ring_tx.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 TX_RING_H
   8 #define TX_RING_H
   9
  10 #include <stdbool.h>
  11
  12 #include "ring.h"
  13
  14 /* Give userland 10 us time to push packets to the ring */
  15 #define TX_KERNEL_PULL_INT      10
  16
  17 void ring_tx_setup(struct ring *ring, int sock, size_t size, int ifindex,
  18                    bool jumbo_support, bool verbose);
  19 extern void destroy_tx_ring(int sock, struct ring *ring);
  20
  21 static inline int user_may_pull_from_tx(struct tpacket2_hdr *hdr)
  22 {
  23         return !(hdr->tp_status & (TP_STATUS_SEND_REQUEST | TP_STATUS_SENDING));
  24 }
  25
  26 static inline void kernel_may_pull_from_tx(struct tpacket2_hdr *hdr)
  27 {
  28         hdr->tp_status = TP_STATUS_SEND_REQUEST;
  29 }
  30
  31 static inline int pull_and_flush_tx_ring(int sock)
  32 {
  33         int ret;
  34
  35         do {
  36                 ret = sendto(sock, NULL, 0, MSG_DONTWAIT, NULL, 0);
  37         } while (ret == -1 && errno == EINTR);
  38
  39         return ret;
  40 }
  41
  42 static inline int pull_and_flush_tx_ring_wait(int sock)
  43 {
  44         int ret;
  45
  46         do {
  47                 ret = sendto(sock, NULL, 0, 0, NULL, 0);
  48         } while (ret == -1 && errno == EINTR);
  49
  50         return ret;
  51 }
  52
  53 #endif /* TX_RING_H */