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cgi-bozo.c revision 1.20.2.1
      1 /*	$NetBSD: cgi-bozo.c,v 1.20.2.1 2014/07/09 09:42:39 msaitoh Exp $	*/
      2 
      3 /*	$eterna: cgi-bozo.c,v 1.40 2011/11/18 09:21:15 mrg Exp $	*/
      4 
      5 /*
      6  * Copyright (c) 1997-2014 Matthew R. Green
      7  * All rights reserved.
      8  *
      9  * Redistribution and use in source and binary forms, with or without
     10  * modification, are permitted provided that the following conditions
     11  * are met:
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  * 2. Redistributions in binary form must reproduce the above copyright
     15  *    notice, this list of conditions and the following disclaimer and
     16  *    dedication in the documentation and/or other materials provided
     17  *    with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     24  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     25  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     26  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     27  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  *
     31  */
     32 
     33 /* this code implements CGI/1.2 for bozohttpd */
     34 
     35 #ifndef NO_CGIBIN_SUPPORT
     36 
     37 #include <sys/param.h>
     38 #include <sys/socket.h>
     39 
     40 #include <ctype.h>
     41 #include <errno.h>
     42 #include <paths.h>
     43 #include <signal.h>
     44 #include <stdlib.h>
     45 #include <string.h>
     46 #include <syslog.h>
     47 #include <unistd.h>
     48 
     49 #include <netinet/in.h>
     50 
     51 #include "bozohttpd.h"
     52 
     53 #define CGIBIN_PREFIX		"cgi-bin/"
     54 #define CGIBIN_PREFIX_LEN	(sizeof(CGIBIN_PREFIX)-1)
     55 
     56 #ifndef USE_ARG
     57 #define USE_ARG(x)	/*LINTED*/(void)&(x)
     58 #endif
     59 
     60 /*
     61  * given the file name, return a CGI interpreter
     62  */
     63 static const char *
     64 content_cgihandler(bozohttpd_t *httpd, bozo_httpreq_t *request,
     65 		const char *file)
     66 {
     67 	bozo_content_map_t	*map;
     68 
     69 	USE_ARG(request);
     70 	debug((httpd, DEBUG_FAT, "content_cgihandler: trying file %s", file));
     71 	map = bozo_match_content_map(httpd, file, 0);
     72 	if (map)
     73 		return map->cgihandler;
     74 	return NULL;
     75 }
     76 
     77 static int
     78 parse_header(bozohttpd_t *httpd, const char *str, ssize_t len, char **hdr_str,
     79 		char **hdr_val)
     80 {
     81 	char	*name, *value;
     82 
     83 	/* if the string passed is zero-length bail out */
     84 	if (*str == '\0')
     85 		return -1;
     86 
     87 	value = bozostrdup(httpd, str);
     88 
     89 	/* locate the ':' separator in the header/value */
     90 	name = bozostrnsep(&value, ":", &len);
     91 
     92 	if (NULL == name || -1 == len) {
     93 		free(name);
     94 		return -1;
     95 	}
     96 
     97 	/* skip leading space/tab */
     98 	while (*value == ' ' || *value == '\t')
     99 		len--, value++;
    100 
    101 	*hdr_str = name;
    102 	*hdr_val = value;
    103 
    104 	return 0;
    105 }
    106 
    107 /*
    108  * handle parsing a CGI header output, transposing a Status: header
    109  * into the HTTP reply (ie, instead of "200 OK").
    110  */
    111 static void
    112 finish_cgi_output(bozohttpd_t *httpd, bozo_httpreq_t *request, int in, int nph)
    113 {
    114 	char	buf[BOZO_WRSZ];
    115 	char	*str;
    116 	ssize_t	len;
    117 	ssize_t rbytes;
    118 	SIMPLEQ_HEAD(, bozoheaders)	headers;
    119 	bozoheaders_t *hdr, *nhdr;
    120 	int	write_header, nheaders = 0;
    121 
    122 	/* much of this code is like bozo_read_request()'s header loop. */
    123 	SIMPLEQ_INIT(&headers);
    124 	write_header = nph == 0;
    125 	/* was read(2) here - XXX - agc */
    126 	while (nph == 0 &&
    127 		(str = bozodgetln(httpd, in, &len, bozo_read)) != NULL) {
    128 		char	*hdr_name, *hdr_value;
    129 
    130 		if (parse_header(httpd, str, len, &hdr_name, &hdr_value))
    131 			break;
    132 
    133 		/*
    134 		 * The CGI 1.{1,2} spec both say that if the cgi program
    135 		 * returns a `Status:' header field then the server MUST
    136 		 * return it in the response.  If the cgi program does
    137 		 * not return any `Status:' header then the server should
    138 		 * respond with 200 OK.
