From c174d3a544b92be55bc0d09443522386363129f5 Mon Sep 17 00:00:00 2001
From: James Buren <braewoods+rb@braewoods.net>
Date: Wed, 7 Jul 2021 21:06:31 +0000
Subject: file/fat: add utime function

This emulates the traditional utime function from UNIX clones to allow
for manual updates of the modification timestamp on files and directories.

This should only prove useful for non-native targets as those usually
have a libc version of utime.

Change-Id: Iea8a1d328e78b92c400d3354ee80689c7cf53af8
---
 firmware/common/file.c               | 38 ++++++++++++++++++++++++++++++++++++
 firmware/drivers/fat.c               | 35 +++++++++++++++++++++++++++++++++
 firmware/export/fat.h                |  2 ++
 firmware/include/file.h              |  3 +++
 firmware/include/filesystem-native.h |  3 +++
 firmware/libc/include/time.h         |  6 ++++++
 6 files changed, 87 insertions(+)

diff --git a/firmware/common/file.c b/firmware/common/file.c
index cb918c6eab..c090c40be5 100644
--- a/firmware/common/file.c
+++ b/firmware/common/file.c
@@ -1123,6 +1123,44 @@ file_error:
     return rc;
 }
 
+int utime(const char *path, const struct utimbuf* times)
+{
+    DEBUGF("utime(path=\"%s\",times->modtime=%u)\n", path, times->modtime);
+
+    int rc, open1rc = -1;
+    struct filestr_base pathstr;
+    struct path_component_info pathinfo;
+
+    file_internal_lock_WRITER();
+
+    if (!times)
+        FILE_ERROR(EINVAL, -1);
+
+    open1rc = open_stream_internal(path, FF_ANYTYPE | FF_PARENTINFO,
+                                   &pathstr, &pathinfo);
+    if (open1rc <= 0)
+    {
+        DEBUGF("Failed opening path: %d\n", open1rc);
+        if (open1rc == 0)
+            FILE_ERROR(ENOENT, -2);
+        else
+            FILE_ERROR(ERRNO, open1rc * 10 - 1);
+    }
+
+    rc = fat_utime(&pathinfo.parentinfo.fatfile, pathstr.fatstr.fatfilep,
+                   times);
+    if (rc < 0)
+    {
+        DEBUGF("I/O error during utime: %d\n", rc);
+        FILE_ERROR(ERRNO, rc * 10 - 2);
+    }
+
+file_error:
+    if (open1rc >= 0)
+        close_stream_internal(&pathstr);
+    file_internal_unlock_WRITER();
+    return rc;
+}
 
 /** Extensions **/
 
diff --git a/firmware/drivers/fat.c b/firmware/drivers/fat.c
index cc9735d0f7..28d4eb1987 100644
--- a/firmware/drivers/fat.c
+++ b/firmware/drivers/fat.c
@@ -2276,6 +2276,41 @@ fat_error:
     return rc;
 }
 
+int fat_utime(struct fat_file *parent, struct fat_file *file,
+              const struct utimbuf *times)
+{
+    struct bpb * const fat_bpb = FAT_BPB(parent->volume);
+
+    if (!fat_bpb)
+        return -1;
+
+    int rc;
+
+    struct fat_filestr parentstr;
+    fat_filestr_init(&parentstr, parent);
+
+    dc_lock_cache();
+
+    union raw_dirent *ent = cache_direntry(fat_bpb, &parentstr, file->e.entry);
+    if (!ent)
+        FAT_ERROR(-2);
+
+    uint16_t date;
+    uint16_t time;
+    dostime_localtime(times->modtime, &date, &time);
+
+    ent->wrttime    = htole16(time);
+    ent->wrtdate    = htole16(date);
+    ent->lstaccdate = htole16(date);
+
+    dc_dirty_buf(ent);
+
+    rc = 0;
+fat_error:
+    dc_unlock_cache();
+    cache_commit(fat_bpb);
+    return rc;
+}
 
 /** File stream functions **/
 
diff --git a/firmware/export/fat.h b/firmware/export/fat.h
index 27c2a161f6..b83ceeec0d 100644
--- a/firmware/export/fat.h
+++ b/firmware/export/fat.h
@@ -140,6 +140,8 @@ enum fat_remove_op           /* what should fat_remove(), remove? */
 int fat_remove(struct fat_file *file, enum fat_remove_op what);
 int fat_rename(struct fat_file *parent, struct fat_file *file,
                const unsigned char *newname);
+int fat_utime(struct fat_file *parent, struct fat_file *file,
+              const struct utimbuf *utimes);
 
 /** File stream functions **/
 int fat_closewrite(struct fat_filestr *filestr, uint32_t size,
diff --git a/firmware/include/file.h b/firmware/include/file.h
index 040f48dfc5..f17f14f98e 100644
--- a/firmware/include/file.h
+++ b/firmware/include/file.h
@@ -85,6 +85,9 @@ int fdprintf(int fildes, const char *fmt, ...) ATTRIBUTE_PRINTF(2, 3);
 #ifndef rename
 #define rename          FS_PREFIX(rename)
 #endif
+#ifndef utime
+#define utime           FS_PREFIX(utime)
+#endif
 #ifndef filesize
 #define filesize        FS_PREFIX(filesize)
 #endif
diff --git a/firmware/include/filesystem-native.h b/firmware/include/filesystem-native.h
index 640e179890..800e7bb23b 100644
--- a/firmware/include/filesystem-native.h
+++ b/firmware/include/filesystem-native.h
@@ -43,6 +43,8 @@
 #define __OPEN_MODE_ARG
 #define __CREAT_MODE_ARG
 
+#include <time.h>
+
 int     open(const char *name, int oflag);
 int     creat(const char *name);
 int     close(int fildes);
@@ -53,6 +55,7 @@ ssize_t read(int fildes, void *buf, size_t nbyte);
 ssize_t write(int fildes, const void *buf, size_t nbyte);
 int     remove(const char *path);
 int     rename(const char *old, const char *new);
+int     utime(const char *path, const struct utimbuf* times);
 off_t   filesize(int fildes);
 int     fsamefile(int fildes1, int fildes2);
 int     relate(const char *path1, const char *path2);
diff --git a/firmware/libc/include/time.h b/firmware/libc/include/time.h
index 4796b8b083..217b454321 100644
--- a/firmware/libc/include/time.h
+++ b/firmware/libc/include/time.h
@@ -28,6 +28,12 @@ struct tm
 #if !defined(_TIME_T_DEFINED) && !defined(_TIME_T_DECLARED)
 typedef long time_t;
 
+struct utimbuf
+{
+    time_t actime;
+    time_t modtime;
+};
+
 /* this define below is used by the mingw headers to prevent duplicate
    typedefs */
 #define _TIME_T_DEFINED
-- 
cgit v1.2.3