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2019-04-27netlink: make validation more configurable for future strictnessJohannes Berg1-2/+2
We currently have two levels of strict validation: 1) liberal (default) - undefined (type >= max) & NLA_UNSPEC attributes accepted - attribute length >= expected accepted - garbage at end of message accepted 2) strict (opt-in) - NLA_UNSPEC attributes accepted - attribute length >= expected accepted Split out parsing strictness into four different options: * TRAILING - check that there's no trailing data after parsing attributes (in message or nested) * MAXTYPE - reject attrs > max known type * UNSPEC - reject attributes with NLA_UNSPEC policy entries * STRICT_ATTRS - strictly validate attribute size The default for future things should be *everything*. The current *_strict() is a combination of TRAILING and MAXTYPE, and is renamed to _deprecated_strict(). The current regular parsing has none of this, and is renamed to *_parse_deprecated(). Additionally it allows us to selectively set one of the new flags even on old policies. Notably, the UNSPEC flag could be useful in this case, since it can be arranged (by filling in the policy) to not be an incompatible userspace ABI change, but would then going forward prevent forgetting attribute entries. Similar can apply to the POLICY flag. We end up with the following renames: * nla_parse -> nla_parse_deprecated * nla_parse_strict -> nla_parse_deprecated_strict * nlmsg_parse -> nlmsg_parse_deprecated * nlmsg_parse_strict -> nlmsg_parse_deprecated_strict * nla_parse_nested -> nla_parse_nested_deprecated * nla_validate_nested -> nla_validate_nested_deprecated Using spatch, of course: @@ expression TB, MAX, HEAD, LEN, POL, EXT; @@ -nla_parse(TB, MAX, HEAD, LEN, POL, EXT) +nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression TB, MAX, NLA, POL, EXT; @@ -nla_parse_nested(TB, MAX, NLA, POL, EXT) +nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT) @@ expression START, MAX, POL, EXT; @@ -nla_validate_nested(START, MAX, POL, EXT) +nla_validate_nested_deprecated(START, MAX, POL, EXT) @@ expression NLH, HDRLEN, MAX, POL, EXT; @@ -nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT) +nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT) For this patch, don't actually add the strict, non-renamed versions yet so that it breaks compile if I get it wrong. Also, while at it, make nla_validate and nla_parse go down to a common __nla_validate_parse() function to avoid code duplication. Ultimately, this allows us to have very strict validation for every new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the next patch, while existing things will continue to work as is. In effect then, this adds fully strict validation for any new command. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-27netlink: make nla_nest_start() add NLA_F_NESTED flagMichal Kubecek1-1/+1
Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most netlink based interfaces (including recently added ones) are still not setting it in kernel generated messages. Without the flag, message parsers not aware of attribute semantics (e.g. wireshark dissector or libmnl's mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display the structure of their contents. Unfortunately we cannot just add the flag everywhere as there may be userspace applications which check nlattr::nla_type directly rather than through a helper masking out the flags. Therefore the patch renames nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start() as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually are rewritten to use nla_nest_start(). Except for changes in include/net/netlink.h, the patch was generated using this semantic patch: @@ expression E1, E2; @@ -nla_nest_start(E1, E2) +nla_nest_start_noflag(E1, E2) @@ expression E1, E2; @@ -nla_nest_start_noflag(E1, E2 | NLA_F_NESTED) +nla_nest_start(E1, E2) Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Acked-by: Jiri Pirko <jiri@mellanox.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-01netfilter: conntrack: tcp: only close if RST matches exact sequenceFlorian Westphal1-10/+40
