diff options
Diffstat (limited to 'src/util/support/json.c')
| -rw-r--r-- | src/util/support/json.c | 1092 |
1 files changed, 1092 insertions, 0 deletions
diff --git a/src/util/support/json.c b/src/util/support/json.c new file mode 100644 index 0000000000000..ae2feae974d33 --- /dev/null +++ b/src/util/support/json.c @@ -0,0 +1,1092 @@ +/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */ +/* util/support/json.c - JSON parser and unparser */ +/* + * Copyright (c) 2010 Kungliga Tekniska Högskolan + * (Royal Institute of Technology, Stockholm, Sweden). + * All rights reserved. + * + * Portions Copyright (c) 2010 Apple Inc. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * 3. Neither the name of the Institute nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ +/* + * Copyright (C) 2012 by the Massachusetts Institute of Technology. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, + * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED + * OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/* + * This file implements a minimal dynamic type system for JSON values and a + * JSON encoder and decoder. It is loosely based on the heimbase code from + * Heimdal. + */ + +#include <k5-platform.h> +#include <k5-base64.h> +#include <k5-json.h> +#include <k5-buf.h> + +#define MAX_DECODE_DEPTH 64 +#define MIN_ALLOC_SLOT 16 + +typedef void (*type_dealloc_fn)(void *val); + +typedef struct json_type_st { + k5_json_tid tid; + const char *name; + type_dealloc_fn dealloc; +} *json_type; + +struct value_base { + json_type isa; + unsigned int ref_cnt; +}; + +#define PTR2BASE(ptr) (((struct value_base *)ptr) - 1) +#define BASE2PTR(ptr) ((void *)(((struct value_base *)ptr) + 1)) + +k5_json_value +k5_json_retain(k5_json_value val) +{ + struct value_base *p; + + if (val == NULL) + return val; + p = PTR2BASE(val); + assert(p->ref_cnt != 0); + p->ref_cnt++; + return val; +} + +void +k5_json_release(k5_json_value val) +{ + struct value_base *p; + + if (val == NULL) + return; + p = PTR2BASE(val); + assert(p->ref_cnt != 0); + p->ref_cnt--; + if (p->ref_cnt == 0) { + if (p->isa->dealloc != NULL) + p->isa->dealloc(val); + free(p); + } +} + +/* Get the type description of a k5_json_value. */ +static json_type +get_isa(k5_json_value val) +{ + struct value_base *p = PTR2BASE(val); + + return p->isa; +} + +k5_json_tid +k5_json_get_tid(k5_json_value val) +{ + json_type isa = get_isa(val); + + return isa->tid; +} + +static k5_json_value +alloc_value(json_type type, size_t size) +{ + struct value_base *p = calloc(1, size + sizeof(*p)); + + if (p == NULL) + return NULL; + p->isa = type; + p->ref_cnt = 1; + + return BASE2PTR(p); +} + +/*** Null type ***/ + +static struct json_type_st null_type = { K5_JSON_TID_NULL, "null", NULL }; + +int +k5_json_null_create(k5_json_null *val_out) +{ + *val_out = alloc_value(&null_type, 0); + return (*val_out == NULL) ? ENOMEM : 0; +} + +int +k5_json_null_create_val(k5_json_value *val_out) +{ + *val_out = alloc_value(&null_type, 0); + return (*val_out == NULL) ? ENOMEM : 0; +} + +/*** Boolean type ***/ + +static struct json_type_st bool_type = { K5_JSON_TID_BOOL, "bool", NULL }; + +int +k5_json_bool_create(int truth, k5_json_bool *val_out) +{ + k5_json_bool b; + + *val_out = NULL; + b = alloc_value(&bool_type, 1); + if (b == NULL) + return ENOMEM; + *(unsigned char *)b = !!truth; + *val_out = b; + return 0; +} + +int +k5_json_bool_value(k5_json_bool bval) +{ + return *(unsigned char *)bval; +} + +/*** Array type ***/ + +struct k5_json_array_st { + k5_json_value *values; + size_t len; + size_t allocated; +}; + +static