2 some simple CGI helper routines
3 Copyright (C) Andrew Tridgell 1997-1998
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.
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.
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.
24 #define MAX_VARIABLES 10000
26 /* set the expiry on fixed pages */
27 #define EXPIRY_TIME (60*60*24*7)
30 extern void print_title(char *fmt, ...);
38 static struct var variables[MAX_VARIABLES];
39 static int num_variables;
40 static int content_length;
41 static int request_post;
42 static char *query_string;
44 static char *pathinfo;
46 static BOOL inetd_server;
47 static BOOL got_request;
49 static void unescape(char *buf)
53 while ((p=strchr_m(p,'+')))
58 while (p && *p && (p=strchr_m(p,'%'))) {
62 if (c1 >= '0' && c1 <= '9')
64 else if (c1 >= 'A' && c1 <= 'F')
66 else if (c1 >= 'a' && c1 <= 'f')
70 if (c2 >= '0' && c2 <= '9')
72 else if (c2 >= 'A' && c2 <= 'F')
74 else if (c2 >= 'a' && c2 <= 'f')
80 memcpy(p+1, p+3, strlen(p+3)+1);
86 static char *grab_line(FILE *f, int *cl)
97 if (len == 0) len = 1024;
99 ret2 = (char *)Realloc(ret, len*2);
100 if (!ret2) return ret;
112 if (c == '\r') continue;
114 if (strchr_m("\n&", c)) break;
125 /***************************************************************************
126 load all the variables passed to the CGI program. May have multiple variables
127 with the same name and the same or different values. Takes a file parameter
128 for simulating CGI invocation eg loading saved preferences.
129 ***************************************************************************/
130 void cgi_load_variables(FILE *f1)
137 #ifdef DEBUG_COMMENTS
140 printf("<!== Start dump in cgi_load_variables() %s ==>\n",__FILE__);
145 if (!content_length) {
146 p = getenv("CONTENT_LENGTH");
149 len = content_length;
152 fseek(f, 0, SEEK_END);
154 fseek(f, 0, SEEK_SET);
159 (f1 || request_post ||
160 ((s=getenv("REQUEST_METHOD")) &&
161 strcasecmp(s,"POST")==0))) {
162 while (len && (line=grab_line(f, &len))) {
163 p = strchr_m(line,'=');
168 variables[num_variables].name = strdup(line);
169 variables[num_variables].value = strdup(p+1);
173 if (!variables[num_variables].name ||
174 !variables[num_variables].value)
177 unescape(variables[num_variables].value);
178 unescape(variables[num_variables].name);
180 #ifdef DEBUG_COMMENTS
181 printf("<!== POST var %s has value \"%s\" ==>\n",
182 variables[num_variables].name,
183 variables[num_variables].value);
187 if (num_variables == MAX_VARIABLES) break;
192 #ifdef DEBUG_COMMENTS
193 printf("<!== End dump in cgi_load_variables() ==>\n");
199 open("/dev/null", O_RDWR);
201 if ((s=query_string) || (s=getenv("QUERY_STRING"))) {
202 for (tok=strtok(s,"&;");tok;tok=strtok(NULL,"&;")) {
203 p = strchr_m(tok,'=');
208 variables[num_variables].name = strdup(tok);
209 variables[num_variables].value = strdup(p+1);
211 if (!variables[num_variables].name ||
212 !variables[num_variables].value)
215 unescape(variables[num_variables].value);
216 unescape(variables[num_variables].name);
218 #ifdef DEBUG_COMMENTS
219 printf("<!== Commandline var %s has value \"%s\" ==>\n",
220 variables[num_variables].name,
221 variables[num_variables].value);
224 if (num_variables == MAX_VARIABLES) break;
228 #ifdef DEBUG_COMMENTS
229 printf("<!== End dump in cgi_load_variables() ==>\n");
234 /***************************************************************************
235 find a variable passed via CGI
236 Doesn't quite do what you think in the case of POST text variables, because
237 if they exist they might have a value of "" or even " ", depending on the
238 browser. Also doesn't allow for variables[] containing multiple variables
239 with the same name and the same or different values.
