lua: allow a hostname and pool to define a lease time

The default of 3600 isn't great for testing so this change
is good for me too!

Author: rsmarples

README.md

@@ -61,8 +61,10 @@ Here is an example of how to use it.
 local domain = 'internal'
 
 -- Lookup table to match hostname to IP address.
+-- Return a table of IP address and lease time to specify a lease time per host.
 local hostnames = {
 	['netbsd'] = '10.73.1.70',
+	['freebsd'] = { '10.73.1.71', 30 },
 }
 
 -- Lookup table to match ethernet to hostnames.
@@ -102,13 +104,15 @@ end
 -- You can return a single table with address, netmask, from and to
 -- or a table of the above table (ie an array).
 -- Each address MUST exist on the interface.
+-- Setting a lease_time for the pool is optional.
 function configure_pools(if_name)
 	if if_name == 'bridge0' then
 		return {
 			address = '10.73.1.1',
 			netmask = '255.255.255.0',
 			from = '10.73.1.100',
 			to = '10.73.1.200',
+			lease_time = 3600,
 		}
 	end
 end

src/Makefile

@@ -61,6 +61,9 @@ ${TOP}/vendor/rbtree.o:
 ${PROG}: ${DEPEND} ${OBJS}
 	${CC} ${LDFLAGS} -o $@ ${OBJS} ${LDADD}
 
+lint: _lint
+	for x in ${SUBDIRS}; do ${MAKE} -C $$x $@ || exit $$?; done
+
 proginstall: ${PROG}
 	${INSTALL} -d ${DESTDIR}${SBINDIR}
 	${INSTALL} -m ${BINMODE} ${PROG} ${DESTDIR}${SBINDIR}

src/Makefile.inc

@@ -10,7 +10,7 @@ format:
 	find . -iname "*.c" -o -iname "*.h" -not -name verstable.h | \
 		xargs clang-format -i
 
-lint:
+_lint:
 	clang-tidy ${SRCS} -- ${CPPFLAGS} ${CFLAGS} -isystem ${TOP}/vendor
 
 include ${TOP}/Makefile.inc

src/dhcp.c

@@ -502,8 +502,8 @@ dhcp_plugin_validateaddr(struct ctx *ctx, const struct in_addr *addr)
 }
 
 static struct in_addr
-dhcp_plugin_findaddr(struct ctx *ctx, char *hostname, const struct bootp *bootp,
-    size_t len)
+dhcp_plugin_findaddr(struct ctx *ctx, char *hostname, uint32_t *ltime,
+    const struct bootp *bootp, size_t len)
 {
 	struct plugin *p;
 	struct sockaddr_in sin = {
@@ -517,6 +517,9 @@ dhcp_plugin_findaddr(struct ctx *ctx, char *hostname, const struct bootp *bootp,
 	const char *hname = NULL;
 	size_t l;
 
+	/* We might not get a least time so set to zero for a default. */
+	*ltime = 0;
+
 	PLUGIN_FOREACH(ctx, p)
 	{
 		if (p->p_lookup_hostname == NULL)
@@ -547,8 +550,8 @@ dhcp_plugin_findaddr(struct ctx *ctx, char *hostname, const struct bootp *bootp,
 	{
 		if (p->p_lookup_addr == NULL)
 			continue;
-		err = p->p_lookup_addr(p, (struct sockaddr *)&sin, hname, bootp,
-		    len);
+		err = p->p_lookup_addr(p, (struct sockaddr *)&sin, ltime, hname,
+		    bootp, len);
 		if (err == -1) {
 			if (errno != ESRCH && errno != ENOSYS)
 				logerr("plugin %s", p->p_name);
@@ -787,10 +790,17 @@ dhcp_addoptions(struct bootp *bootp, uint8_t **p, const uint8_t *e,
 	DHCP_PUT_B(p, e, DHO_MESSAGETYPE, type);
 	DHCP_PUT_U32(p, e, DHO_SERVERID, pool->dp_addr.s_addr);
 	if (type == DHCP_OFFER || type == DHCP_ACK) {
-		uint32_t u32, lease_time = ctx->dhcp_lease_time;
+		uint32_t u32, lease_time;
 		struct plugin *plug;
 		int n;
 
