/**
* nflog_set_flags - set the nflog flags for this group
* \param gh Netfilter log handle obtained by call to nflog_bind_group().
* \param flags Flags that you want to set
*
* There are two existing flags:
*
* - NFULNL_CFG_F_SEQ: This enables local nflog sequence numbering.
* - NFULNL_CFG_F_SEQ_GLOBAL: This enables global nflog sequence numbering.
*
* \return -1 in case of error and errno is explicity set.
*/
int nflog_set_flags(struct nflog_g_handle *gh, uint16_t flags)
{
union {
char buf[NFNL_HEADER_LEN+NFA_LENGTH(sizeof(uint16_t))];
struct nlmsghdr nmh;
} u;
nfnl_fill_hdr(gh->h->nfnlssh, &u.nmh, 0, AF_UNSPEC, gh->id,
NFULNL_MSG_CONFIG, NLM_F_REQUEST|NLM_F_ACK);
nfnl_addattr16(&u.nmh, sizeof(u), NFULA_CFG_FLAGS, htons(flags));
return nfnl_query(gh->h->nfnlh, &u.nmh);
}
/**
* nflog_set_qthresh - set the maximum amount of logs in buffer for this group
* \param gh Netfilter log handle obtained by call to nflog_bind_group().
* \param qthresh Maximum number of log entries
*
* This function determines the maximum number of log entries in the buffer
* until it is pushed to userspace.
*
* \return -1 in case of error and errno is explicity set.
*/
int nflog_set_qthresh(struct nflog_g_handle *gh, uint32_t qthresh)
{
union {
char buf[NFNL_HEADER_LEN+NFA_LENGTH(sizeof(uint32_t))];
struct nlmsghdr nmh;
} u;
nfnl_fill_hdr(gh->h->nfnlssh, &u.nmh, 0, AF_UNSPEC, gh->id,
NFULNL_MSG_CONFIG, NLM_F_REQUEST|NLM_F_ACK);
nfnl_addattr32(&u.nmh, sizeof(u), NFULA_CFG_QTHRESH, htonl(qthresh));
return nfnl_query(gh->h->nfnlh, &u.nmh);
}
/**
* nfexp_query - send a query to ctnetlink
* \param h library handler
* \param qt query type
* \param data data required to send the query
*
* On error, -1 is returned and errno is explicitely set. On success, 0
* is returned.
*/
int nfexp_query(struct nfct_handle *h,
const enum nf_conntrack_query qt,
const void *data)
{
const size_t size = 4096; /* enough for now */
union {
char buffer[size];
struct nfnlhdr req;
} u;
assert(h != NULL);
assert(data != NULL);
if (__build_query_exp(h->nfnlssh_exp, qt, data, &u.req, size) == -1)
return -1;
return nfnl_query(h->nfnlh, &u.req.nlh);
}
/* build a NFULNL_MSG_CONFIG message */
static int
__build_send_cfg_msg(struct nflog_handle *h, uint8_t command,
uint16_t groupnum, uint8_t pf)
{
union {
char buf[NFNL_HEADER_LEN
+NFA_LENGTH(sizeof(struct nfulnl_msg_config_cmd))];
struct nlmsghdr nmh;
} u;
struct nfulnl_msg_config_cmd cmd;
nfnl_fill_hdr(h->nfnlssh, &u.nmh, 0, pf, groupnum,
NFULNL_MSG_CONFIG, NLM_F_REQUEST|NLM_F_ACK);
cmd.command = command;
nfnl_addattr_l(&u.nmh, sizeof(u), NFULA_CFG_CMD, &cmd, sizeof(cmd));
return nfnl_query(h->nfnlh, &u.nmh);
}
/**
* nflog_set_mode - set the amount of packet data that nflog copies to userspace
* \param qh Netfilter log handle obtained by call to nflog_bind_group().
* \param mode the part of the packet that we are interested in
* \param range size of the packet that we want to get
*
* Sets the amount of data to be copied to userspace for each packet logged
* to the given group.
*
* - NFULNL_COPY_NONE - do not copy any data
* - NFULNL_COPY_META - copy only packet metadata
* - NFULNL_COPY_PACKET - copy entire packet
*
* \return -1 on error; >= otherwise.
*/
int nflog_set_mode(struct nflog_g_handle *gh,
uint8_t mode, uint32_t range)
{
union {
char buf[NFNL_HEADER_LEN
+NFA_LENGTH(sizeof(struct nfulnl_msg_config_mode))];
struct nlmsghdr nmh;
} u;
struct nfulnl_msg_config_mode params;
nfnl_fill_hdr(gh->h->nfnlssh, &u.nmh, 0, AF_UNSPEC, gh->id,
NFULNL_MSG_CONFIG, NLM_F_REQUEST|NLM_F_ACK);
params.copy_range = htonl(range); /* copy_range is short */
params.copy_mode = mode;
nfnl_addattr_l(&u.nmh, sizeof(u), NFULA_CFG_MODE, ¶ms,
sizeof(params));
return nfnl_query(gh->h->nfnlh, &u.nmh);
}
/**
* nflog_set_nlbufsiz - set the size of the nflog buffer for this group
* \param gh Netfilter log handle obtained by call to nflog_bind_group().
* \param nlbufsiz Size of the nflog buffer
*
* This function sets the size (in bytes) of the buffer that is used to
* stack log messages in nflog.
*
* NOTE: The use of this function is strongly discouraged. The default
* buffer size (which is one memory page) provides the optimum results
* in terms of performance. Do not use this function in your applications.
*
* \return -1 in case of error and errno is explicity set.
*/
int nflog_set_nlbufsiz(struct nflog_g_handle *gh, uint32_t nlbufsiz)
{
union {
char buf[NFNL_HEADER_LEN+NFA_LENGTH(sizeof(uint32_t))];
struct nlmsghdr nmh;
} u;
int status;
nfnl_fill_hdr(gh->h->nfnlssh, &u.nmh, 0, AF_UNSPEC, gh->id,
NFULNL_MSG_CONFIG, NLM_F_REQUEST|NLM_F_ACK);
nfnl_addattr32(&u.nmh, sizeof(u), NFULA_CFG_NLBUFSIZ, htonl(nlbufsiz));
status = nfnl_query(gh->h->nfnlh, &u.nmh);
/* we try to have space for at least 10 messages in the socket buffer */
if (status >= 0)
nfnl_rcvbufsiz(gh->h->nfnlh, 10*nlbufsiz);
return status;
}
