Changelog: https://git.tcpdump.org/libpcap/blob/104271ba4a14de6743e43bcf87536786d8fddea4:/CHANGES Reviewed by: emaste Obtained from: https://www.tcpdump.org/release/libpcap-1.10.4.tar.gz Sponsored by: The FreeBSD Foundation
794 lines
22 KiB
C
794 lines
22 KiB
C
/*
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* Copyright (c) 2011 Jakub Zawadzki
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote
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* products derived from this software without specific prior written
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* permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifdef HAVE_CONFIG_H
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#include <config.h>
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#endif
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#include "pcap-int.h"
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#include "diag-control.h"
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#ifdef NEED_STRERROR_H
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#include "strerror.h"
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#endif
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#include <errno.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <string.h>
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#include <sys/socket.h>
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#include <arpa/inet.h>
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#include <time.h>
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#include <sys/time.h>
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#include <netinet/in.h>
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#include <linux/types.h>
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#include <linux/netlink.h>
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#include <linux/netfilter.h>
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#include <linux/netfilter/nfnetlink.h>
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#include <linux/netfilter/nfnetlink_log.h>
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#include <linux/netfilter/nfnetlink_queue.h>
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/* NOTE: if your program drops privileges after pcap_activate() it WON'T work with nfqueue.
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* It took me quite some time to debug ;/
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*
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* Sending any data to nfnetlink socket requires CAP_NET_ADMIN privileges,
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* and in nfqueue we need to send verdict reply after recving packet.
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*
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* In tcpdump you can disable dropping privileges with -Z root
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*/
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#include "pcap-netfilter-linux.h"
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#define HDR_LENGTH (NLMSG_LENGTH(NLMSG_ALIGN(sizeof(struct nfgenmsg))))
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#define NFLOG_IFACE "nflog"
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#define NFQUEUE_IFACE "nfqueue"
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typedef enum { OTHER = -1, NFLOG, NFQUEUE } nftype_t;
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/*
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* Private data for capturing on Linux netfilter sockets.
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*/
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struct pcap_netfilter {
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u_int packets_read; /* count of packets read with recvfrom() */
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u_int packets_nobufs; /* ENOBUFS counter */
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};
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static int nfqueue_send_verdict(const pcap_t *handle, uint16_t group_id, u_int32_t id, u_int32_t verdict);
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static int
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netfilter_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user)
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{
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struct pcap_netfilter *handlep = handle->priv;
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register u_char *bp, *ep;
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int count = 0;
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ssize_t len;
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/*
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* Has "pcap_breakloop()" been called?
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*/
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if (handle->break_loop) {
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/*
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* Yes - clear the flag that indicates that it
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* has, and return PCAP_ERROR_BREAK to indicate
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* that we were told to break out of the loop.
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*/
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handle->break_loop = 0;
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return PCAP_ERROR_BREAK;
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}
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len = handle->cc;
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if (len == 0) {
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/*
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* The buffer is empty; refill it.
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*
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* We ignore EINTR, as that might just be due to a signal
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* being delivered - if the signal should interrupt the
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* loop, the signal handler should call pcap_breakloop()
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* to set handle->break_loop (we ignore it on other
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* platforms as well).
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*/
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do {
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len = recv(handle->fd, handle->buffer, handle->bufsize, 0);
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if (handle->break_loop) {
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handle->break_loop = 0;
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return PCAP_ERROR_BREAK;
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}
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if (errno == ENOBUFS)
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handlep->packets_nobufs++;
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} while ((len == -1) && (errno == EINTR || errno == ENOBUFS));
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if (len < 0) {
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pcap_fmt_errmsg_for_errno(handle->errbuf,
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PCAP_ERRBUF_SIZE, errno, "Can't receive packet");
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return PCAP_ERROR;
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}
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bp = (unsigned char *)handle->buffer;
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} else
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bp = handle->bp;
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/*
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* Loop through each message.
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*
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* This assumes that a single buffer of message will have
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* <= INT_MAX packets, so the message count doesn't overflow.
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*/
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ep = bp + len;
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while (bp < ep) {
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const struct nlmsghdr *nlh = (const struct nlmsghdr *) bp;
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uint32_t msg_len;
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nftype_t type = OTHER;
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/*
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* Has "pcap_breakloop()" been called?
