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authorLinus Lüssing <linus.luessing@c0d3.blue>2019-01-21 07:26:26 +0100
committerDavid S. Miller <davem@davemloft.net>2019-01-22 17:18:08 -0800
commita2e2ca3bebe273055a212d754ffe4e0264192d74 (patch)
tree7e67a61e9eafae3581f2995fbc54b65aacd72f8c /net/ipv4
parentbridge: simplify ip_mc_check_igmp() and ipv6_mc_check_mld() calls (diff)
downloadlinux-dev-a2e2ca3bebe273055a212d754ffe4e0264192d74.tar.xz
linux-dev-a2e2ca3bebe273055a212d754ffe4e0264192d74.zip
bridge: simplify ip_mc_check_igmp() and ipv6_mc_check_mld() internals
With this patch the internal use of the skb_trimmed is reduced to the ICMPv6/IGMP checksum verification. And for the length checks the newly introduced helper functions are used instead of calculating and checking with skb->len directly. These changes should hopefully make it easier to verify that length checks are performed properly. Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
-rw-r--r--net/ipv4/igmp.c51
1 files changed, 22 insertions, 29 deletions
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index b1f6d93282d7..a40e48ded10d 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -1493,22 +1493,22 @@ static int ip_mc_check_igmp_reportv3(struct sk_buff *skb)
len += sizeof(struct igmpv3_report);
- return pskb_may_pull(skb, len) ? 0 : -EINVAL;
+ return ip_mc_may_pull(skb, len) ? 0 : -EINVAL;
}
static int ip_mc_check_igmp_query(struct sk_buff *skb)
{
- unsigned int len = skb_transport_offset(skb);
-
- len += sizeof(struct igmphdr);
- if (skb->len < len)
- return -EINVAL;
+ unsigned int transport_len = ip_transport_len(skb);
+ unsigned int len;
/* IGMPv{1,2}? */
- if (skb->len != len) {
+ if (transport_len != sizeof(struct igmphdr)) {
/* or IGMPv3? */
- len += sizeof(struct igmpv3_query) - sizeof(struct igmphdr);
- if (skb->len < len || !pskb_may_pull(skb, len))
+ if (transport_len < sizeof(struct igmpv3_query))
+ return -EINVAL;
+
+ len = skb_transport_offset(skb) + sizeof(struct igmpv3_query);
+ if (!ip_mc_may_pull(skb, len))
return -EINVAL;
}
@@ -1544,35 +1544,24 @@ static inline __sum16 ip_mc_validate_checksum(struct sk_buff *skb)
return skb_checksum_simple_validate(skb);
}
-static int __ip_mc_check_igmp(struct sk_buff *skb)
-
+static int ip_mc_check_igmp_csum(struct sk_buff *skb)
{
- struct sk_buff *skb_chk;
- unsigned int transport_len;
unsigned int len = skb_transport_offset(skb) + sizeof(struct igmphdr);
- int ret = -EINVAL;
+ unsigned int transport_len = ip_transport_len(skb);
+ struct sk_buff *skb_chk;
- transport_len = ntohs(ip_hdr(skb)->tot_len) - ip_hdrlen(skb);
+ if (!ip_mc_may_pull(skb, len))
+ return -EINVAL;
skb_chk = skb_checksum_trimmed(skb, transport_len,
ip_mc_validate_checksum);
if (!skb_chk)
- goto err;
-
- if (!pskb_may_pull(skb_chk, len))
- goto err;
-
- ret = ip_mc_check_igmp_msg(skb_chk);
- if (ret)
- goto err;
-
- ret = 0;
+ return -EINVAL;
-err:
- if (skb_chk && skb_chk != skb)
+ if (skb_chk != skb)
kfree_skb(skb_chk);
- return ret;
+ return 0;
}
/**
@@ -1600,7 +1589,11 @@ int ip_mc_check_igmp(struct sk_buff *skb)
if (ip_hdr(skb)->protocol != IPPROTO_IGMP)
return -ENOMSG;
- return __ip_mc_check_igmp(skb);
+ ret = ip_mc_check_igmp_csum(skb);
+ if (ret < 0)
+ return ret;
+
+ return ip_mc_check_igmp_msg(skb);
}
EXPORT_SYMBOL(ip_mc_check_igmp);