From a848231ae0f346dc7cc000973fbeb65b0894ee92 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 10 Apr 2024 21:59:03 +0200 Subject: Adding upstream version 3.8.5. Signed-off-by: Daniel Baumann --- src/util/clean_env.c | 165 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 165 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..4dfc33a --- /dev/null +++ b/src/util/clean_env.c @@ -0,0 +1,165 @@ +/*++ +/* 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 +#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 *copy; + char *key; + char *val; + const char *err; + + /* + * Preserve or specify selected environment variables. + */ + save_list = argv_alloc(10); + for (cpp = preserve_list; *cpp; cpp++) { + if (strchr(*cpp, '=') != 0) { + copy = mystrdup(*cpp); + err = split_nameval(copy, &key, &val); + if (err != 0) + msg_fatal("clean_env: %s in: %s", err, *cpp); + argv_add(save_list, key, val, (char *) 0); + myfree(copy); + } 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 *copy; + char *key; + char *val; + const char *err; + + /* + * Extract name=value settings. + */ + save_list = argv_alloc(10); + for (cpp = preserve_list; *cpp; cpp++) { + if (strchr(*cpp, '=') != 0) { + copy = mystrdup(*cpp); + err = split_nameval(copy, &key, &val); + if (err != 0) + msg_fatal("update_env: %s in: %s", err, *cpp); + argv_add(save_list, key, val, (char *) 0); + myfree(copy); + } + } + + /* + * 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); +} + +#ifdef TEST + +#include +#include + +int main(int argc, char **argv) +{ + extern char **environ; + char **cpp; + + clean_env(argv + 1); + for (cpp = environ; *cpp; cpp++) + vstream_printf("%s\n", *cpp); + vstream_fflush(VSTREAM_OUT); + exit(0); +} + +#endif -- cgit v1.2.3