324 lines
12 KiB
Groff
324 lines
12 KiB
Groff
.\" Automatically generated by Pod::Man 2.25 (Pod::Simple 3.28)
|
|
.\"
|
|
.\" Standard preamble:
|
|
.\" ========================================================================
|
|
.de Sp \" Vertical space (when we can't use .PP)
|
|
.if t .sp .5v
|
|
.if n .sp
|
|
..
|
|
.de Vb \" Begin verbatim text
|
|
.ft CW
|
|
.nf
|
|
.ne \\$1
|
|
..
|
|
.de Ve \" End verbatim text
|
|
.ft R
|
|
.fi
|
|
..
|
|
.\" Set up some character translations and predefined strings. \*(-- will
|
|
.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
|
|
.\" double quote, and \*(R" will give a right double quote. \*(C+ will
|
|
.\" give a nicer C++. Capital omega is used to do unbreakable dashes and
|
|
.\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff,
|
|
.\" nothing in troff, for use with C<>.
|
|
.tr \(*W-
|
|
.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
|
|
.ie n \{\
|
|
. ds -- \(*W-
|
|
. ds PI pi
|
|
. if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
|
|
. if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch
|
|
. ds L" ""
|
|
. ds R" ""
|
|
. ds C` ""
|
|
. ds C' ""
|
|
'br\}
|
|
.el\{\
|
|
. ds -- \|\(em\|
|
|
. ds PI \(*p
|
|
. ds L" ``
|
|
. ds R" ''
|
|
'br\}
|
|
.\"
|
|
.\" Escape single quotes in literal strings from groff's Unicode transform.
|
|
.ie \n(.g .ds Aq \(aq
|
|
.el .ds Aq '
|
|
.\"
|
|
.\" If the F register is turned on, we'll generate index entries on stderr for
|
|
.\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
|
|
.\" entries marked with X<> in POD. Of course, you'll have to process the
|
|
.\" output yourself in some meaningful fashion.
|
|
.ie \nF \{\
|
|
. de IX
|
|
. tm Index:\\$1\t\\n%\t"\\$2"
|
|
..
|
|
. nr % 0
|
|
. rr F
|
|
.\}
|
|
.el \{\
|
|
. de IX
|
|
..
|
|
.\}
|
|
.\"
|
|
.\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
|
|
.\" Fear. Run. Save yourself. No user-serviceable parts.
|
|
. \" fudge factors for nroff and troff
|
|
.if n \{\
|
|
. ds #H 0
|
|
. ds #V .8m
|
|
. ds #F .3m
|
|
. ds #[ \f1
|
|
. ds #] \fP
|
|
.\}
|
|
.if t \{\
|
|
. ds #H ((1u-(\\\\n(.fu%2u))*.13m)
|
|
. ds #V .6m
|
|
. ds #F 0
|
|
. ds #[ \&
|
|
. ds #] \&
|
|
.\}
|
|
. \" simple accents for nroff and troff
|
|
.if n \{\
|
|
. ds ' \&
|
|
. ds ` \&
|
|
. ds ^ \&
|
|
. ds , \&
|
|
. ds ~ ~
|
|
. ds /
|
|
.\}
|
|
.if t \{\
|
|
. ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
|
|
. ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
|
|
. ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
|
|
. ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
|
|
. ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
|
|
. ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
|
|
.\}
|
|
. \" troff and (daisy-wheel) nroff accents
|
|
.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
|
|
.ds 8 \h'\*(#H'\(*b\h'-\*(#H'
|
|
.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
|
|
.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
|
|
.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
|
|
.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
|
|
.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
|
|
.ds ae a\h'-(\w'a'u*4/10)'e
|
|
.ds Ae A\h'-(\w'A'u*4/10)'E
|
|
. \" corrections for vroff
|
|
.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
|
|
.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
|
|
. \" for low resolution devices (crt and lpr)
|
|
.if \n(.H>23 .if \n(.V>19 \
|
|
\{\
|
|
. ds : e
|
|
. ds 8 ss
|
|
. ds o a
|
|
. ds d- d\h'-1'\(ga
|
|
. ds D- D\h'-1'\(hy
|
|
. ds th \o'bp'
|
|
. ds Th \o'LP'
|
|
. ds ae ae
|
|
. ds Ae AE
|
|
.\}
|
|
.rm #[ #] #H #V #F C
|
|
.\" ========================================================================
|
|
.\"
|
|
.IX Title "BIO_s_accept 3"
|
|
.TH BIO_s_accept 3 "2014-10-15" "1.0.1j" "OpenSSL"
|
|
.\" For nroff, turn off justification. Always turn off hyphenation; it makes
|
|
.\" way too many mistakes in technical documents.
