/* Search text engine. HEX-style pattern matching Copyright (C) 2009-2021 Free Software Foundation, Inc. Written by: Slava Zanko , 2009. This file is part of the Midnight Commander. The Midnight Commander is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. The Midnight Commander is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . */ #include #include #include "lib/global.h" #include "lib/strutil.h" #include "lib/search.h" #include "lib/strescape.h" #include "internal.h" /*** global variables ****************************************************************************/ /*** file scope macro definitions ****************************************************************/ typedef enum { MC_SEARCH_HEX_E_OK, MC_SEARCH_HEX_E_NUM_OUT_OF_RANGE, MC_SEARCH_HEX_E_INVALID_CHARACTER, MC_SEARCH_HEX_E_UNMATCHED_QUOTES } mc_search_hex_parse_error_t; /*** file scope type declarations ****************************************************************/ /*** file scope variables ************************************************************************/ /*** file scope functions ************************************************************************/ static GString * mc_search__hex_translate_to_regex (const GString * astr, mc_search_hex_parse_error_t * error_ptr, int *error_pos_ptr) { GString *buff; const char *str; gsize str_len; gsize loop = 0; mc_search_hex_parse_error_t error = MC_SEARCH_HEX_E_OK; buff = g_string_sized_new (64); str = astr->str; str_len = astr->len; while (loop < str_len && error == MC_SEARCH_HEX_E_OK) { unsigned int val; int ptr; if (g_ascii_isspace (str[loop])) { /* Eat-up whitespace between tokens. */ while (g_ascii_isspace (str[loop])) loop++; } /* cppcheck-suppress invalidscanf */ else if (sscanf (str + loop, "%x%n", &val, &ptr) == 1) { if (val > 255) error = MC_SEARCH_HEX_E_NUM_OUT_OF_RANGE; else { g_string_append_printf (buff, "\\x%02X", val); loop += ptr; } } else if (str[loop] == '"') { gsize loop2; loop2 = loop + 1; while (loop2 < str_len) { if (str[loop2] == '"') break; if (str[loop2] == '\\' && loop2 + 1 < str_len) loop2++; g_string_append_c (buff, str[loop2]); loop2++; } if (str[loop2] == '\0') error = MC_SEARCH_HEX_E_UNMATCHED_QUOTES; else loop = loop2 + 1; } else error = MC_SEARCH_HEX_E_INVALID_CHARACTER; } if (error != MC_SEARCH_HEX_E_OK) { g_string_free (buff, TRUE); if (error_ptr != NULL) *error_ptr = error; if (error_pos_ptr != NULL) *error_pos_ptr = loop; return NULL; } return buff; } /*** public functions ****************************************************************************/ void mc_search__cond_struct_new_init_hex (const char *charset, mc_search_t * lc_mc_search, mc_search_cond_t * mc_search_cond) { GString *tmp; mc_search_hex_parse_error_t error = MC_SEARCH_HEX_E_OK; int error_pos = 0; /* * We may be searching in binary data, which is often invalid UTF-8. * * We have to create a non UTF-8 regex (that is, G_REGEX_RAW) or else, as * the data is invalid UTF-8, both GLib's PCRE and our * mc_search__g_regex_match_full_safe() are going to fail us. The former by * not finding all bytes, the latter by overwriting the supposedly invalid * UTF-8 with NULs. * * To do this, we specify "ASCII" as the charset. * * In fact, we can specify any charset other than "UTF-8": any such charset * will trigger G_REGEX_RAW (see [1]). The output of [2] will be the same * for all charsets because it skips the \xXX symbols * mc_search__hex_translate_to_regex() outputs. * * But "ASCII" is the best choice because a hex pattern may contain a * quoted string: this way we know [2] will ignore any characters outside * ASCII letters range (these ignored chars will be copied verbatim to the * output and will match as-is; in other words, in a case-sensitive manner; * If the user is interested in case-insensitive searches of international * text, he shouldn't be using hex search in the first place.) * * Switching out of UTF-8 has another advantage: * * When doing case-insensitive searches, GLib treats \xXX symbols as normal * letters and therefore matches both "a" and "A" for the hex pattern * "0x61". When we switch out of UTF-8, we're switching to using [2], which * doesn't have this issue. * * [1] mc_search__cond_struct_new_init_regex * [2] mc_search__cond_struct_new_regex_ci_str */ if (str_isutf8 (charset)) charset = "ASCII"; tmp = mc_search__hex_translate_to_regex (mc_search_cond->str, &error, &error_pos); if (tmp != NULL) { g_string_free (mc_search_cond->str, TRUE); mc_search_cond->str = tmp; mc_search__cond_struct_new_init_regex (charset, lc_mc_search, mc_search_cond); } else { const char *desc; switch (error) { case MC_SEARCH_HEX_E_NUM_OUT_OF_RANGE: desc = _ ("Number out of range (should be in byte range, 0 <= n <= 0xFF, expressed in hex)"); break; case MC_SEARCH_HEX_E_INVALID_CHARACTER: desc = _("Invalid character"); break; case MC_SEARCH_HEX_E_UNMATCHED_QUOTES: desc = _("Unmatched quotes character"); break; default: desc = ""; } lc_mc_search->error = MC_SEARCH_E_INPUT; lc_mc_search->error_str = g_strdup_printf (_("Hex pattern error at position %d:\n%s."), error_pos + 1, desc); } } /* --------------------------------------------------------------------------------------------- */ gboolean mc_search__run_hex (mc_search_t * lc_mc_search, const void *user_data, gsize start_search, gsize end_search, gsize * found_len) { return mc_search__run_regex (lc_mc_search, user_data, start_search, end_search, found_len); } /* --------------------------------------------------------------------------------------------- */ GString * mc_search_hex_prepare_replace_str (mc_search_t * lc_mc_search, GString * replace_str) { (void) lc_mc_search; return mc_g_string_dup (replace_str); } /* --------------------------------------------------------------------------------------------- */