/* libnetfilter_queue.c: generic library for access to nf_queue
*
* (C) 2005 by Harald Welte <laforge@gnumonks.org>
* (C) 2005, 2008-2010 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 version 2
* as published by the Free Software Foundation (or any later at your option)
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* 2006-01-23 Andreas Florath <andreas@florath.net>
* Fix __set_verdict() that it can now handle payload.
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <ctype.h>
#include <time.h>
#include <errno.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <libnfnetlink/libnfnetlink.h>
#include <libnetfilter_queue/libnetfilter_queue.h>
#include "internal.h"
/**
* \mainpage
*
* libnetfilter_queue is a userspace library providing an API to packets that
* have been queued by the kernel packet filter. It is is part of a system that
* replaces the old ip_queue / libipq mechanism (withdrawn in kernel 3.5).
*
* libnetfilter_queue homepage is:
* https://netfilter.org/projects/libnetfilter_queue/
*
* \section deps Dependencies
* libnetfilter_queue requires libmnl, libnfnetlink and a kernel that includes
* the Netfilter NFQUEUE over NFNETLINK interface (i.e. 2.6.14 or later).
*
* \section features Main Features
* - receiving queued packets from the kernel nfnetlink_queue subsystem
* - issuing verdicts and possibly reinjecting altered packets to the kernel
* nfnetlink_queue subsystem
*
* The cinematic is the following: When an nft rule with action **queue**
* matches, the kernel terminates the current nft chain and enqueues the packet
* in a chained list. It then formats and sends an nfnetlink message containing
* the packet id and whatever information the userspace program configured to
* receive (packet data and/or metadata) via a socket to the userspace program.
*
* The userspace program must issue a verdict advising the kernel to **accept**
* or **drop** the packet. Either verdict takes the packet off the queue:
* **drop** discards the packet while
* **accept** passes it on to the next chain.
* Userspace can also alter packet contents or metadata (e.g. packet mark,
* contrack mark). Verdict can be done in asynchronous manner, as the only
* needed information is the packet id.
*
* When a queue is full, packets that should have been enqueued are dropped by
* kernel instead of being enqueued.
*
* \section git Git Tree
* The current development version of libnetfilter_queue can be accessed at
* https://git.netfilter.org/libnetfilter_queue.
*
* \section privs Privileges
* You need the CAP_NET_ADMIN capability in order to allow your application
* to receive from and to send packets to kernel-space.
*
* \section using Using libnetfilter_queue
*
* To write your own program using libnetfilter_queue, you should start by
* reading (or, if feasible, compiling and stepping through with *gdb*)
* nf-queue.c source file.
* Simple compile line:
* \verbatim
gcc -g3 -ggdb -Wall -lmnl -lnetfilter_queue -o nf-queue nf-queue.c
\endverbatim
* The doxygen documentation \link LibrarySetup \endlink is Deprecated and
* incompatible with non-deprecated functions. It is hoped to produce a
* corresponding non-deprecated (*Current*) topic soon.
*
* Somewhat outdated but possibly providing some insight into
* libnetfilter_queue usage is the following
* article:
* https://home.regit.org/netfilter-en/using-nfqueue-and-libnetfilter_queue/
*
* \section errors ENOBUFS errors in recv()
*
* recv() may return -1 and errno is set to ENOBUFS in case that your
* application is not fast enough to retrieve the packets from the kernel.
* In that case, you can increase the socket buffer size by means of
* nfnl_rcvbufsiz(). Although this delays the appearance of ENOBUFS errors,
* you may hit it again sooner or later. The next section provides some hints
* on how to obtain the best performance for your application.
*
* \section perf Performance
* To improve your libnetfilter_queue application in terms of performance,
* you may consider the following tweaks:
*
* - increase the default socket buffer size by means of nfnl_rcvbufsiz().
* - set nice value of your process to -20 (maximum priority).
* - set the CPU affinity of your process to a spare core that is not used
* to handle NIC interruptions.
* - set NETLINK_NO_ENOBUFS socket option to avoid receiving ENOBUFS errors
* (requires Linux kernel >= 2.6.30).
* - see --queue-balance option in NFQUEUE target for multi-threaded apps
* (it requires Linux kernel >= 2.6.31).
* - consider using fail-open option see nfq_set_queue_flags() (it requires
* Linux kernel >= 3.6)
* - increase queue max length with nfq_set_queue_maxlen() to resist to packets
* burst
*/
struct nfq_handle
{
struct nfnl_handle *nfnlh;
struct nfnl_subsys_handle *nfnlssh;
struct nfq_q_handle *qh_list;
};
struct nfq_q_handle
{
struct nfq_q_handle *next;
struct nfq_handle *h;
uint16_t id;
nfq_callback *cb;
void *data;
};
struct nfq_data {
struct nfattr **data;
};
EXPORT_SYMBOL int nfq_errno;
/***********************************************************************
* low level stuff
***********************************************************************/
static void del_qh(struct nfq_q_handle *qh)
{
struct nfq_q_handle *cur_qh, *prev_qh = NULL;
for (cur_qh = qh->h->qh_list; cur_qh; cur_qh = cur_qh->next) {
if (cur_qh == qh) {
if (prev_qh)
prev_qh->next = qh->next;
else
qh->h->qh_list = qh->next;
return;
}
prev_qh = cur_qh;
}
}
static void add_qh(struct nfq_q_handle *qh)
{
qh->next = qh->h->qh_list;
qh->h->qh_list = qh;
}
static struct nfq_q_handle *find_qh(struct nfq_handle *h, uint16_t id)
{
struct nfq_q_handle *qh;
for (qh = h->qh_list; qh; qh = qh->next) {
if (qh->id == id)
return qh;
}
return NULL;
}
/* build a NFQNL_MSG_CONFIG message */
static int
__build_send_cfg_msg(struct nfq_handle *h, uint8_t command,
uint16_t queuenum, uint16_t pf)
{
union {
char buf[NFNL_HEADER_LEN
+NFA_LENGTH(sizeof(struct nfqnl_msg_config_cmd))];
struct nlmsghdr nmh;
} u;
struct nfqnl_msg_config_cmd cmd;
nfnl_fill_hdr(h->nfnlssh, &u.nmh, 0, AF_UNSPEC, queuenum,
NFQNL_MSG_CONFIG, NLM_F_REQUEST|NLM_F_ACK);
cmd._pad = 0;
cmd.command = command;
cmd.pf = htons(pf);
nfnl_addattr_l(&u.nmh, sizeof(u), NFQA_CFG_CMD, &cmd, sizeof(cmd));
return nfnl_query(h->nfnlh, &u.nmh);
}
static int __nfq_rcv_pkt(struct nlmsghdr *nlh, struct nfattr *nfa[],
void *data)
{
struct nfgenmsg *nfmsg = NLMSG_DATA(nlh);
struct nfq_handle *h = data;
uint16_t queue_num = ntohs(nfmsg->res_id);
struct nfq_q_handle *qh = find_qh(h, queue_num);
struct nfq_data nfqa;
if (!qh)
return -ENODEV;
if (!qh->cb)
return -ENODEV;
nfqa.data = nfa;
return qh->cb(qh, nfmsg, &nfqa, qh->data);
}
/* public interface */
EXPORT_SYMBOL
struct nfnl_handle *nfq_nfnlh(struct nfq_handle *h)
{
return h->nfnlh;
}
/**
*
* \defgroup Queue Queue handling [DEPRECATED]
*
* Once libnetfilter_queue library has been initialised (See
* \link LibrarySetup \endlink), it is possible to bind the program to a
* specific queue. This can be done by using nfq_create_queue().
