zebra,lib: use const in more apis

Use const with some args to ipaddr, zebra vxlan, mpls
lsp, and nexthop apis; add some extra checks to some
nexthop-related apis.

Signed-off-by: Mark Stapp <mjs@voltanet.io>

9 files changed, 35 insertions, 11 deletions

diff --git a/lib/ipaddr.h b/lib/ipaddr.h
index c6372f1abb..cd7f79a04e 100644
--- a/lib/ipaddr.h
+++ b/lib/ipaddr.h
@@ -112,7 +112,7 @@ static inline void ipv4_to_ipv4_mapped_ipv6(struct in6_addr *in6,
 /*
  * convert an ipv4 mapped ipv6 address back to ipv4 address
  */
-static inline void ipv4_mapped_ipv6_to_ipv4(struct in6_addr *in6,
+static inline void ipv4_mapped_ipv6_to_ipv4(const struct in6_addr *in6,
 					    struct in_addr *in)
 {
 	memset(in, 0, sizeof(struct in_addr));
diff --git a/lib/mpls.c b/lib/mpls.c
index 759fe1206d..ac5792a686 100644
--- a/lib/mpls.c
+++ b/lib/mpls.c
@@ -79,7 +79,7 @@ int mpls_str2label(const char *label_str, uint8_t *num_labels,
 /*
  * Label to string conversion, labels in string separated by '/'.
  */
-char *mpls_label2str(uint8_t num_labels, mpls_label_t *labels, char *buf,
+char *mpls_label2str(uint8_t num_labels, const mpls_label_t *labels, char *buf,
 		     int len, int pretty)
 {
 	char label_buf[BUFSIZ];
diff --git a/lib/mpls.h b/lib/mpls.h
index 635ecc77a1..05cf2935e8 100644
--- a/lib/mpls.h
+++ b/lib/mpls.h
@@ -209,10 +209,13 @@ static inline char *label2str(mpls_label_t label, char *buf, size_t len)
 int mpls_str2label(const char *label_str, uint8_t *num_labels,
 		   mpls_label_t *labels);
 
+/* Generic string buffer for label-stack-to-str */
+#define MPLS_LABEL_STRLEN 1024
+
 /*
  * Label to string conversion, labels in string separated by '/'.
  */
-char *mpls_label2str(uint8_t num_labels, mpls_label_t *labels, char *buf,
+char *mpls_label2str(uint8_t num_labels, const mpls_label_t *labels, char *buf,
 		     int len, int pretty);
 
 #ifdef __cplusplus
diff --git a/lib/nexthop.c b/lib/nexthop.c
index c3be0a71e6..68ce81c293 100644
--- a/lib/nexthop.c
+++ b/lib/nexthop.c
@@ -393,8 +393,8 @@ struct nexthop *nexthop_from_blackhole(enum blackhole_type bh_type)
 }
 
 /* Update nexthop with label information. */
-void nexthop_add_labels(struct nexthop *nexthop, enum lsp_types_t type,
-			uint8_t num_labels, mpls_label_t *label)
+void nexthop_add_labels(struct nexthop *nexthop, enum lsp_types_t ltype,
+			uint8_t num_labels, const mpls_label_t *labels)
 {
 	struct mpls_label_stack *nh_label;
 	int i;
@@ -402,13 +402,18 @@ void nexthop_add_labels(struct nexthop *nexthop, enum lsp_types_t type,
 	if (num_labels == 0)
 		return;
 
-	nexthop->nh_label_type = type;
+	/* Enforce limit on label stack size */
+	if (num_labels > MPLS_MAX_LABELS)
+		num_labels = MPLS_MAX_LABELS;
+
+	nexthop->nh_label_type = ltype;
+
 	nh_label = XCALLOC(MTYPE_NH_LABEL,
 			   sizeof(struct mpls_label_stack)
 				   + num_labels * sizeof(mpls_label_t));
 	nh_label->num_labels = num_labels;
 	for (i = 0; i < num_labels; i++)
-		nh_label->label[i] = *(label + i);
+		nh_label->label[i] = *(labels + i);
 	nexthop->nh_label = nh_label;
 }
 
diff --git a/lib/nexthop.h b/lib/nexthop.h
index 6710914e40..8d7580f6b4 100644
--- a/lib/nexthop.h
+++ b/lib/nexthop.h
@@ -118,13 +118,22 @@ struct nexthop {
 	uint8_t weight;
 };
 
