ring_rx.c

   1 /*
   2  * netsniff-ng - the packet sniffing beast
   3  * Copyright 2009, 2010 Daniel Borkmann.
   4  * Copyright 2014 Tobias Klauser.
   5  * Subject to the GPL, version 2.
   6  */
   7
   8 #include <inttypes.h>
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <string.h>
  12 #include <unistd.h>
  13 #include <sys/mman.h>
  14 #include <sys/types.h>
  15 #include <sys/socket.h>
  16 #include <arpa/inet.h>
  17 #include <linux/if_ether.h>
  18
  19 #include "xmalloc.h"
  20 #include "die.h"
  21 #include "ring_rx.h"
  22 #include "built_in.h"
  23
  24 /*
  25  * tpacket v3 data structures and constants are not available for older kernel
  26  * versions which only support tpacket v2, thus we need protect access to them.
  27  */
  28 #ifdef HAVE_TPACKET3
  29 static inline bool is_tpacket_v3(int sock)
  30 {
  31         return get_sockopt_tpacket(sock) == TPACKET_V3;
  32 }
  33
  34 static inline size_t get_ring_layout_size(struct ring *ring, bool v3)
  35 {
  36         return v3 ? sizeof(ring->layout3) : sizeof(ring->layout);
  37 }
  38
  39 static inline void setup_rx_ring_layout_v3(struct ring *ring)
  40 {
  41         /* Pass out, if this will ever change and we do crap on it! */
  42         build_bug_on(offsetof(struct tpacket_req, tp_frame_nr) !=
  43                      offsetof(struct tpacket_req3, tp_frame_nr) &&
  44                      sizeof(struct tpacket_req) !=
  45                      offsetof(struct tpacket_req3, tp_retire_blk_tov));
  46
  47         ring->layout3.tp_retire_blk_tov = 100; /* 0: let kernel decide */
  48         ring->layout3.tp_sizeof_priv = 0;
  49         ring->layout3.tp_feature_req_word = 0;
  50 }
  51
  52 static inline int rx_ring_get_num(struct ring *ring, bool v3)
  53 {
  54         return v3 ? ring->layout3.tp_block_nr : ring->layout.tp_frame_nr;
  55 }
  56
  57 static inline size_t rx_ring_get_size(struct ring *ring, bool v3)
  58 {
  59         return v3 ? ring->layout3.tp_block_size : ring->layout.tp_frame_size;
  60 }
  61
  62 int get_rx_net_stats(int sock, uint64_t *packets, uint64_t *drops, bool v3)
  63 {
  64         int ret;
  65         union {
  66                 struct tpacket_stats    k2;
  67                 struct tpacket_stats_v3 k3;
  68         } stats;
  69         socklen_t slen = v3 ? sizeof(stats.k3) : sizeof(stats.k2);
  70
  71         memset(&stats, 0, sizeof(stats));
  72         ret = getsockopt(sock, SOL_PACKET, PACKET_STATISTICS, &stats, &slen);
  73         if (ret == 0) {
  74                 *packets = stats.k3.tp_packets;
  75                 *drops = stats.k3.tp_drops;
  76         }
  77         return ret;
  78 }
  79 #else
  80 static inline bool is_tpacket_v3(int sock __maybe_unused)
  81 {
  82         return false;
  83 }
  84
  85 static inline size_t get_ring_layout_size(struct ring *ring, bool v3 __maybe_unused)
  86 {
  87         return sizeof(ring->layout);
  88 }
  89
  90 static inline void setup_rx_ring_layout_v3(struct ring *ring __maybe_unused)
  91 {
  92 }
  93
  94 static inline int rx_ring_get_num(struct ring *ring, bool v3 __maybe_unused)
  95 {
  96         return ring->layout.tp_frame_nr;
  97 }
  98
  99 static inline size_t rx_ring_get_size(struct ring *ring, bool v3 __maybe_unused)
 100 {
 101         return ring->layout.tp_frame_size;
 102 }
 103
 104 int get_rx_net_stats(int sock, uint64_t *packets, uint64_t *drops,
 105                      bool v3 __maybe_unused)
 106 {
 107         int ret;
 108         struct tpacket_stats stats;
 109         socklen_t slen = sizeof(stats);
 110
 111         memset(&stats, 0, sizeof(stats));
 112         ret = getsockopt(sock, SOL_PACKET, PACKET_STATISTICS, &stats, &slen);
 113         if (ret == 0) {
 114                 *packets = stats.tp_packets;
 115                 *drops = stats.tp_drops;
 116         }
 117         return ret;
 118 }
 119 #endif /* HAVE_TPACKET3 */
 120
 121 void destroy_rx_ring(int sock, struct ring *ring)
 122 {
 123         int ret;
 124         bool v3 = is_tpacket_v3(sock);
 125
 126         munmap(ring->mm_space, ring->mm_len);
 127         ring->mm_len = 0;
 128
 129         xfree(ring->frames);
 130
 131         /* In general, this is freed during close(2) anyway. */
 132         if (v3)
 133                 return;
 134
 135         fmemset(&ring->layout, 0, sizeof(ring->layout));
 136         ret = setsockopt(sock, SOL_PACKET, PACKET_RX_RING, &ring->layout,
 137                          sizeof(ring->layout));
 138         if (unlikely(ret))
 139                 panic("Cannot destroy the RX_RING: %s!\n", strerror(errno));
 140 }
 141
 142 static void setup_rx_ring_layout(int sock, struct ring *ring, size_t size,
 143                                  bool jumbo_support, bool v3)
 144 {
 145         fmemset(&ring->layout, 0, sizeof(ring->layout));
 146
 147         ring->layout.tp_block_size = (jumbo_support ?
