pd.if.org Git - zpackage/blob - src/fetchurl.c

   1 #define _POSIX_C_SOURCE 200809L
   2
   3 #include <stdio.h>
   4 #include <sys/types.h>
   5 #include <sys/socket.h>
   6 #include <netinet/in.h>
   7 #include <netdb.h>
   8 #include <string.h>
   9 #include <strings.h>
  10 #include <stdlib.h>
  11 #include <unistd.h>
  12 #include <signal.h>
  13 #include <time.h>
  14 #include <sys/stat.h>
  15 #include <fcntl.h>
  16
  17 #include "tlse.h"
  18
  19 struct tls_uri {
  20         char *scheme;
  21         char *userinfo;
  22         char *host;
  23         char *port;
  24         char *path;
  25         char *query;
  26         char *fragment;
  27 };
  28 int tls_parse_uri(char *, struct tls_uri *);
  29 void tls_free_uri(struct tls_uri *);
  30
  31 int open_tcp_connection(char *host, int port);
  32
  33 /* if trustpolicy is 0, we just accept anything */
  34 int verify_trust(struct TLSContext *context, struct TLSCertificate **chain, int
  35                 len) {
  36         /* suppress unused */
  37         if (context || chain || len) {
  38                 return 0;
  39         }
  40
  41         return 0;
  42 }
  43
  44 static char hexchars[] = "0123456789abcdefABCDEF";
  45
  46 static void hex(char *dst, uint8_t *src, size_t len) {
  47         while (len--) {
  48                 dst[0] = hexchars[(src[0]>>4)&0xf];
  49                 dst[1] = hexchars[src[0]&0xf];
  50                 dst+=2;
  51                 src++;
  52         }
  53 }
  54
  55 #if 0
  56 static void hexbin(uint8_t *dst, unsigned char *src, size_t len) {
  57         size_t i;
  58         int x;
  59
  60         for (i=0; i<len; i+=2) {
  61                 sscanf((const char *)src+i, "%02x", &x);
  62                 dst[i/2] = x;
  63         }
  64 }
  65 #endif
  66
  67 char *my_getline(struct tls_buffer *b, int fd, size_t *size) {
  68         char *loc = 0;
  69         char buf[4096];
  70         ssize_t rv = 0;
  71
  72         while (b->error == 0) {
  73                 loc = memchr(b->buffer, '\n', b->len);
  74                 if (loc) {
  75                         *size = loc - b->buffer + 1;
  76                         return b->buffer;
  77                 } else {
  78                         rv = read(fd, buf, sizeof buf);
  79                         if (rv == -1) {
  80                                 return 0;
  81                         }
  82                         if (rv == 0) {
  83                                 break;
  84                         }
  85                         tls_buffer_append(b, buf, rv);
  86                 }
  87         }
  88         if (rv == 0) {
  89                 *size = b->len;
  90                 return b->buffer;
  91         }
  92         return 0;
  93 }
  94
  95 /*
  96  * We use a trust on first use policy.  The trust DB is a simple
  97  * file in /var/lib/zpm/known_hosts, or ~/.zpm/known_hosts, or ZPM_KNOWNHOSTS.
