Move commands into "posix", "lsb", and "other" menus/directories.

1 files changed, 246 insertions, 0 deletions

diff --git a/toys/other/login.c b/toys/other/login.c
new file mode 100644
index 00000000..c2c9ba38
--- /dev/null
+++ b/toys/other/login.c
@@ -0,0 +1,246 @@
+/* vi: set sw=4 ts=4:
+ *
+ * login.c - Start a session on the system.
+ *
+ * Copyright 2012 Elie De Brauwer <eliedebrauwer@gmail.com>
+ *
+ * Not in SUSv4.
+ * No support for PAM/securetty/selinux/login script/issue/utmp
+ * Relies on libcrypt for hash calculation.
+
+USE_LOGIN(NEWTOY(login, ">1fph:", TOYFLAG_BIN))
+
+config LOGIN
+	bool "login"
+	default y
+	help
+	  usage: login [-p] [-h host] [[-f] username]
+
+	  Establish a new session with the system.
+	  -p    Preserve environment
+	  -h    The name of the remote host for this login
+	  -f    Do not perform authentication
+*/
+
+#include "toys.h"
+
+#define LOGIN_TIMEOUT 60
+#define LOGIN_FAIL_TIMEOUT 3
+#define USER_NAME_MAX_SIZE 32
+#define HOSTNAME_SIZE 32
+
+DEFINE_GLOBALS(
+	char *hostname;
+)
+#define TT this.login
+
+static void login_timeout_handler(int sig __attribute__((unused)))
+{
+	printf("\nLogin timed out after %d seconds.\n", LOGIN_TIMEOUT);
+	exit(0);
+}
+
+static char *forbid[] = {
+	"BASH_ENV",
+	"ENV",
+	"HOME",
+	"IFS",
+	"LD_LIBRARY_PATH",
+	"LD_PRELOAD",
+	"LD_TRACE_LOADED_OBJECTS",
+	"LD_BIND_NOW",
+	"LD_AOUT_LIBRARY_PATH",
+	"LD_AOUT_PRELOAD",
+	"LD_NOWARN",
+	"LD_KEEPDIR",
+	"SHELL",
+	NULL
+};
+
+int verify_password(char * pwd)
+{
+	char *pass;
+
+	if (read_password(toybuf, sizeof(toybuf), "Password: ")) return 1;
+	if (!pwd) return 1;
+	if (pwd[0] == '!' || pwd[0] == '*') return 1;
+
+	pass = crypt(toybuf, pwd);
+	if (pass && !strcmp(pass, pwd)) return 0;
+
+	return 1;
+}
+
+void read_user(char * buff, int size)
+{
+	char hostname[HOSTNAME_SIZE+1];
+	int i = 0;
+	hostname[HOSTNAME_SIZE] = 0;
+	if(!gethostname(hostname, HOSTNAME_SIZE)) fputs(hostname, stdout);
+
+	fputs(" login: ", stdout);
+	fflush(stdout);
+
+	do {
+		buff[0] = getchar();
+		if (buff[0] == EOF)
+			exit(EXIT_FAILURE);
+	} while (isblank(buff[0]));
+
+	if (buff[0] != '\n')
+		if(!fgets(&buff[1], HOSTNAME_SIZE-1, stdin))
+			_exit(1);
+
+	while(i<HOSTNAME_SIZE-1 && isgraph(buff[i])) i++;
+	buff[i] = 0;
+}
+
+void handle_nologin(void)
+{
+	int fd = open("/etc/nologin", O_RDONLY);
+	int size;
+	if (fd == -1) return;
+
+	size = readall(fd, toybuf,sizeof(toybuf)-1);
+	toybuf[size] = 0;
+	if (!size) puts("System closed for routine maintenance\n");
+	else puts(toybuf);
+
+	close(fd);
+	fflush(stdout);
+	exit(EXIT_FAILURE);
+}
+
+void handle_motd(void)
+{
+	int fd = open("/etc/motd", O_RDONLY);
+	int size;
+	if (fd == -1) return;
+
+	size = readall(fd, toybuf,sizeof(toybuf)-1);
+	toybuf[size] = 0;
+	puts(toybuf);
+
+	close(fd);
+	fflush(stdout);
+}
+
+int change_identity(const struct passwd *pwd)
+{
