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Fix nasa#111, make dispatch tables and functions consistent
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Standardize the dynamic handler functions to two basic types,
one that accepts a PDU (recv) and one that does not (send).

Also create several dispatch table types, one based on
file directive code, one based on Tx sub state, and one based
on Rx sub state.

Change the dispatcher functions to use these common types
and create new dispatcher functions where there was not
a separate function already (this makes the pattern consistent).

Make all "receive" helper functions accept a pointer to the
recieved PDU and actually use that pointer to read the data.  This
substantially reduces reliance on the global and fixes some
cases where a pointer was actually passed into a function, but
ignored.  This takes a significant step toward removing the
global entirely, but does not do so yet.
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@jphickey
jphickey committed Dec 17, 2021
1 parent a894069 commit 132addc
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Showing 14 changed files with 723 additions and 552 deletions.
189 changes: 110 additions & 79 deletions fsw/src/cf_cfdp.c
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88 changes: 74 additions & 14 deletions fsw/src/cf_cfdp.h
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Original file line number Diff line number Diff line change
Expand Up @@ -335,6 +335,67 @@ typedef struct CF_Engine
uint8 enabled;
} CF_Engine_t;

/**
* @brief A function for dispatching actions to a handler, without existing PDU data
*
* This allows quick delegation to handler functions using dispatch tables. This version is
* used on the transmit side, where a PDU will likely be generated/sent by the handler being
* invoked.
*
* @param[inout] t The transaction object
*/
typedef void (*CF_CFDP_StateSendFunc_t)(CF_Transaction_t *t);

/**
* @brief A function for dispatching actions to a handler, with existing PDU data
*
* This allows quick delegation of PDUs to handler functions using dispatch tables. This version is
* used on the receive side where a PDU buffer is associated with the activity, which is then
* interpreted by the handler being invoked.
*
* @param[inout] t The transaction object
* @param[inout] ph The PDU buffer currently being received/processed
*/
typedef void (*CF_CFDP_StateRecvFunc_t)(CF_Transaction_t *t, CF_CFDP_PduHeader_t *ph);

/**
* @brief A table of receive handler functions based on file directive code
*
* For PDUs identified as a "file directive" type - generally anything other
* than file data - this provides a table to branch to a different handler
* function depending on the value of the file directive code.
*/
typedef struct
{
/* a separate recv handler for each possible file directive PDU in this state */
CF_CFDP_StateRecvFunc_t fdirective[CF_CFDP_FileDirective_INVALID_MAX];
} CF_CFDP_FileDirectiveDispatchTable_t;

/**
* @brief A table of transmit handler functions based on transaction state
*
* This reflects the main dispatch table for the transmit side of a transaction.
* Each possible state has a corresponding function pointer in the table to implement
* the PDU transmit action(s) associated with that state.
*/
typedef struct
{
CF_CFDP_StateSendFunc_t tx[CF_TxnState_INVALID];
} CF_CFDP_TxnSendDispatchTable_t;

/**
* @brief A table of receive handler functions based on transaction state
*
* This reflects the main dispatch table for the receive side of a transaction.
* Each possible state has a corresponding function pointer in the table to implement
* the PDU receive action(s) associated with that state.
*/
typedef struct
{
/* a separate recv handler for each possible file directive PDU in this state */
CF_CFDP_StateRecvFunc_t rx[CF_TxnState_INVALID];
} CF_CFDP_TxnRecvDispatchTable_t;

