xend_internal.c

/*
 * xend_internal.c: access to Xen though the Xen Daemon interface
 *
 * Copyright (C) 2005
 *
 *      Anthony Liguori <aliguori@us.ibm.com>
 *
 *  This file is subject to the terms and conditions of the GNU Lesser General
 *  Public License. See the file COPYING.LIB in the main directory of this
 *  archive for more details.
 */

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/errno.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <stdbool.h>
#include <math.h>
#include <stdarg.h>
#include <malloc.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <libxml/uri.h>

#include "libvirt.h"
#include "driver.h"
#include "internal.h"
#include "sexpr.h"
#include "xml.h"
#include "xend_internal.h"

static virDriver xenDaemonDriver = {
    "Xen",
    NULL, /* init */
    xenDaemonOpen, /* open */
    xenDaemonClose, /* close */
    NULL, /* type */
    NULL, /* version */
    NULL, /* listDomains */
    NULL, /* numOfDomains */
    NULL, /* domainCreateLinux */
    NULL, /* domainLookupByID */
    NULL, /* domainLookupByUUID */
    NULL, /* domainLookupByName */
    xenDaemonDomainSuspend, /* domainSuspend */
    xenDaemonDomainResume, /* domainResume */
    xenDaemonDomainShutdown, /* domainShutdown */
    xenDaemonDomainDestroy, /* domainDestroy */
    NULL, /* domainFree */
    NULL, /* domainGetName */
    NULL, /* domainGetID */
    NULL, /* domainGetUUID */
    NULL, /* domainGetOSType */
    NULL, /* domainGetMaxMemory */
    xenDaemonDomainSetMaxMemory, /* domainSetMaxMemory */
    xenDaemonDomainGetInfo, /* domainGetInfo */
    xenDaemonDomainSave, /* domainSave */
    xenDaemonDomainRestore /* domainRestore */
};

/**
 * xend_connection_type:
 *
 * The connection to the Xen Daemon can be done either though a normal TCP
 * socket or a local domain direct connection.
 */
enum xend_connection_type {
    XEND_DOMAIN,
    XEND_TCP,
};

/**
 * xend:
 *
 * Structure associated to a connection to a Xen daemon
 */
struct xend {
    int len;
    int type;
    struct sockaddr *addr;
    struct sockaddr_un addr_un;
    struct sockaddr_in addr_in;
};


/**
 * virXendError:
 * @conn: the connection if available
 * @error: the error noumber
 * @info: extra information string
 *
 * Handle an error at the xend daemon interface
 */
static void
virXendError(virConnectPtr conn, virErrorNumber error, const char *info)
{
    const char *errmsg;

    if (error == VIR_ERR_OK)
        return;

    errmsg = __virErrorMsg(error, info);
    __virRaiseError(conn, NULL, VIR_FROM_XEND, error, VIR_ERR_ERROR,
                    errmsg, info, NULL, 0, 0, errmsg, info);
}

/**
 * virXendErrorInt:
 * @conn: the connection if available
 * @error: the error noumber
 * @val: extra integer information
 *
 * Handle an error at the xend daemon interface
 */
static void
virXendErrorInt(virConnectPtr conn, virErrorNumber error, int val)
{
    const char *errmsg;

    if (error == VIR_ERR_OK)
        return;

    errmsg = __virErrorMsg(error, NULL);
    __virRaiseError(conn, NULL, VIR_FROM_XEND, error, VIR_ERR_ERROR,
                    errmsg, NULL, NULL, val, 0, errmsg, val);
}


#define foreach(iterator, start) \
       	for (_for_i = (start), *iterator = (start)->car; \
             _for_i->kind == SEXPR_CONS; \
             _for_i = _for_i->cdr, iterator = _for_i->car)

#define foreach_node(iterator, start, path) \
        foreach(iterator, start) \
            if (sexpr_lookup(iterator, path))

/**
 * do_connect:
 * @xend: pointer to the Xen Daemon structure
 *
 * Internal routine to (re)connect to the daemon
 *
 * Returns the socket file descriptor or -1 in case of error
 */
static int
do_connect(virConnectPtr xend)
{
    int s;
    int serrno;

    s = socket(xend->type, SOCK_STREAM, 0);
    if (s == -1) {
        virXendError(xend, VIR_ERR_INTERNAL_ERROR,
                     "failed to create a socket");
        return -1;
    }

    if (connect(s, xend->addr, xend->len) == -1) {
        virXendError(xend, VIR_ERR_NO_CONNECT, "Xen Daemon");
        serrno = errno;
        close(s);
        errno = serrno;
        s = -1;
    }

    return s;
}

/**
 * wr_sync:
 * @fd:  the file descriptor
 * @buffer: the I/O buffer
 * @size: the size of the I/O
 * @do_read: write operation if 0, read operation otherwise
 *
 * Do a synchronous read or write on the file descriptor
 *
 * Returns the number of bytes exchanged, or -1 in case of error
 */
static size_t
wr_sync(int fd, void *buffer, size_t size, int do_read)
{
    size_t offset = 0;

    while (offset < size) {
        ssize_t len;

        if (do_read) {
            len = read(fd, ((char *) buffer) + offset, size - offset);
        } else {
            len = write(fd, ((char *) buffer) + offset, size - offset);
        }

        /* recoverable error, retry  */
        if ((len == -1) && ((errno == EAGAIN) || (errno == EINTR))) {
            continue;
        }

        /* eof */
        if (len == 0) {
            break;
        }

        /* unrecoverable error */
        if (len == -1) {
            if (do_read)
                virXendError(NULL, VIR_ERR_INTERNAL_ERROR,
                             "faid to read from Xen Daemon");
            else
                virXendError(NULL, VIR_ERR_INTERNAL_ERROR,
                             "faid to read from Xen Daemon");

            return (-1);
        }

        offset += len;
    }

    return offset;
}

/**
 * sread:
 * @fd:  the file descriptor
 * @buffer: the I/O buffer
 * @size: the size of the I/O
 *
 * Internal routine to do a synchronous read
 *
 * Returns the number of bytes read, or -1 in case of error
 */
static ssize_t
sread(int fd, void *buffer, size_t size)
{
    return wr_sync(fd, buffer, size, 1);
}

/**
 * swrite:
 * @fd:  the file descriptor
 * @buffer: the I/O buffer
 * @size: the size of the I/O
 *
 * Internal routine to do a synchronous write
 *
 * Returns the number of bytes written, or -1 in case of error
 */
static ssize_t
swrite(int fd, const void *buffer, size_t size)
{
    return wr_sync(fd, (void *) buffer, size, 0);
}

/**
 * swrites:
 * @fd:  the file descriptor
 * @string: the string to write
 *
 * Internal routine to do a synchronous write of a string
 *
 * Returns the number of bytes written, or -1 in case of error
 */
static ssize_t
swrites(int fd, const char *string)
{
    return swrite(fd, string, strlen(string));
}

