Hyper-V Sockets (hv_sock) supplies a byte-stream based communication mechanism between the host and the guest. It's somewhat like TCP over VMBus, but the transportation layer (VMBus) is much simpler than IP.
With Hyper-V Sockets, applications between the host and the guest can talk to each other directly by the traditional BSD-style socket APIs. Hyper-V Sockets is only available on new Windows hosts, like Windows Server 2016. More info is in this article "Make your own integration services": https://msdn.microsoft.com/en-us/virtualization/hyperv_on_windows/develop/make_mgmt_service The patch implements the necessary support in the guest side by introducing a new socket address family AF_HYPERV. Signed-off-by: Dexuan Cui <de...@microsoft.com> Cc: "K. Y. Srinivasan" <k...@microsoft.com> Cc: Haiyang Zhang <haiya...@microsoft.com> Cc: Vitaly Kuznetsov <vkuzn...@redhat.com> Cc: Cathy Avery <cav...@redhat.com> --- You can also get the patch on this branch: https://github.com/dcui/linux/commits/decui/hv_sock/net-next/20160515_v11 For the change log before v10, please see https://lkml.org/lkml/2016/5/4/532 In v10, the main changes consist of 1) minimize struct hvsock_sock by making the send/recv buffers pointers. the buffers are allocated by kmalloc() in __hvsock_create(). 2) minimize the sizes of the send/recv buffers and the vmbus ringbuffers. In v11, the changes are: 1) add module params: send_ring_page, recv_ring_page. They can be used to enlarge the ringbuffer size to get better performance, e.g., # modprobe hv_sock recv_ring_page=16 send_ring_page=16 By default, recv_ring_page is 3 and send_ring_page is 2. 2) add module param max_socket_number (the default is 1024). A user can enlarge the number to create more than 1024 hv_sock sockets. By default, 1024 sockets take about 1024 * (3+2+1+1) * 4KB = 28M bytes. (Here 1+1 means 1 page for send/recv buffers per connection, respectively.) 3) implement the TODO in hvsock_shutdown(). 4) fix a bug in hvsock_close_connection(): I remove "sk->sk_socket->state = SS_UNCONNECTED;" -- actually this line is not really useful. For a connection triggered by a host app’s connect(), sk->sk_socket remains NULL before the connection is accepted by the server app (in Linux VM): see hvsock_accept() -> hvsock_accept_wait() -> sock_graft(connected, newsock). If the host app exits before the server app’s accept() returns, the host can send a rescind-message to close the connection and later in the Linux VM’s message handler i.e. vmbus_onoffer_rescind()), Linux will get a NULL de-referencing crash. 5) fix a bug in hvsock_open_connection() I move the vmbus_set_chn_rescind_callback() to a later place, because when vmbus_open() fails, hvsock_close_connection() can do nothing and we count on vmbus_onoffer_rescind() -> vmbus_device_unregister() to clean up the device. 6) some stylistic modificiation. MAINTAINERS | 2 + include/linux/hyperv.h | 14 + include/linux/socket.h | 4 +- include/net/af_hvsock.h | 78 +++ include/uapi/linux/hyperv.h | 25 + net/Kconfig | 1 + net/Makefile | 1 + net/hv_sock/Kconfig | 10 + net/hv_sock/Makefile | 3 + net/hv_sock/af_hvsock.c | 1520 +++++++++++++++++++++++++++++++++++++++++++ 10 files changed, 1657 insertions(+), 1 deletion(-) diff --git a/MAINTAINERS b/MAINTAINERS index b57df66..c9fe2c6 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -5271,7 +5271,9 @@ F: drivers/pci/host/pci-hyperv.c F: drivers/net/hyperv/ F: drivers/scsi/storvsc_drv.c F: drivers/video/fbdev/hyperv_fb.c +F: net/hv_sock/ F: include/linux/hyperv.h +F: include/net/af_hvsock.h F: tools/hv/ F: Documentation/ABI/stable/sysfs-bus-vmbus diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index aa0fadc..7be7237 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -1338,4 +1338,18 @@ extern __u32 vmbus_proto_version; int vmbus_send_tl_connect_request(const uuid_le *shv_guest_servie_id, const uuid_le *shv_host_servie_id); +struct vmpipe_proto_header { + u32 pkt_type; + u32 data_size; +}; + +#define HVSOCK_HEADER_LEN (sizeof(struct vmpacket_descriptor) + \ + sizeof(struct vmpipe_proto_header)) + +/* See 'prev_indices' in hv_ringbuffer_read(), hv_ringbuffer_write() */ +#define PREV_INDICES_LEN (sizeof(u64)) + +#define HVSOCK_PKT_LEN(payload_len) (HVSOCK_HEADER_LEN + \ + ALIGN((payload_len), 8) + \ + PREV_INDICES_LEN) #endif /* _HYPERV_H */ diff --git a/include/linux/socket.h b/include/linux/socket.h index b5cc5a6..0b68b58 100644 --- a/include/linux/socket.h +++ b/include/linux/socket.h @@ -202,8 +202,9 @@ struct ucred { #define AF_VSOCK 40 /* vSockets */ #define AF_KCM 41 /* Kernel Connection Multiplexor*/ #define AF_QIPCRTR 42 /* Qualcomm IPC Router */ +#define AF_HYPERV 43 /* Hyper-V Sockets */ -#define AF_MAX 43 /* For now.. */ +#define AF_MAX 44 /* For now.. */ /* Protocol families, same as address families. */ #define PF_UNSPEC AF_UNSPEC @@ -251,6 +252,7 @@ struct ucred { #define PF_VSOCK AF_VSOCK #define PF_KCM AF_KCM #define PF_QIPCRTR AF_QIPCRTR +#define PF_HYPERV AF_HYPERV #define PF_MAX AF_MAX /* Maximum queue length specifiable by listen. */ diff --git a/include/net/af_hvsock.h b/include/net/af_hvsock.h new file mode 100644 index 0000000..7c8c41e --- /dev/null +++ b/include/net/af_hvsock.h @@ -0,0 +1,78 @@ +#ifndef __AF_HVSOCK_H__ +#define __AF_HVSOCK_H__ + +#include <linux/kernel.h> +#include <linux/hyperv.h> +#include <net/sock.h> + +/* Note: 3-page is the minimal recv ringbuffer size by default: + * + * the 1st page is used as the shared read/write index etc, rather than data: + * see hv_ringbuffer_init(); + * + * the