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-rw-r--r--networking/sendmail.c563
1 files changed, 0 insertions, 563 deletions
diff --git a/networking/sendmail.c b/networking/sendmail.c
deleted file mode 100644
index 9602b89ec..000000000
--- a/networking/sendmail.c
+++ /dev/null
@@ -1,563 +0,0 @@
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
11struct globals {
12 pid_t helper_pid;
13 unsigned timeout;
14 FILE *fp0; // initial stdin
15 // arguments for SSL connection helper
16 const char *xargs[9];
17};
18#define G (*ptr_to_globals)
19#define helper_pid (G.helper_pid)
20#define timeout (G.timeout )
21#define fp0 (G.fp0 )
22#define xargs (G.xargs )
23#define INIT_G() do { \
24 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
25 xargs[0] = "openssl"; \
26 xargs[1] = "s_client"; \
27 xargs[2] = "-quiet"; \
28 xargs[3] = "-connect"; \
29 /*xargs[4] = "localhost";*/ \
30 xargs[5] = "-tls1"; \
31 xargs[6] = "-starttls"; \
32 xargs[7] = "smtp"; \
33} while (0)
34
35#define opt_connect (xargs[4])
36
37static void uuencode(char *fname, const char *text)
38{
39 enum {
40 SRC_BUF_SIZE = 45, /* This *MUST* be a multiple of 3 */
41 DST_BUF_SIZE = 4 * ((SRC_BUF_SIZE + 2) / 3),
42 };
43
44#define src_buf text
45 FILE *fp = fp;
46 ssize_t len = len;
47 char dst_buf[DST_BUF_SIZE + 1];
48
49 if (fname) {
50 fp = (NOT_LONE_DASH(fname)) ? xfopen_for_read(fname) : fp0;
51 src_buf = bb_common_bufsiz1;
52 // N.B. strlen(NULL) segfaults!
53 } else if (text) {
54 // though we do not call uuencode(NULL, NULL) explicitly
55 // still we do not want to break things suddenly
56 len = strlen(text);
57 } else
58 return;
59
60 while (1) {
61 size_t size;
62 if (fname) {
63 size = fread((char *)src_buf, 1, SRC_BUF_SIZE, fp);
64 if ((ssize_t)size < 0)
65 bb_perror_msg_and_die(bb_msg_read_error);
66 } else {
67 size = len;
68 if (len > SRC_BUF_SIZE)
69 size = SRC_BUF_SIZE;
70 }
71 if (!size)
72 break;
73 // encode the buffer we just read in
74 bb_uuencode(dst_buf, src_buf, size, bb_uuenc_tbl_base64);
75 if (fname) {
76 printf("\r\n");
77 } else {
78 src_buf += size;
79 len -= size;
80 }
81 fwrite(dst_buf, 1, 4 * ((size + 2) / 3), stdout);
82 }
83 if (fname)
84 fclose(fp);
85#undef src_buf
86}
87
88
89#if ENABLE_FEATURE_SENDMAIL_SSL
90static void kill_helper(void)
91{
92 // TODO!!!: is there more elegant way to terminate child on program failure?