  98  * if -k is given, no verification is done
  99  */
 100 int verify_first(struct TLSContext *context, struct TLSCertificate **chain, int
 101                 certs) {
 102         int err;
 103         char *trustfile, *homedir = 0, *host, *fp;
 104         unsigned char certhash[65];
 105         int trustdb;
 106         struct tls_buffer tbuf;
 107
 108         char *line = 0;
 109         size_t len = 0;
 110
 111         if (certs == 0 || chain == 0) {
 112                 return 1;
 113         }
 114
 115         err = tls_certificate_is_valid(chain[0]);
 116         if (err) {
 117                 return err;
 118         }
 119
 120         if (context->sni) {
 121                 err = tls_certificate_valid_subject(chain[0], context->sni);
 122                 if (err) {
 123                         return err;
 124                 }
 125         }
 126
 127         hex(certhash, chain[0]->fp, 32);
 128         certhash[64] = 0;
 129
 130         trustfile = getenv("ZPM_KNOWNHOSTS");
 131         if (!trustfile) {
 132                 if (geteuid() == 0) {
 133                         trustfile = "/var/lib/zpm/known_hosts";
 134                 } else {
 135                         /* we could do this with a series of
 136                          * openat() calls instead of building
 137                          * up a string
 138                          */
 139                         trustfile = getenv("HOME");
 140                         if (!trustfile) {
 141                                 fprintf(stderr, "home = %s\n", trustfile);
 142                                 return 1;
 143                         }
 144                         len = snprintf(homedir, 0, "%s/.zpm/known_hosts", trustfile);
 145                         homedir = malloc(len+1);
 146                         if (!homedir) {
 147                                 return 1;
 148                         }
 149                         len = snprintf(homedir, len+1, "%s/.zpm/known_hosts", trustfile);
 150                         trustfile = homedir;
 151                 }
 152         }
 153         /* cert is valid on its face, so check against the trust db */
 154         trustdb = open(trustfile, O_RDWR|O_CREAT, 0600);
 155         if (trustdb == -1) {
 156                 fprintf(stderr, "cannot open trustdb %s: %s\n", trustfile, strerror(errno));
 157                 if (homedir) {
 158                         free(homedir);
 159                 }
 160                 return 1;
 161         }
 162
 163         if (homedir) {
 164                 free(homedir);
 165         }
 166
 167         len = 0;
 168         tls_buffer_init(&tbuf, 128);
 169         do {
 170                 char *off;
 171
 172                 tls_buffer_shift(&tbuf, len);
 173                 line = my_getline(&tbuf, trustdb, &len);
 174
 175                 if (!line || !len) {
 176                         break;
 177                 }
 178
 179                 fp = line;
 180                 while (isspace(*fp)) {
 181                         fp++;
 182                 }
 183                 if (*fp == '#') {
 184                         continue;
 185                 }
 186                 off = strchr(line, ':');
 187                 if (!off) {
 188                         continue;
 189                 }
 190                 host = off + 1;
 191                 *off = 0;
 192                 if (line[len-1] == '\n') {
 193                         line[len-1] = 0;
 194                 }
 195
 196                 if (strlen(fp) != 64) {
 197                         continue;
 198                 }
 199
 200                 if (len && line[len-1] == '\n') {
 201                         line[len-1] = 0;
 202                 }
 203
 204                 if (strcmp(context->sni, host) != 0) {
 205                         continue;
 206                 }
 207
 208                 int match = (memcmp(certhash, fp, 64) == 0);
 209
 210                 close(trustdb);
 211                 tls_buffer_free(&tbuf);
 212                 if (!match) {
 213                         fprintf(stderr, "host %s certificate changed\n", host);
 214                 }
 215                 return match ? no_error : bad_certificate;
 216         } while (!tbuf.error);
 217
 218         /* got here, so we should be at EOF, so add this host to trust db */
 219         lseek(trustdb, 0, SEEK_END);
 220
 221         /* re-use the buffer so we only do one write */
 222         /* ignore errors, the cert is fine, we just can't update
 223          * the trustdb if there's errors here
 224          */
 225         tbuf.len = 0;
 226         tls_buffer_append(&tbuf, certhash, 64);
 227         tls_buffer_append_byte(&tbuf, ':');
