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authorTheo de Raadt <deraadt@cvs.openbsd.org>1995-11-22 10:36:46 +0000
committerTheo de Raadt <deraadt@cvs.openbsd.org>1995-11-22 10:36:46 +0000
commit2fa3c62f444e27104aa4a499d4b9283805df343f (patch)
tree709b9b22cb0cedace5cd058ac8697a8d2e9fe527 /lib/libc
parent9ff875535da229cc0584e41befdf4c6514328fcd (diff)
fix long/u_int32_t botch; do gethostbyname() only if netgroups are going to
be used and do not abort; check for A->PTR->A loop otherwise only match on #.#.#.# addresses; do not assume !0 is 1 as in ANSI C. netbsd pr#1683 led to finding these problems.
Diffstat (limited to 'lib/libc')
-rw-r--r--lib/libc/net/rcmd.c149
1 files changed, 94 insertions, 55 deletions
diff --git a/lib/libc/net/rcmd.c b/lib/libc/net/rcmd.c
index e0310031b0e..3db3d86400b 100644
--- a/lib/libc/net/rcmd.c
+++ b/lib/libc/net/rcmd.c
@@ -57,9 +57,11 @@ static char *rcsid = "$NetBSD: rcmd.c,v 1.12 1995/06/03 22:33:34 mycroft Exp $";
#include <stdio.h>
#include <ctype.h>
#include <string.h>
+#include <syslog.h>
int __ivaliduser __P((FILE *, u_long, const char *, const char *));
-static int __icheckhost __P((u_long, const char *));
+static int __icheckhost __P((u_int32_t, const char *));
+static char *__gethostloop __P((u_int32_t));
int
rcmd(ahost, rport, locuser, remuser, cmd, fd2p)
@@ -253,7 +255,7 @@ ruserok(rhost, superuser, ruser, luser)
char **ap;
int i;
#define MAXADDRS 35
- u_long addrs[MAXADDRS + 1];
+ u_int32_t addrs[MAXADDRS + 1];
if ((hp = gethostbyname(rhost)) == NULL)
return (-1);
@@ -262,7 +264,7 @@ ruserok(rhost, superuser, ruser, luser)
addrs[i] = 0;
for (i = 0; i < MAXADDRS && addrs[i]; i++)
- if (iruserok(addrs[i], superuser, ruser, luser) == 0)
+ if (iruserok((u_long)addrs[i], superuser, ruser, luser) == 0)
return (0);
return (-1);
}
@@ -352,9 +354,9 @@ again:
* Returns 0 if ok, -1 if not ok.
*/
int
-__ivaliduser(hostf, raddr, luser, ruser)
+__ivaliduser(hostf, raddrl, luser, ruser)
FILE *hostf;
- u_long raddr;
+ u_long raddrl;
const char *luser, *ruser;
{
register char *user, *p;
@@ -362,9 +364,9 @@ __ivaliduser(hostf, raddr, luser, ruser)
char buf[MAXHOSTNAMELEN + 128]; /* host + login */
const char *auser, *ahost;
int hostok, userok;
- char rhost[MAXHOSTNAMELEN];
- struct hostent *hp;
+ char *rhost = (char *)-1;
char domain[MAXHOSTNAMELEN];
+ u_int32_t raddr = (u_int32_t)raddrl;
getdomainname(domain, sizeof(domain));
@@ -372,7 +374,8 @@ __ivaliduser(hostf, raddr, luser, ruser)
p = buf;
/* Skip lines that are too long. */
if (strchr(p, '\n') == NULL) {
- while ((ch = getc(hostf)) != '\n' && ch != EOF);
+ while ((ch = getc(hostf)) != '\n' && ch != EOF)
+ ;
continue;
}
while (*p != '\n' && *p != ' ' && *p != '\t' && *p != '\0') {
@@ -397,25 +400,24 @@ __ivaliduser(hostf, raddr, luser, ruser)
auser = *user ? user : luser;
ahost = buf;
- if ((hp = gethostbyaddr((char *) &raddr,
- sizeof(raddr), AF_INET)) == NULL) {
- abort();
- return -1;
- }
- (void) strncpy(rhost, hp->h_name, sizeof(rhost));
- rhost[sizeof(rhost) - 1] = '\0';
-
+ /*
+ * innetgr() must lookup a hostname (we do not attempt
+ * to change the semantics so that netgroups may have
+ * #.#.#.# addresses in the list.)
