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-rw-r--r--utils/statd/monitor.c399
1 files changed, 399 insertions, 0 deletions
diff --git a/utils/statd/monitor.c b/utils/statd/monitor.c
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+/*
+ * Copyright (C) 1995-1999 Jeffrey A. Uphoff
+ * Major rewrite by Olaf Kirch, Dec. 1996.
+ * Modified by H.J. Lu, 1998.
+ * Tighter access control, Olaf Kirch June 1999.
+ *
+ * NSM for Linux.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <fcntl.h>
+#include <limits.h>
+#include <netdb.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <arpa/inet.h>
+#include <dirent.h>
+
+#include "sockaddr.h"
+#include "rpcmisc.h"
+#include "nsm.h"
+#include "statd.h"
+#include "notlist.h"
+#include "ha-callout.h"
+
+notify_list * rtnl = NULL; /* Run-time notify list. */
+
+/*
+ * Reject requests from non-loopback addresses in order
+ * to prevent attack described in CERT CA-99.05.
+ *
+ * Although the kernel contacts the statd service via only IPv4
+ * transports, the statd service can receive other requests, such
+ * as SM_NOTIFY, from remote peers via IPv6.
+ */
+static _Bool
+caller_is_localhost(struct svc_req *rqstp)
+{
+ struct sockaddr *sap = nfs_getrpccaller(rqstp->rq_xprt);
+ char buf[INET6_ADDRSTRLEN];
+
+ if (!nfs_is_v4_loopback(sap))
+ goto out_nonlocal;
+ return true;
+
+out_nonlocal:
+ if (!statd_present_address(sap, buf, sizeof(buf)))
+ buf[0] = '\0';
+ xlog_warn("SM_MON/SM_UNMON call from non-local host %s", buf);
+ return false;
+}
+
+/*
+ * Services SM_MON requests.
+ */
+struct sm_stat_res *
+sm_mon_1_svc(struct mon *argp, struct svc_req *rqstp)
+{
+ static sm_stat_res result;
+ char *mon_name = argp->mon_id.mon_name,
+ *my_name = argp->mon_id.my_id.my_name;
+ struct my_id *id = &argp->mon_id.my_id;
+ char *cp;
+ notify_list *clnt = NULL;
+ struct sockaddr_in my_addr = {
+ .sin_family = AF_INET,
+ .sin_addr.s_addr = htonl(INADDR_LOOPBACK),
+ };
+ char *dnsname = NULL;
+ int existing = 0;
+
+ xlog(D_CALL, "Received SM_MON for %s from %s", mon_name, my_name);
+
+ /* Assume that we'll fail. */
+ result.res_stat = STAT_FAIL;
+ result.state = -1; /* State is undefined for STAT_FAIL. */
+
+ /* 1. Reject any remote callers.
+ * Ignore the my_name specified by the caller, and
+ * use "127.0.0.1" instead.
+ */
+ if (!caller_is_localhost(rqstp))
+ goto failure;
+
+ /* 2. Reject any registrations for non-lockd services.
+ *
+ * This is specific to the linux kernel lockd, which
+ * makes the callback procedure part of the lockd interface.
+ * It is also prone to break when lockd changes its callback
+ * procedure number -- which, in fact, has now happened once.
+ * There must be a better way.... XXX FIXME
+ */
+ if (id->my_prog != 100021 ||
+ (id->my_proc != 16 && id->my_proc != 24))
+ {
+ xlog_warn("Attempt to register callback to %d/%d",
+ id->my_prog, id->my_proc);
+ goto failure;
+ }
+
+ /*
+ * Check hostnames. If I can't look them up, I won't monitor. This
+ * might not be legal, but it adds a little bit of safety and sanity.
+ */
+
+ /* must check for /'s in hostname! See CERT's CA-96.09 for details. */
+ if (strchr(mon_name, '/') || mon_name[0] == '.') {
+ xlog(L_ERROR, "SM_MON request for hostname containing '/' "
+ "or starting '.': %s", mon_name);
+ xlog(L_ERROR, "POSSIBLE SPOOF/ATTACK ATTEMPT!");
+ goto failure;
+ }
+
+ /* my_name must not have white space */
+ for (cp=my_name ; *cp ; cp++)
+ if (*cp == ' ' || *cp == '\t' || *cp == '\r' || *cp == '\n')
+ *cp = '_';
+
+ /*
+ * Hostnames checked OK.
+ * Now choose a hostname to use for matching. We cannot
+ * really trust much in the incoming NOTIFY, so to make
+ * sure that multi-homed hosts work nicely, we get an
+ * FQDN now, and use that for matching.
+ */
+ dnsname = statd_canonical_name(mon_name);
+ if (dnsname == NULL) {
+ xlog(L_WARNING, "No canonical hostname found for %s", mon_name);
+ goto failure;
+ }
+
+ /* Now check to see if this is a duplicate, and warn if so.
