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author | Pablo Neira Ayuso <pablo@netfilter.org> | 2017-03-21 13:32:37 +0100 |
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committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2017-03-22 12:20:16 +0100 |
commit | 2c422257550f123049552b39f7af6e3428a60f43 (patch) | |
tree | 36178148c415c6ec1916ee5adeda4995e35510e0 /net/netfilter/nfnetlink_cthelper.c | |
parent | ae5c682113f9f94cc5e76f92cf041ee624c173ee (diff) | |
download | op-kernel-dev-2c422257550f123049552b39f7af6e3428a60f43.zip op-kernel-dev-2c422257550f123049552b39f7af6e3428a60f43.tar.gz |
netfilter: nfnl_cthelper: fix runtime expectation policy updates
We only allow runtime updates of expectation policies for timeout and
maximum number of expectations, otherwise reject the update.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Liping Zhang <zlpnobody@gmail.com>
Diffstat (limited to 'net/netfilter/nfnetlink_cthelper.c')
-rw-r--r-- | net/netfilter/nfnetlink_cthelper.c | 86 |
1 files changed, 84 insertions, 2 deletions
diff --git a/net/netfilter/nfnetlink_cthelper.c b/net/netfilter/nfnetlink_cthelper.c index 3cd41d1..90f291e 100644 --- a/net/netfilter/nfnetlink_cthelper.c +++ b/net/netfilter/nfnetlink_cthelper.c @@ -256,6 +256,89 @@ err: } static int +nfnl_cthelper_update_policy_one(const struct nf_conntrack_expect_policy *policy, + struct nf_conntrack_expect_policy *new_policy, + const struct nlattr *attr) +{ + struct nlattr *tb[NFCTH_POLICY_MAX + 1]; + int err; + + err = nla_parse_nested(tb, NFCTH_POLICY_MAX, attr, + nfnl_cthelper_expect_pol); + if (err < 0) + return err; + + if (!tb[NFCTH_POLICY_NAME] || + !tb[NFCTH_POLICY_EXPECT_MAX] || + !tb[NFCTH_POLICY_EXPECT_TIMEOUT]) + return -EINVAL; + + if (nla_strcmp(tb[NFCTH_POLICY_NAME], policy->name)) + return -EBUSY; + + new_policy->max_expected = + ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_MAX])); + new_policy->timeout = + ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_TIMEOUT])); + + return 0; +} + +static int nfnl_cthelper_update_policy_all(struct nlattr *tb[], + struct nf_conntrack_helper *helper) +{ + struct nf_conntrack_expect_policy new_policy[helper->expect_class_max + 1]; + struct nf_conntrack_expect_policy *policy; + int i, err; + + /* Check first that all policy attributes are well-formed, so we don't + * leave things in inconsistent state on errors. + */ + for (i = 0; i < helper->expect_class_max + 1; i++) { + + if (!tb[NFCTH_POLICY_SET + i]) + return -EINVAL; + + err = nfnl_cthelper_update_policy_one(&helper->expect_policy[i], + &new_policy[i], + tb[NFCTH_POLICY_SET + i]); + if (err < 0) + return err; + } + /* Now we can safely update them. */ + for (i = 0; i < helper->expect_class_max + 1; i++) { + policy = (struct nf_conntrack_expect_policy *) + &helper->expect_policy[i]; + policy->max_expected = new_policy->max_expected; + policy->timeout = new_policy->timeout; + } + + return 0; +} + +static int nfnl_cthelper_update_policy(struct nf_conntrack_helper *helper, + const struct nlattr *attr) +{ + struct nlattr *tb[NFCTH_POLICY_SET_MAX + 1]; + unsigned int class_max; + int err; + + err = nla_parse_nested(tb, NFCTH_POLICY_SET_MAX, attr, + nfnl_cthelper_expect_policy_set); + if (err < 0) + return err; + + if (!tb[NFCTH_POLICY_SET_NUM]) + return -EINVAL; + + class_max = ntohl(nla_get_be32(tb[NFCTH_POLICY_SET_NUM])); + if (helper->expect_class_max + 1 != class_max) + return -EBUSY; + + return nfnl_cthelper_update_policy_all(tb, helper); +} + +static int nfnl_cthelper_update(const struct nlattr * const tb[], struct nf_conntrack_helper *helper) { @@ -265,8 +348,7 @@ nfnl_cthelper_update(const struct nlattr * const tb[], return -EBUSY; if (tb[NFCTH_POLICY]) { - ret = nfnl_cthelper_parse_expect_policy(helper, - tb[NFCTH_POLICY]); + ret = nfnl_cthelper_update_policy(helper, tb[NFCTH_POLICY]); if (ret < 0) return ret; } |