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author | ume <ume@FreeBSD.org> | 2001-06-10 20:25:24 +0000 |
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committer | ume <ume@FreeBSD.org> | 2001-06-10 20:25:24 +0000 |
commit | 32dc912febbf3960c47a0ebfd387977b2c78656b (patch) | |
tree | 262ae419994b75015819bd1f21a102e4d30832d2 /lib/libc/net/res_mkquery.c | |
parent | 28fc250493cc9938edeed93280f363eeba7bcd2f (diff) | |
download | FreeBSD-src-32dc912febbf3960c47a0ebfd387977b2c78656b.zip FreeBSD-src-32dc912febbf3960c47a0ebfd387977b2c78656b.tar.gz |
Implement EDNS0 support, as EDNS0 support will be made mandatory for
IPv6 transport-ready resolvers/DNS servers. Need careful configuration
when enable it. (default config is not affected).
See manpage for details.
XXX visible symbol __res_opt() is added, however, it is not supposed to be
called from outside, libc minor is not bumped.
Obtained from: KAME/NetBSD
Diffstat (limited to 'lib/libc/net/res_mkquery.c')
-rw-r--r-- | lib/libc/net/res_mkquery.c | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/lib/libc/net/res_mkquery.c b/lib/libc/net/res_mkquery.c index 5ac662b..6cbd373 100644 --- a/lib/libc/net/res_mkquery.c +++ b/lib/libc/net/res_mkquery.c @@ -204,3 +204,40 @@ res_mkquery(op, dname, class, type, data, datalen, newrr_in, buf, buflen) */ #undef res_mkquery __weak_reference(__res_mkquery, res_mkquery); + +/* attach OPT pseudo-RR, as documented in RFC2671 (EDNS0). */ +int +res_opt(n0, buf, buflen, anslen) + int n0; + u_char *buf; /* buffer to put query */ + int buflen; /* size of buffer */ + int anslen; /* answer buffer length */ +{ + register HEADER *hp; + register u_char *cp; + + hp = (HEADER *) buf; + cp = buf + n0; + buflen -= n0; + + if (buflen < 1 + RRFIXEDSZ) + return -1; + + *cp++ = 0; /* "." */ + buflen--; + + __putshort(T_OPT, cp); /* TYPE */ + cp += INT16SZ; + __putshort(anslen & 0xffff, cp); /* CLASS = UDP payload size */ + cp += INT16SZ; + *cp++ = NOERROR; /* extended RCODE */ + *cp++ = 0; /* EDNS version */ + __putshort(0, cp); /* MBZ */ + cp += INT16SZ; + __putshort(0, cp); /* RDLEN */ + cp += INT16SZ; + hp->arcount = htons(ntohs(hp->arcount) + 1); + buflen -= RRFIXEDSZ; + + return cp - buf; +} |