journal: Move more pattern matching logic into pcre2-util
To avoid having "#if HAVE_PCRE2" all throughout the code, let's confine the pcre2 header specific stuff to pcre2-util.c. Instead of exposing all the individual symbols from pcre2, let's only expose three high level functions that do all we need: - pcre2_pattern_compile(): Compile the regex - pcre2_pattern_matches(): Check if the compiled regex matches a message - pcre2_pattern_free(): Free the compiled regex We expose the compiled pcre2 pattern (which is of type pcre2_code *) as a void pointer to avoid having to include pcre2.h in all code where we work with compiled pcre2 patterns. For readability, we typedef void to pcre2_pattern and use that as the type specifier for compiled pcre2 patterns.
This commit is contained in:
Daan De Meyer
+120
-7
@@ -14,8 +14,10 @@ pcre2_code* (*sym_pcre2_compile)(PCRE2_SPTR, PCRE2_SIZE, uint32_t, int *, PCRE2_
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int (*sym_pcre2_get_error_message)(int, PCRE2_UCHAR *, PCRE2_SIZE);
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int (*sym_pcre2_match)(const pcre2_code *, PCRE2_SPTR, PCRE2_SIZE, PCRE2_SIZE, uint32_t, pcre2_match_data *, pcre2_match_context *);
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PCRE2_SIZE* (*sym_pcre2_get_ovector_pointer)(pcre2_match_data *);
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#endif
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int dlopen_pcre2(void) {
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#if HAVE_PCRE2
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/* So here's something weird: PCRE2 actually renames the symbols exported by the library via C
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* macros, so that the exported symbols carry a suffix "_8" but when used from C the suffix is
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* gone. In the argument list below we ignore this mangling. Surprisingly (at least to me), we
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@@ -33,12 +35,123 @@ int dlopen_pcre2(void) {
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DLSYM_ARG(pcre2_get_error_message),
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DLSYM_ARG(pcre2_match),
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DLSYM_ARG(pcre2_get_ovector_pointer));
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}
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#else
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int dlopen_pcre2(void) {
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return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
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"PCRE2 support is not compiled in.");
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}
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return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "PCRE2 support is not compiled in.");
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#endif
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}
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int pattern_compile_and_log(const char *pattern, PatternCompileCase case_, pcre2_code **ret) {
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#if HAVE_PCRE2
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PCRE2_SIZE erroroffset;
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pcre2_code *p;
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unsigned flags = 0;
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int errorcode, r;
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assert(pattern);
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r = dlopen_pcre2();
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if (r < 0)
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return r;
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if (case_ == PATTERN_COMPILE_CASE_INSENSITIVE)
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flags = PCRE2_CASELESS;
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else if (case_ == PATTERN_COMPILE_CASE_AUTO) {
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_cleanup_(sym_pcre2_match_data_freep) pcre2_match_data *md = NULL;
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bool has_case;
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_cleanup_(sym_pcre2_code_freep) pcre2_code *cs = NULL;
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md = sym_pcre2_match_data_create(1, NULL);
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if (!md)
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return log_oom();
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r = pattern_compile_and_log("[[:upper:]]", PATTERN_COMPILE_CASE_SENSITIVE, &cs);
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if (r < 0)
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return r;
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r = sym_pcre2_match(cs, (PCRE2_SPTR8) pattern, PCRE2_ZERO_TERMINATED, 0, 0, md, NULL);
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has_case = r >= 0;
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flags = !has_case * PCRE2_CASELESS;
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}
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log_debug("Doing case %s matching based on %s",
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flags & PCRE2_CASELESS ? "insensitive" : "sensitive",
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case_ != PATTERN_COMPILE_CASE_AUTO ? "request" : "pattern casing");
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p = sym_pcre2_compile((PCRE2_SPTR8) pattern,
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PCRE2_ZERO_TERMINATED, flags, &errorcode, &erroroffset, NULL);
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if (!p) {
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unsigned char buf[LINE_MAX];
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r = sym_pcre2_get_error_message(errorcode, buf, sizeof buf);
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return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
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"Bad pattern \"%s\": %s", pattern,
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r < 0 ? "unknown error" : (char *)buf);
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}
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if (ret)
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*ret = p;
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return 0;
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#else
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return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "PCRE2 support is not compiled in.");
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#endif
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}
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int pattern_matches_and_log(pcre2_code *compiled_pattern, const char *message, size_t size, size_t *ret_ovec) {
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#if HAVE_PCRE2
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_cleanup_(sym_pcre2_match_data_freep) pcre2_match_data *md = NULL;
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int r;
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assert(compiled_pattern);
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assert(message);
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/* pattern_compile_and_log() must be called before this function is called and that function already
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* dlopens pcre2 so we can assert on it being available here. */
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assert(pcre2_dl);
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md = sym_pcre2_match_data_create(1, NULL);
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if (!md)
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return log_oom();
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r = sym_pcre2_match(compiled_pattern,
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(const unsigned char *)message,
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size,
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0, /* start at offset 0 in the subject */
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0, /* default options */
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md,
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NULL);
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if (r == PCRE2_ERROR_NOMATCH)
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return false;
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if (r < 0) {
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unsigned char buf[LINE_MAX];
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r = sym_pcre2_get_error_message(r, buf, sizeof(buf));
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return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Pattern matching failed: %s",
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r < 0 ? "unknown error" : (char*) buf);
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}
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if (ret_ovec) {
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ret_ovec[0] = sym_pcre2_get_ovector_pointer(md)[0];
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ret_ovec[1] = sym_pcre2_get_ovector_pointer(md)[1];
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}
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return true;
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#else
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return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "PCRE2 support is not compiled in.");
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#endif
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}
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void *pattern_free(pcre2_code *p) {
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#if HAVE_PCRE2
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if (!p)
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return NULL;
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assert(pcre2_dl);
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sym_pcre2_code_free(p);
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return NULL;
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#else
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assert(p == NULL);
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return NULL;
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#endif
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}
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@@ -18,6 +18,24 @@ extern PCRE2_SIZE* (*sym_pcre2_get_ovector_pointer)(pcre2_match_data *);
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DEFINE_TRIVIAL_CLEANUP_FUNC_FULL(pcre2_match_data*, sym_pcre2_match_data_free, NULL);
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DEFINE_TRIVIAL_CLEANUP_FUNC_FULL(pcre2_code*, sym_pcre2_code_free, NULL);
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#else
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typedef struct {} pcre2_code;
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#endif
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typedef enum {
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PATTERN_COMPILE_CASE_AUTO,
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PATTERN_COMPILE_CASE_SENSITIVE,
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PATTERN_COMPILE_CASE_INSENSITIVE,
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_PATTERN_COMPILE_CASE_MAX,
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_PATTERN_COMPILE_CASE_INVALID = -EINVAL,
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} PatternCompileCase;
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int pattern_compile_and_log(const char *pattern, PatternCompileCase case_, pcre2_code **ret);
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int pattern_matches_and_log(pcre2_code *compiled_pattern, const char *message, size_t size, size_t *ret_ovec);
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void *pattern_free(pcre2_code *p);
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DEFINE_TRIVIAL_CLEANUP_FUNC(pcre2_code*, pattern_free);
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int dlopen_pcre2(void);
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