This patch sorts out an asymmetry in deletions. Currently, table and set
deletion commands come with an implicit content flush on deletion.
However, chain deletion results in -EBUSY if there is content in this
chain, so no implicit flush happens. So you have to send a flush command
in first place to delete chains, this is inconsistent and it can be
annoying in terms of user experience.
This patch uses the new NLM_F_NONREC flag to request non-recursive chain
deletion, ie. if the chain to be removed contains rules, then this
returns EBUSY. This problem was discussed during the NFWS'17 in Faro,
Portugal. In iptables, you hit -EBUSY if you try to delete a chain that
contains rules, so you have to flush first before you can remove
anything. Since iptables-compat uses the nf_tables netlink interface, it
has to use the NLM_F_NONREC flag from userspace to retain the original
iptables semantics, ie. bail out on removing chains that contain rules.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Bail out if user requests non-recursive deletion for tables and sets.
This new flags tells nf_tables netlink interface to reject deletions if
tables and sets have content.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nf_tables_newchain() is too large, wrap the chain update path in a
function to make it more maintainable.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds support for overloading stateful objects operations
through the select_ops() callback, just as it is implemented for
expressions.
This change is needed for upcoming additions to the stateful objects
infrastructure.
Signed-off-by: Pablo M. Bermudo Garay <pablombg@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Same conversion as for table names, use NFT_NAME_MAXLEN as upper
boundary as well.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Same conversion as for table names, use NFT_NAME_MAXLEN as upper
boundary as well.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Same conversion as for table names, use NFT_NAME_MAXLEN as upper
boundary as well.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Allocate all table names dynamically to allow for arbitrary lengths but
introduce NFT_NAME_MAXLEN as an upper sanity boundary. It's value was
chosen to allow using a domain name as per RFC 1035.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This is helpful for 'nft monitor' to track which process caused a given
change to the ruleset.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
These chain counters are only used by the iptables-compat tool, that
allow users to use the x_tables extensions from the existing nf_tables
framework. This patch makes nf_tables by ~5% for the general usecase,
ie. native nft users, where no chain counters are used at all.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pass down struct netlink_ext_ack as parameter to all of our nfnetlink
subsystem callbacks, so we can work on follow up patches to provide
finer grain error reporting using the new infrastructure that
2d4bc93368 ("netlink: extended ACK reporting") provides.
No functional change, just pass down this new object to callbacks.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The new fixed size hashtable backend implementation may result in a
large array of buckets that would spew splats from mm. Update this code
to fall back on vmalloc in case the memory allocation order is too
costly.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds the infrastructure to support several implementations of
the same set type. This selection will be based on the set description
and the features available for this set. This allow us to select set
backend implementation that will result in better performance numbers.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Andreas reports that the following incremental update using our commit
protocol doesn't work.
# nft -f incremental-update.nft
delete element ip filter client_to_any { 10.180.86.22 : goto CIn_1 }
delete chain ip filter CIn_1
... Error: Could not process rule: Device or resource busy
The existing code is not well-integrated into the commit phase protocol,
since element deletions do not result in refcount decrement from the
preparation phase. This results in bogus EBUSY errors like the one
above.
Two new functions come with this patch:
* nft_set_elem_activate() function is used from the abort path, to
restore the set element refcounting on objects that occurred from
the preparation phase.
* nft_set_elem_deactivate() that is called from nft_del_setelem() to
decrement set element refcounting on objects from the preparation
phase in the commit protocol.
The nft_data_uninit() has been renamed to nft_data_release() since this
function does not uninitialize any data store in the data register,
instead just releases the references to objects. Moreover, a new
function nft_data_hold() has been introduced to be used from
nft_set_elem_activate().
Reported-by: Andreas Schultz <aschultz@tpip.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When dumping the elements related to a specified set, we may invoke the
nf_tables_dump_set with the NFNL_SUBSYS_NFTABLES lock not acquired. So
we should use the proper rcu operation to avoid race condition, just
like other nft dump operations.
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
Netfilter/IPVS/OVS fixes for net
The following patchset contains a rather large batch of Netfilter, IPVS
and OVS fixes for your net tree. This includes fixes for ctnetlink, the
userspace conntrack helper infrastructure, conntrack OVS support,
ebtables DNAT target, several leaks in error path among other. More
specifically, they are:
1) Fix reference count leak in the CT target error path, from Gao Feng.
2) Remove conntrack entry clashing with a matching expectation, patch
from Jarno Rajahalme.
3) Fix bogus EEXIST when registering two different userspace helpers,
from Liping Zhang.
4) Don't leak dummy elements in the new bitmap set type in nf_tables,
from Liping Zhang.
5) Get rid of module autoload from conntrack update path in ctnetlink,
we don't need autoload at this late stage and it is happening with
rcu read lock held which is not good. From Liping Zhang.
6) Fix deadlock due to double-acquire of the expect_lock from conntrack
update path, this fixes a bug that was introduced when the central
spinlock got removed. Again from Liping Zhang.
7) Safe ct->status update from ctnetlink path, from Liping. The expect_lock
protection that was selected when the central spinlock was removed was
not really protecting anything at all.
