[1740] | 1 | //////////////////////////////////////////////////////////////////////////////// |
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| 2 | // Copyright (c) 2004 Xilinx, Inc. All rights reserved. |
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| 3 | // |
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| 4 | // Xilinx, Inc. |
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| 5 | // XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS" AS A |
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| 6 | // COURTESY TO YOU. BY PROVIDING THIS DESIGN, CODE, OR INFORMATION AS |
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| 7 | // ONE POSSIBLE IMPLEMENTATION OF THIS FEATURE, APPLICATION OR |
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| 8 | // STANDARD, XILINX IS MAKING NO REPRESENTATION THAT THIS IMPLEMENTATION |
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| 9 | // IS FREE FROM ANY CLAIMS OF INFRINGEMENT, AND YOU ARE RESPONSIBLE |
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| 10 | // FOR OBTAINING ANY RIGHTS YOU MAY REQUIRE FOR YOUR IMPLEMENTATION. |
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| 11 | // XILINX EXPRESSLY DISCLAIMS ANY WARRANTY WHATSOEVER WITH RESPECT TO |
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| 12 | // THE ADEQUACY OF THE IMPLEMENTATION, INCLUDING BUT NOT LIMITED TO |
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| 13 | // ANY WARRANTIES OR REPRESENTATIONS THAT THIS IMPLEMENTATION IS FREE |
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| 14 | // FROM CLAIMS OF INFRINGEMENT, IMPLIED WARRANTIES OF MERCHANTABILITY |
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| 15 | // AND FITNESS FOR A PARTICULAR PURPOSE. |
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| 16 | // |
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| 17 | // File : tcp.c |
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| 18 | // Date : 2002, March 20. |
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| 19 | // Author : Sathya Thammanur |
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| 20 | // Company: Xilinx |
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| 21 | // Group : Emerging Software Technologies |
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| 22 | // |
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| 23 | // Summary: |
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| 24 | // TCP layer specific functions |
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| 25 | // |
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| 26 | // $Id: tcp.c,v 1.2.8.6 2005/11/15 23:41:10 salindac Exp $ |
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| 27 | // |
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| 28 | //////////////////////////////////////////////////////////////////////////////// |
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| 29 | |
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[1749] | 30 | //////////////////////////////////////////////////////////////////////////////// |
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| 31 | // see copyright.txt for Rice University/Mango Communications modifications |
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| 32 | //////////////////////////////////////////////////////////////////////////////// |
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| 33 | |
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[1745] | 34 | #include <xilnet_xilsock.h> |
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[1740] | 35 | |
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| 36 | #ifndef NULL |
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| 37 | #define NULL 0 |
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| 38 | #endif |
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| 39 | |
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| 40 | struct xilnet_tcp_conn xilnet_tcp_conns[MAX_TCP_CONNS]; |
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| 41 | |
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| 42 | /* |
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| 43 | * tcp packet handler: |
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| 44 | * "buf" is a IP datagram |
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| 45 | * tcp identifies the right connection the pkt is destined for |
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| 46 | * returns "0", if pkt for existing conn |
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| 47 | * returns "-1", if incorrect pkt |
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| 48 | * returns XILSOCK_NEW_CONN for a new conn |
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| 49 | */ |
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| 50 | |
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| 51 | int xilnet_tcp(unsigned char* buf, int len) { |
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| 52 | |
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| 53 | struct xilnet_tcp_conn *curr_conn = NULL; |
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| 54 | struct xilnet_tcp_hdr tcp_req; |
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| 55 | unsigned char* tcp_reply = (sendbuf+LINK_HDR_LEN+(IP_HDR_LEN*4)); |
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| 56 | int tcpdata_in = 0; |
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| 57 | int listen_conn_index = -1; |
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| 58 | int reset = FALSE; |
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| 59 | int i; |
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| 60 | int iplen = 0; |
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| 61 | |
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| 62 | // set the tcp_req to zero |
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| 63 | memset((unsigned char*)&tcp_req, 0, sizeof(struct xilnet_tcp_hdr)); |
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| 64 | |
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| 65 | // cpy buf to tcp_req |
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| 66 | memcpy((unsigned char*)(&tcp_req), (buf+IP_HDR_LEN*4), (TCP_HDR_LEN*4)); |
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| 67 | |
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| 68 | // check for active conns |
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| 69 | for (i = 0; i < MAX_TCP_CONNS; i++) { |