*
* The queue can then be tuned via nfq_set_mode() or nfq_set_queue_maxlen().
*
* Here's a little code snippet that create queue numbered 0:
* \verbatim
printf("binding this socket to queue '0'\n");
qh = nfq_create_queue(h, 0, &cb, NULL);
if (!qh) {
fprintf(stderr, "error during nfq_create_queue()\n");
exit(1);
}
printf("setting copy_packet mode\n");
if (nfq_set_mode(qh, NFQNL_COPY_PACKET, 0xffff) < 0) {
fprintf(stderr, "can't set packet_copy mode\n");
exit(1);
}
\endverbatim
*
* Next step is the handling of incoming packets which can be done via a loop:
*
* \verbatim
fd = nfq_fd(h);
while ((rv = recv(fd, buf, sizeof(buf), 0)) >= 0) {
printf("pkt received\n");
nfq_handle_packet(h, buf, rv);
}
\endverbatim
* When the decision on a packet has been choosed, the verdict has to be given
* by calling nfq_set_verdict() or nfq_set_verdict2(). The verdict
* determines the destiny of the packet as follows:
*
* - NF_DROP discarded the packet
* - NF_ACCEPT the packet passes, continue iterations
* - NF_QUEUE inject the packet into a different queue
* (the target queue number is in the high 16 bits of the verdict)
* - NF_REPEAT iterate the same cycle once more
* - NF_STOP accept, but don't continue iterations
*
* The verdict NF_STOLEN must not be used, as it has special meaning in the
* kernel.
* When using NF_REPEAT, one way to prevent re-queueing of the same packet
* is to also set an nfmark using nfq_set_verdict2, and set up the nefilter
* rules to only queue a packet when the mark is not (yet) set.
*
* Data and information about the packet can be fetch by using message parsing
* functions (See \link Parsing \endlink).
* @{
*/
/**
* nfq_fd - get the file descriptor associated with the nfqueue handler
* \param h Netfilter queue connection handle obtained via call to nfq_open()
*
* \return a file descriptor for the netlink connection associated with the
* given queue connection handle. The file descriptor can then be used for
* receiving the queued packets for processing.
*
* This function returns a file descriptor that can be used for communication
* over the netlink connection associated with the given queue connection
* handle.
*/
EXPORT_SYMBOL
int nfq_fd(struct nfq_handle *h)
{
return nfnl_fd(nfq_nfnlh(h));
}
/**
* @}
*/
/**
* \defgroup LibrarySetup Library setup [DEPRECATED]
*
* Library initialisation is made in two steps.
*
* First step is to call nfq_open() to open a NFQUEUE handler.
*
* Second step is to tell the kernel that userspace queueing is handle by
* NFQUEUE for the selected protocol. This is made by calling nfq_unbind_pf()
* and nfq_bind_pf() with protocol information. The idea behind this is to
* enable simultaneously loaded modules to be used for queuing.
*
* Here's a little code snippet that bind with AF_INET:
* \verbatim
h = nfq_open();
if (!h) {
fprintf(stderr, "error during nfq_open()\n");
exit(1);
}
printf("unbinding existing nf_queue handler for AF_INET (if any)\n");
if (nfq_unbind_pf(h, AF_INET) < 0) {
fprintf(stderr, "error during nfq_unbind_pf()\n");
exit(1);
}
printf("binding nfnetlink_queue as nf_queue handler for AF_INET\n");
if (nfq_bind_pf(h, AF_INET) < 0) {
fprintf(stderr, "error during nfq_bind_pf()\n");
exit(1);
}
\endverbatim
* Once this is done, you can setup and use a \link Queue \endlink.
* @{
*/
/**
* nfq_open - open a nfqueue handler
*
* This function obtains a netfilter queue connection handle. When you are
* finished with the handle returned by this function, you should destroy
* it by calling nfq_close(). A new netlink connection is obtained internally
* and associated with the queue connection handle returned.
*
* \return a pointer to a new queue handle or NULL on failure.
*/
EXPORT_SYMBOL
struct nfq_handle *nfq_open(void)
{
struct nfnl_handle *nfnlh = nfnl_open();
struct nfq_handle *qh;
if (!nfnlh)
return NULL;
/* unset netlink sequence tracking by default */
nfnl_unset_sequence_tracking(nfnlh);
qh = nfq_open_nfnl(nfnlh);
if (!qh)
nfnl_close(nfnlh);
return qh;
}
/**
* @}
*/
/**
* nfq_open_nfnl - open a nfqueue handler from a existing nfnetlink handler
* \param nfnlh Netfilter netlink connection handle obtained by calling nfnl_open()
*
* This function obtains a netfilter queue connection handle using an existing
* netlink connection. This function is used internally to implement
* nfq_open(), and should typically not be called directly.
*
* \return a pointer to a new queue handle or NULL on failure.
*/
EXPORT_SYMBOL
struct nfq_handle *nfq_open_nfnl(struct nfnl_handle *nfnlh)
{
struct nfnl_callback pkt_cb = {
.call = __nfq_rcv_pkt,
.attr_count = NFQA_MAX,
};
struct nfq_handle *h;
int err;
h = malloc(sizeof(*h));
if (!h)
return NULL;
memset(h, 0, sizeof(*h));
h->nfnlh = nfnlh;
h->nfnlssh = nfnl_subsys_open(h->nfnlh, NFNL_SUBSYS_QUEUE,
NFQNL_MSG_MAX, 0);
if (!h->nfnlssh) {
/* FIXME: nfq_errno */
goto out_free;
}
pkt_cb.data = h;
err = nfnl_callback_register(h->nfnlssh, NFQNL_MSG_PACKET, &pkt_cb);
if (err < 0) {
nfq_errno = err;
goto out_close;
}
return h;
out_close:
nfnl_subsys_close(h->nfnlssh);
out_free:
free(h);
return NULL;
}
/**
* \addtogroup LibrarySetup
*
* When the program has finished with libnetfilter_queue, it has to call
* the nfq_close() function to free all associated resources.
