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 - 2016 Steffen (Daode) Nurpmeso <steffen@sdaoden.eu>.
   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*)n_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(n_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    case SIGPIPE:
 363       n_err_sighdl(_("Received SIGPIPE during POP3 operation\n"));
 364       break;
 365    }
 366 }
 367
 368 static void
 369 _pop3_maincatch(int s)
 370 {
 371    NYD_X; /* Signal handler */
 372    n_UNUSED(s);
 373    if (interrupts == 0)
 374       n_err_sighdl(_("\n(Interrupt -- one more to abort operation)\n"));
 375    else {
 376       interrupts = 1;
 377       siglongjmp(_pop3_jmp, 1);
 378    }
 379 }
 380
 381 static enum okay
 382 pop3_noop1(struct mailbox *mp)
 383 {
 384    enum okay rv;
 385    NYD_ENTER;
 386
 387    POP3_OUT(rv, "NOOP" NETNL, MB_COMD, goto jleave);
 388    POP3_ANSWER(rv, goto jleave);
 389 jleave:
 390    NYD_LEAVE;
 391    return rv;
 392 }
 393
 394 static void
 395 pop3alarm(int s)
 396 {
 397    sighandler_type volatile saveint, savepipe;
 398    NYD_X; /* Signal handler */
 399    n_UNUSED(s);
 400
 401    if (_pop3_lock++ == 0) {
 402       hold_all_sigs();
 403       if ((saveint = safe_signal(SIGINT, SIG_IGN)) != SIG_IGN)
 404          safe_signal(SIGINT, &_pop3_maincatch);
 405       savepipe = safe_signal(SIGPIPE, SIG_IGN);
 406       if (sigsetjmp(_pop3_jmp, 1)) {
 407          interrupts = 0;
 408          safe_signal(SIGINT, saveint);
 409          safe_signal(SIGPIPE, savepipe);
 410          goto jbrk;
 411       }
 412       if (savepipe != SIG_IGN)
 413          safe_signal(SIGPIPE, pop3catch);
 414       rele_all_sigs();
 415       if (pop3_noop1(&mb) != OKAY) {
 416          safe_signal(SIGINT, saveint);
 417          safe_signal(SIGPIPE, savepipe);
 418          goto jleave;
 419       }
 420       safe_signal(SIGINT, saveint);
 421       safe_signal(SIGPIPE, savepipe);
 422    }
 423 jbrk:
 424    alarm(_pop3_keepalive);
 425 jleave:
 426    --_pop3_lock;
 427 }
 428
 429 static enum okay
 430 pop3_stat(struct mailbox *mp, off_t *size, int *cnt)
 431 {
 432    char *cp;
 433    enum okay rv;
 434    NYD_ENTER;
 435
 436    POP3_OUT(rv, "STAT" NETNL, MB_COMD, goto jleave);
 437    POP3_ANSWER(rv, goto jleave);
 438
 439    for (cp = _pop3_buf; *cp != '\0' && !spacechar(*cp); ++cp)
 440       ;
 441    while (*cp != '\0' && spacechar(*cp))
 442       ++cp;
 443
 444    if (*cp != '\0') {
 445       *cnt = (int)strtol(cp, NULL, 10);
 446       while (*cp != '\0' && !spacechar(*cp))
 447          ++cp;
 448       while (*cp != '\0' && spacechar(*cp))
 449          ++cp;
 450       if (*cp != '\0')
 451          *size = (int)strtol(cp, NULL, 10);
 452       else
 453          rv = STOP;
 454    } else
 455       rv = STOP;
 456
 457    if (rv == STOP)
 458       n_err(_("Invalid POP3 STAT response: %s\n"), _pop3_buf);
 459 jleave:
 460    NYD_LEAVE;
 461    return rv;
 462 }
 463
 464 static enum okay
 465 pop3_list(struct mailbox *mp, int n, size_t *size)
 466 {
 467    char o[LINESIZE], *cp;
