCONF_KEY_ID, ovpn->key_id);
> +	NLA_PUT_U32(ctx->nl_msg, OVPN_A_KEYCONF_CIPHER_ALG, ovpn->cipher);
> +
> +	key_dir = nla_nest_start(ctx->nl_msg, OVPN_A_KEYCONF_ENCRYPT_DIR);
> +	NLA_PUT(ctx->nl_msg, OVPN_A_KEYDIR_CIPHER_KEY, KEY_LEN, ovpn->key_enc);
> +	NLA_PUT(ctx->nl_msg, OVPN_A_KEYDIR_NONCE_TAIL, NONCE_LEN, ovpn->nonce);
> +	nla_nest_end(ctx->nl_msg, key_dir);
> +
> +	key_dir = nla_nest_start(ctx->nl_msg, OVPN_A_KEYCONF_DECRYPT_DIR);
> +	NLA_PUT(ctx->nl_msg, OVPN_A_KEYDIR_CIPHER_KEY, KEY_LEN, ovpn->key_dec);
> +	NLA_PUT(ctx->nl_msg, OVPN_A_KEYDIR_NONCE_TAIL, NONCE_LEN, ovpn->nonce);
> +	nla_nest_end(ctx->nl_msg, key_dir);
> +
> +	nla_nest_end(ctx->nl_msg, keyconf);
> +
> +	ret = ovpn_nl_msg_send(ctx, NULL);
> +nla_put_failure:
> +	nl_ctx_free(ctx);
> +	return ret;
> +}
> +
> +static int ovpn_del_key(struct ovpn_ctx *ovpn)
> +{
> +	struct nlattr *keyconf;
> +	struct nl_ctx *ctx;
> +	int ret = -1;
> +
> +	ctx = nl_ctx_alloc(ovpn, OVPN_CMD_KEY_DEL);
> +	if (!ctx)
> +		return -ENOMEM;
> +
> +	keyconf = nla_nest_start(ctx->nl_msg, OVPN_A_KEYCONF);
> +	NLA_PUT_U32(ctx->nl_msg, OVPN_A_KEYCONF_PEER_ID, ovpn->peer_id);
> +	NLA_PUT_U32(ctx->nl_msg, OVPN_A_KEYCONF_SLOT, ovpn->key_slot);
> +	nla_nest_end(ctx->nl_msg, keyconf);
> +
> +	ret = ovpn_nl_msg_send(ctx, NULL);
> +nla_put_failure:
> +	nl_ctx_free(ctx);
> +	return ret;
> +}
> +
> +static int ovpn_handle_key(struct nl_msg *msg, void (*arg)__always_unused)
> +{
> +	struct nlattr *kattrs[OVPN_A_KEYCONF_MAX + 1];
> +	struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
> +	struct nlattr *attrs[OVPN_A_MAX + 1];
> +
> +	nla_parse(attrs, OVPN_A_MAX, genlmsg_attrdata(gnlh, 0),
> +		  genlmsg_attrlen(gnlh, 0), NULL);
> +
> +	if (!attrs[OVPN_A_KEYCONF]) {
> +		fprintf(stderr, "no packet content in netlink message\n");
> +		return NL_SKIP;
> +	}
> +
> +	nla_parse(kattrs, OVPN_A_KEYCONF_MAX, nla_data(attrs[OVPN_A_KEYCONF]),
> +		  nla_len(attrs[OVPN_A_KEYCONF]), NULL);
> +
> +	if (kattrs[OVPN_A_KEYCONF_PEER_ID])
> +		fprintf(stderr, "* Peer %u\n",
> +			nla_get_u32(kattrs[OVPN_A_KEYCONF_PEER_ID]));
> +	if (kattrs[OVPN_A_KEYCONF_SLOT]) {
> +		fprintf(stderr, "\t- Slot: ");
> +		switch (nla_get_u32(kattrs[OVPN_A_KEYCONF_SLOT])) {
> +		case OVPN_KEY_SLOT_PRIMARY:
> +			fprintf(stderr, "primary\n");
> +			break;
> +		case OVPN_KEY_SLOT_SECONDARY:
> +			fprintf(stderr, "secondary\n");
> +			break;
> +		default:
> +			fprintf(stderr, "invalid (%u)\n",
> +				nla_get_u32(kattrs[OVPN_A_KEYCONF_SLOT]));
> +			break;
> +		}
> +	}
> +	if (kattrs[OVPN_A_KEYCONF_KEY_ID])
> +		fprintf(stderr, "\t- Key ID: %u\n",
> +			nla_get_u32(kattrs[OVPN_A_KEYCONF_KEY_ID]));
> +	if (kattrs[OVPN_A_KEYCONF_CIPHER_ALG]) {
> +		fprintf(stderr, "\t- Cipher: ");
> +		switch (nla_get_u32(kattrs[OVPN_A_KEYCONF_CIPHER_ALG])) {
> +		case OVPN_CIPHER_ALG_NONE:
> +			fprintf(stderr, "none\n");
> +			break;
> +		case OVPN_CIPHER_ALG_AES_GCM:
> +			fprintf(stderr, "aes-gcm\n");
> +			break;
> +		case OVPN_CIPHER_ALG_CHACHA20_POLY1305:
> +			fprintf(stderr, "chacha20poly1305\n");
> +			break;
> +		default:
> +			fprintf(stderr, "invalid (%u)\n",
> +				nla_get_u32(kattrs[OVPN_A_KEYCONF_CIPHER_ALG]));
> +			break;
> +		}
> +	}
> +
> +	return NL_SKIP;
> +}
> +
> +static int ovpn_get_key(struct ovpn_ctx *ovpn)
> +{
> +	struct nlattr *keyconf;
> +	struct nl_ctx *ctx;
> +	int ret = -1;
> +
> +	ctx = nl_ctx_alloc(ovpn, OVPN_CMD_KEY_GET);
> +	if (!ctx)
> +		return -ENOMEM;
> +
> +	keyconf = nla_nest_start(ctx->nl_msg, OVPN_A_KEYCONF);
> +	NLA_PUT_U32(ctx->nl_msg, OVPN_A_KEYCONF_PEER_ID, ovpn->peer_id);
> +	NLA_PUT_U32(ctx->nl_msg, OVPN_A_KEYCONF_SLOT, ovpn->key_slot);
> +	nla_nest_end(ctx->nl_msg, keyconf);
> +
> +	ret = ovpn_nl_msg_send(ctx, ovpn_handle_key);
> +nla_put_failure:
> +	nl_ctx_free(ctx);
> +	return ret;
> +}
> +
> +static int ovpn_swap_keys(struct ovpn_ctx *ovpn)
> +{
> +	struct nl_ctx *ctx;
> +	struct nlattr *kc;
> +	int ret = -1;
> +
> +	ctx = nl_ctx_alloc(ovpn, OVPN_CMD_KEY_SWAP);
> +	if (!ctx)
> +		return -ENOMEM;
> +
> +	kc = nla_nest_start(ctx->nl_msg, OVPN_A_KEYCONF);
> +	NLA_PUT_U32(ctx->nl_msg, OVPN_A_KEYCONF_PEER_ID, ovpn->peer_id);
> +	nla_nest_end(ctx->nl_msg, kc);
> +
> +	ret = ovpn_nl_msg_send(ctx, NULL);
> +nla_put_failure:
> +	nl_ctx_free(ctx);
> +	return ret;
> +}
> +
> +/**
> + * Helper function used to easily add attributes to a rtnl message
> + */
> +static int ovpn_addattr(struct nlmsghdr *n, int maxlen, int type,
> +			const void *data, int alen)
> +{
> +	int len = RTA_LENGTH(alen);
> +	struct rtattr *rta;
> +
> +	if ((int)(NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len)) > maxlen)	{
> +		fprintf(stderr, "%s: rtnl: message exceeded bound of %d\n",
> +			__func__, maxlen);
> +		return -EMSGSIZE;
> +	}
> +
> +	rta = nlmsg_tail(n);
> +	rta->rta_type = type;
> +	rta->rta_len = len;
> +
> +	if (!data)
> +		memset(RTA_DATA(rta), 0, alen);
> +	else
> +		memcpy(RTA_DATA(rta), data, alen);
> +
> +	n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len);
> +
> +	return 0;
> +}
> +
> +static struct rtattr *ovpn_nest_start(struct nlmsghdr *msg, size_t max_size,
> +				      int attr)
> +{
> +	struct rtattr *nest = nlmsg_tail(msg);
> +
> +	if (ovpn_addattr(msg, max_size, attr, NULL, 0) < 0)
> +		return NULL;
> +
> +	return nest;
> +}
> +
> +static void ovpn_nest_end(struct nlmsghdr *msg, struct rtattr *nest)
> +{
> +	nest->rta_len = (uint8_t *)nlmsg_tail(msg) - (uint8_t *)nest;
> +}
> +
> +#define RT_SNDBUF_SIZE (1024 * 2)
> +#define RT_RCVBUF_SIZE (1024 * 4)
> +
> +/**
> + * Open RTNL socket
> + */
> +static int ovpn_rt_socket(void)
> +{
> +	int sndbuf = RT_SNDBUF_SIZE, rcvbuf = RT_RCVBUF_SIZE, fd;
> +
> +	fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
> +	if (fd < 0) {
> +		fprintf(stderr, "%s: cannot open netlink socket\n", __func__);
> +		return fd;
> +	}
> +
> +	if (setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &sndbuf,
> +		       sizeof(sndbuf)) < 0) {
> +		fprintf(stderr, "%s: SO_SNDBUF\n", __func__);
> +		close(fd);
> +		return -1;
> +	}
> +
