ipt_NETFLOW: add compatibility with 6.8+ (include 6.11)

[vvfedorenko]

Linux 6.8:

• add strlcpy definition as it was removed in 6.8
• replace strtoul with simple_strtoul which exists in all kernels and is proper interface to use
• inline timeval_to_jiffies to follow new kernel build rules
• replace check for in{4,6}_pton to remove unneeded functions
  Linux 6.11:
• constify sysctl proc handlers

[k0ste]

@aabc

[juju4]

as per #227, strlcopy can just be replaced by strscpy

[vvfedorenko]

as per #227, strlcopy can just be replaced by strscpy

Except that strscpy doesn't exist till linux 4.3. but you might be right, it's better to switch to safe modern implementation. I'll make it

[vvfedorenko]

@aabc could you please merge it?

[k0ste]

@juju4 this patch works for you? For me - still have issues

==> Starting build()...
./gen_compat_def > compat_def.h-
Test function xt_family linux/netfilter_ipv4/ip_tables.h  declared
Test struct timeval linux/ktime.h  undeclared
egrep: warning: egrep is obsolescent; using grep -E
Test struct proc_ops linux/proc_fs.h  declared
Test function synchronize_sched linux/rcupdate.h  undeclared
egrep: warning: egrep is obsolescent; using grep -E
Test function nf_bridge_info_get linux/netfilter_bridge.h  declared
Test struct vlan_dev_priv linux/if_vlan.h  declared
Test function put_unaligned_be24 asm/unaligned.h  declared
Test function totalram_pages linux/mm.h  declared
Test symbol totalram_pages linux/mm.h  declared
Test member nf_ct_event_notifier.ct_event net/netfilter/nf_conntrack_ecache.h  declared
Test function register_sysctl_paths linux/sysctl.h  undeclared
egrep: warning: egrep is obsolescent; using grep -E
Test function strscpy linux/string.h  undeclared
egrep: warning: egrep is obsolescent; using grep -E
Test function in6_pton linux/inet.h  declared
mv compat_def.h- compat_def.h
Compiling 2.6 for kernel 6.11.5-arch1-1-nfcustom
make -C /usr/lib/modules/6.11.5-arch1-1-nfcustom/build M=/srv/raid/filez/builder/PACKAGES/6.11.5/ipt_netflow/src/ipt-netflow-2.6 modules
make[1]: Entering directory '/usr/lib/modules/6.11.5-arch1-1-nfcustom/build'
  CC [M]  /srv/raid/filez/builder/PACKAGES/6.11.5/ipt_netflow/src/ipt-netflow-2.6/ipt_NETFLOW.o
In file included from /srv/raid/filez/builder/PACKAGES/6.11.5/ipt_netflow/src/ipt-netflow-2.6/ipt_NETFLOW.c:80:
/srv/raid/filez/builder/PACKAGES/6.11.5/ipt_netflow/src/ipt-netflow-2.6/compat.h:229:9: warning: "strscpy" redefined
  229 | #define strscpy strlcpy
      |         ^~~~~~~
In file included from ./include/linux/bitmap.h:13,
                 from ./include/linux/cpumask.h:12,
                 from ./arch/x86/include/asm/paravirt.h:21,
                 from ./arch/x86/include/asm/cpuid.h:62,
                 from ./arch/x86/include/asm/processor.h:19,
                 from ./arch/x86/include/asm/timex.h:5,
                 from ./include/linux/timex.h:67,
                 from ./include/linux/time32.h:13,
                 from ./include/linux/time.h:60,
                 from ./include/linux/stat.h:19,
                 from ./include/linux/module.h:13,
                 from /srv/raid/filez/builder/PACKAGES/6.11.5/ipt_netflow/src/ipt-netflow-2.6/ipt_NETFLOW.c:22:
./include/linux/string.h:108:9: note: this is the location of the previous definition
  108 | #define strscpy(dst, src, ...)  \
      |         ^~~~~~~
/srv/raid/filez/builder/PACKAGES/6.11.5/ipt_netflow/src/ipt-netflow-2.6/ipt_NETFLOW.c:1810:35: error: initialization of ‘int (*)(const struct ctl_table *, int,  void *, size_t *, loff_t *)’ {aka ‘int (*)(const struct ctl_table *, int,  void *, long unsigned int *, long long int *)’} from incompatible pointer type ‘int (*)(struct ctl_table *, int,  void *, size_t *, loff_t *)’ {aka ‘int (*)(struct ctl_table *, int,  void *, long unsigned int *, long long int *)’} [-Wincompatible-pointer-types]
 1810 |                 .proc_handler   = &hsize_procctl,
      |                                   ^
/srv/raid/filez/builder/PACKAGES/6.11.5/ipt_netflow/src/ipt-netflow-2.6/ipt_NETFLOW.c:1810:35: note: (near initialization for ‘netflow_sysctl_table[3].proc_handler’)
