summaryrefslogtreecommitdiff
path: root/lisp/mail/rfc822.el
blob: 4a1779d44f7e0ea98344917596400c1b5344a572 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
;;; rfc822.el --- hairy rfc822 parser for mail and news and suchlike

;; Copyright (C) 1986-1987, 1990, 2001-2012 Free Software Foundation, Inc.

;; Author: Richard Mlynarik <mly@eddie.mit.edu>
;; Maintainer: FSF
;; Keywords: mail

;; This file is part of GNU Emacs.

;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.

;;; Commentary:

;; Support functions for parsing RFC-822 headers, used by mail and news
;; modes.

;;; Code:

(defvar rfc822-address-start)

;; uses rfc822-address-start free, throws to address
(defun rfc822-bad-address (reason)
  (save-restriction
    (insert "_^_")
    (narrow-to-region rfc822-address-start
		      (if (re-search-forward "[,;]" nil t)
			  (max (point-min) (1- (point)))
			(point-max)))
    ;; make the error string be suitable for inclusion in (...)
    (let ((losers '("\\" "(" ")" "\n")))
      (while losers
	(goto-char (point-min))
	(while (search-forward (car losers) nil t)
	  (backward-char 1)
	  (insert ?\\)
	  (forward-char 1))
	(setq losers (cdr losers))))
    (goto-char (point-min)) (insert "(Unparsable address -- "
				    reason
				    ": \"")
    (goto-char (point-max)) (insert "\")"))
  (rfc822-nuke-whitespace)
  (throw 'address (buffer-substring rfc822-address-start (point))))

(defun rfc822-nuke-whitespace (&optional leave-space)
  (let (ch)
    (while (cond ((eobp)
		  nil)
		 ((= (setq ch (following-char)) ?\()
		  (forward-char 1)
		  (while (if (eobp)
			     (rfc822-bad-address "Unbalanced comment (...)")
			   (/= (setq ch (following-char)) ?\)))
		    (cond ((looking-at "[^()\\]+")
			   (replace-match ""))
			  ((= ch ?\()
			   (rfc822-nuke-whitespace))
			  ((< (point) (1- (point-max)))
			   (delete-char 2))
			  (t
			   (rfc822-bad-address "orphaned backslash"))))
		  ;; delete remaining "()"
		  (forward-char -1)
		  (delete-char 2)
		  t)
		 ((memq ch '(?\  ?\t ?\n))
		  (delete-region (point)
				 (progn (skip-chars-forward " \t\n") (point)))
		  t)
		 (t
		  nil)))
    (or (not leave-space)
	(eobp)
	(bobp)
	(= (preceding-char) ?\ )
	(insert ?\ ))))

(defun rfc822-looking-at (regex &optional leave-space)
  (if (cond ((stringp regex)
	     (if (looking-at regex)
		 (progn (goto-char (match-end 0))
			t)))
	    (t
	     (if (and (not (eobp))
		      (= (following-char) regex))
		 (progn (forward-char 1)
			t))))
      (let ((tem (match-data)))
	(rfc822-nuke-whitespace leave-space)
	(set-match-data tem)
	t)))

(defun rfc822-snarf-word ()
  ;; word is atom | quoted-string
  (cond ((= (following-char) ?\")
	 ;; quoted-string
	 (or (rfc822-looking-at "\"\\([^\"\\\n]\\|\\\\.\\|\\\\\n\\)*\"")
	     (rfc822-bad-address "Unterminated quoted string")))
	((rfc822-looking-at "[^][\000-\037 ()<>@,;:\\\".]+")
	 ;; atom
	 )
	(t
	 (rfc822-bad-address "Rubbish in address"))))

(defun rfc822-snarf-words ()
  (rfc822-snarf-word)
  (while (rfc822-looking-at ?.)
    (rfc822-snarf-word)))

(defun rfc822-snarf-subdomain ()
  ;; sub-domain is domain-ref | domain-literal
  (cond ((= (following-char) ?\[)
	 ;; domain-ref
	 (or (rfc822-looking-at "\\[\\([^][\\\n]\\|\\\\.\\|\\\\\n\\)*\\]")
	     (rfc822-bad-address "Unterminated domain literal [...]")))
	((rfc822-looking-at "[^][\000-\037 ()<>@,;:\\\".]+")
	 ;; domain-literal = atom
	 )
	(t
	 (rfc822-bad-address "Rubbish in host/domain specification"))))

