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* xshared: Store parsed wait and wait_interval in xtables_argsPhil Sutter2022-01-121-5/+3
| | | | | | While nft-variants don't care, legacy ones do. Signed-off-by: Phil Sutter <phil@nwl.cc>
* xshared: Move do_parse to shared spacePhil Sutter2022-01-121-0/+553
| | | | | | | | | | | Small adjustments were needed: - Pass line variable via xt_cmd_parse, xshared.c does not have it in namespace. - Replace opts, prog_name and prog_vers defines by the respective xt_params field reference. Signed-off-by: Phil Sutter <phil@nwl.cc>
* xshared: Share exit_tryhelp()Phil Sutter2021-12-161-0/+10
| | | | | | | The function existed three times in identical form. Avoid having to declare extern int line in xshared.c by making it a parameter. Signed-off-by: Phil Sutter <phil@nwl.cc>
* xshared: Share a common printhelp functionPhil Sutter2021-12-161-0/+103
| | | | | | | | | | | | | Help texts in legacy and nft variants are supposed to be identical, but those of iptables and ip6tables largely overlapped already. By referring to xt_params and afinfo pointers, it is relatively trivial to craft a suitable help text on demand, so duplicated help texts can be eliminated. As a side-effect, this fixes ip6tables-nft help text - it was identical to that of iptables-nft. Signed-off-by: Phil Sutter <phil@nwl.cc>
* xshared: Share print_match_save() between legacy ip*tablesPhil Sutter2021-12-161-0/+30
| | | | | | | | The only difference between the former two copies was the type of ip*_entry parameter. But since it is treated opaque, just hide that detail by casting to void. Signed-off-by: Phil Sutter <phil@nwl.cc>
* xshared: Make load_proto() staticPhil Sutter2021-11-231-1/+1
| | | | | | | The last outside users vanished ten years ago. Fixes: 449cdd6bcc8d1 ("src: combine default_command functions") Signed-off-by: Phil Sutter <phil@nwl.cc>
* xshared: Share print_header() with legacy iptablesPhil Sutter2021-11-231-0/+46
| | | | | | | | | | | | | | | Legacy iptables fetches the relevant data via libiptc before calling the shared routine which merely prints data as requested. Drop the 'basechain' parameter, instead make sure a policy name is passed only with base chains. Since the function is not shared with ebtables (which uses a very rudimental header instead), this is safe. In order to support legacy iptables' checking of iptc_get_references() return code (printing an error message instead of the reference count), make refs parameter signed and print the error message if it's negative. Signed-off-by: Phil Sutter <phil@nwl.cc>
* xshared: Share print_fragment() with legacyPhil Sutter2021-11-231-0/+18
| | | | | | | | | | | Also add a fake mode to make it suitable for ip6tables. This is required because IPT_F_FRAG value clashes with IP6T_F_PROTO, so ip6tables rules might seem to have IPT_F_FRAG bit set. While being at it, drop the local variable 'flags' from print_firewall(). Signed-off-by: Phil Sutter <phil@nwl.cc>
* xshared: Share print_rule_details() with legacyPhil Sutter2021-11-231-1/+26
| | | | | | | | | | Have to pass pointer to counters directly since different fields are being used for some reason. Since proto_to_name() is not used outside of xshared.c anymore, make it static. Signed-off-by: Phil Sutter <phil@nwl.cc>
* xshared: Share save_ipv{4,6}_addr() with legacyPhil Sutter2021-11-231-0/+57
| | | | | | | While being at it, make save_ipv4_addr() accept an in_addr* as mask - mask_to_str() needs it anyway. Signed-off-by: Phil Sutter <phil@nwl.cc>
* xshared: Share save_rule_details() with legacyPhil Sutter2021-11-231-0/+32
| | | | | | | | | | The function combines printing of input and output interfaces and protocol parameter, all being IP family independent. Extend the function to print fragment option ('-f'), too if requested. While being at it, drop unused iptables_command_state parameter and reorder the remaining ones a bit. Signed-off-by: Phil Sutter <phil@nwl.cc>
* xshared: Share print_iface() functionPhil Sutter2021-11-231-0/+25
| | | | | | | | | | | Merge the three identical copies into one and name it 'save_iface' (as the printed syntax is for "save"-format). Leave arptables alone for now, its rather complicated whitespace printing doesn't allow for use of the shared function. Also keep ebtables' custom implementation, it is used for the --logical-in/--logical-out long-options, too. Apart from that, ebtables-nft does not use a mask, at all. Signed-off-by: Phil Sutter <phil@nwl.cc>
* xshared: Merge and share parse_chain()Phil Sutter2021-11-231-0/+24
| | | | | | | Have a common routine to perform chain name checks, combining all variants' requirements. Signed-off-by: Phil Sutter <phil@nwl.cc>
* nft: Use xtables_{m,c}alloc() everywherePhil Sutter2021-08-311-6/+2
