/* SPDX-License-Identifier: GPL-2.0 */
|
/*
|
* Today's hack: quantum tunneling in structs
|
*
|
* 'entries' and 'term' are never anywhere referenced by word in code. In fact,
|
* they serve as the hanging-off data accessed through repl.data[].
|
*/
|
|
/* tbl has the following structure equivalent, but is C99 compliant:
|
* struct {
|
* struct type##_replace repl;
|
* struct type##_standard entries[nhooks];
|
* struct type##_error term;
|
* } *tbl;
|
*/
|
|
#define xt_alloc_initial_table(type, typ2) ({ \
|
unsigned int hook_mask = info->valid_hooks; \
|
unsigned int nhooks = hweight32(hook_mask); \
|
unsigned int bytes = 0, hooknum = 0, i = 0; \
|
struct { \
|
struct type##_replace repl; \
|
struct type##_standard entries[]; \
|
} *tbl; \
|
struct type##_error *term; \
|
size_t term_offset = (offsetof(typeof(*tbl), entries[nhooks]) + \
|
__alignof__(*term) - 1) & ~(__alignof__(*term) - 1); \
|
tbl = kzalloc(term_offset + sizeof(*term), GFP_KERNEL); \
|
if (tbl == NULL) \
|
return NULL; \
|
term = (struct type##_error *)&(((char *)tbl)[term_offset]); \
|
strncpy(tbl->repl.name, info->name, sizeof(tbl->repl.name)); \
|
*term = (struct type##_error)typ2##_ERROR_INIT; \
|
tbl->repl.valid_hooks = hook_mask; \
|
tbl->repl.num_entries = nhooks + 1; \
|
tbl->repl.size = nhooks * sizeof(struct type##_standard) + \
|
sizeof(struct type##_error); \
|
for (; hook_mask != 0; hook_mask >>= 1, ++hooknum) { \
|
if (!(hook_mask & 1)) \
|
continue; \
|
tbl->repl.hook_entry[hooknum] = bytes; \
|
tbl->repl.underflow[hooknum] = bytes; \
|
tbl->entries[i++] = (struct type##_standard) \
|
typ2##_STANDARD_INIT(NF_ACCEPT); \
|
bytes += sizeof(struct type##_standard); \
|
} \
|
tbl; \
|
})
|
