Implement all TRP and TID fields for filtering
[trust_router.git] / common / tr_filter.c
index 701ec85..0e827f4 100644 (file)
@@ -35,7 +35,6 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <strings.h>
 #include <talloc.h>
 #include <assert.h>
 
 #include <trp_internal.h>
 #include <tid_internal.h>
 
-const TR_FILTER_TYPE tr_filter_types[] = {
-    TR_FILTER_TYPE_TID_INBOUND,
-    TR_FILTER_TYPE_TRP_INBOUND,
-    TR_FILTER_TYPE_TRP_OUTBOUND
-};
-const size_t tr_num_filter_types=sizeof(tr_filter_types)/sizeof(tr_filter_types[0]);
-static const char *tr_filter_type_strings[] = {
-    "tid_inbound",
-    "trp_inbound",
-    "trp_outbound"
-};
+/* Function types for handling filter fields generally. All target values
+ * are represented as strings in a TR_NAME.
+ */
 
-const char *tr_filter_type_to_string(TR_FILTER_TYPE t) {
-  int ii;
-  for (ii=0; ii<tr_num_filter_types;ii++) {
-    if (t==tr_filter_types[ii])
-      return tr_filter_type_strings[ii];
-  }
-  return NULL;
-}
+/* CMP functions return values like strcmp: 0 on match, <0 on target<val, >0 on target>val */
+typedef int (*TR_FILTER_FIELD_CMP)(TR_FILTER_TARGET *target, TR_NAME *val);
+/* get functions return TR_NAME format of the field value. Caller must free it. */
+typedef TR_NAME *(*TR_FILTER_FIELD_GET)(TR_FILTER_TARGET *target);
 
-TR_FILTER_TYPE tr_filter_type_from_string(const char *s)
+static TR_FILTER_TARGET *tr_filter_target_new(TALLOC_CTX *mem_ctx)
 {
-  int ii;
-  for (ii=0; ii<tr_num_filter_types; ii++) {
-    if (strcasecmp(s,  tr_filter_type_strings[ii])==0)
-      return tr_filter_types[ii];
+  TR_FILTER_TARGET *target=talloc(mem_ctx, TR_FILTER_TARGET);
+  if (target) {
+    target->trp_inforec=NULL;
+    target->trp_upd=NULL;
+    target->tid_req=NULL;
   }
-  return TR_FILTER_TYPE_UNKNOWN;
+  return target;
+}
+void tr_filter_target_free(TR_FILTER_TARGET *target)
+{
+  talloc_free(target);
 }
 
-/* Function types for handling filter fields generally. All target values
- * are represented as strings in a TR_NAME.
+/**
+ * Create a filter target for a TID request. Does not change the context of the request,
+ * so this is only valid until that is freed.
+ *
+ * @param mem_ctx talloc context for the object
+ * @param req TID request object
+ * @return pointer to a TR_FILTER_TARGET structure, or null on allocation failure
  */
-typedef int (*TR_FILTER_FIELD_CMP)(void *target, TR_NAME *val); /* returns 1 on match, 0 on no match */
-typedef TR_NAME *(*TR_FILTER_FIELD_GET)(void *target); /* returns string form of the field value */
-
-/* static handler prototypes */
-static int tr_ff_cmp_tid_rp_realm(void *rp_req_arg, TR_NAME *val);
-static TR_NAME *tr_ff_get_tid_rp_realm(void *rp_req_arg);
-static int tr_ff_cmp_trp_info_type(void *inforec_arg, TR_NAME *val);
-static TR_NAME *tr_ff_get_trp_info_type(void *inforec_arg);
+TR_FILTER_TARGET *tr_filter_target_tid_req(TALLOC_CTX *mem_ctx, TID_REQ *req)
+{
+  TR_FILTER_TARGET *target=tr_filter_target_new(mem_ctx);
+  if (target)
+    target->tid_req=req; /* borrowed, not adding to our context */
+  return target;
+}
 
