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/**
* cerberus – Minimal login program
*
* Copyright © 2013 Mattias Andrée (maandree@member.fsf.org)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <pwd.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include "config.h"
#include "login.h"
/**
* The environment variables
*/
extern char** environ;
/**
* Set the user gid and uid
*
* @param entry The user entry in the password file
*/
void set_user(struct passwd* entry)
{
if (setgid(entry->pw_gid) && entry->pw_gid)
{
perror("setgid");
_exit(1);
}
if (setuid(entry->pw_uid) && entry->pw_uid)
{
perror("setuid");
_exit(1);
}
}
/**
* Change directory to the user's home directory
*
* @param entry The user entry in the password file
*/
void chdir_home(struct passwd* entry)
{
if (chdir(entry->pw_dir))
{
perror("chdir");
if (chdir(DEFAULT_HOME))
{
perror("chdir");
sleep(ERROR_SLEEP);
_exit(1);
}
entry->pw_dir = DEFAULT_HOME;
}
}
/**
* Make sure the shell to use is definied
*
* @param entry The user entry in the password file
*/
void ensure_shell(struct passwd* entry)
{
if ((entry->pw_shell && *(entry->pw_shell)) == 0)
entry->pw_shell = DEFAULT_SHELL;
}
/**
* Set environment variables
*
* @param entry The user entry in the password file
* @param preserve_env Whether to preserve the environment
*/
void set_environ(struct passwd* entry, char preserve_env)
{
char* _term = getenv("TERM");
char* term = NULL;
if (_term)
{
int n = 0, i;
while (*(_term + n++))
;
term = malloc(n * sizeof(char));
if (term == NULL)
{
perror("malloc");
sleep(ERROR_SLEEP);
_exit(1);
}
for (i = 0; i < n; i++)
*(term + i) = *(_term + i);
}
if (preserve_env == 0)
{
environ = malloc(sizeof(char*));
if (environ == NULL)
{
perror("malloc");
sleep(ERROR_SLEEP);
_exit(1);
}
*environ = NULL;
}
setenv("HOME", entry->pw_dir, 1);
setenv("USER", entry->pw_name, 1);
setenv("LOGUSER", entry->pw_name, 1);
setenv("SHELL", entry->pw_shell, 1);
setenv("TERM", term ?: DEFAULT_TERM, 1);
setenv("PATH", entry->pw_uid ? PATH : PATH_ROOT, 1);
if (term)
free(term);
}
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