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Diffstat (limited to '')
| -rw-r--r-- | src/liblzma/common/string_conversion.c | 1302 |
1 files changed, 1302 insertions, 0 deletions
diff --git a/src/liblzma/common/string_conversion.c b/src/liblzma/common/string_conversion.c new file mode 100644 index 00000000..04a70167 --- /dev/null +++ b/src/liblzma/common/string_conversion.c @@ -0,0 +1,1302 @@ +/////////////////////////////////////////////////////////////////////////////// +// +/// \file string_conversion.c +/// \brief Conversion of strings to filter chain and vice versa +// +// Author: Lasse Collin +// +// This file has been put into the public domain. +// You can do whatever you want with this file. +// +/////////////////////////////////////////////////////////////////////////////// + +#include "filter_common.h" + + +///////////////////// +// String building // +///////////////////// + +/// How much memory to allocate for strings. For now, no realloc is used +/// so this needs to be big enough even though there of course is +/// an overflow check still. +/// +/// FIXME? Using a fixed size is wasteful if the application doesn't free +/// the string fairly quickly but this can be improved later if needed. +#define STR_ALLOC_SIZE 800 + + +typedef struct { + char *buf; + size_t pos; +} lzma_str; + + +static lzma_ret +str_init(lzma_str *str, const lzma_allocator *allocator) +{ + str->buf = lzma_alloc(STR_ALLOC_SIZE, allocator); + if (str->buf == NULL) + return LZMA_MEM_ERROR; + + str->pos = 0; + return LZMA_OK; +} + + +static void +str_free(lzma_str *str, const lzma_allocator *allocator) +{ + lzma_free(str->buf, allocator); + return; +} + + +static bool +str_is_full(const lzma_str *str) +{ + return str->pos == STR_ALLOC_SIZE - 1; +} + + +static lzma_ret +str_finish(char **dest, lzma_str *str, const lzma_allocator *allocator) +{ + if (str_is_full(str)) { + // The preallocated buffer was too small. + // This shouldn't happen as STR_ALLOC_SIZE should + // be adjusted if new filters are added. + lzma_free(str->buf, allocator); + *dest = NULL; + assert(0); + return LZMA_PROG_ERROR; + } + + str->buf[str->pos] = '\0'; + *dest = str->buf; + return LZMA_OK; +} + + +static void +str_append_str(lzma_str *str, const char *s) +{ + const size_t len = strlen(s); + const size_t limit = STR_ALLOC_SIZE - 1 - str->pos; + const size_t copy_size = my_min(len, limit); + + memcpy(str->buf + str->pos, s, copy_size); + str->pos += copy_size; + return; +} + + +static void +str_append_u32(lzma_str *str, uint32_t v, bool use_byte_suffix) +{ + if (v == 0) { + str_append_str(str, "0"); + } else { + // NOTE: Don't use plain "B" because xz and the parser in this + // file don't support it and at glance it may look like 8 + // (there cannot be a space before the suffix). + static const char suffixes[4][4] = { "", "KiB", "MiB", "GiB" }; + + size_t suf = 0; + if (use_byte_suffix) { + while ((v & 1023) == 0 + && suf < ARRAY_SIZE(suffixes) - 1) { + v >>= 10; + ++suf; + } + } + + // UINT32_MAX in base 10 would need 10 + 1 bytes. Remember + // that initializing to "" initializes all elements to + // zero so '\0'-termination gets handled by this. + char buf[16] = ""; + size_t pos = sizeof(buf) - 1; + + do { + buf[--pos] = '0' + (v % 10); + v /= 10; + } while (v != 0); + + str_append_str(str, buf + pos); + str_append_str(str, suffixes[suf]); + } + + return; +} + + +////////////////////////////////////////////// +// Parsing and stringification declarations // +////////////////////////////////////////////// + +/// Maximum length for filter and option names. +/// 11 chars + terminating '\0' + sizeof(uint32_t) = 16 bytes +#define NAME_LEN_MAX 11 + + +/// For option_map.flags: Use .u.map to do convert the input value +/// to an integer. Without this flag, .u.range.{min,max} are used +/// as the allowed range for the integer. +#define OPTMAP_USE_NAME_VALUE_MAP 0x01 + +/// For option_map.flags: Allow KiB/MiB/GiB in input string and use them in +/// the stringified output if the value is an exact multiple of these. +/// This is used e.g. for LZMA1/2 dictionary size. +#define OPTMAP_USE_BYTE_SUFFIX 0x02 + +/// For option_map.flags: If the integer value is zero then this option +/// won't be included in the stringified output. It's used e.g. for +/// BCJ filter start offset which usually is zero. +#define OPTMAP_NO_STRFY_ZERO 0x04 + +/// Possible values for option_map.type. Since OPTMAP_TYPE_UINT32 is 0, +/// it doesn't need to be specified in the initializers as it is +/// the implicit value. +enum { + OPTMAP_TYPE_UINT32, + OPTMAP_TYPE_LZMA_MODE, + OPTMAP_TYPE_LZMA_MATCH_FINDER, + OPTMAP_TYPE_LZMA_PRESET, +}; + + +/// This is for mapping string values in options to integers. +/// The last element of an array must have "" as the name. +/// It's used e.g. for match finder names in LZMA1/2. +typedef struct { + const char name[NAME_LEN_MAX + 1]; + const uint32_t value; +} name_value_map; + + +/// Each filter that has options needs an array of option_map structures. +/// The array doesn't need to be terminated as the functions take the +/// length of the array as an argument. +/// +/// When converting a string to filter options structure, option values +/// will be handled in a few different ways: +/// +/// (1) If .type equals OPTMAP_TYPE_LZMA_PRESET then LZMA1/2 preset string +/// is handled specially. +/// +/// (2) If .flags has OPTMAP_USE_NAME_VALUE_MAP set then the string is +/// converted to an integer using the name_value_map pointed by .u.map. +/// The last element in .u.map must have .name = "" as the terminator. +/// +/// (3) Otherwise the string is treated as a non-negative unsigned decimal +/// integer which must be in the range set in .u.range. If .flags has +/// OPTMAP_USE_BYTE_SUFFIX then KiB, MiB, and GiB suffixes are allowed. +/// +/// The integer value from (2) or (3) is then stored to filter_options +/// at the offset specified in .offset using the type specified in .type +/// (default is uint32_t). +/// +/// Stringifying a filter is done by processing a given number of options +/// in oder from the beginning of an option_map array. The integer is +/// read from filter_options at .offset using the type from .type. +/// +/// If the integer is zero and .flags has OPTMAP_NO_STRFY_ZERO then the +/// option is skipped. +/// +/// If .flags has OPTMAP_USE_NAME_VALUE_MAP set then .u.map will be used +/// to convert the option to a string. If the map doesn't contain a string +/// for the integer value then "UNKNOWN" is used. +/// +/// If .flags doesn't have OPTMAP_USE_NAME_VALUE_MAP set then the integer is +/// converted to a decimal value. If OPTMAP_USE_BYTE_SUFFIX is used then KiB, +/// MiB, or GiB suffix is used if the value is an exact multiple of these. +/// Plain "B" suffix is never used. +typedef struct { + char name[NAME_LEN_MAX + 1]; + uint8_t type; + uint8_t flags; + uint16_t offset; + + union { + struct { + uint32_t min; + uint32_t max; + } range; + + const name_value_map *map; + } u; +} option_map; + + +static const char *parse_options(const char **const str, const char *str_end, + void *filter_options, + const option_map *const optmap, const size_t optmap_size); + + +///////// +// BCJ // +///////// + +static const option_map bcj_optmap[] = { + { + .name = "start", + .flags = OPTMAP_NO_STRFY_ZERO | OPTMAP_USE_BYTE_SUFFIX, + .offset = offsetof(lzma_options_bcj, start_offset), + .u.range.min = 0, + .u.range.max = UINT32_MAX, + } +}; + + +static const char * +parse_bcj(const char **const str, const char *str_end, void *filter_options) +{ + // filter_options was zeroed on allocation and that is enough + // for the default value. + return parse_options(str, str_end, filter_options, + bcj_optmap, ARRAY_SIZE(bcj_optmap)); +} + + +/////////// +// Delta // +/////////// + +#if defined(HAVE_ENCODER_DELTA) || defined(HAVE_DECODER_DELTA) +static const option_map delta_optmap[] = { + { + .name = "dist", + .offset = offsetof(lzma_options_delta, dist), + .u.range.min = LZMA_DELTA_DIST_MIN, + .u.range.max = LZMA_DELTA_DIST_MAX, + } +}; + + +static const char * +parse_delta(const char **const str, const char *str_end, void *filter_options) +{ + lzma_options_delta *opts = filter_options; + opts->type = LZMA_DELTA_TYPE_BYTE; + opts->dist = LZMA_DELTA_DIST_MIN; + + return parse_options(str, str_end, filter_options, + delta_optmap, ARRAY_SIZE(delta_optmap)); +} +#endif + + +/////////////////// +// LZMA1 & LZMA2 // +/////////////////// + +/// Help string for presets +#define LZMA12_PRESET_STR "0-9[e]" + + +static const char * +parse_lzma12_preset(const char **const str, const char *str_end, + uint32_t *preset) +{ + assert(*str < str_end); + *preset = (uint32_t)(**str - '0'); + + // NOTE: Remember to update LZMA_PRESET_STR if this is modified! + while (++*str < str_end) { + switch (**str) { + case 'e': + *preset |= LZMA_PRESET_EXTREME; + break; + + default: + return "Unsupported preset flag"; + } + } + + return NULL; +} + + +static const char * +set_lzma12_preset(const char **const str, const char *str_end, + void *filter_options) +{ + uint32_t preset; + const