o made in kernel libalias mpsafe

o fixed a comment
o made in kernel libalias a bit less verbose (disabled automatic
  logging everytime a new link is added or deleted)

Approved by: glebius (mentor)

6 files changed, 327 insertions, 94 deletions

diff --git a/sys/netinet/libalias/alias.c b/sys/netinet/libalias/alias.c
index 3e136a7..ed500e1 100644
--- a/sys/netinet/libalias/alias.c
+++ b/sys/netinet/libalias/alias.c
@@ -283,6 +283,8 @@ static int	TcpAliasOut(struct libalias *, struct ip *, int, int create);
 static int
 IcmpAliasIn1(struct libalias *la, struct ip *pip)
 {
+
+	LIBALIAS_LOCK_ASSERT(la);
 /*
     De-alias incoming echo and timestamp replies.
     Alias incoming echo and timestamp requests.
@@ -326,6 +328,8 @@ IcmpAliasIn1(struct libalias *la, struct ip *pip)
 static int
 IcmpAliasIn2(struct libalias *la, struct ip *pip)
 {
+
+	LIBALIAS_LOCK_ASSERT(la);
 /*
     Alias incoming ICMP error messages containing
     IP header and first 64 bits of datagram.
@@ -429,6 +433,7 @@ IcmpAliasIn(struct libalias *la, struct ip *pip)
 	int iresult;
 	struct icmp *ic;
 
+	LIBALIAS_LOCK_ASSERT(la);
 /* Return if proxy-only mode is enabled */
 	if (la->packetAliasMode & PKT_ALIAS_PROXY_ONLY)
 		return (PKT_ALIAS_OK);
@@ -468,6 +473,7 @@ IcmpAliasOut1(struct libalias *la, struct ip *pip, int create)
 	struct alias_link *lnk;
 	struct icmp *ic;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	ic = (struct icmp *)ip_next(pip);
 
 /* Save overwritten data for when echo packet returns */
@@ -515,6 +521,7 @@ IcmpAliasOut2(struct libalias *la, struct ip *pip)
 	struct tcphdr *tc;
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	ic = (struct icmp *)ip_next(pip);
 	ip = &ic->icmp_ip;
 
@@ -608,6 +615,7 @@ IcmpAliasOut(struct libalias *la, struct ip *pip, int create)
 	int iresult;
 	struct icmp *ic;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	(void)create;
 
 /* Return if proxy-only mode is enabled */
@@ -650,6 +658,7 @@ ProtoAliasIn(struct libalias *la, struct ip *pip)
 */
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK_ASSERT(la);
 /* Return if proxy-only mode is enabled */
 	if (la->packetAliasMode & PKT_ALIAS_PROXY_ONLY)
 		return (PKT_ALIAS_OK);
@@ -681,6 +690,7 @@ ProtoAliasOut(struct libalias *la, struct ip *pip, int create)
 */
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	(void)create;
 
 /* Return if proxy-only mode is enabled */
@@ -710,6 +720,7 @@ UdpAliasIn(struct libalias *la, struct ip *pip)
 	struct udphdr *ud;
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK_ASSERT(la);
 /* Return if proxy-only mode is enabled */
 	if (la->packetAliasMode & PKT_ALIAS_PROXY_ONLY)
 		return (PKT_ALIAS_OK);
@@ -775,6 +786,7 @@ UdpAliasOut(struct libalias *la, struct ip *pip, int create)
 	struct alias_link *lnk;
 	int error;
 
+	LIBALIAS_LOCK_ASSERT(la);
 /* Return if proxy-only mode is enabled */
 	if (la->packetAliasMode & PKT_ALIAS_PROXY_ONLY)
 		return (PKT_ALIAS_OK);
@@ -835,6 +847,7 @@ TcpAliasIn(struct libalias *la, struct ip *pip)
 	struct tcphdr *tc;
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	tc = (struct tcphdr *)ip_next(pip);
 
 	lnk = FindUdpTcpIn(la, pip->ip_src, pip->ip_dst,
@@ -959,6 +972,7 @@ TcpAliasOut(struct libalias *la, struct ip *pip, int maxpacketsize, int create)
 	struct tcphdr *tc;
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	tc = (struct tcphdr *)ip_next(pip);
 
 	if (create)
@@ -1085,6 +1099,7 @@ FragmentIn(struct libalias *la, struct ip *pip)
 {
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	lnk = FindFragmentIn2(la, pip->ip_src, pip->ip_dst, pip->ip_id);
 	if (lnk != NULL) {
 		struct in_addr original_address;
@@ -1105,6 +1120,7 @@ FragmentOut(struct libalias *la, struct ip *pip)
 {
 	struct in_addr alias_address;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	alias_address = FindAliasAddress(la, pip->ip_src);
 	DifferentialChecksum(&pip->ip_sum,
 	    &alias_address, &pip->ip_src, 2);
@@ -1138,6 +1154,7 @@ LibAliasSaveFragment(struct libalias *la, char *ptr)
 	struct alias_link *lnk;
 	struct ip *pip;
 
+	LIBALIAS_LOCK(la);
 	pip = (struct ip *)ptr;
 	lnk = AddFragmentPtrLink(la, pip->ip_src, pip->ip_id);
 	iresult = PKT_ALIAS_ERROR;
@@ -1145,6 +1162,7 @@ LibAliasSaveFragment(struct libalias *la, char *ptr)
 		SetFragmentPtr(lnk, ptr);
 		iresult = PKT_ALIAS_OK;
 	}
+	LIBALIAS_UNLOCK(la);
 	return (iresult);
 }
 
@@ -1156,17 +1174,18 @@ LibAliasGetFragment(struct libalias *la, char *ptr)
 	char *fptr;
 	struct ip *pip;
 
+	LIBALIAS_LOCK(la);
 	pip = (struct ip *)ptr;
 	lnk = FindFragmentPtr(la, pip->ip_src, pip->ip_id);
 	if (lnk != NULL) {
 		GetFragmentPtr(lnk, &fptr);
 		SetFragmentPtr(lnk, NULL);
 		SetExpire(lnk, 0);	/* Deletes link */
+	} else		
+		fptr = NULL;
 
-		return (fptr);
-	} else {
-		return (NULL);
-	}
+	LIBALIAS_UNLOCK(la);
+	return (fptr);
 }
 
