source: vendor/3.5.10/source3/web/cgi.c

Last change on this file was 615, checked in by Herwig Bauernfeind, 14 years ago

Samba 3.5: Update vendor to version 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 pwd = Get_Pwnam_alloc(talloc_autofree_context(), user);
321 if (!pwd) {
322 printf("%sCannot find user %s<br>%s\n", head, user, tail);
323 exit(0);
324 }
325
326 C_user = SMB_STRDUP(user);
327
328 if (!setuid(0)) {
329 C_pass = secrets_fetch_generic("root", "SWAT");
330 if (C_pass == NULL) {
331 char *tmp_pass = NULL;
332 tmp_pass = generate_random_str(talloc_tos(), 16);
333 if (tmp_pass == NULL) {
334 printf("%sFailed to create random nonce for "
335 "SWAT session\n<br>%s\n", head, tail);
336 exit(0);
337 }
338 secrets_store_generic("root", "SWAT", tmp_pass);
339 C_pass = SMB_STRDUP(tmp_pass);
340 TALLOC_FREE(tmp_pass);
341 }
342 }
343 setuid(pwd->pw_uid);
344 if (geteuid() != pwd->pw_uid || getuid() != pwd->pw_uid) {
345 printf("%sFailed to become user %s - uid=%d/%d<br>%s\n",
346 head, user, (int)geteuid(), (int)getuid(), tail);
347 exit(0);
348 }
349 TALLOC_FREE(pwd);
350}
351
352
353/***************************************************************************
354handle a http authentication line
355 ***************************************************************************/
356static bool cgi_handle_authorization(char *line)
357{
358 char *p;
359 fstring user, user_pass;
360 struct passwd *pass = NULL;
361
362 if (!strnequal(line,"Basic ", 6)) {
363 goto err;
364 }
365 line += 6;
366 while (line[0] == ' ') line++;
367 base64_decode_inplace(line);
368 if (!(p=strchr_m(line,':'))) {
369 /*
370 * Always give the same error so a cracker
371 * cannot tell why we fail.
372 */
373 goto err;
374 }
375 *p = 0;
376
377 convert_string(CH_UTF8, CH_UNIX,
378 line, -1,
379 user, sizeof(user), True);
380
381 convert_string(CH_UTF8, CH_UNIX,
382 p+1, -1,
383 user_pass, sizeof(user_pass), True);
384
385 /*
386 * Try and get the user from the UNIX password file.
387 */
388
389 pass = Get_Pwnam_alloc(talloc_autofree_context(), user);
390
391 /*
392 * Validate the password they have given.
393 */
394
395 if NT_STATUS_IS_OK(pass_check(pass, user, user_pass,
396 strlen(user_pass), NULL, False)) {
397
398 if (pass) {
399 /*
400 * Password was ok.
401 */
402
403 if ( initgroups(pass->pw_name, pass->pw_gid) != 0 )
404 goto err;
405
406 become_user_permanently(pass->pw_uid, pass->pw_gid);
407
408 /* Save the users name */
409 C_user = SMB_STRDUP(user);
410 C_pass = SMB_STRDUP(user_pass);
411 TALLOC_FREE(pass);
412 return True;
413 }
414 }
415
416err:
417 cgi_setup_error("401 Bad Authorization",
418 "WWW-Authenticate: Basic realm=\"SWAT\"\r\n",
419 "username or password incorrect");
420
421 TALLOC_FREE(pass);
422 return False;
423}
424
425/***************************************************************************
426is this root?