char *errmsg = parse_lzma12_preset(str, str_end, &preset); + if (errmsg != NULL) + return errmsg; + + lzma_options_lzma *opts = filter_options; + if (lzma_lzma_preset(opts, preset)) + return "Unsupported preset"; + + return NULL; +} + + +static const name_value_map lzma12_mode_map[] = { + { "fast", LZMA_MODE_FAST }, + { "normal", LZMA_MODE_NORMAL }, + { "", 0 } +}; + + +static const name_value_map lzma12_mf_map[] = { + { "hc3", LZMA_MF_HC3 }, + { "hc4", LZMA_MF_HC4 }, + { "bt2", LZMA_MF_BT2 }, + { "bt3", LZMA_MF_BT3 }, + { "bt4", LZMA_MF_BT4 }, + { "", 0 } +}; + + +static const option_map lzma12_optmap[] = { + { + .name = "preset", + .type = OPTMAP_TYPE_LZMA_PRESET, + }, { + .name = "dict", + .flags = OPTMAP_USE_BYTE_SUFFIX, + .offset = offsetof(lzma_options_lzma, dict_size), + .u.range.min = LZMA_DICT_SIZE_MIN, + // FIXME? The max is really max for encoding but decoding + // would allow 4 GiB - 1 B. + .u.range.max = (UINT32_C(1) << 30) + (UINT32_C(1) << 29), + }, { + .name = "lc", + .offset = offsetof(lzma_options_lzma, lc), + .u.range.min = LZMA_LCLP_MIN, + .u.range.max = LZMA_LCLP_MAX, + }, { + .name = "lp", + .offset = offsetof(lzma_options_lzma, lp), + .u.range.min = LZMA_LCLP_MIN, + .u.range.max = LZMA_LCLP_MAX, + }, { + .name = "pb", + .offset = offsetof(lzma_options_lzma, pb), + .u.range.min = LZMA_PB_MIN, + .u.range.max = LZMA_PB_MAX, + }, { + .name = "mode", + .type = OPTMAP_TYPE_LZMA_MODE, + .flags = OPTMAP_USE_NAME_VALUE_MAP, + .offset = offsetof(lzma_options_lzma, mode), + .u.map = lzma12_mode_map, + }, { + .name = "nice", + .offset = offsetof(lzma_options_lzma, nice_len), + .u.range.min = 2, + .u.range.max = 273, + }, { + .name = "mf", + .type = OPTMAP_TYPE_LZMA_MATCH_FINDER, + .flags = OPTMAP_USE_NAME_VALUE_MAP, + .offset = offsetof(lzma_options_lzma, mf), + .u.map = lzma12_mf_map, + }, { + .name = "depth", + .offset = offsetof(lzma_options_lzma, depth), + .u.range.min = 0, + .u.range.max = UINT32_MAX, + } +}; + + +static const char * +parse_lzma12(const char **const str, const char *str_end, void *filter_options) +{ + lzma_options_lzma *opts = filter_options; + + // It cannot fail. + const bool preset_ret = lzma_lzma_preset(opts, LZMA_PRESET_DEFAULT); + assert(!preset_ret); + (void)preset_ret; + + const char *errmsg = parse_options(str, str_end, filter_options, + lzma12_optmap, ARRAY_SIZE(lzma12_optmap)); + if (errmsg != NULL) + return errmsg; + + if (opts->lc + opts->lp > LZMA_LCLP_MAX) + return "The sum of lc and lp must not exceed 4"; + + return NULL; +} + + +///////////////////////////////////////// +// Generic parsing and stringification // +///////////////////////////////////////// + +static const struct { + /// Name of the filter + char name[NAME_LEN_MAX + 1]; + + /// For lzma_str_to_filters: + /// Size of the filter-specific options structure. + uint32_t opts_size; + + /// Filter ID + lzma_vli id; + + /// For lzma_str_to_filters: + /// Function to parse the filter-specific options. The filter_options + /// will already have been allocated using lzma_alloc_zero(). + const char *(*parse)(const char **str, const char *str_end, + void *filter_options); + + /// For lzma_str_from_filters: + /// If the flag LZMA_STR_ENCODER is used then the first + /// strfy_encoder elements of optmap are stringified. + /// With LZMA_STR_DECODER strfy_decoder is used. + /// Currently encoders use all flags that decoders do but if + /// that changes then this needs to be changed too, for example, + /// add a new OPTMAP flag to skip printing some decoder-only flags. + const option_map *optmap; + uint8_t strfy_encoder; + uint8_t strfy_decoder; + + /// For lzma_str_from_filters: + /// If true, lzma_filter.options is allowed to be NULL. In that case, + /// only the filter name is printed without any options. + bool allow_null; + +} filter_name_map[] = { +#if defined (HAVE_ENCODER_LZMA1) || defined(HAVE_DECODER_LZMA1) + { "lzma1", sizeof(lzma_options_lzma), LZMA_FILTER_LZMA1, + &parse_lzma12, lzma12_optmap, 9, 5, false }, +#endif + +#if defined(HAVE_ENCODER_LZMA2) || defined(HAVE_DECODER_LZMA2) + { "lzma2", sizeof(lzma_options_lzma), LZMA_FILTER_LZMA2, + &parse_lzma12, lzma12_optmap, 9, 2, false }, +#endif + +#if defined(HAVE_ENCODER_X86) || defined(HAVE_DECODER_X86) + { "x86", sizeof(lzma_options_bcj), LZMA_FILTER_X86, + &parse_bcj, bcj_optmap, 1, 1, true }, +#endif + +#if defined(HAVE_ENCODER_ARM) || defined(HAVE_DECODER_ARM) + { "arm", sizeof(lzma_options_bcj), LZMA_FILTER_ARM, + &parse_bcj, bcj_optmap, 1, 1, true }, +#endif + +#if