Add devoptab support to replace the libioushax devoptab

source/devoptab/devoptab_fsa_seek.cpp

@@ -0,0 +1,78 @@
+#include "devoptab_fsa.h"
+#include "logger.h"
+#include <mutex>
+
+off_t __fsa_seek(struct _reent *r,
+                 void *fd,
+                 off_t pos,
+                 int whence) {
+    FSError status;
+    FSAStat fsStat;
+    uint64_t offset;
+
+    if (!fd) {
+        r->_errno = EINVAL;
+        return -1;
+    }
+
+    auto *file = (__fsa_file_t *) fd;
+
+    auto *deviceData = (FSADeviceData *) r->deviceData;
+
+    std::lock_guard<MutexWrapper> lock(file->mutex);
+
+    // Find the offset to see from
+    switch (whence) {
+        case SEEK_SET: { // Set absolute position; start offset is 0
+            offset = 0;
+            break;
+        }
+        case SEEK_CUR: { // Set position relative to the current position
+            offset = file->offset;
+            break;
+        }
+        case SEEK_END: { // Set position relative to the end of the file
+            status = FSAGetStatFile(deviceData->clientHandle, file->fd, &fsStat);
+            if (status < 0) {
+                DEBUG_FUNCTION_LINE_ERR("FSAGetStatFile(0x%08X, 0x%08X, 0x%08X) (%s) failed: %s",
+                                        deviceData->clientHandle, file->fd, &fsStat, file->fullPath, FSAGetStatusStr(status));
+                r->_errno = __fsa_translate_error(status);
+                return -1;
+            }
+            offset = fsStat.size;
+            break;
+        }
+        default: { // An invalid option was provided
+            r->_errno = EINVAL;
+            return -1;
+        }
+    }
+
+    if (pos < 0 && (off_t) offset < -pos) {
+        // Don't allow seek to before the beginning of the file
+        r->_errno = EINVAL;
+        return -1;
+    } else if (offset + pos > UINT32_MAX) {
+        // Check for overflow
+        r->_errno = EINVAL;
+        return -1;
+    }
+
+    if ((uint32_t) (offset + pos) == file->offset) {
+        return file->offset;
+    }
+
+    uint32_t old_pos = file->offset;
+    file->offset     = offset + pos;
+
+    status = FSASetPosFile(deviceData->clientHandle, file->fd, file->offset);
+    if (status < 0) {
+        DEBUG_FUNCTION_LINE_ERR("FSASetPosFile(0x%08X, 0x%08X, 0x%08X) (%s) failed: %s",
+                                deviceData->clientHandle, file->fd, file->offset, file->fullPath, FSAGetStatusStr(status));
+        file->offset = old_pos;
+        r->_errno    = __fsa_translate_error(status);
+        return -1;
+    }
+
+    return file->offset;
+}