fix for discovery failing on some entities coming before the tag of interest

One of the numerous opportunities to express my gratitude by means of commit
message to Joseph Smarr of Plaxo for spotting it. Thanks, Joseph!

Signed-off-by: Michael Krelin <hacker@klever.net>

1 files changed, 1 insertions, 0 deletions

diff --git a/lib/discovery.cc b/lib/discovery.cc
index c118c80..3b90977 100644
--- a/lib/discovery.cc
+++ b/lib/discovery.cc
@@ -1,582 +1,583 @@
 #include <list>
 #include <opkele/curl.h>
 #include <opkele/expat.h>
 #include <opkele/uris.h>
 #include <opkele/discovery.h>
 #include <opkele/exception.h>
 #include <opkele/util.h>
 #include <opkele/tidy.h>
 #include <opkele/data.h>
 #include <opkele/debug.h>
 
 #include "config.h"
 
 #define XRDS_HEADER "X-XRDS-Location"
 #define CT_HEADER "Content-Type"
 
 namespace opkele {
     using std::list;
     using xrd::XRD_t;
     using xrd::service_t;
 
     /* TODO: the whole discovery thing needs cleanup and optimization due to
      * many changes of concept. */
 
     static const size_t max_html = 16384;
 
     static const struct service_type_t {
 	const char *uri;
 	const char *forceid;
     } op_service_types[] = {
 	{ STURI_OPENID20_OP, IDURI_SELECT20 },
 	{ STURI_OPENID20, 0 },
 	{ STURI_OPENID11, 0 },
 	{ STURI_OPENID10, 0 }
     };
     enum {
 	st_index_1 = 2, st_index_2 = 1
     };
 
 
     static inline bool is_qelement(const XML_Char *n,const char *qen) {
 	return !strcasecmp(n,qen);
     }
     static inline bool is_element(const XML_Char *n,const char *en) {
 	if(!strcasecmp(n,en)) return true;
 	int nl = strlen(n), enl = strlen(en);
 	if( (nl>=(enl+1)) && n[nl-enl-1]=='\t'
 		&& !strcasecmp(&n[nl-enl],en) )
 	    return true;
 	return false;
     }
 
     static long element_priority(const XML_Char **a) {
 	for(;*a;++a)
 	    if(!strcasecmp(*(a++),"priority")) {
 		long rv;
 		return (sscanf(*a,"%ld",&rv)==1)?rv:-1;
 	    }
 	return -1;
     }
     /* TODO: ideally all attributes should be
      * retrieved in one run */
     static const char *element_attr(const XML_Char **a, const char *at) {
 	for(;*a;++a)
 	    if(!strcasecmp(*(a++),at)) {
 		return *a;
 	    }
 	return 0;
     }
 
     class idigger_t : public util::curl_t, public util::expat_t {
 	public:
 	    string xri_proxy;
 
 	    enum {
 		xmode_html = 1, xmode_xrd = 2, xmode_cid = 4,
 		xmode_noredirs = 8
 	    };
 	    int xmode;
 
 	    string xrds_location;
 	    string http_content_type;
 	    service_t html_openid1;
 	    service_t html_openid2;
 	    string cdata_buf;
 	    long status_code;
 	    string status_string;
 
 	    typedef list<string> pt_stack_t;
 	    pt_stack_t pt_stack;
 	    int skipping;
 	    bool parser_choked;
 	    string save_html;
 
 	    XRD_t *xrd;
 	    service_t *xrd_service;
 	    string* cdata;
 
 	    idigger_t()
 		: util::curl_t(easy_init()),
 		util::expat_t(0),
 		xri_proxy(XRI_PROXY_URL) {
 		    CURLcode r;
 		    (r=misc_sets())
 			|| (r=set_write())
 			|| (r=set_header())
 			;
 		    if(r)
 			throw exception_curl(OPKELE_CP_ "failed to set curly options",r);
 		}
 	    ~idigger_t() throw() { }
 
