Hello, ---- On Fri, 13 Nov 2020 13:38:02 +0100 Hideaki Yoshifuji <hideaki.yoshif...@miraclelinux.com> wrote ----
> Hi, > > 2020年11月13日(金) 10:57 Dmytro Shytyi <dmy...@shytyi.net>: > > > > Variable SLAAC: SLAAC with prefixes of arbitrary length in PIO (randomly > > generated hostID or stable privacy + privacy extensions). > > The main problem is that SLAAC RA or PD allocates a /64 by the Wireless > > carrier 4G, 5G to a mobile hotspot, however segmentation of the /64 via > > SLAAC is required so that downstream interfaces can be further subnetted. > > Example: uCPE device (4G + WI-FI enabled) receives /64 via Wireless, and > > assigns /72 to VNF-Firewall, /72 to WIFI, /72 to VNF-Router, /72 to > > Load-Balancer and /72 to wired connected devices. > > IETF document that defines problem statement: > > draft-mishra-v6ops-variable-slaac-problem-stmt > > IETF document that specifies variable slaac: > > draft-mishra-6man-variable-slaac > > > > Signed-off-by: Dmytro Shytyi <dmy...@shytyi.net> > > --- > > diff -rupN net-next-5.10.0-rc2/net/ipv6/addrconf.c > > net-next-patch-5.10.0-rc2/net/ipv6/addrconf.c > > --- net-next-5.10.0-rc2/net/ipv6/addrconf.c 2020-11-10 > > 08:46:01.075193379 +0100 > > +++ net-next-patch-5.10.0-rc2/net/ipv6/addrconf.c 2020-11-13 > > 02:30:25.552724864 +0100 > > @@ -1315,10 +1322,14 @@ static int ipv6_create_tempaddr(struct i > > struct ifa6_config cfg; > > long max_desync_factor; > > struct in6_addr addr; > > - int ret = 0; > > + int ret; > > + struct in6_addr net_mask; > > + struct in6_addr temp; > > + struct in6_addr ipv6addr; > > + int i; > > > > write_lock_bh(&idev->lock); > > - > > + ret = 0; > > retry: > > in6_dev_hold(idev); > > if (idev->cnf.use_tempaddr <= 0) { > > @@ -1340,9 +1351,26 @@ retry: > > goto out; > > } > > in6_ifa_hold(ifp); > > - memcpy(addr.s6_addr, ifp->addr.s6_addr, 8); > > - ipv6_gen_rnd_iid(&addr); > > > > + if (ifp->prefix_len == 64) { > > + memcpy(addr.s6_addr, ifp->addr.s6_addr, 8); > > + ipv6_gen_rnd_iid(&addr); > > + } else if (ifp->prefix_len > 0 && ifp->prefix_len <= 128) { > > + memcpy(addr.s6_addr32, ifp->addr.s6_addr, 16); > > + get_random_bytes(temp.s6_addr32, 16); > > + > > + /* tranfrom prefix len into mask */ > > + ipv6_plen_to_mask(ifp->prefix_len, &net_mask); > > + > > + for (i = 0; i < 4; i++) { > > + /* network prefix */ > > + ipv6addr.s6_addr32[i] = addr.s6_addr32[i] & > > net_mask.s6_addr32[i]; > > + /* host id */ > > + ipv6addr.s6_addr32[i] |= temp.s6_addr32[i] & > > ~net_mask.s6_addr32[i]; > > + } > > + > > + memcpy(addr.s6_addr, ipv6addr.s6_addr32, 16); > > > > ipv6_addr_copy() and then ipv6_addr_prefix_copy() [Dmytro] Understood. Migrating to ipv6_addr_prefix_copy() > + } > > age = (now - ifp->tstamp) / HZ; > > > > regen_advance = idev->cnf.regen_max_retry * > > @@ -2576,9 +2604,57 @@ int addrconf_prefix_rcv_add_addr(struct > > u32 addr_flags, bool sllao, bool > > tokenized, > > __u32 valid_lft, u32 prefered_lft) > > { > > - struct inet6_ifaddr *ifp = ipv6_get_ifaddr(net, addr, dev, 1); > > + struct inet6_ifaddr *ifp = NULL; > > int create = 0; > > > > + if ((in6_dev->if_flags & IF_RA_VAR_PLEN) == IF_RA_VAR_PLEN && > > + in6_dev->cnf.addr_gen_mode != > > IN6_ADDR_GEN_MODE_STABLE_PRIVACY) { > > + struct inet6_ifaddr *result = NULL; > > + struct inet6_ifaddr *result_base = NULL; > > + struct in6_addr net_mask; > > + struct in6_addr net_prfx; > > + struct in6_addr curr_net_prfx; > > + bool prfxs_equal; > > + int i; > > + > > + result_base = result; > > + rcu_read_lock(); > > + list_for_each_entry_rcu(ifp, &in6_dev->addr_list, if_list) > > { > > + if (!net_eq(dev_net(ifp->idev->dev), net)) > > + continue; > > + > > + /* tranfrom prefix len into mask */ > > + ipv6_plen_to_mask(pinfo->prefix_len, &net_mask); > > + /* Prepare network prefixes */ > > + for (i = 0; i < 4; i++) { > > + /* Received/new network prefix */ > > + net_prfx.s6_addr32[i] = > > + pinfo->prefix.s6_addr32[i] & > > net_mask.s6_addr32[i]; > > + /* Configured/old IPv6 prefix */ > > + curr_net_prfx.s6_addr32[i] = > > + ifp->addr.s6_addr32[i] & > > net_mask.s6_addr32[i]; > > + } > > + /* Compare network prefixes */ > > + prfxs_equal = 1; > > + for (i = 0; i < 4; i++) { > > + if ((net_prfx.s6_addr32[i] ^ > > curr_net_prfx.s6_addr32[i]) != 0) > > + prfxs_equal = 0; > > + } > > ipv6_prefix_equal() [Dmytro] Understood. Migrating to ipv6_prefix_equal() > > > + if (prfxs_equal && pinfo->prefix_len == > > ifp->prefix_len) { > > + result = ifp; > > + in6_ifa_hold(ifp); > > + break; > > + } > > + } > > + rcu_read_unlock(); > > + if (result_base != result) > > + ifp = result; > > + else > > + ifp = NULL; > > + } else { > > + ifp = ipv6_get_ifaddr(net, addr, dev, 1); > > + } > > + > > if (!ifp && valid_lft) { > > int max_addresses = in6_dev->cnf.max_addresses; > > struct ifa6_config cfg = { > > @@ -2781,9 +2857,35 @@ void addrconf_prefix_rcv(struct net_devi > > dev_addr_generated = true; > > } > > goto ok; > > + goto put; > > + } else if (((in6_dev->if_flags & IF_RA_VAR_PLEN) == > > IF_RA_VAR_PLEN) && > > + pinfo->prefix_len > 0 && pinfo->prefix_len <= > > 128) { > > + /* SLAAC with prefixes of arbitrary length > > (Variable SLAAC). > > + * draft-mishra-6man-variable-slaac > > + * draft-mishra-v6ops-variable-slaac-problem-stmt > > + * Contact: Dmytro Shytyi. > > + */ > > + memcpy(&addr, &pinfo->prefix, 16); > > + if (in6_dev->cnf.addr_gen_mode == > > IN6_ADDR_GEN_MODE_STABLE_PRIVACY) { > > + if > > (!ipv6_generate_address_variable_plen(&addr, > > + > > 0, > > + > > in6_dev, > > + > > pinfo->prefix_len, > > + > > true)) { > > + addr_flags |= > > IFA_F_STABLE_PRIVACY; > > + goto ok; > > + } > > + } else if > > (!ipv6_generate_address_variable_plen(&addr, > > + 0, > > + > > in6_dev, > > + > > pinfo->prefix_len, > > + > > false)) { > > + goto ok; > > + } > > + } else { > > + net_dbg_ratelimited("IPv6: Prefix with unexpected > > length %d\n", > > + pinfo->prefix_len); > > } > > - net_dbg_ratelimited("IPv6 addrconf: prefix with wrong > > length %d\n", > > - pinfo->prefix_len); > > goto put; > > > > ok: > > @@ -3264,6 +3366,118 @@ retry: > > return 0; > > } > > > > +static void ipv6_plen_to_mask(int plen, struct in6_addr *net_mask) > > +{ > > + int i, plen_bytes; > > + char bit_array[7] = {0b10000000, > > + 0b11000000, > > + 0b11100000, > > + 0b11110000, > > + 0b11111000, > > + 0b11111100, > > + 0b11111110}; > > + > > + if (plen <= 0 || plen > 128) > > + pr_err("Unexpected plen: %d", plen); > > + > > + memset(net_mask, 0x00, sizeof(*net_mask)); > > + > > + /* We set all bits == 1 of s6_addr[i] */ > > + plen_bytes = plen / 8; > > + for (i = 0; i < plen_bytes; i++) > > + net_mask->s6_addr[i] = 0xff; > > + > > + /* We add bits from the bit_array to > > + * netmask starting from plen_bytes position > > + */ > > + if (plen % 8) > > + net_mask->s6_addr[plen_bytes] = bit_array[(plen % 8) - 1]; > > + memcpy(net_mask->s6_addr32, net_mask->s6_addr, 16); > > +} > > I don't think we need this function. [Dmytro] Indeed. > If needed, we could introduce ipv6_addr_host() (like ipv6_addr_prefix()) > in include/net/ipv6.h. [Dmytro] Maybe, we will see...