pop3.c

   1 /*@ S-nail - a mail user agent derived from Berkeley Mail.
   2  *@ POP3 (RFCs 1939, 2595) client.
   3  *
   4  * Copyright (c) 2000-2004 Gunnar Ritter, Freiburg i. Br., Germany.
   5  * Copyright (c) 2012 - 2015 Steffen (Daode) Nurpmeso <sdaoden@users.sf.net>.
   6  */
   7 /*
   8  * Copyright (c) 2002
   9  * Gunnar Ritter.  All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. All advertising materials mentioning features or use of this software
  20  *    must display the following acknowledgement:
  21  *    This product includes software developed by Gunnar Ritter
  22  *    and his contributors.
  23  * 4. Neither the name of Gunnar Ritter nor the names of his contributors
  24  *    may be used to endorse or promote products derived from this software
  25  *    without specific prior written permission.
  26  *
  27  * THIS SOFTWARE IS PROVIDED BY GUNNAR RITTER AND CONTRIBUTORS ``AS IS'' AND
  28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  30  * ARE DISCLAIMED.  IN NO EVENT SHALL GUNNAR RITTER OR CONTRIBUTORS BE LIABLE
  31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  37  * SUCH DAMAGE.
  38  */
  39 #undef n_FILE
  40 #define n_FILE pop3
  41
  42 #ifndef HAVE_AMALGAMATION
  43 # include "nail.h"
  44 #endif
  45
  46 EMPTY_FILE()
  47 #ifdef HAVE_POP3
  48
  49 #define POP3_ANSWER(RV,ACTIONSTOP) \
  50 do if (((RV) = pop3_answer(mp)) == STOP) {\
  51    ACTIONSTOP;\
  52 } while (0)
  53
  54 #define POP3_OUT(RV,X,Y,ACTIONSTOP) \
  55 do {\
  56    if (((RV) = pop3_finish(mp)) == STOP) {\
  57       ACTIONSTOP;\
  58    }\
  59    if (options & OPT_VERBVERB)\
  60       n_err(">>> %s", X);\
  61    mp->mb_active |= Y;\
  62    if (((RV) = swrite(&mp->mb_sock, X)) == STOP) {\
  63       ACTIONSTOP;\
  64    }\
  65 } while (0)
  66
  67 static char             *_pop3_buf;
  68 static size_t           _pop3_bufsize;
  69 static sigjmp_buf       _pop3_jmp;
  70 static sighandler_type  _pop3_savealrm;
  71 static int              _pop3_keepalive;
  72 static int volatile     _pop3_lock;
  73
  74 /* Perform entire login handshake */
  75 static enum okay  _pop3_login(struct mailbox *mp, struct sockconn *scp);
  76
  77 /* APOP: get greeting credential or NULL */
  78 #ifdef HAVE_MD5
  79 static char *     _pop3_lookup_apop_timestamp(char const *bp);
  80 #endif
  81
  82 /* Several authentication methods */
  83 #ifdef HAVE_MD5
  84 static enum okay  _pop3_auth_apop(struct mailbox *mp,
  85                      struct sockconn const *scp, char const *ts);
  86 #endif
  87 static enum okay  _pop3_auth_plain(struct mailbox *mp,
  88                      struct sockconn const *scp);
  89
  90 static void       pop3_timer_off(void);
  91 static enum okay  pop3_answer(struct mailbox *mp);
  92 static enum okay  pop3_finish(struct mailbox *mp);
  93 static void       pop3catch(int s);
  94 static void       _pop3_maincatch(int s);
  95 static enum okay  pop3_noop1(struct mailbox *mp);
  96 static void       pop3alarm(int s);
  97 static enum okay  pop3_stat(struct mailbox *mp, off_t *size, int *cnt);
  98 static enum okay  pop3_list(struct mailbox *mp, int n, size_t *size);
  99 static void       pop3_setptr(struct mailbox *mp,
 100                      struct sockconn const *scp);
 101 static enum okay  pop3_get(struct mailbox *mp, struct message *m,
 102                      enum needspec need);
 103 static enum okay  pop3_exit(struct mailbox *mp);
 104 static enum okay  pop3_delete(struct mailbox *mp, int n);
 105 static enum okay  pop3_update(struct mailbox *mp);
 106
 107 static enum okay
 108 _pop3_login(struct mailbox *mp, struct sockconn *scp)
 109 {
 110 #ifdef HAVE_MD5
 111    char *ts;
 112 #endif
 113    enum okey_xlook_mode oxm;
 114    enum okay rv;
 115    NYD_ENTER;
 116
