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2022-07-15ip: Fix data-races around sysctl_ip_default_ttl.Kuniyuki Iwashima1-2/+2
While reading sysctl_ip_default_ttl, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-05-13netfilter: conntrack: skip verification of zero UDP checksumKevin Mitchell1-3/+7
The checksum is optional for UDP packets. However nf_reject would previously require a valid checksum to elicit a response such as ICMP_DEST_UNREACH. Add some logic to nf_reject_verify_csum to determine if a UDP packet has a zero checksum and should therefore not be verified. Signed-off-by: Kevin Mitchell <kevmitch@arista.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-12-01netfilter: use actual socket sk for REJECT actionJan Engelhardt1-3/+3
True to the message of commit v5.10-rc1-105-g46d6c5ae953c, _do_ actually make use of state->sk when possible, such as in the REJECT modules. Reported-by: Minqiang Chen <ptpt52@gmail.com> Cc: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Jan Engelhardt <jengelh@inai.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-11-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-1/+1
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-01netfilter: nft_reject_inet: allow to use reject from inet ingressPablo Neira Ayuso1-2/+4
Enhance validation to support for reject from inet ingress chains. Note that, reject from inet ingress and netdev ingress differ. Reject packets from inet ingress are sent through ip_local_out() since inet reject emulates the IP layer receive path. So the reject packet follows to classic IP output and postrouting paths. The reject action from netdev ingress assumes the packet not yet entered the IP layer, so the reject packet is sent through dev_queue_xmit(). Therefore, reject packets from netdev ingress do not follow the classic IP output and postrouting paths. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-10-31netfilter: nf_reject: add reject skbuff creation helpersJose M. Guisado Gomez1-0/+122
Adds reject skbuff creation helper functions to ipv4/6 nf_reject infrastructure. Use these functions for reject verdict in bridge family. Can be reused by all different families that support reject and will not inject the reject packet through ip local out. Signed-off-by: Jose M. Guisado Gomez <guigom@riseup.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-10-30netfilter: use actual socket sk rather than skb sk when routing harderJason A. Donenfeld1-1/+1
If netfilter changes the packet mark when mangling, the packet is rerouted using the route_me_harder set of functions. Prior to this commit, there's one big difference between route_me_harder and the ordinary initial routing functions, described in the comment above __ip_queue_xmit(): /* Note: skb->sk can be different from sk, in case of tunnels */ int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl, That function goes on to correctly make use of sk->sk_bound_dev_if, rather than skb->sk->sk_bound_dev_if. And indeed the comment is true: a tunnel will receive a packet in ndo_start_xmit with an initial skb->sk. It will make some transformations to that packet, and then it will send the encapsulated packet out of a *new* socket. That new socket will basically always have a different sk_bound_dev_if (otherwise there'd be a routing loop). So for the purposes of routing the encapsulated packet, the routing information as it pertains to the socket should come from that socket's sk, rather than the packet's original skb->sk. For that reason __ip_queue_xmit() and related functions all do the right thing. One might argue that all tunnels should just call skb_orphan(skb) before transmitting the encapsulated packet into the new socket. But tunnels do *not* do this -- and this is wisely avoided in skb_scrub_packet() too -- because features like TSQ rely on skb->destructor() being called when that buffer space is truely available again. Calling skb_orphan(skb) too early would result in buffers filling up unnecessarily and accounting info being all wrong. Instead, additional routing must take into account the new sk, just as __ip_queue_xmit() notes. So, this commit addresses the problem by fishing the correct sk out of state->sk -- it's already set properly in the call to nf_hook() in __ip_local_out(), which receives the sk as part of its normal functionality. So we make sure to plumb state->sk through the various route_me_harder functions, and then make correct use of it following the example of __ip_queue_xmit(). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-06-30netfilter: introduce support for reject at prerouting stageLaura Garcia Liebana1-0/+21