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* If so, return immediately - if we haven't read any
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* packets, clear the flag and return PCAP_ERROR_BREAK
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* to indicate that we were told to break out of the loop,
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* otherwise leave the flag set, so that the *next* call
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* will break out of the loop without having read any
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* packets, and return the number of packets we've
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* processed so far.
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*/
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if (handle->break_loop) {
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handle->bp = bp;
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handle->cc = (int)(ep - bp);
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if (count == 0) {
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handle->break_loop = 0;
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return PCAP_ERROR_BREAK;
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} else
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return count;
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}
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/*
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* NLMSG_SPACE(0) might be signed or might be unsigned,
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* depending on whether the kernel defines NLMSG_ALIGNTO
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* as 4, which older kernels do, or as 4U, which newer
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* kernels do.
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*
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* ep - bp is of type ptrdiff_t, which is signed.
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*
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* To squelch warnings, we cast both to size_t, which
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* is unsigned; ep >= bp, so the cast is safe.
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*/
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if ((size_t)(ep - bp) < (size_t)NLMSG_SPACE(0)) {
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/*
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* There's less than one netlink message left
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* in the buffer. Give up.
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*/
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break;
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}
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if (nlh->nlmsg_len < sizeof(struct nlmsghdr) || (u_int)len < nlh->nlmsg_len) {
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snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Message truncated: (got: %zd) (nlmsg_len: %u)", len, nlh->nlmsg_len);
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return -1;
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}
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if (NFNL_SUBSYS_ID(nlh->nlmsg_type) == NFNL_SUBSYS_ULOG &&
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NFNL_MSG_TYPE(nlh->nlmsg_type) == NFULNL_MSG_PACKET)
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type = NFLOG;
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else if (NFNL_SUBSYS_ID(nlh->nlmsg_type) == NFNL_SUBSYS_QUEUE &&
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NFNL_MSG_TYPE(nlh->nlmsg_type) == NFQNL_MSG_PACKET)
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type = NFQUEUE;
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if (type != OTHER) {
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const unsigned char *payload = NULL;
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struct pcap_pkthdr pkth;
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const struct nfgenmsg *nfg = NULL;
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int id = 0;
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if (handle->linktype != DLT_NFLOG) {
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const struct nfattr *payload_attr = NULL;
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if (nlh->nlmsg_len < HDR_LENGTH) {
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snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Malformed message: (nlmsg_len: %u)", nlh->nlmsg_len);
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return -1;
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}
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nfg = NLMSG_DATA(nlh);
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if (nlh->nlmsg_len > HDR_LENGTH) {
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struct nfattr *attr = NFM_NFA(nfg);
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int attr_len = nlh->nlmsg_len - NLMSG_ALIGN(HDR_LENGTH);
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while (NFA_OK(attr, attr_len)) {
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if (type == NFQUEUE) {
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switch (NFA_TYPE(attr)) {
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case NFQA_PACKET_HDR:
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{
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const struct nfqnl_msg_packet_hdr *pkt_hdr = (const struct nfqnl_msg_packet_hdr *) NFA_DATA(attr);
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id = ntohl(pkt_hdr->packet_id);
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break;
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}
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case NFQA_PAYLOAD:
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payload_attr = attr;
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break;
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}
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} else if (type == NFLOG) {
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switch (NFA_TYPE(attr)) {
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case NFULA_PAYLOAD:
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payload_attr = attr;
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break;
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}
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}
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attr = NFA_NEXT(attr, attr_len);
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}
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}
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if (payload_attr) {
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payload = NFA_DATA(payload_attr);
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pkth.len = pkth.caplen = NFA_PAYLOAD(payload_attr);
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}
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} else {
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payload = NLMSG_DATA(nlh);
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pkth.caplen = pkth.len = nlh->nlmsg_len-NLMSG_ALIGN(sizeof(struct nlmsghdr));
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}
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if (payload) {
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/* pkth.caplen = min (payload_len, handle->snapshot); */
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gettimeofday(&pkth.ts, NULL);
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if (handle->fcode.bf_insns == NULL ||
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pcap_filter(handle->fcode.bf_insns, payload, pkth.len, pkth.caplen))
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{
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handlep->packets_read++;
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callback(user, &pkth, payload);
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count++;
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}
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}
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if (type == NFQUEUE) {
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/* XXX, possible responses: NF_DROP, NF_ACCEPT, NF_STOLEN, NF_QUEUE, NF_REPEAT, NF_STOP */
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/* if type == NFQUEUE, handle->linktype is always != DLT_NFLOG,
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so nfg is always initialized to NLMSG_DATA(nlh). */
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if (nfg != NULL)
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nfqueue_send_verdict(handle, ntohs(nfg->res_id), id, NF_ACCEPT);
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}
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}
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msg_len = NLMSG_ALIGN(nlh->nlmsg_len);
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/*
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* If the message length would run past the end of the
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* buffer, truncate it to the remaining space in the
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* buffer.
