handshake: Fix sign of socket file descriptor fields

Socket file descriptors are signed integers. Use nla_get/put_s32 for
those to avoid implicit signed conversion in the netlink protocol.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/169530165057.8905.8650469415145814828.stgit@oracle-102.nfsv4bat.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Documentation/netlink/specs/handshake.yaml

@@ -43,7 +43,7 @@ attribute-sets:
     attributes:
       -
         name: sockfd
-        type: u32
+        type: s32
       -
         name: handler-class
         type: u32
@@ -79,7 +79,7 @@ attribute-sets:
         type: u32
       -
         name: sockfd
-        type: u32
+        type: s32
       -
         name: remote-auth
         type: u32

net/handshake/genl.c

@@ -18,7 +18,7 @@ static const struct nla_policy handshake_accept_nl_policy[HANDSHAKE_A_ACCEPT_HAN
 /* HANDSHAKE_CMD_DONE - do */
 static const struct nla_policy handshake_done_nl_policy[HANDSHAKE_A_DONE_REMOTE_AUTH + 1] = {
 	[HANDSHAKE_A_DONE_STATUS] = { .type = NLA_U32, },
-	[HANDSHAKE_A_DONE_SOCKFD] = { .type = NLA_U32, },
+	[HANDSHAKE_A_DONE_SOCKFD] = { .type = NLA_S32, },
 	[HANDSHAKE_A_DONE_REMOTE_AUTH] = { .type = NLA_U32, },
 };
 

net/handshake/netlink.c

@@ -163,7 +163,7 @@ int handshake_nl_done_doit(struct sk_buff *skb, struct genl_info *info)
 
 	if (GENL_REQ_ATTR_CHECK(info, HANDSHAKE_A_DONE_SOCKFD))
 		return -EINVAL;
-	fd = nla_get_u32(info->attrs[HANDSHAKE_A_DONE_SOCKFD]);
+	fd = nla_get_s32(info->attrs[HANDSHAKE_A_DONE_SOCKFD]);
 
 	sock = sockfd_lookup(fd, &err);
 	if (!sock)

net/handshake/tlshd.c

@@ -214,7 +214,7 @@ static int tls_handshake_accept(struct handshake_req *req,
 		goto out_cancel;
 
 	ret = -EMSGSIZE;
-	ret = nla_put_u32(msg, HANDSHAKE_A_ACCEPT_SOCKFD, fd);
+	ret = nla_put_s32(msg, HANDSHAKE_A_ACCEPT_SOCKFD, fd);
 	if (ret < 0)
 		goto out_cancel;
 	ret = nla_put_u32(msg, HANDSHAKE_A_ACCEPT_MESSAGE_TYPE, treq->th_type);

tools/net/ynl/generated/handshake-user.h

@@ -65,7 +65,7 @@ struct handshake_accept_rsp {
 		__u32 peername_len;
 	} _present;
 
-	__u32 sockfd;
+	__s32 sockfd;
 	enum handshake_msg_type message_type;
 	__u32 timeout;
 	enum handshake_auth auth_mode;
@@ -104,7 +104,7 @@ struct handshake_done_req {
 	} _present;
 
 	__u32 status;
-	__u32 sockfd;
+	__s32 sockfd;
 	unsigned int n_remote_auth;
 	__u32 *remote_auth;
 };
@@ -122,7 +122,7 @@ handshake_done_req_set_status(struct handshake_done_req *req, __u32 status)
 	req->status = status;
 }
 static inline void
-handshake_done_req_set_sockfd(struct handshake_done_req *req, __u32 sockfd)
+handshake_done_req_set_sockfd(struct handshake_done_req *req, __s32 sockfd)
 {
 	req->_present.sockfd = 1;
 	req->sockfd = sockfd;