| /* |
| * (c) 2017 Stefano Stabellini <stefano@aporeto.com> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| */ |
| |
| #include <linux/inet.h> |
| #include <linux/kthread.h> |
| #include <linux/list.h> |
| #include <linux/radix-tree.h> |
| #include <linux/module.h> |
| #include <linux/semaphore.h> |
| #include <linux/wait.h> |
| #include <net/sock.h> |
| #include <net/inet_common.h> |
| #include <net/inet_connection_sock.h> |
| #include <net/request_sock.h> |
| |
| #include <xen/events.h> |
| #include <xen/grant_table.h> |
| #include <xen/xen.h> |
| #include <xen/xenbus.h> |
| #include <xen/interface/io/pvcalls.h> |
| |
| #define PVCALLS_VERSIONS "1" |
| #define MAX_RING_ORDER XENBUS_MAX_RING_GRANT_ORDER |
| |
| struct pvcalls_back_global { |
| struct list_head frontends; |
| struct semaphore frontends_lock; |
| } pvcalls_back_global; |
| |
| /* |
| * Per-frontend data structure. It contains pointers to the command |
| * ring, its event channel, a list of active sockets and a tree of |
| * passive sockets. |
| */ |
| struct pvcalls_fedata { |
| struct list_head list; |
| struct xenbus_device *dev; |
| struct xen_pvcalls_sring *sring; |
| struct xen_pvcalls_back_ring ring; |
| int irq; |
| struct list_head socket_mappings; |
| struct radix_tree_root socketpass_mappings; |
| struct semaphore socket_lock; |
| }; |
| |
| struct pvcalls_ioworker { |
| struct work_struct register_work; |
| struct workqueue_struct *wq; |
| }; |
| |
| struct sock_mapping { |
| struct list_head list; |
| struct pvcalls_fedata *fedata; |
| struct sockpass_mapping *sockpass; |
| struct socket *sock; |
| uint64_t id; |
| grant_ref_t ref; |
| struct pvcalls_data_intf *ring; |
| void *bytes; |
| struct pvcalls_data data; |
| uint32_t ring_order; |
| int irq; |
| atomic_t read; |
| atomic_t write; |
| atomic_t io; |
| atomic_t release; |
| void (*saved_data_ready)(struct sock *sk); |
| struct pvcalls_ioworker ioworker; |
| }; |
| |
| struct sockpass_mapping { |
| struct list_head list; |
| struct pvcalls_fedata *fedata; |
| struct socket *sock; |
| uint64_t id; |
| struct xen_pvcalls_request reqcopy; |
| spinlock_t copy_lock; |
| struct workqueue_struct *wq; |
| struct work_struct register_work; |
| void (*saved_data_ready)(struct sock *sk); |
| }; |
| |
| static irqreturn_t pvcalls_back_conn_event(int irq, void *sock_map); |
| static int pvcalls_back_release_active(struct xenbus_device *dev, |
| struct pvcalls_fedata *fedata, |
| struct sock_mapping *map); |
| |
| static void pvcalls_conn_back_read(void *opaque) |
| { |
| struct sock_mapping *map = (struct sock_mapping *)opaque; |
| struct msghdr msg; |
| struct kvec vec[2]; |
| RING_IDX cons, prod, size, wanted, array_size, masked_prod, masked_cons; |
| int32_t error; |
| struct pvcalls_data_intf *intf = map->ring; |
| struct pvcalls_data *data = &map->data; |
| unsigned long flags; |
| int ret; |
| |
| array_size = XEN_FLEX_RING_SIZE(map->ring_order); |
| cons = intf->in_cons; |
| prod = intf->in_prod; |
| error = intf->in_error; |
| /* read the indexes first, then deal with the data */ |
| virt_mb(); |
| |
| if (error) |
| return; |
| |
| size = pvcalls_queued(prod, cons, array_size); |
| if (size >= array_size) |
| return; |
| spin_lock_irqsave(&map->sock->sk->sk_receive_queue.lock, flags); |
| if (skb_queue_empty(&map->sock->sk->sk_receive_queue)) { |
| atomic_set(&map->read, 0); |
| spin_unlock_irqrestore(&map->sock->sk->sk_receive_queue.lock, |
| flags); |
| return; |
| } |
| spin_unlock_irqrestore(&map->sock->sk->sk_receive_queue.lock, flags); |
| wanted = array_size - size; |
| masked_prod = pvcalls_mask(prod, array_size); |
| masked_cons = pvcalls_mask(cons, array_size); |
| |
| memset(&msg, 0, sizeof(msg)); |
| if (masked_prod < masked_cons) { |
| vec[0].iov_base = data->in + masked_prod; |
| vec[0].iov_len = wanted; |
| iov_iter_kvec(&msg.msg_iter, ITER_KVEC|WRITE, vec, 1, wanted); |
| } else { |
| vec[0].iov_base = data->in + masked_prod; |
| vec[0].iov_len = array_size - masked_prod; |
| vec[1].iov_base = data->in; |
| vec[1].iov_len = wanted - vec[0].iov_len; |
| iov_iter_kvec(&msg.msg_iter, ITER_KVEC|WRITE, vec, 2, wanted); |
| } |
| |
