Add constants to socket module for ISO-TP CAN protocol

Co-authored-by: Stefan Tatschner <stefan@rumpelsepp.org>

Author: Patrick Menschel

Doc/whatsnew/3.15.rst

@@ -368,6 +368,13 @@ shelve
   (Contributed by Andrea Oliveri in :gh:`134004`.)
 
 
+socket
+------
+
+Add constants for the ISO-TP CAN protocol.
+(Contributed by Patrick Menschel and Stefan Tatschner in :gh:`86819`.)
+
+
 sqlite3
 -------
 

Lib/test/test_socket.py

@@ -2392,6 +2392,45 @@ def testCrucialConstants(self):
         socket.CAN_ISOTP
         socket.SOCK_DGRAM
 
+    @unittest.skipUnless(hasattr(socket, "SOL_CAN_ISOTP"),
+                         "missing <linux/can/isotp.h>")
+    def testISOTP(self):
+        socket.SOL_CAN_ISOTP
+
+        socket.CAN_ISOTP_OPTS
+        socket.CAN_ISOTP_RECV_FC
+
+        socket.CAN_ISOTP_TX_STMIN
+        socket.CAN_ISOTP_RX_STMIN
+        socket.CAN_ISOTP_LL_OPTS
+
+        socket.CAN_ISOTP_LISTEN_MODE
+        socket.CAN_ISOTP_EXTEND_ADDR
+        socket.CAN_ISOTP_TX_PADDING
+        socket.CAN_ISOTP_RX_PADDING
+        socket.CAN_ISOTP_CHK_PAD_LEN
+        socket.CAN_ISOTP_CHK_PAD_DATA
+        socket.CAN_ISOTP_HALF_DUPLEX
+        socket.CAN_ISOTP_FORCE_TXSTMIN
+        socket.CAN_ISOTP_FORCE_RXSTMIN
+        socket.CAN_ISOTP_RX_EXT_ADDR
+        socket.CAN_ISOTP_WAIT_TX_DONE
+        # This constant is not always available
+        # socket.CAN_ISOTP_SF_BROADCAST
+
+        socket.CAN_ISOTP_DEFAULT_FLAGS
+        socket.CAN_ISOTP_DEFAULT_EXT_ADDRESS
+        socket.CAN_ISOTP_DEFAULT_PAD_CONTENT
+        socket.CAN_ISOTP_DEFAULT_FRAME_TXTIME
+        socket.CAN_ISOTP_DEFAULT_RECV_BS
+        socket.CAN_ISOTP_DEFAULT_EXT_ADDRESS
+        socket.CAN_ISOTP_DEFAULT_RECV_STMIN
+        socket.CAN_ISOTP_DEFAULT_RECV_WFTMAX
+
+        socket.CAN_ISOTP_DEFAULT_LL_MTU
+        socket.CAN_ISOTP_DEFAULT_LL_TX_DL
+        socket.CAN_ISOTP_DEFAULT_LL_TX_FLAGS
+
     def testCreateSocket(self):
         with socket.socket(socket.PF_CAN, socket.SOCK_RAW, socket.CAN_RAW) as s:
             pass

Misc/NEWS.d/next/Library/2025-08-22-09-53-45.gh-issue-86819.ECxvwx.rst

@@ -0,0 +1 @@
+:mod:`socket`: Add missing constants for ISO-TP sockets.

