Allow building with IPv6 disabled

[carneallabrace]

Motivation

I would like to use sysdig on my raspberry (ARMv8, 64bit kernel) which doesn't have IPv6 enabled.

What i basically did

git clone https://github.com/draios/sysdig # 0.1.72-4500-g4918c7bea
cd sysdig
mkdir build; cd build; cmake ..
make

Relevant output

root@raspberrypi:/usr/src/sysdig/build# make 
[  1%] Built target uthash
[  3%] Built target tbb
[  4%] Built target c-ares
[  5%] Built target openssl
[  7%] Built target zlib
[  8%] Built target curl
[ 10%] Built target jsoncpp
[ 12%] Built target valijson
[ 14%] Built target re2
[ 16%] Built target njson
[configure-kmod] Including /usr/src/sysdig/build/driver/src//configure/ACCESS_OK_2/Makefile.inc /usr/src/sysdig/build/driver/src//configure/DEVNODE_ARG1_CONST/Makefile.inc /usr/src/sysdig/build/driver/src//configure/CLASS_CREATE_1/Makefile.inc
[configure-kmod] Setting HAS_ACCESS_OK_2 flag
[configure-kmod] Build output for HAS_DEVNODE_ARG1_CONST:
[configure-kmod] make: Entering directory '/usr/src/sysdig/build/driver/src/configure/DEVNODE_ARG1_CONST' make -C /usr/src/linux-rpi-5.10.y M=/usr/src/sysdig/build/driver/src/configure/DEVNODE_ARG1_CONST modules make[1]: Entering directory '/usr/src/linux-rpi-5.10.y'   CC [M]  /usr/src/sysdig/build/driver/src/configure/DEVNODE_ARG1_CONST/test.o /usr/src/sysdig/build/driver/src/configure/DEVNODE_ARG1_CONST/test.c: In function 'devnode_dev_const_init': /usr/src/sysdig/build/driver/src/configure/DEVNODE_ARG1_CONST/test.c:26:48: error: initialization of 'char * (*)(struct device *, umode_t *)' {aka 'char * (*)(struct device *, short unsigned int *)'} from incompatible pointer type 'char * (*)(const struct device *, umode_t *)' {aka 'char * (*)(const struct device *, short unsigned int *)'} [-Werror=incompatible-pointer-types]    26 |         struct class g_ppm_class = {.devnode = ppm_devnode};       |                                                ^~~~~~~~~~~ /usr/src/sysdig/build/driver/src/configure/DEVNODE_ARG1_CONST/test.c:26:48: note: (near initialization for 'g_ppm_class.devnode') cc1: some warnings being treated as errors make[2]: *** [scripts/Makefile.build:280: /usr/src/sysdig/build/driver/src/configure/DEVNODE_ARG1_CONST/test.o] Error 1 make[1]: *** [Makefile:1825: /usr/src/sysdig/build/driver/src/configure/DEVNODE_ARG1_CONST] Error 2 make[1]: Leaving directory '/usr/src/linux-rpi-5.10.y' make: *** [Makefile:15: all] Error 2 make: Leaving directory '/usr/src/sysdig/build/driver/src/configure/DEVNODE_ARG1_CONST'
[configure-kmod] Build output for HAS_CLASS_CREATE_1:
[configure-kmod] make: Entering directory '/usr/src/sysdig/build/driver/src/configure/CLASS_CREATE_1' make -C /usr/src/linux-rpi-5.10.y M=/usr/src/sysdig/build/driver/src/configure/CLASS_CREATE_1 modules make[1]: Entering directory '/usr/src/linux-rpi-5.10.y'   CC [M]  /usr/src/sysdig/build/driver/src/configure/CLASS_CREATE_1/test.o /usr/src/sysdig/build/driver/src/configure/CLASS_CREATE_1/test.c: In function 'class_create_test_init': /usr/src/sysdig/build/driver/src/configure/CLASS_CREATE_1/test.c:23:56: error: macro "class_create" requires 2 arguments, but only 1 given    23 |         struct class *g_ppm_class = class_create("test");       |                                                        ^ In file included from ./include/linux/device.h:31,                  from /usr/src/sysdig/build/driver/src/configure/CLASS_CREATE_1/test.c:17: ./include/linux/device/class.h:259: note: macro "class_create" defined here   259 | #define class_create(owner, name)               \       |  /usr/src/sysdig/build/driver/src/configure/CLASS_CREATE_1/test.c:23:37: error: 'class_create' undeclared (first use in this function); did you mean 'class_compat'?    23 |         struct class *g_ppm_class = class_create("test");       |                                     ^~~~~~~~~~~~       |                                     class_compat /usr/src/sysdig/build/driver/src/configure/CLASS_CREATE_1/test.c:23:37: note: each undeclared identifier is reported only once for each function it appears in make[2]: *** [scripts/Makefile.build:280: /usr/src/sysdig/build/driver/src/configure/CLASS_CREATE_1/test.o] Error 1 make[1]: *** [Makefile:1825: /usr/src/sysdig/build/driver/src/configure/CLASS_CREATE_1] Error 2 make[1]: Leaving directory '/usr/src/linux-rpi-5.10.y' make: *** [Makefile:15: all] Error 2 make: Leaving directory '/usr/src/sysdig/build/driver/src/configure/CLASS_CREATE_1'
/usr/src/sysdig/build/driver/src/ppm_events.c: In function ‘sock_getname’:
/usr/src/sysdig/build/driver/src/ppm_events.c:217:66: error: ‘struct inet_sock’ has no member named ‘pinet6’
  217 |                 struct ipv6_pinfo *np = (struct ipv6_pinfo *)inet->pinet6;
      |                                                                  ^~
In file included from /usr/src/sysdig/build/driver/src/ppm_events.c:16:
./include/net/sock.h:380:45: error: ‘struct sock_common’ has no member named ‘skc_v6_daddr’; did you mean ‘skc_daddr’?
  380 | #define sk_v6_daddr             __sk_common.skc_v6_daddr
      |                                             ^~~~~~~~~~~~
/usr/src/sysdig/build/driver/src/ppm_events.c:222:46: note: in expansion of macro ‘sk_v6_daddr’
  222 |                         sin->sin6_addr = sk->sk_v6_daddr;
      |                                              ^~~~~~~~~~~
./include/net/sock.h:381:37: error: ‘struct sock_common’ has no member named ‘skc_v6_rcv_saddr’; did you mean ‘skc_rcv_saddr’?
  381 | #define sk_v6_rcv_saddr __sk_common.skc_v6_rcv_saddr
      |                                     ^~~~~~~~~~~~~~~~
/usr/src/sysdig/build/driver/src/ppm_events.c:224:46: note: in expansion of macro ‘sk_v6_rcv_saddr’
  224 |                         sin->sin6_addr = sk->sk_v6_rcv_saddr;
      |                                              ^~~~~~~~~~~~~~~
/usr/src/sysdig/build/driver/src/ppm_events.c: In function ‘fd_to_socktuple’:
/usr/src/sysdig/build/driver/src/ppm_events.c:1125:70: error: ‘struct sock_common’ has no member named ‘skc_v6_daddr’; did you mean ‘skc_daddr’?
 1125 |                                         sip6 = sock->sk->__sk_common.skc_v6_daddr.in6_u.u6_addr8;
      |                                                                      ^~~~~~~~~~~~
      |                                                                      skc_daddr
make[5]: *** [scripts/Makefile.build:280: /usr/src/sysdig/build/driver/src/ppm_events.o] Error 1
make[4]: *** [Makefile:1825: /usr/src/sysdig/build/driver/src] Error 2
make[3]: *** [Makefile:22: all] Error 2
make[2]: *** [driver/CMakeFiles/driver.dir/build.make:70: driver/CMakeFiles/driver] Error 2
make[1]: *** [CMakeFiles/Makefile2:769: driver/CMakeFiles/driver.dir/all] Error 2
make: *** [Makefile:156: all] Error 2
root@raspberrypi:/usr/src/sysdig/build# zgrep IPV6 /proc/config.gz 
# CONFIG_IPV6 is not set
root@raspberrypi:/usr/src/sysdig/build# 

