source: trunk/server/source3/web/cgi.c@ 596

Last change on this file since 596 was 596, checked in by Herwig Bauernfeind, 14 years ago

Samba 3.5: Update trunk to 3.5.8
File size: 17.9 KB
Line 
1/*
2 some simple CGI helper routines
3 Copyright (C) Andrew Tridgell 1997-1998
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 3 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,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU 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, see <http://www.gnu.org/licenses/>.
17*/
18
19
20#include "includes.h"
21#include "web/swat_proto.h"
22
23#define MAX_VARIABLES 10000
24
25/* set the expiry on fixed pages */
26#define EXPIRY_TIME (60*60*24*7)
27
28#ifdef DEBUG_COMMENTS
29extern void print_title(char *fmt, ...);
30#endif
31
32struct cgi_var {
33 char *name;
34 char *value;
35};
36
37static struct cgi_var variables[MAX_VARIABLES];
38static int num_variables;
39static int content_length;
40static int request_post;
41static char *query_string;
42static const char *baseurl;
43static char *pathinfo;
44static char *C_user;
45static bool inetd_server;
46static bool got_request;
47
48static char *grab_line(FILE *f, int *cl)
49{
50 char *ret = NULL;
51 int i = 0;
52 int len = 0;
53
54 while ((*cl)) {
55 int c;
56
57 if (i == len) {
58 char *ret2;
59 if (len == 0) len = 1024;
60 else len *= 2;
61 ret2 = (char *)SMB_REALLOC_KEEP_OLD_ON_ERROR(ret, len);
62 if (!ret2) return ret;
63 ret = ret2;
64 }
65
66 c = fgetc(f);
67 (*cl)--;
68
69 if (c == EOF) {
70 (*cl) = 0;
71 break;
72 }
73
74 if (c == '\r') continue;
75
76 if (strchr_m("\n&", c)) break;
77
78 ret[i++] = c;
79
80 }
81
82 if (ret) {
83 ret[i] = 0;
84 }
85 return ret;
86}
87
88/**
89 URL encoded strings can have a '+', which should be replaced with a space
90
91 (This was in rfc1738_unescape(), but that broke the squid helper)
92**/
93
94static void plus_to_space_unescape(char *buf)
95{
96 char *p=buf;
97
98 while ((p=strchr_m(p,'+')))
99 *p = ' ';
100}
101
102/***************************************************************************
103 load all the variables passed to the CGI program. May have multiple variables
104 with the same name and the same or different values. Takes a file parameter
105 for simulating CGI invocation eg loading saved preferences.
106 ***************************************************************************/
107void cgi_load_variables(void)
108{
109 static char *line;
110 char *p, *s, *tok;
111 int len, i;
112 FILE *f = stdin;
113
114#ifdef DEBUG_COMMENTS
115 char dummy[100]="";
116 print_title(dummy);
117 d_printf("<!== Start dump in cgi_load_variables() %s ==>\n",__FILE__);
118#endif
119
120 if (!content_length) {
121 p = getenv("CONTENT_LENGTH");
122 len = p?atoi(p):0;
123 } else {
124 len = content_length;
125 }
126
127
128 if (len > 0 &&
129 (request_post ||
130 ((s=getenv("REQUEST_METHOD")) &&
131 strequal(s,"POST")))) {
132 while (len && (line=grab_line(f, &len))) {
133 p = strchr_m(line,'=');
134 if (!p) continue;
135
136 *p = 0;
137
138 variables[num_variables].name = SMB_STRDUP(line);
139 variables[num_variables].value = SMB_STRDUP(p+1);
