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d16fa75925
The variable err is being initialized with a value that is never read and it is being updated later with a new value. The initialization is redundant and can be removed. Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: David S. Miller <davem@davemloft.net>
383 lines
8.1 KiB
C
383 lines
8.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/**
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* Authors:
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* (C) 2020 Alexander Aring <alex.aring@gmail.com>
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*/
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#include <linux/rpl_iptunnel.h>
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#include <net/dst_cache.h>
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#include <net/ip6_route.h>
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#include <net/lwtunnel.h>
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#include <net/ipv6.h>
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#include <net/rpl.h>
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struct rpl_iptunnel_encap {
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struct ipv6_rpl_sr_hdr srh[0];
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};
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struct rpl_lwt {
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struct dst_cache cache;
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struct rpl_iptunnel_encap tuninfo;
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};
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static inline struct rpl_lwt *rpl_lwt_lwtunnel(struct lwtunnel_state *lwt)
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{
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return (struct rpl_lwt *)lwt->data;
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}
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static inline struct rpl_iptunnel_encap *
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rpl_encap_lwtunnel(struct lwtunnel_state *lwt)
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{
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return &rpl_lwt_lwtunnel(lwt)->tuninfo;
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}
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static const struct nla_policy rpl_iptunnel_policy[RPL_IPTUNNEL_MAX + 1] = {
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[RPL_IPTUNNEL_SRH] = { .type = NLA_BINARY },
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};
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static bool rpl_validate_srh(struct net *net, struct ipv6_rpl_sr_hdr *srh,
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size_t seglen)
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{
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int err;
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if ((srh->hdrlen << 3) != seglen)
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return false;
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/* check at least one segment and seglen fit with segments_left */
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if (!srh->segments_left ||
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(srh->segments_left * sizeof(struct in6_addr)) != seglen)
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return false;
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if (srh->cmpri || srh->cmpre)
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return false;
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err = ipv6_chk_rpl_srh_loop(net, srh->rpl_segaddr,
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srh->segments_left);
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if (err)
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return false;
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if (ipv6_addr_type(&srh->rpl_segaddr[srh->segments_left - 1]) &
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IPV6_ADDR_MULTICAST)
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return false;
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return true;
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}
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static int rpl_build_state(struct net *net, struct nlattr *nla,
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unsigned int family, const void *cfg,
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struct lwtunnel_state **ts,
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struct netlink_ext_ack *extack)
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{
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struct nlattr *tb[RPL_IPTUNNEL_MAX + 1];
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struct lwtunnel_state *newts;
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struct ipv6_rpl_sr_hdr *srh;
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struct rpl_lwt *rlwt;
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int err, srh_len;
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if (family != AF_INET6)
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return -EINVAL;
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err = nla_parse_nested(tb, RPL_IPTUNNEL_MAX, nla,
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rpl_iptunnel_policy, extack);
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if (err < 0)
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return err;
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if (!tb[RPL_IPTUNNEL_SRH])
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return -EINVAL;
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srh = nla_data(tb[RPL_IPTUNNEL_SRH]);
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srh_len = nla_len(tb[RPL_IPTUNNEL_SRH]);
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if (srh_len < sizeof(*srh))
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return -EINVAL;
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/* verify that SRH is consistent */
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if (!rpl_validate_srh(net, srh, srh_len - sizeof(*srh)))
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return -EINVAL;
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newts = lwtunnel_state_alloc(srh_len + sizeof(*rlwt));
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if (!newts)
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return -ENOMEM;
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rlwt = rpl_lwt_lwtunnel(newts);
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err = dst_cache_init(&rlwt->cache, GFP_ATOMIC);
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if (err) {
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kfree(newts);
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return err;
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}
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memcpy(&rlwt->tuninfo.srh, srh, srh_len);
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newts->type = LWTUNNEL_ENCAP_RPL;
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newts->flags |= LWTUNNEL_STATE_INPUT_REDIRECT;
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newts->flags |= LWTUNNEL_STATE_OUTPUT_REDIRECT;
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*ts = newts;
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return 0;
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}
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static void rpl_destroy_state(struct lwtunnel_state *lwt)
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{
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dst_cache_destroy(&rpl_lwt_lwtunnel(lwt)->cache);
