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/*
** generic wrapper that will take info from a environment
** variable, and pass it to two commands.
**
** 10-17-96 : Hal Schechner
** 12-14-96 : John Viega -- changed to work on 1 command,
** take a list of valid commands,
** just pass on argv, and use execvp()
** Also threw in some useful feedback for when there's
** a failure, mainly for future debugging.
**
** 03-31-98 : John Viega -- Consolidated all CGI wrappers into 1,
** removed checking the command name, (it was
** not real security anyway...) and changed it to use
** syslog on error. This definitely doesn't have any of
** Hal's code left ;-)
**
*/
#include <stdio.h>
#include <stdarg.h>
#include <syslog.h>
#define COMMAND "/home/mailman/mailman/cgi/" ## SCRIPT
#define LOG_IDENT "Mailman-wrapper (" ## SCRIPT ## ")"
const int LEGAL_PARENT_UID = 60001; /* nobody's UID */
const int LEGAL_PARENT_GID = 60001; /* nobody's GID */
/*
** Report an error then exit.
*/
void err(char *format, ...)
{
char log_entry[1024];
va_list arg_ptr;
va_start(arg_ptr, format);
vsprintf(log_entry, format, arg_ptr);
va_end(arg_ptr);
// Write to the console, maillog is often mostly ignored,
// and root should definitely know about any problems.
openlog(LOG_IDENT, LOG_CONS, LOG_MAIL);
syslog(LOG_ERR, "%s", log_entry);
closelog();
exit(0);
}
/*
** is the parent process allowed to call us?
*/
void check_caller() {
/* compare to our parent's uid */
if(LEGAL_PARENT_UID != getuid())
{
err("Attempt to exec cgi %s made by uid %d", LEGAL_PARENT_UID,
getuid());
}
if(LEGAL_PARENT_GID != getgid())
{
err("Attempt to exec cgi %s made by gid %d", LEGAL_PARENT_GID,
getgid());
}
}
void main(int argc, char **argv, char **env)
{
int i;
check_caller();
// If we get here, the caller is OK.
setuid(geteuid());
execve(COMMAND, &argv[0], env);
err("execve of %s failed!", COMMAND);
}
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