summaryrefslogtreecommitdiff
path: root/mailutils/popmaildir.c
blob: 1695a9bb8d3d7f1d48c7ac866ff400cadbb48036 (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
/* vi: set sw=4 ts=4: */
/*
 * popmaildir: a simple yet powerful POP3 client
 * Delivers contents of remote mailboxes to local Maildir
 *
 * Inspired by original utility by Nikola Vladov
 *
 * Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com>
 *
 * Licensed under GPLv2, see file LICENSE in this source tree.
 */
//config:config POPMAILDIR
//config:	bool "popmaildir (10 kb)"
//config:	default y
//config:	help
//config:	Simple yet powerful POP3 mail popper. Delivers content
//config:	of remote mailboxes to local Maildir.
//config:
//config:config FEATURE_POPMAILDIR_DELIVERY
//config:	bool "Allow message filters and custom delivery program"
//config:	default y
//config:	depends on POPMAILDIR
//config:	help
//config:	Allow to use a custom program to filter the content
//config:	of the message before actual delivery (-F "prog [args...]").
//config:	Allow to use a custom program for message actual delivery
//config:	(-M "prog [args...]").

//applet:IF_POPMAILDIR(APPLET(popmaildir, BB_DIR_USR_SBIN, BB_SUID_DROP))

//kbuild:lib-$(CONFIG_POPMAILDIR) += popmaildir.o mail.o

//usage:#define popmaildir_trivial_usage
//usage:       "[OPTIONS] MAILDIR [CONN_HELPER ARGS]"
//usage:#define popmaildir_full_usage "\n\n"
//usage:       "Fetch content of remote mailbox to local maildir\n"
/* //usage:  "\n	-b		Binary mode. Ignored" */
/* //usage:  "\n	-d		Debug. Ignored" */
/* //usage:  "\n	-m		Show used memory. Ignored" */
/* //usage:  "\n	-V		Show version. Ignored" */
/* //usage:  "\n	-c		Use tcpclient. Ignored" */
/* //usage:  "\n	-a		Use APOP protocol. Implied. If server supports APOP -> use it" */
//usage:     "\n	-s		Skip authorization"
//usage:     "\n	-T		Get messages with TOP instead of RETR"
//usage:     "\n	-k		Keep retrieved messages on the server"
//usage:     "\n	-t SEC		Network timeout"
//usage:	IF_FEATURE_POPMAILDIR_DELIVERY(
//usage:     "\n	-F \"PROG ARGS\"	Filter program (may be repeated)"
//usage:     "\n	-M \"PROG ARGS\"	Delivery program"
//usage:	)
//usage:     "\n"
//usage:     "\nFetch from plain POP3 server:"
//usage:     "\npopmaildir -k DIR nc pop3.server.com 110 <user_and_pass.txt"
//usage:     "\nFetch from SSLed POP3 server and delete fetched emails:"
//usage:     "\npopmaildir DIR -- openssl s_client -quiet -connect pop3.server.com:995 <user_and_pass.txt"
/* //usage:  "\n	-R BYTES	Remove old messages on the server >= BYTES. Ignored" */
/* //usage:  "\n	-Z N1-N2	Remove messages from N1 to N2 (dangerous). Ignored" */
/* //usage:  "\n	-L BYTES	Don't retrieve new messages >= BYTES. Ignored" */
/* //usage:  "\n	-H LINES	Type first LINES of a message. Ignored" */
//usage:
//usage:#define popmaildir_example_usage
//usage:       "$ popmaildir -k ~/Maildir -- nc pop.drvv.ru 110 [<password_file]\n"
//usage:       "$ popmaildir ~/Maildir -- openssl s_client -quiet -connect pop.gmail.com:995 [<password_file]\n"

#include "libbb.h"
#include "mail.h"

static void pop3_checkr(const char *fmt, const char *param, char **ret)
{
	char *msg = send_mail_command(fmt, param);
	char *answer = xmalloc_fgetline(stdin);
	if (answer && '+' == answer[0]) {
		free(msg);
		if (timeout)
			alarm(0);
		if (ret) {
			// skip "+OK "
			memmove(answer, answer + 4, strlen(answer) - 4);
			*ret = answer;
		} else
			free(answer);
		return;
	}
	bb_error_msg_and_die("%s failed, reply was: %s", msg, answer);
}

static void pop3_check(const char *fmt, const char *param)
{
	pop3_checkr(fmt, param, NULL);
}

int popmaildir_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int popmaildir_main(int argc UNUSED_PARAM, char **argv)
{
	char *buf;
	unsigned nmsg;
	char *hostname;
	pid_t pid;
	const char *retr;
#if ENABLE_FEATURE_POPMAILDIR_DELIVERY
	const char *delivery;
#endif
	unsigned opt_nlines = 0;

	enum {
		OPT_b = 1 << 0,		// -b binary mode. Ignored
		OPT_d = 1 << 1,		// -d,-dd,-ddd debug. Ignored
		OPT_m = 1 << 2,		// -m show used memory. Ignored
		OPT_V = 1 << 3,		// -V version. Ignored
		OPT_c = 1 << 4,		// -c use tcpclient. Ignored
		OPT_a = 1 << 5,		// -a use APOP protocol
		OPT_s = 1 << 6,		// -s skip authorization
		OPT_T = 1 << 7,		// -T get messages with TOP instead with RETR
		OPT_k = 1 << 8,		// -k keep retrieved messages on the server
		OPT_t = 1 << 9,		// -t90 set timeout to 90 sec
		OPT_R = 1 << 10,	// -R20000 remove old messages on the server >= 20000 bytes (requires -k). Ignored
		OPT_Z = 1 << 11,	// -Z11-23 remove messages from 11 to 23 (dangerous). Ignored
		OPT_L = 1 << 12,	// -L50000 not retrieve new messages >= 50000 bytes. Ignored
		OPT_H = 1 << 13,	// -H30 type first 30 lines of a message; (-L12000 -H30). Ignored
		OPT_M = 1 << 14,	// -M\"program arg1 arg2 ...\"; deliver by program. Treated like -F
		OPT_F = 1 << 15,	// -F\"program arg1 arg2 ...\"; filter by program. Treated like -M
	};