140
141 SAFE_FREE(line);
142
143 if (!variables[num_variables].name ||
144 !variables[num_variables].value)
145 continue;
146
147 plus_to_space_unescape(variables[num_variables].value);
148 rfc1738_unescape(variables[num_variables].value);
149 plus_to_space_unescape(variables[num_variables].name);
150 rfc1738_unescape(variables[num_variables].name);
151
152#ifdef DEBUG_COMMENTS
153 printf("<!== POST var %s has value \"%s\" ==>\n",
154 variables[num_variables].name,
155 variables[num_variables].value);
156#endif
157
158 num_variables++;
159 if (num_variables == MAX_VARIABLES) break;
160 }
161 }
162
163 fclose(stdin);
164 open("/dev/null", O_RDWR);
165
166 if ((s=query_string) || (s=getenv("QUERY_STRING"))) {
167 char *saveptr;
168 for (tok=strtok_r(s, "&;", &saveptr); tok;
169 tok=strtok_r(NULL, "&;", &saveptr)) {
170 p = strchr_m(tok,'=');
171 if (!p) continue;
172
173 *p = 0;
174
175 variables[num_variables].name = SMB_STRDUP(tok);
176 variables[num_variables].value = SMB_STRDUP(p+1);
177
178 if (!variables[num_variables].name ||
179 !variables[num_variables].value)
180 continue;
181
182 plus_to_space_unescape(variables[num_variables].value);
183 rfc1738_unescape(variables[num_variables].value);
184 plus_to_space_unescape(variables[num_variables].name);
185 rfc1738_unescape(variables[num_variables].name);
186
187#ifdef DEBUG_COMMENTS
188 printf("<!== Commandline var %s has value \"%s\" ==>\n",
189 variables[num_variables].name,
190 variables[num_variables].value);
191#endif
192 num_variables++;
193 if (num_variables == MAX_VARIABLES) break;
194 }
195
196 }
197#ifdef DEBUG_COMMENTS
198 printf("<!== End dump in cgi_load_variables() ==>\n");
199#endif
200
201 /* variables from the client are in UTF-8 - convert them
202 to our internal unix charset before use */
203 for (i=0;i<num_variables;i++) {
204 TALLOC_CTX *frame = talloc_stackframe();
205 char *dest = NULL;
206 size_t dest_len;
207
208 convert_string_talloc(frame, CH_UTF8, CH_UNIX,
209 variables[i].name, strlen(variables[i].name),
210 &dest, &dest_len, True);
211 SAFE_FREE(variables[i].name);
212 variables[i].name = SMB_STRDUP(dest ? dest : "");
213
214 dest = NULL;
215 convert_string_talloc(frame, CH_UTF8, CH_UNIX,
216 variables[i].value, strlen(variables[i].value),
217 &dest, &dest_len, True);
218 SAFE_FREE(variables[i].value);
219 variables[i].value = SMB_STRDUP(dest ? dest : "");
220 TALLOC_FREE(frame);
221 }
222}
223
224
225/***************************************************************************
226 find a variable passed via CGI
227 Doesn't quite do what you think in the case of POST text variables, because
228 if they exist they might have a value of "" or even " ", depending on the
229 browser. Also doesn't allow for variables[] containing multiple variables
230 with the same name and the same or different values.
231 ***************************************************************************/
232
233const char *cgi_variable(const char *name)
234{
235 int i;
236
237 for (i=0;i<num_variables;i++)
238 if (strcmp(variables[i].name, name) == 0)
239 return variables[i].value;
240 return NULL;
