+++ /dev/null
-/*-
- * BSD LICENSE
- *
- * Copyright(c) 2010-2012 Intel Corporation. All rights reserved.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * * Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in
- * the documentation and/or other materials provided with the
- * distribution.
- * * Neither the name of Intel Corporation nor the names of its
- * contributors may be used to endorse or promote products derived
- * from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <stdint.h>
-#include <inttypes.h>
-#include <sys/types.h>
-#include <string.h>
-#include <sys/queue.h>
-#include <netinet/in.h>
-#include <setjmp.h>
-#include <stdarg.h>
-#include <ctype.h>
-#include <errno.h>
-#include <getopt.h>
-
-#include <rte_common.h>
-#include <rte_log.h>
-#include <rte_memory.h>
-#include <rte_memcpy.h>
-#include <rte_memzone.h>
-#include <rte_tailq.h>
-#include <rte_eal.h>
-#include <rte_per_lcore.h>
-#include <rte_launch.h>
-#include <rte_atomic.h>
-#include <rte_cycles.h>
-#include <rte_prefetch.h>
-#include <rte_lcore.h>
-#include <rte_per_lcore.h>
-#include <rte_branch_prediction.h>
-#include <rte_interrupts.h>
-#include <rte_pci.h>
-#include <rte_random.h>
-#include <rte_debug.h>
-#include <rte_ether.h>
-#include <rte_ethdev.h>
-#include <rte_ring.h>
-#include <rte_mempool.h>
-#include <rte_mbuf.h>
-
-#include "main.h"
-
-#define RTE_LOGTYPE_L2FWD RTE_LOGTYPE_USER1
-
-#define L2FWD_MAX_PORTS 32
-
-#define MBUF_SIZE (2048 + sizeof(struct rte_mbuf) + RTE_PKTMBUF_HEADROOM)
-#define NB_MBUF 8192
-
-/*
- * RX and TX Prefetch, Host, and Write-back threshold values should be
- * carefully set for optimal performance. Consult the network
- * controller's datasheet and supporting DPDK documentation for guidance
- * on how these parameters should be set.
- */
-#define RX_PTHRESH 8 /**< Default values of RX prefetch threshold reg. */
-#define RX_HTHRESH 8 /**< Default values of RX host threshold reg. */
-#define RX_WTHRESH 4 /**< Default values of RX write-back threshold reg. */
-
-/*
- * These default values are optimized for use with the Intel(R) 82599 10 GbE
- * Controller and the DPDK ixgbe PMD. Consider using other values for other
- * network controllers and/or network drivers.
- */
-#define TX_PTHRESH 36 /**< Default values of TX prefetch threshold reg. */
-#define TX_HTHRESH 0 /**< Default values of TX host threshold reg. */
-#define TX_WTHRESH 0 /**< Default values of TX write-back threshold reg. */
-
-#define MAX_PKT_BURST 32
-#define BURST_TX_DRAIN 200000ULL /* around 100us at 2 Ghz */
-
-#define SOCKET0 0
-
-/*
- * Configurable number of RX/TX ring descriptors
- */
-#define RTE_TEST_RX_DESC_DEFAULT 128
-#define RTE_TEST_TX_DESC_DEFAULT 512
-static uint16_t nb_rxd = RTE_TEST_RX_DESC_DEFAULT;
-static uint16_t nb_txd = RTE_TEST_TX_DESC_DEFAULT;
-
-/* ethernet addresses of ports */
-static struct ether_addr l2fwd_ports_eth_addr[L2FWD_MAX_PORTS];
