Add the ``blacklist'' feature, which allows a path to a filename to

be used as a valid pattern in the access control language.

Patch obtained from ftp://ftp.porcupine.org/pub/security/ .

Requested by:	markm
This commit is contained in:
sheldonh 1999-09-21 09:09:57 +00:00
parent 43d88af9c1
commit 1e4516eee8
3 changed files with 65 additions and 1 deletions

View File

@ -89,6 +89,13 @@ An expression of the form `n.n.n.n/m.m.m.m\' is interpreted as a
bitwise AND of the address and the `mask\'. For example, the net/mask
pattern `131.155.72.0/255.255.254.0\' matches every address in the
range `131.155.72.0\' through `131.155.73.255\'.
.IP \(bu
A string that begins with a `/\' character is treated as a file
name. A host name or address is matched if it matches any host name
or address pattern listed in the named file. The file format is
zero or more lines with zero or more host name or address patterns
separated by whitespace. A file name pattern can be used anywhere
a host name or address pattern can be used.
.SH WILDCARDS
The access control language supports explicit wildcards:
.IP ALL
@ -326,7 +333,7 @@ in.tftpd: ALL: (/some/where/safe_finger -l @%h | \\
/usr/ucb/mail -s %d-%h root) &
.fi
.PP
The safe_finger command comes with the tcpd wrapper and should be
The safe_finger command is intended for use in back-fingering and should be
installed in a suitable place. It limits possible damage from data sent
by the remote finger server. It gives better protection than the
standard finger command.
@ -350,6 +357,12 @@ capacity of an internal buffer; when an access control rule is not
terminated by a newline character; when the result of %<letter>
expansion would overflow an internal buffer; when a system call fails
that shouldn\'t. All problems are reported via the syslog daemon.
.SH IMPLEMENTATION NOTES
Some operating systems are distributed with TCP Wrappers as part of the
base system. It is common for such systems to build wrapping functionality
into networking utilities. Notably, some systems offer an \fIinetd\fR(8)
which does not require the use of the \fItcpd\fR(8). Check your system's
documentation for details.
.SH FILES
.na
.nf
@ -376,3 +389,4 @@ Eindhoven University of Technology
Den Dolech 2, P.O. Box 513,
5600 MB Eindhoven, The Netherlands
\" @(#) hosts_access.5 1.20 95/01/30 19:51:46
\" $FreeBSD$

View File

@ -15,6 +15,8 @@
* Compile with -DNETGROUP if your library provides support for netgroups.
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*
* $FreeBSD$
*/
#ifndef lint
@ -240,6 +242,26 @@ struct request_info *request;
}
}
/* hostfile_match - look up host patterns from file */
static int hostfile_match(path, host)
char *path;
struct hosts_info *host;
{
char tok[BUFSIZ];
int match = NO;
FILE *fp;
if ((fp = fopen(path, "r")) != 0) {
while (fscanf(fp, "%s", tok) == 1 && !(match = host_match(tok, host)))
/* void */ ;
fclose(fp);
} else if (errno != ENOENT) {
tcpd_warn("open %s: %m", path);
}
return (match);
}
/* host_match - match host name and/or address against pattern */
static int host_match(tok, host)
@ -267,6 +289,8 @@ struct host_info *host;
tcpd_warn("netgroup support is disabled"); /* not tcpd_jump() */
return (NO);
#endif
} else if (tok[0] == '/') { /* /file hack */
return (hostfile_match(tok, host));
} else if (STR_EQ(tok, "KNOWN")) { /* check address and name */
char *name = eval_hostname(host);
return (STR_NE(eval_hostaddr(host), unknown) && HOSTNAME_KNOWN(name));

View File

@ -12,6 +12,8 @@
* -v: show all rules.
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*
* $FreeBSD$
*/
#ifndef lint
@ -350,6 +352,8 @@ char *pat;
{
if (pat[0] == '@') {
tcpd_warn("%s: daemon name begins with \"@\"", pat);
} else if (pat[0] == '/') {
tcpd_warn("%s: daemon name begins with \"/\"", pat);
} else if (pat[0] == '.') {
tcpd_warn("%s: daemon name begins with dot", pat);
} else if (pat[strlen(pat) - 1] == '.') {
@ -382,6 +386,8 @@ char *pat;
{
if (pat[0] == '@') { /* @netgroup */
tcpd_warn("%s: user name begins with \"@\"", pat);
} else if (pat[0] == '/') {
tcpd_warn("%s: user name begins with \"/\"", pat);
} else if (pat[0] == '.') {
tcpd_warn("%s: user name begins with dot", pat);
} else if (pat[strlen(pat) - 1] == '.') {
@ -402,8 +408,13 @@ char *pat;
static int check_host(pat)
char *pat;
{
char buf[BUFSIZ];
char *mask;
int addr_count = 1;
FILE *fp;
struct tcpd_context saved_context;
char *cp;
char *wsp = " \t\r\n";
if (pat[0] == '@') { /* @netgroup */
#ifdef NO_NETGRENT
@ -422,6 +433,21 @@ char *pat;
tcpd_warn("netgroup support disabled");
#endif
#endif
} else if (pat[0] == '/') { /* /path/name */
if ((fp = fopen(pat, "r")) != 0) {
saved_context = tcpd_context;
tcpd_context.file = pat;
tcpd_context.line = 0;
while (fgets(buf, sizeof(buf), fp)) {
tcpd_context.line++;
for (cp = strtok(buf, wsp); cp; cp = strtok((char *) 0, wsp))
check_host(cp);
}
tcpd_context = saved_context;
fclose(fp);
} else if (errno != ENOENT) {
tcpd_warn("open %s: %m", pat);
}
} else if (mask = split_at(pat, '/')) { /* network/netmask */
if (dot_quad_addr(pat) == INADDR_NONE
|| dot_quad_addr(mask) == INADDR_NONE)