 /**
- * Filter field handler table
+ * Create a filter target for a TRP inforec. Does not change the context of the inforec or duplicate TR_NAMEs,
+ * so this is only valid until those are freed.
+ *
+ * @param mem_ctx talloc context for the object
+ * @param upd Update containing the TRP inforec
+ * @param inforec TRP inforec
+ * @return pointer to a TR_FILTER_TARGET structure, or null on allocation failure
  */
-struct tr_filter_field_entry {
-    TR_FILTER_TYPE filter_type;
-    const char *name;
-    TR_FILTER_FIELD_CMP cmp;
-    TR_FILTER_FIELD_GET get;
-};
-static struct tr_filter_field_entry tr_filter_field_table[] = {
-    {TR_FILTER_TYPE_TID_INBOUND, "rp_realm", tr_ff_cmp_tid_rp_realm, tr_ff_get_tid_rp_realm},
-    {TR_FILTER_TYPE_TRP_INBOUND, "info_type", tr_ff_cmp_trp_info_type, tr_ff_get_trp_info_type},
-    {TR_FILTER_TYPE_TRP_OUTBOUND, "info_type", tr_ff_cmp_trp_info_type, tr_ff_get_trp_info_type},
-    {TR_FILTER_TYPE_UNKNOWN, NULL } /* This must be the final entry */
-};
-
-static struct tr_filter_field_entry *tr_filter_field_entry(TR_FILTER_TYPE filter_type, TR_NAME *field_name)
+TR_FILTER_TARGET *tr_filter_target_trp_inforec(TALLOC_CTX *mem_ctx, TRP_UPD *upd, TRP_INFOREC *inforec)
 {
-  unsigned int ii;
-
-  for (ii=0; tr_filter_field_table[ii].filter_type!=TR_FILTER_TYPE_UNKNOWN; ii++) {
-    if ((tr_filter_field_table[ii].filter_type==filter_type)
-        && (tr_name_cmp_str(field_name, tr_filter_field_table[ii].name)==0)) {
-      return tr_filter_field_table+ii;
-    }
+  TR_FILTER_TARGET *target=tr_filter_target_new(mem_ctx);
+  if (target) {
+    target->trp_inforec = inforec; /* borrowed, not adding to our context */
+    target->trp_upd=upd;
   }
-  return NULL;
+  return target;
 }
 
-static int tr_ff_cmp_tid_rp_realm(void *rp_req_arg, TR_NAME *val)
+/** Handler functions for TID RP_REALM field */
+static int tr_ff_cmp_tid_rp_realm(TR_FILTER_TARGET *target, TR_NAME *val)
 {
-  TID_REQ *req=talloc_get_type_abort(rp_req_arg, TID_REQ);
-  assert(req);
-  return 0==tr_name_cmp(val, req->rp_realm);
+  return tr_name_cmp(tid_req_get_rp_realm(target->tid_req), val);
 }
 
-static TR_NAME *tr_ff_get_tid_rp_realm(void *rp_req_arg)
+static TR_NAME *tr_ff_get_tid_rp_realm(TR_FILTER_TARGET *target)
 {
-  TID_REQ *req=talloc_get_type_abort(rp_req_arg, TID_REQ);
-  assert(req);
-  return tr_dup_name(req->rp_realm);
+  return tr_dup_name(tid_req_get_rp_realm(target->tid_req));
 }
 
-static int tr_ff_cmp_trp_info_type(void *inforec_arg, TR_NAME *val)
+/** Handler functions for TRP info_type field */
+static int tr_ff_cmp_trp_info_type(TR_FILTER_TARGET *target, TR_NAME *val)
 {
-  TRP_INFOREC *inforec=talloc_get_type_abort(inforec_arg, TRP_INFOREC);
+  TRP_INFOREC *inforec=target->trp_inforec;
   char *valstr=NULL;
   int val_type=0;
 
@@ -146,15 +130,258 @@ static int tr_ff_cmp_trp_info_type(void *inforec_arg, TR_NAME *val)
   val_type = trp_inforec_type_from_string(valstr);
   free(valstr);
 
+  /* we do not define an ordering of info types */
   return (val_type==inforec->type);
 }
 
