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 - 2014 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
  40 #ifndef HAVE_AMALGAMATION
  41 # include "nail.h"
  42 #endif
  43
  44 EMPTY_FILE(pop3)
  45 #ifdef HAVE_POP3
  46
  47 #undef NL
  48 #undef LINE
  49 #define NL        "\015\012"
  50 #define LINE(X)   X NL
  51
  52 #define POP3_ANSWER(RV,ACTIONSTOP) \
  53 do if (((RV) = pop3_answer(mp)) == STOP) {\
  54    ACTIONSTOP;\
  55 } while (0)
  56
  57 #define POP3_OUT(RV,X,Y,ACTIONSTOP) \
  58 do {\
  59    if (((RV) = pop3_finish(mp)) == STOP) {\
  60       ACTIONSTOP;\
  61    }\
  62    if (options & OPT_VERBVERB)\
  63       fprintf(stderr, ">>> %s", X);\
  64    mp->mb_active |= Y;\
  65    if (((RV) = swrite(&mp->mb_sock, X)) == STOP) {\
  66       ACTIONSTOP;\
  67    }\
  68 } while (0)
  69
  70 static char             *_pop3_buf;
  71 static size_t           _pop3_bufsize;
  72 static sigjmp_buf       _pop3_jmp;
  73 static sighandler_type  _pop3_savealrm;
  74 static int              _pop3_keepalive;
  75 static int volatile     _pop3_lock;
  76
  77 /* Perform entire login handshake */
  78 static enum okay  _pop3_login(struct mailbox *mp, struct sockconn *scp);
  79
  80 /* APOP: get greeting credential or NULL */
  81 #ifdef HAVE_MD5
  82 static char *     _pop3_lookup_apop_timestamp(char const *bp);
  83 #endif
  84
  85 static bool_t     _pop3_use_starttls(struct sockconn const *scp);
  86
  87 /* APOP: shall we use it? */
  88 static bool_t     _pop3_no_apop(struct sockconn const *scp);
  89
  90 /* Several authentication methods */
  91 #ifdef HAVE_MD5
  92 static enum okay  _pop3_auth_apop(struct mailbox *mp,
  93                      struct sockconn const *scp, char const *ts);
  94 #endif
  95 static enum okay  _pop3_auth_plain(struct mailbox *mp,
  96                      struct sockconn const *scp);
  97
  98 static void       pop3_timer_off(void);
  99 static enum okay  pop3_answer(struct mailbox *mp);
 100 static enum okay  pop3_finish(struct mailbox *mp);
 101 static void       pop3catch(int s);
 102 static void       _pop3_maincatch(int s);
 103 static enum okay  pop3_noop1(struct mailbox *mp);
 104 static void       pop3alarm(int s);
 105 static enum okay  pop3_stat(struct mailbox *mp, off_t *size, int *cnt);
 106 static enum okay  pop3_list(struct mailbox *mp, int n, size_t *size);
 107 static void       pop3_init(struct mailbox *mp, int n);
 108 static void       pop3_dates(struct mailbox *mp);
 109 static void       pop3_setptr(struct mailbox *mp);
 110 static enum okay  pop3_get(struct mailbox *mp, struct message *m,
 111                      enum needspec need);
 112 static enum okay  pop3_exit(struct mailbox *mp);
 113 static enum okay  pop3_delete(struct mailbox *mp, int n);
 114 static enum okay  pop3_update(struct mailbox *mp);
 115
 116 static enum okay
 117 _pop3_login(struct mailbox *mp, struct sockconn *scp)
 118 {
 119 #ifdef HAVE_MD5
 120    char *ts;
 121 #endif
 122    enum okay rv;
 123    NYD_ENTER;
 124
 125    /* Get the greeting, check wether APOP is advertised */
 126    POP3_ANSWER(rv, goto jleave);
 127 #ifdef HAVE_MD5
 128    ts = _pop3_lookup_apop_timestamp(_pop3_buf);
 129 #endif
 130
 131    /* If not yet secured, can we upgrade to TLS? */
 132 #ifdef HAVE_SSL
 133    if (!scp->sc_url.url_needs_tls && _pop3_use_starttls(scp)) {
 134       POP3_OUT(rv, "STLS" NL, MB_COMD, goto jleave);
 135       POP3_ANSWER(rv, goto jleave);
 136       if ((rv = ssl_open(scp->sc_url.url_host.s, &scp->sc_sock,
 137             scp->sc_url.url_u_h_p.s)) != OKAY)
 138          goto jleave;
 139    }
