* [PATCH v4 bpf-next 0/2] bpf: add cg_skb_is_valid_access
@ 2018-10-18 16:06 Song Liu
2018-10-18 16:06 ` [PATCH v4 bpf-next 1/2] bpf: add cg_skb_is_valid_access for BPF_PROG_TYPE_CGROUP_SKB Song Liu
` (2 more replies)
0 siblings, 3 replies; 8+ messages in thread
From: Song Liu @ 2018-10-18 16:06 UTC (permalink / raw)
To: netdev; +Cc: ast, daniel, kernel-team, Song Liu
Changes v3 -> v4:
1. Fixed crash issue reported by Alexei.
Changes v2 -> v3:
1. Added helper function bpf_compute_and_save_data_pointers() and
bpf_restore_data_pointers().
Changes v1 -> v2:
1. Updated the list of read-only fields, and read-write fields.
2. Added dummy sk to bpf_prog_test_run_skb().
This set enables BPF program of type BPF_PROG_TYPE_CGROUP_SKB to access
some __skb_buff data directly.
Song Liu (2):
bpf: add cg_skb_is_valid_access for BPF_PROG_TYPE_CGROUP_SKB
bpf: add tests for direct packet access from CGROUP_SKB
include/linux/filter.h | 24 +++
kernel/bpf/cgroup.c | 6 +
net/bpf/test_run.c | 7 +
net/core/filter.c | 36 ++++-
tools/testing/selftests/bpf/test_verifier.c | 170 ++++++++++++++++++++
5 files changed, 242 insertions(+), 1 deletion(-)
^ permalink raw reply [flat|nested] 8+ messages in thread* [PATCH v4 bpf-next 1/2] bpf: add cg_skb_is_valid_access for BPF_PROG_TYPE_CGROUP_SKB 2018-10-18 16:06 [PATCH v4 bpf-next 0/2] bpf: add cg_skb_is_valid_access Song Liu @ 2018-10-18 16:06 ` Song Liu 2018-10-19 0:14 ` Daniel Borkmann 2018-10-18 16:06 ` [PATCH v4 bpf-next 2/2] bpf: add tests for direct packet access from CGROUP_SKB Song Liu 2018-10-18 23:34 ` [PATCH v4 bpf-next 0/2] bpf: add cg_skb_is_valid_access Alexei Starovoitov 2 siblings, 1 reply; 8+ messages in thread From: Song Liu @ 2018-10-18 16:06 UTC (permalink / raw) To: netdev; +Cc: ast, daniel, kernel-team, Song Liu BPF programs of BPF_PROG_TYPE_CGROUP_SKB need to access headers in the skb. This patch enables direct access of skb for these programs. Two helper functions bpf_compute_and_save_data_pointers() and bpf_restore_data_pointers() are introduced. There are used in __cgroup_bpf_run_filter_skb(), to compute proper data_end for the BPF program, and restore original data afterwards. Signed-off-by: Song Liu <songliubraving@fb.com> --- include/linux/filter.h | 24 ++++++++++++++++++++++++ kernel/bpf/cgroup.c | 6 ++++++ net/core/filter.c | 36 +++++++++++++++++++++++++++++++++++- 3 files changed, 65 insertions(+), 1 deletion(-) diff --git a/include/linux/filter.h b/include/linux/filter.h index 5771874bc01e..96b3ee7f14c9 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -548,6 +548,30 @@ static inline void bpf_compute_data_pointers(struct sk_buff *skb) cb->data_end = skb->data + skb_headlen(skb); } +/* Similar to bpf_compute_data_pointers(), except that save orginal + * data in cb->data and cb->meta_data for restore. + */ +static inline void bpf_compute_and_save_data_pointers( + struct sk_buff *skb, void *saved_pointers[2]) +{ + struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb; + + saved_pointers[0] = cb->data_meta; + saved_pointers[1] = cb->data_end; + cb->data_meta = skb->data - skb_metadata_len(skb); + cb->data_end = skb->data + skb_headlen(skb); +} + +/* Restore data saved by bpf_compute_data_pointers(). */ +static inline void bpf_restore_data_pointers( + struct sk_buff *skb, void *saved_pointers[2]) +{ + struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb; + + cb->data_meta = saved_pointers[0]; + cb->data_end = saved_pointers[1];; +} + static inline u8 *bpf_skb_cb(struct sk_buff *skb) { /* eBPF