[U-Boot] [PATCH 2/3] TCP code. All is new.
DH at synoia.com
DH at synoia.com
Sat Feb 24 22:41:49 UTC 2018
From: Duncan Hare <DuncanCHare at yahoo.com>
Passed through patman, which does not like packed headers. But, packed
headers are a requirement to meet protocol header standards.
Signed-off-by: Duncan Hare <DuncanCHare at yahoo.com>
---
net/Makefile | 3 +-
net/tcp.c | 723 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
net/tcp.h | 219 ++++++++++++++++++
3 files changed, 944 insertions(+), 1 deletion(-)
create mode 100644 net/tcp.c
create mode 100644 net/tcp.h
diff --git a/net/Makefile b/net/Makefile
index ae54eee5af..f83df5b728 100644
--- a/net/Makefile
+++ b/net/Makefile
@@ -25,7 +25,8 @@ obj-$(CONFIG_CMD_PING) += ping.o
obj-$(CONFIG_CMD_RARP) += rarp.o
obj-$(CONFIG_CMD_SNTP) += sntp.o
obj-$(CONFIG_CMD_NET) += tftp.o
-
+obj-$(CONFIG_TCP) += tcp.o
+obj-$(CONFIG_CMD_WGET) += wget.o
# Disable this warning as it is triggered by:
# sprintf(buf, index ? "foo%d" : "foo", index)
# and this is intentional usage.
diff --git a/net/tcp.c b/net/tcp.c
new file mode 100644
index 0000000000..22f43e110c
--- /dev/null
+++ b/net/tcp.c
@@ -0,0 +1,723 @@
+/*
+ * Copyright 2017 Duncan Hare, all rights reserved.
+ */
+
+/*
+ * General Desription:
+ *
+ * TCP support for the wget command, for fast file downloading.
+ *
+ * HTTP/TCP Receiver:
+ *
+ * Prequeisites: - own ethernet address
+ * - own IP address
+ * - Server IP address
+ * - HTP client
+ * - Bootfile path & name
+ * We want: - Load the Boot file
+ * Next Step HTTPS?
+ */
+#include <common.h>
+#include <command.h>
+#include <console.h>
+#include <environment.h>
+#include <errno.h>
+#include <net.h>
+#include "tcp.h"
+#include "wget.h"
+
+/* TCP sliding window control */
+/* used by us to request re-TX */
+
+static struct tcp_sack_v tcp_lost;
+
+/* TCP option timestamp */
+static u32 loc_timestamp;
+static u32 rmt_timestamp;
+
+u32 tcp_seq_init;
+u32 tcp_ack_edge;
+u32 tcp_seq_max;
+
+int tcp_activity_count;
+
+/* Search for TCP_SACK and review the
+ * comments before the code section
+ * TCP_SACK is the number of packets
+ * at the front of the stream
+ */
+
+enum pkt_state {PKT, NOPKT};
+struct sack_r {
+ struct sack_edges se;
+ enum pkt_state st;
+};
+
+struct sack_r edge_a[TCP_SACK];
+unsigned int sack_idx;
+unsigned int prev_len;
+
+/* TCP connection state */
+static enum TCP_STATE tcp_state;
+
+/*
+ * An incoming TCP packet handler for the TCP protocol.
+ * There is also a dymanic function pointer for TCP based commads to
+ * receive incoming traffic after the TCP protocol code has done its work.
+ */
+
+/* Current TCP RX packet handler */
+static rxhand_tcp *tcp_packet_handler;
+
+enum TCP_STATE tcp_get_tcp_state(void)
+{
+ return tcp_state;
+}
+
+void tcp_set_tcp_state(enum TCP_STATE new_state)
+{
+ tcp_state = new_state;
+}
+
+void tcp_print_buffer(uchar raw[], int pkt_len, int payload_len,
+ int hdr_len, bool hide)
+{
+ int i;
+
+ for (i = pkt_len - payload_len; i < pkt_len; i++) {
+ if (i <= hdr_len)
+ printf("%02X", raw[i]);
+ else if ((raw[i] > 0x19) && (raw[i] < 0x7f))
+ putc(raw[i]);
+ else if (hide == 0)
+ putc(raw[i]);
+ else
+ printf("%02X", raw[i]);
+ }
+ printf("%s", "\n");
+}
+
+int tcp_find_in_buffer(uchar raw[], int payload_len, uchar field[],
+ int field_len)
+{
+ int i, j;
+
+ for (i = 0; i < payload_len; i++) {
+ if (raw[i] == field[0]) {
+ for (j = 1; j < field_len; j++) {
+ if (raw[i + j] != field[j])
+ break;
+ if (j == field_len)
+ return i;
+ }
+ }
+ }
+ return 0;
+}
+
+static void dummy_handler(uchar *pkt, unsigned int dport,
+ struct in_addr sip, unsigned int sport,
+ unsigned int len)
+{
+}
+
+void tcp_set_tcp_handler(rxhand_tcp *f)
+{
+ debug_cond(DEBUG_INT_STATE, "--- net_loop TCP handler set (%p)\n", f);
+ if (!f)
+ tcp_packet_handler = dummy_handler;
+ else
+ tcp_packet_handler = f;
+}
+
+u16 tcp_set_pseudo_header(uchar *pkt, struct in_addr src, struct in_addr dest,
+ int tcp_len, int pkt_len)
+{
+ union tcp_build_pkt *b = (union tcp_build_pkt *)pkt;
+ int checksum_len;
+
+ /*
+ * Pseudo header
+ *
+ * Zero the byte after the last byte so that the header checksum
+ * will always work.