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*
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* To squelch warnings, we cast ep - bp to uint32_t, which
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* is unsigned and is the type of msg_len; ep >= bp, and
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* len should fit in 32 bits (either it's set from an int
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* or it's set from a recv() call with a buffer size that's
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* an int, and we're assuming either ILP32 or LP64), so
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* the cast is safe.
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*/
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if (msg_len > (uint32_t)(ep - bp))
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msg_len = (uint32_t)(ep - bp);
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bp += msg_len;
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if (count >= max_packets && !PACKET_COUNT_IS_UNLIMITED(max_packets)) {
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handle->bp = bp;
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handle->cc = (int)(ep - bp);
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if (handle->cc < 0)
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handle->cc = 0;
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return count;
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}
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}
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handle->cc = 0;
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return count;
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}
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static int
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netfilter_set_datalink(pcap_t *handle, int dlt)
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{
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handle->linktype = dlt;
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return 0;
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}
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static int
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netfilter_stats_linux(pcap_t *handle, struct pcap_stat *stats)
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{
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struct pcap_netfilter *handlep = handle->priv;
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stats->ps_recv = handlep->packets_read;
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stats->ps_drop = handlep->packets_nobufs;
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stats->ps_ifdrop = 0;
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return 0;
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}
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static int
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netfilter_inject_linux(pcap_t *handle, const void *buf _U_, int size _U_)
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{
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snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
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"Packet injection is not supported on netfilter devices");
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return (-1);
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}
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struct my_nfattr {
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uint16_t nfa_len;
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uint16_t nfa_type;
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void *data;
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};
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static int
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netfilter_send_config_msg(const pcap_t *handle, uint16_t msg_type, int ack, u_int8_t family, u_int16_t res_id, const struct my_nfattr *mynfa)
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{
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char buf[1024] __attribute__ ((aligned));
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memset(buf, 0, sizeof(buf));
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struct nlmsghdr *nlh = (struct nlmsghdr *) buf;
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struct nfgenmsg *nfg = (struct nfgenmsg *) (buf + sizeof(struct nlmsghdr));
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struct sockaddr_nl snl;
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static unsigned int seq_id;
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if (!seq_id)
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DIAG_OFF_NARROWING
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seq_id = time(NULL);
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DIAG_ON_NARROWING
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++seq_id;
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nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nfgenmsg));
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nlh->nlmsg_type = msg_type;
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nlh->nlmsg_flags = NLM_F_REQUEST | (ack ? NLM_F_ACK : 0);
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nlh->nlmsg_pid = 0; /* to kernel */
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nlh->nlmsg_seq = seq_id;
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nfg->nfgen_family = family;
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nfg->version = NFNETLINK_V0;
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nfg->res_id = htons(res_id);
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if (mynfa) {
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struct nfattr *nfa = (struct nfattr *) (buf + NLMSG_ALIGN(nlh->nlmsg_len));
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nfa->nfa_type = mynfa->nfa_type;
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nfa->nfa_len = NFA_LENGTH(mynfa->nfa_len);
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memcpy(NFA_DATA(nfa), mynfa->data, mynfa->nfa_len);
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nlh->nlmsg_len = NLMSG_ALIGN(nlh->nlmsg_len) + NFA_ALIGN(nfa->nfa_len);
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}
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memset(&snl, 0, sizeof(snl));
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snl.nl_family = AF_NETLINK;
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if (sendto(handle->fd, nlh, nlh->nlmsg_len, 0, (struct sockaddr *) &snl, sizeof(snl)) == -1)
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return -1;
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if (!ack)
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return 0;
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/* waiting for reply loop */
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do {
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socklen_t addrlen = sizeof(snl);
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int len;
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/* ignore interrupt system call error */
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do {
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/*
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* The buffer is not so big that its size won't
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* fit into an int.