programs may read/write skb->cb[] area to transfer meta diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index 00f6ed2e4f9a..5f5180104ddc 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -554,6 +554,7 @@ int __cgroup_bpf_run_filter_skb(struct sock *sk, unsigned int offset = skb->data - skb_network_header(skb); struct sock *save_sk; struct cgroup *cgrp; + void *saved_pointers[2]; int ret; if (!sk || !sk_fullsock(sk)) @@ -566,8 +567,13 @@ int __cgroup_bpf_run_filter_skb(struct sock *sk, save_sk = skb->sk; skb->sk = sk; __skb_push(skb, offset); + + /* compute pointers for the bpf prog */ + bpf_compute_and_save_data_pointers(skb, saved_pointers); + ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], skb, bpf_prog_run_save_cb); + bpf_restore_data_pointers(skb, saved_pointers); __skb_pull(skb, offset); skb->sk = save_sk; return ret == 1 ? 0 : -EPERM; diff --git a/net/core/filter.c b/net/core/filter.c index 1a3ac6c46873..e3ca30bd6840 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -5346,6 +5346,40 @@ static bool sk_filter_is_valid_access(int off, int size, return bpf_skb_is_valid_access(off, size, type, prog, info); } +static bool cg_skb_is_valid_access(int off, int size, + enum bpf_access_type type, + const struct bpf_prog *prog, + struct bpf_insn_access_aux *info) +{ + switch (off) { + case bpf_ctx_range(struct __sk_buff, tc_classid): + case bpf_ctx_range(struct __sk_buff, data_meta): + case bpf_ctx_range(struct __sk_buff, flow_keys): + return false; + } + if (type == BPF_WRITE) { + switch (off) { + case bpf_ctx_range(struct __sk_buff, mark): + case bpf_ctx_range(struct __sk_buff, priority): + case bpf_ctx_range_till(struct __sk_buff, cb[0], cb[4]): + break; + default: + return false; + } + } + + switch (off) { + case bpf_ctx_range(struct __sk_buff, data): + info->reg_type = PTR_TO_PACKET; + break; + case bpf_ctx_range(struct __sk_buff, data_end): + info->reg_type = PTR_TO_PACKET_END; + break; + } + + return bpf_skb_is_valid_access(off, size, type, prog, info); +} + static bool lwt_is_valid_access(int off, int size, enum bpf_access_type type, const struct bpf_prog *prog, @@ -7038,7 +7072,7 @@ const struct bpf_prog_ops xdp_prog_ops = { const struct bpf_verifier_ops cg_skb_verifier_ops = { .get_func_proto = cg_skb_func_proto, - .is_valid_access = sk_filter_is_valid_access, + .is_valid_access = cg_skb_is_valid_access, .convert_ctx_access = bpf_convert_ctx_access, }; -- 2.17.1 ^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH v4 bpf-next 1/2] bpf: add cg_skb_is_valid_access for BPF_PROG_TYPE_CGROUP_SKB 2018-10-18 16:06 ` [PATCH v4 bpf-next 1/2] bpf: add cg_skb_is_valid_access for BPF_PROG_TYPE_CGROUP_SKB Song Liu @ 2018-10-19 0:14 ` Daniel Borkmann 2018-10-19 1:33 ` Alexei Starovoitov 0 siblings, 1 reply; 8+ messages in thread From: Daniel Borkmann @ 2018-10-19 0:14 UTC (permalink / raw) To: Song Liu, netdev; +Cc: ast, kernel-team On 10/18/2018 06:06 PM, Song Liu wrote: > BPF programs of BPF_PROG_TYPE_CGROUP_SKB need to access headers in the > skb. This patch enables direct access of skb for these programs. > > Two helper functions bpf_compute_and_save_data_pointers() and > bpf_restore_data_pointers() are introduced. There are used in > __cgroup_bpf_run_filter_skb(), to compute proper data_end for the > BPF program, and restore original data afterwards. > > Signed-off-by: Song Liu <songliubraving@fb.com> > --- > include/linux/filter.h | 24 ++++++++++++++++++++++++ > kernel/bpf/cgroup.c | 6 ++++++ > net/core/filter.c | 36 +++++++++++++++++++++++++++++++++++- > 3 files changed, 65 insertions(+), 1 deletion(-) > > diff --git a/include/linux/filter.h b/include/linux/filter.h > index 5771874bc01e..96b3ee7f14c9 100644 > --- a/include/linux/filter.h > +++ b/include/linux/filter.h > @@ -548,6 +548,30 @@ static inline void bpf_compute_data_pointers(struct sk_buff *skb) > cb->data_end = skb->data + skb_headlen(skb); > } > > +/* Similar to bpf_compute_data_pointers(), except that save orginal > + * data in cb->data and cb->meta_data for restore. > + */ > +static inline void bpf_compute_and_save_data_pointers( > + struct sk_buff *skb, void *saved_pointers[2]) > +{ > + struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb; > + > + saved_pointers[0] = cb->data_meta; > + saved_pointers[1] = cb->data_end; > + cb->data_meta = skb->data - skb_metadata_len(skb); > + cb->data_end = skb->data + skb_headlen(skb); Hmm, can you elaborate why populating data_meta here ... > +} > + > +/* Restore data saved by bpf_compute_data_pointers(). */ > +static inline void bpf_restore_data_pointers( > + struct sk_buff *skb, void *saved_pointers[2]) > +{ > + struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb; > + > + cb->data_meta = saved_pointers[0]; > + cb->data_end = saved_pointers[1];; > +} > + > static inline u8 *bpf_skb_cb(struct sk_buff *skb) > { > /* eBPF programs may read/write skb->cb[] area to transfer meta > diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c > index 00f6ed2e4f9a..5f5180104ddc 100644 > --- a/kernel/bpf/cgroup.c > +++ b/kernel/bpf/cgroup.c > @@ -554,6 +554,7 @@ int __cgroup_bpf_run_filter_skb(struct sock *sk, > unsigned int offset = skb->data - skb_network_header(skb); > struct sock *save_sk; > struct cgroup *cgrp; > + void *saved_pointers[2]; > int ret; > > if (!sk || !sk_fullsock(sk)) > @@ -566,8 +567,13 @@ int __cgroup_bpf_run_filter_skb(struct sock *sk, > save_sk = skb->sk; > skb->sk = sk; > __skb_push(skb, offset); > + > + /* compute pointers for the bpf prog */ > + bpf_compute_and_save_data_pointers(skb, saved_pointers); > + > ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], skb, > bpf_prog_run_save_cb); > + bpf_restore_data_pointers(skb, saved_pointers); > __skb_pull(skb, offset); > skb->sk = save_sk; > return ret == 1 ? 0 : -EPERM; > diff --git a/net/core/filter.c b/net/core/filter.c > index 1a3ac6c46873..e3ca30bd6840 100644 > --- a/net/core/filter.c > +++ b/net/core/filter.c > @@ -5346,6 +5346,40 @@ static bool sk_filter_is_valid_access(int off, int size, > return bpf_skb_is_valid_access(off, size, type, prog, info); > } > > +static bool cg_skb_is_valid_access(int off, int size, > + enum bpf_access_type type, > + const struct bpf_prog *prog, > + struct bpf_insn_access_aux *info) > +{ > + switch (off) { > + case bpf_ctx_range(struct __sk_buff, tc_classid): > + case bpf_ctx_range(struct __sk_buff, data_meta): > + case bpf_ctx_range(struct __sk_buff, flow_keys): > + return false; ... if it's disallowed anyway (disallowing it is the right thing to do, but no need to save/restore then..)