/* * Copyright (c) 2013 Joris Vink * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include #include #include #include "spdy.h" #include "kore.h" #include "http.h" static char *http_status_text(int); static int http_post_data_recv(struct netbuf *); static TAILQ_HEAD(, http_request) http_requests; static struct kore_pool http_request_pool; static struct kore_pool http_header_pool; int http_request_count; u_int64_t http_hsts_enable = HTTP_HSTS_ENABLE; u_int16_t http_header_max = HTTP_HEADER_MAX_LEN; u_int16_t http_keepalive_time = HTTP_KEEPALIVE_TIME; u_int64_t http_postbody_max = HTTP_POSTBODY_MAX_LEN; void http_init(void) { http_request_count = 0; TAILQ_INIT(&http_requests); kore_pool_init(&http_request_pool, "http_request_pool", sizeof(struct http_request), worker_max_connections); kore_pool_init(&http_header_pool, "http_header_pool", sizeof(struct http_header), worker_max_connections * HTTP_REQ_HEADER_MAX); } int http_request_new(struct connection *c, struct spdy_stream *s, char *host, char *method, char *path, struct http_request **out) { struct http_request *req; kore_debug("http_request_new(%p, %p, %s, %s, %s)", c, s, host, method, path); if (strlen(host) >= KORE_DOMAINNAME_LEN - 1) return (KORE_RESULT_ERROR); if (strlen(path) >= HTTP_URI_LEN - 1) return (KORE_RESULT_ERROR); req = kore_pool_get(&http_request_pool); req->end = 0; req->start = 0; req->flags = 0; req->owner = c; req->status = 0; req->stream = s; req->post_data = NULL; req->hdlr_extra = NULL; req->multipart_body = NULL; kore_strlcpy(req->host, host, sizeof(req->host)); kore_strlcpy(req->path, path, sizeof(req->path)); TAILQ_INIT(&(req->resp_headers)); TAILQ_INIT(&(req->req_headers)); TAILQ_INIT(&(req->arguments)); TAILQ_INIT(&(req->files)); if (!strcasecmp(method, "get")) { req->method = HTTP_METHOD_GET; req->flags |= HTTP_REQUEST_COMPLETE; } else if (!strcasecmp(method, "post")) { req->method = HTTP_METHOD_POST; } else { kore_debug("invalid method specified in request: %s", method); http_request_free(req); return (KORE_RESULT_ERROR); } if (s != NULL) { if (!http_request_header_get(req, "user-agent", &(req->agent))) req->agent = kore_strdup("unknown"); } else { req->agent = NULL; } if (out != NULL) *out = req; http_request_count++; TAILQ_INSERT_TAIL(&http_requests, req, list); TAILQ_INSERT_TAIL(&(c->http_requests), req, olist); return (KORE_RESULT_OK); } void http_process(void) { struct http_request *req, *next; struct kore_module_handle *hdlr; int r, (*cb)(struct http_request *); for (req = TAILQ_FIRST(&http_requests); req != NULL; req = next) { next = TAILQ_NEXT(req, list); if (req->flags & HTTP_REQUEST_DELETE) { TAILQ_REMOVE(&http_requests, req, list); http_request_free(req); http_request_count--; continue; } if (!(req->flags & HTTP_REQUEST_COMPLETE)) continue; hdlr = kore_module_handler_find(req->host, req->path); req->start = kore_time_ms(); if (hdlr == NULL) { r = http_generic_404(req); } else { cb = hdlr->addr; worker->active_hdlr = hdlr; r = cb(req); worker->active_hdlr = NULL; } req->end = kore_time_ms(); switch (r) { case KORE_RESULT_OK: r = net_send_flush(req->owner); if (r == KORE_RESULT_ERROR) kore_connection_disconnect(req->owner); break; case KORE_RESULT_ERROR: kore_connection_disconnect(req->owner); break; case KORE_RESULT_RETRY: break; } if (r != KORE_RESULT_RETRY) { kore_accesslog(req); TAILQ_REMOVE(&http_requests, req, list); http_request_free(req); http_request_count--; } } } void