 
@@ -1181,6 +1200,7 @@ LibAliasFragmentIn(struct libalias *la, char *ptr,	/* Points to correctly
 	struct ip *pip;
 	struct ip *fpip;
 
+	LIBALIAS_LOCK(la);
 	(void)la;
 	pip = (struct ip *)ptr;
 	fpip = (struct ip *)ptr_fragment;
@@ -1188,21 +1208,40 @@ LibAliasFragmentIn(struct libalias *la, char *ptr,	/* Points to correctly
 	DifferentialChecksum(&fpip->ip_sum,
 	    &pip->ip_dst, &fpip->ip_dst, 2);
 	fpip->ip_dst = pip->ip_dst;
+	LIBALIAS_UNLOCK(la);
 }
 
+/* Local prototypes */
+static int
+LibAliasOutLocked(struct libalias *la, char *ptr,
+		  int maxpacketsize, int create);
+static int
+LibAliasInLocked(struct libalias *la, char *ptr,
+		  int maxpacketsize);
 
 int
 LibAliasIn(struct libalias *la, char *ptr, int maxpacketsize)
 {
+	int res;
+
+	LIBALIAS_LOCK(la);
+	res = LibAliasInLocked(la, ptr, maxpacketsize);
+	LIBALIAS_UNLOCK(la);
+	return (res);
+}
+
+static int
+LibAliasInLocked(struct libalias *la, char *ptr, int maxpacketsize)
+{
 	struct in_addr alias_addr;
 	struct ip *pip;
 	int iresult;
 
 	if (la->packetAliasMode & PKT_ALIAS_REVERSE) {
 		la->packetAliasMode &= ~PKT_ALIAS_REVERSE;
-		iresult = LibAliasOut(la, ptr, maxpacketsize);
+		iresult = LibAliasOutLocked(la, ptr, maxpacketsize, 1);
 		la->packetAliasMode |= PKT_ALIAS_REVERSE;
-		return (iresult);
+		goto getout;
 	}
 	HouseKeeping(la);
 	ClearCheckNewLink(la);
@@ -1211,8 +1250,10 @@ LibAliasIn(struct libalias *la, char *ptr, int maxpacketsize)
 
 	/* Defense against mangled packets */
 	if (ntohs(pip->ip_len) > maxpacketsize
-	    || (pip->ip_hl << 2) > maxpacketsize)
-		return (PKT_ALIAS_IGNORED);
+	    || (pip->ip_hl << 2) > maxpacketsize) {
+		iresult = PKT_ALIAS_IGNORED; 
+		goto getout;
+	}
 
 	iresult = PKT_ALIAS_IGNORED;
 	if ((ntohs(pip->ip_off) & IP_OFFMASK) == 0) {
@@ -1266,6 +1307,7 @@ LibAliasIn(struct libalias *la, char *ptr, int maxpacketsize)
 		iresult = FragmentIn(la, pip);
 	}
 
+getout:
 	return (iresult);
 }
 
@@ -1286,19 +1328,32 @@ LibAliasIn(struct libalias *la, char *ptr, int maxpacketsize)
 #define UNREG_ADDR_C_UPPER 0xc0a8ffff
 
 int
-LibAliasOut(struct libalias *la, char *ptr,	/* valid IP packet */
-    int maxpacketsize		/* How much the packet data may grow (FTP
-				 * and IRC inline changes) */
-)
+LibAliasOut(struct libalias *la, char *ptr, int maxpacketsize)
 {
-	return (LibAliasOutTry(la, ptr, maxpacketsize, 1));
+	int res;
+
+	LIBALIAS_LOCK(la);
+	res = LibAliasOutLocked(la, ptr, maxpacketsize, 1);
+	LIBALIAS_UNLOCK(la);
+	return (res);
 }
 
 int
-LibAliasOutTry(struct libalias *la, char *ptr,	/* valid IP packet */
+LibAliasOutTry(struct libalias *la, char *ptr, int maxpacketsize, int create)
+{
+	int res;
+
+	LIBALIAS_LOCK(la);
+	res = LibAliasOutLocked(la, ptr, maxpacketsize, create);
+	LIBALIAS_UNLOCK(la);
+	return (res);
+}
+
+static int
+LibAliasOutLocked(struct libalias *la, char *ptr,	/* valid IP packet */
     int maxpacketsize,		/* How much the packet data may grow (FTP
 				 * and IRC inline changes) */
-    int create			/* Create new entries ? */
+    int create                  /* Create new entries ? */
 )
 {
 	int iresult;
@@ -1307,9 +1362,9 @@ LibAliasOutTry(struct libalias *la, char *ptr,	/* valid IP packet */
 
 	if (la->packetAliasMode & PKT_ALIAS_REVERSE) {
 		la->packetAliasMode &= ~PKT_ALIAS_REVERSE;
-		iresult = LibAliasIn(la, ptr, maxpacketsize);
+		iresult = LibAliasInLocked(la, ptr, maxpacketsize);
 		la->packetAliasMode |= PKT_ALIAS_REVERSE;
-		return (iresult);
+		goto getout;
 	}
 	HouseKeeping(la);
 	ClearCheckNewLink(la);
@@ -1317,8 +1372,10 @@ LibAliasOutTry(struct libalias *la, char *ptr,	/* valid IP packet */
 
 	/* Defense against mangled packets */
 	if (ntohs(pip->ip_len) > maxpacketsize
-	    || (pip->ip_hl << 2) > maxpacketsize)
-		return (PKT_ALIAS_IGNORED);
+	    || (pip->ip_hl << 2) > maxpacketsize) {
+		iresult = PKT_ALIAS_IGNORED;
+		goto getout;
+	}
 
 	addr_save = GetDefaultAliasAddress(la);
 	if (la->packetAliasMode & PKT_ALIAS_UNREGISTERED_ONLY) {
@@ -1380,6 +1437,7 @@ LibAliasOutTry(struct libalias *la, char *ptr,	/* valid IP packet */
 	}
 
 	SetDefaultAliasAddress(la, addr_save);
+getout:
 	return (iresult);
 }
 
@@ -1395,12 +1453,13 @@ LibAliasUnaliasOut(struct libalias *la, char *ptr,	/* valid IP packet */
 	struct alias_link *lnk;
 	int iresult = PKT_ALIAS_IGNORED;
 
+	LIBALIAS_LOCK(la);
 	pip = (struct ip *)ptr;
 
