A vehicle network system comprising: a plurality of electronic control units that communicate over one or more buses; and a gateway device connected to the one or more buses used in communication by the plurality of electronic control units (100a to 100e), the gateway device comprising: a receiving unit that is configured to receive a first frame; a transmitting unit that is configured to include, when the first frame is received by the receiving unit, in a second frame including information based on content of the first frame, first control information related to a restriction on processing after reception of the second frame, and to transmit the second frame to a bus of the one or more buses; and wherein the first frame is received by the receiving unit, the transmitting unit is configured to conduct the transmission by including the first control information into the second frame if a certain condition is satisfied, but to transmit the second frame to the bus without including the first control information if the certain condition is not satisfied, and after transmitting the second frame including the first control information, the transmitting unit is further configured to transmit to the bus a third frame including second control information related to a processing method of the second frame and wherein the certain condition is a condition that is satisfied in a situation in which the first frame is decided to be appropriate or not after transmission of the second frame, and the transmitting unit is further configured to include, in the third frame, the second control information according to the decision regarding the first frame, wherein the gateway device is configured to cause an electronic control unit among the plurality of electronic control units to determine whether or not the first frame is appropriate. a plurality of electronic control units that communicate over one or more buses; and a gateway device connected to the one or more buses used in communication by the plurality of electronic control units (100a to 100e), the gateway device comprising: a receiving unit that is configured to receive a first frame; a transmitting unit that is configured to include, when the first frame is received by the receiving unit, in a second frame including information based on content of the first frame, first control information related to a restriction on processing after reception of the second frame, and to transmit the second frame to a bus of the one or more buses; and wherein the first frame is received by the receiving unit, the transmitting unit is configured to conduct the transmission by including the first control information into the second frame if a certain condition is satisfied, but to transmit the second frame to the bus without including the first control information if the certain condition is not satisfied, and after transmitting the second frame including the first control information, the transmitting unit is further configured to transmit to the bus a third frame including second control information related to a processing method of the second frame and wherein the certain condition is a condition that is satisfied in a situation in which the first frame is decided to be appropriate or not after transmission of the second frame, and the transmitting unit is further configured to include, in the third frame, the second control information according to the decision regarding the first frame, wherein the gateway device is configured to cause an electronic control unit among the plurality of electronic control units to determine whether or not the first frame is appropriate. a receiving unit that is configured to receive a first frame; a transmitting unit that is configured to include, when the first frame is received by the receiving unit, in a second frame including information based on content of the first frame, first control information related to a restriction on processing after reception of the second frame, and to transmit the second frame to a bus of the one or more buses; and wherein the first frame is received by the receiving unit, the transmitting unit is configured to conduct the transmission by including the first control information into the second frame if a certain condition is satisfied, but to transmit the second frame to the bus without including the first control information if the certain condition is not satisfied, and after transmitting the second frame including the first control information, the transmitting unit is further configured to transmit to the bus a third frame including second control information related to a processing method of the second frame and wherein the certain condition is a condition that is satisfied in a situation in which the first frame is decided to be appropriate or not after transmission of the second frame, and the transmitting unit is further configured to include, in the third frame, the second control information according to the decision regarding the first frame, wherein the gateway device is configured to cause an electronic control unit among the plurality of electronic control units to determine whether or not the first frame is appropriate.