contrib/package/uhttpd/src/uhttpd-utils.c

   1 /*
   2  * uhttpd - Tiny non-forking httpd - Utility functions
   3  *
   4  *   Copyright (C) 2010 Jo-Philipp Wich <xm@subsignal.org>
   5  *
   6  *  Licensed under the Apache License, Version 2.0 (the "License");
   7  *  you may not use this file except in compliance with the License.
   8  *  You may obtain a copy of the License at
   9  *
  10  *      http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  *  Unless required by applicable law or agreed to in writing, software
  13  *  distributed under the License is distributed on an "AS IS" BASIS,
  14  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15  *  See the License for the specific language governing permissions and
  16  *  limitations under the License.
  17  */
  18
  19 #define _XOPEN_SOURCE 500       /* crypt() */
  20 #define _BSD_SOURCE                     /* strcasecmp(), strncasecmp() */
  21
  22 #include "uhttpd.h"
  23 #include "uhttpd-utils.h"
  24
  25 #ifdef HAVE_TLS
  26 #include "uhttpd-tls.h"
  27 #endif
  28
  29
  30 static char *uh_index_files[] = {
  31         "index.html",
  32         "index.htm",
  33         "default.html",
  34         "default.htm"
  35 };
  36
  37
  38 const char * sa_straddr(void *sa)
  39 {
  40         static char str[INET6_ADDRSTRLEN];
  41         struct sockaddr_in *v4 = (struct sockaddr_in *)sa;
  42         struct sockaddr_in6 *v6 = (struct sockaddr_in6 *)sa;
  43
  44         if( v4->sin_family == AF_INET )
  45                 return inet_ntop(AF_INET, &(v4->sin_addr), str, sizeof(str));
  46         else
  47                 return inet_ntop(AF_INET6, &(v6->sin6_addr), str, sizeof(str));
  48 }
  49
  50 const char * sa_strport(void *sa)
  51 {
  52         static char str[6];
  53         snprintf(str, sizeof(str), "%i", sa_port(sa));
  54         return str;
  55 }
  56
  57 int sa_port(void *sa)
  58 {
  59         return ntohs(((struct sockaddr_in6 *)sa)->sin6_port);
  60 }
  61
  62 /* Simple strstr() like function that takes len arguments for both haystack and needle. */
  63 char *strfind(char *haystack, int hslen, const char *needle, int ndlen)
  64 {
  65         int match = 0;
  66         int i, j;
  67
  68         for( i = 0; i < hslen; i++ )
  69         {
  70                 if( haystack[i] == needle[0] )
  71                 {
  72                         match = ((ndlen == 1) || ((i + ndlen) <= hslen));
  73
  74                         for( j = 1; (j < ndlen) && ((i + j) < hslen); j++ )
  75                         {
  76                                 if( haystack[i+j] != needle[j] )
  77                                 {
  78                                         match = 0;
  79                                         break;
  80                                 }
  81                         }
  82
  83                         if( match )
  84                                 return &haystack[i];
  85                 }
  86         }
  87
  88         return NULL;
  89 }
  90
  91
  92 int uh_tcp_send(struct client *cl, const char *buf, int len)
  93 {
  94         fd_set writer;
  95         struct timeval timeout;
  96
  97         FD_ZERO(&writer);
  98         FD_SET(cl->socket, &writer);
  99
 100         timeout.tv_sec = 0;
 101         timeout.tv_usec = 500000;
 102
 103         if( select(cl->socket + 1, NULL, &writer, NULL, &timeout) > 0 )
 104         {
 105 #ifdef HAVE_TLS
 106                 if( cl->tls )
 107                         return SSL_write(cl->tls, buf, len);
 108                 else
 109 #endif
 110                         return send(cl->socket, buf, len, 0);
 111         }
 112
 113         return -1;
 114 }
 115
 116 int uh_tcp_peek(struct client *cl, char *buf, int len)
 117 {
 118         int sz = uh_tcp_recv(cl, buf, len);
 119
 120         /* store received data in peek buffer */
 121         if( sz > 0 )
 122         {
 123                 cl->peeklen = sz;
 124                 memcpy(cl->peekbuf, buf, sz);
 125         }
 126
 127         return sz;
 128 }
 129
 130 int uh_tcp_recv(struct client *cl, char *buf, int len)
 131 {
 132         int sz = 0;
 133         int rsz = 0;
 134
 135         /* first serve data from peek buffer */
 136         if( cl->peeklen > 0 )
 137         {
 138                 sz = min(cl->peeklen, len);
 139                 len -= sz; cl->peeklen -= sz;
 140
 141                 memcpy(buf, cl->peekbuf, sz);
 142                 memmove(cl->peekbuf, &cl->peekbuf[sz], cl->peeklen);
 143         }
 144
 145         /* caller wants more */
 146         if( len > 0 )
 147         {
 148 #ifdef HAVE_TLS
 149                 if( cl->tls )
 150                         rsz = SSL_read(cl->tls, (void *)&buf[sz], len);
 151                 else
 152 #endif
 153                         rsz = recv(cl->socket, (void *)&buf[sz], len, 0);
 154
 155                 if( (sz == 0) || (rsz > 0) )
 156                         sz += rsz;
 157         }
 158
 159         return sz;
 160 }
 161
 162 #define ensure(x) \
 163         do { if( x < 0 ) return -1; } while(0)
 164
 165 int uh_http_sendhf(struct client *cl, int code, const char *summary, const char *fmt, ...)