8) Protect sequence adjustment under ct->lock.
9) Missing socket match with IPv6, from Peter Tirsek.
10) Adjust skb->pkt_type of DNAT'ed frames from ebtables, from
Linus Luessing.
11) Don't give up on evaluating the expression on new entries added via
dynset expression in nf_tables, from Liping Zhang.
12) Use skb_checksum() when mangling icmpv6 in IPv6 NAT as this deals
with non-linear skbuffs.
13) Don't allow IPv6 service in IPVS if no IPv6 support is available,
from Paolo Abeni.
14) Missing mutex release in error path of xt_find_table_lock(), from
Dan Carpenter.
15) Update maintainers files, Netfilter section. Add Florian to the
file, refer to nftables.org and change project status from Supported
to Maintained.
16) Bail out on mismatching extensions in element updates in nf_tables.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
If no NLM_F_EXCL is set and the element already exists in the set, make
sure that both elements have the same extensions.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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>
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>
This patch replace list_entry with list_prev_entry as it makes the
code more clear to read.
Signed-off-by: simran singhal <singhalsimran0@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add and use nfnl_msg_type() function to replace opencoded nfnetlink
message type. I suggested this change, Arushi Singhal made an initial
patch to address this but was missing several spots.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Conflicts:
drivers/net/ethernet/broadcom/genet/bcmmii.c
drivers/net/hyperv/netvsc.c
kernel/bpf/hashtab.c
Almost entirely overlapping changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
This reverts commit 1f48ff6c53.
This patch is not required anymore now that we keep a dummy list of
set elements in the bitmap set implementation, so revert this before
we forget this code has no clients.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
this is needed by the upcoming ct helper object type --
we'd like to be able use the table family (ip, ip6, inet) to figure
out which helper has to be requested.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This new function consolidates set lookup via either name or ID by
introducing a new nft_set_lookup() function. Replace existing spots
where we can use this too.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When we want to validate the expr's dependency or hooks, we must do two
things to accomplish it. First, write a X_validate callback function
and point ->validate to it. Second, call X_validate in init routine.
This is very common, such as fib, nat, reject expr and so on ...
It is a little ugly, since we will call X_validate in the expr's init
routine, it's better to do it in nf_tables_newexpr. So we can avoid to
do this again and again. After doing this, the second step listed above
is not useful anymore, remove them now.
Patch was tested by nftables/tests/py/nft-test.py and
nftables/tests/shell/run-tests.sh.
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The underlying nlmsg_multicast() already sets sk->sk_err for us to
notify socket overruns, so we should not do anything with this return
value. So we just call nfnetlink_set_err() if:
1) We fail to allocate the netlink message.
or
2) We don't have enough space in the netlink message to place attributes,
which means that we likely need to allocate a larger message.
Before this patch, the internal ESRCH netlink error code was propagated
to userspace, which is quite misleading. Netlink semantics mandate that
listeners just hit ENOBUFS if the socket buffer overruns.
Reported-by: Alexander Alemayhu <alexander@alemayhu.com>
Tested-by: Alexander Alemayhu <alexander@alemayhu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This new attribute allows us to uniquely identify a rule in transaction.
Robots may trigger an insertion followed by deletion in a batch, in that
scenario we still don't have a public rule handle that we can use to
delete the rule. This is similar to the NFTA_SET_ID attribute that
allows us to refer to an anonymous set from a batch.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch implements the check generation id as provided by nfnetlink.
This allows us to reject ruleset updates against stale baseline, so
userspace can retry update with a fresh ruleset cache.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The space notation allows us to classify the set backend implementation
based on the amount of required memory. This provides an order of the
set representation scalability in terms of memory. The size field is
still left in place so use this if the userspace provides no explicit
number of elements, so we cannot calculate the real memory that this set
needs. This also helps us break ties in the set backend selection
routine, eg. two backend implementations provide the same performance.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Use lookup as field name instead, to prepare the introduction of the
memory class in a follow up patch.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This provides context to walk callback iterator, thus, we know if the
walk happens from the set flush path. This is required by the new bitmap
set type coming in a follow up patch which has no real struct
nft_set_ext, so it has to allocate it based on the two bit compact
element representation.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Although semantics are similar to deactivate() with no implicit element
lookup, this is only called from the set flush path, so better rename
this to flush().
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
Netfilter updates for net-next
The following patchset contains Netfilter updates for your net-next
tree, they are:
1) Stash ctinfo 3-bit field into pointer to nf_conntrack object from
sk_buff so we only access one single cacheline in the conntrack
hotpath. Patchset from Florian Westphal.
2) Don't leak pointer to internal structures when exporting x_tables
ruleset back to userspace, from Willem DeBruijn. This includes new
helper functions to copy data to userspace such as xt_data_to_user()
as well as conversions of our ip_tables, ip6_tables and arp_tables
clients to use it. Not surprinsingly, ebtables requires an ad-hoc
update. There is also a new field in x_tables extensions to indicate
the amount of bytes that we copy to userspace.
