/* SPDX-License-Identifier: LGPL-2.1+ */

#include <linux/fou.h>

#include <net/if.h>

#include <netinet/in.h>

#include <linux/ip.h>

#include "conf-parser.h"

#include "ip-protocol-list.h"

#include "missing.h"

#include "netdev/fou-tunnel.h"

#include "netlink-util.h"

#include "networkd-link.h"

#include "networkd-manager.h"

#include "parse-util.h"

#include "sd-netlink.h"

#include "string-table.h"

#include "string-util.h"

#include "util.h"

static const char* const fou_encap_type_table[_NETDEV_FOO_OVER_UDP_ENCAP_MAX] = {

        [NETDEV_FOO_OVER_UDP_ENCAP_DIRECT] = "FooOverUDP",

        [NETDEV_FOO_OVER_UDP_ENCAP_GUE] = "GenericUDPEncapsulation",

};

DEFINE_STRING_TABLE_LOOKUP(fou_encap_type, FooOverUDPEncapType);

DEFINE_CONFIG_PARSE_ENUM(config_parse_fou_encap_type, fou_encap_type, FooOverUDPEncapType,

                         "Failed to parse Encapsulation=");

static int netdev_fill_fou_tunnel_message(NetDev *netdev, sd_netlink_message **ret) {

        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;

        FouTunnel *t;

        uint8_t encap_type;

        int r;

        assert(netdev);

        t = FOU(netdev);

        assert(t);

        r = sd_genl_message_new(netdev->manager->genl, SD_GENL_FOU, FOU_CMD_ADD, &m);

        if (r < 0)

                return log_netdev_error_errno(netdev, r, "Failed to allocate generic netlink message: %m");

        r = sd_netlink_message_append_u16(m, FOU_ATTR_PORT, htobe16(t->port));

        if (r < 0)

                return log_netdev_error_errno(netdev, r, "Could not append FOU_ATTR_PORT attribute: %m");

        if (IN_SET(t->peer_family, AF_INET, AF_INET6)) {

                r = sd_netlink_message_append_u16(m, FOU_ATTR_PEER_PORT, htobe16(t->peer_port));

                if (r < 0)

                        return log_netdev_error_errno(netdev, r, "Could not append FOU_ATTR_PEER_PORT attribute: %m");

        }

        switch (t->fou_encap_type) {

        case NETDEV_FOO_OVER_UDP_ENCAP_DIRECT:

                encap_type = FOU_ENCAP_DIRECT;

                break;

        case NETDEV_FOO_OVER_UDP_ENCAP_GUE:

                encap_type = FOU_ENCAP_GUE;

                break;

        default:

                assert_not_reached("invalid encap type");

        }

        r = sd_netlink_message_append_u8(m, FOU_ATTR_TYPE, encap_type);

        if (r < 0)

                return log_netdev_error_errno(netdev, r, "Could not append FOU_ATTR_TYPE attribute: %m");

        r = sd_netlink_message_append_u8(m, FOU_ATTR_AF, AF_INET);

        if (r < 0)

                return log_netdev_error_errno(netdev, r, "Could not append FOU_ATTR_AF attribute: %m");

        r = sd_netlink_message_append_u8(m, FOU_ATTR_IPPROTO, t->fou_protocol);

        if (r < 0)

                return log_netdev_error_errno(netdev, r, "Could not append FOU_ATTR_IPPROTO attribute: %m");

        if (t->local_family == AF_INET) {

                r = sd_netlink_message_append_in_addr(m, FOU_ATTR_LOCAL_V4, &t->local.in);

                if (r < 0)

                        return log_netdev_error_errno(netdev, r, "Could not append FOU_ATTR_LOCAL_V4 attribute: %m");

        } else if (t->local_family == AF_INET6) {

                r = sd_netlink_message_append_in6_addr(m, FOU_ATTR_LOCAL_V6, &t->local.in6);

                if (r < 0)

                        return log_netdev_error_errno(netdev, r, "Could not append FOU_ATTR_LOCAL_V6 attribute: %m");

        }

        if (t->peer_family == AF_INET) {

                r = sd_netlink_message_append_in_addr(m, FOU_ATTR_PEER_V4, &t->peer.in);

                if (r < 0)

                        return log_netdev_error_errno(netdev, r, "Could not append FOU_ATTR_PEER_V4 attribute: %m");

        } else if (t->peer_family == AF_INET6){

                r = sd_netlink_message_append_in6_addr(m, FOU_ATTR_PEER_V6, &t->peer.in6);

                if (r < 0)

                        return log_netdev_error_errno(netdev, r, "Could not append FOU_ATTR_PEER_V6 attribute: %m");

        }

        *ret = TAKE_PTR(m);

        return 0;

