[PATCH v2 bpf-next 15/17] bpf: Change bpf_getsockopt(SOL_IP) to reuse do_ip_getsockopt()

Martin KaFai Lau
2022-09-02T00:32:05Z

This patch changes bpf_getsockopt(SOL_IP) to reuse
do_ip_getsockopt() and remove the duplicated code.

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
---
include/net/ip.h | 2 ++
net/core/filter.c | 30 ++++++++++++------------------
net/ipv4/ip_sockglue.c | 4 ++--
3 files changed, 16 insertions(+), 20 deletions(-)

diff --git a/include/net/ip.h b/include/net/ip.h
index 34fa5b0f0a0e..038097c2a152 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -747,6 +747,8 @@ int do_ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
unsigned int optlen);
int ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
unsigned int optlen);
+int do_ip_getsockopt(struct sock *sk, int level, int optname,
+ sockptr_t optval, sockptr_t optlen);
int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
int __user *optlen);
int ip_ra_control(struct sock *sk, unsigned char on,
diff --git a/net/core/filter.c b/net/core/filter.c
index e427f40f0cee..a9d88fd0541e 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -5162,23 +5162,29 @@ static int sol_tcp_sockopt(struct sock *sk, int optname,
KERNEL_SOCKPTR(optval), *optlen);
}

-static int sol_ip_setsockopt(struct sock *sk, int optname,
- char *optval, int optlen)
+static int sol_ip_sockopt(struct sock *sk, int optname,
+ char *optval, int *optlen,
+ bool getopt)
{
if (sk->sk_family != AF_INET)
return -EINVAL;

switch (optname) {
case IP_TOS:
- if (optlen != sizeof(int))
+ if (*optlen != sizeof(int))
return -EINVAL;
break;
default:
return -EINVAL;
}

+ if (getopt)
+ return do_ip_getsockopt(sk, SOL_IP, optname,
+ KERNEL_SOCKPTR(optval),
+ KERNEL_SOCKPTR(optlen));
+
return do_ip_setsockopt(sk, SOL_IP, optname,
- KERNEL_SOCKPTR(optval), optlen);
+ KERNEL_SOCKPTR(optval), *optlen);
}

static int sol_ipv6_setsockopt(struct sock *sk, int optname,
@@ -5210,7 +5216,7 @@ static int __bpf_setsockopt(struct sock *sk, int level, int optname,
if (level == SOL_SOCKET)
return sol_socket_sockopt(sk, optname, optval, &optlen, false);
else if (IS_ENABLED(CONFIG_INET) && level == SOL_IP)
- return sol_ip_setsockopt(sk, optname, optval, optlen);
+ return sol_ip_sockopt(sk, optname, optval, &optlen, false);
else if (IS_ENABLED(CONFIG_IPV6) && level == SOL_IPV6)
return sol_ipv6_setsockopt(sk, optname, optval, optlen);
else if (IS_ENABLED(CONFIG_INET) && level == SOL_TCP)
@@ -5240,19 +5246,7 @@ static int __bpf_getsockopt(struct sock *sk, int level, int optname,
} else if (IS_ENABLED(CONFIG_INET) && level == SOL_TCP) {
err = sol_tcp_sockopt(sk, optname, optval, &optlen, true);
} else if (IS_ENABLED(CONFIG_INET) && level == SOL_IP) {
- struct inet_sock *inet = inet_sk(sk);
-
- if (optlen != sizeof(int) || sk->sk_family != AF_INET)
- goto err_clear;
-
- /* Only some options are supported */
- switch (optname) {
- case IP_TOS:
- *((int *)optval) = (int)inet->tos;
- break;
- default:
- goto err_clear;
- }
+ err = sol_ip_sockopt(sk, optname, optval, &optlen, true);
} else if (IS_ENABLED(CONFIG_IPV6) && level == SOL_IPV6) {
struct ipv6_pinfo *np = inet6_sk(sk);

diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 5d134a75cad0..47830f3fea1b 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -1524,8 +1524,8 @@ static int compat_ip_get_mcast_msfilter(struct sock *sk, sockptr_t optval,
return 0;
}

-static int do_ip_getsockopt(struct sock *sk, int level, int optname,
- sockptr_t optval, sockptr_t optlen)
+int do_ip_getsockopt(struct sock *sk, int level, int optname,
+ sockptr_t optval, sockptr_t optlen)
{
struct inet_sock *inet = inet_sk(sk);
bool needs_rtnl = getsockopt_needs_rtnl(optname);
--
2.30.2