>Synopsis domains beginning with numbers are incorrectly parsed in
>dhcpd.conf
>Category: system
>Environment:
System : OpenBSD 5.5
Details : OpenBSD 5.5-stable (GENERIC) #0: Wed Jul 2 01:29:39 PDT
2014
[email protected]:/usr/src/sys/arch/i386/compile/GENERIC
Architecture: OpenBSD.i386
Machine : i386
>Description:
A domain component which begins with a number is incorrectly parsed as
two tokens - the first being a number, and the second a number/name - confusing
the parser which then expects a dot.
This leads to a parser configuration error, and then a hostname lookup
error since it then looks up the wrong hostname.
>How-To-Repeat:
Add the following to dhcpd.conf:
option domain-name-servers ns.87k.net;
dhcpd exits with a parse error.
>Fix:
The following patch addresses this issue by appending identifiers
following numbers to the domain component:
Index: usr.sbin/dhcpd/parse.c
===================================================================
RCS file: /cvs/src/usr.sbin/dhcpd/parse.c,v
retrieving revision 1.17
diff -u -p -r1.17 parse.c
--- usr.sbin/dhcpd/parse.c 18 Dec 2013 20:37:04 -0000 1.17
+++ usr.sbin/dhcpd/parse.c 7 Jul 2014 04:23:15 -0000
@@ -148,15 +148,28 @@ parse_host_name(FILE *cfile)
do {
/* Read a token, which should be an identifier. */
token = next_token(&val, cfile);
- if (!is_identifier(token) && token != TOK_NUMBER) {
+ if (is_identifier(token)) {
+ s = strdup(val);
+ if (s == NULL)
+ error("can't allocate temp space for
hostname.");
+ } else if (token == TOK_NUMBER) {
+ t = strdup(val);
+ if (t == NULL)
+ error("can't allocate temp space for hostname");
+ token = peek_token(&val, cfile);
+ if (is_identifier(token)) {
+ token = next_token(&val, cfile);
+ if (-1 == asprintf(&s, "%s%s", t, val))
+ error("can't allocate temp space for
hostname");
+ free(t);
+ } else
+ s = t;
+ } else {
parse_warn("expecting an identifier in hostname");
skip_to_semi(cfile);
return (NULL);
}
/* Store this identifier... */
- s = strdup(val);
- if (s == NULL)
- error("can't allocate temp space for hostname.");
c = cons((caddr_t) s, c);
len += strlen(s) + 1;
/*
