#include "interface.h"
#include "extract.h"
+static const char tstr[] = "[|babel]";
+
static void babel_print_v2(const u_char *cp, u_int length);
void
return;
trunc:
- printf(" [|babel]");
+ printf(" %s", tstr);
return;
}
+/* TLVs */
#define MESSAGE_PAD1 0
#define MESSAGE_PADN 1
#define MESSAGE_ACK_REQ 2
#define MESSAGE_TSPC 11
#define MESSAGE_HMAC 12
+/* sub-TLVs */
+#define MESSAGE_SUB_PAD1 0
+#define MESSAGE_SUB_PADN 1
+#define MESSAGE_SUB_DIVERSITY 2
+
+/* Diversity sub-TLV channel codes */
+static const struct tok diversity_str[] = {
+ { 0, "reserved" },
+ { 255, "all" },
+ { 0, NULL }
+};
+
static const char *
format_id(const u_char *id)
{
#endif
}
+static const char *
+format_interval(const u_int16_t i)
+{
+ static char buf[sizeof("0000.0s")];
+
+ if (i == 0)
+ return "0.0s (bogus)";
+ snprintf(buf, sizeof(buf), "%u.%us", i / 10, i % 10);
+ return buf;
+}
+
+static const char *
+format_interval_update(const u_int16_t i)
+{
+ return i == 0xFFFF ? "infinity" : format_interval(i);
+}
+
+/* Return number of octets consumed from the input buffer (not the prefix length
+ * in bytes), or -1 for encoding error. */
static int
network_prefix(int ae, int plen, unsigned int omitted,
const unsigned char *p, const unsigned char *dp,
{
unsigned pb;
unsigned char prefix[16];
+ int consumed = 0;
if(plen >= 0)
pb = (plen + 7) / 8;
if (dp == NULL) return -1;
memcpy(prefix, dp, 12 + omitted);
}
- if(pb > omitted) memcpy(prefix + 12 + omitted, p, pb - omitted);
+ if(pb > omitted) {
+ memcpy(prefix + 12 + omitted, p, pb - omitted);
+ consumed = pb - omitted;
+ }
break;
case 2:
if(omitted > 16 || (pb > omitted && len < pb - omitted))
if (dp == NULL) return -1;
memcpy(prefix, dp, omitted);
}
- if(pb > omitted) memcpy(prefix + omitted, p, pb - omitted);
+ if(pb > omitted) {
+ memcpy(prefix + omitted, p, pb - omitted);
+ consumed = pb - omitted;
+ }
break;
case 3:
if(pb > 8 && len < pb - 8) return -1;
prefix[0] = 0xfe;
prefix[1] = 0x80;
- if(pb > 8) memcpy(prefix + 8, p, pb - 8);
+ if(pb > 8) {
+ memcpy(prefix + 8, p, pb - 8);
+ consumed = pb - 8;
+ }
break;
default:
return -1;
}
memcpy(p_r, prefix, 16);
- return 1;
+ return consumed;
}
static int
return network_prefix(ae, -1, 0, a, NULL, len, a_r);
}
+/*
+ * Sub-TLVs consume the "extra data" of Babel TLVs (see Section 4.3 of RFC6126),
+ * their encoding is similar to the encoding of TLVs, but the type namespace is
+ * different:
+ *
+ * o Type 0 stands for Pad1 sub-TLV with the same encoding as the Pad1 TLV.
+ * o Type 1 stands for PadN sub-TLV with the same encoding as the PadN TLV.
+ * o Type 2 stands for Diversity sub-TLV, which propagates diversity routing
+ * data. Its body is a variable-length sequence of 8-bit unsigned integers,
+ * each representing per-hop number of interferring radio channel for the
+ * prefix. Channel 0 is invalid and must not be used in the sub-TLV, channel
+ * 255 interferes with any other channel.
+ *
+ * Sub-TLV types 0 and 1 are valid for any TLV type, whether sub-TLV type 2 is
+ * only valid for TLV type 8 (Update). Note that within an Update TLV a missing
+ * Diversity sub-TLV is not the same as a Diversity sub-TLV with an empty body.
