WSL2-Linux-Kernel/net/xfrm/xfrm_user.c

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33 KiB
C
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/* xfrm_user.c: User interface to configure xfrm engine.
*
* Copyright (C) 2002 David S. Miller (davem@redhat.com)
*
* Changes:
* Mitsuru KANDA @USAGI
* Kazunori MIYAZAWA @USAGI
* Kunihiro Ishiguro <kunihiro@ipinfusion.com>
* IPv6 support
*
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/socket.h>
#include <linux/string.h>
#include <linux/net.h>
#include <linux/skbuff.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <linux/pfkeyv2.h>
#include <linux/ipsec.h>
#include <linux/init.h>
#include <linux/security.h>
#include <net/sock.h>
#include <net/xfrm.h>
#include <asm/uaccess.h>
static struct sock *xfrm_nl;
static int verify_one_alg(struct rtattr **xfrma, enum xfrm_attr_type_t type)
{
struct rtattr *rt = xfrma[type - 1];
struct xfrm_algo *algp;
int len;
if (!rt)
return 0;
len = (rt->rta_len - sizeof(*rt)) - sizeof(*algp);
if (len < 0)
return -EINVAL;
algp = RTA_DATA(rt);
len -= (algp->alg_key_len + 7U) / 8;
if (len < 0)
return -EINVAL;
switch (type) {
case XFRMA_ALG_AUTH:
if (!algp->alg_key_len &&
strcmp(algp->alg_name, "digest_null") != 0)
return -EINVAL;
break;
case XFRMA_ALG_CRYPT:
if (!algp->alg_key_len &&
strcmp(algp->alg_name, "cipher_null") != 0)
return -EINVAL;
break;
case XFRMA_ALG_COMP:
/* Zero length keys are legal. */
break;
default:
return -EINVAL;
};
algp->alg_name[CRYPTO_MAX_ALG_NAME - 1] = '\0';
return 0;
}
static int verify_encap_tmpl(struct rtattr **xfrma)
{
struct rtattr *rt = xfrma[XFRMA_ENCAP - 1];
struct xfrm_encap_tmpl *encap;
if (!rt)
return 0;
if ((rt->rta_len - sizeof(*rt)) < sizeof(*encap))
return -EINVAL;
return 0;
}
static int verify_newsa_info(struct xfrm_usersa_info *p,
struct rtattr **xfrma)
{
int err;
err = -EINVAL;
switch (p->family) {
case AF_INET:
break;
case AF_INET6:
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
break;
#else
err = -EAFNOSUPPORT;
goto out;
#endif
default:
goto out;
};
err = -EINVAL;
switch (p->id.proto) {
case IPPROTO_AH:
if (!xfrma[XFRMA_ALG_AUTH-1] ||
xfrma[XFRMA_ALG_CRYPT-1] ||
xfrma[XFRMA_ALG_COMP-1])
goto out;
break;
case IPPROTO_ESP:
if ((!xfrma[XFRMA_ALG_AUTH-1] &&
!xfrma[XFRMA_ALG_CRYPT-1]) ||
xfrma[XFRMA_ALG_COMP-1])
goto out;
break;
case IPPROTO_COMP:
if (!xfrma[XFRMA_ALG_COMP-1] ||
xfrma[XFRMA_ALG_AUTH-1] ||
xfrma[XFRMA_ALG_CRYPT-1])
goto out;
break;
default:
goto out;
};
if ((err = verify_one_alg(xfrma, XFRMA_ALG_AUTH)))
goto out;
if ((err = verify_one_alg(xfrma, XFRMA_ALG_CRYPT)))
goto out;
if ((err = verify_one_alg(xfrma, XFRMA_ALG_COMP)))
goto out;
if ((err = verify_encap_tmpl(xfrma)))
goto out;
err = -EINVAL;
switch (p->mode) {
case 0:
case 1:
break;
default:
goto out;
};
err = 0;
out:
return err;
}
static int attach_one_algo(struct xfrm_algo **algpp, u8 *props,
struct xfrm_algo_desc *(*get_byname)(char *, int),
struct rtattr *u_arg)
{
struct rtattr *rta = u_arg;
struct xfrm_algo *p, *ualg;
struct xfrm_algo_desc *algo;
int len;
if (!rta)
return 0;
ualg = RTA_DATA(rta);
algo = get_byname(ualg->alg_name, 1);
if (!algo)
return -ENOSYS;
*props = algo->desc.sadb_alg_id;
len = sizeof(*ualg) + (ualg->alg_key_len + 7U) / 8;
p = kmalloc(len, GFP_KERNEL);
if (!p)
return -ENOMEM;
memcpy(p, ualg, len);
*algpp = p;
return 0;
}
static int attach_encap_tmpl(struct xfrm_encap_tmpl **encapp, struct rtattr *u_arg)
{
struct rtattr *rta = u_arg;
struct xfrm_encap_tmpl *p, *uencap;
if (!rta)
return 0;
uencap = RTA_DATA(rta);
p = kmalloc(sizeof(*p), GFP_KERNEL);
if (!p)
return -ENOMEM;
memcpy(p, uencap, sizeof(*p));
*encapp = p;
return 0;
}
static void copy_from_user_state(struct xfrm_state *x, struct xfrm_usersa_info *p)
{
memcpy(&x->id, &p->id, sizeof(x->id));
memcpy(&x->sel, &p->sel, sizeof(x->sel));
memcpy(&x->lft, &p->lft, sizeof(x->lft));
x->props.mode = p->mode;
x->props.replay_window = p->replay_window;
x->props.reqid = p->reqid;
x->props.family = p->family;
x->props.saddr = p->saddr;
x->props.flags = p->flags;
}
static struct xfrm_state *xfrm_state_construct(struct xfrm_usersa_info *p,
struct rtattr **xfrma,
int *errp)
{
struct xfrm_state *x = xfrm_state_alloc();
int err = -ENOMEM;
if (!x)
goto error_no_put;
copy_from_user_state(x, p);
if ((err = attach_one_algo(&x->aalg, &x->props.aalgo,
xfrm_aalg_get_byname,
xfrma[XFRMA_ALG_AUTH-1])))
goto error;
if ((err = attach_one_algo(&x->ealg, &x->props.ealgo,
xfrm_ealg_get_byname,
xfrma[XFRMA_ALG_CRYPT-1])))
goto error;
