TCP and wget implementation.

his is the interface and Kconfig files for introducing TCP and wget into u-boot.

Interfaces are in net.c and net.h, ping is modified to the new ip send interface, and UDP and TCP have shim procedures call map the protocol interface to the ip interface.

The UDP interface is unchanged, and the existing UDP programs need no changes.

All the code is new, and not copied from any source.

The wget command and TCP stack are separately configured in Kconfig, and provisioning wget without TCP will result in a number of error messages. It might be possible to have Kconfig handle dependencies, if so advice is welcome.

Makefile in the net directory is modified by hand. It appears not to be generated by Kconfig. Again advice is welcome.

The rationale behind this change is that UDP file transfers elapsed time is twice the sum of network latency x number of pcckets, and TCP file transfer times are about 4x network latency plus data transit time.

In tests this reduces kernel trnasfer time from about 15 to 20 seconds with tftp on a raspberry pi to about 0.4 seconds with wget.

The raspberry pi as a sink for the kernel runs at about 10 Mbits/sec.

Signed-off-by Duncan Hare <[email protected]>

---

 cmd/Kconfig   |   5 +++
 cmd/net.c     |  13 ++++++++
 include/net.h |  26 ++++++++++++---
 net/Kconfig   |   5 +++
 net/Makefile  |   3 +-
 net/net.c     | 100 ++++++++++++++++++++++++++++++++++++++++++++++++----------
 net/ping.c    |   9 ++----
 7 files changed, 132 insertions(+), 29 deletions(-)

cmd/Kconfig +5 -0

index 5a6afab99b..4e5bac685e 100644
@@ -1035,6 +1035,11 @@ config CMD_ETHSW
          operations such as enabling / disabling a port and
          viewing/maintaining the filtering database (FDB)
 
+config CMD_WGET
+       bool "wget"
+       help
+         Download a kernel, or other files, from a web server over TCP.
+
 endmenu
 
 menu "Misc commands"

cmd/net.c +13 -0

index d7c776aacf..f5c2d0f8ed 100644
@@ -110,6 +110,19 @@ U_BOOT_CMD(
 );
 #endif
 
+#if defined(CONFIG_CMD_WGET)
+static int do_wget(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+       return netboot_common(WGET, cmdtp, argc, argv);
+}
+
+U_BOOT_CMD(
+       wget,   3,      1,      do_wget,
+       "boot image via network using HTTP protocol",
+       "[loadAddress] [[hostIPaddr:]bootfilename]"
+);
+#endif
+
 static void netboot_update_env(void)
 {
        char tmp[22];

include/net.h +22 -4

index 455b48f6c7..7787413816 100644
@@ -24,8 +24,17 @@
  *     The number of receive packet buffers, and the required packet buffer
  *     alignment in memory.
  *
+ *     The nuber of buffers for TCP is used to calculate a static TCP window
+ *     size, becuse TCP window size is a promise to the sending TCP to be able
+ *     to buffer up to the window size of data.
+ *     When the sending TCP has a window size of outstanding unacknowledged
+ *     data, the sending TCP will stop sending.
  */
 
+#if defined(CONFIG_TCP)
+#define CONFIG_SYS_RX_ETH_BUFFER 50    /* For TCP */
+#endif
+
 #ifdef CONFIG_SYS_RX_ETH_BUFFER
 # define PKTBUFSRX     CONFIG_SYS_RX_ETH_BUFFER
 #else

@@ -354,6 +363,8 @@ struct vlan_ethernet_hdr {
 
 #define IPPROTO_ICMP    1      /* Internet Control Message Protocol    */
 #define IPPROTO_UDP    17      /* User Datagram Protocol               */
+#define IPPROTO_TCP     6      /* Transmission Control Protocol        */
+
 
 /*
  *     Internet Protocol (IP) header.

