Commit | Line | Data |
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059ec3d9 PH |
1 | /************************************************* |
2 | * Exim - an Internet mail transport agent * | |
3 | *************************************************/ | |
4 | ||
80fea873 | 5 | /* Copyright (c) University of Cambridge 1995 - 2016 */ |
059ec3d9 PH |
6 | /* See the file NOTICE for conditions of use and distribution. */ |
7 | ||
8 | ||
9 | #include "exim.h" | |
10 | ||
11 | ||
12 | /************************************************* | |
13 | * Test a header for matching name * | |
14 | *************************************************/ | |
15 | ||
16 | /* This function tests the name of a header. It is made into a function because | |
17 | it isn't just a string comparison: spaces and tabs are permitted between the | |
18 | name and the colon. The h->text field should nowadays never be NULL, but check | |
19 | it just in case. | |
20 | ||
21 | Arguments: | |
22 | h points to the header | |
23 | name the name to test | |
24 | len the length of the name | |
25 | notdel if TRUE, force FALSE for deleted headers | |
26 | ||
27 | Returns: TRUE or FALSE | |
28 | */ | |
29 | ||
30 | BOOL | |
1ba28e2b | 31 | header_testname(header_line *h, const uschar *name, int len, BOOL notdel) |
059ec3d9 PH |
32 | { |
33 | uschar *tt; | |
34 | if (h->type == '*' && notdel) return FALSE; | |
35 | if (h->text == NULL || strncmpic(h->text, name, len) != 0) return FALSE; | |
36 | tt = h->text + len; | |
37 | while (*tt == ' ' || *tt == '\t') tt++; | |
38 | return *tt == ':'; | |
39 | } | |
40 | ||
8523533c TK |
41 | /* This is a copy of the function above, only that it is possible to pass |
42 | only the beginning of a header name. It simply does a front-anchored | |
43 | substring match. Arguments and Return codes are the same as for | |
44 | header_testname() above. */ | |
45 | ||
46 | BOOL | |
1ba28e2b PP |
47 | header_testname_incomplete(header_line *h, const uschar *name, |
48 | int len, BOOL notdel) | |
8523533c | 49 | { |
8523533c TK |
50 | if (h->type == '*' && notdel) return FALSE; |
51 | if (h->text == NULL || strncmpic(h->text, name, len) != 0) return FALSE; | |
52 | return TRUE; | |
53 | } | |
059ec3d9 PH |
54 | |
55 | ||
56 | /************************************************* | |
57 | * Add new header backend function * | |
58 | *************************************************/ | |
59 | ||
60 | /* The header_last variable points to the last header during message reception | |
61 | and delivery; otherwise it is NULL. We add new headers only when header_last is | |
62 | not NULL. The function may get called sometimes when it is NULL (e.g. during | |
63 | address verification where rewriting options exist). When called from a filter, | |
64 | there may be multiple header lines in a single string. | |
65 | ||
66 | This is an internal static function that is the common back end to the external | |
67 | functions defined below. The general interface allows the header to be inserted | |
68 | before or after a given occurrence of a given header. | |
69 | ||
70 | (a) if "name" is NULL, the header is added at the end of all the existing | |
71 | headers if "after" is true, or at the start if it is false. The "topnot" | |
72 | flag is not used. | |
73 | ||
74 | (b) If "name" is not NULL, the first existing header with that name is sought. | |
75 | If "after" is false, the new header is added before it. If "after" is true, | |
