1 files changed, 275 insertions, 0 deletions
diff --git a/libmisc/env.c b/libmisc/env.c
new file mode 100644
index 0000000..0b7c148
--- /dev/null
+++ b/libmisc/env.c
@@ -0,0 +1,275 @@
+/*
+ * Copyright (c) 1989 - 1992, Julianne Frances Haugh
+ * Copyright (c) 1996 - 1999, Marek Michałkiewicz
+ * Copyright (c) 2003 - 2005, Tomasz Kłoczko
+ * Copyright (c) 2008 - 2009, Nicolas François
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the copyright holders or contributors may not be used to
+ *    endorse or promote products derived from this software without
+ *    specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+ * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <config.h>
+
+#ident "$Id$"
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "prototypes.h"
+#include "defines.h"
+/*
+ * NEWENVP_STEP must be a power of two.  This is the number
+ * of (char *) pointers to allocate at a time, to avoid using
+ * realloc() too often.
+ */
+#define NEWENVP_STEP 16
+size_t newenvc = 0;
+/*@null@*/char **newenvp = NULL;
+extern char **environ;
+
+static const char *forbid[] = {
+	"_RLD_=",
+	"BASH_ENV=",		/* GNU creeping featurism strikes again... */
+	"ENV=",
+	"HOME=",
+	"IFS=",
+	"KRB_CONF=",
+	"LD_",			/* anything with the LD_ prefix */
+	"LIBPATH=",
+	"MAIL=",
+	"NLSPATH=",
+	"PATH=",
+	"SHELL=",
+	"SHLIB_PATH=",
+	(char *) 0
+};
+
+/* these are allowed, but with no slashes inside
+   (to work around security problems in GNU gettext) */
+static const char *noslash[] = {
+	"LANG=",
+	"LANGUAGE=",
+	"LC_",			/* anything with the LC_ prefix */
+	(char *) 0
+};
+
+/*
+ * initenv() must be called once before using addenv().
+ */
+void initenv (void)
+{
+	newenvp = (char **) xmalloc (NEWENVP_STEP * sizeof (char *));
+	*newenvp = NULL;
+}
+
+
+void addenv (const char *string, /*@null@*/const char *value)
+{
+	char *cp, *newstring;
+	size_t i;
+	size_t n;
+
+	if (NULL != value) {
+		size_t len = strlen (string) + strlen (value) + 2;
+		int wlen;
+		newstring = xmalloc (len);
+		wlen = snprintf (newstring, len, "%s=%s", string, value);
+		assert (wlen == (int) len -1);
+	} else {
+		newstring = xstrdup (string);
+	}
+
+	/*
+	 * Search for a '=' character within the string and if none is found
+	 * just ignore the whole string.
+	 */
+
+	cp = strchr (newstring, '=');
+	if (NULL == cp) {
+		free (newstring);
+		return;
+	}
+
+	n = (size_t) (cp - newstring);
+
+	/*
+	 * If this environment variable is already set, change its value.
+	 */
+	for (i = 0; i < newenvc; i++) {
+		if (   (strncmp (newstring, newenvp[i], n) == 0)
+		    && (('=' == newenvp[i][n]) || ('\0' == newenvp[i][n]))) {
+			break;
+		}
+	}
+
+	if (i < newenvc) {
+		free (newenvp[i]);
+		newenvp[i] = newstring;
+		return;
+	}
+
+	/*
+	 * Otherwise, save the new environment variable
+	 */
+	newenvp[newenvc++] = newstring;
+
+	/*
+	 * And extend the environment if needed.
+	 */
+
+	/*
+	 * Check whether newenvc is a multiple of NEWENVP_STEP.
+	 * If so we have to resize the vector.
+	 * the expression (newenvc & (NEWENVP_STEP - 1)) == 0
+	 * is equal to    (newenvc %  NEWENVP_STEP) == 0
+	 * as long as NEWENVP_STEP is a power of 2.
+	 */
+
+	if ((newenvc & (NEWENVP_STEP - 1)) == 0) {
+		char **__newenvp;
+		size_t newsize;
+
+		/*
+		 * If the resize operation succeeds we can
+		 * happily go on, else print a message.
+		 */
+
+		newsize = (newenvc + NEWENVP_STEP) * sizeof (char *);
+		__newenvp = (char **) realloc (newenvp, newsize);
+
+		if (NULL != __newenvp) {
+			/*
+			 * If this is our current environment, update
+			 * environ so that it doesn't point to some
+			 * free memory area (realloc() could move it).
+			 */
+			if (environ == newenvp) {
+				environ = __newenvp;
+			}
+			newenvp = __newenvp;
+		} else {
+			(void) fputs (_("Environment overflow\n"), stderr);
+			newenvc--;
+			free (newenvp[newenvc]);
+		}
+	}
+
+	/*
+	 * The last entry of newenvp must be NULL
+	 */
+
+	newenvp[newenvc] = NULL;
+}
+
+
+/*
+ * set_env - copy command line arguments into the environment
+ */
+void set_env (int argc, char *const *argv)
+{
+	int noname = 1;
+	char variable[1024];
+	char *cp;
+
+	for (; argc > 0; argc--, argv++) {
+		if (strlen (*argv) >= sizeof variable) {
+			continue;	/* ignore long entries */
+		}
+
+		cp = strchr (*argv, '=');
+		if (NULL == cp) {
+			int wlen;
+			wlen = snprintf (variable, sizeof variable, "L%d", noname);
+			assert (wlen < (int) sizeof(variable));
+			noname++;
+			addenv (variable, *argv);
+		} else {
+			const char **p;
+
+			for (p = forbid; NULL != *p; p++) {
+				if (strncmp (*argv, *p, strlen (*p)) == 0) {
+					break;
+				}
+			}
+
+			if (NULL != *p) {
+				strncpy (variable, *argv, (size_t)(cp - *argv));
+				variable[cp - *argv] = '\0';
+				printf (_("You may not change $%s\n"),
+					variable);
+				continue;
+			}
+
+			addenv (*argv, NULL);
+		}
+	}
+}
+
+/*
+ * sanitize_env - remove some nasty environment variables
+ * If you fall into a total paranoia, you should call this
+ * function for any root-setuid program or anything the user
+ * might change the environment with. 99% useless as almost
+ * all modern Unixes will handle setuid executables properly,
+ * but... I feel better with that silly precaution. -j.
+ */
+
+void sanitize_env (void)
+{
+	char **envp = environ;
+	const char **bad;
+	char **cur;
+	char **move;
+
+	for (cur = envp; NULL != *cur; cur++) {
+		for (bad = forbid; NULL != *bad; bad++) {
+			if (strncmp (*cur, *bad, strlen (*bad)) == 0) {
+				for (move = cur; NULL != *move; move++) {
+					*move = *(move + 1);
+				}
+				cur--;
+				break;
+			}
+		}
+	}
+
+	for (cur = envp; NULL != *cur; cur++) {
+		for (bad = noslash; NULL != *bad; bad++) {
+			if (strncmp (*cur, *bad, strlen (*bad)) != 0) {
+				continue;
+			}
+			if (strchr (*cur, '/') == NULL) {
+				continue;	/* OK */
+			}
+			for (move = cur; NULL != *move; move++) {
+				*move = *(move + 1);
+			}
+			cur--;
+			break;
+		}
+	}
+}
+