REJECT statement can be only used in INPUT, FORWARD and OUTPUT chains. This patch adds support of REJECT, both icmp and tcp reset, at PREROUTING stage. The need for this patch comes from the requirement of some forwarding devices to reject traffic before the natting and routing decisions. The main use case is to be able to send a graceful termination to legitimate clients that, under any circumstances, the NATed endpoints are not available. This option allows clients to decide either to perform a reconnection or manage the error in their side, instead of just dropping the connection and let them die due to timeout. It is supported ipv4, ipv6 and inet families for nft infrastructure. Signed-off-by: Laura Garcia Liebana <nevola@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner1-4/+1
Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-13netfilter: reject: skip csum verification for protocols that don't support itAlin Nastac1-7/+2
Some protocols have other means to verify the payload integrity (AH, ESP, SCTP) while others are incompatible with nf_ip(6)_checksum implementation because checksum is either optional or might be partial (UDPLITE, DCCP, GRE). Because nf_ip(6)_checksum was used to validate the packets, ip(6)tables REJECT rules were not capable to generate ICMP(v6) errors for the protocols mentioned above. This commit also fixes the incorrect pseudo-header protocol used for IPv4 packets that carry other transport protocols than TCP or UDP (pseudo-header used protocol 0 iso the proper value). Signed-off-by: Alin Nastac <alin.nastac@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-12-19netfilter: avoid using skb->nf_bridge directlyFlorian Westphal1-2/+4
This pointer is going to be removed soon, so use the existing helpers in more places to avoid noise when the removal happens. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-01netfilter: nf_reject_ipv4: Fix use-after-free in send_resetTejaswi Tanikella1-0/+2
niph is not updated after pskb_expand_head changes the skb head. It still points to the freed data, which is then used to update tot_len and checksum. This could cause use-after-free poison crash. Update niph, if ip_route_me_harder does not fail. This only affects the interaction with REJECT targets and br_netfilter. Signed-off-by: Tejaswi Tanikella <tejaswit@codeaurora.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-06-16networking: make skb_put & friends return void pointersJohannes Berg1-1/+1
It seems like a historic accident that these return unsigned char *, and in many places that means casts are required, more often than not. Make these functions (skb_put, __skb_put and pskb_put) return void * and remove all the casts across the tree, adding a (u8 *) cast only where the unsigned char pointer was used directly, all done with the following spatch: @@ expression SKB, LEN; typedef u8; identifier fn = { skb_put, __skb_put }; @@ - *(fn(SKB, LEN)) + *(u8 *)fn(SKB, LEN) @@ expression E, SKB, LEN; identifier fn = { skb_put, __skb_put }; type T; @@ - E = ((T *)(fn(SKB, LEN))) + E = fn(SKB, LEN) which actually doesn't cover pskb_put since there are only three users overall. A handful of stragglers were converted manually, notably a macro in drivers/isdn/i4l/isdn_bsdcomp.c and, oddly enough, one of the many instances in net/bluetooth/hci_sock.c. In the former file, I also had to fix one whitespace problem spatch introduced. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-16networking: convert many more places to skb_put_zero()Johannes Berg1-2/+1
There were many places that my previous spatch didn't find, as pointed out by yuan linyu in various patches. The following spatch found many more and also removes the now unnecessary casts: @@ identifier p, p2; expression len; expression skb; type t, t2; @@ ( -p = skb_put(skb, len); +p = skb_put_zero(skb, len); | -p = (t)skb_put(skb, len); +p = skb_put_zero(skb, len); ) ... when != p ( p2 = (t2)p; -memset(p2, 0, len); | -memset(p, 0, len); ) @@ type t, t2; identifier p, p2; expression skb; @@ t *p; ... ( -p = skb_put(skb, sizeof(t)); +p = skb_put_zero(skb, sizeof(t)); | -p = (t *)skb_put(skb, sizeof(t)); +p = skb_put_zero(skb, sizeof(t)); ) ... when != p ( p2 = (t2)p; -memset(p2, 0, sizeof(*p)); | -memset(p, 0, sizeof(*p)); ) @@ expression skb, len; @@ -memset(skb_put(skb, len), 0, len); +skb_put_zero(skb, len); Apply it to the tree (with one manual fixup to keep the comment in vxlan.c, which spatch removed.) Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-19sk_buff: remove support for csum_bad in sk_buffDavide Caratti1-1/+1
