7 files changed, 92 insertions, 9 deletions

diff --git a/Config.in b/Config.in
index 2b4b81515..100f6e491 100644
--- a/Config.in
+++ b/Config.in
@@ -473,6 +473,16 @@ config FEATURE_IDENTIFY_OWNER
         Try to determine if files belong to the current user.  If they don't
         they're listed as belonging to root.
 
+config FEATURE_READLINK2
+        bool "Read the contents of symbolic links (1.1 kb)"
+        default y
+        depends on PLATFORM_MINGW32
+        help
+        Implement the readlink(2) system call to allow applets to read
+        the contents of symbolic links.  With this feature ls and stat
+        can display the target of symbolic links and it makes sense to
+        enable the readlink applet.
+
 comment 'Build Options'
 
 config STATIC
diff --git a/configs/mingw32_defconfig b/configs/mingw32_defconfig
index c30ffa1b5..a29cc164a 100644
--- a/configs/mingw32_defconfig
+++ b/configs/mingw32_defconfig
@@ -1,7 +1,7 @@
 #
 # Automatically generated make config: don't edit
 # Busybox version: 1.31.0.git
-# Fri Mar  1 08:50:17 2019
+# Wed Mar  6 09:32:59 2019
 #
 CONFIG_HAVE_DOT_CONFIG=y
 # CONFIG_PLATFORM_POSIX is not set
@@ -50,6 +50,7 @@ CONFIG_FEATURE_ICON_ALL=y
 CONFIG_FEATURE_EURO=y
 CONFIG_FEATURE_EXTRA_FILE_DATA=y
 CONFIG_FEATURE_IDENTIFY_OWNER=y
+CONFIG_FEATURE_READLINK2=y
 
 #
 # Build Options
@@ -295,8 +296,8 @@ CONFIG_PASTE=y
 CONFIG_PRINTENV=y
 CONFIG_PRINTF=y
 CONFIG_PWD=y
-# CONFIG_READLINK is not set
-# CONFIG_FEATURE_READLINK_FOLLOW is not set
+CONFIG_READLINK=y
+CONFIG_FEATURE_READLINK_FOLLOW=y
 CONFIG_REALPATH=y
 CONFIG_RM=y
 CONFIG_RMDIR=y
@@ -1113,6 +1114,7 @@ CONFIG_ASH_HELP=y
 CONFIG_ASH_GETOPTS=y
 CONFIG_ASH_CMDCMD=y
 CONFIG_ASH_NOCONSOLE=y
+CONFIG_ASH_NOCASEGLOB=y
 # CONFIG_CTTYHACK is not set
 # CONFIG_HUSH is not set
 # CONFIG_HUSH_BASH_COMPAT is not set
diff --git a/configs/mingw64_defconfig b/configs/mingw64_defconfig
index 46cb6941f..3d6102f0a 100644
--- a/configs/mingw64_defconfig
+++ b/configs/mingw64_defconfig
@@ -1,7 +1,7 @@
 #
 # Automatically generated make config: don't edit
 # Busybox version: 1.31.0.git
-# Fri Mar  1 08:50:17 2019
+# Wed Mar  6 09:32:59 2019
 #
 CONFIG_HAVE_DOT_CONFIG=y
 # CONFIG_PLATFORM_POSIX is not set
@@ -50,6 +50,7 @@ CONFIG_FEATURE_ICON_ALL=y
 CONFIG_FEATURE_EURO=y
 CONFIG_FEATURE_EXTRA_FILE_DATA=y
 CONFIG_FEATURE_IDENTIFY_OWNER=y
+CONFIG_FEATURE_READLINK2=y
 
 #
 # Build Options
@@ -295,8 +296,8 @@ CONFIG_PASTE=y
 CONFIG_PRINTENV=y
 CONFIG_PRINTF=y
 CONFIG_PWD=y
-# CONFIG_READLINK is not set
-# CONFIG_FEATURE_READLINK_FOLLOW is not set
+CONFIG_READLINK=y
+CONFIG_FEATURE_READLINK_FOLLOW=y
 CONFIG_REALPATH=y
 CONFIG_RM=y
 CONFIG_RMDIR=y
@@ -1113,6 +1114,7 @@ CONFIG_ASH_HELP=y
 CONFIG_ASH_GETOPTS=y
 CONFIG_ASH_CMDCMD=y
 CONFIG_ASH_NOCONSOLE=y
+CONFIG_ASH_NOCASEGLOB=y
 # CONFIG_CTTYHACK is not set
 # CONFIG_HUSH is not set
 # CONFIG_HUSH_BASH_COMPAT is not set
diff --git a/coreutils/ls.c b/coreutils/ls.c
index c5402de30..6be3eb291 100644
--- a/coreutils/ls.c
+++ b/coreutils/ls.c
@@ -492,7 +492,7 @@ static NOINLINE unsigned display_single(const struct dnode *dn)
         /* Do readlink early, so that if it fails, error message
          * does not appear *inside* the "ls -l" line */
         lpath = NULL;
-#if !ENABLE_PLATFORM_MINGW32
+#if ENABLE_PLATFORM_POSIX || ENABLE_FEATURE_READLINK2
         if (opt & OPT_l)
                 if (S_ISLNK(dn->dn_mode))
                         lpath = xmalloc_readlink_or_warn(dn->fullname);
diff --git a/coreutils/stat.c b/coreutils/stat.c
index 32bc5e2d3..cf13af0b6 100644
--- a/coreutils/stat.c
+++ b/coreutils/stat.c
@@ -317,7 +317,7 @@ static void FAST_FUNC print_stat(char *pformat, const char m,
                 printfs(pformat, filename);
         } else if (m == 'N') {
                 strcatc(pformat, 's');
-#if !ENABLE_PLATFORM_MINGW32
+#if ENABLE_PLATFORM_POSIX || ENABLE_FEATURE_READLINK2
                 if (S_ISLNK(statbuf->st_mode)) {
                         char *linkname = xmalloc_readlink_or_warn(filename);
                         if (linkname == NULL)
@@ -712,7 +712,7 @@ static bool do_stat(const char *filename, const char *format)
                 gw_ent = getgrgid(statbuf.st_gid);
                 pw_ent = getpwuid(statbuf.st_uid);
 
