X-Git-Url: http://www.project-moonshot.org/gitweb/?a=blobdiff_plain;f=common%2Ftr_filter.c;h=2b94526b186ddc39fdc485a3c74577d6bffd90dd;hb=fc7fb82d2661d977e7bacb4ffe469f3857a06b63;hp=ecc0a2455fcac1dd64863757c0c267e9e3fee0aa;hpb=09ae7df2ffd6bd4201c52819691b22c2bda63e3a;p=trust_router.git

diff --git a/common/tr_filter.c b/common/tr_filter.c
index ecc0a24..2b94526 100644
--- a/common/tr_filter.c
+++ b/common/tr_filter.c
@@ -36,49 +36,427 @@
 #include <stdlib.h>
 #include <string.h>
 #include <talloc.h>
+#include <assert.h>
 
 #include <tr_filter.h>
+#include <trp_internal.h>
+#include <tid_internal.h>
+#include <tr_debug.h>
 
+/* Function types for handling filter fields generally. All target values
+ * are represented as strings in a TR_NAME.
+ */
+
+/* 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);
+
+static TR_FILTER_TARGET *tr_filter_target_new(TALLOC_CTX *mem_ctx)
+{
+  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 target;
+}
+void tr_filter_target_free(TR_FILTER_TARGET *target)
+{
+  talloc_free(target);
+}
+
+/**
+ * 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
+ */
+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;
+}
+
+/**
+ * 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
+ */
+TR_FILTER_TARGET *tr_filter_target_trp_inforec(TALLOC_CTX *mem_ctx, TRP_UPD *upd, TRP_INFOREC *inforec)
+{
+  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 target;
+}
+
+/** Handler functions for TID RP_REALM field */
+static int tr_ff_cmp_tid_rp_realm(TR_FILTER_TARGET *target, TR_NAME *val)
+{
+  return tr_name_cmp(tid_req_get_rp_realm(target->tid_req), val);
+}
+
+static TR_NAME *tr_ff_get_tid_rp_realm(TR_FILTER_TARGET *target)
+{
+  return tr_dup_name(tid_req_get_rp_realm(target->tid_req));
+}
+
+/** 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=target->trp_inforec;
+  char *valstr=NULL;
+  int val_type=0;
+
+  assert(val);
+  assert(inforec);
+
+  /* nothing matches unknown */
+  if (inforec->type==TRP_INFOREC_TYPE_UNKNOWN)
+    return 0;
+
+  valstr = tr_name_strdup(val); /* get this as an official null-terminated string */
+  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(TR_FILTER_TARGET *target)
+{
+  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);
+}
 
-int tr_filter_process_rp_permitted(TR_NAME *rp_realm,
-                                   TR_FILTER *rpp_filter,
-                                   TR_CONSTRAINT_SET *in_constraints,
-                                   TR_CONSTRAINT_SET **out_constraints,
-                                   int *out_action)
+static TR_NAME *tr_ff_get_tid_comm(TR_FILTER_TARGET *target)
 {
-  int i = 0, j = 0;
+  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 */
+/* TODO: Handle multiple APCs, not just the first */
+static int tr_ff_cmp_trp_apc(TR_FILTER_TARGET *target, TR_NAME *val)
+{
+  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)
+{
+  TR_APC *apc=trp_inforec_get_apcs(target->trp_inforec);
+  if (apc==NULL)
+    return NULL;
+
+  return tr_dup_name(tr_apc_get_id(apc));
+}
+
+/** 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, "comm", tr_ff_cmp_tid_comm, tr_ff_get_tid_comm},
+    {TR_FILTER_TYPE_TRP_INBOUND, "comm", tr_ff_cmp_trp_comm, tr_ff_get_trp_comm},
+    {TR_FILTER_TYPE_TRP_OUTBOUND, "comm", tr_ff_cmp_trp_comm, tr_ff_get_trp_comm},
+
+    /* community type */
+    {TR_FILTER_TYPE_TRP_INBOUND, "comm_type", tr_ff_cmp_trp_comm_type, tr_ff_get_trp_comm_type},
+    {TR_FILTER_TYPE_TRP_OUTBOUND, "comm_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.
+ *
+ * If one of the filter lines matches, out_action is set to the applicable action. If constraints
+ * is not NULL, the constraints from the matching filter line will be added to the constraint set
+ * *constraints, or to a new one if *constraints is NULL. In this case, TR_FILTER_MATCH will be
+ * returned.
+ *
+ * If there is no match, returns TR_FILTER_NO_MATCH, out_action is undefined, and constraints
+ * will not be changed.
+ *
+ * @param target Record or request to which the filter is applied
+ * @param filt Filter to apply
+ * @param constraints Pointer to existing set of constraints (NULL if not tracking constraints)
+ * @param out_action Action to be carried out (output)
+ * @return TR_FILTER_MATCH or TR_FILTER_NO_MATCH
+ */
+int tr_filter_apply(TR_FILTER_TARGET *target,
+                    TR_FILTER *filt,
+                    TR_CONSTRAINT_SET **constraints,
+                    TR_FILTER_ACTION *out_action)
+{
+  TALLOC_CTX *tmp_ctx = talloc_new(NULL);
+  TR_FILTER_ITER *filt_iter = tr_filter_iter_new(tmp_ctx);
+  TR_FLINE *this_fline = NULL;
+  TR_FLINE_ITER *fline_iter = tr_fline_iter_new(tmp_ctx);
+  TR_FSPEC *this_fspec = NULL;
+  int retval=TR_FILTER_NO_MATCH;
+
+  /* Default action is reject */
   *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_RP_PERMITTED != rpp_filter->type)) {
+  /* Validate filter */
+  if ((filt_iter == NULL) || (fline_iter == NULL) || (filt==NULL) || (filt->type==TR_FILTER_TYPE_UNKNOWN)) {
+    talloc_free(tmp_ctx);
     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++) {
+  /* Step through filter lines looking for a match. If a line matches, retval
+   * will be set to TR_FILTER_MATCH, so stop then. */
+  for (this_fline = tr_filter_iter_first(filt_iter, filt);
+       this_fline != NULL;
+       this_fline = tr_filter_iter_next(filt_iter)) {
+    /* Assume we are going to succeed. If any specs fail to match, we'll set
+     * this to TR_FILTER_NO_MATCH. */
+    retval=TR_FILTER_MATCH;
+    for (this_fspec = tr_fline_iter_first(fline_iter, this_fline);
+         this_fspec != NULL;
+         this_fspec = tr_fline_iter_next(fline_iter)) {
+      if (!tr_fspec_matches(this_fspec, filt->type, target)) {
+        retval=TR_FILTER_NO_MATCH; /* set this in case this is the last filter line */
+        break; /* give up on this filter line */
+      }
+    }
 
