odhcpd: rename prefix -> prefix_len

Change a bunch of places where a prefix length is stored as "prefix" to
instead call the length "prefix_len", to make it clearer that it is not
a prefix that is stored.

Signed-off-by: David Härdeman <david@hardeman.nu>
Link: https://github.com/openwrt/odhcpd/pull/320
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

8 files changed, 68 insertions, 64 deletions

diff --git a/src/dhcpv4.c b/src/dhcpv4.c
index 4178b58..78d7c65 100644
--- a/src/dhcpv4.c
+++ b/src/dhcpv4.c
@@ -1373,7 +1373,7 @@ static int dhcpv4_setup_addresses(struct interface *iface)
 		if (addr_is_fr_ip(iface, addr))
 			continue;
 
-		odhcpd_bitlen2netmask(false, iface->addr4[i].prefix, &mask);
+		odhcpd_bitlen2netmask(false, iface->addr4[i].prefix_len, &mask);
 		if ((start & ntohl(~mask.s_addr)) == start &&
 				(end & ntohl(~mask.s_addr)) == end &&
 				end < ntohl(~mask.s_addr)) {	/* Exclude broadcast address */
@@ -1389,7 +1389,7 @@ static int dhcpv4_setup_addresses(struct interface *iface)
 	}
 
 	/* Don't allocate IP range for subnets smaller than /28 */
-	if (iface->addr4[0].prefix > MAX_PREFIX_LEN) {
+	if (iface->addr4[0].prefix_len > MAX_PREFIX_LEN) {
 		warn("Auto allocation of DHCP range fails on %s (prefix length must be < %d).",
 		     iface->name, MAX_PREFIX_LEN + 1);
 		return -1;
@@ -1397,7 +1397,7 @@ static int dhcpv4_setup_addresses(struct interface *iface)
 
 	iface->dhcpv4_local = iface->addr4[0].addr.in;
 	iface->dhcpv4_bcast = iface->addr4[0].broadcast;
-	odhcpd_bitlen2netmask(false, iface->addr4[0].prefix, &iface->dhcpv4_mask);
+	odhcpd_bitlen2netmask(false, iface->addr4[0].prefix_len, &iface->dhcpv4_mask);
 	end = start = iface->dhcpv4_local.s_addr & iface->dhcpv4_mask.s_addr;
 
 	/* Auto allocate ranges */
@@ -1555,7 +1555,7 @@ static void dhcpv4_addrlist_change(struct interface *iface)
 
 	memset(&ip, 0, sizeof(ip));
 	ip.addr.in = iface->dhcpv4_local;
-	ip.prefix = odhcpd_netmask2bitlen(false, &iface->dhcpv4_mask);
+	ip.prefix_len = odhcpd_netmask2bitlen(false, &iface->dhcpv4_mask);
 	ip.broadcast = iface->dhcpv4_bcast;
 
 	dhcpv4_setup_addresses(iface);
diff --git a/src/dhcpv6-ia.c b/src/dhcpv6-ia.c
index dd46a14..b884f9a 100644
--- a/src/dhcpv6-ia.c
+++ b/src/dhcpv6-ia.c
@@ -271,7 +271,7 @@ static void in6_copy_iid(struct in6_addr *dest, uint64_t iid, unsigned n)
 struct in6_addr in6_from_prefix_and_iid(const struct odhcpd_ipaddr *prefix, uint64_t iid)
 {
 	struct in6_addr addr;
-	uint8_t iid_len = min(128 - prefix->prefix, 64);
+	uint8_t iid_len = min(128 - prefix->prefix_len, 64);
 
 	addr = prefix->addr.in6;
 	in6_copy_iid(&addr, iid, iid_len);
@@ -321,9 +321,9 @@ static void set_border_assignment_size(struct interface *iface, struct dhcpv6_le
 			continue;
 
 		if (addr->preferred_lt > (uint32_t)now &&
-		    addr->prefix < 64 &&
-		    addr->prefix > minprefix)
-			minprefix = addr->prefix;
+		    addr->prefix_len < 64 &&
+		    addr->prefix_len > minprefix)
+			minprefix = addr->prefix_len;
 	}
 
