netfilter: use nfnetlink_unicast()

Replace netlink_unicast() calls by nfnetlink_unicast() which already
deals with translating EAGAIN to ENOBUFS as the nfnetlink core expects.

nfnetlink_unicast() calls nlmsg_unicast() which returns zero in case of
success, otherwise the netlink core function netlink_rcv_skb() turns
err > 0 into an acknowlegment.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Pablo Neira Ayuso 2021-05-17 14:43:08 +02:00
parent 02d8514267
commit e0241ae6ac
5 changed files with 44 additions and 124 deletions

View File

@ -1685,8 +1685,8 @@ static const struct nla_policy ip_set_adt_policy[IPSET_ATTR_CMD_MAX + 1] = {
};
static int
call_ad(struct sock *ctnl, struct sk_buff *skb, struct ip_set *set,
struct nlattr *tb[], enum ipset_adt adt,
call_ad(struct net *net, struct sock *ctnl, struct sk_buff *skb,
struct ip_set *set, struct nlattr *tb[], enum ipset_adt adt,
u32 flags, bool use_lineno)
{
int ret;
@ -1738,8 +1738,7 @@ call_ad(struct sock *ctnl, struct sk_buff *skb, struct ip_set *set,
*errline = lineno;
netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid,
MSG_DONTWAIT);
nfnetlink_unicast(skb2, net, NETLINK_CB(skb).portid);
/* Signal netlink not to send its ACK/errmsg. */
return -EINTR;
}
@ -1783,7 +1782,7 @@ static int ip_set_ad(struct net *net, struct sock *ctnl,
attr[IPSET_ATTR_DATA],
set->type->adt_policy, NULL))
return -IPSET_ERR_PROTOCOL;
ret = call_ad(ctnl, skb, set, tb, adt, flags,
ret = call_ad(net, ctnl, skb, set, tb, adt, flags,
use_lineno);
} else {
int nla_rem;
@ -1794,7 +1793,7 @@ static int ip_set_ad(struct net *net, struct sock *ctnl,
nla_parse_nested(tb, IPSET_ATTR_ADT_MAX, nla,
set->type->adt_policy, NULL))
return -IPSET_ERR_PROTOCOL;
ret = call_ad(ctnl, skb, set, tb, adt,
ret = call_ad(net, ctnl, skb, set, tb, adt,
flags, use_lineno);
if (ret < 0)
return ret;
@ -1859,7 +1858,6 @@ static int ip_set_header(struct sk_buff *skb, const struct nfnl_info *info,
const struct ip_set *set;
struct sk_buff *skb2;
struct nlmsghdr *nlh2;
int ret = 0;
if (unlikely(protocol_min_failed(attr) ||
!attr[IPSET_ATTR_SETNAME]))
@ -1885,12 +1883,7 @@ static int ip_set_header(struct sk_buff *skb, const struct nfnl_info *info,
goto nla_put_failure;
nlmsg_end(skb2, nlh2);
ret = netlink_unicast(info->sk, skb2, NETLINK_CB(skb).portid,
MSG_DONTWAIT);
if (ret < 0)
return ret;
return 0;
return nfnetlink_unicast(skb2, info->net, NETLINK_CB(skb).portid);
nla_put_failure:
nlmsg_cancel(skb2, nlh2);
@ -1945,12 +1938,7 @@ static int ip_set_type(struct sk_buff *skb, const struct nfnl_info *info,
nlmsg_end(skb2, nlh2);
pr_debug("Send TYPE, nlmsg_len: %u\n", nlh2->nlmsg_len);
ret = netlink_unicast(info->sk, skb2, NETLINK_CB(skb).portid,
MSG_DONTWAIT);
if (ret < 0)
return ret;
return 0;
return nfnetlink_unicast(skb2, info->net, NETLINK_CB(skb).portid);
nla_put_failure:
nlmsg_cancel(skb2, nlh2);
@ -1971,7 +1959,6 @@ static int ip_set_protocol(struct sk_buff *skb, const struct nfnl_info *info,
{
struct sk_buff *skb2;
struct nlmsghdr *nlh2;
int ret = 0;
if (unlikely(!attr[IPSET_ATTR_PROTOCOL]))
return -IPSET_ERR_PROTOCOL;
@ -1990,12 +1977,7 @@ static int ip_set_protocol(struct sk_buff *skb, const struct nfnl_info *info,
goto nla_put_failure;
nlmsg_end(skb2, nlh2);
ret = netlink_unicast(info->sk, skb2, NETLINK_CB(skb).portid,
MSG_DONTWAIT);
if (ret < 0)
return ret;
return 0;
return nfnetlink_unicast(skb2, info->net, NETLINK_CB(skb).portid);
nla_put_failure:
nlmsg_cancel(skb2, nlh2);
@ -2014,7 +1996,6 @@ static int ip_set_byname(struct sk_buff *skb, const struct nfnl_info *info,
struct nlmsghdr *nlh2;
ip_set_id_t id = IPSET_INVALID_ID;
const struct ip_set *set;
int ret = 0;
if (unlikely(protocol_failed(attr) ||
!attr[IPSET_ATTR_SETNAME]))
@ -2038,12 +2019,7 @@ static int ip_set_byname(struct sk_buff *skb, const struct nfnl_info *info,
goto nla_put_failure;
nlmsg_end(skb2, nlh2);
ret = netlink_unicast(info->sk, skb2, NETLINK_CB(skb).portid,
MSG_DONTWAIT);
if (ret < 0)
return ret;
return 0;
return nfnetlink_unicast(skb2, info->net, NETLINK_CB(skb).portid);
nla_put_failure:
nlmsg_cancel(skb2, nlh2);
@ -2065,7 +2041,6 @@ static int ip_set_byindex(struct sk_buff *skb, const struct nfnl_info *info,
struct nlmsghdr *nlh2;
ip_set_id_t id = IPSET_INVALID_ID;
const struct ip_set *set;
int ret = 0;
if (unlikely(protocol_failed(attr) ||
!attr[IPSET_ATTR_INDEX]))
@ -2091,12 +2066,7 @@ static int ip_set_byindex(struct sk_buff *skb, const struct nfnl_info *info,
goto nla_put_failure;
nlmsg_end(skb2, nlh2);
ret = netlink_unicast(info->sk, skb2, NETLINK_CB(skb).portid,
MSG_DONTWAIT);
if (ret < 0)
return ret;
return 0;
return nfnetlink_unicast(skb2, info->net, NETLINK_CB(skb).portid);
nla_put_failure:
nlmsg_cancel(skb2, nlh2);

