fcgi_protocol.c

   1 /*
   2  * $Id: fcgi_protocol.c,v 1.21 2001/11/20 01:52:37 robs Exp $
   3  */
   4
   5
   6 #include "fcgi.h"
   7 #include "fcgi_protocol.h"
   8
   9 #ifdef WIN32
  10 #pragma warning( disable : 4706)
  11 #endif
  12
  13  /*******************************************************************************
  14  * Build and queue a FastCGI message header.  It is the caller's
  15  * responsibility to make sure that there's enough space in the buffer, and
  16  * that the data bytes (specified by 'len') are queued immediately following
  17  * this header.
  18  */
  19 static void queue_header(fcgi_request *fr, unsigned char type, unsigned int len)
  20 {
  21     FCGI_Header header;
  22
  23     ap_assert(type > 0);
  24     ap_assert(type <= FCGI_MAXTYPE);
  25     ap_assert(len <= 0xffff);
  26     ap_assert(BufferFree(fr->serverOutputBuffer) >= sizeof(FCGI_Header));
  27
  28     /* Assemble and queue the packet header. */
  29     header.version = FCGI_VERSION;
  30     header.type = type;
  31     header.requestIdB1 = (unsigned char) (fr->requestId >> 8);
  32     header.requestIdB0 = (unsigned char) fr->requestId;
  33     header.contentLengthB1 = (unsigned char) (len / 256);  /* MSB */
  34     header.contentLengthB0 = (unsigned char) (len % 256);  /* LSB */
  35     header.paddingLength = 0;
  36     header.reserved = 0;
  37     fcgi_buf_add_block(fr->serverOutputBuffer, (char *) &header, sizeof(FCGI_Header));
  38 }
  39
  40 /*******************************************************************************
  41  * Build a FCGI_BeginRequest message body.
  42  */
  43 static void build_begin_request(unsigned int role, unsigned char keepConnection,
  44         FCGI_BeginRequestBody *body)
  45 {
  46     ap_assert((role >> 16) == 0);
  47     body->roleB1 = (unsigned char) (role >>  8);
  48     body->roleB0 = (unsigned char) role;
  49     body->flags = (unsigned char) ((keepConnection) ? FCGI_KEEP_CONN : 0);
  50     memset(body->reserved, 0, sizeof(body->reserved));
  51 }
  52
  53 /*******************************************************************************
  54  * Build and queue a FastCGI "Begin Request" message.
  55  */
  56 void fcgi_protocol_queue_begin_request(fcgi_request *fr)
  57 {
  58     FCGI_BeginRequestBody body;
  59     int bodySize = sizeof(FCGI_BeginRequestBody);
  60
  61     /* We should be the first ones to use this buffer */
  62     ap_assert(BufferLength(fr->serverOutputBuffer) == 0);
  63
  64     build_begin_request(fr->role, FALSE, &body);
  65     queue_header(fr, FCGI_BEGIN_REQUEST, bodySize);
  66     fcgi_buf_add_block(fr->serverOutputBuffer, (char *) &body, bodySize);
  67 }
  68
  69 /*******************************************************************************
  70  * Build a FastCGI name-value pair (env) header.
  71  */
  72 static void build_env_header(int nameLen, int valueLen,
  73         unsigned char *headerBuffPtr, int *headerLenPtr)
  74 {
  75     unsigned char *startHeaderBuffPtr = headerBuffPtr;
  76
  77     ap_assert(nameLen >= 0);
  78
  79     if (nameLen < 0x80) {
  80         *headerBuffPtr++ = (unsigned char) nameLen;
  81     } else {
  82         *headerBuffPtr++ = (unsigned char) ((nameLen >> 24) | 0x80);
  83         *headerBuffPtr++ = (unsigned char) (nameLen >> 16);
  84         *headerBuffPtr++ = (unsigned char) (nameLen >> 8);
  85         *headerBuffPtr++ = (unsigned char) nameLen;
  86     }
  87
  88     ap_assert(valueLen >= 0);
  89
  90     if (valueLen < 0x80) {
  91         *headerBuffPtr++ = (unsigned char) valueLen;
  92     } else {
  93         *headerBuffPtr++ = (unsigned char) ((valueLen >> 24) | 0x80);
  94         *headerBuffPtr++ = (unsigned char) (valueLen >> 16);
  95         *headerBuffPtr++ = (unsigned char) (valueLen >> 8);
  96         *headerBuffPtr++ = (unsigned char) valueLen;
  97     }
  98     *headerLenPtr = headerBuffPtr - startHeaderBuffPtr;
  99 }
 100
 101 /* A static fn stolen from Apache's util_script.c...
