This diff adds support for some more ND options to tcpdump: printing
v6 nameserver addresses from RDNSS options, and basic support to print
the option name (rather than just "unknown opt_type=XX") for DNSSL
and RFC4191 route information (no full printer for these yet - for
DNSSL the domain names are sent with DNS-encoding so it could do with
ns_nprint() being exposed).
Any comments/OKs?
sample rtadvd.conf to include some data that will be handled by this:
default:\
:rdnss="2001:4860:4860::8888,2001:4860:4860::8844":\
:dnssl="openbsd.org"
vlan2:tc=default
vlan3:tc=default
Index: print-icmp6.c
===================================================================
RCS file: /cvs/src/usr.sbin/tcpdump/print-icmp6.c,v
retrieving revision 1.15
diff -u -p -r1.15 print-icmp6.c
--- print-icmp6.c 16 Jan 2015 06:40:21 -0000 1.15
+++ print-icmp6.c 2 Nov 2015 16:53:44 -0000
@@ -511,8 +511,9 @@ icmp6_opt_print(register const u_char *b
register const struct nd_opt_prefix_info *opp;
register const struct icmp6_opts_redirect *opr;
register const struct nd_opt_mtu *opm;
+ register const struct nd_opt_rdnss *oprd;
register const u_char *ep;
- int opts_len;
+ int i, opts_len;
#if 0
register const struct ip6_hdr *ip;
register const char *str;
@@ -623,6 +624,34 @@ icmp6_opt_print(register const u_char *b
if (opm->nd_opt_mtu_len != 1)
printf("!");
printf(")");
+ icmp6_opt_print((const u_char *)op + (op->nd_opt_len << 3),
+ resid - (op->nd_opt_len << 3));
+ break;
+ case ND_OPT_ROUTE_INFO:
+ printf("(route-info: opt_len=%d)", op->nd_opt_len);
+ icmp6_opt_print((const u_char *)op + (op->nd_opt_len << 3),
+ resid - (op->nd_opt_len << 3));
+ break;
+ case ND_OPT_RDNSS:
+ oprd = (const struct nd_opt_rdnss *)op;
+ printf("(rdnss: ");
+ TCHECK(oprd->nd_opt_rdnss_lifetime);
+ printf("lifetime=%us",
+ (u_int32_t)ntohl(oprd->nd_opt_rdnss_lifetime));
+ if (oprd->nd_opt_rdnss_len < 3) {
+ printf("!");
+ } else for (i = 0; i < ((oprd->nd_opt_rdnss_len - 1) / 2); i++)
{
+ struct in6_addr *addr = (struct in6_addr *)(oprd + 1) +
i;
+ TCHECK2(*addr, sizeof(struct in6_addr));
+ printf(", addr=%s", ip6addr_string(addr));
+ }
+ printf(")");
+ icmp6_opt_print((const u_char *)op + (op->nd_opt_len << 3),
+ resid - (op->nd_opt_len << 3));
+ break;
+ case ND_OPT_DNSSL:
+ printf("(dnssl: opt_len=%d)", op->nd_opt_len);
+ /* XXX */
icmp6_opt_print((const u_char *)op + (op->nd_opt_len << 3),
resid - (op->nd_opt_len << 3));
break;
