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NetBSD/usr.sbin/tcpdchk/inetcf.c

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/*
* Routines to parse an inetd.conf or tlid.conf file. This would be a great
* job for a PERL script.
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#ifndef lint
static char sccsid[] = "@(#) inetcf.c 1.6 96/02/11 17:01:29";
#endif
#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
extern int errno;
extern void exit();
#include "tcpd.h"
#include "inetcf.h"
/*
* Programs that use libwrap directly are not in inetd.conf, and so must
* be added here in a similar format. (We pretend we found them in
* /etc/inetd.conf.) Each one is a set of three strings that correspond
* to fields in /etc/inetd.conf:
* protocol (field 3), path (field 6), arg0 (field 7)
* The last entry should be a NULL.
*/
char *uses_libwrap[] = {
"tcp", "/usr/sbin/sendmail", "sendmail",
(char *) NULL
};
/*
* Network configuration files may live in unusual places. Here are some
* guesses. Shorter names follow longer ones.
*/
char *inet_files[] = {
"/private/etc/inetd.conf", /* NEXT */
"/etc/inet/inetd.conf", /* SYSV4 */
"/usr/etc/inetd.conf", /* IRIX?? */
"/etc/inetd.conf", /* BSD */
"/etc/net/tlid.conf", /* SYSV4?? */
"/etc/saf/tlid.conf", /* SYSV4?? */
"/etc/tlid.conf", /* SYSV4?? */
0,
};
static void inet_chk();
static char *base_name();
/*
* Structure with everything we know about a service.
*/
struct inet_ent {
struct inet_ent *next;
int type;
char name[1];
};
static struct inet_ent *inet_list = 0;
static char whitespace[] = " \t\r\n";
/* inet_conf - read in and examine inetd.conf (or tlid.conf) entries */
char *inet_cfg(conf)
char *conf;
{
char buf[BUFSIZ];
FILE *fp;
char **wrapped;
char *service;
char *protocol;
char *user;
char *path;
char *arg0;
char *arg1;
struct tcpd_context saved_context;
char *percent_m();
int i;
struct stat st;
saved_context = tcpd_context;
/*
* The inetd.conf (or tlid.conf) information is so useful that we insist
* on its availability. When no file is given run a series of educated
* guesses.
*/
if (conf != 0) {
if ((fp = fopen(conf, "r")) == 0) {
fprintf(stderr, percent_m(buf, "open %s: %m\n"), conf);
exit(1);
}
} else {
for (i = 0; inet_files[i] && (fp = fopen(inet_files[i], "r")) == 0; i++)
/* void */ ;
if (fp == 0) {
fprintf(stderr, "Cannot find your inetd.conf or tlid.conf file.\n");
fprintf(stderr, "Please specify its location.\n");
exit(1);
}
conf = inet_files[i];
check_path(conf, &st);
}
/*
* Process the list of programs that use libwrap directly.
*/
wrapped = uses_libwrap;
while (*wrapped != NULL) {
inet_chk(wrapped[0], wrapped[1], wrapped[2], "");
wrapped += 3;
}
/*
* Process the file. After the 7.0 wrapper release it became clear that
* there are many more inetd.conf formats than the 8 systems that I had
* studied. EP/IX uses a two-line specification for rpc services; HP-UX
* permits long lines to be broken with backslash-newline.
*/
tcpd_context.file = conf;
tcpd_context.line = 0;
while (xgets(buf, sizeof(buf), fp)) {
service = strtok(buf, whitespace); /* service */
if (service == 0 || *service == '#')
continue;
if (STR_NE(service, "stream") && STR_NE(service, "dgram"))
strtok((char *) 0, whitespace); /* endpoint */
protocol = strtok((char *) 0, whitespace);
(void) strtok((char *) 0, whitespace); /* wait */
if ((user = strtok((char *) 0, whitespace)) == 0)
continue;
if (user[0] == '/') { /* user */
path = user;
} else { /* path */
if ((path = strtok((char *) 0, whitespace)) == 0)
continue;
}
if (STR_EQ(path, "internal"))
continue;
if (path[strspn(path, "-0123456789")] == 0) {
/*
* ConvexOS puts RPC version numbers before path names. Jukka
* Ukkonen <ukkonen@csc.fi>.
*/
if ((path = strtok((char *) 0, whitespace)) == 0)
continue;
}
if ((arg0 = strtok((char *) 0, whitespace)) == 0) {
tcpd_warn("incomplete line");
continue;
}
if (arg0[strspn(arg0, "0123456789")] == 0) {
/*
* We're reading a tlid.conf file, the format is:
*
* ...stuff... path arg_count arguments mod_count modules
*/
if ((arg0 = strtok((char *) 0, whitespace)) == 0) {
tcpd_warn("incomplete line");
continue;
}
}
if ((arg1 = strtok((char *) 0, whitespace)) == 0)
arg1 = "";
inet_chk(protocol, path, arg0, arg1);
}
fclose(fp);
tcpd_context = saved_context;
return (conf);
}
/* inet_chk - examine one inetd.conf (tlid.conf?) entry */
static void inet_chk(protocol, path, arg0, arg1)
char *protocol;
char *path;
char *arg0;
char *arg1;
{
char daemon[BUFSIZ];
struct stat st;
int wrap_status = WR_MAYBE;
char *base_name_path = base_name(path);
char *tcpd_proc_name = (arg0[0] == '/' ? base_name(arg0) : arg0);
/*
* Always warn when the executable does not exist or when it is not
* executable.
