| Message ID | 20151117194221.GB22864@mtj.duckdns.org |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
On Tuesday 2015-11-17 20:42, Tejun Heo wrote: >+static void cgroup2_save(const void *ip, const struct xt_entry_match *match) >+{ >+ const struct xt_cgroup2_info *info = (void *)match->data; >+ >+ printf("%s --path %s", info->invert ? " !" : "", info->path); >+} Can cgroup path names contain anything fancy, like spaces, backslashes, etc.? If so, xtables_save_string() will be needed here. >+static struct xtables_match cgroup2_match = { >+ .family = NFPROTO_UNSPEC, >+ .name = "cgroup2", >+ .version = XTABLES_VERSION, >+ .size = XT_ALIGN(sizeof(struct xt_cgroup2_info)), >+ .userspacesize = XT_ALIGN(sizeof(struct xt_cgroup2_info)), userspacesize must not include xt_cgroup2_info.priv. Change to offsetof(...), cf. other .c modules which do this. >+++ b/extensions/libxt_cgroup2.man >@@ -0,0 +1,24 @@ >+.TP >+[\fB!\fP] \fB\-\-path\fP \fIpath\fP >+Match cgroup2 membership. >+ >+Each socket is associated with the v2 cgroup of the creating process. >+This matches packets coming from or going to all sockets in the >+sub-hierarchy of the specified path. The path should be relative to >+the root of the cgroup2 hierarchy. Can be used in the OUTPUT and >+INPUT chains to assign particular firewall policies for aggregated >+processes on the system. This allows for more fine-grained firewall >+policies that only match for a subset of the system's processes. >+ >+\fBIMPORTANT\fP: when being used in the INPUT chain, the cgroup2 >+matcher is currently only of limited functionality, meaning it >+will only match on packets that are processed for local sockets >+through early socket demuxing. Therefore, general usage on the >+INPUT chain is disadviced unless the implications are well is disadviced (sic) -> is not advised -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hello, On Wed, Nov 18, 2015 at 12:02:01AM +0100, Jan Engelhardt wrote: > On Tuesday 2015-11-17 20:42, Tejun Heo wrote: > >+static void cgroup2_save(const void *ip, const struct xt_entry_match *match) > >+{ > >+ const struct xt_cgroup2_info *info = (void *)match->data; > >+ > >+ printf("%s --path %s", info->invert ? " !" : "", info->path); > >+} > > Can cgroup path names contain anything fancy, like spaces, backslashes, etc.? > If so, xtables_save_string() will be needed here. Will update. > >+static struct xtables_match cgroup2_match = { > >+ .family = NFPROTO_UNSPEC, > >+ .name = "cgroup2", > >+ .version = XTABLES_VERSION, > >+ .size = XT_ALIGN(sizeof(struct xt_cgroup2_info)), > >+ .userspacesize = XT_ALIGN(sizeof(struct xt_cgroup2_info)), > > userspacesize must not include xt_cgroup2_info.priv. > Change to offsetof(...), cf. other .c modules which do this. Ah, okay. ... > >+\fBIMPORTANT\fP: when being used in the INPUT chain, the cgroup2 > >+matcher is currently only of limited functionality, meaning it > >+will only match on packets that are processed for local sockets > >+through early socket demuxing. Therefore, general usage on the > >+INPUT chain is disadviced unless the implications are well > > is disadviced (sic) -> is not advised Will update. That's copied verbatim from xt_cgroup tho. Will create a patch to update that too. Thanks.
--- /dev/null +++ b/extensions/libxt_cgroup2.c @@ -0,0 +1,70 @@ +#include <stdio.h> +#include <mntent.h> +#include <xtables.h> +#include <linux/netfilter/xt_cgroup2.h> +#include <linux/limits.h> + +enum { + O_CGROUP2_PATH, +}; + +static void cgroup2_help(void) +{ + printf( +"cgroup2 match options:\n" +"[!] --path path path relative to cgroup2 root, recursive match\n"); +} + +static const struct xt_option_entry cgroup2_opts[] = { + { + .name = "path", + .id = O_CGROUP2_PATH, + .type = XTTYPE_STRING, + .flags = XTOPT_INVERT | XTOPT_MAND | XTOPT_PUT, + XTOPT_POINTER(struct xt_cgroup2_info, path) + }, + XTOPT_TABLEEND, +}; + +static void cgroup2_parse(struct xt_option_call *cb) +{ + struct xt_cgroup2_info *info = cb->data; + + xtables_option_parse(cb); + + if (cb->invert) + info->invert = true; +} + +static void cgroup2_print(const void *ip, const struct xt_entry_match *match, + int numeric) +{ + const struct xt_cgroup2_info *info = (void *)match->data; + + printf(" cgroup2 %s%s", info->invert ? "! ":"", info->path); +} + +static void cgroup2_save(const void *ip, const struct xt_entry_match *match) +{ + const struct xt_cgroup2_info *info = (void *)match->data; + + printf("%s --path %s", info->invert ? " !" : "", info->path); +} + +static struct xtables_match cgroup2_match = { + .family = NFPROTO_UNSPEC, + .name = "cgroup2", + .version = XTABLES_VERSION, + .size = XT_ALIGN(sizeof(struct xt_cgroup2_info)), + .userspacesize = XT_ALIGN(sizeof(struct xt_cgroup2_info)), + .help = cgroup2_help, + .print = cgroup2_print, + .save = cgroup2_save, + .x6_parse = cgroup2_parse, + .x6_options = cgroup2_opts, +}; + +void _init(void) +{ + xtables_register_match(&cgroup2_match); +} --- /dev/null +++ b/extensions/libxt_cgroup2.man @@ -0,0 +1,24 @@ +.TP +[\fB!\fP] \fB\-\-path\fP \fIpath\fP +Match cgroup2 membership. + +Each socket is associated with the v2 cgroup of the creating process. +This matches packets coming from or going to all sockets in the +sub-hierarchy of the specified path. The path should be relative to +the root of the cgroup2 hierarchy. Can be used in the OUTPUT and +INPUT chains to assign particular firewall policies for aggregated +processes on the system. This allows for more fine-grained firewall +policies that only match for a subset of the system's processes. + +\fBIMPORTANT\fP: when being used in the INPUT chain, the cgroup2 +matcher is currently only of limited functionality, meaning it +will only match on packets that are processed for local sockets +through early socket demuxing. Therefore, general usage on the +INPUT chain is disadviced unless the implications are well +understood. +.PP +Example: +.IP +iptables \-A OUTPUT \-p tcp \-\-sport 80 \-m cgroup2 ! \-\-path service/http-server \-j DROP +.PP +Available since Linux 4.5. --- /dev/null +++ b/include/linux/netfilter/xt_cgroup2.h @@ -0,0 +1,14 @@ +#ifndef _XT_CGROUP2_H +#define _XT_CGROUP2_H + +#include <linux/types.h> + +struct xt_cgroup2_info { + char path[PATH_MAX]; + __u8 invert; + + /* kernel internal data */ + void *priv; +}; + +#endif /* _XT_CGROUP2_H */
This patch adds the extension for the xt_cgroup2 which matches packets based on the v2 cgroup path of the associated socket. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Daniel Borkmann <dborkman@redhat.com> --- extensions/libxt_cgroup2.c | 70 +++++++++++++++++++++++++++++++++++ extensions/libxt_cgroup2.man | 24 ++++++++++++ include/linux/netfilter/xt_cgroup2.h | 14 +++++++ 3 files changed, 108 insertions(+) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html