Add additional port locking for root users

Fazecast · Mar 7, 2019 · 051ba9f · 051ba9f
1 parent 11896f4
commit 051ba9f
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Showing 2 changed files with 40 additions and 4 deletions.
diff --git a/src/main/c/Posix/PosixHelperFunctions.c b/src/main/c/Posix/PosixHelperFunctions.c
@@ -2,10 +2,10 @@
  * PosixHelperFunctions.c
  *
  *       Created on:  Mar 10, 2015
- *  Last Updated on:  Dec 07, 2018
+ *  Last Updated on:  Mar 07, 2019
  *           Author:  Will Hedgecock
  *
- * Copyright (C) 2012-2018 Fazecast, Inc.
+ * Copyright (C) 2012-2019 Fazecast, Inc.
  *
  * This file is part of jSerialComm.
  *
@@ -24,6 +24,7 @@
  */
 
 #include <dirent.h>
+#include <errno.h>
 #include <fcntl.h>
 #include <stdlib.h>
 #include <stdio.h>
@@ -613,6 +614,36 @@ void searchForComPorts(charTupleVector* comPorts)
 	}
 }
 
+int flock(int fd, int op)
+{
+	int rc = 0;
+
+#if defined(F_SETLK) && defined(F_SETLKW)
+	struct flock fl = {0};
+	switch (op & (LOCK_EX|LOCK_SH|LOCK_UN))
+	{
+		case LOCK_EX:
+			fl.l_type = F_WRLCK;
+			break;
+		case LOCK_SH:
+			fl.l_type = F_RDLCK;
+			break;
+		case LOCK_UN:
+			fl.l_type = F_UNLCK;
+			break;
+		default:
+			errno = EINVAL;
+			return -1;
+	}
+	fl.l_whence = SEEK_SET;
+	rc = fcntl(fd, op & LOCK_NB ? F_SETLK : F_SETLKW, &fl);
+	if (rc && (errno == EAGAIN))
+		errno = EWOULDBLOCK;
+#endif
+
+	return rc;
+}
+
 baud_rate getBaudRateCode(baud_rate baudRate)
 {
 	// Translate a raw baud rate into a system-specified one

diff --git a/src/main/c/Posix/PosixHelperFunctions.h b/src/main/c/Posix/PosixHelperFunctions.h
@@ -2,10 +2,10 @@
  * PosixHelperFunctions.h
  *
  *       Created on:  Mar 10, 2015
- *  Last Updated on:  Nov 12, 2018
+ *  Last Updated on:  Mar 07, 2019
  *           Author:  Will Hedgecock
  *
- * Copyright (C) 2012-2018 Fazecast, Inc.
+ * Copyright (C) 2012-2019 Fazecast, Inc.
  *
  * This file is part of jSerialComm.
  *
@@ -53,8 +53,13 @@ void driverBasedSearchForComPorts(charTupleVector* comPorts);
 
 // Solaris-specific functionality
 #elif defined(__sun__)
+#define LOCK_SH 1
+#define LOCK_EX 2
+#define LOCK_NB 4
+#define LOCK_UN 8
 typedef int baud_rate;
 extern int ioctl(int __fd, int __request, ...);
+int flock(int fd, int op);
 void searchForComPorts(charTupleVector* comPorts);
 
 // Apple-specific functionality