 140 #else
 141    if (_pop3_use_starttls(scp->sc_url.url_u_h_p.s)) {
 142       fprintf(stderr, "No SSL support compiled in.\n");
 143       rv = STOP;
 144       goto jleave;
 145    }
 146 #endif
 147
 148    /* Use the APOP single roundtrip? */
 149    if (!_pop3_no_apop(scp)) {
 150 #ifdef HAVE_MD5
 151       if (ts != NULL) {
 152          if ((rv = _pop3_auth_apop(mp, scp, ts)) != OKAY)
 153             fprintf(stderr, _("POP3 `APOP' authentication failed, "
 154                "maybe try setting *pop3-no-apop*\n"));
 155          goto jleave;
 156       } else
 157 #endif
 158       if (options & OPT_VERB)
 159          fprintf(stderr, _("No POP3 `APOP' support "
 160             "available, sending password in clear text\n"));
 161    }
 162
 163    rv = _pop3_auth_plain(mp, scp);
 164 jleave:
 165    NYD_LEAVE;
 166    return rv;
 167 }
 168
 169 #ifdef HAVE_MD5
 170 static char *
 171 _pop3_lookup_apop_timestamp(char const *bp)
 172 {
 173    /* RFC 1939:
 174     * A POP3 server which implements the APOP command will include
 175     * a timestamp in its banner greeting.  The syntax of the timestamp
 176     * corresponds to the `msg-id' in [RFC822]
 177     * RFC 822:
 178     * msg-id   = "<" addr-spec ">"
 179     * addr-spec   = local-part "@" domain */
 180    char const *cp, *ep;
 181    size_t tl;
 182    char *rp = NULL;
 183    bool_t hadat = FAL0;
 184    NYD_ENTER;
 185
 186    if ((cp = strchr(bp, '<')) == NULL)
 187       goto jleave;
 188
 189    /* xxx What about malformed APOP timestamp (<@>) here? */
 190    for (ep = cp; *ep != '\0'; ++ep) {
 191       if (spacechar(*ep))
 192          goto jleave;
 193       else if (*ep == '@')
 194          hadat = TRU1;
 195       else if (*ep == '>') {
 196          if (!hadat)
 197             goto jleave;
 198          break;
 199       }
 200    }
 201    if (*ep != '>')
 202       goto jleave;
 203
 204    tl = PTR2SIZE(++ep - cp);
 205    rp = salloc(tl +1);
 206    memcpy(rp, cp, tl);
 207    rp[tl] = '\0';
 208 jleave:
 209    NYD_LEAVE;
 210    return rp;
 211 }
 212 #endif
 213
 214 static bool_t
 215 _pop3_use_starttls(struct sockconn const *scp)
 216 {
 217    bool_t rv;
 218    NYD_ENTER;
 219
 220    if (!(rv = ok_blook(pop3_use_starttls)))
 221       if (!ok_blook(v15_compat) ||
 222             !(rv = vok_blook(savecat("pop3-use-starttls-",
 223                   scp->sc_url.url_h_p.s))))
 224          rv = vok_blook(savecat("pop3-use-starttls-", scp->sc_url.url_u_h_p.s));
 225    NYD_LEAVE;
 226    return rv;
 227 }
 228
 229 static bool_t
 230 _pop3_no_apop(struct sockconn const *scp)
 231 {
 232    bool_t rv;
 233    NYD_ENTER;
 234
 235    if (!(rv = ok_blook(pop3_no_apop)))
 236       if (!ok_blook(v15_compat) ||
 237             !(rv = vok_blook(savecat("pop3-no-apop-", scp->sc_url.url_h_p.s))))
 238          rv = vok_blook(savecat("pop3-no-apop-", scp->sc_url.url_u_h_p.s));
 239    NYD_LEAVE;
 240    return rv;
 241 }
 242
 243 #ifdef HAVE_MD5
 244 static enum okay
 245 _pop3_auth_apop(struct mailbox *mp, struct sockconn const *scp, char const *ts)
 246 {
 247    unsigned char digest[16];
 248    char hex[MD5TOHEX_SIZE], *cp;
 249    md5_ctx ctx;
 250    size_t i;
 251    enum okay rv = STOP;
 252    NYD_ENTER;
 253
 254    md5_init(&ctx);
 255    md5_update(&ctx, (uc_it*)UNCONST(ts), strlen(ts));
 256    md5_update(&ctx, (uc_it*)scp->sc_cred.cc_pass.s,
 257       scp->sc_cred.cc_pass.l);
 258    md5_final(digest, &ctx);
 259    md5tohex(hex, digest);
 260
 261    i = scp->sc_cred.cc_user.l;
 262    cp = ac_alloc(5 + i + 1 + MD5TOHEX_SIZE + sizeof(NL)-1 +1);
 263