+ */
+
+ pkt[pkt_len] = 0x00;
+
+ net_copy_ip((void *)&b->ph.p_src, &src);
+ net_copy_ip((void *)&b->ph.p_dst, &dest);
+ b->ph.rsvd = 0x00;
+ b->ph.p = IPPROTO_TCP;
+ b->ph.len = htons(tcp_len);
+ checksum_len = tcp_len + PSEUDO_HDR_SIZE;
+
+ debug_cond(DEBUG_DEV_PKT,
+ "TCP Pesudo Header (to=%pI4, from=%pI4, Len=%d)\n",
+ &b->ph.p_dst, &b->ph.p_src, checksum_len);
+
+ return compute_ip_checksum(pkt + PSEUDO_PAD_SIZE, checksum_len);
+}
+
+int net_set_ack_options(union tcp_build_pkt *b)
+{
+ b->sack.hdr.tcp_hlen = (TCP_HDR_SIZE >> 2) << 4;
+
+ b->sack.t_opt.kind = TCP_O_TS;
+ b->sack.t_opt.len = TCP_OPT_LEN_A;
+ b->sack.t_opt.t_snd = htons(loc_timestamp);
+ b->sack.t_opt.t_rcv = rmt_timestamp;
+ b->sack.sack_v.kind = 0x01;
+ b->sack.sack_v.len = 0x00;
+
+ if (tcp_lost.len > TCP_OPT_LEN_2) {
+ debug_cond(DEBUG_DEV_PKT, "TCP ack opt lost.len %x\n",
+ tcp_lost.len);
+ b->sack.sack_v.len = tcp_lost.len;
+ b->sack.sack_v.kind = TCP_V_SACK;
+ b->sack.sack_v.hill[0].l = htonl(tcp_lost.hill[0].l);
+ b->sack.sack_v.hill[0].r = htonl(tcp_lost.hill[0].r);
+
+ /*
+ * These SACK structures are initialized with NOPs to
+ * provide TCP header alignment padding. There are 4
+ * SACK structures used for both header padding and
+ * internally.
+ */
+
+ b->sack.sack_v.hill[1].l = htonl(tcp_lost.hill[1].l);
+ b->sack.sack_v.hill[1].r = htonl(tcp_lost.hill[1].r);
+ b->sack.sack_v.hill[2].l = htonl(tcp_lost.hill[2].l);
+ b->sack.sack_v.hill[2].r = htonl(tcp_lost.hill[2].r);
+ b->sack.sack_v.hill[3].l = TCP_O_NOP;
+ b->sack.sack_v.hill[3].r = TCP_O_NOP;
+ }
+
+ b->sack.hdr.tcp_hlen = (((TCP_HDR_SIZE + TCP_TSOPT_SIZE
+ + tcp_lost.len + 3) >> 2) << 4);
+ return b->sack.hdr.tcp_hlen >> 2;
+}
+
+void net_set_syn_options(union tcp_build_pkt *b)
+{
+ tcp_lost.len = 0;
+ b->ip.hdr.tcp_hlen = 0xa0;
+
+ b->ip.mss.kind = TCP_O_MSS;
+ b->ip.mss.len = TCP_OPT_LEN_4;
+ b->ip.mss.mss = htons(TCP_MSS);
+ b->ip.scale.kind = TCP_O_SCL;
+ b->ip.scale.scale = TCP_SCALE;
+ b->ip.scale.len = TCP_OPT_LEN_3;
+ b->ip.sack_p.kind = TCP_P_SACK;
+ b->ip.sack_p.len = TCP_OPT_LEN_2;
+ b->ip.t_opt.kind = TCP_O_TS;
+ b->ip.t_opt.len = TCP_OPT_LEN_A;
+ loc_timestamp = get_ticks() % 3072;
+ rmt_timestamp = 0x00000000;
+ b->ip.t_opt.t_snd = 0;
+ b->ip.t_opt.t_rcv = 0x00000000;
+ b->ip.end = TCP_O_END;
+}
+
+int tcp_set_tcp_header(uchar *pkt, int dport, int sport, int payload_len,
+ u8 action, u32 tcp_seq_num, u32 tcp_ack_num)
+{
+ union tcp_build_pkt *b = (union tcp_build_pkt *)pkt;
+ int pkt_hdr_len;
+ int pkt_len;
+ int tcp_len;
+
+ b->ip.hdr.tcp_flags = action;
+ pkt_hdr_len = IP_TCP_HDR_SIZE;
+ b->ip.hdr.tcp_hlen = 0x50; /* Header is 5 32 bit words */
+ /* 4 bits TCP header Length/4*/
+ /* 4 bits Reserved */
+ /* For options */
+ switch (action) {
+ case TCP_SYN:
+ debug_cond(DEBUG_DEV_PKT,
+ "TCP Hdr:SYN (%pI4, %pI4, sq=%d, ak=%d)\n",
+ &net_server_ip, &net_ip,
+ tcp_seq_num, tcp_ack_num);
+ tcp_activity_count = 0;
+ net_set_syn_options(b);
+ tcp_seq_num = 0;
+ tcp_ack_num = 0;
