Ticket #59124: patch-legacysupport-fsgetpath.diff

README.md

@@ -93 +93 @@
     <td>Adds <code>openat</code> function</td>
     <td>OSX10.9</td>
   </tr>
+  <tr>
+    <td><code>sys/fsgetpath.h</code></td>
+    <td>Adds missing <code>fsgetpath</code> function</td>
+    <td>OSX10.12</td>
+  </tr>
   <tr>
     <td><code>sys/mman.h</code></td>
     <td>Adds missing <code>MAP_ANONYMOUS</code> definition</td>

include/MacportsLegacySupport.h

@@ -34 +34 @@
 
 /* defines for when legacy support is required for various functions */
 
+/* fsgetpath */
+#define __MP_LEGACY_SUPPORT_FSGETPATH__       (__APPLE__ && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 101300)
+
 /* clock_gettime */
 #define __MP_LEGACY_SUPPORT_GETTIME__         (__APPLE__ && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 101200)
 

new file include/sys/fsgetpath.h

@@ +1 @@
+/*
+ * Copyright (c) 2019 Ken Cunningham <kencu@macports.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef _MACPORTS_FSGETPATH_H_
+#define _MACPORTS_FSGETPATH_H_
+
+/* MP support header */
+#include "MacportsLegacySupport.h"
+
+#if defined(__has_include_next)
+#if __has_include_next(<sys/fsgetpath.h>)
+
+/* Include the primary system sys/fsgetpath.h */
+#include_next <sys/fsgetpath.h>
+
+#endif
+#endif
+
+#if __MP_LEGACY_SUPPORT_FSGETPATH__
+
+#if __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ >= 1060
+
+__MP__BEGIN_DECLS
+extern ssize_t fsgetpath(char * __restrict buf, size_t bufsize, fsid_t* fsid, uint64_t objid);
+__MP__END_DECLS
+
+#else
+#error "No implementation of fsgetpath is presently available for MacOSX prior to 10.6"
+#endif /* __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ >= 1060 */
+
+#endif /* __MP_LEGACY_SUPPORT_FSGETPATH__ */
+
+#endif /* _MACPORTS_FSGETPATH_H_ */

new file src/fsgetpath.c

@@ +1 @@
+/*
+ * Copyright (c) 2019 Ken Cunningham <kencu@macports.org>
+ * from an example posted in Apple Developer Support
+ * https://forums.developer.apple.com/thread/103162
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+
+// MP support header
+#include "MacportsLegacySupport.h"
+#if __MP_LEGACY_SUPPORT_FSGETPATH__
+
+
+#if 1
+/* implement using a syscall available macOS 10.6 to 10.12 */
+/* this should be thoroughly vetted as a syscall, but is private API */
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <sys/mount.h>
+ssize_t fsgetpath(char * buf, size_t buflen, fsid_t * fsid, uint64_t obj_id) {
+    return (ssize_t)syscall(SYS_fsgetpath, buf, (size_t)buflen, fsid, (uint64_t)obj_id);
+}
+#endif
+
+
+#if 0
+/* implement with a compatability function that presently compiles on 10.6 and over */
+/* this may be better (see linked post above) but it's hard to thoroughly test it. */
+/* this may also be able to be expanded to cover 10.4 and 10.5 if we can workaround ATTR_CMN_FULLPATH */
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <getopt.h>
+#include <sys/attr.h>
+#include <sys/mount.h>
+
+ssize_t fsgetpath(char * buf, size_t buflen, fsid_t * fsid, uint64_t obj_id) {
+    char volfsPath[64];  // 8 for `/.vol//\0`, 10 for `fsid->val[0]`, 20 for `obj_id`, rounded up for paranoia
+
+    snprintf(volfsPath, sizeof(volfsPath), "/.vol/%ld/%llu", (long) fsid->val[0], (unsigned long long) obj_id);
+
+    struct {
+        uint32_t            length;
+        attrreference_t     pathRef;
+        char                buffer[MAXPATHLEN];
+    } __attribute__((aligned(4), packed)) attrBuf;
+
+    struct attrlist attrList;
+    memset(&attrList, 0, sizeof(attrList));
+    attrList.bitmapcount = ATTR_BIT_MAP_COUNT;
+    attrList.commonattr = ATTR_CMN_FULLPATH;
+
+    int success = getattrlist(volfsPath, &attrList, &attrBuf, sizeof(attrBuf), 0) == 0;
+    if ( ! success ) {
+        return -1;
+    }
+    if (attrBuf.pathRef.attr_length > buflen) {
+        errno = ENOSPC;
+        return -1;
+    }
+    strlcpy(buf, ((const char *) &attrBuf.pathRef) + attrBuf.pathRef.attr_dataoffset, buflen);
+    return attrBuf.pathRef.attr_length;
+}
+#endif
+
+#endif /* __MP_LEGACY_SUPPORT_FSGETPATH__ */