if ((err = attach_one_algo(&x->calg, &x->props.calgo,
xfrm_calg_get_byname,
xfrma[XFRMA_ALG_COMP-1])))
goto error;
if ((err = attach_encap_tmpl(&x->encap, xfrma[XFRMA_ENCAP-1])))
goto error;
err = xfrm_init_state(x);
if (err)
goto error;
x->km.seq = p->seq;
return x;
error:
x->km.state = XFRM_STATE_DEAD;
xfrm_state_put(x);
error_no_put:
*errp = err;
return NULL;
}
static int xfrm_add_sa(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
{
struct xfrm_usersa_info *p = NLMSG_DATA(nlh);
struct xfrm_state *x;
int err;
struct km_event c;
err = verify_newsa_info(p, (struct rtattr **) xfrma);
if (err)
return err;
x = xfrm_state_construct(p, (struct rtattr **) xfrma, &err);
if (!x)
return err;
xfrm_state_hold(x);
if (nlh->nlmsg_type == XFRM_MSG_NEWSA)
err = xfrm_state_add(x);
else
err = xfrm_state_update(x);
if (err < 0) {
x->km.state = XFRM_STATE_DEAD;
xfrm_state_put(x);
goto out;
}
c.seq = nlh->nlmsg_seq;
c.pid = nlh->nlmsg_pid;
c.event = nlh->nlmsg_type;
km_state_notify(x, &c);
out:
xfrm_state_put(x);
return err;
}
static int xfrm_del_sa(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
{
struct xfrm_state *x;
int err;
struct km_event c;
struct xfrm_usersa_id *p = NLMSG_DATA(nlh);
x = xfrm_state_lookup(&p->daddr, p->spi, p->proto, p->family);
if (x == NULL)
return -ESRCH;
if (xfrm_state_kern(x)) {
xfrm_state_put(x);
return -EPERM;
}
err = xfrm_state_delete(x);
if (err < 0) {
xfrm_state_put(x);
return err;
}
c.seq = nlh->nlmsg_seq;
c.pid = nlh->nlmsg_pid;
c.event = nlh->nlmsg_type;
km_state_notify(x, &c);
xfrm_state_put(x);
return err;
}
static void copy_to_user_state(struct xfrm_state *x, struct xfrm_usersa_info *p)
{
memcpy(&p->id, &x->id, sizeof(p->id));
memcpy(&p->sel, &x->sel, sizeof(p->sel));
memcpy(&p->lft, &x->lft, sizeof(p->lft));
memcpy(&p->curlft, &x->curlft, sizeof(p->curlft));
memcpy(&p->stats, &x->stats, sizeof(p->stats));
p->saddr = x->props.saddr;
p->mode = x->props.mode;
p->replay_window = x->props.replay_window;
p->reqid = x->props.reqid;
p->family = x->props.family;
p->flags = x->props.flags;
p->seq = x->km.seq;
}
struct xfrm_dump_info {
struct sk_buff *in_skb;
struct sk_buff *out_skb;
u32 nlmsg_seq;
u16 nlmsg_flags;
int start_idx;
int this_idx;
};
static int dump_one_state(struct xfrm_state *x, int count, void *ptr)
{
struct xfrm_dump_info *sp = ptr;
struct sk_buff *in_skb = sp->in_skb;
struct sk_buff *skb = sp->out_skb;
struct xfrm_usersa_info *p;
struct nlmsghdr *nlh;
unsigned char *b = skb->tail;
if (sp->this_idx < sp->start_idx)
goto out;
nlh = NLMSG_PUT(skb, NETLINK_CB(in_skb).pid,
sp->nlmsg_seq,
XFRM_MSG_NEWSA, sizeof(*p));
nlh->nlmsg_flags = sp->nlmsg_flags;
p = NLMSG_DATA(nlh);
copy_to_user_state(x, p);
if (x->aalg)
RTA_PUT(skb, XFRMA_ALG_AUTH,
sizeof(*(x->aalg))+(x->aalg->alg_key_len+7)/8, x->aalg);
if (x->ealg)
RTA_PUT(skb, XFRMA_ALG_CRYPT,
sizeof(*(x->ealg))+(x->ealg->alg_key_len+7)/8, x->ealg);
if (x->calg)
RTA_PUT(skb, XFRMA_ALG_COMP, sizeof(*(x->calg)), x->calg);
if (x->encap)
RTA_PUT(skb, XFRMA_ENCAP, sizeof(*x->encap), x->encap);
nlh->nlmsg_len = skb->tail - b;
out:
sp->this_idx++;
return 0;
nlmsg_failure:
rtattr_failure:
skb_trim(skb, b - skb->data);
return -1;
}
static int xfrm_dump_sa(struct sk_buff *skb, struct netlink_callback *cb)
{
struct xfrm_dump_info info;
info.in_skb = cb->skb;
info.out_skb = skb;
info.nlmsg_seq = cb->nlh->nlmsg_seq;
info.nlmsg_flags = NLM_F_MULTI;
info.this_idx = 0;
info.start_idx = cb->args[0];
(void) xfrm_state_walk(IPSEC_PROTO_ANY, dump_one_state, &info);
cb->args[0] = info.this_idx;
return skb->len;
}
static struct sk_buff *xfrm_state_netlink(struct sk_buff *in_skb,
struct xfrm_state *x, u32 seq)
{
struct xfrm_dump_info info;
struct sk_buff *skb;
skb = alloc_skb(NLMSG_GOODSIZE, GFP_ATOMIC);
if (!skb)
return ERR_PTR(-ENOMEM);
NETLINK_CB(skb).dst_pid = NETLINK_CB(in_skb).pid;
info.in_skb = in_skb;
info.out_skb = skb;
info.nlmsg_seq = seq;
info.nlmsg_flags = 0;
info.this_idx = info.start_idx = 0;
if (dump_one_state(x, 0, &info)) {
kfree_skb(skb);
return NULL;
}
return skb;
}
static int xfrm_get_sa(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
{
struct xfrm_usersa_id *p = NLMSG_DATA(nlh);
struct xfrm_state *x;
struct sk_buff *resp_skb;
int err;
x = xfrm_state_lookup(&p->daddr, p->spi, p->proto, p->family);
err = -ESRCH;
if (x == NULL)
goto out_noput;
resp_skb = xfrm_state_netlink(skb, x, nlh->nlmsg_seq);
if (IS_ERR(resp_skb)) {
err = PTR_ERR(resp_skb);
} else {
err = netlink_unicast(xfrm_nl, resp_skb,
