libldom/sparc/ldom_xmpp_client.c

	ldom_xmpp_client.c revision f044df33d9fe9e8e3ed7344a8b548b17f20709f2
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
 */

/*
 * ldom_xmpp_client.c   Extensible Messaging and Presence Protocol (XMPP)
 *
 * Implement an xmpp client to subscribe for domain events from the ldmd.
 * Notify fmd module clients upon receiving the events.
 *
 */

#include "ldom_xmpp_client.h"
#include "ldom_alloc.h"
#include "ldom_utils.h"

#include <stdio.h>
#include <signal.h>
#include <strings.h>
#include <unistd.h>
#include <errno.h>

#include <netdb.h>
#include <dlfcn.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <libxml/parser.h>
#include <openssl/ssl.h>

typedef enum conn_state {
    CONN_STATE_UNKNOWN,
    CONN_STATE_TLS,
    CONN_STATE_FEATURE,
    CONN_STATE_LDM_INTERFACE,
    CONN_STATE_LDM_EVENT,
    CONN_STATE_DONE,
    CONN_STATE_FAILURE,
    CONN_STATE_MAX
} conn_state_t;

typedef struct xmpp_conn {
    int         fd;
    int         state;
    boolean_t       tls_started;
    SSL         *ssl;
    xmlParserCtxtPtr    parser;
} xmpp_conn_t;

/* Forward declaration */
static int iowrite(xmpp_conn_t *conn, char *buf, int size);
static void start_element(void *state, const xmlChar *name,
    const xmlChar **attrs);
static void end_element(void *state, const xmlChar *name);
static void error_func(void *state, const char *msg, ...);
static void xmpp_close(xmpp_conn_t *conn);
static int start_tls(xmpp_conn_t *conn);
static void handle_ldm_resp(xmpp_conn_t *conn, char *buf, size_t buf_size);
static void handle_ldm_event(xmpp_conn_t *conn, char *buf, size_t buf_size);

static int xmpp_enable = 0;
static int xmpp_notify_pipe[2];
static pthread_t xmpp_tid = 0;
static pthread_mutex_t xmpp_tid_lock = PTHREAD_MUTEX_INITIALIZER;

static client_list_t clt_list = { NULL, NULL, PTHREAD_MUTEX_INITIALIZER };


#define FUNCTION_ADD(_function, _pointer, _lib, _func_name, _ret)   \
    _function = (_pointer)dlsym(_lib, _func_name);          \
    if (_function == NULL) {                    \
        _ret += -1;                     \
    }

/*
 * Prototypes and pointers to functions needed from libssl.
 */
typedef void (*SSL_load_error_strings_pt)(void);
typedef int (*SSL_library_init_pt)(void);
typedef SSL_CTX *(*SSL_CTX_new_pt)(const SSL_METHOD *method);
typedef SSL_METHOD *(*SSLv23_client_method_pt)(void);
typedef int (*SSL_write_pt)(SSL *ssl, const void *buf, int num);
typedef int (*SSL_CTX_use_PrivateKey_file_pt)(SSL_CTX *ctx, const char *file,
    int type);
typedef void (*RAND_seed_pt)(const void *buf, int num);
typedef int (*SSL_get_error_pt)(const SSL *ssl, int ret);
typedef long (*ERR_get_error_pt)(void);
typedef char *(*ERR_error_string_pt)(unsigned long e, char *buf);
typedef int (*SSL_connect_pt)(SSL *ssl);
typedef int (*SSL_CTX_use_certificate_chain_file_pt)(SSL_CTX *ctx,
    const char *file);
typedef int (*SSL_set_fd_pt)(SSL *ssl, int fd);
typedef void (*SSL_free_pt)(SSL *ssl);
typedef int (*SSL_read_pt)(SSL *ssl, void *buf, int num);
typedef SSL *(*SSL_new_pt)(SSL_CTX *ctx);
typedef SSL_CTX *(*SSL_get_SSL_CTX_pt)(const SSL *ssl);
typedef void (*SSL_CTX_free_pt)(SSL_CTX *ctx);

