package/uhttpd/src/uhttpd-utils.c

   1 /*
   2  * uhttpd - Tiny single-threaded 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 cl->server->conf->tls_send(cl, (void *)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 = cl->server->conf->tls_recv(cl, (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                 "Connection: close\r\n"
 175                 "Content-Type: text/plain\r\n"
 176                 "Transfer-Encoding: chunked\r\n\r\n",
 177                         code, summary
 178         );
 179
 180         ensure(uh_tcp_send(cl, buffer, len));
 181
 182         va_start(ap, fmt);
 183         len = vsnprintf(buffer, sizeof(buffer), fmt, ap);
 184         va_end(ap);
 185
 186         ensure(uh_http_sendc(cl, buffer, len));
 187         ensure(uh_http_sendc(cl, NULL, 0));
 188
 189         return 0;
 190 }
 191
 192
 193 int uh_http_sendc(struct client *cl, const char *data, int len)
 194 {
 195         char chunk[8];
 196         int clen;
 197
 198         if( len == -1 )
 199                 len = strlen(data);
 200
 201         if( len > 0 )
 202         {
 203                 clen = snprintf(chunk, sizeof(chunk), "%X\r\n", len);
 204                 ensure(uh_tcp_send(cl, chunk, clen));
 205                 ensure(uh_tcp_send(cl, data, len));
 206                 ensure(uh_tcp_send(cl, "\r\n", 2));
 207         }
 208         else
 209         {
 210                 ensure(uh_tcp_send(cl, "0\r\n\r\n", 5));
 211         }
 212
 213         return 0;
 214 }
 215
 216 int uh_http_sendf(
 217         struct client *cl, struct http_request *req, const char *fmt, ...
 218 ) {
 219         va_list ap;
 220         char buffer[UH_LIMIT_MSGHEAD];
 221         int len;
 222
 223         va_start(ap, fmt);
 224         len = vsnprintf(buffer, sizeof(buffer), fmt, ap);
 225         va_end(ap);
 226
 227         if( (req != NULL) && (req->version > 1.0) )
 228                 ensure(uh_http_sendc(cl, buffer, len));
 229         else if( len > 0 )
 230                 ensure(uh_tcp_send(cl, buffer, len));
 231
 232         return 0;
 233 }
 234
 235 int uh_http_send(
 236         struct client *cl, struct http_request *req, const char *buf, int len
 237 ) {
 238         if( len < 0 )
 239                 len = strlen(buf);
 240
 241         if( (req != NULL) && (req->version > 1.0) )
 242                 ensure(uh_http_sendc(cl, buf, len));
 243         else if( len > 0 )
 244                 ensure(uh_tcp_send(cl, buf, len));
 245
 246         return 0;
 247 }
 248
 249
 250 int uh_urldecode(char *buf, int blen, const char *src, int slen)
 251 {
 252         int i;
 253         int len = 0;
 254
 255 #define hex(x) \
 256         (((x) <= '9') ? ((x) - '0') : \
 257                 (((x) <= 'F') ? ((x) - 'A' + 10) : \
 258                         ((x) - 'a' + 10)))
 259
 260         for( i = 0; (i <= slen) && (i <= blen); i++ )
 261         {
 262                 if( src[i] == '%' )
 263                 {
 264                         if( ((i+2) <= slen) && isxdigit(src[i+1]) && isxdigit(src[i+2]) )
 265                         {
 266                                 buf[len++] = (char)(16 * hex(src[i+1]) + hex(src[i+2]));
 267                                 i += 2;
 268                         }
 269                         else
 270                         {
 271                                 buf[len++] = '%';
 272                         }
 273                 }
 274                 else
 275                 {
 276                         buf[len++] = src[i];
 277                 }
 278         }
 279
 280         return len;
 281 }
 282
 283 int uh_urlencode(char *buf, int blen, const char *src, int slen)
 284 {
 285         int i;
 286         int len = 0;
 287         const char hex[] = "0123456789abcdef";
 288
 289         for( i = 0; (i <= slen) && (i <= blen); i++ )
 290         {
 291                 if( isalnum(src[i]) || (src[i] == '-') || (src[i] == '_') ||
 292                     (src[i] == '.') || (src[i] == '~') )
 293                 {
 294                         buf[len++] = src[i];
 295                 }
 296                 else if( (len+3) <= blen )
 297                 {
 298                         buf[len++] = '%';
 299                         buf[len++] = hex[(src[i] >> 4) & 15];
 300                         buf[len++] = hex[(src[i] & 15) & 15];
 301                 }
 302                 else
 303                 {
 304                         break;
 305                 }
 306         }
 307
 308         return len;
 309 }
 310
 311 int uh_b64decode(char *buf, int blen, const unsigned char *src, int slen)
 312 {
 313         int i = 0;
 314         int len = 0;
 315
 316         unsigned int cin  = 0;
 317         unsigned int cout = 0;
 318
 319
 320         for( i = 0; (i <= slen) && (src[i] != 0); i++ )
 321         {
 322                 cin = src[i];
 323
 324                 if( (cin >= '0') && (cin <= '9') )
 325                         cin = cin - '0' + 52;
 326                 else if( (cin >= 'A') && (cin <= 'Z') )
 327                         cin = cin - 'A';
 328                 else if( (cin >= 'a') && (cin <= 'z') )
