# virterror: error handling interfaces for the libvirt library

## virterror

virterror - error handling interfaces for the libvirt library

Provides the interfaces of the libvirt library to handle errors raised while using the library.

Author(s): Daniel Veillard <veillard@redhat.com>

## Synopsis

    typedef virError * virErrorPtr;
    typedef enum virErrorLevel;
    typedef enum virErrorDomain;
    typedef enum virErrorNumber;
    typedef struct _virError virError;
    int	virCopyLastError		(virErrorPtr to);
    void	virConnSetErrorFunc		(virConnectPtr conn,
    					 void * userData,
    					 virErrorFunc handler);
    void	virResetLastError		(void);
    typedef void virErrorFunc			(void * userData,
    					 virErrorPtr error);
    void	virResetError			(virErrorPtr err);
    virErrorPtr	virConnGetLastError	(virConnectPtr conn);
    void	virDefaultErrorFunc		(virErrorPtr err);
    virErrorPtr	virGetLastError		(void);
    void	virSetErrorFunc			(void * userData,
    					 virErrorFunc handler);
    int	virConnCopyLastError		(virConnectPtr conn,
    					 virErrorPtr to);
    void	virConnResetLastError		(virConnectPtr conn);

## Description

## Details

### Structure virError

    struct _virError {
        int	code	: The error code, a virErrorNumber
        int	domain	: What part of the library raised this error
        char *	message	: human-readable informative error message
        virErrorLevel	level	: how consequent is the error
        virConnectPtr	conn	: connection if available, deprecated see note above
        virDomainPtr	dom	: domain if available, deprecated see note above
        char *	str1	: extra string information
        char *	str2	: extra string information
        char *	str3	: extra string information
        int	int1	: extra number information
        int	int2	: extra number information
        virNetworkPtr	net	: network if available, deprecated see note above
    } virError;

### Enum virErrorDomain

    enum virErrorDomain {
        VIR_FROM_NONE = 0
        VIR_FROM_XEN = 1 /* Error at Xen hypervisor layer */
        VIR_FROM_XEND = 2 /* Error at connection with xend daemon */
        VIR_FROM_XENSTORE = 3 /* Error at connection with xen store */
        VIR_FROM_SEXPR = 4 /* Error in the S-Expression code */
        VIR_FROM_XML = 5 /* Error in the XML code */
        VIR_FROM_DOM = 6 /* Error when operating on a domain */
        VIR_FROM_RPC = 7 /* Error in the XML-RPC code */
        VIR_FROM_PROXY = 8 /* Error in the proxy code */
        VIR_FROM_CONF = 9 /* Error in the configuration file handling */
        VIR_FROM_QEMU = 10 /* Error at the QEMU daemon */
        VIR_FROM_NET = 11 /* Error when operating on a network */
        VIR_FROM_TEST = 12 /* Error from test driver */
        VIR_FROM_REMOTE = 13 /* Error from remote driver */
        VIR_FROM_OPENVZ = 14 /* Error from OpenVZ driver */
        VIR_FROM_XENXM = 15 /* Error at Xen XM layer */
        VIR_FROM_STATS_LINUX = 16 /* Error in the Linux Stats code */
        VIR_FROM_LXC = 17 /* Error from Linux Container driver */
        VIR_FROM_STORAGE = 18 /* Error from storage driver */
        VIR_FROM_NETWORK = 19 /* Error from network config */
        VIR_FROM_DOMAIN = 20 /* Error from domain config */
        VIR_FROM_UML = 21 /* Error at the UML driver */
        VIR_FROM_NODEDEV = 22 /* Error from node device monitor */
        VIR_FROM_XEN_INOTIFY = 23 /*  Error from xen inotify layer */
    };

### Enum virErrorLevel

    enum virErrorLevel {
        VIR_ERR_NONE = 0
        VIR_ERR_WARNING = 1 /* A simple warning */
        VIR_ERR_ERROR = 2 /*  An error */
    };