| | | | | | | | | | Make use of libxtables allocators where sensible to have implicit error checking. Leave library-internal calls in place to not create unexpected program exit points for users, apart from xt_xlate_alloc() as that function called xtables_error() in error case which exits by itself already. Signed-off-by: Phil Sutter <phil@nwl.cc>
* libxtables: Introduce xtables_strdup() and use it everywherePhil Sutter2021-06-071-1/+1
| | | | | | This wraps strdup(), checking for errors. Signed-off-by: Phil Sutter <phil@nwl.cc>
* Use proto_to_name() from xshared in more placesPhil Sutter2021-05-171-1/+1
| | | | | | | | | | Share the common proto name lookup code. While being at it, make proto number variable 16bit, values may exceed 256. This aligns iptables-nft '-p' argument printing with legacy iptables. In practice, this should make a difference only in corner cases. Signed-off-by: Phil Sutter <phil@nwl.cc>
* xshared: Merge invflags handling codePhil Sutter2021-05-171-0/+43
| | | | | | | | | | Join invflags handling between iptables, ip6tables, xtables and arptables. Ebtables still has its own code which differs quite a bit. In order to use a shared set_option() routine, iptables and ip6tables need to provide a local 'invflags' variable which is 16bits wide. Signed-off-by: Phil Sutter <phil@nwl.cc>
* xshared: Eliminate iptables_command_state->invertPhil Sutter2021-05-171-5/+5
| | | | | | | | | This field is not used by routines working with struct iptables_command_state: It is merely a temporary flag used by parsers to carry the '!' prefix until invflags have been populated (or error checking done if unsupported). Signed-off-by: Phil Sutter <phil@nwl.cc>
* nft-arp: Make use of ipv4_addr_to_string()Phil Sutter2021-04-301-3/+3
| | | | | | | This eliminates quite a bit of redundant code apart from also dropping use of obsolete function gethostbyaddr(). Signed-off-by: Phil Sutter <phil@nwl.cc>
* xshared: Merge some command option-related codePhil Sutter2020-12-031-0/+74
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Add OPT_FRAGMENT define into the enum of other OPT_* defines at the right position and adjust the arptables-specific ones that follow accordingly. Appropriately adjust inverse_for_options array in xtables-arp.c. Extend optflags from iptables.c by the arptables values for the sake of completeness, then move it to xshared.h along with NUMBER_OF_OPT definition. As a side-effect, this fixes for wrong ordering of entries in arptables' 'optflags' copy. Add arptables-specific bits to commands_v_options table (the speicific options are matches on ARP header fields, just treat them like '-s' option. This is also just a cosmetic change, arptables doesn't have a generic_opt_check() implementation and hence doesn't use such a table. With things potentially ready for common use, move commands_v_options table along with generic_opt_check() and opt2char() into xshared.c and drop the local (identical) implementations from iptables.c, ip6tables.c xtables.c and xtables-arp.c. While doing so, fix ordering of entries in that table: the row for CMD_ZERO_NUM was in the wrong position. Since all moved rows though are identical, this had no effect in practice. Fixes: d960a991350ca ("xtables-arp: Integrate OPT_* defines into xshared.h") Fixes: 384958620abab ("use nf_tables and nf_tables compatibility interface") Signed-off-by: Phil Sutter <phil@nwl.cc>
* iptables: accept lock file name at runtimeGiuseppe Scrivano2020-07-241-3/+8
| | | | | | | | | | | | | | | allow users to override at runtime the lock file to use through the XTABLES_LOCKFILE environment variable. It allows to use iptables when the user has granted enough capabilities (e.g. a user+network namespace) to configure the network but that lacks access to the XT_LOCK_NAME (by default placed under /run). $ XTABLES_LOCKFILE=/tmp/xtables unshare -rn iptables ... Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* xshared: Drop pointless assignment in add_param_to_argv()Phil Sutter2020-04-231-1/+0
| | | | | | This must be a leftover from a previous cleanup. Signed-off-by: Phil Sutter <phil@nwl.cc>
* xtables-restore: Allow lines without trailing newline characterPhil Sutter2019-11-061-0/+4
| | | | | | | | | | | | | | | Old code in add_param_to_argv() assumed the input line would always end with a newline character. Without it, the last word of input wasn't recognized. Fix this by adding a final check for param.len (indicating leftover data in buffer). In line parsing code itself, only COMMIT line check required presence of trailing newline. The replaced conditional is not 100% accurate as it allows for characters after newline to be present, but since fgets() is used this shouldn't happen anyway. Signed-off-by: Phil Sutter <phil@nwl.cc> Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
