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working on #3641: more on /refund implementation

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This commit is contained in:
Christian Grothoff 2016-05-05 22:57:55 +02:00
parent 07d9978fb9
commit 0c959e75d1
8 changed files with 512 additions and 7 deletions
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280
src/exchange/taler-exchange-httpd_db.c
View File

@ -105,12 +105,16 @@ calculate_transaction_list_totals (struct TALER_EXCHANGEDB_TransactionList *tl,
{
struct TALER_Amount spent = *off;
struct TALER_EXCHANGEDB_TransactionList *pos;
struct TALER_Amount refunded;
TALER_amount_get_zero (spent.currency,
&refunded);
for (pos = tl; NULL != pos; pos = pos->next)
{
switch (pos->type)
{
case TALER_EXCHANGEDB_TT_DEPOSIT:
/* spent += pos->amount_with_fee */
if (GNUNET_OK !=
TALER_amount_add (&spent,
&spent,
@ -121,6 +125,7 @@ calculate_transaction_list_totals (struct TALER_EXCHANGEDB_TransactionList *tl,
}
break;
case TALER_EXCHANGEDB_TT_REFRESH_MELT:
/* spent += pos->amount_with_fee */
if (GNUNET_OK !=
TALER_amount_add (&spent,
&spent,
@ -130,8 +135,37 @@ calculate_transaction_list_totals (struct TALER_EXCHANGEDB_TransactionList *tl,
return GNUNET_SYSERR;
}
break;
case TALER_EXCHANGEDB_TT_REFUND:
/* refunded += pos->refund_amount - pos->refund_fee */
if (GNUNET_OK !=
TALER_amount_add (&refunded,
&refunded,
&pos->details.refund->refund_amount))
{
GNUNET_break (0);
return GNUNET_SYSERR;
}
if (GNUNET_OK !=
TALER_amount_subtract (&refunded,
&refunded,
&pos->details.refund->refund_fee))
{
GNUNET_break (0);
return GNUNET_SYSERR;
}
break;
}
}
/* spent = spent - refunded */
if (GNUNET_OK !=
TALER_amount_subtract (&spent,
&spent,
&refunded))
{
GNUNET_break (0);
return GNUNET_SYSERR;
}
*ret = spent;
return GNUNET_OK;
}
@ -261,6 +295,252 @@ TMH_DB_execute_deposit (struct MHD_Connection *connection,
}
/**
* Execute a "/refund". Returns a confirmation that the refund
* was successful, or a failure if we are not aware of a matching
* /deposit or if it is too late to do the refund.
*
* @param connection the MHD connection to handle
* @param refund refund details
* @return MHD result code
*/
int
TMH_DB_execute_refund (struct MHD_Connection *connection,
const struct TALER_EXCHANGEDB_Refund *refund)
{
struct TALER_EXCHANGEDB_Session *session;
struct TALER_EXCHANGEDB_TransactionList *tl;
struct TALER_EXCHANGEDB_TransactionList *tlp;
const struct TALER_EXCHANGEDB_Deposit *dep;
const struct TALER_EXCHANGEDB_Refund *ref;
struct TMH_KS_StateHandle *mks;
struct TALER_EXCHANGEDB_DenominationKeyIssueInformation *dki;
struct TALER_Amount expect_fee;
int ret;
int deposit_found;
int refund_found;
int done;
int fee_cmp;
if (NULL == (session = TMH_plugin->get_session (TMH_plugin->cls)))
{
GNUNET_break (0);
return TMH_RESPONSE_reply_internal_db_error (connection);
}
dep = NULL;
ref = NULL;
START_TRANSACTION (session, connection);
tl = TMH_plugin->get_coin_transactions (TMH_plugin->cls,
session,
&refund->coin.coin_pub);
if (NULL == tl)
{
TMH_plugin->rollback (TMH_plugin->cls,
session);
return TMH_RESPONSE_reply_refund_failure (connection,
MHD_HTTP_NOT_FOUND);
}
deposit_found = GNUNET_NO;
for (tlp = tl; NULL != tlp; tlp = tlp->next)
{
switch (tlp->type)
{
case TALER_EXCHANGEDB_TT_DEPOSIT:
{
dep = tlp->details.deposit;
if ( (0 == memcmp (&dep->merchant_pub,
&refund->merchant_pub,
sizeof (struct TALER_MerchantPublicKeyP))) &&
(0 == memcmp (&dep->h_contract,
&refund->h_contract,
sizeof (struct GNUNET_HashCode))) &&
(dep->transaction_id == refund->transaction_id) )
{
deposit_found = GNUNET_YES;
break;
}
}
break;
case TALER_EXCHANGEDB_TT_REFRESH_MELT:
/* Melts cannot be refunded, ignore here */
break;
case TALER_EXCHANGEDB_TT_REFUND:
{
ref = tlp->details.refund;
/* First, check if existing refund request is identical */
if ( (0 == memcmp (&ref->merchant_pub,
&refund->merchant_pub,
sizeof (struct TALER_MerchantPublicKeyP))) &&
(0 == memcmp (&ref->h_contract,
&refund->h_contract,
sizeof (struct GNUNET_HashCode))) &&
(ref->transaction_id == refund->transaction_id) &&
(ref->rtransaction_id == refund->rtransaction_id) )
{
refund_found = GNUNET_YES;
break;
}
/* Second, check if existing refund request conflicts */
if ( (0 == memcmp (&ref->merchant_pub,
