From 57d9e90b0f1c26652f944173ae800a9b8e43ecf3 Mon Sep 17 00:00:00 2001
From: Vinzenz Schroeter <vinzenz.f.s@gmail.com>
Date: Fri, 11 Apr 2025 21:40:49 +0200
Subject: [PATCH] wip update to next servicepoint version

---
 Cargo.lock             |   9 ++-
 Cargo.toml             |   8 +--
 example/main.c         |   2 +-
 include/servicepoint.h |  85 +++++++++++-------------
 src/bitmap.rs          |  56 +++++++++-------
 src/bitvec.rs          |  18 +++---
 src/brightness_grid.rs |  36 ++++++-----
 src/char_grid.rs       |  16 ++---
 src/command.rs         | 143 ++++++++++++++++++++---------------------
 src/connection.rs      |  51 +++++++--------
 src/constants.rs       |   2 +-
 src/cp437_grid.rs      |  30 +++++----
 src/packet.rs          |  21 +++---
 13 files changed, 242 insertions(+), 235 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 9fcfa8f..40ece4f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -98,9 +98,9 @@ dependencies = [
 
 [[package]]
 name = "cbindgen"
-version = "0.27.0"
+version = "0.28.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3fce8dd7fcfcbf3a0a87d8f515194b49d6135acab73e18bd380d1d93bb1a15eb"
+checksum = "eadd868a2ce9ca38de7eeafdcec9c7065ef89b42b32f0839278d55f35c54d1ff"
 dependencies = [
  "clap",
  "heck",
@@ -407,9 +407,8 @@ dependencies = [
 
 [[package]]
 name = "servicepoint"
-version = "0.13.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "93b52049be55a15fe37c13249d7f96aa8a5de56e1a41838e74a822ee8316a0c4"
+version = "0.13.2"
+source = "git+https://git.berlin.ccc.de/servicepoint/servicepoint/?branch=next#fe67160974d9fed542eb37e5e9a202eaf6fe00dc"
 dependencies = [
  "bitvec",
  "bzip2",
diff --git a/Cargo.toml b/Cargo.toml
index 7750abc..9e52832 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,14 +15,14 @@ keywords = ["cccb", "cccb-servicepoint", "cbindgen"]
 crate-type = ["staticlib", "cdylib", "rlib"]
 
 [build-dependencies]
-cbindgen = "0.27.0"
+cbindgen = "0.28.0"
 
-[dependencies.servicepoint]
-version = "0.13.1"
-features = ["all_compressions"]
+[dependencies]
+servicepoint = { features = ["all_compressions"], git = "https://git.berlin.ccc.de/servicepoint/servicepoint/", branch = "next" }
 
 [lints.rust]
 missing-docs = "warn"
+unsafe_op_in_unsafe_fn = "warn"
 
 [package.metadata.docs.rs]
 all-features = true
diff --git a/example/main.c b/example/main.c
index 1454804..aeb811b 100644
--- a/example/main.c
+++ b/example/main.c
@@ -2,7 +2,7 @@
 #include "servicepoint.h"
 
 int main(void) {
-    SPConnection *connection = sp_connection_open("localhost:2342");
+    SPUdpConnection *connection = sp_connection_open("localhost:2342");
     if (connection == NULL)
         return 1;
 
diff --git a/include/servicepoint.h b/include/servicepoint.h
index d9cbe57..e631bc0 100644
--- a/include/servicepoint.h
+++ b/include/servicepoint.h
@@ -1,4 +1,4 @@
-/* Generated with cbindgen:0.27.0 */
+/* Generated with cbindgen:0.28.0 */
 
 /* Warning, this file is autogenerated by cbindgen. Don't modify this manually. */
 
@@ -168,19 +168,6 @@ typedef struct SPCharGrid SPCharGrid;
  */
 typedef struct SPCommand SPCommand;
 
-/**
- * A connection to the display.
- *
- * # Examples
- *
- * ```C
- * CConnection connection = sp_connection_open("172.23.42.29:2342");
- * if (connection != NULL)
- *     sp_connection_send_command(connection, sp_command_clear());
- * ```
- */
-typedef struct SPConnection SPConnection;
-
 /**
  * A C-wrapper for grid containing codepage 437 characters.
  *
@@ -202,6 +189,19 @@ typedef struct SPCp437Grid SPCp437Grid;
  */
 typedef struct SPPacket SPPacket;
 
+/**
+ * A connection to the display.
+ *
+ * # Examples
+ *
+ * ```C
+ * CConnection connection = sp_connection_open("172.23.42.29:2342");
+ * if (connection != NULL)
+ *     sp_connection_send_command(connection, sp_command_clear());
+ * ```
+ */
+typedef struct SPUdpConnection SPUdpConnection;
+
 /**
  * Represents a span of memory (`&mut [u8]` ) as a struct usable by C code.
  *
@@ -290,7 +290,7 @@ void sp_bitmap_fill(SPBitmap *bitmap, bool value);
  *
  * [SPCommand]: [crate::SPCommand]
  */
-void sp_bitmap_free(SPBitmap *bitmap);
+void sp_bitmap_free(SPBitmap **bitmap);
 
 /**
  * Gets the current value at the specified position in the [SPBitmap].
@@ -341,13 +341,18 @@ size_t sp_bitmap_height(const SPBitmap *bitmap);
  * - `width`: size in pixels in x-direction
  * - `height`: size in pixels in y-direction
  *
- * returns: [SPBitmap] that contains a copy of the provided data. Will never return NULL.
+ * returns: [SPBitmap] that contains a copy of the provided data, or NULL in case of an error.
+ *
+ * # Errors
+ *
+ * In the following cases, this function will return NULL:
+ *
+ * - when the dimensions and data size do not match exactly.
+ * - when the width is not dividable by 8
  *
  * # Panics
  *
  * - when `data` is NULL
- * - when the dimensions and data size do not match exactly.
- * - when the width is not dividable by 8
  *
  * # Safety
  *
@@ -370,9 +375,11 @@ SPBitmap *sp_bitmap_load(size_t width,
  * - `width`: size in pixels in x-direction
  * - `height`: size in pixels in y-direction
  *
- * returns: [SPBitmap] initialized to all pixels off. Will never return NULL.
+ * returns: [SPBitmap] initialized to all pixels off, or NULL in case of an error.
  *
- * # Panics
+ * # Errors
+ *
+ * In the following cases, this function will return NULL:
  *
  * - when the width is not dividable by 8
  *
@@ -1206,7 +1213,7 @@ SPCommand *sp_command_bitmap_linear_or(size_t offset,
 SPCommand *sp_command_bitmap_linear_win(size_t x,
                                         size_t y,
                                         SPBitmap *bitmap,
-                                        SPCompressionCode compression_code);
+                                        SPCompressionCode compression);
 
