1 /* vi: set sw=4 ts=4: */
2 /*
3 * popmaildir: a simple yet powerful POP3 client
4 * Delivers contents of remote mailboxes to local Maildir
5 *
6 * Inspired by original utility by Nikola Vladov
7 *
8 * Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com>
9 *
10 * Licensed under GPLv2, see file LICENSE in this source tree.
11 */
12 //config:config POPMAILDIR
13 //config: bool "popmaildir"
14 //config: default y
15 //config: help
16 //config: Simple yet powerful POP3 mail popper. Delivers content
17 //config: of remote mailboxes to local Maildir.
18 //config:
19 //config:config FEATURE_POPMAILDIR_DELIVERY
20 //config: bool "Allow message filters and custom delivery program"
21 //config: default y
22 //config: depends on POPMAILDIR
23 //config: help
24 //config: Allow to use a custom program to filter the content
25 //config: of the message before actual delivery (-F "prog [args...]").
26 //config: Allow to use a custom program for message actual delivery
27 //config: (-M "prog [args...]").
28
29 //applet:IF_POPMAILDIR(APPLET(popmaildir, BB_DIR_USR_SBIN, BB_SUID_DROP))
30
31 //kbuild:lib-$(CONFIG_POPMAILDIR) += popmaildir.o mail.o
32
33 //usage:#define popmaildir_trivial_usage
34 //usage: "[OPTIONS] MAILDIR [CONN_HELPER ARGS]"
35 //usage:#define popmaildir_full_usage "\n\n"
36 //usage: "Fetch content of remote mailbox to local maildir\n"
37 /* //usage: "\n -b Binary mode. Ignored" */
38 /* //usage: "\n -d Debug. Ignored" */
39 /* //usage: "\n -m Show used memory. Ignored" */
40 /* //usage: "\n -V Show version. Ignored" */
41 /* //usage: "\n -c Use tcpclient. Ignored" */
42 /* //usage: "\n -a Use APOP protocol. Implied. If server supports APOP -> use it" */
43 //usage: "\n -s Skip authorization"
44 //usage: "\n -T Get messages with TOP instead of RETR"
45 //usage: "\n -k Keep retrieved messages on the server"
46 //usage: "\n -t SEC Network timeout"
47 //usage: IF_FEATURE_POPMAILDIR_DELIVERY(
48 //usage: "\n -F \"PROG ARGS\" Filter program (may be repeated)"
49 //usage: "\n -M \"PROG ARGS\" Delivery program"
50 //usage: )
51 //usage: "\n"
52 //usage: "\nFetch from plain POP3 server:"
53 //usage: "\npopmaildir -k DIR nc pop3.server.com 110 <user_and_pass.txt"
54 //usage: "\nFetch from SSLed POP3 server and delete fetched emails:"
55 //usage: "\npopmaildir DIR -- openssl s_client -quiet -connect pop3.server.com:995 <user_and_pass.txt"
56 /* //usage: "\n -R BYTES Remove old messages on the server >= BYTES. Ignored" */
57 /* //usage: "\n -Z N1-N2 Remove messages from N1 to N2 (dangerous). Ignored" */
58 /* //usage: "\n -L BYTES Don't retrieve new messages >= BYTES. Ignored" */
59 /* //usage: "\n -H LINES Type first LINES of a message. Ignored" */
60 //usage:
61 //usage:#define popmaildir_example_usage
62 //usage: "$ popmaildir -k ~/Maildir -- nc pop.drvv.ru 110 [<password_file]\n"
63 //usage: "$ popmaildir ~/Maildir -- openssl s_client -quiet -connect pop.gmail.com:995 [<password_file]\n"
64
65 #include "libbb.h"