&refund->merchant_pub,
sizeof (struct TALER_MerchantPublicKeyP))) &&
(0 == memcmp (&ref->h_contract,
&refund->h_contract,
sizeof (struct GNUNET_HashCode))) &&
(ref->transaction_id == refund->transaction_id) &&
(ref->rtransaction_id != refund->rtransaction_id) )
{
GNUNET_break_op (0); /* conflicting refound found */
refund_found = GNUNET_SYSERR;
/* NOTE: Alternatively we could total up all existing
refunds and check if the sum still permits the
refund requested (thus allowing multiple, partial
refunds). Fow now, we keep it simple. */
break;
}
}
break;
}
}
/* handle if deposit was NOT found */
if (GNUNET_NO == deposit_found)
{
TMH_plugin->rollback (TMH_plugin->cls,
session);
TMH_plugin->free_coin_transaction_list (TMH_plugin->cls,
tl);
return TMH_RESPONSE_reply_deposit_unknown (connection);
}
/* handle if conflicting refund found */
if (GNUNET_SYSERR == refund_found)
{
TMH_plugin->rollback (TMH_plugin->cls,
session);
ret = TMH_RESPONSE_reply_refund_conflict (connection,
tl);
TMH_plugin->free_coin_transaction_list (TMH_plugin->cls,
tl);
return ret;
}
/* handle if identical refund found */
if (GNUNET_YES == refund_found)
{
/* /refund already done, simply re-transmit confirmation */
TMH_plugin->rollback (TMH_plugin->cls,
session);
ret = TMH_RESPONSE_reply_refund_success (connection,
ref);
TMH_plugin->free_coin_transaction_list (TMH_plugin->cls,
tl);
return ret;
}
/* check currency is compatible */
if ( (GNUNET_YES !=
TALER_amount_cmp_currency (&refund->refund_amount,
&dep->amount_with_fee)) ||
(GNUNET_YES !=
TALER_amount_cmp_currency (&refund->refund_fee,
&dep->deposit_fee)) )
{
GNUNET_break_op (0); /* currency missmatch */
TMH_plugin->rollback (TMH_plugin->cls,
session);
return TMH_RESPONSE_reply_refund_failure (connection,
MHD_HTTP_PRECONDITION_FAILED);
}
/* check if we already send the money for the /deposit */
done = TMH_plugin->test_deposit_done (TMH_plugin->cls,
session,
dep);
if (GNUNET_SYSERR == done)
{
/* Internal error, we first had the deposit in the history,
but now it is gone? */
GNUNET_break (0);
TMH_plugin->free_coin_transaction_list (TMH_plugin->cls,
tl);
TMH_plugin->rollback (TMH_plugin->cls,
session);
return TMH_RESPONSE_reply_internal_error (connection,
"database inconsistent");
}
if (GNUNET_YES == done)
{
/* money was already transferred to merchant, can no longer refund */
TMH_plugin->rollback (TMH_plugin->cls,
session);
TMH_plugin->free_coin_transaction_list (TMH_plugin->cls,
tl);
return TMH_RESPONSE_reply_refund_failure (connection,
MHD_HTTP_GONE);
}
/* We no longer need 'tl' or 'dep' or 'ref' */
TMH_plugin->free_coin_transaction_list (TMH_plugin->cls,
tl);
/* check refund amount is sufficiently low */
if (1 == TALER_amount_cmp (&refund->refund_amount,
&dep->amount_with_fee) )
{
GNUNET_break_op (0); /* cannot refund more than original value */
return TMH_RESPONSE_reply_refund_failure (connection,
MHD_HTTP_PRECONDITION_FAILED);
}
/* Check refund fee matches fee of denomination key! */
mks = TMH_KS_acquire ();
dki = TMH_KS_denomination_key_lookup (mks,
&dep->coin.denom_pub,
TMH_KS_DKU_DEPOSIT);
if (NULL == dki)
{
/* DKI not found, but we do have a coin with this DK in our database;
not good... */
GNUNET_break (0);
TMH_KS_release (mks);
return TMH_RESPONSE_reply_internal_error (connection,
"denomination key not found");
}
TALER_amount_ntoh (&expect_fee,
&dki->issue.properties.fee_refund);
fee_cmp = TALER_amount_cmp (&refund->refund_fee,
&expect_fee);
TMH_KS_release (mks);
if (-1 == fee_cmp)
{
TMH_plugin->rollback (TMH_plugin->cls,
session);
return TMH_RESPONSE_reply_arg_invalid (connection,
"refund_fee");
}
if (1 == fee_cmp)
{
GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
"Refund fee proposed by merchant is higher than necessary.\n");
}
/* Finally, store new refund data */
if (GNUNET_OK !=
TMH_plugin->insert_refund (TMH_plugin->cls,
session,
refund))
{
TALER_LOG_WARNING ("Failed to store /refund information in database\n");
TMH_plugin->rollback (TMH_plugin->cls,
session);
return TMH_RESPONSE_reply_internal_db_error (connection);
}
COMMIT_TRANSACTION(session, connection);
return TMH_RESPONSE_reply_refund_success (connection,
refund);
}
/**
* Execute a /reserve/status. Given the public key of a reserve,
* return the associated transaction history.

