From 97a0e1ea7b41c2db762c1258632f6ccc22719510 Mon Sep 17 00:00:00 2001 From: Lorenzo Bianconi Date: Tue, 12 Jan 2021 19:26:12 +0100 Subject: net, xdp: Introduce __xdp_build_skb_from_frame utility routine Introduce __xdp_build_skb_from_frame utility routine to build the skb from xdp_frame. Rely on __xdp_build_skb_from_frame in cpumap code. Signed-off-by: Lorenzo Bianconi Signed-off-by: Daniel Borkmann Acked-by: Jesper Dangaard Brouer Link: https://lore.kernel.org/bpf/4f9f4c6b3dd3933770c617eb6689dbc0c6e25863.1610475660.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov --- net/core/xdp.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) (limited to 'net') diff --git a/net/core/xdp.c b/net/core/xdp.c index 3a8c9ab4ecbe..aeb09ed0704c 100644 --- a/net/core/xdp.c +++ b/net/core/xdp.c @@ -513,3 +513,47 @@ void xdp_warn(const char *msg, const char *func, const int line) WARN(1, "XDP_WARN: %s(line:%d): %s\n", func, line, msg); }; EXPORT_SYMBOL_GPL(xdp_warn); + +struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf, + struct sk_buff *skb, + struct net_device *dev) +{ + unsigned int headroom, frame_size; + void *hard_start; + + /* Part of headroom was reserved to xdpf */ + headroom = sizeof(*xdpf) + xdpf->headroom; + + /* Memory size backing xdp_frame data already have reserved + * room for build_skb to place skb_shared_info in tailroom. + */ + frame_size = xdpf->frame_sz; + + hard_start = xdpf->data - headroom; + skb = build_skb_around(skb, hard_start, frame_size); + if (unlikely(!skb)) + return NULL; + + skb_reserve(skb, headroom); + __skb_put(skb, xdpf->len); + if (xdpf->metasize) + skb_metadata_set(skb, xdpf->metasize); + + /* Essential SKB info: protocol and skb->dev */ + skb->protocol = eth_type_trans(skb, dev); + + /* Optional SKB info, currently missing: + * - HW checksum info (skb->ip_summed) + * - HW RX hash (skb_set_hash) + * - RX ring dev queue index (skb_record_rx_queue) + */ + + /* Until page_pool get SKB return path, release DMA here */ + xdp_release_frame(xdpf); + + /* Allow SKB to reuse area used by xdp_frame */ + xdp_scrub_frame(xdpf); + + return skb; +} +EXPORT_SYMBOL_GPL(__xdp_build_skb_from_frame); -- cgit v1.2.3 From 89f479f0eccfc879e7bc0a69f44ed4a4639dfc32 Mon Sep 17 00:00:00 2001 From: Lorenzo Bianconi Date: Tue, 12 Jan 2021 19:26:13 +0100 Subject: net, xdp: Introduce xdp_build_skb_from_frame utility routine Introduce xdp_build_skb_from_frame utility routine to build the skb from xdp_frame. Respect to __xdp_build_skb_from_frame, xdp_build_skb_from_frame will allocate the skb object. Rely on xdp_build_skb_from_frame in veth driver. Introduce missing xdp metadata support in veth_xdp_rcv_one routine. Add missing metadata support in veth_xdp_rcv_one(). Signed-off-by: Lorenzo Bianconi Signed-off-by: Daniel Borkmann Reviewed-by: Toshiaki Makita Acked-by: Jesper Dangaard Brouer Link: https://lore.kernel.org/bpf/94ade9e853162ae1947941965193190da97457bc.1610475660.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov --- drivers/net/veth.c | 18 +++--------------- include/net/xdp.h | 2 ++ net/core/xdp.c | 15 +++++++++++++++ 3 files changed, 20 insertions(+), 15 deletions(-) (limited to 'net') diff --git a/drivers/net/veth.c b/drivers/net/veth.c index 99caae7d1641..6e03b619c93c 100644 --- a/drivers/net/veth.c +++ b/drivers/net/veth.c @@ -567,16 +567,10 @@ static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq, struct veth_xdp_tx_bq *bq, struct veth_stats *stats) { - void *hard_start = frame->data - frame->headroom; - int len = frame->len, delta = 0; struct xdp_frame orig_frame; struct bpf_prog *xdp_prog; - unsigned int headroom; struct sk_buff *skb; - /* bpf_xdp_adjust_head() assures BPF cannot access xdp_frame area */ - hard_start -= sizeof(struct xdp_frame); - rcu_read_lock(); xdp_prog = rcu_dereference(rq->xdp_prog); if (likely(xdp_prog)) { @@ -590,8 +584,8 @@ static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq, switch (act) { case XDP_PASS: - delta = frame->data - xdp.data; - len = xdp.data_end - xdp.data; + if (xdp_update_frame_from_buff(&xdp, frame)) + goto err_xdp; break; case XDP_TX: orig_frame = *frame; @@ -629,18 +623,12 @@ static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq, } rcu_read_unlock(); - headroom = sizeof(struct xdp_frame) + frame->headroom - delta; - skb = veth_build_skb(hard_start, headroom, len, frame->frame_sz); + skb = xdp_build_skb_from_frame(frame, rq->dev); if (!skb) { xdp_return_frame(frame); stats->rx_drops++; - goto err; } - xdp_release_frame(frame); - xdp_scrub_frame(frame); - skb->protocol = eth_type_trans(skb, rq->dev); -err: return skb; err_xdp: rcu_read_unlock(); diff --git a/include/net/xdp.h b/include/net/xdp.h index 689206dee6de..c4bfdc9a8b79 100644 --- a/include/net/xdp.h +++ b/include/net/xdp.h @@ -167,6 +167,8 @@ struct xdp_frame *xdp_convert_zc_to_xdp_frame(struct xdp_buff *xdp); struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf, struct sk_buff *skb, struct net_device *dev); +struct sk_buff *xdp_build_skb_from_frame(struct xdp_frame *xdpf, + struct net_device *dev); static inline void xdp_convert_frame_to_buff(struct xdp_frame *frame, struct xdp_buff *xdp) diff --git a/net/core/xdp.c b/net/core/xdp.c index aeb09ed0704c..0d2630a35c3e 100644 --- a/net/core/xdp.c +++ b/net/core/xdp.c @@ -557,3 +557,18 @@ struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf, return skb; } EXPORT_SYMBOL_GPL(__xdp_build_skb_from_frame); + +struct sk_buff *xdp_build_skb_from_frame(struct xdp_frame *xdpf, + struct net_device *dev) +{ + struct sk_buff *skb; + + skb = kmem_cache_alloc(skbuff_head_cache, GFP_ATOMIC); + if (unlikely(!skb)) + return NULL; + + memset(skb, 0, offsetof(struct sk_buff, tail)); + + return __xdp_build_skb_from_frame(xdpf, skb, dev); +} +EXPORT_SYMBOL_GPL(xdp_build_skb_from_frame); -- cgit v1.2.3 From 9cacf81f8161111db25f98e78a7a0e32ae142b3f Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Fri, 15 Jan 2021 08:34:59 -0800 Subject: bpf: Remove extra lock_sock for TCP_ZEROCOPY_RECEIVE Add custom implementation of getsockopt hook for TCP_ZEROCOPY_RECEIVE. We skip generic hooks for TCP_ZEROCOPY_RECEIVE and have a custom call in do_tcp_getsockopt using the on-stack data. This removes 3% overhead for locking/unlocking the socket. Without this patch: 3.38% 0.07% tcp_mmap [kernel.kallsyms] [k] __cgroup_bpf_run_filter_getsockopt | --3.30%--__cgroup_bpf_run_filter_getsockopt | --0.81%--__kmalloc With the patch applied: 0.52% 0.12% tcp_mmap [kernel.kallsyms] [k] __cgroup_bpf_run_filter_getsockopt_kern Note, exporting uapi/tcp.h requires removing netinet/tcp.h from test_progs.h because those headers have confliciting definitions. Signed-off-by: Stanislav Fomichev Signed-off-by: Alexei Starovoitov Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/20210115163501.805133-2-sdf@google.com --- include/linux/bpf-cgroup.h | 27 +- include/linux/indirect_call_wrapper.h | 6 + include/net/sock.h | 2 + include/net/tcp.h | 1 + kernel/bpf/cgroup.c | 46 +++ net/ipv4/tcp.c | 14 + net/ipv4/tcp_ipv4.c | 1 + net/ipv6/tcp_ipv6.c | 1 + net/socket.c | 3 + tools/include/uapi/linux/tcp.h | 357 +++++++++++++++++++++ .../testing/selftests/bpf/prog_tests/bpf_tcp_ca.c | 1 + .../selftests/bpf/prog_tests/cls_redirect.c | 1 + .../selftests/bpf/prog_tests/sockmap_basic.c | 1 + .../testing/selftests/bpf/prog_tests/sockopt_sk.c | 28 ++ tools/testing/selftests/bpf/progs/sockopt_sk.c | 23 +- tools/testing/selftests/bpf/test_progs.h | 1 - 16 files changed, 506 