* libnetfilter_queue & multithreading
@ 2017-07-22 13:08 Oleg
2017-07-22 16:38 ` Florian Westphal
0 siblings, 1 reply; 5+ messages in thread
From: Oleg @ 2017-07-22 13:08 UTC (permalink / raw)
To: netfilter-devel
Hi, all.
My program process multiple NFQUEUEs by creating a separate thread
for every NFQUEUE. An each thread do recv() and nfq_set_verdict2():
main()
{
...
for(i = 0; i < q_cnt; i++) {
ret = pthread_create(&(thread_data[i].id), NULL, thread_start,
&thread_data[i].nfq_num);
if (ret != 0) {
fprintf(stderr, "thread creation error: %s", strerror(ret));
exit(EXIT_FAILURE);
}
}
...
}
static void*
thread_start(void *data)
{
struct nfq_handle *h;
int fd, n;
static char *pkt_buf;
unsigned int nfq_num = *(unsigned int*)data;
pkt_buf = (char*)malloc(80000);
if (!pkt_buf) {
fprintf(stderr, "packet buffer allocating error: no memory");
exit(EXIT_FAILURE);
}
h = init_nfq(nfq_num);
fd = nfq_fd(h);
while ((n = recv(fd, pkt_buf, 80000, 0)) > 0) {
nfq_handle_packet(h, pkt_buf, n);
}
...
}
static struct nfq_handle*
init_nfq(unsigned int nfq_num)
{
struct nfq_handle *h;
struct nfq_q_handle *qh;
h = nfq_open();
if (!h) {
fprintf(stderr, "nfq error: queue %d nfq_open() error", nfq_num);
exit(EXIT_FAILURE);
}
if (nfq_unbind_pf(h, AF_INET) < 0) {
fprintf(stderr, "nfq error: queue %d nfq_bind_pf() error", nfq_num);
exit(EXIT_FAILURE);
}
if (nfq_bind_pf(h, AF_INET) < 0) {
fprintf(stderr, "nfq error: queue %d nfq_bind_pf() error", nfq_num);
exit(EXIT_FAILURE);
}
qh = nfq_create_queue(h, nfq_num, &cb, NULL);
if (!qh) {
fprintf(stderr, "nfq error: queue %d nfq_create_queue() error", nfq_num);
exit(EXIT_FAILURE);
}
if (nfq_set_mode(qh, NFQNL_COPY_PACKET, 0xffff) < 0) {
fprintf(stderr, "nfq error: queue %d nfq_set_mode() error", nfq_num);
exit(EXIT_FAILURE);
}
return h;
}
Since every thread do nfq_open(), has a separate descriptor and etc, i think
i don't need a lock around recv() and nfq_set_verdict2(). Am i right?
Thanks!
--
Олег Неманов (Oleg Nemanov)
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: libnetfilter_queue & multithreading
2017-07-22 13:08 libnetfilter_queue & multithreading Oleg
@ 2017-07-22 16:38 ` Florian Westphal
2017-07-24 9:40 ` Oleg
0 siblings, 1 reply; 5+ messages in thread
From: Florian Westphal @ 2017-07-22 16:38 UTC (permalink / raw)
To: Oleg; +Cc: netfilter-devel
Oleg <lego12239@yandex.ru> wrote:
> My program process multiple NFQUEUEs by creating a separate thread
> for every NFQUEUE. An each thread do recv() and nfq_set_verdict2():
[..]
> main()
> {
> ...
> for(i = 0; i < q_cnt; i++) {
> ret = pthread_create(&(thread_data[i].id), NULL, thread_start,
> &thread_data[i].nfq_num);
> if (ret != 0) {
> fprintf(stderr, "thread creation error: %s", strerror(ret));
> exit(EXIT_FAILURE);
> }
> }
> ...
> }
>
> static void*
> thread_start(void *data)
> {
> struct nfq_handle *h;
> int fd, n;
> static char *pkt_buf;
static? Looks buggy...
> Since every thread do nfq_open(), has a separate descriptor and etc, i think
> i don't need a lock around recv() and nfq_set_verdict2(). Am i right?
Yes, as long as all threads have their own receive buffer this
won't need locks.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: libnetfilter_queue & multithreading
2017-07-22 16:38 ` Florian Westphal
@ 2017-07-24 9:40 ` Oleg
2017-07-24 9:44 ` Florian Westphal
0 siblings, 1 reply; 5+ messages in thread
From: Oleg @ 2017-07-24 9:40 UTC (permalink / raw)
To: Florian Westphal; +Cc: netfilter-devel
On Sat, Jul 22, 2017 at 06:38:55PM +0200, Florian Westphal wrote:
> Oleg <lego12239@yandex.ru> wrote:
> > static void*
> > thread_start(void *data)
> > {
> > struct nfq_handle *h;
> > int fd, n;
> > static char *pkt_buf;
>
> static? Looks buggy...
Hm, why :-)? This function must be local and shouldn't be seen in other
source files.
--
Олег Неманов (Oleg Nemanov)
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: libnetfilter_queue & multithreading
2017-07-24 9:40 ` Oleg
@ 2017-07-24 9:44 ` Florian Westphal
2017-07-24 10:11 ` Oleg
0 siblings, 1 reply; 5+ messages in thread
From: Florian Westphal @ 2017-07-24 9:44 UTC (permalink / raw)
To: Oleg; +Cc: Florian Westphal, netfilter-devel
Oleg <lego12239@yandex.ru> wrote:
> On Sat, Jul 22, 2017 at 06:38:55PM +0200, Florian Westphal wrote:
> > Oleg <lego12239@yandex.ru> wrote:
> > > static void*
> > > thread_start(void *data)
> > > {
> > > struct nfq_handle *h;
> > > int fd, n;
> > > static char *pkt_buf;
> >
> > static? Looks buggy...
>
> Hm, why :-)? This function must be local and shouldn't be seen in other
> source files.
I was talking about pkt_buf.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: libnetfilter_queue & multithreading
2017-07-24 9:44 ` Florian Westphal
@ 2017-07-24 10:11 ` Oleg
0 siblings, 0 replies; 5+ messages in thread
From: Oleg @ 2017-07-24 10:11 UTC (permalink / raw)
To: Florian Westphal; +Cc: netfilter-devel
On Mon, Jul 24, 2017 at 11:44:51AM +0200, Florian Westphal wrote:
> Oleg <lego12239@yandex.ru> wrote:
> > On Sat, Jul 22, 2017 at 06:38:55PM +0200, Florian Westphal wrote:
> > > Oleg <lego12239@yandex.ru> wrote:
> > > > static void*
> > > > thread_start(void *data)
> > > > {
> > > > struct nfq_handle *h;
> > > > int fd, n;
> > > > static char *pkt_buf;
> > >
> > > static? Looks buggy...
> >
> > Hm, why :-)? This function must be local and shouldn't be seen in other
> > source files.
>
> I was talking about pkt_buf.
Wow. You are right. This is a copy-paste error. Thank you!
--
Олег Неманов (Oleg Nemanov)
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2017-07-24 10:09 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2017-07-22 13:08 libnetfilter_queue & multithreading Oleg
2017-07-22 16:38 ` Florian Westphal
2017-07-24 9:40 ` Oleg
2017-07-24 9:44 ` Florian Westphal
2017-07-24 10:11 ` Oleg
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