/**
 * sreads:
 * @fd:  the file descriptor
 * @buffer: the I/O buffer
 * @n_buffer: the size of the I/O buffer
 *
 * Internal routine to do a synchronous read of a line
 *
 * Returns the number of bytes read, or -1 in case of error
 */
static ssize_t
sreads(int fd, char *buffer, size_t n_buffer)
{
    size_t offset;

    if (n_buffer < 1)
        return (-1);

    for (offset = 0; offset < (n_buffer - 1); offset++) {
        ssize_t ret;

        ret = sread(fd, buffer + offset, 1);
        if (ret == 0)
            break;
        else if (ret == -1)
            return ret;

        if (buffer[offset] == '\n') {
            offset++;
            break;
        }
    }
    buffer[offset] = 0;

    return offset;
}

static int
istartswith(const char *haystack, const char *needle)
{
    return (strncasecmp(haystack, needle, strlen(needle)) == 0);
}

/**
 * xend_req:
 * @fd: the file descriptor
 * @content: the buffer to store the content
 * @n_content: the size of the buffer
 *
 * Read the HTTP response from a Xen Daemon request.
 *
 * Returns the HTTP return code.
 */
static int
xend_req(int fd, char *content, size_t n_content)
{
    char buffer[4096];
    int content_length = -1;
    int retcode = 0;


    while (sreads(fd, buffer, sizeof(buffer)) > 0) {
        if (strcmp(buffer, "\r\n") == 0)
            break;

        if (istartswith(buffer, "Content-Length: "))
            content_length = atoi(buffer + 16);
        else if (istartswith(buffer, "HTTP/1.1 "))
            retcode = atoi(buffer + 9);
    }

    if (content_length > -1) {
        ssize_t ret;

        if ((unsigned int) content_length > (n_content + 1))
            content_length = n_content - 1;

        ret = sread(fd, content, content_length);
        if (ret < 0)
            return -1;

        content[ret] = 0;
    } else {
        content[0] = 0;
    }

    return retcode;
}

/**
 * xend_get:
 * @xend: pointer to the Xen Daemon structure
 * @path: the path used for the HTTP request
 * @content: the buffer to store the content
 * @n_content: the size of the buffer
 *
 * Do an HTTP GET RPC with the Xen Daemon
 *
 * Returns the HTTP return code or -1 in case or error.
 */
static int
xend_get(virConnectPtr xend, const char *path,
         char *content, size_t n_content)
{
    int ret;
    int s = do_connect(xend);

    if (s == -1)
        return s;

    swrites(s, "GET ");
    swrites(s, path);
    swrites(s, " HTTP/1.1\r\n");

    swrites(s,
            "Host: localhost:8000\r\n"
            "Accept-Encoding: identity\r\n"
            "Content-Type: application/x-www-form-urlencoded\r\n" "\r\n");

    ret = xend_req(s, content, n_content);
    close(s);

    if ((ret < 0) || (ret >= 300)) {
        virXendError(NULL, VIR_ERR_GET_FAILED, content);
    }

    return ret;
}

/**
 * xend_post:
 * @xend: pointer to the Xen Daemon structure
 * @path: the path used for the HTTP request
 * @ops: the informations sent for the POST
 * @content: the buffer to store the content
 * @n_content: the size of the buffer
 *
 * Do an HTTP POST RPC with the Xen Daemon, this usually makes changes at the
 * Xen level.
 *
 * Returns the HTTP return code or -1 in case or error.
 */
static int
xend_post(virConnectPtr xend, const char *path, const char *ops,
          char *content, size_t n_content)
{
    char buffer[100];
    int ret;
    int s = do_connect(xend);

    if (s == -1)
        return s;

    swrites(s, "POST ");
    swrites(s, path);
    swrites(s, " HTTP/1.1\r\n");

    swrites(s,
            "Host: localhost:8000\r\n"
            "Accept-Encoding: identity\r\n"
            "Content-Type: application/x-www-form-urlencoded\r\n"
            "Content-Length: ");
    snprintf(buffer, sizeof(buffer), "%d", strlen(ops));
    swrites(s, buffer);
    swrites(s, "\r\n\r\n");
    swrites(s, ops);

    ret = xend_req(s, content, n_content);
    close(s);

    if ((ret < 0) || (ret >= 300)) {
        virXendError(NULL, VIR_ERR_POST_FAILED, content);
    }

    return ret;
}

/**
 * http2unix:
 * @ret: the http return code
 *
 * Convert the HTTP return code to 0/-1 and set errno if needed
 *
 * Return -1 in case of error code 0 otherwise
 */
static int
http2unix(int ret)
{
    switch (ret) {
        case -1:
            break;
        case 200:
        case 201:
        case 202:
            return 0;
        case 404:
            errno = ESRCH;
            break;
        default:
            virXendErrorInt(NULL, VIR_ERR_HTTP_ERROR, ret);
            errno = EINVAL;
            break;
    }
    return -1;
}

/**
 * xend_op_ext2:
 * @xend: pointer to the Xen Daemon structure
 * @path: path for the object
 * @error: buffer for the error output
 * @n_error: size of @error
 * @key: the key for the operation
 * @ap: input values to pass to the operation
 *
 * internal routine to run a POST RPC operation to the Xen Daemon
 *
 * Returns 0 in case of success, -1 in case of failure.
 */
static int
xend_op_ext2(virConnectPtr xend, const char *path, char *error,
             size_t n_error, const char *key, va_list ap)
{
    char ops[1024];
    const char *k = key, *v;
    int offset = 0;

    while (k) {
        v = va_arg(ap, const char *);

        offset += snprintf(ops + offset, sizeof(ops) - offset, "%s", k);
        offset += snprintf(ops + offset, sizeof(ops) - offset, "%s", "=");
        offset += snprintf(ops + offset, sizeof(ops) - offset, "%s", v);
        k = va_arg(ap, const char *);

        if (k)
            offset += snprintf(ops + offset,
                               sizeof(ops) - offset, "%s", "&");
    }

    return http2unix(xend_post(xend, path, ops, error, n_error));
}

/**
 * xend_node_op:
 * @xend: pointer to the Xen Daemon structure
 * @path: path for the object
 * @key: the key for the operation
 * @...: input values to pass to the operation
 *
 * internal routine to run a POST RPC operation to the Xen Daemon
 *
 * Returns 0 in case of success, -1 in case of failure.
 */
static int
xend_node_op(virConnectPtr xend, const char *path, const char *key, ...)
{
    va_list ap;
    int ret;
    char error[1024];

    va_start(ap, key);
    ret = xend_op_ext2(xend, path, error, sizeof(error), key, ap);
    va_end(ap);

    return ret;
}

/**
 * xend_node_op:
 * @xend: pointer to the Xen Daemon structure
 * @name: the domain name target of this operation
 * @error: buffer for the error output
 * @n_error: size of @error
 * @key: the key for the operation
 * @ap: input values to pass to the operation
 * @...: input values to pass to the operation
 *
 * internal routine to run a POST RPC operation to the Xen Daemon targetting
 * a given domain.
 *
 * Returns 0 in case of success, -1 in case of failure.
 */
static int
xend_op_ext(virConnectPtr xend, const char *name, char *error,
            size_t n_error, const char *key, ...)
{
    char buffer[1024];
    va_list ap;
    int ret;

    snprintf(buffer, sizeof(buffer), "/xend/domain/%s", name);

    va_start(ap, key);
    ret = xend_op_ext2(xend, buffer, error, n_error, key, ap);
    va_end(ap);

    return ret;
}

#define xend_op(xend, name, key, ...) ({char error[1024]; xend_op_ext(xend, name, error, sizeof(error), key, __VA_ARGS__);})