-static TR_NAME *tr_ff_get_trp_info_type(void *inforec_arg)
+static TR_NAME *tr_ff_get_trp_info_type(TR_FILTER_TARGET *target)
 {
-  TRP_INFOREC *inforec=talloc_get_type_abort(inforec_arg, TRP_INFOREC);
+  TRP_INFOREC *inforec=target->trp_inforec;
   return tr_new_name(trp_inforec_type_to_string(inforec->type));
 }
 
+/** Handlers for TRP realm field */
+static int tr_ff_cmp_trp_realm(TR_FILTER_TARGET *target, TR_NAME *val)
+{
+  return tr_name_cmp(trp_upd_get_realm(target->trp_upd), val);
+}
+
+static TR_NAME *tr_ff_get_trp_realm(TR_FILTER_TARGET *target)
+{
+  return tr_dup_name(trp_upd_get_realm(target->trp_upd));
+}
+
+/** Handlers for TID realm field */
+static int tr_ff_cmp_tid_realm(TR_FILTER_TARGET *target, TR_NAME *val)
+{
+  return tr_name_cmp(tid_req_get_realm(target->tid_req), val);
+}
+
+static TR_NAME *tr_ff_get_tid_realm(TR_FILTER_TARGET *target)
+{
+  return tr_dup_name(tid_req_get_realm(target->tid_req));
+}
+
+/** Handlers for TRP community field */
+static int tr_ff_cmp_trp_comm(TR_FILTER_TARGET *target, TR_NAME *val)
+{
+  return tr_name_cmp(trp_upd_get_comm(target->trp_upd), val);
+}
+
+static TR_NAME *tr_ff_get_trp_comm(TR_FILTER_TARGET *target)
+{
+  return tr_dup_name(trp_upd_get_comm(target->trp_upd));
+}
+
+/** Handlers for TID community field */
+static int tr_ff_cmp_tid_comm(TR_FILTER_TARGET *target, TR_NAME *val)
+{
+  return tr_name_cmp(tid_req_get_comm(target->tid_req), val);
+}
+
+static TR_NAME *tr_ff_get_tid_comm(TR_FILTER_TARGET *target)
+{
+  return tr_dup_name(tid_req_get_comm(target->tid_req));
+}
+
+/** Handlers for TRP community_type field */
+static TR_NAME *tr_ff_get_trp_comm_type(TR_FILTER_TARGET *target)
+{
+  TR_NAME *type=NULL;
+
+  switch(trp_inforec_get_comm_type(target->trp_inforec)) {
+    case TR_COMM_APC:
+      type=tr_new_name("apc");
+      break;
+    case TR_COMM_COI:
+      type=tr_new_name("coi");
+      break;
+    default:
+      type=NULL;
+      break; /* unknown types always fail */
+  }
+
+  return type;
+}
+
+static int tr_ff_cmp_trp_comm_type(TR_FILTER_TARGET *target, TR_NAME *val)
+{
+  TR_NAME *type=tr_ff_get_trp_comm_type(target);
+  int retval=0;
+
+  if (type==NULL)
+    retval=1;
+  else {
+    retval = tr_name_cmp(val, type);
+    tr_free_name(type);
+  }
+  return retval;
+}
+
+/** Handlers for TRP realm_role field */
+static TR_NAME *tr_ff_get_trp_realm_role(TR_FILTER_TARGET *target)
+{
+  TR_NAME *type=NULL;
+
+  switch(trp_inforec_get_role(target->trp_inforec)) {
+    case TR_ROLE_IDP:
+      type=tr_new_name("idp");
+      break;
+    case TR_ROLE_RP:
+      type=tr_new_name("rp");
+      break;
+    default:
+      type=NULL;
+      break; /* unknown types always fail */
+  }
+
+  return type;
+}
+
+static int tr_ff_cmp_trp_realm_role(TR_FILTER_TARGET *target, TR_NAME *val)
+{
+  TR_NAME *type=tr_ff_get_trp_realm_role(target);
+  int retval=0;
+
+  if (type==NULL)
+    retval=1;
+  else {
+    retval = tr_name_cmp(val, type);
+    tr_free_name(type);
+  }
+  return retval;
+}
+
+/** Handlers for TRP apc field */
+static int tr_ff_cmp_trp_apc(TR_FILTER_TARGET *target, TR_NAME *val)
