[NETFILTER]: ip_tables: ipt and ipt_compat checks unification

Matches and targets verification is duplicated in normal and compat processing
ways. This patch refactors code in order to remove this.

Signed-off-by: Dmitry Mishin <dim@openvz.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 79 insertions, 97 deletions

diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 0ff2956d35e5..83ebbeb80b6e 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -484,7 +484,47 @@ cleanup_match(struct ipt_entry_match *m, unsigned int *i)
 }
 
 static inline int
-check_match(struct ipt_entry_match *m,
+check_entry(struct ipt_entry *e, const char *name)
+{
+        struct ipt_entry_target *t;
+
+        if (!ip_checkentry(&e->ip)) {
+                duprintf("ip_tables: ip check failed %p %s.\n", e, name);
+                return -EINVAL;
+        }
+
+        if (e->target_offset + sizeof(struct ipt_entry_target) > e->next_offset)
+                return -EINVAL;
+
+        t = ipt_get_target(e);
+        if (e->target_offset + t->u.target_size > e->next_offset)
+                return -EINVAL;
+
+        return 0;
+}
+
+static inline int check_match(struct ipt_entry_match *m, const char *name,
+                                const struct ipt_ip *ip, unsigned int hookmask)
+{
+        struct ipt_match *match;
+        int ret;
+
+        match = m->u.kernel.match;
+        ret = xt_check_match(match, AF_INET, m->u.match_size - sizeof(*m),
+                             name, hookmask, ip->proto,
+                             ip->invflags & IPT_INV_PROTO);
+        if (!ret && m->u.kernel.match->checkentry
+            && !m->u.kernel.match->checkentry(name, ip, match, m->data,
+                                              hookmask)) {
+                duprintf("ip_tables: check failed for `%s'.\n",
+                         m->u.kernel.match->name);
+                ret = -EINVAL;
+        }
+        return ret;
+}
+
+static inline int
+find_check_match(struct ipt_entry_match *m,
             const char *name,
             const struct ipt_ip *ip,
             unsigned int hookmask,
@@ -497,26 +537,15 @@ check_match(struct ipt_entry_match *m,
                                                    m->u.user.revision),
                                         "ipt_%s", m->u.user.name);
         if (IS_ERR(match) || !match) {
-                duprintf("check_match: `%s' not found\n", m->u.user.name);
+                duprintf("find_check_match: `%s' not found\n", m->u.user.name);
                 return match ? PTR_ERR(match) : -ENOENT;
         }
         m->u.kernel.match = match;
 
-        ret = xt_check_match(match, AF_INET, m->u.match_size - sizeof(*m),
-                             name, hookmask, ip->proto,
-                             ip->invflags & IPT_INV_PROTO);
+        ret = check_match(m, name, ip, hookmask);
         if (ret)
                 goto err;
 
-        if (m->u.kernel.match->checkentry
-            && !m->u.kernel.match->checkentry(name, ip, match, m->data,
-                                              hookmask)) {
-                duprintf("ip_tables: check failed for `%s'.\n",
-                         m->u.kernel.match->name);
-                ret = -EINVAL;
-                goto err;
-        }
-
         (*i)++;
         return 0;
 err:
@@ -524,10 +553,29 @@ err:
         return ret;
 }
 
-static struct ipt_target ipt_standard_target;
+static inline int check_target(struct ipt_entry *e, const char *name)
+{
+        struct ipt_entry_target *t;
+        struct ipt_target *target;
+        int ret;
+
+        t = ipt_get_target(e);
+        target = t->u.kernel.target;
+        ret = xt_check_target(target, AF_INET, t->u.target_size - sizeof(*t),
+                              name, e->comefrom, e->ip.proto,
+                              e->ip.invflags & IPT_INV_PROTO);
+        if (!ret && t->u.kernel.target->checkentry
+                   && !t->u.kernel.target->checkentry(name, e, target,
+                                                      t->data, e->comefrom)) {
+                duprintf("ip_tables: check failed for `%s'.\n",
+                         t->u.kernel.target->name);
+                ret = -EINVAL;
+        }
+        return ret;
+}
 
 static inline int
-check_entry(struct ipt_entry *e, const char *name, unsigned int size,
+find_check_entry(struct ipt_entry *e, const char *name, unsigned int size,
             unsigned int *i)
 {
         struct ipt_entry_target *t;
@@ -535,49 +583,32 @@ check_entry(struct ipt_entry *e, const char *name, unsigned int size,
         int ret;
         unsigned int j;
 
-        if (!ip_checkentry(&e->ip)) {
-                duprintf("ip_tables: ip check failed %p %s.\n", e, name);
-                return -EINVAL;
-        }
-
-        if (e->target_offset + sizeof(struct ipt_entry_target) > e->next_offset)
-                return -EINVAL;
+        ret = check_entry(e, name);
+        if (ret)
+                return ret;
 
         j = 0;
-        ret = IPT_MATCH_ITERATE(e, check_match, name, &e->ip, e->comefrom, &j);
+        ret = IPT_MATCH_ITERATE(e, find_check_match, name, &e->ip,
+                                                        e->comefrom, &j);
         if (ret != 0)
                 goto cleanup_matches;
 
         t = ipt_get_target(e);
-        ret = -EINVAL;
-        if (e->target_offset + t->u.target_size > e->next_offset)
-                        goto cleanup_matches;
         target = try_then_request_module(xt_find_target(AF_INET,
                                                      t->u.user.name,
                                                      t->u.user.revision),
                                          "ipt_%s", t->u.user.name);
         if (IS_ERR(target) || !target) {
-                duprintf("check_entry: `%s' not found\n", t->u.user.name);
+                duprintf("find_check_entry: `%s' not found\n", t->u.user.name);
                 ret = target ? PTR_ERR(target) : -ENOENT;
                 goto cleanup_matches;
         }
         t->u.kernel.target = target;
 