 166 {
 167         va_list ap;
 168
 169         char buffer[UH_LIMIT_MSGHEAD];
 170         int len;
 171
 172         len = snprintf(buffer, sizeof(buffer),
 173                 "HTTP/1.1 %03i %s\r\n"
 174                 "Content-Type: text/plain\r\n"
 175                 "Transfer-Encoding: chunked\r\n\r\n",
 176                         code, summary
 177         );
 178
 179         ensure(uh_tcp_send(cl, buffer, len));
 180
 181         va_start(ap, fmt);
 182         len = vsnprintf(buffer, sizeof(buffer), fmt, ap);
 183         va_end(ap);
 184
 185         ensure(uh_http_sendc(cl, buffer, len));
 186         ensure(uh_http_sendc(cl, NULL, 0));
 187
 188         return 0;
 189 }
 190
 191
 192 int uh_http_sendc(struct client *cl, const char *data, int len)
 193 {
 194         char chunk[8];
 195         int clen;
 196
 197         if( len == -1 )
 198                 len = strlen(data);
 199
 200         if( len > 0 )
 201         {
 202                 clen = snprintf(chunk, sizeof(chunk), "%X\r\n", len);
 203                 ensure(uh_tcp_send(cl, chunk, clen));
 204                 ensure(uh_tcp_send(cl, data, len));
 205                 ensure(uh_tcp_send(cl, "\r\n", 2));
 206         }
 207         else
 208         {
 209                 ensure(uh_tcp_send(cl, "0\r\n\r\n", 5));
 210         }
 211
 212         return 0;
 213 }
 214
 215 int uh_http_sendf(
 216         struct client *cl, struct http_request *req, const char *fmt, ...
 217 ) {
 218         va_list ap;
 219         char buffer[UH_LIMIT_MSGHEAD];
 220         int len;
 221
 222         va_start(ap, fmt);
 223         len = vsnprintf(buffer, sizeof(buffer), fmt, ap);
 224         va_end(ap);
 225
 226         if( (req != NULL) && (req->version > 1.0) )
 227                 ensure(uh_http_sendc(cl, buffer, len));
 228         else if( len > 0 )
 229                 ensure(uh_tcp_send(cl, buffer, len));
 230
 231         return 0;
 232 }
 233
 234 int uh_http_send(
 235         struct client *cl, struct http_request *req, const char *buf, int len
 236 ) {
 237         if( len < 0 )
 238                 len = strlen(buf);
 239
 240         if( (req != NULL) && (req->version > 1.0) )
 241                 ensure(uh_http_sendc(cl, buf, len));
 242         else if( len > 0 )
 243                 ensure(uh_tcp_send(cl, buf, len));
 244
 245         return 0;
 246 }
 247
 248
 249 int uh_urldecode(char *buf, int blen, const char *src, int slen)
 250 {
 251         int i;
 252         int len = 0;
 253
 254 #define hex(x) \
 255         (((x) <= '9') ? ((x) - '0') : \
 256                 (((x) <= 'F') ? ((x) - 'A' + 10) : \
 257                         ((x) - 'a' + 10)))
 258
 259         for( i = 0; (i <= slen) && (i <= blen); i++ )
 260         {
 261                 if( src[i] == '%' )
 262                 {
 263                         if( ((i+2) <= slen) && isxdigit(src[i+1]) && isxdigit(src[i+2]) )
 264                         {
 265                                 buf[len++] = (char)(16 * hex(src[i+1]) + hex(src[i+2]));
 266                                 i += 2;
 267                         }
 268                         else
 269                         {
 270                                 buf[len++] = '%';
 271                         }
 272                 }
 273                 else
 274                 {
 275                         buf[len++] = src[i];
 276                 }
 277         }
 278
 279         return len;
 280 }
 281
 282 int uh_urlencode(char *buf, int blen, const char *src, int slen)
 283 {
 284         int i;
 285         int len = 0;
 286         const char hex[] = "0123456789abcdef";
 287
 288         for( i = 0; (i <= slen) && (i <= blen); i++ )
 289         {
 290                 if( isalnum(src[i]) || (src[i] == '-') || (src[i] == '_') ||
 291                     (src[i] == '.') || (src[i] == '~') )
 292                 {
 293                         buf[len++] = src[i];
 294                 }
 295                 else if( (len+3) <= blen )
 296                 {
 297                         buf[len++] = '%';
 298                         buf[len++] = hex[(src[i] >> 4) & 15];
 299                         buf[len++] = hex[(src[i] & 15) & 15];
