config: log config parse failures to syslog

An invalid config setting for an interface lead to a flush of all config
settings of the related interface and thus made the interface unusable.
Change the behavior by logging config parse failures to syslog and
not flushing all config settings

Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>

2 files changed, 86 insertions, 46 deletions

diff --git a/README b/README
index f9cbb11..bd63b0e 100644
--- a/README
+++ b/README
@@ -136,7 +136,7 @@ ra_retranstime		integer	0			Retransmit Time in milliseconds to be
 							advertised in RA messages
 ra_hoplimit		integer	0			Current hoplimit to be advertised
 							in RA messages
-ra_mtu			integer 0			MTU to be advertised in
+ra_mtu			integer -			MTU to be advertised in
 							RA messages
 ra_dns			bool	1			Announce DNS configuration in
 							RA messages (RFC8106)
diff --git a/src/config.c b/src/config.c
index 78b5855..e46ecb0 100644
--- a/src/config.c
+++ b/src/config.c
@@ -440,6 +440,8 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr
 	struct interface *iface;
 	struct blob_attr *tb[IFACE_ATTR_MAX], *c;
 	bool get_addrs = false;
+	int mode;
+	const char *ifname = NULL;
 
 	blobmsg_parse(iface_attrs, IFACE_ATTR_MAX, tb, data, len);
 
@@ -474,7 +476,6 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr
 		get_addrs = overwrite = true;
 	}
 
-	const char *ifname = NULL;
 	if (overwrite) {
 		if ((c = tb[IFACE_ATTR_IFNAME]))
 			ifname = blobmsg_get_string(c);
@@ -522,18 +523,24 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr
 
 	if ((c = tb[IFACE_ATTR_LEASETIME])) {
 		double time = parse_leasetime(c);
-		if (time < 0)
-			goto err;
 
-		iface->dhcp_leasetime = time;
+		if (time >= 0)
+			iface->dhcp_leasetime = time;
+		else
+			syslog(LOG_ERR, "Invalid %s value configured for interface '%s'",
+			       iface_attrs[IFACE_ATTR_LEASETIME].name, iface->name);
+
 	}
 
 	if ((c = tb[IFACE_ATTR_PREFERRED_LIFETIME])) {
 		double time = parse_leasetime(c);
-		if (time < 0)
-			goto err;
 
-		iface->preferred_lifetime = time;
+		if (time >= 0)
+			iface->preferred_lifetime = time;
+		else
+			syslog(LOG_ERR, "Invalid %s value configured for interface '%s'",
+			       iface_attrs[IFACE_ATTR_PREFERRED_LIFETIME].name, iface->name);
+
 	}
 
 	if ((c = tb[IFACE_ATTR_START])) {
@@ -570,7 +577,6 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr
 		}
 	}
 
-	int mode;
 	if ((c = tb[IFACE_ATTR_RA])) {
 		if ((mode = parse_mode(blobmsg_get_string(c))) >= 0) {
 			iface->ra = mode;
@@ -578,7 +584,8 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr
 			if (iface->ra != MODE_DISABLED)
 				iface->ignore = false;
 		} else
-			goto err;
+			syslog(LOG_ERR, "Invalid %s mode configured for interface '%s'",
+			       iface_attrs[IFACE_ATTR_RA].name, iface->name);
 	}
 
 	if ((c = tb[IFACE_ATTR_DHCPV4])) {
@@ -589,9 +596,9 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr
 				if (iface->dhcpv4 != MODE_DISABLED)
 					iface->ignore = false;
 			}
-		}
-		else
-			goto err;
+		} else
+			syslog(LOG_ERR, "Invalid %s mode configured for interface %s",
+			       iface_attrs[IFACE_ATTR_DHCPV4].name, iface->name);
 	}
 
 	if ((c = tb[IFACE_ATTR_DHCPV6])) {
@@ -601,7 +608,8 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr
 			if (iface->dhcpv6 != MODE_DISABLED)
 				iface->ignore = false;
 		} else
-			goto err;
+			syslog(LOG_ERR, "Invalid %s mode configured for interface '%s'",
+			       iface_attrs[IFACE_ATTR_DHCPV6].name, iface->name);
 	}
 
 	if ((c = tb[IFACE_ATTR_NDP])) {
@@ -611,7 +619,8 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr
 			if (iface->ndp != MODE_DISABLED)
 				iface->ignore = false;
 		} else
-			goto err;
+			syslog(LOG_ERR, "Invalid %s mode configured for interface '%s'",
+			       iface_attrs[IFACE_ATTR_NDP].name, iface->name);
 	}
 
 	if ((c = tb[IFACE_ATTR_ROUTER])) {
@@ -619,10 +628,11 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr
 		unsigned rem;
 
 		blobmsg_for_each_attr(cur, c, rem) {
+			struct in_addr addr4;
+
 			if (blobmsg_type(cur) != BLOBMSG_TYPE_STRING || !blobmsg_check_attr(cur, false))
 				continue;
 
