1LBER_SOCKBUF(3)            Library Functions Manual            LBER_SOCKBUF(3)
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NAME

6       ber_sockbuf_alloc,    ber_sockbuf_free,   ber_sockbuf_ctrl,   ber_sock‐
7       buf_add_io, ber_sockbuf_remove_io, Sockbuf_IO - OpenLDAP LBER  I/O  in‐
8       frastructure
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LIBRARY

11       OpenLDAP LBER (liblber, -llber)
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SYNOPSIS

14       #include <lber.h>
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16       Sockbuf *ber_sockbuf_alloc( void );
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18       void ber_sockbuf_free(Sockbuf *sb);
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20       int ber_sockbuf_ctrl(Sockbuf *sb, int opt, void *arg);
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22       int  ber_sockbuf_add_io(Sockbuf  *sb, Sockbuf_IO *sbio, int layer, void
23       *arg);
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25       int ber_sockbuf_remove_io(Sockbuf *sb, Sockbuf_IO *sbio, int layer);
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27       typedef struct sockbuf_io_desc {
28       int sbiod_level;
29       Sockbuf *sbiod_sb;
30       Sockbuf_IO *sbiod_io;
31       void *sbiod_pvt;
32       struct sockbuf_io_desc *sbiod_next;
33       } Sockbuf_IO_Desc;
34
35       typedef struct sockbuf_io {
36       int (*sbi_setup)(Sockbuf_IO_Desc *sbiod, void *arg);
37       int (*sbi_remove)(Sockbuf_IO_Desc *sbiod);
38       int (*sbi_ctrl)(Sockbuf_IO_Desc *sbiod, int opt, void *arg);
39       ber_slen_t (*sbi_read)(Sockbuf_IO_Desc *sbiod, void *buf, ber_len_t len);
40       ber_slen_t (*sbi_write)(Sockbuf_IO_Desc *sbiod, void *buf, ber_len_t len);
41       int (*sbi_close)(Sockbuf_IO_Desc *sbiod);
42       } Sockbuf_IO;
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DESCRIPTION

46       These routines are used to manage the low  level  I/O  operations  per‐
47       formed  by  the  Lightweight BER library. They are called implicitly by
48       the other libraries and usually do not need to be called directly  from
49       applications.   The I/O framework is modularized and new transport lay‐
50       ers can be supported by appropriately defining a  Sockbuf_IO  structure
51       and  installing  it  onto  an existing Sockbuf.  Sockbuf structures are
52       allocated and  freed  by  ber_sockbuf_alloc()  and  ber_sockbuf_free(),
53       respectively.  The  ber_sockbuf_ctrl()  function is used to get and set
54       options related to a Sockbuf or to a specific I/O layer of the Sockbuf.
55       The ber_sockbuf_add_io() and ber_sockbuf_remove_io() functions are used
56       to add and remove specific I/O layers on a Sockbuf.
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58       Options for ber_sockbuf_ctrl() include:
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60       LBER_SB_OPT_HAS_IO
61              Takes a Sockbuf_IO * argument and returns 1 if the given handler
62              is installed on the Sockbuf, otherwise returns 0.
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64       LBER_SB_OPT_GET_FD
65              Retrieves  the  file  descriptor  associated to the Sockbuf; arg
66              must be a ber_socket_t *.  The return value will be 1 if a valid
67              descriptor was present, -1 otherwise.
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69       LBER_SB_OPT_SET_FD
70              Sets  the  file  descriptor  of  the  Sockbuf  to the descriptor
71              pointed to by arg; arg must be a  ber_socket_t  *.   The  return
72              value will always be 1.
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74       LBER_SB_OPT_SET_NONBLOCK
75              Toggles the non-blocking state of the file descriptor associated
76              to the Sockbuf.  arg should be NULL to disable and  non-NULL  to
77              enable  the  non-blocking state.  The return value will be 1 for
78              success, -1 otherwise.
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80       LBER_SB_OPT_DRAIN
81              Flush (read and discard) all available  input  on  the  Sockbuf.
82              The return value will be 1.
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84       LBER_SB_OPT_NEEDS_READ
85              Returns non-zero if input is waiting to be read.
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87       LBER_SB_OPT_NEEDS_WRITE
88              Returns non-zero if the Sockbuf is ready to be written.
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90       LBER_SB_OPT_GET_MAX_INCOMING
91              Returns  the  maximum  allowed  size of an incoming message; arg
92              must be a ber_len_t *.  The return value will be 1.
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94       LBER_SB_OPT_SET_MAX_INCOMING
95              Sets the maximum allowed size of an incoming message;  arg  must
96              be a ber_len_t *.  The return value will be 1.
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99       Options not in this list will be passed down to each Sockbuf_IO handler
100       in turn until one of them processes it. If the option  is  not  handled
101       ber_sockbuf_ctrl() will return 0.
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103
104       Multiple  Sockbuf_IO handlers can be stacked in multiple layers to pro‐
105       vide various functionality.  Currently defined layers include
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107       LBER_SBIOD_LEVEL_PROVIDER
108              the lowest layer, talking directly to a network
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110       LBER_SBIOD_LEVEL_TRANSPORT
111              an intermediate layer
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113       LBER_SBIOD_LEVEL_APPLICATION
114              a higher layer
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116       Currently defined Sockbuf_IO handlers in liblber include
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118       ber_sockbuf_io_tcp
119              The default stream-oriented provider
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121       ber_sockbuf_io_fd
122              A stream-oriented provider for local IPC sockets
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124       ber_sockbuf_io_dgram
125              A datagram-oriented provider. This handler is  only  present  if
126              the liblber library was built with LDAP_CONNECTIONLESS defined.
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128       ber_sockbuf_io_readahead
129              A buffering layer, usually used with a datagram provider to hide
130              the datagram semantics from upper layers.
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132       ber_sockbuf_io_debug
133              A generic handler that outputs hex dumps of  all  traffic.  This
134              handler  may  be  inserted multiple times at arbitrary layers to
135              show the flow of data between other handlers.
136
137       Additional handlers may be present in libldap if support for  them  was
138       enabled:
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140       ldap_pvt_sockbuf_io_sasl
141              An application layer handler for SASL encoding/decoding.
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143       sb_tls_sbio
144              A  transport  layer  handler for SSL/TLS encoding/decoding. Note
145              that this handler is private to the library and is  not  exposed
146              in the API.
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148       The  provided  handlers are all instantiated implicitly by libldap, and
149       applications generally will not need to directly manipulate them.
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151

SEE ALSO

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

157       OpenLDAP Software is developed and maintained by The  OpenLDAP  Project
158       <http://www.openldap.org/>.  OpenLDAP Software is derived from the Uni‐
159       versity of Michigan LDAP 3.3 Release.
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163OpenLDAP 2.4.47                   2018/12/19                   LBER_SOCKBUF(3)
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