    139 		 * XXX The CGI 1.1 and 1.2 specification differ slightly on
    140 		 * this in that v1.2 says that the script MUST NOT return a
    141 		 * `Status:' header if it is returning a `Location:' header.
    142 		 * For compatibility we are going with the CGI 1.1 behavior.
    143 		 */
    144 		if (strcasecmp(hdr_name, "status") == 0) {
    145 			debug((httpd, DEBUG_OBESE,
    146 				"bozo_process_cgi:  writing HTTP header "
    147 				"from status %s ..", hdr_value));
    148 			bozo_printf(httpd, "%s %s\r\n", request->hr_proto,
    149 					hdr_value);
    150 			bozo_flush(httpd, stdout);
    151 			write_header = 0;
    152 			free(hdr_name);
    153 			break;
    154 		}
    155 
    156 		hdr = bozomalloc(httpd, sizeof *hdr);
    157 		hdr->h_header = hdr_name;
    158 		hdr->h_value = hdr_value;
    159 		SIMPLEQ_INSERT_TAIL(&headers, hdr, h_next);
    160 		nheaders++;
    161 	}
    162 
    163 	if (write_header) {
    164 		debug((httpd, DEBUG_OBESE,
    165 			"bozo_process_cgi:  writing HTTP header .."));
    166 		bozo_printf(httpd,
    167 			"%s 200 OK\r\n", request->hr_proto);
    168 		bozo_flush(httpd, stdout);
    169 	}
    170 
    171 	if (nheaders) {
    172 		debug((httpd, DEBUG_OBESE,
    173 			"bozo_process_cgi:  writing delayed HTTP headers .."));
    174 		SIMPLEQ_FOREACH_SAFE(hdr, &headers, h_next, nhdr) {
    175 			bozo_printf(httpd, "%s: %s\r\n", hdr->h_header,
    176 					hdr->h_value);
    177 			free(hdr->h_header);
    178 			free(hdr);
    179 		}
    180 		bozo_printf(httpd, "\r\n");
    181 		bozo_flush(httpd, stdout);
    182 	}
    183 
    184 	/* XXX we should have some goo that times us out
    185 	 */
    186 	while ((rbytes = read(in, buf, sizeof buf)) > 0) {
    187 		ssize_t wbytes;
    188 		char *bp = buf;
    189 
    190 		while (rbytes) {
    191 			wbytes = bozo_write(httpd, STDOUT_FILENO, buf,
    192 						(size_t)rbytes);
    193 			if (wbytes > 0) {
    194 				rbytes -= wbytes;
    195 				bp += wbytes;
    196 			} else
    197 				bozo_err(httpd, 1,
    198 					"cgi output write failed: %s",
    199 					strerror(errno));
    200 		}
    201 	}
    202 }
    203 
    204 static void
    205 append_index_html(bozohttpd_t *httpd, char **url)
    206 {
    207 	*url = bozorealloc(httpd, *url,
    208 			strlen(*url) + strlen(httpd->index_html) + 1);
    209 	strcat(*url, httpd->index_html);
    210 	debug((httpd, DEBUG_NORMAL,
    211 		"append_index_html: url adjusted to `%s'", *url));
    212 }
    213 
    214 void
    215 bozo_cgi_setbin(bozohttpd_t *httpd, const char *path)
    216 {
    217 	httpd->cgibin = strdup(path);
    218 	debug((httpd, DEBUG_OBESE, "cgibin (cgi-bin directory) is %s",
    219 		httpd->cgibin));
    220 }
    221 
    222 /* help build up the environ pointer */
    223 void
    224 bozo_setenv(bozohttpd_t *httpd, const char *env, const char *val,
    225 		char **envp)
    226 {
    227 	char *s1 = bozomalloc(httpd, strlen(env) + strlen(val) + 2);
    228 
    229 	strcpy(s1, env);
    230 	strcat(s1, "=");
    231 	strcat(s1, val);
    232 	debug((httpd, DEBUG_OBESE, "bozo_setenv: %s", s1));
    233 	*envp = s1;
    234 }
    235 
    236 /*
    237  * Checks if the request has asked for a cgi-bin.  Should only be called if
    238  * cgibin is set.  If it starts CGIBIN_PREFIX or has a ncontent handler,
    239  * process the cgi, otherwise just return.  Returns 0 if it did not handle
    240  * the request.