-      if ((rpp_filter->lines[i]) &&
-          (rpp_filter->lines[i]->specs[j]) &&
-          (tr_fspec_matches(rpp_filter->lines[i]->specs[j], rp_realm))) {
-        *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);
+    if (retval==TR_FILTER_MATCH)
+      break;
 
-        return TR_FILTER_MATCH;
-      }
+  }
+
+  if (retval==TR_FILTER_MATCH) {
+    /* Matched line ii. Grab its action and constraints. */
+    *out_action = this_fline->action;
+    if (constraints!=NULL) {
+      /* if either constraint is missing, these are no-ops */
+      tr_constraint_add_to_set(constraints, this_fline->realm_cons);
+      tr_constraint_add_to_set(constraints, this_fline->domain_cons);
     }
   }
-  /* If there is no match, indicate that. */
-  return TR_FILTER_NO_MATCH;
+
+  return retval;
 }
 
 void tr_fspec_free(TR_FSPEC *fspec)
@@ -86,14 +464,27 @@ void tr_fspec_free(TR_FSPEC *fspec)
   talloc_free(fspec);
 }
 
+/**
+ * Helper for tr_fspec_destructor - calls tr_free_name on its first argument
+ *
+ * @param item void pointer to a TR_NAME
+ * @param cookie ignored
+ */
+static void fspec_destruct_helper(void *item, void *cookie)
+{
+  TR_NAME *name = (TR_NAME *) item;
+  tr_free_name(name);
+}
 static int tr_fspec_destructor(void *obj)
 {
   TR_FSPEC *fspec = talloc_get_type_abort(obj, TR_FSPEC);
 
   if (fspec->field != NULL)
     tr_free_name(fspec->field);
-  if (fspec->match != NULL)
-    tr_free_name(fspec->match);
+
+  if (fspec->match)
+    tr_list_foreach(fspec->match, fspec_destruct_helper, NULL);
+
   return 0;
 }
 
@@ -103,24 +494,69 @@ TR_FSPEC *tr_fspec_new(TALLOC_CTX *mem_ctx)
 
   if (fspec != NULL) {
     fspec->field = NULL;
-    fspec->match = NULL;
-    talloc_set_destructor((void *) fspec, tr_fspec_destructor);
+    fspec->match = tr_list_new(fspec);
+    if (fspec->match == NULL) {
+      talloc_free(fspec);
+      return NULL;
+    }
+    talloc_set_destructor((void *)fspec, tr_fspec_destructor);
   }
   return fspec;
 }
 