}

static int fou_tunnel_create_handler(sd_netlink *rtnl, sd_netlink_message *m, NetDev *netdev) {

        int r;

        assert(netdev);

        assert(netdev->state != _NETDEV_STATE_INVALID);

        r = sd_netlink_message_get_errno(m);

        if (r == -EEXIST)

                log_netdev_info(netdev, "netdev exists, using existing without changing its parameters");

        else if (r < 0) {

                log_netdev_warning_errno(netdev, r, "netdev could not be created: %m");

                netdev_drop(netdev);

                return 1;

        }

        log_netdev_debug(netdev, "FooOverUDP tunnel is created");

        return 1;

}

static int netdev_fou_tunnel_create(NetDev *netdev) {

        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;

        int r;

        assert(netdev);

        assert(FOU(netdev));

        r = netdev_fill_fou_tunnel_message(netdev, &m);

        if (r < 0)

                return r;

        r = netlink_call_async(netdev->manager->genl, NULL, m, fou_tunnel_create_handler,

                               netdev_destroy_callback, netdev);

        if (r < 0)

                return log_netdev_error_errno(netdev, r, "Failed to create FooOverUDP tunnel: %m");

        netdev_ref(netdev);

        return 0;

}

int config_parse_ip_protocol(

                const char *unit,

                const char *filename,

                unsigned line,

                const char *section,

                unsigned section_line,

                const char *lvalue,

                int ltype,

                const char *rvalue,

                void *data,

                void *userdata) {

        uint8_t *protocol = data;

        int r;

        assert(filename);

        assert(section);

        assert(lvalue);

        assert(rvalue);

        assert(data);

        assert_cc(IPPROTO_MAX-1 <= UINT8_MAX);

        r = parse_ip_protocol(rvalue);

        if (r < 0) {

                r = safe_atou8(rvalue, protocol);

                if (r < 0)

                        log_syntax(unit, LOG_ERR, filename, line, r,

                                   "Failed to parse IP protocol '%s' for Foo over UDP tunnel, "

                                   "ignoring assignment: %m", rvalue);

                return 0;

        }

        *protocol = r;

        return 0;

}

int config_parse_fou_tunnel_address(

                const char *unit,

                const char *filename,

                unsigned line,

                const char *section,

                unsigned section_line,

                const char *lvalue,

                int ltype,

                const char *rvalue,

                void *data,

                void *userdata) {

        union in_addr_union *addr = data;

        FouTunnel *t = userdata;

        int r, *f;

        assert(filename);

        assert(lvalue);

        assert(rvalue);

        assert(data);

        if (streq(lvalue, "Local"))

                f = &t->local_family;

        else

                f = &t->peer_family;

        r = in_addr_from_string_auto(rvalue, f, addr);

        if (r < 0)

                log_syntax(unit, LOG_ERR, filename, line, r,

                           "Foo over UDP tunnel '%s' address is invalid, ignoring assignment: %s",

                           lvalue, rvalue);

        return 0;

}

static int netdev_fou_tunnel_verify(NetDev *netdev, const char *filename) {

        FouTunnel *t;

        assert(netdev);

        assert(filename);

        t = FOU(netdev);

        assert(t);

        switch (t->fou_encap_type) {

        case NETDEV_FOO_OVER_UDP_ENCAP_DIRECT:

                if (t->fou_protocol <= 0)

                        return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL),

                                                      "FooOverUDP protocol not configured in %s. Rejecting configuration.",

                                                      filename);

                break;

        case NETDEV_FOO_OVER_UDP_ENCAP_GUE:

                if (t->fou_protocol > 0)

                        return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL),

                                                      "FooOverUDP GUE can't be set with protocol configured in %s. Rejecting configuration.",

                                                      filename);

                break;

        default:

                assert_not_reached("Invalid fou encap type");

        }

        if (t->peer_family == AF_UNSPEC && t->peer_port > 0)

                return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL),

                                              "FooOverUDP peer port is set but peer address not configured in %s. Rejecting configuration.",

                                              filename);

        else if (t->peer_family != AF_UNSPEC && t->peer_port == 0)

                return log_netdev_error_errno(netdev, SYNTHETIC_ERRNO(EINVAL),

                                              "FooOverUDP peer port not set but peer address is configured in %s. Rejecting configuration.",

                                              filename);

        return 0;

}

static void fou_tunnel_init(NetDev *netdev) {

        FouTunnel *t;

        assert(netdev);

        t = FOU(netdev);

        assert(t);

        t->fou_encap_type = NETDEV_FOO_OVER_UDP_ENCAP_DIRECT;

}

const NetDevVTable foutnl_vtable = {

        .object_size = sizeof(FouTunnel),

        .init = fou_tunnel_init,

        .sections = "Match\0NetDev\0FooOverUDP\0",

        .create = netdev_fou_tunnel_create,

        .create_type = NETDEV_CREATE_INDEPENDENT,

        .config_verify = netdev_fou_tunnel_verify,

};