/**
 * sexpr_get:
 * @xend: pointer to the Xen Daemon structure
 * @fmt: format string for the path of the operation
 * @...: extra data to build the path of the operation
 *
 * Internal routine to run a simple GET RPC operation to the Xen Daemon
 *
 * Returns a parsed S-Expression in case of success, NULL in case of failure
 */
static struct sexpr *
sexpr_get(virConnectPtr xend, const char *fmt, ...)
{
    char buffer[4096];
    char path[1024];
    va_list ap;
    int ret;

    va_start(ap, fmt);
    vsnprintf(path, sizeof(path), fmt, ap);
    va_end(ap);

    ret = xend_get(xend, path, buffer, sizeof(buffer));
    ret = http2unix(ret);
    if (ret == -1)
        return NULL;

    return string2sexpr(buffer);
}

/**
 * sexpr_int:
 * @sexpr: an S-Expression
 * @name: the name for the value
 *
 * convenience function to lookup an int value in the S-Expression
 *
 * Returns the value found or 0 if not found (but may not be an error)
 */
static int
sexpr_int(struct sexpr *sexpr, const char *name)
{
    const char *value = sexpr_node(sexpr, name);

    if (value) {
        return strtol(value, NULL, 0);
    }
    return 0;
}

/**
 * sexpr_float:
 * @sexpr: an S-Expression
 * @name: the name for the value
 *
 * convenience function to lookup a float value in the S-Expression
 *
 * Returns the value found or 0 if not found (but may not be an error)
 */
static double
sexpr_float(struct sexpr *sexpr, const char *name)
{
    const char *value = sexpr_node(sexpr, name);

    if (value) {
        return strtod(value, NULL);
    }
    return 0;
}

/**
 * sexpr_u64:
 * @sexpr: an S-Expression
 * @name: the name for the value
 *
 * convenience function to lookup a 64bits unsigned int value in the
 * S-Expression
 *
 * Returns the value found or 0 if not found (but may not be an error)
 */
static uint64_t
sexpr_u64(struct sexpr *sexpr, const char *name)
{
    const char *value = sexpr_node(sexpr, name);

    if (value) {
        return strtoll(value, NULL, 0);
    }
    return 0;
}

static int
sexpr_strlen(struct sexpr *sexpr, const char *path)
{
    const char *r = sexpr_node(sexpr, path);

    return r ? (strlen(r) + 1) : 0;
}

static const char *
sexpr_strcpy(char **ptr, struct sexpr *node, const char *path)
{
    const char *ret = sexpr_node(node, path);

    if (ret) {
        strcpy(*ptr, ret);
        ret = *ptr;
        *ptr += (strlen(ret) + 1);
    }
    return ret;
}


/**
 * sexpr_node_system:
 * @sexpr: an S-Expression
 * @name: the name for the value
 *
 * convenience function to lookup a value describing the kind of system
 * from the S-Expression
 *
 * Returns the value found or 0 if not found (but may not be an error)
 */
static enum xend_node_system
sexpr_node_system(struct sexpr *node, const char *path)
{
    const char *syst = sexpr_node(node, path);

    if (syst) {
        if (strcmp(syst, "Linux") == 0) {
            return XEND_SYSTEM_LINUX;
        }
    }

    return XEND_DEFAULT;
}

/**
 * sexpr_uuid:
 * @ptr: where to store the UUID, incremented
 * @sexpr: an S-Expression
 * @name: the name for the value
 *
 * convenience function to lookup an UUID value from the S-Expression
 *
 * Returns a pointer to the stored UUID or NULL in case of error.
 */
static unsigned char *
sexpr_uuid(char **ptr, struct sexpr *node, const char *path)
{
    const char *r = sexpr_node(node, path);
    int uuid[16];
    unsigned char *dst_uuid = NULL;
    int ret;
    int i;

    memset(uuid, 0xFF, sizeof(uuid));

    if (r == NULL)
        goto error;

    ret = sscanf(r,
                 "%02x%02x%02x%02x-"
                 "%02x%02x-"
                 "%02x%02x-"
                 "%02x%02x-"
                 "%02x%02x%02x%02x%02x%02x",
                 uuid + 0, uuid + 1, uuid + 2, uuid + 3,
                 uuid + 4, uuid + 5, uuid + 6, uuid + 7,
                 uuid + 8, uuid + 9, uuid + 10, uuid + 11,
                 uuid + 12, uuid + 13, uuid + 14, uuid + 15);
    if (ret == 16)
        goto done;

    ret = sscanf(r,
                 "%02x%02x%02x%02x-"
                 "%02x%02x%02x%02x-"
                 "%02x%02x%02x%02x-"
                 "%02x%02x%02x%02x",
                 uuid + 0, uuid + 1, uuid + 2, uuid + 3,
                 uuid + 4, uuid + 5, uuid + 6, uuid + 7,
                 uuid + 8, uuid + 9, uuid + 10, uuid + 11,
                 uuid + 12, uuid + 13, uuid + 14, uuid + 15);
    if (ret != 16)
        goto error;

  done:
    dst_uuid = (unsigned char *) *ptr;
    *ptr += 16;

    for (i = 0; i < 16; i++)
        dst_uuid[i] = uuid[i] & 0xFF;

  error:
    return dst_uuid;
}


/**
 * urlencode:
 * @string: the input URL
 *
 * Encode an URL see RFC 2396 and following
 *
 * Returns the new string or NULL in case of error.
 */
static char *
urlencode(const char *string)
{
    size_t len = strlen(string);
    char *buffer = malloc(len * 3 + 1);
    char *ptr = buffer;
    size_t i;

    if (buffer == NULL)
        return (NULL);
    for (i = 0; i < len; i++) {
        switch (string[i]) {
            case ' ':
            case '\n':
                sprintf(ptr, "%%%02x", string[i]);
                ptr += 3;
                break;
            default:
                *ptr = string[i];
                ptr++;
        }
    }