 	    void yadiscover(endpoint_discovery_iterator oi,const string& yurl,const char **types,bool redirs) {
 		idiscovery_t idis;
 		idis.xri_identity = false;
 		discover_at(idis,yurl,xmode_html|xmode_xrd|(redirs?0:xmode_noredirs));
 		if(!xrds_location.empty()) {
 		    idis.clear();
 		    discover_at(idis,xrds_location,xmode_xrd);
 		}
 		idis.normalized_id = idis.canonicalized_id = yurl;
 		service_type_t st;
 		for(st.uri=*types;*types;st.uri=*(++types))
 		    queue_endpoints(oi,idis,&st);
 	    }
 
 	    string discover(endpoint_discovery_iterator& oi,const string& identity) {
 		string rv;
 		idiscovery_t idis;
 		string::size_type fsc = identity.find_first_not_of(data::_whitespace_chars);
 		if(fsc==string::npos)
 		    throw bad_input(OPKELE_CP_ "whitespace-only identity");
 		string::size_type lsc = identity.find_last_not_of(data::_whitespace_chars);
 		assert(lsc!=string::npos);
 		if(!strncasecmp(identity.c_str()+fsc,"xri://",sizeof("xri://")-1))
 		    fsc += sizeof("xri://")-1;
 		if((fsc+1)>=lsc)
 		    throw bad_input(OPKELE_CP_ "not a character of importance in identity");
 		string id(identity,fsc,lsc-fsc+1);
 		idis.clear();
 		if(strchr(data::_iname_leaders,id[0])) {
 		    /* TODO: further normalize xri identity? Like folding case
 		     * or whatever... */
 		    rv = id;
 		    set<string> cids;
 		    for(const struct service_type_t *st=op_service_types;
 			    st<&op_service_types[sizeof(op_service_types)/sizeof(*op_service_types)];++st) {
 			idis.clear();
 			discover_at( idis,
 				xri_proxy + util::url_encode(id)+
 				"?_xrd_t="+util::url_encode(st->uri)+
 				"&_xrd_r=application/xrd%2Bxml"
 				";sep=true;refs=true",
 				xmode_xrd );
 			if(status_code==241) continue;
 			if(status_code!=100)
 			    throw failed_xri_resolution(OPKELE_CP_
 				    "XRI resolution failed with '"+status_string+"' message"
 				    ", while looking for SEP with type '"+st->uri+"'", status_code);
 			if(idis.xrd.canonical_ids.empty())
 			    throw opkele::failed_discovery(OPKELE_CP_ "No CanonicalID for XRI identity found");
 			string cid = idis.xrd.canonical_ids.begin()->second;
 			if(cids.find(cid)==cids.end()) {
 			    cids.insert(cid);
 			    idis.clear();
 			    discover_at( idis,
 				    xri_proxy + util::url_encode(id)+
 				    "?_xrd_t="+util::url_encode(st->uri)+
 				    "&_xrd_r=application/xrd%2Bxml"
 				    ";sep=true;refs=true",
 				    xmode_xrd );
 			    if(status_code==241) continue;
 			    if(status_code!=100)
 				throw failed_xri_resolution(OPKELE_CP_
 					"XRI resolution failed with '"+status_string+"' message"
 					", while looking for SEP with type '"+st->uri+"'"
 					" on canonical id", status_code);
 			}
 			idis.canonicalized_id = cid;
 			idis.normalized_id = rv; idis.xri_identity = true;
 			queue_endpoints(oi,idis,st);
 		    }
 		}else{
 		    idis.xri_identity = false;
 		    if(id.find("://")==string::npos)
 			id.insert(0,"http://");
 		    string::size_type fp = id.find('#');
 		    if(fp!=string::npos) {
 			string::size_type qp = id.find('?');
 			if(qp==string::npos || qp<fp)
 			    id.erase(fp);
 			else if(qp>fp)
 			    id.erase(fp,qp-fp);
 		    }
 		    rv = idis.normalized_id = util::rfc_3986_normalize_uri(id);
 		    discover_at(idis,id,xmode_html|xmode_xrd);
 		    const char * eu = 0;
 		    CURLcode r = easy_getinfo(CURLINFO_EFFECTIVE_URL,&eu);
 		    if(r)
 			throw exception_curl(OPKELE_CP_ "failed to get CURLINFO_EFFECTIVE_URL",r);
 		    string cid = util::strip_uri_fragment_part( idis.canonicalized_id = util::rfc_3986_normalize_uri(eu) );
 		    if(xrds_location.empty()) {
 			if(idis.xrd.empty())
 			    html2xrd(oi,idis);
 			else{
 			    for(const service_type_t *st=op_service_types;
 				    st<&op_service_types[sizeof(op_service_types)/sizeof(*op_service_types)];++st)
 				queue_endpoints(oi,idis,st);
 			}
 		    }else{
 			idis.clear();
 			idis.canonicalized_id = cid;
 			discover_at(idis,xrds_location,xmode_xrd);
 			if(idis.xrd.empty())
 			    html2xrd(oi,idis);
 			else{
 			    for(const service_type_t *st=op_service_types;
 				    st<&op_service_types[sizeof(op_service_types)/sizeof(*op_service_types)];++st)
 				queue_endpoints(oi,idis,st);
 			}
 		    }
 		}
 		return rv;
 	    }
 
