fcgi_protocol.c

   1 /*
   2  * $Id: fcgi_protocol.c,v 1.19 2001/03/26 15:23:24 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 && type <= FCGI_MAXTYPE);
  24     ap_assert(len >= 0 && len <= 0xffff);
  25     ap_assert(BufferFree(fr->serverOutputBuffer) >= sizeof(FCGI_Header));
  26
  27     /* Assemble and queue the packet header. */
  28     header.version = FCGI_VERSION;
  29     header.type = type;
  30     header.requestIdB1 = (unsigned char) (fr->requestId >> 8);
  31     header.requestIdB0 = (unsigned char) fr->requestId;
  32     header.contentLengthB1 = (unsigned char) (len / 256);  /* MSB */
  33     header.contentLengthB0 = (unsigned char) (len % 256);  /* LSB */
  34     header.paddingLength = 0;
  35     header.reserved = 0;
  36     fcgi_buf_add_block(fr->serverOutputBuffer, (char *) &header, sizeof(FCGI_Header));
  37 }
  38
  39 /*******************************************************************************
  40  * Build a FCGI_BeginRequest message body.
  41  */
  42 static void build_begin_request(unsigned int role, unsigned char keepConnection,
  43         FCGI_BeginRequestBody *body)
  44 {
  45     ap_assert((role >> 16) == 0);
  46     body->roleB1 = (unsigned char) (role >>  8);
  47     body->roleB0 = (unsigned char) role;
  48     body->flags = (unsigned char) ((keepConnection) ? FCGI_KEEP_CONN : 0);
  49     memset(body->reserved, 0, sizeof(body->reserved));
  50 }
  51
  52 /*******************************************************************************
  53  * Build and queue a FastCGI "Begin Request" message.
  54  */
  55 void fcgi_protocol_queue_begin_request(fcgi_request *fr)
  56 {
  57     FCGI_BeginRequestBody body;
  58     int bodySize = sizeof(FCGI_BeginRequestBody);
  59
  60     /* We should be the first ones to use this buffer */
  61     ap_assert(BufferLength(fr->serverOutputBuffer) == 0);
  62
  63     build_begin_request(fr->role, FALSE, &body);
  64     queue_header(fr, FCGI_BEGIN_REQUEST, bodySize);
  65     fcgi_buf_add_block(fr->serverOutputBuffer, (char *) &body, bodySize);
  66 }
  67
  68 /*******************************************************************************
  69  * Build a FastCGI name-value pair (env) header.
  70  */
  71 static void build_env_header(int nameLen, int valueLen,
  72         unsigned char *headerBuffPtr, int *headerLenPtr)
  73 {
  74     unsigned char *startHeaderBuffPtr = headerBuffPtr;
  75
  76     ap_assert(nameLen >= 0);
  77
  78     if (nameLen < 0x80) {
  79         *headerBuffPtr++ = (unsigned char) nameLen;
  80     } else {
  81         *headerBuffPtr++ = (unsigned char) ((nameLen >> 24) | 0x80);
  82         *headerBuffPtr++ = (unsigned char) (nameLen >> 16);
  83         *headerBuffPtr++ = (unsigned char) (nameLen >> 8);
  84         *headerBuffPtr++ = (unsigned char) nameLen;
  85     }
  86
  87     ap_assert(valueLen >= 0);
  88
  89     if (valueLen < 0x80) {
  90         *headerBuffPtr++ = (unsigned char) valueLen;
  91     } else {
  92         *headerBuffPtr++ = (unsigned char) ((valueLen >> 24) | 0x80);
  93         *headerBuffPtr++ = (unsigned char) (valueLen >> 16);
  94         *headerBuffPtr++ = (unsigned char) (valueLen >> 8);
  95         *headerBuffPtr++ = (unsigned char) valueLen;
  96     }
  97     *headerLenPtr = headerBuffPtr - startHeaderBuffPtr;
  98 }
  99
 100 /* A static fn stolen from Apache's util_script.c...
 101  * Obtain the Request-URI from the original request-line, returning
 102  * a new string from the request pool containing the URI or "".