| atomic_set(&map->read, 0); |
| ret = inet_recvmsg(map->sock, &msg, wanted, MSG_DONTWAIT); |
| WARN_ON(ret > wanted); |
| if (ret == -EAGAIN) /* shouldn't happen */ |
| return; |
| if (!ret) |
| ret = -ENOTCONN; |
| spin_lock_irqsave(&map->sock->sk->sk_receive_queue.lock, flags); |
| if (ret > 0 && !skb_queue_empty(&map->sock->sk->sk_receive_queue)) |
| atomic_inc(&map->read); |
| spin_unlock_irqrestore(&map->sock->sk->sk_receive_queue.lock, flags); |
| |
| /* write the data, then modify the indexes */ |
| virt_wmb(); |
| if (ret < 0) |
| intf->in_error = ret; |
| else |
| intf->in_prod = prod + ret; |
| /* update the indexes, then notify the other end */ |
| virt_wmb(); |
| notify_remote_via_irq(map->irq); |
| |
| return; |
| } |
| |
| static void pvcalls_conn_back_write(struct sock_mapping *map) |
| { |
| struct pvcalls_data_intf *intf = map->ring; |
| struct pvcalls_data *data = &map->data; |
| struct msghdr msg; |
| struct kvec vec[2]; |
| RING_IDX cons, prod, size, array_size; |
| int ret; |
| |
| cons = intf->out_cons; |
| prod = intf->out_prod; |
| /* read the indexes before dealing with the data */ |
| virt_mb(); |
| |
| array_size = XEN_FLEX_RING_SIZE(map->ring_order); |
| size = pvcalls_queued(prod, cons, array_size); |
| if (size == 0) |
| return; |
| |
| memset(&msg, 0, sizeof(msg)); |
| msg.msg_flags |= MSG_DONTWAIT; |
| if (pvcalls_mask(prod, array_size) > pvcalls_mask(cons, array_size)) { |
| vec[0].iov_base = data->out + pvcalls_mask(cons, array_size); |
| vec[0].iov_len = size; |
| iov_iter_kvec(&msg.msg_iter, ITER_KVEC|READ, vec, 1, size); |
| } else { |
| vec[0].iov_base = data->out + pvcalls_mask(cons, array_size); |
| vec[0].iov_len = array_size - pvcalls_mask(cons, array_size); |
| vec[1].iov_base = data->out; |
| vec[1].iov_len = size - vec[0].iov_len; |
| iov_iter_kvec(&msg.msg_iter, ITER_KVEC|READ, vec, 2, size); |
| } |
| |
| atomic_set(&map->write, 0); |
| ret = inet_sendmsg(map->sock, &msg, size); |
| if (ret == -EAGAIN || (ret >= 0 && ret < size)) { |
| atomic_inc(&map->write); |
| atomic_inc(&map->io); |
| } |
| if (ret == -EAGAIN) |
| return; |
| |
| /* write the data, then update the indexes */ |
| virt_wmb(); |
| if (ret < 0) { |
| intf->out_error = ret; |
| } else { |
| intf->out_error = 0; |
| intf->out_cons = cons + ret; |
| prod = intf->out_prod; |
| } |
| /* update the indexes, then notify the other end */ |
| virt_wmb(); |
| if (prod != cons + ret) |
| atomic_inc(&map->write); |
| notify_remote_via_irq(map->irq); |
| } |
| |
| static void pvcalls_back_ioworker(struct work_struct *work) |
| { |
| struct pvcalls_ioworker *ioworker = container_of(work, |
| struct pvcalls_ioworker, register_work); |
| struct sock_mapping *map = container_of(ioworker, struct sock_mapping, |
| ioworker); |
| |
| while (atomic_read(&map->io) > 0) { |
| if (atomic_read(&map->release) > 0) { |
| atomic_set(&map->release, 0); |
| return; |
| } |
| |
| if (atomic_read(&map->read) > 0) |
| pvcalls_conn_back_read(map); |
| if (atomic_read(&map->write) > 0) |
| pvcalls_conn_back_write(map); |
| |
| atomic_dec(&map->io); |
| } |
| } |
| |
| static int pvcalls_back_socket(struct xenbus_device *dev, |
| struct xen_pvcalls_request *req) |
| { |
| struct pvcalls_fedata *fedata; |
| int ret; |
| struct xen_pvcalls_response *rsp; |
| |
| fedata = dev_get_drvdata(&dev->dev); |
| |
| if (req->u.socket.domain != AF_INET || |
| req->u.socket.type != SOCK_STREAM || |
| (req->u.socket.protocol != IPPROTO_IP && |
| req->u.socket.protocol != AF_INET)) |
| ret = -EAFNOSUPPORT; |
| else |
| ret = 0; |
| |
| /* leave the actual socket allocation for later */ |
| |
| rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++); |
| rsp->req_id = req->req_id; |
| rsp->cmd = req->cmd; |
| rsp->u.socket.id = req->u.socket.id; |
| rsp->ret = ret; |
| |
| return 0; |
| } |
| |
| static void pvcalls_sk_state_change(struct sock *sock) |
| { |
| struct sock_mapping *map = sock->sk_user_data; |
| struct pvcalls_data_intf *intf; |
| |
| if (map == NULL) |
| return; |
| |
| intf = map->ring; |
| intf->in_error = -ENOTCONN; |
| notify_remote_via_irq(map->irq); |
| } |
| |
| static void pvcalls_sk_data_ready(struct sock *sock) |
