Commit | Line | Data |
---|---|---|
059ec3d9 PH |
1 | /************************************************* |
2 | * Exim - an Internet mail transport agent * | |
3 | *************************************************/ | |
4 | ||
80fea873 | 5 | /* Copyright (c) University of Cambridge 1995 - 2016 */ |
1e1ddfac | 6 | /* Copyright (c) The Exim Maintainers 2020 */ |
059ec3d9 PH |
7 | /* See the file NOTICE for conditions of use and distribution. */ |
8 | ||
9 | ||
10 | #include "exim.h" | |
11 | ||
12 | ||
13 | /************************************************* | |
14 | * Test a header for matching name * | |
15 | *************************************************/ | |
16 | ||
17 | /* This function tests the name of a header. It is made into a function because | |
18 | it isn't just a string comparison: spaces and tabs are permitted between the | |
19 | name and the colon. The h->text field should nowadays never be NULL, but check | |
20 | it just in case. | |
21 | ||
22 | Arguments: | |
23 | h points to the header | |
24 | name the name to test | |
25 | len the length of the name | |
26 | notdel if TRUE, force FALSE for deleted headers | |
27 | ||
28 | Returns: TRUE or FALSE | |
29 | */ | |
30 | ||
31 | BOOL | |
1ba28e2b | 32 | header_testname(header_line *h, const uschar *name, int len, BOOL notdel) |
059ec3d9 PH |
33 | { |
34 | uschar *tt; | |
35 | if (h->type == '*' && notdel) return FALSE; | |
36 | if (h->text == NULL || strncmpic(h->text, name, len) != 0) return FALSE; | |
37 | tt = h->text + len; | |
38 | while (*tt == ' ' || *tt == '\t') tt++; | |
39 | return *tt == ':'; | |
40 | } | |
41 | ||
8523533c TK |
42 | /* This is a copy of the function above, only that it is possible to pass |
43 | only the beginning of a header name. It simply does a front-anchored | |
44 | substring match. Arguments and Return codes are the same as for | |
45 | header_testname() above. */ | |
46 | ||
47 | BOOL | |
1ba28e2b PP |
48 | header_testname_incomplete(header_line *h, const uschar *name, |
49 | int len, BOOL notdel) | |
8523533c | 50 | { |
8523533c TK |
51 | if (h->type == '*' && notdel) return FALSE; |
52 | if (h->text == NULL || strncmpic(h->text, name, len) != 0) return FALSE; | |
53 | return TRUE; | |
54 | } | |
059ec3d9 PH |
55 | |
56 | ||
57 | /************************************************* | |
58 | * Add new header backend function * | |
59 | *************************************************/ | |
60 | ||
61 | /* The header_last variable points to the last header during message reception | |
62 | and delivery; otherwise it is NULL. We add new headers only when header_last is | |
63 | not NULL. The function may get called sometimes when it is NULL (e.g. during | |
64 | address verification where rewriting options exist). When called from a filter, | |
65 | there may be multiple header lines in a single string. | |
66 | ||
67 | This is an internal static function that is the common back end to the external | |
68 | functions defined below. The general interface allows the header to be inserted | |
69 | before or after a given occurrence of a given header. | |
70 | ||
71 | (a) if "name" is NULL, the header is added at the end of all the existing | |
72 | headers if "after" is true, or at the start if it is false. The "topnot" | |
73 | flag is not used. | |
74 | ||
75 | (b) If "name" is not NULL, the first existing header with that name is sought. | |
76 | If "after" is false, the new header is added before it. If "after" is true, | |
77 | a check is made for adjacent headers with the same name, and the new header | |
