* Re: [PATCHv3 iproute2] ip route: ignore ENOENT during save if RT_TABLE_MAIN is being dumped
2021-06-25 10:44 ` [PATCHv3 " Alexander Mikhalitsyn
@ 2021-06-27 21:54 ` Stephen Hemminger
2021-06-28 6:31 ` Alexander Mikhalitsyn
2021-06-29 15:51 ` [PATCHv4 " Alexander Mikhalitsyn
` (2 subsequent siblings)
3 siblings, 1 reply; 31+ messages in thread
From: Stephen Hemminger @ 2021-06-27 21:54 UTC (permalink / raw)
To: Alexander Mikhalitsyn
Cc: netdev, David Ahern, Andrei Vagin, Alexander Mikhalitsyn
On Fri, 25 Jun 2021 13:44:40 +0300
Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
> We started to use in-kernel filtering feature which allows to get only needed
> tables (see iproute_dump_filter()). From the kernel side it's implemented in
> net/ipv4/fib_frontend.c (inet_dump_fib), net/ipv6/ip6_fib.c (inet6_dump_fib).
> The problem here is that behaviour of "ip route save" was changed after
> c7e6371bc ("ip route: Add protocol, table id and device to dump request").
> If filters are used, then kernel returns ENOENT error if requested table is absent,
> but in newly created net namespace even RT_TABLE_MAIN table doesn't exist.
> It is really allocated, for instance, after issuing "ip l set lo up".
>
> Reproducer is fairly simple:
> $ unshare -n ip route save > dump
> Error: ipv4: FIB table does not exist.
> Dump terminated
>
> Expected result here is to get empty dump file (as it was before this change).
>
> v2: reworked, so, now it takes into account NLMSGERR_ATTR_MSG
> (see nl_dump_ext_ack_done() function). We want to suppress error messages
> in stderr about absent FIB table from kernel too.
>
> v3: reworked to make code clearer. Introduced rtnl_suppressed_errors(),
> rtnl_suppress_error() helpers. User may suppress up to 3 errors (may be
> easily extened by changing SUPPRESS_ERRORS_INIT macro).
>
> Fixes: c7e6371bc ("ip route: Add protocol, table id and device to dump request")
> Cc: David Ahern <dsahern@gmail.com>
> Cc: Stephen Hemminger <stephen@networkplumber.org>
> Cc: Andrei Vagin <avagin@gmail.com>
> Cc: Alexander Mikhalitsyn <alexander@mihalicyn.com>
> Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>
> ---
> include/libnetlink.h | 37 +++++++++++++++++++++++++++++++++++++
> ip/iproute.c | 7 ++++++-
> lib/libnetlink.c | 27 ++++++++++++++++++++++-----
> 3 files changed, 65 insertions(+), 6 deletions(-)
>
> diff --git a/include/libnetlink.h b/include/libnetlink.h
> index b9073a6a..c41f714a 100644
> --- a/include/libnetlink.h
> +++ b/include/libnetlink.h
> @@ -121,6 +121,43 @@ int rtnl_dump_filter_nc(struct rtnl_handle *rth,
> void *arg, __u16 nc_flags);
> #define rtnl_dump_filter(rth, filter, arg) \
> rtnl_dump_filter_nc(rth, filter, arg, 0)
> +int rtnl_dump_filter_suppress_rtnl_errmsg_nc(struct rtnl_handle *rth,
> + rtnl_filter_t filter,
> + void *arg1, __u16 nc_flags, const int *errnos);
> +#define rtnl_dump_filter_suppress_rtnl_errmsg(rth, filter, arg, errnos) \
> + rtnl_dump_filter_suppress_rtnl_errmsg_nc(rth, filter, arg, 0, errnos)
Sorry, this is getting really ugly.
It is almost as bad as looking at Windows source code with the extremely long
function names.
It would be better to refactor the already overload rtnl_dump_filter into sub
components and different parts could use the sub functions as needed.
> +#define SUPPRESS_ERRORS_INIT { 0, 0, 0, 0 }
Why do you need a special macro just use {} in those places.
> +static inline int rtnl_suppressed_error(const int *errnos, int err_no)
Inline is unnecessary here.
> +{
> + /* errnos is 0 terminated array or NULL */
> + while (errnos && *errnos) {
> + if (err_no == *errnos)
> + return 1;
> +
> + errnos++;
> + }
> +
> + return 0;
> +}
> +static inline void rtnl_suppress_error(int *errnos, int err_no)
Blank line between functions, Again no inline
> +{
> + /* last 0 is trailing for errnos array */
> + int max = sizeof((int[])SUPPRESS_ERRORS_INIT) /
> + sizeof(int) - 1;
> +
> + if (errnos == NULL)
> + return;
> +
> + for (int i = 0; i < max; i++) {
> + if (errnos[i] == err_no)
> + break;
> +
> + if (!errnos[i]) {
> + errnos[i] = err_no;
> + break;
> + }
> + }
> +}
> int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n,
> struct nlmsghdr **answer)
> __attribute__((warn_unused_result));
> diff --git a/ip/iproute.c b/ip/iproute.c
> index 5853f026..532ca724 100644
> --- a/ip/iproute.c
> +++ b/ip/iproute.c
> @@ -1734,6 +1734,7 @@ static int iproute_list_flush_or_save(int argc, char **argv, int action)
> char *od = NULL;
> unsigned int mark = 0;
> rtnl_filter_t filter_fn;
> + int suppress_rtnl_errnos[] = SUPPRESS_ERRORS_INIT;
>
> if (action == IPROUTE_SAVE) {
> if (save_route_prep())
> @@ -1939,7 +1940,11 @@ static int iproute_list_flush_or_save(int argc, char **argv, int action)
>
> new_json_obj(json);
>
> - if (rtnl_dump_filter(&rth, filter_fn, stdout) < 0) {
> + if (filter.tb == RT_TABLE_MAIN)
> + rtnl_suppress_error(suppress_rtnl_errnos, ENOENT);
> +
> + if (rtnl_dump_filter_suppress_rtnl_errmsg(&rth, filter_fn, stdout,
> + suppress_rtnl_errnos) < 0) {
> fprintf(stderr, "Dump terminated\n");
> return -2;
> }
> diff --git a/lib/libnetlink.c b/lib/libnetlink.c
> index c958aa57..5c5a19bb 100644
> --- a/lib/libnetlink.c
> +++ b/lib/libnetlink.c
> @@ -673,7 +673,7 @@ int rtnl_dump_request_n(struct rtnl_handle *rth, struct nlmsghdr *n)
> return sendmsg(rth->fd, &msg, 0);
> }
>
> -static int rtnl_dump_done(struct nlmsghdr *h)
> +static int rtnl_dump_done(struct nlmsghdr *h, const int *errnos)
> {
> int len = *(int *)NLMSG_DATA(h);
>
> @@ -683,11 +683,15 @@ static int rtnl_dump_done(struct nlmsghdr *h)
> }
>
> if (len < 0) {
> + errno = -len;
> +
> + if (rtnl_suppressed_error(errnos, errno))
> + return 0;
> +
> /* check for any messages returned from kernel */
> if (nl_dump_ext_ack_done(h, len))
> return len;
>
> - errno = -len;
> switch (errno) {
> case ENOENT:
> case EOPNOTSUPP:
> @@ -789,7 +793,8 @@ static int rtnl_recvmsg(int fd, struct msghdr *msg, char **answer)
> }
>
> static int rtnl_dump_filter_l(struct rtnl_handle *rth,
> - const struct rtnl_dump_filter_arg *arg)
> + const struct rtnl_dump_filter_arg *arg,
> + const int *errnos)
> {
> struct sockaddr_nl nladdr;
> struct iovec iov;
> @@ -834,7 +839,7 @@ static int rtnl_dump_filter_l(struct rtnl_handle *rth,
> dump_intr = 1;
>
> if (h->nlmsg_type == NLMSG_DONE) {
> - err = rtnl_dump_done(h);
> + err = rtnl_dump_done(h, errnos);
> if (err < 0) {
> free(buf);
> return -1;
> @@ -891,7 +896,19 @@ int rtnl_dump_filter_nc(struct rtnl_handle *rth,
> { .filter = NULL, .arg1 = NULL, .nc_flags = 0, },
> };
>
> - return rtnl_dump_filter_l(rth, a);
> + return rtnl_dump_filter_l(rth, a, NULL);
> +}
> +
> +int rtnl_dump_filter_suppress_rtnl_errmsg_nc(struct rtnl_handle *rth,
> + rtnl_filter_t filter,
> + void *arg1, __u16 nc_flags, const int *errnos)
> +{
> + const struct rtnl_dump_filter_arg a[2] = {
> + { .filter = filter, .arg1 = arg1, .nc_flags = nc_flags, },
> + { .filter = NULL, .arg1 = NULL, .nc_flags = 0, },
> + };
> +
> + return rtnl_dump_filter_l(rth, a, errnos);
> }
>
> static void rtnl_talk_error(struct nlmsghdr *h, struct nlmsgerr *err,
^ permalink raw reply [flat|nested] 31+ messages in thread* Re: [PATCHv3 iproute2] ip route: ignore ENOENT during save if RT_TABLE_MAIN is being dumped
2021-06-27 21:54 ` Stephen Hemminger
@ 2021-06-28 6:31 ` Alexander Mikhalitsyn
2021-06-28 17:17 ` Stephen Hemminger
0 siblings, 1 reply; 31+ messages in thread
From: Alexander Mikhalitsyn @ 2021-06-28 6:31 UTC (permalink / raw)
To: Stephen Hemminger
Cc: netdev, David Ahern, Andrei Vagin, Alexander Mikhalitsyn
On Sun, 27 Jun 2021 14:54:24 -0700
Stephen Hemminger <stephen@networkplumber.org> wrote:
> On Fri, 25 Jun 2021 13:44:40 +0300
> Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
>
> > We started to use in-kernel filtering feature which allows to get only needed
> > tables (see iproute_dump_filter()). From the kernel side it's implemented in
> > net/ipv4/fib_frontend.c (inet_dump_fib), net/ipv6/ip6_fib.c (inet6_dump_fib).
> > The problem here is that behaviour of "ip route save" was changed after
> > c7e6371bc ("ip route: Add protocol, table id and device to dump request").
> > If filters are used, then kernel returns ENOENT error if requested table is absent,
> > but in newly created net namespace even RT_TABLE_MAIN table doesn't exist.
> > It is really allocated, for instance, after issuing "ip l set lo up".
> >
> > Reproducer is fairly simple:
> > $ unshare -n ip route save > dump
> > Error: ipv4: FIB table does not exist.
> > Dump terminated
> >
> > Expected result here is to get empty dump file (as it was before this change).
> >
> > v2: reworked, so, now it takes into account NLMSGERR_ATTR_MSG
> > (see nl_dump_ext_ack_done() function). We want to suppress error messages
> > in stderr about absent FIB table from kernel too.
> >
> > v3: reworked to make code clearer. Introduced rtnl_suppressed_errors(),
> > rtnl_suppress_error() helpers. User may suppress up to 3 errors (may be
> > easily extened by changing SUPPRESS_ERRORS_INIT macro).
> >
> > Fixes: c7e6371bc ("ip route: Add protocol, table id and device to dump request")
> > Cc: David Ahern <dsahern@gmail.com>
> > Cc: Stephen Hemminger <stephen@networkplumber.org>
> > Cc: Andrei Vagin <avagin@gmail.com>
> > Cc: Alexander Mikhalitsyn <alexander@mihalicyn.com>
> > Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>
> > ---
> > include/libnetlink.h | 37 +++++++++++++++++++++++++++++++++++++
> > ip/iproute.c | 7 ++++++-
> > lib/libnetlink.c | 27 ++++++++++++++++++++++-----
> > 3 files changed, 65 insertions(+), 6 deletions(-)
> >
> > diff --git a/include/libnetlink.h b/include/libnetlink.h
> > index b9073a6a..c41f714a 100644
> > --- a/include/libnetlink.h
> > +++ b/include/libnetlink.h
> > @@ -121,6 +121,43 @@ int rtnl_dump_filter_nc(struct rtnl_handle *rth,
> > void *arg, __u16 nc_flags);
> > #define rtnl_dump_filter(rth, filter, arg) \
> > rtnl_dump_filter_nc(rth, filter, arg, 0)
> > +int rtnl_dump_filter_suppress_rtnl_errmsg_nc(struct rtnl_handle *rth,
> > + rtnl_filter_t filter,
> > + void *arg1, __u16 nc_flags, const int *errnos);
> > +#define rtnl_dump_filter_suppress_rtnl_errmsg(rth, filter, arg, errnos) \
> > + rtnl_dump_filter_suppress_rtnl_errmsg_nc(rth, filter, arg, 0, errnos)
>
> Sorry, this is getting really ugly.
Sorry, I apparently overdid it in refactoring ;)
>
> It is almost as bad as looking at Windows source code with the extremely long
> function names.
Sure, I will choose shorter names.
>
> It would be better to refactor the already overload rtnl_dump_filter into sub
> components and different parts could use the sub functions as needed.
>
> > +#define SUPPRESS_ERRORS_INIT { 0, 0, 0, 0 }
>
> Why do you need a special macro just use {} in those places.
It seems like I wrongly interpreted you words about "magic array of size 2"
>>The design would be clearer if there were two arguments rather than magic array of size 2.
If I understand you correctly, you wanted to say that it's not fully convenient to read and
see "magic" initializator { 0, 0, 0, 0 } or similar. (why four zeroes? why not 3 or 1?)
So, I've decided to make macro for this initializer like we have macros for linked lists
initializators in kernel, for instance. Another reason is that If someone need to skip more than
3 errors, he can change initializer size and helper function rtnl_suppress_error() will
take new size into account.
What I want to implement:
1. Possibility to skip several errors in rtnl_dump_filter
2. Not use malloc for allocation of "errors" array (because array is really small and
malloc needs free, so it's easier to make errors with memleak in the future)
3. I'm trying not to change original function rtnl_dump_filter() signature because
it's used in other places and that's a stable API.
4. We want to allow programmer to dynamically add skipped errors. It means that
user not specifying array of skipped errors directly like { ENOENT, ENOSUPP, 0 }, but
can write something like:
if (ignore_old_kernel_errors)
rtnl_suppress_error(errors, ENOSUPP)
if (some_another_reason)
rtnl_suppress_error(errors, ENOENT)
Maybe some of my points not valid for us and I can throw it?
Thank you for review! ;)
Alex.
>
>
> > +static inline int rtnl_suppressed_error(const int *errnos, int err_no)
>
> Inline is unnecessary here.