 468    enum okay rv;
 469    NYD_ENTER;
 470
 471    snprintf(o, sizeof o, "LIST %u" NETNL, n);
 472    POP3_OUT(rv, o, MB_COMD, goto jleave);
 473    POP3_ANSWER(rv, goto jleave);
 474
 475    for (cp = _pop3_buf; *cp != '\0' && !spacechar(*cp); ++cp)
 476       ;
 477    while (*cp != '\0' && spacechar(*cp))
 478       ++cp;
 479    while (*cp != '\0' && !spacechar(*cp))
 480       ++cp;
 481    while (*cp != '\0' && spacechar(*cp))
 482       ++cp;
 483    if (*cp != '\0')
 484       *size = (size_t)strtol(cp, NULL, 10);
 485 jleave:
 486    NYD_LEAVE;
 487    return rv;
 488 }
 489
 490 static void
 491 pop3_setptr(struct mailbox *mp, struct sockconn const *scp)
 492 {
 493    size_t i;
 494    enum needspec ns;
 495    NYD_ENTER;
 496
 497    message = scalloc(msgCount + 1, sizeof *message);
 498    message[msgCount].m_size = 0;
 499    message[msgCount].m_lines = 0;
 500    dot = message; /* (Just do it: avoid crash -- shall i now do ointr(0).. */
 501
 502    for (i = 0; UICMP(z, i, <, msgCount); ++i) {
 503       struct message *m = message + i;
 504       m->m_flag = MUSED | MNEW | MNOFROM | MNEWEST;
 505       m->m_block = 0;
 506       m->m_offset = 0;
 507       m->m_size = m->m_xsize = 0;
 508    }
 509
 510    for (i = 0; UICMP(z, i, <, msgCount); ++i)
 511       if (!pop3_list(mp, i + 1, &message[i].m_xsize))
 512          goto jleave;
 513
 514    /* Force the load of all messages right now */
 515    ns = xok_blook(pop3_bulk_load, &scp->sc_url, OXM_ALL)
 516          ? NEED_BODY : NEED_HEADER;
 517    for (i = 0; UICMP(z, i, <, msgCount); ++i)
 518       if (!pop3_get(mp, message + i, ns))
 519          goto jleave;
 520
 521    srelax_hold();
 522    for (i = 0; UICMP(z, i, <, msgCount); ++i) {
 523       struct message *m = message + i;
 524       char const *cp;
 525
 526       if ((cp = hfield1("status", m)) != NULL)
 527          while (*cp != '\0') {
 528             if (*cp == 'R')
 529                m->m_flag |= MREAD;
 530             else if (*cp == 'O')
 531                m->m_flag &= ~MNEW;
 532             ++cp;
 533          }
 534
 535       substdate(m);
 536       srelax();
 537    }
 538    srelax_rele();
 539
 540    setdot(message);
 541 jleave:
 542    NYD_LEAVE;
 543 }
 544
 545 static enum okay
 546 pop3_get(struct mailbox *mp, struct message *m, enum needspec volatile need)
 547 {
 548    char o[LINESIZE], *line, *lp;
 549    sighandler_type volatile saveint, savepipe;
 550    size_t linesize, linelen, size;
 551    int number, lines;
 552    int volatile emptyline;
 553    off_t offset;
 554    enum okay volatile rv;
 555    NYD_ENTER;
 556
 557    line = NULL; /* TODO line pool */
 558    saveint = savepipe = SIG_IGN;
 559    linesize = 0;
 560    number = (int)PTR2SIZE(m - message + 1);
 561    emptyline = 0;
 562    rv = STOP;
 563
 564    if (mp->mb_sock.s_fd < 0) {
 565       n_err(_("POP3 connection already closed\n"));
 566       ++_pop3_lock;
 567       goto jleave;
 568    }
 569
 570    if (_pop3_lock++ == 0) {
 571       hold_all_sigs();
 572       if ((saveint = safe_signal(SIGINT, SIG_IGN)) != SIG_IGN)