* xshared: Share a common implementation of parse_rulenumber()Phil Sutter2019-10-301-0/+12
| | | | | | | The function is really small, but still copied four times. Signed-off-by: Phil Sutter <phil@nwl.cc> Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
* xshared: Share a common add_command() implementationPhil Sutter2019-10-301-0/+27
| | | | | | | | | | | The shared definition of cmdflags is a super set of the previous one in xtables-arp.c so while not being identical, they're compatible. Avoid accidental array overstep in cmd2char() by incrementing an index variable and checking its final value before using it as such. Signed-off-by: Phil Sutter <phil@nwl.cc> Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
* xshared: Introduce struct argv_storePhil Sutter2019-10-241-37/+39
| | | | | | | | | | | | The use of global variables in code around add_argv() is error-prone and hard to follow. Replace them by a struct which functions will modify instead of causing side-effects. Given the lack of static variables, this effectively makes argv construction code reentrant. Signed-off-by: Phil Sutter <phil@nwl.cc> Acked-by: Florian Westphal <fw@strlen.de>
* iptables-xml: Use add_param_to_argv()Phil Sutter2019-10-241-2/+4
| | | | | | | | | Extend the shared argv parser by storing whether a given argument was quoted or not, then use it in iptables-xml. One remaining extra bit is extraction of chain name in -A commands, do that afterwards in a loop. Signed-off-by: Phil Sutter <phil@nwl.cc> Acked-by: Florian Westphal <fw@strlen.de>
* xtables-restore: Fix --table parameter checkPhil Sutter2019-10-211-12/+0
| | | | | | | | | | | | | | | | | | | | | Xtables-restore tries to reject rule commands in input which contain a --table parameter (since it is adding this itself based on the previous table line). The manual check was not perfect though as it caught any parameter starting with a dash and containing a 't' somewhere, even in rule comments: | *filter | -A FORWARD -m comment --comment "- allow this one" -j ACCEPT | COMMIT Instead of error-prone manual checking, go a much simpler route: All do_command callbacks are passed a boolean indicating they're called from *tables-restore. React upon this when handling a table parameter and error out if it's not the first one. Fixes: f8e5ebc5986bf ("iptables: Fix crash on malformed iptables-restore") Signed-off-by: Phil Sutter <phil@nwl.cc> Acked-by: Florian Westphal <fw@strlen.de>
* xtables-restore: Introduce rule counter tokenizer functionPhil Sutter2019-10-181-0/+37
| | | | | | | | | | | | | | The same piece of code appears three times, introduce a function to take care of tokenizing and error reporting. Pass buffer pointer via reference so it can be updated to point to after the counters (if found). While being at it, drop pointless casting when passing pcnt/bcnt to add_argv(). Signed-off-by: Phil Sutter <phil@nwl.cc> Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
* xtables_error() does not returnPhil Sutter2019-09-251-1/+0
| | | | | | | | | It's a define which resolves into a callback which in turn is declared with noreturn attribute. It will never return, therefore drop all explicit exit() calls or other dead code immediately following it. Signed-off-by: Phil Sutter <phil@nwl.cc> Acked-by: Florian Westphal <fw@strlen.de>
* xshared: check for maximum buffer length in add_param_to_argv()Pablo Neira Ayuso2019-04-301-18/+28
| | | | | | | Bail out if we go over the boundary, based on patch from Sebastian. Reported-by: Sebastian Neef <contact@0day.work> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* xshared: Explicitly pass target to command_jump()Phil Sutter2019-02-071-2/+2
| | | | | | | | | The use of global 'optarg' variable inside that function is a mess, but most importantly it limits its applicability to input parsers. Fix this by having it take the option argument as a parameter. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Florian Westphal <fw@strlen.de>
* xtables: Remove target_maxnamelen fieldPhil Sutter2018-10-151-3/+3
| | | | | | | | | | | | This is a partial revert of commit 9f075031a1973 ("Combine parse_target() and command_jump() implementations"): Upstream prefers to reduce max chain name length of arptables by two characters instead of the introduced struct xtables_globals field which requires to bump library API version. Fixes: 9f075031a1973 ("Combine parse_target() and command_jump() implementations") Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* Combine parse_target() and command_jump() implementationsPhil Sutter2018-09-251-0/+63