*
* @{
*/
/**
* nfq_close - close a nfqueue handler
* \param h Netfilter queue connection handle obtained via call to nfq_open()
*
* This function closes the nfqueue handler and free associated resources.
*
* \return 0 on success, non-zero on failure.
*/
EXPORT_SYMBOL
int nfq_close(struct nfq_handle *h)
{
int ret;
ret = nfnl_close(h->nfnlh);
if (ret == 0)
free(h);
return ret;
}
/**
* nfq_bind_pf - bind a nfqueue handler to a given protocol family
* \param h Netfilter queue connection handle obtained via call to nfq_open()
* \param pf protocol family to bind to nfqueue handler obtained from nfq_open()
*
* Binds the given queue connection handle to process packets belonging to
* the given protocol family (ie. PF_INET, PF_INET6, etc).
* This call is obsolete, Linux kernels from 3.8 onwards ignore it.
*
* \return integer inferior to 0 in case of failure
*/
EXPORT_SYMBOL
int nfq_bind_pf(struct nfq_handle *h, uint16_t pf)
{
return __build_send_cfg_msg(h, NFQNL_CFG_CMD_PF_BIND, 0, pf);
}
/**
* nfq_unbind_pf - unbind nfqueue handler from a protocol family
* \param h Netfilter queue connection handle obtained via call to nfq_open()
* \param pf protocol family to unbind family from
*
* Unbinds the given queue connection handle from processing packets belonging
* to the given protocol family.
*
* This call is obsolete, Linux kernels from 3.8 onwards ignore it.
*/
EXPORT_SYMBOL
int nfq_unbind_pf(struct nfq_handle *h, uint16_t pf)
{
return __build_send_cfg_msg(h, NFQNL_CFG_CMD_PF_UNBIND, 0, pf);
}
/**
* @}
*/
/**
* \addtogroup Queue
* @{
*/
/**
* nfq_create_queue - create a new queue handle and return it.
*
* \param h Netfilter queue connection handle obtained via call to nfq_open()
* \param num the number of the queue to bind to
* \param cb callback function to call for each queued packet
* \param data custom data to pass to the callback function
*
* \return a nfq_q_handle pointing to the newly created queue
*
* Creates a new queue handle, and returns it. The new queue is identified by
* \b num, and the callback specified by \b cb will be called for each enqueued
* packet. The \b data argument will be passed unchanged to the callback. If
* a queue entry with id \b num already exists,
* this function will return failure and the existing entry is unchanged.
*
* The nfq_callback type is defined in libnetfilter_queue.h as:
* \verbatim
typedef int nfq_callback(struct nfq_q_handle *qh,
struct nfgenmsg *nfmsg,
struct nfq_data *nfad, void *data);
\endverbatim
*
* Parameters:
* - qh The queue handle returned by nfq_create_queue
* - nfmsg message objetc that contains the packet
* - nfad Netlink packet data handle
* - data the value passed to the data parameter of nfq_create_queue
*
* The callback should return < 0 to stop processing.
*/
EXPORT_SYMBOL
struct nfq_q_handle *nfq_create_queue(struct nfq_handle *h, uint16_t num,
nfq_callback *cb, void *data)
{
int ret;
struct nfq_q_handle *qh;
if (find_qh(h, num))
return NULL;
qh = malloc(sizeof(*qh));
if (!qh)
return NULL;
memset(qh, 0, sizeof(*qh));
qh->h = h;
qh->id = num;
qh->cb = cb;
qh->data = data;
ret = __build_send_cfg_msg(h, NFQNL_CFG_CMD_BIND, num, 0);
if (ret < 0) {
nfq_errno = ret;
free(qh);
return NULL;
}
add_qh(qh);
return qh;
}
/**
* @}
*/
/**
* \addtogroup Queue
* @{
*/
/**
* nfq_destroy_queue - destroy a queue handle
* \param qh queue handle that we want to destroy created via nfq_create_queue
*
* Removes the binding for the specified queue handle. This call also unbind
* from the nfqueue handler, so you don't have to call nfq_unbind_pf.
*/
EXPORT_SYMBOL
int nfq_destroy_queue(struct nfq_q_handle *qh)
{
int ret = __build_send_cfg_msg(qh->h, NFQNL_CFG_CMD_UNBIND, qh->id, 0);
if (ret == 0) {
del_qh(qh);
free(qh);
}
return ret;
}
/**
* nfq_handle_packet - handle a packet received from the nfqueue subsystem
* \param h Netfilter queue connection handle obtained via call to nfq_open()
* \param buf data to pass to the callback
* \param len length of packet data in buffer
*
* Triggers an associated callback for the given packet received from the
* queue. Packets can be read from the queue using nfq_fd() and recv(). See
* example code for nfq_fd().
*
* \return 0 on success, non-zero on failure.
*/
EXPORT_SYMBOL
int nfq_handle_packet(struct nfq_handle *h, char *buf, int len)
{
return nfnl_handle_packet(h->nfnlh, buf, len);
}
/**
* nfq_set_mode - set the amount of packet data that nfqueue copies to userspace
* \param qh Netfilter queue handle obtained by call to nfq_create_queue().
* \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 queued
* to the given queue.
*
* - NFQNL_COPY_NONE - noop, do not use it
* - NFQNL_COPY_META - copy only packet metadata
* - NFQNL_COPY_PACKET - copy entire packet
*
* \return -1 on error; >=0 otherwise.
*/
EXPORT_SYMBOL
int nfq_set_mode(struct nfq_q_handle *qh, uint8_t mode, uint32_t range)
{
union {
char buf[NFNL_HEADER_LEN
+NFA_LENGTH(sizeof(struct nfqnl_msg_config_params))];
struct nlmsghdr nmh;
} u;
struct nfqnl_msg_config_params params;
nfnl_fill_hdr(qh->h->nfnlssh, &u.nmh, 0, AF_UNSPEC, qh->id,
NFQNL_MSG_CONFIG, NLM_F_REQUEST|NLM_F_ACK);
params.copy_range = htonl(range);
params.copy_mode = mode;
nfnl_addattr_l(&u.nmh, sizeof(u), NFQA_CFG_PARAMS, ¶ms,
sizeof(params));
return nfnl_query(qh->h->nfnlh, &u.nmh);
}
/**
* nfq_set_queue_flags - set flags (options) for the kernel queue
* \param qh Netfilter queue handle obtained by call to nfq_create_queue().