void +array_dealloc(void *ptr) +{ + k5_json_array array = ptr; + size_t i; + + for (i = 0; i < array->len; i++) + k5_json_release(array->values[i]); + free(array->values); +} + +static struct json_type_st array_type = { + K5_JSON_TID_ARRAY, "array", array_dealloc +}; + +int +k5_json_array_create(k5_json_array *val_out) +{ + *val_out = alloc_value(&array_type, sizeof(struct k5_json_array_st)); + return (*val_out == NULL) ? ENOMEM : 0; +} + +int +k5_json_array_add(k5_json_array array, k5_json_value val) +{ + k5_json_value *ptr; + size_t new_alloc; + + if (array->len >= array->allocated) { + /* Increase the number of slots by 50% (MIN_ALLOC_SLOT minimum). */ + new_alloc = array->len + 1 + (array->len >> 1); + if (new_alloc < MIN_ALLOC_SLOT) + new_alloc = MIN_ALLOC_SLOT; + ptr = realloc(array->values, new_alloc * sizeof(*array->values)); + if (ptr == NULL) + return ENOMEM; + array->values = ptr; + array->allocated = new_alloc; + } + array->values[array->len++] = k5_json_retain(val); + return 0; +} + +size_t +k5_json_array_length(k5_json_array array) +{ + return array->len; +} + +k5_json_value +k5_json_array_get(k5_json_array array, size_t idx) +{ + if (idx >= array->len) + abort(); + return array->values[idx]; +} + +void +k5_json_array_set(k5_json_array array, size_t idx, k5_json_value val) +{ + if (idx >= array->len) + abort(); + k5_json_release(array->values[idx]); + array->values[idx] = k5_json_retain(val); +} + +int +k5_json_array_fmt(k5_json_array *array_out, const char *template, ...) +{ + const char *p; + va_list ap; + const char *cstring; + unsigned char *data; + size_t len; + long long nval; + k5_json_array array; + k5_json_value val; + k5_json_number num; + k5_json_string str; + k5_json_bool b; + k5_json_null null; + int truth, ret; + + *array_out = NULL; + if (k5_json_array_create(&array)) + return ENOMEM; + va_start(ap, template); + for (p = template; *p != '\0'; p++) { + switch (*p) { + case 'v': + val = k5_json_retain(va_arg(ap, k5_json_value)); + break; + case 'n': + if (k5_json_null_create(&null)) + goto err; + val = null; + break; + case 'b': + truth = va_arg(ap, int); + if (k5_json_bool_create(truth, &b)) + goto err; + val = b; + break; + case 'i': + nval = va_arg(ap, int); + if (k5_json_number_create(nval, &num)) + goto err; + val = num; + break; + case 'L': + nval = va_arg(ap, long long); + if (k5_json_number_create(nval, &num)) + goto err; + val = num; + break; + case 's': + cstring = va_arg(ap, const char *); + if (cstring == NULL) { + if (k5_json_null_create(&null)) + goto err; + val = null; + } else { + if (k5_json_string_create(cstring, &str)) + goto err; + val = str; + } + break; + case 'B': + data = va_arg(ap, unsigned char *); + len = va_arg(ap, size_t); + if (k5_json_string_create_base64(data, len, &str)) + goto err; + val = str; + break; + default: + goto err; + } + ret = k5_json_array_add(array, val); + k5_json_release(val); + if (ret) + goto err; + } + va_end(ap); + *array_out = array; + return 0; + +err: + va_end(ap); + k5_json_release(array); + return ENOMEM; +} + +/*** Object type (string:value mapping) ***/ + +struct entry { + char *key; + k5_json_value value; +}; + +struct k5_json_object_st { + struct entry *entries; + size_t len; + size_t allocated; +}; + +static void +object_dealloc(void *ptr) +{ + k5_json_object obj = ptr; + size_t i; + + for (i = 0; i < obj->len; i++) { + free(obj->entries[i].key); + k5_json_release(obj->entries[i].value); + } + free(obj->entries); +} + +static struct json_type_st object_type = { + K5_JSON_TID_OBJECT, "object", object_dealloc +}; + +int +k5_json_object_create(k5_json_object *val_out) +{ + *val_out = alloc_value(&object_type, sizeof(struct k5_json_object_st)); + return (*val_out == NULL) ? ENOMEM : 0; +} + +size_t +k5_json_object_count(k5_json_object obj) +{ + return obj->len; +} + +/* Return the entry for key within obj, or NULL if none exists. */ +static struct entry * +object_search(k5_json_object obj, const char *key) +{ + size_t i; + + for (i = 0; i < obj->len; i++) { + if (strcmp(key, obj->entries[i].key) == 0) + return &obj->entries[i]; + } + return NULL; +} + +k5_json_value +k5_json_object_get(k5_json_object obj, const char *key) +{ + struct entry *ent; + + ent = object_search(obj, key); + if (ent == NULL) + return NULL; + return ent->value; +} + +int +k5_json_object_set(k5_json_object obj, const char *key, k5_json_value val) +{ + struct entry *ent, *ptr; + size_t new_alloc, i; + + ent = object_search(obj, key); + if (ent != NULL) { + k5_json_release(ent->value); + if (val == NULL) { + /* Remove this key. */ + free(ent->key); + for (i = ent - obj->entries; i < obj->len - 1; i++) + obj->entries[i] = obj->entries[i + 1]; + obj->len--; + } else { + /* Overwrite this key's value with the new one. */ + ent->value = k5_json_retain(val); + } + return 0; + } + + /* If didn't find a key the caller asked to remove, do nothing. */ + if (val == NULL) + return 0; + + if (obj->len >= obj->allocated) { + /* Increase the number of slots by 50% (MIN_ALLOC_SLOT minimum). */ + new_alloc = obj->len + 1 + (obj->len >> 1); + if (new_alloc < MIN_ALLOC_SLOT) + new_alloc = MIN_ALLOC_SLOT; + ptr = realloc(obj->entries, new_alloc * sizeof(*obj->entries)); + if (ptr == NULL) + return ENOMEM; + obj->entries = ptr; + obj->allocated = new_alloc; + } + obj->entries[obj->len].key = strdup(key); + if (obj->entries[obj->len].key == NULL) + return ENOMEM; + obj->entries[obj->len].value = k5_json_retain(val); + obj->len++; + return 0; +} + +void +k5_json_object_iterate(k5_json_object obj, k5_json_object_iterator_fn func, + void *arg) +{ + size_t i; + + for (i = 0; i < obj->len; i++) + func(arg, obj->entries[i].key, obj->entries[i].value); +} + +/*** String type ***/ + +static struct json_type_st string_type = { + K5_JSON_TID_STRING, "string", NULL +}; + +int +k5_json_string_create(const char *cstring, k5_json_string *val_out) +{ + return k5_json_string_create_len(cstring, strlen(cstring), val_out); +} + +int +k5_json_string_create_len(const void *data, size_t len, + k5_json_string *val_out) +{ + char *s; + + *val_out = NULL; + s = alloc_value(&string_type, len + 1); + if (s == NULL) + return ENOMEM; + if (len > 0) + memcpy(s, data, len); + s[len] = '\0'; + *val_out = (k5_json_string)s; + return 0; +} + +int +k5_json_string_create_base64(const void *data, size_t len, + k5_json_string *val_out) +{ + char *base64; + int ret; + + *val_out = NULL; + base64 = k5_base64_encode(data, len); + if (base64 == NULL) + return ENOMEM; + ret = k5_json_string_create(base64, val_out); + free(base64); + return ret; +} + +const char * +k5_json_string_utf8(k5_json_string string) +{ + return (const char *)string; +} + +int +k5_json_string_unbase64(k5_json_string string, unsigned char **data_out, + size_t *len_out) +{ + unsigned char *data; + size_t len; + + *data_out = NULL; + *len_out = 0; + data = k5_base64_decode((const char *)string, &len); + if (data == NULL) + return (len == 0) ? ENOMEM : EINVAL; + *data_out = data; + *len_out = len; + return 0; +} + +/*** Number type ***/ + +static struct json_type_st number_type = { + K5_JSON_TID_NUMBER, "number", NULL +}; + +int +k5_json_number_create(long long