240 ***************************************************************************/
241 char *cgi_variable(char *name)
245 for (i=0;i<num_variables;i++)
246 if (strcmp(variables[i].name, name) == 0)
247 return variables[i].value;
251 /***************************************************************************
252 tell a browser about a fatal error in the http processing
253 ***************************************************************************/
254 static void cgi_setup_error(char *err, char *header, char *info)
257 /* damn browsers don't like getting cut off before they give a request */
259 while (fgets(line, sizeof(line)-1, stdin)) {
260 if (strncasecmp(line,"GET ", 4)==0 ||
261 strncasecmp(line,"POST ", 5)==0 ||
262 strncasecmp(line,"PUT ", 4)==0) {
268 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 /***************************************************************************
276 tell a browser about a fatal authentication error
277 ***************************************************************************/
278 static void cgi_auth_error(void)
281 cgi_setup_error("401 Authorization Required",
282 "WWW-Authenticate: Basic realm=\"SWAT\"\r\n",
283 "You must be authenticated to use this service");
285 printf("Content-Type: text/html\r\n");
287 printf("\r\n<HTML><HEAD><TITLE>SWAT</TITLE></HEAD>\n");
288 printf("<BODY><H1>Installation Error</H1>\n");
289 printf("SWAT must be installed via inetd. It cannot be run as a CGI script<p>\n");
290 printf("</BODY></HTML>\r\n");
295 /***************************************************************************
296 authenticate when we are running as a CGI
297 ***************************************************************************/
298 static void cgi_web_auth(void)
300 char *user = getenv("REMOTE_USER");
302 char *head = "Content-Type: text/html\r\n\r\n<HTML><BODY><H1>SWAT installation Error</H1>\n";
303 char *tail = "</BODY></HTML>\r\n";
306 printf("%sREMOTE_USER not set. Not authenticated by web server.<br>%s\n",
311 pwd = getpwnam(user);
313 printf("%sCannot find user %s<br>%s\n", head, user, tail);
319 if (geteuid() != pwd->pw_uid || getuid() != pwd->pw_uid) {
320 printf("%sFailed to become user %s - uid=%d/%d<br>%s\n",
321 head, user, (int)geteuid(), (int)getuid(), tail);
326 /***************************************************************************
327 decode a base64 string in-place - simple and slow algorithm
328 ***************************************************************************/
329 static void base64_decode(char *s)
331 char *b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
332 int bit_offset, byte_offset, idx, i, n;
333 unsigned char *d = (unsigned char *)s;
338 while (*s && (p=strchr_m(b64,*s))) {
339 idx = (int)(p - b64);
340 byte_offset = (i*6)/8;
341 bit_offset = (i*6)%8;
342 d[byte_offset] &= ~((1<<(8-bit_offset))-1);
343 if (bit_offset < 3) {
344 d[byte_offset] |= (idx << (2-bit_offset));
347 d[byte_offset] |= (idx >> (bit_offset-2));
348 d[byte_offset+1] = 0;
349 d[byte_offset+1] |= (idx << (8-(bit_offset-2))) & 0xFF;
358 /***************************************************************************
359 handle a http authentication line
360 ***************************************************************************/
361 static BOOL cgi_handle_authorization(char *line)
363 char *p, *user, *user_pass;
364 struct passwd *pass = NULL;
365 BOOL got_name = False;
366 BOOL tested_pass = False;
367 fstring default_user_lookup;
368 fstring default_user_pass;
370 /* Dummy user lookup to take the same time as a valid user. */
371 fstrcpy(default_user_lookup, "zzzz bibble");
372 fstrcpy(default_user_pass, "123456789");
374 if (strncasecmp(line,"Basic ", 6)) {
378 while (line[0] == ' ') line++;
380 if (!(p=strchr_m(line,':'))) {
382 * Always give the same error so a cracker
383 * cannot tell why we fail.
392 * Try and get the user from the UNIX password file.
395 if(!(pass = Get_Pwnam(user,False))) {
397 * Always give the same error so a cracker
398 * cannot tell why we fail.
405 * Validate the password they have given.
410 if(pass_check(user, user_pass, strlen(user_pass), NULL) == True) {
416 if(pass->pw_uid != 0) {
418 * We have not authenticated as root,
419 * become the user *permanently*.
