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Merge branch 'bpf-next' 

Daniel Borkmann says:

====================
BPF helper improvements and cleanups

This set adds various improvements to BPF helpers, a cleanup to use
skb_pkt_type_ok() helper, addition of bpf_skb_change_tail(), a follow
up for event output helper and removing ifdefs around the cgroupv2
helper bits. For details please see individual patches.

The set is based against net-next tree, but requires a merge of net
into net-next first.

Thanks a lot!
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2016-08-18 23:38:17 -07:00
parent b34040227b 54fd9c2dff
commit f1c89c033f
4 changed files with 204 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

43
include/linux/skbuff.h
View File

@ -2295,7 +2295,7 @@ static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len)
int ___pskb_trim(struct sk_buff *skb, unsigned int len);
static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
static inline void __skb_set_length(struct sk_buff *skb, unsigned int len)
{
if (unlikely(skb_is_nonlinear(skb))) {
WARN_ON(1);
@ -2305,6 +2305,11 @@ static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
skb_set_tail_pointer(skb, len);
}
static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
{
__skb_set_length(skb, len);
}
void skb_trim(struct sk_buff *skb, unsigned int len);
static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
@ -2335,6 +2340,20 @@ static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
BUG_ON(err);
}
static inline int __skb_grow(struct sk_buff *skb, unsigned int len)
{
unsigned int diff = len - skb->len;
if (skb_tailroom(skb) < diff) {
int ret = pskb_expand_head(skb, 0, diff - skb_tailroom(skb),
GFP_ATOMIC);
if (ret)
return ret;
}
__skb_set_length(skb, len);
return 0;
}
/**
* skb_orphan - orphan a buffer
* @skb: buffer to orphan
@ -2938,6 +2957,21 @@ static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
return __pskb_trim(skb, len);
}
static inline int __skb_trim_rcsum(struct sk_buff *skb, unsigned int len)
{
if (skb->ip_summed == CHECKSUM_COMPLETE)
skb->ip_summed = CHECKSUM_NONE;
__skb_trim(skb, len);
return 0;
}
static inline int __skb_grow_rcsum(struct sk_buff *skb, unsigned int len)
{
if (skb->ip_summed == CHECKSUM_COMPLETE)
skb->ip_summed = CHECKSUM_NONE;
return __skb_grow(skb, len);
}
#define skb_queue_walk(queue, skb) \
for (skb = (queue)->next; \
skb != (struct sk_buff *)(queue); \
@ -3726,6 +3760,13 @@ static inline bool skb_is_gso_v6(const struct sk_buff *skb)
return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
}
static inline void skb_gso_reset(struct sk_buff *skb)
{
skb_shinfo(skb)->gso_size = 0;
skb_shinfo(skb)->gso_segs = 0;
skb_shinfo(skb)->gso_type = 0;
}
void __skb_warn_lro_forwarding(const struct sk_buff *skb);
static inline bool skb_warn_if_lro(const struct sk_buff *skb)

10
include/net/sock.h
View File

@ -1114,6 +1114,16 @@ static inline bool sk_stream_is_writeable(const struct sock *sk)
sk_stream_memory_free(sk);
}
static inline int sk_under_cgroup_hierarchy(struct sock *sk,
struct cgroup *ancestor)
{
#ifdef CONFIG_SOCK_CGROUP_DATA
return cgroup_is_descendant(sock_cgroup_ptr(&sk->sk_cgrp_data),
ancestor);
#else
return -ENOTSUPP;
#endif
}
static inline bool sk_has_memory_pressure(const struct sock *sk)
{

11
include/uapi/linux/bpf.h
View File

@ -386,6 +386,17 @@ enum bpf_func_id {
*/
BPF_FUNC_current_task_under_cgroup,
/**
* bpf_skb_change_tail(skb, len, flags)
* The helper will resize the skb to the given new size,
* to be used f.e. with control messages.
* @skb: pointer to skb
* @len: new skb length
* @flags: reserved
* Return: 0 on success or negative error
*/
BPF_FUNC_skb_change_tail,
__BPF_FUNC_MAX_ID,
};

