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Diffstat (limited to 'src/detect-http-start.c')
| -rw-r--r-- | src/detect-http-start.c | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/src/detect-http-start.c b/src/detect-http-start.c new file mode 100644 index 0000000..fed1abc --- /dev/null +++ b/src/detect-http-start.c @@ -0,0 +1,213 @@ +/* Copyright (C) 2007-2021 Open Information Security Foundation + * + * You can copy, redistribute or modify this Program under the terms of + * the GNU General Public License version 2 as published by the Free + * Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * version 2 along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +/** + * \ingroup httplayer + * + * @{ + */ + +/** + * \file + * + * \author Victor Julien <victor@inliniac.net> + * + * Implements http_start + */ + +#include "suricata-common.h" +#include "threads.h" +#include "decode.h" + +#include "detect.h" +#include "detect-parse.h" +#include "detect-engine.h" +#include "detect-engine-mpm.h" +#include "detect-engine-state.h" +#include "detect-engine-prefilter.h" +#include "detect-engine-content-inspection.h" +#include "detect-content.h" +#include "detect-pcre.h" +#include "detect-http-header-common.h" +#include "detect-http-start.h" + +#include "flow.h" +#include "flow-var.h" +#include "flow-util.h" + +#include "util-debug.h" +#include "util-unittest.h" +#include "util-unittest-helper.h" +#include "util-spm.h" +#include "util-print.h" + +#include "app-layer.h" +#include "app-layer-parser.h" + +#include "app-layer-htp.h" +#include "detect-http-header.h" +#include "stream-tcp.h" + +#define KEYWORD_NAME "http.start" +#define KEYWORD_NAME_LEGACY "http_start" +#define KEYWORD_DOC "http-keywords.html#http-start" +#define BUFFER_NAME "http_start" +#define BUFFER_DESC "http start: request/response line + headers" +static int g_buffer_id = 0; +static int g_keyword_thread_id = 0; + +#define BUFFER_SIZE_STEP 2048 +static HttpHeaderThreadDataConfig g_td_config = { BUFFER_SIZE_STEP }; + +static uint8_t *GetBufferForTX( + htp_tx_t *tx, DetectEngineThreadCtx *det_ctx, Flow *f, uint8_t flags, uint32_t *buffer_len) +{ + *buffer_len = 0; + + HttpHeaderThreadData *hdr_td = NULL; + HttpHeaderBuffer *buf = + HttpHeaderGetBufferSpace(det_ctx, f, flags, g_keyword_thread_id, &hdr_td); + if (unlikely(buf == NULL)) { + return NULL; + } + + bstr *line = NULL; + htp_table_t *headers; + if (flags & STREAM_TOSERVER) { + if (AppLayerParserGetStateProgress(IPPROTO_TCP, ALPROTO_HTTP1, tx, flags) <= + HTP_REQUEST_HEADERS) + return NULL; + line = tx->request_line; + headers = tx->request_headers; + } else { + if (AppLayerParserGetStateProgress(IPPROTO_TCP, ALPROTO_HTTP1, tx, flags) <= + HTP_RESPONSE_HEADERS) + return NULL; + headers = tx->response_headers; + line = tx->response_line; + } + if (line == NULL || headers == NULL) + return NULL; + + size_t line_size = bstr_len(line) + 2; + if (line_size + buf->len > buf->size) { + if (HttpHeaderExpandBuffer(hdr_td, buf, line_size) != 0) { + return NULL; + } + } + memcpy(buf->buffer + buf->len, bstr_ptr(line), bstr_size(line)); + buf->len += bstr_size(line); + buf->buffer[buf->len++] = '\r'; + buf->buffer[buf->len++] = '\n'; + + size_t i = 0; + size_t no_of_headers = htp_table_size(headers); + for (; i < no_of_headers; i++) { + htp_header_t *h = htp_table_get_index(headers, i, NULL); + size_t size1 = bstr_size(h->name); + size_t size2 = bstr_size(h->value); + size_t size = size1 + size2 + 4; + if (i + 1 == no_of_headers) + size += 2; + if (size + buf->len > buf->size) { + if (HttpHeaderExpandBuffer(hdr_td, buf, size) != 0) { + return NULL; + } + } + + memcpy(buf->buffer + buf->len, bstr_ptr(h->name), bstr_size(h->name)); + buf->len += bstr_size(h->name); + buf->buffer[buf->len++] = ':'; + buf->buffer[buf->len++] = ' '; + memcpy(buf->buffer + buf->len, bstr_ptr(h->value), bstr_size(h->value)); + buf->len += bstr_size(h->value); + buf->buffer[buf->len++] = '\r'; + buf->buffer[buf->len++] = '\n'; + if (i + 1 == no_of_headers) { + buf->buffer[buf->len++] = '\r'; + buf->buffer[buf->len++] = '\n'; + } + } + + *buffer_len = buf->len; + return buf->buffer; +} + +static InspectionBuffer *GetBuffer1ForTX(DetectEngineThreadCtx *det_ctx, + const DetectEngineTransforms *transforms, Flow *f, const uint8_t flow_flags, void *txv, + const int list_id) +{ + InspectionBuffer *buffer = InspectionBufferGet(det_ctx, list_id); + if (buffer->inspect == NULL) { + uint32_t rawdata_len = 0; + uint8_t *rawdata = GetBufferForTX(txv, det_ctx, f, flow_flags, &rawdata_len); + if (rawdata_len == 0) + return NULL; + + InspectionBufferSetup(det_ctx, list_id, buffer, rawdata, rawdata_len); + InspectionBufferApplyTransforms(buffer, transforms); + } + + return buffer; +} + +static int DetectHttpStartSetup(DetectEngineCtx *de_ctx, Signature *s, const char *arg) +{ + if (DetectBufferSetActiveList(de_ctx, s, g_buffer_id) < 0) + return -1; + + if (DetectSignatureSetAppProto(s, ALPROTO_HTTP1) < 0) + return -1; + + return 0; +} + +/** + * \brief Registers the keyword handlers for the "http_start" keyword. + */ +void DetectHttpStartRegister(void) +{ + sigmatch_table[DETECT_AL_HTTP_START].name = KEYWORD_NAME; + sigmatch_table[DETECT_AL_HTTP_START].alias = KEYWORD_NAME_LEGACY; + sigmatch_table[DETECT_AL_HTTP_START].desc = BUFFER_NAME " sticky buffer"; + sigmatch_table[DETECT_AL_HTTP_START].url = "/rules/" KEYWORD_DOC; + sigmatch_table[DETECT_AL_HTTP_START].Setup = DetectHttpStartSetup; + sigmatch_table[DETECT_AL_HTTP_START].flags |= SIGMATCH_NOOPT|SIGMATCH_INFO_STICKY_BUFFER; + + DetectAppLayerMpmRegister2(BUFFER_NAME, SIG_FLAG_TOSERVER, 2, PrefilterGenericMpmRegister, + GetBuffer1ForTX, ALPROTO_HTTP1, HTP_REQUEST_HEADERS); + DetectAppLayerMpmRegister2(BUFFER_NAME, SIG_FLAG_TOCLIENT, 2, PrefilterGenericMpmRegister, + GetBuffer1ForTX, ALPROTO_HTTP1, HTP_RESPONSE_HEADERS); + + DetectAppLayerInspectEngineRegister2(BUFFER_NAME, ALPROTO_HTTP1, SIG_FLAG_TOSERVER, + HTP_REQUEST_HEADERS, DetectEngineInspectBufferGeneric, GetBuffer1ForTX); + DetectAppLayerInspectEngineRegister2(BUFFER_NAME, ALPROTO_HTTP1, SIG_FLAG_TOCLIENT, + HTP_RESPONSE_HEADERS, DetectEngineInspectBufferGeneric, GetBuffer1ForTX); + + DetectBufferTypeSetDescriptionByName(BUFFER_NAME, + BUFFER_DESC); + + g_buffer_id = DetectBufferTypeGetByName(BUFFER_NAME); + + g_keyword_thread_id = DetectRegisterThreadCtxGlobalFuncs(KEYWORD_NAME, + HttpHeaderThreadDataInit, &g_td_config, HttpHeaderThreadDataFree); + + SCLogDebug("keyword %s registered. Thread id %d. " + "Buffer %s registered. Buffer id %d", + KEYWORD_NAME, g_keyword_thread_id, + BUFFER_NAME, g_buffer_id); +} |