static SSL_load_error_strings_pt SSL_load_error_strings_f = NULL;
static SSL_library_init_pt SSL_library_init_f = NULL;
static SSL_CTX_new_pt SSL_CTX_new_f = NULL;
static SSLv23_client_method_pt SSLv23_client_method_f = NULL;
static SSL_write_pt SSL_write_f = NULL;
static SSL_CTX_use_PrivateKey_file_pt SSL_CTX_use_PrivateKey_file_f = NULL;
static RAND_seed_pt RAND_seed_f = NULL;
static SSL_get_error_pt SSL_get_error_f = NULL;
static ERR_get_error_pt ERR_get_error_f = NULL;
static ERR_error_string_pt ERR_error_string_f = NULL;
static SSL_connect_pt SSL_connect_f = NULL;
static SSL_CTX_use_certificate_chain_file_pt
SSL_CTX_use_certificate_chain_file_f = NULL;
static SSL_set_fd_pt SSL_set_fd_f = NULL;
static SSL_free_pt SSL_free_f = NULL;
static SSL_read_pt SSL_read_f = NULL;
static SSL_new_pt SSL_new_f = NULL;
static SSL_get_SSL_CTX_pt SSL_get_SSL_CTX_f = NULL;
static SSL_CTX_free_pt SSL_CTX_free_f = NULL;

static void *xmpp_dl = NULL;

static ldom_event_info_t event_table[] = {
    { LDOM_EVENT_UNKNOWN, "unknown" },
    { LDOM_EVENT_ADD, "add-domain" },
    { LDOM_EVENT_REMOVE, "remove-domain" },
    { LDOM_EVENT_BIND, "bind-domain" },
    { LDOM_EVENT_UNBIND, "unbind-domain" },
    { LDOM_EVENT_START, "start-domain" },
    { LDOM_EVENT_STOP, "stop-domain" },
    { LDOM_EVENT_RESET, "domain-reset" },
    { LDOM_EVENT_PANIC, "panic-domain" },
    { LDOM_EVENT_MAX, NULL }
};
static int event_table_size = \
        sizeof (event_table) / sizeof (ldom_event_info_t);

static xmlSAXHandler xml_handler = {
    NULL,       /* internalSubsetSAXFunc */
    NULL,       /* isStandaloneSAXFunc */
    NULL,       /* hasInternalSubsetSAXFunc */
    NULL,       /* hasExternalSubsetSAXFunc */
    NULL,       /* resolveEntitySAXFunc */
    NULL,       /* getEntitySAXFunc */
    NULL,       /* entityDeclSAXFunc */
    NULL,       /* notationDeclSAXFunc */
    NULL,       /* attributeDeclSAXFunc */
    NULL,       /* elementDeclSAXFunc */
    NULL,       /* unparsedEntityDeclSAXFunc */
    NULL,       /* setDocumentLocatorSAXFunc */
    NULL,       /* startDocumentSAXFunc */
    NULL,       /* endDocumentSAXFunc */
    start_element,  /* startElementSAXFunc */
    end_element,    /* endElementSAXFunc */
    NULL,       /* referenceSAXFunc */
    NULL,       /* charactersSAXFunc */
    NULL,       /* ignorableWhitespaceSAXFunc */
    NULL,       /* processingInstructionSAXFunc */
    NULL,       /* commentSAXFunc */
    NULL,       /* warningSAXFunc */
    error_func, /* errorSAXFunc */
    NULL,       /* fatalErrorSAXFunc */
    NULL,       /* getParameterEntitySAXFunc */
    NULL,       /* cdataBlockSAXFunc */
    NULL,       /* externalSubsetSAXFunc */
    0,      /* unsigned int */
    NULL,       /* void * _private */
    NULL,       /* startElementNsSAX2Func */
    NULL,       /* endElementNsSAX2Func */
    NULL        /* xmlStructuredErrorFunc */
};

static void
end_element(void *state, const xmlChar *name)
{
    xmpp_conn_t *conn = (xmpp_conn_t *)state;