> +	if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &rcvbuf,
> +		       sizeof(rcvbuf)) < 0) {
> +		fprintf(stderr, "%s: SO_RCVBUF\n", __func__);
> +		close(fd);
> +		return -1;
> +	}
> +
> +	return fd;
> +}
> +
> +/**
> + * Bind socket to Netlink subsystem
> + */
> +static int ovpn_rt_bind(int fd, uint32_t groups)
> +{
> +	struct sockaddr_nl local = { 0 };
> +	socklen_t addr_len;
> +
> +	local.nl_family = AF_NETLINK;
> +	local.nl_groups = groups;
> +
> +	if (bind(fd, (struct sockaddr *)&local, sizeof(local)) < 0) {
> +		fprintf(stderr, "%s: cannot bind netlink socket: %d\n",
> +			__func__, errno);
> +		return -errno;
> +	}
> +
> +	addr_len = sizeof(local);
> +	if (getsockname(fd, (struct sockaddr *)&local, &addr_len) < 0) {
> +		fprintf(stderr, "%s: cannot getsockname: %d\n", __func__,
> +			errno);
> +		return -errno;
> +	}
> +
> +	if (addr_len != sizeof(local)) {
> +		fprintf(stderr, "%s: wrong address length %d\n", __func__,
> +			addr_len);
> +		return -EINVAL;
> +	}
> +
> +	if (local.nl_family != AF_NETLINK) {
> +		fprintf(stderr, "%s: wrong address family %d\n", __func__,
> +			local.nl_family);
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +typedef int (*ovpn_parse_reply_cb)(struct nlmsghdr *msg, void *arg);
> +
> +/**
> + * Send Netlink message and run callback on reply (if specified)
> + */
> +static int ovpn_rt_send(struct nlmsghdr *payload, pid_t peer,
> +			unsigned int groups, ovpn_parse_reply_cb cb,
> +			void *arg_cb)
> +{
> +	int len, rem_len, fd, ret, rcv_len;
> +	struct sockaddr_nl nladdr = { 0 };
> +	struct nlmsgerr *err;
> +	struct nlmsghdr *h;
> +	char buf[1024 * 16];
> +	struct iovec iov = {
> +		.iov_base = payload,
> +		.iov_len = payload->nlmsg_len,
> +	};
> +	struct msghdr nlmsg = {
> +		.msg_name = &nladdr,
> +		.msg_namelen = sizeof(nladdr),
> +		.msg_iov = &iov,
> +		.msg_iovlen = 1,
> +	};
> +
> +	nladdr.nl_family = AF_NETLINK;
> +	nladdr.nl_pid = peer;
> +	nladdr.nl_groups = groups;
> +
> +	payload->nlmsg_seq = time(NULL);
> +
> +	/* no need to send reply */
> +	if (!cb)
> +		payload->nlmsg_flags |= NLM_F_ACK;
> +
> +	fd = ovpn_rt_socket();
> +	if (fd < 0) {
> +		fprintf(stderr, "%s: can't open rtnl socket\n", __func__);
> +		return -errno;
> +	}
> +
> +	ret = ovpn_rt_bind(fd, 0);
> +	if (ret < 0) {
> +		fprintf(stderr, "%s: can't bind rtnl socket\n", __func__);
> +		ret = -errno;
> +		goto out;
> +	}
> +
> +	ret = sendmsg(fd, &nlmsg, 0);
> +	if (ret < 0) {
> +		fprintf(stderr, "%s: rtnl: error on sendmsg()\n", __func__);
> +		ret = -errno;
> +		goto out;
> +	}
> +
> +	/* prepare buffer to store RTNL replies */
> +	memset(buf, 0, sizeof(buf));
> +	iov.iov_base = buf;
> +
> +	while (1) {
> +		/*
> +		 * iov_len is modified by recvmsg(), therefore has to be initialized before
> +		 * using it again
> +		 */
> +		iov.iov_len = sizeof(buf);
> +		rcv_len = recvmsg(fd, &nlmsg, 0);
> +		if (rcv_len < 0) {
> +			if (errno == EINTR || errno == EAGAIN) {
> +				fprintf(stderr, "%s: interrupted call\n",
> +					__func__);
> +				continue;
> +			}
> +			fprintf(stderr, "%s: rtnl: error on recvmsg()\n",
> +				__func__);
> +			ret = -errno;
> +			goto out;
> +		}
> +
> +		if (rcv_len == 0) {
> +			fprintf(stderr,
> +				"%s: rtnl: socket reached unexpected EOF\n",
> +				__func__);
> +			ret = -EIO;
> +			goto out;
> +		}
> +
> +		if (nlmsg.msg_namelen != sizeof(nladdr)) {
> +			fprintf(stderr,
> +				"%s: sender address length: %u (expected %zu)\n",
> +				__func__, nlmsg.msg_namelen, sizeof(nladdr));
> +			ret = -EIO;
> +			goto out;
> +		}
> +
> +		h = (struct nlmsghdr *)buf;
> +		while (rcv_len >= (int)sizeof(*h)) {
> +			len = h->nlmsg_len;
> +			rem_len = len - sizeof(*h);
> +
> +			if (rem_len < 0 || len > rcv_len) {
> +				if (nlmsg.msg_flags & MSG_TRUNC) {
> +					fprintf(stderr, "%s: truncated message\n",
> +						__func__);
> +					ret = -EIO;
> +					goto out;
> +				}
> +				fprintf(stderr, "%s: malformed message: len=%d\n",
> +					__func__, len);
> +				ret = -EIO;
> +				goto out;
> +			}
> +
> +			if (h->nlmsg_type == NLMSG_DONE) {
> +				ret = 0;
> +				goto out;
> +			}
> +
> +			if (h->nlmsg_type == NLMSG_ERROR) {
> +				err = (struct nlmsgerr *)NLMSG_DATA(h);
> +				if (rem_len < (int)sizeof(struct nlmsgerr)) {
> +					fprintf(stderr, "%s: ERROR truncated\n",
> +						__func__);
> +					ret = -EIO;
> +					goto out;
> +				}
> +
> +				if (err->error) {
> +					fprintf(stderr, "%s: (%d) %s\n",
> +						__func__, err->error,
> +						strerror(-err->error));
> +					ret = err->error;
> +					goto out;
> +				}
> +
> +				ret = 0;
> +				if (cb)	{
> +					int r = cb(h, arg_cb);
> +
> +					if (r <= 0)
> +						ret = r;
> +				}
> +				goto out;
> +			}
> +
> +			if (cb) {
> +				int r = cb(h, arg_cb);
> +
> +				if (r <= 0) {
> +					ret = r;
> +					goto out;
> +				}
> +			} else {
> +				fprintf(stderr, "%s: RTNL: unexpected reply\n",
> +					__func__);
> +			}
> +
> +			rcv_len -= NLMSG_ALIGN(len);
> +			h = (struct nlmsghdr *)((uint8_t *)h +
> +						NLMSG_ALIGN(len));
> +		}
> +
> +		if (nlmsg.msg_flags & MSG_TRUNC) {
> +			fprintf(stderr, "%s: message truncated\n", __func__);
> +			continue;
> +		}
> +
> +		if (rcv_len) {
> +			fprintf(stderr, "%s: rtnl: %d not parsed bytes\n",
> +				__func__, rcv_len);
> +			ret = -1;
> +			goto out;
> +		}
> +	}
> +out:
> +	close(fd);
> +
> +	return ret;
> +}
> +
> +struct ovpn_link_req {
> +	struct nlmsghdr n;
> +	struct ifinfomsg i;
> +	char buf[256];
> +};
> +
> +static int ovpn_new_iface(struct ovpn_ctx *ovpn)
> +{
> +	struct rtattr *linkinfo, *data;
> +	struct ovpn_link_req req = { 0 };
> +	int ret = -1;
> +
> +	fprintf(stdout, "Creating interface %s with mode %u\n", ovpn->ifname,
> +		ovpn->mode);
> +
> +	req.n.nlmsg_len = NLMSG_LENGTH(sizeof(req.i));
> +	req.n.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_EXCL;
> +	req.n.nlmsg_type = RTM_NEWLINK;
> +
> +	if (ovpn_addattr(&req.n, sizeof(req), IFLA_IFNAME, ovpn->ifname,
> +			 strlen(ovpn->ifname) + 1) < 0)
> +		goto err;
> +
> +	linkinfo = ovpn_nest_start(&req.n, sizeof(req), IFLA_LINKINFO);
