1 /* 2 * l2cap_signaling.h 3 * 4 * Created by Matthias Ringwald on 7/23/09. 5 */ 6 7 #include "l2cap_signaling.h" 8 9 #include <stdarg.h> 10 11 static char *l2cap_signaling_commands_format[] = { 12 "D", // 0x01 command reject: reason {cmd not understood (0), sig MTU exceeded (2:max sig MTU), invalid CID (4:req CID)}, data len, data 13 "22", // 0x02 connection request: PSM, Source CID 14 "2222", // 0x03 connection response: Dest CID, Source CID, Result, Status 15 "22D", // 0x04 config request: Dest CID, Flags, Configuration options 16 "222D", // 0x05 config response: Source CID, Flags, Result, Configuration options 17 "22", // 0x06 disconection request: Dest CID, Source CID 18 "22", // 0x07 disconection response: Dest CID, Source CID 19 "D", // 0x08 echo request: Data 20 "D", // 0x09 echo response: Data 21 "2", // 0x0a information request: InfoType {1=Connectionless MTU, 2=Extended features supported} 22 "22D", // 0x0b information response: InfoType, Result, Data 23 }; 24 25 uint8_t sig_seq_nr = 1; 26 uint16_t local_cid = 0x40; 27 28 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){ 29 30 // 0 - Connection handle : PB=10 : BC=00 31 bt_store_16(acl_buffer, 0, handle | (2 << 12) | (0 << 14)); 32 // 6 - L2CAP channel = 1 33 bt_store_16(acl_buffer, 6, 1); 34 // 8 - Code 35 acl_buffer[8] = cmd; 36 // 9 - id (!= 0 sequentially) 37 acl_buffer[9] = identifier; 38 39 // 12 - L2CAP signaling parameters 40 uint16_t pos = 12; 41 const char *format = l2cap_signaling_commands_format[cmd-1]; 42 uint16_t word; 43 uint8_t * ptr; 44 while (*format) { 45 switch(*format) { 46 case '1': // 8 bit value 47 case '2': // 16 bit value 48 word = va_arg(argptr, int); 49 // minimal va_arg is int: 2 bytes on 8+16 bit CPUs 50 acl_buffer[pos++] = word & 0xff; 51 if (*format == '2') { 52 acl_buffer[pos++] = word >> 8; 53 } 54 break; 55 case 'D': // variable data. passed: len, ptr 56 word = va_arg(argptr, int); 57 ptr = va_arg(argptr, uint8_t *); 58 memcpy(&acl_buffer[pos], ptr, word); 59 pos += word; 60 break; 61 default: 62 break; 63 } 64 format++; 65 }; 66 va_end(argptr); 67 68 // Fill in various length fields: it's the number of bytes following for ACL lenght and l2cap parameter length 69 // - the l2cap payload length is counted after the following channel id (only payload) 70 71 // 2 - ACL length 72 bt_store_16(acl_buffer, 2, pos - 4); 73 // 4 - L2CAP packet length 74 bt_store_16(acl_buffer, 4, pos - 6 - 2); 75 // 10 - L2CAP signaling parameter length 76 bt_store_16(acl_buffer, 10, pos - 12); 77 78 return pos; 79 } 80