source: MondoRescue/branches/3.2/mindi-busybox/mailutils/popmaildir.c@ 3232

/* 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.
 */

//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:t+:R+:L+:H+";
    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;
}