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[/] [amber/] [trunk/] [sw/] [boot-loader-ethmac/] [tcp.c] - Rev 69
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/*---------------------------------------------------------------- // // // boot-loader-ethmac.c // // // // This file is part of the Amber project // // http://www.opencores.org/project,amber // // // // Description // // The main functions for the boot loader application. This // // application is embedded in the FPGA's SRAM and is used // // to load larger applications into the DDR3 memory on // // the development board. // // // // Author(s): // // - Conor Santifort, csantifort.amber@gmail.com // // // ////////////////////////////////////////////////////////////////// // // // Copyright (C) 2011 Authors and OPENCORES.ORG // // // // This source file may be used and distributed without // // restriction provided that this copyright statement is not // // removed from the file and that any derivative work contains // // the original copyright notice and the associated disclaimer. // // // // This source file is free software; you can redistribute it // // and/or modify it under the terms of the GNU Lesser General // // Public License as published by the Free Software Foundation; // // either version 2.1 of the License, or (at your option) any // // later version. // // // // This source is distributed in the hope that it will be // // useful, but WITHOUT ANY WARRANTY; without even the implied // // warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR // // PURPOSE. See the GNU Lesser General Public License for more // // details. // // // // You should have received a copy of the GNU Lesser General // // Public License along with this source; if not, download it // // from http://www.opencores.org/lgpl.shtml // // // ----------------------------------------------------------------*/ #include "amber_registers.h" #include "address_map.h" #include "line-buffer.h" #include "timer.h" #include "utilities.h" #include "packet.h" #include "tcp.h" #include "telnet.h" /* Global variables */ int tcp_checksum_errors_g = 0; void parse_tcp_packet(char * buf, packet_t* rx_packet) { int i; int ptr; socket_t* socket; /* TCP Length */ rx_packet->tcp_len = rx_packet->ip_len - rx_packet->ip_header_len*4; rx_packet->tcp_hdr_len = (buf[12]>>4)*4; // Guard against incorrect tcp_hdr_len value if (rx_packet->tcp_hdr_len < rx_packet->tcp_len) rx_packet->tcp_payload_len = rx_packet->tcp_len - rx_packet->tcp_hdr_len; else rx_packet->tcp_payload_len = 0; /* Verify the TCP checksum is correct */ if (tcp_checksum(buf, rx_packet, 0)) { tcp_checksum_errors_g++; goto error_out; } rx_packet->tcp_src_port = buf[0]<<8|buf[1]; rx_packet->tcp_dst_port = buf[2]<<8|buf[3]; rx_packet->tcp_seq = buf[4]<<24|buf[5]<<16|buf[6]<<8|buf[7]; rx_packet->tcp_ack = buf[8]<<24|buf[9]<<16|buf[10]<<8|buf[11]; rx_packet->tcp_flags = buf[13]; rx_packet->tcp_window_size = buf[14]<<8|buf[15]; if (rx_packet->tcp_hdr_len > 20) { /* Get the source time stamp */ parse_tcp_options(buf, rx_packet); } /* -------------------------------------------------- Assign the received packet to a socket -------------------------------------------------- */ /* socket 0 open and matches ? */ if (socket0_g->tcp_connection_state != TCP_CLOSED && socket0_g->rx_packet->tcp_src_port == rx_packet->tcp_src_port) socket = socket0_g; /* socket 1 open and matches ? */ else if (socket1_g->tcp_connection_state != TCP_CLOSED && socket1_g->rx_packet->tcp_src_port == rx_packet->tcp_src_port) socket = socket1_g; /* no matches. Pick an unused socket */ else if (socket0_g->tcp_connection_state == TCP_CLOSED) socket = socket0_g; else if (socket1_g->tcp_connection_state == TCP_CLOSED) socket = socket1_g; else goto error_out; /* Copy the rx_packet structure into the socket */ memcpy(socket->rx_packet, rx_packet, sizeof(packet_t)); tcp_response(buf, socket); error_out: return; } /* Get the tcp source