- /* Written from scratch, but kernel-to-user space API usage
- * dissected from lolpcap:
- * Copyright 2011, Chetan Loke <loke.chetan@gmail.com>
- * License: GPL, version 2.0
- */
- #include <stdio.h>
- #include <stdlib.h>
- #include <stdint.h>
- #include <string.h>
- #include <assert.h>
- #include <net/if.h>
- #include <arpa/inet.h>
- #include <netdb.h>
- #include <poll.h>
- #include <unistd.h>
- #include <signal.h>
- #include <inttypes.h>
- #include <sys/socket.h>
- #include <sys/mman.h>
- #include <linux/if_packet.h>
- #include <linux/if_ether.h>
- #include <linux/ip.h>
- #ifndef likely
- # define likely(x) __builtin_expect(!!(x), 1)
- #endif
- #ifndef unlikely
- # define unlikely(x) __builtin_expect(!!(x), 0)
- #endif
- struct block_desc {
- uint32_t version;
- uint32_t offset_to_priv;
- struct tpacket_hdr_v1 h1;
- };
- struct ring {
- struct iovec *rd;
- uint8_t *map;
- struct tpacket_req3 req;
- };
- static unsigned long packets_total = 0, bytes_total = 0;
- static sig_atomic_t sigint = 0;
- static void sighandler(int num)
- {
- sigint = 1;
- }
- static int setup_socket(struct ring *ring, char *netdev)
- {
- int err, i, fd, v = TPACKET_V3;
- struct sockaddr_ll ll;
- unsigned int blocksiz = 1 << 22, framesiz = 1 << 11;
- unsigned int blocknum = 64;
- fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
- if (fd < 0) {
- perror("socket");
- exit(1);
- }
- err = setsockopt(fd, SOL_PACKET, PACKET_VERSION, &v, sizeof(v));
- if (err < 0) {
- perror("setsockopt");
- exit(1);
- }
- memset(&ring->req, 0, sizeof(ring->req));
- ring->req.tp_block_size = blocksiz;
- ring->req.tp_frame_size = framesiz;
- ring->req.tp_block_nr = blocknum;
- ring->req.tp_frame_nr = (blocksiz * blocknum) / framesiz;
- ring->req.tp_retire_blk_tov = 60;
- ring->req.tp_feature_req_word = TP_FT_REQ_FILL_RXHASH;
- err = setsockopt(fd, SOL_PACKET, PACKET_RX_RING, &ring->req,
- sizeof(ring->req));
- if (err < 0) {
- perror("setsockopt");
- exit(1);
- }
- ring->map = mmap(NULL, ring->req.tp_block_size * ring->req.tp_block_nr,
- PROT_READ | PROT_WRITE, MAP_SHARED | MAP_LOCKED, fd, 0);
- if (ring->map == MAP_FAILED) {
- perror("mmap");
- exit(1);
- }
- ring->rd = malloc(ring->req.tp_block_nr * sizeof(*ring->rd));
- assert(ring->rd);
- for (i = 0; i < ring->req.tp_block_nr; ++i) {
- ring->rd[i].iov_base = ring->map + (i * ring->req.tp_block_size);
- ring->rd[i].iov_len = ring->req.tp_block_size;
- }
- memset(&ll, 0, sizeof(ll));
- ll.sll_family = PF_PACKET;
- ll.sll_protocol = htons(ETH_P_ALL);
- ll.sll_ifindex = if_nametoindex(netdev);
- ll.sll_hatype = 0;
- ll.sll_pkttype = 0;
- ll.sll_halen = 0;
- err = bind(fd, (struct sockaddr *) &ll, sizeof(ll));
- if (err < 0) {
- perror("bind");
- exit(1);
- }
- return fd;
- }
- static void display(struct tpacket3_hdr *ppd)
- {
- struct ethhdr *eth = (struct ethhdr *) ((uint8_t *) ppd + ppd->tp_mac);
- struct iphdr *ip = (struct iphdr *) ((uint8_t *) eth + ETH_HLEN);
- if (eth->h_proto == htons(ETH_P_IP)) {
- struct sockaddr_in ss, sd;
- char sbuff[NI_MAXHOST], dbuff[NI_MAXHOST];
- memset(&ss, 0, sizeof(ss));
- ss.sin_family = PF_INET;
- ss.sin_addr.s_addr = ip->saddr;
- getnameinfo((struct sockaddr *) &ss, sizeof(ss),
- sbuff, sizeof(sbuff), NULL, 0, NI_NUMERICHOST);
- memset(&sd, 0, sizeof(sd));
- sd.sin_family = PF_INET;
- sd.sin_addr.s_addr = ip->daddr;
- getnameinfo((struct sockaddr *) &sd, sizeof(sd),
- dbuff, sizeof(dbuff), NULL, 0, NI_NUMERICHOST);
- printf("%s -> %s, ", sbuff, dbuff);
- }
- printf("rxhash: 0x%x\n", ppd->hv1.tp_rxhash);
- }
- static void walk_block(struct block_desc *pbd, const int block_num)
- {
- int num_pkts = pbd->h1.num_pkts, i;
- unsigned long bytes = 0;
- struct tpacket3_hdr *ppd;
- ppd = (struct tpacket3_hdr *) ((uint8_t *) pbd +
- pbd->h1.offset_to_first_pkt);
- for (i = 0; i < num_pkts; ++i) {
- bytes += ppd->tp_snaplen;
- display(ppd);
- ppd = (struct tpacket3_hdr *) ((uint8_t *) ppd +
- ppd->tp_next_offset);
- }
- packets_total += num_pkts;
- bytes_total += bytes;
- }
- static void flush_block(struct block_desc *pbd)
- {
- pbd->h1.block_status = TP_STATUS_KERNEL;
- }
- static void teardown_socket(struct ring *ring, int fd)
- {
- munmap(ring->map, ring->req.tp_block_size * ring->req.tp_block_nr);
- free(ring->rd);
- close(fd);
- }
- int main(int argc, char **argp)
- {
- int fd, err;
- socklen_t len;
- struct ring ring;
- struct pollfd pfd;
- unsigned int block_num = 0, blocks = 64;
- struct block_desc *pbd;
- struct tpacket_stats_v3 stats;
- if (argc != 2) {
- fprintf(stderr, "Usage: %s INTERFACE\n", argp[0]);
- return EXIT_FAILURE;
- }
- signal(SIGINT, sighandler);
- memset(&ring, 0, sizeof(ring));
- fd = setup_socket(&ring, argp[argc - 1]);
- assert(fd > 0);
- memset(&pfd, 0, sizeof(pfd));
- pfd.fd = fd;
- pfd.events = POLLIN | POLLERR;
- pfd.revents = 0;
- while (likely(!sigint)) {
- pbd = (struct block_desc *) ring.rd[block_num].iov_base;
- if ((pbd->h1.block_status & TP_STATUS_USER) == 0) {
- poll(&pfd, 1, -1);
- continue;
- }
- walk_block(pbd, block_num);
- flush_block(pbd);
- block_num = (block_num + 1) % blocks;
- }
- len = sizeof(stats);
- err = getsockopt(fd, SOL_PACKET, PACKET_STATISTICS, &stats, &len);
- if (err < 0) {
- perror("getsockopt");
- exit(1);
- }
- fflush(stdout);
- printf("\nReceived %u packets, %lu bytes, %u dropped, freeze_q_cnt: %u\n",
- stats.tp_packets, bytes_total, stats.tp_drops,
- stats.tp_freeze_q_cnt);
- teardown_socket(&ring, fd);
- return 0;
- }
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