On Fri, 16 May 2003, Mitsuru KANDA / [ISO-2022-JP] $B?@ED(B $B=<(B wrote:
> + * IP Payload Compression Protocol (IPComp) for IPv6 - RFC3713
What?!? Such RFC does not exist :-)
> + *
> + * Copyright (C)2003 USAGI/WIDE Project
> + *
> + * Author Mitsuru KANDA <mk@xxxxxxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
> + */
> +/*
> + * [Memo]
> + *
> + * Outbound:
> + * The compression of IP datagram MUST be done before AH/ESP processing,
> + * fragmentation, and the addition of Hop-by-Hop/Routing header.
> + *
> + * Inbound:
> + * The decompression of IP datagram MUST be done after the reassembly,
> + * AH/ESP processing.
> + */
> +#include <linux/config.h>
> +#include <linux/module.h>
> +#include <net/ip.h>
> +#include <net/xfrm.h>
> +#include <net/ipcomp.h>
> +#include <asm/scatterlist.h>
> +#include <linux/crypto.h>
> +#include <linux/pfkeyv2.h>
> +#include <linux/random.h>
> +#include <net/icmp.h>
> +#include <net/ipv6.h>
> +#include <linux/ipv6.h>
> +#include <linux/icmpv6.h>
> +
> +/* XXX no ipv6 ipcomp specific */
> +#define NIP6(addr) \
> + ntohs((addr).s6_addr16[0]),\
> + ntohs((addr).s6_addr16[1]),\
> + ntohs((addr).s6_addr16[2]),\
> + ntohs((addr).s6_addr16[3]),\
> + ntohs((addr).s6_addr16[4]),\
> + ntohs((addr).s6_addr16[5]),\
> + ntohs((addr).s6_addr16[6]),\
> + ntohs((addr).s6_addr16[7])
> +
> +static int ipcomp6_input(struct xfrm_state *x, struct xfrm_decap_state
> *decap, struct sk_buff *skb)
> +{
> + int err = 0;
> + u8 nexthdr = 0;
> + u8 *prevhdr;
> + int hdr_len = skb->h.raw - skb->nh.raw;
> + unsigned char *tmp_hdr = NULL;
> + struct ipv6hdr *iph;
> + int plen, dlen;
> + struct ipcomp_data *ipcd = x->data;
> + u8 *start, *scratch = ipcd->scratch;
> +
> + if ((skb_is_nonlinear(skb) || skb_cloned(skb)) &&
> + skb_linearize(skb, GFP_ATOMIC) != 0) {
> + err = -ENOMEM;
> + goto out;
> + }
> +
> + skb->ip_summed = CHECKSUM_NONE;
> +
> + /* Remove ipcomp header and decompress original payload */
> + iph = skb->nh.ipv6h;
> + tmp_hdr = kmalloc(hdr_len, GFP_ATOMIC);
> + if (!tmp_hdr)
> + goto out;
> + memcpy(tmp_hdr, iph, hdr_len);
> + nexthdr = *(u8 *)skb->data;
> + skb_pull(skb, sizeof(struct ipv6_comp_hdr));
> + skb->nh.raw += sizeof(struct ipv6_comp_hdr);
> + memcpy(skb->nh.raw, tmp_hdr, hdr_len);
> + iph = skb->nh.ipv6h;
> + iph->payload_len = htons(ntohs(iph->payload_len) - sizeof(struct
> ipv6_comp_hdr));
> + skb->h.raw = skb->data;
> +
> + /* decompression */
> + plen = skb->len;
> + dlen = IPCOMP_SCRATCH_SIZE;
> + start = skb->data;
> +
> + err = crypto_comp_decompress(ipcd->tfm, start, plen, scratch, &dlen);
> + if (err) {
> + err = -EINVAL;
> + goto out;
> + }
> +
> + if (dlen < (plen + sizeof(struct ipv6_comp_hdr))) {
> + err = -EINVAL;
> + goto out;
> + }
> +
> + err = pskb_expand_head(skb, 0, dlen - plen, GFP_ATOMIC);
> + if (err) {
> + goto out;
> + }
