source: branches/samba-3.0/source/web/cgi.c

Last change on this file was 119, checked in by Paul Smedley, 18 years ago

No need to change user on OS2 when running as Apache cgi
File size: 16.8 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 2 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, write to the Free Software
17 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18*/
19
20
21#include "includes.h"
22#include "web/swat_proto.h"
23
24#define MAX_VARIABLES 10000
25
26/* set the expiry on fixed pages */
27#define EXPIRY_TIME (60*60*24*7)
28
29#ifdef DEBUG_COMMENTS
30extern void print_title(char *fmt, ...);
31#endif
32
33struct cgi_var {
34 char *name;
35 char *value;
36};
37
38static struct cgi_var variables[MAX_VARIABLES];
39static int num_variables;
40static int content_length;
41static int request_post;
42static char *query_string;
43static const char *baseurl;
44static char *pathinfo;
45static char *C_user;
46static BOOL inetd_server;
47static BOOL got_request;
48
49static char *grab_line(FILE *f, int *cl)
50{
51 char *ret = NULL;
52 int i = 0;
53 int len = 0;
54
55 while ((*cl)) {
56 int c;
57
58 if (i == len) {
59 char *ret2;
60 if (len == 0) len = 1024;
61 else len *= 2;
62 ret2 = (char *)SMB_REALLOC_KEEP_OLD_ON_ERROR(ret, len);
63 if (!ret2) return ret;
64 ret = ret2;
65 }
66
67 c = fgetc(f);
68 (*cl)--;
69
70 if (c == EOF) {
71 (*cl) = 0;
72 break;
73 }
74
75 if (c == '\r') continue;
76
77 if (strchr_m("\n&", c)) break;
78
79 ret[i++] = c;
80
81 }
82
83 if (ret) {
84 ret[i] = 0;
85 }
86 return ret;
87}
88
89/**
90 URL encoded strings can have a '+', which should be replaced with a space
91
92 (This was in rfc1738_unescape(), but that broke the squid helper)
93**/
94
95static void plus_to_space_unescape(char *buf)
96{
97 char *p=buf;
98
99 while ((p=strchr_m(p,'+')))
100 *p = ' ';
101}
102
103/***************************************************************************
104 load all the variables passed to the CGI program. May have multiple variables
105 with the same name and the same or different values. Takes a file parameter
106 for simulating CGI invocation eg loading saved preferences.
107 ***************************************************************************/
108void cgi_load_variables(void)
109{
110 static char *line;
111 char *p, *s, *tok;
112 int len, i;
113 FILE *f = stdin;
114
115#ifdef DEBUG_COMMENTS
116 char dummy[100]="";
117 print_title(dummy);
118 d_printf("<!== Start dump in cgi_load_variables() %s ==>\n",__FILE__);
119#endif
120
121 if (!content_length) {
122 p = getenv("CONTENT_LENGTH");
123 len = p?atoi(p):0;
124 } else {
125 len = content_length;
126 }
127
128
129 if (len > 0 &&
130 (request_post ||
131 ((s=getenv("REQUEST_METHOD")) &&
132 strequal(s,"POST")))) {
133 while (len && (line=grab_line(f, &len))) {
134 p = strchr_m(line,'=');
135 if (!p) continue;
136
137 *p = 0;
138
139 variables[num_variables].name = SMB_STRDUP(line);
140 variables[num_variables].value = SMB_STRDUP(p+1);
141
142 SAFE_FREE(line);
143
144 if (!variables[num_variables].name ||
145 !variables[num_variables].value)
146 continue;
147
148 plus_to_space_unescape(variables[num_variables].value);
149 rfc1738_unescape(variables[num_variables].value);
150 plus_to_space_unescape(variables[num_variables].name);
151 rfc1738_unescape(variables[num_variables].name);
152
153#ifdef DEBUG_COMMENTS
154 printf("<!== POST var %s has value \"%s\" ==>\n",
155 variables[num_variables].name,
156 variables[num_variables].value);
