ring.h

   1 /*
   2  * netsniff-ng - the packet sniffing beast
   3  * Copyright 2009, 2010 Daniel Borkmann.
   4  * Subject to the GPL, version 2.
   5  */
   6
   7 #ifndef RING_H
   8 #define RING_H
   9
  10 /*
  11  * "I love the smell of 10GbE in the morning. Smells like ... victory."
  12  *     - W. Richard Stevens, "Secret Teachings of the UNIX Environment"
  13  */
  14
  15 #include <stdio.h>
  16 #include <stdint.h>
  17 #include <linux/if_packet.h>
  18 #include <linux/socket.h>
  19 #include <linux/sockios.h>
  20 #include <sys/ioctl.h>
  21 #include <string.h>
  22 #include <poll.h>
  23
  24 #include "built_in.h"
  25 #include "die.h"
  26 #include "dev.h"
  27 #include "config.h"
  28
  29 union tpacket_uhdr {
  30         struct tpacket_hdr  *h1;
  31         struct tpacket2_hdr *h2;
  32 #ifdef HAVE_TPACKET3
  33         struct tpacket3_hdr *h3;
  34 #endif
  35         void *raw;
  36 };
  37
  38 #ifdef HAVE_TPACKET3
  39 #define tpacket_uhdr(hdr, member, v3)   \
  40         ((v3) ? ((hdr).h3)->member : ((hdr).h2)->member)
  41 #else
  42 #define tpacket_uhdr(hdr, member, v3)   \
  43         (((hdr).h2)->member)
  44 #endif /* HAVE_TPACKET3 */
  45
  46 struct frame_map {
  47         struct tpacket2_hdr tp_h __aligned_tpacket;
  48         struct sockaddr_ll s_ll __align_tpacket(sizeof(struct tpacket2_hdr));
  49 };
  50
  51 #ifdef HAVE_TPACKET3
  52 struct block_desc {
  53         uint32_t version;
  54         uint32_t offset_to_priv;
  55         struct tpacket_hdr_v1 h1;
  56 };
  57 #endif
  58
  59 struct ring {
  60         struct iovec *frames;
  61         uint8_t *mm_space;
  62         size_t mm_len;
  63         struct sockaddr_ll s_ll;
  64         union {
  65                 struct tpacket_req layout;
  66 #ifdef HAVE_TPACKET3
  67                 struct tpacket_req3 layout3;
  68 #endif
  69                 uint8_t raw;
  70         };
  71 };
  72
  73 static inline void next_rnd_slot(unsigned int *it, struct ring *ring)
  74 {
  75         *it = rand() % ring->layout.tp_frame_nr;
  76 }
  77
  78 static inline size_t ring_size(char *ifname, size_t 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 = 1 << 26;
  98
  99         return round_up_cacheline(size);
 100 }
 101
 102 static inline unsigned int ring_frame_size(struct ring *ring)
 103 {
 104         return ring->layout.tp_frame_size;
 105 }
 106
 107 static inline void ring_verify_layout(struct ring *ring)
 108 {
 109         bug_on(ring->layout.tp_block_size  < ring->layout.tp_frame_size);
 110         bug_on((ring->layout.tp_block_size % ring->layout.tp_frame_size) != 0);
 111         bug_on((ring->layout.tp_block_size % RUNTIME_PAGE_SIZE) != 0);
 112 }
 113
 114 static inline void tpacket_hdr_clone(struct tpacket2_hdr *thdrd,
 115                                      struct tpacket2_hdr *thdrs)
 116 {
 117         thdrd->tp_sec = thdrs->tp_sec;
 118         thdrd->tp_nsec = thdrs->tp_nsec;
 119         thdrd->tp_snaplen = thdrs->tp_snaplen;
 120         thdrd->tp_len = thdrs->tp_len;
 121 }
 122
 123 static inline void prepare_polling(int sock, struct pollfd *pfd)
 124 {
 125         memset(pfd, 0, sizeof(*pfd));
 126         pfd->fd = sock;
 127         pfd->revents = 0;
 128         pfd->events = POLLIN | POLLRDNORM | POLLERR;
 129 }
 130
 131 static inline void __set_sockopt_tpacket(int sock, int val)
 132 {
 133         int ret = setsockopt(sock, SOL_PACKET, PACKET_VERSION, &val, sizeof(val));
 134         if (ret)
 135                 panic("Cannot set tpacketv2!\n");
 136 }
 137
 138 static inline void set_sockopt_tpacket_v2(int sock)
 139 {
 140         __set_sockopt_tpacket(sock, TPACKET_V2);
 141 }
 142
 143 #ifdef HAVE_TPACKET3
 144 static inline void set_sockopt_tpacket_v3(int sock)
 145 {
 146         __set_sockopt_tpacket(sock, TPACKET_V3);
 147 }
 148 #endif
 149
 150 static inline int get_sockopt_tpacket(int sock)
 151 {
 152         int val, ret;
 153         socklen_t len = sizeof(val);
 154
 155         ret = getsockopt(sock, SOL_PACKET, PACKET_VERSION, &val, &len);
 156         if (ret)
 157                 panic("Cannot get tpacket version!\n");
 158
 159         return val;
 160 }
 161
 162 extern void mmap_ring_generic(int sock, struct ring *ring);
 163 extern void alloc_ring_frames_generic(struct ring *ring, int num, size_t size);
 164 extern void bind_ring_generic(int sock, struct ring *ring, int ifindex, bool tx_only);
 165
 166 #endif /* RING_H */