fcgi_protocol.c

   1 /*
   2  * $Id: fcgi_protocol.c,v 1.14 2000/04/27 02:27:35 robs Exp $
   3  */
   4
   5
   6 #include "fcgi.h"
   7 #include "fcgi_protocol.h"
   8
   9  /*******************************************************************************
  10  * Build and queue a FastCGI message header.  It is the caller's
  11  * responsibility to make sure that there's enough space in the buffer, and
  12  * that the data bytes (specified by 'len') are queued immediately following
  13  * this header.
  14  */
  15 static void queue_header(fcgi_request *fr, int type, int len)
  16 {
  17     FCGI_Header header;
  18
  19     ap_assert(type > 0 && type <= FCGI_MAXTYPE);
  20     ap_assert(len >= 0 && len <= 0xffff);
  21     ap_assert(BufferFree(fr->serverOutputBuffer) > sizeof(FCGI_Header));
  22
  23     /* Assemble and queue the packet header. */
  24     header.version = FCGI_VERSION;
  25     header.type = type;
  26     header.requestIdB1 = (fr->requestId >> 8) & 0xff;
  27     header.requestIdB0 = (fr->requestId) & 0xff;
  28     header.contentLengthB1 = len/256;  /* MSB */
  29     header.contentLengthB0 = len%256;  /* LSB */
  30     header.paddingLength = 0;
  31     header.reserved = 0;
  32     fcgi_buf_add_block(fr->serverOutputBuffer, (char *) &header, sizeof(FCGI_Header));
  33 }
  34
  35 /*******************************************************************************
  36  * Build a FCGI_BeginRequest message body.
  37  */
  38 static void build_begin_request(int role, int keepConnection,
  39         FCGI_BeginRequestBody *body)
  40 {
  41     ap_assert((role >> 16) == 0);
  42     body->roleB1 = (role >>  8) & 0xff;
  43     body->roleB0 = (role      ) & 0xff;
  44     body->flags = (keepConnection) ? FCGI_KEEP_CONN : 0;
  45     memset(body->reserved, 0, sizeof(body->reserved));
  46 }
  47
  48 /*******************************************************************************
  49  * Build and queue a FastCGI "Begin Request" message.
  50  */
  51 void fcgi_protocol_queue_begin_request(fcgi_request *fr)
  52 {
  53     FCGI_BeginRequestBody body;
  54     int bodySize = sizeof(FCGI_BeginRequestBody);
  55
  56     /* We should be the first ones to use this buffer */
  57     ap_assert(BufferLength(fr->serverOutputBuffer) == 0);
  58
  59     build_begin_request(fr->role, FALSE, &body);
  60     queue_header(fr, FCGI_BEGIN_REQUEST, bodySize);
  61     fcgi_buf_add_block(fr->serverOutputBuffer, (char *) &body, bodySize);
  62 }
  63
  64 /*******************************************************************************
  65  * Build a FastCGI name-value pair (env) header.
  66  */
  67 static void build_env_header(int nameLen, int valueLen,
  68         unsigned char *headerBuffPtr, int *headerLenPtr)
  69 {
  70     unsigned char *startHeaderBuffPtr = headerBuffPtr;
  71
  72     ap_assert(nameLen >= 0);
  73     if(nameLen < 0x80) {
  74         *headerBuffPtr++ = nameLen;
  75     } else {
  76         *headerBuffPtr++ = (nameLen >> 24) | 0x80;
  77         *headerBuffPtr++ = (nameLen >> 16);
  78         *headerBuffPtr++ = (nameLen >> 8);
  79         *headerBuffPtr++ = nameLen;
  80     }
  81     ap_assert(valueLen >= 0);
  82     if(valueLen < 0x80) {
  83         *headerBuffPtr++ = valueLen;
  84     } else {
  85         *headerBuffPtr++ = (valueLen >> 24) | 0x80;
  86         *headerBuffPtr++ = (valueLen >> 16);
  87         *headerBuffPtr++ = (valueLen >> 8);
  88         *headerBuffPtr++ = valueLen;
  89     }
  90     *headerLenPtr = headerBuffPtr - startHeaderBuffPtr;
  91 }
  92
  93 /* A static fn stolen from Apache's util_script.c...
  94  * Obtain the Request-URI from the original request-line, returning
  95  * a new string from the request pool containing the URI or "".