> +	if (!linkinfo)
> +		goto err;
> +
> +	if (ovpn_addattr(&req.n, sizeof(req), IFLA_INFO_KIND, OVPN_FAMILY_NAME,
> +			 strlen(OVPN_FAMILY_NAME) + 1) < 0)
> +		goto err;
> +
> +	if (ovpn->mode_set) {
> +		data = ovpn_nest_start(&req.n, sizeof(req), IFLA_INFO_DATA);
> +		if (!data)
> +			goto err;
> +
> +		if (ovpn_addattr(&req.n, sizeof(req), IFLA_OVPN_MODE,
> +				 &ovpn->mode, sizeof(uint8_t)) < 0)
> +			goto err;
> +
> +		ovpn_nest_end(&req.n, data);
> +	}
> +
> +	ovpn_nest_end(&req.n, linkinfo);
> +
> +	req.i.ifi_family = AF_PACKET;
> +
> +	ret = ovpn_rt_send(&req.n, 0, 0, NULL, NULL);
> +err:
> +	return ret;
> +}
> +
> +static int ovpn_del_iface(struct ovpn_ctx *ovpn)
> +{
> +	struct ovpn_link_req req = { 0 };
> +
> +	fprintf(stdout, "Deleting interface %s ifindex %u\n", ovpn->ifname,
> +		ovpn->ifindex);
> +
> +	req.n.nlmsg_len = NLMSG_LENGTH(sizeof(req.i));
> +	req.n.nlmsg_flags = NLM_F_REQUEST;
> +	req.n.nlmsg_type = RTM_DELLINK;
> +
> +	req.i.ifi_family = AF_PACKET;
> +	req.i.ifi_index = ovpn->ifindex;
> +
> +	return ovpn_rt_send(&req.n, 0, 0, NULL, NULL);
> +}
> +
> +static int nl_seq_check(struct nl_msg (*msg)__always_unused,
> +			void (*arg)__always_unused)
> +{
> +	return NL_OK;
> +}
> +
> +struct mcast_handler_args {
> +	const char *group;
> +	int id;
> +};
> +
> +static int mcast_family_handler(struct nl_msg *msg, void *arg)
> +{
> +	struct mcast_handler_args *grp = arg;
> +	struct nlattr *tb[CTRL_ATTR_MAX + 1];
> +	struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
> +	struct nlattr *mcgrp;
> +	int rem_mcgrp;
> +
> +	nla_parse(tb, CTRL_ATTR_MAX, genlmsg_attrdata(gnlh, 0),
> +		  genlmsg_attrlen(gnlh, 0), NULL);
> +
> +	if (!tb[CTRL_ATTR_MCAST_GROUPS])
> +		return NL_SKIP;
> +
> +	nla_for_each_nested(mcgrp, tb[CTRL_ATTR_MCAST_GROUPS], rem_mcgrp) {
> +		struct nlattr *tb_mcgrp[CTRL_ATTR_MCAST_GRP_MAX + 1];
> +
> +		nla_parse(tb_mcgrp, CTRL_ATTR_MCAST_GRP_MAX,
> +			  nla_data(mcgrp), nla_len(mcgrp), NULL);
> +
> +		if (!tb_mcgrp[CTRL_ATTR_MCAST_GRP_NAME] ||
> +		    !tb_mcgrp[CTRL_ATTR_MCAST_GRP_ID])
> +			continue;
> +		if (strncmp(nla_data(tb_mcgrp[CTRL_ATTR_MCAST_GRP_NAME]),
> +			    grp->group, nla_len(tb_mcgrp[CTRL_ATTR_MCAST_GRP_NAME])))
> +			continue;
> +		grp->id = nla_get_u32(tb_mcgrp[CTRL_ATTR_MCAST_GRP_ID]);
> +		break;
> +	}
> +
> +	return NL_SKIP;
> +}
> +
> +static int mcast_error_handler(struct sockaddr_nl (*nla)__always_unused,
> +			       struct nlmsgerr *err, void *arg)
> +{
> +	int *ret = arg;
> +
> +	*ret = err->error;
> +	return NL_STOP;
> +}
> +
> +static int mcast_ack_handler(struct nl_msg (*msg)__always_unused, void *arg)
> +{
> +	int *ret = arg;
> +
> +	*ret = 0;
> +	return NL_STOP;
> +}
> +
> +static int ovpn_handle_msg(struct nl_msg *msg, void *arg)
> +{
> +	struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
> +	struct nlattr *attrs[OVPN_A_MAX + 1];
> +	struct nlmsghdr *nlh = nlmsg_hdr(msg);
> +	//enum ovpn_del_peer_reason reason;
> +	char ifname[IF_NAMESIZE];
> +	int *ret = arg;
> +	__u32 ifindex;
> +
> +	fprintf(stderr, "received message from ovpn-dco\n");
> +
> +	*ret = -1;
> +
> +	if (!genlmsg_valid_hdr(nlh, 0)) {
> +		fprintf(stderr, "invalid header\n");
> +		return NL_STOP;
> +	}
> +
> +	if (nla_parse(attrs, OVPN_A_MAX, genlmsg_attrdata(gnlh, 0),
> +		      genlmsg_attrlen(gnlh, 0), NULL)) {
> +		fprintf(stderr, "received bogus data from ovpn-dco\n");
> +		return NL_STOP;
> +	}
> +
> +	if (!attrs[OVPN_A_IFINDEX]) {
> +		fprintf(stderr, "no ifindex in this message\n");
> +		return NL_STOP;
> +	}
> +
> +	ifindex = nla_get_u32(attrs[OVPN_A_IFINDEX]);
> +	if (!if_indextoname(ifindex, ifname)) {
> +		fprintf(stderr, "cannot resolve ifname for ifindex: %u\n",
> +			ifindex);
> +		return NL_STOP;
> +	}
> +
> +	switch (gnlh->cmd) {
> +	case OVPN_CMD_PEER_DEL_NTF:
> +		/*if (!attrs[OVPN_A_DEL_PEER_REASON]) {
> +		 *	fprintf(stderr, "no reason in DEL_PEER message\n");
> +		 *	return NL_STOP;
> +		 *}
> +		 *
> +		 *reason = nla_get_u8(attrs[OVPN_A_DEL_PEER_REASON]);
> +		 *fprintf(stderr,
> +		 *	"received CMD_DEL_PEER, ifname: %s reason: %d\n",
> +		 *	ifname, reason);
> +		 */
> +		fprintf(stdout, "received CMD_PEER_DEL_NTF\n");
> +		break;
> +	case OVPN_CMD_KEY_SWAP_NTF:
> +		fprintf(stdout, "received CMD_KEY_SWAP_NTF\n");
> +		break;
> +	default:
> +		fprintf(stderr, "received unknown command: %d\n", gnlh->cmd);
> +		return NL_STOP;
> +	}
> +
> +	*ret = 0;
> +	return NL_OK;
> +}
> +
> +static int ovpn_get_mcast_id(struct nl_sock *sock, const char *family,
> +			     const char *group)
> +{
> +	struct nl_msg *msg;
> +	struct nl_cb *cb;
> +	int ret, ctrlid;
> +	struct mcast_handler_args grp = {
> +		.group = group,
> +		.id = -ENOENT,
> +	};
> +
> +	msg = nlmsg_alloc();
> +	if (!msg)
> +		return -ENOMEM;
> +
> +	cb = nl_cb_alloc(NL_CB_DEFAULT);
> +	if (!cb) {
> +		ret = -ENOMEM;
> +		goto out_fail_cb;
> +	}
> +
> +	ctrlid = genl_ctrl_resolve(sock, "nlctrl");
> +
> +	genlmsg_put(msg, 0, 0, ctrlid, 0, 0, CTRL_CMD_GETFAMILY, 0);
> +
> +	ret = -ENOBUFS;
> +	NLA_PUT_STRING(msg, CTRL_ATTR_FAMILY_NAME, family);
> +
> +	ret = nl_send_auto_complete(sock, msg);
> +	if (ret < 0)
> +		goto nla_put_failure;
> +
> +	ret = 1;
> +
> +	nl_cb_err(cb, NL_CB_CUSTOM, mcast_error_handler, &ret);
> +	nl_cb_set(cb, NL_CB_ACK, NL_CB_CUSTOM, mcast_ack_handler, &ret);
> +	nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, mcast_family_handler, &grp);
> +
> +	while (ret > 0)
> +		nl_recvmsgs(sock, cb);
> +
> +	if (ret == 0)
> +		ret = grp.id;
> + nla_put_failure:
> +	nl_cb_put(cb);
> + out_fail_cb:
> +	nlmsg_free(msg);
> +	return ret;
> +}
> +
> +static int ovpn_listen_mcast(void)
> +{
> +	struct nl_sock *sock;
> +	struct nl_cb *cb;
> +	int mcid, ret;
> +
> +	sock = nl_socket_alloc();
> +	if (!sock) {
> +		fprintf(stderr, "cannot allocate netlink socket\n");
> +		goto err_free;
> +	}
> +
> +	nl_socket_set_buffer_size(sock, 8192, 8192);
> +
> +	ret = genl_connect(sock);
> +	if (ret < 0) {
> +		fprintf(stderr, "cannot connect to generic netlink: %s\n",