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*/
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len = (int)recvfrom(handle->fd, buf, sizeof(buf), 0, (struct sockaddr *) &snl, &addrlen);
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} while ((len == -1) && (errno == EINTR));
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if (len <= 0)
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return len;
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if (addrlen != sizeof(snl) || snl.nl_family != AF_NETLINK) {
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errno = EINVAL;
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return -1;
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}
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nlh = (struct nlmsghdr *) buf;
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if (snl.nl_pid != 0 || seq_id != nlh->nlmsg_seq) /* if not from kernel or wrong sequence skip */
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continue;
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while ((u_int)len >= NLMSG_SPACE(0) && NLMSG_OK(nlh, (u_int)len)) {
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if (nlh->nlmsg_type == NLMSG_ERROR || (nlh->nlmsg_type == NLMSG_DONE && nlh->nlmsg_flags & NLM_F_MULTI)) {
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if (nlh->nlmsg_len < NLMSG_ALIGN(sizeof(struct nlmsgerr))) {
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errno = EBADMSG;
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return -1;
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}
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errno = -(*((int *)NLMSG_DATA(nlh)));
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return (errno == 0) ? 0 : -1;
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}
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nlh = NLMSG_NEXT(nlh, len);
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}
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} while (1);
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return -1; /* never here */
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}
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static int
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nflog_send_config_msg(const pcap_t *handle, uint8_t family, u_int16_t group_id, const struct my_nfattr *mynfa)
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{
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return netfilter_send_config_msg(handle, (NFNL_SUBSYS_ULOG << 8) | NFULNL_MSG_CONFIG, 1, family, group_id, mynfa);
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}
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static int
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nflog_send_config_cmd(const pcap_t *handle, uint16_t group_id, u_int8_t cmd, u_int8_t family)
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{
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struct nfulnl_msg_config_cmd msg;
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struct my_nfattr nfa;
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msg.command = cmd;
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nfa.data = &msg;
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nfa.nfa_type = NFULA_CFG_CMD;
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nfa.nfa_len = sizeof(msg);
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return nflog_send_config_msg(handle, family, group_id, &nfa);
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}
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static int
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nflog_send_config_mode(const pcap_t *handle, uint16_t group_id, u_int8_t copy_mode, u_int32_t copy_range)
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{
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struct nfulnl_msg_config_mode msg;
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struct my_nfattr nfa;
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msg.copy_range = htonl(copy_range);
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msg.copy_mode = copy_mode;
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nfa.data = &msg;
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nfa.nfa_type = NFULA_CFG_MODE;