 228         tls_buffer_append(&tbuf, context->sni, strlen(context->sni));
 229         tls_buffer_append_byte(&tbuf, '\n');
 230         write(trustdb, tbuf.buffer, tbuf.len);
 231         close(trustdb);
 232         tls_buffer_free(&tbuf);
 233
 234         return no_error;
 235 }
 236
 237 int verify_roots(struct TLSContext *context, struct TLSCertificate **chain, int
 238                 len) {
 239         int i, err;
 240
 241         if (chain) {
 242                 for (i = 0; i < len; i++) {
 243                         struct TLSCertificate *certificate = chain[i];
 244                         err = tls_certificate_is_valid(certificate);
 245                         if (err) {
 246                                 return err;
 247                         }
 248                 }
 249         }
 250
 251         err = tls_certificate_chain_is_valid(chain, len);
 252         if (err) {
 253                 return err;
 254         }
 255
 256         if (len > 0 && context->sni) {
 257                 err = tls_certificate_valid_subject(chain[0], context->sni);
 258                 if (err) {
 259                         return err;
 260                 }
 261         }
 262
 263         /* Perform certificate validation against ROOT CA */
 264         err = tls_certificate_chain_is_valid_root(context, chain, len);
 265         if (err) {
 266                 return err;
 267         }
 268
 269         return no_error;
 270 }
 271
 272 struct io {
 273         struct tls_buffer response;
 274         struct TLSContext *tls;
 275         int socket;
 276         int status_code;
 277         time_t last_modified;
 278         time_t date;
 279         size_t content_length;
 280         char *redirect;
 281 };
 282
 283 int month(char *m) {
 284         char *months[] = {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul",
 285                 "Aug", "Sep", "Oct", "Nov", "Dec" };
 286         int i;
 287
 288         for (i=0; i < 12; i++) {
 289                 if (!strncasecmp(m, months[i], 3)) {
 290                         return i+1;
 291                 }
 292         }
 293         return 0;
 294 }
 295
 296 /* Wed, 06 Feb 2019 10:06:05 GMT */
 297 time_t parse_date(char *d) {
 298         struct tm tm = { 0 };
 299         int rv;
 300
 301         int h, m, s, dom, Y;
 302         char M[4];
 303         rv = sscanf(d, "%*[a-zA-Z,] %d %s %d %d:%d:%d", &dom, M, &Y, &h, &m, &s);
 304         if (rv == 6) {
 305                 tm.tm_year = Y - 1900;
 306                 tm.tm_hour = h;
 307                 tm.tm_min = m;
 308                 tm.tm_sec = s;
 309                 tm.tm_mon = month(M)-1;
 310                 tm.tm_mday = dom;
 311
 312                 return mktime(&tm);
 313         }
 314         return -1;
 315 }
 316
 317 char *find_header(struct io *io, char *header, size_t *len) {
 318         char *eoh, *soh;
 319         size_t hlen;
 320
 321         *len = 0;
 322
 323         hlen = strlen(header);
 324         eoh = strstr(io->response.buffer, "\r\n\r\n");
 325         if (!eoh) {
 326                 return 0;
 327         }
 328         soh = io->response.buffer;
 329         do {
 330                 soh = strstr(soh, "\r\n");
 331                 if (soh == eoh) {
 332                         break;
 333                 }
 334                 soh += 2;
 335                 if (!memcmp(soh, header, hlen)) {
 336                         break;
 337                 }
 338         } while (soh < eoh);
 339
 340         if (soh >= eoh) {
 341                 return 0;
 342         }
 343         eoh = strstr(soh, "\r\n");
 344         soh += hlen;
 345         while (soh < eoh && isspace(*soh)) {
 346                 soh++;
 347         }
 348         *len = (eoh - soh);
 349         return soh;
 350 }
 351
 352 void parse_header(struct io *io) {
 353         char *s = io->response.buffer;
 354         int code = 0;
 355         char *hval;
 356         size_t hlen;
 357
 358         while (!isspace(*s)) {
 359                 s++;
 360         }
 361         while (isspace(*s)) {
 362                 s++;
 363         }
 364         code = strtol(s, 0, 10);
 365         io->status_code = code;
 366
 367         hval = find_header(io, "Date:", &hlen);
 368         if (hval) {
 369                 hval[hlen] = 0;
 370                 io->date = parse_date(hval);
 371                 hval[hlen] = '\r';
 372         }
 373         hval = find_header(io, "Last-Modified:", &hlen);
 374         if (hval) {
 375                 hval[hlen] = 0;
 376                 io->last_modified = parse_date(hval);
 377                 hval[hlen] = '\r';
 378         }
 379
 380         hval = find_header(io, "Content-Length:", &hlen);
