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