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| 70 | if (xilnet_tcp_conns[i].state != TCP_CLOSED) { |
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| 71 | if ( (xilnet_tcp_conns[i].src_port == tcp_req.dst_port)) { |
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| 72 | if ( (xilnet_tcp_conns[i].dst_port == tcp_req.src_port) && |
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| 73 | (xilnet_tcp_conns[i].dst_ip[0] == buf[IP_SADDR_BASE]) && |
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| 74 | (xilnet_tcp_conns[i].dst_ip[1] == buf[IP_SADDR_BASE+1]) && |
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| 75 | (xilnet_tcp_conns[i].dst_ip[2] == buf[IP_SADDR_BASE+2]) && |
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| 76 | (xilnet_tcp_conns[i].dst_ip[3] == buf[IP_SADDR_BASE+3]) |
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| 77 | ) { |
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| 78 | curr_conn = &(xilnet_tcp_conns[i]); |
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| 79 | break; |
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| 80 | } |
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| 81 | else { |
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| 82 | listen_conn_index = i; |
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| 83 | } |
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| 84 | } |
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| 85 | } |
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| 86 | } |
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| 87 | |
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| 88 | // no activeconn found. check for listening conn |
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| 89 | if (!curr_conn) { |
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| 90 | if (listen_conn_index < 0) { |
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| 91 | reset = TRUE; |
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| 92 | } |
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| 93 | else { |
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| 94 | if (tcp_req.syn) { |
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| 95 | curr_conn = &(xilnet_tcp_conns[listen_conn_index]); |
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| 96 | curr_conn->dst_port = tcp_req.src_port; |
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| 97 | curr_conn->dst_ip[0] = buf[IP_SADDR_BASE] ; |
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| 98 | curr_conn->dst_ip[1] = buf[IP_SADDR_BASE+1]; |
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| 99 | curr_conn->dst_ip[2] = buf[IP_SADDR_BASE+2] ; |
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| 100 | curr_conn->dst_ip[3] = buf[IP_SADDR_BASE+3]; |
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| 101 | } |
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| 102 | else |
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| 103 | reset = TRUE; |
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| 104 | } |
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| 105 | } |
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| 106 | |
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| 107 | // check if reset flag is set and send a reset packet |
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| 108 | if (reset) { |
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| 109 | struct xilnet_tcp_conn conn = {0}; |
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| 110 | conn.src_port = tcp_req.dst_port; |
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| 111 | conn.dst_port = tcp_req.src_port; |
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| 112 | conn.seqno = tcp_req.ack_no; |
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| 113 | conn.ack_seqno = tcp_req.seq_no; |
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| 114 | conn.dst_ip[0] = buf[IP_SADDR_BASE]; |
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| 115 | conn.dst_ip[1] = buf[IP_SADDR_BASE+1]; |
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| 116 | conn.dst_ip[2] = buf[IP_SADDR_BASE+2] ; |
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| 117 | conn.dst_ip[3] = buf[IP_SADDR_BASE+3]; |
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| 118 | memset(sendbuf, 0, LINK_FRAME_LEN); |
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| 119 | xilnet_tcp_send_pkt(&conn, sendbuf+LINK_HDR_LEN+IP_HDR_LEN*4, 0, TCP_RST); |
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| 120 | xilnet_ip_header(sendbuf+LINK_HDR_LEN, (TCP_HDR_LEN*4)+IP_HDR_LEN*4, IP_PROTO_TCP, conn.dst_ip); |
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| 121 | xilnet_eth_send_frame(sendbuf, (TCP_HDR_LEN*4)+IP_HDR_LEN*4+ETH_HDR_LEN, conn.dst_ip, NULL, ETH_PROTO_IP); |
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| 122 | return 0; |
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| 123 | } |
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| 124 | |
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| 125 | tcpdata_in = len - (IP_HDR_LEN*4) - (tcp_req.hdr_len*4); |
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| 126 | |
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| 127 | // check for corr acknum if not a syn packet |
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| 128 | if ( (!tcp_req.syn) && (tcp_req.ack_no != curr_conn->exp_acknum)) { |
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| 129 | print("tcp: incorrect acknum \n"); |
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| 130 | return -1; |
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| 131 | } |
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| 132 | |
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| 133 | switch (curr_conn->state) { |
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| 134 | |
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| 135 | case TCP_LISTEN: |
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| 136 | // incoming SYN;send ACK and Seqno |
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| 137 | if (tcp_req.syn) { |
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| 138 | unsigned char flags = 0; |
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| 139 | unsigned short check = 0; |
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| 140 | |
