1 files changed, 247 insertions, 0 deletions
diff --git a/src/VBox/Runtime/r3/posix/symlink-posix.cpp b/src/VBox/Runtime/r3/posix/symlink-posix.cpp
new file mode 100644
index 00000000..e43f5b36
--- /dev/null
+++ b/src/VBox/Runtime/r3/posix/symlink-posix.cpp
@@ -0,0 +1,247 @@
+/* $Id: symlink-posix.cpp $ */
+/** @file
+ * IPRT - Symbolic Links, POSIX.
+ */
+
+/*
+ * Copyright (C) 2010-2023 Oracle and/or its affiliates.
+ *
+ * This file is part of VirtualBox base platform packages, as
+ * available from https://www.virtualbox.org.
+ *
+ * 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 the Free Software Foundation, in version 3 of the
+ * License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <https://www.gnu.org/licenses>.
+ *
+ * The contents of this file may alternatively be used under the terms
+ * of the Common Development and Distribution License Version 1.0
+ * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
+ * in the VirtualBox distribution, in which case the provisions of the
+ * CDDL are applicable instead of those of the GPL.
+ *
+ * You may elect to license modified versions of this file under the
+ * terms and conditions of either the GPL or the CDDL or both.
+ *
+ * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
+ */
+
+
+/*********************************************************************************************************************************
+*   Header Files                                                                                                                 *
+*********************************************************************************************************************************/
+#define LOG_GROUP RTLOGGROUP_SYMLINK
+
+#include <errno.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include <iprt/symlink.h>
+
+#include <iprt/assert.h>
+#include <iprt/err.h>
+#include <iprt/log.h>
+#include <iprt/mem.h>
+#include <iprt/string.h>
+#include "internal/path.h"
+
+
+
+RTDECL(bool) RTSymlinkExists(const char *pszSymlink)
+{
+    bool fRc = false;
+    char const *pszNativeSymlink;
+    int rc = rtPathToNative(&pszNativeSymlink, pszSymlink, NULL);
+    if (RT_SUCCESS(rc))
+    {
+        struct stat s;
+        fRc = !lstat(pszNativeSymlink, &s)
+            && S_ISLNK(s.st_mode);
+
+        rtPathFreeNative(pszNativeSymlink, pszSymlink);
+    }
+
+    LogFlow(("RTSymlinkExists(%p={%s}): returns %RTbool\n", pszSymlink, pszSymlink, fRc));
+    return fRc;
+}
+
+
+RTDECL(bool) RTSymlinkIsDangling(const char *pszSymlink)
+{
+    bool fRc = false;
+    char const *pszNativeSymlink;
+    int rc = rtPathToNative(&pszNativeSymlink, pszSymlink, NULL);
+    if (RT_SUCCESS(rc))
+    {
+        struct stat s;
+        fRc = !lstat(pszNativeSymlink, &s)
+            && S_ISLNK(s.st_mode);
+        if (fRc)
+        {
+            errno = 0;
+            fRc = stat(pszNativeSymlink, &s) != 0
+               && (   errno == ENOENT
+                   || errno == ENOTDIR
+                   || errno == ELOOP);
+        }
+
+        rtPathFreeNative(pszNativeSymlink, pszSymlink);
+    }
+
+    LogFlow(("RTSymlinkIsDangling(%p={%s}): returns %RTbool\n", pszSymlink, pszSymlink, fRc));
+    return fRc;
+}
+
+
+RTDECL(int) RTSymlinkCreate(const char *pszSymlink, const char *pszTarget, RTSYMLINKTYPE enmType, uint32_t fCreate)
+{
+    RT_NOREF_PV(fCreate);
+
+    /*
+     * Validate the input.
+     */
+    AssertReturn(enmType > RTSYMLINKTYPE_INVALID && enmType < RTSYMLINKTYPE_END, VERR_INVALID_PARAMETER);
+    AssertPtrReturn(pszSymlink, VERR_INVALID_POINTER);
+    AssertPtrReturn(pszTarget, VERR_INVALID_POINTER);
+
+    /*
+     * Convert the paths.
+     */
+    char const *pszNativeSymlink;
+    int rc = rtPathToNative(&pszNativeSymlink, pszSymlink, NULL);
+    if (RT_SUCCESS(rc))
+    {
+        const char *pszNativeTarget;
+        rc = rtPathToNative(&pszNativeTarget, pszTarget, NULL);
+        if (RT_SUCCESS(rc))
+        {
+            /*
+             * Create the link.