 117    oxm = ok_blook(v15_compat) ? OXM_ALL : OXM_PLAIN | OXM_U_H_P;
 118
 119    /* Get the greeting, check whether APOP is advertised */
 120    POP3_ANSWER(rv, goto jleave);
 121 #ifdef HAVE_MD5
 122    ts = _pop3_lookup_apop_timestamp(_pop3_buf);
 123 #endif
 124
 125    /* If not yet secured, can we upgrade to TLS? */
 126 #ifdef HAVE_SSL
 127    if (!scp->sc_url.url_needs_tls &&
 128          xok_blook(pop3_use_starttls, &scp->sc_url, oxm)) {
 129       POP3_OUT(rv, "STLS" NETNL, MB_COMD, goto jleave);
 130       POP3_ANSWER(rv, goto jleave);
 131       if ((rv = ssl_open(&scp->sc_url, &scp->sc_sock)) != OKAY)
 132          goto jleave;
 133    }
 134 #else
 135    if (xok_blook(pop3_use_starttls, &scp->sc_url, oxm)) {
 136       n_err(_("No SSL support compiled in\n"));
 137       rv = STOP;
 138       goto jleave;
 139    }
 140 #endif
 141
 142    /* Use the APOP single roundtrip? */
 143 #ifdef HAVE_MD5
 144    if (ts != NULL && !xok_blook(pop3_no_apop, &scp->sc_url, oxm)) {
 145       if ((rv = _pop3_auth_apop(mp, scp, ts)) != OKAY) {
 146          char const *ccp;
 147
 148 # ifdef HAVE_SSL
 149          if (scp->sc_sock.s_use_ssl)
 150             ccp = _("over an encrypted connection");
 151          else
 152 # endif
 153             ccp = _("(unsafe clear text!)");
 154          n_err(_("POP3 APOP authentication failed!\n"
 155             "  Server indicated support..  Set *pop3-no-apop*\n"
 156             "  for plain text authentication %s\n"), ccp);
 157       }
 158       goto jleave;
 159    }
 160 #endif
 161
 162    rv = _pop3_auth_plain(mp, scp);
 163 jleave:
 164    NYD_LEAVE;
 165    return rv;
 166 }
 167
 168 #ifdef HAVE_MD5
 169 static char *
 170 _pop3_lookup_apop_timestamp(char const *bp)
 171 {
 172    /* RFC 1939:
 173     * A POP3 server which implements the APOP command will include
 174     * a timestamp in its banner greeting.  The syntax of the timestamp
 175     * corresponds to the "msg-id" in [RFC822]
 176     * RFC 822:
 177     * msg-id   = "<" addr-spec ">"
 178     * addr-spec   = local-part "@" domain */
 179    char const *cp, *ep;
 180    size_t tl;
 181    char *rp = NULL;
 182    bool_t hadat = FAL0;
 183    NYD_ENTER;
 184
 185    if ((cp = strchr(bp, '<')) == NULL)
 186       goto jleave;
 187
 188    /* xxx What about malformed APOP timestamp (<@>) here? */
 189    for (ep = cp; *ep != '\0'; ++ep) {
 190       if (spacechar(*ep))
 191          goto jleave;
 192       else if (*ep == '@')
 193          hadat = TRU1;
 194       else if (*ep == '>') {
 195          if (!hadat)
 196             goto jleave;
 197          break;
 198       }
 199    }
 200    if (*ep != '>')
 201       goto jleave;
 202
 203    tl = PTR2SIZE(++ep - cp);
 204    rp = salloc(tl +1);
 205    memcpy(rp, cp, tl);
 206    rp[tl] = '\0';
 207 jleave:
 208    NYD_LEAVE;
 209    return rp;
 210 }
 211 #endif
 212
 213 #ifdef HAVE_MD5
 214 static enum okay
 215 _pop3_auth_apop(struct mailbox *mp, struct sockconn const *scp, char const *ts)
 216 {
 217    unsigned char digest[16];
 218    char hex[MD5TOHEX_SIZE], *cp;
 219    md5_ctx ctx;
 220    size_t i;
 221    enum okay rv = STOP;
 222    NYD_ENTER;
 223
 224    md5_init(&ctx);
 225    md5_update(&ctx, (uc_i*)UNCONST(ts), strlen(ts));
 226    md5_update(&ctx, (uc_i*)scp->sc_cred.cc_pass.s, scp->sc_cred.cc_pass.l);
 227    md5_final(digest, &ctx);
 228    md5tohex(hex, digest);
 229
 230    i = scp->sc_cred.cc_user.l;
 231    cp = ac_alloc(5 + i + 1 + MD5TOHEX_SIZE + sizeof(NETNL)-1 +1);
 232
 233    memcpy(cp, "APOP ", 5);
 234    memcpy(cp + 5, scp->sc_cred.cc_user.s, i);
 235    i += 5;
 236    cp[i++] = ' ';
 237    memcpy(cp + i, hex, MD5TOHEX_SIZE);
 238    i += MD5TOHEX_SIZE;
 239    memcpy(cp + i, NETNL, sizeof(NETNL));
 240    POP3_OUT(rv, cp, MB_COMD, goto jleave);