 264    memcpy(cp, "APOP ", 5);
 265    memcpy(cp + 5, scp->sc_cred.cc_user.s, i);
 266    i += 5;
 267    cp[i++] = ' ';
 268    memcpy(cp + i, hex, MD5TOHEX_SIZE);
 269    i += MD5TOHEX_SIZE;
 270    memcpy(cp + i, NL, sizeof(NL));
 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 #endif /* HAVE_MD5 */
 281
 282 static enum okay
 283 _pop3_auth_plain(struct mailbox *mp, struct sockconn const *scp)
 284 {
 285    char *cp;
 286    enum okay rv = STOP;
 287    NYD_ENTER;
 288
 289    /* The USER/PASS plain text version */
 290    cp = ac_alloc(MAX(scp->sc_cred.cc_user.l, scp->sc_cred.cc_pass.l) + 5 +
 291          sizeof(NL)-1 +1);
 292
 293    memcpy(cp, "USER ", 5);
 294    memcpy(cp + 5, scp->sc_cred.cc_user.s, scp->sc_cred.cc_user.l);
 295    memcpy(cp + 5 + scp->sc_cred.cc_user.l, NL, sizeof(NL));
 296    POP3_OUT(rv, cp, MB_COMD, goto jleave);
 297    POP3_ANSWER(rv, goto jleave);
 298
 299    memcpy(cp, "PASS ", 5);
 300    memcpy(cp + 5, scp->sc_cred.cc_pass.s, scp->sc_cred.cc_pass.l);
 301    memcpy(cp + 5 + scp->sc_cred.cc_pass.l, NL, sizeof(NL));
 302    POP3_OUT(rv, cp, MB_COMD, goto jleave);
 303    POP3_ANSWER(rv, goto jleave);
 304
 305    rv = OKAY;
 306 jleave:
 307    ac_free(cp);
 308    NYD_LEAVE;
 309    return rv;
 310 }
 311
 312 static void
 313 pop3_timer_off(void)
 314 {
 315    NYD_ENTER;
 316    if (_pop3_keepalive > 0) {
 317       alarm(0);
 318       safe_signal(SIGALRM, _pop3_savealrm);
 319    }
 320    NYD_LEAVE;
 321 }
 322
 323 static enum okay
 324 pop3_answer(struct mailbox *mp)
 325 {
 326    int sz;
 327    enum okay rv = STOP;
 328    NYD_ENTER;
 329
 330 jretry:
 331    if ((sz = sgetline(&_pop3_buf, &_pop3_bufsize, NULL, &mp->mb_sock)) > 0) {
 332       if ((mp->mb_active & (MB_COMD | MB_MULT)) == MB_MULT)
 333          goto jmultiline;
 334       if (options & OPT_VERBVERB)
 335          fputs(_pop3_buf, stderr);
 336       switch (*_pop3_buf) {
 337       case '+':
 338          rv = OKAY;
 339          mp->mb_active &= ~MB_COMD;
 340          break;
 341       case '-':
 342          rv = STOP;
 343          mp->mb_active = MB_NONE;
 344          fprintf(stderr, _("POP3 error: %s"), _pop3_buf);
 345          break;
 346       default:
 347          /* If the answer starts neither with '+' nor with '-', it must be part
 348           * of a multiline response.  Get lines until a single dot appears */
 349 jmultiline:
 350          while (_pop3_buf[0] != '.' || _pop3_buf[1] != NL[0] ||
 351                _pop3_buf[2] != NL[1] || _pop3_buf[3] != '\0') {
 352             sz = sgetline(&_pop3_buf, &_pop3_bufsize, NULL, &mp->mb_sock);
 353             if (sz <= 0)
 354                goto jeof;
 355          }
 356          mp->mb_active &= ~MB_MULT;
 357          if (mp->mb_active != MB_NONE)
 358             goto jretry;
 359       }
 360    } else {
 361 jeof:
 362       rv = STOP;
 363       mp->mb_active = MB_NONE;
 364    }
 365    NYD_LEAVE;
 366    return rv;
 367 }
 368
 369 static enum okay
 370 pop3_finish(struct mailbox *mp)
 371 {
 372    NYD_ENTER;
 373    while (mp->mb_sock.s_fd > 0 && mp->mb_active != MB_NONE)
 374       pop3_answer(mp);
 375    NYD_LEAVE;
 376    return OKAY;
 377 }
 378
 379 static void
 380 pop3catch(int s)
 381 {
 382    NYD_X; /* Signal handler */
 383    switch (s) {
 384    case SIGINT:
 385       fprintf(stderr, _("Interrupt\n"));
 386       siglongjmp(_pop3_jmp, 1);
 387       break;
 388    case SIGPIPE:
 389       fprintf(stderr, "Received SIGPIPE during POP3 operation\n");
 390       break;
 391    }
 392 }
 393
 394 static void
 395 _pop3_maincatch(int s)
 396 {
