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 *encoded_path;
  26         char *query;
  27         char *encoded_query;
  28         char *fragment;
  29 };
  30
  31 int tls_parse_uri(char *, struct tls_uri *);
  32 void tls_free_uri(struct tls_uri *);
  33
  34 int open_tcp_connection(char *host, int port);
  35
  36 /* if trustpolicy is 0, we just accept anything */
  37 int verify_trust(struct TLSContext *context, struct TLSCertificate **chain, int
  38                 len) {
  39         /* suppress unused */
  40         if (context || chain || len) {
  41                 return 0;
  42         }
  43
  44         return 0;
  45 }
  46
  47 static char hexchars[] = "0123456789abcdefABCDEF";
  48
  49 static void hex(char *dst, uint8_t *src, size_t len) {
  50         while (len--) {
  51                 dst[0] = hexchars[(src[0]>>4)&0xf];
  52                 dst[1] = hexchars[src[0]&0xf];
  53                 dst+=2;
  54                 src++;
  55         }
  56 }
  57
  58 #if 0
  59 static void hexbin(uint8_t *dst, unsigned char *src, size_t len) {
  60         size_t i;
  61         int x;
  62
  63         for (i=0; i<len; i+=2) {
  64                 sscanf((const char *)src+i, "%02x", &x);
  65                 dst[i/2] = x;
  66         }
  67 }
  68 #endif
  69
  70 char *my_getline(struct tls_buffer *b, int fd, size_t *size) {
  71         char *loc = 0;
  72         char buf[4096];
  73         ssize_t rv = 0;
  74
  75         while (b->error == 0) {
  76                 loc = memchr(b->buffer, '\n', b->len);
  77                 if (loc) {
  78                         *size = loc - b->buffer + 1;
  79                         return b->buffer;
  80                 } else {
  81                         rv = read(fd, buf, sizeof buf);
  82                         if (rv == -1) {
  83                                 return 0;
  84                         }
  85                         if (rv == 0) {
  86                                 break;
  87                         }
  88                         tls_buffer_append(b, buf, rv);
  89                 }
  90         }
  91         if (rv == 0) {
  92                 *size = b->len;
  93                 return b->buffer;
  94         }
  95         return 0;
  96 }
  97
  98 /*
  99  * We use a trust on first use policy.  The trust DB is a simple
 100  * file in /var/lib/zpm/known_hosts, or ~/.zpm/known_hosts, or ZPM_KNOWNHOSTS.
 101  * if -k is given, no verification is done
 102  */
 103 int verify_first(struct TLSContext *context, struct TLSCertificate **chain, int
 104                 certs) {
 105         int err;
 106         char *trustfile, *homedir = 0, *host, *fp;
 107         unsigned char certhash[65];
 108         int trustdb;
 109         struct tls_buffer tbuf;
 110
 111         char *line = 0;
 112         size_t len = 0;
 113
 114         if (certs == 0 || chain == 0) {
 115                 return 1;
 116         }
 117
 118         err = tls_certificate_is_valid(chain[0]);
 119         if (err) {
 120                 return err;
 121         }
 122
 123         if (context->sni) {
 124                 err = tls_certificate_valid_subject(chain[0], context->sni);
 125                 if (err) {
 126                         return err;
 127                 }
 128         }
 129
 130         hex(certhash, chain[0]->fp, 32);
 131         certhash[64] = 0;
 132
 133         trustfile = getenv("ZPM_KNOWNHOSTS");
 134         if (!trustfile) {
 135                 if (geteuid() == 0) {
 136                         trustfile = "/var/lib/zpm/known_hosts";
 137                 } else {
 138                         /* we could do this with a series of
 139                          * openat() calls instead of building
 140                          * up a string
 141                          */
 142                         trustfile = getenv("HOME");
 143                         if (!trustfile) {
 144                                 fprintf(stderr, "home = %s\n", trustfile);
 145                                 return 1;
 146                         }
 147                         len = snprintf(homedir, 0, "%s/.zpm/known_hosts", trustfile);
 148                         homedir = malloc(len+1);
 149                         if (!homedir) {
 150                                 return 1;
 151                         }
 152                         len = snprintf(homedir, len+1, "%s/.zpm/known_hosts", trustfile);
 153                         trustfile = homedir;
 154                 }
 155         }
