summaryrefslogtreecommitdiff
path: root/ares_send.3
diff options
context:
space:
mode:
authorDaniel Stenberg <daniel@haxx.se>2003-10-07 21:54:04 +0000
committerDaniel Stenberg <daniel@haxx.se>2003-10-07 21:54:04 +0000
commit5e847a14bd65383ce65f143c578e120899981fd9 (patch)
tree0072e647fe22e05aee94cf4e4bf101209e30626c /ares_send.3
downloadc-ares-5e847a14bd65383ce65f143c578e120899981fd9.tar.gz
c-ares-5e847a14bd65383ce65f143c578e120899981fd9.tar.bz2
c-ares-5e847a14bd65383ce65f143c578e120899981fd9.zip
ares 1.1.1 with collected applied patches
Diffstat (limited to 'ares_send.3')
-rw-r--r--ares_send.3117
1 files changed, 117 insertions, 0 deletions
diff --git a/ares_send.3 b/ares_send.3
new file mode 100644
index 0000000..343aa12
--- /dev/null
+++ b/ares_send.3
@@ -0,0 +1,117 @@
+.\" $Id$
+.\"
+.\" Copyright 1998 by the Massachusetts Institute of Technology.
+.\"
+.\" Permission to use, copy, modify, and distribute this
+.\" software and its documentation for any purpose and without
+.\" fee is hereby granted, provided that the above copyright
+.\" notice appear in all copies and that both that copyright
+.\" notice and this permission notice appear in supporting
+.\" documentation, and that the name of M.I.T. not be used in
+.\" advertising or publicity pertaining to distribution of the
+.\" software without specific, written prior permission.
+.\" M.I.T. makes no representations about the suitability of
+.\" this software for any purpose. It is provided "as is"
+.\" without express or implied warranty.
+.\"
+.TH ARES_SEND 3 "25 July 1998"
+.SH NAME
+ares_send \- Initiate a DNS query
+.SH SYNOPSIS
+.nf
+.B #include <ares.h>
+.PP
+.B typedef void (*ares_callback)(void *\fIarg\fP, int \fIstatus\fP,
+.B unsigned char *\fIabuf\fP, int \fIalen\fP)
+.PP
+.B
+void ares_send(ares_channel \fIchannel\fP, const unsigned char *\fIqbuf\fP,
+.B int \fIqlen\fP, ares_callback \fIcallback\fP, void *\fIarg\fP)
+.fi
+.SH DESCRIPTION
+The
+.B ares_send
+function initiates a DNS query on the name service channel identified
+by
+.IR channel .
+The parameters
+.I qbuf
+and
+.I qlen
+give the DNS query, which should already have been formatted according
+to the DNS protocol. When the query is complete or has failed, the
+ares library will invoke
+.IR callback .
+Completion or failure of the query may happen immediately, or may
+happen during a later call to
+.BR ares_process (3)
+or
+.BR ares_destroy (3).
+.PP
+The callback argument
+.I arg
+is copied from the
+.B ares_send
+argument
+.IR arg .
+The callback argument
+.I status
+indicates whether the query succeeded and, if not, how it failed. It
+may have any of the following values:
+.TP 19
+.B ARES_SUCCESS
+The query completed.
+.TP 19
+.B ARES_EBADQUERY
+The query buffer was poorly formed (was not long enough for a DNS
+header or was too long for TCP transmission).
+.TP 19
+.B ARES_ETIMEOUT
+No name servers responded within the timeout period.
+.TP 19
+.B ARES_ECONNREFUSED
+No name servers could be contacted.
+.TP 19
+.B ARES_ENOMEM
+Memory was exhausted.
+.TP 19
+.B ARES_EDESTRUCTION
+The name service channel
+.I channel
+is being destroyed; the query will not be completed.
+.PP
+If the query completed, the callback argument
+.I abuf
+points to a result buffer of length
+.IR alen .
+If the query did not complete,
+.I abuf
+will be NULL and
+.I alen
+will be 0.
+.PP
+Unless the flag
+.B ARES_FLAG_NOCHECKRESP
+was set at channel initialization time,
+.B ares_send
+will normally ignore responses whose questions do not match the
+questions in
+.IR qbuf ,
+as well as responses with reply codes of
+.BR SERVFAIL ,
+.BR NOTIMP ,
+and
+.BR REFUSED .
+Unlike other query functions in the ares library, however,
+.B ares_send
+does not inspect the header of the reply packet to determine the error
+status, so a callback status of
+.B ARES_SUCCESS
+does not reflect as much about the response as for other query
+functions.
+.SH SEE ALSO
+.BR ares_process (3)
+.SH AUTHOR
+Greg Hudson, MIT Information Systems
+.br
+Copyright 1998 by the Massachusetts Institute of Technology.