time stamp by walking through the options */ void parse_tcp_options(char * buf, packet_t* rx_packet) { int ptr; ptr = 20; while (ptr < rx_packet->tcp_hdr_len-1) { switch (buf[ptr]) { case 0: ptr=rx_packet->tcp_hdr_len; break; // end of options case 1: ptr++; break; case 2: ptr = ptr + buf[ptr+1]; break; // max segment size case 3: ptr = ptr + buf[ptr+1]; break; // Window Scale case 4: ptr = ptr + buf[ptr+1]; break; // SACK Permitted case 5: ptr = ptr + buf[ptr+1]; break; // SACK case 8: // Time Stamp Option rx_packet->tcp_src_time_stamp = buf[ptr+2]<<24|buf[ptr+3]<<16|buf[ptr+4]<<8|buf[ptr+5]; ptr = ptr + buf[ptr+1]; break; case 28: // User Timeout Option ptr = ptr + buf[ptr+1]; break; default: ptr++; break; } } } void tcp_response(char * buf, socket_t* socket) { socket->packets_received++; /* Mark the ack in the tcp tx packet buffer so the tx packet does not get resent */ if (socket->rx_packet->tcp_flags & 0x10) // ack flag set ? tcp_ack(socket); // Other side requesting to reset a connection ? if (socket->rx_packet->tcp_flags & 0x04) { // RST // Reset the connection socket->tcp_disconnect = 1; } // open a connection else if (socket->tcp_connection_state == TCP_CLOSED) { if (socket->rx_packet->tcp_flags & 0x02) { // SYN // Open connection tcp_open(socket); socket->tcp_connection_state = TCP_PENDING; } /* ACK any FIN received */ else if (socket->rx_packet->tcp_flags & 0x01) // FIN tcp_reply(socket, NULL, 0); } // Sent the first ack packet to establish a connection. // Have just received the second packet from the server else if (socket->tcp_connection_state == TCP_PENDING) { /* Add 1 to the sequence number as a special case to open the connection */ socket->tcp_seq++; socket->tcp_connection_state = TCP_OPEN; } // connection is already open else { /* contains tcp payload */ if (socket->rx_packet->tcp_payload_len != 0) { /* Ack the packet only if the payload length is non-zero */ tcp_reply(socket, NULL, 0); /* Process the tcp contents */ if (socket->rx_packet->tcp_dst_port == TELNET_PORT) /* telnet */ parse_telnet_options(&buf[socket->rx_packet->tcp_hdr_len], socket); } } } void tcp_disconnect(socket_t * socket) { if (socket->tcp_connection_state != TCP_CLOSED) { socket->tcp_connection_state = TCP_CLOSED; socket->telnet_connection_state = TELNET_CLOSED; socket->telnet_options_sent = 0; socket->telnet_sent_opening_message = 0; tcp_reply(socket, NULL, 0); socket->tcp_disconnect = 0; socket->telnet_echo_mode = 0; // reset this setting } } /* Transmit a string of length line_len Suspend interrupts so this process does not get interrupted */ void tcp_tx(socket_t* socket, char* buf, int len) { /* Disable ethmac_int interrupt */ *(unsigned int *) ( ADR_AMBER_IC_IRQ0_ENABLECLR ) = 0x100; tcp_reply(socket, buf, len); /* Enable ethmac_int interrupt */ *(unsigned int *) ( ADR_AMBER_IC_IRQ0_ENABLESET ) = 0x100; } /* TODO merge this into tcp_reply */ void tcp_open(socket_t* socket) { int i, j; unsigned short header_checksum; mac_ip_t target; int ip_length; char * buf; buf = socket->tcp_buf[socket->tcp_current_buf]->buf; target.mac[0] = socket->rx_packet->src_mac[0]; target.mac[1] = socket->rx_packet->src_mac[1]; target.mac[2] = socket->rx_packet->src_mac[2]; target.mac[3] = socket->rx_packet->src_mac[3]; target.mac[4] = socket->rx_packet->src_mac[4]; target.mac[5] = socket->rx_packet->src_mac[5]; target.ip[0] = socket->rx_packet->src_ip[0]; target.ip[1] = socket->rx_packet->src_ip[1]; target.ip[2] = socket->rx_packet->src_ip[2]; target.ip[3] = socket->rx_packet->src_ip[3]; /* Include 20 bytes of tcp options */ ip_length = 20+20+20; /* 20 bytes ip header, 20 bytes tcp header, 20 bytes tcp options */ socket->tcp_buf[socket->tcp_current_buf]->payload_valid = 1; socket->tcp_buf[socket->tcp_current_buf]->ack_received = 0; socket->tcp_buf[socket->tcp_current_buf]->starting_seq = tcp_header(&buf[34], socket, 0, TCP_NEW); socket->tcp_buf[socket->tcp_current_buf]->ending_seq = socket->tcp_buf[socket->tcp_current_buf]->starting_seq + 1; set_timer(&socket->tcp_buf[socket->tcp_current_buf]->resend_time, 500); ip_header(&buf[14], &target, ip_length, 6); /* 20 byes of tcp options, bytes 14 to 33, ip_proto = 6, TCP*/ ethernet_header(buf, &target, 0x0800); /* bytes 0 to 13*/ socket->tcp_buf[socket->tcp_current_buf]->len_bytes = 14+ip_length; strncpy((char*)ETHMAC_TX_BUFFER, buf, socket->tcp_buf[socket->tcp_current_buf]->len_bytes); tx_packet(socket->tcp_buf[socket->tcp_current_buf]->len_bytes); // MAC header, IP header, TCP header, TCP options socket->packets_sent++; /* Pick the next tx buffer to use */ if (socket->tcp_current_buf == TCP_TX_BUFFERS-1) socket->tcp_current_buf=0; else socket->tcp_current_buf++; } void tcp_reply(socket_t* socket, char* telnet_payload, int telnet_payload_length) { int i, j; mac_ip_t target; int ip_length; char * buf; buf = socket->tcp_buf[socket->tcp_current_buf]->buf; target.mac[0] = socket->rx_packet->src_mac[0]; target.mac[1] = socket->rx_packet->src_mac[1]; target.mac[2] = socket->rx_packet->src_mac[2]; target.mac[3] = socket->rx_packet->src_mac[3]; target.mac[4] = socket->rx_packet->src_mac[4]; target.mac[5] = socket->rx_packet->src_mac[5]; target.ip[0] = socket->rx_packet->src_ip[0]; target.ip[1] = socket->rx_packet->src_ip[1]; target.ip[2] = socket->rx_packet->src_ip[2]; target.ip[3] = socket->rx_packet->src_ip[3]; ip_length = 20+20 + telnet_payload_length; /* Copy the payload into the transmit buffer */ if (telnet_payload_length != 0) { for (i=14+ip_length-telnet_payload_length, j=0; i<14+ip_length;i++,j++) { buf[i] = telnet_payload[j]; } } if (telnet_payload_length) socket->tcp_buf[socket->tcp_current_buf]->payload_valid = 1; else socket->tcp_buf[socket->tcp_current_buf]->payload_valid = 0; socket->tcp_buf[socket->tcp_current_buf]->ack_received = 0; socket->tcp_buf[socket->tcp_current_buf]->starting_seq = tcp_header(&buf[34], socket, telnet_payload_length, TCP_NORMAL); socket->tcp_buf[socket->tcp_current_buf]->ending_seq = socket->tcp_buf[socket->tcp_current_buf]->starting_seq + telnet_payload_length; set_timer(&socket->tcp_buf[socket->tcp_current_buf]->resend_time, 500); ip_header(&buf[14], &target, ip_length, 6); /* 20 byes of tcp options, bytes 14 to 33, ip_proto = 6, TCP*/ ethernet_header(buf, &target, 0x0800); /*bytes 0 to 13*/ socket->tcp_buf[socket->tcp_current_buf]->len_bytes = 14+ip_length; strncpy((char*)ETHMAC_TX_BUFFER, buf, socket->tcp_buf[socket->tcp_current_buf]->len_bytes); tx_packet(socket->tcp_buf[socket->tcp_current_buf]->len_bytes); // MAC header, IP header, TCP header, TCP options socket->packets_sent++; /* Pick the next tx buffer to use */ if (socket->tcp_current_buf == TCP_TX_BUFFERS-1) socket->tcp_current_buf=0; else socket->tcp_current_buf++; } /* Find the packets lower than or equal to seq and mark them as acked */ void tcp_ack(socket_t* socket) { int i, ack_valid; unsigned int ack = socket->rx_packet->tcp_ack; unsigned int last_ack = socket->tcp_last_ack; for (i=0;i<TCP_TX_BUFFERS;i=i+1) { if (socket->tcp_buf[i]->payload_valid) { if (ack > last_ack) { ack_valid = (socket->tcp_buf[i]->ending_seq > last_ack) && (socket->tcp_buf[i]->ending_seq <= ack); } else { /* ack is a little after 0, last_ack is a little before 0 */ if (socket->tcp_buf[i]->ending_seq < last_ack) /* ending sequence is a little after 0 */ ack_valid = socket->tcp_buf[i]->ending_seq <= ack; else ack_valid = 1; } if (ack_valid) { socket->tcp_buf[i]->ack_received = 1; if (socket->tcp_buf[i]->ending_seq == ack) break; } } } socket->tcp_last_ack = ack; } /* Check if any tcp packets need to be re-transmitted */ void tcp_retransmit(socket_t* socket) { int i; /* Find the packet that matches seq */ for (i=0;i<TCP_TX_BUFFERS;i=i+1) { if (socket->tcp_buf[i]->payload_valid && !socket->tcp_buf[i]->ack_received) { if (timer_expired(&socket->tcp_buf[i]->resend_time)) { /* Update the timer to trigger again in another little while */ set_timer(&socket->tcp_buf[i]->resend_time, 