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 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