This bit was introduced with commit 5a21232983aa ("net: Support for csum_bad in skbuff") to reduce the stack workload when processing RX packets carrying a wrong Internet Checksum. Up to now, only one driver and GRO core are setting it. Suggested-by: Tom Herbert <tom@herbertland.com> Signed-off-by: Davide Caratti <dcaratti@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-08netfilter: nf_reject: remove unused variableTaehee Yoo1-3/+0
variable oiph is not used. Signed-off-by: Taehee Yoo <ap420073@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-01-09netfilter: use fwmark_reflect in nf_send_resetPau Espin Pedrol1-0/+2
Otherwise, RST packets generated by ipt_REJECT always have mark 0 when the routing is checked later in the same code path. Fixes: e110861f8609 ("net: add a sysctl to reflect the fwmark on replies") Cc: Lorenzo Colitti <lorenzo@google.com> Signed-off-by: Pau Espin Pedrol <pau.espin@tessares.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-06-24netfilter: nf_reject_ipv4: don't send tcp RST if the packet is non-TCPLiping Zhang1-0/+3
In iptables, if the user add a rule to send tcp RST and specify the non-TCP protocol, such as UDP, kernel will reject this request. But in nftables, this validity check only occurs in nft tool, i.e. only in userspace. This means that user can add such a rule like follows via nfnetlink: "nft add rule filter forward ip protocol udp reject with tcp reset" This will generate some confusing tcp RST packets. So we should send tcp RST only when it is TCP packet. Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-11-23netfilter: remove duplicate includestephen hemminger1-1/+0
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-10-08ipv4, ipv6: Pass net into ip_local_out and ip6_local_outEric W. Biederman1-1/+1
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-08ipv4: Merge ip_local_out and ip_local_out_skEric W. Biederman1-1/+1
It is confusing and silly hiding a parameter so modify all of the callers to pass in the appropriate socket or skb->sk if no socket is known. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-29ipv4: Pass struct net into ip_route_me_harderEric W. Biederman1-1/+1
Don't make ip_route_me_harder guess which network namespace it is routing in, pass the network namespace in. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-09-29ipv4: Push struct net down into nf_send_resetEric W. Biederman1-1/+1
This is needed so struct net can be pushed down into ip_route_me_harder. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-04-08netfilter: bridge: add helpers for fetching physin/outdevFlorian Westphal1-1/+3
right now we store this in the nf_bridge_info struct, accessible via skb->nf_bridge. This patch prepares removal of this pointer from skb: Instead of using skb->nf_bridge->x, we use helpers to obtain the in/out device (or ifindexes). Followup patches to netfilter will then allow nf_bridge_info to be obtained by a call into the br_netfilter core, rather than keeping a pointer to it in sk_buff. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-03-10netfilter: fix sparse warnings in reject handlingFlorian Westphal1-1/+1
make C=1 CF=-D__CHECK_ENDIAN__ shows following: net/bridge/netfilter/nft_reject_bridge.c:65:50: warning: incorrect type in argument 3 (different base types) net/bridge/netfilter/nft_reject_bridge.c:65:50: expected restricted __be16 [usertype] protocol [..] net/bridge/netfilter/nft_reject_bridge.c:102:37: warning: cast from restricted __be16 net/bridge/netfilter/nft_reject_bridge.c:102:37: warning: incorrect type in argument 1 (different base types) [..] net/bridge/netfilter/nft_reject_bridge.c:121:50: warning: incorrect type in argument 3 (different base types) [..] net/bridge/netfilter/nft_reject_bridge.c:168:52: warning: incorrect type in argument 3 (different base types) [..] net/bridge/netfilter/nft_reject_bridge.c:233:52: warning: incorrect type in argument 3 (different base types) [..] Caused by two (harmless) errors: 1. htons() instead of ntohs() 2. __be16 for protocol in nf_reject_ipXhdr_put API, use u8 instead. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-03-03netfilter: reject: don't send icmp error if csum is invalidFlorian Westphal1-0/+23
