For UDP socket lookup functions, and associateed functions that take an
skbuf as argument, declare the skb argument as constant.
One caveat is that reuseport_select_sock can be called from the UDP
lookup functions with an skb argument. This function temporarily
modifies the skbuff data pointer (in bpf_run via a pull/push sequence).
To resolve compiler warning I added a local skbuf declaration that is
not const and assigned to the skb argument with an explicit cast.
Signed-off-by: Tom Herbert <t...@quantonium.net>
---
include/net/ip.h | 2 +-
include/net/sock_reuseport.h | 2 +-
include/net/udp.h | 11 ++++++-----
net/core/sock_reuseport.c | 5 +++--
net/ipv4/udp.c | 11 ++++++-----
net/ipv6/udp.c | 10 +++++-----
6 files changed, 22 insertions(+), 19 deletions(-)
diff --git a/include/net/ip.h b/include/net/ip.h
index 9896f46cbbf1..8c0d84ffc659 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -79,7 +79,7 @@ struct ipcm_cookie {
#define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb))
/* return enslaved device index if relevant */
-static inline int inet_sdif(struct sk_buff *skb)
+static inline int inet_sdif(const struct sk_buff *skb)
{
#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
if (skb && ipv4_l3mdev_skb(IPCB(skb)->flags))
diff --git a/include/net/sock_reuseport.h b/include/net/sock_reuseport.h
index aecd30308d50..d25352a848d9 100644
--- a/include/net/sock_reuseport.h
+++ b/include/net/sock_reuseport.h
@@ -20,7 +20,7 @@ extern int reuseport_add_sock(struct sock *sk, struct sock
*sk2);
extern void reuseport_detach_sock(struct sock *sk);
extern struct sock *reuseport_select_sock(struct sock *sk,
u32 hash,
- struct sk_buff *skb,
+ const struct sk_buff *skb,
int hdr_len);
extern struct bpf_prog *reuseport_attach_prog(struct sock *sk,
struct bpf_prog *prog);
diff --git a/include/net/udp.h b/include/net/udp.h
index 4e5f23fec35e..f3d1de6f0983 100644
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -167,7 +167,7 @@ static inline void udp_csum_pull_header(struct sk_buff *skb)
UDP_SKB_CB(skb)->cscov -= sizeof(struct udphdr);
}
-typedef struct sock *(*udp_lookup_t)(struct sk_buff *skb, __be16 sport,
+typedef struct sock *(*udp_lookup_t)(const struct sk_buff *skb, __be16 sport,
__be16 dport);
struct sk_buff **udp_gro_receive(struct sk_buff **head, struct sk_buff *skb,
@@ -288,8 +288,9 @@ struct sock *udp4_lib_lookup(struct net *net, __be32 saddr,
__be16 sport,
__be32 daddr, __be16 dport, int dif);
struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
__be32 daddr, __be16 dport, int dif, int sdif,
- struct udp_table *tbl, struct sk_buff *skb);
-struct sock *udp4_lib_lookup_skb(struct sk_buff *skb,
+ struct udp_table *tbl,
+ const struct sk_buff *skb);
+struct sock *udp4_lib_lookup_skb(const struct sk_buff *skb,
__be16 sport, __be16 dport);
struct sock *udp6_lib_lookup(struct net *net,
const struct in6_addr *saddr, __be16 sport,
@@ -299,8 +300,8 @@ struct sock *__udp6_lib_lookup(struct net *net,
const struct in6_addr *saddr, __be16 sport,
const struct in6_addr *daddr, __be16 dport,
int dif, int sdif, struct udp_table *tbl,
- struct sk_buff *skb);
-struct sock *udp6_lib_lookup_skb(struct sk_buff *skb,
+ const struct sk_buff *skb);
+struct sock *udp6_lib_lookup_skb(const struct sk_buff *skb,
__be16 sport, __be16 dport);
/* UDP uses skb->dev_scratch to cache as much information as possible and avoid
diff --git a/net/core/sock_reuseport.c b/net/core/sock_reuseport.c
index eed1ebf7f29d..a17f13b33189 100644
--- a/net/core/sock_reuseport.c
+++ b/net/core/sock_reuseport.c
@@ -164,9 +164,10 @@ void reuseport_detach_sock(struct sock *sk)
EXPORT_SYMBOL(reuseport_detach_sock);
static struct sock *run_bpf(struct sock_reuseport *reuse, u16 socks,
- struct bpf_prog *prog, struct sk_buff *skb,
+ struct bpf_prog *prog, const struct sk_buff *_skb,
int hdr_len)
{
+ struct sk_buff *skb = (struct sk_buff *)_skb; /* Override const */
struct sk_buff *nskb = NULL;