241}
242
243/***************************************************************************
244 Version of the above that can't return a NULL pointer.
245***************************************************************************/
246
247const char *cgi_variable_nonull(const char *name)
248{
249 const char *var = cgi_variable(name);
250 if (var) {
251 return var;
252 } else {
253 return "";
254 }
255}
256
257/***************************************************************************
258tell a browser about a fatal error in the http processing
259 ***************************************************************************/
260static void cgi_setup_error(const char *err, const char *header, const char *info)
261{
262 if (!got_request) {
263 /* damn browsers don't like getting cut off before they give a request */
264 char line[1024];
265 while (fgets(line, sizeof(line)-1, stdin)) {
266 if (strnequal(line,"GET ", 4) ||
267 strnequal(line,"POST ", 5) ||
268 strnequal(line,"PUT ", 4)) {
269 break;
270 }
271 }
272 }
273
274 d_printf("HTTP/1.0 %s\r\n%sConnection: close\r\nContent-Type: text/html\r\n\r\n<HTML><HEAD><TITLE>%s</TITLE></HEAD><BODY><H1>%s</H1>%s<p></BODY></HTML>\r\n\r\n", err, header, err, err, info);
275 fclose(stdin);
276 fclose(stdout);
277 exit(0);
278}
279
280
281/***************************************************************************
282tell a browser about a fatal authentication error
283 ***************************************************************************/
284static void cgi_auth_error(void)
285{
286 if (inetd_server) {
287 cgi_setup_error("401 Authorization Required",
288 "WWW-Authenticate: Basic realm=\"SWAT\"\r\n",
289 "You must be authenticated to use this service");
290 } else {
291 printf("Content-Type: text/html\r\n");
292
293 printf("\r\n<HTML><HEAD><TITLE>SWAT</TITLE></HEAD>\n");
294 printf("<BODY><H1>Installation Error</H1>\n");
295 printf("SWAT must be installed via inetd. It cannot be run as a CGI script<p>\n");
296 printf("</BODY></HTML>\r\n");
297 }
298 exit(0);
299}
300
301/***************************************************************************
302authenticate when we are running as a CGI
303 ***************************************************************************/
304static void cgi_web_auth(void)
305{
306 const char *user = getenv("REMOTE_USER");
307 struct passwd *pwd;
308 const char *head = "Content-Type: text/html\r\n\r\n<HTML><BODY><H1>SWAT installation Error</H1>\n";
309 const char *tail = "</BODY></HTML>\r\n";
310
311 if (!user) {
312 printf("%sREMOTE_USER not set. Not authenticated by web server.<br>%s\n",
313 head, tail);
314 exit(0);
315 }
316
317#ifndef __OS2__
318 pwd = Get_Pwnam_alloc(talloc_autofree_context(), user);
319
320 if (!pwd) {
321 printf("%sCannot find user %s<br>%s\n", head, user, tail);
322 exit(0);
323 }
324
325 setuid(0);
326 setuid(pwd->pw_uid);
327 if (geteuid() != pwd->pw_uid || getuid() != pwd->pw_uid) {
328 printf("%sFailed to become user %s - uid=%d/%d<br>%s\n",
329 head, user, (int)geteuid(), (int)getuid(), tail);
330 exit(0);
331 }
332 TALLOC_FREE(pwd);
333#endif
334}
335
336
337/***************************************************************************
338handle a http authentication line
339 ***************************************************************************/
340static bool cgi_handle_authorization(char *line)
341{
342 char *p;
343 fstring user, user_pass;
344 struct passwd *pass = NULL;
345
346 if (!strnequal(line,"Basic ", 6)) {
347 goto err;
348 }
349 line += 6;
350 while (line[0] == ' ') line++;
351 base64_decode_inplace(line);
352 if (!(p=strchr_m(line,':'))) {
353 /*
354 * Always give the same error so a cracker
355 * cannot tell why we fail.
356 */
357 goto err;
358 }
359 *p = 0;
360
361 convert_string(CH_UTF8, CH_UNIX,
362 line, -1,
363 user, sizeof(user), True);
364
365 convert_string(CH_UTF8, CH_UNIX,
366 p+1, -1,
367 user_pass, sizeof(user_pass), True);
368
369 /*
370 * Try and get the user from the UNIX password file.
371 */
372
373 pass = Get_Pwnam_alloc(talloc_autofree_context(), user);
374
375 /*
376 * Validate the password they have given.
377 */
378
379 if NT_STATUS_IS_OK(pass_check(pass, user, user_pass,
380 strlen(user_pass), NULL, False)) {
381
382 if (pass) {
383 /*
384 * Password was ok.
385 */
386
387 if ( initgroups(pass->pw_name, pass->pw_gid) != 0 )
388 goto err;
389
390 become_user_permanently(pass->pw_uid, pass->pw_gid);
391
392 /* Save the users name */
393 C_user = SMB_STRDUP(user);
394 TALLOC_FREE(pass);
395 return True;
396 }
397 }
398
399err:
400 cgi_setup_error("401 Bad Authorization",
401 "WWW-Authenticate: Basic realm=\"SWAT\"\r\n",
402 "username or password incorrect");
403
404 TALLOC_FREE(pass);
405 return False;
406}
407
408/***************************************************************************
409is this root?
