[NETFILTER]: x_tables: simplify compat API
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / netfilter / x_tables.c
index be7baf4f6846bb3078443266831a7935136c6d4c..58522fc65d333ca163fe25e4925cfe4496ecdbc6 100644 (file)
@@ -333,52 +333,65 @@ int xt_check_match(const struct xt_match *match, unsigned short family,
 EXPORT_SYMBOL_GPL(xt_check_match);
 
 #ifdef CONFIG_COMPAT
-int xt_compat_match(void *match, void **dstptr, int *size, int convert)
+int xt_compat_match_offset(struct xt_match *match)
 {
-       struct xt_match *m;
-       struct compat_xt_entry_match *pcompat_m;
-       struct xt_entry_match *pm;
-       u_int16_t msize;
-       int off, ret;
+       u_int16_t csize = match->compatsize ? : match->matchsize;
+       return XT_ALIGN(match->matchsize) - COMPAT_XT_ALIGN(csize);
+}
+EXPORT_SYMBOL_GPL(xt_compat_match_offset);
 
-       ret = 0;
-       m = ((struct xt_entry_match *)match)->u.kernel.match;
-       off = XT_ALIGN(m->matchsize) - COMPAT_XT_ALIGN(m->matchsize);
-       switch (convert) {
-               case COMPAT_TO_USER:
-                       pm = (struct xt_entry_match *)match;
-                       msize = pm->u.user.match_size;
-                       if (copy_to_user(*dstptr, pm, msize)) {
-                               ret = -EFAULT;
-                               break;
-                       }
-                       msize -= off;
-                       if (put_user(msize, (u_int16_t *)*dstptr))
-                               ret = -EFAULT;
-                       *size -= off;
-                       *dstptr += msize;
-                       break;
-               case COMPAT_FROM_USER:
-                       pcompat_m = (struct compat_xt_entry_match *)match;
-                       pm = (struct xt_entry_match *)*dstptr;
-                       msize = pcompat_m->u.user.match_size;
-                       memcpy(pm, pcompat_m, msize);
-                       msize += off;
-                       pm->u.user.match_size = msize;
-                       *size += off;
-                       *dstptr += msize;
-                       break;
-               case COMPAT_CALC_SIZE:
-                       *size += off;
-                       break;
-               default:
-                       ret = -ENOPROTOOPT;
-                       break;
+void xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr,
+                              int *size)
+{
+       struct xt_match *match = m->u.kernel.match;
+       struct compat_xt_entry_match *cm = (struct compat_xt_entry_match *)m;
+       int pad, off = xt_compat_match_offset(match);
+       u_int16_t msize = cm->u.user.match_size;
+
+       m = *dstptr;
+       memcpy(m, cm, sizeof(*cm));
+       if (match->compat_from_user)
+               match->compat_from_user(m->data, cm->data);
+       else
+               memcpy(m->data, cm->data, msize - sizeof(*cm));
+       pad = XT_ALIGN(match->matchsize) - match->matchsize;
+       if (pad > 0)
+               memset(m->data + match->matchsize, 0, pad);
+
+       msize += off;
+       m->u.user.match_size = msize;
+
+       *size += off;
+       *dstptr += msize;
+}
+EXPORT_SYMBOL_GPL(xt_compat_match_from_user);
+
+int xt_compat_match_to_user(struct xt_entry_match *m, void __user **dstptr,
+                           int *size)
+{
+       struct xt_match *match = m->u.kernel.match;
+       struct compat_xt_entry_match __user *cm = *dstptr;
+       int off = xt_compat_match_offset(match);
+       u_int16_t msize = m->u.user.match_size - off;
+
+       if (copy_to_user(cm, m, sizeof(*cm)) ||
+           put_user(msize, &cm->u.user.match_size))
+               return -EFAULT;
+
+       if (match->compat_to_user) {
+               if (match->compat_to_user((void __user *)cm->data, m->data))
+                       return -EFAULT;
+       } else {
+               if (copy_to_user(cm->data, m->data, msize - sizeof(*cm)))
+                       return -EFAULT;
        }
-       return ret;
+
+       *size -= off;
+       *dstptr += msize;
+       return 0;
 }
-EXPORT_SYMBOL_GPL(xt_compat_match);
-#endif
+EXPORT_SYMBOL_GPL(xt_compat_match_to_user);
+#endif /* CONFIG_COMPAT */
 
 int xt_check_target(const struct xt_target *target, unsigned short family,
                    unsigned int size, const char *table, unsigned int hook_mask,
@@ -410,51 +423,64 @@ int xt_check_target(const struct xt_target *target, unsigned short family,
 EXPORT_SYMBOL_GPL(xt_check_target);
 