93 if (helper_pid > 0)
94 kill(helper_pid, SIGTERM);
95}
96
97// generic signal handler
98static void signal_handler(int signo)
99{
100#define err signo
101 if (SIGALRM == signo) {
102 kill_helper();
103 bb_error_msg_and_die("timed out");
104 }
105
106 // SIGCHLD. reap zombies
107 if (wait_any_nohang(&err) > 0)
108 if (WIFEXITED(err)) {
109// if (WEXITSTATUS(err))
110 bb_error_msg_and_die("child exited (%d)", WEXITSTATUS(err));
111// else
112// kill(0, SIGCONT);
113 }
114#undef err
115}
116
117static void launch_helper(const char **argv)
118{
119 // setup vanilla unidirectional pipes interchange
120 int idx;
121 int pipes[4];
122
123 xpipe(pipes);
124 xpipe(pipes+2);
125 helper_pid = vfork();
126 if (helper_pid < 0)
127 bb_perror_msg_and_die("vfork");
128 idx = (!helper_pid) * 2;
129 xdup2(pipes[idx], STDIN_FILENO);
130 xdup2(pipes[3-idx], STDOUT_FILENO);
131 if (ENABLE_FEATURE_CLEAN_UP)
132 for (int i = 4; --i >= 0; )
133 if (pipes[i] > STDOUT_FILENO)
134 close(pipes[i]);
135 if (!helper_pid) {
136 // child: try to execute connection helper
137 BB_EXECVP(*argv, (char **)argv);
138 _exit(127);
139 }
140 // parent: check whether child is alive
141 bb_signals(0
142 + (1 << SIGCHLD)
143 + (1 << SIGALRM)
144 , signal_handler);
145 signal_handler(SIGCHLD);
146 // child seems OK -> parent goes on
147}
148#else
149#define kill_helper() ((void)0)
150#define launch_helper(x) bb_error_msg_and_die("no SSL support")
151#endif
152
153static const char *command(const char *fmt, const char *param)
154{
155 const char *msg = fmt;
156 alarm(timeout);
157 if (msg) {
158 msg = xasprintf(fmt, param);
159 printf("%s\r\n", msg);
160 }
161 fflush(stdout);
162 return msg;
163}
164
165static int smtp_checkp(const char *fmt, const char *param, int code)
166{
167 char *answer;
168 const char *msg = command(fmt, param);
169 // read stdin
170 // if the string has a form \d\d\d- -- read next string. E.g. EHLO response
171 // parse first bytes to a number
172 // if code = -1 then just return this number
173 // if code != -1 then checks whether the number equals the code
174 // if not equal -> die saying msg
175 while ((answer = xmalloc_fgetline(stdin)) != NULL)
176 if (strlen(answer) <= 3 || '-' != answer[3])
177 break;
178 if (answer) {
179 int n = atoi(answer);
180 alarm(0);
181 free(answer);
182 if (-1 == code || n == code)
183 return n;
184 }
185 kill_helper();
186 bb_error_msg_and_die("%s failed", msg);
187}
188
189static inline int smtp_check(const char *fmt, int code)
190{
191 return smtp_checkp(fmt, NULL, code);
192}
193
194// strip argument of bad chars
195static char *sane(char *str)
196{
197 char *s = str;
198 char *p = s;
199 while (*s) {
200 if (isalnum(*s) || '_' == *s || '-' == *s || '.' == *s || '@' == *s) {
201 *p++ = *s;
202 }
203 s++;
204 }
205 *p = '\0';
206 return str;
207}
208
209// NB: parse_url can modify url[] (despite const), but only if '@' is there
210static const char *parse_url(const char *url, const char **user, const char **pass)
211{
212 // parse [user[:pass]@]host
213 // return host
214 char *s = strchr(url, '@');
215 *user = *pass = NULL;
