X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/disorder/blobdiff_plain/b64c2805b65538c7ad9a8b373e00060bbe453b8c..5a7df0480aa9e958e612b2da9addd589d404fd95:/server/cgimain.c diff --git a/server/cgimain.c b/server/cgimain.c index 5acf9ea..77764c0 100644 --- a/server/cgimain.c +++ b/server/cgimain.c @@ -1,6 +1,6 @@ /* * This file is part of DisOrder. - * Copyright (C) 2004, 2005, 2007 Richard Kettlewell + * Copyright (C) 2004, 2005, 2007, 2008 Richard Kettlewell * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -17,6 +17,9 @@ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 * USA */ +/** @file server/cgimain.c + * @brief DisOrder CGI + */ #include #include "types.h" @@ -32,8 +35,7 @@ #include "client.h" #include "sink.h" -#include "cgi.h" -#include "dcgi.h" +#include "server-cgi.h" #include "mem.h" #include "log.h" #include "configuration.h" @@ -41,42 +43,36 @@ #include "api-client.h" #include "mime.h" #include "printf.h" +#include "dcgi.h" +#include "url.h" + +#include "macros.h" +#include "macros-disorder.h" -/** @brief Infer the base URL for the web interface if it's not set +/** @brief Return true if @p a is better than @p b * - * See RFC 3875. + * NB. We don't bother checking if the path is right, we merely check for the + * longest path. This isn't a security hole: if the browser wants to send us + * bad cookies it's quite capable of sending just the right path anyway. The + * point of choosing the longest path is to avoid using a cookie set by another + * CGI script which shares a path prefix with us, which would allow it to + * maliciously log users out. + * + * Such a script could still "maliciously" log someone in, if it had acquired a + * suitable cookie. But it could just log in directly if it had that, so there + * is no obvious vulnerability here either. */ -static void infer_url(void) { - if(!config->url) { - const char *scheme = "http", *server, *script, *e; - int port; - - /* Figure out the server. 'MUST' be set and we don't cope if it - * is not. */ - if(!(server = getenv("SERVER_NAME"))) - fatal(0, "SERVER_NAME is not set"); - server = xstrdup(server); - - /* Figure out the port. 'MUST' be set but we cope if it is not. */ - if((e = getenv("SERVER_PORT"))) - port = atoi(e); - else - port = 80; - - /* Figure out path to ourselves */ - if(!(script = getenv("SCRIPT_NAME"))) - fatal(0, "SCRIPT_NAME is not set"); - if(script[0] != '/') - fatal(0, "SCRIPT_NAME does not start with a '/'"); - script = xstrdup(script); - - if(port == 80) - byte_xasprintf(&config->url, "%s://%s%s", - scheme, server, script); - else - byte_xasprintf(&config->url, "%s://%s:%d%s", - scheme, server, port, script); - } +static int better_cookie(const struct cookie *a, const struct cookie *b) { + if(a->path && b->path) + /* If both have a path then the one with the longest path is best */ + return strlen(a->path) > strlen(b->path); + else if(a->path) + /* If only @p a has a path then it is better */ + return 1; + else + /* If neither have a path, or if only @p b has a path, then @p b is + * better */ + return 0; } int main(int argc, char **argv) { @@ -84,41 +80,76 @@ int main(int argc, char **argv) { dcgi_global g; dcgi_state s; cgi_sink output; - int n; + int n, best_cookie; struct cookiedata cd; - if(argc > 0) progname = argv[0]; + if(argc > 0) + progname = argv[0]; + /* RFC 3875 s8.2 recommends rejecting PATH_INFO if we don't make use of + * it. */ + if(getenv("PATH_INFO")) { + /* TODO it might be nice to link back to the right place... */ + printf("Content-Type: text/html\n"); + printf("Status: 404\n"); + printf("\n"); + printf("

Sorry, PATH_INFO not supported.

\n"); + exit(0); + } cgi_parse(); - if((conf = getenv("DISORDER_CONFIG"))) configfile = xstrdup(conf); - if(getenv("DISORDER_DEBUG")) debugging = 1; - if(config_read(0)) exit(EXIT_FAILURE); - infer_url(); + /* We allow various things to be overridden from the environment. This is + * intended for debugging and is not a documented feature. */ + if((conf = getenv("DISORDER_CONFIG"))) + configfile = xstrdup(conf); + if(getenv("DISORDER_DEBUG")) + debugging = 1; + if(config_read(0)) + exit(EXIT_FAILURE); + /* Figure out our URL. This can still be overridden from the config file if + * necessary but it shouldn't be necessary in ordinary installations. */ + if(!config->url) + config->url = infer_url(); memset(&g, 0, sizeof g); memset(&s, 0, sizeof s); - s.g = &g; - g.client = disorder_get_client(); - output.quote = 1; - output.sink = sink_stdio("stdout", stdout); + output = sink_stdio("stdout", stdout); /* See if there's a cookie */ cookie_env = getenv("HTTP_COOKIE"); if(cookie_env) { /* This will be an HTTP header */ if(!parse_cookie(cookie_env, &cd)) { - for(n = 0; n < cd.ncookies - && strcmp(cd.cookies[n].name, "disorder"); ++n) - ; - if(n < cd.ncookies) - login_cookie = cd.cookies[n].value; - } - } - /* Log in with the cookie if possible otherwise as guest */ - if(disorder_connect_cookie(g.client, login_cookie)) { - disorder_cgi_error(&output, &s, "connect"); - return 0; + /* Pick the best available cookie from all those offered */ + best_cookie = -1; + for(n = 0; n < cd.ncookies; ++n) { + /* Is this the right cookie? */ + if(strcmp(cd.cookies[n].name, "disorder")) + continue; + /* Is it better than anything we've seen so far? */ + if(best_cookie < 0 + || better_cookie(&cd.cookies[n], &cd.cookies[best_cookie])) + best_cookie = n; + } + if(best_cookie != -1) + login_cookie = cd.cookies[best_cookie].value; + } else + error(0, "could not parse cookie field '%s'", cookie_env); } - /* TODO RFC 3875 s8.2 recommendations e.g. concerning PATH_INFO */ + /* Register expansions */ + mx_register_builtin(); + register_disorder_expansions(); + /* Update search path. We look in the config directory first and the data + * directory second, so that the latter overrides the former. */ + mx_search_path(pkgconfdir); + mx_search_path(pkgdatadir); + /* Never cache anythging */ + cgi_header(output->sink, "Cache-Control", "no-cache"); + /* Create the initial connection, trying the cookie if we found a suitable + * one. */ + disorder_cgi_login(&s, &output); + /* The main program... */ disorder_cgi(&output, &s); - if(fclose(stdout) < 0) fatal(errno, "error closing stdout"); + /* In practice if a write fails that probably means the web server went away, + * but we log it anyway. */ + if(fclose(stdout) < 0) + fatal(errno, "error closing stdout"); return 0; } @@ -126,5 +157,7 @@ int main(int argc, char **argv) { Local Variables: c-basic-offset:2 comment-column:40 +fill-column:79 +indent-tabs-mode:nil End: */