-        ret = xt_check_target(target, AF_INET, t->u.target_size - sizeof(*t),
-                              name, e->comefrom, e->ip.proto,
-                              e->ip.invflags & IPT_INV_PROTO);
+        ret = check_target(e, name);
         if (ret)
                 goto err;
 
-        if (t->u.kernel.target->checkentry
-                   && !t->u.kernel.target->checkentry(name, e, target, t->data,
-                                                      e->comefrom)) {
-                duprintf("ip_tables: check failed for `%s'.\n",
-                         t->u.kernel.target->name);
-                ret = -EINVAL;
-                goto err;
-        }
-
         (*i)++;
         return 0;
  err:
@@ -712,7 +743,7 @@ translate_table(const char *name,
         /* Finally, each sanity check must pass */
         i = 0;
         ret = IPT_ENTRY_ITERATE(entry0, newinfo->size,
-                                check_entry, name, size, &i);
+                                find_check_entry, name, size, &i);
 
         if (ret != 0) {
                 IPT_ENTRY_ITERATE(entry0, newinfo->size,
@@ -1452,14 +1483,9 @@ check_compat_entry_size_and_hooks(struct ipt_entry *e,
                 return -EINVAL;
         }
 
-        if (!ip_checkentry(&e->ip)) {
-                duprintf("ip_tables: ip check failed %p %s.\n", e, name);
-                return -EINVAL;
-        }
-
-        if (e->target_offset + sizeof(struct compat_xt_entry_target) >
-                                                                e->next_offset)
-                return -EINVAL;
+        ret = check_entry(e, name);
+        if (ret)
+                return ret;
 
         off = 0;
         entry_offset = (void *)e - (void *)base;
@@ -1470,15 +1496,13 @@ check_compat_entry_size_and_hooks(struct ipt_entry *e,
                 goto cleanup_matches;
 
         t = ipt_get_target(e);
-        ret = -EINVAL;
-        if (e->target_offset + t->u.target_size > e->next_offset)
-                        goto cleanup_matches;
         target = try_then_request_module(xt_find_target(AF_INET,
                                                      t->u.user.name,
                                                      t->u.user.revision),
                                          "ipt_%s", t->u.user.name);
         if (IS_ERR(target) || !target) {
-                duprintf("check_entry: `%s' not found\n", t->u.user.name);
+                duprintf("check_compat_entry_size_and_hooks: `%s' not found\n",
+                                                        t->u.user.name);
                 ret = target ? PTR_ERR(target) : -ENOENT;
                 goto cleanup_matches;
         }
@@ -1555,57 +1579,15 @@ static int compat_copy_entry_from_user(struct ipt_entry *e, void **dstptr,
         return ret;
 }
 
-static inline int compat_check_match(struct ipt_entry_match *m, const char *name,
-                                const struct ipt_ip *ip, unsigned int hookmask)
-{
-        struct ipt_match *match;
-        int ret;
-
-        match = m->u.kernel.match;
-        ret = xt_check_match(match, AF_INET, m->u.match_size - sizeof(*m),
-                             name, hookmask, ip->proto,
-                             ip->invflags & IPT_INV_PROTO);
-        if (!ret && m->u.kernel.match->checkentry
-            && !m->u.kernel.match->checkentry(name, ip, match, m->data,
-                                              hookmask)) {
-                duprintf("ip_tables: compat: check failed for `%s'.\n",
-                         m->u.kernel.match->name);
-                ret = -EINVAL;
-        }
-        return ret;
-}
-
-static inline int compat_check_target(struct ipt_entry *e, const char *name)
-{
-        struct ipt_entry_target *t;
-        struct ipt_target *target;
-        int ret;
-
-        t = ipt_get_target(e);
-        target = t->u.kernel.target;
-        ret = xt_check_target(target, AF_INET, t->u.target_size - sizeof(*t),
-                              name, e->comefrom, e->ip.proto,
-                              e->ip.invflags & IPT_INV_PROTO);
-        if (!ret && t->u.kernel.target->checkentry
-                   && !t->u.kernel.target->checkentry(name, e, target,
-                                                      t->data, e->comefrom)) {
-                duprintf("ip_tables: compat: check failed for `%s'.\n",
-                         t->u.kernel.target->name);
-                ret = -EINVAL;
-        }
-        return ret;
-}
-
 static inline int compat_check_entry(struct ipt_entry *e, const char *name)
 {
         int ret;
 
-        ret = IPT_MATCH_ITERATE(e, compat_check_match, name, &e->ip,
-                                                                e->comefrom);
+        ret = IPT_MATCH_ITERATE(e, check_match, name, &e->ip, e->comefrom);
         if (ret)
                 return ret;
 
-        return compat_check_target(e, name);
+        return check_target(e, name);
 }
 
 static int