kernel.git/net/openvswitch/conntrack.c, branch linux-4.18.y

openvswitch: Support conntrack zone limit

2018-05-25T20:45:19Z

Currently, nf_conntrack_max is used to limit the maximum number of conntrack entries in the conntrack table for every network namespace. For the VMs and containers that reside in the same namespace, they share the same conntrack table, and the total # of conntrack entries for all the VMs and containers are limited by nf_conntrack_max. In this case, if one of the VM/container abuses the usage the conntrack entries, it blocks the others from committing valid conntrack entries into the conntrack table. Even if we can possibly put the VM in different network namespace, the current nf_conntrack_max configuration is kind of rigid that we cannot limit different VM/container to have different # conntrack entries. To address the aforementioned issue, this patch proposes to have a fine-grained mechanism that could further limit the # of conntrack entries per-zone. For example, we can designate different zone to different VM, and set conntrack limit to each zone. By providing this isolation, a mis-behaved VM only consumes the conntrack entries in its own zone, and it will not influence other well-behaved VMs. Moreover, the users can set various conntrack limit to different zone based on their preference. The proposed implementation utilizes Netfilter's nf_conncount backend to count the number of connections in a particular zone. If the number of connection is above a configured limitation, ovs will return ENOMEM to the userspace. If userspace does not configure the zone limit, the limit defaults to zero that is no limitation, which is backward compatible to the behavior without this patch. The following high leve APIs are provided to the userspace: - OVS_CT_LIMIT_CMD_SET: * set default connection limit for all zones * set the connection limit for a particular zone - OVS_CT_LIMIT_CMD_DEL: * remove the connection limit for a particular zone - OVS_CT_LIMIT_CMD_GET: * get the default connection limit for all zones * get the connection limit for a particular zone Signed-off-by: Yi-Hung Wei Acked-by: Pravin B Shelar Signed-off-by: David S. Miller

netfilter: add NAT support for shifted portmap ranges

2018-04-24T08:29:12Z

This is a patch proposal to support shifted ranges in portmaps. (i.e. tcp/udp incoming port 5000-5100 on WAN redirected to LAN 192.168.1.5:2000-2100) Currently DNAT only works for single port or identical port ranges. (i.e. ports 5000-5100 on WAN interface redirected to a LAN host while original destination port is not altered) When different port ranges are configured, either 'random' mode should be used, or else all incoming connections are mapped onto the first port in the redirect range. (in described example WAN:5000-5100 will all be mapped to 192.168.1.5:2000) This patch introduces a new mode indicated by flag NF_NAT_RANGE_PROTO_OFFSET which uses a base port value to calculate an offset with the destination port present in the incoming stream. That offset is then applied as index within the redirect port range (index modulo rangewidth to handle range overflow). In described example the base port would be 5000. An incoming stream with destination port 5004 would result in an offset value 4 which means that the NAT'ed stream will be using destination port 2004. Other possibilities include deterministic mapping of larger or multiple ranges to a smaller range : WAN:5000-5999 -> LAN:5000-5099 (maps WAN port 5*xx to port 51xx) This patch does not change any current behavior. It just adds new NAT proto range functionality which must be selected via the specific flag when intended to use. A patch for iptables (libipt_DNAT.c + libip6t_DNAT.c) will also be proposed which makes this functionality immediately available. Signed-off-by: Thierry Du Tre Signed-off-by: Pablo Neira Ayuso

openvswitch: Remove padding from packet before L3+ conntrack processing

2018-02-01T14:46:22Z

IPv4 and IPv6 packets may arrive with lower-layer padding that is not included in the L3 length. For example, a short IPv4 packet may have up to 6 bytes of padding following the IP payload when received on an Ethernet device with a minimum packet length of 64 bytes. Higher-layer processing functions in netfilter (e.g. nf_ip_checksum(), and help() in nf_conntrack_ftp) assume skb->len reflects the length of the L3 header and payload, rather than referring back to ip_hdr->tot_len or ipv6_hdr->payload_len, and get confused by lower-layer padding. In the normal IPv4 receive path, ip_rcv() trims the packet to ip_hdr->tot_len before invoking netfilter hooks. In the IPv6 receive path, ip6_rcv() does the same using ipv6_hdr->payload_len. Similarly in the br_netfilter receive path, br_validate_ipv4() and br_validate_ipv6() trim the packet to the L3 length before invoking netfilter hooks. Currently in the OVS conntrack receive path, ovs_ct_execute() pulls the skb to the L3 header but does not trim it to the L3 length before calling nf_conntrack_in(NF_INET_PRE_ROUTING). When nf_conntrack_proto_tcp encounters a packet with lower-layer padding, nf_ip_checksum() fails causing a "nf_ct_tcp: bad TCP checksum" log message. While extra zero bytes don't affect the checksum, the length in the IP pseudoheader does. That length is based on skb->len, and without trimming, it doesn't match the length the sender used when computing the checksum. In ovs_ct_execute(), trim the skb to the L3 length before higher-layer processing. Signed-off-by: Ed Swierk Acked-by: Pravin B Shelar Signed-off-by: David S. Miller

openvswitch: drop unneeded newline

2018-01-02T18:49:53Z

OVS_NLERR prints a newline at the end of the message string, so the message string does not need to include a newline explicitly. Done using Coccinelle. Signed-off-by: Julia Lawall Signed-off-by: David S. Miller

openvswitch: conntrack: mark expected switch fall-through

2017-10-22T01:01:26Z

In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. Notice that in this particular case I placed a "fall through" comment on its own line, which is what GCC is expecting to find. Signed-off-by: Gustavo A. R. Silva Signed-off-by: David S. Miller

openvswitch: add ct_clear action

2017-10-10T23:38:34Z

This adds a ct_clear action for clearing conntrack state. ct_clear is currently implemented in OVS userspace, but is not backed by an action in the kernel datapath. This is useful for flows that may modify a packet tuple after a ct lookup has already occurred. Signed-off-by: Eric Garver Acked-by: Pravin B Shelar Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next

