Applying the new member allow_tcp_access in the existing callbacks
where is_fullsock is set to 1 can help us stop UDP socket accessing
struct tcp_sock, or else it could be catastrophe leading to panic.
For now, those existing callbacks are used only for TCP. I believe
in the short run, we will have timestamping UDP callbacks support.
Signed-off-by: Jason Xing <kerneljasonxing@xxxxxxxxx>
---
include/linux/filter.h | 1 +
include/net/tcp.h | 1 +
net/core/filter.c | 8 ++++----
net/ipv4/tcp_input.c | 2 ++
net/ipv4/tcp_output.c | 2 ++
5 files changed, 10 insertions(+), 4 deletions(-)
diff --git a/include/linux/filter.h b/include/linux/filter.h
index a3ea46281595..1b1333a90b4a 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -1508,6 +1508,7 @@ struct bpf_sock_ops_kern {
void *skb_data_end;
u8 op;
u8 is_fullsock;
+ u8 allow_tcp_access;
u8 remaining_opt_len;
u64 temp; /* temp and everything after is not
* initialized to 0 before calling
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 5b2b04835688..293047694710 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2649,6 +2649,7 @@ static inline int tcp_call_bpf(struct sock *sk, int op, u32 nargs, u32 *args)
memset(&sock_ops, 0, offsetof(struct bpf_sock_ops_kern, temp));
if (sk_fullsock(sk)) {
sock_ops.is_fullsock = 1;
+ sock_ops.allow_tcp_access = 1;
sock_owned_by_me(sk);
}
diff --git a/net/core/filter.c b/net/core/filter.c
index 8e2715b7ac8a..fdd305b4cfbb 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -10381,10 +10381,10 @@ static u32 sock_ops_convert_ctx_access(enum bpf_access_type type,
} \
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF( \
struct bpf_sock_ops_kern, \
- is_fullsock), \
+ allow_tcp_access), \
fullsock_reg, si->src_reg, \
offsetof(struct bpf_sock_ops_kern, \
- is_fullsock)); \
+ allow_tcp_access)); \
*insn++ = BPF_JMP_IMM(BPF_JEQ, fullsock_reg, 0, jmp); \
if (si->dst_reg == si->src_reg) \
*insn++ = BPF_LDX_MEM(BPF_DW, reg, si->src_reg, \
@@ -10469,10 +10469,10 @@ static u32 sock_ops_convert_ctx_access(enum bpf_access_type type,
temp)); \
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF( \
struct bpf_sock_ops_kern, \
- is_fullsock), \
+ allow_tcp_access), \
reg, si->dst_reg, \
offsetof(struct bpf_sock_ops_kern, \
- is_fullsock)); \
+ allow_tcp_access)); \
*insn++ = BPF_JMP_IMM(BPF_JEQ, reg, 0, 2); \
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF( \
struct bpf_sock_ops_kern, sk),\
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index eb82e01da911..77185479ed5e 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -169,6 +169,7 @@ static void bpf_skops_parse_hdr(struct sock *sk, struct sk_buff *skb)
memset(&sock_ops, 0, offsetof(struct bpf_sock_ops_kern, temp));
sock_ops.op = BPF_SOCK_OPS_PARSE_HDR_OPT_CB;
sock_ops.is_fullsock = 1;
+ sock_ops.allow_tcp_access = 1;
sock_ops.sk = sk;
bpf_skops_init_skb(&sock_ops, skb, tcp_hdrlen(skb));
@@ -185,6 +186,7 @@ static void bpf_skops_established(struct sock *sk, int bpf_op,
memset(&sock_ops, 0, offsetof(struct bpf_sock_ops_kern, temp));
sock_ops.op = bpf_op;
sock_ops.is_fullsock = 1;
+ sock_ops.allow_tcp_access = 1;
sock_ops.sk = sk;
/* sk with TCP_REPAIR_ON does not have skb in tcp_finish_connect */
if (skb)
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 0e5b9a654254..695749807c09 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -522,6 +522,7 @@ static void bpf_skops_hdr_opt_len(struct sock *sk, struct sk_buff *skb,
sock_owned_by_me(sk);
sock_ops.is_fullsock = 1;
+ sock_ops.allow_tcp_access = 1;
sock_ops.sk = sk;
}
@@ -567,6 +568,7 @@ static void bpf_skops_write_hdr_opt(struct sock *sk, struct sk_buff *skb,
sock_owned_by_me(sk);
sock_ops.is_fullsock = 1;
+ sock_ops.allow_tcp_access = 1;
sock_ops.sk = sk;
}
--
2.43.5
