[PATCH 15/26] net/ipv4: merge ip_options_get and ip_options_get_from_user

From: Christoph Hellwig
Date: Thu Jul 23 2020 - 02:09:59 EST


Use the sockptr_t type to merge the versions.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
include/net/ip.h | 5 ++---
net/ipv4/ip_options.c | 43 +++++++++++-------------------------------
net/ipv4/ip_sockglue.c | 7 ++++---
3 files changed, 17 insertions(+), 38 deletions(-)

diff --git a/include/net/ip.h b/include/net/ip.h
index 3d34acc95ca825..d66ad3a9522081 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -23,6 +23,7 @@
#include <linux/in.h>
#include <linux/skbuff.h>
#include <linux/jhash.h>
+#include <linux/sockptr.h>

#include <net/inet_sock.h>
#include <net/route.h>
@@ -707,9 +708,7 @@ int __ip_options_compile(struct net *net, struct ip_options *opt,
int ip_options_compile(struct net *net, struct ip_options *opt,
struct sk_buff *skb);
int ip_options_get(struct net *net, struct ip_options_rcu **optp,
- unsigned char *data, int optlen);
-int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
- unsigned char __user *data, int optlen);
+ sockptr_t data, int optlen);
void ip_options_undo(struct ip_options *opt);
void ip_forward_options(struct sk_buff *skb);
int ip_options_rcv_srr(struct sk_buff *skb, struct net_device *dev);
diff --git a/net/ipv4/ip_options.c b/net/ipv4/ip_options.c
index ddaa01ec2bce82..948747aac4e2d0 100644
--- a/net/ipv4/ip_options.c
+++ b/net/ipv4/ip_options.c
@@ -519,15 +519,20 @@ void ip_options_undo(struct ip_options *opt)
}
}

-static struct ip_options_rcu *ip_options_get_alloc(const int optlen)
+int ip_options_get(struct net *net, struct ip_options_rcu **optp,
+ sockptr_t data, int optlen)
{
- return kzalloc(sizeof(struct ip_options_rcu) + ((optlen + 3) & ~3),
+ struct ip_options_rcu *opt;
+
+ opt = kzalloc(sizeof(struct ip_options_rcu) + ((optlen + 3) & ~3),
GFP_KERNEL);
-}
+ if (!opt)
+ return -ENOMEM;
+ if (optlen && copy_from_sockptr(opt->opt.__data, data, optlen)) {
+ kfree(opt);
+ return -EFAULT;
+ }

-static int ip_options_get_finish(struct net *net, struct ip_options_rcu **optp,
- struct ip_options_rcu *opt, int optlen)
-{
while (optlen & 3)
opt->opt.__data[optlen++] = IPOPT_END;
opt->opt.optlen = optlen;
@@ -540,32 +545,6 @@ static int ip_options_get_finish(struct net *net, struct ip_options_rcu **optp,
return 0;
}

-int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
- unsigned char __user *data, int optlen)
-{
- struct ip_options_rcu *opt = ip_options_get_alloc(optlen);
-
- if (!opt)
- return -ENOMEM;
- if (optlen && copy_from_user(opt->opt.__data, data, optlen)) {
- kfree(opt);
- return -EFAULT;
- }
- return ip_options_get_finish(net, optp, opt, optlen);
-}
-
-int ip_options_get(struct net *net, struct ip_options_rcu **optp,
- unsigned char *data, int optlen)
-{
- struct ip_options_rcu *opt = ip_options_get_alloc(optlen);
-
- if (!opt)
- return -ENOMEM;
- if (optlen)
- memcpy(opt->opt.__data, data, optlen);
- return ip_options_get_finish(net, optp, opt, optlen);
-}
-
void ip_forward_options(struct sk_buff *skb)
{
struct ip_options *opt = &(IPCB(skb)->opt);
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index ac495b0cff8ffb..b12f39b52008a3 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -280,7 +280,8 @@ int ip_cmsg_send(struct sock *sk, struct msghdr *msg, struct ipcm_cookie *ipc,
err = cmsg->cmsg_len - sizeof(struct cmsghdr);

/* Our caller is responsible for freeing ipc->opt */
- err = ip_options_get(net, &ipc->opt, CMSG_DATA(cmsg),
+ err = ip_options_get(net, &ipc->opt,
+ KERNEL_SOCKPTR(CMSG_DATA(cmsg)),
err < 40 ? err : 40);
if (err)
return err;
@@ -940,8 +941,8 @@ static int do_ip_setsockopt(struct sock *sk, int level,

if (optlen > 40)
goto e_inval;
- err = ip_options_get_from_user(sock_net(sk), &opt,
- optval, optlen);
+ err = ip_options_get(sock_net(sk), &opt, USER_SOCKPTR(optval),
+ optlen);
if (err)
break;
old = rcu_dereference_protected(inet->inet_opt,
--
2.27.0