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Diffstat (limited to 'common/json/src/json_checker.c')
| -rw-r--r-- | common/json/src/json_checker.c | 421 |
1 files changed, 421 insertions, 0 deletions
diff --git a/common/json/src/json_checker.c b/common/json/src/json_checker.c new file mode 100644 index 0000000..33491ed --- /dev/null +++ b/common/json/src/json_checker.c @@ -0,0 +1,421 @@ +/* JSON_checker.c */ + +/* 2016-11-11 */ + +/* +Copyright (c) 2005 JSON.org + +Permission is hereby granted, free of charge, to any person obtaining a copy +of this software and associated documentation files (the "Software"), to deal +in the Software without restriction, including without limitation the rights +to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +copies of the Software, and to permit persons to whom the Software is +furnished to do so, subject to the following conditions: + +The above copyright notice and this permission notice shall be included in all +copies or substantial portions of the Software. + +The Software shall be used for Good, not Evil. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +SOFTWARE. +*/ + +#include <stdlib.h> +#include "json_checker.h" + +#define TRUE 1 +#define FALSE 0 +#define GOOD 0xBABAB00E +#define __ -1 /* the universal error code */ + +/* + Characters are mapped into these 31 character classes. This allows for + a significant reduction in the size of the state transition table. +*/ + +enum classes { + C_SPACE, /* space */ + C_WHITE, /* other whitespace */ + C_LCURB, /* { */ + C_RCURB, /* } */ + C_LSQRB, /* [ */ + C_RSQRB, /* ] */ + C_COLON, /* : */ + C_COMMA, /* , */ + C_QUOTE, /* " */ + C_BACKS, /* \ */ + C_SLASH, /* / */ + C_PLUS, /* + */ + C_MINUS, /* - */ + C_POINT, /* . */ + C_ZERO , /* 0 */ + C_DIGIT, /* 123456789 */ + C_LOW_A, /* a */ + C_LOW_B, /* b */ + C_LOW_C, /* c */ + C_LOW_D, /* d */ + C_LOW_E, /* e */ + C_LOW_F, /* f */ + C_LOW_L, /* l */ + C_LOW_N, /* n */ + C_LOW_R, /* r */ + C_LOW_S, /* s */ + C_LOW_T, /* t */ + C_LOW_U, /* u */ + C_ABCDF, /* ABCDF */ + C_E, /* E */ + C_ETC, /* everything else */ + NR_CLASSES +}; + +static int ascii_class[128] = { +/* + This array maps the 128 ASCII characters into character classes. + The remaining Unicode characters should be mapped to C_ETC. + Non-whitespace control characters are errors. +*/ + __, __, __, __, __, __, __, __, + __, C_WHITE, C_WHITE, __, __, C_WHITE, __, __, + __, __, __, __, __, __, __, __, + __, __, __, __, __, __, __, __, + + C_SPACE, C_ETC, C_QUOTE, C_ETC, C_ETC, C_ETC, C_ETC, C_ETC, + C_ETC, C_ETC, C_ETC, C_PLUS, C_COMMA, C_MINUS, C_POINT, C_SLASH, + C_ZERO, C_DIGIT, C_DIGIT, C_DIGIT, C_DIGIT, C_DIGIT, C_DIGIT, C_DIGIT, + C_DIGIT, C_DIGIT, C_COLON, C_ETC, C_ETC, C_ETC, C_ETC, C_ETC, + + C_ETC, C_ABCDF, C_ABCDF, C_ABCDF, C_ABCDF, C_E, C_ABCDF, C_ETC, + C_ETC, C_ETC, C_ETC, C_ETC, C_ETC, C_ETC, C_ETC, C_ETC, + C_ETC, C_ETC, C_ETC, C_ETC, C_ETC, C_ETC, C_ETC, C_ETC, + C_ETC, C_ETC, C_ETC, C_LSQRB, C_BACKS, C_RSQRB, C_ETC, C_ETC, + + C_ETC, C_LOW_A, C_LOW_B, C_LOW_C, C_LOW_D, C_LOW_E, C_LOW_F, C_ETC, + C_ETC, C_ETC, C_ETC, C_ETC, C_LOW_L, C_ETC, C_LOW_N, C_ETC, + C_ETC, C_ETC, C_LOW_R, C_LOW_S, C_LOW_T, C_LOW_U, C_ETC, C_ETC, + C_ETC, C_ETC, C_ETC, C_LCURB, C_ETC, C_RCURB, C_ETC, C_ETC +}; + + +/* + The state codes. +*/ +enum states { + GO, /* start */ + OK, /* ok */ + OB, /* object */ + KE, /* key */ + CO, /* colon */ + VA, /* value */ + AR, /* array */ + ST, /* string */ + ES, /* escape */ + U1, /* u1 */ + U2, /* u2 */ + U3, /* u3 */ + U4, /* u4 */ + MI, /* minus */ + ZE, /* zero */ + IN, /* integer */ + FR, /* fraction */ + FS, /* fraction */ + E1, /* e */ + E2, /* ex */ + E3, /* exp */ + T1, /* tr */ + T2, /* tru */ + T3, /* true */ + F1, /* fa */ + F2, /* fal */ + F3, /* fals */ + F4, /* false */ + N1, /* nu */ + N2, /* nul */ + N3, /* null */ + NR_STATES +}; + + +static int state_transition_table[NR_STATES][NR_CLASSES] = { +/* + The state transition table takes the current state and the current symbol, + and returns either a new state or an action. An action is represented as a + negative number. A JSON text is accepted if at the end of the text the + state is OK and if the mode is MODE_DONE. + + white 1-9 ABCDF etc + space | { } [ ] : , " \ / + - . 