| { |
| struct sock_mapping *map = sock->sk_user_data; |
| struct pvcalls_ioworker *iow; |
| |
| if (map == NULL) |
| return; |
| |
| iow = &map->ioworker; |
| atomic_inc(&map->read); |
| atomic_inc(&map->io); |
| queue_work(iow->wq, &iow->register_work); |
| } |
| |
| static struct sock_mapping *pvcalls_new_active_socket( |
| struct pvcalls_fedata *fedata, |
| uint64_t id, |
| grant_ref_t ref, |
| uint32_t evtchn, |
| struct socket *sock) |
| { |
| int ret; |
| struct sock_mapping *map; |
| void *page; |
| |
| map = kzalloc(sizeof(*map), GFP_KERNEL); |
| if (map == NULL) |
| return NULL; |
| |
| map->fedata = fedata; |
| map->sock = sock; |
| map->id = id; |
| map->ref = ref; |
| |
| ret = xenbus_map_ring_valloc(fedata->dev, &ref, 1, &page); |
| if (ret < 0) |
| goto out; |
| map->ring = page; |
| map->ring_order = map->ring->ring_order; |
| /* first read the order, then map the data ring */ |
| virt_rmb(); |
| if (map->ring_order > MAX_RING_ORDER) { |
| pr_warn("%s frontend requested ring_order %u, which is > MAX (%u)\n", |
| __func__, map->ring_order, MAX_RING_ORDER); |
| goto out; |
| } |
| ret = xenbus_map_ring_valloc(fedata->dev, map->ring->ref, |
| (1 << map->ring_order), &page); |
| if (ret < 0) |
| goto out; |
| map->bytes = page; |
| |
| ret = bind_interdomain_evtchn_to_irqhandler(fedata->dev->otherend_id, |
| evtchn, |
| pvcalls_back_conn_event, |
| 0, |
| "pvcalls-backend", |
| map); |
| if (ret < 0) |
| goto out; |
| map->irq = ret; |
| |
| map->data.in = map->bytes; |
| map->data.out = map->bytes + XEN_FLEX_RING_SIZE(map->ring_order); |
| |
| map->ioworker.wq = alloc_workqueue("pvcalls_io", WQ_UNBOUND, 1); |
| if (!map->ioworker.wq) |
| goto out; |
| atomic_set(&map->io, 1); |
| INIT_WORK(&map->ioworker.register_work, pvcalls_back_ioworker); |
| |
| down(&fedata->socket_lock); |
| list_add_tail(&map->list, &fedata->socket_mappings); |
| up(&fedata->socket_lock); |
| |
| write_lock_bh(&map->sock->sk->sk_callback_lock); |
| map->saved_data_ready = map->sock->sk->sk_data_ready; |
| map->sock->sk->sk_user_data = map; |
| map->sock->sk->sk_data_ready = pvcalls_sk_data_ready; |
| map->sock->sk->sk_state_change = pvcalls_sk_state_change; |
| write_unlock_bh(&map->sock->sk->sk_callback_lock); |
| |
| return map; |
| out: |
| down(&fedata->socket_lock); |
| list_del(&map->list); |
| pvcalls_back_release_active(fedata->dev, fedata, map); |
| up(&fedata->socket_lock); |
| return NULL; |
| } |
| |
| static int pvcalls_back_connect(struct xenbus_device *dev, |
| struct xen_pvcalls_request *req) |
| { |
| struct pvcalls_fedata *fedata; |
| int ret = -EINVAL; |
| struct socket *sock; |
| struct sock_mapping *map; |
| struct xen_pvcalls_response *rsp; |
| struct sockaddr *sa = (struct sockaddr *)&req->u.connect.addr; |
| |
| fedata = dev_get_drvdata(&dev->dev); |
| |
| if (req->u.connect.len < sizeof(sa->sa_family) || |
| req->u.connect.len > sizeof(req->u.connect.addr) || |
| sa->sa_family != AF_INET) |
| goto out; |
| |
| ret = sock_create(AF_INET, SOCK_STREAM, 0, &sock); |
| if (ret < 0) |
| goto out; |
| ret = inet_stream_connect(sock, sa, req->u.connect.len, 0); |
| if (ret < 0) { |
| sock_release(sock); |
| goto out; |
| } |
| |
| map = pvcalls_new_active_socket(fedata, |
| req->u.connect.id, |
| req->u.connect.ref, |
| req->u.connect.evtchn, |
| sock); |
| if (!map) { |
| ret = -EFAULT; |
| sock_release(map->sock); |
| } |
| |
| out: |
| rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++); |
| rsp->req_id = req->req_id; |
| rsp->cmd = req->cmd; |
| rsp->u.connect.id = req->u.connect.id; |
| rsp->ret = ret; |
| |
| return 0; |
| } |
| |
| static int pvcalls_back_release_active(struct xenbus_device *dev, |
| struct pvcalls_fedata *fedata, |
| struct sock_mapping *map) |
| { |
| disable_irq(map->irq); |
| if (map->sock->sk != NULL) { |
| write_lock_bh(&map->sock->sk->sk_callback_lock); |
| map->sock->sk->sk_user_data = NULL; |
| map->sock->sk->sk_data_ready = map->saved_data_ready; |
| write_unlock_bh(&map->sock->sk->sk_callback_lock); |
| } |
| |
| atomic_set(&map->release, 1); |
| flush_work(&map->ioworker.register_work); |
| |
