Merge branch 'net-more-heap-allocation-and-split-of-rtnl_newlink'

Jakub Kicinski says:

====================
net: more heap allocation and split of rtnl_newlink()

Small refactoring of rtnl_newlink() to fix a stack usage warning
and make the function shorter.
====================

Link: https://lore.kernel.org/r/20220429235508.268349-1-kuba@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This commit is contained in:
Paolo Abeni 2022-05-02 15:14:22 +02:00
commit 0decb97cb1

View File

@ -3302,182 +3302,18 @@ static int rtnl_group_changelink(const struct sk_buff *skb,
return 0;
}
static int __rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh,
struct nlattr **attr, struct netlink_ext_ack *extack)
static int rtnl_newlink_create(struct sk_buff *skb, struct ifinfomsg *ifm,
const struct rtnl_link_ops *ops,
struct nlattr **tb, struct nlattr **data,
struct netlink_ext_ack *extack)
{
struct nlattr *slave_attr[RTNL_SLAVE_MAX_TYPE + 1];
unsigned char name_assign_type = NET_NAME_USER;
struct nlattr *linkinfo[IFLA_INFO_MAX + 1];
const struct rtnl_link_ops *m_ops;
struct net_device *master_dev;
struct net *net = sock_net(skb->sk);
const struct rtnl_link_ops *ops;
struct nlattr *tb[IFLA_MAX + 1];
struct net *dest_net, *link_net;
struct nlattr **slave_data;
char kind[MODULE_NAME_LEN];
struct net_device *dev;
struct ifinfomsg *ifm;
char ifname[IFNAMSIZ];
struct nlattr **data;
bool link_specified;
int err;
#ifdef CONFIG_MODULES
replay:
#endif
err = nlmsg_parse_deprecated(nlh, sizeof(*ifm), tb, IFLA_MAX,
ifla_policy, extack);
if (err < 0)
return err;
err = rtnl_ensure_unique_netns(tb, extack, false);
if (err < 0)
return err;
ifm = nlmsg_data(nlh);
if (ifm->ifi_index > 0) {
link_specified = true;
dev = __dev_get_by_index(net, ifm->ifi_index);
} else if (tb[IFLA_IFNAME] || tb[IFLA_ALT_IFNAME]) {
link_specified = true;
dev = rtnl_dev_get(net, tb);
} else {
link_specified = false;
dev = NULL;
}
master_dev = NULL;
m_ops = NULL;
if (dev) {
master_dev = netdev_master_upper_dev_get(dev);
if (master_dev)
m_ops = master_dev->rtnl_link_ops;
}
err = validate_linkmsg(dev, tb, extack);
if (err < 0)
return err;
if (tb[IFLA_LINKINFO]) {
err = nla_parse_nested_deprecated(linkinfo, IFLA_INFO_MAX,
tb[IFLA_LINKINFO],
ifla_info_policy, NULL);
if (err < 0)
return err;
} else
memset(linkinfo, 0, sizeof(linkinfo));
if (linkinfo[IFLA_INFO_KIND]) {
nla_strscpy(kind, linkinfo[IFLA_INFO_KIND], sizeof(kind));
ops = rtnl_link_ops_get(kind);
} else {
kind[0] = '\0';
ops = NULL;
}
data = NULL;
if (ops) {
if (ops->maxtype > RTNL_MAX_TYPE)
return -EINVAL;
if (ops->maxtype && linkinfo[IFLA_INFO_DATA]) {
err = nla_parse_nested_deprecated(attr, ops->maxtype,
linkinfo[IFLA_INFO_DATA],
ops->policy, extack);
if (err < 0)
return err;
data = attr;
}
if (ops->validate) {
err = ops->validate(tb, data, extack);
if (err < 0)
return err;
}
}
slave_data = NULL;
if (m_ops) {