 381         if (hval) {
 382                 hval[hlen] = 0;
 383                 io->content_length = strtoul(hval, 0, 10);
 384                 hval[hlen] = '\r';
 385         }
 386
 387         switch (code) {
 388                 case 301:
 389                 case 302:
 390                 case 303:
 391                 case 307:
 392                         hval = find_header(io, "Location:", &hlen);
 393                         if (hval) {
 394                                 io->redirect = strndup(hval, hlen);
 395                         }
 396                         break;
 397                 default:
 398                         break;
 399         }
 400
 401 }
 402
 403 ssize_t fill_buffer(struct io *io) {
 404         unsigned char buffer[4096];
 405         ssize_t ret;
 406
 407         if (io->tls) {
 408                 ret = tls_read(io->tls, buffer, sizeof buffer);
 409         } else {
 410                 ret = read(io->socket, buffer, sizeof buffer);
 411         }
 412
 413         if (ret > 0) {
 414                 tls_buffer_append(&io->response, buffer, ret);
 415         }
 416
 417         return ret;
 418 }
 419
 420 #if 0
 421 char *nextline(struct io *io) {
 422         char *eol = 0;;
 423
 424         eol = memchr(io->response.buffer, '\n', io.response.size);
 425         while (eol == 0) {
 426                 fill_buffer(io);
 427                 eol = memchr(io->response.buffer, '\n', io.response.size);
 428         }
 429         if (eol) {
 430
 431 }
 432 #endif
 433
 434 void append_header(struct tls_buffer *buf, char *header, char *val) {
 435         tls_buffer_append(buf, header, strlen(header));
 436         tls_buffer_append(buf, ": ", 2);
 437         tls_buffer_append(buf, val, strlen(val));
 438         tls_buffer_append(buf, "\r\n", 2);
 439 }
 440
 441 void append_timeheader(struct tls_buffer *buf, char *header, time_t ts) {
 442         char timestr[80];
 443         struct tm *tm;
 444
 445         tm = gmtime(&ts);
 446
 447         strftime(timestr, sizeof timestr, "%a, %d %b %Y %H:%M:%S GMT", tm);
 448         append_header(buf, header, timestr);
 449 }
 450
 451 static void pdots(int len, int ch, unsigned long was, unsigned long now,
 452                 unsigned long total) {
 453         was = len * was / total;
 454         if (now > total) {
 455                 now = total;
 456         }
 457         now = len * now / total;
 458         while (was++ < now) {
 459                 putc(ch,stderr);
 460         }
 461 }
 462
 463 static void fake_header(struct io *io, int fd) {
 464         struct stat st;
 465         int code = 200, rv;
 466         char *message, codestr[5], length[32];
 467         struct tls_buffer *hdr = &io->response;
 468
 469         if (fd == -1) {
 470                 switch (errno) {
 471                         case EACCES: code = 403; break;
 472                         case ENOENT: code = 404; break;
 473                         default: code = 500; break;
 474                 }
 475         } else {
 476                 rv = fstat(fd, &st);
 477                 if (rv == -1) {
 478                         code = 500;
 479                 }
 480         }
 481
 482         if (io->last_modified >= st.st_mtime) {
 483                 code = 304;
 484         }
 485
 486         switch (code) {
 487                 case 200: message = "OK"; break;
 488                 case 304: message = "Not Modified"; break;
 489                 case 403: message = "Forbidden"; break;
 490                 case 404: message = "Not Found"; break;
 491                 case 500: message = "Internal Server Error"; break;
 492                 default: break;
 493         }
 494         sprintf(codestr, "%0.3d ", code);
 495         tls_buffer_append(hdr, "HTTP/1.1 ", 9);
 496         tls_buffer_append(hdr, codestr, 4);
 497         tls_buffer_append_str(hdr, message);
 498         tls_buffer_append(hdr, "\r\n", 2);
 499
 500         append_timeheader(hdr, "Date", time(NULL));
 501         append_header(hdr, "Server", "zpm-fetchurl/0.9");
 502         if (code < 400) {
 503                 append_timeheader(hdr, "Last-Modified", st.st_mtime);
 504                 sprintf(length, "%zu", st.st_size);
 505                 append_header(hdr, "Content-Length", length);
 506         }
 507
 508         append_header(hdr, "Connection", "close");
 509         append_header(hdr, "Content-Type", "application/octet-stream");
 510         tls_buffer_append(hdr, "\r\n", 2);
 511 }
 512
 513 char *pathlast(char *path) {
 514         char *last = 0;
 515         size_t len = 0;
 516
 517         if (path == 0) {
 518                 return 0;
 519         }
 520
 521         while (*path == '/') {
 522                 path++;