TCP resets cause instant transition from established to closed state provided the reset is in-window. Endpoints that implement RFC 5961 require resets to match the next expected sequence number. RST segments that are in-window (but that do not match RCV.NXT) are ignored, and a "challenge ACK" is sent back. Main problem for conntrack is that its a middlebox, i.e. whereas an end host might have ACK'd SEQ (and would thus accept an RST with this sequence number), conntrack might not have seen this ACK (yet). Therefore we can't simply flag RSTs with non-exact match as invalid. This updates RST processing as follows: 1. If the connection is in a state other than ESTABLISHED, nothing is changed, RST is subject to normal in-window check. 2. If the RSTs sequence number either matches exactly RCV.NXT, connection state moves to CLOSE. 3. The same applies if the RST sequence number aligns with a previous packet in the same direction. In all other cases, the connection remains in ESTABLISHED state. If the normal-in-window check passes, the timeout will be lowered to that of CLOSE. If the peer sends a challenge ack, connection timeout will be reset. If the challenge ACK triggers another RST (RST was valid after all), this 2nd RST will match expected sequence and conntrack state changes to CLOSE. If no challenge ACK is received, the connection will time out after CLOSE seconds (10 seconds by default), just like without this patch. Packetdrill test case: 0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 0.000 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 0.000 bind(3, ..., ...) = 0 0.000 listen(3, 1) = 0 0.100 < S 0:0(0) win 32792 <mss 1460,sackOK,nop,nop,nop,wscale 7> 0.100 > S. 0:0(0) ack 1 win 64240 <mss 1460,nop,nop,sackOK,nop,wscale 7> 0.200 < . 1:1(0) ack 1 win 257 0.200 accept(3, ..., ...) = 4 // Receive a segment. 0.210 < P. 1:1001(1000) ack 1 win 46 0.210 > . 1:1(0) ack 1001 // Application writes 1000 bytes. 0.250 write(4, ..., 1000) = 1000 0.250 > P. 1:1001(1000) ack 1001 // First reset, old sequence. Conntrack (correctly) considers this // invalid due to failed window validation (regardless of this patch). 0.260 < R 2:2(0) ack 1001 win 260 // 2nd reset, but too far ahead sequence. Same: correctly handled // as invalid. 0.270 < R 99990001:99990001(0) ack 1001 win 260 // in-window, but not exact sequence. // Current Linux kernels might reply with a challenge ack, and do not // remove connection. // Without this patch, conntrack state moves to CLOSE. // With patch, timeout is lowered like CLOSE, but connection stays // in ESTABLISHED state. 0.280 < R 1010:1010(0) ack 1001 win 260 // Expect challenge ACK 0.281 > . 1001:1001(0) ack 1001 win 501 // With or without this patch, RST will cause connection // to move to CLOSE (sequence number matches) // 0.282 < R 1001:1001(0) ack 1001 win 260 // ACK 0.300 < . 1001:1001(0) ack 1001 win 257 // more data could be exchanged here, connection // is still established // Client closes the connection. 0.610 < F. 1001:1001(0) ack 1001 win 260 0.650 > . 1001:1001(0) ack 1002 // Close the connection without reading outstanding data 0.700 close(4) = 0 // so one more reset. Will be deemed acceptable with patch as well: // connection is already closing. 0.701 > R. 1001:1001(0) ack 1002 win 501 // End packetdrill test case. With patch, this generates following conntrack events: [NEW] 120 SYN_SENT src=10.0.2.1 dst=10.0.0.1 sport=5437 dport=80 [UNREPLIED] [UPDATE] 60 SYN_RECV src=10.0.2.1 dst=10.0.0.1 sport=5437 dport=80 [UPDATE] 432000 ESTABLISHED src=10.0.2.1 dst=10.0.0.1 sport=5437 dport=80 [ASSURED] [UPDATE] 120 FIN_WAIT src=10.0.2.1 dst=10.0.0.1 sport=5437 dport=80 [ASSURED] [UPDATE] 60 CLOSE_WAIT src=10.0.2.1 dst=10.0.0.1 sport=5437 dport=80 [ASSURED] [UPDATE] 10 CLOSE src=10.0.2.1 dst=10.0.0.1 sport=5437 dport=80 [ASSURED] Without patch, first RST moves connection to close, whereas socket state does not change until FIN is received. [NEW] 120 SYN_SENT src=10.0.2.1 dst=10.0.0.1 sport=5141 dport=80 [UNREPLIED] [UPDATE] 60 SYN_RECV src=10.0.2.1 dst=10.0.0.1 sport=5141 dport=80 [UPDATE] 432000 ESTABLISHED src=10.0.2.1 dst=10.0.0.1 sport=5141 dport=80 [ASSURED] [UPDATE] 10 CLOSE src=10.0.2.1 dst=10.0.0.1 sport=5141 dport=80 [ASSURED] Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-01-18netfilter: conntrack: remove l4proto init and get_net callbacksFlorian Westphal1-24/+11
Those were needed we still had modular trackers. As we don't have those anymore, prefer direct calls and remove all the (un)register infrastructure associated with this. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-01-18netfilter: conntrack: unify sysctl handlingFlorian Westphal1-115/+1
Due to historical reasons, all l4 trackers register their own sysctls. This leads to copy&pasted boilerplate code, that does exactly same thing, just with different data structure. Place all of this in a single file. This allows to remove the various ctl_table pointers from the ct_netns structure and reduces overall code size. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-01-18netfilter: conntrack: handle builtin l4proto packet functions via direct callsFlorian Westphal1-6/+5