 /**
  * Set pixel data according to a xor-mask starting at the offset.
@@ -1449,21 +1456,7 @@ SPCommand *sp_command_utf8_data(size_t x,
                                 SPCharGrid *grid);
 
 /**
- * Creates a new instance of [SPConnection] for testing that does not actually send anything.
- *
- * returns: a new instance. Will never return NULL.
- *
- * # Safety
- *
- * The caller has to make sure that:
- *
- * - the returned instance is freed in some way, either by using a consuming function or
- *   by explicitly calling `sp_connection_free`.
- */
-SPConnection *sp_connection_fake(void);
-
-/**
- * Closes and deallocates a [SPConnection].
+ * Closes and deallocates a [SPUdpConnection].
  *
  * # Panics
  *
@@ -1473,13 +1466,13 @@ SPConnection *sp_connection_fake(void);
  *
  * The caller has to make sure that:
  *
- * - `connection` points to a valid [SPConnection]
+ * - `connection` points to a valid [SPUdpConnection]
  * - `connection` is not used concurrently or after this call
  */
-void sp_connection_free(SPConnection *connection);
+void sp_connection_free(SPUdpConnection *connection);
 
 /**
- * Creates a new instance of [SPConnection].
+ * Creates a new instance of [SPUdpConnection].
  *
  * returns: NULL if connection fails, or connected instance
  *
@@ -1494,10 +1487,10 @@ void sp_connection_free(SPConnection *connection);
  * - the returned instance is freed in some way, either by using a consuming function or
  *   by explicitly calling `sp_connection_free`.
  */
-SPConnection *sp_connection_open(const char *host);
+SPUdpConnection *sp_connection_open(const char *host);
 
 /**
- * Sends a [SPCommand] to the display using the [SPConnection].
+ * Sends a [SPCommand] to the display using the [SPUdpConnection].
  *
  * The passed `command` gets consumed.
  *
@@ -1512,15 +1505,15 @@ SPConnection *sp_connection_open(const char *host);
  *
  * The caller has to make sure that:
  *
- * - `connection` points to a valid instance of [SPConnection]
+ * - `connection` points to a valid instance of [SPUdpConnection]
  * - `command` points to a valid instance of [SPPacket]
  * - `command` is not used concurrently or after this call
  */
-bool sp_connection_send_command(const SPConnection *connection,
+bool sp_connection_send_command(const SPUdpConnection *connection,
                                 SPCommand *command);
 
 /**
- * Sends a [SPPacket] to the display using the [SPConnection].
+ * Sends a [SPPacket] to the display using the [SPUdpConnection].
  *
  * The passed `packet` gets consumed.
  *
@@ -1535,11 +1528,11 @@ bool sp_connection_send_command(const SPConnection *connection,
  *
  * The caller has to make sure that:
  *
- * - `connection` points to a valid instance of [SPConnection]
+ * - `connection` points to a valid instance of [SPUdpConnection]
  * - `packet` points to a valid instance of [SPPacket]
  * - `packet` is not used concurrently or after this call
  */
-bool sp_connection_send_packet(const SPConnection *connection,
+bool sp_connection_send_packet(const SPUdpConnection *connection,
                                SPPacket *packet);
 
 /**
diff --git a/src/bitmap.rs b/src/bitmap.rs
index 3313385..45993d8 100644
--- a/src/bitmap.rs
+++ b/src/bitmap.rs
@@ -3,7 +3,7 @@
 //! prefix `sp_bitmap_`
 
 use servicepoint::{DataRef, Grid};
-use std::ptr::NonNull;
+use std::ptr::{null_mut, NonNull};
 
 use crate::byte_slice::SPByteSlice;
 
@@ -26,9 +26,11 @@ pub struct SPBitmap(pub(crate) servicepoint::Bitmap);
 /// - `width`: size in pixels in x-direction
 /// - `height`: size in pixels in y-direction
 ///
-/// returns: [SPBitmap] initialized to all pixels off. Will never return NULL.
+/// returns: [SPBitmap] initialized to all pixels off, or NULL in case of an error.
 ///
-/// # Panics
+/// # Errors
+///
+/// In the following cases, this function will return NULL:
 ///
 /// - when the width is not dividable by 8
 ///
@@ -42,9 +44,12 @@ pub struct SPBitmap(pub(crate) servicepoint::Bitmap);
 pub unsafe extern "C" fn sp_bitmap_new(
     width: usize,
     height: usize,
-) -> NonNull<SPBitmap> {
-    let result = Box::new(SPBitmap(servicepoint::Bitmap::new(width, height)));
-    NonNull::from(Box::leak(result))
+) -> *mut SPBitmap {
+    if let Some(bitmap) = servicepoint::Bitmap::new(width, height) {
+        Box::leak(Box::new(SPBitmap(bitmap)))
+    }else {
+        std::ptr::null_mut()
+    }
 }
 
 /// Creates a new [SPBitmap] with a size matching the screen.
@@ -70,13 +75,18 @@ pub unsafe extern "C" fn sp_bitmap_new_screen_sized() -> NonNull<SPBitmap> {
 /// - `width`: size in pixels in x-direction
 /// - `height`: size in pixels in y-direction
 ///
-/// returns: [SPBitmap] that contains a copy of the provided data. Will never return NULL.
+/// returns: [SPBitmap] that contains a copy of the provided data, or NULL in case of an error.
+///
+/// # Errors
+///
+/// In the following cases, this function will return NULL:
+///
+/// - when the dimensions and data size do not match exactly.
+/// - when the width is not dividable by 8
 ///
 /// # Panics
 ///
 /// - when `data` is NULL
-/// - when the dimensions and data size do not match exactly.
-/// - when the width is not dividable by 8
 ///
 /// # Safety
 ///
@@ -91,12 +101,14 @@ pub unsafe extern "C" fn sp_bitmap_load(
     height: usize,
     data: *const u8,
     data_length: usize,
-) -> NonNull<SPBitmap> {
+) -> *mut SPBitmap {
     assert!(!data.is_null());
-    let data = std::slice::from_raw_parts(data, data_length);
-    let result =
-        Box::new(SPBitmap(servicepoint::Bitmap::load(width, height, data)));
-    NonNull::from(Box::leak(result))
+    let data = unsafe {std::slice::from_raw_parts(data, data_length)};
+    if let Ok(bitmap) = servicepoint::Bitmap::load(width, height, data) {
+        Box::leak(Box::new(SPBitmap(bitmap)))
+    }else {
+        std::ptr::null_mut()
+    }
 }
 