 300                 }
 301                 else
 302                 {
 303                         break;
 304                 }
 305         }
 306
 307         return len;
 308 }
 309
 310 int uh_b64decode(char *buf, int blen, const unsigned char *src, int slen)
 311 {
 312         int i = 0;
 313         int len = 0;
 314
 315         unsigned int cin  = 0;
 316         unsigned int cout = 0;
 317
 318
 319         for( i = 0; (i <= slen) && (src[i] != 0); i++ )
 320         {
 321                 cin = src[i];
 322
 323                 if( (cin >= '0') && (cin <= '9') )
 324                         cin = cin - '0' + 52;
 325                 else if( (cin >= 'A') && (cin <= 'Z') )
 326                         cin = cin - 'A';
 327                 else if( (cin >= 'a') && (cin <= 'z') )
 328                         cin = cin - 'a' + 26;
 329                 else if( cin == '+' )
 330                         cin = 62;
 331                 else if( cin == '/' )
 332                         cin = 63;
 333                 else if( cin == '=' )
 334                         cin = 0;
 335                 else
 336                         continue;
 337
 338                 cout = (cout << 6) | cin;
 339
 340                 if( (i % 4) == 3 )
 341                 {
 342                         if( (len + 3) < blen )
 343                         {
 344                                 buf[len++] = (char)(cout >> 16);
 345                                 buf[len++] = (char)(cout >> 8);
 346                                 buf[len++] = (char)(cout);
 347                         }
 348                         else
 349                         {
 350                                 break;
 351                         }
 352                 }
 353         }
 354
 355         buf[len++] = 0;
 356         return len;
 357 }
 358
 359
 360 struct path_info * uh_path_lookup(struct client *cl, const char *url)
 361 {
 362         static char path_phys[PATH_MAX];
 363         static char path_info[PATH_MAX];
 364         static struct path_info p;
 365
 366         char buffer[UH_LIMIT_MSGHEAD];
 367         char *docroot = cl->server->conf->docroot;
 368         char *pathptr = NULL;
 369
 370         int i = 0;
 371         struct stat s;
 372
 373
 374         memset(path_phys, 0, sizeof(path_phys));
 375         memset(path_info, 0, sizeof(path_info));
 376         memset(buffer, 0, sizeof(buffer));
 377         memset(&p, 0, sizeof(p));
 378
 379         /* copy docroot */
 380         memcpy(buffer, docroot,
 381                 min(strlen(docroot), sizeof(buffer) - 1));
 382
 383         /* separate query string from url */
 384         if( (pathptr = strchr(url, '?')) != NULL )
 385         {
 386                 p.query = pathptr[1] ? pathptr + 1 : NULL;
 387
 388                 /* urldecode component w/o query */
 389                 if( pathptr > url )
 390                         uh_urldecode(
 391                                 &buffer[strlen(docroot)],
 392                                 sizeof(buffer) - strlen(docroot) - 1,
 393                                 url, (int)(pathptr - url) - 1
 394                         );
 395         }
 396
 397         /* no query string, decode all of url */
 398         else
 399         {
 400                 uh_urldecode(
 401                         &buffer[strlen(docroot)],
 402                         sizeof(buffer) - strlen(docroot) - 1,
 403                         url, strlen(url)
 404                 );
 405         }
 406
 407         /* create canon path */
 408         for( i = strlen(buffer); i >= 0; i-- )
 409         {
 410                 if( (buffer[i] == 0) || (buffer[i] == '/') )
 411                 {
 412                         memset(path_info, 0, sizeof(path_info));
 413                         memcpy(path_info, buffer, min(i + 1, sizeof(path_info) - 1));
 414
 415                         if( realpath(path_info, path_phys) )
 416                         {
 417                                 memset(path_info, 0, sizeof(path_info));
 418                                 memcpy(path_info, &buffer[i],
 419                                         min(strlen(buffer) - i, sizeof(path_info) - 1));