 397    NYD_X; /* Signal handler */
 398    UNUSED(s);
 399
 400    if (interrupts++ == 0)
 401       fprintf(stderr, _("Interrupt\n"));
 402    else
 403       onintr(0);
 404 }
 405
 406 static enum okay
 407 pop3_noop1(struct mailbox *mp)
 408 {
 409    enum okay rv;
 410    NYD_ENTER;
 411
 412    POP3_OUT(rv, "NOOP" NL, MB_COMD, goto jleave);
 413    POP3_ANSWER(rv, goto jleave);
 414 jleave:
 415    NYD_LEAVE;
 416    return rv;
 417 }
 418
 419 static void
 420 pop3alarm(int s)
 421 {
 422    sighandler_type volatile saveint, savepipe;
 423    NYD_X; /* Signal handler */
 424    UNUSED(s);
 425
 426    if (_pop3_lock++ == 0) {
 427       if ((saveint = safe_signal(SIGINT, SIG_IGN)) != SIG_IGN)
 428          safe_signal(SIGINT, &_pop3_maincatch);
 429       savepipe = safe_signal(SIGPIPE, SIG_IGN);
 430       if (sigsetjmp(_pop3_jmp, 1)) {
 431          safe_signal(SIGINT, saveint);
 432          safe_signal(SIGPIPE, savepipe);
 433          goto jbrk;
 434       }
 435       if (savepipe != SIG_IGN)
 436          safe_signal(SIGPIPE, pop3catch);
 437       if (pop3_noop1(&mb) != OKAY) {
 438          safe_signal(SIGINT, saveint);
 439          safe_signal(SIGPIPE, savepipe);
 440          goto jleave;
 441       }
 442       safe_signal(SIGINT, saveint);
 443       safe_signal(SIGPIPE, savepipe);
 444    }
 445 jbrk:
 446    alarm(_pop3_keepalive);
 447 jleave:
 448    --_pop3_lock;
 449 }
 450
 451 static enum okay
 452 pop3_stat(struct mailbox *mp, off_t *size, int *cnt)
 453 {
 454    char *cp;
 455    enum okay rv;
 456    NYD_ENTER;
 457
 458    POP3_OUT(rv, "STAT" NL, MB_COMD, goto jleave);
 459    POP3_ANSWER(rv, goto jleave);
 460
 461    for (cp = _pop3_buf; *cp != '\0' && !spacechar(*cp); ++cp)
 462       ;
 463    while (*cp != '\0' && spacechar(*cp))
 464       ++cp;
 465
 466    if (*cp != '\0') {
 467       *cnt = (int)strtol(cp, NULL, 10);
 468       while (*cp != '\0' && !spacechar(*cp))
 469          ++cp;
 470       while (*cp != '\0' && spacechar(*cp))
 471          ++cp;
 472       if (*cp != '\0')
 473          *size = (int)strtol(cp, NULL, 10);
 474       else
 475          rv = STOP;
 476    } else
 477       rv = STOP;
 478
 479    if (rv == STOP)
 480       fprintf(stderr, _("invalid POP3 STAT response: %s\n"), _pop3_buf);
 481 jleave:
 482    NYD_LEAVE;
 483    return rv;
 484 }
 485
 486 static enum okay
 487 pop3_list(struct mailbox *mp, int n, size_t *size)
 488 {
 489    char o[LINESIZE], *cp;
 490    enum okay rv;
 491    NYD_ENTER;
 492
 493    snprintf(o, sizeof o, "LIST %u" NL, n);
 494    POP3_OUT(rv, o, MB_COMD, goto jleave);
 495    POP3_ANSWER(rv, goto jleave);
 496
 497    for (cp = _pop3_buf; *cp != '\0' && !spacechar(*cp); ++cp)
 498       ;
 499    while (*cp != '\0' && spacechar(*cp))
 500       ++cp;
 501    while (*cp != '\0' && !spacechar(*cp))
 502       ++cp;
 503    while (*cp != '\0' && spacechar(*cp))
 504       ++cp;
 505    if (*cp != '\0')
 506       *size = (size_t)strtol(cp, NULL, 10);
 507    else
 508       *size = 0;
 509 jleave:
 510    NYD_LEAVE;
 511    return rv;
 512 }
 513
 514 static void
 515 pop3_init(struct mailbox *mp, int n)
 516 {
 517    struct message *m;
 518    char *cp;
 519    NYD_ENTER;
 520
 521    m =  message + n;
 522    m->m_flag = MUSED | MNEW | MNOFROM | MNEWEST;
 523    m->m_block = 0;
 524    m->m_offset = 0;
 525    pop3_list(mp, PTR2SIZE(m - message + 1), &m->m_xsize);
 526
 527    if ((cp = hfield1("status", m)) != NULL) {
 528       while (*cp != '\0') {
 529          if (*cp == 'R')
 530             m->m_flag |= MREAD;
 531          else if (*cp == 'O')
