xdb_file.c

jabber server jabber server jabber server jabber server

/* --------------------------------------------------------------------------
 *
 * License
 *
 * The contents of this file are subject to the Jabber Open Source License
 * Version 1.0 (the "JOSL").  You may not copy or use this file, in either
 * source code or executable form, except in compliance with the JOSL. You
 * may obtain a copy of the JOSL at http://www.jabber.org/ or at
 * http://www.opensource.org/.  
 *
 * Software distributed under the JOSL is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied.  See the JOSL
 * for the specific language governing rights and limitations under the
 * JOSL.
 *
 * Copyrights
 * 
 * Portions created by or assigned to Jabber.com, Inc. are 
 * Copyright (c) 1999-2002 Jabber.com, Inc.  All Rights Reserved.  Contact
 * information for Jabber.com, Inc. is available at http://www.jabber.com/.
 *
 * Portions Copyright (c) 1998-1999 Jeremie Miller.
 * 
 * Acknowledgements
 * 
 * Special thanks to the Jabber Open Source Contributors for their
 * suggestions and support of Jabber.
 * 
 * Alternatively, the contents of this file may be used under the terms of the
 * GNU General Public License Version 2 or later (the "GPL"), in which case
 * the provisions of the GPL are applicable instead of those above.  If you
 * wish to allow use of your version of this file only under the terms of the
 * GPL and not to allow others to use your version of this file under the JOSL,
 * indicate your decision by deleting the provisions above and replace them
 * with the notice and other provisions required by the GPL.  If you do not
 * delete the provisions above, a recipient may use your version of this file
 * under either the JOSL or the GPL. 
 * 
 * 
 * --------------------------------------------------------------------------*/
 
#include <jabberd.h>
#include <dirent.h>

#define FILES_PRIME 509

/* 
gcc -fPIC -shared -o xdb_file.so xdb_file.c -I../src

needs to have a spool section in the config:

<load><xdb_file>../load/xdb_file.so</xdb_file></load>
<xdb_file xmlns="jabber:config:xdb_file">
  <spool>/var/spool/jabber</spool>
</xdb_file>

within the spool, xdb_file will make folders for hostnames it has to save data for, and within those save username.xml files containing a user's namespaces

*/

typedef struct cacher_struct
{
    char *fname;
    xmlnode file;
    int lastset;
} *cacher, _cacher;

typedef struct xdbf_struct
{
    char *spool;
    instance i;
    int timeout;
    xht cache;
    int sizelimit;
    int use_hashspool;
} *xdbf, _xdbf;

void _xdb_file_purge(xht h, const char *key, void *data, void *arg)
{
    xdbf xf = (xdbf)arg;
    cacher c = (cacher)data;
    int now = time(NULL);

    if((now - c->lastset) > xf->timeout)
    {
        log_debug2(ZONE, LOGT_STORAGE, "purging %s",c->fname);
        xhash_zap(xf->cache,c->fname);
        xmlnode_free(c->file);
    }
}

/* walk the table looking for stale files to expire */
result xdb_file_purge(void *arg)
{
    xdbf xf = (xdbf)arg;

    log_debug2(ZONE, LOGT_STORAGE, "purge check");
    xhash_walk(xf->cache,_xdb_file_purge,(void *)xf);

    return r_DONE;
}

/* this function acts as a loader, getting xml data from a file */
xmlnode xdb_file_load(char *host, char *fname, xht cache)
{
    xmlnode data = NULL;
    cacher c;
    int fd;

    log_debug2(ZONE, LOGT_STORAGE, "loading %s",fname);

    /* first, check the cache */
    if((c = xhash_get(cache,fname)) != NULL)
        return c->file;

    /* test the file first, so we can be more descriptive */
    fd = open(fname,O_RDONLY);
    if(fd < 0) {
	if (errno == ENOENT) {
	    log_debug2(ZONE, LOGT_STORAGE, "xdb_file failed to open file %s: %s", fname, strerror(errno));
	} else {
	    log_warn(host,"xdb_file failed to open file %s: %s",fname,strerror(errno));
	}
    } else {
        close(fd);
        data = xmlnode_file(fname);
    }

    /* if there's nothing on disk, create an empty root node */
    if(data == NULL)
        data = xmlnode_new_tag("xdb");

    log_debug2(ZONE, LOGT_STORAGE, "caching %s",fname);
    c = pmalloco(xmlnode_pool(data),sizeof(_cacher));
    c->fname = pstrdup(xmlnode_pool(data),fname);
    c->lastset = time(NULL);
    c->file = data;
    xhash_put(cache,c->fname,c);

    return data;
}

/**
 * calculate the left-most four digits of the SHA-1 hash over a filename
 *
 * @param filename the filename
 * @param digit01 where to place the first two digits (size 3 chars!)
 * @param digit23 where to place the next two digits (size 3 chars!)
 */
void _xdb_get_hashes(const char *filename, char digit01[3], char digit23[3])
{
    char hashedfilename[9];
    