|
|
.if n .ad l
|
|
.nh
|
|
.SH "NAME"
|
|
BIO_s_accept, BIO_set_accept_port, BIO_get_accept_port,
|
|
BIO_set_nbio_accept, BIO_set_accept_bios, BIO_set_bind_mode,
|
|
BIO_get_bind_mode, BIO_do_accept \- accept BIO
|
|
.SH "SYNOPSIS"
|
|
.IX Header "SYNOPSIS"
|
|
.Vb 1
|
|
\& #include <openssl/bio.h>
|
|
\&
|
|
\& BIO_METHOD *BIO_s_accept(void);
|
|
\&
|
|
\& long BIO_set_accept_port(BIO *b, char *name);
|
|
\& char *BIO_get_accept_port(BIO *b);
|
|
\&
|
|
\& BIO *BIO_new_accept(char *host_port);
|
|
\&
|
|
\& long BIO_set_nbio_accept(BIO *b, int n);
|
|
\& long BIO_set_accept_bios(BIO *b, char *bio);
|
|
\&
|
|
\& long BIO_set_bind_mode(BIO *b, long mode);
|
|
\& long BIO_get_bind_mode(BIO *b, long dummy);
|
|
\&
|
|
\& #define BIO_BIND_NORMAL 0
|
|
\& #define BIO_BIND_REUSEADDR_IF_UNUSED 1
|
|
\& #define BIO_BIND_REUSEADDR 2
|
|
\&
|
|
\& int BIO_do_accept(BIO *b);
|
|
.Ve
|
|
.SH "DESCRIPTION"
|
|
.IX Header "DESCRIPTION"
|
|
\&\fIBIO_s_accept()\fR returns the accept \s-1BIO\s0 method. This is a wrapper
|
|
round the platform's \s-1TCP/IP\s0 socket accept routines.
|
|
.PP
|
|
Using accept BIOs, \s-1TCP/IP\s0 connections can be accepted and data
|
|
transferred using only \s-1BIO\s0 routines. In this way any platform
|
|
specific operations are hidden by the \s-1BIO\s0 abstraction.
|
|
.PP
|
|
Read and write operations on an accept \s-1BIO\s0 will perform I/O
|
|
on the underlying connection. If no connection is established
|
|
and the port (see below) is set up properly then the \s-1BIO\s0
|
|
waits for an incoming connection.
|
|
.PP
|
|
Accept BIOs support \fIBIO_puts()\fR but not \fIBIO_gets()\fR.
|
|
.PP
|
|
If the close flag is set on an accept \s-1BIO\s0 then any active
|
|
connection on that chain is shutdown and the socket closed when
|
|
the \s-1BIO\s0 is freed.
|
|
.PP
|
|
Calling \fIBIO_reset()\fR on a accept \s-1BIO\s0 will close any active
|
|
connection and reset the \s-1BIO\s0 into a state where it awaits another
|
|
incoming connection.
|
|
.PP
|
|
\&\fIBIO_get_fd()\fR and \fIBIO_set_fd()\fR can be called to retrieve or set
|
|
the accept socket. See \fIBIO_s_fd\fR\|(3)
|
|
.PP
|
|
\&\fIBIO_set_accept_port()\fR uses the string \fBname\fR to set the accept
|
|
port. The port is represented as a string of the form \*(L"host:port\*(R",
|
|
where \*(L"host\*(R" is the interface to use and \*(L"port\*(R" is the port.
