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add generic json parser interpreter to simplify parsing logic (next)

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This commit is contained in:
Christian Grothoff 2015-06-20 17:40:28 +02:00
parent 5c780a7a97
commit 605058f774
3 changed files with 595 additions and 0 deletions
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1
src/mint-lib/Makefile.am
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@ -15,6 +15,7 @@ libtalermint_la_LDFLAGS = \
libtalermint_la_SOURCES = \
mint_api_context.c mint_api_context.h \
mint_api_json.c mint_api_json.h \
mint_api_handle.c mint_api_handle.h
libtalermint_la_LIBADD = \

404
src/mint-lib/mint_api_json.c Normal file
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@ -0,0 +1,404 @@
/*
This file is part of TALER
Copyright (C) 2014, 2015 GNUnet e.V.
TALER is free software; you can redistribute it and/or modify it under the
terms of the GNU Affero General Public License as published by the Free Software
Foundation; either version 3, or (at your option) any later version.
TALER is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License along with
TALER; see the file COPYING. If not, If not, see <http://www.gnu.org/licenses/>
*/
/**
* @file mint-lib/mint_api_json.c
* @brief functions to parse incoming requests (JSON snippets)
* @author Florian Dold
* @author Benedikt Mueller
* @author Christian Grothoff
*/
#include "platform.h"
#include "mint_api_json.h"
/**
* Parse absolute time specified in JSON format. The JSON format is
* "/TIMEVAL/" where TIMEVAL is in milliseconds. Additionally, we
* support "/forever/" to represent the end of time.
*
* @param f json specification of the amount
* @param[out] time set to the time specified in @a f
* @return
* #GNUNET_YES if parsing was successful
* #GNUNET_SYSERR on errors
*/
static int
parse_time_abs (json_t *f,
struct GNUNET_TIME_Absolute *time)
{
const char *val;
size_t slen;
unsigned long long int tval;
char *endp;
val = json_string_value (f);
if (NULL == val)
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
slen = strlen (val);
if ( (slen <= 2) ||
('/' != val[0]) ||
('/' != val[slen - 1]) )
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
if (0 == strcasecmp (val,
"/forever/"))
{
*time = GNUNET_TIME_UNIT_FOREVER_ABS;
return GNUNET_OK;
}
tval = strtoull (&val[1],
&endp,
10);
if (&val[slen - 1] != endp)
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
/* Time is in 'ms' in JSON, but in microseconds in GNUNET_TIME_Absolute */
time->abs_value_us = tval * 1000LL;
if ( (time->abs_value_us) / 1000LL != tval)
{
/* Integer overflow */
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
return GNUNET_OK;
}
/**
* Parse amount specified in JSON format.
*
* @param f json specification of the amount
* @param[out] amount set to the amount specified in @a f
* @return
* #GNUNET_OK if parsing was successful
* #GNUNET_SYSERR on error
*/
static int
parse_amount (json_t *f,
struct TALER_Amount *amount)
{
json_int_t value;
json_int_t fraction;
const char *currency;
memset (amount,
0,
sizeof (struct TALER_Amount));
if (-1 == json_unpack (f,
"{s:I, s:I, s:s}",
"value", &value,
"fraction", &fraction,
"currency", &currency))
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
if ( (value < 0) ||
(fraction < 0) ||
(value > UINT64_MAX) ||
(fraction > UINT32_MAX) )
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
if (strlen (currency) >= TALER_CURRENCY_LEN)
{
GNUNET_break_op (0);
return GNUNET_SYSERR;
}
amount->value = (uint64_t) value;
amount->fraction = (uint32_t) fraction;
strcpy (amount->currency, currency);
(void) TALER_amount_normalize (amount);
return GNUNET_OK;
}
/**
* Navigate and parse data in a JSON tree.
*
* @param root the JSON node to start the navigation at.
* @param spec parse specification array
* @return offset in @a spec where parsing failed, -1 on success (!)
