| Message ID | 2443b6093691c7ae9dace98b0257f61ff2ff30ec.1700676682.git.dxu@dxuuu.xyz (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | Add bpf_xdp_get_xfrm_state() kfunc | expand |
On Wed, Nov 22, 2023 at 10:21 AM Daniel Xu <dxu@dxuuu.xyz> wrote: > > + > +__diag_push(); > +__diag_ignore_all("-Wmissing-prototypes", > + "Global functions as their definitions will be in xfrm_state BTF"); Pls use __bpf_kfunc_start_defs() instead.
On 11/22/23 1:20 PM, Daniel Xu wrote: > This commit adds an unstable kfunc helper to access internal xfrm_state > associated with an SA. This is intended to be used for the upcoming > IPsec pcpu work to assign special pcpu SAs to a particular CPU. In other > words: for custom software RSS. > > That being said, the function that this kfunc wraps is fairly generic > and used for a lot of xfrm tasks. I'm sure people will find uses > elsewhere over time. > > Co-developed-by: Antony Antony <antony.antony@secunet.com> > Signed-off-by: Antony Antony <antony.antony@secunet.com> > Signed-off-by: Daniel Xu <dxu@dxuuu.xyz> > --- > include/net/xfrm.h | 9 ++++ > net/xfrm/Makefile | 1 + > net/xfrm/xfrm_policy.c | 2 + > net/xfrm/xfrm_state_bpf.c | 111 ++++++++++++++++++++++++++++++++++++++ > 4 files changed, 123 insertions(+) > create mode 100644 net/xfrm/xfrm_state_bpf.c > > diff --git a/include/net/xfrm.h b/include/net/xfrm.h > index c9bb0f892f55..1d107241b901 100644 > --- a/include/net/xfrm.h > +++ b/include/net/xfrm.h > @@ -2190,4 +2190,13 @@ static inline int register_xfrm_interface_bpf(void) > > #endif > > +#if IS_ENABLED(CONFIG_DEBUG_INFO_BTF) > +int register_xfrm_state_bpf(void); > +#else > +static inline int register_xfrm_state_bpf(void) > +{ > + return 0; > +} > +#endif > + > #endif /* _NET_XFRM_H */ > diff --git a/net/xfrm/Makefile b/net/xfrm/Makefile > index cd47f88921f5..547cec77ba03 100644 > --- a/net/xfrm/Makefile > +++ b/net/xfrm/Makefile > @@ -21,3 +21,4 @@ obj-$(CONFIG_XFRM_USER_COMPAT) += xfrm_compat.o > obj-$(CONFIG_XFRM_IPCOMP) += xfrm_ipcomp.o > obj-$(CONFIG_XFRM_INTERFACE) += xfrm_interface.o > obj-$(CONFIG_XFRM_ESPINTCP) += espintcp.o > +obj-$(CONFIG_DEBUG_INFO_BTF) += xfrm_state_bpf.o > diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c > index c13dc3ef7910..1b7e75159727 100644 > --- a/net/xfrm/xfrm_policy.c > +++ b/net/xfrm/xfrm_policy.c > @@ -4218,6 +4218,8 @@ void __init xfrm_init(void) > #ifdef CONFIG_XFRM_ESPINTCP > espintcp_init(); > #endif > + > + register_xfrm_state_bpf(); > } > > #ifdef CONFIG_AUDITSYSCALL > diff --git a/net/xfrm/xfrm_state_bpf.c b/net/xfrm/xfrm_state_bpf.c > new file mode 100644 > index 000000000000..0c1f2f91125c > --- /dev/null > +++ b/net/xfrm/xfrm_state_bpf.c > @@ -0,0 +1,111 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* Unstable XFRM state BPF helpers. > + * > + * Note that it is allowed to break compatibility for these functions since the > + * interface