nslookup: implement support for SRV records

Add support for querying and parsing SRV DNS records.

function                                             old     new   delta
send_queries                                        1711    1865    +154
qtypes                                                72      80      +8

Signed-off-by: Jo-Philipp Wich <jo@mein.io>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/networking/nslookup.c b/networking/nslookup.c
index a7dd823f076b85f8a1d752d27610ce20de70ac99..c43e60558b5e2711da6f076fdd87837b5bee7ade 100644 (file)
--- a/networking/nslookup.c
+++ b/networking/nslookup.c
@@ -283,6 +283,7 @@ static const struct {
        { ns_t_cname, "CNAME" },
        { ns_t_mx,    "MX"    },
        { ns_t_txt,   "TXT"   },
+       { ns_t_srv,   "SRV"   },
        { ns_t_ptr,   "PTR"   },
        { ns_t_any,   "ANY"   },
 };
@@ -435,6 +436,25 @@ static int parse_reply(const unsigned char *msg, size_t len)
                        }
                        break;
 
+               case ns_t_srv:
+                       if (rdlen < 6) {
+                               //printf("SRV record too short\n");
+                               return -1;
+                       }
+
+                       cp = ns_rr_rdata(rr);
+                       n = ns_name_uncompress(ns_msg_base(handle), ns_msg_end(handle),
+                                              cp + 6, dname, sizeof(dname));
+
+                       if (n < 0) {
+                               //printf("Unable to uncompress domain: %s\n", strerror(errno));
+                               return -1;
+                       }
+
+                       printf("%s\tservice = %u %u %u %s\n", ns_rr_name(rr),
+                               ns_get16(cp), ns_get16(cp + 2), ns_get16(cp + 4), dname);
+                       break;
+
                case ns_t_soa:
                        if (rdlen < 20) {
                                dbg("SOA record too short:%d\n", rdlen);