diff options
Diffstat (limited to 'qapi/string-input-visitor.c')
-rw-r--r-- | qapi/string-input-visitor.c | 414 |
1 files changed, 414 insertions, 0 deletions
diff --git a/qapi/string-input-visitor.c b/qapi/string-input-visitor.c new file mode 100644 index 000000000..197139c1c --- /dev/null +++ b/qapi/string-input-visitor.c @@ -0,0 +1,414 @@ +/* + * String parsing visitor + * + * Copyright Red Hat, Inc. 2012-2016 + * + * Author: Paolo Bonzini <pbonzini@redhat.com> + * David Hildenbrand <david@redhat.com> + * + * This work is licensed under the terms of the GNU LGPL, version 2.1 or later. + * See the COPYING.LIB file in the top-level directory. + */ + +#include "qemu/osdep.h" +#include "qapi/error.h" +#include "qapi/string-input-visitor.h" +#include "qapi/visitor-impl.h" +#include "qapi/qmp/qerror.h" +#include "qapi/qmp/qnull.h" +#include "qemu/option.h" +#include "qemu/cutils.h" + +typedef enum ListMode { + /* no list parsing active / no list expected */ + LM_NONE, + /* we have an unparsed string remaining */ + LM_UNPARSED, + /* we have an unfinished int64 range */ + LM_INT64_RANGE, + /* we have an unfinished uint64 range */ + LM_UINT64_RANGE, + /* we have parsed the string completely and no range is remaining */ + LM_END, +} ListMode; + +/* protect against DOS attacks, limit the amount of elements per range */ +#define RANGE_MAX_ELEMENTS 65536 + +typedef union RangeElement { + int64_t i64; + uint64_t u64; +} RangeElement; + +struct StringInputVisitor +{ + Visitor visitor; + + /* List parsing state */ + ListMode lm; + RangeElement rangeNext; + RangeElement rangeEnd; + const char *unparsed_string; + void *list; + + /* The original string to parse */ + const char *string; +}; + +static StringInputVisitor *to_siv(Visitor *v) +{ + return container_of(v, StringInputVisitor, visitor); +} + +static bool start_list(Visitor *v, const char *name, GenericList **list, + size_t size, Error **errp) +{ + StringInputVisitor *siv = to_siv(v); + + assert(siv->lm == LM_NONE); + siv->list = list; + siv->unparsed_string = siv->string; + + if (!siv->string[0]) { + if (list) { + *list = NULL; + } + siv->lm = LM_END; + } else { + if (list) { + *list = g_malloc0(size); + } + siv->lm = LM_UNPARSED; + } + return true; +} + +static GenericList *next_list(Visitor *v, GenericList *tail, size_t size) +{ + StringInputVisitor *siv = to_siv(v); + + switch (siv->lm) { + case LM_END: + return NULL; + case LM_INT64_RANGE: + case LM_UINT64_RANGE: + case LM_UNPARSED: + /* we have an unparsed string or something left in a range */ + break; + default: + abort(); + } + + tail->next = g_malloc0(size); + return tail->next; +} + +static bool check_list(Visitor *v, Error **errp) +{ + const StringInputVisitor *siv = to_siv(v); + + switch (siv->lm) { + case LM_INT64_RANGE: + case LM_UINT64_RANGE: + case LM_UNPARSED: + error_setg(errp, "Fewer list elements expected"); + return false; + case LM_END: + return true; + default: + abort(); + } +} + +static void end_list(Visitor *v, void **obj) +{ + StringInputVisitor *siv = to_siv(v); + + assert(siv->lm != LM_NONE); + assert(siv->list == obj); + siv->list = NULL; + siv->unparsed_string = NULL; + siv->lm = LM_NONE; +} + +static int try_parse_int64_list_entry(StringInputVisitor *siv, int64_t *obj) +{ + const char *endptr; + int64_t start, end; + + /* parse a simple int64 or range */ + if (qemu_strtoi64(siv->unparsed_string, &endptr, 0, &start)) { + return -EINVAL; + } + end = start; + + switch (endptr[0]) { + case '\0': + siv->unparsed_string = endptr; + break; + case ',': + siv->unparsed_string = endptr + 1; + break; + case '-': + /* parse the end of the range */ + if (qemu_strtoi64(endptr + 1, &endptr, 0, &end)) { + return -EINVAL; + } + if (start > end || end - start >= RANGE_MAX_ELEMENTS) { + return -EINVAL; + } + switch (endptr[0]) { + case '\0': + siv->unparsed_string = endptr; + break; + case ',': + siv->unparsed_string = endptr + 1; + break; + default: + return -EINVAL; + } + break; + default: + return -EINVAL; + } + + /* we have a proper range (with maybe only one element) */ + siv->lm = LM_INT64_RANGE; + siv->rangeNext.i64 = start; + siv->rangeEnd.i64 = end; + return 0; +} + +static bool parse_type_int64(Visitor *v, const char *name, int64_t *obj, + Error **errp) +{ + StringInputVisitor *siv = to_siv(v); + int64_t val; + + switch (siv->lm) { + case LM_NONE: + /* just parse a simple int64, bail out if not completely consumed */ + if (qemu_strtoi64(siv->string, NULL, 0, &val)) { + error_setg(errp, QERR_INVALID_PARAMETER_VALUE, + name ? name : "null", "int64"); + return false; + } + *obj = val; + return true; + case LM_UNPARSED: + if (try_parse_int64_list_entry(siv, obj)) { + error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name ? name : "null", + "list of int64 values or ranges"); + return false; + } + assert(siv->lm == LM_INT64_RANGE); + /* fall through */ + case LM_INT64_RANGE: + /* return