2017-09-04T00:08:42Z

Pablo Neira Ayuso says: ==================== Netfilter updates for net-next The following patchset contains Netfilter updates for your net-next tree. Basically, updates to the conntrack core, enhancements for nf_tables, conversion of netfilter hooks from linked list to array to improve memory locality and asorted improvements for the Netfilter codebase. More specifically, they are: 1) Add expection to hashes after timer initialization to prevent access from another CPU that walks on the hashes and calls del_timer(), from Florian Westphal. 2) Don't update nf_tables chain counters from hot path, this is only used by the x_tables compatibility layer. 3) Get rid of nested rcu_read_lock() calls from netfilter hook path. Hooks are always guaranteed to run from rcu read side, so remove nested rcu_read_lock() where possible. Patch from Taehee Yoo. 4) nf_tables new ruleset generation notifications include PID and name of the process that has updated the ruleset, from Phil Sutter. 5) Use skb_header_pointer() from nft_fib, so we can reuse this code from the nf_family netdev family. Patch from Pablo M. Bermudo. 6) Add support for nft_fib in nf_tables netdev family, also from Pablo. 7) Use deferrable workqueue for conntrack garbage collection, to reduce power consumption, from Patch from Subash Abhinov Kasiviswanathan. 8) Add nf_ct_expect_iterate_net() helper and use it. From Florian Westphal. 9) Call nf_ct_unconfirmed_destroy only from cttimeout, from Florian. 10) Drop references on conntrack removal path when skbuffs has escaped via nfqueue, from Florian. 11) Don't queue packets to nfqueue with dying conntrack, from Florian. 12) Constify nf_hook_ops structure, from Florian. 13) Remove neededlessly branch in nf_tables trace code, from Phil Sutter. 14) Add nla_strdup(), from Phil Sutter. 15) Rise nf_tables objects name size up to 255 chars, people want to use DNS names, so increase this according to what RFC 1035 specifies. Patch series from Phil Sutter. 16) Kill nf_conntrack_default_on, it's broken. Default on conntrack hook registration on demand, suggested by Eric Dumazet, patch from Florian. 17) Remove unused variables in compat_copy_entry_from_user both in ip_tables and arp_tables code. Patch from Taehee Yoo. 18) Constify struct nf_conntrack_l4proto, from Julia Lawall. 19) Constify nf_loginfo structure, also from Julia. 20) Use a single rb root in connlimit, from Taehee Yoo. 21) Remove unused netfilter_queue_init() prototype, from Taehee Yoo. 22) Use audit_log() instead of open-coding it, from Geliang Tang. 23) Allow to mangle tcp options via nft_exthdr, from Florian. 24) Allow to fetch TCP MSS from nft_rt, from Florian. This includes a fix for a miscalculation of the minimal length. 25) Simplify branch logic in h323 helper, from Nick Desaulniers. 26) Calculate netlink attribute size for conntrack tuple at compile time, from Florian. 27) Remove protocol name field from nf_conntrack_{l3,l4}proto structure. From Florian. 28) Remove holes in nf_conntrack_l4proto structure, so it becomes smaller. From Florian. 29) Get rid of print_tuple() indirection for /proc conntrack listing. Place all the code in net/netfilter/nf_conntrack_standalone.c. Patch from Florian. 30) Do not built in print_conntrack() if CONFIG_NF_CONNTRACK_PROCFS is off. From Florian. 31) Constify most nf_conntrack_{l3,l4}proto helper functions, from Florian. 32) Fix broken indentation in ebtables extensions, from Colin Ian King. 33) Fix several harmless sparse warning, from Florian. 34) Convert netfilter hook infrastructure to use array for better memory locality, joint work done by Florian and Aaron Conole. Moreover, add some instrumentation to debug this. 35) Batch nf_unregister_net_hooks() calls, to call synchronize_net once per batch, from Florian. 36) Get rid of noisy logging in ICMPv6 conntrack helper, from Florian. 37) Get rid of obsolete NFDEBUG() instrumentation, from Varsha Rao. 38) Remove unused code in the generic protocol tracker, from Davide Caratti. I think I will have material for a second Netfilter batch in my queue if time allow to make it fit in this merge window. ==================== Signed-off-by: David S. Miller

netfilter: conntrack: make protocol tracker pointers const

2017-08-24T16:52:33Z

Doesn't change generated code, but will make it easier to eventually make the actual trackers themselvers const. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

openvswitch: Remove unnecessary newlines from OVS_NLERR uses

2017-08-11T21:52:47Z

OVS_NLERR already adds a newline so these just add blank lines to the logging. Signed-off-by: Joe Perches Acked-by: Joe Stringer Signed-off-by: David S. Miller

openvswitch: fix potential out of bound access in parse_ct

2017-07-24T23:25:06Z

Before the 'type' is validated, we shouldn't use it to fetch the ovs_ct_attr_lens's minlen and maxlen, else, out of bound access may happen. Fixes: 7f8a436eaa2c ("openvswitch: Add conntrack action") Signed-off-by: Liping Zhang Acked-by: Pravin B Shelar Signed-off-by: David S. Miller