| xenbus_unmap_ring_vfree(dev, map->bytes); |
| xenbus_unmap_ring_vfree(dev, (void *)map->ring); |
| unbind_from_irqhandler(map->irq, map); |
| |
| sock_release(map->sock); |
| kfree(map); |
| |
| return 0; |
| } |
| |
| static int pvcalls_back_release_passive(struct xenbus_device *dev, |
| struct pvcalls_fedata *fedata, |
| struct sockpass_mapping *mappass) |
| { |
| if (mappass->sock->sk != NULL) { |
| write_lock_bh(&mappass->sock->sk->sk_callback_lock); |
| mappass->sock->sk->sk_user_data = NULL; |
| mappass->sock->sk->sk_data_ready = mappass->saved_data_ready; |
| write_unlock_bh(&mappass->sock->sk->sk_callback_lock); |
| } |
| sock_release(mappass->sock); |
| flush_workqueue(mappass->wq); |
| destroy_workqueue(mappass->wq); |
| kfree(mappass); |
| |
| return 0; |
| } |
| |
| static int pvcalls_back_release(struct xenbus_device *dev, |
| struct xen_pvcalls_request *req) |
| { |
| struct pvcalls_fedata *fedata; |
| struct sock_mapping *map, *n; |
| struct sockpass_mapping *mappass; |
| int ret = 0; |
| struct xen_pvcalls_response *rsp; |
| |
| fedata = dev_get_drvdata(&dev->dev); |
| |
| down(&fedata->socket_lock); |
| list_for_each_entry_safe(map, n, &fedata->socket_mappings, list) { |
| if (map->id == req->u.release.id) { |
| list_del(&map->list); |
| up(&fedata->socket_lock); |
| ret = pvcalls_back_release_active(dev, fedata, map); |
| goto out; |
| } |
| } |
| mappass = radix_tree_lookup(&fedata->socketpass_mappings, |
| req->u.release.id); |
| if (mappass != NULL) { |
| radix_tree_delete(&fedata->socketpass_mappings, mappass->id); |
| up(&fedata->socket_lock); |
| ret = pvcalls_back_release_passive(dev, fedata, mappass); |
| } else |
| up(&fedata->socket_lock); |
| |
| out: |
| rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++); |
| rsp->req_id = req->req_id; |
| rsp->u.release.id = req->u.release.id; |
| rsp->cmd = req->cmd; |
| rsp->ret = ret; |
| return 0; |
| } |
| |
| static void __pvcalls_back_accept(struct work_struct *work) |
| { |
| struct sockpass_mapping *mappass = container_of( |
| work, struct sockpass_mapping, register_work); |
| struct sock_mapping *map; |
| struct pvcalls_ioworker *iow; |
| struct pvcalls_fedata *fedata; |
| struct socket *sock; |
| struct xen_pvcalls_response *rsp; |
| struct xen_pvcalls_request *req; |
| int notify; |
| int ret = -EINVAL; |
| unsigned long flags; |
| |
| fedata = mappass->fedata; |
| /* |
| * __pvcalls_back_accept can race against pvcalls_back_accept. |
| * We only need to check the value of "cmd" on read. It could be |
| * done atomically, but to simplify the code on the write side, we |
| * use a spinlock. |
| */ |
| spin_lock_irqsave(&mappass->copy_lock, flags); |
| req = &mappass->reqcopy; |
| if (req->cmd != PVCALLS_ACCEPT) { |
| spin_unlock_irqrestore(&mappass->copy_lock, flags); |
| return; |
| } |
| spin_unlock_irqrestore(&mappass->copy_lock, flags); |
| |
| sock = sock_alloc(); |
| if (sock == NULL) |
| goto out_error; |
| sock->type = mappass->sock->type; |
| sock->ops = mappass->sock->ops; |
| |
| ret = inet_accept(mappass->sock, sock, O_NONBLOCK, true); |
| if (ret == -EAGAIN) { |
| sock_release(sock); |
| return; |
| } |
| |
| map = pvcalls_new_active_socket(fedata, |
| req->u.accept.id_new, |
| req->u.accept.ref, |
| req->u.accept.evtchn, |
| sock); |
| if (!map) { |
| ret = -EFAULT; |
| sock_release(sock); |
| goto out_error; |
| } |
| |
| map->sockpass = mappass; |
| iow = &map->ioworker; |
| atomic_inc(&map->read); |
| atomic_inc(&map->io); |
| queue_work(iow->wq, &iow->register_work); |
| |
| out_error: |
| rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++); |
| rsp->req_id = req->req_id; |
| rsp->cmd = req->cmd; |
| rsp->u.accept.id = req->u.accept.id; |
| rsp->ret = ret; |
| RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&fedata->ring, notify); |
| if (notify) |
| notify_remote_via_irq(fedata->irq); |
| |
| mappass->reqcopy.cmd = 0; |
| } |
| |
| static void pvcalls_pass_sk_data_ready(struct sock *sock) |
| { |
| struct sockpass_mapping *mappass = sock->sk_user_data; |
| struct pvcalls_fedata *fedata; |
| struct xen_pvcalls_response *rsp; |
| unsigned long flags; |
| int notify; |
| |