they are exposed through to BPF programs is explicitly unstable. > + */ > + > +#include <linux/bpf.h> > +#include <linux/btf_ids.h> > +#include <net/xdp.h> > +#include <net/xfrm.h> > + > +/* bpf_xfrm_state_opts - Options for XFRM state lookup helpers > + * > + * Members: > + * @error - Out parameter, set for any errors encountered > + * Values: > + * -EINVAL - netns_id is less than -1 > + * -EINVAL - Passed NULL for opts > + * -EINVAL - opts__sz isn't BPF_XFRM_STATE_OPTS_SZ > + * -ENONET - No network namespace found for netns_id > + * @netns_id - Specify the network namespace for lookup > + * Values: > + * BPF_F_CURRENT_NETNS (-1) > + * Use namespace associated with ctx > + * [0, S32_MAX] > + * Network Namespace ID > + * @mark - XFRM mark to match on > + * @daddr - Destination address to match on > + * @spi - Security parameter index to match on > + * @proto - L3 protocol to match on > + * @family - L3 protocol family to match on > + */ > +struct bpf_xfrm_state_opts { > + s32 error; > + s32 netns_id; > + u32 mark; > + xfrm_address_t daddr; > + __be32 spi; > + u8 proto; > + u16 family; > +}; > + > +enum { > + BPF_XFRM_STATE_OPTS_SZ = sizeof(struct bpf_xfrm_state_opts), > +}; > + > +__diag_push(); > +__diag_ignore_all("-Wmissing-prototypes", > + "Global functions as their definitions will be in xfrm_state BTF"); > + > +/* bpf_xdp_get_xfrm_state - Get XFRM state > + * > + * Parameters: > + * @ctx - Pointer to ctx (xdp_md) in XDP program > + * Cannot be NULL > + * @opts - Options for lookup (documented above) > + * Cannot be NULL > + * @opts__sz - Length of the bpf_xfrm_state_opts structure > + * Must be BPF_XFRM_STATE_OPTS_SZ > + */ > +__bpf_kfunc struct xfrm_state * > +bpf_xdp_get_xfrm_state(struct xdp_md *ctx, struct bpf_xfrm_state_opts *opts, u32 opts__sz) > +{ > + struct xdp_buff *xdp = (struct xdp_buff *)ctx; > + struct net *net = dev_net(xdp->rxq->dev); > + struct xfrm_state *x; > + > + if (!opts || opts__sz != BPF_XFRM_STATE_OPTS_SZ) { > + opts->error = -EINVAL; If opts is NULL, obvious we have issue opts->error access. If opts is not NULL and opts_sz < 4, we also have issue with opts->error access since it may override some other stuff on the stack. In such cases, we do not need to do 'opts->error = -EINVAL' and can simply 'return NULL'. bpf program won't be able to check opts->error anyway since the opts is either NULL or opts_sz < 4. > + return NULL; > + } > + > + if (unlikely(opts->netns_id < BPF_F_CURRENT_NETNS)) { > + opts->error = -EINVAL; > + return NULL; > + } > + > + if (opts->netns_id >= 0) { > + net = get_net_ns_by_id(net, opts->netns_id); > + if (unlikely(!net)) { > + opts->error = -ENONET; > + return NULL; > + } > + } > + > + x = xfrm_state_lookup(net, opts->mark, &opts->daddr, opts->spi, > + opts->proto, opts->family); > + > + if (opts->netns_id >= 0) > + put_net(net); > + > + return x; > +} > + > +__diag_pop() [...]
