* ebtables behaving weirdly on MIPS platform
@ 2021-09-30 6:23 Senthil Kumar Balasubramanian
2021-09-30 10:38 ` Phil Sutter
0 siblings, 1 reply; 5+ messages in thread
From: Senthil Kumar Balasubramanian @ 2021-09-30 6:23 UTC (permalink / raw)
To: netfilter-devel; +Cc: pablo
We are running OpenWRT/Tp-Link Archer A6 HW v2... (openwrt : 21.02
ebtables v2.0.10-4)
and when we run this ebtables with nflog extension as mentioned below
ebtables -I FORWARD -o eth1 -p ip --ip-protocol udp --ip-source-port
68 --nflog-group 1 --nflog-prefix "ENTRY1" -j ACCEPT
, we are running into the following issues..
Unable to update the kernel. Two possible causes:
1. Multiple ebtables programs were executing simultaneously. The ebtables
userspace tool doesn't by default support multiple ebtables programs running
concurrently. The ebtables option --concurrent or a tool like flock can be
used to support concurrent scripts that update the ebtables kernel tables.
2. The kernel doesn't support a certain ebtables extension, consider
recompiling your kernel or insmod the extension.
We have confirmed the required kernel configs are enabled and ensured
the same with a ARM platform where the same command works..
However, dumping the data that goes to the kernel, we see a huge
difference between MIPS and ARM..
in ARM platform
w_l->w:
0000 6e 66 6c 6f 67 00 ff b6 00 00 00 00 00 00 00 00 nflog...........
0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0020 50 00 00 00 00 00 00 00 01 00 01 00 00 00 00 00 P...............
0030 45 4e 54 52 59 31 00 00 00 00 00 00 00 00 00 00 ENTRY1..........
0040 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0050 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0060 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0070 00 00 00 00
in tplink a6 (MIPS platform)
w_l->w:
0000 6e 66 6c 6f 67 00 b2 e0 69 6d 69 74 20 65 78 63 nflog...imit exc
0010 65 65 64 65 64 00 56 69 72 74 75 61 6c 20 74 69 eeded.Virtual ti
0020 00 00 00 50 65 78 70 69 00 01 00 01 50 72 6f 66 ...Pexpi....Prof
0030 45 4e 54 52 59 31 00 69 6d 65 72 20 65 78 70 69 ENTRY1.imer expi
0040 72 65 64 00 57 69 6e 64 6f 77 20 63 68 61 6e 67 red.Window chang
0050 65 64 00 49 2f 4f 20 70 6f 73 73 69 62 6c 65 00 ed.I/O possible.
0060 50 6f 77 65 72 20 66 61 69 6c 75 72 65 00 42 61 Power failure.Ba
0070 64 20 73 79
d sy
Can you please let me know what's going wrong with this?
Thanks
Senthil
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: ebtables behaving weirdly on MIPS platform
2021-09-30 6:23 ebtables behaving weirdly on MIPS platform Senthil Kumar Balasubramanian
@ 2021-09-30 10:38 ` Phil Sutter
2021-09-30 10:52 ` Florian Westphal
0 siblings, 1 reply; 5+ messages in thread
From: Phil Sutter @ 2021-09-30 10:38 UTC (permalink / raw)
To: Senthil Kumar Balasubramanian; +Cc: netfilter-devel, pablo
Hi,
On Thu, Sep 30, 2021 at 11:53:32AM +0530, Senthil Kumar Balasubramanian wrote:
> We are running OpenWRT/Tp-Link Archer A6 HW v2... (openwrt : 21.02
> ebtables v2.0.10-4)
>
> and when we run this ebtables with nflog extension as mentioned below
>
> ebtables -I FORWARD -o eth1 -p ip --ip-protocol udp --ip-source-port
> 68 --nflog-group 1 --nflog-prefix "ENTRY1" -j ACCEPT
>
> , we are running into the following issues..
>
> Unable to update the kernel. Two possible causes:
> 1. Multiple ebtables programs were executing simultaneously. The ebtables
> userspace tool doesn't by default support multiple ebtables programs running
> concurrently. The ebtables option --concurrent or a tool like flock can be
> used to support concurrent scripts that update the ebtables kernel tables.