    *ptr = 0;

    return buffer;
}

/* PUBLIC FUNCTIONS */

/**
 * xenDaemonOpen_unix:
 * @conn: an existing virtual connection block
 * @path: the path for the Xen Daemon socket
 *
 * Creates a localhost Xen Daemon connection
 * Note: this doesn't try to check if the connection actually works
 *
 * Returns 0 in case of success, -1 in case of error.
 */
int
xenDaemonOpen_unix(virConnectPtr xend, const char *path)
{
    struct sockaddr_un *addr;

    if ((xend == NULL) || (path == NULL))
        return (-1);

    addr = &xend->addr_un;
    addr->sun_family = AF_UNIX;
    memset(addr->sun_path, 0, sizeof(addr->sun_path));
    strncpy(addr->sun_path, path, sizeof(addr->sun_path));

    xend->len = sizeof(addr->sun_family) + strlen(addr->sun_path);
    if ((unsigned int) xend->len > sizeof(addr->sun_path))
        xend->len = sizeof(addr->sun_path);

    xend->addr = (struct sockaddr *) addr;
    xend->type = PF_UNIX;

    return (0);
}

/**
 * xenDaemonOpen_tcp:
 * @conn: an existing virtual connection block
 * @host: the host name for the Xen Daemon
 * @port: the port 
 *
 * Creates a possibly remote Xen Daemon connection
 * Note: this doesn't try to check if the connection actually works
 *
 * Returns 0 in case of success, -1 in case of error.
 */
int
xenDaemonOpen_tcp(virConnectPtr xend, const char *host, int port)
{
    struct in_addr ip;
    struct hostent *pent;

    if ((xend == NULL) || (host == NULL) || (port <= 0))
        return (-1);

    pent = gethostbyname(host);
    if (pent == NULL) {
        if (inet_aton(host, &ip) == 0) {
            virXendError(xend, VIR_ERR_UNKNOWN_HOST, host);
            errno = ESRCH;
            return (-1);
        }
    } else {
        memcpy(&ip, pent->h_addr_list[0], sizeof(ip));
    }

    xend->len = sizeof(struct sockaddr_in);
    xend->addr = (struct sockaddr *) &xend->addr_in;
    xend->type = PF_INET;

    xend->addr_in.sin_family = AF_INET;
    xend->addr_in.sin_port = htons(port);
    memcpy(&xend->addr_in.sin_addr, &ip, sizeof(ip));

    return (0);
}

/**
 * xend_wait_for_devices:
 * @xend: pointer to the Xem Daemon block
 * @name: name for the domain
 *
 * Block the domain until all the virtual devices are ready. This operation
 * is needed when creating a domain before resuming it.
 *
 * Returns 0 in case of success, -1 (with errno) in case of error.
 */
int
xend_wait_for_devices(virConnectPtr xend, const char *name)
{
    return xend_op(xend, name, "op", "wait_for_devices", NULL);
}

/**
 * xend_rename:
 * @xend: pointer to the Xem Daemon block
 * @old: old name for the domain
 * @new: new name for the domain
 *
 * Rename the domain
 *
 * Returns 0 in case of success, -1 (with errno) in case of error.
 */
int
xend_rename(virConnectPtr xend, const char *old, const char *new)
{
    if ((xend == NULL) || (old == NULL) || (new == NULL)) {
        /* this should be caught at the interface but ... */
        virXendError(xend, VIR_ERR_INVALID_ARG, __FUNCTION__);
        return (-1);
    }
    return xend_op(xend, old, "op", "rename", "name", new, NULL);
}

/**
 * xend_reboot:
 * @xend: pointer to the Xem Daemon block
 * @name: name for the domain
 *
 * Reboot the domain, the OS is properly shutdown and restarted
 *
 * Returns 0 in case of success, -1 (with errno) in case of error.
 */
int
xend_reboot(virConnectPtr xend, const char *name)
{
    if ((xend == NULL) || (name == NULL)) {
        /* this should be caught at the interface but ... */
        virXendError(xend, VIR_ERR_INVALID_ARG, __FUNCTION__);
        return (-1);
    }
    return xend_op(xend, name, "op", "shutdown", "reason", "reboot", NULL);
}

/**
 * xend_sysrq:
 * @xend: pointer to the Xem Daemon block
 * @name: name for the domain
 * @key: the SysReq key
 *
 * Send a SysReq key which is used to debug Linux kernels running in the domain
 *
 * Returns 0 in case of success, -1 (with errno) in case of error.
 */
int
xend_sysrq(virConnectPtr xend, const char *name, const char *key)
{
    if ((xend == NULL) || (name == NULL) || (key == NULL)) {
        /* this should be caught at the interface but ... */
        virXendError(xend, VIR_ERR_INVALID_ARG, __FUNCTION__);
        return (-1);
    }
    return xend_op(xend, name, "op", "sysrq", "key", key, NULL);
}

/**
 * xenDaemonListDomains:
 * @xend: pointer to the Xem Daemon block
 *
 * This method will return an array of names of currently running
 * domains.  The memory should be released will a call to free().
 *
 * Returns a list of names or NULL in case of error.
 */
char **
xenDaemonListDomains(virConnectPtr xend)
{
    size_t extra = 0;
    struct sexpr *root = NULL;
    char **ret = NULL;
    int count = 0;
    int i;
    char *ptr;
    struct sexpr *_for_i, *node;

    root = sexpr_get(xend, "/xend/domain");
    if (root == NULL)
        goto error;

    for (_for_i = root, node = root->car; _for_i->kind == SEXPR_CONS;
         _for_i = _for_i->cdr, node = _for_i->car) {
        if (node->kind != SEXPR_VALUE)
            continue;
        extra += strlen(node->value) + 1;
        count++;
    }

    ptr = malloc((count + 1) * sizeof(char *) + extra);
    if (ptr == NULL)
        goto error;

    ret = (char **) ptr;
    ptr += sizeof(char *) * (count + 1);

    i = 0;
    for (_for_i = root, node = root->car; _for_i->kind == SEXPR_CONS;
         _for_i = _for_i->cdr, node = _for_i->car) {
        if (node->kind != SEXPR_VALUE)
            continue;
        ret[i] = ptr;
        strcpy(ptr, node->value);
        ptr += strlen(node->value) + 1;
        i++;
    }

    ret[i] = NULL;

  error:
    sexpr_free(root);
    return ret;
}

/**
 * xenDaemonDomainCreateLinux:
 * @xend: A xend instance
 * @sexpr: An S-Expr description of the domain.
 *
 * This method will create a domain based the passed in description.  The
 * domain will be paused after creation and must be unpaused with
 * xenDaemonResumeDomain() to begin execution.
 * This method may be deprecated once switching to XML-RPC based communcations
 * with xend.
 *
 * Returns 0 for success, -1 (with errno) on error
 */

int
xenDaemonDomainCreateLinux(virConnectPtr xend, const char *sexpr)
{
    int ret, serrno;
    char *ptr;

    ptr = urlencode(sexpr);
    if (ptr == NULL) {
        /* this should be caught at the interface but ... */
        virXendError(xend, VIR_ERR_INTERNAL_ERROR,
                     "Failed to urlencode the create S-Expr");
        return (-1);
    }

    ret = xend_op(xend, "", "op", "create", "config", ptr, NULL);

    serrno = errno;
    free(ptr);
    errno = serrno;

    return ret;
}

/**
 * xend_set_memory:
 * @xend: A xend instance
 * @name: The name of the domain
 * @value: The desired allocation in bytes
 *
 * This method will set a target memory allocation for a given domain and
 * request that the guest meet this target.  The guest may or may not actually
 * achieve this target.  When this function returns, it does not signify that
 * the domain has actually reached that target.
 *
 * Memory for a domain can only be allocated up to the maximum memory setting.
 * There is no safe guard for allocations that are too small so be careful
 * when using this function to reduce a domain's memory usage.
 *
 * Returns 0 for success; -1 (with errno) on error
 */
int
xend_set_memory(virConnectPtr xend, const char *name, uint64_t value)
{
    char buf[1024];

    snprintf(buf, sizeof(buf), "%llu", value >> 20);
    return xend_op(xend, name, "op", "mem_target_set", "target", buf,
                   NULL);
}


