source: branches/samba-3.5.x/source3/web/cgi.c@ 791

Last change on this file since 791 was 774, checked in by Herwig Bauernfeind, 12 years ago

Samba Server 3.5: Update branch to 3.5.21
File size: 19.2 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 char *C_nonce;
49static bool inetd_server;
50static bool got_request;
51
52static char *grab_line(FILE *f, int *cl)
53{
54 char *ret = NULL;
55 int i = 0;
56 int len = 0;
57
58 while ((*cl)) {
59 int c;
60
61 if (i == len) {
62 char *ret2;
63 if (len == 0) len = 1024;
64 else len *= 2;
65 ret2 = (char *)SMB_REALLOC_KEEP_OLD_ON_ERROR(ret, len);
66 if (!ret2) return ret;
67 ret = ret2;
68 }
69
70 c = fgetc(f);
71 (*cl)--;
72
73 if (c == EOF) {
74 (*cl) = 0;
75 break;
76 }
77
78 if (c == '\r') continue;
79
80 if (strchr_m("\n&", c)) break;
81
82 ret[i++] = c;
83
84 }
85
86 if (ret) {
87 ret[i] = 0;
88 }
89 return ret;
90}
91
92/**
93 URL encoded strings can have a '+', which should be replaced with a space
94
95 (This was in rfc1738_unescape(), but that broke the squid helper)
96**/
97
98static void plus_to_space_unescape(char *buf)
99{
100 char *p=buf;
101
102 while ((p=strchr_m(p,'+')))
103 *p = ' ';
104}
105
106/***************************************************************************
107 load all the variables passed to the CGI program. May have multiple variables
108 with the same name and the same or different values. Takes a file parameter
109 for simulating CGI invocation eg loading saved preferences.
110 ***************************************************************************/
111void cgi_load_variables(void)
112{
113 static char *line;
114 char *p, *s, *tok;
115 int len, i;
116 FILE *f = stdin;
117
118#ifdef DEBUG_COMMENTS
119 char dummy[100]="";
120 print_title(dummy);
121 d_printf("<!== Start dump in cgi_load_variables() %s ==>\n",__FILE__);
122#endif
123
124 if (!content_length) {
125 p = getenv("CONTENT_LENGTH");
126 len = p?atoi(p):0;
127 } else {
128 len = content_length;
129 }
130
131
132 if (len > 0 &&
133 (request_post ||
134 ((s=getenv("REQUEST_METHOD")) &&
135 strequal(s,"POST")))) {
136 while (len && (line=grab_line(f, &len))) {
137 p = strchr_m(line,'=');
138 if (!p) continue;
139
140 *p = 0;
141
142 variables[num_variables].name = SMB_STRDUP(line);
143 variables[num_variables].value = SMB_STRDUP(p+1);
144
145 SAFE_FREE(line);
146
147 if (!variables[num_variables].name ||
148 !variables[num_variables].value)
149 continue;
150
151 plus_to_space_unescape(variables[num_variables].value);
152 rfc1738_unescape(variables[num_variables].value);
153 plus_to_space_unescape(variables[num_variables].name);
154 rfc1738_unescape(variables[num_variables].name);
155
156#ifdef DEBUG_COMMENTS
157 printf("<!== POST var %s has value \"%s\" ==>\n",
158 variables[num_variables].name,
159 variables[num_variables].value);
160#endif
161
162 num_variables++;
163 if (num_variables == MAX_VARIABLES) break;
164 }
165 }
166
167 fclose(stdin);
168 open("/dev/null", O_RDWR);
169
170 if ((s=query_string) || (s=getenv("QUERY_STRING"))) {
171 char *saveptr;
172 for (tok=strtok_r(s, "&;", &saveptr); tok;
173 tok=strtok_r(NULL, "&;", &saveptr)) {
174 p = strchr_m(tok,'=');
175 if (!p) continue;
176
177 *p = 0;
178
179 variables[num_variables].name = SMB_STRDUP(tok);
180 variables[num_variables].value = SMB_STRDUP(p+1);
181
182 if (!variables[num_variables].name ||
183 !variables[num_variables].value)
184 continue;
