source: vendor/3.5.4/source3/web/cgi.c

Last change on this file was 414, checked in by Herwig Bauernfeind, 16 years ago

Samba 3.5.0: Initial import
File size: 17.2 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
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 pwd = getpwnam_alloc(talloc_autofree_context(), user);
318 if (!pwd) {
319 printf("%sCannot find user %s<br>%s\n", head, user, tail);
320 exit(0);
321 }
322
323 setuid(0);
324 setuid(pwd->pw_uid);
325 if (geteuid() != pwd->pw_uid || getuid() != pwd->pw_uid) {
326 printf("%sFailed to become user %s - uid=%d/%d<br>%s\n",
327 head, user, (int)geteuid(), (int)getuid(), tail);
328 exit(0);
329 }
330 TALLOC_FREE(pwd);
331}
332
333
334/***************************************************************************
335handle a http authentication line
336 ***************************************************************************/
337static bool cgi_handle_authorization(char *line)
338{
339 char *p;
340 fstring user, user_pass;
341 struct passwd *pass = NULL;
342
343 if (!strnequal(line,"Basic ", 6)) {
344 goto err;
345 }
346 line += 6;
347 while (line[0] == ' ') line++;
348 base64_decode_inplace(line);
349 if (!(p=strchr_m(line,':'))) {
350 /*
351 * Always give the same error so a cracker
352 * cannot tell why we fail.
353 */
354 goto err;
355 }
356 *p = 0;
357
358 convert_string(CH_UTF8, CH_UNIX,
359 line, -1,
360 user, sizeof(user), True);
361
362 convert_string(CH_UTF8, CH_UNIX,
363 p+1, -1,
364 user_pass, sizeof(user_pass), True);
365
366 /*
367 * Try and get the user from the UNIX password file.
368 */
369
370 pass = getpwnam_alloc(talloc_autofree_context(), user);
371
372 /*
373 * Validate the password they have given.
374 */
375
376 if NT_STATUS_IS_OK(pass_check(pass, user, user_pass,
377 strlen(user_pass), NULL, False)) {
378
379 if (pass) {
380 /*
381 * Password was ok.
382 */
383
384 if ( initgroups(pass->pw_name, pass->pw_gid) != 0 )
385 goto err;
386
387 become_user_permanently(pass->pw_uid, pass->pw_gid);
388
389 /* Save the users name */
390 C_user = SMB_STRDUP(user);
391 TALLOC_FREE(pass);
392 return True;
393 }
394 }
395
396err:
397 cgi_setup_error("401 Bad Authorization",
398 "WWW-Authenticate: Basic realm=\"SWAT\"\r\n",
399 "username or password incorrect");
400
401 TALLOC_FREE(pass);
402 return False;
403}
404
405/***************************************************************************
406is this root?
407 ***************************************************************************/
408bool am_root(void)
409{
410 if (geteuid() == 0) {
411 return( True);
412 } else {
413 return( False);
414 }
415}
416
417/***************************************************************************
418return a ptr to the users name
419 ***************************************************************************/
420char *cgi_user_name(void)
421{
422 return(C_user);
423}
424
425
426/***************************************************************************
427handle a file download
428 ***************************************************************************/
429static void cgi_download(char *file)
430{
431 SMB_STRUCT_STAT st;
432 char buf[1024];
433 int fd, l, i;
434 char *p;
435 char *lang;
436
437 /* sanitise the filename */
438 for (i=0;file[i];i++) {
439 if (!isalnum((int)file[i]) && !strchr_m("/.-_", file[i])) {
440 cgi_setup_error("404 File Not Found","",
441 "Illegal character in filename");
442 }
443 }
444
445 if (sys_stat(file, &st, false) != 0) {
446 cgi_setup_error("404 File Not Found","",
447 "The requested file was not found");
448 }
449
450 if (S_ISDIR(st.st_ex_mode))
451 {
452 snprintf(buf, sizeof(buf), "%s/index.html", file);
453 if (!file_exist_stat(buf, &st, false)
454 || !S_ISREG(st.st_ex_mode))
455 {
456 cgi_setup_error("404 File Not Found","",
457 "The requested file was not found");
458 }
459 }
460 else if (S_ISREG(st.st_ex_mode))
461 {
462 snprintf(buf, sizeof(buf), "%s", file);
463 }
464 else
465 {
466 cgi_setup_error("404 File Not Found","",
467 "The requested file was not found");
468 }
469
470 fd = web_open(buf,O_RDONLY,0);
471 if (fd == -1) {
472 cgi_setup_error("404 File Not Found","",
473 "The requested file was not found");
474 }
475 printf("HTTP/1.0 200 OK\r\n");
476 if ((p=strrchr_m(buf, '.'))) {
477 if (strcmp(p,".gif")==0) {
478 printf("Content-Type: image/gif\r\n");
479 } else if (strcmp(p,".jpg")==0) {
480 printf("Content-Type: image/jpeg\r\n");
481 } else if (strcmp(p,".png")==0) {
482 printf("Content-Type: image/png\r\n");
483 } else if (strcmp(p,".css")==0) {
484 printf("Content-Type: text/css\r\n");
485 } else if (strcmp(p,".txt")==0) {
486 printf("Content-Type: text/plain\r\n");
487 } else {
488 printf("Content-Type: text/html\r\n");
489 }
490 }
491 printf("Expires: %s\r\n",
492 http_timestring(talloc_tos(), time(NULL)+EXPIRY_TIME));
493
494 lang = lang_tdb_current();
495 if (lang) {
496 printf("Content-Language: %s\r\n", lang);
497 }
498
499 printf("Content-Length: %d\r\n\r\n", (int)st.st_ex_size);
500 while ((l=read(fd,buf,sizeof(buf)))>0) {
501 if (fwrite(buf, 1, l, stdout) != l) {
502 break;
503 }
504 }
505 close(fd);
506 exit(0);
507}
508
509
510
511
512/**
513 * @brief Setup the CGI framework.