I reported this here since the code affected seems to be in this repo.

Feature

It seems you guys have some sort of autotools-like (why?) configuration system in "driver/configure" so maybe you could add a new HAS_IPV6 (HAVE_IPV6?) "macro" and then use it to #ifdef all those pesky case AF_INET:

Alternatives

Rebuilding my kernel with IPv6 enabled.

Additional context

[carneallabrace]

Just to be clear the same problem can be reproduced on amd64/linux-6.12.7 with IPv6 disabled, it has nothing to do with building on a Raspberry.

OTOH building with IPV6 enabled works, even on the Raspberry:

root@raspberrypi:/usr/src/linux-rpi-5.10.y# grep IPV6=y .config
CONFIG_IPV6=y
CONFIG_NF_DEFRAG_IPV6=y
root@raspberrypi:/usr/src/linux-rpi-5.10.y# modinfo ../sysdig/build/driver/scap.ko
filename:       /usr/src/linux-rpi-5.10.y/../sysdig/build/driver/scap.ko
schema_version: 2.22.1
api_version:    8.0.3
build_commit:   4918c7beab536d4859f33900e8121aaed6b203e3
version:        7.3.0+driver
author:         the Falco authors
license:        Dual MIT/GPL
srcversion:     A413F6F811834BFEA4B787C
depends:        
name:           scap
vermagic:       5.10.110-v8 SMP preempt mod_unload modversions aarch64
parm:           g_buffer_bytes_dim:This is the dimension of a single per-CPU buffer in bytes. Please note: this buffer will be mapped twice in the process virtual memory, so pay attention to its size.
parm:           max_consumers:Maximum number of consumers that can simultaneously open the devices (uint)
parm:           verbose:Enable verbose logging (bool)
root@raspberrypi:/usr/src/linux-rpi-5.10.y#