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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 17:39:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 17:39:49 +0000 |
commit | a0aa2307322cd47bbf416810ac0292925e03be87 (patch) | |
tree | 37076262a026c4b48c8a0e84f44ff9187556ca35 /src/decode-geneve.c | |
parent | Initial commit. (diff) | |
download | suricata-a0aa2307322cd47bbf416810ac0292925e03be87.tar.xz suricata-a0aa2307322cd47bbf416810ac0292925e03be87.zip |
Adding upstream version 1:7.0.3.upstream/1%7.0.3
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/decode-geneve.c')
-rw-r--r-- | src/decode-geneve.c | 499 |
1 files changed, 499 insertions, 0 deletions
diff --git a/src/decode-geneve.c b/src/decode-geneve.c new file mode 100644 index 0000000..29038f8 --- /dev/null +++ b/src/decode-geneve.c @@ -0,0 +1,499 @@ +/* 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. + */ + +/** + * \file + * + * \author Ali Jad Khalil <jadkhal@amazon.com> + * + * Geneve tunneling scheme decoder. + * + * This implementation is based on the following specification doc: + * https://tools.ietf.org/html/draft-ietf-nvo3-geneve-16#section-3 + */ + +#include "suricata-common.h" +#include "decode.h" +#include "decode-geneve.h" +#include "decode-events.h" + +#include "detect.h" +#include "detect-engine-port.h" + +#include "flow.h" + +#include "util-validate.h" +#include "util-unittest.h" +#include "util-debug.h" + +#include "pkt-var.h" +#include "util-profiling.h" +#include "host.h" + +#define VALID_GENEVE_VERSIONS \ + { \ + 0 \ + } +#define GENEVE_VERSION(hdr_ptr) (hdr_ptr->ver_plus_len >> 6) +#define GENEVE_RESERVED_FLAGS(hdr_ptr) (hdr_ptr->flags & 0x3F) + +#define GENEVE_MIN_HEADER_LEN sizeof(GeneveHeader) +#define GENEVE_TOTAL_OPT_LEN(hdr_ptr) ((uint8_t)((hdr_ptr->ver_plus_len & 0x3F) << 2)) +#define GENEVE_TOTAL_HEADER_LEN(hdr_ptr) (GENEVE_MIN_HEADER_LEN + GENEVE_TOTAL_OPT_LEN(hdr_ptr)) + +#define GENEVE_MIN_SINGLE_OPT_LEN sizeof(GeneveOption) +#define GENEVE_SINGLE_OPT_LEN(option_ptr) ((uint8_t)((option_ptr->flags_plus_len & 0x1F) << 2)) +#define GENEVE_SINGLE_OPT_TOTAL_LEN(option_ptr) \ + (GENEVE_MIN_SINGLE_OPT_LEN + GENEVE_SINGLE_OPT_LEN(option_ptr)) + +#define GENEVE_MAX_PORTS 4 +#define GENEVE_UNSET_PORT -1 +#define GENEVE_DEFAULT_PORT 6081 +#define GENEVE_DEFAULT_PORT_S "6081" + +static bool g_geneve_enabled = true; +static int g_geneve_ports_idx = 0; +static int g_geneve_ports[GENEVE_MAX_PORTS] = { GENEVE_DEFAULT_PORT, GENEVE_UNSET_PORT, + GENEVE_UNSET_PORT, GENEVE_UNSET_PORT }; + +/* Geneve structs based on diagrams from the following specification doc: + * https://tools.ietf.org/html/draft-ietf-nvo3-geneve-16#section-3 */ +typedef struct GeneveOption_ { + uint16_t option_class; + uint8_t