ext/raindrops/linux_tcp_info.c

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