>
> > +{
> > + /* errnos is 0 terminated array or NULL */
> > + while (errnos && *errnos) {
> > + if (err_no == *errnos)
> > + return 1;
> > +
> > + errnos++;
> > + }
> > +
> > + return 0;
> > +}
> > +static inline void rtnl_suppress_error(int *errnos, int err_no)
> Blank line between functions, Again no inline
>
> > +{
> > + /* last 0 is trailing for errnos array */
> > + int max = sizeof((int[])SUPPRESS_ERRORS_INIT) /
> > + sizeof(int) - 1;
> > +
> > + if (errnos == NULL)
> > + return;
> > +
> > + for (int i = 0; i < max; i++) {
> > + if (errnos[i] == err_no)
> > + break;
> > +
> > + if (!errnos[i]) {
> > + errnos[i] = err_no;
> > + break;
> > + }
> > + }
> > +}
> > int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n,
> > struct nlmsghdr **answer)
> > __attribute__((warn_unused_result));
> > diff --git a/ip/iproute.c b/ip/iproute.c
> > index 5853f026..532ca724 100644
> > --- a/ip/iproute.c
> > +++ b/ip/iproute.c
> > @@ -1734,6 +1734,7 @@ static int iproute_list_flush_or_save(int argc, char **argv, int action)
> > char *od = NULL;
> > unsigned int mark = 0;
> > rtnl_filter_t filter_fn;
> > + int suppress_rtnl_errnos[] = SUPPRESS_ERRORS_INIT;
> >
> > if (action == IPROUTE_SAVE) {
> > if (save_route_prep())
> > @@ -1939,7 +1940,11 @@ static int iproute_list_flush_or_save(int argc, char **argv, int action)
> >
> > new_json_obj(json);
> >
> > - if (rtnl_dump_filter(&rth, filter_fn, stdout) < 0) {
> > + if (filter.tb == RT_TABLE_MAIN)
> > + rtnl_suppress_error(suppress_rtnl_errnos, ENOENT);
> > +
> > + if (rtnl_dump_filter_suppress_rtnl_errmsg(&rth, filter_fn, stdout,
> > + suppress_rtnl_errnos) < 0) {
> > fprintf(stderr, "Dump terminated\n");
> > return -2;
> > }
> > diff --git a/lib/libnetlink.c b/lib/libnetlink.c
> > index c958aa57..5c5a19bb 100644
> > --- a/lib/libnetlink.c
> > +++ b/lib/libnetlink.c
> > @@ -673,7 +673,7 @@ int rtnl_dump_request_n(struct rtnl_handle *rth, struct nlmsghdr *n)
> > return sendmsg(rth->fd, &msg, 0);
> > }
> >
> > -static int rtnl_dump_done(struct nlmsghdr *h)
> > +static int rtnl_dump_done(struct nlmsghdr *h, const int *errnos)
> > {
> > int len = *(int *)NLMSG_DATA(h);
> >
> > @@ -683,11 +683,15 @@ static int rtnl_dump_done(struct nlmsghdr *h)
> > }
> >
> > if (len < 0) {
> > + errno = -len;
> > +
> > + if (rtnl_suppressed_error(errnos, errno))
> > + return 0;
> > +
> > /* check for any messages returned from kernel */
> > if (nl_dump_ext_ack_done(h, len))
> > return len;
> >
> > - errno = -len;
> > switch (errno) {
> > case ENOENT:
> > case EOPNOTSUPP:
> > @@ -789,7 +793,8 @@ static int rtnl_recvmsg(int fd, struct msghdr *msg, char **answer)
> > }
> >
> > static int rtnl_dump_filter_l(struct rtnl_handle *rth,
> > - const struct rtnl_dump_filter_arg *arg)
> > + const struct rtnl_dump_filter_arg *arg,
> > + const int *errnos)
> > {
> > struct sockaddr_nl nladdr;
> > struct iovec iov;
> > @@ -834,7 +839,7 @@ static int rtnl_dump_filter_l(struct rtnl_handle *rth,
> > dump_intr = 1;
> >
> > if (h->nlmsg_type == NLMSG_DONE) {
> > - err = rtnl_dump_done(h);
> > + err = rtnl_dump_done(h, errnos);
> > if (err < 0) {
> > free(buf);
> > return -1;
> > @@ -891,7 +896,19 @@ int rtnl_dump_filter_nc(struct rtnl_handle *rth,
> > { .filter = NULL, .arg1 = NULL, .nc_flags = 0, },
> > };
> >
> > - return rtnl_dump_filter_l(rth, a);
> > + return rtnl_dump_filter_l(rth, a, NULL);
> > +}
> > +
> > +int rtnl_dump_filter_suppress_rtnl_errmsg_nc(struct rtnl_handle *rth,
> > + rtnl_filter_t filter,
> > + void *arg1, __u16 nc_flags, const int *errnos)
> > +{
> > + const struct rtnl_dump_filter_arg a[2] = {
> > + { .filter = filter, .arg1 = arg1, .nc_flags = nc_flags, },
> > + { .filter = NULL, .arg1 = NULL, .nc_flags = 0, },
> > + };
> > +
> > + return rtnl_dump_filter_l(rth, a, errnos);
> > }
> >
> > static void rtnl_talk_error(struct nlmsghdr *h, struct nlmsgerr *err,
>
^ permalink raw reply [flat|nested] 31+ messages in thread* Re: [PATCHv3 iproute2] ip route: ignore ENOENT during save if RT_TABLE_MAIN is being dumped
2021-06-28 6:31 ` Alexander Mikhalitsyn
@ 2021-06-28 17:17 ` Stephen Hemminger
2021-06-28 17:21 ` Alexander Mikhalitsyn
0 siblings, 1 reply; 31+ messages in thread
From: Stephen Hemminger @ 2021-06-28 17:17 UTC (permalink / raw)
To: Alexander Mikhalitsyn
Cc: netdev, David Ahern, Andrei Vagin, Alexander Mikhalitsyn
On Mon, 28 Jun 2021 09:31:32 +0300
Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
> On Sun, 27 Jun 2021 14:54:24 -0700
> Stephen Hemminger <stephen@networkplumber.org> wrote:
>
> > On Fri, 25 Jun 2021 13:44:40 +0300
> > Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
> >
> > > We started to use in-kernel filtering feature which allows to get only needed
> > > tables (see iproute_dump_filter()). From the kernel side it's implemented in
> > > net/ipv4/fib_frontend.c (inet_dump_fib), net/ipv6/ip6_fib.c (inet6_dump_fib).
> > > The problem here is that behaviour of "ip route save" was changed after
> > > c7e6371bc ("ip route: Add protocol, table id and device to dump request").
> > > If filters are used, then kernel returns ENOENT error if requested table is absent,
> > > but in newly created net namespace even RT_TABLE_MAIN table doesn't exist.
> > > It is really allocated, for instance, after issuing "ip l set lo up".
> > >
> > > Reproducer is fairly simple:
> > > $ unshare -n ip route save > dump
> > > Error: ipv4: FIB table does not exist.
> > > Dump terminated
> > >
> > > Expected result here is to get empty dump file (as it was before this change).
> > >
> > > v2: reworked, so, now it takes into account NLMSGERR_ATTR_MSG
> > > (see nl_dump_ext_ack_done() function). We want to suppress error messages
> > > in stderr about absent FIB table from kernel too.
> > >
> > > v3: reworked to make code clearer. Introduced rtnl_suppressed_errors(),
> > > rtnl_suppress_error() helpers. User may suppress up to 3 errors (may be
> > > easily extened by changing SUPPRESS_ERRORS_INIT macro).
> > >
> > > Fixes: c7e6371bc ("ip route: Add protocol, table id and device to dump request")
> > > Cc: David Ahern <dsahern@gmail.com>
> > > Cc: Stephen Hemminger <stephen@networkplumber.org>
> > > Cc: Andrei Vagin <avagin@gmail.com>
> > > Cc: Alexander Mikhalitsyn <alexander@mihalicyn.com>
> > > Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>
> > > ---
> > > include/libnetlink.h | 37 +++++++++++++++++++++++++++++++++++++
> > > ip/iproute.c | 7 ++++++-
> > > lib/libnetlink.c | 27 ++++++++++++++++++++++-----
> > > 3 files changed, 65 insertions(+), 6 deletions(-)
> > >
> > > diff --git a/include/libnetlink.h b/include/libnetlink.h
> > > index b9073a6a..c41f714a 100644
> > > --- a/include/libnetlink.h
> > > +++ b/include/libnetlink.h
> > > @@ -121,6 +121,43 @@ int rtnl_dump_filter_nc(struct rtnl_handle *rth,
> > > void *arg, __u16 nc_flags);
> > > #define rtnl_dump_filter(rth, filter, arg) \
> > > rtnl_dump_filter_nc(rth, filter, arg, 0)
> > > +int rtnl_dump_filter_suppress_rtnl_errmsg_nc(struct rtnl_handle *rth,
> > > + rtnl_filter_t filter,
> > > + void *arg1, __u16 nc_flags, const int *errnos);
> > > +#define rtnl_dump_filter_suppress_rtnl_errmsg(rth, filter, arg, errnos) \
> > > + rtnl_dump_filter_suppress_rtnl_errmsg_nc(rth, filter, arg, 0, errnos)
> >
> > Sorry, this is getting really ugly.
>
> Sorry, I apparently overdid it in refactoring ;)
>
> >
> > It is almost as bad as looking at Windows source code with the extremely long
> > function names.
>
> Sure, I will choose shorter names.
>
> >
> > It would be better to refactor the already overload rtnl_dump_filter into sub
> > components and different parts could use the sub functions as needed.
> >
> > > +#define SUPPRESS_ERRORS_INIT { 0, 0, 0, 0 }
> >
> > Why do you need a special macro just use {} in those places.
>
> It seems like I wrongly interpreted you words about "magic array of size 2"
> >>The design would be clearer if there were two arguments rather than magic array of size 2.
> If I understand you correctly, you wanted to say that it's not fully convenient to read and
> see "magic" initializator { 0, 0, 0, 0 } or similar. (why four zeroes? why not 3 or 1?)
> So, I've decided to make macro for this initializer like we have macros for linked lists
> initializators in kernel, for instance. Another reason is that If someone need to skip more than
> 3 errors, he can change initializer size and helper function rtnl_suppress_error() will
> take new size into account.
>
> What I want to implement:
> 1. Possibility to skip several errors in rtnl_dump_filter
> 2. Not use malloc for allocation of "errors" array (because array is really small and
> malloc needs free, so it's easier to make errors with memleak in the future)
> 3. I'm trying not to change original function rtnl_dump_filter() signature because
> it's used in other places and that's a stable API.
> 4. We want to allow programmer to dynamically add skipped errors. It means that
> user not specifying array of skipped errors directly like { ENOENT, ENOSUPP, 0 }, but
> can write something like:
> if (ignore_old_kernel_errors)
> rtnl_suppress_error(errors, ENOSUPP)
> if (some_another_reason)
> rtnl_suppress_error(errors, ENOENT)
>
>
> Maybe some of my points not valid for us and I can throw it?
>
> Thank you for review! ;)
>
> Alex.
>
> >
> >
> > > +static inline int rtnl_suppressed_error(const int *errnos, int err_no)
> >
> > Inline is unnecessary here.
> >
> > > +{
> > > + /* errnos is 0 terminated array or NULL */
> > > + while (errnos && *errnos) {
> > > + if (err_no == *errnos)
> > > + return 1;
> > > +
> > > + errnos++;
> > > + }
> > > +
> > > + return 0;
> > > +}
> > > +static inline void rtnl_suppress_error(int *errnos, int err_no)
> > Blank line between functions, Again no inline
> >
> > > +{
> > > + /* last 0 is trailing for errnos array */
> > > + int max = sizeof((int[])SUPPRESS_ERRORS_INIT) /
> > > + sizeof(int) - 1;
> > > +
> > > + if (errnos == NULL)
> > > + return;
> > > +
> > > + for (int i = 0; i < max; i++) {
> > > + if (errnos[i] == err_no)
> > > + break;
> > > +
> > > + if (!errnos[i]) {
> > > + errnos[i] = err_no;
> > > + break;
> > > + }
> > > + }
> > > +}
> > > int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n,
> > > struct nlmsghdr **answer)
> > > __attribute__((warn_unused_result));
> > > diff --git a/ip/iproute.c b/ip/iproute.c
> > > index 5853f026..532ca724 100644
> > > --- a/ip/iproute.c
> > > +++ b/ip/iproute.c
> > > @@ -1734,6 +1734,7 @@ static int iproute_list_flush_or_save(int argc, char **argv, int action)
> > > char *od = NULL;
> > > unsigned int mark = 0;
> > > rtnl_filter_t filter_fn;
> > > + int suppress_rtnl_errnos[] = SUPPRESS_ERRORS_INIT;
> > >
> > > if (action == IPROUTE_SAVE) {
> > > if (save_route_prep())
> > > @@ -1939,7 +1940,11 @@ static int iproute_list_flush_or_save(int argc, char **argv, int action)
> > >
> > > new_json_obj(json);
> > >
> > > - if (rtnl_dump_filter(&rth, filter_fn, stdout) < 0) {
> > > + if (filter.tb == RT_TABLE_MAIN)
> > > + rtnl_suppress_error(suppress_rtnl_errnos, ENOENT);
> > > +
> > > + if (rtnl_dump_filter_suppress_rtnl_errmsg(&rth, filter_fn, stdout,
> > > + suppress_rtnl_errnos) < 0) {
> > > fprintf(stderr, "Dump terminated\n");
> > > return -2;
> > > }
> > > diff --git a/lib/libnetlink.c b/lib/libnetlink.c
> > > index c958aa57..5c5a19bb 100644
> > > --- a/lib/libnetlink.c
> > > +++ b/lib/libnetlink.c
> > > @@ -673,7 +673,7 @@ int rtnl_dump_request_n(struct rtnl_handle *rth, struct nlmsghdr *n)
> > > return sendmsg(rth->fd, &msg, 0);
> > > }
> > >
> > > -static int rtnl_dump_done(struct nlmsghdr *h)
> > > +static int rtnl_dump_done(struct nlmsghdr *h, const int *errnos)
> > > {
> > > int len = *(int *)NLMSG_DATA(h);
> > >
> > > @@ -683,11 +683,15 @@ static int rtnl_dump_done(struct nlmsghdr *h)
> > > }
> > >
> > > if (len < 0) {
> > > + errno = -len;
> > > +
> > > + if (rtnl_suppressed_error(errnos, errno))
> > > + return 0;
> > > +
> > > /* check for any messages returned from kernel */
> > > if (nl_dump_ext_ack_done(h, len))
> > > return len;
> > >
> > > - errno = -len;
> > > switch (errno) {
> > > case ENOENT:
> > > case EOPNOTSUPP:
> > > @@ -789,7 +793,8 @@ static int rtnl_recvmsg(int fd, struct msghdr *msg, char **answer)
> > > }
> > >
> > > static int rtnl_dump_filter_l(struct rtnl_handle *rth,
> > > - const struct rtnl_dump_filter_arg *arg)
> > > + const struct rtnl_dump_filter_arg *arg,
> > > + const int *errnos)
> > > {
> > > struct sockaddr_nl nladdr;
> > > struct iovec iov;
> > > @@ -834,7 +839,7 @@ static int rtnl_dump_filter_l(struct rtnl_handle *rth,
> > > dump_intr = 1;
> > >
> > > if (h->nlmsg_type == NLMSG_DONE) {
> > > - err = rtnl_dump_done(h);
> > > + err = rtnl_dump_done(h, errnos);
> > > if (err < 0) {
> > > free(buf);
> > > return -1;
> > > @@ -891,7 +896,19 @@ int rtnl_dump_filter_nc(struct rtnl_handle *rth,
> > > { .filter = NULL, .arg1 = NULL, .nc_flags = 0, },
> > > };
> > >
> > > - return rtnl_dump_filter_l(rth, a);
> > > + return rtnl_dump_filter_l(rth, a, NULL);
> > > +}
> > > +
> > > +int rtnl_dump_filter_suppress_rtnl_errmsg_nc(struct rtnl_handle *rth,
> > > + rtnl_filter_t filter,
> > > + void *arg1, __u16 nc_flags, const int *errnos)
> > > +{
> > > + const struct rtnl_dump_filter_arg a[2] = {
> > > + { .filter = filter, .arg1 = arg1, .nc_flags = nc_flags, },
> > > + { .filter = NULL, .arg1 = NULL, .nc_flags = 0, },
> > > + };
> > > +
> > > + return rtnl_dump_filter_l(rth, a, errnos);
> > > }
> > >
> > > static void rtnl_talk_error(struct nlmsghdr *h, struct nlmsgerr *err,
> >
Maybe adding an error handler callback to existing dump filter routine.
And add a rtnl_dump_error() function as the default error handler. (ie if NULL is passed)
That way your callback could skip what ever errors it wants and call the rtnl_dump_error
routine for the ones it wants to handle.