    if (xmlStrcmp(name, STREAM_NODE) == 0) {
        conn->state = CONN_STATE_DONE;
    } else if (xmlStrcmp(name, STARTTLS_NODE) == 0) {
        (void) iowrite(conn, START_TLS, strlen(START_TLS));
    } else if (xmlStrcmp(name, PROCEED_NODE) == 0) {
        if (start_tls(conn)) {
            conn->state = CONN_STATE_FAILURE;
        }
    } else if (xmlStrcmp(name, FEATURE_NODE) == 0) {
        if (conn->state == CONN_STATE_TLS) {
            conn->state = CONN_STATE_FEATURE;
            (void) iowrite(conn, (char *)LDM_REG_DOMAIN_EVENTS,
                strlen((char *)LDM_REG_DOMAIN_EVENTS));
        }
    } else if (xmlStrcmp(name, XML_LDM_INTERFACE) == 0) {
        conn->state = CONN_STATE_LDM_INTERFACE;
    } else if (xmlStrcmp(name, XML_LDM_EVENT) == 0) {
        conn->state = CONN_STATE_LDM_EVENT;
    } else if (xmlStrcmp(name, XML_FAILURE) == 0) {
        conn->state = CONN_STATE_FAILURE;
    }
}

/*ARGSUSED*/
static void
start_element(void *state, const xmlChar *name, const xmlChar **attrs)
{
}

/*ARGSUSED*/
static void
error_func(void *state, const char *msg, ...)
{
}

static int
xmpp_connect(xmpp_conn_t *conn)
{
    int sock;
    struct sockaddr_in serveraddr;

    if ((sock = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
        return (-1);
    }

    serveraddr.sin_family = AF_INET;
    serveraddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
    serveraddr.sin_port = htons(XMPP_DEFAULT_PORT);
    if (connect(sock, (struct sockaddr *)(&serveraddr),
        sizeof (struct sockaddr_in)) < 0) {
        return (-1);
    }

    (void) bzero(conn, sizeof (xmpp_conn_t));
    conn->fd = sock;
    conn->tls_started = B_FALSE;

    conn->parser = xmlCreatePushParserCtxt(&xml_handler, (void *) conn,
        NULL, NULL, NULL);
    if (conn->parser == NULL) {
        return (-1);
    }

    return (0);
}

static void
xmpp_close(xmpp_conn_t *conn)
{
    (void) close(conn->fd);
    conn->fd = -1;
    conn->state = CONN_STATE_UNKNOWN;
    if (conn->parser != NULL) {
        xmlFreeParserCtxt(conn->parser);
        conn->parser = NULL;
    }
    if (conn->tls_started) {
        SSL_free_f(conn->ssl);
        conn->ssl = NULL;
    }
    conn->tls_started = B_FALSE;
}

static int
ioread(xmpp_conn_t *conn, char *buf, int size)
{
    int count;
    if (conn->tls_started) {
        count = SSL_read_f(conn->ssl, buf, size);
    } else {
        count = read(conn->fd, buf, size);
    }
    if (count <= 0) {
        conn->state = CONN_STATE_FAILURE;
    }

    return (count);
}

static int
iowrite(xmpp_conn_t *conn, char *buf, int size)
{
    int count;

    if (conn->tls_started) {
        count = SSL_write_f(conn->ssl, buf, size);
    } else {
        count = send(conn->fd, buf, size, 0);
    }
    if (count <= 0) {
        conn->state = CONN_STATE_FAILURE;
    }

    return (count);
}

/*
 * notify_event()
 * Description:
 *     Notify all clients an event by going through the client list and invoke
 *     the callback functions.
 */
static void
notify_event(ldom_event_t event, char *ldom_name)
{
    client_info_t *p;

    (void) pthread_mutex_lock(&clt_list.lock);

    for (p = clt_list.head; p != NULL; p = p->next) {
        p->cb(ldom_name, event, p->data);
    }

    (void) pthread_mutex_unlock(&clt_list.lock);
}

/*
 * xmpp_client_thr()
 * Description:
 *     The main entry fo the xmpp client thread.
 */
/*ARGSUSED*/
static void *
xmpp_client_thr(void *data)
{
    int rc = 0;
    int cnt;
    char buf[XMPP_BUF_SIZE];
    xmpp_conn_t conn;
    pollfd_t pollfd[2];
    struct pollfd *pipe_fd = &pollfd[0];
    struct pollfd *recv_fd = &pollfd[1];

    while (xmpp_enable) {
        /* clear the conn struct */
        bzero(&conn, sizeof (xmpp_conn_t));

