Acquiring of IPFW_WLOCK is requried for cases when we are going to
change some data that can be accessed during processing of packets flow.
When we create new named object, there are not yet any rules, that
references it, thus holding IPFW_UH_WLOCK is enough to safely update
needed structures. When we destroy an object, we do this only when its
reference counter becomes zero. And it is safe to not acquire IPFW_WLOCK,
because noone references it. The another case is when we failed to finish
some action and thus we are doing rollback and destroying an object, in
this case it is still not referenced by rules and no need to acquire
IPFW_WLOCK.
This also fixes panic with INVARIANTS due to recursive IPFW_WLOCK acquiring.
MFC after: 1 week
Sponsored by: Yandex LLC
This is an import of Alexander Bluhm's OpenBSD commit r1.60,
the first chunk had to be modified because on OpenBSD the
'cut' declaration is located elsewhere.
Upstream report by Jingmin Zhou:
https://marc.info/?l=openbsd-pf&m=150020133510896&w=2
OpenBSD commit message:
Use a 32 bit variable to detect integer overflow when searching for
an unused nat port. Prevents a possible endless loop if high port
is 65535 or low port is 0.
report and analysis Jingmin Zhou; OK sashan@ visa@
Quoted from: https://cvsweb.openbsd.org/cgi-bin/cvsweb/src/sys/net/pf_lb.c
PR: 221201
Submitted by: Fabian Keil <fk@fabiankeil.de>
Obtained from: OpenBSD via ElectroBSD
MFC after: 1 week
Previously, GRE packets in IPv6 tunnels would be dropped by IPFW (unless
net.inet6.ip6.fw.deny_unknown_exthdrs was unset).
PR: 220640
Submitted by: Kun Xie <kxie@xiplink.com>
MFC after: 1 week
pf_purge_thread() breaks up the work of iterating all states (in
pf_purge_expired_states()) and tracks progress in the idx variable.
If multiple vnets exist this results in pf_purge_thread() only calling
pf_purge_expired_states() for part of the states (the first part of the
first vnet, second part of the second vnet and so on).
Combined with the mark-and-sweep approach to cleaning up old rules (in
V_pf_unlinked_rules) that resulted in pf freeing rules that were still
referenced by states. This in turn caused panics when pf_state_expires()
encounters that state and attempts to access the rule.
We need to track the progress per vnet, not globally, so idx is moved
into a per-vnet V_pf_purge_idx.
PR: 219251
Sponsored by: Hackathon Essen 2017
(TS) method is used. When packet timestamp is used, the "current_qdelay"
keeps storing the last queue delay value calculated in the dequeue
function. Therefore, when a burst of packets arrives followed by
a pause, the "current_qdelay" will store a high value caused by the
burst and stick to that value during the pause because the queue
delay measurement is done inside the dequeue function. This causes
the drop probability calculation function to calculate high drop
probability value instead of zero and prevents the burst allowance
mechanism from working properly. Fix this problem by resetting
"current_qdelay" inside the drop probability calculation function
when the queue length is zero and TS option is used.
Submitted by: Rasool Al-Saadi <ralsaadi@swin.edu.au>
MFC after: 1 week
defined. On machines without arithmetic shift instructions, zero bits
may be shifted in from the left, giving a large positive result instead
of the desired divide-by power-of-2. Fix this by operating on the
absolute value and compensating for the possible negation later.
Reverse the order of the underflow/overflow tests and the exponential
decay calculation to avoid the possibility of an erroneous overflow
detection if p is a sufficiently small non-negative value. Also
check for negative values of prob before doing the exponential decay
to avoid another instance of of right shifting a negative value.
Tested by: Rasool Al-Saadi <ralsaadi@swin.edu.au>
MFC after: 1 week
When running the vnet init code (pf_load_vnet()) we used to iterate over
all vnets, marking them as unhooked.
This is incorrect and leads to panics if pf is unloaded, as the unload
code does not unregister the pfil hooks (because the vnet is marked as
unhooked).
There's no need or reason to touch other vnets during initialisation.
Their pf_load_vnet() function will be triggered, which handles all
required initialisation.
Reviewed by: zec, gnn
Differential Revision: https://reviews.freebsd.org/D10592
vnet_pf_uninit() is called through vnet_deregister_sysuninit() and
linker_file_unload() when the pf module is unloaded. This is executed
after pf_unload() so we end up trying to take locks which have been
destroyed already.
