bpf: net: Change do_ip_getsockopt() to take the sockptr_t argument

Similar to the earlier patch that changes sk_getsockopt() to
take the sockptr_t argument.  This patch also changes
do_ip_getsockopt() to take the sockptr_t argument such that
a latter patch can make bpf_getsockopt(SOL_IP) to reuse
do_ip_getsockopt().

Note on the change in ip_mc_gsfget().  This function is to
return an array of sockaddr_storage in optval.  This function
is shared between ip_get_mcast_msfilter() and
compat_ip_get_mcast_msfilter().  However, the sockaddr_storage
is stored at different offset of the optval because of
the difference between group_filter and compat_group_filter.
Thus, a new 'ss_offset' argument is added to ip_mc_gsfget().

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20220902002828.2890585-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 45 insertions, 35 deletions

diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 751fa69cb557..5310def20e0c 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -1462,37 +1462,37 @@ static bool getsockopt_needs_rtnl(int optname)
 	return false;
 }
 
-static int ip_get_mcast_msfilter(struct sock *sk, void __user *optval,
-		int __user *optlen, int len)
+static int ip_get_mcast_msfilter(struct sock *sk, sockptr_t optval,
+				 sockptr_t optlen, int len)
 {
 	const int size0 = offsetof(struct group_filter, gf_slist_flex);
-	struct group_filter __user *p = optval;
 	struct group_filter gsf;
-	int num;
+	int num, gsf_size;
 	int err;
 
 	if (len < size0)
 		return -EINVAL;
-	if (copy_from_user(&gsf, p, size0))
+	if (copy_from_sockptr(&gsf, optval, size0))
 		return -EFAULT;
 
 	num = gsf.gf_numsrc;
-	err = ip_mc_gsfget(sk, &gsf, p->gf_slist_flex);
+	err = ip_mc_gsfget(sk, &gsf, optval,
+			   offsetof(struct group_filter, gf_slist_flex));
 	if (err)
 		return err;
 	if (gsf.gf_numsrc < num)
 		num = gsf.gf_numsrc;
-	if (put_user(GROUP_FILTER_SIZE(num), optlen) ||
-	    copy_to_user(p, &gsf, size0))
+	gsf_size = GROUP_FILTER_SIZE(num);
+	if (copy_to_sockptr(optlen, &gsf_size, sizeof(int)) ||
+	    copy_to_sockptr(optval, &gsf, size0))
 		return -EFAULT;
 	return 0;
 }
 
-static int compat_ip_get_mcast_msfilter(struct sock *sk, void __user *optval,
-		int __user *optlen, int len)
+static int compat_ip_get_mcast_msfilter(struct sock *sk, sockptr_t optval,
+					sockptr_t optlen, int len)
 {
 	const int size0 = offsetof(struct compat_group_filter, gf_slist_flex);
-	struct compat_group_filter __user *p = optval;
 	struct compat_group_filter gf32;
 	struct group_filter gf;
 	int num;
@@ -1500,7 +1500,7 @@ static int compat_ip_get_mcast_msfilter(struct sock *sk, void __user *optval,
 
 	if (len < size0)
 		return -EINVAL;
-	if (copy_from_user(&gf32, p, size0))
+	if (copy_from_sockptr(&gf32, optval, size0))
 		return -EFAULT;
 
 	gf.gf_interface = gf32.gf_interface;
@@ -1508,21 +1508,24 @@ static int compat_ip_get_mcast_msfilter(struct sock *sk, void __user *optval,
 	num = gf.gf_numsrc = gf32.gf_numsrc;
 	gf.gf_group = gf32.gf_group;
 
-	err = ip_mc_gsfget(sk, &gf, p->gf_slist_flex);
+	err = ip_mc_gsfget(sk, &gf, optval,
+			   offsetof(struct compat_group_filter, gf_slist_flex));
 	if (err)
 		return err;
 	if (gf.gf_numsrc < num)
 		num = gf.gf_numsrc;
 	len = GROUP_FILTER_SIZE(num) - (sizeof(gf) - sizeof(gf32));
-	if (put_user(len, optlen) ||
-	    put_user(gf.gf_fmode, &p->gf_fmode) ||
-	    put_user(gf.gf_numsrc, &p->gf_numsrc))
+	if (copy_to_sockptr(optlen, &len, sizeof(int)) ||
+	    copy_to_sockptr_offset(optval, offsetof(struct compat_group_filter, gf_fmode),
+				   &gf.gf_fmode, sizeof(gf.gf_fmode)) ||
+	    copy_to_sockptr_offset(optval, offsetof(struct compat_group_filter, gf_numsrc),
+				   &gf.gf_numsrc, sizeof(gf.gf_numsrc)))
 		return -EFAULT;
 	return 0;
 }
 
 static int do_ip_getsockopt(struct sock *sk, int level, int optname,
-			    char __user *optval, int __user *optlen)
+			    sockptr_t optval, sockptr_t optlen)
 {
 	struct inet_sock *inet = inet_sk(sk);
 	bool needs_rtnl = getsockopt_needs_rtnl(optname);
@@ -1535,7 +1538,7 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
 	if (ip_mroute_opt(optname))
 		return ip_mroute_getsockopt(sk, optname, optval, optlen);
 