+{
+  /* TODO: Handle multiple APCs, not just the first */
+  return tr_name_cmp(tr_apc_get_id(trp_inforec_get_apcs(target->trp_inforec)), val);
+}
+
+static TR_NAME *tr_ff_get_trp_apc(TR_FILTER_TARGET *target)
+{
+  /* TODO: Handle multiple APCs, not just the first */
+  return tr_dup_name(tr_apc_get_id(trp_inforec_get_apcs(target->trp_inforec)));
+}
+
+/** Handlers for TRP owner_realm field */
+static int tr_ff_cmp_trp_owner_realm(TR_FILTER_TARGET *target, TR_NAME *val)
+{
+  return tr_name_cmp(trp_inforec_get_owner_realm(target->trp_inforec), val);
+}
+
+static TR_NAME *tr_ff_get_trp_owner_realm(TR_FILTER_TARGET *target)
+{
+  return tr_dup_name(trp_inforec_get_owner_realm(target->trp_inforec));
+}
+
+/** Handlers for TRP trust_router field */
+static int tr_ff_cmp_trp_trust_router(TR_FILTER_TARGET *target, TR_NAME *val)
+{
+  return tr_name_cmp(trp_inforec_get_trust_router(target->trp_inforec), val);
+}
+
+static TR_NAME *tr_ff_get_trp_trust_router(TR_FILTER_TARGET *target)
+{
+  return tr_dup_name(trp_inforec_get_trust_router(target->trp_inforec));
+}
+
+/** Handlers for TRP owner_contact field */
+static int tr_ff_cmp_trp_owner_contact(TR_FILTER_TARGET *target, TR_NAME *val)
+{
+  return tr_name_cmp(trp_inforec_get_owner_contact(target->trp_inforec), val);
+}
+
+static TR_NAME *tr_ff_get_trp_owner_contact(TR_FILTER_TARGET *target)
+{
+  return tr_dup_name(trp_inforec_get_owner_contact(target->trp_inforec));
+}
+
+/** Handlers for TID req original_coi field */
+static int tr_ff_cmp_tid_orig_coi(TR_FILTER_TARGET *target, TR_NAME *val)
+{
+  return tr_name_cmp(tid_req_get_orig_coi(target->tid_req), val);
+}
+
+static TR_NAME *tr_ff_get_tid_orig_coi(TR_FILTER_TARGET *target)
+{
+  return tr_dup_name(tid_req_get_orig_coi(target->tid_req));
+}
+
+/**
+ * Filter field handler table
+ */
+struct tr_filter_field_entry {
+  TR_FILTER_TYPE filter_type;
+  const char *name;
+  TR_FILTER_FIELD_CMP cmp;
+  TR_FILTER_FIELD_GET get;
+};
+static struct tr_filter_field_entry tr_filter_field_table[] = {
+    /* realm */
+    {TR_FILTER_TYPE_TID_INBOUND, "realm", tr_ff_cmp_tid_realm, tr_ff_get_tid_realm},
+    {TR_FILTER_TYPE_TRP_INBOUND, "realm", tr_ff_cmp_trp_realm, tr_ff_get_trp_realm},
+    {TR_FILTER_TYPE_TRP_OUTBOUND, "realm", tr_ff_cmp_trp_realm, tr_ff_get_trp_realm},
+
+    /* community */
+    {TR_FILTER_TYPE_TID_INBOUND, "community", tr_ff_cmp_tid_comm, tr_ff_get_tid_comm},
+    {TR_FILTER_TYPE_TRP_INBOUND, "community", tr_ff_cmp_trp_comm, tr_ff_get_trp_comm},
+    {TR_FILTER_TYPE_TRP_OUTBOUND, "community", tr_ff_cmp_trp_comm, tr_ff_get_trp_comm},
+
+    /* community type */
+    {TR_FILTER_TYPE_TRP_INBOUND, "community_type", tr_ff_cmp_trp_comm_type, tr_ff_get_trp_comm_type},
+    {TR_FILTER_TYPE_TRP_OUTBOUND, "community_type", tr_ff_cmp_trp_comm_type, tr_ff_get_trp_comm_type},
+
+    /* realm role */
+    {TR_FILTER_TYPE_TRP_INBOUND, "realm_role", tr_ff_cmp_trp_realm_role, tr_ff_get_trp_realm_role},
+    {TR_FILTER_TYPE_TRP_OUTBOUND, "realm_role", tr_ff_cmp_trp_realm_role, tr_ff_get_trp_realm_role},
