1 .\" Automatically generated by Pod::Man 2.16 (Pod::Simple 3.05)
4 .\" ========================================================================
5 .de Sh \" Subsection heading
13 .de Sp \" Vertical space (when we can't use .PP)
17 .de Vb \" Begin verbatim text
22 .de Ve \" End verbatim text
26 .\" Set up some character translations and predefined strings. \*(-- will
27 .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
28 .\" double quote, and \*(R" will give a right double quote. \*(C+ will
29 .\" give a nicer C++. Capital omega is used to do unbreakable dashes and
30 .\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff,
31 .\" nothing in troff, for use with C<>.
33 .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
37 . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
38 . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch
51 .\" Escape single quotes in literal strings from groff's Unicode transform.
55 .\" If the F register is turned on, we'll generate index entries on stderr for
56 .\" titles (.TH), headers (.SH), subsections (.Sh), items (.Ip), and index
57 .\" entries marked with X<> in POD. Of course, you'll have to process the
58 .\" output yourself in some meaningful fashion.
61 . tm Index:\\$1\t\\n%\t"\\$2"
71 .\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
72 .\" Fear. Run. Save yourself. No user-serviceable parts.
73 . \" fudge factors for nroff and troff
82 . ds #H ((1u-(\\\\n(.fu%2u))*.13m)
88 . \" simple accents for nroff and troff
98 . ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
99 . ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
100 . ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
101 . ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
102 . ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
103 . ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
105 . \" troff and (daisy-wheel) nroff accents
106 .ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
107 .ds 8 \h'\*(#H'\(*b\h'-\*(#H'
108 .ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
109 .ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
110 .ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
111 .ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
112 .ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
113 .ds ae a\h'-(\w'a'u*4/10)'e
114 .ds Ae A\h'-(\w'A'u*4/10)'E
115 . \" corrections for vroff
116 .if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
117 .if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
118 . \" for low resolution devices (crt and lpr)
119 .if \n(.H>23 .if \n(.V>19 \
132 .\" ========================================================================
134 .IX Title "BIO_s_accept 3"
135 .TH BIO_s_accept 3 "2009-11-06" "0.9.8l" "OpenSSL"
136 .\" For nroff, turn off justification. Always turn off hyphenation; it makes
137 .\" way too many mistakes in technical documents.
141 BIO_s_accept, BIO_set_accept_port, BIO_get_accept_port,
142 BIO_set_nbio_accept, BIO_set_accept_bios, BIO_set_bind_mode,
143 BIO_get_bind_mode, BIO_do_accept \- accept BIO
145 .IX Header "SYNOPSIS"
147 \& #include <openssl/bio.h>
149 \& BIO_METHOD *BIO_s_accept(void);
151 \& long BIO_set_accept_port(BIO *b, char *name);
152 \& char *BIO_get_accept_port(BIO *b);
154 \& BIO *BIO_new_accept(char *host_port);
156 \& long BIO_set_nbio_accept(BIO *b, int n);
157 \& long BIO_set_accept_bios(BIO *b, char *bio);
159 \& long BIO_set_bind_mode(BIO *b, long mode);
160 \& long BIO_get_bind_mode(BIO *b, long dummy);
162 \& #define BIO_BIND_NORMAL 0
163 \& #define BIO_BIND_REUSEADDR_IF_UNUSED 1
164 \& #define BIO_BIND_REUSEADDR 2
166 \& int BIO_do_accept(BIO *b);
169 .IX Header "DESCRIPTION"
170 \&\fIBIO_s_accept()\fR returns the accept \s-1BIO\s0 method. This is a wrapper
171 round the platform's \s-1TCP/IP\s0 socket accept routines.
173 Using accept BIOs, \s-1TCP/IP\s0 connections can be accepted and data
174 transferred using only \s-1BIO\s0 routines. In this way any platform
175 specific operations are hidden by the \s-1BIO\s0 abstraction.
177 Read and write operations on an accept \s-1BIO\s0 will perform I/O
178 on the underlying connection. If no connection is established
179 and the port (see below) is set up properly then the \s-1BIO\s0
180 waits for an incoming connection.
182 Accept BIOs support \fIBIO_puts()\fR but not \fIBIO_gets()\fR.
184 If the close flag is set on an accept \s-1BIO\s0 then any active
185 connection on that chain is shutdown and the socket closed when
186 the \s-1BIO\s0 is freed.
188 Calling \fIBIO_reset()\fR on a accept \s-1BIO\s0 will close any active
189 connection and reset the \s-1BIO\s0 into a state where it awaits another
192 \&\fIBIO_get_fd()\fR and \fIBIO_set_fd()\fR can be called to retrieve or set
193 the accept socket. See \fIBIO_s_fd\fR\|(3)
195 \&\fIBIO_set_accept_port()\fR uses the string \fBname\fR to set the accept
196 port. The port is represented as a string of the form \*(L"host:port\*(R",
197 where \*(L"host\*(R" is the interface to use and \*(L"port\*(R" is the port.
198 Either or both values can be \*(L"*\*(R" which is interpreted as meaning
199 any interface or port respectively. \*(L"port\*(R" has the same syntax
200 as the port specified in \fIBIO_set_conn_port()\fR for connect BIOs,
201 that is it can be a numerical port string or a string to lookup
202 using \fIgetservbyname()\fR and a string table.
204 \&\fIBIO_new_accept()\fR combines \fIBIO_new()\fR and \fIBIO_set_accept_port()\fR into
205 a single call: that is it creates a new accept \s-1BIO\s0 with port
208 \&\fIBIO_set_nbio_accept()\fR sets the accept socket to blocking mode
209 (the default) if \fBn\fR is 0 or non blocking mode if \fBn\fR is 1.