/**
 * xenDaemonDomainLookupByName_ids:
 * @xend: A xend instance
 * @domname: The name of the domain
 * @uuid: return value for the UUID if not NULL
 *
 * This method looks up the id of a domain
 *
 * Returns the id on success; -1 (with errno) on error
 */
int
xenDaemonDomainLookupByName_ids(virConnectPtr xend, const char *domname,
                    unsigned char *uuid)
{
    struct sexpr *root;
    const char *value;
    int ret = -1;

    if (uuid != NULL)
        memset(uuid, 0, 16);
    root = sexpr_get(xend, "/xend/domain/%s?detail=1", domname);
    if (root == NULL)
        goto error;

    value = sexpr_node(root, "domain/domid");
    if (value == NULL) {
        virXendError(xend, VIR_ERR_INTERNAL_ERROR,
                     "domain informations incomplete, missing domid");
        goto error;
    }
    ret = strtol(value, NULL, 0);
    if ((ret == 0) && (value[0] != '0')) {
        virXendError(xend, VIR_ERR_INTERNAL_ERROR,
                     "domain informations incorrect domid not numberic");
        ret = -1;
    } else if (uuid != NULL) {
        char **ptr = (char **) &uuid;

        if (sexpr_uuid(ptr, root, "domain/uuid") == NULL) {
            virXendError(xend, VIR_ERR_INTERNAL_ERROR,
                         "domain informations incomplete, missing uuid");
        }
    }

  error:
    sexpr_free(root);
    return (ret);
}

/**
 * xend_get_node:
 * @xend: A xend instance
 *
 * This method returns information about the physical host
 * machine running Xen.
 *
 * Returns node info on success; NULL (with errno) on error
 */
struct xend_node *
xend_get_node(virConnectPtr xend)
{
    struct sexpr *root;
    struct xend_node *node = NULL;
    size_t size;
    char *ptr;

    root = sexpr_get(xend, "/xend/node/");
    if (root == NULL)
        goto error;

    size = sizeof(struct xend_node);
    size += sexpr_strlen(root, "node/host");
    size += sexpr_strlen(root, "node/release");
    size += sexpr_strlen(root, "node/version");
    size += sexpr_strlen(root, "node/machine");
    size += sexpr_strlen(root, "node/hw_caps");
    size += sexpr_strlen(root, "node/xen_caps");
    size += sexpr_strlen(root, "node/platform_params");
    size += sexpr_strlen(root, "node/xen_changeset");
    size += sexpr_strlen(root, "node/cc_compiler");
    size += sexpr_strlen(root, "node/cc_compile_by");
    size += sexpr_strlen(root, "node/cc_compile_domain");
    size += sexpr_strlen(root, "node/cc_compile_date");

    ptr = malloc(size);
    if (ptr == NULL)
        goto error;

    node = (struct xend_node *) ptr;
    ptr += sizeof(struct xend_node);

    node->system = sexpr_node_system(root, "node/system");
    node->host = sexpr_strcpy(&ptr, root, "node/host");
    node->release = sexpr_strcpy(&ptr, root, "node/release");
    node->version = sexpr_strcpy(&ptr, root, "node/version");
    node->machine = sexpr_strcpy(&ptr, root, "node/machine");
    node->nr_cpus = sexpr_int(root, "node/nr_cpus");
    node->nr_nodes = sexpr_int(root, "node/nr_nodes");
    node->sockets_per_node = sexpr_int(root, "node/sockets_per_node");
    node->cores_per_socket = sexpr_int(root, "node/cores_per_socket");
    node->threads_per_core = sexpr_int(root, "node/threads_per_core");
    node->cpu_mhz = sexpr_int(root, "node/cpu_mhz");
    node->hw_caps = sexpr_strcpy(&ptr, root, "node/hw_caps");
    node->total_memory = sexpr_u64(root, "node/total_memory") << 12;
    node->free_memory = sexpr_u64(root, "node/free_memory") << 12;
    node->xen_major = sexpr_int(root, "node/xen_major");
    node->xen_minor = sexpr_int(root, "node/xen_minor");
    {
        const char *tmp;

        tmp = sexpr_node(root, "node/xen_extra");
        if (tmp) {
            if (*tmp == '.')
                tmp++;
            node->xen_extra = atoi(tmp);
        } else {
            node->xen_extra = 0;
        }
    }
    node->xen_caps = sexpr_strcpy(&ptr, root, "node/xen_caps");
    node->platform_params =
        sexpr_strcpy(&ptr, root, "node/platform_params");
    node->xen_changeset = sexpr_strcpy(&ptr, root, "node/xen_changeset");
    node->cc_compiler = sexpr_strcpy(&ptr, root, "node/cc_compiler");
    node->cc_compile_by = sexpr_strcpy(&ptr, root, "node/cc_compile_by");
    node->cc_compile_domain =
        sexpr_strcpy(&ptr, root, "node/cc_compile_domain");
    node->cc_compile_date =
        sexpr_strcpy(&ptr, root, "node/cc_compile_date");

  error:
    sexpr_free(root);
    return node;
}

/**
 * xend_node_shutdown:
 * @xend: A xend instance
 *
 * This method shuts down the physical machine running Xen.
 *
 * Returns 0 on success; -1 (with errno) on error
 */
int
xend_node_shutdown(virConnectPtr xend)
{
    return xend_node_op(xend, "/xend/node/", "op", "halt", NULL);
}

/**
 * xend_node_restart:
 * @xend: A xend instance
 *
 * This method restarts the physical machine running Xen.
 *
 * Returns 0 on success; -1 (with errno) on error
 */
int
xend_node_restart(virConnectPtr xend)
{
    return xend_node_op(xend, "/xend/node/", "op", "restart", NULL);
}

/**
 * xend_dmesg:
 * @xend: A xend instance
 * @buffer: A buffer to hold the messages
 * @n_buffer: Size of buffer (including null terminator)
 *
 * This function will place the debugging messages from the
 * hypervisor into a buffer with a null terminator.
 *
 * Returns 0 on success; -1 (with errno) on error
 */
int
xend_dmesg(virConnectPtr xend, char *buffer, size_t n_buffer)
{
    return http2unix(xend_get(xend, "/xend/node/dmesg", buffer, n_buffer));
}

/**
 * xend_dmesg_clear:
 * @xend: A xend instance
 *
 * This function will clear the debugging message ring queue
 * in the hypervisor.
 *
 * Returns 0 on success; -1 (with errno) on error
 */
int
xend_dmesg_clear(virConnectPtr xend)
{
    return xend_node_op(xend, "/xend/node/dmesg", "op", "clear", NULL);
}

