Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 211 insertions, 0 deletions

diff --git a/net/ipv6/netfilter/ip6t_hbh.c b/net/ipv6/netfilter/ip6t_hbh.c
new file mode 100644
index 000000000..e7a3fb935
--- /dev/null
+++ b/net/ipv6/netfilter/ip6t_hbh.c
@@ -0,0 +1,211 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Kernel module to match Hop-by-Hop and Destination parameters. */
+
+/* (C) 2001-2002 Andras Kis-Szabo <kisza@sch.bme.hu>
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/ipv6.h>
+#include <linux/types.h>
+#include <net/checksum.h>
+#include <net/ipv6.h>
+
+#include <asm/byteorder.h>
+
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter_ipv6/ip6_tables.h>
+#include <linux/netfilter_ipv6/ip6t_opts.h>
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Xtables: IPv6 Hop-By-Hop and Destination Header match");
+MODULE_AUTHOR("Andras Kis-Szabo <kisza@sch.bme.hu>");
+MODULE_ALIAS("ip6t_dst");
+
+/*
+ *  (Type & 0xC0) >> 6
+ *	0	-> ignorable
+ *	1	-> must drop the packet
+ *	2	-> send ICMP PARM PROB regardless and drop packet
+ *	3	-> Send ICMP if not a multicast address and drop packet
+ *  (Type & 0x20) >> 5
+ *	0	-> invariant
+ *	1	-> can change the routing
+ *  (Type & 0x1F) Type
+ *	0	-> Pad1 (only 1 byte!)
+ *	1	-> PadN LENGTH info (total length = length + 2)
+ *	C0 | 2	-> JUMBO 4 x x x x ( xxxx > 64k )
+ *	5	-> RTALERT 2 x x
+ */
+
+static struct xt_match hbh_mt6_reg[] __read_mostly;
+
+static bool
+hbh_mt6(const struct sk_buff *skb, struct xt_action_param *par)
+{
+	struct ipv6_opt_hdr _optsh;
+	const struct ipv6_opt_hdr *oh;
+	const struct ip6t_opts *optinfo = par->matchinfo;
+	unsigned int temp;
+	unsigned int ptr = 0;
+	unsigned int hdrlen = 0;
+	bool ret = false;
+	u8 _opttype;
+	u8 _optlen;
+	const u_int8_t *tp = NULL;
+	const u_int8_t *lp = NULL;
+	unsigned int optlen;
+	int err;
+
+	err = ipv6_find_hdr(skb, &ptr,
+			    (par->match == &hbh_mt6_reg[0]) ?
+			    NEXTHDR_HOP : NEXTHDR_DEST, NULL, NULL);
+	if (err < 0) {
+		if (err != -ENOENT)
+			par->hotdrop = true;
+		return false;
+	}
+
+	oh = skb_header_pointer(skb, ptr, sizeof(_optsh), &_optsh);
+	if (oh == NULL) {
+		par->hotdrop = true;
+		return false;
+	}
+
+	hdrlen = ipv6_optlen(oh);
+	if (skb->len - ptr < hdrlen) {
+		/* Packet smaller than it's length field */
+		return false;
+	}
+
+	pr_debug("IPv6 OPTS LEN %u %u ", hdrlen, oh->hdrlen);
+
+	pr_debug("len %02X %04X %02X ",
+		 optinfo->hdrlen, hdrlen,
+		 (!(optinfo->flags & IP6T_OPTS_LEN) ||
+		  ((optinfo->hdrlen == hdrlen) ^
+		   !!(optinfo->invflags & IP6T_OPTS_INV_LEN))));
+
+	ret = (!(optinfo->flags & IP6T_OPTS_LEN) ||
+	       ((optinfo->hdrlen == hdrlen) ^
+		!!(optinfo->invflags & IP6T_OPTS_INV_LEN)));
+
+	ptr += 2;
+	hdrlen -= 2;
+	if (!(optinfo->flags & IP6T_OPTS_OPTS)) {
+		return ret;
+	} else {
+		pr_debug("Strict ");
+		pr_debug("#%d ", optinfo->optsnr);
+		for (temp = 0; temp < optinfo->optsnr; temp++) {
+			/* type field exists ? */
+			if (hdrlen < 1)
+				break;
+			tp = skb_header_pointer(skb, ptr, sizeof(_opttype),
+						&_opttype);
+			if (tp == NULL)
+				break;
+
+			/* Type check */
+			if (*tp != (optinfo->opts[temp] & 0xFF00) >> 8) {
+				pr_debug("Tbad %02X %02X\n", *tp,
+					 (optinfo->opts[temp] & 0xFF00) >> 8);
+				return false;
+			} else {
+				pr_debug("Tok ");
+			}
+			/* Length check */
+			if (*tp) {
+				u16 spec_len;
+
+				/* length field exists ? */
+				if (hdrlen < 2)
+					break;
+				lp = skb_header_pointer(skb, ptr + 1,
+							sizeof(_optlen),
+							&_optlen);
+				if (lp == NULL)
+					break;
+				spec_len = optinfo->opts[temp] & 0x00FF;
+
+				if (spec_len != 0x00FF && spec_len != *lp) {
+					pr_debug("Lbad %02X %04X\n", *lp,
+						 spec_len);
+					return false;
+				}
+				pr_debug("Lok ");
+				optlen = *lp + 2;
+			} else {
+				pr_debug("Pad1\n");
+				optlen = 1;
+			}
+
+			/* Step to the next */
+			pr_debug("len%04X\n", optlen);
+
+			if ((ptr > skb->len - optlen || hdrlen < optlen) &&
+			    temp < optinfo->optsnr - 1) {
+				pr_debug("new pointer is too large!\n");
+				break;
+			}
+			ptr += optlen;
+			hdrlen -= optlen;
+		}
+		if (temp == optinfo->optsnr)
+			return ret;
+		else
+			return false;
+	}
+
+	return false;
+}
+
+static int hbh_mt6_check(const struct xt_mtchk_param *par)
+{
+	const struct ip6t_opts *optsinfo = par->matchinfo;
+
+	if (optsinfo->invflags & ~IP6T_OPTS_INV_MASK) {
+		pr_debug("unknown flags %X\n", optsinfo->invflags);
+		return -EINVAL;
+	}
+
+	if (optsinfo->flags & IP6T_OPTS_NSTRICT) {
+		pr_debug("Not strict - not implemented");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static struct xt_match hbh_mt6_reg[] __read_mostly = {
+	{
+		/* Note, hbh_mt6 relies on the order of hbh_mt6_reg */
+		.name		= "hbh",
+		.family		= NFPROTO_IPV6,
+		.match		= hbh_mt6,
+		.matchsize	= sizeof(struct ip6t_opts),
+		.checkentry	= hbh_mt6_check,
+		.me		= THIS_MODULE,
+	},
+	{
+		.name		= "dst",
+		.family		= NFPROTO_IPV6,
+		.match		= hbh_mt6,
+		.matchsize	= sizeof(struct ip6t_opts),
+		.checkentry	= hbh_mt6_check,
+		.me		= THIS_MODULE,
+	},
+};
+
+static int __init hbh_mt6_init(void)
+{
+	return xt_register_matches(hbh_mt6_reg, ARRAY_SIZE(hbh_mt6_reg));
+}
+
+static void __exit hbh_mt6_exit(void)
+{
+	xt_unregister_matches(hbh_mt6_reg, ARRAY_SIZE(hbh_mt6_reg));
+}
+
+module_init(hbh_mt6_init);
+module_exit(hbh_mt6_exit);