 532             m->m_flag &= ~MNEW;
 533          ++cp;
 534       }
 535    }
 536    NYD_LEAVE;
 537 }
 538
 539 static void
 540 pop3_dates(struct mailbox *mp)
 541 {
 542    size_t i;
 543    NYD_ENTER;
 544    UNUSED(mp);
 545
 546    for (i = 0; UICMP(z, i, <, msgCount); ++i)
 547       substdate(message + i);
 548    NYD_LEAVE;
 549 }
 550
 551 static void
 552 pop3_setptr(struct mailbox *mp)
 553 {
 554    size_t i;
 555    NYD_ENTER;
 556
 557    message = scalloc(msgCount + 1, sizeof *message);
 558    for (i = 0; UICMP(z, i, <, msgCount); ++i)
 559       pop3_init(mp, i);
 560
 561    setdot(message);
 562    message[msgCount].m_size = 0;
 563    message[msgCount].m_lines = 0;
 564    pop3_dates(mp);
 565    NYD_LEAVE;
 566 }
 567
 568 static enum okay
 569 pop3_get(struct mailbox *mp, struct message *m, enum needspec volatile need)
 570 {
 571    char o[LINESIZE], *line, *lp;
 572    sighandler_type volatile saveint, savepipe;
 573    size_t linesize, linelen, size;
 574    int number, lines;
 575    int volatile emptyline;
 576    off_t offset;
 577    enum okay volatile rv;
 578    NYD_ENTER;
 579
 580    line = NULL; /* TODO line pool */
 581    saveint = savepipe = SIG_IGN;
 582    linesize = 0;
 583    number = (int)PTR2SIZE(m - message + 1);
 584    emptyline = 0;
 585    rv = STOP;
 586
 587    if (mp->mb_sock.s_fd < 0) {
 588       fprintf(stderr, _("POP3 connection already closed.\n"));
 589       ++_pop3_lock;
 590       goto jleave;
 591    }
 592
 593    if (_pop3_lock++ == 0) {
 594       if ((saveint = safe_signal(SIGINT, SIG_IGN)) != SIG_IGN)
 595          safe_signal(SIGINT, &_pop3_maincatch);
 596       savepipe = safe_signal(SIGPIPE, SIG_IGN);
 597       if (sigsetjmp(_pop3_jmp, 1)) {
 598          safe_signal(SIGINT, saveint);
 599          safe_signal(SIGPIPE, savepipe);
 600          --_pop3_lock;
 601          goto jleave;
 602       }
 603       if (savepipe != SIG_IGN)
 604          safe_signal(SIGPIPE, pop3catch);
 605    }
 606
 607    fseek(mp->mb_otf, 0L, SEEK_END);
 608    offset = ftell(mp->mb_otf);
 609 jretry:
 610    switch (need) {
 611    case NEED_HEADER:
 612       snprintf(o, sizeof o, "TOP %u 0" NL, number);
 613       break;
 614    case NEED_BODY:
 615       snprintf(o, sizeof o, "RETR %u" NL, number);
 616       break;
 617    case NEED_UNSPEC:
 618       abort(); /* XXX */
 619    }
 620    POP3_OUT(rv, o, MB_COMD | MB_MULT, goto jleave);
 621
 622    if (pop3_answer(mp) == STOP) {
 623       if (need == NEED_HEADER) {
 624          /* The TOP POP3 command is optional, so retry with entire message */
 625          need = NEED_BODY;
 626          goto jretry;
 627       }
 628       goto jleave;
 629    }
 630
 631    size = 0;
 632    lines = 0;
 633    while (sgetline(&line, &linesize, &linelen, &mp->mb_sock) > 0) {
 634       if (line[0] == '.' && line[1] == NL[0] && line[2] == NL[1] &&
 635             line[3] == '\0') {
 636          mp->mb_active &= ~MB_MULT;
 637          break;
 638       }
 639       if (line[0] == '.') {
 640          lp = line + 1;
 641          --linelen;
 642       } else
 643          lp = line;
 644       /* TODO >>
 645        * Need to mask 'From ' lines. This cannot be done properly
 646        * since some servers pass them as 'From ' and others as
 647        * '>From '. Although one could identify the first kind of
 648        * server in principle, it is not possible to identify the
 649        * second as '>From ' may also come from a server of the
 650        * first type as actual data. So do what is absolutely
 651        * necessary only - mask 'From '.