 156         /* cert is valid on its face, so check against the trust db */
 157         trustdb = open(trustfile, O_RDWR|O_CREAT, 0600);
 158         if (trustdb == -1) {
 159                 fprintf(stderr, "cannot open trustdb %s: %s\n", trustfile, strerror(errno));
 160                 if (homedir) {
 161                         free(homedir);
 162                 }
 163                 return 1;
 164         }
 165
 166         if (homedir) {
 167                 free(homedir);
 168         }
 169
 170         len = 0;
 171         tls_buffer_init(&tbuf, 128);
 172         do {
 173                 char *off;
 174
 175                 tls_buffer_shift(&tbuf, len);
 176                 line = my_getline(&tbuf, trustdb, &len);
 177
 178                 if (!line || !len) {
 179                         break;
 180                 }
 181
 182                 fp = line;
 183                 while (isspace(*fp)) {
 184                         fp++;
 185                 }
 186                 if (*fp == '#') {
 187                         continue;
 188                 }
 189                 off = strchr(line, ':');
 190                 if (!off) {
 191                         continue;
 192                 }
 193                 host = off + 1;
 194                 *off = 0;
 195                 if (line[len-1] == '\n') {
 196                         line[len-1] = 0;
 197                 }
 198
 199                 if (strlen(fp) != 64) {
 200                         continue;
 201                 }
 202
 203                 if (len && line[len-1] == '\n') {
 204                         line[len-1] = 0;
 205                 }
 206
 207                 if (strcmp(context->sni, host) != 0) {
 208                         continue;
 209                 }
 210
 211                 int match = (memcmp(certhash, fp, 64) == 0);
 212                 if (!match) {
 213                         fprintf(stderr, "host %s certificate changed\n", host);
 214                         fprintf(stderr, "was %.64s\n", fp);
 215                         fprintf(stderr, "now %.64s\n", certhash);
 216                 }
 217
 218                 close(trustdb);
 219                 tls_buffer_free(&tbuf);
 220                 return match ? no_error : bad_certificate;
 221         } while (!tbuf.error);
 222
 223         /* got here, so we should be at EOF, so add this host to trust db */
 224         lseek(trustdb, 0, SEEK_END);
 225
 226         /* re-use the buffer so we only do one write */
 227         /* ignore errors, the cert is fine, we just can't update
 228          * the trustdb if there's errors here
 229          */
 230         tbuf.len = 0;
 231         tls_buffer_append(&tbuf, certhash, 64);
 232         tls_buffer_append_byte(&tbuf, ':');
 233         tls_buffer_append(&tbuf, context->sni, strlen(context->sni));
 234         tls_buffer_append_byte(&tbuf, '\n');
 235         write(trustdb, tbuf.buffer, tbuf.len);
 236         close(trustdb);
 237         tls_buffer_free(&tbuf);
 238
 239         return no_error;
 240 }
 241
 242 int verify_roots(struct TLSContext *context, struct TLSCertificate **chain, int
 243                 len) {
 244         int i, err;
 245
 246         if (chain) {
 247                 for (i = 0; i < len; i++) {
 248                         struct TLSCertificate *certificate = chain[i];
 249                         err = tls_certificate_is_valid(certificate);
 250                         if (err) {
 251                                 return err;
 252                         }
 253                 }
 254         }
 255
 256         err = tls_certificate_chain_is_valid(chain, len);
 257         if (err) {
 258                 return err;
 259         }
 260
 261         if (len > 0 && context->sni) {
 262                 err = tls_certificate_valid_subject(chain[0], context->sni);
 263                 if (err) {
 264                         return err;
 265                 }
 266         }
 267
 268         /* Perform certificate validation against ROOT CA */
 269         err = tls_certificate_chain_is_valid_root(context, chain, len);
 270         if (err) {
 271                 return err;
 272         }
 273
 274         return no_error;
 275 }
 276
 277 struct io {
 278         struct tls_buffer response;
 279         struct TLSContext *tls;
 280         int socket;
 281         int status_code;
 282         time_t last_modified;
 283         time_t date;
 284         size_t content_length;
 285         char *redirect;
 286 };
 287
 288 int month(char *m) {