+		if (pool->dp_lease_time != 0)
+			lease_time = pool->dp_lease_time;
+		else
+			lease_time = ctx->dhcp_lease_time;
+
+		/* Allow the client to request a shorter leasetime
+		 * but not a longer one. */
 		opt = dhcp_findoption(req, reqlen, DHO_LEASETIME);
 		if (opt != NULL && opt[0] == sizeof(u32)) {
 			memcpy(&u32, opt + 1, sizeof(u32));
@@ -988,17 +998,23 @@ dhcp_set_expire_timeout(struct dhcp_ctx *ctx)
 
 static void
 dhcp_lease_settime(struct dhcp_ctx *ctx, struct dhcp_lease *lease,
-    struct timespec *now, const struct bootp *bootp, size_t len)
+    struct timespec *now, uint32_t lease_time, const struct bootp *bootp,
+    size_t len)
 {
 	const uint8_t *opt;
-	uint32_t u32, lease_time = ctx->dhcp_lease_time;
 
-	opt = dhcp_findoption(bootp, len, DHO_LEASETIME);
-	if (opt != NULL && opt[0] == sizeof(u32)) {
-		memcpy(&u32, opt + 1, sizeof(u32));
-		u32 = ntohl(u32);
-		if (u32 < lease_time)
-			lease_time = u32;
+	if (lease_time == 0) {
+		uint32_t u32;
+
+		lease_time = ctx->dhcp_lease_time;
+
+		opt = dhcp_findoption(bootp, len, DHO_LEASETIME);
+		if (opt != NULL && opt[0] == sizeof(u32)) {
+			memcpy(&u32, opt + 1, sizeof(u32));
+			u32 = ntohl(u32);
+			if (u32 < lease_time)
+				lease_time = u32;
+		}
 	}
 
 	if (lease->dl_in_expire_tree) {
@@ -1095,6 +1111,7 @@ dhcp_handlebootp(struct interface *ifp, struct bootp *bootp, size_t len,
 	uint8_t type, clientid[DHCP_CLIENTID_LEN + 1], fqdn_flags;
 	struct in_addr addr = { .s_addr = INADDR_ANY };
 	char phostname[DHCP_HOSTNAME_LEN] = { '\0' };
+	uint32_t pltime = 0;
 	struct in_addr paddr = { .s_addr = INADDR_ANY };
 	struct dhcp_lease *lease = NULL, *wanted = NULL;
 	char clid_buf[sizeof(clientid) * 3];
@@ -1153,8 +1170,10 @@ dhcp_handlebootp(struct interface *ifp, struct bootp *bootp, size_t len,
 		clientid[0] = bootp->hlen + 1;
 		clientid[1] = bootp->htype;
 		memcpy(clientid + 2, bootp->chaddr, bootp->hlen);
-	} else
+	} else {
 		clientid[0] = '\0';
+		clientid[1] = '\0'; /* silences maybe uninitialiased warning */
+	}
 