-
-/* mask of enabled ports */
-static uint32_t l2fwd_enabled_port_mask = 0;
-
-/* list of enabled ports */
-static uint32_t l2fwd_dst_ports[L2FWD_MAX_PORTS];
-
-static unsigned int l2fwd_rx_queue_per_lcore = 1;
-
-#define MAX_PKT_BURST 32
-struct mbuf_table {
- unsigned len;
- struct rte_mbuf *m_table[MAX_PKT_BURST];
-};
-
-#define MAX_RX_QUEUE_PER_LCORE 16
-
-/* Each VF(port) has one Rx/Tx queue (with queueid: 0) */
-struct lcore_queue_conf {
-
- unsigned n_rx_queue;
- unsigned rx_queue_list[MAX_RX_QUEUE_PER_LCORE];
- unsigned tx_queue_id;
- struct mbuf_table tx_mbufs[L2FWD_MAX_PORTS];
-
-} __rte_cache_aligned;
-struct lcore_queue_conf lcore_queue_conf[RTE_MAX_LCORE];
-
-static const struct rte_eth_conf port_conf = {
- .rxmode = {
- .split_hdr_size = 0,
- .header_split = 0, /**< Header Split disabled */
- .hw_ip_checksum = 0, /**< IP checksum offload disabled */
- .hw_vlan_filter = 0, /**< VLAN filtering disabled */
- .jumbo_frame = 0, /**< Jumbo Frame Support disabled */
- .hw_strip_crc = 1, /**< CRC stripped by hardware */
- },
- .txmode = {
- },
-};
-
-static const struct rte_eth_rxconf rx_conf = {
- .rx_thresh = {
- .pthresh = RX_PTHRESH,
- .hthresh = RX_HTHRESH,
- .wthresh = RX_WTHRESH,
- },
-};
-
-static const struct rte_eth_txconf tx_conf = {
- .tx_thresh = {
- .pthresh = TX_PTHRESH,
- .hthresh = TX_HTHRESH,
- .wthresh = TX_WTHRESH,
- },
- .tx_free_thresh = 0, /* Use PMD default values */
- .tx_rs_thresh = 0, /* Use PMD default values */
-};
-
-struct rte_mempool * l2fwd_pktmbuf_pool = NULL;
-
-/* Per-port statistics struct */
-struct l2fwd_port_statistics {
- uint64_t tx;
- uint64_t rx;
- uint64_t dropped;
-} __rte_cache_aligned;
-struct l2fwd_port_statistics port_statistics[L2FWD_MAX_PORTS];
-
-/* A tsc-based timer responsible for triggering statistics printout */
-#define TIMER_MILLISECOND 2000000ULL /* around 1ms at 2 Ghz */
-#define MAX_TIMER_PERIOD 86400 /* 1 day max */
-static int64_t timer_period = 10 * TIMER_MILLISECOND * 1000; /* default period is 10 seconds */
-
-/* Print out statistics on packets dropped */
-static void
-print_stats(void)
-{
- uint64_t total_packets_dropped, total_packets_tx, total_packets_rx;
- unsigned portid;
-
- total_packets_dropped = 0;
- total_packets_tx = 0;
- total_packets_rx = 0;
-
- const char clr[] = { 27, '[', '2', 'J', '\0' };
- const char topLeft[] = { 27, '[', '1', ';', '1', 'H','\0' };
-
- /* Clear screen and move to top left */
- printf("%s%s", clr, topLeft);
-
- printf("\nPort statistics ====================================");
-
- for (portid = 0; portid < L2FWD_MAX_PORTS; portid++) {
- /* skip ports that are not enabled */
- if ((l2fwd_enabled_port_mask & (1 << portid)) == 0)
- continue;
-
- printf("\nStatistics for port %u ------------------------------"
- "\nPackets sent: %24"PRIu64
- "\nPackets received: %20"PRIu64
- "\nPackets dropped: %21"PRIu64,