157#endif
158
159 num_variables++;
160 if (num_variables == MAX_VARIABLES) break;
161 }
162 }
163
164 fclose(stdin);
165 open("/dev/null", O_RDWR);
166
167 if ((s=query_string) || (s=getenv("QUERY_STRING"))) {
168 for (tok=strtok(s,"&;");tok;tok=strtok(NULL,"&;")) {
169 p = strchr_m(tok,'=');
170 if (!p) continue;
171
172 *p = 0;
173
174 variables[num_variables].name = SMB_STRDUP(tok);
175 variables[num_variables].value = SMB_STRDUP(p+1);
176
177 if (!variables[num_variables].name ||
178 !variables[num_variables].value)
179 continue;
180
181 plus_to_space_unescape(variables[num_variables].value);
182 rfc1738_unescape(variables[num_variables].value);
183 plus_to_space_unescape(variables[num_variables].name);
184 rfc1738_unescape(variables[num_variables].name);
185
186#ifdef DEBUG_COMMENTS
187 printf("<!== Commandline var %s has value \"%s\" ==>\n",
188 variables[num_variables].name,
189 variables[num_variables].value);
190#endif
191 num_variables++;
192 if (num_variables == MAX_VARIABLES) break;
193 }
194
195 }
196#ifdef DEBUG_COMMENTS
197 printf("<!== End dump in cgi_load_variables() ==>\n");
198#endif
199
200 /* variables from the client are in UTF-8 - convert them
201 to our internal unix charset before use */
202 for (i=0;i<num_variables;i++) {
203 pstring dest;
204
205 convert_string(CH_UTF8, CH_UNIX,
206 variables[i].name, -1,
207 dest, sizeof(dest), True);
208 free(variables[i].name);
209 variables[i].name = SMB_STRDUP(dest);
210
211 convert_string(CH_UTF8, CH_UNIX,
212 variables[i].value, -1,
213 dest, sizeof(dest), True);
214 free(variables[i].value);
215 variables[i].value = SMB_STRDUP(dest);
216 }
217}
218
219
220/***************************************************************************
221 find a variable passed via CGI
222 Doesn't quite do what you think in the case of POST text variables, because
223 if they exist they might have a value of "" or even " ", depending on the
224 browser. Also doesn't allow for variables[] containing multiple variables
225 with the same name and the same or different values.
226 ***************************************************************************/
227
228const char *cgi_variable(const char *name)
229{
230 int i;
231
232 for (i=0;i<num_variables;i++)
233 if (strcmp(variables[i].name, name) == 0)
234 return variables[i].value;
235 return NULL;
236}
237
238/***************************************************************************
239 Version of the above that can't return a NULL pointer.
240***************************************************************************/
241
242const char *cgi_variable_nonull(const char *name)
243{
244 const char *var = cgi_variable(name);
245 if (var) {
246 return var;
247 } else {
248 return "";
249 }
250}
251
252/***************************************************************************
253tell a browser about a fatal error in the http processing
254 ***************************************************************************/
255static void cgi_setup_error(const char *err, const char *header, const char *info)
256{
257 if (!got_request) {
258 /* damn browsers don't like getting cut off before they give a request */
259 char line[1024];
260 while (fgets(line, sizeof(line)-1, stdin)) {
261 if (strnequal(line,"GET ", 4) ||
262 strnequal(line,"POST ", 5) ||
263 strnequal(line,"PUT ", 4)) {
264 break;
265 }
266 }
267 }
268
269 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);
270 fclose(stdin);
271 fclose(stdout);
272 exit(0);
273}
274
275