if (m_ops->slave_maxtype > RTNL_SLAVE_MAX_TYPE)
return -EINVAL;
if (m_ops->slave_maxtype &&
linkinfo[IFLA_INFO_SLAVE_DATA]) {
err = nla_parse_nested_deprecated(slave_attr,
m_ops->slave_maxtype,
linkinfo[IFLA_INFO_SLAVE_DATA],
m_ops->slave_policy,
extack);
if (err < 0)
return err;
slave_data = slave_attr;
}
}
if (dev) {
int status = 0;
if (nlh->nlmsg_flags & NLM_F_EXCL)
return -EEXIST;
if (nlh->nlmsg_flags & NLM_F_REPLACE)
return -EOPNOTSUPP;
if (linkinfo[IFLA_INFO_DATA]) {
if (!ops || ops != dev->rtnl_link_ops ||
!ops->changelink)
return -EOPNOTSUPP;
err = ops->changelink(dev, tb, data, extack);
if (err < 0)
return err;
status |= DO_SETLINK_NOTIFY;
}
if (linkinfo[IFLA_INFO_SLAVE_DATA]) {
if (!m_ops || !m_ops->slave_changelink)
return -EOPNOTSUPP;
err = m_ops->slave_changelink(master_dev, dev, tb,
slave_data, extack);
if (err < 0)
return err;
status |= DO_SETLINK_NOTIFY;
}
return do_setlink(skb, dev, ifm, extack, tb, status);
}
if (!(nlh->nlmsg_flags & NLM_F_CREATE)) {
/* No dev found and NLM_F_CREATE not set. Requested dev does not exist,
* or it's for a group
*/
if (link_specified)
return -ENODEV;
if (tb[IFLA_GROUP])
return rtnl_group_changelink(skb, net,
nla_get_u32(tb[IFLA_GROUP]),
ifm, extack, tb);
return -ENODEV;
}
if (tb[IFLA_MAP] || tb[IFLA_PROTINFO])
return -EOPNOTSUPP;
if (!ops) {
#ifdef CONFIG_MODULES
if (kind[0]) {
__rtnl_unlock();
request_module("rtnl-link-%s", kind);
rtnl_lock();
ops = rtnl_link_ops_get(kind);
if (ops)
goto replay;
}
#endif
NL_SET_ERR_MSG(extack, "Unknown device type");
return -EOPNOTSUPP;
}
if (!ops->alloc && !ops->setup)
return -EOPNOTSUPP;
@ -3556,18 +3392,200 @@ out_unregister:
goto out;
}
struct rtnl_newlink_tbs {
struct nlattr *tb[IFLA_MAX + 1];
struct nlattr *attr[RTNL_MAX_TYPE + 1];
struct nlattr *slave_attr[RTNL_SLAVE_MAX_TYPE + 1];
};
static int __rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh,
struct rtnl_newlink_tbs *tbs,
struct netlink_ext_ack *extack)
{
struct nlattr *linkinfo[IFLA_INFO_MAX + 1];
struct nlattr ** const tb = tbs->tb;
const struct rtnl_link_ops *m_ops;
struct net_device *master_dev;
struct net *net = sock_net(skb->sk);
const struct rtnl_link_ops *ops;
struct nlattr **slave_data;
char kind[MODULE_NAME_LEN];
struct net_device *dev;
struct ifinfomsg *ifm;
struct nlattr **data;
bool link_specified;
int err;
#ifdef CONFIG_MODULES
replay:
#endif
err = nlmsg_parse_deprecated(nlh, sizeof(*ifm), tb, IFLA_MAX,
ifla_policy, extack);
if (err < 0)
return err;
err = rtnl_ensure_unique_netns(tb, extack, false);
if (err < 0)
return err;
ifm = nlmsg_data(nlh);
if (ifm->ifi_index > 0) {
link_specified = true;
dev = __dev_get_by_index(net, ifm->ifi_index);
} else if (tb[IFLA_IFNAME] || tb[IFLA_ALT_IFNAME]) {
link_specified = true;
dev = rtnl_dev_get(net, tb);
} else {
link_specified = false;
dev = NULL;
}
master_dev = NULL;
m_ops = NULL;
if (dev) {
master_dev = netdev_master_upper_dev_get(dev);
if (master_dev)
