From 06bd023d07eaa8b5ff848f3d3d4a3126fda7fb73 Mon Sep 17 00:00:00 2001
From: Costin Lupu <costin.lupu@cs.pub.ro>
Date: Mon, 25 Nov 2019 09:47:43 +0200
Subject: [PATCH] sockets.c: Add ppoll() function

This ppoll() implementation is adapted from its man page. If tmo_p is NULL,
then ppoll() can block indefinitely.

Signed-off-by: Costin Lupu <costin.lupu@cs.pub.ro>
Reviewed-by: Stefan Teodorescu <stefanl.teodorescu@gmail.com>
---
 Config.uk |  6 ++++++
 sockets.c | 36 ++++++++++++++++++++++++++++++++++++
 2 files changed, 42 insertions(+)

diff --git a/Config.uk b/Config.uk
index 8f501fc..debf0c7 100644
--- a/Config.uk
+++ b/Config.uk
@@ -170,6 +170,12 @@ if LWIP_SOCKET
 			lwip's select() implementation supports only sockets. This
 			configuration option makes it possible to use other file descriptor
 			types as well, even though they are not supported by lwip.
+
+	config LWIP_SOCKET_PPOLL
+		bool "Enable ppoll()"
+		default y
+		help
+			Enable ppoll() implementation.
 endif
 
 menuconfig LWIP_DEBUG
diff --git a/sockets.c b/sockets.c
index c2cf57f..8fde21a 100644
--- a/sockets.c
+++ b/sockets.c
@@ -34,7 +34,11 @@
  */
 
 /* network stub calls */
+#include <uk/config.h>
 #include <sys/time.h>
+#if CONFIG_LWIP_SOCKET_PPOLL
+#include <signal.h>
+#endif
 #include <vfscore/dentry.h>
 #include <vfscore/file.h>
 #include <vfscore/fs.h>
@@ -473,6 +477,38 @@ EXIT:
 	return ret;
 }
 
+#if CONFIG_LWIP_SOCKET_PPOLL
+#if CONFIG_LIBPTHREAD_EMBEDDED
+#define __sigmask   pthread_sigmask
+#else
+#define __sigmask   sigprocmask
+#endif
+int ppoll(struct pollfd *fds, nfds_t nfds, const struct timespec *tmo_p,
+		const sigset_t *sigmask)
+{
+	sigset_t origmask;
+	int timeout, rc, _rc;
+
+	if (!fds) {
+		errno = EFAULT;
+		rc = -1;
+		goto out;
+	}
+
+	timeout = (tmo_p == NULL) ? -1 :
+		(tmo_p->tv_sec * 1000 + tmo_p->tv_nsec / 1000000);
+	rc = __sigmask(SIG_SETMASK, sigmask, &origmask);
+	if (rc)
+		goto out;
+	rc = poll(fds, nfds, timeout);
+	_rc = __sigmask(SIG_SETMASK, &origmask, NULL);
+	if (rc == 0 && _rc != 0)
+		rc = _rc;
+out:
+	return rc;
+}
+#endif /* CONFIG_LWIP_SOCKET_PPOLL */
+
 int select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
 		struct timeval *timeout)
 {
-- 
2.39.5