libdap++  Updated for version 3.8.2
HTTPConnect.cc
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00001 
00002 // -*- mode: c++; c-basic-offset:4 -*-
00003 
00004 // This file is part of libdap, A C++ implementation of the OPeNDAP Data
00005 // Access Protocol.
00006 
00007 // Copyright (c) 2002,2003 OPeNDAP, Inc.
00008 // Author: James Gallagher <jgallagher@opendap.org>
00009 //
00010 // This library is free software; you can redistribute it and/or
00011 // modify it under the terms of the GNU Lesser General Public
00012 // License as published by the Free Software Foundation; either
00013 // version 2.1 of the License, or (at your option) any later version.
00014 //
00015 // This library is distributed in the hope that it will be useful,
00016 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00017 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00018 // Lesser General Public License for more details.
00019 //
00020 // You should have received a copy of the GNU Lesser General Public
00021 // License along with this library; if not, write to the Free Software
00022 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
00023 //
00024 // You can contact OPeNDAP, Inc. at PO Box 112, Saunderstown, RI. 02874-0112.
00025 
00026 
00027 #include "config.h"
00028 
00029 static char rcsid[] not_used =
00030     { "$Id: HTTPConnect.cc 25101 2011-12-19 22:03:29Z jimg $"
00031     };
00032 
00033 #ifdef HAVE_UNISTD_H
00034 #include <unistd.h>
00035 #endif
00036 
00037 #include <sys/stat.h>
00038 
00039 #ifdef WIN32
00040 #include <io.h>
00041 #endif
00042 
00043 #include <string>
00044 #include <vector>
00045 #include <functional>
00046 #include <algorithm>
00047 #include <sstream>
00048 #include <iterator>
00049 #include <cstdlib>
00050 #include <cstring>
00051 
00052 //#define DODS_DEBUG2
00053 //#define HTTP_TRACE
00054 //#define DODS_DEBUG
00055 
00056 #undef USE_GETENV
00057 
00058 
00059 #include "debug.h"
00060 #include "mime_util.h"
00061 #include "GNURegex.h"
00062 #include "HTTPCache.h"
00063 #include "HTTPConnect.h"
00064 #include "RCReader.h"
00065 #include "HTTPResponse.h"
00066 #include "HTTPCacheResponse.h"
00067 
00068 using namespace std;
00069 
00070 namespace libdap {
00071 
00072 // These global variables are not MT-Safe, but I'm leaving them as is because
00073 // they are used only for debugging (set them in a debugger like gdb or ddd).
00074 // They are not static because I think that many debuggers cannot access
00075 // static variables. 08/07/02 jhrg
00076 
00077 // Set this to 1 to turn on libcurl's verbose mode (for debugging).
00078 int www_trace = 0;
00079 
00080 // Keep the temporary files; useful for debugging.
00081 int dods_keep_temps = 0;
00082 
00083 #define CLIENT_ERR_MIN 400
00084 #define CLIENT_ERR_MAX 417
00085 static const char *http_client_errors[CLIENT_ERR_MAX - CLIENT_ERR_MIN +1] =
00086     {
00087         "Bad Request:",
00088         "Unauthorized: Contact the server administrator.",
00089         "Payment Required.",
00090         "Forbidden: Contact the server administrator.",
00091         "Not Found: The data source or server could not be found.\n\
00092         Often this means that the OPeNDAP server is missing or needs attention;\n\
00093         Please contact the server administrator.",
00094         "Method Not Allowed.",
00095         "Not Acceptable.",
00096         "Proxy Authentication Required.",
00097         "Request Time-out.",
00098         "Conflict.",
00099         "Gone:.",
00100         "Length Required.",
00101         "Precondition Failed.",
00102         "Request Entity Too Large.",
00103         "Request URI Too Large.",
00104         "Unsupported Media Type.",
00105         "Requested Range Not Satisfiable.",
00106         "Expectation Failed."
00107     };
00108 
00109 #define SERVER_ERR_MIN 500
00110 #define SERVER_ERR_MAX 505
00111 static const char *http_server_errors[SERVER_ERR_MAX - SERVER_ERR_MIN + 1] =
00112     {
00113         "Internal Server Error.",
00114         "Not Implemented.",
00115         "Bad Gateway.",
00116         "Service Unavailable.",
00117         "Gateway Time-out.",
00118         "HTTP Version Not Supported."