 573          safe_signal(SIGINT, &_pop3_maincatch);
 574       savepipe = safe_signal(SIGPIPE, SIG_IGN);
 575       if (sigsetjmp(_pop3_jmp, 1))
 576          goto jleave;
 577       if (savepipe != SIG_IGN)
 578          safe_signal(SIGPIPE, pop3catch);
 579       rele_all_sigs();
 580    }
 581
 582    fseek(mp->mb_otf, 0L, SEEK_END);
 583    offset = ftell(mp->mb_otf);
 584 jretry:
 585    switch (need) {
 586    case NEED_HEADER:
 587       snprintf(o, sizeof o, "TOP %u 0" NETNL, number);
 588       break;
 589    case NEED_BODY:
 590       snprintf(o, sizeof o, "RETR %u" NETNL, number);
 591       break;
 592    case NEED_UNSPEC:
 593       abort(); /* XXX */
 594    }
 595    POP3_OUT(rv, o, MB_COMD | MB_MULT, goto jleave);
 596
 597    if (pop3_answer(mp) == STOP) {
 598       if (need == NEED_HEADER) {
 599          /* The TOP POP3 command is optional, so retry with entire message */
 600          need = NEED_BODY;
 601          goto jretry;
 602       }
 603       goto jleave;
 604    }
 605
 606    size = 0;
 607    lines = 0;
 608    while (sgetline(&line, &linesize, &linelen, &mp->mb_sock) > 0) {
 609       if (line[0] == '.' && line[1] == NETNL[0] && line[2] == NETNL[1] &&
 610             line[3] == '\0') {
 611          mp->mb_active &= ~MB_MULT;
 612          break;
 613       }
 614       if (line[0] == '.') {
 615          lp = line + 1;
 616          --linelen;
 617       } else
 618          lp = line;
 619       /* TODO >>
 620        * Need to mask 'From ' lines. This cannot be done properly
 621        * since some servers pass them as 'From ' and others as
 622        * '>From '. Although one could identify the first kind of
 623        * server in principle, it is not possible to identify the
 624        * second as '>From ' may also come from a server of the
 625        * first type as actual data. So do what is absolutely
 626        * necessary only - mask 'From '.
 627        *
 628        * If the line is the first line of the message header, it
 629        * is likely a real 'From ' line. In this case, it is just
 630        * ignored since it violates all standards.
 631        * TODO i have *never* seen the latter?!?!?
 632        * TODO <<
 633        */
 634       /* Since we simply copy over data without doing any transfer
 635        * encoding reclassification/adjustment we *have* to perform
 636        * RFC 4155 compliant From_ quoting here */
 637       if (emptyline && is_head(lp, linelen, FAL0)) {
 638          putc('>', mp->mb_otf);
 639          ++size;
 640       }
 641       lines++;
 642       if (lp[linelen-1] == NETNL[1] &&
 643             (linelen == 1 || lp[linelen-2] == NETNL[0])) {
 644          emptyline = linelen <= 2;
 645          if (linelen > 2)
 646             fwrite(lp, 1, linelen - 2, mp->mb_otf);
 647          putc('\n', mp->mb_otf);
 648          size += linelen - 1;
 649       } else {
 650          emptyline = 0;
 651          fwrite(lp, 1, linelen, mp->mb_otf);
 652          size += linelen;
 653       }
 654    }
 655    if (!emptyline) {
 656       /* This is very ugly; but some POP3 daemons don't end a