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| 141 | // set ack_seqno |
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| 142 | curr_conn->ack_seqno = tcp_req.seq_no + 1; |
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| 143 | curr_conn->state = TCP_SYN_RCVD; |
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| 144 | xilsock_sockets[curr_conn->fd].recvbuf.buf = buf; |
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| 145 | xilsock_sockets[curr_conn->fd].recvbuf.size = tcpdata_in; |
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| 146 | return XILSOCK_NEW_CONN; |
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| 147 | } |
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| 148 | return -1; |
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| 149 | break; |
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| 150 | |
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| 151 | case TCP_SYN_RCVD: |
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| 152 | // incoming ACK & no data; |
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| 153 | if (tcp_req.ack && (!tcpdata_in)) { |
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| 154 | // set the ack_seq |
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| 155 | curr_conn->ack_seqno = tcp_req.seq_no + 1; |
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| 156 | curr_conn->seqno = tcp_req.ack_no; |
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| 157 | curr_conn->state = TCP_ESTABLISHED; |
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| 158 | xilsock_sockets[curr_conn->fd].recvbuf.buf = buf; |
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| 159 | xilsock_sockets[curr_conn->fd].recvbuf.size = tcpdata_in; |
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| 160 | return XILSOCK_SYNACK_RCVD; |
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| 161 | } |
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| 162 | return -1; |
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| 163 | break; |
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| 164 | |
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| 165 | case TCP_ESTABLISHED: |
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| 166 | // incoming ACK; data in; |
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| 167 | if (tcp_req.ack && (tcpdata_in)) { |
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| 168 | // set the ack seq |
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| 169 | curr_conn->ack_seqno = tcp_req.seq_no + tcpdata_in; |
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| 170 | curr_conn->seqno = tcp_req.ack_no; |
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| 171 | |
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| 172 | // strip tcp header |
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| 173 | buf = buf + (IP_HDR_LEN*4) +(TCP_HDR_LEN*4); |
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| 174 | |
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| 175 | // update socket corr to this conn |
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| 176 | xilsock_sockets[curr_conn->fd].recvbuf.buf = buf; |
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| 177 | xilsock_sockets[curr_conn->fd].recvbuf.size = tcpdata_in; |
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| 178 | return XILSOCK_TCP_DATA; |
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| 179 | } |
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| 180 | else if (tcp_req.ack && (!tcpdata_in)) { |
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| 181 | // set the ack seq |
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| 182 | curr_conn->ack_seqno = tcp_req.seq_no + 1; |
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| 183 | curr_conn->seqno = tcp_req.ack_no; |
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| 184 | xilsock_sockets[curr_conn->fd].recvbuf.buf = buf; |
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| 185 | xilsock_sockets[curr_conn->fd].recvbuf.size = tcpdata_in; |
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| 186 | return XILSOCK_TCP_ACK; |
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| 187 | } |
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| 188 | return -1; |
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| 189 | break; |
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| 190 | |
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| 191 | case TCP_FIN_WAIT1: |
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| 192 | // wait for fin ack |
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| 193 | if (tcp_req.ack && (!tcpdata_in)) { |
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| 194 | curr_conn->ack_seqno = tcp_req.seq_no + 1; |
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| 195 | curr_conn->seqno = tcp_req.ack_no; |
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| 196 | |
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| 197 | if (tcp_req.fin) { |
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| 198 | |
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| 199 | // send ack for FIN |
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| 200 | memset(sendbuf, 0, LINK_FRAME_LEN); |
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| 201 | xilnet_tcp_send_pkt(curr_conn, sendbuf+LINK_HDR_LEN+IP_HDR_LEN*4, 0, TCP_ACK); |
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| 202 | xilnet_ip_header(sendbuf+LINK_HDR_LEN, (TCP_HDR_LEN*4)+IP_HDR_LEN*4, IP_PROTO_TCP, curr_conn->dst_ip); |
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| 203 | xilnet_eth_send_frame(sendbuf, (TCP_HDR_LEN*4)+IP_HDR_LEN*4+ETH_HDR_LEN, curr_conn->dst_ip, NULL, ETH_PROTO_IP); |
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| 204 | |
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| 205 | // reset tcp conn state |
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| 206 | xilsock_sockets[curr_conn->fd].closed = 1; |
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| 207 | return XILSOCK_CLOSE_CONN; |
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| 208 | } |
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| 209 | curr_conn->state = TCP_FIN_WAIT2; |
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| 210 | xilsock_sockets[curr_conn->fd].recvbuf.buf = buf; |
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| 211 | xilsock_sockets[curr_conn->fd].recvbuf.size = tcpdata_in; |