The l4 protocol trackers are invoked via indirect call: l4proto->packet(). With one exception (gre), all l4trackers are builtin, so we can make .packet optional and use a direct call for most protocols. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-11-03netfilter: conntrack: add nf_{tcp,udp,sctp,icmp,dccp,icmpv6,generic}_pernet()Pablo Neira Ayuso1-10/+5
Expose these functions to access conntrack protocol tracker netns area, nfnetlink_cttimeout needs this. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-10-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-nextDavid S. Miller1-147/+104
Pablo Neira Ayuso says: ==================== Netfilter updates for net-next The following patchset contains Netfilter updates for your net-next tree: 1) Support for matching on ipsec policy already set in the route, from Florian Westphal. 2) Split set destruction into deactivate and destroy phase to make it fit better into the transaction infrastructure, also from Florian. This includes a patch to warn on imbalance when setting the new activate and deactivate interfaces. 3) Release transaction list from the workqueue to remove expensive synchronize_rcu() from configuration plane path. This speeds up configuration plane quite a bit. From Florian Westphal. 4) Add new xfrm/ipsec extension, this new extension allows you to match for ipsec tunnel keys such as source and destination address, spi and reqid. From Máté Eckl and Florian Westphal. 5) Add secmark support, this includes connsecmark too, patches from Christian Gottsche. 6) Allow to specify remaining bytes in xt_quota, from Chenbo Feng. One follow up patch to calm a clang warning for this one, from Nathan Chancellor. 7) Flush conntrack entries based on layer 3 family, from Kristian Evensen. 8) New revision for cgroups2 to shrink the path field. 9) Get rid of obsolete need_conntrack(), as a result from recent demodularization works. 10) Use WARN_ON instead of BUG_ON, from Florian Westphal. 11) Unused exported symbol in nf_nat_ipv4_fn(), from Florian. 12) Remove superfluous check for timeout netlink parser and dump functions in layer 4 conntrack helpers. 13) Unnecessary redundant rcu read side locks in NAT redirect, from Taehee Yoo. 14) Pass nf_hook_state structure to error handlers, patch from Florian Westphal. 15) Remove ->new() interface from layer 4 protocol trackers. Place them in the ->packet() interface. From Florian. 16) Place conntrack ->error() handling in the ->packet() interface. Patches from Florian Westphal. 17) Remove unused parameter in the pernet initialization path, also from Florian. 18) Remove additional parameter to specify layer 3 protocol when looking up for protocol tracker. From Florian. 19) Shrink array of layer 4 protocol trackers, from Florian. 20) Check for linear skb only once from the ALG NAT mangling codebase, from Taehee Yoo. 21) Use rhashtable_walk_enter() instead of deprecated rhashtable_walk_init(), also from Taehee. 22) No need to flush all conntracks when only one single address is gone, from Tan Hu. 23) Remove redundant check for NAT flags in flowtable code, from Taehee Yoo. 24) Use rhashtable_lookup() instead of rhashtable_lookup_fast() from netfilter codebase, since rcu read lock side is already assumed in this path. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-20netfilter: conntrack: get rid of double sizeofzhong jiang1-2/+2
sizeof(sizeof()) is quite strange and does not seem to be what is wanted here. The issue is detected with the help of Coccinelle. Fixes: 39215846740a ("netfilter: conntrack: remove nlattr_size pointer from l4proto trackers") Signed-off-by: zhong jiang <zhongjiang@huawei.com> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-09-20netfilter: conntrack: remove l3->l4 mapping informationFlorian Westphal1-36/+1
l4 protocols are demuxed by l3num, l4num pair. However, almost all l4 trackers are l3 agnostic. Only exceptions are: - gre, icmp (ipv4 only) - icmpv6 (ipv6 only) This commit gets rid of the l3 mapping, l4 trackers can now be looked up by their IPPROTO_XXX value alone, which gets rid of the additional l3 indirection. For icmp, ipcmp6 and gre, add a check on state->pf and return -NF_ACCEPT in case we're asked to track e.g. icmpv6-in-ipv4, this seems more fitting than using the generic tracker. Additionally we can kill the 2nd l4proto definitions that were needed for v4/v6 split -- they are now the same so we can use single l4proto struct for each protocol, rather than two. The EXPORT_SYMBOLs can be removed as all these object files are part of nf_conntrack with no external references. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-09-20netfilter: conntrack: remove unused proto arg from netns init functionsFlorian Westphal1-1/+1
Its unused, next patch will remove l4proto->l3proto number to simplify l4 protocol demuxer lookup. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-09-20netfilter: conntrack: avoid using ->error callback if possibleFlorian Westphal1-20/+12