defined(HAVE_ENCODER_ARMTHUMB) || defined(HAVE_DECODER_ARMTHUMB) + { "armthumb", sizeof(lzma_options_bcj), LZMA_FILTER_ARMTHUMB, + &parse_bcj, bcj_optmap, 1, 1, true }, +#endif + +#if defined(HAVE_ENCODER_ARM64) || defined(HAVE_DECODER_ARM64) + { "arm64", sizeof(lzma_options_bcj), LZMA_FILTER_ARM64, + &parse_bcj, bcj_optmap, 1, 1, true }, +#endif + +#if defined(HAVE_ENCODER_POWERPC) || defined(HAVE_DECODER_POWERPC) + { "powerpc", sizeof(lzma_options_bcj), LZMA_FILTER_POWERPC, + &parse_bcj, bcj_optmap, 1, 1, true }, +#endif + +#if defined(HAVE_ENCODER_IA64) || defined(HAVE_DECODER_IA64) + { "ia64", sizeof(lzma_options_bcj), LZMA_FILTER_IA64, + &parse_bcj, bcj_optmap, 1, 1, true }, +#endif + +#if defined(HAVE_ENCODER_SPARC) || defined(HAVE_DECODER_SPARC) + { "sparc", sizeof(lzma_options_bcj), LZMA_FILTER_SPARC, + &parse_bcj, bcj_optmap, 1, 1, true }, +#endif + +#if defined(HAVE_ENCODER_DELTA) || defined(HAVE_DECODER_DELTA) + { "delta", sizeof(lzma_options_delta), LZMA_FILTER_DELTA, + &parse_delta, delta_optmap, 1, 1, false }, +#endif +}; + + +/// Decodes options from a string for one filter (name1=value1,name2=value2). +/// Caller must have allocated memory for filter_options already and set +/// the initial default values. This is called from the filter-specific +/// parse_* functions. +/// +/// The input string starts at *str and the address in str_end is the first +/// char that is not part of the string anymore. So no '\0' terminator is +/// used. *str is advanced everytime something has been decoded successfully. +static const char * +parse_options(const char **const str, const char *str_end, + void *filter_options, + const option_map *const optmap, const size_t optmap_size) +{ + while (*str < str_end && **str != '\0') { + // Each option is of the form name=value. + // Commas (',') separate options. Extra commas are ignored. + // Ignoring extra commas makes it simpler if an optional + // option stored in a shell variable which can be empty. + if (**str == ',') { + ++*str; + continue; + } + + // Find where the next name=value ends. + const size_t str_len = (size_t)(str_end - *str); + const char *name_eq_value_end = memchr(*str, ',', str_len); + if (name_eq_value_end == NULL) + name_eq_value_end = str_end; + + const char *equals_sign = memchr(*str, '=', + (size_t)(name_eq_value_end - *str)); + + // Fail if the '=' wasn't found or the option name is missing + // (the first char is '='). + if (equals_sign == NULL || **str == '=') + return "Options must be 'name=value' pairs separated " + "with commas"; + + // Reject a too long option name so that the memcmp() + // in the loop below won't read past the end of the + // string in optmap[i].name. + const size_t name_len = (size_t)(equals_sign - *str); + if (name_len > NAME_LEN_MAX) + return "Unknown option name"; + + // Find the option name from optmap[]. + size_t i = 0; + while (true) { + if (i == optmap_size) + return "Unknown option name"; + + if (memcmp(*str, optmap[i].name, name_len) == 0 + && optmap[i].name[name_len] == '\0') + break; + + ++i; + } + + // The input string is good at least until the start of + // the option value. + *str = equals_sign + 1; + + // The code assumes that the option value isn't an empty + // string so check it here. + const size_t value_len = (size_t)(name_eq_value_end - *str); + if (value_len == 0) + return "Option value cannot be empty"; + + // LZMA1/2 preset has its own parsing function. + if (optmap[i].type == OPTMAP_TYPE_LZMA_PRESET) { + const char *errmsg = set_lzma12_preset(str, + name_eq_value_end, filter_options); + if (errmsg != NULL) + return errmsg; + + continue; + } + + // It's an integer value. + uint32_t v; + if (optmap[i].flags & OPTMAP_USE_NAME_VALUE_MAP) { + // The integer is picked from a string-to-integer map. + // + // Reject a too long value string so that the memcmp() + // in the loop below won't read past the end of the + // string in optmap[i].u.map[j].name. + if (value_len > NAME_LEN_MAX) + return "Invalid option value"; + + const name_value_map *map = optmap[i].u.map; + size_t j = 0; + while (true) { + // The array is terminated with an empty name. + if (map[j].name[0] == '\0') + return "Invalid option value"; + + if (memcmp(*str, map[j].name, value_len) == 0 + && map[j].name[value_len] + == '\0') { + v = map[j].value; + break; + } + + ++j; + } + } else if (**str < '0' || **str > '9') { + // Note that "max" isn't supported while it is + // supported in xz. It's not useful here. + return "Value is not a non-negative decimal integer"; + } else { + // strtoul() has