ext/raindrops/linux_tcp_info.c

   1 #include <ruby.h>
   2 #include <sys/socket.h>
   3 #include <netinet/in.h>
   4 #include <linux/tcp.h>
   5 #ifdef TCP_INFO
   6 #include "my_fileno.h"
   7
   8 #define TCPI_ATTR_READER(x) \
   9 static VALUE tcp_info_##x(VALUE self) \
  10 { \
  11         struct tcp_info *info = DATA_PTR(self); \
  12         return UINT2NUM((uint32_t)info->tcpi_##x); \
  13 }
  14
  15 TCPI_ATTR_READER(state)
  16 TCPI_ATTR_READER(ca_state)
  17 TCPI_ATTR_READER(retransmits)
  18 TCPI_ATTR_READER(probes)
  19 TCPI_ATTR_READER(backoff)
  20 TCPI_ATTR_READER(options)
  21 TCPI_ATTR_READER(snd_wscale)
  22 TCPI_ATTR_READER(rcv_wscale)
  23 TCPI_ATTR_READER(rto)
  24 TCPI_ATTR_READER(ato)
  25 TCPI_ATTR_READER(snd_mss)
  26 TCPI_ATTR_READER(rcv_mss)
  27 TCPI_ATTR_READER(unacked)
  28 TCPI_ATTR_READER(sacked)
  29 TCPI_ATTR_READER(lost)
  30 TCPI_ATTR_READER(retrans)
  31 TCPI_ATTR_READER(fackets)
  32 TCPI_ATTR_READER(last_data_sent)
  33 TCPI_ATTR_READER(last_ack_sent)
  34 TCPI_ATTR_READER(last_data_recv)
  35 TCPI_ATTR_READER(last_ack_recv)
  36 TCPI_ATTR_READER(pmtu)
  37 TCPI_ATTR_READER(rcv_ssthresh)
  38 TCPI_ATTR_READER(rtt)
  39 TCPI_ATTR_READER(rttvar)
  40 TCPI_ATTR_READER(snd_ssthresh)
  41 TCPI_ATTR_READER(snd_cwnd)
  42 TCPI_ATTR_READER(advmss)
  43 TCPI_ATTR_READER(reordering)
  44 TCPI_ATTR_READER(rcv_rtt)
  45 TCPI_ATTR_READER(rcv_space)
  46 TCPI_ATTR_READER(total_retrans)
  47
  48 static VALUE alloc(VALUE klass)
  49 {
  50         struct tcp_info *info = xmalloc(sizeof(struct tcp_info));
  51
  52         /* Data_Make_Struct has an extra memset 0 which is so wasteful */
  53         return Data_Wrap_Struct(klass, NULL, -1, info);
  54 }
  55
  56 /*
  57  * call-seq:
  58  *
  59  *      Raindrops::TCP_Info.new(tcp_socket)     -> TCP_Info object
  60  *
  61  * Reads a TCP_Info object from any given +tcp_socket+.  See the tcp(7)
  62  * manpage and /usr/include/linux/tcp.h for more details.
  63  */
  64 static VALUE init(VALUE self, VALUE io)
  65 {
  66         int fd = my_fileno(io);
  67         struct tcp_info *info = DATA_PTR(self);
  68         socklen_t len = (socklen_t)sizeof(struct tcp_info);
  69         int rc = getsockopt(fd, IPPROTO_TCP, TCP_INFO, info, &len);
  70
  71         if (rc != 0)
  72                 rb_sys_fail("getsockopt");
  73
  74         return self;
  75 }
  76
  77 void Init_raindrops_linux_tcp_info(void)
  78 {
  79         VALUE cRaindrops = rb_const_get(rb_cObject, rb_intern("Raindrops"));
  80         VALUE cTCP_Info;
  81
  82         /*
  83          * Document-class: Raindrops::TCP_Info
  84          *
  85          * This is used to wrap "struct tcp_info" as described in tcp(7)
  86          * and /usr/include/linux/tcp.h.  The following readers methods
  87          * are defined corresponding to the "tcpi_" fields in the
  88          * tcp_info struct.
