/**
* Determines if a subscription has been reduced and logs a message if it has.
*
* @param origSub [in] Original subscription
* @param currSub [in] Current subscription
* @param entity [in] Entity that reduced the subscription. Replaces the
* blank in the sentence "Subscription reduced by one or more
* _____".
* @retval 0 If and only if the original subscription equals the
* current subscription (i.e., the subscription has not been
* reduced)
*/
int logIfReduced(
const prod_class_t* const origSub,
const prod_class_t* const currSub,
const char* entity)
{
int wasReduced = !clss_eq(origSub, currSub);
if (wasReduced) {
/*
* The downstream LDM is not allowed to receive what it requested.
*/
char origStr[1984];
(void) s_prod_class(origStr, sizeof(origStr), origSub);
log_warning("Subscription reduced by one or more %s: %s -> %s", entity,
origStr, s_prod_class(NULL, 0, currSub));
}
return wasReduced;
}
hiya_reply_t*
hiya_6_svc(
prod_class_t *offered,
struct svc_req *rqstp)
{
const char* const pqfname = getQueuePath();
static hiya_reply_t reply;
SVCXPRT * const xprt = rqstp->rq_xprt;
struct sockaddr_in *upAddr = (struct sockaddr_in*) svc_getcaller(xprt);
const char *upName = hostbyaddr(upAddr);
int error;
int isPrimary;
unsigned int maxHereis;
static prod_class_t *accept;
/*
* Open the product-queue for writing. It will be closed by cleanup()
* during process termination.
*/
if (pq) {
(void) pq_close(pq);
pq = NULL;
}
error = pq_open(pqfname, PQ_DEFAULT, &pq);
if (error) {
err_log_and_free(ERR_NEW2(error, NULL,
"Couldn't open product-queue \"%s\" for writing: %s",
pqfname,
PQ_CORRUPT == error
? "The product-queue is inconsistent"
: strerror(error)), ERR_FAILURE);
svcerr_systemerr(xprt);
svc_destroy(xprt);
exit(error);
}
/* else */
error = down6_init(upName, upAddr, pqfname, pq);
if (error) {
uerror("Couldn't initialize downstream LDM");
svcerr_systemerr(xprt);
svc_destroy(xprt);
exit(error);
}
else {
uinfo("Downstream LDM initialized");
}
/*
* The previous "accept" is freed here -- rather than freeing the
* soon-to-be-allocated "accept" at the end of its block -- because it can
* be used in the reply.
*/
if (accept) {
free_prod_class(accept); /* NULL safe */
accept = NULL;
}
error = lcf_reduceToAcceptable(upName, inet_ntoa(upAddr->sin_addr), offered,
&accept, &isPrimary);
maxHereis = isPrimary ? UINT_MAX : 0;
if (error) {
serror("Couldn't validate HIYA");
svcerr_systemerr(xprt);
svc_destroy(xprt);
exit(error);
}
else {
if (ulogIsDebug())
udebug("intersection: %s", s_prod_class(NULL, 0, accept));
if (accept->psa.psa_len == 0) {
uwarn("Empty intersection of HIYA offer from %s (%s) and ACCEPT "
"entries", upName, s_prod_class(NULL, 0, offered));
svcerr_weakauth(xprt);
svc_destroy(xprt);
exit(0);
}
else {
error = down6_set_prod_class(accept);
if (error) {
if (DOWN6_SYSTEM_ERROR == error) {
serror("Couldn't set product class: %s",
s_prod_class(NULL, 0, accept));
}
else {
uerror("Couldn't set product class: %s",
s_prod_class(NULL, 0, accept));
}
svcerr_systemerr(xprt);
svc_destroy(xprt);
exit(EXIT_FAILURE);
}
/* else */
if (clss_eq(offered, accept)) {
unotice("hiya6: %s", s_prod_class(NULL, 0, offered));
reply.code = OK;
reply.hiya_reply_t_u.max_hereis = maxHereis;
}
else {
if (ulogIsVerbose()) {
char off[512];
char acc[512];
(void) s_prod_class(off, sizeof(off), offered), (void) s_prod_class(
acc, sizeof(acc), accept);
uinfo("hiya6: RECLASS: %s -> %s", off, acc);
}
reply.code = RECLASS;
reply.hiya_reply_t_u.feedPar.prod_class = accept;
reply.hiya_reply_t_u.feedPar.max_hereis = maxHereis;
}
} /* product-intersection != empty set */
} /* successful acl_check_hiya() */
return &reply;
}
/**
* Feeds or notifies a downstream LDM. This function returns either NULL or a
* reply to be sent to the downstream LDM (e.g., a RECLASS message) or
* terminates this process (hopefully after sending some data).
*
* @param xprt [in/out] Pointer to server-side transport handle.
* @param want [in] Pointer to subscription by downstream LDM.
* May contain a "signature" product-specification.
* @param isNotifier [in] Whether or not the upstream LDM is a feeder or a
* notifier.
* @param maxHereis Maximum HEREIS size parameter. Ignored if "isNotifier"
* is true.
* @return The reply for the downstream LDM or NULL if no reply
* should be made.