    241  */
    242 int
    243 bozo_process_cgi(bozo_httpreq_t *request)
    244 {
    245 	bozohttpd_t *httpd = request->hr_httpd;
    246 	char	buf[BOZO_WRSZ];
    247 	char	date[40];
    248 	bozoheaders_t *headp;
    249 	const char *type, *clen, *info, *cgihandler;
    250 	char	*query, *s, *t, *path, *env, *command, *file, *url;
    251 	char	**envp, **curenvp, *argv[4];
    252 	char	*uri;
    253 	size_t	len;
    254 	ssize_t rbytes;
    255 	pid_t	pid;
    256 	int	envpsize, ix, nph;
    257 	int	sv[2];
    258 
    259 	if (!httpd->cgibin && !httpd->process_cgi)
    260 		return 0;
    261 
    262 	if (request->hr_oldfile && strcmp(request->hr_oldfile, "/") != 0)
    263 		uri = request->hr_oldfile;
    264 	else
    265 		uri = request->hr_file;
    266 
    267 	if (uri[0] == '/')
    268 		file = bozostrdup(httpd, uri);
    269 	else
    270 		asprintf(&file, "/%s", uri);
    271 	if (file == NULL)
    272 		return 0;
    273 
    274 	if (request->hr_query && strlen(request->hr_query))
    275 		query = bozostrdup(httpd, request->hr_query);
    276 	else
    277 		query = NULL;
    278 
    279 	asprintf(&url, "%s%s%s", file, query ? "?" : "", query ? query : "");
    280 	if (url == NULL)
    281 		goto out;
    282 	debug((httpd, DEBUG_NORMAL, "bozo_process_cgi: url `%s'", url));
    283 
    284 	path = NULL;
    285 	envp = NULL;
    286 	cgihandler = NULL;
    287 	command = NULL;
    288 	info = NULL;
    289 
    290 	len = strlen(url);
    291 
    292 	if (bozo_auth_check(request, url + 1))
    293 		goto out;
    294 
    295 	if (!httpd->cgibin ||
    296 	    strncmp(url + 1, CGIBIN_PREFIX, CGIBIN_PREFIX_LEN) != 0) {
    297 		cgihandler = content_cgihandler(httpd, request, file + 1);
    298 		if (cgihandler == NULL) {
    299 			debug((httpd, DEBUG_FAT,
    300 				"bozo_process_cgi: no handler, returning"));
    301 			goto out;
    302 		}
    303 		if (len == 0 || file[len - 1] == '/')
    304 			append_index_html(httpd, &file);
    305 		debug((httpd, DEBUG_NORMAL, "bozo_process_cgi: cgihandler `%s'",
    306 		    cgihandler));
    307 	} else if (len - 1 == CGIBIN_PREFIX_LEN)	/* url is "/cgi-bin/" */
    308 		append_index_html(httpd, &file);
    309 
    310 	ix = 0;
    311 	if (cgihandler) {
    312 		command = file + 1;
    313 		path = bozostrdup(httpd, cgihandler);
    314 		argv[ix++] = path;
    315 			/* argv[] = [ path, command, query, NULL ] */
    316 	} else {
    317 		command = file + CGIBIN_PREFIX_LEN + 1;
    318 		if ((s = strchr(command, '/')) != NULL) {
    319 			info = bozostrdup(httpd, s);
    320 			*s = '\0';
    321 		}
    322 		path = bozomalloc(httpd,
    323 				strlen(httpd->cgibin) + 1 + strlen(command) + 1);
    324 		strcpy(path, httpd->cgibin);
    325 		strcat(path, "/");
    326 		strcat(path, command);
    327 			/* argv[] = [ command, query, NULL ] */
    328 	}
    329 	argv[ix++] = command;
    330 	argv[ix++] = query;
    331 	argv[ix++] = NULL;
    332 
    333 	nph = strncmp(command, "nph-", 4) == 0;
    334 
    335 	type = request->hr_content_type;
    336 	clen = request->hr_content_length;
    337 
    338 	envpsize = 13 + request->hr_nheaders +
    339 	    (info && *info ? 1 : 0) +
    340 	    (query && *query ? 1 : 0) +
    341 	    (type && *type ? 1 : 0) +
    342 	    (clen && *clen ? 1 : 0) +