 	if (minprefix > 32 && minprefix <= 64)
@@ -664,14 +664,14 @@ static size_t build_ia(uint8_t *buf, size_t buflen, uint16_t status,
 					.len = htons(sizeof(o_ia_p) - 4),
 					.preferred_lt = htonl(prefix_preferred_lt),
 					.valid_lt = htonl(prefix_valid_lt),
-					.prefix = a->length,
+					.prefix_len = a->length,
 					.addr = addrs[i].addr.in6,
 				};
 
 				o_ia_p.addr.s6_addr32[1] |= htonl(a->assigned_subnet_id);
 				o_ia_p.addr.s6_addr32[2] = o_ia_p.addr.s6_addr32[3] = 0;
 
-				if (!valid_prefix_length(a, addrs[i].prefix))
+				if (!valid_prefix_length(a, addrs[i].prefix_len))
 					continue;
 
 				if (buflen < ia_len + sizeof(o_ia_p))
@@ -751,7 +751,7 @@ static size_t build_ia(uint8_t *buf, size_t buflen, uint16_t status,
 					if (!valid_addr(&addrs[i], now))
 						continue;
 
-					if (!valid_prefix_length(a, addrs[i].prefix))
+					if (!valid_prefix_length(a, addrs[i].prefix_len))
 						continue;
 
 					if (ADDR_MATCH_PIO_FILTER(&addrs[i], iface))
@@ -763,7 +763,7 @@ static size_t build_ia(uint8_t *buf, size_t buflen, uint16_t status,
 						addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
 
 						if (!memcmp(&ia_p->addr, &addr, sizeof(addr)) &&
-							    ia_p->prefix == a->length)
+							    ia_p->prefix_len == a->length)
 							found = true;
 					} else {
 						addr = in6_from_prefix_and_iid(&addrs[i], a->assigned_host_id);
@@ -781,7 +781,7 @@ static size_t build_ia(uint8_t *buf, size_t buflen, uint16_t status,
 						.len = htons(sizeof(o_ia_p) - 4),
 						.preferred_lt = 0,
 						.valid_lt = 0,
-						.prefix = ia_p->prefix,
+						.prefix_len = ia_p->prefix_len,
 						.addr = ia_p->addr,
 					};
 
@@ -920,11 +920,11 @@ static bool dhcpv6_ia_on_link(const struct dhcpv6_ia_hdr *ia, struct dhcpv6_leas
 				continue;
 
 			if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
-				if (p->prefix < addrs[i].prefix ||
-				    odhcpd_bmemcmp(&p->addr, &addrs[i].addr.in6, addrs[i].prefix))
+				if (p->prefix_len < addrs[i].prefix_len ||
+				    odhcpd_bmemcmp(&p->addr, &addrs[i].addr.in6, addrs[i].prefix_len))
 					continue;
 
-			} else if (odhcpd_bmemcmp(&n->addr, &addrs[i].addr.in6, addrs[i].prefix))
+			} else if (odhcpd_bmemcmp(&n->addr, &addrs[i].addr.in6, addrs[i].prefix_len))
 				continue;
 
 			onlink = true;
@@ -1007,8 +1007,8 @@ ssize_t dhcpv6_ia_handle_IAs(uint8_t *buf, size_t buflen, struct interface *ifac
 					continue;
 
 				struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&sdata[-4];
-				if (p->prefix) {
-					reqlen = p->prefix;
+				if (p->prefix_len) {
+					reqlen = p->prefix_len;
 					reqhint = ntohl(p->addr.s6_addr32[1]);
 					if (reqlen > 32 && reqlen <= 64)
 						reqhint &= (1U << (64 - reqlen)) - 1;
diff --git a/src/dhcpv6-ia.h b/src/dhcpv6-ia.h
index c75195b..28bc9c0 100644
--- a/src/dhcpv6-ia.h
+++ b/src/dhcpv6-ia.h
@@ -19,7 +19,7 @@
 #define ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs) \
 	((iface)->dhcpv6_assignall || \
 	 (i) == (m) || \
-	 (addrs)[(i)].prefix > 64)
+	 (addrs)[(i)].prefix_len > 64)
 
 size_t get_preferred_addr(const struct odhcpd_ipaddr *addrs, const size_t addrlen);
 