 657        * message with NETNL NETNL, and we need \n\n for mbox format */
 658       putc('\n', mp->mb_otf);
 659       ++lines;
 660       ++size;
 661    }
 662    m->m_size = size;
 663    m->m_lines = lines;
 664    m->m_block = mailx_blockof(offset);
 665    m->m_offset = mailx_offsetof(offset);
 666    fflush(mp->mb_otf);
 667
 668    switch (need) {
 669    case NEED_HEADER:
 670       m->m_content_info |= CI_HAVE_HEADER;
 671       break;
 672    case NEED_BODY:
 673       m->m_content_info |= CI_HAVE_HEADER | CI_HAVE_BODY;
 674       m->m_xlines = m->m_lines;
 675       m->m_xsize = m->m_size;
 676       break;
 677    case NEED_UNSPEC:
 678       break;
 679    }
 680
 681    rv = OKAY;
 682 jleave:
 683    if (line != NULL)
 684       free(line);
 685    if (saveint != SIG_IGN)
 686       safe_signal(SIGINT, saveint);
 687    if (savepipe != SIG_IGN)
 688       safe_signal(SIGPIPE, savepipe);
 689    --_pop3_lock;
 690    NYD_LEAVE;
 691    if (interrupts)
 692       n_raise(SIGINT);
 693    return rv;
 694 }
 695
 696 static enum okay
 697 pop3_exit(struct mailbox *mp)
 698 {
 699    enum okay rv;
 700    NYD_ENTER;
 701
 702    POP3_OUT(rv, "QUIT" NETNL, MB_COMD, goto jleave);
 703    POP3_ANSWER(rv, goto jleave);
 704 jleave:
 705    NYD_LEAVE;
 706    return rv;
 707 }
 708
 709 static enum okay
 710 pop3_delete(struct mailbox *mp, int n)
 711 {
 712    char o[LINESIZE];
 713    enum okay rv;
 714    NYD_ENTER;
 715
 716    snprintf(o, sizeof o, "DELE %u" NETNL, n);
 717    POP3_OUT(rv, o, MB_COMD, goto jleave);
 718    POP3_ANSWER(rv, goto jleave);
 719 jleave:
 720    NYD_LEAVE;
 721    return rv;
 722 }
 723
 724 static enum okay
 725 pop3_update(struct mailbox *mp)
 726 {
 727    struct message *m;
 728    int dodel, c, gotcha, held;
 729    NYD_ENTER;
 730
 731    if (!(pstate & PS_EDIT)) {
 732       holdbits();
 733       c = 0;
 734       for (m = message; PTRCMP(m, <, message + msgCount); ++m)
 735          if (m->m_flag & MBOX)
 736             ++c;
 737       if (c > 0)
 738          makembox();
 739    }
 740
 741    gotcha = held = 0;
 742    for (m = message; PTRCMP(m, <, message + msgCount); ++m) {
 743       if (pstate & PS_EDIT)
 744          dodel = m->m_flag & MDELETED;
 745       else
 746          dodel = !((m->m_flag & MPRESERVE) || !(m->m_flag & MTOUCH));
 747       if (dodel) {
 748          pop3_delete(mp, PTR2SIZE(m - message + 1));
 749          ++gotcha;
 750       } else
 751          ++held;
 752    }
 753
 754    /* C99 */{
 755       char const *dnq;
 756
 757       dnq = n_shexp_quote_cp(displayname, FAL0);
 758
 759       if (gotcha && (pstate & PS_EDIT)) {
 760          printf(_("%s "), dnq);
 761          printf((ok_blook(bsdcompat) || ok_blook(bsdmsgs))
 762             ? _("complete\n") : _("updated\n"));
 763       } else if (held && !(pstate & PS_EDIT)) {
 764          if (held == 1)
 765             printf(_("Held 1 message in %s\n"), dnq);
 766          else
 767             printf(_("Held %d messages in %s\n"), held, dnq);
 768       }
 769    }
 770    fflush(stdout);
