+
+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");
+}