### Enum virErrorNumber

    enum virErrorNumber {
        VIR_ERR_OK = 0
        VIR_ERR_INTERNAL_ERROR = 1 /* internal error */
        VIR_ERR_NO_MEMORY = 2 /* memory allocation failure */
        VIR_ERR_NO_SUPPORT = 3 /* no support for this function */
        VIR_ERR_UNKNOWN_HOST = 4 /* could not resolve hostname */
        VIR_ERR_NO_CONNECT = 5 /* can't connect to hypervisor */
        VIR_ERR_INVALID_CONN = 6 /* invalid connection object */
        VIR_ERR_INVALID_DOMAIN = 7 /* invalid domain object */
        VIR_ERR_INVALID_ARG = 8 /* invalid function argument */
        VIR_ERR_OPERATION_FAILED = 9 /* a command to hypervisor failed */
        VIR_ERR_GET_FAILED = 10 /* a HTTP GET command to failed */
        VIR_ERR_POST_FAILED = 11 /* a HTTP POST command to failed */
        VIR_ERR_HTTP_ERROR = 12 /* unexpected HTTP error code */
        VIR_ERR_SEXPR_SERIAL = 13 /* failure to serialize an S-Expr */
        VIR_ERR_NO_XEN = 14 /* could not open Xen hypervisor control */
        VIR_ERR_XEN_CALL = 15 /* failure doing an hypervisor call */
        VIR_ERR_OS_TYPE = 16 /* unknown OS type */
        VIR_ERR_NO_KERNEL = 17 /* missing kernel information */
        VIR_ERR_NO_ROOT = 18 /* missing root device information */
        VIR_ERR_NO_SOURCE = 19 /* missing source device information */
        VIR_ERR_NO_TARGET = 20 /* missing target device information */
        VIR_ERR_NO_NAME = 21 /* missing domain name information */
        VIR_ERR_NO_OS = 22 /* missing domain OS information */
        VIR_ERR_NO_DEVICE = 23 /* missing domain devices information */
        VIR_ERR_NO_XENSTORE = 24 /* could not open Xen Store control */
        VIR_ERR_DRIVER_FULL = 25 /* too many drivers registered */
        VIR_ERR_CALL_FAILED = 26 /* not supported by the drivers (DEPRECATED) */
        VIR_ERR_XML_ERROR = 27 /* an XML description is not well formed or broken */
        VIR_ERR_DOM_EXIST = 28 /* the domain already exist */
        VIR_ERR_OPERATION_DENIED = 29 /* operation forbidden on read-only connections */
        VIR_ERR_OPEN_FAILED = 30 /* failed to open a conf file */
        VIR_ERR_READ_FAILED = 31 /* failed to read a conf file */
        VIR_ERR_PARSE_FAILED = 32 /* failed to parse a conf file */
        VIR_ERR_CONF_SYNTAX = 33 /* failed to parse the syntax of a conf file */
        VIR_ERR_WRITE_FAILED = 34 /* failed to write a conf file */
        VIR_ERR_XML_DETAIL = 35 /* detail of an XML error */
        VIR_ERR_INVALID_NETWORK = 36 /* invalid network object */
        VIR_ERR_NETWORK_EXIST = 37 /* the network already exist */
        VIR_ERR_SYSTEM_ERROR = 38 /* general system call failure */
        VIR_ERR_RPC = 39 /* some sort of RPC error */
        VIR_ERR_GNUTLS_ERROR = 40 /* error from a GNUTLS call */
        VIR_WAR_NO_NETWORK = 41 /* failed to start network */
        VIR_ERR_NO_DOMAIN = 42 /* domain not found or unexpectedly disappeared */
        VIR_ERR_NO_NETWORK = 43 /* network not found */
        VIR_ERR_INVALID_MAC = 44 /* invalid MAC address */
        VIR_ERR_AUTH_FAILED = 45 /* authentication failed */
        VIR_ERR_INVALID_STORAGE_POOL = 46 /* invalid storage pool object */
        VIR_ERR_INVALID_STORAGE_VOL = 47 /* invalid storage vol object */
        VIR_WAR_NO_STORAGE = 48 /* failed to start storage */
        VIR_ERR_NO_STORAGE_POOL = 49 /* storage pool not found */
        VIR_ERR_NO_STORAGE_VOL = 50 /* storage pool not found */
        VIR_WAR_NO_NODE = 51 /* failed to start node driver */
        VIR_ERR_INVALID_NODE_DEVICE = 52 /* invalid node device object */
        VIR_ERR_NO_NODE_DEVICE = 53 /*  node device not found */
    };

### Typedef virErrorPtr

    virError * virErrorPtr;

### Function type virErrorFunc

    void	virErrorFunc			(void * userData,
    					 virErrorPtr error)

Signature of a function to use when there is an error raised by the library.