410 ***************************************************************************/
411bool am_root(void)
412{
413 if (geteuid() == 0) {
414 return( True);
415 } else {
416 return( False);
417 }
418}
419
420/***************************************************************************
421return a ptr to the users name
422 ***************************************************************************/
423char *cgi_user_name(void)
424{
425 return(C_user);
426}
427
428
429/***************************************************************************
430handle a file download
431 ***************************************************************************/
432static void cgi_download(char *file)
433{
434 SMB_STRUCT_STAT st;
435 char buf[1024];
436 int fd, l, i;
437 char *p;
438 char *lang;
439
440 /* sanitise the filename */
441 for (i=0;file[i];i++) {
442 if (!isalnum((int)file[i]) && !strchr_m("/.-_", file[i])) {
443 cgi_setup_error("404 File Not Found","",
444 "Illegal character in filename");
445 }
446 }
447
448 if (sys_stat(file, &st, false) != 0) {
449 cgi_setup_error("404 File Not Found","",
450 "The requested file was not found");
451 }
452
453 if (S_ISDIR(st.st_ex_mode))
454 {
455 snprintf(buf, sizeof(buf), "%s/index.html", file);
456 if (!file_exist_stat(buf, &st, false)
457 || !S_ISREG(st.st_ex_mode))
458 {
459 cgi_setup_error("404 File Not Found","",
460 "The requested file was not found");
461 }
462 }
463 else if (S_ISREG(st.st_ex_mode))
464 {
465 snprintf(buf, sizeof(buf), "%s", file);
466 }
467 else
468 {
469 cgi_setup_error("404 File Not Found","",
470 "The requested file was not found");
471 }
472
473 fd = web_open(buf,O_RDONLY,0);
474 if (fd == -1) {
475 cgi_setup_error("404 File Not Found","",
476 "The requested file was not found");
477 }
478 printf("HTTP/1.0 200 OK\r\n");
479 if ((p=strrchr_m(buf, '.'))) {
480 if (strcmp(p,".gif")==0) {
481 printf("Content-Type: image/gif\r\n");
482 } else if (strcmp(p,".jpg")==0) {
483 printf("Content-Type: image/jpeg\r\n");
484 } else if (strcmp(p,".png")==0) {
485 printf("Content-Type: image/png\r\n");
486 } else if (strcmp(p,".css")==0) {
487 printf("Content-Type: text/css\r\n");
488 } else if (strcmp(p,".txt")==0) {
489 printf("Content-Type: text/plain\r\n");
490 } else {
491 printf("Content-Type: text/html\r\n");
492 }
493 }
494 printf("Expires: %s\r\n",
495 http_timestring(talloc_tos(), time(NULL)+EXPIRY_TIME));
496
497 lang = lang_tdb_current();
498 if (lang) {
499 printf("Content-Language: %s\r\n", lang);
500 }
501
502 printf("Content-Length: %d\r\n\r\n", (int)st.st_ex_size);
503 while ((l=read(fd,buf,sizeof(buf)))>0) {
504 if (fwrite(buf, 1, l, stdout) != l) {
505 break;
506 }
507 }
508 close(fd);
509 exit(0);
510}
511
512
513
514
515/**
516 * @brief Setup the CGI framework.
517 *
518 * Setup the cgi framework, handling the possibility that this program
519 * is either run as a true CGI program with a gateway to a web server, or
520 * is itself a mini web server.