payload length in the vmbus pipe message received from the host can + * be 4096 bytes, and considing the header of HVSOCK_HEADER_LEN bytes, we + * need at least 2 extra pages for ringbuffer data. + */ +#define HVSOCK_RCV_BUF_SZ PAGE_SIZE +#define DEF_RINGBUFFER_PAGES_HVSOCK_RCV 3 + +/* As to send, here let's make sure the hvsock_send_buf struct can be held in 1 + * page, and since we want to use 2 pages for the send ringbuffer size (this is + * the minimal size by default, because the 1st page of the two is used as the + * shared read/write index etc, rather than data), we only have 1 page for + * ringbuffer data, this means: the max payload length for hvsock data is + * PAGE_SIZE - HVSOCK_PKT_LEN(0). And, let's reduce the length by 8-bytes + * because the ringbuffer can't be 100% full: see hv_ringbuffer_write(). + */ +#define HVSOCK_SND_BUF_SZ (PAGE_SIZE - HVSOCK_PKT_LEN(0) - 8) +#define DEF_RINGBUFFER_PAGES_HVSOCK_SND 2 + +/* We only send data when the available space is "big enough". This artificial + * value must be less than HVSOCK_SND_BUF_SZ. + * + */ +#define HVSOCK_SND_THRESHOLD (PAGE_SIZE / 2) + +#define sk_to_hvsock(__sk) ((struct hvsock_sock *)(__sk)) +#define hvsock_to_sk(__hvsk) ((struct sock *)(__hvsk)) + +struct hvsock_send_buf { + struct vmpipe_proto_header hdr; + u8 buf[HVSOCK_SND_BUF_SZ]; +}; + +struct hvsock_recv_buf { + struct vmpipe_proto_header hdr; + u8 buf[HVSOCK_RCV_BUF_SZ]; + + unsigned int data_len; + unsigned int data_offset; +}; + +struct hvsock_sock { + /* sk must be the first member. */ + struct sock sk; + + struct sockaddr_hv local_addr; + struct sockaddr_hv remote_addr; + + /* protected by the global hvsock_mutex */ + struct list_head bound_list; + struct list_head connected_list; + + struct list_head accept_queue; + /* used by enqueue and dequeue */ + struct mutex accept_queue_mutex; + + struct delayed_work dwork; + + u32 peer_shutdown; + + struct vmbus_channel *channel; + + struct hvsock_send_buf *send; + struct hvsock_recv_buf *recv; +}; + +#endif /* __AF_HVSOCK_H__ */ diff --git a/include/uapi/linux/hyperv.h b/include/uapi/linux/hyperv.h index e347b24..408b832 100644 --- a/include/uapi/linux/hyperv.h +++ b/include/uapi/linux/hyperv.h @@ -26,6 +26,7 @@ #define _UAPI_HYPERV_H #include <linux/uuid.h> +#include <linux/socket.h> /* * Framework version for util services. @@ -396,4 +397,28 @@ struct hv_kvp_ip_msg { struct hv_kvp_ipaddr_value kvp_ip_val; } __attribute__((packed)); +/* + * This is the address fromat of Hyper-V Sockets. + * Note: here we just borrow the kernel's built-in type uuid_le. When + * an application calls bind() or connect(), the 2 members of struct + * sockaddr_hv must be of GUID. + * The GUID format differs from the UUID format only in the byte order of + * the first 3 fields. Refer to: + * https://en.wikipedia.org/wiki/Globally_unique_identifier + */ +#define guid_t uuid_le +struct sockaddr_hv { + __kernel_sa_family_t shv_family; /* Address family */ + __le16 reserved; /* Must be Zero */ + guid_t shv_vm_id; /* VM ID */ + guid_t shv_service_id; /* Service ID */ +}; + +#define SHV_VMID_GUEST NULL_UUID_LE +#define SHV_VMID_HOST NULL_UUID_LE + +#define SHV_SERVICE_ID_ANY NULL_UUID_LE + +#define SHV_PROTO_RAW 1 + #endif /* _UAPI_HYPERV_H */ diff --git a/net/Kconfig b/net/Kconfig index b841c42..366e61f 100644 --- a/net/Kconfig +++ b/net/Kconfig @@ -231,6 +231,7 @@ source "net/dns_resolver/Kconfig" source "net/batman-adv/Kconfig" source "net/openvswitch/Kconfig" source "net/vmw_vsock/Kconfig" +source "net/hv_sock/Kconfig" source "net/netlink/Kconfig" source "net/mpls/Kconfig" source "net/hsr/Kconfig" diff --git a/net/Makefile b/net/Makefile index bdd1455..ec175dd 100644 --- a/net/Makefile +++ b/net/Makefile @@ -70,6 +70,7 @@ obj-$(CONFIG_BATMAN_ADV) += batman-adv/ obj-$(CONFIG_NFC) += nfc/ obj-$(CONFIG_OPENVSWITCH) += openvswitch/ obj-$(CONFIG_VSOCKETS) += vmw_vsock/ +obj-$(CONFIG_HYPERV_SOCK) += hv_sock/ obj-$(CONFIG_MPLS) += mpls/ obj-$(CONFIG_HSR) += hsr/ ifneq ($(CONFIG_NET_SWITCHDEV),) diff --git a/net/hv_sock/Kconfig b/net/hv_sock/Kconfig new file mode 100644 index 0000000..1f41848 --- /dev/null +++ b/net/hv_sock/Kconfig @@ -0,0 +1,10 @@ +config HYPERV_SOCK + tristate "Hyper-V Sockets" + depends on HYPERV + default m if HYPERV + help + Hyper-V Sockets is somewhat like TCP over VMBus, allowing + communication between Linux guest and Hyper-V host without TCP/IP. + + To compile this driver as a module, choose M here: the module + will be called hv_sock. diff --git a/net/hv_sock/Makefile b/net/hv_sock/Makefile new file mode 100644 index 0000000..716c012 --- /dev/null +++ b/net/hv_sock/Makefile @@ -0,0 +1,3 @@ +obj-$(CONFIG_HYPERV_SOCK) += hv_sock.o + +hv_sock-y += af_hvsock.o diff --git a/net/hv_sock/af_hvsock.c b/net/hv_sock/af_hvsock.c new file mode 100644 index 0000000..b91bd60 --- /dev/null +++ b/net/hv_sock/af_hvsock.c @@ -0,0 +1,1520 @@ +/* + * Hyper-V Sockets -- a socket-based communication channel between the + * Hyper-V host and the virtual machines running on it. + * + * Copyright(c) 2016, Microsoft Corporation. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote + * products derived from this software without specific prior written + * permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, + * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING + * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/init.h> +#include <linux/module.h> +#include <net/af_hvsock.h> + +static uint send_ring_page = DEF_RINGBUFFER_PAGES_HVSOCK_SND; +static uint recv_ring_page = DEF_RINGBUFFER_PAGES_HVSOCK_RCV; +static uint max_socket_number = 1024; + +static atomic_t total_num_hvsock = ATOMIC_INIT(0); + +module_param(send_ring_page, uint, 0444); +MODULE_PARM_DESC(send_ring_page, "Send ring buffer size (# of pages)"); + +module_param(recv_ring_page, uint, 0444); +MODULE_PARM_DESC(recv_ring_page, "Receive ring buffer size (# of pages)"); + +module_param(max_socket_number, uint, 0644); +MODULE_PARM_DESC(max_socket_number, "The max number of created sockets"); + +static struct proto hvsock_proto = { + .name = "HV_SOCK", + .owner = THIS_MODULE, + .obj_size = sizeof(struct hvsock_sock), +}; + +#define SS_LISTEN 255 + +static LIST_HEAD(hvsock_bound_list); +static LIST_HEAD(hvsock_connected_list); +static DEFINE_MUTEX(hvsock_mutex); + +static bool uuid_equals(uuid_le u1, uuid_le u2) +{ + return !uuid_le_cmp(u1, u2); +} + +static struct sock *hvsock_find_bound_socket(const struct sockaddr_hv *addr) +{ + struct hvsock_sock *hvsk; + + list_for_each_entry(hvsk, &hvsock_bound_list, bound_list) { + if (uuid_equals(addr->shv_service_id, + hvsk->local_addr.shv_service_id)) + return hvsock_to_sk(hvsk); + } + return NULL; +} + +static struct sock *hvsock_find_connected_socket_by_channel( + const struct vmbus_channel *channel) +{ + struct hvsock_sock *hvsk; + + list_for_each_entry(hvsk, &hvsock_connected_list, connected_list) { + if (hvsk->channel == channel) + return hvsock_to_sk(hvsk); + } + return NULL; +} + +static +void hvsock_enqueue_accept(struct sock *listener, struct sock *connected) +{ + struct hvsock_sock *hvlistener; + struct hvsock_sock *hvconnected; + + hvlistener = sk_to_hvsock(listener); + hvconnected = sk_to_hvsock(connected); + + sock_hold(connected); + sock_hold(listener); + + mutex_lock(&hvlistener->accept_queue_mutex); + list_add_tail(&hvconnected->accept_queue, &hvlistener->accept_queue); + listener->sk_ack_backlog++; + mutex_unlock(&hvlistener->accept_queue_mutex); +} + +static struct sock *hvsock_dequeue_accept(struct sock *listener) +{ + struct hvsock_sock *hvlistener; + struct hvsock_sock *hvconnected; + + hvlistener = sk_to_hvsock(listener); + + mutex_lock(&hvlistener->accept_queue_mutex); + + if (list_empty(&hvlistener->accept_queue)) { + mutex_unlock(&hvlistener->accept_queue_mutex); + return NULL; + } + + hvconnected = list_entry(hvlistener->accept_queue.next, + struct hvsock_sock, accept_queue); + + list_del_init(&hvconnected->accept_queue); + listener->sk_ack_backlog--; + + mutex_unlock(&hvlistener->accept_queue_mutex); + + sock_put(listener); + /* The caller will need a reference on the connected socket so we let + * it call sock_put(). + */ + + return hvsock_to_sk(hvconnected); +} + +static bool hvsock_is_accept_queue_empty(struct sock *sk) +{ + struct hvsock_sock *hvsk = sk_to_hvsock(sk); + int ret; + + mutex_lock(&hvsk->accept_queue_mutex); + ret = list_empty(&hvsk->accept_queue); + mutex_unlock(&hvsk->accept_queue_mutex); + + return ret; +} + +static void hvsock_addr_init(struct sockaddr_hv *addr, uuid_le service_id) +{ + memset(addr, 0, sizeof(*addr)); + addr->shv_family = AF_HYPERV; + addr->shv_service_id = service_id; +} + +static int hvsock_addr_validate(const struct sockaddr_hv *addr) +{ + if (!addr) + return -EFAULT; + + if (addr->shv_family != AF_HYPERV) + return -EAFNOSUPPORT; + + if (addr->reserved != 0) + return -EINVAL; + + return 0; +} + +static bool hvsock_addr_bound(const struct sockaddr_hv *addr) +{ + return !uuid_equals(addr->shv_service_id, SHV_SERVICE_ID_ANY); +} + +static int hvsock_addr_cast(const struct sockaddr *addr, size_t len, + struct sockaddr_hv **out_addr) +{ + if (len < sizeof(**out_addr)) + return -EFAULT; + + *out_addr = (struct sockaddr_hv *)addr; + return hvsock_addr_validate(*out_addr); +} + +static int __hvsock_do_bind(struct hvsock_sock *hvsk, + struct sockaddr_hv *addr) +{ + struct sockaddr_hv hv_addr; + int ret = 0; + + hvsock_addr_init(&hv_addr, addr->shv_service_id); + + mutex_lock(&hvsock_mutex); + + if (uuid_equals(addr->shv_service_id, SHV_SERVICE_ID_ANY)) { + do { + uuid_le_gen(&hv_addr.shv_service_id); + } while (hvsock_find_bound_socket(&hv_addr)); + } else { + if (hvsock_find_bound_socket(&hv_addr)) { + ret = -EADDRINUSE; + goto out; + } + } + + hvsock_addr_init(&hvsk->local_addr, hv_addr.shv_service_id); + + sock_hold(&hvsk->sk); + list_add(&hvsk->bound_list, &hvsock_bound_list); +out: + mutex_unlock(&hvsock_mutex); + + return ret; +} + +static int __hvsock_bind(struct sock *sk, struct sockaddr_hv *addr) +{ + struct hvsock_sock *hvsk = sk_to_hvsock(sk); + int ret; + + if (hvsock_addr_bound(&hvsk->local_addr)) + return -EINVAL; + + switch (sk->sk_socket->type) { + case SOCK_STREAM: + ret = __hvsock_do_bind(hvsk, addr); + break; + + default: + ret = -EINVAL; + break; + } + + return ret; +} + +/* Autobind this socket to the local address if necessary. */ +static int hvsock_auto_bind(struct hvsock_sock *hvsk) +{ + struct sock *sk = hvsock_to_sk(hvsk); + struct sockaddr_hv local_addr; + + if (hvsock_addr_bound(&hvsk->local_addr)) + return 0; + hvsock_addr_init(&local_addr, SHV_SERVICE_ID_ANY); + return __hvsock_bind(sk, &local_addr); +} + +static void hvsock_sk_destruct(struct sock *sk) +{ + struct hvsock_sock *hvsk = sk_to_hvsock(sk); + struct vmbus_channel *channel = hvsk->channel; + + kfree(hvsk->send); + kfree(hvsk->recv); + atomic_dec(&total_num_hvsock); + + if (!channel) + return; + + vmbus_hvsock_device_unregister(channel); +} + +static void __hvsock_release(struct sock *sk) +{ + struct hvsock_sock *hvsk; + struct sock *pending; + + hvsk = sk_to_hvsock(sk); + + mutex_lock(&hvsock_mutex); + + if (!list_empty(&hvsk->bound_list)) { + list_del_init(&hvsk->bound_list); + sock_put(&hvsk->sk); + } + + if (!list_empty(&hvsk->connected_list)) { + list_del_init(&hvsk->connected_list); + sock_put(&hvsk->sk); + } + + mutex_unlock(&hvsock_mutex); + + lock_sock(sk); + sock_orphan(sk); + sk->sk_shutdown = SHUTDOWN_MASK; + + /* Clean up any sockets that never were accepted. */ + while ((pending = hvsock_dequeue_accept(sk)) != NULL) { + __hvsock_release(pending); + sock_put(pending); + } + + release_sock(sk); + sock_put(sk); +} + +static int hvsock_release(struct socket *sock) +{ + /* If accept() is interrupted by a signal, the temporary socket + * struct's sock->sk is NULL. + */ + if (sock->sk) { + __hvsock_release(sock->sk); + sock->sk = NULL; + } + + sock->state = SS_FREE; + return 0; +} + +static int hvsock_create(struct net *net, struct socket *sock, + gfp_t priority, unsigned short type, + struct sock **sk) +{ + struct hvsock_send_buf *send = NULL; + struct hvsock_recv_buf *recv = NULL; + struct hvsock_sock *hvsk; + int ret = -EMFILE; + int num_hvsock; + + num_hvsock = atomic_inc_return(&total_num_hvsock); + if (num_hvsock > max_socket_number) + goto err; + + ret = -ENOMEM; + send = kmalloc(sizeof(*send), GFP_KERNEL); + recv = kmalloc(sizeof(*recv), GFP_KERNEL); + if (!send || !recv) + goto err; + + *sk = sk_alloc(net, AF_HYPERV, priority, &hvsock_proto, 0); + if (!*sk) + goto err; + + sock_init_data(sock, *sk); + + /* (*sk)->sk_type is normally set in sock_init_data, but only if sock + * is non-NULL. We make sure that our sockets always have a type by + * setting it here if needed. + */ + if (!sock) + (*sk)->sk_type = type; + + (*sk)->sk_destruct = hvsock_sk_destruct; + + /* Looks stream-based socket doesn't need this. */ + (*sk)->sk_backlog_rcv = NULL; + + (*sk)->sk_state = 0; + sock_reset_flag(*sk, SOCK_DONE); + + hvsk = sk_to_hvsock(*sk); + + hvsk->send = send; + hvsk->recv = recv; + + hvsock_addr_init(&hvsk->local_addr, SHV_SERVICE_ID_ANY); + hvsock_addr_init(&hvsk->remote_addr, SHV_SERVICE_ID_ANY); + + INIT_LIST_HEAD(&hvsk->bound_list); + INIT_LIST_HEAD(&hvsk->connected_list); + + INIT_LIST_HEAD(&hvsk->accept_queue); + mutex_init(&hvsk->accept_queue_mutex); + + hvsk->peer_shutdown = 0; + + hvsk->recv->data_len = 0; + hvsk->recv->data_offset = 0; + + return 0; +err: + atomic_dec(&total_num_hvsock); + kfree(send); + kfree(recv); + *sk = NULL; + return ret; +} + +static int hvsock_bind(struct socket *sock, struct sockaddr *addr, + int addr_len) +{ + struct sockaddr_hv *hv_addr; + struct sock *sk; + int ret; + + sk = sock->sk; + + if (hvsock_addr_cast(addr, addr_len, &hv_addr) != 0) + return -EINVAL; + + if (!uuid_equals(hv_addr->shv_vm_id, NULL_UUID_LE)) + return -EINVAL; + + lock_sock(sk); + ret = __hvsock_bind(sk, hv_addr); + release_sock(sk); + + return ret; +} + +static int hvsock_getname(struct socket *sock, + struct sockaddr *addr, int *addr_len, int peer) +{ + struct sockaddr_hv *hv_addr; + struct hvsock_sock *hvsk; + struct sock *sk; + int ret; + + sk = sock->sk; + hvsk = sk_to_hvsock(sk); + ret = 0; + + lock_sock(sk); + + if (peer) { + if (sock->state != SS_CONNECTED) { + ret = -ENOTCONN; + goto out; + } + hv_addr = &hvsk->remote_addr; + } else { + hv_addr = &hvsk->local_addr; + } + + __sockaddr_check_size(sizeof(*hv_addr)); + + memcpy(addr, hv_addr, sizeof(*hv_addr)); + *addr_len = sizeof(*hv_addr); + +out: + release_sock(sk); + return ret; +} + +static void get_ringbuffer_rw_status(struct vmbus_channel *channel, + bool *can_read, bool *can_write) +{ + u32 avl_read_bytes, avl_write_bytes, dummy; + + if (can_read) { + hv_get_ringbuffer_availbytes(&channel->inbound, + &avl_read_bytes, + &dummy); + /* 0-size payload means FIN */ + *can_read = avl_read_bytes >= HVSOCK_PKT_LEN(0); + } + + if (can_write) { + hv_get_ringbuffer_availbytes(&channel->outbound, + &dummy, + &avl_write_bytes); + + *can_write = avl_write_bytes > + HVSOCK_PKT_LEN(HVSOCK_SND_THRESHOLD); + } +} + +static size_t get_ringbuffer_writable_bytes(struct vmbus_channel *channel) +{ + u32 avl_write_bytes, dummy; + size_t ret; + + hv_get_ringbuffer_availbytes(&channel->outbound, + &dummy, + &avl_write_bytes); + + if (avl_write_bytes < HVSOCK_PKT_LEN(1) + HVSOCK_PKT_LEN(0)) + return 0; + + /* The ringbuffer mustn't be 100% full, and we should reserve a + * zero-length-payload packet for the FIN: see hv_ringbuffer_write() + * and hvsock_shutdown(). + */ + ret = avl_write_bytes - HVSOCK_PKT_LEN(1) - HVSOCK_PKT_LEN(0); + + return round_down(ret, 8); +} + +static int hvsock_send_data(struct vmbus_channel *channel, + struct hvsock_sock *hvsk, + size_t to_write) +{ + hvsk->send->hdr.pkt_type = 1; + hvsk->send->hdr.data_size = to_write; + return vmbus_sendpacket(channel, &hvsk->send->hdr, + sizeof(hvsk->send->hdr) + to_write, + 0, VM_PKT_DATA_INBAND, 0); +} + +static int hvsock_recv_data(struct vmbus_channel *channel, + struct hvsock_sock *hvsk, + size_t *payload_len) +{ + u32 buffer_actual_len; + u64 dummy_req_id; + int ret; + + ret = vmbus_recvpacket(channel, &hvsk->recv->hdr, + sizeof(hvsk->recv->hdr) + + sizeof(hvsk->recv->buf), + &buffer_actual_len, &dummy_req_id); + if (ret != 0 || buffer_actual_len <= sizeof(hvsk->recv->hdr)) + *payload_len = 0; + else + *payload_len = hvsk->recv->hdr.data_size; + + return ret; +} + +static int hvsock_shutdown(struct socket *sock, int mode) +{ + struct hvsock_sock *hvsk; + struct sock *sk; + + if (mode < SHUT_RD || mode > SHUT_RDWR) + return -EINVAL; + /* This maps: + * SHUT_RD (0) -> RCV_SHUTDOWN (1) + * SHUT_WR (1) -> SEND_SHUTDOWN (2) + * SHUT_RDWR (2) -> SHUTDOWN_MASK (3) + */ + ++mode; + + if (sock->state != SS_CONNECTED) + return -ENOTCONN; + + sock->state = SS_DISCONNECTING; + + sk = sock->sk; + + lock_sock(sk); + + sk->sk_shutdown |= mode; + sk->sk_state_change(sk); + + if (mode & SEND_SHUTDOWN) { + hvsk = sk_to_hvsock(sk); + /* It can't fail: see get_ringbuffer_writable_bytes(). */ + (void)hvsock_send_data(hvsk->channel, hvsk, 0); + } + + release_sock(sk); + + return 0; +} + +static unsigned int hvsock_poll(struct file *file, struct socket *sock, + poll_table *wait) +{ + struct vmbus_channel *channel; + bool can_read, can_write; + struct hvsock_sock *hvsk; + struct sock *sk; + unsigned int mask; + + sk = sock->sk; + hvsk = sk_to_hvsock(sk); + + poll_wait(file, sk_sleep(sk), wait); + mask = 0; + + if (sk->sk_err) + /* Signify that there has been an error on this socket. */ + mask |= POLLERR; + + /* INET sockets treat local write shutdown and peer write shutdown as a + * case of POLLHUP set. + */ + if ((sk->sk_shutdown == SHUTDOWN_MASK) || + ((sk->sk_shutdown & SEND_SHUTDOWN) && + (hvsk->peer_shutdown & SEND_SHUTDOWN))) { + mask |= POLLHUP; + } + + if (sk->sk_shutdown & RCV_SHUTDOWN || + hvsk->peer_shutdown & SEND_SHUTDOWN) { + mask |= POLLRDHUP; + } + + lock_sock(sk); + + /* Listening sockets that have connections in their accept + * queue can be read. + */ + if (sk->sk_state == SS_LISTEN && !hvsock_is_accept_queue_empty(sk)) + mask |= POLLIN | POLLRDNORM; + + /* The mutex is to against hvsock_open_connection() */ + mutex_lock(&hvsock_mutex); + + channel = hvsk->channel; + if (channel) { + /* If there is something in the queue then we can read */ + get_ringbuffer_rw_status(channel, &can_read, &can_write); + + if (!can_read && hvsk->recv->data_len > 0) + can_read = true; + + if (!(sk->sk_shutdown & RCV_SHUTDOWN) && can_read) + mask |= POLLIN | POLLRDNORM; + } else { + can_read = false; + can_write = false; + } + + mutex_unlock(&hvsock_mutex); + + /* Sockets whose connections have been closed terminated should + * also be considered read, and we check the shutdown flag for that. + */ + if (sk->sk_shutdown & RCV_SHUTDOWN || + hvsk->peer_shutdown & SEND_SHUTDOWN) { + mask |= POLLIN | POLLRDNORM; + } + + /* Connected sockets that can produce data can be written. */ + if (sk->sk_state == SS_CONNECTED && can_write && + !(sk->sk_shutdown & SEND_SHUTDOWN)) { + /* Remove POLLWRBAND since INET sockets are not setting it. + */ + mask |= POLLOUT | POLLWRNORM; + } + + /* Simulate INET socket poll behaviors, which sets + * POLLOUT|POLLWRNORM when peer is closed and nothing to read, + * but local send is not shutdown. + */ + if (sk->sk_state == SS_UNCONNECTED && + !(sk->sk_shutdown & SEND_SHUTDOWN)) + mask |= POLLOUT | POLLWRNORM; + + release_sock(sk); + + return mask; +} + +/* This function runs in the tasklet context of process_chn_event() */ +static void hvsock_on_channel_cb(void *ctx) +{ + struct sock *sk = (struct sock *)ctx; + struct hvsock_sock *hvsk = sk_to_hvsock(sk); + struct vmbus_channel *channel = hvsk->channel; + bool can_read, can_write; + + if (!channel) { + WARN_ONCE(1, "NULL channel! There is a programming bug.\n"); + return; + } + + get_ringbuffer_rw_status(channel, &can_read, &can_write); + + if (can_read) + sk->sk_data_ready(sk); + + if (can_write) + sk->sk_write_space(sk); +} + +static void hvsock_close_connection(struct vmbus_channel *channel) +{ + struct hvsock_sock *hvsk; + struct sock *sk; + + mutex_lock(&hvsock_mutex); + + sk = hvsock_find_connected_socket_by_channel(channel); + + /* The guest has already closed the connection? */ + if (!sk) + goto out; + + sk->sk_state = SS_UNCONNECTED; + sock_set_flag(sk, SOCK_DONE); + + hvsk = sk_to_hvsock(sk); + hvsk->peer_shutdown |= SEND_SHUTDOWN | RCV_SHUTDOWN; + + sk->sk_state_change(sk); +out: + mutex_unlock(&hvsock_mutex); +} + +static int hvsock_open_connection(struct vmbus_channel *channel) +{ + struct hvsock_sock *hvsk, *new_hvsk; + struct sockaddr_hv hv_addr; + struct sock *sk, *new_sk; + unsigned char conn_from_host; + + uuid_le *instance, *service_id; + int ret; + + instance = &channel->offermsg.offer.if_instance; + service_id = &channel->offermsg.offer.if_type; + + /* The first byte != 0 means the host initiated the connection. */ + conn_from_host = channel->offermsg.offer.u.pipe.user_def[0]; + + mutex_lock(&hvsock_mutex); + + hvsock_addr_init(&hv_addr, conn_from_host ? *service_id : *instance); + sk = hvsock_find_bound_socket(&hv_addr); + + if (!sk || (conn_from_host && sk->sk_state != SS_LISTEN) || + (!conn_from_host && sk->sk_state != SS_CONNECTING)) { + ret = -ENXIO; + goto out; + } + + if (conn_from_host) { + if (sk->sk_ack_backlog >= sk->sk_max_ack_backlog) { + ret = -EMFILE; + goto out; + } + + ret = hvsock_create(sock_net(sk), NULL, GFP_KERNEL, + sk->sk_type, &new_sk); + if (ret != 0) + goto out; + + new_sk->sk_state = SS_CONNECTING; + new_hvsk = sk_to_hvsock(new_sk); + new_hvsk->channel = channel; + hvsock_addr_init(&new_hvsk->local_addr, *service_id); + hvsock_addr_init(&new_hvsk->remote_addr, *instance); + } else { + hvsk = sk_to_hvsock(sk); + hvsk->channel = channel; + } + + set_channel_read_state(channel, false); + ret = vmbus_open(channel, send_ring_page * PAGE_SIZE, + recv_ring_page * PAGE_SIZE, NULL, 0, + hvsock_on_channel_cb, conn_from_host ? new_sk : sk); + if (ret != 0) { + if (conn_from_host) { + new_hvsk->channel = NULL; + sock_put(new_sk); + } else { + hvsk->channel = NULL; + } + goto