- portid,
- port_statistics[portid].tx,
- port_statistics[portid].rx,
- port_statistics[portid].dropped);
-
- total_packets_dropped += port_statistics[portid].dropped;
- total_packets_tx += port_statistics[portid].tx;
- total_packets_rx += port_statistics[portid].rx;
- }
- printf("\nAggregate statistics ==============================="
- "\nTotal packets sent: %18"PRIu64
- "\nTotal packets received: %14"PRIu64
- "\nTotal packets dropped: %15"PRIu64,
- total_packets_tx,
- total_packets_rx,
- total_packets_dropped);
- printf("\n====================================================\n");
-}
-
-/* Send the packet on an output interface */
-static int
-l2fwd_send_burst(struct lcore_queue_conf *qconf, unsigned n, uint8_t port)
-{
- struct rte_mbuf **m_table;
- unsigned ret;
- unsigned queueid;
-
- queueid = (uint16_t) qconf->tx_queue_id;
- m_table = (struct rte_mbuf **)qconf->tx_mbufs[port].m_table;
-
- ret = rte_eth_tx_burst(port, (uint16_t) queueid, m_table, (uint16_t) n);
-
- port_statistics[port].tx += ret;
- if (unlikely(ret < n)) {
- port_statistics[port].dropped += (n - ret);
- do {
- rte_pktmbuf_free(m_table[ret]);
- } while (++ret < n);
- }
-
- return 0;
-}
-
-/* Send the packet on an output interface */
-static int
-l2fwd_send_packet(struct rte_mbuf *m, uint8_t port)
-{
- unsigned lcore_id, len;
- struct lcore_queue_conf *qconf;
-
- lcore_id = rte_lcore_id();
-
- qconf = &lcore_queue_conf[lcore_id];
- len = qconf->tx_mbufs[port].len;
- qconf->tx_mbufs[port].m_table[len] = m;
- len++;
-
- /* enough pkts to be sent */
- if (unlikely(len == MAX_PKT_BURST)) {
- l2fwd_send_burst(qconf, MAX_PKT_BURST, port);
- len = 0;
- }
-
- qconf->tx_mbufs[port].len = len;
- return 0;
-}
-
-static void
-l2fwd_simple_forward(struct rte_mbuf *m, unsigned portid)
-{
- struct ether_hdr *eth;
- void *tmp;
- unsigned dst_port;
-
- dst_port = l2fwd_dst_ports[portid];
- eth = rte_pktmbuf_mtod(m, struct ether_hdr *);
-
- /* 00:09:c0:00:00:xx */
- tmp = ð->d_addr.addr_bytes[0];
- *((uint64_t *)tmp) = 0x000000c00900 + (dst_port << 24);
-
- /* src addr */
- ether_addr_copy(&l2fwd_ports_eth_addr[dst_port], ð->s_addr);
-
- l2fwd_send_packet(m, (uint8_t) dst_port);
-}
-
-/* main processing loop */
-static void
-l2fwd_main_loop(void)
-{
- struct rte_mbuf *pkts_burst[MAX_PKT_BURST];
- struct rte_mbuf *m;
- unsigned lcore_id;
- unsigned int nb_ports;
- uint64_t prev_tsc = 0;
- uint64_t diff_tsc, cur_tsc, timer_tsc;
- unsigned i, j, portid, nb_rx;
- struct lcore_queue_conf *qconf;
-
- timer_tsc = 0;
-
- lcore_id = rte_lcore_id();
- qconf = &lcore_queue_conf[lcore_id];
-
- nb_ports = rte_eth_dev_count();
- if (nb_ports > L2FWD_MAX_PORTS)
- nb_ports = L2FWD_MAX_PORTS;
-
- if (qconf->n_rx_queue == 0) {
- RTE_LOG(INFO, L2FWD, "lcore %u has nothing to do\n", lcore_id);
- while(1);
- }
-
- RTE_LOG(INFO, L2FWD, "entering main loop on lcore %u\n", lcore_id);
-