@@ -32,7 +32,7 @@ static inline bool valid_prefix_length(const struct dhcpv6_lease *a, const uint8
 
 static inline bool valid_addr(const struct odhcpd_ipaddr *addr, time_t now)
 {
-	return (addr->prefix <= 96 && addr->valid_lt > (uint32_t)now && addr->preferred_lt > (uint32_t)now);
+	return (addr->prefix_len <= 96 && addr->valid_lt > (uint32_t)now && addr->preferred_lt > (uint32_t)now);
 }
 
 #endif /* _DHCPV6_IA_H_ */
diff --git a/src/dhcpv6.h b/src/dhcpv6.h
index a2b08c6..0a7628c 100644
--- a/src/dhcpv6.h
+++ b/src/dhcpv6.h
@@ -146,7 +146,7 @@ struct dhcpv6_ia_prefix {
 	uint16_t len;
 	uint32_t preferred_lt;
 	uint32_t valid_lt;
-	uint8_t prefix;
+	uint8_t prefix_len;
 	struct in6_addr addr;
 } _o_packed;
 
diff --git a/src/netlink.c b/src/netlink.c
index 48e27d0..5396971 100644
--- a/src/netlink.c
+++ b/src/netlink.c
@@ -204,7 +204,7 @@ static void refresh_iface_addr6(int ifindex)
 			change = len != (ssize_t)iface->addr6_len;
 			for (ssize_t i = 0; !change && i < len; ++i) {
 				if (!IN6_ARE_ADDR_EQUAL(&addr[i].addr.in6, &iface->addr6[i].addr.in6) ||
-				    addr[i].prefix != iface->addr6[i].prefix ||
+				    addr[i].prefix_len != iface->addr6[i].prefix_len ||
 				    (addr[i].preferred_lt > (uint32_t)now) != (iface->addr6[i].preferred_lt > (uint32_t)now) ||
 				    addr[i].valid_lt < iface->addr6[i].valid_lt || addr[i].preferred_lt < iface->addr6[i].preferred_lt)
 					change = true;
@@ -569,7 +569,7 @@ static int cb_addr_valid(struct nl_msg *msg, void *arg)
 		return NL_SKIP;
 
 	memset(&addrs[ctxt->ret], 0, sizeof(addrs[ctxt->ret]));
-	addrs[ctxt->ret].prefix = ifa->ifa_prefixlen;
+	addrs[ctxt->ret].prefix_len = ifa->ifa_prefixlen;
 
 	nla_memcpy(&addrs[ctxt->ret].addr, nla_addr,
 			sizeof(addrs[ctxt->ret].addr));
@@ -624,15 +624,14 @@ static int cb_addr_error(_o_unused struct sockaddr_nl *nla, struct nlmsgerr *err
 static int prefix_cmp(const void *va, const void *vb)
 {
 	const struct odhcpd_ipaddr *a = va, *b = vb;
-	int ret = 0;
 
-	if (a->prefix == b->prefix) {
-		ret = (ntohl(a->addr.in.s_addr) < ntohl(b->addr.in.s_addr)) ? 1 :
-			(ntohl(a->addr.in.s_addr) > ntohl(b->addr.in.s_addr)) ? -1 : 0;
-	} else
-		ret = a->prefix < b->prefix ? 1 : -1;
+	if (a->prefix_len != b->prefix_len)
+		return a->prefix_len < b->prefix_len ? 1 : -1;
 
-	return ret;
+	if (ntohl(a->addr.in.s_addr) == ntohl(b->addr.in.s_addr))
+		return 0;
+
+	return ntohl(a->addr.in.s_addr) < ntohl(b->addr.in.s_addr) ? 1 : -1;
 }
 