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| 212 | } |
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| 213 | return -1; |
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| 214 | break; |
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| 215 | |
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| 216 | case TCP_FIN_WAIT2: |
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| 217 | // incoming FIN; |
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| 218 | if (tcp_req.fin) { |
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| 219 | // set the ack seq |
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| 220 | curr_conn->ack_seqno = tcp_req.seq_no + 1; |
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| 221 | curr_conn->seqno = tcp_req.ack_no; |
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| 222 | |
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| 223 | // send ack for FIN |
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| 224 | memset(sendbuf, 0, LINK_FRAME_LEN); |
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| 225 | xilnet_tcp_send_pkt(curr_conn, sendbuf+LINK_HDR_LEN+IP_HDR_LEN*4, 0, TCP_ACK); |
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| 226 | xilnet_ip_header(sendbuf+LINK_HDR_LEN, (TCP_HDR_LEN*4)+IP_HDR_LEN*4, IP_PROTO_TCP, curr_conn->dst_ip); |
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| 227 | xilnet_eth_send_frame(sendbuf, (TCP_HDR_LEN*4)+IP_HDR_LEN*4+ETH_HDR_LEN, curr_conn->dst_ip, NULL, ETH_PROTO_IP); |
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| 228 | |
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| 229 | // reset tcp conn state |
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| 230 | xilsock_sockets[curr_conn->fd].closed = 1; |
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| 231 | return XILSOCK_CLOSE_CONN; |
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| 232 | } |
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| 233 | break; |
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| 234 | default: |
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| 235 | return 0; |
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| 236 | break; |
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| 237 | } |
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| 238 | } |
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| 239 | |
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| 240 | |
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| 241 | /* |
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| 242 | * xilnet_tcp_send_pkt: sends a tcp packet from "conn", with flags |
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| 243 | */ |
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| 244 | |
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| 245 | void xilnet_tcp_send_pkt(struct xilnet_tcp_conn *conn, unsigned char* buf, int len, unsigned char flags) { |
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| 246 | |
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| 247 | unsigned short check = 0; |
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| 248 | |
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| 249 | |
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| 250 | // call tcp_header |
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| 251 | xilnet_tcp_header(conn, buf, len, flags); |
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| 252 | |
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| 253 | // calculate checksum |
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| 254 | check = xilnet_udp_tcp_calc_chksum(buf, len+(TCP_HDR_LEN*4), mb_ip_addr, conn->dst_ip, IP_PROTO_TCP); |
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| 255 | buf[TCP_CHECK_OFF] = (check & 0xff00) >> 8; |
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| 256 | buf[TCP_CHECK_OFF+1] = (check & 0x00ff); |
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| 257 | |
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| 258 | } |
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| 259 | |
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| 260 | |
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| 261 | /* |
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| 262 | * xilnet_tcp_header: creates tcp header |
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| 263 | */ |
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| 264 | void xilnet_tcp_header(struct xilnet_tcp_conn *conn, unsigned char* buf, int len, unsigned char flags) { |
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| 265 | |
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| 266 | struct xilnet_tcp_hdr tcph; |
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| 267 | |
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| 268 | memset((unsigned char*) &tcph, 0, sizeof(struct xilnet_tcp_hdr)); |
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| 269 | if (conn) { |
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| 270 | tcph.src_port = conn->src_port; |
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| 271 | tcph.dst_port = conn->dst_port; |
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| 272 | tcph.seq_no = conn->seqno; |
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| 273 | conn->exp_acknum = conn->seqno + len; |
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| 274 | tcph.ack_no = conn->ack_seqno; |
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| 275 | } |
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| 276 | |
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| 277 | tcph.hdr_len = TCP_HDR_LEN; |
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| 278 | tcph.reserved = 0; |
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| 279 | tcph.urg = (flags & TCP_URG) ? 1:0; |
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| 280 | tcph.ack = (flags & TCP_ACK) ? 1:0; |
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| 281 | tcph.psh = (flags & TCP_PSH) ? 1:0; |
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| 282 | tcph.rst = (flags & TCP_RST) ? 1:0; |
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| 283 | tcph.syn = (flags & TCP_SYN) ? 1:0; |
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| 284 | if (flags & TCP_FIN) { |
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| 285 | tcph.fin = 1; |