 102  * Obtain the Request-URI from the original request-line, returning
 103  * a new string from the request pool containing the URI or "".
 104  */
 105 static char *apache_original_uri(request_rec *r)
 106 {
 107     char *first, *last;
 108
 109     if (r->the_request == NULL)
 110         return (char *) ap_pcalloc(r->pool, 1);
 111
 112     first = r->the_request;     /* use the request-line */
 113
 114     while (*first && !ap_isspace(*first))
 115         ++first;                    /* skip over the method */
 116
 117     while (ap_isspace(*first))
 118         ++first;                    /* and the space(s) */
 119
 120     last = first;
 121     while (*last && !ap_isspace(*last))
 122         ++last;                     /* end at next whitespace */
 123
 124     return ap_pstrndup(r->pool, first, last - first);
 125 }
 126
 127 /* Based on Apache's ap_add_cgi_vars() in util_script.c.
 128  * Apache's spins in sub_req_lookup_uri() trying to setup PATH_TRANSLATED,
 129  * so we just don't do that part.
 130  */
 131 static void add_auth_cgi_vars(request_rec *r, const int compat)
 132 {
 133     table *e = r->subprocess_env;
 134
 135     ap_table_setn(e, "GATEWAY_INTERFACE", "CGI/1.1");
 136     ap_table_setn(e, "SERVER_PROTOCOL", r->protocol);
 137     ap_table_setn(e, "REQUEST_METHOD", r->method);
 138     ap_table_setn(e, "QUERY_STRING", r->args ? r->args : "");
 139     ap_table_setn(e, "REQUEST_URI", apache_original_uri(r));
 140
 141     /* The FastCGI spec precludes sending of CONTENT_LENGTH, PATH_INFO,
 142      * PATH_TRANSLATED, and SCRIPT_NAME (for some reason?).  PATH_TRANSLATED we
 143      * don't have, its the variable that causes Apache to break trying to set
 144      * up (and thus the reason this fn exists vs. using ap_add_cgi_vars()). */
 145     if (compat) {
 146         ap_table_unset(e, "CONTENT_LENGTH");
 147         return;
 148     }
 149
 150     /* Note that the code below special-cases scripts run from includes,
 151      * because it "knows" that the sub_request has been hacked to have the
 152      * args and path_info of the original request, and not any that may have
 153      * come with the script URI in the include command.  Ugh. */
 154     if (!strcmp(r->protocol, "INCLUDED")) {
 155         ap_table_setn(e, "SCRIPT_NAME", r->uri);
 156         if (r->path_info && *r->path_info)
 157             ap_table_setn(e, "PATH_INFO", r->path_info);
 158     }
 159     else if (!r->path_info || !*r->path_info)
 160         ap_table_setn(e, "SCRIPT_NAME", r->uri);
 161     else {
 162         int path_info_start = ap_find_path_info(r->uri, r->path_info);
 163
 164         ap_table_setn(e, "SCRIPT_NAME", ap_pstrndup(r->pool, r->uri, path_info_start));
 165         ap_table_setn(e, "PATH_INFO", r->path_info);
 166     }
 167 }
 168
 169 static void add_pass_header_vars(fcgi_request *fr)
 170 {
 171     const array_header *ph = fr->dynamic ? dynamic_pass_headers : fr->fs->pass_headers;
 172
 173     if (ph) {
 174         const char **elt = (const char **)ph->elts;
 175         int i = ph->nelts;
 176
 177         for ( ; i; --i, ++elt) {
 178             const char *val = ap_table_get(fr->r->headers_in, *elt);
 179             if (val) {
 180                 ap_table_setn(fr->r->subprocess_env, *elt, val);
 181             }
 182         }
 183     }
 184 }
 185
 186 /*******************************************************************************
 187  * Build and queue the environment name-value pairs.  Returns TRUE if the
 188  * complete ENV was buffered, FALSE otherwise.  Note: envp is updated to
 189  * reflect the current position in the ENV.