| if (mappass == NULL) |
| return; |
| |
| fedata = mappass->fedata; |
| spin_lock_irqsave(&mappass->copy_lock, flags); |
| if (mappass->reqcopy.cmd == PVCALLS_POLL) { |
| rsp = RING_GET_RESPONSE(&fedata->ring, |
| fedata->ring.rsp_prod_pvt++); |
| rsp->req_id = mappass->reqcopy.req_id; |
| rsp->u.poll.id = mappass->reqcopy.u.poll.id; |
| rsp->cmd = mappass->reqcopy.cmd; |
| rsp->ret = 0; |
| |
| mappass->reqcopy.cmd = 0; |
| spin_unlock_irqrestore(&mappass->copy_lock, flags); |
| |
| RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&fedata->ring, notify); |
| if (notify) |
| notify_remote_via_irq(mappass->fedata->irq); |
| } else { |
| spin_unlock_irqrestore(&mappass->copy_lock, flags); |
| queue_work(mappass->wq, &mappass->register_work); |
| } |
| } |
| |
| static int pvcalls_back_bind(struct xenbus_device *dev, |
| struct xen_pvcalls_request *req) |
| { |
| struct pvcalls_fedata *fedata; |
| int ret; |
| struct sockpass_mapping *map; |
| struct xen_pvcalls_response *rsp; |
| |
| fedata = dev_get_drvdata(&dev->dev); |
| |
| map = kzalloc(sizeof(*map), GFP_KERNEL); |
| if (map == NULL) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| INIT_WORK(&map->register_work, __pvcalls_back_accept); |
| spin_lock_init(&map->copy_lock); |
| map->wq = alloc_workqueue("pvcalls_wq", WQ_UNBOUND, 1); |
| if (!map->wq) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| ret = sock_create(AF_INET, SOCK_STREAM, 0, &map->sock); |
| if (ret < 0) |
| goto out; |
| |
| ret = inet_bind(map->sock, (struct sockaddr *)&req->u.bind.addr, |
| req->u.bind.len); |
| if (ret < 0) |
| goto out; |
| |
| map->fedata = fedata; |
| map->id = req->u.bind.id; |
| |
| down(&fedata->socket_lock); |
| ret = radix_tree_insert(&fedata->socketpass_mappings, map->id, |
| map); |
| up(&fedata->socket_lock); |
| if (ret) |
| goto out; |
| |
| write_lock_bh(&map->sock->sk->sk_callback_lock); |
| map->saved_data_ready = map->sock->sk->sk_data_ready; |
| map->sock->sk->sk_user_data = map; |
| map->sock->sk->sk_data_ready = pvcalls_pass_sk_data_ready; |
| write_unlock_bh(&map->sock->sk->sk_callback_lock); |
| |
| out: |
| if (ret) { |
| if (map && map->sock) |
| sock_release(map->sock); |
| if (map && map->wq) |
| destroy_workqueue(map->wq); |
| kfree(map); |
| } |
| rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++); |
| rsp->req_id = req->req_id; |
| rsp->cmd = req->cmd; |
| rsp->u.bind.id = req->u.bind.id; |
| rsp->ret = ret; |
| return 0; |
| } |
| |
| static int pvcalls_back_listen(struct xenbus_device *dev, |
| struct xen_pvcalls_request *req) |
| { |
| struct pvcalls_fedata *fedata; |
| int ret = -EINVAL; |
| struct sockpass_mapping *map; |
| struct xen_pvcalls_response *rsp; |
| |
| fedata = dev_get_drvdata(&dev->dev); |
| |
| down(&fedata->socket_lock); |
| map = radix_tree_lookup(&fedata->socketpass_mappings, req->u.listen.id); |
| up(&fedata->socket_lock); |
| if (map == NULL) |
| goto out; |
| |
| ret = inet_listen(map->sock, req->u.listen.backlog); |
| |
| out: |
| rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++); |
| rsp->req_id = req->req_id; |
| rsp->cmd = req->cmd; |
| rsp->u.listen.id = req->u.listen.id; |
| rsp->ret = ret; |
| return 0; |
| } |
| |
| static int pvcalls_back_accept(struct xenbus_device *dev, |
| struct xen_pvcalls_request *req) |
| { |
| struct pvcalls_fedata *fedata; |
| struct sockpass_mapping *mappass; |
| int ret = -EINVAL; |
| struct xen_pvcalls_response *rsp; |
| unsigned long flags; |
| |
| fedata = dev_get_drvdata(&dev->dev); |
| |
| down(&fedata->socket_lock); |
| mappass = radix_tree_lookup(&fedata->socketpass_mappings, |
| req->u.accept.id); |
| up(&fedata->socket_lock); |
| if (mappass == NULL) |
| goto out_error; |
| |
| /* |
| * Limitation of the current implementation: only support one |
| * concurrent accept or poll call on one socket. |
| */ |
| spin_lock_irqsave(&mappass->copy_lock, flags); |
| if (mappass->reqcopy.cmd != 0) { |
| spin_unlock_irqrestore(&mappass->copy_lock, flags); |
| ret = -EINTR; |
| goto out_error; |
| } |
| |
| mappass->reqcopy = *req; |
| spin_unlock_irqrestore(&mappass->copy_lock, flags); |
| queue_work(mappass->wq, &mappass->register_work); |
