]> pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - net/ipv4/netfilter/ip_tables.c
[NETFILTER]: ip_tables: ipt and ipt_compat checks unification
[linux-2.6-omap-h63xx.git] / net / ipv4 / netfilter / ip_tables.c
index 4b90927619b80d2e0461bdd395dc7a82a68e340c..83ebbeb80b6e199b132b36b1b3373271b6ffa378 100644 (file)
@@ -401,6 +401,13 @@ mark_source_chains(struct xt_table_info *newinfo,
                            && unconditional(&e->ip)) {
                                unsigned int oldpos, size;
 
+                               if (t->verdict < -NF_MAX_VERDICT - 1) {
+                                       duprintf("mark_source_chains: bad "
+                                               "negative verdict (%i)\n",
+                                                               t->verdict);
+                                       return 0;
+                               }
+
                                /* Return: backtrack through the last
                                   big jump. */
                                do {
@@ -438,6 +445,13 @@ mark_source_chains(struct xt_table_info *newinfo,
                                if (strcmp(t->target.u.user.name,
                                           IPT_STANDARD_TARGET) == 0
                                    && newpos >= 0) {
+                                       if (newpos > newinfo->size -
+                                               sizeof(struct ipt_entry)) {
+                                               duprintf("mark_source_chains: "
+                                                       "bad verdict (%i)\n",
+                                                               newpos);
+                                               return 0;
+                                       }
                                        /* This a jump; chase it. */
                                        duprintf("Jump rule %u -> %u\n",
                                                 pos, newpos);
@@ -470,28 +484,47 @@ cleanup_match(struct ipt_entry_match *m, unsigned int *i)
 }
 
 static inline int
-standard_check(const struct ipt_entry_target *t,
-              unsigned int max_offset)
+check_entry(struct ipt_entry *e, const char *name)
 {
-       struct ipt_standard_target *targ = (void *)t;
+       struct ipt_entry_target *t;
 
-       /* Check standard info. */
-       if (targ->verdict >= 0
-           && targ->verdict > max_offset - sizeof(struct ipt_entry)) {
-               duprintf("ipt_standard_check: bad verdict (%i)\n",
-                        targ->verdict);
-               return 0;
+       if (!ip_checkentry(&e->ip)) {
+               duprintf("ip_tables: ip check failed %p %s.\n", e, name);
+               return -EINVAL;
        }
-       if (targ->verdict < -NF_MAX_VERDICT - 1) {
-               duprintf("ipt_standard_check: bad negative verdict (%i)\n",
-                        targ->verdict);
-               return 0;
+
+       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 1;
+       return ret;
 }
 
 static inline int
-check_match(struct ipt_entry_match *m,
+find_check_match(struct ipt_entry_match *m,
            const char *name,
            const struct ipt_ip *ip,
            unsigned int hookmask,
@@ -504,26 +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:
@@ -531,10 +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;
@@ -542,13 +583,13 @@ 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;
-       }
+       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;
 
@@ -558,32 +599,16 @@ check_entry(struct ipt_entry *e, const char *name, unsigned int size,
                                                     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 == &ipt_standard_target) {
-               if (!standard_check(t, size)) {
-                       ret = -EINVAL;
-                       goto err;
-               }
-       } else 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:
@@ -718,11 +743,11 @@ 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,
-                                 cleanup_entry, &i);
+                               cleanup_entry, &i);
                return ret;
        }
 
@@ -1458,10 +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;
-       }
+       ret = check_entry(e, name);
+       if (ret)
+               return ret;
 
        off = 0;
        entry_offset = (void *)e - (void *)base;
@@ -1477,7 +1501,8 @@ check_compat_entry_size_and_hooks(struct ipt_entry *e,
                                                     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;
        }
@@ -1513,36 +1538,10 @@ cleanup_matches:
 
 static inline int compat_copy_match_from_user(struct ipt_entry_match *m,
        void **dstptr, compat_uint_t *size, const char *name,
-       const struct ipt_ip *ip, unsigned int hookmask, int *i)
+       const struct ipt_ip *ip, unsigned int hookmask)
 {
-       struct ipt_entry_match *dm;
-       struct ipt_match *match;
-       int ret;
-
-       dm = (struct ipt_entry_match *)*dstptr;
-       match = m->u.kernel.match;
        xt_compat_match_from_user(m, dstptr, size);
-
-       ret = xt_check_match(match, AF_INET, dm->u.match_size - sizeof(*dm),
-                            name, hookmask, ip->proto,
-                            ip->invflags & IPT_INV_PROTO);
-       if (ret)
-               goto err;
-
-       if (m->u.kernel.match->checkentry
-           && !m->u.kernel.match->checkentry(name, ip, match, dm->data,
-                                             hookmask)) {
-               duprintf("ip_tables: check failed for `%s'.\n",
-                        m->u.kernel.match->name);
-               ret = -EINVAL;
-               goto err;
-       }
-       (*i)++;
        return 0;
-
-err:
-       module_put(m->u.kernel.match->me);
-       return ret;
 }
 