 	    void discover_at(idiscovery_t& idis,const string& url,int xm) {
 		CURLcode r = easy_setopt(CURLOPT_MAXREDIRS, (xm&xmode_noredirs)?0:5);
 		if(r)
 		    throw exception_curl(OPKELE_CP_ "failed to set curly maxredirs option");
 		if( (r=easy_setopt(CURLOPT_URL,url.c_str())) )
 		    throw exception_curl(OPKELE_CP_ "failed to set curly urlie",r);
 
 		http_content_type.clear();
 		xmode = xm;
 		prepare_to_parse();
 		if(xmode&xmode_html) {
 		    xrds_location.clear();
 		    save_html.clear();
 		    save_html.reserve(max_html);
 		}
 		xrd = &idis.xrd;
 
 		r = easy_perform();
 		if(r && r!=CURLE_WRITE_ERROR)
 		    throw exception_curl(OPKELE_CP_ "failed to perform curly request",r);
 
 		if(!parser_choked) {
 		    parse(0,0,true);
 		}else if(xmode&xmode_html){
 		    /* TODO: do not bother if we've seen xml */
 		    try {
 			util::tidy_doc_t td = util::tidy_doc_t::create();
 			if(!td)
 			    throw exception_tidy(OPKELE_CP_ "failed to create htmltidy document");
 #ifndef NDEBUG
 			td.opt_set(TidyQuiet,false);
 			td.opt_set(TidyShowWarnings,false);
 #endif /* NDEBUG */
 			td.opt_set(TidyForceOutput,true);
 			td.opt_set(TidyXhtmlOut,true);
 			td.opt_set(TidyDoctypeMode,TidyDoctypeOmit);
 			td.opt_set(TidyMark,false);
+			td.opt_set(TidyNumEntities,true);
 			if(td.parse_string(save_html)<=0)
 			    throw exception_tidy(OPKELE_CP_ "tidy failed to parse document");
 			if(td.clean_and_repair()<=0)
 			    throw exception_tidy(OPKELE_CP_ "tidy failed to clean and repair");
 			util::tidy_buf_t tide;
 			if(td.save_buffer(tide)<=0)
 			    throw exception_tidy(OPKELE_CP_ "tidy failed to save buffer");
 			prepare_to_parse();
 			parse(tide.c_str(),tide.size(),true);
 		    }catch(exception_tidy& et) { }
 		}
 		save_html.clear();
 	    }
 
 	    void prepare_to_parse() {
 		(*(expat_t*)this) = parser_create_ns();
 		set_user_data(); set_element_handler();
 		set_character_data_handler();
 
 		if(xmode&xmode_html) {
 		    html_openid1.clear(); html_openid2.clear();
 		    parser_choked = false;
 		}
 
 		cdata = 0; xrd_service = 0; skipping = 0;
 		pt_stack.clear();
 		status_code = 100; status_string.clear();
 	    }
 
