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* src: add 'auto-merge' option to setsPablo Neira Ayuso2018-01-221-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After discussions with Karel here: https://bugzilla.netfilter.org/show_bug.cgi?id=1184 And later on with Phil Sutter, we decided to disable the automatic merge feature in sets with intervals. This feature is problematic because it introduces an inconsistency between what we add and what we later on get. This is going to get worse with the upcoming timeout support for intervals. Therefore, we turned off this by default. However, Jeff Kletsky and folks like this feature, so let's restore this behaviour on demand with this new 'auto-merge' statement, that you can place on the set definition, eg. # nft list ruleset table ip x { ... set y { type ipv4_addr flags interval auto-merge } } # nft add element x z { 1.1.1.1-2.2.2.2, 1.1.1.2 } Regarding implementation details: Given this feature only makes sense from userspace, let's store this in the set user data area, so nft knows it has to do automatic merge of adjacent/overlapping elements as per user request. # nft add set x z { type ipv4_addr\; auto-merge\; } Error: auto-merge only works with interval sets add set x z { type ipv4_addr; auto-merge; } ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Fixes: https://bugzilla.netfilter.org/show_bug.cgi?id=1216 Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: Don't merge adjacent/overlapping rangesPhil Sutter2018-01-111-0/+1
| | | | | | | | | | | | | | | | | | | | | Previously, when adding multiple ranges to a set they were merged if overlapping or adjacent. This might cause inconvenience though since it is afterwards not easily possible anymore to remove one of the merged ranges again while keeping the others in place. Since it is not possible to have overlapping ranges, this patch adds a check for newly added ranges to make sure they don't overlap if merging is turned off. Note that it is not possible (yet?) to enable range merging using nft tool. Testsuite had to be adjusted as well: One test in tests/py changed avoid adding overlapping ranges and the test in tests/shell which explicitly tests for this feature dropped. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* libnftables: Ensure output_fp is never NULLPhil Sutter2017-11-221-6/+4
| | | | | | | | | | | | | | Initialize output_fp to 'stdout' upon context creation and check output stream validity in nft_ctx_set_output(). This allows to drop checks in nft_{gmp_,}print() and do_command_export(). While doing so for the latter, simplify it a bit by using nft_print() which takes care of flushing the output stream. If applications desire to drop all output, they are supposed to open /dev/null and assign that. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* libnftables: Unexport enum nftables_exit_codesPhil Sutter2017-11-161-5/+5
| | | | | | | | | | | | | | | | Apart from SUCCESS/FAILURE, these codes were not used by library functions simply because NOMEM and NONL conditions lead to calling exit() instead of propagating the error condition back up the call stack. Instead, make nft_run_cmd_from_*() return either 0 or -1 on error. Usually errno will then contain more details about what happened and/or there are messages in erec. Calls to exit()/return in main() are adjusted to stay compatible. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* libnftables: Flush iface cache after command executionPhil Sutter2017-11-131-0/+2
| | | | | | | | | | | | | | Commit 94a945ffa81b7 ("libnftables: Get rid of explicit cache flushes") was a bit too optimistic in that it missed the remaining need to flush interface cache after each command in interactive mode - otherwise, newly added interfaces won't be recognized. Although cli.c only calls nft_run_cmd_from_buffer(), flush caches in nft_run_cmd_from_filename() as well for matters of consistency. Fixes: 94a945ffa81b7 ("libnftables: Get rid of explicit cache flushes") Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* libnftables: Get rid of explicit cache flushesPhil Sutter2017-10-261-7/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the past, CLI as a potentially long running process had to make sure it kept it's cache up to date with kernel's rule set. A simple test case is this: | shell a | shell b | | # nft -i | # nft add table ip t | | | nft> list ruleset | | table ip t { | | } | # nft flush ruleset | | | nft> list ruleset | | nft> In order to make sure interactive CLI wouldn't incorrectly list the table again in the second 'list' command, it immediately flushed it's cache after every command execution. This patch eliminates the need for that by making cache updates depend on kernel's generation ID: A cache update stores the current rule set's ID in struct nft_cache, consecutive calls to cache_update() compare that stored value to the current generation ID received from kernel - if the stored value is zero (i.e. no previous cache update did happen) or if it doesn't match the kernel's value (i.e. cache is outdated) the cache is flushed and fully initialized again. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: add nft_ prefix to everything exposed through include/nftables/nftables.hPablo Neira Ayuso2017-10-241-2/+3
| | | | | | | | Prepend nft_ prefix before these are exposed, reduce chances we hit symbol namespace pollution problems when mixing libnftables with other existing libraries. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* libnftables: Introduce getters and setters for everythingPhil Sutter2017-10-241-2/+99
| | | | | | | | | | | | | | | | | | | | | | | | | This introduces getter/setter pairs for all parts in struct nft_ctx (and contained structs) which should be configurable. Most of them are simple ones, just allowing to get/set a given field: * nft_ctx_{get,set}_dry_run() -> ctx->check * nft_ctx_output_{get,set}_numeric() -> ctx->output.numeric * nft_ctx_output_{get,set}_stateless() -> ctx->output.stateless * nft_ctx_output_{get,set}_ip2name() -> ctx->output.ip2name * nft_ctx_output_{get,set}_debug() -> ctx->debug_mask * nft_ctx_output_{get,set}_handle() -> ctx->output.handle * nft_ctx_output_{get,set}_echo() -> ctx->output.echo A more complicated case is include paths handling: In order to keep the API simple, remove INCLUDE_PATHS_MAX restraint and dynamically allocate nft_ctx field include_paths instead. So there is: * nft_ctx_add_include_path() -> add an include path to the list * nft_ctx_clear_include_paths() -> flush the list of include paths Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* cli: Use nft_run_cmd_from_buffer()Phil Sutter2017-10-241-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make CLI code adhere to intended libnftables API by not open coding what nft_run_cmd_from_buffer() does. This way, nft_run() has no users outside of src/libnftables.c anymore and therefore can become static. Since nft_run_cmd_from_buffer() takes care of scanner initialization and libmnl socket passed to cli_init() is present as nft_ctx field as well, signature of cli_init() can be reduced to just take nft_ctx pointer as single argument. Note that this change introduces two (possibly unwanted) side-effects: * Input descriptor passed to scanner_push_buffer() is changed from the CLI-specific one to the one used by nft_run_cmd_from_buffer(). In practice though, this doesn't make a difference: input descriptor types INDESC_CLI and INDESC_BUFFER are treated equally by erec_print(). Also, scanner_push_buffer() NULLs input descriptor name, so that is not used at all in latter code. * Error messages are printed to stderr instead of cli_nft->output. This could be fixed by introducing an 'error_output' field in nft_ctx for nft_run_cmd_from_buffer() to use when printing error messages. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* libnftables: Introduce nft_ctx_flush_cache()Phil Sutter2017-10-241-2/+7
| | | | | | | | | | | | | | | | This allows an application to explicitly flush caches associated with a given nft context, as seen in cli_complete(). Note that this is a bit inconsistent in that it releases the global interface cache, but nft_ctx_free() does the same so at least it's not a regression. Note that there is no need for explicit cache update routine since cache is populated during command execution depending on whether it is needed or not. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* libnftables: Move library stuff out of main.cPhil Sutter2017-10-241-0/+262
This creates src/libnftables.c and include/nftables/nftables.h which will become the central elements of libnftables. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>