Contents of /tags/mkinitrd-6_1_0/busybox/mailutils/sendmail.c
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Fri Apr 24 19:09:57 2009 UTC (15 years, 5 months ago) by niro
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Fri Apr 24 19:09:57 2009 UTC (15 years, 5 months ago) by niro
File MIME type: text/plain
File size: 11012 byte(s)
tagged 'mkinitrd-6_1_0'
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * bare bones sendmail |
4 | * |
5 | * Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com> |
6 | * |
7 | * Licensed under GPLv2, see file LICENSE in this tarball for details. |
8 | */ |
9 | #include "libbb.h" |
10 | #include "mail.h" |
11 | |
12 | static int smtp_checkp(const char *fmt, const char *param, int code) |
13 | { |
14 | char *answer; |
15 | const char *msg = command(fmt, param); |
16 | // read stdin |
17 | // if the string has a form \d\d\d- -- read next string. E.g. EHLO response |
18 | // parse first bytes to a number |
19 | // if code = -1 then just return this number |
20 | // if code != -1 then checks whether the number equals the code |
21 | // if not equal -> die saying msg |
22 | while ((answer = xmalloc_fgetline(stdin)) != NULL) |
23 | if (strlen(answer) <= 3 || '-' != answer[3]) |
24 | break; |
25 | if (answer) { |
26 | int n = atoi(answer); |
27 | if (timeout) |
28 | alarm(0); |
29 | free(answer); |
30 | if (-1 == code || n == code) |
31 | return n; |
32 | } |
33 | bb_error_msg_and_die("%s failed", msg); |
34 | } |
35 | |
36 | static int smtp_check(const char *fmt, int code) |
37 | { |
38 | return smtp_checkp(fmt, NULL, code); |
39 | } |
40 | |
41 | // strip argument of bad chars |
42 | static char *sane_address(char *str) |
43 | { |
44 | char *s = str; |
45 | char *p = s; |
46 | while (*s) { |
47 | if (isalnum(*s) || '_' == *s || '-' == *s || '.' == *s || '@' == *s) { |
48 | *p++ = *s; |
49 | } |
50 | s++; |
51 | } |
52 | *p = '\0'; |
53 | return str; |
54 | } |
55 | |
56 | static void rcptto(const char *s) |
57 | { |
58 | smtp_checkp("RCPT TO:<%s>", s, 250); |
59 | } |
60 | |
61 | int sendmail_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
62 | int sendmail_main(int argc UNUSED_PARAM, char **argv) |
63 | { |
64 | #if ENABLE_FEATURE_SENDMAIL_MAILX |
65 | llist_t *opt_attachments = NULL; |
66 | const char *opt_subject; |
67 | #if ENABLE_FEATURE_SENDMAIL_MAILXX |
68 | llist_t *opt_carboncopies = NULL; |
69 | char *opt_errors_to; |
70 | #endif |
71 | #endif |
72 | char *opt_connect = opt_connect; |
73 | char *opt_from, *opt_fullname; |
74 | char *boundary; |
75 | llist_t *l; |
76 | llist_t *headers = NULL; |
77 | char *domain = sane_address(safe_getdomainname()); |
78 | int code; |
79 | |
80 | enum { |
81 | OPT_w = 1 << 0, // network timeout |
82 | OPT_t = 1 << 1, // read message for recipients |
83 | OPT_N = 1 << 2, // request notification |
84 | OPT_f = 1 << 3, // sender address |
85 | OPT_F = 1 << 4, // sender name, overrides $NAME |
86 | OPT_s = 1 << 5, // subject |
87 | OPT_j = 1 << 6, // assumed charset |
88 | OPT_a = 1 << 7, // attachment(s) |
89 | OPT_H = 1 << 8, // use external connection helper |
90 | OPT_S = 1 << 9, // specify connection string |
91 | OPT_c = 1 << 10, // carbon copy |
92 | OPT_e = 1 << 11, // errors-to address |
93 | }; |
94 | |
95 | // init global variables |
96 | INIT_G(); |
97 | |
98 | // save initial stdin since body is piped! |
99 | xdup2(STDIN_FILENO, 3); |