211 \&\fIBIO_set_accept_bios()\fR can be used to set a chain of BIOs which
212 will be duplicated and prepended to the chain when an incoming
213 connection is received. This is useful if, for example, a
214 buffering or \s-1SSL\s0 \s-1BIO\s0 is required for each connection. The
215 chain of BIOs must not be freed after this call, they will
216 be automatically freed when the accept \s-1BIO\s0 is freed.
218 \&\fIBIO_set_bind_mode()\fR and \fIBIO_get_bind_mode()\fR set and retrieve
219 the current bind mode. If \s-1BIO_BIND_NORMAL\s0 (the default) is set
220 then another socket cannot be bound to the same port. If
221 \&\s-1BIO_BIND_REUSEADDR\s0 is set then other sockets can bind to the
222 same port. If \s-1BIO_BIND_REUSEADDR_IF_UNUSED\s0 is set then and
223 attempt is first made to use \s-1BIO_BIN_NORMAL\s0, if this fails
224 and the port is not in use then a second attempt is made
225 using \s-1BIO_BIND_REUSEADDR\s0.
227 \&\fIBIO_do_accept()\fR serves two functions. When it is first
228 called, after the accept \s-1BIO\s0 has been setup, it will attempt
229 to create the accept socket and bind an address to it. Second
230 and subsequent calls to \fIBIO_do_accept()\fR will await an incoming
231 connection, or request a retry in non blocking mode.
234 When an accept \s-1BIO\s0 is at the end of a chain it will await an
235 incoming connection before processing I/O calls. When an accept
236 \&\s-1BIO\s0 is not at then end of a chain it passes I/O calls to the next
237 \&\s-1BIO\s0 in the chain.
239 When a connection is established a new socket \s-1BIO\s0 is created for
240 the connection and appended to the chain. That is the chain is now
241 accept\->socket. This effectively means that attempting I/O on
242 an initial accept socket will await an incoming connection then
245 If any additional BIOs have been set using \fIBIO_set_accept_bios()\fR
246 then they are placed between the socket and the accept \s-1BIO\s0,
247 that is the chain will be accept\->otherbios\->socket.
249 If a server wishes to process multiple connections (as is normally
250 the case) then the accept \s-1BIO\s0 must be made available for further
251 incoming connections. This can be done by waiting for a connection and
255 \& connection = BIO_pop(accept);
258 After this call \fBconnection\fR will contain a \s-1BIO\s0 for the recently
259 established connection and \fBaccept\fR will now be a single \s-1BIO\s0
260 again which can be used to await further incoming connections.
261 If no further connections will be accepted the \fBaccept\fR can
262 be freed using \fIBIO_free()\fR.
264 If only a single connection will be processed it is possible to
265 perform I/O using the accept \s-1BIO\s0 itself. This is often undesirable
266 however because the accept \s-1BIO\s0 will still accept additional incoming
267 connections. This can be resolved by using \fIBIO_pop()\fR (see above)
268 and freeing up the accept \s-1BIO\s0 after the initial connection.
270 If the underlying accept socket is non-blocking and \fIBIO_do_accept()\fR is
271 called to await an incoming connection it is possible for
272 \&\fIBIO_should_io_special()\fR with the reason \s-1BIO_RR_ACCEPT\s0. If this happens
273 then it is an indication that an accept attempt would block: the application
274 should take appropriate action to wait until the underlying socket has
275 accepted a connection and retry the call.
277 \&\fIBIO_set_accept_port()\fR, \fIBIO_get_accept_port()\fR, \fIBIO_set_nbio_accept()\fR,
278 \&\fIBIO_set_accept_bios()\fR, \fIBIO_set_bind_mode()\fR, \fIBIO_get_bind_mode()\fR and
279 \&\fIBIO_do_accept()\fR are macros.
281 .IX Header "RETURN VALUES"
285 This example accepts two connections on port 4444, sends messages
286 down each and finally closes both down.
289 \& BIO *abio, *cbio, *cbio2;
290 \& ERR_load_crypto_strings();
291 \& abio = BIO_new_accept("4444");
293 \& /* First call to BIO_accept() sets up accept BIO */
294 \& if(BIO_do_accept(abio) <= 0) {
295 \& fprintf(stderr, "Error setting up accept\en");
296 \& ERR_print_errors_fp(stderr);
300 \& /* Wait for incoming connection */
301 \& if(BIO_do_accept(abio) <= 0) {
302 \& fprintf(stderr, "Error accepting connection\en");
303 \& ERR_print_errors_fp(stderr);
306 \& fprintf(stderr, "Connection 1 established\en");
307 \& /* Retrieve BIO for connection */
308 \& cbio = BIO_pop(abio);
309 \& BIO_puts(cbio, "Connection 1: Sending out Data on initial connection\en");
310 \& fprintf(stderr, "Sent out data on connection 1\en");
311 \& /* Wait for another connection */
312 \& if(BIO_do_accept(abio) <= 0) {
313 \& fprintf(stderr, "Error accepting connection\en");
314 \& ERR_print_errors_fp(stderr);
317 \& fprintf(stderr, "Connection 2 established\en");
318 \& /* Close accept BIO to refuse further connections */
319 \& cbio2 = BIO_pop(abio);
321 \& BIO_puts(cbio2, "Connection 2: Sending out Data on second\en");
322 \& fprintf(stderr, "Sent out data on connection 2\en");
324 \& BIO_puts(cbio, "Connection 1: Second connection established\en");
325 \& /* Close the two established connections */
330 .IX Header "SEE ALSO"