 241    POP3_ANSWER(rv, goto jleave);
 242
 243    rv = OKAY;
 244 jleave:
 245    ac_free(cp);
 246    NYD_LEAVE;
 247    return rv;
 248 }
 249 #endif /* HAVE_MD5 */
 250
 251 static enum okay
 252 _pop3_auth_plain(struct mailbox *mp, struct sockconn const *scp)
 253 {
 254    char *cp;
 255    enum okay rv = STOP;
 256    NYD_ENTER;
 257
 258    /* The USER/PASS plain text version */
 259    cp = ac_alloc(MAX(scp->sc_cred.cc_user.l, scp->sc_cred.cc_pass.l) + 5 +
 260          sizeof(NETNL)-1 +1);
 261
 262    memcpy(cp, "USER ", 5);
 263    memcpy(cp + 5, scp->sc_cred.cc_user.s, scp->sc_cred.cc_user.l);
 264    memcpy(cp + 5 + scp->sc_cred.cc_user.l, NETNL, sizeof(NETNL));
 265    POP3_OUT(rv, cp, MB_COMD, goto jleave);
 266    POP3_ANSWER(rv, goto jleave);
 267
 268    memcpy(cp, "PASS ", 5);
 269    memcpy(cp + 5, scp->sc_cred.cc_pass.s, scp->sc_cred.cc_pass.l);
 270    memcpy(cp + 5 + scp->sc_cred.cc_pass.l, NETNL, sizeof(NETNL));
 271    POP3_OUT(rv, cp, MB_COMD, goto jleave);
 272    POP3_ANSWER(rv, goto jleave);
 273
 274    rv = OKAY;
 275 jleave:
 276    ac_free(cp);
 277    NYD_LEAVE;
 278    return rv;
 279 }
 280
 281 static void
 282 pop3_timer_off(void)
 283 {
 284    NYD_ENTER;
 285    if (_pop3_keepalive > 0) {
 286       alarm(0);
 287       safe_signal(SIGALRM, _pop3_savealrm);
 288    }
 289    NYD_LEAVE;
 290 }
 291
 292 static enum okay
 293 pop3_answer(struct mailbox *mp)
 294 {
 295    int sz;
 296    size_t blen;
 297    enum okay rv = STOP;
 298    NYD_ENTER;
 299
 300 jretry:
 301    if ((sz = sgetline(&_pop3_buf, &_pop3_bufsize, &blen, &mp->mb_sock)) > 0) {
 302       if ((mp->mb_active & (MB_COMD | MB_MULT)) == MB_MULT)
 303          goto jmultiline;
 304       if (options & OPT_VERBVERB)
 305          n_err(_pop3_buf);
 306       switch (*_pop3_buf) {
 307       case '+':
 308          rv = OKAY;
 309          mp->mb_active &= ~MB_COMD;
 310          break;
 311       case '-':
 312          rv = STOP;
 313          mp->mb_active = MB_NONE;
 314          while (blen > 0 &&
 315                (_pop3_buf[blen - 1] == NETNL[0] ||
 316                 _pop3_buf[blen - 1] == NETNL[1]))
 317             _pop3_buf[--blen] = '\0';
 318          n_err(_("POP3 error: %s\n"), _pop3_buf);
 319          break;
 320       default:
 321          /* If the answer starts neither with '+' nor with '-', it must be part
 322           * of a multiline response.  Get lines until a single dot appears */
 323 jmultiline:
 324          while (_pop3_buf[0] != '.' || _pop3_buf[1] != NETNL[0] ||
 325                _pop3_buf[2] != NETNL[1] || _pop3_buf[3] != '\0') {
 326             sz = sgetline(&_pop3_buf, &_pop3_bufsize, NULL, &mp->mb_sock);
 327             if (sz <= 0)
 328                goto jeof;
 329          }
 330          mp->mb_active &= ~MB_MULT;
 331          if (mp->mb_active != MB_NONE)
 332             goto jretry;
 333       }
 334    } else {
 335 jeof:
 336       rv = STOP;
 337       mp->mb_active = MB_NONE;
 338    }
 339    NYD_LEAVE;
 340    return rv;
 341 }
 342
 343 static enum okay
 344 pop3_finish(struct mailbox *mp)
 345 {
 346    NYD_ENTER;
 347    while (mp->mb_sock.s_fd > 0 && mp->mb_active != MB_NONE)
 348       pop3_answer(mp);
 349    NYD_LEAVE;
 350    return OKAY;
 351 }
 352
 353 static void
 354 pop3catch(int s)
 355 {
 356    NYD_X; /* Signal handler */
 357    switch (s) {
 358    case SIGINT:
 359       /*n_err_sighdl(_("Interrupt during POP3 operation\n"));*/
 360       interrupts = 2; /* Force "Interrupt" message shall we onintr(0) */
 361       siglongjmp(_pop3_jmp, 1);
 362       break;
 363    case SIGPIPE:
 364       n_err_sighdl(_("Received SIGPIPE during POP3 operation\n"));
 365       break;
 366    }
 367 }
 368
 369 static void
 370 _pop3_maincatch(int s)
 371 {
 372    NYD_X; /* Signal handler */
