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--- a/inetd.c
+++ b/inetd.c
@@ -289,6 +289,7 @@ int bump_nofile(void);
struct servtab *enter(struct servtab *);
int matchconf(struct servtab *, struct servtab *);
int dg_broadcast(struct in_addr *in);
+void discard_stupid_environment(void);
#define NUMINT (sizeof(intab) / sizeof(struct inent))
char *CONFIG = _PATH_INETDCONF;
@@ -302,14 +303,18 @@ int
main(int argc, char *argv[], char *envp[])
{
int ch;
+ int keepenv = 0;
initsetproctitle(argc, argv, envp);
- while ((ch = getopt(argc, argv, "dR:")) != -1)
+ while ((ch = getopt(argc, argv, "dER:")) != -1)
switch (ch) {
case 'd':
debug = 1;
break;
+ case 'E':
+ keepenv = 1;
+ break;
case 'R': { /* invocation rate */
char *p;
int val;
@@ -326,12 +331,16 @@ main(int argc, char *argv[], char *envp[
}
default:
fprintf(stderr,
- "usage: inetd [-d] [-R rate] [configuration_file]\n");
+ "usage: inetd [-dE] [-R rate] [configuration_file]\n");
exit(1);
}
argc -= optind;
argv += optind;
+ /* This must be called _after_ initsetproctitle and arg parsing */
+ if (!keepenv)
+ discard_stupid_environment();
+
uid = getuid();
if (uid != 0)
CONFIG = NULL;
@@ -1888,3 +1897,45 @@ spawn(int ctrl, short events, void *xsep
if (!sep->se_wait && sep->se_socktype == SOCK_STREAM)
close(ctrl);
}
+
+/* from netkit+USAGI */
+void
+discard_stupid_environment(void)
+{
+ static const char *const junk[] = {
+ /* these are prefixes */
+ "CVS",
+ "DISPLAY=",
+ "EDITOR=",
+ "GROUP=",
+ "HOME=",
+ "IFS=",
+ "LD_",
+ "LOGNAME=",
+ "MAIL=",
+ "PATH=",
+ "PRINTER=",
+ "PWD=",
+ "SHELL=",
+ "SHLVL=",
+ "SSH",
+ "TERM",
+ "TMP",
+ "USER=",
+ "VISUAL=",
+ NULL
+ };
+
+ int i, k = 0;
+
+ for (i = 0; __environ[i]; i++) {
+ int found = 0, j;
+
+ for (j = 0; junk[j]; j++)
+ if (!strncmp(__environ[i], junk[j], strlen(junk[j])))
+ found = 1;
+ if (!found)
+ __environ[k++] = __environ[i];
+ }
+ __environ[k] = NULL;
+}
--- a/inetd.8
+++ b/inetd.8
@@ -38,6 +38,7 @@
.Sh SYNOPSIS
.Nm inetd
.Op Fl d
+.Op Fl E
.Op Fl R Ar rate
.Op Ar configuration_file
.Sh DESCRIPTION
@@ -58,6 +59,13 @@ The options are as follows:
.Bl -tag -width Ds
.It Fl d
Turns on debugging.
+.It Fl E
+Prevents
+.Nm inetd
+from laundering the environment. Without this option a selection of
+potentially harmful environment variables, including
+.Pa PATH ,
+will be removed and not inherited by services.
.It Fl R Ar rate
Specify the maximum number of times a service can be invoked
in one minute; the default is 256.
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