It is called when last reference to named object is going to be released
and allows to do additional cleanup for implementation of named objects.
Obtained from: Yandex LLC
Sponsored by: Yandex LLC
object name correctness. Each type of object can do more strict checking
in own implementation. Do such checks for tables in check_table_name().
Reviewed by: melifaro
Obtained from: Yandex LLC
Sponsored by: Yandex LLC
Currently we have tables identified by their names in userland
with internal kernel-assigned indices. This works the following way:
When userland wishes to communicate with kernel to add or change rule(s),
it makes indexed sorted array of table names
(internally ipfw_obj_ntlv entries), and refer to indices in that
array in rule manipulation.
Prior to committing new rule to the ruleset kernel
a) finds all referenced tables, bump their refcounts and change
values inside the opcodes to be real kernel indices
b) auto-creates all referenced but not existing tables and then
do a) for them.
Kernel does almost the same when exporting rules to userland:
prepares array of used tables in all rules in range, and
prepends it before the actual ruleset retaining actual in-kernel
indexes for that.
There is also special translation layer for legacy clients which is
able to provide 'real' indices for table names (basically doing atoi()).
While it is arguable that every subsystem really needs names instead of
numbers, there are several things that should be noted:
1) every non-singleton subsystem needs to store its runtime state
somewhere inside ipfw chain (and be able to get it fast)
2) we can't assume object numbers provided by humans will be dense.
Existing nat implementation (O(n) access and LIST inside chain) is a
good example.
Hence the following:
* Convert table-centric rewrite code to be more generic, callback-based
* Move most of the code from ip_fw_table.c to ip_fw_sockopt.c
* Provide abstract API to permit subsystems convert their objects
between userland string identifier and in-kernel index.
(See struct opcode_obj_rewrite) for more details
* Create another per-chain index (in next commit) shared among all subsystems
* Convert current NAT44 implementation to use new API, O(1) lookups,
shared index and names instead of numbers (in next commit).
Sponsored by: Yandex LLC
to obtain IPv4 next hop address in tablearg case.
Add `fwd tablearg' support for IPv6. ipfw(8) uses INADDR_ANY as next hop
address in O_FORWARD_IP opcode for specifying tablearg case. For IPv6 we
still use this opcode, but when packet identified as IPv6 packet, we
obtain next hop address from dedicated field nh6 in struct table_value.
Replace hopstore field in struct ip_fw_args with anonymous union and add
hopstore6 field. Use this field to copy tablearg value for IPv6.
Replace spare1 field in struct table_value with zoneid. Use it to keep
scope zone id for link-local IPv6 addresses. Since spare1 was used
internally, replace spare0 array with two variables spare0 and spare1.
Use getaddrinfo(3)/getnameinfo(3) functions for parsing and formatting
IPv6 addresses in table_value. Use zoneid field in struct table_value
to store sin6_scope_id value.
Since the kernel still uses embedded scope zone id to represent
link-local addresses, convert next_hop6 address into this form before
return from pfil processing. This also fixes in6_localip() check
for link-local addresses.
Differential Revision: https://reviews.freebsd.org/D2015
Obtained from: Yandex LLC
Sponsored by: Yandex LLC
* Ensure we're flushing entries without any locks held.
* Free memory in (rare) case when interface tracker fails to register ifp.
* Add KASSERT on table values refcounts.
This is the last major change in given branch.
Kernel changes:
* Use 64-bytes structures to hold multi-value variables.
* Use shared array to hold values from all tables (assume
each table algo is capable of holding 32-byte variables).
* Add some placeholders to support per-table value arrays in future.
* Use simple eventhandler-style API to ease the process of adding new
table items. Currently table addition may required multiple UH drops/
acquires which is quite tricky due to atomic table modificatio/swap
support, shared array resize, etc. Deal with it by calling special
notifier capable of rolling back state before actually performing
swap/resize operations. Original operation then restarts itself after
acquiring UH lock.
* Bump all objhash users default values to at least 64
* Fix custom hashing inside objhash.
Userland changes:
* Add support for dumping shared value array via "vlist" internal cmd.
* Some small print/fill_flags dixes to support u32 values.
* valtype is now bitmask of
<skipto|pipe|fib|nat|dscp|tag|divert|netgraph|limit|ipv4|ipv6>.
New values can hold distinct values for each of this types.
* Provide special "legacy" type which assumes all values are the same.
* More helpers/docs following..