 289         char *months[] = {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul",
 290                 "Aug", "Sep", "Oct", "Nov", "Dec" };
 291         int i;
 292
 293         for (i=0; i < 12; i++) {
 294                 if (!strncasecmp(m, months[i], 3)) {
 295                         return i+1;
 296                 }
 297         }
 298         return 0;
 299 }
 300
 301 /* Wed, 06 Feb 2019 10:06:05 GMT */
 302 time_t parse_date(char *d) {
 303         struct tm tm = { 0 };
 304         int rv;
 305
 306         int h, m, s, dom, Y;
 307         char M[4];
 308         rv = sscanf(d, "%*[a-zA-Z,] %d %s %d %d:%d:%d", &dom, M, &Y, &h, &m, &s);
 309         if (rv == 6) {
 310                 tm.tm_year = Y - 1900;
 311                 tm.tm_hour = h;
 312                 tm.tm_min = m;
 313                 tm.tm_sec = s;
 314                 tm.tm_mon = month(M)-1;
 315                 tm.tm_mday = dom;
 316
 317                 return mktime(&tm);
 318         }
 319         return -1;
 320 }
 321
 322 char *find_header(struct io *io, char *header, size_t *len) {
 323         char *eoh, *soh;
 324         size_t hlen;
 325
 326         *len = 0;
 327
 328         hlen = strlen(header);
 329         eoh = strstr(io->response.buffer, "\r\n\r\n");
 330         if (!eoh) {
 331                 return 0;
 332         }
 333         soh = io->response.buffer;
 334         do {
 335                 soh = strstr(soh, "\r\n");
 336                 if (soh == eoh) {
 337                         break;
 338                 }
 339                 soh += 2;
 340                 if (!memcmp(soh, header, hlen)) {
 341                         break;
 342                 }
 343         } while (soh < eoh);
 344
 345         if (soh >= eoh) {
 346                 return 0;
 347         }
 348         eoh = strstr(soh, "\r\n");
 349         soh += hlen;
 350         while (soh < eoh && isspace(*soh)) {
 351                 soh++;
 352         }
 353         *len = (eoh - soh);
 354         return soh;
 355 }
 356
 357 void parse_header(struct io *io) {
 358         char *s = io->response.buffer;
 359         int code = 0;
 360         char *hval;
 361         size_t hlen;
 362
 363         while (!isspace(*s)) {
 364                 s++;
 365         }
 366         while (isspace(*s)) {
 367                 s++;
 368         }
 369         code = strtol(s, 0, 10);
 370         io->status_code = code;
 371
 372         hval = find_header(io, "Date:", &hlen);
 373         if (hval) {
 374                 hval[hlen] = 0;
 375                 io->date = parse_date(hval);
 376                 hval[hlen] = '\r';
 377         }
 378         hval = find_header(io, "Last-Modified:", &hlen);
 379         if (hval) {
 380                 hval[hlen] = 0;
 381                 io->last_modified = parse_date(hval);
 382                 hval[hlen] = '\r';
 383         }
 384
 385         hval = find_header(io, "Content-Length:", &hlen);
 386         if (hval) {
 387                 hval[hlen] = 0;
 388                 io->content_length = strtoul(hval, 0, 10);
 389                 hval[hlen] = '\r';
 390         }
 391
 392         switch (code) {
 393                 case 301:
 394                 case 302:
 395                 case 303:
 396                 case 307:
 397                         hval = find_header(io, "Location:", &hlen);
 398                         if (hval) {
 399                                 io->redirect = strndup(hval, hlen);
 400                         }
 401                         break;
 402                 default:
 403                         break;
 404         }
 405
 406 }
 407
 408 ssize_t fill_buffer(struct io *io) {
 409         unsigned char buffer[4096];
 410         ssize_t ret;
 411
 412         if (io->tls) {
 413                 ret = tls_read(io->tls, buffer, sizeof buffer);
 414         } else {
 415                 ret = read(io->socket, buffer, sizeof buffer);
 416         }
 417
 418         if (ret > 0) {
 419                 tls_buffer_append(&io->response, buffer, ret);
 420         }
 421
 422         return ret;
 423 }
 424
 425 #if 0
 426 char *nextline(struct io *io) {
 427         char *eol = 0;;
 428
 429         eol = memchr(io->response.buffer, '\n', io.response.size);
 430         while (eol == 0) {
 431                 fill_buffer(io);
 432                 eol = memchr(io->response.buffer, '\n', io.response.size);
 433         }
 434         if (eol) {
 435
 436 }
 437 #endif
 438
