1 files changed, 141 insertions, 98 deletions

diff --git a/src/lib/libc/net/gethostbyname.3 b/src/lib/libc/net/gethostbyname.3
index bac0368296..1a05460da4 100644
--- a/src/lib/libc/net/gethostbyname.3
+++ b/src/lib/libc/net/gethostbyname.3
@@ -1,4 +1,4 @@
-.\"     $NetBSD: gethostbyname.3,v 1.6 1995/02/25 06:20:28 cgd Exp $
+.\"     $OpenBSD: gethostbyname.3,v 1.25 2007/05/31 19:19:30 jmc Exp $
 .\"
 .\" Copyright (c) 1983, 1987, 1991, 1993
 .\"     The Regents of the University of California.  All rights reserved.
@@ -11,11 +11,7 @@
 .\" 2. Redistributions in binary form must reproduce the above copyright
 .\"    notice, this list of conditions and the following disclaimer in the
 .\"    documentation and/or other materials provided with the distribution.
-.\" 3. All advertising materials mentioning features or use of this software
-.\"    must display the following acknowledgement:
-.\"     This product includes software developed by the University of
-.\"     California, Berkeley and its contributors.
-.\" 4. Neither the name of the University nor the names of its contributors
+.\" 3. Neither the name of the University nor the names of its contributors
 .\"    may be used to endorse or promote products derived from this software
 .\"    without specific prior written permission.
 .\"
@@ -31,58 +27,66 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.\"     @(#)gethostbyname.3     8.2 (Berkeley) 4/19/94
-.\"
-.Dd April 19, 1994
+.Dd $Mdocdate: May 31 2007 $
 .Dt GETHOSTBYNAME 3
-.Os BSD 4.2
+.Os
 .Sh NAME
 .Nm gethostbyname ,
+.Nm gethostbyname2 ,
 .Nm gethostbyaddr ,
 .Nm gethostent ,
 .Nm sethostent ,
 .Nm endhostent ,
+.Nm hstrerror ,
 .Nm herror
 .Nd get network host entry
 .Sh SYNOPSIS
 .Fd #include <netdb.h>
-.Fd extern int h_errno;
+.Vt extern int h_errno ;
 .Ft struct hostent *
 .Fn gethostbyname "const char *name"
 .Ft struct hostent *
-.Fn gethostbyaddr "const char *addr" "int len" "int type"
+.Fn gethostbyname2 "const char *name" "int af"
+.Ft struct hostent *
+.Fn gethostbyaddr "const void *addr" "socklen_t len" "int af"
 .Ft struct hostent *
 .Fn gethostent void
+.Ft void
 .Fn sethostent "int stayopen"
+.Ft void
 .Fn endhostent void
-.Fn herror "char *string"
+.Ft void
+.Fn herror "const char *string"
+.Ft const char *
+.Fn hstrerror "int err"
 .Sh DESCRIPTION
 The
-.Fn gethostbyname
+.Fn gethostbyname ,
+.Fn gethostbyname2 ,
 and
 .Fn gethostbyaddr
-functions
-each return a pointer to an object with the
-following structure describing an internet host
-referenced by name or by address, respectively.
-This structure contains either the information obtained from the name server,
-.Xr named 8 ,
-broken-out fields from a line in 
+functions each return a pointer to an object with the following structure
+describing an Internet host referenced by name or by address, respectively.
+This structure contains either information obtained from the name server (i.e.,
+.Xr resolver 3
+and
+.Xr named 8 ) ,
+broken-out fields from a line in
 .Pa /etc/hosts ,
 or database entries supplied by the
 .Xr yp 8
-system .
-If the local name server is not running these routines do a lookup in
-.Pa /etc/hosts .
-.Bd -literal
+system.
+.Xr resolv.conf 5
+describes how the particular database is chosen.
+.Bd -literal -offset indent
 struct  hostent {
         char    *h_name;        /* official name of host */
         char    **h_aliases;    /* alias list */
         int     h_addrtype;     /* host address type */
         int     h_length;       /* length of address */
-        char    **h_addr_list;  /* list of addresses from name server */
+        char    **h_addr_list;  /* list of returned addresses */
 };
-#define h_addr  h_addr_list[0]  /* address, for backward compatibility */
+#define h_addr  h_addr_list[0]  /* address, for backward compat */
 .Ed
 .Pp
 The members of this structure are:
@@ -90,36 +94,50 @@ The members of this structure are:
 .It Fa h_name
 Official name of the host.
 .It Fa h_aliases
-A zero terminated array of alternate names for the host.
+A null-terminated array of alternate names for the host.
 .It Fa h_addrtype
-The type of address being returned; currently always
-.Dv AF_INET .
+The type of address being returned.
 .It Fa h_length
 The length, in bytes, of the address.
 .It Fa h_addr_list
-A zero terminated array of network addresses for the host.
+A null-terminated array of network addresses for the host.
 Host addresses are returned in network byte order.
 .It Fa h_addr
 The first address in
 .Fa h_addr_list ;
 this is for backward compatibility.
+.El
 .Pp
-When using the nameserver,
+The function
 .Fn gethostbyname
 will search for the named host in the current domain and its parents
-unless the name ends in a dot.
-If the name contains no dot, and if the environment variable
-.Dq Ev HOSTALIASES
-contains the name of an alias file, the alias file will first be searched
-for an alias matching the input name.
-See
-.Xr hostname 7
-for the domain search procedure and the alias file format.
+using the search lookup semantics detailed in
+.Xr resolv.conf 5
+and
+.Xr hostname 7 .
+.Pp
+.Fn gethostbyname2
+is an advanced form of
+.Fn gethostbyname
+which allows lookups in address families other than
+.Dv AF_INET .