 	/* Defense against mangled packets */
 	if (ntohs(pip->ip_len) > maxpacketsize
 	    || (pip->ip_hl << 2) > maxpacketsize)
-		return (iresult);
+		goto getout;
 
 	ud = (struct udphdr *)ip_next(pip);
 	tc = (struct tcphdr *)ip_next(pip);
@@ -1484,6 +1543,8 @@ LibAliasUnaliasOut(struct libalias *la, char *ptr,	/* valid IP packet */
 			iresult = PKT_ALIAS_OK;
 		}
 	}
+getout:
+	LIBALIAS_UNLOCK(la);
 	return (iresult);
 
 }
@@ -1585,17 +1646,16 @@ LibAliasUnLoadAllModule(void)
 
 #ifdef _KERNEL
 /*
- * m_megapullup() function is a big hack (only used in ng_nat and ipfw+nat).
+ * m_megapullup() - this function is a big hack.
+ * Thankfully, it's only used in ng_nat and ipfw+nat.
+ *
+ * It allocates an mbuf with cluster and copies the whole chain into cluster,
+ * so that it is all contiguous and the whole packet can be accessed via a
+ * plain (char *) pointer.  This is required, because libalias doesn't know
+ * how to handle mbuf chains.
  *
- * It allocates an mbuf with cluster and copies the whole
- * chain into cluster, so that it is all contigous and the
- * whole packet can be accessed via char pointer.
- * This is required, because libalias doesn't have idea
- * about mbufs.
- * 
- * On success, m_megapullup returns an mbuf with cluster
- * containing the input packet, on failure NULL.
- * In both cases, the input packet is consumed.
+ * On success, m_megapullup returns an mbuf with cluster containing the input
+ * packet, on failure NULL.  In both cases, the input packet is consumed.
  */
 struct mbuf *
 m_megapullup(struct mbuf *m, int len) {
diff --git a/sys/netinet/libalias/alias_db.c b/sys/netinet/libalias/alias_db.c
index 1061c74..e32a5bd 100644
--- a/sys/netinet/libalias/alias_db.c
+++ b/sys/netinet/libalias/alias_db.c
@@ -463,7 +463,6 @@ AliasLog(char *str, const char *format, ...)
 	
 	va_start(ap, format);
 	vsnprintf(str, LIBALIAS_BUF_SIZE, format, ap);
-	log(LOG_SECURITY | LOG_INFO, "%s\n", str);
 	va_end(ap);
 }
 #else
@@ -482,6 +481,8 @@ AliasLog(FILE *stream, const char *format, ...)
 static void
 ShowAliasStats(struct libalias *la)
 {
+
+	LIBALIAS_LOCK_ASSERT(la);
 /* Used for debugging */
 	if (la->logDesc) {
 		int tot  = la->icmpLinkCount + la->udpLinkCount + 
@@ -575,6 +576,7 @@ GetNewPort(struct libalias *la, struct alias_link *lnk, int alias_port_param)
 	u_short port_sys;
 	u_short port_net;
 
+	LIBALIAS_LOCK_ASSERT(la);
 /*
    Description of alias_port_param for GetNewPort().  When
    this parameter is zero or positive, it precisely specifies
@@ -675,6 +677,7 @@ GetSocket(struct libalias *la, u_short port_net, int *sockfd, int link_type)
 	int sock;
 	struct sockaddr_in sock_addr;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	if (link_type == LINK_TCP)
 		sock = socket(AF_INET, SOCK_STREAM, 0);
 	else if (link_type == LINK_UDP)
@@ -733,6 +736,7 @@ FindNewPortGroup(struct libalias *la,
 	u_short port_sys;
 	int link_type;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	/*
 	 * Get link_type from protocol
 	 */
@@ -812,6 +816,7 @@ CleanupAliasData(struct libalias *la)
 	struct alias_link *lnk;
 	int i, icount;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	icount = 0;
 	for (i = 0; i < LINK_TABLE_OUT_SIZE; i++) {
 		lnk = LIST_FIRST(&la->linkTableOut[i]);
@@ -835,6 +840,7 @@ IncrementalCleanup(struct libalias *la)
 	int icount;
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	icount = 0;
 	lnk = LIST_FIRST(&la->linkTableOut[la->cleanupIndex++]);
 	while (lnk != NULL) {
@@ -875,6 +881,7 @@ DeleteLink(struct alias_link *lnk)
 {
 	struct libalias *la = lnk->la;
 
+	LIBALIAS_LOCK_ASSERT(la);
 /* Don't do anything if the link is marked permanent */
 	if (la->deleteAllLinks == 0 && lnk->flags & LINK_PERMANENT)
 		return;
@@ -959,6 +966,7 @@ AddLink(struct libalias *la, struct in_addr src_addr,
 	u_int start_point;	/* zero, equal to alias port  */
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	lnk = malloc(sizeof(struct alias_link));
 	if (lnk != NULL) {
 		/* Basic initialization */
@@ -1100,6 +1108,7 @@ ReLink(struct alias_link *old_lnk,
 	struct alias_link *new_lnk;	/* zero, equal to alias port  */
 	struct libalias *la = old_lnk->la;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	new_lnk = AddLink(la, src_addr, dst_addr, alias_addr,
 	    src_port, dst_port, alias_port_param,
 	    link_type);
@@ -1125,6 +1134,7 @@ _FindLinkOut(struct libalias *la, struct in_addr src_addr,
 	u_int i;
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	i = StartPointOut(src_addr, dst_addr, src_port, dst_port, link_type);
 	LIST_FOREACH(lnk, &la->linkTableOut[i], list_out) {
 		if (lnk->src_addr.s_addr == src_addr.s_addr
@@ -1172,6 +1182,7 @@ FindLinkOut(struct libalias *la, struct in_addr src_addr,
 {
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	lnk = _FindLinkOut(la, src_addr, dst_addr, src_port, dst_port,
 	    link_type, replace_partial_links);
 
@@ -1208,6 +1219,7 @@ _FindLinkIn(struct libalias *la, struct in_addr dst_addr,
 	struct alias_link *lnk_unknown_dst_addr;
 	struct alias_link *lnk_unknown_dst_port;
 
+	LIBALIAS_LOCK_ASSERT(la);
 /* Initialize pointers */
 	lnk_fully_specified = NULL;
 	lnk_unknown_all = NULL;
@@ -1311,6 +1323,7 @@ FindLinkIn(struct libalias *la, struct in_addr dst_addr,
 {
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	lnk = _FindLinkIn(la, dst_addr, alias_addr, dst_port, alias_port,
 	    link_type, replace_partial_links);
 