78 | is added after the last of them. If a header of the given name is not | |
79 | found, the new header is added first if "topnot" is true, and at the bottom | |
80 | otherwise. | |
81 | ||
82 | Arguments: | |
83 | after TRUE for "after", FALSE for "before" | |
84 | name name if adding at a specific header, else NULL | |
85 | topnot TRUE to add at top if no header found | |
86 | type Exim header type character (htype_something) | |
87 | format sprintf format | |
88 | ap va_list value for format arguments | |
89 | ||
049782c0 | 90 | Returns: pointer to header struct (last one, if multiple added) |
059ec3d9 PH |
91 | */ |
92 | ||
049782c0 | 93 | static header_line * |
059ec3d9 | 94 | header_add_backend(BOOL after, uschar *name, BOOL topnot, int type, |
1ba28e2b | 95 | const char *format, va_list ap) |
059ec3d9 | 96 | { |
dca6d121 | 97 | header_line *h, *new = NULL; |
059ec3d9 PH |
98 | header_line **hptr; |
99 | ||
100 | uschar *p, *q; | |
f3ebb786 JH |
101 | uschar * buf = store_get(HEADER_ADD_BUFFER_SIZE, FALSE); |
102 | gstring gs = { .size = HEADER_ADD_BUFFER_SIZE, .ptr = 0, .s = buf }; | |
059ec3d9 | 103 | |
049782c0 | 104 | if (!header_last) return NULL; |
059ec3d9 | 105 | |
f3ebb786 | 106 | if (!string_vformat(&gs, SVFMT_REBUFFER, format, ap)) |
059ec3d9 | 107 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "string too long in header_add: " |
d12746bc | 108 | "%.100s ...", string_from_gstring(&gs)); |
f3ebb786 JH |
109 | |
110 | if (gs.s != buf) store_release_above(buf); | |
111 | gstring_release_unused(&gs); | |
d12746bc | 112 | string_from_gstring(&gs); |
059ec3d9 PH |
113 | |
114 | /* Find where to insert this header */ | |
115 | ||
94759fce | 116 | if (!name) |
059ec3d9 PH |
117 | if (after) |
118 | { | |
dca6d121 | 119 | hptr = &header_last->next; |
059ec3d9 PH |
120 | h = NULL; |
121 | } | |
122 | else | |
123 | { | |
124 | hptr = &header_list; | |
5eb690a1 NM |
125 | |
126 | /* header_list->text can be NULL if we get here between when the new | |
4c04137d | 127 | received header is allocated and when it is actually filled in. We want |
5eb690a1 NM |
128 | that header to be first, so skip it for now. */ |
129 | ||
94759fce | 130 | if (!header_list->text) |
5eb690a1 NM |
131 | hptr = &header_list->next; |
132 | h = *hptr; | |
059ec3d9 | 133 | } |
059ec3d9 PH |
134 | |
135 | else | |
136 | { | |
137 | int len = Ustrlen(name); | |
138 | ||
4c04137d | 139 | /* Find the first non-deleted header with the correct name. */ |
059ec3d9 | 140 | |
94759fce JH |
141 | for (hptr = &header_list; (h = *hptr); hptr = &h->next) |
142 | if (header_testname(h, name, len, TRUE)) | |
143 | break; | |
059ec3d9 PH |
144 | |
145 | /* Handle the case where no header is found. To insert at the bottom, nothing | |
146 | needs to be done. */ | |
147 | ||
94759fce | 148 | if (!h) |
059ec3d9 PH |
149 | { |
150 | if (topnot) | |
151 | { | |
152 | hptr = &header_list; | |
153 | h = header_list; | |
154 | } | |
155 | } | |
156 | ||
157 | /* Handle the case where a header is found. Check for more if "after" is | |
158 | true. In this case, we want to include deleted headers in the block. */ | |
159 | ||
160 | else if (after) | |
059ec3d9 PH |
161 | for (;;) |
162 | { | |
94759fce | 163 | if (!h->next || !header_testname(h, name, len, FALSE)) break; |
dca6d121 | 164 | hptr = &h->next; |
059ec3d9 PH |
165 | h = h->next; |
166 | } | |
059ec3d9 PH |
167 | } |
168 | ||
169 | /* Loop for multiple header lines, taking care about continuations. At this | |