3) Add nf_log_all_netns sysctl: This new knob allows you to enable
logging via nf_log infrastructure for all existing netnamespaces.
Given the effort to provide pernet syslog has been discontinued,
let's provide a way to restore logging using netfilter kernel logging
facilities in trusted environments. Patch from Michal Kubecek.
4) Validate SCTP checksum from conntrack helper, from Davide Caratti.
5) Merge UDPlite conntrack and NAT helpers into UDP, this was mostly
a copy&paste from the original helper, from Florian Westphal.
6) Reset netfilter state when duplicating packets, also from Florian.
7) Remove unnecessary check for broadcast in IPv6 in pkttype match and
nft_meta, from Liping Zhang.
8) Add missing code to deal with loopback packets from nft_meta when
used by the netdev family, also from Liping.
9) Several cleanups on nf_tables, one to remove unnecessary check from
the netlink control plane path to add table, set and stateful objects
and code consolidation when unregister chain hooks, from Gao Feng.
10) Fix harmless reference counter underflow in IPVS that, however,
results in problems with the introduction of the new refcount_t
type, from David Windsor.
11) Enable LIBCRC32C from nf_ct_sctp instead of nf_nat_sctp,
from Davide Caratti.
12) Missing documentation on nf_tables uapi header, from Liping Zhang.
13) Use rb_entry() helper in xt_connlimit, from Geliang Tang.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
If something fails in nf_tables_table_enable(), it unregisters the
chains. But the rollback code is the same as nf_tables_table_disable()
almostly, except there is one counter check. Now create one wrapper
function to eliminate the duplicated codes.
Signed-off-by: Feng <fgao@ikuai8.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add missing set->ndeact update on each deactivated element from the set
flush path. Otherwise, sets with fixed size break after flush since
accounting breaks.
# nft add set x y { type ipv4_addr\; size 2\; }
# nft add element x y { 1.1.1.1 }
# nft add element x y { 1.1.1.2 }
# nft flush set x y
# nft add element x y { 1.1.1.1 }
<cmdline>:1:1-28: Error: Could not process rule: Too many open files in system
Fixes: 8411b6442e ("netfilter: nf_tables: support for set flushing")
Reported-by: Elise Lennion <elise.lennion@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If the element exists and no NLM_F_EXCL is specified, do not bump
set->nelems, otherwise we leak one set element slot. This problem
amplifies if the set is full since the abort path always decrements the
counter for the -ENFILE case too, giving one spare extra slot.
Fix this by moving set->nelems update to nft_add_set_elem() after
successful element insertion. Moreover, remove the element if the set is
full so there is no need to rely on the abort path to undo things
anymore.
Fixes: c016c7e45d ("netfilter: nf_tables: honor NLM_F_EXCL flag in set element insertion")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Currently, if the user add a stateful object with the name size exceed
NFT_OBJ_MAXNAMELEN - 1 (i.e. 31), we truncate it down to 31 silently.
This is not friendly, furthermore, this will cause duplicated stateful
objects when the first 31 characters of the name is same. So limit the
stateful object's name size to NFT_OBJ_MAXNAMELEN - 1.
After apply this patch, error message will be printed out like this:
# name_32=$(printf "%0.sQ" {1..32})
# nft add counter filter $name_32
<cmdline>:1:1-52: Error: Could not process rule: Numerical result out
of range
add counter filter QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Also this patch cleans up the codes which missing the name size limit
validation in nftables.
Fixes: e50092404c ("netfilter: nf_tables: add stateful objects")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The return value of nf_tables_table_lookup() is valid pointer or one
pointer error. There are two cases:
1) IS_ERR(table) is true, it would return the error or reset the
table as NULL, it is unnecessary to perform the latter check
"table != NULL".
2) IS_ERR(obj) is false, the table is one valid pointer. It is also
unnecessary to perform that check.
The nf_tables_newset() and nf_tables_newobj() have same logic codes.
In summary, we could move the block of condition check "table != NULL"
in the else block to eliminate the original condition checks.
Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When dumping nft stateful objects, if NFTA_OBJ_TABLE and NFTA_OBJ_TYPE
attributes are not specified either, filter will become NULL, so oops
will happen(actually nft utility will always set NFTA_OBJ_TABLE attr,
so I write a test program to make this happen):
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: nf_tables_dump_obj+0x17c/0x330 [nf_tables]
[...]
Call Trace:
? nf_tables_dump_obj+0x5/0x330 [nf_tables]
? __kmalloc_reserve.isra.35+0x31/0x90
? __alloc_skb+0x5b/0x1e0
netlink_dump+0x124/0x2a0
__netlink_dump_start+0x161/0x190
nf_tables_getobj+0xe8/0x280 [nf_tables]
Fixes: a9fea2a3c3 ("netfilter: nf_tables: allow to filter stateful object dumps by type")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
BUG: KASAN: slab-out-of-bounds in nf_tables_rule_destroy+0xf1/0x130 at addr ffff88006a4c35c8
Read of size 8 by task nft/1607
When we've destroyed last valid expr, nft_expr_next() returns an invalid expr.
We must not dereference it unless it passes != nft_expr_last() check.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>