^ permalink raw reply [flat|nested] 31+ messages in thread* Re: [PATCHv3 iproute2] ip route: ignore ENOENT during save if RT_TABLE_MAIN is being dumped
2021-06-28 17:17 ` Stephen Hemminger
@ 2021-06-28 17:21 ` Alexander Mikhalitsyn
0 siblings, 0 replies; 31+ messages in thread
From: Alexander Mikhalitsyn @ 2021-06-28 17:21 UTC (permalink / raw)
To: Stephen Hemminger
Cc: netdev, David Ahern, Andrei Vagin, Alexander Mikhalitsyn
On Mon, 28 Jun 2021 10:17:45 -0700
Stephen Hemminger <stephen@networkplumber.org> wrote:
> On Mon, 28 Jun 2021 09:31:32 +0300
> Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
>
> > On Sun, 27 Jun 2021 14:54:24 -0700
> > Stephen Hemminger <stephen@networkplumber.org> wrote:
> >
> > > On Fri, 25 Jun 2021 13:44:40 +0300
> > > Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
> > >
> > > > We started to use in-kernel filtering feature which allows to get only needed
> > > > tables (see iproute_dump_filter()). From the kernel side it's implemented in
> > > > net/ipv4/fib_frontend.c (inet_dump_fib), net/ipv6/ip6_fib.c (inet6_dump_fib).
> > > > The problem here is that behaviour of "ip route save" was changed after
> > > > c7e6371bc ("ip route: Add protocol, table id and device to dump request").
> > > > If filters are used, then kernel returns ENOENT error if requested table is absent,
> > > > but in newly created net namespace even RT_TABLE_MAIN table doesn't exist.
> > > > It is really allocated, for instance, after issuing "ip l set lo up".
> > > >
> > > > Reproducer is fairly simple:
> > > > $ unshare -n ip route save > dump
> > > > Error: ipv4: FIB table does not exist.
> > > > Dump terminated
> > > >
> > > > Expected result here is to get empty dump file (as it was before this change).
> > > >
> > > > v2: reworked, so, now it takes into account NLMSGERR_ATTR_MSG
> > > > (see nl_dump_ext_ack_done() function). We want to suppress error messages
> > > > in stderr about absent FIB table from kernel too.
> > > >
> > > > v3: reworked to make code clearer. Introduced rtnl_suppressed_errors(),
> > > > rtnl_suppress_error() helpers. User may suppress up to 3 errors (may be
> > > > easily extened by changing SUPPRESS_ERRORS_INIT macro).
> > > >
> > > > Fixes: c7e6371bc ("ip route: Add protocol, table id and device to dump request")
> > > > Cc: David Ahern <dsahern@gmail.com>
> > > > Cc: Stephen Hemminger <stephen@networkplumber.org>
> > > > Cc: Andrei Vagin <avagin@gmail.com>
> > > > Cc: Alexander Mikhalitsyn <alexander@mihalicyn.com>
> > > > Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>
> > > > ---
> > > > include/libnetlink.h | 37 +++++++++++++++++++++++++++++++++++++
> > > > ip/iproute.c | 7 ++++++-
> > > > lib/libnetlink.c | 27 ++++++++++++++++++++++-----
> > > > 3 files changed, 65 insertions(+), 6 deletions(-)
> > > >
> > > > diff --git a/include/libnetlink.h b/include/libnetlink.h
> > > > index b9073a6a..c41f714a 100644
> > > > --- a/include/libnetlink.h
> > > > +++ b/include/libnetlink.h
> > > > @@ -121,6 +121,43 @@ int rtnl_dump_filter_nc(struct rtnl_handle *rth,
> > > > void *arg, __u16 nc_flags);
> > > > #define rtnl_dump_filter(rth, filter, arg) \
> > > > rtnl_dump_filter_nc(rth, filter, arg, 0)
> > > > +int rtnl_dump_filter_suppress_rtnl_errmsg_nc(struct rtnl_handle *rth,
> > > > + rtnl_filter_t filter,
> > > > + void *arg1, __u16 nc_flags, const int *errnos);
> > > > +#define rtnl_dump_filter_suppress_rtnl_errmsg(rth, filter, arg, errnos) \
> > > > + rtnl_dump_filter_suppress_rtnl_errmsg_nc(rth, filter, arg, 0, errnos)
> > >
> > > Sorry, this is getting really ugly.
> >
> > Sorry, I apparently overdid it in refactoring ;)
> >
> > >
> > > It is almost as bad as looking at Windows source code with the extremely long
> > > function names.
> >
> > Sure, I will choose shorter names.
> >
> > >
> > > It would be better to refactor the already overload rtnl_dump_filter into sub
> > > components and different parts could use the sub functions as needed.
> > >
> > > > +#define SUPPRESS_ERRORS_INIT { 0, 0, 0, 0 }
> > >
> > > Why do you need a special macro just use {} in those places.
> >
> > It seems like I wrongly interpreted you words about "magic array of size 2"
> > >>The design would be clearer if there were two arguments rather than magic array of size 2.
> > If I understand you correctly, you wanted to say that it's not fully convenient to read and
> > see "magic" initializator { 0, 0, 0, 0 } or similar. (why four zeroes? why not 3 or 1?)
> > So, I've decided to make macro for this initializer like we have macros for linked lists
> > initializators in kernel, for instance. Another reason is that If someone need to skip more than
> > 3 errors, he can change initializer size and helper function rtnl_suppress_error() will
> > take new size into account.
> >
> > What I want to implement:
> > 1. Possibility to skip several errors in rtnl_dump_filter
> > 2. Not use malloc for allocation of "errors" array (because array is really small and
> > malloc needs free, so it's easier to make errors with memleak in the future)
> > 3. I'm trying not to change original function rtnl_dump_filter() signature because
> > it's used in other places and that's a stable API.
> > 4. We want to allow programmer to dynamically add skipped errors. It means that
> > user not specifying array of skipped errors directly like { ENOENT, ENOSUPP, 0 }, but
> > can write something like:
> > if (ignore_old_kernel_errors)
> > rtnl_suppress_error(errors, ENOSUPP)
> > if (some_another_reason)
> > rtnl_suppress_error(errors, ENOENT)
> >
> >
> > Maybe some of my points not valid for us and I can throw it?
> >
> > Thank you for review! ;)
> >
> > Alex.
> >
> > >
> > >
> > > > +static inline int rtnl_suppressed_error(const int *errnos, int err_no)
> > >
> > > Inline is unnecessary here.
> > >
> > > > +{
> > > > + /* errnos is 0 terminated array or NULL */
> > > > + while (errnos && *errnos) {
> > > > + if (err_no == *errnos)
> > > > + return 1;
> > > > +
> > > > + errnos++;
> > > > + }
> > > > +
> > > > + return 0;
> > > > +}
> > > > +static inline void rtnl_suppress_error(int *errnos, int err_no)
> > > Blank line between functions, Again no inline
> > >
> > > > +{
> > > > + /* last 0 is trailing for errnos array */
> > > > + int max = sizeof((int[])SUPPRESS_ERRORS_INIT) /
> > > > + sizeof(int) - 1;
> > > > +
> > > > + if (errnos == NULL)
> > > > + return;
> > > > +
> > > > + for (int i = 0; i < max; i++) {
> > > > + if (errnos[i] == err_no)
> > > > + break;
> > > > +
> > > > + if (!errnos[i]) {
> > > > + errnos[i] = err_no;
> > > > + break;
> > > > + }
> > > > + }
> > > > +}
> > > > int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n,
> > > > struct nlmsghdr **answer)
> > > > __attribute__((warn_unused_result));
> > > > diff --git a/ip/iproute.c b/ip/iproute.c
> > > > index 5853f026..532ca724 100644
> > > > --- a/ip/iproute.c
> > > > +++ b/ip/iproute.c
> > > > @@ -1734,6 +1734,7 @@ static int iproute_list_flush_or_save(int argc, char **argv, int action)
> > > > char *od = NULL;
> > > > unsigned int mark = 0;
> > > > rtnl_filter_t filter_fn;
> > > > + int suppress_rtnl_errnos[] = SUPPRESS_ERRORS_INIT;
> > > >
> > > > if (action == IPROUTE_SAVE) {
> > > > if (save_route_prep())
> > > > @@ -1939,7 +1940,11 @@ static int iproute_list_flush_or_save(int argc, char **argv, int action)
> > > >
> > > > new_json_obj(json);
> > > >
> > > > - if (rtnl_dump_filter(&rth, filter_fn, stdout) < 0) {
> > > > + if (filter.tb == RT_TABLE_MAIN)
> > > > + rtnl_suppress_error(suppress_rtnl_errnos, ENOENT);
> > > > +
> > > > + if (rtnl_dump_filter_suppress_rtnl_errmsg(&rth, filter_fn, stdout,
> > > > + suppress_rtnl_errnos) < 0) {
> > > > fprintf(stderr, "Dump terminated\n");
> > > > return -2;
> > > > }
> > > > diff --git a/lib/libnetlink.c b/lib/libnetlink.c
> > > > index c958aa57..5c5a19bb 100644
> > > > --- a/lib/libnetlink.c
> > > > +++ b/lib/libnetlink.c
> > > > @@ -673,7 +673,7 @@ int rtnl_dump_request_n(struct rtnl_handle *rth, struct nlmsghdr *n)
> > > > return sendmsg(rth->fd, &msg, 0);
> > > > }
> > > >
> > > > -static int rtnl_dump_done(struct nlmsghdr *h)
> > > > +static int rtnl_dump_done(struct nlmsghdr *h, const int *errnos)
> > > > {
> > > > int len = *(int *)NLMSG_DATA(h);
> > > >
> > > > @@ -683,11 +683,15 @@ static int rtnl_dump_done(struct nlmsghdr *h)
> > > > }
> > > >
> > > > if (len < 0) {
> > > > + errno = -len;
> > > > +
> > > > + if (rtnl_suppressed_error(errnos, errno))
> > > > + return 0;
> > > > +
> > > > /* check for any messages returned from kernel */
> > > > if (nl_dump_ext_ack_done(h, len))
> > > > return len;
> > > >
> > > > - errno = -len;
> > > > switch (errno) {
> > > > case ENOENT:
> > > > case EOPNOTSUPP:
> > > > @@ -789,7 +793,8 @@ static int rtnl_recvmsg(int fd, struct msghdr *msg, char **answer)
> > > > }
> > > >
> > > > static int rtnl_dump_filter_l(struct rtnl_handle *rth,
> > > > - const struct rtnl_dump_filter_arg *arg)
> > > > + const struct rtnl_dump_filter_arg *arg,
> > > > + const int *errnos)
> > > > {
> > > > struct sockaddr_nl nladdr;
> > > > struct iovec iov;
> > > > @@ -834,7 +839,7 @@ static int rtnl_dump_filter_l(struct rtnl_handle *rth,
> > > > dump_intr = 1;
> > > >
> > > > if (h->nlmsg_type == NLMSG_DONE) {
> > > > - err = rtnl_dump_done(h);
> > > > + err = rtnl_dump_done(h, errnos);
> > > > if (err < 0) {
> > > > free(buf);
> > > > return -1;
> > > > @@ -891,7 +896,19 @@ int rtnl_dump_filter_nc(struct rtnl_handle *rth,
> > > > { .filter = NULL, .arg1 = NULL, .nc_flags = 0, },
> > > > };
> > > >
> > > > - return rtnl_dump_filter_l(rth, a);
> > > > + return rtnl_dump_filter_l(rth, a, NULL);
> > > > +}
> > > > +
> > > > +int rtnl_dump_filter_suppress_rtnl_errmsg_nc(struct rtnl_handle *rth,
> > > > + rtnl_filter_t filter,
> > > > + void *arg1, __u16 nc_flags, const int *errnos)
> > > > +{
> > > > + const struct rtnl_dump_filter_arg a[2] = {
> > > > + { .filter = filter, .arg1 = arg1, .nc_flags = nc_flags, },
> > > > + { .filter = NULL, .arg1 = NULL, .nc_flags = 0, },
> > > > + };
> > > > +
> > > > + return rtnl_dump_filter_l(rth, a, errnos);
> > > > }
> > > >
> > > > static void rtnl_talk_error(struct nlmsghdr *h, struct nlmsgerr *err,
> > >
>
> Maybe adding an error handler callback to existing dump filter routine.
> And add a rtnl_dump_error() function as the default error handler. (ie if NULL is passed)
> That way your callback could skip what ever errors it wants and call the rtnl_dump_error
> routine for the ones it wants to handle.
>
Great. I'll implement that! ;)
Thanks,
Alex
^ permalink raw reply [flat|nested] 31+ messages in thread
* [PATCHv4 iproute2] ip route: ignore ENOENT during save if RT_TABLE_MAIN is being dumped
2021-06-25 10:44 ` [PATCHv3 " Alexander Mikhalitsyn
2021-06-27 21:54 ` Stephen Hemminger
@ 2021-06-29 15:51 ` Alexander Mikhalitsyn
2021-07-06 7:47 ` Alexander Mikhalitsyn
2021-07-06 15:34 ` Stephen Hemminger
2021-07-07 12:09 ` [PATCHv5 " Alexander Mikhalitsyn
2021-07-07 12:22 ` Alexander Mikhalitsyn
3 siblings, 2 replies; 31+ messages in thread
From: Alexander Mikhalitsyn @ 2021-06-29 15:51 UTC (permalink / raw)
To: netdev
Cc: Alexander Mikhalitsyn, David Ahern, Stephen Hemminger,
Andrei Vagin, Alexander Mikhalitsyn
We started to use in-kernel filtering feature which allows to get only needed
tables (see iproute_dump_filter()). From the kernel side it's implemented in
net/ipv4/fib_frontend.c (inet_dump_fib), net/ipv6/ip6_fib.c (inet6_dump_fib).
The problem here is that behaviour of "ip route save" was changed after
c7e6371bc ("ip route: Add protocol, table id and device to dump request").
If filters are used, then kernel returns ENOENT error if requested table is absent,
but in newly created net namespace even RT_TABLE_MAIN table doesn't exist.
It is really allocated, for instance, after issuing "ip l set lo up".
Reproducer is fairly simple:
$ unshare -n ip route save > dump
Error: ipv4: FIB table does not exist.
Dump terminated
Expected result here is to get empty dump file (as it was before this change).
v2: reworked, so, now it takes into account NLMSGERR_ATTR_MSG
(see nl_dump_ext_ack_done() function). We want to suppress error messages
in stderr about absent FIB table from kernel too.
v3: reworked to make code clearer. Introduced rtnl_suppressed_errors(),
rtnl_suppress_error() helpers. User may suppress up to 3 errors (may be
easily extened by changing SUPPRESS_ERRORS_INIT macro).
