From b48159dce258fda4a5e570ff3485be0079e6e25f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Duval?= <jerome.duval@gmail.com>
Date: Sat, 31 Oct 2020 17:05:39 +0100
Subject: [PATCH] POSIX: add tcgetsid()
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Change-Id: If58141b4e56b7fe444460b6808e33abc5ea71f37
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3374
Reviewed-by: Axel Dörfler <axeld@pinc-software.de>
---
 headers/posix/termios.h                |  2 ++
 src/add-ons/kernel/drivers/tty/tty.cpp |  9 +++++++++
 src/system/libroot/posix/termios.c     | 13 +++++++++++++
 3 files changed, 24 insertions(+)

diff --git a/headers/posix/termios.h b/headers/posix/termios.h
index 141746eb23..e8ec24428a 100644
--- a/headers/posix/termios.h
+++ b/headers/posix/termios.h
@@ -187,6 +187,7 @@ struct termios {
 #define TIOCCBRK			(TCGETA + 21)	/* both are a frontend to TCSBRK */
 #define TIOCMBIS			(TCGETA + 22)	/* set bits in line state */
 #define TIOCMBIC			(TCGETA + 23)	/* clear bits in line state */
+#define	TIOCGSID			(TCGETA + 24)	/* get session leader process group ID */
 
 /* Event codes.  Returned from TCWAITEVENT */
 #define EV_RING			0x0001
@@ -233,6 +234,7 @@ extern int		tcsendbreak(int fd, int duration);
 extern int		tcdrain(int fd);
 extern int		tcflow(int fd, int action);
 extern int		tcflush(int fd, int queueSelector);
+extern pid_t	tcgetsid(int fd);
 
 #ifdef __cplusplus
 }
diff --git a/src/add-ons/kernel/drivers/tty/tty.cpp b/src/add-ons/kernel/drivers/tty/tty.cpp
index 95e53ed478..0117696b44 100644
--- a/src/add-ons/kernel/drivers/tty/tty.cpp
+++ b/src/add-ons/kernel/drivers/tty/tty.cpp
@@ -1679,6 +1679,15 @@ tty_ioctl(tty_cookie* cookie, uint32 op, void* buffer, size_t length)
 			return B_OK;
 		}
 
+		// get session leader process group ID
+
+		case TIOCGSID:
+		{
+			TRACE(("tty: get session_id\n"));
+			return user_memcpy(buffer, &tty->settings->session_id,
+				sizeof(pid_t));
+		}
+
 		// get and set window size
 
 		case TIOCGWINSZ:
diff --git a/src/system/libroot/posix/termios.c b/src/system/libroot/posix/termios.c
index f60602eb7e..18b9c96c2f 100644
--- a/src/system/libroot/posix/termios.c
+++ b/src/system/libroot/posix/termios.c
@@ -167,3 +167,16 @@ cfmakeraw(struct termios *termios)
 	termios->c_cflag &= ~(CSIZE | PARENB);
 	termios->c_cflag |= CS8;
 }
+
+
+pid_t
+tcgetsid(int fd)
+{
+	int sid;
+
+	if (ioctl(fd, TIOCGSID, &sid) == 0)
+		return sid;
+
+	return -1;
+}
+