1 files changed, 56 insertions, 12 deletions

diff --git a/net/can/gw.c b/net/can/gw.c
index a6f448e18ea8..455168718c2e 100644
--- a/net/can/gw.c
+++ b/net/can/gw.c
@@ -110,6 +110,7 @@ struct cf_mod {
                 void (*xor)(struct can_frame *cf, struct cgw_csum_xor *xor);
                 void (*crc8)(struct can_frame *cf, struct cgw_csum_crc8 *crc8);
         } csumfunc;
+        u32 uid;
 };
 
 
@@ -548,6 +549,11 @@ static int cgw_put_job(struct sk_buff *skb, struct cgw_job *gwj, int type,
                         goto cancel;
         }
 
+        if (gwj->mod.uid) {
+                if (nla_put_u32(skb, CGW_MOD_UID, gwj->mod.uid) < 0)
+                        goto cancel;
+        }
+
         if (gwj->mod.csumfunc.crc8) {
                 if (nla_put(skb, CGW_CS_CRC8, CGW_CS_CRC8_LEN,
                             &gwj->mod.csum.crc8) < 0)
@@ -619,6 +625,7 @@ static const struct nla_policy cgw_policy[CGW_MAX+1] = {
         [CGW_DST_IF]    = { .type = NLA_U32 },
         [CGW_FILTER]    = { .len = sizeof(struct can_filter) },
         [CGW_LIM_HOPS]  = { .type = NLA_U8 },
+        [CGW_MOD_UID]   = { .type = NLA_U32 },
 };
 
 /* check for common and gwtype specific attributes */
@@ -761,6 +768,10 @@ static int cgw_parse_attr(struct nlmsghdr *nlh, struct cf_mod *mod,
                         else
                                 mod->csumfunc.xor = cgw_csum_xor_neg;
                 }
+
+                if (tb[CGW_MOD_UID]) {
+                        nla_memcpy(&mod->uid, tb[CGW_MOD_UID], sizeof(u32));
+                }
         }
 
         if (gwtype == CGW_TYPE_CAN_CAN) {
@@ -802,6 +813,8 @@ static int cgw_create_job(struct sk_buff *skb,  struct nlmsghdr *nlh)
 {
         struct rtcanmsg *r;
         struct cgw_job *gwj;
+        struct cf_mod mod;
+        struct can_can_gw ccgw;
         u8 limhops = 0;
         int err = 0;
 
@@ -819,6 +832,36 @@ static int cgw_create_job(struct sk_buff *skb,  struct nlmsghdr *nlh)
         if (r->gwtype != CGW_TYPE_CAN_CAN)
                 return -EINVAL;
 
+        err = cgw_parse_attr(nlh, &mod, CGW_TYPE_CAN_CAN, &ccgw, &limhops);
+        if (err < 0)
+                return err;
+
+        if (mod.uid) {
+
+                ASSERT_RTNL();
+
+                /* check for updating an existing job with identical uid */
+                hlist_for_each_entry(gwj, &cgw_list, list) {
+
+                        if (gwj->mod.uid != mod.uid)
+                                continue;
+
+                        /* interfaces & filters must be identical */
+                        if (memcmp(&gwj->ccgw, &ccgw, sizeof(ccgw)))
+                                return -EINVAL;
+
+                        /* update modifications with disabled softirq & quit */
+                        local_bh_disable();
+                        memcpy(&gwj->mod, &mod, sizeof(mod));
+                        local_bh_enable();
+                        return 0;
+                }
+        }
+
+        /* ifindex == 0 is not allowed for job creation */
+        if (!ccgw.src_idx || !ccgw.dst_idx)
+                return -ENODEV;
+
         gwj = kmem_cache_alloc(cgw_cache, GFP_KERNEL);
         if (!gwj)
                 return -ENOMEM;
@@ -828,18 +871,14 @@ static int cgw_create_job(struct sk_buff *skb,  struct nlmsghdr *nlh)
         gwj->deleted_frames = 0;
         gwj->flags = r->flags;
         gwj->gwtype = r->gwtype;
+        gwj->limit_hops = limhops;
 
-        err = cgw_parse_attr(nlh, &gwj->mod, CGW_TYPE_CAN_CAN, &gwj->ccgw,
-                             &limhops);
-        if (err < 0)
-                goto out;
+        /* insert already parsed information */
+        memcpy(&gwj->mod, &mod, sizeof(mod));
+        memcpy(&gwj->ccgw, &ccgw, sizeof(ccgw));
 
         err = -ENODEV;
 
-        /* ifindex == 0 is not allowed for job creation */
-        if (!gwj->ccgw.src_idx || !gwj->ccgw.dst_idx)
-                goto out;
-
         gwj->src.dev = __dev_get_by_index(&init_net, gwj->ccgw.src_idx);
 
         if (!gwj->src.dev)
@@ -856,8 +895,6 @@ static int cgw_create_job(struct sk_buff *skb,  struct nlmsghdr *nlh)
         if (gwj->dst.dev->type != ARPHRD_CAN)
                 goto out;
 
-        gwj->limit_hops = limhops;
-
         ASSERT_RTNL();
 
         err = cgw_register_filter(gwj);
@@ -931,8 +968,15 @@ static int cgw_remove_job(struct sk_buff *skb, struct nlmsghdr *nlh)
                 if (gwj->limit_hops != limhops)
                         continue;
 
-                if (memcmp(&gwj->mod, &mod, sizeof(mod)))
-                        continue;
+                /* we have a match when uid is enabled and identical */
+                if (gwj->mod.uid || mod.uid) {
+                        if (gwj->mod.uid != mod.uid)
+                                continue;
+                } else {
+                        /* no uid => check for identical modifications */
+                        if (memcmp(&gwj->mod, &mod, sizeof(mod)))
+                                continue;
+                }
 
                 /* if (r->gwtype == CGW_TYPE_CAN_CAN) - is made sure here */
                 if (memcmp(&gwj->ccgw, &ccgw, sizeof(ccgw)))