152
net/core/filter.c
View File

@ -1350,14 +1350,18 @@ struct bpf_scratchpad {
static DEFINE_PER_CPU(struct bpf_scratchpad, bpf_sp);
static inline int __bpf_try_make_writable(struct sk_buff *skb,
unsigned int write_len)
{
return skb_ensure_writable(skb, write_len);
}
static inline int bpf_try_make_writable(struct sk_buff *skb,
unsigned int write_len)
{
int err;
int err = __bpf_try_make_writable(skb, write_len);
err = skb_ensure_writable(skb, write_len);
bpf_compute_data_end(skb);
return err;
}
@ -1976,8 +1980,8 @@ static u64 bpf_skb_change_type(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
u32 pkt_type = r2;
/* We only allow a restricted subset to be changed for now. */
if (unlikely(skb->pkt_type > PACKET_OTHERHOST ||
pkt_type > PACKET_OTHERHOST))
if (unlikely(!skb_pkt_type_ok(skb->pkt_type) ||
!skb_pkt_type_ok(pkt_type)))
return -EINVAL;
skb->pkt_type = pkt_type;
@ -1992,6 +1996,92 @@ static const struct bpf_func_proto bpf_skb_change_type_proto = {
.arg2_type = ARG_ANYTHING,
};
static u32 __bpf_skb_min_len(const struct sk_buff *skb)
{
u32 min_len = skb_network_offset(skb);
if (skb_transport_header_was_set(skb))
min_len = skb_transport_offset(skb);
if (skb->ip_summed == CHECKSUM_PARTIAL)
min_len = skb_checksum_start_offset(skb) +
skb->csum_offset + sizeof(__sum16);
return min_len;
}
static u32 __bpf_skb_max_len(const struct sk_buff *skb)
{
return skb->dev ? skb->dev->mtu + skb->dev->hard_header_len :
65536;
}
static int bpf_skb_grow_rcsum(struct sk_buff *skb, unsigned int new_len)
{
unsigned int old_len = skb->len;
int ret;
ret = __skb_grow_rcsum(skb, new_len);
if (!ret)
memset(skb->data + old_len, 0, new_len - old_len);
return ret;
}
static int bpf_skb_trim_rcsum(struct sk_buff *skb, unsigned int new_len)
{
return __skb_trim_rcsum(skb, new_len);
}
static u64 bpf_skb_change_tail(u64 r1, u64 r2, u64 flags, u64 r4, u64 r5)
{
struct sk_buff *skb = (struct sk_buff *)(long) r1;
u32 max_len = __bpf_skb_max_len(skb);
u32 min_len = __bpf_skb_min_len(skb);
u32 new_len = (u32) r2;
int ret;
if (unlikely(flags || new_len > max_len || new_len < min_len))
return -EINVAL;
if (skb->encapsulation)
return -ENOTSUPP;
/* The basic idea of this helper is that it's performing the
* needed work to either grow or trim an skb, and eBPF program
* rewrites the rest via helpers like bpf_skb_store_bytes(),
* bpf_lX_csum_replace() and others rather than passing a raw
* buffer here. This one is a slow path helper and intended
* for replies with control messages.
*
* Like in bpf_skb_change_proto(), we want to keep this rather
* minimal and without protocol specifics so that we are able
* to separate concerns as in bpf_skb_store_bytes() should only
* be the one responsible for writing buffers.
*
* It's really expected to be a slow path operation here for
* control message replies, so we're implicitly linearizing,
* uncloning and drop offloads from the skb by this.
*/
ret = __bpf_try_make_writable(skb, skb->len);
if (!ret) {
if (new_len > skb->len)
ret = bpf_skb_grow_rcsum(skb, new_len);
else if (new_len < skb->len)
ret = bpf_skb_trim_rcsum(skb, new_len);
if (!ret && skb_is_gso(skb))
skb_gso_reset(skb);
}
bpf_compute_data_end(skb);
return ret;
}
static const struct bpf_func_proto bpf_skb_change_tail_proto = {