216 if (s) {
217 *s++ = '\0';
218 *user = url;
219 url = s;
220 s = strchr(*user, ':');
221 if (s) {
222 *s++ = '\0';
223 *pass = s;
224 }
225 }
226 return url;
227}
228
229static void rcptto(const char *s)
230{
231 smtp_checkp("RCPT TO:<%s>", s, 250);
232}
233
234int sendmail_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
235int sendmail_main(int argc UNUSED_PARAM, char **argv)
236{
237#if ENABLE_FEATURE_SENDMAIL_MAILX
238 llist_t *opt_attachments = NULL;
239 const char *opt_subject;
240 const char *opt_charset = CONFIG_FEATURE_SENDMAIL_CHARSET;
241#if ENABLE_FEATURE_SENDMAIL_MAILXX
242 llist_t *opt_carboncopies = NULL;
243 char *opt_errors_to;
244#endif
245#endif
246 char *opt_from, *opt_fullname;
247 const char *opt_user;
248 const char *opt_pass;
249 int code;
250 char *boundary;
251 llist_t *l;
252 llist_t *headers = NULL;
253 char *domain = sane(safe_getdomainname());
254 unsigned opts;
255
256 enum {
257 OPT_w = 1 << 0, // network timeout
258 OPT_H = 1 << 1, // [user:password@]server[:port]
259 OPT_S = 1 << 2, // connect using openssl s_client helper
260 OPT_t = 1 << 3, // read message for recipients
261 OPT_N = 1 << 4, // request notification
262 OPT_f = 1 << 5, // sender address
263 OPT_F = 1 << 6, // sender name, overrides $NAME
264#if ENABLE_FEATURE_SENDMAIL_MAILX
265 OPT_s = 1 << 7, // subject
266 OPT_j = 1 << 8, // assumed charset
267 OPT_a = 1 << 9, // attachment(s)
268#if ENABLE_FEATURE_SENDMAIL_MAILXX
269 OPT_c = 1 << 10, // carbon copy
270 OPT_e = 1 << 11, // errors-to address
271#endif
272#endif
273 };
274
275 // init global variables
276 INIT_G();
277
278 // save initial stdin since body is piped!
279 xdup2(STDIN_FILENO, 3);
280 fp0 = fdopen(3, "r");
281
282 // parse options
283 opt_complementary = "w+:a::" USE_FEATURE_SENDMAIL_MAILXX("c::");
284 opts = getopt32(argv,
285 "w:H:St" "N:f:F:" USE_FEATURE_SENDMAIL_MAILX("s:j:a:") USE_FEATURE_SENDMAIL_MAILXX("c:e:")
286 "X:V:vq:R:O:o:nmL:Iih:GC:B:b:A:" // postfix compat only, ignored
287 // r:Q:p:M:Dd are candidates from another man page. TODO?
288 "46E", // ssmtp introduces another quirks. TODO?: -a[upm] (user, pass, method) to be supported
289 &timeout /* -w */, &opt_connect /* -H */,
290 NULL, &opt_from, &opt_fullname,
291 USE_FEATURE_SENDMAIL_MAILX(&opt_subject, &opt_charset, &opt_attachments,)
292 USE_FEATURE_SENDMAIL_MAILXX(&opt_carboncopies, &opt_errors_to,)
293 NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL
294 );
295 //argc -= optind;
296 argv += optind;
297
298 // connect to server
299 // host[:port] not specified ? -> use $SMTPHOST. no $SMTPHOST ? -> use localhost
300 if (!(opts & OPT_H)) {
301 opt_connect = getenv("SMTPHOST");
302 if (!opt_connect)
303 opt_connect = "127.0.0.1";
304 }
305 // fetch username and password, if any
306 // NB: parse_url modifies opt_connect[] ONLY if '@' is there.
307 // Thus "127.0.0.1" won't be modified, an is ok that it is RO.
308 opt_connect = parse_url(opt_connect, &opt_user, &opt_pass);
309
310 // username must be defined!
311 if (!opt_user) {
312 // N.B. IMHO getenv("USER") can be way easily spoofed!