170 | point, we have hptr pointing to the link field that will point to the new | |
171 | header, and h containing the following header, or NULL. */ | |
172 | ||
f3ebb786 | 173 | for (p = q = gs.s; *p; p = q) |
059ec3d9 PH |
174 | { |
175 | for (;;) | |
176 | { | |
177 | q = Ustrchr(q, '\n'); | |
94759fce | 178 | if (!q) q = p + Ustrlen(p); |
059ec3d9 PH |
179 | if (*(++q) != ' ' && *q != '\t') break; |
180 | } | |
181 | ||
f3ebb786 | 182 | new = store_get(sizeof(header_line), FALSE); |
059ec3d9 PH |
183 | new->text = string_copyn(p, q - p); |
184 | new->slen = q - p; | |
185 | new->type = type; | |
186 | new->next = h; | |
187 | ||
188 | *hptr = new; | |
dca6d121 | 189 | hptr = &new->next; |
059ec3d9 | 190 | |
94759fce | 191 | if (!h) header_last = new; |
059ec3d9 | 192 | } |
049782c0 | 193 | return new; |
059ec3d9 PH |
194 | } |
195 | ||
196 | ||
197 | /************************************************* | |
198 | * Add new header anywhere in the chain * | |
199 | *************************************************/ | |
200 | ||
201 | /* This is an external interface to header_add_backend(). | |
202 | ||
203 | Arguments: | |
204 | after TRUE for "after", FALSE for "before" | |
205 | name name if adding at a specific header, else NULL | |
206 | topnot TRUE to add at top if no header found | |
207 | type Exim header type character (htype_something) | |
208 | format sprintf format | |
209 | ... format arguments | |
210 | ||
049782c0 | 211 | Returns: pointer to header struct added |
059ec3d9 PH |
212 | */ |
213 | ||
049782c0 JH |
214 | header_line * |
215 | header_add_at_position_internal(BOOL after, uschar *name, BOOL topnot, int type, | |
1ba28e2b | 216 | const char *format, ...) |
059ec3d9 | 217 | { |
049782c0 | 218 | header_line * h; |
059ec3d9 PH |
219 | va_list ap; |
220 | va_start(ap, format); | |
049782c0 | 221 | h = header_add_backend(after, name, topnot, type, format, ap); |
059ec3d9 | 222 | va_end(ap); |
049782c0 | 223 | return h; |
059ec3d9 PH |
224 | } |
225 | ||
226 | ||
049782c0 JH |
227 | /* Documented external i/f for local_scan */ |
228 | void | |
229 | header_add_at_position(BOOL after, uschar *name, BOOL topnot, int type, | |
230 | const char *format, ...) | |
231 | { | |
049782c0 JH |
232 | va_list ap; |
233 | va_start(ap, format); | |
234 | (void) header_add_backend(after, name, topnot, type, format, ap); | |
235 | va_end(ap); | |
236 | } | |
059ec3d9 PH |
237 | |
238 | /************************************************* | |
239 | * Add new header on end of chain * | |
240 | *************************************************/ | |
241 | ||
242 | /* This is now a convenience interface to header_add_backend(). | |
243 | ||
244 | Arguments: | |
245 | type Exim header type character | |
246 | format sprintf format | |
247 | ... arguments for the format | |
248 | ||
249 | Returns: nothing | |
250 | */ | |
251 | ||
252 | void | |
1ba28e2b | 253 | header_add(int type, const char *format, ...) |
059ec3d9 PH |
254 | { |
255 | va_list ap; | |
256 | va_start(ap, format); | |
049782c0 | 257 | (void) header_add_backend(TRUE, NULL, FALSE, type, format, ap); |
059ec3d9 PH |
258 | va_end(ap); |
259 | } | |
260 | ||
261 | ||
262 | ||
263 | /************************************************* | |
264 | * Remove (mark as old) a header * | |
265 | *************************************************/ | |
266 | ||
267 | /* This function is used by the filter code; it is also exported in the | |
268 | local_scan() API. If no header is found, the function does nothing. | |
269 | ||
270 | Arguments: | |
