Commit | Line | Data |
---|---|---|
420a0d19 CE |
1 | /************************************************* |
2 | * Exim - an Internet mail transport agent * | |
3 | *************************************************/ | |
4 | ||
2ea97746 | 5 | /* Copyright (c) University of Cambridge 1995 - 2016 */ |
420a0d19 CE |
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 | |
31 | header_testname(header_line *h, const uschar *name, int len, BOOL notdel) | |
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 | ||
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 | |
47 | header_testname_incomplete(header_line *h, const uschar *name, | |
48 | int len, BOOL notdel) | |
49 | { | |
50 | if (h->type == '*' && notdel) return FALSE; | |
51 | if (h->text == NULL || strncmpic(h->text, name, len) != 0) return FALSE; | |
52 | return TRUE; | |
53 | } | |
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 | ||
89 | Returns: nothing | |
90 | */ | |
91 | ||
92 | static void | |
93 | header_add_backend(BOOL after, uschar *name, BOOL topnot, int type, | |
94 | const char *format, va_list ap) | |
95 | { | |
96 | header_line *h, *new; | |
97 | header_line **hptr; | |
98 | ||
99 | uschar *p, *q; | |
100 | uschar buffer[HEADER_ADD_BUFFER_SIZE]; | |
2ea97746 | 101 | gstring gs = { .size = HEADER_ADD_BUFFER_SIZE, .ptr = 0, .s = buffer }; |
420a0d19 | 102 | |
2ea97746 | 103 | if (!header_last) return; |
420a0d19 | 104 | |
2ea97746 | 105 | if (!string_vformat(&gs, FALSE, format, ap)) |
420a0d19 | 106 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "string too long in header_add: " |
2ea97746 CE |
107 | "%.100s ...", string_from_gstring(&gs)); |
108 | string_from_gstring(&gs); | |
420a0d19 CE |
109 | |
110 | /* Find where to insert this header */ | |
111 | ||
2ea97746 | 112 | if (!name) |
420a0d19 CE |
113 | { |
114 | if (after) | |
115 | { | |
116 | hptr = &(header_last->next); | |
117 | h = NULL; | |
118 | } | |
119 | else | |
120 | { | |
121 | hptr = &header_list; | |
122 | ||
123 | /* header_list->text can be NULL if we get here between when the new | |
2ea97746 | 124 | received header is allocated and when it is actually filled in. We want |
420a0d19 CE |
125 | that header to be first, so skip it for now. */ |
126 | ||
2ea97746 | 127 | if (!header_list->text) |
420a0d19 CE |
128 | hptr = &header_list->next; |
129 | h = *hptr; | |
130 | } | |
131 | } | |
132 | ||
133 | else | |
134 | { | |
135 | int len = Ustrlen(name); | |
136 | ||
2ea97746 | 137 | /* Find the first non-deleted header with the correct name. */ |
420a0d19 | 138 | |
2ea97746 CE |
139 | for (hptr = &header_list; (h = *hptr); hptr = &h->next) |
140 | if (header_testname(h, name, len, TRUE)) | |
141 | break; | |
420a0d19 CE |
142 | |
143 | /* Handle the case where no header is found. To insert at the bottom, nothing | |
144 | needs to be done. */ | |
145 | ||
2ea97746 | 146 | if (!h) |
420a0d19 CE |
147 | { |
148 | if (topnot) | |
149 | { | |
150 | hptr = &header_list; | |
151 | h = header_list; | |
152 | } | |
153 | } | |
154 | ||
155 | /* Handle the case where a header is found. Check for more if "after" is | |
156 | true. In this case, we want to include deleted headers in the block. */ | |
157 | ||
158 | else if (after) | |
420a0d19 CE |
159 | for (;;) |
160 | { | |
2ea97746 | 161 | if (!h->next || !header_testname(h, name, len, FALSE)) break; |
420a0d19 CE |
162 | hptr = &(h->next); |
163 | h = h->next; | |
164 | } | |
420a0d19 CE |
165 | } |
166 | ||
167 | /* Loop for multiple header lines, taking care about continuations. At this | |
168 | point, we have hptr pointing to the link field that will point to the new | |
169 | header, and h containing the following header, or NULL. */ | |
170 | ||
171 | for (p = q = buffer; *p != 0; ) | |
172 | { | |
173 | for (;;) | |
174 | { | |
175 | q = Ustrchr(q, '\n'); | |
2ea97746 | 176 | if (!q) q = p + Ustrlen(p); |
420a0d19 CE |
177 | if (*(++q) != ' ' && *q != '\t') break; |
178 | } | |
179 | ||
180 | new = store_get(sizeof(header_line)); | |
181 | new->text = string_copyn(p, q - p); | |
182 | new->slen = q - p; | |
183 | new->type = type; | |
184 | new->next = h; | |
185 | ||
186 | *hptr = new; | |
187 | hptr = &(new->next); | |
188 | ||
2ea97746 | 189 | if (!h) header_last = new; |
420a0d19 CE |
190 | p = q; |
191 | } | |
192 | } | |
193 | ||
194 | ||
195 | /************************************************* | |
196 | * Add new header anywhere in the chain * | |
