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-rw-r--r--libnetdata/simple_pattern/simple_pattern.c365
1 files changed, 365 insertions, 0 deletions
diff --git a/libnetdata/simple_pattern/simple_pattern.c b/libnetdata/simple_pattern/simple_pattern.c
new file mode 100644
index 0000000..70b06a2
--- /dev/null
+++ b/libnetdata/simple_pattern/simple_pattern.c
@@ -0,0 +1,365 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "../libnetdata.h"
+
+struct simple_pattern {
+ const char *match;
+ size_t len;
+
+ SIMPLE_PREFIX_MODE mode;
+ char negative;
+
+ struct simple_pattern *child;
+
+ struct simple_pattern *next;
+};
+
+static inline struct simple_pattern *parse_pattern(char *str, SIMPLE_PREFIX_MODE default_mode) {
+ // fprintf(stderr, "PARSING PATTERN: '%s'\n", str);
+
+ SIMPLE_PREFIX_MODE mode;
+ struct simple_pattern *child = NULL;
+
+ char *s = str, *c = str;
+
+ // skip asterisks in front
+ while(*c == '*') c++;
+
+ // find the next asterisk
+ while(*c && *c != '*') c++;
+
+ // do we have an asterisk in the middle?
+ if(*c == '*' && c[1] != '\0') {
+ // yes, we have
+ child = parse_pattern(c, default_mode);
+ c[1] = '\0';
+ }
+
+ // check what this one matches
+
+ size_t len = strlen(s);
+ if(len >= 2 && *s == '*' && s[len - 1] == '*') {
+ s[len - 1] = '\0';
+ s++;
+ mode = SIMPLE_PATTERN_SUBSTRING;
+ }
+ else if(len >= 1 && *s == '*') {
+ s++;
+ mode = SIMPLE_PATTERN_SUFFIX;
+ }
+ else if(len >= 1 && s[len - 1] == '*') {
+ s[len - 1] = '\0';
+ mode = SIMPLE_PATTERN_PREFIX;
+ }
+ else
+ mode = default_mode;
+
+ // allocate the structure
+ struct simple_pattern *m = callocz(1, sizeof(struct simple_pattern));
+ if(*s) {
+ m->match = strdupz(s);
+ m->len = strlen(m->match);
+ m->mode = mode;
+ }
+ else {
+ m->mode = SIMPLE_PATTERN_SUBSTRING;
+ }
+
+ m->child = child;
+
+ return m;
+}
+
+SIMPLE_PATTERN *simple_pattern_create(const char *list, const char *separators, SIMPLE_PREFIX_MODE default_mode) {
+ struct simple_pattern *root = NULL, *last = NULL;
+
+ if(unlikely(!list || !*list)) return root;
+
+ int isseparator[256] = {
+ [' '] = 1 // space
+ , ['\t'] = 1 // tab
+ , ['\r'] = 1 // carriage return
+ , ['\n'] = 1 // new line
+ , ['\f'] = 1 // form feed
+ , ['\v'] = 1 // vertical tab
+ };
+
+ if (unlikely(separators && *separators)) {
+ memset(&isseparator[0], 0, sizeof(isseparator));
+ while(*separators) isseparator[(unsigned char)*separators++] = 1;
+ }
+
+ char *buf = mallocz(strlen(list) + 1);
+ const char *s = list;
+
+ while(s && *s) {
+ buf[0] = '\0';
+ char *c = buf;
+
+ char negative = 0;
+
+ // skip all spaces
+ while(isseparator[(unsigned char)*s])
+ s++;
+
+ if(*s == '!') {
+ negative = 1;
+ s++;
+ }
+
+ // empty string
+ if(unlikely(!*s))
+ break;
+
+ // find the next space
+ char escape = 0;
+ while(*s) {
+ if(*s == '\\' && !escape) {
+ escape = 1;
+ s++;
+ }
+ else {
+ if (isseparator[(unsigned char)*s] && !escape) {
+ s++;
+ break;
+ }
+
+ *c++ = *s++;
+ escape = 0;
+ }
+ }
+
+ // terminate our string
+ *c = '\0';
+
+ // if we matched the empty string, skip it
+ if(unlikely(!*buf))
+ continue;
+
+ // fprintf(stderr, "FOUND PATTERN: '%s'\n", buf);
+ struct simple_pattern *m = parse_pattern(buf, default_mode);