 190  */
 191 int fcgi_protocol_queue_env(request_rec *r, fcgi_request *fr, env_status *env)
 192 {
 193     int charCount;
 194
 195     if (env->envp == NULL) {
 196         ap_add_common_vars(r);
 197         add_pass_header_vars(fr);
 198
 199         if (fr->role == FCGI_RESPONDER)
 200                 ap_add_cgi_vars(r);
 201         else
 202             add_auth_cgi_vars(r, fr->auth_compat);
 203
 204         env->envp = ap_create_environment(r->pool, r->subprocess_env);
 205         env->pass = PREP;
 206     }
 207
 208     while (*env->envp) {
 209         switch (env->pass)
 210         {
 211         case PREP:
 212             env->equalPtr = strchr(*env->envp, '=');
 213             ap_assert(env->equalPtr != NULL);
 214             env->nameLen = env->equalPtr - *env->envp;
 215             env->valueLen = strlen(++env->equalPtr);
 216             build_env_header(env->nameLen, env->valueLen, env->headerBuff, &env->headerLen);
 217             env->totalLen = env->headerLen + env->nameLen + env->valueLen;
 218             env->pass = HEADER;
 219             /* drop through */
 220
 221         case HEADER:
 222             if (BufferFree(fr->serverOutputBuffer) < (int)(sizeof(FCGI_Header) + env->headerLen)) {
 223                 return (FALSE);
 224             }
 225             queue_header(fr, FCGI_PARAMS, env->totalLen);
 226             fcgi_buf_add_block(fr->serverOutputBuffer, (char *)env->headerBuff, env->headerLen);
 227             env->pass = NAME;
 228             /* drop through */
 229
 230         case NAME:
 231             charCount = fcgi_buf_add_block(fr->serverOutputBuffer, *env->envp, env->nameLen);
 232             if (charCount != env->nameLen) {
 233                 *env->envp += charCount;
 234                 env->nameLen -= charCount;
 235                 return (FALSE);
 236             }
 237             env->pass = VALUE;
 238             /* drop through */
 239
 240         case VALUE:
 241             charCount = fcgi_buf_add_block(fr->serverOutputBuffer, env->equalPtr, env->valueLen);
 242             if (charCount != env->valueLen) {
 243                 env->equalPtr += charCount;
 244                 env->valueLen -= charCount;
 245                 return (FALSE);
 246             }
 247             env->pass = PREP;
 248         }
 249         ++env->envp;
 250     }
 251
 252     if (BufferFree(fr->serverOutputBuffer) < sizeof(FCGI_Header)) {
 253         return(FALSE);
 254     }
 255     queue_header(fr, FCGI_PARAMS, 0);
 256     return(TRUE);
 257 }
 258
 259 /*******************************************************************************
 260  * Queue data from the client input buffer to the FastCGI server output
 261  * buffer (encapsulating the data in FastCGI protocol messages).
 262  */
 263 void fcgi_protocol_queue_client_buffer(fcgi_request *fr)
 264 {
 265     int movelen;
 266     int in_len, out_free;
 267
 268     if (fr->eofSent)
 269         return;
 270
 271     /*
 272      * If there's some client data and room for at least one byte
 273      * of data in the output buffer (after protocol overhead), then
 274      * move some data to the output buffer.
 275      */
 276     in_len = BufferLength(fr->clientInputBuffer);
 277     out_free = max(0, BufferFree(fr->serverOutputBuffer) - sizeof(FCGI_Header));
 278     movelen = min(in_len, out_free);
 279     if (movelen > 0) {
 280         queue_header(fr, FCGI_STDIN, movelen);
 281         fcgi_buf_get_to_buf(fr->serverOutputBuffer, fr->clientInputBuffer, movelen);
 282     }
 283
 284     /*
 285      * If all the client data has been sent, and there's room
 286      * in the output buffer, indicate EOF.
 287      */
 288     if (movelen == in_len && fr->expectingClientContent <= 0
 289             && BufferFree(fr->serverOutputBuffer) >= sizeof(FCGI_Header))
 290     {
 291         queue_header(fr, FCGI_STDIN, 0);
 292         fr->eofSent = TRUE;
 293     }
 294 }
 295
 296 /*******************************************************************************
 297  * Read FastCGI protocol messages from the FastCGI server input buffer into
 298  * fr->header when parsing headers, to fr->fs_stderr when reading stderr data,
 299  * or to the client output buffer otherwises.
 300  */
 301 int fcgi_protocol_dequeue(pool *p, fcgi_request *fr)
 302 {
 303     FCGI_Header header;
 304     int len;
 305
 306     while (BufferLength(fr->serverInputBuffer) > 0) {
 307         /*
 308          * State #1:  looking for the next complete packet header.