*/
static int
parse_json (json_t *root,
struct MAJ_Specification *spec)
{
int i;
json_t *pos; /* what's our current position? */
pos = root;
for (i=0;MAJ_CMD_END != spec[i].cmd;i++)
{
pos = json_object_get (root,
spec[i].field);
if (NULL == pos)
{
GNUNET_break_op (0);
return i;
}
switch (spec[i].cmd)
{
case MAJ_CMD_END:
GNUNET_assert (0);
return i;
case MAJ_CMD_AMOUNT:
if (GNUNET_OK !=
parse_amount (pos,
spec[i].details.amount))
return i;
break;
case MAJ_CMD_TIME_ABSOLUTE:
if (GNUNET_OK !=
parse_time_abs (pos,
spec[i].details.abs_time))
return i;
break;
case MAJ_CMD_BINARY_FIXED:
{
const char *str;
int res;
str = json_string_value (pos);
if (NULL == str)
{
GNUNET_break_op (0);
return i;
}
res = GNUNET_STRINGS_string_to_data (str, strlen (str),
spec[i].details.fixed_data.dest,
spec[i].details.fixed_data.dest_len);
if (GNUNET_OK != res)
{
GNUNET_break_op (0);
return i;
}
}
break;
case MAJ_CMD_BINARY_VARIABLE:
{
const char *str;
size_t len;
void *data;
int res;
str = json_string_value (pos);
if (NULL == str)
{
GNUNET_break_op (0);
return i;
}
len = (strlen (str) * 5) / 8;
if (len >= 1024)
{
GNUNET_break_op (0);
return i;
}
data = GNUNET_malloc (len);
res = GNUNET_STRINGS_string_to_data (str, strlen (str),
data,
len);
if (GNUNET_OK != res)
{
GNUNET_break_op (0);
GNUNET_free (data);
return i;
}
*spec[i].details.variable_data.dest_p = data;
*spec[i].details.variable_data.dest_len_p = len;
}
break;
case MAJ_CMD_RSA_PUBLIC_KEY:
{
size_t len;
const char *str;
int res;
void *buf;
str = json_string_value (root);
if (NULL == str)
{
GNUNET_break_op (0);
return i;
}
len = (strlen (str) * 5) / 8;
buf = GNUNET_malloc (len);
res = GNUNET_STRINGS_string_to_data (str,
strlen (str),
buf,
len);
if (GNUNET_OK != res)
{
GNUNET_free (buf);
GNUNET_break_op (0);
return i;
}
*spec[i].details.rsa_public_key
= GNUNET_CRYPTO_rsa_public_key_decode (buf,
len);
GNUNET_free (buf);
if (NULL == spec[i].details.rsa_public_key)
{
GNUNET_break_op (0);
return i;
}
}
break;
case MAJ_CMD_RSA_SIGNATURE:
{
size_t len;
const char *str;
int res;
void *buf;
str = json_string_value (root);
if (NULL == str)
{
GNUNET_break_op (0);
return i;
}
len = (strlen (str) * 5) / 8;
buf = GNUNET_malloc (len);
res = GNUNET_STRINGS_string_to_data (str,
strlen (str),
buf,
len);
if (GNUNET_OK != res)
{
GNUNET_free (buf);
GNUNET_break_op (0);
return i;
}
*spec[i].details.rsa_signature
= GNUNET_CRYPTO_rsa_signature_decode (buf,
len);
GNUNET_free (buf);
if (NULL == spec[i].details.rsa_signature)
return i;
}
break;
default:
GNUNET_break (0);
return i;
}
}
return -1; /* all OK! */
}
/**
* Free all elements allocated during a
* #MAJ_parse_json() operation.
*
* @param spec specification of the parse operation
* @param end number of elements in @a spec to process
*/
static void
parse_free (struct MAJ_Specification *spec,
int end)
{
int i;
for (i=0;i<end;i++)
{
switch (spec[i].cmd)
{
case MAJ_CMD_END:
GNUNET_assert (0);
return;
case MAJ_CMD_AMOUNT:
break;
case MAJ_CMD_TIME_ABSOLUTE:
break;
case MAJ_CMD_BINARY_FIXED:
break;
case MAJ_CMD_BINARY_VARIABLE:
GNUNET_free (*spec[i].details.variable_data.dest_p);
*spec[i].details.variable_data.dest_p = NULL;
*spec[i].details.variable_data.dest_len_p = 0;
break;
case MAJ_CMD_RSA_PUBLIC_KEY:
GNUNET_CRYPTO_rsa_public_key_free (*spec[i].details.rsa_public_key);
*spec[i].details.rsa_public_key = NULL;
break;
case MAJ_CMD_RSA_SIGNATURE:
GNUNET_CRYPTO_rsa_signature_free (*spec[i].details.rsa_signature);
*spec[i].details.rsa_signature = NULL;
break;
default:
GNUNET_break (0);
break;
}
}
}
/**
* Navigate and parse data in a JSON tree.
*
* @param root the JSON node to start the navigation at.
