1 /* 2 * FreeRTOS+TCP <DEVELOPMENT BRANCH> 3 * Copyright (C) 2022 Amazon.com, Inc. or its affiliates. All Rights Reserved. 4 * 5 * SPDX-License-Identifier: MIT 6 * 7 * Permission is hereby granted, free of charge, to any person obtaining a copy of 8 * this software and associated documentation files (the "Software"), to deal in 9 * the Software without restriction, including without limitation the rights to 10 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of 11 * the Software, and to permit persons to whom the Software is furnished to do so, 12 * subject to the following conditions: 13 * 14 * The above copyright notice and this permission notice shall be included in all 15 * copies or substantial portions of the Software. 16 * 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS 19 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR 20 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER 21 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 22 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 23 * 24 * http://aws.amazon.com/freertos 25 * http://www.FreeRTOS.org 26 */ 27 28 #ifndef FREERTOS_TCP_TRANSMISSION_H 29 #define FREERTOS_TCP_TRANSMISSION_H 30 31 /* *INDENT-OFF* */ 32 #ifdef __cplusplus 33 extern "C" { 34 #endif 35 /* *INDENT-ON* */ 36 37 /* 38 * Either sends a SYN or calls prvTCPSendRepeated (for regular messages). 39 */ 40 int32_t prvTCPSendPacket( FreeRTOS_Socket_t * pxSocket ); 41 42 /* 43 * Try to send a series of messages. 44 */ 45 int32_t prvTCPSendRepeated( FreeRTOS_Socket_t * pxSocket, 46 NetworkBufferDescriptor_t ** ppxNetworkBuffer ); 47 48 /* 49 * Return or send a packet to the other party. 50 */ 51 void prvTCPReturnPacket( FreeRTOS_Socket_t * pxSocket, 52 NetworkBufferDescriptor_t * pxDescriptor, 53 uint32_t ulLen, 54 BaseType_t xReleaseAfterSend ); 55 56 /** 57 * Called by prvTCPReturnPacket(), this function will set the the window 58 * size on this side: 'xTCPHeader.usWindow'. 59 */ 60 void prvTCPReturn_CheckTCPWindow( FreeRTOS_Socket_t * pxSocket, 61 const NetworkBufferDescriptor_t * pxNetworkBuffer, 62 size_t uxIPHeaderSize ); 63 64 /* 65 * Called by prvTCPReturnPacket(), this function sets the sequence and ack numbers 66 * in the TCP-header. 67 */ 68 void prvTCPReturn_SetSequenceNumber( FreeRTOS_Socket_t * pxSocket, 69 const NetworkBufferDescriptor_t * pxNetworkBuffer, 70 size_t uxIPHeaderSize, 71 uint32_t ulLen ); 72 73 /* 74 * Return or send a packet to the other party. 75 */ 76 void prvTCPReturnPacket_IPV4( FreeRTOS_Socket_t * pxSocket, 77 NetworkBufferDescriptor_t * pxDescriptor, 78 uint32_t ulLen, 79 BaseType_t xReleaseAfterSend ); 80 81 /* 82 * Return or send a packet to the other party. 83 */ 84 void prvTCPReturnPacket_IPV6( FreeRTOS_Socket_t * pxSocket, 85 NetworkBufferDescriptor_t * pxDescriptor, 86 uint32_t ulLen, 87 BaseType_t xReleaseAfterSend ); 88 89 void prvTCPReturn_SetEndPoint( const FreeRTOS_Socket_t * pxSocket, 90 NetworkBufferDescriptor_t * pxNetworkBuffer, 91 size_t uxIPHeaderSize ); 92 93 /* 94 * Let ARP look-up the MAC-address of the peer and initialise the first SYN 95 * packet. 96 */ 97 BaseType_t prvTCPPrepareConnect_IPV4( FreeRTOS_Socket_t * pxSocket ); 98 99 /* 100 * Let ARP look-up the MAC-address of the peer and initialise the first SYN 101 * packet. 102 */ 103 BaseType_t prvTCPPrepareConnect_IPV6( FreeRTOS_Socket_t * pxSocket ); 104 105 /* 106 * Initialise the data structures which keep track of the TCP windowing system. 107 */ 108 void prvTCPCreateWindow( FreeRTOS_Socket_t * pxSocket ); 109 110 /* 111 * Set the initial properties in the options fields, like the preferred 112 * value of MSS and whether SACK allowed. Will be transmitted in the state 113 * 'eCONNECT_SYN'. 114 */ 115 UBaseType_t prvSetSynAckOptions( FreeRTOS_Socket_t * pxSocket, 116 TCPHeader_t * pxTCPHeader ); 117 118 /* 119 * Prepare an outgoing message, if anything has to be sent. 120 */ 121 int32_t prvTCPPrepareSend( FreeRTOS_Socket_t * pxSocket, 122 NetworkBufferDescriptor_t ** ppxNetworkBuffer, 123 UBaseType_t uxOptionsLength ); 124 125 /* 126 * The API FreeRTOS_send() adds data to the TX stream. Add 127 * this data to the windowing system to it can be transmitted. 128 */ 129 void prvTCPAddTxData( FreeRTOS_Socket_t * pxSocket ); 130 131 /* 132 * Set the TCP options (if any) for the outgoing packet. 133 */ 134 UBaseType_t prvSetOptions( FreeRTOS_Socket_t * pxSocket, 135 const NetworkBufferDescriptor_t * pxNetworkBuffer ); 136 137 /* 138 * Called from prvTCPHandleState(). There is data to be sent. 139 * If ipconfigUSE_TCP_WIN is defined, and if only an ACK must be sent, it will 140 * be checked if it would better be postponed for efficiency. 141 */ 142 BaseType_t prvSendData( FreeRTOS_Socket_t * pxSocket, 143 NetworkBufferDescriptor_t ** ppxNetworkBuffer, 144 uint32_t ulReceiveLength, 145 BaseType_t xByteCount ); 146 147 /* 148 * A "challenge ACK" is as per https://tools.ietf.org/html/rfc5961#section-3.2, 149 * case #3. In summary, an RST was received with a sequence number that is 150 * unexpected but still within the window. 151 */ 152 BaseType_t prvTCPSendChallengeAck( NetworkBufferDescriptor_t * pxNetworkBuffer ); 153 154 /* 155 * Reply to a peer with the RST flag on, in case a packet can not be handled. 156 */ 157 BaseType_t prvTCPSendReset( NetworkBufferDescriptor_t * pxNetworkBuffer ); 158 159 /* 160 * Check if the size of a network buffer is big enough to hold the outgoing message. 161 * Allocate a new bigger network buffer when necessary. 162 */ 163 NetworkBufferDescriptor_t * prvTCPBufferResize( const FreeRTOS_Socket_t * pxSocket, 164 NetworkBufferDescriptor_t * pxNetworkBuffer, 165 int32_t lDataLen, 166 UBaseType_t uxOptionsLength ); 167 /* *INDENT-OFF* */ 168 #ifdef __cplusplus 169 } /* extern "C" */ 170 #endif 171 /* *INDENT-ON* */ 172 173 #endif /* FREERTOS_TCP_TRANSMISSION_H */ 174