 	    void html2xrd(endpoint_discovery_iterator& oi,idiscovery_t& id) {
 		XRD_t& x = id.xrd;
 		if(!html_openid2.uris.empty()) {
 		    html_openid2.types.insert(STURI_OPENID20);
 		    x.services.add(-1,html_openid2);
 		    queue_endpoints(oi,id,&op_service_types[st_index_2]);
 		}
 		if(!html_openid1.uris.empty()) {
 		    html_openid1.types.insert(STURI_OPENID11);
 		    x.services.add(-1,html_openid1);
 		    queue_endpoints(oi,id,&op_service_types[st_index_1]);
 		}
 	    }
 
 	    size_t write(void *p,size_t s,size_t nm) {
 		/* TODO: limit total size */
 		size_t bytes = s*nm;
 		const char *inbuf = (const char*)p;
 		if(xmode&xmode_html) {
 		    size_t mbts = save_html.capacity()-save_html.size();
 		    size_t bts = 0;
 		    if(mbts>0) {
 			bts = (bytes>mbts)?mbts:bytes;
 			save_html.append(inbuf,bts);
 		    }
 		    if(skipping<0) return bts;
 		}
 		if(skipping<0) return 0;
 		bool rp = parse(inbuf,bytes,false);
 		if(!rp) {
 		    parser_choked = true;
 		    skipping = -1;
 		    if(!(xmode&xmode_html))
 			bytes = 0;
 		}
 		return bytes;
 	    }
 	    size_t header(void *p,size_t s,size_t nm) {
 		size_t bytes = s*nm;
 		const char *h = (const char*)p;
 		const char *colon = (const char*)memchr(p,':',bytes);
 		const char *space = (const char*)memchr(p,' ',bytes);
 		if(space && ( (!colon) || space<colon ) ) {
 		    xrds_location.clear(); http_content_type.clear();
 		}else if(colon) {
 		    const char *hv = ++colon;
 		    size_t hnl = colon-h;
 		    int rb;
 		    for(rb = bytes-hnl-1;rb>0 && isspace(*hv);++hv,--rb);
 		    while(rb>0 && isspace(hv[rb-1])) --rb;
 		    if(rb) {
 			if( (hnl>=sizeof(XRDS_HEADER))
 				&& !strncasecmp(h,XRDS_HEADER":",
 				    sizeof(XRDS_HEADER)) ) {
 			    xrds_location.assign(hv,rb);
 			}else if( (hnl>=sizeof(CT_HEADER))
 				&& !strncasecmp(h,CT_HEADER":",
 				    sizeof(CT_HEADER)) ) {
 			    const char *sc = (const char*)memchr(
 				    hv,';',rb);
 			    http_content_type.assign(hv,sc?(sc-hv):rb);
 			}
 		    }
 		}
 		return curl_t::header(p,s,nm);
 	    }
 