number, k5_json_number *val_out) +{ + k5_json_number n; + + *val_out = NULL; + n = alloc_value(&number_type, sizeof(long long)); + if (n == NULL) + return ENOMEM; + *((long long *)n) = number; + *val_out = n; + return 0; +} + +long long +k5_json_number_value(k5_json_number number) +{ + return *(long long *)number; +} + +/*** JSON encoding ***/ + +static const char quotemap_json[] = "\"\\/bfnrt"; +static const char quotemap_c[] = "\"\\/\b\f\n\r\t"; +static const char needs_quote[] = "\\\"\1\2\3\4\5\6\7\10\11\12\13\14\15\16\17" + "\20\21\22\23\24\25\26\27\30\31\32\33\34\35\36\37"; + +static int encode_value(struct k5buf *buf, k5_json_value val); + +static void +encode_string(struct k5buf *buf, const char *str) +{ + size_t n; + const char *p; + + k5_buf_add(buf, "\""); + while (*str != '\0') { + n = strcspn(str, needs_quote); + k5_buf_add_len(buf, str, n); + str += n; + if (*str == '\0') + break; + k5_buf_add(buf, "\\"); + p = strchr(quotemap_c, *str); + if (p != NULL) + k5_buf_add_len(buf, quotemap_json + (p - quotemap_c), 1); + else + k5_buf_add_fmt(buf, "u00%02X", (unsigned int)*str); + str++; + } + k5_buf_add(buf, "\""); +} + +struct obj_ctx { + struct k5buf *buf; + int ret; + int first; +}; + +static void +encode_obj_entry(void *ctx, const char *key, k5_json_value value) +{ + struct obj_ctx *j = ctx; + + if (j->ret) + return; + if (j->first) + j->first = 0; + else + k5_buf_add(j->buf, ","); + encode_string(j->buf, key); + k5_buf_add(j->buf, ":"); + j->ret = encode_value(j->buf, value); +} + +static int +encode_value(struct k5buf *buf, k5_json_value val) +{ + k5_json_tid type; + int ret; + size_t i, len; + struct obj_ctx ctx; + + if (val == NULL) + return EINVAL; + + type = k5_json_get_tid(val); + switch (type) { + case K5_JSON_TID_ARRAY: + k5_buf_add(buf, "["); + len = k5_json_array_length(val); + for (i = 0; i < len; i++) { + if (i != 0) + k5_buf_add(buf, ","); + ret = encode_value(buf, k5_json_array_get(val, i)); + if (ret) + return ret; + } + k5_buf_add(buf, "]"); + return 0; + + case K5_JSON_TID_OBJECT: + k5_buf_add(buf, "{"); + ctx.buf = buf; + ctx.ret = 0; + ctx.first = 1; + k5_json_object_iterate(val, encode_obj_entry, &ctx); + k5_buf_add(buf, "}"); + return ctx.ret; + + case K5_JSON_TID_STRING: + encode_string(buf, k5_json_string_utf8(val)); + return 0; + + case K5_JSON_TID_NUMBER: + k5_buf_add_fmt(buf, "%lld", k5_json_number_value(val)); + return 0; + + case K5_JSON_TID_NULL: + k5_buf_add(buf, "null"); + return 0; + + case K5_JSON_TID_BOOL: + k5_buf_add(buf, k5_json_bool_value(val) ? "true" : "false"); + return 0; + + default: + return EINVAL; + } +} + +int +k5_json_encode(k5_json_value val, char **json_out) +{ + struct k5buf buf; + int ret; + + *json_out = NULL; + k5_buf_init_dynamic(&buf); + ret = encode_value(&buf, val); + if (ret) { + k5_buf_free(&buf); + return ret; + } + if (k5_buf_status(&buf) != 0) + return ENOMEM; + *json_out = buf.data; + return 0; +} + +/*** JSON decoding ***/ + +struct decode_ctx { + const unsigned char *p; + size_t depth; +}; + +static int parse_value(struct decode_ctx *ctx, k5_json_value *val_out); + +/* Consume whitespace. Return 0 if there is anything left to parse after the + * whitespace, -1 if not. */ +static int +white_spaces(struct decode_ctx *ctx) +{ + unsigned char c; + + for (; *ctx->p != '\0'; ctx->p++) { + c = *ctx->p; + if (c != ' ' && c != '\t' && c != '\r' && c != '\n') + return 0; + } + return -1; +} + +/* Return true if c is a decimal digit. */ +static inline int +is_digit(unsigned char c) +{ + return ('0' <= c && c <= '9'); +} + +/* Return true if c is a hexadecimal digit (per RFC 5234 HEXDIG). */ +static inline int +is_hex_digit(unsigned char c) +{ + return is_digit(c) || ('A' <= c && c <= 'F'); +} + +/* Return the numeric value of a hex digit; aborts if c is not a hex digit. */ +static inline unsigned int +hexval(unsigned char c) +{ + if (is_digit(c)) + return c - '0'; + else if ('A' <= c && c <= 'F') + return c - 'A' + 10; + abort(); +} + +/* Parse a JSON number (which must be an integer in the signed 64-bit range; we + * do not allow floating-point numbers). */ +static int +parse_number(struct decode_ctx *ctx, k5_json_number *val_out) +{ + const unsigned long long umax = ~0ULL, smax = (1ULL << 63) - 1; + unsigned long long number = 0; + int neg = 1; + + *val_out = NULL; + + if (*ctx->p == '-') { + neg = -1; + ctx->p++; + } + + if (!is_digit(*ctx->p)) + return EINVAL; + + /* Read the number into an unsigned 64-bit container, ensuring that we + * don't overflow it. */ + while (is_digit(*ctx->p)) { + if (number + 1 > umax / 10) + return EOVERFLOW; + number = (number * 10) + (*ctx->p - '0'); + ctx->p++; + } + + /* Make sure the unsigned 64-bit value fits in the signed 64-bit range. */ + if (number > smax + 1 || (number > smax && neg == 1)) + return EOVERFLOW; + + return k5_json_number_create(number * neg, val_out); +} + +/* Parse a JSON string (which must not quote Unicode code points above 256). */ +static int +parse_string(struct decode_ctx *ctx, char **str_out) +{ + const unsigned char *p, *start, *end = NULL; + const char *q; + char *buf, *pos; + unsigned int code; + + *str_out = NULL; + + /* Find the start and end of the string. */ + if (*ctx->p != '"') + return EINVAL; + start = ++ctx->p; + for (; *ctx->p != '\0'; ctx->p++) { + if (*ctx->p == '\\') { + ctx->p++; + if (*ctx->p == '\0') + return EINVAL; + } else if (*ctx->p == '"') { + end = ctx->p++; + break; + } + } + if (end == NULL) + return EINVAL; + + pos = buf = malloc(end - start + 1); + if (buf == NULL) + return ENOMEM; + for (p = start; p < end;) { + if (*p == '\\') { + p++; + if (*p == 'u' && is_hex_digit(p[1]) && is_hex_digit(p[2]) && + is_hex_digit(p[3]) && is_hex_digit(p[4])) { + code = (hexval(p[1]) << 12) | (hexval(p[2]) << 8) | + (hexval(p[3]) << 4) | hexval(p[4]); + if (code <= 0xff) { + *pos++ = code; + } else { + /* Code points above 0xff don't need to be quoted, so we + * don't implement translating those into UTF-8. */ + free(buf); + return EINVAL; + } + p += 5; + } else { + q = strchr(quotemap_json, *p); + if (q != NULL) { + *pos++ = quotemap_c[q - quotemap_json]; + } else { + free(buf); + return EINVAL; + } + p++; + } + } else { + *pos++ = *p++; + } + } + *pos = '\0'; + *str_out = buf; + return 0; +} + +/* Parse an object association and place it into obj. */ +static int +parse_object_association(k5_json_object obj, struct decode_ctx *ctx) +{ + char *key = NULL; + k5_json_value val; + int ret; + + /* Parse the key and value. */ + ret = parse_string(ctx, &key); + if (ret) + return ret; + if (white_spaces(ctx)) + goto invalid; + if (*ctx->p != ':') + goto invalid; + ctx->p++; + if (white_spaces(ctx)) + goto invalid; + ret = parse_value(ctx, &val); + if (ret) { + free(key); + return ret; + } + + /* Add the key and value to obj. */ + ret = k5_json_object_set(obj, key, val); + free(key); + k5_json_release(val); + return ret; + +invalid: + free(key); + return EINVAL; +} + +/* Parse a JSON object. */ +static int +parse_object(struct decode_ctx *ctx, k5_json_object *val_out) +{ + k5_json_object obj = NULL; + int ret; + + *val_out = NULL; + + /* Parse past the opening brace. */ + if (*ctx->p != '{') + return