From 7c93eafdd749acb862b53eb36692e4cf952da0c0 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Wed, 12 Aug 2015 08:57:55 -0700 Subject: [PATCH 169/225] tcp: add window scaling support Sometimes we have to provision boxes across regions, such as California to Sweden. The http server has a 10 minute timeout, so if we can't get our 250mb image transferred fast enough our provisioning fails, which is not ideal. So add tcp window scaling on open connections and set the window size to 1mb. With this change we're able to get higher sustained transfers between regions and can transfer our image in well below 10 minutes. Without this patch we'd time out every time halfway through the transfer. Thanks, Signed-off-by: Josef Bacik --- grub-core/net/tcp.c | 42 +++++++++++++++++++++++++++++------------- 1 file changed, 29 insertions(+), 13 deletions(-) diff --git a/grub-core/net/tcp.c b/grub-core/net/tcp.c index e8ad34b84..7d4b82262 100644 --- a/grub-core/net/tcp.c +++ b/grub-core/net/tcp.c @@ -106,6 +106,18 @@ struct tcphdr grub_uint16_t urgent; } GRUB_PACKED; +struct tcp_scale_opt { + grub_uint8_t kind; + grub_uint8_t length; + grub_uint8_t scale; +} GRUB_PACKED; + +struct tcp_synhdr { + struct tcphdr tcphdr; + struct tcp_scale_opt scale_opt; + grub_uint8_t padding; +}; + struct tcp_pseudohdr { grub_uint32_t src; @@ -566,7 +578,7 @@ grub_net_tcp_open (char *server, grub_net_tcp_socket_t socket; static grub_uint16_t in_port = 21550; struct grub_net_buff *nb; - struct tcphdr *tcph; + struct tcp_synhdr *tcph; int i; grub_uint8_t *nbd; grub_net_link_level_address_t ll_target_addr; @@ -635,20 +647,24 @@ grub_net_tcp_open (char *server, } tcph = (void *) nb->data; + grub_memset(tcph, 0, sizeof (*tcph)); socket->my_start_seq = grub_get_time_ms (); socket->my_cur_seq = socket->my_start_seq + 1; - socket->my_window = 8192; - tcph->seqnr = grub_cpu_to_be32 (socket->my_start_seq); - tcph->ack = grub_cpu_to_be32_compile_time (0); - tcph->flags = grub_cpu_to_be16_compile_time ((5 << 12) | TCP_SYN); - tcph->window = grub_cpu_to_be16 (socket->my_window); - tcph->urgent = 0; - tcph->src = grub_cpu_to_be16 (socket->in_port); - tcph->dst = grub_cpu_to_be16 (socket->out_port); - tcph->checksum = 0; - tcph->checksum = grub_net_ip_transport_checksum (nb, GRUB_NET_IP_TCP, - &socket->inf->address, - &socket->out_nla); + socket->my_window = 32768; + tcph->tcphdr.seqnr = grub_cpu_to_be32 (socket->my_start_seq); + tcph->tcphdr.ack = grub_cpu_to_be32_compile_time (0); + tcph->tcphdr.flags = grub_cpu_to_be16_compile_time ((6 << 12) | TCP_SYN); + tcph->tcphdr.window = grub_cpu_to_be16 (socket->my_window); + tcph->tcphdr.urgent = 0; + tcph->tcphdr.src = grub_cpu_to_be16 (socket->in_port); + tcph->tcphdr.dst = grub_cpu_to_be16 (socket->out_port); + tcph->tcphdr.checksum = 0; + tcph->scale_opt.kind = 3; + tcph->scale_opt.length = 3; + tcph->scale_opt.scale = 5; + tcph->tcphdr.checksum = grub_net_ip_transport_checksum (nb, GRUB_NET_IP_TCP, + &socket->inf->address, + &socket->out_nla); tcp_socket_register (socket); -- 2.14.3