tcp_info: support this struct under FreeBSD

Of course these fields are not portable between Linux and FreeBSD,
but they should remain ABI-compatible for future versions of each OS.

Tested on FreeBSD 10.3-RELEASE i386

TCP state names will be another problem...

1 files changed, 195 insertions, 0 deletions

diff --git a/ext/raindrops/tcp_info.c b/ext/raindrops/tcp_info.c
new file mode 100644
index 0000000..dc615f7
--- /dev/null
+++ b/ext/raindrops/tcp_info.c
@@ -0,0 +1,195 @@
+#include <ruby.h>
+#include "extconf.h"
+#include <sys/socket.h>
+#include <netinet/in.h>
+#if defined(HAVE_LINUX_TCP_H)
+#  include <linux/tcp.h>
+#else
+#  if defined(HAVE_NETINET_TCP_H)
+#    include <netinet/tcp.h>
+#  endif
+#  if defined(HAVE_NETINET_TCP_FSM_H)
+#    include <netinet/tcp_fsm.h>
+#  endif
+#endif
+
+#ifdef HAVE_TYPE_STRUCT_TCP_INFO
+#include "my_fileno.h"
+
+CFUNC_tcp_info_tcpi_state
+CFUNC_tcp_info_tcpi_ca_state
+CFUNC_tcp_info_tcpi_retransmits
+CFUNC_tcp_info_tcpi_probes
+CFUNC_tcp_info_tcpi_backoff
+CFUNC_tcp_info_tcpi_options
+CFUNC_tcp_info_tcpi_snd_wscale
+CFUNC_tcp_info_tcpi_rcv_wscale
+CFUNC_tcp_info_tcpi_rto
+CFUNC_tcp_info_tcpi_ato
+CFUNC_tcp_info_tcpi_snd_mss
+CFUNC_tcp_info_tcpi_rcv_mss
+CFUNC_tcp_info_tcpi_unacked
+CFUNC_tcp_info_tcpi_sacked
+CFUNC_tcp_info_tcpi_lost
+CFUNC_tcp_info_tcpi_retrans
+CFUNC_tcp_info_tcpi_fackets
+CFUNC_tcp_info_tcpi_last_data_sent
+CFUNC_tcp_info_tcpi_last_ack_sent
+CFUNC_tcp_info_tcpi_last_data_recv
+CFUNC_tcp_info_tcpi_last_ack_recv
+CFUNC_tcp_info_tcpi_pmtu
+CFUNC_tcp_info_tcpi_rcv_ssthresh
+CFUNC_tcp_info_tcpi_rtt
+CFUNC_tcp_info_tcpi_rttvar
+CFUNC_tcp_info_tcpi_snd_ssthresh
+CFUNC_tcp_info_tcpi_snd_cwnd
+CFUNC_tcp_info_tcpi_advmss
+CFUNC_tcp_info_tcpi_reordering
+CFUNC_tcp_info_tcpi_rcv_rtt
+CFUNC_tcp_info_tcpi_rcv_space
+CFUNC_tcp_info_tcpi_total_retrans
+
+static size_t tcpi_memsize(const void *ptr)
+{
+        return sizeof(struct tcp_info);
+}
+
+static const rb_data_type_t tcpi_type = {
+        "tcp_info",
+        { NULL, RUBY_TYPED_DEFAULT_FREE, tcpi_memsize, /* reserved */ },
+        /* parent, data, [ flags ] */
+};
+
+static VALUE alloc(VALUE klass)
+{
+        struct tcp_info *info;
+
+        return TypedData_Make_Struct(klass, struct tcp_info, &tcpi_type, info);
+}
+
+/*
+ * call-seq:
+ *
+ *        Raindrops::TCP_Info.new(tcp_socket)        -> TCP_Info object
+ *
+ * Reads a TCP_Info object from any given +tcp_socket+.  See the tcp(7)
+ * manpage and /usr/include/linux/tcp.h for more details.
+ */
+static VALUE init(VALUE self, VALUE io)
+{
+        int fd = my_fileno(io);
+        struct tcp_info *info = DATA_PTR(self);
+        socklen_t len = (socklen_t)sizeof(struct tcp_info);
+        int rc = getsockopt(fd, IPPROTO_TCP, TCP_INFO, info, &len);
+
+        if (rc != 0)
+                rb_sys_fail("getsockopt");
+
+        return self;
+}
+
+void Init_raindrops_tcp_info(void)
+{
+        VALUE cRaindrops = rb_define_class("Raindrops", rb_cObject);
+        VALUE cTCP_Info;
+
+        /*
+         * Document-class: Raindrops::TCP_Info
+         *
+         * This is used to wrap "struct tcp_info" as described in tcp(7)
+         * and /usr/include/linux/tcp.h.  The following readers methods
+         * are defined corresponding to the "tcpi_" fields in the
+         * tcp_info struct.
+         *