out; + } + + vmbus_set_chn_rescind_callback(channel, hvsock_close_connection); + set_channel_pending_send_size(channel, + HVSOCK_PKT_LEN(HVSOCK_SND_THRESHOLD)); + + if (conn_from_host) { + new_sk->sk_state = SS_CONNECTED; + + sock_hold(&new_hvsk->sk); + list_add(&new_hvsk->connected_list, &hvsock_connected_list); + + hvsock_enqueue_accept(sk, new_sk); + } else { + sk->sk_state = SS_CONNECTED; + sk->sk_socket->state = SS_CONNECTED; + + sock_hold(&hvsk->sk); + list_add(&hvsk->connected_list, &hvsock_connected_list); + } + + sk->sk_state_change(sk); +out: + mutex_unlock(&hvsock_mutex); + return ret; +} + +static void hvsock_connect_timeout(struct work_struct *work) +{ + struct hvsock_sock *hvsk; + struct sock *sk; + + hvsk = container_of(work, struct hvsock_sock, dwork.work); + sk = hvsock_to_sk(hvsk); + + lock_sock(sk); + if ((sk->sk_state == SS_CONNECTING) && + (sk->sk_shutdown != SHUTDOWN_MASK)) { + sk->sk_state = SS_UNCONNECTED; + sk->sk_err = ETIMEDOUT; + sk->sk_error_report(sk); + } + release_sock(sk); + + sock_put(sk); +} + +static int hvsock_connect_wait(struct socket *sock, + int flags, int current_ret) +{ + struct sock *sk = sock->sk; + struct hvsock_sock *hvsk = sk_to_hvsock(sk); + + int ret = current_ret; + + long timeout = 30 * HZ; + DEFINE_WAIT(wait); + + prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); + + while (sk->sk_state != SS_CONNECTED && sk->sk_err == 0) { + if (flags & O_NONBLOCK) { + /* If we're not going to block, we schedule a timeout + * function to generate a timeout on the connection + * attempt, in case the peer doesn't respond in a + * timely manner. We hold on to the socket until the + * timeout fires. + */ + sock_hold(sk); + INIT_DELAYED_WORK(&hvsk->dwork, + hvsock_connect_timeout); + schedule_delayed_work(&hvsk->dwork, timeout); + + /* Skip ahead to preserve error code set above. */ + goto out_wait; + } + + release_sock(sk); + timeout = schedule_timeout(timeout); + lock_sock(sk); + + if (signal_pending(current)) { + ret = sock_intr_errno(timeout); + goto out_wait_error; + } else if (timeout == 0) { + ret = -ETIMEDOUT; + goto out_wait_error; + } + + prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); + } + + ret = sk->sk_err ? -sk->sk_err : 0; + +out_wait_error: + if (ret < 0) { + sk->sk_state = SS_UNCONNECTED; + sock->state = SS_UNCONNECTED; + } +out_wait: + finish_wait(sk_sleep(sk), &wait); + return ret; +} + +static int hvsock_connect(struct socket *sock, struct sockaddr *addr, + int addr_len, int flags) +{ + struct sockaddr_hv *remote_addr; + struct hvsock_sock *hvsk; + struct sock *sk; + int ret = 0; + + sk = sock->sk; + hvsk = sk_to_hvsock(sk); + + lock_sock(sk); + + switch (sock->state) { + case SS_CONNECTED: + ret = -EISCONN; + goto out; + case SS_DISCONNECTING: + ret = -EINVAL; + goto out; + case SS_CONNECTING: + /* This continues on so we can move sock into the SS_CONNECTED + * state once the connection has completed (at which point err + * will be set to zero also). Otherwise, we will either wait + * for the connection or return -EALREADY should this be a + * non-blocking call. + */ + ret = -EALREADY; + break; + default: + if ((sk->sk_state == SS_LISTEN) || + hvsock_addr_cast(addr, addr_len, &remote_addr) != 0) { + ret = -EINVAL; + goto out; + } + + /* Set the remote address that we are connecting to. */ + memcpy(&hvsk->remote_addr, remote_addr, + sizeof(hvsk->remote_addr)); + + ret = hvsock_auto_bind(hvsk); + if (ret) + goto out; + + sk->sk_state = SS_CONNECTING; + + ret = vmbus_send_tl_connect_request( + &hvsk->local_addr.shv_service_id, + &hvsk->remote_addr.shv_service_id); + if (ret < 0) + goto out; + + /* Mark sock as connecting and set the error code to in + * progress in case this is a non-blocking connect. + */ + sock->state = SS_CONNECTING; + ret = -EINPROGRESS; + } + + ret = hvsock_connect_wait(sock, flags, ret); +out: + release_sock(sk); + return ret; +} + +static int hvsock_accept_wait(struct sock *listener, + struct socket *newsock, int flags) +{ + struct hvsock_sock *hvconnected; + struct sock *connected; + + DEFINE_WAIT(wait); + long timeout; + + int ret = 0; + + /* Wait for children sockets to appear; these are the new sockets + * created upon connection establishment. + */ + timeout = sock_sndtimeo(listener, flags & O_NONBLOCK); + prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE); + + while ((connected = hvsock_dequeue_accept(listener)) == NULL && + listener->sk_err == 0) { + release_sock(listener); + timeout = schedule_timeout(timeout); + lock_sock(listener); + + if (signal_pending(current)) { + ret = sock_intr_errno(timeout); + goto out_wait; + } else if (timeout == 0) { + ret = -EAGAIN; + goto out_wait; + } + + prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE); + } + + if (listener->sk_err) + ret = -listener->sk_err; + + if (connected) { + lock_sock(connected); + hvconnected = sk_to_hvsock(connected); + + if (ret) { + release_sock(connected); + sock_put(connected); + } else { + newsock->state = SS_CONNECTED; + sock_graft(connected, newsock); + release_sock(connected); + sock_put(connected); + } + } + +out_wait: + finish_wait(sk_sleep(listener), &wait); + return ret; +} + +static +int hvsock_accept(struct socket *sock, struct socket *newsock, int flags) +{ + struct sock *listener; + int ret; + + listener = sock->sk; + + lock_sock(listener); + + if (sock->type != SOCK_STREAM) { + ret = -EOPNOTSUPP; + goto out; + } + + if (listener->sk_state != SS_LISTEN) { + ret = -EINVAL; + goto out; + } + + ret = hvsock_accept_wait(listener, newsock, flags); +out: + release_sock(listener); + return