> 2. The kernel doesn't support a certain ebtables extension, consider
> recompiling your kernel or insmod the extension.
>
> We have confirmed the required kernel configs are enabled and ensured
> the same with a ARM platform where the same command works..
>
> However, dumping the data that goes to the kernel, we see a huge
> difference between MIPS and ARM..
>
> in ARM platform
> w_l->w:
> 0000 6e 66 6c 6f 67 00 ff b6 00 00 00 00 00 00 00 00 nflog...........
> 0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> 0020 50 00 00 00 00 00 00 00 01 00 01 00 00 00 00 00 P...............
> 0030 45 4e 54 52 59 31 00 00 00 00 00 00 00 00 00 00 ENTRY1..........
> 0040 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> 0050 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> 0060 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> 0070 00 00 00 00
>
> in tplink a6 (MIPS platform)
>
> w_l->w:
> 0000 6e 66 6c 6f 67 00 b2 e0 69 6d 69 74 20 65 78 63 nflog...imit exc
> 0010 65 65 64 65 64 00 56 69 72 74 75 61 6c 20 74 69 eeded.Virtual ti
> 0020 00 00 00 50 65 78 70 69 00 01 00 01 50 72 6f 66 ...Pexpi....Prof
> 0030 45 4e 54 52 59 31 00 69 6d 65 72 20 65 78 70 69 ENTRY1.imer expi
> 0040 72 65 64 00 57 69 6e 64 6f 77 20 63 68 61 6e 67 red.Window chang
> 0050 65 64 00 49 2f 4f 20 70 6f 73 73 69 62 6c 65 00 ed.I/O possible.
> 0060 50 6f 77 65 72 20 66 61 69 6c 75 72 65 00 42 61 Power failure.Ba
> 0070 64 20 73 79
> d sy
>
> Can you please let me know what's going wrong with this?
Looks like the data structure contains garbage. Looking at ebtables
code, that seems likely as extension data structures are allocated using
malloc() and never set zero. init() function in ebt_nflog.c only
initializes prefix, group and threshold fields (which seem to be set
correctly in your MIPS dump).
I wonder how this is supposed to work, I can't find a place which zeroes
relevant data. It looks like we're missing memset() calls in
ebt_register_{match,watcher,target} functions. OTOH this seems to work
fine in most cases, so I'm likely missing something.
Cheers, Phil
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: ebtables behaving weirdly on MIPS platform
2021-09-30 10:38 ` Phil Sutter
@ 2021-09-30 10:52 ` Florian Westphal
2021-09-30 12:47 ` Senthil Kumar Balasubramanian
0 siblings, 1 reply; 5+ messages in thread
From: Florian Westphal @ 2021-09-30 10:52 UTC (permalink / raw)
To: Phil Sutter, Senthil Kumar Balasubramanian, netfilter-devel, pablo
Phil Sutter <phil@nwl.cc> wrote:
> On Thu, Sep 30, 2021 at 11:53:32AM +0530, Senthil Kumar Balasubramanian wrote:
> > However, dumping the data that goes to the kernel, we see a huge
> > difference between MIPS and ARM..
> >
> > in ARM platform
> > w_l->w:
> > 0000 6e 66 6c 6f 67 00 ff b6 00 00 00 00 00 00 00 00 nflog...........
> > 0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> > 0020 50 00 00 00 00 00 00 00 01 00 01 00 00 00 00 00 P...............
> > 0030 45 4e 54 52 59 31 00 00 00 00 00 00 00 00 00 00 ENTRY1..........
