#include <vetprot.h>
Inheritance diagram for cornelluniversity::vetserial::base_command:
Public Member Functions | |
| base_command (const cmnd_id cid) | |
| constructor The object must be initialized with a COMMAND_ID | |
| base_command (const uint8_ *in_pkt, uint32_ nbytes) | |
| This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Constructor overloaded for receiving packets rather than creating one. | |
| virtual | ~base_command (void) |
| Destructor; frees any dynamic memory that was used in during the objects life cycle (two internal buffers). | |
| const uint8_ * | packet (void) const |
| Internal packet buffer accessor. | |
| const int | packet_size (void) const |
| Accessor for the internall managed buffer byte count (i.e. | |
| const uint8_ | flags (void) const |
| Accessor to the packet flags byte (the full bit field). | |
| void | set_flag (const uint8_ f) |
| mutator for the packet flags byte; enables one or more flags by ORing in the supplied parameter into the current value. | |
| void | clr_flag (const flag_t f) |
| Toggles off a single bit in the flags bit field. | |
| bool | flag_enabled (const flag_t f) const |
| Determines if a single flag within the flags byte is enabled or not. | |
| void | error_code (const err_code id) |
| mutator for the packet error code byte; Sets the byte to a supplied ERROR_CODE defined value. | |
| const err_code | error_code (void) const |
| accessor to the packet error code byte. | |
| void | data_id (const uint8_ id) |
| mutator for the internally stored data-id field. | |
| const unsigned char | data_id (void) const |
| accessor to the internally stored data-id field. | |
| void | payload_size (const uint16_ sz) |
| mutator for the internally stored payload size field. | |
| const uint16_ | payload_size (void) const |
| accessor of the internally stored payload size field. | |
| virtual void | execute (void)=0 |
| pure virtual function that must be over-ridden in all objects inheriting from base_command. | |
Static Public Attributes | |
| static const unsigned int | PKT_HEADER_SZ |
| static const unsigned int | PKT_TAIL_SZ |
| static const unsigned int | PKT_MAX_SZ |
Protected Member Functions | |
| uint16_ | crc16 (const uint8_ *indata, const uint32_ nbytes) |
| generates the CCITT CRC 16 polynomial X^16 + X^12 + X^5 + 1 | |
| bool | verify_crc16 (const uint8_ *full_packet, const uint32_ nbytes) |
| validates the accuracy of a supplied packet against its included CRC(s) pass the FULL packet, the routine will determine what validations to perform. | |
| void | header (void) |
| When called, this will reinitialize the internal buffers, essentially wiping out any previous data. | |
| void | tail (const uint8_ *payload, const uint32_ payload_sz=0) |
| Appends a protocol defined trailer to the end of the packet currently in the interal buffer. | |
Protected Attributes | |
| uint8_ * | buffer_ |
| uint8_ * | packet_ |
| uint32_ | buffersz_ |
| uint32_ | pktsz_ |
This handles packet management, dissecting incoming packets or creating new ones as needed. How the packets are assembled is determined in the pure virtual function execute() which must be over-ridden by any class inheriting from base_command.
Definition at line 134 of file vetprot.h.
| cornelluniversity::vetserial::base_command::base_command | ( | const cmnd_id | cid | ) |
constructor The object must be initialized with a COMMAND_ID
| cid | - the COMMAND_ID defined command being initialized |
This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Constructor overloaded for receiving packets rather than creating one.
| in_pkt | - pointer to a unisigned char array that comprises an in-coming protocol conforming packet | |
| nbytes | - the size of the packet in bytes |
| cornelluniversity::vetexcept | data out-of-bounds | |
| cornelluniversity::vetexcept | NULLPTR encountered where data is required | |
| std::bad_alloc | standard memory allocation failure |
| void cornelluniversity::vetserial::base_command::clr_flag | ( | const flag_t | f | ) | [inline] |
| uint16_ cornelluniversity::vetserial::base_command::crc16 | ( | const uint8_ * | indata, | |
| const uint32_ | nbytes | |||
| ) | [protected] |
generates the CCITT CRC 16 polynomial X^16 + X^12 + X^5 + 1
| indata | - pointer to an unsigned char based c-style string | |
| nbytes | - int size of the indata array |
| cornelluniversity::vetexcept | NULLPTR encountered where data is required |
| const unsigned char cornelluniversity::vetserial::base_command::data_id | ( | void | ) | const [inline] |
accessor to the internally stored data-id field.
| void cornelluniversity::vetserial::base_command::data_id | ( | const uint8_ | id | ) | [inline] |
mutator for the internally stored data-id field.
