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authorJens Axboe <axboe@kernel.dk>2020-02-27 08:11:20 -0700
committerJens Axboe <axboe@kernel.dk>2020-03-10 09:12:49 -0600
commit0a384abfae66651b28e4bbe16883b1ff046ba3b3 (patch)
tree482a79b57843d0a2184ecff7c5535ddf9304a88a
parent4d954c258a0c365a85a2d1b1cccf63aec38fca4c (diff)
downloadlinux-0a384abfae66651b28e4bbe16883b1ff046ba3b3.tar.bz2
net: abstract out normal and compat msghdr import
This splits it into two parts, one that imports the message, and one that imports the iovec. This allows a caller to only do the first part, and import the iovec manually afterwards. No functional changes in this patch. Acked-by: David Miller <davem@davemloft.net> Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--include/linux/socket.h4
-rw-r--r--include/net/compat.h3
-rw-r--r--net/compat.c30
-rw-r--r--net/socket.c25
4 files changed, 51 insertions, 11 deletions
diff --git a/include/linux/socket.h b/include/linux/socket.h
index 2d2313403101..fc59ac825561 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -391,6 +391,10 @@ extern int recvmsg_copy_msghdr(struct msghdr *msg,
struct user_msghdr __user *umsg, unsigned flags,
struct sockaddr __user **uaddr,
struct iovec **iov);
+extern int __copy_msghdr_from_user(struct msghdr *kmsg,
+ struct user_msghdr __user *umsg,
+ struct sockaddr __user **save_addr,
+ struct iovec __user **uiov, size_t *nsegs);
/* helpers which do the actual work for syscalls */
extern int __sys_recvfrom(int fd, void __user *ubuf, size_t size,
diff --git a/include/net/compat.h b/include/net/compat.h
index f277653c7e17..e341260642fe 100644
--- a/include/net/compat.h
+++ b/include/net/compat.h
@@ -38,6 +38,9 @@ struct compat_cmsghdr {
#define compat_mmsghdr mmsghdr
#endif /* defined(CONFIG_COMPAT) */
+int __get_compat_msghdr(struct msghdr *kmsg, struct compat_msghdr __user *umsg,
+ struct sockaddr __user **save_addr, compat_uptr_t *ptr,
+ compat_size_t *len);
int get_compat_msghdr(struct msghdr *, struct compat_msghdr __user *,
struct sockaddr __user **, struct iovec **);
struct sock_fprog __user *get_compat_bpf_fprog(char __user *optval);
diff --git a/net/compat.c b/net/compat.c
index 47d99c784947..4bed96e84d9a 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -33,10 +33,10 @@
#include <linux/uaccess.h>
#include <net/compat.h>
-int get_compat_msghdr(struct msghdr *kmsg,
- struct compat_msghdr __user *umsg,
- struct sockaddr __user **save_addr,
- struct iovec **iov)
+int __get_compat_msghdr(struct msghdr *kmsg,
+ struct compat_msghdr __user *umsg,
+ struct sockaddr __user **save_addr,
+ compat_uptr_t *ptr, compat_size_t *len)
{
struct compat_msghdr msg;
ssize_t err;
@@ -79,10 +79,26 @@ int get_compat_msghdr(struct msghdr *kmsg,
return -EMSGSIZE;
kmsg->msg_iocb = NULL;
+ *ptr = msg.msg_iov;
+ *len = msg.msg_iovlen;
+ return 0;
+}
+
+int get_compat_msghdr(struct msghdr *kmsg,
+ struct compat_msghdr __user *umsg,
+ struct sockaddr __user **save_addr,
+ struct iovec **iov)
+{
+ compat_uptr_t ptr;
+ compat_size_t len;
+ ssize_t err;
+
+ err = __get_compat_msghdr(kmsg, umsg, save_addr, &ptr, &len);
+ if (err)
+ return err;
- err = compat_import_iovec(save_addr ? READ : WRITE,
- compat_ptr(msg.msg_iov), msg.msg_iovlen,
- UIO_FASTIOV, iov, &kmsg->msg_iter);
+ err = compat_import_iovec(save_addr ? READ : WRITE, compat_ptr(ptr),
+ len, UIO_FASTIOV, iov, &kmsg->msg_iter);
return err < 0 ? err : 0;
}
diff --git a/net/socket.c b/net/socket.c
index b79a05de7c6e..70ede74ab24b 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2226,10 +2226,10 @@ struct used_address {
unsigned int name_len;
};
-static int copy_msghdr_from_user(struct msghdr *kmsg,
- struct user_msghdr __user *umsg,
- struct sockaddr __user **save_addr,
- struct iovec **iov)
+int __copy_msghdr_from_user(struct msghdr *kmsg,
+ struct user_msghdr __user *umsg,
+ struct sockaddr __user **save_addr,
+ struct iovec __user **uiov, size_t *nsegs)
{
struct user_msghdr msg;
ssize_t err;
@@ -2271,6 +2271,23 @@ static int copy_msghdr_from_user(struct msghdr *kmsg,
return -EMSGSIZE;
kmsg->msg_iocb = NULL;
+ *uiov = msg.msg_iov;
+ *nsegs = msg.msg_iovlen;
+ return 0;
+}
+
+static int copy_msghdr_from_user(struct msghdr *kmsg,
+ struct user_msghdr __user *umsg,
+ struct sockaddr __user **save_addr,
+ struct iovec **iov)
+{
+ struct user_msghdr msg;
+ ssize_t err;
+
+ err = __copy_msghdr_from_user(kmsg, umsg, save_addr, &msg.msg_iov,
+ &msg.msg_iovlen);
+ if (err)
+ return err;
err = import_iovec(save_addr ? READ : WRITE,
msg.msg_iov, msg.msg_iovlen,