source: trunk/server/source3/web/cgi.c@ 720

Last change on this file since 720 was 617, checked in by Herwig Bauernfeind, 14 years ago

Samba 3.5: Update trunk to 3.5.10
File size: 18.7 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#include "secrets.h"
23#include "../lib/util/util.h"
24
25#define MAX_VARIABLES 10000
26
27/* set the expiry on fixed pages */
28#define EXPIRY_TIME (60*60*24*7)
29
30#ifdef DEBUG_COMMENTS
31extern void print_title(char *fmt, ...);
32#endif
33
34struct cgi_var {
35 char *name;
36 char *value;
37};
38
39static struct cgi_var variables[MAX_VARIABLES];
40static int num_variables;
41static int content_length;
42static int request_post;
43static char *query_string;
44static const char *baseurl;
45static char *pathinfo;
46static char *C_user;
47static char *C_pass;
48static bool inetd_server;
49static bool got_request;
50
51static char *grab_line(FILE *f, int *cl)
52{
53 char *ret = NULL;
54 int i = 0;
55 int len = 0;
56
57 while ((*cl)) {
58 int c;
59
60 if (i == len) {
61 char *ret2;
62 if (len == 0) len = 1024;
63 else len *= 2;
64 ret2 = (char *)SMB_REALLOC_KEEP_OLD_ON_ERROR(ret, len);
65 if (!ret2) return ret;
66 ret = ret2;
67 }
68
69 c = fgetc(f);
70 (*cl)--;
71
72 if (c == EOF) {
73 (*cl) = 0;
74 break;
75 }
76
77 if (c == '\r') continue;
78
79 if (strchr_m("\n&", c)) break;
80
81 ret[i++] = c;
82
83 }
84
85 if (ret) {
86 ret[i] = 0;
87 }
88 return ret;
89}
90
91/**
92 URL encoded strings can have a '+', which should be replaced with a space
93
94 (This was in rfc1738_unescape(), but that broke the squid helper)
95**/
96
97static void plus_to_space_unescape(char *buf)
98{
99 char *p=buf;
100
101 while ((p=strchr_m(p,'+')))
102 *p = ' ';
103}
104
105/***************************************************************************
106 load all the variables passed to the CGI program. May have multiple variables
107 with the same name and the same or different values. Takes a file parameter
108 for simulating CGI invocation eg loading saved preferences.
109 ***************************************************************************/
110void cgi_load_variables(void)
111{
112 static char *line;
113 char *p, *s, *tok;
114 int len, i;
115 FILE *f = stdin;
116
117#ifdef DEBUG_COMMENTS
118 char dummy[100]="";
119 print_title(dummy);
120 d_printf("<!== Start dump in cgi_load_variables() %s ==>\n",__FILE__);
121#endif
122
123 if (!content_length) {
124 p = getenv("CONTENT_LENGTH");
125 len = p?atoi(p):0;
126 } else {
127 len = content_length;
128 }
129
130
131 if (len > 0 &&
132 (request_post ||
133 ((s=getenv("REQUEST_METHOD")) &&
134 strequal(s,"POST")))) {
135 while (len && (line=grab_line(f, &len))) {
136 p = strchr_m(line,'=');
137 if (!p) continue;
138
139 *p = 0;
140
141 variables[num_variables].name = SMB_STRDUP(line);
142 variables[num_variables].value = SMB_STRDUP(p+1);
143
144 SAFE_FREE(line);
145
146 if (!variables[num_variables].name ||
147 !variables[num_variables].value)
148 continue;
149
150 plus_to_space_unescape(variables[num_variables].value);
151 rfc1738_unescape(variables[num_variables].value);
152 plus_to_space_unescape(variables[num_variables].name);
153 rfc1738_unescape(variables[num_variables].name);
154
155#ifdef DEBUG_COMMENTS
156 printf("<!== POST var %s has value \"%s\" ==>\n",
157 variables[num_variables].name,
158 variables[num_variables].value);
159#endif
160
161 num_variables++;
162 if (num_variables == MAX_VARIABLES) break;
163 }
164 }
165
166 fclose(stdin);
167 open("/dev/null", O_RDWR);
168
169 if ((s=query_string) || (s=getenv("QUERY_STRING"))) {
170 char *saveptr;
171 for (tok=strtok_r(s, "&;", &saveptr); tok;
172 tok=strtok_r(NULL, "&;", &saveptr)) {
173 p = strchr_m(tok,'=');
174 if (!p) continue;