* \param mask specifies which flag bits to modify
* \param flags bitmask of flags
*
* Existing flags, that you may want to combine, are:
*
* - NFQA_CFG_F_FAIL_OPEN (requires Linux kernel >= 3.6): the kernel will
* accept the packets if the kernel queue gets full. If this flag is not
* set, the default action in this case is to drop packets.
*
* - NFQA_CFG_F_CONNTRACK (requires Linux kernel >= 3.6): the kernel will
* include the Connection Tracking system information.
*
* - NFQA_CFG_F_GSO (requires Linux kernel >= 3.10): the kernel will
* not normalize offload packets, i.e. your application will need to
* be able to handle packets larger than the mtu.
*
* Normalization is expensive, so this flag should always be set.
* Because attributes in netlink messages are limited to 65531 bytes,
* you also need to check the NFQA_CAP_LEN attribute, it contains the
* original size of the captured packet on the kernel side.
* If it is set and differs from the payload length, the packet was
* truncated. This also happens when limiting capture size
* with the NFQNL_COPY_PACKET setting, or when e.g. a local user
* sends a very large packet.
*
* If your application validates checksums (e.g., tcp checksum),
* then you must also check if the NFQA_SKB_INFO attribute is present.
* If it is, you need to test the NFQA_SKB_CSUMNOTREADY bit:
* \verbatim
if (attr[NFQA_SKB_INFO]) {
uint32_t info = ntohl(mnl_attr_get_u32(attr[NFQA_SKB_INFO]));
if (info & NFQA_SKB_CSUMNOTREADY)
validate_checksums = false;
}
\endverbatim
* if this bit is set, the layer 3/4 checksums of the packet appear incorrect,
* but are not (because they will be corrected later by the kernel).
* Please see example/nf-queue.c in the libnetfilter_queue source for more
* details.
*
* - NFQA_CFG_F_UID_GID: the kernel will dump UID and GID of the socket to
* which each packet belongs.
*
* Here's a little code snippet to show how to use this API:
* \verbatim
uint32_t flags = NFQA_CFG_F_FAIL_OPEN;
uint32_t mask = NFQA_CFG_F_FAIL_OPEN;
printf("Enabling fail-open on this q\n");
err = nfq_set_queue_flags(qh, mask, flags);
printf("Disabling fail-open on this q\n");
flags &= ~NFQA_CFG_F_FAIL_OPEN;
err = nfq_set_queue_flags(qh, mask, flags);
\endverbatim
* - NFQA_CFG_F_SECCTX: the kernel will dump security context of the socket to
* which each packet belongs.
*
* \warning
* When fragmentation occurs and NFQA_CFG_F_GSO is NOT set then the kernel
* dumps UID/GID and security context fields only for one fragment. To deal
* with this limitation always set NFQA_CFG_F_GSO.
*
* \return -1 on error with errno set appropriately; =0 otherwise.
*/
EXPORT_SYMBOL
int nfq_set_queue_flags(struct nfq_q_handle *qh, uint32_t mask, uint32_t flags)
{
union {
char buf[NFNL_HEADER_LEN
+NFA_LENGTH(sizeof(mask)
+NFA_LENGTH(sizeof(flags)))];
struct nlmsghdr nmh;
} u;
mask = htonl(mask);
flags = htonl(flags);
nfnl_fill_hdr(qh->h->nfnlssh, &u.nmh, 0, AF_UNSPEC, qh->id,
NFQNL_MSG_CONFIG, NLM_F_REQUEST|NLM_F_ACK);
nfnl_addattr32(&u.nmh, sizeof(u), NFQA_CFG_FLAGS, flags);
nfnl_addattr32(&u.nmh, sizeof(u), NFQA_CFG_MASK, mask);
return nfnl_query(qh->h->nfnlh, &u.nmh);
}
/**
* nfq_set_queue_maxlen - Set kernel queue maximum length parameter
* \param qh Netfilter queue handle obtained by call to nfq_create_queue().
* \param queuelen the length of the queue
*
* Sets the size of the queue in kernel. This fixes the maximum number
* of packets the kernel will store before internally before dropping
* upcoming packets.
*
* \return -1 on error; >=0 otherwise.
*/
EXPORT_SYMBOL
int nfq_set_queue_maxlen(struct nfq_q_handle *qh, uint32_t queuelen)
{
union {
char buf[NFNL_HEADER_LEN
+NFA_LENGTH(sizeof(struct nfqnl_msg_config_params))];
struct nlmsghdr nmh;
} u;
uint32_t queue_maxlen = htonl(queuelen);
nfnl_fill_hdr(qh->h->nfnlssh, &u.nmh, 0, AF_UNSPEC, qh->id,
NFQNL_MSG_CONFIG, NLM_F_REQUEST|NLM_F_ACK);
nfnl_addattr_l(&u.nmh, sizeof(u), NFQA_CFG_QUEUE_MAXLEN, &queue_maxlen,
sizeof(queue_maxlen));
return nfnl_query(qh->h->nfnlh, &u.nmh);
}
/**
* @}
*/
static int __set_verdict(struct nfq_q_handle *qh, uint32_t id,
uint32_t verdict, uint32_t mark, int set_mark,
uint32_t data_len, const unsigned char *data,
enum nfqnl_msg_types type)
{
struct nfqnl_msg_verdict_hdr vh;
union {
char buf[NFNL_HEADER_LEN
+NFA_LENGTH(sizeof(mark))
+NFA_LENGTH(sizeof(vh))];
struct nlmsghdr nmh;
} u;
struct iovec iov[3];
int nvecs;
/* This must be declared here (and not inside the data
* handling block) because the iovec points to this. */
struct nfattr data_attr;
memset(iov, 0, sizeof(iov));
vh.verdict = htonl(verdict);
vh.id = htonl(id);
nfnl_fill_hdr(qh->h->nfnlssh, &u.nmh, 0, AF_UNSPEC, qh->id,
type, NLM_F_REQUEST);
/* add verdict header */
nfnl_addattr_l(&u.nmh, sizeof(u), NFQA_VERDICT_HDR, &vh, sizeof(vh));
if (set_mark)
nfnl_addattr32(&u.nmh, sizeof(u), NFQA_MARK, mark);
iov[0].iov_base = &u.nmh;
iov[0].iov_len = NLMSG_TAIL(&u.nmh) - (void *)&u.nmh;
nvecs = 1;
if (data_len) {
/* The typecast here is to cast away data's const-ness: */
nfnl_build_nfa_iovec(&iov[1], &data_attr, NFQA_PAYLOAD,
data_len, (unsigned char *) data);
nvecs += 2;
/* Add the length of the appended data to the message
* header. The size of the attribute is given in the
* nfa_len field and is set in the nfnl_build_nfa_iovec()
* function. */
u.nmh.nlmsg_len += data_attr.nfa_len;
}
return nfnl_sendiov(qh->h->nfnlh, iov, nvecs, 0);
}
/**
* \addtogroup Queue
* @{
*/
/**
* nfq_set_verdict - issue a verdict on a packet
* \param qh Netfilter queue handle obtained by call to nfq_create_queue().