 /// Clones a [SPBitmap].
@@ -120,7 +132,7 @@ pub unsafe extern "C" fn sp_bitmap_clone(
     bitmap: *const SPBitmap,
 ) -> NonNull<SPBitmap> {
     assert!(!bitmap.is_null());
-    let result = Box::new(SPBitmap((*bitmap).0.clone()));
+    let result = Box::new(SPBitmap(unsafe {(*bitmap).0.clone()}));
     NonNull::from(Box::leak(result))
 }
 
@@ -142,7 +154,7 @@ pub unsafe extern "C" fn sp_bitmap_clone(
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitmap_free(bitmap: *mut SPBitmap) {
     assert!(!bitmap.is_null());
-    _ = Box::from_raw(bitmap);
+    _ = unsafe {Box::from_raw(bitmap)};
 }
 
 /// Gets the current value at the specified position in the [SPBitmap].
@@ -170,7 +182,7 @@ pub unsafe extern "C" fn sp_bitmap_get(
     y: usize,
 ) -> bool {
     assert!(!bitmap.is_null());
-    (*bitmap).0.get(x, y)
+    unsafe {(*bitmap).0.get(x, y)}
 }
 
 /// Sets the value of the specified position in the [SPBitmap].
@@ -202,7 +214,7 @@ pub unsafe extern "C" fn sp_bitmap_set(
     value: bool,
 ) {
     assert!(!bitmap.is_null());
-    (*bitmap).0.set(x, y, value);
+    unsafe {(*bitmap).0.set(x, y, value)};
 }
 
 /// Sets the state of all pixels in the [SPBitmap].
@@ -225,7 +237,7 @@ pub unsafe extern "C" fn sp_bitmap_set(
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitmap_fill(bitmap: *mut SPBitmap, value: bool) {
     assert!(!bitmap.is_null());
-    (*bitmap).0.fill(value);
+    unsafe {(*bitmap).0.fill(value)};
 }
 
 /// Gets the width in pixels of the [SPBitmap] instance.
@@ -246,7 +258,7 @@ pub unsafe extern "C" fn sp_bitmap_fill(bitmap: *mut SPBitmap, value: bool) {
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitmap_width(bitmap: *const SPBitmap) -> usize {
     assert!(!bitmap.is_null());
-    (*bitmap).0.width()
+    unsafe {(*bitmap).0.width()}
 }
 
 /// Gets the height in pixels of the [SPBitmap] instance.
@@ -267,7 +279,7 @@ pub unsafe extern "C" fn sp_bitmap_width(bitmap: *const SPBitmap) -> usize {
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitmap_height(bitmap: *const SPBitmap) -> usize {
     assert!(!bitmap.is_null());
-    (*bitmap).0.height()
+    unsafe {(*bitmap).0.height()}
 }
 
 /// Gets an unsafe reference to the data of the [SPBitmap] instance.
@@ -288,7 +300,7 @@ pub unsafe extern "C" fn sp_bitmap_unsafe_data_ref(
     bitmap: *mut SPBitmap,
 ) -> SPByteSlice {
     assert!(!bitmap.is_null());
-    let data = (*bitmap).0.data_ref_mut();
+    let data = unsafe {(*bitmap).0.data_ref_mut()};
     SPByteSlice {
         start: NonNull::new(data.as_mut_ptr_range().start).unwrap(),
         length: data.len(),
diff --git a/src/bitvec.rs b/src/bitvec.rs
index 484e849..ed96be5 100644
--- a/src/bitvec.rs
+++ b/src/bitvec.rs
@@ -79,7 +79,7 @@ pub unsafe extern "C" fn sp_bitvec_load(
     data_length: usize,
 ) -> NonNull<SPBitVec> {
     assert!(!data.is_null());
-    let data = std::slice::from_raw_parts(data, data_length);
+    let data = unsafe {std::slice::from_raw_parts(data, data_length)};
     let result = Box::new(SPBitVec(servicepoint::BitVec::from_slice(data)));
     NonNull::from(Box::leak(result))
 }
@@ -105,7 +105,7 @@ pub unsafe extern "C" fn sp_bitvec_clone(
     bit_vec: *const SPBitVec,
 ) -> NonNull<SPBitVec> {
     assert!(!bit_vec.is_null());
-    let result = Box::new((*bit_vec).clone());
+    let result = Box::new(unsafe {(*bit_vec).clone()});
     NonNull::from(Box::leak(result))
 }
 
@@ -127,7 +127,7 @@ pub unsafe extern "C" fn sp_bitvec_clone(
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitvec_free(bit_vec: *mut SPBitVec) {
     assert!(!bit_vec.is_null());
-    _ = Box::from_raw(bit_vec);
+    _ = unsafe {Box::from_raw(bit_vec)};
 }
 
 /// Gets the value of a bit from the [SPBitVec].
@@ -156,7 +156,7 @@ pub unsafe extern "C" fn sp_bitvec_get(
     index: usize,
 ) -> bool {
     assert!(!bit_vec.is_null());
-    *(*bit_vec).0.get(index).unwrap()
+    unsafe {*(*bit_vec).0.get(index).unwrap()}
 }
 
 /// Sets the value of a bit in the [SPBitVec].
@@ -185,7 +185,7 @@ pub unsafe extern "C" fn sp_bitvec_set(
     value: bool,
 ) {
     assert!(!bit_vec.is_null());
-    (*bit_vec).0.set(index, value)
+    unsafe {(*bit_vec).0.set(index, value)}
 }
 
 /// Sets the value of all bits in the [SPBitVec].
@@ -208,7 +208,7 @@ pub unsafe extern "C" fn sp_bitvec_set(
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitvec_fill(bit_vec: *mut SPBitVec, value: bool) {
     assert!(!bit_vec.is_null());
-    (*bit_vec).0.fill(value)
+    unsafe {(*bit_vec).0.fill(value)}
 }
 
 /// Gets the length of the [SPBitVec] in bits.
@@ -229,7 +229,7 @@ pub unsafe extern "C" fn sp_bitvec_fill(bit_vec: *mut SPBitVec, value: bool) {
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitvec_len(bit_vec: *const SPBitVec) -> usize {
     assert!(!bit_vec.is_null());
-    (*bit_vec).0.len()
+    unsafe {(*bit_vec).0.len()}
 }
 