00119     };
00120 
00123 static string
00124 http_status_to_string(int status)
00125 {
00126     if (status >= CLIENT_ERR_MIN && status <= CLIENT_ERR_MAX)
00127         return string(http_client_errors[status - CLIENT_ERR_MIN]);
00128     else if (status >= SERVER_ERR_MIN && status <= SERVER_ERR_MAX)
00129         return string(http_server_errors[status - SERVER_ERR_MIN]);
00130     else
00131         return string("Unknown Error: This indicates a problem with libdap++.\nPlease report this to support@opendap.org.");
00132 }
00133 
00138 class ParseHeader : public unary_function<const string &, void>
00139 {
00140     ObjectType type;  // What type of object is in the stream?
00141     string server;  // Server's version string.
00142     string protocol;            // Server's protocol version.
00143     string location;            // Url returned by server
00144 
00145 public:
00146     ParseHeader() : type(unknown_type), server("dods/0.0"), protocol("2.0")
00147     { }
00148 
00149     void operator()(const string &line)
00150     {
00151         string name, value;
00152         parse_mime_header(line, name, value);
00153         if (name == "content-description") {
00154             DBG2(cerr << name << ": " << value << endl);
00155             type = get_description_type(value);
00156         }
00157         // The second test (== "dods/0.0") tests if xopendap-server has already
00158         // been seen. If so, use that header in preference to the old
00159         // XDODS-Server header. jhrg 2/7/06
00160         else if (name == "xdods-server" && server == "dods/0.0") {
00161             DBG2(cerr << name << ": " << value << endl);
00162             server = value;
00163         }
00164         else if (name == "xopendap-server") {
00165             DBG2(cerr << name << ": " << value << endl);
00166             server = value;
00167         }
00168         else if (name == "xdap") {
00169             DBG2(cerr << name << ": " << value << endl);
00170             protocol = value;
00171         }
00172         else if (server == "dods/0.0" && name == "server") {
00173             DBG2(cerr << name << ": " << value << endl);
00174             server = value;
00175         }
00176         else if (name == "location") {
00177             DBG2(cerr << name << ": " << value << endl);
00178             location = value;
00179         }
00180         else if (type == unknown_type && name == "content-type"
00181                  && line.find("text/html") != string::npos) {
00182             DBG2(cerr << name << ": text/html..." << endl);
00183             type = web_error;
00184         }
00185     }
00186 
00187     ObjectType get_object_type()
00188     {
00189         return type;
00190     }
00191 
00192     string get_server()
00193     {
00194         return server;
00195     }
00196 
00197     string get_protocol()
00198     {
00199         return protocol;
00200     }
00201 
00202     string get_location() {
00203            return location;
00204     }
00205 };
00206 
00223 static size_t
00224 save_raw_http_headers(void *ptr, size_t size, size_t nmemb, void *resp_hdrs)
00225 {
00226     DBG2(cerr << "Inside the header parser." << endl);
00227     vector<string> *hdrs = static_cast<vector<string> * >(resp_hdrs);
00228 
00229     // Grab the header, minus the trailing newline. Or \r\n pair.
00230     string complete_line;
00231     if (nmemb > 1 && *(static_cast<char*>(ptr) + size * (nmemb - 2)) == '\r')
00232         complete_line.assign(static_cast<char *>(ptr), size * (nmemb - 2));
00233     else
00234         complete_line.assign(static_cast<char *>(ptr), size * (nmemb - 1));
00235 
00236     // Store all non-empty headers that are not HTTP status codes
00237     if (complete_line != "" && complete_line.find("HTTP") == string::npos) {
00238         DBG(cerr << "Header line: " << complete_line << endl);
00239         hdrs->push_back(complete_line);
00240     }
00241 
00242     return size * nmemb;
00243 }
00244 
00246 static int
00247 curl_debug(CURL *, curl_infotype info, char *msg, size_t size, void  *)
00248 {
00249     string message(msg, size);
00250 
00251     switch (info) {
00252     case CURLINFO_TEXT:
00253         cerr << "Text: " << message; break;
00254     case CURLINFO_HEADER_IN:
00255         cerr << "Header in: " << message; break;
00256     case CURLINFO_HEADER_OUT:
00257         cerr << "Header out: " << message; break;
00258     case CURLINFO_DATA_IN:
00259         cerr << "Data in: " << message; break;
00260     case CURLINFO_DATA_OUT:
00261         cerr << "Data out: " << message; break;
00262     case CURLINFO_END:
00263         cerr << "End: " << message; break;
00264 #ifdef CURLINFO_SSL_DATA_IN
00265     case CURLINFO_SSL_DATA_IN:
00266         cerr << "SSL Data in: " << message; break;
00267 #endif
00268 #ifdef CURLINFO_SSL_DATA_OUT
00269     case CURLINFO_SSL_DATA_OUT:
00270         cerr << "SSL Data out: " << message; break;
00271 #endif
00272     default:
00273         cerr << "Curl info: " << message; break;
00274     }
00275     return 0;
00276 }
00277 
00281 void
00282 HTTPConnect::www_lib_init()
00283 {
00284     d_curl = curl_easy_init();
00285     if (!d_curl)
00286         throw InternalErr(__FILE__, __LINE__, "Could not initialize libcurl.");
00287 
00288     // Now set options that will remain constant for the duration of this
00289     // CURL object.