/**
 * xend_log:
 * @xend: A xend instance
 * @buffer: The buffer to hold the messages
 * @n_buffer: Size of buffer (including null terminator)
 *
 * This function will place the Xend debugging messages into
 * a buffer with a null terminator.
 *
 * Returns 0 on success; -1 (with errno) on error
 */
int
xend_log(virConnectPtr xend, char *buffer, size_t n_buffer)
{
    return http2unix(xend_get(xend, "/xend/node/log", buffer, n_buffer));
}

/*****************************************************************
 ******
 ******
 ******
 ******
             Needed helper code
 ******
 ******
 ******
 ******
 *****************************************************************/
/**
 * xend_parse_sexp_desc:
 * @root: the root of the parsed S-Expression
 * @name: output name of the domain
 *
 * Parse the xend sexp description and turn it into the XML format similar
 * to the one unsed for creation.
 *
 * Returns the 0 terminated XML string or NULL in case of error.
 *         the caller must free() the returned value.
 */
static char *
xend_parse_sexp_desc(struct sexpr *root)
{
    char *ret;
    struct sexpr *cur, *node;
    const char *tmp;
    virBuffer buf;

    if (root == NULL) {
        /* ERROR */
        return (NULL);
    }
    ret = malloc(1000);
    if (ret == NULL)
        return (NULL);
    buf.content = ret;
    buf.size = 1000;
    buf.use = 0;

    virBufferVSprintf(&buf, "<domain type='xen' id='%d'>\n",
                      sexpr_int(root, "domain/domid"));
    tmp = sexpr_node(root, "domain/name");
    if (tmp == NULL) {
        virXendError(NULL, VIR_ERR_INTERNAL_ERROR,
                     "domain informations incomplete, missing name");
        goto error;
    }
    virBufferVSprintf(&buf, "  <name>%s</name>\n", tmp);
    tmp = sexpr_node(root, "domain/image/linux/kernel");
    if (tmp == NULL) {
        /*
         * TODO: we will need some fallback here for other guest OSes
         */
        virXendError(NULL, VIR_ERR_INTERNAL_ERROR,
                     "domain informations incomplete, missing kernel");
        goto error;
    }
    virBufferAdd(&buf, "  <os>\n", 7);
    virBufferVSprintf(&buf, "    <type>linux</type>\n");
    virBufferVSprintf(&buf, "    <kernel>%s</kernel>\n", tmp);
    tmp = sexpr_node(root, "domain/image/linux/ramdisk");
    if ((tmp != NULL) && (tmp[0] != 0))
        virBufferVSprintf(&buf, "    <initrd>%s</initrd>\n", tmp);
    tmp = sexpr_node(root, "domain/image/linux/root");
    if ((tmp != NULL) && (tmp[0] != 0))
        virBufferVSprintf(&buf, "    <root>%s</root>\n", tmp);
    tmp = sexpr_node(root, "domain/image/linux/args");
    if ((tmp != NULL) && (tmp[0] != 0))
        virBufferVSprintf(&buf, "    <cmdline>%s</cmdline>\n", tmp);
    virBufferAdd(&buf, "  </os>\n", 8);
    virBufferVSprintf(&buf, "  <memory>%d</memory>\n",
                      (int) (sexpr_u64(root, "domain/maxmem") << 10));
    virBufferVSprintf(&buf, "  <vcpu>%d</vcpu>\n",
                      sexpr_int(root, "domain/vcpus"));
    virBufferAdd(&buf, "  <devices>\n", 12);
    for (cur = root; cur->kind == SEXPR_CONS; cur = cur->cdr) {
        node = cur->car;
        if (sexpr_lookup(node, "device/vbd")) {
            tmp = sexpr_node(node, "device/vbd/uname");
            if (tmp == NULL)
                continue;
            if (!memcmp(tmp, "file:", 5)) {
                tmp += 5;
                virBufferVSprintf(&buf, "    <disk type='file'>\n");
                virBufferVSprintf(&buf, "      <source file='%s'/>\n",
                                  tmp);
                tmp = sexpr_node(node, "device/vbd/dev");
                if (tmp == NULL) {
                    virXendError(NULL, VIR_ERR_INTERNAL_ERROR,
                                 "domain informations incomplete, vbd has no dev");
                    goto error;
                }
                virBufferVSprintf(&buf, "      <target dev='%s'/>\n", tmp);
                tmp = sexpr_node(node, "device/vbd/mode");
                if ((tmp != NULL) && (!strcmp(tmp, "r")))
                    virBufferVSprintf(&buf, "      <readonly/>\n");
                virBufferAdd(&buf, "    </disk>\n", 12);
            } else if (!memcmp(tmp, "phy:", 4)) {
                tmp += 4;
                virBufferVSprintf(&buf, "    <disk type='block'>\n");
                virBufferVSprintf(&buf, "      <source dev='%s'/>\n", tmp);
                tmp = sexpr_node(node, "device/vbd/dev");
                if (tmp == NULL) {
                    virXendError(NULL, VIR_ERR_INTERNAL_ERROR,
                                 "domain informations incomplete, vbd has no dev");
                    goto error;
                }
                virBufferVSprintf(&buf, "      <target dev='%s'/>\n", tmp);
                tmp = sexpr_node(node, "device/vbd/mode");
                if ((tmp != NULL) && (!strcmp(tmp, "r")))
                    virBufferVSprintf(&buf, "      <readonly/>\n");
                virBufferAdd(&buf, "    </disk>\n", 12);
            } else {
                char serial[1000];

                TODO sexpr2string(node, serial, 1000);
                virBufferVSprintf(&buf, "<!-- Failed to parse %s -->\n",
                                  serial);
            TODO}
        } else if (sexpr_lookup(node, "device/vif")) {
            tmp = sexpr_node(node, "device/vif/bridge");
            if (tmp != NULL) {
                virBufferVSprintf(&buf, "    <interface type='bridge'>\n");
                virBufferVSprintf(&buf, "      <source bridge='%s'/>\n",
                                  tmp);
                tmp = sexpr_node(node, "device/vif/vifname");
                if (tmp != NULL)
                    virBufferVSprintf(&buf, "      <target dev='%s'/>\n",
                                      tmp);
                tmp = sexpr_node(node, "device/vif/mac");
                if (tmp != NULL)
                    virBufferVSprintf(&buf, "      <mac address='%s'/>\n",
                                      tmp);
                tmp = sexpr_node(node, "device/vif/ip");
                if (tmp != NULL)
                    virBufferVSprintf(&buf, "      <ip address='%s'/>\n",
                                      tmp);
                tmp = sexpr_node(node, "device/vif/script");
                if (tmp != NULL)
                    virBufferVSprintf(&buf, "      <script path='%s'/>\n",
                                      tmp);
                virBufferAdd(&buf, "    </interface>\n", 17);
            } else {
                char serial[1000];

                TODO sexpr2string(node->car, serial, 1000);
                virBufferVSprintf(&buf, "<!-- Failed to parse %s -->\n",
                                  serial);
            }