+ pkt_hdr_len = IP_TCP_O_SIZE;
+ if (tcp_state == TCP_SYN_SENT) { /* Too many sins */
+ action = TCP_FIN;
+ tcp_state = TCP_FIN_WAIT_1;
+ } else {
+ tcp_state = TCP_SYN_SENT;
+ }
+ break;
+ case TCP_ACK:
+ pkt_hdr_len = IP_HDR_SIZE +
+ net_set_ack_options(b);
+ b->ip.hdr.tcp_flags = action;
+ debug_cond(DEBUG_DEV_PKT,
+ "TCP Hdr:ACK (%pI4, %pI4, s=%d, a=%d, A=%x)\n",
+ &net_server_ip, &net_ip, tcp_seq_num, tcp_ack_num,
+ action);
+ break;
+ case TCP_FIN:
+ debug_cond(DEBUG_DEV_PKT,
+ "TCP Hdr:FIN (%pI4, %pI4, s=%d, a=%d)\n",
+ &net_server_ip, &net_ip, tcp_seq_num, tcp_ack_num);
+ payload_len = 0;
+ pkt_hdr_len = IP_TCP_HDR_SIZE;
+ tcp_state = TCP_FIN_WAIT_1;
+
+ break; /* Notify connection closing */
+ case (TCP_FIN | TCP_ACK):
+ case ((TCP_FIN | TCP_ACK) | TCP_PUSH):
+ if (tcp_state == TCP_CLOSE_WAIT)
+ tcp_state = TCP_CLOSING;
+ tcp_ack_edge++;
+ debug_cond(DEBUG_DEV_PKT,
+ "TCP Hdr:FIN ACK PSH(%pI4, %pI4, s=%d, a=%d, A=%x)\n",
+ &net_server_ip, &net_ip,
+ tcp_seq_num, tcp_ack_edge, action);
+ /* FALLTHRU */
+ default:
+ pkt_hdr_len = IP_HDR_SIZE +
+ net_set_ack_options(b);
+ b->ip.hdr.tcp_flags = action | TCP_PUSH | TCP_ACK;
+ debug_cond(DEBUG_DEV_PKT,
+ "TCP Hdr:dft (%pI4, %pI4, s=%d, a=%d, A=%x)\n",
+ &net_server_ip, &net_ip,
+ tcp_seq_num, tcp_ack_num, action);
+ }
+
+ pkt_len = pkt_hdr_len + payload_len;
+ tcp_len = pkt_len - IP_HDR_SIZE;
+
+ /*
+ * TCP Header
+ */
+ b->ip.hdr.tcp_ack = htonl(tcp_ack_edge);
+ b->ip.hdr.tcp_src = htons(sport);
+ b->ip.hdr.tcp_dst = htons(dport);
+ b->ip.hdr.tcp_seq = htonl(tcp_seq_num);
+ tcp_seq_num = tcp_seq_num + payload_len;
+
+ /*
+ * TCP window size - TCP header variable tcp_win.
+ * Change tcp_win only if you have an understanding of network
+ * overruun, congestion, TCP segment sizes, TCP windows, TCP scale,
+ * queuing theory and packet buffering. If there are too few buffers,
+ * there will be data loss, recovery may work or the sending TCP,
+ * the server, could abort the stream transmission.
+ * MSS is governed by maximum Ethernet frame langth.
+ * The number of buffers is governed by the desire to have a queue of
+ * full buffers to be processed at the destination to maximize
+ * throughput. Temporary memory use for the boot phase on modern
+ * SOCs is may not be considered a constraint to buffer space, if
+ * it is, thEn the u-boot tftp or nfs kernel netboot should be
+ * considered.
+ */
+
+ b->ip.hdr.tcp_win = htons(PKTBUFSRX * TCP_MSS >> TCP_SCALE);
+
+ b->ip.hdr.tcp_xsum = 0x0000;
+ b->ip.hdr.tcp_ugr = 0x0000;
+
+ b->ip.hdr.tcp_xsum = tcp_set_pseudo_header(pkt, net_ip, net_server_ip,
+ tcp_len, pkt_len);
+
+ /*
+ * IP Header
+ */
+
+ net_set_ip_header((uchar *)&b->ip, net_server_ip, net_ip,
+ pkt_len, IPPROTO_TCP);
+
+ return pkt_hdr_len;
+}
+
+/*
+ * Selective Acknowledgment (Essential for fast stream transfer)
+ *
+ * Before modifying theis section of code, which the author found difficult
+ * to write, please be familiar with the SACK (Selective Acknowledgment) RFCs.
