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

#include <net/if.h>
#include <linux/fib_rules.h>

#include "af-list.h"
#include "alloc-util.h"
#include "conf-parser.h"
#include "fileio.h"
#include "ip-protocol-list.h"
#include "networkd-routing-policy-rule.h"
#include "netlink-util.h"
#include "networkd-manager.h"
#include "networkd-util.h"
#include "parse-util.h"
#include "socket-util.h"
#include "string-util.h"
#include "strv.h"

int routing_policy_rule_new(RoutingPolicyRule **ret) {
        RoutingPolicyRule *rule;

        rule = new(RoutingPolicyRule, 1);
        if (!rule)
                return -ENOMEM;

        *rule = (RoutingPolicyRule) {
                .table = RT_TABLE_MAIN,
        };

        *ret = rule;
        return 0;
}

void routing_policy_rule_free(RoutingPolicyRule *rule) {

        if (!rule)
                return;

        if (rule->network) {
                LIST_REMOVE(rules, rule->network->rules, rule);
                assert(rule->network->n_rules > 0);
                rule->network->n_rules--;

                if (rule->section)
                        hashmap_remove(rule->network->rules_by_section, rule->section);
        }

        if (rule->manager) {
                if (set_get(rule->manager->rules, rule) == rule)
                        set_remove(rule->manager->rules, rule);
                if (set_get(rule->manager->rules_foreign, rule) == rule)
                        set_remove(rule->manager->rules_foreign, rule);
        }

        network_config_section_free(rule->section);
        free(rule->iif);
        free(rule->oif);
        free(rule);
}

static int routing_policy_rule_copy(RoutingPolicyRule *dest, RoutingPolicyRule *src) {
        _cleanup_free_ char *iif = NULL, *oif = NULL;

        assert(dest);
        assert(src);

        if (src->iif) {
                iif = strdup(src->iif);
                if (!iif)
                        return -ENOMEM;
        }

        if (src->oif) {
                oif = strdup(src->oif);
                if (!oif)
                        return -ENOMEM;
        }

        dest->family = src->family;
        dest->from = src->from;
        dest->from_prefixlen = src->from_prefixlen;
        dest->to = src->to;
        dest->to_prefixlen = src->to_prefixlen;
        dest->invert_rule = src->invert_rule;
        dest->tos = src->tos;
        dest->fwmark = src->fwmark;
        dest->fwmask = src->fwmask;
        dest->priority = src->priority;
        dest->table = src->table;
        dest->iif = TAKE_PTR(iif);
        dest->oif = TAKE_PTR(oif);
        dest->protocol = src->protocol;
        dest->sport = src->sport;
        dest->dport = src->dport;

        return 0;
}

static void routing_policy_rule_hash_func(const RoutingPolicyRule *rule, struct siphash *state) {
        assert(rule);

        siphash24_compress(&rule->family, sizeof(rule->family), state);

        switch (rule->family) {
        case AF_INET:
        case AF_INET6:
                siphash24_compress(&rule->from, FAMILY_ADDRESS_SIZE(rule->family), state);
                siphash24_compress(&rule->from_prefixlen, sizeof(rule->from_prefixlen), state);

                siphash24_compress(&rule->to, FAMILY_ADDRESS_SIZE(rule->family), state);
                siphash24_compress(&rule->to_prefixlen, sizeof(rule->to_prefixlen), state);

                siphash24_compress_boolean(rule->invert_rule, state);

                siphash24_compress(&rule->tos, sizeof(rule->tos), state);
                siphash24_compress(&rule->fwmark, sizeof(rule->fwmark), state);
                siphash24_compress(&rule->fwmask, sizeof(rule->fwmask), state);
                siphash24_compress(&rule->priority, sizeof(rule->priority), state);
                siphash24_compress(&rule->table, sizeof(rule->table), state);

                siphash24_compress(&rule->protocol, sizeof(rule->protocol), state);
                siphash24_compress(&rule->sport, sizeof(rule->sport), state);
                siphash24_compress(&rule->dport, sizeof(rule->dport), state);

                if (rule->iif)
                        siphash24_compress(rule->iif, strlen(rule->iif), state);

                if (rule->oif)
                        siphash24_compress(rule->oif, strlen(rule->oif), state);

                break;
        default:
                /* treat any other address family as AF_UNSPEC */
                break;
        }
}

static int routing_policy_rule_compare_func(const RoutingPolicyRule *a, const RoutingPolicyRule *b) {
        int r;

        r = CMP(a->family, b->family);
        if (r != 0)
                return r;

        switch (a->family) {
        case AF_INET:
        case AF_INET6:
                r = CMP(a->from_prefixlen, b->from_prefixlen);
                if (r != 0)
                        return r;