 
@@ -1037,7 +1036,7 @@ int netlink_setup_addr(struct odhcpd_ipaddr *addr,
 	struct nl_msg *msg;
 	struct ifaddrmsg ifa = {
 		.ifa_family = v6 ? AF_INET6 : AF_INET,
-		.ifa_prefixlen = addr->prefix,
+		.ifa_prefixlen = addr->prefix_len,
 		.ifa_flags = 0,
 		.ifa_scope = 0,
 		.ifa_index = ifindex, };
diff --git a/src/odhcpd.c b/src/odhcpd.c
index f67e419..c6bfbc9 100644
--- a/src/odhcpd.c
+++ b/src/odhcpd.c
@@ -695,7 +695,7 @@ void odhcpd_enum_addr6(struct interface *iface, struct dhcpv6_lease *lease,
 
 			addr = in6_from_prefix_and_iid(&addrs[i], lease->assigned_host_id);
 		} else {
-			if (!valid_prefix_length(lease, addrs[i].prefix))
+			if (!valid_prefix_length(lease, addrs[i].prefix_len))
 				continue;
 
 			addr = addrs[i].addr.in6;
diff --git a/src/odhcpd.h b/src/odhcpd.h
index b706831..c1a31b6 100644
--- a/src/odhcpd.h
+++ b/src/odhcpd.h
@@ -85,7 +85,7 @@
 #define ADDR_MATCH_PIO_FILTER(_addr, iface) (odhcpd_bmemcmp(&(_addr)->addr, \
 							    &(iface)->pio_filter_addr, \
 							    (iface)->pio_filter_length) != 0 || \
-					     (_addr)->prefix < (iface)->pio_filter_length)
+					     (_addr)->prefix_len < (iface)->pio_filter_length)
 
 struct interface;
 struct nl_sock;
@@ -162,14 +162,14 @@ struct netevent_handler {
 
 struct odhcpd_ipaddr {
 	union in46_addr addr;
-	uint8_t prefix;
+	uint8_t prefix_len;
 	uint32_t preferred_lt;
 	uint32_t valid_lt;
 
 	union {
 		/* ipv6 only */
 		struct {
-			uint8_t dprefix;
+			uint8_t dprefix_len;
 			bool tentative;
 		};
 
diff --git a/src/router.c b/src/router.c
index f8fa759..d5e30e9 100644
--- a/src/router.c
+++ b/src/router.c
@@ -300,8 +300,13 @@ static bool router_icmpv6_valid(struct sockaddr_in6 *source, uint8_t *data, size
 /* Detect whether a default route exists, also find the source prefixes */
 static bool parse_routes(struct odhcpd_ipaddr *n, ssize_t len)
 {
-	struct odhcpd_ipaddr p = { .addr.in6 = IN6ADDR_ANY_INIT, .prefix = 0,
-					.dprefix = 0, .preferred_lt = 0, .valid_lt = 0};
+	struct odhcpd_ipaddr p = {
+		.addr.in6 = IN6ADDR_ANY_INIT,
+		.prefix_len = 0,
+		.dprefix_len = 0,
+		.preferred_lt = 0,
+		.valid_lt = 0
+	};
 	bool found_default = false;
 	char line[512], ifname[16];
 
@@ -315,16 +320,16 @@ static bool parse_routes(struct odhcpd_ipaddr *n, ssize_t len)
 			found_default = true;
 		} else if (sscanf(line, "%8" SCNx32 "%8" SCNx32 "%*8" SCNx32 "%*8" SCNx32 " %hhx %*s "
 				"%*s 00000000000000000000000000000000 %*s %*s %*s %" SCNx32 " lo",
-				&p.addr.in6.s6_addr32[0], &p.addr.in6.s6_addr32[1], &p.prefix, &rflags) &&
-				p.prefix > 0 && (rflags & RTF_NONEXTHOP) && (rflags & RTF_REJECT)) {
+				&p.addr.in6.s6_addr32[0], &p.addr.in6.s6_addr32[1], &p.prefix_len, &rflags) &&
+				p.prefix_len > 0 && (rflags & RTF_NONEXTHOP) && (rflags & RTF_REJECT)) {
 			// Find source prefixes by scanning through unreachable-routes
 			p.addr.in6.s6_addr32[0] = htonl(p.addr.in6.s6_addr32[0]);
 			p.addr.in6.s6_addr32[1] = htonl(p.addr.in6.s6_addr32[1]);
 