175
176 *p = 0;
177
178 variables[num_variables].name = SMB_STRDUP(tok);
179 variables[num_variables].value = SMB_STRDUP(p+1);
180
181 if (!variables[num_variables].name ||
182 !variables[num_variables].value)
183 continue;
184
185 plus_to_space_unescape(variables[num_variables].value);
186 rfc1738_unescape(variables[num_variables].value);
187 plus_to_space_unescape(variables[num_variables].name);
188 rfc1738_unescape(variables[num_variables].name);
189
190#ifdef DEBUG_COMMENTS
191 printf("<!== Commandline var %s has value \"%s\" ==>\n",
192 variables[num_variables].name,
193 variables[num_variables].value);
194#endif
195 num_variables++;
196 if (num_variables == MAX_VARIABLES) break;
197 }
198
199 }
200#ifdef DEBUG_COMMENTS
201 printf("<!== End dump in cgi_load_variables() ==>\n");
202#endif
203
204 /* variables from the client are in UTF-8 - convert them
205 to our internal unix charset before use */
206 for (i=0;i<num_variables;i++) {
207 TALLOC_CTX *frame = talloc_stackframe();
208 char *dest = NULL;
209 size_t dest_len;
210
211 convert_string_talloc(frame, CH_UTF8, CH_UNIX,
212 variables[i].name, strlen(variables[i].name),
213 &dest, &dest_len, True);
214 SAFE_FREE(variables[i].name);
215 variables[i].name = SMB_STRDUP(dest ? dest : "");
216
217 dest = NULL;
218 convert_string_talloc(frame, CH_UTF8, CH_UNIX,
219 variables[i].value, strlen(variables[i].value),
220 &dest, &dest_len, True);
221 SAFE_FREE(variables[i].value);
222 variables[i].value = SMB_STRDUP(dest ? dest : "");
223 TALLOC_FREE(frame);
224 }
225}
226
227
228/***************************************************************************
229 find a variable passed via CGI
230 Doesn't quite do what you think in the case of POST text variables, because
231 if they exist they might have a value of "" or even " ", depending on the
232 browser. Also doesn't allow for variables[] containing multiple variables
233 with the same name and the same or different values.
234 ***************************************************************************/
235
236const char *cgi_variable(const char *name)
237{
238 int i;
239
240 for (i=0;i<num_variables;i++)
241 if (strcmp(variables[i].name, name) == 0)
242 return variables[i].value;
243 return NULL;
244}
245
246/***************************************************************************
247 Version of the above that can't return a NULL pointer.
248***************************************************************************/
249
250const char *cgi_variable_nonull(const char *name)
251{
252 const char *var = cgi_variable(name);
253 if (var) {
254 return var;
255 } else {
256 return "";
257 }
258}
259
260/***************************************************************************
261tell a browser about a fatal error in the http processing
262 ***************************************************************************/
263static void cgi_setup_error(const char *err, const char *header, const char *info)
264{
265 if (!got_request) {
266 /* damn browsers don't like getting cut off before they give a request */
267 char line[1024];
268 while (fgets(line, sizeof(line)-1, stdin)) {
269 if (strnequal(line,"GET ", 4) ||
270 strnequal(line,"POST ", 5) ||
271 strnequal(line,"PUT ", 4)) {
272 break;
273 }
274 }
275 }
276
277 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);
278 fclose(stdin);
279 fclose(stdout);
280 exit(0);
281}
282
283
284/***************************************************************************
285tell a browser about a fatal authentication error
286 ***************************************************************************/
287static void cgi_auth_error(void)
288{
289 if (inetd_server) {
290 cgi_setup_error("401 Authorization Required",