  96  */
  97 static char *apache_original_uri(request_rec *r)
  98 {
  99     char *first, *last;
 100
 101     if (r->the_request == NULL)
 102         return (char *) ap_pcalloc(r->pool, 1);
 103
 104     first = r->the_request;     /* use the request-line */
 105
 106     while (*first && !ap_isspace(*first))
 107         ++first;                    /* skip over the method */
 108
 109     while (ap_isspace(*first))
 110         ++first;                    /* and the space(s) */
 111
 112     last = first;
 113     while (*last && !ap_isspace(*last))
 114         ++last;                     /* end at next whitespace */
 115
 116     return ap_pstrndup(r->pool, first, last - first);
 117 }
 118
 119 /* Based on Apache's ap_add_cgi_vars() in util_script.c.
 120  * Apache's spins in sub_req_lookup_uri() trying to setup PATH_TRANSLATED,
 121  * so we just don't do that part.
 122  */
 123 static void add_auth_cgi_vars(request_rec *r, const int compat)
 124 {
 125     table *e = r->subprocess_env;
 126
 127     ap_table_setn(e, "GATEWAY_INTERFACE", "CGI/1.1");
 128     ap_table_setn(e, "SERVER_PROTOCOL", r->protocol);
 129     ap_table_setn(e, "REQUEST_METHOD", r->method);
 130     ap_table_setn(e, "QUERY_STRING", r->args ? r->args : "");
 131     ap_table_setn(e, "REQUEST_URI", apache_original_uri(r));
 132
 133     /* The FastCGI spec precludes sending of CONTENT_LENGTH, PATH_INFO,
 134      * PATH_TRANSLATED, and SCRIPT_NAME (for some reason?).  PATH_TRANSLATED we
 135      * don't have, its the variable that causes Apache to break trying to set
 136      * up (and thus the reason this fn exists vs. using ap_add_cgi_vars()). */
 137     if (compat) {
 138         ap_table_unset(e, "CONTENT_LENGTH");
 139         return;
 140     }
 141
 142     /* Note that the code below special-cases scripts run from includes,
 143      * because it "knows" that the sub_request has been hacked to have the
 144      * args and path_info of the original request, and not any that may have
 145      * come with the script URI in the include command.  Ugh. */
 146     if (!strcmp(r->protocol, "INCLUDED")) {
 147         ap_table_setn(e, "SCRIPT_NAME", r->uri);
 148         if (r->path_info && *r->path_info)
 149             ap_table_setn(e, "PATH_INFO", r->path_info);
 150     }
 151     else if (!r->path_info || !*r->path_info)
 152         ap_table_setn(e, "SCRIPT_NAME", r->uri);
 153     else {
 154         int path_info_start = ap_find_path_info(r->uri, r->path_info);
 155
 156         ap_table_setn(e, "SCRIPT_NAME", ap_pstrndup(r->pool, r->uri, path_info_start));
 157         ap_table_setn(e, "PATH_INFO", r->path_info);
 158     }
 159 }
 160
 161 static void add_pass_header_vars(fcgi_request *fr)
 162 {
 163     const array_header *ph = fr->dynamic ? dynamic_pass_headers : fr->fs->pass_headers;
 164
 165     if (ph) {
 166         const char **elt = (const char **)ph->elts;
 167         int i = ph->nelts;
 168
 169         for ( ; i; --i, ++elt) {
 170             const char *val = ap_table_get(fr->r->headers_in, *elt);
 171             if (val) {
 172                 ap_table_setn(fr->r->subprocess_env, *elt, val);
 173             }
 174         }
 175     }
 176 }
 177
 178 /*******************************************************************************
 179  * Build and queue the environment name-value pairs.  Returns TRUE if the
 180  * complete ENV was buffered, FALSE otherwise.  Note: envp is updated to
 181  * reflect the current position in the ENV.