> +			nl_geterror(ret));
> +		goto err_free;
> +	}
> +
> +	mcid = ovpn_get_mcast_id(sock, OVPN_FAMILY_NAME, OVPN_MCGRP_PEERS);
> +	if (mcid < 0) {
> +		fprintf(stderr, "cannot get mcast group: %s\n",
> +			nl_geterror(mcid));
> +		goto err_free;
> +	}
> +
> +	ret = nl_socket_add_membership(sock, mcid);
> +	if (ret) {
> +		fprintf(stderr, "failed to join mcast group: %d\n", ret);
> +		goto err_free;
> +	}
> +
> +	ret = 1;
> +	cb = nl_cb_alloc(NL_CB_DEFAULT);
> +	nl_cb_set(cb, NL_CB_SEQ_CHECK, NL_CB_CUSTOM, nl_seq_check, NULL);
> +	nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, ovpn_handle_msg, &ret);
> +	nl_cb_err(cb, NL_CB_CUSTOM, ovpn_nl_cb_error, &ret);
> +
> +	while (ret == 1) {
> +		int err = nl_recvmsgs(sock, cb);
> +
> +		if (err < 0) {
> +			fprintf(stderr,
> +				"cannot receive netlink message: (%d) %s\n",
> +				err, nl_geterror(-err));
> +			ret = -1;
> +			break;
> +		}
> +	}
> +
> +	nl_cb_put(cb);
> +err_free:
> +	nl_socket_free(sock);
> +	return ret;
> +}
> +
> +static void usage(const char *cmd)
> +{
> +	fprintf(stderr,
> +		"Usage %s <command> <iface> [arguments..]\n",
> +		cmd);
> +	fprintf(stderr, "where <command> can be one of the following\n\n");
> +
> +	fprintf(stderr, "* new_iface <iface> [mode]: create new ovpn interface\n");
> +	fprintf(stderr, "\tiface: ovpn interface name\n");
> +	fprintf(stderr, "\tmode:\n");
> +	fprintf(stderr, "\t\t- P2P for peer-to-peer mode (i.e. client)\n");
> +	fprintf(stderr, "\t\t- MP for multi-peer mode (i.e. server)\n");
> +
> +	fprintf(stderr, "* del_iface <iface>: delete ovpn interface\n");
> +	fprintf(stderr, "\tiface: ovpn interface name\n");
> +
> +	fprintf(stderr,
> +		"* listen <iface> <lport> <peers_file> [ipv6]: listen for incoming peer TCP connections\n");
> +	fprintf(stderr, "\tiface: ovpn interface name\n");
> +	fprintf(stderr, "\tlport: TCP port to listen to\n");
> +	fprintf(stderr,
> +		"\tpeers_file: file containing one peer per line: Line format:\n");
> +	fprintf(stderr, "\t\t<peer_id> <vpnaddr>\n");
> +	fprintf(stderr,
> +		"\tipv6: whether the socket should listen to the IPv6 wildcard address\n");
> +
> +	fprintf(stderr,
> +		"* connect <iface> <peer_id> <raddr> <rport> [key_file]: start connecting peer of TCP-based VPN session\n");
> +	fprintf(stderr, "\tiface: ovpn interface name\n");
> +	fprintf(stderr, "\tpeer_id: peer ID of the connecting peer\n");
> +	fprintf(stderr, "\traddr: peer IP address to connect to\n");
> +	fprintf(stderr, "\trport: peer TCP port to connect to\n");
> +	fprintf(stderr,
> +		"\tkey_file: file containing the symmetric key for encryption\n");
> +
> +	fprintf(stderr,
> +		"* new_peer <iface> <peer_id> <lport> <raddr> <rport> [vpnaddr]: add new peer\n");
> +	fprintf(stderr, "\tiface: ovpn interface name\n");
> +	fprintf(stderr, "\tlport: local UDP port to bind to\n");
> +	fprintf(stderr,
> +		"\tpeer_id: peer ID to be used in data packets to/from this peer\n");
> +	fprintf(stderr, "\traddr: peer IP address\n");
> +	fprintf(stderr, "\trport: peer UDP port\n");
> +	fprintf(stderr, "\tvpnaddr: peer VPN IP\n");
> +
> +	fprintf(stderr,
> +		"* new_multi_peer <iface> <lport> <peers_file>: add multiple peers as listed in the file\n");
> +	fprintf(stderr, "\tiface: ovpn interface name\n");
> +	fprintf(stderr, "\tlport: local UDP port to bind to\n");
> +	fprintf(stderr,
> +		"\tpeers_file: text file containing one peer per line. Line format:\n");
> +	fprintf(stderr, "\t\t<peer_id> <raddr> <rport> <vpnaddr>\n");
> +
> +	fprintf(stderr,
> +		"* set_peer <iface> <peer_id> <keepalive_interval> <keepalive_timeout>: set peer attributes\n");
> +	fprintf(stderr, "\tiface: ovpn interface name\n");
> +	fprintf(stderr, "\tpeer_id: peer ID of the peer to modify\n");
> +	fprintf(stderr,
> +		"\tkeepalive_interval: interval for sending ping messages\n");
> +	fprintf(stderr,
> +		"\tkeepalive_timeout: time after which a peer is timed out\n");
> +
> +	fprintf(stderr, "* del_peer <iface> <peer_id>: delete peer\n");
> +	fprintf(stderr, "\tiface: ovpn interface name\n");
> +	fprintf(stderr, "\tpeer_id: peer ID of the peer to delete\n");
> +
> +	fprintf(stderr, "* get_peer <iface> [peer_id]: retrieve peer(s) status\n");
> +	fprintf(stderr, "\tiface: ovpn interface name\n");
> +	fprintf(stderr,
> +		"\tpeer_id: peer ID of the peer to query. All peers are returned if omitted\n");
> +
> +	fprintf(stderr,
> +		"* new_key <iface> <peer_id> <slot> <key_id> <cipher> <key_dir> <key_file>: set data channel key\n");
> +	fprintf(stderr, "\tiface: ovpn interface name\n");
> +	fprintf(stderr,
> +		"\tpeer_id: peer ID of the peer to configure the key for\n");
> +	fprintf(stderr, "\tslot: either 1 (primary) or 2 (secondary)\n");
> +	fprintf(stderr, "\tkey_id: an ID from 0 to 7\n");
> +	fprintf(stderr,
> +		"\tcipher: cipher to use, supported: aes (AES-GCM), chachapoly (CHACHA20POLY1305)\n");
> +	fprintf(stderr,
> +		"\tkey_dir: key direction, must 0 on one host and 1 on the other\n");
> +	fprintf(stderr, "\tkey_file: file containing the pre-shared key\n");
> +
> +	fprintf(stderr,
> +		"* del_key <iface> <peer_id> [slot]: erase existing data channel key\n");
> +	fprintf(stderr, "\tiface: ovpn interface name\n");
> +	fprintf(stderr, "\tpeer_id: peer ID of the peer to modify\n");
> +	fprintf(stderr, "\tslot: slot to erase. PRIMARY if omitted\n");
> +
> +	fprintf(stderr,
> +		"* get_key <iface> <peer_id> <slot>: retrieve non sensible key data\n");
> +	fprintf(stderr, "\tiface: ovpn interface name\n");
> +	fprintf(stderr, "\tpeer_id: peer ID of the peer to query\n");
> +	fprintf(stderr, "\tslot: either 1 (primary) or 2 (secondary)\n");
> +
> +	fprintf(stderr,
> +		"* swap_keys <iface> <peer_id>: swap content of primary and secondary key slots\n");
> +	fprintf(stderr, "\tiface: ovpn interface name\n");
> +	fprintf(stderr, "\tpeer_id: peer ID of the peer to modify\n");
> +
> +	fprintf(stderr,
> +		"* listen_mcast: listen to ovpn netlink multicast messages\n");
> +}

If this test is run from "make kselftest" as default run does this usage
output show up in the report?