                r = memcmp(&a->from, &b->from, FAMILY_ADDRESS_SIZE(a->family));
                if (r != 0)
                        return r;

                r = CMP(a->to_prefixlen, b->to_prefixlen);
                if (r != 0)
                        return r;

                r = memcmp(&a->to, &b->to, FAMILY_ADDRESS_SIZE(a->family));
                if (r != 0)
                        return r;

                r = CMP(a->invert_rule, b->invert_rule);
                if (r != 0)
                        return r;

                r = CMP(a->tos, b->tos);
                if (r != 0)
                        return r;

                r = CMP(a->fwmark, b->fwmark);
                if (r != 0)
                        return r;

                r = CMP(a->fwmask, b->fwmask);
                if (r != 0)
                        return r;

                r = CMP(a->priority, b->priority);
                if (r != 0)
                        return r;

                r = CMP(a->table, b->table);
                if (r != 0)
                        return r;

                r = CMP(a->protocol, b->protocol);
                if (r != 0)
                        return r;

                r = memcmp(&a->sport, &b->sport, sizeof(a->sport));
                if (r != 0)
                        return r;

                r = memcmp(&a->dport, &b->dport, sizeof(a->dport));
                if (r != 0)
                        return r;

                r = strcmp_ptr(a->iif, b->iif);
                if (r != 0)
                        return r;

                r = strcmp_ptr(a->oif, b->oif);
                if (r != 0)
                        return r;

                return 0;
        default:
                /* treat any other address family as AF_UNSPEC */
                return 0;
        }
}

DEFINE_PRIVATE_HASH_OPS(routing_policy_rule_hash_ops, RoutingPolicyRule, routing_policy_rule_hash_func, routing_policy_rule_compare_func);

int routing_policy_rule_get(Manager *m, RoutingPolicyRule *rule, RoutingPolicyRule **ret) {

        RoutingPolicyRule *existing;

        assert(m);

        existing = set_get(m->rules, rule);
        if (existing) {
                if (ret)
                        *ret = existing;
                return 1;
        }

        existing = set_get(m->rules_foreign, rule);
        if (existing) {
                if (ret)
                        *ret = existing;
                return 0;
        }

        return -ENOENT;
}

int routing_policy_rule_make_local(Manager *m, RoutingPolicyRule *rule) {
        int r;

        assert(m);

        if (set_contains(m->rules_foreign, rule)) {
                set_remove(m->rules_foreign, rule);

                r = set_ensure_allocated(&m->rules, &routing_policy_rule_hash_ops);
                if (r < 0)
                        return r;

                r = set_put(m->rules, rule);
                if (r < 0)
                        return r;
                if (r == 0)
                        routing_policy_rule_free(rule);
        }

        return -ENOENT;
}

static int routing_policy_rule_add_internal(Manager *m, Set **rules, RoutingPolicyRule *in, RoutingPolicyRule **ret) {
        _cleanup_(routing_policy_rule_freep) RoutingPolicyRule *rule = NULL;
        int r;

        assert(m);
        assert(rules);
        assert(in);

        r = routing_policy_rule_new(&rule);
        if (r < 0)
                return r;

        rule->manager = m;

        r = routing_policy_rule_copy(rule, in);
        if (r < 0)
                return r;

        r = set_ensure_allocated(rules, &routing_policy_rule_hash_ops);
        if (r < 0)
                return r;

        r = set_put(*rules, rule);
        if (r < 0)
                return r;
        if (r == 0)
                return -EEXIST;

        if (ret)
                *ret = rule;

        TAKE_PTR(rule);
        return 0;
}

static int routing_policy_rule_add(Manager *m, RoutingPolicyRule *rule, RoutingPolicyRule **ret) {
        return routing_policy_rule_add_internal(m, &m->rules, rule, ret);
}

int routing_policy_rule_add_foreign(Manager *m, RoutingPolicyRule *rule, RoutingPolicyRule **ret) {
        return routing_policy_rule_add_internal(m, &m->rules_foreign, rule, ret);
}

static int routing_policy_rule_remove_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *link) {
        int r;

        assert(m);
        assert(link);
        assert(link->ifname);

        link->routing_policy_rule_remove_messages--;

        if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER))
                return 1;

        r = sd_netlink_message_get_errno(m);
        if (r < 0)
                log_link_message_warning_errno(link, m, r, "Could not drop routing policy rule");

        return 1;
}

int routing_policy_rule_remove(RoutingPolicyRule *routing_policy_rule, Link *link, link_netlink_message_handler_t callback) {
        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
        int r;

        assert(routing_policy_rule);
        assert(link);
        assert(link->manager);
        assert(link->manager->rtnl);
        assert(link->ifindex > 0);
        assert(IN_SET(routing_policy_rule->family, AF_INET, AF_INET6));