 309          */
 310         if (fr->gotHeader == FALSE) {
 311             if (BufferLength(fr->serverInputBuffer) < sizeof(FCGI_Header)) {
 312                 return OK;
 313             }
 314             fcgi_buf_get_to_block(fr->serverInputBuffer, (char *) &header,
 315                     sizeof(FCGI_Header));
 316             /*
 317              * XXX: Better handling of packets with other version numbers
 318              * and other packet problems.
 319              */
 320             if (header.version != FCGI_VERSION) {
 321                 ap_log_rerror(FCGI_LOG_ERR_NOERRNO, fr->r,
 322                     "FastCGI: comm with server \"%s\" aborted: protocol error: invalid version: %d != FCGI_VERSION(%d)",
 323                     fr->fs_path, header.version, FCGI_VERSION);
 324                 return SERVER_ERROR;
 325             }
 326             if (header.type > FCGI_MAXTYPE) {
 327                 ap_log_rerror(FCGI_LOG_ERR_NOERRNO, fr->r,
 328                     "FastCGI: comm with server \"%s\" aborted: protocol error: invalid type: %d > FCGI_MAXTYPE(%d)",
 329                     fr->fs_path, header.type, FCGI_MAXTYPE);
 330                 return SERVER_ERROR;
 331             }
 332
 333             fr->packetType = header.type;
 334             fr->dataLen = (header.contentLengthB1 << 8)
 335                     + header.contentLengthB0;
 336             fr->gotHeader = TRUE;
 337             fr->paddingLen = header.paddingLength;
 338         }
 339
 340         /*
 341          * State #2:  got a header, and processing packet bytes.
 342          */
 343         len = min(fr->dataLen, BufferLength(fr->serverInputBuffer));
 344         ap_assert(len >= 0);
 345         switch (fr->packetType) {
 346             case FCGI_STDOUT:
 347                 if (len > 0) {
 348                     switch(fr->parseHeader) {
 349                         case SCAN_CGI_READING_HEADERS:
 350                             fcgi_buf_get_to_array(fr->serverInputBuffer, fr->header, len);
 351                             break;
 352                         case SCAN_CGI_FINISHED:
 353                             len = min(BufferFree(fr->clientOutputBuffer), len);
 354                             if (len > 0) {
 355                                 fcgi_buf_get_to_buf(fr->clientOutputBuffer, fr->serverInputBuffer, len);
 356                             } else {
 357                                 return OK;
 358                             }
 359                             break;
 360                         default:
 361                             /* Toss data on the floor */
 362                             break;
 363                     }
 364                     fr->dataLen -= len;
 365                 }
 366                 break;
 367
 368             case FCGI_STDERR:
 369
 370                 if (fr->fs_stderr == NULL)
 371                 {
 372                     fr->fs_stderr = ap_palloc(p, FCGI_SERVER_MAX_STDERR_LINE_LEN + 1);
 373                 }
 374
 375                 /* We're gonna consume all thats here */
 376                 fr->dataLen -= len;
 377
 378                 while (len > 0)
 379                 {
 380                     char *null, *end, *start = fr->fs_stderr;
 381
 382                     /* Get as much as will fit in the buffer */
 383                     int get_len = min(len, FCGI_SERVER_MAX_STDERR_LINE_LEN - fr->fs_stderr_len);
 384                     fcgi_buf_get_to_block(fr->serverInputBuffer, start + fr->fs_stderr_len, get_len);
 385                     len -= get_len;
 386                     fr->fs_stderr_len += get_len;
 387                     *(start + fr->fs_stderr_len) = '\0';
 388
 389                     /* Disallow nulls, we could be nicer but this is the motivator */
 390                     while ((null = memchr(start, '\0', fr->fs_stderr_len)))
 391                     {
 392                         int discard = ++null - start;
 393                         ap_log_rerror(FCGI_LOG_ERR_NOERRNO, fr->r,
 394                             "FastCGI: server \"%s\" sent a null character in the stderr stream!?, "
 395                             "discarding %d characters of stderr", fr->fs_path, discard);
 396                         start = null;
 397                         fr->fs_stderr_len -= discard;
 398                     }
 399
 400                     /* Print as much as possible  */
 401                     while ((end = strpbrk(start, "\r\n")))
 402                     {
 403                         if (start != end)
 404                         {
 405                                 *end = '\0';
 406                                 ap_log_rerror(FCGI_LOG_ERR_NOERRNO, fr->r, "FastCGI: server \"%s\" stderr: %s", fr->fs_path, start);
 407                         }
