From: Jay Vosburgh <jay.vosburgh@canonical.com>
To: Stephen Hemminger <stephen@networkplumber.org>
Cc: Max Gautier <mg@max.gautier.name>, netdev@vger.kernel.org
Subject: Re: [PATCH iproute2-next] arpd: create /var/lib/arpd on first use
Date: Sat, 16 Mar 2024 12:56:37 -0700 [thread overview]
Message-ID: <3016.1710618997@famine> (raw)
In-Reply-To: <20240316080702.4cb0ed9a@hermes.local>
Stephen Hemminger <stephen@networkplumber.org> wrote:
>On Sat, 16 Mar 2024 10:06:44 +0100
>Max Gautier <mg@max.gautier.name> wrote:
>
>> 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
>> ---
>> Instead of modifying the default location, I opted to create it at
>> runtime, but only for the default location and assuming that /var/lib
>> exists. My thinking is that not changing defaults is somewhat better,
>> plus using /var/tmp directly might cause security concerns (I don't know
>> that it does, but at least someone could create a db file which the root
>> user would then open by default. Not sure what that could cause, so I'd
>> rather avoid it).
>>
>> Makefile | 2 +-
>> misc/arpd.c | 12 +++++++++++-
>> 2 files changed, 12 insertions(+), 2 deletions(-)
>>
>> diff --git a/Makefile b/Makefile
>> index 8024d45e..2b2c3dec 100644
>> --- a/Makefile
>> +++ b/Makefile
>> @@ -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)
>> diff --git a/misc/arpd.c b/misc/arpd.c
>> index 1ef837c6..a133226c 100644
>> --- a/misc/arpd.c
>> +++ b/misc/arpd.c
>> @@ -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 * const default_dbname = ARPDDIR "/arpd.db";
>
>Make this an array.
>const char *default_dbname[] = ARPDDIR "/arpd.db";
I suspect this should be
const char default_dbname[] = ARPDDIR "/arpd.db";
i.e., no "*" before "default_dbname", to match the type of
dbname (below).
>> +char const *dbname = default_dbname;
>>
>> int ifnum;
>> int *ifvec;
>> @@ -668,6 +670,14 @@ int main(int argc, char **argv)
>> }
>> }
>>
>> + if (default_dbname == dbname
>> + && mkdir(ARPDDIR, 0755) != 0
>> + && errno != EEXIST
>> + ) {
>> + perror("create_db_dir");
>> + exit(-1);
>> + }
>> +
Should this be a string comparison? I don't think the pointer
comparison "default_dbname == dbname" will do what you expect if a user
specifies "-b" with the default value of ARPDIR "/arpd.db" as its
argument (i.e., the pointers won't match, but the actual text is the
same).
-J
>> dbase = dbopen(dbname, O_CREAT|O_RDWR, 0644, DB_HASH, NULL);
>> if (dbase == NULL) {
>> perror("db_open");
>
>Missing signed-off-by
>
---
-Jay Vosburgh, jay.vosburgh@canonical.com
next prev parent reply other threads:[~2024-03-16 20:03 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20240313093856.17fc459e@hermes.local>
2024-03-16 9:06 ` [PATCH iproute2-next] arpd: create /var/lib/arpd on first use Max Gautier
2024-03-16 15:07 ` Stephen Hemminger
2024-03-16 19:56 ` Jay Vosburgh [this message]
2024-03-17 0:14 ` Max Gautier
2024-03-17 9:01 ` [PATCH iproute2-next v2] " Max Gautier
2024-03-17 15:39 ` Stephen Hemminger
[not found] ` <09BB339D-A57C-4F67-BE67-2859F0262C86@126.com>
2024-03-17 17:23 ` Max Gautier
2024-03-18 2:56 ` Ratheesh Kannoth
2024-03-18 8:37 ` Max Gautier
2024-03-18 8:51 ` [EXTERNAL] " Ratheesh Kannoth
2024-03-18 8:59 ` Max Gautier
2024-03-18 9:18 ` Ratheesh Kannoth
2024-03-18 9:26 ` Max Gautier
2024-03-18 9:37 ` Denis Kirjanov
2024-03-18 9:43 ` Ratheesh Kannoth
2024-03-18 15:49 ` [PATCH iproute2-next v3] " Max Gautier
2024-03-28 20:40 ` patchwork-bot+netdevbpf
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