@@ -538,7 +549,7 @@ extern int          net_restart_wrap;       /* Tried all network devices */
 
 enum proto_t {
        BOOTP, RARP, ARP, TFTPGET, DHCP, PING, DNS, NFS, CDP, NETCONS, SNTP,
-       TFTPSRV, TFTPPUT, LINKLOCAL
+       TFTPSRV, TFTPPUT, LINKLOCAL, WGET
 };
 
 extern char    net_boot_file_name[1024];/* Boot File name */

@@ -596,10 +607,10 @@ int net_set_ether(uchar *xet, const uchar *dest_ethaddr, uint prot);
 int net_update_ether(struct ethernet_hdr *et, uchar *addr, uint prot);
 
 /* Set IP header */
-void net_set_ip_header(uchar *pkt, struct in_addr dest, struct in_addr source);
+void net_set_ip_header(uchar *pkt, struct in_addr dest, struct in_addr source,
+                      u16  pkt_len, u8 prot);
 void net_set_udp_header(uchar *pkt, struct in_addr dest, int dport,
-                               int sport, int len);
-
+                       int sport, int len);
 /**
  * compute_ip_checksum() - Compute IP checksum
  *

@@ -670,9 +681,16 @@ static inline void net_send_packet(uchar *pkt, int len)
  * @param sport Source UDP port
  * @param payload_len Length of data after the UDP header
  */
+int net_send_ip_packet(uchar *ether, struct in_addr dest, int dport, int sport,
+                      int payload_len, int proto, u8 action, u32 tcp_seq_num,
+                      u32 tcp_ack_num);
+
 int net_send_udp_packet(uchar *ether, struct in_addr dest, int dport,
                        int sport, int payload_len);
 
+int net_send_tcp_packet(int payload_len, int dport, int sport, u8 action,
+                       u32 tcp_seq_num, u32 tcp_ack_num);
+
 /* Processes a received packet */
 void net_process_received_packet(uchar *in_packet, int len);
 

net/Kconfig +5 -0

index 414c5497c7..625ad291bb 100644
@@ -45,4 +45,9 @@ config BOOTP_VCI_STRING
        default "U-Boot.arm" if ARM
        default "U-Boot"
 
+config TCP
+       bool "Include Subset TCP stack for wget"
+       help
+         TCP protocol support for wget.
+
 endif   # if NET

net/Makefile +0 -0

index ae54eee5af..f83df5b728 100644

net/Makefile +0 -0

 # Disable this warning as it is triggered by:
 # sprintf(buf, index ? "foo%d" : "foo", index)
 # and this is intentional usage.

net/net.c +83 -17

index 4259c9e321..0ce3413cfc 100644
@@ -107,6 +107,12 @@
 #if defined(CONFIG_CMD_SNTP)
 #include "sntp.h"
 #endif
+#if defined(CONFIG_TCP)
+#include "tcp.h"
+#endif
+#if defined(CONFIG_CMD_WGET)
+#include "wget.h"
+#endif
 
 DECLARE_GLOBAL_DATA_PTR;
 

@@ -181,6 +187,7 @@ int         net_ntp_time_offset;
 static uchar net_pkt_buf[(PKTBUFSRX+1) * PKTSIZE_ALIGN + PKTALIGN];
 /* Receive packets */
 uchar *net_rx_packets[PKTBUFSRX];
+
 /* Current UDP RX packet handler */
 static rxhand_f *udp_packet_handler;
 /* Current ARP RX packet handler */

@@ -381,6 +388,9 @@ void net_init(void)
 
                /* Only need to setup buffer pointers once. */
                first_call = 0;
+#if defined(CONFIG_TCP)
+                       tcp_set_tcp_state(TCP_CLOSED);
+#endif
        }
 
        net_init_loop();

@@ -484,6 +494,11 @@ restart:
                        nfs_start();
                        break;
 #endif
+#if defined(CONFIG_CMD_WGET)
+               case WGET:
+                       wget_start();
+                       break;
+#endif
 #if defined(CONFIG_CMD_CDP)
                case CDP:
                        cdp_start();

