IPPROTO_MAX used to be 256, but with the introduction of IPPROTO_MPTCP
definition, IPPROTO_MAX was bumped to 263.
IPPROTO_MPTCP definition is used for the socket interface from
userspace (ie. uAPI). It is never used in the layer 4 protocol field of
IP headers.
IPPROTO_* definitions are used anywhere in the kernel as well as in
userspace to set the layer 4 protocol field in IP headers as well as
for uAPI.
At least in Netfilter, there is code in userspace that relies on
IPPROTO_MAX (not inclusive) to check for the maximum layer 4 protocol.
This patch restores IPPROTO_MAX to 256 for the maximum protocol number
in the IP headers, and it adds a new IPPROTO_UAPI_MAX for the maximum
protocol number for uAPI.
Update kernel code to use IPPROTO_UAPI_MAX for inet_diag (mptcp
registers one for this) and the inet{4,6}_create() IP socket API.
Fixes: faf391c3826c ("tcp: Define IPPROTO_MPTCP")
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
v2: Add IPPROTO_UAPI_MAX so mptcp socket API does not break.
include/uapi/linux/in.h | 3 ++-
net/ipv4/af_inet.c | 2 +-
net/ipv4/inet_diag.c | 8 ++++----
net/ipv6/af_inet6.c | 2 +-
4 files changed, 8 insertions(+), 7 deletions(-)
diff --git a/include/uapi/linux/in.h b/include/uapi/linux/in.h
index 4b7f2df66b99..58ca09438bf0 100644
--- a/include/uapi/linux/in.h
+++ b/include/uapi/linux/in.h
@@ -80,10 +80,11 @@ enum {
IPPROTO_ETHERNET = 143, /* Ethernet-within-IPv6 Encapsulation */
#define IPPROTO_ETHERNET IPPROTO_ETHERNET
IPPROTO_RAW = 255, /* Raw IP packets */
+ IPPROTO_MAX,
#define IPPROTO_RAW IPPROTO_RAW
IPPROTO_MPTCP = 262, /* Multipath TCP connection */
#define IPPROTO_MPTCP IPPROTO_MPTCP
- IPPROTO_MAX
+ IPPROTO_UAPI_MAX
};
#endif
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 8db6747f892f..4a9061da8983 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -252,7 +252,7 @@ static int inet_create(struct net *net, struct socket *sock, int protocol,
int try_loading_module = 0;
int err;
- if (protocol < 0 || protocol >= IPPROTO_MAX)
+ if (protocol < 0 || protocol >= IPPROTO_UAPI_MAX)
return -EINVAL;
sock->state = SS_UNCONNECTED;
diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index b812eb36f0e3..0723bef44827 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -52,7 +52,7 @@ static DEFINE_MUTEX(inet_diag_table_mutex);
static const struct inet_diag_handler *inet_diag_lock_handler(int proto)
{
- if (proto < 0 || proto >= IPPROTO_MAX) {
+ if (proto < 0 || proto >= IPPROTO_UAPI_MAX) {
mutex_lock(&inet_diag_table_mutex);
return ERR_PTR(-ENOENT);
}
@@ -1413,7 +1413,7 @@ int inet_diag_register(const struct inet_diag_handler *h)
const __u16 type = h->idiag_type;
int err = -EINVAL;
- if (type >= IPPROTO_MAX)
+ if (type >= IPPROTO_UAPI_MAX)
goto out;
mutex_lock(&inet_diag_table_mutex);
@@ -1432,7 +1432,7 @@ void inet_diag_unregister(const struct inet_diag_handler *h)
{
const __u16 type = h->idiag_type;
- if (type >= IPPROTO_MAX)
+ if (type >= IPPROTO_UAPI_MAX)
return;
mutex_lock(&inet_diag_table_mutex);
@@ -1443,7 +1443,7 @@ EXPORT_SYMBOL_GPL(inet_diag_unregister);
static int __init inet_diag_init(void)
{
- const int inet_diag_table_size = (IPPROTO_MAX *
+ const int inet_diag_table_size = (IPPROTO_UAPI_MAX *
sizeof(struct inet_diag_handler *));
int err = -ENOMEM;
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 38689bedfce7..64d5c803f070 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -128,7 +128,7 @@ static int inet6_create(struct net *net, struct socket *sock, int protocol,
int try_loading_module = 0;
int err;
- if (protocol < 0 || protocol >= IPPROTO_MAX)
+ if (protocol < 0 || protocol >= IPPROTO_UAPI_MAX)
return -EINVAL;
/* Look for the requested type/protocol pair. */
--
2.30.2