00290 
00291     // Set the proxy host.
00292     if (!d_rcr->get_proxy_server_host().empty()) {
00293         DBG(cerr << "Setting up a proxy server." << endl);
00294         DBG(cerr << "Proxy host: " << d_rcr->get_proxy_server_host()
00295             << endl);
00296         DBG(cerr << "Proxy port: " << d_rcr->get_proxy_server_port()
00297             << endl);
00298         DBG(cerr << "Proxy pwd : " << d_rcr->get_proxy_server_userpw()
00299             << endl);
00300         curl_easy_setopt(d_curl, CURLOPT_PROXY,
00301                          d_rcr->get_proxy_server_host().c_str());
00302         curl_easy_setopt(d_curl, CURLOPT_PROXYPORT,
00303                          d_rcr->get_proxy_server_port());
00304 
00305         // As of 4/21/08 only NTLM, Digest and Basic work.
00306 #ifdef CURLOPT_PROXYAUTH
00307         curl_easy_setopt(d_curl, CURLOPT_PROXYAUTH, (long)CURLAUTH_ANY);
00308 #endif
00309 
00310         // Password might not be required. 06/21/04 jhrg
00311         if (!d_rcr->get_proxy_server_userpw().empty())
00312             curl_easy_setopt(d_curl, CURLOPT_PROXYUSERPWD,
00313                              d_rcr->get_proxy_server_userpw().c_str());
00314     }
00315 
00316     curl_easy_setopt(d_curl, CURLOPT_ERRORBUFFER, d_error_buffer);
00317     // We have to set FailOnError to false for any of the non-Basic
00318     // authentication schemes to work. 07/28/03 jhrg
00319     curl_easy_setopt(d_curl, CURLOPT_FAILONERROR, 0);
00320 
00321     // This means libcurl will use Basic, Digest, GSS Negotiate, or NTLM,
00322     // choosing the the 'safest' one supported by the server.
00323     // This requires curl 7.10.6 which is still in pre-release. 07/25/03 jhrg
00324     curl_easy_setopt(d_curl, CURLOPT_HTTPAUTH, (long)CURLAUTH_ANY);
00325 
00326     curl_easy_setopt(d_curl, CURLOPT_NOPROGRESS, 1);
00327     curl_easy_setopt(d_curl, CURLOPT_NOSIGNAL, 1);
00328     curl_easy_setopt(d_curl, CURLOPT_HEADERFUNCTION, save_raw_http_headers);
00329     // In read_url a call to CURLOPT_WRITEHEADER is used to set the fourth
00330     // param of save_raw_http_headers to a vector<string> object.
00331 
00332     // Follow 302 (redirect) responses
00333     curl_easy_setopt(d_curl, CURLOPT_FOLLOWLOCATION, 1);
00334     curl_easy_setopt(d_curl, CURLOPT_MAXREDIRS, 5);
00335 
00336     // If the user turns off SSL validation...
00337     if (!d_rcr->get_validate_ssl() == 0) {
00338         curl_easy_setopt(d_curl, CURLOPT_SSL_VERIFYPEER, 0);
00339         curl_easy_setopt(d_curl, CURLOPT_SSL_VERIFYHOST, 0);
00340     }
00341 
00342     // Look to see if cookies are turned on in the .dodsrc file. If so,
00343     // activate here. We honor 'session cookies' (cookies without an
00344     // expiration date) here so that session-base SSO systems will work as
00345     // expected.