This fields value is arbitrary and supplied to support debugging and more advanced packet tracking schemes. The value of the Id is limited to 8-bit values.
| id | - 8 bit integer to be stored in the packet |
| const err_code cornelluniversity::vetserial::base_command::error_code | ( | void | ) | const [inline] |
| void cornelluniversity::vetserial::base_command::error_code | ( | const err_code | id | ) | [inline] |
mutator for the packet error code byte; Sets the byte to a supplied ERROR_CODE defined value.
| id | - ERROR_CODE defined error id |
| virtual void cornelluniversity::vetserial::base_command::execute | ( | void | ) | [pure virtual] |
pure virtual function that must be over-ridden in all objects inheriting from base_command.
This function should be developed to implement the assembly (or dissection if necessary) of packets for the command in question. The end result should be to have a fully formed packet in buffer_ (for outgoing) or for an incoming packet parsed into its appropriate members.
Implemented in cornelluniversity::vetserial::control_request, cornelluniversity::vetserial::status_request, cornelluniversity::vetserial::status_response, cornelluniversity::vetserial::mp3_play_request, and cornelluniversity::vetserial::mp3_stop_request.
| bool cornelluniversity::vetserial::base_command::flag_enabled | ( | const flag_t | f | ) | const [inline] |
| const uint8_ cornelluniversity::vetserial::base_command::flags | ( | void | ) | const [inline] |
| void cornelluniversity::vetserial::base_command::header | ( | void | ) | [protected] |
When called, this will reinitialize the internal buffers, essentially wiping out any previous data.
The 10-byte packet header is then rebuilt based on the current values stored in the objects private members. The header is left in the buffer for you to use or append additional data.
| cornelluniversity::vetexcept | data out-of-bounds | |
| std::bad_alloc | standard memory allocation failure |
| const uint8_* cornelluniversity::vetserial::base_command::packet | ( | void | ) | const [inline] |
| const int cornelluniversity::vetserial::base_command::packet_size | ( | void | ) | const [inline] |
| const uint16_ cornelluniversity::vetserial::base_command::payload_size | ( | void | ) | const [inline] |
| void cornelluniversity::vetserial::base_command::payload_size | ( | const uint16_ | sz | ) | [inline] |
| void cornelluniversity::vetserial::base_command::set_flag | ( | const uint8_ | f | ) | [inline] |
| void cornelluniversity::vetserial::base_command::tail | ( | const uint8_ * | payload, | |
| const uint32_ | payload_sz = 0 | |||
| ) | [protected] |
Appends a protocol defined trailer to the end of the packet currently in the interal buffer.
This routine does not question the contents of the buffer, it simply appends three additional bytes. Two of those bytes are the CRC checksum for the data payload, so you'll have to pass those (payload) bytes into this routine.
| payload | - pointer to an unsigned char based c-style string that comprises the data payload (and oly the payload, no part of the header should be included) | |
| payload_sz | - (optional) int size of the payload array. Because this value is stored internally for header purposes, you can ignore the second argument and the value in the appropriate private member will be used instead. |
| cornelluniversity::vetexcept | data out-of-bounds | |
| cornelluniversity::vetexcept | NULLPTR encountered where data is required |
| bool cornelluniversity::vetserial::base_command::verify_crc16 | ( | const uint8_ * | full_packet, | |
| const uint32_ | nbytes | |||
| ) | [protected] |
validates the accuracy of a supplied packet against its included CRC(s) pass the FULL packet, the routine will determine what validations to perform.
In the case of just a header being present, this routine will return after that check. If the packet also has a data payload, the this routine will return only after validating both CRCs. Both must be valid for the routine to return true.
| indata | - pointer to an unsigned char based c-style string | |
| nbytes | - int size of the indata array |
| cornelluniversity::vetexcept | data out-of-bounds | |
| cornelluniversity::vetexcept | NULLPTR encountered where data is required | |
| std::bad_alloc | standard memory allocation failure |
const unsigned int cornelluniversity::vetserial::base_command::PKT_HEADER_SZ [static] |
const unsigned int cornelluniversity::vetserial::base_command::PKT_MAX_SZ [static] |
const unsigned int cornelluniversity::vetserial::base_command::PKT_TAIL_SZ [static] |
1.4.7