276/***************************************************************************
277tell a browser about a fatal authentication error
278 ***************************************************************************/
279static void cgi_auth_error(void)
280{
281 if (inetd_server) {
282 cgi_setup_error("401 Authorization Required",
283 "WWW-Authenticate: Basic realm=\"SWAT\"\r\n",
284 "You must be authenticated to use this service");
285 } else {
286 printf("Content-Type: text/html\r\n");
287
288 printf("\r\n<HTML><HEAD><TITLE>SWAT</TITLE></HEAD>\n");
289 printf("<BODY><H1>Installation Error</H1>\n");
290 printf("SWAT must be installed via inetd. It cannot be run as a CGI script<p>\n");
291 printf("</BODY></HTML>\r\n");
292 }
293 exit(0);
294}
295
296/***************************************************************************
297authenticate when we are running as a CGI
298 ***************************************************************************/
299static void cgi_web_auth(void)
300{
301 const char *user = getenv("REMOTE_USER");
302 struct passwd *pwd;
303 const char *head = "Content-Type: text/html\r\n\r\n<HTML><BODY><H1>SWAT installation Error</H1>\n";
304 const char *tail = "</BODY></HTML>\r\n";
305
306 if (!user) {
307 printf("%sREMOTE_USER not set. Not authenticated by web server.<br>%s\n",
308 head, tail);
309 exit(0);
310 }
311
312#ifndef __OS2__
313 pwd = getpwnam_alloc(NULL, user);
314 if (!pwd) {
315 printf("%sCannot find user %s<br>%s\n", head, user, tail);
316 exit(0);
317 }
318
319 setuid(0);
320 setuid(pwd->pw_uid);
321 if (geteuid() != pwd->pw_uid || getuid() != pwd->pw_uid) {
322 printf("%sFailed to become user %s - uid=%d/%d<br>%s\n",
323 head, user, (int)geteuid(), (int)getuid(), tail);
324 exit(0);
325 }
326 TALLOC_FREE(pwd);
327#endif
328}
329
330
331/***************************************************************************
332handle a http authentication line
333 ***************************************************************************/
334static BOOL cgi_handle_authorization(char *line)
335{
336 char *p;
337 fstring user, user_pass;
338 struct passwd *pass = NULL;
339
340 if (!strnequal(line,"Basic ", 6)) {
341 goto err;
342 }
343 line += 6;
344 while (line[0] == ' ') line++;
345 base64_decode_inplace(line);
346 if (!(p=strchr_m(line,':'))) {
347 /*
348 * Always give the same error so a cracker
349 * cannot tell why we fail.
350 */
351 goto err;
352 }
353 *p = 0;
354
355 convert_string(CH_UTF8, CH_UNIX,
356 line, -1,
357 user, sizeof(user), True);
358
359 convert_string(CH_UTF8, CH_UNIX,
360 p+1, -1,
361 user_pass, sizeof(user_pass), True);
362
363 /*
364 * Try and get the user from the UNIX password file.
365 */
366
367 pass = getpwnam_alloc(NULL, user);
368
369 /*
370 * Validate the password they have given.
371 */
372
373 if NT_STATUS_IS_OK(pass_check(pass, user, user_pass,
374 strlen(user_pass), NULL, False)) {
375
376 if (pass) {
377 /*
378 * Password was ok.
379 */
380
381 if ( initgroups(pass->pw_name, pass->pw_gid) != 0 )
382 goto err;
383
384 become_user_permanently(pass->pw_uid, pass->pw_gid);
385
386 /* Save the users name */
387 C_user = SMB_STRDUP(user);
388 TALLOC_FREE(pass);
389 return True;
390 }
391 }
392
393err:
394 cgi_setup_error("401 Bad Authorization",
395 "WWW-Authenticate: Basic realm=\"SWAT\"\r\n",
396 "username or password incorrect");
397
398 TALLOC_FREE(pass);
399 return False;
400}
401
402/***************************************************************************
403is this root?