On Sat, Nov 25, 2023 at 12:36:29PM -0800, Yonghong Song wrote: > > On 11/22/23 1:20 PM, Daniel Xu wrote: > > This commit adds an unstable kfunc helper to access internal xfrm_state > > associated with an SA. This is intended to be used for the upcoming > > IPsec pcpu work to assign special pcpu SAs to a particular CPU. In other > > words: for custom software RSS. > > > > That being said, the function that this kfunc wraps is fairly generic > > and used for a lot of xfrm tasks. I'm sure people will find uses > > elsewhere over time. > > > > Co-developed-by: Antony Antony <antony.antony@secunet.com> > > Signed-off-by: Antony Antony <antony.antony@secunet.com> > > Signed-off-by: Daniel Xu <dxu@dxuuu.xyz> > > --- > > include/net/xfrm.h | 9 ++++ > > net/xfrm/Makefile | 1 + > > net/xfrm/xfrm_policy.c | 2 + > > net/xfrm/xfrm_state_bpf.c | 111 ++++++++++++++++++++++++++++++++++++++ > > 4 files changed, 123 insertions(+) > > create mode 100644 net/xfrm/xfrm_state_bpf.c > > > > diff --git a/include/net/xfrm.h b/include/net/xfrm.h > > index c9bb0f892f55..1d107241b901 100644 > > --- a/include/net/xfrm.h > > +++ b/include/net/xfrm.h > > @@ -2190,4 +2190,13 @@ static inline int register_xfrm_interface_bpf(void) > > #endif > > +#if IS_ENABLED(CONFIG_DEBUG_INFO_BTF) > > +int register_xfrm_state_bpf(void); > > +#else > > +static inline int register_xfrm_state_bpf(void) > > +{ > > + return 0; > > +} > > +#endif > > + > > #endif /* _NET_XFRM_H */ > > diff --git a/net/xfrm/Makefile b/net/xfrm/Makefile > > index cd47f88921f5..547cec77ba03 100644 > > --- a/net/xfrm/Makefile > > +++ b/net/xfrm/Makefile > > @@ -21,3 +21,4 @@ obj-$(CONFIG_XFRM_USER_COMPAT) += xfrm_compat.o > > obj-$(CONFIG_XFRM_IPCOMP) += xfrm_ipcomp.o > > obj-$(CONFIG_XFRM_INTERFACE) += xfrm_interface.o > > obj-$(CONFIG_XFRM_ESPINTCP) += espintcp.o > > +obj-$(CONFIG_DEBUG_INFO_BTF) += xfrm_state_bpf.o > > diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c > > index c13dc3ef7910..1b7e75159727 100644 > > --- a/net/xfrm/xfrm_policy.c > > +++ b/net/xfrm/xfrm_policy.c > > @@ -4218,6 +4218,8 @@ void __init xfrm_init(void) > > #ifdef CONFIG_XFRM_ESPINTCP > > espintcp_init(); > > #endif > > + > > + register_xfrm_state_bpf(); > > } > > #ifdef CONFIG_AUDITSYSCALL > > diff --git a/net/xfrm/xfrm_state_bpf.c b/net/xfrm/xfrm_state_bpf.c > > new file mode 100644 > > index 000000000000..0c1f2f91125c > > --- /dev/null > > +++ b/net/xfrm/xfrm_state_bpf.c > > @@ -0,0 +1,111 @@ > > +// SPDX-License-Identifier: GPL-2.0-only > > +/* Unstable XFRM state BPF helpers. > > + * > > + * Note that it is allowed to break compatibility for these functions since the > > + * interface they are exposed through to BPF programs is explicitly unstable. > > + */ > > + > > +#include <linux/bpf.h> > > +#include <linux/btf_ids.h> > > +#include <net/xdp.h> > > +#include <net/xfrm.h> > > + > > +/* bpf_xfrm_state_opts - Options for XFRM state lookup helpers > > + * > > + * Members: > > + * @error - Out parameter, set for any errors encountered > > + * Values: > > + * -EINVAL - netns_id is less than -1 > > + * -EINVAL - Passed NULL for opts > > + * -EINVAL - opts__sz isn't