 439 void append_header(struct tls_buffer *buf, char *header, char *val) {
 440         tls_buffer_append(buf, header, strlen(header));
 441         tls_buffer_append(buf, ": ", 2);
 442         tls_buffer_append(buf, val, strlen(val));
 443         tls_buffer_append(buf, "\r\n", 2);
 444 }
 445
 446 void append_timeheader(struct tls_buffer *buf, char *header, time_t ts) {
 447         char timestr[80];
 448         struct tm *tm;
 449
 450         tm = gmtime(&ts);
 451
 452         strftime(timestr, sizeof timestr, "%a, %d %b %Y %H:%M:%S GMT", tm);
 453         append_header(buf, header, timestr);
 454 }
 455
 456 static void pdots(int len, int ch, unsigned long was, unsigned long now,
 457                 unsigned long total) {
 458         was = len * was / total;
 459         if (now > total) {
 460                 now = total;
 461         }
 462         now = len * now / total;
 463         while (was++ < now) {
 464                 putc(ch,stderr);
 465         }
 466 }
 467
 468 static void fake_header(struct io *io, int fd) {
 469         struct stat st;
 470         int code = 200, rv;
 471         char *message, codestr[5], length[32];
 472         struct tls_buffer *hdr = &io->response;
 473
 474         if (fd == -1) {
 475                 switch (errno) {
 476                         case EACCES: code = 403; break;
 477                         case ENOENT: code = 404; break;
 478                         default: code = 500; break;
 479                 }
 480         } else {
 481                 rv = fstat(fd, &st);
 482                 if (rv == -1) {
 483                         code = 500;
 484                 }
 485         }
 486
 487         if (io->last_modified >= st.st_mtime) {
 488                 code = 304;
 489         }
 490
 491         switch (code) {
 492                 case 200: message = "OK"; break;
 493                 case 304: message = "Not Modified"; break;
 494                 case 403: message = "Forbidden"; break;
 495                 case 404: message = "Not Found"; break;
 496                 case 500: message = "Internal Server Error"; break;
 497                 default: break;
 498         }
 499         sprintf(codestr, "%0.3d ", code);
 500         tls_buffer_append(hdr, "HTTP/1.1 ", 9);
 501         tls_buffer_append(hdr, codestr, 4);
 502         tls_buffer_append_str(hdr, message);
 503         tls_buffer_append(hdr, "\r\n", 2);
 504
 505         append_timeheader(hdr, "Date", time(NULL));
 506         append_header(hdr, "Server", "zpm-fetchurl/0.9");
 507         if (code < 400) {
 508                 append_timeheader(hdr, "Last-Modified", st.st_mtime);
 509                 sprintf(length, "%zu", st.st_size);
 510                 append_header(hdr, "Content-Length", length);
 511         }
 512
 513         append_header(hdr, "Connection", "close");
 514         append_header(hdr, "Content-Type", "application/octet-stream");
 515         tls_buffer_append(hdr, "\r\n", 2);
 516 }
 517
 518 char *pathlast(char *path) {
 519         char *last = 0;
 520         size_t len = 0;
 521
 522         if (path == 0) {
 523                 return 0;
 524         }
 525
 526         while (*path == '/') {
 527                 path++;
 528         }
 529
 530         do {
 531                 last = path;
 532                 len = 0;
 533                 while (*path && *path != '/') {
 534                         path++;
 535                         len++;
 536                 }
 537                 while (*path == '/') {
 538                         path++;
 539                 }
 540         } while (*path);
 541
 542         if (len == 0) {
 543                 return 0;
 544         }
 545
 546         return strndup(last, len);
 547 }
 548
 549 static time_t file_mtime(char *path) {
 550         struct stat st;
 551         int rv;
 552
 553         rv = stat(path, &st);
 554         if (rv == -1) {
 555                 if (errno == ENOENT) {
 556                         return 0;
 557                 }
 558                 perror("stat failed:");
 559                 return -1;
 560         }
 561
 562         return st.st_mtime;
 563 }
 564
 565 int main(int ac, char *av[]) {
 566         int sockfd, port = -1, rv;
 567         ssize_t ret;
 568         int option;
 569 #if 0
 570         char msg[] = "GET %s HTTP/1.1\r\nHost: %s:%i\r\nConnection: close\r\n\r\n";
 571         char msg2[] = "GET %s HTTP/1.1\r\nHost: %s:%i\r\nLast-Modified: %s\r\nConnection: close\r\n\r\n";
 572         char msg_buffer[1024];
 573 #endif
 574         char *req_file = 0;