@@ -777,11 +792,41 @@ void net_set_timeout_handler(ulong iv, thand_f *f)
 }
 
 int net_send_udp_packet(uchar *ether, struct in_addr dest, int dport, int sport,
-               int payload_len)
+                       int payload_len)
+{
+       return net_send_ip_packet(ether, dest, dport, sport, payload_len,
+                                 IPPROTO_UDP, 0, 0, 0);
+}
+
+#if defined(CONFIG_TCP)
+int net_send_tcp_packet(int payload_len, int dport, int sport, u8 action,
+                       u32 tcp_seq_num, u32 tcp_ack_num)
+{
+       return net_send_ip_packet(net_server_ethaddr, net_server_ip, dport,
+                                 sport, payload_len, IPPROTO_TCP, action,
+                                 tcp_seq_num, tcp_ack_num);
+}
+#endif
+
+int net_send_ip_packet(uchar *ether, struct in_addr dest, int dport, int sport,
+                      int payload_len, int proto, u8 action, u32 tcp_seq_num,
+                      u32 tcp_ack_num)
 {
        uchar *pkt;
        int eth_hdr_size;
        int pkt_hdr_size;
+       if (proto == IPPROTO_UDP) {
+               debug_cond(DEBUG_DEV_PKT,
+                          "UDP Send  (to=%pI4, from=%pI4, len=%d)\n",
+                          &dest, &net_ip, payload_len);
+#if defined(CONFIG_TCP)
+
+       } else {
+               debug_cond(DEBUG_DEV_PKT,
+                          "TCP Send  (%pI4, %pI4, len=%d, A=%x)\n",
+                          &dest, &net_ip, payload_len, action);
+#endif
+       }
 
        /* make sure the net_tx_packet is initialized (net_init() was called) */
        assert(net_tx_packet != NULL);

@@ -799,9 +844,22 @@ int net_send_udp_packet(uchar *ether, struct in_addr dest, int dport, int sport,
        pkt = (uchar *)net_tx_packet;
 
        eth_hdr_size = net_set_ether(pkt, ether, PROT_IP);
-       pkt += eth_hdr_size;
-       net_set_udp_header(pkt, dest, dport, sport, payload_len);
-       pkt_hdr_size = eth_hdr_size + IP_UDP_HDR_SIZE;
+#if defined(CONFIG_TCP)
+       if (proto == IPPROTO_UDP) {
+#endif
+               net_set_udp_header(pkt + eth_hdr_size, dest,
+                                  dport, sport, payload_len);
+               pkt_hdr_size = IP_UDP_HDR_SIZE;
+               eth_hdr_size = eth_hdr_size + pkt_hdr_size;
+
+#if defined(CONFIG_TCP)
+       } else {
+               pkt_hdr_size = eth_hdr_size +
+               tcp_set_tcp_header(pkt + eth_hdr_size, dport, sport,
+                                  payload_len, action,
+                                  tcp_seq_num, tcp_ack_num);
+       }
+#endif
 
        /* if MAC address was not discovered yet, do an ARP request */
        if (memcmp(ether, net_null_ethaddr, 6) == 0) {

@@ -1157,9 +1215,6 @@ void net_process_received_packet(uchar *in_packet, int len)
                /* Can't deal with anything except IPv4 */
                if ((ip->ip_hl_v & 0xf0) != 0x40)
                        return;
-               /* Can't deal with IP options (headers != 20 bytes) */
-               if ((ip->ip_hl_v & 0x0f) > 0x05)
-                       return;
                /* Check the Checksum of the header */
                if (!ip_checksum_ok((uchar *)ip, IP_HDR_SIZE)) {
                        debug("checksum bad\n");

@@ -1205,9 +1260,19 @@ void net_process_received_packet(uchar *in_packet, int len)
                 * we send a tftp packet to a dead connection, or when
                 * there is no server at the other end.
                 */
+
                if (ip->ip_p == IPPROTO_ICMP) {
                        receive_icmp(ip, len, src_ip, et);
                        return;
+#if defined(CONFIG_TCP)
+               } else if (ip->ip_p == IPPROTO_TCP) {
+                       debug_cond(DEBUG_DEV_PKT,
+                                  "TCP PH (to=%pI4, from=%pI4, len=%d)\n",
+                                  &dst_ip, &src_ip, len);
+
+                               rxhand_tcp_f((union tcp_build_pkt *)ip, len);
+                       return;
+#endif
                } else if (ip->ip_p != IPPROTO_UDP) {   /* Only UDP packets */
                        return;
                }

