android_kernel_xiaomi_sm8350/net/ipv4/xfrm4_state.c
Herbert Xu 546be2405b [IPSEC] xfrm: Undo afinfo lock proliferation
The number of locks used to manage afinfo structures can easily be reduced
down to one each for policy and state respectively.  This is based on the
observation that the write locks are only held by module insertion/removal
which are very rare events so there is no need to further differentiate
between the insertion of modules like ipv6 versus esp6.

The removal of the read locks in xfrm4_policy.c/xfrm6_policy.c might look
suspicious at first.  However, after you realise that nobody ever takes
the corresponding write lock you'll feel better :)

As far as I can gather it's an attempt to guard against the removal of
the corresponding modules.  Since neither module can be unloaded at all
we can leave it to whoever fixes up IPv6 unloading :)

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:28:37 -07:00

152 lines
3.6 KiB
C

/*
* xfrm4_state.c
*
* Changes:
* YOSHIFUJI Hideaki @USAGI
* Split up af-specific portion
*
*/
#include <net/ip.h>
#include <net/xfrm.h>
#include <linux/pfkeyv2.h>
#include <linux/ipsec.h>
static struct xfrm_state_afinfo xfrm4_state_afinfo;
static int xfrm4_init_flags(struct xfrm_state *x)
{
if (ipv4_config.no_pmtu_disc)
x->props.flags |= XFRM_STATE_NOPMTUDISC;
return 0;
}
static void
__xfrm4_init_tempsel(struct xfrm_state *x, struct flowi *fl,
struct xfrm_tmpl *tmpl,
xfrm_address_t *daddr, xfrm_address_t *saddr)
{
x->sel.daddr.a4 = fl->fl4_dst;
x->sel.saddr.a4 = fl->fl4_src;
x->sel.dport = xfrm_flowi_dport(fl);
x->sel.dport_mask = ~0;
x->sel.sport = xfrm_flowi_sport(fl);
x->sel.sport_mask = ~0;
x->sel.prefixlen_d = 32;
x->sel.prefixlen_s = 32;
x->sel.proto = fl->proto;
x->sel.ifindex = fl->oif;
x->id = tmpl->id;
if (x->id.daddr.a4 == 0)
x->id.daddr.a4 = daddr->a4;
x->props.saddr = tmpl->saddr;
if (x->props.saddr.a4 == 0)
x->props.saddr.a4 = saddr->a4;
if (tmpl->mode && x->props.saddr.a4 == 0) {
struct rtable *rt;
struct flowi fl_tunnel = {
.nl_u = {
.ip4_u = {
.daddr = x->id.daddr.a4,
}
}
};
if (!xfrm_dst_lookup((struct xfrm_dst **)&rt,
&fl_tunnel, AF_INET)) {
x->props.saddr.a4 = rt->rt_src;
dst_release(&rt->u.dst);
}
}
x->props.mode = tmpl->mode;
x->props.reqid = tmpl->reqid;
x->props.family = AF_INET;
}
static struct xfrm_state *
__xfrm4_state_lookup(xfrm_address_t *daddr, u32 spi, u8 proto)
{
unsigned h = __xfrm4_spi_hash(daddr, spi, proto);
struct xfrm_state *x;
list_for_each_entry(x, xfrm4_state_afinfo.state_byspi+h, byspi) {
if (x->props.family == AF_INET &&
spi == x->id.spi &&
daddr->a4 == x->id.daddr.a4 &&
proto == x->id.proto) {
xfrm_state_hold(x);
return x;
}
}
return NULL;
}
static struct xfrm_state *
__xfrm4_find_acq(u8 mode, u32 reqid, u8 proto,
xfrm_address_t *daddr, xfrm_address_t *saddr,
int create)
{
struct xfrm_state *x, *x0;
unsigned h = __xfrm4_dst_hash(daddr);
x0 = NULL;
list_for_each_entry(x, xfrm4_state_afinfo.state_bydst+h, bydst) {
if (x->props.family == AF_INET &&
daddr->a4 == x->id.daddr.a4 &&
mode == x->props.mode &&
proto == x->id.proto &&
saddr->a4 == x->props.saddr.a4 &&
reqid == x->props.reqid &&
x->km.state == XFRM_STATE_ACQ &&
!x->id.spi) {
x0 = x;
break;
}
}
if (!x0 && create && (x0 = xfrm_state_alloc()) != NULL) {
x0->sel.daddr.a4 = daddr->a4;
x0->sel.saddr.a4 = saddr->a4;
x0->sel.prefixlen_d = 32;
x0->sel.prefixlen_s = 32;
x0->props.saddr.a4 = saddr->a4;
x0->km.state = XFRM_STATE_ACQ;
x0->id.daddr.a4 = daddr->a4;
x0->id.proto = proto;
x0->props.family = AF_INET;
x0->props.mode = mode;
x0->props.reqid = reqid;
x0->props.family = AF_INET;
x0->lft.hard_add_expires_seconds = XFRM_ACQ_EXPIRES;
xfrm_state_hold(x0);
x0->timer.expires = jiffies + XFRM_ACQ_EXPIRES*HZ;
add_timer(&x0->timer);
xfrm_state_hold(x0);
list_add_tail(&x0->bydst, xfrm4_state_afinfo.state_bydst+h);
wake_up(&km_waitq);
}
if (x0)
xfrm_state_hold(x0);
return x0;
}
static struct xfrm_state_afinfo xfrm4_state_afinfo = {
.family = AF_INET,
.init_flags = xfrm4_init_flags,
.init_tempsel = __xfrm4_init_tempsel,
.state_lookup = __xfrm4_state_lookup,
.find_acq = __xfrm4_find_acq,
};
void __init xfrm4_state_init(void)
{
xfrm_state_register_afinfo(&xfrm4_state_afinfo);
}
#if 0
void __exit xfrm4_state_fini(void)
{
xfrm_state_unregister_afinfo(&xfrm4_state_afinfo);
}
#endif /* 0 */