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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /net/ipv6/netfilter/ip6t_dst.c
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'net/ipv6/netfilter/ip6t_dst.c')
-rw-r--r--net/ipv6/netfilter/ip6t_dst.c298
1 files changed, 298 insertions, 0 deletions
diff --git a/net/ipv6/netfilter/ip6t_dst.c b/net/ipv6/netfilter/ip6t_dst.c
new file mode 100644
index 00000000000..540925e4a7a
--- /dev/null
+++ b/net/ipv6/netfilter/ip6t_dst.c
@@ -0,0 +1,298 @@
+/* Kernel module to match Hop-by-Hop and Destination parameters. */
+
+/* (C) 2001-2002 Andras Kis-Szabo <kisza@sch.bme.hu>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#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_ipv6/ip6_tables.h>
+#include <linux/netfilter_ipv6/ip6t_opts.h>
+
+#define HOPBYHOP 0
+
+MODULE_LICENSE("GPL");
+#if HOPBYHOP
+MODULE_DESCRIPTION("IPv6 HbH match");
+#else
+MODULE_DESCRIPTION("IPv6 DST match");
+#endif
+MODULE_AUTHOR("Andras Kis-Szabo <kisza@sch.bme.hu>");
+
+#if 0
+#define DEBUGP printk
+#else
+#define DEBUGP(format, args...)
+#endif
+
+/*
+ * (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 int
+match(const struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ const void *matchinfo,
+ int offset,
+ unsigned int protoff,
+ int *hotdrop)
+{
+ struct ipv6_opt_hdr _optsh, *oh;
+ const struct ip6t_opts *optinfo = matchinfo;
+ unsigned int temp;
+ unsigned int len;
+ u8 nexthdr;
+ unsigned int ptr;
+ unsigned int hdrlen = 0;
+ unsigned int ret = 0;
+ u8 _opttype, *tp = NULL;
+ u8 _optlen, *lp = NULL;
+ unsigned int optlen;
+
+ /* type of the 1st exthdr */
+ nexthdr = skb->nh.ipv6h->nexthdr;
+ /* pointer to the 1st exthdr */
+ ptr = sizeof(struct ipv6hdr);
+ /* available length */
+ len = skb->len - ptr;
+ temp = 0;
+
+ while (ip6t_ext_hdr(nexthdr)) {
+ struct ipv6_opt_hdr _hdr, *hp;
+
+ DEBUGP("ipv6_opts header iteration \n");
+
+ /* Is there enough space for the next ext header? */
+ if (len < (int)sizeof(struct ipv6_opt_hdr))
+ return 0;
+ /* No more exthdr -> evaluate */
+ if (nexthdr == NEXTHDR_NONE) {
+ break;
+ }
+ /* ESP -> evaluate */
+ if (nexthdr == NEXTHDR_ESP) {
+ break;
+ }
+
+ hp = skb_header_pointer(skb, ptr, sizeof(_hdr), &_hdr);
+ BUG_ON(hp == NULL);
+
+ /* Calculate the header length */
+ if (nexthdr == NEXTHDR_FRAGMENT) {
+ hdrlen = 8;
+ } else if (nexthdr == NEXTHDR_AUTH)
+ hdrlen = (hp->hdrlen+2)<<2;
+ else
+ hdrlen = ipv6_optlen(hp);
+
+ /* OPTS -> evaluate */
+#if HOPBYHOP
+ if (nexthdr == NEXTHDR_HOP) {
+ temp |= MASK_HOPOPTS;
+#else
+ if (nexthdr == NEXTHDR_DEST) {
+ temp |= MASK_DSTOPTS;
+#endif
+ break;
+ }
+
+
+ /* set the flag */
+ switch (nexthdr){
+ case NEXTHDR_HOP:
+ case NEXTHDR_ROUTING:
+ case NEXTHDR_FRAGMENT:
+ case NEXTHDR_AUTH:
+ case NEXTHDR_DEST:
+ break;
+ default:
+ DEBUGP("ipv6_opts match: unknown nextheader %u\n",nexthdr);
+ return 0;
+ break;
+ }
+
+ nexthdr = hp->nexthdr;
+ len -= hdrlen;
+ ptr += hdrlen;
+ if ( ptr > skb->len ) {
+ DEBUGP("ipv6_opts: new pointer is too large! \n");
+ break;
+ }
+ }
+
+ /* OPTIONS header not found */
+#if HOPBYHOP
+ if ( temp != MASK_HOPOPTS ) return 0;
+#else
+ if ( temp != MASK_DSTOPTS ) return 0;
+#endif
+
+ if (len < (int)sizeof(struct ipv6_opt_hdr)){
+ *hotdrop = 1;
+ return 0;
+ }
+
+ if (len < hdrlen){
+ /* Packet smaller than it's length field */
+ return 0;
+ }
+
+ oh = skb_header_pointer(skb, ptr, sizeof(_optsh), &_optsh);
+ BUG_ON(oh == NULL);
+
+ DEBUGP("IPv6 OPTS LEN %u %u ", hdrlen, oh->hdrlen);
+
+ DEBUGP("len %02X %04X %02X ",
+ optinfo->hdrlen, hdrlen,
+ (!(optinfo->flags & IP6T_OPTS_LEN) ||
+ ((optinfo->hdrlen == hdrlen) ^
+ !!(optinfo->invflags & IP6T_OPTS_INV_LEN))));
+
+ ret = (oh != NULL)
+ &&
+ (!(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 if (optinfo->flags & IP6T_OPTS_NSTRICT) {
+ DEBUGP("Not strict - not implemented");
+ } else {
+ DEBUGP("Strict ");
+ DEBUGP("#%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){
+ DEBUGP("Tbad %02X %02X\n",
+ *tp,
+ (optinfo->opts[temp] & 0xFF00)>>8);
+ return 0;
+ } else {
+ DEBUGP("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) {
+ DEBUGP("Lbad %02X %04X\n", *lp,
+ spec_len);
+ return 0;
+ }
+ DEBUGP("Lok ");
+ optlen = *lp + 2;
+ } else {
+ DEBUGP("Pad1\n");
+ optlen = 1;
+ }
+
+ /* Step to the next */
+ DEBUGP("len%04X \n", optlen);
+
+ if ((ptr > skb->len - optlen || hdrlen < optlen) &&
+ (temp < optinfo->optsnr - 1)) {
+ DEBUGP("new pointer is too large! \n");
+ break;
+ }
+ ptr += optlen;
+ hdrlen -= optlen;
+ }
+ if (temp == optinfo->optsnr)
+ return ret;
+ else return 0;
+ }
+
+ return 0;
+}
+
+/* Called when user tries to insert an entry of this type. */
+static int
+checkentry(const char *tablename,
+ const struct ip6t_ip6 *ip,
+ void *matchinfo,
+ unsigned int matchinfosize,
+ unsigned int hook_mask)
+{
+ const struct ip6t_opts *optsinfo = matchinfo;
+
+ if (matchinfosize != IP6T_ALIGN(sizeof(struct ip6t_opts))) {
+ DEBUGP("ip6t_opts: matchsize %u != %u\n",
+ matchinfosize, IP6T_ALIGN(sizeof(struct ip6t_opts)));
+ return 0;
+ }
+ if (optsinfo->invflags & ~IP6T_OPTS_INV_MASK) {
+ DEBUGP("ip6t_opts: unknown flags %X\n",
+ optsinfo->invflags);
+ return 0;
+ }
+
+ return 1;
+}
+
+static struct ip6t_match opts_match = {
+#if HOPBYHOP
+ .name = "hbh",
+#else
+ .name = "dst",
+#endif
+ .match = &match,
+ .checkentry = &checkentry,
+ .me = THIS_MODULE,
+};
+
+static int __init init(void)
+{
+ return ip6t_register_match(&opts_match);
+}
+
+static void __exit cleanup(void)
+{
+ ip6t_unregister_match(&opts_match);
+}
+
+module_init(init);
+module_exit(cleanup);