+ */
+
+void tcp_hole(u32 tcp_seq_num, u32 len, u32 tcp_seq_max)
+{
+ unsigned int idx_sack;
+ unsigned int sack_end = TCP_SACK - 1;
+ unsigned int sack_in;
+ unsigned int hill = 0;
+ enum pkt_state expect = PKT;
+
+ u32 seq = tcp_seq_num - tcp_seq_init;
+ u32 hol_l = tcp_ack_edge - tcp_seq_init;
+ u32 hol_r = 0;
+
+ /* Place seq number in correct place */
+
+ if (prev_len == 0)
+ prev_len = len;
+ idx_sack = sack_idx + ((tcp_seq_num - tcp_ack_edge) / prev_len);
+ if (idx_sack < TCP_SACK) {
+ edge_a[idx_sack].se.l = tcp_seq_num;
+ edge_a[idx_sack].se.r = tcp_seq_num + len;
+ edge_a[idx_sack].st = PKT;
+
+ /* The fin (last) packet is not the same lanegth as data packets,
+ * and if it's length is recorded ad used for array index
+ * the arrary index calculations break.
+ */
+ if (prev_len < len)
+ prev_len = len;
+ }
+
+ debug_cond(DEBUG_DEV_PKT,
+ "TCP 1 seq %d, edg %d, len %d, sack_idx %d, sack_end %d\n",
+ seq, hol_l, len, sack_idx, sack_end);
+
+ /* Right edge of contiguous stream, is the left edge of first hill */
+
+ hol_l = tcp_seq_num - tcp_seq_init;
+ hol_r = hol_l + len;
+
+ tcp_lost.len = TCP_OPT_LEN_2;
+
+ debug_cond(DEBUG_DEV_PKT,
+ "TCP 1 in %d, seq %d, pkt_l %d, pkt_r %d, sack_idx %d, sack_end %d\n",
+ idx_sack, seq, hol_l, hol_r, sack_idx, sack_end);
+
+ for (sack_in = sack_idx; (sack_in < sack_end) && (hill < TCP_SACK_HILLS);
+ sack_in++) {
+ switch (expect) {
+ case NOPKT:
+ switch (edge_a[sack_in].st) {
+ case NOPKT:
+ debug_cond(DEBUG_INT_STATE, "N");
+ break;
+ case PKT:
+ debug_cond(DEBUG_INT_STATE, "n");
+ tcp_lost.hill[hill].l =
+ edge_a[sack_in].se.l;
+ tcp_lost.hill[hill].r =
+ edge_a[sack_in].se.r;
+ expect = PKT;
+ break;
+ }
+ break;
+ case PKT:
+ switch (edge_a[sack_in].st) {
+ case NOPKT:
+ debug_cond(DEBUG_INT_STATE, "p");
+ if ((sack_in > sack_idx) &&
+ (hill < TCP_SACK_HILLS)) {
+ hill++;
+ tcp_lost.len += TCP_OPT_LEN_8;
+ }
+ expect = NOPKT;
+ break;
+ case PKT:
+ debug_cond(DEBUG_INT_STATE, "P");
+
+ if (tcp_ack_edge == edge_a[sack_in].se.l) {
+ tcp_ack_edge = edge_a[sack_in].se.r;
+ edge_a[sack_in].st = NOPKT;
+ sack_idx++;
+ } else {
+ if (hill < TCP_SACK_HILLS)
+ tcp_lost.hill[hill].r =
+ edge_a[sack_in].se.r;
+ if (sack_in == sack_end - 1)
+ tcp_lost.hill[hill].r =
+ edge_a[sack_in].se.r;
+ }
+ break;
+ }
+ break;
+ }
+ }
+ debug_cond(DEBUG_INT_STATE, "\n");
+ if (tcp_lost.len <= TCP_OPT_LEN_2)
+ sack_idx = 0;
+}
+
+void tcp_parse_options(uchar *o, int o_len)
+{
+ struct tcp_t_opt *tsopt;
+ uchar *p = o;
+
+ for (p = o; p < (o + o_len); p = p + p[1]) {
+ if (p[1] != 0) {
+ switch (p[0]) {
+ case TCP_O_END:
+ return;
+ case TCP_O_MSS:
+ break;
+ case TCP_O_SCL:
+ break;
+ case TCP_P_SACK:
+ break;
+ case TCP_V_SACK:
+ break;
+ case TCP_O_TS:
+ tsopt = (struct tcp_t_opt *)p;
+ rmt_timestamp = tsopt->t_snd;
+ return;
+ break;
+ }
+ if (p[0] == TCP_O_NOP)
+ p++;
+ } else {
+ return; }
+ }
+}
+
+u8 tcp_state_machine(u8 tcp_flags, u32 *tcp_seq_num, int payload_len)
+{
+ u8 tcp_fin = tcp_flags & TCP_FIN;
+ u8 tcp_syn = tcp_flags & TCP_SYN;
+ u8 tcp_rst = tcp_flags & TCP_RST;
+ u8 tcp_push = tcp_flags & TCP_PUSH;
+ u8 tcp_ack = tcp_flags & TCP_ACK;
+ u8 action = TCP_DATA;
+ int i;
+
+ /*
+ * tcp_flags are examined to determine TX action in a given state
+ * tcp_push is intrepreted to mean "inform the app"
+ * urg, ece, cer and nonce flags are not supported.