+ * I will also return STAT_FAIL. (I *think* this is how I should
+ * handle it.)
+ *
+ * Olaf requests that I allow duplicate SM_MON requests for
+ * hosts due to the way he is coding lockd. No problem,
+ * I'll just do a quickie success return and things should
+ * be happy.
+ */
+ clnt = rtnl;
+
+ while ((clnt = nlist_gethost(clnt, mon_name, 0))) {
+ if (statd_matchhostname(NL_MY_NAME(clnt), my_name) &&
+ NL_MY_PROC(clnt) == id->my_proc &&
+ NL_MY_PROG(clnt) == id->my_prog &&
+ NL_MY_VERS(clnt) == id->my_vers) {
+ if (memcmp(NL_PRIV(clnt), argp->priv, SM_PRIV_SIZE)) {
+ xlog(D_GENERAL,
+ "Received SM_MON request with new "
+ "cookie for %s from procedure on %s",
+ mon_name, my_name);
+
+ existing = 1;
+ break;
+ } else {
+ /* Hey! We already know you guys! */
+ xlog(D_GENERAL,
+ "Duplicate SM_MON request for %s "
+ "from procedure on %s",
+ mon_name, my_name);
+
+ /* But we'll let you pass anyway. */
+ free(dnsname);
+ goto success;
+ }
+ }
+ clnt = NL_NEXT(clnt);
+ }
+
+ /*
+ * We're committed...ignoring errors. Let's hope that a malloc()
+ * doesn't fail. (I should probably fix this assumption.)
+ */
+ if (!existing && !(clnt = nlist_new(my_name, mon_name, 0))) {
+ free(dnsname);
+ xlog_warn("out of memory");
+ goto failure;
+ }
+
+ NL_MY_PROG(clnt) = id->my_prog;
+ NL_MY_VERS(clnt) = id->my_vers;
+ NL_MY_PROC(clnt) = id->my_proc;
+ memcpy(NL_PRIV(clnt), argp->priv, SM_PRIV_SIZE);
+ clnt->dns_name = dnsname;
+
+ /*
+ * Now, Create file on stable storage for host, first deleting any
+ * existing records on file.
+ */
+ nsm_delete_monitored_host(dnsname, mon_name, my_name, 0);
+
+ if (!nsm_insert_monitored_host(dnsname,
+ (struct sockaddr *)(char *)&my_addr, argp)) {
+ nlist_free(existing ? &rtnl : NULL, clnt);
+ goto failure;
+ }
+
+ /* PRC: do the HA callout: */
+ ha_callout("add-client", mon_name, my_name, -1);
+ if (!existing)
+ nlist_insert(&rtnl, clnt);
+ xlog(D_GENERAL, "MONITORING %s for %s", mon_name, my_name);
+ success:
+ result.res_stat = STAT_SUCC;
+ /* SUN's sm_inter.x says this should be "state number of local site".
+ * X/Open says '"state" will be contain the state of the remote NSM.'
+ * href=http://www.opengroup.org/onlinepubs/9629799/SM_MON.htm
+ * Linux lockd currently (2.6.21 and prior) ignores whatever is
+ * returned, and given the above contraction, it probably always will..
+ * So we just return what we always returned. If possible, we
+ * have already told lockd about our state number via a sysctl.
+ * If lockd wants the remote state, it will need to
+ * use SM_STAT (and prayer).
+ */
+ result.state = MY_STATE;
+ return (&result);
+
+failure:
+ xlog_warn("STAT_FAIL to %s for SM_MON of %s", my_name, mon_name);
+ free(clnt);
+ return (&result);
+}
+
+static unsigned int
+load_one_host(const char *hostname,
+ __attribute__ ((unused)) const struct sockaddr *sap,
+ const struct mon *m,
+ __attribute__ ((unused)) const time_t timestamp)
+{
+ notify_list *clnt;
+
+ clnt = nlist_new(m->mon_id.my_id.my_name,
+ m->mon_id.mon_name, 0);
+ if (clnt == NULL)
+ return 0;
+
+ clnt->dns_name = strdup(hostname);
+ if (clnt->dns_name == NULL) {
+ nlist_free(NULL, clnt);
+ free(clnt);
+ return 0;
+ }
+
+ xlog(D_GENERAL, "Adding record for %s to the monitor list...",
+ hostname);
+
+ NL_MY_PROG(clnt) = m->mon_id.my_id.my_prog;
+ NL_MY_VERS(clnt) = m->mon_id.my_id.my_vers;
+ NL_MY_PROC(clnt) = m->mon_id.my_id.my_proc;
+ memcpy(NL_PRIV(clnt), m->priv, SM_PRIV_SIZE);
+
+ nlist_insert(&rtnl, clnt);
+ return 1;
+}
+
+void load_state(void)
+{
+ unsigned int count;
+
+ count = nsm_load_monitor_list(load_one_host);
+ if (count)
+ xlog(D_GENERAL, "Loaded %u previously monitored hosts", count);
+}
+
+/*
+ * Services SM_UNMON requests.