 	    void start_element(const XML_Char *n,const XML_Char **a) {
 		if(skipping<0) return;
 		if(skipping) {
 		    if(xmode&xmode_html)
 			html_start_element(n,a);
 		    ++skipping; return;
 		}
 		if(pt_stack.empty()) {
 		    if(is_qelement(n,NSURI_XRDS "\tXRDS"))
 			return;
 		    if(is_qelement(n,NSURI_XRD "\tXRD")) {
 			assert(xrd);
 			xrd->clear();
 			pt_stack.push_back(n);
 		    }else if(xmode&xmode_html) {
 			html_start_element(n,a);
 		    }else{
 			skipping = -1;
 		    }
 		}else{
 		    int pt_s = pt_stack.size();
 		    if(pt_s==1) {
 			if(is_qelement(n,NSURI_XRD "\tCanonicalID")) {
 			    assert(xrd);
 			    cdata = &(xrd->canonical_ids.add(element_priority(a),string()));
 			}else if(is_qelement(n,NSURI_XRD "\tLocalID")) {
 			    assert(xrd);
 			    cdata = &(xrd->local_ids.add(element_priority(a),string()));
 			}else if(is_qelement(n,NSURI_XRD "\tProviderID")) {
 			    assert(xrd);
 			    cdata = &(xrd->provider_id);
 			}else if(is_qelement(n,NSURI_XRD "\tService")) {
 			    assert(xrd);
 			    xrd_service = &(xrd->services.add(element_priority(a),
 					service_t()));
 			    pt_stack.push_back(n);
 			}else if(is_qelement(n,NSURI_XRD "\tStatus")) {
 			    for(;*a;) {
 				if(!strcasecmp(*(a++),"code")) {
 				    if(sscanf(*(a++),"%ld",&status_code)==1 && status_code!=100) {
 					cdata = &status_string;
 					pt_stack.push_back(n);
 					break;
 				    }
 				}else
 				    ++a;
 			    }
 			}else if(is_qelement(n,NSURI_XRD "\tExpires")) {
 			    assert(xrd);
 			    cdata_buf.clear();
 			    cdata = &cdata_buf;
 			}else if(xmode&xmode_html) {
 			    html_start_element(n,a);
 			}else{
 			    skipping = 1;
 			}
 		    }else if(pt_s==2) {
 			if(is_qelement(pt_stack.back().c_str(), NSURI_XRD "\tService")) {
 			    if(is_qelement(n,NSURI_XRD "\tType")) {
 				assert(xrd); assert(xrd_service);
 				cdata_buf.clear();
 				cdata = &cdata_buf;
 			    }else if(is_qelement(n,NSURI_XRD "\tURI")) {
 				assert(xrd); assert(xrd_service);
 				const char *append = element_attr(a,"append");
 				xrd::uri_t& uri = xrd_service->uris.add(element_priority(a),xrd::uri_t("",append?append:""));
 				cdata = &uri.uri;
 			    }else if(is_qelement(n,NSURI_XRD "\tLocalID")
 				    || is_qelement(n,NSURI_OPENID10 "\tDelegate") ) {
 				assert(xrd); assert(xrd_service);
 				cdata = &(xrd_service->local_ids.add(element_priority(a),string()));
 			    }else if(is_qelement(n,NSURI_XRD "\tProviderID")) {
 				    assert(xrd); assert(xrd_service);
 				    cdata = &(xrd_service->provider_id);
 			    }else{
 				skipping = 1;
 			    }
 			}else
 			    skipping = 1;
 		    }else if(xmode&xmode_html) {
 			html_start_element(n,a);
 		    }else{
 			skipping = 1;
 		    }
 		}
 	    }
 	    void end_element(const XML_Char *n) {
 		if(skipping<0) return;
 		if(skipping) {
 		    --skipping; return;
 		}
 		if(is_qelement(n,NSURI_XRD "\tType")) {
 		    assert(xrd); assert(xrd_service); assert(cdata==&cdata_buf);
 		    xrd_service->types.insert(cdata_buf);
 		}else if(is_qelement(n,NSURI_XRD "\tService")) {
 		    assert(xrd); assert(xrd_service);
 		    assert(!pt_stack.empty());
 		    assert(pt_stack.back()==(NSURI_XRD "\tService"));
 		    pt_stack.pop_back();
 		    xrd_service = 0;
 		}else if(is_qelement(n,NSURI_XRD "\tStatus")) {
 		    assert(xrd);
 		    if(is_qelement(pt_stack.back().c_str(),n)) {
 			assert(cdata==&status_string);
 			pt_stack.pop_back();
 			if(status_code!=100)
 			    skipping = -1;
 		    }
 		}else if(is_qelement(n,NSURI_XRD "\tExpires")) {
 		    assert(xrd);
 		    xrd->expires = util::w3c_to_time(cdata_buf);
 		}else if((xmode&xmode_html) && is_element(n,"head")) {
 		    skipping = -1;
 		}
 		cdata = 0;
 	    }
 	    void character_data(const XML_Char *s,int l) {
 		if(skipping) return;
 		if(cdata) cdata->append(s,l);
 	    }
 