The error() handler gets called before allocating or looking up a connection tracking entry. We can instead use direct calls from the ->packet() handlers which get invoked for every packet anyway. Only exceptions are icmp and icmpv6, these two special cases will be handled in the next patch. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-09-20netfilter: conntrack: deconstify packet callback skb pointerFlorian Westphal1-1/+1
Only two protocols need the ->error() function: icmp and icmpv6. This is because icmp error mssages might be RELATED to an existing connection (e.g. PMTUD, port unreachable and the like), and their ->error() handlers do this. The error callback is already optional, so remove it for udp and call them from ->packet() instead. As the error() callback can call checksum functions that write to skb->csum*, the const qualifier has to be removed as well. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-09-20netfilter: conntrack: remove the l4proto->new() functionFlorian Westphal1-79/+77
->new() gets invoked after ->error() and before ->packet() if a conntrack lookup has found no result for the tuple. We can fold it into ->packet() -- the packet() implementations can check if the conntrack is confirmed (new) or not (already in hash). If its unconfirmed, the conntrack isn't in the hash yet so current skb created a new conntrack entry. Only relevant side effect -- if packet() doesn't return NF_ACCEPT but -NF_ACCEPT (or drop), while the conntrack was just created, then the newly allocated conntrack is freed right away, rather than not created in the first place. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-09-20netfilter: conntrack: pass nf_hook_state to packet and error handlersFlorian Westphal1-13/+15
nf_hook_state contains all the hook meta-information: netns, protocol family, hook location, and so on. Instead of only passing selected information, pass a pointer to entire structure. This will allow to merge the error and the packet handlers and remove the ->new() function in followup patches. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-09-11netfilter: conntrack: timeout interface depend on CONFIG_NF_CONNTRACK_TIMEOUTPablo Neira Ayuso1-6/+6
Now that cttimeout support for nft_ct is in place, these should depend on CONFIG_NF_CONNTRACK_TIMEOUT otherwise we can crash when dumping the policy if this option is not enabled. [ 71.600121] BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 [...] [ 71.600141] CPU: 3 PID: 7612 Comm: nft Not tainted 4.18.0+ #246 [...] [ 71.600188] Call Trace: [ 71.600201] ? nft_ct_timeout_obj_dump+0xc6/0xf0 [nft_ct] Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-08-29netfilter: conntrack: place 'new' timeout in first location tooFlorian Westphal1-0/+7
tcp, sctp and dccp trackers re-use the userspace ctnetlink states to index their timeout arrays, which means timeout[0] is never used. Copy the 'new' state (syn-sent, dccp-request, ..) to 0 as well so external users can simply read it off timeouts[0] without need to differentiate dccp/sctp/tcp and udp/icmp/gre/generic. The alternative is to map all array accesses to 'i - 1', but that is a much more intrusive change. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-07-16netfilter: conntrack: remove get_timeout() indirectionFlorian Westphal1-12/+11
Not needed, we can have the l4trackers fetch it themselvs. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-07-16netfilter: conntrack: avoid l4proto pkt_to_tuple callsFlorian Westphal1-19/+0
Handle common protocols (udp, tcp, ..), in the core and only do the call if needed by the l4proto tracker. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-07-16netfilter: conntrack: avoid calls to l4proto invert_tupleFlorian Westphal1-10/+0
Handle the common cases (tcp, udp, etc). in the core and only do the indirect call for the protocols that need it (GRE for instance). Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-27netfilter: Fix handling simultaneous open in TCP conntrackJozsef Kadlecsik1-0/+11
Dominique Martinet reported a TCP hang problem when simultaneous open was used. The problem is that the tcp_conntracks state table is not smart enough to handle the case. The state table could be fixed by introducing a new state, but that would require more lines of code compared to this patch, due to the required backward compatibility with ctnetlink. Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Reported-by: Dominique Martinet <asmadeus@codewreck.org> Tested-by: Dominique Martinet <asmadeus@codewreck.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-01-08netfilter: nf_conntrack: add IPS_OFFLOAD status bitPablo Neira Ayuso1-0/+3