14
src/exchange/taler-exchange-httpd_db.h
View File

@ -40,6 +40,20 @@ TMH_DB_execute_deposit (struct MHD_Connection *connection,
const struct TALER_EXCHANGEDB_Deposit *deposit);
/**
* Execute a "/refund". Returns a confirmation that the refund
* was successful, or a failure if we are not aware of a matching
* /deposit or if it is too late to do the refund.
*
* @param connection the MHD connection to handle
* @param refund refund details
* @return MHD result code
*/
int
TMH_DB_execute_refund (struct MHD_Connection *connection,
const struct TALER_EXCHANGEDB_Refund *refund);
/**
* Execute a "/reserve/status". Given the public key of a reserve,
* return the associated transaction history.

20
src/exchange/taler-exchange-httpd_refund.c
View File

@ -63,6 +63,21 @@ verify_and_execute_refund (struct MHD_Connection *connection,
&refund->refund_fee);
dr.merchant = refund->merchant_pub;
dr.coin_pub = refund->coin.coin_pub;
if (GNUNET_YES !=
TALER_amount_cmp_currency (&refund->refund_amount,
&refund->refund_fee) )
{
GNUNET_break_op (0);
return TMH_RESPONSE_reply_arg_invalid (connection,
"refund_fee");
}
if (-1 == TALER_amount_cmp (&refund->refund_amount,
&refund->refund_fee) )
{
GNUNET_break_op (0);
return TMH_RESPONSE_reply_signature_invalid (connection,
"refund_amount");
}
if (GNUNET_OK !=
GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_MERCHANT_REFUND,
&dr.purpose,
@ -73,13 +88,8 @@ verify_and_execute_refund (struct MHD_Connection *connection,
return TMH_RESPONSE_reply_signature_invalid (connection,
"merchant_sig");
}
#if 1
GNUNET_break (0); // FIXME: not implemented
return MHD_NO;
#else
return TMH_DB_execute_refund (connection,
refund);
#endif
}