66 #include "mail.h"
67
pop3_checkr(const char * fmt,const char * param,char ** ret)68 static void pop3_checkr(const char *fmt, const char *param, char **ret)
69 {
70 char *msg = send_mail_command(fmt, param);
71 char *answer = xmalloc_fgetline(stdin);
72 if (answer && '+' == answer[0]) {
73 free(msg);
74 if (timeout)
75 alarm(0);
76 if (ret) {
77 // skip "+OK "
78 memmove(answer, answer + 4, strlen(answer) - 4);
79 *ret = answer;
80 } else
81 free(answer);
82 return;
83 }
84 bb_error_msg_and_die("%s failed, reply was: %s", msg, answer);
85 }
86
pop3_check(const char * fmt,const char * param)87 static void pop3_check(const char *fmt, const char *param)
88 {
89 pop3_checkr(fmt, param, NULL);
90 }
91
92 int popmaildir_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
popmaildir_main(int argc UNUSED_PARAM,char ** argv)93 int popmaildir_main(int argc UNUSED_PARAM, char **argv)
94 {
95 char *buf;
96 unsigned nmsg;
97 char *hostname;
98 pid_t pid;
99 const char *retr;
100 #if ENABLE_FEATURE_POPMAILDIR_DELIVERY
101 const char *delivery;
102 #endif
103 unsigned opt_nlines = 0;
104
105 enum {
106 OPT_b = 1 << 0, // -b binary mode. Ignored
107 OPT_d = 1 << 1, // -d,-dd,-ddd debug. Ignored
108 OPT_m = 1 << 2, // -m show used memory. Ignored
109 OPT_V = 1 << 3, // -V version. Ignored
110 OPT_c = 1 << 4, // -c use tcpclient. Ignored
111 OPT_a = 1 << 5, // -a use APOP protocol
112 OPT_s = 1 << 6, // -s skip authorization
113 OPT_T = 1 << 7, // -T get messages with TOP instead with RETR
114 OPT_k = 1 << 8, // -k keep retrieved messages on the server
115 OPT_t = 1 << 9, // -t90 set timeout to 90 sec
116 OPT_R = 1 << 10, // -R20000 remove old messages on the server >= 20000 bytes (requires -k). Ignored
117 OPT_Z = 1 << 11, // -Z11-23 remove messages from 11 to 23 (dangerous). Ignored
118 OPT_L = 1 << 12, // -L50000 not retrieve new messages >= 50000 bytes. Ignored
119 OPT_H = 1 << 13, // -H30 type first 30 lines of a message; (-L12000 -H30). Ignored
120 OPT_M = 1 << 14, // -M\"program arg1 arg2 ...\"; deliver by program. Treated like -F
121 OPT_F = 1 << 15, // -F\"program arg1 arg2 ...\"; filter by program. Treated like -M
122 };
123
124 // init global variables
125 INIT_G();
126
127 // parse options
128 opt_complementary = "-1:dd";
129 opts = getopt32(argv,
130 "bdmVcasTkt:+" "R:+Z:L:+H:+" IF_FEATURE_POPMAILDIR_DELIVERY("M:F:"),
131 &timeout, NULL, NULL, NULL, &opt_nlines
132 IF_FEATURE_POPMAILDIR_DELIVERY(, &delivery, &delivery) // we treat -M and -F the same
133 );
134 //argc -= optind;
135 argv += optind;
136
137 // get auth info
138 if (!(opts & OPT_s))
139 get_cred_or_die(STDIN_FILENO);
140
141 // goto maildir
142 xchdir(*argv++);
143
144 // launch connect helper, if any
145 if (*argv)
146 launch_helper((const char **)argv);
147
148 // get server greeting
149 pop3_checkr(NULL, NULL, &buf);
150
151 // authenticate (if no -s given)
152 if (!(opts & OPT_s)) {
153 // server supports APOP and we want it?