 148                                       RUNTIME_PAGE_SIZE << 4 :
 149                                       RUNTIME_PAGE_SIZE << 2);
 150
 151         ring->layout.tp_frame_size = (jumbo_support ?
 152                                       TPACKET_ALIGNMENT << 12 :
 153                                       TPACKET_ALIGNMENT << 7);
 154
 155         ring->layout.tp_block_nr = size / ring->layout.tp_block_size;
 156         ring->layout.tp_frame_nr = ring->layout.tp_block_size /
 157                                    ring->layout.tp_frame_size *
 158                                    ring->layout.tp_block_nr;
 159
 160         if (v3) {
 161                 setup_rx_ring_layout_v3(ring);
 162                 set_sockopt_tpacket_v3(sock);
 163         } else {
 164                 set_sockopt_tpacket_v2(sock);
 165         }
 166
 167         ring_verify_layout(ring);
 168 }
 169
 170 static void create_rx_ring(int sock, struct ring *ring, bool verbose)
 171 {
 172         int ret;
 173         bool v3 = is_tpacket_v3(sock);
 174         size_t layout_size = get_ring_layout_size(ring, v3);
 175
 176 retry:
 177         ret = setsockopt(sock, SOL_PACKET, PACKET_RX_RING, &ring->raw,
 178                          layout_size);
 179
 180         if (errno == ENOMEM && ring->layout.tp_block_nr > 1) {
 181                 ring->layout.tp_block_nr >>= 1;
 182                 ring->layout.tp_frame_nr = ring->layout.tp_block_size /
 183                                            ring->layout.tp_frame_size *
 184                                            ring->layout.tp_block_nr;
 185                 goto retry;
 186         }
 187         if (ret < 0)
 188                 panic("Cannot allocate RX_RING!\n");
 189
 190         ring->mm_len = (size_t) ring->layout.tp_block_size * ring->layout.tp_block_nr;
 191
 192         if (verbose) {
 193                 if (!v3) {
 194                         printf("RX,V2: %.2Lf MiB, %u Frames, each %u Byte allocated\n",
 195                                (long double) ring->mm_len / (1 << 20),
 196                                ring->layout.tp_frame_nr, ring->layout.tp_frame_size);
 197                 } else {
 198                         printf("RX,V3: %.2Lf MiB, %u Blocks, each %u Byte allocated\n",
 199                                (long double) ring->mm_len / (1 << 20),
 200                                ring->layout.tp_block_nr, ring->layout.tp_block_size);
 201                 }
 202         }
 203 }
 204
 205 static void alloc_rx_ring_frames(int sock, struct ring *ring)
 206 {
 207         bool v3 = is_tpacket_v3(sock);
 208
 209         alloc_ring_frames_generic(ring, rx_ring_get_num(ring, v3),
 210                                   rx_ring_get_size(ring, v3));
 211 }
 212
 213 void join_fanout_group(int sock, uint32_t fanout_group, uint32_t fanout_type)
 214 {
 215         uint32_t fanout_opt = 0;
 216         int ret;
 217
 218         if (fanout_group == 0)
 219                 return;
 220
 221         fanout_opt = (fanout_group & 0xffff) | (fanout_type << 16);
 222
 223         ret = setsockopt(sock, SOL_PACKET, PACKET_FANOUT, &fanout_opt,
 224                          sizeof(fanout_opt));
 225         if (ret < 0)
 226                 panic("Cannot set fanout ring mode!\n");
 227 }
 228
 229 void ring_rx_setup(struct ring *ring, int sock, size_t size, int ifindex,
 230                    struct pollfd *poll, bool v3, bool jumbo_support,
 231                    bool verbose, uint32_t fanout_group, uint32_t fanout_type)
 232 {
 233         fmemset(ring, 0, sizeof(*ring));
 234         setup_rx_ring_layout(sock, ring, size, jumbo_support, v3);
 235         create_rx_ring(sock, ring, verbose);
 236         mmap_ring_generic(sock, ring);
 237         alloc_rx_ring_frames(sock, ring);
 238         bind_ring_generic(sock, ring, ifindex, false);
 239         join_fanout_group(sock, fanout_group, fanout_type);
 240         prepare_polling(sock, poll);
 241 }