1 /* 2 * Copyright (C) 2009 by Matthias Ringwald 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 * 17 * THIS SOFTWARE IS PROVIDED BY MATTHIAS RINGWALD AND CONTRIBUTORS 18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 20 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 21 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 23 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 24 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 25 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 26 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 27 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 */ 31 32 /* 33 * l2cap_signaling.h 34 * 35 * Created by Matthias Ringwald on 7/23/09. 36 */ 37 38 #include "l2cap_signaling.h" 39 40 #include <string.h> 41 42 static char *l2cap_signaling_commands_format[] = { 43 "D", // 0x01 command reject: reason {cmd not understood (0), sig MTU exceeded (2:max sig MTU), invalid CID (4:req CID)}, data len, data 44 "22", // 0x02 connection request: PSM, Source CID 45 "2222", // 0x03 connection response: Dest CID, Source CID, Result, Status 46 "22D", // 0x04 config request: Dest CID, Flags, Configuration options 47 "222D", // 0x05 config response: Source CID, Flags, Result, Configuration options 48 "22", // 0x06 disconection request: Dest CID, Source CID 49 "22", // 0x07 disconection response: Dest CID, Source CID 50 "D", // 0x08 echo request: Data 51 "D", // 0x09 echo response: Data 52 "2", // 0x0a information request: InfoType {1=Connectionless MTU, 2=Extended features supported} 53 "22D", // 0x0b information response: InfoType, Result, Data 54 }; 55 56 uint8_t sig_seq_nr = 0xff; 57 uint16_t source_cid = 0x40; 58 59 uint8_t l2cap_next_sig_id(void){ 60 if (sig_seq_nr == 0xff) { 61 sig_seq_nr = 1; 62 } else { 63 sig_seq_nr++; 64 } 65 return sig_seq_nr; 66 } 67 68 uint16_t l2cap_next_local_cid(void){ 69 return source_cid++; 70 } 71 72 uint16_t l2cap_create_signaling_internal(uint8_t * acl_buffer, hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, va_list argptr){ 73 74 // 0 - Connection handle : PB=10 : BC=00 75 bt_store_16(acl_buffer, 0, handle | (2 << 12) | (0 << 14)); 76 // 6 - L2CAP channel = 1 77 bt_store_16(acl_buffer, 6, 1); 78 // 8 - Code 79 acl_buffer[8] = cmd; 80 // 9 - id (!= 0 sequentially) 81 acl_buffer[9] = identifier; 82 83 // 12 - L2CAP signaling parameters 84 uint16_t pos = 12; 85 const char *format = l2cap_signaling_commands_format[cmd-1]; 86 uint16_t word; 87 uint8_t * ptr; 88 while (*format) { 89 switch(*format) { 90 case '1': // 8 bit value 91 case '2': // 16 bit value 92 word = va_arg(argptr, int); 93 // minimal va_arg is int: 2 bytes on 8+16 bit CPUs 94 acl_buffer[pos++] = word & 0xff; 95 if (*format == '2') { 96 acl_buffer[pos++] = word >> 8; 97 } 98 break; 99 case 'D': // variable data. passed: len, ptr 100 word = va_arg(argptr, int); 101 ptr = va_arg(argptr, uint8_t *); 102 memcpy(&acl_buffer[pos], ptr, word); 103 pos += word; 104 break; 105 default: 106 break; 107 } 108 format++; 109 }; 110 va_end(argptr); 111 112 // Fill in various length fields: it's the number of bytes following for ACL lenght and l2cap parameter length 113 // - the l2cap payload length is counted after the following channel id (only payload) 114 115 // 2 - ACL length 116 bt_store_16(acl_buffer, 2, pos - 4); 117 // 4 - L2CAP packet length 118 bt_store_16(acl_buffer, 4, pos - 6 - 2); 119 // 10 - L2CAP signaling parameter length 120 bt_store_16(acl_buffer, 10, pos - 12); 121 122 return pos; 123 } 124