EINVAL; + ctx->p++; + if (white_spaces(ctx)) + return EINVAL; + + ret = k5_json_object_create(&obj); + if (ret) + return ret; + + /* Pairs associations until we reach the terminating brace. */ + if (*ctx->p != '}') { + while (1) { + ret = parse_object_association(obj, ctx); + if (ret) { + k5_json_release(obj); + return ret; + } + if (white_spaces(ctx)) + goto invalid; + if (*ctx->p == '}') + break; + if (*ctx->p != ',') + goto invalid; + ctx->p++; + if (white_spaces(ctx)) + goto invalid; + } + } + ctx->p++; + *val_out = obj; + return 0; + +invalid: + k5_json_release(obj); + return EINVAL; +} + +/* Parse an value and place it into array. */ +static int +parse_array_item(k5_json_array array, struct decode_ctx *ctx) +{ + k5_json_value val; + int ret; + + ret = parse_value(ctx, &val); + if (ret) + return ret; + ret = k5_json_array_add(array, val); + k5_json_release(val); + return ret; +} + +/* Parse a JSON array. */ +static int +parse_array(struct decode_ctx *ctx, k5_json_array *val_out) +{ + k5_json_array array = NULL; + int ret; + + *val_out = NULL; + + /* Parse past the opening bracket. */ + if (*ctx->p != '[') + return EINVAL; + ctx->p++; + if (white_spaces(ctx)) + return EINVAL; + + ret = k5_json_array_create(&array); + if (ret) + return ret; + + /* Pairs values until we reach the terminating bracket. */ + if (*ctx->p != ']') { + while (1) { + ret = parse_array_item(array, ctx); + if (ret) { + k5_json_release(array); + return ret; + } + if (white_spaces(ctx)) + goto invalid; + if (*ctx->p == ']') + break; + if (*ctx->p != ',') + goto invalid; + ctx->p++; + if (white_spaces(ctx)) + goto invalid; + } + } + ctx->p++; + *val_out = array; + return 0; + +invalid: + k5_json_release(array); + return EINVAL; +} + +/* Parse a JSON value of any type. */ +static int +parse_value(struct decode_ctx *ctx, k5_json_value *val_out) +{ + k5_json_null null; + k5_json_bool bval; + k5_json_number num; + k5_json_string str; + k5_json_object obj; + k5_json_array array; + char *cstring; + int ret; + + *val_out = NULL; + + if (white_spaces(ctx)) + return EINVAL; + + if (*ctx->p == '"') { + ret = parse_string(ctx, &cstring); + if (ret) + return ret; + ret = k5_json_string_create(cstring, &str); + free(cstring); + if (ret) + return ret; + *val_out = str; + } else if (*ctx->p == '{') { + if (ctx->depth-- == 1) + return EINVAL; + ret = parse_object(ctx, &obj); + if (ret) + return ret; + ctx->depth++; + *val_out = obj; + } else if (*ctx->p == '[') { + if (ctx->depth-- == 1) + return EINVAL; + ret = parse_array(ctx, &array); + ctx->depth++; + *val_out = array; + } else if (is_digit(*ctx->p) || *ctx->p == '-') { + ret = parse_number(ctx, &num); + if (ret) + return ret; + *val_out = num; + } else if (strncmp((char *)ctx->p, "null", 4) == 0) { + ctx->p += 4; + ret = k5_json_null_create(&null); + if (ret) + return ret; + *val_out = null; + } else if (strncmp((char *)ctx->p, "true", 4) == 0) { + ctx->p += 4; + ret = k5_json_bool_create(1, &bval); + if (ret) + return ret; + *val_out = bval; + } else if (strncmp((char *)ctx->p, "false", 5) == 0) { + ctx->p += 5; + ret = k5_json_bool_create(0, &bval); + if (ret) + return ret; + *val_out = bval; + } else { + return EINVAL; + } + + return 0; +} + +int +k5_json_decode(const char *string, k5_json_value *val_out) +{ + struct decode_ctx ctx; + k5_json_value val; + int ret; + + *val_out = NULL; + ctx.p = (unsigned char *)string; + ctx.depth = MAX_DECODE_DEPTH; + ret = parse_value(&ctx, &val); + if (ret) + return ret; + if (white_spaces(&ctx) == 0) { + k5_json_release(val); + return EINVAL; + } + *val_out = val; + return 0; +} |