00346     if (!d_cookie_jar.empty()) {
00347         DBG(cerr << "Setting the cookie jar to: " << d_cookie_jar << endl);
00348         curl_easy_setopt(d_curl, CURLOPT_COOKIEJAR, d_cookie_jar.c_str());
00349         curl_easy_setopt(d_curl, CURLOPT_COOKIESESSION, 1);
00350     }
00351 
00352     if (www_trace) {
00353         cerr << "Curl version: " << curl_version() << endl;
00354         curl_easy_setopt(d_curl, CURLOPT_VERBOSE, 1);
00355         curl_easy_setopt(d_curl, CURLOPT_DEBUGFUNCTION, curl_debug);
00356     }
00357 }
00358 
00362 class BuildHeaders : public unary_function<const string &, void>
00363 {
00364     struct curl_slist *d_cl;
00365 
00366 public:
00367     BuildHeaders() : d_cl(0)
00368     {}
00369 
00370     void operator()(const string &header)
00371     {
00372         DBG(cerr << "Adding '" << header.c_str() << "' to the header list."
00373             << endl);
00374         d_cl = curl_slist_append(d_cl, header.c_str());
00375     }
00376 
00377     struct curl_slist *get_headers()
00378     {
00379         return d_cl;
00380     }
00381 };
00382 
00397 long
00398 HTTPConnect::read_url(const string &url, FILE *stream,
00399                       vector<string> *resp_hdrs,
00400                       const vector<string> *headers)
00401 {
00402     curl_easy_setopt(d_curl, CURLOPT_URL, url.c_str());
00403 
00404 #ifdef WIN32
00405     //  See the curl documentation for CURLOPT_FILE (aka CURLOPT_WRITEDATA)
00406     //  and the CURLOPT_WRITEFUNCTION option.  Quote: "If you are using libcurl as
00407     //  a win32 DLL, you MUST use the CURLOPT_WRITEFUNCTION option if you set the
00408     //  CURLOPT_WRITEDATA option or you will experience crashes".  At the root of
00409     //  this issue is that one should not pass a FILE * to a windows DLL.  Close
00410     //  inspection of libcurl yields that their default write function when using
00411     //  the CURLOPT_WRITEDATA is just "fwrite".
00412     curl_easy_setopt(d_curl, CURLOPT_FILE, stream);
00413     curl_easy_setopt(d_curl, CURLOPT_WRITEFUNCTION, &fwrite);
00414 #else
00415     curl_easy_setopt(d_curl, CURLOPT_FILE, stream);
00416 #endif
00417 
00418     DBG(copy(d_request_headers.begin(), d_request_headers.end(),
00419              ostream_iterator<string>(cerr, "\n")));
00420 
00421     BuildHeaders req_hdrs;
00422     req_hdrs = for_each(d_request_headers.begin(), d_request_headers.end(),
00423                         req_hdrs);
00424     if (headers)
00425         req_hdrs = for_each(headers->begin(), headers->end(), req_hdrs);
00426     curl_easy_setopt(d_curl, CURLOPT_HTTPHEADER, req_hdrs.get_headers());
00427 
00428     // Turn off the proxy for this URL?
00429     bool temporary_proxy = false;
00430     if ((temporary_proxy = url_uses_no_proxy_for(url))) {
00431         DBG(cerr << "Suppress proxy for url: " << url << endl);
00432         curl_easy_setopt(d_curl, CURLOPT_PROXY, 0);
00433     }
00434 
00435     string::size_type at_sign = url.find('@');
00436     // Assume username:password present *and* assume it's an HTTP URL; it *is*
00437     // HTTPConnect, after all. 7 is position after "http://"; the second arg
00438     // to substr() is the sub string length.
00439     if (at_sign != url.npos)
00440         d_upstring = url.substr(7, at_sign - 7);
00441 
00442     if (!d_upstring.empty())
00443         curl_easy_setopt(d_curl, CURLOPT_USERPWD, d_upstring.c_str());
00444 
00445     // Pass save_raw_http_headers() a pointer to the vector<string> where the
00446     // response headers may be stored. Callers can use the resp_hdrs
00447     // value/result parameter to get the raw response header information .
00448     curl_easy_setopt(d_curl, CURLOPT_WRITEHEADER, resp_hdrs);
00449 
00450     CURLcode res = curl_easy_perform(d_curl);
00451 
00452     // Free the header list and null the value in d_curl.
00453     curl_slist_free_all(req_hdrs.get_headers());
00454     curl_easy_setopt(d_curl, CURLOPT_HTTPHEADER, 0);
00455 
00456     // Reset the proxy?