> +
> +static int ovpn_parse_remote(struct ovpn_ctx *ovpn, const char *host,
> +			     const char *service, const char *vpnip)
> +{
> +	int ret;
> +	struct addrinfo *result;
> +	struct addrinfo hints = {
> +		.ai_family = ovpn->sa_family,
> +		.ai_socktype = SOCK_DGRAM,
> +		.ai_protocol = IPPROTO_UDP
> +	};
> +
> +	if (host) {
> +		ret = getaddrinfo(host, service, &hints, &result);
> +		if (ret == EAI_NONAME || ret == EAI_FAIL)
> +			return -1;
> +
> +		if (!(result->ai_family == AF_INET &&
> +		      result->ai_addrlen == sizeof(struct sockaddr_in)) &&
> +		    !(result->ai_family == AF_INET6 &&
> +		      result->ai_addrlen == sizeof(struct sockaddr_in6))) {
> +			ret = -EINVAL;
> +			goto out;
> +		}
> +
> +		memcpy(&ovpn->remote, result->ai_addr, result->ai_addrlen);
> +	}
> +
> +	if (vpnip) {
> +		ret = getaddrinfo(vpnip, NULL, &hints, &result);
> +		if (ret == EAI_NONAME || ret == EAI_FAIL)
> +			return -1;
> +
> +		if (!(result->ai_family == AF_INET &&
> +		      result->ai_addrlen == sizeof(struct sockaddr_in)) &&
> +		    !(result->ai_family == AF_INET6 &&
> +		      result->ai_addrlen == sizeof(struct sockaddr_in6))) {
> +			ret = -EINVAL;
> +			goto out;
> +		}
> +
> +		memcpy(&ovpn->peer_ip, result->ai_addr, result->ai_addrlen);
> +		ovpn->sa_family = result->ai_family;
> +
> +		ovpn->peer_ip_set = true;
> +	}
> +
> +	ret = 0;
> +out:
> +	freeaddrinfo(result);
> +	return ret;
> +}
> +
> +static int ovpn_parse_new_peer(struct ovpn_ctx *ovpn, const char *peer_id,
> +			       const char *raddr, const char *rport,
> +			       const char *vpnip)
> +{
> +	ovpn->peer_id = strtoul(peer_id, NULL, 10);
> +	if (errno == ERANGE || ovpn->peer_id > PEER_ID_UNDEF) {
> +		fprintf(stderr, "peer ID value out of range\n");
> +		return -1;
> +	}
> +
> +	return ovpn_parse_remote(ovpn, raddr, rport, vpnip);
> +}
> +
> +static int ovpn_parse_key_slot(const char *arg, struct ovpn_ctx *ovpn)
> +{
> +	int slot = strtoul(arg, NULL, 10);
> +
> +	if (errno == ERANGE || slot < 1 || slot > 2) {
> +		fprintf(stderr, "key slot out of range\n");
> +		return -1;
> +	}
> +
> +	switch (slot) {
> +	case 1:
> +		ovpn->key_slot = OVPN_KEY_SLOT_PRIMARY;
> +		break;
> +	case 2:
> +		ovpn->key_slot = OVPN_KEY_SLOT_SECONDARY;
> +		break;
> +	}
> +
> +	return 0;
> +}
> +
> +static int ovpn_send_tcp_data(int socket)
> +{
> +	uint16_t len = htons(1000);
> +	uint8_t buf[1002];
> +	int ret;
> +
> +	memcpy(buf, &len, sizeof(len));
> +	memset(buf + sizeof(len), 0x86, sizeof(buf) - sizeof(len));
> +
> +	ret = send(socket, buf, sizeof(buf), 0);
> +
> +	fprintf(stdout, "Sent %u bytes over TCP socket\n", ret);
> +
> +	return ret > 0 ? 0 : ret;
> +}
> +
> +static int ovpn_recv_tcp_data(int socket)
> +{
> +	uint8_t buf[1002];
> +	uint16_t len;
> +	int ret;
> +
> +	ret = recv(socket, buf, sizeof(buf), 0);
> +
> +	if (ret < 2) {
> +		fprintf(stderr, ">>>> Error while reading TCP data: %d\n", ret);
> +		return ret;
> +	}
> +
> +	memcpy(&len, buf, sizeof(len));
> +	len = ntohs(len);
> +
> +	fprintf(stdout, ">>>> Received %u bytes over TCP socket, header: %u\n",
> +		ret, len);
> +
> +/*	int i;
> + *	for (i = 2; i < ret; i++) {
> + *		fprintf(stdout, "0x%.2x ", buf[i]);
> + *		if (i && !((i - 2) % 16))
> + *			fprintf(stdout, "\n");
> + *	}
> + *	fprintf(stdout, "\n");
> + */
> +	return 0;
> +}
> +
> +static enum ovpn_cmd ovpn_parse_cmd(const char *cmd)
> +{
> +	if (!strcmp(cmd, "new_iface"))
> +		return CMD_NEW_IFACE;
> +
> +	if (!strcmp(cmd, "del_iface"))
> +		return CMD_DEL_IFACE;
> +
> +	if (!strcmp(cmd, "listen"))
> +		return CMD_LISTEN;
> +
> +	if (!strcmp(cmd, "connect"))
> +		return CMD_CONNECT;
> +
> +	if (!strcmp(cmd, "new_peer"))
> +		return CMD_NEW_PEER;
> +
> +	if (!strcmp(cmd, "new_multi_peer"))
> +		return CMD_NEW_MULTI_PEER;
> +
> +	if (!strcmp(cmd, "set_peer"))
> +		return CMD_SET_PEER;
> +
> +	if (!strcmp(cmd, "del_peer"))
> +		return CMD_DEL_PEER;
> +
> +	if (!strcmp(cmd, "get_peer"))
> +		return CMD_GET_PEER;
> +
> +	if (!strcmp(cmd, "new_key"))
> +		return CMD_NEW_KEY;
> +
> +	if (!strcmp(cmd, "del_key"))
> +		return CMD_DEL_KEY;
> +
> +	if (!strcmp(cmd, "get_key"))
> +		return CMD_GET_KEY;
> +
> +	if (!strcmp(cmd, "swap_keys"))
> +		return CMD_SWAP_KEYS;
> +
> +	if (!strcmp(cmd, "listen_mcast"))
> +		return CMD_LISTEN_MCAST;
> +
> +	return CMD_INVALID;
> +}
> +
> +static int ovpn_run_cmd(struct ovpn_ctx *ovpn)
> +{
> +	char peer_id[10], vpnip[INET6_ADDRSTRLEN], raddr[128], rport[10];
> +	int n, ret;
> +	FILE *fp;
> +
> +	switch (ovpn->cmd) {
> +	case CMD_NEW_IFACE:
> +		ret = ovpn_new_iface(ovpn);
> +		break;
> +	case CMD_DEL_IFACE:
> +		ret = ovpn_del_iface(ovpn);
> +		break;
> +	case CMD_LISTEN:
> +		ret = ovpn_listen(ovpn, ovpn->sa_family);
> +		if (ret < 0) {
> +			fprintf(stderr, "cannot listen on TCP socket\n");
> +			return ret;
> +		}
> +
> +		fp = fopen(ovpn->peers_file, "r");
> +		if (!fp) {
> +			fprintf(stderr, "cannot open file: %s\n",
> +				ovpn->peers_file);
> +			return -1;
> +		}
> +
> +		while ((n = fscanf(fp, "%s %s\n", peer_id, vpnip)) == 2) {
> +			struct ovpn_ctx peer_ctx = { 0 };
> +
> +			peer_ctx.ifindex = ovpn->ifindex;
> +			peer_ctx.sa_family = ovpn->sa_family;
> +
> +			peer_ctx.socket = ovpn_accept(ovpn);
> +			if (peer_ctx.socket < 0) {
> +				fprintf(stderr, "cannot accept connection!\n");
> +				return -1;
> +			}
> +
> +			/* store the socket of the first peer to test TCP I/O */
> +			if (ovpn->cli_socket < 0)
> +				ovpn->cli_socket = peer_ctx.socket;
> +
> +			ret = ovpn_parse_new_peer(&peer_ctx, peer_id, NULL,
> +						  NULL, vpnip);
> +			if (ret < 0) {
> +				fprintf(stderr, "error while parsing line\n");
> +				return -1;
> +			}
> +
> +			ret = ovpn_new_peer(&peer_ctx, true);
> +			if (ret < 0) {
> +				fprintf(stderr,
> +					"cannot add peer to VPN: %s %s\n",
> +					peer_id, vpnip);
> +				return ret;
> +			}
> +		}
> +
> +		if (ovpn->cli_socket >= 0)
> +			ret = ovpn_recv_tcp_data(ovpn->cli_socket);
> +
> +		break;
> +	case CMD_CONNECT:
> +		ret = ovpn_connect(ovpn);
> +		if (ret < 0) {
> +			fprintf(stderr, "cannot connect TCP socket\n");
> +			return ret;
> +		}
> +
> +		ret = ovpn_new_peer(ovpn, true);
> +		if (ret < 0) {
> +			fprintf(stderr, "cannot add peer to VPN\n");
> +			close(ovpn->socket);
> +			return ret;
> +		}
> +
> +		if (ovpn->cipher != OVPN_CIPHER_ALG_NONE) {
> +			ret = ovpn_new_key(ovpn);
> +			if (ret < 0) {
> +				fprintf(stderr, "cannot set key\n");
> +				return ret;
> +			}
> +		}
> +
> +		ret = ovpn_send_tcp_data(ovpn->socket);
> +		break;
> +	case CMD_NEW_PEER:
> +		ret = ovpn_udp_socket(ovpn, AF_INET6); //ovpn->sa_family ?