 103  */
 104 static char *apache_original_uri(request_rec *r)
 105 {
 106     char *first, *last;
 107
 108     if (r->the_request == NULL)
 109         return (char *) ap_pcalloc(r->pool, 1);
 110
 111     first = r->the_request;     /* use the request-line */
 112
 113     while (*first && !ap_isspace(*first))
 114         ++first;                    /* skip over the method */
 115
 116     while (ap_isspace(*first))
 117         ++first;                    /* and the space(s) */
 118
 119     last = first;
 120     while (*last && !ap_isspace(*last))
 121         ++last;                     /* end at next whitespace */
 122
 123     return ap_pstrndup(r->pool, first, last - first);
 124 }
 125
 126 /* Based on Apache's ap_add_cgi_vars() in util_script.c.
 127  * Apache's spins in sub_req_lookup_uri() trying to setup PATH_TRANSLATED,
 128  * so we just don't do that part.
 129  */
 130 static void add_auth_cgi_vars(request_rec *r, const int compat)
 131 {
 132     table *e = r->subprocess_env;
 133
 134     ap_table_setn(e, "GATEWAY_INTERFACE", "CGI/1.1");
 135     ap_table_setn(e, "SERVER_PROTOCOL", r->protocol);
 136     ap_table_setn(e, "REQUEST_METHOD", r->method);
 137     ap_table_setn(e, "QUERY_STRING", r->args ? r->args : "");
 138     ap_table_setn(e, "REQUEST_URI", apache_original_uri(r));
 139
 140     /* The FastCGI spec precludes sending of CONTENT_LENGTH, PATH_INFO,
 141      * PATH_TRANSLATED, and SCRIPT_NAME (for some reason?).  PATH_TRANSLATED we
 142      * don't have, its the variable that causes Apache to break trying to set
 143      * up (and thus the reason this fn exists vs. using ap_add_cgi_vars()). */
 144     if (compat) {
 145         ap_table_unset(e, "CONTENT_LENGTH");
 146         return;
 147     }
 148
 149     /* Note that the code below special-cases scripts run from includes,
 150      * because it "knows" that the sub_request has been hacked to have the
 151      * args and path_info of the original request, and not any that may have
 152      * come with the script URI in the include command.  Ugh. */
 153     if (!strcmp(r->protocol, "INCLUDED")) {
 154         ap_table_setn(e, "SCRIPT_NAME", r->uri);
 155         if (r->path_info && *r->path_info)
 156             ap_table_setn(e, "PATH_INFO", r->path_info);
 157     }
 158     else if (!r->path_info || !*r->path_info)
 159         ap_table_setn(e, "SCRIPT_NAME", r->uri);
 160     else {
 161         int path_info_start = ap_find_path_info(r->uri, r->path_info);
 162
 163         ap_table_setn(e, "SCRIPT_NAME", ap_pstrndup(r->pool, r->uri, path_info_start));
 164         ap_table_setn(e, "PATH_INFO", r->path_info);
 165     }
 166 }
 167
 168 static void add_pass_header_vars(fcgi_request *fr)
 169 {
 170     const array_header *ph = fr->dynamic ? dynamic_pass_headers : fr->fs->pass_headers;
 171
 172     if (ph) {
 173         const char **elt = (const char **)ph->elts;
 174         int i = ph->nelts;
 175
 176         for ( ; i; --i, ++elt) {
 177             const char *val = ap_table_get(fr->r->headers_in, *elt);
 178             if (val) {
 179                 ap_table_setn(fr->r->subprocess_env, *elt, val);
 180             }
 181         }
 182     }
 183 }
 184
 185 /*******************************************************************************
 186  * Build and queue the environment name-value pairs.  Returns TRUE if the
 187  * complete ENV was buffered, FALSE otherwise.  Note: envp is updated to
 188  * reflect the current position in the ENV.
