android_kernel_xiaomi_sm8350/net/ipv4/xfrm4_policy.c
Bernhard Walle aef8811abb [XFRM]: Fix oops in xfrm4_dst_destroy()
With 2.6.21-rc1, I get an oops when running 'ifdown eth0' and an IPsec
connection is active. If I shut down the connection before running 'ifdown
eth0', then there's no problem.  The critical operation of this script is to
kill dhcpd.

The problem is probably caused by commit with git identifier
4337226228 (Linus tree) "[IPSEC]: IPv4 over IPv6
IPsec tunnel".

This patch fixes that oops. I don't know the network code of the Linux
kernel in deep, so if that fix is wrong, please change it. But please
fix the oops. :)

Signed-off-by: Bernhard Walle <bwalle@suse.de>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-26 12:10:32 -08:00

362 lines
8.4 KiB
C

/*
* xfrm4_policy.c
*
* Changes:
* Kazunori MIYAZAWA @USAGI
* YOSHIFUJI Hideaki @USAGI
* Split up af-specific portion
*
*/
#include <linux/compiler.h>
#include <linux/inetdevice.h>
#include <net/xfrm.h>
#include <net/ip.h>
static struct dst_ops xfrm4_dst_ops;
static struct xfrm_policy_afinfo xfrm4_policy_afinfo;
static int xfrm4_dst_lookup(struct xfrm_dst **dst, struct flowi *fl)
{
return __ip_route_output_key((struct rtable**)dst, fl);
}
static int xfrm4_get_saddr(xfrm_address_t *saddr, xfrm_address_t *daddr)
{
struct rtable *rt;
struct flowi fl_tunnel = {
.nl_u = {
.ip4_u = {
.daddr = daddr->a4,
},
},
};
if (!xfrm4_dst_lookup((struct xfrm_dst **)&rt, &fl_tunnel)) {
saddr->a4 = rt->rt_src;
dst_release(&rt->u.dst);
return 0;
}
return -EHOSTUNREACH;
}
static struct dst_entry *
__xfrm4_find_bundle(struct flowi *fl, struct xfrm_policy *policy)
{
struct dst_entry *dst;
read_lock_bh(&policy->lock);
for (dst = policy->bundles; dst; dst = dst->next) {
struct xfrm_dst *xdst = (struct xfrm_dst*)dst;
if (xdst->u.rt.fl.oif == fl->oif && /*XXX*/
xdst->u.rt.fl.fl4_dst == fl->fl4_dst &&
xdst->u.rt.fl.fl4_src == fl->fl4_src &&
xdst->u.rt.fl.fl4_tos == fl->fl4_tos &&
xfrm_bundle_ok(policy, xdst, fl, AF_INET, 0)) {
dst_clone(dst);
break;
}
}
read_unlock_bh(&policy->lock);
return dst;
}
/* Allocate chain of dst_entry's, attach known xfrm's, calculate
* all the metrics... Shortly, bundle a bundle.
*/
static int
__xfrm4_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int nx,
struct flowi *fl, struct dst_entry **dst_p)
{
struct dst_entry *dst, *dst_prev;
struct rtable *rt0 = (struct rtable*)(*dst_p);
struct rtable *rt = rt0;
struct flowi fl_tunnel = {
.nl_u = {
.ip4_u = {
.saddr = fl->fl4_src,
.daddr = fl->fl4_dst,
.tos = fl->fl4_tos
}
}
};
int i;
int err;
int header_len = 0;
int trailer_len = 0;
dst = dst_prev = NULL;
dst_hold(&rt->u.dst);
for (i = 0; i < nx; i++) {
struct dst_entry *dst1 = dst_alloc(&xfrm4_dst_ops);
struct xfrm_dst *xdst;
if (unlikely(dst1 == NULL)) {
err = -ENOBUFS;
dst_release(&rt->u.dst);
goto error;
}
if (!dst)
dst = dst1;
else {
dst_prev->child = dst1;
dst1->flags |= DST_NOHASH;
dst_clone(dst1);
}