@@ -1358,6 +1371,7 @@ FindIcmpIn(struct libalias *la, struct in_addr dst_addr,
 {
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	lnk = FindLinkIn(la, dst_addr, alias_addr,
 	    NO_DEST_PORT, id_alias,
 	    LINK_ICMP, 0);
@@ -1381,6 +1395,7 @@ FindIcmpOut(struct libalias *la, struct in_addr src_addr,
 {
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	lnk = FindLinkOut(la, src_addr, dst_addr,
 	    id, NO_DEST_PORT,
 	    LINK_ICMP, 0);
@@ -1403,6 +1418,7 @@ FindFragmentIn1(struct libalias *la, struct in_addr dst_addr,
 {
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	lnk = FindLinkIn(la, dst_addr, alias_addr,
 	    NO_DEST_PORT, ip_id,
 	    LINK_FRAGMENT_ID, 0);
@@ -1422,6 +1438,8 @@ FindFragmentIn2(struct libalias *la, struct in_addr dst_addr,	/* Doesn't add a l
     struct in_addr alias_addr,	/* is not found.           */
     u_short ip_id)
 {
+	
+	LIBALIAS_LOCK_ASSERT(la);
 	return FindLinkIn(la, dst_addr, alias_addr,
 	    NO_DEST_PORT, ip_id,
 	    LINK_FRAGMENT_ID, 0);
@@ -1432,6 +1450,8 @@ struct alias_link *
 AddFragmentPtrLink(struct libalias *la, struct in_addr dst_addr,
     u_short ip_id)
 {
+
+	LIBALIAS_LOCK_ASSERT(la);
 	return AddLink(la, la->nullAddress, dst_addr, la->nullAddress,
 	    NO_SRC_PORT, NO_DEST_PORT, ip_id,
 	    LINK_FRAGMENT_PTR);
@@ -1442,6 +1462,8 @@ struct alias_link *
 FindFragmentPtr(struct libalias *la, struct in_addr dst_addr,
     u_short ip_id)
 {
+
+	LIBALIAS_LOCK_ASSERT(la);
 	return FindLinkIn(la, dst_addr, la->nullAddress,
 	    NO_DEST_PORT, ip_id,
 	    LINK_FRAGMENT_PTR, 0);
@@ -1455,6 +1477,7 @@ FindProtoIn(struct libalias *la, struct in_addr dst_addr,
 {
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	lnk = FindLinkIn(la, dst_addr, alias_addr,
 	    NO_DEST_PORT, 0,
 	    proto, 1);
@@ -1478,6 +1501,7 @@ FindProtoOut(struct libalias *la, struct in_addr src_addr,
 {
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	lnk = FindLinkOut(la, src_addr, dst_addr,
 	    NO_SRC_PORT, NO_DEST_PORT,
 	    proto, 1);
@@ -1505,6 +1529,7 @@ FindUdpTcpIn(struct libalias *la, struct in_addr dst_addr,
 	int link_type;
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	switch (proto) {
 	case IPPROTO_UDP:
 		link_type = LINK_UDP;
@@ -1544,6 +1569,7 @@ FindUdpTcpOut(struct libalias *la, struct in_addr src_addr,
 	int link_type;
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	switch (proto) {
 	case IPPROTO_UDP:
 		link_type = LINK_UDP;
@@ -1578,6 +1604,7 @@ AddPptp(struct libalias *la, struct in_addr src_addr,
 {
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	lnk = AddLink(la, src_addr, dst_addr, alias_addr,
 	    src_call_id, 0, GET_ALIAS_PORT,
 	    LINK_PPTP);
@@ -1594,6 +1621,7 @@ FindPptpOutByCallId(struct libalias *la, struct in_addr src_addr,
 	u_int i;
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	i = StartPointOut(src_addr, dst_addr, 0, 0, LINK_PPTP);
 	LIST_FOREACH(lnk, &la->linkTableOut[i], list_out)
 	    if (lnk->link_type == LINK_PPTP &&
@@ -1614,6 +1642,7 @@ FindPptpOutByPeerCallId(struct libalias *la, struct in_addr src_addr,
 	u_int i;
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	i = StartPointOut(src_addr, dst_addr, 0, 0, LINK_PPTP);
 	LIST_FOREACH(lnk, &la->linkTableOut[i], list_out)
 	    if (lnk->link_type == LINK_PPTP &&
@@ -1634,6 +1663,7 @@ FindPptpInByCallId(struct libalias *la, struct in_addr dst_addr,
 	u_int i;
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	i = StartPointIn(alias_addr, 0, LINK_PPTP);
 	LIST_FOREACH(lnk, &la->linkTableIn[i], list_in)
 	    if (lnk->link_type == LINK_PPTP &&
@@ -1653,6 +1683,7 @@ FindPptpInByPeerCallId(struct libalias *la, struct in_addr dst_addr,
 {
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	lnk = FindLinkIn(la, dst_addr, alias_addr,
 	    0 /* any */ , alias_call_id,
 	    LINK_PPTP, 0);
@@ -1672,6 +1703,7 @@ FindRtspOut(struct libalias *la, struct in_addr src_addr,
 	int link_type;
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	switch (proto) {
 	case IPPROTO_UDP:
 		link_type = LINK_UDP;
@@ -1703,6 +1735,7 @@ FindOriginalAddress(struct libalias *la, struct in_addr alias_addr)
 {
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	lnk = FindLinkIn(la, la->nullAddress, alias_addr,
 	    0, 0, LINK_ADDR, 0);
 	if (lnk == NULL) {
@@ -1735,6 +1768,7 @@ FindAliasAddress(struct libalias *la, struct in_addr original_addr)
 {
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	lnk = FindLinkOut(la, original_addr, la->nullAddress,
 	    0, 0, LINK_ADDR, 0);
 	if (lnk == NULL) {
@@ -1891,6 +1925,8 @@ GetAliasAddress(struct alias_link *lnk)
 struct in_addr
 GetDefaultAliasAddress(struct libalias *la)
 {
+	
+	LIBALIAS_LOCK_ASSERT(la);
 	return (la->aliasAddress);
 }
 
