Commit | Line | Data |
---|---|---|
059ec3d9 PH |
1 | /************************************************* |
2 | * Exim - an Internet mail transport agent * | |
3 | *************************************************/ | |
4 | ||
0a49a7a4 | 5 | /* Copyright (c) University of Cambridge 1995 - 2009 */ |
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 | ||
89 | Returns: nothing | |
90 | */ | |
91 | ||
92 | static void | |
93 | header_add_backend(BOOL after, uschar *name, BOOL topnot, int type, | |
1ba28e2b | 94 | const char *format, va_list ap) |
059ec3d9 PH |
95 | { |
96 | header_line *h, *new; | |
97 | header_line **hptr; | |
98 | ||
99 | uschar *p, *q; | |
100 | uschar buffer[HEADER_ADD_BUFFER_SIZE]; | |
101 | ||
102 | if (header_last == NULL) return; | |
103 | ||
104 | if (!string_vformat(buffer, sizeof(buffer), format, ap)) | |
105 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "string too long in header_add: " | |
106 | "%.100s ...", buffer); | |
107 | ||
108 | /* Find where to insert this header */ | |
109 | ||
110 | if (name == NULL) | |
111 | { | |
112 | if (after) | |
113 | { | |
114 | hptr = &(header_last->next); | |
115 | h = NULL; | |
116 | } | |
117 | else | |
118 | { | |
119 | hptr = &header_list; | |
5eb690a1 NM |
120 | |
121 | /* header_list->text can be NULL if we get here between when the new | |
122 | received header is allocated and when it is acutally filled in. We want | |
123 | that header to be first, so skip it for now. */ | |
124 | ||
125 | if (header_list->text == NULL) | |
126 | hptr = &header_list->next; | |
127 | h = *hptr; | |
059ec3d9 PH |
128 | } |
129 | } | |
130 | ||
131 | else | |
132 | { | |
133 | int len = Ustrlen(name); | |
134 | ||
135 | /* Find the first non-deleted header witht the correct name. */ | |
136 | ||
137 | for (hptr = &header_list; (h = *hptr) != NULL; hptr = &(h->next)) | |
138 | { | |
139 | if (header_testname(h, name, len, TRUE)) break; | |
140 | } | |
141 | ||
142 | /* Handle the case where no header is found. To insert at the bottom, nothing | |
143 | needs to be done. */ | |
144 | ||
145 | if (h == NULL) | |
146 | { | |
147 | if (topnot) | |
148 | { | |
149 | hptr = &header_list; | |
150 | h = header_list; | |
151 | } | |
152 | } | |
153 | ||
154 | /* Handle the case where a header is found. Check for more if "after" is | |
155 | true. In this case, we want to include deleted headers in the block. */ | |
156 | ||
157 | else if (after) | |
158 | { | |
159 | for (;;) | |
160 | { | |
161 | if (h->next == NULL || !header_testname(h, name, len, FALSE)) break; | |
162 | hptr = &(h->next); | |
163 | h = h->next; | |
164 | } | |
165 | } | |
166 | } | |
167 | ||
168 | /* Loop for multiple header lines, taking care about continuations. At this | |
169 | point, we have hptr pointing to the link field that will point to the new | |
170 | header, and h containing the following header, or NULL. */ | |
171 | ||
172 | for (p = q = buffer; *p != 0; ) | |
173 | { | |
174 | for (;;) | |
175 | { | |
176 | q = Ustrchr(q, '\n'); | |
177 | if (q == NULL) q = p + Ustrlen(p); | |
178 | if (*(++q) != ' ' && *q != '\t') break; | |
179 | } | |
180 | ||
181 | new = store_get(sizeof(header_line)); | |
182 | new->text = string_copyn(p, q - p); | |
183 | new->slen = q - p; | |
184 | new->type = type; | |
185 | new->next = h; | |
186 | ||
187 | *hptr = new; | |
188 | hptr = &(new->next); | |
189 | ||
190 | if (h == NULL) header_last = new; | |
191 | p = q; | |
192 | } | |
193 | } | |
194 | ||
195 | ||
196 | /************************************************* | |
197 | * Add new header anywhere in the chain * | |
198 | *************************************************/ | |
199 | ||
200 | /* This is an external interface to header_add_backend(). | |
201 | ||
202 | Arguments: | |
203 | after TRUE for "after", FALSE for "before" | |
204 | name name if adding at a specific header, else NULL | |
205 | topnot TRUE to add at top if no header found | |
206 | type Exim header type character (htype_something) | |
207 | format sprintf format | |
208 | ... format arguments | |
209 | ||
210 | Returns: nothing | |
211 | */ | |
212 | ||
213 | void | |
