From b5896ba9f6047e7031e2bdee0622d543e11a6734 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Mon, 6 May 2024 03:46:30 +0200 Subject: Adding upstream version 3.4.23. Signed-off-by: Daniel Baumann --- src/util/clean_env.c | 128 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 128 insertions(+) create mode 100644 src/util/clean_env.c (limited to 'src/util/clean_env.c') diff --git a/src/util/clean_env.c b/src/util/clean_env.c new file mode 100644 index 0000000..c6daffa --- /dev/null +++ b/src/util/clean_env.c @@ -0,0 +1,128 @@ +/*++ +/* NAME +/* clean_env 3 +/* SUMMARY +/* clean up the environment +/* SYNOPSIS +/* #include +/* +/* void clean_env(preserve_list) +/* const char **preserve_list; +/* +/* void update_env(preserve_list) +/* const char **preserve_list; +/* DESCRIPTION +/* clean_env() reduces the process environment to the bare minimum. +/* The function takes a null-terminated list of arguments. +/* Each argument specifies the name of an environment variable +/* that should be preserved, or specifies a name=value that should +/* be entered into the new environment. +/* +/* update_env() applies name=value settings, but otherwise does not +/* change the process environment. +/* DIAGNOSTICS +/* Fatal error: out of memory. +/* SEE ALSO +/* safe_getenv(3), guarded getenv() +/* LICENSE +/* .ad +/* .fi +/* The Secure Mailer license must be distributed with this software. +/* AUTHOR(S) +/* Wietse Venema +/* IBM T.J. Watson Research +/* P.O. Box 704 +/* Yorktown Heights, NY 10598, USA +/* +/* Wietse Venema +/* Google, Inc. +/* 111 8th Avenue +/* New York, NY 10011, USA +/*--*/ + +/* System library. */ + +#include +#include +#include +#include + +/* Utility library. */ + +#include +#include +#include +#include + +/* clean_env - clean up the environment */ + +void clean_env(char **preserve_list) +{ + extern char **environ; + ARGV *save_list; + char *value; + char **cpp; + char *eq; + + /* + * Preserve or specify selected environment variables. + */ +#define STRING_AND_LENGTH(x, y) (x), (ssize_t) (y) + + save_list = argv_alloc(10); + for (cpp = preserve_list; *cpp; cpp++) + if ((eq = strchr(*cpp, '=')) != 0) + argv_addn(save_list, STRING_AND_LENGTH(*cpp, eq - *cpp), + STRING_AND_LENGTH(eq + 1, strlen(eq + 1)), (char *) 0); + else if ((value = safe_getenv(*cpp)) != 0) + argv_add(save_list, *cpp, value, (char *) 0); + + /* + * Truncate the process environment, if available. On some systems + * (Ultrix!), environ can be a null pointer. + */ + if (environ) + environ[0] = 0; + + /* + * Restore preserved environment variables. + */ + for (cpp = save_list->argv; *cpp; cpp += 2) + if (setenv(cpp[0], cpp[1], 1)) + msg_fatal("setenv(%s, %s): %m", cpp[0], cpp[1]); + + /* + * Cleanup. + */ + argv_free(save_list); +} + +/* update_env - apply name=value settings only */ + +void update_env(char **preserve_list) +{ + char **cpp; + ARGV *save_list; + char *eq; + + /* + * Extract name=value settings. + */ + save_list = argv_alloc(10); + for (cpp = preserve_list; *cpp; cpp++) + if ((eq = strchr(*cpp, '=')) != 0) + argv_addn(save_list, STRING_AND_LENGTH(*cpp, eq - *cpp), + STRING_AND_LENGTH(eq + 1, strlen(eq + 1)), (char *) 0); + + /* + * Apply name=value settings. + */ + for (cpp = save_list->argv; *cpp; cpp += 2) + if (setenv(cpp[0], cpp[1], 1)) + msg_fatal("setenv(%s, %s): %m", cpp[0], cpp[1]); + + /* + * Cleanup. + */ + argv_free(save_list); +} -- cgit v1.2.3