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Diffstat (limited to 'doc/crypto/BIO_s_accept.pod')
| -rw-r--r-- | doc/crypto/BIO_s_accept.pod | 195 |
1 files changed, 0 insertions, 195 deletions
diff --git a/doc/crypto/BIO_s_accept.pod b/doc/crypto/BIO_s_accept.pod deleted file mode 100644 index 560c1128efe0..000000000000 --- a/doc/crypto/BIO_s_accept.pod +++ /dev/null @@ -1,195 +0,0 @@ -=pod - -=head1 NAME - -BIO_s_accept, BIO_set_accept_port, BIO_get_accept_port, BIO_new_accept, -BIO_set_nbio_accept, BIO_set_accept_bios, BIO_set_bind_mode, -BIO_get_bind_mode, BIO_do_accept - accept BIO - -=head1 SYNOPSIS - - #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); - -=head1 DESCRIPTION - -BIO_s_accept() returns the accept BIO method. This is a wrapper -round the platform's TCP/IP socket accept routines. - -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. - -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. - -Accept BIOs support BIO_puts() but not BIO_gets(). - -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. - -Calling BIO_reset() on a accept BIO will close any active -connection and reset the BIO into a state where it awaits another -incoming connection. - -BIO_get_fd() and BIO_set_fd() can be called to retrieve or set -the accept socket. See L<BIO_s_fd(3)|BIO_s_fd(3)> - -BIO_set_accept_port() uses the string B<name> to set the accept -port. The port is represented as a string of the form "host:port", -where "host" is the interface to use and "port" is the port. -The host can be can be "*" which is interpreted as meaning -any interface; "port" has the same syntax -as the port specified in BIO_set_conn_port() for connect BIOs, -that is it can be a numerical port string or a string to lookup -using getservbyname() and a string table. - -BIO_new_accept() combines BIO_new() and BIO_set_accept_port() into -a single call: that is it creates a new accept BIO with port -B<host_port>. - -BIO_set_nbio_accept() sets the accept socket to blocking mode -(the default) if B<n> is 0 or non blocking mode if B<n> is 1. - -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. - -BIO_set_bind_mode() and BIO_get_bind_mode() set and retrieve -the current bind mode. If BIO_BIND_NORMAL (the default) is set -then another socket cannot be bound to the same port. If -BIO_BIND_REUSEADDR is set then other sockets can bind to the -same port. If BIO_BIND_REUSEADDR_IF_UNUSED is set then and -attempt is first made to use BIO_BIN_NORMAL, if this fails -and the port is not in use then a second attempt is made -using BIO_BIND_REUSEADDR. - -BIO_do_accept() serves two functions. 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 BIO_do_accept() will await an incoming -connection, or request a retry in non blocking mode. - -=head1 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. - -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. - -If any additional BIOs have been set using BIO_set_accept_bios() -then they are placed between the socket and the accept BIO, -that is the chain will be accept->otherbios->socket. - -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: - - connection = BIO_pop(accept); - -After this call B<connection> will contain a BIO for the recently -established connection and B<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 B<accept> can -be freed using BIO_free(). - -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 BIO_pop() (see above) -and freeing up the accept BIO after the initial connection. - -If the underlying accept socket is non-blocking and BIO_do_accept() is -called to await an incoming connection it is possible for -BIO_should_io_special() with the reason 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. - -BIO_set_accept_port(), BIO_get_accept_port(), BIO_set_nbio_accept(), -BIO_set_accept_bios(), BIO_set_bind_mode(), BIO_get_bind_mode() and -BIO_do_accept() are macros. - -=head1 RETURN VALUES - -TBA - -=head1 EXAMPLE - -This example accepts two connections on port 4444, sends messages -down each and finally closes both down. - - 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\n"); - ERR_print_errors_fp(stderr); - exit(0); - } - - /* Wait for incoming connection */ - if(BIO_do_accept(abio) <= 0) { - fprintf(stderr, "Error accepting connection\n"); - ERR_print_errors_fp(stderr); - exit(0); - } - fprintf(stderr, "Connection 1 established\n"); - /* Retrieve BIO for connection */ - cbio = BIO_pop(abio); - BIO_puts(cbio, "Connection 1: Sending out Data on initial connection\n"); - fprintf(stderr, "Sent out data on connection 1\n"); - /* Wait for another connection */ - if(BIO_do_accept(abio) <= 0) { - fprintf(stderr, "Error accepting connection\n"); - ERR_print_errors_fp(stderr); - exit(0); - } - fprintf(stderr, "Connection 2 established\n"); - /* Close accept BIO to refuse further connections */ - cbio2 = BIO_pop(abio); - BIO_free(abio); - BIO_puts(cbio2, "Connection 2: Sending out Data on second\n"); - fprintf(stderr, "Sent out data on connection 2\n"); - - BIO_puts(cbio, "Connection 1: Second connection established\n"); - /* Close the two established connections */ - BIO_free(cbio); - BIO_free(cbio2); - -=head1 SEE ALSO - -TBA |