 	clid = hwaddr_ntoa(clientid + 1, clientid[0], clid_buf,
 	    sizeof(clid_buf));
@@ -1170,7 +1189,7 @@ dhcp_handlebootp(struct interface *ifp, struct bootp *bootp, size_t len,
 			return;
 		if (lease->dl_addr.s_addr == INADDR_ANY) {
 			lease->dl_addr = dhcp_plugin_findaddr(ifp->if_ctx,
-			    phostname, bootp, len);
+			    phostname, &pltime, bootp, len);
 			if (lease->dl_addr.s_addr != INADDR_ANY)
 				lease->dl_flags |= DL_PLUGIN_ADDRESS;
 		}
@@ -1260,8 +1279,8 @@ dhcp_handlebootp(struct interface *ifp, struct bootp *bootp, size_t len,
 		}
 		/* FALLTHROUGH */
 	case DHCP_REQUEST:
-		paddr = dhcp_plugin_findaddr(ifp->if_ctx, phostname, bootp,
-		    len);
+		paddr = dhcp_plugin_findaddr(ifp->if_ctx, phostname, &pltime,
+		    bootp, len);
 		if (paddr.s_addr == INADDR_ANY)
 			break;
 		wanted = dhcp_lease_findaddr(ctx, &paddr);
@@ -1365,7 +1384,7 @@ dhcp_handlebootp(struct interface *ifp, struct bootp *bootp, size_t len,
 			expires = lease->dl_expires;
 		else
 			timespecclear(&expires);
-		dhcp_lease_settime(ctx, lease, &now, bootp, len);
+		dhcp_lease_settime(ctx, lease, &now, pltime, bootp, len);
 		if (wanted != lease) {
 			if (dhcp_lease_insertaddr(ctx, lease) == -1) {
 				logerr("%s: dhcp_lease_insertaddr", __func__);
@@ -1417,7 +1436,7 @@ dhcp_handlebootp(struct interface *ifp, struct bootp *bootp, size_t len,
 			lease->dl_flags |= DL_PLUGIN_ADDRESS;
 		else
 			lease->dl_flags &= ~DL_PLUGIN_ADDRESS;
-		dhcp_lease_settime(ctx, lease, &now, bootp, len);
+		dhcp_lease_settime(ctx, lease, &now, pltime, bootp, len);
 		if (wanted != lease) {
 			if (dhcp_lease_insertaddr(ctx, lease) == -1) {
 				logerr("%s: dhcp_lease_insertaddr", __func__);
@@ -1557,7 +1576,6 @@ dhcp_handlebootp(struct interface *ifp, struct bootp *bootp, size_t len,
 			if (lease->dl_hostname[0] != '\0')
 				lease->dl_flags |= DL_HOSTNAME;
 		}
-		dhcp_commit_lease(ctx, lease, bootp, len);
 		break;
 	}
 
@@ -1567,6 +1585,10 @@ dhcp_handlebootp(struct interface *ifp, struct bootp *bootp, size_t len,
 	case DHCP_ACK:
 	case DHCP_NAK:
 		dhcp_output(ifp, lease, type, msg, bootp, len);
+		/* Commit the lease after sending it as it might
+		 * be a slow operation depending on what the plugins do. */
+		if (type != DHCP_NAK)
+			dhcp_commit_lease(ctx, lease, bootp, len);
 		break;
 	}
 }

src/dhcp.h

@@ -157,6 +157,7 @@ struct dhcp_pool {
 	struct in_addr dp_mask;
 	struct in_addr dp_from;
 	struct in_addr dp_to;
+	uint32_t dp_lease_time;
 };
 
 #define DHCP_CLIENTID_LEN 1 + 255 /* first byte is length */

src/plugin.h

@@ -48,8 +48,8 @@ struct plugin {
 	int (*p_init_proto)(struct plugin *);
 	int (*p_unload)(struct plugin *);
 	ssize_t (*p_configure_pools)(struct plugin *, struct interface *ifp);
-	int (*p_lookup_addr)(struct plugin *, struct sockaddr *, const char *,
-	    const struct bootp *, size_t);
+	int (*p_lookup_addr)(struct plugin *, struct sockaddr *, uint32_t *,
+	    const char *, const struct bootp *, size_t);
 	int (*p_lookup_hostname)(struct plugin *, char *, const struct bootp *,
 	    size_t);
 	int (*p_addr_to_hostname)(struct plugin *, const struct sockaddr *sa);

src/plugins/Makefile

@@ -48,6 +48,8 @@ lua.So:
 lua.so: lua.So
 	${CC} ${LDFLAGS} -shared -Wl,-x -o $@ -Wl,-soname,$@ lua.So ${LUA_LIBS}
 