Move pf_unload() to a separate SYSUNINIT() to ensure it's called after
all the vnet_pf_uninit() calls.
Differential Revision: https://reviews.freebsd.org/D10025
When forwarding pf tracks the size of the largest fragment in a fragmented
packet, and refragments based on this size.
It failed to ensure that this size was a multiple of 8 (as is required for all
but the last fragment), so it could end up generating incorrect fragments.
For example, if we received an 8 byte and 12 byte fragment pf would emit a first
fragment with 12 bytes of payload and the final fragment would claim to be at
offset 8 (not 12).
We now assert that the fragment size is a multiple of 8 in ip6_fragment(), so
other users won't make the same mistake.
Reported by: Antonios Atlasis <aatlasis at secfu net>
MFC after: 3 days
The 'pktid' variable is modified while being used twice between
sequence points, probably due to htonl() is macro.
Reported by: PVS-Studio
MFC after: 1 week
to pass rule number and rule set to userland. In r272840 the kernel
internal rule representation was changed and the rulenum field of
struct ip_fw_rule got the type uint32_t, but userlevel representation
still have the type uint16_t. To not overflow the size of pointer
on the systems with 32-bit pointer size use separate variable to
copy rulenum and set.
Reported by: PVS-Studio
MFC after: 1 week
Some dummynet modules used strcpy() to copy from a larger buffer
(dn_aqm->name) to a smaller buffer (dn_extra_parms->name). It happens that
the lengths of the strings in the dn_aqm buffers were always hardcoded to be
smaller than the dn_extra_parms buffer ("CODEL", "PIE").
Use strlcpy() instead, to appease static checkers. No functional change.
Reported by: Coverity
CIDs: 1356163, 1356165
Sponsored by: Dell EMC Isilon
Make PFIL's lock global and use it for this purpose.
This reduces the number of locks needed to acquire for each packet.
Obtained from: Yandex LLC
MFC after: 2 weeks
Sponsored by: Yandex LLC
No objection from: #network
Differential Revision: https://reviews.freebsd.org/D10154
The module is designed for modification of a packets of any protocols.
For now it implements only TCP MSS modification. It adds the external
action handler for "tcp-setmss" action.
A rule with tcp-setmss action does additional check for protocol and
TCP flags. If SYN flag is present, it parses TCP options and modifies
MSS option if its value is greater than configured value in the rule.
Then it adjustes TCP checksum if needed. After handling the search
continues with the next rule.
Obtained from: Yandex LLC
MFC after: 2 weeks
Relnotes: yes
Sponsored by: Yandex LLC
No objection from: #network
Differential Revision: https://reviews.freebsd.org/D10150
This opcode can be used to attach some data to external action opcode.
And unlike to O_EXTERNAL_INSTANCE opcode, this opcode does not require
creating of named instance to pass configuration arguments to external
action handler. The data is coming just next to O_EXTERNAL_ACTION opcode.
The userlevel part currenly supports formatting for opcode with ipfw_insn
size, by default it expects u16 numeric value in the arg1.
Obtained from: Yandex LLC
MFC after: 2 weeks
Sponsored by: Yandex LLC
external action is completed, but the rule search is continued.
External action handler can change the content of @args argument,
that is used for dynamic state lookup. Enforce the new lookup to be able
install new state, when the search is continued.
Obtained from: Yandex LLC
MFC after: 1 week
Sponsored by: Yandex LLC
Prevent possible races in the pf_unload() / pf_purge_thread() shutdown
code. Lock the pf_purge_thread() with the new pf_end_lock to prevent
these races.
Use a shared/exclusive lock, as we need to also acquire another sx lock
(VNET_LIST_RLOCK). It's fine for both pf_purge_thread() and pf_unload()
to sleep,
Pointed out by: eri, glebius, jhb
Differential Revision: https://reviews.freebsd.org/D10026
In pf_route6() we re-run the ruleset with PF_FWD if the packet goes out
of a different interface. pf_test6() needs to know that the packet was
forwarded (in case it needs to refragment so it knows whether to call
ip6_output() or ip6_forward()).
This lead pf_test6() to try to evaluate rules against the PF_FWD
direction, which isn't supported, so it needs to treat PF_FWD as PF_OUT.
Once fwdir is set correctly the correct output/forward function will be
called.
PR: 217883
Submitted by: Kajetan Staszkiewicz
MFC after: 1 week
Sponsored by: InnoGames GmbH
- PIE_MAX_PROB is compared to variable of int64_t and the type promotion
rules can cause the value of that variable to be treated as unsigned.
