The --suppl-groups option causes GIDs specified with --gid-owner to be
also checked in the supplementary groups of a process.
Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@xxxxxxxxxxx>
---
Changes from v4:
- unit tests added
Changes from v3:
- removed XTOPT_INVERT from O_SUPPL_GROUPS,
it wasn't meant to be invertable
Changes from v2:
- XT_SUPPL_GROUPS -> XT_OWNER_SUPPL_GROUPS
Changes from v1:
- complementary -> supplementary
- manual (iptables-extensions)
extensions/libxt_owner.c | 24 +++++++++++++++++-------
extensions/libxt_owner.man | 4 ++++
extensions/libxt_owner.t | 4 ++++
include/linux/netfilter/xt_owner.h | 7 ++++---
4 files changed, 29 insertions(+), 10 deletions(-)
diff --git a/extensions/libxt_owner.c b/extensions/libxt_owner.c
index 87e4df31..1702b478 100644
--- a/extensions/libxt_owner.c
+++ b/extensions/libxt_owner.c
@@ -56,6 +56,7 @@ enum {
O_PROCESS,
O_SESSION,
O_COMM,
+ O_SUPPL_GROUPS,
};
static void owner_mt_help_v0(void)
@@ -87,7 +88,8 @@ static void owner_mt_help(void)
"owner match options:\n"
"[!] --uid-owner userid[-userid] Match local UID\n"
"[!] --gid-owner groupid[-groupid] Match local GID\n"
-"[!] --socket-exists Match if socket exists\n");
+"[!] --socket-exists Match if socket exists\n"
+" --suppl-groups Also match supplementary groups set with --gid-owner\n");
}
#define s struct ipt_owner_info
@@ -131,6 +133,7 @@ static const struct xt_option_entry owner_mt_opts[] = {
.flags = XTOPT_INVERT},
{.name = "socket-exists", .id = O_SOCK_EXISTS, .type = XTTYPE_NONE,
.flags = XTOPT_INVERT},
+ {.name = "suppl-groups", .id = O_SUPPL_GROUPS, .type = XTTYPE_NONE},
XTOPT_TABLEEND,
};
@@ -275,6 +278,11 @@ static void owner_mt_parse(struct xt_option_call *cb)
info->invert |= XT_OWNER_SOCKET;
info->match |= XT_OWNER_SOCKET;
break;
+ case O_SUPPL_GROUPS:
+ if (!(info->match & XT_OWNER_GID))
+ xtables_param_act(XTF_BAD_VALUE, "owner", "--suppl-groups", "you need to use --gid-owner first");
+ info->match |= XT_OWNER_SUPPL_GROUPS;
+ break;
}
}
@@ -455,9 +463,10 @@ static void owner_mt_print(const void *ip, const struct xt_entry_match *match,
{
const struct xt_owner_match_info *info = (void *)match->data;
- owner_mt_print_item(info, "owner socket exists", XT_OWNER_SOCKET, numeric);
- owner_mt_print_item(info, "owner UID match", XT_OWNER_UID, numeric);
- owner_mt_print_item(info, "owner GID match", XT_OWNER_GID, numeric);
+ owner_mt_print_item(info, "owner socket exists", XT_OWNER_SOCKET, numeric);
+ owner_mt_print_item(info, "owner UID match", XT_OWNER_UID, numeric);
+ owner_mt_print_item(info, "owner GID match", XT_OWNER_GID, numeric);
+ owner_mt_print_item(info, "incl. suppl. groups", XT_OWNER_SUPPL_GROUPS, numeric);
}
static void
@@ -487,9 +496,10 @@ static void owner_mt_save(const void *ip, const struct xt_entry_match *match)
{
const struct xt_owner_match_info *info = (void *)match->data;
- owner_mt_print_item(info, "--socket-exists", XT_OWNER_SOCKET, true);
- owner_mt_print_item(info, "--uid-owner", XT_OWNER_UID, true);
- owner_mt_print_item(info, "--gid-owner", XT_OWNER_GID, true);
+ owner_mt_print_item(info, "--socket-exists", XT_OWNER_SOCKET, true);
+ owner_mt_print_item(info, "--uid-owner", XT_OWNER_UID, true);
+ owner_mt_print_item(info, "--gid-owner", XT_OWNER_GID, true);
+ owner_mt_print_item(info, "--suppl-groups", XT_OWNER_SUPPL_GROUPS, true);
}
static int
diff --git a/extensions/libxt_owner.man b/extensions/libxt_owner.man
index 49b58cee..e2479865 100644
--- a/extensions/libxt_owner.man
+++ b/extensions/libxt_owner.man
@@ -15,5 +15,9 @@ given user. You may also specify a numerical UID, or an UID range.
Matches if the packet socket's file structure is owned by the given group.
You may also specify a numerical GID, or a GID range.
.TP
+\fB\-\-suppl\-groups\fP
+Causes group(s) specified with \fB\-\-gid-owner\fP to be also checked in the
+supplementary groups of a process.
+.TP
[\fB!\fP] \fB\-\-socket\-exists\fP
Matches if the packet is associated with a socket.
diff --git a/extensions/libxt_owner.t b/extensions/libxt_owner.t
index aec30b65..2779e5c1 100644
--- a/extensions/libxt_owner.t
+++ b/extensions/libxt_owner.t
@@ -8,5 +8,9 @@
-m owner --uid-owner 0-10 --gid-owner 0-10;=;OK
-m owner ! --uid-owner root;-m owner ! --uid-owner 0;OK
-m owner --socket-exists;=;OK
+-m owner --gid-owner 0-10 --suppl-groups;=;OK
+-m owner --suppl-groups --gid-owner 0-10;;FAIL
+-m owner --gid-owner 0-10 ! --suppl-groups;;FAIL
+-m owner --suppl-groups;;FAIL
:INPUT
-m owner --uid-owner root;;FAIL
diff --git a/include/linux/netfilter/xt_owner.h b/include/linux/netfilter/xt_owner.h
index 20817617..e7731dcc 100644
--- a/include/linux/netfilter/xt_owner.h
+++ b/include/linux/netfilter/xt_owner.h
@@ -4,9 +4,10 @@
#include <linux/types.h>
enum {
- XT_OWNER_UID = 1 << 0,
- XT_OWNER_GID = 1 << 1,
- XT_OWNER_SOCKET = 1 << 2,
+ XT_OWNER_UID = 1 << 0,
+ XT_OWNER_GID = 1 << 1,
+ XT_OWNER_SOCKET = 1 << 2,
+ XT_OWNER_SUPPL_GROUPS = 1 << 3,
};
struct xt_owner_match_info {
--
2.20.1