|
|
The host can be can be \*(L"*\*(R" which is interpreted as meaning
|
|
any interface; \*(L"port\*(R" has the same syntax
|
|
as the port specified in \fIBIO_set_conn_port()\fR for connect BIOs,
|
|
that is it can be a numerical port string or a string to lookup
|
|
using \fIgetservbyname()\fR and a string table.
|
|
.PP
|
|
\&\fIBIO_new_accept()\fR combines \fIBIO_new()\fR and \fIBIO_set_accept_port()\fR into
|
|
a single call: that is it creates a new accept \s-1BIO\s0 with port
|
|
\&\fBhost_port\fR.
|
|
.PP
|
|
\&\fIBIO_set_nbio_accept()\fR sets the accept socket to blocking mode
|
|
(the default) if \fBn\fR is 0 or non blocking mode if \fBn\fR is 1.
|
|
.PP
|
|
\&\fIBIO_set_accept_bios()\fR can be used to set a chain of BIOs which
|
|
will be duplicated and prepended to the chain when an incoming
|
|
connection is received. This is useful if, for example, a
|
|
buffering or \s-1SSL\s0 \s-1BIO\s0 is required for each connection. The
|
|
chain of BIOs must not be freed after this call, they will
|
|
be automatically freed when the accept \s-1BIO\s0 is freed.
|
|
.PP
|
|
\&\fIBIO_set_bind_mode()\fR and \fIBIO_get_bind_mode()\fR set and retrieve
|
|
the current bind mode. If \s-1BIO_BIND_NORMAL\s0 (the default) is set
|
|
then another socket cannot be bound to the same port. If
|
|
\&\s-1BIO_BIND_REUSEADDR\s0 is set then other sockets can bind to the
|
|
same port. If \s-1BIO_BIND_REUSEADDR_IF_UNUSED\s0 is set then and
|
|
attempt is first made to use \s-1BIO_BIN_NORMAL\s0, if this fails
|
|
and the port is not in use then a second attempt is made
|
|
using \s-1BIO_BIND_REUSEADDR\s0.
|
|
.PP
|
|
\&\fIBIO_do_accept()\fR serves two functions. When it is first
|
|
called, after the accept \s-1BIO\s0 has been setup, it will attempt
|
|
to create the accept socket and bind an address to it. Second
|
|
and subsequent calls to \fIBIO_do_accept()\fR will await an incoming
|
|
connection, or request a retry in non blocking mode.
|
|
.SH "NOTES"
|
|
.IX Header "NOTES"
|
|
When an accept \s-1BIO\s0 is at the end of a chain it will await an
|
|
incoming connection before processing I/O calls. When an accept
|
|
\&\s-1BIO\s0 is not at then end of a chain it passes I/O calls to the next
|
|
\&\s-1BIO\s0 in the chain.
|
|
.PP
|
|
When a connection is established a new socket \s-1BIO\s0 is created for
|
|
the connection and appended to the chain. That is the chain is now
|
|
accept\->socket. This effectively means that attempting I/O on
|
|
an initial accept socket will await an incoming connection then
|
|
perform I/O on it.
|
|
.PP
|
|
If any additional BIOs have been set using \fIBIO_set_accept_bios()\fR
|
|
then they are placed between the socket and the accept \s-1BIO\s0,
|
|
that is the chain will be accept\->otherbios\->socket.
|
|
.PP
|
|
If a server wishes to process multiple connections (as is normally
|
|
the case) then the accept \s-1BIO\s0 must be made available for further
|
|
incoming connections. This can be done by waiting for a connection and
|
|
then calling:
|
|
.PP
|
|
.Vb 1
|
|
\& connection = BIO_pop(accept);
|
|
.Ve
|
|
.PP
|
|
After this call \fBconnection\fR will contain a \s-1BIO\s0 for the recently
|
|
established connection and \fBaccept\fR will now be a single \s-1BIO\s0
|
|
again which can be used to await further incoming connections.