+ *
+ * exe and crw are use to signal and confirm knowledge of congestion.
+ * This TCP only sends a file request and acks. If it generates
+ * congestion, the network is broken.
+ */
+
+ debug_cond(DEBUG_INT_STATE, "TCP STATE ENTRY %x\n", action);
+ if (tcp_rst) {
+ action = TCP_DATA;
+ tcp_state = TCP_CLOSED;
+ net_set_state(NETLOOP_FAIL);
+ debug_cond(DEBUG_INT_STATE, "TCP Reset %x\n", tcp_flags);
+ return TCP_RST;
+ }
+
+ switch (tcp_state) {
+ case TCP_CLOSED:
+ debug_cond(DEBUG_INT_STATE, "TCP CLOSED %x\n", tcp_flags);
+ if (tcp_fin)
+ action = TCP_DATA;
+ if (tcp_syn)
+ action = TCP_RST;
+ if (tcp_ack)
+ action = TCP_DATA;
+ break;
+ case TCP_SYN_SENT:
+ debug_cond(DEBUG_INT_STATE, "TCP_SYN_SENT %x, %d\n",
+ tcp_flags, *tcp_seq_num);
+ if (tcp_fin) {
+ action = action | TCP_PUSH;
+ tcp_state = TCP_CLOSE_WAIT;
+ }
+ if (tcp_syn) {
+ action = action | TCP_ACK | TCP_PUSH;
+ if (tcp_ack) {
+ tcp_seq_init = *tcp_seq_num;
+ *tcp_seq_num = *tcp_seq_num + 1;
+ tcp_seq_max = *tcp_seq_num;
+ tcp_ack_edge = *tcp_seq_num;
+ sack_idx = 0;
+ edge_a[sack_idx].se.l = *tcp_seq_num;
+ edge_a[sack_idx].se.r = *tcp_seq_num;
+ prev_len = 0;
+ tcp_state = TCP_ESTABLISHED;
+ for (i = 0; i < TCP_SACK; i++)
+ edge_a[i].st = NOPKT;
+ }
+ } else {
+ if (tcp_ack)
+ action = TCP_DATA;
+ }
+ break;
+ case TCP_ESTABLISHED:
+ debug_cond(DEBUG_INT_STATE,
+ "TCP_ESTABLISHED %x\n", tcp_flags);
+ if (*tcp_seq_num > tcp_seq_max)
+ tcp_seq_max = *tcp_seq_num;
+ if (payload_len > 0) {
+ tcp_hole(*tcp_seq_num, payload_len, tcp_seq_max);
+ tcp_fin = TCP_DATA; /* cause standalone FIN */
+ }
+
+ if ((tcp_fin) && (tcp_lost.len <= TCP_OPT_LEN_2)) {
+ action = action | TCP_FIN | TCP_PUSH | TCP_ACK;
+ tcp_state = TCP_CLOSE_WAIT;
+ } else {
+ if (tcp_ack)
+ action = TCP_DATA;
+ }
+ if (tcp_push)
+ action = action | TCP_PUSH;
+ if (tcp_syn)
+ action = TCP_ACK + TCP_RST;
+ break;
+ case TCP_CLOSE_WAIT:
+ debug_cond(DEBUG_INT_STATE, "TCP_CLOSE_WAIT (%x)\n", tcp_flags);
+ action = TCP_DATA; /* Wait for app */
+ break;
+ case TCP_FIN_WAIT_2:
+ debug_cond(DEBUG_INT_STATE, "TCP_FIN_WAIT_2 (%x)\n", tcp_flags);
+ if (tcp_fin)
+ action = TCP_DATA;
+ if (tcp_syn)
+ action = TCP_DATA;
+ if (tcp_ack) {
+ action = TCP_PUSH | TCP_ACK;
+ tcp_state = TCP_CLOSED;
+ puts("\n");
+ }
+ break;
+ case TCP_FIN_WAIT_1:
+ debug_cond(DEBUG_INT_STATE, "TCP_FIN_WAIT_1 (%x)\n", tcp_flags);
+ if (tcp_fin) {
+ action = TCP_ACK | TCP_FIN;
+ tcp_state = TCP_FIN_WAIT_2;
+ }
+ if (tcp_syn)
+ action = TCP_RST;
+ if (tcp_ack) {
+ tcp_state = TCP_CLOSED;
+ tcp_seq_num = tcp_seq_num + 1;
+ }
+ break;