00457     if (temporary_proxy && !d_rcr->get_proxy_server_host().empty())
00458         curl_easy_setopt(d_curl, CURLOPT_PROXY,
00459                          d_rcr->get_proxy_server_host().c_str());
00460 
00461     if (res != 0)
00462         throw Error(d_error_buffer);
00463 
00464     long status;
00465     res = curl_easy_getinfo(d_curl, CURLINFO_HTTP_CODE, &status);
00466     if (res != 0)
00467         throw Error(d_error_buffer);
00468 
00469     return status;
00470 }
00471 
00475 bool
00476 HTTPConnect::url_uses_proxy_for(const string &url) throw()
00477 {
00478     if (d_rcr->is_proxy_for_used()) {
00479         Regex host_regex(d_rcr->get_proxy_for_regexp().c_str());
00480         int index = 0, matchlen;
00481         return host_regex.search(url.c_str(), url.size(), matchlen, index) != -1;
00482     }
00483 
00484     return false;
00485 }
00486 
00490 bool
00491 HTTPConnect::url_uses_no_proxy_for(const string &url) throw()
00492 {
00493     return d_rcr->is_no_proxy_for_used()
00494            && url.find(d_rcr->get_no_proxy_for_host()) != string::npos;
00495 }
00496 
00497 // Public methods. Mostly...
00498 
00505 HTTPConnect::HTTPConnect(RCReader *rcr) : d_username(""), d_password(""),
00506                                           d_cookie_jar(""),
00507                                           d_dap_client_protocol_major(2),
00508                                           d_dap_client_protocol_minor(0)
00509 
00510 {
00511     d_accept_deflate = rcr->get_deflate();
00512     d_rcr = rcr;
00513 
00514     // Load in the default headers to send with a request. The empty Pragma
00515     // headers overrides libcurl's default Pragma: no-cache header (which
00516     // will disable caching by Squid, et c.). The User-Agent header helps
00517     // make server logs more readable. 05/05/03 jhrg
00518     d_request_headers.push_back(string("Pragma:"));
00519     string user_agent = string("User-Agent: ") + string(CNAME)
00520                         + string("/") + string(CVER);
00521     d_request_headers.push_back(user_agent);
00522     if (d_accept_deflate)
00523         d_request_headers.push_back(string("Accept-Encoding: deflate, gzip, compress"));
00524 
00525     // HTTPCache::instance returns a valid ptr or 0.
00526     if (d_rcr->get_use_cache())
00527         d_http_cache = HTTPCache::instance(d_rcr->get_dods_cache_root(),
00528                                            true);
00529     else
00530         d_http_cache = 0;
00531 
00532     DBG2(cerr << "Cache object created (" << hex << d_http_cache << dec
00533          << ")" << endl);
00534 
00535     if (d_http_cache) {
00536         d_http_cache->set_cache_enabled(d_rcr->get_use_cache());
00537         d_http_cache->set_expire_ignored(d_rcr->get_ignore_expires() != 0);
00538         d_http_cache->set_max_size(d_rcr->get_max_cache_size());
00539         d_http_cache->set_max_entry_size(d_rcr->get_max_cached_obj());
00540         d_http_cache->set_default_expiration(d_rcr->get_default_expires());
00541         d_http_cache->set_always_validate(d_rcr->get_always_validate() != 0);
00542     }
00543 
00544     d_cookie_jar = rcr->get_cookie_jar();
00545 
00546     www_lib_init();  // This may throw either Error or InternalErr
00547 }
00548 
00549 HTTPConnect::~HTTPConnect()
00550 {
00551     DBG2(cerr << "Entering the HTTPConnect dtor" << endl);
00552 
00553     curl_easy_cleanup(d_curl);
00554 
00555     DBG2(cerr << "Leaving the HTTPConnect dtor" << endl);
00556 }
00557 
00570 HTTPResponse *
00571 HTTPConnect::fetch_url(const string &url)
00572 {
00573 #ifdef HTTP_TRACE
00574     cout << "GET " << url << " HTTP/1.0" << endl;
00575 #endif
00576 
00577     HTTPResponse *stream;
00578 
00579     if (d_http_cache && d_http_cache->is_cache_enabled()) {
00580         stream = caching_fetch_url(url);
00581     }
00582     else {
00583         stream = plain_fetch_url(url);
00584     }
00585 
00586 #ifdef HTTP_TRACE
00587     stringstream ss;
00588     ss << "HTTP/1.0 " << stream->get_status() << " -" << endl;
00589     for (size_t i = 0; i < stream->get_headers()->size(); i++) {