-			struct in_addr addr4;
 			if (inet_pton(AF_INET, blobmsg_get_string(cur), &addr4) == 1) {
 				iface->dhcpv4_router = realloc(iface->dhcpv4_router,
 						(++iface->dhcpv4_router_cnt) * sizeof(*iface->dhcpv4_router));
@@ -631,7 +641,8 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr
 
 				iface->dhcpv4_router[iface->dhcpv4_router_cnt - 1] = addr4;
 			} else
-				goto err;
+				syslog(LOG_ERR, "Invalid %s value configured for interface '%s'",
+				       iface_attrs[IFACE_ATTR_ROUTER].name, iface->name);
 		}
 	}
 
@@ -641,14 +652,19 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr
 
 		iface->always_rewrite_dns = true;
 		blobmsg_for_each_attr(cur, c, rem) {
+			struct in_addr addr4;
+			struct in6_addr addr6;
+
 			if (blobmsg_type(cur) != BLOBMSG_TYPE_STRING || !blobmsg_check_attr(cur, false))
 				continue;
 
-			struct in_addr addr4;
-			struct in6_addr addr6;
 			if (inet_pton(AF_INET, blobmsg_get_string(cur), &addr4) == 1) {
-				if (addr4.s_addr == INADDR_ANY)
-					goto err;
+				if (addr4.s_addr == INADDR_ANY) {
+					syslog(LOG_ERR, "Invalid %s value configured for interface '%s'",
+					       iface_attrs[IFACE_ATTR_DNS].name, iface->name);
+
+					continue;
+				}
 
 				iface->dhcpv4_dns = realloc(iface->dhcpv4_dns,
 						(++iface->dhcpv4_dns_cnt) * sizeof(*iface->dhcpv4_dns));
@@ -657,8 +673,12 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr
 
 				iface->dhcpv4_dns[iface->dhcpv4_dns_cnt - 1] = addr4;
 			} else if (inet_pton(AF_INET6, blobmsg_get_string(cur), &addr6) == 1) {
-				if (IN6_IS_ADDR_UNSPECIFIED(&addr6))
-					goto err;
+				if (IN6_IS_ADDR_UNSPECIFIED(&addr6)) {
+					syslog(LOG_ERR, "Invalid %s value configured for interface '%s'",
+					       iface_attrs[IFACE_ATTR_DNS].name, iface->name);
+
+					continue;
+				}
 
 				iface->dns = realloc(iface->dns,
 						(++iface->dns_cnt) * sizeof(*iface->dns));
@@ -667,7 +687,8 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr
 
 				iface->dns[iface->dns_cnt - 1] = addr6;
 			} else
-				goto err;
+				syslog(LOG_ERR, "Invalid %s value configured for interface '%s'",
+				       iface_attrs[IFACE_ATTR_DNS].name, iface->name);
 		}
 	}
 
@@ -679,18 +700,27 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr
 		unsigned rem;
 
 		blobmsg_for_each_attr(cur, c, rem) {
-			if (blobmsg_type(cur) != BLOBMSG_TYPE_STRING || !blobmsg_check_attr(cur, false))
-				continue;
-
 			uint8_t buf[256];
 			char *domain = blobmsg_get_string(cur);
 			size_t domainlen = strlen(domain);
+			int len;
+
+			if (blobmsg_type(cur) != BLOBMSG_TYPE_STRING || !blobmsg_check_attr(cur, false))
+				continue;
+
+			domain = blobmsg_get_string(cur);
+			domainlen = strlen(domain);
+
 			if (domainlen > 0 && domain[domainlen - 1] == '.')
 				domain[domainlen - 1] = 0;
 
