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| author | Jo-Philipp Wich | 2019-06-27 17:27:28 +0200 |
|---|---|---|
| committer | Denys Vlasenko | 2019-10-27 17:02:08 +0100 |
| commit | 8c3b520d4f937b1d1856898dec5f634b12d9cc36 (patch) | |
| tree | 3567d74bdf6f3bacef0468347d932f97babc9349 | |
| parent | caf5ee0dd9250a4ca913691bcdc247f8fe814e22 (diff) | |
| download | busybox-8c3b520d4f937b1d1856898dec5f634b12d9cc36.zip busybox-8c3b520d4f937b1d1856898dec5f634b12d9cc36.tar.gz | |
nslookup: handle replies without RRs
Under some circumstances, a DNS reply might contain no resource records,
e.g. when a valid domain is queried that does not have records of the
requested type.
Example with nslookup from BIND dnsutils:
$ nslookup -q=SRV example.org
Server: 10.11.12.13
Address: 10.11.12.13#53
Non-authoritative answer:
*** Can't find example.org: No answer
Currently the busybox nslookup applet simply prints nothing after the
"Non-authoritative answer:" line in the same situation.
This change modifies nslookup to either print "Parse error" or "No answer"
diagnostics, depending on the parse_reply() return value.
function old new delta
send_queries 1676 1711 +35
Signed-off-by: Jo-Philipp Wich <jo@mein.io>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
| -rw-r--r-- | networking/nslookup.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/networking/nslookup.c b/networking/nslookup.c index 8adde14..a7dd823 100644 --- a/networking/nslookup.c +++ b/networking/nslookup.c @@ -615,9 +615,15 @@ static int send_queries(struct ns *ns) G.query[qn].name, rcodes[rcode]); G.exitcode = EXIT_FAILURE; } else { - if (parse_reply(reply, recvlen) < 0) { + switch (parse_reply(reply, recvlen)) { + case -1: printf("*** Can't find %s: Parse error\n", G.query[qn].name); G.exitcode = EXIT_FAILURE; + break; + + case 0: + printf("*** Can't find %s: No answer\n", G.query[qn].name); + break; } } bb_putchar('\n'); |