vsock-tcp (VM Socket TCP)

Header: udo/vsock-tcp.h

Table of contents (click to go)

Macros

Enums

Unions

Structs

1. udo_vsock_tcp

2. udo_vsock_tcp_server_create_info

3. udo_vsock_tcp_client_create_info

Functions

1. udo_vsock_tcp_server_create()

2. udo_vsock_tcp_server_accept()

3. udo_vsock_tcp_client_create()

4. udo_vsock_tcp_client_connect()

5. udo_vsock_tcp_client_send_data()

6. udo_vsock_tcp_get_fd()

7. udo_vsock_tcp_get_vcid()

8. udo_vsock_tcp_get_port()

9. udo_vsock_tcp_destroy()

10. udo_vsock_tcp_get_sizeof()

11. udo_vsock_tcp_get_local_vcid()

12. udo_vsock_tcp_recv_data()

13. udo_vsock_tcp_send_data()

API Documentation

Kernel Modules

On Host Machine

sudo modprobe -a vhost_vsock vsock_loopback

Guest Machine Kernel Config Symbols

CONFIG_PCI=Y
CONFIG_VIRTIO_MENU=y
CONFIG_VIRTIO_PCI=y
CONFIG_VIRTIO_BALLON=y
CONFIG_VSOCKETS_DIAG=y

CONFIG_NET=y
CONFIG_VSOCKETS=y
CONFIG_VIRTIO_VSOCKETS=y

udo_vsock_tcp (private)

Structure defining UDO VM Socket TCP context.

struct udo_vsock_tcp

struct udo_log_error_struct err;

bool free;

int fd;

uint32_t vcid;

int port;

struct sockaddr_vm addr;

err

Stores information about the error that occured

for the given context and may later be retrieved

by caller.

free

If structure allocated with calloc(3) member will be

set to true so that, we know to call free(3) when

destroying the context.

fd

File descriptor to the open VM socket.

vcid

VM Context Identifier.

port

Network port number to connect(2) to or accept(2) from.

addr

Stores byte information about the VM socket context.

Is used for client connect(2) and server accept(2).

---

udo_vsock_tcp_server_create_info

Structure passed to udo_vsock_tcp_server_create()

used to define how to create the server.

struct udo_vsock_tcp_server_create_info

uint32_t vcid;

int port;

int connections;

vcid

VM Context Identifier to accept(2) with.

port

Network port to accept(2) with.

connections

Amount of connections that may be queued

at a given moment.

udo_vsock_tcp_server_create

struct udo_vsock_tcp *udo_vsock_tcp_server_create(struct udo_vsock_tcp *vsock, const void *vsock_info);

Creates a VM socket that may be utilized for server socket operations.

Param	Decription
vsock	May be NULL or a pointer to a struct udo_vsock_tcp. If NULL memory will be allocated and return to caller. If not NULL address passed will be used to store the newly created struct udo_vsock_tcp context.
vsock_info	Implementation uses a pointer to a struct udo_vsock_tcp_server_create_info.

Returns:

on success: Pointer to a struct udo_vsock_tcp

on failure: NULL

---

udo_vsock_tcp_server_accept

int udo_vsock_tcp_server_accept(struct udo_vsock_tcp *vsock, struct sockaddr_vm *addr);

Accepts client connections returns open

file descriptor to the connected client.

Param	Decription
vsock	Must pass a pointer to a struct udo_vsock_tcp.
addr	May be NULL or a pointer to a struct sockaddr_vm If not NULL addr is filled in via accept(2) call.

Returns:

on success: Open file descriptor to accepted client

on failure: -1

---

udo_vsock_tcp_client_create_info

Structure passed to udo_vsock_tcp_client_create()

used to define how to create the client.

struct udo_vsock_tcp_client_create_info

uint32_t vcid;

int port;

vcid

VM Context Identifier to connect(2)/send(2) to.

port

Network port to connect(2)/send(2) to.

udo_vsock_tcp_client_create

struct udo_vsock_tcp *udo_vsock_tcp_client_create(struct udo_vsock_tcp *vsock, const void *vsock_info);

Creates a VM socket that may be utilized for client socket operations.