NETLINK_CB(skb).pid, MSG_DONTWAIT);
}
xfrm_state_put(x);
out_noput:
return err;
}
static int verify_userspi_info(struct xfrm_userspi_info *p)
{
switch (p->info.id.proto) {
case IPPROTO_AH:
case IPPROTO_ESP:
break;
case IPPROTO_COMP:
/* IPCOMP spi is 16-bits. */
if (p->max >= 0x10000)
return -EINVAL;
break;
default:
return -EINVAL;
};
if (p->min > p->max)
return -EINVAL;
return 0;
}
static int xfrm_alloc_userspi(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
{
struct xfrm_state *x;
struct xfrm_userspi_info *p;
struct sk_buff *resp_skb;
xfrm_address_t *daddr;
int family;
int err;
p = NLMSG_DATA(nlh);
err = verify_userspi_info(p);
if (err)
goto out_noput;
family = p->info.family;
daddr = &p->info.id.daddr;
x = NULL;
if (p->info.seq) {
x = xfrm_find_acq_byseq(p->info.seq);
if (x && xfrm_addr_cmp(&x->id.daddr, daddr, family)) {
xfrm_state_put(x);
x = NULL;
}
}
if (!x)
x = xfrm_find_acq(p->info.mode, p->info.reqid,
p->info.id.proto, daddr,
&p->info.saddr, 1,
family);
err = -ENOENT;
if (x == NULL)
goto out_noput;
resp_skb = ERR_PTR(-ENOENT);
spin_lock_bh(&x->lock);
if (x->km.state != XFRM_STATE_DEAD) {
xfrm_alloc_spi(x, htonl(p->min), htonl(p->max));
if (x->id.spi)
resp_skb = xfrm_state_netlink(skb, x, nlh->nlmsg_seq);
}
spin_unlock_bh(&x->lock);
if (IS_ERR(resp_skb)) {
err = PTR_ERR(resp_skb);
goto out;
}
err = netlink_unicast(xfrm_nl, resp_skb,
NETLINK_CB(skb).pid, MSG_DONTWAIT);
out:
xfrm_state_put(x);
out_noput:
return err;
}
static int verify_policy_dir(__u8 dir)
{
switch (dir) {
case XFRM_POLICY_IN:
case XFRM_POLICY_OUT:
case XFRM_POLICY_FWD:
break;
default:
return -EINVAL;
};
return 0;
}
static int verify_newpolicy_info(struct xfrm_userpolicy_info *p)
{
switch (p->share) {
case XFRM_SHARE_ANY:
case XFRM_SHARE_SESSION:
case XFRM_SHARE_USER:
case XFRM_SHARE_UNIQUE:
break;
default:
return -EINVAL;
};
switch (p->action) {
case XFRM_POLICY_ALLOW:
case XFRM_POLICY_BLOCK:
break;
default:
return -EINVAL;
};
switch (p->sel.family) {
case AF_INET:
break;
case AF_INET6:
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
break;
#else
return -EAFNOSUPPORT;
#endif
default:
return -EINVAL;
};
return verify_policy_dir(p->dir);
}
static void copy_templates(struct xfrm_policy *xp, struct xfrm_user_tmpl *ut,
int nr)
{
int i;
xp->xfrm_nr = nr;
for (i = 0; i < nr; i++, ut++) {
struct xfrm_tmpl *t = &xp->xfrm_vec[i];
memcpy(&t->id, &ut->id, sizeof(struct xfrm_id));
memcpy(&t->saddr, &ut->saddr,
sizeof(xfrm_address_t));
t->reqid = ut->reqid;
t->mode = ut->mode;
t->share = ut->share;
t->optional = ut->optional;
t->aalgos = ut->aalgos;
t->ealgos = ut->ealgos;
t->calgos = ut->calgos;
}
}
static int copy_from_user_tmpl(struct xfrm_policy *pol, struct rtattr **xfrma)
{
struct rtattr *rt = xfrma[XFRMA_TMPL-1];
struct xfrm_user_tmpl *utmpl;
int nr;
if (!rt) {
pol->xfrm_nr = 0;
} else {
nr = (rt->rta_len - sizeof(*rt)) / sizeof(*utmpl);
if (nr > XFRM_MAX_DEPTH)
return -EINVAL;
copy_templates(pol, RTA_DATA(rt), nr);
}
return 0;
}
static void copy_from_user_policy(struct xfrm_policy *xp, struct xfrm_userpolicy_info *p)
{
xp->priority = p->priority;
xp->index = p->index;
memcpy(&xp->selector, &p->sel, sizeof(xp->selector));
memcpy(&xp->lft, &p->lft, sizeof(xp->lft));
xp->action = p->action;
xp->flags = p->flags;
xp->family = p->sel.family;
/* XXX xp->share = p->share; */
}
static void copy_to_user_policy(struct xfrm_policy *xp, struct xfrm_userpolicy_info *p, int dir)
{
memcpy(&p->sel, &xp->selector, sizeof(p->sel));
memcpy(&p->lft, &xp->lft, sizeof(p->lft));
memcpy(&p->curlft, &xp->curlft, sizeof(p->curlft));
p->priority = xp->priority;
p->index = xp->index;
p->sel.family = xp->family;
p->dir = dir;
p->action = xp->action;
p->flags = xp->flags;
p->share = XFRM_SHARE_ANY; /* XXX xp->share */
}
static struct xfrm_policy *xfrm_policy_construct(struct xfrm_userpolicy_info *p, struct rtattr **xfrma, int *errp)
{
struct xfrm_policy *xp = xfrm_policy_alloc(GFP_KERNEL);
int err;
if (!xp) {
*errp = -ENOMEM;
return NULL;
}
copy_from_user_policy(xp, p);
err = copy_from_user_tmpl(xp, xfrma);
if (err) {
*errp = err;
kfree(xp);
xp = NULL;
}
return xp;
}
static int xfrm_add_policy(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
{
struct xfrm_userpolicy_info *p = NLMSG_DATA(nlh);
struct xfrm_policy *xp;
struct km_event c;
int err;
int excl;
err = verify_newpolicy_info(p);
if (err)
return err;
xp = xfrm_policy_construct(p, (struct rtattr **) xfrma, &err);
if (!xp)
return err;
/* shouldnt excl be based on nlh flags??
