[IP]: Introduce ip_options_get_from_user

This variant is needed to satisfy sparse __user annotations.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 40 insertions, 18 deletions

diff --git a/include/net/ip.h b/include/net/ip.h
index 7623e414a5fb..e4563bbee6ea 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -335,7 +335,10 @@ extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, u32 da
 extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb);
 extern void ip_options_fragment(struct sk_buff *skb);
 extern int ip_options_compile(struct ip_options *opt, struct sk_buff *skb);
-extern int ip_options_get(struct ip_options **optp, unsigned char *data, int optlen, int user);
+extern int ip_options_get(struct ip_options **optp,
+                          unsigned char *data, int optlen);
+extern int ip_options_get_from_user(struct ip_options **optp,
+                                    unsigned char __user *data, int optlen);
 extern void ip_options_undo(struct ip_options * opt);
 extern void ip_forward_options(struct sk_buff *skb);
 extern int ip_options_rcv_srr(struct sk_buff *skb);
diff --git a/net/ipv4/ip_options.c b/net/ipv4/ip_options.c
index 7e02ba584079..bce4e875193b 100644
--- a/net/ipv4/ip_options.c
+++ b/net/ipv4/ip_options.c
@@ -489,23 +489,18 @@ void ip_options_undo(struct ip_options * opt)
         }
 }
 
-int ip_options_get(struct ip_options **optp, unsigned char *data, int optlen, int user)
+static struct ip_options *ip_options_get_alloc(const int optlen)
 {
-        struct ip_options *opt;
+        struct ip_options *opt = kmalloc(sizeof(*opt) + ((optlen + 3) & ~3),
+                                         GFP_KERNEL);
+        if (opt)
+                memset(opt, 0, sizeof(*opt));
+        return opt;
+}
 
-        opt = kmalloc(sizeof(struct ip_options)+((optlen+3)&~3), GFP_KERNEL);
-        if (!opt)
-                return -ENOMEM;
-        memset(opt, 0, sizeof(struct ip_options));
-        if (optlen) {
-                if (user) {
-                        if (copy_from_user(opt->__data, data, optlen)) {
-                                kfree(opt);
-                                return -EFAULT;
-                        }
-                } else
-                        memcpy(opt->__data, data, optlen);
-        }
+static int ip_options_get_finish(struct ip_options **optp,
+                                 struct ip_options *opt, int optlen)
+{
         while (optlen & 3)
                 opt->__data[optlen++] = IPOPT_END;
         opt->optlen = optlen;
@@ -521,6 +516,30 @@ int ip_options_get(struct ip_options **optp, unsigned char *data, int optlen, in
         return 0;
 }
 
+int ip_options_get_from_user(struct ip_options **optp, unsigned char __user *data, int optlen)
+{
+        struct ip_options *opt = ip_options_get_alloc(optlen);
+
+        if (!opt)
+                return -ENOMEM;
+        if (optlen && copy_from_user(opt->__data, data, optlen)) {
+                kfree(opt);
+                return -EFAULT;
+        }
+        return ip_options_get_finish(optp, opt, optlen);
+}
+
+int ip_options_get(struct ip_options **optp, unsigned char *data, int optlen)
+{
+        struct ip_options *opt = ip_options_get_alloc(optlen);
+
+        if (!opt)
+                return -ENOMEM;
+        if (optlen)
+                memcpy(opt->__data, data, optlen);
+        return ip_options_get_finish(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 aca088b3707a..2f0b47da5b37 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -153,7 +153,7 @@ int ip_cmsg_send(struct msghdr *msg, struct ipcm_cookie *ipc)
                 switch (cmsg->cmsg_type) {
                 case IP_RETOPTS:
                         err = cmsg->cmsg_len - CMSG_ALIGN(sizeof(struct cmsghdr));
-                        err = ip_options_get(&ipc->opt, CMSG_DATA(cmsg), err < 40 ? err : 40, 0);
+                        err = ip_options_get(&ipc->opt, CMSG_DATA(cmsg), err < 40 ? err : 40);
                         if (err)
                                 return err;
                         break;
@@ -425,7 +425,7 @@ int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
                         struct ip_options * opt = NULL;
                         if (optlen > 40 || optlen < 0)
                                 goto e_inval;
-                        err = ip_options_get(&opt, optval, optlen, 1);
+                        err = ip_options_get_from_user(&opt, optval, optlen);
                         if (err)
                                 break;
                         if (sk->sk_type == SOCK_STREAM) {