type; + uint8_t flags_plus_len; + uint8_t option_data[0]; +} GeneveOption; + +typedef struct GeneveHeader_ { + uint8_t ver_plus_len; + uint8_t flags; + uint16_t eth_type; + uint8_t vni[3]; + uint8_t res; + GeneveOption options[0]; +} GeneveHeader; + +bool DecodeGeneveEnabledForPort(const uint16_t sp, const uint16_t dp) +{ + SCLogDebug("ports %u->%u ports %d %d %d %d", sp, dp, g_geneve_ports[0], g_geneve_ports[1], + g_geneve_ports[2], g_geneve_ports[3]); + + if (g_geneve_enabled) { + for (int i = 0; i < g_geneve_ports_idx; i++) { + if (g_geneve_ports[i] == GENEVE_UNSET_PORT) + return false; + + const int port = g_geneve_ports[i]; + if (port == (const int)sp || port == (const int)dp) + return true; + } + } + return false; +} + +static void DecodeGeneveConfigPorts(const char *pstr) +{ + SCLogDebug("parsing \'%s\'", pstr); + + DetectPort *head = NULL; + DetectPortParse(NULL, &head, pstr); + + g_geneve_ports_idx = 0; + for (DetectPort *p = head; p != NULL; p = p->next) { + if (g_geneve_ports_idx >= GENEVE_MAX_PORTS) { + SCLogWarning("more than %d Geneve ports defined", GENEVE_MAX_PORTS); + break; + } + g_geneve_ports[g_geneve_ports_idx++] = (int)p->port; + } + + DetectPortCleanupList(NULL, head); +} + +void DecodeGeneveConfig(void) +{ + int enabled = 0; + if (ConfGetBool("decoder.geneve.enabled", &enabled) == 1) { + if (enabled) { + g_geneve_enabled = true; + } else { + g_geneve_enabled = false; + } + } + + if (g_geneve_enabled) { + ConfNode *node = ConfGetNode("decoder.geneve.ports"); + if (node && node->val) { + DecodeGeneveConfigPorts(node->val); + } else { + DecodeGeneveConfigPorts(GENEVE_DEFAULT_PORT_S); + } + } +} + +static inline bool IsValidGeneveVersion(const GeneveHeader *geneve_hdr) +{ + const int valid_versions[] = VALID_GENEVE_VERSIONS; + const int num_versions = sizeof(valid_versions) / sizeof(int); + const uint8_t cur_version = GENEVE_VERSION(geneve_hdr); + + for (int i = 0; i < num_versions; i++) { + if (valid_versions[i] == cur_version) + return true; + } + + return false; +} + +/* Performs a check to ensure that option lens add up to total length specified in the fixed header + */ +static inline bool IsHeaderLengthConsistentWithOptions(const GeneveHeader *geneve_hdr) +{ + uint8_t *geneve_opt_ptr = (uint8_t *)geneve_hdr->options; + int remaining_hdr_len = GENEVE_TOTAL_OPT_LEN(geneve_hdr); + + while (remaining_hdr_len > 0) { + const GeneveOption *cur_opt = (const GeneveOption *)geneve_opt_ptr; + const uint8_t cur_option_len = GENEVE_SINGLE_OPT_TOTAL_LEN(cur_opt); + + geneve_opt_ptr += cur_option_len; + remaining_hdr_len -= + cur_option_len; /* cur_option_len will always be between 4-128, inclusive */ + } + + return (remaining_hdr_len == 0); +} + +/** \param pkt payload data directly above