  89          *
  90          * In particular, the +last_data_recv+ field is useful for measuring
  91          * the amount of time a client spent in the listen queue before
  92          * +accept()+, but only if +TCP_DEFER_ACCEPT+ is used with the
  93          * listen socket (it is on by default in Unicorn).
  94          *
  95          * - state
  96          * - ca_state
  97          * - retransmits
  98          * - probes
  99          * - backoff
 100          * - options
 101          * - snd_wscale
 102          * - rcv_wscale
 103          * - rto
 104          * - ato
 105          * - snd_mss
 106          * - rcv_mss
 107          * - unacked
 108          * - sacked
 109          * - lost
 110          * - retrans
 111          * - fackets
 112          * - last_data_sent
 113          * - last_ack_sent
 114          * - last_data_recv
 115          * - last_ack_recv
 116          * - pmtu
 117          * - rcv_ssthresh
 118          * - rtt
 119          * - rttvar
 120          * - snd_ssthresh
 121          * - snd_cwnd
 122          * - advmss
 123          * - reordering
 124          * - rcv_rtt
 125          * - rcv_space
 126          * - total_retrans
 127          *
 128          * http://kernel.org/doc/man-pages/online/pages/man7/tcp.7.html
 129          */
 130         cTCP_Info = rb_define_class_under(cRaindrops, "TCP_Info", rb_cObject);
 131         rb_define_alloc_func(cTCP_Info, alloc);
 132         rb_define_private_method(cTCP_Info, "initialize", init, 1);
 133
 134 #define TCPI_DEFINE_METHOD(x) \
 135         rb_define_method(cTCP_Info, #x, tcp_info_##x, 0)
 136
 137         TCPI_DEFINE_METHOD(state);
 138         TCPI_DEFINE_METHOD(ca_state);
 139         TCPI_DEFINE_METHOD(retransmits);
 140         TCPI_DEFINE_METHOD(probes);
 141         TCPI_DEFINE_METHOD(backoff);
 142         TCPI_DEFINE_METHOD(options);
 143         TCPI_DEFINE_METHOD(snd_wscale);
 144         TCPI_DEFINE_METHOD(rcv_wscale);
 145         TCPI_DEFINE_METHOD(rto);
 146         TCPI_DEFINE_METHOD(ato);
 147         TCPI_DEFINE_METHOD(snd_mss);
 148         TCPI_DEFINE_METHOD(rcv_mss);
 149         TCPI_DEFINE_METHOD(unacked);
 150         TCPI_DEFINE_METHOD(sacked);
 151         TCPI_DEFINE_METHOD(lost);
 152         TCPI_DEFINE_METHOD(retrans);
 153         TCPI_DEFINE_METHOD(fackets);
 154         TCPI_DEFINE_METHOD(last_data_sent);
 155         TCPI_DEFINE_METHOD(last_ack_sent);
 156         TCPI_DEFINE_METHOD(last_data_recv);
 157         TCPI_DEFINE_METHOD(last_ack_recv);
 158         TCPI_DEFINE_METHOD(pmtu);
 159         TCPI_DEFINE_METHOD(rcv_ssthresh);
 160         TCPI_DEFINE_METHOD(rtt);
 161         TCPI_DEFINE_METHOD(rttvar);
 162         TCPI_DEFINE_METHOD(snd_ssthresh);
 163         TCPI_DEFINE_METHOD(snd_cwnd);
 164         TCPI_DEFINE_METHOD(advmss);
 165         TCPI_DEFINE_METHOD(reordering);
 166         TCPI_DEFINE_METHOD(rcv_rtt);
 167         TCPI_DEFINE_METHOD(rcv_space);
 168         TCPI_DEFINE_METHOD(total_retrans);
 169 }
 170 #endif /* TCP_INFO */