(defun rfc822-snarf-domain ()
  (rfc822-snarf-subdomain)
  (while (rfc822-looking-at ?.)
    (rfc822-snarf-subdomain)))

(defun rfc822-snarf-frob-list (name separator terminator snarfer
				    &optional return)
  (let ((first t)
	(list ())
	tem)
    (while (cond ((eobp)
		  (rfc822-bad-address
		    (format "End of addresses in middle of %s" name)))
		 ((rfc822-looking-at terminator)
		  nil)
		 ((rfc822-looking-at separator)
		  ;; multiple separators are allowed and do nothing.
		  (while (rfc822-looking-at separator))
		  t)
		 (first
		  t)
		 (t
		  (rfc822-bad-address
		    (format "Gubbish in middle of %s" name))))
      (setq tem (funcall snarfer)
	    first nil)
      (and return tem
	   (setq list (if (listp tem)
			  (nconc (reverse tem) list)
			  (cons tem list)))))
    (nreverse list)))

;; return either an address (a string) or a list of addresses
(defun rfc822-addresses-1 (&optional allow-groups)
  ;; Looking for an rfc822 `address'
  ;; Either a group (1*word ":" [#mailbox] ";")
  ;; or a mailbox (addr-spec | 1*word route-addr)
  ;;  addr-spec is (local-part "@" domain)
  ;;  route-addr is ("<" [1#("@" domain) ":"] addr-spec ">")
  ;;  local-part is (word *("." word))
  ;;  word is (atom | quoted-string)
  ;;  quoted-string is ("\([^\"\\n]\|\\.\|\\\n\)")
  ;;  atom is [^\000-\037\177 ()<>@,;:\".[]]+
  ;;  domain is sub-domain *("." sub-domain)
  ;;  sub-domain is domain-ref | domain-literal
  ;;  domain-literal is  "[" *(dtext | quoted-pair) "]"
  ;;  dtext is "[^][\\n"
  ;;  domain-ref is atom
  (let ((rfc822-address-start (point))
	(n 0))
    (catch 'address
      ;; optimize common cases:
      ;;  foo
      ;;  foo.bar@bar.zap
      ;; followed by "\\'\\|,\\|([^()\\]*)\\'"
      ;; other common cases are:
      ;;  foo bar <foo.bar@baz.zap>
      ;;  "foo bar" <foo.bar@baz.zap>
      ;;  those aren't hacked yet.
      (if (and (rfc822-looking-at "[^][\000-\037 ()<>@,;:\\\"]+\\(\\|@[^][\000-\037 ()<>@,;:\\\"]+\\)" t)
	       (progn (or (eobp)
			  (rfc822-looking-at ?,))))
	  (progn
	    ;; rfc822-looking-at may have inserted a space
	    (or (bobp) (/= (preceding-char) ?\ ) (delete-char -1))
	    ;; relying on the fact that rfc822-looking-at <char>
	    ;;  doesn't mung match-data
	    (throw 'address (buffer-substring rfc822-address-start (match-end 0)))))
      (goto-char rfc822-address-start)
      (while t
	(cond ((and (= n 1) (rfc822-looking-at ?@))
	       ;; local-part@domain
	       (rfc822-snarf-domain)
	       (throw 'address
		 (buffer-substring rfc822-address-start (point))))
	      ((rfc822-looking-at ?:)
	       (cond ((not allow-groups)
		      (rfc822-bad-address "A group name may not appear here"))
		     ((= n 0)
		      (rfc822-bad-address "No name for :...; group")))
	       ;; group
	       (throw 'address
		 ;; return a list of addresses
		 (rfc822-snarf-frob-list ":...; group" ?\, ?\;
					 'rfc822-addresses-1 t)))
	      ((rfc822-looking-at ?<)
	       (let ((start (point))
		     (strip t))
		 (cond ((rfc822-looking-at ?>)
			;; empty path
			())
		       ((and (not (eobp)) (= (following-char) ?\@))
			;; <@foo.bar,@baz:quux@abcd.efg>
			(rfc822-snarf-frob-list "<...> address" ?\, ?\:
			  (function (lambda ()
				      (if (rfc822-looking-at ?\@)
					  (rfc822-snarf-domain)
					(rfc822-bad-address
					  "Gubbish in route-addr")))))
			(rfc822-snarf-words)
			(or (rfc822-looking-at ?@)
			    (rfc822-bad-address "Malformed <..@..> address"))
			(rfc822-snarf-domain)
			(setq strip nil))
		       ((progn (rfc822-snarf-words) (rfc822-looking-at ?@))
			; allow <foo> (losing unix seems to do this)
			(rfc822-snarf-domain)))
		 (let ((end (point)))
		   (if (rfc822-looking-at ?\>)
		       (throw 'address
			 (buffer-substring (if strip start (1- start))
					   (if strip end (1+ end))))
		     (rfc822-bad-address "Unterminated <...> address")))))
	      ((looking-at "[^][\000-\037 ()<>@,;:\\.]")
	       ;; this allows "." to be part of the words preceding
	       ;; an addr-spec, since many broken mailers output
	       ;; "Hern K. Herklemeyer III
	       ;;   <yank@megadeath.dod.gods-own-country>"
               (let ((again t))
                 (while again
                   (or (= n 0) (bobp) (= (preceding-char) ?\ )
                       (insert ?\ ))
                   (rfc822-snarf-words)
                   (setq n (1+ n))
                   (setq again (or (rfc822-looking-at ?.)
                                   (looking-at "[^][\000-\037 ()<>@,;:\\.]"))))))
	      ((= n 0)
	       (throw 'address nil))
	      ((= n 1) ; allow "foo" (losing unix seems to do this)
	       (throw 'address
		 (buffer-substring rfc822-address-start (point))))
              ((> n 1)
               (rfc822-bad-address "Missing comma between addresses or badly-formatted address"))
	      ((or (eobp) (= (following-char) ?,))
	       (rfc822-bad-address "Missing comma or route-spec"))
	      (t
	       (rfc822-bad-address "Strange character or missing comma")))))))