100 | G.fp0 = fdopen(3, "r"); |
101 | |
102 | // parse options |
103 | opt_complementary = "w+" USE_FEATURE_SENDMAIL_MAILX(":a::H--S:S--H") USE_FEATURE_SENDMAIL_MAILXX(":c::"); |
104 | opts = getopt32(argv, |
105 | "w:t" "N:f:F:" USE_FEATURE_SENDMAIL_MAILX("s:j:a:H:S:") USE_FEATURE_SENDMAIL_MAILXX("c:e:") |
106 | "X:V:vq:R:O:o:nmL:Iih:GC:B:b:A:" // postfix compat only, ignored |
107 | // r:Q:p:M:Dd are candidates from another man page. TODO? |
108 | "46E", // ssmtp introduces another quirks. TODO?: -a[upm] (user, pass, method) to be supported |
109 | &timeout /* -w */, NULL, &opt_from, &opt_fullname, |
110 | USE_FEATURE_SENDMAIL_MAILX(&opt_subject, &G.opt_charset, &opt_attachments, &opt_connect, &opt_connect,) |
111 | USE_FEATURE_SENDMAIL_MAILXX(&opt_carboncopies, &opt_errors_to,) |
112 | NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL |
113 | ); |
114 | //argc -= optind; |
115 | argv += optind; |
116 | |
117 | // connect to server |
118 | |
119 | #if ENABLE_FEATURE_SENDMAIL_MAILX |
120 | // N.B. -H and -S are mutually exclusive so they do not spoil opt_connect |
121 | // connection helper ordered? -> |
122 | if (opts & OPT_H) { |
123 | const char *args[] = { "sh", "-c", opt_connect, NULL }; |
124 | // plug it in |
125 | launch_helper(args); |
126 | // vanilla connection |
127 | } else |
128 | #endif |
129 | { |
130 | int fd; |
131 | // host[:port] not explicitly specified ? -> use $SMTPHOST |
132 | // no $SMTPHOST ? -> use localhost |
133 | if (!(opts & OPT_S)) { |
134 | opt_connect = getenv("SMTPHOST"); |
135 | if (!opt_connect) |
136 | opt_connect = (char *)"127.0.0.1"; |
137 | } |
138 | // do connect |
139 | fd = create_and_connect_stream_or_die(opt_connect, 25); |
140 | // and make ourselves a simple IO filter |
141 | xmove_fd(fd, STDIN_FILENO); |
142 | xdup2(STDIN_FILENO, STDOUT_FILENO); |
143 | } |
144 | // N.B. from now we know nothing about network :) |
145 | |
146 | // wait for initial server OK |
147 | // N.B. if we used openssl the initial 220 answer is already swallowed during openssl TLS init procedure |
148 | // so we need to push the server to see whether we are ok |
149 | code = smtp_check("NOOP", -1); |
150 | // 220 on plain connection, 250 on openssl-helped TLS session |
151 | if (220 == code) |
152 | smtp_check(NULL, 250); // reread the code to stay in sync |
153 | else if (250 != code) |
154 | bb_error_msg_and_die("INIT failed"); |
155 | |
156 | // we should start with modern EHLO |
157 | if (250 != smtp_checkp("EHLO %s", domain, -1)) { |
158 | smtp_checkp("HELO %s", domain, 250); |
159 | } |
160 | |
161 | // set sender |
162 | // N.B. we have here a very loosely defined algotythm |
163 | // since sendmail historically offers no means to specify secrets on cmdline. |
164 | // 1) server can require no authentication -> |
165 | // we must just provide a (possibly fake) reply address. |
166 | // 2) server can require AUTH -> |
167 | // we must provide valid username and password along with a (possibly fake) reply address. |
168 | // For the sake of security username and password are to be read either from console or from a secured file. |
169 | // Since reading from console may defeat usability, the solution is either to read from a predefined |
170 | // file descriptor (e.g. 4), or again from a secured file. |
171 | |
172 | // got no sender address? -> use system username as a resort |
173 | if (!(opts & OPT_f)) { |