locale-specific behavior so it cannot + // be relied on to get reproducible results since we + // cannot change the locate in a thread-safe library. + // It also needs '\0'-termination. + // + // Use a temporary pointer so that *str will point + // to the beginning of the value string in case + // an error occurs. + const char *p = *str; + v = 0; + do { + if (v > UINT32_MAX / 10) + return "Value out of range"; + + v *= 10; + + const uint32_t add = (uint32_t)(*p - '0'); + if (UINT32_MAX - add < v) + return "Value out of range"; + + v += add; + ++p; + } while (p < name_eq_value_end + && *p >= '0' && *p <= '9'); + + if (p < name_eq_value_end) { + // Remember this position so that it an be + // used for error messages that are + // specifically about the suffix. (Out of + // range values are about the whole value + // and those error messages point to the + // beginning of the number part, + // not to the suffix.) + const char *multiplier_start = p; + + // If multiplier suffix shouldn't be used + // then don't allow them even if the value + // would stay within limits. This is a somewhat + // unnecessary check but it rejects silly + // things like lzma2:pb=0MiB which xz allows. + if ((optmap[i].flags & OPTMAP_USE_BYTE_SUFFIX) + == 0) { + *str = multiplier_start; + return "This option does not support " + "any integer suffixes"; + } + + uint32_t shift; + + switch (*p) { + case 'k': + case 'K': + shift = 10; + break; + + case 'm': + case 'M': + shift = 20; + break; + + case 'g': + case 'G': + shift = 30; + break; + + default: + *str = multiplier_start; + return "Invalid multiplier suffix " + "(KiB, MiB, or GiB)"; + } + + ++p; + + // Allow "M", "Mi", "MB", "MiB" and the same + // for the other five characters from the + // switch-statement above. All are handled + // as base-2 (perhaps a mistake, perhaps not). + // Note that 'i' and 'B' are case sensitive. + if (p < name_eq_value_end && *p == 'i') + ++p; + + if (p < name_eq_value_end && *p == 'B') + ++p; + + // Now we must have no chars remaining. + if (p < name_eq_value_end) { + *str = multiplier_start; + return "Invalid multiplier suffix " + "(KiB, MiB, or GiB)"; + } + + if (v > (UINT32_MAX >> shift)) + return "Value out of range"; + + v <<= shift; + } + + if (v < optmap[i].u.range.min + || v > optmap[i].u.range.max) + return "Value out of range"; + } + + // Set the value in filter_options. Enums are handled + // specially since the underlying type isn't the same + // as uint32_t on all systems. + void *ptr = (char *)filter_options + optmap[i].offset; + switch (optmap[i].type) { + case OPTMAP_TYPE_LZMA_MODE: + *(lzma_mode *)ptr = (lzma_mode)v; + break; + + case OPTMAP_TYPE_LZMA_MATCH_FINDER: + *(lzma_match_finder *)ptr = (lzma_match_finder)v; + break; + + default: + *(uint32_t *)ptr = v; + break; + } + + // This option has been successfully handled. + *str = name_eq_value_end; + } + + // No errors. + return NULL; +} + + +/// Finds the name of the filter at the beginning of the string and +/// calls filter_name_map[i].parse() to decode the filter-specific options. +/// The caller must have set str_end so that exactly one filter and its +/// options are present without any trailing characters. +static const char * +parse_filter(const char **const str, const char *str_end, lzma_filter *filter, + const lzma_allocator *allocator, bool only_xz) +{ + // Search for a colon or equals sign that would separate the filter + // name from filter options. If neither is found, then the input + // string only contains a filter name and there are no options. + // + // First assume that a colon or equals sign won't be found: + const char *name_end = str_end; + const char *opts_start = str_end; + + for (const char *p = *str; p < str_end; ++p) { + if (*p == ':' || *p == '=') { + name_end = p; + + // Filter options (name1=value1,name2=value2,...) + // begin after the colon or equals sign. + opts_start = p + 1; + break; + } + } + + // Reject a too long filter name so that the memcmp() + // in the loop below won't read past the end of the + // string in filter_name_map[i].name. + const size_t name_len = (size_t)(name_end - *str); + if (name_len > NAME_LEN_MAX) + return "Unknown filter name"; + + for (size_t i = 0; i < ARRAY_SIZE(filter_name_map); ++i) { + if (memcmp(*str, filter_name_map[i].name, name_len) == 0 + && filter_name_map[i].name[name_len] == '\0') { + if (only_xz && filter_name_map[i].id + >= LZMA_FILTER_RESERVED_START) + return "This filter cannot be used in " + "the .xz format"; + + // Allocate the filter-specific options