0 | a b c d e f l n r s t u | E |*/ +/*start GO*/ {GO,GO,-6,__,-5,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__}, +/*ok OK*/ {OK,OK,__,-8,__,-7,__,-3,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__}, +/*object OB*/ {OB,OB,__,-9,__,__,__,__,ST,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__}, +/*key KE*/ {KE,KE,__,__,__,__,__,__,ST,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__}, +/*colon CO*/ {CO,CO,__,__,__,__,-2,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__}, +/*value VA*/ {VA,VA,-6,__,-5,__,__,__,ST,__,__,__,MI,__,ZE,IN,__,__,__,__,__,F1,__,N1,__,__,T1,__,__,__,__}, +/*array AR*/ {AR,AR,-6,__,-5,-7,__,__,ST,__,__,__,MI,__,ZE,IN,__,__,__,__,__,F1,__,N1,__,__,T1,__,__,__,__}, +/*string ST*/ {ST,__,ST,ST,ST,ST,ST,ST,-4,ES,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST}, +/*escape ES*/ {__,__,__,__,__,__,__,__,ST,ST,ST,__,__,__,__,__,__,ST,__,__,__,ST,__,ST,ST,__,ST,U1,__,__,__}, +/*u1 U1*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,U2,U2,U2,U2,U2,U2,U2,U2,__,__,__,__,__,__,U2,U2,__}, +/*u2 U2*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,U3,U3,U3,U3,U3,U3,U3,U3,__,__,__,__,__,__,U3,U3,__}, +/*u3 U3*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,U4,U4,U4,U4,U4,U4,U4,U4,__,__,__,__,__,__,U4,U4,__}, +/*u4 U4*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,ST,ST,ST,ST,ST,ST,ST,ST,__,__,__,__,__,__,ST,ST,__}, +/*minus MI*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,ZE,IN,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__}, +/*zero ZE*/ {OK,OK,__,-8,__,-7,__,-3,__,__,__,__,__,FR,__,__,__,__,__,__,E1,__,__,__,__,__,__,__,__,E1,__}, +/*int IN*/ {OK,OK,__,-8,__,-7,__,-3,__,__,__,__,__,FR,IN,IN,__,__,__,__,E1,__,__,__,__,__,__,__,__,E1,__}, +/*frac FR*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,FS,FS,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__}, +/*fracs FS*/ {OK,OK,__,-8,__,-7,__,-3,__,__,__,__,__,__,FS,FS,__,__,__,__,E1,__,__,__,__,__,__,__,__,E1,__}, +/*e E1*/ {__,__,__,__,__,__,__,__,__,__,__,E2,E2,__,E3,E3,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__}, +/*ex E2*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,E3,E3,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__}, +/*exp E3*/ {OK,OK,__,-8,__,-7,__,-3,__,__,__,__,__,__,E3,E3,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__}, +/*tr T1*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,T2,__,__,__,__,__,__}, +/*tru T2*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,T3,__,__,__}, +/*true T3*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,OK,__,__,__,__,__,__,__,__,__,__}, +/*fa F1*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,F2,__,__,__,__,__,__,__,__,__,__,__,__,__,__}, +/*fal F2*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,F3,__,__,__,__,__,__,__,__}, +/*fals F3*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,F4,__,__,__,__,__}, +/*false F4*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,OK,__,__,__,__,__,__,__,__,__,__}, +/*nu N1*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,N2,__,__,__}, +/*nul N2*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,N3,__,__,__,__,__,__,__,__}, +/*null N3*/ {__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,__,OK,__,__,__,__,__,__,__,__} +}; + + +/* + These modes can be pushed on the stack. +*/ +enum modes { + MODE_ARRAY, + MODE_DONE, + MODE_KEY, + MODE_OBJECT +}; + +static void +destroy(JSON_checker jc) +{ +/* + Delete the JSON_checker object. +*/ + jc->valid = 0; + free((void*)jc->stack); + free((void*)jc); +} + + +static int +reject(JSON_checker jc) +{ +/* + Delete the JSON_checker object. +*/ + destroy(jc); + return FALSE; +} + + +static int +push(JSON_checker jc, int mode) +{ +/* + Push