v4: reworked, rtnl_dump_filter_errhndlr() was introduced. Thanks
to Stephen Hemminger for comments and suggestions
Fixes: c7e6371bc ("ip route: Add protocol, table id and device to dump request")
Cc: David Ahern <dsahern@gmail.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Alexander Mikhalitsyn <alexander@mihalicyn.com>
Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>
---
include/libnetlink.h | 32 +++++++++++++++++++++++++
ip/iproute.c | 15 +++++++++++-
lib/libnetlink.c | 56 +++++++++++++++++++++++++++++++++++---------
3 files changed, 91 insertions(+), 12 deletions(-)
diff --git a/include/libnetlink.h b/include/libnetlink.h
index b9073a6a..4545e5e5 100644
--- a/include/libnetlink.h
+++ b/include/libnetlink.h
@@ -104,6 +104,27 @@ struct rtnl_ctrl_data {
typedef int (*rtnl_filter_t)(struct nlmsghdr *n, void *);
+/**
+ * rtnl error handler called from
+ * rtnl_dump_done()
+ * rtnl_dump_error()
+ *
+ * Return value is a bitmask of the following values:
+ * RTNL_LET_NLERR
+ * error handled as usual
+ * RTNL_SUPPRESS_NLMSG_DONE_NLERR
+ * error in nlmsg_type == NLMSG_DONE will be suppressed
+ * RTNL_SUPPRESS_NLMSG_ERROR_NLERR
+ * error in nlmsg_type == NLMSG_ERROR will be suppressed
+ * and nlmsg will be skipped
+ * RTNL_SUPPRESS_NLERR - suppress error in both previous cases
+ */
+#define RTNL_LET_NLERR 0x01
+#define RTNL_SUPPRESS_NLMSG_DONE_NLERR 0x02
+#define RTNL_SUPPRESS_NLMSG_ERROR_NLERR 0x04
+#define RTNL_SUPPRESS_NLERR 0x06
+typedef int (*rtnl_err_hndlr_t)(struct nlmsghdr *n, void *);
+
typedef int (*rtnl_listen_filter_t)(struct rtnl_ctrl_data *,
struct nlmsghdr *n, void *);
@@ -113,6 +134,8 @@ typedef int (*nl_ext_ack_fn_t)(const char *errmsg, uint32_t off,
struct rtnl_dump_filter_arg {
rtnl_filter_t filter;
void *arg1;
+ rtnl_err_hndlr_t errhndlr;
+ void *arg2;
__u16 nc_flags;
};
@@ -121,6 +144,15 @@ int rtnl_dump_filter_nc(struct rtnl_handle *rth,
void *arg, __u16 nc_flags);
#define rtnl_dump_filter(rth, filter, arg) \
rtnl_dump_filter_nc(rth, filter, arg, 0)
+int rtnl_dump_filter_errhndlr_nc(struct rtnl_handle *rth,
+ rtnl_filter_t filter,
+ void *arg1,
+ rtnl_err_hndlr_t errhndlr,
+ void *arg2,
+ __u16 nc_flags);
+#define rtnl_dump_filter_errhndlr(rth, filter, farg, errhndlr, earg) \
+ rtnl_dump_filter_errhndlr_nc(rth, filter, farg, errhndlr, earg, 0)
+
int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n,
struct nlmsghdr **answer)
__attribute__((warn_unused_result));
diff --git a/ip/iproute.c b/ip/iproute.c
index 5853f026..e45f0bea 100644
--- a/ip/iproute.c
+++ b/ip/iproute.c
@@ -1727,6 +1727,18 @@ static int iproute_flush(int family, rtnl_filter_t filter_fn)
}
}
+static int save_route_errhndlr(struct nlmsghdr *n, void *arg)
+{
+ int err = -*(int *)NLMSG_DATA(n);
+
+ if (n->nlmsg_type == NLMSG_DONE &&
+ filter.tb == RT_TABLE_MAIN &&
+ err == ENOENT)
+ return RTNL_SUPPRESS_NLMSG_DONE_NLERR;
+
+ return RTNL_LET_NLERR;
+}
+
static int iproute_list_flush_or_save(int argc, char **argv, int action)
{
int dump_family = preferred_family;
@@ -1939,7 +1951,8 @@ static int iproute_list_flush_or_save(int argc, char **argv, int action)
new_json_obj(json);
- if (rtnl_dump_filter(&rth, filter_fn, stdout) < 0) {
+ if (rtnl_dump_filter_errhndlr(&rth, filter_fn, stdout,
+ save_route_errhndlr, NULL) < 0) {
fprintf(stderr, "Dump terminated\n");
return -2;
}
diff --git a/lib/libnetlink.c b/lib/libnetlink.c
index c958aa57..80a92e6f 100644
--- a/lib/libnetlink.c
+++ b/lib/libnetlink.c
@@ -673,7 +673,8 @@ int rtnl_dump_request_n(struct rtnl_handle *rth, struct nlmsghdr *n)
return sendmsg(rth->fd, &msg, 0);
}
-static int rtnl_dump_done(struct nlmsghdr *h)
+static int rtnl_dump_done(struct nlmsghdr *h,
+ const struct rtnl_dump_filter_arg *a)
{
int len = *(int *)NLMSG_DATA(h);
@@ -683,11 +684,15 @@ static int rtnl_dump_done(struct nlmsghdr *h)
}
if (len < 0) {
+ errno = -len;
+
+ if (a->errhndlr(h, a->arg2) & RTNL_SUPPRESS_NLMSG_DONE_NLERR)
+ return 0;
+
/* check for any messages returned from kernel */
if (nl_dump_ext_ack_done(h, len))
return len;
- errno = -len;
switch (errno) {
case ENOENT:
case EOPNOTSUPP:
@@ -708,8 +713,9 @@ static int rtnl_dump_done(struct nlmsghdr *h)
return 0;
}
-static void rtnl_dump_error(const struct rtnl_handle *rth,
- struct nlmsghdr *h)
+static int rtnl_dump_error(const struct rtnl_handle *rth,
+ struct nlmsghdr *h,
+ const struct rtnl_dump_filter_arg *a)
{
if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) {
@@ -721,11 +727,16 @@ static void rtnl_dump_error(const struct rtnl_handle *rth,
if (rth->proto == NETLINK_SOCK_DIAG &&
(errno == ENOENT ||
errno == EOPNOTSUPP))
- return;
+ return -1;
+
+ if (a->errhndlr(h, a->arg2) & RTNL_SUPPRESS_NLMSG_ERROR_NLERR)
+ return 0;
if (!(rth->flags & RTNL_HANDLE_F_SUPPRESS_NLERR))
perror("RTNETLINK answers");
}
+
+ return -1;
}
static int __rtnl_recvmsg(int fd, struct msghdr *msg, int flags)
@@ -834,7 +845,7 @@ static int rtnl_dump_filter_l(struct rtnl_handle *rth,
dump_intr = 1;
if (h->nlmsg_type == NLMSG_DONE) {
- err = rtnl_dump_done(h);
+ err = rtnl_dump_done(h, a);
if (err < 0) {
free(buf);
return -1;
@@ -845,9 +856,13 @@ static int rtnl_dump_filter_l(struct rtnl_handle *rth,
}
if (h->nlmsg_type == NLMSG_ERROR) {
- rtnl_dump_error(rth, h);
- free(buf);
- return -1;
+ err = rtnl_dump_error(rth, h, a);
+ if (err < 0) {
+ free(buf);
+ return -1;
+ }
+
+ goto skip_it;
}
if (!rth->dump_fp) {
@@ -887,8 +902,27 @@ int rtnl_dump_filter_nc(struct rtnl_handle *rth,
void *arg1, __u16 nc_flags)
{
const struct rtnl_dump_filter_arg a[2] = {
- { .filter = filter, .arg1 = arg1, .nc_flags = nc_flags, },
- { .filter = NULL, .arg1 = NULL, .nc_flags = 0, },
+ { .filter = filter, .arg1 = arg1,
+ .errhndlr = NULL, .arg2 = NULL, .nc_flags = nc_flags, },
+ { .filter = NULL, .arg1 = NULL,
+ .errhndlr = NULL, .arg2 = NULL, .nc_flags = 0, },
+ };
+
+ return rtnl_dump_filter_l(rth, a);
+}
+
+int rtnl_dump_filter_errhndlr_nc(struct rtnl_handle *rth,
+ rtnl_filter_t filter,
+ void *arg1,
+ rtnl_err_hndlr_t errhndlr,
+ void *arg2,
+ __u16 nc_flags)
+{
+ const struct rtnl_dump_filter_arg a[2] = {
+ { .filter = filter, .arg1 = arg1,
+ .errhndlr = errhndlr, .arg2 = arg2, .nc_flags = nc_flags, },
+ { .filter = NULL, .arg1 = NULL,
+ .errhndlr = NULL, .arg2 = NULL, .nc_flags = 0, },
};
return rtnl_dump_filter_l(rth, a);
--
2.31.1
^ permalink raw reply related [flat|nested] 31+ messages in thread* Re: [PATCHv4 iproute2] ip route: ignore ENOENT during save if RT_TABLE_MAIN is being dumped
2021-06-29 15:51 ` [PATCHv4 " Alexander Mikhalitsyn
@ 2021-07-06 7:47 ` Alexander Mikhalitsyn
2021-07-06 15:34 ` Stephen Hemminger
1 sibling, 0 replies; 31+ messages in thread
From: Alexander Mikhalitsyn @ 2021-07-06 7:47 UTC (permalink / raw)
To: Alexander Mikhalitsyn
Cc: netdev, David Ahern, Stephen Hemminger, Andrei Vagin,
Alexander Mikhalitsyn
On Tue, 29 Jun 2021 18:51:15 +0300
Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
> We started to use in-kernel filtering feature which allows to get only needed
> tables (see iproute_dump_filter()). From the kernel side it's implemented in
> net/ipv4/fib_frontend.c (inet_dump_fib), net/ipv6/ip6_fib.c (inet6_dump_fib).
> The problem here is that behaviour of "ip route save" was changed after
> c7e6371bc ("ip route: Add protocol, table id and device to dump request").
> If filters are used, then kernel returns ENOENT error if requested table is absent,
> but in newly created net namespace even RT_TABLE_MAIN table doesn't exist.
> It is really allocated, for instance, after issuing "ip l set lo up".
>
> Reproducer is fairly simple:
> $ unshare -n ip route save > dump
> Error: ipv4: FIB table does not exist.
> Dump terminated
>
> Expected result here is to get empty dump file (as it was before this change).
>
> v2: reworked, so, now it takes into account NLMSGERR_ATTR_MSG
> (see nl_dump_ext_ack_done() function). We want to suppress error messages
> in stderr about absent FIB table from kernel too.
>
> v3: reworked to make code clearer. Introduced rtnl_suppressed_errors(),
> rtnl_suppress_error() helpers. User may suppress up to 3 errors (may be
> easily extened by changing SUPPRESS_ERRORS_INIT macro).
>
> v4: reworked, rtnl_dump_filter_errhndlr() was introduced. Thanks
> to Stephen Hemminger for comments and suggestions
>
> Fixes: c7e6371bc ("ip route: Add protocol, table id and device to dump request")
> Cc: David Ahern <dsahern@gmail.com>
> Cc: Stephen Hemminger <stephen@networkplumber.org>
> Cc: Andrei Vagin <avagin@gmail.com>
> Cc: Alexander Mikhalitsyn <alexander@mihalicyn.com>
> Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>
> ---
> include/libnetlink.h | 32 +++++++++++++++++++++++++
> ip/iproute.c | 15 +++++++++++-
> lib/libnetlink.c | 56 +++++++++++++++++++++++++++++++++++---------
> 3 files changed, 91 insertions(+), 12 deletions(-)
>
> diff --git a/include/libnetlink.h b/include/libnetlink.h
> index b9073a6a..4545e5e5 100644
> --- a/include/libnetlink.h
> +++ b/include/libnetlink.h
> @@ -104,6 +104,27 @@ struct rtnl_ctrl_data {
>
> typedef int (*rtnl_filter_t)(struct nlmsghdr *n, void *);
>
> +/**
> + * rtnl error handler called from
> + * rtnl_dump_done()
> + * rtnl_dump_error()
> + *
> + * Return value is a bitmask of the following values:
> + * RTNL_LET_NLERR
> + * error handled as usual
> + * RTNL_SUPPRESS_NLMSG_DONE_NLERR
> + * error in nlmsg_type == NLMSG_DONE will be suppressed
> + * RTNL_SUPPRESS_NLMSG_ERROR_NLERR
> + * error in nlmsg_type == NLMSG_ERROR will be suppressed
> + * and nlmsg will be skipped
> + * RTNL_SUPPRESS_NLERR - suppress error in both previous cases
> + */
> +#define RTNL_LET_NLERR 0x01
> +#define RTNL_SUPPRESS_NLMSG_DONE_NLERR 0x02
> +#define RTNL_SUPPRESS_NLMSG_ERROR_NLERR 0x04
> +#define RTNL_SUPPRESS_NLERR 0x06
> +typedef int (*rtnl_err_hndlr_t)(struct nlmsghdr *n, void *);
> +
> typedef int (*rtnl_listen_filter_t)(struct rtnl_ctrl_data *,
> struct nlmsghdr *n, void *);
>
> @@ -113,6 +134,8 @@ typedef int (*nl_ext_ack_fn_t)(const char *errmsg, uint32_t off,
> struct rtnl_dump_filter_arg {
> rtnl_filter_t filter;
> void *arg1;
> + rtnl_err_hndlr_t errhndlr;
> + void *arg2;
> __u16 nc_flags;
> };
>
> @@ -121,6 +144,15 @@ int rtnl_dump_filter_nc(struct rtnl_handle *rth,
> void *arg, __u16 nc_flags);
> #define rtnl_dump_filter(rth, filter, arg) \
> rtnl_dump_filter_nc(rth, filter, arg, 0)
> +int rtnl_dump_filter_errhndlr_nc(struct rtnl_handle *rth,
> + rtnl_filter_t filter,
> + void *arg1,
> + rtnl_err_hndlr_t errhndlr,
> + void *arg2,
> + __u16 nc_flags);
> +#define rtnl_dump_filter_errhndlr(rth, filter, farg, errhndlr, earg) \
> + rtnl_dump_filter_errhndlr_nc(rth, filter, farg, errhndlr, earg, 0)
> +
> int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n,
> struct nlmsghdr **answer)
> __attribute__((warn_unused_result));
> diff --git a/ip/iproute.c b/ip/iproute.c
> index 5853f026..e45f0bea 100644
> --- a/ip/iproute.c
> +++ b/ip/iproute.c
> @@ -1727,6 +1727,18 @@ static int iproute_flush(int family, rtnl_filter_t filter_fn)
> }
> }
>
> +static int save_route_errhndlr(struct nlmsghdr *n, void *arg)
> +{
> + int err = -*(int *)NLMSG_DATA(n);
> +
> + if (n->nlmsg_type == NLMSG_DONE &&
> + filter.tb == RT_TABLE_MAIN &&
> + err == ENOENT)
> + return RTNL_SUPPRESS_NLMSG_DONE_NLERR;
> +
> + return RTNL_LET_NLERR;
> +}
> +
> static int iproute_list_flush_or_save(int argc, char **argv, int action)
> {
> int dump_family = preferred_family;
> @@ -1939,7 +1951,8 @@ static int iproute_list_flush_or_save(int argc, char **argv, int action)
>
> new_json_obj(json);
>
> - if (rtnl_dump_filter(&rth, filter_fn, stdout) < 0) {
> + if (rtnl_dump_filter_errhndlr(&rth, filter_fn, stdout,
> + save_route_errhndlr, NULL) < 0) {
> fprintf(stderr, "Dump terminated\n");
> return -2;
> }
> diff --git a/lib/libnetlink.c b/lib/libnetlink.c
> index c958aa57..80a92e6f 100644
> --- a/lib/libnetlink.c
> +++ b/lib/libnetlink.c
> @@ -673,7 +673,8 @@ int rtnl_dump_request_n(struct rtnl_handle *rth, struct nlmsghdr *n)
> return sendmsg(rth->fd, &msg, 0);
> }
>
> -static int rtnl_dump_done(struct nlmsghdr *h)
> +static int rtnl_dump_done(struct nlmsghdr *h,
> + const struct rtnl_dump_filter_arg *a)
> {
> int len = *(int *)NLMSG_DATA(h);
>
> @@ -683,11 +684,15 @@ static int rtnl_dump_done(struct nlmsghdr *h)
> }
>
> if (len < 0) {
> + errno = -len;
> +
> + if (a->errhndlr(h, a->arg2) & RTNL_SUPPRESS_NLMSG_DONE_NLERR)
> + return 0;
> +
> /* check for any messages returned from kernel */
> if (nl_dump_ext_ack_done(h, len))
> return len;
>
> - errno = -len;
> switch (errno) {
> case ENOENT:
> case EOPNOTSUPP:
> @@ -708,8 +713,9 @@ static int rtnl_dump_done(struct nlmsghdr *h)
> return 0;
> }
>
> -static void rtnl_dump_error(const struct rtnl_handle *rth,
> - struct nlmsghdr *h)
> +static int rtnl_dump_error(const struct rtnl_handle *rth,
> + struct nlmsghdr *h,
> + const struct rtnl_dump_filter_arg *a)
> {
>
> if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) {
> @@ -721,11 +727,16 @@ static void rtnl_dump_error(const struct rtnl_handle *rth,
> if (rth->proto == NETLINK_SOCK_DIAG &&
> (errno == ENOENT ||
> errno == EOPNOTSUPP))
> - return;
> + return -1;
> +
> + if (a->errhndlr(h, a->arg2) & RTNL_SUPPRESS_NLMSG_ERROR_NLERR)
> + return 0;
>
> if (!(rth->flags & RTNL_HANDLE_F_SUPPRESS_NLERR))
> perror("RTNETLINK answers");
> }
> +
> + return -1;
> }
>
> static int __rtnl_recvmsg(int fd, struct msghdr *msg, int flags)
> @@ -834,7 +845,7 @@ static int rtnl_dump_filter_l(struct rtnl_handle *rth,
> dump_intr = 1;
>
> if (h->nlmsg_type == NLMSG_DONE) {
> - err = rtnl_dump_done(h);
> + err = rtnl_dump_done(h, a);
> if (err < 0) {
> free(buf);
> return -1;
> @@ -845,9 +856,13 @@ static int rtnl_dump_filter_l(struct rtnl_handle *rth,
> }
>
> if (h->nlmsg_type == NLMSG_ERROR) {
> - rtnl_dump_error(rth, h);
> - free(buf);
> - return -1;
> + err = rtnl_dump_error(rth, h, a);
> + if (err < 0) {
> + free(buf);
> + return -1;
> + }
> +
> + goto skip_it;
> }
>
> if (!rth->dump_fp) {
> @@ -887,8 +902,27 @@ int rtnl_dump_filter_nc(struct rtnl_handle *rth,
> void *arg1, __u16 nc_flags)
> {
> const struct rtnl_dump_filter_arg a[2] = {
> - { .filter = filter, .arg1 = arg1, .nc_flags = nc_flags, },
> - { .filter = NULL, .arg1 = NULL, .nc_flags = 0, },
> + { .filter = filter, .arg1 = arg1,
> + .errhndlr = NULL, .arg2 = NULL, .nc_flags = nc_flags, },
> + { .filter = NULL, .arg1 = NULL,
> + .errhndlr = NULL, .arg2 = NULL, .nc_flags = 0, },
> + };
> +
> + return rtnl_dump_filter_l(rth, a);
> +}
> +
> +int rtnl_dump_filter_errhndlr_nc(struct rtnl_handle *rth,
> + rtnl_filter_t filter,
> + void *arg1,
> + rtnl_err_hndlr_t errhndlr,
> + void *arg2,
> + __u16 nc_flags)
> +{
> + const struct rtnl_dump_filter_arg a[2] = {
> + { .filter = filter, .arg1 = arg1,
> + .errhndlr = errhndlr, .arg2 = arg2, .nc_flags = nc_flags, },
> + { .filter = NULL, .arg1 = NULL,
> + .errhndlr = NULL, .arg2 = NULL, .nc_flags = 0, },
> };
>
> return rtnl_dump_filter_l(rth, a);
> --
> 2.31.1
>
gentle ping
^ permalink raw reply [flat|nested] 31+ messages in thread* Re: [PATCHv4 iproute2] ip route: ignore ENOENT during save if RT_TABLE_MAIN is being dumped
2021-06-29 15:51 ` [PATCHv4 " Alexander Mikhalitsyn
2021-07-06 7:47 ` Alexander Mikhalitsyn
@ 2021-07-06 15:34 ` Stephen Hemminger
2021-07-06 15:44 ` Alexander Mikhalitsyn
1 sibling, 1 reply; 31+ messages in thread
From: Stephen Hemminger @ 2021-07-06 15:34 UTC (permalink / raw)
To: Alexander Mikhalitsyn
Cc: netdev, David Ahern, Andrei Vagin, Alexander Mikhalitsyn
On Tue, 29 Jun 2021 18:51:15 +0300
Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
> + const struct rtnl_dump_filter_arg a[2] = {
> + { .filter = filter, .arg1 = arg1,
> + .errhndlr = errhndlr, .arg2 = arg2, .nc_flags = nc_flags, },
> + { .filter = NULL, .arg1 = NULL,
> + .errhndlr = NULL, .arg2 = NULL, .nc_flags = 0, },
> };
I am OK with this as is. But you don't need to add initializers for fields
that are 0/NULL (at least in C).