m_ops = master_dev->rtnl_link_ops;
}
err = validate_linkmsg(dev, tb, extack);
if (err < 0)
return err;
if (tb[IFLA_LINKINFO]) {
err = nla_parse_nested_deprecated(linkinfo, IFLA_INFO_MAX,
tb[IFLA_LINKINFO],
ifla_info_policy, NULL);
if (err < 0)
return err;
} else
memset(linkinfo, 0, sizeof(linkinfo));
if (linkinfo[IFLA_INFO_KIND]) {
nla_strscpy(kind, linkinfo[IFLA_INFO_KIND], sizeof(kind));
ops = rtnl_link_ops_get(kind);
} else {
kind[0] = '\0';
ops = NULL;
}
data = NULL;
if (ops) {
if (ops->maxtype > RTNL_MAX_TYPE)
return -EINVAL;
if (ops->maxtype && linkinfo[IFLA_INFO_DATA]) {
err = nla_parse_nested_deprecated(tbs->attr, ops->maxtype,
linkinfo[IFLA_INFO_DATA],
ops->policy, extack);
if (err < 0)
return err;
data = tbs->attr;
}
if (ops->validate) {
err = ops->validate(tb, data, extack);
if (err < 0)
return err;
}
}
slave_data = NULL;
if (m_ops) {
if (m_ops->slave_maxtype > RTNL_SLAVE_MAX_TYPE)
return -EINVAL;
if (m_ops->slave_maxtype &&
linkinfo[IFLA_INFO_SLAVE_DATA]) {
err = nla_parse_nested_deprecated(tbs->slave_attr,
m_ops->slave_maxtype,
linkinfo[IFLA_INFO_SLAVE_DATA],
m_ops->slave_policy,
extack);
if (err < 0)
return err;
slave_data = tbs->slave_attr;
}
}
if (dev) {
int status = 0;
if (nlh->nlmsg_flags & NLM_F_EXCL)
return -EEXIST;
if (nlh->nlmsg_flags & NLM_F_REPLACE)
return -EOPNOTSUPP;
if (linkinfo[IFLA_INFO_DATA]) {
if (!ops || ops != dev->rtnl_link_ops ||
!ops->changelink)
return -EOPNOTSUPP;
err = ops->changelink(dev, tb, data, extack);
if (err < 0)
return err;
status |= DO_SETLINK_NOTIFY;
}
if (linkinfo[IFLA_INFO_SLAVE_DATA]) {
if (!m_ops || !m_ops->slave_changelink)
return -EOPNOTSUPP;
err = m_ops->slave_changelink(master_dev, dev, tb,
slave_data, extack);
if (err < 0)
return err;
status |= DO_SETLINK_NOTIFY;
}
return do_setlink(skb, dev, ifm, extack, tb, status);
}
if (!(nlh->nlmsg_flags & NLM_F_CREATE)) {
/* No dev found and NLM_F_CREATE not set. Requested dev does not exist,
* or it's for a group
*/
if (link_specified)
return -ENODEV;
if (tb[IFLA_GROUP])
return rtnl_group_changelink(skb, net,
nla_get_u32(tb[IFLA_GROUP]),
ifm, extack, tb);
return -ENODEV;
}
if (tb[IFLA_MAP] || tb[IFLA_PROTINFO])
return -EOPNOTSUPP;
if (!ops) {
#ifdef CONFIG_MODULES
if (kind[0]) {
__rtnl_unlock();
request_module("rtnl-link-%s", kind);
rtnl_lock();
ops = rtnl_link_ops_get(kind);
if (ops)
goto replay;
}
#endif
NL_SET_ERR_MSG(extack, "Unknown device type");
return -EOPNOTSUPP;
}
return rtnl_newlink_create(skb, ifm, ops, tb, data, extack);
}
static int rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
struct nlattr **attr;
struct rtnl_newlink_tbs *tbs;
int ret;
attr = kmalloc_array(RTNL_MAX_TYPE + 1, sizeof(*attr), GFP_KERNEL);
if (!attr)
tbs = kmalloc(sizeof(*tbs), GFP_KERNEL);
if (!tbs)
return -ENOMEM;
ret = __rtnl_newlink(skb, nlh, attr, extack);
kfree(attr);
ret = __rtnl_newlink(skb, nlh, tbs, extack);
kfree(tbs);
return ret;
}