80
src/exchange/taler-exchange-httpd_responses.c
View File

@ -642,6 +642,86 @@ compile_reserve_history (const struct TALER_EXCHANGEDB_ReserveHistory *rh,
}
/**
* Generate refund conflict failure message. Returns the
* transaction list @a tl with the details about the conflict.
*
* @param connection connection to the client
* @param tl transaction list showing the conflict
* @return MHD result code
*/
int
TMH_RESPONSE_reply_refund_conflict (struct MHD_Connection *connection,
const struct TALER_EXCHANGEDB_TransactionList *tl)
{
return TMH_RESPONSE_reply_json_pack (connection,
MHD_HTTP_CONFLICT,
"{s:s, s:o}",
"status", "conflicting refund",
"history", compile_transaction_history (tl));
}
/**
* Generate generic refund failure message. All the details
* are in the @a response_code. The body can be empty.
*
* @param connection connection to the client
* @param response_code response code to generate
* @return MHD result code
*/
int
TMH_RESPONSE_reply_refund_failure (struct MHD_Connection *connection,
unsigned int response_code)
{
return TMH_RESPONSE_reply_json_pack (connection,
response_code,
"{s:s}",
"error",
"no details");
}
/**
* Generate successful refund confirmation message.
*
* @param connection connection to the client
* @param refund details about the successful refund
* @return MHD result code
*/
int
TMH_RESPONSE_reply_refund_success (struct MHD_Connection *connection,
const struct TALER_EXCHANGEDB_Refund *refund)
{
struct TALER_RefundConfirmationPS rc;
struct TALER_ExchangePublicKeyP pub;
struct TALER_ExchangeSignatureP sig;
rc.purpose.purpose = htonl (TALER_SIGNATURE_EXCHANGE_CONFIRM_REFUND);
rc.purpose.size = htonl (sizeof (struct TALER_RefundConfirmationPS));
rc.h_contract = refund->h_contract;
rc.transaction_id = GNUNET_htonll (refund->transaction_id);
rc.coin_pub = refund->coin.coin_pub;
rc.merchant = refund->merchant_pub;
rc.rtransaction_id = GNUNET_htonll (refund->rtransaction_id);
TALER_amount_hton (&rc.refund_amount,
&refund->refund_amount);
TALER_amount_hton (&rc.refund_fee,
&refund->refund_fee);
TMH_KS_sign (&rc.purpose,
&pub,
&sig);
return TMH_RESPONSE_reply_json_pack (connection,
MHD_HTTP_OK,
"{s:s, s:o, s:o}",
"status", "REFUND_OK",
"sig", GNUNET_JSON_from_data (&sig,
sizeof (sig)),
"pub", GNUNET_JSON_from_data (&pub,
sizeof (pub)));
}
/**
* Send reserve status information to client.
*

38
src/exchange/taler-exchange-httpd_responses.h
View File

@ -247,6 +247,44 @@ TMH_RESPONSE_reply_deposit_insufficient_funds (struct MHD_Connection *connection
const struct TALER_EXCHANGEDB_TransactionList *tl);
/**
* Generate refund conflict failure message. Returns the
* transaction list @a tl with the details about the conflict.
*
* @param connection connection to the client
* @param tl transaction list showing the conflict
* @return MHD result code
*/
int
TMH_RESPONSE_reply_refund_conflict (struct MHD_Connection *connection,
const struct TALER_EXCHANGEDB_TransactionList *tl);
/**
* Generate generic refund failure message. All the details
* are in the @a response_code. The body can be empty.
*
* @param connection connection to the client
* @param response_code response code to generate
* @return MHD result code
*/
int
TMH_RESPONSE_reply_refund_failure (struct MHD_Connection *connection,
unsigned int response_code);
/**
* Generate successful refund confirmation message.
*
* @param connection connection to the client
* @param refund details about the successful refund
* @return MHD result code
*/
int
TMH_RESPONSE_reply_refund_success (struct MHD_Connection *connection,
const struct TALER_EXCHANGEDB_Refund *refund);
/**
* A merchant asked for details about a deposit, but
* we do not know anything about the deposit. Generate the

5
src/exchangedb/plugin_exchangedb_common.c
View File

@ -1,6 +1,6 @@
/*
This file is part of TALER
Copyright (C) 2015 GNUnet e.V.
Copyright (C) 2015, 2016 Inria & GNUnet e.V.
TALER is free software; you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software
@ -107,6 +107,9 @@ common_free_coin_transaction_list (void *cls,
case TALER_EXCHANGEDB_TT_REFRESH_MELT:
GNUNET_free (list->details.melt);
break;
case TALER_EXCHANGEDB_TT_REFUND:
GNUNET_free (list->details.refund);
break;
}
GNUNET_free (list);
list = next;

