diff options
Diffstat (limited to 'tools/lib/bpf/nlattr.h')
| -rw-r--r-- | tools/lib/bpf/nlattr.h | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/tools/lib/bpf/nlattr.h b/tools/lib/bpf/nlattr.h index 6cc3ac91690f..3c780ab6d022 100644 --- a/tools/lib/bpf/nlattr.h +++ b/tools/lib/bpf/nlattr.h @@ -10,7 +10,10 @@ #define __LIBBPF_NLATTR_H #include <stdint.h> +#include <string.h> +#include <errno.h> #include <linux/netlink.h> + /* avoid multiple definition of netlink features */ #define __LINUX_NETLINK_H @@ -103,4 +106,49 @@ int libbpf_nla_parse_nested(struct nlattr *tb[], int maxtype, int libbpf_nla_dump_errormsg(struct nlmsghdr *nlh); +static inline struct nlattr *nla_data(struct nlattr *nla) +{ + return (struct nlattr *)((char *)nla + NLA_HDRLEN); +} + +static inline struct nlattr *nh_tail(struct nlmsghdr *nh) +{ + return (struct nlattr *)((char *)nh + NLMSG_ALIGN(nh->nlmsg_len)); +} + +static inline int nlattr_add(struct nlmsghdr *nh, size_t maxsz, int type, + const void *data, int len) +{ + struct nlattr *nla; + + if (NLMSG_ALIGN(nh->nlmsg_len) + NLA_ALIGN(NLA_HDRLEN + len) > maxsz) + return -EMSGSIZE; + if (!!data != !!len) + return -EINVAL; + + nla = nh_tail(nh); + nla->nla_type = type; + nla->nla_len = NLA_HDRLEN + len; + if (data) + memcpy(nla_data(nla), data, len); + nh->nlmsg_len = NLMSG_ALIGN(nh->nlmsg_len) + NLA_ALIGN(nla->nla_len); + return 0; +} + +static inline struct nlattr *nlattr_begin_nested(struct nlmsghdr *nh, + size_t maxsz, int type) +{ + struct nlattr *tail; + + tail = nh_tail(nh); + if (nlattr_add(nh, maxsz, type | NLA_F_NESTED, NULL, 0)) + return NULL; + return tail; +} + +static inline void nlattr_end_nested(struct nlmsghdr *nh, struct nlattr *tail) +{ + tail->nla_len = (char *)nh_tail(nh) - (char *)tail; +} + #endif /* __LIBBPF_NLATTR_H */ |