diff options
Diffstat (limited to 'net/can/gw.c')
| -rw-r--r-- | net/can/gw.c | 42 |
1 files changed, 24 insertions, 18 deletions
diff --git a/net/can/gw.c b/net/can/gw.c index 55eccb1c7620..61a1e6b1b83f 100644 --- a/net/can/gw.c +++ b/net/can/gw.c @@ -55,6 +55,7 @@ #include <linux/can/core.h> #include <linux/can/skb.h> #include <linux/can/gw.h> +#include <net/can.h> #include <net/rtnetlink.h> #include <net/net_namespace.h> #include <net/sock.h> @@ -70,8 +71,8 @@ MODULE_ALIAS(CAN_GW_NAME); #define CGW_MAX_HOPS 6 #define CGW_DEFAULT_HOPS 1 -static unsigned int max_hops __read_mostly = CGW_DEFAULT_HOPS; -module_param(max_hops, uint, 0444); +static unsigned char max_hops __read_mostly = CGW_DEFAULT_HOPS; +module_param(max_hops, byte, 0444); MODULE_PARM_DESC(max_hops, "maximum " CAN_GW_NAME " routing hops for CAN frames " "(valid values: " __stringify(CGW_MIN_HOPS) "-" @@ -459,6 +460,7 @@ static void can_can_gw_rcv(struct sk_buff *skb, void *data) struct cgw_job *gwj = (struct cgw_job *)data; struct canfd_frame *cf; struct sk_buff *nskb; + struct can_skb_ext *csx, *ncsx; struct cf_mod *mod; int modidx = 0; @@ -471,22 +473,15 @@ static void can_can_gw_rcv(struct sk_buff *skb, void *data) return; } + csx = can_skb_ext_find(skb); + if (!csx) + return; + /* Do not handle CAN frames routed more than 'max_hops' times. * In general we should never catch this delimiter which is intended * to cover a misconfiguration protection (e.g. circular CAN routes). - * - * The Controller Area Network controllers only accept CAN frames with - * correct CRCs - which are not visible in the controller registers. - * According to skbuff.h documentation the csum_start element for IP - * checksums is undefined/unused when ip_summed == CHECKSUM_UNNECESSARY. - * Only CAN skbs can be processed here which already have this property. */ - -#define cgw_hops(skb) ((skb)->csum_start) - - BUG_ON(skb->ip_summed != CHECKSUM_UNNECESSARY); - - if (cgw_hops(skb) >= max_hops) { + if (csx->can_gw_hops >= max_hops) { /* indicate deleted frames due to misconfiguration */ gwj->deleted_frames++; return; @@ -499,7 +494,7 @@ static void can_can_gw_rcv(struct sk_buff *skb, void *data) /* is sending the skb back to the incoming interface not allowed? */ if (!(gwj->flags & CGW_FLAGS_CAN_IIF_TX_OK) && - can_skb_prv(skb)->ifindex == gwj->dst.dev->ifindex) + csx->can_iif == gwj->dst.dev->ifindex) return; /* clone the given skb, which has not been done in can_rcv() @@ -518,12 +513,23 @@ static void can_can_gw_rcv(struct sk_buff *skb, void *data) return; } + /* the cloned/copied nskb points to the skb extension of the original + * skb with an increased refcount. skb_ext_add() creates a copy to + * separate the skb extension data to modify the can_gw_hops. + */ + ncsx = skb_ext_add(nskb, SKB_EXT_CAN); + if (!ncsx) { + kfree_skb(nskb); + gwj->dropped_frames++; + return; + } + /* put the incremented hop counter in the cloned skb */ - cgw_hops(nskb) = cgw_hops(skb) + 1; + ncsx->can_gw_hops = csx->can_gw_hops + 1; /* first processing of this CAN frame -> adjust to private hop limit */ - if (gwj->limit_hops && cgw_hops(nskb) == 1) - cgw_hops(nskb) = max_hops - gwj->limit_hops + 1; + if (gwj->limit_hops && ncsx->can_gw_hops == 1) + ncsx->can_gw_hops = max_hops - gwj->limit_hops + 1; nskb->dev = gwj->dst.dev; |