185
186 plus_to_space_unescape(variables[num_variables].value);
187 rfc1738_unescape(variables[num_variables].value);
188 plus_to_space_unescape(variables[num_variables].name);
189 rfc1738_unescape(variables[num_variables].name);
190
191#ifdef DEBUG_COMMENTS
192 printf("<!== Commandline var %s has value \"%s\" ==>\n",
193 variables[num_variables].name,
194 variables[num_variables].value);
195#endif
196 num_variables++;
197 if (num_variables == MAX_VARIABLES) break;
198 }
199
200 }
201#ifdef DEBUG_COMMENTS
202 printf("<!== End dump in cgi_load_variables() ==>\n");
203#endif
204
205 /* variables from the client are in UTF-8 - convert them
206 to our internal unix charset before use */
207 for (i=0;i<num_variables;i++) {
208 TALLOC_CTX *frame = talloc_stackframe();
209 char *dest = NULL;
210 size_t dest_len;
211
212 convert_string_talloc(frame, CH_UTF8, CH_UNIX,
213 variables[i].name, strlen(variables[i].name),
214 &dest, &dest_len, True);
215 SAFE_FREE(variables[i].name);
216 variables[i].name = SMB_STRDUP(dest ? dest : "");
217
218 dest = NULL;
219 convert_string_talloc(frame, CH_UTF8, CH_UNIX,
220 variables[i].value, strlen(variables[i].value),
221 &dest, &dest_len, True);
222 SAFE_FREE(variables[i].value);
223 variables[i].value = SMB_STRDUP(dest ? dest : "");
224 TALLOC_FREE(frame);
225 }
226}
227
228
229/***************************************************************************
230 find a variable passed via CGI
231 Doesn't quite do what you think in the case of POST text variables, because
232 if they exist they might have a value of "" or even " ", depending on the
233 browser. Also doesn't allow for variables[] containing multiple variables
234 with the same name and the same or different values.
235 ***************************************************************************/
236
237const char *cgi_variable(const char *name)
238{
239 int i;
240
241 for (i=0;i<num_variables;i++)
242 if (strcmp(variables[i].name, name) == 0)
243 return variables[i].value;
244 return NULL;
245}
246
247/***************************************************************************
248 Version of the above that can't return a NULL pointer.
249***************************************************************************/
250
251const char *cgi_variable_nonull(const char *name)
252{
253 const char *var = cgi_variable(name);
254 if (var) {
255 return var;
256 } else {
257 return "";
258 }
259}
260
261/***************************************************************************
262tell a browser about a fatal error in the http processing
263 ***************************************************************************/
264static void cgi_setup_error(const char *err, const char *header, const char *info)
265{
266 if (!got_request) {
267 /* damn browsers don't like getting cut off before they give a request */
268 char line[1024];
269 while (fgets(line, sizeof(line)-1, stdin)) {
270 if (strnequal(line,"GET ", 4) ||
271 strnequal(line,"POST ", 5) ||
272 strnequal(line,"PUT ", 4)) {
273 break;
274 }
275 }
276 }
277
278 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);
279 fclose(stdin);
280 fclose(stdout);
281 exit(0);
282}
283
284
285/***************************************************************************
286tell a browser about a fatal authentication error
287 ***************************************************************************/
288static void cgi_auth_error(void)
