On 8/31/23 8:34 AM, Daan De Meyer wrote:
As prep for adding unix socket support to the cgroup sockaddr hooks, let's add a kfunc bpf_sock_addr_set_unix_addr() that allows modifying a sockaddr from bpf. While this is already possible for AF_INET and AF_INET6, we'll need this kfunc when we add unix socket support since modifying the address for those requires modifying both the address and the sockaddr length. Signed-off-by: Daan De Meyer <daan.j.demeyer@xxxxxxxxx> --- kernel/bpf/btf.c | 1 + net/core/filter.c | 32 +++++++++++++++++++++++++++++++- 2 files changed, 32 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 249657c466dd..15c972f27574 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -7819,6 +7819,7 @@ static int bpf_prog_type_to_kfunc_hook(enum bpf_prog_type prog_type) { switch (prog_type) { case BPF_PROG_TYPE_UNSPEC: + case BPF_PROG_TYPE_CGROUP_SOCK_ADDR: return BTF_KFUNC_HOOK_COMMON; case BPF_PROG_TYPE_XDP: return BTF_KFUNC_HOOK_XDP; diff --git a/net/core/filter.c b/net/core/filter.c index a094694899c9..3ed6cd33b268 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -11752,6 +11752,25 @@ __bpf_kfunc int bpf_dynptr_from_xdp(struct xdp_buff *xdp, u64 flags,return 0;} + +__bpf_kfunc int bpf_sock_addr_set_unix_addr(struct bpf_sock_addr_kern *sa_kern, + const u8 *addr, u32 addrlen__sz) +{ + struct sockaddr *sa = sa_kern->uaddr; + struct sockaddr_un *un; + + if (sa_kern->sk->sk_family != AF_UNIX) + return -EINVAL; + + if (addrlen__sz > UNIX_PATH_MAX)
Is it valid to have addrlen__sz == 0 for AF_UNIX?
+ return -EINVAL; + + un = (struct sockaddr_un *)sa; + memcpy(un->sun_path, addr, addrlen__sz); + sa_kern->uaddrlen = offsetof(struct sockaddr_un, sun_path) + addrlen__sz; + + return 0; +}
