isa/sudo
1
0
Fork 0
Code Issues Pull Requests Actions 1 Packages Projects Releases Wiki Activity

Don't try to pre-compute the size of the new envp, just allocate

Browse Source 
space up front and realloc as needed.  Changes to the new env pointer
must all be made through insert_env() which now keeps track of
spaced used and allocates as needed.
This commit is contained in:
Todd C. Miller
2002-05-02 19:40:25 +00:00
parent 4160f7eb70
commit 3f7d801880
1 changed files with 57 additions and 63 deletions
Download Patch File Download Diff File Expand all files Collapse all files

120
env.c
View File

@@ -1,5 +1,5 @@
/*
* Copyright (c) 2000, 2001 Todd C. Miller <Todd.Miller@courtesan.com>
* Copyright (c) 2000-2002 Todd C. Miller <Todd.Miller@courtesan.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@@ -86,14 +86,14 @@ static const char rcsid[] = "$Sudo$";
*/
char **rebuild_env __P((int, char **));
char **zero_env __P((char **));
static void insert_env __P((char **, char *));
static void insert_env __P((char *, int));
static char *format_env __P((char *, char *));
/*
* Default table of "bad" variables to remove from the environment.
* XXX - how to omit TERMCAP if it starts with '/'?
*/
char *initial_badenv_table[] = {
static const char *initial_badenv_table[] = {
"IFS",
"LOCALDOMAIN",
"RES_OPTIONS",
@@ -133,13 +133,17 @@ char *initial_badenv_table[] = {
/*
* Default table of variables to check for '%' and '/' characters.
*/
char *initial_checkenv_table[] = {
static const char *initial_checkenv_table[] = {
"LC_*",
"LANG",
"LANGUAGE",
NULL
};
static char **new_environ; /* Modified copy of the environment */
static size_t env_size; /* size of new_environ in char **'s */
static size_t env_len; /* number of slots used, not counting NULL */
/*
* Zero out environment and replace with a minimal set of
* USER, LOGNAME, HOME, TZ, PATH (XXX - should just set path to default)
@@ -221,29 +225,38 @@ format_env(var, val)
}
/*
* Insert str into envp.
* Assumes str has an '=' in it and does not check for available space!
* Insert str into new_environ, assumes str has an '=' in it.
* NOTE: no other routines may modify new_environ, env_size, or env_len.
*/
static void
insert_env(envp, str)
char **envp;
insert_env(str, dupcheck)
char *str;
int dupcheck;
{
char **ep;
char **nep;
size_t varlen;
varlen = (strchr(str, '=') - str) + 1;
/* Make sure there is room for the new entry. */
if (env_len + 1 > env_size) {
env_size += 128;
new_environ = erealloc(new_environ, env_size * sizeof(char *));
}
for (ep = envp; *ep; ep++) {
if (strncmp(str, *ep, varlen) == 0) {
*ep = str;
break;
}
}
if (*ep == NULL) {
*ep++ = str;
*ep = NULL;
}
if (dupcheck) {
varlen = (strchr(str, '=') - str) + 1;
for (nep = new_environ; *nep; nep++) {
if (strncmp(str, *nep, varlen) == 0) {
*nep = str;
return;
}
}
} else
nep = &new_environ[env_len];
env_len++;
*nep++ = str;
*nep = NULL;
}
/*
@@ -256,15 +269,11 @@ rebuild_env(sudo_mode, envp)
int sudo_mode;
char **envp;
{
char **newenvp, **ep, **nep, *cp, *ps1;
char **ep, *cp, *ps1;
int okvar, iswild, didvar;
size_t env_size, len;
size_t len;
struct list_member *cur;
/* Count number of items in "env_keep" list (if any) */
for (len = 0, cur = def_list(I_ENV_KEEP); cur; cur = cur->next)
len++;
/*
* Either clean out the environment or reset to a safe default.
*/
@@ -273,10 +282,6 @@ rebuild_env(sudo_mode, envp)
if (def_flag(I_ENV_RESET)) {
int keepit;
/* Alloc space for new environment. */
env_size = 32 + len;
nep = newenvp = (char **) emalloc(env_size * sizeof(char *));
/* Pull in vars we want to keep from the old environment. */