* \param id ID assigned to packet by netfilter.
* \param verdict verdict to return to netfilter (NF_ACCEPT, NF_DROP)
* \param data_len number of bytes of data pointed to by \b buf
* \param buf the buffer that contains the packet data
*
* Can be obtained by:
* \verbatim
int id;
struct nfqnl_msg_packet_hdr *ph = nfq_get_msg_packet_hdr(tb);
if (ph)
id = ntohl(ph->packet_id);
\endverbatim
*
* Notifies netfilter of the userspace verdict for the given packet. Every
* queued packet _must_ have a verdict specified by userspace, either by
* calling this function, the nfq_set_verdict2() function, or the _batch
* versions of these functions.
*
* \return -1 on error; >= 0 otherwise.
*/
EXPORT_SYMBOL
int nfq_set_verdict(struct nfq_q_handle *qh, uint32_t id,
uint32_t verdict, uint32_t data_len,
const unsigned char *buf)
{
return __set_verdict(qh, id, verdict, 0, 0, data_len, buf,
NFQNL_MSG_VERDICT);
}
/**
* nfq_set_verdict2 - like nfq_set_verdict, but you can set the mark.
* \param qh Netfilter queue handle obtained by call to nfq_create_queue().
* \param id ID assigned to packet by netfilter.
* \param verdict verdict to return to netfilter (NF_ACCEPT, NF_DROP)
* \param mark mark to put on packet
* \param data_len number of bytes of data pointed to by \b buf
* \param buf the buffer that contains the packet data
*/
EXPORT_SYMBOL
int nfq_set_verdict2(struct nfq_q_handle *qh, uint32_t id,
uint32_t verdict, uint32_t mark,
uint32_t data_len, const unsigned char *buf)
{
return __set_verdict(qh, id, verdict, htonl(mark), 1, data_len,
buf, NFQNL_MSG_VERDICT);
}
/**
* nfq_set_verdict_batch - issue verdicts on several packets at once
* \param qh Netfilter queue handle obtained by call to nfq_create_queue().
* \param id maximum ID of the packets that the verdict should be applied to.
* \param verdict verdict to return to netfilter (NF_ACCEPT, NF_DROP)
*
* Unlike nfq_set_verdict, the verdict is applied to all queued packets
* whose packet id is smaller or equal to \b id.
*
* batch support was added in Linux 3.1.
* These functions will fail silently on older kernels.
*/
EXPORT_SYMBOL
int nfq_set_verdict_batch(struct nfq_q_handle *qh, uint32_t id,
uint32_t verdict)
{
return __set_verdict(qh, id, verdict, 0, 0, 0, NULL,
NFQNL_MSG_VERDICT_BATCH);
}
/**
* nfq_set_verdict_batch2 - like nfq_set_verdict_batch, but you can set a mark.
* \param qh Netfilter queue handle obtained by call to nfq_create_queue().
* \param id maximum ID of the packets that the verdict should be applied to.
* \param verdict verdict to return to netfilter (NF_ACCEPT, NF_DROP)
* \param mark mark to put on packet
*/
EXPORT_SYMBOL
int nfq_set_verdict_batch2(struct nfq_q_handle *qh, uint32_t id,
uint32_t verdict, uint32_t mark)
{
return __set_verdict(qh, id, verdict, htonl(mark), 1, 0,
NULL, NFQNL_MSG_VERDICT_BATCH);
}
/**
* nfq_set_verdict_mark - like nfq_set_verdict, but you can set the mark.
* \param qh Netfilter queue handle obtained by call to nfq_create_queue().
* \param id ID assigned to packet by netfilter.
* \param verdict verdict to return to netfilter (NF_ACCEPT, NF_DROP)
* \param mark the mark to put on the packet, in network byte order.
* \param data_len number of bytes of data pointed to by \b buf
* \param buf the buffer that contains the packet data
*
* \return -1 on error; >= 0 otherwise.
*
* This function is deprecated since it is broken, its use is highly
* discouraged. Please, use nfq_set_verdict2 instead.
*/
EXPORT_SYMBOL
int nfq_set_verdict_mark(struct nfq_q_handle *qh, uint32_t id,
uint32_t verdict, uint32_t mark,
uint32_t data_len, const unsigned char *buf)
{
return __set_verdict(qh, id, verdict, mark, 1, data_len, buf,
NFQNL_MSG_VERDICT);
}
/**
* @}
*/
/*************************************************************
* Message parsing functions
*************************************************************/
/**
* \defgroup Parsing Message parsing functions [DEPRECATED]
* @{
*/
/**
* nfqnl_msg_packet_hdr - return the metaheader that wraps the packet
* \param nfad Netlink packet data handle passed to callback function
*
* \return the netfilter queue netlink packet header for the given
* nfq_data argument. Typically, the nfq_data value is passed as the 3rd
* parameter to the callback function set by a call to nfq_create_queue().
*
* The nfqnl_msg_packet_hdr structure is defined in libnetfilter_queue.h as:
*
* \verbatim
struct nfqnl_msg_packet_hdr {
uint32_t packet_id; // unique ID of packet in queue
uint16_t hw_protocol; // hw protocol (network order)
uint8_t hook; // netfilter hook
} __attribute__ ((packed));
\endverbatim
*/
EXPORT_SYMBOL
struct nfqnl_msg_packet_hdr *nfq_get_msg_packet_hdr(struct nfq_data *nfad)
{
return nfnl_get_pointer_to_data(nfad->data, NFQA_PACKET_HDR,
struct nfqnl_msg_packet_hdr);
}
/**
* nfq_get_nfmark - get the packet mark
* \param nfad Netlink packet data handle passed to callback function
*
* \return the netfilter mark currently assigned to the given queued packet.