289{
290 if (inetd_server) {
291 cgi_setup_error("401 Authorization Required",
292 "WWW-Authenticate: Basic realm=\"SWAT\"\r\n",
293 "You must be authenticated to use this service");
294 } else {
295 printf("Content-Type: text/html\r\n");
296
297 printf("\r\n<HTML><HEAD><TITLE>SWAT</TITLE></HEAD>\n");
298 printf("<BODY><H1>Installation Error</H1>\n");
299 printf("SWAT must be installed via inetd. It cannot be run as a CGI script<p>\n");
300 printf("</BODY></HTML>\r\n");
301 }
302 exit(0);
303}
304
305/***************************************************************************
306authenticate when we are running as a CGI
307 ***************************************************************************/
308static void cgi_web_auth(void)
309{
310 const char *user = getenv("REMOTE_USER");
311 struct passwd *pwd;
312 const char *head = "Content-Type: text/html\r\n\r\n<HTML><BODY><H1>SWAT installation Error</H1>\n";
313 const char *tail = "</BODY></HTML>\r\n";
314
315 if (!user) {
316 printf("%sREMOTE_USER not set. Not authenticated by web server.<br>%s\n",
317 head, tail);
318 exit(0);
319 }
320
321#ifndef __OS2__
322 pwd = Get_Pwnam_alloc(talloc_autofree_context(), user);
323
324 if (!pwd) {
325 printf("%sCannot find user %s<br>%s\n", head, user, tail);
326 exit(0);
327 }
328
329 C_user = SMB_STRDUP(user);
330
331 if (!setuid(0)) {
332 C_pass = SMB_STRDUP(cgi_nonce());
333 }
334 setuid(pwd->pw_uid);
335 if (geteuid() != pwd->pw_uid || getuid() != pwd->pw_uid) {
336 printf("%sFailed to become user %s - uid=%d/%d<br>%s\n",
337 head, user, (int)geteuid(), (int)getuid(), tail);
338 exit(0);
339 }
340 TALLOC_FREE(pwd);
341#endif
342}
343
344
345/***************************************************************************
346handle a http authentication line
347 ***************************************************************************/
348static bool cgi_handle_authorization(char *line)
349{
350 char *p;
351 fstring user, user_pass;
352 struct passwd *pass = NULL;
353
354 if (!strnequal(line,"Basic ", 6)) {
355 goto err;
356 }
357 line += 6;
358 while (line[0] == ' ') line++;
359 base64_decode_inplace(line);
360 if (!(p=strchr_m(line,':'))) {
361 /*
362 * Always give the same error so a cracker
363 * cannot tell why we fail.
364 */
365 goto err;
366 }
367 *p = 0;
368
369 convert_string(CH_UTF8, CH_UNIX,
370 line, -1,
371 user, sizeof(user), True);
372
373 convert_string(CH_UTF8, CH_UNIX,
374 p+1, -1,
375 user_pass, sizeof(user_pass), True);
376
377 /*
378 * Try and get the user from the UNIX password file.
379 */
380
381 pass = Get_Pwnam_alloc(talloc_autofree_context(), user);
382
383 /*
384 * Validate the password they have given.
385 */
386
387 if NT_STATUS_IS_OK(pass_check(pass, user, user_pass,
388 strlen(user_pass), NULL, False)) {
389
390 if (pass) {
391 /*
392 * Password was ok.
393 */
394
395 if ( initgroups(pass->pw_name, pass->pw_gid) != 0 )
396 goto err;
397
398 become_user_permanently(pass->pw_uid, pass->pw_gid);
399
400 /* Save the users name */
401 C_user = SMB_STRDUP(user);
402 C_pass = SMB_STRDUP(user_pass);
403 TALLOC_FREE(pass);
404 return True;
405 }
406 }
407
408err:
409 cgi_setup_error("401 Bad Authorization",
410 "WWW-Authenticate: Basic realm=\"SWAT\"\r\n",
411 "username or password incorrect");
412
413 TALLOC_FREE(pass);
414 return False;
415}
416
417/***************************************************************************
418is this root?
