Subject: Re: [PATCH iproute2] Allow to configure /var/run/netns directory

From: Stephen Hemminger <[email-masked]>
Date: Fri, 18 May 2018 14:53:06 -0700

On Tue, 15 May 2018 14:49:46 -0700
Pavel Maltsev <[email-masked]> wrote:

> Currently NETNS_RUN_DIR is hardcoded and refers to /var/run/netns.
> However, some systems (e.g. Android) doesn't have /var
> which results in error attempts to create network namespaces on these
> systems.  This change makes NETNS_RUN_DIR configurable at build time
> by allowing to pass environment variable to configre script.
> 
> For example: NETNS_RUN_DIR=/mnt/vendor/netns ./configure && make
> 
> Tested: verified that iproute2 with configuration mentioned above
> creates namespaces in /mnt/vendor/netns
> 
> Signed-off-by: Pavel Maltsev <[email-masked]>

The directory path should definitely be overrideable on the build.
The configure script is already messy enough, lets do it instead like
the other runtime directories are already done ARPDDIR and CONFDIR.

Something like?

diff --git a/Makefile b/Makefile
index b526d3b5b5c4..ab828669e711 100644
--- a/Makefile
+++ b/Makefile
@@ -16,6 +16,7 @@ PREFIX?=/usr
 LIBDIR?=$(PREFIX)/lib
 SBINDIR?=/sbin
 CONFDIR?=/etc/iproute2
+NETNS_RUN_DIR?=/var/run/netns
 DATADIR?=$(PREFIX)/share
 HDRDIR?=$(PREFIX)/include/iproute2
 DOCDIR?=$(DATADIR)/doc/iproute2
@@ -34,7 +35,7 @@ ifneq ($(SHARED_LIBS),y)
 DEFINES+= -DNO_SHARED_LIBS
 endif
 
-DEFINES+=-DCONFDIR=\"$(CONFDIR)\"
+DEFINES+=-DCONFDIR=\"$(CONFDIR)\" -DNETNS_RUN_DIR=\"$(NETNS_RUN_DIR)\"
 
 #options for decnet
 ADDLIB+=dnet_ntop.o dnet_pton.o
diff --git a/include/namespace.h b/include/namespace.h
index aed7ce08507f..e47f9b5d49d1 100644
--- a/include/namespace.h
+++ b/include/namespace.h
@@ -8,8 +8,13 @@
 #include <sys/syscall.h>
 #include <errno.h>
 
+#ifndef NETNS_RUN_DIR
 #define NETNS_RUN_DIR "/var/run/netns"
+#endif
+
+#ifndef NETNS_ETC_DIR
 #define NETNS_ETC_DIR "/etc/netns"
+#endif
 
 #ifndef CLONE_NEWNET
 #define CLONE_NEWNET 0x40000000	/* New network namespace (lo, device, names sockets, etc) */