 /// Returns true if length is 0.
@@ -250,7 +250,7 @@ pub unsafe extern "C" fn sp_bitvec_len(bit_vec: *const SPBitVec) -> usize {
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitvec_is_empty(bit_vec: *const SPBitVec) -> bool {
     assert!(!bit_vec.is_null());
-    (*bit_vec).0.is_empty()
+    unsafe {(*bit_vec).0.is_empty()}
 }
 
 /// Gets an unsafe reference to the data of the [SPBitVec] instance.
@@ -275,7 +275,7 @@ pub unsafe extern "C" fn sp_bitvec_unsafe_data_ref(
     bit_vec: *mut SPBitVec,
 ) -> SPByteSlice {
     assert!(!bit_vec.is_null());
-    let data = (*bit_vec).0.as_raw_mut_slice();
+    let data = unsafe {(*bit_vec).0.as_raw_mut_slice()};
     SPByteSlice {
         start: NonNull::new(data.as_mut_ptr_range().start).unwrap(),
         length: data.len(),
diff --git a/src/brightness_grid.rs b/src/brightness_grid.rs
index 83af008..cfd2589 100644
--- a/src/brightness_grid.rs
+++ b/src/brightness_grid.rs
@@ -77,14 +77,18 @@ pub unsafe extern "C" fn sp_brightness_grid_load(
     height: usize,
     data: *const u8,
     data_length: usize,
-) -> NonNull<SPBrightnessGrid> {
+) -> *mut SPBrightnessGrid {
     assert!(!data.is_null());
-    let data = std::slice::from_raw_parts(data, data_length);
-    let grid = servicepoint::ByteGrid::load(width, height, data);
-    let grid = servicepoint::BrightnessGrid::try_from(grid)
-        .expect("invalid brightness value");
-    let result = Box::new(SPBrightnessGrid(grid));
-    NonNull::from(Box::leak(result))
+    let data =unsafe { std::slice::from_raw_parts(data, data_length)};
+    let grid = match servicepoint::ByteGrid::load(width, height, data) {
+        None => return std::ptr::null_mut(),
+        Some(grid) => grid
+    };
+    if let Ok(grid )= servicepoint::BrightnessGrid::try_from(grid) {
+        Box::leak(Box::new(SPBrightnessGrid(grid)))
+    }else {
+        std::ptr::null_mut()
+    }
 }
 
 /// Clones a [SPBrightnessGrid].
@@ -112,7 +116,7 @@ pub unsafe extern "C" fn sp_brightness_grid_clone(
     brightness_grid: *const SPBrightnessGrid,
 ) -> NonNull<SPBrightnessGrid> {
     assert!(!brightness_grid.is_null());
-    let result = Box::new((*brightness_grid).clone());
+    let result = Box::new(unsafe {(*brightness_grid).clone()});
     NonNull::from(Box::leak(result))
 }
 
@@ -140,7 +144,7 @@ pub unsafe extern "C" fn sp_brightness_grid_free(
     brightness_grid: *mut SPBrightnessGrid,
 ) {
     assert!(!brightness_grid.is_null());
-    _ = Box::from_raw(brightness_grid);
+    _ = unsafe {Box::from_raw(brightness_grid)};
 }
 
 /// Gets the current value at the specified position.
@@ -170,7 +174,7 @@ pub unsafe extern "C" fn sp_brightness_grid_get(
     y: usize,
 ) -> u8 {
     assert!(!brightness_grid.is_null());
-    (*brightness_grid).0.get(x, y).into()
+    unsafe {(*brightness_grid).0.get(x, y)}.into()
 }
 
 /// Sets the value of the specified position in the [SPBrightnessGrid].
@@ -205,7 +209,7 @@ pub unsafe extern "C" fn sp_brightness_grid_set(
     assert!(!brightness_grid.is_null());
     let brightness = servicepoint::Brightness::try_from(value)
         .expect("invalid brightness value");
-    (*brightness_grid).0.set(x, y, brightness);
+    unsafe {(*brightness_grid).0.set(x, y, brightness)};
 }
 
 /// Sets the value of all cells in the [SPBrightnessGrid].
@@ -234,7 +238,7 @@ pub unsafe extern "C" fn sp_brightness_grid_fill(
     assert!(!brightness_grid.is_null());
     let brightness = servicepoint::Brightness::try_from(value)
         .expect("invalid brightness value");
-    (*brightness_grid).0.fill(brightness);
+    unsafe {(*brightness_grid).0.fill(brightness)};
 }
 
 /// Gets the width of the [SPBrightnessGrid] instance.
@@ -259,7 +263,7 @@ pub unsafe extern "C" fn sp_brightness_grid_width(
     brightness_grid: *const SPBrightnessGrid,
 ) -> usize {
     assert!(!brightness_grid.is_null());
-    (*brightness_grid).0.width()
+    unsafe {(*brightness_grid).0.width()}
 }
 
 /// Gets the height of the [SPBrightnessGrid] instance.
@@ -284,7 +288,7 @@ pub unsafe extern "C" fn sp_brightness_grid_height(
     brightness_grid: *const SPBrightnessGrid,
 ) -> usize {
     assert!(!brightness_grid.is_null());
-    (*brightness_grid).0.height()
+    unsafe {(*brightness_grid).0.height()}
 }
 
 /// Gets an unsafe reference to the data of the [SPBrightnessGrid] instance.
@@ -312,9 +316,9 @@ pub unsafe extern "C" fn sp_brightness_grid_unsafe_data_ref(
 ) -> SPByteSlice {
     assert!(!brightness_grid.is_null());
     assert_eq!(core::mem::size_of::<servicepoint::Brightness>(), 1);
-    let data = (*brightness_grid).0.data_ref_mut();
+    let data = unsafe {(*brightness_grid).0.data_ref_mut()};
     // this assumes more about the memory layout than rust guarantees. yikes!
-    let data: &mut [u8] = transmute(data);
+    let data: &mut [u8] = unsafe {transmute(data)};
     SPByteSlice {
         start: NonNull::new(data.as_mut_ptr_range().start).unwrap(),
         length: data.len(),
diff --git a/src/char_grid.rs b/src/char_grid.rs
index dfaf225..3c51e89 100644
--- a/src/char_grid.rs
+++ b/src/char_grid.rs
@@ -74,7 +74,7 @@ pub unsafe extern "C" fn sp_char_grid_load(
     data_length: usize,
 ) -> NonNull<SPCharGrid> {
     assert!(data.is_null());
-    let data = std::slice::from_raw_parts(data, data_length);
+    let data = unsafe {std::slice::from_raw_parts(data, data_length)};
     let result = Box::new(SPCharGrid(
         servicepoint::CharGrid::load_utf8(width, height, data.to_vec())
             .unwrap(),
@@ -103,7 +103,7 @@ pub unsafe extern "C" fn sp_char_grid_clone(
     char_grid: *const SPCharGrid,
 ) -> NonNull<SPCharGrid> {
     assert!(!char_grid.is_null());
-    let result = Box::new((*char_grid).clone());
+    let result = Box::new(unsafe{(*char_grid).clone()});
     NonNull::from(Box::leak(result))
 }
 
