linux/net/ipv6/xfrm6_state.c
Steffen Klassert 43a4dea4c9 xfrm: Assign the inner mode output function to the dst entry
As it is, we assign the outer modes output function to the dst entry
when we create the xfrm bundle. This leads to two problems on interfamily
scenarios. We might insert ipv4 packets into ip6_fragment when called
from xfrm6_output. The system crashes if we try to fragment an ipv4
packet with ip6_fragment. This issue was introduced with git commit
ad0081e4 (ipv6: Fragment locally generated tunnel-mode IPSec6 packets
as needed). The second issue is, that we might insert ipv4 packets in
netfilter6 and vice versa on interfamily scenarios.

With this patch we assign the inner mode output function to the dst entry
when we create the xfrm bundle. So xfrm4_output/xfrm6_output from the inner
mode is used and the right fragmentation and netfilter functions are called.
We switch then to outer mode with the output_finish functions.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-10 15:03:34 -07:00

196 lines
4.6 KiB
C

/*
* xfrm6_state.c: based on xfrm4_state.c
*
* Authors:
* Mitsuru KANDA @USAGI
* Kazunori MIYAZAWA @USAGI
* Kunihiro Ishiguro <kunihiro@ipinfusion.com>
* IPv6 support
* YOSHIFUJI Hideaki @USAGI
* Split up af-specific portion
*
*/
#include <net/xfrm.h>
#include <linux/pfkeyv2.h>
#include <linux/ipsec.h>
#include <linux/netfilter_ipv6.h>
#include <net/dsfield.h>
#include <net/ipv6.h>
#include <net/addrconf.h>
static void
__xfrm6_init_tempsel(struct xfrm_selector *sel, const struct flowi *fl)
{
const struct flowi6 *fl6 = &fl->u.ip6;
/* Initialize temporary selector matching only
* to current session. */
ipv6_addr_copy((struct in6_addr *)&sel->daddr, &fl6->daddr);
ipv6_addr_copy((struct in6_addr *)&sel->saddr, &fl6->saddr);
sel->dport = xfrm_flowi_dport(fl, &fl6->uli);
sel->dport_mask = htons(0xffff);
sel->sport = xfrm_flowi_sport(fl, &fl6->uli);
sel->sport_mask = htons(0xffff);
sel->family = AF_INET6;
sel->prefixlen_d = 128;
sel->prefixlen_s = 128;
sel->proto = fl6->flowi6_proto;
sel->ifindex = fl6->flowi6_oif;
}
static void
xfrm6_init_temprop(struct xfrm_state *x, const struct xfrm_tmpl *tmpl,
const xfrm_address_t *daddr, const xfrm_address_t *saddr)
{
x->id = tmpl->id;
if (ipv6_addr_any((struct in6_addr*)&x->id.daddr))
memcpy(&x->id.daddr, daddr, sizeof(x->sel.daddr));
memcpy(&x->props.saddr, &tmpl->saddr, sizeof(x->props.saddr));
if (ipv6_addr_any((struct in6_addr*)&x->props.saddr))
memcpy(&x->props.saddr, saddr, sizeof(x->props.saddr));
x->props.mode = tmpl->mode;
x->props.reqid = tmpl->reqid;
x->props.family = AF_INET6;
}
/* distribution counting sort function for xfrm_state and xfrm_tmpl */
static int
__xfrm6_sort(void **dst, void **src, int n, int (*cmp)(void *p), int maxclass)
{
int i;
int class[XFRM_MAX_DEPTH];
int count[maxclass];
memset(count, 0, sizeof(count));
for (i = 0; i < n; i++) {
int c;
class[i] = c = cmp(src[i]);
count[c]++;
}
for (i = 2; i < maxclass; i++)
count[i] += count[i - 1];
for (i = 0; i < n; i++) {
dst[count[class[i] - 1]++] = src[i];
src[i] = NULL;
}
return 0;
}
/*
* Rule for xfrm_state:
*
* rule 1: select IPsec transport except AH
* rule 2: select MIPv6 RO or inbound trigger
* rule 3: select IPsec transport AH
* rule 4: select IPsec tunnel
* rule 5: others
*/
static int __xfrm6_state_sort_cmp(void *p)
{
struct xfrm_state *v = p;
switch (v->props.mode) {
case XFRM_MODE_TRANSPORT:
if (v->id.proto != IPPROTO_AH)
return 1;
else
return 3;
#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
case XFRM_MODE_ROUTEOPTIMIZATION:
case XFRM_MODE_IN_TRIGGER:
return 2;
#endif
case XFRM_MODE_TUNNEL:
case XFRM_MODE_BEET:
return 4;
}
return 5;
}
static int
__xfrm6_state_sort(struct xfrm_state **dst, struct xfrm_state **src, int n)
{
return __xfrm6_sort((void **)dst, (void **)src, n,
__xfrm6_state_sort_cmp, 6);
}
/*
* Rule for xfrm_tmpl:
*
* rule 1: select IPsec transport
* rule 2: select MIPv6 RO or inbound trigger
* rule 3: select IPsec tunnel
* rule 4: others
*/
static int __xfrm6_tmpl_sort_cmp(void *p)
{
struct xfrm_tmpl *v = p;
switch (v->mode) {
case XFRM_MODE_TRANSPORT:
return 1;
#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
case XFRM_MODE_ROUTEOPTIMIZATION:
case XFRM_MODE_IN_TRIGGER:
return 2;
#endif
case XFRM_MODE_TUNNEL:
case XFRM_MODE_BEET:
return 3;
}
return 4;
}
static int
__xfrm6_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n)
{
return __xfrm6_sort((void **)dst, (void **)src, n,
__xfrm6_tmpl_sort_cmp, 5);
}
int xfrm6_extract_header(struct sk_buff *skb)
{
struct ipv6hdr *iph = ipv6_hdr(skb);
XFRM_MODE_SKB_CB(skb)->ihl = sizeof(*iph);
XFRM_MODE_SKB_CB(skb)->id = 0;
XFRM_MODE_SKB_CB(skb)->frag_off = htons(IP_DF);
XFRM_MODE_SKB_CB(skb)->tos = ipv6_get_dsfield(iph);
XFRM_MODE_SKB_CB(skb)->ttl = iph->hop_limit;
XFRM_MODE_SKB_CB(skb)->optlen = 0;
memcpy(XFRM_MODE_SKB_CB(skb)->flow_lbl, iph->flow_lbl,
sizeof(XFRM_MODE_SKB_CB(skb)->flow_lbl));
return 0;
}
static struct xfrm_state_afinfo xfrm6_state_afinfo = {
.family = AF_INET6,
.proto = IPPROTO_IPV6,
.eth_proto = htons(ETH_P_IPV6),
.owner = THIS_MODULE,
.init_tempsel = __xfrm6_init_tempsel,
.init_temprop = xfrm6_init_temprop,
.tmpl_sort = __xfrm6_tmpl_sort,
.state_sort = __xfrm6_state_sort,
.output = xfrm6_output,
.output_finish = xfrm6_output_finish,
.extract_input = xfrm6_extract_input,
.extract_output = xfrm6_extract_output,
.transport_finish = xfrm6_transport_finish,
};
int __init xfrm6_state_init(void)
{
return xfrm_state_register_afinfo(&xfrm6_state_afinfo);
}
void xfrm6_state_fini(void)
{
xfrm_state_unregister_afinfo(&xfrm6_state_afinfo);
}