 			for (ssize_t i = 0; i < len; ++i) {
-				if (n[i].prefix <= 64 && n[i].prefix >= p.prefix &&
-						!odhcpd_bmemcmp(&p.addr.in6, &n[i].addr.in6, p.prefix)) {
-					n[i].dprefix = p.prefix;
+				if (n[i].prefix_len <= 64 && n[i].prefix_len >= p.prefix_len &&
+				    !odhcpd_bmemcmp(&p.addr.in6, &n[i].addr.in6, p.prefix_len)) {
+					n[i].dprefix_len = p.prefix_len;
 					break;
 				}
 			}
@@ -416,7 +421,7 @@ struct nd_opt_search_list {
 struct nd_opt_route_info {
 	uint8_t type;
 	uint8_t len;
-	uint8_t prefix;
+	uint8_t prefix_len;
 	uint8_t flags;
 	uint32_t lifetime;
 	uint32_t addr[4];
@@ -451,8 +456,8 @@ static struct ra_pio *router_find_ra_pio(struct interface *iface,
 	for (size_t i = 0; i < iface->pio_cnt; i++) {
 		struct ra_pio *cur_pio = &iface->pios[i];
 
-		if (addr->prefix == cur_pio->length &&
-			!odhcpd_bmemcmp(&addr->addr.in6, &cur_pio->prefix, cur_pio->length))
+		if (addr->prefix_len == cur_pio->length &&
+		    !odhcpd_bmemcmp(&addr->addr.in6, &cur_pio->prefix, cur_pio->length))
 			return cur_pio;
 	}
 
@@ -489,7 +494,7 @@ static void router_add_ra_pio(struct interface *iface,
 	iface->pio_cnt++;
 
 	memcpy(&pio->prefix, &addr->addr.in6, sizeof(pio->prefix));
-	pio->length = addr->prefix;
+	pio->length = addr->prefix_len;
 	pio->lifetime = 0;
 
 	iface->pio_update = true;
@@ -655,8 +660,8 @@ static int send_router_advert(struct interface *iface, const struct in6_addr *fr
 			for (size_t j = 0; j < valid_addr_cnt; j++) {
 				struct odhcpd_ipaddr *cur_addr = &addrs[j];
 
-				if (cur_pio->length == cur_addr->prefix &&
-					!odhcpd_bmemcmp(&cur_pio->prefix, &cur_addr->addr.in6, cur_pio->length)) {
+				if (cur_pio->length == cur_addr->prefix_len &&
+				    !odhcpd_bmemcmp(&cur_pio->prefix, &cur_addr->addr.in6, cur_pio->length)) {
 					pio_found = true;
 					break;
 				}
@@ -666,7 +671,7 @@ static int send_router_advert(struct interface *iface, const struct in6_addr *fr
 				struct odhcpd_ipaddr *addr = &addrs[total_addr_cnt];
 
 				memcpy(&addr->addr.in6, &cur_pio->prefix, sizeof(addr->addr.in6));
-				addr->prefix = cur_pio->length;
+				addr->prefix_len = cur_pio->length;
 				addr->preferred_lt = 0;
 				addr->valid_lt = (uint32_t) (now + ND_VALID_LIMIT);
 				total_addr_cnt++;
@@ -681,9 +686,9 @@ static int send_router_advert(struct interface *iface, const struct in6_addr *fr
 		uint32_t preferred_lt = 0;
 		uint32_t valid_lt = 0;
 
-		if (addr->prefix > 96 || (i < valid_addr_cnt && addr->valid_lt <= (uint32_t)now)) {
+		if (addr->prefix_len > 96 || (i < valid_addr_cnt && addr->valid_lt <= (uint32_t)now)) {
 			info("Address %s (prefix %d, valid-lifetime %u) not suitable as RA prefix on %s",
-			     inet_ntop(AF_INET6, &addr->addr.in6, buf, sizeof(buf)), addr->prefix,
+			     inet_ntop(AF_INET6, &addr->addr.in6, buf, sizeof(buf)), addr->prefix_len,
 			     addr->valid_lt, iface->name);
 			continue;
 		}
@@ -696,9 +701,9 @@ static int send_router_advert(struct interface *iface, const struct in6_addr *fr
 		}
 
 		for (size_t i = 0; i < pfxs_cnt; ++i) {
-			if (addr->prefix == pfxs[i].nd_opt_pi_prefix_len &&
-					!odhcpd_bmemcmp(&pfxs[i].nd_opt_pi_prefix,
-					&addr->addr.in6, addr->prefix))
+			if (addr->prefix_len == pfxs[i].nd_opt_pi_prefix_len &&
+			    !odhcpd_bmemcmp(&pfxs[i].nd_opt_pi_prefix,
+					    &addr->addr.in6, addr->prefix_len))
 				p = &pfxs[i];
 		}
 