        }
    }
    virBufferAdd(&buf, "  </devices>\n", 13);
    virBufferAdd(&buf, "</domain>\n", 10);

    buf.content[buf.use] = 0;
    return (ret);

  error:
    if (ret != NULL)
        free(ret);
    return (NULL);
}

/**
 * sexpr_to_xend_domain_info:
 * @root: an S-Expression describing a domain
 * @info: a info data structure to fill=up
 *
 * Internal routine filling up the info structure with the values from
 * the domain root provided.
 *
 * Returns 0 in case of success, -1 in case of error
 */
static int
sexpr_to_xend_domain_info(struct sexpr *root, virDomainInfoPtr info)
{
    const char *flags;


    if ((root == NULL) || (info == NULL))
        return (-1);

    info->memory = sexpr_u64(root, "domain/memory") << 10;
    info->maxMem = sexpr_u64(root, "domain/maxmem") << 10;
    flags = sexpr_node(root, "domain/state");

    if (flags) {
        if (strchr(flags, 'c'))
            info->state = VIR_DOMAIN_CRASHED;
        else if (strchr(flags, 's'))
            info->state = VIR_DOMAIN_SHUTDOWN;
        else if (strchr(flags, 'd'))
            info->state = VIR_DOMAIN_SHUTOFF;
        else if (strchr(flags, 'p'))
            info->state = VIR_DOMAIN_PAUSED;
        else if (strchr(flags, 'b'))
            info->state = VIR_DOMAIN_BLOCKED;
        else if (strchr(flags, 'r'))
            info->state = VIR_DOMAIN_RUNNING;
    } else {
        info->state = VIR_DOMAIN_NOSTATE;
    }
    info->cpuTime = sexpr_float(root, "domain/cpu_time") * 1000000000;
    info->nrVirtCpu = sexpr_int(root, "domain/vcpus");
    return (0);
}

/**
 * sexpr_to_domain:
 * @conn: an existing virtual connection block
 * @root: an S-Expression describing a domain
 *
 * Internal routine returning the associated virDomainPtr for this domain
 *
 * Returns the domain pointer or NULL in case of error.
 */
static virDomainPtr
sexpr_to_domain(virConnectPtr conn, struct sexpr *root)
{
    virDomainPtr ret;
    char *dst_uuid = NULL;
    const char *name;

    if ((conn == NULL) || (root == NULL))
        return(NULL);

    ret = (virDomainPtr) malloc(sizeof(virDomain));
    if (ret == NULL) {
        virXendError(conn, VIR_ERR_NO_MEMORY, "Allocating domain");
	return(NULL);
    }
    memset(ret, 0, sizeof(virDomain));
    ret->magic = VIR_DOMAIN_MAGIC;
    ret->conn = conn;
    ret->handle = sexpr_int(root, "domain/domid");
    if (ret->handle < 0)
        goto error;
    dst_uuid = (char *) &(ret->uuid[0]);
    if (sexpr_uuid(&dst_uuid, root, "domain/uuid") == NULL)
        goto error;
    name = sexpr_node(root, "domain/name");
    if (name == NULL)
        goto error;
    ret->name = strdup(name);
    if (ret->name == NULL)
        goto error;

    return (ret);
error:
    virXendError(conn, VIR_ERR_INTERNAL_ERROR,
                 "failed to parse Xend domain informations");
    if (ret->name != NULL)
        free(ret->name );
    free(ret);
    return(NULL);
}


/*****************************************************************
 ******
 ******
 ******
 ******
             Refactored
 ******
 ******
 ******
 ******
 *****************************************************************/
/**
 * xenDaemonOpen:
 * @conn: an existing virtual connection block
 * @name: optional argument to select a connection type
 * @flags: combination of virDrvOpenFlag(s)
 *
 * Creates a localhost Xen Daemon connection
 * Note: this doesn't try to check if the connection actually works
 *
 * Returns 0 in case of success, -1 in case of error.
 */
int
xenDaemonOpen(virConnectPtr conn, const char *name, int flags)
{
    xmlURIPtr uri;
    int ret;

    if (name == NULL) {
        name = "http://localhost:8000/";
    }
    uri = xmlParseURI(name);
    if (uri == NULL) {
	if (!(flags & VIR_DRV_OPEN_QUIET))
	    virXendError(conn, VIR_ERR_NO_SUPPORT, name);
	return(-1);
    }

    xmlFreeURI(uri);
    
    return (xenDaemonOpen_tcp(conn, "localhost", 8000));

/*    return(xenDaemonOpen_unix(conn, "/var/lib/xend/xend-socket")); */

    return(ret);
}

/**
 * xenDaemonClose:
 * @conn: an existing virtual connection block
 *
 * This method should be called when a connection to xend instance
 * initialized with xenDaemonOpen is no longer needed
 * to free the associated resources.
 *
 * Returns 0 in case of succes, -1 in case of error
 */
int
xenDaemonClose(virConnectPtr conn ATTRIBUTE_UNUSED)
{
    return(0);
}

/**
 * xenDaemonDomainSuspend:
 * @domain: pointer to the Domain block
 *
 * Pause the domain, the domain is not scheduled anymore though its resources
 * are preserved. Use xenDaemonDomainResume() to resume execution.
 *
 * Returns 0 in case of success, -1 (with errno) in case of error.
 */
int
xenDaemonDomainSuspend(virDomainPtr domain)
{
    if ((domain == NULL) || (domain->conn == NULL) || (domain->name == NULL)) {
        virXendError((domain ? domain->conn : NULL), VIR_ERR_INVALID_ARG,
	             __FUNCTION__);
        return(-1);
    }
    return xend_op(domain->conn, domain->name, "op", "pause", NULL);
}

/**
 * xenDaemonDomainResume:
 * @xend: pointer to the Xem Daemon block
 * @name: name for the domain
 *
 * Resume the domain after xenDaemonDomainSuspend() has been called
 *
 * Returns 0 in case of success, -1 (with errno) in case of error.
 */
int
xenDaemonDomainResume(virDomainPtr domain)
{
    if ((domain == NULL) || (domain->conn == NULL) || (domain->name == NULL)) {
        virXendError((domain ? domain->conn : NULL), VIR_ERR_INVALID_ARG,
	             __FUNCTION__);
        return(-1);
    }
    return xend_op(domain->conn, domain->name, "op", "unpause", NULL);
}

/**
 * xenDaemonDomainShutdown:
 * @domain: pointer to the Domain block
 *
 * Shutdown the domain, the OS is requested to properly shutdown
 * and the domain may ignore it.  It will return immediately
 * after queuing the request.
 *
 * Returns 0 in case of success, -1 (with errno) in case of error.
 */
int
xenDaemonDomainShutdown(virDomainPtr domain)
{
    if ((domain == NULL) || (domain->conn == NULL) || (domain->name == NULL)) {
        virXendError((domain ? domain->conn : NULL), VIR_ERR_INVALID_ARG,
	             __FUNCTION__);
        return(-1);
    }
    return xend_op(domain->conn, domain->name, "op", "shutdown", "reason", "halt", NULL);
}