404 ***************************************************************************/
405BOOL am_root(void)
406{
407 if (geteuid() == 0) {
408 return( True);
409 } else {
410 return( False);
411 }
412}
413
414/***************************************************************************
415return a ptr to the users name
416 ***************************************************************************/
417char *cgi_user_name(void)
418{
419 return(C_user);
420}
421
422
423/***************************************************************************
424handle a file download
425 ***************************************************************************/
426static void cgi_download(char *file)
427{
428 SMB_STRUCT_STAT st;
429 char buf[1024];
430 int fd, l, i;
431 char *p;
432 char *lang;
433
434 /* sanitise the filename */
435 for (i=0;file[i];i++) {
436 if (!isalnum((int)file[i]) && !strchr_m("/.-_", file[i])) {
437 cgi_setup_error("404 File Not Found","",
438 "Illegal character in filename");
439 }
440 }
441
442 if (sys_stat(file, &st) != 0)
443 {
444 cgi_setup_error("404 File Not Found","",
445 "The requested file was not found");
446 }
447
448 if (S_ISDIR(st.st_mode))
449 {
450 snprintf(buf, sizeof(buf), "%s/index.html", file);
451 if (!file_exist(buf, &st) || !S_ISREG(st.st_mode))
452 {
453 cgi_setup_error("404 File Not Found","",
454 "The requested file was not found");
455 }
456 }
457 else if (S_ISREG(st.st_mode))
458 {
459 snprintf(buf, sizeof(buf), "%s", file);
460 }
461 else
462 {
463 cgi_setup_error("404 File Not Found","",
464 "The requested file was not found");
465 }
466
467 fd = web_open(buf,O_RDONLY,0);
468 if (fd == -1) {
469 cgi_setup_error("404 File Not Found","",
470 "The requested file was not found");
471 }
472 printf("HTTP/1.0 200 OK\r\n");
473 if ((p=strrchr_m(buf, '.'))) {
474 if (strcmp(p,".gif")==0) {
475 printf("Content-Type: image/gif\r\n");
476 } else if (strcmp(p,".jpg")==0) {
477 printf("Content-Type: image/jpeg\r\n");
478 } else if (strcmp(p,".png")==0) {
479 printf("Content-Type: image/png\r\n");
480 } else if (strcmp(p,".css")==0) {
481 printf("Content-Type: text/css\r\n");
482 } else if (strcmp(p,".txt")==0) {
483 printf("Content-Type: text/plain\r\n");
484 } else {
485 printf("Content-Type: text/html\r\n");
486 }
487 }
488 printf("Expires: %s\r\n", http_timestring(time(NULL)+EXPIRY_TIME));
489
490 lang = lang_tdb_current();
491 if (lang) {
492 printf("Content-Language: %s\r\n", lang);
493 }
494
495 printf("Content-Length: %d\r\n\r\n", (int)st.st_size);
496 while ((l=read(fd,buf,sizeof(buf)))>0) {
497 fwrite(buf, 1, l, stdout);
498 }
499 close(fd);
500 exit(0);
501}
502
503
504
505
506/**
507 * @brief Setup the CGI framework.
508 *
509 * Setup the cgi framework, handling the possibility that this program
510 * is either run as a true CGI program with a gateway to a web server, or
511 * is itself a mini web server.