BPF_XFRM_STATE_OPTS_SZ > > + * -ENONET - No network namespace found for netns_id > > + * @netns_id - Specify the network namespace for lookup > > + * Values: > > + * BPF_F_CURRENT_NETNS (-1) > > + * Use namespace associated with ctx > > + * [0, S32_MAX] > > + * Network Namespace ID > > + * @mark - XFRM mark to match on > > + * @daddr - Destination address to match on > > + * @spi - Security parameter index to match on > > + * @proto - L3 protocol to match on > > + * @family - L3 protocol family to match on > > + */ > > +struct bpf_xfrm_state_opts { > > + s32 error; > > + s32 netns_id; > > + u32 mark; > > + xfrm_address_t daddr; > > + __be32 spi; > > + u8 proto; > > + u16 family; > > +}; > > + > > +enum { > > + BPF_XFRM_STATE_OPTS_SZ = sizeof(struct bpf_xfrm_state_opts), > > +}; > > + > > +__diag_push(); > > +__diag_ignore_all("-Wmissing-prototypes", > > + "Global functions as their definitions will be in xfrm_state BTF"); > > + > > +/* bpf_xdp_get_xfrm_state - Get XFRM state > > + * > > + * Parameters: > > + * @ctx - Pointer to ctx (xdp_md) in XDP program > > + * Cannot be NULL > > + * @opts - Options for lookup (documented above) > > + * Cannot be NULL > > + * @opts__sz - Length of the bpf_xfrm_state_opts structure > > + * Must be BPF_XFRM_STATE_OPTS_SZ > > + */ > > +__bpf_kfunc struct xfrm_state * > > +bpf_xdp_get_xfrm_state(struct xdp_md *ctx, struct bpf_xfrm_state_opts *opts, u32 opts__sz) > > +{ > > + struct xdp_buff *xdp = (struct xdp_buff *)ctx; > > + struct net *net = dev_net(xdp->rxq->dev); > > + struct xfrm_state *x; > > + > > + if (!opts || opts__sz != BPF_XFRM_STATE_OPTS_SZ) { > > + opts->error = -EINVAL; > > If opts is NULL, obvious we have issue opts->error access. > If opts is not NULL and opts_sz < 4, we also have issue with > opts->error access since it may override some other stuff > on the stack. > > In such cases, we do not need to do 'opts->error = -EINVAL' > and can simply 'return NULL'. bpf program won't be able > to check opts->error anyway since the opts is either NULL > or opts_sz < 4. Ack, will fix. [...] Thanks, Daniel
diff --git a/include/net/xfrm.h b/include/net/xfrm.h index c9bb0f892f55..1d107241b901 100644 --- a/include/net/xfrm.h +++ b/include/net/xfrm.h @@ -2190,4 +2190,13 @@ static inline int register_xfrm_interface_bpf(void) #endif +#if IS_ENABLED(CONFIG_DEBUG_INFO_BTF) +int register_xfrm_state_bpf(void); +#else +static inline int register_xfrm_state_bpf(void) +{ + return 0; +} +#endif + #endif /* _NET_XFRM_H */ diff --git a/net/xfrm/Makefile b/net/xfrm/Makefile index cd47f88921f5..547cec77ba03 100644 --- a/net/xfrm/Makefile +++ b/net/xfrm/Makefile @@ -21,3 +21,4 @@ obj-$(CONFIG_XFRM_USER_COMPAT) += xfrm_compat.o obj-$(CONFIG_XFRM_IPCOMP) += xfrm_ipcomp.o obj-$(CONFIG_XFRM_INTERFACE) += xfrm_interface.o obj-$(CONFIG_XFRM_ESPINTCP) += espintcp.o +obj-$(CONFIG_DEBUG_INFO_BTF) += xfrm_state_bpf.o diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c index c13dc3ef7910..1b7e75159727 100644 --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -4218,6 +4218,8 @@ void __init xfrm_init(void) #ifdef CONFIG_XFRM_ESPINTCP espintcp_init(); #endif + + register_xfrm_state_bpf(); } #ifdef CONFIG_AUDITSYSCALL diff --git a/net/xfrm/xfrm_state_bpf.c b/net/xfrm/xfrm_state_bpf.c new file mode 100644 index 000000000000..0c1f2f91125c --- /dev/null +++ b/net/xfrm/xfrm_state_bpf.c @@ -0,0 +1,111 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Unstable XFRM state BPF helpers. + * + * Note that it is allowed to break compatibility for these functions since the + * interface they are exposed through to BPF programs is explicitly unstable. + */ + +#include <linux/bpf.h> +#include <linux/btf_ids.h> +#include <net/xdp.h> +#include <net/xfrm.h> + +/* bpf_xfrm_state_opts - Options for XFRM state lookup helpers + * + * Members: + * @error - Out parameter, set for any errors encountered + * Values: + * -EINVAL - netns_id is less than -1 + * -EINVAL - Passed NULL for opts + * -EINVAL - opts__sz isn't BPF_XFRM_STATE_OPTS_SZ + * -ENONET - No network namespace found for netns_id + * @netns_id - Specify the network namespace for lookup + * Values: + * BPF_F_CURRENT_NETNS (-1) + * Use namespace associated with ctx + * [0, S32_MAX] + * Network Namespace ID + * @mark - XFRM mark to match on + * @daddr - Destination address to match on + * @spi - Security parameter index to match on + * @proto - L3 protocol to match on + * @family - L3 protocol family to match on + */ +struct bpf_xfrm_state_opts { + s32 error; + s32 netns_id; + u32 mark; + xfrm_address_t daddr; + __be32 spi; + u8 proto; + u16 family; +}; + +enum { + BPF_XFRM_STATE_OPTS_SZ = sizeof(struct bpf_xfrm_state_opts), +}; + +__diag_push(); +__diag_ignore_all("-Wmissing-prototypes", + "Global functions as their definitions will be in xfrm_state BTF"); + +/* bpf_xdp_get_xfrm_state - Get XFRM state + * + * Parameters: + * @ctx - Pointer to ctx (xdp_md) in XDP program + * Cannot be NULL + * @opts - Options for lookup (documented above) + * Cannot be NULL + * @opts__sz - Length of the bpf_xfrm_state_opts structure + * Must be BPF_XFRM_STATE_OPTS_SZ + */ +__bpf_kfunc struct xfrm_state * +bpf_xdp_get_xfrm_state(struct xdp_md *ctx, struct bpf_xfrm_state_opts *opts, u32 opts__sz) +{ + struct xdp_buff *xdp = (struct xdp_buff *)ctx; + struct net *net = dev_net(xdp->rxq->dev); + struct xfrm_state *x; + + if (!opts || opts__sz != BPF_XFRM_STATE_OPTS_SZ) { + opts->error = -EINVAL; + return NULL; + } + + if (unlikely(opts->netns_id < BPF_F_CURRENT_NETNS)) { + opts->error = -EINVAL; + return NULL; + } + + if (opts->netns_id >= 0) { + net = get_net_ns_by_id(net, opts->netns_id); + if (unlikely(!net)) { + opts->error = -ENONET; + return NULL; + } + } + + x = xfrm_state_lookup(net, opts->mark, &opts->daddr, opts->spi, + opts->proto, opts->family); + + if (opts->netns_id >= 0) + put_net(net); + + return x; +} + +__diag_pop() + +BTF_SET8_START(xfrm_state_kfunc_set) +BTF_ID_FLAGS(func, bpf_xdp_get_xfrm_state, KF_RET_NULL | KF_ACQUIRE) +BTF_SET8_END(xfrm_state_kfunc_set) + +static const struct btf_kfunc_id_set xfrm_state_xdp_kfunc_set = { + .owner = THIS_MODULE, + .set = &xfrm_state_kfunc_set, +}; + +int __init register_xfrm_state_bpf(void) +{ + return register_btf_kfunc_id_set(BPF_PROG_TYPE_XDP, + &xfrm_state_xdp_kfunc_set); +}