| |
| /* Tell the caller we don't need to send back a notification yet */ |
| return -1; |
| |
| out_error: |
| rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++); |
| rsp->req_id = req->req_id; |
| rsp->cmd = req->cmd; |
| rsp->u.accept.id = req->u.accept.id; |
| rsp->ret = ret; |
| return 0; |
| } |
| |
| static int pvcalls_back_poll(struct xenbus_device *dev, |
| struct xen_pvcalls_request *req) |
| { |
| struct pvcalls_fedata *fedata; |
| struct sockpass_mapping *mappass; |
| struct xen_pvcalls_response *rsp; |
| struct inet_connection_sock *icsk; |
| struct request_sock_queue *queue; |
| unsigned long flags; |
| int ret; |
| bool data; |
| |
| fedata = dev_get_drvdata(&dev->dev); |
| |
| down(&fedata->socket_lock); |
| mappass = radix_tree_lookup(&fedata->socketpass_mappings, |
| req->u.poll.id); |
| up(&fedata->socket_lock); |
| if (mappass == NULL) |
| return -EINVAL; |
| |
| /* |
| * Limitation of the current implementation: only support one |
| * concurrent accept or poll call on one socket. |
| */ |
| spin_lock_irqsave(&mappass->copy_lock, flags); |
| if (mappass->reqcopy.cmd != 0) { |
| ret = -EINTR; |
| goto out; |
| } |
| |
| mappass->reqcopy = *req; |
| icsk = inet_csk(mappass->sock->sk); |
| queue = &icsk->icsk_accept_queue; |
| data = queue->rskq_accept_head != NULL; |
| if (data) { |
| mappass->reqcopy.cmd = 0; |
| ret = 0; |
| goto out; |
| } |
| spin_unlock_irqrestore(&mappass->copy_lock, flags); |
| |
| /* Tell the caller we don't need to send back a notification yet */ |
| return -1; |
| |
| out: |
| spin_unlock_irqrestore(&mappass->copy_lock, flags); |
| |
| rsp = RING_GET_RESPONSE(&fedata->ring, fedata->ring.rsp_prod_pvt++); |
| rsp->req_id = req->req_id; |
| rsp->cmd = req->cmd; |
| rsp->u.poll.id = req->u.poll.id; |
| rsp->ret = ret; |
| return 0; |
| } |
| |
| static int pvcalls_back_handle_cmd(struct xenbus_device *dev, |
| struct xen_pvcalls_request *req) |
| { |
| int ret = 0; |
| |
| switch (req->cmd) { |
| case PVCALLS_SOCKET: |
| ret = pvcalls_back_socket(dev, req); |
| break; |
| case PVCALLS_CONNECT: |
| ret = pvcalls_back_connect(dev, req); |
| break; |
| case PVCALLS_RELEASE: |
| ret = pvcalls_back_release(dev, req); |
| break; |
| case PVCALLS_BIND: |
| ret = pvcalls_back_bind(dev, req); |
| break; |
| case PVCALLS_LISTEN: |
| ret = pvcalls_back_listen(dev, req); |
| break; |
| case PVCALLS_ACCEPT: |
| ret = pvcalls_back_accept(dev, req); |
| break; |
| case PVCALLS_POLL: |
| ret = pvcalls_back_poll(dev, req); |
| break; |
| default: |
| { |
| struct pvcalls_fedata *fedata; |
| struct xen_pvcalls_response *rsp; |
| |
| fedata = dev_get_drvdata(&dev->dev); |
| rsp = RING_GET_RESPONSE( |
| &fedata->ring, fedata->ring.rsp_prod_pvt++); |
| rsp->req_id = req->req_id; |
| rsp->cmd = req->cmd; |
| rsp->ret = -ENOTSUPP; |
| break; |
| } |
| } |
| return ret; |
| } |
| |
| static void pvcalls_back_work(struct pvcalls_fedata *fedata) |
| { |
| int notify, notify_all = 0, more = 1; |
| struct xen_pvcalls_request req; |
| struct xenbus_device *dev = fedata->dev; |
| |
| while (more) { |
| while (RING_HAS_UNCONSUMED_REQUESTS(&fedata->ring)) { |
| RING_COPY_REQUEST(&fedata->ring, |
| fedata->ring.req_cons++, |
| &req); |
| |
| if (!pvcalls_back_handle_cmd(dev, &req)) { |
| RING_PUSH_RESPONSES_AND_CHECK_NOTIFY( |
| &fedata->ring, notify); |
| notify_all += notify; |
| } |
| } |
| |
| if (notify_all) { |
| notify_remote_via_irq(fedata->irq); |
| notify_all = 0; |
| } |
| |
| RING_FINAL_CHECK_FOR_REQUESTS(&fedata->ring, more); |
| } |
| } |
| |
| static irqreturn_t pvcalls_back_event(int irq, void *dev_id) |
| { |
| struct xenbus_device *dev = dev_id; |
| struct pvcalls_fedata *fedata = NULL; |
| |
| if (dev == NULL) |
| return IRQ_HANDLED; |
| |
| fedata = dev_get_drvdata(&dev->dev); |
| if (fedata == NULL) |
| return IRQ_HANDLED; |
| |
| pvcalls_back_work(fedata); |
| return IRQ_HANDLED; |
| } |
| |
| static irqreturn_t pvcalls_back_conn_event(int irq, void *sock_map) |
| { |
| struct sock_mapping *map = sock_map; |
| struct pvcalls_ioworker *iow; |
| |
| if (map == NULL || map->sock == NULL || map->sock->sk == NULL || |
