kernel/include/net/netns/ipv6.h, branch linux-5.2.y

ipv6: Add rate limit mask for ICMPv6 messages

2019-04-18T23:58:37Z

To make ICMPv6 closer to ICMPv4, add ratemask parameter. Since the ICMP message types use larger numeric values, a simple bitmask doesn't fit. I use large bitmap. The input and output are the in form of list of ranges. Set the default to rate limit all error messages but Packet Too Big. For Packet Too Big, use ratemask instead of hard-coded. There are functions where icmpv6_xrlim_allow() and icmpv6_global_allow() aren't called. This patch only adds them to icmpv6_echo_reply(). Rate limiting error messages is mandated by RFC 4443 but RFC 4890 says that it is also acceptable to rate limit informational messages. Thus, I removed the current hard-coded behavior of icmpv6_mask_allow() that doesn't rate limit informational messages. v2: Add dummy function proc_do_large_bitmap() if CONFIG_PROC_SYSCTL isn't defined, expand the description in ip-sysctl.txt and remove unnecessary conditional before kfree(). v3: Inline the bitmap instead of dynamically allocated. Still is a pointer to it is needed because of the way proc_do_large_bitmap work. Signed-off-by: Stephen Suryaputra Signed-off-by: David S. Miller

ipv6: Add icmp_echo_ignore_anycast for ICMPv6

2019-03-20T23:29:37Z

In addition to icmp_echo_ignore_multicast, there is a need to also prevent responding to pings to anycast addresses for security. Signed-off-by: Stephen Suryaputra Signed-off-by: David S. Miller

ipv6: Add icmp_echo_ignore_multicast support for ICMPv6

2019-03-19T21:29:51Z

IPv4 has icmp_echo_ignore_broadcast to prevent responding to broadcast pings. IPv6 needs a similar mechanism. v1->v2: - Remove NET_IPV6_ICMP_ECHO_IGNORE_MULTICAST. Signed-off-by: Stephen Suryaputra Signed-off-by: David S. Miller

ipv6: icmp: use percpu allocation

2019-02-25T05:57:26Z

Use percpu allocation for the ipv6.icmp_sk. Signed-off-by: Kefeng Wang Signed-off-by: David S. Miller

net/ipv6: Add knob to skip DELROUTE message on device down

2018-10-12T16:47:02Z

Another difference between IPv4 and IPv6 is the generation of RTM_DELROUTE notifications when a device is taken down (admin down) or deleted. IPv4 does not generate a message for routes evicted by the down or delete; IPv6 does. A NOS at scale really needs to avoid these messages and have IPv4 and IPv6 behave similarly, relying on userspace to handle link notifications and evict the routes. At this point existing user behavior needs to be preserved. Since notifications are a global action (not per app) the only way to preserve existing behavior and allow the messages to be skipped is to add a new sysctl (net/ipv6/route/skip_notify_on_dev_down) which can be set to disable the notificatioons. IPv6 route code already supports the option to skip the message (it is used for multipath routes for example). Besides the new sysctl we need to pass the skip_notify setting through the generic fib6_clean and fib6_walk functions to fib6_clean_node and to set skip_notify on calls to __ip_del_rt for the addrconf_ifdown path. Signed-off-by: David Ahern Signed-off-by: David S. Miller

ipv6: Add icmp_echo_ignore_all support for ICMPv6

2018-08-13T15:42:25Z

Preventing the kernel from responding to ICMP Echo Requests messages can be useful in several ways. The sysctl parameter 'icmp_echo_ignore_all' can be used to prevent the kernel from responding to IPv4 ICMP echo requests. For IPv6 pings, such a sysctl kernel parameter did not exist. Add the ability to prevent the kernel from responding to IPv6 ICMP echo requests through the use of the following sysctl parameter : /proc/sys/net/ipv6/icmp/echo_ignore_all. Update the documentation to reflect this change. Signed-off-by: Virgile Jarry Signed-off-by: David S. Miller

netfilter: ipv6: nf_defrag: reduce struct net memory waste

2018-06-18T12:13:25Z

It is a waste of memory to use a full "struct netns_sysctl_ipv6" while only one pointer is really used, considering netns_sysctl_ipv6 keeps growing. Also, since "struct netns_frags" has cache line alignment, it is better to move the frags_hdr pointer outside, otherwise we spend a full cache line for this pointer. This saves 192 bytes of memory per netns. Fixes: c038a767cd69 ("ipv6: add a new namespace for nf_conntrack_reasm") Signed-off-by: Eric Dumazet Signed-off-by: Pablo Neira Ayuso

ipv6: sr: Compute flowlabel for outer IPv6 header of seg6 encap mode

2018-04-25T17:02:15Z

ECMP (equal-cost multipath) hashes are typically computed on the packets' 5-tuple(src IP, dst IP, src port, dst port, L4 proto). For encapsulated packets, the L4 data is not readily available and ECMP hashing will often revert to (src IP, dst IP). This will lead to traffic polarization on a single ECMP path, causing congestion and waste of network capacity. In IPv6, the 20-bit flow label field is also used as part of the ECMP hash. In the lack of L4 data, the hashing will be on (src IP, dst IP, flow label). Having a non-zero flow label is thus important for proper traffic load balancing when L4 data is unavailable (i.e., when packets are encapsulated). Currently, the seg6_do_srh_encap() function extracts the original packet's flow label and set it as the outer IPv6 flow label. There are two issues with this behaviour: a) There is no guarantee that the inner flow label is set by the source. b) If the original packet is not IPv6, the flow label will be set to zero (e.g., IPv4 or L2 encap). This patch adds a function, named seg6_make_flowlabel(), that computes a flow label from a given skb. It supports IPv6, IPv4 and L2 payloads, and leverages the per namespace 'seg6_flowlabel" sysctl value. The currently support behaviours are as follows: -1 set flowlabel to zero. 0 copy flowlabel from Inner paceket in case of Inner IPv6 (Set flowlabel to 0 in case IPv4/L2) 1 Compute the flowlabel using seg6_make_flowlabel() This patch has been tested for IPv6, IPv4, and L2 traffic. Signed-off-by: Ahmed Abdelsalam Acked-by: David Lebrun 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: Add fib6_null_entry

2018-04-18T03:41:17Z

ip6_null_entry will stay a dst based return for lookups that fail to match an entry. Add a new fib6_null_entry which constitutes the root node and leafs for fibs. Replace existing references to ip6_null_entry with the new fib6_null_entry when dealing with FIBs. Signed-off-by: David Ahern Signed-off-by: David S. Miller