Some examples:
3:41 [1] zfscurr0# ipfw table mimimi create valtype skipto,limit,ipv4,ipv6
3:41 [1] zfscurr0# ipfw table mimimi info
+++ table(mimimi), set(0) +++
kindex: 2, type: addr
references: 0, valtype: skipto,limit,ipv4,ipv6
algorithm: addr:radix
items: 0, size: 296
3:42 [1] zfscurr0# ipfw table mimimi add 10.0.0.5 3000,10,10.0.0.1,2a02:978:2::1
added: 10.0.0.5/32 3000,10,10.0.0.1,2a02:978:2::1
3:42 [1] zfscurr0# ipfw table mimimi list
+++ table(mimimi), set(0) +++
10.0.0.5/32 3000,0,10.0.0.1,2a02:978:2::1
own hash/compare functions.
* Add requirement for table algorithms to copy "valie" field in @add
callback instead of "prepare_add".
* Document existing requirement for table algorithms to store value
of deleted record to @tei.
Most of the tablearg-supported opcodes does not accept 0 as valid value:
O_TAG, O_TAGGED, O_PIPE, O_QUEUE, O_DIVERT, O_TEE, O_SKIPTO, O_CALLRET,
O_NETGRAPH, O_NGTEE, O_NAT treats 0 as invalid input.
The rest are O_SETDSCP and O_SETFIB.
'Fix' them by adding high-order bit (0x8000) set for non-tablearg values.
Do translation in kernel for old clients (import_rule0 / export_rule0),
teach current ipfw(8) binary to add/remove given bit.
This change does not affect handling SETDSCP values, but limit
O_SETFIB values to 32767 instead of 65k. Since currently we have either
old (16) or new (2^32) max fibs, this should not be a big deal:
we're definitely OK for former and have to add another opcode to deal
with latter, regardless of tablearg value.
* Implement proper checks for switching between global and set-aware tables
* Split IP_FW_DEL mess into the following opcodes:
* IP_FW_XDEL (del rules matching pattern)
* IP_FW_XMOVE (move rules matching pattern to another set)
* IP_FW_SET_SWAP (swap between 2 sets)
* IP_FW_SET_MOVE (move one set to another one)
* IP_FW_SET_ENABLE (enable/disable sets)
* Add IP_FW_XZERO / IP_FW_XRESETLOG to finish IP_FW3 migration.
* Use unified ipfw_range_tlv as range description for all of the above.
* Check dynamic states IFF there was non-zero number of deleted dyn rules,
* Del relevant dynamic states with singe traversal instead of per-rule one.
Userland changes:
* Switch ipfw(8) to use new opcodes.
This adds 512K (2 * sizeof(u32) * 65k) bytes to the memory footprint.
This feature is optionaly and may be turned on in any time
(however it starts immediately in this commit. This will be changed.)
* Use different approach to ensure algo has enough space to store N elements:
- explicitly ask algo (under UH_WLOCK) before/after insertion. This (along
with existing reallocation callbacks) really guarantees us that it is safe
to insert N elements at once while holding UH_WLOCK+WLOCK.
- remove old aflags/flags approach
The long-term goal is to switch remaining opcodes to IP_FW3 versions
and use ipfw_ctl3() as default handler simplifying ipfw(4) interaction
with external world.
* Rewrite interface tables to use interface indexes
Kernel changes:
* Add generic interface tracking API:
- ipfw_iface_ref (must call unlocked, performs lazy init if needed, allocates
state & bumps ref)
- ipfw_iface_add_ntfy(UH_WLOCK+WLOCK, links comsumer & runs its callback to
update ifindex)
- ipfw_iface_del_ntfy(UH_WLOCK+WLOCK, unlinks consumer)
- ipfw_iface_unref(unlocked, drops reference)
Additionally, consumer callbacks are called in interface withdrawal/departure.
* Rewrite interface tables to use iface tracking API. Currently tables are
implemented the following way:
runtime data is stored as sorted array of {ifidx, val} for existing interfaces
full data is stored inside namedobj instance (chained hashed table).
* Add IP_FW_XIFLIST opcode to dump status of tracked interfaces
* Pass @chain ptr to most non-locked algorithm callbacks:
(prepare_add, prepare_del, flush_entry ..). This may be needed for better
interaction of given algorithm an other ipfw subsystems
* Add optional "change_ti" algorithm handler to permit updating of
cached table_info pointer (happens in case of table_max resize)
* Fix small bug in ipfw_list_tables()
* Add badd (insert into sorted array) and bdel (remove from sorted array) funcs
Userland changes:
* Add "iflist" cmd to print status of currently tracked interface
* Add stringnum_cmp for better interface/table names sorting
* Switch kernel to use per-cpu counters for rules.
