CLAT is customer-side translator that algorithmically translates 1:1
private IPv4 addresses to global IPv6 addresses, and vice versa.
It is implemented as part of ipfw_nat64 kernel module. When module
is loaded or compiled into the kernel, it registers "nat64clat" external
action. External action named instance can be created using `create`
command and then used in ipfw rules. The create command accepts two
IPv6 prefixes `plat_prefix` and `clat_prefix`. If plat_prefix is ommitted,
IPv6 NAT64 Well-Known prefix 64:ff9b::/96 will be used.
# ipfw nat64clat CLAT create clat_prefix SRC_PFX plat_prefix DST_PFX
# ipfw add nat64clat CLAT ip4 from IPv4_PFX to any out
# ipfw add nat64clat CLAT ip6 from DST_PFX to SRC_PFX in
Obtained from: Yandex LLC
Submitted by: Boris N. Lytochkin
MFC after: 1 month
Relnotes: yes
Sponsored by: Yandex LLC
This can be useful, when net.inet.ip.fw.dyn_keep_states is enabled, but
after rules reloading some state must be deleted. Added new flag '-D'
for such purpose.
Retire '-e' flag, since there can not be expired states in the meaning
that this flag historically had.
Also add "verbose" mode for listing of dynamic states, it can be enabled
with '-v' flag and adds additional information to states list. This can
be useful for debugging.
Obtained from: Yandex LLC
MFC after: 2 months
Sponsored by: Yandex LLC
that was added using "new rule format". And then, when the kernel
returns rule with this flag, ipfw(8) can correctly show it.
Reported by: lev
MFC after: 3 weeks
Sponsored by: Yandex LLC
Differential Revision: https://reviews.freebsd.org/D17373
"record-state" is similar to "keep-state", but it doesn't produce implicit
O_PROBE_STATE opcode in a rule. "set-limit" is like "limit", but it has the
same feature as "record-state", it is single opcode without implicit
O_PROBE_STATE opcode. "defer-action" is targeted to be used with dynamic
states. When rule with this opcode is matched, the rule's action will
not be executed, instead dynamic state will be created. And when this
state will be matched by "check-state", then rule action will be executed.
This allows create a more complicated rulesets.
Submitted by: lev
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D1776
o added struct ipfw_dyn_info that keeps all needed for ipfw_chk and
for dynamic states implementation information;
o added DYN_LOOKUP_NEEDED() macro that can be used to determine the
need of new lookup of dynamic states;
o ipfw_dyn_rule now becomes obsolete. Currently it used to pass
information from kernel to userland only.
o IPv4 and IPv6 states now described by different structures
dyn_ipv4_state and dyn_ipv6_state;
o IPv6 scope zones support is added;
o ipfw(4) now depends from Concurrency Kit;
o states are linked with "entry" field using CK_SLIST. This allows
lockless lookup and protected by mutex modifications.
o the "expired" SLIST field is used for states expiring.
o struct dyn_data is used to keep generic information for both IPv4
and IPv6;
o struct dyn_parent is used to keep O_LIMIT_PARENT information;
o IPv4 and IPv6 states are stored in different hash tables;
o O_LIMIT_PARENT states now are kept separately from O_LIMIT and
O_KEEP_STATE states;
o per-cpu dyn_hp pointers are used to implement hazard pointers and they
prevent freeing states that are locklessly used by lookup threads;
o mutexes to protect modification of lists in hash tables now kept in
separate arrays. 65535 limit to maximum number of hash buckets now
removed.
o Separate lookup and install functions added for IPv4 and IPv6 states
and for parent states.
o By default now is used Jenkinks hash function.
Obtained from: Yandex LLC
MFC after: 42 days
Sponsored by: Yandex LLC
Differential Revision: https://reviews.freebsd.org/D12685
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
No functional change intended.
This is similar to the TCP case. where a TCP RST segment can be sent.
There is one limitation: When sending an ABORT in response to an incoming
packet, it should be tested if there is no ABORT chunk in the received
packet. Currently, it is only checked if the first chunk is an ABORT
chunk to avoid parsing the whole packet, which could result in a DOS attack.