291 "WWW-Authenticate: Basic realm=\"SWAT\"\r\n",
292 "You must be authenticated to use this service");
293 } else {
294 printf("Content-Type: text/html\r\n");
295
296 printf("\r\n<HTML><HEAD><TITLE>SWAT</TITLE></HEAD>\n");
297 printf("<BODY><H1>Installation Error</H1>\n");
298 printf("SWAT must be installed via inetd. It cannot be run as a CGI script<p>\n");
299 printf("</BODY></HTML>\r\n");
300 }
301 exit(0);
302}
303
304/***************************************************************************
305authenticate when we are running as a CGI
306 ***************************************************************************/
307static void cgi_web_auth(void)
308{
309 const char *user = getenv("REMOTE_USER");
310 struct passwd *pwd;
311 const char *head = "Content-Type: text/html\r\n\r\n<HTML><BODY><H1>SWAT installation Error</H1>\n";
312 const char *tail = "</BODY></HTML>\r\n";
313
314 if (!user) {
315 printf("%sREMOTE_USER not set. Not authenticated by web server.<br>%s\n",
316 head, tail);
317 exit(0);
318 }
319
320#ifndef __OS2__
321 pwd = Get_Pwnam_alloc(talloc_autofree_context(), user);
322
323 if (!pwd) {
324 printf("%sCannot find user %s<br>%s\n", head, user, tail);
325 exit(0);
326 }
327
328 C_user = SMB_STRDUP(user);
329
330 if (!setuid(0)) {
331 C_pass = secrets_fetch_generic("root", "SWAT");
332 if (C_pass == NULL) {
333 char *tmp_pass = NULL;
334 tmp_pass = generate_random_str(talloc_tos(), 16);
335 if (tmp_pass == NULL) {
336 printf("%sFailed to create random nonce for "
337 "SWAT session\n<br>%s\n", head, tail);
338 exit(0);
339 }
340 secrets_store_generic("root", "SWAT", tmp_pass);
341 C_pass = SMB_STRDUP(tmp_pass);
342 TALLOC_FREE(tmp_pass);
343 }
344 }
345 setuid(pwd->pw_uid);
346 if (geteuid() != pwd->pw_uid || getuid() != pwd->pw_uid) {
347 printf("%sFailed to become user %s - uid=%d/%d<br>%s\n",
348 head, user, (int)geteuid(), (int)getuid(), tail);
349 exit(0);
350 }
351 TALLOC_FREE(pwd);
352#endif
353}
354
355
356/***************************************************************************
357handle a http authentication line
358 ***************************************************************************/
359static bool cgi_handle_authorization(char *line)
360{
361 char *p;
362 fstring user, user_pass;
363 struct passwd *pass = NULL;
364
365 if (!strnequal(line,"Basic ", 6)) {
366 goto err;
367 }
368 line += 6;
369 while (line[0] == ' ') line++;
370 base64_decode_inplace(line);
371 if (!(p=strchr_m(line,':'))) {
372 /*
373 * Always give the same error so a cracker
374 * cannot tell why we fail.
375 */
376 goto err;
377 }
378 *p = 0;
379
380 convert_string(CH_UTF8, CH_UNIX,
381 line, -1,
382 user, sizeof(user), True);
383
384 convert_string(CH_UTF8, CH_UNIX,
385 p+1, -1,
386 user_pass, sizeof(user_pass), True);
387
388 /*
389 * Try and get the user from the UNIX password file.
390 */
391
392 pass = Get_Pwnam_alloc(talloc_autofree_context(), user);
393
394 /*
395 * Validate the password they have given.
396 */
397
398 if NT_STATUS_IS_OK(pass_check(pass, user, user_pass,
399 strlen(user_pass), NULL, False)) {
400
401 if (pass) {
402 /*
403 * Password was ok.
404 */
405
406 if ( initgroups(pass->pw_name, pass->pw_gid) != 0 )
407 goto err;
408
409 become_user_permanently(pass->pw_uid, pass->pw_gid);
410
411 /* Save the users name */
412 C_user = SMB_STRDUP(user);
413 C_pass = SMB_STRDUP(user_pass);
414 TALLOC_FREE(pass);
415 return True;
416 }
417 }
418
419err:
420 cgi_setup_error("401 Bad Authorization",
421 "WWW-Authenticate: Basic realm=\"SWAT\"\r\n",
422 "username or password incorrect");
423
424 TALLOC_FREE(pass);
425 return False;
426}
427
428/***************************************************************************
429is this root?