*/
static fornme_reply_t*
feed_or_notify(
SVCXPRT* const xprt,
const prod_class_t* const want,
const int isNotifier,
const max_hereis_t maxHereis)
{
struct sockaddr_in downAddr = *svc_getcaller(xprt);
ErrorObj* errObj;
int status;
char* downName = NULL;
prod_class_t* origSub = NULL;
prod_class_t* allowSub = NULL;
const signaturet* signature = NULL;
UpFilter* upFilter = NULL;
fornme_reply_t* reply = NULL;
int isPrimary;
static fornme_reply_t theReply;
static prod_class_t* uldbSub = NULL;
/*
* Clean-up from a (possibly) previous invocation
*/
(void)memset(&theReply, 0, sizeof(theReply));
if (uldbSub != NULL) {
free_prod_class(uldbSub);
uldbSub = NULL;
}
downName = strdup(hostbyaddr(&downAddr));
if (NULL == downName) {
LOG_ADD1("Couldn't duplicate downstream host name: \"%s\"",
hostbyaddr(&downAddr));
log_log(LOG_ERR);
svcerr_systemerr(xprt);
goto return_or_exit;
}
set_abbr_ident(downName, isNotifier ? "(noti)" : "(feed)");
/*
* Remove any "signature" specification from the subscription.
*/
if ((errObj = separateProductClass(want, &origSub, &signature)) != NULL) {
err_log_and_free(errObj, ERR_FAILURE);
svcerr_systemerr(xprt);
goto free_down_name;
}
/*
* Get the upstream filter
*/
errObj = lcf_getUpstreamFilter(downName, &downAddr.sin_addr, origSub,
&upFilter);
if (errObj) {
err_log_and_free(ERR_NEW(0, errObj,
"Couldn't get \"upstream\" filter"), ERR_FAILURE);
svcerr_systemerr(xprt);
goto free_orig_sub;
}
if (NULL == upFilter) {
err_log_and_free(ERR_NEW1(0, NULL,
"Upstream filter prevents data-transfer: %s",
s_prod_class(NULL, 0, origSub)), ERR_FAILURE);
svcerr_weakauth(xprt);
goto free_orig_sub;
}
/* TODO: adjust time? */
/*
* Reduce the subscription according to what the downstream host is allowed
* to receive.
*/
status = lcf_reduceToAllowed(downName, &downAddr.sin_addr, origSub,
&allowSub);
if (status == ENOMEM) {
LOG_SERROR0("Couldn't compute wanted/allowed product intersection");
log_log(LOG_ERR);
svcerr_systemerr(xprt);
goto free_up_filter;
}
if (status == EINVAL) {
LOG_ADD1("Invalid pattern in product-class: %s",
s_prod_class(NULL, 0, origSub));
log_log(LOG_WARNING);
theReply.code = BADPATTERN;
reply = &theReply;
goto free_up_filter;
}
assert(status == 0);
(void) logIfReduced(origSub, allowSub, "ALLOW entries");
/*
* Reduce the subscription according to existing subscriptions from the
* same downstream host and, if `isAntiDosEnabled()` returns `true`,
* terminate every previously-existing upstream LDM process that's feeding
* (not notifying) a subset of the subscription to the same IP address.
*
* The following relies on atexit()-registered cleanup for removal of the
* entry from the upstream LDM database.
*/
isPrimary = maxHereis > UINT_MAX / 2;
status = uldb_addProcess(getpid(), 6, &downAddr, allowSub, &uldbSub,
isNotifier, isPrimary);
if (status) {
LOG_ADD0("Couldn't add this process to the upstream LDM database");
log_log(LOG_ERR);
svcerr_systemerr(xprt);
goto free_allow_sub;
}
(void) logIfReduced(allowSub, uldbSub, "existing subscriptions");
/*
* Send a RECLASS reply to the downstream LDM if appropriate.
*/
if (!clss_eq(origSub, uldbSub)) {
theReply.code = RECLASS;
if (0 < uldbSub->psa.psa_len) {
/*
* The downstream LDM is allowed less than it requested and was
* entered into the upstream LDM database.
*/
(void)uldb_remove(getpid()); /* maybe next time */
theReply.fornme_reply_t_u.prod_class = uldbSub;
}
else {
/*
* The downstream LDM isn't allowed anything and wasn't entered
* into the upstream LDM database.
*/
static prod_class noSub = { { 0, 0 }, /* TS_ZERO */
{ 0, 0 }, /* TS_ZERO */ { 0, (prod_spec *) NULL } };
theReply.fornme_reply_t_u.prod_class = &noSub;
}
reply = &theReply;
goto free_allow_sub;
}
/*
* Reply to the downstream LDM that the subscription will be honored.
*/
theReply.code = OK;
theReply.fornme_reply_t_u.id = (unsigned) getpid();
if (!svc_sendreply(xprt, (xdrproc_t)xdr_fornme_reply_t,
(caddr_t)&theReply)) {
LOG_ADD0("svc_sendreply(...) failure");
log_log(LOG_ERR);
svcerr_systemerr(xprt);
goto free_allow_sub;
}
/*
* Wait a second before sending anything to the downstream LDM.
*/
(void) sleep(1);
status = isNotifier
? up6_new_notifier(xprt->xp_sock, downName, &downAddr, uldbSub,
signature, getQueuePath(), interval, upFilter)
: up6_new_feeder(xprt->xp_sock, downName, &downAddr, uldbSub,
signature, getQueuePath(), interval, upFilter,
isPrimary);
svc_destroy(xprt); /* closes the socket */
exit(status);
/*
* Reply and error handling:
*/
free_allow_sub:
free_prod_class(allowSub);
free_up_filter:
upFilter_free(upFilter);
free_orig_sub:
free_prod_class(origSub);
free_down_name:
free(downName);
return_or_exit:
return reply;
}
