From 9a3026fb0a89a15ea2def3629cc13a69f1fc678c Mon Sep 17 00:00:00 2001 From: schwarze <> Date: Mon, 16 Feb 2015 16:42:14 +0000 Subject: third batch of perlpod(1) to mdoc(7) conversion --- src/lib/libcrypto/man/BIO_s_accept.3 | 279 +++++++++++++++++++++++++++++++++++ 1 file changed, 279 insertions(+) create mode 100644 src/lib/libcrypto/man/BIO_s_accept.3 (limited to 'src/lib/libcrypto/man/BIO_s_accept.3') diff --git a/src/lib/libcrypto/man/BIO_s_accept.3 b/src/lib/libcrypto/man/BIO_s_accept.3 new file mode 100644 index 0000000000..f5adfcc07c --- /dev/null +++ b/src/lib/libcrypto/man/BIO_s_accept.3 @@ -0,0 +1,279 @@ +.Dd $Mdocdate: February 16 2015 $ +.Dt BIO_S_ACCEPT 3 +.Os +.Sh NAME +.Nm BIO_s_accept , +.Nm BIO_set_accept_port , +.Nm BIO_get_accept_port , +.Nm BIO_new_accept , +.Nm BIO_set_nbio_accept , +.Nm BIO_set_accept_bios , +.Nm BIO_set_bind_mode , +.Nm BIO_get_bind_mode , +.Nm BIO_do_accept +.Nd accept BIO +.Sh SYNOPSIS +.In openssl/bio.h +.Ft BIO_METHOD * +.Fo BIO_s_accept +.Fa void +.Fc +.Ft long +.Fo BIO_set_accept_port +.Fa "BIO *b" +.Fa "char *name" +.Fc +.Ft char * +.Fo BIO_get_accept_port +.Fa "BIO *b" +.Fc +.Ft BIO * +.Fo BIO_new_accept +.Fa "char *host_port" +.Fc +.Ft long +.Fo BIO_set_nbio_accept +.Fa "BIO *b" +.Fa "int n" +.Fc +.Ft long +.Fo BIO_set_accept_bios +.Fa "BIO *b" +.Fa "char *bio" +.Fc +.Ft long +.Fo BIO_set_bind_mode +.Fa "BIO *b" +.Fa "long mode" +.Fc +.Ft long +.Fo BIO_get_bind_mode +.Fa "BIO *b" +.Fa "long dummy" +.Fc +.Fd #define BIO_BIND_NORMAL 0 +.Fd #define BIO_BIND_REUSEADDR_IF_UNUSED 1 +.Fd #define BIO_BIND_REUSEADDR 2 +.Ft int +.Fo BIO_do_accept +.Fa "BIO *b" +.Fc +.Sh DESCRIPTION +.Fn BIO_s_accept +returns the accept BIO method. +This is a wrapper round the platform's TCP/IP socket accept routines. +.Pp +Using accept BIOs, TCP/IP connections can be accepted +and data transferred using only BIO routines. +In this way any platform specific operations +are hidden by the BIO abstraction. +.Pp +Read and write operations on an accept BIO +will perform I/O on the underlying connection. +If no connection is established and the port (see below) is set up +properly then the BIO waits for an incoming connection. +.Pp +Accept BIOs support +.Xr BIO_puts 3 +but not +.Xr BIO_gets 3 . +.Pp +If the close flag is set on an accept BIO, then any active +connection on that chain is shutdown and the socket closed when +the BIO is freed. +.Pp +Calling +.Xr BIO_reset 3 +on a accept BIO will close any active connection and reset the BIO +into a state where it awaits another incoming connection. +.Pp +.Xr BIO_get_fd 3 +and +.Xr BIO_set_fd 3 +can be called to retrieve or set the accept socket. +See +.Xr BIO_s_fd 3 . +.Pp +.Fn BIO_set_accept_port +uses the string +.Fa name +to set the accept port. +The port is represented as a string of the form +.Ar host : Ns Ar port , +where +.Ar host +is the interface to use and +.Ar port +is the port. +Either or both values can be +.Qq * +which is interpreted as meaning any interface or port respectively. +.Ar port +has the same syntax as the port specified in +.Xr BIO_set_conn_port 3 +for connect BIOs. +It can be a numerical port string or a string to lookup using +.Xr getservbyname 3 +and a string table. +.Pp +.Fn BIO_new_accept +combines +.Xr BIO_new 3 +and +.Fn BIO_set_accept_port +into a single call. +It creates a new accept BIO with port +.Fa host_port . +.Pp +.Fn BIO_set_nbio_accept +sets the accept socket to blocking mode (the default) if +.Fa n +is 0 or non blocking mode if +.Fa n +is 1. +.Pp +.Fn BIO_set_accept_bios +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 SSL BIO +is required for each connection. +The chain of BIOs must not be freed after this call, +they will be automatically freed when the accept BIO is freed. +.Pp +.Fn BIO_set_bind_mode +and +.Fn BIO_get_bind_mode +set and retrieve the current bind mode. +If +.Dv BIO_BIND_NORMAL Pq the default +is set, then another socket cannot be bound to the same port. +If +.Dv BIO_BIND_REUSEADDR +is set, then other sockets can bind to the same port. +If +.Dv BIO_BIND_REUSEADDR_IF_UNUSED +is set, then an attempt is first made to use +.Dv BIO_BIN_NORMAL ; +if this fails and the port is not in use, +then a second attempt is made using +.Dv BIO_BIND_REUSEADDR . +.Pp +.Fn BIO_do_accept +serves two purposes. +When it is first called, after the accept BIO has been setup, +it will attempt to create the accept socket and bind an address to it. +Second and subsequent calls to +.Fn BIO_do_accept +will await an incoming connection, or request a retry in non blocking mode. +.Sh NOTES +When an accept BIO is at the end of a chain, it will await an +incoming connection before processing I/O calls. +When an accept BIO is not at then end of a chain, +it passes I/O calls to the next BIO in the chain. +.Pp +When a connection is established a new socket BIO 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 +.Fn BIO_set_accept_bios , +then they are placed between the socket and the accept BIO, +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 BIO must be made available for further +incoming connections. +This can be done by waiting for a connection and then calling: +.Pp +.Dl connection = BIO_pop(accept); +.Pp +After this call, +.Sy connection +will contain a BIO for the recently established connection and +.Sy accept +will now be a single BIO again which can be used +to await further incoming connections. +If no further connections will be accepted, the +.Sy accept +can be freed using +.Xr BIO_free 3 . +.Pp +If only a single connection will be processed, +it is possible to perform I/O using the accept BIO itself. +This is often undesirable however because the accept BIO +will still accept additional incoming connections. +This can be resolved by using +.Xr BIO_pop 3 +(see above) and freeing up the accept BIO after the initial connection. +.Pp +If the underlying accept socket is non-blocking and +.Fn BIO_do_accept +is called to await an incoming connection, it is possible for +.Xr BIO_should_io_special 3 +with the reason +.Dv BIO_RR_ACCEPT . +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 +.Fn BIO_set_accept_port , +.Fn BIO_get_accept_port , +.Fn BIO_set_nbio_accept , +.Fn BIO_set_accept_bios , +.Fn BIO_set_bind_mode , +.Fn BIO_get_bind_mode , +and +.Fn BIO_do_accept +are macros. +.Sh EXAMPLES +This example accepts two connections on port 4444, +sends messages down each and finally closes both down. +.Bd -literal -offset 2n +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); +.Ed -- cgit v1.2.3-55-g6feb