-	if (get_user(len, optlen))
+	if (copy_from_sockptr(&len, optlen, sizeof(int)))
 		return -EFAULT;
 	if (len < 0)
 		return -EINVAL;
@@ -1560,15 +1563,17 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
 			       inet_opt->opt.optlen);
 		release_sock(sk);
 
-		if (opt->optlen == 0)
-			return put_user(0, optlen);
+		if (opt->optlen == 0) {
+			len = 0;
+			return copy_to_sockptr(optlen, &len, sizeof(int));
+		}
 
 		ip_options_undo(opt);
 
 		len = min_t(unsigned int, len, opt->optlen);
-		if (put_user(len, optlen))
+		if (copy_to_sockptr(optlen, &len, sizeof(int)))
 			return -EFAULT;
-		if (copy_to_user(optval, opt->__data, len))
+		if (copy_to_sockptr(optval, opt->__data, len))
 			return -EFAULT;
 		return 0;
 	}
@@ -1659,9 +1664,9 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
 		addr.s_addr = inet->mc_addr;
 		release_sock(sk);
 
-		if (put_user(len, optlen))
+		if (copy_to_sockptr(optlen, &len, sizeof(int)))
 			return -EFAULT;
-		if (copy_to_user(optval, &addr, len))
+		if (copy_to_sockptr(optval, &addr, len))
 			return -EFAULT;
 		return 0;
 	}
@@ -1673,12 +1678,11 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
 			err = -EINVAL;
 			goto out;
 		}
-		if (copy_from_user(&msf, optval, IP_MSFILTER_SIZE(0))) {
+		if (copy_from_sockptr(&msf, optval, IP_MSFILTER_SIZE(0))) {
 			err = -EFAULT;
 			goto out;
 		}
-		err = ip_mc_msfget(sk, &msf,
-				   (struct ip_msfilter __user *)optval, optlen);
+		err = ip_mc_msfget(sk, &msf, optval, optlen);
 		goto out;
 	}
 	case MCAST_MSFILTER:
@@ -1700,8 +1704,13 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
 		if (sk->sk_type != SOCK_STREAM)
 			return -ENOPROTOOPT;
 
-		msg.msg_control_is_user = true;
-		msg.msg_control_user = optval;
+		if (optval.is_kernel) {
+			msg.msg_control_is_user = false;
+			msg.msg_control = optval.kernel;
+		} else {
+			msg.msg_control_is_user = true;
+			msg.msg_control_user = optval.user;
+		}
 		msg.msg_controllen = len;
 		msg.msg_flags = in_compat_syscall() ? MSG_CMSG_COMPAT : 0;
 
@@ -1722,7 +1731,7 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
 			put_cmsg(&msg, SOL_IP, IP_TOS, sizeof(tos), &tos);
 		}
 		len -= msg.msg_controllen;
-		return put_user(len, optlen);
+		return copy_to_sockptr(optlen, &len, sizeof(int));
 	}
 	case IP_FREEBIND:
 		val = inet->freebind;
@@ -1742,15 +1751,15 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
 	if (len < sizeof(int) && len > 0 && val >= 0 && val <= 255) {
 		unsigned char ucval = (unsigned char)val;
 		len = 1;
-		if (put_user(len, optlen))
+		if (copy_to_sockptr(optlen, &len, sizeof(int)))
 			return -EFAULT;
-		if (copy_to_user(optval, &ucval, 1))
+		if (copy_to_sockptr(optval, &ucval, 1))
 			return -EFAULT;
 	} else {
 		len = min_t(unsigned int, sizeof(int), len);
-		if (put_user(len, optlen))
+		if (copy_to_sockptr(optlen, &len, sizeof(int)))
 			return -EFAULT;
-		if (copy_to_user(optval, &val, len))
+		if (copy_to_sockptr(optval, &val, len))
 			return -EFAULT;
 	}
 	return 0;
@@ -1767,7 +1776,8 @@ int ip_getsockopt(struct sock *sk, int level,
 {
 	int err;
 
-	err = do_ip_getsockopt(sk, level, optname, optval, optlen);
+	err = do_ip_getsockopt(sk, level, optname,
+			       USER_SOCKPTR(optval), USER_SOCKPTR(optlen));
 
 #if IS_ENABLED(CONFIG_BPFILTER_UMH)
 	if (optname >= BPFILTER_IPT_SO_GET_INFO &&