427 ***************************************************************************/
428bool am_root(void)
429{
430 if (geteuid() == 0) {
431 return( True);
432 } else {
433 return( False);
434 }
435}
436
437/***************************************************************************
438return a ptr to the users name
439 ***************************************************************************/
440char *cgi_user_name(void)
441{
442 return(C_user);
443}
444
445/***************************************************************************
446return a ptr to the users password
447 ***************************************************************************/
448char *cgi_user_pass(void)
449{
450 return(C_pass);
451}
452
453/***************************************************************************
454handle a file download
455 ***************************************************************************/
456static void cgi_download(char *file)
457{
458 SMB_STRUCT_STAT st;
459 char buf[1024];
460 int fd, l, i;
461 char *p;
462 char *lang;
463
464 /* sanitise the filename */
465 for (i=0;file[i];i++) {
466 if (!isalnum((int)file[i]) && !strchr_m("/.-_", file[i])) {
467 cgi_setup_error("404 File Not Found","",
468 "Illegal character in filename");
469 }
470 }
471
472 if (sys_stat(file, &st, false) != 0) {
473 cgi_setup_error("404 File Not Found","",
474 "The requested file was not found");
475 }
476
477 if (S_ISDIR(st.st_ex_mode))
478 {
479 snprintf(buf, sizeof(buf), "%s/index.html", file);
480 if (!file_exist_stat(buf, &st, false)
481 || !S_ISREG(st.st_ex_mode))
482 {
483 cgi_setup_error("404 File Not Found","",
484 "The requested file was not found");
485 }
486 }
487 else if (S_ISREG(st.st_ex_mode))
488 {
489 snprintf(buf, sizeof(buf), "%s", file);
490 }
491 else
492 {
493 cgi_setup_error("404 File Not Found","",
494 "The requested file was not found");
495 }
496
497 fd = web_open(buf,O_RDONLY,0);
498 if (fd == -1) {
499 cgi_setup_error("404 File Not Found","",
500 "The requested file was not found");
501 }
502 printf("HTTP/1.0 200 OK\r\n");
503 if ((p=strrchr_m(buf, '.'))) {
504 if (strcmp(p,".gif")==0) {
505 printf("Content-Type: image/gif\r\n");
506 } else if (strcmp(p,".jpg")==0) {
507 printf("Content-Type: image/jpeg\r\n");
508 } else if (strcmp(p,".png")==0) {
509 printf("Content-Type: image/png\r\n");
510 } else if (strcmp(p,".css")==0) {
511 printf("Content-Type: text/css\r\n");
512 } else if (strcmp(p,".txt")==0) {
513 printf("Content-Type: text/plain\r\n");
514 } else {
515 printf("Content-Type: text/html\r\n");
516 }
517 }
518 printf("Expires: %s\r\n",
519 http_timestring(talloc_tos(), time(NULL)+EXPIRY_TIME));
520
521 lang = lang_tdb_current();
522 if (lang) {
523 printf("Content-Language: %s\r\n", lang);
524 }
525
526 printf("Content-Length: %d\r\n\r\n", (int)st.st_ex_size);
527 while ((l=read(fd,buf,sizeof(buf)))>0) {
528 if (fwrite(buf, 1, l, stdout) != l) {
529 break;
530 }
531 }
532 close(fd);
533 exit(0);
534}
535
536
537
538
539/**
540 * @brief Setup the CGI framework.
541 *
542 * Setup the cgi framework, handling the possibility that this program
543 * is either run as a true CGI program with a gateway to a web server, or
544 * is itself a mini web server.
