From fefba7d1ae198dcbf8b3b432de46a4e29f8dbd8c Mon Sep 17 00:00:00 2001 From: Daan De Meyer Date: Wed, 11 Oct 2023 20:51:04 +0200 Subject: bpf: Propagate modified uaddrlen from cgroup sockaddr programs As prep for adding unix socket support to the cgroup sockaddr hooks, let's propagate the sockaddr length back to the caller after running a bpf cgroup sockaddr hook program. While not important for AF_INET or AF_INET6, the sockaddr length is important when working with AF_UNIX sockaddrs as the size of the sockaddr cannot be determined just from the address family or the sockaddr's contents. __cgroup_bpf_run_filter_sock_addr() is modified to take the uaddrlen as an input/output argument. After running the program, the modified sockaddr length is stored in the uaddrlen pointer. Signed-off-by: Daan De Meyer Link: https://lore.kernel.org/r/20231011185113.140426-3-daan.j.demeyer@gmail.com Signed-off-by: Martin KaFai Lau --- net/ipv6/af_inet6.c | 9 +++++---- net/ipv6/ping.c | 2 +- net/ipv6/tcp_ipv6.c | 2 +- net/ipv6/udp.c | 6 ++++-- 4 files changed, 11 insertions(+), 8 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c index 6337fb4504fd..c35d302a3da9 100644 --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -454,7 +454,7 @@ int inet6_bind_sk(struct sock *sk, struct sockaddr *uaddr, int addr_len) /* BPF prog is run before any checks are done so that if the prog * changes context in a wrong way it will be caught. */ - err = BPF_CGROUP_RUN_PROG_INET_BIND_LOCK(sk, uaddr, + err = BPF_CGROUP_RUN_PROG_INET_BIND_LOCK(sk, uaddr, &addr_len, CGROUP_INET6_BIND, &flags); if (err) return err; @@ -520,6 +520,7 @@ int inet6_getname(struct socket *sock, struct sockaddr *uaddr, int peer) { struct sockaddr_in6 *sin = (struct sockaddr_in6 *)uaddr; + int sin_addr_len = sizeof(*sin); struct sock *sk = sock->sk; struct inet_sock *inet = inet_sk(sk); struct ipv6_pinfo *np = inet6_sk(sk); @@ -539,7 +540,7 @@ int inet6_getname(struct socket *sock, struct sockaddr *uaddr, sin->sin6_addr = sk->sk_v6_daddr; if (inet6_test_bit(SNDFLOW, sk)) sin->sin6_flowinfo = np->flow_label; - BPF_CGROUP_RUN_SA_PROG(sk, (struct sockaddr *)sin, + BPF_CGROUP_RUN_SA_PROG(sk, (struct sockaddr *)sin, &sin_addr_len, CGROUP_INET6_GETPEERNAME); } else { if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) @@ -547,13 +548,13 @@ int inet6_getname(struct socket *sock, struct sockaddr *uaddr, else sin->sin6_addr = sk->sk_v6_rcv_saddr; sin->sin6_port = inet->inet_sport; - BPF_CGROUP_RUN_SA_PROG(sk, (struct sockaddr *)sin, + BPF_CGROUP_RUN_SA_PROG(sk, (struct sockaddr *)sin, &sin_addr_len, CGROUP_INET6_GETSOCKNAME); } sin->sin6_scope_id = ipv6_iface_scope_id(&sin->sin6_addr, sk->sk_bound_dev_if); release_sock(sk); - return sizeof(*sin); + return sin_addr_len; } EXPORT_SYMBOL(inet6_getname); diff --git a/net/ipv6/ping.c b/net/ipv6/ping.c index e8fb0d275cc2..d2098dd4ceae 100644 --- a/net/ipv6/ping.c +++ b/net/ipv6/ping.c @@ -56,7 +56,7 @@ static int ping_v6_pre_connect(struct sock *sk, struct sockaddr *uaddr, if (addr_len < SIN6_LEN_RFC2133) return -EINVAL; - return BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr); + return BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr, &addr_len); } static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 94afb8d0f2d0..3a1e76a2d33e 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -135,7 +135,7 @@ static int tcp_v6_pre_connect(struct sock *sk, struct sockaddr *uaddr, sock_owned_by_me(sk); - return BPF_CGROUP_RUN_PROG_INET6_CONNECT(sk, uaddr); + return BPF_CGROUP_RUN_PROG_INET6_CONNECT(sk, uaddr, &addr_len); } static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr, diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 5e9312eefed0..622b10a549f7 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -410,7 +410,8 @@ try_again: *addr_len = sizeof(*sin6); BPF_CGROUP_RUN_PROG_UDP6_RECVMSG_LOCK(sk, - (struct sockaddr *)sin6); + (struct sockaddr *)sin6, + addr_len); } if (udp_test_bit(GRO_ENABLED, sk)) @@ -1157,7 +1158,7 @@ static int udpv6_pre_connect(struct sock *sk, struct sockaddr *uaddr, if (addr_len < SIN6_LEN_RFC2133) return -EINVAL; - return BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr); + return BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr, &addr_len); } /** @@ -1510,6 +1511,7 @@ do_udp_sendmsg: if (cgroup_bpf_enabled(CGROUP_UDP6_SENDMSG) && !connected) { err = BPF_CGROUP_RUN_PROG_UDP6_SENDMSG_LOCK(sk, (struct sockaddr *)sin6, + &addr_len, &fl6->saddr); if (err) goto out_no_dst; -- cgit v1.2.3