log.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.
*
* This code has been sponsored by Sophos Astaro <http://www.sophos.com>
*/
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <arpa/inet.h>
#include <errno.h>
#include <linux/netfilter/nf_tables.h>
#include <linux/netfilter/nf_log.h>
#include "internal.h"
#include <libmnl/libmnl.h>
#include <libnftnl/expr.h>
#include <libnftnl/rule.h>
struct nftnl_expr_log {
uint32_t snaplen;
uint16_t group;
uint16_t qthreshold;
uint32_t level;
uint32_t flags;
const char *prefix;
};
static int nftnl_expr_log_set(struct nftnl_expr *e, uint16_t type,
const void *data, uint32_t data_len)
{
struct nftnl_expr_log *log = nftnl_expr_data(e);
switch(type) {
case NFTNL_EXPR_LOG_PREFIX:
if (log->flags & (1 << NFTNL_EXPR_LOG_PREFIX))
xfree(log->prefix);
log->prefix = strdup(data);
if (!log->prefix)
return -1;
break;
case NFTNL_EXPR_LOG_GROUP:
memcpy(&log->group, data, sizeof(log->group));
break;
case NFTNL_EXPR_LOG_SNAPLEN:
memcpy(&log->snaplen, data, sizeof(log->snaplen));
break;
case NFTNL_EXPR_LOG_QTHRESHOLD:
memcpy(&log->qthreshold, data, sizeof(log->qthreshold));
break;
case NFTNL_EXPR_LOG_LEVEL:
memcpy(&log->level, data, sizeof(log->level));
break;
case NFTNL_EXPR_LOG_FLAGS:
memcpy(&log->flags, data, sizeof(log->flags));
break;
default:
return -1;
}
return 0;
}
static const void *
nftnl_expr_log_get(const struct nftnl_expr *e, uint16_t type,
uint32_t *data_len)
{
struct nftnl_expr_log *log = nftnl_expr_data(e);
switch(type) {
case NFTNL_EXPR_LOG_PREFIX:
*data_len = strlen(log->prefix)+1;
return log->prefix;
case NFTNL_EXPR_LOG_GROUP:
*data_len = sizeof(log->group);
return &log->group;
case NFTNL_EXPR_LOG_SNAPLEN:
*data_len = sizeof(log->snaplen);
return &log->snaplen;
case NFTNL_EXPR_LOG_QTHRESHOLD:
*data_len = sizeof(log->qthreshold);
return &log->qthreshold;
case NFTNL_EXPR_LOG_LEVEL:
*data_len = sizeof(log->level);
return &log->level;
case NFTNL_EXPR_LOG_FLAGS:
*data_len = sizeof(log->flags);
return &log->flags;
}
return NULL;
}
static int nftnl_expr_log_cb(const struct nlattr *attr, void *data)
{
const struct nlattr **tb = data;
int type = mnl_attr_get_type(attr);
if (mnl_attr_type_valid(attr, NFTA_LOG_MAX) < 0)
return MNL_CB_OK;
switch(type) {
case NFTA_LOG_PREFIX:
if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0)
abi_breakage();
break;
case NFTA_LOG_GROUP:
case NFTA_LOG_QTHRESHOLD:
if (mnl_attr_validate(attr, MNL_TYPE_U16) < 0)
abi_breakage();
break;
case NFTA_LOG_SNAPLEN:
case NFTA_LOG_LEVEL:
case NFTA_LOG_FLAGS:
if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
abi_breakage();
break;
}
tb[type] = attr;
return MNL_CB_OK;
}
static void
nftnl_expr_log_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
{
struct nftnl_expr_log *log = nftnl_expr_data(e);
if (e->flags & (1 << NFTNL_EXPR_LOG_PREFIX))
mnl_attr_put_strz(nlh, NFTA_LOG_PREFIX, log->prefix);
if (e->flags & (1 << NFTNL_EXPR_LOG_GROUP))
mnl_attr_put_u16(nlh, NFTA_LOG_GROUP, htons(log->group));
if (e->flags & (1 << NFTNL_EXPR_LOG_SNAPLEN))
mnl_attr_put_u32(nlh, NFTA_LOG_SNAPLEN, htonl(log->snaplen));
if (e->flags & (1 << NFTNL_EXPR_LOG_QTHRESHOLD))
mnl_attr_put_u16(nlh, NFTA_LOG_QTHRESHOLD, htons(log->qthreshold));
if (e->flags & (1 << NFTNL_EXPR_LOG_LEVEL))
mnl_attr_put_u32(nlh, NFTA_LOG_LEVEL, htonl(log->level));
if (e->flags & (1 << NFTNL_EXPR_LOG_FLAGS))