+ case TCP_CLOSING:
+ debug_cond(DEBUG_INT_STATE, "TCP_CLOSING (%x)\n", tcp_flags);
+ if (tcp_fin)
+ action = TCP_DATA;
+ if (tcp_syn)
+ action = TCP_RST;
+ if (tcp_ack) {
+ action = TCP_PUSH;
+ tcp_state = TCP_CLOSED;
+ puts("\n");
+ }
+ break;
+ }
+ return action;
+}
+
+void rxhand_tcp_f(union tcp_build_pkt *b, unsigned int pkt_len)
+{
+ int tcp_len = pkt_len - IP_HDR_SIZE;
+ u16 tcp_rx_xsum = b->ip.hdr.ip_sum;
+ u8 tcp_action = TCP_DATA;
+ u32 tcp_seq_num;
+ u32 tcp_ack_num;
+ struct in_addr action_and_state;
+
+ int tcp_hdr_len;
+ int payload_len;
+
+ /*
+ * Verify ip header
+ */
+ debug_cond(DEBUG_DEV_PKT,
+ "TCP RX in RX Sum (to=%pI4, from=%pI4, len=%d)\n",
+ &b->ip.hdr.ip_src, &b->ip.hdr.ip_dst, pkt_len);
+
+ debug_cond(DEBUG_DEV_PKT,
+ "In__________________________________________\n");
+
+ b->ip.hdr.ip_src = net_server_ip;
+ b->ip.hdr.ip_dst = net_ip;
+ b->ip.hdr.ip_sum = 0x0000;
+ if (tcp_rx_xsum != compute_ip_checksum(b, IP_HDR_SIZE)) {
+ debug_cond(DEBUG_DEV_PKT,
+ "TCP RX IP xum Error (%pI4, =%pI4, len=%d)\n",
+ &net_ip, &net_server_ip, pkt_len);
+ return;
+ }
+
+ /*
+ * Build Pseudo header and Verify TCP header
+ */
+ tcp_rx_xsum = b->ip.hdr.tcp_xsum;
+ b->ip.hdr.tcp_xsum = 0x0000;
+ if (tcp_rx_xsum != tcp_set_pseudo_header((uchar *)b, b->ip.hdr.ip_src,
+ b->ip.hdr.ip_dst, tcp_len,
+ pkt_len)) {
+ debug_cond(DEBUG_DEV_PKT,
+ "TCP RX TCP xSum Error (%pI4, %pI4, len=%d)\n",
+ &net_ip, &net_server_ip, tcp_len);
+ return;
+ }
+
+ tcp_hdr_len = (b->ip.hdr.tcp_hlen >> 2);
+ payload_len = tcp_len - tcp_hdr_len;
+
+ if (tcp_hdr_len > TCP_HDR_SIZE)
+ tcp_parse_options((uchar *)b + IP_TCP_HDR_SIZE,
+ tcp_hdr_len - TCP_HDR_SIZE);
+ /*
+ * Incoming sequence and ack numbers are server's view of the numbers.
+ * The app must swap the numbers when responding.
+ */
+
+ tcp_seq_num = ntohl(b->ip.hdr.tcp_seq);
+ tcp_ack_num = ntohl(b->ip.hdr.tcp_ack);
+
+ /*
+ * Send first packet send from server as first to app
+ * Other packets could be ordered, but are currently not ordered.
+ */
+
+ tcp_action = tcp_state_machine(b->ip.hdr.tcp_flags,
+ &tcp_seq_num, payload_len);
+
+ /*
+ * State altering command to be sent.
+ * The packet sequence and ack numbers are in the tcp_seq_num
+ * and tcp_ack_num variables. The current packet, its position
+ * in the date stream, is the in the range of those variables.
+ *
+ * In the "application push" invocation the TCP header with all
+ * its information is pointed to by the packet pointer, and the
+ * other variable "repurposed" (or misused) to carry sequence numbers
+ * and TCP state.