 static int compat_copy_entry_from_user(struct ipt_entry *e, void **dstptr,
@@ -1553,19 +1552,18 @@ static int compat_copy_entry_from_user(struct ipt_entry *e, void **dstptr,
        struct ipt_target *target;
        struct ipt_entry *de;
        unsigned int origsize;
-       int ret, h, j;
+       int ret, h;
 
        ret = 0;
        origsize = *size;
        de = (struct ipt_entry *)*dstptr;
        memcpy(de, e, sizeof(struct ipt_entry));
 
-       j = 0;
        *dstptr += sizeof(struct compat_ipt_entry);
        ret = IPT_MATCH_ITERATE(e, compat_copy_match_from_user, dstptr, size,
-                       name, &de->ip, de->comefrom, &j);
+                       name, &de->ip, de->comefrom);
        if (ret)
-               goto cleanup_matches;
+               return ret;
        de->target_offset = e->target_offset - (origsize - *size);
        t = ipt_get_target(e);
        target = t->u.kernel.target;
@@ -1578,34 +1576,18 @@ static int compat_copy_entry_from_user(struct ipt_entry *e, void **dstptr,
                if ((unsigned char *)de - base < newinfo->underflow[h])
                        newinfo->underflow[h] -= origsize - *size;
        }
+       return ret;
+}
 
-       t = ipt_get_target(de);
-       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)
-               goto err;
+static inline int compat_check_entry(struct ipt_entry *e, const char *name)
+{
+       int ret;
 
-       ret = -EINVAL;
-       if (t->u.kernel.target == &ipt_standard_target) {
-               if (!standard_check(t, *size))
-                       goto err;
-       } else if (t->u.kernel.target->checkentry
-                  && !t->u.kernel.target->checkentry(name, de, target,
-                                                     t->data, de->comefrom)) {
-               duprintf("ip_tables: compat: check failed for `%s'.\n",
-                        t->u.kernel.target->name);
-               goto err;
-       }
-       ret = 0;
-       return ret;
+       ret = IPT_MATCH_ITERATE(e, check_match, name, &e->ip, e->comefrom);
+       if (ret)
+               return ret;
 
-err:
-       module_put(t->u.kernel.target->me);
-cleanup_matches:
-       IPT_MATCH_ITERATE(e, cleanup_match, &j);
-       return ret;
+       return check_target(e, name);
 }
 
 static int
@@ -1618,7 +1600,7 @@ translate_compat_table(const char *name,
                unsigned int *hook_entries,
                unsigned int *underflows)
 {
-       unsigned int i;
+       unsigned int i, j;
        struct xt_table_info *newinfo, *info;
        void *pos, *entry0, *entry1;
        unsigned int size;
@@ -1636,21 +1618,21 @@ translate_compat_table(const char *name,
        }
 
        duprintf("translate_compat_table: size %u\n", info->size);
-       i = 0;
+       j = 0;
        xt_compat_lock(AF_INET);
        /* Walk through entries, checking offsets. */
        ret = IPT_ENTRY_ITERATE(entry0, total_size,
                                check_compat_entry_size_and_hooks,
                                info, &size, entry0,
                                entry0 + total_size,
-                               hook_entries, underflows, &i, name);
+                               hook_entries, underflows, &j, name);
        if (ret != 0)
                goto out_unlock;
 
        ret = -EINVAL;
-       if (i != number) {
+       if (j != number) {
                duprintf("translate_compat_table: %u not %u entries\n",
-                        i, number);
+                        j, number);
                goto out_unlock;
        }
 
@@ -1696,6 +1678,11 @@ translate_compat_table(const char *name,
        if (!mark_source_chains(newinfo, valid_hooks, entry1))
                goto free_newinfo;
 
+       ret = IPT_ENTRY_ITERATE(entry1, newinfo->size, compat_check_entry,
+                                                                       name);
+       if (ret)
+               goto free_newinfo;
+
        /* And one copy for every other CPU */
        for_each_possible_cpu(i)
                if (newinfo->entries[i] && newinfo->entries[i] != entry1)
@@ -1709,8 +1696,10 @@ translate_compat_table(const char *name,
 free_newinfo:
        xt_free_table_info(newinfo);
 out:
+       IPT_ENTRY_ITERATE(entry0, total_size, cleanup_entry, &j);
        return ret;
 out_unlock:
+       compat_flush_offsets();
        xt_compat_unlock(AF_INET);
        goto out;
 }