@@ -1898,6 +1934,8 @@ GetDefaultAliasAddress(struct libalias *la)
 void
 SetDefaultAliasAddress(struct libalias *la, struct in_addr alias_addr)
 {
+
+	LIBALIAS_LOCK_ASSERT(la);
 	la->aliasAddress = alias_addr;
 }
 
@@ -2112,6 +2150,8 @@ SetExpire(struct alias_link *lnk, int expire)
 void
 ClearCheckNewLink(struct libalias *la)
 {
+	
+	LIBALIAS_LOCK_ASSERT(la);
 	la->newDefaultLink = 0;
 }
 
@@ -2134,6 +2174,7 @@ SetDestCallId(struct alias_link *lnk, u_int16_t cid)
 {
 	struct libalias *la = lnk->la;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	la->deleteAllLinks = 1;
 	lnk = ReLink(lnk, lnk->src_addr, lnk->dst_addr, lnk->alias_addr,
 	    lnk->src_port, cid, lnk->alias_port, lnk->link_type);
@@ -2166,6 +2207,7 @@ HouseKeeping(struct libalias *la)
 	struct timezone tz;
 #endif
 
+	LIBALIAS_LOCK_ASSERT(la);
 	/*
 	 * Save system time (seconds) in global variable timeStamp for use
 	 * by other functions. This is done so as not to unnecessarily
@@ -2213,6 +2255,8 @@ HouseKeeping(struct libalias *la)
 static int
 InitPacketAliasLog(struct libalias *la)
 {
+
+	LIBALIAS_LOCK_ASSERT(la);
 	if (~la->packetAliasMode & PKT_ALIAS_LOG) {
 #ifdef _KERNEL
 		if ((la->logDesc = malloc(LIBALIAS_BUF_SIZE)))
@@ -2233,14 +2277,16 @@ InitPacketAliasLog(struct libalias *la)
 static void
 UninitPacketAliasLog(struct libalias *la)
 {
-		if (la->logDesc) {
+
+	LIBALIAS_LOCK_ASSERT(la);
+	if (la->logDesc) {
 #ifdef _KERNEL
-			free(la->logDesc);
+		free(la->logDesc);
 #else
-			fclose(la->logDesc);
+		fclose(la->logDesc);
 #endif
-			la->logDesc = NULL;
-		}
+		la->logDesc = NULL;
+	}
 	la->packetAliasMode &= ~PKT_ALIAS_LOG;
 }
 
@@ -2273,6 +2319,7 @@ LibAliasRedirectPort(struct libalias *la, struct in_addr src_addr, u_short src_p
 	int link_type;
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK(la);
 	switch (proto) {
 	case IPPROTO_UDP:
 		link_type = LINK_UDP;
@@ -2285,7 +2332,8 @@ LibAliasRedirectPort(struct libalias *la, struct in_addr src_addr, u_short src_p
 		fprintf(stderr, "PacketAliasRedirectPort(): ");
 		fprintf(stderr, "only TCP and UDP protocols allowed\n");
 #endif
-		return (NULL);
+		lnk = NULL;
+		goto getout;
 	}
 
 	lnk = AddLink(la, src_addr, dst_addr, alias_addr,
@@ -2302,6 +2350,8 @@ LibAliasRedirectPort(struct libalias *la, struct in_addr src_addr, u_short src_p
 	}
 #endif
 
+getout:
+	LIBALIAS_UNLOCK(la);
 	return (lnk);
 }
 
@@ -2310,7 +2360,9 @@ int
 LibAliasAddServer(struct libalias *la, struct alias_link *lnk, struct in_addr addr, u_short port)
 {
 	struct server *server;
+	int res;
 
+	LIBALIAS_LOCK(la);
 	(void)la;
 
 	server = malloc(sizeof(struct server));
@@ -2332,9 +2384,12 @@ LibAliasAddServer(struct libalias *la, struct alias_link *lnk, struct in_addr ad
 			server->next = head;
 		}
 		lnk->server = server;
-		return (0);
+		res = 0;
 	} else
-		return (-1);
+		res = -1;
+
+	LIBALIAS_UNLOCK(la);
+	return (res);
 }
 
 /* Redirect packets of a given IP protocol from a specific
@@ -2347,6 +2402,7 @@ LibAliasRedirectProto(struct libalias *la, struct in_addr src_addr,
 {
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK(la);
 	lnk = AddLink(la, src_addr, dst_addr, alias_addr,
 	    NO_SRC_PORT, NO_DEST_PORT, 0,
 	    proto);
@@ -2361,6 +2417,7 @@ LibAliasRedirectProto(struct libalias *la, struct in_addr src_addr,
 	}
 #endif
 
+	LIBALIAS_UNLOCK(la);
 	return (lnk);
 }
 
@@ -2371,6 +2428,7 @@ LibAliasRedirectAddr(struct libalias *la, struct in_addr src_addr,
 {
 	struct alias_link *lnk;
 
+	LIBALIAS_LOCK(la);
 	lnk = AddLink(la, src_addr, la->nullAddress, alias_addr,
 	    0, 0, 0,
 	    LINK_ADDR);
@@ -2385,6 +2443,7 @@ LibAliasRedirectAddr(struct libalias *la, struct in_addr src_addr,
 	}
 #endif
 
+	LIBALIAS_UNLOCK(la);
 	return (lnk);
 }
 
@@ -2393,15 +2452,19 @@ LibAliasRedirectAddr(struct libalias *la, struct in_addr src_addr,
 int
 LibAliasRedirectDynamic(struct libalias *la, struct alias_link *lnk)
 {
+	int res;
 
+	LIBALIAS_LOCK(la);
 	(void)la;
 
 	if (lnk->flags & LINK_PARTIALLY_SPECIFIED)
-		return (-1);
+		res = -1;
 	else {
 		lnk->flags &= ~LINK_PERMANENT;
-		return (0);
+		res = 0;
 	}
+	LIBALIAS_UNLOCK(la);
+	return (res);
 }
 
 
@@ -2411,27 +2474,35 @@ LibAliasRedirectDelete(struct libalias *la, struct alias_link *lnk)
 /* This is a dangerous function to put in the API,
    because an invalid pointer can crash the program. */
 