the next element in the range */ + assert(siv->rangeNext.i64 <= siv->rangeEnd.i64); + *obj = siv->rangeNext.i64++; + + if (siv->rangeNext.i64 > siv->rangeEnd.i64 || *obj == INT64_MAX) { + /* end of range, check if there is more to parse */ + siv->lm = siv->unparsed_string[0] ? LM_UNPARSED : LM_END; + } + return true; + case LM_END: + error_setg(errp, "Fewer list elements expected"); + return false; + default: + abort(); + } +} + +static int try_parse_uint64_list_entry(StringInputVisitor *siv, uint64_t *obj) +{ + const char *endptr; + uint64_t start, end; + + /* parse a simple uint64 or range */ + if (qemu_strtou64(siv->unparsed_string, &endptr, 0, &start)) { + return -EINVAL; + } + end = start; + + switch (endptr[0]) { + case '\0': + siv->unparsed_string = endptr; + break; + case ',': + siv->unparsed_string = endptr + 1; + break; + case '-': + /* parse the end of the range */ + if (qemu_strtou64(endptr + 1, &endptr, 0, &end)) { + return -EINVAL; + } + if (start > end || end - start >= RANGE_MAX_ELEMENTS) { + return -EINVAL; + } + switch (endptr[0]) { + case '\0': + siv->unparsed_string = endptr; + break; + case ',': + siv->unparsed_string = endptr + 1; + break; + default: + return -EINVAL; + } + break; + default: + return -EINVAL; + } + + /* we have a proper range (with maybe only one element) */ + siv->lm = LM_UINT64_RANGE; + siv->rangeNext.u64 = start; + siv->rangeEnd.u64 = end; + return 0; +} + +static bool parse_type_uint64(Visitor *v, const char *name, uint64_t *obj, + Error **errp) +{ + StringInputVisitor *siv = to_siv(v); + uint64_t val; + + switch (siv->lm) { + case LM_NONE: + /* just parse a simple uint64, bail out if not completely consumed */ + if (qemu_strtou64(siv->string, NULL, 0, &val)) { + error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name ? name : "null", + "uint64"); + return false; + } + *obj = val; + return true; + case LM_UNPARSED: + if (try_parse_uint64_list_entry(siv, obj)) { + error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name ? name : "null", + "list of uint64 values or ranges"); + return false; + } + assert(siv->lm == LM_UINT64_RANGE); + /* fall through */ + case LM_UINT64_RANGE: + /* return the next element in the range */ + assert(siv->rangeNext.u64 <= siv->rangeEnd.u64); + *obj = siv->rangeNext.u64++; + + if (siv->rangeNext.u64 > siv->rangeEnd.u64 || *obj == UINT64_MAX) { + /* end of range, check if there is more to parse */ + siv->lm = siv->unparsed_string[0] ? LM_UNPARSED : LM_END; + } + return true; + case LM_END: + error_setg(errp, "Fewer list elements expected"); + return false; + default: + abort(); + } +} + +static bool parse_type_size(Visitor *v, const char *name, uint64_t *obj, + Error **errp) +{ + StringInputVisitor *siv = to_siv(v); + uint64_t val; + + assert(siv->lm == LM_NONE); + if (!parse_option_size(name, siv->string, &val, errp)) { + return false; + } + + *obj = val; + return true; +} + +static bool parse_type_bool(Visitor *v, const char *name, bool *obj, + Error **errp) +{ + StringInputVisitor *siv = to_siv(v); + + assert(siv->lm == LM_NONE); + return qapi_bool_parse(name ? name : "null", siv->string, obj, errp); +} + +static bool parse_type_str(Visitor *v, const char *name, char **obj, + Error **errp) +{ + StringInputVisitor *siv = to_siv(v); + + assert(siv->lm == LM_NONE); + *obj = g_strdup(siv->string); + return true; +} + +static bool parse_type_number(Visitor *v, const char *name, double *obj, + Error **errp) +{ + StringInputVisitor *siv = to_siv(v); + double val; + + assert(siv->lm == LM_NONE); + if (qemu_strtod_finite(siv->string, NULL, &val)) { + error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null", + "number"); + return false; + } + + *obj = val; + return true; +} + +static bool parse_type_null(Visitor *v, const char *name, QNull **obj, + Error **errp) +{ + StringInputVisitor *siv = to_siv(v); + + assert(siv->lm == LM_NONE); + *obj = NULL; + + if (siv->string[0]) { + error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null", + "null"); + return false; + } + + *obj = qnull(); + return true; +} + +static void string_input_free(Visitor *v) +{ + StringInputVisitor *siv = to_siv(v); + + g_free(siv); +} + +Visitor *string_input_visitor_new(const char *str) +{ + StringInputVisitor *v; + + assert(str); + v = g_malloc0(sizeof(*v)); + + v->visitor.type = VISITOR_INPUT; + v->visitor.type_int64 = parse_type_int64; + v->visitor.type_uint64 = parse_type_uint64; + v->visitor.type_size = parse_type_size; + v->visitor.type_bool = parse_type_bool; + v->visitor.type_str = parse_type_str; + v->visitor.type_number = parse_type_number; + v->visitor.type_null = parse_type_null; + v->visitor.start_list = start_list; + v->visitor.next_list = next_list; + v->visitor.check_list = check_list; + v->visitor.end_list = end_list; + v->visitor.free = string_input_free; + + v->string = str; + v->lm = LM_NONE; + return &v->visitor; +} |