 373    UNUSED(s);
 374    if (interrupts++ == 0)
 375       n_err_sighdl(_("\n(Interrupt -- one more to abort operation)\n"));
 376    else
 377       siglongjmp(_pop3_jmp, 1);
 378 }
 379
 380 static enum okay
 381 pop3_noop1(struct mailbox *mp)
 382 {
 383    enum okay rv;
 384    NYD_ENTER;
 385
 386    POP3_OUT(rv, "NOOP" NETNL, MB_COMD, goto jleave);
 387    POP3_ANSWER(rv, goto jleave);
 388 jleave:
 389    NYD_LEAVE;
 390    return rv;
 391 }
 392
 393 static void
 394 pop3alarm(int s)
 395 {
 396    sighandler_type volatile saveint, savepipe;
 397    NYD_X; /* Signal handler */
 398    UNUSED(s);
 399
 400    if (_pop3_lock++ == 0) {
 401       hold_all_sigs();
 402       if ((saveint = safe_signal(SIGINT, SIG_IGN)) != SIG_IGN)
 403          safe_signal(SIGINT, &_pop3_maincatch);
 404       savepipe = safe_signal(SIGPIPE, SIG_IGN);
 405       if (sigsetjmp(_pop3_jmp, 1)) {
 406          interrupts = 0;
 407          safe_signal(SIGINT, saveint);
 408          safe_signal(SIGPIPE, savepipe);
 409          goto jbrk;
 410       }
 411       if (savepipe != SIG_IGN)
 412          safe_signal(SIGPIPE, pop3catch);
 413       rele_all_sigs();
 414       if (pop3_noop1(&mb) != OKAY) {
 415          safe_signal(SIGINT, saveint);
 416          safe_signal(SIGPIPE, savepipe);
 417          goto jleave;
 418       }
 419       safe_signal(SIGINT, saveint);
 420       safe_signal(SIGPIPE, savepipe);
 421    }
 422 jbrk:
 423    alarm(_pop3_keepalive);
 424 jleave:
 425    --_pop3_lock;
 426 }
 427
 428 static enum okay
 429 pop3_stat(struct mailbox *mp, off_t *size, int *cnt)
 430 {
 431    char *cp;
 432    enum okay rv;
 433    NYD_ENTER;
 434
 435    POP3_OUT(rv, "STAT" NETNL, MB_COMD, goto jleave);
 436    POP3_ANSWER(rv, goto jleave);
 437
 438    for (cp = _pop3_buf; *cp != '\0' && !spacechar(*cp); ++cp)
 439       ;
 440    while (*cp != '\0' && spacechar(*cp))
 441       ++cp;
 442
 443    if (*cp != '\0') {
 444       *cnt = (int)strtol(cp, NULL, 10);
 445       while (*cp != '\0' && !spacechar(*cp))
 446          ++cp;
 447       while (*cp != '\0' && spacechar(*cp))
 448          ++cp;
 449       if (*cp != '\0')
 450          *size = (int)strtol(cp, NULL, 10);
 451       else
 452          rv = STOP;
 453    } else
 454       rv = STOP;
 455
 456    if (rv == STOP)
 457       n_err(_("Invalid POP3 STAT response: %s\n"), _pop3_buf);
 458 jleave:
 459    NYD_LEAVE;
 460    return rv;
 461 }
 462
 463 static enum okay
 464 pop3_list(struct mailbox *mp, int n, size_t *size)
 465 {
 466    char o[LINESIZE], *cp;
 467    enum okay rv;
 468    NYD_ENTER;
 469
 470    snprintf(o, sizeof o, "LIST %u" NETNL, n);
 471    POP3_OUT(rv, o, MB_COMD, goto jleave);
 472    POP3_ANSWER(rv, goto jleave);
 473
 474    for (cp = _pop3_buf; *cp != '\0' && !spacechar(*cp); ++cp)
 475       ;
 476    while (*cp != '\0' && spacechar(*cp))
 477       ++cp;
 478    while (*cp != '\0' && !spacechar(*cp))
 479       ++cp;
 480    while (*cp != '\0' && spacechar(*cp))
 481       ++cp;
 482    if (*cp != '\0')
 483       *size = (size_t)strtol(cp, NULL, 10);
 484 jleave:
 485    NYD_LEAVE;
 486    return rv;
 487 }
 488
 489 static void
 490 pop3_setptr(struct mailbox *mp, struct sockconn const *scp)
 491 {
 492    size_t i;
 493    enum needspec ns;
 494    NYD_ENTER;
 495
 496    message = scalloc(msgCount + 1, sizeof *message);
 497    message[msgCount].m_size = 0;
 498    message[msgCount].m_lines = 0;
 499    dot = message; /* (Just do it: avoid crash -- shall i now do ointr(0).. */
 500
 501    for (i = 0; UICMP(z, i, <, msgCount); ++i) {
 502       struct message *m = message + i;
 503       m->m_flag = MUSED | MNEW | MNOFROM | MNEWEST;
 504       m->m_block = 0;
 505       m->m_offset = 0;
 506       m->m_size = m->m_xsize = 0;
 507    }