* Aha! this is anti-netlink really i.e more pfkey derived
* in netlink excl is a flag and you wouldnt need
* a type XFRM_MSG_UPDPOLICY - JHS */
excl = nlh->nlmsg_type == XFRM_MSG_NEWPOLICY;
err = xfrm_policy_insert(p->dir, xp, excl);
if (err) {
kfree(xp);
return err;
}
c.event = nlh->nlmsg_type;
c.seq = nlh->nlmsg_seq;
c.pid = nlh->nlmsg_pid;
km_policy_notify(xp, p->dir, &c);
xfrm_pol_put(xp);
return 0;
}
static int copy_to_user_tmpl(struct xfrm_policy *xp, struct sk_buff *skb)
{
struct xfrm_user_tmpl vec[XFRM_MAX_DEPTH];
int i;
if (xp->xfrm_nr == 0)
return 0;
for (i = 0; i < xp->xfrm_nr; i++) {
struct xfrm_user_tmpl *up = &vec[i];
struct xfrm_tmpl *kp = &xp->xfrm_vec[i];
memcpy(&up->id, &kp->id, sizeof(up->id));
up->family = xp->family;
memcpy(&up->saddr, &kp->saddr, sizeof(up->saddr));
up->reqid = kp->reqid;
up->mode = kp->mode;
up->share = kp->share;
up->optional = kp->optional;
up->aalgos = kp->aalgos;
up->ealgos = kp->ealgos;
up->calgos = kp->calgos;
}
RTA_PUT(skb, XFRMA_TMPL,
(sizeof(struct xfrm_user_tmpl) * xp->xfrm_nr),
vec);
return 0;
rtattr_failure:
return -1;
}
static int dump_one_policy(struct xfrm_policy *xp, int dir, int count, void *ptr)
{
struct xfrm_dump_info *sp = ptr;
struct xfrm_userpolicy_info *p;
struct sk_buff *in_skb = sp->in_skb;
struct sk_buff *skb = sp->out_skb;
struct nlmsghdr *nlh;
unsigned char *b = skb->tail;
if (sp->this_idx < sp->start_idx)
goto out;
nlh = NLMSG_PUT(skb, NETLINK_CB(in_skb).pid,
sp->nlmsg_seq,
XFRM_MSG_NEWPOLICY, sizeof(*p));
p = NLMSG_DATA(nlh);
nlh->nlmsg_flags = sp->nlmsg_flags;
copy_to_user_policy(xp, p, dir);
if (copy_to_user_tmpl(xp, skb) < 0)
goto nlmsg_failure;
nlh->nlmsg_len = skb->tail - b;
out:
sp->this_idx++;
return 0;
nlmsg_failure:
skb_trim(skb, b - skb->data);
return -1;
}
static int xfrm_dump_policy(struct sk_buff *skb, struct netlink_callback *cb)
{
struct xfrm_dump_info info;
info.in_skb = cb->skb;
info.out_skb = skb;
info.nlmsg_seq = cb->nlh->nlmsg_seq;
info.nlmsg_flags = NLM_F_MULTI;
info.this_idx = 0;
info.start_idx = cb->args[0];
(void) xfrm_policy_walk(dump_one_policy, &info);
cb->args[0] = info.this_idx;
return skb->len;
}
static struct sk_buff *xfrm_policy_netlink(struct sk_buff *in_skb,
struct xfrm_policy *xp,
int dir, u32 seq)
{
struct xfrm_dump_info info;
struct sk_buff *skb;
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb)
return ERR_PTR(-ENOMEM);
NETLINK_CB(skb).dst_pid = NETLINK_CB(in_skb).pid;
info.in_skb = in_skb;
info.out_skb = skb;
info.nlmsg_seq = seq;
info.nlmsg_flags = 0;
info.this_idx = info.start_idx = 0;
if (dump_one_policy(xp, dir, 0, &info) < 0) {
kfree_skb(skb);
return NULL;
}
return skb;
}
static int xfrm_get_policy(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
{
struct xfrm_policy *xp;
struct xfrm_userpolicy_id *p;
int err;
struct km_event c;
int delete;
p = NLMSG_DATA(nlh);
delete = nlh->nlmsg_type == XFRM_MSG_DELPOLICY;
err = verify_policy_dir(p->dir);
if (err)
return err;
if (p->index)
xp = xfrm_policy_byid(p->dir, p->index, delete);
else
xp = xfrm_policy_bysel(p->dir, &p->sel, delete);
if (xp == NULL)
return -ENOENT;
if (!delete) {
struct sk_buff *resp_skb;
resp_skb = xfrm_policy_netlink(skb, xp, p->dir, nlh->nlmsg_seq);
if (IS_ERR(resp_skb)) {
err = PTR_ERR(resp_skb);
} else {
err = netlink_unicast(xfrm_nl, resp_skb,
NETLINK_CB(skb).pid,
MSG_DONTWAIT);
}
} else {
c.data.byid = p->index;
c.event = nlh->nlmsg_type;
c.seq = nlh->nlmsg_seq;
c.pid = nlh->nlmsg_pid;
km_policy_notify(xp, p->dir, &c);
}
xfrm_pol_put(xp);
return err;
}
static int xfrm_flush_sa(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
{
struct km_event c;
struct xfrm_usersa_flush *p = NLMSG_DATA(nlh);
xfrm_state_flush(p->proto);
c.data.proto = p->proto;
c.event = nlh->nlmsg_type;
c.seq = nlh->nlmsg_seq;
c.pid = nlh->nlmsg_pid;
km_state_notify(NULL, &c);
return 0;
}
static int xfrm_flush_policy(struct sk_buff *skb, struct nlmsghdr *nlh, void **xfrma)
{
struct km_event c;
xfrm_policy_flush();
c.event = nlh->nlmsg_type;
c.seq = nlh->nlmsg_seq;
c.pid = nlh->nlmsg_pid;
km_policy_notify(NULL, 0, &c);
return 0;
}
#define XMSGSIZE(type) NLMSG_LENGTH(sizeof(struct type))
static const int xfrm_msg_min[XFRM_NR_MSGTYPES] = {
[XFRM_MSG_NEWSA - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_info),
[XFRM_MSG_DELSA - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_id),
[XFRM_MSG_GETSA - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_id),
[XFRM_MSG_NEWPOLICY - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userpolicy_info),
[XFRM_MSG_DELPOLICY - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userpolicy_id),
[XFRM_MSG_GETPOLICY - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userpolicy_id),
[XFRM_MSG_ALLOCSPI - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userspi_info),
[XFRM_MSG_ACQUIRE - XFRM_MSG_BASE] = XMSGSIZE(xfrm_user_acquire),
[XFRM_MSG_EXPIRE - XFRM_MSG_BASE] = XMSGSIZE(xfrm_user_expire),
[XFRM_MSG_UPDPOLICY - XFRM_MSG_BASE] = XMSGSIZE(xfrm_userpolicy_info),
[XFRM_MSG_UPDSA - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_info),
[XFRM_MSG_POLEXPIRE - XFRM_MSG_BASE] = XMSGSIZE(xfrm_user_polexpire),
[XFRM_MSG_FLUSHSA - XFRM_MSG_BASE] = XMSGSIZE(xfrm_usersa_flush),
[XFRM_MSG_FLUSHPOLICY - XFRM_MSG_BASE] = NLMSG_LENGTH(0),
};
#undef XMSGSIZE
static struct xfrm_link {
int (*doit)(struct sk_buff *, struct nlmsghdr *, void **);
int (*dump)(struct sk_buff *, struct netlink_callback *);
} xfrm_dispatch[XFRM_NR_MSGTYPES] = {
[XFRM_MSG_NEWSA - XFRM_MSG_BASE] = { .doit = xfrm_add_sa },
[XFRM_MSG_DELSA - XFRM_MSG_BASE] = { .doit = xfrm_del_sa },
[XFRM_MSG_GETSA - XFRM_MSG_BASE] = { .doit = xfrm_get_sa,
.dump = xfrm_dump_sa },
[XFRM_MSG_NEWPOLICY - XFRM_MSG_BASE] = { .doit = xfrm_add_policy },
[XFRM_MSG_DELPOLICY - XFRM_MSG_BASE] = { .doit = xfrm_get_policy },
[XFRM_MSG_GETPOLICY - XFRM_MSG_BASE] = { .doit = xfrm_get_policy,
