1 /* 2 * Copyright (C) 2014 BlueKitchen GmbH 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 4. Any redistribution, use, or modification is done solely for 17 * personal benefit and not for any commercial purpose or for 18 * monetary gain. 19 * 20 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 24 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * Please inquire about commercial licensing options at 34 * [email protected] 35 * 36 */ 37 38 #define BTSTACK_FILE__ "l2cap_signaling.c" 39 40 /* 41 * l2cap_signaling.h 42 */ 43 44 #include "l2cap_signaling.h" 45 #include "btstack_config.h" 46 #include "btstack_debug.h" 47 #include "hci.h" 48 49 #include <string.h> 50 51 uint16_t l2cap_create_signaling_packet(uint8_t * acl_buffer, hci_con_handle_t handle, uint8_t pb_flags, uint16_t cid, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, va_list argptr){ 52 53 static const char *l2cap_signaling_commands_format[] = { 54 "2D", // 0x01 command reject: reason {cmd not understood (0), sig MTU exceeded (2:max sig MTU), invalid CID (4:req CID)}, data len, data 55 "22", // 0x02 connection request: psm, source cid 56 "2222", // 0x03 connection response: destination cid, source cid, result, status 57 "22D", // 0x04 config request: destination cid, flags, configuration options 58 "222D", // 0x05 config response: source cid, flags, result, configuration options 59 "22", // 0x06 disconnection request: destination cid, source cid 60 "22", // 0x07 disconnection response: destination cid, source CID 61 "D", // 0x08 echo request: data 62 "D", // 0x09 echo response: data 63 "2", // 0x0a information request: info type {1=Connectionless MTU, 2=Extended features supported} 64 "22D", // 0x0b information response: info type, Result, Data 65 NULL, // 0x0c non-supported AMP command 66 NULL, // 0x0d non-supported AMP command 67 NULL, // 0x0e non-supported AMP command 68 NULL, // 0x0f non-supported AMP command 69 NULL, // 0x10 non-supported AMP command 70 NULL, // 0x11 non-supported AMP command 71 "2222", // 0x12 connection parameter update request: interval min, interval max, slave latency, timeout multiplier 72 "2", // 0x13 connection parameter update response: result 73 "22222", // 0X14 le credit-based connection request: simplified psm, source cid, mtu, mps, initial credits 74 "22222", // 0x15 le credit-based connection response: dest cid, mtu, mps, initial credits, result 75 "22", // 0x16 le flow control credit indication: source cid, credits 76 "2222C", // 0x17 l2cap credit-based connection request: simplified psm, mtu, mps, initial credits, source cid[0] 77 "2222C", // 0x18 l2cap credit-based connection request: mtu, mps, initial credits, result, destinations cid[0] 78 "22C", // 0x19 l2cap credit-based reconfigure request: mu, mps, destination cid[0] 79 "2", // 0x1a l2cap credit-based reconfigure response: result 80 #ifdef UNIT_TEST 81 "M", // invalid format for unit testing 82 #endif 83 }; 84 static const unsigned int num_l2cap_commands = sizeof(l2cap_signaling_commands_format) / sizeof(const char *); 85 86 btstack_assert(0 < cmd); 87 btstack_assert(cmd <= num_l2cap_commands); 88 89 const char *format = l2cap_signaling_commands_format[cmd-1u]; 90 btstack_assert(format != NULL); 91 92 // 0 - Connection handle : PB=pb : BC=00 93 little_endian_store_16(acl_buffer, 0u, handle | (pb_flags << 12u) | (0u << 14u)); 94 // 6 - L2CAP channel = 1 95 little_endian_store_16(acl_buffer, 6, cid); 96 // 8 - Code 97 acl_buffer[8] = cmd; 98 // 9 - id (!= 0 sequentially) 99 acl_buffer[9] = identifier; 100 101 // 12 - L2CAP signaling parameters 102 uint16_t pos = 12; 103 uint16_t word; 104 uint8_t * ptr_u8; 105 uint16_t * ptr_u16; 106 while (*format) { 107 switch(*format) { 108 case '2': // 16 bit value 109 word = va_arg(argptr, int); // LCOV_EXCL_BR_LINE 110 // minimal va_arg is int: 2 bytes on 8+16 bit CPUs 111 acl_buffer[pos++] = word & 0xffu; 112 acl_buffer[pos++] = word >> 8; 113 break; 114 case 'C': // list of cids != zero, last one is zero 115 ptr_u16 = va_arg(argptr, uint16_t *); // LCOV_EXCL_BR_LINE 116 while (*ptr_u16 != 0){ 117 little_endian_store_16(acl_buffer, pos, *ptr_u16); 118 ptr_u16++; 119 pos += 2; 120 } 121 break; 122 case 'D': // variable data. passed: len, ptr 123 word = va_arg(argptr, int); // LCOV_EXCL_BR_LINE 124 ptr_u8 = va_arg(argptr, uint8_t *); // LCOV_EXCL_BR_LINE 125 (void)memcpy(&acl_buffer[pos], ptr_u8, word); 126 pos += word; 127 break; 128 default: 129 btstack_unreachable(); 130 break; 131 } 132 format++; 133 }; 134 va_end(argptr); 135 136 // Fill in various length fields: it's the number of bytes following for ACL length and l2cap parameter length 137 // - the l2cap payload length is counted after the following channel id (only payload) 138 139 // 2 - ACL length 140 little_endian_store_16(acl_buffer, 2u, pos - 4u); 141 // 4 - L2CAP packet length 142 little_endian_store_16(acl_buffer, 4u, pos - 6u - 2u); 143 // 10 - L2CAP signaling parameter length 144 little_endian_store_16(acl_buffer, 10u, pos - 12u); 145 146 return pos; 147 } 148