 508
 509    for (i = 0; UICMP(z, i, <, msgCount); ++i)
 510       if (!pop3_list(mp, i + 1, &message[i].m_xsize))
 511          goto jleave;
 512
 513    /* Force the load of all messages right now */
 514    ns = xok_blook(pop3_bulk_load, &scp->sc_url, OXM_ALL)
 515          ? NEED_BODY : NEED_HEADER;
 516    for (i = 0; UICMP(z, i, <, msgCount); ++i)
 517       if (!pop3_get(mp, message + i, ns))
 518          goto jleave;
 519
 520    srelax_hold();
 521    for (i = 0; UICMP(z, i, <, msgCount); ++i) {
 522       struct message *m = message + i;
 523       char const *cp;
 524
 525       if ((cp = hfield1("status", m)) != NULL)
 526          while (*cp != '\0') {
 527             if (*cp == 'R')
 528                m->m_flag |= MREAD;
 529             else if (*cp == 'O')
 530                m->m_flag &= ~MNEW;
 531             ++cp;
 532          }
 533
 534       substdate(m);
 535       srelax();
 536    }
 537    srelax_rele();
 538
 539    setdot(message);
 540 jleave:
 541    NYD_LEAVE;
 542 }
 543
 544 static enum okay
 545 pop3_get(struct mailbox *mp, struct message *m, enum needspec volatile need)
 546 {
 547    char o[LINESIZE], *line, *lp;
 548    sighandler_type volatile saveint, savepipe;
 549    size_t linesize, linelen, size;
 550    int number, lines;
 551    int volatile emptyline;
 552    off_t offset;
 553    enum okay volatile rv;
 554    NYD_ENTER;
 555
 556    line = NULL; /* TODO line pool */
 557    saveint = savepipe = SIG_IGN;
 558    linesize = 0;
 559    number = (int)PTR2SIZE(m - message + 1);
 560    emptyline = 0;
 561    rv = STOP;
 562
 563    if (mp->mb_sock.s_fd < 0) {
 564       n_err(_("POP3 connection already closed\n"));
 565       ++_pop3_lock;
 566       goto jleave;
 567    }
 568
 569    if (_pop3_lock++ == 0) {
 570       hold_all_sigs();
 571       if ((saveint = safe_signal(SIGINT, SIG_IGN)) != SIG_IGN)
 572          safe_signal(SIGINT, &_pop3_maincatch);
 573       savepipe = safe_signal(SIGPIPE, SIG_IGN);
 574       if (sigsetjmp(_pop3_jmp, 1))
 575          goto jleave;
 576       if (savepipe != SIG_IGN)
 577          safe_signal(SIGPIPE, pop3catch);
 578       rele_all_sigs();
 579    }
 580
 581    fseek(mp->mb_otf, 0L, SEEK_END);
 582    offset = ftell(mp->mb_otf);
 583 jretry:
 584    switch (need) {
 585    case NEED_HEADER:
 586       snprintf(o, sizeof o, "TOP %u 0" NETNL, number);
 587       break;
 588    case NEED_BODY:
 589       snprintf(o, sizeof o, "RETR %u" NETNL, number);
 590       break;
 591    case NEED_UNSPEC:
 592       abort(); /* XXX */
 593    }
 594    POP3_OUT(rv, o, MB_COMD | MB_MULT, goto jleave);
 595
 596    if (pop3_answer(mp) == STOP) {
 597       if (need == NEED_HEADER) {
 598          /* The TOP POP3 command is optional, so retry with entire message */
 599          need = NEED_BODY;
 600          goto jretry;
 601       }
 602       goto jleave;
 603    }
 604
 605    size = 0;
 606    lines = 0;
 607    while (sgetline(&line, &linesize, &linelen, &mp->mb_sock) > 0) {
 608       if (line[0] == '.' && line[1] == NETNL[0] && line[2] == NETNL[1] &&
 609             line[3] == '\0') {
 610          mp->mb_active &= ~MB_MULT;
 611          break;
 612       }
 613       if (line[0] == '.') {
 614          lp = line + 1;
 615          --linelen;
 616       } else
 617          lp = line;
 618       /* TODO >>
 619        * Need to mask 'From ' lines. This cannot be done properly
 620        * since some servers pass them as 'From ' and others as
 621        * '>From '. Although one could identify the first kind of
 622        * server in principle, it is not possible to identify the
 623        * second as '>From ' may also come from a server of the
 624        * first type as actual data. So do what is absolutely
 625        * necessary only - mask 'From '.