So could be:
const struct rtnl_dump_filter_arg a[] = {
{ .filter = filter, .arg1 = arg1,
.errhndlr = errhndlr, .arg2 = arg2, .nc_flags = nc_flags, },
{ },
};
^ permalink raw reply [flat|nested] 31+ messages in thread* Re: [PATCHv4 iproute2] ip route: ignore ENOENT during save if RT_TABLE_MAIN is being dumped
2021-07-06 15:34 ` Stephen Hemminger
@ 2021-07-06 15:44 ` Alexander Mikhalitsyn
2021-07-06 16:18 ` Stephen Hemminger
0 siblings, 1 reply; 31+ messages in thread
From: Alexander Mikhalitsyn @ 2021-07-06 15:44 UTC (permalink / raw)
To: Stephen Hemminger
Cc: netdev, David Ahern, Andrei Vagin, Alexander Mikhalitsyn
On Tue, 6 Jul 2021 08:34:07 -0700
Stephen Hemminger <stephen@networkplumber.org> wrote:
> On Tue, 29 Jun 2021 18:51:15 +0300
> Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
>
> > + const struct rtnl_dump_filter_arg a[2] = {
> > + { .filter = filter, .arg1 = arg1,
> > + .errhndlr = errhndlr, .arg2 = arg2, .nc_flags = nc_flags, },
> > + { .filter = NULL, .arg1 = NULL,
> > + .errhndlr = NULL, .arg2 = NULL, .nc_flags = 0, },
> > };
>
> I am OK with this as is. But you don't need to add initializers for fields
> that are 0/NULL (at least in C).
Sure, I've made such explicit initializations just because in original
rtnl_dump_filter_nc() we already have them.
Do I need to resend with fixed initializations? ;)
>
> So could be:
> const struct rtnl_dump_filter_arg a[] = {
> { .filter = filter, .arg1 = arg1,
> .errhndlr = errhndlr, .arg2 = arg2, .nc_flags = nc_flags, },
> { },
> };
Thanks,
Alex
^ permalink raw reply [flat|nested] 31+ messages in thread* Re: [PATCHv4 iproute2] ip route: ignore ENOENT during save if RT_TABLE_MAIN is being dumped
2021-07-06 15:44 ` Alexander Mikhalitsyn
@ 2021-07-06 16:18 ` Stephen Hemminger
2021-07-06 17:17 ` Alexander Mikhalitsyn
0 siblings, 1 reply; 31+ messages in thread
From: Stephen Hemminger @ 2021-07-06 16:18 UTC (permalink / raw)
To: Alexander Mikhalitsyn
Cc: netdev, David Ahern, Andrei Vagin, Alexander Mikhalitsyn
On Tue, 6 Jul 2021 18:44:15 +0300
Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
> On Tue, 6 Jul 2021 08:34:07 -0700
> Stephen Hemminger <stephen@networkplumber.org> wrote:
>
> > On Tue, 29 Jun 2021 18:51:15 +0300
> > Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
> >
> > > + const struct rtnl_dump_filter_arg a[2] = {
> > > + { .filter = filter, .arg1 = arg1,
> > > + .errhndlr = errhndlr, .arg2 = arg2, .nc_flags = nc_flags, },
> > > + { .filter = NULL, .arg1 = NULL,
> > > + .errhndlr = NULL, .arg2 = NULL, .nc_flags = 0, },
> > > };
> >
> > I am OK with this as is. But you don't need to add initializers for fields
> > that are 0/NULL (at least in C).
>
> Sure, I've made such explicit initializations just because in original
> rtnl_dump_filter_nc() we already have them.
>
> Do I need to resend with fixed initializations? ;)
Not worth it
^ permalink raw reply [flat|nested] 31+ messages in thread* Re: [PATCHv4 iproute2] ip route: ignore ENOENT during save if RT_TABLE_MAIN is being dumped
2021-07-06 16:18 ` Stephen Hemminger
@ 2021-07-06 17:17 ` Alexander Mikhalitsyn
2021-07-07 0:05 ` Stephen Hemminger
0 siblings, 1 reply; 31+ messages in thread
From: Alexander Mikhalitsyn @ 2021-07-06 17:17 UTC (permalink / raw)
To: Stephen Hemminger
Cc: netdev, David Ahern, Andrei Vagin, Alexander Mikhalitsyn
On Tue, 6 Jul 2021 09:18:21 -0700
Stephen Hemminger <stephen@networkplumber.org> wrote:
> On Tue, 6 Jul 2021 18:44:15 +0300
> Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
>
> > On Tue, 6 Jul 2021 08:34:07 -0700
> > Stephen Hemminger <stephen@networkplumber.org> wrote:
> >
> > > On Tue, 29 Jun 2021 18:51:15 +0300
> > > Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
> > >
> > > > + const struct rtnl_dump_filter_arg a[2] = {
> > > > + { .filter = filter, .arg1 = arg1,
> > > > + .errhndlr = errhndlr, .arg2 = arg2, .nc_flags = nc_flags, },
> > > > + { .filter = NULL, .arg1 = NULL,
> > > > + .errhndlr = NULL, .arg2 = NULL, .nc_flags = 0, },
> > > > };
> > >
> > > I am OK with this as is. But you don't need to add initializers for fields
> > > that are 0/NULL (at least in C).
> >
> > Sure, I've made such explicit initializations just because in original
> > rtnl_dump_filter_nc() we already have them.
> >
> > Do I need to resend with fixed initializations? ;)
>
> Not worth it
Ok, thanks!
^ permalink raw reply [flat|nested] 31+ messages in thread* Re: [PATCHv4 iproute2] ip route: ignore ENOENT during save if RT_TABLE_MAIN is being dumped
2021-07-06 17:17 ` Alexander Mikhalitsyn
@ 2021-07-07 0:05 ` Stephen Hemminger
2021-07-07 12:22 ` Alexander Mikhalitsyn
0 siblings, 1 reply; 31+ messages in thread
From: Stephen Hemminger @ 2021-07-07 0:05 UTC (permalink / raw)
To: Alexander Mikhalitsyn
Cc: netdev, David Ahern, Andrei Vagin, Alexander Mikhalitsyn
On Tue, 6 Jul 2021 20:17:57 +0300
Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
> On Tue, 6 Jul 2021 09:18:21 -0700
> Stephen Hemminger <stephen@networkplumber.org> wrote:
>
> > On Tue, 6 Jul 2021 18:44:15 +0300
> > Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
> >
> > > On Tue, 6 Jul 2021 08:34:07 -0700
> > > Stephen Hemminger <stephen@networkplumber.org> wrote:
> > >
> > > > On Tue, 29 Jun 2021 18:51:15 +0300
> > > > Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
> > > >
> > > > > + const struct rtnl_dump_filter_arg a[2] = {
> > > > > + { .filter = filter, .arg1 = arg1,
> > > > > + .errhndlr = errhndlr, .arg2 = arg2, .nc_flags = nc_flags, },
> > > > > + { .filter = NULL, .arg1 = NULL,
> > > > > + .errhndlr = NULL, .arg2 = NULL, .nc_flags = 0, },
> > > > > };
> > > >
> > > > I am OK with this as is. But you don't need to add initializers for fields
> > > > that are 0/NULL (at least in C).
> > >
> > > Sure, I've made such explicit initializations just because in original
> > > rtnl_dump_filter_nc() we already have them.
> > >
> > > Do I need to resend with fixed initializations? ;)
> >
> > Not worth it
>
> Ok, thanks!
>
Looks like you need to send v5 anyway.
checkpatch.pl ~/Downloads/PATCHv4-iproute2-ip-route-ignore-ENOENT-during-save-if-RT_TABLE_MAIN-is-being-dumped.patch
WARNING: Possible unwrapped commit description (prefer a maximum 75 chars per line)
#62:
We started to use in-kernel filtering feature which allows to get only needed
WARNING: 'extened' may be misspelled - perhaps 'extended'?
#84:
easily extened by changing SUPPRESS_ERRORS_INIT macro).
^^^^^^^
WARNING: please, no space before tabs
#111: FILE: include/libnetlink.h:109:
+ * ^Irtnl_dump_done()$
WARNING: please, no space before tabs
#112: FILE: include/libnetlink.h:110:
+ * ^Irtnl_dump_error()$
WARNING: please, no space before tabs
#116: FILE: include/libnetlink.h:114:
+ * ^Ierror handled as usual$
WARNING: please, no space before tabs
#118: FILE: include/libnetlink.h:116:
+ * ^Ierror in nlmsg_type == NLMSG_DONE will be suppressed$
WARNING: please, no space before tabs
#120: FILE: include/libnetlink.h:118:
+ * ^Ierror in nlmsg_type == NLMSG_ERROR will be suppressed$
WARNING: please, no space before tabs
#121: FILE: include/libnetlink.h:119:
+ * ^Iand nlmsg will be skipped$
total: 0 errors, 8 warnings, 183 lines checked
^ permalink raw reply [flat|nested] 31+ messages in thread* Re: [PATCHv4 iproute2] ip route: ignore ENOENT during save if RT_TABLE_MAIN is being dumped
2021-07-07 0:05 ` Stephen Hemminger
@ 2021-07-07 12:22 ` Alexander Mikhalitsyn
2021-07-07 14:31 ` Stephen Hemminger
0 siblings, 1 reply; 31+ messages in thread
From: Alexander Mikhalitsyn @ 2021-07-07 12:22 UTC (permalink / raw)
To: Stephen Hemminger; +Cc: netdev, David Ahern, Alexander Mikhalitsyn
On Tue, 6 Jul 2021 17:05:45 -0700
Stephen Hemminger <stephen@networkplumber.org> wrote:
> On Tue, 6 Jul 2021 20:17:57 +0300
> Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
>
> > On Tue, 6 Jul 2021 09:18:21 -0700
> > Stephen Hemminger <stephen@networkplumber.org> wrote:
> >
> > > On Tue, 6 Jul 2021 18:44:15 +0300
> > > Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
> > >
> > > > On Tue, 6 Jul 2021 08:34:07 -0700
> > > > Stephen Hemminger <stephen@networkplumber.org> wrote:
> > > >
> > > > > On Tue, 29 Jun 2021 18:51:15 +0300
> > > > > Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
> > > > >
> > > > > > + const struct rtnl_dump_filter_arg a[2] = {
> > > > > > + { .filter = filter, .arg1 = arg1,
> > > > > > + .errhndlr = errhndlr, .arg2 = arg2, .nc_flags = nc_flags, },
> > > > > > + { .filter = NULL, .arg1 = NULL,
> > > > > > + .errhndlr = NULL, .arg2 = NULL, .nc_flags = 0, },
> > > > > > };
> > > > >
> > > > > I am OK with this as is. But you don't need to add initializers for fields
> > > > > that are 0/NULL (at least in C).
> > > >
> > > > Sure, I've made such explicit initializations just because in original
> > > > rtnl_dump_filter_nc() we already have them.
> > > >
> > > > Do I need to resend with fixed initializations? ;)
> > >
> > > Not worth it
> >
> > Ok, thanks!
> >
>
> Looks like you need to send v5 anyway.
>
>
> checkpatch.pl ~/Downloads/PATCHv4-iproute2-ip-route-ignore-ENOENT-during-save-if-RT_TABLE_MAIN-is-being-dumped.patch
> WARNING: Possible unwrapped commit description (prefer a maximum 75 chars per line)
> #62:
> We started to use in-kernel filtering feature which allows to get only needed
>
> WARNING: 'extened' may be misspelled - perhaps 'extended'?
> #84:
> easily extened by changing SUPPRESS_ERRORS_INIT macro).