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nfa.nfa_len = sizeof(msg);
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return nflog_send_config_msg(handle, AF_UNSPEC, group_id, &nfa);
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}
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static int
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nfqueue_send_verdict(const pcap_t *handle, uint16_t group_id, u_int32_t id, u_int32_t verdict)
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{
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struct nfqnl_msg_verdict_hdr msg;
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struct my_nfattr nfa;
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msg.id = htonl(id);
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msg.verdict = htonl(verdict);
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nfa.data = &msg;
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nfa.nfa_type = NFQA_VERDICT_HDR;
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nfa.nfa_len = sizeof(msg);
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return netfilter_send_config_msg(handle, (NFNL_SUBSYS_QUEUE << 8) | NFQNL_MSG_VERDICT, 0, AF_UNSPEC, group_id, &nfa);
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}
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static int
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nfqueue_send_config_msg(const pcap_t *handle, uint8_t family, u_int16_t group_id, const struct my_nfattr *mynfa)
|
|
{
|
|
return netfilter_send_config_msg(handle, (NFNL_SUBSYS_QUEUE << 8) | NFQNL_MSG_CONFIG, 1, family, group_id, mynfa);
|
|
}
|
|
|
|
static int
|
|
nfqueue_send_config_cmd(const pcap_t *handle, uint16_t group_id, u_int8_t cmd, u_int16_t pf)
|
|
{
|
|
struct nfqnl_msg_config_cmd msg;
|
|
struct my_nfattr nfa;
|
|
|
|
msg.command = cmd;
|
|
msg.pf = htons(pf);
|
|
|
|
nfa.data = &msg;
|
|
nfa.nfa_type = NFQA_CFG_CMD;
|
|
nfa.nfa_len = sizeof(msg);
|
|
|
|
return nfqueue_send_config_msg(handle, AF_UNSPEC, group_id, &nfa);
|
|
}
|
|
|
|
static int
|
|
nfqueue_send_config_mode(const pcap_t *handle, uint16_t group_id, u_int8_t copy_mode, u_int32_t copy_range)
|
|
{
|
|
struct nfqnl_msg_config_params msg;
|
|
struct my_nfattr nfa;
|
|
|
|
msg.copy_range = htonl(copy_range);
|
|
msg.copy_mode = copy_mode;
|
|
|
|
nfa.data = &msg;
|
|
nfa.nfa_type = NFQA_CFG_PARAMS;
|
|
nfa.nfa_len = sizeof(msg);
|
|
|
|
return nfqueue_send_config_msg(handle, AF_UNSPEC, group_id, &nfa);
|
|
}
|
|
|
|
static int
|
|
netfilter_activate(pcap_t* handle)
|
|
{
|
|
const char *dev = handle->opt.device;
|
|
unsigned short groups[32];
|
|
int group_count = 0;
|
|
nftype_t type = OTHER;
|
|
int i;
|
|
|
|
if (strncmp(dev, NFLOG_IFACE, strlen(NFLOG_IFACE)) == 0) {
|
|
dev += strlen(NFLOG_IFACE);
|
|
type = NFLOG;
|
|
|
|
} else if (strncmp(dev, NFQUEUE_IFACE, strlen(NFQUEUE_IFACE)) == 0) {
|
|
dev += strlen(NFQUEUE_IFACE);
|
|
type = NFQUEUE;
|
|
}
|
|
|
|
if (type != OTHER && *dev == ':') {
|
|
dev++;
|
|
while (*dev) {
|
|
long int group_id;
|
|
char *end_dev;
|
|
|
|
if (group_count == 32) {
|
|
snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
|
|
"Maximum 32 netfilter groups! dev: %s",
|
|
handle->opt.device);
|
|
return PCAP_ERROR;
|
|
}
|
|
|
|
group_id = strtol(dev, &end_dev, 0);
|
|
if (end_dev != dev) {
|
|
if (group_id < 0 || group_id > 65535) {
|
|
snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
|
|
"Netfilter group range from 0 to 65535 (got %ld)",
|
|
group_id);
|
|
return PCAP_ERROR;
|
|
}
|
|
|
|
groups[group_count++] = (unsigned short) group_id;
|
|
dev = end_dev;
|
|
}
|
|
if (*dev != ',')
|
|
break;
|
|
dev++;
|
|
}
|
|
}
|
|
|
|
if (type == OTHER || *dev) {
|
|
snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
|
|
"Can't get netfilter group(s) index from %s",
|
|
handle->opt.device);
|
|
return PCAP_ERROR;
|
|
}
|
|
|
|
/* if no groups, add default: 0 */
|
|
if (!group_count) {
|
|
groups[0] = 0;
|
|
group_count = 1;
|
|
}
|
|
|
|
/*
|
|
* Turn a negative snapshot value (invalid), a snapshot value of
|
|
* 0 (unspecified), or a value bigger than the normal maximum
|
|
* value, into the maximum allowed value.
|
|
*
|
|
* If some application really *needs* a bigger snapshot
|
|
* length, we should just increase MAXIMUM_SNAPLEN.
