1 .\" Automatically generated by Pod::Man 2.27 (Pod::Simple 3.28)
4 .\" ========================================================================
5 .de Sp \" Vertical space (when we can't use .PP)
9 .de Vb \" Begin verbatim text
14 .de Ve \" End verbatim text
18 .\" Set up some character translations and predefined strings. \*(-- will
19 .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
20 .\" double quote, and \*(R" will give a right double quote. \*(C+ will
21 .\" give a nicer C++. Capital omega is used to do unbreakable dashes and
22 .\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff,
23 .\" nothing in troff, for use with C<>.
25 .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
29 . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
30 . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch
45 .\" Escape single quotes in literal strings from groff's Unicode transform.
49 .\" If the F register is turned on, we'll generate index entries on stderr for
50 .\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
51 .\" entries marked with X<> in POD. Of course, you'll have to process the
52 .\" output yourself in some meaningful fashion.
54 .\" Avoid warning from groff about undefined register 'F'.
58 .if \n(.g .if rF .nr rF 1
59 .if (\n(rF:(\n(.g==0)) \{
62 . tm Index:\\$1\t\\n%\t"\\$2"
72 .\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
73 .\" Fear. Run. Save yourself. No user-serviceable parts.
74 . \" fudge factors for nroff and troff
83 . ds #H ((1u-(\\\\n(.fu%2u))*.13m)
89 . \" simple accents for nroff and troff
99 . ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
100 . ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
101 . ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
102 . ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
103 . ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
104 . ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
106 . \" troff and (daisy-wheel) nroff accents
107 .ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
108 .ds 8 \h'\*(#H'\(*b\h'-\*(#H'
109 .ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
110 .ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
111 .ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
112 .ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
113 .ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
114 .ds ae a\h'-(\w'a'u*4/10)'e
115 .ds Ae A\h'-(\w'A'u*4/10)'E
116 . \" corrections for vroff
117 .if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
118 .if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
119 . \" for low resolution devices (crt and lpr)
120 .if \n(.H>23 .if \n(.V>19 \
133 .\" ========================================================================
135 .IX Title "BIO_s_accept 3"
136 .TH BIO_s_accept 3 "2015-03-19" "1.0.1m" "OpenSSL"
137 .\" For nroff, turn off justification. Always turn off hyphenation; it makes
138 .\" way too many mistakes in technical documents.
142 BIO_s_accept, BIO_set_accept_port, BIO_get_accept_port,
143 BIO_set_nbio_accept, BIO_set_accept_bios, BIO_set_bind_mode,
144 BIO_get_bind_mode, BIO_do_accept \- accept BIO
146 .IX Header "SYNOPSIS"
148 \& #include <openssl/bio.h>
150 \& BIO_METHOD *BIO_s_accept(void);
152 \& long BIO_set_accept_port(BIO *b, char *name);
153 \& char *BIO_get_accept_port(BIO *b);
155 \& BIO *BIO_new_accept(char *host_port);
157 \& long BIO_set_nbio_accept(BIO *b, int n);
158 \& long BIO_set_accept_bios(BIO *b, char *bio);
160 \& long BIO_set_bind_mode(BIO *b, long mode);
161 \& long BIO_get_bind_mode(BIO *b, long dummy);
163 \& #define BIO_BIND_NORMAL 0
164 \& #define BIO_BIND_REUSEADDR_IF_UNUSED 1
165 \& #define BIO_BIND_REUSEADDR 2
167 \& int BIO_do_accept(BIO *b);
170 .IX Header "DESCRIPTION"
171 \&\fIBIO_s_accept()\fR returns the accept \s-1BIO\s0 method. This is a wrapper
172 round the platform's \s-1TCP/IP\s0 socket accept routines.
174 Using accept BIOs, \s-1TCP/IP\s0 connections can be accepted and data
175 transferred using only \s-1BIO\s0 routines. In this way any platform
176 specific operations are hidden by the \s-1BIO\s0 abstraction.
178 Read and write operations on an accept \s-1BIO\s0 will perform I/O
179 on the underlying connection. If no connection is established
180 and the port (see below) is set up properly then the \s-1BIO\s0
181 waits for an incoming connection.
183 Accept BIOs support \fIBIO_puts()\fR but not \fIBIO_gets()\fR.
185 If the close flag is set on an accept \s-1BIO\s0 then any active
186 connection on that chain is shutdown and the socket closed when
187 the \s-1BIO\s0 is freed.
189 Calling \fIBIO_reset()\fR on a accept \s-1BIO\s0 will close any active
190 connection and reset the \s-1BIO\s0 into a state where it awaits another
193 \&\fIBIO_get_fd()\fR and \fIBIO_set_fd()\fR can be called to retrieve or set
194 the accept socket. See \fIBIO_s_fd\fR\|(3)
196 \&\fIBIO_set_accept_port()\fR uses the string \fBname\fR to set the accept
197 port. The port is represented as a string of the form \*(L"host:port\*(R",
198 where \*(L"host\*(R" is the interface to use and \*(L"port\*(R" is the port.
199 The host can be can be \*(L"*\*(R" which is interpreted as meaning
200 any interface; \*(L"port\*(R" has the same syntax
201 as the port specified in \fIBIO_set_conn_port()\fR for connect BIOs,
202 that is it can be a numerical port string or a string to lookup
203 using \fIgetservbyname()\fR and a string table.
205 \&\fIBIO_new_accept()\fR combines \fIBIO_new()\fR and \fIBIO_set_accept_port()\fR into
206 a single call: that is it creates a new accept \s-1BIO\s0 with port
209 \&\fIBIO_set_nbio_accept()\fR sets the accept socket to blocking mode
210 (the default) if \fBn\fR is 0 or non blocking mode if \fBn\fR is 1.