+ */
if (ahost[0] == '+')
switch (ahost[1]) {
case '\0':
hostok = 1;
break;
-
case '@':
- hostok = innetgr(&ahost[2], rhost, NULL,
- domain);
+ if (rhost == (char *)-1)
+ rhost = __gethostloop(raddr);
+ hostok = 0;
+ if (rhost)
+ hostok = innetgr(&ahost[2], rhost,
+ NULL, domain);
break;
-
default:
hostok = __icheckhost(raddr, &ahost[1]);
break;
@@ -425,12 +427,14 @@ __ivaliduser(hostf, raddr, luser, ruser)
case '\0':
hostok = -1;
break;
-
case '@':
- hostok = -innetgr(&ahost[2], rhost, NULL,
- domain);
+ if (rhost == (char *)-1)
+ rhost = __gethostloop(raddr);
+ hostok = 0;
+ if (rhost)
+ hostok = -innetgr(&ahost[2], rhost,
+ NULL, domain);
break;
-
default:
hostok = -__icheckhost(raddr, &ahost[1]);
break;
@@ -444,14 +448,12 @@ __ivaliduser(hostf, raddr, luser, ruser)
case '\0':
userok = 1;
break;
-
case '@':
userok = innetgr(&auser[2], NULL, ruser,
- domain);
+ domain);
break;
-
default:
- userok = strcmp(ruser, &auser[1]) == 0;
+ userok = strcmp(ruser, &auser[1]) ? 0 : 1;
break;
}
else if (auser[0] == '-')
@@ -459,59 +461,96 @@ __ivaliduser(hostf, raddr, luser, ruser)
case '\0':
userok = -1;
break;
-
case '@':
userok = -innetgr(&auser[2], NULL, ruser,
- domain);
+ domain);
break;
-
default:
- userok = -(strcmp(ruser, &auser[1]) == 0);
+ userok = strcmp(ruser, &auser[1]) ? 0 : -1;
break;
}
else
- userok = strcmp(ruser, auser) == 0;
+ userok = strcmp(ruser, auser) ? 0 : 1;
/* Check if one component did not match */
if (hostok == 0 || userok == 0)
continue;
/* Check if we got a forbidden pair */
- if (userok == -1 || hostok == -1)
- return -1;
+ if (userok <= -1 || hostok <= -1)
+ return (-1);
/* Check if we got a valid pair */
- if (hostok == 1 && userok == 1)
- return 0;
+ if (hostok >= 1 && userok >= 1)
+ return (0);
}
- return -1;
+ return (-1);
}
/*
- * Returns "true" if match, 0 if no match.
+ * Returns "true" if match, 0 if no match. If we do not find any
+ * semblance of an A->PTR->A loop, allow a simple #.#.#.# match to work.
*/
static int
__icheckhost(raddr, lhost)
- u_long raddr;
+ u_int32_t raddr;
const char *lhost;
{
register struct hostent *hp;
- register u_long laddr;
register char **pp;
+ struct in_addr in;
+
+ hp = gethostbyname(lhost);
+ if (hp != NULL) {
+ /* Spin through ip addresses. */
+ for (pp = hp->h_addr_list; *pp; ++pp)
+ if (!bcmp(&raddr, *pp, sizeof(raddr)))
+ return (1);
+ }
- /* Try for raw ip address first. */
- if (isdigit(*lhost) && (long)(laddr = inet_addr(lhost)) != -1)
- return (raddr == laddr);
-
- /* Better be a hostname. */
- if ((hp = gethostbyname(lhost)) == NULL)
- return (0);
-
- /* Spin through ip addresses. */
- for (pp = hp->h_addr_list; *pp; ++pp)
- if (!bcmp(&raddr, *pp, sizeof(u_long)))
- return (1);
-
- /* No match. */
+ in.s_addr = raddr;
+ if (strcmp(lhost, inet_ntoa(in)) == 0)
+ return (1);
return (0);
}
+
+/*
+ * Return the hostname associated with the supplied address.
+ * Do a reverse lookup as well for security. If a loop cannot
+ * be found, pack the result of inet_ntoa() into the string.
+ */
+static char *
+__gethostloop(raddr)
+ u_int32_t raddr;
+{
+ static char remotehost[MAXHOSTNAMELEN];
+ struct hostent *hp;
+ struct in_addr in;
+
+ hp = gethostbyaddr((char *) &raddr, sizeof(raddr), AF_INET);
+ if (hp == NULL)
+ return (NULL);
+
+ /*
+ * Look up the name and check that the supplied
+ * address is in the list
+ */
+ strncpy(remotehost, hp->h_name, sizeof(remotehost) - 1);
+ remotehost[sizeof(remotehost) - 1] = '\0';
+ hp = gethostbyname(remotehost);
+ if (hp == NULL)
+ return (NULL);
+
+ for (; hp->h_addr_list[0] != NULL; hp->h_addr_list++)
+ if (!bcmp(hp->h_addr_list[0], (caddr_t)&raddr, sizeof(raddr)))
+ return (remotehost);
+
+ /*
+ * either the DNS adminstrator has made a configuration
+ * mistake, or someone has attempted to spoof us
+ */
+ in.s_addr = raddr;
+ syslog(LOG_NOTICE, "rcmd: address %s not listed for host %s",
+ inet_ntoa(in), hp->h_name);
+ return (NULL);
+}