+ *
+ * TCP_PUSH from the state machine with a payload length of 0 is a
+ * connect or disconnect event
+ */
+
+ tcp_activity_count++;
+ if (tcp_activity_count > TCP_ACTIVITY) {
+ puts("| ");
+ tcp_activity_count = 0;
+ }
+
+ if ((tcp_action & TCP_PUSH) || (payload_len > 0)) {
+ debug_cond(DEBUG_DEV_PKT,
+ "TCP Notify (action=%x, Seq=%d,Ack=%d,Pay%d)\n",
+ tcp_action, tcp_seq_num, tcp_ack_num, payload_len);
+
+ action_and_state.s_addr = tcp_action;
+ (*tcp_packet_handler) ((uchar *)b + pkt_len - payload_len,
+ tcp_seq_num, action_and_state,
+ tcp_ack_num, payload_len);
+
+ } else if (tcp_action != TCP_DATA) {
+ debug_cond(DEBUG_DEV_PKT,
+ "TCP Action (action=%x,Seq=%d,Ack=%d,Pay=%d)\n",
+ tcp_action, tcp_seq_num, tcp_ack_num, payload_len);
+
+ /*
+ * Warning: Incoming Seq & Ack sequence numbers are transposed here
+ * to outgoing Seq & Ack sequence numbers
+ */
+
+ net_send_tcp_packet(0, ntohs(b->ip.hdr.tcp_src),
+ ntohs(b->ip.hdr.tcp_dst),
+ (tcp_action & (~TCP_PUSH)),
+ tcp_seq_num, tcp_ack_num);
+ }
+}
diff --git a/net/tcp.h b/net/tcp.h
new file mode 100644
index 0000000000..4d50390c6d
--- /dev/null
+++ b/net/tcp.h
@@ -0,0 +1,219 @@
+/*
+ * TCP Support for file transfer.
+ *
+ * Copyright 2017 Duncan Hare, All rights reserved.
+ *
+ * History
+ * 10/2017 Initial code
+ */
+
+#define TCP_ACTIVITY 127 /* Activity on down loading */
+
+struct ip_tcp_hdr {
+ u8 ip_hl_v; /* header length and version */
+ u8 ip_tos; /* type of service */
+ u16 ip_len; /* total length */
+ u16 ip_id; /* identification */
+ u16 ip_off; /* fragment offset field */
+ u8 ip_ttl; /* time to live */
+ u8 ip_p; /* protocol */
+ u16 ip_sum; /* checksum */
+ struct in_addr ip_src; /* Source IP address */
+ struct in_addr ip_dst; /* Destination IP address */
+ u16 tcp_src; /* TCP source port */
+ u16 tcp_dst; /* TCP destination port */
+ u32 tcp_seq; /* TCP sequence number */
+ u32 tcp_ack; /* TCP Acknowledgment number */
+ u8 tcp_hlen; /* 4 bits TCP header Length/4 */
+ /* 4 bits Reserved */
+ /* 2 more bits reserved */
+ u8 tcp_flags; /* see defines */
+ u16 tcp_win; /* TCP windows size */
+ u16 tcp_xsum; /* Checksum */
+ u16 tcp_ugr; /* Pointer to urgent data */
+} __packed;
+
+#define IP_TCP_HDR_SIZE (sizeof(struct ip_tcp_hdr))
+#define TCP_HDR_SIZE (IP_TCP_HDR_SIZE - IP_HDR_SIZE)
+
+#define TCP_DATA 0x00 /* Data Packet - internal use only */
+#define TCP_FIN 0x01 /* Finish flag */
+#define TCP_SYN 0x02 /* Synch (start) flag */
+#define TCP_RST 0x04 /* reset flag */
+#define TCP_PUSH 0x08 /* Push - Notify app */
+#define TCP_ACK 0x10 /* Acknowledgment of data received */
+#define TCP_URG 0x20 /* Urgent */
+#define TCP_ECE 0x40 /* Congestion control */
+#define TCP_CWR 0x80 /* Congestion Control */
+
+/*
+ * TCP header options, Seq, MSS, and SACK
+ */
+
+#define TCP_SACK 32 /* Number of packets analyzed */
+ /* on leading edge of stream */
+
+#define TCP_O_END 0x00 /* End of option list */
+#define TCP_1_NOP 0x01 /* Single padding NOP */
+#define TCP_O_NOP 0x01010101 /* NOPs pad to 32 bit boundary */
+#define TCP_O_MSS 0x02 /* MSS Size option */
+#define TCP_O_SCL 0x03 /* Window Scale option */
+#define TCP_P_SACK 0x04 /* SACK permitted */
+#define TCP_V_SACK 0x05 /* SACK values */
+#define TCP_O_TS 0x08 /* Timestanp option */
+#define TCP_OPT_LEN_2 0x02
+#define TCP_OPT_LEN_3 0x03
+#define TCP_OPT_LEN_4 0x04
+#define TCP_OPT_LEN_6 0x06
+#define TCP_OPT_LEN_8 0x08
+#define TCP_OPT_LEN_A 0x0a /* Timestamp Length */
+
+/*
+ * Please reviw the warning in net.c about these two paraeters.