UDP header + * \param len length in bytes of pkt + */ +int DecodeGeneve(ThreadVars *tv, DecodeThreadVars *dtv, Packet *p, const uint8_t *pkt, uint32_t len) +{ + DEBUG_VALIDATE_BUG_ON(pkt == NULL); + + const GeneveHeader *geneve_hdr = (const GeneveHeader *)pkt; + + uint16_t eth_type, geneve_hdr_len; + int decode_tunnel_proto = DECODE_TUNNEL_UNSET; + + /* General Geneve packet validation */ + if (unlikely(!g_geneve_enabled)) + return TM_ECODE_FAILED; + + if (unlikely(len < GENEVE_MIN_HEADER_LEN)) + return TM_ECODE_FAILED; + if (!PacketIncreaseCheckLayers(p)) { + return TM_ECODE_FAILED; + } + + /* Specific Geneve header field validation */ + geneve_hdr_len = GENEVE_TOTAL_HEADER_LEN(geneve_hdr); + if (len < geneve_hdr_len) + return TM_ECODE_FAILED; + + if (!IsValidGeneveVersion(geneve_hdr)) + return TM_ECODE_FAILED; + + if (GENEVE_RESERVED_FLAGS(geneve_hdr) != 0 || geneve_hdr->res != 0) + return TM_ECODE_FAILED; + + if (!IsHeaderLengthConsistentWithOptions(geneve_hdr)) + return TM_ECODE_FAILED; + +#if DEBUG + /* Print the VNI for debugging purposes */ + uint32_t vni = (geneve_hdr->vni[0] << 16) + (geneve_hdr->vni[1] << 8) + (geneve_hdr->vni[2]); + SCLogDebug("Geneve vni %u", vni); +#endif + + /* Increment stats counter for Geneve packets */ + StatsIncr(tv, dtv->counter_geneve); + + /* Determine first protocol encapsulated after Geneve header */ + eth_type = SCNtohs(geneve_hdr->eth_type); + SCLogDebug("Geneve ethertype 0x%04x", eth_type); + + switch (eth_type) { + case ETHERNET_TYPE_IP: + SCLogDebug("Geneve found IPv4"); + decode_tunnel_proto = DECODE_TUNNEL_IPV4; + break; + case ETHERNET_TYPE_IPV6: + SCLogDebug("Geneve found IPv6"); + decode_tunnel_proto = DECODE_TUNNEL_IPV6; + break; + case ETHERNET_TYPE_BRIDGE: + SCLogDebug("Geneve found Ethernet"); + decode_tunnel_proto = DECODE_TUNNEL_ETHERNET; + break; + case ETHERNET_TYPE_ARP: + SCLogDebug("Geneve found ARP"); + break; + default: + SCLogDebug( + "Geneve found unsupported Ethertype - expected IPv4, IPv6, ARP, or Ethernet"); + ENGINE_SET_INVALID_EVENT(p, GENEVE_UNKNOWN_PAYLOAD_TYPE); + } + + /* Set-up and process inner packet if it is a supported ethertype */ + if (decode_tunnel_proto != DECODE_TUNNEL_UNSET) { + Packet *tp = PacketTunnelPktSetup( + tv, dtv, p, pkt + geneve_hdr_len, len - geneve_hdr_len, decode_tunnel_proto); + + if (tp != NULL) { + PKT_SET_SRC(tp, PKT_SRC_DECODER_GENEVE); + PacketEnqueueNoLock(&tv->decode_pq, tp); + } + } + + return TM_ECODE_OK; +} + +#ifdef UNITTESTS + +/** + * \test DecodeGeneveTest01 tests a good Geneve header with 16-bytes of options. + * Contains a Ethernet+IPv6 DHCP request packet. + */ +static int DecodeGeneveTest01(void) +{ + uint8_t raw_geneve[] = { 0x32, 0x10, 0x17, 0xc1, 0x00, 0xc1, 0x87, 0x51, /* UDP