(defun rfc822-addresses (header-text)
  (if (string-match "\\`[ \t]*\\([^][\000-\037 ()<>@,;:\\\".]+\\)[ \t]*\\'"
                    header-text)
      ;; Make very simple case moderately fast.
      (list (substring header-text (match-beginning 1) (match-end 1)))
    (let ((buf (generate-new-buffer " rfc822")))
      (unwind-protect
          (with-current-buffer buf
            (make-local-variable 'case-fold-search)
            (setq case-fold-search nil)	;For speed(?)
            (insert header-text)
            ;; unfold continuation lines
            (goto-char (point-min))

            (while (re-search-forward "\\([^\\]\\(\\\\\\\\\\)*\\)\n[ \t]"
                                      nil t)
              (replace-match "\\1 " t))

            (goto-char (point-min))
	    ;; Give `rfc822-address-start' a non-nil initial value to
	    ;; prevent `rfc822-bad-address' from raising a
	    ;; `wrong-type-argument' error.
            (let* ((rfc822-address-start (point))
		   list tem
		   (err
		    (catch 'address
		      ;; Note that `rfc822-nuke-whitespace' and
		      ;; `rfc822-looking-at' can throw.
		      (rfc822-nuke-whitespace)
		      (while (not (eobp))
			(setq rfc822-address-start (point))
			(setq tem
			      (cond ((rfc822-looking-at ?\,)
				     nil)
				    ((looking-at "[][\000-\037@;:\\.>)]")
				     (forward-char)
				     (catch 'address ; For rfc822-bad-address
				       (rfc822-bad-address
					(format "Strange character \\%c found"
						(preceding-char)))))
				    (t
				     (rfc822-addresses-1 t))))
			(cond ((null tem))
			      ((stringp tem)
			       (setq list (cons tem list)))
			      (t
			       (setq list (nconc (nreverse tem) list)))))
		      nil)))
	      (nreverse (append (if err (list err)) list))))
	(and buf (kill-buffer buf))))))

(provide 'rfc822)

;;; rfc822.el ends here