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-rw-r--r--net/sched/em_ipt.c297
1 files changed, 297 insertions, 0 deletions
diff --git a/net/sched/em_ipt.c b/net/sched/em_ipt.c
new file mode 100644
index 000000000..3650117da
--- /dev/null
+++ b/net/sched/em_ipt.c
@@ -0,0 +1,297 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * net/sched/em_ipt.c IPtables matches Ematch
+ *
+ * (c) 2018 Eyal Birger <eyal.birger@gmail.com>
+ */
+
+#include <linux/gfp.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/skbuff.h>
+#include <linux/tc_ematch/tc_em_ipt.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv6/ip6_tables.h>
+#include <net/pkt_cls.h>
+
+struct em_ipt_match {
+ const struct xt_match *match;
+ u32 hook;
+ u8 nfproto;
+ u8 match_data[] __aligned(8);
+};
+
+struct em_ipt_xt_match {
+ char *match_name;
+ int (*validate_match_data)(struct nlattr **tb, u8 mrev);
+};
+
+static const struct nla_policy em_ipt_policy[TCA_EM_IPT_MAX + 1] = {
+ [TCA_EM_IPT_MATCH_NAME] = { .type = NLA_STRING,
+ .len = XT_EXTENSION_MAXNAMELEN },
+ [TCA_EM_IPT_MATCH_REVISION] = { .type = NLA_U8 },
+ [TCA_EM_IPT_HOOK] = { .type = NLA_U32 },
+ [TCA_EM_IPT_NFPROTO] = { .type = NLA_U8 },
+ [TCA_EM_IPT_MATCH_DATA] = { .type = NLA_UNSPEC },
+};
+
+static int check_match(struct net *net, struct em_ipt_match *im, int mdata_len)
+{
+ struct xt_mtchk_param mtpar = {};
+ union {
+ struct ipt_entry e4;
+ struct ip6t_entry e6;
+ } e = {};
+
+ mtpar.net = net;
+ mtpar.table = "filter";
+ mtpar.hook_mask = 1 << im->hook;
+ mtpar.family = im->match->family;
+ mtpar.match = im->match;
+ mtpar.entryinfo = &e;
+ mtpar.matchinfo = (void *)im->match_data;
+ return xt_check_match(&mtpar, mdata_len, 0, 0);
+}
+
+static int policy_validate_match_data(struct nlattr **tb, u8 mrev)
+{
+ if (mrev != 0) {
+ pr_err("only policy match revision 0 supported");
+ return -EINVAL;
+ }
+
+ if (nla_get_u32(tb[TCA_EM_IPT_HOOK]) != NF_INET_PRE_ROUTING) {
+ pr_err("policy can only be matched on NF_INET_PRE_ROUTING");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int addrtype_validate_match_data(struct nlattr **tb, u8 mrev)
+{
+ if (mrev != 1) {
+ pr_err("only addrtype match revision 1 supported");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static const struct em_ipt_xt_match em_ipt_xt_matches[] = {
+ {
+ .match_name = "policy",
+ .validate_match_data = policy_validate_match_data
+ },
+ {
+ .match_name = "addrtype",
+ .validate_match_data = addrtype_validate_match_data
+ },
+ {}
+};
+
+static struct xt_match *get_xt_match(struct nlattr **tb)
+{
+ const struct em_ipt_xt_match *m;
+ struct nlattr *mname_attr;
+ u8 nfproto, mrev = 0;
+ int ret;
+
+ mname_attr = tb[TCA_EM_IPT_MATCH_NAME];
+ for (m = em_ipt_xt_matches; m->match_name; m++) {
+ if (!nla_strcmp(mname_attr, m->match_name))
+ break;
+ }
+
+ if (!m->match_name) {
+ pr_err("Unsupported xt match");
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (tb[TCA_EM_IPT_MATCH_REVISION])
+ mrev = nla_get_u8(tb[TCA_EM_IPT_MATCH_REVISION]);
+
+ ret = m->validate_match_data(tb, mrev);
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ nfproto = nla_get_u8(tb[TCA_EM_IPT_NFPROTO]);
+ return xt_request_find_match(nfproto, m->match_name, mrev);
+}
+
+static int em_ipt_change(struct net *net, void *data, int data_len,
+ struct tcf_ematch *em)
+{
+ struct nlattr *tb[TCA_EM_IPT_MAX + 1];
+ struct em_ipt_match *im = NULL;
+ struct xt_match *match;
+ int mdata_len, ret;
+ u8 nfproto;
+
+ ret = nla_parse_deprecated(tb, TCA_EM_IPT_MAX, data, data_len,
+ em_ipt_policy, NULL);
+ if (ret < 0)
+ return ret;
+
+ if (!tb[TCA_EM_IPT_HOOK] || !tb[TCA_EM_IPT_MATCH_NAME] ||
