From 843ba20a46fee91f6e3e270dd6a4266bb3876174 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Sun, 7 Nov 2010 20:38:31 +0100 Subject: examples: add nflog example Signed-off-by: Pablo Neira Ayuso --- examples/netfilter/Makefile.am | 4 + examples/netfilter/nf-log.c | 229 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 233 insertions(+) create mode 100644 examples/netfilter/nf-log.c (limited to 'examples') diff --git a/examples/netfilter/Makefile.am b/examples/netfilter/Makefile.am index 927eb38..96466e0 100644 --- a/examples/netfilter/Makefile.am +++ b/examples/netfilter/Makefile.am @@ -1,10 +1,14 @@ include $(top_srcdir)/Make_global.am check_PROGRAMS = nf-queue \ + nf-log \ nfct-event nf_queue_SOURCES = nf-queue.c nf_queue_LDADD = ../../src/libmnl.la +nf_log_SOURCES = nf-log.c +nf_log_LDADD = ../../src/libmnl.la + nfct_event_SOURCES = nfct-event.c nfct_event_LDADD = ../../src/libmnl.la diff --git a/examples/netfilter/nf-log.c b/examples/netfilter/nf-log.c new file mode 100644 index 0000000..8f0a877 --- /dev/null +++ b/examples/netfilter/nf-log.c @@ -0,0 +1,229 @@ +/* + * (C) 2010 by Pablo Neira Ayuso + * + * This software may be used and distributed according to the terms + * of the GNU General Public License, incorporated herein by reference. + */ +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#ifndef aligned_be64 +#define aligned_be64 u_int64_t __attribute__((aligned(8))) +#endif + +#include + +static int 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, NFULA_MAX) < 0) + return MNL_CB_OK; + + switch(type) { + case NFULA_MARK: + case NFULA_IFINDEX_INDEV: + case NFULA_IFINDEX_OUTDEV: + case NFULA_IFINDEX_PHYSINDEV: + case NFULA_IFINDEX_PHYSOUTDEV: + if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) { + perror("mnl_attr_validate"); + return MNL_CB_ERROR; + } + break; + case NFULA_TIMESTAMP: + if (mnl_attr_validate2(attr, MNL_TYPE_UNSPEC, + sizeof(struct nfulnl_msg_packet_timestamp)) < 0) { + perror("mnl_attr_validate"); + return MNL_CB_ERROR; + } + break; + case NFULA_HWADDR: + if (mnl_attr_validate2(attr, MNL_TYPE_UNSPEC, + sizeof(struct nfulnl_msg_packet_hw)) < 0) { + perror("mnl_attr_validate"); + return MNL_CB_ERROR; + } + break; + case NFULA_PREFIX: + if (mnl_attr_validate(attr, MNL_TYPE_NUL_STRING) < 0) { + perror("mnl_attr_validate"); + return MNL_CB_ERROR; + } + break; + case NFULA_PAYLOAD: + break; + } + tb[type] = attr; + return MNL_CB_OK; +} + +static int log_cb(const struct nlmsghdr *nlh, void *data) +{ + struct nlattr *tb[NFULA_MAX+1] = {}; + struct nfulnl_msg_packet_hdr *ph = NULL; + const char *prefix = NULL; + uint32_t mark = 0; + + mnl_attr_parse(nlh, sizeof(struct nfgenmsg), parse_attr_cb, tb); + if (tb[NFULA_PACKET_HDR]) + ph = mnl_attr_get_payload(tb[NFULA_PACKET_HDR]); + if (tb[NFULA_PREFIX]) + prefix = mnl_attr_get_str(tb[NFULA_PREFIX]); + if (tb[NFULA_MARK]) + mark = ntohl(mnl_attr_get_u32(tb[NFULA_MARK])); + + printf("log received (prefix=\"%s\" hw=0x%04x hook=%u mark=%u)\n", + prefix ? prefix : "", ntohs(ph->hw_protocol), ph->hook, + mark); + + return MNL_CB_OK; +} + +static struct nlmsghdr * +nflog_build_cfg_pf_request(char *buf, uint8_t command) +{ + struct nlmsghdr *nlh = mnl_nlmsg_put_header(buf); + nlh->nlmsg_type = (NFNL_SUBSYS_ULOG << 