 626        *
 627        * If the line is the first line of the message header, it
 628        * is likely a real 'From ' line. In this case, it is just
 629        * ignored since it violates all standards.
 630        * TODO i have *never* seen the latter?!?!?
 631        * TODO <<
 632        */
 633       /* Since we simply copy over data without doing any transfer
 634        * encoding reclassification/adjustment we *have* to perform
 635        * RFC 4155 compliant From_ quoting here */
 636       if (emptyline && is_head(lp, linelen, TRU1)) {
 637          putc('>', mp->mb_otf);
 638          ++size;
 639       }
 640       lines++;
 641       if (lp[linelen-1] == NETNL[1] &&
 642             (linelen == 1 || lp[linelen-2] == NETNL[0])) {
 643          emptyline = linelen <= 2;
 644          if (linelen > 2)
 645             fwrite(lp, 1, linelen - 2, mp->mb_otf);
 646          putc('\n', mp->mb_otf);
 647          size += linelen - 1;
 648       } else {
 649          emptyline = 0;
 650          fwrite(lp, 1, linelen, mp->mb_otf);
 651          size += linelen;
 652       }
 653    }
 654    if (!emptyline) {
 655       /* This is very ugly; but some POP3 daemons don't end a
 656        * message with NETNL NETNL, and we need \n\n for mbox format */
 657       putc('\n', mp->mb_otf);
 658       ++lines;
 659       ++size;
 660    }
 661    m->m_size = size;
 662    m->m_lines = lines;
 663    m->m_block = mailx_blockof(offset);
 664    m->m_offset = mailx_offsetof(offset);
 665    fflush(mp->mb_otf);
 666
 667    switch (need) {
 668    case NEED_HEADER:
 669       m->m_have |= HAVE_HEADER;
 670       break;
 671    case NEED_BODY:
 672       m->m_have |= HAVE_HEADER | HAVE_BODY;
 673       m->m_xlines = m->m_lines;
 674       m->m_xsize = m->m_size;
 675       break;
 676    case NEED_UNSPEC:
 677       break;
 678    }
 679
 680    rv = OKAY;
 681 jleave:
 682    if (line != NULL)
 683       free(line);
 684    if (saveint != SIG_IGN)
 685       safe_signal(SIGINT, saveint);
 686    if (savepipe != SIG_IGN)
 687       safe_signal(SIGPIPE, savepipe);
 688    --_pop3_lock;
 689    NYD_LEAVE;
 690    if (interrupts)
 691       n_raise(SIGINT);
 692    return rv;
 693 }
 694
 695 static enum okay
 696 pop3_exit(struct mailbox *mp)
 697 {
 698    enum okay rv;
 699    NYD_ENTER;
 700
 701    POP3_OUT(rv, "QUIT" NETNL, MB_COMD, goto jleave);
 702    POP3_ANSWER(rv, goto jleave);
 703 jleave:
 704    NYD_LEAVE;
 705    return rv;
 706 }
 707
 708 static enum okay
 709 pop3_delete(struct mailbox *mp, int n)
 710 {
 711    char o[LINESIZE];
 712    enum okay rv;
 713    NYD_ENTER;
 714
 715    snprintf(o, sizeof o, "DELE %u" NETNL, n);
 716    POP3_OUT(rv, o, MB_COMD, goto jleave);
 717    POP3_ANSWER(rv, goto jleave);
 718 jleave:
 719    NYD_LEAVE;
 720    return rv;
 721 }
 722
 723 static enum okay
 724 pop3_update(struct mailbox *mp)
 725 {
 726    struct message *m;
 727    int dodel, c, gotcha, held;
 728    NYD_ENTER;
 729
 730    if (!(pstate & PS_EDIT)) {
 731       holdbits();
 732       c = 0;
 733       for (m = message; PTRCMP(m, <, message + msgCount); ++m)
 734          if (m->m_flag & MBOX)
 735             ++c;
 736       if (c > 0)
 737          makembox();
 738    }
 739
 740    gotcha = held = 0;
 741    for (m = message; PTRCMP(m, <, message + msgCount); ++m) {
 742       if (pstate & PS_EDIT)
 743          dodel = m->m_flag & MDELETED;
 744       else
