common.c
/*
* (C) 2012-2013 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 <stdlib.h>
#include <sys/socket.h>
#include <time.h>
#include <linux/netlink.h>
#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nf_tables.h>
#include <libmnl/libmnl.h>
#include <libnftnl/common.h>
#include <libnftnl/set.h>
#include <errno.h>
#include "internal.h"
static struct nlmsghdr *__nftnl_nlmsg_build_hdr(char *buf, uint16_t type,
uint16_t family,
uint16_t flags, uint32_t seq,
uint16_t res_id)
{
struct nlmsghdr *nlh;
struct nfgenmsg *nfh;
nlh = mnl_nlmsg_put_header(buf);
nlh->nlmsg_type = type;
nlh->nlmsg_flags = NLM_F_REQUEST | flags;
nlh->nlmsg_seq = seq;
nfh = mnl_nlmsg_put_extra_header(nlh, sizeof(struct nfgenmsg));
nfh->nfgen_family = family;
nfh->version = NFNETLINK_V0;
nfh->res_id = res_id;
return nlh;
}
EXPORT_SYMBOL(nftnl_nlmsg_build_hdr);
struct nlmsghdr *nftnl_nlmsg_build_hdr(char *buf, uint16_t type, uint16_t family,
uint16_t flags, uint32_t seq)
{
return __nftnl_nlmsg_build_hdr(buf, (NFNL_SUBSYS_NFTABLES << 8) | type,
family, flags, seq, 0);
}
EXPORT_SYMBOL(nftnl_parse_err_alloc);
struct nftnl_parse_err *nftnl_parse_err_alloc(void)
{
struct nftnl_parse_err *err;
err = calloc(1, sizeof(struct nftnl_parse_err));
if (err == NULL)
return NULL;
err->error = NFTNL_PARSE_EOPNOTSUPP;
return err;
}
EXPORT_SYMBOL(nftnl_parse_err_free);
void nftnl_parse_err_free(struct nftnl_parse_err *err)
{
xfree(err);
}
EXPORT_SYMBOL(nftnl_parse_perror);
int nftnl_parse_perror(const char *msg, struct nftnl_parse_err *err)
{
switch (err->error) {
case NFTNL_PARSE_EBADINPUT:
return fprintf(stderr, "%s: Bad input format in line %d column %d\n",
msg, err->line, err->column);
case NFTNL_PARSE_EMISSINGNODE:
return fprintf(stderr, "%s: Node \"%s\" not found\n",
msg, err->node_name);
case NFTNL_PARSE_EBADTYPE:
return fprintf(stderr, "%s: Invalid type in node \"%s\"\n",
msg, err->node_name);
case NFTNL_PARSE_EOPNOTSUPP:
return fprintf(stderr, "%s: Operation not supported\n", msg);
default:
return fprintf(stderr, "%s: Undefined error\n", msg);
}
}
EXPORT_SYMBOL(nftnl_batch_begin);
struct nlmsghdr *nftnl_batch_begin(char *buf, uint32_t seq)
{
return __nftnl_nlmsg_build_hdr(buf, NFNL_MSG_BATCH_BEGIN, AF_UNSPEC,
0, seq, NFNL_SUBSYS_NFTABLES);
}
EXPORT_SYMBOL(nftnl_batch_end);
struct nlmsghdr *nftnl_batch_end(char *buf, uint32_t seq)
{
return __nftnl_nlmsg_build_hdr(buf, NFNL_MSG_BATCH_END, AF_UNSPEC,
0, seq, NFNL_SUBSYS_NFTABLES);
}
EXPORT_SYMBOL(nftnl_batch_is_supported);
int nftnl_batch_is_supported(void)
{
struct mnl_socket *nl;
struct mnl_nlmsg_batch *b;
char buf[MNL_SOCKET_BUFFER_SIZE];
uint32_t seq = time(NULL), req_seq;
int ret;
nl = mnl_socket_open(NETLINK_NETFILTER);
if (nl == NULL)
return -1;
if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0)
return -1;
b = mnl_nlmsg_batch_start(buf, sizeof(buf));
nftnl_batch_begin(mnl_nlmsg_batch_current(b), seq++);
mnl_nlmsg_batch_next(b);
req_seq = seq;
nftnl_set_nlmsg_build_hdr(mnl_nlmsg_batch_current(b),
NFT_MSG_NEWSET, AF_INET,
NLM_F_ACK, seq++);
mnl_nlmsg_batch_next(b);
nftnl_batch_end(mnl_nlmsg_batch_current(b), seq++);
mnl_nlmsg_batch_next(b);
ret = mnl_socket_sendto(nl, mnl_nlmsg_batch_head(b),
mnl_nlmsg_batch_size(b));
if (ret < 0)
goto err;
mnl_nlmsg_batch_stop(b);
ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
while (ret > 0) {
ret = mnl_cb_run(buf, ret, req_seq, mnl_socket_get_portid(nl),
NULL, NULL);
if (ret <= 0)
break;
ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
}
mnl_socket_close(nl);
/* We're sending an incomplete message to see if the kernel supports
* set messages in batches. EINVAL means that we sent an incomplete
* message with missing attributes. The kernel just ignores messages
* that we cannot include in the batch.
*/
return (ret == -1 && errno == EINVAL) ? 1 : 0;
err:
mnl_nlmsg_batch_stop(b);
return -1;
}