 189  */
 190 int fcgi_protocol_queue_env(request_rec *r, fcgi_request *fr, env_status *env)
 191 {
 192     int charCount;
 193
 194     if (env->envp == NULL) {
 195         ap_add_common_vars(r);
 196         add_pass_header_vars(fr);
 197
 198         if (fr->role == FCGI_RESPONDER)
 199                 ap_add_cgi_vars(r);
 200         else
 201             add_auth_cgi_vars(r, fr->auth_compat);
 202
 203         env->envp = ap_create_environment(r->pool, r->subprocess_env);
 204         env->pass = PREP;
 205     }
 206
 207     while (*env->envp) {
 208         switch (env->pass)
 209         {
 210         case PREP:
 211             env->equalPtr = strchr(*env->envp, '=');
 212             ap_assert(env->equalPtr != NULL);
 213             env->nameLen = env->equalPtr - *env->envp;
 214             env->valueLen = strlen(++env->equalPtr);
 215             build_env_header(env->nameLen, env->valueLen, env->headerBuff, &env->headerLen);
 216             env->totalLen = env->headerLen + env->nameLen + env->valueLen;
 217             env->pass = HEADER;
 218             /* drop through */
 219
 220         case HEADER:
 221             if (BufferFree(fr->serverOutputBuffer) < (int)(sizeof(FCGI_Header) + env->headerLen)) {
 222                 return (FALSE);
 223             }
 224             queue_header(fr, FCGI_PARAMS, env->totalLen);
 225             fcgi_buf_add_block(fr->serverOutputBuffer, (char *)env->headerBuff, env->headerLen);
 226             env->pass = NAME;
 227             /* drop through */
 228
 229         case NAME:
 230             charCount = fcgi_buf_add_block(fr->serverOutputBuffer, *env->envp, env->nameLen);
 231             if (charCount != env->nameLen) {
 232                 *env->envp += charCount;
 233                 env->nameLen -= charCount;
 234                 return (FALSE);
 235             }
 236             env->pass = VALUE;
 237             /* drop through */
 238
 239         case VALUE:
 240             charCount = fcgi_buf_add_block(fr->serverOutputBuffer, env->equalPtr, env->valueLen);
 241             if (charCount != env->valueLen) {
 242                 env->equalPtr += charCount;
 243                 env->valueLen -= charCount;
 244                 return (FALSE);
 245             }
 246             env->pass = PREP;
 247         }
 248         ++env->envp;
 249     }
 250
 251     if (BufferFree(fr->serverOutputBuffer) < sizeof(FCGI_Header)) {
 252         return(FALSE);
 253     }
 254     queue_header(fr, FCGI_PARAMS, 0);
 255     return(TRUE);
 256 }
 257
 258 /*******************************************************************************
 259  * Queue data from the client input buffer to the FastCGI server output
 260  * buffer (encapsulating the data in FastCGI protocol messages).
 261  */
 262 void fcgi_protocol_queue_client_buffer(fcgi_request *fr)
 263 {
 264     int movelen;
 265     int in_len, out_free;
 266
 267     if (fr->eofSent)
 268         return;
 269
 270     /*
 271      * If there's some client data and room for at least one byte
 272      * of data in the output buffer (after protocol overhead), then
 273      * move some data to the output buffer.
 274      */
 275     in_len = BufferLength(fr->clientInputBuffer);
 276     out_free = max(0, BufferFree(fr->serverOutputBuffer) - sizeof(FCGI_Header));
 277     movelen = min(in_len, out_free);
 278     if (movelen > 0) {
 279         queue_header(fr, FCGI_STDIN, movelen);
 280         fcgi_buf_get_to_buf(fr->serverOutputBuffer, fr->clientInputBuffer, movelen);
 281     }
 282
 283     /*
 284      * If all the client data has been sent, and there's room
 285      * in the output buffer, indicate EOF.
 286      */
 287     if (movelen == in_len && fr->expectingClientContent <= 0
 288             && BufferFree(fr->serverOutputBuffer) >= sizeof(FCGI_Header))
 289     {
 290         queue_header(fr, FCGI_STDIN, 0);
 291         fr->eofSent = TRUE;
 292     }
 293 }
 294
 295 /*******************************************************************************
 296  * Read FastCGI protocol messages from the FastCGI server input buffer into
 297  * fr->header when parsing headers, to fr->fs_stderr when reading stderr data,
 298  * or to the client output buffer otherwises.
 299  */
 300 int fcgi_protocol_dequeue(pool *p, fcgi_request *fr)
 301 {
 302     FCGI_Header header;
 303     int len;
 304
 305     while (BufferLength(fr->serverInputBuffer) > 0) {
 306         /*
 307          * State #1:  looking for the next complete packet header.
 308          */
 309         if (fr->gotHeader == FALSE) {
 310             if (BufferLength(fr->serverInputBuffer) < sizeof(FCGI_Header)) {
 311                 return OK;
 312             }
 313             fcgi_buf_get_to_block(fr->serverInputBuffer, (char *) &header,
 314                     sizeof(FCGI_Header));
 315             /*
 316              * XXX: Better handling of packets with other version numbers
 317              * and other packet problems.
