bpf: Change bpf_getsockopt(SOL_IPV6) to reuse do_ipv6_getsockopt()

This patch changes bpf_getsockopt(SOL_IPV6) to reuse
do_ipv6_getsockopt().  It removes the duplicated code from
bpf_getsockopt(SOL_IPV6).

This also makes bpf_getsockopt(SOL_IPV6) supporting the same
set of optnames as in bpf_setsockopt(SOL_IPV6).  In particular,
this adds IPV6_AUTOFLOWLABEL support to bpf_getsockopt(SOL_IPV6).

ipv6 could be compiled as a module.  Like how other code solved it
with stubs in ipv6_stubs.h, this patch adds the do_ipv6_getsockopt
to the ipv6_bpf_stub.

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20220902002931.2896218-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index a4f2457..d664ba5 100644 (file)
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -1160,6 +1160,8 @@ int do_ipv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval
                       unsigned int optlen);
 int ipv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
                    unsigned int optlen);
+int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
+                      sockptr_t optval, sockptr_t optlen);
 int ipv6_getsockopt(struct sock *sk, int level, int optname,
                    char __user *optval, int __user *optlen);
 

diff --git a/include/net/ipv6_stubs.h b/include/net/ipv6_stubs.h
index 8692698..c48186b 100644 (file)
--- a/include/net/ipv6_stubs.h
+++ b/include/net/ipv6_stubs.h
@@ -83,6 +83,8 @@ struct ipv6_bpf_stub {
                                     struct sk_buff *skb);
        int (*ipv6_setsockopt)(struct sock *sk, int level, int optname,
                               sockptr_t optval, unsigned int optlen);
+       int (*ipv6_getsockopt)(struct sock *sk, int level, int optname,
+                              sockptr_t optval, sockptr_t optlen);
 };
 extern const struct ipv6_bpf_stub *ipv6_bpf_stub __read_mostly;
 

diff --git a/net/core/filter.c b/net/core/filter.c
index 3327546..ee768bb 100644 (file)
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -5191,8 +5191,9 @@ static int sol_ip_sockopt(struct sock *sk, int optname,
                                KERNEL_SOCKPTR(optval), *optlen);
 }
 
-static int sol_ipv6_setsockopt(struct sock *sk, int optname,
-                              char *optval, int optlen)
+static int sol_ipv6_sockopt(struct sock *sk, int optname,
+                           char *optval, int *optlen,
+                           bool getopt)
 {
        if (sk->sk_family != AF_INET6)
                return -EINVAL;
@@ -5200,15 +5201,20 @@ static int sol_ipv6_setsockopt(struct sock *sk, int optname,
        switch (optname) {
        case IPV6_TCLASS:
        case IPV6_AUTOFLOWLABEL:
-               if (optlen != sizeof(int))
+               if (*optlen != sizeof(int))
                        return -EINVAL;
                break;
        default:
                return -EINVAL;
        }
 
+       if (getopt)
+               return ipv6_bpf_stub->ipv6_getsockopt(sk, SOL_IPV6, optname,
+                                                     KERNEL_SOCKPTR(optval),
+                                                     KERNEL_SOCKPTR(optlen));
+
        return ipv6_bpf_stub->ipv6_setsockopt(sk, SOL_IPV6, optname,
-                                             KERNEL_SOCKPTR(optval), optlen);
+                                             KERNEL_SOCKPTR(optval), *optlen);
 }
 
 static int __bpf_setsockopt(struct sock *sk, int level, int optname,
@@ -5222,7 +5228,7 @@ static int __bpf_setsockopt(struct sock *sk, int level, int optname,
        else if (IS_ENABLED(CONFIG_INET) && level == SOL_IP)
                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);
+               return sol_ipv6_sockopt(sk, optname, optval, &optlen, false);
        else if (IS_ENABLED(CONFIG_INET) && level == SOL_TCP)
                return sol_tcp_sockopt(sk, optname, optval, &optlen, false);
 
@@ -5240,43 +5246,30 @@ static int _bpf_setsockopt(struct sock *sk, int level, int optname,
 static int __bpf_getsockopt(struct sock *sk, int level, int optname,
                            char *optval, int optlen)
 {
-       int err = 0, saved_optlen = optlen;
+       int err, saved_optlen = optlen;
 
-       if (!sk_fullsock(sk))
-               goto err_clear;
+       if (!sk_fullsock(sk)) {
+               err = -EINVAL;
+               goto done;
+       }
 
-       if (level == SOL_SOCKET) {
+       if (level == SOL_SOCKET)
                err = sol_socket_sockopt(sk, optname, optval, &optlen, true);
-       } else if (IS_ENABLED(CONFIG_INET) && level == SOL_TCP) {
+       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) {
+       else if (IS_ENABLED(CONFIG_INET) && level == SOL_IP)
                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);
-
-               if (optlen != sizeof(int) || sk->sk_family != AF_INET6)
-                       goto err_clear;
-
-               /* Only some options are supported */
-               switch (optname) {
-               case IPV6_TCLASS:
-                       *((int *)optval) = (int)np->tclass;
-                       break;
-               default:
-                       goto err_clear;
-               }
-       } else {
-               goto err_clear;
-       }
+       else if (IS_ENABLED(CONFIG_IPV6) && level == SOL_IPV6)
+               err = sol_ipv6_sockopt(sk, optname, optval, &optlen, true);
+       else
+               err = -EINVAL;
 
+done:
        if (err)
                optlen = 0;
        if (optlen < saved_optlen)
                memset(optval + optlen, 0, saved_optlen - optlen);
        return err;
-err_clear:
-       memset(optval, 0, optlen);
-       return -EINVAL;
 }
 
 static int _bpf_getsockopt(struct sock *sk, int level, int optname,

diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index cadc978..19732b5 100644 (file)
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -1058,6 +1058,7 @@ static const struct ipv6_bpf_stub ipv6_bpf_stub_impl = {
        .inet6_bind = __inet6_bind,
        .udp6_lib_lookup = __udp6_lib_lookup,
        .ipv6_setsockopt = do_ipv6_setsockopt,
+       .ipv6_getsockopt = do_ipv6_getsockopt,
 };
 
 static int __init inet6_init(void)

diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index d9887e3..1193f5a 100644 (file)
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -1131,8 +1131,8 @@ static int compat_ipv6_get_msfilter(struct sock *sk, sockptr_t optval,
        return 0;
 }
 
-static int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
-                             sockptr_t optval, sockptr_t optlen)
+int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
+                      sockptr_t optval, sockptr_t optlen)
 {
        struct ipv6_pinfo *np = inet6_sk(sk);
        int len;