        r = sd_rtnl_message_new_routing_policy_rule(link->manager->rtnl, &m, RTM_DELRULE, routing_policy_rule->family);
        if (r < 0)
                return log_error_errno(r, "Could not allocate RTM_DELRULE message: %m");

        if (in_addr_is_null(routing_policy_rule->family, &routing_policy_rule->from) == 0) {
                r = netlink_message_append_in_addr_union(m, FRA_SRC, routing_policy_rule->family, &routing_policy_rule->from);
                if (r < 0)
                        return log_error_errno(r, "Could not append FRA_SRC attribute: %m");

                r = sd_rtnl_message_routing_policy_rule_set_rtm_src_prefixlen(m, routing_policy_rule->from_prefixlen);
                if (r < 0)
                        return log_error_errno(r, "Could not set source prefix length: %m");
        }

        if (in_addr_is_null(routing_policy_rule->family, &routing_policy_rule->to) == 0) {
                r = netlink_message_append_in_addr_union(m, FRA_DST, routing_policy_rule->family, &routing_policy_rule->to);
                if (r < 0)
                        return log_error_errno(r, "Could not append FRA_DST attribute: %m");

                r = sd_rtnl_message_routing_policy_rule_set_rtm_dst_prefixlen(m, routing_policy_rule->to_prefixlen);
                if (r < 0)
                        return log_error_errno(r, "Could not set destination prefix length: %m");
        }

        r = netlink_call_async(link->manager->rtnl, NULL, m,
                               callback ?: routing_policy_rule_remove_handler,
                               link_netlink_destroy_callback, link);
        if (r < 0)
                return log_error_errno(r, "Could not send rtnetlink message: %m");

        link_ref(link);

        return 0;
}

static int routing_policy_rule_new_static(Network *network, const char *filename, unsigned section_line, RoutingPolicyRule **ret) {
        _cleanup_(routing_policy_rule_freep) RoutingPolicyRule *rule = NULL;
        _cleanup_(network_config_section_freep) NetworkConfigSection *n = NULL;
        int r;

        assert(network);
        assert(ret);
        assert(!!filename == (section_line > 0));

        if (filename) {
                r = network_config_section_new(filename, section_line, &n);
                if (r < 0)
                        return r;

                rule = hashmap_get(network->rules_by_section, n);
                if (rule) {
                        *ret = TAKE_PTR(rule);

                        return 0;
                }
        }

        r = routing_policy_rule_new(&rule);
        if (r < 0)
                return r;

        rule->network = network;
        LIST_APPEND(rules, network->rules, rule);
        network->n_rules++;

        if (filename) {
                rule->section = TAKE_PTR(n);

                r = hashmap_ensure_allocated(&network->rules_by_section, &network_config_hash_ops);
                if (r < 0)
                        return r;

                r = hashmap_put(network->rules_by_section, rule->section, rule);
                if (r < 0)
                        return r;
        }

        *ret = TAKE_PTR(rule);

        return 0;
}

static int routing_policy_rule_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *link) {
        int r;

        assert(rtnl);
        assert(m);
        assert(link);
        assert(link->ifname);
        assert(link->routing_policy_rule_messages > 0);

        link->routing_policy_rule_messages--;

        if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER))
                return 1;

        r = sd_netlink_message_get_errno(m);
        if (r < 0 && r != -EEXIST) {
                log_link_message_warning_errno(link, m, r, "Could not add routing policy rule");
                link_enter_failed(link);
                return 1;
        }

        if (link->routing_policy_rule_messages == 0) {
                log_link_debug(link, "Routing policy rule configured");
                link->routing_policy_rules_configured = true;
                link_check_ready(link);
        }

        return 1;
}

int routing_policy_rule_configure(RoutingPolicyRule *rule, Link *link, link_netlink_message_handler_t callback) {
        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
        int r;

        assert(rule);
        assert(link);
        assert(link->ifindex > 0);
        assert(link->manager);
        assert(link->manager->rtnl);

        if (DEBUG_LOGGING) {
                _cleanup_free_ char *from = NULL, *to = NULL;

                (void) in_addr_to_string(rule->family, &rule->from, &from);
                (void) in_addr_to_string(rule->family, &rule->to, &to);

                log_debug("Configuring routing policy rule: %s/%u -> %s/%u, iif: %s, oif: %s, table: %u",
                          from, rule->from_prefixlen, to, rule->to_prefixlen, strna(rule->iif), strna(rule->oif), rule->table);
        }

        r = sd_rtnl_message_new_routing_policy_rule(link->manager->rtnl, &m, RTM_NEWRULE, rule->family);
        if (r < 0)
                return log_error_errno(r, "Could not allocate RTM_NEWRULE message: %m");

