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net: genetlink: push attrbuf allocation and parsing to a separate function 

To be re-usable by dumpit as well, push the code that is taking care of
attrbuf allocation and parting from doit into separate function.
Introduce a helper to free the buffer too.

Check family->maxattr too before calling kfree() to be symmetrical with
the allocation check.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jiri Pirko 2019-10-05 20:04:35 +02:00 committed by David S. Miller
parent 1927f41a22
commit c10e6cf85e
1 changed files with 45 additions and 22 deletions
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67
net/netlink/genetlink.c
View File

@ -468,6 +468,45 @@ static void genl_dumpit_info_free(const struct genl_dumpit_info *info)
kfree(info);
}
static struct nlattr **
genl_family_rcv_msg_attrs_parse(const struct genl_family *family,
struct nlmsghdr *nlh,
struct netlink_ext_ack *extack,
const struct genl_ops *ops,
int hdrlen,
enum genl_validate_flags no_strict_flag)
{
enum netlink_validation validate = ops->validate & no_strict_flag ?
NL_VALIDATE_LIBERAL :
NL_VALIDATE_STRICT;
struct nlattr **attrbuf;
int err;
if (family->maxattr && family->parallel_ops) {
attrbuf = kmalloc_array(family->maxattr + 1,
sizeof(struct nlattr *), GFP_KERNEL);
if (!attrbuf)
return ERR_PTR(-ENOMEM);
} else {
attrbuf = family->attrbuf;
}
err = __nlmsg_parse(nlh, hdrlen, attrbuf, family->maxattr,
family->policy, validate, extack);
if (err && family->maxattr && family->parallel_ops) {
kfree(attrbuf);
return ERR_PTR(err);
}
return attrbuf;
}
static void genl_family_rcv_msg_attrs_free(const struct genl_family *family,
struct nlattr **attrbuf)
{
if (family->maxattr && family->parallel_ops)
kfree(attrbuf);
}
static int genl_lock_start(struct netlink_callback *cb)
{
const struct genl_ops *ops = genl_dumpit_info(cb)->ops;
@ -599,26 +638,11 @@ static int genl_family_rcv_msg_doit(const struct genl_family *family,
if (!ops->doit)
return -EOPNOTSUPP;
if (family->maxattr && family->parallel_ops) {
attrbuf = kmalloc_array(family->maxattr + 1,
sizeof(struct nlattr *),
GFP_KERNEL);
if (attrbuf == NULL)
return -ENOMEM;
} else
attrbuf = family->attrbuf;
if (attrbuf) {
enum netlink_validation validate = NL_VALIDATE_STRICT;
if (ops->validate & GENL_DONT_VALIDATE_STRICT)
validate = NL_VALIDATE_LIBERAL;
err = __nlmsg_parse(nlh, hdrlen, attrbuf, family->maxattr,
family->policy, validate, extack);
if (err < 0)
goto out;
}
attrbuf = genl_family_rcv_msg_attrs_parse(family, nlh, extack,
ops, hdrlen,
GENL_DONT_VALIDATE_STRICT);
if (IS_ERR(attrbuf))
return PTR_ERR(attrbuf);
info.snd_seq = nlh->nlmsg_seq;
info.snd_portid = NETLINK_CB(skb).portid;
@ -642,8 +666,7 @@ static int genl_family_rcv_msg_doit(const struct genl_family *family,
family->post_doit(ops, skb, &info);
out:
if (family->parallel_ops)
kfree(attrbuf);
genl_family_rcv_msg_attrs_free(family, attrbuf);
return err;
}