/* NOTE: functions grouped together on contiguous lines are in groups that are described by
* a simple comment at the top. Other comments below that apply to the whole group. */
/* reset functions */
Expand All @@ -360,9 +421,8 @@ extern CF_CFDP_PduHeader_t *CF_CFDP_ConstructPduHeader(const CF_Transaction_t *t
CF_EntityId_t src_eid, CF_EntityId_t dst_eid,
uint8 towards_sender, CF_TransactionSeq_t tsn, int silent);
extern CF_SendRet_t CF_CFDP_SendMd(CF_Transaction_t *t);
extern CF_SendRet_t CF_CFDP_SendFd(CF_Transaction_t *t, uint32 offset, int len);

extern CF_SendRet_t CF_CFDP_SendEof(CF_Transaction_t *t);
extern CF_SendRet_t CF_CFDP_SendFd(CF_Transaction_t *t, CF_CFDP_PduHeader_t *ph, uint32 offset, int len);
extern CF_SendRet_t CF_CFDP_SendEof(CF_Transaction_t *t);
/* NOTE: CF_CFDP_SendAck() takes a CF_TransactionSeq_t instead of getting it from transaction history because
* of the special case where a FIN-ACK must be sent for an unknown transaction. It's better for
* long term maintenance to not build an incomplete CF_History_t for it.
Expand All @@ -371,22 +431,22 @@ extern CF_SendRet_t CF_CFDP_SendAck(CF_Transaction_t *t, CF_CFDP_AckTxnStatus_t
CF_CFDP_ConditionCode_t cc, CF_EntityId_t peer_eid, CF_TransactionSeq_t tsn);
extern CF_SendRet_t CF_CFDP_SendFin(CF_Transaction_t *t, CF_CFDP_FinDeliveryCode_t dc, CF_CFDP_FinFileStatus_t fs,
CF_CFDP_ConditionCode_t cc);
extern CF_SendRet_t CF_CFDP_SendNak(CF_Transaction_t *t, int num_segment_requests);
extern CF_SendRet_t CF_CFDP_SendNak(CF_Transaction_t *t, CF_CFDP_PduHeader_t *ph, int num_segment_requests);

/* PDU receive functions */
/* returns 0 on success */
extern int CF_CFDP_RecvMd(CF_Transaction_t *t);
extern int CF_CFDP_RecvFd(CF_Transaction_t *t);
extern int CF_CFDP_RecvEof(void);
extern int CF_CFDP_RecvAck(void);
extern int CF_CFDP_RecvFin(void);
extern int CF_CFDP_RecvNak(int *num_segment_requests);
extern int CF_CFDP_RecvMd(CF_Transaction_t *t, CF_CFDP_PduHeader_t *ph);
extern int CF_CFDP_RecvFd(CF_Transaction_t *t, CF_CFDP_PduHeader_t *ph);
extern int CF_CFDP_RecvEof(CF_Transaction_t *t, CF_CFDP_PduHeader_t *ph);
extern int CF_CFDP_RecvAck(CF_Transaction_t *t, CF_CFDP_PduHeader_t *ph);
extern int CF_CFDP_RecvFin(CF_Transaction_t *t, CF_CFDP_PduHeader_t *ph);
extern int CF_CFDP_RecvNak(CF_Transaction_t *t, CF_CFDP_PduHeader_t *ph, int *num_segment_requests);

/* Engine functional dispatch. These are all implemented in cf_cfdp_r.c or cf_cfdp_s.c */
extern void CF_CFDP_S1_Recv(CF_Transaction_t *t);
extern void CF_CFDP_R1_Recv(CF_Transaction_t *t);
extern void CF_CFDP_S2_Recv(CF_Transaction_t *t);
extern void CF_CFDP_R2_Recv(CF_Transaction_t *t);
extern void CF_CFDP_S1_Recv(CF_Transaction_t *t, CF_CFDP_PduHeader_t *ph);
extern void CF_CFDP_R1_Recv(CF_Transaction_t *t, CF_CFDP_PduHeader_t *ph);
extern void CF_CFDP_S2_Recv(CF_Transaction_t *t, CF_CFDP_PduHeader_t *ph);
extern void CF_CFDP_R2_Recv(CF_Transaction_t *t, CF_CFDP_PduHeader_t *ph);
extern void CF_CFDP_S1_Tx(CF_Transaction_t *t);
extern void CF_CFDP_S2_Tx(CF_Transaction_t *t);
extern void CF_CFDP_R_Tick(CF_Transaction_t *t, int *cont);
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25 changes: 12 additions & 13 deletions fsw/src/cf_cfdp_helpers.c
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Original file line number Diff line number Diff line change
Expand Up @@ -134,13 +134,12 @@ static int CF_GetEIDSize(const CF_CFDP_PduHeader_t *ph)

