Adding upstream version 1:7.0.3.upstream/1%7.0.3

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 294 insertions, 0 deletions

diff --git a/src/decode-nsh.c b/src/decode-nsh.c
new file mode 100644
index 0000000..64a99ca
--- /dev/null
+++ b/src/decode-nsh.c
@@ -0,0 +1,294 @@
+/* Copyright (C) 2020-2021 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 decode
+ *
+ * @{
+ */
+
+/**
+ * \file
+ *
+ * \author Carl Smith <carl.smith@alliedtelesis.co.nz>
+ *
+ * Decodes Network Service Header (NSH)
+ */
+
+#include "suricata-common.h"
+#include "suricata.h"
+#include "decode.h"
+#include "decode-events.h"
+#include "decode-nsh.h"
+
+#include "util-validate.h"
+#include "util-unittest.h"
+#include "util-debug.h"
+
+/**
+ * \brief Function to decode NSH packets
+ */
+
+int DecodeNSH(ThreadVars *tv, DecodeThreadVars *dtv, Packet *p, const uint8_t *pkt, uint32_t len)
+{
+    DEBUG_VALIDATE_BUG_ON(pkt == NULL);
+
+    StatsIncr(tv, dtv->counter_nsh);
+
+    /* Check minimum header size */
+    if (len < sizeof(NshHdr)) {
+        ENGINE_SET_INVALID_EVENT(p, NSH_HEADER_TOO_SMALL);
+        return TM_ECODE_FAILED;
+    }
+    if (!PacketIncreaseCheckLayers(p)) {
+        return TM_ECODE_FAILED;
+    }
+
+    /* Sanity check the header version */
+    const NshHdr *hdr = (const NshHdr *)pkt;
+    uint16_t version = SCNtohs(hdr->ver_flags_len) >> 14;
+    if (version != 0) {
+        ENGINE_SET_EVENT(p, NSH_UNSUPPORTED_VERSION);
+        return TM_ECODE_OK;
+    }
+
+    /* Should always be some data after the header */
+    uint16_t length = (SCNtohs(hdr->ver_flags_len) & 0x003f) * 4;
+    if (length >= len) {
+        ENGINE_SET_INVALID_EVENT(p, NSH_BAD_HEADER_LENGTH);
+        return TM_ECODE_FAILED;
+    }
+
+    /* Check for valid MD types */
+    uint8_t md_type = hdr->md_type;
+    if (md_type == 0 || md_type == 0xF) {
+        /* We should silently ignore these packets */
+        ENGINE_SET_EVENT(p, NSH_RESERVED_TYPE);
+        return TM_ECODE_OK;
+    } else if (md_type == 1) {
+        /* Fixed header length format */
+        if (length != 24) {
+            ENGINE_SET_INVALID_EVENT(p, NSH_BAD_HEADER_LENGTH);
+            return TM_ECODE_FAILED;
+        }
+    } else if (md_type != 2) {
+        /* Not variable header length either */
+        ENGINE_SET_EVENT(p, NSH_UNSUPPORTED_TYPE);
+        return TM_ECODE_OK;
+    }
+
+    /* Now we can safely read the rest of the header */
+    uint8_t next_protocol = hdr->next_protocol;
+#ifdef DEBUG
+    if (SCLogDebugEnabled()) {
+        uint32_t spi_si = SCNtohl(hdr->spi_si);
+        uint32_t spi = ((spi_si & 0xFFFFFF00) >> 8);
+        uint8_t si = (uint8_t)(spi_si & 0xFF);
+        SCLogDebug("NSH: version %u length %u spi %u si %u next_protocol %u", version, length, spi,
+                si, next_protocol);
+    }
+#endif /* DEBUG */