+
+    /* apc */
+    {TR_FILTER_TYPE_TRP_INBOUND, "apc", tr_ff_cmp_trp_apc, tr_ff_get_trp_apc},
+    {TR_FILTER_TYPE_TRP_OUTBOUND, "apc", tr_ff_cmp_trp_apc, tr_ff_get_trp_apc},
+
+    /* trust_router */
+    {TR_FILTER_TYPE_TRP_INBOUND, "trust_router", tr_ff_cmp_trp_trust_router, tr_ff_get_trp_trust_router},
+    {TR_FILTER_TYPE_TRP_OUTBOUND, "trust_router", tr_ff_cmp_trp_trust_router, tr_ff_get_trp_trust_router},
+
+    /* owner_realm */
+    {TR_FILTER_TYPE_TRP_INBOUND, "owner_realm", tr_ff_cmp_trp_owner_realm, tr_ff_get_trp_owner_realm},
+    {TR_FILTER_TYPE_TRP_OUTBOUND, "owner_realm", tr_ff_cmp_trp_owner_realm, tr_ff_get_trp_owner_realm},
+
+    /* owner_contact */
+    {TR_FILTER_TYPE_TRP_INBOUND, "owner_contact", tr_ff_cmp_trp_owner_contact, tr_ff_get_trp_owner_contact},
+    {TR_FILTER_TYPE_TRP_OUTBOUND, "owner_contact", tr_ff_cmp_trp_owner_contact, tr_ff_get_trp_owner_contact},
+
+    /* rp_realm */
+    {TR_FILTER_TYPE_TID_INBOUND, "rp_realm", tr_ff_cmp_tid_rp_realm, tr_ff_get_tid_rp_realm},
+
+    /* original coi */
+    {TR_FILTER_TYPE_TID_INBOUND, "original_coi", tr_ff_cmp_tid_orig_coi, tr_ff_get_tid_orig_coi},
+
+    /* info_type */
+    {TR_FILTER_TYPE_TRP_INBOUND, "info_type", tr_ff_cmp_trp_info_type, tr_ff_get_trp_info_type},
+    {TR_FILTER_TYPE_TRP_OUTBOUND, "info_type", tr_ff_cmp_trp_info_type, tr_ff_get_trp_info_type},
+
+    /* Unknown */
+    {TR_FILTER_TYPE_UNKNOWN, NULL } /* This must be the final entry */
+};
+
+/* TODO: support TRP metric field (requires > < comparison instead of wildcard match) */
+
+static struct tr_filter_field_entry *tr_filter_field_entry(TR_FILTER_TYPE filter_type, TR_NAME *field_name)
+{
+  unsigned int ii;
+
+  for (ii=0; tr_filter_field_table[ii].filter_type!=TR_FILTER_TYPE_UNKNOWN; ii++) {
+    if ((tr_filter_field_table[ii].filter_type==filter_type)
+        && (tr_name_cmp_str(field_name, tr_filter_field_table[ii].name)==0)) {
+      return tr_filter_field_table+ii;
+    }
+  }
+  return NULL;
+}
+
 /**
  * Apply a filter to a target record or TID request.
  *
@@ -172,7 +399,7 @@ static TR_NAME *tr_ff_get_trp_info_type(void *inforec_arg)
  * @param out_action Action to be carried out (output)
  * @return TR_FILTER_MATCH or TR_FILTER_NO_MATCH
  */
-int tr_filter_apply(void *target,
+int tr_filter_apply(TR_FILTER_TARGET *target,
                     TR_FILTER *filt,
                     TR_CONSTRAINT_SET **constraints,
                     TR_FILTER_ACTION *out_action)
@@ -190,7 +417,7 @@ int tr_filter_apply(void *target,
   /* Step through filter lines looking for a match. If a line matches, retval
    * will be set to TR_FILTER_MATCH, so stop then. */
   for (ii=0, retval=TR_FILTER_NO_MATCH;
-       (ii<TR_MAX_FILTER_LINES) && (retval==TR_FILTER_NO_MATCH);
+       ii<TR_MAX_FILTER_LINES;
        ii++) {
     /* skip empty lines (these shouldn't really happen) */
     if (filt->lines[ii]==NULL)
@@ -209,6 +436,9 @@ int tr_filter_apply(void *target,
         break; /* give up on this filter line */
       }
     }
+
+    if (retval==TR_FILTER_MATCH)
+      break;
   }
 