> > 0040 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> > 0050 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> > 0060 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> > 0070 00 00 00 00
> >
> > in tplink a6 (MIPS platform)
> >
> > w_l->w:
> > 0000 6e 66 6c 6f 67 00 b2 e0 69 6d 69 74 20 65 78 63 nflog...imit exc
> > 0010 65 65 64 65 64 00 56 69 72 74 75 61 6c 20 74 69 eeded.Virtual ti
> > 0020 00 00 00 50 65 78 70 69 00 01 00 01 50 72 6f 66 ...Pexpi....Prof
> > 0030 45 4e 54 52 59 31 00 69 6d 65 72 20 65 78 70 69 ENTRY1.imer expi
> > 0040 72 65 64 00 57 69 6e 64 6f 77 20 63 68 61 6e 67 red.Window chang
> > 0050 65 64 00 49 2f 4f 20 70 6f 73 73 69 62 6c 65 00 ed.I/O possible.
> > 0060 50 6f 77 65 72 20 66 61 69 6c 75 72 65 00 42 61 Power failure.Ba
> > 0070 64 20 73 79
> > d sy
> >
> > Can you please let me know what's going wrong with this?
>
> Looks like the data structure contains garbage. Looking at ebtables
> code, that seems likely as extension data structures are allocated using
> malloc() and never set zero. init() function in ebt_nflog.c only
> initializes prefix, group and threshold fields (which seem to be set
> correctly in your MIPS dump).
Yes, probably pure luck (libc differences and the like).
Senthil, can you try this patch (compile tested only)?
diff --git a/libebtc.c b/libebtc.c
--- a/libebtc.c
+++ b/libebtc.c
@@ -41,6 +41,18 @@
static void decrease_chain_jumps(struct ebt_u_replace *replace);
static int iterate_entries(struct ebt_u_replace *replace, int type);
+static void *xzalloc(size_t s)
+{
+ void *p = malloc(s);
+
+ if (!p)
+ ebt_print_memory();
+
+ memset(p, 0, s);
+
+ return p;
+}
+
/* The standard names */
const char *ebt_hooknames[NF_BR_NUMHOOKS] =
{
@@ -266,9 +278,7 @@ void ebt_reinit_extensions()
for (m = ebt_matches; m; m = m->next) {
if (m->used) {
size = EBT_ALIGN(m->size) + sizeof(struct ebt_entry_match);
- m->m = (struct ebt_entry_match *)malloc(size);
- if (!m->m)
- ebt_print_memory();
+ m->m = xzalloc(size);
strcpy(m->m->u.name, m->name);
m->m->u.revision = m->revision;
m->m->match_size = EBT_ALIGN(m->size);
@@ -280,9 +290,7 @@ void ebt_reinit_extensions()
for (w = ebt_watchers; w; w = w->next) {
if (w->used) {
size = EBT_ALIGN(w->size) + sizeof(struct ebt_entry_watcher);
- w->w = (struct ebt_entry_watcher *)malloc(size);
- if (!w->w)
- ebt_print_memory();
+ w->w = xzalloc(size);
strcpy(w->w->u.name, w->name);
w->w->watcher_size = EBT_ALIGN(w->size);
w->used = 0;
@@ -293,9 +301,7 @@ void ebt_reinit_extensions()
for (t = ebt_targets; t; t = t->next) {
if (t->used) {
size = EBT_ALIGN(t->size) + sizeof(struct ebt_entry_target);
- t->t = (struct ebt_entry_target *)malloc(size);
- if (!t->t)
- ebt_print_memory();
+ t->t = xzalloc(size);
strcpy(t->t->u.name, t->name);
t->t->target_size = EBT_ALIGN(t->size);
t->used = 0;
@@ -645,9 +651,7 @@ void ebt_add_rule(struct ebt_u_replace *replace, struct ebt_u_entry *new_entry,
new_entry->prev = u_e->prev;
u_e->prev->next = new_entry;
u_e->prev = new_entry;
- new_cc = (struct ebt_cntchanges *)malloc(sizeof(struct ebt_cntchanges));
- if (!new_cc)
- ebt_print_memory();
+ new_cc = xzalloc(sizeof(struct ebt_cntchanges));
new_cc->type = CNT_ADD;
new_cc->change = 0;
if (new_entry->next == entries->entries) {
@@ -861,18 +865,14 @@ void ebt_new_chain(struct ebt_u_replace *replace, const char *name, int policy)
if (replace->num_chains == replace->max_chains)
ebt_double_chains(replace);
- new = (struct ebt_u_entries *)malloc(sizeof(struct ebt_u_entries));
- if (!new)