+lint: _lint
+
 proginstall: ${PLUGS}
 	${INSTALL} -d ${DESTDIR}${PLUGINDIR}
 	${INSTALL} -m ${BINMODE} ${PROG} ${PLUGS} ${DESTDIR}${PLUGINDIR}

src/plugins/addrinfo.c

@@ -50,7 +50,8 @@ static const char addrinfo_description[] =
 
 static int
 addrinfo_lookup_addr(struct plugin *p, struct sockaddr *sa,
-    const char *hostname, const struct bootp *bootp, size_t bootplen)
+    __unused uint32_t *ltime, const char *hostname, const struct bootp *bootp,
+    size_t bootplen)
 {
 	const uint8_t *opt;
 	char hname[MAXHOSTNAMELEN + 1];

src/plugins/icmp.c

@@ -88,7 +88,7 @@ struct icmp_hold {
 struct icmp_ctx {
 	struct ctx *i_ctx;
 	int i_fd;
-	uint8_t *i_buf;
+	void *i_buf;
 	size_t i_buflen;
 	icmp_addr_map i_hold;
 #ifdef HAVE_CASPER
@@ -119,6 +119,7 @@ icmp_echo_request(void *arg)
 		.icmp_seq = htons(ih->ih_nrequests),
 	};
 	struct sockaddr *sa = (struct sockaddr *)&ih->ih_sin;
+	socklen_t salen = (socklen_t)sa_len(sa);
 
 	icmp.icmp_cksum = in_cksum(&icmp, sizeof(icmp), NULL);
 	if (icmp.icmp_cksum == 0)
@@ -132,13 +133,12 @@ icmp_echo_request(void *arg)
 	logdebugx("%s: echo request: %s %u", icmp_name,
 	    inet_ntoa(ih->ih_sin.sin_addr), ih->ih_id);
 #ifdef HAVE_CASPER
-	if (cap_connect(ctx->i_ctx->ctx_capnet, ctx->i_capfd, sa, sa_len(sa)) ==
-	    -1)
+	if (cap_connect(ctx->i_ctx->ctx_capnet, ctx->i_capfd, sa, salen) == -1)
 		logerr("%s: cap_connect", __func__);
 	else if (send(ctx->i_capfd, &icmp, sizeof(icmp), 0) == -1)
 		logerr("%s: send", __func__);
 #else
-	if (sendto(ctx->i_fd, &icmp, sizeof(icmp), 0, sa, sa_len(sa)) == -1)
+	if (sendto(ctx->i_fd, &icmp, sizeof(icmp), 0, sa, salen) == -1)
 		logerr("%s: sendto", __func__);
 #endif
 }
@@ -230,7 +230,7 @@ icmp_read0(struct icmp_ctx *ctx, int fd, unsigned short e)
 		return;
 	}
 
-	icmp = (struct icmp *)(ctx->i_buf + hlen);
+	icmp = (struct icmp *)(void *)((uint8_t *)ctx->i_buf + hlen);
 	if (icmp->icmp_type != ICMP_ECHOREPLY)
 		return;
 

src/plugins/leasefile.c

@@ -86,10 +86,12 @@ lf_write_lease(void *arg, struct dhcp_lease *lease)
 	char clientidbuf[lease->dl_clientid[0] * 3];
 	const char *clientid, *flags;
 
-	gmtime_r(&lease->dl_leased.tv_sec, &leased);
+	if (gmtime_r(&lease->dl_leased.tv_sec, &leased) == NULL)
+		return -1;
 	if (strftime(sleased, sizeof(sleased), ISO8061_FMT, &leased) == 0)
 		return -1;
-	gmtime_r(&lease->dl_expires.tv_sec, &expires);
+	if (gmtime_r(&lease->dl_expires.tv_sec, &expires) == NULL)
+		return -1;
 	if (strftime(sexpires, sizeof(sexpires), ISO8061_FMT, &expires) == 0)
 		return -1;