 523         }
 524
 525         do {
 526                 last = path;
 527                 len = 0;
 528                 while (*path && *path != '/') {
 529                         path++;
 530                         len++;
 531                 }
 532                 while (*path == '/') {
 533                         path++;
 534                 }
 535         } while (*path);
 536
 537         if (len == 0) {
 538                 return 0;
 539         }
 540
 541         return strndup(last, len);
 542 }
 543
 544 static time_t file_mtime(char *path) {
 545         struct stat st;
 546         int rv;
 547
 548         rv = stat(path, &st);
 549         if (rv == -1) {
 550                 if (errno == ENOENT) {
 551                         return 0;
 552                 }
 553                 perror("stat failed:");
 554                 return -1;
 555         }
 556
 557         return st.st_mtime;
 558 }
 559
 560 int main(int ac, char *av[]) {
 561         int sockfd, port = -1, rv;
 562         ssize_t ret;
 563         int option;
 564 #if 0
 565         char msg[] = "GET %s HTTP/1.1\r\nHost: %s:%i\r\nConnection: close\r\n\r\n";
 566         char msg2[] = "GET %s HTTP/1.1\r\nHost: %s:%i\r\nLast-Modified: %s\r\nConnection: close\r\n\r\n";
 567         char msg_buffer[1024];
 568 #endif
 569         char *req_file = 0;
 570         char *host = 0;
 571         struct tls_uri uri = { 0 };
 572         char *outfile = 0;
 573         int raw = 0, head = 0;
 574         int out = 1; /* output file descriptor */
 575         int use_tls = 0;
 576         struct io io = { {0}, 0, -1, 0, 0, 0, 0, 0 };
 577         struct TLSContext *clientssl = 0;
 578         int failsilent = 0;
 579         char *lmfile = 0;
 580         int progressbar = 0;
 581         struct tls_buffer request;
 582         char lmtime[80];
 583         char *eoh = 0;
 584         size_t total = 0;
 585         size_t header_len;
 586         char *url = 0;
 587         int redirs = 0, redirlimit = 50, printstatus = 0;
 588         int verifypolicy = 1, calcoutfile = 0, ifnewer = 0;
 589
 590         ltc_mp = tfm_desc;
 591
 592         while ((option = getopt(ac, av, "o:OrIfz:np#R:SkK")) != -1) {
 593                 switch (option) {
 594                         case 'o': outfile = optarg; break;
 595                         case 'O': calcoutfile = 1; break;
 596                         case 'S': printstatus = 1; head = 1; break;
 597                         case 'k': verifypolicy = 0; break;
 598                         case 'K': verifypolicy = 2; break;
 599                         case 'I': head = 1;
 600                         case 'r': raw = 1; break;
 601                         case 'f': failsilent = 1; break;
 602                         case 'z': lmfile = optarg; break;
 603                         case 'n': ifnewer = 1; break;
 604                         case 'R': redirlimit = strtol(optarg, 0, 10); break;
 605                         case 'p':
 606                         case '#': progressbar = 1; break;
 607                         default:
 608                                   exit(EXIT_FAILURE);
 609                                   break;
 610                 }
 611         }
 612
 613         if (ac < optind) {
 614                 fprintf(stderr, "Usage: %s uri\n", av[0]);
 615                 exit(EXIT_FAILURE);
 616         }
 617
 618         url = strdup(av[optind]);
 619         if (!url) {
 620                 exit(EXIT_FAILURE);
 621         }
 622
 623         io.last_modified = 0;
 624
 625         if (calcoutfile && !outfile) {
 626                 tls_parse_uri(url, &uri);
 627                 outfile = pathlast(uri.path);
 628                 /* outfile leaks memory here, so if this
 629                  * were turned into a library function,
 630                  * we'd need to track it
 631                  */
 632                 if (!outfile) {
 633                         fprintf(stderr, "unable to determine outfile\n");
 634                         exit(EXIT_FAILURE);
 635                 }
 636         }
 637
 638         if (ifnewer && outfile && !lmfile) {
 639                 lmfile = outfile;
 640         }
 641
 642         if (lmfile) {
 643                 struct tm *mtime;
 644                 time_t ts;
 645
 646                 ts = file_mtime(lmfile);
 647
 648                 if (ts == -1) {
 649                         exit(EXIT_FAILURE);
 650                 } else if (ts != 0) {
 651                         io.last_modified = ts;
 652                         mtime = gmtime(&ts);
 653                         strftime(lmtime, sizeof lmtime, "%a, %d %b %Y %H:%M:%S GMT", mtime);
 654                 } else {
 655                         lmfile = 0;