197 | *************************************************/ | |
198 | ||
199 | /* This is an external interface to header_add_backend(). | |
200 | ||
201 | Arguments: | |
202 | after TRUE for "after", FALSE for "before" | |
203 | name name if adding at a specific header, else NULL | |
204 | topnot TRUE to add at top if no header found | |
205 | type Exim header type character (htype_something) | |
206 | format sprintf format | |
207 | ... format arguments | |
208 | ||
209 | Returns: nothing | |
210 | */ | |
211 | ||
212 | void | |
213 | header_add_at_position(BOOL after, uschar *name, BOOL topnot, int type, | |
214 | const char *format, ...) | |
215 | { | |
216 | va_list ap; | |
217 | va_start(ap, format); | |
218 | header_add_backend(after, name, topnot, type, format, ap); | |
219 | va_end(ap); | |
220 | } | |
221 | ||
222 | ||
223 | ||
224 | /************************************************* | |
225 | * Add new header on end of chain * | |
226 | *************************************************/ | |
227 | ||
228 | /* This is now a convenience interface to header_add_backend(). | |
229 | ||
230 | Arguments: | |
231 | type Exim header type character | |
232 | format sprintf format | |
233 | ... arguments for the format | |
234 | ||
235 | Returns: nothing | |
236 | */ | |
237 | ||
238 | void | |
239 | header_add(int type, const char *format, ...) | |
240 | { | |
241 | va_list ap; | |
242 | va_start(ap, format); | |
243 | header_add_backend(TRUE, NULL, FALSE, type, format, ap); | |
244 | va_end(ap); | |
245 | } | |
246 | ||
247 | ||
248 | ||
249 | /************************************************* | |
250 | * Remove (mark as old) a header * | |
251 | *************************************************/ | |
252 | ||
253 | /* This function is used by the filter code; it is also exported in the | |
254 | local_scan() API. If no header is found, the function does nothing. | |
255 | ||
256 | Arguments: | |
257 | occ the occurrence number for multiply-defined headers | |
258 | <= 0 means "all"; deleted headers are not counted | |
259 | name the header name | |
260 | ||
261 | Returns: nothing | |
262 | */ | |
263 | ||
264 | void | |
265 | header_remove(int occ, const uschar *name) | |
266 | { | |
267 | header_line *h; | |
268 | int hcount = 0; | |
269 | int len = Ustrlen(name); | |
270 | for (h = header_list; h != NULL; h = h->next) | |
271 | { | |
272 | if (header_testname(h, name, len, TRUE) && (occ <= 0 || ++hcount == occ)) | |
273 | { | |
274 | h->type = htype_old; | |
275 | if (occ > 0) return; | |
276 | } | |
277 | } | |
278 | } | |
279 | ||
280 | ||
281 | ||
282 | /************************************************* | |
283 | * Check the name of a header * | |
284 | *************************************************/ | |
285 | ||
286 | /* This function scans a table of header field names that Exim recognizes, and | |
287 | returns the identification of a match. If "resent" is true, the header is known | |
288 | to start with "resent-". In that case, the function matches only those fields | |
289 | that are allowed to appear with resent- in front of them. | |
290 | ||
291 | Arguments: | |
292 | h points to the header line | |
293 | is_resent TRUE if the name starts "Resent-" | |
294 | ||
295 | Returns: One of the htype_ enum values, identifying the header | |
296 | */ | |
297 | ||
298 | int | |
299 | header_checkname(header_line *h, BOOL is_resent) | |
300 | { | |
301 | uschar *text = h->text; | |
302 | header_name *bot = header_names; | |
303 | header_name *top = header_names + header_names_size; | |
304 | ||
305 | if (is_resent) text += 7; | |
306 | ||
307 | while (bot < top) | |
308 | { | |
309 | header_name *mid = bot + (top - bot)/2; | |
310 | int c = strncmpic(text, mid->name, mid->len); | |
311 | ||
312 | if (c == 0) | |
313 | { | |
314 | uschar *s = text + mid->len; | |
315 | while (isspace(*s)) s++; | |
316 | if (*s == ':') | |
317 | return (!is_resent || mid->allow_resent)? mid->htype : htype_other; | |
318 | c = 1; | |
319 | } | |
320 | ||
321 | if (c > 0) bot = mid + 1; else top = mid; | |
322 | } | |
323 | ||
324 | return htype_other; | |
325 | } | |
326 | ||
327 | ||
328 | /************************************************* | |
329 | * Scan a header for certain strings * | |
330 | *************************************************/ | |
331 | ||
332 | /* This function is used for the "personal" test. It scans a particular header | |
333 | line for any one of a number of strings, matched caselessly either as plain | |