   if (retval==TR_FILTER_MATCH) {
@@ -224,47 +454,6 @@ int tr_filter_apply(void *target,
   return retval;
 }
 
-int tr_filter_process_rp_permitted(TR_NAME *rp_realm,
-                                   TR_FILTER *rpp_filter,
-                                   TR_CONSTRAINT_SET *in_constraints,
-                                   TR_CONSTRAINT_SET **out_constraints,
-                                   TR_FILTER_ACTION *out_action)
-{
-  int i = 0, j = 0;
-
-  *out_action = TR_FILTER_ACTION_REJECT;
-  *out_constraints = NULL;
-
-  /* If this isn't a valid rp_permitted filter, return no match. */
-  if ((!rpp_filter) ||
-      (TR_FILTER_TYPE_TID_INBOUND != rpp_filter->type)) {
-    return TR_FILTER_NO_MATCH;
-  }
-
-  /* Check if there is a match for this filter. */
-  for (i = 0; i < TR_MAX_FILTER_LINES; i++) {
-    for (j = 0; j < TR_MAX_FILTER_SPECS; j++) {
-
-      if ((rpp_filter->lines[i]) &&
-          (rpp_filter->lines[i]->specs[j]) &&
-          (tr_fspec_matches(rpp_filter->lines[i]->specs[j], 0, rp_realm))) { /* todo: fix or remove */
-        *out_action = rpp_filter->lines[i]->action;
-        *out_constraints = in_constraints;
-        if (rpp_filter->lines[i]->realm_cons)
-          tr_constraint_add_to_set(out_constraints,
-                                   rpp_filter->lines[i]->realm_cons);
-        if (rpp_filter->lines[i]->domain_cons)
-          tr_constraint_add_to_set(out_constraints,
-                                   rpp_filter->lines[i]->domain_cons);
-
-        return TR_FILTER_MATCH;
-      }
-    }
-  }
-  /* If there is no match, indicate that. */
-  return TR_FILTER_NO_MATCH;
-}
-
 void tr_fspec_free(TR_FSPEC *fspec)
 {
   talloc_free(fspec);
@@ -273,40 +462,54 @@ void tr_fspec_free(TR_FSPEC *fspec)
 static int tr_fspec_destructor(void *obj)
 {
   TR_FSPEC *fspec = talloc_get_type_abort(obj, TR_FSPEC);
+  size_t ii;
 
   if (fspec->field != NULL)
     tr_free_name(fspec->field);
-  if (fspec->match != NULL)
-    tr_free_name(fspec->match);
+  for (ii=0; ii<TR_MAX_FILTER_SPEC_MATCHES; ii++) {
+    if (fspec->match[ii] != NULL)
+      tr_free_name(fspec->match[ii]);
+  }
   return 0;
 }
 
 TR_FSPEC *tr_fspec_new(TALLOC_CTX *mem_ctx)
 {
   TR_FSPEC *fspec = talloc(mem_ctx, TR_FSPEC);
+  size_t ii=0;
 
   if (fspec != NULL) {
     fspec->field = NULL;
-    fspec->match = NULL;
-    talloc_set_destructor((void *) fspec, tr_fspec_destructor);
+    for (ii=0; ii<TR_MAX_FILTER_SPEC_MATCHES; ii++)
+      fspec->match[ii] = NULL;
+
+    talloc_set_destructor((void *)fspec, tr_fspec_destructor);
   }
   return fspec;
 }
 