@@ -125,7 +125,7 @@ pub unsafe extern "C" fn sp_char_grid_clone(
 #[no_mangle]
 pub unsafe extern "C" fn sp_char_grid_free(char_grid: *mut SPCharGrid) {
     assert!(!char_grid.is_null());
-    _ = Box::from_raw(char_grid);
+    _ = unsafe {Box::from_raw(char_grid)};
 }
 
 /// Gets the current value at the specified position.
@@ -153,7 +153,7 @@ pub unsafe extern "C" fn sp_char_grid_get(
     y: usize,
 ) -> u32 {
     assert!(!char_grid.is_null());
-    (*char_grid).0.get(x, y) as u32
+    unsafe {(*char_grid).0.get(x, y) as u32}
 }
 
 /// Sets the value of the specified position in the [SPCharGrid].
@@ -187,7 +187,7 @@ pub unsafe extern "C" fn sp_char_grid_set(
     value: u32,
 ) {
     assert!(!char_grid.is_null());
-    (*char_grid).0.set(x, y, char::from_u32(value).unwrap());
+    unsafe {(*char_grid).0.set(x, y, char::from_u32(value).unwrap())};
 }
 
 /// Sets the value of all cells in the [SPCharGrid].
@@ -213,7 +213,7 @@ pub unsafe extern "C" fn sp_char_grid_fill(
     value: u32,
 ) {
     assert!(!char_grid.is_null());
-    (*char_grid).0.fill(char::from_u32(value).unwrap());
+    unsafe {(*char_grid).0.fill(char::from_u32(value).unwrap())};
 }
 
 /// Gets the width of the [SPCharGrid] instance.
@@ -236,7 +236,7 @@ pub unsafe extern "C" fn sp_char_grid_width(
     char_grid: *const SPCharGrid,
 ) -> usize {
     assert!(!char_grid.is_null());
-    (*char_grid).0.width()
+    unsafe {(*char_grid).0.width()}
 }
 
 /// Gets the height of the [SPCharGrid] instance.
@@ -259,5 +259,5 @@ pub unsafe extern "C" fn sp_char_grid_height(
     char_grid: *const SPCharGrid,
 ) -> usize {
     assert!(!char_grid.is_null());
-    (*char_grid).0.height()
+    unsafe {(*char_grid).0.height()}
 }
diff --git a/src/command.rs b/src/command.rs
index f7e50ea..0720db6 100644
--- a/src/command.rs
+++ b/src/command.rs
@@ -2,12 +2,12 @@
 //!
 //! prefix `sp_command_`
 
-use std::ptr::{null_mut, NonNull};
-
 use crate::{
     SPBitVec, SPBitmap, SPBrightnessGrid, SPCharGrid, SPCompressionCode,
     SPCp437Grid, SPPacket,
 };
+use servicepoint::{BinaryOperation, GlobalBrightnessCommand};
+use std::ptr::NonNull;
 
 /// A low-level display command.
 ///
@@ -23,7 +23,7 @@ use crate::{
 /// ```
 ///
 /// [SPConnection]: [crate::SPConnection]
-pub struct SPCommand(pub(crate) servicepoint::Command);
+pub struct SPCommand(pub(crate) servicepoint::TypedCommand);
 
 impl Clone for SPCommand {
     fn clone(&self) -> Self {
@@ -54,9 +54,9 @@ impl Clone for SPCommand {
 pub unsafe extern "C" fn sp_command_try_from_packet(
     packet: *mut SPPacket,
 ) -> *mut SPCommand {
-    let packet = *Box::from_raw(packet);
-    match servicepoint::Command::try_from(packet.0) {
-        Err(_) => null_mut(),
+    let packet = *unsafe{Box::from_raw(packet)};
+    match servicepoint::TypedCommand::try_from(packet.0) {
+        Err(_) => std::ptr::null_mut(),
         Ok(command) => Box::into_raw(Box::new(SPCommand(command))),
     }
 }
@@ -82,7 +82,7 @@ pub unsafe extern "C" fn sp_command_clone(
     command: *const SPCommand,
 ) -> NonNull<SPCommand> {
     assert!(!command.is_null());
-    let result = Box::new((*command).clone());
+    let result = Box::new(unsafe { (*command).clone() });
     NonNull::from(Box::leak(result))
 }
 
@@ -106,7 +106,7 @@ pub unsafe extern "C" fn sp_command_clone(
 ///   by explicitly calling `sp_command_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_command_clear() -> NonNull<SPCommand> {
-    let result = Box::new(SPCommand(servicepoint::Command::Clear));
+    let result = Box::new(SPCommand(servicepoint::ClearCommand.into()));
     NonNull::from(Box::leak(result))
 }
 
@@ -124,7 +124,7 @@ pub unsafe extern "C" fn sp_command_clear() -> NonNull<SPCommand> {
 ///   by explicitly calling `sp_command_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_command_hard_reset() -> NonNull<SPCommand> {
-    let result = Box::new(SPCommand(servicepoint::Command::HardReset));
+    let result = Box::new(SPCommand(servicepoint::HardResetCommand.into()));
     NonNull::from(Box::leak(result))
 }
 
@@ -140,7 +140,7 @@ pub unsafe extern "C" fn sp_command_hard_reset() -> NonNull<SPCommand> {
 ///   by explicitly calling `sp_command_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_command_fade_out() -> NonNull<SPCommand> {
-    let result = Box::new(SPCommand(servicepoint::Command::FadeOut));
+    let result = Box::new(SPCommand(servicepoint::FadeOutCommand.into()));
     NonNull::from(Box::leak(result))
 }
 
@@ -164,8 +164,7 @@ pub unsafe extern "C" fn sp_command_brightness(
 ) -> NonNull<SPCommand> {
     let brightness = servicepoint::Brightness::try_from(brightness)
         .expect("invalid brightness");
-    let result =
-        Box::new(SPCommand(servicepoint::Command::Brightness(brightness)));
+    let result = Box::new(SPCommand(GlobalBrightnessCommand::from(brightness).into()));
     NonNull::from(Box::leak(result))
 }
 