*/
EXPORT_SYMBOL
uint32_t nfq_get_nfmark(struct nfq_data *nfad)
{
return ntohl(nfnl_get_data(nfad->data, NFQA_MARK, uint32_t));
}
/**
* nfq_get_timestamp - get the packet timestamp
* \param nfad Netlink packet data handle passed to callback function
* \param tv structure to fill with timestamp info
*
* Retrieves the received timestamp when the given queued packet.
*
* \return 0 on success, non-zero on failure.
*/
EXPORT_SYMBOL
int nfq_get_timestamp(struct nfq_data *nfad, struct timeval *tv)
{
struct nfqnl_msg_packet_timestamp *qpt;
qpt = nfnl_get_pointer_to_data(nfad->data, NFQA_TIMESTAMP,
struct nfqnl_msg_packet_timestamp);
if (!qpt)
return -1;
tv->tv_sec = __be64_to_cpu(qpt->sec);
tv->tv_usec = __be64_to_cpu(qpt->usec);
return 0;
}
/**
* nfq_get_indev - get the interface that the packet was received through
* \param nfad Netlink packet data handle passed to callback function
*
* \return The index of the device the queued packet was received via. If the
* returned index is 0, the packet was locally generated or the input
* interface is not known (ie. POSTROUTING?).
*
* \warning all nfq_get_dev() functions return 0 if not set, since linux
* only allows ifindex >= 1, see net/core/dev.c:2600 (in 2.6.13.1)
*/
EXPORT_SYMBOL
uint32_t nfq_get_indev(struct nfq_data *nfad)
{
return ntohl(nfnl_get_data(nfad->data, NFQA_IFINDEX_INDEV, uint32_t));
}
/**
* nfq_get_physindev - get the physical interface that the packet was received
* \param nfad Netlink packet data handle passed to callback function
*
* \return The index of the physical device the queued packet was received via.
* If the returned index is 0, the packet was locally generated or the
* physical input interface is no longer known (ie. POSTROUTING?).
*/
EXPORT_SYMBOL
uint32_t nfq_get_physindev(struct nfq_data *nfad)
{
return ntohl(nfnl_get_data(nfad->data, NFQA_IFINDEX_PHYSINDEV, uint32_t));
}
/**
* nfq_get_outdev - gets the interface that the packet will be routed out
* \param nfad Netlink packet data handle passed to callback function
*
* \return The index of the device the queued packet will be sent out. If the
* returned index is 0, the packet is destined for localhost or the output
* interface is not yet known (ie. PREROUTING?).
*/
EXPORT_SYMBOL
uint32_t nfq_get_outdev(struct nfq_data *nfad)
{
return ntohl(nfnl_get_data(nfad->data, NFQA_IFINDEX_OUTDEV, uint32_t));
}
/**
* nfq_get_physoutdev - get the physical interface that the packet output
* \param nfad Netlink packet data handle passed to callback function
*
* The index of the physical device the queued packet will be sent out.
* If the returned index is 0, the packet is destined for localhost or the
* physical output interface is not yet known (ie. PREROUTING?).
*
* \return The index of physical interface that the packet output will be routed out.
*/
EXPORT_SYMBOL
uint32_t nfq_get_physoutdev(struct nfq_data *nfad)
{
return ntohl(nfnl_get_data(nfad->data, NFQA_IFINDEX_PHYSOUTDEV, uint32_t));
}
/**
* nfq_get_indev_name - get the name of the interface the packet
* was received through
* \param nlif_handle pointer to a nlif interface resolving handle
* \param nfad Netlink packet data handle passed to callback function
* \param name pointer to the buffer to receive the interface name;
* not more than \c IFNAMSIZ bytes will be copied to it.
* \return -1 in case of error, >0 if it succeed.
*
* To use a nlif_handle, You need first to call nlif_open() and to open
* an handler. Don't forget to store the result as it will be used
* during all your program life:
* \verbatim
h = nlif_open();
if (h == NULL) {
perror("nlif_open");
exit(EXIT_FAILURE);
}
\endverbatim
* Once the handler is open, you need to fetch the interface table at a
* whole via a call to nlif_query.
* \verbatim
nlif_query(h);
\endverbatim
* libnfnetlink is able to update the interface mapping when a new interface
* appears. To do so, you need to call nlif_catch() on the handler after each
* interface related event. The simplest way to get and treat event is to run
* a select() or poll() against the nlif file descriptor. To get this file
* descriptor, you need to use nlif_fd:
* \verbatim
if_fd = nlif_fd(h);
\endverbatim
* Don't forget to close the handler when you don't need the feature anymore:
* \verbatim
nlif_close(h);
\endverbatim
*
*/
EXPORT_SYMBOL
int nfq_get_indev_name(struct nlif_handle *nlif_handle,
struct nfq_data *nfad, char *name)
{
uint32_t ifindex = nfq_get_indev(nfad);
return nlif_index2name(nlif_handle, ifindex, name);
}
/**
* nfq_get_physindev_name - get the name of the physical interface the
* packet was received through
* \param nlif_handle pointer to a nlif interface resolving handle
* \param nfad Netlink packet data handle passed to callback function
* \param name pointer to the buffer to receive the interface name;
* not more than \c IFNAMSIZ bytes will be copied to it.
*
* See nfq_get_indev_name() documentation for nlif_handle usage.
*
* \return -1 in case of error, > 0 if it succeed.
*/
EXPORT_SYMBOL
int nfq_get_physindev_name(struct nlif_handle *nlif_handle,
struct nfq_data *nfad, char *name)
{
uint32_t ifindex = nfq_get_physindev(nfad);
return nlif_index2name(nlif_handle, ifindex, name);
}
/**
* nfq_get_outdev_name - get the name of the physical interface the
* packet will be sent to
* \param nlif_handle pointer to a nlif interface resolving handle
* \param nfad Netlink packet data handle passed to callback function
* \param name pointer to the buffer to receive the interface name;
* not more than \c IFNAMSIZ bytes will be copied to it.
*
* See nfq_get_indev_name() documentation for nlif_handle usage.
*
* \return -1 in case of error, > 0 if it succeed.
*/
EXPORT_SYMBOL
int nfq_get_outdev_name(struct nlif_handle *nlif_handle,
struct nfq_data *nfad, char *name)
{
uint32_t ifindex = nfq_get_outdev(nfad);
return nlif_index2name(nlif_handle, ifindex, name);
}
/**
* nfq_get_physoutdev_name - get the name of the interface the
* packet will be sent to
* \param nlif_handle pointer to a nlif interface resolving handle
* \param nfad Netlink packet data handle passed to callback function
* \param name pointer to the buffer to receive the interface name;
* not more than \c IFNAMSIZ bytes will be copied to it.