@@ -752,17 +757,17 @@ static int send_router_advert(struct interface *iface, const struct in6_addr *fr
 		}
 
 		odhcpd_bmemcpy(&p->nd_opt_pi_prefix, &addr->addr.in6,
-				(iface->ra_advrouter) ? 128 : addr->prefix);
+				(iface->ra_advrouter) ? 128 : addr->prefix_len);
 		p->nd_opt_pi_type = ND_OPT_PREFIX_INFORMATION;
 		p->nd_opt_pi_len = 4;
-		p->nd_opt_pi_prefix_len = (addr->prefix < 64) ? 64 : addr->prefix;
+		p->nd_opt_pi_prefix_len = (addr->prefix_len < 64) ? 64 : addr->prefix_len;
 		/* RFC9762 DHCPv6-PD Preferred Flag § 6:
 		 * Routers SHOULD set the P flag to zero by default...
 		 */
 		p->nd_opt_pi_flags_reserved = 0;
 		if (!iface->ra_not_onlink)
 			p->nd_opt_pi_flags_reserved |= ND_OPT_PI_FLAG_ONLINK;
-		if (iface->ra_slaac && addr->prefix <= 64)
+		if (iface->ra_slaac && addr->prefix_len <= 64)
 			p->nd_opt_pi_flags_reserved |= ND_OPT_PI_FLAG_AUTO;
 		if (iface->dhcpv6 != MODE_DISABLED && iface->dhcpv6_pd && iface->dhcpv6_pd_preferred)
 			/* RFC9762 DHCPv6-PD Preferred Flag
@@ -961,10 +966,10 @@ static int send_router_advert(struct interface *iface, const struct in6_addr *fr
 		struct nd_opt_route_info *tmp;
 		uint32_t valid_lt;
 
-		if (addr->dprefix >= 64 || addr->dprefix == 0 || addr->valid_lt <= (uint32_t)now) {
+		if (addr->dprefix_len >= 64 || addr->dprefix_len == 0 || addr->valid_lt <= (uint32_t)now) {
 			info("Address %s (dprefix %d, valid-lifetime %u) not suitable as RA route on %s",
 			     inet_ntop(AF_INET6, &addr->addr.in6, buf, sizeof(buf)),
-			     addr->dprefix, addr->valid_lt, iface->name);
+			     addr->dprefix_len, addr->valid_lt, iface->name);
 
 			continue; /* Address not suitable */
 		}
@@ -976,10 +981,10 @@ static int send_router_advert(struct interface *iface, const struct in6_addr *fr
 			continue; /* PIO filtered out of this RA */
 		}
 
-		if (addr->dprefix > 32) {
-			addr->addr.in6.s6_addr32[1] &= htonl(~((1U << (64 - addr->dprefix)) - 1));
-		} else if (addr->dprefix <= 32) {
-			addr->addr.in6.s6_addr32[0] &= htonl(~((1U << (32 - addr->dprefix)) - 1));
+		if (addr->dprefix_len > 32) {
+			addr->addr.in6.s6_addr32[1] &= htonl(~((1U << (64 - addr->dprefix_len)) - 1));
+		} else if (addr->dprefix_len <= 32) {
+			addr->addr.in6.s6_addr32[0] &= htonl(~((1U << (32 - addr->dprefix_len)) - 1));
 			addr->addr.in6.s6_addr32[1] = 0;
 		}
 
@@ -994,7 +999,7 @@ static int send_router_advert(struct interface *iface, const struct in6_addr *fr
 		memset(&routes[routes_cnt], 0, sizeof(*routes));
 		routes[routes_cnt].type = ND_OPT_ROUTE_INFO;
 		routes[routes_cnt].len = sizeof(*routes) / 8;
-		routes[routes_cnt].prefix = addr->dprefix;
+		routes[routes_cnt].prefix_len = addr->dprefix_len;
 		routes[routes_cnt].flags = 0;
 		if (iface->route_preference < 0)
 			routes[routes_cnt].flags |= ND_RA_PREF_LOW;