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 "die.h"
  29
  30 #ifndef PACKET_FANOUT
  31 # define PACKET_FANOUT                  18
  32 # define PACKET_FANOUT_POLICY_HASH      0
  33 # define PACKET_FANOUT_POLICY_LB        1
  34 # define PACKET_FANOUT_POLICY_DEFAULT   PACKET_FANOUT_HASH
  35 #endif
  36
  37 struct frame_map {
  38         struct tpacket2_hdr tp_h __aligned_tpacket;
  39         struct sockaddr_ll s_ll __align_tpacket(sizeof(struct tpacket2_hdr));
  40 };
  41
  42 struct ring {
  43         struct iovec *frames;
  44         uint8_t *mm_space;
  45         size_t mm_len;
  46         struct tpacket_req layout;
  47         struct sockaddr_ll s_ll;
  48 };
  49
  50 static inline void next_rnd_slot(unsigned int *it, struct ring *ring)
  51 {
  52         *it = rand() % ring->layout.tp_frame_nr;
  53 }
  54
  55 #define RING_SIZE_FALLBACK (1 << 26)
  56
  57 static inline unsigned int ring_size(char *ifname, unsigned int size)
  58 {
  59         if (size > 0)
  60                 return size;
  61
  62         /*
  63          * Device bitrate in bytes times two as ring size.
  64          *    Fallback => ~    64,00 MB
  65          *     10 MBit => ~     2,38 MB
  66          *     54 MBit => ~    12,88 MB
  67          *    100 MBit => ~    23,84 MB
  68          *    300 MBit => ~    71,52 MB
  69          *  1.000 MBit => ~   238,42 MB
  70          * 10.000 MBit => ~ 2.384.18 MB
  71          */
  72         size = device_bitrate(ifname);
  73         size = (size * 1000000) / 8;
  74         size = size * 2;
  75         if (size == 0)
  76                 size = RING_SIZE_FALLBACK;
  77
  78         return round_up_cacheline(size);
  79 }
  80
  81 static inline unsigned int ring_frame_size(struct ring *ring)
  82 {
  83         return ring->layout.tp_frame_size;
  84 }
  85
  86 static inline void tpacket_hdr_clone(struct tpacket2_hdr *thdrd,
  87                                      struct tpacket2_hdr *thdrs)
  88 {
  89         thdrd->tp_sec = thdrs->tp_sec;
  90         thdrd->tp_nsec = thdrs->tp_nsec;
  91         thdrd->tp_snaplen = thdrs->tp_snaplen;
  92         thdrd->tp_len = thdrs->tp_len;
  93 }
  94
  95 #ifndef POLLRDNORM
  96 # define POLLRDNORM     0x0040
  97 #endif
  98 #ifndef POLLWRNORM
  99 # define POLLWRNORM     0x0100
 100 #endif
 101 #ifndef POLLRDHUP
 102 # define POLLRDHUP      0x2000
 103 #endif
 104
 105 #define POLL_NEXT_PKT   0
 106 #define POLL_MOVE_OUT   1
 107
 108 static inline void prepare_polling(int sock, struct pollfd *pfd)
 109 {
 110         memset(pfd, 0, sizeof(*pfd));
 111         pfd->fd = sock;
 112         pfd->revents = 0;
 113         pfd->events = POLLIN | POLLRDNORM | POLLERR;
 114 }
 115
 116 static inline void set_sockopt_fanout(int sock, unsigned int fanout_id,
 117                                       unsigned int fanout_type)
 118 {
 119         unsigned int fanout_arg = (fanout_id | (fanout_type << 16));
 120         int ret = setsockopt(sock, SOL_PACKET, PACKET_FANOUT, &fanout_arg,
 121                              sizeof(fanout_arg));
 122         if (ret)
 123                 panic("No packet fanout support!\n");
 124 }
 125
 126 static inline void set_sockopt_tpacket(int sock)
 127 {
 128         int ret, val = TPACKET_V2;
 129
 130         ret = setsockopt(sock, SOL_PACKET, PACKET_VERSION, &val, sizeof(val));
 131         if (ret)
 132                 panic("Cannot set tpacketv2!\n");
 133 }
 134
 135 #ifdef __WITH_HARDWARE_TIMESTAMPING
 136 # include <linux/net_tstamp.h>
 137
 138 static inline void set_sockopt_hwtimestamp(int sock, const char *dev)
 139 {
 140         int timesource, ret;
 141         struct hwtstamp_config hwconfig;
 142         struct ifreq ifr;
 143
 144         if (!strncmp("any", dev, strlen("any")))
 145                 return;
 146
 147         memset(&hwconfig, 0, sizeof(hwconfig));
 148         hwconfig.tx_type = HWTSTAMP_TX_ON;
 149         hwconfig.rx_filter = HWTSTAMP_FILTER_ALL;
 150
 151         memset(&ifr, 0, sizeof(ifr));
 152         strlcpy(ifr.ifr_name, dev, sizeof(ifr.ifr_name));
 153         ifr.ifr_data = &hwconfig;
 154
 155         ret = ioctl(sock, SIOCSHWTSTAMP, &ifr);
 156         if (ret < 0) {
 157                 if (errno == EOPNOTSUPP)
 158                         return;
 159                 panic("Cannot set timestamping: %s\n", strerror(errno));
 160         }
 161
 162         timesource = SOF_TIMESTAMPING_RAW_HARDWARE;
 163
 164         ret = setsockopt(sock, SOL_PACKET, PACKET_TIMESTAMP, &timesource,
 165                          sizeof(timesource));
 166         if (ret)
 167                 panic("Cannot set timestamping: %s!\n", strerror(errno));
 168 }
 169 #else
 170 static inline void set_sockopt_hwtimestamp(int sock, const char *dev)
 171 {
 172         return;
 173 }
 174 #endif
 175 #endif /* RING_H */