Turning on of this feature allows to keep dynamic states when parent
rule is deleted. But it works only when the default rule is
"allow from any to any".
Now when rule with dynamic opcode is going to be deleted, and
net.inet.ip.fw.dyn_keep_states is enabled, existing states will reference
named objects corresponding to this rule, and also reference the rule.
And when ipfw_dyn_lookup_state() will find state for deleted parent rule,
it will return the pointer to the deleted rule, that is still valid.
This implementation doesn't support O_LIMIT_PARENT rules.
The refcnt field was added to struct ip_fw to keep reference, also
next pointer added to be able iterate rules and not damage the content
when deleted rules are chained.
Named objects are referenced only when states are going to be deleted to
be able reuse kidx of named objects when new parent rules will be
installed.
ipfw_dyn_get_count() function was modified and now it also looks into
dynamic states and constructs maps of existing named objects. This is
needed to correctly export orphaned states into userland.
ipfw_free_rule() was changed to be global, since now dynamic state can
free rule, when it is expired and references counters becomes 1.
External actions subsystem also modified, since external actions can be
deregisterd and instances can be destroyed. In these cases deleted rules,
that are referenced by orphaned states, must be modified to prevent access
to freed memory. ipfw_dyn_reset_eaction(), ipfw_reset_eaction_instance()
functions added for these purposes.
Obtained from: Yandex LLC
MFC after: 2 months
Sponsored by: Yandex LLC
Differential Revision: https://reviews.freebsd.org/D17532
to switch the output method in run-time. Also document some sysctl
variables that can by changed for NAT64 module.
NAT64 had compile time option IPFIREWALL_NAT64_DIRECT_OUTPUT to use
if_output directly from nat64 module. By default is used netisr based
output method. Now both methods can be used, but they require different
handling by rules.
Obtained from: Yandex LLC
MFC after: 3 weeks
Sponsored by: Yandex LLC
Differential Revision: https://reviews.freebsd.org/D16647
o Modify ipfw(8) to be able set any prefix6 not just Well-Known,
and also show configured prefix6;
o relocate some definitions and macros into proper place;
o convert nat64_debug and nat64_allow_private variables to be
VNET-compatible;
o add struct nat64_config that keeps generic configuration needed
to NAT64 code;
o add nat64_check_prefix6() function to check validness of specified
by user IPv6 prefix according to RFC6052;
o use nat64_check_private_ip4() and nat64_embed_ip4() functions
instead of nat64_get_ip4() and nat64_set_ip4() macros. This allows
to use any configured IPv6 prefixes that are allowed by RFC6052;
o introduce NAT64_WKPFX flag, that is set when IPv6 prefix is
Well-Known IPv6 prefix. It is used to reduce overhead to check this;
o modify nat64lsn_cfg and nat64stl_cfg structures to use nat64_config
structure. And respectivelly modify the rest of code;
o remove now unused ro argument from nat64_output() function;
o remove __FreeBSD_version ifdef, NAT64 was not merged to older versions;
o add commented -DIPFIREWALL_NAT64_DIRECT_OUTPUT flag to module's Makefile
as example.
Obtained from: Yandex LLC
MFC after: 1 month
Sponsored by: Yandex LLC
given mbuf is considered as not matched.
If mbuf was consumed or freed during handling, we must return
IP_FW_DENY, since ipfw's pfil handler ipfw_check_packet() expects
IP_FW_DENY when mbuf pointer is NULL. This fixes KASSERT panics
when NAT64 is used with INVARIANTS. Also remove unused nomatch_final
field from struct nat64lsn_cfg.
Reported by: Justin Holcomb <justin at justinholcomb dot me>
Obtained from: Yandex LLC
MFC after: 1 week
Sponsored by: Yandex LLC
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
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
nat64_getlasthdr() returns an int, which can be -1 in case of error,
storing the result in an uint8_t and then comparing to < 0 is not
helpful. Do what is done in the rest of the code and make proto an
int here as well.
The module works together with ipfw(4) and implemented as its external
action module.
Stateless NAT64 registers external action with name nat64stl. This
keyword should be used to create NAT64 instance and to address this
instance in rules. Stateless NAT64 uses two lookup tables with mapped
IPv4->IPv6 and IPv6->IPv4 addresses to perform translation.
A configuration of instance should looks like this:
1. Create lookup tables:
# ipfw table T46 create type addr valtype ipv6
# ipfw table T64 create type addr valtype ipv4
2. Fill T46 and T64 tables.
3. Add rule to allow neighbor solicitation and advertisement:
# ipfw add allow icmp6 from any to any icmp6types 135,136
4. Create NAT64 instance:
# ipfw nat64stl NAT create table4 T46 table6 T64
5. Add rules that matches the traffic:
# ipfw add nat64stl NAT ip from any to table(T46)
# ipfw add nat64stl NAT ip from table(T64) to 64:ff9b::/96
6. Configure DNS64 for IPv6 clients and add route to 64:ff9b::/96
via NAT64 host.
Stateful NAT64 registers external action with name nat64lsn. The only
one option required to create nat64lsn instance - prefix4. It defines
the pool of IPv4 addresses used for translation.
A configuration of instance should looks like this:
1. Add rule to allow neighbor solicitation and advertisement:
# ipfw add allow icmp6 from any to any icmp6types 135,136
2. Create NAT64 instance:
# ipfw nat64lsn NAT create prefix4 A.B.C.D/28
3. Add rules that matches the traffic:
# ipfw add nat64lsn NAT ip from any to A.B.C.D/28
# ipfw add nat64lsn NAT ip6 from any to 64:ff9b::/96
4. Configure DNS64 for IPv6 clients and add route to 64:ff9b::/96
via NAT64 host.
Obtained from: Yandex LLC
Relnotes: yes
Sponsored by: Yandex LLC
Differential Revision: https://reviews.freebsd.org/D6434