334 | strings, or as regular expressions. If the header line contains a list of | |
335 | addresses, each match is applied only to the operative part of each address in | |
336 | the header, and non-regular expressions must be exact matches. | |
337 | ||
338 | The patterns can be provided either as a chain of string_item structures, or | |
339 | inline in the argument list, or both. If there is more than one header of the | |
340 | same name, they are all searched. | |
341 | ||
342 | Arguments: | |
343 | name header name, including the trailing colon | |
344 | has_addresses TRUE if the header contains a list of addresses | |
345 | cond value to return if the header contains any of the strings | |
346 | strings points to a chain of string_item blocks | |
347 | count number of inline strings | |
348 | ... the inline strings | |
349 | ||
350 | Returns: cond if the header exists and contains one of the strings; | |
351 | otherwise !cond | |
352 | */ | |
353 | ||
354 | ||
355 | /* First we have a local subroutine to handle a single pattern */ | |
356 | ||
357 | static BOOL | |
358 | one_pattern_match(uschar *name, int slen, BOOL has_addresses, uschar *pattern) | |
359 | { | |
360 | BOOL yield = FALSE; | |
361 | header_line *h; | |
362 | const pcre *re = NULL; | |
363 | ||
364 | /* If the pattern is a regex, compile it. Bomb out if compiling fails; these | |
365 | patterns are all constructed internally and should be valid. */ | |
366 | ||
367 | if (*pattern == '^') re = regex_must_compile(pattern, TRUE, FALSE); | |
368 | ||
369 | /* Scan for the required header(s) and scan each one */ | |
370 | ||
371 | for (h = header_list; !yield && h != NULL; h = h->next) | |
372 | { | |
373 | if (h->type == htype_old || slen > h->slen || | |
374 | strncmpic(name, h->text, slen) != 0) | |
375 | continue; | |
376 | ||
377 | /* If the header is a list of addresses, extract each one in turn, and scan | |
378 | it. A non-regex scan must be an exact match for the address. */ | |
379 | ||
380 | if (has_addresses) | |
381 | { | |
382 | uschar *s = h->text + slen; | |
383 | ||
384 | while (!yield && *s != 0) | |
385 | { | |
386 | uschar *error, *next; | |
387 | uschar *e = parse_find_address_end(s, FALSE); | |
388 | int terminator = *e; | |
389 | int start, end, domain; | |
390 | ||
391 | /* Temporarily terminate the string at the address end while extracting | |
392 | the operative address within. */ | |
393 | ||
394 | *e = 0; | |
395 | next = parse_extract_address(s, &error, &start, &end, &domain, FALSE); | |
396 | *e = terminator; | |
397 | ||
398 | /* Move on, ready for the next address */ | |
399 | ||
400 | s = e; | |
401 | if (*s == ',') s++; | |
402 | ||
403 | /* If there is some kind of syntax error, just give up on this header | |
404 | line. */ | |
405 | ||
406 | if (next == NULL) break; | |
407 | ||
408 | /* Otherwise, test for the pattern; a non-regex must be an exact match */ | |
409 | ||
410 | yield = (re == NULL)? | |
411 | (strcmpic(next, pattern) == 0) | |
412 | : | |
413 | (pcre_exec(re, NULL, CS next, Ustrlen(next), 0, PCRE_EOPT, NULL, 0) | |
414 | >= 0); | |
415 | } | |
416 | } | |
417 | ||
418 | /* For headers that are not lists of addresses, scan the entire header line, | |
419 | and just require "contains" for non-regex patterns. */ | |
420 | ||
421 | else | |
422 | { | |
423 | yield = (re == NULL)? | |
424 | (strstric(h->text, pattern, FALSE) != NULL) | |
425 | : | |
426 | (pcre_exec(re, NULL, CS h->text, h->slen, 0, PCRE_EOPT, NULL, 0) >= 0); | |
427 | } | |
428 | } | |
429 | ||
430 | return yield; | |
431 | } | |
432 | ||
433 | ||
434 | /* The externally visible interface */ | |
435 | ||
436 | BOOL | |
437 | header_match(uschar *name, BOOL has_addresses, BOOL cond, string_item *strings, | |
438 | int count, ...) | |
439 | { | |
440 | va_list ap; | |
441 | string_item *s; | |
442 | int i; | |
443 | int slen = Ustrlen(name); | |
444 | ||
445 | for (s = strings; s != NULL; s = s->next) | |
446 | { | |
447 | if (one_pattern_match(name, slen, has_addresses, s->text)) return cond; | |
448 | } | |
449 | ||
450 | va_start(ap, count); | |
451 | for (i = 0; i < count; i++) | |
420a0d19 | 452 | if (one_pattern_match(name, slen, has_addresses, va_arg(ap, uschar *))) |
2ea97746 CE |
453 | { |
454 | va_end(ap); | |
420a0d19 | 455 | return cond; |
2ea97746 | 456 | } |
420a0d19 CE |
457 | va_end(ap); |
458 | ||
459 | return !cond; | |
460 | } | |
461 | ||
462 | /* End of header.c */ |