Param	Decription
vsock	May be NULL or a pointer to a struct udo_vsock_tcp. If NULL memory will be allocated and return to caller. If not NULL address passed will be used to store the newly created struct udo_vsock_tcp context.
vsock_info	Implementation uses a pointer to a struct udo_vsock_tcp_client_create_info.

Returns:

on success: Pointer to a struct udo_vsock_tcp

on failure: NULL

---

udo_vsock_tcp_client_connect

int udo_vsock_tcp_client_connect(struct udo_vsock_tcp *vsock);

Connects client socket to address provided via

call to udo_vsock_tcp_client_create().

Param	Decription
vsock	Must pass a pointer to a struct udo_vsock_tcp.

Returns:

on success: 0

on failure: -1

---

udo_vsock_tcp_client_send_data

ssize_t udo_vsock_tcp_client_send_data(struct udo_vsock_tcp *vsock, const void *data, const size_t size, const void *vsock_info);

Send data to client socket address provided via

call to udo_vsock_tcp_client_create().

Param	Decription
vsock	Must pass a pointer to a struct udo_vsock_tcp.
data	Pointer to buffer to send through socket.
size	Size of data to send through socket.
vsock_info	Reserved for future usage. For now used to set the flag argument of send(2).

Returns:

on success: Amount of bytes sent

on failure: # < 0

---

udo_vsock_tcp_get_fd

int udo_vsock_tcp_get_fd(struct udo_vsock_tcp *vsock);

Acquire VM socket file descriptor associated with

struct udo_vsock_tcp context.

Param	Decription
vsock	Must pass a pointer to a struct udo_vsock_tcp.

Returns:

on success: VM socket file descriptor

on failure: -1

---

udo_vsock_tcp_get_vcid

uint32_t udo_vsock_tcp_get_vcid(struct udo_vsock_tcp *vsock);

Acquire VM socket context identifier associated with

struct udo_vsock_tcp context.

Param	Decription
vsock	Must pass a pointer to a struct udo_vsock_tcp.

Returns:

on success: VM socket context identifier

on failure: UINT32_MAX

---

udo_vsock_tcp_get_port

int udo_vsock_tcp_get_port(struct udo_vsock_tcp *vsock);

Acquire network port associated with

struct udo_vsock_tcp context.

Param	Decription
vsock	Must pass a pointer to a struct udo_vsock_tcp.

Returns:

on success: Network port connected to context

on failure: -1

---

udo_vsock_tcp_destroy

void udo_vsock_tcp_destroy(struct udo_vsock_tcp *vsock);

Frees any allocated memory and closes FD’s (if open) created after

udo_vsock_tcp_server_create() or udo_vsock_tcp_client_create() call.

Param	Decription
vsock	Pointer to a valid struct udo_vsock_tcp.

---

udo_vsock_tcp_get_sizeof

int udo_vsock_tcp_get_sizeof(void);

Returns size of the internal structure. So,

if caller decides to allocate memory outside

of API interface they know the exact amount

of bytes.

Returns:

on success: sizeof(struct udo_vsock_tcp)

on failure: sizeof(struct udo_vsock_tcp)

---

udo_vsock_tcp_get_local_vcid

uint32_t udo_vsock_tcp_get_local_vcid(void);

Returns the local CID of the VM/Hypervisor after

acquiring it from /dev/vsock.

Returns:

on success: Local VM context identifer

on failure: UINT32_MAX

---

udo_vsock_tcp_recv_data

ssize_t udo_vsock_tcp_recv_data(const int sock_fd, void *data, const size_t size, const void *vsock_info);

Receive data from socket file descriptor.

Param	Decription
sock_fd	Socket file descriptor to receive data from.
data	Pointer to buffer to store data received from a socket.
size	Size of data to receive from a socket.
vsock_info	Reserved for future usage. For now used to set the flag argument of recv(2).

Returns:

on success: Amount of bytes received

on failure: # < 0

---

udo_vsock_tcp_send_data

ssize_t udo_vsock_tcp_send_data(const int sock_fd, const void *data, const size_t size, const void *vsock_info);

Send data to socket file descriptor.

Param	Decription
sock_fd	Socket file descriptor to send data to.
data	Pointer to buffer to send through socket.
size	Size of data to send through socket.
vsock_info	Reserved for future usage. For now used to set the flag argument of send(2).

Returns:

on success: Amount of bytes sent

on failure: # < 0

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