@@ -1426,25 +1491,28 @@ int net_update_ether(struct ethernet_hdr *et, uchar *addr, uint prot)
        }
 }
 
-void net_set_ip_header(uchar *pkt, struct in_addr dest, struct in_addr source)
+void net_set_ip_header(uchar *pkt, struct in_addr dest, struct in_addr source,
+                      u16  pkt_len, u8 prot)
 {
        struct ip_udp_hdr *ip = (struct ip_udp_hdr *)pkt;
 
        /*
-        *      Construct an IP header.
+        *      Construct an IP header.
         */
        /* IP_HDR_SIZE / 4 (not including UDP) */
        ip->ip_hl_v  = 0x45;
        ip->ip_tos   = 0;
-       ip->ip_len   = htons(IP_HDR_SIZE);
+       ip->ip_len   = htons(pkt_len);
        ip->ip_id    = htons(net_ip_id++);
-       ip->ip_off   = htons(IP_FLAGS_DFRAG);   /* Don't fragment */
+       ip->ip_off   = htons(IP_FLAGS_DFRAG);   /* Don't fragment */
        ip->ip_ttl   = 255;
+       ip->ip_p     = prot;
        ip->ip_sum   = 0;
        /* already in network byte order */
        net_copy_ip((void *)&ip->ip_src, &source);
        /* already in network byte order */
        net_copy_ip((void *)&ip->ip_dst, &dest);
+       ip->ip_sum  = compute_ip_checksum(ip, IP_HDR_SIZE);
 }
 
 void net_set_udp_header(uchar *pkt, struct in_addr dest, int dport, int sport,

@@ -1460,11 +1528,8 @@ void net_set_udp_header(uchar *pkt, struct in_addr dest, int dport, int sport,
        if (len & 1)
                pkt[IP_UDP_HDR_SIZE + len] = 0;
 
-       net_set_ip_header(pkt, dest, net_ip);
-       ip->ip_len   = htons(IP_UDP_HDR_SIZE + len);
-       ip->ip_p     = IPPROTO_UDP;
-       ip->ip_sum   = compute_ip_checksum(ip, IP_HDR_SIZE);
-
+       net_set_ip_header(pkt, dest, net_ip, IP_UDP_HDR_SIZE + len,
+                         IPPROTO_UDP);
        ip->udp_src  = htons(sport);
        ip->udp_dst  = htons(dport);
        ip->udp_len  = htons(UDP_HDR_SIZE + len);

@@ -1485,7 +1550,8 @@ void copy_filename(char *dst, const char *src, int size)
 
 #if    defined(CONFIG_CMD_NFS)         || \
        defined(CONFIG_CMD_SNTP)        || \
-       defined(CONFIG_CMD_DNS)
+       defined(CONFIG_CMD_DNS)         || \
+       defined(CONFIG_CMD_WGET)
 /*
  * make port a little random (1024-17407)
  * This keeps the math somewhat trivial to compute, and seems to work with

net/ping.c +2 -8

index 9508cf1160..254b646193 100644
@@ -20,16 +20,11 @@ struct in_addr net_ping_ip;
 static void set_icmp_header(uchar *pkt, struct in_addr dest)
 {
        /*
-        *      Construct an IP and ICMP header.
+        *      Construct an ICMP header.
         */
-       struct ip_hdr *ip = (struct ip_hdr *)pkt;
        struct icmp_hdr *icmp = (struct icmp_hdr *)(pkt + IP_HDR_SIZE);
 
-       net_set_ip_header(pkt, dest, net_ip);
-
-       ip->ip_len   = htons(IP_ICMP_HDR_SIZE);
-       ip->ip_p     = IPPROTO_ICMP;
-       ip->ip_sum   = compute_ip_checksum(ip, IP_HDR_SIZE);
+       net_set_ip_header(pkt, dest, net_ip, IP_ICMP_HDR_SIZE, IPPROTO_ICMP);
 
        icmp->type = ICMP_ECHO_REQUEST;
        icmp->code = 0;
--

2.11.0

Quoted 2 lines

selects the LIB_RAND feature since it is required.