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}
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static int rpl_do_srh_inline(struct sk_buff *skb, const struct rpl_lwt *rlwt,
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const struct ipv6_rpl_sr_hdr *srh)
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{
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struct ipv6_rpl_sr_hdr *isrh, *csrh;
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const struct ipv6hdr *oldhdr;
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struct ipv6hdr *hdr;
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unsigned char *buf;
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size_t hdrlen;
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int err;
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oldhdr = ipv6_hdr(skb);
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buf = kzalloc(ipv6_rpl_srh_alloc_size(srh->segments_left - 1) * 2,
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GFP_ATOMIC);
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if (!buf)
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return -ENOMEM;
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isrh = (struct ipv6_rpl_sr_hdr *)buf;
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csrh = (struct ipv6_rpl_sr_hdr *)(buf + ((srh->hdrlen + 1) << 3));
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memcpy(isrh, srh, sizeof(*isrh));
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memcpy(isrh->rpl_segaddr, &srh->rpl_segaddr[1],
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(srh->segments_left - 1) * 16);
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isrh->rpl_segaddr[srh->segments_left - 1] = oldhdr->daddr;
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ipv6_rpl_srh_compress(csrh, isrh, &srh->rpl_segaddr[0],
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isrh->segments_left - 1);
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hdrlen = ((csrh->hdrlen + 1) << 3);
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err = skb_cow_head(skb, hdrlen + skb->mac_len);
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if (unlikely(err)) {
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kfree(buf);
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return err;
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}
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skb_pull(skb, sizeof(struct ipv6hdr));
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skb_postpull_rcsum(skb, skb_network_header(skb),
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sizeof(struct ipv6hdr));
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skb_push(skb, sizeof(struct ipv6hdr) + hdrlen);
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skb_reset_network_header(skb);
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skb_mac_header_rebuild(skb);
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hdr = ipv6_hdr(skb);
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memmove(hdr, oldhdr, sizeof(*hdr));
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isrh = (void *)hdr + sizeof(*hdr);
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memcpy(isrh, csrh, hdrlen);
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isrh->nexthdr = hdr->nexthdr;
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hdr->nexthdr = NEXTHDR_ROUTING;
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hdr->daddr = srh->rpl_segaddr[0];
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ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
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skb_set_transport_header(skb, sizeof(struct ipv6hdr));
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skb_postpush_rcsum(skb, hdr, sizeof(struct ipv6hdr) + hdrlen);
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kfree(buf);
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return 0;
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}
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static int rpl_do_srh(struct sk_buff *skb, const struct rpl_lwt *rlwt)
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{
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struct dst_entry *dst = skb_dst(skb);
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struct rpl_iptunnel_encap *tinfo;
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int err = 0;
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if (skb->protocol != htons(ETH_P_IPV6))
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return -EINVAL;
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tinfo = rpl_encap_lwtunnel(dst->lwtstate);
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err = rpl_do_srh_inline(skb, rlwt, tinfo->srh);
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if (err)
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return err;
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return 0;
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}
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static int rpl_output(struct net *net, struct sock *sk, struct sk_buff *skb)
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{
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struct dst_entry *orig_dst = skb_dst(skb);
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struct dst_entry *dst = NULL;
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struct rpl_lwt *rlwt;
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int err;
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rlwt = rpl_lwt_lwtunnel(orig_dst->lwtstate);
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err = rpl_do_srh(skb, rlwt);
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if (unlikely(err))
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goto drop;
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preempt_disable();
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dst = dst_cache_get(&rlwt->cache);
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preempt_enable();
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if (unlikely(!dst)) {
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struct ipv6hdr *hdr = ipv6_hdr(skb);
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struct flowi6 fl6;
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memset(&fl6, 0, sizeof(fl6));
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fl6.daddr = hdr->daddr;
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fl6.saddr = hdr->saddr;
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fl6.flowlabel = ip6_flowinfo(hdr);
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fl6.flowi6_mark = skb->mark;
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fl6.flowi6_proto = hdr->nexthdr;
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dst = ip6_route_output(net, NULL, &fl6);
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if (dst->error) {
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err = dst->error;
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dst_release(dst);
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goto drop;
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}
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preempt_disable();
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dst_cache_set_ip6(&rlwt->cache, dst, &fl6.saddr);
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preempt_enable();
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}
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skb_dst_drop(skb);
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skb_dst_set(skb, dst);
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err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev));