*/
if (check_path(path, &st) < 0) {
tcpd_warn("%s: not found: %m", path);
} else if ((st.st_mode & 0100) == 0) {
tcpd_warn("%s: not executable", path);
}
/*
* Cheat on the miscd tests, nobody uses it anymore.
*/
if (STR_EQ(base_name_path, "miscd")) {
inet_set(arg0, WR_YES);
return;
}
/*
* While we are here...
*/
if (STR_EQ(tcpd_proc_name, "rexd") || STR_EQ(tcpd_proc_name, "rpc.rexd"))
tcpd_warn("%s may be an insecure service", tcpd_proc_name);
/*
* The tcpd program gets most of the attention.
*/
if (STR_EQ(base_name_path, "tcpd")) {
if (STR_EQ(tcpd_proc_name, "tcpd"))
tcpd_warn("%s is recursively calling itself", tcpd_proc_name);
wrap_status = WR_YES;
/*
* Check: some sites install the wrapper set-uid.
*/
if ((st.st_mode & 06000) != 0)
tcpd_warn("%s: file is set-uid or set-gid", path);
/*
* Check: some sites insert tcpd in inetd.conf, instead of replacing
* the daemon pathname.
*/
if (arg0[0] == '/' && STR_EQ(tcpd_proc_name, base_name(arg1)))
tcpd_warn("%s inserted before %s", path, arg0);
/*
* Check: make sure files exist and are executable. On some systems
* the network daemons are set-uid so we cannot complain. Note that
* tcpd takes the basename only in case of absolute pathnames.
*/
if (arg0[0] == '/') { /* absolute path */
if (check_path(arg0, &st) < 0) {
tcpd_warn("%s: not found: %m", arg0);
} else if ((st.st_mode & 0100) == 0) {
tcpd_warn("%s: not executable", arg0);
}
} else { /* look in REAL_DAEMON_DIR */
sprintf(daemon, "%s/%s", REAL_DAEMON_DIR, arg0);
if (check_path(daemon, &st) < 0) {
tcpd_warn("%s: not found in %s: %m",
arg0, REAL_DAEMON_DIR);
} else if ((st.st_mode & 0100) == 0) {
tcpd_warn("%s: not executable", daemon);
}
}
} else {
/*
* No tcpd program found. Perhaps they used the "simple installation"
* recipe. Look for a file with the same basename in REAL_DAEMON_DIR.
* Draw some conservative conclusions when a distinct file is found.
*/
sprintf(daemon, "%s/%s", REAL_DAEMON_DIR, arg0);
if (STR_EQ(path, daemon)) {
wrap_status = WR_NOT;
} else if (check_path(daemon, &st) >= 0) {
wrap_status = WR_MAYBE;
} else if (errno == ENOENT) {
wrap_status = WR_NOT;
} else {
tcpd_warn("%s: file lookup: %m", daemon);
wrap_status = WR_MAYBE;
}
}
/*
* Alas, we cannot wrap rpc/tcp services.
*/
if (wrap_status == WR_YES && STR_EQ(protocol, "rpc/tcp"))
tcpd_warn("%s: cannot wrap rpc/tcp services", tcpd_proc_name);
/* NetBSD inetd wraps all programs */
if (! STR_EQ(protocol, "rpc/tcp"))
wrap_status = WR_YES;
inet_set(tcpd_proc_name, wrap_status);
}
/* inet_set - remember service status */
void inet_set(name, type)
char *name;
int type;
{
struct inet_ent *ip =
(struct inet_ent *) malloc(sizeof(struct inet_ent) + strlen(name));
if (ip == 0) {
fprintf(stderr, "out of memory\n");
exit(1);
}
ip->next = inet_list;
strcpy(ip->name, name);
ip->type = type;
inet_list = ip;
}
/* inet_get - look up service status */
int inet_get(name)
char *name;
{
struct inet_ent *ip;
if (inet_list == 0)
return (WR_MAYBE);
for (ip = inet_list; ip; ip = ip->next)
if (STR_EQ(ip->name, name))
return (ip->type);
return (-1);
}
/* base_name - compute last pathname component */
static char *base_name(path)
char *path;
{
char *cp;
if ((cp = strrchr(path, '/')) != 0)
path = cp + 1;
return (path);
}
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