        if (in_addr_is_null(rule->family, &rule->from) == 0) {
                r = netlink_message_append_in_addr_union(m, FRA_SRC, rule->family, &rule->from);
                if (r < 0)
                        return log_error_errno(r, "Could not append FRA_SRC attribute: %m");

                r = sd_rtnl_message_routing_policy_rule_set_rtm_src_prefixlen(m, rule->from_prefixlen);
                if (r < 0)
                        return log_error_errno(r, "Could not set source prefix length: %m");
        }

        if (in_addr_is_null(rule->family, &rule->to) == 0) {
                r = netlink_message_append_in_addr_union(m, FRA_DST, rule->family, &rule->to);
                if (r < 0)
                        return log_error_errno(r, "Could not append FRA_DST attribute: %m");

                r = sd_rtnl_message_routing_policy_rule_set_rtm_dst_prefixlen(m, rule->to_prefixlen);
                if (r < 0)
                        return log_error_errno(r, "Could not set destination prefix length: %m");
        }

        r = sd_netlink_message_append_u32(m, FRA_PRIORITY, rule->priority);
        if (r < 0)
                return log_error_errno(r, "Could not append FRA_PRIORITY attribute: %m");

        if (rule->tos > 0) {
                r = sd_rtnl_message_routing_policy_rule_set_tos(m, rule->tos);
                if (r < 0)
                        return log_error_errno(r, "Could not set ip rule tos: %m");
        }

        if (rule->table < 256) {
                r = sd_rtnl_message_routing_policy_rule_set_table(m, rule->table);
                if (r < 0)
                        return log_error_errno(r, "Could not set ip rule table: %m");
        } else {
                r = sd_rtnl_message_routing_policy_rule_set_table(m, RT_TABLE_UNSPEC);
                if (r < 0)
                        return log_error_errno(r, "Could not set ip rule table: %m");

                r = sd_netlink_message_append_u32(m, FRA_TABLE, rule->table);
                if (r < 0)
                        return log_error_errno(r, "Could not append FRA_TABLE attribute: %m");
        }

        if (rule->fwmark > 0) {
                r = sd_netlink_message_append_u32(m, FRA_FWMARK, rule->fwmark);
                if (r < 0)
                        return log_error_errno(r, "Could not append FRA_FWMARK attribute: %m");
        }

        if (rule->fwmask > 0) {
                r = sd_netlink_message_append_u32(m, FRA_FWMASK, rule->fwmask);
                if (r < 0)
                        return log_error_errno(r, "Could not append FRA_FWMASK attribute: %m");
        }

        if (rule->iif) {
                r = sd_netlink_message_append_string(m, FRA_IFNAME, rule->iif);
                if (r < 0)
                        return log_error_errno(r, "Could not append FRA_IFNAME attribute: %m");
        }

        if (rule->oif) {
                r = sd_netlink_message_append_string(m, FRA_OIFNAME, rule->oif);
                if (r < 0)
                        return log_error_errno(r, "Could not append FRA_OIFNAME attribute: %m");
        }

        r = sd_netlink_message_append_u8(m, FRA_IP_PROTO, rule->protocol);
        if (r < 0)
                return log_error_errno(r, "Could not append FRA_IP_PROTO attribute: %m");

        if (rule->sport.start != 0 || rule->sport.end != 0) {
                r = sd_netlink_message_append_data(m, FRA_SPORT_RANGE, &rule->sport, sizeof(rule->sport));
                if (r < 0)
                        return log_error_errno(r, "Could not append FRA_SPORT_RANGE attribute: %m");
        }

        if (rule->dport.start != 0 || rule->dport.end != 0) {
                r = sd_netlink_message_append_data(m, FRA_DPORT_RANGE, &rule->dport, sizeof(rule->dport));
                if (r < 0)
                        return log_error_errno(r, "Could not append FRA_DPORT_RANGE attribute: %m");
        }

        if (rule->invert_rule) {
                r = sd_rtnl_message_routing_policy_rule_set_flags(m, FIB_RULE_INVERT);
                if (r < 0)
                        return log_error_errno(r, "Could not append FIB_RULE_INVERT attribute: %m");
        }

        rule->link = link;

        r = netlink_call_async(link->manager->rtnl, NULL, m,
                               callback ?: routing_policy_rule_handler,
                               link_netlink_destroy_callback, link);
        if (r < 0)
                return log_error_errno(r, "Could not send rtnetlink message: %m");

        link_ref(link);

        r = routing_policy_rule_add(link->manager, rule, NULL);
        if (r < 0)
                return log_error_errno(r, "Could not add rule: %m");

        return 1;
}

int routing_policy_rule_section_verify(RoutingPolicyRule *rule) {
        int r;

        if (section_is_invalid(rule->section))
                return -EINVAL;

        if ((rule->family == AF_INET && FLAGS_SET(rule->address_family, ADDRESS_FAMILY_IPV6)) ||
            (rule->family == AF_INET6 && FLAGS_SET(rule->address_family, ADDRESS_FAMILY_IPV4)))
                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                "%s: address family specified by Family= conflicts with the address "
                                "specified by To= or From=. Ignoring [RoutingPolicyRule] section from line %u.",
                                rule->section->filename, rule->section->line);

        if (FLAGS_SET(rule->address_family, ADDRESS_FAMILY_IPV4 | ADDRESS_FAMILY_IPV6)) {
                _cleanup_(routing_policy_rule_freep) RoutingPolicyRule *rule6 = NULL;

                assert(rule->family == AF_UNSPEC);