*
* See nfq_get_indev_name() documentation for nlif_handle usage.
*
* \return -1 in case of error, > 0 if it succeed.
*/
EXPORT_SYMBOL
int nfq_get_physoutdev_name(struct nlif_handle *nlif_handle,
struct nfq_data *nfad, char *name)
{
uint32_t ifindex = nfq_get_physoutdev(nfad);
return nlif_index2name(nlif_handle, ifindex, name);
}
/**
* nfq_get_packet_hw
*
* get hardware address
*
* \param nfad Netlink packet data handle passed to callback function
*
* Retrieves the hardware address associated with the given queued packet.
* For ethernet packets, the hardware address returned (if any) will be the
* MAC address of the packet source host. The destination MAC address is not
* known until after POSTROUTING and a successful ARP request, so cannot
* currently be retrieved.
*
* The nfqnl_msg_packet_hw structure is defined in libnetfilter_queue.h as:
* \verbatim
struct nfqnl_msg_packet_hw {
uint16_t hw_addrlen;
uint16_t _pad;
uint8_t hw_addr[8];
} __attribute__ ((packed));
\endverbatim
*/
EXPORT_SYMBOL
struct nfqnl_msg_packet_hw *nfq_get_packet_hw(struct nfq_data *nfad)
{
return nfnl_get_pointer_to_data(nfad->data, NFQA_HWADDR,
struct nfqnl_msg_packet_hw);
}
/**
* nfq_get_skbinfo - return the NFQA_SKB_INFO meta information
* \param nfad Netlink packet data handle passed to callback function
*
* This can be used to obtain extra information about a packet by testing
* the returned integer for any of the following bit flags:
*
* - NFQA_SKB_CSUMNOTREADY
* packet header checksums will be computed by hardware later on, i.e.
* tcp/ip checksums in the packet must not be validated, application
* should pretend they are correct.
* - NFQA_SKB_GSO
* packet is an aggregated super-packet. It exceeds device mtu and will
* be (re-)split on transmit by hardware.
* - NFQA_SKB_CSUM_NOTVERIFIED
* packet checksum was not yet verified by the kernel/hardware, for
* example because this is an incoming packet and the NIC does not
* perform checksum validation at hardware level.
*
* \return the skbinfo value
* \sa __nfq_set_queue_flags__(3)
*/
EXPORT_SYMBOL
uint32_t nfq_get_skbinfo(struct nfq_data *nfad)
{
if (!nfnl_attr_present(nfad->data, NFQA_SKB_INFO))
return 0;
return ntohl(nfnl_get_data(nfad->data, NFQA_SKB_INFO, uint32_t));
}
/**
* nfq_get_uid - get the UID of the user the packet belongs to
* \param nfad Netlink packet data handle passed to callback function
* \param uid Set to UID on return
*
* \warning If the NFQA_CFG_F_GSO flag is not set, then fragmented packets
* may be pushed into the queue. In this case, only one fragment will have the
* UID field set. To deal with this issue always set NFQA_CFG_F_GSO.
*
* \return 1 if there is a UID available, 0 otherwise.
*/
EXPORT_SYMBOL
int nfq_get_uid(struct nfq_data *nfad, uint32_t *uid)
{
if (!nfnl_attr_present(nfad->data, NFQA_UID))
return 0;
*uid = ntohl(nfnl_get_data(nfad->data, NFQA_UID, uint32_t));
return 1;
}
/**
* nfq_get_gid - get the GID of the user the packet belongs to
* \param nfad Netlink packet data handle passed to callback function
* \param gid Set to GID on return
*
* \warning If the NFQA_CFG_F_GSO flag is not set, then fragmented packets
* may be pushed into the queue. In this case, only one fragment will have the
* GID field set. To deal with this issue always set NFQA_CFG_F_GSO.
*
* \return 1 if there is a GID available, 0 otherwise.
*/
EXPORT_SYMBOL
int nfq_get_gid(struct nfq_data *nfad, uint32_t *gid)
{
if (!nfnl_attr_present(nfad->data, NFQA_GID))
return 0;
*gid = ntohl(nfnl_get_data(nfad->data, NFQA_GID, uint32_t));
return 1;
}
/**
* nfq_get_secctx - get the security context for this packet
* \param nfad Netlink packet data handle passed to callback function
* \param secdata data to write the security context to
*
* \warning If the NFQA_CFG_F_GSO flag is not set, then fragmented packets
* may be pushed into the queue. In this case, only one fragment will have the
* SECCTX field set. To deal with this issue always set NFQA_CFG_F_GSO.
*
* \return -1 on error, otherwise > 0
*/
EXPORT_SYMBOL
int nfq_get_secctx(struct nfq_data *nfad, unsigned char **secdata)
{
if (!nfnl_attr_present(nfad->data, NFQA_SECCTX))
return -1;
*secdata = (unsigned char *)nfnl_get_pointer_to_data(nfad->data,
NFQA_SECCTX, char);
if (*secdata)
return NFA_PAYLOAD(nfad->data[NFQA_SECCTX-1]);
return 0;
}
/**
* nfq_get_payload - get payload
* \param nfad Netlink packet data handle passed to callback function
* \param data Pointer of pointer that will be pointed to the payload
*
* Retrieve the payload for a queued packet. The actual amount and type of
* data retrieved by this function will depend on the mode set with the
* nfq_set_mode() function.
*
* \return -1 on error, otherwise > 0.
*/
EXPORT_SYMBOL
int nfq_get_payload(struct nfq_data *nfad, unsigned char **data)
{
*data = (unsigned char *)
nfnl_get_pointer_to_data(nfad->data, NFQA_PAYLOAD, char);
if (*data)
return NFA_PAYLOAD(nfad->data[NFQA_PAYLOAD-1]);
return -1;
}
/**
* @}
*/
#define SNPRINTF_FAILURE(ret, rem, offset, len) \
do { \
if (ret < 0) \
return ret; \
len += ret; \
if (ret > rem) \
ret = rem; \
offset += ret; \
rem -= ret; \
} while (0)
/**
* \defgroup Printing Printing [DEPRECATED]
* @{
*/
/**
* nfq_snprintf_xml - print the enqueued packet in XML format into a buffer
* \param buf The buffer that you want to use to print the logged packet
* \param rem The size of the buffer that you have passed
* \param tb Netlink packet data handle passed to callback function
* \param flags The flag that tell what to print into the buffer
*
* This function supports the following flags:
*
* - NFQ_XML_HW: include the hardware link layer address
* - NFQ_XML_MARK: include the packet mark
* - NFQ_XML_DEV: include the device information
* - NFQ_XML_PHYSDEV: include the physical device information
* - NFQ_XML_PAYLOAD: include the payload (in hexadecimal)
* - NFQ_XML_TIME: include the timestamp
* - NFQ_XML_ALL: include all the logging information (all flags set)
*
* You can combine this flags with an binary OR.
