diff options
Diffstat (limited to '')
-rw-r--r-- | libraries/librewrite/subst.c | 519 |
1 files changed, 519 insertions, 0 deletions
diff --git a/libraries/librewrite/subst.c b/libraries/librewrite/subst.c new file mode 100644 index 0000000..c3bdbd5 --- /dev/null +++ b/libraries/librewrite/subst.c @@ -0,0 +1,519 @@ +/* $OpenLDAP$ */ +/* This work is part of OpenLDAP Software <http://www.openldap.org/>. + * + * Copyright 2000-2018 The OpenLDAP Foundation. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted only as authorized by the OpenLDAP + * Public License. + * + * A copy of this license is available in the file LICENSE in the + * top-level directory of the distribution or, alternatively, at + * <http://www.OpenLDAP.org/license.html>. + */ +/* ACKNOWLEDGEMENT: + * This work was initially developed by Pierangelo Masarati for + * inclusion in OpenLDAP Software. + */ + +#include <portable.h> + +#include "rewrite-int.h" + +/* + * Compiles a substitution pattern + */ +struct rewrite_subst * +rewrite_subst_compile( + struct rewrite_info *info, + const char *str +) +{ + size_t subs_len; + struct berval *subs = NULL, *tmps; + struct rewrite_submatch *submatch = NULL; + + struct rewrite_subst *s = NULL; + + char *result, *begin, *p; + int nsub = 0, l; + + assert( info != NULL ); + assert( str != NULL ); + + result = strdup( str ); + if ( result == NULL ) { + return NULL; + } + + /* + * Take care of substitution string + */ + for ( p = begin = result, subs_len = 0; p[ 0 ] != '\0'; p++ ) { + + /* + * Keep only single escapes '%' + */ + if ( !IS_REWRITE_SUBMATCH_ESCAPE( p[ 0 ] ) ) { + continue; + } + + if ( IS_REWRITE_SUBMATCH_ESCAPE( p[ 1 ] ) ) { + /* Pull &p[1] over p, including the trailing '\0' */ + AC_MEMCPY((char *)p, &p[ 1 ], strlen( p ) ); + continue; + } + + tmps = ( struct berval * )realloc( subs, + sizeof( struct berval )*( nsub + 1 ) ); + if ( tmps == NULL ) { + goto cleanup; + } + subs = tmps; + + /* + * I think an `if l > 0' at runtime is better outside than + * inside a function call ... + */ + l = p - begin; + if ( l > 0 ) { + subs_len += l; + subs[ nsub ].bv_len = l; + subs[ nsub ].bv_val = malloc( l + 1 ); + if ( subs[ nsub ].bv_val == NULL ) { + goto cleanup; + } + AC_MEMCPY( subs[ nsub ].bv_val, begin, l ); + subs[ nsub ].bv_val[ l ] = '\0'; + } else { + subs[ nsub ].bv_val = NULL; + subs[ nsub ].bv_len = 0; + } + + /* + * Substitution pattern + */ + if ( isdigit( (unsigned char) p[ 1 ] ) ) { + struct rewrite_submatch *tmpsm; + int d = p[ 1 ] - '0'; + + /* + * Add a new value substitution scheme + */ + + tmpsm = ( struct rewrite_submatch * )realloc( submatch, + sizeof( struct rewrite_submatch )*( nsub + 1 ) ); + if ( tmpsm == NULL ) { + goto cleanup; + } + submatch = tmpsm; + submatch[ nsub ].ls_submatch = d; + + /* + * If there is no argument, use default + * (substitute substring as is) + */ + if ( p[ 2 ] != '{' ) { + submatch[ nsub ].ls_type = + REWRITE_SUBMATCH_ASIS; + submatch[ nsub ].ls_map = NULL; + begin = ++p + 1; + + } else { + struct rewrite_map *map; + + submatch[ nsub ].ls_type = + REWRITE_SUBMATCH_XMAP; + + map = rewrite_xmap_parse( info, + p + 3, (const char **)&begin ); + if ( map == NULL ) { + goto cleanup; + } + submatch[ nsub ].ls_map = map; + p = begin - 1; + } + + /* + * Map with args ... + */ + } else if ( p[ 1 ] == '{' ) { + struct rewrite_map *map; + struct rewrite_submatch *tmpsm; + + map = rewrite_map_parse( info, p + 2, + (const char **)&begin ); + if ( map == NULL ) { + goto cleanup; + } + p = begin - 1; + + /* + * Add a new value substitution scheme + */ + tmpsm = ( struct rewrite_submatch * )realloc( submatch, + sizeof( struct rewrite_submatch )*( nsub + 1 ) ); + if ( tmpsm == NULL ) { + rewrite_map_destroy( &map ); + goto cleanup; + } + submatch = tmpsm; + submatch[ nsub ].ls_type = + REWRITE_SUBMATCH_MAP_W_ARG; + submatch[ nsub ].ls_map = map; + + /* + * Escape '%' ... + */ + } else if ( p[ 1 ] == '%' ) { + AC_MEMCPY( &p[ 1 ], &p[ 2 ], strlen( &p[ 1 ] ) ); + continue; + + } else { + goto cleanup; + } + + nsub++; + } + + /* + * Last part of string + */ + tmps = (struct berval * )realloc( subs, sizeof( struct berval )*( nsub + 1 ) ); + if ( tmps == NULL ) { + /* + * XXX need to free the value subst stuff! + */ + free( subs ); + goto cleanup; + } + subs = tmps; + l = p - begin; + if ( l > 0 ) { + subs_len += l; + subs[ nsub ].bv_len = l; + subs[ nsub ].bv_val = malloc( l + 1 ); + if ( subs[ nsub ].bv_val == NULL ) { + goto cleanup; + } + AC_MEMCPY( subs[ nsub ].bv_val, begin, l ); + subs[ nsub ].bv_val[ l ] = '\0'; + } else { + subs[ nsub ].bv_val = NULL; + subs[ nsub ].bv_len = 0; + } + + s = calloc( sizeof( struct rewrite_subst ), 1 ); + if ( s == NULL ) { + goto cleanup; + } + + s->lt_subs_len = subs_len; + s->lt_subs = subs; + s->lt_num_submatch = nsub; + s->lt_submatch = submatch; + subs = NULL; + submatch = NULL; + +cleanup:; + if ( subs ) { + for ( l=0; l<nsub; l++ ) { + free( subs[nsub].bv_val ); + } + free( subs ); + } + if ( submatch ) { + for ( l=0; l<nsub; l++ ) { + free( submatch[nsub].ls_map ); + } + free( submatch ); + } + free( result ); + + return s; +} + +/* + * Copies the match referred to by submatch and fetched in string by match. + * Helper for rewrite_rule_apply. + */ +static int +submatch_copy( + struct rewrite_submatch *submatch, + const char *string, + const regmatch_t *match, + struct berval *val +) +{ + int c, l; + const char *s; + + assert( submatch != NULL ); + assert( submatch->ls_type == REWRITE_SUBMATCH_ASIS + || submatch->ls_type == REWRITE_SUBMATCH_XMAP ); + assert( string != NULL ); + assert( match != NULL ); + assert( val != NULL ); + assert( val->bv_val == NULL ); + + c = submatch->ls_submatch; + s = string + match[ c ].rm_so; + l = match[ c ].rm_eo - match[ c ].rm_so; + + val->bv_len = l; + val->bv_val = malloc( l + 1 ); + if ( val->bv_val == NULL ) { + return REWRITE_ERR; + } + + AC_MEMCPY( val->bv_val, s, l ); + val->bv_val[ l ] = '\0'; + + return REWRITE_SUCCESS; +} + +/* + * Substitutes a portion of rewritten string according to substitution + * pattern using submatches + */ +int +rewrite_subst_apply( + struct rewrite_info *info, + struct rewrite_op *op, + struct rewrite_subst *subst, + const char *string, + const regmatch_t *match, + struct berval *val +) +{ + struct berval *submatch = NULL; + char *res = NULL; + int n = 0, l, cl; + int rc = REWRITE_REGEXEC_OK; + + assert( info != NULL ); + assert( op != NULL ); + assert( subst != NULL ); + assert( string != NULL ); + assert( match != NULL ); + assert( val != NULL ); + + assert( val->bv_val == NULL ); + + val->bv_val = NULL; + val->bv_len = 0; + + /* + * Prepare room for submatch expansion + */ + if ( subst->lt_num_submatch > 0 ) { + submatch = calloc( sizeof( struct berval ), + subst->lt_num_submatch ); + if ( submatch == NULL ) { + return REWRITE_REGEXEC_ERR; + } + } + + /* + * Resolve submatches (simple subst, map expansion and so). + */ + for ( n = 0, l = 0; n < subst->lt_num_submatch; n++ ) { + struct berval key = { 0, NULL }; + + submatch[ n ].bv_val = NULL; + + /* + * Get key + */ + switch ( subst->lt_submatch[ n ].ls_type ) { + case REWRITE_SUBMATCH_ASIS: + case REWRITE_SUBMATCH_XMAP: + rc = submatch_copy( &subst->lt_submatch[ n ], + string, match, &key ); + if ( rc != REWRITE_SUCCESS ) { + rc = REWRITE_REGEXEC_ERR; + goto cleanup; + } + break; + + case REWRITE_SUBMATCH_MAP_W_ARG: + switch ( subst->lt_submatch[ n ].ls_map->lm_type ) { + case REWRITE_MAP_GET_OP_VAR: + case REWRITE_MAP_GET_SESN_VAR: + case REWRITE_MAP_GET_PARAM: + rc = REWRITE_SUCCESS; + break; + + default: + rc = rewrite_subst_apply( info, op, + subst->lt_submatch[ n ].ls_map->lm_subst, + string, match, &key); + } + + if ( rc != REWRITE_SUCCESS ) { + goto cleanup; + } + break; + + default: + Debug( LDAP_DEBUG_ANY, "Not Implemented\n", 0, 0, 0 ); + rc = REWRITE_ERR; + break; + } + + if ( rc != REWRITE_SUCCESS ) { + rc = REWRITE_REGEXEC_ERR; + goto cleanup; + } + + /* + * Resolve key + */ + switch ( subst->lt_submatch[ n ].ls_type ) { + case REWRITE_SUBMATCH_ASIS: + submatch[ n ] = key; + rc = REWRITE_SUCCESS; + break; + + case REWRITE_SUBMATCH_XMAP: + rc = rewrite_xmap_apply( info, op, + subst->lt_submatch[ n ].ls_map, + &key, &submatch[ n ] ); + free( key.bv_val ); + key.bv_val = NULL; + break; + + case REWRITE_SUBMATCH_MAP_W_ARG: + rc = rewrite_map_apply( info, op, + subst->lt_submatch[ n ].ls_map, + &key, &submatch[ n ] ); + free( key.bv_val ); + key.bv_val = NULL; + break; + + default: + /* + * When implemented, this might return the + * exit status of a rewrite context, + * which may include a stop, or an + * unwilling to perform + */ + rc = REWRITE_ERR; + break; + } + + if ( rc != REWRITE_SUCCESS ) { + rc = REWRITE_REGEXEC_ERR; + goto cleanup; + } + + /* + * Increment the length of the resulting string + */ + l += submatch[ n ].bv_len; + } + + /* + * Alloc result buffer + */ + l += subst->lt_subs_len; + res = malloc( l + 1 ); + if ( res == NULL ) { + rc = REWRITE_REGEXEC_ERR; + goto cleanup; + } + + /* + * Apply submatches (possibly resolved thru maps) + */ + for ( n = 0, cl = 0; n < subst->lt_num_submatch; n++ ) { + if ( subst->lt_subs[ n ].bv_val != NULL ) { + AC_MEMCPY( res + cl, subst->lt_subs[ n ].bv_val, + subst->lt_subs[ n ].bv_len ); + cl += subst->lt_subs[ n ].bv_len; + } + AC_MEMCPY( res + cl, submatch[ n ].bv_val, + submatch[ n ].bv_len ); + cl += submatch[ n ].bv_len; + } + if ( subst->lt_subs[ n ].bv_val != NULL ) { + AC_MEMCPY( res + cl, subst->lt_subs[ n ].bv_val, + subst->lt_subs[ n ].bv_len ); + cl += subst->lt_subs[ n ].bv_len; + } + res[ cl ] = '\0'; + + val->bv_val = res; + val->bv_len = l; + +cleanup:; + if ( submatch ) { + for ( ; --n >= 0; ) { + if ( submatch[ n ].bv_val ) { + free( submatch[ n ].bv_val ); + } + } + free( submatch ); + } + + return rc; +} + +/* + * frees data + */ +int +rewrite_subst_destroy( + struct rewrite_subst **psubst +) +{ + int n; + struct rewrite_subst *subst; + + assert( psubst != NULL ); + assert( *psubst != NULL ); + + subst = *psubst; + + for ( n = 0; n < subst->lt_num_submatch; n++ ) { + if ( subst->lt_subs[ n ].bv_val ) { + free( subst->lt_subs[ n ].bv_val ); + subst->lt_subs[ n ].bv_val = NULL; + } + + switch ( subst->lt_submatch[ n ].ls_type ) { + case REWRITE_SUBMATCH_ASIS: + break; + + case REWRITE_SUBMATCH_XMAP: + rewrite_xmap_destroy( &subst->lt_submatch[ n ].ls_map ); + break; + + case REWRITE_SUBMATCH_MAP_W_ARG: + rewrite_map_destroy( &subst->lt_submatch[ n ].ls_map ); + break; + + default: + break; + } + } + + free( subst->lt_submatch ); + subst->lt_submatch = NULL; + + /* last one */ + if ( subst->lt_subs[ n ].bv_val ) { + free( subst->lt_subs[ n ].bv_val ); + subst->lt_subs[ n ].bv_val = NULL; + } + + free( subst->lt_subs ); + subst->lt_subs = NULL; + + free( subst ); + *psubst = NULL; + + return 0; +} + |