> ^^^^^^^
>
> WARNING: please, no space before tabs
> #111: FILE: include/libnetlink.h:109:
> + * ^Irtnl_dump_done()$
>
> WARNING: please, no space before tabs
> #112: FILE: include/libnetlink.h:110:
> + * ^Irtnl_dump_error()$
>
> WARNING: please, no space before tabs
> #116: FILE: include/libnetlink.h:114:
> + * ^Ierror handled as usual$
>
> WARNING: please, no space before tabs
> #118: FILE: include/libnetlink.h:116:
> + * ^Ierror in nlmsg_type == NLMSG_DONE will be suppressed$
>
>
> WARNING: please, no space before tabs
> #120: FILE: include/libnetlink.h:118:
> + * ^Ierror in nlmsg_type == NLMSG_ERROR will be suppressed$
>
> WARNING: please, no space before tabs
> #121: FILE: include/libnetlink.h:119:
> + * ^Iand nlmsg will be skipped$
>
> total: 0 errors, 8 warnings, 183 lines checked
Oh, sorry about that. I've sent v5 and checked with checkpatch.pl
I've send two options for v5 - with initializers fix and without :)
Regards,
Alex
^ permalink raw reply [flat|nested] 31+ messages in thread* Re: [PATCHv4 iproute2] ip route: ignore ENOENT during save if RT_TABLE_MAIN is being dumped
2021-07-07 12:22 ` Alexander Mikhalitsyn
@ 2021-07-07 14:31 ` Stephen Hemminger
2021-07-07 14:32 ` Alexander Mikhalitsyn
0 siblings, 1 reply; 31+ messages in thread
From: Stephen Hemminger @ 2021-07-07 14:31 UTC (permalink / raw)
To: Alexander Mikhalitsyn; +Cc: netdev, David Ahern, Alexander Mikhalitsyn
On Wed, 7 Jul 2021 15:22:36 +0300
Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
> On Tue, 6 Jul 2021 17:05:45 -0700
> Stephen Hemminger <stephen@networkplumber.org> wrote:
>
> > On Tue, 6 Jul 2021 20:17:57 +0300
> > Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
> >
> > > On Tue, 6 Jul 2021 09:18:21 -0700
> > > Stephen Hemminger <stephen@networkplumber.org> wrote:
> > >
> > > > On Tue, 6 Jul 2021 18:44:15 +0300
> > > > Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
> > > >
> > > > > On Tue, 6 Jul 2021 08:34:07 -0700
> > > > > Stephen Hemminger <stephen@networkplumber.org> wrote:
> > > > >
> > > > > > On Tue, 29 Jun 2021 18:51:15 +0300
> > > > > > Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
> > > > > >
> > > > > > > + const struct rtnl_dump_filter_arg a[2] = {
> > > > > > > + { .filter = filter, .arg1 = arg1,
> > > > > > > + .errhndlr = errhndlr, .arg2 = arg2, .nc_flags = nc_flags, },
> > > > > > > + { .filter = NULL, .arg1 = NULL,
> > > > > > > + .errhndlr = NULL, .arg2 = NULL, .nc_flags = 0, },
> > > > > > > };
> > > > > >
> > > > > > I am OK with this as is. But you don't need to add initializers for fields
> > > > > > that are 0/NULL (at least in C).
> > > > >
> > > > > Sure, I've made such explicit initializations just because in original
> > > > > rtnl_dump_filter_nc() we already have them.
> > > > >
> > > > > Do I need to resend with fixed initializations? ;)
> > > >
> > > > Not worth it
> > >
> > > Ok, thanks!
> > >
> >
> > Looks like you need to send v5 anyway.
> >
> >
> > checkpatch.pl ~/Downloads/PATCHv4-iproute2-ip-route-ignore-ENOENT-during-save-if-RT_TABLE_MAIN-is-being-dumped.patch
> > WARNING: Possible unwrapped commit description (prefer a maximum 75 chars per line)
> > #62:
> > We started to use in-kernel filtering feature which allows to get only needed
> >
> > WARNING: 'extened' may be misspelled - perhaps 'extended'?
> > #84:
> > easily extened by changing SUPPRESS_ERRORS_INIT macro).
> > ^^^^^^^
> >
> > WARNING: please, no space before tabs
> > #111: FILE: include/libnetlink.h:109:
> > + * ^Irtnl_dump_done()$
> >
> > WARNING: please, no space before tabs
> > #112: FILE: include/libnetlink.h:110:
> > + * ^Irtnl_dump_error()$
> >
> > WARNING: please, no space before tabs
> > #116: FILE: include/libnetlink.h:114:
> > + * ^Ierror handled as usual$
> >
> > WARNING: please, no space before tabs
> > #118: FILE: include/libnetlink.h:116:
> > + * ^Ierror in nlmsg_type == NLMSG_DONE will be suppressed$
> >
> >
> > WARNING: please, no space before tabs
> > #120: FILE: include/libnetlink.h:118:
> > + * ^Ierror in nlmsg_type == NLMSG_ERROR will be suppressed$
> >
> > WARNING: please, no space before tabs
> > #121: FILE: include/libnetlink.h:119:
> > + * ^Iand nlmsg will be skipped$
> >
> > total: 0 errors, 8 warnings, 183 lines checked
>
> Oh, sorry about that. I've sent v5 and checked with checkpatch.pl
> I've send two options for v5 - with initializers fix and without :)
>
> Regards,
> Alex
Choose which ever initializer format you think looks best
^ permalink raw reply [flat|nested] 31+ messages in thread* Re: [PATCHv4 iproute2] ip route: ignore ENOENT during save if RT_TABLE_MAIN is being dumped
2021-07-07 14:31 ` Stephen Hemminger
@ 2021-07-07 14:32 ` Alexander Mikhalitsyn
0 siblings, 0 replies; 31+ messages in thread
From: Alexander Mikhalitsyn @ 2021-07-07 14:32 UTC (permalink / raw)
To: Stephen Hemminger; +Cc: netdev, David Ahern, Alexander Mikhalitsyn
On Wed, 7 Jul 2021 07:31:31 -0700
Stephen Hemminger <stephen@networkplumber.org> wrote:
> On Wed, 7 Jul 2021 15:22:36 +0300
> Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
>
> > On Tue, 6 Jul 2021 17:05:45 -0700
> > Stephen Hemminger <stephen@networkplumber.org> wrote:
> >
> > > On Tue, 6 Jul 2021 20:17:57 +0300
> > > Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
> > >
> > > > On Tue, 6 Jul 2021 09:18:21 -0700
> > > > Stephen Hemminger <stephen@networkplumber.org> wrote:
> > > >
> > > > > On Tue, 6 Jul 2021 18:44:15 +0300
> > > > > Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
> > > > >
> > > > > > On Tue, 6 Jul 2021 08:34:07 -0700
> > > > > > Stephen Hemminger <stephen@networkplumber.org> wrote:
> > > > > >
> > > > > > > On Tue, 29 Jun 2021 18:51:15 +0300
> > > > > > > Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
> > > > > > >
> > > > > > > > + const struct rtnl_dump_filter_arg a[2] = {
> > > > > > > > + { .filter = filter, .arg1 = arg1,
> > > > > > > > + .errhndlr = errhndlr, .arg2 = arg2, .nc_flags = nc_flags, },
> > > > > > > > + { .filter = NULL, .arg1 = NULL,
> > > > > > > > + .errhndlr = NULL, .arg2 = NULL, .nc_flags = 0, },
> > > > > > > > };
> > > > > > >
> > > > > > > I am OK with this as is. But you don't need to add initializers for fields
> > > > > > > that are 0/NULL (at least in C).
> > > > > >
> > > > > > Sure, I've made such explicit initializations just because in original
> > > > > > rtnl_dump_filter_nc() we already have them.
> > > > > >
> > > > > > Do I need to resend with fixed initializations? ;)
> > > > >
> > > > > Not worth it
> > > >
> > > > Ok, thanks!
> > > >
> > >
> > > Looks like you need to send v5 anyway.
> > >
> > >
> > > checkpatch.pl ~/Downloads/PATCHv4-iproute2-ip-route-ignore-ENOENT-during-save-if-RT_TABLE_MAIN-is-being-dumped.patch
> > > WARNING: Possible unwrapped commit description (prefer a maximum 75 chars per line)
> > > #62:
> > > We started to use in-kernel filtering feature which allows to get only needed
> > >
> > > WARNING: 'extened' may be misspelled - perhaps 'extended'?
> > > #84:
> > > easily extened by changing SUPPRESS_ERRORS_INIT macro).
> > > ^^^^^^^
> > >
> > > WARNING: please, no space before tabs
> > > #111: FILE: include/libnetlink.h:109:
> > > + * ^Irtnl_dump_done()$
> > >
> > > WARNING: please, no space before tabs
> > > #112: FILE: include/libnetlink.h:110:
> > > + * ^Irtnl_dump_error()$
> > >
> > > WARNING: please, no space before tabs
> > > #116: FILE: include/libnetlink.h:114:
> > > + * ^Ierror handled as usual$
> > >
> > > WARNING: please, no space before tabs
> > > #118: FILE: include/libnetlink.h:116:
> > > + * ^Ierror in nlmsg_type == NLMSG_DONE will be suppressed$
> > >
> > >
> > > WARNING: please, no space before tabs
> > > #120: FILE: include/libnetlink.h:118:
> > > + * ^Ierror in nlmsg_type == NLMSG_ERROR will be suppressed$
> > >
> > > WARNING: please, no space before tabs
> > > #121: FILE: include/libnetlink.h:119:
> > > + * ^Iand nlmsg will be skipped$
> > >
> > > total: 0 errors, 8 warnings, 183 lines checked
> >
> > Oh, sorry about that. I've sent v5 and checked with checkpatch.pl
> > I've send two options for v5 - with initializers fix and without :)
> >
> > Regards,
> > Alex
>
> Choose which ever initializer format you think looks best
Ha-ha! :) Let's take with empty initializers ;)
Thanks,
Alex
^ permalink raw reply [flat|nested] 31+ messages in thread
* [PATCHv5 iproute2] ip route: ignore ENOENT during save if RT_TABLE_MAIN is being dumped
2021-06-25 10:44 ` [PATCHv3 " Alexander Mikhalitsyn
2021-06-27 21:54 ` Stephen Hemminger
2021-06-29 15:51 ` [PATCHv4 " Alexander Mikhalitsyn
@ 2021-07-07 12:09 ` Alexander Mikhalitsyn
2021-07-07 12:22 ` Alexander Mikhalitsyn
3 siblings, 0 replies; 31+ messages in thread
From: Alexander Mikhalitsyn @ 2021-07-07 12:09 UTC (permalink / raw)
To: netdev
Cc: Alexander Mikhalitsyn, David Ahern, Stephen Hemminger,
Andrei Vagin, Alexander Mikhalitsyn
We started to use in-kernel filtering feature which allows to get only
needed tables (see iproute_dump_filter()). From the kernel side it's
implemented in net/ipv4/fib_frontend.c (inet_dump_fib), net/ipv6/ip6_fib.c
(inet6_dump_fib). The problem here is that behaviour of "ip route save"
was changed after
c7e6371bc ("ip route: Add protocol, table id and device to dump request").
If filters are used, then kernel returns ENOENT error if requested table
is absent, but in newly created net namespace even RT_TABLE_MAIN table
doesn't exist. It is really allocated, for instance, after issuing
"ip l set lo up".
Reproducer is fairly simple:
$ unshare -n ip route save > dump
Error: ipv4: FIB table does not exist.
Dump terminated
Expected result here is to get empty dump file (as it was before this
change).
v2: reworked, so, now it takes into account NLMSGERR_ATTR_MSG
(see nl_dump_ext_ack_done() function). We want to suppress error messages
in stderr about absent FIB table from kernel too.
v3: reworked to make code clearer. Introduced rtnl_suppressed_errors(),
rtnl_suppress_error() helpers. User may suppress up to 3 errors (may be
easily extended by changing SUPPRESS_ERRORS_INIT macro).
v4: reworked, rtnl_dump_filter_errhndlr() was introduced. Thanks
to Stephen Hemminger for comments and suggestions
v5: space fixes, commit message reformat
Fixes: c7e6371bc ("ip route: Add protocol, table id and device to dump request")
Cc: David Ahern <dsahern@gmail.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Alexander Mikhalitsyn <alexander@mihalicyn.com>
Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>
---
include/libnetlink.h | 32 +++++++++++++++++++++++++
ip/iproute.c | 15 +++++++++++-
lib/libnetlink.c | 56 +++++++++++++++++++++++++++++++++++---------
3 files changed, 91 insertions(+), 12 deletions(-)
diff --git a/include/libnetlink.h b/include/libnetlink.h
index b9073a6a..4401551f 100644
--- a/include/libnetlink.h
+++ b/include/libnetlink.h
@@ -104,6 +104,27 @@ struct rtnl_ctrl_data {
typedef int (*rtnl_filter_t)(struct nlmsghdr *n, void *);
+/**
+ * rtnl error handler called from
+ * rtnl_dump_done()
+ * rtnl_dump_error()
+ *
+ * Return value is a bitmask of the following values:
+ * RTNL_LET_NLERR
+ * error handled as usual
+ * RTNL_SUPPRESS_NLMSG_DONE_NLERR
+ * error in nlmsg_type == NLMSG_DONE will be suppressed
+ * RTNL_SUPPRESS_NLMSG_ERROR_NLERR
+ * error in nlmsg_type == NLMSG_ERROR will be suppressed
+ * and nlmsg will be skipped
+ * RTNL_SUPPRESS_NLERR - suppress error in both previous cases
+ */
+#define RTNL_LET_NLERR 0x01
+#define RTNL_SUPPRESS_NLMSG_DONE_NLERR 0x02
+#define RTNL_SUPPRESS_NLMSG_ERROR_NLERR 0x04
+#define RTNL_SUPPRESS_NLERR 0x06
+typedef int (*rtnl_err_hndlr_t)(struct nlmsghdr *n, void *);
+
typedef int (*rtnl_listen_filter_t)(struct rtnl_ctrl_data *,
struct nlmsghdr *n, void *);
@@ -113,6 +134,8 @@ typedef int (*nl_ext_ack_fn_t)(const char *errmsg, uint32_t off,
struct rtnl_dump_filter_arg {
rtnl_filter_t filter;
void *arg1;
+ rtnl_err_hndlr_t errhndlr;
+ void *arg2;
__u16 nc_flags;
};
@@ -121,6 +144,15 @@ int rtnl_dump_filter_nc(struct rtnl_handle *rth,
void *arg, __u16 nc_flags);
#define rtnl_dump_filter(rth, filter, arg) \
rtnl_dump_filter_nc(rth, filter, arg, 0)
+int rtnl_dump_filter_errhndlr_nc(struct rtnl_handle *rth,
+ rtnl_filter_t filter,
+ void *arg1,
+ rtnl_err_hndlr_t errhndlr,
+ void *arg2,
+ __u16 nc_flags);
+#define rtnl_dump_filter_errhndlr(rth, filter, farg, errhndlr, earg) \
+ rtnl_dump_filter_errhndlr_nc(rth, filter, farg, errhndlr, earg, 0)
+
int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n,
struct nlmsghdr **answer)
__attribute__((warn_unused_result));
diff --git a/ip/iproute.c b/ip/iproute.c
index 5853f026..e45f0bea 100644
--- a/ip/iproute.c
+++ b/ip/iproute.c
@@ -1727,6 +1727,18 @@ static int iproute_flush(int family, rtnl_filter_t filter_fn)
}
}
+static int save_route_errhndlr(struct nlmsghdr *n, void *arg)
+{
+ int err = -*(int *)NLMSG_DATA(n);
+
+ if (n->nlmsg_type == NLMSG_DONE &&
+ filter.tb == RT_TABLE_MAIN &&
+ err == ENOENT)
+ return RTNL_SUPPRESS_NLMSG_DONE_NLERR;
+
+ return RTNL_LET_NLERR;
+}
+
static int iproute_list_flush_or_save(int argc, char **argv, int action)
{
int dump_family = preferred_family;
@@ -1939,7 +1951,8 @@ static int iproute_list_flush_or_save(int argc, char **argv, int action)
new_json_obj(json);
- if (rtnl_dump_filter(&rth, filter_fn, stdout) < 0) {
+ if (rtnl_dump_filter_errhndlr(&rth, filter_fn, stdout,
+ save_route_errhndlr, NULL) < 0) {
fprintf(stderr, "Dump terminated\n");
return -2;
}
diff --git a/lib/libnetlink.c b/lib/libnetlink.c
index c958aa57..80a92e6f 100644
--- a/lib/libnetlink.c
+++ b/lib/libnetlink.c
@@ -673,7 +673,8 @@ int rtnl_dump_request_n(struct rtnl_handle *rth, struct nlmsghdr *n)
return sendmsg(rth->fd, &msg, 0);
}
-static int rtnl_dump_done(struct nlmsghdr *h)
+static int rtnl_dump_done(struct nlmsghdr *h,
+ const struct rtnl_dump_filter_arg *a)
{
int len = *(int *)NLMSG_DATA(h);
@@ -683,11 +684,15 @@ static int rtnl_dump_done(struct nlmsghdr *h)
}
if (len < 0) {
+ errno = -len;
+
+ if (a->errhndlr(h, a->arg2) & RTNL_SUPPRESS_NLMSG_DONE_NLERR)
+ return 0;
+
/* check for any messages returned from kernel */
if (nl_dump_ext_ack_done(h, len))
return len;
- errno = -len;
switch (errno) {
case ENOENT:
case EOPNOTSUPP:
@@ -708,8 +713,9 @@ static int rtnl_dump_done(struct nlmsghdr *h)
return 0;
}
-static void rtnl_dump_error(const struct rtnl_handle *rth,
- struct nlmsghdr *h)
+static int rtnl_dump_error(const struct rtnl_handle *rth,
+ struct nlmsghdr *h,
+ const struct rtnl_dump_filter_arg *a)
{
if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) {
@@ -721,11 +727,16 @@ static void rtnl_dump_error(const struct rtnl_handle *rth,
if (rth->proto == NETLINK_SOCK_DIAG &&
(errno == ENOENT ||
errno == EOPNOTSUPP))
- return;
+ return -1;
+
+ if (a->errhndlr(h, a->arg2) & RTNL_SUPPRESS_NLMSG_ERROR_NLERR)
+ return 0;
if (!(rth->flags & RTNL_HANDLE_F_SUPPRESS_NLERR))
perror("RTNETLINK answers");
}
+
+ return -1;
}
static int __rtnl_recvmsg(int fd, struct msghdr *msg, int flags)
@@ -834,7 +845,7 @@ static int rtnl_dump_filter_l(struct rtnl_handle *rth,
dump_intr = 1;
if (h->nlmsg_type == NLMSG_DONE) {
- err = rtnl_dump_done(h);
+ err = rtnl_dump_done(h, a);
if (err < 0) {
free(buf);
return -1;
@@ -845,9 +856,13 @@ static int rtnl_dump_filter_l(struct rtnl_handle *rth,
}
if (h->nlmsg_type == NLMSG_ERROR) {
- rtnl_dump_error(rth, h);
- free(buf);
- return -1;
+ err = rtnl_dump_error(rth, h, a);
+ if (err < 0) {
+ free(buf);
+ return -1;
+ }
+
+ goto skip_it;
}
if (!rth->dump_fp) {
@@ -887,8 +902,27 @@ int rtnl_dump_filter_nc(struct rtnl_handle *rth,
void *arg1, __u16 nc_flags)
{
const struct rtnl_dump_filter_arg a[2] = {
- { .filter = filter, .arg1 = arg1, .nc_flags = nc_flags, },
- { .filter = NULL, .arg1 = NULL, .nc_flags = 0, },
+ { .filter = filter, .arg1 = arg1,
+ .errhndlr = NULL, .arg2 = NULL, .nc_flags = nc_flags, },
+ { .filter = NULL, .arg1 = NULL,
+ .errhndlr = NULL, .arg2 = NULL, .nc_flags = 0, },
+ };
+
+ return rtnl_dump_filter_l(rth, a);
+}
+
+int rtnl_dump_filter_errhndlr_nc(struct rtnl_handle *rth,
+ rtnl_filter_t filter,
+ void *arg1,
+ rtnl_err_hndlr_t errhndlr,
+ void *arg2,
+ __u16 nc_flags)
+{
+ const struct rtnl_dump_filter_arg a[2] = {
+ { .filter = filter, .arg1 = arg1,
+ .errhndlr = errhndlr, .arg2 = arg2, .nc_flags = nc_flags, },
+ { .filter = NULL, .arg1 = NULL,
+ .errhndlr = NULL, .arg2 = NULL, .nc_flags = 0, },
};
return rtnl_dump_filter_l(rth, a);
--
2.31.1
^ permalink raw reply related [flat|nested] 31+ messages in thread* [PATCHv5 iproute2] ip route: ignore ENOENT during save if RT_TABLE_MAIN is being dumped
2021-06-25 10:44 ` [PATCHv3 " Alexander Mikhalitsyn
` (2 preceding siblings ...)