/srv/raid/filez/builder/PACKAGES/6.11.5/ipt_netflow/src/ipt-netflow-2.6/ipt_NETFLOW.c:1816:35: error: initialization of ‘int (*)(const struct ctl_table *, int,  void *, size_t *, loff_t *)’ {aka ‘int (*)(const struct ctl_table *, int,  void *, long unsigned int *, long long int *)’} from incompatible pointer type ‘int (*)(struct ctl_table *, int,  void *, size_t *, loff_t *)’ {aka ‘int (*)(struct ctl_table *, int,  void *, long unsigned int *, long long int *)’} [-Wincompatible-pointer-types]
 1816 |                 .proc_handler   = &sndbuf_procctl,
      |                                   ^
/srv/raid/filez/builder/PACKAGES/6.11.5/ipt_netflow/src/ipt-netflow-2.6/ipt_NETFLOW.c:1816:35: note: (near initialization for ‘netflow_sysctl_table[4].proc_handler’)
/srv/raid/filez/builder/PACKAGES/6.11.5/ipt_netflow/src/ipt-netflow-2.6/ipt_NETFLOW.c:1823:35: error: initialization of ‘int (*)(const struct ctl_table *, int,  void *, size_t *, loff_t *)’ {aka ‘int (*)(const struct ctl_table *, int,  void *, long unsigned int *, long long int *)’} from incompatible pointer type ‘int (*)(struct ctl_table *, int,  void *, size_t *, loff_t *)’ {aka ‘int (*)(struct ctl_table *, int,  void *, long unsigned int *, long long int *)’} [-Wincompatible-pointer-types]
 1823 |                 .proc_handler   = &destination_procctl,
      |                                   ^
/srv/raid/filez/builder/PACKAGES/6.11.5/ipt_netflow/src/ipt-netflow-2.6/ipt_NETFLOW.c:1823:35: note: (near initialization for ‘netflow_sysctl_table[5].proc_handler’)
/srv/raid/filez/builder/PACKAGES/6.11.5/ipt_netflow/src/ipt-netflow-2.6/ipt_NETFLOW.c:1845:35: error: initialization of ‘int (*)(const struct ctl_table *, int,  void *, size_t *, loff_t *)’ {aka ‘int (*)(const struct ctl_table *, int,  void *, long unsigned int *, long long int *)’} from incompatible pointer type ‘int (*)(struct ctl_table *, int,  void *, size_t *, loff_t *)’ {aka ‘int (*)(struct ctl_table *, int,  void *, long unsigned int *, long long int *)’} [-Wincompatible-pointer-types]
 1845 |                 .proc_handler   = &flush_procctl,
      |                                   ^
/srv/raid/filez/builder/PACKAGES/6.11.5/ipt_netflow/src/ipt-netflow-2.6/ipt_NETFLOW.c:1845:35: note: (near initialization for ‘netflow_sysctl_table[7].proc_handler’)
/srv/raid/filez/builder/PACKAGES/6.11.5/ipt_netflow/src/ipt-netflow-2.6/ipt_NETFLOW.c:1851:35: error: initialization of ‘int (*)(const struct ctl_table *, int,  void *, size_t *, loff_t *)’ {aka ‘int (*)(const struct ctl_table *, int,  void *, long unsigned int *, long long int *)’} from incompatible pointer type ‘int (*)(struct ctl_table *, int,  void *, size_t *, loff_t *)’ {aka ‘int (*)(struct ctl_table *, int,  void *, long unsigned int *, long long int *)’} [-Wincompatible-pointer-types]
 1851 |                 .proc_handler   = &protocol_procctl,
      |                                   ^
/srv/raid/filez/builder/PACKAGES/6.11.5/ipt_netflow/src/ipt-netflow-2.6/ipt_NETFLOW.c:1851:35: note: (near initialization for ‘netflow_sysctl_table[8].proc_handler’)
/srv/raid/filez/builder/PACKAGES/6.11.5/ipt_netflow/src/ipt-netflow-2.6/ipt_NETFLOW.c: In function ‘ethtool_drvinfo’:
/srv/raid/filez/builder/PACKAGES/6.11.5/ipt_netflow/src/ipt-netflow-2.6/compat.h:229:17: error: implicit declaration of function ‘strlcpy’; did you mean ‘strncpy’? [-Wimplicit-function-declaration]
  229 | #define strscpy strlcpy
      |                 ^~~~~~~
/srv/raid/filez/builder/PACKAGES/6.11.5/ipt_netflow/src/ipt-netflow-2.6/ipt_NETFLOW.c:4093:17: note: in expansion of macro ‘strscpy’
 4093 |                 strscpy(info.driver, dev->dev.parent->driver->name, sizeof(info.driver));
      |                 ^~~~~~~
make[3]: *** [scripts/Makefile.build:244: /srv/raid/filez/builder/PACKAGES/6.11.5/ipt_netflow/src/ipt-netflow-2.6/ipt_NETFLOW.o] Error 1
make[2]: *** [/usr/lib/modules/6.11.5-arch1-1-nfcustom/build/Makefile:1926: /srv/raid/filez/builder/PACKAGES/6.11.5/ipt_netflow/src/ipt-netflow-2.6] Error 2
make[1]: *** [Makefile:224: __sub-make] Error 2
make[1]: Leaving directory '/usr/lib/modules/6.11.5-arch1-1-nfcustom/build'
make: *** [Makefile:27: ipt_NETFLOW.ko] Error 2
==> ERROR: A failure occurred in build().
    Aborting...

