callback.c
/*
* (C) 2005-2011 by Pablo Neira Ayuso <pablo@netfilter.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include "internal/internal.h"
#include <libmnl/libmnl.h>
static int __parse_message(const struct nlmsghdr *nlh)
{
uint16_t type = NFNL_MSG_TYPE(nlh->nlmsg_type);
uint16_t flags = nlh->nlmsg_flags;
int ret = NFCT_T_UNKNOWN;
switch(type) {
case IPCTNL_MSG_CT_NEW: /* same value for IPCTNL_MSG_EXP_NEW. */
if (flags & (NLM_F_CREATE|NLM_F_EXCL))
ret = NFCT_T_NEW;
else
ret = NFCT_T_UPDATE;
break;
case IPCTNL_MSG_CT_DELETE: /* same value for IPCTNL_MSG_EXP_DELETE. */
ret = NFCT_T_DESTROY;
break;
}
return ret;
}
/* This function uses libmnl helpers, the nfa[] array is intentionally not used
* since it has a different layout.
*/
int __callback(struct nlmsghdr *nlh, struct nfattr *nfa[], void *data)
{
int ret = NFNL_CB_STOP;
unsigned int type;
struct nf_conntrack *ct = NULL;
struct nf_expect *exp = NULL;
struct __data_container *container = data;
uint8_t subsys = NFNL_SUBSYS_ID(nlh->nlmsg_type);
if (nlh->nlmsg_len < NLMSG_LENGTH(sizeof(struct nfgenmsg))) {
errno = EINVAL;
return NFNL_CB_FAILURE;
}
type = __parse_message(nlh);
if (!(type & container->type))
return NFNL_CB_CONTINUE;
switch(subsys) {
case NFNL_SUBSYS_CTNETLINK:
ct = nfct_new();
if (ct == NULL)
return NFNL_CB_FAILURE;
nfct_nlmsg_parse(nlh, ct);
if (container->h->cb) {
ret = container->h->cb(type, ct, container->data);
} else if (container->h->cb2) {
ret = container->h->cb2(nlh, type, ct,
container->data);
}
break;
case NFNL_SUBSYS_CTNETLINK_EXP:
exp = nfexp_new();
if (exp == NULL)
return NFNL_CB_FAILURE;
nfexp_nlmsg_parse(nlh, exp);
if (container->h->expect_cb) {
ret = container->h->expect_cb(type, exp,
container->data);
} else if (container->h->expect_cb2) {
ret = container->h->expect_cb2(nlh, type, exp,
container->data);
}
break;
default:
errno = ENOTSUP;
ret = NFNL_CB_FAILURE;
break;
}
if (ret == NFCT_CB_STOLEN)
return NFNL_CB_CONTINUE;
if (ct)
nfct_destroy(ct);
if (exp)
nfexp_destroy(exp);
return ret;
}
nfct_destroy
void nfct_destroy(struct nf_conntrack *ct)
Definition conntrack/api.c:93
nfct_new
struct nf_conntrack * nfct_new(void)
Definition conntrack/api.c:76
nfexp_new
struct nf_expect * nfexp_new(void)
Definition expect/api.c:29
nfexp_destroy
void nfexp_destroy(struct nf_expect *exp)
Definition expect/api.c:46