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From Sheetal Kshirsagar and Andrew Williams: 

Updating the RPL SRH dissector and implementing RPL Options header dissection.

https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=6986

svn path=/trunk/; revision=42937
This commit is contained in:
Anders Broman 2012-05-31 07:25:11 +00:00
parent fc19f32931
commit 867de6145e
2 changed files with 106 additions and 5 deletions
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8
AUTHORS
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@ -3390,6 +3390,14 @@ Mayuresh Raut <msraut [AT] ncsu.edu> {
LSP ping over MPLS tunnels (RFC 6424)
}
Sheetal Kshirsagar <sdkshirs [AT] ncsu.edu> {
RPL SRH dissector enhancements (RFC 6554)
}
Andrew Williams <anwilli5 [AT] ncsu.edu> {
IPv6 preference for RPL SRH strict compliance to RFC 6554
}
Per Liedberg <per.liedberg [AT] ericsson.com> {
RoHC dissection improvments
}

103
epan/dissectors/packet-ipv6.c
View File

@ -303,6 +303,9 @@ static gboolean ipv6_summary_in_tree = TRUE;
static gboolean ipv6_use_geoip = TRUE;
#endif /* HAVE_GEOIP_V6 */
/* Perform strict RFC adherence checking */
static gboolean g_ipv6_rpl_srh_strict_rfc_checking = FALSE;
#ifndef offsetof
#define offsetof(type, member) ((size_t)(&((type *)0)->member))
#endif
@ -554,7 +557,7 @@ enum {
IPv6_RT_HEADER_SOURCE_ROUTING=0,
IPv6_RT_HEADER_NIMROD,
IPv6_RT_HEADER_MobileIP,
IPv6_RT_HEADER_RPL=4
IPv6_RT_HEADER_RPL
};
/* Routing Header Types */
@ -636,17 +639,25 @@ dissect_routing6(tvbuff_t *tvb, int offset, proto_tree *tree, packet_info *pinfo
guint8 cmprI;
guint8 cmprE;
guint8 pad;
guint32 reserved;
gint segments;
/* IPv6 destination address used for elided bytes */
struct e_in6_addr dstAddr;
/* IPv6 source address used for strict checking */
struct e_in6_addr srcAddr;
offset += 4;
memcpy((guint8 *)&dstAddr, (guint8 *)pinfo->dst.data, pinfo->dst.len);
memcpy((guint8 *)&srcAddr, (guint8 *)pinfo->src.data, pinfo->src.len);
/* from RFC6554: Multicast addresses MUST NOT appear in the IPv6 Destination Address field */
if(g_ipv6_rpl_srh_strict_rfc_checking && E_IN6_IS_ADDR_MULTICAST(&dstAddr)){
expert_add_info_format(pinfo, ti, PI_PROTOCOL, PI_WARN, "Destination address must not be a multicast address ");
}
proto_tree_add_item(rthdr_tree, hf_ipv6_routing_hdr_rpl_cmprI, tvb, offset, 4, ENC_BIG_ENDIAN);
proto_tree_add_item(rthdr_tree, hf_ipv6_routing_hdr_rpl_cmprE, tvb, offset, 4, ENC_BIG_ENDIAN);
proto_tree_add_item(rthdr_tree, hf_ipv6_routing_hdr_rpl_pad, tvb, offset, 4, ENC_BIG_ENDIAN);
proto_tree_add_item(rthdr_tree, hf_ipv6_routing_hdr_rpl_reserved, tvb, offset, 4, ENC_BIG_ENDIAN);
cmprI = tvb_get_guint8(tvb, offset) & 0xF0;
cmprE = tvb_get_guint8(tvb, offset) & 0x0F;
@ -656,14 +667,27 @@ dissect_routing6(tvbuff_t *tvb, int offset, proto_tree *tree, packet_info *pinfo
cmprI >>= 4;
pad >>= 4;
/* from draft-ietf-6man-rpl-routing-header-03:
/* from RFC6554: when CmprI and CmprE are both 0, Pad MUST carry a value of 0 */
if(g_ipv6_rpl_srh_strict_rfc_checking && (cmprI == 0 && cmprE == 0 && pad != 0)){
expert_add_info_format(pinfo, ti, PI_PROTOCOL, PI_WARN, "When cmprI equals 0 and cmprE equals 0, pad MUST equal 0 but instead was %d", pad);
}
proto_tree_add_item(rthdr_tree, hf_ipv6_routing_hdr_rpl_reserved, tvb, offset, 4, ENC_BIG_ENDIAN);
reserved = tvb_get_bits32(tvb, ((offset + 1) * 8) + 4, 20, ENC_BIG_ENDIAN);
if(g_ipv6_rpl_srh_strict_rfc_checking && reserved != 0){
expert_add_info_format(pinfo, ti, PI_PROTOCOL, PI_WARN, "Reserved field must equal 0 but instead was %d", reserved);
}
/* from RFC6554:
n = (((Hdr Ext Len * 8) - Pad - (16 - CmprE)) / (16 - CmprI)) + 1 */
segments = (((rt.ip6r_len * 8) - pad - (16 - cmprE)) / (16 - cmprI)) + 1;
ti = proto_tree_add_int(rthdr_tree, hf_ipv6_routing_hdr_rpl_segments, tvb, offset, 2, segments);
PROTO_ITEM_SET_GENERATED(ti);
if ((segments < 0) || (segments > 136)) {
expert_add_info_format(pinfo, ti, PI_MALFORMED, PI_ERROR, "Calculated total segments is invalid, 0 < %d < 136 fails", segments);
if (segments < 0) {