430 ***************************************************************************/
431bool am_root(void)
432{
433 if (geteuid() == 0) {
434 return( True);
435 } else {
436 return( False);
437 }
438}
439
440/***************************************************************************
441return a ptr to the users name
442 ***************************************************************************/
443char *cgi_user_name(void)
444{
445 return(C_user);
446}
447
448/***************************************************************************
449return a ptr to the users password
450 ***************************************************************************/
451char *cgi_user_pass(void)
452{
453 return(C_pass);
454}
455
456/***************************************************************************
457handle a file download
458 ***************************************************************************/
459static void cgi_download(char *file)
460{
461 SMB_STRUCT_STAT st;
462 char buf[1024];
463 int fd, l, i;
464 char *p;
465 char *lang;
466
467 /* sanitise the filename */
468 for (i=0;file[i];i++) {
469 if (!isalnum((int)file[i]) && !strchr_m("/.-_", file[i])) {
470 cgi_setup_error("404 File Not Found","",
471 "Illegal character in filename");
472 }
473 }
474
475 if (sys_stat(file, &st, false) != 0) {
476 cgi_setup_error("404 File Not Found","",
477 "The requested file was not found");
478 }
479
480 if (S_ISDIR(st.st_ex_mode))
481 {
482 snprintf(buf, sizeof(buf), "%s/index.html", file);
483 if (!file_exist_stat(buf, &st, false)
484 || !S_ISREG(st.st_ex_mode))
485 {
486 cgi_setup_error("404 File Not Found","",
487 "The requested file was not found");
488 }
489 }
490 else if (S_ISREG(st.st_ex_mode))
491 {
492 snprintf(buf, sizeof(buf), "%s", file);
493 }
494 else
495 {
496 cgi_setup_error("404 File Not Found","",
497 "The requested file was not found");
498 }
499
500 fd = web_open(buf,O_RDONLY,0);
501 if (fd == -1) {
502 cgi_setup_error("404 File Not Found","",
503 "The requested file was not found");
504 }
505 printf("HTTP/1.0 200 OK\r\n");
506 if ((p=strrchr_m(buf, '.'))) {
507 if (strcmp(p,".gif")==0) {
508 printf("Content-Type: image/gif\r\n");
509 } else if (strcmp(p,".jpg")==0) {
510 printf("Content-Type: image/jpeg\r\n");
511 } else if (strcmp(p,".png")==0) {
512 printf("Content-Type: image/png\r\n");
513 } else if (strcmp(p,".css")==0) {
514 printf("Content-Type: text/css\r\n");
515 } else if (strcmp(p,".txt")==0) {
516 printf("Content-Type: text/plain\r\n");
517 } else {
518 printf("Content-Type: text/html\r\n");
519 }
520 }
521 printf("Expires: %s\r\n",
522 http_timestring(talloc_tos(), time(NULL)+EXPIRY_TIME));
523
524 lang = lang_tdb_current();
525 if (lang) {
526 printf("Content-Language: %s\r\n", lang);
527 }
528
529 printf("Content-Length: %d\r\n\r\n", (int)st.st_ex_size);
530 while ((l=read(fd,buf,sizeof(buf)))>0) {
531 if (fwrite(buf, 1, l, stdout) != l) {
532 break;
533 }
534 }
535 close(fd);
536 exit(0);
537}
538
539
540
541
542/**
543 * @brief Setup the CGI framework.
544 *
545 * Setup the cgi framework, handling the possibility that this program
546 * is either run as a true CGI program with a gateway to a web server, or
547 * is itself a mini web server.