* Keep ABI/API.
Kernel changes:
* Each rules is now exported as TLV with optional extenable
counter block (ip_fW_bcounter for base one) and
ip_fw_rule for rule&cmd data.
* Counters needs to be explicitly requested by IPFW_CFG_GET_COUNTERS flag.
* Separate counters from rules in kernel and clean up ip_fw a bit.
* Pack each rule in IPFW_TLV_RULE_ENT tlv to ease parsing.
* Introduce versioning in container TLV (may be needed in future).
* Fix ipfw_cfg_lheader broken u64 alignment.
Userland changes:
* Use set_mask from cfg header when requesting config
* Fix incorrect read accouting in ipfw_show_config()
* Use IPFW_RULE_NOOPT flag instead of playing with _pad
* Fix "ipfw -d list": do not print counters for dynamic states
* Some small fixes
Kernel changes:
* Change dump format for dynamic states:
each state is now stored inside ipfw_obj_dyntlv
last dynamic state is indicated by IPFW_DF_LAST flag
* Do not perform sooptcopyout() for !SOPT_GET requests.
Userland changes:
* Introduce foreach_state() function handler to ease work
with different states passed by ipfw_dump_config().
Kernel changes:
* Introduce ipfw_obj_tentry table entry structure to force u64 alignment.
* Support "update-on-existing-key" "add" bahavior (TEI_FLAGS_UPDATED).
* Use "subtype" field to distingush between IPv4 and IPv6 table records
instead of previous hack.
* Add value type (vtype) field for kernel tables. Current types are
number,ip and dscp
* Fix sets mask retrieval for old binaries
* Fix crash while using interface tables
Userland changes:
* Switch ipfw_table_handler() to use named-only tables.
* Add "table NAME create [type {cidr|iface|u32} [valtype {number|ip|dscp}] ..."
* Switch ipfw_table_handler to match_token()-based parser.
* Switch ipfw_sets_handler to use new ipfw_get_config() for mask retrieval.
* Allow ipfw set X table ... syntax to permit using per-set table namespaces.
Kernel changes:
* change base TLV header to be u64 (so size can be u32).
* Introduce ipfw_obj_ctlv generc container TLV.
* Add IP_FW_XGET opcode which is now used for atomic configuration
retrieval. One can specify needed configuration pieces to retrieve
via flags field. Currently supported are
IPFW_CFG_GET_STATIC (static rules) and
IPFW_CFG_GET_STATES (dynamic states).
Other configuration pieces (tables, pipes, etc..) support is planned.
Userland changes:
* Switch ipfw(8) to use new IP_FW_XGET for rule listing.
* Split rule listing code get and show pieces.
* Make several steps forward towards libipfw:
permit printing states and rules(paritally) to supplied buffer.
do not die on malloc/kernel failure inside given printing functions.
stop assuming cmdline_opts is global symbol.
Instead of trying to allocate bing contiguous chunk of memory,
use intermediate-sized (page size) buffer as sliding window
reducing number of sooptcopyout() calls to perform.
This reduces dump functions complexity and provides additional
layer of abstraction.
User-visible api consists of 2 functions:
ipfw_get_sopt_space() - gets contigious amount of storage (or NULL)
and
ipfw_get_sopt_header() - the same, but zeroes the rest of the buffer.
* Add 'algoname' string to ipfw_xtable_info permitting to specify lookup
algoritm with parameters.
* Rework part of ipfw_rewrite_table_uidx()
Sponsored by: Yandex LLC
* Use one u16 from op3 header to implement opcode versioning.
* IP_FW_TABLE_XLIST has now 2 handlers, for ver.0 (old) and ver.1 (current).
* Every getsockopt request is now handled in ip_fw_table.c
* Rename new opcodes:
IP_FW_OBJ_DEL -> IP_FW_TABLE_XDESTROY
IP_FW_OBJ_LISTSIZE -> IP_FW_TABLES_XGETSIZE
IP_FW_OBJ_LIST -> IP_FW_TABLES_XLIST
IP_FW_OBJ_INFO -> IP_FW_TABLE_XINFO
IP_FW_OBJ_INFO -> IP_FW_TABLE_XFLUSH
* Add some docs about using given opcodes.
