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 __maybe_unused,
  52                                              bool v3 __maybe_unused)
  53 {
  54 #ifdef HAVE_TPACKET3
  55         if (v3)
  56                 return hdr->h3->hv1.tp_vlan_tci;
  57 #endif
  58         return 0;
  59 }
  60
  61 static inline uint16_t tpacket_uhdr_vlan_proto(union tpacket_uhdr *hdr __maybe_unused,
  62                                                bool v3 __maybe_unused)
  63 {
  64 #if defined(HAVE_TPACKET3) && defined(TP_STATUS_VLAN_TPID_VALID)
  65         if (v3)
  66                 return hdr->h3->hv1.tp_vlan_tpid;
  67 #endif
  68         return 0;
  69 }
  70
  71 static inline bool tpacket_has_vlan_info(union tpacket_uhdr *hdr)
  72 {
  73         uint32_t valid = TP_STATUS_VLAN_VALID;
  74
  75 #ifdef TP_STATUS_VLAN_TPID_VALID
  76         valid |= TP_STATUS_VLAN_TPID_VALID;
  77 #endif
  78
  79         return tpacket_uhdr(*hdr, tp_status, true) & valid;
  80 }
  81
  82 struct frame_map {
  83         struct tpacket2_hdr tp_h __aligned_tpacket;
  84         struct sockaddr_ll s_ll __align_tpacket(sizeof(struct tpacket2_hdr));
  85 };
  86
  87 #ifdef HAVE_TPACKET3
  88 struct block_desc {
  89         uint32_t version;
  90         uint32_t offset_to_priv;
  91         struct tpacket_hdr_v1 h1;
  92 };
  93 #endif
  94
  95 struct ring {
  96         struct iovec *frames;
  97         uint8_t *mm_space;
  98         size_t mm_len;
  99         struct sockaddr_ll s_ll;
 100         union {
 101                 struct tpacket_req layout;
 102 #ifdef HAVE_TPACKET3
 103                 struct tpacket_req3 layout3;
 104 #endif
 105                 uint8_t raw;
 106         };
 107 };
 108
 109 static inline void next_rnd_slot(unsigned int *it, struct ring *ring)
 110 {
 111         *it = rand() % ring->layout.tp_frame_nr;
 112 }
 113
 114 static inline size_t ring_size(const char *ifname, size_t size)
 115 {
 116         if (size > 0)
 117                 return size;
 118
 119         /*
 120          * Device bitrate in bytes times two as ring size.
 121          *    Fallback => ~    64,00 MB
 122          *     10 MBit => ~     2,38 MB
 123          *     54 MBit => ~    12,88 MB
 124          *    100 MBit => ~    23,84 MB
 125          *    300 MBit => ~    71,52 MB
 126          *  1.000 MBit => ~   238,42 MB
 127          * 10.000 MBit => ~ 2.384.18 MB
 128          */
 129         size = device_bitrate(ifname);
 130         size = (size * 1000000) / 8;
 131         size = size * 2;
 132         if (size == 0)
 133                 size = 1 << 26;
 134
 135         return round_up_cacheline(size);
 136 }
 137
 138 static inline unsigned int ring_frame_size(struct ring *ring)
 139 {
 140         return ring->layout.tp_frame_size;
 141 }
 142
 143 static inline void ring_verify_layout(struct ring *ring)
 144 {
 145         bug_on(ring->layout.tp_block_size  < ring->layout.tp_frame_size);
 146         bug_on((ring->layout.tp_block_size % ring->layout.tp_frame_size) != 0);
 147         bug_on((ring->layout.tp_block_size % RUNTIME_PAGE_SIZE) != 0);
 148 }
 149
 150 static inline void shrink_ring_layout_generic(struct ring *ring)
 151 {
 152         ring->layout.tp_block_nr >>= 1;
 153         ring->layout.tp_frame_nr = ring->layout.tp_block_size /
 154                                    ring->layout.tp_frame_size *
 155                                    ring->layout.tp_block_nr;
 156 }
 157
 158 static inline void tpacket_hdr_clone(struct tpacket2_hdr *thdrd,
 159                                      struct tpacket2_hdr *thdrs)
 160 {
 161         thdrd->tp_sec = thdrs->tp_sec;
 162         thdrd->tp_nsec = thdrs->tp_nsec;
 163         thdrd->tp_snaplen = thdrs->tp_snaplen;
 164         thdrd->tp_len = thdrs->tp_len;
 165 }
 166
 167 static inline void prepare_polling(int sock, struct pollfd *pfd)
 168 {
 169         memset(pfd, 0, sizeof(*pfd));
 170         pfd->fd = sock;
 171         pfd->revents = 0;
 172         pfd->events = POLLIN | POLLRDNORM | POLLERR;
 173 }
 174
 175 static inline void __set_sockopt_tpacket(int sock, int val)
 176 {
 177         int ret = setsockopt(sock, SOL_PACKET, PACKET_VERSION, &val, sizeof(val));
 178         if (ret)
 179                 panic("Cannot set tpacketv2!\n");
 180 }
 181
 182 static inline void set_sockopt_tpacket_v2(int sock)
 183 {
 184         __set_sockopt_tpacket(sock, TPACKET_V2);
 185 }
 186
 187 #ifdef HAVE_TPACKET3
 188 static inline void set_sockopt_tpacket_v3(int sock)
 189 {
 190         __set_sockopt_tpacket(sock, TPACKET_V3);
 191 }
 192 #else
 193 static inline void set_sockopt_tpacket_v3(int sock __maybe_unused)
 194 {
 195 }
 196 #endif
 197
 198 static inline int get_sockopt_tpacket(int sock)
 199 {
 200         int val, ret;
 201         socklen_t len = sizeof(val);
 202
 203         ret = getsockopt(sock, SOL_PACKET, PACKET_VERSION, &val, &len);
 204         if (ret)
 205                 panic("Cannot get tpacket version!\n");
 206
 207         return val;
 208 }
 209
 210 extern void setup_ring_layout_generic(struct ring *ring, size_t size,
 211                                       bool jumbo_support);
 212 extern void mmap_ring_generic(int sock, struct ring *ring);
 213 extern void alloc_ring_frames_generic(struct ring *ring, size_t num, size_t size);
 214 extern void bind_ring_generic(int sock, struct ring *ring, int ifindex, bool tx_only);
 215
 216 #endif /* RING_H */