+Currently, the only supported address family besides
+.Dv AF_INET
+is
+.Dv AF_INET6 .
+.Pp
+The
+.Fn gethostbyaddr
+function will search for the specified address of length
+.Fa len
+in the address family
+.Fa af .
+The only address family currently supported is
+.Dv AF_INET .
 .Pp
 The
 .Fn sethostent
-function
-may be used to request the use of a connected
+function may be used to request the use of a connected
 .Tn TCP
 socket for queries.
 If the
@@ -127,7 +145,7 @@ If the
 flag is non-zero,
 this sets the option to send all queries to the name server using
 .Tn TCP
-and to retain the connection after each call to 
+and to retain the connection after each call to
 .Fn gethostbyname
 or
 .Fn gethostbyaddr .
@@ -137,17 +155,46 @@ datagrams.
 .Pp
 The
 .Fn endhostent
-function
-closes the
+function closes the
 .Tn TCP
 connection.
+.Pp
+The
+.Fn herror
+function prints an error message describing the failure.
+If its argument
+.Fa string
+is non-null,
+it is prepended to the message string and separated from it by a colon
+.Pq Ql \&:
+and a space.
+The error message is printed with a trailing newline.
+The contents of the error message is the same as that returned by
+.Fn hstrerror
+with argument
+.Fa h_errno .
+.Sh ENVIRONMENT
+.Bl -tag -width HOSTALIASES
+.It HOSTALIASES
+A file containing local host aliases.
+See
+.Xr hostname 7
+for more information.
+.It RES_OPTIONS
+A list of options to override the resolver's internal defaults.
+See
+.Xr resolver 3
+for more information.
+.El
 .Sh FILES
-.Bl -tag -width /etc/hosts -compact
+.Bl -tag -width /etc/resolv.conf -compact
 .It Pa /etc/hosts
+.It Pa /etc/resolv.conf
 .El
 .Sh DIAGNOSTICS
-Error return status from 
-.Fn gethostbyname
+Error return status from
+.Fn gethostbyname ,
+.Fn gethostbyname2 ,
 and
 .Fn gethostbyaddr
 is indicated by return of a null pointer.
@@ -155,15 +202,6 @@ The external integer
 .Va h_errno
 may then be checked to see whether this is a temporary failure
 or an invalid or unknown host.
-The routine
-.Fn herror
-can be used to print an error message describing the failure.
-If its argument
-.Fa string
-is
-.Pf non Dv -NULL ,
-it is printed, followed by a colon and a space.
-The error message is printed with a trailing newline.
 .Pp
 The variable
 .Va h_errno
@@ -180,75 +218,80 @@ A retry at some later time may succeed.
 Some unexpected server failure was encountered.
 This is a non-recoverable error.
 .It Dv NO_DATA
-The requested name is valid but does not have an IP address; 
-this is not a temporary error.  
+The requested name is valid but does not have an IP address;
+this is not a temporary error.
 This means that the name is known to the name server but there is no address
 associated with this name.
 Another type of request to the name server using this domain name
 will result in an answer;
 for example, a mail-forwarder may be registered for this domain.
+.It Dv NETDB_INTERNAL
+An internal error occurred.
+This may occur when an address family other than
+.Dv AF_INET
+or
+.Dv AF_INET6
+is specified or when a resource is unable to be allocated.
+.It Dv NETDB_SUCCESS
+The function completed successfully.
 .El
 .Sh SEE ALSO
+.Xr getaddrinfo 3 ,
+.Xr getnameinfo 3 ,
 .Xr resolver 3 ,
 .Xr hosts 5 ,
+.Xr resolv.conf 5 ,
 .Xr hostname 7 ,
 .Xr named 8
-.Sh CAVEAT
+.Sh HISTORY
 The
-.Fn gethostent
-function
-is defined, and
-.Fn sethostent
+.Fn herror
+function appeared in
+.Bx 4.3 .
+The
+.Fn endhostent ,
+.Fn gethostbyaddr ,
+.Fn gethostbyname ,
+.Fn gethostent ,
 and
-.Fn endhostent
-are redefined,
-when
-.Xr libc 3
-is built to use only the routines to lookup in
+.Fn sethostent
+functions appeared in
+.Bx 4.2 .
+.Sh CAVEATS
+If the search routines in
+.Xr resolv.conf 5
+decide to read the
 .Pa /etc/hosts
-and not the name server.
-.Pp
-The
+file,
 .Fn gethostent
-function
-reads the next line of
-.Pa /etc/hosts ,
-opening the file if necessary.
+and other functions will
+read the next line of the file,
+re-opening the file if necessary.
 .Pp
 The
 .Fn sethostent
-function
-opens and/or rewinds the file
+function opens and/or rewinds the file
 .Pa /etc/hosts .
 If the
 .Fa stayopen
-argument is non-zero,
-the file will not be closed after each call to
-.Fn gethostbyname
+argument is non-zero, the file will not be closed after each call to
+.Fn gethostbyname ,
+.Fn gethostbyname2 ,
 or
 .Fn gethostbyaddr .
 .Pp
 The
 .Fn endhostent
-function
-closes the file.
-.Sh HISTORY
-The
-.Fn herror
-function appeared in 
-.Bx 4.3 .
-The
-.Fn endhostent ,
-.Fn gethostbyaddr ,
-.Fn gethostbyname ,
-.Fn gethostent ,
-and
-.Fn sethostent
-functions appeared in
-.Bx 4.2 .
+function closes the file.
 .Sh BUGS
 These functions use static data storage;
 if the data is needed for future use, it should be
 copied before any subsequent calls overwrite it.
+.Pp
 Only the Internet
-address format is currently understood.
+address formats are currently understood.
+.Pp
+YP does not support any address families other than
+.Dv AF_INET
+and uses
+the traditional database format.