|
|
If no further connections will be accepted the \fBaccept\fR can
|
|
be freed using \fIBIO_free()\fR.
|
|
.PP
|
|
If only a single connection will be processed it is possible to
|
|
perform I/O using the accept \s-1BIO\s0 itself. This is often undesirable
|
|
however because the accept \s-1BIO\s0 will still accept additional incoming
|
|
connections. This can be resolved by using \fIBIO_pop()\fR (see above)
|
|
and freeing up the accept \s-1BIO\s0 after the initial connection.
|
|
.PP
|
|
If the underlying accept socket is non-blocking and \fIBIO_do_accept()\fR is
|
|
called to await an incoming connection it is possible for
|
|
\&\fIBIO_should_io_special()\fR with the reason \s-1BIO_RR_ACCEPT\s0. If this happens
|
|
then it is an indication that an accept attempt would block: the application
|
|
should take appropriate action to wait until the underlying socket has
|
|
accepted a connection and retry the call.
|
|
.PP
|
|
\&\fIBIO_set_accept_port()\fR, \fIBIO_get_accept_port()\fR, \fIBIO_set_nbio_accept()\fR,
|
|
\&\fIBIO_set_accept_bios()\fR, \fIBIO_set_bind_mode()\fR, \fIBIO_get_bind_mode()\fR and
|
|
\&\fIBIO_do_accept()\fR are macros.
|
|
.SH "RETURN VALUES"
|
|
.IX Header "RETURN VALUES"
|
|
\&\s-1TBA\s0
|
|
.SH "EXAMPLE"
|
|
.IX Header "EXAMPLE"
|
|
This example accepts two connections on port 4444, sends messages
|
|
down each and finally closes both down.
|
|
.PP
|
|
.Vb 3
|
|
\& BIO *abio, *cbio, *cbio2;
|
|
\& ERR_load_crypto_strings();
|
|
\& abio = BIO_new_accept("4444");
|
|
\&
|
|
\& /* First call to BIO_accept() sets up accept BIO */
|
|
\& if(BIO_do_accept(abio) <= 0) {
|
|
\& fprintf(stderr, "Error setting up accept\en");
|
|
\& ERR_print_errors_fp(stderr);
|
|
\& exit(0);
|
|
\& }
|
|
\&
|
|
\& /* Wait for incoming connection */
|
|
\& if(BIO_do_accept(abio) <= 0) {
|
|
\& fprintf(stderr, "Error accepting connection\en");
|
|
\& ERR_print_errors_fp(stderr);
|
|
\& exit(0);
|
|
\& }
|
|
\& fprintf(stderr, "Connection 1 established\en");
|
|
\& /* Retrieve BIO for connection */
|
|
\& cbio = BIO_pop(abio);
|
|
\& BIO_puts(cbio, "Connection 1: Sending out Data on initial connection\en");
|
|
\& fprintf(stderr, "Sent out data on connection 1\en");
|
|
\& /* Wait for another connection */
|
|
\& if(BIO_do_accept(abio) <= 0) {
|
|
\& fprintf(stderr, "Error accepting connection\en");
|
|
\& ERR_print_errors_fp(stderr);
|
|
\& exit(0);
|
|
\& }
|
|
\& fprintf(stderr, "Connection 2 established\en");
|
|
\& /* Close accept BIO to refuse further connections */
|
|
\& cbio2 = BIO_pop(abio);
|
|
\& BIO_free(abio);
|
|
\& BIO_puts(cbio2, "Connection 2: Sending out Data on second\en");
|
|
\& fprintf(stderr, "Sent out data on connection 2\en");
|
|
\&
|
|
\& BIO_puts(cbio, "Connection 1: Second connection established\en");
|
|
\& /* Close the two established connections */
|
|
\& BIO_free(cbio);
|
|
\& BIO_free(cbio2);
|
|
.Ve
|
|
.SH "SEE ALSO"
|
|
.IX Header "SEE ALSO"
|
|
\&\s-1TBA\s0
|