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 tpacket2_hdr tp_h __aligned_tpacket;
  40         struct sockaddr_ll s_ll __align_tpacket(sizeof(struct tpacket2_hdr));
  41 };
  42
  43 struct ring {
  44         struct iovec *frames __cacheline_aligned;
  45         uint8_t *mm_space;
  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_rnd_slot(unsigned int *it, struct ring *ring)
  58 {
  59         *it = mt_rand_int32() % ring->layout.tp_frame_nr;
  60 }
  61
  62 #define RING_SIZE_FALLBACK (1 << 26)
  63
  64 static inline unsigned int ring_size(char *ifname, unsigned int size)
  65 {
  66         if (size > 0)
  67                 return size;
  68
  69         /*
  70          * Device bitrate in bytes times two as ring size.
  71          *    Fallback => ~    64,00 MB
  72          *     10 MBit => ~     2,38 MB
  73          *     54 MBit => ~    12,88 MB
  74          *    100 MBit => ~    23,84 MB
  75          *    300 MBit => ~    71,52 MB
  76          *  1.000 MBit => ~   238,42 MB
  77          * 10.000 MBit => ~ 2.384.18 MB
  78          */
  79         size = device_bitrate(ifname);
  80         size = (size * 1000000) / 8;
  81         size = size * 2;
  82         if (size == 0)
  83                 size = RING_SIZE_FALLBACK;
  84
  85         return round_up_cacheline(size);
  86 }
  87
  88 enum ring_mode {
  89         RING_MODE_EGRESS,
  90         RING_MODE_INGRESS,
  91 };
  92
  93 static inline unsigned int ring_frame_size(struct ring *ring)
  94 {
  95         return ring->layout.tp_frame_size;
  96 }
  97
  98 static inline void tpacket_hdr_clone(struct tpacket2_hdr *thdrd,
  99                                      struct tpacket2_hdr *thdrs)
 100 {
 101         thdrd->tp_sec = thdrs->tp_sec;
 102         thdrd->tp_nsec = thdrs->tp_nsec;
 103         thdrd->tp_snaplen = thdrs->tp_snaplen;
 104         thdrd->tp_len = thdrs->tp_len;
 105 }
 106
 107 #ifndef POLLRDNORM
 108 # define POLLRDNORM     0x0040
 109 #endif
 110 #ifndef POLLWRNORM
 111 # define POLLWRNORM     0x0100
 112 #endif
 113 #ifndef POLLRDHUP
 114 # define POLLRDHUP      0x2000
 115 #endif
 116
 117 #define POLL_NEXT_PKT   0
 118 #define POLL_MOVE_OUT   1
 119
 120 static inline void prepare_polling(int sock, struct pollfd *pfd)
 121 {
 122         memset(pfd, 0, sizeof(*pfd));
 123         pfd->fd = sock;
 124         pfd->revents = 0;
 125         pfd->events = POLLIN | POLLRDNORM | POLLERR;
 126 }
 127
 128 static inline void set_sockopt_fanout(int sock, unsigned int fanout_id,
 129                                       unsigned int fanout_type)
 130 {
 131         unsigned int fanout_arg = (fanout_id | (fanout_type << 16));
 132         int ret = setsockopt(sock, SOL_PACKET, PACKET_FANOUT, &fanout_arg,
 133                              sizeof(fanout_arg));
 134         if (ret)
 135                 panic("No packet fanout support!\n");
 136 }
 137
 138 static inline void set_sockopt_tpacket(int sock)
 139 {
 140         int ret, val = TPACKET_V2;
 141
 142         ret = setsockopt(sock, SOL_PACKET, PACKET_VERSION, &val, sizeof(val));
 143         if (ret)
 144                 panic("Cannot set tpacketv2!\n");
 145 }
 146
 147 #if defined(__WITH_HARDWARE_TIMESTAMPING)
 148 # include <linux/net_tstamp.h>
 149
 150 static inline void set_sockopt_hwtimestamp(int sock, const char *dev)
 151 {
 152         int timesource, ret;
 153         struct hwtstamp_config hwconfig;
 154         struct ifreq ifr;
 155
 156         memset(&hwconfig, 0, sizeof(hwconfig));
 157         hwconfig.tx_type = HWTSTAMP_TX_ON;
 158         hwconfig.rx_filter = HWTSTAMP_FILTER_ALL;
 159
 160         memset(&ifr, 0, sizeof(ifr));
 161         strlcpy(ifr.ifr_name, dev, sizeof(ifr.ifr_name));
 162         ifr.ifr_data = &hwconfig;
 163
 164         ret = ioctl(sock, SIOCSHWTSTAMP, &ifr);
 165         if (ret < 0)
 166                 return;
 167
 168         timesource = SOF_TIMESTAMPING_RAW_HARDWARE;
 169
 170         ret = setsockopt(sock, SOL_PACKET, PACKET_TIMESTAMP, &timesource,
 171                          sizeof(timesource));
 172         if (ret)
 173                 panic("Cannot set timestamping!\n");
 174 }
 175 #else
 176 static inline void set_sockopt_hwtimestamp(int sock, const char *dev)
 177 {
 178         return;
 179 }
 180 #endif /* defined(__WITH_HARDWARE_TIMESTAMPING) */
 181 #endif /* RING_H */