 652        *
 653        * If the line is the first line of the message header, it
 654        * is likely a real 'From ' line. In this case, it is just
 655        * ignored since it violates all standards.
 656        * TODO i have *never* seen the latter?!?!?
 657        * TODO <<
 658        */
 659       /* Since we simply copy over data without doing any transfer
 660        * encoding reclassification/adjustment we *have* to perform
 661        * RFC 4155 compliant From_ quoting here */
 662       if (is_head(lp, linelen)) {
 663          DBG( fprintf(stderr, "!! POP3 really needs to quote From?\n"); )
 664          if (lines == 0)
 665             continue;
 666          fputc('>', mp->mb_otf);
 667          ++size;
 668       }
 669       lines++;
 670       if (lp[linelen-1] == NL[1] && (linelen == 1 || lp[linelen-2] == NL[0])) {
 671          emptyline = linelen <= 2;
 672          if (linelen > 2)
 673             fwrite(lp, 1, linelen - 2, mp->mb_otf);
 674          fputc('\n', mp->mb_otf);
 675          size += linelen - 1;
 676       } else {
 677          emptyline = 0;
 678          fwrite(lp, 1, linelen, mp->mb_otf);
 679          size += linelen;
 680       }
 681    }
 682    if (!emptyline) {
 683       /* This is very ugly; but some POP3 daemons don't end a
 684        * message with NL NL, and we need \n\n for mbox format */
 685       fputc('\n', mp->mb_otf);
 686       ++lines;
 687       ++size;
 688    }
 689    m->m_size = size;
 690    m->m_lines = lines;
 691    m->m_block = mailx_blockof(offset);
 692    m->m_offset = mailx_offsetof(offset);
 693    fflush(mp->mb_otf);
 694
 695    switch (need) {
 696    case NEED_HEADER:
 697       m->m_have |= HAVE_HEADER;
 698       break;
 699    case NEED_BODY:
 700       m->m_have |= HAVE_HEADER | HAVE_BODY;
 701       m->m_xlines = m->m_lines;
 702       m->m_xsize = m->m_size;
 703       break;
 704    case NEED_UNSPEC:
 705       break;
 706    }
 707
 708    rv = OKAY;
 709 jleave:
 710    if (line != NULL)
 711       free(line);
 712    if (saveint != SIG_IGN)
 713       safe_signal(SIGINT, saveint);
 714    if (savepipe != SIG_IGN)
 715       safe_signal(SIGPIPE, savepipe);
 716    --_pop3_lock;
 717    NYD_LEAVE;
 718    if (interrupts)
 719       onintr(0);
 720    return rv;
 721 }
 722
 723 static enum okay
 724 pop3_exit(struct mailbox *mp)
 725 {
 726    enum okay rv;
 727    NYD_ENTER;
 728
 729    POP3_OUT(rv, "QUIT" NL, MB_COMD, goto jleave);
 730    POP3_ANSWER(rv, goto jleave);
 731 jleave:
 732    NYD_LEAVE;
 733    return rv;
 734 }
 735
 736 static enum okay
 737 pop3_delete(struct mailbox *mp, int n)
 738 {
 739    char o[LINESIZE];
 740    enum okay rv;
 741    NYD_ENTER;
 742
 743    snprintf(o, sizeof o, "DELE %u" NL, n);
 744    POP3_OUT(rv, o, MB_COMD, goto jleave);
 745    POP3_ANSWER(rv, goto jleave);
 746 jleave:
 747    NYD_LEAVE;
 748    return rv;
 749 }
 750
 751 static enum okay
 752 pop3_update(struct mailbox *mp)
 753 {
 754    struct message *m;
 755    int dodel, c, gotcha, held;
 756    NYD_ENTER;
 757
 758    if (!edit) {
 759       holdbits();
 760       c = 0;
 761       for (m = message; PTRCMP(m, <, message + msgCount); ++m)