Modules/socketmodule.c

@@ -8536,6 +8536,43 @@ socket_exec(PyObject *m)
 
     ADD_INT_MACRO(m, J1939_FILTER_MAX);
 #endif
+#ifdef HAVE_LINUX_CAN_ISOTP_H
+    ADD_INT_MACRO(m, SOL_CAN_ISOTP);
+
+    ADD_INT_MACRO(m, CAN_ISOTP_OPTS);
+    ADD_INT_MACRO(m, CAN_ISOTP_RECV_FC);
+
+    ADD_INT_MACRO(m, CAN_ISOTP_TX_STMIN);
+    ADD_INT_MACRO(m, CAN_ISOTP_RX_STMIN);
+    ADD_INT_MACRO(m, CAN_ISOTP_LL_OPTS);
+
+    ADD_INT_MACRO(m, CAN_ISOTP_LISTEN_MODE);
+    ADD_INT_MACRO(m, CAN_ISOTP_EXTEND_ADDR);
+    ADD_INT_MACRO(m, CAN_ISOTP_TX_PADDING);
+    ADD_INT_MACRO(m, CAN_ISOTP_RX_PADDING);
+    ADD_INT_MACRO(m, CAN_ISOTP_CHK_PAD_LEN);
+    ADD_INT_MACRO(m, CAN_ISOTP_CHK_PAD_DATA);
+    ADD_INT_MACRO(m, CAN_ISOTP_HALF_DUPLEX);
+    ADD_INT_MACRO(m, CAN_ISOTP_FORCE_TXSTMIN);
+    ADD_INT_MACRO(m, CAN_ISOTP_FORCE_RXSTMIN);
+    ADD_INT_MACRO(m, CAN_ISOTP_RX_EXT_ADDR);
+    ADD_INT_MACRO(m, CAN_ISOTP_WAIT_TX_DONE);
+#ifdef CAN_ISOTP_SF_BROADCAST
+    ADD_INT_MACRO(m, CAN_ISOTP_SF_BROADCAST);
+#endif
+
+    ADD_INT_MACRO(m, CAN_ISOTP_DEFAULT_FLAGS);
+    ADD_INT_MACRO(m, CAN_ISOTP_DEFAULT_EXT_ADDRESS);
+    ADD_INT_MACRO(m, CAN_ISOTP_DEFAULT_PAD_CONTENT);
+    ADD_INT_MACRO(m, CAN_ISOTP_DEFAULT_FRAME_TXTIME);
+    ADD_INT_MACRO(m, CAN_ISOTP_DEFAULT_RECV_BS);
+    ADD_INT_MACRO(m, CAN_ISOTP_DEFAULT_RECV_STMIN);
+    ADD_INT_MACRO(m, CAN_ISOTP_DEFAULT_RECV_WFTMAX);
+
+    ADD_INT_MACRO(m, CAN_ISOTP_DEFAULT_LL_MTU);
+    ADD_INT_MACRO(m, CAN_ISOTP_DEFAULT_LL_TX_DL);
+    ADD_INT_MACRO(m, CAN_ISOTP_DEFAULT_LL_TX_FLAGS);
+#endif
 #ifdef SOL_RDS
     ADD_INT_MACRO(m, SOL_RDS);
 #endif

Modules/socketmodule.h

@@ -165,6 +165,10 @@ typedef int socklen_t;
 #include <linux/can/bcm.h>
 #endif
 
+#ifdef HAVE_LINUX_CAN_ISOTP_H
+#include <linux/can/isotp.h>
+#endif
+
 #ifdef HAVE_LINUX_CAN_J1939_H
 #include <linux/can/j1939.h>
 #endif

configure.ac

@@ -3046,10 +3046,10 @@ AC_CHECK_HEADERS([linux/vm_sockets.h], [], [], [
 #endif
 ])
 
-# On Linux, can.h, can/bcm.h, can/j1939.h, can/raw.h require sys/socket.h
+# On Linux, can.h, can/bcm.h, can/isotp.h, can/j1939.h, can/raw.h require sys/socket.h
 # On NetBSD, netcan/can.h requires sys/socket.h
 AC_CHECK_HEADERS(
-[linux/can.h linux/can/bcm.h linux/can/j1939.h linux/can/raw.h netcan/can.h],
+[linux/can.h linux/can/bcm.h linux/can/isotp.h linux/can/j1939.h linux/can/raw.h netcan/can.h],
 [], [], [
 #ifdef HAVE_SYS_SOCKET_H
 #include <sys/socket.h>