- for (i = 0; i < qconf->n_rx_queue; i++) {
-
- portid = qconf->rx_queue_list[i];
- RTE_LOG(INFO, L2FWD, " -- lcoreid=%u portid=%u\n", lcore_id,
- portid);
- }
-
- while (1) {
-
- cur_tsc = rte_rdtsc();
-
- /*
- * TX burst queue drain
- */
- diff_tsc = cur_tsc - prev_tsc;
- if (unlikely(diff_tsc > BURST_TX_DRAIN)) {
-
- for (portid = 0; portid < nb_ports; portid++) {
- if (qconf->tx_mbufs[portid].len == 0)
- continue;
- l2fwd_send_burst(&lcore_queue_conf[lcore_id],
- qconf->tx_mbufs[portid].len,
- (uint8_t) portid);
- qconf->tx_mbufs[portid].len = 0;
- }
-
- /* if timer is enabled */
- if (timer_period > 0) {
-
- /* advance the timer */
- timer_tsc += diff_tsc;
-
- /* if timer has reached its timeout */
- if (unlikely(timer_tsc >= (uint64_t) timer_period)) {
-
- /* do this only on master core */
- if (lcore_id == rte_get_master_lcore()) {
- print_stats();
- /* reset the timer */
- timer_tsc = 0;
- }
- }
- }
-
- prev_tsc = cur_tsc;
- }
- /*
- * Read packet from RX queues
- */
- for (i = 0; i < qconf->n_rx_queue; i++) {
-
- portid = qconf->rx_queue_list[i];
- nb_rx = rte_eth_rx_burst((uint8_t) portid, 0,
- pkts_burst, MAX_PKT_BURST);
-
- port_statistics[portid].rx += nb_rx;
-
- for (j = 0; j < nb_rx; j++) {
- m = pkts_burst[j];
- rte_prefetch0(rte_pktmbuf_mtod(m, void *));
- l2fwd_simple_forward(m, portid);
- }
- }
- }
-}
-
-static int
-l2fwd_launch_one_lcore(__attribute__((unused)) void *dummy)
-{
- l2fwd_main_loop();
- return 0;
-}
-
-/* display usage */
-static void
-l2fwd_usage(const char *prgname)
-{
- printf("%s [EAL options] -- -p PORTMASK [-q NQ]\n"
- " -p PORTMASK: hexadecimal bitmask of ports to configure\n"
- " -q NQ: number of queue (=ports) per lcore (default is 1)\n"
- " -T PERIOD: statistics will be refreshed each PERIOD seconds (0 to disable, 10 default, 86400 maximum)\n",
- prgname);
-}
-
-static int
-l2fwd_parse_portmask(const char *portmask)
-{
- char *end = NULL;
- unsigned long pm;
-
- /* parse hexadecimal string */
- pm = strtoul(portmask, &end, 16);
- if ((portmask[0] == '\0') || (end == NULL) || (*end != '\0'))
- return -1;
-
- if (pm == 0)
- return -1;
-
- return pm;
-}
-
-static unsigned int
-l2fwd_parse_nqueue(const char *q_arg)
-{
- char *end = NULL;
- unsigned long n;
-
- /* parse hexadecimal string */
- n = strtoul(q_arg, &end, 10);
- if ((q_arg[0] == '\0') || (end == NULL) || (*end != '\0'))
- return 0;
- if (n == 0)
- return 0;
- if (n >= MAX_RX_QUEUE_PER_LCORE)
- return 0;
-
- return n;
-}
-
-static int
-l2fwd_parse_timer_period(const char *q_arg)
-{
- char *end = NULL;
- int n;
-
- /* parse number string */
- n = strtol(q_arg, &end, 10);
- if ((q_arg[0] == '\0') || (end == NULL) || (*end != '\0'))
- return -1;
- if (n >= MAX_TIMER_PERIOD)
- return -1;
-
- return n;
-}
-
-/* Parse the argument given in the command line of the application */
-static int
-l2fwd_parse_args(int argc, char **argv)
-{
- int opt, ret;
