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authorJohannes Berg <johannes.berg@intel.com>2015-01-17 00:09:00 +0300
committerDavid S. Miller <davem@davemloft.net>2015-01-18 09:03:45 +0300
commit053c095a82cf773075e83d7233b5cc19a1f73ece (patch)
treec787028efa9a73a182a0f338f87b6294cef4b8b9 /net/ipv6
parentede58ef28e105de94475b2b69fa069c9a2ce6933 (diff)
downloadlinux-053c095a82cf773075e83d7233b5cc19a1f73ece.tar.xz
netlink: make nlmsg_end() and genlmsg_end() void
Contrary to common expectations for an "int" return, these functions return only a positive value -- if used correctly they cannot even return 0 because the message header will necessarily be in the skb. This makes the very common pattern of if (genlmsg_end(...) < 0) { ... } be a whole bunch of dead code. Many places also simply do return nlmsg_end(...); and the caller is expected to deal with it. This also commonly (at least for me) causes errors, because it is very common to write if (my_function(...)) /* error condition */ and if my_function() does "return nlmsg_end()" this is of course wrong. Additionally, there's not a single place in the kernel that actually needs the message length returned, and if anyone needs it later then it'll be very easy to just use skb->len there. Remove this, and make the functions void. This removes a bunch of dead code as described above. The patch adds lines because I did - return nlmsg_end(...); + nlmsg_end(...); + return 0; I could have preserved all the function's return values by returning skb->len, but instead I've audited all the places calling the affected functions and found that none cared. A few places actually compared the return value with <= 0 in dump functionality, but that could just be changed to < 0 with no change in behaviour, so I opted for the more efficient version. One instance of the error I've made numerous times now is also present in net/phonet/pn_netlink.c in the route_dumpit() function - it didn't check for <0 or <=0 and thus broke out of the loop every single time. I've preserved this since it will (I think) have caused the messages to userspace to be formatted differently with just a single message for every SKB returned to userspace. It's possible that this isn't needed for the tools that actually use this, but I don't even know what they are so couldn't test that changing this behaviour would be acceptable. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6')
-rw-r--r--net/ipv6/addrconf.c32
-rw-r--r--net/ipv6/addrlabel.c5
-rw-r--r--net/ipv6/ip6_fib.c1
-rw-r--r--net/ipv6/ip6mr.c3
-rw-r--r--net/ipv6/route.c3
5 files changed, 26 insertions, 18 deletions
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index f7c8bbeb27b7..8975d9501d50 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -489,7 +489,8 @@ static int inet6_netconf_fill_devconf(struct sk_buff *skb, int ifindex,
nla_put_s32(skb, NETCONFA_PROXY_NEIGH, devconf->proxy_ndp) < 0)
goto nla_put_failure;
- return nlmsg_end(skb, nlh);
+ nlmsg_end(skb, nlh);
+ return 0;
nla_put_failure:
nlmsg_cancel(skb, nlh);
@@ -619,7 +620,7 @@ static int inet6_netconf_dump_devconf(struct sk_buff *skb,
cb->nlh->nlmsg_seq,
RTM_NEWNETCONF,
NLM_F_MULTI,
- -1) <= 0) {
+ -1) < 0) {
rcu_read_unlock();
goto done;
}
@@ -635,7 +636,7 @@ cont:
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq,
RTM_NEWNETCONF, NLM_F_MULTI,
- -1) <= 0)
+ -1) < 0)
goto done;
else
h++;
@@ -646,7 +647,7 @@ cont:
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq,
RTM_NEWNETCONF, NLM_F_MULTI,
- -1) <= 0)
+ -1) < 0)
goto done;
else
h++;
@@ -4047,7 +4048,8 @@ static int inet6_fill_ifaddr(struct sk_buff *skb, struct inet6_ifaddr *ifa,
if (nla_put_u32(skb, IFA_FLAGS, ifa->flags) < 0)
