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Diffstat (limited to 'contrib/impcap/smb_parser.c')
| -rw-r--r-- | contrib/impcap/smb_parser.c | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/contrib/impcap/smb_parser.c b/contrib/impcap/smb_parser.c new file mode 100644 index 0000000..e673cd3 --- /dev/null +++ b/contrib/impcap/smb_parser.c @@ -0,0 +1,145 @@ +/* smb_parser.c + * + * This file contains functions to parse SMB (version 2 and 3) 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" + +/* SMB2 opCodes */ +#define SMB2_NEGOTIATE 0x00 +#define SMB2_SESSIONSET 0x01 +#define SMB2_SESSIONLOGOFF 0x02 +#define SMB2_TREECONNECT 0x03 +#define SMB2_TREEDISCONNECT 0x04 +#define SMB2_CREATE 0x05 +#define SMB2_CLOSE 0x06 +#define SMB2_FLUSH 0x07 +#define SMB2_READ 0x08 +#define SMB2_WRITE 0x09 +#define SMB2_LOCK 0x0a +#define SMB2_IOCTL 0x0b +#define SMB2_CANCEL 0x0c +#define SMB2_KEEPALIVE 0x0d +#define SMB2_FIND 0x0e +#define SMB2_NOTIFY 0x0f +#define SMB2_GETINFO 0x10 +#define SMB2_SETINFO 0x11 +#define SMB2_BREAK 0x12 + +struct smb_header_s { + uint32_t version; + uint16_t headerLength; + uint16_t padding1; + uint32_t ntStatus; + uint16_t opCode; + uint16_t padding2; + uint32_t flags; + uint32_t chainOffset; + uint32_t comSeqNumber[2]; + uint32_t processID; + uint32_t treeID; + uint32_t userID[2]; + uint32_t signature[4]; +}; + +typedef struct smb_header_s smb_header_t; + +static char flagCodes[5] = "RPCS"; + +/* + * This function parses the bytes in the received packet to extract SMB2 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 SMB2 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 *smb_parse(const uchar *packet, int pktSize, struct json_object *jparent) { + DBGPRINTF("smb_parse\n"); + DBGPRINTF("packet size %d\n", pktSize); + + int pktSizeCpy = pktSize; + const uchar *packetCpy = packet; + + while (pktSizeCpy > 0) { + /* don't check packetCpy[0] to include SMB version byte at the beginning */ + if (packetCpy[1] == 'S') { + if (packetCpy[2] == 'M') { + if (packetCpy[3] == 'B') { + break; + } + } + } + packetCpy++, pktSizeCpy--; + } + + if ((int)pktSizeCpy < 64) { + DBGPRINTF("SMB packet too small : %d\n", pktSizeCpy); + RETURN_DATA_AFTER(0) + } + + /* Union to prevent cast from uchar to smb_header_t */ + union { + const uchar *pck; + smb_header_t *hdr; + } smb_header_to_char; + + smb_header_to_char.pck = packetCpy; + smb_header_t *smb_header = smb_header_to_char.hdr; + + char flags[5] = {0}; + uint64_t seqNum, userID; + uint8_t version; + + version = (smb_header->version == 0xFF) ? 1 : 2; + seqNum = smb_header->comSeqNumber[0] | smb_header->comSeqNumber[1] << 16; + userID = smb_header->userID[0] | smb_header->userID[1] << 16; + + uint8_t i, pos = 0; + for (i = 0; i < 4; ++i) { + if (smb_header->flags & (0x01 << i)) + flags[pos++] = flagCodes[i]; + } + + json_object_object_add(jparent, "SMB_version", json_object_new_int(version)); + json_object_object_add(jparent, "SMB_NTstatus", json_object_new_int64(smb_header->ntStatus)); + json_object_object_add(jparent, "SMB_operation", json_object_new_int(smb_header->opCode)); + json_object_object_add(jparent, "SMB_flags", json_object_new_string(flags)); + json_object_object_add(jparent, "SMB_seqNumber", json_object_new_int64(seqNum)); + json_object_object_add(jparent, "SMB_processID", json_object_new_int64(smb_header->processID)); + json_object_object_add(jparent, "SMB_treeID", json_object_new_int64(smb_header->treeID)); + json_object_object_add(jparent, "SMB_userID", json_object_new_int64(userID)); + + RETURN_DATA_AFTER(0) +} |