 745          dodel = !((m->m_flag & MPRESERVE) || !(m->m_flag & MTOUCH));
 746       if (dodel) {
 747          pop3_delete(mp, PTR2SIZE(m - message + 1));
 748          ++gotcha;
 749       } else
 750          ++held;
 751    }
 752
 753    /* C99 */{
 754       char const *dnq;
 755
 756       dnq = n_shell_quote_cp(displayname, FAL0);
 757
 758       if (gotcha && (pstate & PS_EDIT)) {
 759          printf(_("%s "), dnq);
 760          printf((ok_blook(bsdcompat) || ok_blook(bsdmsgs))
 761             ? _("complete\n") : _("updated\n"));
 762       } else if (held && !(pstate & PS_EDIT)) {
 763          if (held == 1)
 764             printf(_("Held 1 message in %s\n"), dnq);
 765          else
 766             printf(_("Held %d messages in %s\n"), held, dnq);
 767       }
 768    }
 769    fflush(stdout);
 770    NYD_LEAVE;
 771    return OKAY;
 772 }
 773
 774 FL enum okay
 775 pop3_noop(void)
 776 {
 777    sighandler_type volatile saveint, savepipe;
 778    enum okay volatile rv = STOP;
 779    NYD_ENTER;
 780
 781    _pop3_lock = 1;
 782    hold_all_sigs();
 783    if ((saveint = safe_signal(SIGINT, SIG_IGN)) != SIG_IGN)
 784       safe_signal(SIGINT, &_pop3_maincatch);
 785    savepipe = safe_signal(SIGPIPE, SIG_IGN);
 786    if (sigsetjmp(_pop3_jmp, 1) == 0) {
 787       if (savepipe != SIG_IGN)
 788          safe_signal(SIGPIPE, pop3catch);
 789       rele_all_sigs();
 790       rv = pop3_noop1(&mb);
 791    }
 792    safe_signal(SIGINT, saveint);
 793    safe_signal(SIGPIPE, savepipe);
 794    _pop3_lock = 0;
 795    NYD_LEAVE;
 796    return rv;
 797 }
 798
 799 FL int
 800 pop3_setfile(char const *server, enum fedit_mode fm)
 801 {
 802    struct sockconn sc;
 803    sighandler_type saveint, savepipe;
 804    char const *cp;
 805    int volatile rv;
 806    NYD_ENTER;
 807
 808    rv = 1;
 809    if (fm & FEDIT_NEWMAIL)
 810       goto jleave;
 811    rv = -1;
 812
 813    if (!url_parse(&sc.sc_url, CPROTO_POP3, server))
 814       goto jleave;
 815    if (!ok_blook(v15_compat) &&
 816          (!sc.sc_url.url_had_user || sc.sc_url.url_pass.s != NULL)) {
 817       n_err(_("New-style URL used without *v15-compat* being set\n"));
 818       goto jleave;
 819    }
 820
 821    if (!(ok_blook(v15_compat) ? ccred_lookup(&sc.sc_cred, &sc.sc_url)
 822          : ccred_lookup_old(&sc.sc_cred, CPROTO_POP3,
 823             (sc.sc_url.url_had_user ? sc.sc_url.url_eu_h_p.s
 824              : sc.sc_url.url_u_h_p.s))))
 825       goto jleave;
 826
 827    if (!quit())
 828       goto jleave;
 829
 830    if (!sopen(&sc.sc_sock, &sc.sc_url))
 831       goto jleave;
 832
 833    rv = 1;
 834
 835    if (fm & FEDIT_SYSBOX)
 836       pstate &= ~PS_EDIT;
 837    else
 838       pstate |= PS_EDIT;
 839    if (mb.mb_sock.s_fd >= 0)
 840       sclose(&mb.mb_sock);
 841    if (mb.mb_itf) {
 842       fclose(mb.mb_itf);
 843       mb.mb_itf = NULL;
 844    }
 845    if (mb.mb_otf) {
 846       fclose(mb.mb_otf);
 847       mb.mb_otf = NULL;
 848    }
 849
 850    initbox(sc.sc_url.url_p_u_h_p);
 851    mb.mb_type = MB_VOID;
 852    _pop3_lock = 1;
 853    mb.mb_sock = sc.sc_sock;
 854
 855    saveint = safe_signal(SIGINT, SIG_IGN);
 856    savepipe = safe_signal(SIGPIPE, SIG_IGN);
 857    if (sigsetjmp(_pop3_jmp, 1)) {
 858       sclose(&mb.mb_sock);
 859       n_err(_("POP3 connection closed\n"));
 860       safe_signal(SIGINT, saveint);
 861       safe_signal(SIGPIPE, savepipe);
 862       _pop3_lock = 0;