 329                         cin = cin - 'a' + 26;
 330                 else if( cin == '+' )
 331                         cin = 62;
 332                 else if( cin == '/' )
 333                         cin = 63;
 334                 else if( cin == '=' )
 335                         cin = 0;
 336                 else
 337                         continue;
 338
 339                 cout = (cout << 6) | cin;
 340
 341                 if( (i % 4) == 3 )
 342                 {
 343                         if( (len + 3) < blen )
 344                         {
 345                                 buf[len++] = (char)(cout >> 16);
 346                                 buf[len++] = (char)(cout >> 8);
 347                                 buf[len++] = (char)(cout);
 348                         }
 349                         else
 350                         {
 351                                 break;
 352                         }
 353                 }
 354         }
 355
 356         buf[len++] = 0;
 357         return len;
 358 }
 359
 360
 361 struct path_info * uh_path_lookup(struct client *cl, const char *url)
 362 {
 363         static char path_phys[PATH_MAX];
 364         static char path_info[PATH_MAX];
 365         static struct path_info p;
 366
 367         char buffer[UH_LIMIT_MSGHEAD];
 368         char *docroot = cl->server->conf->docroot;
 369         char *pathptr = NULL;
 370
 371         int i = 0;
 372         struct stat s;
 373
 374
 375         memset(path_phys, 0, sizeof(path_phys));
 376         memset(path_info, 0, sizeof(path_info));
 377         memset(buffer, 0, sizeof(buffer));
 378         memset(&p, 0, sizeof(p));
 379
 380         /* copy docroot */
 381         memcpy(buffer, docroot,
 382                 min(strlen(docroot), sizeof(buffer) - 1));
 383
 384         /* separate query string from url */
 385         if( (pathptr = strchr(url, '?')) != NULL )
 386         {
 387                 p.query = pathptr[1] ? pathptr + 1 : NULL;
 388
 389                 /* urldecode component w/o query */
 390                 if( pathptr > url )
 391                         uh_urldecode(
 392                                 &buffer[strlen(docroot)],
 393                                 sizeof(buffer) - strlen(docroot) - 1,
 394                                 url, (int)(pathptr - url) - 1
 395                         );
 396         }
 397
 398         /* no query string, decode all of url */
 399         else
 400         {
 401                 uh_urldecode(
 402                         &buffer[strlen(docroot)],
 403                         sizeof(buffer) - strlen(docroot) - 1,
 404                         url, strlen(url)
 405                 );
 406         }
 407
 408         /* create canon path */
 409         for( i = strlen(buffer); i >= 0; i-- )
 410         {
 411                 if( (buffer[i] == 0) || (buffer[i] == '/') )
 412                 {
 413                         memset(path_info, 0, sizeof(path_info));
 414                         memcpy(path_info, buffer, min(i + 1, sizeof(path_info) - 1));
 415
 416                         if( realpath(path_info, path_phys) )
 417                         {
 418                                 memset(path_info, 0, sizeof(path_info));
 419                                 memcpy(path_info, &buffer[i],
 420                                         min(strlen(buffer) - i, sizeof(path_info) - 1));
 421
 422                                 break;
 423                         }
 424                 }
 425         }
 426
 427         /* check whether found path is within docroot */
 428         if( strncmp(path_phys, docroot, strlen(docroot)) ||
 429             ((path_phys[strlen(docroot)] != 0) &&
 430                  (path_phys[strlen(docroot)] != '/'))
 431         ) {
 432                 return NULL;
 433         }
 434
 435         /* test current path */
 436         if( ! stat(path_phys, &p.stat) )
 437         {
 438                 /* is a regular file */
 439                 if( p.stat.st_mode & S_IFREG )
 440                 {
 441                         p.root = docroot;
 442                         p.phys = path_phys;
 443                         p.name = &path_phys[strlen(docroot)];
 444                         p.info = path_info[0] ? path_info : NULL;
 445                 }
 446
 447                 /* is a directory */
 448                 else if( (p.stat.st_mode & S_IFDIR) && !strlen(path_info) )
 449                 {
 450                         /* ensure trailing slash */
 451                         if( path_phys[strlen(path_phys)-1] != '/' )
 452                                 path_phys[strlen(path_phys)] = '/';
 453
 454                         /* try to locate index file */
 455                         memset(buffer, 0, sizeof(buffer));
 456                         memcpy(buffer, path_phys, sizeof(buffer));
 457                         pathptr = &buffer[strlen(buffer)];
 458
 459                         for( i = 0; i < array_size(uh_index_files); i++ )
 460                         {
 461                                 strncat(buffer, uh_index_files[i], sizeof(buffer));
