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