1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2016 */
6 /* See the file NOTICE for conditions of use and distribution. */
12 /*************************************************
13 * Test a header for matching name *
14 *************************************************/
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
22 h points to the header
24 len the length of the name
25 notdel if TRUE, force FALSE for deleted headers
27 Returns: TRUE or FALSE
31 header_testname(header_line *h, const uschar *name, int len, BOOL notdel)
34 if (h->type == '*' && notdel) return FALSE;
35 if (h->text == NULL || strncmpic(h->text, name, len) != 0) return FALSE;
37 while (*tt == ' ' || *tt == '\t') tt++;
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. */
47 header_testname_incomplete(header_line *h, const uschar *name,
50 if (h->type == '*' && notdel) return FALSE;
51 if (h->text == NULL || strncmpic(h->text, name, len) != 0) return FALSE;
56 /*************************************************
57 * Add new header backend function *
58 *************************************************/
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.
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.
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"
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
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)
87 ap va_list value for format arguments
93 header_add_backend(BOOL after, uschar *name, BOOL topnot, int type,
94 const char *format, va_list ap)
100 uschar buffer[HEADER_ADD_BUFFER_SIZE];
102 if (!header_last) return;
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);
108 /* Find where to insert this header */
114 hptr = &(header_last->next);
121 /* header_list->text can be NULL if we get here between when the new
122 received header is allocated and when it is actually filled in. We want
123 that header to be first, so skip it for now. */
125 if (!header_list->text)
126 hptr = &header_list->next;
133 int len = Ustrlen(name);
135 /* Find the first non-deleted header with the correct name. */
137 for (hptr = &header_list; (h = *hptr); hptr = &h->next)
138 if (header_testname(h, name, len, TRUE))
141 /* Handle the case where no header is found. To insert at the bottom, nothing
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. */
159 if (!h->next || !header_testname(h, name, len, FALSE)) break;
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. */
169 for (p = q = buffer; *p != 0; )
173 q = Ustrchr(q, '\n');
174 if (!q) q = p + Ustrlen(p);
175 if (*(++q) != ' ' && *q != '\t') break;
178 new = store_get(sizeof(header_line));
179 new->text = string_copyn(p, q - p);
187 if (!h) header_last = new;
193 /*************************************************
194 * Add new header anywhere in the chain *
195 *************************************************/
197 /* This is an external interface to header_add_backend().
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
211 header_add_at_position(BOOL after, uschar *name, BOOL topnot, int type,
212 const char *format, ...)
215 va_start(ap, format);
216 header_add_backend(after, name, topnot, type, format, ap);
222 /*************************************************
223 * Add new header on end of chain *
224 *************************************************/
226 /* This is now a convenience interface to header_add_backend().
229 type Exim header type character
230 format sprintf format
231 ... arguments for the format
237 header_add(int type, const char *format, ...)
240 va_start(ap, format);
241 header_add_backend(TRUE, NULL, FALSE, type, format, ap);
247 /*************************************************
248 * Remove (mark as old) a header *
249 *************************************************/
251 /* This function is used by the filter code; it is also exported in the
252 local_scan() API. If no header is found, the function does nothing.
255 occ the occurrence number for multiply-defined headers
256 <= 0 means "all"; deleted headers are not counted
263 header_remove(int occ, const uschar *name)
267 int len = Ustrlen(name);
268 for (h = header_list; h != NULL; h = h->next)
270 if (header_testname(h, name, len, TRUE) && (occ <= 0 || ++hcount == occ))
280 /*************************************************
281 * Check the name of a header *
282 *************************************************/
284 /* This function scans a table of header field names that Exim recognizes, and
285 returns the identification of a match. If "resent" is true, the header is known
286 to start with "resent-". In that case, the function matches only those fields
287 that are allowed to appear with resent- in front of them.
290 h points to the header line
291 is_resent TRUE if the name starts "Resent-"
293 Returns: One of the htype_ enum values, identifying the header
297 header_checkname(header_line *h, BOOL is_resent)
299 uschar *text = h->text;
300 header_name *bot = header_names;
301 header_name *top = header_names + header_names_size;
303 if (is_resent) text += 7;
307 header_name *mid = bot + (top - bot)/2;
308 int c = strncmpic(text, mid->name, mid->len);
312 uschar *s = text + mid->len;
313 while (isspace(*s)) s++;
315 return (!is_resent || mid->allow_resent)? mid->htype : htype_other;
319 if (c > 0) bot = mid + 1; else top = mid;
326 /*************************************************
327 * Scan a header for certain strings *
328 *************************************************/
330 /* This function is used for the "personal" test. It scans a particular header
331 line for any one of a number of strings, matched caselessly either as plain
332 strings, or as regular expressions. If the header line contains a list of
333 addresses, each match is applied only to the operative part of each address in
334 the header, and non-regular expressions must be exact matches.
336 The patterns can be provided either as a chain of string_item structures, or
337 inline in the argument list, or both. If there is more than one header of the
338 same name, they are all searched.
341 name header name, including the trailing colon
342 has_addresses TRUE if the header contains a list of addresses
343 cond value to return if the header contains any of the strings
344 strings points to a chain of string_item blocks
345 count number of inline strings
346 ... the inline strings
348 Returns: cond if the header exists and contains one of the strings;
353 /* First we have a local subroutine to handle a single pattern */
356 one_pattern_match(uschar *name, int slen, BOOL has_addresses, uschar *pattern)
360 const pcre *re = NULL;
362 /* If the pattern is a regex, compile it. Bomb out if compiling fails; these
363 patterns are all constructed internally and should be valid. */
365 if (*pattern == '^') re = regex_must_compile(pattern, TRUE, FALSE);
367 /* Scan for the required header(s) and scan each one */
369 for (h = header_list; !yield && h != NULL; h = h->next)
371 if (h->type == htype_old || slen > h->slen ||
372 strncmpic(name, h->text, slen) != 0)
375 /* If the header is a list of addresses, extract each one in turn, and scan
376 it. A non-regex scan must be an exact match for the address. */
380 uschar *s = h->text + slen;
382 while (!yield && *s != 0)
384 uschar *error, *next;
385 uschar *e = parse_find_address_end(s, FALSE);
387 int start, end, domain;
389 /* Temporarily terminate the string at the address end while extracting
390 the operative address within. */
393 next = parse_extract_address(s, &error, &start, &end, &domain, FALSE);
396 /* Move on, ready for the next address */
401 /* If there is some kind of syntax error, just give up on this header
404 if (next == NULL) break;
406 /* Otherwise, test for the pattern; a non-regex must be an exact match */
408 yield = (re == NULL)?
409 (strcmpic(next, pattern) == 0)
411 (pcre_exec(re, NULL, CS next, Ustrlen(next), 0, PCRE_EOPT, NULL, 0)
416 /* For headers that are not lists of addresses, scan the entire header line,
417 and just require "contains" for non-regex patterns. */
421 yield = (re == NULL)?
422 (strstric(h->text, pattern, FALSE) != NULL)
424 (pcre_exec(re, NULL, CS h->text, h->slen, 0, PCRE_EOPT, NULL, 0) >= 0);
432 /* The externally visible interface */
435 header_match(uschar *name, BOOL has_addresses, BOOL cond, string_item *strings,
441 int slen = Ustrlen(name);
443 for (s = strings; s != NULL; s = s->next)
445 if (one_pattern_match(name, slen, has_addresses, s->text)) return cond;
449 for (i = 0; i < count; i++)
450 if (one_pattern_match(name, slen, has_addresses, va_arg(ap, uschar *)))
460 /* End of header.c */