1b6bf56d1d2eba734c1f217b456a8205090f5bc3
1 /* $Cambridge: exim/src/src/header.c,v 1.8 2009/11/16 19:50:37 nm4 Exp $ */
3 /*************************************************
4 * Exim - an Internet mail transport agent *
5 *************************************************/
7 /* Copyright (c) University of Cambridge 1995 - 2009 */
8 /* See the file NOTICE for conditions of use and distribution. */
14 /*************************************************
15 * Test a header for matching name *
16 *************************************************/
18 /* This function tests the name of a header. It is made into a function because
19 it isn't just a string comparison: spaces and tabs are permitted between the
20 name and the colon. The h->text field should nowadays never be NULL, but check
24 h points to the header
26 len the length of the name
27 notdel if TRUE, force FALSE for deleted headers
29 Returns: TRUE or FALSE
33 header_testname(header_line
*h
, uschar
*name
, int len
, BOOL notdel
)
36 if (h
->type
== '*' && notdel
) return FALSE
;
37 if (h
->text
== NULL
|| strncmpic(h
->text
, name
, len
) != 0) return FALSE
;
39 while (*tt
== ' ' || *tt
== '\t') tt
++;
43 /* This is a copy of the function above, only that it is possible to pass
44 only the beginning of a header name. It simply does a front-anchored
45 substring match. Arguments and Return codes are the same as for
46 header_testname() above. */
49 header_testname_incomplete(header_line
*h
, uschar
*name
, int len
, BOOL notdel
)
51 if (h
->type
== '*' && notdel
) return FALSE
;
52 if (h
->text
== NULL
|| strncmpic(h
->text
, name
, len
) != 0) return FALSE
;
57 /*************************************************
58 * Add new header backend function *
59 *************************************************/
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.
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.
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"
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
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)
88 ap va_list value for format arguments
94 header_add_backend(BOOL after
, uschar
*name
, BOOL topnot
, int type
,
95 char *format
, va_list ap
)
101 uschar buffer
[HEADER_ADD_BUFFER_SIZE
];
103 if (header_last
== NULL
) return;
105 if (!string_vformat(buffer
, sizeof(buffer
), format
, ap
))
106 log_write(0, LOG_MAIN
|LOG_PANIC_DIE
, "string too long in header_add: "
107 "%.100s ...", buffer
);
109 /* Find where to insert this header */
115 hptr
= &(header_last
->next
);
122 /* header_list->text can be NULL if we get here between when the new
123 received header is allocated and when it is acutally filled in. We want
124 that header to be first, so skip it for now. */
126 if (header_list
->text
== NULL
)
127 hptr
= &header_list
->next
;
134 int len
= Ustrlen(name
);
136 /* Find the first non-deleted header witht the correct name. */
138 for (hptr
= &header_list
; (h
= *hptr
) != NULL
; hptr
= &(h
->next
))
140 if (header_testname(h
, name
, len
, TRUE
)) break;
143 /* Handle the case where no header is found. To insert at the bottom, nothing
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. */
162 if (h
->next
== NULL
|| !header_testname(h
, name
, len
, FALSE
)) break;
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. */
173 for (p
= q
= buffer
; *p
!= 0; )
177 q
= Ustrchr(q
, '\n');
178 if (q
== NULL
) q
= p
+ Ustrlen(p
);
179 if (*(++q
) != ' ' && *q
!= '\t') break;
182 new = store_get(sizeof(header_line
));
183 new->text
= string_copyn(p
, q
- p
);
191 if (h
== NULL
) header_last
= new;
197 /*************************************************
198 * Add new header anywhere in the chain *
199 *************************************************/
201 /* This is an external interface to header_add_backend().
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
215 header_add_at_position(BOOL after
, uschar
*name
, BOOL topnot
, int type
,
219 va_start(ap
, format
);
220 header_add_backend(after
, name
, topnot
, type
, format
, ap
);
226 /*************************************************
227 * Add new header on end of chain *
228 *************************************************/
230 /* This is now a convenience interface to header_add_backend().
233 type Exim header type character
234 format sprintf format
235 ... arguments for the format
241 header_add(int type
, char *format
, ...)
244 va_start(ap
, format
);
245 header_add_backend(TRUE
, NULL
, FALSE
, type
, format
, ap
);
251 /*************************************************
252 * Remove (mark as old) a header *
253 *************************************************/
255 /* This function is used by the filter code; it is also exported in the
256 local_scan() API. If no header is found, the function does nothing.
