ring_rx.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 <inttypes.h>
   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_rx.h"
  21 #include "built_in.h"
  22
  23 void destroy_rx_ring(int sock, struct ring *ring)
  24 {
  25         int ret;
  26         bool v3 = get_sockopt_tpacket(sock) == TPACKET_V3;
  27
  28         munmap(ring->mm_space, ring->mm_len);
  29         ring->mm_len = 0;
  30
  31         xfree(ring->frames);
  32
  33         /* In general, this is freed during close(2) anyway. */
  34         if (v3)
  35                 return;
  36
  37         fmemset(&ring->layout, 0, sizeof(ring->layout));
  38         ret = setsockopt(sock, SOL_PACKET, PACKET_RX_RING, &ring->layout,
  39                          sizeof(ring->layout));
  40         if (unlikely(ret))
  41                 panic("Cannot destroy the RX_RING: %s!\n", strerror(errno));
  42 }
  43
  44 static void setup_rx_ring_layout(int sock, struct ring *ring, size_t size,
  45                                  bool jumbo_support, bool v3)
  46 {
  47         fmemset(&ring->layout, 0, sizeof(ring->layout));
  48
  49         ring->layout.tp_block_size = (jumbo_support ?
  50                                       RUNTIME_PAGE_SIZE << 4 :
  51                                       RUNTIME_PAGE_SIZE << 2);
  52
  53         ring->layout.tp_frame_size = (jumbo_support ?
  54                                       TPACKET_ALIGNMENT << 12 :
  55                                       TPACKET_ALIGNMENT << 7);
  56
  57         ring->layout.tp_block_nr = size / ring->layout.tp_block_size;
  58         ring->layout.tp_frame_nr = ring->layout.tp_block_size /
  59                                    ring->layout.tp_frame_size *
  60                                    ring->layout.tp_block_nr;
  61         if (v3) {
  62                 /* Pass out, if this will ever change and we do crap on it! */
  63                 build_bug_on(offsetof(struct tpacket_req, tp_frame_nr) !=
  64                              offsetof(struct tpacket_req3, tp_frame_nr) &&
  65                              sizeof(struct tpacket_req) !=
  66                              offsetof(struct tpacket_req3, tp_retire_blk_tov));
  67
  68                 ring->layout3.tp_retire_blk_tov = 100; /* 0: let kernel decide */
  69                 ring->layout3.tp_sizeof_priv = 0;
  70                 ring->layout3.tp_feature_req_word = 0;
  71
  72                 set_sockopt_tpacket_v3(sock);
  73         } else {
  74                 set_sockopt_tpacket_v2(sock);
  75         }
  76
  77         ring_verify_layout(ring);
  78 }
  79
  80 static void create_rx_ring(int sock, struct ring *ring, bool verbose)
  81 {
  82         int ret;
  83         bool v3 = get_sockopt_tpacket(sock) == TPACKET_V3;
  84
  85 retry:
  86         ret = setsockopt(sock, SOL_PACKET, PACKET_RX_RING, &ring->raw,
  87                          v3 ? sizeof(ring->layout3) : sizeof(ring->layout));
  88
  89         if (errno == ENOMEM && ring->layout.tp_block_nr > 1) {
  90                 ring->layout.tp_block_nr >>= 1;
  91                 ring->layout.tp_frame_nr = ring->layout.tp_block_size /
  92                                            ring->layout.tp_frame_size *
  93                                            ring->layout.tp_block_nr;
  94                 goto retry;
  95         }
  96         if (ret < 0)
  97                 panic("Cannot allocate RX_RING!\n");
  98
  99         ring->mm_len = (size_t) ring->layout.tp_block_size * ring->layout.tp_block_nr;
 100
 101         if (verbose) {
 102                 if (!v3) {
 103                         printf("RX,V2: %.2Lf MiB, %u Frames, each %u Byte allocated\n",
 104                                (long double) ring->mm_len / (1 << 20),
 105                                ring->layout.tp_frame_nr, ring->layout.tp_frame_size);
 106                 } else {
 107                         printf("RX,V3: %.2Lf MiB, %u Blocks, each %u Byte allocated\n",
 108                                (long double) ring->mm_len / (1 << 20),
 109                                ring->layout.tp_block_nr, ring->layout.tp_block_size);
 110                 }
 111         }
 112 }
 113
 114 static void alloc_rx_ring_frames(int sock, struct ring *ring)
 115 {
 116         int num;
 117         size_t size;
 118         bool v3 = get_sockopt_tpacket(sock) == TPACKET_V3;
 119
 120         if (v3) {
 121                 num = ring->layout3.tp_block_nr;
 122                 size = ring->layout3.tp_block_size;
 123         } else {
 124                 num = ring->layout.tp_frame_nr;
 125                 size = ring->layout.tp_frame_size;
 126         }
 127
 128         alloc_ring_frames_generic(ring, num, size);
 129 }
 130
 131 void ring_rx_setup(struct ring *ring, int sock, size_t size, int ifindex,
 132                    struct pollfd *poll, bool v3, bool jumbo_support,
 133                    bool verbose)
 134 {
 135         fmemset(ring, 0, sizeof(*ring));
 136         setup_rx_ring_layout(sock, ring, size, jumbo_support, v3);
 137         create_rx_ring(sock, ring, verbose);
 138         mmap_ring_generic(sock, ring);
 139         alloc_rx_ring_frames(sock, ring);
 140         bind_ring_generic(sock, ring, ifindex, false);
 141         prepare_polling(sock, poll);
 142 }
 143
 144 void sock_rx_net_stats(int sock, unsigned long seen)
 145 {
 146         int ret;
 147         bool v3 = get_sockopt_tpacket(sock) == TPACKET_V3;
 148         union {
 149                 struct tpacket_stats    k2;
 150                 struct tpacket_stats_v3 k3;
 151         } stats;
 152         socklen_t slen = v3 ? sizeof(stats.k3) : sizeof(stats.k2);
 153
 154         memset(&stats, 0, sizeof(stats));
 155         ret = getsockopt(sock, SOL_PACKET, PACKET_STATISTICS, &stats, &slen);
 156         if (ret > -1) {
 157                 uint64_t packets = stats.k3.tp_packets;
 158                 uint64_t drops = stats.k3.tp_drops;
 159
 160                 printf("\r%12"PRIu64"  packets incoming (%"PRIu64" unread on exit)\n",
 161                        v3 ? (uint64_t)seen : packets, v3 ? packets - seen : 0);
 162                 printf("\r%12"PRIu64"  packets passed filter\n", packets - drops);
 163                 printf("\r%12"PRIu64"  packets failed filter (out of space)\n", drops);
 164                 if (stats.k3.tp_packets > 0)
 165                         printf("\r%12.4lf%% packet droprate\n",
 166                                (1.0 * drops / packets) * 100.0);
 167         }
 168 }