View File

@ -1628,9 +1628,8 @@ static int ctnetlink_get_conntrack(struct sk_buff *skb,
ct = nf_ct_tuplehash_to_ctrack(h);
err = -ENOMEM;
skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (skb2 == NULL) {
if (!skb2) {
nf_ct_put(ct);
return -ENOMEM;
}
@ -1640,21 +1639,12 @@ static int ctnetlink_get_conntrack(struct sk_buff *skb,
NFNL_MSG_TYPE(info->nlh->nlmsg_type), ct,
true, 0);
nf_ct_put(ct);
if (err <= 0)
goto free;
if (err <= 0) {
kfree_skb(skb2);
return -ENOMEM;
}
err = netlink_unicast(info->sk, skb2, NETLINK_CB(skb).portid,
MSG_DONTWAIT);
if (err < 0)
goto out;
return 0;
free:
kfree_skb(skb2);
out:
/* this avoids a loop in nfnetlink. */
return err == -EAGAIN ? -ENOBUFS : err;
return nfnetlink_unicast(skb2, info->net, NETLINK_CB(skb).portid);
}
static int ctnetlink_done_list(struct netlink_callback *cb)
@ -2590,21 +2580,12 @@ static int ctnetlink_stat_ct(struct sk_buff *skb, const struct nfnl_info *info,
info->nlh->nlmsg_seq,
NFNL_MSG_TYPE(info->nlh->nlmsg_type),
sock_net(skb->sk));
if (err <= 0)
goto free;
if (err <= 0) {
kfree_skb(skb2);
return -ENOMEM;
}
err = netlink_unicast(info->sk, skb2, NETLINK_CB(skb).portid,
MSG_DONTWAIT);
if (err < 0)
goto out;
return 0;
free:
kfree_skb(skb2);
out:
/* this avoids a loop in nfnetlink. */
return err == -EAGAIN ? -ENOBUFS : err;
return nfnetlink_unicast(skb2, info->net, NETLINK_CB(skb).portid);
}
static const struct nla_policy exp_nla_policy[CTA_EXPECT_MAX+1] = {
@ -3329,11 +3310,10 @@ static int ctnetlink_get_expect(struct sk_buff *skb,
}
}
err = -ENOMEM;
skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (skb2 == NULL) {
if (!skb2) {
nf_ct_expect_put(exp);
goto out;
return -ENOMEM;
}
rcu_read_lock();
@ -3342,21 +3322,12 @@ static int ctnetlink_get_expect(struct sk_buff *skb,
exp);
rcu_read_unlock();
nf_ct_expect_put(exp);
if (err <= 0)
goto free;
if (err <= 0) {
kfree_skb(skb2);
return -ENOMEM;
}
err = netlink_unicast(info->sk, skb2, NETLINK_CB(skb).portid,
MSG_DONTWAIT);
if (err < 0)
goto out;
return 0;
free:
kfree_skb(skb2);
out:
/* this avoids a loop in nfnetlink. */
return err == -EAGAIN ? -ENOBUFS : err;
return nfnetlink_unicast(skb2, info->net, NETLINK_CB(skb).portid);
}
static bool expect_iter_name(struct nf_conntrack_expect *exp, void *data)