This new bit tells us that the conntrack entry is owned by the flow table offload infrastructure. # cat /proc/net/nf_conntrack ipv4 2 tcp 6 src=10.141.10.2 dst=147.75.205.195 sport=36392 dport=443 src=147.75.205.195 dst=192.168.2.195 sport=443 dport=36392 [OFFLOAD] mark=0 zone=0 use=2 Note the [OFFLOAD] tag in the listing. The timer of such conntrack entries look like stopped from userspace. In practise, to make sure the conntrack entry does not go away, the conntrack timer is periodically set to an arbitrary large value that gets refreshed on every iteration from the garbage collector, so it never expires- and they display no internal state in the case of TCP flows. This allows us to save a bitcheck from the packet path via nf_ct_is_expired(). Conntrack entries that have been offloaded to the flow table infrastructure cannot be deleted/flushed via ctnetlink. The flow table infrastructure is also responsible for releasing this conntrack entry. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-01-08netfilter: conntrack: timeouts can be constFlorian Westphal1-1/+1
Nowadays this is just the default template that is used when setting up the net namespace, so nothing writes to these locations. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-01-08netfilter: conntrack: l4 protocol trackers can be constFlorian Westphal1-2/+2
previous patches removed all writes to these structs so we can now mark them as const. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-01-08netfilter: conntrack: remove nlattr_size pointer from l4proto trackersFlorian Westphal1-8/+8
similar to previous commit, but instead compute this at compile time and turn nlattr_size into an u16. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-11-20netfilter: conntrack: lower timeout to RETRANS seconds if window is 0Florian Westphal1-0/+3
When zero window is announced we can get into a situation where connection stays around forever: 1. One side announces zero window. 2. Other side closes. In this case, no FIN is sent (stuck in send queue). Unless other side opens the window up again conntrack stays in ESTABLISHED state for a very long time. Lets alleviate this by lowering the timeout to RETRANS (5 minutes), the other end should be sending zero window probes to keep the connection established as long as a socket still exists. Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-11-06netfilter: conntrack: don't cache nlattr_tuple_size result in nla_sizeFlorian Westphal1-2/+7
We currently call ->nlattr_tuple_size() once at register time and cache result in l4proto->nla_size. nla_size is the only member that is written to, avoiding this would allow to make l4proto trackers const. We can use ->nlattr_tuple_size() at run time, and cache result in the individual trackers instead. This is an intermediate step, next patch removes nlattr_size() callback and computes size at compile time, then removes nla_size. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-10-24netfilter: conntrack: remove pf argument from l4 packet functionsFlorian Westphal1-4/+2
not needed/used anymore. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-10-24netfilter: conntrack: add and use nf_ct_l4proto_log_invalidFlorian Westphal1-16/+9
We currently pass down the l4 protocol to the conntrack ->packet() function, but the only user of this is the debug info decision. Same information can be derived from struct nf_conn. Add a wrapper for the previous patch that extracs the information from nf_conn and passes it to nf_l4proto_log_invalid(). Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-10-24netfilter: conntrack: add and use nf_l4proto_log_invalidFlorian Westphal1-12/+10
We currently pass down the l4 protocol to the conntrack ->packet() function, but the only user of this is the debug info decision. Same information can be derived from struct nf_conn. As a first step, add and use a new log function for this, similar to nf_ct_helper_log(). Add __cold annotation -- invalid packets should be infrequent so gcc can consider all call paths that lead to such a function as unlikely. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-09-04netfilter: remove unused hooknum arg from packet functionsFlorian Westphal1-1/+0
tested with allmodconfig build. Signed-off-by: Florian Westphal <fw@strlen.de>
2017-08-24netfilter: conntrack: print_conntrack only needed if CONFIG_NF_CONNTRACK_PROCFSFlorian Westphal1-0/+6
Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-08-24netfilter: conntrack: place print_tuple in procfs partFlorian Westphal1-11/+0
CONFIG_NF_CONNTRACK_PROCFS is deprecated, no need to use a function pointer in the trackers for this. Place the printf formatting in the one place that uses it. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-08-24netfilter: conntrack: remove protocol name from l4proto structFlorian Westphal1-2/+0
