diff options
Diffstat (limited to 'Modules/_sqlite')
| -rw-r--r-- | Modules/_sqlite/statement.c | 119 |
1 files changed, 45 insertions, 74 deletions
diff --git a/Modules/_sqlite/statement.c b/Modules/_sqlite/statement.c index f9cb70f..aee4607 100644 --- a/Modules/_sqlite/statement.c +++ b/Modules/_sqlite/statement.c @@ -26,16 +26,7 @@ #include "util.h" /* prototypes */ -static int pysqlite_check_remaining_sql(const char* tail); - -typedef enum { - LINECOMMENT_1, - IN_LINECOMMENT, - COMMENTSTART_1, - IN_COMMENT, - COMMENTEND_1, - NORMAL -} parse_remaining_sql_state; +static const char *lstrip_sql(const char *sql); pysqlite_Statement * pysqlite_statement_create(pysqlite_Connection *connection, PyObject *sql) @@ -73,7 +64,7 @@ pysqlite_statement_create(pysqlite_Connection *connection, PyObject *sql) return NULL; } - if (pysqlite_check_remaining_sql(tail)) { + if (lstrip_sql(tail) != NULL) { PyErr_SetString(connection->ProgrammingError, "You can only execute one statement at a time."); goto error; @@ -82,20 +73,12 @@ pysqlite_statement_create(pysqlite_Connection *connection, PyObject *sql) /* Determine if the statement is a DML statement. SELECT is the only exception. See #9924. */ int is_dml = 0; - for (const char *p = sql_cstr; *p != 0; p++) { - switch (*p) { - case ' ': - case '\r': - case '\n': - case '\t': - continue; - } - + const char *p = lstrip_sql(sql_cstr); + if (p != NULL) { is_dml = (PyOS_strnicmp(p, "insert", 6) == 0) || (PyOS_strnicmp(p, "update", 6) == 0) || (PyOS_strnicmp(p, "delete", 6) == 0) || (PyOS_strnicmp(p, "replace", 7) == 0); - break; } pysqlite_Statement *self = PyObject_GC_New(pysqlite_Statement, @@ -139,73 +122,61 @@ stmt_traverse(pysqlite_Statement *self, visitproc visit, void *arg) } /* - * Checks if there is anything left in an SQL string after SQLite compiled it. - * This is used to check if somebody tried to execute more than one SQL command - * with one execute()/executemany() command, which the DB-API and we don't - * allow. + * Strip leading whitespace and comments from incoming SQL (null terminated C + * string) and return a pointer to the first non-whitespace, non-comment + * character. * - * Returns 1 if there is more left than should be. 0 if ok. + * This is used to check if somebody tries to execute more than one SQL query + * with one execute()/executemany() command, which the DB-API don't allow. + * + * It is also used to harden DML query detection. */ -static int pysqlite_check_remaining_sql(const char* tail) +static inline const char * +lstrip_sql(const char *sql) { - const char* pos = tail; - - parse_remaining_sql_state state = NORMAL; - - for (;;) { + // This loop is borrowed from the SQLite source code. + for (const char *pos = sql; *pos; pos++) { switch (*pos) { - case 0: - return 0; - case '-': - if (state == NORMAL) { - state = LINECOMMENT_1; - } else if (state == LINECOMMENT_1) { - state = IN_LINECOMMENT; - } - break; case ' ': case '\t': - break; + case '\f': case '\n': - case 13: - if (state == IN_LINECOMMENT) { - state = NORMAL; - } + case '\r': + // Skip whitespace. break; - case '/': - if (state == NORMAL) { - state = COMMENTSTART_1; - } else if (state == COMMENTEND_1) { - state = NORMAL; - } else if (state == COMMENTSTART_1) { - return 1; + case '-': + // Skip line comments. + if (pos[1] == '-') { + pos += 2; + while (pos[0] && pos[0] != '\n') { + pos++; + } + if (pos[0] == '\0') { + return NULL; + } + continue; } - break; - case '*': - if (state == NORMAL) { - return 1; - } else if (state == LINECOMMENT_1) { - return 1; - } else if (state == COMMENTSTART_1) { - state = IN_COMMENT; - } else if (state == IN_COMMENT) { - state = COMMENTEND_1; + return pos; + case '/': + // Skip C style comments. + if (pos[1] == '*') { + pos += 2; + while (pos[0] && (pos[0] != '*' || pos[1] != '/')) { + pos++; + } + if (pos[0] == '\0') { + return NULL; + } + pos++; + continue; } - break; + return pos; default: - if (state == COMMENTEND_1) { - state = IN_COMMENT; - } else if (state == IN_LINECOMMENT) { - } else if (state == IN_COMMENT) { - } else { - return 1; - } + return pos; } - - pos++; } - return 0; + return NULL; } static PyType_Slot stmt_slots[] = { |