1 files changed, 159 insertions, 0 deletions
diff --git a/contrib/impcap/http_parser.c b/contrib/impcap/http_parser.c
new file mode 100644
index 0000000..56d8a25
--- /dev/null
+++ b/contrib/impcap/http_parser.c
@@ -0,0 +1,159 @@
+/* http_parser.c
+ *
+ * This file contains functions to parse HTTP headers.
+ *
+ * File begun on 2018-11-13
+ *
+ * Created by:
+ *  - Théo Bertin (theo.bertin@advens.fr)
+ *
+ * With:
+ *  - François Bernard (francois.bernard@isen.yncrea.fr)
+ *  - Tianyu Geng (tianyu.geng@isen.yncrea.fr)
+ *
+ * This file is part of rsyslog.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *       -or-
+ *       see COPYING.ASL20 in the source distribution
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "config.h"
+#include "parsers.h"
+
+static const char *keywords[] = {
+		"OPTIONS",
+		"GET",
+		"HEAD",
+		"POST",
+		"PUT",
+		"DELETE",
+		"TRACE",
+		"CONNECT",
+		"HTTP",
+		NULL
+};
+
+static inline char *string_split(char **initString, const char *delimiterString) {
+	char *ret = *initString;
+
+	if (*initString) {
+		char *pos = strstr(*initString, delimiterString);
+		if (pos) {
+			*initString = pos;
+			**initString = '\0';
+			*initString += strlen(delimiterString);
+		} else {
+			*initString = NULL;
+		}
+	}
+
+	return ret;
+}
+
+static inline int has_status_keyword(char *http) {
+	const char *found;
+	int i;
+
+	for (i = 0; keywords[i] != NULL; i++) {
+		found = strstr(http, keywords[i]);
+		if (found && (found - http) < 20) {
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ *  This function catches HTTP header fields and status line
+ *  and adds them to the provided json object
+*/
+static inline void catch_status_and_fields(char *header, struct json_object *jparent) {
+	DBGPRINTF("catch_status_and_fields\n");
+
+	struct json_object *fields = json_object_new_object();
+
+	char *statusLine = string_split(&header, "\r\n");
+	char *firstPart, *secondPart, *thirdPart;
+	firstPart = string_split(&statusLine, " ");
+	secondPart = string_split(&statusLine, " ");
+	thirdPart = statusLine;
+	if (firstPart && secondPart && thirdPart) {
+		if (strstr(firstPart, "HTTP")) {
+			json_object_object_add(jparent, "HTTP_version", json_object_new_string(firstPart));
+			json_object_object_add(jparent, "HTTP_status_code", json_object_new_string(secondPart));
+			json_object_object_add(jparent, "HTTP_reason", json_object_new_string(thirdPart));
+		} else {
+			json_object_object_add(jparent, "HTTP_method", json_object_new_string(firstPart));
+			json_object_object_add(jparent, "HTTP_request_URI", json_object_new_string(secondPart));
+			json_object_object_add(jparent, "HTTP_version", json_object_new_string(thirdPart));
+		}
+	}
+
+	char *fieldValue = string_split(&header, "\r\n");
+	char *field, *value;
+	while (fieldValue) {
+		field = string_split(&fieldValue, ":");
+		value = fieldValue;
+		if (value) {
+			while (*value == ' ') { value++; }
+			DBGPRINTF("got header field -> '%s': '%s'\n", field, value);
+			json_object_object_add(fields, field, json_object_new_string(value));
+		}
+
+		fieldValue = string_split(&header, "\r\n");
+	}
+
+	json_object_object_add(jparent, "HTTP_header_fields", fields);
+
+	return;
+}
+
+/*
+ *  This function parses the bytes in the received packet to extract HTTP metadata.
+ *
+ *  its parameters are:
+ *    - a pointer on the list of bytes representing the packet
+ *        the beginning of the header will be checked by the function
+ *    - the size of the list passed as first parameter
+ *    - a pointer on a json_object, containing all the metadata recovered so far
+ *      this is also where HTTP metadata will be added
+ *
+ *  This function returns a structure containing the data unprocessed by this parser
+ *  or the ones after (as a list of bytes), and the length of this data.
+*/
+data_ret_t *http_parse(const uchar *packet, int pktSize, struct json_object *jparent) {
+	DBGPRINTF("http_parse\n");
+	DBGPRINTF("packet size %d\n", pktSize);
+	if (pktSize < 6) {
+		RETURN_DATA_AFTER(0)
+	}
+
+	char *pHttp = malloc(pktSize + 1);
+	char *http = pHttp;
+	memcpy(http, packet, pktSize);
+	*(http + pktSize) = '\0';
+
+	if (!has_status_keyword(http)) {
+		free(pHttp);
+		RETURN_DATA_AFTER(0)
+	}
+
+	char *header = string_split(&http, "\r\n\r\n");
+
+	catch_status_and_fields(header, jparent);
+
+	free(pHttp);
+	RETURN_DATA_AFTER(0)
+}