    /* generate a hash over the filename */
    bzero(hashedfilename, sizeof(hashedfilename));
    bzero(digit01, sizeof(digit01));
    bzero(digit23, sizeof(digit23));
    crc32_r(filename, hashedfilename);
    log_debug2(ZONE, LOGT_STORAGE, "hash of %s is %s", filename, hashedfilename);
    memcpy(digit01, hashedfilename+1, 2);
    memcpy(digit23, hashedfilename+4, 2);

    return;
}

/**
 * create folders in the spool
 *
 * @param spoolroot the root of the spool
 * @param host the host for which the directory should be created
 * @param hash1 the hash for the first subdirectory
 * @param hash2 the second subdirectory
 * @param use_subdirs true if file should be located in subdirectories
 * @return 1 on success, 0 on failure
 */
int _xdb_gen_dirs(spool sp, const char *spoolroot, char *host, const char *hash1, const char *hash2, int use_subdirs)
{
    struct stat s;
    char *tmp;

    /* check that the root of the spool structure exists */
    if (stat(spoolroot, &s) < 0)
    {
	log_error(host, "the spool root directory %s does not seem to exist", spoolroot);
	return 0;
    }

    /* check and create the host-named folder */
    spooler(sp, spoolroot, "/", host, sp);
    tmp = spool_print(sp);
    if(stat(tmp,&s) < 0 && mkdir(tmp, S_IRWXU) < 0)
    {
	log_error(host, "could not create spool folder %s: %s", tmp, strerror(errno));
	return 0;
    }

    if (use_subdirs)
    {
	/* check or create the first level subdirectory */
	spooler(sp, "/", hash1, sp);
	tmp = spool_print(sp);
	if(stat(tmp,&s) < 0 && mkdir(tmp, S_IRWXU) < 0)
	{
	    log_error(host, "could not create spool folder %s: %s", tmp, strerror(errno));
	    return 0;
	}

	/* check or create the second level subdirectory */
	spooler(sp, "/", hash2, sp);
	tmp = spool_print(sp);
	if(stat(tmp,&s) < 0 && mkdir(tmp, S_IRWXU) < 0)
	{
	    log_error(host, "could not create spool folder %s: %s", tmp, strerror(errno));
	    return 0;
	}
    }

    return 1;
}

/**
 * utility that generates the filename for a spool file
 *
 * @param create true if the directory for the file should be generated
 * @param p pool that should be used for string operations
 * @param spl location for the spool root
 * @param host host of the xdb request (the 'spool folder')
 * @param file the basename of the xdb file
 * @param ext the extension for the xdb file
 * @param use_subdirs true if file should be located in subdirectories
 * @return concatenated string of the form spl+"/"+somehashes+"/"+file+"."+ext
 */
char *xdb_file_full(int create, pool p, char *spl, char *host, char *file, char *ext, int use_subdirs)
{
    spool sp = spool_new(p);
    char digit01[3], digit23[3];
    char *ret;
    char *filename;

    filename = spools(p, file, ".", ext, p);

    _xdb_get_hashes(filename, digit01, digit23);

    /* is the creation of the folder requested? */
    if(create)
    {
	if (!_xdb_gen_dirs(sp, spl, host, digit01, digit23, use_subdirs))
	{
	    log_error(host, "xdb request failed, necessary directory was not created");
	    return NULL;
	}
    } else if (use_subdirs) {
	spooler(sp, spl, "/", host, "/", digit01, "/", digit23, sp);
    } else {
	spooler(sp, spl, "/", host, sp);
    }

    /* full path to file */
    spooler(sp,"/",filename, sp);
    ret = spool_print(sp);

    return ret;
}

/* the callback to handle xdb packets */
result xdb_file_phandler(instance i, dpacket p, void *arg)
{
    char *full, *ns, *act, *match;
    xdbf xf = (xdbf)arg;
    xmlnode file, top, data;
    int ret = 0, flag_set = 0;

    log_debug2(ZONE, LOGT_STORAGE|LOGT_DELIVER, "handling xdb request %s",xmlnode2str(p->x));

    if((ns = xmlnode_get_attrib(p->x,"ns")) == NULL)
        return r_ERR;

    if(j_strcmp(xmlnode_get_attrib(p->x,"type"), "set") == 0)
        flag_set = 1;

    /* is this request specific to a user or global data? use that for the file name */
    if(p->id->user != NULL)
        full = xdb_file_full(flag_set, p->p, xf->spool, p->id->server, p->id->user, "xml", xf->use_hashspool);
    else
        full = xdb_file_full(flag_set, p->p, xf->spool, p->id->server, "global", "xdb", 0);

    if(full == NULL)
        return r_ERR;

    /* load the data from disk/cache */
    top = file = xdb_file_load(p->host, full, xf->cache);

    /* if we're dealing w/ a resource, just get that element */
    if(p->id->resource != NULL)
    {
        if((top = xmlnode_get_tag(top,spools(p->p,"res?id=",p->id->resource,p->p))) == NULL)
        {
            top = xmlnode_insert_tag(file,"res");
            xmlnode_put_attrib(top,"id",p->id->resource);
        }
    }

    /* just query the relevant namespace */
    data = xmlnode_get_tag(top,spools(p->p,"?xdbns=",ns,p->p));