snmpd [9/16]: Fix range handling with appl_unregister

[Martijn van Duren]

Right now (un)registering a region with range_subid set to !0 will
fail. Apparently nothing in the wild uses this, but let's fix it.

This is the unregister part.

OK? martijn@

diff --git a/application.c b/application.c
index f8709b8..e780025 100644
--- a/application.c
+++ b/application.c
@@ -115,6 +115,8 @@ struct snmp_target_mib {
 enum appl_error appl_region(struct appl_context *, uint32_t, uint8_t,
     struct ber_oid *, int, int, struct appl_backend *);
 void appl_region_free(struct appl_context *, struct appl_region *);
+enum appl_error appl_region_unregister_match(struct appl_context *, uint8_t,
+    struct ber_oid *, char *, struct appl_backend *, int);
 struct appl_region *appl_region_find(struct appl_context *,
     const struct ber_oid *);
 struct appl_region *appl_region_next(struct appl_context *,
@@ -400,9 +402,10 @@ enum appl_error
 appl_unregister(const char *ctxname, uint8_t priority, struct ber_oid *oid,
     uint8_t range_subid, uint32_t upper_bound, struct appl_backend *backend)
 {
-       struct appl_region *region, search;
        struct appl_context *ctx;
        char oidbuf[1024], subidbuf[11];
+       enum appl_error error;
+       uint32_t lower_bound;
        size_t i;
 
        oidbuf[0] = '\0';
@@ -444,34 +447,45 @@ appl_unregister(const char *ctxname, uint8_t priority, 
struct ber_oid *oid,
                return APPL_ERROR_PARSEERROR;
        }
 
-       if (range_subid > oid->bo_n) {
+       if (range_subid == 0)
+               return appl_region_unregister_match(ctx, priority, oid, oidbuf,
+                   backend, 1);
+
+       range_subid--;
+       if (range_subid >= oid->bo_n) {
                log_warnx("%s: Can't unregiser %s: range_subid too large",
                    backend->ab_name, oidbuf);
                return APPL_ERROR_PARSEERROR;
        }
-       if (range_subid != 0 && oid->bo_id[range_subid] >= upper_bound) {
-               log_warnx("%s: Can't unregister %s: upper bound smaller or "
-                   "equal to range_subid", backend->ab_name, oidbuf);
+       if (oid->bo_id[range_subid] > upper_bound) {
+               log_warnx("%s: Can't unregister %s: upper bound smaller than "
+                   "range_subid", backend->ab_name, oidbuf);
                return APPL_ERROR_PARSEERROR;
        }
 
+       lower_bound = oid->bo_id[range_subid];
+       do {
+               if ((error = appl_region_unregister_match(ctx, priority, oid,
+                   oidbuf, backend, 0)) != APPL_ERROR_NOERROR)
+                       return error;
+       } while (oid->bo_id[range_subid]++ != upper_bound);
+
+       oid->bo_id[range_subid] = lower_bound;
+       do {
+               (void)appl_region_unregister_match(ctx, priority, oid, oidbuf,
+                   backend, 1);
+       } while (oid->bo_id[range_subid]++ != upper_bound);
+
+       return APPL_ERROR_NOERROR;
+}
+
+enum appl_error
+appl_region_unregister_match(struct appl_context *ctx, uint8_t priority,
+    struct ber_oid *oid, char *oidbuf, struct appl_backend *backend, int 
dofree)
+{
+       struct appl_region *region, search;
+
        search.ar_oid = *oid;
-       while (range_subid != 0 &&
-           search.ar_oid.bo_id[range_subid] != upper_bound) {
-               region = RB_FIND(appl_regions, &(ctx->ac_regions), &search);
-               while (region != NULL && region->ar_priority < priority)
-                       region = region->ar_next;
-               if (region == NULL || region->ar_priority != priority) {
-                       log_warnx("%s: Can't unregister %s: region not found",
-                           backend->ab_name, oidbuf);
-                       return APPL_ERROR_UNKNOWNREGISTRATION;
-               }
-               if (region->ar_backend != backend) {
-                       log_warnx("%s: Can't unregister %s: region not owned "
-                           "by backend", backend->ab_name, oidbuf);
-                       return APPL_ERROR_UNKNOWNREGISTRATION;
-               }
-       }
        region = RB_FIND(appl_regions, &(ctx->ac_regions), &search);
        while (region != NULL && region->ar_priority < priority)
                region = region->ar_next;
@@ -485,20 +499,8 @@ appl_unregister(const char *ctxname, uint8_t priority, 
struct ber_oid *oid,
                    "by backend", backend->ab_name, oidbuf);
                return APPL_ERROR_UNKNOWNREGISTRATION;
        }
-
-       search.ar_oid = *oid;
-       while (range_subid != 0 &&
-           search.ar_oid.bo_id[range_subid] != upper_bound) {
-               region = RB_FIND(appl_regions, &(ctx->ac_regions), &search);
-               while (region != NULL && region->ar_priority != priority)
-                       region = region->ar_next;
+       if (dofree)
                appl_region_free(ctx, region);
-       }
-       region = RB_FIND(appl_regions, &(ctx->ac_regions), &search);
-       while (region != NULL && region->ar_priority != priority)
-               region = region->ar_next;
-       appl_region_free(ctx, region);
-
        return APPL_ERROR_NOERROR;
 }