/* This error should always be reported */
expert_add_info_format(pinfo, ti, PI_MALFORMED, PI_ERROR, "Calculated total segments must be greater than or equal to 0, instead was %d", segments);
} else {
offset += 4;
@ -680,6 +704,53 @@ dissect_routing6(tvbuff_t *tvb, int offset, proto_tree *tree, packet_info *pinfo
PROTO_ITEM_SET_GENERATED(ti);
offset += (16-cmprI);
segments--;
if(g_ipv6_rpl_srh_strict_rfc_checking){
/* from RFC6554: */
/* The SRH MUST NOT specify a path that visits a node more than once. */
/* To do this, we will just check the current 'addr' against the next addresses */
gint tempSegments;
gint tempOffset;
tempSegments = segments; /* Has already been decremented above */
tempOffset = offset; /* Has already been moved */
while(tempSegments > 1) {
struct e_in6_addr tempAddr;
memcpy((guint8 *)&tempAddr, (guint8 *)&dstAddr, sizeof(dstAddr));
tvb_memcpy(tvb, (guint8 *)&tempAddr + cmprI, tempOffset, (16-cmprI));
/* Compare the addresses */
if (memcmp(addr.bytes, tempAddr.bytes, 16) == 0) {
/* Found a later address that is the same */
expert_add_info_format(pinfo, ti, PI_PROTOCOL, PI_ERROR, "Multiple instances of the same address must not appear in the source route list");
break;
}
tempOffset += (16-cmprI);
tempSegments--;
}
if (tempSegments == 1) {
struct e_in6_addr tempAddr;
memcpy((guint8 *)&tempAddr, (guint8 *)&dstAddr, sizeof(dstAddr));
tvb_memcpy(tvb, (guint8 *)&tempAddr + cmprE, tempOffset, (16-cmprE));
/* Compare the addresses */
if (memcmp(addr.bytes, tempAddr.bytes, 16) == 0) {
/* Found a later address that is the same */
expert_add_info_format(pinfo, ti, PI_PROTOCOL, PI_ERROR, "Multiple instances of the same address must not appear in the source route list");
}
}
/* IPv6 Source and Destination addresses of the encapsulating datagram (MUST) not appear in the SRH*/
if (memcmp(addr.bytes, srcAddr.bytes, 16) == 0) {
expert_add_info_format(pinfo, ti, PI_PROTOCOL, PI_ERROR, "Source address must not appear in the source route list");
}
if (memcmp(addr.bytes, dstAddr.bytes, 16) == 0) {
expert_add_info_format(pinfo, ti, PI_PROTOCOL, PI_ERROR, "Destination address must not appear in the source route list");
}
/* Multicast addresses MUST NOT appear in the in SRH */
if(E_IN6_IS_ADDR_MULTICAST(&addr)){
expert_add_info_format(pinfo, ti, PI_PROTOCOL, PI_ERROR, "Multicast addresses must not appear in the source route list");
}
}
}
/* We use cmprE for last address for how many bytes to elide, so actual bytes present = 16-CmprE */
@ -693,6 +764,22 @@ dissect_routing6(tvbuff_t *tvb, int offset, proto_tree *tree, packet_info *pinfo
ti = proto_tree_add_ipv6(rthdr_tree, hf_ipv6_routing_hdr_rpl_fulladdr, tvb, offset, (16-cmprE), (guint8 *)&addr);
PROTO_ITEM_SET_GENERATED(ti);
/* offset += (16-cmprE); */
if(g_ipv6_rpl_srh_strict_rfc_checking){
/* IPv6 Source and Destination addresses of the encapsulating datagram (MUST) not appear in the SRH*/
if (memcmp(addr.bytes, srcAddr.bytes, 16) == 0) {
expert_add_info_format(pinfo, ti, PI_PROTOCOL, PI_ERROR, "Source address must not appear in the source route list");
}
if (memcmp(addr.bytes, dstAddr.bytes, 16) == 0) {
expert_add_info_format(pinfo, ti, PI_PROTOCOL, PI_ERROR, "Destination address must not appear in the source route list");
}
/* Multicast addresses MUST NOT appear in the in SRH */
if(E_IN6_IS_ADDR_MULTICAST(&addr)){
expert_add_info_format(pinfo, ti, PI_PROTOCOL, PI_ERROR, "Multicast addresses must not appear in the source route list");
}
}
}
}
}
@ -2702,6 +2789,12 @@ proto_register_ipv6(void)
&ipv6_use_geoip);
#endif /* HAVE_GEOIP_V6 */
/* RPL Strict Header Checking */
prefs_register_bool_preference(ipv6_module, "perform_strict_rpl_srh_rfc_checking",
"Perform strict checking for adherence to the RFC for RPL Source Routing Headers (RFC 6554)",
"Whether to check that all RPL Source Routing Headers adhere to RFC 6554",
&g_ipv6_rpl_srh_strict_rfc_checking);
register_dissector("ipv6", dissect_ipv6, proto_ipv6);
register_init_routine(ipv6_reassemble_init);
ipv6_tap = register_tap("ipv6");