76 | a check is made for adjacent headers with the same name, and the new header | |
77 | is added after the last of them. If a header of the given name is not | |
78 | found, the new header is added first if "topnot" is true, and at the bottom | |
79 | otherwise. | |
80 | ||
81 | Arguments: | |
82 | after TRUE for "after", FALSE for "before" | |
83 | name name if adding at a specific header, else NULL | |
84 | topnot TRUE to add at top if no header found | |
85 | type Exim header type character (htype_something) | |
86 | format sprintf format | |
87 | ap va_list value for format arguments | |
88 | ||
049782c0 | 89 | Returns: pointer to header struct (last one, if multiple added) |
059ec3d9 PH |
90 | */ |
91 | ||
049782c0 | 92 | static header_line * |
059ec3d9 | 93 | header_add_backend(BOOL after, uschar *name, BOOL topnot, int type, |
1ba28e2b | 94 | const char *format, va_list ap) |
059ec3d9 | 95 | { |
dca6d121 | 96 | header_line *h, *new = NULL; |
059ec3d9 PH |
97 | header_line **hptr; |
98 | ||
99 | uschar *p, *q; | |
100 | uschar buffer[HEADER_ADD_BUFFER_SIZE]; | |
d12746bc | 101 | gstring gs = { .size = HEADER_ADD_BUFFER_SIZE, .ptr = 0, .s = buffer }; |
059ec3d9 | 102 | |
049782c0 | 103 | if (!header_last) return NULL; |
059ec3d9 | 104 | |
d12746bc | 105 | if (!string_vformat(&gs, FALSE, format, ap)) |
059ec3d9 | 106 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "string too long in header_add: " |
d12746bc JH |
107 | "%.100s ...", string_from_gstring(&gs)); |
108 | string_from_gstring(&gs); | |
059ec3d9 PH |
109 | |
110 | /* Find where to insert this header */ | |
111 | ||
94759fce | 112 | if (!name) |
059ec3d9 PH |
113 | if (after) |
114 | { | |
dca6d121 | 115 | hptr = &header_last->next; |
059ec3d9 PH |
116 | h = NULL; |
117 | } | |
118 | else | |
119 | { | |
120 | hptr = &header_list; | |
5eb690a1 NM |
121 | |
122 | /* header_list->text can be NULL if we get here between when the new | |
4c04137d | 123 | received header is allocated and when it is actually filled in. We want |
5eb690a1 NM |
124 | that header to be first, so skip it for now. */ |
125 | ||
94759fce | 126 | if (!header_list->text) |
5eb690a1 NM |
127 | hptr = &header_list->next; |
128 | h = *hptr; | |
059ec3d9 | 129 | } |
059ec3d9 PH |
130 | |
131 | else | |
132 | { | |
133 | int len = Ustrlen(name); | |
134 | ||
4c04137d | 135 | /* Find the first non-deleted header with the correct name. */ |
059ec3d9 | 136 | |
94759fce JH |
137 | for (hptr = &header_list; (h = *hptr); hptr = &h->next) |
138 | if (header_testname(h, name, len, TRUE)) | |
139 | break; | |
059ec3d9 PH |
140 | |
141 | /* Handle the case where no header is found. To insert at the bottom, nothing | |
142 | needs to be done. */ | |
143 | ||
94759fce | 144 | if (!h) |
059ec3d9 PH |
145 | { |
146 | if (topnot) | |
147 | { | |
148 | hptr = &header_list; | |
149 | h = header_list; | |
150 | } | |
151 | } | |
152 | ||
153 | /* Handle the case where a header is found. Check for more if "after" is | |
154 | true. In this case, we want to include deleted headers in the block. */ | |
155 | ||
156 | else if (after) | |
059ec3d9 PH |
157 | for (;;) |
158 | { | |
94759fce | 159 | if (!h->next || !header_testname(h, name, len, FALSE)) break; |
dca6d121 | 160 | hptr = &h->next; |
059ec3d9 PH |
161 | h = h->next; |
162 | } | |
059ec3d9 PH |
163 | } |
164 | ||
165 | /* Loop for multiple header lines, taking care about continuations. At this | |
166 | point, we have hptr pointing to the link field that will point to the new | |