*
* \return -1 in case of failure, otherwise the length of the string that
* would have been printed into the buffer (in case that there is enough
* room in it). See snprintf() return value for more information.
*/
EXPORT_SYMBOL
int nfq_snprintf_xml(char *buf, size_t rem, struct nfq_data *tb, int flags)
{
struct nfqnl_msg_packet_hdr *ph;
struct nfqnl_msg_packet_hw *hwph;
uint32_t mark, ifi;
uint32_t uid, gid;
int size, offset = 0, len = 0, ret;
unsigned char *data;
size = snprintf(buf + offset, rem, "<pkt>");
SNPRINTF_FAILURE(size, rem, offset, len);
if (flags & NFQ_XML_TIME) {
time_t t;
struct tm tm;
t = time(NULL);
if (localtime_r(&t, &tm) == NULL)
return -1;
size = snprintf(buf + offset, rem, "<when>");
SNPRINTF_FAILURE(size, rem, offset, len);
size = snprintf(buf + offset, rem,
"<hour>%d</hour>", tm.tm_hour);
SNPRINTF_FAILURE(size, rem, offset, len);
size = snprintf(buf + offset,
rem, "<min>%02d</min>", tm.tm_min);
SNPRINTF_FAILURE(size, rem, offset, len);
size = snprintf(buf + offset,
rem, "<sec>%02d</sec>", tm.tm_sec);
SNPRINTF_FAILURE(size, rem, offset, len);
size = snprintf(buf + offset, rem, "<wday>%d</wday>",
tm.tm_wday + 1);
SNPRINTF_FAILURE(size, rem, offset, len);
size = snprintf(buf + offset, rem, "<day>%d</day>", tm.tm_mday);
SNPRINTF_FAILURE(size, rem, offset, len);
size = snprintf(buf + offset, rem, "<month>%d</month>",
tm.tm_mon + 1);
SNPRINTF_FAILURE(size, rem, offset, len);
size = snprintf(buf + offset, rem, "<year>%d</year>",
1900 + tm.tm_year);
SNPRINTF_FAILURE(size, rem, offset, len);
size = snprintf(buf + offset, rem, "</when>");
SNPRINTF_FAILURE(size, rem, offset, len);
}
ph = nfq_get_msg_packet_hdr(tb);
if (ph) {
size = snprintf(buf + offset, rem,
"<hook>%u</hook><id>%u</id>",
ph->hook, ntohl(ph->packet_id));
SNPRINTF_FAILURE(size, rem, offset, len);
hwph = nfq_get_packet_hw(tb);
if (hwph && (flags & NFQ_XML_HW)) {
int i, hlen = ntohs(hwph->hw_addrlen);
size = snprintf(buf + offset, rem, "<hw><proto>%04x"
"</proto>",
ntohs(ph->hw_protocol));
SNPRINTF_FAILURE(size, rem, offset, len);
size = snprintf(buf + offset, rem, "<src>");
SNPRINTF_FAILURE(size, rem, offset, len);
for (i=0; i<hlen; i++) {
size = snprintf(buf + offset, rem, "%02x",
hwph->hw_addr[i]);
SNPRINTF_FAILURE(size, rem, offset, len);
}
size = snprintf(buf + offset, rem, "</src></hw>");
SNPRINTF_FAILURE(size, rem, offset, len);
} else if (flags & NFQ_XML_HW) {
size = snprintf(buf + offset, rem, "<hw><proto>%04x"
"</proto></hw>",
ntohs(ph->hw_protocol));
SNPRINTF_FAILURE(size, rem, offset, len);
}
}
mark = nfq_get_nfmark(tb);
if (mark && (flags & NFQ_XML_MARK)) {
size = snprintf(buf + offset, rem, "<mark>%u</mark>", mark);
SNPRINTF_FAILURE(size, rem, offset, len);
}
ifi = nfq_get_indev(tb);
if (ifi && (flags & NFQ_XML_DEV)) {
size = snprintf(buf + offset, rem, "<indev>%u</indev>", ifi);
SNPRINTF_FAILURE(size, rem, offset, len);
}
ifi = nfq_get_outdev(tb);
if (ifi && (flags & NFQ_XML_DEV)) {
size = snprintf(buf + offset, rem, "<outdev>%u</outdev>", ifi);
SNPRINTF_FAILURE(size, rem, offset, len);
}
ifi = nfq_get_physindev(tb);
if (ifi && (flags & NFQ_XML_PHYSDEV)) {
size = snprintf(buf + offset, rem,
"<physindev>%u</physindev>", ifi);
SNPRINTF_FAILURE(size, rem, offset, len);
}
ifi = nfq_get_physoutdev(tb);
if (ifi && (flags & NFQ_XML_PHYSDEV)) {
size = snprintf(buf + offset, rem,
"<physoutdev>%u</physoutdev>", ifi);
SNPRINTF_FAILURE(size, rem, offset, len);
}
if (nfq_get_uid(tb, &uid) && (flags & NFQ_XML_UID)) {
size = snprintf(buf + offset, rem, "<uid>%u</uid>", uid);
SNPRINTF_FAILURE(size, rem, offset, len);
}
if (nfq_get_gid(tb, &gid) && (flags & NFQ_XML_GID)) {
size = snprintf(buf + offset, rem, "<gid>%u</gid>", gid);
SNPRINTF_FAILURE(size, rem, offset, len);
}
ret = nfq_get_payload(tb, &data);
if (ret >= 0 && (flags & NFQ_XML_PAYLOAD)) {
int i;
size = snprintf(buf + offset, rem, "<payload>");
SNPRINTF_FAILURE(size, rem, offset, len);
for (i=0; i<ret; i++) {
size = snprintf(buf + offset, rem, "%02x",
data[i] & 0xff);
SNPRINTF_FAILURE(size, rem, offset, len);
}
size = snprintf(buf + offset, rem, "</payload>");
SNPRINTF_FAILURE(size, rem, offset, len);
}
size = snprintf(buf + offset, rem, "</pkt>");
SNPRINTF_FAILURE(size, rem, offset, len);
return len;
}
/**
* @}
*/