From a0c885ae5a79457aa592cb70c27a7dee619762a4 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Mon, 16 Apr 2012 19:12:58 +0200 Subject: add new libnetfilter_queue API for libmnl Signed-off-by: Pablo Neira Ayuso --- src/nlmsg.c | 174 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 174 insertions(+) create mode 100644 src/nlmsg.c (limited to 'src/nlmsg.c') diff --git a/src/nlmsg.c b/src/nlmsg.c new file mode 100644 index 0000000..4637fd5 --- /dev/null +++ b/src/nlmsg.c @@ -0,0 +1,174 @@ +/* + * (C) 2012 by Pablo Neira Ayuso + * + * 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 +#include +#include +#include +#include + +#include + +#ifndef __aligned_be64 +#define __aligned_be64 __be64 __attribute__((aligned(8))) +#define __aligned_le64 __le64 __attribute__((aligned(8))) +#endif + +#include + +#include + +#include "internal.h" + +/** + * \defgroup nfq_verd Queue verdict object handling + * @{ + */ + +void nfq_nlmsg_verdict_put(struct nlmsghdr *nlh, int id, int verdict) +{ + struct nfqnl_msg_verdict_hdr vh = { + .verdict = htonl(verdict), + .id = htonl(id), + }; + mnl_attr_put(nlh, NFQA_VERDICT_HDR, sizeof(vh), &vh); +} +EXPORT_SYMBOL(nfq_nlmsg_verdict_put); + +void nfq_nlmsg_verdict_put_mark(struct nlmsghdr *nlh, uint32_t mark) +{ + mnl_attr_put_u32(nlh, NFQA_MARK, htonl(mark)); +} +EXPORT_SYMBOL(nfq_nlmsg_verdict_put_mark); + +void +nfq_nlmsg_verdict_put_pkt(struct nlmsghdr *nlh, const void *pkt, uint32_t plen) +{ + mnl_attr_put(nlh, NFQA_PAYLOAD, plen, pkt); +} +EXPORT_SYMBOL(nfq_nlmsg_verdict_put_pkt); + +/** + * @} + */ + +/** + * \defgroup nfq_cfg Queue config object handling + * @{ + */ + +/** + * nfq_nlmsg_cfg_build_request- build netlink config message + * \param buf Buffer where netlink message is going to be written. + * \param cfg Structure that contains the config parameters. + * \param command nfqueue nfnetlink command. + * + * This function returns a pointer to the netlink message. If something goes + * wrong it returns NULL. + * + * Possible commands are: + * + * - NFQNL_CFG_CMD_NONE: Do nothing. It can be useful to know if the queue + * subsystem is working. + * - NFQNL_CFG_CMD_BIND: Binds the program to a specific queue. + * - NFQNL_CFG_CMD_UNBIND: Unbinds the program to a specifiq queue. + * - NFQNL_CFG_CMD_PF_BIND: Binds to process packets belonging to the given + * protocol family (ie. PF_INET, PF_INET6, etc). + * - NFQNL_CFG_CMD_PF_UNBIND: Unbinds from processing packets belonging to the + * given protocol family. + */ +void nfq_nlmsg_cfg_put_cmd(struct nlmsghdr *nlh, uint16_t pf, uint8_t cmd) +{ + struct nfqnl_msg_config_cmd command = { + .command = cmd, + .pf = htons(pf), + }; + mnl_attr_put(nlh, NFQA_CFG_CMD, sizeof(command), &command); +} +EXPORT_SYMBOL(nfq_nlmsg_cfg_put_cmd); + +void nfq_nlmsg_cfg_put_params(struct nlmsghdr *nlh, uint8_t mode, int range) +{ + struct nfqnl_msg_config_params params = { + .copy_range = htonl(range), + .copy_mode = mode, + }; + mnl_attr_put(nlh, NFQA_CFG_PARAMS, sizeof(params), ¶ms); +} +EXPORT_SYMBOL(nfq_nlmsg_cfg_put_params); + +void nfq_nlmsg_cfg_put_qmaxlen(struct nlmsghdr *nlh, uint32_t queue_maxlen) +{ + mnl_attr_put_u32(nlh, NFQA_CFG_QUEUE_MAXLEN, htonl(queue_maxlen)); +} +EXPORT_SYMBOL(nfq_nlmsg_cfg_put_qmaxlen); + +/** + * @} + */ + +/** + * \defgroup nlmsg Netlink message helper functions + * @{ + */ + +static int nfq_pkt_parse_attr_cb(const struct nlattr *attr, void *data) +{ + const struct nlattr **tb = data; + int type = mnl_attr_get_type(attr); + + /* skip unsupported attribute in user-space */ + if (mnl_attr_type_valid(attr, NFQA_MAX) < 0) + return MNL_CB_OK; + + switch(type) { + case NFQA_MARK: + case NFQA_IFINDEX_INDEV: + case NFQA_IFINDEX_OUTDEV: + case NFQA_IFINDEX_PHYSINDEV: + case NFQA_IFINDEX_PHYSOUTDEV: + if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) + return MNL_CB_ERROR; + break; + case NFQA_TIMESTAMP: + if (mnl_attr_validate2(attr, MNL_TYPE_UNSPEC, + sizeof(struct nfqnl_msg_packet_timestamp)) < 0) { + return MNL_CB_ERROR; + } + break; + case NFQA_HWADDR: + if (mnl_attr_validate2(attr, MNL_TYPE_UNSPEC, + sizeof(struct nfqnl_msg_packet_hw)) < 0) { + return MNL_CB_ERROR; + } + break; + case NFQA_PAYLOAD: + break; + } + tb[type] = attr; + return MNL_CB_OK; +} + +/** + * nfq_pkt_parse - set packet attributes from netlink message + * \param nlh netlink message that you want to read. + * \param pkt pointer to the packet to set. + * + * This function returns MNL_CB_ERROR if any error occurs, or MNL_CB_OK on + * success. + */ +int nfq_nlmsg_parse(const struct nlmsghdr *nlh, struct nlattr **attr) +{ + return mnl_attr_parse(nlh, sizeof(struct nfgenmsg), + nfq_pkt_parse_attr_cb, attr); +} +EXPORT_SYMBOL(nfq_nlmsg_parse); + +/** + * @} + */ -- cgit v1.2.3