no need to waste storage for something that is only needed in one place and can be deduced from protocol number. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-05-01Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-nextDavid S. Miller1-4/+21
Pablo Neira Ayuso says: ==================== Netfilter/IPVS updates for net-next The following patchset contains Netfilter updates for your net-next tree. A large bunch of code cleanups, simplify the conntrack extension codebase, get rid of the fake conntrack object, speed up netns by selective synchronize_net() calls. More specifically, they are: 1) Check for ct->status bit instead of using nfct_nat() from IPVS and Netfilter codebase, patch from Florian Westphal. 2) Use kcalloc() wherever possible in the IPVS code, from Varsha Rao. 3) Simplify FTP IPVS helper module registration path, from Arushi Singhal. 4) Introduce nft_is_base_chain() helper function. 5) Enforce expectation limit from userspace conntrack helper, from Gao Feng. 6) Add nf_ct_remove_expect() helper function, from Gao Feng. 7) NAT mangle helper function return boolean, from Gao Feng. 8) ctnetlink_alloc_expect() should only work for conntrack with helpers, from Gao Feng. 9) Add nfnl_msg_type() helper function to nfnetlink to build the netlink message type. 10) Get rid of unnecessary cast on void, from simran singhal. 11) Use seq_puts()/seq_putc() instead of seq_printf() where possible, also from simran singhal. 12) Use list_prev_entry() from nf_tables, from simran signhal. 13) Remove unnecessary & on pointer function in the Netfilter and IPVS code. 14) Remove obsolete comment on set of rules per CPU in ip6_tables, no longer true. From Arushi Singhal. 15) Remove duplicated nf_conntrack_l4proto_udplite4, from Gao Feng. 16) Remove unnecessary nested rcu_read_lock() in __nf_nat_decode_session(). Code running from hooks are already guaranteed to run under RCU read side. 17) Remove deadcode in nf_tables_getobj(), from Aaron Conole. 18) Remove double assignment in nf_ct_l4proto_pernet_unregister_one(), also from Aaron. 19) Get rid of unsed __ip_set_get_netlink(), from Aaron Conole. 20) Don't propagate NF_DROP error to userspace via ctnetlink in __nf_nat_alloc_null_binding() function, from Gao Feng. 21) Revisit nf_ct_deliver_cached_events() to remove unnecessary checks, from Gao Feng. 22) Kill the fake untracked conntrack objects, use ctinfo instead to annotate a conntrack object is untracked, from Florian Westphal. 23) Remove nf_ct_is_untracked(), now obsolete since we have no conntrack template anymore, from Florian. 24) Add event mask support to nft_ct, also from Florian. 25) Move nf_conn_help structure to include/net/netfilter/nf_conntrack_helper.h. 26) Add a fixed 32 bytes scratchpad area for conntrack helpers. Thus, we don't deal with variable conntrack extensions anymore. Make sure userspace conntrack helper doesn't go over that size. Remove variable size ct extension infrastructure now this code got no more clients. From Florian Westphal. 27) Restore offset and length of nf_ct_ext structure to 8 bytes now that wraparound is not possible any longer, also from Florian. 28) Allow to get rid of unassured flows under stress in conntrack, this applies to DCCP, SCTP and TCP protocols, from Florian. 29) Shrink size of nf_conntrack_ecache structure, from Florian. 30) Use TCP_MAX_WSCALE instead of hardcoded 14 in TCP tracker, from Gao Feng. 31) Register SYNPROXY hooks on demand, from Florian Westphal. 32) Use pernet hook whenever possible, instead of global hook registration, from Florian Westphal. 33) Pass hook structure to ebt_register_table() to consolidate some infrastructure code, from Florian Westphal. 34) Use consume_skb() and return NF_STOLEN, instead of NF_DROP in the SYNPROXY code, to make sure device stats are not fooled, patch from Gao Feng. 35) Remove NF_CT_EXT_F_PREALLOC this kills quite some code that we don't need anymore if we just select a fixed size instead of expensive runtime time calculation of this. From Florian. 36) Constify nf_ct_extend_register() and nf_ct_extend_unregister(), from Florian. 37) Simplify nf_ct_ext_add(), this kills nf_ct_ext_create(), from Florian. 38) Attach NAT extension on-demand from masquerade and pptp helper path, from Florian. 39) Get rid of useless ip_vs_set_state_timeout(), from Aaron Conole. 40) Speed up netns by selective calls of synchronize_net(), from Florian Westphal. 41) Silence stack size warning gcc in 32-bit arch in snmp helper, from Florian. 42) Inconditionally call nf_ct_ext_destroy(), even if we have no extensions, to deal with the NF_NAT_MANIP_SRC case. Patch from Liping Zhang. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-19netfilter: tcp: Use TCP_MAX_WSCALE instead of literal 14Gao Feng1-4/+3