@@ -194,11 +193,11 @@ pub unsafe extern "C" fn sp_command_char_brightness(
     grid: *mut SPBrightnessGrid,
 ) -> NonNull<SPCommand> {
     assert!(!grid.is_null());
-    let byte_grid = *Box::from_raw(grid);
-    let result = Box::new(SPCommand(servicepoint::Command::CharBrightness(
-        servicepoint::Origin::new(x, y),
-        byte_grid.0,
-    )));
+    let byte_grid = unsafe { *Box::from_raw(grid) };
+    let result = Box::new(SPCommand(servicepoint::BrightnessGridCommand {
+        origin: servicepoint::Origin::new(x, y),
+        grid: byte_grid.0,
+    }.into()));
     NonNull::from(Box::leak(result))
 }
 
@@ -232,15 +231,8 @@ pub unsafe extern "C" fn sp_command_bitmap_linear(
     offset: usize,
     bit_vec: *mut SPBitVec,
     compression: SPCompressionCode,
-) -> NonNull<SPCommand> {
-    assert!(!bit_vec.is_null());
-    let bit_vec = *Box::from_raw(bit_vec);
-    let result = Box::new(SPCommand(servicepoint::Command::BitmapLinear(
-        offset,
-        bit_vec.into(),
-        compression.try_into().expect("invalid compression code"),
-    )));
-    NonNull::from(Box::leak(result))
+) -> *mut SPCommand {
+    unsafe {sp_command_bitmap_linear_internal(offset, bit_vec, compression, BinaryOperation::Overwrite)}
 }
 
 /// Set pixel data according to an and-mask starting at the offset.
@@ -273,15 +265,8 @@ pub unsafe extern "C" fn sp_command_bitmap_linear_and(
     offset: usize,
     bit_vec: *mut SPBitVec,
     compression: SPCompressionCode,
-) -> NonNull<SPCommand> {
-    assert!(!bit_vec.is_null());
-    let bit_vec = *Box::from_raw(bit_vec);
-    let result = Box::new(SPCommand(servicepoint::Command::BitmapLinearAnd(
-        offset,
-        bit_vec.into(),
-        compression.try_into().expect("invalid compression code"),
-    )));
-    NonNull::from(Box::leak(result))
+) -> *mut SPCommand {
+    unsafe {sp_command_bitmap_linear_internal(offset, bit_vec, compression, BinaryOperation::Xor)}
 }
 
 /// Set pixel data according to an or-mask starting at the offset.
@@ -314,15 +299,8 @@ pub unsafe extern "C" fn sp_command_bitmap_linear_or(
     offset: usize,
     bit_vec: *mut SPBitVec,
     compression: SPCompressionCode,
-) -> NonNull<SPCommand> {
-    assert!(!bit_vec.is_null());
-    let bit_vec = *Box::from_raw(bit_vec);
-    let result = Box::new(SPCommand(servicepoint::Command::BitmapLinearOr(
-        offset,
-        bit_vec.into(),
-        compression.try_into().expect("invalid compression code"),
-    )));
-    NonNull::from(Box::leak(result))
+) -> *mut SPCommand {
+    unsafe {sp_command_bitmap_linear_internal(offset, bit_vec, compression, BinaryOperation::Or)}
 }
 
 /// Set pixel data according to a xor-mask starting at the offset.
@@ -355,15 +333,30 @@ pub unsafe extern "C" fn sp_command_bitmap_linear_xor(
     offset: usize,
     bit_vec: *mut SPBitVec,
     compression: SPCompressionCode,
-) -> NonNull<SPCommand> {
+) -> *mut SPCommand {
+    unsafe {sp_command_bitmap_linear_internal(offset, bit_vec, compression, BinaryOperation::Xor)}
+}
+
+#[inline]
+unsafe fn sp_command_bitmap_linear_internal(
+    offset: usize,
+    bit_vec: *mut SPBitVec,
+    compression: SPCompressionCode,
+    operation: BinaryOperation
+) -> *mut SPCommand {
     assert!(!bit_vec.is_null());
-    let bit_vec = *Box::from_raw(bit_vec);
-    let result = Box::new(SPCommand(servicepoint::Command::BitmapLinearXor(
+    let bit_vec = unsafe { *Box::from_raw(bit_vec) };
+    let compression = match compression.try_into() {
+        Ok(compression) => compression,
+        Err(_) => return std::ptr::null_mut(),
+    };
+    let command = SPCommand(servicepoint::BitVecCommand {
         offset,
-        bit_vec.into(),
-        compression.try_into().expect("invalid compression code"),
-    )));
-    NonNull::from(Box::leak(result))
+        operation,
+        bitvec: bit_vec.into(),
+        compression,
+    }.into());
+    Box::leak(Box::new(command))
 }
 
 /// Show codepage 437 encoded text on the screen.
@@ -391,11 +384,12 @@ pub unsafe extern "C" fn sp_command_cp437_data(
     grid: *mut SPCp437Grid,
 ) -> NonNull<SPCommand> {
     assert!(!grid.is_null());
-    let grid = *Box::from_raw(grid);
-    let result = Box::new(SPCommand(servicepoint::Command::Cp437Data(
-        servicepoint::Origin::new(x, y),
-        grid.0,
-    )));
+    let grid = *unsafe{Box::from_raw(grid)};
+    let result = Box::new(SPCommand(servicepoint::Cp437GridCommand {
+        origin: servicepoint::Origin::new(x,
+                                          y),
+        grid: grid.0,
+    }.into()));
     NonNull::from(Box::leak(result))
 }
 
@@ -424,11 +418,12 @@ pub unsafe extern "C" fn sp_command_utf8_data(
     grid: *mut SPCharGrid,
 ) -> NonNull<SPCommand> {
     assert!(!grid.is_null());
-    let grid = *Box::from_raw(grid);
-    let result = Box::new(SPCommand(servicepoint::Command::Utf8Data(
-        servicepoint::Origin::new(x, y),
-        grid.0,
-    )));
+    let grid = unsafe { *Box::from_raw(grid) };
+    let result = Box::new(SPCommand(servicepoint::CharGridCommand {
+        origin: servicepoint::Origin::new(x,
+                                          y),
+        grid: grid.0,
+    }.into()));
     NonNull::from(Box::leak(result))
 }
 
