diff options
| author | Toke Høiland-Jørgensen <toke@redhat.com> | 2020-03-25 18:23:28 +0100 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-03-28 14:24:41 -0700 |
| commit | bd5ca3ef93cd8fb7e913f15eeb78e67a0d802274 (patch) | |
| tree | 20b66080e37c4e8fb4686963675ef38f6ef9c10d /tools/lib/bpf | |
| parent | 50a3e678b58ae9535f9e536f2889649b624943c3 (diff) | |
libbpf: Add function to set link XDP fd while specifying old program
This adds a new function to set the XDP fd while specifying the FD of the
program to replace, using the newly added IFLA_XDP_EXPECTED_FD netlink
parameter. The new function uses the opts struct mechanism to be extendable
in the future.
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/158515700857.92963.7052131201257841700.stgit@toke.dk
Diffstat (limited to 'tools/lib/bpf')
| -rw-r--r-- | tools/lib/bpf/libbpf.h | 8 | ||||
| -rw-r--r-- | tools/lib/bpf/libbpf.map | 1 | ||||
| -rw-r--r-- | tools/lib/bpf/netlink.c | 34 |
3 files changed, 42 insertions, 1 deletions
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index d38d7a629417..bf7a35a9556d 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -444,7 +444,15 @@ struct xdp_link_info { __u8 attach_mode; }; +struct bpf_xdp_set_link_opts { + size_t sz; + __u32 old_fd; +}; +#define bpf_xdp_set_link_opts__last_field old_fd + LIBBPF_API int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags); +LIBBPF_API int bpf_set_link_xdp_fd_opts(int ifindex, int fd, __u32 flags, + const struct bpf_xdp_set_link_opts *opts); LIBBPF_API int bpf_get_link_xdp_id(int ifindex, __u32 *prog_id, __u32 flags); LIBBPF_API int bpf_get_link_xdp_info(int ifindex, struct xdp_link_info *info, size_t info_size, __u32 flags); diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 5129283c0284..dcc87db3ca8a 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -244,4 +244,5 @@ LIBBPF_0.0.8 { bpf_link__pin_path; bpf_link__unpin; bpf_program__set_attach_target; + bpf_set_link_xdp_fd_opts; } LIBBPF_0.0.7; diff --git a/tools/lib/bpf/netlink.c b/tools/lib/bpf/netlink.c index 431bd25c6cdb..18b5319025e1 100644 --- a/tools/lib/bpf/netlink.c +++ b/tools/lib/bpf/netlink.c @@ -132,7 +132,8 @@ done: return ret; } -int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags) +static int __bpf_set_link_xdp_fd_replace(int ifindex, int fd, int old_fd, + __u32 flags) { int sock, seq = 0, ret; struct nlattr *nla, *nla_xdp; @@ -178,6 +179,14 @@ int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags) nla->nla_len += nla_xdp->nla_len; } + if (flags & XDP_FLAGS_REPLACE) { + nla_xdp = (struct nlattr *)((char *)nla + nla->nla_len); + nla_xdp->nla_type = IFLA_XDP_EXPECTED_FD; + nla_xdp->nla_len = NLA_HDRLEN + sizeof(old_fd); + memcpy((char *)nla_xdp + NLA_HDRLEN, &old_fd, sizeof(old_fd)); + nla->nla_len += nla_xdp->nla_len; + } + req.nh.nlmsg_len += NLA_ALIGN(nla->nla_len); if (send(sock, &req, req.nh.nlmsg_len, 0) < 0) { @@ -191,6 +200,29 @@ cleanup: return ret; } +int bpf_set_link_xdp_fd_opts(int ifindex, int fd, __u32 flags, + const struct bpf_xdp_set_link_opts *opts) +{ + int old_fd = -1; + + if (!OPTS_VALID(opts, bpf_xdp_set_link_opts)) + return -EINVAL; + + if (OPTS_HAS(opts, old_fd)) { + old_fd = OPTS_GET(opts, old_fd, -1); + flags |= XDP_FLAGS_REPLACE; + } + + return __bpf_set_link_xdp_fd_replace(ifindex, fd, + old_fd, + flags); +} + +int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags) +{ + return __bpf_set_link_xdp_fd_replace(ifindex, fd, 0, flags); +} + static int __dump_link_nlmsg(struct nlmsghdr *nlh, libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie) { |