-void tr_fspec_set_match(TR_FSPEC *fspec, TR_NAME *match)
+/* Helper function and cookie structure for finding a match. The helper is called
+ * for every item in the match list, even after a match is found. If a match is found,
+ * match should be pointed to the matching item. If this is not NULL, do not change it
+ * because a match has already been found. */
+struct fspec_match_cookie { TR_NAME *name; TR_NAME *match;};
+static void fspec_match_helper(void *item, void *data)
 {
-  if (fspec->match != NULL)
-    tr_free_name(fspec->match);
-  fspec->match = match;
+  TR_NAME *this_name = (TR_NAME *) item;
+  struct fspec_match_cookie *cookie = (struct fspec_match_cookie *) data;
+  if (cookie->match == NULL) {
+    if (tr_name_prefix_wildcard_match(cookie->name, this_name))
+      cookie->match = this_name;
+  }
 }
-
 /* returns 1 if the spec matches */
-int tr_fspec_matches(TR_FSPEC *fspec, TR_NAME *name)
+int tr_fspec_matches(TR_FSPEC *fspec, TR_FILTER_TYPE ftype, TR_FILTER_TARGET *target)
 {
-  return ((fspec->match != NULL) &&
-          (0 != tr_prefix_wildcard_match(name->buf, fspec->match->buf)));
+  struct tr_filter_field_entry *field=NULL;
+  struct fspec_match_cookie cookie = {0};
+
+  if (fspec==NULL)
+    return 0;
+
+  /* Look up how to handle the requested field */
+  field = tr_filter_field_entry(ftype, fspec->field);
+  if (field==NULL) {
+    tr_err("tr_fspec_matches: No entry to handle field %.*s for %*s filter.",
+           fspec->field->len, fspec->field->buf,
+           tr_filter_type_to_string(ftype));
+    return 0;
+  }
+
+  cookie.name = field->get(target);
+  if (cookie.name==NULL)
+    return 0; /* if there's no value, there's no match */
+
+  cookie.match = NULL;
+  tr_list_foreach(fspec->match,
+                  fspec_match_helper,
+                  &cookie);
+  if (cookie.match) {
+    tr_debug("tr_fspec_matches: Field %.*s value \"%.*s\" matches \"%.*s\" for %s filter.",
+             fspec->field->len, fspec->field->buf,
+             cookie.name->len, cookie.name->buf,
+             cookie.match->len, cookie.match->buf,
+             tr_filter_type_to_string(ftype));
+  } else {
+        tr_debug("tr_fspec_matches: Field %.*s value \"%.*s\" does not match for %s filter.",
+                 fspec->field->len, fspec->field->buf,
+                 cookie.name->len, cookie.name->buf,
+                 tr_filter_type_to_string(ftype));
+  }
+  return (cookie.match != NULL);
 }
 
 void tr_fline_free(TR_FLINE *fline)
@@ -131,14 +567,16 @@ void tr_fline_free(TR_FLINE *fline)
 TR_FLINE *tr_fline_new(TALLOC_CTX *mem_ctx)
 {
   TR_FLINE *fl = talloc(mem_ctx, TR_FLINE);
-  int ii = 0;
 
   if (fl != NULL) {
     fl->action = TR_FILTER_ACTION_UNKNOWN;
     fl->realm_cons = NULL;
     fl->domain_cons = NULL;
-    for (ii = 0; ii < TR_MAX_FILTER_SPECS; ii++)
-      fl->specs[ii] = NULL;
+    fl->specs = tr_list_new(fl);
+    if (fl->specs == NULL) {
+      talloc_free(fl);
+      return NULL;
+    }
   }
   return fl;
 }
@@ -146,12 +584,14 @@ TR_FLINE *tr_fline_new(TALLOC_CTX *mem_ctx)
 TR_FILTER *tr_filter_new(TALLOC_CTX *mem_ctx)
 {
   TR_FILTER *f = talloc(mem_ctx, TR_FILTER);
-  int ii = 0;
 
   if (f != NULL) {
     f->type = TR_FILTER_TYPE_UNKNOWN;
-    for (ii = 0; ii < TR_MAX_FILTER_LINES; ii++)
-      f->lines[ii] = NULL;
+    f->lines = tr_list_new(f);
+    if (f->lines == NULL) {
+      talloc_free(f);
+      return NULL;
+    }
   }
   return f;
 }
@@ -170,3 +610,191 @@ 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)
+{
+  TALLOC_CTX *tmp_ctx = talloc_new(NULL);
+  TR_FILTER_ITER *filt_iter = tr_filter_iter_new(tmp_ctx);
+  TR_FLINE *this_fline = NULL;
+  TR_FLINE_ITER *fline_iter = tr_fline_iter_new(tmp_ctx);
+  TR_FSPEC *this_fspec = NULL;
+  
+  if ((!filt) || (!filt_iter) || (!fline_iter)) {
+    talloc_free(tmp_ctx);
+    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:
+      talloc_free(tmp_ctx);
+      return 0; /* if we get here, either TR_FILTER_TYPE_UNKNOWN or an invalid value was found */
+  }
+  
+  for (this_fline = tr_filter_iter_first(filt_iter, filt);
+       this_fline != NULL;
+       this_fline = tr_filter_iter_next(filt_iter)) {
+    /* check that we recognize the action */
+    switch(this_fline->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 */
+        talloc_free(tmp_ctx);
+        return 0;
+    }
+
+    for (this_fspec = tr_fline_iter_first(fline_iter, this_fline);
+         this_fspec != NULL;
+         this_fspec = tr_fline_iter_next(fline_iter)) {
+      if (!tr_filter_validate_spec_field(filt->type, this_fspec)) {
+        talloc_free(tmp_ctx);
+        return 0;
+      }
+
+      /* check that at least one match is defined*/
+      if (tr_list_length(this_fspec->match) == 0) {
+        talloc_free(tmp_ctx);
+        return 0;
+      }
+    }
+  }
+
+  /* We ran the gauntlet. Success! */
+  talloc_free(tmp_ctx);
+  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;
+}
+