548 **/
549void cgi_setup(const char *rootdir, int auth_required)
550{
551 bool authenticated = False;
552 char line[1024];
553 char *url=NULL;
554 char *p;
555 char *lang;
556
557 if (chdir(rootdir)) {
558 cgi_setup_error("500 Server Error", "",
559 "chdir failed - the server is not configured correctly");
560 }
561
562 /* Handle the possibility we might be running as non-root */
563 sec_init();
564
565 if ((lang=getenv("HTTP_ACCEPT_LANGUAGE"))) {
566 /* if running as a cgi program */
567 web_set_lang(lang);
568 }
569
570 /* maybe we are running under a web server */
571 if (getenv("CONTENT_LENGTH") || getenv("REQUEST_METHOD")) {
572 if (auth_required) {
573 cgi_web_auth();
574 }
575 return;
576 }
577
578 inetd_server = True;
579
580 if (!check_access(1, lp_hostsallow(-1), lp_hostsdeny(-1))) {
581 cgi_setup_error("403 Forbidden", "",
582 "Samba is configured to deny access from this client\n<br>Check your \"hosts allow\" and \"hosts deny\" options in smb.conf ");
583 }
584
585 /* we are a mini-web server. We need to read the request from stdin
586 and handle authentication etc */
587 while (fgets(line, sizeof(line)-1, stdin)) {
588 if (line[0] == '\r' || line[0] == '\n') break;
589 if (strnequal(line,"GET ", 4)) {
590 got_request = True;
591 url = SMB_STRDUP(&line[4]);
592 } else if (strnequal(line,"POST ", 5)) {
593 got_request = True;
594 request_post = 1;
595 url = SMB_STRDUP(&line[5]);
596 } else if (strnequal(line,"PUT ", 4)) {
597 got_request = True;
598 cgi_setup_error("400 Bad Request", "",
599 "This server does not accept PUT requests");
600 } else if (strnequal(line,"Authorization: ", 15)) {
601 authenticated = cgi_handle_authorization(&line[15]);
602 } else if (strnequal(line,"Content-Length: ", 16)) {
603 content_length = atoi(&line[16]);
604 } else if (strnequal(line,"Accept-Language: ", 17)) {
605 web_set_lang(&line[17]);
606 }
607 /* ignore all other requests! */
608 }
609
610 if (auth_required && !authenticated) {
611 cgi_auth_error();
612 }
613
614 if (!url) {
615 cgi_setup_error("400 Bad Request", "",
616 "You must specify a GET or POST request");
617 }
618
619 /* trim the URL */
620 if ((p = strchr_m(url,' ')) || (p=strchr_m(url,'\t'))) {
621 *p = 0;
622 }
623 while (*url && strchr_m("\r\n",url[strlen(url)-1])) {
624 url[strlen(url)-1] = 0;
625 }
626
627 /* anything following a ? in the URL is part of the query string */
628 if ((p=strchr_m(url,'?'))) {
629 query_string = p+1;
630 *p = 0;
631 }
632
633 string_sub(url, "/swat/", "", 0);
634
635 if (url[0] != '/' && strstr(url,"..")==0) {
636 cgi_download(url);
637 }
638
639 printf("HTTP/1.0 200 OK\r\nConnection: close\r\n");
640 printf("Date: %s\r\n", http_timestring(talloc_tos(), time(NULL)));
641 baseurl = "";
642 pathinfo = url+1;
643}
644
645
646/***************************************************************************
647return the current pages URL
648 ***************************************************************************/
649const char *cgi_baseurl(void)
650{
651 if (inetd_server) {
652 return baseurl;
653 }
654 return getenv("SCRIPT_NAME");
655}
656
657/***************************************************************************
658return the current pages path info
659 ***************************************************************************/
660const char *cgi_pathinfo(void)
661{
662 char *r;
663 if (inetd_server) {
664 return pathinfo;
665 }
666 r = getenv("PATH_INFO");
667 if (!r) return "";
668 if (*r == '/') r++;
669 return r;
670}
671
672/***************************************************************************
673return the hostname of the client
674 ***************************************************************************/
675const char *cgi_remote_host(void)
676{
677 if (inetd_server) {
678 return get_peer_name(1,False);
679 }
680 return getenv("REMOTE_HOST");
681}
682
683/***************************************************************************
684return the hostname of the client
685 ***************************************************************************/
686const char *cgi_remote_addr(void)
687{
688 if (inetd_server) {
689 char addr[INET6_ADDRSTRLEN];
690 get_peer_addr(1,addr,sizeof(addr));
691 return talloc_strdup(talloc_tos(), addr);
692 }
693 return getenv("REMOTE_ADDR");
694}
695
696
697/***************************************************************************
698return True if the request was a POST
699 ***************************************************************************/
700bool cgi_waspost(void)
701{
702 if (inetd_server) {
703 return request_post;
704 }
705 return strequal(getenv("REQUEST_METHOD"), "POST");
706}
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