.dump = xfrm_dump_policy },
[XFRM_MSG_ALLOCSPI - XFRM_MSG_BASE] = { .doit = xfrm_alloc_userspi },
[XFRM_MSG_UPDPOLICY - XFRM_MSG_BASE] = { .doit = xfrm_add_policy },
[XFRM_MSG_UPDSA - XFRM_MSG_BASE] = { .doit = xfrm_add_sa },
[XFRM_MSG_FLUSHSA - XFRM_MSG_BASE] = { .doit = xfrm_flush_sa },
[XFRM_MSG_FLUSHPOLICY - XFRM_MSG_BASE] = { .doit = xfrm_flush_policy },
};
static int xfrm_done(struct netlink_callback *cb)
{
return 0;
}
static int xfrm_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, int *errp)
{
struct rtattr *xfrma[XFRMA_MAX];
struct xfrm_link *link;
int type, min_len;
if (!(nlh->nlmsg_flags & NLM_F_REQUEST))
return 0;
type = nlh->nlmsg_type;
/* A control message: ignore them */
if (type < XFRM_MSG_BASE)
return 0;
/* Unknown message: reply with EINVAL */
if (type > XFRM_MSG_MAX)
goto err_einval;
type -= XFRM_MSG_BASE;
link = &xfrm_dispatch[type];
/* All operations require privileges, even GET */
if (security_netlink_recv(skb)) {
*errp = -EPERM;
return -1;
}
if ((type == (XFRM_MSG_GETSA - XFRM_MSG_BASE) ||
type == (XFRM_MSG_GETPOLICY - XFRM_MSG_BASE)) &&
(nlh->nlmsg_flags & NLM_F_DUMP)) {
u32 rlen;
if (link->dump == NULL)
goto err_einval;
if ((*errp = netlink_dump_start(xfrm_nl, skb, nlh,
link->dump,
xfrm_done)) != 0) {
return -1;
}
rlen = NLMSG_ALIGN(nlh->nlmsg_len);
if (rlen > skb->len)
rlen = skb->len;
skb_pull(skb, rlen);
return -1;
}
memset(xfrma, 0, sizeof(xfrma));
if (nlh->nlmsg_len < (min_len = xfrm_msg_min[type]))
goto err_einval;
if (nlh->nlmsg_len > min_len) {
int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len);
struct rtattr *attr = (void *) nlh + NLMSG_ALIGN(min_len);
while (RTA_OK(attr, attrlen)) {
unsigned short flavor = attr->rta_type;
if (flavor) {
if (flavor > XFRMA_MAX)
goto err_einval;
xfrma[flavor - 1] = attr;
}
attr = RTA_NEXT(attr, attrlen);
}
}
if (link->doit == NULL)
goto err_einval;
*errp = link->doit(skb, nlh, (void **) &xfrma);
return *errp;
err_einval:
*errp = -EINVAL;
return -1;
}
static int xfrm_user_rcv_skb(struct sk_buff *skb)
{
int err;
struct nlmsghdr *nlh;
while (skb->len >= NLMSG_SPACE(0)) {
u32 rlen;
nlh = (struct nlmsghdr *) skb->data;
if (nlh->nlmsg_len < sizeof(*nlh) ||
skb->len < nlh->nlmsg_len)
return 0;
rlen = NLMSG_ALIGN(nlh->nlmsg_len);
if (rlen > skb->len)
rlen = skb->len;
if (xfrm_user_rcv_msg(skb, nlh, &err) < 0) {
if (err == 0)
return -1;
netlink_ack(skb, nlh, err);
} else if (nlh->nlmsg_flags & NLM_F_ACK)
netlink_ack(skb, nlh, 0);
skb_pull(skb, rlen);
}
return 0;
}
static void xfrm_netlink_rcv(struct sock *sk, int len)
{
[NETLINK]: Synchronous message processing. Let's recap the problem. The current asynchronous netlink kernel message processing is vulnerable to these attacks: 1) Hit and run: Attacker sends one or more messages and then exits before they're processed. This may confuse/disable the next netlink user that gets the netlink address of the attacker since it may receive the responses to the attacker's messages. Proposed solutions: a) Synchronous processing. b) Stream mode socket. c) Restrict/prohibit binding. 2) Starvation: Because various netlink rcv functions were written to not return until all messages have been processed on a socket, it is possible for these functions to execute for an arbitrarily long period of time. If this is successfully exploited it could also be used to hold rtnl forever. Proposed solutions: a) Synchronous processing. b) Stream mode socket. Firstly let's cross off solution c). It only solves the first problem and it has user-visible impacts. In particular, it'll break user space applications that expect to bind or communicate with specific netlink addresses (pid's). So we're left with a choice of synchronous processing versus SOCK_STREAM for netlink. For the moment I'm sticking with the synchronous approach as suggested by Alexey since it's simpler and I'd rather spend my time working on other things. However, it does have a number of deficiencies compared to the stream mode solution: 1) User-space to user-space netlink communication is still vulnerable. 2) Inefficient use of resources. This is especially true for rtnetlink since the lock is shared with other users such as networking drivers. The latter could hold the rtnl while communicating with hardware which causes the rtnetlink user to wait when it could be doing other things. 3) It is still possible to DoS all netlink users by flooding the kernel netlink receive queue. The attacker simply fills the receive socket with a single netlink message that fills up the entire queue. The attacker then continues to call sendmsg with the same message in a loop. Point 3) can be countered by retransmissions in user-space code, however it is pretty messy. In light of these problems (in particular, point 3), we should implement stream mode netlink at some point. In the mean time, here is a patch that implements synchronous processing. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-05-04 01:55:09 +04:00
unsigned int qlen = skb_queue_len(&sk->sk_receive_queue);
do {
struct sk_buff *skb;
down(&xfrm_cfg_sem);
