diff options
Diffstat (limited to 'lib/lwres/man/lwres_context.3')
| -rw-r--r-- | lib/lwres/man/lwres_context.3 | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/lib/lwres/man/lwres_context.3 b/lib/lwres/man/lwres_context.3 new file mode 100644 index 0000000..b1022d8 --- /dev/null +++ b/lib/lwres/man/lwres_context.3 @@ -0,0 +1,170 @@ +.\" Copyright (C) 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC") +.\" Copyright (C) 2000, 2001, 2003 Internet Software Consortium. +.\" +.\" Permission to use, copy, modify, and distribute this software for any +.\" purpose with or without fee is hereby granted, provided that the above +.\" copyright notice and this permission notice appear in all copies. +.\" +.\" THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH +.\" REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY +.\" AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, +.\" INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM +.\" LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE +.\" OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR +.\" PERFORMANCE OF THIS SOFTWARE. +.\" +.\" $Id: lwres_context.3,v 1.28 2007/01/30 00:24:59 marka Exp $ +.\" +.hy 0 +.ad l +.\" Title: lwres_context +.\" Author: +.\" Generator: DocBook XSL Stylesheets v1.71.1 <http://docbook.sf.net/> +.\" Date: Jun 30, 2000 +.\" Manual: BIND9 +.\" Source: BIND9 +.\" +.TH "LWRES_CONTEXT" "3" "Jun 30, 2000" "BIND9" "BIND9" +.\" disable hyphenation +.nh +.\" disable justification (adjust text to left margin only) +.ad l +.SH "NAME" +lwres_context_create, lwres_context_destroy, lwres_context_nextserial, lwres_context_initserial, lwres_context_freemem, lwres_context_allocmem, lwres_context_sendrecv \- lightweight resolver context management +.SH "SYNOPSIS" +.nf +#include <lwres/lwres.h> +.fi +.HP 36 +.BI "lwres_result_t lwres_context_create(lwres_context_t\ **" "contextp" ", void\ *" "arg" ", lwres_malloc_t\ " "malloc_function" ", lwres_free_t\ " "free_function" ");" +.HP 37 +.BI "lwres_result_t lwres_context_destroy(lwres_context_t\ **" "contextp" ");" +.HP 30 +.BI "void lwres_context_initserial(lwres_context_t\ *" "ctx" ", lwres_uint32_t\ " "serial" ");" +.HP 40 +.BI "lwres_uint32_t lwres_context_nextserial(lwres_context_t\ *" "ctx" ");" +.HP 27 +.BI "void lwres_context_freemem(lwres_context_t\ *" "ctx" ", void\ *" "mem" ", size_t\ " "len" ");" +.HP 28 +.BI "void lwres_context_allocmem(lwres_context_t\ *" "ctx" ", size_t\ " "len" ");" +.HP 30 +.BI "void * lwres_context_sendrecv(lwres_context_t\ *" "ctx" ", void\ *" "sendbase" ", int\ " "sendlen" ", void\ *" "recvbase" ", int\ " "recvlen" ", int\ *" "recvd_len" ");" +.SH "DESCRIPTION" +.PP +\fBlwres_context_create()\fR +creates a +\fBlwres_context_t\fR +structure for use in lightweight resolver operations. It holds a socket and other data needed for communicating with a resolver daemon. The new +\fBlwres_context_t\fR +is returned through +\fIcontextp\fR, a pointer to a +\fBlwres_context_t\fR +pointer. This +\fBlwres_context_t\fR +pointer must initially be NULL, and is modified to point to the newly created +\fBlwres_context_t\fR. +.PP +When the lightweight resolver needs to perform dynamic memory allocation, it will call +\fImalloc_function\fR +to allocate memory and +\fIfree_function\fR +to free it. If +\fImalloc_function\fR +and +\fIfree_function\fR +are NULL, memory is allocated using +\fBmalloc\fR(3). and +\fBfree\fR(3). It is not permitted to have a NULL +\fImalloc_function\fR +and a non\-NULL +\fIfree_function\fR +or vice versa. +\fIarg\fR +is passed as the first parameter to the memory allocation functions. If +\fImalloc_function\fR +and +\fIfree_function\fR +are NULL, +\fIarg\fR +is unused and should be passed as NULL. +.PP +Once memory for the structure has been allocated, it is initialized using +\fBlwres_conf_init\fR(3) +and returned via +\fI*contextp\fR. +.PP +\fBlwres_context_destroy()\fR +destroys a +\fBlwres_context_t\fR, closing its socket. +\fIcontextp\fR +is a pointer to a pointer to the context that is to be destroyed. The pointer will be set to NULL when the context has been destroyed. +.PP +The context holds a serial number that is used to identify resolver request packets and associate responses with the corresponding requests. This serial number is controlled using +\fBlwres_context_initserial()\fR +and +\fBlwres_context_nextserial()\fR. +\fBlwres_context_initserial()\fR +sets the serial number for context +\fI*ctx\fR +to +\fIserial\fR. +\fBlwres_context_nextserial()\fR +increments the serial number and returns the previous value. +.PP +Memory for a lightweight resolver context is allocated and freed using +\fBlwres_context_allocmem()\fR +and +\fBlwres_context_freemem()\fR. These use whatever allocations were defined when the context was created with +\fBlwres_context_create()\fR. +\fBlwres_context_allocmem()\fR +allocates +\fIlen\fR +bytes of memory and if successful returns a pointer to the allocated storage. +\fBlwres_context_freemem()\fR +frees +\fIlen\fR +bytes of space starting at location +\fImem\fR. +.PP +\fBlwres_context_sendrecv()\fR +performs I/O for the context +\fIctx\fR. Data are read and written from the context's socket. It writes data from +\fIsendbase\fR +\(em typically a lightweight resolver query packet \(em and waits for a reply which is copied to the receive buffer at +\fIrecvbase\fR. The number of bytes that were written to this receive buffer is returned in +\fI*recvd_len\fR. +.SH "RETURN VALUES" +.PP +\fBlwres_context_create()\fR +returns +\fBLWRES_R_NOMEMORY\fR +if memory for the +\fBstruct lwres_context\fR +could not be allocated, +\fBLWRES_R_SUCCESS\fR +otherwise. +.PP +Successful calls to the memory allocator +\fBlwres_context_allocmem()\fR +return a pointer to the start of the allocated space. It returns NULL if memory could not be allocated. +.PP +\fBLWRES_R_SUCCESS\fR +is returned when +\fBlwres_context_sendrecv()\fR +completes successfully. +\fBLWRES_R_IOERROR\fR +is returned if an I/O error occurs and +\fBLWRES_R_TIMEOUT\fR +is returned if +\fBlwres_context_sendrecv()\fR +times out waiting for a response. +.SH "SEE ALSO" +.PP +\fBlwres_conf_init\fR(3), +\fBmalloc\fR(3), +\fBfree\fR(3). +.SH "COPYRIGHT" +Copyright \(co 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC") +.br +Copyright \(co 2000, 2001, 2003 Internet Software Consortium. +.br |