 #ifdef CONFIG_COMPAT
-int xt_compat_target(void *target, void **dstptr, int *size, int convert)
+int xt_compat_target_offset(struct xt_target *target)
 {
-       struct xt_target *t;
-       struct compat_xt_entry_target *pcompat;
-       struct xt_entry_target *pt;
-       u_int16_t tsize;
-       int off, ret;
+       u_int16_t csize = target->compatsize ? : target->targetsize;
+       return XT_ALIGN(target->targetsize) - COMPAT_XT_ALIGN(csize);
+}
+EXPORT_SYMBOL_GPL(xt_compat_target_offset);
 
-       ret = 0;
-       t = ((struct xt_entry_target *)target)->u.kernel.target;
-       off = XT_ALIGN(t->targetsize) - COMPAT_XT_ALIGN(t->targetsize);
-       switch (convert) {
-               case COMPAT_TO_USER:
-                       pt = (struct xt_entry_target *)target;
-                       tsize = pt->u.user.target_size;
-                       if (copy_to_user(*dstptr, pt, tsize)) {
-                               ret = -EFAULT;
-                               break;
-                       }
-                       tsize -= off;
-                       if (put_user(tsize, (u_int16_t *)*dstptr))
-                               ret = -EFAULT;
-                       *size -= off;
-                       *dstptr += tsize;
-                       break;
-               case COMPAT_FROM_USER:
-                       pcompat = (struct compat_xt_entry_target *)target;
-                       pt = (struct xt_entry_target *)*dstptr;
-                       tsize = pcompat->u.user.target_size;
-                       memcpy(pt, pcompat, tsize);
-                       tsize += off;
-                       pt->u.user.target_size = tsize;
-                       *size += off;
-                       *dstptr += tsize;
-                       break;
-               case COMPAT_CALC_SIZE:
-                       *size += off;
-                       break;
-               default:
-                       ret = -ENOPROTOOPT;
-                       break;
+void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr,
+                               int *size)
+{
+       struct xt_target *target = t->u.kernel.target;
+       struct compat_xt_entry_target *ct = (struct compat_xt_entry_target *)t;
+       int pad, off = xt_compat_target_offset(target);
+       u_int16_t tsize = ct->u.user.target_size;
+
+       t = *dstptr;
+       memcpy(t, ct, sizeof(*ct));
+       if (target->compat_from_user)
+               target->compat_from_user(t->data, ct->data);
+       else
+               memcpy(t->data, ct->data, tsize - sizeof(*ct));
+       pad = XT_ALIGN(target->targetsize) - target->targetsize;
+       if (pad > 0)
+               memset(t->data + target->targetsize, 0, pad);
+
+       tsize += off;
+       t->u.user.target_size = tsize;
+
+       *size += off;
+       *dstptr += tsize;
+}
+EXPORT_SYMBOL_GPL(xt_compat_target_from_user);
+
+int xt_compat_target_to_user(struct xt_entry_target *t, void __user **dstptr,
+                            int *size)
+{
+       struct xt_target *target = t->u.kernel.target;
+       struct compat_xt_entry_target __user *ct = *dstptr;
+       int off = xt_compat_target_offset(target);
+       u_int16_t tsize = t->u.user.target_size - off;
+
+       if (copy_to_user(ct, t, sizeof(*ct)) ||
+           put_user(tsize, &ct->u.user.target_size))
+               return -EFAULT;
+
+       if (target->compat_to_user) {
+               if (target->compat_to_user((void __user *)ct->data, t->data))
+                       return -EFAULT;
+       } else {
+               if (copy_to_user(ct->data, t->data, tsize - sizeof(*ct)))
+                       return -EFAULT;
        }
-       return ret;
+
+       *size -= off;
+       *dstptr += tsize;
+       return 0;
 }
-EXPORT_SYMBOL_GPL(xt_compat_target);
+EXPORT_SYMBOL_GPL(xt_compat_target_to_user);
 #endif
 
 struct xt_table_info *xt_alloc_table_info(unsigned int size)