X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/f278d6f8b2cf652516548664d5c0d5103683c4f6..b9d7bcadee831e9b59fb785f2464a5fc1897bd1a:/unix/pty.c

diff --git a/unix/pty.c b/unix/pty.c
index 42ccec16..67addceb 100644
--- a/unix/pty.c
+++ b/unix/pty.c
@@ -1,3 +1,16 @@
+/*
+ * Pseudo-tty backend for pterm.
+ * 
+ * Unlike the other backends, data for this one is not neatly
+ * encapsulated into a data structure, because it wouldn't make
+ * sense to do so - the utmp stuff has to be done before a backend
+ * is initialised, and starting a second pterm from the same
+ * process would therefore be infeasible because privileges would
+ * already have been dropped. Hence, I haven't bothered to keep the
+ * data dynamically allocated: instead, the backend handle is just
+ * a null pointer and ignored everywhere.
+ */
+
 #define _XOPEN_SOURCE
 #define _XOPEN_SOURCE_EXTENDED
 #include <features.h>
@@ -61,16 +74,12 @@ static int pty_child_pid;
 static int pty_utmp_helper_pid, pty_utmp_helper_pipe;
 static int pty_term_width, pty_term_height;
 static sig_atomic_t pty_child_dead;
+static int pty_exit_code;
 #ifndef OMIT_UTMP
 static struct utmp utmp_entry;
 #endif
 char **pty_argv;
 
-int pty_child_is_dead(void)
-{
-    return pty_child_dead;
-}
-
 static void setup_utmp(char *ttyname, char *location)
 {
 #ifndef OMIT_UTMP
@@ -156,8 +165,10 @@ static void sigchld_handler(int signum)
     pid_t pid;
     int status;
     pid = waitpid(-1, &status, WNOHANG);
-    if (pid == pty_child_pid && (WIFEXITED(status) || WIFSIGNALED(status)))
-	pty_child_dead = TRUE;	
+    if (pid == pty_child_pid && (WIFEXITED(status) || WIFSIGNALED(status))) {
+	pty_exit_code = status;
+	pty_child_dead = TRUE;
+    }
 }
 
 static void fatal_sig_handler(int signum)
@@ -371,12 +382,14 @@ void pty_pre_init(void)
  * Also places the canonical host name into `realhost'. It must be
  * freed by the caller.
  */
-static char *pty_init(void *frontend,
+static char *pty_init(void *frontend, void **backend_handle,
 		      char *host, int port, char **realhost, int nodelay)
 {
     int slavefd;
     pid_t pid, pgrp;
 
+    *backend_handle = NULL;	       /* we can't sensibly use this, sadly */
+
     pty_term_width = cfg.width;
     pty_term_height = cfg.height;
 
@@ -495,8 +508,11 @@ static char *pty_init(void *frontend,
 /*
  * Called to send data down the pty.
  */
-static int pty_send(char *buf, int len)
+static int pty_send(void *handle, char *buf, int len)
 {
+    if (pty_master_fd < 0)
+	return 0;		       /* ignore all writes if fd closed */
+
     while (len > 0) {
 	int ret = write(pty_master_fd, buf, len);
 	if (ret < 0) {
@@ -509,10 +525,19 @@ static int pty_send(char *buf, int len)
     return 0;
 }
 
+void pty_close(void)
+{
+    if (pty_master_fd >= 0) {
+	close(pty_master_fd);
+	pty_master_fd = -1;
+    }
+    close(pty_utmp_helper_pipe);       /* this causes utmp to be cleaned up */
+}
+
 /*
  * Called to query the current socket sendability status.
  */
-static int pty_sendbuffer(void)
+static int pty_sendbuffer(void *handle)
 {
     return 0;
 }
@@ -520,7 +545,7 @@ static int pty_sendbuffer(void)
 /*
  * Called to set the size of the window
  */
-static void pty_size(int width, int height)
+static void pty_size(void *handle, int width, int height)
 {
     struct winsize size;
 
@@ -538,36 +563,43 @@ static void pty_size(int width, int height)
 /*
  * Send special codes.
  */
-static void pty_special(Telnet_Special code)
+static void pty_special(void *handle, Telnet_Special code)
 {
     /* Do nothing! */
     return;
 }
 
-static Socket pty_socket(void)
+static Socket pty_socket(void *handle)
 {
     return NULL;		       /* shouldn't ever be needed */
 }
 
-static int pty_sendok(void)
+static int pty_sendok(void *handle)
 {
     return 1;
 }
 
-static void pty_unthrottle(int backlog)
+static void pty_unthrottle(void *handle, int backlog)
 {
     /* do nothing */
 }
 
-static int pty_ldisc(int option)
+static int pty_ldisc(void *handle, int option)
 {
     return 0;			       /* neither editing nor echoing */
 }
 
-static int pty_exitcode(void)
+static void pty_provide_ldisc(void *handle, void *ldisc)
 {
-    /* Shouldn't ever be required */
-    return 0;
+    /* This is a stub. */
+}
+
+static int pty_exitcode(void *handle)
+{
+    if (!pty_child_dead)
+	return -1;		       /* not dead yet */
+    else
+	return pty_exit_code;
 }
 
 Backend pty_backend = {
@@ -580,6 +612,7 @@ Backend pty_backend = {
     pty_exitcode,
     pty_sendok,
     pty_ldisc,
+    pty_provide_ldisc,
     pty_unthrottle,
     1
 };