 	    void html_start_element(const XML_Char *n,const XML_Char **a) {
 		if(is_element(n,"meta")) {
 		    bool heq = false;
 		    string l;
 		    for(;*a;a+=2) {
 			if(!( strcasecmp(a[0],"http-equiv")
 				|| strcasecmp(a[1],XRDS_HEADER) ))
 			    heq = true;
 			else if(!strcasecmp(a[0],"content"))
 			    l.assign(a[1]);
 		    }
 		    if(heq)
 			xrds_location = l;
 		}else if(is_element(n,"link")) {
 		    string rels;
 		    string href;
 		    for(;*a;a+=2) {
 			if( !strcasecmp(a[0],"rel") ) {
 			    rels.assign(a[1]);
 			}else if( !strcasecmp(a[0],"href") ) {
 			    const char *ns = a[1];
 			    for(;*ns && isspace(*ns);++ns);
 			    href.assign(ns);
 			    string::size_type lns=href.find_last_not_of(data::_whitespace_chars);
 			    href.erase(lns+1);
 			}
 		    }
 		    for(string::size_type ns=rels.find_first_not_of(data::_whitespace_chars);
 			    ns!=string::npos; ns=rels.find_first_not_of(data::_whitespace_chars,ns)) {
 			string::size_type s = rels.find_first_of(data::_whitespace_chars,ns);
 			string rel;
 			if(s==string::npos) {
 			    rel.assign(rels,ns,string::npos);
 			    ns = string::npos;
 			}else{
 			    rel.assign(rels,ns,s-ns);
 			    ns = s;
 			}
 			if(rel=="openid.server")
 			    html_openid1.uris.add(-1,xrd::uri_t(href));
 			else if(rel=="openid.delegate")
 			    html_openid1.local_ids.add(-1,href);
 			else if(rel=="openid2.provider")
 			    html_openid2.uris.add(-1,xrd::uri_t(href));
 			else if(rel=="openid2.local_id")
 			    html_openid2.local_ids.add(-1,href);
 		    }
 		}else if(is_element(n,"body")) {
 		    skipping = -1;
 		}
 	    }
 
 	    void queue_endpoints(endpoint_discovery_iterator& oi,
 		    const idiscovery_t &id,
 		    const service_type_t *st) {
 		openid_endpoint_t ep;
 		ep.claimed_id = id.canonicalized_id;
 		for(xrd::services_t::const_iterator isvc=id.xrd.services.begin();
 			isvc!=id.xrd.services.end(); ++isvc) {
 		    const xrd::service_t svc = isvc->second;
 		    if(svc.types.find(st->uri)==svc.types.end()) continue;
 		    for(xrd::uris_t::const_iterator iu=svc.uris.begin();iu!=svc.uris.end();++iu) {
 			ep.uri = iu->second.uri;
 			if(id.xri_identity) {
 			    if(iu->second.append=="qxri") {
 				ep.uri += id.normalized_id;
 			    } /* TODO: else handle other append attribute values */
 			}
 			if(st->forceid) {
 			    ep.local_id = ep.claimed_id = st->forceid;
 			    *(oi++) = ep;
 			}else{
 			    if(svc.local_ids.empty()) {
 				ep.local_id = ep.claimed_id;
 				*(oi++) = ep;
 			    }else{
 				for(xrd::local_ids_t::const_iterator ilid=svc.local_ids.begin();
 					ilid!=svc.local_ids.end(); ++ilid) {
 				    ep.local_id = ilid->second;
 				    *(oi++) = ep;
 				}
 			    }
 			}
 		    }
 		}
 	    }
 
     };
 
     string idiscover(endpoint_discovery_iterator oi,const string& identity) {
 	idigger_t idigger;
 	return idigger.discover(oi,identity);
     }
 
     void yadiscover(endpoint_discovery_iterator oi,const string& yurl,const char **types,bool redirs) try {
 	idigger_t idigger;
 	idigger.yadiscover(oi,yurl,types,redirs);
     }catch(exception_curl& ec) {
 	if(redirs || ec._error!=CURLE_TOO_MANY_REDIRECTS)
 	    throw;
     }
 
 }