header */ + 0x04, 0x00, 0x65, 0x58, 0x00, 0x00, 0x25, 0x00, /* Geneve fixed header */ + 0x01, 0x08, 0x00, 0x01, 0x11, 0x11, 0x11, 0x11, /* Geneve variable options */ + 0x01, 0x08, 0x00, 0x01, 0x11, 0x11, 0x11, 0x11, /* Geneve variable options */ + 0x33, 0x33, 0x00, 0x01, 0x00, 0x02, /* inner destination MAC */ + 0x08, 0x00, 0x27, 0xfe, 0x8f, 0x95, /* inner source MAC */ + 0x86, 0xdd, /* type is IPv6 0x86dd */ + 0x60, 0x00, 0x00, 0x00, 0x00, 0x6b, 0x11, 0x01, /* IPv6 hdr */ + 0xfe, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0a, 0x00, 0x27, 0xff, 0xfe, 0xfe, 0x8f, + 0x95, 0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, + 0x00, 0x02, 0x02, 0x22, 0x02, 0x23, 0x00, 0x6b, 0x9c, 0xfb, /* UDP src port 546 */ + 0x03, 0x49, 0x17, 0x4e, 0x00, 0x01, 0x00, 0x0e, /* DHCP request payload */ + 0x00, 0x01, 0x00, 0x01, 0x1c, 0x39, 0xcf, 0x88, 0x08, 0x00, 0x27, 0xfe, 0x8f, 0x95, 0x00, + 0x02, 0x00, 0x0e, 0x00, 0x01, 0x00, 0x01, 0x1c, 0x38, 0x25, 0xe8, 0x08, 0x00, 0x27, 0xd4, + 0x10, 0xbb, 0x00, 0x06, 0x00, 0x04, 0x00, 0x17, 0x00, 0x18, 0x00, 0x08, 0x00, 0x02, 0x00, + 0x00, 0x00, 0x19, 0x00, 0x29, 0x27, 0xfe, 0x8f, 0x95, 0x00, 0x00, 0x0e, 0x10, 0x00, 0x00, + 0x15, 0x18, 0x00, 0x1a, 0x00, 0x19, 0x00, 0x00, 0x1c, 0x20, 0x00, 0x00, 0x1d, 0x4c, 0x40, + 0x20, 0x01, 0x00, 0x00, 0x00, 0x00, 0xfe, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x00 }; + + Packet *p = PacketGetFromAlloc(); + FAIL_IF_NULL(p); + ThreadVars tv; + DecodeThreadVars dtv; + + DecodeGeneveConfigPorts(GENEVE_DEFAULT_PORT_S); + + memset(&tv, 0, sizeof(ThreadVars)); + memset(&dtv, 0, sizeof(DecodeThreadVars)); + + FlowInitConfig(FLOW_QUIET); + DecodeUDP(&tv, &dtv, p, raw_geneve, sizeof(raw_geneve)); + + FAIL_IF(p->udph == NULL); + FAIL_IF(tv.decode_pq.top == NULL); + + Packet *tp = PacketDequeueNoLock(&tv.decode_pq); + FAIL_IF(tp->udph == NULL); + FAIL_IF_NOT(tp->sp == 546); + + FlowShutdown(); + PacketFree(p); + PacketFree(tp); + PASS; +} + +/** + * \test DecodeGeneveTest02 tests a good Geneve header with 16-bytes of options. + * Contains a IPv4 DNS request packet. + */ +static int DecodeGeneveTest02(void) +{ + uint8_t raw_geneve[] = { + 0x32, 0x10, 0x17, 0xc1, 0x00, 0x3c, 0x87, 0x51, /* UDP header */ + 0x04, 0x00, 0x08, 0x00, 0x00, 0x00, 0x25, 0x00, /* Geneve fixed header */ + 0x01, 0x08, 0x00, 0x01, 0x11, 0x11, 0x11, 0x11, /* Geneve variable options */ + 0x01, 0x08, 0x00, 0x01, 0x11, 0x11, 0x11, 0x11, /* Geneve variable options */ + 0x45, 0x00, 0x00, 0x1c, 0x00, 0x01, 0x00, 0x00, 0x40, 0x11, /* IPv4 hdr */ + 0x44, 0x45, 0x0a, 0x60, 0x00, 0x0a, 0xb9, 0x1b, 0x73, 0x06, 0x00, 0x35, 0x30, 0x39, 0x00, + 0x08, 0x98, 0xe4 /* UDP probe src port 53 */ + }; + + Packet *p = PacketGetFromAlloc(); + FAIL_IF_NULL(p); + ThreadVars tv; + DecodeThreadVars