diff options
| -rw-r--r-- | net/qrtr/Kconfig | 7 | ||||
| -rw-r--r-- | net/qrtr/Makefile | 2 | ||||
| -rw-r--r-- | net/qrtr/tun.c | 161 |
3 files changed, 170 insertions, 0 deletions
diff --git a/net/qrtr/Kconfig b/net/qrtr/Kconfig index 326fd97444f5..1944834d225c 100644 --- a/net/qrtr/Kconfig +++ b/net/qrtr/Kconfig @@ -21,4 +21,11 @@ config QRTR_SMD Say Y here to support SMD based ipcrouter channels. SMD is the most common transport for IPC Router. +config QRTR_TUN + tristate "TUN device for Qualcomm IPC Router" + ---help--- + Say Y here to expose a character device that allows user space to + implement endpoints of QRTR, for purpose of tunneling data to other + hosts or testing purposes. + endif # QRTR diff --git a/net/qrtr/Makefile b/net/qrtr/Makefile index ab09e40f7c74..be012bfd3e52 100644 --- a/net/qrtr/Makefile +++ b/net/qrtr/Makefile @@ -2,3 +2,5 @@ obj-$(CONFIG_QRTR) := qrtr.o obj-$(CONFIG_QRTR_SMD) += qrtr-smd.o qrtr-smd-y := smd.o +obj-$(CONFIG_QRTR_TUN) += qrtr-tun.o +qrtr-tun-y := tun.o diff --git a/net/qrtr/tun.c b/net/qrtr/tun.c new file mode 100644 index 000000000000..ccff1e544c21 --- /dev/null +++ b/net/qrtr/tun.c @@ -0,0 +1,161 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2018, Linaro Ltd */ + +#include <linux/miscdevice.h> +#include <linux/module.h> +#include <linux/poll.h> +#include <linux/skbuff.h> +#include <linux/uaccess.h> + +#include "qrtr.h" + +struct qrtr_tun { + struct qrtr_endpoint ep; + + struct sk_buff_head queue; + wait_queue_head_t readq; +}; + +static int qrtr_tun_send(struct qrtr_endpoint *ep, struct sk_buff *skb) +{ + struct qrtr_tun *tun = container_of(ep, struct qrtr_tun, ep); + + skb_queue_tail(&tun->queue, skb); + + /* wake up any blocking processes, waiting for new data */ + wake_up_interruptible(&tun->readq); + + return 0; +} + +static int qrtr_tun_open(struct inode *inode, struct file *filp) +{ + struct qrtr_tun *tun; + + tun = kzalloc(sizeof(*tun), GFP_KERNEL); + if (!tun) + return -ENOMEM; + + skb_queue_head_init(&tun->queue); + init_waitqueue_head(&tun->readq); + + tun->ep.xmit = qrtr_tun_send; + + filp->private_data = tun; + + return qrtr_endpoint_register(&tun->ep, QRTR_EP_NID_AUTO); +} + +static ssize_t qrtr_tun_read_iter(struct kiocb *iocb, struct iov_iter *to) +{ + struct file *filp = iocb->ki_filp; + struct qrtr_tun *tun = filp->private_data; + struct sk_buff *skb; + int count; + + while (!(skb = skb_dequeue(&tun->queue))) { + if (filp->f_flags & O_NONBLOCK) + return -EAGAIN; + + /* Wait until we get data or the endpoint goes away */ + if (wait_event_interruptible(tun->readq, + !skb_queue_empty(&tun->queue))) + return -ERESTARTSYS; + } + + count = min_t(size_t, iov_iter_count(to), skb->len); + if (copy_to_iter(skb->data, count, to) != count) + count = -EFAULT; + + kfree_skb(skb); + + return count; +} + +static ssize_t qrtr_tun_write_iter(struct kiocb *iocb, struct iov_iter *from) +{ + struct file *filp = iocb->ki_filp; + struct qrtr_tun *tun = filp->private_data; + size_t len = iov_iter_count(from); + ssize_t ret; + void *kbuf; + + kbuf = kzalloc(len, GFP_KERNEL); + if (!kbuf) + return -ENOMEM; + + if (!copy_from_iter_full(kbuf, len, from)) + return -EFAULT; + + ret = qrtr_endpoint_post(&tun->ep, kbuf, len); + + return ret < 0 ? ret : len; +} + +static __poll_t qrtr_tun_poll(struct file *filp, poll_table *wait) +{ + struct qrtr_tun *tun = filp->private_data; + __poll_t mask = 0; + + poll_wait(filp, &tun->readq, wait); + + if (!skb_queue_empty(&tun->queue)) + mask |= EPOLLIN | EPOLLRDNORM; + + return mask; +} + +static int qrtr_tun_release(struct inode *inode, struct file *filp) +{ + struct qrtr_tun *tun = filp->private_data; + struct sk_buff *skb; + + qrtr_endpoint_unregister(&tun->ep); + + /* Discard all SKBs */ + while (!skb_queue_empty(&tun->queue)) { + skb = skb_dequeue(&tun->queue); + kfree_skb(skb); + } + + kfree(tun); + + return 0; +} + +static const struct file_operations qrtr_tun_ops = { + .owner = THIS_MODULE, + .open = qrtr_tun_open, + .poll = qrtr_tun_poll, + .read_iter = qrtr_tun_read_iter, + .write_iter = qrtr_tun_write_iter, + .release = qrtr_tun_release, +}; + +static struct miscdevice qrtr_tun_miscdev = { + MISC_DYNAMIC_MINOR, + "qrtr-tun", + &qrtr_tun_ops, +}; + +static int __init qrtr_tun_init(void) +{ + int ret; + + ret = misc_register(&qrtr_tun_miscdev); + if (ret) + pr_err("failed to register Qualcomm IPC Router tun device\n"); + + return ret; +} + +static void __exit qrtr_tun_exit(void) +{ + misc_deregister(&qrtr_tun_miscdev); +} + +module_init(qrtr_tun_init); +module_exit(qrtr_tun_exit); + +MODULE_DESCRIPTION("Qualcomm IPC Router TUN device"); +MODULE_LICENSE("GPL v2"); |