313 opt_user = bb_getpwuid(NULL, -1, getuid());
314 }
315
316 // SSL ordered? ->
317 if (opts & OPT_S) {
318 // ... use openssl helper
319 launch_helper(xargs);
320 // no SSL ordered? ->
321 } else {
322 // ... make plain connect
323 int fd = create_and_connect_stream_or_die(opt_connect, 25);
324 // make ourselves a simple IO filter
325 // from now we know nothing about network :)
326 xmove_fd(fd, STDIN_FILENO);
327 xdup2(STDIN_FILENO, STDOUT_FILENO);
328 }
329
330 // got no sender address? -> use username as a resort
331 if (!(opts & OPT_f)) {
332 opt_from = xasprintf("%s@%s", opt_user, domain);
333 }
334
335 // introduce to server
336
337 // we didn't use SSL helper? ->
338 if (!(opts & OPT_S)) {
339 // ... wait for initial server OK
340 smtp_check(NULL, 220);
341 }
342
343 // we should start with modern EHLO
344 if (250 != smtp_checkp("EHLO %s", domain, -1)) {
345 smtp_checkp("HELO %s", domain, 250);
346 }
347 if (ENABLE_FEATURE_CLEAN_UP)
348 free(domain);
349
350 // set sender
351 // NOTE: if password has not been specified
352 // then no authentication is possible
353 code = (opt_pass ? -1 : 250);
354 // first try softly without authentication
355 while (250 != smtp_checkp("MAIL FROM:<%s>", opt_from, code)) {
356 // MAIL FROM failed -> authentication needed
357 if (334 == smtp_check("AUTH LOGIN", -1)) {
358 uuencode(NULL, opt_user); // opt_user != NULL
359 smtp_check("", 334);
360 uuencode(NULL, opt_pass);
361 smtp_check("", 235);
362 }
363 // authenticated OK? -> retry to set sender
364 // but this time die on failure!
365 code = 250;
366 }
367
368 // recipients specified as arguments
369 while (*argv) {
370 char *s = sane(*argv);
371 // loose test on email address validity
372 if (strchr(s, '@')) {
373 rcptto(s);
374 llist_add_to_end(&headers, xasprintf("To: %s", s));
375 }
376 argv++;
377 }
378
379#if ENABLE_FEATURE_SENDMAIL_MAILXX
380 // carbon copies recipients specified as -c options
381 for (l = opt_carboncopies; l; l = l->link) {
382 char *s = sane(l->data);
383 // loose test on email address validity
384 if (strchr(s, '@')) {
385 rcptto(s);
386 // TODO: do we ever need to mangle the message?
387 //llist_add_to_end(&headers, xasprintf("Cc: %s", s));
388 }
389 }
390#endif
391
392 // if -t specified or no recipients specified -> read recipients from message
393 // i.e. scan stdin for To:, Cc:, Bcc: lines ...
394 // ... and then use the rest of stdin as message body
395 // N.B. subject read from body can be further overrided with one specified on command line.
396 // recipients are merged. Bcc: lines are deleted
397 // N.B. other headers are collected and will be dumped verbatim
398 if (opts & OPT_t || !headers) {
399 // fetch recipients and (optionally) subject
400 char *s;
401 while ((s = xmalloc_fgetline(fp0)) != NULL) {
402 if (0 == strncasecmp("To: ", s, 4) || 0 == strncasecmp("Cc: ", s, 4)) {
403 rcptto(sane(s+4));
404 llist_add_to_end(&headers, s);
405 } else if (0 == strncasecmp("Bcc: ", s, 5)) {
406 rcptto(sane(s+5));
407 free(s);
408 // N.B. Bcc vanishes from headers!