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| 286 | tcph.ack_no -= 1; |
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| 287 | } |
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| 288 | |
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| 289 | tcph.window_size[0] = TCP_WND_HIGH; |
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| 290 | tcph.window_size[1] = TCP_WND_LOW; |
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| 291 | tcph.check_sum = 0; |
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| 292 | tcph.urg_ptr = 0; |
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| 293 | |
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| 294 | memcpy(buf, (unsigned char *) &tcph, (TCP_HDR_LEN*4)); |
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| 295 | } |
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| 296 | |
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| 297 | |
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| 298 | /***************************** |
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| 299 | * tcp connection management * |
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| 300 | *****************************/ |
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| 301 | |
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| 302 | /* |
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| 303 | * initialise all tcp conns |
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| 304 | */ |
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| 305 | |
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| 306 | #define XILNET_TCP_SYS_PORT 8000 |
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| 307 | unsigned char istcpinit = 0; |
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| 308 | void xilnet_tcp_init_conns() { |
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| 309 | |
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| 310 | int i; |
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| 311 | |
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| 312 | for (i = 0; i < MAX_TCP_CONNS; i++) { |
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| 313 | xilnet_tcp_conns[i].state = TCP_CLOSED; |
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| 314 | } |
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| 315 | } |
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| 316 | |
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| 317 | |
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| 318 | /* |
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| 319 | * open a tcp conn: |
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| 320 | * opens a new tcp conn and changes state to LISTEN |
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| 321 | * returns connection index if able to open else -1 if not possible |
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| 322 | */ |
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| 323 | |
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| 324 | int xilnet_tcp_open_conn(unsigned short port) { |
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| 325 | |
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| 326 | int i; |
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| 327 | |
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| 328 | if (!istcpinit) { |
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| 329 | xilnet_tcp_init_conns(); |
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| 330 | istcpinit = 1; |
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| 331 | } |
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| 332 | for (i = 0; i < MAX_TCP_CONNS; i++) { |
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| 333 | if (xilnet_tcp_conns[i].state == TCP_CLOSED) |
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| 334 | break; |
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| 335 | } |
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| 336 | |
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| 337 | if (i < MAX_TCP_CONNS) { |
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| 338 | xilnet_tcp_conns[i].src_port = port; |
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| 339 | xilnet_tcp_conns[i].state = TCP_LISTEN; |
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| 340 | xilnet_tcp_conns[i].seqno = 0; |
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| 341 | xilnet_tcp_conns[i].ack_seqno = 0; |
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| 342 | xilnet_tcp_conns[i].exp_acknum = 0; |
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| 343 | return i; |
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| 344 | } |
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| 345 | return -1; |
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| 346 | |
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| 347 | } |
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| 348 | |
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| 349 | |
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| 350 | /* close a tcp conn: |
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| 351 | * closes a tcp conn by changing state to TCP_CLOSED |
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| 352 | * returns 1 if able to close else return -1 |
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| 353 | */ |
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| 354 | |
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| 355 | int xilnet_tcp_close_conn(struct xilnet_tcp_conn *conn) { |
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| 356 | |
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| 357 | int i; |
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| 358 | |
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| 359 | for (i = 0; i < MAX_TCP_CONNS; i++) { |
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| 360 | if ((xilnet_tcp_conns+i) == conn) { |
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| 361 | xilnet_tcp_conns[i].state = TCP_CLOSED; |
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| 362 | return 1; |
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| 363 | } |
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| 364 | } |
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| 365 | return -1; |
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| 366 | } |
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