u32 index;
@@ -205,7 +206,7 @@ static struct sock *run_bpf(struct sock_reuseport *reuse,
u16 socks,
*/
struct sock *reuseport_select_sock(struct sock *sk,
u32 hash,
- struct sk_buff *skb,
+ const struct sk_buff *skb,
int hdr_len)
{
struct sock_reuseport *reuse;
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index bf6c406bf5e7..a851026ef28b 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -135,7 +135,8 @@ EXPORT_SYMBOL(udp_memory_allocated);
#define PORTS_PER_CHAIN (MAX_UDP_PORTS / UDP_HTABLE_SIZE_MIN)
/* IPCB reference means this can not be used from early demux */
-static bool udp_lib_exact_dif_match(struct net *net, struct sk_buff *skb)
+static bool udp_lib_exact_dif_match(struct net *net,
+ const struct sk_buff *skb)
{
#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
if (!net->ipv4.sysctl_udp_l3mdev_accept &&
@@ -445,7 +446,7 @@ static struct sock *udp4_lib_lookup2(struct net *net,
__be32 daddr, unsigned int hnum,
int dif, int sdif, bool exact_dif,
struct udp_hslot *hslot2,
- struct sk_buff *skb)
+ const struct sk_buff *skb)
{
struct sock *sk, *result;
int score, badness, matches = 0, reuseport = 0;
@@ -484,7 +485,7 @@ static struct sock *udp4_lib_lookup2(struct net *net,
*/
struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
__be16 sport, __be32 daddr, __be16 dport, int dif,
- int sdif, struct udp_table *udptable, struct sk_buff *skb)
+ int sdif, struct udp_table *udptable, const struct sk_buff *skb)
{
struct sock *sk, *result;
unsigned short hnum = ntohs(dport);
@@ -552,7 +553,7 @@ struct sock *__udp4_lib_lookup(struct net *net, __be32
saddr,
}
EXPORT_SYMBOL_GPL(__udp4_lib_lookup);
-static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
+static inline struct sock *__udp4_lib_lookup_skb(const struct sk_buff *skb,
__be16 sport, __be16 dport,
struct udp_table *udptable)
{
@@ -563,7 +564,7 @@ static inline struct sock *__udp4_lib_lookup_skb(struct
sk_buff *skb,
inet_sdif(skb), udptable, skb);
}
-struct sock *udp4_lib_lookup_skb(struct sk_buff *skb,
+struct sock *udp4_lib_lookup_skb(const struct sk_buff *skb,
__be16 sport, __be16 dport)
{
return __udp4_lib_lookup_skb(skb, sport, dport, &udp_table);
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 976f30391356..e9aa4db3ba53 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -56,7 +56,7 @@
#include <trace/events/skb.h>
#include "udp_impl.h"
-static bool udp6_lib_exact_dif_match(struct net *net, struct sk_buff *skb)
+static bool udp6_lib_exact_dif_match(struct net *net, const struct sk_buff
*skb)
{
#if defined(CONFIG_NET_L3_MASTER_DEV)
if (!net->ipv4.sysctl_udp_l3mdev_accept &&
@@ -181,7 +181,7 @@ static struct sock *udp6_lib_lookup2(struct net *net,
const struct in6_addr *saddr, __be16 sport,
const struct in6_addr *daddr, unsigned int hnum,
int dif, int sdif, bool exact_dif,
- struct udp_hslot *hslot2, struct sk_buff *skb)
+ struct udp_hslot *hslot2, const struct sk_buff *skb)
{
struct sock *sk, *result;
int score, badness, matches = 0, reuseport = 0;
@@ -221,7 +221,7 @@ struct sock *__udp6_lib_lookup(struct net *net,
const struct in6_addr *saddr, __be16 sport,
const struct in6_addr *daddr, __be16 dport,
int dif, int sdif, struct udp_table *udptable,
- struct sk_buff *skb)
+ const struct sk_buff *skb)
{
struct sock *sk, *result;
unsigned short hnum = ntohs(dport);
@@ -290,7 +290,7 @@ struct sock *__udp6_lib_lookup(struct net *net,
}
EXPORT_SYMBOL_GPL(__udp6_lib_lookup);
-static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb,
+static struct sock *__udp6_lib_lookup_skb(const struct sk_buff *skb,
__be16 sport, __be16 dport,
struct udp_table *udptable)
{
@@ -301,7 +301,7 @@ static struct sock *__udp6_lib_lookup_skb(struct sk_buff
*skb,
inet6_sdif(skb), udptable, skb);
}
-struct sock *udp6_lib_lookup_skb(struct sk_buff *skb,
+struct sock *udp6_lib_lookup_skb(const struct sk_buff *skb,
__be16 sport, __be16 dport)
{
const struct ipv6hdr *iph = ipv6_hdr(skb);
--
2.11.0