If the value is actually negative, then the result of the comparsion
is incorrect, causing the algorithm to perform poorly in some
situations. Changing the constant to be signed cause the comparision
to work correctly.
- PIE_SCALE is also compared to signed values. Fortunately they are
also compared to zero and negative values are discarded so this is
more of a cosmetic fix.
- PIE_DQ_THRESHOLD is only compared to unsigned values, but it is small
enough that the automatic promotion to unsigned is harmless.
Submitted by: Rasool Al-Saadi <ralsaadi@swin.edu.au>
MFC after: 1 week
Rules are unlinked in shutdown_pf(), so we must call
pf_unload_vnet_purge(), which frees unlinked rules, after that, not
before.
Reviewed by: eri, bz
Differential Revision: https://reviews.freebsd.org/D10040
When we unload we don't hold the pf_rules_lock, so we cannot call rw_sleep()
with it, because it would release a lock we do not hold. There's no need for the
lock either, so we can just tsleep().
While here also make the same change in pf_purge_thread(), because it explicitly
takes the lock before rw_sleep() and then immediately releases it afterwards.
If the call to pf_state_key_clone() in pf_get_translation() fails (i.e. there's
no more memory for it) it frees skp. This is wrong, because skp is a
pf_state_key **, so we need to free *skp, as is done later in the function.
Getting it wrong means we try to free a stack variable of the calling
pf_test_rule() function, and we panic.
o check the size of O_IP_SRC_LOOKUP opcode, it can not exceed the size of
ipfw_insn_u32;
o rename ipfw_lookup_table_extended() function into ipfw_lookup_table() and
remove old ipfw_lookup_table();
o use args->f_id.flow_id6 that is in host byte order to get DSCP value;
o add SCTP ports support to 'lookup src/dst-port' opcode;
o add IPv6 support to 'lookup src/dst-ip' opcode.
PR: 217292
Reviewed by: melifaro
MFC after: 2 weeks
Sponsored by: Yandex LLC
Differential Revision: https://reviews.freebsd.org/D9873
When we doing reference counting of named objects in the new rule,
for existing objects check that opcode references to correct object,
otherwise return EINVAL.
PR: 217391
MFC after: 1 week
Sponsored by: Yandex LLC
in valuestate array.
When opcode has size equal to ipfw_insn_u32, this means that it should
additionally match value specified in d[0] with table entry value.
ipfw_table_lookup() returns table value index, use TARG_VAL() macro to
convert it to its value. The actual 32-bit value stored in the tag field
of table_value structure, where all unspecified u32 values are kept.
PR: 217262
Reviewed by: melifaro
MFC after: 1 week
Sponsored by: Yandex LLC
Consider the rule matching when both @done and @retval values
returned from ipfw_run_eaction() are zero. And modify ipfw_nptv6()
to return IP_FW_DENY and @done=0 when addresses do not match.
Obtained from: Yandex LLC
Sponsored by: Yandex LLC
inet_ntoa() cannot be used safely in a multithreaded environment
because it uses a static local buffer. Instead, use inet_ntoa_r()
with a buffer on the caller's stack.
Suggested by: glebius, emaste
Reviewed by: gnn
MFC after: 2 weeks
Sponsored by: Dell EMC
Differential Revision: https://reviews.freebsd.org/D9625
inet_ntoa() cannot be used safely in a multithreaded environment
because it uses a static local buffer. Instead, use inet_ntoa_r()
with a buffer on the caller's stack.
This code had an INET6 conditional before this commit, but opt_inet6.h
was not included, so INET6 was never defined. Apparently, pf's OS
fingerprinting hasn't worked with IPv6 for quite some time.
This commit might fix it, but I didn't test that.
Reviewed by: gnn, kp
MFC after: 2 weeks
Relnotes: yes (if I/someone can test pf OS fingerprinting with IPv6)
Sponsored by: Dell EMC
Differential Revision: https://reviews.freebsd.org/D9625
initialized, this can cause a divide by zero (if the VNET initialization
takes to long to complete).
Obtained from: pfSense
MFC after: 2 weeks
Sponsored by: Rubicon Communications, LLC (Netgate)
This lock was replaced from rwlock in r272840. But unlike rwlock, rmlock
doesn't allow recursion on rm_rlock(), so at this time fix this with
RM_RECURSE flag. Later we need to change ipfw to avoid such recursions.
PR: 216171
Reported by: Eugene Grosbein
MFC after: 1 week
