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- /* $Id$ */
- /*
- * Copyright (c) 2001-2010 Aaron Turner <aturner at synfin dot net>
- * Copyright (c) 2013-2018 Fred Klassen <tcpreplay at appneta dot com> - AppNeta
- *
- * The Tcpreplay Suite of tools 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 3 of the
- * License, or with the authors permission any later version.
- *
- * The Tcpreplay Suite 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 the Tcpreplay Suite. If not, see <http://www.gnu.org/licenses/>.
- */
- /*
- * Purpose: Modify packets in a pcap file based on rules provided by the
- * user to offload work from tcpreplay and provide a easier means of
- * reproducing traffic for testing purposes.
- */
- #include "config.h"
- #include "defines.h"
- #include "common.h"
- #include <ctype.h>
- #include <fcntl.h>
- #include <stdio.h>
- #include <stdlib.h>
- #include <string.h>
- #include <sys/types.h>
- #include <unistd.h>
- #include <errno.h>
- #include "tcprewrite.h"
- #include "tcprewrite_opts.h"
- #include "tcpedit/tcpedit.h"
- #include "tcpedit/fuzzing.h"
- #ifdef DEBUG
- int debug;
- #endif
- #ifdef ENABLE_VERBOSE
- /* tcpdump handle */
- tcpdump_t tcpdump;
- #endif
- tcprewrite_opt_t options;
- tcpedit_t *tcpedit;
- /* local functions */
- void tcprewrite_init(void);
- void post_args(int argc, char *argv[]);
- int rewrite_packets(tcpedit_t *tcpedit, pcap_t *pin, pcap_dumper_t *pout);
- int
- main(int argc, char *argv[])
- {
- int optct, rcode;
- pcap_t *dlt_pcap;
- #ifdef ENABLE_FRAGROUTE
- char ebuf[FRAGROUTE_ERRBUF_LEN];
- #endif
- tcprewrite_init();
- /* call autoopts to process arguments */
- optct = optionProcess(&tcprewriteOptions, argc, argv);
- argc -= optct;
- argv += optct;
- /* parse the tcprewrite args */
- post_args(argc, argv);
- /* init tcpedit context */
- if (tcpedit_init(&tcpedit, pcap_datalink(options.pin)) < 0) {
- errx(-1, "Error initializing tcpedit: %s", tcpedit_geterr(tcpedit));
- }
- /* parse the tcpedit args */
- rcode = tcpedit_post_args(tcpedit);
- if (rcode < 0) {
- errx(-1, "Unable to parse args: %s", tcpedit_geterr(tcpedit));
- } else if (rcode == 1) {
- warnx("%s", tcpedit_geterr(tcpedit));
- }
- if (tcpedit_validate(tcpedit) < 0) {
- errx(-1, "Unable to edit packets given options:\n%s",
- tcpedit_geterr(tcpedit));
- }
- /* fuzzing init */
- fuzzing_init(tcpedit->fuzz_seed, tcpedit->fuzz_factor);
- /* open up the output file */
- options.outfile = safe_strdup(OPT_ARG(OUTFILE));
- dbgx(1, "Rewriting DLT to %s",
- pcap_datalink_val_to_name(tcpedit_get_output_dlt(tcpedit)));
- if ((dlt_pcap = pcap_open_dead(tcpedit_get_output_dlt(tcpedit), 65535)) == NULL)
- err(-1, "Unable to open dead pcap handle.");
- dbgx(1, "DLT of dlt_pcap is %s",
- pcap_datalink_val_to_name(pcap_datalink(dlt_pcap)));
- #ifdef ENABLE_FRAGROUTE
- if (options.fragroute_args) {
- if ((options.frag_ctx = fragroute_init(65535, pcap_datalink(dlt_pcap), options.fragroute_args, ebuf)) == NULL)
- errx(-1, "%s", ebuf);
- }
- #endif
- #ifdef ENABLE_VERBOSE
- if (options.verbose) {
