Eliminate redundant checks for expired leases in ifi->leasedb. Simply

toss expired leases when writing the list to disk. And write the list
to disk before using a lease from it. Just make sure ifi->active
isn't tossed.

diff --git a/sbin/dhclient/dhclient.c b/sbin/dhclient/dhclient.c
index 6ad8cd0..63fa133 100644 (file)
--- a/sbin/dhclient/dhclient.c
+++ b/sbin/dhclient/dhclient.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: dhclient.c,v 1.707 2021/02/28 17:49:01 krw Exp $      */
+/*     $OpenBSD: dhclient.c,v 1.708 2021/03/02 14:32:14 krw Exp $      */
 
 /*
  * Copyright 2004 Henning Brauer <henning@openbsd.org>
@@ -157,7 +157,7 @@ void make_release(struct interface_info *, struct client_lease *);
 void release_lease(struct interface_info *);
 void propose_release(struct interface_info *);
 
-void write_lease_db(struct client_lease_tq *);
+void write_lease_db(struct interface_info *);
 char *lease_as_string(char *, struct client_lease *);
 struct proposal *lease_as_proposal(struct client_lease *);
 struct unwind_info *lease_as_unwind_info(struct client_lease *);
@@ -715,7 +715,7 @@ main(int argc, char *argv[])
 
        if ((leaseFile = fopen(path_lease_db, "w")) == NULL)
                log_warn("%s: fopen(%s)", log_procname, path_lease_db);
-       write_lease_db(&ifi->lease_db);
+       write_lease_db(ifi);
 
        set_user("_dhcp");
 
@@ -966,9 +966,6 @@ void
 dhcpnak(struct interface_info *ifi, const char *src)
 {
        struct client_lease             *ll, *pl;
-       time_t                           cur_time;
-
-       time(&cur_time);
 
        if (ifi->state != S_REBOOTING &&
            ifi->state != S_REQUESTING &&
@@ -980,12 +977,11 @@ dhcpnak(struct interface_info *ifi, const char *src)
 
        log_debug("%s: DHCPNAK from %s", log_procname, src);
 
-       /* Remove expired leases and the NAK'd address from the database. */
+       /* Remove the NAK'd address from the database. */
        TAILQ_FOREACH_SAFE(ll, &ifi->lease_db, next, pl) {
-               if (lease_expiry(ll) < cur_time || (
-                   ifi->ssid_len == ll->ssid_len &&
+               if (ifi->ssid_len == ll->ssid_len &&
                    memcmp(ifi->ssid, ll->ssid, ll->ssid_len) == 0 &&
-                   ll->address.s_addr == ifi->requested_address.s_addr)) {
+                   ll->address.s_addr == ifi->requested_address.s_addr) {
                        if (ll == ifi->active) {
                                tell_unwind(NULL, ifi->flags);
                                free(ifi->unwind_info);
@@ -997,7 +993,7 @@ dhcpnak(struct interface_info *ifi, const char *src)
                        }
                        TAILQ_REMOVE(&ifi->lease_db, ll, next);
                        free_client_lease(ll);
-                       write_lease_db(&ifi->lease_db);
+                       write_lease_db(ifi);
                }
        }
 
@@ -1081,26 +1077,23 @@ bind_lease(struct interface_info *ifi)
                fatal("bind msg");
 
 newlease:
-       /*
-        * Remove previous dynamic lease(s) for this address, and any expired
-        * dynamic leases.
-        */
        seen = 0;
        TAILQ_FOREACH_SAFE(ll, &ifi->lease_db, next, pl) {
-               if (ifi->ssid_len != ll->ssid_len)
-                       continue;
-               if (memcmp(ifi->ssid, ll->ssid, ll->ssid_len) != 0)
+               if (ifi->ssid_len != ll->ssid_len ||
+                   memcmp(ifi->ssid, ll->ssid, ll->ssid_len) != 0)
                        continue;
                if (ifi->active == ll)
                        seen = 1;
-               else if (lease_expiry(ll) < cur_time ||
-                   ll->address.s_addr == ifi->active->address.s_addr) {
+               else if (ll->address.s_addr == ifi->active->address.s_addr) {
                        TAILQ_REMOVE(&ifi->lease_db, ll, next);
                        free_client_lease(ll);
                }
        }
-       if (seen == 0)
+       if (seen == 0) {
+               if (ifi->active->epoch == 0)
+                       time(&ifi->active->epoch);
                TAILQ_INSERT_HEAD(&ifi->lease_db, ifi->active,  next);
+       }
 
        /*
         * Write out updated information before going daemon.
@@ -1109,7 +1102,7 @@ newlease:
         * the bind process is complete and all related information is in
         * place when dhclient(8) goes daemon.
         */
-       write_lease_db(&ifi->lease_db);
+       write_lease_db(ifi);
 
        free_client_lease(lease);
        free(effective_proposal);
@@ -1859,11 +1852,20 @@ free_client_lease(struct client_lease *lease)
 }
 
 void
-write_lease_db(struct client_lease_tq *lease_db)
+write_lease_db(struct interface_info *ifi)
 {
-       struct client_lease     *lp;
+       struct timespec          now;
+       struct client_lease_tq *lease_db = &ifi->lease_db;
+       struct client_lease     *lp, *pl;
        char                    *leasestr;
-       time_t                   cur_time;
+
+       clock_gettime(CLOCK_REALTIME, &now);
+       TAILQ_FOREACH_SAFE(lp, lease_db, next, pl) {
+               if (lp != ifi->active && lease_expiry(lp) < now.tv_sec) {
+                       TAILQ_REMOVE(lease_db, lp, next);
+                       free_client_lease(lp);
+               }
+       }
 
        if (leaseFile == NULL)
                return;
@@ -1878,10 +1880,7 @@ write_lease_db(struct client_lease_tq *lease_db)
         * the leases in ifi->leases in reverse order to recreate
         * the chonological order required.
         */
-       time(&cur_time);
        TAILQ_FOREACH_REVERSE(lp, lease_db, client_lease_tq, next) {
-               if (lease_expiry(lp) < cur_time)
-                       continue;
                leasestr = lease_as_string("lease", lp);
                if (leasestr != NULL)
                        fprintf(leaseFile, "%s", leasestr);
@@ -2544,11 +2543,12 @@ struct client_lease *
 get_recorded_lease(struct interface_info *ifi)
 {
        char                     ifname[IF_NAMESIZE];
-       time_t                   cur_time;
        struct client_lease     *lp;
        int                      i;
 
-       time(&cur_time);
+       /* Update on-disk db, which clears out expired leases. */
+       ifi->active = NULL;
+       write_lease_db(ifi);
 
        /* Run through the list of leases and see if one can be used. */
        i = DHO_DHCP_CLIENT_IDENTIFIER;
@@ -2565,9 +2565,6 @@ get_recorded_lease(struct interface_info *ifi)
                if (addressinuse(ifi->name, lp->address, ifname) != 0 &&
                    strncmp(ifname, ifi->name, IF_NAMESIZE) != 0)
                        continue;
-               if (lease_expiry(lp) <= cur_time)
-                       continue;
-
                break;
        }
 
@@ -2743,7 +2740,7 @@ release_lease(struct interface_info *ifi)
        TAILQ_REMOVE(&ifi->lease_db, ifi->active, next);
        free_client_lease(ifi->active);
        ifi->active = NULL;
-       write_lease_db(&ifi->lease_db);
+       write_lease_db(ifi);
 
        free(ifi->configured);
        ifi->configured = NULL;