- char **argvopt;
- int option_index;
- char *prgname = argv[0];
- static struct option lgopts[] = {
- {NULL, 0, 0, 0}
- };
-
- argvopt = argv;
-
- while ((opt = getopt_long(argc, argvopt, "p:q:T:",
- lgopts, &option_index)) != EOF) {
-
- switch (opt) {
- /* portmask */
- case 'p':
- l2fwd_enabled_port_mask = l2fwd_parse_portmask(optarg);
- if (l2fwd_enabled_port_mask == 0) {
- printf("invalid portmask\n");
- l2fwd_usage(prgname);
- return -1;
- }
- break;
-
- /* nqueue */
- case 'q':
- l2fwd_rx_queue_per_lcore = l2fwd_parse_nqueue(optarg);
- if (l2fwd_rx_queue_per_lcore == 0) {
- printf("invalid queue number\n");
- l2fwd_usage(prgname);
- return -1;
- }
- break;
-
- /* timer period */
- case 'T':
- timer_period = l2fwd_parse_timer_period(optarg) * 1000 * TIMER_MILLISECOND;
- if (timer_period < 0) {
- printf("invalid timer period\n");
- l2fwd_usage(prgname);
- return -1;
- }
- break;
-
- /* long options */
- case 0:
- l2fwd_usage(prgname);
- return -1;
-
- default:
- l2fwd_usage(prgname);
- return -1;
- }
- }
-
- if (optind >= 0)
- argv[optind-1] = prgname;
-
- ret = optind-1;
- optind = 0; /* reset getopt lib */
- return ret;
-}
-
-int
-MAIN(int argc, char **argv)
-{
- struct lcore_queue_conf *qconf;
- int ret;
- unsigned int nb_ports;
- unsigned portid;
- unsigned lcore_id, rx_lcore_id;
- unsigned last_port;
- unsigned nb_ports_in_mask = 0;
-
- /* init EAL */
- ret = rte_eal_init(argc, argv);
- if (ret < 0)
- rte_exit(EXIT_FAILURE, "Invalid EAL parameters\n");
- argc -= ret;
- argv += ret;
-
- /* parse application arguments (after the EAL ones) */
- ret = l2fwd_parse_args(argc, argv);
- if (ret < 0)
- rte_exit(EXIT_FAILURE, "Invalid L2FWD-VF parameters\n");
-
- /* create the mbuf pool */
- l2fwd_pktmbuf_pool =
- rte_mempool_create("mbuf_pool", NB_MBUF,
- MBUF_SIZE, 32,
- sizeof(struct rte_pktmbuf_pool_private),
- rte_pktmbuf_pool_init, NULL,
- rte_pktmbuf_init, NULL,
- SOCKET0, 0);
- if (l2fwd_pktmbuf_pool == NULL)
- rte_exit(EXIT_FAILURE, "Cannot init mbuf pool\n");
-
- /* init driver(s) */
-#ifdef RTE_LIBRTE_IGB_PMD
- if (rte_igb_pmd_init() < 0)
- rte_exit(EXIT_FAILURE, "Cannot init igb pmd\n");
-#endif
-#ifdef RTE_LIBRTE_IXGBE_PMD
- if (rte_ixgbe_pmd_init() < 0)
- rte_exit(EXIT_FAILURE, "Cannot init ixgbe pmd\n");
-
- if (rte_ixgbevf_pmd_init() < 0)
- rte_exit(EXIT_FAILURE, "Cannot init ixgbevf pmd\n");
-#endif
-
- if (rte_eal_pci_probe() < 0)
- rte_exit(EXIT_FAILURE, "Cannot probe PCI\n");
-
- nb_ports = rte_eth_dev_count();
- if (nb_ports == 0)
- rte_exit(EXIT_FAILURE, "No Ethernet port - bye\n");
-
- if (nb_ports > L2FWD_MAX_PORTS)
- nb_ports = L2FWD_MAX_PORTS;
-
- /* reset l2fwd_dst_ports */
- for (portid = 0; portid < L2FWD_MAX_PORTS; portid++)
- l2fwd_dst_ports[portid] = 0;
- last_port = 0;
-
- rx_lcore_id = 0;
- qconf = &lcore_queue_conf[rx_lcore_id];
-
- /*
- * Initialize the lcore/port-rx-queue configuration of each lcore.
