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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /net/ipv6/netfilter/ip6t_frag.c | |
download | op-kernel-dev-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip op-kernel-dev-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz |
Linux-2.6.12-rc2v2.6.12-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_frag.c')
-rw-r--r-- | net/ipv6/netfilter/ip6t_frag.c | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/net/ipv6/netfilter/ip6t_frag.c b/net/ipv6/netfilter/ip6t_frag.c new file mode 100644 index 0000000..4bfa30a --- /dev/null +++ b/net/ipv6/netfilter/ip6t_frag.c @@ -0,0 +1,229 @@ +/* Kernel module to match FRAG 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 <linux/netfilter_ipv6/ip6_tables.h> +#include <linux/netfilter_ipv6/ip6t_frag.h> + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("IPv6 FRAG match"); +MODULE_AUTHOR("Andras Kis-Szabo <kisza@sch.bme.hu>"); + +#if 0 +#define DEBUGP printk +#else +#define DEBUGP(format, args...) +#endif + +/* Returns 1 if the id is matched by the range, 0 otherwise */ +static inline int +id_match(u_int32_t min, u_int32_t max, u_int32_t id, int invert) +{ + int r=0; + DEBUGP("frag id_match:%c 0x%x <= 0x%x <= 0x%x",invert? '!':' ', + min,id,max); + r=(id >= min && id <= max) ^ invert; + DEBUGP(" result %s\n",r? "PASS" : "FAILED"); + return r; +} + +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 frag_hdr _frag, *fh = NULL; + const struct ip6t_frag *fraginfo = matchinfo; + unsigned int temp; + int len; + u8 nexthdr; + unsigned int ptr; + unsigned int hdrlen = 0; + + /* 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_frag 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); + + /* FRAG -> evaluate */ + if (nexthdr == NEXTHDR_FRAGMENT) { + temp |= MASK_FRAGMENT; + 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_frag match: unknown nextheader %u\n",nexthdr); + return 0; + break; + } + + nexthdr = hp->nexthdr; + len -= hdrlen; + ptr += hdrlen; + if ( ptr > skb->len ) { + DEBUGP("ipv6_frag: new pointer too large! \n"); + break; + } + } + + /* FRAG header not found */ + if ( temp != MASK_FRAGMENT ) return 0; + + if (len < sizeof(struct frag_hdr)){ + *hotdrop = 1; + return 0; + } + + fh = skb_header_pointer(skb, ptr, sizeof(_frag), &_frag); + BUG_ON(fh == NULL); + + DEBUGP("INFO %04X ", fh->frag_off); + DEBUGP("OFFSET %04X ", ntohs(fh->frag_off) & ~0x7); + DEBUGP("RES %02X %04X", fh->reserved, ntohs(fh->frag_off) & 0x6); + DEBUGP("MF %04X ", fh->frag_off & htons(IP6_MF)); + DEBUGP("ID %u %08X\n", ntohl(fh->identification), + ntohl(fh->identification)); + + DEBUGP("IPv6 FRAG id %02X ", + (id_match(fraginfo->ids[0], fraginfo->ids[1], + ntohl(fh->identification), + !!(fraginfo->invflags & IP6T_FRAG_INV_IDS)))); + DEBUGP("res %02X %02X%04X %02X ", + (fraginfo->flags & IP6T_FRAG_RES), fh->reserved, + ntohs(fh->frag_off) & 0x6, + !((fraginfo->flags & IP6T_FRAG_RES) + && (fh->reserved || (ntohs(fh->frag_off) & 0x06)))); + DEBUGP("first %02X %02X %02X ", + (fraginfo->flags & IP6T_FRAG_FST), + ntohs(fh->frag_off) & ~0x7, + !((fraginfo->flags & IP6T_FRAG_FST) + && (ntohs(fh->frag_off) & ~0x7))); + DEBUGP("mf %02X %02X %02X ", + (fraginfo->flags & IP6T_FRAG_MF), + ntohs(fh->frag_off) & IP6_MF, + !((fraginfo->flags & IP6T_FRAG_MF) + && !((ntohs(fh->frag_off) & IP6_MF)))); + DEBUGP("last %02X %02X %02X\n", + (fraginfo->flags & IP6T_FRAG_NMF), + ntohs(fh->frag_off) & IP6_MF, + !((fraginfo->flags & IP6T_FRAG_NMF) + && (ntohs(fh->frag_off) & IP6_MF))); + + return (fh != NULL) + && + (id_match(fraginfo->ids[0], fraginfo->ids[1], + ntohl(fh->identification), + !!(fraginfo->invflags & IP6T_FRAG_INV_IDS))) + && + !((fraginfo->flags & IP6T_FRAG_RES) + && (fh->reserved || (ntohs(fh->frag_off) & 0x6))) + && + !((fraginfo->flags & IP6T_FRAG_FST) + && (ntohs(fh->frag_off) & ~0x7)) + && + !((fraginfo->flags & IP6T_FRAG_MF) + && !(ntohs(fh->frag_off) & IP6_MF)) + && + !((fraginfo->flags & IP6T_FRAG_NMF) + && (ntohs(fh->frag_off) & IP6_MF)); +} + +/* 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_frag *fraginfo = matchinfo; + + if (matchinfosize != IP6T_ALIGN(sizeof(struct ip6t_frag))) { + DEBUGP("ip6t_frag: matchsize %u != %u\n", + matchinfosize, IP6T_ALIGN(sizeof(struct ip6t_frag))); + return 0; + } + if (fraginfo->invflags & ~IP6T_FRAG_INV_MASK) { + DEBUGP("ip6t_frag: unknown flags %X\n", + fraginfo->invflags); + return 0; + } + + return 1; +} + +static struct ip6t_match frag_match = { + .name = "frag", + .match = &match, + .checkentry = &checkentry, + .me = THIS_MODULE, +}; + +static int __init init(void) +{ + return ip6t_register_match(&frag_match); +} + +static void __exit cleanup(void) +{ + ip6t_unregister_match(&frag_match); +} + +module_init(init); +module_exit(cleanup); |