 318              */
 319             if (header.version != FCGI_VERSION) {
 320                 ap_log_rerror(FCGI_LOG_ERR_NOERRNO, fr->r,
 321                     "FastCGI: comm with server \"%s\" aborted: protocol error: invalid version: %d != FCGI_VERSION(%d)",
 322                     fr->fs_path, header.version, FCGI_VERSION);
 323                 return SERVER_ERROR;
 324             }
 325             if (header.type > FCGI_MAXTYPE) {
 326                 ap_log_rerror(FCGI_LOG_ERR_NOERRNO, fr->r,
 327                     "FastCGI: comm with server \"%s\" aborted: protocol error: invalid type: %d > FCGI_MAXTYPE(%d)",
 328                     fr->fs_path, header.type, FCGI_MAXTYPE);
 329                 return SERVER_ERROR;
 330             }
 331
 332             fr->packetType = header.type;
 333             fr->dataLen = (header.contentLengthB1 << 8)
 334                     + header.contentLengthB0;
 335             fr->gotHeader = TRUE;
 336             fr->paddingLen = header.paddingLength;
 337         }
 338
 339         /*
 340          * State #2:  got a header, and processing packet bytes.
 341          */
 342         len = min(fr->dataLen, BufferLength(fr->serverInputBuffer));
 343         ap_assert(len >= 0);
 344         switch (fr->packetType) {
 345             case FCGI_STDOUT:
 346                 if (len > 0) {
 347                     switch(fr->parseHeader) {
 348                         case SCAN_CGI_READING_HEADERS:
 349                             fcgi_buf_get_to_array(fr->serverInputBuffer, fr->header, len);
 350                             break;
 351                         case SCAN_CGI_FINISHED:
 352                             len = min(BufferFree(fr->clientOutputBuffer), len);
 353                             if (len > 0) {
 354                                 fcgi_buf_get_to_buf(fr->clientOutputBuffer, fr->serverInputBuffer, len);
 355                             } else {
 356                                 return OK;
 357                             }
 358                             break;
 359                         default:
 360                             /* Toss data on the floor */
 361                             break;
 362                     }
 363                     fr->dataLen -= len;
 364                 }
 365                 break;
 366
 367             case FCGI_STDERR:
 368
 369                 if (fr->fs_stderr == NULL)
 370                 {
 371                     fr->fs_stderr = ap_palloc(p, FCGI_SERVER_MAX_STDERR_LINE_LEN + 1);
 372                 }
 373
 374                 /* We're gonna consume all thats here */
 375                 fr->dataLen -= len;
 376
 377                 while (len > 0)
 378                 {
 379                     char *null, *end, *start = fr->fs_stderr;
 380
 381                     /* Get as much as will fit in the buffer */
 382                     int get_len = min(len, FCGI_SERVER_MAX_STDERR_LINE_LEN - fr->fs_stderr_len);
 383                     fcgi_buf_get_to_block(fr->serverInputBuffer, start + fr->fs_stderr_len, get_len);
 384                     len -= get_len;
 385                     fr->fs_stderr_len += get_len;
 386                     *(start + fr->fs_stderr_len) = '\0';
 387
 388                     /* Disallow nulls, we could be nicer but this is the motivator */
 389                     while ((null = memchr(start, '\0', fr->fs_stderr_len)))
 390                     {
 391                         int discard = ++null - start;
 392                         ap_log_rerror(FCGI_LOG_ERR_NOERRNO, fr->r,
 393                             "FastCGI: server \"%s\" sent a null character in the stderr stream!?, "
 394                             "discarding %d characters of stderr", fr->fs_path, discard);
 395                         start = null;
 396                         fr->fs_stderr_len -= discard;
 397                     }
 398
 399                     /* Print as much as possible  */
 400                     while ((end = strpbrk(start, "\r\n")))
 401                     {
 402                         if (start != end)
 403                         {
 404                                 *end = '\0';
 405                                 ap_log_rerror(FCGI_LOG_ERR_NOERRNO, fr->r, "FastCGI: server \"%s\" stderr: %s", fr->fs_path, start);
 406                         }
 407                         end += strspn(++end, "\r\n");
 408                         fr->fs_stderr_len -= (end - start);
 409                         start = end;
 410                     }
 411
 412                     if (fr->fs_stderr_len)