|
|
*/
|
|
if (handle->snapshot <= 0 || handle->snapshot > MAXIMUM_SNAPLEN)
|
|
handle->snapshot = MAXIMUM_SNAPLEN;
|
|
|
|
/* Initialize some components of the pcap structure. */
|
|
handle->bufsize = 128 + handle->snapshot;
|
|
handle->offset = 0;
|
|
handle->read_op = netfilter_read_linux;
|
|
handle->inject_op = netfilter_inject_linux;
|
|
handle->setfilter_op = install_bpf_program; /* no kernel filtering */
|
|
handle->setdirection_op = NULL;
|
|
handle->set_datalink_op = netfilter_set_datalink;
|
|
handle->getnonblock_op = pcap_getnonblock_fd;
|
|
handle->setnonblock_op = pcap_setnonblock_fd;
|
|
handle->stats_op = netfilter_stats_linux;
|
|
|
|
/* Create netlink socket */
|
|
handle->fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_NETFILTER);
|
|
if (handle->fd < 0) {
|
|
pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
|
|
errno, "Can't create raw socket");
|
|
return PCAP_ERROR;
|
|
}
|
|
|
|
if (type == NFLOG) {
|
|
handle->linktype = DLT_NFLOG;
|
|
handle->dlt_list = (u_int *) malloc(sizeof(u_int) * 2);
|
|
if (handle->dlt_list != NULL) {
|
|
handle->dlt_list[0] = DLT_NFLOG;
|
|
handle->dlt_list[1] = DLT_IPV4;
|
|
handle->dlt_count = 2;
|
|
}
|
|
|
|
} else
|
|
handle->linktype = DLT_IPV4;
|
|
|
|
handle->buffer = malloc(handle->bufsize);
|
|
if (!handle->buffer) {
|
|
pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
|
|
errno, "Can't allocate dump buffer");
|
|
goto close_fail;
|
|
}
|
|
|
|
if (type == NFLOG) {
|
|
if (nflog_send_config_cmd(handle, 0, NFULNL_CFG_CMD_PF_UNBIND, AF_INET) < 0) {
|
|
pcap_fmt_errmsg_for_errno(handle->errbuf,
|
|
PCAP_ERRBUF_SIZE, errno,
|
|
"NFULNL_CFG_CMD_PF_UNBIND");
|
|
goto close_fail;
|
|
}
|
|
|
|
if (nflog_send_config_cmd(handle, 0, NFULNL_CFG_CMD_PF_BIND, AF_INET) < 0) {
|
|
pcap_fmt_errmsg_for_errno(handle->errbuf,
|
|
PCAP_ERRBUF_SIZE, errno, "NFULNL_CFG_CMD_PF_BIND");
|
|
goto close_fail;
|
|
}
|
|
|
|
/* Bind socket to the nflog groups */
|
|
for (i = 0; i < group_count; i++) {
|
|
if (nflog_send_config_cmd(handle, groups[i], NFULNL_CFG_CMD_BIND, AF_UNSPEC) < 0) {
|
|
pcap_fmt_errmsg_for_errno(handle->errbuf,
|
|
PCAP_ERRBUF_SIZE, errno,
|
|
"Can't listen on group index");
|
|
goto close_fail;
|
|
}
|
|
|
|
if (nflog_send_config_mode(handle, groups[i], NFULNL_COPY_PACKET, handle->snapshot) < 0) {
|
|
pcap_fmt_errmsg_for_errno(handle->errbuf,
|
|
PCAP_ERRBUF_SIZE, errno,
|
|
"NFULNL_COPY_PACKET");
|
|
goto close_fail;
|
|
}
|
|
}
|
|
|
|
} else {
|
|
if (nfqueue_send_config_cmd(handle, 0, NFQNL_CFG_CMD_PF_UNBIND, AF_INET) < 0) {
|
|
pcap_fmt_errmsg_for_errno(handle->errbuf,
|
|
PCAP_ERRBUF_SIZE, errno, "NFQNL_CFG_CMD_PF_UNBIND");
|
|
goto close_fail;
|
|
}
|
|
|
|
if (nfqueue_send_config_cmd(handle, 0, NFQNL_CFG_CMD_PF_BIND, AF_INET) < 0) {
|
|
pcap_fmt_errmsg_for_errno(handle->errbuf,
|
|
PCAP_ERRBUF_SIZE, errno, "NFQNL_CFG_CMD_PF_BIND");
|
|
goto close_fail;
|
|
}
|
|
|
|
/* Bind socket to the nfqueue groups */
|
|
for (i = 0; i < group_count; i++) {
|
|
if (nfqueue_send_config_cmd(handle, groups[i], NFQNL_CFG_CMD_BIND, AF_UNSPEC) < 0) {
|
|
pcap_fmt_errmsg_for_errno(handle->errbuf,
|
|
PCAP_ERRBUF_SIZE, errno,
|
|
"Can't listen on group index");
|
|
goto close_fail;
|
|
}
|
|
|
|
if (nfqueue_send_config_mode(handle, groups[i], NFQNL_COPY_PACKET, handle->snapshot) < 0) {
|
|
pcap_fmt_errmsg_for_errno(handle->errbuf,
|
|
PCAP_ERRBUF_SIZE, errno,
|
|
"NFQNL_COPY_PACKET");
|
|
goto close_fail;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (handle->opt.rfmon) {
|
|
/*
|
|
* Monitor mode doesn't apply to netfilter devices.