- ebt_print_memory();
+ new = xzalloc(sizeof(struct ebt_u_entries));
replace->chains[replace->num_chains++] = new;
new->nentries = 0;
new->policy = policy;
new->counter_offset = replace->nentries;
new->hook_mask = 0;
strcpy(new->name, name);
- new->entries = (struct ebt_u_entry *)malloc(sizeof(struct ebt_u_entry));
- if (!new->entries)
- ebt_print_memory();
+ new->entries = xzalloc(sizeof(struct ebt_u_entry));
new->entries->next = new->entries->prev = new->entries;
new->kernel_start = NULL;
}
@@ -1041,7 +1041,7 @@ void ebt_check_for_loops(struct ebt_u_replace *replace)
}
if (replace->num_chains == NF_BR_NUMHOOKS)
return;
- stack = (struct ebt_u_stack *)malloc((replace->num_chains - NF_BR_NUMHOOKS) * sizeof(struct ebt_u_stack));
+ stack = calloc((replace->num_chains - NF_BR_NUMHOOKS), sizeof(struct ebt_u_stack));
if (!stack)
ebt_print_memory();
@@ -1111,10 +1111,7 @@ void ebt_add_match(struct ebt_u_entry *new_entry, struct ebt_u_match *m)
struct ebt_u_match_list **m_list, *new;
for (m_list = &new_entry->m_list; *m_list; m_list = &(*m_list)->next);
- new = (struct ebt_u_match_list *)
- malloc(sizeof(struct ebt_u_match_list));
- if (!new)
- ebt_print_memory();
+ new = xzalloc(sizeof(struct ebt_u_match_list));
*m_list = new;
new->next = NULL;
new->m = (struct ebt_entry_match *)m;
@@ -1126,10 +1123,7 @@ void ebt_add_watcher(struct ebt_u_entry *new_entry, struct ebt_u_watcher *w)
struct ebt_u_watcher_list *new;
for (w_list = &new_entry->w_list; *w_list; w_list = &(*w_list)->next);
- new = (struct ebt_u_watcher_list *)
- malloc(sizeof(struct ebt_u_watcher_list));
- if (!new)
- ebt_print_memory();
+ new = xzalloc(sizeof(struct ebt_u_watcher_list));
*w_list = new;
new->next = NULL;
new->w = (struct ebt_entry_watcher *)w;
@@ -1206,9 +1200,7 @@ void ebt_register_match(struct ebt_u_match *m)
int size = EBT_ALIGN(m->size) + sizeof(struct ebt_entry_match);
struct ebt_u_match **i;
- m->m = (struct ebt_entry_match *)malloc(size);
- if (!m->m)
- ebt_print_memory();
+ m->m = xzalloc(size);
strcpy(m->m->u.name, m->name);
m->m->u.revision = m->revision;
m->m->match_size = EBT_ALIGN(m->size);
@@ -1224,9 +1216,7 @@ void ebt_register_watcher(struct ebt_u_watcher *w)
int size = EBT_ALIGN(w->size) + sizeof(struct ebt_entry_watcher);
struct ebt_u_watcher **i;
- w->w = (struct ebt_entry_watcher *)malloc(size);
- if (!w->w)
- ebt_print_memory();
+ w->w = xzalloc(size);
strcpy(w->w->u.name, w->name);
w->w->watcher_size = EBT_ALIGN(w->size);
w->init(w->w);
@@ -1241,9 +1231,7 @@ void ebt_register_target(struct ebt_u_target *t)
int size = EBT_ALIGN(t->size) + sizeof(struct ebt_entry_target);
struct ebt_u_target **i;
- t->t = (struct ebt_entry_target *)malloc(size);
- if (!t->t)
- ebt_print_memory();
+ t->t = xzalloc(size);
strcpy(t->t->u.name, t->name);
t->t->target_size = EBT_ALIGN(t->size);
t->init(t->t);
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: ebtables behaving weirdly on MIPS platform
2021-09-30 10:52 ` Florian Westphal
@ 2021-09-30 12:47 ` Senthil Kumar Balasubramanian
2021-09-30 13:02 ` Florian Westphal
0 siblings, 1 reply; 5+ messages in thread
From: Senthil Kumar Balasubramanian @ 2021-09-30 12:47 UTC (permalink / raw)
To: Florian Westphal; +Cc: Phil Sutter, netfilter-devel, pablo
On Thu, Sep 30, 2021 at 12:52:23PM +0200, Florian Westphal wrote:
> Phil Sutter <phil@nwl.cc> wrote:
> > On Thu, Sep 30, 2021 at 11:53:32AM +0530, Senthil Kumar Balasubramanian wrote:
> > > However, dumping the data that goes to the kernel, we see a huge
> > > difference between MIPS and ARM..