259 occ the occurrence number for multiply-defined headers
260 <= 0 means "all"; deleted headers are not counted
267 header_remove(int occ
, uschar
*name
)
271 int len
= Ustrlen(name
);
272 for (h
= header_list
; h
!= NULL
; h
= h
->next
)
274 if (header_testname(h
, name
, len
, TRUE
) && (occ
<= 0 || ++hcount
== occ
))
284 /*************************************************
285 * Check the name of a header *
286 *************************************************/
288 /* This function scans a table of header field names that Exim recognizes, and
289 returns the identification of a match. If "resent" is true, the header is known
290 to start with "resent-". In that case, the function matches only those fields
291 that are allowed to appear with resent- in front of them.
294 h points to the header line
295 is_resent TRUE if the name starts "Resent-"
297 Returns: One of the htype_ enum values, identifying the header
301 header_checkname(header_line
*h
, BOOL is_resent
)
303 uschar
*text
= h
->text
;
304 header_name
*bot
= header_names
;
305 header_name
*top
= header_names
+ header_names_size
;
307 if (is_resent
) text
+= 7;
311 header_name
*mid
= bot
+ (top
- bot
)/2;
312 int c
= strncmpic(text
, mid
->name
, mid
->len
);
316 uschar
*s
= text
+ mid
->len
;
317 while (isspace(*s
)) s
++;
319 return (!is_resent
|| mid
->allow_resent
)? mid
->htype
: htype_other
;
323 if (c
> 0) bot
= mid
+ 1; else top
= mid
;
330 /*************************************************
331 * Scan a header for certain strings *
332 *************************************************/
334 /* This function is used for the "personal" test. It scans a particular header
335 line for any one of a number of strings, matched caselessly either as plain
336 strings, or as regular expressions. If the header line contains a list of
337 addresses, each match is applied only to the operative part of each address in
338 the header, and non-regular expressions must be exact matches.
340 The patterns can be provided either as a chain of string_item structures, or
341 inline in the argument list, or both. If there is more than one header of the
342 same name, they are all searched.
345 name header name, including the trailing colon
346 has_addresses TRUE if the header contains a list of addresses
347 cond value to return if the header contains any of the strings
348 strings points to a chain of string_item blocks
349 count number of inline strings
350 ... the inline strings
352 Returns: cond if the header exists and contains one of the strings;
357 /* First we have a local subroutine to handle a single pattern */
360 one_pattern_match(uschar
*name
, int slen
, BOOL has_addresses
, uschar
*pattern
)
364 const pcre
*re
= NULL
;
366 /* If the pattern is a regex, compile it. Bomb out if compiling fails; these
367 patterns are all constructed internally and should be valid. */
369 if (*pattern
== '^') re
= regex_must_compile(pattern
, TRUE
, FALSE
);
371 /* Scan for the required header(s) and scan each one */
373 for (h
= header_list
; !yield
&& h
!= NULL
; h
= h
->next
)
375 if (h
->type
== htype_old
|| slen
> h
->slen
||
376 strncmpic(name
, h
->text
, slen
) != 0)
379 /* If the header is a list of addresses, extract each one in turn, and scan
380 it. A non-regex scan must be an exact match for the address. */
384 uschar
*s
= h
->text
+ slen
;
386 while (!yield
&& *s
!= 0)
388 uschar
*error
, *next
;
389 uschar
*e
= parse_find_address_end(s
, FALSE
);
391 int start
, end
, domain
;
393 /* Temporarily terminate the string at the address end while extracting
394 the operative address within. */
397 next
= parse_extract_address(s
, &error
, &start
, &end
, &domain
, FALSE
);
400 /* Move on, ready for the next address */
405 /* If there is some kind of syntax error, just give up on this header
408 if (next
== NULL
) break;
410 /* Otherwise, test for the pattern; a non-regex must be an exact match */
412 yield
= (re
== NULL
)?
413 (strcmpic(next
, pattern
) == 0)
415 (pcre_exec(re
, NULL
, CS next
, Ustrlen(next
), 0, PCRE_EOPT
, NULL
, 0)
420 /* For headers that are not lists of addresses, scan the entire header line,
421 and just require "contains" for non-regex patterns. */
425 yield
= (re
== NULL
)?
426 (strstric(h
->text
, pattern
, FALSE
) != NULL
)
428 (pcre_exec(re
, NULL
, CS h
->text
, h
->slen
, 0, PCRE_EOPT
, NULL
, 0) >= 0);
436 /* The externally visible interface */
439 header_match(uschar
*name
, BOOL has_addresses
, BOOL cond
, string_item
*strings
,
445 int slen
= Ustrlen(name
);
447 for (s
= strings
; s
!= NULL
; s
= s
->next
)
449 if (one_pattern_match(name
, slen
, has_addresses
, s
->text
)) return cond
;
453 for (i
= 0; i
< count
; i
++)
455 if (one_pattern_match(name
, slen
, has_addresses
, va_arg(ap
, uschar
*)))
463 /* End of header.c */