[4/7] rtnl: Add a builder for RTM_{NEW|DEL}ADDR messages

Commit Message

Denis Kenzior July 26, 2024, 4:12 p.m. UTC

This builder is based on the new l_netlink_message APIs and is much
simpler to understand.  Use 'ifa' for struct ifaddrmsg since that is the
common convention.
---
 ell/rtnl-private.h | 20 +++++++++++++
 ell/rtnl.c         | 73 +++++++++++++++++++++++++++++++++++-----------
 2 files changed, 76 insertions(+), 17 deletions(-)

Patch

diff --git a/ell/rtnl-private.h b/ell/rtnl-private.h
index ade43b3f053a..fe9cbf35b232 100644
--- a/ell/rtnl-private.h
+++ b/ell/rtnl-private.h
@@ -5,6 +5,23 @@ 
  * SPDX-License-Identifier: LGPL-2.1-or-later
  */
 
+struct l_rtnl_address {
+	uint8_t family;
+	uint8_t prefix_len;
+	uint8_t scope;
+	union {
+		struct in6_addr in6_addr;
+		struct in_addr in_addr;
+	};
+	struct in_addr broadcast;
+	char label[IFNAMSIZ];
+	uint32_t preferred_lifetime;
+	uint32_t valid_lifetime;
+	uint64_t preferred_expiry_time;
+	uint64_t valid_expiry_time;
+	uint32_t flags;
+};
+
 struct l_rtnl_route {
 	uint8_t family;
 	uint8_t scope;
@@ -32,3 +49,6 @@  struct l_rtnl_route {
 struct l_netlink_message *rtnl_message_from_route(uint16_t type, uint16_t flags,
 						int ifindex,
 						const struct l_rtnl_route *rt);
+struct l_netlink_message *rtnl_message_from_address(uint16_t type,
+					uint16_t flags, int ifindex,
+					const struct l_rtnl_address *addr);
diff --git a/ell/rtnl.c b/ell/rtnl.c
index dc3f456e0110..90ff61c09d13 100644
--- a/ell/rtnl.c
+++ b/ell/rtnl.c
@@ -34,23 +34,6 @@ 
 
 static struct l_netlink *rtnl;
 
-struct l_rtnl_address {
-	uint8_t family;
-	uint8_t prefix_len;
-	uint8_t scope;
-	union {
-		struct in6_addr in6_addr;
-		struct in_addr in_addr;
-	};
-	struct in_addr broadcast;
-	char label[IFNAMSIZ];
-	uint32_t preferred_lifetime;
-	uint32_t valid_lifetime;
-	uint64_t preferred_expiry_time;
-	uint64_t valid_expiry_time;
-	uint32_t flags;
-};
-
 static inline int address_to_string(int family, const struct in_addr *v4,
 					const struct in6_addr *v6,
 					char *out_address)
@@ -1644,3 +1627,59 @@  struct l_netlink_message *rtnl_message_from_route(uint16_t type, uint16_t flags,
 
 	return nlm;
 }
+
+struct l_netlink_message *rtnl_message_from_address(uint16_t type,
+					uint16_t flags, int ifindex,
+					const struct l_rtnl_address *addr)
+{
+	struct l_netlink_message *nlm = l_netlink_message_new(type, flags);
+	struct ifaddrmsg ifa;
+	uint64_t now = l_time_now();
+
+	memset(&ifa, 0, sizeof(ifa));
+	ifa.ifa_index = ifindex;
+	ifa.ifa_family = addr->family;
+	ifa.ifa_scope = addr->scope;
+	ifa.ifa_prefixlen = addr->prefix_len;
+	/* Kernel ignores legacy flags in IFA_FLAGS, so set them here */
+	ifa.ifa_flags = addr->flags & 0xff;
+
+	l_netlink_message_add_header(nlm, &ifa, sizeof(ifa));
+
+	if (addr->family == AF_INET) {
+		l_netlink_message_append(nlm, IFA_LOCAL, &addr->in_addr,
+						sizeof(struct in_addr));
+		l_netlink_message_append(nlm, IFA_BROADCAST, &addr->broadcast,
+						sizeof(struct in_addr));
+	} else
+		l_netlink_message_append(nlm, IFA_LOCAL, &addr->in6_addr,
+						sizeof(struct in6_addr));
+
+	/* Address & Prefix length are enough to perform deletions */
+	if (type == RTM_DELADDR)
+		goto done;
+
+	if (addr->flags & 0xffffff00)
+		l_netlink_message_append_u32(nlm, IFA_FLAGS,
+						addr->flags & 0xffffff00);
+
+	if (addr->label[0])
+		l_netlink_message_append(nlm, IFA_LABEL,
+					addr->label, strlen(addr->label) + 1);
+
+	if (addr->preferred_expiry_time > now ||
+			addr->valid_expiry_time > now) {
+		struct ifa_cacheinfo cinfo;
+
+		memset(&cinfo, 0, sizeof(cinfo));
+		cinfo.ifa_prefered = addr->preferred_expiry_time > now ?
+			l_time_to_secs(addr->preferred_expiry_time - now) : 0;
+		cinfo.ifa_valid =  addr->valid_expiry_time > now ?
+			l_time_to_secs(addr->valid_expiry_time - now) : 0;
+
+		l_netlink_message_append(nlm, IFA_CACHEINFO,
+						&cinfo, sizeof(cinfo));
+	}
+done:
+	return nlm;
+}