and + // initialize the memory with zeros. + void *options = lzma_alloc_zero( + filter_name_map[i].opts_size, + allocator); + if (options == NULL) + return "Memory allocation failed"; + + // Filter name was found so the input string is good + // at least this far. + *str = opts_start; + + const char *errmsg = filter_name_map[i].parse( + str, str_end, options); + if (errmsg != NULL) { + lzma_free(options, allocator); + return errmsg; + } + + // *filter is modified only when parsing is successful. + filter->id = filter_name_map[i].id; + filter->options = options; + return NULL; + } + } + + return "Unknown filter name"; +} + + +/// Converts the string to a filter chain (array of lzma_filter structures). +/// +/// *str is advanced everytime something has been decoded successfully. +/// This way the caller knows where in the string a possible error occurred. +static const char * +str_to_filters(const char **const str, lzma_filter *filters, uint32_t flags, + const lzma_allocator *allocator) +{ + const char *errmsg; + + // Skip leading spaces. + while (**str == ' ') + ++*str; + + if (**str == '\0') + return "Empty string is not allowed, " + "try \"6\" if a default value is needed"; + + // Detect the type of the string. + // + // A string beginning with a digit or a string beginning with + // one dash and a digit are treated as presets. Trailing spaces + // will be ignored too (leading spaces were already ignored above). + // + // For example, "6", "7 ", "-9e", or " -3 " are treated as presets. + // Strings like "-" or "- " aren't preset. +#define MY_IS_DIGIT(c) ((c) >= '0' && (c) <= '9') + if (MY_IS_DIGIT(**str) || (**str == '-' && MY_IS_DIGIT((*str)[1]))) { + if (**str == '-') + ++*str; + + // Ignore trailing spaces. + const size_t str_len = strlen(*str); + const char *str_end = memchr(*str, ' ', str_len); + if (str_end != NULL) { + // There is at least one trailing space. Check that + // there are no chars other than spaces. + for (size_t i = 1; str_end[i] != '\0'; ++i) + if (str_end[i] != ' ') + return "Unsupported preset"; + } else { + // There are no trailing spaces. Use the whole string. + str_end = *str + str_len; + } + + uint32_t preset; + errmsg = parse_lzma12_preset(str, str_end, &preset); + if (errmsg != NULL) + return errmsg; + + lzma_options_lzma *opts = lzma_alloc(sizeof(*opts), allocator); + if (opts == NULL) + return "Memory allocation failed"; + + if (lzma_lzma_preset(opts, preset)) { + lzma_free(opts, allocator); + return "Unsupported preset"; + } + + filters[0].id = LZMA_FILTER_LZMA2; + filters[0].options = opts; + filters[1].id = LZMA_VLI_UNKNOWN; + filters[1].options = NULL; + + return NULL; + } + + // Not a preset so it must be a filter chain. + // + // If LZMA_STR_ALL_FILTERS isn't used we allow only filters that + // can be used in .xz. + const bool only_xz = (flags & LZMA_STR_ALL_FILTERS) == 0; + + // Use a temporary array so that we don't modify the caller-supplied + // one until we know that no errors occurred. + lzma_filter temp_filters[LZMA_FILTERS_MAX + 1]; + + size_t i = 0; + do { + if (i == LZMA_FILTERS_MAX) { + errmsg = "The maximum number of filters is four"; + goto error; + } + + // Skip "--" if present. + if ((*str)[0] == '-' && (*str)[1] == '-') + *str += 2; + + // Locate the end of "filter:name1=value1,name2=value2", + // stopping at the first "--" or a single space. + const char *filter_end = *str; + while (filter_end[0] != '\0') { + if ((filter_end[0] == '-' && filter_end[1] == '-') + || filter_end[0] == ' ') + break; + + ++filter_end; + } + + // Inputs that have "--" at the end or "-- " in the middle + // will result in an empty filter name. + if (filter_end == *str) { + errmsg = "Filter name is missing"; + goto error; + } + + errmsg = parse_filter(str, filter_end, &temp_filters[i], + allocator, only_xz); + if (errmsg != NULL) + goto error; + + // Skip trailing spaces. + while (**str == ' ') + ++*str; + + ++i; + } while (**str != '\0'); + + // Seems to be good, terminate the array so that + // basic validation can be done. + temp_filters[i].id = LZMA_VLI_UNKNOWN; + temp_filters[i].options = NULL; + + // Do basic validation if the application didn't prohibit it. + if ((flags & LZMA_STR_NO_VALIDATION) == 0) { + size_t dummy; + const lzma_ret ret = lzma_validate_chain(temp_filters, &dummy); + assert(ret == LZMA_OK || ret == LZMA_OPTIONS_ERROR); + if (ret != LZMA_OK) { + errmsg = "Invalid filter chain " + "('lzma2' missing at the end?)"; + goto error; + } + } + + // All good. Copy the filters to the application supplied