@@ -457,18 +452,20 @@ pub unsafe extern "C" fn sp_command_bitmap_linear_win(
     x: usize,
     y: usize,
     bitmap: *mut SPBitmap,
-    compression_code: SPCompressionCode,
-) -> NonNull<SPCommand> {
+    compression: SPCompressionCode,
+) -> *mut SPCommand {
     assert!(!bitmap.is_null());
-    let byte_grid = (*Box::from_raw(bitmap)).0;
-    let result = Box::new(SPCommand(servicepoint::Command::BitmapLinearWin(
-        servicepoint::Origin::new(x, y),
-        byte_grid,
-        compression_code
-            .try_into()
-            .expect("invalid compression code"),
-    )));
-    NonNull::from(Box::leak(result))
+    let bitmap = unsafe { *Box::from_raw(bitmap) }.0;
+    let compression = match compression.try_into() {
+        Ok(compression) => compression,
+        Err(_) => return std::ptr::null_mut(),
+    };
+    let command = SPCommand(servicepoint::BitmapCommand {
+        origin: servicepoint::Origin::new(x, y),
+        bitmap,
+        compression,
+    }.into());
+    Box::leak(Box::new(command))
 }
 
 /// Deallocates a [SPCommand].
@@ -494,5 +491,5 @@ pub unsafe extern "C" fn sp_command_bitmap_linear_win(
 #[no_mangle]
 pub unsafe extern "C" fn sp_command_free(command: *mut SPCommand) {
     assert!(!command.is_null());
-    _ = Box::from_raw(command);
+    _ = unsafe { Box::from_raw(command) };
 }
diff --git a/src/connection.rs b/src/connection.rs
index 8b31243..6bbdbe2 100644
--- a/src/connection.rs
+++ b/src/connection.rs
@@ -3,8 +3,7 @@
 //! prefix `sp_connection_`
 
 use std::ffi::{c_char, CStr};
-use std::ptr::{null_mut, NonNull};
-
+use servicepoint::Connection;
 use crate::{SPCommand, SPPacket};
 
 /// A connection to the display.
@@ -16,7 +15,7 @@ use crate::{SPCommand, SPPacket};
 /// if (connection != NULL)
 ///     sp_connection_send_command(connection, sp_command_clear());
 /// ```
-pub struct SPConnection(pub(crate) servicepoint::Connection);
+pub struct SPConnection(pub(crate) servicepoint::UdpConnection);
 
 /// Creates a new instance of [SPConnection].
 ///
@@ -37,30 +36,30 @@ pub unsafe extern "C" fn sp_connection_open(
     host: *const c_char,
 ) -> *mut SPConnection {
     assert!(!host.is_null());
-    let host = CStr::from_ptr(host).to_str().expect("Bad encoding");
-    let connection = match servicepoint::Connection::open(host) {
-        Err(_) => return null_mut(),
+    let host = unsafe {CStr::from_ptr(host)}.to_str().expect("Bad encoding");
+    let connection = match servicepoint::UdpConnection::open(host) {
+        Err(_) => return std::ptr::null_mut(),
         Ok(value) => value,
     };
 
     Box::into_raw(Box::new(SPConnection(connection)))
 }
 
-/// Creates a new instance of [SPConnection] for testing that does not actually send anything.
-///
-/// returns: a new instance. Will never return NULL.
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - the returned instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_connection_free`.
-#[no_mangle]
-pub unsafe extern "C" fn sp_connection_fake() -> NonNull<SPConnection> {
-    let result = Box::new(SPConnection(servicepoint::Connection::Fake));
-    NonNull::from(Box::leak(result))
-}
+// /// Creates a new instance of [SPUdpConnection] for testing that does not actually send anything.
+// ///
+// /// returns: a new instance. Will never return NULL.
+// ///
+// /// # Safety
+// ///
+// /// The caller has to make sure that:
+// ///
+// /// - the returned instance is freed in some way, either by using a consuming function or
+// ///   by explicitly calling `sp_connection_free`.
+// #[no_mangle]
+// pub unsafe extern "C" fn sp_connection_fake() -> NonNull<SPUdpConnection> {
+//     let result = Box::new(SPUdpConnection(servicepoint::Connection::Fake));
+//     NonNull::from(Box::leak(result))
+// }
 
 /// Sends a [SPPacket] to the display using the [SPConnection].
 ///
@@ -87,8 +86,8 @@ pub unsafe extern "C" fn sp_connection_send_packet(
 ) -> bool {
     assert!(!connection.is_null());
     assert!(!packet.is_null());
-    let packet = Box::from_raw(packet);
-    (*connection).0.send((*packet).0).is_ok()
+    let packet = unsafe {Box::from_raw(packet)};
+    unsafe {(*connection).0.send((*packet).0)}.is_ok()
 }
 
 /// Sends a [SPCommand] to the display using the [SPConnection].
@@ -116,8 +115,8 @@ pub unsafe extern "C" fn sp_connection_send_command(
 ) -> bool {
     assert!(!connection.is_null());
     assert!(!command.is_null());
-    let command = (*Box::from_raw(command)).0;
-    (*connection).0.send(command).is_ok()
+    let command = (*unsafe {Box::from_raw(command)}).0;
+    unsafe{(*connection).0.send(command)}.is_ok()
 }
 
 /// Closes and deallocates a [SPConnection].
@@ -135,5 +134,5 @@ pub unsafe extern "C" fn sp_connection_send_command(
 #[no_mangle]
 pub unsafe extern "C" fn sp_connection_free(connection: *mut SPConnection) {
     assert!(!connection.is_null());
-    _ = Box::from_raw(connection);
+    _ = unsafe {Box::from_raw(connection)};
 }
diff --git a/src/constants.rs b/src/constants.rs
index 1a268f4..ed4e52d 100644
--- a/src/constants.rs
+++ b/src/constants.rs
@@ -43,6 +43,6 @@ impl TryFrom<SPCompressionCode> for CompressionCode {
     type Error = ();
 
     fn try_from(value: SPCompressionCode) -> Result<Self, Self::Error> {
-        CompressionCode::try_from(value as u16)
+        CompressionCode::try_from(value as u16).map_err(|_|())
     }
 }
diff --git a/src/cp437_grid.rs b/src/cp437_grid.rs
index 9b366c8..712034c 100644
--- a/src/cp437_grid.rs
+++ b/src/cp437_grid.rs
@@ -69,13 +69,15 @@ pub unsafe extern "C" fn sp_cp437_grid_load(
     height: usize,
     data: *const u8,
     data_length: usize,
-) -> NonNull<SPCp437Grid> {
+) -> *mut SPCp437Grid {
     assert!(data.is_null());
-    let data = std::slice::from_raw_parts(data, data_length);
-    let result = Box::new(SPCp437Grid(servicepoint::Cp437Grid::load(
-        width, height, data,
-    )));
-    NonNull::from(Box::leak(result))
+    let data = unsafe{std::slice::from_raw_parts(data, data_length)};
+    let grid = servicepoint::Cp437Grid::load(        width, height, data,    );
+    if let Some(grid ) = grid {
+        Box::leak(Box::new(SPCp437Grid(grid)))
+    } else {
+        std::ptr::null_mut()
+    }
 }
 