                /* When Family=both, we need to copy the section, AF_INET and AF_INET6. */

                r = routing_policy_rule_new_static(rule->network, NULL, 0, &rule6);
                if (r < 0)
                        return r;

                r = routing_policy_rule_copy(rule6, rule);
                if (r < 0)
                        return r;

                rule->family = AF_INET;
                rule6->family = AF_INET6;

                TAKE_PTR(rule6);
        }

        if (rule->family == AF_UNSPEC) {
                if (FLAGS_SET(rule->address_family, ADDRESS_FAMILY_IPV6))
                        rule->family = AF_INET6;
                else
                        rule->family = AF_INET;
        }

        return 0;
}

static int parse_fwmark_fwmask(const char *s, uint32_t *fwmark, uint32_t *fwmask) {
        _cleanup_free_ char *f = NULL;
        char *p;
        int r;

        assert(s);

        f = strdup(s);
        if (!f)
                return -ENOMEM;

        p = strchr(f, '/');
        if (p)
                *p++ = '\0';

        r = safe_atou32(f, fwmark);
        if (r < 0)
                return log_error_errno(r, "Failed to parse RPDB rule firewall mark, ignoring: %s", f);

        if (p) {
                r = safe_atou32(p, fwmask);
                if (r < 0)
                        return log_error_errno(r, "Failed to parse RPDB rule mask, ignoring: %s", f);
        }

        return 0;
}

int config_parse_routing_policy_rule_tos(
                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) {

        _cleanup_(routing_policy_rule_free_or_set_invalidp) RoutingPolicyRule *n = NULL;
        Network *network = userdata;
        int r;

        assert(filename);
        assert(section);
        assert(lvalue);
        assert(rvalue);
        assert(data);

        r = routing_policy_rule_new_static(network, filename, section_line, &n);
        if (r < 0)
                return r;

        r = safe_atou8(rvalue, &n->tos);
        if (r < 0) {
                log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse RPDB rule tos, ignoring: %s", rvalue);
                return 0;
        }

        n = NULL;

        return 0;
}

int config_parse_routing_policy_rule_priority(
                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) {

        _cleanup_(routing_policy_rule_free_or_set_invalidp) RoutingPolicyRule *n = NULL;
        Network *network = userdata;
        int r;

        assert(filename);
        assert(section);
        assert(lvalue);
        assert(rvalue);
        assert(data);

        r = routing_policy_rule_new_static(network, filename, section_line, &n);
        if (r < 0)
                return r;

        r = safe_atou32(rvalue, &n->priority);
        if (r < 0) {
                log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse RPDB rule priority, ignoring: %s", rvalue);
                return 0;
        }

        n = NULL;

        return 0;
}

int config_parse_routing_policy_rule_table(
                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) {

        _cleanup_(routing_policy_rule_free_or_set_invalidp) RoutingPolicyRule *n = NULL;
        Network *network = userdata;
        int r;

        assert(filename);
        assert(section);
        assert(lvalue);
        assert(rvalue);
        assert(data);

        r = routing_policy_rule_new_static(network, filename, section_line, &n);
        if (r < 0)
                return r;

        r = safe_atou32(rvalue, &n->table);
        if (r < 0) {
                log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse RPDB rule table, ignoring: %s", rvalue);
                return 0;
        }

        n = NULL;

        return 0;
}

int config_parse_routing_policy_rule_fwmark_mask(
                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) {

        _cleanup_(routing_policy_rule_free_or_set_invalidp) RoutingPolicyRule *n = NULL;
        Network *network = userdata;
        int r;

        assert(filename);
        assert(section);
        assert(lvalue);
        assert(rvalue);
        assert(data);

        r = routing_policy_rule_new_static(network, filename, section_line, &n);
        if (r < 0)
                return r;

        r = parse_fwmark_fwmask(rvalue, &n->fwmark, &n->fwmask);
        if (r < 0) {
                log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse RPDB rule firewall mark or mask, ignoring: %s", rvalue);
                return 0;
        }

        n = NULL;

        return 0;
}

int config_parse_routing_policy_rule_prefix(
                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) {

