87 lines
2.3 KiB
C
87 lines
2.3 KiB
C
/*
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* percent_x() takes a string and performs %<char> expansions. It aborts the
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* program when the expansion would overflow the output buffer. The result
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* of %<char> expansion may be passed on to a shell process. For this
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* reason, characters with a special meaning to shells are replaced by
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* underscores.
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*
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* Diagnostics are reported through syslog(3).
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*
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* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
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*/
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#ifndef lint
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static char sccsid[] = "@(#) percent_x.c 1.4 94/12/28 17:42:37";
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#endif
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/* System libraries. */
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#include <stdio.h>
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#include <syslog.h>
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#include <string.h>
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extern void exit();
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/* Local stuff. */
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#include "tcpd.h"
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/* percent_x - do %<char> expansion, abort if result buffer is too small */
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char *percent_x(result, result_len, string, request)
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char *result;
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int result_len;
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char *string;
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struct request_info *request;
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{
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char *bp = result;
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char *end = result + result_len - 1; /* end of result buffer */
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char *expansion;
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int expansion_len;
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static char ok_chars[] = "1234567890!@%-_=+:,./\
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abcdefghijklmnopqrstuvwxyz\
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ABCDEFGHIJKLMNOPQRSTUVWXYZ";
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char *str = string;
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char *cp;
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int ch;
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/*
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* Warning: we may be called from a child process or after pattern
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* matching, so we cannot use clean_exit() or tcpd_jump().
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*/
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while (*str) {
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if (*str == '%' && (ch = str[1]) != 0) {
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str += 2;
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expansion =
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ch == 'a' ? eval_hostaddr(request->client) :
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ch == 'A' ? eval_hostaddr(request->server) :
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ch == 'c' ? eval_client(request) :
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ch == 'd' ? eval_daemon(request) :
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ch == 'h' ? eval_hostinfo(request->client) :
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ch == 'H' ? eval_hostinfo(request->server) :
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ch == 'n' ? eval_hostname(request->client) :
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ch == 'N' ? eval_hostname(request->server) :
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ch == 'p' ? eval_pid(request) :
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ch == 's' ? eval_server(request) :
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ch == 'u' ? eval_user(request) :
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ch == '%' ? "%" : (tcpd_warn("unrecognized %%%c", ch), "");
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for (cp = expansion; *(cp += strspn(cp, ok_chars)); /* */ )
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*cp = '_';
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expansion_len = cp - expansion;
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} else {
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expansion = str++;
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expansion_len = 1;
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}
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if (bp + expansion_len >= end) {
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tcpd_warn("percent_x: expansion too long: %.30s...", result);
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sleep(5);
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exit(0);
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}
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memcpy(bp, expansion, expansion_len);
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bp += expansion_len;
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}
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*bp = 0;
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return (result);
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}
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