dtv; + + DecodeGeneveConfigPorts(GENEVE_DEFAULT_PORT_S); + + memset(&tv, 0, sizeof(ThreadVars)); + memset(&dtv, 0, sizeof(DecodeThreadVars)); + + FlowInitConfig(FLOW_QUIET); + DecodeUDP(&tv, &dtv, p, raw_geneve, sizeof(raw_geneve)); + + FAIL_IF(p->udph == NULL); + FAIL_IF(tv.decode_pq.top == NULL); + + Packet *tp = PacketDequeueNoLock(&tv.decode_pq); + FAIL_IF(tp->udph == NULL); + FAIL_IF_NOT(tp->sp == 53); + + FlowShutdown(); + PacketFree(p); + PacketFree(tp); + PASS; +} + +/** + * \test DecodeGeneveTest03 tests a good Geneve header with 16-bytes of options. + * Contains a IPv4 DNS request packet with a VLAN tag after the Ethernet frame. + * In practice, this probably won't be used but it should be support either way. + */ +static int DecodeGeneveTest03(void) +{ + uint8_t raw_geneve[] = { + 0x32, 0x10, 0x17, 0xc1, 0x00, 0x4e, 0x87, 0x51, /* UDP header */ + 0x04, 0x00, 0x65, 0x58, 0x00, 0x00, 0x25, 0x00, /* Geneve fixed header */ + 0x01, 0x08, 0x00, 0x01, 0x11, 0x11, 0x11, 0x11, /* Geneve variable options */ + 0x01, 0x08, 0x00, 0x01, 0x11, 0x11, 0x11, 0x11, /* Geneve variable options */ + 0x33, 0x33, 0x00, 0x01, 0x00, 0x02, /* inner destination MAC */ + 0x08, 0x00, 0x27, 0xfe, 0x8f, 0x95, /* inner source MAC */ + 0x81, 0x00, 0x00, 0xad, /* 802.1Q VLAN tag */ + 0x08, 0x00, /* type is IPv4 0x0800 */ + 0x45, 0x00, 0x00, 0x1c, 0x00, 0x01, 0x00, 0x00, 0x40, 0x11, /* IPv4 hdr */ + 0x44, 0x45, 0x0a, 0x60, 0x00, 0x0a, 0xb9, 0x1b, 0x73, 0x06, 0x00, 0x35, 0x30, 0x39, 0x00, + 0x08, 0x98, 0xe4 /* UDP probe src port 53 */ + }; + + Packet *p = PacketGetFromAlloc(); + FAIL_IF_NULL(p); + ThreadVars tv; + DecodeThreadVars dtv; + + DecodeGeneveConfigPorts(GENEVE_DEFAULT_PORT_S); + + memset(&tv, 0, sizeof(ThreadVars)); + memset(&dtv, 0, sizeof(DecodeThreadVars)); + + FlowInitConfig(FLOW_QUIET); + DecodeUDP(&tv, &dtv, p, raw_geneve, sizeof(raw_geneve)); + + FAIL_IF(p->udph == NULL); + FAIL_IF(tv.decode_pq.top == NULL); + + Packet *tp = PacketDequeueNoLock(&tv.decode_pq); + FAIL_IF(tp->udph == NULL); + FAIL_IF_NOT(tp->sp == 53); + + FlowShutdown(); + PacketFree(p); + PacketFree(tp); + PASS; +} + +/** + * \test DecodeGeneveTest04 tests default port disabled by the config. + */ +static int DecodeGeneveTest04(void) +{ + uint8_t raw_geneve[] = { + 0x32, 0x10, 0x17, 0xc1, 0x00, 0x4a, 0x87, 0x51, /* UDP header */ + 0x04, 0x00, 0x65, 0x58, 0x00, 0x00, 0x25, 0x00, /* Geneve fixed header */ + 0x01, 0x08, 0x00, 0x01, 0x11, 0x11, 0x11, 0x11, /* Geneve variable options */ + 0x01, 0x08, 0x00, 0x01, 0x11, 0x11, 0x11, 0x11, /* Geneve variable options */ + 0x10, 0x00, 0x00, 0x0c, 0x01, 0x00, /* inner destination MAC */ + 0x00, 0x51, 0x52, 0xb3, 0x54, 0xe5, /* inner source MAC */ + 0x08, 0x00, /* type is IPv4 0x0800 */ + 0x45, 