512 **/
513void cgi_setup(const char *rootdir, int auth_required)
514{
515 BOOL authenticated = False;
516 char line[1024];
517 char *url=NULL;
518 char *p;
519 char *lang;
520
521 if (chdir(rootdir)) {
522 cgi_setup_error("500 Server Error", "",
523 "chdir failed - the server is not configured correctly");
524 }
525
526 /* Handle the possibility we might be running as non-root */
527 sec_init();
528
529 if ((lang=getenv("HTTP_ACCEPT_LANGUAGE"))) {
530 /* if running as a cgi program */
531 web_set_lang(lang);
532 }
533
534 /* maybe we are running under a web server */
535 if (getenv("CONTENT_LENGTH") || getenv("REQUEST_METHOD")) {
536 if (auth_required) {
537 cgi_web_auth();
538 }
539 return;
540 }
541
542 inetd_server = True;
543
544 if (!check_access(1, lp_hostsallow(-1), lp_hostsdeny(-1))) {
545 cgi_setup_error("403 Forbidden", "",
546 "Samba is configured to deny access from this client\n<br>Check your \"hosts allow\" and \"hosts deny\" options in smb.conf ");
547 }
548
549 /* we are a mini-web server. We need to read the request from stdin
550 and handle authentication etc */
551 while (fgets(line, sizeof(line)-1, stdin)) {
552 if (line[0] == '\r' || line[0] == '\n') break;
553 if (strnequal(line,"GET ", 4)) {
554 got_request = True;
555 url = SMB_STRDUP(&line[4]);
556 } else if (strnequal(line,"POST ", 5)) {
557 got_request = True;
558 request_post = 1;
559 url = SMB_STRDUP(&line[5]);
560 } else if (strnequal(line,"PUT ", 4)) {
561 got_request = True;
562 cgi_setup_error("400 Bad Request", "",
563 "This server does not accept PUT requests");
564 } else if (strnequal(line,"Authorization: ", 15)) {
565 authenticated = cgi_handle_authorization(&line[15]);
566 } else if (strnequal(line,"Content-Length: ", 16)) {
567 content_length = atoi(&line[16]);
568 } else if (strnequal(line,"Accept-Language: ", 17)) {
569 web_set_lang(&line[17]);
570 }
571 /* ignore all other requests! */
572 }
573
574 if (auth_required && !authenticated) {
575 cgi_auth_error();
576 }
577
578 if (!url) {
579 cgi_setup_error("400 Bad Request", "",
580 "You must specify a GET or POST request");
581 }
582
583 /* trim the URL */
584 if ((p = strchr_m(url,' ')) || (p=strchr_m(url,'\t'))) {
585 *p = 0;
586 }
587 while (*url && strchr_m("\r\n",url[strlen(url)-1])) {
588 url[strlen(url)-1] = 0;
589 }
590
591 /* anything following a ? in the URL is part of the query string */
592 if ((p=strchr_m(url,'?'))) {
593 query_string = p+1;
594 *p = 0;
595 }
596
597 string_sub(url, "/swat/", "", 0);
598
599 if (url[0] != '/' && strstr(url,"..")==0) {
600 cgi_download(url);
601 }
602
603 printf("HTTP/1.0 200 OK\r\nConnection: close\r\n");
604 printf("Date: %s\r\n", http_timestring(time(NULL)));
605 baseurl = "";
606 pathinfo = url+1;
607}
608
609
610/***************************************************************************
611return the current pages URL
612 ***************************************************************************/
613const char *cgi_baseurl(void)
614{
615 if (inetd_server) {
616 return baseurl;
617 }
618 return getenv("SCRIPT_NAME");
619}
620
621/***************************************************************************
622return the current pages path info
623 ***************************************************************************/
624const char *cgi_pathinfo(void)
625{
626 char *r;
627 if (inetd_server) {
628 return pathinfo;
629 }
630 r = getenv("PATH_INFO");
631 if (!r) return "";
632 if (*r == '/') r++;
633 return r;
634}
635
636/***************************************************************************
637return the hostname of the client
638 ***************************************************************************/
639char *cgi_remote_host(void)
640{
641 if (inetd_server) {
642 return get_peer_name(1,False);
643 }
644 return getenv("REMOTE_HOST");
645}
646
647/***************************************************************************
648return the hostname of the client
649 ***************************************************************************/
650char *cgi_remote_addr(void)
651{
652 if (inetd_server) {
653 return get_peer_addr(1);
654 }
655 return getenv("REMOTE_ADDR");
656}
657
658
659/***************************************************************************
660return True if the request was a POST
661 ***************************************************************************/
662BOOL cgi_waspost(void)
663{
664 if (inetd_server) {
665 return request_post;
666 }
667 return strequal(getenv("REQUEST_METHOD"), "POST");
668}
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