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if (unlikely(err))
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goto drop;
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return dst_output(net, sk, skb);
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drop:
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kfree_skb(skb);
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return err;
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}
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static int rpl_input(struct sk_buff *skb)
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{
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struct dst_entry *orig_dst = skb_dst(skb);
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struct dst_entry *dst = NULL;
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struct rpl_lwt *rlwt;
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int err;
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rlwt = rpl_lwt_lwtunnel(orig_dst->lwtstate);
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err = rpl_do_srh(skb, rlwt);
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if (unlikely(err)) {
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kfree_skb(skb);
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return err;
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}
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preempt_disable();
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dst = dst_cache_get(&rlwt->cache);
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preempt_enable();
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skb_dst_drop(skb);
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if (!dst) {
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ip6_route_input(skb);
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dst = skb_dst(skb);
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if (!dst->error) {
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preempt_disable();
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dst_cache_set_ip6(&rlwt->cache, dst,
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&ipv6_hdr(skb)->saddr);
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preempt_enable();
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}
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} else {
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skb_dst_set(skb, dst);
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}
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err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev));
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if (unlikely(err))
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return err;
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return dst_input(skb);
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}
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static int nla_put_rpl_srh(struct sk_buff *skb, int attrtype,
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struct rpl_iptunnel_encap *tuninfo)
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{
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struct rpl_iptunnel_encap *data;
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struct nlattr *nla;
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int len;
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len = RPL_IPTUNNEL_SRH_SIZE(tuninfo->srh);
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nla = nla_reserve(skb, attrtype, len);
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if (!nla)
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return -EMSGSIZE;
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data = nla_data(nla);
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memcpy(data, tuninfo->srh, len);
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return 0;
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}
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static int rpl_fill_encap_info(struct sk_buff *skb,
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struct lwtunnel_state *lwtstate)
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{
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struct rpl_iptunnel_encap *tuninfo = rpl_encap_lwtunnel(lwtstate);
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if (nla_put_rpl_srh(skb, RPL_IPTUNNEL_SRH, tuninfo))
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return -EMSGSIZE;
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return 0;
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}
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static int rpl_encap_nlsize(struct lwtunnel_state *lwtstate)
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{
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struct rpl_iptunnel_encap *tuninfo = rpl_encap_lwtunnel(lwtstate);
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return nla_total_size(RPL_IPTUNNEL_SRH_SIZE(tuninfo->srh));
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}
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static int rpl_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b)
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{
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struct rpl_iptunnel_encap *a_hdr = rpl_encap_lwtunnel(a);
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struct rpl_iptunnel_encap *b_hdr = rpl_encap_lwtunnel(b);
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int len = RPL_IPTUNNEL_SRH_SIZE(a_hdr->srh);
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if (len != RPL_IPTUNNEL_SRH_SIZE(b_hdr->srh))
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return 1;
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return memcmp(a_hdr, b_hdr, len);
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}
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static const struct lwtunnel_encap_ops rpl_ops = {
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.build_state = rpl_build_state,
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.destroy_state = rpl_destroy_state,
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.output = rpl_output,
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.input = rpl_input,
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.fill_encap = rpl_fill_encap_info,
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.get_encap_size = rpl_encap_nlsize,
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.cmp_encap = rpl_encap_cmp,
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.owner = THIS_MODULE,
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};
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int __init rpl_init(void)
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{
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int err;
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err = lwtunnel_encap_add_ops(&rpl_ops, LWTUNNEL_ENCAP_RPL);
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if (err)
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goto out;
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pr_info("RPL Segment Routing with IPv6\n");
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return 0;
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out:
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return err;
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}
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void rpl_exit(void)
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{
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lwtunnel_encap_del_ops(&rpl_ops, LWTUNNEL_ENCAP_RPL);
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}
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