[PATCH nft] meta: fix error checks in tc handle parser

[PATCH nft] meta: fix error checks in tc handle parser

[Florian Westphal]

'meta priority foobar' did not return an error -- instead
we used min/max values with undefined content.

Signed-off-by: Florian Westphal <fw@strlen.de>
---
 src/meta.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/meta.c b/src/meta.c
index 8cbc974..7f12f0c 100644
--- a/src/meta.c
+++ b/src/meta.c
@@ -100,17 +100,17 @@ static struct error_record *tchandle_type_parse(const struct expr *sym,
 	else if (strcmp(sym->identifier, "none") == 0)
 		handle = TC_H_UNSPEC;
 	else if (sym->identifier[0] == ':') {
-		if (sscanf(sym->identifier, ":%04x", &handle) < 0)
+		if (sscanf(sym->identifier, ":%04x", &handle) != 1)
 			goto err;
 	} else if (sym->identifier[strlen(sym->identifier)-1] == ':') {
-		if (sscanf(sym->identifier, "%04x:", &handle) < 0)
+		if (sscanf(sym->identifier, "%04x:", &handle) != 1)
 			goto err;
 
 		handle <<= 16;
 	} else {
 		uint32_t min, max;
 
-		if (sscanf(sym->identifier, "%04x:%04x", &min, &max) < 0)
+		if (sscanf(sym->identifier, "%04x:%04x", &min, &max) != 2)
 			goto err;
 
 		handle = max << 16 | min;
-- 
2.4.10

Re: [PATCH nft] meta: fix error checks in tc handle parser

[Pablo Neira Ayuso]

On Mon, Feb 01, 2016 at 12:02:36PM +0100, Florian Westphal wrote:
> 'meta priority foobar' did not return an error -- instead
> we used min/max values with undefined content.
> 
> Signed-off-by: Florian Westphal <fw@strlen.de>

Fine with me. IIRC, the scanner is still broken though.

Re: [PATCH nft] meta: fix error checks in tc handle parser

[Florian Westphal]

Pablo Neira Ayuso <pablo@netfilter.org> wrote:
> On Mon, Feb 01, 2016 at 12:02:36PM +0100, Florian Westphal wrote:
> > 'meta priority foobar' did not return an error -- instead
> > we used min/max values with undefined content.
> > 
> > Signed-off-by: Florian Westphal <fw@strlen.de>
> 
> Fine with me. IIRC, the scanner is still broken though.

Ho-hum.  It is.  And I don't see how this can be fixed.
Teaching scanner.l about

tchandle       {hexdigit}{4}:{hexdigit}{4}

breaks

tcp sport vmap { 1225:accept, }

( 1225:acc is handle).

Re: [PATCH nft] meta: fix error checks in tc handle parser

[Pablo Neira Ayuso]

On Mon, Feb 01, 2016 at 12:02:36PM +0100, Florian Westphal wrote:
> 'meta priority foobar' did not return an error -- instead
> we used min/max values with undefined content.
> 
> Signed-off-by: Florian Westphal <fw@strlen.de>

Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>

I know this is still not the full fix for this, but I would like to
make sure this doesn't get lost, so go push it. Thanks.