X-Git-Url: https://ruderich.org/simon/gitweb/?p=ptyas%2Fptyas.git;a=blobdiff_plain;f=ptyas.c;h=d650f1858f0843ac56747354cd8c4bef3291113b;hp=d87ae34738e2f8321f6df618b81737db894d4365;hb=85cbaa83752955830f80daec2d801c551cb603b7;hpb=0178c35881746d366a225b932f519f992035f24c

diff --git a/ptyas.c b/ptyas.c
index d87ae34..d650f18 100644
--- a/ptyas.c
+++ b/ptyas.c
@@ -2,7 +2,7 @@
  * Run the login shell or command as the given user in a new pty to prevent
  * terminal injection attacks.
  *
- * Copyright (C) 2016-2018  Simon Ruderich
+ * Copyright (C) 2016-2019  Simon Ruderich
  *
  * 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
@@ -286,6 +286,28 @@ static void sigchld_handler(int signal) {
     }
 }
 
+/*
+ * SIGWINCH handler to handle resizes of the outer terminal.
+ *
+ * Errors are ignored without message because printing in signal handlers is
+ * problematic (no FILE * usable due to locks) and there's not much we can do
+ * at this point.
+ */
+static int sigwinch_ctty = -1;
+static int sigwinch_slave = -1;
+
+static void sigwinch_handler(int signal) {
+    (void)signal;
+
+    struct winsize size;
+    if (ioctl(sigwinch_ctty, TIOCGWINSZ, &size) == -1) {
+        return;
+    }
+    if (ioctl(sigwinch_slave, TIOCSWINSZ, &size) == -1) {
+        return;
+    }
+}
+
 
 int main(int argc, char **argv) {
     char *exec_argv_shell[] = { NULL, NULL }; /* filled below */
@@ -422,7 +444,18 @@ int main(int argc, char **argv) {
         }
         quit_with_matching_code(status);
     }
-    close_or_die(pty_slave);
+    /* Don't close pty_slave here as it's used in sigwinch_handler(). */
+
+    sigwinch_ctty = ctty;
+    sigwinch_slave = pty_slave;
+
+    struct sigaction action_sigwinch = {
+        .sa_handler = sigwinch_handler,
+    };
+    sigemptyset(&action_sigwinch.sa_mask);
+    if (sigaction(SIGWINCH, &action_sigwinch, NULL) != 0) {
+        die("sigaction SIGWINCH");
+    }
 
     pid_to_wait_for = pid;
     struct sigaction action_sigchld = {