libbpf: Consistent prefixes for interfaces in nlattr.h.

libbpf is used more and more outside kernel tree. That means the library
should follow good practices in library design and implementation to
play well with third party code that uses it.

One of such practices is to have a common prefix (or a few) for every
interface, function or data structure, library provides. I helps to
avoid name conflicts with other libraries and keeps API consistent.

Inconsistent names in libbpf already cause problems in real life. E.g.
an application can't use both libbpf and libnl due to conflicting
symbols.

Having common prefix will help to fix current and avoid future problems.

libbpf already uses the following prefixes for its interfaces:
* bpf_ for bpf system call wrappers, program/map/elf-object
  abstractions and a few other things;
* btf_ for BTF related API;
* libbpf_ for everything else.

The patch adds libbpf_ prefix to interfaces in nlattr.h that use none of
mentioned above prefixes and doesn't fit well into the first two
categories.

Since affected part of API is used in bpftool, the patch applies
corresponding change to bpftool as well. Having it in a separate patch
will cause a state of tree where bpftool is broken what may not be a
good idea.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

1 files changed, 34 insertions, 30 deletions

diff --git a/tools/lib/bpf/nlattr.c b/tools/lib/bpf/nlattr.c
index 49f514119bdb..e52257a7367a 100644
--- a/tools/lib/bpf/nlattr.c
+++ b/tools/lib/bpf/nlattr.c
@@ -17,13 +17,13 @@
 #include <string.h>
 #include <stdio.h>
 
-static uint16_t nla_attr_minlen[NLA_TYPE_MAX+1] = {
-	[NLA_U8]	= sizeof(uint8_t),
-	[NLA_U16]	= sizeof(uint16_t),
-	[NLA_U32]	= sizeof(uint32_t),
-	[NLA_U64]	= sizeof(uint64_t),
-	[NLA_STRING]	= 1,
-	[NLA_FLAG]	= 0,
+static uint16_t nla_attr_minlen[LIBBPF_NLA_TYPE_MAX+1] = {
+	[LIBBPF_NLA_U8]		= sizeof(uint8_t),
+	[LIBBPF_NLA_U16]	= sizeof(uint16_t),
+	[LIBBPF_NLA_U32]	= sizeof(uint32_t),
+	[LIBBPF_NLA_U64]	= sizeof(uint64_t),
+	[LIBBPF_NLA_STRING]	= 1,
+	[LIBBPF_NLA_FLAG]	= 0,
 };
 
 static struct nlattr *nla_next(const struct nlattr *nla, int *remaining)
@@ -47,9 +47,9 @@ static int nla_type(const struct nlattr *nla)
 }
 
 static int validate_nla(struct nlattr *nla, int maxtype,
-			struct nla_policy *policy)
+			struct libbpf_nla_policy *policy)
 {
-	struct nla_policy *pt;
+	struct libbpf_nla_policy *pt;
 	unsigned int minlen = 0;
 	int type = nla_type(nla);
 
@@ -58,23 +58,24 @@ static int validate_nla(struct nlattr *nla, int maxtype,
 
 	pt = &policy[type];
 
-	if (pt->type > NLA_TYPE_MAX)
+	if (pt->type > LIBBPF_NLA_TYPE_MAX)
 		return 0;
 
 	if (pt->minlen)
 		minlen = pt->minlen;
-	else if (pt->type != NLA_UNSPEC)
+	else if (pt->type != LIBBPF_NLA_UNSPEC)
 		minlen = nla_attr_minlen[pt->type];
 
-	if (nla_len(nla) < minlen)
+	if (libbpf_nla_len(nla) < minlen)
 		return -1;
 
-	if (pt->maxlen && nla_len(nla) > pt->maxlen)
+	if (pt->maxlen && libbpf_nla_len(nla) > pt->maxlen)
 		return -1;
 
-	if (pt->type == NLA_STRING) {
-		char *data = nla_data(nla);
-		if (data[nla_len(nla) - 1] != '\0')
+	if (pt->type == LIBBPF_NLA_STRING) {
+		char *data = libbpf_nla_data(nla);
+
+		if (data[libbpf_nla_len(nla) - 1] != '\0')
 			return -1;
 	}
 
@@ -104,15 +105,15 @@ static inline int nlmsg_len(const struct nlmsghdr *nlh)
  * @see nla_validate
  * @return 0 on success or a negative error code.
  */
-int nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head, int len,
-	      struct nla_policy *policy)
+int libbpf_nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head,
+		     int len, struct libbpf_nla_policy *policy)
 {
 	struct nlattr *nla;
 	int rem, err;
 
 	memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
 
-	nla_for_each_attr(nla, head, len, rem) {
+	libbpf_nla_for_each_attr(nla, head, len, rem) {
 		int type = nla_type(nla);
 
 		if (type > maxtype)
@@ -144,23 +145,25 @@ errout:
  * @arg policy          Attribute validation policy.
  *
  * Feeds the stream of attributes nested into the specified attribute
- * to nla_parse().
+ * to libbpf_nla_parse().
  *
- * @see nla_parse
+ * @see libbpf_nla_parse
  * @return 0 on success or a negative error code.
  */
-int nla_parse_nested(struct nlattr *tb[], int maxtype, struct nlattr *nla,
-		     struct nla_policy *policy)
+int libbpf_nla_parse_nested(struct nlattr *tb[], int maxtype,
+			    struct nlattr *nla,
+			    struct libbpf_nla_policy *policy)
 {
-	return nla_parse(tb, maxtype, nla_data(nla), nla_len(nla), policy);
+	return libbpf_nla_parse(tb, maxtype, libbpf_nla_data(nla),
+				libbpf_nla_len(nla), policy);
 }
 
 /* dump netlink extended ack error message */
-int nla_dump_errormsg(struct nlmsghdr *nlh)
+int libbpf_nla_dump_errormsg(struct nlmsghdr *nlh)
 {
-	struct nla_policy extack_policy[NLMSGERR_ATTR_MAX + 1] = {
-		[NLMSGERR_ATTR_MSG]	= { .type = NLA_STRING },
-		[NLMSGERR_ATTR_OFFS]	= { .type = NLA_U32 },
+	struct libbpf_nla_policy extack_policy[NLMSGERR_ATTR_MAX + 1] = {
+		[NLMSGERR_ATTR_MSG]	= { .type = LIBBPF_NLA_STRING },
+		[NLMSGERR_ATTR_OFFS]	= { .type = LIBBPF_NLA_U32 },
 	};
 	struct nlattr *tb[NLMSGERR_ATTR_MAX + 1], *attr;
 	struct nlmsgerr *err;
@@ -181,14 +184,15 @@ int nla_dump_errormsg(struct nlmsghdr *nlh)
 	attr = (struct nlattr *) ((void *) err + hlen);
 	alen = nlh->nlmsg_len - hlen;
 
-	if (nla_parse(tb, NLMSGERR_ATTR_MAX, attr, alen, extack_policy) != 0) {
+	if (libbpf_nla_parse(tb, NLMSGERR_ATTR_MAX, attr, alen,
+			     extack_policy) != 0) {
 		fprintf(stderr,
 			"Failed to parse extended error attributes\n");
 		return 0;
 	}
 
 	if (tb[NLMSGERR_ATTR_MSG])
-		errmsg = (char *) nla_data(tb[NLMSGERR_ATTR_MSG]);
+		errmsg = (char *) libbpf_nla_data(tb[NLMSGERR_ATTR_MSG]);
 
 	fprintf(stderr, "Kernel error message: %s\n", errmsg);