2021-07-07 12:09 ` [PATCHv5 " Alexander Mikhalitsyn
@ 2021-07-07 12:22 ` Alexander Mikhalitsyn
2021-07-07 14:35 ` Stephen Hemminger
2021-07-07 14:50 ` patchwork-bot+netdevbpf
3 siblings, 2 replies; 31+ messages in thread
From: Alexander Mikhalitsyn @ 2021-07-07 12:22 UTC (permalink / raw)
To: netdev
Cc: Alexander Mikhalitsyn, David Ahern, Stephen Hemminger,
Andrei Vagin, Alexander Mikhalitsyn
We started to use in-kernel filtering feature which allows to get only
needed tables (see iproute_dump_filter()). From the kernel side it's
implemented in net/ipv4/fib_frontend.c (inet_dump_fib), net/ipv6/ip6_fib.c
(inet6_dump_fib). The problem here is that behaviour of "ip route save"
was changed after
c7e6371bc ("ip route: Add protocol, table id and device to dump request").
If filters are used, then kernel returns ENOENT error if requested table
is absent, but in newly created net namespace even RT_TABLE_MAIN table
doesn't exist. It is really allocated, for instance, after issuing
"ip l set lo up".
Reproducer is fairly simple:
$ unshare -n ip route save > dump
Error: ipv4: FIB table does not exist.
Dump terminated
Expected result here is to get empty dump file (as it was before this
change).
v2: reworked, so, now it takes into account NLMSGERR_ATTR_MSG
(see nl_dump_ext_ack_done() function). We want to suppress error messages
in stderr about absent FIB table from kernel too.
v3: reworked to make code clearer. Introduced rtnl_suppressed_errors(),
rtnl_suppress_error() helpers. User may suppress up to 3 errors (may be
easily extended by changing SUPPRESS_ERRORS_INIT macro).
v4: reworked, rtnl_dump_filter_errhndlr() was introduced. Thanks
to Stephen Hemminger for comments and suggestions
v5: space fixes, commit message reformat, empty initializers
Fixes: c7e6371bc ("ip route: Add protocol, table id and device to dump request")
Cc: David Ahern <dsahern@gmail.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Alexander Mikhalitsyn <alexander@mihalicyn.com>
Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>
---
include/libnetlink.h | 32 ++++++++++++++++++++++++++
ip/iproute.c | 15 +++++++++++-
lib/libnetlink.c | 54 +++++++++++++++++++++++++++++++++++---------
3 files changed, 89 insertions(+), 12 deletions(-)
diff --git a/include/libnetlink.h b/include/libnetlink.h
index b9073a6a..4401551f 100644
--- a/include/libnetlink.h
+++ b/include/libnetlink.h
@@ -104,6 +104,27 @@ struct rtnl_ctrl_data {
typedef int (*rtnl_filter_t)(struct nlmsghdr *n, void *);
+/**
+ * rtnl error handler called from
+ * rtnl_dump_done()
+ * rtnl_dump_error()
+ *
+ * Return value is a bitmask of the following values:
+ * RTNL_LET_NLERR
+ * error handled as usual
+ * RTNL_SUPPRESS_NLMSG_DONE_NLERR
+ * error in nlmsg_type == NLMSG_DONE will be suppressed
+ * RTNL_SUPPRESS_NLMSG_ERROR_NLERR
+ * error in nlmsg_type == NLMSG_ERROR will be suppressed
+ * and nlmsg will be skipped
+ * RTNL_SUPPRESS_NLERR - suppress error in both previous cases
+ */
+#define RTNL_LET_NLERR 0x01
+#define RTNL_SUPPRESS_NLMSG_DONE_NLERR 0x02
+#define RTNL_SUPPRESS_NLMSG_ERROR_NLERR 0x04
+#define RTNL_SUPPRESS_NLERR 0x06
+typedef int (*rtnl_err_hndlr_t)(struct nlmsghdr *n, void *);
+
typedef int (*rtnl_listen_filter_t)(struct rtnl_ctrl_data *,
struct nlmsghdr *n, void *);
@@ -113,6 +134,8 @@ typedef int (*nl_ext_ack_fn_t)(const char *errmsg, uint32_t off,
struct rtnl_dump_filter_arg {
rtnl_filter_t filter;
void *arg1;
+ rtnl_err_hndlr_t errhndlr;
+ void *arg2;
__u16 nc_flags;
};
@@ -121,6 +144,15 @@ int rtnl_dump_filter_nc(struct rtnl_handle *rth,
void *arg, __u16 nc_flags);
#define rtnl_dump_filter(rth, filter, arg) \
rtnl_dump_filter_nc(rth, filter, arg, 0)
+int rtnl_dump_filter_errhndlr_nc(struct rtnl_handle *rth,
+ rtnl_filter_t filter,
+ void *arg1,
+ rtnl_err_hndlr_t errhndlr,
+ void *arg2,
+ __u16 nc_flags);
+#define rtnl_dump_filter_errhndlr(rth, filter, farg, errhndlr, earg) \
+ rtnl_dump_filter_errhndlr_nc(rth, filter, farg, errhndlr, earg, 0)
+
int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n,
struct nlmsghdr **answer)
__attribute__((warn_unused_result));
diff --git a/ip/iproute.c b/ip/iproute.c
index 5853f026..e45f0bea 100644
--- a/ip/iproute.c
+++ b/ip/iproute.c
@@ -1727,6 +1727,18 @@ static int iproute_flush(int family, rtnl_filter_t filter_fn)
}
}
+static int save_route_errhndlr(struct nlmsghdr *n, void *arg)
+{
+ int err = -*(int *)NLMSG_DATA(n);
+
+ if (n->nlmsg_type == NLMSG_DONE &&
+ filter.tb == RT_TABLE_MAIN &&
+ err == ENOENT)
+ return RTNL_SUPPRESS_NLMSG_DONE_NLERR;
+
+ return RTNL_LET_NLERR;
+}
+
static int iproute_list_flush_or_save(int argc, char **argv, int action)
{
int dump_family = preferred_family;
@@ -1939,7 +1951,8 @@ static int iproute_list_flush_or_save(int argc, char **argv, int action)
new_json_obj(json);
- if (rtnl_dump_filter(&rth, filter_fn, stdout) < 0) {
+ if (rtnl_dump_filter_errhndlr(&rth, filter_fn, stdout,
+ save_route_errhndlr, NULL) < 0) {
fprintf(stderr, "Dump terminated\n");
return -2;
}
diff --git a/lib/libnetlink.c b/lib/libnetlink.c
index c958aa57..e9b8c3bd 100644
--- a/lib/libnetlink.c
+++ b/lib/libnetlink.c
@@ -673,7 +673,8 @@ int rtnl_dump_request_n(struct rtnl_handle *rth, struct nlmsghdr *n)
return sendmsg(rth->fd, &msg, 0);
}
-static int rtnl_dump_done(struct nlmsghdr *h)
+static int rtnl_dump_done(struct nlmsghdr *h,
+ const struct rtnl_dump_filter_arg *a)
{
int len = *(int *)NLMSG_DATA(h);
@@ -683,11 +684,15 @@ static int rtnl_dump_done(struct nlmsghdr *h)
}
if (len < 0) {
+ errno = -len;
+
+ if (a->errhndlr(h, a->arg2) & RTNL_SUPPRESS_NLMSG_DONE_NLERR)
+ return 0;
+
/* check for any messages returned from kernel */
if (nl_dump_ext_ack_done(h, len))
return len;
- errno = -len;
switch (errno) {
case ENOENT:
case EOPNOTSUPP:
@@ -708,8 +713,9 @@ static int rtnl_dump_done(struct nlmsghdr *h)
return 0;
}
-static void rtnl_dump_error(const struct rtnl_handle *rth,
- struct nlmsghdr *h)
+static int rtnl_dump_error(const struct rtnl_handle *rth,
+ struct nlmsghdr *h,
+ const struct rtnl_dump_filter_arg *a)
{
if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) {
@@ -721,11 +727,16 @@ static void rtnl_dump_error(const struct rtnl_handle *rth,
if (rth->proto == NETLINK_SOCK_DIAG &&
(errno == ENOENT ||
errno == EOPNOTSUPP))
- return;
+ return -1;
+
+ if (a->errhndlr(h, a->arg2) & RTNL_SUPPRESS_NLMSG_ERROR_NLERR)
+ return 0;
if (!(rth->flags & RTNL_HANDLE_F_SUPPRESS_NLERR))
perror("RTNETLINK answers");
}
+
+ return -1;
}
static int __rtnl_recvmsg(int fd, struct msghdr *msg, int flags)
@@ -834,7 +845,7 @@ static int rtnl_dump_filter_l(struct rtnl_handle *rth,
dump_intr = 1;
if (h->nlmsg_type == NLMSG_DONE) {
- err = rtnl_dump_done(h);
+ err = rtnl_dump_done(h, a);
if (err < 0) {
free(buf);
return -1;
@@ -845,9 +856,13 @@ static int rtnl_dump_filter_l(struct rtnl_handle *rth,
}
if (h->nlmsg_type == NLMSG_ERROR) {
- rtnl_dump_error(rth, h);
- free(buf);
- return -1;
+ err = rtnl_dump_error(rth, h, a);
+ if (err < 0) {
+ free(buf);
+ return -1;
+ }
+
+ goto skip_it;
}
if (!rth->dump_fp) {
@@ -887,8 +902,25 @@ int rtnl_dump_filter_nc(struct rtnl_handle *rth,
void *arg1, __u16 nc_flags)
{
const struct rtnl_dump_filter_arg a[2] = {
- { .filter = filter, .arg1 = arg1, .nc_flags = nc_flags, },
- { .filter = NULL, .arg1 = NULL, .nc_flags = 0, },
+ { .filter = filter, .arg1 = arg1,
+ .errhndlr = NULL, .arg2 = NULL, .nc_flags = nc_flags, },
+ { },
+ };
+
+ return rtnl_dump_filter_l(rth, a);
+}
+
+int rtnl_dump_filter_errhndlr_nc(struct rtnl_handle *rth,
+ rtnl_filter_t filter,
+ void *arg1,
+ rtnl_err_hndlr_t errhndlr,
+ void *arg2,
+ __u16 nc_flags)
+{
+ const struct rtnl_dump_filter_arg a[2] = {
+ { .filter = filter, .arg1 = arg1,
+ .errhndlr = errhndlr, .arg2 = arg2, .nc_flags = nc_flags, },
+ { },
};
return rtnl_dump_filter_l(rth, a);
--
2.31.1
^ permalink raw reply related [flat|nested] 31+ messages in thread* Re: [PATCHv5 iproute2] ip route: ignore ENOENT during save if RT_TABLE_MAIN is being dumped
2021-07-07 12:22 ` Alexander Mikhalitsyn
@ 2021-07-07 14:35 ` Stephen Hemminger
2021-07-07 14:38 ` Alexander Mikhalitsyn
2021-07-07 14:50 ` patchwork-bot+netdevbpf
1 sibling, 1 reply; 31+ messages in thread
From: Stephen Hemminger @ 2021-07-07 14:35 UTC (permalink / raw)
To: Alexander Mikhalitsyn
Cc: netdev, David Ahern, Andrei Vagin, Alexander Mikhalitsyn
On Wed, 7 Jul 2021 15:22:01 +0300
Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
> We started to use in-kernel filtering feature which allows to get only
> needed tables (see iproute_dump_filter()). From the kernel side it's
> implemented in net/ipv4/fib_frontend.c (inet_dump_fib), net/ipv6/ip6_fib.c
> (inet6_dump_fib). The problem here is that behaviour of "ip route save"
> was changed after
> c7e6371bc ("ip route: Add protocol, table id and device to dump request").
> If filters are used, then kernel returns ENOENT error if requested table
> is absent, but in newly created net namespace even RT_TABLE_MAIN table
> doesn't exist. It is really allocated, for instance, after issuing
> "ip l set lo up".
>
> Reproducer is fairly simple:
> $ unshare -n ip route save > dump
> Error: ipv4: FIB table does not exist.