http_response_header_add(struct http_request *req, char *header, char *value) { struct http_header *hdr; kore_debug("http_response_header_add(%p, %s, %s)", req, header, value); hdr = kore_pool_get(&http_header_pool); hdr->header = kore_strdup(header); hdr->value = kore_strdup(value); TAILQ_INSERT_TAIL(&(req->resp_headers), hdr, list); } void http_request_free(struct http_request *req) { struct http_file *f, *fnext; struct http_arg *q, *qnext; struct http_header *hdr, *next; TAILQ_REMOVE(&(req->owner->http_requests), req, olist); for (hdr = TAILQ_FIRST(&(req->resp_headers)); hdr != NULL; hdr = next) { next = TAILQ_NEXT(hdr, list); TAILQ_REMOVE(&(req->resp_headers), hdr, list); kore_mem_free(hdr->header); kore_mem_free(hdr->value); kore_pool_put(&http_header_pool, hdr); } for (hdr = TAILQ_FIRST(&(req->req_headers)); hdr != NULL; hdr = next) { next = TAILQ_NEXT(hdr, list); TAILQ_REMOVE(&(req->req_headers), hdr, list); kore_mem_free(hdr->header); kore_mem_free(hdr->value); kore_pool_put(&http_header_pool, hdr); } for (q = TAILQ_FIRST(&(req->arguments)); q != NULL; q = qnext) { qnext = TAILQ_NEXT(q, list); TAILQ_REMOVE(&(req->arguments), q, list); kore_mem_free(q->name); if (q->value != NULL) kore_mem_free(q->value); kore_mem_free(q); } for (f = TAILQ_FIRST(&(req->files)); f != NULL; f = fnext) { fnext = TAILQ_NEXT(f, list); TAILQ_REMOVE(&(req->files), f, list); kore_mem_free(f->filename); kore_mem_free(f->name); kore_mem_free(f); } if (req->method == HTTP_METHOD_POST && req->post_data != NULL) kore_buf_free(req->post_data); if (req->method == HTTP_METHOD_POST && req->multipart_body != NULL) kore_mem_free(req->multipart_body); if (req->agent != NULL) kore_mem_free(req->agent); if (req->hdlr_extra != NULL) kore_mem_free(req->hdlr_extra); kore_pool_put(&http_request_pool, req); } int http_response(struct http_request *req, int status, u_int8_t *d, u_int32_t len) { u_int32_t hlen; struct http_header *hdr; struct kore_buf *buf; u_int8_t *htext; struct spdy_header_block *hblock; char sbuf[512]; kore_debug("http_response(%p, %d, %p, %d)", req, status, d, len); req->status = status; if (req->owner->proto == CONN_PROTO_SPDY) { snprintf(sbuf, sizeof(sbuf), "%d %s", status, http_status_text(status)); hblock = spdy_header_block_create(SPDY_HBLOCK_NORMAL); spdy_header_block_add(hblock, ":status", sbuf); spdy_header_block_add(hblock, ":version", "HTTP/1.1"); spdy_header_block_add(hblock, ":server", KORE_NAME_STRING); if (http_hsts_enable) { snprintf(sbuf, sizeof(sbuf), "max-age=%" PRIu64, http_hsts_enable); spdy_header_block_add(hblock, ":strict-transport-security", sbuf); } TAILQ_FOREACH(hdr, &(req->resp_headers), list) spdy_header_block_add(hblock, hdr->header, hdr->value); htext = spdy_header_block_release(req->owner, hblock, &hlen); if (htext == NULL) { spdy_session_teardown(req->owner, SPDY_SESSION_ERROR_INTERNAL); return (KORE_RESULT_OK); } spdy_frame_send(req->owner, SPDY_CTRL_FRAME_SYN_REPLY, 0, hlen, req->stream, 0); net_send_queue(req->owner, htext, hlen); kore_mem_free(htext); if (len > 0) { spdy_frame_send(req->owner, SPDY_DATA_FRAME, 0, len, req->stream, 0); net_send_queue(req->owner, d, len); spdy_update_wsize(req->owner, req->stream, len); } spdy_frame_send(req->owner, SPDY_DATA_FRAME, FLAG_FIN, 0, req->stream, 0); } else { buf = kore_buf_create(KORE_BUF_INITIAL); kore_buf_appendf(buf, "HTTP/1.1 %d %s\r\n", status, http_status_text(status)); kore_buf_appendf(buf, "Content-length: %d\r\n", len); kore_buf_appendf(buf, "Server: %s\r\n", KORE_NAME_STRING); if (http_keepalive_time) { kore_buf_appendf(buf, "Connection: keep-alive\r\n"); kore_buf_appendf(buf, "Keep-Alive: timeout=%d\r\n", http_keepalive_time); } else { kore_buf_appendf(buf, "Connection: close\r\n"); } if (http_hsts_enable) { kore_buf_appendf(buf, "Strict-Transport-Security: "); kore_buf_appendf(buf, "max-age=%" PRIu64 "\r\n", http_hsts_enable); } TAILQ_FOREACH(hdr, &(req->resp_headers), list) { kore_buf_appendf(buf, "%s: %s\r\n", hdr->header, hdr->value); } kore_buf_append(buf, "\r\n", 2); htext = kore_buf_release(buf, &hlen); net_send_queue(req->owner, htext, hlen); kore_mem_free(htext); net_send_queue(req->owner, d, len); net_recv_queue(req->owner, http_header_max, NETBUF_CALL_CB_ALWAYS, NULL, http_header_recv); } return (KORE_RESULT_OK); } int http_request_header_get(struct http_request *req, char *header, char **out) { int r; struct http_header *hdr; if (req->owner->proto == CONN_PROTO_SPDY) { r = spdy_stream_get_header(req->stream->hblock, header, out); } else { TAILQ_FOREACH(hdr, &(req->req_headers), list) { if (!strcasecmp(hdr->header, header)) { r = strlen(hdr->value) + 1; *out = kore_malloc(r); kore_strlcpy(*out, hdr->value, r); return (KORE_RESULT_OK); } } r = KORE_RESULT_ERROR; } return (r); } int http_header_recv(struct netbuf *nb) { size_t len; u_int64_t clen; struct http_header *hdr; struct http_request *req; struct netbuf *nnb; u_int8_t *end_headers; int h, i, v, skip, bytes_left; char *request[4], *host[3], *hbuf; char *p, *headers[HTTP_REQ_HEADER_MAX]; struct connection *c = (struct connection *)nb->owner; kore_debug("http_header_recv(%p)", nb); if (nb->len < 4) return (KORE_RESULT_OK); end_headers = kore_mem_find(nb->buf, nb->offset, "\r\n\r\n", 4); if (end_headers == NULL) return (KORE_RESULT_OK); *end_headers = '\0'; end_headers += 4; nb->flags |= NETBUF_FORCE_REMOVE; len = end_headers - nb->buf; hbuf = (char *)nb->buf; h = kore_split_string(hbuf, "\r\n", headers, HTTP_REQ_HEADER_MAX); if (h < 2) return (KORE_RESULT_ERROR); if ((strlen(headers[0]) > 3 && strncasecmp(headers[0], "get", 3)) && (strlen(headers[0]) > 4 && strncasecmp(headers[0], "post", 4))) return (KORE_RESULT_ERROR); v = kore_split_string(headers[0], " ", request, 4); if (v != 3) return (KORE_RESULT_ERROR); host[0] = NULL; for (i = 0; i < h; i++) { if (strncasecmp(headers[i], "host", MIN(strlen(headers[i]), strlen("host")))) continue; v = kore_split_string(headers[i], ":", host, 3); if (v != 2) return (KORE_RESULT_ERROR); if (strlen(host[0]) != 4 || strncasecmp(host[0], "host", 4) || strlen(host[1]) < 4) return (KORE_RESULT_ERROR); host[1]++; skip = i; break; } if (host[0] == NULL) return (KORE_RESULT_ERROR); if (!http_request_new(c, NULL, host[1], request[0], request[1], &req)) return (KORE_RESULT_ERROR); for (i = 1; i < h; i++) { if (i == skip) continue; p = strchr(headers[i], ':'); if (p == NULL) { kore_debug("malformed header: '%s'", headers[i]); continue; } *(p++) = '\0'; if (*p == ' ') p++; hdr = kore_pool_get(&http_header_pool); hdr->header = kore_strdup(headers[i]); hdr->value = kore_strdup(p); TAILQ_INSERT_TAIL(&(req->req_headers), hdr, list); if (req->agent == NULL && !strcasecmp(hdr->header, "user-agent")) req->agent = kore_strdup(hdr->value); } if (req->method == HTTP_METHOD_POST) { if (!http_request_header_get(req, "content-length", &p)) { kore_debug("POST but no content-length"); req->flags |= HTTP_REQUEST_DELETE; return (KORE_RESULT_ERROR); } clen = kore_strtonum(p, 10, 0, ULONG_MAX, &v); if (v == KORE_RESULT_ERROR) { kore_mem_free(p); kore_debug("content-length invalid: %s", p); req->flags |= HTTP_REQUEST_DELETE; return (KORE_RESULT_ERROR); } kore_mem_free(p); if (clen > http_postbody_max) { kore_log(LOG_NOTICE, "POST data too large (%ld > %ld)", clen, http_postbody_max); req->flags |= HTTP_REQUEST_DELETE; return (KORE_RESULT_ERROR); } req->post_data = kore_buf_create(clen); kore_buf_append(req->post_data, end_headers, (nb->offset - len)); bytes_left = clen - (nb->offset - len); if (bytes_left > 0) { kore_debug("%ld/%ld (%ld - %ld) more bytes for POST", bytes_left, clen, nb->offset, len); net_recv_queue(c, bytes_left, 0, &nnb, http_post_data_recv); nnb->extra = req; } else if (bytes_left == 0) { req->flags |= HTTP_REQUEST_COMPLETE; } else { kore_debug("bytes_left would become zero (%ld)", clen); return (KORE_RESULT_ERROR); } } return (KORE_RESULT_OK); } int http_populate_arguments(struct http_request *req) { u_int32_t len; int i, v, c, count; char *query, *args[HTTP_MAX_QUERY_ARGS], *val[3]; if (req->method == HTTP_METHOD_POST) { query = http_post_data_text(req); } else { kore_debug("HTTP_METHOD_GET not supported for arguments"); return (0); } count = 0; v = kore_split_string(query, "&", args, HTTP_MAX_QUERY_ARGS); for (i = 0; i < v; i++) { c = kore_split_string(args[i], "=", val, 3); if (c != 1 && c != 2) { kore_debug("malformed query argument"); continue; } if (val[1] == NULL) len = 0; else len = strlen(val[1]); http_argument_add(req, val[0], val[1], len); count++; } kore_mem_free(query); return (count); } int http_argument_lookup(struct http_request *req, const char *name, char **out) { struct http_arg *q; TAILQ_FOREACH(q, &(req->arguments), list) { if (!strcmp(q->name, name)) { if (q->value == NULL) return (KORE_RESULT_ERROR); *out = kore_strdup(q->value); return (KORE_RESULT_OK); } } return (KORE_RESULT_ERROR); } int http_argument_urldecode(char *arg) { u_int8_t v; int err; size_t len; char *p, *in, h[5]; p = arg; in = arg; len = strlen(arg); while (*p != '\0' && p < (arg + len)) { if (*p == '+') *p = ' '; if (*p != '%') { *in++ = *p++; continue; } if ((p + 2) >= (arg + len)) { kore_debug("overflow in '%s'", arg); return (KORE_RESULT_ERROR); } if (!isxdigit(*(p + 1)) || !isxdigit(*(p + 2))) { *in++ = *p++; continue; } h[0] = '0'; h[1] = 'x'; h[2] = *(p + 1); h[3] = *(p + 2); h[4] = '\0'; v = kore_strtonum(h, 16, 0, 255, &err); if (err != KORE_RESULT_OK) return (err); *in++ = (char)v; p += 3; } *in = '\0'; return (KORE_RESULT_OK); } int http_argument_multiple_lookup(struct http_request *req, struct http_arg *args) { int i, c; c = 0; for (i = 0; args[i].name != NULL; i++) { if (!http_argument_lookup(req, args[i].name, &(args[i].value))) { args[i].value = NULL; } else { c++; } } return (c); } void http_argument_multiple_free(struct http_arg *args) { int i; for (i = 0; args[i].name != NULL; i++) { if (args[i].value != NULL) kore_mem_free(args[i].value); } } void http_argument_add(struct http_request *req, char *name, char *value, u_int32_t len) { struct http_arg *q; q = kore_malloc(sizeof(struct http_arg)); q->name = kore_strdup(name); if (len > 0) { q->value = kore_malloc(len + 1); kore_strlcpy(q->value, value, len + 1); } else { q->value = NULL; } TAILQ_INSERT_TAIL(&(req->arguments), q, list); } void http_file_add(struct http_request *req, char *name, char *filename, u_int8_t *data, u_int32_t len) { struct http_file *f; f = kore_malloc(sizeof(struct http_file)); f->len = len; f->data = data; f->name = kore_strdup(name); f->filename = kore_strdup(filename); TAILQ_INSERT_TAIL(&(req->files), f, list); } int http_file_lookup(struct http_request *req, char *name, char **fname, u_int8_t **data, u_int32_t *len) { struct http_file *f; TAILQ_FOREACH(f, &(req->files), list) { if (!strcmp(f->name, name)) { *len = f->len; *data = f->data; *fname = f->filename; return (KORE_RESULT_OK); } } return (KORE_RESULT_ERROR); } int http_populate_multipart_form(struct http_request *req, int *v) { int h, i, c; u_int32_t blen, slen, len; u_int8_t *s, *end, *e, *end_headers, *data; char *d, *val, *type, *boundary, *fname; char *headers[5], *args[5], *opt[5], *name; *v = 0; if (req->method != HTTP_METHOD_POST) return (KORE_RESULT_ERROR); if (!http_request_header_get(req, "content-type", &type)) return (KORE_RESULT_ERROR); h = kore_split_string(type, ";", args, 3); if (h != 2) { kore_mem_free(type); return (KORE_RESULT_ERROR); } if (strcasecmp(args[0], "multipart/form-data")) { kore_mem_free(type); return (KORE_RESULT_ERROR); } if ((val = strchr(args[1], '=')) == NULL) { kore_mem_free(type); return (KORE_RESULT_ERROR); } val++; slen = strlen(val); boundary = kore_malloc(slen + 3); snprintf(boundary, slen + 3, "--%s", val); slen = strlen(boundary); kore_mem_free(type); req->multipart_body = http_post_data_bytes(req, &blen); if (slen < 3 || blen < (slen * 2)) { kore_mem_free(boundary); return (KORE_RESULT_ERROR); } end = req->multipart_body + blen - 2; if (end < req->multipart_body || (end - 2) < req->multipart_body) { kore_mem_free(boundary); return (KORE_RESULT_ERROR); } if (memcmp((end - slen - 2), boundary, slen) || memcmp((end - 2), "--", 2)) { kore_mem_free(boundary); return (KORE_RESULT_ERROR); } s = req->multipart_body + slen + 2; while (s < end) { e = kore_mem_find(s, end - s, boundary, slen); if (e == NULL) { kore_mem_free(boundary); return (KORE_RESULT_ERROR); } *(e - 2) = '\0'; end_headers = kore_mem_find(s, (e - 2) - s, "\r\n\r\n", 4); if (end_headers == NULL) { kore_mem_free(boundary); return (KORE_RESULT_ERROR); } *end_headers = '\0'; data = end_headers + 4; h = kore_split_string((char *)s, "\r\n", headers, 5); for (i = 0; i < h; i++) { c = kore_split_string(headers[i], ":", args, 5); if (c != 2) continue; /* Ignore other headers for now. */ if (strcasecmp(args[0], "content-disposition")) continue; for (d = args[1]; isspace(*d); d++) ; c = kore_split_string(d, ";", opt, 5); if (strcasecmp(opt[0], "form-data")) continue; if ((val = strchr(opt[1], '=')) == NULL) continue; if (strlen(val) < 3) continue; val++; kore_strip_chars(val, '"', &name); if (opt[2] == NULL) { *v = *v + 1; http_argument_add(req, name, (char *)data, (e - 2) - data); kore_mem_free(name); continue; } for (d = opt[2]; isspace(*d); d++) ; len = MIN(strlen("filename="), strlen(d)); if (!strncasecmp(d, "filename=", len)) { if ((val = strchr(d, '=')) == NULL) { kore_mem_free(name); continue; } val++; kore_strip_chars(val, '"', &fname); if (strlen(fname) > 0) { *v = *v + 1; http_file_add(req, name, fname, data, (e - 2) - data); } kore_mem_free(fname); } else { kore_debug("got unknown: %s", opt[2]); } kore_mem_free(name); } s = e + slen + 2; } kore_mem_free(boundary); return (KORE_RESULT_OK); } char * http_post_data_text(struct http_request *req) { u_int32_t len; u_int8_t *data; char *text; data = kore_buf_release(req->post_data, &len); req->post_data = NULL; len++; text = kore_malloc(len); kore_strlcpy(text, (char *)data, len); kore_mem_free(data); return (text); } u_int8_t * http_post_data_bytes(struct http_request *req, u_int32_t *len) { u_int8_t *data; data = kore_buf_release(req->post_data, len); req->post_data = NULL; return (data); } int http_generic_404(struct http_request *req) { kore_debug("http_generic_404(%s, %d, %s)", req->host, req->method, req->path); return (http_response(req, 404, NULL, 0)); } static int http_post_data_recv(struct netbuf *nb) { struct http_request *req = (struct http_request *)nb->extra; kore_buf_append(req->post_data, nb->buf, nb->offset); req->flags |= HTTP_REQUEST_COMPLETE; kore_debug("post complete for request %p", req); return (KORE_RESULT_OK); } static char * http_status_text(int status) { char *r; switch (status) { case HTTP_STATUS_CONTINUE: r = "Continue"; break; case HTTP_STATUS_SWITCHING_PROTOCOLS: r = "Switching Protocols"; break; case HTTP_STATUS_OK: r = "OK"; break; case HTTP_STATUS_CREATED: r = "Created"; break; case HTTP_STATUS_ACCEPTED: r = "Accepted"; break; case HTTP_STATUS_NON_AUTHORITATIVE: r = "Non-Authoritative Information"; break; case HTTP_STATUS_NO_CONTENT: r = "No Content"; break; case HTTP_STATUS_RESET_CONTENT: r = "Reset Content"; break; case HTTP_STATUS_PARTIAL_CONTENT: r = "Partial Content"; break; case HTTP_STATUS_MULTIPLE_CHOICES: r = "Multiple Choices"; break; case HTTP_STATUS_MOVED_PERMANENTLY: r = "Moved Permanently"; break; case HTTP_STATUS_FOUND: r = "Found"; break; case HTTP_STATUS_SEE_OTHER: r = "See Other"; break; case HTTP_STATUS_NOT_MODIFIED: r = "Not Modified"; break; case HTTP_STATUS_USE_PROXY: r = "Use Proxy"; break; case HTTP_STATUS_TEMPORARY_REDIRECT: r = "Temporary Redirect"; break; case HTTP_STATUS_BAD_REQUEST: r = "Bad Request"; break; case HTTP_STATUS_UNAUTHORIZED: r = "Unauthorized"; break; case HTTP_STATUS_PAYMENT_REQUIRED: r = "Payment Required"; break; case HTTP_STATUS_FORBIDDEN: r = "Forbidden"; break; case HTTP_STATUS_NOT_FOUND: r = "Not Found"; break; case HTTP_STATUS_METHOD_NOT_ALLOWED: r = "Method Not Allowed"; break; case HTTP_STATUS_NOT_ACCEPTABLE: r = "Not Acceptable"; break; case HTTP_STATUS_PROXY_AUTH_REQUIRED: r = "Proxy Authentication Required"; break; case HTTP_STATUS_REQUEST_TIMEOUT: r = "Request Time-out"; break; case HTTP_STATUS_CONFLICT: r = "Conflict"; break; case HTTP_STATUS_GONE: r = "Gone"; break; case HTTP_STATUS_LENGTH_REQUIRED: r = "Length Required"; break; case HTTP_STATUS_PRECONDITION_FAILED: r = "Precondition Failed"; break; case HTTP_STATUS_REQUEST_ENTITY_TOO_LARGE: r = "Request Entity Too Large"; break; case HTTP_STATUS_REQUEST_URI_TOO_LARGE: r = "Request-URI Too Large"; break; case HTTP_STATUS_UNSUPPORTED_MEDIA_TYPE: r = "Unsupported Media Type"; break; case HTTP_STATUS_REQUEST_RANGE_INVALID: r = "Requested range not satisfiable"; break; case HTTP_STATUS_EXPECTATION_FAILED: r = "Expectation Failed"; break; case HTTP_STATUS_INTERNAL_ERROR: r = "Internal Server Error"; break; case HTTP_STATUS_NOT_IMPLEMENTED: r = "Not Implemented"; break; case HTTP_STATUS_BAD_GATEWAY: r = "Bad Gateway"; break; case HTTP_STATUS_SERVICE_UNAVAILABLE: r = "Service Unavailable"; break; case HTTP_STATUS_GATEWAY_TIMEOUT: r = "Gateway Time-out"; break; case HTTP_STATUS_BAD_VERSION: r = "HTTP Version not supported"; break; default: r = ""; break; } return (r); }