+             */
+            if (symlink(pszNativeTarget, pszNativeSymlink) == 0)
+                rc = VINF_SUCCESS;
+            else
+                rc = RTErrConvertFromErrno(errno);
+
+            rtPathFreeNative(pszNativeTarget, pszTarget);
+        }
+        rtPathFreeNative(pszNativeSymlink, pszSymlink);
+    }
+
+    LogFlow(("RTSymlinkCreate(%p={%s}, %p={%s}, %d, %#x): returns %Rrc\n", pszSymlink, pszSymlink, pszTarget, pszTarget, enmType, fCreate, rc));
+    return rc;
+}
+
+
+RTDECL(int) RTSymlinkDelete(const char *pszSymlink, uint32_t fDelete)
+{
+    RT_NOREF_PV(fDelete);
+
+    char const *pszNativeSymlink;
+    int rc = rtPathToNative(&pszNativeSymlink, pszSymlink, NULL);
+    if (RT_SUCCESS(rc))
+    {
+        struct stat s;
+        if (!lstat(pszNativeSymlink, &s))
+        {
+            if (S_ISLNK(s.st_mode))
+            {
+                if (unlink(pszNativeSymlink) == 0)
+                    rc = VINF_SUCCESS;
+                else
+                    rc = RTErrConvertFromErrno(errno);
+            }
+            else
+                rc = VERR_NOT_SYMLINK;
+        }
+        else
+            rc = RTErrConvertFromErrno(errno);
+        rtPathFreeNative(pszNativeSymlink, pszSymlink);
+    }
+
+    LogFlow(("RTSymlinkDelete(%p={%s}, #%x): returns %Rrc\n", pszSymlink, pszSymlink, fDelete, rc));
+    return rc;
+}
+
+
+RTDECL(int) RTSymlinkRead(const char *pszSymlink, char *pszTarget, size_t cbTarget, uint32_t fRead)
+{
+    RT_NOREF_PV(fRead);
+
+    char *pszMyTarget;
+    int rc = RTSymlinkReadA(pszSymlink, &pszMyTarget);
+    if (RT_SUCCESS(rc))
+    {
+        rc = RTStrCopy(pszTarget, cbTarget, pszMyTarget);
+        RTStrFree(pszMyTarget);
+    }
+    LogFlow(("RTSymlinkRead(%p={%s}): returns %Rrc\n", pszSymlink, pszSymlink, rc));
+    return rc;
+}
+
+
+RTDECL(int) RTSymlinkReadA(const char *pszSymlink, char **ppszTarget)
+{
+    AssertPtr(ppszTarget);
+    char const *pszNativeSymlink;
+    int rc = rtPathToNative(&pszNativeSymlink, pszSymlink, NULL);
+    if (RT_SUCCESS(rc))
+    {
+        /* Guess the initial buffer size. */
+        ssize_t     cbBuf;
+        struct stat s;
+        if (!lstat(pszNativeSymlink, &s))
+            cbBuf = RT_MAX(RT_ALIGN_Z(s.st_size, 64), 64);
+        else
+            cbBuf = 1024;
+
+        /* Read loop that grows the buffer. */
+        char *pszBuf = NULL;
+        for (;;)
+        {
+            RTMemTmpFree(pszBuf);
+            pszBuf = (char *)RTMemTmpAlloc(cbBuf);
+            if (pszBuf)
+            {
+                ssize_t cbReturned = readlink(pszNativeSymlink, pszBuf, cbBuf);
+                if (cbReturned >= cbBuf)
+                {
+                    /* Increase the buffer size and try again */
+                    cbBuf *= 2;
+                    continue;
+                }
+
+                if (cbReturned > 0)
+                {
+                    pszBuf[cbReturned] = '\0';
+                    rc = rtPathFromNativeDup(ppszTarget, pszBuf, pszSymlink);
+                }
+                else if (errno == EINVAL)
+                    rc = VERR_NOT_SYMLINK;
+                else
+                    rc = RTErrConvertFromErrno(errno);
+            }
+            else
+                rc = VERR_NO_TMP_MEMORY;
+            break;
+        } /* for loop */
+
+        RTMemTmpFree(pszBuf);
+        rtPathFreeNative(pszNativeSymlink, pszSymlink);
+    }
+
+    if (RT_SUCCESS(rc))
+        LogFlow(("RTSymlinkReadA(%p={%s},%p): returns %Rrc *ppszTarget=%p:{%s}\n", pszSymlink, pszSymlink, ppszTarget, rc, *ppszTarget, *ppszTarget));
+    else
+        LogFlow(("RTSymlinkReadA(%p={%s},%p): returns %Rrc\n", pszSymlink, pszSymlink, ppszTarget, rc));
+    return rc;
+}
+