> > >
> > > in ARM platform
> > > w_l->w:
> > > 0000 6e 66 6c 6f 67 00 ff b6 00 00 00 00 00 00 00 00 nflog...........
> > > 0010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> > > 0020 50 00 00 00 00 00 00 00 01 00 01 00 00 00 00 00 P...............
> > > 0030 45 4e 54 52 59 31 00 00 00 00 00 00 00 00 00 00 ENTRY1..........
> > > 0040 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> > > 0050 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> > > 0060 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> > > 0070 00 00 00 00
> > >
> > > in tplink a6 (MIPS platform)
> > >
> > > w_l->w:
> > > 0000 6e 66 6c 6f 67 00 b2 e0 69 6d 69 74 20 65 78 63 nflog...imit exc
> > > 0010 65 65 64 65 64 00 56 69 72 74 75 61 6c 20 74 69 eeded.Virtual ti
> > > 0020 00 00 00 50 65 78 70 69 00 01 00 01 50 72 6f 66 ...Pexpi....Prof
> > > 0030 45 4e 54 52 59 31 00 69 6d 65 72 20 65 78 70 69 ENTRY1.imer expi
> > > 0040 72 65 64 00 57 69 6e 64 6f 77 20 63 68 61 6e 67 red.Window chang
> > > 0050 65 64 00 49 2f 4f 20 70 6f 73 73 69 62 6c 65 00 ed.I/O possible.
> > > 0060 50 6f 77 65 72 20 66 61 69 6c 75 72 65 00 42 61 Power failure.Ba
> > > 0070 64 20 73 79
> > > d sy
> > >
> > > Can you please let me know what's going wrong with this?
> >
> > Looks like the data structure contains garbage. Looking at ebtables
> > code, that seems likely as extension data structures are allocated using
> > malloc() and never set zero. init() function in ebt_nflog.c only
> > initializes prefix, group and threshold fields (which seem to be set
> > correctly in your MIPS dump).
>
> Yes, probably pure luck (libc differences and the like).
>
> Senthil, can you try this patch (compile tested only)?
Yes. this patch work... Good and quick catch..
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: ebtables behaving weirdly on MIPS platform
2021-09-30 12:47 ` Senthil Kumar Balasubramanian
@ 2021-09-30 13:02 ` Florian Westphal
0 siblings, 0 replies; 5+ messages in thread
From: Florian Westphal @ 2021-09-30 13:02 UTC (permalink / raw)
To: Senthil Kumar Balasubramanian
Cc: Florian Westphal, Phil Sutter, netfilter-devel, pablo
Senthil Kumar Balasubramanian <senthilb@qubercomm.com> wrote:
> Yes. this patch work... Good and quick catch..
Thanks, I pushed this patch to ebtables.git.
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2021-09-30 13:02 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2021-09-30 6:23 ebtables behaving weirdly on MIPS platform Senthil Kumar Balasubramanian
2021-09-30 10:38 ` Phil Sutter
2021-09-30 10:52 ` Florian Westphal
2021-09-30 12:47 ` Senthil Kumar Balasubramanian
2021-09-30 13:02 ` Florian Westphal
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