> Dump terminated
>
> Expected result here is to get empty dump file (as it was before this
> change).
>
> v2: reworked, so, now it takes into account NLMSGERR_ATTR_MSG
> (see nl_dump_ext_ack_done() function). We want to suppress error messages
> in stderr about absent FIB table from kernel too.
>
> v3: reworked to make code clearer. Introduced rtnl_suppressed_errors(),
> rtnl_suppress_error() helpers. User may suppress up to 3 errors (may be
> easily extended by changing SUPPRESS_ERRORS_INIT macro).
>
> v4: reworked, rtnl_dump_filter_errhndlr() was introduced. Thanks
> to Stephen Hemminger for comments and suggestions
>
> v5: space fixes, commit message reformat, empty initializers
>
> Fixes: c7e6371bc ("ip route: Add protocol, table id and device to dump request")
> Cc: David Ahern <dsahern@gmail.com>
> Cc: Stephen Hemminger <stephen@networkplumber.org>
> Cc: Andrei Vagin <avagin@gmail.com>
> Cc: Alexander Mikhalitsyn <alexander@mihalicyn.com>
> Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>
Applied this version
^ permalink raw reply [flat|nested] 31+ messages in thread* Re: [PATCHv5 iproute2] ip route: ignore ENOENT during save if RT_TABLE_MAIN is being dumped
2021-07-07 14:35 ` Stephen Hemminger
@ 2021-07-07 14:38 ` Alexander Mikhalitsyn
0 siblings, 0 replies; 31+ messages in thread
From: Alexander Mikhalitsyn @ 2021-07-07 14:38 UTC (permalink / raw)
To: Stephen Hemminger; +Cc: netdev, Alexander Mikhalitsyn
On Wed, 7 Jul 2021 07:35:05 -0700
Stephen Hemminger <stephen@networkplumber.org> wrote:
> On Wed, 7 Jul 2021 15:22:01 +0300
> Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> wrote:
>
> > We started to use in-kernel filtering feature which allows to get only
> > needed tables (see iproute_dump_filter()). From the kernel side it's
> > implemented in net/ipv4/fib_frontend.c (inet_dump_fib), net/ipv6/ip6_fib.c
> > (inet6_dump_fib). The problem here is that behaviour of "ip route save"
> > was changed after
> > c7e6371bc ("ip route: Add protocol, table id and device to dump request").
> > If filters are used, then kernel returns ENOENT error if requested table
> > is absent, but in newly created net namespace even RT_TABLE_MAIN table
> > doesn't exist. It is really allocated, for instance, after issuing
> > "ip l set lo up".
> >
> > Reproducer is fairly simple:
> > $ unshare -n ip route save > dump
> > Error: ipv4: FIB table does not exist.
> > Dump terminated
> >
> > Expected result here is to get empty dump file (as it was before this
> > change).
> >
> > v2: reworked, so, now it takes into account NLMSGERR_ATTR_MSG
> > (see nl_dump_ext_ack_done() function). We want to suppress error messages
> > in stderr about absent FIB table from kernel too.
> >
> > v3: reworked to make code clearer. Introduced rtnl_suppressed_errors(),
> > rtnl_suppress_error() helpers. User may suppress up to 3 errors (may be
> > easily extended by changing SUPPRESS_ERRORS_INIT macro).
> >
> > v4: reworked, rtnl_dump_filter_errhndlr() was introduced. Thanks
> > to Stephen Hemminger for comments and suggestions
> >
> > v5: space fixes, commit message reformat, empty initializers
> >
> > Fixes: c7e6371bc ("ip route: Add protocol, table id and device to dump request")
> > Cc: David Ahern <dsahern@gmail.com>
> > Cc: Stephen Hemminger <stephen@networkplumber.org>
> > Cc: Andrei Vagin <avagin@gmail.com>
> > Cc: Alexander Mikhalitsyn <alexander@mihalicyn.com>
> > Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>
>
> Applied this version
Stephen,
Thank you for your review and suggestions!
Alex
^ permalink raw reply [flat|nested] 31+ messages in thread
* Re: [PATCHv5 iproute2] ip route: ignore ENOENT during save if RT_TABLE_MAIN is being dumped
2021-07-07 12:22 ` Alexander Mikhalitsyn
2021-07-07 14:35 ` Stephen Hemminger
@ 2021-07-07 14:50 ` patchwork-bot+netdevbpf
2021-07-11 10:59 ` Roi Dayan
1 sibling, 1 reply; 31+ messages in thread
From: patchwork-bot+netdevbpf @ 2021-07-07 14:50 UTC (permalink / raw)
To: Alexander Mikhalitsyn; +Cc: netdev, dsahern, stephen, avagin, alexander
Hello:
This patch was applied to iproute2/iproute2.git (refs/heads/main):
On Wed, 7 Jul 2021 15:22:01 +0300 you wrote:
> We started to use in-kernel filtering feature which allows to get only
> needed tables (see iproute_dump_filter()). From the kernel side it's
> implemented in net/ipv4/fib_frontend.c (inet_dump_fib), net/ipv6/ip6_fib.c
> (inet6_dump_fib). The problem here is that behaviour of "ip route save"
> was changed after
> c7e6371bc ("ip route: Add protocol, table id and device to dump request").
> If filters are used, then kernel returns ENOENT error if requested table
> is absent, but in newly created net namespace even RT_TABLE_MAIN table
> doesn't exist. It is really allocated, for instance, after issuing
> "ip l set lo up".
>
> [...]
Here is the summary with links:
- [PATCHv5,iproute2] ip route: ignore ENOENT during save if RT_TABLE_MAIN is being dumped
https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/commit/?id=459ce6e3d792
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
^ permalink raw reply [flat|nested] 31+ messages in thread* Re: [PATCHv5 iproute2] ip route: ignore ENOENT during save if RT_TABLE_MAIN is being dumped
2021-07-07 14:50 ` patchwork-bot+netdevbpf
@ 2021-07-11 10:59 ` Roi Dayan
2021-07-11 11:09 ` Roi Dayan
0 siblings, 1 reply; 31+ messages in thread
From: Roi Dayan @ 2021-07-11 10:59 UTC (permalink / raw)
To: patchwork-bot+netdevbpf, Alexander Mikhalitsyn
Cc: netdev, dsahern, stephen, avagin, alexander
On 2021-07-07 5:50 PM, patchwork-bot+netdevbpf@kernel.org wrote:
> Hello:
>
> This patch was applied to iproute2/iproute2.git (refs/heads/main):
>
> On Wed, 7 Jul 2021 15:22:01 +0300 you wrote:
>> We started to use in-kernel filtering feature which allows to get only
>> needed tables (see iproute_dump_filter()). From the kernel side it's
>> implemented in net/ipv4/fib_frontend.c (inet_dump_fib), net/ipv6/ip6_fib.c
>> (inet6_dump_fib). The problem here is that behaviour of "ip route save"
>> was changed after
>> c7e6371bc ("ip route: Add protocol, table id and device to dump request").
>> If filters are used, then kernel returns ENOENT error if requested table
>> is absent, but in newly created net namespace even RT_TABLE_MAIN table
>> doesn't exist. It is really allocated, for instance, after issuing
>> "ip l set lo up".
>>
>> [...]
>
> Here is the summary with links:
> - [PATCHv5,iproute2] ip route: ignore ENOENT during save if RT_TABLE_MAIN is being dumped
> https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/commit/?id=459ce6e3d792
>
> You are awesome, thank you!
> --
> Deet-doot-dot, I am a bot.
> https://korg.docs.kernel.org/patchwork/pwbot.html
>
>
Hi,
I didn't get a chance to check but after this commit the utility ss
is crashing from libnetlink.c
(gdb) bt
#0 0x0000000000000000 in ?? ()
#1 0x0000000000418980 in rtnl_dump_done (a=0x7fffffffdc00, h=0x449c80)
at libnetlink.c:734
#2 rtnl_dump_filter_l (rth=rth@entry=0x7fffffffdcf0,
arg=arg@entry=0x7fffffffdc00) at libnetlink.c:893
#3 0x00000000004197a2 in rtnl_dump_filter_nc
(rth=rth@entry=0x7fffffffdcf0, filter=filter@entry=0x40cdf0
<show_one_inet_sock>,
arg1=arg1@entry=0x7fffffffdca0, nc_flags=nc_flags@entry=0) at
libnetlink.c:957
#4 0x0000000000406dc7 in inet_show_netlink (dump_fp=dump_fp@entry=0x0,
protocol=protocol@entry=255, f=0x42e900 <current_filter>) at ss.c:3638
#5 0x0000000000404db3 in raw_show (f=0x42e900 <current_filter>) at
ss.c:3939
if I revert this commit I can run the ss utility ok.
Thanks,
Roi
^ permalink raw reply [flat|nested] 31+ messages in thread* Re: [PATCHv5 iproute2] ip route: ignore ENOENT during save if RT_TABLE_MAIN is being dumped
2021-07-11 10:59 ` Roi Dayan
@ 2021-07-11 11:09 ` Roi Dayan
2021-07-11 11:12 ` Alexander Mihalicyn
0 siblings, 1 reply; 31+ messages in thread
From: Roi Dayan @ 2021-07-11 11:09 UTC (permalink / raw)
To: patchwork-bot+netdevbpf, Alexander Mikhalitsyn
Cc: netdev, dsahern, stephen, avagin, alexander
On 2021-07-11 1:59 PM, Roi Dayan wrote:
>
>
> On 2021-07-07 5:50 PM, patchwork-bot+netdevbpf@kernel.org wrote:
>> Hello:
>>
>> This patch was applied to iproute2/iproute2.git (refs/heads/main):
>>
>> On Wed, 7 Jul 2021 15:22:01 +0300 you wrote:
>>> We started to use in-kernel filtering feature which allows to get only
>>> needed tables (see iproute_dump_filter()). From the kernel side it's
>>> implemented in net/ipv4/fib_frontend.c (inet_dump_fib),
>>> net/ipv6/ip6_fib.c
>>> (inet6_dump_fib). The problem here is that behaviour of "ip route save"
>>> was changed after
>>> c7e6371bc ("ip route: Add protocol, table id and device to dump
>>> request").
>>> If filters are used, then kernel returns ENOENT error if requested table
>>> is absent, but in newly created net namespace even RT_TABLE_MAIN table
>>> doesn't exist. It is really allocated, for instance, after issuing
>>> "ip l set lo up".
>>>
>>> [...]
>>
>> Here is the summary with links:
>> - [PATCHv5,iproute2] ip route: ignore ENOENT during save if
>> RT_TABLE_MAIN is being dumped
>>
>> https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/commit/?id=459ce6e3d792
>>
>>
>> You are awesome, thank you!
>> --
>> Deet-doot-dot, I am a bot.
>> https://korg.docs.kernel.org/patchwork/pwbot.html
>>
>>
>
>
> Hi,
>
> I didn't get a chance to check but after this commit the utility ss
> is crashing from libnetlink.c
>
> (gdb) bt
> #0 0x0000000000000000 in ?? ()
> #1 0x0000000000418980 in rtnl_dump_done (a=0x7fffffffdc00, h=0x449c80)
> at libnetlink.c:734
> #2 rtnl_dump_filter_l (rth=rth@entry=0x7fffffffdcf0,
> arg=arg@entry=0x7fffffffdc00) at libnetlink.c:893
> #3 0x00000000004197a2 in rtnl_dump_filter_nc
> (rth=rth@entry=0x7fffffffdcf0, filter=filter@entry=0x40cdf0
> <show_one_inet_sock>,
> arg1=arg1@entry=0x7fffffffdca0, nc_flags=nc_flags@entry=0) at
> libnetlink.c:957
> #4 0x0000000000406dc7 in inet_show_netlink (dump_fp=dump_fp@entry=0x0,
> protocol=protocol@entry=255, f=0x42e900 <current_filter>) at ss.c:3638
> #5 0x0000000000404db3 in raw_show (f=0x42e900 <current_filter>) at
> ss.c:3939
>
>
> if I revert this commit I can run the ss utility ok.
>
> Thanks,
> Roi
I found for me ss crashed using a->errhndlr but it could be null
in rtnl_dump_done()
I see a second usage of a->errhndlr in rtnl_dump_error()
^ permalink raw reply [flat|nested] 31+ messages in thread* Re: [PATCHv5 iproute2] ip route: ignore ENOENT during save if RT_TABLE_MAIN is being dumped
2021-07-11 11:09 ` Roi Dayan
@ 2021-07-11 11:12 ` Alexander Mihalicyn
0 siblings, 0 replies; 31+ messages in thread
From: Alexander Mihalicyn @ 2021-07-11 11:12 UTC (permalink / raw)
To: Roi Dayan; +Cc: patchwork-bot+netdevbpf, netdev, dsahern, stephen
Thanks, Roi.
I will send a patch soon.
On Sun, Jul 11, 2021 at 2:09 PM Roi Dayan <roid@nvidia.com> wrote:
>
>
>
> On 2021-07-11 1:59 PM, Roi Dayan wrote:
> >
> >
> > On 2021-07-07 5:50 PM, patchwork-bot+netdevbpf@kernel.org wrote:
> >> Hello:
> >>
> >> This patch was applied to iproute2/iproute2.git (refs/heads/main):
> >>
> >> On Wed, 7 Jul 2021 15:22:01 +0300 you wrote:
> >>> We started to use in-kernel filtering feature which allows to get only
> >>> needed tables (see iproute_dump_filter()). From the kernel side it's
> >>> implemented in net/ipv4/fib_frontend.c (inet_dump_fib),
> >>> net/ipv6/ip6_fib.c
> >>> (inet6_dump_fib). The problem here is that behaviour of "ip route save"
> >>> was changed after
> >>> c7e6371bc ("ip route: Add protocol, table id and device to dump
> >>> request").
> >>> If filters are used, then kernel returns ENOENT error if requested table
> >>> is absent, but in newly created net namespace even RT_TABLE_MAIN table
> >>> doesn't exist. It is really allocated, for instance, after issuing
> >>> "ip l set lo up".
> >>>
> >>> [...]
> >>
> >> Here is the summary with links:
> >> - [PATCHv5,iproute2] ip route: ignore ENOENT during save if
> >> RT_TABLE_MAIN is being dumped
> >>
> >> https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/commit/?id=459ce6e3d792
> >>
> >>
> >> You are awesome, thank you!
> >> --
> >> Deet-doot-dot, I am a bot.
> >> https://korg.docs.kernel.org/patchwork/pwbot.html
> >>
> >>
> >
> >
> > Hi,
> >
> > I didn't get a chance to check but after this commit the utility ss
> > is crashing from libnetlink.c
> >
> > (gdb) bt
> > #0 0x0000000000000000 in ?? ()
> > #1 0x0000000000418980 in rtnl_dump_done (a=0x7fffffffdc00, h=0x449c80)
> > at libnetlink.c:734
> > #2 rtnl_dump_filter_l (rth=rth@entry=0x7fffffffdcf0,
> > arg=arg@entry=0x7fffffffdc00) at libnetlink.c:893
> > #3 0x00000000004197a2 in rtnl_dump_filter_nc
> > (rth=rth@entry=0x7fffffffdcf0, filter=filter@entry=0x40cdf0
> > <show_one_inet_sock>,
> > arg1=arg1@entry=0x7fffffffdca0, nc_flags=nc_flags@entry=0) at
> > libnetlink.c:957
> > #4 0x0000000000406dc7 in inet_show_netlink (dump_fp=dump_fp@entry=0x0,
> > protocol=protocol@entry=255, f=0x42e900 <current_filter>) at ss.c:3638
> > #5 0x0000000000404db3 in raw_show (f=0x42e900 <current_filter>) at
> > ss.c:3939
> >
> >
> > if I revert this commit I can run the ss utility ok.
> >
> > Thanks,
> > Roi
>
> I found for me ss crashed using a->errhndlr but it could be null
> in rtnl_dump_done()
>
> I see a second usage of a->errhndlr in rtnl_dump_error()
>
>
^ permalink raw reply [flat|nested] 31+ messages in thread