source: branches/samba-3.3.x/source/web/cgi.c@ 206

Last change on this file since 206 was 206, checked in by Herwig Bauernfeind, 16 years ago

Import Samba 3.3 branch at 3.0.0 level (psmedley's port)
File size: 17.8 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_allocate(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_allocate(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 = getpwnam_alloc(talloc_autofree_context(), user);
319 if (!pwd) {
320 printf("%sCannot find user %s<br>%s\n", head, user, tail);
321 exit(0);
322 }
323
324 setuid(0);
325 setuid(pwd->pw_uid);
326 if (geteuid() != pwd->pw_uid || getuid() != pwd->pw_uid) {
327 printf("%sFailed to become user %s - uid=%d/%d<br>%s\n",
328 head, user, (int)geteuid(), (int)getuid(), tail);
329 exit(0);
330 }
331 TALLOC_FREE(pwd);
332#endif
333}
334
335
336/***************************************************************************
337handle a http authentication line
338 ***************************************************************************/
339static bool cgi_handle_authorization(char *line)
340{
341 char *p;
342 fstring user, user_pass;
343 struct passwd *pass = NULL;
344
345 if (!strnequal(line,"Basic ", 6)) {
346 goto err;
347 }
348 line += 6;
349 while (line[0] == ' ') line++;
350 base64_decode_inplace(line);
351 if (!(p=strchr_m(line,':'))) {
352 /*
353 * Always give the same error so a cracker
354 * cannot tell why we fail.
355 */
356 goto err;
357 }
358 *p = 0;
359
360 convert_string(CH_UTF8, CH_UNIX,
361 line, -1,
362 user, sizeof(user), True);
363
364 convert_string(CH_UTF8, CH_UNIX,
365 p+1, -1,
366 user_pass, sizeof(user_pass), True);
367
368 /*
369 * Try and get the user from the UNIX password file.
370 */
371
372 pass = getpwnam_alloc(talloc_autofree_context(), user);
373
374 /*
375 * Validate the password they have given.
376 */
377
378 if NT_STATUS_IS_OK(pass_check(pass, user, user_pass,
379 strlen(user_pass), NULL, False)) {
380
381 if (pass) {
382 /*
383 * Password was ok.
384 */
385
386 if ( initgroups(pass->pw_name, pass->pw_gid) != 0 )
387 goto err;
388
389 become_user_permanently(pass->pw_uid, pass->pw_gid);
390
391 /* Save the users name */
392 C_user = SMB_STRDUP(user);
393 TALLOC_FREE(pass);
394 return True;
395 }
396 }
397
398err:
399 cgi_setup_error("401 Bad Authorization",
400 "WWW-Authenticate: Basic realm=\"SWAT\"\r\n",
401 "username or password incorrect");
402
403 TALLOC_FREE(pass);
404 return False;
405}
406
407/***************************************************************************
408is this root?
409 ***************************************************************************/
410bool am_root(void)
411{
412 if (geteuid() == 0) {
413 return( True);
414 } else {
415 return( False);
416 }
417}
418
419/***************************************************************************
420return a ptr to the users name
421 ***************************************************************************/
422char *cgi_user_name(void)
423{
424 return(C_user);
425}
426
427
428/***************************************************************************
429handle a file download
430 ***************************************************************************/
431static void cgi_download(char *file)
432{
433 SMB_STRUCT_STAT st;
434 char buf[1024];
435 int fd, l, i;
436 char *p;
437 char *lang;
438
439 /* sanitise the filename */
440 for (i=0;file[i];i++) {
441 if (!isalnum((int)file[i]) && !strchr_m("/.-_", file[i])) {
442 cgi_setup_error("404 File Not Found","",
443 "Illegal character in filename");
444 }
445 }
446
447 if (sys_stat(file, &st) != 0)
448 {
449 cgi_setup_error("404 File Not Found","",
450 "The requested file was not found");
451 }
452
453 if (S_ISDIR(st.st_mode))
454 {
455 snprintf(buf, sizeof(buf), "%s/index.html", file);
456 if (!file_exist(buf, &st) || !S_ISREG(st.st_mode))
457 {
458 cgi_setup_error("404 File Not Found","",
459 "The requested file was not found");
460 }
461 }
462 else if (S_ISREG(st.st_mode))
463 {
464 snprintf(buf, sizeof(buf), "%s", file);
465 }
466 else
467 {
468 cgi_setup_error("404 File Not Found","",
469 "The requested file was not found");
470 }
471
472 fd = web_open(buf,O_RDONLY,0);
473 if (fd == -1) {
474 cgi_setup_error("404 File Not Found","",
475 "The requested file was not found");
476 }
477 printf("HTTP/1.0 200 OK\r\n");
478 if ((p=strrchr_m(buf, '.'))) {
479 if (strcmp(p,".gif")==0) {
480 printf("Content-Type: image/gif\r\n");
481 } else if (strcmp(p,".jpg")==0) {
482 printf("Content-Type: image/jpeg\r\n");
483 } else if (strcmp(p,".png")==0) {
484 printf("Content-Type: image/png\r\n");
485 } else if (strcmp(p,".css")==0) {
486 printf("Content-Type: text/css\r\n");
487 } else if (strcmp(p,".txt")==0) {
488 printf("Content-Type: text/plain\r\n");
489 } else {
490 printf("Content-Type: text/html\r\n");
491 }
492 }
493 printf("Expires: %s\r\n", http_timestring(time(NULL)+EXPIRY_TIME));
494
495 lang = lang_tdb_current();
496 if (lang) {
497 printf("Content-Language: %s\r\n", lang);
498 }
499
500 printf("Content-Length: %d\r\n\r\n", (int)st.st_size);
501 while ((l=read(fd,buf,sizeof(buf)))>0) {
502 if (fwrite(buf, 1, l, stdout) != l) {
503 break;
504 }
505 }
506 close(fd);
507 exit(0);
508}
509
510
511
512
513/**
514 * @brief Setup the CGI framework.
