src/protocols/jabber/xstream.c

   1 /*
   2  *  This program is free software; you can redistribute it and/or modify
   3  *  it under the terms of the GNU General Public License as published by
   4  *  the Free Software Foundation; either version 2 of the License, or
   5  *  (at your option) any later version.
   6  *
   7  *  This program is distributed in the hope that it will be useful,
   8  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10  *  GNU General Public License for more details.
  11  *
  12  *  You should have received a copy of the GNU General Public License
  13  *  along with this program; if not, write to the Free Software
  14  *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  15  *
  16  *  Jabber
  17  *  Copyright (C) 1998-1999 The Jabber Team http://jabber.org/
  18  */
  19
  20 #include <libxode.h>
  21 #include <time.h>
  22
  23 /* xstream is a way to have a consistent method of handling incoming XML Stream based events... it doesn't handle the generation of an XML Stream, but provides some facilities to help do that */
  24
  25 /******* internal expat callbacks *********/
  26 void _xstream_startElement(xstream xs, const char* name, const char** atts)
  27 {
  28     pool p;
  29
  30     /* if xstream is bad, get outa here */
  31     if(xs->status > XSTREAM_NODE) return;
  32
  33     if(xs->node == NULL)
  34     {
  35         p = pool_heap(5*1024); /* 5k, typically 1-2k each plus copy of self and workspace */
  36         xs->node = xmlnode_new_tag_pool(p,name);
  37         xmlnode_put_expat_attribs(xs->node, atts);
  38
  39         if(xs->status == XSTREAM_ROOT)
  40         {
  41             xs->status = XSTREAM_NODE; /* flag status that we're processing nodes now */
  42             (xs->f)(XSTREAM_ROOT, xs->node, xs->arg); /* send the root, f must free all nodes */
  43             xs->node = NULL;
  44         }
  45     }else{
  46         xs->node = xmlnode_insert_tag(xs->node, name);
  47         xmlnode_put_expat_attribs(xs->node, atts);
  48     }
  49
  50     /* depth check */
  51     xs->depth++;
  52     if(xs->depth > XSTREAM_MAXDEPTH)
  53         xs->status = XSTREAM_ERR;
  54 }
  55
  56
  57 void _xstream_endElement(xstream xs, const char* name)
  58 {
  59     xmlnode parent;
  60
  61     /* if xstream is bad, get outa here */
  62     if(xs->status > XSTREAM_NODE) return;
  63
  64     /* if it's already NULL we've received </stream>, tell the app and we're outta here */
  65     if(xs->node == NULL)
  66     {
  67         xs->status = XSTREAM_CLOSE;
  68         (xs->f)(XSTREAM_CLOSE, NULL, xs->arg);
  69     }else{
  70         parent = xmlnode_get_parent(xs->node);
  71
  72         /* we are the top-most node, feed to the app who is responsible to delete it */
  73         if(parent == NULL)
  74             (xs->f)(XSTREAM_NODE, xs->node, xs->arg);
  75
  76         xs->node = parent;
  77     }
  78     xs->depth--;
  79 }
  80
  81
  82 void _xstream_charData(xstream xs, const char *str, int len)
  83 {
  84     /* if xstream is bad, get outa here */
  85     if(xs->status > XSTREAM_NODE) return;
  86
  87     if(xs->node == NULL)
  88     {
  89         /* we must be in the root of the stream where CDATA is irrelevant */
  90         return;
  91     }
  92
  93     xmlnode_insert_cdata(xs->node, str, len);
  94 }
  95
  96
  97 void _xstream_cleanup(void *arg)
  98 {
  99     xstream xs = (xstream)arg;
 100
 101     xmlnode_free(xs->node); /* cleanup anything left over */
 102     XML_ParserFree(xs->parser);
 103 }
 104
 105
 106 /* creates a new xstream with given pool, xstream will be cleaned up w/ pool */
 107 xstream xstream_new(pool p, xstream_onNode f, void *arg)