154 if ('<' == buf[0] && (opts & OPT_a)) {
155 union { // save a bit of stack
156 md5_ctx_t ctx;
157 char hex[16 * 2 + 1];
158 } md5;
159 uint32_t res[16 / 4];
160
161 char *s = strchr(buf, '>');
162 if (s)
163 s[1] = '\0';
164 // get md5 sum of "<stamp>password" string
165 md5_begin(&md5.ctx);
166 md5_hash(&md5.ctx, buf, strlen(buf));
167 md5_hash(&md5.ctx, G.pass, strlen(G.pass));
168 md5_end(&md5.ctx, res);
169 *bin2hex(md5.hex, (char*)res, 16) = '\0';
170 // APOP
171 s = xasprintf("%s %s", G.user, md5.hex);
172 pop3_check("APOP %s", s);
173 free(s);
174 free(buf);
175 // server ignores APOP -> use simple text authentication
176 } else {
177 // USER
178 pop3_check("USER %s", G.user);
179 // PASS
180 pop3_check("PASS %s", G.pass);
181 }
182 }
183
184 // get mailbox statistics
185 pop3_checkr("STAT", NULL, &buf);
186
187 // prepare message filename suffix
188 hostname = safe_gethostname();
189 pid = getpid();
190
191 // get messages counter
192 // NOTE: we don't use xatou(buf) since buf is "nmsg nbytes"
193 // we only need nmsg and atoi is just exactly what we need
194 // if atoi fails to convert buf into number it returns 0
195 // in this case the following loop simply will not be executed
196 nmsg = atoi(buf);
197 free(buf);
198
199 // loop through messages
200 retr = (opts & OPT_T) ? xasprintf("TOP %%u %u", opt_nlines) : "RETR %u";
201 for (; nmsg; nmsg--) {
202
203 char *filename;
204 char *target;
205 char *answer;
206 FILE *fp;
207 #if ENABLE_FEATURE_POPMAILDIR_DELIVERY
208 int rc;
209 #endif
210 // generate unique filename
211 filename = xasprintf("tmp/%llu.%u.%s",
212 monotonic_us(), (unsigned)pid, hostname);
213
214 // retrieve message in ./tmp/ unless filter is specified
215 pop3_check(retr, (const char *)(ptrdiff_t)nmsg);
216
217 #if ENABLE_FEATURE_POPMAILDIR_DELIVERY
218 // delivery helper ordered? -> setup pipe
219 if (opts & (OPT_F|OPT_M)) {
220 // helper will have $FILENAME set to filename
221 xsetenv("FILENAME", filename);
222 fp = popen(delivery, "w");
223 unsetenv("FILENAME");
224 if (!fp) {
225 bb_perror_msg("delivery helper");
226 break;
227 }
228 } else
229 #endif
230 // create and open file filename
231 fp = xfopen_for_write(filename);
232
233 // copy stdin to fp (either filename or delivery helper)
234 while ((answer = xmalloc_fgets_str(stdin, "\r\n")) != NULL) {
235 char *s = answer;
236 if ('.' == answer[0]) {
237 if ('.' == answer[1])
238 s++;
239 else if ('\r' == answer[1] && '\n' == answer[2] && '\0' == answer[3])
240 break;
241 }
242 //*strchrnul(s, '\r') = '\n';
243 fputs(s, fp);
244 free(answer);
245 }
246
247 #if ENABLE_FEATURE_POPMAILDIR_DELIVERY
248 // analyse delivery status
249 if (opts & (OPT_F|OPT_M)) {
250 rc = pclose(fp);
251 if (99 == rc) // 99 means bail out
252 break;
253 // if (rc) // !0 means skip to the next message
254 goto skip;
255 // // 0 means continue
256 } else {
257 // close filename
258 fclose(fp);
259 }
260 #endif
261
262 // delete message from server
263 if (!(opts & OPT_k))
264 pop3_check("DELE %u", (const char*)(ptrdiff_t)nmsg);
265
266 // atomically move message to ./new/
267 target = xstrdup(filename);
268 strncpy(target, "new", 3);
269 // ... or just stop receiving on failure
270 if (rename_or_warn(filename, target))
271 break;
272 free(target);
273
274 #if ENABLE_FEATURE_POPMAILDIR_DELIVERY
275 skip:
276 #endif
277 free(filename);
278 }
279
280 // Bye
281 pop3_check("QUIT", NULL);
282
283 if (ENABLE_FEATURE_CLEAN_UP) {
284 free(G.user);
285 free(G.pass);
286 }
287
288 return EXIT_SUCCESS;
289 }
290