167 | header, and h containing the following header, or NULL. */ | |
168 | ||
dca6d121 | 169 | for (p = q = buffer; *p; p = q) |
059ec3d9 PH |
170 | { |
171 | for (;;) | |
172 | { | |
173 | q = Ustrchr(q, '\n'); | |
94759fce | 174 | if (!q) q = p + Ustrlen(p); |
059ec3d9 PH |
175 | if (*(++q) != ' ' && *q != '\t') break; |
176 | } | |
177 | ||
178 | new = store_get(sizeof(header_line)); | |
179 | new->text = string_copyn(p, q - p); | |
180 | new->slen = q - p; | |
181 | new->type = type; | |
182 | new->next = h; | |
183 | ||
184 | *hptr = new; | |
dca6d121 | 185 | hptr = &new->next; |
059ec3d9 | 186 | |
94759fce | 187 | if (!h) header_last = new; |
059ec3d9 | 188 | } |
049782c0 | 189 | return new; |
059ec3d9 PH |
190 | } |
191 | ||
192 | ||
193 | /************************************************* | |
194 | * Add new header anywhere in the chain * | |
195 | *************************************************/ | |
196 | ||
197 | /* This is an external interface to header_add_backend(). | |
198 | ||
199 | Arguments: | |
200 | after TRUE for "after", FALSE for "before" | |
201 | name name if adding at a specific header, else NULL | |
202 | topnot TRUE to add at top if no header found | |
203 | type Exim header type character (htype_something) | |
204 | format sprintf format | |
205 | ... format arguments | |
206 | ||
049782c0 | 207 | Returns: pointer to header struct added |
059ec3d9 PH |
208 | */ |
209 | ||
049782c0 JH |
210 | header_line * |
211 | header_add_at_position_internal(BOOL after, uschar *name, BOOL topnot, int type, | |
1ba28e2b | 212 | const char *format, ...) |
059ec3d9 | 213 | { |
049782c0 | 214 | header_line * h; |
059ec3d9 PH |
215 | va_list ap; |
216 | va_start(ap, format); | |
049782c0 | 217 | h = header_add_backend(after, name, topnot, type, format, ap); |
059ec3d9 | 218 | va_end(ap); |
049782c0 | 219 | return h; |
059ec3d9 PH |
220 | } |
221 | ||
222 | ||
049782c0 JH |
223 | /* Documented external i/f for local_scan */ |
224 | void | |
225 | header_add_at_position(BOOL after, uschar *name, BOOL topnot, int type, | |
226 | const char *format, ...) | |
227 | { | |
049782c0 JH |
228 | va_list ap; |
229 | va_start(ap, format); | |
230 | (void) header_add_backend(after, name, topnot, type, format, ap); | |
231 | va_end(ap); | |
232 | } | |
059ec3d9 PH |
233 | |
234 | /************************************************* | |
235 | * Add new header on end of chain * | |
236 | *************************************************/ | |
237 | ||
238 | /* This is now a convenience interface to header_add_backend(). | |
239 | ||
240 | Arguments: | |
241 | type Exim header type character | |
242 | format sprintf format | |
243 | ... arguments for the format | |
244 | ||
245 | Returns: nothing | |
246 | */ | |
247 | ||
248 | void | |
1ba28e2b | 249 | header_add(int type, const char *format, ...) |
059ec3d9 PH |
250 | { |
251 | va_list ap; | |
252 | va_start(ap, format); | |
049782c0 | 253 | (void) header_add_backend(TRUE, NULL, FALSE, type, format, ap); |
059ec3d9 PH |
254 | va_end(ap); |
255 | } | |
256 | ||
257 | ||
258 | ||
259 | /************************************************* | |
260 | * Remove (mark as old) a header * | |
261 | *************************************************/ | |
262 | ||
263 | /* This function is used by the filter code; it is also exported in the | |
264 | local_scan() API. If no header is found, the function does nothing. | |
265 | ||
266 | Arguments: | |
267 | occ the occurrence number for multiply-defined headers | |