? > + } > + if (type == BPF_WRITE) { > + switch (off) { > + case bpf_ctx_range(struct __sk_buff, mark): > + case bpf_ctx_range(struct __sk_buff, priority): > + case bpf_ctx_range_till(struct __sk_buff, cb[0], cb[4]): > + break; > + default: > + return false; > + } > + } > + > + switch (off) { > + case bpf_ctx_range(struct __sk_buff, data): > + info->reg_type = PTR_TO_PACKET; > + break; > + case bpf_ctx_range(struct __sk_buff, data_end): > + info->reg_type = PTR_TO_PACKET_END; > + break; > + } > + > + return bpf_skb_is_valid_access(off, size, type, prog, info); > +} > + > static bool lwt_is_valid_access(int off, int size, > enum bpf_access_type type, > const struct bpf_prog *prog, > @@ -7038,7 +7072,7 @@ const struct bpf_prog_ops xdp_prog_ops = { > > const struct bpf_verifier_ops cg_skb_verifier_ops = { > .get_func_proto = cg_skb_func_proto, > - .is_valid_access = sk_filter_is_valid_access, > + .is_valid_access = cg_skb_is_valid_access, > .convert_ctx_access = bpf_convert_ctx_access, > }; > > ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v4 bpf-next 1/2] bpf: add cg_skb_is_valid_access for BPF_PROG_TYPE_CGROUP_SKB 2018-10-19 0:14 ` Daniel Borkmann @ 2018-10-19 1:33 ` Alexei Starovoitov 2018-10-19 2:03 ` Alexei Starovoitov 0 siblings, 1 reply; 8+ messages in thread From: Alexei Starovoitov @ 2018-10-19 1:33 UTC (permalink / raw) To: Daniel Borkmann, Song Liu, netdev@vger.kernel.org Cc: ast@kernel.org, Kernel Team On 10/18/18 5:14 PM, Daniel Borkmann wrote: >> + case bpf_ctx_range(struct __sk_buff, data_meta): >> + case bpf_ctx_range(struct __sk_buff, flow_keys): >> + return false; > ... if it's disallowed anyway (disallowing it is the right thing to do, > but no need to save/restore then..)? > that's a good point. why shouldn't we allow cg_skb to access data_meta? xdp can set it and cgroup_skb_ingress will consume it here. ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v4 bpf-next 1/2] bpf: add cg_skb_is_valid_access for BPF_PROG_TYPE_CGROUP_SKB 2018-10-19 1:33 ` Alexei Starovoitov @ 2018-10-19 2:03 ` Alexei Starovoitov 0 siblings, 0 replies; 8+ messages in thread From: Alexei Starovoitov @ 2018-10-19 2:03 UTC (permalink / raw) To: Daniel Borkmann, Song Liu, netdev@vger.kernel.org Cc: ast@kernel.org, Kernel Team On 10/18/18 6:33 PM, Alexei Starovoitov wrote: > On 10/18/18 5:14 PM, Daniel Borkmann wrote: >>> + case bpf_ctx_range(struct __sk_buff, data_meta): >>> + case bpf_ctx_range(struct __sk_buff, flow_keys): >>> + return false; >> ... if it's disallowed anyway (disallowing it is the right thing to do, >> but no need to save/restore then..)? >> > > that's a good point. > why shouldn't we allow cg_skb to access data_meta? > xdp can set it and cgroup_skb_ingress will consume it here. I'll take it back. When xdp doesn't set meta_data it will be zero and bpf_compute_data_pointers() will point data_meta to skb->data. On ingress that's eth header, but for tx it will point to reserved space for future eth header. So we cannot do that. Let's keep it disabled and adjust bpf_compute_and_save_data_pointers() to save only 'data' pointer. ^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH v4 bpf-next 2/2] bpf: add tests for direct packet access from CGROUP_SKB 2018-10-18 16:06 [PATCH v4 bpf-next 0/2] bpf: add cg_skb_is_valid_access Song Liu 2018-10-18 16:06 ` [PATCH v4 bpf-next 1/2] bpf: add cg_skb_is_valid_access for BPF_PROG_TYPE_CGROUP_SKB Song Liu @ 2018-10-18 16:06 ` Song Liu 2018-10-18 23:34 ` [PATCH v4 bpf-next 0/2] bpf: add cg_skb_is_valid_access Alexei Starovoitov 2 siblings, 0 replies; 8+ messages in thread From: Song Liu @ 2018-10-18 16:06 UTC (permalink / raw) To: netdev; +Cc: ast, daniel, kernel-team, Song Liu Tests are added to make sure CGROUP_SKB cannot access: tc_classid, data_meta, flow_keys and can read and write: mark, prority, and cb[0-4] and can read other fields. To make selftest with skb->sk work, a dummy sk is added in bpf_prog_test_run_skb(). Signed-off-by: Song Liu <songliubraving@fb.com> --- net/bpf/test_run.c | 7 + tools/testing/selftests/bpf/test_verifier.c | 170 ++++++++++++++++++++ 2 files changed, 177 insertions(+) diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index 0c423b8cd75c..8dccac305268 100644 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -10,6 +10,8 @@ #include <linux/etherdevice.h> #include <linux/filter.h> #include <linux/sched/signal.h> +#include <net/sock.h> +#include <net/tcp.h> static __always_inline u32 bpf_test_run_one(struct bpf_prog *prog, void *ctx, struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE]) @@ -115,6 +117,7 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr, u32 retval, duration; int hh_len = ETH_HLEN; struct sk_buff *skb; + struct sock sk = {0}; void *data; int ret; @@ -137,11 +140,15 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr, break; } + sock_net_set(&sk, &init_net); + sock_init_data(NULL, &sk); + skb = build_skb(data, 0); if (!skb) { kfree(data); return -ENOMEM; } + skb->sk = &sk; skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN); __skb_put(skb, size); diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index cf4cd32b6772..5bfba7e8afd7 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -4862,6 +4862,176 @@ static struct bpf_test tests[] = { .result = REJECT, .flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS, }, + { + "direct packet read test#1 for CGROUP_SKB", + .insns = { + BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, + offsetof(struct __sk_buff, data)), + BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1, + offsetof(struct __sk_buff, data_end)), + BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_1, + offsetof(struct __sk_buff, len)), + BPF_LDX_MEM(BPF_W, BPF_REG_5, BPF_REG_1, + offsetof(struct __sk_buff, pkt_type)), + BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1, + offsetof(struct __sk_buff, mark)), + BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_6, + offsetof(struct __sk_buff, mark)), + BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_1, + offsetof(struct __sk_buff, queue_mapping)), + BPF_LDX_MEM(BPF_W, BPF_REG_8, BPF_REG_1, + offsetof(struct __sk_buff, protocol)), + BPF_LDX_MEM(BPF_W, BPF_REG_9, BPF_REG_1, + offsetof(struct __sk_buff, vlan_present)), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_2), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8), + BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 1), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_2, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .prog_type = BPF_PROG_TYPE_CGROUP_SKB, + }, + { + "direct packet read test#2 for CGROUP_SKB", + .insns = { + BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_1, + offsetof(struct __sk_buff, vlan_tci)), + BPF_LDX_MEM(BPF_W, BPF_REG_5, BPF_REG_1, + offsetof(struct __sk_buff, vlan_proto)), + BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1, + offsetof(struct __sk_buff, priority)), + BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_6, + offsetof(struct __sk_buff, priority)), + BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_1, + offsetof(struct __sk_buff, ingress_ifindex)), + BPF_LDX_MEM(BPF_W, BPF_REG_8, BPF_REG_1, + offsetof(struct __sk_buff, tc_index)), + BPF_LDX_MEM(BPF_W, BPF_REG_9, BPF_REG_1, + offsetof(struct __sk_buff, hash)), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .prog_type = BPF_PROG_TYPE_CGROUP_SKB, + }, + { + "direct packet read test#3 for CGROUP_SKB", + .insns = { + BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_1, + offsetof(struct __sk_buff, cb[0])), + BPF_LDX_MEM(BPF_W, BPF_REG_5, BPF_REG_1, + offsetof(struct __sk_buff, cb[1])), + BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1, + offsetof(struct __sk_buff, cb[2])), + BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_1, + offsetof(struct __sk_buff, cb[3])), + BPF_LDX_MEM(BPF_W, BPF_REG_8, BPF_REG_1, + offsetof(struct __sk_buff, cb[4])), + BPF_LDX_MEM(BPF_W, BPF_REG_9, BPF_REG_1, + offsetof(struct __sk_buff, napi_id)), + BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_4, + offsetof(struct __sk_buff, cb[0])), + BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_5, + offsetof(struct __sk_buff, cb[1])), + BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_6, + offsetof(struct __sk_buff, cb[2])), + BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_7, + offsetof(struct __sk_buff, cb[3])), + BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_8, + offsetof(struct __sk_buff, cb[4])), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .prog_type = BPF_PROG_TYPE_CGROUP_SKB, + }, + { + "direct packet read test#4 for CGROUP_SKB", + .insns = { + BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, + offsetof(struct __sk_buff, family)), + BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1, + offsetof(struct __sk_buff, remote_ip4)), + BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_1, + offsetof(struct __sk_buff, local_ip4)), + BPF_LDX_MEM(BPF_W, BPF_REG_5, BPF_REG_1, + offsetof(struct __sk_buff, remote_ip6[0])), + BPF_LDX_MEM(BPF_W, BPF_REG_5, BPF_REG_1, + offsetof(struct __sk_buff, remote_ip6[1])), + BPF_LDX_MEM(BPF_W, BPF_REG_5, BPF_REG_1, + offsetof(struct __sk_buff, remote_ip6[2])), + BPF_LDX_MEM(BPF_W, BPF_REG_5, BPF_REG_1, + offsetof(struct __sk_buff, remote_ip6[3])), + BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1, + offsetof(struct __sk_buff, local_ip6[0])), + BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1, + offsetof(struct __sk_buff, local_ip6[1])), + BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1, + offsetof(struct __sk_buff, local_ip6[2])), + BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1, + offsetof(struct __sk_buff, local_ip6[3])), + BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_1, + offsetof(struct __sk_buff, remote_port)), + BPF_LDX_MEM(BPF_W, BPF_REG_8, BPF_REG_1, + offsetof(struct __sk_buff, local_port)), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .prog_type = BPF_PROG_TYPE_CGROUP_SKB, + }, + { + "invalid access of tc_classid for CGROUP_SKB", + .insns = { + BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, tc_classid)), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .result = REJECT, + .errstr = "invalid bpf_context access", + .prog_type = BPF_PROG_TYPE_CGROUP_SKB, + }, + { + "invalid access of data_meta for CGROUP_SKB", + .insns = { + BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, data_meta)), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .result = REJECT, + .errstr = "invalid bpf_context access", + .prog_type = BPF_PROG_TYPE_CGROUP_SKB, + }, + { + "invalid access of flow_keys for CGROUP_SKB", + .insns = { + BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, + offsetof(struct __sk_buff, flow_keys)), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .result = REJECT, + .errstr = "invalid bpf_context access", + .prog_type = BPF_PROG_TYPE_CGROUP_SKB, + }, + { + "invalid write access to napi_id for CGROUP_SKB", + .insns = { + BPF_LDX_MEM(BPF_W, BPF_REG_9, BPF_REG_1, + offsetof(struct __sk_buff, napi_id)), + BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_9, + offsetof(struct __sk_buff, napi_id)), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .result = REJECT, + .errstr = "invalid bpf_context access", + .prog_type = BPF_PROG_TYPE_CGROUP_SKB, + }, { "valid cgroup storage access", .insns = { -- 2.17.1 ^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH v4 bpf-next 0/2] bpf: add cg_skb_is_valid_access 2018-10-18 16:06 [PATCH v4 bpf-next 0/2] bpf: add cg_skb_is_valid_access Song Liu 2018-10-18 16:06 ` [PATCH v4 bpf-next 1/2] bpf: add cg_skb_is_valid_access for BPF_PROG_TYPE_CGROUP_SKB Song Liu 2018-10-18 16:06 ` [PATCH v4 bpf-next 2/2] bpf: add tests for direct packet access from CGROUP_SKB Song Liu @ 2018-10-18 23:34 ` Alexei Starovoitov 2018-10-19 1:46 ` Alexei Starovoitov 2 siblings, 1 reply; 8+ messages in thread From: Alexei Starovoitov @ 2018-10-18 23:34 UTC (permalink / raw) To: Song Liu; +Cc: netdev, ast, daniel, kernel-team On Thu, Oct 18, 2018 at 09:06:47AM -0700, Song Liu wrote: > Changes v3 -> v4: > 1. Fixed crash issue reported by Alexei. > > Changes v2 -> v3: > 1. Added helper function bpf_compute_and_save_data_pointers() and > bpf_restore_data_pointers(). > > Changes v1 -> v2: > 1. Updated the list of read-only fields, and read-write fields. > 2. Added dummy sk to bpf_prog_test_run_skb(). > > This set enables BPF program of type BPF_PROG_TYPE_CGROUP_SKB to access > some __skb_buff data directly. Applied, Thanks ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v4 bpf-next 0/2] bpf: add cg_skb_is_valid_access 2018-10-18 23:34 ` [PATCH v4 bpf-next 0/2] bpf: add cg_skb_is_valid_access Alexei Starovoitov @ 2018-10-19 1:46 ` Alexei Starovoitov 0 siblings, 0 replies; 8+ messages in thread From: Alexei Starovoitov @ 2018-10-19 1:46 UTC (permalink / raw) To: Alexei Starovoitov, Song Liu Cc: netdev@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net, Kernel Team On 10/18/18 4:34 PM, Alexei Starovoitov wrote: > On Thu, Oct 18, 2018 at 09:06:47AM -0700, Song Liu wrote: >> Changes v3 -> v4: >> 1. Fixed crash issue reported by Alexei. >> >> Changes v2 -> v3: >> 1. Added helper function bpf_compute_and_save_data_pointers() and >> bpf_restore_data_pointers(). >> >> Changes v1 -> v2: >> 1. Updated the list of read-only fields, and read-write fields. >> 2. Added dummy sk to bpf_prog_test_run_skb(). >> >> This set enables BPF program of type BPF_PROG_TYPE_CGROUP_SKB to access >> some __skb_buff data directly. > > Applied, Thanks Daniel brought up good point re: data_meta. Let's address it one way or the other and respin the series instead of adding follow up patches. So I tossed this series out of bpf-next. ^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2018-10-19 10:07 UTC | newest] Thread overview: 8+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2018-10-18 16:06 [PATCH v4 bpf-next 0/2] bpf: add cg_skb_is_valid_access Song Liu 2018-10-18 16:06 ` [PATCH v4 bpf-next 1/2] bpf: add cg_skb_is_valid_access for BPF_PROG_TYPE_CGROUP_SKB Song Liu 2018-10-19 0:14 ` Daniel Borkmann 2018-10-19 1:33 ` Alexei Starovoitov 2018-10-19 2:03 ` Alexei Starovoitov 2018-10-18 16:06 ` [PATCH v4 bpf-next 2/2] bpf: add tests for direct packet access from CGROUP_SKB Song Liu 2018-10-18 23:34 ` [PATCH v4 bpf-next 0/2] bpf: add cg_skb_is_valid_access Alexei Starovoitov 2018-10-19 1:46 ` Alexei Starovoitov
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