515 *
516 * Setup the cgi framework, handling the possibility that this program
517 * is either run as a true CGI program with a gateway to a web server, or
518 * is itself a mini web server.
519 **/
520void cgi_setup(const char *rootdir, int auth_required)
521{
522 bool authenticated = False;
523 char line[1024];
524 char *url=NULL;
525 char *p;
526 char *lang;
527
528 if (chdir(rootdir)) {
529 cgi_setup_error("500 Server Error", "",
530 "chdir failed - the server is not configured correctly");
531 }
532
533 /* Handle the possibility we might be running as non-root */
534 sec_init();
535
536 if ((lang=getenv("HTTP_ACCEPT_LANGUAGE"))) {
537 /* if running as a cgi program */
538 web_set_lang(lang);
539 }
540
541 /* maybe we are running under a web server */
542 if (getenv("CONTENT_LENGTH") || getenv("REQUEST_METHOD")) {
543 if (auth_required) {
544 cgi_web_auth();
545 }
546 return;
547 }
548
549 inetd_server = True;
550
551 if (!check_access(1, lp_hostsallow(-1), lp_hostsdeny(-1))) {
552 cgi_setup_error("403 Forbidden", "",
553 "Samba is configured to deny access from this client\n<br>Check your \"hosts allow\" and \"hosts deny\" options in smb.conf ");
554 }
555
556 /* we are a mini-web server. We need to read the request from stdin
557 and handle authentication etc */
558 while (fgets(line, sizeof(line)-1, stdin)) {
559 if (line[0] == '\r' || line[0] == '\n') break;
560 if (strnequal(line,"GET ", 4)) {
561 got_request = True;
562 url = SMB_STRDUP(&line[4]);
563 } else if (strnequal(line,"POST ", 5)) {
564 got_request = True;
565 request_post = 1;
566 url = SMB_STRDUP(&line[5]);
567 } else if (strnequal(line,"PUT ", 4)) {
568 got_request = True;
569 cgi_setup_error("400 Bad Request", "",
570 "This server does not accept PUT requests");
571 } else if (strnequal(line,"Authorization: ", 15)) {
572 authenticated = cgi_handle_authorization(&line[15]);
573 } else if (strnequal(line,"Content-Length: ", 16)) {
574 content_length = atoi(&line[16]);
575 } else if (strnequal(line,"Accept-Language: ", 17)) {
576 web_set_lang(&line[17]);
577 }
578 /* ignore all other requests! */
579 }
580
581 if (auth_required && !authenticated) {
582 cgi_auth_error();
583 }
584
585 if (!url) {
586 cgi_setup_error("400 Bad Request", "",
587 "You must specify a GET or POST request");
588 }
589
590 /* trim the URL */
591 if ((p = strchr_m(url,' ')) || (p=strchr_m(url,'\t'))) {
592 *p = 0;
593 }
594 while (*url && strchr_m("\r\n",url[strlen(url)-1])) {
595 url[strlen(url)-1] = 0;
596 }
597
598 /* anything following a ? in the URL is part of the query string */
599 if ((p=strchr_m(url,'?'))) {
600 query_string = p+1;
601 *p = 0;
602 }
603
604 string_sub(url, "/swat/", "", 0);
605
606 if (url[0] != '/' && strstr(url,"..")==0) {
607 cgi_download(url);
608 }
609
610 printf("HTTP/1.0 200 OK\r\nConnection: close\r\n");
611 printf("Date: %s\r\n", http_timestring(time(NULL)));
612 baseurl = "";
613 pathinfo = url+1;
614}
615
616
617/***************************************************************************
618return the current pages URL
619 ***************************************************************************/
620const char *cgi_baseurl(void)
621{
622 if (inetd_server) {
623 return baseurl;
624 }
625 return getenv("SCRIPT_NAME");
626}
627
628/***************************************************************************
629return the current pages path info
630 ***************************************************************************/
631const char *cgi_pathinfo(void)
632{
633 char *r;
634 if (inetd_server) {
635 return pathinfo;
636 }
637 r = getenv("PATH_INFO");
638 if (!r) return "";
639 if (*r == '/') r++;
640 return r;
641}
642
643/***************************************************************************
644return the hostname of the client
645 ***************************************************************************/
646const char *cgi_remote_host(void)
647{
648 if (inetd_server) {
649 return get_peer_name(1,False);
650 }
651 return getenv("REMOTE_HOST");
652}
653
654/***************************************************************************
655return the hostname of the client
656 ***************************************************************************/
657const char *cgi_remote_addr(void)
658{
659 if (inetd_server) {
660 char addr[INET6_ADDRSTRLEN];
661 return get_peer_addr(1,addr,sizeof(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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