8) | NFULNL_MSG_CONFIG; + nlh->nlmsg_flags = NLM_F_REQUEST; + + struct nfgenmsg *nfg = mnl_nlmsg_put_extra_header(nlh, sizeof(*nfg)); + nfg->nfgen_family = AF_INET; + nfg->version = NFNETLINK_V0; + + struct nfulnl_msg_config_cmd cmd = { + .command = command, + }; + mnl_attr_put(nlh, NFULA_CFG_CMD, sizeof(cmd), &cmd); + + return nlh; +} + +static struct nlmsghdr * +nflog_build_cfg_request(char *buf, uint8_t command, int qnum) +{ + struct nlmsghdr *nlh = mnl_nlmsg_put_header(buf); + nlh->nlmsg_type = (NFNL_SUBSYS_ULOG << 8) | NFULNL_MSG_CONFIG; + nlh->nlmsg_flags = NLM_F_REQUEST; + + struct nfgenmsg *nfg = mnl_nlmsg_put_extra_header(nlh, sizeof(*nfg)); + nfg->nfgen_family = AF_INET; + nfg->version = NFNETLINK_V0; + nfg->res_id = htons(qnum); + + struct nfulnl_msg_config_cmd cmd = { + .command = command, + }; + mnl_attr_put(nlh, NFULA_CFG_CMD, sizeof(cmd), &cmd); + + return nlh; +} + +static struct nlmsghdr * +nflog_build_cfg_params(char *buf, uint8_t mode, int range, int qnum) +{ + struct nlmsghdr *nlh = mnl_nlmsg_put_header(buf); + nlh->nlmsg_type = (NFNL_SUBSYS_ULOG << 8) | NFULNL_MSG_CONFIG; + nlh->nlmsg_flags = NLM_F_REQUEST; + + struct nfgenmsg *nfg = mnl_nlmsg_put_extra_header(nlh, sizeof(*nfg)); + nfg->nfgen_family = AF_UNSPEC; + nfg->version = NFNETLINK_V0; + nfg->res_id = htons(qnum); + + struct nfulnl_msg_config_mode params = { + .copy_range = htonl(range), + .copy_mode = mode, + }; + mnl_attr_put(nlh, NFULA_CFG_MODE, sizeof(params), ¶ms); + + return nlh; +} + +int main(int argc, char *argv[]) +{ + struct mnl_socket *nl; + char buf[MNL_SOCKET_BUFFER_SIZE]; + struct nlmsghdr *nlh; + int ret; + unsigned int portid, qnum; + + if (argc != 2) { + printf("Usage: %s [queue_num]\n", argv[0]); + exit(EXIT_FAILURE); + } + qnum = atoi(argv[1]); + + nl = mnl_socket_open(NETLINK_NETFILTER); + if (nl == NULL) { + perror("mnl_socket_open"); + exit(EXIT_FAILURE); + } + + if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) { + perror("mnl_socket_bind"); + exit(EXIT_FAILURE); + } + portid = mnl_socket_get_portid(nl); + + nlh = nflog_build_cfg_pf_request(buf, NFULNL_CFG_CMD_PF_UNBIND); + + if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) { + perror("mnl_socket_send"); + exit(EXIT_FAILURE); + } + + nlh = nflog_build_cfg_pf_request(buf, NFULNL_CFG_CMD_PF_BIND); + + if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) { + perror("mnl_socket_send"); + exit(EXIT_FAILURE); + } + + nlh = nflog_build_cfg_request(buf, NFULNL_CFG_CMD_BIND, qnum); + + if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) { + perror("mnl_socket_send"); + exit(EXIT_FAILURE); + } + + nlh = nflog_build_cfg_params(buf, NFULNL_COPY_PACKET, 0xFFFF, qnum); + + if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) { + perror("mnl_socket_send"); + exit(EXIT_FAILURE); + } + + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + if (ret == -1) { + perror("mnl_socket_recvfrom"); + exit(EXIT_FAILURE); + } + while (ret > 0) { + ret = mnl_cb_run(buf, ret, 0, portid, log_cb, NULL); + if (ret < 0){ + perror("mnl_cb_run"); + exit(EXIT_FAILURE); + } + + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + if (ret == -1) { + perror("mnl_socket_recvfrom"); + exit(EXIT_FAILURE); + } + } + + mnl_socket_close(nl); + + return 0; +} -- cgit v1.2.3