1 /*
2 * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
3 * Use is subject to license terms.
4 */
5
6 #pragma ident "%Z%%M% %I% %E% SMI"
7
8 /*
9 * percent_x() takes a string and performs %<char> expansions. It aborts the
10 * program when the expansion would overflow the output buffer. The result
11 * of %<char> expansion may be passed on to a shell process. For this
12 * reason, characters with a special meaning to shells are replaced by
13 * underscores.
14 *
15 * Diagnostics are reported through syslog(3).
16 *
17 * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
18 */
19
20 #ifndef lint
21 static char sccsid[] = "@(#) percent_x.c 1.4 94/12/28 17:42:37";
22 #endif
23
24 /* System libraries. */
25
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <unistd.h>
29 #include <syslog.h>
30 #include <string.h>
31
32 extern void exit();
33
34 /* Local stuff. */
35
36 #include "tcpd.h"
37
38 /* percent_x - do %<char> expansion, abort if result buffer is too small */
39
percent_x(result,result_len,string,request)40 char *percent_x(result, result_len, string, request)
41 char *result;
42 int result_len;
43 char *string;
44 struct request_info *request;
45 {
46 char *bp = result;
47 char *end = result + result_len - 1; /* end of result buffer */
48 char *expansion;
49 int expansion_len;
50 static char ok_chars[] = "1234567890!@%-_=+:,./\
51 abcdefghijklmnopqrstuvwxyz\
52 ABCDEFGHIJKLMNOPQRSTUVWXYZ";
53 char *str = string;
54 char *cp;
55 int ch;
56
57 /*
58 * Warning: we may be called from a child process or after pattern
59 * matching, so we cannot use clean_exit() or tcpd_jump().
60 */
61
62 while (*str) {
63 if (*str == '%' && (ch = str[1]) != 0) {
64 str += 2;
65 expansion =
66 ch == 'a' ? eval_hostaddr(request->client) :
67 ch == 'A' ? eval_hostaddr(request->server) :
68 ch == 'c' ? eval_client(request) :
69 ch == 'd' ? eval_daemon(request) :
70 ch == 'h' ? eval_hostinfo(request->client) :
71 ch == 'H' ? eval_hostinfo(request->server) :
72 ch == 'n' ? eval_hostname(request->client) :
73 ch == 'N' ? eval_hostname(request->server) :
74 ch == 'p' ? eval_pid(request) :
75 ch == 's' ? eval_server(request) :
76 ch == 'u' ? eval_user(request) :
77 ch == '%' ? "%" : (tcpd_warn("unrecognized %%%c", ch), "");
78 for (cp = expansion; *(cp += strspn(cp, ok_chars)); /* */ )
79 *cp = '_';
80 expansion_len = cp - expansion;
81 } else {
82 expansion = str++;
83 expansion_len = 1;
84 }
85 if (bp + expansion_len >= end) {
86 tcpd_warn("percent_x: expansion too long: %.30s...", result);
87 sleep(5);
88 exit(0);
89 }
90 memcpy(bp, expansion, expansion_len);
91 bp += expansion_len;
92 }
93 *bp = 0;
94 return (result);
95 }
96