Extend bpf_xdp_query routine in order to get XDP/XSK supported features
of netdev over route netlink interface.
Extend libbpf netlink implementation in order to support netlink_generic
protocol.
Co-developed-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>
Co-developed-by: Marek Majtyka <alardam@xxxxxxxxx>
Signed-off-by: Marek Majtyka <alardam@xxxxxxxxx>
Signed-off-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx>
---
tools/lib/bpf/libbpf.h | 3 +-
tools/lib/bpf/netlink.c | 96 +++++++++++++++++++++++++++++++++++++++++
tools/lib/bpf/nlattr.h | 12 ++++++
3 files changed, 110 insertions(+), 1 deletion(-)
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 8777ff21ea1d..b18581277eb2 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -1048,9 +1048,10 @@ struct bpf_xdp_query_opts {
__u32 hw_prog_id; /* output */
__u32 skb_prog_id; /* output */
__u8 attach_mode; /* output */
+ __u64 feature_flags; /* output */
size_t :0;
};
-#define bpf_xdp_query_opts__last_field attach_mode
+#define bpf_xdp_query_opts__last_field feature_flags
LIBBPF_API int bpf_xdp_attach(int ifindex, int prog_fd, __u32 flags,
const struct bpf_xdp_attach_opts *opts);
diff --git a/tools/lib/bpf/netlink.c b/tools/lib/bpf/netlink.c
index d2468a04a6c3..32b13b7a11b0 100644
--- a/tools/lib/bpf/netlink.c
+++ b/tools/lib/bpf/netlink.c
@@ -9,6 +9,7 @@
#include <linux/if_ether.h>
#include <linux/pkt_cls.h>
#include <linux/rtnetlink.h>
+#include <linux/netdev.h>
#include <sys/socket.h>
#include <errno.h>
#include <time.h>
@@ -39,6 +40,12 @@ struct xdp_id_md {
int ifindex;
__u32 flags;
struct xdp_link_info info;
+ __u64 feature_flags;
+};
+
+struct xdp_features_md {
+ int ifindex;
+ __u64 flags;
};
static int libbpf_netlink_open(__u32 *nl_pid, int proto)
@@ -238,6 +245,43 @@ static int libbpf_netlink_send_recv(struct libbpf_nla_req *req,
return ret;
}
+static int parse_genl_family_id(struct nlmsghdr *nh, libbpf_dump_nlmsg_t fn,
+ void *cookie)
+{
+ struct genlmsghdr *gnl = NLMSG_DATA(nh);
+ struct nlattr *na = (struct nlattr *)((void *)gnl + GENL_HDRLEN);
+ struct nlattr *tb[CTRL_ATTR_FAMILY_ID + 1];
+ __u16 *id = cookie;
+
+ libbpf_nla_parse(tb, CTRL_ATTR_FAMILY_ID, na,
+ NLMSG_PAYLOAD(nh, sizeof(*gnl)), NULL);
+ if (!tb[CTRL_ATTR_FAMILY_ID])
+ return NL_CONT;
+
+ *id = libbpf_nla_getattr_u16(tb[CTRL_ATTR_FAMILY_ID]);
+ return NL_DONE;
+}
+
+static int libbpf_netlink_resolve_genl_family_id(const char *name,
+ __u16 len, __u16 *id)
+{
+ struct libbpf_nla_req req = {
+ .nh.nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN),
+ .nh.nlmsg_type = GENL_ID_CTRL,
+ .nh.nlmsg_flags = NLM_F_REQUEST,
+ .gnl.cmd = CTRL_CMD_GETFAMILY,
+ .gnl.version = 2,
+ };
+ int err;
+
+ err = nlattr_add(&req, CTRL_ATTR_FAMILY_NAME, name, len);
+ if (err < 0)
+ return err;
+
+ return libbpf_netlink_send_recv(&req, NETLINK_GENERIC,
+ parse_genl_family_id, NULL, id);
+}
+
static int __bpf_set_link_xdp_fd_replace(int ifindex, int fd, int old_fd,
__u32 flags)
{
@@ -357,6 +401,29 @@ static int get_xdp_info(void *cookie, void *msg, struct nlattr **tb)
return 0;
}