419 ***************************************************************************/
420bool am_root(void)
421{
422 if (geteuid() == 0) {
423 return( True);
424 } else {
425 return( False);
426 }
427}
428
429/***************************************************************************
430return a ptr to the users name
431 ***************************************************************************/
432char *cgi_user_name(void)
433{
434 return(C_user);
435}
436
437/***************************************************************************
438return a ptr to the users password
439 ***************************************************************************/
440char *cgi_user_pass(void)
441{
442 return(C_pass);
443}
444
445/***************************************************************************
446return a ptr to the nonce
447 ***************************************************************************/
448char *cgi_nonce(void)
449{
450 const char *head = "Content-Type: text/html\r\n\r\n<HTML><BODY><H1>SWAT installation Error</H1>\n";
451 const char *tail = "</BODY></HTML>\r\n";
452 C_nonce = secrets_fetch_generic("root", "SWAT");
453 if (C_nonce == NULL) {
454 char *tmp_pass = NULL;
455 tmp_pass = generate_random_str(talloc_tos(), 16);
456 if (tmp_pass == NULL) {
457 printf("%sFailed to create random nonce for "
458 "SWAT session\n<br>%s\n", head, tail);
459 exit(0);
460 }
461 secrets_store_generic("root", "SWAT", tmp_pass);
462 C_nonce = SMB_STRDUP(tmp_pass);
463 TALLOC_FREE(tmp_pass);
464 }
465 return(C_nonce);
466}
467
468
469/***************************************************************************
470handle a file download
471 ***************************************************************************/
472static void cgi_download(char *file)
473{
474 SMB_STRUCT_STAT st;
475 char buf[1024];
476 int fd, l, i;
477 char *p;
478 char *lang;
479
480 /* sanitise the filename */
481 for (i=0;file[i];i++) {
482 if (!isalnum((int)file[i]) && !strchr_m("/.-_", file[i])) {
483 cgi_setup_error("404 File Not Found","",
484 "Illegal character in filename");
485 }
486 }
487
488 if (sys_stat(file, &st, false) != 0) {
489 cgi_setup_error("404 File Not Found","",
490 "The requested file was not found");
491 }
492
493 if (S_ISDIR(st.st_ex_mode))
494 {
495 snprintf(buf, sizeof(buf), "%s/index.html", file);
496 if (!file_exist_stat(buf, &st, false)
497 || !S_ISREG(st.st_ex_mode))
498 {
499 cgi_setup_error("404 File Not Found","",
500 "The requested file was not found");
501 }
502 }
503 else if (S_ISREG(st.st_ex_mode))
504 {
505 snprintf(buf, sizeof(buf), "%s", file);
506 }
507 else
508 {
509 cgi_setup_error("404 File Not Found","",
510 "The requested file was not found");
511 }
512
513 fd = web_open(buf,O_RDONLY,0);
514 if (fd == -1) {
515 cgi_setup_error("404 File Not Found","",
516 "The requested file was not found");
517 }
518 printf("HTTP/1.0 200 OK\r\n");
519 if ((p=strrchr_m(buf, '.'))) {
520 if (strcmp(p,".gif")==0) {
521 printf("Content-Type: image/gif\r\n");
522 } else if (strcmp(p,".jpg")==0) {
523 printf("Content-Type: image/jpeg\r\n");
524 } else if (strcmp(p,".png")==0) {
525 printf("Content-Type: image/png\r\n");
526 } else if (strcmp(p,".css")==0) {
527 printf("Content-Type: text/css\r\n");
528 } else if (strcmp(p,".txt")==0) {
529 printf("Content-Type: text/plain\r\n");
530 } else {
531 printf("Content-Type: text/html\r\n");
532 }
533 }
534 printf("Expires: %s\r\n",
535 http_timestring(talloc_tos(), time(NULL)+EXPIRY_TIME));
536
537 lang = lang_tdb_current();
538 if (lang) {
539 printf("Content-Language: %s\r\n", lang);
540 }
541
542 printf("Content-Length: %d\r\n\r\n", (int)st.st_ex_size);
543 while ((l=read(fd,buf,sizeof(buf)))>0) {
544 if (fwrite(buf, 1, l, stdout) != l) {
545 break;
546 }
547 }
548 close(fd);
549 exit(0);
550}
551
552
553
554
555/**
556 * @brief Setup the CGI framework.
557 *
558 * Setup the cgi framework, handling the possibility that this program
559 * is either run as a true CGI program with a gateway to a web server, or
560 * is itself a mini web server.
