kernel/net/ipv6/ndisc.c, branch linux-5.1.y

ipv6/ndisc: Preserve IPv6 control buffer if protocol error handlers are called

2018-10-26T22:58:06Z

Commit a61bbcf28a8c ("[NET]: Store skb->timestamp as offset to a base timestamp") introduces a neighbour control buffer and zeroes it out in ndisc_rcv(), as ndisc_recv_ns() uses it. Commit f2776ff04722 ("[IPV6]: Fix address/interface handling in UDP and DCCP, according to the scoping architecture.") introduces the usage of the IPv6 control buffer in protocol error handlers (e.g. inet6_iif() in present-day __udp6_lib_err()). Now, with commit b94f1c0904da ("ipv6: Use icmpv6_notify() to propagate redirect, instead of rt6_redirect()."), we call protocol error handlers from ndisc_redirect_rcv(), after the control buffer is already stolen and some parts are already zeroed out. This implies that inet6_iif() on this path will always return zero. This gives unexpected results on UDP socket lookup in __udp6_lib_err(), as we might actually need to match sockets for a given interface. Instead of always claiming the control buffer in ndisc_rcv(), do that only when needed. Fixes: b94f1c0904da ("ipv6: Use icmpv6_notify() to propagate redirect, instead of rt6_redirect().") Signed-off-by: Stefano Brivio Reviewed-by: Sabrina Dubroca Signed-off-by: David S. Miller

net: Evict neighbor entries on carrier down

2018-10-12T16:47:39Z

When a link's carrier goes down it could be a sign of the port changing networks. If the new network has overlapping addresses with the old one, then the kernel will continue trying to use neighbor entries established based on the old network until the entries finally age out - meaning a potentially long delay with communications not working. This patch evicts neighbor entries on carrier down with the exception of those marked permanent. Permanent entries are managed by userspace (either an admin or a routing daemon such as FRR). Signed-off-by: David Ahern Signed-off-by: David S. Miller

net: remove 1 always zero parameter from ip6_redirect_no_header()

2018-10-02T23:12:40Z

(the parameter in question is mark) Signed-off-by: Maciej Żenczykowski Reviewed-by: David Ahern Signed-off-by: David S. Miller

ipv6: make DAD fail with enhanced DAD when nonce length differs

2018-07-16T20:45:16Z

Commit adc176c54722 ("ipv6 addrconf: Implemented enhanced DAD (RFC7527)") added enhanced DAD with a nonce length of 6 bytes. However, RFC7527 doesn't specify the length of the nonce, other than being 6 + 8*k bytes, with integer k >= 0 (RFC3971 5.3.2). The current implementation simply assumes that the nonce will always be 6 bytes, but others systems are free to choose different sizes. If another system sends a nonce of different length but with the same 6 bytes prefix, it shouldn't be considered as the same nonce. Thus, check that the length of the received nonce is the same as the length we sent. Ugly scapy test script running on veth0: def loop(): pkt=sniff(iface="veth0", filter="icmp6", count=1) pkt = pkt[0] b = bytearray(pkt[Raw].load) b[1] += 1 b += b'\xde\xad\xbe\xef\xde\xad\xbe\xef' pkt[Raw].load = bytes(b) pkt[IPv6].plen += 8 # fixup checksum after modifying the payload pkt[IPv6].payload.cksum -= 0x3b44 if pkt[IPv6].payload.cksum < 0: pkt[IPv6].payload.cksum += 0xffff sendp(pkt, iface="veth0") This should result in DAD failure for any address added to veth0's peer, but is currently ignored. Fixes: adc176c54722 ("ipv6 addrconf: Implemented enhanced DAD (RFC7527)") Signed-off-by: Sabrina Dubroca Reviewed-by: Stefano Brivio Signed-off-by: David S. Miller

vrf: check the original netdevice for generating redirect

2018-06-04T14:16:45Z

Use the right device to determine if redirect should be sent especially when using vrf. Same as well as when sending the redirect. Signed-off-by: Stephen Suryaputra Acked-by: David Ahern Signed-off-by: David S. Miller

net/ipv6: Rename fib6_info struct elements

2018-04-19T19:40:12Z

Change the prefix for fib6_info struct elements from rt6i_ to fib6_. rt6i_pcpu and rt6i_exception_bucket are left as is given that they point to rt6_info entries. Rename only; not functional change intended. Signed-off-by: David Ahern Signed-off-by: David S. Miller

net/ipv6: Flip FIB entries to fib6_info

2018-04-18T03:41:18Z

Convert all code paths referencing a FIB entry from rt6_info to fib6_info. Signed-off-by: David Ahern Signed-off-by: David S. Miller

net/ipv6: separate handling of FIB entries from dst based routes

2018-04-18T03:41:17Z

Last step before flipping the data type for FIB entries: - use fib6_info_alloc to create FIB entries in ip6_route_info_create and addrconf_dst_alloc - use fib6_info_release in place of dst_release, ip6_rt_put and rt6_release - remove the dst_hold before calling __ip6_ins_rt or ip6_del_rt - when purging routes, drop per-cpu routes - replace inc and dec of rt6i_ref with fib6_info_hold and fib6_info_release - use rt->from since it points to the FIB entry - drop references to exception bucket, fib6_metrics and per-cpu from dst entries (those are relevant for fib entries only) Signed-off-by: David Ahern Signed-off-by: David S. Miller

net/ipv6: Create a neigh_lookup for FIB entries

2018-04-18T03:41:17Z

The router discovery code has a FIB entry and wants to validate the gateway has a neighbor entry. Refactor the existing dst_neigh_lookup for IPv6 and create a new function that takes the gateway and device and returns a neighbor entry. Use the new function in ndisc_router_discovery to validate the gateway. Signed-off-by: David Ahern Signed-off-by: David S. Miller

net/ipv6: move expires into rt6_info

2018-04-18T03:41:17Z

Add expires to rt6_info for FIB entries, and add fib6 helpers to manage it. Data path use of dst.expires remains. The transition is fairly straightforward: when working with fib entries, rt->dst.expires is just rt->expires, rt6_clean_expires is replaced with fib6_clean_expires, rt6_set_expires becomes fib6_set_expires, and rt6_check_expired becomes fib6_check_expired, where the fib6 versions are added by this patch. Signed-off-by: David Ahern Signed-off-by: David S. Miller