521 **/
522void cgi_setup(const char *rootdir, int auth_required)
523{
524 bool authenticated = False;
525 char line[1024];
526 char *url=NULL;
527 char *p;
528 char *lang;
529
530 if (chdir(rootdir)) {
531 cgi_setup_error("500 Server Error", "",
532 "chdir failed - the server is not configured correctly");
533 }
534
535 /* Handle the possibility we might be running as non-root */
536 sec_init();
537
538 if ((lang=getenv("HTTP_ACCEPT_LANGUAGE"))) {
539 /* if running as a cgi program */
540 web_set_lang(lang);
541 }
542
543 /* maybe we are running under a web server */
544 if (getenv("CONTENT_LENGTH") || getenv("REQUEST_METHOD")) {
545 if (auth_required) {
546 cgi_web_auth();
547 }
548 return;
549 }
550
551 inetd_server = True;
552
553 if (!check_access(1, lp_hostsallow(-1), lp_hostsdeny(-1))) {
554 cgi_setup_error("403 Forbidden", "",
555 "Samba is configured to deny access from this client\n<br>Check your \"hosts allow\" and \"hosts deny\" options in smb.conf ");
556 }
557
558 /* we are a mini-web server. We need to read the request from stdin
559 and handle authentication etc */
560 while (fgets(line, sizeof(line)-1, stdin)) {
561 if (line[0] == '\r' || line[0] == '\n') break;
562 if (strnequal(line,"GET ", 4)) {
563 got_request = True;
564 url = SMB_STRDUP(&line[4]);
565 } else if (strnequal(line,"POST ", 5)) {
566 got_request = True;
567 request_post = 1;
568 url = SMB_STRDUP(&line[5]);
569 } else if (strnequal(line,"PUT ", 4)) {
570 got_request = True;
571 cgi_setup_error("400 Bad Request", "",
572 "This server does not accept PUT requests");
573 } else if (strnequal(line,"Authorization: ", 15)) {
574 authenticated = cgi_handle_authorization(&line[15]);
575 } else if (strnequal(line,"Content-Length: ", 16)) {
576 content_length = atoi(&line[16]);
577 } else if (strnequal(line,"Accept-Language: ", 17)) {
578 web_set_lang(&line[17]);
579 }
580 /* ignore all other requests! */
581 }
582
583 if (auth_required && !authenticated) {
584 cgi_auth_error();
585 }
586
587 if (!url) {
588 cgi_setup_error("400 Bad Request", "",
589 "You must specify a GET or POST request");
590 }
591
592 /* trim the URL */
593 if ((p = strchr_m(url,' ')) || (p=strchr_m(url,'\t'))) {
594 *p = 0;
595 }
596 while (*url && strchr_m("\r\n",url[strlen(url)-1])) {
597 url[strlen(url)-1] = 0;
598 }
599
600 /* anything following a ? in the URL is part of the query string */
601 if ((p=strchr_m(url,'?'))) {
602 query_string = p+1;
603 *p = 0;
604 }
605
606 string_sub(url, "/swat/", "", 0);
607
608 if (url[0] != '/' && strstr(url,"..")==0) {
609 cgi_download(url);
610 }
611
612 printf("HTTP/1.0 200 OK\r\nConnection: close\r\n");
613 printf("Date: %s\r\n", http_timestring(talloc_tos(), time(NULL)));
614 baseurl = "";
615 pathinfo = url+1;
616}
617
618
619/***************************************************************************
620return the current pages URL
621 ***************************************************************************/
622const char *cgi_baseurl(void)
623{
624 if (inetd_server) {
625 return baseurl;
626 }
627 return getenv("SCRIPT_NAME");
628}
629
630/***************************************************************************
631return the current pages path info
632 ***************************************************************************/
633const char *cgi_pathinfo(void)
634{
635 char *r;
636 if (inetd_server) {
637 return pathinfo;
638 }
639 r = getenv("PATH_INFO");
640 if (!r) return "";
641 if (*r == '/') r++;
642 return r;
643}
644
645/***************************************************************************
646return the hostname of the client
647 ***************************************************************************/
648const char *cgi_remote_host(void)
649{
650 if (inetd_server) {
651 return get_peer_name(1,False);
652 }
653 return getenv("REMOTE_HOST");
654}
655
656/***************************************************************************
657return the hostname of the client
658 ***************************************************************************/
659const char *cgi_remote_addr(void)
660{
661 if (inetd_server) {
662 char addr[INET6_ADDRSTRLEN];
663 get_peer_addr(1,addr,sizeof(addr));
664 return talloc_strdup(talloc_tos(), addr);
665 }
666 return getenv("REMOTE_ADDR");
667}
668
669
670/***************************************************************************
671return True if the request was a POST
672 ***************************************************************************/
673bool cgi_waspost(void)
674{
675 if (inetd_server) {
676 return request_post;
677 }
678 return strequal(getenv("REQUEST_METHOD"), "POST");
679}
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