545 **/
546void cgi_setup(const char *rootdir, int auth_required)
547{
548 bool authenticated = False;
549 char line[1024];
550 char *url=NULL;
551 char *p;
552 char *lang;
553
554 if (chdir(rootdir)) {
555 cgi_setup_error("500 Server Error", "",
556 "chdir failed - the server is not configured correctly");
557 }
558
559 /* Handle the possibility we might be running as non-root */
560 sec_init();
561
562 if ((lang=getenv("HTTP_ACCEPT_LANGUAGE"))) {
563 /* if running as a cgi program */
564 web_set_lang(lang);
565 }
566
567 /* maybe we are running under a web server */
568 if (getenv("CONTENT_LENGTH") || getenv("REQUEST_METHOD")) {
569 if (auth_required) {
570 cgi_web_auth();
571 }
572 return;
573 }
574
575 inetd_server = True;
576
577 if (!check_access(1, lp_hostsallow(-1), lp_hostsdeny(-1))) {
578 cgi_setup_error("403 Forbidden", "",
579 "Samba is configured to deny access from this client\n<br>Check your \"hosts allow\" and \"hosts deny\" options in smb.conf ");
580 }
581
582 /* we are a mini-web server. We need to read the request from stdin
583 and handle authentication etc */
584 while (fgets(line, sizeof(line)-1, stdin)) {
585 if (line[0] == '\r' || line[0] == '\n') break;
586 if (strnequal(line,"GET ", 4)) {
587 got_request = True;
588 url = SMB_STRDUP(&line[4]);
589 } else if (strnequal(line,"POST ", 5)) {
590 got_request = True;
591 request_post = 1;
592 url = SMB_STRDUP(&line[5]);
593 } else if (strnequal(line,"PUT ", 4)) {
594 got_request = True;
595 cgi_setup_error("400 Bad Request", "",
596 "This server does not accept PUT requests");
597 } else if (strnequal(line,"Authorization: ", 15)) {
598 authenticated = cgi_handle_authorization(&line[15]);
599 } else if (strnequal(line,"Content-Length: ", 16)) {
600 content_length = atoi(&line[16]);
601 } else if (strnequal(line,"Accept-Language: ", 17)) {
602 web_set_lang(&line[17]);
603 }
604 /* ignore all other requests! */
605 }
606
607 if (auth_required && !authenticated) {
608 cgi_auth_error();
609 }
610
611 if (!url) {
612 cgi_setup_error("400 Bad Request", "",
613 "You must specify a GET or POST request");
614 }
615
616 /* trim the URL */
617 if ((p = strchr_m(url,' ')) || (p=strchr_m(url,'\t'))) {
618 *p = 0;
619 }
620 while (*url && strchr_m("\r\n",url[strlen(url)-1])) {
621 url[strlen(url)-1] = 0;
622 }
623
624 /* anything following a ? in the URL is part of the query string */
625 if ((p=strchr_m(url,'?'))) {
626 query_string = p+1;
627 *p = 0;
628 }
629
630 string_sub(url, "/swat/", "", 0);
631
632 if (url[0] != '/' && strstr(url,"..")==0) {
633 cgi_download(url);
634 }
635
636 printf("HTTP/1.0 200 OK\r\nConnection: close\r\n");
637 printf("Date: %s\r\n", http_timestring(talloc_tos(), time(NULL)));
638 baseurl = "";
639 pathinfo = url+1;
640}
641
642
643/***************************************************************************
644return the current pages URL
645 ***************************************************************************/
646const char *cgi_baseurl(void)
647{
648 if (inetd_server) {
649 return baseurl;
650 }
651 return getenv("SCRIPT_NAME");
652}
653
654/***************************************************************************
655return the current pages path info
656 ***************************************************************************/
657const char *cgi_pathinfo(void)
658{
659 char *r;
660 if (inetd_server) {
661 return pathinfo;
662 }
663 r = getenv("PATH_INFO");
664 if (!r) return "";
665 if (*r == '/') r++;
666 return r;
667}
668
669/***************************************************************************
670return the hostname of the client
671 ***************************************************************************/
672const char *cgi_remote_host(void)
673{
674 if (inetd_server) {
675 return get_peer_name(1,False);
676 }
677 return getenv("REMOTE_HOST");
678}
679
680/***************************************************************************
681return the hostname of the client
682 ***************************************************************************/
683const char *cgi_remote_addr(void)
684{
685 if (inetd_server) {
686 char addr[INET6_ADDRSTRLEN];
687 get_peer_addr(1,addr,sizeof(addr));
688 return talloc_strdup(talloc_tos(), addr);
689 }
690 return getenv("REMOTE_ADDR");
691}
692
693
694/***************************************************************************
695return True if the request was a POST
696 ***************************************************************************/
697bool cgi_waspost(void)
698{
699 if (inetd_server) {
700 return request_post;
701 }
702 return strequal(getenv("REQUEST_METHOD"), "POST");
703}
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