        _cleanup_(routing_policy_rule_free_or_set_invalidp) RoutingPolicyRule *n = NULL;
        Network *network = userdata;
        union in_addr_union *buffer;
        uint8_t *prefixlen;
        int r;

        assert(filename);
        assert(section);
        assert(lvalue);
        assert(rvalue);
        assert(data);

        r = routing_policy_rule_new_static(network, filename, section_line, &n);
        if (r < 0)
                return r;

        if (streq(lvalue, "To")) {
                buffer = &n->to;
                prefixlen = &n->to_prefixlen;
        } else {
                buffer = &n->from;
                prefixlen = &n->from_prefixlen;
        }

        if (n->family == AF_UNSPEC)
                r = in_addr_prefix_from_string_auto(rvalue, &n->family, buffer, prefixlen);
        else
                r = in_addr_prefix_from_string(rvalue, n->family, buffer, prefixlen);
        if (r < 0) {
                log_syntax(unit, LOG_ERR, filename, line, r, "RPDB rule prefix is invalid, ignoring assignment: %s", rvalue);
                return 0;
        }

        n = NULL;

        return 0;
}

int config_parse_routing_policy_rule_device(
                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) {

        _cleanup_(routing_policy_rule_free_or_set_invalidp) RoutingPolicyRule *n = NULL;
        Network *network = userdata;
        int r;

        assert(filename);
        assert(section);
        assert(lvalue);
        assert(rvalue);
        assert(data);

        r = routing_policy_rule_new_static(network, filename, section_line, &n);
        if (r < 0)
                return r;

        if (!ifname_valid(rvalue)) {
                log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse '%s' interface name, ignoring: %s", lvalue, rvalue);
                return 0;
        }

        if (streq(lvalue, "IncomingInterface")) {
                r = free_and_strdup(&n->iif, rvalue);
                if (r < 0)
                        return log_oom();
        } else {
                r = free_and_strdup(&n->oif, rvalue);
                if (r < 0)
                        return log_oom();
        }

        n = NULL;

        return 0;
}

int config_parse_routing_policy_rule_port_range(
                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) {
        _cleanup_(routing_policy_rule_free_or_set_invalidp) RoutingPolicyRule *n = NULL;
        Network *network = userdata;
        uint16_t low, high;
        int r;

        assert(filename);
        assert(section);
        assert(lvalue);
        assert(rvalue);
        assert(data);

        r = routing_policy_rule_new_static(network, filename, section_line, &n);
        if (r < 0)
                return r;

        r = parse_ip_port_range(rvalue, &low, &high);
        if (r < 0) {
                log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse routing policy rule port range '%s'", rvalue);
                return 0;
        }

        if (streq(lvalue, "SourcePort")) {
                n->sport.start = low;
                n->sport.end = high;
        } else {
                n->dport.start = low;
                n->dport.end = high;
        }

        n = NULL;

        return 0;
}

int config_parse_routing_policy_rule_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) {

        _cleanup_(routing_policy_rule_free_or_set_invalidp) RoutingPolicyRule *n = NULL;
        Network *network = userdata;
        int r;

        assert(filename);
        assert(section);
        assert(lvalue);
        assert(rvalue);
        assert(data);

        r = routing_policy_rule_new_static(network, filename, section_line, &n);
        if (r < 0)
                return r;

        r = parse_ip_protocol(rvalue);
        if (r < 0) {
                log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse IP protocol '%s' for routing policy rule, ignoring: %m", rvalue);
                return 0;
        }

        n->protocol = r;

        n = NULL;

        return 0;
}

int config_parse_routing_policy_rule_invert(
                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) {

        _cleanup_(routing_policy_rule_free_or_set_invalidp) RoutingPolicyRule *n = NULL;
        Network *network = userdata;
        int r;

        assert(filename);
        assert(section);
        assert(lvalue);
        assert(rvalue);
        assert(data);

        r = routing_policy_rule_new_static(network, filename, section_line, &n);
        if (r < 0)
                return r;

        r = parse_boolean(rvalue);
        if (r < 0) {
                log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse RPDB rule invert, ignoring: %s", rvalue);
                return 0;
        }

        n->invert_rule = r;

        n = NULL;

        return 0;
}

int config_parse_routing_policy_rule_family(
                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) {

        _cleanup_(routing_policy_rule_free_or_set_invalidp) RoutingPolicyRule *n = NULL;
        Network *network = userdata;
        AddressFamily a;
        int r;

        assert(filename);
        assert(section);
        assert(lvalue);
        assert(rvalue);
        assert(data);

        r = routing_policy_rule_new_static(network, filename, section_line, &n);
        if (r < 0)
                return r;

        a = routing_policy_rule_address_family_from_string(rvalue);
        if (a < 0) {
                log_syntax(unit, LOG_ERR, filename, line, 0,
                           "Invalid address family '%s', ignoring.", rvalue);
                return 0;
        }

        n->address_family = a;
        n = NULL;

        return 0;
}

static int routing_policy_rule_read_full_file(const char *state_file, char **ret) {
        _cleanup_free_ char *s = NULL;
        size_t size;
        int r;

        assert(state_file);

        r = read_full_file(state_file, &s, &size);
        if (r == -ENOENT)
                return -ENODATA;
        if (r < 0)
                return r;
        if (size <= 0)
                return -ENODATA;