ret; +} + +static int hvsock_listen(struct socket *sock, int backlog) +{ + struct hvsock_sock *hvsk; + struct sock *sk; + int ret = 0; + + sk = sock->sk; + lock_sock(sk); + + if (sock->type != SOCK_STREAM) { + ret = -EOPNOTSUPP; + goto out; + } + + if (sock->state != SS_UNCONNECTED) { + ret = -EINVAL; + goto out; + } + + if (backlog <= 0) { + ret = -EINVAL; + goto out; + } + /* This is an artificial limit */ + if (backlog > 128) + backlog = 128; + + hvsk = sk_to_hvsock(sk); + if (!hvsock_addr_bound(&hvsk->local_addr)) { + ret = -EINVAL; + goto out; + } + + sk->sk_ack_backlog = 0; + sk->sk_max_ack_backlog = backlog; + sk->sk_state = SS_LISTEN; +out: + release_sock(sk); + return ret; +} + +static +int hvsock_sendmsg_wait(struct sock *sk, struct msghdr *msg, size_t len) +{ + struct hvsock_sock *hvsk = sk_to_hvsock(sk); + struct vmbus_channel *channel = hvsk->channel; + + size_t total_to_write = len; + size_t total_written = 0; + bool can_write; + + int ret = 0; + + DEFINE_WAIT(wait); + long timeout; + + timeout = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); + prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); + + while (total_to_write > 0) { + size_t to_write, max_writable; + + while (1) { + get_ringbuffer_rw_status(channel, NULL, &can_write); + + if (can_write || sk->sk_err != 0 || + (sk->sk_shutdown & SEND_SHUTDOWN) || + (hvsk->peer_shutdown & RCV_SHUTDOWN)) + break; + + /* Don't wait for non-blocking sockets. */ + if (timeout == 0) { + ret = -EAGAIN; + goto out_wait; + } + + release_sock(sk); + + timeout = schedule_timeout(timeout); + + lock_sock(sk); + if (signal_pending(current)) { + ret = sock_intr_errno(timeout); + goto out_wait; + } else if (timeout == 0) { + ret = -EAGAIN; + goto out_wait; + } + + prepare_to_wait(sk_sleep(sk), &wait, + TASK_INTERRUPTIBLE); + } + + /* These checks occur both as part of and after the loop + * conditional since we need to check before and after + * sleeping. + */ + if (sk->sk_err) { + ret = -sk->sk_err; + goto out_wait; + } else if ((sk->sk_shutdown & SEND_SHUTDOWN) || + (hvsk->peer_shutdown & RCV_SHUTDOWN)) { + ret = -EPIPE; + goto out_wait; + } + + /* Note: that write will only write as many bytes as possible + * in the ringbuffer. It is the caller's responsibility to + * check how many bytes we actually wrote. + */ + do { + max_writable = get_ringbuffer_writable_bytes(channel); + if (max_writable == 0) + goto out_wait; + + to_write = min_t(size_t, HVSOCK_SND_BUF_SZ, + total_to_write); + if (to_write > max_writable) + to_write = max_writable; + + ret = memcpy_from_msg(hvsk->send->buf, msg, to_write); + if (ret != 0) + goto out_wait; + + ret = hvsock_send_data(channel, hvsk, to_write); + if (ret != 0) + goto out_wait; + + total_written += to_write; + total_to_write -= to_write; + } while (total_to_write > 0); + } + +out_wait: + if (total_written > 0) + ret = total_written; + + finish_wait(sk_sleep(sk), &wait); + return ret; +} + +static int hvsock_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) +{ + struct hvsock_sock *hvsk; + struct sock *sk; + int ret; + + if (len == 0) + return -EINVAL; + + if (msg->msg_flags & ~MSG_DONTWAIT) { + pr_err("%s: unsupported flags=0x%x\n", __func__, + msg->msg_flags); + return -EOPNOTSUPP; + } + + sk = sock->sk; + hvsk = sk_to_hvsock(sk); + + lock_sock(sk); + + /* Callers should not provide a destination with stream sockets. */ + if (msg->msg_namelen) { + ret = -EOPNOTSUPP; + goto out; + } + + /* Send data only if both sides are not shutdown in the direction. */ + if (sk->sk_shutdown & SEND_SHUTDOWN || + hvsk->peer_shutdown & RCV_SHUTDOWN) { + ret = -EPIPE; + goto out; + } + + if (sk->sk_state != SS_CONNECTED || + !hvsock_addr_bound(&hvsk->local_addr)) { + ret = -ENOTCONN; + goto out; + } + + if (!hvsock_addr_bound(&hvsk->remote_addr)) { + ret = -EDESTADDRREQ; + goto out; + } + + ret = hvsock_sendmsg_wait(sk, msg, len); +out: + release_sock(sk); + + /* ret is a bigger-than-0 total_written or a negative err code. */ + if (ret == 0) { + WARN(1, "unexpected return value of 0\n"); + ret = -EIO; + } + + return ret; +} + +static int hvsock_recvmsg_wait(struct sock *sk, struct msghdr *msg, + size_t len, int flags) +{ + struct hvsock_sock *hvsk = sk_to_hvsock(sk); + struct vmbus_channel *channel = hvsk->channel; + + size_t to_read, total_to_read = len; + size_t copied = 0; + bool can_read; + + int ret = 0; + + DEFINE_WAIT(wait); + long timeout; + + timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); + prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); + + while (1) { + bool need_refill = hvsk->recv->data_len == 0; + + if (need_refill) + get_ringbuffer_rw_status(channel, &can_read, NULL); + else + can_read = true; + + if (can_read) { + size_t payload_len; + + if (need_refill) { + ret = hvsock_recv_data(channel, hvsk, + &payload_len); + if (ret != 0 || + payload_len > HVSOCK_RCV_BUF_SZ) { + ret = -EIO; + goto out_wait; + } + + if (payload_len == 0) { + ret = copied; + goto out_wait; + } + + hvsk->recv->data_len = payload_len; + hvsk->recv->data_offset = 0; + } + + to_read = min_t(size_t, total_to_read, + hvsk->recv->data_len); + + ret = memcpy_to_msg(msg, hvsk->recv->buf + + hvsk->recv->data_offset, + to_read); + if (ret != 0) + break; + + copied += to_read; + total_to_read -= to_read; + + hvsk->recv->data_len -= to_read; + + if (hvsk->recv->data_len == 0) + hvsk->recv->data_offset = 0; + else + hvsk->recv->data_offset += to_read; + + if (total_to_read == 0) + break; + } else { + if (sk->sk_err || (sk->sk_shutdown & RCV_SHUTDOWN) || + (hvsk->peer_shutdown & SEND_SHUTDOWN)) + break; + + /* Don't wait for non-blocking sockets. */ + if (timeout == 0) { + ret = -EAGAIN; + break; + } + + if (copied > 0) + break; + + release_sock(sk); + timeout = schedule_timeout(timeout); + lock_sock(sk); + + if (signal_pending(current)) { + ret = sock_intr_errno(timeout); + break; + } else if (timeout == 0) { + ret = -EAGAIN; + break; + } + + prepare_to_wait(sk_sleep(sk), &wait, + TASK_INTERRUPTIBLE); + } + } + + if (sk->sk_err) + ret = -sk->sk_err; + else if (sk->sk_shutdown & RCV_SHUTDOWN) + ret = 0; + + if (copied > 0) { + ret = copied; + + /* If the other side has shutdown for sending and there + * is nothing more to read, then we modify the socket + * state. + */ + if ((hvsk->peer_shutdown & SEND_SHUTDOWN) && + hvsk->recv->data_len == 0) { + get_ringbuffer_rw_status(channel, &can_read, NULL); + if (!can_read) { + sk->sk_state = SS_UNCONNECTED; + sock_set_flag(sk, SOCK_DONE); + sk->sk_state_change(sk); + } + } + } +out_wait: + finish_wait(sk_sleep(sk), &wait); + return ret; +} + +static int hvsock_recvmsg(struct socket *sock, struct msghdr *msg, + size_t len, int flags) +{ + struct sock *sk = sock->sk; + int ret; + + lock_sock(sk); + + if (sk->sk_state != SS_CONNECTED) { + /* Recvmsg is supposed to return 0 if a peer performs an + * orderly shutdown. Differentiate between that case and when a + * peer has not connected or a local shutdown occurred with the + * SOCK_DONE flag. + */ + if (sock_flag(sk, SOCK_DONE)) + ret = 0; + else + ret = -ENOTCONN; + + goto out; + } + + /* We ignore msg->addr_name/len. */ + if (flags & ~MSG_DONTWAIT) { + pr_err("%s: unsupported flags=0x%x\n", __func__, flags); + ret = -EOPNOTSUPP; + goto out; + } + + /* We don't check peer_shutdown flag here since peer may actually shut + * down, but there can be data in the queue that a local socket can + * receive. + */ + if (sk->sk_shutdown & RCV_SHUTDOWN) { + ret = 0; + goto out; + } + + /* It is valid on Linux to pass in a zero-length receive buffer. This + * is not an error. We may as well bail out now. + */ + if (!len) { + ret = 0; + goto out; + } + + ret = hvsock_recvmsg_wait(sk, msg, len, flags); +out: + release_sock(sk); + return ret; +} + +static const struct proto_ops hvsock_ops = { + .family = PF_HYPERV, + .owner = THIS_MODULE, + .release = hvsock_release, + .bind = hvsock_bind, + .connect = hvsock_connect, + .socketpair = sock_no_socketpair, + .accept = hvsock_accept, + .getname = hvsock_getname, + .poll = hvsock_poll, + .ioctl = sock_no_ioctl, + .listen = hvsock_listen, + .shutdown = hvsock_shutdown, + .setsockopt = sock_no_setsockopt, + .getsockopt = sock_no_getsockopt, + .sendmsg = hvsock_sendmsg, + .recvmsg = hvsock_recvmsg, + .mmap = sock_no_mmap, + .sendpage = sock_no_sendpage, +}; + +static int hvsock_create_sock(struct net *net, struct socket *sock, + int protocol, int kern) +{ + struct sock *sk; + + if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN)) + return -EPERM; + + if (protocol != 0 && protocol != SHV_PROTO_RAW) + return -EPROTONOSUPPORT; + + switch (sock->type) { + case SOCK_STREAM: + sock->ops = &hvsock_ops; + break; + default: + return -ESOCKTNOSUPPORT; + } + + sock->state = SS_UNCONNECTED; + + return hvsock_create(net, sock, GFP_KERNEL, 0, &sk); +} + +static const struct net_proto_family hvsock_family_ops = { + .family = AF_HYPERV, + .create = hvsock_create_sock, + .owner = THIS_MODULE, +}; + +static int hvsock_probe(struct hv_device *hdev, + const struct hv_vmbus_device_id *dev_id) +{ + struct vmbus_channel *channel = hdev->channel; + + /* We ignore the error return code to suppress the unnecessary + * error message in vmbus_probe(): on error the host will rescind + * the offer in 30 seconds and we can do cleanup at that time. + */ + (void)hvsock_open_connection(channel); + + return 0; +} + +static int hvsock_remove(struct hv_device *hdev) +{ + struct vmbus_channel *channel = hdev->channel; + + vmbus_close(channel); + + return 0; +} + +/* It's not really used. See vmbus_match() and vmbus_probe(). */ +static const struct hv_vmbus_device_id id_table[] = { + {}, +}; + +static struct hv_driver hvsock_drv = { + .name = "hv_sock", + .hvsock = true, + .id_table = id_table, + .probe = hvsock_probe, + .remove = hvsock_remove, +}; + +static int __init hvsock_init(void) +{ + int ret; + + if (send_ring_page < DEF_RINGBUFFER_PAGES_HVSOCK_SND) + send_ring_page = DEF_RINGBUFFER_PAGES_HVSOCK_SND; + + if (recv_ring_page < DEF_RINGBUFFER_PAGES_HVSOCK_RCV) + recv_ring_page = DEF_RINGBUFFER_PAGES_HVSOCK_RCV; + + /* Hyper-V Sockets requires at least VMBus 4.0 */ + if ((vmbus_proto_version >> 16) < 4) { + pr_err("failed to load: VMBus 4 or later is required\n"); + return -ENODEV; + } + + ret = vmbus_driver_register(&hvsock_drv); + if (ret) { + pr_err("failed to register hv_sock driver\n"); + return ret; + } + + ret = proto_register(&hvsock_proto, 0); + if (ret) { + pr_err("failed to register protocol\n"); + goto unreg_hvsock_drv; + } + + ret = sock_register(&hvsock_family_ops); + if (ret) { + pr_err("failed to register address family\n"); + goto unreg_proto; + } + + return 0; + +unreg_proto: + proto_unregister(&hvsock_proto); +unreg_hvsock_drv: + vmbus_driver_unregister(&hvsock_drv); + return ret; +} + +static void __exit hvsock_exit(void) +{ + sock_unregister(AF_HYPERV); + proto_unregister(&hvsock_proto); + vmbus_driver_unregister(&hvsock_drv); +} + +module_init(hvsock_init); +module_exit(hvsock_exit); + +MODULE_DESCRIPTION("Hyper-V Sockets"); +MODULE_LICENSE("Dual BSD/GPL"); -- 2.7.4