174 | // N.B. IMHO getenv("USER") can be way easily spoofed! |
175 | G.user = bb_getpwuid(NULL, -1, getuid()); |
176 | opt_from = xasprintf("%s@%s", G.user, domain); |
177 | } |
178 | if (ENABLE_FEATURE_CLEAN_UP) |
179 | free(domain); |
180 | |
181 | code = -1; // first try softly without authentication |
182 | while (250 != smtp_checkp("MAIL FROM:<%s>", opt_from, code)) { |
183 | // MAIL FROM failed -> authentication needed |
184 | if (334 == smtp_check("AUTH LOGIN", -1)) { |
185 | // we must read credentials |
186 | get_cred_or_die(4); |
187 | encode_base64(NULL, G.user, NULL); |
188 | smtp_check("", 334); |
189 | encode_base64(NULL, G.pass, NULL); |
190 | smtp_check("", 235); |
191 | } |
192 | // authenticated OK? -> retry to set sender |
193 | // but this time die on failure! |
194 | code = 250; |
195 | } |
196 | |
197 | // recipients specified as arguments |
198 | while (*argv) { |
199 | char *s = sane_address(*argv); |
200 | // loose test on email address validity |
201 | // if (strchr(s, '@')) { |
202 | rcptto(s); |
203 | llist_add_to_end(&headers, xasprintf("To: %s", s)); |
204 | // } |
205 | argv++; |
206 | } |
207 | |
208 | #if ENABLE_FEATURE_SENDMAIL_MAILXX |
209 | // carbon copies recipients specified as -c options |
210 | for (l = opt_carboncopies; l; l = l->link) { |
211 | char *s = sane_address(l->data); |
212 | // loose test on email address validity |
213 | // if (strchr(s, '@')) { |
214 | rcptto(s); |
215 | // TODO: do we ever need to mangle the message? |
216 | //llist_add_to_end(&headers, xasprintf("Cc: %s", s)); |
217 | // } |
218 | } |
219 | #endif |
220 | |
221 | // if -t specified or no recipients specified -> read recipients from message |
222 | // i.e. scan stdin for To:, Cc:, Bcc: lines ... |
223 | // ... and then use the rest of stdin as message body |
224 | // N.B. subject read from body can be further overrided with one specified on command line. |
225 | // recipients are merged. Bcc: lines are deleted |
226 | // N.B. other headers are collected and will be dumped verbatim |
227 | if (opts & OPT_t || !headers) { |
228 | // fetch recipients and (optionally) subject |
229 | char *s; |
230 | while ((s = xmalloc_fgetline(G.fp0)) != NULL) { |
231 | if (0 == strncasecmp("To: ", s, 4) || 0 == strncasecmp("Cc: ", s, 4)) { |
232 | rcptto(sane_address(s+4)); |
233 | llist_add_to_end(&headers, s); |
234 | } else if (0 == strncasecmp("Bcc: ", s, 5)) { |
235 | rcptto(sane_address(s+5)); |
236 | free(s); |
237 | // N.B. Bcc vanishes from headers! |
238 | } else if (0 == strncmp("Subject: ", s, 9)) { |
239 | // we read subject -> use it verbatim unless it is specified |
240 | // on command line |
241 | if (!(opts & OPT_s)) |
242 | llist_add_to_end(&headers, s); |
243 | else |
244 | free(s); |
245 | } else if (s[0]) { |
246 | // misc header |
247 | llist_add_to_end(&headers, s); |
248 | } else { |
249 | free(s); |
250 | break; // stop on the first empty line |
251 | } |
252 | } |
253 | } |
254 | |
255 | // enter "put message" mode |
256 | smtp_check("DATA", 354); |
257 | |
258 | // put headers we could have preread with -t |
259 | for (l = headers; l; l = l->link) { |
260 | printf("%s\r\n", l->data); |
261 | if (ENABLE_FEATURE_CLEAN_UP) |
262 | free(l->data); |
263 | } |
264 | |
265 | // put (possibly encoded) subject |
266 | #if ENABLE_FEATURE_SENDMAIL_MAILX |
267 | if (opts & OPT_s) { |
268 | printf("Subject: "); |
269 | if (opts & OPT_j) { |
