Reference

ldap_init_getfilter(3)

LDAP filter generating routines

Part of ldap_getfilter(3).

NAME

ldap_init_getfilter, ldap_init_getfilter_buf, ldap_getfilter_free, ldap_getfirstfilter, ldap_getnextfilter, ldap_build_filter - LDAP filter generating routines

SYNOPSIS

#include <ldap.h>


#define LDAP_FILT_MAXSIZ	1024
typedef struct ldap_filt_info {
        char                    *lfi_filter;
        char                    *lfi_desc;
        int                     lfi_scope;
        int                     lfi_isexact;
        struct ldap_filt_info   *lfi_next;
} LDAPFiltInfo;
typedef struct ldap_filt_list {
    char                        *lfl_tag;
    char                        *lfl_pattern;
    char                        *lfl_delims;
    LDAPFiltInfo                *lfl_ilist;
    struct ldap_filt_list       *lfl_next;
} LDAPFiltList;
typedef struct ldap_filt_desc {
        LDAPFiltList            *lfd_filtlist;
        LDAPFiltInfo            *lfd_curfip;
        LDAPFiltInfo            lfd_retfi;
        char                    lfd_filter[ LDAP_FILT_MAXSIZ ];
        char                    *lfd_curval;
        char                    *lfd_curvalcopy;
        char                    **lfd_curvalwords;
        char                    *lfd_filtprefix;
        char                    *lfd_filtsuffix;
} LDAPFiltDesc;

LDAPFiltDesc *ldap_init_getfilter( file ) char *file;

LDAPFiltDesc *ldap_init_getfilter_buf( buf, buflen )
char *buf;
long buflen;

ldap_getfilter_free( lfdp ) LDAPFiltDesc *lfdp;

LDAPFiltInfo *ldap_getfirstfilter(lfdp, tagpat, value)
LDAPFiltDesc *lfdp;
char *tagpat;
char *value;


LDAPFiltInfo *ldap_getnextfilter(lfdp)
LDAPFiltDesc *lfdp;

void ldap_setfilteraffixes(lfdp, prefix, suffix) LDAPFiltDesc *lfdp; char *prefix; char *suffix;

void ldap_build_filter( buf, buflen, pattern, prefix, suffix,
attr, value, valwords ) char *buf; unsigned long buflen; char *pattern; char *prefix; char *suffix; char *attr; char *value; char **valwords;

DESCRIPTION

These routines are used to generate filters to be used in ldap_search(3) or ldap_search_s(3). Either ldap_init_getfilter or ldap_init_getfilter_buf must be called prior to calling any of the other routines except ldap_build_filter.

ldap_init_getfilter() takes a file name as its only argument. The contents of the file must be a valid LDAP filter configuration file (see ldapfilter.conf(5)). If the file is successfully read, a pointer to an LDAPFiltDesc is returned. This is an opaque object that is passed in subsequent get filter calls.

ldap_init_getfilter_buf() reads from buf (whose length is buflen) the LDAP filter configuration information. buf must point to the contents of a valid LDAP filter configuration file (see ldapfilter.conf(5)). If the filter configuration information is successfully read, a pointer to an LDAPFiltDesc is returned. This is an opaque object that is passed in subsequent get filter calls.

ldap_getfilter_free() deallocates the memory consumed by ldap_init_getfilter. Once it is called, the LDAPFiltDesc is no longer valid and cannot be used again.

ldap_getfirstfilter() retrieves the first filter that is appropriate for value. Only filter sets that have tags that match the regular expession tagpat are considered. ldap_getfirstfilter returns a pointer to an LDAPFiltInfo structure, which contains a filter with value inserted as appropriate in lfi_filter, a text match description in lfi_desc, lfi_scope set to indicate the search scope, and lfi_isexact set to indicate the type of filter. NULL is returned if no matching filters are found. lfi_scope will be one of LDAP_SCOPE_BASE, LDAP_SCOPE_ONELEVEL, or LDAP_SCOPE_SUBTREE. lfi_isexact will be zero if the filter has any '~' or '*' characters in it and non-zero otherwise.

ldap_getnextfilter() retrieves the next appropriate filter in the filter set that was determined when ldap_getfirstfilter was called. It returns NULL when the list has been exhausted.

ldap_setfilteraffixes() sets a prefix to be prepended and a suffix to be appended to all filters returned in the future.

ldap_build_filter() constructs an LDAP search filter in buf. buflen is the size, in bytes, of the largest filter buf can hold. A pattern for the desired filter is passed in pattern. Where the string %a appears in the pattern it is replaced with attr. prefix is pre-pended to the resulting filter, and suffix is appended. Either can be NULL (in which case they are not used). value and valwords are used when the string %v appears in pattern. See ldapfilter.conf(5) for a description of how %v is handled.

ERRORS

NULL is returned by ldap_init_getfilter if there is an error reading file. NULL is returned by ldap_getfirstfilter and ldap_getnextfilter when there are no more appropriate filters to return.

NOTES

The return values for all of these functions are declared in the <ldap.h> header file. Some routines may dynamically allocate memory which the caller must free using the supplied deallocator routines.

FILES

/etc/ldap/ldapfilter.conf

SEE ALSO

ldap(3), ldapfilter.conf(5)

ACKNOWLEDGEMENTS

OpenLDAP is developed and maintained by The OpenLDAP Project (http://www.openldap.org/). OpenLDAP is derived from University of Michigan LDAP 3.3 Release.

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