00590         ss << stream->get_headers()->at(i) << endl;
00591     }
00592     cout << ss.str();
00593 #endif
00594 
00595     ParseHeader parser;
00596 
00597     parser = for_each(stream->get_headers()->begin(),
00598                       stream->get_headers()->end(), ParseHeader());
00599 
00600 #ifdef HTTP_TRACE
00601     cout << endl << endl;
00602 #endif
00603 
00604     // handle redirection case (2007-04-27, gaffigan@sfos.uaf.edu)
00605     if (parser.get_location() != "" &&
00606             url.substr(0,url.find("?",0)).compare(parser.get_location().substr(0,url.find("?",0))) != 0) {
00607         delete stream;
00608         return fetch_url(parser.get_location());
00609     }
00610 
00611     stream->set_type(parser.get_object_type());
00612     stream->set_version(parser.get_server());
00613     stream->set_protocol(parser.get_protocol());
00614 
00615     return stream;
00616 }
00617 
00618 // Look around for a reasonable place to put a temporary file. Check first
00619 // the value of the TMPDIR env var. If that does not yeild a path that's
00620 // writable (as defined by access(..., W_OK|R_OK)) then look at P_tmpdir (as
00621 // defined in stdio.h. If both come up empty, then use `./'.
00622 
00623 // Change this to a version that either returns a string or an open file
00624 // descriptor. Use information from https://buildsecurityin.us-cert.gov/
00625 // (see open()) to make it more secure. Ideal solution: get deserialize()
00626 // methods to read from a stream returned by libcurl, not from a temporary
00627 // file. 9/21/07 jhrg Updated to use strings, so other misc changes. 3/22/11
00628 static string
00629 get_tempfile_template(const string &file_template)
00630 {
00631     string c;
00632 
00633     // Windows has one idea of the standard name(s) for a temporary files dir
00634 #ifdef WIN32
00635     // white list for a WIN32 directory
00636     Regex directory("[-a-zA-Z0-9_:\\]*");
00637 
00638     // If we're OK to use getenv(), try it.
00639 #ifdef USE_GETENV
00640     c = getenv("TEMP");
00641     if (c && directory.match(c.c_str(), c.length()) && (access(c.c_str(), 6) == 0))
00642         goto valid_temp_directory;
00643 
00644     c= getenv("TMP");
00645     if (c && directory.match(c.c_str(), c.length()) && (access(c.c_str(), 6) == 0))
00646         goto valid_temp_directory;
00647 #endif // USE_GETENV
00648 
00649     // The windows default
00650     c = "c:\tmp";
00651     if (c && directory.match(c.c_str(), c.length()) && (access(c.c_str(), 6) == 0))
00652         goto valid_temp_directory;
00653 
00654 #else   // Unix/Linux/OSX has another...
00655     // white list for a directory
00656     Regex directory("[-a-zA-Z0-9_/]*");
00657 #ifdef USE_GETENV
00658     c = getenv("TMPDIR");
00659     if (directory.match(c.c_str(), c.length()) && (access(c.c_str(), W_OK | R_OK) == 0))
00660         goto valid_temp_directory;
00661 #endif // USE_GETENV
00662 
00663     // Unix defines this sometimes - if present, use it.
00664 #ifdef P_tmpdir
00665     if (access(P_tmpdir, W_OK | R_OK) == 0) {
00666         c = P_tmpdir;
00667         goto valid_temp_directory;
00668     }
00669 #endif
00670 
00671     // The Unix default
00672     c = "/tmp";
00673     if (directory.match(c.c_str(), c.length()) && (access(c.c_str(), W_OK | R_OK) == 0))
00674         goto valid_temp_directory;
00675 
00676 #endif  // WIN32
00677 
00678     // If we found nothing useful, use the current directory
00679     c = ".";
00680 
00681 valid_temp_directory:
00682 
00683 #ifdef WIN32
00684     c += "\\" + file_template;
00685 #else
00686     c += "/" + file_template;
00687 #endif
00688 
00689     return c;
00690 }
00691 
00710 string
00711 get_temp_file(FILE *&stream) throw(InternalErr)
00712 {
00713     string dods_temp = get_tempfile_template((string)"dodsXXXXXX");
00714 
00715     vector<char> pathname(dods_temp.length() + 1);
00716 
00717     strncpy(&pathname[0], dods_temp.c_str(), dods_temp.length());
00718 
00719     DBG(cerr << "pathanme: " << &pathname[0] << " (" << dods_temp.length() + 1 << ")" << endl);
00720 
00721     // Open truncated for update. NB: mkstemp() returns a file descriptor.