 462
 463                                 if( !stat(buffer, &s) && (s.st_mode & S_IFREG) )
 464                                 {
 465                                         memcpy(path_phys, buffer, sizeof(path_phys));
 466                                         memcpy(&p.stat, &s, sizeof(p.stat));
 467                                         break;
 468                                 }
 469
 470                                 *pathptr = 0;
 471                         }
 472
 473                         p.root = docroot;
 474                         p.phys = path_phys;
 475                         p.name = &path_phys[strlen(docroot)];
 476                 }
 477         }
 478
 479         return p.phys ? &p : NULL;
 480 }
 481
 482
 483 static char uh_realms[UH_LIMIT_AUTHREALMS * sizeof(struct auth_realm)] = { 0 };
 484 static int uh_realm_count = 0;
 485
 486 struct auth_realm * uh_auth_add(char *path, 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->path, path,
 500                         min(strlen(path), sizeof(new->path) - 1));
 501
 502                 memcpy(new->user, user,
 503                         min(strlen(user), sizeof(new->user) - 1));
 504
 505                 /* given password refers to a passwd entry */
 506                 if( (strlen(pass) > 3) && !strncmp(pass, "$p$", 3) )
 507                 {
 508                         /* try to resolve shadow entry */
 509                         if( ((spwd = getspnam(&pass[3])) != NULL) && spwd->sp_pwdp )
 510                         {
 511                                 memcpy(new->pass, spwd->sp_pwdp,
 512                                         min(strlen(spwd->sp_pwdp), sizeof(new->pass) - 1));
 513                         }
 514
 515                         /* try to resolve passwd entry */
 516                         else if( ((pwd = getpwnam(&pass[3])) != NULL) && pwd->pw_passwd &&
 517                                 (pwd->pw_passwd[0] != '!') && (pwd->pw_passwd[0] != 0)
 518                         ) {
 519                                 memcpy(new->pass, pwd->pw_passwd,
 520                                         min(strlen(pwd->pw_passwd), sizeof(new->pass) - 1));
 521                         }
 522                 }
 523
 524                 /* ordinary pwd */
 525                 else
 526                 {
 527                         memcpy(new->pass, pass,
 528                                 min(strlen(pass), sizeof(new->pass) - 1));
 529                 }
 530
 531                 uh_realm_count++;
 532         }
 533
 534         return new;
 535 }
 536
 537 int uh_auth_check(
 538         struct client *cl, struct http_request *req, struct path_info *pi
 539 ) {
 540         int i, plen, rlen, protected;
 541         char buffer[UH_LIMIT_MSGHEAD];
 542         char *user = NULL;
 543         char *pass = NULL;
 544
 545         struct auth_realm *realm = NULL;
 546
 547         plen = strlen(pi->name);
 548         protected = 0;
 549
 550         /* check whether at least one realm covers the requested url */
 551         for( i = 0; i < uh_realm_count; i++ )
 552         {
 553                 realm = (struct auth_realm *)
 554                         &uh_realms[i * sizeof(struct auth_realm)];
 555
 556                 rlen = strlen(realm->path);
 557
 558                 if( (plen >= rlen) && !strncasecmp(pi->name, realm->path, rlen) )
 559                 {
 560                         req->realm = realm;
 561                         protected = 1;
 562                         break;
 563                 }
 564         }
 565
 566         /* requested resource is covered by a realm */
 567         if( protected )
 568         {
 569                 /* try to get client auth info */
 570                 foreach_header(i, req->headers)
 571                 {
 572                         if( !strcasecmp(req->headers[i], "Authorization") &&
 573                                 (strlen(req->headers[i+1]) > 6) &&
 574                                 !strncasecmp(req->headers[i+1], "Basic ", 6)
 575                         ) {
 576                                 memset(buffer, 0, sizeof(buffer));
 577                                 uh_b64decode(buffer, sizeof(buffer) - 1,
 578                                         (unsigned char *) &req->headers[i+1][6],
 579                                         strlen(req->headers[i+1]) - 6);
 580
 581                                 if( (pass = strchr(buffer, ':')) != NULL )
 582                                 {
 583                                         user = buffer;
 584                                         *pass++ = 0;
 585                                 }
 586
 587                                 break;
 588                         }
 589                 }
 590
 591                 /* have client auth */
 592                 if( user && pass )
 593                 {
 594                         /* find matching realm */
 595                         for( i = 0, realm = NULL; i < uh_realm_count; i++ )
 596                         {
 597                                 realm = (struct auth_realm *)