goto error;
- return nlmsg_end(skb, nlh);
+ nlmsg_end(skb, nlh);
+ return 0;
error:
nlmsg_cancel(skb, nlh);
@@ -4076,7 +4078,8 @@ static int inet6_fill_ifmcaddr(struct sk_buff *skb, struct ifmcaddr6 *ifmca,
return -EMSGSIZE;
}
- return nlmsg_end(skb, nlh);
+ nlmsg_end(skb, nlh);
+ return 0;
}
static int inet6_fill_ifacaddr(struct sk_buff *skb, struct ifacaddr6 *ifaca,
@@ -4101,7 +4104,8 @@ static int inet6_fill_ifacaddr(struct sk_buff *skb, struct ifacaddr6 *ifaca,
return -EMSGSIZE;
}
- return nlmsg_end(skb, nlh);
+ nlmsg_end(skb, nlh);
+ return 0;
}
enum addr_type_t {
@@ -4134,7 +4138,7 @@ static int in6_dump_addrs(struct inet6_dev *idev, struct sk_buff *skb,
cb->nlh->nlmsg_seq,
RTM_NEWADDR,
NLM_F_MULTI);
- if (err <= 0)
+ if (err < 0)
break;
nl_dump_check_consistent(cb, nlmsg_hdr(skb));
}
@@ -4151,7 +4155,7 @@ static int in6_dump_addrs(struct inet6_dev *idev, struct sk_buff *skb,
cb->nlh->nlmsg_seq,
RTM_GETMULTICAST,
NLM_F_MULTI);
- if (err <= 0)
+ if (err < 0)
break;
}
break;
@@ -4166,7 +4170,7 @@ static int in6_dump_addrs(struct inet6_dev *idev, struct sk_buff *skb,
cb->nlh->nlmsg_seq,
RTM_GETANYCAST,
NLM_F_MULTI);
- if (err <= 0)
+ if (err < 0)
break;
}
break;
@@ -4638,7 +4642,8 @@ static int inet6_fill_ifinfo(struct sk_buff *skb, struct inet6_dev *idev,
goto nla_put_failure;
nla_nest_end(skb, protoinfo);
- return nlmsg_end(skb, nlh);
+ nlmsg_end(skb, nlh);
+ return 0;
nla_put_failure:
nlmsg_cancel(skb, nlh);
@@ -4670,7 +4675,7 @@ static int inet6_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
if (inet6_fill_ifinfo(skb, idev,
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq,
- RTM_NEWLINK, NLM_F_MULTI) <= 0)
+ RTM_NEWLINK, NLM_F_MULTI) < 0)
goto out;
cont:
idx++;
@@ -4747,7 +4752,8 @@ static int inet6_fill_prefix(struct sk_buff *skb, struct inet6_dev *idev,
ci.valid_time = ntohl(pinfo->valid);
if (nla_put(skb, PREFIX_CACHEINFO, sizeof(ci), &ci))
goto nla_put_failure;
- return nlmsg_end(skb, nlh);
+ nlmsg_end(skb, nlh);
+ return 0;
nla_put_failure:
nlmsg_cancel(skb, nlh);
diff --git a/net/ipv6/addrlabel.c b/net/ipv6/addrlabel.c
index fd0dc47f471d..e43e79d0a612 100644
--- a/net/ipv6/addrlabel.c
+++ b/net/ipv6/addrlabel.c
@@ -490,7 +490,8 @@ static int ip6addrlbl_fill(struct sk_buff *skb,
return -EMSGSIZE;
}
- return nlmsg_end(skb, nlh);
+ nlmsg_end(skb, nlh);
+ return 0;
}
static int ip6addrlbl_dump(struct sk_buff *skb, struct netlink_callback *cb)
@@ -510,7 +511,7 @@ static int ip6addrlbl_dump(struct sk_buff *skb, struct netlink_callback *cb)
cb->nlh->nlmsg_seq,
RTM_NEWADDRLABEL,
NLM_F_MULTI);
- if (err <= 0)
+ if (err < 0)
break;
}
idx++;
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 03c520a4ebeb..53775ee7d376 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -277,7 +277,6 @@ static int fib6_dump_node(struct fib6_walker *w)
w->leaf = rt;
return 1;
}
- WARN_ON(res == 0);
}
w->leaf = NULL;
return 0;
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index 722669754bbf..34b682617f50 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -2388,7 +2388,8 @@ static int ip6mr_fill_mroute(struct mr6_table *mrt, struct sk_buff *skb,
if (err < 0 && err != -ENOENT)
goto nla_put_failure;
- return nlmsg_end(skb, nlh);
+ nlmsg_end(skb, nlh);
+ return 0;
nla_put_failure:
nlmsg_cancel(skb, nlh);
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 34dcbb59df75..c60f15775c53 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -2725,7 +2725,8 @@ static int rt6_fill_node(struct net *net,
if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, rt->dst.error) < 0)
goto nla_put_failure;
- return nlmsg_end(skb, nlh);
+ nlmsg_end(skb, nlh);
+ return 0;
nla_put_failure:
nlmsg_cancel(skb, nlh);