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
  50 static 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
  69 static void pop3_check(const char *fmt, const char *param)
  70 {
  71         pop3_checkr(fmt, param, NULL);
  72 }
  73
  74 int popmaildir_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  75 int 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 }