561 **/
562void cgi_setup(const char *rootdir, int auth_required)
563{
564 bool authenticated = False;
565 char line[1024];
566 char *url=NULL;
567 char *p;
568 char *lang;
569
570 if (chdir(rootdir)) {
571 cgi_setup_error("500 Server Error", "",
572 "chdir failed - the server is not configured correctly");
573 }
574
575 /* Handle the possibility we might be running as non-root */
576 sec_init();
577
578 if ((lang=getenv("HTTP_ACCEPT_LANGUAGE"))) {
579 /* if running as a cgi program */
580 web_set_lang(lang);
581 }
582
583 /* maybe we are running under a web server */
584 if (getenv("CONTENT_LENGTH") || getenv("REQUEST_METHOD")) {
585 if (auth_required) {
586 cgi_web_auth();
587 }
588 return;
589 }
590
591 inetd_server = True;
592
593 if (!check_access(1, lp_hostsallow(-1), lp_hostsdeny(-1))) {
594 cgi_setup_error("403 Forbidden", "",
595 "Samba is configured to deny access from this client\n<br>Check your \"hosts allow\" and \"hosts deny\" options in smb.conf ");
596 }
597
598 /* we are a mini-web server. We need to read the request from stdin
599 and handle authentication etc */
600 while (fgets(line, sizeof(line)-1, stdin)) {
601 if (line[0] == '\r' || line[0] == '\n') break;
602 if (strnequal(line,"GET ", 4)) {
603 got_request = True;
604 url = SMB_STRDUP(&line[4]);
605 } else if (strnequal(line,"POST ", 5)) {
606 got_request = True;
607 request_post = 1;
608 url = SMB_STRDUP(&line[5]);
609 } else if (strnequal(line,"PUT ", 4)) {
610 got_request = True;
611 cgi_setup_error("400 Bad Request", "",
612 "This server does not accept PUT requests");
613 } else if (strnequal(line,"Authorization: ", 15)) {
614 authenticated = cgi_handle_authorization(&line[15]);
615 } else if (strnequal(line,"Content-Length: ", 16)) {
616 content_length = atoi(&line[16]);
617 } else if (strnequal(line,"Accept-Language: ", 17)) {
618 web_set_lang(&line[17]);
619 }
620 /* ignore all other requests! */
621 }
622
623 if (auth_required && !authenticated) {
624 cgi_auth_error();
625 }
626
627 if (!url) {
628 cgi_setup_error("400 Bad Request", "",
629 "You must specify a GET or POST request");
630 }
631
632 /* trim the URL */
633 if ((p = strchr_m(url,' ')) || (p=strchr_m(url,'\t'))) {
634 *p = 0;
635 }
636 while (*url && strchr_m("\r\n",url[strlen(url)-1])) {
637 url[strlen(url)-1] = 0;
638 }
639
640 /* anything following a ? in the URL is part of the query string */
641 if ((p=strchr_m(url,'?'))) {
642 query_string = p+1;
643 *p = 0;
644 }
645
646 string_sub(url, "/swat/", "", 0);
647
648 if (url[0] != '/' && strstr(url,"..")==0) {
649 cgi_download(url);
650 }
651
652 printf("HTTP/1.0 200 OK\r\nConnection: close\r\n");
653 printf("Date: %s\r\n", http_timestring(talloc_tos(), time(NULL)));
654 baseurl = "";
655 pathinfo = url+1;
656}
657
658
659/***************************************************************************
660return the current pages URL
661 ***************************************************************************/
662const char *cgi_baseurl(void)
663{
664 if (inetd_server) {
665 return baseurl;
666 }
667 return getenv("SCRIPT_NAME");
668}
669
670/***************************************************************************
671return the current pages path info
672 ***************************************************************************/
673const char *cgi_pathinfo(void)
674{
675 char *r;
676 if (inetd_server) {
677 return pathinfo;
678 }
679 r = getenv("PATH_INFO");
680 if (!r) return "";
681 if (*r == '/') r++;
682 return r;
683}
684
685/***************************************************************************
686return the hostname of the client
687 ***************************************************************************/
688const char *cgi_remote_host(void)
689{
690 if (inetd_server) {
691 return get_peer_name(1,False);
692 }
693 return getenv("REMOTE_HOST");
694}
695
696/***************************************************************************
697return the hostname of the client
698 ***************************************************************************/
699const char *cgi_remote_addr(void)
700{
701 if (inetd_server) {
702 char addr[INET6_ADDRSTRLEN];
703 get_peer_addr(1,addr,sizeof(addr));
704 return talloc_strdup(talloc_tos(), addr);
705 }
706 return getenv("REMOTE_ADDR");
707}
708
709
710/***************************************************************************
711return True if the request was a POST
712 ***************************************************************************/
713bool cgi_waspost(void)
714{
715 if (inetd_server) {
716 return request_post;
717 }
718 return strequal(getenv("REQUEST_METHOD"), "POST");
719}
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