 420
 421                                 break;
 422                         }
 423                 }
 424         }
 425
 426         /* check whether found path is within docroot */
 427         if( strncmp(path_phys, docroot, strlen(docroot)) ||
 428             ((path_phys[strlen(docroot)] != 0) &&
 429                  (path_phys[strlen(docroot)] != '/'))
 430         ) {
 431                 return NULL;
 432         }
 433
 434         /* test current path */
 435         if( ! stat(path_phys, &p.stat) )
 436         {
 437                 /* is a regular file */
 438                 if( p.stat.st_mode & S_IFREG )
 439                 {
 440                         p.root = docroot;
 441                         p.phys = path_phys;
 442                         p.name = &path_phys[strlen(docroot)];
 443                         p.info = path_info[0] ? path_info : NULL;
 444                 }
 445
 446                 /* is a directory */
 447                 else if( (p.stat.st_mode & S_IFDIR) && !strlen(path_info) )
 448                 {
 449                         /* ensure trailing slash */
 450                         if( path_phys[strlen(path_phys)-1] != '/' )
 451                                 path_phys[strlen(path_phys)] = '/';
 452
 453                         /* try to locate index file */
 454                         memset(buffer, 0, sizeof(buffer));
 455                         memcpy(buffer, path_phys, sizeof(buffer));
 456                         pathptr = &buffer[strlen(buffer)];
 457
 458                         for( i = 0; i < array_size(uh_index_files); i++ )
 459                         {
 460                                 strncat(buffer, uh_index_files[i], sizeof(buffer));
 461
 462                                 if( !stat(buffer, &s) && (s.st_mode & S_IFREG) )
 463                                 {
 464                                         memcpy(path_phys, buffer, sizeof(path_phys));
 465                                         memcpy(&p.stat, &s, sizeof(p.stat));
 466                                         break;
 467                                 }
 468
 469                                 *pathptr = 0;
 470                         }
 471
 472                         p.root = docroot;
 473                         p.phys = path_phys;
 474                         p.name = &path_phys[strlen(docroot)];
 475                 }
 476         }
 477
 478         return p.phys ? &p : NULL;
 479 }
 480
 481
 482 static char uh_realms[UH_LIMIT_AUTHREALMS * sizeof(struct auth_realm)] = { 0 };
 483 static int uh_realm_count = 0;
 484
 485 struct auth_realm * uh_auth_add(
 486         char *path, char *realm, char *user, char *pass
 487 ) {
 488         struct auth_realm *new = NULL;
 489         struct passwd *pwd;
 490         struct spwd *spwd;
 491
 492         if( uh_realm_count < UH_LIMIT_AUTHREALMS )
 493         {
 494                 new = (struct auth_realm *)
 495                         &uh_realms[uh_realm_count * sizeof(struct auth_realm)];
 496
 497                 memset(new, 0, sizeof(struct auth_realm));
 498
 499                 memcpy(new->realm, realm,
 500                         min(strlen(realm), sizeof(new->realm) - 1));
 501
 502                 memcpy(new->path, path,
 503                         min(strlen(path), sizeof(new->path) - 1));
 504
 505                 memcpy(new->user, user,
 506                         min(strlen(user), sizeof(new->user) - 1));
 507
 508                 /* given password refers to a passwd entry */
 509                 if( (strlen(pass) > 3) && !strncmp(pass, "$p$", 3) )
 510                 {
 511                         /* try to resolve shadow entry */
 512                         if( ((spwd = getspnam(&pass[3])) != NULL) && spwd->sp_pwdp )
 513                         {
 514                                 memcpy(new->pass, spwd->sp_pwdp,
 515                                         min(strlen(spwd->sp_pwdp), sizeof(new->pass) - 1));
 516                         }
 517
 518                         /* try to resolve passwd entry */
 519                         else if( ((pwd = getpwnam(&pass[3])) != NULL) && pwd->pw_passwd &&
