nexthop_encap.c

/* SPDX-License-Identifier: LGPL-2.1-only */
 
#include "nl-default.h"
 
#include <linux/lwtunnel.h>
 
#include "nl-route.h"
#include "nexthop-encap.h"
 
static const struct lwtunnel_encap_type {
        const char *name;
        const struct nh_encap_ops *ops;
} lwtunnel_encap_types[__LWTUNNEL_ENCAP_MAX] = {
        [LWTUNNEL_ENCAP_NONE] = { .name = "none" },
        [LWTUNNEL_ENCAP_MPLS] = { .name = "mpls", .ops = &mpls_encap_ops },
        [LWTUNNEL_ENCAP_IP] = { .name = "ip", .ops = &ip_encap_ops },
        [LWTUNNEL_ENCAP_IP6] = { .name = "ip6", .ops = &ip6_encap_ops },
        [LWTUNNEL_ENCAP_ILA] = { .name = "ila", .ops = &ila_encap_ops },
        [LWTUNNEL_ENCAP_BPF] = { .name = "bpf" },
};
 
static const char *nh_encap_type2str(unsigned int type)
{
        const char *name;
 
        if (type > LWTUNNEL_ENCAP_MAX)
                return "unknown";
 
        name = lwtunnel_encap_types[type].name;
 
        return name ? name : "unknown";
}
 
void nh_encap_dump(struct rtnl_nh_encap *rtnh_encap, struct nl_dump_params *dp)
{
        if (!rtnh_encap->ops)
                return;
 
        nl_dump(dp, " encap %s ",
                nh_encap_type2str(rtnh_encap->ops->encap_type));
 
        if (rtnh_encap->ops->dump)
                rtnh_encap->ops->dump(rtnh_encap->priv, dp);
}
 
int nh_encap_build_msg(struct nl_msg *msg, struct rtnl_nh_encap *rtnh_encap)
{
        struct nlattr *encap;
        int err;
 
        if (!rtnh_encap->ops || !rtnh_encap->ops->build_msg) {
                NL_DBG(2, "Nexthop encap type not implemented\n");
                return -NLE_INVAL;
        }
 
        NLA_PUT_U16(msg, RTA_ENCAP_TYPE, rtnh_encap->ops->encap_type);
 
        encap = nla_nest_start(msg, RTA_ENCAP);
        if (!encap)
                goto nla_put_failure;
 
        err = rtnh_encap->ops->build_msg(msg, rtnh_encap->priv);
        if (err < 0)
                return err;
 
        nla_nest_end(msg, encap);
 
        return 0;
 
nla_put_failure:
        return -NLE_MSGSIZE;
}
 
int nh_encap_parse_msg(struct nlattr *encap, struct nlattr *encap_type,
                       struct rtnl_nh_encap **encap_out)
{
        uint16_t e_type = nla_get_u16(encap_type);
 
        if (e_type == LWTUNNEL_ENCAP_NONE) {
                NL_DBG(2, "RTA_ENCAP_TYPE should not be LWTUNNEL_ENCAP_NONE\n");
 
                goto unsupported_encap;
        }
 
        if (e_type > LWTUNNEL_ENCAP_MAX) {
                NL_DBG(2, "Unknown RTA_ENCAP_TYPE: %d\n", e_type);
 
                goto unsupported_encap;
        }
 
        if (!lwtunnel_encap_types[e_type].ops) {
                NL_DBG(2, "RTA_ENCAP_TYPE %s is not implemented\n",
                       lwtunnel_encap_types[e_type].name);
 
                goto unsupported_encap;
        }
 
        return lwtunnel_encap_types[e_type].ops->parse_msg(encap, encap_out);
 
unsupported_encap:
        /* If we don't yet support this lwtunnel, just return 0.
         *
         * Force encap_out to NULL so that subsequent calls to set
         * it on a nexthop/route will simply reset the encapsulation
         * on that nexthop/route.
         */
        *encap_out = NULL;
        return 0;
}
 
int nh_encap_compare(struct rtnl_nh_encap *a, struct rtnl_nh_encap *b)
{
        if (!a && !b)
                return 0;
 
        if ((a && !b) || (!a && b) || (a->ops != b->ops))
                return 1;
 
        if (!a->ops || !a->ops->compare)
                return 0;
 
        return a->ops->compare(a->priv, b->priv);
}
 
void *nh_encap_check_and_get_priv(struct rtnl_nh_encap *nh_encap,
                                  uint16_t encap_type)
{
        if (!nh_encap || !nh_encap->ops ||
            nh_encap->ops->encap_type != encap_type) {
                return NULL;
        }
 
        return nh_encap->priv;
}