From f27fc14cbd3097e98c4d3549ff93c9284134b866 Mon Sep 17 00:00:00 2001 From: Phil Sutter Date: Sat, 27 Oct 2018 12:15:50 +0200 Subject: nft.8: Document log level audit Since this pseudo log level fundamentally changes behaviour of log statement, dedicate this mode a separate paragraph. Signed-off-by: Phil Sutter Signed-off-by: Pablo Neira Ayuso --- doc/statements.txt | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/doc/statements.txt b/doc/statements.txt index 39d9f144..51dd0b37 100644 --- a/doc/statements.txt +++ b/doc/statements.txt @@ -64,16 +64,26 @@ LOG STATEMENT [verse] *log* [prefix 'quoted_string'] [level 'syslog-level'] [flags 'log-flags'] *log* group 'nflog_group' [prefix 'quoted_string'] [queue-threshold 'value'] [snaplen 'size'] +*log* level audit The log statement enables logging of matching packets. When this statement is used from a rule, the Linux kernel will print some information on all matching packets, such as header fields, via the kernel log (where it can be read with -dmesg(1) or read in the syslog). If the group number is specified, the Linux +dmesg(1) or read in the syslog). + +In the second form of invocation (if 'nflog_group' is specified), the Linux kernel will pass the packet to nfnetlink_log which will multicast the packet through a netlink socket to the specified multicast group. One or more userspace processes may subscribe to the group to receive the packets, see -libnetfilter_queue documentation for details. This is a non-terminating -statement, so the rule evaluation continues after the packet is logged. +libnetfilter_queue documentation for details. + +In the third form of invocation (if level audit is specified), the Linux +kernel writes a message into the audit buffer suitably formatted for reading +with auditd. Therefore no further formatting options (such as prefix or flags) +are allowed in this mode. + +This is a non-terminating statement, so the rule evaluation continues after +the packet is logged. .log statement options [options="header"] @@ -84,7 +94,7 @@ Log message prefix| quoted string |level| Syslog level of logging | -string: emerg, alert, crit, err, warn [default], notice, info, debug +string: emerg, alert, crit, err, warn [default], notice, info, debug, audit |group| NFLOG group to send messages to| unsigned integer (16 bit) -- cgit v1.2.3