 182  */
 183 int fcgi_protocol_queue_env(request_rec *r, fcgi_request *fr, env_status *env)
 184 {
 185     int charCount;
 186
 187     if (env->envp == NULL) {
 188         ap_add_common_vars(r);
 189         add_pass_header_vars(fr);
 190
 191         if (fr->role == FCGI_RESPONDER)
 192                 ap_add_cgi_vars(r);
 193         else
 194             add_auth_cgi_vars(r, fr->auth_compat);
 195
 196         env->envp = ap_create_environment(r->pool, r->subprocess_env);
 197         env->pass = prep;
 198     }
 199
 200     while (**env->envp) {
 201         switch (env->pass)
 202         {
 203         case prep:
 204             env->equalPtr = strchr(*env->envp, '=');
 205             ap_assert(env->equalPtr != NULL);
 206             env->nameLen = env->equalPtr - *env->envp;
 207             env->valueLen = strlen(++env->equalPtr);
 208             build_env_header(env->nameLen, env->valueLen, env->headerBuff, &env->headerLen);
 209             env->totalLen = env->headerLen + env->nameLen + env->valueLen;
 210             env->pass = header;
 211             /* drop through */
 212
 213         case header:
 214             if (BufferFree(fr->serverOutputBuffer) < (int)(sizeof(FCGI_Header) + env->headerLen)) {
 215                 return (FALSE);
 216             }
 217             queue_header(fr, FCGI_PARAMS, env->totalLen);
 218             fcgi_buf_add_block(fr->serverOutputBuffer, (char *)env->headerBuff, env->headerLen);
 219             env->pass = name;
 220             /* drop through */
 221
 222         case name:
 223             charCount = fcgi_buf_add_block(fr->serverOutputBuffer, *env->envp, env->nameLen);
 224             if (charCount != env->nameLen) {
 225                 **env->envp += charCount;
 226                 env->nameLen -= charCount;
 227                 return (FALSE);
 228             }
 229             env->pass = value;
 230             /* drop through */
 231
 232         case value:
 233             charCount = fcgi_buf_add_block(fr->serverOutputBuffer, env->equalPtr, env->valueLen);
 234             if (charCount != env->valueLen) {
 235                 env->equalPtr += charCount;
 236                 env->valueLen -= charCount;
 237                 return (FALSE);
 238             }
 239             env->pass = prep;
 240         }
 241         (*env->envp)++;
 242     }
 243
 244     if (BufferFree(fr->serverOutputBuffer) < sizeof(FCGI_Header)) {
 245         return(FALSE);
 246     }
 247     queue_header(fr, FCGI_PARAMS, 0);
 248     return(TRUE);
 249 }
 250
 251 /*******************************************************************************
 252  * Queue data from the client input buffer to the FastCGI server output
 253  * buffer (encapsulating the data in FastCGI protocol messages).
 254  */
 255 void fcgi_protocol_queue_client_buffer(fcgi_request *fr)
 256 {
 257     int movelen;
 258     int in_len, out_free;
 259
 260     if (fr->eofSent)
 261         return;
 262
 263     /*
 264      * If there's some client data and room for at least one byte
 265      * of data in the output buffer (after protocol overhead), then
 266      * move some data to the output buffer.
 267      */
 268     in_len = BufferLength(fr->clientInputBuffer);
 269     out_free = max(0, BufferFree(fr->serverOutputBuffer) - sizeof(FCGI_Header));
 270     movelen = min(in_len, out_free);
 271     if (movelen > 0) {
 272         queue_header(fr, FCGI_STDIN, movelen);
 273         fcgi_buf_get_to_buf(fr->serverOutputBuffer, fr->clientInputBuffer, movelen);
 274     }
 275
 276     /*
 277      * If all the client data has been sent, and there's room
 278      * in the output buffer, indicate EOF.
 279      */
 280     if (movelen == in_len && fr->expectingClientContent <= 0
 281             && BufferFree(fr->serverOutputBuffer) >= sizeof(FCGI_Header))
 282     {
 283         queue_header(fr, FCGI_STDIN, 0);
 284         fr->eofSent = TRUE;
 285     }
 286 }
 287
 288 /*******************************************************************************
 289  * Read FastCGI protocol messages from the FastCGI server input buffer into
 290  * fr->header when parsing headers, to fr->fs_stderr when reading stderr data,
 291  * or to the client output buffer otherwises.
 292  */
 293 int fcgi_protocol_dequeue(pool *p, fcgi_request *fr)
 294 {
 295     FCGI_Header header;
 296     int len;
 297
 298     while (BufferLength(fr->serverInputBuffer) > 0) {
 299         /*
 300          * State #1:  looking for the next complete packet header.
 301          */
 302         if (fr->gotHeader == FALSE) {
 303             if (BufferLength(fr->serverInputBuffer) < sizeof(FCGI_Header)) {
 304                 return OK;
 305             }
 306             fcgi_buf_get_to_block(fr->serverInputBuffer, (char *) &header,
 307                     sizeof(FCGI_Header));
 308             /*
 309              * XXX: Better handling of packets with other version numbers
 310              * and other packet problems.
