compat/fsmonitor/fsm-path-utils-win32.c

   1 #include "git-compat-util.h"
   2 #include "fsmonitor-ll.h"
   3 #include "fsmonitor-path-utils.h"
   4 #include "gettext.h"
   5 #include "trace.h"
   6
   7 /*
   8  * Check remote working directory protocol.
   9  *
  10  * Return -1 if client machine cannot get remote protocol information.
  11  */
  12 static int check_remote_protocol(wchar_t *wpath)
  13 {
  14         HANDLE h;
  15         FILE_REMOTE_PROTOCOL_INFO proto_info;
  16
  17         h = CreateFileW(wpath, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING,
  18                         FILE_FLAG_BACKUP_SEMANTICS, NULL);
  19
  20         if (h == INVALID_HANDLE_VALUE) {
  21                 error(_("[GLE %ld] unable to open for read '%ls'"),
  22                       GetLastError(), wpath);
  23                 return -1;
  24         }
  25
  26         if (!GetFileInformationByHandleEx(h, FileRemoteProtocolInfo,
  27                 &proto_info, sizeof(proto_info))) {
  28                 error(_("[GLE %ld] unable to get protocol information for '%ls'"),
  29                       GetLastError(), wpath);
  30                 CloseHandle(h);
  31                 return -1;
  32         }
  33
  34         CloseHandle(h);
  35
  36         trace_printf_key(&trace_fsmonitor,
  37                                 "check_remote_protocol('%ls') remote protocol %#8.8lx",
  38                                 wpath, proto_info.Protocol);
  39
  40         return 0;
  41 }
  42
  43 /*
  44  * Notes for testing:
  45  *
  46  * (a) Windows allows a network share to be mapped to a drive letter.
  47  *     (This is the normal method to access it.)
  48  *
  49  *     $ NET USE Z: \\server\share
  50  *     $ git -C Z:/repo status
  51  *
  52  * (b) Windows allows a network share to be referenced WITHOUT mapping
  53  *     it to drive letter.
  54  *
  55  *     $ NET USE \\server\share\dir
  56  *     $ git -C //server/share/repo status
  57  *
  58  * (c) Windows allows "SUBST" to create a fake drive mapping to an
  59  *     arbitrary path (which may be remote)
  60  *
  61  *     $ SUBST Q: Z:\repo
  62  *     $ git -C Q:/ status
  63  *
  64  * (d) Windows allows a directory symlink to be created on a local
  65  *     file system that points to a remote repo.
  66  *
  67  *     $ mklink /d ./link //server/share/repo
  68  *     $ git -C ./link status
  69  */
  70 int fsmonitor__get_fs_info(const char *path, struct fs_info *fs_info)
  71 {
  72         wchar_t wpath[MAX_PATH];
  73         wchar_t wfullpath[MAX_PATH];
  74         size_t wlen;
  75         UINT driveType;
  76
  77         /*
  78          * Do everything in wide chars because the drive letter might be
  79          * a multi-byte sequence.  See win32_has_dos_drive_prefix().
  80          */
  81         if (xutftowcs_path(wpath, path) < 0) {
  82                 return -1;
  83         }
  84
  85         /*
  86          * GetDriveTypeW() requires a final slash.  We assume that the
  87          * worktree pathname points to an actual directory.
  88          */
  89         wlen = wcslen(wpath);
  90         if (wpath[wlen - 1] != L'\\' && wpath[wlen - 1] != L'/') {
  91                 wpath[wlen++] = L'\\';
  92                 wpath[wlen] = 0;
  93         }
  94
  95         /*
  96          * Normalize the path.  If nothing else, this converts forward
  97          * slashes to backslashes.  This is essential to get GetDriveTypeW()
  98          * correctly handle some UNC "\\server\share\..." paths.
  99          */
 100         if (!GetFullPathNameW(wpath, MAX_PATH, wfullpath, NULL)) {
 101                 return -1;
 102         }
 103
 104         driveType = GetDriveTypeW(wfullpath);
 105         trace_printf_key(&trace_fsmonitor,
 106                          "DriveType '%s' L'%ls' (%u)",
 107                          path, wfullpath, driveType);
 108
 109         if (driveType == DRIVE_REMOTE) {
 110                 fs_info->is_remote = 1;
 111                 if (check_remote_protocol(wfullpath) < 0)
 112                         return -1;
 113         } else {
 114                 fs_info->is_remote = 0;
 115         }
 116
 117         trace_printf_key(&trace_fsmonitor,
 118                                 "'%s' is_remote: %d",
 119                                 path, fs_info->is_remote);
 120
 121         return 0;
 122 }
 123
 124 int fsmonitor__is_fs_remote(const char *path)
 125 {
 126         struct fs_info fs;
 127         if (fsmonitor__get_fs_info(path, &fs))
 128                 return -1;
 129         return fs.is_remote;
 130 }
 131
 132 /*
 133  * No-op for now.
 134  */
 135 int fsmonitor__get_alias(const char *path UNUSED,
 136                          struct alias_info *info UNUSED)
 137 {
 138         return 0;
 139 }
 140
 141 /*
 142  * No-op for now.
 143  */
 144 char *fsmonitor__resolve_alias(const char *path UNUSED,
 145                                const struct alias_info *info UNUSED)
 146 {
 147         return NULL;
 148 }