514 *
515 * Setup the cgi framework, handling the possibility that this program
516 * is either run as a true CGI program with a gateway to a web server, or
517 * is itself a mini web server.
518 **/
519void cgi_setup(const char *rootdir, int auth_required)
520{
521 bool authenticated = False;
522 char line[1024];
523 char *url=NULL;
524 char *p;
525 char *lang;
526
527 if (chdir(rootdir)) {
528 cgi_setup_error("500 Server Error", "",
529 "chdir failed - the server is not configured correctly");
530 }
531
532 /* Handle the possibility we might be running as non-root */
533 sec_init();
534
535 if ((lang=getenv("HTTP_ACCEPT_LANGUAGE"))) {
536 /* if running as a cgi program */
537 web_set_lang(lang);
538 }
539
540 /* maybe we are running under a web server */
541 if (getenv("CONTENT_LENGTH") || getenv("REQUEST_METHOD")) {
542 if (auth_required) {
543 cgi_web_auth();
544 }
545 return;
546 }
547
548 inetd_server = True;
549
550 if (!check_access(1, lp_hostsallow(-1), lp_hostsdeny(-1))) {
551 cgi_setup_error("403 Forbidden", "",
552 "Samba is configured to deny access from this client\n<br>Check your \"hosts allow\" and \"hosts deny\" options in smb.conf ");
553 }
554
555 /* we are a mini-web server. We need to read the request from stdin
556 and handle authentication etc */
557 while (fgets(line, sizeof(line)-1, stdin)) {
558 if (line[0] == '\r' || line[0] == '\n') break;
559 if (strnequal(line,"GET ", 4)) {
560 got_request = True;
561 url = SMB_STRDUP(&line[4]);
562 } else if (strnequal(line,"POST ", 5)) {
563 got_request = True;
564 request_post = 1;
565 url = SMB_STRDUP(&line[5]);
566 } else if (strnequal(line,"PUT ", 4)) {
567 got_request = True;
568 cgi_setup_error("400 Bad Request", "",
569 "This server does not accept PUT requests");
570 } else if (strnequal(line,"Authorization: ", 15)) {
571 authenticated = cgi_handle_authorization(&line[15]);
572 } else if (strnequal(line,"Content-Length: ", 16)) {
573 content_length = atoi(&line[16]);
574 } else if (strnequal(line,"Accept-Language: ", 17)) {
575 web_set_lang(&line[17]);
576 }
577 /* ignore all other requests! */
578 }
579
580 if (auth_required && !authenticated) {
581 cgi_auth_error();
582 }
583
584 if (!url) {
585 cgi_setup_error("400 Bad Request", "",
586 "You must specify a GET or POST request");
587 }
588
589 /* trim the URL */
590 if ((p = strchr_m(url,' ')) || (p=strchr_m(url,'\t'))) {
591 *p = 0;
592 }
593 while (*url && strchr_m("\r\n",url[strlen(url)-1])) {
594 url[strlen(url)-1] = 0;
595 }
596
597 /* anything following a ? in the URL is part of the query string */
598 if ((p=strchr_m(url,'?'))) {
599 query_string = p+1;
600 *p = 0;
601 }
602
603 string_sub(url, "/swat/", "", 0);
604
605 if (url[0] != '/' && strstr(url,"..")==0) {
606 cgi_download(url);
607 }
608
609 printf("HTTP/1.0 200 OK\r\nConnection: close\r\n");
610 printf("Date: %s\r\n", http_timestring(talloc_tos(), time(NULL)));
611 baseurl = "";
612 pathinfo = url+1;
613}
614
615
616/***************************************************************************
617return the current pages URL
618 ***************************************************************************/
619const char *cgi_baseurl(void)
620{
621 if (inetd_server) {
622 return baseurl;
623 }
624 return getenv("SCRIPT_NAME");
625}
626
627/***************************************************************************
628return the current pages path info
629 ***************************************************************************/
630const char *cgi_pathinfo(void)
631{
632 char *r;
633 if (inetd_server) {
634 return pathinfo;
635 }
636 r = getenv("PATH_INFO");
637 if (!r) return "";
638 if (*r == '/') r++;
639 return r;
640}
641
642/***************************************************************************
643return the hostname of the client
644 ***************************************************************************/
645const char *cgi_remote_host(void)
646{
647 if (inetd_server) {
648 return get_peer_name(1,False);
649 }
650 return getenv("REMOTE_HOST");
651}
652
653/***************************************************************************
654return the hostname of the client
655 ***************************************************************************/
656const char *cgi_remote_addr(void)
657{
658 if (inetd_server) {
659 char addr[INET6_ADDRSTRLEN];
660 get_peer_addr(1,addr,sizeof(addr));
661 return talloc_strdup(talloc_tos(), addr);
662 }
663 return getenv("REMOTE_ADDR");
664}
665
666
667/***************************************************************************
668return True if the request was a POST
669 ***************************************************************************/
670bool cgi_waspost(void)
671{
672 if (inetd_server) {
673 return request_post;
674 }
675 return strequal(getenv("REQUEST_METHOD"), "POST");
676}
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