From 9868b5d44f3df9dd75247acd23dddff0a42f79be Mon Sep 17 00:00:00 2001 From: Kurt Van Dijck Date: Mon, 8 Oct 2018 11:48:33 +0200 Subject: [PATCH] can: introduce CAN_REQUIRED_SIZE macro The size of this structure will be increased with J1939 support. To stay binary compatible, the CAN_REQUIRED_SIZE macro is introduced for existing CAN protocols. Signed-off-by: Kurt Van Dijck Signed-off-by: Oleksij Rempel Acked-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde --- include/linux/can/core.h | 8 ++++++++ net/can/bcm.c | 4 ++-- net/can/raw.c | 4 ++-- 3 files changed, 12 insertions(+), 4 deletions(-) diff --git a/include/linux/can/core.h b/include/linux/can/core.h index 708c10d3417a9e..8339071ab08b65 100644 --- a/include/linux/can/core.h +++ b/include/linux/can/core.h @@ -41,6 +41,14 @@ struct can_proto { struct proto *prot; }; +/* required_size + * macro to find the minimum size of a struct + * that includes a requested member + */ +#define CAN_REQUIRED_SIZE(struct_type, member) \ + (offsetof(typeof(struct_type), member) + \ + sizeof(((typeof(struct_type) *)(NULL))->member)) + /* function prototypes for the CAN networklayer core (af_can.c) */ extern int can_proto_register(const struct can_proto *cp); diff --git a/net/can/bcm.c b/net/can/bcm.c index 28fd1a1c84875d..c96fa0f33db39c 100644 --- a/net/can/bcm.c +++ b/net/can/bcm.c @@ -1294,7 +1294,7 @@ static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) /* no bound device as default => check msg_name */ DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name); - if (msg->msg_namelen < sizeof(*addr)) + if (msg->msg_namelen < CAN_REQUIRED_SIZE(*addr, can_ifindex)) return -EINVAL; if (addr->can_family != AF_CAN) @@ -1536,7 +1536,7 @@ static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len, struct net *net = sock_net(sk); int ret = 0; - if (len < sizeof(*addr)) + if (len < CAN_REQUIRED_SIZE(*addr, can_ifindex)) return -EINVAL; lock_sock(sk); diff --git a/net/can/raw.c b/net/can/raw.c index fdbc36140e9bc1..59c039d73c6d58 100644 --- a/net/can/raw.c +++ b/net/can/raw.c @@ -396,7 +396,7 @@ static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len) int err = 0; int notify_enetdown = 0; - if (len < sizeof(*addr)) + if (len < CAN_REQUIRED_SIZE(*addr, can_ifindex)) return -EINVAL; if (addr->can_family != AF_CAN) return -EINVAL; @@ -733,7 +733,7 @@ static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) if (msg->msg_name) { DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name); - if (msg->msg_namelen < sizeof(*addr)) + if (msg->msg_namelen < CAN_REQUIRED_SIZE(*addr, can_ifindex)) return -EINVAL; if (addr->can_family != AF_CAN)