 656                 }
 657         }
 658
 659         signal(SIGPIPE, SIG_IGN);
 660
 661         tls_buffer_init(&io.response, 0);
 662         tls_buffer_init(&request, 128);
 663
 664         while (redirs++ <= redirlimit) {
 665                 tls_free_uri(&uri);
 666                 io.response.len = 0;
 667                 request.len = 0;
 668                 eoh = 0;
 669
 670                 tls_parse_uri(url, &uri);
 671                 host = uri.host;
 672                 port = atoi(uri.port);
 673                 req_file = uri.path;
 674
 675                 /* construct request */
 676                 if (head) {
 677                         tls_buffer_append(&request, "HEAD ", 5);
 678                 } else {
 679                         tls_buffer_append(&request, "GET ", 4);
 680                 }
 681                 tls_buffer_append(&request, uri.path, strlen(uri.path));
 682                 tls_buffer_append(&request, " HTTP/1.1\r\n", 11);
 683
 684                 append_header(&request, "Host", host);
 685                 append_header(&request, "Connection", "close");
 686                 if (lmfile) {
 687                         append_header(&request, "If-Modified-Since", lmtime);
 688                 }
 689                 tls_buffer_append(&request, "\r\n", 2);
 690
 691                 if (!strcmp(uri.scheme, "https")) {
 692                         use_tls = 1;
 693
 694                         clientssl = tls_create_context(TLS_CLIENT, TLS_V12);
 695
 696                         /* optionally, we can set a certificate validation
 697                          * callback function if set_verify is not called, and
 698                          * root ca is set, `tls_default_verify` will be used
 699                          * (does exactly what `verify` does in this example)
 700                          */
 701                         if (verifypolicy == 2) {
 702                                 char *cert_path = 0;
 703                                 cert_path = getenv("ZPM_CERTFILE");
 704                                 if (!cert_path) {
 705                                         cert_path = "/var/lib/zpm/roots.pem";
 706                                 }
 707                                 rv = tls_load_root_file(clientssl, cert_path);
 708                                 if (rv == -1) {
 709                                         fprintf(stderr, "Error loading root certs\n");
 710                                         return 1;
 711                                 }
 712                                 tls_set_verify(clientssl, verify_roots);
 713                         } else if (verifypolicy == 1) {
 714                                 tls_set_verify(clientssl, verify_first);
 715                         } else {
 716                                 tls_set_verify(clientssl, verify_trust);
 717                         }
 718
 719                         if (!clientssl) {
 720                                 fprintf(stderr, "Error initializing client context\n");
 721                                 return -1;
 722                         }
 723                         tls_sni_set(clientssl, uri.host);
 724                         clientssl->sync = 1;
 725                         io.tls = clientssl;
 726                         sockfd = open_tcp_connection(host, port);
 727                         if (sockfd < 0) {
 728                                 perror("can't open connection");
 729                                 exit(EXIT_FAILURE);
 730                         }
 731                         tls_set_fd(clientssl, sockfd);
 732                         if ((rv = tls_connect(clientssl)) != 1) {
 733                                 fprintf(stderr, "Handshake Error %i\n", rv);
 734                                 return 1;
 735                         }
 736                         ret = tls_write(clientssl, request.buffer, request.len);
 737                 } else if (!strcmp(uri.scheme, "http")) {
 738                         sockfd = open_tcp_connection(host, port);
 739                         if (sockfd < 0) {
 740                                 perror("can't open connection");
 741                                 exit(EXIT_FAILURE);
 742                         }
 743                         ret = write(sockfd, request.buffer, request.len);
 744                 } else if (!strcmp(uri.scheme, "file")) {
 745                         sockfd = open(uri.path, O_RDONLY);
 746                         fake_header(&io, sockfd);
 747                         ret = 0;
 748                 } else {
 749                         fprintf(stderr, "scheme %s unknown\n", uri.scheme);
 750                         exit(EXIT_FAILURE);
