| 1 | /* |
| 2 | * This file is part of DisOrder. |
| 3 | * Copyright (C) 2004, 2005, 2007, 2008 Richard Kettlewell |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License as published by |
| 7 | * the Free Software Foundation; either version 2 of the License, or |
| 8 | * (at your option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, but |
| 11 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | * General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program; if not, write to the Free Software |
| 17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 |
| 18 | * USA |
| 19 | */ |
| 20 | /** @file server/cgimain.c |
| 21 | * @brief DisOrder CGI |
| 22 | */ |
| 23 | |
| 24 | #include <config.h> |
| 25 | #include "types.h" |
| 26 | |
| 27 | #include <stdio.h> |
| 28 | #include <errno.h> |
| 29 | #include <stdlib.h> |
| 30 | #include <sys/types.h> |
| 31 | #include <sys/socket.h> |
| 32 | #include <locale.h> |
| 33 | #include <string.h> |
| 34 | #include <stdarg.h> |
| 35 | |
| 36 | #include "client.h" |
| 37 | #include "sink.h" |
| 38 | #include "server-cgi.h" |
| 39 | #include "mem.h" |
| 40 | #include "log.h" |
| 41 | #include "configuration.h" |
| 42 | #include "disorder.h" |
| 43 | #include "api-client.h" |
| 44 | #include "mime.h" |
| 45 | #include "printf.h" |
| 46 | #include "dcgi.h" |
| 47 | #include "url.h" |
| 48 | |
| 49 | #include "macros.h" |
| 50 | #include "macros-disorder.h" |
| 51 | |
| 52 | /** @brief Return true if @p a is better than @p b |
| 53 | * |
| 54 | * NB. We don't bother checking if the path is right, we merely check for the |
| 55 | * longest path. This isn't a security hole: if the browser wants to send us |
| 56 | * bad cookies it's quite capable of sending just the right path anyway. The |
| 57 | * point of choosing the longest path is to avoid using a cookie set by another |
| 58 | * CGI script which shares a path prefix with us, which would allow it to |
| 59 | * maliciously log users out. |
| 60 | * |
| 61 | * Such a script could still "maliciously" log someone in, if it had acquired a |
| 62 | * suitable cookie. But it could just log in directly if it had that, so there |
| 63 | * is no obvious vulnerability here either. |
| 64 | */ |
| 65 | static int better_cookie(const struct cookie *a, const struct cookie *b) { |
| 66 | if(a->path && b->path) |
| 67 | /* If both have a path then the one with the longest path is best */ |
| 68 | return strlen(a->path) > strlen(b->path); |
| 69 | else if(a->path) |
| 70 | /* If only @p a has a path then it is better */ |
| 71 | return 1; |
| 72 | else |
| 73 | /* If neither have a path, or if only @p b has a path, then @p b is |
| 74 | * better */ |
| 75 | return 0; |
| 76 | } |
| 77 | |
| 78 | int main(int argc, char **argv) { |
| 79 | const char *cookie_env, *conf; |
| 80 | dcgi_global g; |
| 81 | dcgi_state s; |
| 82 | cgi_sink output; |
| 83 | int n, best_cookie; |
| 84 | struct cookiedata cd; |
| 85 | |
| 86 | if(argc > 0) |
| 87 | progname = argv[0]; |
| 88 | /* RFC 3875 s8.2 recommends rejecting PATH_INFO if we don't make use of |
| 89 | * it. */ |
| 90 | if(getenv("PATH_INFO")) { |
| 91 | /* TODO it might be nice to link back to the right place... */ |
| 92 | printf("Content-Type: text/html\n"); |
| 93 | printf("Status: 404\n"); |
| 94 | printf("\n"); |
| 95 | printf("<p>Sorry, PATH_INFO not supported.</p>\n"); |
| 96 | exit(0); |
| 97 | } |
| 98 | cgi_parse(); |
| 99 | /* We allow various things to be overridden from the environment. This is |
| 100 | * intended for debugging and is not a documented feature. */ |
| 101 | if((conf = getenv("DISORDER_CONFIG"))) |
| 102 | configfile = xstrdup(conf); |
| 103 | if(getenv("DISORDER_DEBUG")) |
| 104 | debugging = 1; |
| 105 | if(config_read(0)) |
| 106 | exit(EXIT_FAILURE); |
| 107 | /* Figure out our URL. This can still be overridden from the config file if |
| 108 | * necessary but it shouldn't be necessary in ordinary installations. */ |
| 109 | if(!config->url) |
| 110 | config->url = infer_url(); |
| 111 | memset(&g, 0, sizeof g); |
| 112 | memset(&s, 0, sizeof s); |
| 113 | output = sink_stdio("stdout", stdout); |
| 114 | /* See if there's a cookie */ |
| 115 | cookie_env = getenv("HTTP_COOKIE"); |
| 116 | if(cookie_env) { |
| 117 | /* This will be an HTTP header */ |
| 118 | if(!parse_cookie(cookie_env, &cd)) { |
| 119 | /* Pick the best available cookie from all those offered */ |
| 120 | best_cookie = -1; |
| 121 | for(n = 0; n < cd.ncookies; ++n) { |
| 122 | /* Is this the right cookie? */ |
| 123 | if(strcmp(cd.cookies[n].name, "disorder")) |
| 124 | continue; |
| 125 | /* Is it better than anything we've seen so far? */ |
| 126 | if(best_cookie < 0 |
| 127 | || better_cookie(&cd.cookies[n], &cd.cookies[best_cookie])) |
| 128 | best_cookie = n; |
| 129 | } |
| 130 | if(best_cookie != -1) |
| 131 | login_cookie = cd.cookies[best_cookie].value; |
| 132 | } else |
| 133 | error(0, "could not parse cookie field '%s'", cookie_env); |
| 134 | } |
| 135 | /* Register expansions */ |
| 136 | mx_register_builtin(); |
| 137 | register_disorder_expansions(); |
| 138 | /* Update search path. We look in the config directory first and the data |
| 139 | * directory second, so that the latter overrides the former. */ |
| 140 | mx_search_path(pkgconfdir); |
| 141 | mx_search_path(pkgdatadir); |
| 142 | /* Never cache anythging */ |
| 143 | cgi_header(output->sink, "Cache-Control", "no-cache"); |
| 144 | /* Create the initial connection, trying the cookie if we found a suitable |
| 145 | * one. */ |
| 146 | disorder_cgi_login(&s, &output); |
| 147 | /* The main program... */ |
| 148 | disorder_cgi(&output, &s); |
| 149 | /* In practice if a write fails that probably means the web server went away, |
| 150 | * but we log it anyway. */ |
| 151 | if(fclose(stdout) < 0) |
| 152 | fatal(errno, "error closing stdout"); |
| 153 | return 0; |
| 154 | } |
| 155 | |
| 156 | /* |
| 157 | Local Variables: |
| 158 | c-basic-offset:2 |
| 159 | comment-column:40 |
| 160 | fill-column:79 |
| 161 | indent-tabs-mode:nil |
| 162 | End: |
| 163 | */ |