+	LIBALIAS_LOCK(la);
 	la->deleteAllLinks = 1;
 	DeleteLink(lnk);
 	la->deleteAllLinks = 0;
+	LIBALIAS_UNLOCK(la);
 }
 
 
 void
 LibAliasSetAddress(struct libalias *la, struct in_addr addr)
 {
+
+	LIBALIAS_LOCK(la);
 	if (la->packetAliasMode & PKT_ALIAS_RESET_ON_ADDR_CHANGE
 	    && la->aliasAddress.s_addr != addr.s_addr)
 		CleanupAliasData(la);
 
 	la->aliasAddress = addr;
+	LIBALIAS_UNLOCK(la);
 }
 
 
 void
 LibAliasSetTarget(struct libalias *la, struct in_addr target_addr)
 {
+
+	LIBALIAS_LOCK(la);
 	la->targetAddress = target_addr;
+	LIBALIAS_UNLOCK(la);
 }
 
 static void
@@ -2476,8 +2547,10 @@ LibAliasInit(struct libalias *la)
 			LIST_INIT(&la->linkTableOut[i]);
 		for (i = 0; i < LINK_TABLE_IN_SIZE; i++)
 			LIST_INIT(&la->linkTableIn[i]);
-
+		LIBALIAS_LOCK_INIT(la);
+		LIBALIAS_LOCK(la);
 	} else {
+		LIBALIAS_LOCK(la);
 		la->deleteAllLinks = 1;
 		CleanupAliasData(la);
 		la->deleteAllLinks = 0;
@@ -2508,12 +2581,15 @@ LibAliasInit(struct libalias *la)
 #ifndef _KERNEL
 	LibAliasRefreshModules();
 #endif
+	LIBALIAS_UNLOCK(la);
 	return (la);
 }
 
 void
 LibAliasUninit(struct libalias *la)
 {
+
+	LIBALIAS_LOCK(la);
 	la->deleteAllLinks = 1;
 	CleanupAliasData(la);
 	la->deleteAllLinks = 0;
@@ -2522,6 +2598,8 @@ LibAliasUninit(struct libalias *la)
 	UninitPunchFW(la);
 #endif
 	LIST_REMOVE(la, instancelist);
+	LIBALIAS_UNLOCK(la);
+	LIBALIAS_LOCK_DESTROY(la);
 	free(la);
 }
 
@@ -2534,11 +2612,14 @@ LibAliasSetMode(
 				 * do a probe for flag values) */
 )
 {
+	int res = -1;
+
+	LIBALIAS_LOCK(la);
 /* Enable logging? */
 	if (flags & mask & PKT_ALIAS_LOG) {
 		/* Do the enable */
 		if (InitPacketAliasLog(la) == ENOMEM)
-			return (-1);
+			goto getout;
 	} else
 /* _Disable_ logging? */
 	if (~flags & mask & PKT_ALIAS_LOG) {
@@ -2557,14 +2638,22 @@ LibAliasSetMode(
 
 /* Other flags can be set/cleared without special action */
 	la->packetAliasMode = (flags & mask) | (la->packetAliasMode & ~mask);
-	return (la->packetAliasMode);
+	res = la->packetAliasMode;
+getout:
+	LIBALIAS_UNLOCK(la);
+	return (res);
 }
 
 
 int
 LibAliasCheckNewLink(struct libalias *la)
 {
-	return (la->newDefaultLink);
+	int res;
+
+	LIBALIAS_LOCK(la);
+	res = la->newDefaultLink;
+	LIBALIAS_UNLOCK(la);
+	return (res);
 }
 
 
@@ -2670,6 +2759,7 @@ static void
 InitPunchFW(struct libalias *la)
 {
 
+	LIBALIAS_LOCK_ASSERT(la);
 	la->fireWallField = malloc(la->fireWallNumNums);
 	if (la->fireWallField) {
 		memset(la->fireWallField, 0, la->fireWallNumNums);
@@ -2684,6 +2774,8 @@ InitPunchFW(struct libalias *la)
 static void
 UninitPunchFW(struct libalias *la)
 {
+
+	LIBALIAS_LOCK_ASSERT(la);
 	ClearAllFWHoles(la);
 	if (la->fireWallFD >= 0)
 		close(la->fireWallFD);
@@ -2703,6 +2795,7 @@ PunchFWHole(struct alias_link *lnk)
 	struct ip_fw rule;	/* On-the-fly built rule */
 	int fwhole;		/* Where to punch hole */
 
+	LIBALIAS_LOCK_ASSERT(la);
 	la = lnk->la;
 
 /* Don't do anything unless we are asked to */
@@ -2774,9 +2867,9 @@ PunchFWHole(struct alias_link *lnk)
 static void
 ClearFWHole(struct alias_link *lnk)
 {
-
 	struct libalias *la;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	la = lnk->la;
 	if (lnk->link_type == LINK_TCP) {
 		int fwhole = lnk->data.tcp->fwhole;	/* Where is the firewall
@@ -2801,6 +2894,7 @@ ClearAllFWHoles(struct libalias *la)
 	struct ip_fw rule;	/* On-the-fly built rule */
 	int i;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	if (la->fireWallFD < 0)
 		return;
 
@@ -2819,14 +2913,20 @@ ClearAllFWHoles(struct libalias *la)
 void
 LibAliasSetFWBase(struct libalias *la, unsigned int base, unsigned int num)
 {
+
+	LIBALIAS_LOCK(la);
 #ifndef NO_FW_PUNCH
 	la->fireWallBaseNum = base;
 	la->fireWallNumNums = num;
 #endif
+	LIBALIAS_UNLOCK(la);
 }
 
 void
 LibAliasSetSkinnyPort(struct libalias *la, unsigned int port)
 {
+
+	LIBALIAS_LOCK(la);
 	la->skinnyPort = port;
+	LIBALIAS_UNLOCK(la);
 }
diff --git a/sys/netinet/libalias/alias_local.h b/sys/netinet/libalias/alias_local.h
index 1dc50c8..2abcb69 100644
--- a/sys/netinet/libalias/alias_local.h
+++ b/sys/netinet/libalias/alias_local.h
@@ -51,7 +51,10 @@
 
 #ifdef _KERNEL
 #include <sys/malloc.h>
+#include <sys/param.h>
 #include <sys/lock.h>
+#include <sys/mutex.h>
+
 /* XXX: LibAliasSetTarget() uses this constant. */
 #define	INADDR_NONE	0xffffffff
 #endif
@@ -146,11 +149,31 @@ struct libalias {
 
 	struct in_addr	true_addr;	/* in network byte order. */
 	u_short		true_port;	/* in host byte order. */
-
+#ifdef  _KERNEL
+	/* 
+	 * avoid races in libalias: every public function has to use it.
+	 */
+	struct mtx mutex;
+#endif
 };
 