409 } else if (0 == strncmp("Subject: ", s, 9)) {
410 // we read subject -> use it verbatim unless it is specified
411 // on command line
412#if ENABLE_FEATURE_SENDMAIL_MAILX
413 if (opts & OPT_s)
414 free(s);
415 else
416#endif
417 llist_add_to_end(&headers, s);
418 } else if (s[0]) {
419 // misc header
420 llist_add_to_end(&headers, s);
421 } else {
422 free(s);
423 break; // stop on the first empty line
424 }
425 }
426 }
427
428 // enter "put message" mode
429 smtp_check("DATA", 354);
430
431 // put headers we could have preread with -t
432 for (l = headers; l; l = l->link) {
433 printf("%s\r\n", l->data);
434 if (ENABLE_FEATURE_CLEAN_UP)
435 free(l->data);
436 }
437
438 // put (possibly encoded) subject
439#if ENABLE_FEATURE_SENDMAIL_MAILX
440 if (opts & OPT_j)
441 sane((char *)opt_charset);
442 if (opts & OPT_s) {
443 printf("Subject: ");
444 if (opts & OPT_j) {
445 printf("=?%s?B?", opt_charset);
446 uuencode(NULL, opt_subject);
447 printf("?=");
448 } else {
449 printf("%s", opt_subject);
450 }
451 printf("\r\n");
452 }
453#endif
454
455 // put sender name, $NAME is the default
456 if (!(opts & OPT_F))
457 opt_fullname = getenv("NAME");
458 if (opt_fullname)
459 printf("From: \"%s\" <%s>\r\n", opt_fullname, opt_from);
460
461 // put notification
462 if (opts & OPT_N)
463 printf("Disposition-Notification-To: %s\r\n", opt_from);
464
465#if ENABLE_FEATURE_SENDMAIL_MAILXX
466 // put errors recipient
467 if (opts & OPT_e)
468 printf("Errors-To: %s\r\n", opt_errors_to);
469#endif
470
471 // make a random string -- it will delimit message parts
472 srand(monotonic_us());
473 boundary = xasprintf("%d-%d-%d", rand(), rand(), rand());
474
475 // put common headers
476 // TODO: do we really need this?
477// printf("Message-ID: <%s>\r\n", boundary);
478
479#if ENABLE_FEATURE_SENDMAIL_MAILX
480 // have attachments? -> compose multipart MIME
481 if (opt_attachments) {
482 const char *fmt;
483 const char *p;
484 char *q;
485
486 printf(
487 "Mime-Version: 1.0\r\n"
488 "%smultipart/mixed; boundary=\"%s\"\r\n"
489 , "Content-Type: "
490 , boundary
491 );
492
493 // body is pseudo attachment read from stdin in first turn
494 llist_add_to(&opt_attachments, (char *)"-");
495
496 // put body + attachment(s)
497 // N.B. all these weird things just to be tiny
498 // by reusing string patterns!
499 fmt =
500 "\r\n--%s\r\n"
501 "%stext/plain; charset=%s\r\n"
502 "%s%s\r\n"
503 "%s"
504 ;
505 p = opt_charset;
506 q = (char *)"";
507 l = opt_attachments;
508 while (l) {
509 printf(
510 fmt
511 , boundary
512 , "Content-Type: "
513 , p
514 , "Content-Disposition: inline"
515 , q
516 , "Content-Transfer-Encoding: base64\r\n"
517 );
518 p = "";
519 fmt =
520 "\r\n--%s\r\n"
521 "%sapplication/octet-stream%s\r\n"
522 "%s; filename=\"%s\"\r\n"
523 "%s"
524 ;
525 uuencode(l->data, NULL);
526 l = l->link;
527 if (l)
528 q = bb_get_last_path_component_strip(l->data);
529 }
530
531 // put message terminator
532 printf("\r\n--%s--\r\n" "\r\n", boundary);
533
534 // no attachments? -> just dump message
535 } else
536#endif
537 {
538 char *s;
539 // terminate headers
540 printf("\r\n");
541 // put plain text respecting leading dots
542 while ((s = xmalloc_fgetline(fp0)) != NULL) {
543 // escape leading dots
544 // N.B. this feature is implied even if no -i (-oi) switch given
545 // N.B. we need to escape the leading dot regardless of
546 // whether it is single or not character on the line
547 if ('.' == s[0] /*&& '\0' == s[1] */)
548 printf(".");
549 // dump read line
550 printf("%s\r\n", s);
551 }
552 }
553
554 // leave "put message" mode
555 smtp_check(".", 250);
556 // ... and say goodbye
557 smtp_check("QUIT", 221);
558 // cleanup
559 if (ENABLE_FEATURE_CLEAN_UP)
560 fclose(fp0);
561
562 return EXIT_SUCCESS;
563}
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