xdst = (struct xfrm_dst *)dst1;
xdst->route = &rt->u.dst;
xdst->genid = xfrm[i]->genid;
dst1->next = dst_prev;
dst_prev = dst1;
header_len += xfrm[i]->props.header_len;
trailer_len += xfrm[i]->props.trailer_len;
if (xfrm[i]->props.mode == XFRM_MODE_TUNNEL) {
unsigned short encap_family = xfrm[i]->props.family;
switch(encap_family) {
case AF_INET:
fl_tunnel.fl4_dst = xfrm[i]->id.daddr.a4;
fl_tunnel.fl4_src = xfrm[i]->props.saddr.a4;
break;
#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
case AF_INET6:
ipv6_addr_copy(&fl_tunnel.fl6_dst, (struct in6_addr*)&xfrm[i]->id.daddr.a6);
ipv6_addr_copy(&fl_tunnel.fl6_src, (struct in6_addr*)&xfrm[i]->props.saddr.a6);
break;
#endif
default:
BUG_ON(1);
}
err = xfrm_dst_lookup((struct xfrm_dst **)&rt,
&fl_tunnel, encap_family);
if (err)
goto error;
} else
dst_hold(&rt->u.dst);
}
dst_prev->child = &rt->u.dst;
dst->path = &rt->u.dst;
*dst_p = dst;
dst = dst_prev;
dst_prev = *dst_p;
i = 0;
for (; dst_prev != &rt->u.dst; dst_prev = dst_prev->child) {
struct xfrm_dst *x = (struct xfrm_dst*)dst_prev;
struct xfrm_state_afinfo *afinfo;
x->u.rt.fl = *fl;
dst_prev->xfrm = xfrm[i++];
dst_prev->dev = rt->u.dst.dev;
if (rt->u.dst.dev)
dev_hold(rt->u.dst.dev);
dst_prev->obsolete = -1;
dst_prev->flags |= DST_HOST;
dst_prev->lastuse = jiffies;
dst_prev->header_len = header_len;
dst_prev->nfheader_len = 0;
dst_prev->trailer_len = trailer_len;
memcpy(&dst_prev->metrics, &x->route->metrics, sizeof(dst_prev->metrics));
/* Copy neighbout for reachability confirmation */
dst_prev->neighbour = neigh_clone(rt->u.dst.neighbour);
dst_prev->input = rt->u.dst.input;
/* XXX: When IPv6 module can be unloaded, we should manage reference
* to xfrm6_output in afinfo->output. Miyazawa
* */
afinfo = xfrm_state_get_afinfo(dst_prev->xfrm->props.family);
if (!afinfo) {
dst = *dst_p;
err = -EAFNOSUPPORT;
goto error;
}
dst_prev->output = afinfo->output;
xfrm_state_put_afinfo(afinfo);
if (dst_prev->xfrm->props.family == AF_INET && rt->peer)
atomic_inc(&rt->peer->refcnt);
x->u.rt.peer = rt->peer;
/* Sheit... I remember I did this right. Apparently,
* it was magically lost, so this code needs audit */
x->u.rt.rt_flags = rt0->rt_flags&(RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL);
x->u.rt.rt_type = rt->rt_type;
x->u.rt.rt_src = rt0->rt_src;
x->u.rt.rt_dst = rt0->rt_dst;
x->u.rt.rt_gateway = rt->rt_gateway;
x->u.rt.rt_spec_dst = rt0->rt_spec_dst;
x->u.rt.idev = rt0->idev;
in_dev_hold(rt0->idev);
header_len -= x->u.dst.xfrm->props.header_len;
trailer_len -= x->u.dst.xfrm->props.trailer_len;
}
xfrm_init_pmtu(dst);
return 0;
error:
if (dst)
dst_free(dst);
return err;
}
static void
_decode_session4(struct sk_buff *skb, struct flowi *fl)
{
struct iphdr *iph = skb->nh.iph;
u8 *xprth = skb->nh.raw + iph->ihl*4;
memset(fl, 0, sizeof(struct flowi));
if (!(iph->frag_off & htons(IP_MF | IP_OFFSET))) {
switch (iph->protocol) {
case IPPROTO_UDP:
case IPPROTO_UDPLITE:
case IPPROTO_TCP:
case IPPROTO_SCTP:
case IPPROTO_DCCP:
if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
__be16 *ports = (__be16 *)xprth;
fl->fl_ip_sport = ports[0];
fl->fl_ip_dport = ports[1];
}
break;
case IPPROTO_ICMP:
if (pskb_may_pull(skb, xprth + 2 - skb->data)) {
u8 *icmp = xprth;
fl->fl_icmp_type = icmp[0];
fl->fl_icmp_code = icmp[1];
}
break;
case IPPROTO_ESP:
if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
__be32 *ehdr = (__be32 *)xprth;
fl->fl_ipsec_spi = ehdr[0];
}
break;
case IPPROTO_AH:
if (pskb_may_pull(skb, xprth + 8 - skb->data)) {
__be32 *ah_hdr = (__be32*)xprth;
fl->fl_ipsec_spi = ah_hdr[1];
}
break;
case IPPROTO_COMP:
if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
__be16 *ipcomp_hdr = (__be16 *)xprth;
fl->fl_ipsec_spi = htonl(ntohs(ipcomp_hdr[1]));
}
break;
default:
fl->fl_ipsec_spi = 0;
break;
};
}
fl->proto = iph->protocol;
fl->fl4_dst = iph->daddr;
fl->fl4_src = iph->saddr;
fl->fl4_tos = iph->tos;
}
static inline int xfrm4_garbage_collect(void)
{
xfrm4_policy_afinfo.garbage_collect();
return (atomic_read(&xfrm4_dst_ops.entries) > xfrm4_dst_ops.gc_thresh*2);
}
static void xfrm4_update_pmtu(struct dst_entry *dst, u32 mtu)
{
struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
struct dst_entry *path = xdst->route;
path->ops->update_pmtu(path, mtu);
}
static void xfrm4_dst_destroy(struct dst_entry *dst)
{
struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
if (likely(xdst->u.rt.idev))
in_dev_put(xdst->u.rt.idev);
if (dst->xfrm && dst->xfrm->props.family == AF_INET && likely(xdst->u.rt.peer))
inet_putpeer(xdst->u.rt.peer);
xfrm_dst_destroy(xdst);
}
static void xfrm4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
int unregister)
{
struct xfrm_dst *xdst;
if (!unregister)
return;
xdst = (struct xfrm_dst *)dst;
if (xdst->u.rt.idev->dev == dev) {
struct in_device *loopback_idev = in_dev_get(&loopback_dev);
BUG_ON(!loopback_idev);
do {
in_dev_put(xdst->u.rt.idev);
xdst->u.rt.idev = loopback_idev;
in_dev_hold(loopback_idev);
xdst = (struct xfrm_dst *)xdst->u.dst.child;
} while (xdst->u.dst.xfrm);
__in_dev_put(loopback_idev);
}
xfrm_dst_ifdown(dst, dev);
}
static struct dst_ops xfrm4_dst_ops = {
.family = AF_INET,
.protocol = __constant_htons(ETH_P_IP),
.gc = xfrm4_garbage_collect,
.update_pmtu = xfrm4_update_pmtu,
.destroy = xfrm4_dst_destroy,
.ifdown = xfrm4_dst_ifdown,
.gc_thresh = 1024,
.entry_size = sizeof(struct xfrm_dst),
};
static struct xfrm_policy_afinfo xfrm4_policy_afinfo = {
.family = AF_INET,
.dst_ops = &xfrm4_dst_ops,
.dst_lookup = xfrm4_dst_lookup,
.get_saddr = xfrm4_get_saddr,
.find_bundle = __xfrm4_find_bundle,
.bundle_create = __xfrm4_bundle_create,
.decode_session = _decode_session4,
};
static void __init xfrm4_policy_init(void)
{
xfrm_policy_register_afinfo(&xfrm4_policy_afinfo);
}
static void __exit xfrm4_policy_fini(void)
{
xfrm_policy_unregister_afinfo(&xfrm4_policy_afinfo);
}
void __init xfrm4_init(void)
{
xfrm4_state_init();
xfrm4_policy_init();
}