| | | | | | | | | | | | | | | | | | | | | | | | | | | Merge these two functions from xtables, iptables, ip6tables and arptables. Both functions were basically identical in the first three, only the last one required a bit more attention. To eliminate access to 'invflags' in variant-specific location, move the call to set_option() into callers. This is actually consistent with parsing of other options in them. As with command_match(), use xt_params instead of the different *_globals objects to refer to 'opts' and 'orig_opts'. It was necessary to rename parse_target() as it otherwise clashes with a static function of same name in libxt_SET. In arptables, the maximum allowed target name is a bit larger, so introduce xtables_globals.target_maxnamelen defining the value. It is used in the shared xt_parse_target() implementation. Implementation of command_jump() in arptables diverted from the others for no obvious reason. The call to parse_target() was done outside of it and a pointer to cs->arp was passed but not used inside. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Florian Westphal <fw@strlen.de>
* Combine command_match() implementationsPhil Sutter2018-09-251-0/+38
| | | | | | | | | | This merges the basically identical implementations of command_match() from xtables, iptables and ip6tables into one. The only required adjustment was to make use of xt_params instead of the different *_globals objects. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Florian Westphal <fw@strlen.de>
* iptables: Use print_ifaces() from xtablesPhil Sutter2018-09-241-0/+25
| | | | | | | | | | Move the function to xshared.c for common use between legacy and xtables sources. While being at it, silence a covscan warning triggered by that function as it couldn't verify input buffers won't exceed IFNAMSIZ. Therefore use snprintf() when writing to the local buffer. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Florian Westphal <fw@strlen.de>
* Share print_ipv{4,6}_addr() from xtablesPhil Sutter2018-09-241-0/+66
| | | | | | | | | | | | | | | | These functions contain code which occurs in legacy's print_firewall() functions, so use them there. Rename them to at least make clear they print more than a single address. Also introduce ipv{4,6}_addr_to_string() which take care of converting an address/netmask pair into string representation in a way which doesn't upset covscan (since that didn't detect that 'buf' may not be exceeded by the strings written into it. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Florian Westphal <fw@strlen.de>
* xshared: Consolidate argv construction routinesPhil Sutter2018-08-041-0/+123
| | | | | | | | | | | | | | | | | | | | | Implementations were equal in {ip,ip6,x}tables-restore.c. The one in iptables-xml.c differed slightly. For now, collect all features together. Maybe it would make sense to migrate iptables-xml.c to using add_param_to_argv() at some point and therefore extend the latter to store whether a given parameter was quoted or not. While being at it, a few improvements were done: * free_argv() now also resets 'newargc' variable, so users don't have to do that anymore. * Indenting level in add_param_to_argv() was reduced a bit. * That long error message is put into a single line to aid in grepping for it. * Explicit call to exit() after xtables_error() is removed since the latter does not return anyway. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Florian Westphal <fw@strlen.de>
* xshared: Consolidate parse_counters()Phil Sutter2018-08-041-0/+14
| | | | | | | | | Move this helper function into xshared. While being at it, drop the need for temporary variables and take over null pointer tolerance from the implementation in iptables-xml.c. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Florian Westphal <fw@strlen.de>
* ip{,6}tables-restore: Don't ignore missing wait-interval valuePhil Sutter2017-10-041-1/+1
| | | | | | | | Passing -W without a value doesn't make sense so bail out if none was given. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* iptables: insist that the lock is held.Lorenzo Colitti2017-05-291-3/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, iptables programs will exit with an error if the iptables lock cannot be acquired, but will silently continue if the lock cannot be opened at all. This can cause unexpected failures (with unhelpful error messages) in the presence of concurrent updates, which can be very difficult to find in a complex or multi-administrator system. Instead, refuse to do anything if the lock cannot be acquired. The behaviour is not affected by command-line flags because: 1. In order to reliably avoid concurrent modification, all invocations of iptables commands must follow this behaviour. 