500); socket->packets_resent++; /* Disable ethmac_int interrupt */ *(unsigned int *) ( ADR_AMBER_IC_IRQ0_ENABLECLR ) = 0x100; strncpy((char*)ETHMAC_TX_BUFFER, socket->tcp_buf[i]->buf, socket->tcp_buf[i]->len_bytes); tx_packet(socket->tcp_buf[i]->len_bytes); // MAC header, IP header, TCP header, TCP options socket->packets_sent++; /* Enable ethmac_int interrupt */ *(unsigned int *) ( ADR_AMBER_IC_IRQ0_ENABLESET ) = 0x100; break; } } } } /* return the starting seq number for this packet */ unsigned int tcp_header(char *buf, socket_t* socket, int payload_length, int options) { unsigned short header_checksum; unsigned int seq_num; unsigned int ack_num; char flags = 0; unsigned short len_tcp; unsigned int starting_seq; /* Source Port */ buf[0] = socket->rx_packet->tcp_dst_port >>8; buf[1] = socket->rx_packet->tcp_dst_port &0xff; /* Destination Port */ buf[2] = socket->rx_packet->tcp_src_port >>8; buf[3] = socket->rx_packet->tcp_src_port &0xff; /* Sequence Number */ /* Increment the sequence number for the next packet */ starting_seq = socket->tcp_seq; socket->tcp_last_seq = socket->tcp_seq; socket->tcp_seq += payload_length; buf[4] = starting_seq>>24; buf[5] = (starting_seq>>16)&0xff; buf[6] = (starting_seq>>8)&0xff; buf[7] = starting_seq&0xff; /* Ack Number */ if (options == TCP_NEW) ack_num = socket->rx_packet->tcp_seq + 1; else if (socket->rx_packet->tcp_flags & 0x01) // FIN // +1 to the final ack ack_num = socket->rx_packet->tcp_seq + 1; else ack_num = socket->rx_packet->tcp_seq + socket->rx_packet->tcp_payload_len; buf[8] = ack_num>>24; buf[9] = (ack_num>>16)&0xff; buf[10] = (ack_num>>8)&0xff; buf[11] = ack_num&0xff; /* Data offset with OPTIONS */ if (options == TCP_NEW) buf[12] = 0xa0; /* upper 4 bits, min is 5 */ else buf[12] = 0x50; /* upper 4 bits, min is 5 */ /* Flags */ flags = 0x10; /* ACK */ if (options == TCP_NEW) /* Valid in first reply in new connection only */ flags |= 0x02; /* SYNchronise */ if (socket->tcp_disconnect) flags |= 0x01; /* FINish */ if (socket->tcp_reset) flags |= 0x04; /* Reset */ buf[13] = flags; /* Window Size */ buf[14] = socket->rx_packet->tcp_window_size >> 8; buf[15] = socket->rx_packet->tcp_window_size & 0xff; /* Checksum */ buf[16] = 0; buf[17] = 0; /* Urgent Pointer */ buf[18] = 0; buf[19] = 0; if (options == TCP_NEW) { /* OPTION: max seg size */ buf[20] = 0x02; buf[21] = 0x04; buf[22] = 0x05; buf[23] = 0xb4; /* OPTION Sack OK */ buf[24] = 0x04; buf[25] = 0x02; /* OPTION Time Stamp */ buf[26] = 0x08; buf[27] = 0x0a; buf[28] = 0x00; buf[29] = 0x61; buf[30] = 0x1f; buf[31] = 0xc6; buf[32] = socket->rx_packet->tcp_src_time_stamp>>24; buf[33] = (socket->rx_packet->tcp_src_time_stamp>>16)&0xff; buf[34] = (socket->rx_packet->tcp_src_time_stamp>>8)&0xff; buf[35] = socket->rx_packet->tcp_src_time_stamp&0xff; /* OPTION: NOP */ buf[36] = 0x01; /* OPTION Window Scale */ buf[37] = 0x03; buf[38] = 0x03; buf[39] = 0x06; } /* Length */ if (options == TCP_NEW) len_tcp = 40+payload_length; else len_tcp = 20+payload_length; /* header checksum */ header_checksum = tcp_checksum(buf, socket->rx_packet, len_tcp); buf[16] = (header_checksum>>8)&0xff; buf[17] = header_checksum&0xff; return starting_seq; } unsigned short tcp_checksum(unsigned char *buf, packet_t* rx_packet, unsigned short len_tcp) { unsigned short prot_tcp=6; unsigned short word16; unsigned long sum; int i; //initialize sum to zero sum=0; if (!len_tcp) len_tcp = rx_packet->tcp_len; // add the TCP pseudo header which contains: // the IP source and destinationn addresses, for (i=0;i<4;i=i+2){ word16 =((rx_packet->src_ip[i]<<8)&0xFF00)+(rx_packet->src_ip[i+1]&0xFF); sum=sum+word16; } for (i=0;i<4;i=i+2){ word16 =((rx_packet->dst_ip[i]<<8)&0xFF00)+(rx_packet->dst_ip[i+1]&0xFF); sum=sum+word16; } // the protocol number and the length of the TCP packet sum = sum + prot_tcp + len_tcp; return header_checksum16(buf, len_tcp, sum); }
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