        /* keep making a connection until successfully */
        do {
            if (rc = xmpp_connect(&conn))
                (void) sleep(XMPP_SLEEP);
        } while (rc != 0 && xmpp_enable);

        /* write the stream node */
        cnt = iowrite(&conn, (char *)STREAM_START,
            strlen((char *)STREAM_START));
        if (cnt != strlen((char *)STREAM_START)) {
            xmpp_close(&conn);
            (void) sleep(XMPP_SLEEP);
            continue;
        }

        pipe_fd->fd = xmpp_notify_pipe[1];  /* notification pipe */
        pipe_fd->events = POLLIN;
        recv_fd->fd = conn.fd;          /* XMPP connection */
        recv_fd->events = POLLIN;

        /* process input */
        while ((conn.state != CONN_STATE_FAILURE) &&
            (conn.state != CONN_STATE_DONE) && xmpp_enable) {

            /* Wait for xmpp input or the notification */
            pipe_fd->revents = 0;
            recv_fd->revents = 0;
            if (poll(pollfd, 2, -1) <= 0) {
                break;
            } else if (pipe_fd->revents & POLLIN) {
                /* Receive a notification to exit */
                xmpp_close(&conn);
                pthread_exit((void *)NULL);
            }

            /*
             * Assume the document size of a ldmd response is
             * less than 1KB. This assumption is valid with the
             * current ldmd implementation.
             * Should the document size exceeds 1KB, the buffer
             * size should be revisited accordingly.
             */
            (void) memset(buf, 0, XMPP_BUF_SIZE);
            cnt = ioread(&conn, buf, XMPP_BUF_SIZE);
            if (cnt <= 0)
                break;
            if (rc = xmlParseChunk(conn.parser, buf, cnt, 0)) {
                conn.state = CONN_STATE_FAILURE;
            }

            switch (conn.state) {
            case CONN_STATE_LDM_INTERFACE:
                handle_ldm_resp(&conn, buf, cnt);
                break;
            case CONN_STATE_LDM_EVENT:
                handle_ldm_event(&conn, buf, cnt);
                break;
            default:
                break;
            }

            /*
             * For now, the parser is reset after every read.
             * It should only be reset once after the ssl is opened
             * in the start_tls().
             */
            (void) xmlCtxtResetPush(conn.parser, NULL, NULL, NULL,
                NULL);
        }
        xmpp_close(&conn);
        (void) sleep(XMPP_SLEEP);
    }
    return (NULL);
}

/*
 * find_client()
 * Description:
 *     Walk to the list to find a libldom client
 */
static client_info_t *
find_client(ldom_hdl_t *lhp)
{
    client_info_t *p;

    for (p = clt_list.head; p != NULL; p = p->next) {
        if (p->lhp == lhp)
            return (p);
    }

    return (NULL);
}

/*
 * xmpp_add_client()
 * Description:
 *     Add a libldom client from the client list.
 */
int
xmpp_add_client(ldom_hdl_t *lhp, ldom_reg_cb_t cb, ldom_cb_arg_t data)
{
    client_info_t *clt;

    (void) pthread_mutex_lock(&clt_list.lock);
    if (find_client(lhp)) {
        /* already exists */
        (void) pthread_mutex_unlock(&clt_list.lock);
        return (-1);
    }

    /* new client */
    clt = (client_info_t *)ldom_alloc(sizeof (client_info_t));
    clt->lhp = lhp;
    clt->cb = cb;
    clt->data = data;
    clt->next = NULL;
    clt->prev = NULL;

    if (clt_list.head == NULL && clt_list.tail == NULL) {
        clt_list.head = clt;
        clt_list.tail = clt;
    } else {
        /* append to the list */
        clt->prev = clt_list.tail;
        clt_list.tail->next  = clt;
        clt_list.tail = clt;
    }