| map->sock->sk->sk_user_data != map) |
| return IRQ_HANDLED; |
| |
| iow = &map->ioworker; |
| |
| atomic_inc(&map->write); |
| atomic_inc(&map->io); |
| queue_work(iow->wq, &iow->register_work); |
| |
| return IRQ_HANDLED; |
| } |
| |
| static int backend_connect(struct xenbus_device *dev) |
| { |
| int err, evtchn; |
| grant_ref_t ring_ref; |
| struct pvcalls_fedata *fedata = NULL; |
| |
| fedata = kzalloc(sizeof(struct pvcalls_fedata), GFP_KERNEL); |
| if (!fedata) |
| return -ENOMEM; |
| |
| fedata->irq = -1; |
| err = xenbus_scanf(XBT_NIL, dev->otherend, "port", "%u", |
| &evtchn); |
| if (err != 1) { |
| err = -EINVAL; |
| xenbus_dev_fatal(dev, err, "reading %s/event-channel", |
| dev->otherend); |
| goto error; |
| } |
| |
| err = xenbus_scanf(XBT_NIL, dev->otherend, "ring-ref", "%u", &ring_ref); |
| if (err != 1) { |
| err = -EINVAL; |
| xenbus_dev_fatal(dev, err, "reading %s/ring-ref", |
| dev->otherend); |
| goto error; |
| } |
| |
| err = bind_interdomain_evtchn_to_irq(dev->otherend_id, evtchn); |
| if (err < 0) |
| goto error; |
| fedata->irq = err; |
| |
| err = request_threaded_irq(fedata->irq, NULL, pvcalls_back_event, |
| IRQF_ONESHOT, "pvcalls-back", dev); |
| if (err < 0) |
| goto error; |
| |
| err = xenbus_map_ring_valloc(dev, &ring_ref, 1, |
| (void **)&fedata->sring); |
| if (err < 0) |
| goto error; |
| |
| BACK_RING_INIT(&fedata->ring, fedata->sring, XEN_PAGE_SIZE * 1); |
| fedata->dev = dev; |
| |
| INIT_LIST_HEAD(&fedata->socket_mappings); |
| INIT_RADIX_TREE(&fedata->socketpass_mappings, GFP_KERNEL); |
| sema_init(&fedata->socket_lock, 1); |
| dev_set_drvdata(&dev->dev, fedata); |
| |
| down(&pvcalls_back_global.frontends_lock); |
| list_add_tail(&fedata->list, &pvcalls_back_global.frontends); |
| up(&pvcalls_back_global.frontends_lock); |
| |
| return 0; |
| |
| error: |
| if (fedata->irq >= 0) |
| unbind_from_irqhandler(fedata->irq, dev); |
| if (fedata->sring != NULL) |
| xenbus_unmap_ring_vfree(dev, fedata->sring); |
| kfree(fedata); |
| return err; |
| } |
| |
| static int backend_disconnect(struct xenbus_device *dev) |
| { |
| struct pvcalls_fedata *fedata; |
| struct sock_mapping *map, *n; |
| struct sockpass_mapping *mappass; |
| struct radix_tree_iter iter; |
| void **slot; |
| |
| |
| fedata = dev_get_drvdata(&dev->dev); |
| |
| down(&fedata->socket_lock); |
| list_for_each_entry_safe(map, n, &fedata->socket_mappings, list) { |
| list_del(&map->list); |
| pvcalls_back_release_active(dev, fedata, map); |
| } |
| |
| radix_tree_for_each_slot(slot, &fedata->socketpass_mappings, &iter, 0) { |
| mappass = radix_tree_deref_slot(slot); |
| if (!mappass) |
| continue; |
| if (radix_tree_exception(mappass)) { |
| if (radix_tree_deref_retry(mappass)) |
| slot = radix_tree_iter_retry(&iter); |
| } else { |
| radix_tree_delete(&fedata->socketpass_mappings, |
| mappass->id); |
| pvcalls_back_release_passive(dev, fedata, mappass); |
| } |
| } |
| up(&fedata->socket_lock); |
| |
| unbind_from_irqhandler(fedata->irq, dev); |
| xenbus_unmap_ring_vfree(dev, fedata->sring); |
| |
| list_del(&fedata->list); |
| kfree(fedata); |
| dev_set_drvdata(&dev->dev, NULL); |
| |
| return 0; |
| } |
| |
| static int pvcalls_back_probe(struct xenbus_device *dev, |
| const struct xenbus_device_id *id) |
| { |
| int err, abort; |
| struct xenbus_transaction xbt; |
| |
| again: |
| abort = 1; |
| |
| err = xenbus_transaction_start(&xbt); |
| if (err) { |
| pr_warn("%s cannot create xenstore transaction\n", __func__); |
| return err; |
| } |
| |
| err = xenbus_printf(xbt, dev->nodename, "versions", "%s", |
| PVCALLS_VERSIONS); |
| if (err) { |
| pr_warn("%s write out 'versions' failed\n", __func__); |
| goto abort; |
| } |
| |
| err = xenbus_printf(xbt, dev->nodename, "max-page-order", "%u", |
| MAX_RING_ORDER); |
| if (err) { |
| pr_warn("%s write out 'max-page-order' failed\n", __func__); |
| goto abort; |
| } |
| |
| err = xenbus_printf(xbt, dev->nodename, "function-calls", |
| XENBUS_FUNCTIONS_CALLS); |
| if (err) { |
| pr_warn("%s write out 'function-calls' failed\n", __func__); |
| goto abort; |
| } |
| |
| abort = 0; |
| abort: |
| err = xenbus_transaction_end(xbt, abort); |
| if (err) { |