> +		if (ret < 0)
> +			return ret;
> +
> +		ret = ovpn_new_peer(ovpn, false);
> +		break;
> +	case CMD_NEW_MULTI_PEER:
> +		ret = ovpn_udp_socket(ovpn, AF_INET6);
> +		if (ret < 0)
> +			return ret;
> +
> +		fp = fopen(ovpn->peers_file, "r");
> +		if (!fp) {
> +			fprintf(stderr, "cannot open file: %s\n",
> +				ovpn->peers_file);
> +			return -1;
> +		}
> +
> +		while ((n = fscanf(fp, "%s %s %s %s\n", peer_id, raddr, rport,
> +				   vpnip)) == 4) {
> +			struct ovpn_ctx peer_ctx = { 0 };
> +
> +			peer_ctx.ifindex = ovpn->ifindex;
> +			peer_ctx.socket = ovpn->socket;
> +			peer_ctx.sa_family = AF_UNSPEC;
> +
> +			ret = ovpn_parse_new_peer(&peer_ctx, peer_id, raddr,
> +						  rport, vpnip);
> +			if (ret < 0) {
> +				fprintf(stderr, "error while parsing line\n");
> +				return -1;
> +			}
> +
> +			ret = ovpn_new_peer(&peer_ctx, false);
> +			if (ret < 0) {
> +				fprintf(stderr,
> +					"cannot add peer to VPN: %s %s %s %s\n",
> +					peer_id, raddr, rport, vpnip);
> +				return ret;
> +			}
> +		}
> +		break;
> +	case CMD_SET_PEER:
> +		ret = ovpn_set_peer(ovpn);
> +		break;
> +	case CMD_DEL_PEER:
> +		ret = ovpn_del_peer(ovpn);
> +		break;
> +	case CMD_GET_PEER:
> +		if (ovpn->peer_id == PEER_ID_UNDEF)
> +			fprintf(stderr, "List of peers connected to: %s\n",
> +				ovpn->ifname);
> +
> +		ret = ovpn_get_peer(ovpn);
> +		break;
> +	case CMD_NEW_KEY:
> +		ret = ovpn_new_key(ovpn);
> +		break;
> +	case CMD_DEL_KEY:
> +		ret = ovpn_del_key(ovpn);
> +		break;
> +	case CMD_GET_KEY:
> +		ret = ovpn_get_key(ovpn);
> +		break;
> +	case CMD_SWAP_KEYS:
> +		ret = ovpn_swap_keys(ovpn);
> +		break;
> +	case CMD_LISTEN_MCAST:
> +		ret = ovpn_listen_mcast();
> +		break;
> +	case CMD_INVALID:
> +		break;
> +	}
> +
> +	return ret;
> +}
> +
> +static int ovpn_parse_cmd_args(struct ovpn_ctx *ovpn, int argc, char *argv[])
> +{
> +	int ret;
> +
> +	/* no args required for LISTEN_MCAST */
> +	if (ovpn->cmd == CMD_LISTEN_MCAST)
> +		return 0;
> +
> +	/* all commands need an ifname */
> +	if (argc < 3)
> +		return -EINVAL;
> +
> +	strscpy(ovpn->ifname, argv[2], IFNAMSIZ - 1);
> +	ovpn->ifname[IFNAMSIZ - 1] = '\0';
> +
> +	/* all commands, except NEW_IFNAME, needs an ifindex */
> +	if (ovpn->cmd != CMD_NEW_IFACE) {
> +		ovpn->ifindex = if_nametoindex(ovpn->ifname);
> +		if (!ovpn->ifindex) {
> +			fprintf(stderr, "cannot find interface: %s\n",
> +				strerror(errno));
> +			return -1;
> +		}
> +	}
> +
> +	switch (ovpn->cmd) {
> +	case CMD_NEW_IFACE:
> +		if (argc < 4)
> +			break;
> +
> +		if (!strcmp(argv[3], "P2P")) {
> +			ovpn->mode = OVPN_MODE_P2P;
> +		} else if (!strcmp(argv[3], "MP")) {
> +			ovpn->mode = OVPN_MODE_MP;
> +		} else {
> +			fprintf(stderr, "Cannot parse iface mode: %s\n",
> +				argv[3]);
> +			return -1;
> +		}
> +		ovpn->mode_set = true;
> +		break;
> +	case CMD_DEL_IFACE:
> +		break;
> +	case CMD_LISTEN:
> +		if (argc < 5)
> +			return -EINVAL;
> +
> +		ovpn->lport = strtoul(argv[3], NULL, 10);
> +		if (errno == ERANGE || ovpn->lport > 65535) {
> +			fprintf(stderr, "lport value out of range\n");
> +			return -1;
> +		}
> +
> +		ovpn->peers_file = argv[4];
> +
> +		if (argc > 5 && !strcmp(argv[5], "ipv6"))
> +			ovpn->sa_family = AF_INET6;
> +		break;
> +	case CMD_CONNECT:
> +		if (argc < 6)
> +			return -EINVAL;
> +
> +		ovpn->sa_family = AF_INET;
> +
> +		ret = ovpn_parse_new_peer(ovpn, argv[3], argv[4], argv[5],
> +					  NULL);
> +		if (ret < 0) {
> +			fprintf(stderr, "Cannot parse remote peer data\n");
> +			return -1;
> +		}
> +
> +		if (argc > 6) {
> +			ovpn->key_slot = OVPN_KEY_SLOT_PRIMARY;
> +			ovpn->key_id = 0;
> +			ovpn->cipher = OVPN_CIPHER_ALG_AES_GCM;
> +			ovpn->key_dir = KEY_DIR_OUT;
> +
> +			ret = ovpn_parse_key(argv[6], ovpn);
> +			if (ret)
> +				return -1;
> +		}
> +		break;
> +	case CMD_NEW_PEER:
> +		if (argc < 7)
> +			return -EINVAL;
> +
> +		ovpn->lport = strtoul(argv[4], NULL, 10);
> +		if (errno == ERANGE || ovpn->lport > 65535) {
> +			fprintf(stderr, "lport value out of range\n");
> +			return -1;
> +		}
> +
> +		const char *vpnip = (argc > 7) ? argv[7] : NULL;
> +
> +		ret = ovpn_parse_new_peer(ovpn, argv[3], argv[5], argv[6],
> +					  vpnip);
> +		if (ret < 0)
> +			return -1;
> +		break;
> +	case CMD_NEW_MULTI_PEER:
> +		if (argc < 5)
> +			return -EINVAL;
> +
> +		ovpn->lport = strtoul(argv[3], NULL, 10);
> +		if (errno == ERANGE || ovpn->lport > 65535) {
> +			fprintf(stderr, "lport value out of range\n");
> +			return -1;
> +		}
> +
> +		ovpn->peers_file = argv[4];
> +		break;
> +	case CMD_SET_PEER:
> +		if (argc < 6)
> +			return -EINVAL;
> +
> +		ovpn->peer_id = strtoul(argv[3], NULL, 10);
> +		if (errno == ERANGE || ovpn->peer_id > PEER_ID_UNDEF) {
> +			fprintf(stderr, "peer ID value out of range\n");
> +			return -1;
> +		}
> +
> +		ovpn->keepalive_interval = strtoul(argv[4], NULL, 10);
> +		if (errno == ERANGE) {
> +			fprintf(stderr,
> +				"keepalive interval value out of range\n");
> +			return -1;
> +		}
> +
> +		ovpn->keepalive_timeout = strtoul(argv[5], NULL, 10);
> +		if (errno == ERANGE) {
> +			fprintf(stderr,
> +				"keepalive interval value out of range\n");
> +			return -1;
> +		}
> +		break;
> +	case CMD_DEL_PEER:
> +		if (argc < 4)
> +			return -EINVAL;
> +
> +		ovpn->peer_id = strtoul(argv[3], NULL, 10);