+         * In particular, the +last_data_recv+ field is useful for measuring
+         * the amount of time a client spent in the listen queue before
+         * +accept()+, but only if +TCP_DEFER_ACCEPT+ is used with the
+         * listen socket (it is on by default in Unicorn).
+         *
+         * - state
+         * - ca_state
+         * - retransmits
+         * - probes
+         * - backoff
+         * - options
+         * - snd_wscale
+         * - rcv_wscale
+         * - rto
+         * - ato
+         * - snd_mss
+         * - rcv_mss
+         * - unacked
+         * - sacked
+         * - lost
+         * - retrans
+         * - fackets
+         * - last_data_sent
+         * - last_ack_sent
+         * - last_data_recv
+         * - last_ack_recv
+         * - pmtu
+         * - rcv_ssthresh
+         * - rtt
+         * - rttvar
+         * - snd_ssthresh
+         * - snd_cwnd
+         * - advmss
+         * - reordering
+         * - rcv_rtt
+         * - rcv_space
+         * - total_retrans
+         *
+         * https://kernel.org/doc/man-pages/online/pages/man7/tcp.7.html
+         */
+        cTCP_Info = rb_define_class_under(cRaindrops, "TCP_Info", rb_cObject);
+        rb_define_alloc_func(cTCP_Info, alloc);
+        rb_define_private_method(cTCP_Info, "initialize", init, 1);
+
+        /*
+         * Document-method: Raindrops::TCP_Info#get!
+         *
+         * call-seq:
+         *
+         *        info = Raindrops::TCP_Info.new(tcp_socket)
+         *        info.get!(tcp_socket)
+         *
+         * Update an existing TCP_Info objects with the latest stats
+         * from the given socket.  This even allows sharing TCP_Info
+         * objects between different sockets to avoid garbage.
+         */
+        rb_define_method(cTCP_Info, "get!", init, 1);
+
+        DEFINE_METHOD_tcp_info_tcpi_state;
+        DEFINE_METHOD_tcp_info_tcpi_ca_state;
+        DEFINE_METHOD_tcp_info_tcpi_retransmits;
+        DEFINE_METHOD_tcp_info_tcpi_probes;
+        DEFINE_METHOD_tcp_info_tcpi_backoff;
+        DEFINE_METHOD_tcp_info_tcpi_options;
+        DEFINE_METHOD_tcp_info_tcpi_snd_wscale;
+        DEFINE_METHOD_tcp_info_tcpi_rcv_wscale;
+        DEFINE_METHOD_tcp_info_tcpi_rto;
+        DEFINE_METHOD_tcp_info_tcpi_ato;
+        DEFINE_METHOD_tcp_info_tcpi_snd_mss;
+        DEFINE_METHOD_tcp_info_tcpi_rcv_mss;
+        DEFINE_METHOD_tcp_info_tcpi_unacked;
+        DEFINE_METHOD_tcp_info_tcpi_sacked;
+        DEFINE_METHOD_tcp_info_tcpi_lost;
+        DEFINE_METHOD_tcp_info_tcpi_retrans;
+        DEFINE_METHOD_tcp_info_tcpi_fackets;
+        DEFINE_METHOD_tcp_info_tcpi_last_data_sent;
+        DEFINE_METHOD_tcp_info_tcpi_last_ack_sent;
+        DEFINE_METHOD_tcp_info_tcpi_last_data_recv;
+        DEFINE_METHOD_tcp_info_tcpi_last_ack_recv;
+        DEFINE_METHOD_tcp_info_tcpi_pmtu;
+        DEFINE_METHOD_tcp_info_tcpi_rcv_ssthresh;
+        DEFINE_METHOD_tcp_info_tcpi_rtt;
+        DEFINE_METHOD_tcp_info_tcpi_rttvar;
+        DEFINE_METHOD_tcp_info_tcpi_snd_ssthresh;
+        DEFINE_METHOD_tcp_info_tcpi_snd_cwnd;
+        DEFINE_METHOD_tcp_info_tcpi_advmss;
+        DEFINE_METHOD_tcp_info_tcpi_reordering;
+        DEFINE_METHOD_tcp_info_tcpi_rcv_rtt;
+        DEFINE_METHOD_tcp_info_tcpi_rcv_space;
+        DEFINE_METHOD_tcp_info_tcpi_total_retrans;
+}
+#endif /* HAVE_STRUCT_TCP_INFO */