- tcpdump_open(&tcpdump, dlt_pcap);
- }
- #endif
- if ((options.pout = pcap_dump_open(dlt_pcap, options.outfile)) == NULL)
- errx(-1, "Unable to open output pcap file: %s", pcap_geterr(dlt_pcap));
- pcap_close(dlt_pcap);
- /* rewrite packets */
- if (rewrite_packets(tcpedit, options.pin, options.pout) != 0)
- errx(-1, "Error rewriting packets: %s", tcpedit_geterr(tcpedit));
- /* clean up after ourselves */
- pcap_dump_close(options.pout);
- pcap_close(options.pin);
- #ifdef ENABLE_VERBOSE
- tcpdump_close(&tcpdump);
- #endif
- #ifdef ENABLE_FRAGROUTE
- if (options.frag_ctx) {
- fragroute_close(options.frag_ctx);
- }
- #endif
- #ifdef ENABLE_DMALLOC
- dmalloc_shutdown();
- #endif
- restore_stdin();
- return 0;
- }
- void
- tcprewrite_init(void)
- {
- memset(&options, 0, sizeof(options));
- #ifdef ENABLE_VERBOSE
- /* clear out tcpdump struct */
- memset(&tcpdump, '\0', sizeof(tcpdump_t));
- #endif
- if (fcntl(STDERR_FILENO, F_SETFL, O_NONBLOCK) < 0)
- warnx("Unable to set STDERR to non-blocking: %s", strerror(errno));
- }
- /**
- * post AutoGen argument processing
- */
- void
- post_args(_U_ int argc, _U_ char *argv[])
- {
- char ebuf[PCAP_ERRBUF_SIZE];
- #ifdef DEBUG
- if (HAVE_OPT(DBUG))
- debug = OPT_VALUE_DBUG;
- #else
- if (HAVE_OPT(DBUG))
- warn("not configured with --enable-debug. Debugging disabled.");
- #endif
- #ifdef ENABLE_VERBOSE
- if (HAVE_OPT(VERBOSE))
- options.verbose = 1;
- if (HAVE_OPT(DECODE))
- tcpdump.args = safe_strdup(OPT_ARG(DECODE));
- #endif
- #ifdef ENABLE_FRAGROUTE
- if (HAVE_OPT(FRAGROUTE))
- options.fragroute_args = safe_strdup(OPT_ARG(FRAGROUTE));
- options.fragroute_dir = FRAGROUTE_DIR_BOTH;
- if (HAVE_OPT(FRAGDIR)) {
- if (strcmp(OPT_ARG(FRAGDIR), "c2s") == 0) {
- options.fragroute_dir = FRAGROUTE_DIR_C2S;
- } else if (strcmp(OPT_ARG(FRAGDIR), "s2c") == 0) {
- options.fragroute_dir = FRAGROUTE_DIR_S2C;
- } else if (strcmp(OPT_ARG(FRAGDIR), "both") == 0) {
- options.fragroute_dir = FRAGROUTE_DIR_BOTH;
- } else {
- errx(-1, "Unknown --fragdir value: %s", OPT_ARG(FRAGDIR));
- }
- }
- #endif
- /* open up the input file */
- options.infile = safe_strdup(OPT_ARG(INFILE));
- if ((options.pin = pcap_open_offline(options.infile, ebuf)) == NULL)
- errx(-1, "Unable to open input pcap file: %s", ebuf);
- #ifdef HAVE_PCAP_SNAPSHOT
- if (pcap_snapshot(options.pin) < 65535)
- warnx("%s was captured using a snaplen of %d bytes. This may mean you have truncated packets.",
- options.infile, pcap_snapshot(options.pin));
- #endif
- }
- /**
- * Main loop to rewrite packets
- */
- int
- rewrite_packets(tcpedit_t *tcpedit, pcap_t *pin, pcap_dumper_t *pout)
- {
- tcpr_dir_t cache_result = TCPR_DIR_C2S; /* default to primary */
- struct pcap_pkthdr pkthdr, *pkthdr_ptr; /* packet header */
- const u_char *pktconst = NULL; /* packet from libpcap */
- u_char **pktdata = NULL;
- static u_char *pktdata_buff;
- static char *frag = NULL;
- COUNTER packetnum = 0;
- int rcode;
- #ifdef ENABLE_FRAGROUTE
- int frag_len, proto;
- #endif
- pkthdr_ptr = &pkthdr;
- if (pktdata_buff == NULL)
- pktdata_buff = (u_char *)safe_malloc(MAXPACKET);