    (void) pthread_mutex_unlock(&clt_list.lock);
    return (0);
}

/*
 * xmpp_remove_client()
 * Description:
 *     Remove a libldom client from the client list.
 */
int
xmpp_remove_client(ldom_hdl_t *lhp)
{
    client_info_t *p;

    (void) pthread_mutex_lock(&clt_list.lock);
    if ((p = find_client(lhp)) == NULL) {
        /* not present */
        (void) pthread_mutex_unlock(&clt_list.lock);
        return (-1);
    }

    if (clt_list.head == p && clt_list.tail == p) {
        /* single item list */
        clt_list.head = NULL;
        clt_list.tail = NULL;
    } else if (clt_list.head == p) {
        /* delete the head */
        clt_list.head = p->next;
        clt_list.head->prev = NULL;
    } else if (clt_list.tail == p) {
        /* delete the tail */
        clt_list.tail = p->prev;
        clt_list.tail->next = NULL;
    } else {
        /* delete a middle node */
        p->next->prev = p->prev;
        p->prev->next = p->next;
    }
    ldom_free(p, sizeof (client_info_t));

    (void) pthread_mutex_unlock(&clt_list.lock);
    return (0);
}

/*
 * xmpp_stop()
 * Description:
 *     Stop the xmpp client thread
 */
/*ARGSUSED*/
void
xmpp_stop(void)
{
    (void) pthread_mutex_lock(&xmpp_tid_lock);
    xmpp_enable = 0;
    if (xmpp_tid) {
        /*
         * Write a byte to the pipe to notify the xmpp thread to exit.
         * Then wait for it to exit.
         */
        (void) write(xmpp_notify_pipe[0], "1", 1);
        (void) pthread_join(xmpp_tid, NULL);
        xmpp_tid = 0;
    }
    (void) pthread_mutex_unlock(&xmpp_tid_lock);
}

/*
 * xmpp_start()
 * Description:
 *     Start the xmpp client thread if have not done so.
 */
void
xmpp_start(void)
{
    xmpp_conn_t conn;

    /* Check if the xmmp thread has already started */
    (void) pthread_mutex_lock(&xmpp_tid_lock);
    if (xmpp_tid != 0) {
        (void) pthread_mutex_unlock(&xmpp_tid_lock);
        return;
    }

    /* Check if the ldmd supports xmpp by opening a connection */
    if (xmpp_connect(&conn)) {
        (void) pthread_mutex_unlock(&xmpp_tid_lock);
        return;
    }
    xmpp_close(&conn);
    xmpp_enable = 1;

    /*
     * create xmpp client thread for receiving domain events.
     * The notification pipe is for stopping the thread.
     */
    (void) notify_setup(xmpp_notify_pipe);
    (void) pthread_create(&xmpp_tid, NULL, xmpp_client_thr, NULL);

    (void) pthread_mutex_unlock(&xmpp_tid_lock);

    /*
     * Register a function to stop the above thread upon a termination
     */
    (void) atexit(xmpp_stop);
}

/*
 * This routine will run through the first time we get a remote XMPP
 * connection. After that we will not need to do this again. It cannot be run
 * from main thread at start as we need to alert remote users if the TLS
 * handshake failed.
 */
static int
load_SSL_lib()
{
    int ret = 0;

    /* If we have already opened the library no need to do it again. */
    if (xmpp_dl != NULL)
        return (0);

    /*
     * If the libssl.so in not in the default path, attempt to open it
     * under /usr/sfw/lib.
     */
    xmpp_dl = dlopen("libssl.so", RTLD_NOW);
    if (xmpp_dl == NULL) {
        xmpp_dl = dlopen("/usr/sfw/lib/libssl.so", RTLD_NOW);
        if (xmpp_dl == NULL)
            return (-1);
    }

