nh_encap_mpls.c

/* SPDX-License-Identifier: LGPL-2.1-only */
 
#include <netlink-private/netlink.h>
#include <netlink-private/types.h>
#include <netlink-private/route/nexthop-encap.h>
#include <netlink/route/nexthop.h>
#include <linux/mpls_iptunnel.h>
#include <linux/lwtunnel.h>
 
struct mpls_iptunnel_encap {
        struct nl_addr *dst;
        uint8_t ttl;
};
 
static void mpls_encap_dump(void *priv, struct nl_dump_params *dp)
{
        struct mpls_iptunnel_encap *encap_info = priv;
        char buf[256];
 
        nl_dump(dp, "%s ", nl_addr2str(encap_info->dst, buf, sizeof(buf)));
 
        if (encap_info->ttl)
                nl_dump(dp, "ttl %u ", encap_info->ttl);
}
 
static int mpls_encap_build_msg(struct nl_msg *msg, void *priv)
{
        struct mpls_iptunnel_encap *encap_info = priv;
 
        NLA_PUT_ADDR(msg, MPLS_IPTUNNEL_DST, encap_info->dst);
        if (encap_info->ttl)
                NLA_PUT_U8(msg, MPLS_IPTUNNEL_TTL, encap_info->ttl);
 
        return 0;
 
nla_put_failure:
        return -NLE_MSGSIZE;
}
 
static void mpls_encap_destructor(void *priv)
{
        struct mpls_iptunnel_encap *encap_info = priv;
 
        nl_addr_put(encap_info->dst);
}
 
static struct nla_policy mpls_encap_policy[MPLS_IPTUNNEL_MAX + 1] = {
        [MPLS_IPTUNNEL_DST]     = { .type = NLA_U32 },
        [MPLS_IPTUNNEL_TTL]     = { .type = NLA_U8 },
};
 
static int mpls_encap_parse_msg(struct nlattr *nla, struct rtnl_nexthop *nh)
{
        struct nlattr *tb[MPLS_IPTUNNEL_MAX + 1];
        struct nl_addr *labels;
        uint8_t ttl = 0;
        int err;
 
        err = nla_parse_nested(tb, MPLS_IPTUNNEL_MAX, nla, mpls_encap_policy);
        if (err < 0)
                return err;
 
        if (!tb[MPLS_IPTUNNEL_DST])
                return -NLE_INVAL;
 
        labels = nl_addr_alloc_attr(tb[MPLS_IPTUNNEL_DST], AF_MPLS);
        if (!labels)
                return -NLE_NOMEM;
 
        if (tb[MPLS_IPTUNNEL_TTL])
                ttl = nla_get_u8(tb[MPLS_IPTUNNEL_TTL]);
 
        err = rtnl_route_nh_encap_mpls(nh, labels, ttl);
 
        nl_addr_put(labels);
 
        return err;
}
 
static int mpls_encap_compare(void *_a, void *_b)
{
        struct mpls_iptunnel_encap *a = _a;
        struct mpls_iptunnel_encap *b = _b;
        int diff = 0;
 
        diff |= (a->ttl != b->ttl);
        diff |= nl_addr_cmp(a->dst, b->dst);
 
        return diff;
}
 
struct nh_encap_ops mpls_encap_ops = {
        .encap_type     = LWTUNNEL_ENCAP_MPLS,
        .build_msg      = mpls_encap_build_msg,
        .parse_msg      = mpls_encap_parse_msg,
        .compare        = mpls_encap_compare,
        .dump           = mpls_encap_dump,
        .destructor     = mpls_encap_destructor,
};
 
int rtnl_route_nh_encap_mpls(struct rtnl_nexthop *nh,
                             struct nl_addr *addr,
                             uint8_t ttl)
{
        struct mpls_iptunnel_encap *mpls_encap;
        struct rtnl_nh_encap *rtnh_encap;
 
        if (!addr)
                return -NLE_INVAL;
 
        rtnh_encap = calloc(1, sizeof(*rtnh_encap));
        if (!rtnh_encap)
                return -NLE_NOMEM;
 
        mpls_encap = calloc(1, sizeof(*mpls_encap));
        if (!mpls_encap) {
                free(rtnh_encap);
                return -NLE_NOMEM;
        }
 
        mpls_encap->dst = nl_addr_get(addr);
        mpls_encap->ttl = ttl;
 
        rtnh_encap->priv = mpls_encap;
        rtnh_encap->ops = &mpls_encap_ops;
 
        nh_set_encap(nh, rtnh_encap);
 
        return 0;
}
 
struct nl_addr *rtnl_route_nh_get_encap_mpls_dst(struct rtnl_nexthop *nh)
{
        struct mpls_iptunnel_encap *mpls_encap;
 
        if (!nh->rtnh_encap || nh->rtnh_encap->ops->encap_type != LWTUNNEL_ENCAP_MPLS)
                return NULL;
 
        mpls_encap = (struct mpls_iptunnel_encap *)nh->rtnh_encap->priv;
        if (!mpls_encap)
                return NULL;
 
        return mpls_encap->dst;
}
 
uint8_t rtnl_route_nh_get_encap_mpls_ttl(struct rtnl_nexthop *nh)
{
        struct mpls_iptunnel_encap *mpls_encap;
 
        if (!nh->rtnh_encap || nh->rtnh_encap->ops->encap_type != LWTUNNEL_ENCAP_MPLS)
                return 0;
 
        mpls_encap = (struct mpls_iptunnel_encap *)nh->rtnh_encap->priv;
        if (!mpls_encap)
                return 0;
 
        return mpls_encap->ttl;
}