12 files changed, 55 insertions, 0 deletions
diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h
index 0926de63a62b..7b285dd4fe05 100644
--- a/arch/alpha/include/uapi/asm/socket.h
+++ b/arch/alpha/include/uapi/asm/socket.h
@@ -107,4 +107,6 @@
 
 #define SCM_TIMESTAMPING_PKTINFO	58
 
+#define SO_PEERGROUPS		59
+
 #endif /* _UAPI_ASM_SOCKET_H */
diff --git a/arch/frv/include/uapi/asm/socket.h b/arch/frv/include/uapi/asm/socket.h
index e491ff08b9a9..f1e3b20dce9f 100644
--- a/arch/frv/include/uapi/asm/socket.h
+++ b/arch/frv/include/uapi/asm/socket.h
@@ -100,5 +100,7 @@
 
 #define SCM_TIMESTAMPING_PKTINFO	58
 
+#define SO_PEERGROUPS		59
+
 #endif /* _ASM_SOCKET_H */
 
diff --git a/arch/ia64/include/uapi/asm/socket.h b/arch/ia64/include/uapi/asm/socket.h
index 869372413333..5dd5c5d0d642 100644
--- a/arch/ia64/include/uapi/asm/socket.h
+++ b/arch/ia64/include/uapi/asm/socket.h
@@ -109,4 +109,6 @@
 
 #define SCM_TIMESTAMPING_PKTINFO	58
 
+#define SO_PEERGROUPS		59
+
 #endif /* _ASM_IA64_SOCKET_H */
diff --git a/arch/m32r/include/uapi/asm/socket.h b/arch/m32r/include/uapi/asm/socket.h
index 5d97890a8704..f8f7b47e247f 100644
--- a/arch/m32r/include/uapi/asm/socket.h
+++ b/arch/m32r/include/uapi/asm/socket.h
@@ -100,4 +100,6 @@
 
 #define SCM_TIMESTAMPING_PKTINFO	58
 
+#define SO_PEERGROUPS		59
+
 #endif /* _ASM_M32R_SOCKET_H */
diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h
index 365ff51f033a..882823bec153 100644
--- a/arch/mips/include/uapi/asm/socket.h
+++ b/arch/mips/include/uapi/asm/socket.h
@@ -118,4 +118,6 @@
 
 #define SCM_TIMESTAMPING_PKTINFO	58
 
+#define SO_PEERGROUPS		59
+
 #endif /* _UAPI_ASM_SOCKET_H */
diff --git a/arch/mn10300/include/uapi/asm/socket.h b/arch/mn10300/include/uapi/asm/socket.h
index d013c0da0256..c710db354ff2 100644
--- a/arch/mn10300/include/uapi/asm/socket.h
+++ b/arch/mn10300/include/uapi/asm/socket.h
@@ -100,4 +100,6 @@
 
 #define SCM_TIMESTAMPING_PKTINFO	58
 
+#define SO_PEERGROUPS		59
+
 #endif /* _ASM_SOCKET_H */
diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h
index b893ca14fade..a0d4dc9f4eb2 100644
--- a/arch/parisc/include/uapi/asm/socket.h
+++ b/arch/parisc/include/uapi/asm/socket.h
@@ -99,4 +99,6 @@
 
 #define SCM_TIMESTAMPING_PKTINFO	0x4033
 
+#define SO_PEERGROUPS		0x4034
+
 #endif /* _UAPI_ASM_SOCKET_H */
diff --git a/arch/s390/include/uapi/asm/socket.h b/arch/s390/include/uapi/asm/socket.h
index fb9769d7e74e..52a63f4175cb 100644
--- a/arch/s390/include/uapi/asm/socket.h
+++ b/arch/s390/include/uapi/asm/socket.h
@@ -106,4 +106,6 @@
 
 #define SCM_TIMESTAMPING_PKTINFO	58
 
+#define SO_PEERGROUPS		59
+
 #endif /* _ASM_SOCKET_H */
diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h
index 5d673302fd41..186fd8199f54 100644
--- a/arch/sparc/include/uapi/asm/socket.h
+++ b/arch/sparc/include/uapi/asm/socket.h
@@ -96,6 +96,8 @@
 
 #define SCM_TIMESTAMPING_PKTINFO	0x003c
 
+#define SO_PEERGROUPS		0x003d
+
 /* Security levels - as per NRL IPv6 - don't actually do anything */
 #define SO_SECURITY_AUTHENTICATION		0x5001
 #define SO_SECURITY_ENCRYPTION_TRANSPORT	0x5002
diff --git a/arch/xtensa/include/uapi/asm/socket.h b/arch/xtensa/include/uapi/asm/socket.h
index 982c2533f912..3eed2761c149 100644
--- a/arch/xtensa/include/uapi/asm/socket.h
+++ b/arch/xtensa/include/uapi/asm/socket.h
@@ -111,4 +111,6 @@
 
 #define SCM_TIMESTAMPING_PKTINFO	58
 
+#define SO_PEERGROUPS		59
+
 #endif	/* _XTENSA_SOCKET_H */
diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h
index a5f6e819fafd..9861be8da65e 100644
--- a/include/uapi/asm-generic/socket.h
+++ b/include/uapi/asm-generic/socket.h
@@ -102,4 +102,6 @@
 
 #define SCM_TIMESTAMPING_PKTINFO	58
 
+#define SO_PEERGROUPS		59
+
 #endif /* __ASM_GENERIC_SOCKET_H */
diff --git a/net/core/sock.c b/net/core/sock.c
index ad8a4bc84126..6f4b090241c1 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1078,6 +1078,18 @@ static void cred_to_ucred(struct pid *pid, const struct cred *cred,
 	}
 }
 
+static int groups_to_user(gid_t __user *dst, const struct group_info *src)
+{
+	struct user_namespace *user_ns = current_user_ns();
+	int i;
+
+	for (i = 0; i < src->ngroups; i++)
+		if (put_user(from_kgid_munged(user_ns, src->gid[i]), dst + i))
+			return -EFAULT;
+
+	return 0;
+}
+
 int sock_getsockopt(struct socket *sock, int level, int optname,
 		    char __user *optval, int __user *optlen)
 {
@@ -1231,6 +1243,27 @@ int sock_getsockopt(struct socket *sock, int level, int optname,
 		goto lenout;
 	}
 
+	case SO_PEERGROUPS:
+	{
+		int ret, n;
+
+		if (!sk->sk_peer_cred)
+			return -ENODATA;
+
+		n = sk->sk_peer_cred->group_info->ngroups;
+		if (len < n * sizeof(gid_t)) {
+			len = n * sizeof(gid_t);
+			return put_user(len, optlen) ? -EFAULT : -ERANGE;
+		}
+		len = n * sizeof(gid_t);
+
+		ret = groups_to_user((gid_t __user *)optval,
+				     sk->sk_peer_cred->group_info);
+		if (ret)
+			return ret;
+		goto lenout;
+	}
+
 	case SO_PEERNAME:
 	{
 		char address[128];