* Group some legacy opcode/handlers.
Kernel-side changelog:
* Split general tables code and algorithm-specific table data.
Current algorithms (IPv4/IPv6 radix and interface tables radix) moved to
new ip_fw_table_algo.c file.
Tables code now supports any algorithm implementing the following callbacks:
+struct table_algo {
+ char name[64];
+ int idx;
+ ta_init *init;
+ ta_destroy *destroy;
+ table_lookup_t *lookup;
+ ta_prepare_add *prepare_add;
+ ta_prepare_del *prepare_del;
+ ta_add *add;
+ ta_del *del;
+ ta_flush_entry *flush_entry;
+ ta_foreach *foreach;
+ ta_dump_entry *dump_entry;
+ ta_dump_xentry *dump_xentry;
+};
* Change ->state, ->xstate, ->tabletype fields of ip_fw_chain to
->tablestate pointer (array of 32 bytes structures necessary for
runtime lookups (can be probably shrinked to 16 bytes later):
+struct table_info {
+ table_lookup_t *lookup; /* Lookup function */
+ void *state; /* Lookup radix/other structure */
+ void *xstate; /* eXtended state */
+ u_long data; /* Hints for given func */
+};
* Add count method for namedobj instance to ease size calculations
* Bump ip_fw3 buffer in ipfw_clt 128->256 bytes.
* Improve bitmask resizing on tables_max change.
* Remove table numbers checking from most places.
* Fix wrong nesting in ipfw_rewrite_table_uidx().
* Add IP_FW_OBJ_LIST opcode (list all objects of given type, currently
implemented for IPFW_OBJTYPE_TABLE).
* Add IP_FW_OBJ_LISTSIZE (get buffer size to hold IP_FW_OBJ_LIST data,
currenly implemented for IPFW_OBJTYPE_TABLE).
* Add IP_FW_OBJ_INFO (requests info for one object of given type).
Some name changes:
s/ipfw_xtable_tlv/ipfw_obj_tlv/ (no table specifics)
s/ipfw_xtable_ntlv/ipfw_obj_ntlv/ (no table specifics)
Userland changes:
* Add do_set3() cmd to ipfw2 to ease dealing with op3-embeded opcodes.
* Add/improve support for destroy/info cmds.
* Add namedobject set-aware api capable of searching/allocation objects by their name/idx.
* Switch tables code to use string ids for configuration tasks.
* Change locking model: most configuration changes are protected with UH lock, runtime-visible are protected with both locks.
* Reduce number of arguments passed to ipfw_table_add/del by using separate structure.
* Add internal V_fw_tables_sets tunable (set to 0) to prepare for set-aware tables (requires opcodes/client support)
* Implement typed table referencing (and tables are implicitly allocated with all state like radix ptrs on reference)
* Add "destroy" ipfw(8) using new IP_FW_DELOBJ opcode
Namedobj more detailed:
* Blackbox api providing methods to add/del/search/enumerate objects
* Statically-sized hashes for names/indexes
* Per-set bitmask to indicate free indexes
* Separate methods for index alloc/delete/resize
Basically, there should not be any user-visible changes except the following:
* reducing table_max is not supported
* flush & add change table type won't work if table is referenced
Sponsored by: Yandex LLC
* Do per vnet instance cleanup (previously it was only for vnet0 on
module unload, and led to libalias leaks and possible panics due to
stale pointer dereferences).
* Instead of protecting ipfw hooks registering/deregistering by only
vnet0 lock (which does not prevent pointers access from another
vnets), introduce per vnet ipfw_nat_loaded variable. The variable is
set after hooks are registered and unset before they are deregistered.
* Devirtualize ifaddr_event_tag as we run only one event handler for
all vnets.
* It is supposed that ifaddr_change event handler is called in the
interface vnet context, so add an assertion.
Reviewed by: zec
MFC after: 2 weeks
* Global IPFW_DYN_LOCK() is changed to per-bucket mutex.
* State expiration is done in ipfw_tick every second.
* No expiration is done on forwarding path.
* hash table resize is done automatically and does not flush all states.
* Dynamic UMA zone is now allocated per each VNET
* State limiting is now done via UMA(9) api.
Discussed with: ipfw
MFC after: 3 weeks
Sponsored by: Yandex LLC