 575         char *host = 0;
 576         struct tls_uri uri = { 0 };
 577         char *outfile = 0;
 578         int raw = 0, head = 0;
 579         int out = 1; /* output file descriptor */
 580         int use_tls = 0;
 581         struct io io = { {0}, 0, -1, 0, 0, 0, 0, 0 };
 582         struct TLSContext *clientssl = 0;
 583         int failsilent = 0;
 584         char *lmfile = 0;
 585         int progressbar = 0;
 586         struct tls_buffer request;
 587         char lmtime[80];
 588         char *eoh = 0;
 589         char *user_agent = 0;
 590         size_t total = 0;
 591         size_t header_len;
 592         char *url = 0;
 593         int redirs = 0, redirlimit = 50, printstatus = 0;
 594         int verifypolicy = 1, calcoutfile = 0, ifnewer = 0;
 595
 596         ltc_mp = tfm_desc;
 597
 598         while ((option = getopt(ac, av, "o:OrIfz:np#R:SkKU:")) != -1) {
 599                 switch (option) {
 600                         case 'o': outfile = optarg; break;
 601                         case 'O': calcoutfile = 1; break;
 602                         case 'S': printstatus = 1; head = 1; break;
 603                         case 'k': verifypolicy = 0; break;
 604                         case 'K': verifypolicy = 2; break;
 605                         case 'U': user_agent = optarg; break;
 606                         case 'I': head = 1;
 607                         case 'r': raw = 1; break;
 608                         case 'f': failsilent = 1; break;
 609                         case 'z': lmfile = optarg; break;
 610                         case 'n': ifnewer = 1; break;
 611                         case 'R': redirlimit = strtol(optarg, 0, 10); break;
 612                         case 'p':
 613                         case '#': progressbar = 1; break;
 614                         default:
 615                                   exit(EXIT_FAILURE);
 616                                   break;
 617                 }
 618         }
 619
 620         if (ac < optind) {
 621                 fprintf(stderr, "Usage: %s uri\n", av[0]);
 622                 exit(EXIT_FAILURE);
 623         }
 624
 625         url = strdup(av[optind]);
 626         if (!url) {
 627                 exit(EXIT_FAILURE);
 628         }
 629
 630         io.last_modified = 0;
 631
 632         if (calcoutfile && !outfile) {
 633                 tls_parse_uri(url, &uri);
 634                 outfile = pathlast(uri.path);
 635                 /* outfile leaks memory here, so if this
 636                  * were turned into a library function,
 637                  * we'd need to track it
 638                  */
 639                 if (!outfile) {
 640                         fprintf(stderr, "unable to determine outfile\n");
 641                         exit(EXIT_FAILURE);
 642                 }
 643         }
 644
 645         if (ifnewer && outfile && !lmfile) {
 646                 lmfile = outfile;
 647         }
 648
 649         if (lmfile) {
 650                 struct tm *mtime;
 651                 time_t ts;
 652
 653                 ts = file_mtime(lmfile);
 654
 655                 if (ts == -1) {
 656                         exit(EXIT_FAILURE);
 657                 } else if (ts != 0) {
 658                         io.last_modified = ts;
 659                         mtime = gmtime(&ts);
 660                         strftime(lmtime, sizeof lmtime, "%a, %d %b %Y %H:%M:%S GMT", mtime);
 661                 } else {
 662                         lmfile = 0;
 663                 }
 664         }
 665
 666         signal(SIGPIPE, SIG_IGN);
 667
 668         tls_buffer_init(&io.response, 0);
 669         tls_buffer_init(&request, 128);
 670
 671         while (redirs++ <= redirlimit) {
 672                 tls_free_uri(&uri);
 673                 io.response.len = 0;
 674                 request.len = 0;
 675                 eoh = 0;
 676
 677                 tls_parse_uri(url, &uri);
 678                 host = uri.host;
 679                 port = atoi(uri.port);
 680                 req_file = uri.path;
 681
 682                 /* construct request */
 683                 if (head) {
 684                         tls_buffer_append(&request, "HEAD ", 5);
 685                 } else {
 686                         tls_buffer_append(&request, "GET ", 4);
 687                 }
 688                 tls_buffer_append(&request, uri.encoded_path, strlen(uri.encoded_path));
 689                 if (uri.encoded_query) {
 690                         tls_buffer_append(&request, "?", 1);