 311              */
 312             if (header.version != FCGI_VERSION) {
 313                 ap_log_rerror(FCGI_LOG_ERR_NOERRNO, fr->r,
 314                     "FastCGI: comm with server \"%s\" aborted: protocol error: invalid version: %d != FCGI_VERSION(%d)",
 315                     fr->fs_path, header.version, FCGI_VERSION);
 316                 return SERVER_ERROR;
 317             }
 318             if (header.type > FCGI_MAXTYPE) {
 319                 ap_log_rerror(FCGI_LOG_ERR_NOERRNO, fr->r,
 320                     "FastCGI: comm with server \"%s\" aborted: protocol error: invalid type: %d > FCGI_MAXTYPE(%d)",
 321                     fr->fs_path, header.type, FCGI_MAXTYPE);
 322                 return SERVER_ERROR;
 323             }
 324
 325             fr->packetType = header.type;
 326             fr->dataLen = (header.contentLengthB1 << 8)
 327                     + header.contentLengthB0;
 328             fr->gotHeader = TRUE;
 329             fr->paddingLen = header.paddingLength;
 330         }
 331
 332         /*
 333          * State #2:  got a header, and processing packet bytes.
 334          */
 335         len = min(fr->dataLen, BufferLength(fr->serverInputBuffer));
 336         ap_assert(len >= 0);
 337         switch (fr->packetType) {
 338             case FCGI_STDOUT:
 339                 if (len > 0) {
 340                     switch(fr->parseHeader) {
 341                         case SCAN_CGI_READING_HEADERS:
 342                             fcgi_buf_get_to_array(fr->serverInputBuffer, fr->header, len);
 343                             break;
 344                         case SCAN_CGI_FINISHED:
 345                             len = min(BufferFree(fr->clientOutputBuffer), len);
 346                             if (len > 0) {
 347                                 fcgi_buf_get_to_buf(fr->clientOutputBuffer, fr->serverInputBuffer, len);
 348                             } else {
 349                                 return OK;
 350                             }
 351                             break;
 352                         default:
 353                             /* Toss data on the floor */
 354                             break;
 355                     }
 356                     fr->dataLen -= len;
 357                 }
 358                 break;
 359
 360             case FCGI_STDERR:
 361
 362                 if (fr->fs_stderr == NULL)
 363                 {
 364                     fr->fs_stderr = ap_palloc(p, FCGI_SERVER_MAX_STDERR_LINE_LEN + 1);
 365                 }
 366
 367                 /* We're gonna consume all thats here */
 368                 fr->dataLen -= len;
 369
 370                 while (len > 0)
 371                 {
 372                     char *null, *end, *start = fr->fs_stderr;
 373
 374                     /* Get as much as will fit in the buffer */
 375                     int get_len = min(len, FCGI_SERVER_MAX_STDERR_LINE_LEN - fr->fs_stderr_len);
 376                     fcgi_buf_get_to_block(fr->serverInputBuffer, start + fr->fs_stderr_len, get_len);
 377                     len -= get_len;
 378                     fr->fs_stderr_len += get_len;
 379                     *(start + fr->fs_stderr_len) = '\0';
 380
 381                     /* Disallow nulls, we could be nicer but this is the motivator */
 382                     while ((null = memchr(start, '\0', fr->fs_stderr_len)))
 383                     {
 384                         int discard = ++null - start;
 385                         ap_log_rerror(FCGI_LOG_ERR_NOERRNO, fr->r,
 386                             "FastCGI: server \"%s\" sent a null character in the stderr stream!?, "
 387                             "discarding %d characters of stderr", fr->fs_path, discard);
 388                         start = null;
 389                         fr->fs_stderr_len -= discard;
 390                     }
 391
 392                     /* Print as much as possible  */
 393                     while ((end = strpbrk(start, "\r\n")))
 394                     {
 395                         if (start != end)
 396                         {
 397                                 *end = '\0';
 398                                 ap_log_rerror(FCGI_LOG_ERR_NOERRNO, fr->r, "FastCGI: server \"%s\" stderr: %s", fr->fs_path, start);
 399                         }
 400                         end += strspn(++end, "\r\n");
 401                         fr->fs_stderr_len -= (end - start);
 402                         start = end;
 403                     }
 404
 405                     if (fr->fs_stderr_len)