-void tr_fspec_set_match(TR_FSPEC *fspec, TR_NAME *match)
+void tr_fspec_add_match(TR_FSPEC *fspec, TR_NAME *match)
 {
-  if (fspec->match != NULL)
-    tr_free_name(fspec->match);
-  fspec->match = match;
+  size_t ii;
+  for (ii=0; ii<TR_MAX_FILTER_SPEC_MATCHES; ii++) {
+    if (fspec->match[ii]==NULL) {
+      fspec->match[ii]=match;
+      break;
+    }
+  }
+  /* TODO: handle case that adding the match failed */
 }
 
 /* returns 1 if the spec matches */
-int tr_fspec_matches(TR_FSPEC *fspec, TR_FILTER_TYPE ftype, void *target)
+int tr_fspec_matches(TR_FSPEC *fspec, TR_FILTER_TYPE ftype, TR_FILTER_TARGET *target)
 {
   struct tr_filter_field_entry *field=NULL;
   TR_NAME *name=NULL;
+  int retval=0;
 
-  if ((fspec==NULL) || (fspec->match==NULL))
+  size_t ii=0;
+
+  if (fspec==NULL)
     return 0;
 
   /* Look up how to handle the requested field */
@@ -315,8 +518,14 @@ int tr_fspec_matches(TR_FSPEC *fspec, TR_FILTER_TYPE ftype, void *target)
     return 0;
 
   name=field->get(target);
-  return ((fspec->match != NULL) &&
-          (0 != tr_name_prefix_wildcard_match(name, fspec->match)));
+  for (ii=0; ii<TR_MAX_FILTER_SPEC_MATCHES; ii++) {
+    if (fspec->match[ii]!=NULL) {
+      if (tr_name_prefix_wildcard_match(name, fspec->match[ii]))
+        retval=1;
+    }
+  }
+  tr_free_name(name);
+  return retval;
 }
 