270 | printf("=?%s?B?", G.opt_charset); |
271 | encode_base64(NULL, opt_subject, NULL); |
272 | printf("?="); |
273 | } else { |
274 | printf("%s", opt_subject); |
275 | } |
276 | printf("\r\n"); |
277 | } |
278 | #endif |
279 | |
280 | // put sender name, $NAME is the default |
281 | if (!(opts & OPT_F)) |
282 | opt_fullname = getenv("NAME"); |
283 | if (opt_fullname) |
284 | printf("From: \"%s\" <%s>\r\n", opt_fullname, opt_from); |
285 | |
286 | // put notification |
287 | if (opts & OPT_N) |
288 | printf("Disposition-Notification-To: %s\r\n", opt_from); |
289 | |
290 | #if ENABLE_FEATURE_SENDMAIL_MAILXX |
291 | // put errors recipient |
292 | if (opts & OPT_e) |
293 | printf("Errors-To: %s\r\n", opt_errors_to); |
294 | #endif |
295 | |
296 | // make a random string -- it will delimit message parts |
297 | srand(monotonic_us()); |
298 | boundary = xasprintf("%d=_%d-%d", rand(), rand(), rand()); |
299 | |
300 | // put common headers |
301 | // TODO: do we really need this? |
302 | // printf("Message-ID: <%s>\r\n", boundary); |
303 | |
304 | #if ENABLE_FEATURE_SENDMAIL_MAILX |
305 | // have attachments? -> compose multipart MIME |
306 | if (opt_attachments) { |
307 | const char *fmt; |
308 | const char *p; |
309 | char *q; |
310 | |
311 | printf( |
312 | "Mime-Version: 1.0\r\n" |
313 | "%smultipart/mixed; boundary=\"%s\"\r\n" |
314 | , "Content-Type: " |
315 | , boundary |
316 | ); |
317 | |
318 | // body is pseudo attachment read from stdin in first turn |
319 | llist_add_to(&opt_attachments, (char *)"-"); |
320 | |
321 | // put body + attachment(s) |
322 | // N.B. all these weird things just to be tiny |
323 | // by reusing string patterns! |
324 | fmt = |
325 | "\r\n--%s\r\n" |
326 | "%stext/plain; charset=%s\r\n" |
327 | "%s%s\r\n" |
328 | "%s" |
329 | ; |
330 | p = G.opt_charset; |
331 | q = (char *)""; |
332 | l = opt_attachments; |
333 | while (l) { |
334 | printf( |
335 | fmt |
336 | , boundary |
337 | , "Content-Type: " |
338 | , p |
339 | , "Content-Disposition: inline" |
340 | , q |
341 | , "Content-Transfer-Encoding: base64\r\n" |
342 | ); |
343 | p = ""; |
344 | fmt = |
345 | "\r\n--%s\r\n" |
346 | "%sapplication/octet-stream%s\r\n" |
347 | "%s; filename=\"%s\"\r\n" |
348 | "%s" |
349 | ; |
350 | encode_base64(l->data, (const char *)G.fp0, "\r"); |
351 | l = l->link; |
352 | if (l) |
353 | q = bb_get_last_path_component_strip(l->data); |
354 | } |
355 | |
356 | // put message terminator |
357 | printf("\r\n--%s--\r\n" "\r\n", boundary); |
358 | |
359 | // no attachments? -> just dump message |
360 | } else |
361 | #endif |
362 | { |
363 | char *s; |
364 | // terminate headers |
365 | printf("\r\n"); |
366 | // put plain text respecting leading dots |
367 | while ((s = xmalloc_fgetline(G.fp0)) != NULL) { |
368 | // escape leading dots |
369 | // N.B. this feature is implied even if no -i (-oi) switch given |
370 | // N.B. we need to escape the leading dot regardless of |
371 | // whether it is single or not character on the line |
372 | if ('.' == s[0] /*&& '\0' == s[1] */) |
373 | printf("."); |
374 | // dump read line |
375 | printf("%s\r\n", s); |
376 | } |
377 | } |
378 | |
379 | // leave "put message" mode |
380 | smtp_check(".", 250); |
381 | // ... and say goodbye |
382 | smtp_check("QUIT", 221); |
383 | // cleanup |
384 | if (ENABLE_FEATURE_CLEAN_UP) |
385 | fclose(G.fp0); |
386 | |
387 | return EXIT_SUCCESS; |
388 | } |