From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Sun, 7 Apr 2024 20:49:45 +0200
Subject: Adding upstream version 6.1.76.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 net/netfilter/xt_repldata.h | 48 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)
 create mode 100644 net/netfilter/xt_repldata.h

(limited to 'net/netfilter/xt_repldata.h')

diff --git a/net/netfilter/xt_repldata.h b/net/netfilter/xt_repldata.h
new file mode 100644
index 000000000..68ccbe50b
--- /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]); \
+	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; \
+})
-- 
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