 413                     {
 414                         if (start != fr->fs_stderr)
 415                         {
 416                             /* Move leftovers down */
 417                             memmove(fr->fs_stderr, start, fr->fs_stderr_len);
 418                         }
 419                         else if (fr->fs_stderr_len == FCGI_SERVER_MAX_STDERR_LINE_LEN)
 420                         {
 421                             /* Full buffer, dump it and complain */
 422                             ap_log_rerror(FCGI_LOG_ERR_NOERRNO, fr->r, "FastCGI: server \"%s\" stderr: %s", fr->fs_path, fr->fs_stderr);
 423                             ap_log_rerror(FCGI_LOG_WARN_NOERRNO, fr->r,
 424                                 "FastCGI: too much stderr received from server \"%s\", "
 425                                 "increase FCGI_SERVER_MAX_STDERR_LINE_LEN (%d) and rebuild "
 426                                 "or use \"\\n\" to terminate lines",
 427                                 fr->fs_path, FCGI_SERVER_MAX_STDERR_LINE_LEN);
 428                             fr->fs_stderr_len = 0;
 429                         }
 430                     }
 431                 }
 432                 break;
 433
 434             case FCGI_END_REQUEST:
 435                 if (!fr->readingEndRequestBody) {
 436                     if (fr->dataLen != sizeof(FCGI_EndRequestBody)) {
 437                         ap_log_rerror(FCGI_LOG_ERR_NOERRNO, fr->r,
 438                             "FastCGI: comm with server \"%s\" aborted: protocol error: invalid FCGI_END_REQUEST size: "
 439                             "%d != sizeof(FCGI_EndRequestBody)(%d)",
 440                             fr->fs_path, fr->dataLen, sizeof(FCGI_EndRequestBody));
 441                         return SERVER_ERROR;
 442                     }
 443                     fr->readingEndRequestBody = TRUE;
 444                 }
 445                 if (len>0) {
 446                     fcgi_buf_get_to_buf(fr->erBufPtr, fr->serverInputBuffer, len);
 447                     fr->dataLen -= len;
 448                 }
 449                 if (fr->dataLen == 0) {
 450                     FCGI_EndRequestBody *erBody = &fr->endRequestBody;
 451                     fcgi_buf_get_to_block(
 452                         fr->erBufPtr, (char *) &fr->endRequestBody,
 453                         sizeof(FCGI_EndRequestBody));
 454                     if (erBody->protocolStatus != FCGI_REQUEST_COMPLETE) {
 455                         /*
 456                          * XXX: What to do with FCGI_OVERLOADED?
 457                          */
 458                         ap_log_rerror(FCGI_LOG_ERR_NOERRNO, fr->r,
 459                             "FastCGI: comm with server \"%s\" aborted: protocol error: invalid FCGI_END_REQUEST status: "
 460                             "%d != FCGI_REQUEST_COMPLETE(%d)", fr->fs_path,
 461                             erBody->protocolStatus, FCGI_REQUEST_COMPLETE);
 462                         return SERVER_ERROR;
 463                     }
 464                     fr->exitStatus = (erBody->appStatusB3 << 24)
 465                         + (erBody->appStatusB2 << 16)
 466                         + (erBody->appStatusB1 <<  8)
 467                         + (erBody->appStatusB0 );
 468                     fr->exitStatusSet = TRUE;
 469                     fr->readingEndRequestBody = FALSE;
 470                 }
 471                 break;
 472             case FCGI_GET_VALUES_RESULT:
 473                 /* XXX coming soon */
 474             case FCGI_UNKNOWN_TYPE:
 475                 /* XXX coming soon */
 476
 477             /*
 478              * XXX Ignore unknown packet types from the FastCGI server.
 479              */
 480             default:
 481                 fcgi_buf_toss(fr->serverInputBuffer, len);
 482                 fr->dataLen -= len;
 483                 break;
 484         } /* switch */
 485
 486         /*
 487          * Discard padding, then start looking for
 488          * the next header.
 489          */
 490         if (fr->dataLen == 0) {
 491             if (fr->paddingLen > 0) {
 492                 len = min(fr->paddingLen,
 493                         BufferLength(fr->serverInputBuffer));
 494                 fcgi_buf_toss(fr->serverInputBuffer, len);
 495                 fr->paddingLen -= len;
 496             }
 497             if (fr->paddingLen == 0) {
 498                 fr->gotHeader = FALSE;
 499             }
 500         }
 501     } /* while */
 502     return OK;
 503 }