[NETLINK]: Synchronous message processing. Let's recap the problem. The current asynchronous netlink kernel message processing is vulnerable to these attacks: 1) Hit and run: Attacker sends one or more messages and then exits before they're processed. This may confuse/disable the next netlink user that gets the netlink address of the attacker since it may receive the responses to the attacker's messages. Proposed solutions: a) Synchronous processing. b) Stream mode socket. c) Restrict/prohibit binding. 2) Starvation: Because various netlink rcv functions were written to not return until all messages have been processed on a socket, it is possible for these functions to execute for an arbitrarily long period of time. If this is successfully exploited it could also be used to hold rtnl forever. Proposed solutions: a) Synchronous processing. b) Stream mode socket. Firstly let's cross off solution c). It only solves the first problem and it has user-visible impacts. In particular, it'll break user space applications that expect to bind or communicate with specific netlink addresses (pid's). So we're left with a choice of synchronous processing versus SOCK_STREAM for netlink. For the moment I'm sticking with the synchronous approach as suggested by Alexey since it's simpler and I'd rather spend my time working on other things. However, it does have a number of deficiencies compared to the stream mode solution: 1) User-space to user-space netlink communication is still vulnerable. 2) Inefficient use of resources. This is especially true for rtnetlink since the lock is shared with other users such as networking drivers. The latter could hold the rtnl while communicating with hardware which causes the rtnetlink user to wait when it could be doing other things. 3) It is still possible to DoS all netlink users by flooding the kernel netlink receive queue. The attacker simply fills the receive socket with a single netlink message that fills up the entire queue. The attacker then continues to call sendmsg with the same message in a loop. Point 3) can be countered by retransmissions in user-space code, however it is pretty messy. In light of these problems (in particular, point 3), we should implement stream mode netlink at some point. In the mean time, here is a patch that implements synchronous processing. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-05-04 01:55:09 +04:00
if (qlen > skb_queue_len(&sk->sk_receive_queue))
qlen = skb_queue_len(&sk->sk_receive_queue);
for (; qlen; qlen--) {
[NETLINK]: Synchronous message processing. Let's recap the problem. The current asynchronous netlink kernel message processing is vulnerable to these attacks: 1) Hit and run: Attacker sends one or more messages and then exits before they're processed. This may confuse/disable the next netlink user that gets the netlink address of the attacker since it may receive the responses to the attacker's messages. Proposed solutions: a) Synchronous processing. b) Stream mode socket. c) Restrict/prohibit binding. 2) Starvation: Because various netlink rcv functions were written to not return until all messages have been processed on a socket, it is possible for these functions to execute for an arbitrarily long period of time. If this is successfully exploited it could also be used to hold rtnl forever. Proposed solutions: a) Synchronous processing. b) Stream mode socket. Firstly let's cross off solution c). It only solves the first problem and it has user-visible impacts. In particular, it'll break user space applications that expect to bind or communicate with specific netlink addresses (pid's). So we're left with a choice of synchronous processing versus SOCK_STREAM for netlink. For the moment I'm sticking with the synchronous approach as suggested by Alexey since it's simpler and I'd rather spend my time working on other things. However, it does have a number of deficiencies compared to the stream mode solution: 1) User-space to user-space netlink communication is still vulnerable. 2) Inefficient use of resources. This is especially true for rtnetlink since the lock is shared with other users such as networking drivers. The latter could hold the rtnl while communicating with hardware which causes the rtnetlink user to wait when it could be doing other things. 3) It is still possible to DoS all netlink users by flooding the kernel netlink receive queue. The attacker simply fills the receive socket with a single netlink message that fills up the entire queue. The attacker then continues to call sendmsg with the same message in a loop. Point 3) can be countered by retransmissions in user-space code, however it is pretty messy. In light of these problems (in particular, point 3), we should implement stream mode netlink at some point. In the mean time, here is a patch that implements synchronous processing. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-05-04 01:55:09 +04:00
skb = skb_dequeue(&sk->sk_receive_queue);
if (xfrm_user_rcv_skb(skb)) {
if (skb->len)
skb_queue_head(&sk->sk_receive_queue,
skb);
else {
kfree_skb(skb);
qlen--;
}
break;
}
kfree_skb(skb);
}
up(&xfrm_cfg_sem);
[NETLINK]: Synchronous message processing. Let's recap the problem. The current asynchronous netlink kernel message processing is vulnerable to these attacks: 1) Hit and run: Attacker sends one or more messages and then exits before they're processed. This may confuse/disable the next netlink user that gets the netlink address of the attacker since it may receive the responses to the attacker's messages. Proposed solutions: a) Synchronous processing. b) Stream mode socket. c) Restrict/prohibit binding. 2) Starvation: Because various netlink rcv functions were written to not return until all messages have been processed on a socket, it is possible for these functions to execute for an arbitrarily long period of time. If this is successfully exploited it could also be used to hold rtnl forever. Proposed solutions: a) Synchronous processing. b) Stream mode socket. Firstly let's cross off solution c). It only solves the first problem and it has user-visible impacts. In particular, it'll break user space applications that expect to bind or communicate with specific netlink addresses (pid's). So we're left with a choice of synchronous processing versus SOCK_STREAM for netlink. For the moment I'm sticking with the synchronous approach as suggested by Alexey since it's simpler and I'd rather spend my time working on other things. However, it does have a number of deficiencies compared to the stream mode solution: 1) User-space to user-space netlink communication is still vulnerable. 