+ m->negative = negative;
+
+ // link it at the end
+ if(unlikely(!root))
+ root = last = m;
+ else {
+ last->next = m;
+ last = m;
+ }
+ }
+
+ freez(buf);
+ return (SIMPLE_PATTERN *)root;
+}
+
+static inline char *add_wildcarded(const char *matched, size_t matched_size, char *wildcarded, size_t *wildcarded_size) {
+ //if(matched_size) {
+ // char buf[matched_size + 1];
+ // strncpyz(buf, matched, matched_size);
+ // fprintf(stderr, "ADD WILDCARDED '%s' of length %zu\n", buf, matched_size);
+ //}
+
+ if(unlikely(wildcarded && *wildcarded_size && matched && *matched && matched_size)) {
+ size_t wss = *wildcarded_size - 1;
+ size_t len = (matched_size < wss)?matched_size:wss;
+ if(likely(len)) {
+ strncpyz(wildcarded, matched, len);
+
+ *wildcarded_size -= len;
+ return &wildcarded[len];
+ }
+ }
+
+ return wildcarded;
+}
+
+static inline int match_pattern(struct simple_pattern *m, const char *str, size_t len, char *wildcarded, size_t *wildcarded_size) {
+ char *s;
+
+ if(m->len <= len) {
+ switch(m->mode) {
+ case SIMPLE_PATTERN_SUBSTRING:
+ if(!m->len) return 1;
+ if((s = strstr(str, m->match))) {
+ wildcarded = add_wildcarded(str, s - str, wildcarded, wildcarded_size);
+ if(!m->child) {
+ wildcarded = add_wildcarded(&s[m->len], len - (&s[m->len] - str), wildcarded, wildcarded_size);
+ return 1;
+ }
+ return match_pattern(m->child, &s[m->len], len - (s - str) - m->len, wildcarded, wildcarded_size);
+ }
+ break;
+
+ case SIMPLE_PATTERN_PREFIX:
+ if(unlikely(strncmp(str, m->match, m->len) == 0)) {
+ if(!m->child) {
+ wildcarded = add_wildcarded(&str[m->len], len - m->len, wildcarded, wildcarded_size);
+ return 1;
+ }
+ return match_pattern(m->child, &str[m->len], len - m->len, wildcarded, wildcarded_size);
+ }
+ break;
+
+ case SIMPLE_PATTERN_SUFFIX:
+ if(unlikely(strcmp(&str[len - m->len], m->match) == 0)) {
+ wildcarded = add_wildcarded(str, len - m->len, wildcarded, wildcarded_size);
+ if(!m->child) return 1;
+ return 0;
+ }
+ break;
+
+ case SIMPLE_PATTERN_EXACT:
+ default:
+ if(unlikely(strcmp(str, m->match) == 0)) {
+ if(!m->child) return 1;
+ return 0;
+ }
+ break;
+ }
+ }
+
+ return 0;
+}
+
+int simple_pattern_matches_extract(SIMPLE_PATTERN *list, const char *str, char *wildcarded, size_t wildcarded_size) {
+ struct simple_pattern *m, *root = (struct simple_pattern *)list;
+
+ if(unlikely(!root || !str || !*str)) return 0;
+
+ size_t len = strlen(str);
+ for(m = root; m ; m = m->next) {
+ char *ws = wildcarded;
+ size_t wss = wildcarded_size;
+ if(unlikely(ws)) *ws = '\0';
+
+ if (match_pattern(m, str, len, ws, &wss)) {
+
+ //if(ws && wss)
+ // fprintf(stderr, "FINAL WILDCARDED '%s' of length %zu\n", ws, strlen(ws));
+
+ if (m->negative) return 0;
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+static inline void free_pattern(struct simple_pattern *m) {
+ if(!m) return;
+
+ free_pattern(m->child);
+ free_pattern(m->next);
+ freez((void *)m->match);
+ freez(m);
+}
+
+void simple_pattern_free(SIMPLE_PATTERN *list) {
+ if(!list) return;
+
+ free_pattern(((struct simple_pattern *)list));
+}
+
+/* Debugging patterns
+
+ This code should be dead - it is useful for debugging but should not be called by production code.