 406                     {
 407                         if (start != fr->fs_stderr)
 408                         {
 409                             /* Move leftovers down */
 410                             memmove(fr->fs_stderr, start, fr->fs_stderr_len);
 411                         }
 412                         else if (fr->fs_stderr_len == FCGI_SERVER_MAX_STDERR_LINE_LEN)
 413                         {
 414                             /* Full buffer, dump it and complain */
 415                             ap_log_rerror(FCGI_LOG_ERR_NOERRNO, fr->r, "FastCGI: server \"%s\" stderr: %s", fr->fs_path, fr->fs_stderr);
 416                             ap_log_rerror(FCGI_LOG_WARN_NOERRNO, fr->r,
 417                                 "FastCGI: too much stderr received from server \"%s\", "
 418                                 "increase FCGI_SERVER_MAX_STDERR_LINE_LEN (%d) and rebuild "
 419                                 "or use \"\\n\" to terminate lines",
 420                                 fr->fs_path, FCGI_SERVER_MAX_STDERR_LINE_LEN);
 421                             fr->fs_stderr_len = 0;
 422                         }
 423                     }
 424                 }
 425                 break;
 426
 427             case FCGI_END_REQUEST:
 428                 if (!fr->readingEndRequestBody) {
 429                     if (fr->dataLen != sizeof(FCGI_EndRequestBody)) {
 430                         ap_log_rerror(FCGI_LOG_ERR_NOERRNO, fr->r,
 431                             "FastCGI: comm with server \"%s\" aborted: protocol error: invalid FCGI_END_REQUEST size: "
 432                             "%d != sizeof(FCGI_EndRequestBody)(%d)",
 433                             fr->fs_path, fr->dataLen, sizeof(FCGI_EndRequestBody));
 434                         return SERVER_ERROR;
 435                     }
 436                     fr->readingEndRequestBody = TRUE;
 437                 }
 438                 if (len>0) {
 439                     fcgi_buf_get_to_buf(fr->erBufPtr, fr->serverInputBuffer, len);
 440                     fr->dataLen -= len;
 441                 }
 442                 if (fr->dataLen == 0) {
 443                     FCGI_EndRequestBody *erBody = &fr->endRequestBody;
 444                     fcgi_buf_get_to_block(
 445                         fr->erBufPtr, (char *) &fr->endRequestBody,
 446                         sizeof(FCGI_EndRequestBody));
 447                     if (erBody->protocolStatus != FCGI_REQUEST_COMPLETE) {
 448                         /*
 449                          * XXX: What to do with FCGI_OVERLOADED?
 450                          */
 451                         ap_log_rerror(FCGI_LOG_ERR_NOERRNO, fr->r,
 452                             "FastCGI: comm with server \"%s\" aborted: protocol error: invalid FCGI_END_REQUEST status: "
 453                             "%d != FCGI_REQUEST_COMPLETE(%d)", fr->fs_path,
 454                             erBody->protocolStatus, FCGI_REQUEST_COMPLETE);
 455                         return SERVER_ERROR;
 456                     }
 457                     fr->exitStatus = (erBody->appStatusB3 << 24)
 458                         + (erBody->appStatusB2 << 16)
 459                         + (erBody->appStatusB1 <<  8)
 460                         + (erBody->appStatusB0 );
 461                     fr->exitStatusSet = TRUE;
 462                     fr->readingEndRequestBody = FALSE;
 463                 }
 464                 break;
 465             case FCGI_GET_VALUES_RESULT:
 466                 /* XXX coming soon */
 467             case FCGI_UNKNOWN_TYPE:
 468                 /* XXX coming soon */
 469
 470             /*
 471              * XXX Ignore unknown packet types from the FastCGI server.
 472              */
 473             default:
 474                 fcgi_buf_toss(fr->serverInputBuffer, len);
 475                 fr->dataLen -= len;
 476                 break;
 477         } /* switch */
 478
 479         /*
 480          * Discard padding, then start looking for
 481          * the next header.
 482          */
 483         if (fr->dataLen == 0) {
 484             if (fr->paddingLen > 0) {
 485                 len = min(fr->paddingLen,
 486                         BufferLength(fr->serverInputBuffer));
 487                 fcgi_buf_toss(fr->serverInputBuffer, len);
 488                 fr->paddingLen -= len;
 489             }
 490             if (fr->paddingLen == 0) {
 491                 fr->gotHeader = FALSE;
 492             }
 493         }
 494     } /* while */
 495     return OK;
 496 }