-			int len = dn_comp(domain, buf, sizeof(buf), NULL, NULL);
-			if (len <= 0)
-				goto err;
+			len = dn_comp(domain, buf, sizeof(buf), NULL, NULL);
+			if (len <= 0) {
+				syslog(LOG_ERR, "Invalid %s value configured for interface '%s'",
+				       iface_attrs[IFACE_ATTR_DOMAIN].name, iface->name);
+
+				continue;
+			}
 
 			iface->search = realloc(iface->search, iface->search_len + len);
 			if (!iface->search)
@@ -748,41 +778,49 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr
 	}
 
 	if ((c = tb[IFACE_ATTR_RA_FLAGS])) {
-		iface->ra_flags = 0;
 		if (parse_ra_flags(&iface->ra_flags, c) < 0)
-			goto err;
+			syslog(LOG_ERR, "Invalid %s value configured for interface '%s'",
+			       iface_attrs[IFACE_ATTR_RA_FLAGS].name, iface->name);
 	}
 
 	if ((c = tb[IFACE_ATTR_RA_REACHABLETIME])) {
 		uint32_t ra_reachabletime = blobmsg_get_u32(c);
-		if (ra_reachabletime > 3600000)
-			goto err;
 
-		iface->ra_reachabletime = ra_reachabletime;
+		if (ra_reachabletime <= 3600000)
+			iface->ra_reachabletime = ra_reachabletime;
+		else
+			syslog(LOG_ERR, "Invalid %s value configured for interface '%s'",
+			       iface_attrs[IFACE_ATTR_RA_REACHABLETIME].name, iface->name);
 	}
 
 	if ((c = tb[IFACE_ATTR_RA_RETRANSTIME])) {
 		uint32_t ra_retranstime = blobmsg_get_u32(c);
-		if (ra_retranstime > 60000)
-			goto err;
 
-		iface->ra_retranstime = ra_retranstime;
+		if (ra_retranstime <= 60000)
+			iface->ra_retranstime = ra_retranstime;
+		else
+			syslog(LOG_ERR, "Invalid %s value configured for interface '%s'",
+			       iface_attrs[IFACE_ATTR_RA_RETRANSTIME].name, iface->name);
 	}
 
 	if ((c = tb[IFACE_ATTR_RA_HOPLIMIT])) {
 		uint32_t ra_hoplimit = blobmsg_get_u32(c);
-		if (ra_hoplimit > 255)
-			goto err;
 
-		iface->ra_hoplimit = ra_hoplimit;
+		if (ra_hoplimit <= 255)
+			iface->ra_hoplimit = ra_hoplimit;
+		else
+			syslog(LOG_ERR, "Invalid %s value configured for interface '%s'",
+			       iface_attrs[IFACE_ATTR_RA_HOPLIMIT].name, iface->name);
 	}
 
 	if ((c = tb[IFACE_ATTR_RA_MTU])) {
 		uint32_t ra_mtu = blobmsg_get_u32(c);
-		if (ra_mtu < 1280 || ra_mtu > 65535)
-			goto err;
 
-		iface->ra_mtu = ra_mtu;
+		if (ra_mtu >= 1280 || ra_mtu <= 65535)
+			iface->ra_mtu = ra_mtu;
+		else
+			syslog(LOG_ERR, "Invalid %s value configured for interface '%s'",
+			       iface_attrs[IFACE_ATTR_RA_MTU].name, iface->name);
 	}
 
 	if ((c = tb[IFACE_ATTR_RA_SLAAC]))
@@ -819,7 +857,8 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr
 		else if (!strcmp(prio, "medium") || !strcmp(prio, "default"))
 			iface->route_preference = 0;
 		else
-			goto err;
+			syslog(LOG_ERR, "Invalid %s mode configured for interface '%s'",
+			       iface_attrs[IFACE_ATTR_RA_PREFERENCE].name, iface->name);
 	}
 
 	if ((c = tb[IFACE_ATTR_PD_MANAGER]))
@@ -828,7 +867,8 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr
 
 	if ((c = tb[IFACE_ATTR_PD_CER]) &&
 			inet_pton(AF_INET6, blobmsg_get_string(c), &iface->dhcpv6_pd_cer) < 1)
-		goto err;
+		syslog(LOG_ERR, "Invalid %s value configured for interface '%s'",
+		       iface_attrs[IFACE_ATTR_PD_CER].name, iface->name);
 
 	if ((c = tb[IFACE_ATTR_NDPROXY_ROUTING]))
 		iface->learn_routes = blobmsg_get_bool(c);