Thanks to Timo Voelker for helping me to test this patch.
Reviewed by: bcr@ (man page part), ae@ (generic, non-SCTP part)
Differential Revision: https://reviews.freebsd.org/D13239
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
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
Now zero value of arg1 used to specify "tablearg", use the old "tablearg"
value for "nat global". Introduce new macro IP_FW_NAT44_GLOBAL to replace
hardcoded magic number to specify "nat global". Also replace 65535 magic
number with corresponding macro. Fix typo in comments.
PR: 211256
Tested by: Victor Chernov
MFC after: 3 days
The keep-state, limit and check-state now will have additional argument
flowname. This flowname will be assigned to dynamic rule by keep-state
or limit opcode. And then can be matched by check-state opcode or
O_PROBE_STATE internal opcode. To reduce possible breakage and to maximize
compatibility with old rulesets default flowname introduced.
It will be assigned to the rules when user has omitted state name in
keep-state and check-state opcodes. Also if name is ambiguous (can be
evaluated as rule opcode) it will be replaced to default.
Reviewed by: julian
Obtained from: Yandex LLC
MFC after: 1 month
Relnotes: yes
Sponsored by: Yandex LLC
Differential Revision: https://reviews.freebsd.org/D6674
as defined in RFC 6296. The module works together with ipfw(4) and
implemented as its external action module. When it is loaded, it registers
as eaction and can be used in rules. The usage pattern is similar to
ipfw_nat(4). All matched by rule traffic goes to the NPT module.
Reviewed by: hrs
Obtained from: Yandex LLC
MFC after: 1 month
Relnotes: yes
Sponsored by: Yandex LLC
Differential Revision: https://reviews.freebsd.org/D6420
objects with the same name in different sets.
Add optional manage_sets() callback to objects rewriting framework.
It is intended to implement handler for moving and swapping named
object's sets. Add ipfw_obj_manage_sets() function that implements
generic sets handler. Use new callback to implement sets support for
lookup tables.
External actions objects are global and they don't support sets.
Modify eaction_findbyname() to reflect this.
ipfw(8) now may fail to move rules or sets, because some named objects
in target set may have conflicting names.
Note that ipfw_obj_ntlv type was changed, but since lookup tables
actually didn't support sets, this change is harmless.
Obtained from: Yandex LLC
Sponsored by: Yandex LLC
It allows implementing loadable kernel modules with new actions and
without needing to modify kernel headers and ipfw(8). The module
registers its action handler and keyword string, that will be used
as action name. Using generic syntax user can add rules with this
action. Also ipfw(8) can be easily modified to extend basic syntax
for external actions, that become a part base system.
Sample modules will coming soon.
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
Kernel changes:
* Split kernel/userland nat structures eliminating IPFW_INTERNAL hack.
* Add IP_FW_NAT44_* codes resemblin old ones.
* Assume that instances can be named (no kernel support currently).
* Use both UH+WLOCK locks for all configuration changes.
* Provide full ABI support for old sockopts.
Userland changes:
* Use IP_FW_NAT44_* codes for nat operations.
* Remove undocumented ability to show ranges of nat "log" entries.
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
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.
* Since there seems to be lack of consensus on strict value typing,
remove non-default value types. Use userland-only "value format type"
to print values.
Kernel changes:
* Add IP_FW_XMODIFY to permit table run-time modifications.
Currently we support changing limit and value format type.
Userland changes:
* Support IP_FW_XMODIFY opcode.
* Support specifying value format type (ftype) in tablble create/modify req
* Fine-print value type/value format type.
* 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.
Kernel changes:
* Add opcode IP_FW_TABLE_XSWAP
* Add support for swapping 2 tables with the same type/ftype/vtype.
* Make skipto cache init after ipfw locks init.
Userland changes:
* Add "table X swap Y" command.
Kernel changes:
* Add TEI_FLAGS_DONTADD entry flag to indicate that insert is not possible
* Support given flag in all algorithms
* Add "limit" field to ipfw_xtable_info
* Add actual limiting code into add_table_entry()
Userland changes:
* Add "limit" option as "create" table sub-option. Limit modification
is currently impossible.