- * NOTE: Each logical core sends packets out to all port-tx-queues
- */
- for (portid = 0; portid < nb_ports; portid++) {
-
- /* skip ports that are not enabled */
- if ((l2fwd_enabled_port_mask & (1 << portid)) == 0)
- continue;
-
- if (nb_ports_in_mask % 2) {
- l2fwd_dst_ports[portid] = last_port;
- l2fwd_dst_ports[last_port] = portid;
- }
- else
- last_port = portid;
-
- nb_ports_in_mask++;
-
- while (rte_lcore_is_enabled(rx_lcore_id) == 0 ||
- lcore_queue_conf[rx_lcore_id].n_rx_queue ==
- l2fwd_rx_queue_per_lcore) {
-
- rx_lcore_id++;
- if (rx_lcore_id >= RTE_MAX_LCORE)
- rte_exit(EXIT_FAILURE, "Not enough cores\n");
- }
-
- qconf = &lcore_queue_conf[rx_lcore_id];
- qconf->tx_queue_id = 0;
- qconf->rx_queue_list[qconf->n_rx_queue] = portid;
- qconf->n_rx_queue++;
-
- printf("Lcore %u: RX port %u\n", rx_lcore_id, portid);
-
- }
-
- /* Initialise each port */
- for (portid = 0; portid < nb_ports; portid++) {
-
- /* skip ports that are not enabled */
- if ((l2fwd_enabled_port_mask & (1 << portid)) == 0) {
- printf("Skipping disabled port %u\n", portid);
- continue;
- }
-
- /* init port */
- printf("Initializing port %u... ", portid);
- fflush(stdout);
- ret = rte_eth_dev_configure((uint8_t) portid, 1, 1, &port_conf);
- if (ret < 0)
- rte_exit(EXIT_FAILURE, "Cannot configure device: err=%d, port=%u\n",
- ret, portid);
-
- rte_eth_macaddr_get((uint8_t) portid,
- &l2fwd_ports_eth_addr[portid]);
-
- /* init one RX queue */
- fflush(stdout);
- ret = rte_eth_rx_queue_setup((uint8_t) portid, 0, nb_rxd,
- SOCKET0, &rx_conf,
- l2fwd_pktmbuf_pool);
- if (ret < 0)
- rte_exit(EXIT_FAILURE, "rte_eth_tx_queue_setup: err=%d, port=%u\n",
- ret, portid);
-
- /* init one TX queue */
- fflush(stdout);
- ret = rte_eth_tx_queue_setup((uint8_t) portid, 0, nb_txd,
- SOCKET0, &tx_conf);
- if (ret < 0)
- rte_exit(EXIT_FAILURE, "rte_eth_tx_queue_setup: err=%d, port=%u\n",
- ret, portid);
-
- /* Start device */
- ret = rte_eth_dev_start((uint8_t) portid);
- if (ret < 0)
- rte_exit(EXIT_FAILURE, "rte_eth_dev_start: err=%d, port=%u\n",
- ret, portid);
-
- printf("done: ");
- fflush(stdout);
-
- printf("Port %u, MAC address: %02X:%02X:%02X:%02X:%02X:%02X\n\n",
- portid,
- l2fwd_ports_eth_addr[portid].addr_bytes[0],
- l2fwd_ports_eth_addr[portid].addr_bytes[1],
- l2fwd_ports_eth_addr[portid].addr_bytes[2],
- l2fwd_ports_eth_addr[portid].addr_bytes[3],
- l2fwd_ports_eth_addr[portid].addr_bytes[4],
- l2fwd_ports_eth_addr[portid].addr_bytes[5]);
-
- /* initialize port stats */
- memset(&port_statistics, 0, sizeof(port_statistics));
- }
-
- /* launch per-lcore init on every lcore */
- rte_eal_mp_remote_launch(l2fwd_launch_one_lcore, NULL, CALL_MASTER);
- RTE_LCORE_FOREACH_SLAVE(lcore_id) {
- if (rte_eal_wait_lcore(lcore_id) < 0)
- return -1;
- }
-
- return 0;
-}
git.droids-corp.org / dpdk.git / commitdiff