zebra: clean up netlink api

 * Rename netlink utility functions like addattr to be less ambiguous
 * Replace rta_attr_* functions with nl_attr_* since they introduced
   inconsistencies in the code
 * Add helper functions for adding rtnexthop struct to the Netlink
   message

Signed-off-by: Jakub Urbańczyk <xthaid@gmail.com>

1 files changed, 28 insertions, 44 deletions

diff --git a/zebra/kernel_netlink.c b/zebra/kernel_netlink.c
index a1f7014ce..75a8e9f17 100644
--- a/zebra/kernel_netlink.c
+++ b/zebra/kernel_netlink.c
@@ -527,8 +527,8 @@ void netlink_parse_rtattr_nested(struct rtattr **tb, int max,
 	netlink_parse_rtattr(tb, max, RTA_DATA(rta), RTA_PAYLOAD(rta));
 }
 
-int addattr_l(struct nlmsghdr *n, unsigned int maxlen, int type,
-	      const void *data, unsigned int alen)
+bool nl_attr_put(struct nlmsghdr *n, unsigned int maxlen, int type,
+		 const void *data, unsigned int alen)
 {
 	int len;
 	struct rtattr *rta;
@@ -536,7 +536,7 @@ int addattr_l(struct nlmsghdr *n, unsigned int maxlen, int type,
 	len = RTA_LENGTH(alen);
 
 	if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len) > maxlen)
-		return -1;
+		return false;
 
 	rta = (struct rtattr *)(((char *)n) + NLMSG_ALIGN(n->nlmsg_len));
 	rta->rta_type = type;
@@ -549,72 +549,56 @@ int addattr_l(struct nlmsghdr *n, unsigned int maxlen, int type,
 
 	n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len);
 
-	return 0;
-}
-
-int rta_addattr_l(struct rtattr *rta, unsigned int maxlen, int type,
-		  const void *data, unsigned int alen)
-{
-	unsigned int len;
-	struct rtattr *subrta;
-
-	len = RTA_LENGTH(alen);
-
-	if (RTA_ALIGN(rta->rta_len) + RTA_ALIGN(len) > maxlen)
-		return -1;
-
-	subrta = (struct rtattr *)(((char *)rta) + RTA_ALIGN(rta->rta_len));
-	subrta->rta_type = type;
-	subrta->rta_len = len;
-
-	if (data)
-		memcpy(RTA_DATA(subrta), data, alen);
-	else
-		assert(alen == 0);
-
-	rta->rta_len = NLMSG_ALIGN(rta->rta_len) + RTA_ALIGN(len);
-
-	return 0;
+	return true;
 }
 
-int addattr16(struct nlmsghdr *n, unsigned int maxlen, int type, uint16_t data)
+bool nl_attr_put16(struct nlmsghdr *n, unsigned int maxlen, int type,
+		   uint16_t data)
 {
-	return addattr_l(n, maxlen, type, &data, sizeof(uint16_t));
+	return nl_attr_put(n, maxlen, type, &data, sizeof(uint16_t));
 }
 
-int addattr32(struct nlmsghdr *n, unsigned int maxlen, int type, int data)
+bool nl_attr_put32(struct nlmsghdr *n, unsigned int maxlen, int type,
+		   uint32_t data)
 {
-	return addattr_l(n, maxlen, type, &data, sizeof(uint32_t));
+	return nl_attr_put(n, maxlen, type, &data, sizeof(uint32_t));
 }
 
-struct rtattr *addattr_nest(struct nlmsghdr *n, int maxlen, int type)
+struct rtattr *nl_attr_nest(struct nlmsghdr *n, unsigned int maxlen, int type)
 {
 	struct rtattr *nest = NLMSG_TAIL(n);
 
-	addattr_l(n, maxlen, type, NULL, 0);
+	if (!nl_attr_put(n, maxlen, type, NULL, 0))
+		return NULL;
+
 	nest->rta_type |= NLA_F_NESTED;
 	return nest;
 }
 
-int addattr_nest_end(struct nlmsghdr *n, struct rtattr *nest)
+int nl_attr_nest_end(struct nlmsghdr *n, struct rtattr *nest)
 {
 	nest->rta_len = (uint8_t *)NLMSG_TAIL(n) - (uint8_t *)nest;
 	return n->nlmsg_len;
 }
 
-struct rtattr *rta_nest(struct rtattr *rta, int maxlen, int type)
+struct rtnexthop *nl_attr_rtnh(struct nlmsghdr *n, unsigned int maxlen)
 {
-	struct rtattr *nest = RTA_TAIL(rta);
+	struct rtnexthop *rtnh = (struct rtnexthop *)NLMSG_TAIL(n);
 
-	rta_addattr_l(rta, maxlen, type, NULL, 0);
-	nest->rta_type |= NLA_F_NESTED;
-	return nest;
+	if (NLMSG_ALIGN(n->nlmsg_len) + RTNH_ALIGN(sizeof(struct rtnexthop))
+	    > maxlen)
+		return NULL;
+
+	memset(rtnh, 0, sizeof(struct rtnexthop));
+	n->nlmsg_len =
+		NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(sizeof(struct rtnexthop));
+
+	return rtnh;
 }
 
-int rta_nest_end(struct rtattr *rta, struct rtattr *nest)
+void nl_attr_rtnh_end(struct nlmsghdr *n, struct rtnexthop *rtnh)
 {
-	nest->rta_len = (uint8_t *)RTA_TAIL(rta) - (uint8_t *)nest;
-	return rta->rta_len;
+	rtnh->rtnh_len = (uint8_t *)NLMSG_TAIL(n) - (uint8_t *)rtnh;
 }
 
 const char *nl_msg_type_to_str(uint16_t msg_type)