 598                                         &uh_realms[i * sizeof(struct auth_realm)];
 599
 600                                 rlen = strlen(realm->path);
 601
 602                                 if( (plen >= rlen) &&
 603                                     !strncasecmp(pi->name, realm->path, rlen) &&
 604                                     !strcmp(user, realm->user)
 605                                 ) {
 606                                         req->realm = realm;
 607                                         break;
 608                                 }
 609
 610                                 realm = NULL;
 611                         }
 612
 613                         /* found a realm matching the username */
 614                         if( realm )
 615                         {
 616                                 /* is a crypt passwd */
 617                                 if( realm->pass[0] == '$' )
 618                                         pass = crypt(pass, realm->pass);
 619
 620                                 /* check user pass */
 621                                 if( !strcmp(pass, realm->pass) )
 622                                         return 1;
 623                         }
 624                 }
 625
 626                 /* 401 */
 627                 uh_http_sendf(cl, NULL,
 628                         "HTTP/%.1f 401 Authorization Required\r\n"
 629                         "WWW-Authenticate: Basic realm=\"%s\"\r\n"
 630                         "Content-Type: text/plain\r\n"
 631                         "Content-Length: 23\r\n\r\n"
 632                         "Authorization Required\n",
 633                                 req->version, cl->server->conf->realm
 634                 );
 635
 636                 return 0;
 637         }
 638
 639         return 1;
 640 }
 641
 642
 643 static char uh_listeners[UH_LIMIT_LISTENERS * sizeof(struct listener)] = { 0 };
 644 static char uh_clients[UH_LIMIT_CLIENTS * sizeof(struct client)] = { 0 };
 645
 646 static int uh_listener_count = 0;
 647 static int uh_client_count = 0;
 648
 649
 650 struct listener * uh_listener_add(int sock, struct config *conf)
 651 {
 652         struct listener *new = NULL;
 653         socklen_t sl;
 654
 655         if( uh_listener_count < UH_LIMIT_LISTENERS )
 656         {
 657                 new = (struct listener *)
 658                         &uh_listeners[uh_listener_count * sizeof(struct listener)];
 659
 660                 new->socket = sock;
 661                 new->conf   = conf;
 662
 663                 /* get local endpoint addr */
 664                 sl = sizeof(struct sockaddr_in6);
 665                 memset(&(new->addr), 0, sl);
 666                 getsockname(sock, (struct sockaddr *) &(new->addr), &sl);
 667
 668                 uh_listener_count++;
 669         }
 670
 671         return new;
 672 }
 673
 674 struct listener * uh_listener_lookup(int sock)
 675 {
 676         struct listener *cur = NULL;
 677         int i;
 678
 679         for( i = 0; i < uh_listener_count; i++ )
 680         {
 681                 cur = (struct listener *) &uh_listeners[i * sizeof(struct listener)];
 682
 683                 if( cur->socket == sock )
 684                         return cur;
 685         }
 686
 687         return NULL;
 688 }
 689
 690
 691 struct client * uh_client_add(int sock, struct listener *serv)
 692 {
 693         struct client *new = NULL;
 694         socklen_t sl;
 695
 696         if( uh_client_count < UH_LIMIT_CLIENTS )
 697         {
 698                 new = (struct client *)
 699                         &uh_clients[uh_client_count * sizeof(struct client)];
 700
 701                 new->socket = sock;
 702                 new->server = serv;
 703
 704                 /* get remote endpoint addr */
 705                 sl = sizeof(struct sockaddr_in6);
 706                 memset(&(new->peeraddr), 0, sl);
 707                 getpeername(sock, (struct sockaddr *) &(new->peeraddr), &sl);
 708
 709                 /* get local endpoint addr */
 710                 sl = sizeof(struct sockaddr_in6);
 711                 memset(&(new->servaddr), 0, sl);
 712                 getsockname(sock, (struct sockaddr *) &(new->servaddr), &sl);
 713
 714                 uh_client_count++;
 715         }
 716
 717         return new;
 718 }
 719
 720 struct client * uh_client_lookup(int sock)
 721 {
 722         struct client *cur = NULL;
 723         int i;
 724
 725         for( i = 0; i < uh_client_count; i++ )
 726         {
 727                 cur = (struct client *) &uh_clients[i * sizeof(struct client)];
 728
 729                 if( cur->socket == sock )
 730                         return cur;
 731         }
 732
 733         return NULL;
 734 }
 735
 736 void uh_client_remove(int sock)
 737 {
 738         struct client *del = uh_client_lookup(sock);
 739
 740         if( del )
 741         {
 742                 memmove(del, del + 1,
 743                         sizeof(uh_clients) - (int)((char *)del - uh_clients) - sizeof(struct client));
 744
 745                 uh_client_count--;
 746         }
 747 }
 748
 749