array. + memcpy(filters, temp_filters, (i + 1) * sizeof(lzma_filter)); + return NULL; + +error: + // Free the filter options that were successfully decoded. + while (i-- > 0) + lzma_free(temp_filters[i].options, allocator); + + return errmsg; +} + + +extern LZMA_API(const char *) +lzma_str_to_filters(const char *str, int *error_pos, lzma_filter *filters, + uint32_t flags, const lzma_allocator *allocator) +{ + if (str == NULL || filters == NULL) + return "Unexpected NULL pointer argument(s) " + "to lzma_str_to_filters()"; + + // Validate the flags. + const uint32_t supported_flags + = LZMA_STR_ALL_FILTERS + | LZMA_STR_NO_VALIDATION; + + if (flags & ~supported_flags) + return "Unsupported flags to lzma_str_to_filters()"; + + const char *used = str; + const char *errmsg = str_to_filters(&used, filters, flags, allocator); + + if (error_pos != NULL) { + const size_t n = (size_t)(used - str); + *error_pos = n > INT_MAX ? INT_MAX : (int)n; + } + + return errmsg; +} + + +/// Converts options of one filter to a string. +/// +/// The caller must have already put the filter name in the destination +/// string. Since it is possible that no options will be needed, the caller +/// won't have put a delimiter character (':' or '=') in the string yet. +/// We will add it if at least one option will be added to the string. +static void +strfy_filter(lzma_str *dest, const char *delimiter, + const option_map *optmap, size_t optmap_count, + const void *filter_options) +{ + for (size_t i = 0; i < optmap_count; ++i) { + // No attempt is made to reverse LZMA1/2 preset. + if (optmap[i].type == OPTMAP_TYPE_LZMA_PRESET) + continue; + + // All options have integer values, some just are mapped + // to a string with a name_value_map. LZMA1/2 preset + // isn't reversed back to preset=PRESET form. + uint32_t v; + const void *ptr + = (const char *)filter_options + optmap[i].offset; + switch (optmap[i].type) { + case OPTMAP_TYPE_LZMA_MODE: + v = *(const lzma_mode *)ptr; + break; + + case OPTMAP_TYPE_LZMA_MATCH_FINDER: + v = *(const lzma_match_finder *)ptr; + break; + + default: + v = *(const uint32_t *)ptr; + break; + } + + // Skip this if this option should be omitted from + // the string when the value is zero. + if (v == 0 && (optmap[i].flags & OPTMAP_NO_STRFY_ZERO)) + continue; + + // Before the first option we add whatever delimiter + // the caller gave us. For later options a comma is used. + str_append_str(dest, delimiter); + delimiter = ","; + + // Add the option name and equals sign. + str_append_str(dest, optmap[i].name); + str_append_str(dest, "="); + + if (optmap[i].flags & OPTMAP_USE_NAME_VALUE_MAP) { + const name_value_map *map = optmap[i].u.map; + size_t j = 0; + while (true) { + if (map[j].name[0] == '\0') { + str_append_str(dest, "UNKNOWN"); + break; + } + + if (map[j].value == v) { + str_append_str(dest, map[j].name); + break; + } + + ++j; + } + } else { + str_append_u32(dest, v, + optmap[i].flags & OPTMAP_USE_BYTE_SUFFIX); + } + } + + return; +} + + +extern LZMA_API(lzma_ret) +lzma_str_from_filters(char **output_str, const lzma_filter *filters, + uint32_t flags, const lzma_allocator *allocator) +{ + // On error *output_str is always set to NULL. + // Do it as the very first step. + if (output_str == NULL) + return LZMA_PROG_ERROR; + + *output_str = NULL; + + if (filters == NULL) + return LZMA_PROG_ERROR; + + // Validate the flags. + const uint32_t supported_flags + = LZMA_STR_ENCODER + | LZMA_STR_DECODER + | LZMA_STR_GETOPT_LONG + | LZMA_STR_NO_SPACES; + + if (flags & ~supported_flags) + return LZMA_OPTIONS_ERROR; + + // There must be at least one filter. + if (filters[0].id == LZMA_VLI_UNKNOWN) + return LZMA_OPTIONS_ERROR; + + // Allocate memory for the output string. + lzma_str dest; + return_if_error(str_init(&dest, allocator)); + + const bool show_opts = (flags & (LZMA_STR_ENCODER | LZMA_STR_DECODER)); + + const char *opt_delim = (flags & LZMA_STR_GETOPT_LONG) ? "=" : ":"; + + for (size_t i = 0; filters[i].id != LZMA_VLI_UNKNOWN; ++i) { + // Don't add a space between filters if the caller + // doesn't want them. + if (i > 0 && !