The window scale may be enlarged from 14 to 15 according to the itef draft https://tools.ietf.org/html/draft-nishida-tcpm-maxwin-03. Use the macro TCP_MAX_WSCALE to support it easily with TCP stack in the future. Signed-off-by: Gao Feng <fgao@ikuai8.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-19netfilter: allow early drop of assured conntracksFlorian Westphal1-0/+18
If insertion of a new conntrack fails because the table is full, the kernel searches the next buckets of the hash slot where the new connection was supposed to be inserted at for an entry that hasn't seen traffic in reply direction (non-assured), if it finds one, that entry is is dropped and the new connection entry is allocated. Allow the conntrack gc worker to also remove *assured* conntracks if resources are low. Do this by querying the l4 tracker, e.g. tcp connections are now dropped if they are no longer established (e.g. in finwait). This could be refined further, e.g. by adding 'soft' established timeout (i.e., a timeout that is only used once we get close to resource exhaustion). Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-04-13netlink: pass extended ACK struct to parsing functionsJohannes Berg1-1/+2
Pass the new extended ACK reporting struct to all of the generic netlink parsing functions. For now, pass NULL in almost all callers (except for some in the core.) Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-02netfilter: conntrack: no need to pass ctinfo to error handlerFlorian Westphal1-1/+0
It is never accessed for reading and the only places that write to it are the icmp(6) handlers, which also set skb->nfct (and skb->nfctinfo). The conntrack core specifically checks for attached skb->nfct after ->error() invocation and returns early in this case. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-08-13netfilter: remove ip_conntrack* sysctl compat codePablo Neira Ayuso1-126/+1
This backward compatibility has been around for more than ten years, since Yasuyuki Kozakai introduced IPv6 in conntrack. These days, we have alternate /proc/net/nf_conntrack* entries, the ctnetlink interface and the conntrack utility got adopted by many people in the user community according to what I observed on the netfilter user mailing list. So let's get rid of this. Note that nf_conntrack_htable_size and unsigned int nf_conntrack_max do not need to be exported as symbol anymore. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-08-12netfilter: conntrack: Only need first 4 bytes to get l4proto portsGao Feng1-2/+2
We only need first 4 bytes instead of 8 bytes to get the ports of tcp/udp/dccp/sctp/udplite in their pkt_to_tuple function. Signed-off-by: Gao Feng <fgao@ikuai8.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-nextDavid S. Miller1-7/+1
Pablo Neira Ayuso says: ==================== Netfilter updates for net-next The following patchset contains Netfilter updates for your net-next tree, mostly from Florian Westphal to sort out the lack of sufficient validation in x_tables and connlabel preparation patches to add nf_tables support. They are: 1) Ensure we don't go over the ruleset blob boundaries in mark_source_chains(). 2) Validate that target jumps land on an existing xt_entry. This extra sanitization comes with a performance penalty when loading the ruleset. 3) Introduce xt_check_entry_offsets() and use it from {arp,ip,ip6}tables. 4) Get rid of the smallish check_entry() functions in {arp,ip,ip6}tables. 5) Make sure the minimal possible target size in x_tables. 6) Similar to #3, add xt_compat_check_entry_offsets() for compat code. 7) Check that standard target size is valid. 8) More sanitization to ensure that the target_offset field is correct. 9) Add xt_check_entry_match() to validate that matches are well-formed. 10-12) Three patch to reduce the number of parameters in translate_compat_table() for {arp,ip,ip6}tables by using a container structure. 13) No need to return value from xt_compat_match_from_user(), so make it void. 14) Consolidate translate_table() so it can be used by compat code too. 15) Remove obsolete check for compat code, so we keep consistent with what was already removed in the native layout code (back in 2007). 16) Get rid of target jump validation from mark_source_chains(), obsoleted by #2. 17) Introduce xt_copy_counters_from_user() to consolidate counter copying, and use it from {arp,ip,ip6}tables. 18,22) Get rid of unnecessary explicit inlining in ctnetlink for dump functions. 19) Move nf_connlabel_match() to xt_connlabel. 20) Skip event notification if connlabel did not change. 21) Update of nf_connlabels_get() to make the upcoming nft connlabel support easier. 23) Remove spinlock to read protocol state field in conntrack. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-19netfilter: conntrack: don't acquire lock during seq_printfFlorian Westphal1-7/+1