+	if (initgroups(pwd->pw_name,pwd->pw_gid)) return 1;
+	if (setgid(pwd->pw_uid)) return 1;
+	if (setuid(pwd->pw_uid)) return 1;
+
+	return 0;
+}
+
+void spawn_shell(const char *shell)
+{
+	const char * exec_name = strrchr(shell,'/');
+	if (exec_name) exec_name++;
+	else exec_name = shell;
+
+	snprintf(toybuf,sizeof(toybuf)-1, "-%s", shell);
+	execl(shell, toybuf, NULL);
+	error_exit("Failed to spawn shell");
+}
+
+void setup_environment(const struct passwd *pwd, int clear_env)
+{
+	if (chdir(pwd->pw_dir)) printf("bad home dir: %s\n", pwd->pw_dir);
+
+	if (clear_env) {
+		const char * term = getenv("TERM");
+		clearenv();
+		if (term) setenv("TERM", term, 1);
+	}
+
+	setenv("USER", pwd->pw_name, 1);
+	setenv("LOGNAME", pwd->pw_name, 1);
+	setenv("HOME", pwd->pw_dir, 1);
+	setenv("SHELL", pwd->pw_shell, 1);
+}
+
+void login_main(void)
+{
+	int f_flag = (toys.optflags & 4) >> 2;
+	int p_flag = (toys.optflags & 2) >> 1;
+	int h_flag = toys.optflags & 1;
+	char username[USER_NAME_MAX_SIZE+1], *pass = NULL, **ss;
+	struct passwd * pwd = NULL;
+	struct spwd * spwd = NULL;
+	int auth_fail_cnt = 0;
+
+	if (f_flag && toys.optc != 1)
+		error_exit("-f requires username");
+
+	if (geteuid()) error_exit("not root");
+
+	if (!isatty(0) || !isatty(1) || !isatty(2)) error_exit("no tty");
+
+	openlog("login", LOG_PID | LOG_CONS, LOG_AUTH);
+	signal(SIGALRM, login_timeout_handler);
+	alarm(LOGIN_TIMEOUT);
+
+	for (ss = forbid; *ss; ss++) unsetenv(*ss);
+
+	while (1) {
+		tcflush(0, TCIFLUSH);
+
+		username[USER_NAME_MAX_SIZE] = 0;
+		if (toys.optargs[0])
+			strncpy(username, toys.optargs[0], USER_NAME_MAX_SIZE);
+		else {
+			read_user(username, USER_NAME_MAX_SIZE+1);
+			if (username[0] == 0) continue;
+		}
+
+		pwd = getpwnam(username);
+		if (!pwd) goto query_pass; // Non-existing user
+
+		if (pwd->pw_passwd[0] == '!' || pwd->pw_passwd[0] == '*')
+			goto query_pass;  // Locked account
+
+		if (f_flag) break; // Pre-authenticated
+
+		if (!pwd->pw_passwd[0]) break; // Password-less account
+
+		pass = pwd->pw_passwd;
+		if (pwd->pw_passwd[0] == 'x') {
+			spwd = getspnam (username);
+			if (spwd) pass = spwd->sp_pwdp;
+		}
+
+query_pass:
+		if (!verify_password(pass)) break;
+
+		f_flag = 0;
+		syslog(LOG_WARNING, "invalid password for '%s' on %s %s %s", username,
+			ttyname(0), (h_flag)?"from":"", (h_flag)?TT.hostname:"");
+
+		sleep(LOGIN_FAIL_TIMEOUT);
+		puts("Login incorrect");
+
+		if (++auth_fail_cnt == 3)
+			error_exit("Maximum number of tries exceeded (%d)\n", auth_fail_cnt);
+
+		username[0] = 0;
+		pwd = NULL;
+		spwd = NULL;
+	}
+
+	alarm(0);
+
+	if (pwd->pw_uid) handle_nologin();
+
+	if (change_identity(pwd)) error_exit("Failed to change identity");
+
+	setup_environment(pwd, !p_flag);
+
+	handle_motd();
+
+	syslog(LOG_INFO, "%s logged in on %s %s %s", pwd->pw_name,
+		ttyname(0), (h_flag)?"from":"", (h_flag)?TT.hostname:"");
+
+	spawn_shell(pwd->pw_shell);
+}