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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /net/netfilter/xt_repldata.h | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'net/netfilter/xt_repldata.h')
-rw-r--r-- | net/netfilter/xt_repldata.h | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/net/netfilter/xt_repldata.h b/net/netfilter/xt_repldata.h new file mode 100644 index 0000000000..5d1fb7018d --- /dev/null +++ b/net/netfilter/xt_repldata.h @@ -0,0 +1,48 @@ +/* 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]); \ + strscpy_pad(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; \ +}) |