diff --git a/lib/dns/include/dns/view.h b/lib/dns/include/dns/view.h new file mode 100644 index 0000000000..2beda476ce --- /dev/null +++ b/lib/dns/include/dns/view.h @@ -0,0 +1,88 @@ +/* + * Copyright (C) 1999 Internet Software Consortium. + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS + * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE + * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL + * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR + * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS + * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS + * SOFTWARE. + */ + +#ifndef DNS_VIEW_H +#define DNS_VIEW_H 1 + +/***** + ***** Module Info + *****/ + +/* + * DNS View + * + * XXX XXX + * + * MP: + * The module ensures appropriate synchronization of data structures it + * creates and manipulates, with the exception that the caller is + * responsible for the safe creation and destruction of view managers. + * + * Reliability: + * No anticipated impact. + * + * Resources: + * + * + * Security: + * No anticipated impact. + * + * Standards: + * None. + */ + +#include +#include +#include + +#include +#include + +ISC_LANG_BEGINDECLS + +struct dns_view { + /* Unlocked. */ + unsigned int magic; + isc_mem_t * mctx; + dns_rdataclass_t rdclass; + char * name; + dns_dbtable_t * dbtable; + dns_resolver_t * resolver; + isc_mutex_t lock; + /* Locked by lock. */ + unsigned int references; + /* Under owner's locking control. */ + ISC_LINK(struct dns_view) link; +}; + +#define DNS_VIEW_MAGIC 0x56696577 /* View. */ +#define DNS_VIEW_VALID(view) ((view) != NULL && \ + (view)->magic == DNS_VIEW_MAGIC) + +isc_result_t +dns_view_create(isc_mem_t *mctx, dns_rdataclass_t rdclass, char *name, + dns_resolver_t *resolver, dns_view_t **viewp); + +void +dns_view_attach(dns_view_t *source, dns_view_t **targetp); + +void +dns_view_detach(dns_view_t **viewp); + +ISC_LANG_ENDDECLS + +#endif /* DNS_VIEW_H */ diff --git a/lib/dns/view.c b/lib/dns/view.c new file mode 100644 index 0000000000..10b614f6b4 --- /dev/null +++ b/lib/dns/view.c @@ -0,0 +1,150 @@ +/* + * Copyright (C) 1999 Internet Software Consortium. + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS + * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE + * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL + * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR + * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS + * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS + * SOFTWARE. + */ + +#include + +#include + +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +#include "../isc/util.h" /* XXXRTH */ + +isc_result_t +dns_view_create(isc_mem_t *mctx, dns_rdataclass_t rdclass, char *name, + dns_resolver_t *resolver, dns_view_t **viewp) +{ + dns_view_t *view; + isc_result_t result; + + /* + * Create a view. + */ + + REQUIRE(name != NULL); + REQUIRE(viewp != NULL && *viewp == NULL); + + view = isc_mem_get(mctx, sizeof *view); + if (view == NULL) + return (ISC_R_NOMEMORY); + view->name = isc_mem_strdup(mctx, name); + if (view->name == NULL) { + result = ISC_R_NOMEMORY; + goto cleanup_view; + } + result = isc_mutex_init(&view->lock); + if (result != ISC_R_SUCCESS) { + UNEXPECTED_ERROR(__FILE__, __LINE__, + "isc_mutex_init() failed: %s", + isc_result_totext(result)); + result = ISC_R_UNEXPECTED; + goto cleanup_name; + } + view->dbtable = NULL; + result = dns_dbtable_create(mctx, rdclass, &view->dbtable); + if (result != ISC_R_SUCCESS) { + UNEXPECTED_ERROR(__FILE__, __LINE__, + "dns_dbtable_create() failed: %s", + isc_result_totext(result)); + result = ISC_R_UNEXPECTED; + goto cleanup_mutex; + } + view->resolver = NULL; + if (resolver != NULL) + dns_resolver_attach(resolver, &view->resolver); + + view->mctx = mctx; + view->rdclass = rdclass; + view->references = 1; + view->magic = DNS_VIEW_MAGIC; + + *viewp = view; + + return (ISC_R_SUCCESS); + + cleanup_mutex: + isc_mutex_destroy(&view->lock); + + cleanup_name: + isc_mem_free(mctx, view->name); + + cleanup_view: + isc_mem_put(mctx, view, sizeof *view); + + return (result); +} + +void +dns_view_attach(dns_view_t *source, dns_view_t **targetp) { + REQUIRE(DNS_VIEW_VALID(source)); + REQUIRE(targetp != NULL && *targetp == NULL); + + LOCK(&source->lock); + + INSIST(source->references > 0); + source->references++; + INSIST(source->references != 0); + + UNLOCK(&source->lock); + + *targetp = source; +} + +static inline void +destroy(dns_view_t *view) { + REQUIRE(!ISC_LINK_LINKED(view, link)); + + if (view->resolver != NULL) + dns_resolver_detach(&view->resolver); + dns_dbtable_detach(&view->dbtable); + isc_mutex_destroy(&view->lock); + isc_mem_free(view->mctx, view->name); + isc_mem_put(view->mctx, view, sizeof *view); +} + +void +dns_view_detach(dns_view_t **viewp) { + dns_view_t *view; + isc_boolean_t need_destroy = ISC_FALSE; + + REQUIRE(viewp != NULL); + view = *viewp; + REQUIRE(DNS_VIEW_VALID(view)); + + LOCK(&view->lock); + + INSIST(view->references > 0); + view->references--; + if (view->references == 0) + need_destroy = ISC_TRUE; + + UNLOCK(&view->lock); + + *viewp = NULL; + + if (need_destroy) + destroy(view); +}