mnl_attr_put_u32(nlh, NFTA_LOG_FLAGS, htonl(log->flags));
}
static int
nftnl_expr_log_parse(struct nftnl_expr *e, struct nlattr *attr)
{
struct nftnl_expr_log *log = nftnl_expr_data(e);
struct nlattr *tb[NFTA_LOG_MAX+1] = {};
if (mnl_attr_parse_nested(attr, nftnl_expr_log_cb, tb) < 0)
return -1;
if (tb[NFTA_LOG_PREFIX]) {
if (log->prefix)
xfree(log->prefix);
log->prefix = strdup(mnl_attr_get_str(tb[NFTA_LOG_PREFIX]));
if (!log->prefix)
return -1;
e->flags |= (1 << NFTNL_EXPR_LOG_PREFIX);
}
if (tb[NFTA_LOG_GROUP]) {
log->group = ntohs(mnl_attr_get_u16(tb[NFTA_LOG_GROUP]));
e->flags |= (1 << NFTNL_EXPR_LOG_GROUP);
}
if (tb[NFTA_LOG_SNAPLEN]) {
log->snaplen = ntohl(mnl_attr_get_u32(tb[NFTA_LOG_SNAPLEN]));
e->flags |= (1 << NFTNL_EXPR_LOG_SNAPLEN);
}
if (tb[NFTA_LOG_QTHRESHOLD]) {
log->qthreshold = ntohs(mnl_attr_get_u16(tb[NFTA_LOG_QTHRESHOLD]));
e->flags |= (1 << NFTNL_EXPR_LOG_QTHRESHOLD);
}
if (tb[NFTA_LOG_LEVEL]) {
log->level = ntohl(mnl_attr_get_u32(tb[NFTA_LOG_LEVEL]));
e->flags |= (1 << NFTNL_EXPR_LOG_LEVEL);
}
if (tb[NFTA_LOG_FLAGS]) {
log->flags = ntohl(mnl_attr_get_u32(tb[NFTA_LOG_FLAGS]));
e->flags |= (1 << NFTNL_EXPR_LOG_FLAGS);
}
return 0;
}
static int nftnl_expr_log_snprintf_default(char *buf, size_t size,
const struct nftnl_expr *e)
{
struct nftnl_expr_log *log = nftnl_expr_data(e);
int ret, offset = 0, remain = size;
if (e->flags & (1 << NFTNL_EXPR_LOG_PREFIX)) {
ret = snprintf(buf, remain, "prefix %s ", log->prefix);
SNPRINTF_BUFFER_SIZE(ret, remain, offset);
}
if (e->flags & (1 << NFTNL_EXPR_LOG_GROUP)) {
ret = snprintf(buf + offset, remain,
"group %u snaplen %u qthreshold %u ",
log->group, log->snaplen, log->qthreshold);
SNPRINTF_BUFFER_SIZE(ret, remain, offset);
} else {
if (e->flags & (1 << NFTNL_EXPR_LOG_LEVEL)) {
ret = snprintf(buf + offset, remain, "level %u ",
log->level);
SNPRINTF_BUFFER_SIZE(ret, remain, offset);
}
if (e->flags & (1 << NFTNL_EXPR_LOG_FLAGS)) {
if (log->flags & NF_LOG_TCPSEQ) {
ret = snprintf(buf + offset, remain, "tcpseq ");
SNPRINTF_BUFFER_SIZE(ret, remain, offset);
}
if (log->flags & NF_LOG_TCPOPT) {
ret = snprintf(buf + offset, remain, "tcpopt ");
SNPRINTF_BUFFER_SIZE(ret, remain, offset);
}
if (log->flags & NF_LOG_IPOPT) {
ret = snprintf(buf + offset, remain, "ipopt ");
SNPRINTF_BUFFER_SIZE(ret, remain, offset);
}
if (log->flags & NF_LOG_UID) {
ret = snprintf(buf + offset, remain, "uid ");
SNPRINTF_BUFFER_SIZE(ret, remain, offset);
}
if (log->flags & NF_LOG_MACDECODE) {
ret = snprintf(buf + offset, remain,
"macdecode ");
SNPRINTF_BUFFER_SIZE(ret, remain, offset);
}
}
}
return offset;
}
static int
nftnl_expr_log_snprintf(char *buf, size_t len, uint32_t type,
uint32_t flags, const struct nftnl_expr *e)
{
switch(type) {
case NFTNL_OUTPUT_DEFAULT:
return nftnl_expr_log_snprintf_default(buf, len, e);
case NFTNL_OUTPUT_XML:
case NFTNL_OUTPUT_JSON:
default:
break;
}
return -1;
}
static void nftnl_expr_log_free(const struct nftnl_expr *e)
{
struct nftnl_expr_log *log = nftnl_expr_data(e);
xfree(log->prefix);
}
struct expr_ops expr_ops_log = {
.name = "log",
.alloc_len = sizeof(struct nftnl_expr_log),
.max_attr = NFTA_LOG_MAX,
.free = nftnl_expr_log_free,
.set = nftnl_expr_log_set,
.get = nftnl_expr_log_get,
.parse = nftnl_expr_log_parse,
.build = nftnl_expr_log_build,
.snprintf = nftnl_expr_log_snprintf,
};
nftnl_expr_log
Definition: log.c:25