diff options
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv6/addrconf.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 5b9de773ce73..594963a7e1ec 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -4398,6 +4398,59 @@ int ipv6_chk_home_addr(struct net *net, const struct in6_addr *addr) } #endif +/* RFC6554 has some algorithm to avoid loops in segment routing by + * checking if the segments contains any of a local interface address. + * + * Quote: + * + * To detect loops in the SRH, a router MUST determine if the SRH + * includes multiple addresses assigned to any interface on that router. + * If such addresses appear more than once and are separated by at least + * one address not assigned to that router. + */ +int ipv6_chk_rpl_srh_loop(struct net *net, const struct in6_addr *segs, + unsigned char nsegs) +{ + const struct in6_addr *addr; + int i, ret = 0, found = 0; + struct inet6_ifaddr *ifp; + bool separated = false; + unsigned int hash; + bool hash_found; + + rcu_read_lock(); + for (i = 0; i < nsegs; i++) { + addr = &segs[i]; + hash = inet6_addr_hash(net, addr); + + hash_found = false; + hlist_for_each_entry_rcu(ifp, &inet6_addr_lst[hash], addr_lst) { + if (!net_eq(dev_net(ifp->idev->dev), net)) + continue; + + if (ipv6_addr_equal(&ifp->addr, addr)) { + hash_found = true; + break; + } + } + + if (hash_found) { + if (found > 1 && separated) { + ret = 1; + break; + } + + separated = false; + found++; + } else { + separated = true; + } + } + rcu_read_unlock(); + + return ret; +} + /* * Periodic address status verification */ |