    FUNCTION_ADD(SSL_load_error_strings_f, SSL_load_error_strings_pt,
        xmpp_dl, "SSL_load_error_strings", ret);
    FUNCTION_ADD(SSL_library_init_f, SSL_library_init_pt, xmpp_dl,
        "SSL_library_init", ret);
    FUNCTION_ADD(SSL_CTX_new_f, SSL_CTX_new_pt, xmpp_dl,
        "SSL_CTX_new", ret);
    FUNCTION_ADD(SSLv23_client_method_f, SSLv23_client_method_pt, xmpp_dl,
        "SSLv23_client_method", ret);
    FUNCTION_ADD(SSL_write_f, SSL_write_pt, xmpp_dl, "SSL_write", ret);
    FUNCTION_ADD(SSL_CTX_use_PrivateKey_file_f,
        SSL_CTX_use_PrivateKey_file_pt, xmpp_dl,
        "SSL_CTX_use_PrivateKey_file", ret);
    FUNCTION_ADD(RAND_seed_f, RAND_seed_pt, xmpp_dl, "RAND_seed", ret);
    FUNCTION_ADD(SSL_get_error_f, SSL_get_error_pt, xmpp_dl,
        "SSL_get_error", ret);
    FUNCTION_ADD(ERR_get_error_f, ERR_get_error_pt, xmpp_dl,
        "ERR_get_error", ret);
    FUNCTION_ADD(ERR_error_string_f, ERR_error_string_pt, xmpp_dl,
        "ERR_error_string", ret);
    FUNCTION_ADD(SSL_connect_f, SSL_connect_pt, xmpp_dl, "SSL_connect",
        ret);
    FUNCTION_ADD(SSL_CTX_use_certificate_chain_file_f,
        SSL_CTX_use_certificate_chain_file_pt, xmpp_dl,
        "SSL_CTX_use_certificate_chain_file", ret);
    FUNCTION_ADD(SSL_set_fd_f, SSL_set_fd_pt, xmpp_dl, "SSL_set_fd", ret);
    FUNCTION_ADD(SSL_free_f, SSL_free_pt, xmpp_dl, "SSL_free", ret);
    FUNCTION_ADD(SSL_read_f, SSL_read_pt, xmpp_dl, "SSL_read", ret);
    FUNCTION_ADD(SSL_new_f, SSL_new_pt, xmpp_dl, "SSL_new", ret);
    FUNCTION_ADD(SSL_get_SSL_CTX_f, SSL_get_SSL_CTX_pt, xmpp_dl,
        "SSL_get_SSL_CTX", ret);
    FUNCTION_ADD(SSL_CTX_free_f, SSL_CTX_free_pt, xmpp_dl,
        "SSL_CTX_free", ret);

    if (ret < 0)
        return (-1);
    else
        return (0);
}

/*
 * start_tls()
 * Description:
 *     Load the libssl.so if has not done so and open a ssl connection.
 *     It is assumed that there is one xmpp thread to use the ssl connection.
 *     If multi-thread xmpp clients use the ssl connection, addtional work is
 *     needed to ensure the usage of the ssl be thread-safe.
 */
static int
start_tls(xmpp_conn_t *conn)
{
    int     rv, urand_fd;
    SSL_CTX     *ssl_ctx;
    char        rand_buf[RAND_BUF_SIZE];

    rv = load_SSL_lib();
    if (rv == -1) {
        return (rv);
    }

    urand_fd = open("/dev/random", O_RDONLY);
    if (urand_fd == -1) {
        return (-1);
    }
    (void) read(urand_fd, rand_buf, RAND_BUF_SIZE);

    SSL_library_init_f();
    RAND_seed_f(rand_buf, RAND_BUF_SIZE);

    ssl_ctx = SSL_CTX_new_f(SSLv23_client_method_f());
    if (ssl_ctx == NULL) {
        return (-1);
    }
    conn->ssl = SSL_new_f(ssl_ctx);
    rv = SSL_set_fd_f(conn->ssl, conn->fd);
    if (rv == 0) {
        return (-1);
    }
    rv = SSL_connect_f(conn->ssl);
    if (rv != 1) {
        return (-1);
    }
    conn->tls_started = B_TRUE;
    conn->state = CONN_STATE_TLS;

