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/ipv4/af_inet.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'net/ipv4/af_inet.c') diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 3d2e30e20473..7e27ad37b939 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -452,7 +452,7 @@ int inet_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_INET4_BIND, &flags); if (err) return err; @@ -788,6 +788,7 @@ int inet_getname(struct socket *sock, struct sockaddr *uaddr, struct sock *sk = sock->sk; struct inet_sock *inet = inet_sk(sk); DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr); + int sin_addr_len = sizeof(*sin); sin->sin_family = AF_INET; lock_sock(sk); @@ -800,7 +801,7 @@ int inet_getname(struct socket *sock, struct sockaddr *uaddr, } sin->sin_port = inet->inet_dport; sin->sin_addr.s_addr = inet->inet_daddr; - BPF_CGROUP_RUN_SA_PROG(sk, (struct sockaddr *)sin, + BPF_CGROUP_RUN_SA_PROG(sk, (struct sockaddr *)sin, &sin_addr_len, CGROUP_INET4_GETPEERNAME); } else { __be32 addr = inet->inet_rcv_saddr; @@ -808,7 +809,7 @@ int inet_getname(struct socket *sock, struct sockaddr *uaddr, addr = inet->inet_saddr; sin->sin_port = inet->inet_sport; sin->sin_addr.s_addr = addr; - BPF_CGROUP_RUN_SA_PROG(sk, (struct sockaddr *)sin, + BPF_CGROUP_RUN_SA_PROG(sk, (struct sockaddr *)sin, &sin_addr_len, CGROUP_INET4_GETSOCKNAME); } release_sock(sk); -- cgit v1.2.3 From 9c1292eca243821249fa99f40175b0660d9329e3 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Fri, 13 Oct 2023 11:57:02 -0700 Subject: net/bpf: Avoid unused "sin_addr_len" warning when CONFIG_CGROUP_BPF is not set It was reported that there is a compiler warning on the unused variable "sin_addr_len" in af_inet.c when CONFIG_CGROUP_BPF is not set. This patch is to address it similar to the ipv6 counterpart in inet6_getname(). It is to "return sin_addr_len;" instead of "return sizeof(*sin);". Fixes: fefba7d1ae19 ("bpf: Propagate modified uaddrlen from cgroup sockaddr programs") Reported-by: Stephen Rothwell Signed-off-by: Martin KaFai Lau Signed-off-by: Andrii Nakryiko Reviewed-by: Kuniyuki Iwashima Link: https://lore.kernel.org/bpf/20231013185702.3993710-1-martin.lau@linux.dev Closes: https://lore.kernel.org/bpf/20231013114007.2fb09691@canb.auug.org.au/ --- net/ipv4/af_inet.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/ipv4/af_inet.c') diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 7e27ad37b939..5ce275b2d7ef 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -814,7 +814,7 @@ int inet_getname(struct socket *sock, struct sockaddr *uaddr, } release_sock(sk); memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); - return sizeof(*sin); + return sin_addr_len; } EXPORT_SYMBOL(inet_getname); -- cgit v1.2.3