netfilter: ctnetlink: refactor ctnetlink_create_expect

This patch refactors ctnetlink_create_expect by spliting it in two
chunks. As a result, we have a new function ctnetlink_alloc_expect
to allocate and to setup the expectation from ctnetlink.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index e842c0ded79db3bf4b40cf7d0661d69df35c2fdd..9aaa68bbbcdb9d5dad11316a8c58c99da5db2f1c 100644 (file)
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -2735,76 +2735,26 @@ ctnetlink_parse_expect_nat(const struct nlattr *attr,
 #endif
 }
 
-static int
-ctnetlink_create_expect(struct net *net, u16 zone,
-                       const struct nlattr * const cda[],
-                       u_int8_t u3,
-                       u32 portid, int report)
+static struct nf_conntrack_expect *
+ctnetlink_alloc_expect(const struct nlattr * const cda[], struct nf_conn *ct,
+                      struct nf_conntrack_helper *helper,
+                      struct nf_conntrack_tuple *tuple,
+                      struct nf_conntrack_tuple *mask)
 {
-       struct nf_conntrack_tuple tuple, mask, master_tuple;
-       struct nf_conntrack_tuple_hash *h = NULL;
+       u_int32_t class = 0;
        struct nf_conntrack_expect *exp;
-       struct nf_conn *ct;
        struct nf_conn_help *help;
-       struct nf_conntrack_helper *helper = NULL;
-       u_int32_t class = 0;
-       int err = 0;
-
-       /* caller guarantees that those three CTA_EXPECT_* exist */
-       err = ctnetlink_parse_tuple(cda, &tuple, CTA_EXPECT_TUPLE, u3);
-       if (err < 0)
-               return err;
-       err = ctnetlink_parse_tuple(cda, &mask, CTA_EXPECT_MASK, u3);
-       if (err < 0)
-               return err;
-       err = ctnetlink_parse_tuple(cda, &master_tuple, CTA_EXPECT_MASTER, u3);
-       if (err < 0)
-               return err;
-
-       /* Look for master conntrack of this expectation */
-       h = nf_conntrack_find_get(net, zone, &master_tuple);
-       if (!h)
-               return -ENOENT;
-       ct = nf_ct_tuplehash_to_ctrack(h);
-
-       /* Look for helper of this expectation */
-       if (cda[CTA_EXPECT_HELP_NAME]) {
-               const char *helpname = nla_data(cda[CTA_EXPECT_HELP_NAME]);
-
-               helper = __nf_conntrack_helper_find(helpname, nf_ct_l3num(ct),
-                                                   nf_ct_protonum(ct));
-               if (helper == NULL) {
-#ifdef CONFIG_MODULES
-                       if (request_module("nfct-helper-%s", helpname) < 0) {
-                               err = -EOPNOTSUPP;
-                               goto out;
-                       }
-
-                       helper = __nf_conntrack_helper_find(helpname,
-                                                           nf_ct_l3num(ct),
-                                                           nf_ct_protonum(ct));
-                       if (helper) {
-                               err = -EAGAIN;
-                               goto out;
-                       }
-#endif
-                       err = -EOPNOTSUPP;
-                       goto out;
-               }
-       }
+       int err;
 
        if (cda[CTA_EXPECT_CLASS] && helper) {
                class = ntohl(nla_get_be32(cda[CTA_EXPECT_CLASS]));
-               if (class > helper->expect_class_max) {
-                       err = -EINVAL;
-                       goto out;
-               }
+               if (class > helper->expect_class_max)
+                       return ERR_PTR(-EINVAL);
        }
        exp = nf_ct_expect_alloc(ct);
-       if (!exp) {
-               err = -ENOMEM;
-               goto out;
-       }
+       if (!exp)
+               return ERR_PTR(-ENOMEM);
+
        help = nfct_help(ct);
        if (!help) {
                if (!cda[CTA_EXPECT_TIMEOUT]) {
@@ -2842,21 +2792,89 @@ ctnetlink_create_expect(struct net *net, u16 zone,
        exp->class = class;
        exp->master = ct;
        exp->helper = helper;
-       memcpy(&exp->tuple, &tuple, sizeof(struct nf_conntrack_tuple));
-       memcpy(&exp->mask.src.u3, &mask.src.u3, sizeof(exp->mask.src.u3));
-       exp->mask.src.u.all = mask.src.u.all;
+       exp->tuple = *tuple;
+       exp->mask.src.u3 = mask->src.u3;
+       exp->mask.src.u.all = mask->src.u.all;
 
        if (cda[CTA_EXPECT_NAT]) {
                err = ctnetlink_parse_expect_nat(cda[CTA_EXPECT_NAT],
-                                                exp, u3);
+                                                exp, nf_ct_l3num(ct));
                if (err < 0)
                        goto err_out;
        }
-       err = nf_ct_expect_related_report(exp, portid, report);
+       return exp;
 err_out:
        nf_ct_expect_put(exp);
-out:
-       nf_ct_put(nf_ct_tuplehash_to_ctrack(h));
+       return ERR_PTR(err);
+}
+
+static int
+ctnetlink_create_expect(struct net *net, u16 zone,
+                       const struct nlattr * const cda[],
+                       u_int8_t u3, u32 portid, int report)
+{
+       struct nf_conntrack_tuple tuple, mask, master_tuple;
+       struct nf_conntrack_tuple_hash *h = NULL;
+       struct nf_conntrack_helper *helper = NULL;
+       struct nf_conntrack_expect *exp;
+       struct nf_conn *ct;
+       int err;
+
+       /* caller guarantees that those three CTA_EXPECT_* exist */
+       err = ctnetlink_parse_tuple(cda, &tuple, CTA_EXPECT_TUPLE, u3);
+       if (err < 0)
+               return err;
+       err = ctnetlink_parse_tuple(cda, &mask, CTA_EXPECT_MASK, u3);
+       if (err < 0)
+               return err;
+       err = ctnetlink_parse_tuple(cda, &master_tuple, CTA_EXPECT_MASTER, u3);
+       if (err < 0)
+               return err;
+
+       /* Look for master conntrack of this expectation */
+       h = nf_conntrack_find_get(net, zone, &master_tuple);
+       if (!h)
+               return -ENOENT;
+       ct = nf_ct_tuplehash_to_ctrack(h);
+
+       if (cda[CTA_EXPECT_HELP_NAME]) {
+               const char *helpname = nla_data(cda[CTA_EXPECT_HELP_NAME]);
+
+               helper = __nf_conntrack_helper_find(helpname, u3,
+                                                   nf_ct_protonum(ct));
+               if (helper == NULL) {
+#ifdef CONFIG_MODULES
+                       if (request_module("nfct-helper-%s", helpname) < 0) {
+                               err = -EOPNOTSUPP;
+                               goto err_ct;
+                       }
+                       helper = __nf_conntrack_helper_find(helpname, u3,
+                                                           nf_ct_protonum(ct));
+                       if (helper) {
+                               err = -EAGAIN;
+                               goto err_ct;
+                       }
+#endif
+                       err = -EOPNOTSUPP;
+                       goto err_ct;
+               }
+       }
+
+       exp = ctnetlink_alloc_expect(cda, ct, helper, &tuple, &mask);
+       if (IS_ERR(exp)) {
+               err = PTR_ERR(exp);
+               goto err_ct;
+       }
+
+       err = nf_ct_expect_related_report(exp, portid, report);
+       if (err < 0)
+               goto err_exp;
+
+       return 0;
+err_exp:
+       nf_ct_expect_put(exp);
+err_ct:
+       nf_ct_put(ct);
        return err;
 }