Are we lookin at a series of patches, or a concurrent set?

Quoted 2 lines

Quoted 2 lines

selects the LIB_RAND feature since it is required.

Thanks: will be in u-boot/cmd/Kconfig

Quoted 1 line

Are we lookin at a series of patches, or a concurrent set?

At this time a series of three, but I'd take advice on the preferred procedure.

(1)
cmd/Kconfig
cmd/net.c

net/Kconfig
net/net.c
net/ping.c

include/net.h

(2)
net/tcp.c
net/tcp.h
net/Makefile

(3)
net/wget.c
net/wget.h

_______________________________________________
U-Boot mailing list
U-Boot at lists.denx.de
https://lists.denx.de/listinfo/u-boot

Quoted 8 lines

Quoted 1 line

Quoted 1 line

selects the LIB_RAND feature since it is required.

Thanks: will be in u-boot/cmd/Kconfig

Quoted 1 line

Are we lookin at a series of patches, or a concurrent set?

At this time a series of three, but I'd take advice on the preferred procedure.

Remember that the goal is to be atomic.

You should be able to build and use U-Boot after each patch.

Also, any changes to existing code that is not changing behavior but simply making way for new functionality should be done separately. Thanks
-Joe

Quoted 9 lines

Quoted 8 lines

Quoted 1 line

Quoted 1 line

selects the LIB_RAND feature since it is required.

Thanks: will be in u-boot/cmd/Kconfig

Quoted 1 line

Are we lookin at a series of patches, or a concurrent set?

At this time a series of three, but I'd take advice on the preferred procedure.

Quoted 8 lines

Remember that the goal is to be atomic.

You should be able to build and use U-Boot after each patch.

Also, any changes to existing code that is not changing behavior but simply making way for new functionality should be done separately. Thanks
-Joe

A note on this TCP implementation. In TCP the transmitting TCP guarantees delivery of a stream, and the receiving TCP guarantees ordered of delivery of the stream. In this implementation The kernel memory buffer and the TCP sequence number is used to order the stream. for the application, and the application is the kernel itself. wget is not considered the application, and does receive packets "out of order."

This places a constraint on the incoming data stream. All (disordered) packets received before the HTTP header are ignored, which means the sending TCP will re-transmit them. This forced re-transmission could be avoided with a change to reprocess the incoming packet stream back to the first packet received, directly following processing the TCP header.

This behavior was detected and failed downloads fixed in tests downloading Linux kernels from the cloud.

Advice on the reset buffer approach are invited. It requires an interface between the wget application to reset the buffer index.

Joe Thanks, Good advice, based on that the order of 3 patches is:

(1) Prepares the interfaces, no new behavior, CONFIG-TCP is introduced. net/Kconfig
net/net.c
net/ping.c
include/net.h

(2) Introduces TCP
net/tcp.c
net/tcp.h
net/Makefile

(3) Introduces wget, CONFIG-WGET introduced
cmd/Kconfig
cmd/net.c
net/wget.c
net/wget.h

_______________________________________________
U-Boot mailing list
U-Boot at lists.denx.de
https://lists.denx.de/listinfo/u-boot

Quoted 8 lines

A note on this TCP implementation. In TCP the transmitting TCP guarantees delivery of a stream, and the receiving TCP guarantees ordered of delivery of the stream. In this implementation The kernel memory buffer and the TCP sequence number is used to order the stream. for the application, and the application is the kernel itself. wget is not considered the application, and does receive packets "out of order."

It seems like it would be possible to just store off a packet that is ahead of its neighbor and not call any upper handler until the needed packet arrives. Then all upper layers wouldn't need to know about the reordering.