> +
> + skb_put(skb, dlen - plen);
> + memcpy(skb->data, scratch, dlen);
> +
> + iph = skb->nh.ipv6h;
> + iph->payload_len = htons(skb->len);
> +
> + ip6_found_nexthdr(skb, &prevhdr);
> + *prevhdr = nexthdr;
> +out:
> + if (tmp_hdr)
> + kfree(tmp_hdr);
> + if (err)
> + goto error_out;
> + return nexthdr;
> +error_out:
> + return err;
> +}
> +
> +static int ipcomp6_output(struct sk_buff *skb)
> +{
> + int err;
> + struct dst_entry *dst = skb->dst;
> + struct xfrm_state *x = dst->xfrm;
> + struct ipv6hdr *tmp_iph = NULL, *iph, *top_iph;
> + int hdr_len = 0;
> + struct ipv6_comp_hdr *ipch;
> + struct ipcomp_data *ipcd = x->data;
> + u8 *prevhdr;
> + u8 nexthdr = 0;
> + int plen, dlen;
> + u8 *start, *scratch = ipcd->scratch;
> +
> + if (skb->ip_summed == CHECKSUM_HW && skb_checksum_help(skb) == NULL) {
> + err = -EINVAL;
> + goto error_nolock;
> + }
> +
> + spin_lock_bh(&x->lock);
> +
> + err = xfrm_check_output(x, skb, AF_INET6);
> + if (err)
> + goto error;
> +
> + if (x->props.mode) {
> + hdr_len = sizeof(struct ipv6hdr);
> + nexthdr = IPPROTO_IPV6;
> + iph = skb->nh.ipv6h;
> + top_iph = (struct ipv6hdr *)skb_push(skb, sizeof(struct
> ipv6hdr));
> + top_iph->version = 6;
> + top_iph->priority = iph->priority;
> + top_iph->flow_lbl[0] = iph->flow_lbl[0];
> + top_iph->flow_lbl[1] = iph->flow_lbl[1];
> + top_iph->flow_lbl[2] = iph->flow_lbl[2];
> + top_iph->nexthdr = IPPROTO_IPV6; /* initial */
> + top_iph->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
> + top_iph->hop_limit = iph->hop_limit;
> + memcpy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr,
> sizeof(struct in6_addr));
> + memcpy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr,
> sizeof(struct in6_addr));
> + skb->nh.raw = skb->data; /* == top_iph */
> + skb->h.raw = skb->nh.raw + hdr_len;
> + } else {
> + hdr_len = ip6_found_nexthdr(skb, &prevhdr);
> + nexthdr = *prevhdr;
> + }
> +
> + /* check whether datagram len is larger than threshold */
> + if ((skb->len - hdr_len) < ipcd->threshold) {
> + goto out_ok;
> + }
> +
> + if ((skb_is_nonlinear(skb) || skb_cloned(skb)) &&
> + skb_linearize(skb, GFP_ATOMIC) != 0) {
> + err = -ENOMEM;
> + goto error;
> + }
> +
> + /* compression */
> + plen = skb->len - hdr_len;
> + dlen = IPCOMP_SCRATCH_SIZE;
> + start = skb->data + hdr_len;
> +
> + err = crypto_comp_compress(ipcd->tfm, start, plen, scratch, &dlen);
> + if (err) {
> + goto error;
> + }
> + if ((dlen + sizeof(struct ipv6_comp_hdr)) >= plen) {
> + goto out_ok;
> + }
> + memcpy(start, scratch, dlen);
> + pskb_trim(skb, hdr_len+dlen);
> +
> + /* insert ipcomp header and replace datagram */
> + tmp_iph = kmalloc(hdr_len, GFP_ATOMIC);
> + if (!tmp_iph) {
> + err = -ENOMEM;
> + goto error;
> + }
> + memcpy(tmp_iph, skb->nh.raw, hdr_len);
> + top_iph = (struct ipv6hdr*)skb_push(skb, sizeof(struct ipv6_comp_hdr));