- pktdata = &pktdata_buff;
- if (frag == NULL)
- frag = (char *)safe_malloc(MAXPACKET);
- /* MAIN LOOP
- * Keep sending while we have packets or until
- * we've sent enough packets
- */
- while ((pktconst = safe_pcap_next(pin, pkthdr_ptr)) != NULL) {
- packetnum++;
- dbgx(2, "packet " COUNTER_SPEC " caplen %d", packetnum, pkthdr.caplen);
- if (pkthdr.caplen > MAXPACKET)
- errx(-1, "Frame too big, caplen %d exceeds %d", pkthdr.caplen, MAXPACKET);
- /*
- * copy over the packet so we can pad it out if necessary and
- * because pcap_next() returns a const ptr
- */
- memcpy(*pktdata, pktconst, pkthdr.caplen);
- #ifdef ENABLE_VERBOSE
- if (options.verbose)
- tcpdump_print(&tcpdump, pkthdr_ptr, *pktdata);
- #endif
- /* Dual nic processing? */
- if (options.cachedata != NULL) {
- cache_result = check_cache(options.cachedata, packetnum);
- }
- /* sometimes we should not send the packet, in such cases
- * no point in editing this packet at all, just write it to the
- * output file (note, we can't just remove it, or the tcpprep cache
- * file will loose it's indexing
- */
- if (cache_result == TCPR_DIR_NOSEND)
- goto WRITE_PACKET; /* still need to write it so cache stays in sync */
- if ((rcode = tcpedit_packet(tcpedit, &pkthdr_ptr, pktdata, cache_result)) == TCPEDIT_ERROR) {
- return -1;
- } else if ((rcode == TCPEDIT_SOFT_ERROR) && HAVE_OPT(SKIP_SOFT_ERRORS)) {
- /* don't write packet */
- dbgx(1, "Packet " COUNTER_SPEC " is suppressed from being written due to soft errors", packetnum);
- continue;
- }
- WRITE_PACKET:
- #ifdef ENABLE_FRAGROUTE
- if (options.frag_ctx == NULL) {
- /* write the packet when there's no fragrouting to be done */
- pcap_dump((u_char *)pout, pkthdr_ptr, *pktdata);
- } else {
- /* get the L3 protocol of the packet */
- proto = tcpedit_l3proto(tcpedit, AFTER_PROCESS, *pktdata, pkthdr_ptr->caplen);
- /* packet is IPv4/IPv6 AND needs to be fragmented */
- if ((proto == ETHERTYPE_IP || proto == ETHERTYPE_IP6) &&
- ((options.fragroute_dir == FRAGROUTE_DIR_BOTH) ||
- (cache_result == TCPR_DIR_C2S && options.fragroute_dir == FRAGROUTE_DIR_C2S) ||
- (cache_result == TCPR_DIR_S2C && options.fragroute_dir == FRAGROUTE_DIR_S2C))) {
- #ifdef DEBUG
- int i = 0;
- #endif
- if (fragroute_process(options.frag_ctx, *pktdata, pkthdr_ptr->caplen) < 0)
- errx(-1, "Error processing packet via fragroute: %s", options.frag_ctx->errbuf);
- while ((frag_len = fragroute_getfragment(options.frag_ctx, &frag)) > 0) {
- /* frags get the same timestamp as the original packet */
- dbgx(1, "processing packet " COUNTER_SPEC " frag: %u (%d)", packetnum, i++, frag_len);
- pkthdr_ptr->caplen = frag_len;
- pkthdr_ptr->len = frag_len;
- pcap_dump((u_char *)pout, pkthdr_ptr, (u_char *)frag);
- }
- } else {
- /* write the packet without fragroute */
- pcap_dump((u_char *)pout, pkthdr_ptr, *pktdata);
- }
- }
- #else
- /* write the packet when there's no fragrouting to be done */
- pcap_dump((u_char *)pout, pkthdr_ptr, *pktdata);
- #endif
- } /* while() */
- return 0;
- }
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