/**
 * xenDaemonDomainDestroy:
 * @domain: pointer to the Domain block
 *
 * Abruptly halt the domain, the OS is not properly shutdown and the
 * resources allocated for the domain are immediately freed, mounted
 * filesystems will be marked as uncleanly shutdown.
 * After calling this function, the domain's status will change to
 * dying and will go away completely once all of the resources have been
 * unmapped (usually from the backend devices).
 *
 * Returns 0 in case of success, -1 (with errno) in case of error.
 */
int
xenDaemonDomainDestroy(virDomainPtr domain)
{
    if ((domain == NULL) || (domain->conn == NULL) || (domain->name == NULL)) {
        virXendError((domain ? domain->conn : NULL), VIR_ERR_INVALID_ARG,
	             __FUNCTION__);
        return(-1);
    }
    return xend_op(domain->conn, domain->name, "op", "destroy", NULL);
}

/**
 * xenDaemonDomainSave:
 * @domain: pointer to the Domain block
 * @filename: path for the output file
 *
 * This method will suspend a domain and save its memory contents to
 * a file on disk.  Use xenDaemonDomainRestore() to restore a domain after
 * saving.
 * Note that for remote Xen Daemon the file path will be interpreted in
 * the remote host.
 *
 * Returns 0 in case of success, -1 (with errno) in case of error.
 */
int
xenDaemonDomainSave(virDomainPtr domain, const char *filename)
{
    if ((domain == NULL) || (domain->conn == NULL) || (domain->name == NULL) ||
        (filename == NULL)) {
        virXendError((domain ? domain->conn : NULL), VIR_ERR_INVALID_ARG,
	             __FUNCTION__);
        return(-1);
    }
    return xend_op(domain->conn, domain->name, "op", "save", "file", filename, NULL);
}

/**
 * xenDaemonDomainRestore:
 * @conn: pointer to the Xem Daemon block
 * @filename: path for the output file
 *
 * This method will restore a domain saved to disk by xenDaemonDomainSave().
 * Note that for remote Xen Daemon the file path will be interpreted in
 * the remote host.
 *
 * Returns 0 in case of success, -1 (with errno) in case of error.
 */
int
xenDaemonDomainRestore(virConnectPtr conn, const char *filename)
{
    if ((conn == NULL) || (filename == NULL)) {
        /* this should be caught at the interface but ... */
        virXendError(conn, VIR_ERR_INVALID_ARG, __FUNCTION__);
        return (-1);
    }
    return xend_op(conn, "", "op", "restore", "file", filename, NULL);
}

/**
 * xenDaemonDomainGetMaxMemory:
 * @domain: pointer to the domain block
 *
 * Ask the Xen Daemon for the maximum memory allowed for a domain
 *
 * Returns the memory size in kilobytes or 0 in case of error.
 */
unsigned long
xenDaemonDomainGetMaxMemory(virDomainPtr domain)
{
    unsigned long ret = 0;
    struct sexpr *root;

    if ((domain == NULL) || (domain->conn == NULL) || (domain->name == NULL)) {
        virXendError((domain ? domain->conn : NULL), VIR_ERR_INVALID_ARG,
	             __FUNCTION__);
        return(-1);
    }

    /* can we ask for a subset ? worth it ? */
    root = sexpr_get(domain->conn, "/xend/domain/%s?detail=1", domain->name);
    if (root == NULL)
        return(0);

    ret = (unsigned long) sexpr_u64(root, "domain/memory") << 10;
    sexpr_free(root);

    return(ret);
}

/**
 * xenDaemonDomainSetMaxMemory:
 * @domain: pointer to the Domain block
 * @memory: The maximum memory in kilobytes
 *
 * This method will set the maximum amount of memory that can be allocated to
 * a domain.  Please note that a domain is able to allocate up to this amount
 * on its own (although under normal circumstances, memory allocation for a
 * domain is only done through xend_set_memory()).
 *
 * Returns 0 for success; -1 (with errno) on error
 */
int
xenDaemonDomainSetMaxMemory(virDomainPtr domain, unsigned long memory)
{
    char buf[1024];

    if ((domain == NULL) || (domain->conn == NULL) || (domain->name == NULL)) {
        virXendError((domain ? domain->conn : NULL), VIR_ERR_INVALID_ARG,
	             __FUNCTION__);
        return(-1);
    }
    snprintf(buf, sizeof(buf), "%lu", memory >> 10);
    return xend_op(domain->conn, domain->name, "op", "maxmem_set", "memory",
                   buf, NULL);
}

/**
 * xenDaemonDomainDumpXML:
 * @domain: a domain object
 *
 * Provide an XML description of the domain.
 *
 * Returns a 0 terminated UTF-8 encoded XML instance, or NULL in case of error.
 *         the caller must free() the returned value.
 */
char *
xenDaemonDomainDumpXML(virDomainPtr domain)
{
    char *ret = NULL;
    struct sexpr *root;

    if ((domain == NULL) || (domain->conn == NULL) || (domain->name == NULL)) {
        virXendError((domain ? domain->conn : NULL), VIR_ERR_INVALID_ARG,
	             __FUNCTION__);
        return(NULL);
    }

    root = sexpr_get(domain->conn, "/xend/domain/%s?detail=1", domain->name);
    if (root == NULL)
        return (NULL);

    ret = xend_parse_sexp_desc(root);
    sexpr_free(root);

    return (ret);
}

/**
 * xenDaemonDomainGetInfo:
 * @domain: a domain object
 * @info: pointer to a virDomainInfo structure allocated by the user
 *
 * This method looks up information about a domain and update the
 * information block provided.
 *
 * Returns 0 in case of success, -1 in case of error
 */
int
xenDaemonDomainGetInfo(virDomainPtr domain, virDomainInfoPtr info)
{
    struct sexpr *root;
    int ret;

    if ((domain == NULL) || (domain->conn == NULL) || (domain->name == NULL) ||
        (info == NULL)) {
        virXendError((domain ? domain->conn : NULL), VIR_ERR_INVALID_ARG,
	             __FUNCTION__);
        return(-1);
    }


    root = sexpr_get(domain->conn, "/xend/domain/%s?detail=1", domain->name);
    if (root == NULL)
        return (-1);

    ret = sexpr_to_xend_domain_info(root, info);
    sexpr_free(root);
    return (ret);
}

/**
 * xenDaemonDomainLookupByName:
 * @conn: A xend instance
 * @name: The name of the domain
 *
 * This method looks up information about a domain and returns
 * it in the form of a struct xend_domain.  This should be
 * free()'d when no longer needed.
 *
 * Returns domain info on success; NULL (with errno) on error
 */
virDomainPtr
xenDaemonDomainLookupByName(virConnectPtr conn, const char *domname)
{
    struct sexpr *root;
    virDomainPtr ret = NULL;

    if ((conn == NULL) || (domname == NULL)) {
        virXendError(conn, VIR_ERR_INVALID_ARG, __FUNCTION__);
	return(NULL);
    }
    root = sexpr_get(conn, "/xend/domain/%s?detail=1", domname);
    if (root == NULL)
        goto error;

    ret = sexpr_to_domain(conn, root);

error:
    sexpr_free(root);
    return(ret);
}