+static int parse_xdp_features(struct nlmsghdr *nh, libbpf_dump_nlmsg_t fn,
+ void *cookie)
+{
+ struct genlmsghdr *gnl = NLMSG_DATA(nh);
+ struct nlattr *na = (struct nlattr *)((void *)gnl + GENL_HDRLEN);
+ struct nlattr *tb[NETDEV_CMD_MAX + 1];
+ struct xdp_features_md *md = cookie;
+ __u32 ifindex;
+
+ libbpf_nla_parse(tb, NETDEV_CMD_MAX, na,
+ NLMSG_PAYLOAD(nh, sizeof(*gnl)), NULL);
+
+ if (!tb[NETDEV_A_DEV_IFINDEX] || !tb[NETDEV_A_DEV_XDP_FEATURES])
+ return NL_CONT;
+
+ ifindex = libbpf_nla_getattr_u32(tb[NETDEV_A_DEV_IFINDEX]);
+ if (ifindex != md->ifindex)
+ return NL_CONT;
+
+ md->flags = libbpf_nla_getattr_u64(tb[NETDEV_A_DEV_XDP_FEATURES]);
+ return NL_DONE;
+}
+
int bpf_xdp_query(int ifindex, int xdp_flags, struct bpf_xdp_query_opts *opts)
{
struct libbpf_nla_req req = {
@@ -366,6 +433,10 @@ int bpf_xdp_query(int ifindex, int xdp_flags, struct bpf_xdp_query_opts *opts)
.ifinfo.ifi_family = AF_PACKET,
};
struct xdp_id_md xdp_id = {};
+ struct xdp_features_md md = {
+ .ifindex = ifindex,
+ };
+ __u16 id;
int err;
if (!OPTS_VALID(opts, bpf_xdp_query_opts))
@@ -393,6 +464,31 @@ int bpf_xdp_query(int ifindex, int xdp_flags, struct bpf_xdp_query_opts *opts)
OPTS_SET(opts, skb_prog_id, xdp_id.info.skb_prog_id);
OPTS_SET(opts, attach_mode, xdp_id.info.attach_mode);
+ if (!OPTS_HAS(opts, feature_flags))
+ return 0;
+
+ err = libbpf_netlink_resolve_genl_family_id("netdev", sizeof("netdev"), &id);
+ if (err < 0)
+ return libbpf_err(err);
+
+ memset(&req, 0, sizeof(req));
+ req.nh.nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN);
+ req.nh.nlmsg_flags = NLM_F_REQUEST;
+ req.nh.nlmsg_type = id;
+ req.gnl.cmd = NETDEV_CMD_DEV_GET;
+ req.gnl.version = 2;
+
+ err = nlattr_add(&req, NETDEV_A_DEV_IFINDEX, &ifindex, sizeof(ifindex));
+ if (err < 0)
+ return err;
+
+ err = libbpf_netlink_send_recv(&req, NETLINK_GENERIC,
+ parse_xdp_features, NULL, &md);
+ if (err)
+ return libbpf_err(err);
+
+ opts->feature_flags = md.flags;
+
return 0;
}
diff --git a/tools/lib/bpf/nlattr.h b/tools/lib/bpf/nlattr.h
index 4d15ae2ff812..d92d1c1de700 100644
--- a/tools/lib/bpf/nlattr.h
+++ b/tools/lib/bpf/nlattr.h
@@ -14,6 +14,7 @@
#include <errno.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
+#include <linux/genetlink.h>
/* avoid multiple definition of netlink features */
#define __LINUX_NETLINK_H
@@ -58,6 +59,7 @@ struct libbpf_nla_req {
union {
struct ifinfomsg ifinfo;
struct tcmsg tc;
+ struct genlmsghdr gnl;
};
char buf[128];
};
@@ -89,11 +91,21 @@ static inline uint8_t libbpf_nla_getattr_u8(const struct nlattr *nla)
return *(uint8_t *)libbpf_nla_data(nla);
}
+static inline uint16_t libbpf_nla_getattr_u16(const struct nlattr *nla)
+{
+ return *(uint16_t *)libbpf_nla_data(nla);
+}
+
static inline uint32_t libbpf_nla_getattr_u32(const struct nlattr *nla)
{
return *(uint32_t *)libbpf_nla_data(nla);
}
+static inline uint64_t libbpf_nla_getattr_u64(const struct nlattr *nla)
+{
+ return *(uint64_t *)libbpf_nla_data(nla);
+}
+
static inline const char *libbpf_nla_getattr_str(const struct nlattr *nla)
{
return (const char *)libbpf_nla_data(nla);
--
2.39.1
