engines/net: add TCP_MAXSEG setting (mss)

[fio.git] / engines / net.c

diff --git a/engines/net.c b/engines/net.c
index ac5a93c8309b7bd275461cc599ff18f8389947a0..9a327da8a442659f1098711671227102c27126da 100644 (file)
--- a/engines/net.c
+++ b/engines/net.c
@@ -40,6 +40,7 @@ struct netio_options {
        unsigned int nodelay;
        unsigned int ttl;
        unsigned int window_size;
+       unsigned int mss;
        char *intfc;
 };
 
@@ -177,6 +178,18 @@ static struct fio_option options[] = {
                .category = FIO_OPT_C_ENGINE,
                .group  = FIO_OPT_G_NETIO,
        },
+#endif
+#ifdef CONFIG_NET_MSS
+       {
+               .name   = "mss",
+               .lname  = "Maximum segment size",
+               .type   = FIO_OPT_INT,
+               .off1   = offsetof(struct netio_options, mss),
+               .minval = 0,
+               .help   = "Set TCP maximum segment size",
+               .category = FIO_OPT_C_ENGINE,
+               .group  = FIO_OPT_G_NETIO,
+       },
 #endif
        {
                .name   = NULL,
@@ -233,6 +246,30 @@ static int set_window_size(struct thread_data *td, int fd)
 #endif
 }
 
+static int set_mss(struct thread_data *td, int fd)
+{
+#ifdef CONFIG_NET_MSS
+       struct netio_options *o = td->eo;
+       unsigned int mss;
+       int ret;
+
+       if (!o->mss || !is_tcp(o))
+               return 0;
+
+       mss = o->mss;
+       ret = setsockopt(fd, IPPROTO_TCP, TCP_MAXSEG, (void *) &mss,
+                               sizeof(mss));
+       if (ret < 0)
+               td_verror(td, errno, "setsockopt TCP_MAXSEG");
+
+       return ret;
+#else
+       td_verror(td, -EINVAL, "setsockopt TCP_MAXSEG");
+       return -1;
+#endif
+}
+
+
 /*
  * Return -1 for error and 'nr events' for a positive number
  * of events
@@ -655,6 +692,10 @@ static int fio_netio_connect(struct thread_data *td, struct fio_file *f)
                close(f->fd);
                return 1;
        }
+       if (set_mss(td, f->fd)) {
+               close(f->fd);
+               return 1;
+       }
 
        if (is_udp(o)) {
                if (!fio_netio_is_multicast(td->o.filename))
@@ -1101,6 +1142,10 @@ static int fio_netio_setup_listen_inet(struct thread_data *td, short port)
                close(fd);
                return 1;
        }
+       if (set_mss(td, fd)) {
+               close(fd);
+               return 1;
+       }
 
        if (td->o.filename) {
                if (!is_udp(o) || !fio_netio_is_multicast(td->o.filename)) {