proposal: Use flags to select/match proposals

During proposal selection with ike/child_cfgs a couple of boolean
variables can be set (e.g. private, prefer_self, strip_dh). To simplify
the addition of new parameters, these functions now use a set of flags
instead of indiviual boolean values.

Signed-off-by: Thomas Egerer <[email protected]>

src/libstrongswan/crypto/proposal/proposal.c

@@ -338,8 +338,8 @@ METHOD(proposal_t, strip_dh, void,
  * Select a matching proposal from this and other.
  */
 static bool select_algo(private_proposal_t *this, proposal_t *other,
-						transform_type_t type, bool priv, bool log,
-						uint16_t *alg, uint16_t *ks)
+						transform_type_t type, proposal_selection_flag_t flags,
+						bool log, uint16_t *alg, uint16_t *ks)
 {
 	enumerator_t *e1, *e2;
 	uint16_t alg1, alg2, ks1, ks2;
@@ -390,7 +390,7 @@ static bool select_algo(private_proposal_t *this, proposal_t *other,
 		{
 			if (alg1 == alg2 && ks1 == ks2)
 			{
-				if (!priv && alg1 >= 1024)
+				if (!(flags & PROPOSAL_ALLOW_PRIVATE) && alg1 >= 1024)
 				{
 					if (log)
 					{
@@ -417,7 +417,7 @@ static bool select_algo(private_proposal_t *this, proposal_t *other,
  * is stored there and errors are logged.
  */
 static bool select_algos(private_proposal_t *this, proposal_t *other,
-						 proposal_t *selected, bool private)
+						 proposal_t *selected, proposal_selection_flag_t flags)
 {
 	transform_type_t type;
 	array_t *types;
@@ -434,7 +434,7 @@ static bool select_algos(private_proposal_t *this, proposal_t *other,
 		{
 			continue;
 		}
-		if (select_algo(this, other, type, private, selected != NULL, &alg, &ks))
+		if (select_algo(this, other, type, flags, selected != NULL, &alg, &ks))
 		{
 			if (alg == 0 && type != EXTENDED_SEQUENCE_NUMBERS)
 			{	/* 0 is "valid" for extended sequence numbers, for other
@@ -468,8 +468,8 @@ static bool select_algos(private_proposal_t *this, proposal_t *other,
 }
 
 METHOD(proposal_t, select_proposal, proposal_t*,
-	private_proposal_t *this, proposal_t *other, bool other_remote,
-	bool private)
+	private_proposal_t *this, proposal_t *other,
+	proposal_selection_flag_t flags)
 {
 	proposal_t *selected;
 
@@ -481,7 +481,7 @@ METHOD(proposal_t, select_proposal, proposal_t*,
 		return NULL;
 	}
 
-	if (other_remote)
+	if (flags & PROPOSAL_PREFER_CONFIGURED)
 	{
 		selected = proposal_create(this->protocol, other->get_number(other));
 		selected->set_spi(selected, other->get_spi(other));
@@ -492,7 +492,7 @@ METHOD(proposal_t, select_proposal, proposal_t*,
 		selected->set_spi(selected, this->spi);
 	}
 
-	if (!select_algos(this, other, selected, private))
+	if (!select_algos(this, other, selected, flags))
 	{
 		selected->destroy(selected);
 		return NULL;
@@ -502,13 +502,14 @@ METHOD(proposal_t, select_proposal, proposal_t*,
 }
 
 METHOD(proposal_t, matches, bool,
-	private_proposal_t *this, proposal_t *other, bool private)
+	private_proposal_t *this, proposal_t *other,
+	proposal_selection_flag_t flags)
 {
 	if (this->protocol != other->get_protocol(other))
 	{
 		return FALSE;
 	}
-	return select_algos(this, other, NULL, private);
+	return select_algos(this, other, NULL, flags);
 }
 
 METHOD(proposal_t, get_protocol, protocol_id_t,

src/libstrongswan/crypto/proposal/proposal.h

@@ -23,6 +23,7 @@
 #define PROPOSAL_H_
 
 typedef enum protocol_id_t protocol_id_t;
+typedef enum proposal_selection_flag_t proposal_selection_flag_t;
 typedef enum extended_sequence_numbers_t extended_sequence_numbers_t;
 typedef struct proposal_t proposal_t;
 
@@ -51,6 +52,18 @@ enum protocol_id_t {
  */
 extern enum_name_t *protocol_id_names;
 
+/**
+ * Flags for selecting proposals
+ */
+enum proposal_selection_flag_t {
+	/** Accept algorithms from a private range. */
+	PROPOSAL_ALLOW_PRIVATE = (1<<0),
+	/** Whether to prefer configured or supplied proposals. */
+	PROPOSAL_PREFER_CONFIGURED = (1<<1),
+	/** Whether to strip out diffie hellman groups */
+	PROPOSAL_STRIP_DH = (1<<2),
+};
+
 /**
  * Stores a set of algorithms used for an SA.
  *
@@ -132,15 +145,16 @@ struct proposal_t {
 	 * compared. If they have at least one algorithm of each type
 	 * in common, a resulting proposal of this kind is created.
 	 *
+	 * If the flag PROPOSAL_PREFER_CONFIGURED is set, other is expected to be
+	 * the remote proposal from which to copy SPI and proposal number to the
+	 * result, otherwise copy from this proposal.
+	 *
 	 * @param other			proposal to compare against
-	 * @param other_remote	whether other is the remote proposal from which to
-	 *						copy SPI and proposal number to the result,
-	 *						otherwise copy from this proposal
-	 * @param private		accepts algorithms allocated in a private range
+	 * @param flags			flags to consider during proposal selection
 	 * @return				selected proposal, NULL if proposals don't match
 	 */
 	proposal_t *(*select)(proposal_t *this, proposal_t *other,
-						  bool other_remote, bool private);
+						  proposal_selection_flag_t flags);
 
 	/**
 	 * Check if the given proposal matches this proposal.
@@ -148,10 +162,11 @@ struct proposal_t {
 	 * This is similar to select, but no resulting proposal is selected.
 	 *
 	 * @param other			proposal to compare against
-	 * @param private		accepts algorithms allocated in a private range
+	 * @param flags			flags to consider during proposal selection
 	 * @return				TRUE if the proposals match
 	 */
-	bool (*matches)(proposal_t *this, proposal_t *other, bool private);
+	bool (*matches)(proposal_t *this, proposal_t *other,
+					proposal_selection_flag_t flags);
 
 	/**
 	 * Get the protocol ID of the proposal.