40
src/exchangedb/plugin_exchangedb_postgres.c
View File

@ -2176,6 +2176,26 @@ postgres_mark_deposit_tiny (void *cls,
}
/**
* Test if a deposit was marked as done, thereby declaring that it cannot be
* refunded anymore.
*
* @param cls the @e cls of this struct with the plugin-specific state
* @param session connection to the database
* @param deposit the deposit to check
* @return #GNUNET_YES if is is marked done done, #GNUNET_NO if not,
* #GNUNET_SYSERR on error (deposit unknown)
*/
static int
postgres_test_deposit_done (void *cls,
struct TALER_EXCHANGEDB_Session *session,
const struct TALER_EXCHANGEDB_Deposit *deposit)
{
GNUNET_break (0); // not implemented
return GNUNET_SYSERR;
}
/**
* Mark a deposit as done, thereby declaring that it cannot be
* executed at all anymore, and should no longer be returned by
@ -2466,6 +2486,24 @@ postgres_insert_deposit (void *cls,
}
/**
* Insert information about refunded coin into the database.
*
* @param cls the @e cls of this struct with the plugin-specific state
* @param session connection to the database
* @param refund refund information to store
* @return #GNUNET_OK on success, #GNUNET_SYSERR on error
*/
static int
postgres_insert_refund (void *cls,
struct TALER_EXCHANGEDB_Session *session,
const struct TALER_EXCHANGEDB_Refund *refund)
{
GNUNET_break (0); // not implemented
return GNUNET_SYSERR;
}
/**
* Lookup refresh session data under the given @a session_hash.
*
@ -4242,10 +4280,12 @@ libtaler_plugin_exchangedb_postgres_init (void *cls)
plugin->free_reserve_history = &common_free_reserve_history;
plugin->have_deposit = &postgres_have_deposit;
plugin->mark_deposit_tiny = &postgres_mark_deposit_tiny;
plugin->test_deposit_done = &postgres_test_deposit_done;
plugin->mark_deposit_done = &postgres_mark_deposit_done;
plugin->get_ready_deposit = &postgres_get_ready_deposit;
plugin->iterate_matching_deposits = &postgres_iterate_matching_deposits;
plugin->insert_deposit = &postgres_insert_deposit;
plugin->insert_refund = &postgres_insert_refund;
plugin->get_refresh_session = &postgres_get_refresh_session;
plugin->create_refresh_session = &postgres_create_refresh_session;
plugin->insert_refresh_melt = &postgres_insert_refresh_melt;

42
src/include/taler_exchangedb_plugin.h
View File

@ -499,7 +499,12 @@ enum TALER_EXCHANGEDB_TransactionType
/**
* /refresh/melt operation.
*/
TALER_EXCHANGEDB_TT_REFRESH_MELT = 1
TALER_EXCHANGEDB_TT_REFRESH_MELT = 1,
/**
* /refund operation.
*/
TALER_EXCHANGEDB_TT_REFUND = 2
};
@ -536,6 +541,11 @@ struct TALER_EXCHANGEDB_TransactionList
*/
struct TALER_EXCHANGEDB_RefreshMelt *melt;
/**
* Details if transaction was a /refund operation.
*/
struct TALER_EXCHANGEDB_Refund *refund;
} details;
};
@ -953,6 +963,20 @@ struct TALER_EXCHANGEDB_Plugin
const struct TALER_EXCHANGEDB_Deposit *deposit);
/**
* Insert information about refunded coin into the database.
*
* @param cls the @e cls of this struct with the plugin-specific state
* @param session connection to the database
* @param refund refund information to store
* @return #GNUNET_OK on success, #GNUNET_SYSERR on error
*/
int
(*insert_refund) (void *cls,
struct TALER_EXCHANGEDB_Session *session,
const struct TALER_EXCHANGEDB_Refund *refund);
/**
* Mark a deposit as tiny, thereby declaring that it cannot be
* executed by itself and should no longer be returned by
@ -969,6 +993,22 @@ struct TALER_EXCHANGEDB_Plugin
unsigned long long rowid);
/**
* Test if a deposit was marked as done, thereby declaring that it cannot be
* refunded anymore.
*
* @param cls the @e cls of this struct with the plugin-specific state
* @param session connection to the database
* @param deposit the deposit to check
* @return #GNUNET_YES if is is marked done done, #GNUNET_NO if not,
* #GNUNET_SYSERR on error (deposit unknown)
*/
int
(*test_deposit_done) (void *cls,
struct TALER_EXCHANGEDB_Session *session,
const struct TALER_EXCHANGEDB_Deposit *deposit);
/**
* Mark a deposit as done, thereby declaring that it cannot be
* executed at all anymore, and should no longer be returned by