271 | occ the occurrence number for multiply-defined headers | |
272 | <= 0 means "all"; deleted headers are not counted | |
273 | name the header name | |
274 | ||
275 | Returns: nothing | |
276 | */ | |
277 | ||
278 | void | |
1ba28e2b | 279 | header_remove(int occ, const uschar *name) |
059ec3d9 | 280 | { |
059ec3d9 PH |
281 | int hcount = 0; |
282 | int len = Ustrlen(name); | |
d7978c0f | 283 | for (header_line * h = header_list; h; h = h->next) |
059ec3d9 PH |
284 | if (header_testname(h, name, len, TRUE) && (occ <= 0 || ++hcount == occ)) |
285 | { | |
286 | h->type = htype_old; | |
287 | if (occ > 0) return; | |
288 | } | |
059ec3d9 PH |
289 | } |
290 | ||
291 | ||
292 | ||
293 | /************************************************* | |
294 | * Check the name of a header * | |
295 | *************************************************/ | |
296 | ||
297 | /* This function scans a table of header field names that Exim recognizes, and | |
298 | returns the identification of a match. If "resent" is true, the header is known | |
299 | to start with "resent-". In that case, the function matches only those fields | |
300 | that are allowed to appear with resent- in front of them. | |
301 | ||
302 | Arguments: | |
303 | h points to the header line | |
304 | is_resent TRUE if the name starts "Resent-" | |
305 | ||
306 | Returns: One of the htype_ enum values, identifying the header | |
307 | */ | |
308 | ||
309 | int | |
310 | header_checkname(header_line *h, BOOL is_resent) | |
311 | { | |
312 | uschar *text = h->text; | |
313 | header_name *bot = header_names; | |
314 | header_name *top = header_names + header_names_size; | |
315 | ||
316 | if (is_resent) text += 7; | |
317 | ||
318 | while (bot < top) | |
319 | { | |
320 | header_name *mid = bot + (top - bot)/2; | |
321 | int c = strncmpic(text, mid->name, mid->len); | |
322 | ||
323 | if (c == 0) | |
324 | { | |
137ae145 JH |
325 | uschar * s = text + mid->len; |
326 | if (Uskip_whitespace(&s) == ':') | |
059ec3d9 PH |
327 | return (!is_resent || mid->allow_resent)? mid->htype : htype_other; |
328 | c = 1; | |
329 | } | |
330 | ||
331 | if (c > 0) bot = mid + 1; else top = mid; | |
332 | } | |
333 | ||
334 | return htype_other; | |
335 | } | |
336 | ||
337 | ||
338 | /************************************************* | |
339 | * Scan a header for certain strings * | |
340 | *************************************************/ | |
341 | ||
342 | /* This function is used for the "personal" test. It scans a particular header | |
343 | line for any one of a number of strings, matched caselessly either as plain | |
344 | strings, or as regular expressions. If the header line contains a list of | |
345 | addresses, each match is applied only to the operative part of each address in | |
346 | the header, and non-regular expressions must be exact matches. | |
347 | ||
348 | The patterns can be provided either as a chain of string_item structures, or | |
349 | inline in the argument list, or both. If there is more than one header of the | |
350 | same name, they are all searched. | |
351 | ||
352 | Arguments: | |
353 | name header name, including the trailing colon | |
354 | has_addresses TRUE if the header contains a list of addresses | |
355 | cond value to return if the header contains any of the strings | |
356 | strings points to a chain of string_item blocks | |
357 | count number of inline strings | |
358 | ... the inline strings | |
359 | ||
360 | Returns: cond if the header exists and contains one of the strings; | |
361 | otherwise !cond | |