 /* Macros */
 
+#ifdef _KERNEL
+#define LIBALIAS_LOCK_INIT(l) \
+        mtx_init(&l->mutex, "per-instance libalias mutex", NULL, MTX_DEF)
+#define LIBALIAS_LOCK_ASSERT(l) mtx_assert(&l->mutex, MA_OWNED)
+#define LIBALIAS_LOCK(l) mtx_lock(&l->mutex)
+#define LIBALIAS_UNLOCK(l) mtx_unlock(&l->mutex)
+#define LIBALIAS_LOCK_DESTROY(l)	mtx_destroy(&l->mutex)
+#else
+#define LIBALIAS_LOCK_INIT(l)
+#define LIBALIAS_LOCK_ASSERT(l)
+#define LIBALIAS_LOCK(l)
+#define LIBALIAS_UNLOCK(l)
+#define LIBALIAS_LOCK_DESTROY(l)
+#endif
+
 /*
  * The following macro is used to update an
  * internet checksum.  "delta" is a 32-bit
diff --git a/sys/netinet/libalias/alias_mod.c b/sys/netinet/libalias/alias_mod.c
index 03daa1e..643fe5f 100644
--- a/sys/netinet/libalias/alias_mod.c
+++ b/sys/netinet/libalias/alias_mod.c
@@ -60,9 +60,9 @@ SLIST_HEAD(dll_chain, dll) dll_chain = SLIST_HEAD_INITIALIZER(foo);
 
 #ifdef _KERNEL
 
-#define	LIBALIAS_LOCK_INIT() \
+#define	LIBALIAS_RWLOCK_INIT() \
         rw_init(&handler_rw, "Libalias_modules_rwlock")
-#define	LIBALIAS_LOCK_DESTROY()	rw_destroy(&handler_rw)
+#define	LIBALIAS_RWLOCK_DESTROY()	rw_destroy(&handler_rw)
 #define	LIBALIAS_WLOCK_ASSERT() \
         rw_assert(&handler_rw, RA_WLOCKED)
 
@@ -95,7 +95,7 @@ _handler_chain_init(void)
 {
 
 	if (!rw_initialized(&handler_rw))
-		LIBALIAS_LOCK_INIT();
+		LIBALIAS_RWLOCK_INIT();
 }
 
 static void
@@ -103,12 +103,12 @@ _handler_chain_destroy(void)
 {
 
 	if (rw_initialized(&handler_rw))
-		LIBALIAS_LOCK_DESTROY();
+		LIBALIAS_RWLOCK_DESTROY();
 }
 
 #else
-#define	LIBALIAS_LOCK_INIT() ;
-#define	LIBALIAS_LOCK_DESTROY()	;
+#define	LIBALIAS_RWLOCK_INIT() ;
+#define	LIBALIAS_RWLOCK_DESTROY()	;
 #define	LIBALIAS_WLOCK_ASSERT()	;
 #define	LIBALIAS_RLOCK() ;
 #define	LIBALIAS_RUNLOCK() ;
diff --git a/sys/netinet/libalias/alias_proxy.c b/sys/netinet/libalias/alias_proxy.c
index 699e421..f435771 100644
--- a/sys/netinet/libalias/alias_proxy.c
+++ b/sys/netinet/libalias/alias_proxy.c
@@ -312,6 +312,8 @@ RuleAdd(struct libalias *la, struct proxy_entry *entry)
 	struct proxy_entry *ptr;
 	struct proxy_entry *ptr_last;
 
+	LIBALIAS_LOCK_ASSERT(la);
+
 	if (la->proxyList == NULL) {
 		la->proxyList = entry;
 		entry->last = NULL;
@@ -353,6 +355,7 @@ RuleDelete(struct proxy_entry *entry)
 	struct libalias *la;
 
 	la = entry->la;
+	LIBALIAS_LOCK_ASSERT(la);
 	if (entry->last != NULL)
 		entry->last->next = entry->next;
 	else
@@ -370,6 +373,7 @@ RuleNumberDelete(struct libalias *la, int rule_index)
 	int err;
 	struct proxy_entry *ptr;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	err = -1;
 	ptr = la->proxyList;
 	while (ptr != NULL) {
@@ -566,6 +570,7 @@ ProxyCheck(struct libalias *la, struct ip *pip,
 	struct in_addr dst_addr;
 	struct proxy_entry *ptr;
 
+	LIBALIAS_LOCK_ASSERT(la);
 	src_addr = pip->ip_src;
 	dst_addr = pip->ip_dst;
 	dst_port = ((struct tcphdr *)ip_next(pip))
@@ -606,6 +611,7 @@ ProxyModify(struct libalias *la, struct alias_link *lnk,
     int proxy_type)
 {
 
+	LIBALIAS_LOCK_ASSERT(la);
 	(void)la;
 
 	switch (proxy_type) {
@@ -648,7 +654,7 @@ LibAliasProxyRule(struct libalias *la, const char *cmd)
  * then 0 is used, and group 0 rules are always checked before any
  * others.
  */
-	int i, n, len;
+	int i, n, len, ret;
 	int cmd_len;
 	int token_count;
 	int state;
@@ -668,11 +674,15 @@ LibAliasProxyRule(struct libalias *la, const char *cmd)
 	struct in_addr dst_addr, dst_mask;
 	struct proxy_entry *proxy_entry;
 
+	LIBALIAS_LOCK(la);
+	ret = 0;
 /* Copy command line into a buffer */
 	cmd += strspn(cmd, " \t");
 	cmd_len = strlen(cmd);
-	if (cmd_len > (int)(sizeof(buffer) - 1))
-		return (-1);
+	if (cmd_len > (int)(sizeof(buffer) - 1)) {
+		ret = -1;
+		goto getout;
+	}
 	strcpy(buffer, cmd);
 
 /* Convert to lower case */
@@ -730,8 +740,10 @@ LibAliasProxyRule(struct libalias *la, const char *cmd)
 				state = STATE_READ_SRC;
 			else if (strcmp(token, "dst") == 0)
 				state = STATE_READ_DST;
-			else
-				return (-1);
+			else {
+				ret = -1;
+				goto getout;
+			}
 			break;
 
 		case STATE_READ_TYPE:
@@ -741,8 +753,10 @@ LibAliasProxyRule(struct libalias *la, const char *cmd)
 				proxy_type = PROXY_TYPE_ENCODE_TCPSTREAM;
 			else if (strcmp(token, "no_encode") == 0)
 				proxy_type = PROXY_TYPE_ENCODE_NONE;
-			else
-				return (-1);
+			else {
+				ret = -1;
+				goto getout;
+			}
 			state = STATE_READ_KEYWORD;
 			break;
 
