frame_validator.c File Reference

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Functions
bool	frame_validate_integrity (const char *frame_data, size_t frame_size)
	Validate ASCII frame integrity.
size_t	frame_get_valid_end (const char *frame_data, size_t frame_size)
	Get the actual valid frame end position.

Function Documentation

frame_get_valid_end()

size_t frame_get_valid_end	(	const char *	frame_data,
		size_t	frame_size )

Get the actual valid frame end position.

Finds where the frame SHOULD end (right after ESC[0m reset sequence). Returns the position after the final reset, or frame_size if no reset found.

Parameters

frame_data	Frame buffer
frame_size	Buffer size

Returns

Position where frame should end

Definition at line 70 of file video/ascii/frame_validator.c.

                                                                      {
  if (!frame_data || frame_size < 4) {
    return frame_size;
  }
 
  size_t reset_pos = frame_find_final_reset(frame_data, frame_size);
  if (reset_pos == SIZE_MAX) {
    return frame_size; // No reset found, assume all data is valid
  }
 
  return reset_pos + 4; // Return position after the reset sequence
}

frame_validate_integrity()

bool frame_validate_integrity	(	const char *	frame_data,
		size_t	frame_size )

Validate ASCII frame integrity.

Checks for common corruption patterns:

• Frame ends with proper reset sequence ESC[0m
• No garbage bytes after reset sequence
• Frame is properly null-terminated

Parameters

frame_data	Frame buffer (may not be null-terminated)
frame_size	Actual frame size in bytes

Returns

true if frame appears valid, false if corruption detected

Definition at line 34 of file video/ascii/frame_validator.c.

                                                                         {
  if (!frame_data || frame_size == 0) {
    return false;
  }
 
  size_t reset_pos = frame_find_final_reset(frame_data, frame_size);
  if (reset_pos == SIZE_MAX) {
    // No reset sequence found - this is suspicious
    log_warn("FRAME_VALIDATION: No ESC[0m reset sequence found in %zu byte frame", frame_size);
    return false;
  }
 
  size_t expected_end = reset_pos + 4; // 4 bytes for ESC[0m
 
  // Check if there's garbage after the reset
  if (expected_end < frame_size) {
    // Calculate how much garbage we have
    size_t garbage_size = frame_size - expected_end;
 
    // Check what the garbage looks like
    const uint8_t *garbage = (const uint8_t *)&frame_data[expected_end];
 
    // Log the garbage for debugging
    log_warn("FRAME_VALIDATION: Found %zu garbage bytes after reset at offset %zu (frame size %zu): "
             "[%02x %02x %02x %02x ...]",
             garbage_size, expected_end, frame_size, garbage[0], garbage_size > 1 ? garbage[1] : 0,
             garbage_size > 2 ? garbage[2] : 0, garbage_size > 3 ? garbage[3] : 0);
 
    return false;
  }
 
  // Frame looks valid
  log_debug("FRAME_VALIDATION: Frame OK (%zu bytes, ends at offset %zu)", frame_size, expected_end);
  return true;
}

References log_debug, and log_warn.