ring.h

   1 /*
   2  * netsniff-ng - the packet sniffing beast
   3  * Copyright 2009, 2010 Daniel Borkmann.
   4  * Copyright 2014, 2015 Tobias Klauser.
   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
  25 #include "built_in.h"
  26 #include "die.h"
  27 #include "dev.h"
  28 #include "config.h"
  29
  30 #ifndef POLLRDNORM
  31 # define POLLRDNORM     0x0040
  32 #endif
  33
  34 union tpacket_uhdr {
  35         struct tpacket_hdr  *h1;
  36         struct tpacket2_hdr *h2;
  37 #ifdef HAVE_TPACKET3
  38         struct tpacket3_hdr *h3;
  39 #endif
  40         void *raw;
  41 };
  42
  43 #ifdef HAVE_TPACKET3
  44 #define tpacket_uhdr(hdr, member, v3)   \
  45         ((v3) ? ((hdr).h3)->member : ((hdr).h2)->member)
  46 #else
  47 #define tpacket_uhdr(hdr, member, v3)   \
  48         (((hdr).h2)->member)
  49 #endif /* HAVE_TPACKET3 */
  50
  51 static inline uint16_t tpacket_uhdr_vlan_tci(union tpacket_uhdr *hdr, bool v3)
  52 {
  53 #ifdef HAVE_TPACKET3
  54         if (v3)
  55                 return hdr->h3->hv1.tp_vlan_tci;
  56 #endif
  57         return 0;
  58 }
  59
  60 static inline uint16_t tpacket_uhdr_vlan_proto(union tpacket_uhdr *hdr, bool v3)
  61 {
  62 #if defined(HAVE_TPACKET3) && defined(TP_STATUS_VLAN_TPID_VALID)
  63         if (v3)
  64                 return hdr->h3->hv1.tp_vlan_tpid;
  65 #endif
  66         return 0;
  67 }
  68
  69 static inline bool tpacket_has_vlan_info(union tpacket_uhdr *hdr)
  70 {
  71         uint32_t valid = TP_STATUS_VLAN_VALID;
  72
  73 #ifdef TP_STATUS_VLAN_TPID_VALID
  74         valid |= TP_STATUS_VLAN_TPID_VALID;
  75 #endif
  76
  77         return tpacket_uhdr(*hdr, tp_status, true) & 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 shrink_ring_layout_generic(struct ring *ring)
 149 {
 150         ring->layout.tp_block_nr >>= 1;
 151         ring->layout.tp_frame_nr = ring->layout.tp_block_size /
 152                                    ring->layout.tp_frame_size *
 153                                    ring->layout.tp_block_nr;
 154 }
 155
 156 static inline void tpacket_hdr_clone(struct tpacket2_hdr *thdrd,
 157                                      struct tpacket2_hdr *thdrs)
 158 {
 159         thdrd->tp_sec = thdrs->tp_sec;
 160         thdrd->tp_nsec = thdrs->tp_nsec;
 161         thdrd->tp_snaplen = thdrs->tp_snaplen;
 162         thdrd->tp_len = thdrs->tp_len;
 163 }
 164
 165 static inline void prepare_polling(int sock, struct pollfd *pfd)
 166 {
 167         memset(pfd, 0, sizeof(*pfd));
 168         pfd->fd = sock;
 169         pfd->revents = 0;
 170         pfd->events = POLLIN | POLLRDNORM | POLLERR;
 171 }
 172
 173 static inline void __set_sockopt_tpacket(int sock, int val)
 174 {
 175         int ret = setsockopt(sock, SOL_PACKET, PACKET_VERSION, &val, sizeof(val));
 176         if (ret)
 177                 panic("Cannot set tpacketv2!\n");
 178 }
 179
 180 static inline void set_sockopt_tpacket_v2(int sock)
 181 {
 182         __set_sockopt_tpacket(sock, TPACKET_V2);
 183 }
 184
 185 #ifdef HAVE_TPACKET3
 186 static inline void set_sockopt_tpacket_v3(int sock)
 187 {
 188         __set_sockopt_tpacket(sock, TPACKET_V3);
 189 }
 190 #else
 191 static inline void set_sockopt_tpacket_v3(int sock __maybe_unused)
 192 {
 193 }
 194 #endif
 195
 196 static inline int get_sockopt_tpacket(int sock)
 197 {
 198         int val, ret;
 199         socklen_t len = sizeof(val);
 200
 201         ret = getsockopt(sock, SOL_PACKET, PACKET_VERSION, &val, &len);
 202         if (ret)
 203                 panic("Cannot get tpacket version!\n");
 204
 205         return val;
 206 }
 207
 208 extern void setup_ring_layout_generic(int sock, struct ring *ring, size_t size,
 209                                       bool jumbo_support);
 210 extern void mmap_ring_generic(int sock, struct ring *ring);
 211 extern void alloc_ring_frames_generic(struct ring *ring, size_t num, size_t size);
 212 extern void bind_ring_generic(int sock, struct ring *ring, int ifindex, bool tx_only);
 213
 214 #endif /* RING_H */