@@ -763,18 +777,24 @@ LibAliasProxyRule(struct libalias *la, const char *cmd)
 
 				if (*p != ':') {
 					err = IpAddr(token, &server_addr);
-					if (err)
-						return (-1);
+					if (err) {
+						ret = -1;
+						goto getout;
+					}
 				} else {
 					*p = ' ';
 
 					n = sscanf(token, "%s %s", s, str_server_port);
-					if (n != 2)
-						return (-1);
+					if (n != 2) {
+						ret = -1;
+						goto getout;
+					}
 
 					err = IpAddr(s, &server_addr);
-					if (err)
-						return (-1);
+					if (err) {
+						ret = -1;
+						goto getout;
+					}
 				}
 			}
 			state = STATE_READ_KEYWORD;
@@ -782,8 +802,10 @@ LibAliasProxyRule(struct libalias *la, const char *cmd)
 
 		case STATE_READ_RULE:
 			n = sscanf(token, "%d", &rule_index);
-			if (n != 1 || rule_index < 0)
-				return (-1);
+			if (n != 1 || rule_index < 0) {
+				ret = -1;
+				goto getout;
+			}
 			state = STATE_READ_KEYWORD;
 			break;
 
@@ -792,16 +814,21 @@ LibAliasProxyRule(struct libalias *la, const char *cmd)
 				int err;
 				int rule_to_delete;
 
-				if (token_count != 2)
-					return (-1);
+				if (token_count != 2) {
+					ret = -1;
+					goto getout;
+				}
 
 				n = sscanf(token, "%d", &rule_to_delete);
-				if (n != 1)
-					return (-1);
+				if (n != 1) {
+					ret = -1;
+					goto getout;
+				}
 				err = RuleNumberDelete(la, rule_to_delete);
 				if (err)
-					return (-1);
-				return (0);
+					ret = -1;
+				ret = 0;
+				goto getout;
 			}
 
 		case STATE_READ_PROTO:
@@ -809,8 +836,10 @@ LibAliasProxyRule(struct libalias *la, const char *cmd)
 				proto = IPPROTO_TCP;
 			else if (strcmp(token, "udp") == 0)
 				proto = IPPROTO_UDP;
-			else
-				return (-1);
+			else {
+				ret = -1;
+				goto getout;
+			}
 			state = STATE_READ_KEYWORD;
 			break;
 
@@ -829,24 +858,32 @@ LibAliasProxyRule(struct libalias *la, const char *cmd)
 				if (*p != '/') {
 					IpMask(32, &mask);
 					err = IpAddr(token, &addr);
-					if (err)
-						return (-1);
+					if (err) {
+						ret = -1;
+						goto getout;
+					}
 				} else {
 					int nbits;
 					char s[sizeof(buffer)];
 
 					*p = ' ';
 					n = sscanf(token, "%s %d", s, &nbits);
-					if (n != 2)
-						return (-1);
+					if (n != 2) {
+						ret = -1;
+						goto getout;
+					}
 
 					err = IpAddr(s, &addr);
-					if (err)
-						return (-1);
+					if (err) {
+						ret = -1;
+						goto getout;
+					}
 
 					err = IpMask(nbits, &mask);
-					if (err)
-						return (-1);
+					if (err) {
+						ret = -1;
+						goto getout;
+					}
 				}
 
 				if (state == STATE_READ_SRC) {
@@ -861,7 +898,8 @@ LibAliasProxyRule(struct libalias *la, const char *cmd)
 			break;
 
 		default:
-			return (-1);
+			ret = -1;
+			goto getout;
 			break;
 		}
 
@@ -887,8 +925,10 @@ LibAliasProxyRule(struct libalias *la, const char *cmd)
 		int err;
 
 		err = IpPort(str_port, proto, &proxy_port);
-		if (err)
-			return (-1);
+		if (err) {
+			ret = -1;
+			goto getout;
+		}
 	} else {
 		proxy_port = 0;
 	}
@@ -897,20 +937,26 @@ LibAliasProxyRule(struct libalias *la, const char *cmd)
 		int err;
 
 		err = IpPort(str_server_port, proto, &server_port);
-		if (err)
-			return (-1);
+		if (err) {
+			ret = -1;
+			goto getout;
+		}
 	} else {
 		server_port = 0;
 	}
 
 /* Check that at least the server address has been defined */
-	if (server_addr.s_addr == 0)
-		return (-1);
+	if (server_addr.s_addr == 0) {
+		ret = -1;
+		goto getout;
+	}
 
 /* Add to linked list */
 	proxy_entry = malloc(sizeof(struct proxy_entry));
-	if (proxy_entry == NULL)
-		return (-1);
+	if (proxy_entry == NULL) {
+		ret = -1;
+		goto getout;
+	}
 
 	proxy_entry->proxy_type = proxy_type;
 	proxy_entry->rule_index = rule_index;
@@ -925,5 +971,7 @@ LibAliasProxyRule(struct libalias *la, const char *cmd)
 
 	RuleAdd(la, proxy_entry);
 
-	return (0);
+getout:
+	LIBALIAS_UNLOCK(la);
+	return (ret);
 }
diff --git a/sys/netinet/libalias/alias_util.c b/sys/netinet/libalias/alias_util.c
index 4cdbaf8..805b51a 100644
--- a/sys/netinet/libalias/alias_util.c
+++ b/sys/netinet/libalias/alias_util.c
@@ -76,6 +76,7 @@ LibAliasInternetChecksum(struct libalias *la __unused, u_short * ptr,
 {
 	int sum, oddbyte;
 
+	LIBALIAS_LOCK(la);
 	sum = 0;
 	while (nbytes > 1) {
 		sum += *ptr++;
@@ -89,6 +90,7 @@ LibAliasInternetChecksum(struct libalias *la __unused, u_short * ptr,
 	}
 	sum = (sum >> 16) + (sum & 0xffff);
 	sum += (sum >> 16);
+	LIBALIAS_UNLOCK(la);
 	return (~sum);
 }