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 #ifndef POLLRDNORM
  30 # define POLLRDNORM     0x0040
  31 #endif
  32
  33 union tpacket_uhdr {
  34         struct tpacket_hdr  *h1;
  35         struct tpacket2_hdr *h2;
  36 #ifdef HAVE_TPACKET3
  37         struct tpacket3_hdr *h3;
  38 #endif
  39         void *raw;
  40 };
  41
  42 #ifdef HAVE_TPACKET3
  43 #define tpacket_uhdr(hdr, member, v3)   \
  44         ((v3) ? ((hdr).h3)->member : ((hdr).h2)->member)
  45 #else
  46 #define tpacket_uhdr(hdr, member, v3)   \
  47         (((hdr).h2)->member)
  48 #endif /* HAVE_TPACKET3 */
  49
  50 static inline uint16_t tpacket_uhdr_vlan_tci(union tpacket_uhdr *hdr, bool v3)
  51 {
  52 #ifdef HAVE_TPACKET3
  53         if (v3)
  54                 return hdr->h3->hv1.tp_vlan_tci;
  55 #endif
  56         return 0;
  57 }
  58
  59 static inline uint16_t tpacket_uhdr_vlan_proto(union tpacket_uhdr *hdr, bool v3)
  60 {
  61 #if defined(HAVE_TPACKET3) && defined(TP_STATUS_VLAN_TPID_VALID)
  62         if (v3)
  63                 return hdr->h3->hv1.tp_vlan_tpid;
  64 #endif
  65         return 0;
  66 }
  67
  68 static inline bool tpacket_has_vlan_info(union tpacket_uhdr *hdr)
  69 {
  70         uint32_t valid = 0;
  71
  72 #ifdef TP_STATUS_VLAN_TPID_VALID
  73         valid = TP_STATUS_VLAN_VALID;
  74 #endif
  75
  76         return tpacket_uhdr(*hdr, tp_status, true) &
  77                 (TP_STATUS_VLAN_VALID | valid);
  78 }
  79
  80 struct frame_map {
  81         struct tpacket2_hdr tp_h __aligned_tpacket;
  82         struct sockaddr_ll s_ll __align_tpacket(sizeof(struct tpacket2_hdr));
  83 };
  84
  85 #ifdef HAVE_TPACKET3
  86 struct block_desc {
  87         uint32_t version;
  88         uint32_t offset_to_priv;
  89         struct tpacket_hdr_v1 h1;
  90 };
  91 #endif
  92
  93 struct ring {
  94         struct iovec *frames;
  95         uint8_t *mm_space;
  96         size_t mm_len;
  97         struct sockaddr_ll s_ll;
  98         union {
  99                 struct tpacket_req layout;
 100 #ifdef HAVE_TPACKET3
 101                 struct tpacket_req3 layout3;
 102 #endif
 103                 uint8_t raw;
 104         };
 105 };
 106
 107 static inline void next_rnd_slot(unsigned int *it, struct ring *ring)
 108 {
 109         *it = rand() % ring->layout.tp_frame_nr;
 110 }
 111
 112 static inline size_t ring_size(const char *ifname, size_t size)
 113 {
 114         if (size > 0)
 115                 return size;
 116
 117         /*
 118          * Device bitrate in bytes times two as ring size.
 119          *    Fallback => ~    64,00 MB
 120          *     10 MBit => ~     2,38 MB
 121          *     54 MBit => ~    12,88 MB
 122          *    100 MBit => ~    23,84 MB
 123          *    300 MBit => ~    71,52 MB
 124          *  1.000 MBit => ~   238,42 MB
 125          * 10.000 MBit => ~ 2.384.18 MB
 126          */
 127         size = device_bitrate(ifname);
 128         size = (size * 1000000) / 8;
 129         size = size * 2;
 130         if (size == 0)
 131                 size = 1 << 26;
 132
 133         return round_up_cacheline(size);
 134 }
 135
 136 static inline unsigned int ring_frame_size(struct ring *ring)
 137 {
 138         return ring->layout.tp_frame_size;
 139 }
 140
 141 static inline void ring_verify_layout(struct ring *ring)
 142 {
 143         bug_on(ring->layout.tp_block_size  < ring->layout.tp_frame_size);
 144         bug_on((ring->layout.tp_block_size % ring->layout.tp_frame_size) != 0);
 145         bug_on((ring->layout.tp_block_size % RUNTIME_PAGE_SIZE) != 0);
 146 }
 147
 148 static inline void tpacket_hdr_clone(struct tpacket2_hdr *thdrd,
 149                                      struct tpacket2_hdr *thdrs)
 150 {
 151         thdrd->tp_sec = thdrs->tp_sec;
 152         thdrd->tp_nsec = thdrs->tp_nsec;
 153         thdrd->tp_snaplen = thdrs->tp_snaplen;
 154         thdrd->tp_len = thdrs->tp_len;
 155 }
 156
 157 static inline void prepare_polling(int sock, struct pollfd *pfd)
 158 {
 159         memset(pfd, 0, sizeof(*pfd));
 160         pfd->fd = sock;
 161         pfd->revents = 0;
 162         pfd->events = POLLIN | POLLRDNORM | POLLERR;
 163 }
 164
 165 static inline void __set_sockopt_tpacket(int sock, int val)
 166 {
 167         int ret = setsockopt(sock, SOL_PACKET, PACKET_VERSION, &val, sizeof(val));
 168         if (ret)
 169                 panic("Cannot set tpacketv2!\n");
 170 }
 171
 172 static inline void set_sockopt_tpacket_v2(int sock)
 173 {
 174         __set_sockopt_tpacket(sock, TPACKET_V2);
 175 }
 176
 177 #ifdef HAVE_TPACKET3
 178 static inline void set_sockopt_tpacket_v3(int sock)
 179 {
 180         __set_sockopt_tpacket(sock, TPACKET_V3);
 181 }
 182 #else
 183 static inline void set_sockopt_tpacket_v3(int sock __maybe_unused)
 184 {
 185 }
 186 #endif
 187
 188 static inline int get_sockopt_tpacket(int sock)
 189 {
 190         int val, ret;
 191         socklen_t len = sizeof(val);
 192
 193         ret = getsockopt(sock, SOL_PACKET, PACKET_VERSION, &val, &len);
 194         if (ret)
 195                 panic("Cannot get tpacket version!\n");
 196
 197         return val;
 198 }
 199
 200 extern void mmap_ring_generic(int sock, struct ring *ring);
 201 extern void alloc_ring_frames_generic(struct ring *ring, int num, size_t size);
 202 extern void bind_ring_generic(int sock, struct ring *ring, int ifindex, bool tx_only);
 203
 204 #endif /* RING_H */