 751                 }
 752
 753                 if (ret == -1) {
 754                         fprintf(stderr, "unable to write http request: %s\n", strerror(errno));
 755                         exit(EXIT_FAILURE);
 756                 }
 757
 758                 io.socket = sockfd;
 759
 760                 do {
 761                         if (io.response.len >= 4) {
 762                                 eoh = strstr(io.response.buffer, "\r\n\r\n");
 763                         }
 764                         if (!eoh) {
 765                                 ret = fill_buffer(&io);
 766                                 if (ret <= 0) {
 767                                         break;
 768                                 }
 769                         }
 770                 } while (!eoh);
 771
 772                 if (!eoh) {
 773                         /* never got (complet) header */
 774                         fprintf(stderr, "incomplete response to %s\n", av[optind]);
 775                         exit(EXIT_FAILURE);
 776                 }
 777
 778                 header_len = (size_t)(eoh - io.response.buffer) + 4;
 779                 parse_header(&io);
 780
 781                 switch (io.status_code) {
 782                         case 304:
 783                                 progressbar = 0;
 784                                 break;
 785                         case 301:
 786                         case 302:
 787                         case 303:
 788                         case 307:
 789                                 free(url);
 790                                 url = strdup(io.redirect);
 791                                 close(io.socket);
 792                                 continue;
 793                                 break;
 794                 }
 795
 796                 if (printstatus) {
 797                         printf("%d\n", io.status_code);
 798                         break;
 799                 }
 800
 801                 if (!raw) {
 802                         tls_buffer_shift(&io.response, header_len);
 803                 }
 804                 if (head) {
 805                         io.response.len -= 2;
 806                 }
 807
 808                 if (progressbar) {
 809                         if (io.content_length) {
 810                                 fprintf(stderr, "(%lu) ", io.content_length);
 811                         }
 812                 }
 813
 814                 if (outfile) {
 815                         out = open(outfile, O_WRONLY|O_CREAT, 0600);
 816                         if (out == -1) {
 817                                 perror("can't open output file:");
 818                                 exit(EXIT_FAILURE);
 819                         }
 820                 }
 821
 822                 do {
 823                         write(out, io.response.buffer, io.response.len);
 824                         ret = io.response.len;
 825                         io.response.len = 0;
 826
 827                         if (progressbar) {
 828                                 if (io.content_length) {
 829                                         pdots(50, '.', total, total+ret,
 830                                                         io.content_length);
 831                                 } else {
 832                                         putc('\r', stderr);
 833                                         fprintf(stderr, "%zu", total+ret);
 834                                 }
 835                                 total += ret;
 836                         }
 837                         if (head) {
 838                                 break;
 839                         }
 840                         ret = fill_buffer(&io);
 841                 } while (ret > 0);
 842
 843                 if (ret < 0) {
 844                         fprintf(stderr, "%s read error %zd\n", uri.scheme, ret);
 845                 }
 846                 struct timespec ts[2];
 847                 ts[0].tv_sec = 0; ts[0].tv_nsec = UTIME_OMIT;
 848                 ts[1].tv_sec = io.last_modified;
 849                 ts[1].tv_nsec = 0;
 850
 851                 futimens(out, ts);
 852                 close(out);
 853                 tls_buffer_free(&io.response);
 854                 break;
 855         }
 856
 857         if (use_tls) {
 858                 tls_shutdown(clientssl);
 859                 tls_free(clientssl);
 860         }
 861
 862         close(sockfd);
 863         if (progressbar && io.status_code == 200) {
 864                 fprintf(stderr, "(%lu)", total);
 865                 putc('\n',stderr);
 866         }
 867
 868         return io.status_code < 400 ? 0 : EXIT_FAILURE;
 869 }