+ * They are part of a promise of RX buffer size to the sending TCP
+ */
+
+#define TCP_MSS 1460 /* Max segment size - 1460 */
+#define TCP_SCALE 0x01 /* Scale 1 */
+
+struct tcp_mss { /* TCP Mex Segment size */
+ u8 kind; /* 0x02 */
+ u8 len; /* 0x04 */
+ u16 mss; /* 1460 - Max segment size */
+} __packed;
+
+struct tcp_scale { /* TCP Windows Scale */
+ u8 kind; /* 0x03 */
+ u8 len; /* 0x03 */
+ u8 scale; /* win shift fat fast networks */
+} __packed;
+
+struct tcp_sack_p { /* SACK permitted */
+ u8 kind; /* 0x04 */
+ u8 len; /* Length */
+} __packed;
+
+struct sack_edges {
+ u32 l;
+ u32 r;
+} __packed;
+
+#define TCP_SACK_SIZE (sizeof(struct sack_edges))
+
+#define TCP_SACK_HILLS 4
+
+struct tcp_sack_v {
+ u8 kind; /* 0x05 */
+ u8 len; /* Length */
+ struct sack_edges hill[TCP_SACK_HILLS]; /* L & R widow edges */
+} __packed;
+
+struct tcp_t_opt { /* TCP time stamps option */
+ u8 kind; /* 0x08 */
+ u8 len; /* 0x0a */
+ u32 t_snd; /* Sender timestamp */
+ u32 t_rcv; /* Receiver timestamp */
+} __packed;
+
+#define TCP_TSOPT_SIZE (sizeof(struct tcp_t_opt))
+
+/*
+ * ip tcp structure with options
+ */
+
+struct ip_tcp_hdr_o {
+ struct ip_tcp_hdr hdr;
+ struct tcp_mss mss;
+ struct tcp_scale scale;
+ struct tcp_sack_p sack_p;
+ struct tcp_t_opt t_opt;
+ u8 end;
+} __packed;
+
+#define IP_TCP_O_SIZE (sizeof(struct ip_tcp_hdr_o))
+
+struct ip_tcp_hdr_s {
+ struct ip_tcp_hdr hdr;
+ struct tcp_t_opt t_opt;
+ struct tcp_sack_v sack_v;
+ u8 end;
+} __packed;
+
+#define IP_TCP_SACK_SIZE (sizeof(struct ip_tcp_hdr_s))
+
+/*
+ * TCP pseudo header definitions
+ */
+#define PSEUDO_PAD_SIZE 8
+
+struct pseudo_hdr {
+ u8 padding[PSEUDO_PAD_SIZE]; /* pseudo hdr size = ip_tcp hdr size */
+ struct in_addr p_src;
+ struct in_addr p_dst;
+ u8 rsvd;
+ u8 p;
+ u16 len;
+} __packed;
+
+#define PSEUDO_HDR_SIZE (sizeof(struct pseudo_hdr)) - PSEUDO_PAD_SIZE
+
+/*
+ * union for building IP/TCP packet.
+ * build Pseudo header in packed bufferfirst, calculate TCP checksum
+ * then build IP header in packe buffer.
+ */
+
+union tcp_build_pkt {
+ struct pseudo_hdr ph;
+ struct ip_tcp_hdr_o ip;
+ struct ip_tcp_hdr_s sack;
+ uchar raw[1600];
+} __packed;
+
+/*
+ * TCP STATE MACHINE STATES FOR SOCKET
+ */
+
+enum TCP_STATE {
+ TCP_CLOSED, /* Need to send SYN to connect */
+ TCP_SYN_SENT, /* Trying to connect, waiting for SYN ACK */
+ TCP_ESTABLISHED, /* both server & client have a connection */
+ TCP_CLOSE_WAIT, /* Rec FIN, passed to app for FIN, ACK rsp*/
+ TCP_CLOSING, /* Rec FIN, sent FIN, ACK waiting for ACK */
+ TCP_FIN_WAIT_1, /* Sendt FIN waiting for response */
+ TCP_FIN_WAIT_2 /* Rec ACK from FIN sent, waitng for FIN */
+};
+
+int tcp_find_in_buffer(uchar raw[], int payload_len, uchar field[],
+ int field_len);
+void tcp_print_buffer(uchar raw[], int pkt_len, int payload_len,
+ int hdr_len, bool hide);
+enum TCP_STATE tcp_get_tcp_state(void);
+void tcp_set_tcp_state(enum TCP_STATE new_state);
+int tcp_set_tcp_header(uchar *pkt, int dport, int sport, int payload_len,
+ u8 action, u32 tcp_seq_num, u32 tcp_ack_num);
+
+/*
+ * An incoming packet handler.
+ * @param pkt pointer to the application packet
+ * @param dport destination UDP port
+ * @param sip source IP address
+ * @param sport source UDP port
+ * @param len packet length
+ */
+typedef void rxhand_tcp(uchar *pkt, unsigned int dport,
+ struct in_addr sip, unsigned int sport,
+ unsigned int len);
+void tcp_set_tcp_handler(rxhand_tcp *f);
+
+void rxhand_tcp_f(union tcp_build_pkt *b, unsigned int len);
+
+/*
+ * An incoming TCP packet handler for the TCP protocol.
+ * There is also a dymanic function pointer for TCP based commads to
+ * receive incoming traffic after the TCP protocol code has done its work.
+ */
+
+void rxhand_action(u8 tcp_action, int payload_len, u32 tcp_seq_num,
+ u32 tcp_ack_num, unsigned int pkt_len,
+ union tcp_build_pkt *b);
--
2.11.0
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