net/scm: cleanup scm_detach_fds (2618d530) · Commits · 戴 / test

net/core/scm.c

+51 −43

Original line number	Diff line number	Diff line
		@@ -277,59 +277,66 @@ void put_cmsg_scm_timestamping(struct msghdr *msg, struct scm_timestamping_inter
		}
		EXPORT_SYMBOL(put_cmsg_scm_timestamping);

		void scm_detach_fds(struct msghdr msg, struct scm_cookie scm)
		static int __scm_install_fd(struct file file, int __user ufd, int o_flags)
		{
		struct cmsghdr __user *cm
		= (__force struct cmsghdr __user*)msg->msg_control;

		int fdmax = 0;
		int fdnum = scm->fp->count;
		struct file **fp = scm->fp->fp;
		int __user *cmfptr;
		int err = 0, i;

		if (MSG_CMSG_COMPAT & msg->msg_flags) {
		scm_detach_fds_compat(msg, scm);
		return;
		}
		struct socket *sock;
		int new_fd;
		int error;

		if (msg->msg_controllen > sizeof(struct cmsghdr))
		fdmax = ((msg->msg_controllen - sizeof(struct cmsghdr))
		/ sizeof(int));
		error = security_file_receive(file);
		if (error)
		return error;

		if (fdnum < fdmax)
		fdmax = fdnum;
		new_fd = get_unused_fd_flags(o_flags);
		if (new_fd < 0)
		return new_fd;

		for (i=0, cmfptr =(int __user *)CMSG_USER_DATA(cm); i<fdmax;
		i++, cmfptr++)
		{
		struct socket *sock;
		int new_fd;
		err = security_file_receive(fp[i]);
		if (err)
		break;
		err = get_unused_fd_flags(MSG_CMSG_CLOEXEC & msg->msg_flags
		? O_CLOEXEC : 0);
		if (err < 0)
		break;
		new_fd = err;
		err = put_user(new_fd, cmfptr);
		if (err) {
		error = put_user(new_fd, ufd);
		if (error) {
		put_unused_fd(new_fd);
		break;
		return error;
		}

		/* Bump the usage count and install the file. */
		sock = sock_from_file(fp[i], &err);
		sock = sock_from_file(file, &error);
		if (sock) {
		sock_update_netprioidx(&sock->sk->sk_cgrp_data);
		sock_update_classid(&sock->sk->sk_cgrp_data);
		}
		fd_install(new_fd, get_file(fp[i]));
		fd_install(new_fd, get_file(file));
		return error;
		}

		if (i > 0)
		static int scm_max_fds(struct msghdr *msg)
		{
		if (msg->msg_controllen <= sizeof(struct cmsghdr))
		return 0;
		return (msg->msg_controllen - sizeof(struct cmsghdr)) / sizeof(int);
		}

		void scm_detach_fds(struct msghdr msg, struct scm_cookie scm)
		{
		struct cmsghdr __user *cm
		= (__force struct cmsghdr __user*)msg->msg_control;
		int o_flags = (msg->msg_flags & MSG_CMSG_CLOEXEC) ? O_CLOEXEC : 0;
		int fdmax = min_t(int, scm_max_fds(msg), scm->fp->count);
		int __user *cmsg_data = CMSG_USER_DATA(cm);
		int err = 0, i;

		if (msg->msg_flags & MSG_CMSG_COMPAT) {
		scm_detach_fds_compat(msg, scm);
		return;
		}

		for (i = 0; i < fdmax; i++) {
		err = __scm_install_fd(scm->fp->fp[i], cmsg_data + i, o_flags);
		if (err)
		break;
		}

		if (i > 0) {
		int cmlen = CMSG_LEN(i * sizeof(int));

		err = put_user(SOL_SOCKET, &cm->cmsg_level);
		if (!err)
		err = put_user(SCM_RIGHTS, &cm->cmsg_type);
		@@ -343,12 +350,13 @@ void scm_detach_fds(struct msghdr msg, struct scm_cookie scm)
		msg->msg_controllen -= cmlen;
		}
		}
		if (i < fdnum \|\| (fdnum && fdmax <= 0))

		if (i < scm->fp->count \|\| (scm->fp->count && fdmax <= 0))
		msg->msg_flags \|= MSG_CTRUNC;

		/*
		* All of the files that fit in the message have had their
		* usage counts incremented, so we just free the list.
		* All of the files that fit in the message have had their usage counts
		* incremented, so we just free the list.
		*/
		__scm_destroy(scm);
		}

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