	// init global variables
	INIT_G();

	// parse options
	opt_complementary = "-1:dd";
	opts = getopt32(argv,
		"bdmVcasTkt:+" "R:+Z:L:+H:+" IF_FEATURE_POPMAILDIR_DELIVERY("M:F:"),
		&timeout, NULL, NULL, NULL, &opt_nlines
		IF_FEATURE_POPMAILDIR_DELIVERY(, &delivery, &delivery) // we treat -M and -F the same
	);
	//argc -= optind;
	argv += optind;

	// get auth info
	if (!(opts & OPT_s))
		get_cred_or_die(STDIN_FILENO);

	// goto maildir
	xchdir(*argv++);

	// launch connect helper, if any
	if (*argv)
		launch_helper((const char **)argv);

	// get server greeting
	pop3_checkr(NULL, NULL, &buf);

	// authenticate (if no -s given)
	if (!(opts & OPT_s)) {
		// server supports APOP and we want it?
		if ('<' == buf[0] && (opts & OPT_a)) {
			union { // save a bit of stack
				md5_ctx_t ctx;
				char hex[16 * 2 + 1];
			} md5;
			uint32_t res[16 / 4];

			char *s = strchr(buf, '>');
			if (s)
				s[1] = '\0';
			// get md5 sum of "<stamp>password" string
			md5_begin(&md5.ctx);
			md5_hash(&md5.ctx, buf, strlen(buf));
			md5_hash(&md5.ctx, G.pass, strlen(G.pass));
			md5_end(&md5.ctx, res);
			*bin2hex(md5.hex, (char*)res, 16) = '\0';
			// APOP
			s = xasprintf("%s %s", G.user, md5.hex);
			pop3_check("APOP %s", s);
			free(s);
			free(buf);
		// server ignores APOP -> use simple text authentication
		} else {
			// USER
			pop3_check("USER %s", G.user);
			// PASS
			pop3_check("PASS %s", G.pass);
		}
	}

	// get mailbox statistics
	pop3_checkr("STAT", NULL, &buf);

	// prepare message filename suffix
	hostname = safe_gethostname();
	pid = getpid();

	// get messages counter
	// NOTE: we don't use xatou(buf) since buf is "nmsg nbytes"
	// we only need nmsg and atoi is just exactly what we need
	// if atoi fails to convert buf into number it returns 0
	// in this case the following loop simply will not be executed
	nmsg = atoi(buf);
	free(buf);

	// loop through messages
	retr = (opts & OPT_T) ? xasprintf("TOP %%u %u", opt_nlines) : "RETR %u";
	for (; nmsg; nmsg--) {

		char *filename;
		char *target;
		char *answer;
		FILE *fp;
#if ENABLE_FEATURE_POPMAILDIR_DELIVERY
		int rc;
#endif
		// generate unique filename
		filename  = xasprintf("tmp/%llu.%u.%s",
			monotonic_us(), (unsigned)pid, hostname);

		// retrieve message in ./tmp/ unless filter is specified
		pop3_check(retr, (const char *)(ptrdiff_t)nmsg);

#if ENABLE_FEATURE_POPMAILDIR_DELIVERY
		// delivery helper ordered? -> setup pipe
		if (opts & (OPT_F|OPT_M)) {
			// helper will have $FILENAME set to filename
			xsetenv("FILENAME", filename);
			fp = popen(delivery, "w");
			unsetenv("FILENAME");
			if (!fp) {
				bb_perror_msg("delivery helper");
				break;
			}
		} else
#endif
		// create and open file filename
		fp = xfopen_for_write(filename);

		// copy stdin to fp (either filename or delivery helper)
		while ((answer = xmalloc_fgets_str(stdin, "\r\n")) != NULL) {
			char *s = answer;
			if ('.' == answer[0]) {
				if ('.' == answer[1])
					s++;
				else if ('\r' == answer[1] && '\n' == answer[2] && '\0' == answer[3])
					break;
			}
			//*strchrnul(s, '\r') = '\n';
			fputs(s, fp);
			free(answer);
		}

#if ENABLE_FEATURE_POPMAILDIR_DELIVERY
		// analyse delivery status
		if (opts & (OPT_F|OPT_M)) {
			rc = pclose(fp);
			if (99 == rc) // 99 means bail out
				break;
//			if (rc) // !0 means skip to the next message
				goto skip;
//			// 0 means continue
		} else {
			// close filename
			fclose(fp);
		}
#endif

		// delete message from server
		if (!(opts & OPT_k))
			pop3_check("DELE %u", (const char*)(ptrdiff_t)nmsg);

		// atomically move message to ./new/
		target = xstrdup(filename);
		strncpy(target, "new", 3);
		// ... or just stop receiving on failure
		if (rename_or_warn(filename, target))
			break;
		free(target);

#if ENABLE_FEATURE_POPMAILDIR_DELIVERY
 skip:
#endif
		free(filename);
	}

	// Bye
	pop3_check("QUIT", NULL);

	if (ENABLE_FEATURE_CLEAN_UP) {
		free(G.user);
		free(G.pass);
	}

	return EXIT_SUCCESS;
}