for (ep = envp; *ep; ep++) {
keepit = 0;
@@ -321,14 +326,14 @@ rebuild_env(sudo_mode, envp)
didvar |= DID_USER;
break;
}
*nep++ = *ep;
insert_env(*ep, 0);
} else {
/* Preserve TERM and PATH, ignore anything else. */
if (!(didvar & DID_TERM) && !strncmp(*ep, "TERM=", 5)) {
*nep++ = *ep;
insert_env(*ep, 0);
didvar |= DID_TERM;
} else if (!(didvar & DID_PATH) && !strncmp(*ep, "PATH=", 5)) {
*nep++ = *ep;
insert_env(*ep, 0);
didvar |= DID_PATH;
}
}
@@ -339,19 +344,14 @@ rebuild_env(sudo_mode, envp)
* user's environment.
*/
if (!(didvar & DID_HOME))
*nep++ = format_env("HOME", user_dir);
insert_env(format_env("HOME", user_dir), 0);
if (!(didvar & DID_SHELL))
*nep++ = format_env("SHELL", sudo_user.pw->pw_shell);
insert_env(format_env("SHELL", sudo_user.pw->pw_shell), 0);
if (!(didvar & DID_LOGNAME))
*nep++ = format_env("LOGNAME", user_name);
insert_env(format_env("LOGNAME", user_name), 0);
if (!(didvar & DID_USER))
*nep++ = format_env("USER", user_name);
insert_env(format_env("USER", user_name), 0);
} else {
/* Alloc space for new environment. */
for (env_size = 16 + len, ep = envp; *ep; ep++, env_size++)
;
nep = newenvp = (char **) emalloc(env_size * sizeof(char *));
/*
* Copy envp entries as long as they don't match env_delete or
* env_check.
@@ -397,56 +397,50 @@ rebuild_env(sudo_mode, envp)
didvar |= DID_PATH;
else if (strncmp(*ep, "TERM=", 5) == 0)
didvar |= DID_TERM;
*nep++ = *ep;
insert_env(*ep, 0);
}
}
}
/* Provide default values for $TERM and $PATH if they are not set. */
if (!(didvar & DID_TERM))
*nep++ = "TERM=unknown";
insert_env("TERM=unknown", 0);
if (!(didvar & DID_PATH))
*nep++ = format_env("PATH", _PATH_DEFPATH);
*nep = NULL;
/*
* At this point we must use insert_env() to modify newenvp.
* Access via 'nep' is not allowed (since we must check for dupes).
*/
insert_env(format_env("PATH", _PATH_DEFPATH), 0);
#ifdef SECURE_PATH
/* Replace the PATH envariable with a secure one. */
insert_env(newenvp, format_env("PATH", SECURE_PATH));
insert_env(format_env("PATH", SECURE_PATH), 1);
#endif
/* Set $USER and $LOGNAME to target if "set_logname" is true. */
if (def_flag(I_SET_LOGNAME) && runas_pw->pw_name) {
insert_env(newenvp, format_env("LOGNAME", runas_pw->pw_name));
insert_env(newenvp, format_env("USER", runas_pw->pw_name));
insert_env(format_env("LOGNAME", runas_pw->pw_name), 1);
insert_env(format_env("USER", runas_pw->pw_name), 1);
}
/* Set $HOME for `sudo -H'. Only valid at PERM_RUNAS. */
if ((sudo_mode & MODE_RESET_HOME) && runas_pw->pw_dir)
insert_env(newenvp, format_env("HOME", runas_pw->pw_dir));
insert_env(format_env("HOME", runas_pw->pw_dir), 1);
/* Set PS1 if SUDO_PS1 is set. */
if (ps1)
insert_env(newenvp, ps1);
insert_env(ps1, 1);
/* Add the SUDO_COMMAND envariable (cmnd + args). */
if (user_args) {
easprintf(&cp, "SUDO_COMMAND=%s %s", user_cmnd, user_args);
insert_env(newenvp, cp);
insert_env(cp, 1);
} else
insert_env(newenvp, format_env("SUDO_COMMAND", user_cmnd));
insert_env(format_env("SUDO_COMMAND", user_cmnd), 1);
/* Add the SUDO_USER, SUDO_UID, SUDO_GID environment variables. */
insert_env(newenvp, format_env("SUDO_USER", user_name));
insert_env(format_env("SUDO_USER", user_name), 1);
easprintf(&cp, "SUDO_UID=%ld", (long) user_uid);
insert_env(newenvp, cp);
insert_env(cp, 1);
easprintf(&cp, "SUDO_GID=%ld", (long) user_gid);
insert_env(newenvp, cp);
insert_env(cp, 1);
return(newenvp);
return(new_environ);
}
void
@@ -467,7 +461,7 @@ void
init_envtables()
{
struct list_member *cur;
char **p;
const char **p;
/* Fill in "env_delete" variable. */
for (p = initial_badenv_table; *p; p++) {