+
+    /* Try to decode the payload */
+    switch (next_protocol) {
+        case NSH_NEXT_PROTO_IPV4:
+            if (len - length > USHRT_MAX) {
+                return TM_ECODE_FAILED;
+            }
+            return DecodeIPV4(tv, dtv, p, pkt + length, (uint16_t)(len - length));
+        case NSH_NEXT_PROTO_IPV6:
+            if (len - length > USHRT_MAX) {
+                return TM_ECODE_FAILED;
+            }
+            return DecodeIPV6(tv, dtv, p, pkt + length, (uint16_t)(len - length));
+        case NSH_NEXT_PROTO_ETHERNET:
+            return DecodeEthernet(tv, dtv, p, pkt + length, len - length);
+        case NSH_NEXT_PROTO_MPLS:
+            return DecodeMPLS(tv, dtv, p, pkt + length, len - length);
+        case NSH_NEXT_PROTO_NSH:
+        default:
+            SCLogDebug("NSH next protocol %u not supported", next_protocol);
+            ENGINE_SET_EVENT(p, NSH_UNKNOWN_PAYLOAD);
+            break;
+    }
+    return TM_ECODE_OK;
+}
+
+#ifdef UNITTESTS
+
+static uint8_t valid_nsh_packet[] = { 0x00, 0x04, 0x02, 0x01, 0x00, 0x00, 0x02, 0x02, 0x45, 0x10,
+    0x00, 0x3c, 0x78, 0x8f, 0x40, 0x00, 0x3f, 0x06, 0x79, 0x05, 0x0b, 0x06, 0x06, 0x06, 0x33, 0x06,
+    0x06, 0x06, 0xbd, 0x2e, 0x00, 0x16, 0xc9, 0xee, 0x07, 0x62, 0x00, 0x00, 0x00, 0x00, 0xa0, 0x02,
+    0x16, 0xd0, 0x2f, 0x36, 0x00, 0x00, 0x02, 0x04, 0x05, 0xb4, 0x04, 0x02, 0x08, 0x0a, 0xa9, 0x5f,
+    0x7f, 0xed, 0x00, 0x00, 0x00, 0x00, 0x01, 0x03, 0x03, 0x07 };
+
+static int DecodeNSHTestHeaderTooSmall(void)
+{
+    ThreadVars tv;
+    DecodeThreadVars dtv;
+    Packet *p;
+
+    p = PacketGetFromAlloc();
+    FAIL_IF_NULL(p);
+    memset(&dtv, 0, sizeof(DecodeThreadVars));
+    memset(&tv, 0, sizeof(ThreadVars));
+
+    /* A packet that is too small to have a complete NSH header */
+    DecodeNSH(&tv, &dtv, p, valid_nsh_packet, 7);
+    FAIL_IF_NOT(ENGINE_ISSET_EVENT(p, NSH_HEADER_TOO_SMALL));
+
+    SCFree(p);
+    PASS;
+}
+
+static int DecodeNSHTestUnsupportedVersion(void)
+{
+    ThreadVars tv;
+    DecodeThreadVars dtv;
+    Packet *p;
+
+    p = PacketGetFromAlloc();
+    FAIL_IF_NULL(p);
+    memset(&dtv, 0, sizeof(DecodeThreadVars));
+    memset(&tv, 0, sizeof(ThreadVars));
+
+    /* Non-zero version field */
+    valid_nsh_packet[0] = 0xFF;
+    DecodeNSH(&tv, &dtv, p, valid_nsh_packet, sizeof(valid_nsh_packet));
+    valid_nsh_packet[0] = 0x00;
+    FAIL_IF_NOT(ENGINE_ISSET_EVENT(p, NSH_UNSUPPORTED_VERSION));
+
+    SCFree(p);
+    PASS;
+}
+
+static int DecodeNSHTestPacketTooSmall(void)
+{
+    ThreadVars tv;
+    DecodeThreadVars dtv;
+    Packet *p;
+
+    p = PacketGetFromAlloc();
+    FAIL_IF_NULL(p);
+    memset(&dtv, 0, sizeof(DecodeThreadVars));
+    memset(&tv, 0, sizeof(ThreadVars));
+
+    /* A packet that has no payload */
+    DecodeNSH(&tv, &dtv, p, valid_nsh_packet, 8);