 863       rv = -1;
 864       if (interrupts > 0)
 865          n_raise(SIGINT);
 866       goto jleave;
 867    }
 868    if (saveint != SIG_IGN)
 869       safe_signal(SIGINT, pop3catch);
 870    if (savepipe != SIG_IGN)
 871       safe_signal(SIGPIPE, pop3catch);
 872
 873    if ((cp = xok_vlook(pop3_keepalive, &sc.sc_url, OXM_ALL)) != NULL) {
 874       if ((_pop3_keepalive = (int)strtol(cp, NULL, 10)) > 0) {
 875          _pop3_savealrm = safe_signal(SIGALRM, pop3alarm);
 876          alarm(_pop3_keepalive);
 877       }
 878    }
 879
 880    mb.mb_sock.s_desc = sc.sc_url.url_needs_tls ? "POP3S" : "POP3";
 881    mb.mb_sock.s_onclose = pop3_timer_off;
 882    if (_pop3_login(&mb, &sc) != OKAY ||
 883          pop3_stat(&mb, &mailsize, &msgCount) != OKAY) {
 884       sclose(&mb.mb_sock);
 885       pop3_timer_off();
 886       safe_signal(SIGINT, saveint);
 887       safe_signal(SIGPIPE, savepipe);
 888       _pop3_lock = 0;
 889       goto jleave;
 890    }
 891
 892    setmsize(msgCount);
 893    mb.mb_type = MB_POP3;
 894    mb.mb_perm = ((options & OPT_R_FLAG) || (fm & FEDIT_RDONLY)) ? 0 : MB_DELE;
 895    pop3_setptr(&mb, &sc);
 896
 897    /*if (!(fm & FEDIT_NEWMAIL)) */{
 898       pstate &= ~PS_SAW_COMMAND;
 899       pstate |= PS_SETFILE_OPENED;
 900    }
 901
 902    safe_signal(SIGINT, saveint);
 903    safe_signal(SIGPIPE, savepipe);
 904    _pop3_lock = 0;
 905
 906    if ((options & OPT_EXISTONLY) && !(options & OPT_HEADERLIST)) {
 907       rv = (msgCount == 0);
 908       goto jleave;
 909    }
 910
 911    if (!(pstate & PS_EDIT) && msgCount == 0) {
 912       if (!ok_blook(emptystart))
 913          n_err(_("No mail at %s\n"), server);
 914       goto jleave;
 915    }
 916
 917    rv = 0;
 918 jleave:
 919    NYD_LEAVE;
 920    return rv;
 921 }
 922
 923 FL enum okay
 924 pop3_header(struct message *m)
 925 {
 926    enum okay rv;
 927    NYD_ENTER;
 928
 929    /* TODO no URL here, no OXM possible; (however it is used in setfile()..) */
 930    rv = pop3_get(&mb, m, (ok_blook(pop3_bulk_load) ? NEED_BODY : NEED_HEADER));
 931    NYD_LEAVE;
 932    return rv;
 933 }
 934
 935 FL enum okay
 936 pop3_body(struct message *m)
 937 {
 938    enum okay rv;
 939    NYD_ENTER;
 940
 941    rv = pop3_get(&mb, m, NEED_BODY);
 942    NYD_LEAVE;
 943    return rv;
 944 }
 945
 946 FL bool_t
 947 pop3_quit(void)
 948 {
 949    sighandler_type volatile saveint, savepipe;
 950    bool_t rv;
 951    NYD_ENTER;
 952
 953    rv = FAL0;
 954
 955    if (mb.mb_sock.s_fd < 0) {
 956       n_err(_("POP3 connection already closed\n"));
 957       rv = TRU1;
 958       goto jleave;
 959    }
 960
 961    _pop3_lock = 1;
 962    saveint = safe_signal(SIGINT, SIG_IGN);
 963    savepipe = safe_signal(SIGPIPE, SIG_IGN);
 964    if (sigsetjmp(_pop3_jmp, 1)) {
 965       safe_signal(SIGINT, saveint);
 966       safe_signal(SIGPIPE, savepipe);
 967       _pop3_lock = 0;
 968       interrupts = 0;
 969       goto jleave;
 970    }
 971    if (saveint != SIG_IGN)
 972       safe_signal(SIGINT, pop3catch);
 973    if (savepipe != SIG_IGN)
 974       safe_signal(SIGPIPE, pop3catch);
 975    pop3_update(&mb);
 976    pop3_exit(&mb);
 977    sclose(&mb.mb_sock);
 978    safe_signal(SIGINT, saveint);
 979    safe_signal(SIGPIPE, savepipe);
 980    _pop3_lock = 0;
 981
 982    rv = TRU1;
 983 jleave:
 984    NYD_LEAVE;
 985    return rv;
 986 }
 987 #endif /* HAVE_POP3 */
 988
 989 /* s-it-mode */