 771    NYD_LEAVE;
 772    return OKAY;
 773 }
 774
 775 FL enum okay
 776 pop3_noop(void)
 777 {
 778    sighandler_type volatile saveint, savepipe;
 779    enum okay volatile rv = STOP;
 780    NYD_ENTER;
 781
 782    _pop3_lock = 1;
 783    hold_all_sigs();
 784    if ((saveint = safe_signal(SIGINT, SIG_IGN)) != SIG_IGN)
 785       safe_signal(SIGINT, &_pop3_maincatch);
 786    savepipe = safe_signal(SIGPIPE, SIG_IGN);
 787    if (sigsetjmp(_pop3_jmp, 1) == 0) {
 788       if (savepipe != SIG_IGN)
 789          safe_signal(SIGPIPE, pop3catch);
 790       rele_all_sigs();
 791       rv = pop3_noop1(&mb);
 792    }
 793    safe_signal(SIGINT, saveint);
 794    safe_signal(SIGPIPE, savepipe);
 795    _pop3_lock = 0;
 796    NYD_LEAVE;
 797    return rv;
 798 }
 799
 800 FL int
 801 pop3_setfile(char const *server, enum fedit_mode fm)
 802 {
 803    struct sockconn sc;
 804    sighandler_type saveint, savepipe;
 805    char const *cp;
 806    int volatile rv;
 807    NYD_ENTER;
 808
 809    rv = 1;
 810    if (fm & FEDIT_NEWMAIL)
 811       goto jleave;
 812    rv = -1;
 813
 814    if (!url_parse(&sc.sc_url, CPROTO_POP3, server))
 815       goto jleave;
 816    if (!ok_blook(v15_compat) &&
 817          (!sc.sc_url.url_had_user || sc.sc_url.url_pass.s != NULL)) {
 818       n_err(_("New-style URL used without *v15-compat* being set\n"));
 819       goto jleave;
 820    }
 821
 822    if (!(ok_blook(v15_compat) ? ccred_lookup(&sc.sc_cred, &sc.sc_url)
 823          : ccred_lookup_old(&sc.sc_cred, CPROTO_POP3,
 824             (sc.sc_url.url_had_user ? sc.sc_url.url_eu_h_p.s
 825              : sc.sc_url.url_u_h_p.s))))
 826       goto jleave;
 827
 828    if (!quit(FAL0))
 829       goto jleave;
 830
 831    if (!sopen(&sc.sc_sock, &sc.sc_url))
 832       goto jleave;
 833
 834    rv = 1;
 835
 836    if (fm & FEDIT_SYSBOX)
 837       pstate &= ~PS_EDIT;
 838    else
 839       pstate |= PS_EDIT;
 840    if (mb.mb_sock.s_fd >= 0)
 841       sclose(&mb.mb_sock);
 842    if (mb.mb_itf) {
 843       fclose(mb.mb_itf);
 844       mb.mb_itf = NULL;
 845    }
 846    if (mb.mb_otf) {
 847       fclose(mb.mb_otf);
 848       mb.mb_otf = NULL;
 849    }
 850
 851    initbox(sc.sc_url.url_p_u_h_p);
 852    mb.mb_type = MB_VOID;
 853    _pop3_lock = 1;
 854    mb.mb_sock = sc.sc_sock;
 855
 856    saveint = safe_signal(SIGINT, SIG_IGN);
 857    savepipe = safe_signal(SIGPIPE, SIG_IGN);
 858    if (sigsetjmp(_pop3_jmp, 1)) {
 859       sclose(&mb.mb_sock);
 860       n_err(_("POP3 connection closed\n"));
 861       safe_signal(SIGINT, saveint);
 862       safe_signal(SIGPIPE, savepipe);
 863       _pop3_lock = 0;
 864       rv = -1;
 865       if (interrupts > 0)
 866          n_raise(SIGINT);
 867       goto jleave;
 868    }
 869    if (saveint != SIG_IGN)
 870       safe_signal(SIGINT, pop3catch);
 871    if (savepipe != SIG_IGN)
 872       safe_signal(SIGPIPE, pop3catch);
 873
 874    if ((cp = xok_vlook(pop3_keepalive, &sc.sc_url, OXM_ALL)) != NULL) {
 875       if ((_pop3_keepalive = (int)strtol(cp, NULL, 10)) > 0) {
 876          _pop3_savealrm = safe_signal(SIGALRM, pop3alarm);