+ * The former would mean a lack of any claims about the interference, and the
+ * latter would state that interference is definitely absent. */
+static void
+subtlvs_print(const u_char *cp, const u_char *ep, const uint8_t tlv_type) {
+ uint8_t subtype, sublen;
+ const char *sep;
+
+ while (cp < ep) {
+ subtype = *cp++;
+ if(subtype == MESSAGE_SUB_PAD1) {
+ printf(" sub-pad1");
+ continue;
+ }
+ if(cp == ep)
+ goto corrupt;
+ sublen = *cp++;
+ if(cp + sublen > ep)
+ goto corrupt;
+
+ switch(subtype) {
+ case MESSAGE_SUB_PADN:
+ printf(" sub-padn");
+ cp += sublen;
+ break;
+ case MESSAGE_SUB_DIVERSITY:
+ printf(" sub-diversity");
+ if (sublen == 0) {
+ printf(" empty");
+ break;
+ }
+ sep = " ";
+ while(sublen--) {
+ printf("%s%s", sep, tok2str(diversity_str, "%u", *cp++));
+ sep = "-";
+ }
+ if(tlv_type != MESSAGE_UPDATE)
+ printf(" (bogus)");
+ break;
+ default:
+ printf(" sub-unknown-0x%02x", subtype);
+ cp += sublen;
+ } /* switch */
+ } /* while */
+ return;
+
+ corrupt:
+ printf(" (corrupt)");
+}
+
#define ICHECK(i, l) \
if ((i) + (l) > bodylen || (i) + (l) > length) goto corrupt;
u_int type, len;
message = cp + 4 + i;
+
+ TCHECK2(*message, 1);
+ if((type = message[0]) == MESSAGE_PAD1) {
+ printf(vflag ? "\n\tPad 1" : " pad1");
+ i += 1;
+ continue;
+ }
+
TCHECK2(*message, 2);
ICHECK(i, 2);
- type = message[0];
len = message[1];
TCHECK2(*message, 2 + len);
ICHECK(i, 2 + len);
switch(type) {
- case MESSAGE_PAD1: {
- if(!vflag)
- printf(" pad1");
- else
- printf("\n\tPad 1");
- }
- break;
-
case MESSAGE_PADN: {
if(!vflag)
printf(" padN");
if(len < 6) goto corrupt;
nonce = EXTRACT_16BITS(message + 4);
interval = EXTRACT_16BITS(message + 6);
- printf("%04x %d", nonce, interval);
+ printf("%04x %s", nonce, format_interval(interval));
}
}
break;
if(len < 6) goto corrupt;
seqno = EXTRACT_16BITS(message + 4);
interval = EXTRACT_16BITS(message + 6);
- printf("seqno %u interval %u", seqno, interval);
+ printf("seqno %u interval %s", seqno, format_interval(interval));
}
}
break;
txcost = EXTRACT_16BITS(message + 4);
interval = EXTRACT_16BITS(message + 6);
rc = network_address(message[2], message + 8, len - 6, address);
- if(rc < 0) { printf("[|babel]"); break; }
- printf("%s txcost %u interval %d",
- format_address(address), txcost, interval);
+ if(rc < 0) { printf("%s", tstr); break; }
+ printf("%s txcost %u interval %s",
+ format_address(address), txcost, format_interval(interval));
}
}
break;
interval = EXTRACT_16BITS(message + 6);
seqno = EXTRACT_16BITS(message + 8);
metric = EXTRACT_16BITS(message + 10);
- printf("%s%s%s %s metric %u seqno %u interval %u",
+ printf("%s%s%s %s metric %u seqno %u interval %s",
(message[3] & 0x80) ? "/prefix": "",
(message[3] & 0x40) ? "/id" : "",
(message[3] & 0x3f) ? "/unknown" : "",
format_prefix(prefix, plen),
- metric, seqno, interval);
+ metric, seqno, format_interval_update(interval));
if(message[3] & 0x80) {
if(message[2] == 1)
memcpy(v4_prefix, prefix, 16);
else
memcpy(v6_prefix, prefix, 16);
}
+ /* extra data? */
+ if((u_int)rc < len - 10)
+ subtlvs_print(message + 12 + rc, message + 2 + len, type);
}
}
break;
return;
trunc:
- printf(" [|babel]");
+ printf(" %s", tstr);
return;
corrupt:
projects / tcpdump / blobdiff