a mode onto the stack. Return false if there is overflow. +*/ + jc->top += 1; + if (jc->top >= jc->depth) { + return FALSE; + } + jc->stack[jc->top] = mode; + return TRUE; +} + + +static int +pop(JSON_checker jc, int mode) +{ +/* + Pop the stack, assuring that the current mode matches the expectation. + Return false if there is underflow or if the modes mismatch. +*/ + if (jc->top < 0 || jc->stack[jc->top] != mode) { + return FALSE; + } + jc->top -= 1; + return TRUE; +} + + +JSON_checker +new_JSON_checker(int depth) +{ +/* + new_JSON_checker starts the checking process by constructing a JSON_checker + object. It takes a depth parameter that restricts the level of maximum + nesting. + + To continue the process, call JSON_checker_char for each character in the + JSON text, and then call JSON_checker_done to obtain the final result. + These functions are fully reentrant. + + The JSON_checker object will be deleted by JSON_checker_done. + JSON_checker_char will delete the JSON_checker object if it sees an error. +*/ + JSON_checker jc = (JSON_checker)malloc(sizeof(struct JSON_checker_struct)); + jc->valid = GOOD; + jc->state = GO; + jc->depth = depth; + jc->top = -1; + jc->stack = (int*)calloc(depth, sizeof(int)); + push(jc, MODE_DONE); + return jc; +} + + +int +JSON_checker_char(JSON_checker jc, int next_char) +{ +/* + After calling new_JSON_checker, call this function for each character (or + partial character) in your JSON text. It can accept UTF-8, UTF-16, or + UTF-32. It returns TRUE if things are looking ok so far. If it rejects the + text, it destroys the JSON_checker object and returns false. +*/ + int next_class, next_state; +/* + Determine the character's class. +*/ + if (jc->valid != GOOD) { + return FALSE; + } + if (next_char < 0) { + return reject(jc); + } + if (next_char >= 128) { + next_class = C_ETC; + } else { + next_class = ascii_class[next_char]; + if (next_class <= __) { + return reject(jc); + } + } +/* + Get the next state from the state transition table. +*/ + next_state = state_transition_table[jc->state][next_class]; + if (next_state >= 0) { +/* + Change the state. +*/ + jc->state = next_state; +/* + Or perform one of the actions. +*/ + } else { + switch (next_state) { +/* empty } */ + case -9: + if (!pop(jc, MODE_KEY)) { + return reject(jc); + } + jc->state = OK; + break; + +/* } */ case -8: + if (!pop(jc, MODE_OBJECT)) { + return reject(jc); + } + jc->state = OK; + break; + +/* ] */ case -7: + if (!pop(jc, MODE_ARRAY)) { + return reject(jc); + } + jc->state = OK; + break; + +/* { */ case -6: + if (!push(jc, MODE_KEY)) { + return reject(jc); + } + jc->state = OB; + break; + +/* [ */ case -5: + if (!push(jc, MODE_ARRAY)) { + return reject(jc); + } + jc->state = AR; + break; + +/* " */ case -4: + switch (jc->stack[jc->top]) { + case MODE_KEY: + jc->state = CO; + break; + case MODE_ARRAY: + case MODE_OBJECT: + jc->state = OK; + break; + default: + return reject(jc); + } + break; + +/* , */ case -3: + switch (jc->stack[jc->top]) { + case MODE_OBJECT: +/* + A comma causes a flip from object mode to key mode. +*/ + if (!pop(jc, MODE_OBJECT) || !push(jc, MODE_KEY)) { + return reject(jc); + } + jc->state = KE; + break; + case MODE_ARRAY: + jc->state = VA; + break; + default: + return reject(jc); + } + break; + +/* : */ case -2: +/* + A colon causes a flip from key mode to object mode. +*/ + if (!pop(jc, MODE_KEY) || !push(jc, MODE_OBJECT)) { + return reject(jc); + } + jc->state = VA; + break; +/* + Bad action. +*/ + default: + return reject(jc); + } + } + return TRUE; +} + + +int +JSON_checker_done(JSON_checker jc) +{ +/* + The JSON_checker_done function should be called after all of the characters + have been processed, but only if every call to JSON_checker_char returned + true. This function deletes the JSON_checker and returns true if the JSON + text was accepted. +*/ + if (jc->valid != GOOD) { + return FALSE; + } + int result = jc->state == OK && pop(jc, MODE_DONE); + destroy(jc); + return result; +} |