> +		if (errno == ERANGE || ovpn->peer_id > PEER_ID_UNDEF) {
> +			fprintf(stderr, "peer ID value out of range\n");
> +			return -1;
> +		}
> +		break;
> +	case CMD_GET_PEER:
> +		ovpn->peer_id = PEER_ID_UNDEF;
> +		if (argc > 3) {
> +			ovpn->peer_id = strtoul(argv[3], NULL, 10);
> +			if (errno == ERANGE || ovpn->peer_id > PEER_ID_UNDEF) {
> +				fprintf(stderr, "peer ID value out of range\n");
> +				return -1;
> +			}
> +		}
> +		break;
> +	case CMD_NEW_KEY:
> +		if (argc < 9)
> +			return -EINVAL;
> +
> +		ovpn->peer_id = strtoul(argv[3], NULL, 10);
> +		if (errno == ERANGE) {
> +			fprintf(stderr, "peer ID value out of range\n");
> +			return -1;
> +		}
> +
> +		ret = ovpn_parse_key_slot(argv[4], ovpn);
> +		if (ret)
> +			return -1;
> +
> +		ovpn->key_id = strtoul(argv[5], NULL, 10);
> +		if (errno == ERANGE || ovpn->key_id > 2) {
> +			fprintf(stderr, "key ID out of range\n");
> +			return -1;
> +		}
> +
> +		ret = ovpn_parse_cipher(argv[6], ovpn);
> +		if (ret < 0)
> +			return -1;
> +
> +		ret = ovpn_parse_key_direction(argv[7], ovpn);
> +		if (ret < 0)
> +			return -1;
> +
> +		ret = ovpn_parse_key(argv[8], ovpn);
> +		if (ret)
> +			return -1;
> +		break;
> +	case CMD_DEL_KEY:
> +		if (argc < 4)
> +			return -EINVAL;
> +
> +		ovpn->peer_id = strtoul(argv[3], NULL, 10);
> +		if (errno == ERANGE) {
> +			fprintf(stderr, "peer ID value out of range\n");
> +			return -1;
> +		}
> +
> +		ret = ovpn_parse_key_slot(argv[4], ovpn);
> +		if (ret)
> +			return ret;
> +		break;
> +	case CMD_GET_KEY:
> +		if (argc < 5)
> +			return -EINVAL;
> +
> +		ovpn->peer_id = strtoul(argv[3], NULL, 10);
> +		if (errno == ERANGE) {
> +			fprintf(stderr, "peer ID value out of range\n");
> +			return -1;
> +		}
> +
> +		ret = ovpn_parse_key_slot(argv[4], ovpn);
> +		if (ret)
> +			return ret;
> +		break;
> +	case CMD_SWAP_KEYS:
> +		if (argc < 4)
> +			return -EINVAL;
> +
> +		ovpn->peer_id = strtoul(argv[3], NULL, 10);
> +		if (errno == ERANGE) {
> +			fprintf(stderr, "peer ID value out of range\n");
> +			return -1;
> +		}
> +		break;
> +	case CMD_LISTEN_MCAST:
> +		break;
> +	case CMD_INVALID:
> +		break;
> +	}
> +
> +	return 0;
> +}
> +
> +int main(int argc, char *argv[])
> +{
> +	struct ovpn_ctx ovpn;
> +	int ret;
> +
> +	if (argc < 2) {
> +		usage(argv[0]);
> +		return -1;
> +	}
> +
> +	memset(&ovpn, 0, sizeof(ovpn));
> +	ovpn.sa_family = AF_INET;
> +	ovpn.cipher = OVPN_CIPHER_ALG_NONE;
> +	ovpn.cli_socket = -1;
> +
> +	ovpn.cmd = ovpn_parse_cmd(argv[1]);
> +	if (ovpn.cmd == CMD_INVALID) {
> +		fprintf(stderr, "Error: unknown command.\n\n");
> +		usage(argv[0]);
> +		return -1;
> +	}
> +
> +	ret = ovpn_parse_cmd_args(&ovpn, argc, argv);
> +	if (ret < 0) {
> +		fprintf(stderr, "Error: invalid arguments.\n\n");
> +		if (ret == -EINVAL)
> +			usage(argv[0]);
> +		return ret;
> +	}
> +
> +	ret = ovpn_run_cmd(&ovpn);
> +	if (ret)
> +		fprintf(stderr, "Cannot execute command: %s (%d)\n",
> +			strerror(-ret), ret);
> +
> +	return ret;
> +}
> diff --git a/tools/testing/selftests/net/ovpn/tcp_peers.txt b/tools/testing/selftests/net/ovpn/tcp_peers.txt
> new file mode 100644
> index 0000000000000000000000000000000000000000..d753eebe8716ed3588334ad766981e883ed2469a
> --- /dev/null
> +++ b/tools/testing/selftests/net/ovpn/tcp_peers.txt
> @@ -0,0 +1,5 @@
> +1 5.5.5.2
> +2 5.5.5.3
> +3 5.5.5.4
> +4 5.5.5.5
> +5 5.5.5.6
> diff --git a/tools/testing/selftests/net/ovpn/test-chachapoly.sh b/tools/testing/selftests/net/ovpn/test-chachapoly.sh
> new file mode 100755
> index 0000000000000000000000000000000000000000..79788f10d33b9682ed27590a48d136eb50b2202c
> --- /dev/null
> +++ b/tools/testing/selftests/net/ovpn/test-chachapoly.sh
> @@ -0,0 +1,9 @@
> +#!/bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (C) 2024 OpenVPN, Inc.
> +#
> +#  Author:	Antonio Quartulli <antonio@...nvpn.net>
> +
> +ALG="chachapoly"
> +
> +source test.sh
> diff --git a/tools/testing/selftests/net/ovpn/test-float.sh b/tools/testing/selftests/net/ovpn/test-float.sh
> new file mode 100755
> index 0000000000000000000000000000000000000000..93e1b729861d6b3f9f3f2e19d84e524c293ee3cf
> --- /dev/null
> +++ b/tools/testing/selftests/net/ovpn/test-float.sh
> @@ -0,0 +1,9 @@
> +#!/bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (C) 2024 OpenVPN, Inc.
> +#
> +#  Author:	Antonio Quartulli <antonio@...nvpn.net>
> +
> +FLOAT="1"
> +
> +source test.sh
> diff --git a/tools/testing/selftests/net/ovpn/test-tcp.sh b/tools/testing/selftests/net/ovpn/test-tcp.sh
> new file mode 100755
> index 0000000000000000000000000000000000000000..7542f595cc5696396513ed029cb96fe3b922d0e4
> --- /dev/null
> +++ b/tools/testing/selftests/net/ovpn/test-tcp.sh
> @@ -0,0 +1,9 @@
> +#!/bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (C) 2024 OpenVPN, Inc.
> +#
> +#  Author:	Antonio Quartulli <antonio@...nvpn.net>
> +
> +PROTO="TCP"
> +
> +source test.sh
> diff --git a/tools/testing/selftests/net/ovpn/test.sh b/tools/testing/selftests/net/ovpn/test.sh
> new file mode 100755
> index 0000000000000000000000000000000000000000..07f3a82df8f3cb8e4d18cc4cbbee3bd6880396b0
> --- /dev/null
> +++ b/tools/testing/selftests/net/ovpn/test.sh
> @@ -0,0 +1,183 @@
> +#!/bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (C) 2020-2024 OpenVPN, Inc.