268 | <= 0 means "all"; deleted headers are not counted | |
269 | name the header name | |
270 | ||
271 | Returns: nothing | |
272 | */ | |
273 | ||
274 | void | |
1ba28e2b | 275 | header_remove(int occ, const uschar *name) |
059ec3d9 | 276 | { |
059ec3d9 PH |
277 | int hcount = 0; |
278 | int len = Ustrlen(name); | |
d7978c0f | 279 | for (header_line * h = header_list; h; h = h->next) |
059ec3d9 PH |
280 | if (header_testname(h, name, len, TRUE) && (occ <= 0 || ++hcount == occ)) |
281 | { | |
282 | h->type = htype_old; | |
283 | if (occ > 0) return; | |
284 | } | |
059ec3d9 PH |
285 | } |
286 | ||
287 | ||
288 | ||
289 | /************************************************* | |
290 | * Check the name of a header * | |
291 | *************************************************/ | |
292 | ||
293 | /* This function scans a table of header field names that Exim recognizes, and | |
294 | returns the identification of a match. If "resent" is true, the header is known | |
295 | to start with "resent-". In that case, the function matches only those fields | |
296 | that are allowed to appear with resent- in front of them. | |
297 | ||
298 | Arguments: | |
299 | h points to the header line | |
300 | is_resent TRUE if the name starts "Resent-" | |
301 | ||
302 | Returns: One of the htype_ enum values, identifying the header | |
303 | */ | |
304 | ||
305 | int | |
306 | header_checkname(header_line *h, BOOL is_resent) | |
307 | { | |
308 | uschar *text = h->text; | |
309 | header_name *bot = header_names; | |
310 | header_name *top = header_names + header_names_size; | |
311 | ||
312 | if (is_resent) text += 7; | |
313 | ||
314 | while (bot < top) | |
315 | { | |
316 | header_name *mid = bot + (top - bot)/2; | |
317 | int c = strncmpic(text, mid->name, mid->len); | |
318 | ||
319 | if (c == 0) | |
320 | { | |
321 | uschar *s = text + mid->len; | |
322 | while (isspace(*s)) s++; | |
323 | if (*s == ':') | |
324 | return (!is_resent || mid->allow_resent)? mid->htype : htype_other; | |
325 | c = 1; | |
326 | } | |
327 | ||
328 | if (c > 0) bot = mid + 1; else top = mid; | |
329 | } | |
330 | ||
331 | return htype_other; | |
332 | } | |
333 | ||
334 | ||
335 | /************************************************* | |
336 | * Scan a header for certain strings * | |
337 | *************************************************/ | |
338 | ||
339 | /* This function is used for the "personal" test. It scans a particular header | |
340 | line for any one of a number of strings, matched caselessly either as plain | |
341 | strings, or as regular expressions. If the header line contains a list of | |
342 | addresses, each match is applied only to the operative part of each address in | |
343 | the header, and non-regular expressions must be exact matches. | |
344 | ||
345 | The patterns can be provided either as a chain of string_item structures, or | |
346 | inline in the argument list, or both. If there is more than one header of the | |
347 | same name, they are all searched. | |
348 | ||
349 | Arguments: | |
350 | name header name, including the trailing colon | |
351 | has_addresses TRUE if the header contains a list of addresses | |
352 | cond value to return if the header contains any of the strings | |
353 | strings points to a chain of string_item blocks | |
354 | count number of inline strings | |
355 | ... the inline strings | |
356 | ||
357 | Returns: cond if the header exists and contains one of the strings; | |
358 | otherwise !cond | |
359 | */ | |
360 | ||
361 | ||
