lber-sockbuf(3) — Linux manual page


LBER_SOCKBUF(3)         Library Functions Manual         LBER_SOCKBUF(3)

NAME         top

       ber_sockbuf_alloc, ber_sockbuf_free, ber_sockbuf_ctrl,
       ber_sockbuf_add_io, ber_sockbuf_remove_io, Sockbuf_IO - OpenLDAP
       LBER I/O infrastructure

LIBRARY         top

       OpenLDAP LBER (liblber, -llber)

SYNOPSIS         top

       #include <lber.h>

       Sockbuf *ber_sockbuf_alloc( void );

       void ber_sockbuf_free(Sockbuf *sb);

       int ber_sockbuf_ctrl(Sockbuf *sb, int opt, void *arg);

       int ber_sockbuf_add_io(Sockbuf *sb, Sockbuf_IO *sbio, int layer,
       void *arg);

       int ber_sockbuf_remove_io(Sockbuf *sb, Sockbuf_IO *sbio, int

       typedef struct sockbuf_io_desc {
       int sbiod_level;
       Sockbuf *sbiod_sb;
       Sockbuf_IO *sbiod_io;
       void *sbiod_pvt;
       struct sockbuf_io_desc *sbiod_next;
       } Sockbuf_IO_Desc;

       typedef struct sockbuf_io {
       int (*sbi_setup)(Sockbuf_IO_Desc *sbiod, void *arg);
       int (*sbi_remove)(Sockbuf_IO_Desc *sbiod);
       int (*sbi_ctrl)(Sockbuf_IO_Desc *sbiod, int opt, void *arg);
       ber_slen_t (*sbi_read)(Sockbuf_IO_Desc *sbiod, void *buf, ber_len_t len);
       ber_slen_t (*sbi_write)(Sockbuf_IO_Desc *sbiod, void *buf, ber_len_t len);
       int (*sbi_close)(Sockbuf_IO_Desc *sbiod);
       } Sockbuf_IO;

DESCRIPTION         top

       These routines are used to manage the low level I/O operations
       performed by the Lightweight BER library. They are called
       implicitly by the other libraries and usually do not need to be
       called directly from applications.  The I/O framework is
       modularized and new transport layers can be supported by
       appropriately defining a Sockbuf_IO structure and installing it
       onto an existing Sockbuf.  Sockbuf structures are allocated and
       freed by ber_sockbuf_alloc() and ber_sockbuf_free(),
       respectively. The ber_sockbuf_ctrl() function is used to get and
       set options related to a Sockbuf or to a specific I/O layer of
       the Sockbuf.  The ber_sockbuf_add_io() and
       ber_sockbuf_remove_io() functions are used to add and remove
       specific I/O layers on a Sockbuf.

       Options for ber_sockbuf_ctrl() include:

              Takes a Sockbuf_IO * argument and returns 1 if the given
              handler is installed on the Sockbuf, otherwise returns 0.

              Retrieves the file descriptor associated to the Sockbuf;
              arg must be a ber_socket_t *.  The return value will be 1
              if a valid descriptor was present, -1 otherwise.

              Sets the file descriptor of the Sockbuf to the descriptor
              pointed to by arg; arg must be a ber_socket_t *.  The
              return value will always be 1.

              Toggles the non-blocking state of the file descriptor
              associated to the Sockbuf.  arg should be NULL to disable
              and non-NULL to enable the non-blocking state.  The return
              value will be 1 for success, -1 otherwise.

              Flush (read and discard) all available input on the
              Sockbuf.  The return value will be 1.

              Returns non-zero if input is waiting to be read.

              Returns non-zero if the Sockbuf is ready to be written.

              Returns the maximum allowed size of an incoming message;
              arg must be a ber_len_t *.  The return value will be 1.

              Sets the maximum allowed size of an incoming message; arg
              must be a ber_len_t *.  The return value will be 1.

       Options not in this list will be passed down to each Sockbuf_IO
       handler in turn until one of them processes it. If the option is
       not handled ber_sockbuf_ctrl() will return 0.

       Multiple Sockbuf_IO handlers can be stacked in multiple layers to
       provide various functionality.  Currently defined layers include

              the lowest layer, talking directly to a network

              an intermediate layer

              a higher layer

       Currently defined Sockbuf_IO handlers in liblber include

              The default stream-oriented provider

              A stream-oriented provider for local IPC sockets

              A datagram-oriented provider. This handler is only present
              if the liblber library was built with LDAP_CONNECTIONLESS

              A buffering layer, usually used with a datagram provider
              to hide the datagram semantics from upper layers.

              A generic handler that outputs hex dumps of all traffic.
              This handler may be inserted multiple times at arbitrary
              layers to show the flow of data between other handlers.

       Additional handlers may be present in libldap if support for them
       was enabled:

              An application layer handler for SASL encoding/decoding.

              A transport layer handler for SSL/TLS encoding/decoding.
              Note that this handler is private to the library and is
              not exposed in the API.

       The provided handlers are all instantiated implicitly by libldap,
       and applications generally will not need to directly manipulate

SEE ALSO         top

       lber-decode(3), lber-encode(3), lber-types(3), ldap_get_option(3)


       OpenLDAP Software is developed and maintained by The OpenLDAP
       Project <>.  OpenLDAP Software is derived
       from the University of Michigan LDAP 3.3 Release.

COLOPHON         top

       This page is part of the OpenLDAP (an open source implementation
       of the Lightweight Directory Access Protocol) project.
       Information about the project can be found at 
       ⟨⟩.  If you have a bug report for this
       manual page, see ⟨⟩.  This page was
       obtained from the project's upstream Git repository
       ⟨⟩ on 2023-12-22.
       (At that time, the date of the most recent commit that was found
       in the repository was 2023-12-19.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
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       (which is not part of the original manual page), send a mail to

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Pages that refer to this page: lber-decode(3)lber-encode(3)ldap_open(3)