421 become_user_permanently(pass->pw_uid, pass->pw_gid);
424 /* Save the users name */
425 C_user = strdup(user);
431 /* Always take the same time. */
433 Get_Pwnam(default_user_lookup,False);
436 pass_check(default_user_lookup, default_user_pass,
437 strlen(default_user_pass), NULL);
439 cgi_setup_error("401 Bad Authorization", "",
440 "username or password incorrect");
445 /***************************************************************************
447 ***************************************************************************/
450 if (geteuid() == 0) {
457 /***************************************************************************
458 return a ptr to the users name
459 ***************************************************************************/
460 char *cgi_user_name(void)
466 /***************************************************************************
467 handle a file download
468 ***************************************************************************/
469 static void cgi_download(char *file)
476 /* sanitise the filename */
477 for (i=0;file[i];i++) {
478 if (!isalnum((int)file[i]) && !strchr_m("/.-_", file[i])) {
479 cgi_setup_error("404 File Not Found","",
480 "Illegal character in filename");
484 if (!file_exist(file, &st)) {
485 cgi_setup_error("404 File Not Found","",
486 "The requested file was not found");
488 fd = sys_open(file,O_RDONLY,0);
490 cgi_setup_error("404 File Not Found","",
491 "The requested file was not found");
493 printf("HTTP/1.0 200 OK\r\n");
494 if ((p=strrchr_m(file,'.'))) {
495 if (strcmp(p,".gif")==0) {
496 printf("Content-Type: image/gif\r\n");
497 } else if (strcmp(p,".jpg")==0) {
498 printf("Content-Type: image/jpeg\r\n");
499 } else if (strcmp(p,".txt")==0) {
500 printf("Content-Type: text/plain\r\n");
502 printf("Content-Type: text/html\r\n");
505 printf("Expires: %s\r\n", http_timestring(time(NULL)+EXPIRY_TIME));
507 printf("Content-Length: %d\r\n\r\n", (int)st.st_size);
508 while ((l=read(fd,buf,sizeof(buf)))>0) {
509 fwrite(buf, 1, l, stdout);
518 /***************************************************************************
519 setup the cgi framework, handling the possability that this program is either
520 run as a true cgi program by a web browser or is itself a mini web server
521 ***************************************************************************/
522 void cgi_setup(char *rootdir, int auth_required)
524 BOOL authenticated = False;
529 if (chdir(rootdir)) {
530 cgi_setup_error("400 Server Error", "",
531 "chdir failed - the server is not configured correctly");
534 /* maybe we are running under a web server */
535 if (getenv("CONTENT_LENGTH") || getenv("REQUEST_METHOD")) {
544 if (!check_access(1, lp_hostsallow(-1), lp_hostsdeny(-1))) {
545 cgi_setup_error("400 Server Error", "",
546 "Samba is configured to deny access from this client\n<br>Check your \"hosts allow\" and \"hosts deny\" options in smb.conf ");
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 (strncasecmp(line,"GET ", 4)==0) {
555 url = strdup(&line[4]);
556 } else if (strncasecmp(line,"POST ", 5)==0) {
559 url = strdup(&line[5]);
560 } else if (strncasecmp(line,"PUT ", 4)==0) {
562 cgi_setup_error("400 Bad Request", "",
563 "This server does not accept PUT requests");
564 } else if (strncasecmp(line,"Authorization: ", 15)==0) {
565 authenticated = cgi_handle_authorization(&line[15]);
566 } else if (strncasecmp(line,"Content-Length: ", 16)==0) {
567 content_length = atoi(&line[16]);
569 /* ignore all other requests! */
572 if (auth_required && !authenticated) {
577 cgi_setup_error("400 Bad Request", "",
578 "You must specify a GET or POST request");
582 if ((p = strchr_m(url,' ')) || (p=strchr_m(url,'\t'))) {
585 while (*url && strchr_m("\r\n",url[strlen(url)-1])) {
586 url[strlen(url)-1] = 0;
589 /* anything following a ? in the URL is part of the query string */
590 if ((p=strchr_m(url,'?'))) {
595 string_sub(url, "/swat/", "", 0);
597 if (url[0] != '/' && strstr(url,"..")==0 && file_exist(url, NULL)) {
601 printf("HTTP/1.0 200 OK\r\nConnection: close\r\n");
602 printf("Date: %s\r\n", http_timestring(time(NULL)));
608 /***************************************************************************
609 return the current pages URL
610 ***************************************************************************/
611 char *cgi_baseurl(void)
616 return getenv("SCRIPT_NAME");
619 /***************************************************************************
620 return the current pages path info
621 ***************************************************************************/
622 char *cgi_pathinfo(void)
628 r = getenv("PATH_INFO");
634 /***************************************************************************
635 return the hostname of the client
636 ***************************************************************************/
637 char *cgi_remote_host(void)
640 return get_socket_name(1);
642 return getenv("REMOTE_HOST");
645 /***************************************************************************
646 return the hostname of the client
647 ***************************************************************************/
648 char *cgi_remote_addr(void)
651 return get_socket_addr(1);
653 return getenv("REMOTE_ADDR");
657 /***************************************************************************
658 return True if the request was a POST
659 ***************************************************************************/
660 BOOL cgi_waspost(void)
665 return strequal(getenv("REQUEST_METHOD"), "POST");