> +#
> +#  Author:	Antonio Quartulli <antonio@...nvpn.net>
> +
> +#set -x
> +set -e
> +
> +UDP_PEERS_FILE=${UDP_PEERS_FILE:-udp_peers.txt}
> +TCP_PEERS_FILE=${TCP_PEERS_FILE:-tcp_peers.txt}
> +OVPN_CLI=${OVPN_CLI:-./ovpn-cli}
> +ALG=${ALG:-aes}
> +PROTO=${PROTO:-UDP}
> +FLOAT=${FLOAT:-0}
> +
> +create_ns() {
> +	ip netns add peer${1}
> +}
> +
> +setup_ns() {
> +	MODE="P2P"
> +
> +	if [ ${1} -eq 0 ]; then
> +		MODE="MP"
> +		for p in $(seq 1 ${NUM_PEERS}); do
> +			ip link add veth${p} netns peer0 type veth peer name veth${p} netns peer${p}
> +
> +			ip -n peer0 addr add 10.10.${p}.1/24 dev veth${p}
> +			ip -n peer0 link set veth${p} up
> +
> +			ip -n peer${p} addr add 10.10.${p}.2/24 dev veth${p}
> +			ip -n peer${p} link set veth${p} up
> +		done
> +	fi
> +
> +	ip netns exec peer${1} ${OVPN_CLI} new_iface tun${1} $MODE
> +	ip -n peer${1} addr add ${2} dev tun${1}
> +	ip -n peer${1} link set tun${1} up
> +}
> +
> +add_peer() {
> +	if [ "${PROTO}" == "UDP" ]; then
> +		if [ ${1} -eq 0 ]; then
> +			ip netns exec peer0 ${OVPN_CLI} new_multi_peer tun0 1 ${UDP_PEERS_FILE}
> +
> +			for p in $(seq 1 ${NUM_PEERS}); do
> +				ip netns exec peer0 ${OVPN_CLI} new_key tun0 ${p} 1 0 ${ALG} 0 \
> +					data64.key
> +			done
> +		else
> +			ip netns exec peer${1} ${OVPN_CLI} new_peer tun${1} ${1} 1 10.10.${1}.1 1
> +			ip netns exec peer${1} ${OVPN_CLI} new_key tun${1} ${1} 1 0 ${ALG} 1 \
> +				data64.key
> +		fi
> +	else
> +		if [ ${1} -eq 0 ]; then
> +			(ip netns exec peer0 ${OVPN_CLI} listen tun0 1 ${TCP_PEERS_FILE} && {
> +				for p in $(seq 1 ${NUM_PEERS}); do
> +					ip netns exec peer0 ${OVPN_CLI} new_key tun0 ${p} 1 0 \
> +						${ALG} 0 data64.key
> +				done
> +			}) &
> +			sleep 5
> +		else
> +			ip netns exec peer${1} ${OVPN_CLI} connect tun${1} ${1} 10.10.${1}.1 1 \
> +				data64.key
> +		fi
> +	fi
> +}
> +
> +cleanup() {
> +	for p in $(seq 1 10); do
> +		ip -n peer0 link del veth${p} 2>/dev/null || true
> +	done
> +	for p in $(seq 0 10); do
> +		ip netns exec peer${p} ${OVPN_CLI} del_iface tun${p} 2>/dev/null || true
> +		ip netns del peer${p} 2>/dev/null || true
> +	done
> +}
> +
> +if [ "${PROTO}" == "UDP" ]; then
> +	NUM_PEERS=${NUM_PEERS:-$(wc -l ${UDP_PEERS_FILE} | awk '{print $1}')}
> +else
> +	NUM_PEERS=${NUM_PEERS:-$(wc -l ${TCP_PEERS_FILE} | awk '{print $1}')}
> +fi
> +
> +cleanup
> +
> +modprobe -q ovpn || true
> +
> +for p in $(seq 0 ${NUM_PEERS}); do
> +	create_ns ${p}
> +done
> +
> +for p in $(seq 0 ${NUM_PEERS}); do
> +	setup_ns ${p} 5.5.5.$((${p} + 1))/24
> +done
> +
> +for p in $(seq 0 ${NUM_PEERS}); do
> +	add_peer ${p}
> +done
> +
> +for p in $(seq 1 ${NUM_PEERS}); do
> +	ip netns exec peer0 ${OVPN_CLI} set_peer tun0 ${p} 60 120
> +	ip netns exec peer${p} ${OVPN_CLI} set_peer tun${p} ${p} 60 120
> +done
> +
> +for p in $(seq 1 ${NUM_PEERS}); do
> +	ip netns exec peer0 ping -qfc 1000 -w 5 5.5.5.$((${p} + 1))
> +done
> +
> +if [ "$FLOAT" == "1" ]; then
> +	# make clients float..
> +	for p in $(seq 1 ${NUM_PEERS}); do
> +		ip -n peer${p} addr del 10.10.${p}.2/24 dev veth${p}
> +		ip -n peer${p} addr add 10.10.${p}.3/24 dev veth${p}
> +	done
> +	for p in $(seq 1 ${NUM_PEERS}); do
> +		ip netns exec peer${p} ping -qfc 1000 -w 5 5.5.5.1
> +	done
> +fi
> +
> +ip netns exec peer0 iperf3 -1 -s &
> +sleep 1
> +ip netns exec peer1 iperf3 -Z -t 3 -c 5.5.5.1
> +
> +echo "Adding secondary key and then swap:"
> +for p in $(seq 1 ${NUM_PEERS}); do
> +	ip netns exec peer0 ${OVPN_CLI} new_key tun0 ${p} 2 1 ${ALG} 0 data64.key
> +	ip netns exec peer${p} ${OVPN_CLI} new_key tun${p} ${p} 2 1 ${ALG} 1 data64.key
> +	ip netns exec peer${p} ${OVPN_CLI} swap_keys tun${p} ${p}
> +done
> +
> +sleep 1
> +echo "Querying all peers:"
> +ip netns exec peer0 ${OVPN_CLI} get_peer tun0
> +ip netns exec peer1 ${OVPN_CLI} get_peer tun1
> +
> +echo "Querying peer 1:"
> +ip netns exec peer0 ${OVPN_CLI} get_peer tun0 1
> +
> +echo "Querying non-existent peer 10:"
> +ip netns exec peer0 ${OVPN_CLI} get_peer tun0 10 || true
> +
> +echo "Deleting peer 1:"
> +ip netns exec peer0 ${OVPN_CLI} del_peer tun0 1
> +ip netns exec peer1 ${OVPN_CLI} del_peer tun1 1
> +
> +echo "Querying keys:"
> +for p in $(seq 2 ${NUM_PEERS}); do
> +	ip netns exec peer${p} ${OVPN_CLI} get_key tun${p} ${p} 1
> +	ip netns exec peer${p} ${OVPN_CLI} get_key tun${p} ${p} 2
> +done
> +
> +echo "Deleting keys:"
> +for p in $(seq 2 ${NUM_PEERS}); do
> +	ip netns exec peer${p} ${OVPN_CLI} del_key tun${p} ${p} 1
> +	ip netns exec peer${p} ${OVPN_CLI} del_key tun${p} ${p} 2
> +done
> +
> +echo "Setting timeout to 10s MP:"
> +# bring ifaces down to prevent traffic being sent
> +for p in $(seq 0 ${NUM_PEERS}); do
> +	ip -n peer${p} link set tun${p} down
> +done
> +# set short timeout
> +for p in $(seq 2 ${NUM_PEERS}); do
> +	ip netns exec peer0 ${OVPN_CLI} set_peer tun0 ${p} 10 10 || true
> +	ip netns exec peer${p} ${OVPN_CLI} set_peer tun${p} ${p} 0 0
> +done
> +# wait for peers to timeout
> +sleep 15
> +
> +echo "Setting timeout to 10s P2P:"
> +for p in $(seq 2 ${NUM_PEERS}); do
> +	ip netns exec peer${p} ${OVPN_CLI} set_peer tun${p} ${p} 10 10
> +done
> +sleep 15
> +
> +cleanup
> +
> +modprobe -r ovpn || true
> diff --git a/tools/testing/selftests/net/ovpn/udp_peers.txt b/tools/testing/selftests/net/ovpn/udp_peers.txt
> new file mode 100644
> index 0000000000000000000000000000000000000000..32f14bd9347a63e58438311b6d880b9fef768aa2
> --- /dev/null
> +++ b/tools/testing/selftests/net/ovpn/udp_peers.txt
> @@ -0,0 +1,5 @@
> +1 10.10.1.2 1 5.5.5.2
> +2 10.10.2.2 1 5.5.5.3
> +3 10.10.3.2 1 5.5.5.4
> +4 10.10.4.2 1 5.5.5.5
> +5 10.10.5.2 1 5.5.5.6
> 


thanks,
-- Shuah

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