+    FAIL_IF_NOT(ENGINE_ISSET_EVENT(p, NSH_BAD_HEADER_LENGTH));
+
+    SCFree(p);
+    PASS;
+}
+
+static int DecodeNSHTestReservedType(void)
+{
+    ThreadVars tv;
+    DecodeThreadVars dtv;
+    Packet *p;
+
+    p = PacketGetFromAlloc();
+    FAIL_IF_NULL(p);
+    memset(&dtv, 0, sizeof(DecodeThreadVars));
+    memset(&tv, 0, sizeof(ThreadVars));
+
+    /* Reserved type */
+    valid_nsh_packet[2] = 0x00;
+    DecodeNSH(&tv, &dtv, p, valid_nsh_packet, sizeof(valid_nsh_packet));
+    valid_nsh_packet[2] = 0x02;
+    FAIL_IF_NOT(ENGINE_ISSET_EVENT(p, NSH_RESERVED_TYPE));
+
+    SCFree(p);
+    PASS;
+}
+
+static int DecodeNSHTestInvalidType(void)
+{
+    ThreadVars tv;
+    DecodeThreadVars dtv;
+    Packet *p;
+
+    p = PacketGetFromAlloc();
+    FAIL_IF_NULL(p);
+    memset(&dtv, 0, sizeof(DecodeThreadVars));
+    memset(&tv, 0, sizeof(ThreadVars));
+
+    /* Type length mismatch */
+    valid_nsh_packet[2] = 0x01;
+    DecodeNSH(&tv, &dtv, p, valid_nsh_packet, sizeof(valid_nsh_packet));
+    valid_nsh_packet[2] = 0x02;
+    FAIL_IF_NOT(ENGINE_ISSET_EVENT(p, NSH_BAD_HEADER_LENGTH));
+    SCFree(p);
+    PASS;
+}
+
+static int DecodeNSHTestUnsupportedType(void)
+{
+    ThreadVars tv;
+    DecodeThreadVars dtv;
+    Packet *p;
+
+    p = PacketGetFromAlloc();
+    FAIL_IF_NULL(p);
+    memset(&dtv, 0, sizeof(DecodeThreadVars));
+    memset(&tv, 0, sizeof(ThreadVars));
+
+    /* Unsupported type */
+    valid_nsh_packet[2] = 0x03;
+    DecodeNSH(&tv, &dtv, p, valid_nsh_packet, sizeof(valid_nsh_packet));
+    valid_nsh_packet[2] = 0x02;
+    FAIL_IF_NOT(ENGINE_ISSET_EVENT(p, NSH_UNSUPPORTED_TYPE));
+
+    SCFree(p);
+    PASS;
+}
+
+static int DecodeNSHTestUnknownPayload(void)
+{
+    ThreadVars tv;
+    DecodeThreadVars dtv;
+    Packet *p;
+
+    p = PacketGetFromAlloc();
+    FAIL_IF_NULL(p);
+    memset(&dtv, 0, sizeof(DecodeThreadVars));
+    memset(&tv, 0, sizeof(ThreadVars));
+
+    /* Unknown type */
+    valid_nsh_packet[3] = 0x99;
+    DecodeNSH(&tv, &dtv, p, valid_nsh_packet, sizeof(valid_nsh_packet));
+    valid_nsh_packet[3] = 0x01;
+    FAIL_IF_NOT(ENGINE_ISSET_EVENT(p, NSH_UNKNOWN_PAYLOAD));
+
+    SCFree(p);
+    PASS;
+}
+
+#endif /* UNITTESTS */
+
+void DecodeNSHRegisterTests(void)
+{
+#ifdef UNITTESTS
+    UtRegisterTest("DecodeNSHTestHeaderTooSmall", DecodeNSHTestHeaderTooSmall);
+    UtRegisterTest("DecodeNSHTestUnsupportedVersion", DecodeNSHTestUnsupportedVersion);
+    UtRegisterTest("DecodeNSHTestPacketTooSmall", DecodeNSHTestPacketTooSmall);
+    UtRegisterTest("DecodeNSHTestReservedType", DecodeNSHTestReservedType);
+    UtRegisterTest("DecodeNSHTestInvalidType", DecodeNSHTestInvalidType);
+    UtRegisterTest("DecodeNSHTestUnsupportedType", DecodeNSHTestUnsupportedType);
+    UtRegisterTest("DecodeNSHTestUnknownPayload", DecodeNSHTestUnknownPayload);
+#endif /* UNITTESTS */
+}