2. Whether or not the lock can be opened is typically not a run-time condition but is likely to be a configuration error. Existing systems that depended on things working mostly correctly even if there was no lock might be affected by this change. However, that is arguably a configuration error, and now that the iptables lock is configurable, it is trivial to provide a lock file that is always accessible: if nothing else, the iptables binary itself can be used. The lock does not have to be writable, only readable. Tested by configuring the system to use an xtables.lock file in a non-existent directory and observing that all commands failed. Signed-off-by: Lorenzo Colitti <lorenzo@google.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* iptables-restore: support acquiring the lock.Lorenzo Colitti2017-03-211-6/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, ip[6]tables-restore does not perform any locking, so it is not safe to use concurrently with ip[6]tables. This patch makes ip[6]tables-restore wait for the lock if -w was specified. Arguments to -w and -W are supported in the same was as they are in ip[6]tables. The lock is not acquired on startup. Instead, it is acquired when a new table handle is created (on encountering '*') and released when the table is committed (COMMIT). This makes it possible to keep long-running iptables-restore processes in the background (for example, reading commands from a pipe opened by a system management daemon) and simultaneously run iptables commands. If -w is not specified, then the command proceeds without taking the lock. Tested as follows: 1. Run iptables-restore -w, and check that iptables commands work with or without -w. 2. Type "*filter" into the iptables-restore input. Verify that a) ip[6]tables commands without -w fail with "another app is currently holding the xtables lock...". b) ip[6]tables commands with "-w 2" fail after 2 seconds. c) ip[6]tables commands with "-w" hang until "COMMIT" is typed into the iptables-restore window. 3. With the lock held by an ip6tables-restore process: strace -e flock /tmp/iptables/sbin/iptables-restore -w 1 -W 100000 shows 11 calls to flock and fails. 4. Run an iptables-restore with -w and one without -w, and check: a) Type "*filter" in the first and then the second, and the second exits with an error. b) Type "*filter" in the second and "*filter" "-S" "COMMIT" into the first. The rules are listed only when the first copy sees "COMMIT". Signed-off-by: Narayan Kamath <narayan@google.com> Signed-off-by: Lorenzo Colitti <lorenzo@google.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* iptables: remove duplicated argument parsing codeLorenzo Colitti2017-03-171-2/+33
| | | | | | | | | | 1. Factor out repeated code to a new xs_has_arg function. 2. Add a new parse_wait_time option to parse the value of -w. 3. Make parse_wait_interval take argc and argv so its callers can be simpler. Signed-off-by: Lorenzo Colitti <lorenzo@google.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* iptables: move XT_LOCK_NAME from CFLAGS to config.h.Lorenzo Colitti2017-03-171-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This slightly simplifies configure.ac and results in more correct dependencies. Tested by running ./configure with --with-xt-lock-name and without, and using strace to verify that the right lock is used. $ make distclean-recursive && ./autogen.sh && ./configure --disable-nftables --prefix /tmp/iptables && make -j64 && make install && sudo strace -e open,flock /tmp/iptables/sbin/iptables -L foo ... open("/run/xtables.lock", O_RDONLY|O_CREAT, 0600) = 3 flock(3, LOCK_EX|LOCK_NB) = 0 $ make distclean-recursive && ./autogen.sh && \ ./configure --disable-nftables --prefix /tmp/iptables \ --with-xt-lock-name=/tmp/iptables/run/xtables.lock && make -j64 && make install && sudo strace -e open,flock /tmp/iptables/sbin/iptables -L foo ... open("/tmp/iptables/run/xtables.lock", O_RDONLY|O_CREAT, 0600) = 3 flock(3, LOCK_EX|LOCK_NB) = 0 Signed-off-by: Lorenzo Colitti <lorenzo@google.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* iptables: set the path of the lock file via a configure option.Lorenzo Colitti2017-03-141-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the iptables lock is hardcoded as "/run/xtables.lock". Allow users to change this path using the --with-xt-lock-name option to ./configure option. This is useful on systems like Android which do not have /run. Tested on Ubuntu, as follows: 1. By default, the lock is placed in /run/xtables.lock: $ make distclean-recursive && ./autogen.sh && ./configure --disable-nftables --prefix /tmp/iptables && make -j64 && make install && sudo strace -e open,flock /tmp/iptables/sbin/iptables -L foo ... open("/run/xtables.lock", O_RDONLY|O_CREAT, 0600) = 3 flock(3, LOCK_EX|LOCK_NB) = 0 iptables: No chain/target/match by that name. 2. Specifying the lock results in the expected location being used: $ make distclean-recursive && ./autogen.sh && \ ./configure --disable-nftables --prefix /tmp/iptables \ --with-xt-lock-name=/tmp/iptables/run/xtables.lock && make -j64 && make install && sudo strace -e open,flock /tmp/iptables/sbin/iptables -L foo ... open("/tmp/iptables/run/xtables.lock", O_RDONLY|O_CREAT, 0600) = 3 flock(3, LOCK_EX|LOCK_NB) = 0 iptables: No chain/target/match by that name. Signed-off-by: Lorenzo Colitti <lorenzo@google.