| if (err == -EAGAIN && !abort) |
| goto again; |
| pr_warn("%s cannot complete xenstore transaction\n", __func__); |
| return err; |
| } |
| |
| if (abort) |
| return -EFAULT; |
| |
| xenbus_switch_state(dev, XenbusStateInitWait); |
| |
| return 0; |
| } |
| |
| static void set_backend_state(struct xenbus_device *dev, |
| enum xenbus_state state) |
| { |
| while (dev->state != state) { |
| switch (dev->state) { |
| case XenbusStateClosed: |
| switch (state) { |
| case XenbusStateInitWait: |
| case XenbusStateConnected: |
| xenbus_switch_state(dev, XenbusStateInitWait); |
| break; |
| case XenbusStateClosing: |
| xenbus_switch_state(dev, XenbusStateClosing); |
| break; |
| default: |
| WARN_ON(1); |
| } |
| break; |
| case XenbusStateInitWait: |
| case XenbusStateInitialised: |
| switch (state) { |
| case XenbusStateConnected: |
| backend_connect(dev); |
| xenbus_switch_state(dev, XenbusStateConnected); |
| break; |
| case XenbusStateClosing: |
| case XenbusStateClosed: |
| xenbus_switch_state(dev, XenbusStateClosing); |
| break; |
| default: |
| WARN_ON(1); |
| } |
| break; |
| case XenbusStateConnected: |
| switch (state) { |
| case XenbusStateInitWait: |
| case XenbusStateClosing: |
| case XenbusStateClosed: |
| down(&pvcalls_back_global.frontends_lock); |
| backend_disconnect(dev); |
| up(&pvcalls_back_global.frontends_lock); |
| xenbus_switch_state(dev, XenbusStateClosing); |
| break; |
| default: |
| WARN_ON(1); |
| } |
| break; |
| case XenbusStateClosing: |
| switch (state) { |
| case XenbusStateInitWait: |
| case XenbusStateConnected: |
| case XenbusStateClosed: |
| xenbus_switch_state(dev, XenbusStateClosed); |
| break; |
| default: |
| WARN_ON(1); |
| } |
| break; |
| default: |
| WARN_ON(1); |
| } |
| } |
| } |
| |
| static void pvcalls_back_changed(struct xenbus_device *dev, |
| enum xenbus_state frontend_state) |
| { |
| switch (frontend_state) { |
| case XenbusStateInitialising: |
| set_backend_state(dev, XenbusStateInitWait); |
| break; |
| |
| case XenbusStateInitialised: |
| case XenbusStateConnected: |
| set_backend_state(dev, XenbusStateConnected); |
| break; |
| |
| case XenbusStateClosing: |
| set_backend_state(dev, XenbusStateClosing); |
| break; |
| |
| case XenbusStateClosed: |
| set_backend_state(dev, XenbusStateClosed); |
| if (xenbus_dev_is_online(dev)) |
| break; |
| device_unregister(&dev->dev); |
| break; |
| case XenbusStateUnknown: |
| set_backend_state(dev, XenbusStateClosed); |
| device_unregister(&dev->dev); |
| break; |
| |
| default: |
| xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend", |
| frontend_state); |
| break; |
| } |
| } |
| |
| static int pvcalls_back_remove(struct xenbus_device *dev) |
| { |
| return 0; |
| } |
| |
| static int pvcalls_back_uevent(struct xenbus_device *xdev, |
| struct kobj_uevent_env *env) |
| { |
| return 0; |
| } |
| |
| static const struct xenbus_device_id pvcalls_back_ids[] = { |
| { "pvcalls" }, |
| { "" } |
| }; |
| |
| static struct xenbus_driver pvcalls_back_driver = { |
| .ids = pvcalls_back_ids, |
| .probe = pvcalls_back_probe, |
| .remove = pvcalls_back_remove, |
| .uevent = pvcalls_back_uevent, |
| .otherend_changed = pvcalls_back_changed, |
| }; |
| |
| static int __init pvcalls_back_init(void) |
| { |
| int ret; |
| |
| if (!xen_domain()) |
| return -ENODEV; |
| |
| ret = xenbus_register_backend(&pvcalls_back_driver); |
| if (ret < 0) |
| return ret; |
| |
| sema_init(&pvcalls_back_global.frontends_lock, 1); |
| INIT_LIST_HEAD(&pvcalls_back_global.frontends); |
| return 0; |
| } |
| module_init(pvcalls_back_init); |
| |
| static void __exit pvcalls_back_fin(void) |
| { |
| struct pvcalls_fedata *fedata, *nfedata; |
| |
| down(&pvcalls_back_global.frontends_lock); |
| list_for_each_entry_safe(fedata, nfedata, |
| &pvcalls_back_global.frontends, list) { |
| backend_disconnect(fedata->dev); |
| } |
| up(&pvcalls_back_global.frontends_lock); |
| |
| xenbus_unregister_driver(&pvcalls_back_driver); |
| } |
| |
| module_exit(pvcalls_back_fin); |
| |
| MODULE_DESCRIPTION("Xen PV Calls backend driver"); |
| MODULE_AUTHOR("Stefano Stabellini <sstabellini@kernel.org>"); |
| MODULE_LICENSE("GPL"); |