Quoted 3 lines

Advice on the reset buffer approach are invited. It requires an interface between the wget application to reset the buffer index.

Between wget and what? The TCP implementation? It seems like something that should be abstracted from wget.

Quoted 9 lines

Quoted 8 lines

A note on this TCP implementation. In TCP the transmitting TCP guarantees delivery of a stream, and the receiving TCP guarantees ordered of delivery of the stream. In this implementation The kernel memory buffer and the TCP sequence number is used to order the stream. for the application, and the application is the kernel itself. wget is not considered the application, and does receive packets "out of order."

Quoted 4 lines

It seems like it would be possible to just store off a packet that is ahead of its neighbor and not call any upper handler until the needed packet arrives. Then all upper layers wouldn't need to know about the reordering.

There is, for u-boot a large number of buffers used on RX, in order to have a long work queue of kernel data.

CONFIG_SYS_RX_ETH_BUFFER 50

The TCP transmit window is approximately 25 such packets, so overruns are eliminated.

There are about 3300 kernel data packets in this test kernel, so missing a few, 3 to 5, has little impact on elapsed time, and they remain in the input buffer pool ahead of the HTTP header,

The only critical order for this implementation is the TCP header. Without processing the TCP header we do not know the stream address of the first byte of kernel data. It is easy when we know this to map TCP stream address to kernel data offset.

Quoted 6 lines

Quoted 3 lines

Advice on the reset buffer approach are invited. It requires an interface between the wget application to reset the buffer index.

Between wget and what? The TCP implementation? It seems like something that should be abstracted from wget.

wget receives packets without intermediate ordering. Ordering data is a function of wget placing the kernel data at the correct offset, based of TCP stream location, at the correct memory address.

wget is the agent which correctly orders data. There is no socket analogue, the abstraction, and a socket's linked list buffer reordering, which is the generally recognized reordering point for TCP data.

Correct ordering is a primary task of this wget implementation, becuse the destination is a kernel image, and this choice very greatly simplifies the TCP stack, while reducing code complexity, and limits code size.

Reordering would require a new piece of code similar to the fragment assemble piece of code in net.h, and that's an amazing, but complex, piece of code. My objective was to produce something as simple as possible.

The TCP stack delivers packets in the order they come off the wire. Wget puts them in the correct order based on TCP sequence number to build the kernel image, and the TCP sequence number/ack protocol ensures complete delivery of a stream.

Date: Wed, 10 Jan 2018 17:54:07 -0800
Subject: [PATCH] git_msg_1

TCP and wget implementation.

This is the interface and Kconfig files for introducing TCP and wget into u-boot.

Interfaces are in net.c and net.h, ping.c is modified to the new ip send interface, and UDP and TCP have shim procedures call map the protocol interface to the ip interface.

The UDP interface is unchanged, and the existing UDP programs need no changes.

All the code is new, and not copied from any source.

This code should compile.

Next step? git push?

And I do wish I could get git send-mail configureg with yahoo.

Signed-off-by Duncan Hare <[email protected]>

Date: Wed, 10 Jan 2018 17:54:07 -0800
Subject: [PATCH] git_msg_1

TCP and wget implementation.

And I do wish  I could get git send-mail configureg with yahoo.

Signed-off-by Duncan Hare <[email protected]>

________________________________

Hi Duncan,

Quoted 4 lines · Duncan Hare

Date: Wed, 10 Jan 2018 17:54:07 -0800
Subject: [PATCH] git_msg_1

TCP and wget implementation.

Sounds like this should be the title of the series cover letter. I thought we agreed that this should be sent as a series. That means using patman to send all 3 matches to the list as once.

Next step is to get sendmail setup and resend as a series using patman.

Quoted 2 lines

And I do wish I could get git send-mail configureg with yahoo.

https://help.yahoo.com/kb/SLN4724.html

Quoted 3 lines

Signed-off-by Duncan Hare <[email protected]>

Ok, our definition of series differed. I was not thinking concurrent.

Will send next week.

Duncan