.func = bpf_skb_change_tail,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_ANYTHING,
.arg3_type = ARG_ANYTHING,
};
bool bpf_helper_changes_skb_data(void *func)
{
if (func == bpf_skb_vlan_push)
@ -2002,6 +2092,8 @@ bool bpf_helper_changes_skb_data(void *func)
return true;
if (func == bpf_skb_change_proto)
return true;
if (func == bpf_skb_change_tail)
return true;
if (func == bpf_l3_csum_replace)
return true;
if (func == bpf_l4_csum_replace)
@ -2282,7 +2374,6 @@ bpf_get_skb_set_tunnel_proto(enum bpf_func_id which)
}
}
#ifdef CONFIG_SOCK_CGROUP_DATA
static u64 bpf_skb_under_cgroup(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
{
struct sk_buff *skb = (struct sk_buff *)(long)r1;
@ -2303,7 +2394,7 @@ static u64 bpf_skb_under_cgroup(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
if (unlikely(!cgrp))
return -EAGAIN;
return cgroup_is_descendant(sock_cgroup_ptr(&sk->sk_cgrp_data), cgrp);
return sk_under_cgroup_hierarchy(sk, cgrp);
}
static const struct bpf_func_proto bpf_skb_under_cgroup_proto = {
@ -2314,7 +2405,41 @@ static const struct bpf_func_proto bpf_skb_under_cgroup_proto = {
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_ANYTHING,
};
#endif
static unsigned long bpf_xdp_copy(void *dst_buff, const void *src_buff,
unsigned long off, unsigned long len)
{
memcpy(dst_buff, src_buff + off, len);
return 0;
}
static u64 bpf_xdp_event_output(u64 r1, u64 r2, u64 flags, u64 r4,
u64 meta_size)
{
struct xdp_buff *xdp = (struct xdp_buff *)(long) r1;
struct bpf_map *map = (struct bpf_map *)(long) r2;
u64 xdp_size = (flags & BPF_F_CTXLEN_MASK) >> 32;
void *meta = (void *)(long) r4;
if (unlikely(flags & ~(BPF_F_CTXLEN_MASK | BPF_F_INDEX_MASK)))
return -EINVAL;
if (unlikely(xdp_size > (unsigned long)(xdp->data_end - xdp->data)))
return -EFAULT;
return bpf_event_output(map, flags, meta, meta_size, xdp, xdp_size,
bpf_xdp_copy);
}
static const struct bpf_func_proto bpf_xdp_event_output_proto = {
.func = bpf_xdp_event_output,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_ANYTHING,
.arg4_type = ARG_PTR_TO_STACK,
.arg5_type = ARG_CONST_STACK_SIZE,
};
static const struct bpf_func_proto *
sk_filter_func_proto(enum bpf_func_id func_id)
@ -2368,6 +2493,8 @@ tc_cls_act_func_proto(enum bpf_func_id func_id)
return &bpf_skb_change_proto_proto;
case BPF_FUNC_skb_change_type:
return &bpf_skb_change_type_proto;
case BPF_FUNC_skb_change_tail:
return &bpf_skb_change_tail_proto;
case BPF_FUNC_skb_get_tunnel_key:
return &bpf_skb_get_tunnel_key_proto;
case BPF_FUNC_skb_set_tunnel_key:
@ -2386,10 +2513,8 @@ tc_cls_act_func_proto(enum bpf_func_id func_id)
return &bpf_skb_event_output_proto;
case BPF_FUNC_get_smp_processor_id:
return &bpf_get_smp_processor_id_proto;
#ifdef CONFIG_SOCK_CGROUP_DATA
case BPF_FUNC_skb_under_cgroup:
return &bpf_skb_under_cgroup_proto;
#endif
default:
return sk_filter_func_proto(func_id);
}
@ -2398,7 +2523,12 @@ tc_cls_act_func_proto(enum bpf_func_id func_id)
static const struct bpf_func_proto *
xdp_func_proto(enum bpf_func_id func_id)
{
return sk_filter_func_proto(func_id);
switch (func_id) {
case BPF_FUNC_perf_event_output:
return &bpf_xdp_event_output_proto;
default:
return sk_filter_func_proto(func_id);
}
}
static bool __is_valid_access(int off, int size, enum bpf_access_type type)