 /// Clones a [SPCp437Grid].
@@ -99,7 +101,7 @@ pub unsafe extern "C" fn sp_cp437_grid_clone(
     cp437_grid: *const SPCp437Grid,
 ) -> NonNull<SPCp437Grid> {
     assert!(!cp437_grid.is_null());
-    let result = Box::new((*cp437_grid).clone());
+    let result = Box::new(unsafe {(*cp437_grid).clone()});
     NonNull::from(Box::leak(result))
 }
 
@@ -121,7 +123,7 @@ pub unsafe extern "C" fn sp_cp437_grid_clone(
 #[no_mangle]
 pub unsafe extern "C" fn sp_cp437_grid_free(cp437_grid: *mut SPCp437Grid) {
     assert!(!cp437_grid.is_null());
-    _ = Box::from_raw(cp437_grid);
+    _ = unsafe {Box::from_raw(cp437_grid)};
 }
 
 /// Gets the current value at the specified position.
@@ -149,7 +151,7 @@ pub unsafe extern "C" fn sp_cp437_grid_get(
     y: usize,
 ) -> u8 {
     assert!(!cp437_grid.is_null());
-    (*cp437_grid).0.get(x, y)
+    unsafe{(*cp437_grid).0.get(x, y)}
 }
 
 /// Sets the value of the specified position in the [SPCp437Grid].
@@ -183,7 +185,7 @@ pub unsafe extern "C" fn sp_cp437_grid_set(
     value: u8,
 ) {
     assert!(!cp437_grid.is_null());
-    (*cp437_grid).0.set(x, y, value);
+    unsafe {(*cp437_grid).0.set(x, y, value)};
 }
 
 /// Sets the value of all cells in the [SPCp437Grid].
@@ -209,7 +211,7 @@ pub unsafe extern "C" fn sp_cp437_grid_fill(
     value: u8,
 ) {
     assert!(!cp437_grid.is_null());
-    (*cp437_grid).0.fill(value);
+    unsafe {(*cp437_grid).0.fill(value)};
 }
 
 /// Gets the width of the [SPCp437Grid] instance.
@@ -232,7 +234,7 @@ pub unsafe extern "C" fn sp_cp437_grid_width(
     cp437_grid: *const SPCp437Grid,
 ) -> usize {
     assert!(!cp437_grid.is_null());
-    (*cp437_grid).0.width()
+    unsafe {(*cp437_grid).0.width()}
 }
 
 /// Gets the height of the [SPCp437Grid] instance.
@@ -255,7 +257,7 @@ pub unsafe extern "C" fn sp_cp437_grid_height(
     cp437_grid: *const SPCp437Grid,
 ) -> usize {
     assert!(!cp437_grid.is_null());
-    (*cp437_grid).0.height()
+    unsafe {(*cp437_grid).0.height()}
 }
 
 /// Gets an unsafe reference to the data of the [SPCp437Grid] instance.
@@ -277,7 +279,7 @@ pub unsafe extern "C" fn sp_cp437_grid_height(
 pub unsafe extern "C" fn sp_cp437_grid_unsafe_data_ref(
     cp437_grid: *mut SPCp437Grid,
 ) -> SPByteSlice {
-    let data = (*cp437_grid).0.data_ref_mut();
+    let data = unsafe {(*cp437_grid).0.data_ref_mut()};
     SPByteSlice {
         start: NonNull::new(data.as_mut_ptr_range().start).unwrap(),
         length: data.len(),
diff --git a/src/packet.rs b/src/packet.rs
index 9293a8a..12afb34 100644
--- a/src/packet.rs
+++ b/src/packet.rs
@@ -2,7 +2,7 @@
 //!
 //! prefix `sp_packet_`
 
-use std::ptr::{null_mut, NonNull};
+use std::ptr::{NonNull};
 
 use crate::SPCommand;
 
@@ -29,11 +29,12 @@ pub struct SPPacket(pub(crate) servicepoint::Packet);
 #[no_mangle]
 pub unsafe extern "C" fn sp_packet_from_command(
     command: *mut SPCommand,
-) -> NonNull<SPPacket> {
+) -> *mut SPPacket {
     assert!(!command.is_null());
-    let command = *Box::from_raw(command);
-    let result = Box::new(SPPacket(command.0.into()));
-    NonNull::from(Box::leak(result))
+    let command = unsafe {*Box::from_raw(command)};
+    if let Ok(packet) = command.0.try_into() {
+        Box::leak(Box::new(SPPacket(packet)))
+    } else { std::ptr::null_mut() }
 }
 
 /// Tries to load a [SPPacket] from the passed array with the specified length.
@@ -58,9 +59,9 @@ pub unsafe extern "C" fn sp_packet_try_load(
     length: usize,
 ) -> *mut SPPacket {
     assert!(!data.is_null());
-    let data = std::slice::from_raw_parts(data, length);
+    let data = unsafe {std::slice::from_raw_parts(data, length)};
     match servicepoint::Packet::try_from(data) {
-        Err(_) => null_mut(),
+        Err(_) => std::ptr::null_mut(),
         Ok(packet) => Box::into_raw(Box::new(SPPacket(packet))),
     }
 }
@@ -104,7 +105,7 @@ pub unsafe extern "C" fn sp_packet_from_parts(
     let payload = if payload.is_null() {
         vec![]
     } else {
-        let payload = std::slice::from_raw_parts(payload, payload_len);
+        let payload = unsafe {std::slice::from_raw_parts(payload, payload_len) };
         Vec::from(payload)
     };
 
@@ -143,7 +144,7 @@ pub unsafe extern "C" fn sp_packet_clone(
     packet: *const SPPacket,
 ) -> NonNull<SPPacket> {
     assert!(!packet.is_null());
-    let result = Box::new(SPPacket((*packet).0.clone()));
+    let result = Box::new(SPPacket(unsafe {(*packet).0.clone()}));
     NonNull::from(Box::leak(result))
 }
 
@@ -162,5 +163,5 @@ pub unsafe extern "C" fn sp_packet_clone(
 #[no_mangle]
 pub unsafe extern "C" fn sp_packet_free(packet: *mut SPPacket) {
     assert!(!packet.is_null());
-    _ = Box::from_raw(packet)
+    _ = unsafe {Box::from_raw(packet)}
 }