00722 #if defined(WIN32) || defined(TEST_WIN32_TEMPS)
00723     stream = fopen(_mktemp(&pathname[0]), "w+b");
00724 #else
00725     // Make sure that temp files are accessible only by the owner.
00726     umask(077);
00727     stream = fdopen(mkstemp(&pathname[0]), "w+");
00728 #endif
00729 
00730     if (!stream) {
00731         throw InternalErr(__FILE__, __LINE__,
00732                 "Failed to open a temporary file for the data values ("
00733                 + dods_temp + ")");
00734     }
00735 
00736     dods_temp = &pathname[0];
00737     return dods_temp;
00738 }
00739 
00741 void
00742 close_temp(FILE *s, const string &name)
00743 {
00744     int res = fclose(s);
00745     if (res)
00746         throw InternalErr(__FILE__, __LINE__, "!FAIL! " + long_to_string(res));
00747 
00748     res = unlink(name.c_str());
00749     if (res != 0)
00750         throw InternalErr(__FILE__, __LINE__, "!FAIL! " + long_to_string(res));
00751 }
00752 
00774 HTTPResponse *
00775 HTTPConnect::caching_fetch_url(const string &url)
00776 {
00777     DBG(cerr << "Is this URL (" << url << ") in the cache?... ");
00778 
00779     vector<string> *headers = new vector<string>;
00780     string file_name;
00781     FILE *s = d_http_cache->get_cached_response(url, *headers, file_name);
00782     if (!s) {
00783         // url not in cache; get it and cache it
00784         DBGN(cerr << "no; getting response and caching." << endl);
00785         delete headers; headers = 0;
00786         time_t now = time(0);
00787         HTTPResponse *rs = plain_fetch_url(url);
00788         d_http_cache->cache_response(url, now, *(rs->get_headers()), rs->get_stream());
00789 
00790         return rs;
00791     }
00792     else { // url in cache
00793         DBGN(cerr << "yes... ");
00794 
00795         if (d_http_cache->is_url_valid(url)) { // url in cache and valid
00796             DBGN(cerr << "and it's valid; using cached response." << endl);
00797             HTTPCacheResponse *crs = new HTTPCacheResponse(s, 200, headers, file_name, d_http_cache);
00798             return crs;
00799         }
00800         else { // url in cache but not valid; validate
00801             DBGN(cerr << "but it's not valid; validating... ");
00802 
00803             d_http_cache->release_cached_response(s); // This closes 's'
00804             headers->clear();
00805             vector<string> cond_hdrs = d_http_cache->get_conditional_request_headers(url);
00806             FILE *body = 0;
00807             string dods_temp = get_temp_file(body);
00808             time_t now = time(0); // When was the request made (now).
00809             long http_status;
00810 
00811             try {
00812                 http_status = read_url(url, body, /*resp_hdrs*/headers, &cond_hdrs);
00813                 rewind(body);
00814             }
00815             catch (Error &e) {
00816                 close_temp(body, dods_temp);
00817                 delete headers;
00818                 throw ;
00819             }
00820 
00821             switch (http_status) {
00822                 case 200: { // New headers and new body
00823                     DBGN(cerr << "read a new response; caching." << endl);
00824 
00825                     d_http_cache->cache_response(url, now, /* *resp_hdrs*/*headers, body);
00826                     HTTPResponse *rs = new HTTPResponse(body, http_status, /*resp_hdrs*/headers, dods_temp);
00827 
00828                     return rs;
00829                 }
00830 
00831                 case 304: { // Just new headers, use cached body
00832                     DBGN(cerr << "cached response valid; updating." << endl);
00833 
00834                     close_temp(body, dods_temp);
00835                     d_http_cache->update_response(url, now, /* *resp_hdrs*/ *headers);
00836                     string file_name;
00837                     FILE *hs = d_http_cache->get_cached_response(url, *headers, file_name);
00838                     HTTPCacheResponse *crs = new HTTPCacheResponse(hs, 304, headers, file_name, d_http_cache);
00839                     return crs;
00840                 }
00841 
00842                 default: { // Oops.