362 | /* First we have a local subroutine to handle a single pattern */ | |
363 | ||
364 | static BOOL | |
365 | one_pattern_match(uschar *name, int slen, BOOL has_addresses, uschar *pattern) | |
366 | { | |
367 | BOOL yield = FALSE; | |
059ec3d9 PH |
368 | const pcre *re = NULL; |
369 | ||
370 | /* If the pattern is a regex, compile it. Bomb out if compiling fails; these | |
371 | patterns are all constructed internally and should be valid. */ | |
372 | ||
373 | if (*pattern == '^') re = regex_must_compile(pattern, TRUE, FALSE); | |
374 | ||
375 | /* Scan for the required header(s) and scan each one */ | |
376 | ||
d7978c0f | 377 | for (header_line * h = header_list; !yield && h; h = h->next) |
059ec3d9 PH |
378 | { |
379 | if (h->type == htype_old || slen > h->slen || | |
380 | strncmpic(name, h->text, slen) != 0) | |
381 | continue; | |
382 | ||
383 | /* If the header is a list of addresses, extract each one in turn, and scan | |
384 | it. A non-regex scan must be an exact match for the address. */ | |
385 | ||
386 | if (has_addresses) | |
387 | { | |
388 | uschar *s = h->text + slen; | |
389 | ||
d7978c0f | 390 | while (!yield && *s) |
059ec3d9 PH |
391 | { |
392 | uschar *error, *next; | |
393 | uschar *e = parse_find_address_end(s, FALSE); | |
394 | int terminator = *e; | |
395 | int start, end, domain; | |
396 | ||
397 | /* Temporarily terminate the string at the address end while extracting | |
398 | the operative address within. */ | |
399 | ||
400 | *e = 0; | |
401 | next = parse_extract_address(s, &error, &start, &end, &domain, FALSE); | |
402 | *e = terminator; | |
403 | ||
404 | /* Move on, ready for the next address */ | |
405 | ||
406 | s = e; | |
407 | if (*s == ',') s++; | |
408 | ||
409 | /* If there is some kind of syntax error, just give up on this header | |
410 | line. */ | |
411 | ||
412 | if (next == NULL) break; | |
413 | ||
414 | /* Otherwise, test for the pattern; a non-regex must be an exact match */ | |
415 | ||
416 | yield = (re == NULL)? | |
417 | (strcmpic(next, pattern) == 0) | |
418 | : | |
419 | (pcre_exec(re, NULL, CS next, Ustrlen(next), 0, PCRE_EOPT, NULL, 0) | |
420 | >= 0); | |
421 | } | |
422 | } | |
423 | ||
424 | /* For headers that are not lists of addresses, scan the entire header line, | |
425 | and just require "contains" for non-regex patterns. */ | |
426 | ||
427 | else | |
428 | { | |
429 | yield = (re == NULL)? | |
430 | (strstric(h->text, pattern, FALSE) != NULL) | |
431 | : | |
432 | (pcre_exec(re, NULL, CS h->text, h->slen, 0, PCRE_EOPT, NULL, 0) >= 0); | |
433 | } | |
434 | } | |
435 | ||
436 | return yield; | |
437 | } | |
438 | ||
439 | ||
440 | /* The externally visible interface */ | |
441 | ||
442 | BOOL | |
443 | header_match(uschar *name, BOOL has_addresses, BOOL cond, string_item *strings, | |
444 | int count, ...) | |
445 | { | |
446 | va_list ap; | |
059ec3d9 PH |
447 | int slen = Ustrlen(name); |
448 | ||
d7978c0f JH |
449 | for (string_item * s = strings; s; s = s->next) |
450 | if (one_pattern_match(name, slen, has_addresses, s->text)) | |
451 | return cond; | |
059ec3d9 PH |
452 | |
453 | va_start(ap, count); | |
d7978c0f | 454 | for (int i = 0; i < count; i++) |
059ec3d9 | 455 | if (one_pattern_match(name, slen, has_addresses, va_arg(ap, uschar *))) |
cb570b5e JH |
456 | { |
457 | va_end(ap); | |
059ec3d9 | 458 | return cond; |
cb570b5e | 459 | } |
059ec3d9 PH |
460 | va_end(ap); |
461 | ||
462 | return !cond; | |
463 | } | |
464 | ||
465 | /* End of header.c */ |