+ Feel free to comment it out, but please leave it in the file.
+*/
+extern void simple_pattern_dump(uint64_t debug_type, SIMPLE_PATTERN *p)
+{
+ struct simple_pattern *root = (struct simple_pattern *)p;
+ if(root==NULL) {
+ debug(debug_type,"dump_pattern(NULL)");
+ return;
+ }
+ debug(debug_type,"dump_pattern(%p) child=%p next=%p mode=%u match=%s", root, root->child, root->next, root->mode,
+ root->match);
+ if(root->child!=NULL)
+ simple_pattern_dump(debug_type, (SIMPLE_PATTERN*)root->child);
+ if(root->next!=NULL)
+ simple_pattern_dump(debug_type, (SIMPLE_PATTERN*)root->next);
+}
+
+/* Heuristic: decide if the pattern could match a DNS name.
+
+ Although this functionality is used directly by socket.c:connection_allowed() it must be in this file
+ because of the SIMPLE_PATTERN/simple_pattern structure hiding.
+ Based on RFC952 / RFC1123. We need to decide if the pattern may match a DNS name, or not. For the negative
+ cases we need to be sure that it can only match an ipv4 or ipv6 address:
+ * IPv6 addresses contain ':', which are illegal characters in DNS.
+ * IPv4 addresses cannot contain alpha- characters.
+ * DNS TLDs must be alphanumeric to distinguish from IPv4.
+ Some patterns (e.g. "*a*" ) could match multiple cases (i.e. DNS or IPv6).
+ Some patterns will be awkward (e.g. "192.168.*") as they look like they are intended to match IPv4-only
+ but could match DNS (i.e. "192.168.com" is a valid name).
+*/
+static void scan_is_potential_name(struct simple_pattern *p, int *alpha, int *colon, int *wildcards)
+{
+ while (p) {
+ if (p->match) {
+ if(p->mode == SIMPLE_PATTERN_EXACT && !strcmp("localhost", p->match)) {
+ p = p->child;
+ continue;
+ }
+ char const *scan = p->match;
+ while (*scan != 0) {
+ if ((*scan >= 'a' && *scan <= 'z') || (*scan >= 'A' && *scan <= 'Z'))
+ *alpha = 1;
+ if (*scan == ':')
+ *colon = 1;
+ scan++;
+ }
+ if (p->mode != SIMPLE_PATTERN_EXACT)
+ *wildcards = 1;
+ p = p->child;
+ }
+ }
+}
+
+extern int simple_pattern_is_potential_name(SIMPLE_PATTERN *p)
+{
+ int alpha=0, colon=0, wildcards=0;
+ struct simple_pattern *root = (struct simple_pattern*)p;
+ while (root != NULL) {
+ if (root->match != NULL) {
+ scan_is_potential_name(root, &alpha, &colon, &wildcards);
+ }
+ if (root->mode != SIMPLE_PATTERN_EXACT)
+ wildcards = 1;
+ root = root->next;
+ }
+ return (alpha || wildcards) && !colon;
+}
+
+char *simple_pattern_trim_around_equal(char *src) {
+ char *store = mallocz(strlen(src) +1);
+ if(!store)
+ return NULL;
+
+ char *dst = store;
+ while (*src) {
+ if (*src == '=') {
+ if (*(dst -1) == ' ')
+ dst--;
+
+ *dst++ = *src++;
+ if (*src == ' ')
+ src++;
+ }
+
+ *dst++ = *src++;
+ }
+ *dst = 0x00;
+
+ return store;
+}
+
+char *simple_pattern_iterate(SIMPLE_PATTERN **p)
+{
+ struct simple_pattern *root = (struct simple_pattern *) *p;
+ struct simple_pattern **Proot = (struct simple_pattern **)p;
+
+ (*Proot) = (*Proot)->next;
+ return (char *) root->match;
+}
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