 408                         end += strspn(++end, "\r\n");
 409                         fr->fs_stderr_len -= (end - start);
 410                         start = end;
 411                     }
 412
 413                     if (fr->fs_stderr_len)
 414                     {
 415                         if (start != fr->fs_stderr)
 416                         {
 417                             /* Move leftovers down */
 418                             memmove(fr->fs_stderr, start, fr->fs_stderr_len);
 419                         }
 420                         else if (fr->fs_stderr_len == FCGI_SERVER_MAX_STDERR_LINE_LEN)
 421                         {
 422                             /* Full buffer, dump it and complain */
 423                             ap_log_rerror(FCGI_LOG_ERR_NOERRNO, fr->r, "FastCGI: server \"%s\" stderr: %s", fr->fs_path, fr->fs_stderr);
 424                             ap_log_rerror(FCGI_LOG_WARN_NOERRNO, fr->r,
 425                                 "FastCGI: too much stderr received from server \"%s\", "
 426                                 "increase FCGI_SERVER_MAX_STDERR_LINE_LEN (%d) and rebuild "
 427                                 "or use \"\\n\" to terminate lines",
 428                                 fr->fs_path, FCGI_SERVER_MAX_STDERR_LINE_LEN);
 429                             fr->fs_stderr_len = 0;
 430                         }
 431                     }
 432                 }
 433                 break;
 434
 435             case FCGI_END_REQUEST:
 436                 if (!fr->readingEndRequestBody) {
 437                     if (fr->dataLen != sizeof(FCGI_EndRequestBody)) {
 438                         ap_log_rerror(FCGI_LOG_ERR_NOERRNO, fr->r,
 439                             "FastCGI: comm with server \"%s\" aborted: protocol error: invalid FCGI_END_REQUEST size: "
 440                             "%d != sizeof(FCGI_EndRequestBody)(%d)",
 441                             fr->fs_path, fr->dataLen, sizeof(FCGI_EndRequestBody));
 442                         return SERVER_ERROR;
 443                     }
 444                     fr->readingEndRequestBody = TRUE;
 445                 }
 446                 if (len>0) {
 447                     fcgi_buf_get_to_buf(fr->erBufPtr, fr->serverInputBuffer, len);
 448                     fr->dataLen -= len;
 449                 }
 450                 if (fr->dataLen == 0) {
 451                     FCGI_EndRequestBody *erBody = &fr->endRequestBody;
 452                     fcgi_buf_get_to_block(
 453                         fr->erBufPtr, (char *) &fr->endRequestBody,
 454                         sizeof(FCGI_EndRequestBody));
 455                     if (erBody->protocolStatus != FCGI_REQUEST_COMPLETE) {
 456                         /*
 457                          * XXX: What to do with FCGI_OVERLOADED?
 458                          */
 459                         ap_log_rerror(FCGI_LOG_ERR_NOERRNO, fr->r,
 460                             "FastCGI: comm with server \"%s\" aborted: protocol error: invalid FCGI_END_REQUEST status: "
 461                             "%d != FCGI_REQUEST_COMPLETE(%d)", fr->fs_path,
 462                             erBody->protocolStatus, FCGI_REQUEST_COMPLETE);
 463                         return SERVER_ERROR;
 464                     }
 465                     fr->exitStatus = (erBody->appStatusB3 << 24)
 466                         + (erBody->appStatusB2 << 16)
 467                         + (erBody->appStatusB1 <<  8)
 468                         + (erBody->appStatusB0 );
 469                     fr->exitStatusSet = TRUE;
 470                     fr->readingEndRequestBody = FALSE;
 471                 }
 472                 break;
 473             case FCGI_GET_VALUES_RESULT:
 474                 /* XXX coming soon */
 475             case FCGI_UNKNOWN_TYPE:
 476                 /* XXX coming soon */
 477
 478             /*
 479              * XXX Ignore unknown packet types from the FastCGI server.
 480              */
 481             default:
 482                 fcgi_buf_toss(fr->serverInputBuffer, len);
 483                 fr->dataLen -= len;
 484                 break;
 485         } /* switch */
 486
 487         /*
 488          * Discard padding, then start looking for
 489          * the next header.
 490          */
 491         if (fr->dataLen == 0) {
 492             if (fr->paddingLen > 0) {
 493                 len = min(fr->paddingLen,
 494                         BufferLength(fr->serverInputBuffer));
 495                 fcgi_buf_toss(fr->serverInputBuffer, len);
 496                 fr->paddingLen -= len;
 497             }
 498             if (fr->paddingLen == 0) {
 499                 fr->gotHeader = FALSE;
 500             }
 501         }
 502     } /* while */
 503     return OK;
 504 }