busybox/mailutils/popmaildir.c
Denys Vlasenko 9a2d899273 ntpd: fix refid reported in server mode, closes 13056
function                                             old     new   delta
resolve_peer_hostname                                129     196     +67
recv_and_process_peer_pkt                           2475    2476      +1
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 68/0)               Total: 68 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-07-20 00:04:33 +02:00

290 lines
8.5 KiB
C

/* 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
opts = getopt32(argv, "^"
"bdmVcasTkt:+" "R:+Z:L:+H:+" IF_FEATURE_POPMAILDIR_DELIVERY("M:F:")
"\0" "-1:dd",
&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[MD5_OUTSIZE / 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_simple_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);
memcpy(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;
}