0x00, 0x00, 0x1c, 0x00, 0x01, 0x00, 0x00, 0x40, 0x11, /* IPv4 hdr */ + 0x44, 0x45, 0x0a, 0x60, 0x00, 0x0a, 0xb9, 0x1b, 0x73, 0x06, 0x00, 0x35, 0x30, 0x39, 0x00, + 0x08, 0x98, 0xe4 /* UDP probe src port 53 */ + }; + + Packet *p = PacketGetFromAlloc(); + FAIL_IF_NULL(p); + ThreadVars tv; + DecodeThreadVars dtv; + + DecodeGeneveConfigPorts("1"); /* Set Suricata to use a non-default port for Geneve*/ + + memset(&tv, 0, sizeof(ThreadVars)); + memset(&dtv, 0, sizeof(DecodeThreadVars)); + + FlowInitConfig(FLOW_QUIET); + DecodeUDP(&tv, &dtv, p, raw_geneve, sizeof(raw_geneve)); + + FAIL_IF(p->udph == NULL); + FAIL_IF(tv.decode_pq.top != NULL); /* Geneve packet should not have been processed */ + + DecodeGeneveConfigPorts(GENEVE_DEFAULT_PORT_S); /* Reset Geneve port list for future calls */ + FlowShutdown(); + PacketFree(p); + PASS; +} + +/** + * \test DecodeGeneveTest05 tests if Geneve header has inconsistent option len values. + */ +static int DecodeGeneveTest05(void) +{ + uint8_t raw_geneve[] = { + 0x32, 0x10, 0x17, 0xc1, 0x00, 0x4a, 0x87, 0x51, /* UDP header */ + 0x04, 0x00, 0x65, 0x58, 0x00, 0x00, 0x25, 0x00, /* Geneve fixed header */ + 0x01, 0x08, 0x00, 0x04, 0x11, 0x11, 0x11, 0x11, /* Geneve variable options */ + 0x01, 0x08, 0x00, 0x01, 0x11, 0x11, 0x11, 0x11, /* Geneve variable options */ + 0x10, 0x00, 0x00, 0x0c, 0x01, 0x00, /* inner destination MAC */ + 0x00, 0x51, 0x52, 0xb3, 0x54, 0xe5, /* inner source MAC */ + 0x08, 0x00, /* type is IPv4 0x0800 */ + 0x45, 0x00, 0x00, 0x1c, 0x00, 0x01, 0x00, 0x00, 0x40, 0x11, /* IPv4 hdr */ + 0x44, 0x45, 0x0a, 0x60, 0x00, 0x0a, 0xb9, 0x1b, 0x73, 0x06, 0x00, 0x35, 0x30, 0x39, 0x00, + 0x08, 0x98, 0xe4 /* UDP probe src port 53 */ + }; + + Packet *p = PacketGetFromAlloc(); + FAIL_IF_NULL(p); + ThreadVars tv; + DecodeThreadVars dtv; + + DecodeGeneveConfigPorts(GENEVE_DEFAULT_PORT_S); + + memset(&tv, 0, sizeof(ThreadVars)); + memset(&dtv, 0, sizeof(DecodeThreadVars)); + + FlowInitConfig(FLOW_QUIET); + DecodeUDP(&tv, &dtv, p, raw_geneve, sizeof(raw_geneve)); + + FAIL_IF(p->udph == NULL); + FAIL_IF(tv.decode_pq.top != NULL); /* Geneve packet should not have been processed */ + + FlowShutdown(); + PacketFree(p); + PASS; +} +#endif /* UNITTESTS */ + +void DecodeGeneveRegisterTests(void) +{ +#ifdef UNITTESTS + UtRegisterTest("DecodeGeneveTest01 -- Ethernet+IPv6 DHCP Request", DecodeGeneveTest01); + UtRegisterTest("DecodeGeneveTest02 -- IPv4 DNS Request", DecodeGeneveTest02); + UtRegisterTest("DecodeGeneveTest03 -- VLAN+IPv4 DNS Request", DecodeGeneveTest03); + UtRegisterTest("DecodeGeneveTest04 -- Non-standard port configuration", DecodeGeneveTest04); + UtRegisterTest("DecodeGeneveTest05 -- Inconsistent Geneve hdr option lens", DecodeGeneveTest05); +#endif /* UNITTESTS */ +} |