tcp resets are never emitted if the packet that triggers the reject/reset has an invalid checksum. For icmp error responses there was no such check. It allows to distinguish icmp response generated via iptables -I INPUT -p udp --dport 42 -j REJECT and those emitted by network stack (won't respond if csum is invalid, REJECT does). Arguably its possible to avoid this by using conntrack and only using REJECT with -m conntrack NEW/RELATED. However, this doesn't work when connection tracking is not in use or when using nf_conntrack_checksum=0. Furthermore, sending errors in response to invalid csums doesn't make much sense so just add similar test as in nf_send_reset. Validate csum if needed and only send the response if it is ok. Reference: http://bugzilla.redhat.com/show_bug.cgi?id=1169829 Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-11-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-nextDavid S. Miller1-0/+1
Pablo Neira Ayuso says: ==================== netfilter/ipvs updates for net-next The following patchset contains Netfilter updates for your net-next tree, this includes the NAT redirection support for nf_tables, the cgroup support for nft meta and conntrack zone support for the connlimit match. Coming after those, a bunch of sparse warning fixes, missing netns bits and cleanups. More specifically, they are: 1) Prepare IPv4 and IPv6 NAT redirect code to use it from nf_tables, patches from Arturo Borrero. 2) Introduce the nf_tables redir expression, from Arturo Borrero. 3) Remove an unnecessary assignment in ip_vs_xmit/__ip_vs_get_out_rt(). Patch from Alex Gartrell. 4) Add nft_log_dereference() macro to the nf_log infrastructure, patch from Marcelo Leitner. 5) Add some extra validation when registering logger families, also from Marcelo. 6) Some spelling cleanups from stephen hemminger. 7) Fix sparse warning in nf_logger_find_get(). 8) Add cgroup support to nf_tables meta, patch from Ana Rey. 9) A Kconfig fix for the new redir expression and fix sparse warnings in the new redir expression. 10) Fix several sparse warnings in the netfilter tree, from Florian Westphal. 11) Reduce verbosity when OOM in nfnetlink_log. User can basically do nothing when this situation occurs. 12) Add conntrack zone support to xt_connlimit, again from Florian. 13) Add netnamespace support to the h323 conntrack helper, contributed by Vasily Averin. 14) Remove unnecessary nul-pointer checks before free_percpu() and module_put(), from Markus Elfring. 15) Use pr_fmt in nfnetlink_log, again patch from Marcelo Leitner. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-13netfilter: fix various sparse warningsFlorian Westphal1-0/+1
net/bridge/br_netfilter.c:870:6: symbol 'br_netfilter_enable' was not declared. Should it be static? no; add include net/ipv4/netfilter/nft_reject_ipv4.c:22:6: symbol 'nft_reject_ipv4_eval' was not declared. Should it be static? yes net/ipv6/netfilter/nf_reject_ipv6.c:16:6: symbol 'nf_send_reset6' was not declared. Should it be static? no; add include net/ipv6/netfilter/nft_reject_ipv6.c:22:6: symbol 'nft_reject_ipv6_eval' was not declared. Should it be static? yes net/netfilter/core.c:33:32: symbol 'nf_ipv6_ops' was not declared. Should it be static? no; add include net/netfilter/xt_DSCP.c:40:57: cast truncates bits from constant value (ffffff03 becomes 3) net/netfilter/xt_DSCP.c:57:59: cast truncates bits from constant value (ffffff03 becomes 3) add __force, 3 is what we want. net/ipv4/netfilter/nf_log_arp.c:77:6: symbol 'nf_log_arp_packet' was not declared. Should it be static? yes net/ipv4/netfilter/nf_reject_ipv4.c:17:6: symbol 'nf_send_reset' was not declared. Should it be static? no; add include Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-10-31netfilter: nf_reject_ipv4: split nf_send_reset() in smaller functionsPablo Neira Ayuso1-26/+62
That can be reused by the reject bridge expression to build the reject packet. The new functions are: * nf_reject_ip_tcphdr_get(): to sanitize and to obtain the TCP header. * nf_reject_iphdr_put(): to build the IPv4 header. * nf_reject_ip_tcphdr_put(): to build the TCP header. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-10-11netfilter: missing module license in the nf_reject_ipvX modulesPablo Neira Ayuso1-0/+3
[ 23.545204] nf_reject_ipv4: module license 'unspecified' taints kernel. Fixes: c8d7b98 ("netfilter: move nf_send_resetX() code to nf_reject_ipvX modules") Reported-by: Dave Young <dyoung@redhat.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-10-02netfilter: move nf_send_resetX() code to nf_reject_ipvX modulesPablo Neira Ayuso1-0/+127
Move nf_send_reset() and nf_send_reset6() to nf_reject_ipv4 and nf_reject_ipv6 respectively. This code is shared by x_tables and nf_tables. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>