 void tr_fline_free(TR_FLINE *fline)
@@ -366,3 +575,183 @@ TR_FILTER_TYPE tr_filter_get_type(TR_FILTER *filt)
 {
   return filt->type;
 }
+
+/**
+ * Check that a filter is valid, i.e., can be processed.
+ *
+ * @param filt Filter to verify
+ * @return 1 if the filter is valid, 0 otherwise
+ */
+int tr_filter_validate(TR_FILTER *filt)
+{
+  size_t ii=0, jj=0, kk=0;
+
+  if (!filt)
+    return 0;
+
+  /* check that we recognize the type */
+  switch(filt->type) {
+    case TR_FILTER_TYPE_TID_INBOUND:
+    case TR_FILTER_TYPE_TRP_INBOUND:
+    case TR_FILTER_TYPE_TRP_OUTBOUND:
+      break;
+
+    default:
+      return 0; /* if we get here, either TR_FILTER_TYPE_UNKNOWN or an invalid value was found */
+  }
+  for (ii=0; ii<TR_MAX_FILTER_LINES; ii++) {
+    if (filt->lines[ii]==NULL)
+      continue; /* an empty filter line is valid */
+
+    /* check that we recognize the action */
+    switch(filt->lines[ii]->action) {
+      case TR_FILTER_ACTION_ACCEPT:
+      case TR_FILTER_ACTION_REJECT:
+        break;
+
+      default:
+        /* if we get here, either TR_FILTER_ACTION_UNKNOWN or an invalid value was found */
+        return 0;
+    }
+
+    for (jj=0; jj<TR_MAX_FILTER_SPECS; jj++) {
+      if (filt->lines[ii]->specs[jj]==NULL)
+        continue; /* an empty filter spec is valid */
+
+      if (!tr_filter_validate_spec_field(filt->type, filt->lines[ii]->specs[jj]))
+        return 0;
+
+      /* check that at least one match is non-null */
+      for (kk=0; kk<TR_MAX_FILTER_SPEC_MATCHES; kk++) {
+        if (filt->lines[ii]->specs[jj]->match[kk]!=NULL)
+          break;
+      }
+      if (kk==TR_MAX_FILTER_SPEC_MATCHES)
+        return 0;
+    }
+  }
+
+  /* We ran the gauntlet. Success! */
+  return 1;
+}
+
+int tr_filter_validate_spec_field(TR_FILTER_TYPE ftype, TR_FSPEC *fspec)
+{
+  if ((fspec==NULL) || (tr_filter_field_entry(ftype, fspec->field)==NULL))
+    return 0; /* unknown field */
+
+  return 1;
+}
+
+/**
+ * Allocate a new filter set.
+ *
+ * @param mem_ctx Talloc context for the new set
+ * @return Pointer to new set, or null on error
+ */
+TR_FILTER_SET *tr_filter_set_new(TALLOC_CTX *mem_ctx)
+{
+  TR_FILTER_SET *set=talloc(mem_ctx, TR_FILTER_SET);
+  if (set!=NULL) {
+    set->next=NULL;
+    set->this=NULL;
+  }
+  return set;
+}
+
+/**
+ * Free a filter set
+ *
+ * @param fs Filter set to free
+ */
+void tr_filter_set_free(TR_FILTER_SET *fs)
+{
+  talloc_free(fs);
+}
+
+/**
+ * Find the tail of the filter set linked list.
+ *
+ * @param set Set to find tail of
+ * @return Last element in the list
+ */
+static TR_FILTER_SET *tr_filter_set_tail(TR_FILTER_SET *set)
+{
+  while (set->next)
+    set=set->next;
+  return set;
+}
+
+/**
+ * Add new filter to filter set.
+ *
+ * @param set Filter set
+ * @param new New filter to add
+ * @return 0 on success, nonzero on error
+ */
+int tr_filter_set_add(TR_FILTER_SET *set, TR_FILTER *new)
+{
+  TR_FILTER_SET *tail=NULL;
+
+  if (set->this==NULL)
+    tail=set;
+  else {
+    tail=tr_filter_set_tail(set);
+    tail->next=tr_filter_set_new(set);
+    if (tail->next==NULL)
+      return 1;
+    tail=tail->next;
+  }
+  tail->this=new;
+  talloc_steal(tail, new);
+  return 0;
+}
+
+/**
+ * Find a filter of a given type in the filter set. If there are multiple, returns the first one.
+ *
+ * @param set Filter set to search
+ * @param type Type of filter to find
+ * @return Borrowed pointer to the filter, or null if no filter of that type is found
+ */
+TR_FILTER *tr_filter_set_get(TR_FILTER_SET *set, TR_FILTER_TYPE type)
+{
+  TR_FILTER_SET *cur=set;
+  while(cur!=NULL) {
+    if ((cur->this != NULL) && (cur->this->type == type))
+      return cur->this;
+    cur=cur->next;
+  }
+  return NULL;
+}
+
+TR_FILTER_TYPE filter_type[]={TR_FILTER_TYPE_TID_INBOUND,
+                              TR_FILTER_TYPE_TRP_INBOUND,
+                              TR_FILTER_TYPE_TRP_OUTBOUND};
+const char *filter_label[]={"tid_inbound",
+                            "trp_inbound",
+                            "trp_outbound"};
+size_t num_filter_types=sizeof(filter_type)/sizeof(filter_type[0]);
+
+const char *tr_filter_type_to_string(TR_FILTER_TYPE ftype)
+{
+  size_t ii=0;
+
+  for (ii=0; ii<num_filter_types; ii++) {
+    if (ftype==filter_type[ii])
+      return filter_label[ii];
+  }
+  return "unknown";
+}
+
+TR_FILTER_TYPE tr_filter_type_from_string(const char *s)
+{
+  size_t ii=0;
+
+  for(ii=0; ii<num_filter_types; ii++) {
+    if (0==strcmp(s, filter_label[ii]))
+      return filter_type[ii];
+  }
+  return TR_FILTER_TYPE_UNKNOWN;
+}
+