arpd: create /var/lib/arpd on first use

The motivation is to build distributions packages without /var to go
towards stateless systems, see link below (TL;DR: provisionning anything
outside of /usr on boot).

We only try do create the database directory when it's in the default
location, and assume its parent (/var/lib in the usual case) exists.

Links: https://0pointer.net/blog/projects/stateless.html
Signed-off-by: Max Gautier <mg@max.gautier.name>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
This commit is contained in:
Max Gautier 2024-03-18 16:49:13 +01:00 committed by Stephen Hemminger
parent 037a3a0d66
commit f740f5a165
2 changed files with 11 additions and 2 deletions

View File

@ -42,6 +42,7 @@ DEFINES+=-DCONF_USR_DIR=\"$(CONF_USR_DIR)\" \
-DCONF_ETC_DIR=\"$(CONF_ETC_DIR)\" \
-DNETNS_RUN_DIR=\"$(NETNS_RUN_DIR)\" \
-DNETNS_ETC_DIR=\"$(NETNS_ETC_DIR)\" \
-DARPDDIR=\"$(ARPDDIR)\" \
-DCONF_COLOR=$(CONF_COLOR)
#options for AX.25
@ -104,7 +105,6 @@ config.mk:
install: all
install -m 0755 -d $(DESTDIR)$(SBINDIR)
install -m 0755 -d $(DESTDIR)$(CONF_USR_DIR)
install -m 0755 -d $(DESTDIR)$(ARPDDIR)
install -m 0755 -d $(DESTDIR)$(HDRDIR)
@for i in $(SUBDIRS); do $(MAKE) -C $$i install; done
install -m 0644 $(shell find etc/iproute2 -maxdepth 1 -type f) $(DESTDIR)$(CONF_USR_DIR)

View File

@ -19,6 +19,7 @@
#include <fcntl.h>
#include <sys/uio.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <time.h>
#include <signal.h>
@ -35,7 +36,8 @@
#include "rt_names.h"
DB *dbase;
char *dbname = "/var/lib/arpd/arpd.db";
char const default_dbname[] = ARPDDIR "/arpd.db";
char const *dbname = default_dbname;
int ifnum;
int *ifvec;
@ -668,6 +670,13 @@ int main(int argc, char **argv)
}
}
if (strcmp(default_dbname, dbname) == 0) {
if (mkdir(ARPDDIR, 0755) != 0 && errno != EEXIST) {
perror("create_db_dir");
exit(-1);
}
}
dbase = dbopen(dbname, O_CREAT|O_RDWR, 0644, DB_HASH, NULL);
if (dbase == NULL) {
perror("db_open");