 877          alarm(_pop3_keepalive);
 878       }
 879    }
 880
 881    mb.mb_sock.s_desc = sc.sc_url.url_needs_tls ? "POP3S" : "POP3";
 882    mb.mb_sock.s_onclose = pop3_timer_off;
 883    if (_pop3_login(&mb, &sc) != OKAY ||
 884          pop3_stat(&mb, &mailsize, &msgCount) != OKAY) {
 885       sclose(&mb.mb_sock);
 886       pop3_timer_off();
 887       safe_signal(SIGINT, saveint);
 888       safe_signal(SIGPIPE, savepipe);
 889       _pop3_lock = 0;
 890       goto jleave;
 891    }
 892
 893    setmsize(msgCount);
 894    mb.mb_type = MB_POP3;
 895    mb.mb_perm = ((options & OPT_R_FLAG) || (fm & FEDIT_RDONLY)) ? 0 : MB_DELE;
 896    pop3_setptr(&mb, &sc);
 897
 898    /*if (!(fm & FEDIT_NEWMAIL)) */{
 899       pstate &= ~PS_SAW_COMMAND;
 900       pstate |= PS_SETFILE_OPENED;
 901    }
 902
 903    safe_signal(SIGINT, saveint);
 904    safe_signal(SIGPIPE, savepipe);
 905    _pop3_lock = 0;
 906
 907    if ((options & OPT_EXISTONLY) && !(options & OPT_HEADERLIST)) {
 908       rv = (msgCount == 0);
 909       goto jleave;
 910    }
 911
 912    if (!(pstate & PS_EDIT) && msgCount == 0) {
 913       if (!ok_blook(emptystart))
 914          n_err(_("No mail at %s\n"), server);
 915       goto jleave;
 916    }
 917
 918    rv = 0;
 919 jleave:
 920    NYD_LEAVE;
 921    return rv;
 922 }
 923
 924 FL enum okay
 925 pop3_header(struct message *m)
 926 {
 927    enum okay rv;
 928    NYD_ENTER;
 929
 930    /* TODO no URL here, no OXM possible; (however it is used in setfile()..) */
 931    rv = pop3_get(&mb, m, (ok_blook(pop3_bulk_load) ? NEED_BODY : NEED_HEADER));
 932    NYD_LEAVE;
 933    return rv;
 934 }
 935
 936 FL enum okay
 937 pop3_body(struct message *m)
 938 {
 939    enum okay rv;
 940    NYD_ENTER;
 941
 942    rv = pop3_get(&mb, m, NEED_BODY);
 943    NYD_LEAVE;
 944    return rv;
 945 }
 946
 947 FL bool_t
 948 pop3_quit(bool_t hold_sigs_on)
 949 {
 950    sighandler_type volatile saveint, savepipe;
 951    bool_t rv;
 952    NYD_ENTER;
 953
 954    if(hold_sigs_on)
 955       rele_sigs();
 956
 957    rv = FAL0;
 958
 959    if (mb.mb_sock.s_fd < 0) {
 960       n_err(_("POP3 connection already closed\n"));
 961       rv = TRU1;
 962       goto jleave;
 963    }
 964
 965    _pop3_lock = 1;
 966    saveint = safe_signal(SIGINT, SIG_IGN);
 967    savepipe = safe_signal(SIGPIPE, SIG_IGN);
 968    if (sigsetjmp(_pop3_jmp, 1)) {
 969       safe_signal(SIGINT, saveint);
 970       safe_signal(SIGPIPE, savepipe);
 971       _pop3_lock = 0;
 972       interrupts = 0;
 973       goto jleave;
 974    }
 975    if (saveint != SIG_IGN)
 976       safe_signal(SIGINT, pop3catch);
 977    if (savepipe != SIG_IGN)
 978       safe_signal(SIGPIPE, pop3catch);
 979    pop3_update(&mb);
 980    pop3_exit(&mb);
 981    sclose(&mb.mb_sock);
 982    safe_signal(SIGINT, saveint);
 983    safe_signal(SIGPIPE, savepipe);
 984    _pop3_lock = 0;
 985
 986    rv = TRU1;
 987 jleave:
 988    if(hold_sigs_on)
 989       hold_sigs();
 990    NYD_LEAVE;
 991    return rv;
 992 }
 993 #endif /* HAVE_POP3 */
 994
 995 /* s-it-mode */