    (void) iowrite(conn, STREAM_START, strlen(STREAM_START));

    return (0);
}

/*
 * Find and return the first-level subnode (if any) of 'node' which has name
 * 'name'.
 */
xmlNodePtr
xml_find_subnode(xmlNodePtr node, const xmlChar *name)
{
    xmlNodePtr subnode;

    if (node == NULL)
        return (NULL);

    subnode = node->xmlChildrenNode;
    while (subnode != NULL) {
        if (((char *)subnode->name != NULL) &&
            (xmlStrcmp(subnode->name, name) == 0))
            break;
        subnode = subnode->next;
    }

    return (subnode);
}

/*
 * handle_ldm_resp()
 * Description:
 *     Parse the ldmd response of the domain event registration for the failure
 *     status. If found, set the connection to failure so that it will be
 *     closed and a new xmpp connection is established.
 */
void
handle_ldm_resp(xmpp_conn_t *conn, char *buf, size_t buf_size)
{
    xmlDocPtr   xml_output;
    xmlNodePtr  root, resp, status, cmd, action;
    char        *status_str, *action_str;

    if ((xml_output = xmlParseMemory((const char *)buf, buf_size)) == NULL)
        return;
    if ((root = xmlDocGetRootElement(xml_output)) == NULL)
        return;

    /* get the cmd node */
    if ((cmd = xml_find_subnode(root, XML_CMD)) == NULL)
        return;
    if (strcmp((char *)cmd->name, (char *)XML_CMD) != 0)
        return;

    /* get the action node and make sure it is the reg-domain-events */
    if ((action = xml_find_subnode(cmd, XML_ACTION)) == NULL) {
        return;
    }
    if ((action_str = (char *)xmlNodeGetContent(action)) == NULL)
        return;
    if (strcmp(action_str, XML_REGISTER_ACTION) != 0) {
        xmlFree(action_str);
        return;
    }
    xmlFree(action_str);

    /* check the status of the response */
    if ((resp = xml_find_subnode(cmd, XML_RESPONSE)) == NULL)
        return;
    if ((status = xml_find_subnode(resp, XML_STATUS)) == NULL)
        return;
    if ((status_str = (char *)xmlNodeGetContent(status)) == NULL)
        return;
    if (strcmp(status_str, (char *)XML_FAILURE) == 0) {
        conn->state = CONN_STATE_FAILURE;
    }
    xmlFree(status_str);
}

/*
 * handle_ldm_event()
 * Description:
 *     Parse the LDM_event for the ldom name and domain action. Then invokes
 *     the clients's callback to notify them the event.
 */
/*ARGSUSED*/
void
handle_ldm_event(xmpp_conn_t *conn, char *buf, size_t buf_size)
{
    int     i;
    xmlDocPtr   xml_output;
    xmlNodePtr  root, cmd, action, data, envelope, content;
    char        *action_str, *ldom_name;
    ldom_event_t    event = LDOM_EVENT_UNKNOWN;

    if ((xml_output = xmlParseMemory((const char *)buf, buf_size)) == NULL)
        return;
    if ((root = xmlDocGetRootElement(xml_output)) == NULL)
        return;

    /* get the action such as bind-domain, unbind-domain, etc. */
    if ((cmd = xml_find_subnode(root, XML_CMD)) == NULL)
        return;
    if ((action = xml_find_subnode(cmd, XML_ACTION)) == NULL) {
        return;
    }
    if ((action_str = (char *)xmlNodeGetContent(action)) == NULL)
        return;
    for (i = 0; i < event_table_size; i++) {
        if (event_table[i].name != NULL &&
            strcasecmp(event_table[i].name, action_str) == 0) {
            event = event_table[i].id;
            break;
        }
    }
    xmlFree(action_str);

    /* get the ldom name */
    data = xml_find_subnode(cmd, XML_DATA);
    envelope = xml_find_subnode(data, XML_ENVELOPE);
    content = xml_find_subnode(envelope, XML_CONTENT);
    if ((ldom_name = (char *)xmlGetProp(content, XML_ATTR_ID)) == NULL)
        return;

    /* Notifies all the clients the event */
    if (VALID_LDOM_EVENT(event)) {
        notify_event(event, ldom_name);
    }

    xmlFree(ldom_name);
}