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* xshared: using the blocking file lock request when we wait indefinitelyLiping Zhang2017-02-281-11/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When using "-w" to avoid concurrent instances, we try to do flock() every one second until it success. But one second maybe too long in some situations, and it's hard to select a suitable interval time. So when using "iptables -w" to wait indefinitely, it's better to block until it become success. Now do some performance tests. First, flush all the iptables rules in filter table, and run "iptables -w -S" endlessly: # iptables -F # iptables -X # while : ; do iptables -w -S >&- & done Second, after adding and deleting the iptables rules 100 times, measure the time cost: # time for i in $(seq 100); do iptables -w -A INPUT iptables -w -D INPUT done Before this patch: real 1m15.962s user 0m0.224s sys 0m1.475s Apply this patch: real 0m1.830s user 0m0.168s sys 0m1.130s Signed-off-by: Liping Zhang <zlpnobody@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* xshared: do not lock again and again if "-w" option is not specifiedLiping Zhang2017-02-281-7/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | After running the following commands, some confusing messages was printed out: # while : ; do iptables -A INPUT & iptables -D INPUT & done [...] Another app is currently holding the xtables lock; still -9s 0us time ahead to have a chance to grab the lock... Another app is currently holding the xtables lock; still -29s 0us time ahead to have a chance to grab the lock... If "-w" option is not specified, the "wait" will be zero, so we should check whether the timer_left is less than wait_interval before we call select to sleep. Also remove unused "BASE_MICROSECONDS" and "struct timeval waited_time" introduced by commit e8f857a5a151 ("xtables: Add an interval option for xtables lock wait"). Fixes: e8f857a5a151 ("xtables: Add an interval option for xtables lock wait") Signed-off-by: Liping Zhang <zlpnobody@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* xtables: Add an interval option for xtables lock waitSubash Abhinov Kasiviswanathan2016-07-031-8/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ip[6]tables currently waits for 1 second for the xtables lock to be freed if the -w option is used. We have seen that the lock is held much less than that resulting in unnecessary delay when trying to acquire the lock. This problem is even severe in case of latency sensitive applications. Introduce a new option 'W' to specify the wait interval in microseconds. If this option is not specified, the command sleeps for 1 second by default. v1->v2: Change behavior to take millisecond sleep as an argument to -w as suggested by Pablo. Also maintain current behavior for -w to sleep for 1 second as mentioned by Liping. v2->v3: Move the millisecond behavior to a new option as suggested by Pablo. v3->v4: Use select instead of usleep. Sleep every iteration for the time specified in the "-W" argument. Update man page. v4->v5: Fix compilation error when enabling nftables v5->v6: Simplify -W so it only takes the interval wait in microseconds. Bail out if -W is specific but -w is not. Joint work with Pablo Neira. Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* xshared: calm down compilation warningPablo Neira Ayuso2015-02-181-0/+1
| | | | | | | xshared.c: In function ‘xtables_lock’: xshared.c:255:3: warning: implicit declaration of function ‘flock’ [-Wimplicit-function-declaration] Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* iptables: use flock() instead of abstract unix socketsPablo Neira Ayuso2015-01-201-15/+7
| | | | | | | | | | | | | Abstract unix sockets cannot be used to synchronize several concurrent instances of iptables since an unpriviledged process can create them and prevent the legitimate iptables instance from running. Use flock() and /run instead as suggested by Lennart Poettering. Fixes: 93587a0 ("ip[6]tables: Add locking to prevent concurrent instances") Reported-by: Lennart Poettering <lennart@poettering.net> Cc: Phil Oester <kernel@linuxace.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>