Commit 0a384abf authored by Jens Axboe's avatar Jens Axboe
Browse files

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: default avatarDavid Miller <davem@davemloft.net>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 4d954c25

include/linux/socket.h

+4 −0
Original line number Diff line number Diff line
@@ -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,

include/net/compat.h

+3 −0
Original line number Diff line number Diff line
@@ -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);

net/compat.c

+23 −7
Original line number Diff line number Diff line
@@ -33,10 +33,10 @@ 
#include <linux/uaccess.h>

#include <net/compat.h>



int get_compat_msghdr(struct msghdr *kmsg,

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)

{

	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;

}

net/socket.c

+21 −4
Original line number Diff line number Diff line
@@ -2226,10 +2226,10 @@ struct used_address { 
	unsigned int name_len;

};



static int copy_msghdr_from_user(struct msghdr *kmsg,

int __copy_msghdr_from_user(struct msghdr *kmsg,

			    struct user_msghdr __user *umsg,

			    struct sockaddr __user **save_addr,

				 struct iovec **iov)

			    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,