-#if !ENABLE_PLATFORM_MINGW32
+#if ENABLE_PLATFORM_POSIX || ENABLE_FEATURE_READLINK2
                 if (S_ISLNK(statbuf.st_mode))
                         linkname = xmalloc_readlink_or_warn(filename);
                 if (linkname) {
diff --git a/include/mingw.h b/include/mingw.h
index 188d4eecf..b5324e49b 100644
--- a/include/mingw.h
+++ b/include/mingw.h
@@ -407,7 +407,11 @@ int mingw_xopen(const char *filename, int oflags);
 ssize_t mingw_read(int fd, void *buf, size_t count);
 int mingw_close(int fd);
 int pipe(int filedes[2]);
+#if ENABLE_FEATURE_READLINK2
+ssize_t readlink(const char *pathname, char *buf, size_t bufsiz);
+#else
 NOIMPL(readlink,const char *path UNUSED_PARAM, char *buf UNUSED_PARAM, size_t bufsiz UNUSED_PARAM);
+#endif
 NOIMPL(setgid,gid_t gid UNUSED_PARAM);
 NOIMPL(setegid,gid_t gid UNUSED_PARAM);
 NOIMPL(setsid,void);
diff --git a/win32/mingw.c b/win32/mingw.c
index dda2e9a60..c42dbed97 100644
--- a/win32/mingw.c
+++ b/win32/mingw.c
@@ -4,6 +4,9 @@
 #if ENABLE_FEATURE_IDENTIFY_OWNER
 #include <aclapi.h>
 #endif
+#if ENABLE_FEATURE_READLINK2
+#include <ntdef.h>
+#endif
 
 #if defined(__MINGW64_VERSION_MAJOR)
 #if ENABLE_GLOBBING
@@ -1060,6 +1063,68 @@ char *realpath(const char *path, char *resolved_path)
         return NULL;
 }
 
+#if ENABLE_FEATURE_READLINK2
+static wchar_t *normalize_ntpath(wchar_t *wbuf)
+{
+        int i;
+        /* fix absolute path prefixes */
+        if (wbuf[0] == '\\') {
+                /* strip NT namespace prefixes */
+                if (!wcsncmp(wbuf, L"\\??\\", 4) ||
+                    !wcsncmp(wbuf, L"\\\\?\\", 4))
+                        wbuf += 4;
+                else if (!wcsnicmp(wbuf, L"\\DosDevices\\", 12))
+                        wbuf += 12;
+                /* replace remaining '...UNC\' with '\\' */
+                if (!wcsnicmp(wbuf, L"UNC\\", 4)) {
+                        wbuf += 2;
+                        *wbuf = '\\';
+                }
+        }
+        /* convert backslashes to slashes */
+        for (i = 0; wbuf[i]; i++)
+                if (wbuf[i] == '\\')
+                        wbuf[i] = '/';
+        return wbuf;
+}
+
+#define SRPB rptr->SymbolicLinkReparseBuffer
+ssize_t readlink(const char *pathname, char *buf, size_t bufsiz)
+{
+        HANDLE h;
+
+        h = CreateFile(pathname, 0, 0, NULL, OPEN_EXISTING,
+                                FILE_FLAG_OPEN_REPARSE_POINT|FILE_FLAG_BACKUP_SEMANTICS, NULL);
+        if (h != INVALID_HANDLE_VALUE) {
+                DWORD nbytes;
+                BYTE rbuf[MAXIMUM_REPARSE_DATA_BUFFER_SIZE];
+                PREPARSE_DATA_BUFFER rptr = (PREPARSE_DATA_BUFFER)rbuf;
+                BOOL status;
+
+                status = DeviceIoControl(h, FSCTL_GET_REPARSE_POINT, NULL, 0,
+                                        rptr, sizeof(rbuf), &nbytes, NULL);
+                CloseHandle(h);
+
+                if (status && rptr->ReparseTag == IO_REPARSE_TAG_SYMLINK) {
+                        size_t len = SRPB.SubstituteNameLength/sizeof(WCHAR);
+                        WCHAR *name = SRPB.PathBuffer +
+                                                        SRPB.SubstituteNameOffset/sizeof(WCHAR);
+
+                        name[len] = 0;
+                        name = normalize_ntpath(name);
+                        len = wcslen(name);
+                        if (len > bufsiz)
+                                len = bufsiz;
+                        if (WideCharToMultiByte(CP_ACP, 0, name, len, buf, bufsiz, 0, 0)) {
+                                return len;
+                        }
+                }
+        }
+        errno = err_win_to_posix();
+        return -1;
+}
+#endif
+
 const char *get_busybox_exec_path(void)
 {
         static char *path = NULL;