 762          if (m->m_flag & MBOX)
 763             ++c;
 764       if (c > 0)
 765          makembox();
 766    }
 767
 768    gotcha = held = 0;
 769    for (m = message; PTRCMP(m, <, message + msgCount); ++m) {
 770       if (edit)
 771          dodel = m->m_flag & MDELETED;
 772       else
 773          dodel = !((m->m_flag & MPRESERVE) || !(m->m_flag & MTOUCH));
 774       if (dodel) {
 775          pop3_delete(mp, PTR2SIZE(m - message + 1));
 776          ++gotcha;
 777       } else
 778          ++held;
 779    }
 780    if (gotcha && edit) {
 781       printf(_("\"%s\" "), displayname);
 782       printf((ok_blook(bsdcompat) || ok_blook(bsdmsgs))
 783          ? _("complete\n") : _("updated.\n"));
 784    } else if (held && !edit) {
 785       if (held == 1)
 786          printf(_("Held 1 message in %s\n"), displayname);
 787       else
 788          printf(_("Held %d messages in %s\n"), held, displayname);
 789    }
 790    fflush(stdout);
 791    NYD_LEAVE;
 792    return OKAY;
 793 }
 794
 795 FL enum okay
 796 pop3_noop(void)
 797 {
 798    sighandler_type volatile saveint, savepipe;
 799    enum okay rv = STOP;
 800    NYD_ENTER;
 801
 802    _pop3_lock = 1;
 803    if ((saveint = safe_signal(SIGINT, SIG_IGN)) != SIG_IGN)
 804       safe_signal(SIGINT, &_pop3_maincatch);
 805    savepipe = safe_signal(SIGPIPE, SIG_IGN);
 806    if (sigsetjmp(_pop3_jmp, 1) == 0) {
 807       if (savepipe != SIG_IGN)
 808          safe_signal(SIGPIPE, pop3catch);
 809       rv = pop3_noop1(&mb);
 810    }
 811    safe_signal(SIGINT, saveint);
 812    safe_signal(SIGPIPE, savepipe);
 813    _pop3_lock = 0;
 814    NYD_LEAVE;
 815    return rv;
 816 }
 817
 818 FL int
 819 pop3_setfile(char const *server, enum fedit_mode fm)
 820 {
 821    struct sockconn sc;
 822    sighandler_type saveint, savepipe;
 823    char const *cp;
 824    int volatile rv;
 825    NYD_ENTER;
 826
 827    rv = 1;
 828    if (fm & FEDIT_NEWMAIL)
 829       goto jleave;
 830    rv = -1;
 831
 832    if (!url_parse(&sc.sc_url, CPROTO_POP3, server))
 833       goto jleave;
 834    if (!ok_blook(v15_compat) &&
 835          (!sc.sc_url.url_had_user || sc.sc_url.url_pass.s != NULL)) {
 836       fprintf(stderr, "New-style URL used without *v15-compat* being set\n");
 837       goto jleave;
 838    }
 839
 840    if (!(ok_blook(v15_compat) ? ccred_lookup(&sc.sc_cred, &sc.sc_url)
 841          : ccred_lookup_old(&sc.sc_cred, CPROTO_POP3,
 842             (sc.sc_url.url_had_user ? sc.sc_url.url_eu_h_p.s
 843              : sc.sc_url.url_u_h_p.s))))
 844       goto jleave;
 845
 846    if (!sopen(&sc.sc_sock, &sc.sc_url))
 847       goto jleave;
 848
 849    rv = 1;
 850    quit();
 851
 852    edit = !(fm & FEDIT_SYSBOX);
 853    if (mb.mb_sock.s_fd >= 0)
 854       sclose(&mb.mb_sock);
 855    if (mb.mb_itf) {
 856       fclose(mb.mb_itf);
 857       mb.mb_itf = NULL;
 858    }
 859    if (mb.mb_otf) {
 860       fclose(mb.mb_otf);
 861       mb.mb_otf = NULL;
 862    }
 863
 864    initbox(sc.sc_url.url_p_u_h_p);
 865    mb.mb_type = MB_VOID;
 866    _pop3_lock = 1;
 867    mb.mb_sock = sc.sc_sock;
 868