/* get the variable length header items out of the PDU header and store as incoming data */
/* in.msg must be valid PDU message */
int CF_GetVariableHeader(void)
int CF_GetVariableHeader(CF_CFDP_PduHeader_t *ph)
{
CF_CFDP_PduHeader_t *ph = &((CF_PduRecvMsg_t *)CF_AppData.engine.in.msg)->ph;
const int eid_l = CF_GetEIDSize(ph);
const int tsn_l = CF_GetTSNSize(ph);
int offs = sizeof(*ph);
int ret = -1;
const int eid_l = CF_GetEIDSize(ph);
const int tsn_l = CF_GetTSNSize(ph);
int offs = sizeof(*ph);
int ret = -1;

if ((eid_l > 0) && (tsn_l > 0))
{
Expand All @@ -155,14 +154,14 @@ int CF_GetVariableHeader(void)
return ret;
}

void CF_SetVariableHeader(CF_EntityId_t src_eid, CF_EntityId_t dst_eid, CF_TransactionSeq_t tsn)
void CF_SetVariableHeader(CF_CFDP_PduHeader_t *ph, CF_EntityId_t src_eid, CF_EntityId_t dst_eid,
CF_TransactionSeq_t tsn)
{
CF_CFDP_PduHeader_t *ph = &((CF_PduSendMsg_t *)CF_AppData.engine.out.msg)->ph;
int offs = sizeof(*ph);
const int eid_s_l = CF_GetMemcpySize((uint8 *)&src_eid, sizeof(src_eid));
const int eid_d_l = CF_GetMemcpySize((uint8 *)&dst_eid, sizeof(dst_eid));
const int tsn_l = CF_GetMemcpySize((uint8 *)&tsn, sizeof(tsn));
const int csize = ((eid_s_l > eid_d_l) ? eid_s_l : eid_d_l);
int offs = sizeof(*ph);
const int eid_s_l = CF_GetMemcpySize((uint8 *)&src_eid, sizeof(src_eid));
const int eid_d_l = CF_GetMemcpySize((uint8 *)&dst_eid, sizeof(dst_eid));
const int tsn_l = CF_GetMemcpySize((uint8 *)&tsn, sizeof(tsn));
const int csize = ((eid_s_l > eid_d_l) ? eid_s_l : eid_d_l);

CF_MemcpyToBE(((uint8 *)ph) + offs, (uint8 *)&src_eid, sizeof(src_eid), csize);
offs += csize;
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5 changes: 3 additions & 2 deletions fsw/src/cf_cfdp_pdu.h
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Original file line number Diff line number Diff line change
Expand Up @@ -106,8 +106,9 @@ DECLARE_FIELD(CF_CFDP_PduHeader_LENGTHS_TRANSACTION_SEQUENCE, 3, 0)

extern int CF_GetMemcpySize(const uint8 *num, int size);
extern void CF_MemcpyToBE(uint8 *dst, const uint8 *src, int src_size, int dst_size);
extern int CF_GetVariableHeader(void);
extern void CF_SetVariableHeader(CF_EntityId_t src_eid, CF_EntityId_t dst_eid, CF_TransactionSeq_t tsn);
extern int CF_GetVariableHeader(CF_CFDP_PduHeader_t *ph);
extern void CF_SetVariableHeader(CF_CFDP_PduHeader_t *ph, CF_EntityId_t src_eid, CF_EntityId_t dst_eid,
CF_TransactionSeq_t tsn);
extern int CF_HeaderSize(const CF_CFDP_PduHeader_t *ph);

#define CF_MAX_HEADER_SIZE (sizeof(CF_CFDP_PduHeader_t) + (2 * sizeof(CF_EntityId_t)) + sizeof(CF_TransactionSeq_t))
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