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