        *ret = TAKE_PTR(s);

        return size;
}

int routing_policy_serialize_rules(Set *rules, FILE *f) {
        RoutingPolicyRule *rule = NULL;
        Iterator i;
        int r;

        assert(f);

        SET_FOREACH(rule, rules, i) {
                _cleanup_free_ char *from_str = NULL, *to_str = NULL;
                bool space = false;
                const char *family_str;

                fputs("RULE=", f);

                if (!in_addr_is_null(rule->family, &rule->from)) {
                        r = in_addr_to_string(rule->family, &rule->from, &from_str);
                        if (r < 0)
                                return r;

                        fprintf(f, "from=%s/%hhu",
                                from_str, rule->from_prefixlen);
                        space = true;
                }

                if (!in_addr_is_null(rule->family, &rule->to)) {
                        r = in_addr_to_string(rule->family, &rule->to, &to_str);
                        if (r < 0)
                                return r;

                        fprintf(f, "%sto=%s/%hhu",
                                space ? " " : "",
                                to_str, rule->to_prefixlen);
                        space = true;
                }

                family_str = af_to_name(rule->family);
                if (family_str)
                fprintf(f, "%sfamily=%s",
                        space ? " " : "",
                        family_str);

                if (rule->tos != 0) {
                        fprintf(f, "%stos=%hhu",
                                space ? " " : "",
                                rule->tos);
                        space = true;
                }

                fprintf(f, "%spriority=%"PRIu32,
                        space ? " " : "",
                        rule->priority);

                if (rule->fwmark != 0) {
                        fprintf(f, "%sfwmark=%"PRIu32"/%"PRIu32,
                                space ? " " : "",
                                rule->fwmark, rule->fwmask);
                        space = true;
                }

                if (rule->iif) {
                        fprintf(f, "%siif=%s",
                                space ? " " : "",
                                rule->iif);
                        space = true;
                }

                if (rule->oif) {
                        fprintf(f, "%soif=%s",
                                space ? " " : "",
                                rule->oif);
                        space = true;
                }

                if (rule->protocol != 0) {
                        fprintf(f, "%sprotocol=%hhu",
                                space ? " " : "",
                                rule->protocol);
                        space = true;
                }

                if (rule->sport.start != 0 || rule->sport.end != 0) {
                        fprintf(f, "%ssourcesport=%"PRIu16"-%"PRIu16,
                                space ? " " : "",
                                rule->sport.start, rule->sport.end);
                        space = true;
                }

                if (rule->dport.start != 0 || rule->dport.end != 0) {
                        fprintf(f, "%sdestinationport=%"PRIu16"-%"PRIu16,
                                space ? " " : "",
                                rule->dport.start, rule->dport.end);
                        space = true;
                }

                fprintf(f, "%stable=%"PRIu32 "\n",
                        space ? " " : "",
                        rule->table);
        }

        return 0;
}

int routing_policy_load_rules(const char *state_file, Set **rules) {
        _cleanup_strv_free_ char **l = NULL;
        _cleanup_free_ char *data = NULL;
        uint16_t low = 0, high = 0;
        const char *p;
        char **i;
        int r;

        assert(state_file);
        assert(rules);

        r = routing_policy_rule_read_full_file(state_file, &data);
        if (r <= 0)
                return r;

        l = strv_split_newlines(data);
        if (!l)
                return -ENOMEM;

        r = set_ensure_allocated(rules, &routing_policy_rule_hash_ops);
        if (r < 0)
                return r;

        STRV_FOREACH(i, l) {
                _cleanup_(routing_policy_rule_freep) RoutingPolicyRule *rule = NULL;

                p = startswith(*i, "RULE=");
                if (!p)
                        continue;

                r = routing_policy_rule_new(&rule);
                if (r < 0)
                        return r;

                for (;;) {
                        _cleanup_free_ char *word = NULL, *a = NULL, *b = NULL;

                        r = extract_first_word(&p, &word, NULL, 0);
                        if (r < 0)
                                return r;
                        if (r == 0)
                                break;

                        r = split_pair(word, "=", &a, &b);
                        if (r < 0)
                                continue;

                        if (STR_IN_SET(a, "from", "to")) {
                                union in_addr_union *buffer;
                                uint8_t *prefixlen;