 691                         tls_buffer_append(&request, uri.encoded_query, strlen(uri.encoded_query));
 692                 }
 693                 tls_buffer_append(&request, " HTTP/1.1\r\n", 11);
 694
 695                 append_header(&request, "Host", host);
 696                 if (user_agent) {
 697                         append_header(&request, "User-Agent", user_agent);
 698                 }
 699                 append_header(&request, "Accept", "*/*");
 700                 append_header(&request, "Connection", "close");
 701                 if (lmfile) {
 702                         append_header(&request, "If-Modified-Since", lmtime);
 703                 }
 704                 tls_buffer_append(&request, "\r\n", 2);
 705
 706                 if (!strcmp(uri.scheme, "https")) {
 707                         use_tls = 1;
 708
 709                         clientssl = tls_create_context(TLS_CLIENT, TLS_V12);
 710
 711                         /* optionally, we can set a certificate validation
 712                          * callback function if set_verify is not called, and
 713                          * root ca is set, `tls_default_verify` will be used
 714                          * (does exactly what `verify` does in this example)
 715                          */
 716                         if (verifypolicy == 2) {
 717                                 char *cert_path = 0;
 718                                 cert_path = getenv("ZPM_CERTFILE");
 719                                 if (!cert_path) {
 720                                         cert_path = "/var/lib/zpm/roots.pem";
 721                                 }
 722                                 rv = tls_load_root_file(clientssl, cert_path);
 723                                 if (rv == -1) {
 724                                         fprintf(stderr, "Error loading root certs\n");
 725                                         return 1;
 726                                 }
 727                                 tls_set_verify(clientssl, verify_roots);
 728                         } else if (verifypolicy == 1) {
 729                                 tls_set_verify(clientssl, verify_first);
 730                         } else {
 731                                 tls_set_verify(clientssl, verify_trust);
 732                         }
 733
 734                         if (!clientssl) {
 735                                 fprintf(stderr, "Error initializing client context\n");
 736                                 return -1;
 737                         }
 738                         tls_sni_set(clientssl, uri.host);
 739                         clientssl->sync = 1;
 740                         io.tls = clientssl;
 741                         sockfd = open_tcp_connection(host, port);
 742                         if (sockfd < 0) {
 743                                 perror("can't open connection");
 744                                 exit(EXIT_FAILURE);
 745                         }
 746                         tls_set_fd(clientssl, sockfd);
 747                         if ((rv = tls_connect(clientssl)) != 1) {
 748                                 fprintf(stderr, "Handshake Error %i\n", rv);
 749                                 return 1;
 750                         }
 751                         ret = tls_write(clientssl, request.buffer, request.len);
 752                 } else if (!strcmp(uri.scheme, "http")) {
 753                         sockfd = open_tcp_connection(host, port);
 754                         if (sockfd < 0) {
 755                                 perror("can't open connection");
 756                                 exit(EXIT_FAILURE);
 757                         }
 758                         ret = write(sockfd, request.buffer, request.len);
 759                 } else if (!strcmp(uri.scheme, "file")) {
 760                         sockfd = open(uri.path, O_RDONLY);
 761                         fake_header(&io, sockfd);
 762                         ret = 0;
 763                 } else {
 764                         fprintf(stderr, "scheme %s unknown\n", uri.scheme);
 765                         exit(EXIT_FAILURE);
 766                 }
 767
 768                 if (ret == -1) {
 769                         fprintf(stderr, "unable to write http request: %s\n", strerror(errno));
 770                         exit(EXIT_FAILURE);
 771                 }
 772
 773                 io.socket = sockfd;
 774
 775                 eoh = 0;
 776                 do {