+ !tb[TCA_EM_IPT_MATCH_DATA] || !tb[TCA_EM_IPT_NFPROTO])
+ return -EINVAL;
+
+ nfproto = nla_get_u8(tb[TCA_EM_IPT_NFPROTO]);
+ switch (nfproto) {
+ case NFPROTO_IPV4:
+ case NFPROTO_IPV6:
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ match = get_xt_match(tb);
+ if (IS_ERR(match)) {
+ pr_err("unable to load match\n");
+ return PTR_ERR(match);
+ }
+
+ mdata_len = XT_ALIGN(nla_len(tb[TCA_EM_IPT_MATCH_DATA]));
+ im = kzalloc(sizeof(*im) + mdata_len, GFP_KERNEL);
+ if (!im) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ im->match = match;
+ im->hook = nla_get_u32(tb[TCA_EM_IPT_HOOK]);
+ im->nfproto = nfproto;
+ nla_memcpy(im->match_data, tb[TCA_EM_IPT_MATCH_DATA], mdata_len);
+
+ ret = check_match(net, im, mdata_len);
+ if (ret)
+ goto err;
+
+ em->datalen = sizeof(*im) + mdata_len;
+ em->data = (unsigned long)im;
+ return 0;
+
+err:
+ kfree(im);
+ module_put(match->me);
+ return ret;
+}
+
+static void em_ipt_destroy(struct tcf_ematch *em)
+{
+ struct em_ipt_match *im = (void *)em->data;
+
+ if (!im)
+ return;
+
+ if (im->match->destroy) {
+ struct xt_mtdtor_param par = {
+ .net = em->net,
+ .match = im->match,
+ .matchinfo = im->match_data,
+ .family = im->match->family
+ };
+ im->match->destroy(&par);
+ }
+ module_put(im->match->me);
+ kfree(im);
+}
+
+static int em_ipt_match(struct sk_buff *skb, struct tcf_ematch *em,
+ struct tcf_pkt_info *info)
+{
+ const struct em_ipt_match *im = (const void *)em->data;
+ struct xt_action_param acpar = {};
+ struct net_device *indev = NULL;
+ u8 nfproto = im->match->family;
+ struct nf_hook_state state;
+ int ret;
+
+ switch (skb_protocol(skb, true)) {
+ case htons(ETH_P_IP):
+ if (!pskb_network_may_pull(skb, sizeof(struct iphdr)))
+ return 0;
+ if (nfproto == NFPROTO_UNSPEC)
+ nfproto = NFPROTO_IPV4;
+ break;
+ case htons(ETH_P_IPV6):
+ if (!pskb_network_may_pull(skb, sizeof(struct ipv6hdr)))
+ return 0;
+ if (nfproto == NFPROTO_UNSPEC)
+ nfproto = NFPROTO_IPV6;
+ break;
+ default:
+ return 0;
+ }
+
+ rcu_read_lock();
+
+ if (skb->skb_iif)
+ indev = dev_get_by_index_rcu(em->net, skb->skb_iif);
+
+ nf_hook_state_init(&state, im->hook, nfproto,
+ indev ?: skb->dev, skb->dev, NULL, em->net, NULL);
+
+ acpar.match = im->match;
+ acpar.matchinfo = im->match_data;
+ acpar.state = &state;
+
+ ret = im->match->match(skb, &acpar);
+
+ rcu_read_unlock();
+ return ret;
+}
+
+static int em_ipt_dump(struct sk_buff *skb, struct tcf_ematch *em)
+{
+ struct em_ipt_match *im = (void *)em->data;
+
+ if (nla_put_string(skb, TCA_EM_IPT_MATCH_NAME, im->match->name) < 0)
+ return -EMSGSIZE;
+ if (nla_put_u32(skb, TCA_EM_IPT_HOOK, im->hook) < 0)
+ return -EMSGSIZE;
+ if (nla_put_u8(skb, TCA_EM_IPT_MATCH_REVISION, im->match->revision) < 0)
+ return -EMSGSIZE;
+ if (nla_put_u8(skb, TCA_EM_IPT_NFPROTO, im->nfproto) < 0)
+ return -EMSGSIZE;
+ if (nla_put(skb, TCA_EM_IPT_MATCH_DATA,
+ im->match->usersize ?: im->match->matchsize,
+ im->match_data) < 0)
+ return -EMSGSIZE;
+
+ return 0;
+}
+
+static struct tcf_ematch_ops em_ipt_ops = {
+ .kind = TCF_EM_IPT,
+ .change = em_ipt_change,
+ .destroy = em_ipt_destroy,
+ .match = em_ipt_match,
+ .dump = em_ipt_dump,
+ .owner = THIS_MODULE,
+ .link = LIST_HEAD_INIT(em_ipt_ops.link)
+};
+
+static int __init init_em_ipt(void)
+{
+ return tcf_em_register(&em_ipt_ops);
+}
+
+static void __exit exit_em_ipt(void)
+{
+ tcf_em_unregister(&em_ipt_ops);
+}
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Eyal Birger <eyal.birger@gmail.com>");
+MODULE_DESCRIPTION("TC extended match for IPtables matches");
+
+module_init(init_em_ipt);
+module_exit(exit_em_ipt);
+
+MODULE_ALIAS_TCF_EMATCH(TCF_EM_IPT);
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