ring.c

   1 /*
   2  * netsniff-ng - the packet sniffing beast
   3  * Copyright 2009, 2010 Daniel Borkmann.
   4  * Subject to the GPL, version 2.
   5  */
   6
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <string.h>
  10 #include <unistd.h>
  11 #include <sys/mman.h>
  12 #include <sys/types.h>
  13 #include <sys/socket.h>
  14 #include <arpa/inet.h>
  15 #include <linux/if_ether.h>
  16
  17 #include "xmalloc.h"
  18 #include "die.h"
  19 #include "ring.h"
  20 #include "built_in.h"
  21
  22 void mmap_ring_generic(int sock, struct ring *ring)
  23 {
  24         ring->mm_space = mmap(NULL, ring->mm_len, PROT_READ | PROT_WRITE,
  25                               MAP_SHARED | MAP_LOCKED | MAP_POPULATE, sock, 0);
  26         if (ring->mm_space == MAP_FAILED)
  27                 panic("Cannot mmap {TX,RX}_RING!\n");
  28 }
  29
  30 void alloc_ring_frames_generic(struct ring *ring, int num, size_t size)
  31 {
  32         int i;
  33         size_t len = num * sizeof(*ring->frames);
  34
  35         ring->frames = xmalloc_aligned(len, CO_CACHE_LINE_SIZE);
  36         fmemset(ring->frames, 0, len);
  37
  38         for (i = 0; i < num; ++i) {
  39                 ring->frames[i].iov_len = size;
  40                 ring->frames[i].iov_base = ring->mm_space + (i * size);
  41         }
  42 }
  43
  44 void bind_ring_generic(int sock, struct ring *ring, int ifindex, bool tx_only)
  45 {
  46         int ret;
  47         /* The {TX,RX}_RING registers itself to the networking stack with
  48          * dev_add_pack(), so we have one single RX_RING for all devs
  49          * otherwise you'll get the packet twice.
  50          */
  51         fmemset(&ring->s_ll, 0, sizeof(ring->s_ll));
  52
  53         ring->s_ll.sll_family = AF_PACKET;
  54         if (tx_only)
  55                 ring->s_ll.sll_protocol = 0;
  56         else
  57                 ring->s_ll.sll_protocol = htons(ETH_P_ALL);
  58         ring->s_ll.sll_ifindex = ifindex;
  59         ring->s_ll.sll_hatype = 0;
  60         ring->s_ll.sll_halen = 0;
  61         ring->s_ll.sll_pkttype = 0;
  62
  63         ret = bind(sock, (struct sockaddr *) &ring->s_ll, sizeof(ring->s_ll));
  64         if (ret < 0)
  65                 panic("Cannot bind {TX,RX}_RING!\n");
  66 }