 869    saveint = safe_signal(SIGINT, SIG_IGN);
 870    savepipe = safe_signal(SIGPIPE, SIG_IGN);
 871    if (sigsetjmp(_pop3_jmp, 1)) {
 872       sclose(&mb.mb_sock);
 873       safe_signal(SIGINT, saveint);
 874       safe_signal(SIGPIPE, savepipe);
 875       _pop3_lock = 0;
 876       goto jleave;
 877    }
 878    if (saveint != SIG_IGN)
 879       safe_signal(SIGINT, pop3catch);
 880    if (savepipe != SIG_IGN)
 881       safe_signal(SIGPIPE, pop3catch);
 882
 883    if ((cp = ok_vlook(pop3_keepalive)) != NULL) {
 884       if ((_pop3_keepalive = (int)strtol(cp, NULL, 10)) > 0) {
 885          _pop3_savealrm = safe_signal(SIGALRM, pop3alarm);
 886          alarm(_pop3_keepalive);
 887       }
 888    }
 889
 890    mb.mb_sock.s_desc = sc.sc_url.url_proto;
 891    mb.mb_sock.s_onclose = pop3_timer_off;
 892    if (_pop3_login(&mb, &sc) != OKAY ||
 893          pop3_stat(&mb, &mailsize, &msgCount) != OKAY) {
 894       sclose(&mb.mb_sock);
 895       pop3_timer_off();
 896       safe_signal(SIGINT, saveint);
 897       safe_signal(SIGPIPE, savepipe);
 898       _pop3_lock = 0;
 899       goto jleave;
 900    }
 901    mb.mb_type = MB_POP3;
 902    mb.mb_perm = ((options & OPT_R_FLAG) || (fm & FEDIT_RDONLY)) ? 0 : MB_DELE;
 903    pop3_setptr(&mb);
 904    setmsize(msgCount);
 905    sawcom = FAL0;
 906
 907    safe_signal(SIGINT, saveint);
 908    safe_signal(SIGPIPE, savepipe);
 909    _pop3_lock = 0;
 910    if (!edit && msgCount == 0) {
 911       if (mb.mb_type == MB_POP3 && !ok_blook(emptystart))
 912          fprintf(stderr, _("No mail at %s\n"), server);
 913       goto jleave;
 914    }
 915
 916    rv = 0;
 917 jleave:
 918    NYD_LEAVE;
 919    return rv;
 920 }
 921
 922 FL enum okay
 923 pop3_header(struct message *m)
 924 {
 925    enum okay rv;
 926    NYD_ENTER;
 927
 928    rv = pop3_get(&mb, m, (ok_blook(pop3_bulk_load) ? NEED_BODY : NEED_HEADER));
 929    NYD_LEAVE;
 930    return rv;
 931 }
 932
 933 FL enum okay
 934 pop3_body(struct message *m)
 935 {
 936    enum okay rv;
 937    NYD_ENTER;
 938
 939    rv = pop3_get(&mb, m, NEED_BODY);
 940    NYD_LEAVE;
 941    return rv;
 942 }
 943
 944 FL void
 945 pop3_quit(void)
 946 {
 947    sighandler_type volatile saveint, savepipe;
 948    NYD_ENTER;
 949
 950    if (mb.mb_sock.s_fd < 0) {
 951       fprintf(stderr, _("POP3 connection already closed.\n"));
 952       goto jleave;
 953    }
 954
 955    _pop3_lock = 1;
 956    saveint = safe_signal(SIGINT, SIG_IGN);
 957    savepipe = safe_signal(SIGPIPE, SIG_IGN);
 958    if (sigsetjmp(_pop3_jmp, 1)) {
 959       safe_signal(SIGINT, saveint);
 960       safe_signal(SIGPIPE, saveint);
 961       _pop3_lock = 0;
 962       goto jleave;
 963    }
 964    if (saveint != SIG_IGN)
 965       safe_signal(SIGINT, pop3catch);
 966    if (savepipe != SIG_IGN)
 967       safe_signal(SIGPIPE, pop3catch);
 968    pop3_update(&mb);
 969    pop3_exit(&mb);
 970    sclose(&mb.mb_sock);
 971    safe_signal(SIGINT, saveint);
 972    safe_signal(SIGPIPE, savepipe);
 973    _pop3_lock = 0;
 974 jleave:
 975    NYD_LEAVE;
 976 }
 977
 978 #undef LINE
 979 #undef NL
 980 #endif /* HAVE_POP3 */
 981
 982 /* s-it-mode */