ring.c

   1 /*
   2  * netsniff-ng - the packet sniffing beast
   3  * Copyright 2009, 2010 Daniel Borkmann.
   4  * Copyright 2014, 2015 Tobias Klauser
   5  * Subject to the GPL, version 2.
   6  */
   7
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <string.h>
  11 #include <unistd.h>
  12 #include <sys/mman.h>
  13 #include <sys/types.h>
  14 #include <sys/socket.h>
  15 #include <arpa/inet.h>
  16 #include <linux/if_ether.h>
  17
  18 #include "xmalloc.h"
  19 #include "die.h"
  20 #include "ring.h"
  21 #include "built_in.h"
  22
  23 void setup_ring_layout_generic(struct ring *ring, size_t size,
  24                                bool jumbo_support)
  25 {
  26         fmemset(&ring->layout, 0, sizeof(ring->layout));
  27
  28         ring->layout.tp_block_size = (jumbo_support ?
  29                                       RUNTIME_PAGE_SIZE << 4 :
  30                                       RUNTIME_PAGE_SIZE << 2);
  31
  32         ring->layout.tp_frame_size = (jumbo_support ?
  33                                       TPACKET_ALIGNMENT << 12 :
  34                                       TPACKET_ALIGNMENT << 7);
  35
  36         ring->layout.tp_block_nr = size / ring->layout.tp_block_size;
  37         ring->layout.tp_frame_nr = size / ring->layout.tp_frame_size;
  38 }
  39
  40 void mmap_ring_generic(int sock, struct ring *ring)
  41 {
  42         ring->mm_space = mmap(NULL, ring->mm_len, PROT_READ | PROT_WRITE,
  43                               MAP_SHARED | MAP_LOCKED | MAP_POPULATE, sock, 0);
  44         if (ring->mm_space == MAP_FAILED)
  45                 panic("Cannot mmap {TX,RX}_RING!\n");
  46 }
  47
  48 void alloc_ring_frames_generic(struct ring *ring, size_t num, size_t size)
  49 {
  50         size_t i, len = num * sizeof(*ring->frames);
  51
  52         ring->frames = xzmalloc_aligned(len, CO_CACHE_LINE_SIZE);
  53
  54         for (i = 0; i < num; ++i) {
  55                 ring->frames[i].iov_len = size;
  56                 ring->frames[i].iov_base = ring->mm_space + (i * size);
  57         }
  58 }
  59
  60 void bind_ring_generic(int sock, struct ring *ring, int ifindex, bool tx_only)
  61 {
  62         int ret;
  63
  64         /* The {TX,RX}_RING registers itself to the networking stack with
  65          * dev_add_pack(), so we have one single RX_RING for all devs
  66          * otherwise you'll get the packet twice.
  67          */
  68         fmemset(&ring->s_ll, 0, sizeof(ring->s_ll));
  69
  70         ring->s_ll.sll_family = AF_PACKET;
  71         ring->s_ll.sll_ifindex = ifindex;
  72         ring->s_ll.sll_protocol = tx_only ? 0 : htons(ETH_P_ALL);
  73
  74         ret = bind(sock, (struct sockaddr *) &ring->s_ll, sizeof(ring->s_ll));
  75         if (ret < 0)
  76                 panic("Cannot bind {TX,RX}_RING!\n");
  77 }