> + memcpy(top_iph, tmp_iph, hdr_len);
> + kfree(tmp_iph);
> +
> + top_iph->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
> + skb->nh.raw = skb->data; /* top_iph */
> + ip6_found_nexthdr(skb, &prevhdr);
> + *prevhdr = IPPROTO_COMP;
> +
> + ipch = (struct ipv6_comp_hdr *)((unsigned char *)top_iph + hdr_len);
> + ipch->nexthdr = nexthdr;
> + ipch->flags = 0;
> + ipch->cpi = htons((u16 )ntohl(x->id.spi));
> +
> + skb->h.raw = (unsigned char*)ipch;
> +out_ok:
> + x->curlft.bytes += skb->len;
> + x->curlft.packets++;
> + spin_unlock_bh(&x->lock);
> +
> + if ((skb->dst = dst_pop(dst)) == NULL) {
> + err = -EHOSTUNREACH;
> + goto error_nolock;
> + }
> + err = NET_XMIT_BYPASS;
> +
> +out_exit:
> + return err;
> +error:
> + spin_unlock_bh(&x->lock);
> +error_nolock:
> + kfree_skb(skb);
> + goto out_exit;
> +}
> +
> +static void ipcomp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
> + int type, int code, int offset, __u32 info)
> +{
> + u32 spi;
> + struct ipv6hdr *iph = (struct ipv6hdr*)skb->data;
> + struct ipv6_comp_hdr *ipcomph = (struct
> ipv6_comp_hdr*)(skb->data+offset);
> + struct xfrm_state *x;
> +
> + if (type != ICMPV6_DEST_UNREACH || type != ICMPV6_PKT_TOOBIG)
> + return;
> +
> + spi = ntohl(ntohs(ipcomph->cpi));
> + x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi, IPPROTO_COMP,
> AF_INET6);
> + if (!x)
> + return;
> +
> + printk(KERN_DEBUG "pmtu discvovery on SA IPCOMP/%08x/"
> + "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
> + spi, NIP6(iph->daddr));
> + xfrm_state_put(x);
> +}
> +
> +static void ipcomp6_free_data(struct ipcomp_data *ipcd)
> +{
> + if (ipcd->tfm)
> + crypto_free_tfm(ipcd->tfm);
> + if (ipcd->scratch)
> + kfree(ipcd->scratch);
> +}
> +
> +static void ipcomp6_destroy(struct xfrm_state *x)
> +{
> + struct ipcomp_data *ipcd = x->data;
> + ipcomp6_free_data(ipcd);
> + kfree(ipcd);
> +}
> +
> +static int ipcomp6_init_state(struct xfrm_state *x, void *args)
> +{
> + int err = -ENOMEM;
> + struct ipcomp_data *ipcd;
> + struct xfrm_algo_desc *calg_desc;
> +
> + ipcd = kmalloc(sizeof(*ipcd), GFP_KERNEL);
> + if (!ipcd)
> + goto error;
> +
> + memset(ipcd, 0, sizeof(*ipcd));
> + x->props.header_len = sizeof(struct ipv6_comp_hdr);
> + if (x->props.mode)
> + x->props.header_len += sizeof(struct ipv6hdr);
> + x->data = ipcd;
> +
> + ipcd->scratch = kmalloc(IPCOMP_SCRATCH_SIZE, GFP_KERNEL);
> + if (!ipcd->scratch)
> + goto error;
> +
> + ipcd->tfm = crypto_alloc_tfm(x->calg->alg_name, 0);
> + if (!ipcd->tfm)
> + goto error;
> +
> + calg_desc = xfrm_calg_get_byname(x->calg->alg_name);
> + BUG_ON(!calg_desc);
> + ipcd->threshold = calg_desc->uinfo.comp.threshold;
> + err = 0;
> +out:
> + return err;
> +error:
> + if (ipcd) {
> + ipcomp6_free_data(ipcd);
> + kfree(ipcd);
> + }
> +
> + goto out;
> +}
> +
> +static struct xfrm_type ipcomp6_type =