00843                     close_temp(body, dods_temp);
00844                     if (http_status >= 400) {
00845                         delete headers; headers = 0;
00846                         string msg = "Error while reading the URL: ";
00847                         msg += url;
00848                         msg
00849                         += ".\nThe OPeNDAP server returned the following message:\n";
00850                         msg += http_status_to_string(http_status);
00851                         throw Error(msg);
00852                     }
00853                     else {
00854                         delete headers; headers = 0;
00855                         throw InternalErr(__FILE__, __LINE__,
00856                                 "Bad response from the HTTP server: " + long_to_string(http_status));
00857                     }
00858                 }
00859             }
00860         }
00861     }
00862 
00863     throw InternalErr(__FILE__, __LINE__, "Should never get here");
00864 }
00865 
00877 HTTPResponse *
00878 HTTPConnect::plain_fetch_url(const string &url)
00879 {
00880     DBG(cerr << "Getting URL: " << url << endl);
00881     FILE *stream = 0;
00882     string dods_temp = get_temp_file(stream);
00883     vector<string> *resp_hdrs = new vector<string>;
00884 
00885     int status = -1;
00886     try {
00887         status = read_url(url, stream, resp_hdrs); // Throws Error.
00888         if (status >= 400) {
00889                 delete resp_hdrs;
00890             string msg = "Error while reading the URL: ";
00891             msg += url;
00892             msg += ".\nThe OPeNDAP server returned the following message:\n";
00893             msg += http_status_to_string(status);
00894             throw Error(msg);
00895         }
00896     }
00897 
00898     catch (Error &e) {
00899         delete resp_hdrs;
00900         close_temp(stream, dods_temp);
00901         throw;
00902     }
00903 
00904     rewind(stream);
00905 
00906     return new HTTPResponse(stream, status, resp_hdrs, dods_temp);
00907 }
00908 
00920 void
00921 HTTPConnect::set_accept_deflate(bool deflate)
00922 {
00923     d_accept_deflate = deflate;
00924 
00925     if (d_accept_deflate) {
00926         if (find(d_request_headers.begin(), d_request_headers.end(),
00927                  "Accept-Encoding: deflate, gzip, compress") == d_request_headers.end())
00928             d_request_headers.push_back(string("Accept-Encoding: deflate, gzip, compress"));
00929         DBG(copy(d_request_headers.begin(), d_request_headers.end(),
00930                  ostream_iterator<string>(cerr, "\n")));
00931     }
00932     else {
00933         vector<string>::iterator i;
00934         i = remove_if(d_request_headers.begin(), d_request_headers.end(),
00935                       bind2nd(equal_to<string>(),
00936                               string("Accept-Encoding: deflate, gzip, compress")));
00937         d_request_headers.erase(i, d_request_headers.end());
00938     }
00939 }
00940 
00942 class HeaderMatch : public unary_function<const string &, bool> {
00943     const string &d_header;
00944     public:
00945         HeaderMatch(const string &header) : d_header(header) {}
00946         bool operator()(const string &arg) { return arg.find(d_header) == 0; }
00947 };
00948 
00957 void
00958 HTTPConnect::set_xdap_protocol(int major, int minor)
00959 {
00960     // Look for, and remove if one exists, an XDAP-Accept header
00961     vector<string>::iterator i;
00962     i = find_if(d_request_headers.begin(), d_request_headers.end(),
00963                 HeaderMatch("XDAP-Accept:"));
00964     if (i != d_request_headers.end())
00965         d_request_headers.erase(i);
00966 
00967     // Record and add the new header value
00968     d_dap_client_protocol_major = major;
00969     d_dap_client_protocol_minor = minor;
00970     ostringstream xdap_accept;
00971     xdap_accept << "XDAP-Accept: " << major << "." << minor;
00972 
00973     d_request_headers.push_back(xdap_accept.str());
00974 
00975     DBG(copy(d_request_headers.begin(), d_request_headers.end(),
00976              ostream_iterator<string>(cerr, "\n")));
00977 }
00978 
00994 void
00995 HTTPConnect::set_credentials(const string &u, const string &p)
00996 {
00997     if (u.empty())
00998         return;
00999 
01000     // Store the credentials locally.
01001     d_username = u;
01002     d_password = p;
01003 
01004     d_upstring = u + ":" + p;
01005 }
01006 
01007 } // namespace libdap