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