|
|
*/
|
|
pcap_cleanup_live_common(handle);
|
|
return PCAP_ERROR_RFMON_NOTSUP;
|
|
}
|
|
|
|
if (handle->opt.buffer_size != 0) {
|
|
/*
|
|
* Set the socket buffer size to the specified value.
|
|
*/
|
|
if (setsockopt(handle->fd, SOL_SOCKET, SO_RCVBUF, &handle->opt.buffer_size, sizeof(handle->opt.buffer_size)) == -1) {
|
|
pcap_fmt_errmsg_for_errno(handle->errbuf,
|
|
PCAP_ERRBUF_SIZE, errno, "SO_RCVBUF");
|
|
goto close_fail;
|
|
}
|
|
}
|
|
|
|
handle->selectable_fd = handle->fd;
|
|
return 0;
|
|
|
|
close_fail:
|
|
pcap_cleanup_live_common(handle);
|
|
return PCAP_ERROR;
|
|
}
|
|
|
|
pcap_t *
|
|
netfilter_create(const char *device, char *ebuf, int *is_ours)
|
|
{
|
|
const char *cp;
|
|
pcap_t *p;
|
|
|
|
/* Does this look like an netfilter device? */
|
|
cp = strrchr(device, '/');
|
|
if (cp == NULL)
|
|
cp = device;
|
|
|
|
/* Does it begin with NFLOG_IFACE or NFQUEUE_IFACE? */
|
|
if (strncmp(cp, NFLOG_IFACE, sizeof NFLOG_IFACE - 1) == 0)
|
|
cp += sizeof NFLOG_IFACE - 1;
|
|
else if (strncmp(cp, NFQUEUE_IFACE, sizeof NFQUEUE_IFACE - 1) == 0)
|
|
cp += sizeof NFQUEUE_IFACE - 1;
|
|
else {
|
|
/* Nope, doesn't begin with NFLOG_IFACE nor NFQUEUE_IFACE */
|
|
*is_ours = 0;
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Yes - is that either the end of the name, or is it followed
|
|
* by a colon?
|
|
*/
|
|
if (*cp != ':' && *cp != '\0') {
|
|
/* Nope */
|
|
*is_ours = 0;
|
|
return NULL;
|
|
}
|
|
|
|
/* OK, it's probably ours. */
|
|
*is_ours = 1;
|
|
|
|
p = PCAP_CREATE_COMMON(ebuf, struct pcap_netfilter);
|
|
if (p == NULL)
|
|
return (NULL);
|
|
|
|
p->activate_op = netfilter_activate;
|
|
return (p);
|
|
}
|
|
|
|
int
|
|
netfilter_findalldevs(pcap_if_list_t *devlistp, char *err_str)
|
|
{
|
|
int sock;
|
|
|
|
sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_NETFILTER);
|
|
if (sock < 0) {
|
|
/* if netlink is not supported this is not fatal */
|
|
if (errno == EAFNOSUPPORT || errno == EPROTONOSUPPORT)
|
|
return 0;
|
|
pcap_fmt_errmsg_for_errno(err_str, PCAP_ERRBUF_SIZE,
|
|
errno, "Can't open netlink socket");
|
|
return -1;
|
|
}
|
|
close(sock);
|
|
|
|
/*
|
|
* The notion of "connected" vs. "disconnected" doesn't apply.
|
|
* XXX - what about "up" and "running"?
|
|
*/
|
|
if (add_dev(devlistp, NFLOG_IFACE,
|
|
PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE,
|
|
"Linux netfilter log (NFLOG) interface", err_str) == NULL)
|
|
return -1;
|
|
if (add_dev(devlistp, NFQUEUE_IFACE,
|
|
PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE,
|
|
"Linux netfilter queue (NFQUEUE) interface", err_str) == NULL)
|
|
return -1;
|
|
return 0;
|
|
}
|