[juju4]

@juju4 this patch works for you? For me - still have issues

I did not use the patch. only replaced strlcpy by strscpy which seems to work for ubuntu-24.04. no change needed for 22.04

[vvfedorenko]

Oops, strscpy is not a function, it's a MACRO starting from 6.9 while in 6.8 it was a function. Have to check it differently.

[k0ste]

Oops, strscpy is not a function, it's a MACRO starting from 6.9 while in 6.8 it was a function. Have to check it differently.

Added to Arch 🤳🏿

[anbe42]

An alternative solution for v6.12 support can be found in #233 that works for me for all kernel versions I tested (only tried Debian packaged ones).

[anbe42]

Testing kernel header existence at the file system level is very fragile and does not work for all kernel versions equally well.

Also e.g. the Debian linux-headers-* packages have split up the headers into /lib/modules/X.Y.Z-amd64/build -> /usr/src/linux-headers-X.Y.Z-amd64 and /lib/modules/X.Y.Z-amd64/source -> /usr/src/linux-headers-X.Y.Z-common
I tried checking in both locations, but that didn't work either for all kernel versions.

[anbe42]

This lacks support for < 3.17

--- a/compat.h
+++ b/compat.h
@@ -80,10 +80,16 @@ union nf_inet_addr {
 #  define s_ctl_table const struct ctl_table
 # elif LINUX_VERSION_CODE >= KERNEL_VERSION(3,17,0)
 #  define s_ctl_table struct ctl_table
+# else
+#  define s_ctl_table ctl_table
 # endif
 
-# if !defined(HAVE_GRSECURITY_H) && LINUX_VERSION_CODE >= KERNEL_VERSION(3,17,0)
-#  define ctl_table_no_const struct ctl_table
+# ifndef HAVE_GRSECURITY_H
+#  if LINUX_VERSION_CODE >= KERNEL_VERSION(3,17,0)
+#   define ctl_table_no_const struct ctl_table
+#  else
+#   define ctl_table_no_const ctl_table
+#  endif
 # endif
 #endif