 108 {
 109     xstream newx;
 110
 111     if(p == NULL || f == NULL)
 112     {
 113         fprintf(stderr,"Fatal Programming Error: xstream_new() was improperly called with NULL.\n");
 114         return NULL;
 115     }
 116
 117     newx = pmalloco(p, sizeof(_xstream));
 118     newx->p = p;
 119     newx->f = f;
 120     newx->arg = arg;
 121
 122     /* create expat parser and ensure cleanup */
 123     newx->parser = XML_ParserCreate(NULL);
 124     XML_SetUserData(newx->parser, (void *)newx);
 125     XML_SetElementHandler(newx->parser, (void *)_xstream_startElement, (void *)_xstream_endElement);
 126     XML_SetCharacterDataHandler(newx->parser, (void *)_xstream_charData);
 127     pool_cleanup(p, _xstream_cleanup, (void *)newx);
 128
 129     return newx;
 130 }
 131
 132 /* attempts to parse the buff onto this stream firing events to the handler, returns the last known status */
 133 int xstream_eat(xstream xs, char *buff, int len)
 134 {
 135     char *err;
 136     xmlnode xerr;
 137     static char maxerr[] = "maximum node size reached";
 138     static char deeperr[] = "maximum node depth reached";
 139
 140     if(xs == NULL)
 141     {
 142         fprintf(stderr,"Fatal Programming Error: xstream_eat() was improperly called with NULL.\n");
 143         return XSTREAM_ERR;
 144     }
 145
 146     if(len == 0 || buff == NULL)
 147         return xs->status;
 148
 149     if(len == -1) /* easy for hand-fed eat calls */
 150         len = strlen(buff);
 151
 152     if(!XML_Parse(xs->parser, buff, len, 0))
 153     {
 154         err = (char *)XML_ErrorString(XML_GetErrorCode(xs->parser));
 155         xs->status = XSTREAM_ERR;
 156     }else if(pool_size(xmlnode_pool(xs->node)) > XSTREAM_MAXNODE || xs->cdata_len > XSTREAM_MAXNODE){
 157         err = maxerr;
 158         xs->status = XSTREAM_ERR;
 159     }else if(xs->status == XSTREAM_ERR){ /* set within expat handlers */
 160         err = deeperr;
 161     }
 162
 163     /* fire parsing error event, make a node containing the error string */
 164     if(xs->status == XSTREAM_ERR)
 165     {
 166         xerr = xmlnode_new_tag("error");
 167         xmlnode_insert_cdata(xerr,err,-1);
 168         (xs->f)(XSTREAM_ERR, xerr, xs->arg);
 169     }
 170
 171     return xs->status;
 172 }
 173
 174
 175 /* STREAM CREATION UTILITIES */
 176
 177 /* give a standard template xmlnode to work from */
 178 xmlnode xstream_header(char *namespace, char *to, char *from)
 179 {
 180     xmlnode x;
 181     char id[10];
 182
 183     sprintf(id,"%X",(int)time(NULL));
 184
 185     x = xmlnode_new_tag("stream:stream");
 186     xmlnode_put_attrib(x, "xmlns:stream", "http://etherx.jabber.org/streams");
 187     xmlnode_put_attrib(x, "id", id);
 188     if(namespace != NULL)
 189         xmlnode_put_attrib(x, "xmlns", namespace);
 190     if(to != NULL)
 191         xmlnode_put_attrib(x, "to", to);
 192     if(from != NULL)
 193         xmlnode_put_attrib(x, "from", from);
 194
 195     return x;
 196 }
 197
 198 /* trim the xmlnode to only the opening header :) [NO CHILDREN ALLOWED] */
 199 char *xstream_header_char(xmlnode x)
 200 {
 201     spool s;
 202     char *fixr, *head;
 203
 204     if(xmlnode_has_children(x))
 205     {
 206         fprintf(stderr,"Fatal Programming Error: xstream_header_char() was sent a header with children!\n");
 207         return NULL;
 208     }
 209
 210     s = spool_new(xmlnode_pool(x));
 211     spooler(s,"<?xml version='1.0'?>",xmlnode2str(x),s);
 212     head = spool_print(s);
 213     fixr = strstr(head,"/>");
 214     *fixr = '>';
 215     ++fixr;
 216     *fixr = '\0';
 217
 218     return head;
 219 }
 220