src/ring.h

   1 /*
   2  * netsniff-ng - the packet sniffing beast
   3  * By Daniel Borkmann <daniel@netsniff-ng.org>
   4  * Copyright 2009, 2010 Daniel Borkmann.
   5  * Subject to the GPL, version 2.
   6  */
   7
   8 #ifndef RING_H
   9 #define RING_H
  10
  11 /*
  12  * "I love the smell of 10GbE in the morning. Smells like ... victory."
  13  *     - W. Richard Stevens, "Secret Teachings of the UNIX Environment"
  14  */
  15
  16 #include <stdio.h>
  17 #include <stdint.h>
  18 #include <linux/if_packet.h>
  19 #include <linux/socket.h>
  20 #include <linux/sockios.h>
  21 #include <sys/ioctl.h>
  22 #include <string.h>
  23 #include <poll.h>
  24 #include <sys/poll.h>
  25
  26 #include "xutils.h"
  27 #include "built_in.h"
  28 #include "mtrand.h"
  29 #include "die.h"
  30
  31 #ifndef PACKET_FANOUT
  32 # define PACKET_FANOUT                  18
  33 # define PACKET_FANOUT_POLICY_HASH      0
  34 # define PACKET_FANOUT_POLICY_LB        1
  35 # define PACKET_FANOUT_POLICY_DEFAULT   PACKET_FANOUT_HASH
  36 #endif
  37
  38 struct frame_map {
  39         struct tpacket_hdr tp_h __aligned_tpacket;
  40         struct sockaddr_ll s_ll __aligned_tpacket;
  41 };
  42
  43 struct ring {
  44         struct iovec *frames __cacheline_aligned;
  45         uint8_t *mm_space __cacheline_aligned;
  46         size_t mm_len;
  47         struct tpacket_req layout;
  48         struct sockaddr_ll s_ll;
  49 };
  50
  51 static inline void next_slot(unsigned int *it, struct ring *ring)
  52 {
  53         (*it)++;
  54         atomic_cmp_swp(it, ring->layout.tp_frame_nr, 0);
  55 }
  56
  57 static inline void next_slot_prerd(unsigned int *it, struct ring *ring)
  58 {
  59         (*it)++;
  60         atomic_cmp_swp(it, ring->layout.tp_frame_nr, 0);
  61         prefetch_rd_hi(ring->frames[*it].iov_base);
  62 }
  63
  64 static inline void next_slot_prewr(unsigned int *it, struct ring *ring)
  65 {
  66         (*it)++;
  67         atomic_cmp_swp(it, ring->layout.tp_frame_nr, 0);
  68         prefetch_wr_hi(ring->frames[*it].iov_base);
  69 }
  70
  71 static inline void next_rnd_slot(unsigned int *it, struct ring *ring)
  72 {
  73         *it = mt_rand_int32() % ring->layout.tp_frame_nr;
  74 }
  75
  76 #define RING_SIZE_FALLBACK (1 << 26)
  77
  78 static inline unsigned int ring_size(char *ifname, unsigned int size)
  79 {
  80         if (size > 0)
  81                 return size;
  82
  83         /*
  84          * Device bitrate in bytes times two as ring size.
  85          *    Fallback => ~    64,00 MB
  86          *     10 MBit => ~     2,38 MB
  87          *     54 MBit => ~    12,88 MB
  88          *    100 MBit => ~    23,84 MB
  89          *    300 MBit => ~    71,52 MB
  90          *  1.000 MBit => ~   238,42 MB
  91          * 10.000 MBit => ~ 2.384.18 MB
  92          */
  93         size = device_bitrate(ifname);
  94         size = (size * 1000000) / 8;
  95         size = size * 2;
  96         if (size == 0)
  97                 size = RING_SIZE_FALLBACK;
  98         return round_up_cacheline(size);
  99 }
 100
 101 enum ring_mode {
 102         RING_MODE_EGRESS,
 103         RING_MODE_INGRESS,
 104 };
 105
 106 static inline unsigned int ring_frame_size(struct ring *ring)
 107 {
 108         return ring->layout.tp_frame_size;
 109 }
 110
 111 static inline void tpacket_hdr_clone(struct tpacket_hdr *thdrd,
 112                                      struct tpacket_hdr *thdrs)
 113 {
 114         thdrd->tp_sec = thdrs->tp_sec;
 115         thdrd->tp_usec = thdrs->tp_usec;
 116         thdrd->tp_snaplen = thdrs->tp_snaplen;
 117         thdrd->tp_len = thdrs->tp_len;
 118 }
 119
 120 #ifndef POLLRDNORM
 121 # define POLLRDNORM     0x0040
 122 #endif
 123 #ifndef POLLWRNORM
 124 # define POLLWRNORM     0x0100
 125 #endif
 126 #ifndef POLLRDHUP
 127 # define POLLRDHUP      0x2000
 128 #endif
 129
 130 #define POLL_NEXT_PKT   0
 131 #define POLL_MOVE_OUT   1
 132
 133 static inline void prepare_polling(int sock, struct pollfd *pfd)
 134 {
 135         memset(pfd, 0, sizeof(*pfd));
 136         pfd->fd = sock;
 137         pfd->revents = 0;
 138         pfd->events = POLLIN | POLLRDNORM | POLLERR;
 139 }
 140
 141 static inline void set_sockopt_fanout(int sock, unsigned int fanout_id,
 142                                       unsigned int fanout_type)
 143 {
 144         unsigned int fanout_arg = (fanout_id | (fanout_type << 16));
 145         int ret = setsockopt(sock, SOL_PACKET, PACKET_FANOUT, &fanout_arg,
 146                              sizeof(fanout_arg));
 147         if (ret)
 148                 panic("No packet fanout support!\n");
 149 }
 150
 151 #if defined(__WITH_HARDWARE_TIMESTAMPING)
 152 # include <linux/net_tstamp.h>
 153
 154 static inline void set_sockopt_hwtimestamp(int sock, const char *dev)
 155 {
 156         int timesource, ret;
 157         struct hwtstamp_config hwconfig;
 158         struct ifreq ifr;
 159
 160         memset(&hwconfig, 0, sizeof(hwconfig));
 161         hwconfig.tx_type = HWTSTAMP_TX_ON;
 162         hwconfig.rx_filter = HWTSTAMP_FILTER_ALL;
 163
 164         memset(&ifr, 0, sizeof(ifr));
 165         strlcpy(ifr.ifr_name, dev, sizeof(ifr.ifr_name));
 166         ifr.ifr_data = &hwconfig;
 167
 168         ret = ioctl(sock, SIOCSHWTSTAMP, &ifr);
 169         if (ret < 0)
 170                 return;
 171
 172         timesource = SOF_TIMESTAMPING_RAW_HARDWARE;
 173
 174         ret = setsockopt(sock, SOL_PACKET, PACKET_TIMESTAMP, &timesource,
 175                          sizeof(timesource));
 176         if (ret)
 177                 panic("Cannot set timestamping!\n");
 178 }
 179 #else
 180 static inline void set_sockopt_hwtimestamp(int sock, const char *dev)
 181 {
 182         return;
 183 }
 184 #endif /* defined(__WITH_HARDWARE_TIMESTAMPING) */
 185 #endif /* RING_H */