 520                                 (pwd->pw_passwd[0] != '!') && (pwd->pw_passwd[0] != 0)
 521                         ) {
 522                                 memcpy(new->pass, pwd->pw_passwd,
 523                                         min(strlen(pwd->pw_passwd), sizeof(new->pass) - 1));
 524                         }
 525                 }
 526
 527                 /* ordinary pwd */
 528                 else
 529                 {
 530                         memcpy(new->pass, pass,
 531                                 min(strlen(pass), sizeof(new->pass) - 1));
 532                 }
 533
 534                 uh_realm_count++;
 535         }
 536
 537         return new;
 538 }
 539
 540 int uh_auth_check(
 541         struct client *cl, struct http_request *req, struct path_info *pi
 542 ) {
 543         int i, plen, rlen, protected;
 544         char buffer[UH_LIMIT_MSGHEAD];
 545         char *user = NULL;
 546         char *pass = NULL;
 547
 548         struct auth_realm *realm = NULL;
 549
 550         plen = strlen(pi->name);
 551         protected = 0;
 552
 553         /* check whether at least one realm covers the requested url */
 554         for( i = 0; i < uh_realm_count; i++ )
 555         {
 556                 realm = (struct auth_realm *)
 557                         &uh_realms[i * sizeof(struct auth_realm)];
 558
 559                 rlen = strlen(realm->path);
 560
 561                 if( (plen >= rlen) && !strncasecmp(pi->name, realm->path, rlen) )
 562                 {
 563                         req->realm = realm;
 564                         protected = 1;
 565                         break;
 566                 }
 567         }
 568
 569         /* requested resource is covered by a realm */
 570         if( protected )
 571         {
 572                 /* try to get client auth info */
 573                 foreach_header(i, req->headers)
 574                 {
 575                         if( !strcasecmp(req->headers[i], "Authorization") &&
 576                                 (strlen(req->headers[i+1]) > 6) &&
 577                                 !strncasecmp(req->headers[i+1], "Basic ", 6)
 578                         ) {
 579                                 memset(buffer, 0, sizeof(buffer));
 580                                 uh_b64decode(buffer, sizeof(buffer) - 1,
 581                                         (unsigned char *) &req->headers[i+1][6],
 582                                         strlen(req->headers[i+1]) - 6);
 583
 584                                 if( (pass = strchr(buffer, ':')) != NULL )
 585                                 {
 586                                         user = buffer;
 587                                         *pass++ = 0;
 588                                 }
 589
 590                                 break;
 591                         }
 592                 }
 593
 594                 /* have client auth */
 595                 if( user && pass )
 596                 {
 597                         /* find matching realm */
 598                         for( i = 0, realm = NULL; i < uh_realm_count; i++ )
 599                         {
 600                                 realm = (struct auth_realm *)
 601                                         &uh_realms[i * sizeof(struct auth_realm)];
 602
 603                                 rlen = strlen(realm->path);
 604
 605                                 if( (plen >= rlen) &&
 606                                     !strncasecmp(pi->name, realm->path, rlen) &&
 607                                     !strcmp(user, realm->user)
 608                                 ) {
 609                                         req->realm = realm;
 610                                         break;
 611                                 }
 612
 613                                 realm = NULL;
 614                         }
 615
 616                         /* found a realm matching the username */
 617                         if( realm )
 618                         {
 619                                 /* is a crypt passwd */
 620                                 if( realm->pass[0] == '$' )