read access doesn't need any lock here. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-04-07netfilter: nf_conntrack_tcp: Fix stack out of bounds when parsing TCP optionsJozsef Kadlecsik1-0/+4
Baozeng Ding reported a KASAN stack out of bounds issue - it uncovered that the TCP option parsing routines in netfilter TCP connection tracking could read one byte out of the buffer of the TCP options. Therefore in the patch we check that the available data length is large enough to parse both TCP option code and size. Reported-by: Baozeng Ding <sploving1@gmail.com> Tested-by: Baozeng Ding <sploving1@gmail.com> Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-09-18netfilter: nf_conntrack: Add a struct net parameter to l4_pkt_to_tupleEric W. Biederman1-1/+1
As gre does not have the srckey in the packet gre_pkt_to_tuple needs to perform a lookup in it's per network namespace tables. Pass in the proper network namespace to all pkt_to_tuple implementations to ensure gre (and any similar protocols) can get this right. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-05-15conntrack: RFC5961 challenge ACK confuse conntrack LAST-ACK transitionJesper Dangaard Brouer1-3/+32
In compliance with RFC5961, the network stack send challenge ACK in response to spurious SYN packets, since commit 0c228e833c88 ("tcp: Restore RFC5961-compliant behavior for SYN packets"). This pose a problem for netfilter conntrack in state LAST_ACK, because this challenge ACK is (falsely) seen as ACKing last FIN, causing a false state transition (into TIME_WAIT). The challenge ACK is hard to distinguish from real last ACK. Thus, solution introduce a flag that tracks the potential for seeing a challenge ACK, in case a SYN packet is let through and current state is LAST_ACK. When conntrack transition LAST_ACK to TIME_WAIT happens, this flag is used for determining if we are expecting a challenge ACK. Scapy based reproducer script avail here: https://github.com/netoptimizer/network-testing/blob/master/scapy/tcp_hacks_3WHS_LAST_ACK.py Fixes: 0c228e833c88 ("tcp: Restore RFC5961-compliant behavior for SYN packets") Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-12-08Merge branch 'iov_iter' into for-nextAl Viro1-2/+2
2014-11-05netfilter: Convert print_tuple functions to return voidJoe Perches1-5/+5
Since adding a new function to seq_file (seq_has_overflowed()) there isn't any value for functions called from seq_show to return anything. Remove the int returns of the various print_tuple/<foo>_print_tuple functions. Link: http://lkml.kernel.org/p/f2e8cf8df433a197daa62cbaf124c900c708edc7.1412031505.git.joe@perches.com Cc: Pablo Neira Ayuso <pablo@netfilter.org> Cc: Patrick McHardy <kaber@trash.net> Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Cc: netfilter-devel@vger.kernel.org Cc: coreteam@netfilter.org Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-05netfilter: Remove return values for print_conntrack callbacksSteven Rostedt (Red Hat)1-2/+2
The seq_printf() and friends are having their return values removed. The print_conntrack() returns the result of seq_printf(), which is meaningless when seq_printf() returns void. Might as well remove the return values of print_conntrack() as well. Link: http://lkml.kernel.org/r/20141029220107.465008329@goodmis.org Acked-by: Pablo Neira Ayuso <pablo@netfilter.org> Cc: Patrick McHardy <kaber@trash.net> Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Cc: netfilter-devel@vger.kernel.org Cc: coreteam@netfilter.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-10-22netfilter: nf_conntrack: allow server to become a client in TW handlingMarcelo Leitner1-2/+2
When a port that was used to listen for inbound connections gets closed and reused for outgoing connections (like rsh ends up doing for stderr flow), current we may reject the SYN/ACK packet for the new connection because tcp_conntracks states forbirds a port to become a client while there is still a TIME_WAIT entry in there for it. As TCP may expire the TIME_WAIT socket in 60s and conntrack's timeout for it is 120s, there is a ~60s window that the application can end up opening a port that conntrack will end up blocking. This patch fixes this by simply allowing such state transition: if we see a SYN, in TIME_WAIT state, on REPLY direction, move it to sSS. Note that the rest of the code already handles this situation, more specificly in tcp_packet(), first switch clause. Signed-off-by: Marcelo Ricardo Leitner <mleitner@redhat.com> Acked-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>