diff options
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/ipv4/netfilter/arpt_mangle.c |
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/ipv4/netfilter/arpt_mangle.c')
-rw-r--r-- | net/ipv4/netfilter/arpt_mangle.c | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/net/ipv4/netfilter/arpt_mangle.c b/net/ipv4/netfilter/arpt_mangle.c new file mode 100644 index 000000000000..3e592ec86482 --- /dev/null +++ b/net/ipv4/netfilter/arpt_mangle.c @@ -0,0 +1,104 @@ +/* module that allows mangling of the arp payload */ +#include <linux/module.h> +#include <linux/netfilter_arp/arpt_mangle.h> +#include <net/sock.h> + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>"); +MODULE_DESCRIPTION("arptables arp payload mangle target"); + +static unsigned int +target(struct sk_buff **pskb, unsigned int hooknum, const struct net_device *in, + const struct net_device *out, const void *targinfo, void *userinfo) +{ + const struct arpt_mangle *mangle = targinfo; + struct arphdr *arp; + unsigned char *arpptr; + int pln, hln; + + if (skb_shared(*pskb) || skb_cloned(*pskb)) { + struct sk_buff *nskb; + + nskb = skb_copy(*pskb, GFP_ATOMIC); + if (!nskb) + return NF_DROP; + if ((*pskb)->sk) + skb_set_owner_w(nskb, (*pskb)->sk); + kfree_skb(*pskb); + *pskb = nskb; + } + + arp = (*pskb)->nh.arph; + arpptr = (*pskb)->nh.raw + sizeof(*arp); + pln = arp->ar_pln; + hln = arp->ar_hln; + /* We assume that pln and hln were checked in the match */ + if (mangle->flags & ARPT_MANGLE_SDEV) { + if (ARPT_DEV_ADDR_LEN_MAX < hln || + (arpptr + hln > (**pskb).tail)) + return NF_DROP; + memcpy(arpptr, mangle->src_devaddr, hln); + } + arpptr += hln; + if (mangle->flags & ARPT_MANGLE_SIP) { + if (ARPT_MANGLE_ADDR_LEN_MAX < pln || + (arpptr + pln > (**pskb).tail)) + return NF_DROP; + memcpy(arpptr, &mangle->u_s.src_ip, pln); + } + arpptr += pln; + if (mangle->flags & ARPT_MANGLE_TDEV) { + if (ARPT_DEV_ADDR_LEN_MAX < hln || + (arpptr + hln > (**pskb).tail)) + return NF_DROP; + memcpy(arpptr, mangle->tgt_devaddr, hln); + } + arpptr += hln; + if (mangle->flags & ARPT_MANGLE_TIP) { + if (ARPT_MANGLE_ADDR_LEN_MAX < pln || + (arpptr + pln > (**pskb).tail)) + return NF_DROP; + memcpy(arpptr, &mangle->u_t.tgt_ip, pln); + } + return mangle->target; +} + +static int +checkentry(const char *tablename, const struct arpt_entry *e, void *targinfo, + unsigned int targinfosize, unsigned int hook_mask) +{ + const struct arpt_mangle *mangle = targinfo; + + if (mangle->flags & ~ARPT_MANGLE_MASK || + !(mangle->flags & ARPT_MANGLE_MASK)) + return 0; + + if (mangle->target != NF_DROP && mangle->target != NF_ACCEPT && + mangle->target != ARPT_CONTINUE) + return 0; + return 1; +} + +static struct arpt_target arpt_mangle_reg += { + .name = "mangle", + .target = target, + .checkentry = checkentry, + .me = THIS_MODULE, +}; + +static int __init init(void) +{ + if (arpt_register_target(&arpt_mangle_reg)) + return -EINVAL; + + return 0; +} + +static void __exit fini(void) +{ + arpt_unregister_target(&arpt_mangle_reg); +} + +module_init(init); +module_exit(fini); |