    343 	    (request->hr_remotehost && *request->hr_remotehost ? 1 : 0) +
    344 	    (request->hr_remoteaddr && *request->hr_remoteaddr ? 1 : 0) +
    345 	    bozo_auth_cgi_count(request) +
    346 	    (request->hr_serverport && *request->hr_serverport ? 1 : 0);
    347 
    348 	debug((httpd, DEBUG_FAT,
    349 		"bozo_process_cgi: path `%s', cmd `%s', info `%s', "
    350 		"query `%s', nph `%d', envpsize `%d'",
    351 		path, command, strornull(info),
    352 		strornull(query), nph, envpsize));
    353 
    354 	envp = bozomalloc(httpd, sizeof(*envp) * envpsize);
    355 	for (ix = 0; ix < envpsize; ix++)
    356 		envp[ix] = NULL;
    357 	curenvp = envp;
    358 
    359 	SIMPLEQ_FOREACH(headp, &request->hr_headers, h_next) {
    360 		const char *s2;
    361 		env = bozomalloc(httpd, 6 + strlen(headp->h_header) + 1 +
    362 		    strlen(headp->h_value));
    363 
    364 		t = env;
    365 		strcpy(t, "HTTP_");
    366 		t += strlen(t);
    367 		for (s2 = headp->h_header; *s2; t++, s2++)
    368 			if (islower((u_int)*s2))
    369 				*t = toupper((u_int)*s2);
    370 			else if (*s2 == '-')
    371 				*t = '_';
    372 			else
    373 				*t = *s2;
    374 		*t = '\0';
    375 		debug((httpd, DEBUG_OBESE, "setting header %s as %s = %s",
    376 		    headp->h_header, env, headp->h_value));
    377 		bozo_setenv(httpd, env, headp->h_value, curenvp++);
    378 		free(env);
    379 	}
    380 
    381 #ifndef _PATH_DEFPATH
    382 #define _PATH_DEFPATH "/usr/bin:/bin"
    383 #endif
    384 
    385 	bozo_setenv(httpd, "PATH", _PATH_DEFPATH, curenvp++);
    386 	bozo_setenv(httpd, "IFS", " \t\n", curenvp++);
    387 	bozo_setenv(httpd, "SERVER_NAME", BOZOHOST(httpd,request), curenvp++);
    388 	bozo_setenv(httpd, "GATEWAY_INTERFACE", "CGI/1.1", curenvp++);
    389 	bozo_setenv(httpd, "SERVER_PROTOCOL", request->hr_proto, curenvp++);
    390 	bozo_setenv(httpd, "REQUEST_METHOD", request->hr_methodstr, curenvp++);
    391 	bozo_setenv(httpd, "SCRIPT_NAME", file, curenvp++);
    392 	bozo_setenv(httpd, "SCRIPT_FILENAME", file + 1, curenvp++);
    393 	bozo_setenv(httpd, "SERVER_SOFTWARE", httpd->server_software,
    394 			curenvp++);
    395 	bozo_setenv(httpd, "REQUEST_URI", uri, curenvp++);
    396 	bozo_setenv(httpd, "DATE_GMT", bozo_http_date(date, sizeof(date)),
    397 			curenvp++);
    398 	if (query && *query)
    399 		bozo_setenv(httpd, "QUERY_STRING", query, curenvp++);
    400 	if (info && *info)
    401 		bozo_setenv(httpd, "PATH_INFO", info, curenvp++);
    402 	if (type && *type)
    403 		bozo_setenv(httpd, "CONTENT_TYPE", type, curenvp++);
    404 	if (clen && *clen)
    405 		bozo_setenv(httpd, "CONTENT_LENGTH", clen, curenvp++);
    406 	if (request->hr_serverport && *request->hr_serverport)
    407 		bozo_setenv(httpd, "SERVER_PORT", request->hr_serverport,
    408 				curenvp++);
    409 	if (request->hr_remotehost && *request->hr_remotehost)
    410 		bozo_setenv(httpd, "REMOTE_HOST", request->hr_remotehost,
    411 				curenvp++);
    412 	if (request->hr_remoteaddr && *request->hr_remoteaddr)
    413 		bozo_setenv(httpd, "REMOTE_ADDR", request->hr_remoteaddr,
    414 				curenvp++);
    415 	/*
    416 	 * XXX Apache does this when invoking content handlers, and PHP
    417 	 * XXX 5.3 requires it as a "security" measure.
