[PATCH net v5] net/sched: cls_flower: Reject invalid ct_state flags rules
From: <hidden>
Date: 2021-02-09 06:38:45
From: wenxu <redacted>
Reject the unsupported and invalid ct_state flags of cls flower rules.
Fixes: e0ace68af2ac ("net/sched: cls_flower: Add matching on conntrack info")
Signed-off-by: wenxu <redacted>
---
include/uapi/linux/pkt_cls.h | 2 ++
net/sched/cls_flower.c | 39 +++++++++++++++++++++++++++++++++++++--
2 files changed, 39 insertions(+), 2 deletions(-)
diff --git a/include/uapi/linux/pkt_cls.h b/include/uapi/linux/pkt_cls.h
index ee95f42..88f4bf0 100644
--- a/include/uapi/linux/pkt_cls.h
+++ b/include/uapi/linux/pkt_cls.h@@ -591,6 +591,8 @@ enum { TCA_FLOWER_KEY_CT_FLAGS_ESTABLISHED = 1 << 1, /* Part of an existing connection. */ TCA_FLOWER_KEY_CT_FLAGS_RELATED = 1 << 2, /* Related to an established connection. */ TCA_FLOWER_KEY_CT_FLAGS_TRACKED = 1 << 3, /* Conntrack has occurred. */ + + __TCA_FLOWER_KEY_CT_FLAGS_MAX, }; enum {
diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index 84f9325..46c1b3e 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c@@ -30,6 +30,11 @@ #include <uapi/linux/netfilter/nf_conntrack_common.h> +#define TCA_FLOWER_KEY_CT_FLAGS_MAX \ + ((__TCA_FLOWER_KEY_CT_FLAGS_MAX - 1) << 1) +#define TCA_FLOWER_KEY_CT_FLAGS_MASK \ + (TCA_FLOWER_KEY_CT_FLAGS_MAX - 1) + struct fl_flow_key { struct flow_dissector_key_meta meta; struct flow_dissector_key_control control;
@@ -686,8 +691,10 @@ static void *fl_get(struct tcf_proto *tp, u32 handle) [TCA_FLOWER_KEY_ENC_IP_TTL_MASK] = { .type = NLA_U8 }, [TCA_FLOWER_KEY_ENC_OPTS] = { .type = NLA_NESTED }, [TCA_FLOWER_KEY_ENC_OPTS_MASK] = { .type = NLA_NESTED }, - [TCA_FLOWER_KEY_CT_STATE] = { .type = NLA_U16 }, - [TCA_FLOWER_KEY_CT_STATE_MASK] = { .type = NLA_U16 }, + [TCA_FLOWER_KEY_CT_STATE] = + NLA_POLICY_MASK(NLA_U16, TCA_FLOWER_KEY_CT_FLAGS_MASK), + [TCA_FLOWER_KEY_CT_STATE_MASK] = + NLA_POLICY_MASK(NLA_U16, TCA_FLOWER_KEY_CT_FLAGS_MASK), [TCA_FLOWER_KEY_CT_ZONE] = { .type = NLA_U16 }, [TCA_FLOWER_KEY_CT_ZONE_MASK] = { .type = NLA_U16 }, [TCA_FLOWER_KEY_CT_MARK] = { .type = NLA_U32 },
@@ -1390,12 +1397,33 @@ static int fl_set_enc_opt(struct nlattr **tb, struct fl_flow_key *key, return 0; } +static int fl_validate_ct_state(u16 state, struct nlattr *tb, + struct netlink_ext_ack *extack) +{ + if (state && !(state & TCA_FLOWER_KEY_CT_FLAGS_TRACKED)) { + NL_SET_ERR_MSG_ATTR(extack, tb, + "no trk, so no other flag can be set"); + return -EINVAL; + } + + if (state & TCA_FLOWER_KEY_CT_FLAGS_NEW && + state & TCA_FLOWER_KEY_CT_FLAGS_ESTABLISHED) { + NL_SET_ERR_MSG_ATTR(extack, tb, + "new and est are mutually exclusive"); + return -EINVAL; + } + + return 0; +} + static int fl_set_key_ct(struct nlattr **tb, struct flow_dissector_key_ct *key, struct flow_dissector_key_ct *mask, struct netlink_ext_ack *extack) { if (tb[TCA_FLOWER_KEY_CT_STATE]) { + int err; + if (!IS_ENABLED(CONFIG_NF_CONNTRACK)) { NL_SET_ERR_MSG(extack, "Conntrack isn't enabled"); return -EOPNOTSUPP;
@@ -1403,6 +1431,13 @@ static int fl_set_key_ct(struct nlattr **tb, fl_set_key_val(tb, &key->ct_state, TCA_FLOWER_KEY_CT_STATE, &mask->ct_state, TCA_FLOWER_KEY_CT_STATE_MASK, sizeof(key->ct_state)); + + err = fl_validate_ct_state(mask->ct_state, + tb[TCA_FLOWER_KEY_CT_STATE_MASK], + extack); + if (err) + return err; + } if (tb[TCA_FLOWER_KEY_CT_ZONE]) { if (!IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES)) {
--
1.8.3.1