LXR busybox/mailutils/popmaildir.c

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