    418 	 */
    419 	if (cgihandler)
    420 		bozo_setenv(httpd, "REDIRECT_STATUS", "200", curenvp++);
    421 	bozo_auth_cgi_setenv(request, &curenvp);
    422 
    423 	free(file);
    424 	free(url);
    425 
    426 	debug((httpd, DEBUG_FAT, "bozo_process_cgi: going exec %s, %s %s %s",
    427 	    path, argv[0], strornull(argv[1]), strornull(argv[2])));
    428 
    429 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, sv) == -1)
    430 		bozo_err(httpd, 1, "child socketpair failed: %s",
    431 				strerror(errno));
    432 
    433 	/*
    434 	 * We create 2 procs: one to become the CGI, one read from
    435 	 * the CGI and output to the network, and this parent will
    436 	 * continue reading from the network and writing to the
    437 	 * CGI procsss.
    438 	 */
    439 	switch (fork()) {
    440 	case -1: /* eep, failure */
    441 		bozo_err(httpd, 1, "child fork failed: %s", strerror(errno));
    442 		/*NOTREACHED*/
    443 	case 0:
    444 		close(sv[0]);
    445 		dup2(sv[1], STDIN_FILENO);
    446 		dup2(sv[1], STDOUT_FILENO);
    447 		close(2);
    448 		close(sv[1]);
    449 		closelog();
    450 		bozo_daemon_closefds(httpd);
    451 
    452 		if (-1 == execve(path, argv, envp))
    453 			bozo_err(httpd, 1, "child exec failed: %s: %s",
    454 			      path, strerror(errno));
    455 		/* NOT REACHED */
    456 		bozo_err(httpd, 1, "child execve returned?!");
    457 	}
    458 
    459 	close(sv[1]);
    460 
    461 	/* parent: read from stdin (bozo_read()) write to sv[0] */
    462 	/* child: read from sv[0] (bozo_write()) write to stdout */
    463 	pid = fork();
    464 	if (pid == -1)
    465 		bozo_err(httpd, 1, "io child fork failed: %s", strerror(errno));
    466 	else if (pid == 0) {
    467 		/* child reader/writer */
    468 		close(STDIN_FILENO);
    469 		finish_cgi_output(httpd, request, sv[0], nph);
    470 		/* if we're done output, our parent is useless... */
    471 		kill(getppid(), SIGKILL);
    472 		debug((httpd, DEBUG_FAT, "done processing cgi output"));
    473 		_exit(0);
    474 	}
    475 	close(STDOUT_FILENO);
    476 
    477 	/* XXX we should have some goo that times us out
    478 	 */
    479 	while ((rbytes = bozo_read(httpd, STDIN_FILENO, buf, sizeof buf)) > 0) {
    480 		ssize_t wbytes;
    481 		char *bp = buf;
    482 
    483 		while (rbytes) {
    484 			wbytes = write(sv[0], buf, (size_t)rbytes);
    485 			if (wbytes > 0) {
    486 				rbytes -= wbytes;
    487 				bp += wbytes;
    488 			} else
    489 				bozo_err(httpd, 1, "write failed: %s",
    490 					strerror(errno));
    491 		}
    492 	}
    493 	debug((httpd, DEBUG_FAT, "done processing cgi input"));
    494 	exit(0);
    495 
    496  out:
    497 	free(query);
    498 	free(file);
    499 	free(url);
    500 	return 0;
    501 }
    502 
    503 #ifndef NO_DYNAMIC_CONTENT
    504 /* cgi maps are simple ".postfix /path/to/prog" */
    505 void
    506 bozo_add_content_map_cgi(bozohttpd_t *httpd, const char *arg, const char *cgihandler)
    507 {
    508 	bozo_content_map_t *map;
    509 
    510 	debug((httpd, DEBUG_NORMAL, "bozo_add_content_map_cgi: name %s cgi %s",
    511 		arg, cgihandler));
    512 
    513 	httpd->process_cgi = 1;
    514 
    515 	map = bozo_get_content_map(httpd, arg);
    516 	map->name = arg;
    517 	map->namelen = strlen(map->name);
    518 	map->type = map->encoding = map->encoding11 = NULL;
    519 	map->cgihandler = cgihandler;
    520 }
    521 #endif /* NO_DYNAMIC_CONTENT */
    522 
    523 #endif /* NO_CGIBIN_SUPPORT */
    524