214 | header_add_at_position(BOOL after, uschar *name, BOOL topnot, int type, | |
1ba28e2b | 215 | const char *format, ...) |
059ec3d9 PH |
216 | { |
217 | va_list ap; | |
218 | va_start(ap, format); | |
219 | header_add_backend(after, name, topnot, type, format, ap); | |
220 | va_end(ap); | |
221 | } | |
222 | ||
223 | ||
224 | ||
225 | /************************************************* | |
226 | * Add new header on end of chain * | |
227 | *************************************************/ | |
228 | ||
229 | /* This is now a convenience interface to header_add_backend(). | |
230 | ||
231 | Arguments: | |
232 | type Exim header type character | |
233 | format sprintf format | |
234 | ... arguments for the format | |
235 | ||
236 | Returns: nothing | |
237 | */ | |
238 | ||
239 | void | |
1ba28e2b | 240 | header_add(int type, const char *format, ...) |
059ec3d9 PH |
241 | { |
242 | va_list ap; | |
243 | va_start(ap, format); | |
244 | header_add_backend(TRUE, NULL, FALSE, type, format, ap); | |
245 | va_end(ap); | |
246 | } | |
247 | ||
248 | ||
249 | ||
250 | /************************************************* | |
251 | * Remove (mark as old) a header * | |
252 | *************************************************/ | |
253 | ||
254 | /* This function is used by the filter code; it is also exported in the | |
255 | local_scan() API. If no header is found, the function does nothing. | |
256 | ||
257 | Arguments: | |
258 | occ the occurrence number for multiply-defined headers | |
259 | <= 0 means "all"; deleted headers are not counted | |
260 | name the header name | |
261 | ||
262 | Returns: nothing | |
263 | */ | |
264 | ||
265 | void | |
1ba28e2b | 266 | header_remove(int occ, const uschar *name) |
059ec3d9 PH |
267 | { |
268 | header_line *h; | |
269 | int hcount = 0; | |
270 | int len = Ustrlen(name); | |
271 | for (h = header_list; h != NULL; h = h->next) | |
272 | { | |
273 | if (header_testname(h, name, len, TRUE) && (occ <= 0 || ++hcount == occ)) | |
274 | { | |
275 | h->type = htype_old; | |
276 | if (occ > 0) return; | |
277 | } | |
278 | } | |
279 | } | |
280 | ||
281 | ||
282 | ||
283 | /************************************************* | |
284 | * Check the name of a header * | |
285 | *************************************************/ | |
286 | ||
287 | /* This function scans a table of header field names that Exim recognizes, and | |
288 | returns the identification of a match. If "resent" is true, the header is known | |
289 | to start with "resent-". In that case, the function matches only those fields | |
290 | that are allowed to appear with resent- in front of them. | |
291 | ||
292 | Arguments: | |
293 | h points to the header line | |
294 | is_resent TRUE if the name starts "Resent-" | |
295 | ||
296 | Returns: One of the htype_ enum values, identifying the header | |
297 | */ | |
298 | ||
299 | int | |
300 | header_checkname(header_line *h, BOOL is_resent) | |
301 | { | |
302 | uschar *text = h->text; | |
303 | header_name *bot = header_names; | |
304 | header_name *top = header_names + header_names_size; | |
305 | ||
306 | if (is_resent) text += 7; | |
307 | ||
308 | while (bot < top) | |
309 | { | |
310 | header_name *mid = bot + (top - bot)/2; | |
311 | int c = strncmpic(text, mid->name, mid->len); | |
312 | ||
313 | if (c == 0) | |
314 | { | |
315 | uschar *s = text + mid->len; | |
316 | while (isspace(*s)) s++; | |
317 | if (*s == ':') | |
318 | return (!is_resent || mid->allow_resent)? mid->htype : htype_other; | |
319 | c = 1; | |
320 | } | |
321 | ||
322 | if (c > 0) bot = mid + 1; else top = mid; | |
323 | } | |
324 | ||
325 | return htype_other; | |
326 | } | |
327 | ||
328 | ||
329 | /************************************************* | |
330 | * Scan a header for certain strings * | |
331 | *************************************************/ | |
332 | ||
333 | /* This function is used for the "personal" test. It scans a particular header | |
334 | line for any one of a number of strings, matched caselessly either as plain | |
335 | strings, or as regular expressions. If the header line contains a list of | |
336 | addresses, each match is applied only to the operative part of each address in | |
