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Improve execsh() and don't allow anonymous shells

This patch improves the shell selection on execsh and forbid
shell with users don't registered in the passwd file.
Roberto E. Vargas Caballero hace 10 años
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commit
a3549c2eec
Se han modificado 1 ficheros con 17 adiciones y 13 borrados
  1. 17 13
      st.c

+ 17 - 13
st.c

@@ -1139,23 +1139,29 @@ die(const char *errstr, ...) {
 
 void
 execsh(void) {
-	char **args;
-	char *envshell = getenv("SHELL");
-	const struct passwd *pass = getpwuid(getuid());
+	char **args, *sh;
+	const struct passwd *pw;
 	char buf[sizeof(long) * 8 + 1];
 
+	errno = 0;
+	if((pw = getpwuid(getuid())) == NULL) {
+		if(errno)
+			die("getpwuid:%s\n", strerror(errno));
+		else
+			die("who are you?\n");
+	}
 	unsetenv("COLUMNS");
 	unsetenv("LINES");
 	unsetenv("TERMCAP");
 
-	if(pass) {
-		setenv("LOGNAME", pass->pw_name, 1);
-		setenv("USER", pass->pw_name, 1);
-		setenv("SHELL", pass->pw_shell, 0);
-		setenv("HOME", pass->pw_dir, 0);
-	}
-
+	sh = (pw->pw_shell[0]) ? pw->pw_shell : shell;
 	snprintf(buf, sizeof(buf), "%lu", xw.win);
+
+	setenv("LOGNAME", pw->pw_name, 1);
+	setenv("USER", pw->pw_name, 1);
+	setenv("SHELL", sh, 1);
+	setenv("HOME", pw->pw_dir, 1);
+	setenv("TERM", termname, 1);
 	setenv("WINDOWID", buf, 1);
 
 	signal(SIGCHLD, SIG_DFL);
@@ -1165,9 +1171,7 @@ execsh(void) {
 	signal(SIGTERM, SIG_DFL);
 	signal(SIGALRM, SIG_DFL);
 
-	DEFAULT(envshell, shell);
-	setenv("TERM", termname, 1);
-	args = opt_cmd ? opt_cmd : (char *[]){envshell, "-i", NULL};
+	args = opt_cmd ? opt_cmd : (char *[]){sh, "-i", NULL};
 	execvp(args[0], args);
 	exit(EXIT_FAILURE);
 }