362 | */ | |
363 | ||
364 | ||
365 | /* First we have a local subroutine to handle a single pattern */ | |
366 | ||
367 | static BOOL | |
368 | one_pattern_match(uschar *name, int slen, BOOL has_addresses, uschar *pattern) | |
369 | { | |
370 | BOOL yield = FALSE; | |
059ec3d9 PH |
371 | const pcre *re = NULL; |
372 | ||
373 | /* If the pattern is a regex, compile it. Bomb out if compiling fails; these | |
374 | patterns are all constructed internally and should be valid. */ | |
375 | ||
376 | if (*pattern == '^') re = regex_must_compile(pattern, TRUE, FALSE); | |
377 | ||
378 | /* Scan for the required header(s) and scan each one */ | |
379 | ||
d7978c0f | 380 | for (header_line * h = header_list; !yield && h; h = h->next) |
059ec3d9 PH |
381 | { |
382 | if (h->type == htype_old || slen > h->slen || | |
383 | strncmpic(name, h->text, slen) != 0) | |
384 | continue; | |
385 | ||
386 | /* If the header is a list of addresses, extract each one in turn, and scan | |
387 | it. A non-regex scan must be an exact match for the address. */ | |
388 | ||
389 | if (has_addresses) | |
390 | { | |
391 | uschar *s = h->text + slen; | |
392 | ||
d7978c0f | 393 | while (!yield && *s) |
059ec3d9 PH |
394 | { |
395 | uschar *error, *next; | |
396 | uschar *e = parse_find_address_end(s, FALSE); | |
397 | int terminator = *e; | |
398 | int start, end, domain; | |
399 | ||
400 | /* Temporarily terminate the string at the address end while extracting | |
401 | the operative address within. */ | |
402 | ||
403 | *e = 0; | |
404 | next = parse_extract_address(s, &error, &start, &end, &domain, FALSE); | |
405 | *e = terminator; | |
406 | ||
407 | /* Move on, ready for the next address */ | |
408 | ||
409 | s = e; | |
410 | if (*s == ',') s++; | |
411 | ||
412 | /* If there is some kind of syntax error, just give up on this header | |
413 | line. */ | |
414 | ||
5fcc791a | 415 | if (!next) break; |
059ec3d9 PH |
416 | |
417 | /* Otherwise, test for the pattern; a non-regex must be an exact match */ | |
418 | ||
5fcc791a JH |
419 | yield = !re |
420 | ? (strcmpic(next, pattern) == 0) | |
421 | : (pcre_exec(re, NULL, CS next, Ustrlen(next), 0, PCRE_EOPT, NULL, 0) | |
059ec3d9 PH |
422 | >= 0); |
423 | } | |
424 | } | |
425 | ||
426 | /* For headers that are not lists of addresses, scan the entire header line, | |
427 | and just require "contains" for non-regex patterns. */ | |
428 | ||
429 | else | |
430 | { | |
431 | yield = (re == NULL)? | |
432 | (strstric(h->text, pattern, FALSE) != NULL) | |
433 | : | |
434 | (pcre_exec(re, NULL, CS h->text, h->slen, 0, PCRE_EOPT, NULL, 0) >= 0); | |
435 | } | |
436 | } | |
437 | ||
438 | return yield; | |
439 | } | |
440 | ||
441 | ||
442 | /* The externally visible interface */ | |
443 | ||
444 | BOOL | |
445 | header_match(uschar *name, BOOL has_addresses, BOOL cond, string_item *strings, | |
446 | int count, ...) | |
447 | { | |
448 | va_list ap; | |
059ec3d9 PH |
449 | int slen = Ustrlen(name); |
450 | ||
d7978c0f JH |
451 | for (string_item * s = strings; s; s = s->next) |
452 | if (one_pattern_match(name, slen, has_addresses, s->text)) | |
453 | return cond; | |
059ec3d9 PH |
454 | |
455 | va_start(ap, count); | |
d7978c0f | 456 | for (int i = 0; i < count; i++) |
059ec3d9 | 457 | if (one_pattern_match(name, slen, has_addresses, va_arg(ap, uschar *))) |
cb570b5e JH |
458 | { |
459 | va_end(ap); | |
059ec3d9 | 460 | return cond; |
cb570b5e | 461 | } |
059ec3d9 PH |
462 | va_end(ap); |
463 | ||
464 | return !cond; | |
465 | } | |
466 | ||
467 | /* End of header.c */ |