+
+/* Utility to append one nexthop to another. */
+#define NEXTHOP_APPEND(to, new)           \
+	do {                              \
+		(to)->next = (new);       \
+		(new)->prev = (to);       \
+		(new)->next = NULL;       \
+	} while (0)
+
 struct nexthop *nexthop_new(void);
 
 void nexthop_free(struct nexthop *nexthop);
 void nexthops_free(struct nexthop *nexthop);
 
-void nexthop_add_labels(struct nexthop *, enum lsp_types_t, uint8_t,
-			mpls_label_t *);
+void nexthop_add_labels(struct nexthop *nexthop, enum lsp_types_t ltype,
+			uint8_t num_labels, const mpls_label_t *labels);
 void nexthop_del_labels(struct nexthop *);
 
 /*
diff --git a/lib/nexthop_group.c b/lib/nexthop_group.c
index d660428bcd..c6479cf4ff 100644
--- a/lib/nexthop_group.c
+++ b/lib/nexthop_group.c
@@ -225,6 +225,10 @@ void nexthop_group_copy(struct nexthop_group *to,
 
 void nexthop_group_delete(struct nexthop_group **nhg)
 {
+	/* OK to call with NULL group */
+	if ((*nhg) == NULL)
+		return;
+
 	if ((*nhg)->nexthop)
 		nexthops_free((*nhg)->nexthop);
 
diff --git a/lib/nexthop_group.h b/lib/nexthop_group.h
index f99a53f694..76e1e64ca5 100644
--- a/lib/nexthop_group.h
+++ b/lib/nexthop_group.h
@@ -57,6 +57,8 @@ void copy_nexthops(struct nexthop **tnh, const struct nexthop *nh,
 uint32_t nexthop_group_hash_no_recurse(const struct nexthop_group *nhg);
 uint32_t nexthop_group_hash(const struct nexthop_group *nhg);
 void nexthop_group_mark_duplicates(struct nexthop_group *nhg);
+
+/* Add a nexthop to a list, enforcing the canonical sort order. */
 void nexthop_group_add_sorted(struct nexthop_group *nhg,
 			      struct nexthop *nexthop);
 
diff --git a/lib/zclient.c b/lib/zclient.c
index 1ac0e49e13..a8f973ab95 100644
--- a/lib/zclient.c
+++ b/lib/zclient.c
@@ -1388,7 +1388,7 @@ stream_failure:
 	return false;
 }
 
-struct nexthop *nexthop_from_zapi_nexthop(struct zapi_nexthop *znh)
+struct nexthop *nexthop_from_zapi_nexthop(const struct zapi_nexthop *znh)
 {
 	struct nexthop *n = nexthop_new();
 
diff --git a/lib/zclient.h b/lib/zclient.h
index 4de42a35bb..03d0485f90 100644
--- a/lib/zclient.h
+++ b/lib/zclient.h
@@ -769,7 +769,8 @@ bool zapi_iptable_notify_decode(struct stream *s,
 		uint32_t *unique,
 		enum zapi_iptable_notify_owner *note);
 
-extern struct nexthop *nexthop_from_zapi_nexthop(struct zapi_nexthop *znh);
+extern struct nexthop *nexthop_from_zapi_nexthop(
+	const struct zapi_nexthop *znh);
 int zapi_nexthop_from_nexthop(struct zapi_nexthop *znh,
 			      const struct nexthop *nh);
 extern bool zapi_nexthop_update_decode(struct stream *s,