+ *
+ * There is no statement in the X/Open spec's about returning an error
+ * for requests to unmonitor a host that we're *not* monitoring. I just
+ * return the state of the NSM when I get such foolish requests for lack
+ * of any better ideas. (I also log the "offense.")
+ */
+struct sm_stat *
+sm_unmon_1_svc(struct mon_id *argp, struct svc_req *rqstp)
+{
+ static sm_stat result;
+ notify_list *clnt;
+ char *mon_name = argp->mon_name,
+ *my_name = argp->my_id.my_name;
+ struct my_id *id = &argp->my_id;
+ char *cp;
+
+ xlog(D_CALL, "Received SM_UNMON for %s from %s", mon_name, my_name);
+
+ result.state = MY_STATE;
+
+ if (!caller_is_localhost(rqstp))
+ goto failure;
+
+ /* my_name must not have white space */
+ for (cp=my_name ; *cp ; cp++)
+ if (*cp == ' ' || *cp == '\t' || *cp == '\r' || *cp == '\n')
+ *cp = '_';
+
+
+ /* Check if we're monitoring anyone. */
+ if (rtnl == NULL) {
+ xlog_warn("Received SM_UNMON request from %s for %s while not "
+ "monitoring any hosts", my_name, argp->mon_name);
+ return (&result);
+ }
+ clnt = rtnl;
+
+ /*
+ * OK, we are. Now look for appropriate entry in run-time list.
+ * There should only be *one* match on this, since I block "duplicate"
+ * SM_MON calls. (Actually, duplicate calls are allowed, but only one
+ * entry winds up in the list the way I'm currently handling them.)
+ */
+ while ((clnt = nlist_gethost(clnt, mon_name, 0))) {
+ if (statd_matchhostname(NL_MY_NAME(clnt), my_name) &&
+ NL_MY_PROC(clnt) == id->my_proc &&
+ NL_MY_PROG(clnt) == id->my_prog &&
+ NL_MY_VERS(clnt) == id->my_vers) {
+ /* Match! */
+ xlog(D_GENERAL, "UNMONITORING %s for %s",
+ mon_name, my_name);
+
+ /* PRC: do the HA callout: */
+ ha_callout("del-client", mon_name, my_name, -1);
+
+ nsm_delete_monitored_host(clnt->dns_name,
+ mon_name, my_name, 1);
+ nlist_free(&rtnl, clnt);
+
+ return (&result);
+ } else
+ clnt = NL_NEXT(clnt);
+ }
+
+ failure:
+ xlog_warn("Received erroneous SM_UNMON request from %s for %s",
+ my_name, mon_name);
+ return (&result);
+}
+
+
+struct sm_stat *
+sm_unmon_all_1_svc(struct my_id *argp, struct svc_req *rqstp)
+{
+ short int count = 0;
+ static sm_stat result;
+ notify_list *clnt;
+ char *my_name = argp->my_name;
+
+ xlog(D_CALL, "Received SM_UNMON_ALL for %s", my_name);
+
+ if (!caller_is_localhost(rqstp))
+ goto failure;
+
+ result.state = MY_STATE;
+
+ if (rtnl == NULL) {
+ xlog_warn("Received SM_UNMON_ALL request from %s "
+ "while not monitoring any hosts", my_name);
+ return (&result);
+ }
+ clnt = rtnl;
+
+ while ((clnt = nlist_gethost(clnt, my_name, 1))) {
+ if (NL_MY_PROC(clnt) == argp->my_proc &&
+ NL_MY_PROG(clnt) == argp->my_prog &&
+ NL_MY_VERS(clnt) == argp->my_vers) {
+ /* Watch stack! */
+ char mon_name[SM_MAXSTRLEN + 1];
+ notify_list *temp;
+
+ xlog(D_GENERAL,
+ "UNMONITORING (SM_UNMON_ALL) %s for %s",
+ NL_MON_NAME(clnt), NL_MY_NAME(clnt));
+ strncpy(mon_name, NL_MON_NAME(clnt),
+ sizeof (mon_name) - 1);
+ mon_name[sizeof (mon_name) - 1] = '\0';
+ temp = NL_NEXT(clnt);
+ /* PRC: do the HA callout: */
+ ha_callout("del-client", mon_name, my_name, -1);
+ nsm_delete_monitored_host(clnt->dns_name,
+ mon_name, my_name, 1);
+ nlist_free(&rtnl, clnt);
+ ++count;
+ clnt = temp;
+ } else
+ clnt = NL_NEXT(clnt);
+ }
+
+ if (!count) {
+ xlog(D_GENERAL, "SM_UNMON_ALL request from %s with no "
+ "SM_MON requests from it", my_name);
+ }
+
+ failure:
+ return (&result);
+}
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