                                if (streq(a, "to")) {
                                        buffer = &rule->to;
                                        prefixlen = &rule->to_prefixlen;
                                } else {
                                        buffer = &rule->from;
                                        prefixlen = &rule->from_prefixlen;
                                }

                                r = in_addr_prefix_from_string_auto(b, &rule->family, buffer, prefixlen);
                                if (r < 0) {
                                        log_error_errno(r, "RPDB rule prefix is invalid, ignoring assignment: %s", b);
                                        continue;
                                }

                        } else if (streq(a, "family")) {
                                r = af_from_name(b);
                                if (r < 0) {
                                        log_error_errno(r, "Failed to parse RPDB rule family, ignoring: %s", b);
                                        continue;
                                }
                                rule->family = r;
                        } else if (streq(a, "tos")) {
                                r = safe_atou8(b, &rule->tos);
                                if (r < 0) {
                                        log_error_errno(r, "Failed to parse RPDB rule tos, ignoring: %s", b);
                                        continue;
                                }
                        } else if (streq(a, "table")) {
                                r = safe_atou32(b, &rule->table);
                                if (r < 0) {
                                        log_error_errno(r, "Failed to parse RPDB rule table, ignoring: %s", b);
                                        continue;
                                }
                        } else if (streq(a, "priority")) {
                                r = safe_atou32(b, &rule->priority);
                                if (r < 0) {
                                        log_error_errno(r, "Failed to parse RPDB rule priority, ignoring: %s", b);
                                        continue;
                                }
                        } else if (streq(a, "fwmark")) {

                                r = parse_fwmark_fwmask(b, &rule->fwmark, &rule->fwmask);
                                if (r < 0) {
                                        log_error_errno(r, "Failed to parse RPDB rule firewall mark or mask, ignoring: %s", a);
                                        continue;
                                }
                        } else if (streq(a, "iif")) {

                                if (free_and_strdup(&rule->iif, b) < 0)
                                        return log_oom();

                        } else if (streq(a, "oif")) {

                                if (free_and_strdup(&rule->oif, b) < 0)
                                        return log_oom();
                        } else if (streq(a, "protocol")) {
                                r = safe_atou8(b, &rule->protocol);
                                if (r < 0) {
                                        log_error_errno(r, "Failed to parse RPDB rule protocol, ignoring: %s", b);
                                        continue;
                                }
                        } else if (streq(a, "sourceport")) {

                                r = parse_ip_port_range(b, &low, &high);
                                if (r < 0) {
                                        log_error_errno(r, "Invalid routing policy rule source port range, ignoring assignment:'%s'", b);
                                        continue;
                                }

                                rule->sport.start = low;
                                rule->sport.end = high;

                        } else if (streq(a, "destinationport")) {

                                r = parse_ip_port_range(b, &low, &high);
                                if (r < 0) {
                                        log_error_errno(r, "Invalid routing policy rule destination port range, ignoring assignment:'%s'", b);
                                        continue;
                                }

                                rule->dport.start = low;
                                rule->dport.end = high;
                        }
                }

                r = set_put(*rules, rule);
                if (r < 0) {
                        log_warning_errno(r, "Failed to add RPDB rule to saved DB, ignoring: %s", p);
                        continue;
                }
                if (r > 0)
                        rule = NULL;
        }

        return 0;
}

static bool manager_links_have_routing_policy_rule(Manager *m, RoutingPolicyRule *rule) {
        RoutingPolicyRule *link_rule;
        Iterator i;
        Link *link;

        assert(m);
        assert(rule);

        HASHMAP_FOREACH(link, m->links, i) {
                if (!link->network)
                        continue;

                LIST_FOREACH(rules, link_rule, link->network->rules)
                        if (routing_policy_rule_compare_func(link_rule, rule) == 0)
                                return true;
        }

        return false;
}

void routing_policy_rule_purge(Manager *m, Link *link) {
        RoutingPolicyRule *rule, *existing;
        Iterator i;
        int r;

        assert(m);
        assert(link);

        SET_FOREACH(rule, m->rules_saved, i) {
                existing = set_get(m->rules_foreign, rule);
                if (!existing)
                        continue; /* Saved rule does not exist anymore. */

                if (manager_links_have_routing_policy_rule(m, existing))
                        continue; /* Existing links have the saved rule. */

                /* Existing links do not have the saved rule. Let's drop the rule now, and re-configure it
                 * later when it is requested. */

                r = routing_policy_rule_remove(existing, link, NULL);
                if (r < 0) {
                        log_warning_errno(r, "Could not remove routing policy rules: %m");
                        continue;
                }

                link->routing_policy_rule_remove_messages++;

                assert_se(set_remove(m->rules_foreign, existing) == existing);
                routing_policy_rule_free(existing);
        }
}