View File

@ -314,14 +314,11 @@ static int nfnl_acct_get(struct sk_buff *skb, const struct nfnl_info *info,
kfree_skb(skb2);
break;
}
ret = netlink_unicast(info->sk, skb2, NETLINK_CB(skb).portid,
MSG_DONTWAIT);
if (ret > 0)
ret = 0;
/* this avoids a loop in nfnetlink. */
return ret == -EAGAIN ? -ENOBUFS : ret;
ret = nfnetlink_unicast(skb2, info->net, NETLINK_CB(skb).portid);
break;
}
return ret;
}

View File

@ -663,14 +663,10 @@ static int nfnl_cthelper_get(struct sk_buff *skb, const struct nfnl_info *info,
break;
}
ret = netlink_unicast(info->sk, skb2, NETLINK_CB(skb).portid,
MSG_DONTWAIT);
if (ret > 0)
ret = 0;
/* this avoids a loop in nfnetlink. */
return ret == -EAGAIN ? -ENOBUFS : ret;
ret = nfnetlink_unicast(skb2, info->net, NETLINK_CB(skb).portid);
break;
}
return ret;
}

View File

@ -287,14 +287,11 @@ static int cttimeout_get_timeout(struct sk_buff *skb,
kfree_skb(skb2);
break;
}
ret = netlink_unicast(info->sk, skb2, NETLINK_CB(skb).portid,
MSG_DONTWAIT);
if (ret > 0)
ret = 0;
/* this avoids a loop in nfnetlink. */
return ret == -EAGAIN ? -ENOBUFS : ret;
ret = nfnetlink_unicast(skb2, info->net, NETLINK_CB(skb).portid);
break;
}
return ret;
}
@ -427,9 +424,9 @@ static int cttimeout_default_get(struct sk_buff *skb,
const struct nf_conntrack_l4proto *l4proto;
unsigned int *timeouts = NULL;
struct sk_buff *skb2;
int ret, err;
__u16 l3num;
__u8 l4num;
int ret;
if (!cda[CTA_TIMEOUT_L3PROTO] || !cda[CTA_TIMEOUT_L4PROTO])
return -EINVAL;
@ -438,9 +435,8 @@ static int cttimeout_default_get(struct sk_buff *skb,
l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
l4proto = nf_ct_l4proto_find(l4num);
err = -EOPNOTSUPP;
if (l4proto->l4proto != l4num)
goto err;
return -EOPNOTSUPP;
switch (l4proto->l4proto) {
case IPPROTO_ICMP:
@ -480,13 +476,11 @@ static int cttimeout_default_get(struct sk_buff *skb,
}
if (!timeouts)
goto err;
return -EOPNOTSUPP;
skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (skb2 == NULL) {
err = -ENOMEM;
goto err;
}
if (!skb2)
return -ENOMEM;
ret = cttimeout_default_fill_info(info->net, skb2,
NETLINK_CB(skb).portid,
@ -496,18 +490,10 @@ static int cttimeout_default_get(struct sk_buff *skb,
l3num, l4proto, timeouts);
if (ret <= 0) {
kfree_skb(skb2);
err = -ENOMEM;
goto err;
return -ENOMEM;
}
ret = netlink_unicast(info->sk, skb2, NETLINK_CB(skb).portid,
MSG_DONTWAIT);
if (ret > 0)
ret = 0;
/* this avoids a loop in nfnetlink. */
return ret == -EAGAIN ? -ENOBUFS : ret;
err:
return err;
return nfnetlink_unicast(skb2, info->net, NETLINK_CB(skb).portid);
}
static struct nf_ct_timeout *ctnl_timeout_find_get(struct net *net,