* @param spec parse specification array
* @return #GNUNET_OK on success, #GNUNET_SYSERR on error
*/
int
MAJ_parse_json (const json_t *root,
struct MAJ_Specification *spec)
{
int ret;
ret = parse_json ((json_t *) root,
spec);
if (-1 == ret)
return GNUNET_OK;
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"JSON field `%s` had unexpected value\n",
spec[ret].field);
parse_free (spec, ret);
return GNUNET_SYSERR;
}
/**
* Free all elements allocated during a
* #MAJ_parse_json() operation.
*
* @param spec specification of the parse operation
*/
void
MAJ_parse_free (struct MAJ_Specification *spec)
{
int i;
for (i=0;MAJ_CMD_END != spec[i].cmd;i++) ;
parse_free (spec, i);
}
/* end of mint_api_json.c */

190
src/mint-lib/mint_api_json.h Normal file
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@ -0,0 +1,190 @@
/*
This file is part of TALER
Copyright (C) 2014, 2015 GNUnet e.V.
TALER is free software; you can redistribute it and/or modify it under the
terms of the GNU Affero General Public License as published by the Free Software
Foundation; either version 3, or (at your option) any later version.
TALER is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License along with
TALER; see the file COPYING. If not, If not, see <http://www.gnu.org/licenses/>
*/
/**
* @file mint-lib/mint_api_json.h
* @brief functions to parse incoming requests (JSON snippets)
* @author Florian Dold
* @author Benedikt Mueller
* @author Christian Grothoff
*/
#include "platform.h"
#include <gnunet/gnunet_util_lib.h>
#include "taler_util.h"
#include <jansson.h>
/**
* Enumeration with the various commands for the
* #MAJ_parse_json interpreter.
*/
enum MAJ_Command
{
/**
* End of command list.
*/
MAJ_CMD_END,
/**
* Parse amount at current position.
*/
MAJ_CMD_AMOUNT,
/**
* Parse absolute time at current position.
*/
MAJ_CMD_TIME_ABSOLUTE,
/**
* Parse fixed binary value at current position.
*/
MAJ_CMD_BINARY_FIXED,
/**
* Parse variable-size binary value at current position.
*/
MAJ_CMD_BINARY_VARIABLE,
/**
* Parse RSA public key at current position.
*/
MAJ_CMD_RSA_PUBLIC_KEY,
/**
* Parse RSA signature at current position.
*/
MAJ_CMD_RSA_SIGNATURE,
/**
* Parse at current position.
*/
MAJ_CMD_A,
/**
* Parse at current position.
*/
MAJ_CMD_B,
/**
* Parse at current position.
*/
MAJ_CMD_C
};
/**
* Entry in parser specification for #MAJ_parse_json.
*/
struct MAJ_Specification
{
/**
* Command to execute.
*/
enum MAJ_Command cmd;
/**
* Name of the field to access.
*/
const char *field;
/**
* Further details for the command.
*/
union {
/**
* Where to store amount for #MAJ_CMD_AMOUNT.
*/
struct TALER_Amount *amount;
/**
* Where to store time, for #MAJ_CMD_TIME_ABSOLUTE.
*/
struct GNUNET_TIME_Absolute *abs_time;
/**
* Where to write binary data, for #MAJ_CMD_BINARY_FIXED.
*/
struct {
/**
* Where to write the data.
*/
void *dest;
/**
* How many bytes to write to @e dest.
*/
size_t dest_len;
} fixed_data;
/**
* Where to write binary data, for #MAJ_CMD_BINARY_VARIABLE.
*/
struct {
/**
* Where to store the pointer with the data (is allocated).
*/
void **dest_p;
/**
* Where to store the number of bytes allocated at `*dest`.
*/
size_t *dest_len_p;
} variable_data;
/**
* Where to store the RSA public key for #MAJ_CMD_RSA_PUBLIC_KEY
*/
struct GNUNET_CRYPTO_rsa_PublicKey **rsa_public_key;
/**
* Where to store the RSA signature for #MAJ_CMD_RSA_SIGNATURE
*/
struct GNUNET_CRYPTO_rsa_Signature **rsa_signature;
} details;
};
/**
* Navigate and parse data in a JSON tree.
*
* @param root the JSON node to start the navigation at.
* @param spec parse specification array
* @return #GNUNET_OK on success, #GNUNET_SYSERR on error
*/
int
MAJ_parse_json (const json_t *root,
struct MAJ_Specification *spec);
/**
* Free all elements allocated during a
* #MAJ_parse_json() operation.
*
* @param spec specification of the parse operation
*/
void
MAJ_parse_free (struct MAJ_Specification *spec);
/* end of mint_api_json.h */