(flags & LZMA_STR_NO_SPACES)) + str_append_str(&dest, " "); + + // Use dashes for xz getopt_long() compatible syntax but also + // use dashes to separate filters when spaces weren't wanted. + if ((flags & LZMA_STR_GETOPT_LONG) + || (i > 0 && (flags & LZMA_STR_NO_SPACES))) + str_append_str(&dest, "--"); + + size_t j = 0; + while (true) { + if (j == ARRAY_SIZE(filter_name_map)) { + // Filter ID in filters[i].id isn't supported. + str_free(&dest, allocator); + return LZMA_OPTIONS_ERROR; + } + + if (filter_name_map[j].id == filters[i].id) { + // Add the filter name. + str_append_str(&dest, filter_name_map[j].name); + + // If only the filter names were wanted then + // skip to the next filter. In this case + // .options is ignored and may be NULL even + // when the filter doesn't allow NULL options. + if (!show_opts) + break; + + if (filters[i].options == NULL) { + if (!filter_name_map[j].allow_null) { + // Filter-specific options + // are missing but with + // this filter the options + // structure is mandatory. + str_free(&dest, allocator); + return LZMA_OPTIONS_ERROR; + } + + // .options is allowed to be NULL. + // There is no need to add any + // options to the string. + break; + } + + // Options structure is available. Add + // the filter options to the string. + const size_t optmap_count + = (flags & LZMA_STR_ENCODER) + ? filter_name_map[j].strfy_encoder + : filter_name_map[j].strfy_decoder; + strfy_filter(&dest, opt_delim, + filter_name_map[j].optmap, + optmap_count, + filters[i].options); + break; + } + + ++j; + } + } + + return str_finish(output_str, &dest, allocator); +} + + +extern LZMA_API(lzma_ret) +lzma_str_list_filters(char **output_str, lzma_vli filter_id, uint32_t flags, + const lzma_allocator *allocator) +{ + // On error *output_str is always set to NULL. + // Do it as the very first step. + if (output_str == NULL) + return LZMA_PROG_ERROR; + + *output_str = NULL; + + // Validate the flags. + const uint32_t supported_flags + = LZMA_STR_ALL_FILTERS + | LZMA_STR_ENCODER + | LZMA_STR_DECODER + | LZMA_STR_GETOPT_LONG; + + if (flags & ~supported_flags) + return LZMA_OPTIONS_ERROR; + + // Allocate memory for the output string. + lzma_str dest; + return_if_error(str_init(&dest, allocator)); + + // If only listing the filter names then separate them with spaces. + // Otherwise use newlines. + const bool show_opts = (flags & (LZMA_STR_ENCODER | LZMA_STR_DECODER)); + const char *filter_delim = show_opts ? "\n" : " "; + + const char *opt_delim = (flags & LZMA_STR_GETOPT_LONG) ? "=" : ":"; + bool first_filter_printed = false; + + for (size_t i = 0; i < ARRAY_SIZE(filter_name_map); ++i) { + // If we are printing only one filter then skip others. + if (filter_id != LZMA_VLI_UNKNOWN + && filter_id != filter_name_map[i].id) + continue; + + // If we are printing only .xz filters then skip the others. + if (filter_name_map[i].id >= LZMA_FILTER_RESERVED_START + && (flags & LZMA_STR_ALL_FILTERS) == 0 + && filter_id == LZMA_VLI_UNKNOWN) + continue; + + // Add a new line if this isn't the first filter being + // written to the string. + if (first_filter_printed) + str_append_str(&dest, filter_delim); + + first_filter_printed = true; + + if (flags & LZMA_STR_GETOPT_LONG) + str_append_str(&dest, "--"); + + str_append_str(&dest, filter_name_map[i].name); + + // If only the filter names were wanted then continue + // to the next filter. + if (!show_opts) + continue; + + const option_map *optmap = filter_name_map[i].optmap; + const char *d = opt_delim; + + const size_t end = (flags & LZMA_STR_ENCODER) + ? filter_name_map[i].strfy_encoder + : filter_name_map[i].strfy_decoder; + + for (size_t j = 0; j < end; ++j) { + // The first option is delimited from the filter + // name using "=" or ":" and the rest of the options + // are separated with ",". + str_append_str(&dest, d); + d = ","; + + // optname=<possible_values> + str_append_str(&dest, optmap[j].name); + str_append_str(&dest, "=<"); + + if (optmap[j].type == OPTMAP_TYPE_LZMA_PRESET) { + // LZMA1/2 preset has its custom help string. + str_append_str(&dest, LZMA12_PRESET_STR); + } else if (optmap[j].flags + & OPTMAP_USE_NAME_VALUE_MAP) { + // Separate the possible option values by "|". + const name_value_map *m = optmap[j].u.map; + for (size_t k = 0; m[k].name[0] != '\0'; ++k) { + if (k > 0) + str_append_str(&dest, "|"); + + str_append_str(&dest, m[k].name); + } + } else { + // Integer range is shown as min-max. + const bool use_byte_suffix = optmap[j].flags + & OPTMAP_USE_BYTE_SUFFIX; + str_append_u32(&dest, optmap[j].u.range.min, + use_byte_suffix); + str_append_str(&dest, "-"); + str_append_u32(&dest, optmap[j].u.range.max, + use_byte_suffix); + } + + str_append_str(&dest, ">"); + } + } + + // If no filters were added to the string then it must be because + // the caller provided an unsupported Filter ID. + if (!first_filter_printed) { + str_free(&dest, allocator); + return LZMA_OPTIONS_ERROR; + } + + return str_finish(output_str, &dest, allocator); +} |