 621                                         pass = crypt(pass, realm->pass);
 622
 623                                 /* check user pass */
 624                                 if( !strcmp(pass, realm->pass) )
 625                                         return 1;
 626                         }
 627                 }
 628
 629                 /* 401 */
 630                 uh_http_sendf(cl, NULL,
 631                         "HTTP/%.1f 401 Authorization Required\r\n"
 632                         "WWW-Authenticate: Basic realm=\"%s\"\r\n"
 633                         "Content-Type: text/plain\r\n"
 634                         "Content-Length: 23\r\n\r\n"
 635                         "Authorization Required\n",
 636                                 req->version, realm ? realm->realm : ""
 637                 );
 638
 639                 return 0;
 640         }
 641
 642         return 1;
 643 }
 644
 645
 646 static char uh_listeners[UH_LIMIT_LISTENERS * sizeof(struct listener)] = { 0 };
 647 static char uh_clients[UH_LIMIT_CLIENTS * sizeof(struct client)] = { 0 };
 648
 649 static int uh_listener_count = 0;
 650 static int uh_client_count = 0;
 651
 652
 653 struct listener * uh_listener_add(int sock, struct config *conf)
 654 {
 655         struct listener *new = NULL;
 656         socklen_t sl;
 657
 658         if( uh_listener_count < UH_LIMIT_LISTENERS )
 659         {
 660                 new = (struct listener *)
 661                         &uh_listeners[uh_listener_count * sizeof(struct listener)];
 662
 663                 new->socket = sock;
 664                 new->conf   = conf;
 665
 666                 /* get local endpoint addr */
 667                 sl = sizeof(struct sockaddr_in6);
 668                 memset(&(new->addr), 0, sl);
 669                 getsockname(sock, (struct sockaddr *) &(new->addr), &sl);
 670
 671                 uh_listener_count++;
 672         }
 673
 674         return new;
 675 }
 676
 677 struct listener * uh_listener_lookup(int sock)
 678 {
 679         struct listener *cur = NULL;
 680         int i;
 681
 682         for( i = 0; i < uh_listener_count; i++ )
 683         {
 684                 cur = (struct listener *) &uh_listeners[i * sizeof(struct listener)];
 685
 686                 if( cur->socket == sock )
 687                         return cur;
 688         }
 689
 690         return NULL;
 691 }
 692
 693
 694 struct client * uh_client_add(int sock, struct listener *serv)
 695 {
 696         struct client *new = NULL;
 697         socklen_t sl;
 698
 699         if( uh_client_count < UH_LIMIT_CLIENTS )
 700         {
 701                 new = (struct client *)
 702                         &uh_clients[uh_client_count * sizeof(struct client)];
 703
 704                 new->socket = sock;
 705                 new->server = serv;
 706
 707                 /* get remote endpoint addr */
 708                 sl = sizeof(struct sockaddr_in6);
 709                 memset(&(new->peeraddr), 0, sl);
 710                 getpeername(sock, (struct sockaddr *) &(new->peeraddr), &sl);
 711
 712                 /* get local endpoint addr */
 713                 sl = sizeof(struct sockaddr_in6);
 714                 memset(&(new->servaddr), 0, sl);
 715                 getsockname(sock, (struct sockaddr *) &(new->servaddr), &sl);
 716
 717                 uh_client_count++;
 718         }
 719
 720         return new;
 721 }
 722
 723 struct client * uh_client_lookup(int sock)
 724 {
 725         struct client *cur = NULL;
 726         int i;
 727
 728         for( i = 0; i < uh_client_count; i++ )
 729         {
 730                 cur = (struct client *) &uh_clients[i * sizeof(struct client)];
 731
 732                 if( cur->socket == sock )
 733                         return cur;
 734         }
 735
 736         return NULL;
 737 }
 738
 739 void uh_client_remove(int sock)
 740 {
 741         struct client *del = uh_client_lookup(sock);
 742
 743         if( del )
 744         {
 745                 memmove(del, del + 1,
 746                         sizeof(uh_clients) - (int)((char *)del - uh_clients) - sizeof(struct client));
 747
 748                 uh_client_count--;
 749         }
 750 }
 751
 752