summaryrefslogtreecommitdiffstats
path: root/src/libnetdata/simple_pattern/simple_pattern.c
blob: 7a7f41b1c81f696f777e359318a3fa4422b29b25 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
// SPDX-License-Identifier: GPL-3.0-or-later

#include "../libnetdata.h"

struct simple_pattern {
    const char *match;
    uint32_t len;

    SIMPLE_PREFIX_MODE mode;
    bool negative;
    bool case_sensitive;

    struct simple_pattern *child;
    struct simple_pattern *next;
};

static struct simple_pattern *parse_pattern(char *str, SIMPLE_PREFIX_MODE default_mode, size_t count) {
    if(unlikely(count >= 1000))
        return NULL;

    // 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, count + 1);
        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, bool case_sensitive) {
    struct simple_pattern *root = NULL, *last = NULL;

    if(unlikely(!list || !*list)) return root;

    char 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;

        bool negative = false;

        // skip all spaces
        while(isseparator[(unsigned char)*s])
            s++;

        if(*s == '!') {
            negative = true;
            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, 0);
        m->negative = negative;
        m->case_sensitive = case_sensitive;

        if(default_mode == SIMPLE_PATTERN_SUBSTRING) {
            m->mode = SIMPLE_PATTERN_SUBSTRING;

            struct simple_pattern *tm;
            for(tm = m; tm->child ; tm = tm->child) ;
            tm->mode = SIMPLE_PATTERN_SUBSTRING;
        }

        // 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 sp_strcmp(const char *s1, const char *s2, bool case_sensitive) {
    if(case_sensitive)
        return strcmp(s1, s2);

    return strcasecmp(s1, s2);
}

static inline int sp_strncmp(const char *s1, const char *s2, size_t n, bool case_sensitive) {
    if(case_sensitive)
        return strncmp(s1, s2, n);

    return strncasecmp(s1, s2, n);
}

static inline char *sp_strstr(const char *haystack, const char *needle, bool case_sensitive) {
    if(case_sensitive)
        return strstr(haystack, needle);

    return strcasestr(haystack, needle);
}

static inline bool match_pattern(struct simple_pattern *m, const char *str, size_t len, char *wildcarded, size_t *wildcarded_size) {
    char *s;

    bool loop = true;
    while(loop && m->len <= len) {
        loop = false;

        switch(m->mode) {
            default:
            case SIMPLE_PATTERN_EXACT:
                if(unlikely(sp_strcmp(str, m->match, m->case_sensitive) == 0)) {
                    if(!m->child) return true;
                    return false;
                }
                break;

            case SIMPLE_PATTERN_SUBSTRING:
                if(!m->len) return true;
                if((s = sp_strstr(str, m->match, m->case_sensitive))) {
                    wildcarded = add_wildcarded(str, s - str, wildcarded, wildcarded_size);
                    if(!m->child) {
                        add_wildcarded(&s[m->len], len - (&s[m->len] - str), wildcarded, wildcarded_size);
                        return true;
                    }

                    // instead of recursion
                    {
                        len = len - (s - str) - m->len;
                        str = &s[m->len];
                        m = m->child;
                        loop = true;
                        // return match_pattern(m->child, &s[m->len], len - (s - str) - m->len, wildcarded, wildcarded_size);
                    }
                }
                break;

            case SIMPLE_PATTERN_PREFIX:
                if(unlikely(sp_strncmp(str, m->match, m->len, m->case_sensitive) == 0)) {
                    if(!m->child) {
                        add_wildcarded(&str[m->len], len - m->len, wildcarded, wildcarded_size);
                        return true;
                    }
                    // instead of recursion
                    {
                        len = len - m->len;
                        str = &str[m->len];
                        m = m->child;
                        loop = true;
                        // return match_pattern(m->child, &str[m->len], len - m->len, wildcarded, wildcarded_size);
                    }
                }
                break;

            case SIMPLE_PATTERN_SUFFIX:
                if(unlikely(sp_strcmp(&str[len - m->len], m->match, m->case_sensitive) == 0)) {
                    add_wildcarded(str, len - m->len, wildcarded, wildcarded_size);
                    if(!m->child) return true;
                    return false;
                }
                break;
        }
    }

    return false;
}

static inline SIMPLE_PATTERN_RESULT simple_pattern_matches_extract_with_length(SIMPLE_PATTERN *list, const char *str, size_t len, char *wildcarded, size_t wildcarded_size) {
    struct simple_pattern *m, *root = (struct simple_pattern *)list;

    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 (m->negative) return SP_MATCHED_NEGATIVE;
            return SP_MATCHED_POSITIVE;
        }
    }

    return SP_NOT_MATCHED;
}

SIMPLE_PATTERN_RESULT simple_pattern_matches_buffer_extract(SIMPLE_PATTERN *list, BUFFER *str, char *wildcarded, size_t wildcarded_size) {
    if(!list || !str || buffer_strlen(str)) return SP_NOT_MATCHED;
    return simple_pattern_matches_extract_with_length(list, buffer_tostring(str), buffer_strlen(str), wildcarded, wildcarded_size);
}

SIMPLE_PATTERN_RESULT simple_pattern_matches_string_extract(SIMPLE_PATTERN *list, STRING *str, char *wildcarded, size_t wildcarded_size) {
    if(!list || !str) return SP_NOT_MATCHED;
    return simple_pattern_matches_extract_with_length(list, string2str(str), string_strlen(str), wildcarded, wildcarded_size);
}

SIMPLE_PATTERN_RESULT simple_pattern_matches_extract(SIMPLE_PATTERN *list, const char *str, char *wildcarded, size_t wildcarded_size) {
    if(!list || !str || !*str) return SP_NOT_MATCHED;
    return simple_pattern_matches_extract_with_length(list, str, strlen(str), wildcarded, wildcarded_size);
}

SIMPLE_PATTERN_RESULT simple_pattern_matches_length_extract(SIMPLE_PATTERN *list, const char *str, size_t len, char *wildcarded, size_t wildcarded_size) {
    if(!list || !str || !*str || !len) return SP_NOT_MATCHED;
    return simple_pattern_matches_extract_with_length(list, str, len, wildcarded, wildcarded_size);
}

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) {
        netdata_log_debug(debug_type,"dump_pattern(NULL)");
        return;
    }
    netdata_log_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_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;
}