2) Inefficient use of resources. This is especially true for rtnetlink since the lock is shared with other users such as networking drivers. The latter could hold the rtnl while communicating with hardware which causes the rtnetlink user to wait when it could be doing other things. 3) It is still possible to DoS all netlink users by flooding the kernel netlink receive queue. The attacker simply fills the receive socket with a single netlink message that fills up the entire queue. The attacker then continues to call sendmsg with the same message in a loop. Point 3) can be countered by retransmissions in user-space code, however it is pretty messy. In light of these problems (in particular, point 3), we should implement stream mode netlink at some point. In the mean time, here is a patch that implements synchronous processing. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-05-04 01:55:09 +04:00
} while (qlen);
}
static int build_expire(struct sk_buff *skb, struct xfrm_state *x, int hard)
{
struct xfrm_user_expire *ue;
struct nlmsghdr *nlh;
unsigned char *b = skb->tail;
nlh = NLMSG_PUT(skb, 0, 0, XFRM_MSG_EXPIRE,
sizeof(*ue));
ue = NLMSG_DATA(nlh);
nlh->nlmsg_flags = 0;
copy_to_user_state(x, &ue->state);
ue->hard = (hard != 0) ? 1 : 0;
nlh->nlmsg_len = skb->tail - b;
return skb->len;
nlmsg_failure:
skb_trim(skb, b - skb->data);
return -1;
}
static int xfrm_exp_state_notify(struct xfrm_state *x, struct km_event *c)
{
struct sk_buff *skb;
int len = NLMSG_LENGTH(sizeof(struct xfrm_user_expire));
skb = alloc_skb(len, GFP_ATOMIC);
if (skb == NULL)
return -ENOMEM;
if (build_expire(skb, x, c->data.hard) < 0)
BUG();
NETLINK_CB(skb).dst_group = XFRMNLGRP_EXPIRE;
return netlink_broadcast(xfrm_nl, skb, 0, XFRMNLGRP_EXPIRE, GFP_ATOMIC);
}
static int xfrm_notify_sa_flush(struct km_event *c)
{
struct xfrm_usersa_flush *p;
struct nlmsghdr *nlh;
struct sk_buff *skb;
unsigned char *b;
int len = NLMSG_LENGTH(sizeof(struct xfrm_usersa_flush));
skb = alloc_skb(len, GFP_ATOMIC);
if (skb == NULL)
return -ENOMEM;
b = skb->tail;
nlh = NLMSG_PUT(skb, c->pid, c->seq,
XFRM_MSG_FLUSHSA, sizeof(*p));
nlh->nlmsg_flags = 0;
p = NLMSG_DATA(nlh);
p->proto = c->data.proto;
nlh->nlmsg_len = skb->tail - b;
NETLINK_CB(skb).dst_group = XFRMNLGRP_SA;
return netlink_broadcast(xfrm_nl, skb, 0, XFRMNLGRP_SA, GFP_ATOMIC);
nlmsg_failure:
kfree_skb(skb);
return -1;
}
static int inline xfrm_sa_len(struct xfrm_state *x)
{
int l = 0;
if (x->aalg)
l += RTA_SPACE(sizeof(*x->aalg) + (x->aalg->alg_key_len+7)/8);
if (x->ealg)
l += RTA_SPACE(sizeof(*x->ealg) + (x->ealg->alg_key_len+7)/8);
if (x->calg)
l += RTA_SPACE(sizeof(*x->calg));
if (x->encap)
l += RTA_SPACE(sizeof(*x->encap));
return l;
}
static int xfrm_notify_sa(struct xfrm_state *x, struct km_event *c)
{
struct xfrm_usersa_info *p;
struct xfrm_usersa_id *id;
struct nlmsghdr *nlh;
struct sk_buff *skb;
unsigned char *b;
int len = xfrm_sa_len(x);
int headlen;
headlen = sizeof(*p);
if (c->event == XFRM_MSG_DELSA) {
len += RTA_SPACE(headlen);
headlen = sizeof(*id);
}
len += NLMSG_SPACE(headlen);
skb = alloc_skb(len, GFP_ATOMIC);
if (skb == NULL)
return -ENOMEM;
b = skb->tail;
nlh = NLMSG_PUT(skb, c->pid, c->seq, c->event, headlen);
nlh->nlmsg_flags = 0;
p = NLMSG_DATA(nlh);
if (c->event == XFRM_MSG_DELSA) {
id = NLMSG_DATA(nlh);
memcpy(&id->daddr, &x->id.daddr, sizeof(id->daddr));
id->spi = x->id.spi;
id->family = x->props.family;
id->proto = x->id.proto;
p = RTA_DATA(__RTA_PUT(skb, XFRMA_SA, sizeof(*p)));
}
copy_to_user_state(x, p);
if (x->aalg)
RTA_PUT(skb, XFRMA_ALG_AUTH,
sizeof(*(x->aalg))+(x->aalg->alg_key_len+7)/8, x->aalg);
if (x->ealg)
RTA_PUT(skb, XFRMA_ALG_CRYPT,
sizeof(*(x->ealg))+(x->ealg->alg_key_len+7)/8, x->ealg);
if (x->calg)
RTA_PUT(skb, XFRMA_ALG_COMP, sizeof(*(x->calg)), x->calg);
if (x->encap)
RTA_PUT(skb, XFRMA_ENCAP, sizeof(*x->encap), x->encap);
nlh->nlmsg_len = skb->tail - b;
NETLINK_CB(skb).dst_group = XFRMNLGRP_SA;
return netlink_broadcast(xfrm_nl, skb, 0, XFRMNLGRP_SA, GFP_ATOMIC);
nlmsg_failure:
rtattr_failure:
kfree_skb(skb);
return -1;
}
static int xfrm_send_state_notify(struct xfrm_state *x, struct km_event *c)
{
switch (c->event) {
case XFRM_MSG_EXPIRE:
return xfrm_exp_state_notify(x, c);
case XFRM_MSG_DELSA:
case XFRM_MSG_UPDSA:
case XFRM_MSG_NEWSA:
return xfrm_notify_sa(x, c);
case XFRM_MSG_FLUSHSA:
return xfrm_notify_sa_flush(c);
default:
printk("xfrm_user: Unknown SA event %d\n", c->event);
break;
}
return 0;
}
static int build_acquire(struct sk_buff *skb, struct xfrm_state *x,
struct xfrm_tmpl *xt, struct xfrm_policy *xp,
int dir)
{
struct xfrm_user_acquire *ua;
struct nlmsghdr *nlh;
unsigned char *b = skb->tail;
__u32 seq = xfrm_get_acqseq();
nlh = NLMSG_PUT(skb, 0, 0, XFRM_MSG_ACQUIRE,
sizeof(*ua));
ua = NLMSG_DATA(nlh);
nlh->nlmsg_flags = 0;
memcpy(&ua->id, &x->id, sizeof(ua->id));
memcpy(&ua->saddr, &x->props.saddr, sizeof(ua->saddr));
memcpy(&ua->sel, &x->sel, sizeof(ua->sel));
copy_to_user_policy(xp, &ua->policy, dir);
ua->aalgos = xt->aalgos;
ua->ealgos = xt->ealgos;
ua->calgos = xt->calgos;
ua->seq = x->km.seq = seq;
if (copy_to_user_tmpl(xp, skb) < 0)
goto nlmsg_failure;
nlh->nlmsg_len = skb->tail - b;
return skb->len;
nlmsg_failure:
skb_trim(skb, b - skb->data);
return -1;
}
static int xfrm_send_acquire(struct xfrm_state *x, struct xfrm_tmpl *xt,
struct xfrm_policy *xp, int dir)
{
struct sk_buff *skb;
size_t len;
len = RTA_SPACE(sizeof(struct xfrm_user_tmpl) * xp->xfrm_nr);
len += NLMSG_SPACE(sizeof(struct xfrm_user_acquire));
skb = alloc_skb(len, GFP_ATOMIC);
if (skb == NULL)
return -ENOMEM;
if (build_acquire(skb, x, xt, xp, dir) < 0)
BUG();
NETLINK_CB(skb).dst_group = XFRMNLGRP_ACQUIRE;
return netlink_broadcast(xfrm_nl, skb, 0, XFRMNLGRP_ACQUIRE, GFP_ATOMIC);
}
/* User gives us xfrm_user_policy_info followed by an array of 0
* or more templates.