> +{
> + .description = "IPCOMP6",
> + .owner = THIS_MODULE,
> + .proto = IPPROTO_COMP,
> + .init_state = ipcomp6_init_state,
> + .destructor = ipcomp6_destroy,
> + .input = ipcomp6_input,
> + .output = ipcomp6_output,
> +};
> +
> +static struct inet6_protocol ipcomp6_protocol =
> +{
> + .handler = xfrm6_rcv,
> + .err_handler = ipcomp6_err,
> + .flags = INET6_PROTO_NOPOLICY,
> +};
> +
> +static int __init ipcomp6_init(void)
> +{
> + if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) {
> + printk(KERN_INFO "ipcomp6 init: can't add xfrm type\n");
> + return -EAGAIN;
> + }
> + if (inet6_add_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) {
> + printk(KERN_INFO "ipcomp6 init: can't add protocol\n");
> + xfrm_unregister_type(&ipcomp6_type, AF_INET6);
> + return -EAGAIN;
> + }
> + return 0;
> +}
> +
> +static void __exit ipcomp6_fini(void)
> +{
> + if (inet6_del_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0)
> + printk(KERN_INFO "ipv6 ipcomp close: can't remove protocol\n");
> + if (xfrm_unregister_type(&ipcomp6_type, AF_INET6) < 0)
> + printk(KERN_INFO "ipv6 ipcomp close: can't remove xfrm type\n");
> +}
> +
> +module_init(ipcomp6_init);
> +module_exit(ipcomp6_fini);
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) for IPv6 -
> RFC3173");
> +MODULE_AUTHOR("Mitsuru KANDA <mk@xxxxxxxxxxxxxx>");
> +
> +
> Index: net/ipv6/ipv6_syms.c
> ===================================================================
> RCS file: /cvsroot/usagi/usagi-backport/linux25/net/ipv6/ipv6_syms.c,v
> retrieving revision 1.1.1.9
> retrieving revision 1.1.1.9.4.1
> diff -u -r1.1.1.9 -r1.1.1.9.4.1
> --- net/ipv6/ipv6_syms.c 6 May 2003 12:43:55 -0000 1.1.1.9
> +++ net/ipv6/ipv6_syms.c 16 May 2003 07:46:18 -0000 1.1.1.9.4.1
> @@ -35,5 +35,6 @@
> EXPORT_SYMBOL(in6addr_any);
> EXPORT_SYMBOL(in6addr_loopback);
> EXPORT_SYMBOL(in6_dev_finish_destroy);
> +EXPORT_SYMBOL(ip6_found_nexthdr);
> EXPORT_SYMBOL(xfrm6_rcv);
> EXPORT_SYMBOL(xfrm6_clear_mutable_options);
> Index: net/xfrm/xfrm_input.c
> ===================================================================
> RCS file: /cvsroot/usagi/usagi-backport/linux25/net/xfrm/xfrm_input.c,v
> retrieving revision 1.1.1.2
> retrieving revision 1.1.1.2.14.1
> diff -u -r1.1.1.2 -r1.1.1.2.14.1
> --- net/xfrm/xfrm_input.c 8 Apr 2003 08:57:59 -0000 1.1.1.2
> +++ net/xfrm/xfrm_input.c 16 May 2003 07:40:01 -0000 1.1.1.2.14.1
> @@ -34,7 +34,7 @@
> offset_seq = offsetof(struct ip_esp_hdr, seq_no);
> break;
> case IPPROTO_COMP:
> - if (!pskb_may_pull(skb, 4))
> + if (!pskb_may_pull(skb, sizeof(struct ip_comp_hdr)))
> return -EINVAL;
> *spi = ntohl(ntohs(*(u16*)(skb->h.raw + 2)));
> *seq = 0;
>
--
Pekka Savola "You each name yourselves king, yet the
Netcore Oy kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings
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