* Print human-readable errors in table enry addition/deletion code.
* Add "flow:hash" algorithm
Kernel changes:
* Add O_IP_FLOW_LOOKUP opcode to support "flow" lookups
* Add IPFW_TABLE_FLOW table type
* Add "struct tflow_entry" as strage for 6-tuple flows
* Add "flow:hash" algorithm. Basically it is auto-growing chained hash table.
Additionally, we store mask of fields we need to compare in each instance/
* Increase ipfw_obj_tentry size by adding struct tflow_entry
* Add per-algorithm stat (ifpw_ta_tinfo) to ipfw_xtable_info
* Increase algoname length: 32 -> 64 (algo options passed there as string)
* Assume every table type can be customized by flags, use u8 to store "tflags" field.
* Simplify ipfw_find_table_entry() by providing @tentry directly to algo callback.
* Fix bug in cidr:chash resize procedure.
Userland changes:
* add "flow table(NAME)" syntax to support n-tuple checking tables.
* make fill_flags() separate function to ease working with _s_x arrays
* change "table info" output to reflect longer "type" fields
Syntax:
ipfw table fl2 create type flow:[src-ip][,proto][,src-port][,dst-ip][dst-port] [algo flow:hash]
Examples:
0:02 [2] zfscurr0# ipfw table fl2 create type flow:src-ip,proto,dst-port algo flow:hash
0:02 [2] zfscurr0# ipfw table fl2 info
+++ table(fl2), set(0) +++
kindex: 0, type: flow:src-ip,proto,dst-port
valtype: number, references: 0
algorithm: flow:hash
items: 0, size: 280
0:02 [2] zfscurr0# ipfw table fl2 add 2a02:6b8::333,tcp,443 45000
0:02 [2] zfscurr0# ipfw table fl2 add 10.0.0.92,tcp,80 22000
0:02 [2] zfscurr0# ipfw table fl2 list
+++ table(fl2), set(0) +++
2a02:6b8::333,6,443 45000
10.0.0.92,6,80 22000
0:02 [2] zfscurr0# ipfw add 200 count tcp from me to 78.46.89.105 80 flow 'table(fl2)'
00200 count tcp from me to 78.46.89.105 dst-port 80 flow table(fl2)
0:03 [2] zfscurr0# ipfw show
00200 0 0 count tcp from me to 78.46.89.105 dst-port 80 flow table(fl2)
65535 617 59416 allow ip from any to any
0:03 [2] zfscurr0# telnet -s 10.0.0.92 78.46.89.105 80
Trying 78.46.89.105...
..
0:04 [2] zfscurr0# ipfw show
00200 5 272 count tcp from me to 78.46.89.105 dst-port 80 flow table(fl2)
65535 682 66733 allow ip from any to any
Kernel changes:
* s/IPFW_TABLE_U32/IPFW_TABLE_NUMBER/
* Force "lookup <port|uid|gid|jid>" to be IPFW_TABLE_NUMBER
* Support "lookup" method for number tables
* Add number:array algorihm (i32 as key, auto-growing).
Userland changes:
* Support named tables in "lookup <tag> Table"
* Fix handling of "table(NAME,val)" case
* Support printing "number" table data.
* 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().
* Bump table dump format preserving old ABI.
Kernel size:
* Add IP_FW_TABLE_XFIND to handle "lookup" request from userland.
* Add ta_find_tentry() algorithm callbacks/handlers to support lookups.
* Fully switch to ipfw_obj_tentry for various table dumps:
algorithms are now required to support the latest (ipfw_obj_tentry) entry
dump format, the rest is handled by generic dump code.
IP_FW_TABLE_XLIST opcode version bumped (0 -> 1).
* Eliminate legacy ta_dump_entry algo handler:
dump_table_entry() converts data from current to legacy format.
Userland side:
* Add "lookup" table parameter.
* Change the way table type is guessed: call table_get_info() first,
and check value for IPv4/IPv6 type IFF table does not exist.
* Fix table_get_list(): do more tries if supplied buffer is not enough.
* Sparate table_show_entry() from table_show_list().
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.