212 \&\fIBIO_set_accept_bios()\fR can be used to set a chain of BIOs which
213 will be duplicated and prepended to the chain when an incoming
214 connection is received. This is useful if, for example, a
215 buffering or \s-1SSL BIO\s0 is required for each connection. The
216 chain of BIOs must not be freed after this call, they will
217 be automatically freed when the accept \s-1BIO\s0 is freed.
219 \&\fIBIO_set_bind_mode()\fR and \fIBIO_get_bind_mode()\fR set and retrieve
220 the current bind mode. If \s-1BIO_BIND_NORMAL \s0(the default) is set
221 then another socket cannot be bound to the same port. If
222 \&\s-1BIO_BIND_REUSEADDR\s0 is set then other sockets can bind to the
223 same port. If \s-1BIO_BIND_REUSEADDR_IF_UNUSED\s0 is set then and
224 attempt is first made to use \s-1BIO_BIN_NORMAL,\s0 if this fails
225 and the port is not in use then a second attempt is made
226 using \s-1BIO_BIND_REUSEADDR.\s0
228 \&\fIBIO_do_accept()\fR serves two functions. When it is first
229 called, after the accept \s-1BIO\s0 has been setup, it will attempt
230 to create the accept socket and bind an address to it. Second
231 and subsequent calls to \fIBIO_do_accept()\fR will await an incoming
232 connection, or request a retry in non blocking mode.
235 When an accept \s-1BIO\s0 is at the end of a chain it will await an
236 incoming connection before processing I/O calls. When an accept
237 \&\s-1BIO\s0 is not at then end of a chain it passes I/O calls to the next
238 \&\s-1BIO\s0 in the chain.
240 When a connection is established a new socket \s-1BIO\s0 is created for
241 the connection and appended to the chain. That is the chain is now
242 accept\->socket. This effectively means that attempting I/O on
243 an initial accept socket will await an incoming connection then
246 If any additional BIOs have been set using \fIBIO_set_accept_bios()\fR
247 then they are placed between the socket and the accept \s-1BIO,\s0
248 that is the chain will be accept\->otherbios\->socket.
250 If a server wishes to process multiple connections (as is normally
251 the case) then the accept \s-1BIO\s0 must be made available for further
252 incoming connections. This can be done by waiting for a connection and
256 \& connection = BIO_pop(accept);
259 After this call \fBconnection\fR will contain a \s-1BIO\s0 for the recently
260 established connection and \fBaccept\fR will now be a single \s-1BIO\s0
261 again which can be used to await further incoming connections.
262 If no further connections will be accepted the \fBaccept\fR can
263 be freed using \fIBIO_free()\fR.
265 If only a single connection will be processed it is possible to
266 perform I/O using the accept \s-1BIO\s0 itself. This is often undesirable
267 however because the accept \s-1BIO\s0 will still accept additional incoming
268 connections. This can be resolved by using \fIBIO_pop()\fR (see above)
269 and freeing up the accept \s-1BIO\s0 after the initial connection.
271 If the underlying accept socket is non-blocking and \fIBIO_do_accept()\fR is
272 called to await an incoming connection it is possible for
273 \&\fIBIO_should_io_special()\fR with the reason \s-1BIO_RR_ACCEPT.\s0 If this happens
274 then it is an indication that an accept attempt would block: the application
275 should take appropriate action to wait until the underlying socket has
276 accepted a connection and retry the call.
278 \&\fIBIO_set_accept_port()\fR, \fIBIO_get_accept_port()\fR, \fIBIO_set_nbio_accept()\fR,
279 \&\fIBIO_set_accept_bios()\fR, \fIBIO_set_bind_mode()\fR, \fIBIO_get_bind_mode()\fR and
280 \&\fIBIO_do_accept()\fR are macros.
282 .IX Header "RETURN VALUES"
286 This example accepts two connections on port 4444, sends messages
287 down each and finally closes both down.
290 \& BIO *abio, *cbio, *cbio2;
291 \& ERR_load_crypto_strings();
292 \& abio = BIO_new_accept("4444");
294 \& /* First call to BIO_accept() sets up accept BIO */
295 \& if(BIO_do_accept(abio) <= 0) {
296 \& fprintf(stderr, "Error setting up accept\en");
297 \& ERR_print_errors_fp(stderr);
301 \& /* Wait for incoming connection */
302 \& if(BIO_do_accept(abio) <= 0) {
303 \& fprintf(stderr, "Error accepting connection\en");
304 \& ERR_print_errors_fp(stderr);
307 \& fprintf(stderr, "Connection 1 established\en");
308 \& /* Retrieve BIO for connection */
309 \& cbio = BIO_pop(abio);
310 \& BIO_puts(cbio, "Connection 1: Sending out Data on initial connection\en");
311 \& fprintf(stderr, "Sent out data on connection 1\en");
312 \& /* Wait for another connection */
313 \& if(BIO_do_accept(abio) <= 0) {
314 \& fprintf(stderr, "Error accepting connection\en");
315 \& ERR_print_errors_fp(stderr);
318 \& fprintf(stderr, "Connection 2 established\en");
319 \& /* Close accept BIO to refuse further connections */
320 \& cbio2 = BIO_pop(abio);
322 \& BIO_puts(cbio2, "Connection 2: Sending out Data on second\en");
323 \& fprintf(stderr, "Sent out data on connection 2\en");
325 \& BIO_puts(cbio, "Connection 1: Second connection established\en");
326 \& /* Close the two established connections */
331 .IX Header "SEE ALSO"