*/
static struct xfrm_policy *xfrm_compile_policy(u16 family, int opt,
u8 *data, int len, int *dir)
{
struct xfrm_userpolicy_info *p = (struct xfrm_userpolicy_info *)data;
struct xfrm_user_tmpl *ut = (struct xfrm_user_tmpl *) (p + 1);
struct xfrm_policy *xp;
int nr;
switch (family) {
case AF_INET:
if (opt != IP_XFRM_POLICY) {
*dir = -EOPNOTSUPP;
return NULL;
}
break;
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
case AF_INET6:
if (opt != IPV6_XFRM_POLICY) {
*dir = -EOPNOTSUPP;
return NULL;
}
break;
#endif
default:
*dir = -EINVAL;
return NULL;
}
*dir = -EINVAL;
if (len < sizeof(*p) ||
verify_newpolicy_info(p))
return NULL;
nr = ((len - sizeof(*p)) / sizeof(*ut));
if (nr > XFRM_MAX_DEPTH)
return NULL;
if (p->dir > XFRM_POLICY_OUT)
return NULL;
xp = xfrm_policy_alloc(GFP_KERNEL);
if (xp == NULL) {
*dir = -ENOBUFS;
return NULL;
}
copy_from_user_policy(xp, p);
copy_templates(xp, ut, nr);
*dir = p->dir;
return xp;
}
static int build_polexpire(struct sk_buff *skb, struct xfrm_policy *xp,
int dir, int hard)
{
struct xfrm_user_polexpire *upe;
struct nlmsghdr *nlh;
unsigned char *b = skb->tail;
nlh = NLMSG_PUT(skb, 0, 0, XFRM_MSG_POLEXPIRE, sizeof(*upe));
upe = NLMSG_DATA(nlh);
nlh->nlmsg_flags = 0;
copy_to_user_policy(xp, &upe->pol, dir);
if (copy_to_user_tmpl(xp, skb) < 0)
goto nlmsg_failure;
upe->hard = !!hard;
nlh->nlmsg_len = skb->tail - b;
return skb->len;
nlmsg_failure:
skb_trim(skb, b - skb->data);
return -1;
}
static int xfrm_exp_policy_notify(struct xfrm_policy *xp, int dir, struct km_event *c)
{
struct sk_buff *skb;
size_t len;
len = RTA_SPACE(sizeof(struct xfrm_user_tmpl) * xp->xfrm_nr);
len += NLMSG_SPACE(sizeof(struct xfrm_user_polexpire));
skb = alloc_skb(len, GFP_ATOMIC);
if (skb == NULL)
return -ENOMEM;
if (build_polexpire(skb, xp, dir, c->data.hard) < 0)
BUG();
NETLINK_CB(skb).dst_group = XFRMNLGRP_EXPIRE;
return netlink_broadcast(xfrm_nl, skb, 0, XFRMNLGRP_EXPIRE, GFP_ATOMIC);
}
static int xfrm_notify_policy(struct xfrm_policy *xp, int dir, struct km_event *c)
{
struct xfrm_userpolicy_info *p;
struct xfrm_userpolicy_id *id;
struct nlmsghdr *nlh;
struct sk_buff *skb;
unsigned char *b;
int len = RTA_SPACE(sizeof(struct xfrm_user_tmpl) * xp->xfrm_nr);
int headlen;
headlen = sizeof(*p);
if (c->event == XFRM_MSG_DELPOLICY) {
len += RTA_SPACE(headlen);
headlen = sizeof(*id);
}
len += NLMSG_SPACE(headlen);
skb = alloc_skb(len, GFP_ATOMIC);
if (skb == NULL)
return -ENOMEM;
b = skb->tail;
nlh = NLMSG_PUT(skb, c->pid, c->seq, c->event, headlen);
p = NLMSG_DATA(nlh);
if (c->event == XFRM_MSG_DELPOLICY) {
id = NLMSG_DATA(nlh);
memset(id, 0, sizeof(*id));
id->dir = dir;
if (c->data.byid)
id->index = xp->index;
else
memcpy(&id->sel, &xp->selector, sizeof(id->sel));
p = RTA_DATA(__RTA_PUT(skb, XFRMA_POLICY, sizeof(*p)));
}
nlh->nlmsg_flags = 0;
copy_to_user_policy(xp, p, dir);
if (copy_to_user_tmpl(xp, skb) < 0)
goto nlmsg_failure;
nlh->nlmsg_len = skb->tail - b;
NETLINK_CB(skb).dst_group = XFRMNLGRP_POLICY;
return netlink_broadcast(xfrm_nl, skb, 0, XFRMNLGRP_POLICY, GFP_ATOMIC);
nlmsg_failure:
rtattr_failure:
kfree_skb(skb);
return -1;
}
static int xfrm_notify_policy_flush(struct km_event *c)
{
struct nlmsghdr *nlh;
struct sk_buff *skb;
unsigned char *b;
int len = NLMSG_LENGTH(0);
skb = alloc_skb(len, GFP_ATOMIC);
if (skb == NULL)
return -ENOMEM;
b = skb->tail;
nlh = NLMSG_PUT(skb, c->pid, c->seq, XFRM_MSG_FLUSHPOLICY, 0);
nlh->nlmsg_len = skb->tail - b;
NETLINK_CB(skb).dst_group = XFRMNLGRP_POLICY;
return netlink_broadcast(xfrm_nl, skb, 0, XFRMNLGRP_POLICY, GFP_ATOMIC);
nlmsg_failure:
kfree_skb(skb);
return -1;
}
static int xfrm_send_policy_notify(struct xfrm_policy *xp, int dir, struct km_event *c)
{
switch (c->event) {
case XFRM_MSG_NEWPOLICY:
case XFRM_MSG_UPDPOLICY:
case XFRM_MSG_DELPOLICY:
return xfrm_notify_policy(xp, dir, c);
case XFRM_MSG_FLUSHPOLICY:
return xfrm_notify_policy_flush(c);
case XFRM_MSG_POLEXPIRE:
return xfrm_exp_policy_notify(xp, dir, c);
default:
printk("xfrm_user: Unknown Policy event %d\n", c->event);
}
return 0;
}
static struct xfrm_mgr netlink_mgr = {
.id = "netlink",
.notify = xfrm_send_state_notify,
.acquire = xfrm_send_acquire,
.compile_policy = xfrm_compile_policy,
.notify_policy = xfrm_send_policy_notify,
};
static int __init xfrm_user_init(void)
{
printk(KERN_INFO "Initializing IPsec netlink socket\n");
xfrm_nl = netlink_kernel_create(NETLINK_XFRM, XFRMNLGRP_MAX,
xfrm_netlink_rcv, THIS_MODULE);
if (xfrm_nl == NULL)
return -ENOMEM;
xfrm_register_km(&netlink_mgr);
return 0;
}
static void __exit xfrm_user_exit(void)
{
xfrm_unregister_km(&netlink_mgr);
sock_release(xfrm_nl->sk_socket);
}
module_init(xfrm_user_init);
module_exit(xfrm_user_exit);
MODULE_LICENSE("GPL");
MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_XFRM);