337 | the header, and non-regular expressions must be exact matches. | |
338 | ||
339 | The patterns can be provided either as a chain of string_item structures, or | |
340 | inline in the argument list, or both. If there is more than one header of the | |
341 | same name, they are all searched. | |
342 | ||
343 | Arguments: | |
344 | name header name, including the trailing colon | |
345 | has_addresses TRUE if the header contains a list of addresses | |
346 | cond value to return if the header contains any of the strings | |
347 | strings points to a chain of string_item blocks | |
348 | count number of inline strings | |
349 | ... the inline strings | |
350 | ||
351 | Returns: cond if the header exists and contains one of the strings; | |
352 | otherwise !cond | |
353 | */ | |
354 | ||
355 | ||
356 | /* First we have a local subroutine to handle a single pattern */ | |
357 | ||
358 | static BOOL | |
359 | one_pattern_match(uschar *name, int slen, BOOL has_addresses, uschar *pattern) | |
360 | { | |
361 | BOOL yield = FALSE; | |
362 | header_line *h; | |
363 | const pcre *re = NULL; | |
364 | ||
365 | /* If the pattern is a regex, compile it. Bomb out if compiling fails; these | |
366 | patterns are all constructed internally and should be valid. */ | |
367 | ||
368 | if (*pattern == '^') re = regex_must_compile(pattern, TRUE, FALSE); | |
369 | ||
370 | /* Scan for the required header(s) and scan each one */ | |
371 | ||
372 | for (h = header_list; !yield && h != NULL; h = h->next) | |
373 | { | |
374 | if (h->type == htype_old || slen > h->slen || | |
375 | strncmpic(name, h->text, slen) != 0) | |
376 | continue; | |
377 | ||
378 | /* If the header is a list of addresses, extract each one in turn, and scan | |
379 | it. A non-regex scan must be an exact match for the address. */ | |
380 | ||
381 | if (has_addresses) | |
382 | { | |
383 | uschar *s = h->text + slen; | |
384 | ||
385 | while (!yield && *s != 0) | |
386 | { | |
387 | uschar *error, *next; | |
388 | uschar *e = parse_find_address_end(s, FALSE); | |
389 | int terminator = *e; | |
390 | int start, end, domain; | |
391 | ||
392 | /* Temporarily terminate the string at the address end while extracting | |
393 | the operative address within. */ | |
394 | ||
395 | *e = 0; | |
396 | next = parse_extract_address(s, &error, &start, &end, &domain, FALSE); | |
397 | *e = terminator; | |
398 | ||
399 | /* Move on, ready for the next address */ | |
400 | ||
401 | s = e; | |
402 | if (*s == ',') s++; | |
403 | ||
404 | /* If there is some kind of syntax error, just give up on this header | |
405 | line. */ | |
406 | ||
407 | if (next == NULL) break; | |
408 | ||
409 | /* Otherwise, test for the pattern; a non-regex must be an exact match */ | |
410 | ||
411 | yield = (re == NULL)? | |
412 | (strcmpic(next, pattern) == 0) | |
413 | : | |
414 | (pcre_exec(re, NULL, CS next, Ustrlen(next), 0, PCRE_EOPT, NULL, 0) | |
415 | >= 0); | |
416 | } | |
417 | } | |
418 | ||
419 | /* For headers that are not lists of addresses, scan the entire header line, | |
420 | and just require "contains" for non-regex patterns. */ | |
421 | ||
422 | else | |
423 | { | |
424 | yield = (re == NULL)? | |
425 | (strstric(h->text, pattern, FALSE) != NULL) | |
426 | : | |
427 | (pcre_exec(re, NULL, CS h->text, h->slen, 0, PCRE_EOPT, NULL, 0) >= 0); | |
428 | } | |
429 | } | |
430 | ||
431 | return yield; | |
432 | } | |
433 | ||
434 | ||
435 | /* The externally visible interface */ | |
436 | ||
437 | BOOL | |
438 | header_match(uschar *name, BOOL has_addresses, BOOL cond, string_item *strings, | |
439 | int count, ...) | |
440 | { | |
441 | va_list ap; | |
442 | string_item *s; | |
443 | int i; | |
444 | int slen = Ustrlen(name); | |
445 | ||
446 | for (s = strings; s != NULL; s = s->next) | |
447 | { | |
448 | if (one_pattern_match(name, slen, has_addresses, s->text)) return cond; | |
449 | } | |
450 | ||
451 | va_start(ap, count); | |
452 | for (i = 0; i < count; i++) | |
453 | { | |
454 | if (one_pattern_match(name, slen, has_addresses, va_arg(ap, uschar *))) | |
455 | return cond; | |
456 | } | |
457 | va_end(ap); | |
458 | ||
459 | return !cond; | |
460 | } | |
461 | ||
462 | /* End of header.c */ |