 777                         if (io.response.len >= 4) {
 778                                 eoh = strstr(io.response.buffer, "\r\n\r\n");
 779                         }
 780                         if (!eoh) {
 781                                 ret = fill_buffer(&io);
 782                                 if (ret <= 0) {
 783                                         break;
 784                                 }
 785                         }
 786                 } while (!eoh);
 787
 788                 if (!eoh) {
 789                         /* never got (complete) header */
 790                         fprintf(stderr, "incomplete response (ret = %zd) to %s\n", ret, url);
 791                         fprintf(stderr, "have:\n");
 792                         fwrite(io.response.buffer, io.response.len, 1, stderr);
 793                         exit(EXIT_FAILURE);
 794                 }
 795
 796                 header_len = (size_t)(eoh - io.response.buffer) + 4;
 797                 parse_header(&io);
 798
 799                 switch (io.status_code) {
 800                         case 304:
 801                                 progressbar = 0;
 802                                 break;
 803                         case 301:
 804                         case 302:
 805                         case 303:
 806                         case 307:
 807                                 free(url);
 808                                 url = strdup(io.redirect);
 809                                 close(io.socket);
 810                                 continue;
 811                                 break;
 812                 }
 813
 814                 if (printstatus) {
 815                         printf("%d\n", io.status_code);
 816                         break;
 817                 }
 818
 819                 if (!raw) {
 820                         tls_buffer_shift(&io.response, header_len);
 821                 }
 822                 if (head) {
 823                         io.response.len -= 2;
 824                 }
 825
 826                 if (progressbar) {
 827                         if (io.content_length) {
 828                                 fprintf(stderr, "(%lu) ", io.content_length);
 829                         }
 830                 }
 831
 832                 if (outfile) {
 833                         out = open(outfile, O_WRONLY|O_CREAT, 0600);
 834                         if (out == -1) {
 835                                 perror("can't open output file:");
 836                                 exit(EXIT_FAILURE);
 837                         }
 838                 }
 839
 840                 do {
 841                         write(out, io.response.buffer, io.response.len);
 842                         ret = io.response.len;
 843                         io.response.len = 0;
 844
 845                         if (progressbar) {
 846                                 if (io.content_length) {
 847                                         pdots(50, '.', total, total+ret,
 848                                                         io.content_length);
 849                                 } else {
 850                                         putc('\r', stderr);
 851                                         fprintf(stderr, "%zu", total+ret);
 852                                 }
 853                                 total += ret;
 854                         }
 855                         if (head) {
 856                                 break;
 857                         }
 858                         ret = fill_buffer(&io);
 859                 } while (ret > 0);
 860
 861                 if (ret < 0) {
 862                         fprintf(stderr, "%s read error %zd\n", uri.scheme, ret);
 863                 }
 864                 struct timespec ts[2];
 865                 ts[0].tv_sec = 0; ts[0].tv_nsec = UTIME_OMIT;
 866                 ts[1].tv_sec = io.last_modified;
 867                 ts[1].tv_nsec = 0;
 868
 869                 futimens(out, ts);
 870                 close(out);
 871                 tls_buffer_free(&io.response);
 872                 break;
 873         }
 874
 875         if (use_tls) {
 876                 tls_shutdown(clientssl);
 877                 tls_free(clientssl);
 878         }
 879
 880         close(sockfd);
 881         if (progressbar && io.status_code == 200) {
 882                 fprintf(stderr, "(%lu)", total);
 883                 putc('\n',stderr);
 884         }
 885
 886         return io.status_code < 400 ? 0 : EXIT_FAILURE;
 887 }