`userData`: | user provided data for the error callback
`error`: | the error being raised.

### virConnCopyLastError ()

    int	virConnCopyLastError		(virConnectPtr conn,
    					 virErrorPtr to)

Copy the content of the last error caught on that connection This method is not protected against access from multiple threads. In a multi-threaded application, always use the global virGetLastError() API which is backed by thread local storage. If the connection object was discovered to be invalid by an API call, then the error will be reported against the global error object. Since 0.6.0, all errors reported in the per-connection object are also duplicated in the global error object. As such an application can always use virGetLastError(). This method remains for backwards compatability. One will need to free the result with virResetError()

`conn`: | pointer to the hypervisor connection
`to`: | target to receive the copy
`Returns`: | 0 if no error was found and the error code otherwise and -1 in case of parameter error.

### virConnGetLastError ()

    virErrorPtr	virConnGetLastError	(virConnectPtr conn)

Provide a pointer to the last error caught on that connection This method is not protected against access from multiple threads. In a multi-threaded application, always use the global virGetLastError() API which is backed by thread local storage. If the connection object was discovered to be invalid by an API call, then the error will be reported against the global error object. Since 0.6.0, all errors reported in the per-connection object are also duplicated in the global error object. As such an application can always use virGetLastError(). This method remains for backwards compatability.

`conn`: | pointer to the hypervisor connection
`Returns`: | a pointer to the last error or NULL if none occurred.

### virConnResetLastError ()

    void	virConnResetLastError		(virConnectPtr conn)

The error object is kept in thread local storage, so separate threads can safely access this concurrently. Reset the last error caught on that connection

`conn`: | pointer to the hypervisor connection

### virConnSetErrorFunc ()

    void	virConnSetErrorFunc		(virConnectPtr conn,
    					 void * userData,
    					 virErrorFunc handler)

Set a connection error handling function, if @handler is NULL it will reset to default which is to pass error back to the global library handler.

`conn`: | pointer to the hypervisor connection
`userData`: | pointer to the user data provided in the handler callback
`handler`: | the function to get called in case of error or NULL

### virCopyLastError ()

    int	virCopyLastError		(virErrorPtr to)

Copy the content of the last error caught at the library level The error object is kept in thread local storage, so separate threads can safely access this concurrently. One will need to free the result with virResetError()

`to`: | target to receive the copy
`Returns`: | 0 if no error was found and the error code otherwise and -1 in case of parameter error.

### virDefaultErrorFunc ()

    void	virDefaultErrorFunc		(virErrorPtr err)

Default routine reporting an error to stderr.

`err`: | pointer to the error.

### virGetLastError ()

    virErrorPtr	virGetLastError		(void)

Provide a pointer to the last error caught at the library level The error object is kept in thread local storage, so separate threads can safely access this concurrently.

`Returns`: | a pointer to the last error or NULL if none occurred.

### virResetError ()

    void	virResetError			(virErrorPtr err)

Reset the error being pointed to

`err`: | pointer to the virError to clean up

### virResetLastError ()

    void	virResetLastError		(void)

Reset the last error caught at the library level. The error object is kept in thread local storage, so separate threads can safely access this concurrently, only resetting their own error object.

### virSetErrorFunc ()

    void	virSetErrorFunc			(void * userData,
    					 virErrorFunc handler)

Set a library global error handling function, if @handler is NULL, it will reset to default printing on stderr. The error raised there are those for which no handler at the connection level could caught.

`userData`: | pointer to the user data provided in the handler callback
`handler`: | the function to get called in case of error or NULL