/**
* nfnl_open - open a nfnetlink handler
*
* This function creates a nfnetlink handler, this is required to establish
* a communication between the userspace and the nfnetlink system.
*
* On success, a valid address that points to a nfnl_handle structure
* is returned. On error, NULL is returned and errno is set approapiately.
*/
struct nfnl_handle *nfnl_open(void)
{
struct nfnl_handle *nfnlh;
unsigned int addr_len;
nfnlh = malloc(sizeof(*nfnlh));
if (!nfnlh)
return NULL;
memset(nfnlh, 0, sizeof(*nfnlh));
nfnlh->fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_NETFILTER);
if (nfnlh->fd == -1)
goto err_free;
nfnlh->local.nl_family = AF_NETLINK;
nfnlh->peer.nl_family = AF_NETLINK;
addr_len = sizeof(nfnlh->local);
getsockname(nfnlh->fd, (struct sockaddr *)&nfnlh->local, &addr_len);
if (addr_len != sizeof(nfnlh->local)) {
errno = EINVAL;
goto err_close;
}
if (nfnlh->local.nl_family != AF_NETLINK) {
errno = EINVAL;
goto err_close;
}
nfnlh->seq = time(NULL);
nfnlh->rcv_buffer_size = NFNL_BUFFSIZE;
/* don't set pid here, only first socket of process has real pid !!!
* binding to pid '0' will default */
/* let us do the initial bind */
if (recalc_rebind_subscriptions(nfnlh) < 0)
goto err_close;
/* use getsockname to get the netlink pid that the kernel assigned us */
addr_len = sizeof(nfnlh->local);
getsockname(nfnlh->fd, (struct sockaddr *)&nfnlh->local, &addr_len);
if (addr_len != sizeof(nfnlh->local)) {
errno = EINVAL;
goto err_close;
}
/* sequence tracking enabled by default */
nfnlh->flags |= NFNL_F_SEQTRACK_ENABLED;
return nfnlh;
err_close:
close(nfnlh->fd);
err_free:
free(nfnlh);
return NULL;
}
/**
* nfnl_subsys_open - open a netlink subsystem
* @nfnlh: libnfnetlink handle
* @subsys_id: which nfnetlink subsystem we are interested in
* @cb_count: number of callbacks that are used maximum.
* @subscriptions: netlink groups we want to be subscribed to
*
* This function creates a subsystem handler that contains the set of
* callbacks that handle certain types of messages coming from a netfilter
* subsystem. Initially the callback set is empty, you can register callbacks
* via nfnl_callback_register().
*
* On error, NULL is returned and errno is set appropiately. On success,
* a valid address that points to a nfnl_subsys_handle structure is returned.
*/
struct nfnl_subsys_handle *
nfnl_subsys_open(struct nfnl_handle *nfnlh, uint8_t subsys_id,
uint8_t cb_count, uint32_t subscriptions)
{
struct nfnl_subsys_handle *ssh;
assert(nfnlh);
if (subsys_id > NFNL_MAX_SUBSYS) {
errno = ENOENT;
return NULL;
}
ssh = &nfnlh->subsys[subsys_id];
if (ssh->cb) {
errno = EBUSY;
return NULL;
}
ssh->cb = calloc(cb_count, sizeof(*(ssh->cb)));
if (!ssh->cb)
return NULL;
ssh->nfnlh = nfnlh;
ssh->cb_count = cb_count;
ssh->subscriptions = subscriptions;
ssh->subsys_id = subsys_id;
/* although now we have nfnl_join to subscribe to certain
* groups, just keep this to ensure compatibility */
if (recalc_rebind_subscriptions(nfnlh) < 0) {
free(ssh->cb);
ssh->cb = NULL;
return NULL;
}
return ssh;
}
/**
* nfnl_open - open a nfnetlink handler
*
* This function creates a nfnetlink handler, this is required to establish
* a communication between the userspace and the nfnetlink system.
*
* On success, a valid address that points to a nfnl_handle structure
* is returned. On error, NULL is returned and errno is set approapiately.
*/
struct nfnl_handle *nfnl_open(void)
{
struct nfnl_handle *nfnlh;
unsigned int addr_len;
int err;
nfnlh = malloc(sizeof(*nfnlh));
if (!nfnlh)
return NULL;
memset(nfnlh, 0, sizeof(*nfnlh));
nfnlh->fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_NETFILTER);
if (nfnlh->fd == -1)
goto err_free;
nfnlh->local.nl_family = AF_NETLINK;
nfnlh->peer.nl_family = AF_NETLINK;
addr_len = sizeof(nfnlh->local);
err = getsockname(nfnlh->fd, (struct sockaddr *)&nfnlh->local,
&addr_len);
if (addr_len != sizeof(nfnlh->local)) {
errno = EINVAL;
goto err_close;
}
if (nfnlh->local.nl_family != AF_NETLINK) {
errno = EINVAL;
goto err_close;
}
nfnlh->seq = time(NULL);
/* don't set pid here, only first socket of process has real pid !!!
* binding to pid '0' will default */
/* let us do the initial bind */
if (recalc_rebind_subscriptions(nfnlh) < 0)
goto err_close;
/* use getsockname to get the netlink pid that the kernel assigned us */
addr_len = sizeof(nfnlh->local);
err = getsockname(nfnlh->fd, (struct sockaddr *)&nfnlh->local,
&addr_len);
if (addr_len != sizeof(nfnlh->local)) {
errno = EINVAL;
goto err_close;
}
#if defined(AEI_VDSL_CUSTOMER_NCS)
printf("set NETLINK_RECV_NO_ENOBUFS\n");
unsigned int enable=1;
setsockopt(nfnlh->fd, SOL_NETLINK, NETLINK_NO_ENOBUFS,
&enable, sizeof(enable));
#endif
return nfnlh;
err_close:
close(nfnlh->fd);
err_free:
free(nfnlh);
return NULL;
}
