[MPTCP] [PATCH 14/24] net/ipv4: merge ip_options_get and ip_options_get_from_user

From: Christoph Hellwig <hch at lst.de>
To: mptcp at lists.01.org
Subject: [MPTCP] [PATCH 14/24] net/ipv4: merge ip_options_get and ip_options_get_from_user
Date: Mon, 20 Jul 2020 14:47:27 +0200	[thread overview]
Message-ID: <20200720124737.118617-15-hch@lst.de> (raw)
In-Reply-To: 20200720124737.118617-1-hch@lst.de

[-- Attachment #1: Type: text/plain, Size: 4188 bytes --]

Use the sockptr_t type to merge the versions.

Signed-off-by: Christoph Hellwig <hch(a)lst.de>
---
 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