insertions(+), 7 deletions(-) create mode 100644 tools/include/uapi/linux/tcp.h (limited to 'net') diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h index 72e69a0e1e8c..bcb2915e6124 100644 --- a/include/linux/bpf-cgroup.h +++ b/include/linux/bpf-cgroup.h @@ -147,6 +147,10 @@ int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level, int __user *optlen, int max_optlen, int retval); +int __cgroup_bpf_run_filter_getsockopt_kern(struct sock *sk, int level, + int optname, void *optval, + int *optlen, int retval); + static inline enum bpf_cgroup_storage_type cgroup_storage_type( struct bpf_map *map) { @@ -364,10 +368,23 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, ({ \ int __ret = retval; \ if (cgroup_bpf_enabled) \ - __ret = __cgroup_bpf_run_filter_getsockopt(sock, level, \ - optname, optval, \ - optlen, max_optlen, \ - retval); \ + if (!(sock)->sk_prot->bpf_bypass_getsockopt || \ + !INDIRECT_CALL_INET_1((sock)->sk_prot->bpf_bypass_getsockopt, \ + tcp_bpf_bypass_getsockopt, \ + level, optname)) \ + __ret = __cgroup_bpf_run_filter_getsockopt( \ + sock, level, optname, optval, optlen, \ + max_optlen, retval); \ + __ret; \ +}) + +#define BPF_CGROUP_RUN_PROG_GETSOCKOPT_KERN(sock, level, optname, optval, \ + optlen, retval) \ +({ \ + int __ret = retval; \ + if (cgroup_bpf_enabled) \ + __ret = __cgroup_bpf_run_filter_getsockopt_kern( \ + sock, level, optname, optval, optlen, retval); \ __ret; \ }) @@ -452,6 +469,8 @@ static inline int bpf_percpu_cgroup_storage_update(struct bpf_map *map, #define BPF_CGROUP_GETSOCKOPT_MAX_OPTLEN(optlen) ({ 0; }) #define BPF_CGROUP_RUN_PROG_GETSOCKOPT(sock, level, optname, optval, \ optlen, max_optlen, retval) ({ retval; }) +#define BPF_CGROUP_RUN_PROG_GETSOCKOPT_KERN(sock, level, optname, optval, \ + optlen, retval) ({ retval; }) #define BPF_CGROUP_RUN_PROG_SETSOCKOPT(sock, level, optname, optval, optlen, \ kernel_optval) ({ 0; }) diff --git a/include/linux/indirect_call_wrapper.h b/include/linux/indirect_call_wrapper.h index 54c02c84906a..cfcfef37b2f1 100644 --- a/include/linux/indirect_call_wrapper.h +++ b/include/linux/indirect_call_wrapper.h @@ -60,4 +60,10 @@ #define INDIRECT_CALL_INET(f, f2, f1, ...) f(__VA_ARGS__) #endif +#if IS_ENABLED(CONFIG_INET) +#define INDIRECT_CALL_INET_1(f, f1, ...) INDIRECT_CALL_1(f, f1, __VA_ARGS__) +#else +#define INDIRECT_CALL_INET_1(f, f1, ...) f(__VA_ARGS__) +#endif + #endif diff --git a/include/net/sock.h b/include/net/sock.h index 129d200bccb4..7644ea64a376 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1174,6 +1174,8 @@ struct proto { int (*backlog_rcv) (struct sock *sk, struct sk_buff *skb); + bool (*bpf_bypass_getsockopt)(int level, + int optname); void (*release_cb)(struct sock *sk); diff --git a/include/net/tcp.h b/include/net/tcp.h index 78d13c88720f..4bb42fb19711 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -403,6 +403,7 @@ __poll_t tcp_poll(struct file *file, struct socket *sock, struct poll_table_struct *wait); int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen); +bool tcp_bpf_bypass_getsockopt(int level, int optname); int tcp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, unsigned int optlen); void tcp_set_keepalive(struct sock *sk, int val); diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index 96555a8a2c54..416e7738981b 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -1486,6 +1486,52 @@ out: sockopt_free_buf(&ctx); return ret; } + +int __cgroup_bpf_run_filter_getsockopt_kern(struct sock *sk, int level, + int optname, void *optval, + int *optlen, int retval) +{ + struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data); + struct bpf_sockopt_kern ctx = { + .sk = sk, + .level = level, + .optname = optname, + .retval = retval, + .optlen = *optlen, + .optval = optval, + .optval_end = optval + *optlen, + }; + int ret; + + /* Note that __cgroup_bpf_run_filter_getsockopt doesn't copy + * user data back into BPF buffer when reval != 0. This is + * done as an optimization to avoid extra copy, assuming + * kernel won't populate the data in case of an error. + * Here we always pass the data and memset() should + * be called if that data shouldn't be "exported". + */ + + ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[BPF_CGROUP_GETSOCKOPT], + &ctx, BPF_PROG_RUN); + if (!ret) + return -EPERM; + + if (ctx.optlen > *optlen) + return -EFAULT; + + /* BPF programs only allowed to set retval to 0, not some + * arbitrary value. + */ + if (ctx.retval != 0 && ctx.retval != retval) + return -EFAULT; + + /* BPF programs can shrink the buffer, export the modifications. + */ + if (ctx.optlen != 0) + *optlen = ctx.optlen; + + return ctx.retval; +} #endif static ssize_t sysctl_cpy_dir(const struct ctl_dir *dir, char **bufp, diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 856ae516ac18..26aa923cf522 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -4099,6 +4099,8 @@ static int do_tcp_getsockopt(struct sock *sk, int level, return -EFAULT; lock_sock(sk); err = tcp_zerocopy_receive(sk, &zc); + err = BPF_CGROUP_RUN_PROG_GETSOCKOPT_KERN(sk, level, optname, + &zc, &len, err); release_sock(sk); if (len >= offsetofend(struct tcp_zerocopy_receive, err)) goto zerocopy_rcv_sk_err; @@ -4133,6 +4135,18 @@ zerocopy_rcv_out: return 0; } +bool tcp_bpf_bypass_getsockopt(int level, int optname) +{ + /* TCP do_tcp_getsockopt has optimized getsockopt implementation + * to avoid extra socket lock for TCP_ZEROCOPY_RECEIVE. + */ + if (level == SOL_TCP && optname == TCP_ZEROCOPY_RECEIVE) + return true; + + return false; +} +EXPORT_SYMBOL(tcp_bpf_bypass_getsockopt); + int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen) { diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 777306b5bc22..62b6fd385a47 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -2793,6 +2793,7 @@ struct proto tcp_prot = { .shutdown = tcp_shutdown, .setsockopt = tcp_setsockopt, .getsockopt = tcp_getsockopt, + .bpf_bypass_getsockopt = tcp_bpf_bypass_getsockopt, .keepalive = tcp_set_keepalive, .recvmsg = tcp_recvmsg, .sendmsg = tcp_sendmsg, diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 0e1509b02cb3..8539715ff035 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -2121,6 +2121,7 @@ struct proto tcpv6_prot = { .shutdown = tcp_shutdown, .setsockopt = tcp_setsockopt, .getsockopt = tcp_getsockopt, + .bpf_bypass_getsockopt = tcp_bpf_bypass_getsockopt, .keepalive = tcp_set_keepalive, .recvmsg = tcp_recvmsg, .sendmsg = tcp_sendmsg, diff --git a/net/socket.c b/net/socket.c index 33e8b6c4e1d3..7f0617ab5437 100644 --- a/net/socket.c +++ b/net/socket.c @@ -2126,6 +2126,9 @@ SYSCALL_DEFINE5(setsockopt, int, fd, int, level, int, optname, return __sys_setsockopt(fd, level, optname, optval, optlen); } +INDIRECT_CALLABLE_DECLARE(bool tcp_bpf_bypass_getsockopt(int level, + int optname)); + /* * Get a socket option. Because we don't know the option lengths we have * to pass a user mode parameter for the protocols to sort out. diff --git a/tools/include/uapi/linux/tcp.h b/tools/include/uapi/linux/tcp.h new file mode 100644 index 000000000000..13ceeb395eb8 --- /dev/null +++ b/tools/include/uapi/linux/tcp.h @@ -0,0 +1,357 @@ +/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */ +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * Definitions for the TCP protocol. + * + * Version: @(#)tcp.h 1.0.2 04/28/93 + * + * Author: Fred N. van Kempen, + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ +#ifndef _UAPI_LINUX_TCP_H +#define _UAPI_LINUX_TCP_H + +#include +#include +#include + +struct tcphdr { + __be16 source; + __be16 dest; + __be32 seq; + __be32 ack_seq; +#if defined(__LITTLE_ENDIAN_BITFIELD) + __u16 res1:4, + doff:4, + fin:1, + syn:1, + rst:1, + psh:1, + ack:1, + urg:1, + ece:1, + cwr:1; +#elif defined(__BIG_ENDIAN_BITFIELD) + __u16 doff:4, + res1:4, + cwr:1, + ece:1, + urg:1, + ack:1, + psh:1, + rst:1, + syn:1, + fin:1; +#else +#error "Adjust your defines" +#endif + __be16 window; + __sum16 check; + __be16 urg_ptr; +}; + +/* + * The union cast uses a gcc extension to avoid aliasing problems + * (union is compatible to any of its members) + * This means this part of the code is -fstrict-aliasing safe now. + */ +union tcp_word_hdr { + struct tcphdr hdr; + __be32 words[5]; +}; + +#define tcp_flag_word(tp) ( ((union tcp_word_hdr *)(tp))->words [3]) + +enum { + TCP_FLAG_CWR = __constant_cpu_to_be32(0x00800000), + TCP_FLAG_ECE = __constant_cpu_to_be32(0x00400000), + TCP_FLAG_URG = __constant_cpu_to_be32(0x00200000), + TCP_FLAG_ACK = __constant_cpu_to_be32(0x00100000), + TCP_FLAG_PSH = __constant_cpu_to_be32(0x00080000), + TCP_FLAG_RST = __constant_cpu_to_be32(0x00040000), + TCP_FLAG_SYN = __constant_cpu_to_be32(0x00020000), + TCP_FLAG_FIN = __constant_cpu_to_be32(0x00010000), + TCP_RESERVED_BITS = __constant_cpu_to_be32(0x0F000000), + TCP_DATA_OFFSET = __constant_cpu_to_be32(0xF0000000) +}; + +/* + * TCP general constants + */ +#define TCP_MSS_DEFAULT 536U /* IPv4 (RFC1122, RFC2581) */ +#define TCP_MSS_DESIRED 1220U /* IPv6 (tunneled), EDNS0 (RFC3226) */ + +/* TCP socket options */ +#define TCP_NODELAY 1 /* Turn off Nagle's algorithm. */ +#define TCP_MAXSEG 2 /* Limit MSS */ +#define TCP_CORK 3 /* Never send partially complete segments */ +#define TCP_KEEPIDLE 4 /* Start keeplives after this period */ +#define TCP_KEEPINTVL 5 /* Interval between keepalives */ +#define TCP_KEEPCNT 6 /* Number of keepalives before death */ +#define TCP_SYNCNT 7 /* Number of SYN retransmits */ +#define TCP_LINGER2 8 /* Life time of orphaned FIN-WAIT-2 state */ +#define TCP_DEFER_ACCEPT 9 /* Wake up listener only when data arrive */ +#define TCP_WINDOW_CLAMP 10 /* Bound advertised window */ +#define TCP_INFO 11 /* Information about this connection. */ +#define TCP_QUICKACK 12 /* Block/reenable quick acks */ +#define TCP_CONGESTION 13 /* Congestion control algorithm */ +#define TCP_MD5SIG 14 /* TCP MD5 Signature (RFC2385) */ +#define TCP_THIN_LINEAR_TIMEOUTS 16 /* Use linear timeouts for thin streams*/ +#define TCP_THIN_DUPACK 17 /* Fast retrans. after 1 dupack */ +#define TCP_USER_TIMEOUT 18 /* How long for loss retry before timeout */ +#define TCP_REPAIR 19 /* TCP sock is under repair right now */ +#define TCP_REPAIR_QUEUE 20 +#define TCP_QUEUE_SEQ 21 +#define TCP_REPAIR_OPTIONS 22 +#define TCP_FASTOPEN 23 /* Enable FastOpen on listeners */ +#define TCP_TIMESTAMP 24 +#define TCP_NOTSENT_LOWAT 25 /* limit number of unsent bytes in write queue */ +#define TCP_CC_INFO 26 /* Get Congestion Control (optional) info */ +#define TCP_SAVE_SYN 27 /* Record SYN headers for new connections */ +#define TCP_SAVED_SYN 28 /* Get SYN headers recorded for connection */ +#define TCP_REPAIR_WINDOW 29 /* Get/set window parameters */ +#define TCP_FASTOPEN_CONNECT 30 /* Attempt FastOpen with connect */ +#define TCP_ULP 31 /* Attach a ULP to a TCP connection */ +#define TCP_MD5SIG_EXT 32 /* TCP MD5 Signature with extensions */ +#define TCP_FASTOPEN_KEY 33 /* Set the key for Fast Open (cookie) */ +#define TCP_FASTOPEN_NO_COOKIE 34 /* Enable TFO without a TFO cookie */ +#define TCP_ZEROCOPY_RECEIVE 35 +#define TCP_INQ 36 /* Notify bytes available to read as a cmsg on read */ + +#define TCP_CM_INQ TCP_INQ + +#define TCP_TX_DELAY 37 /* delay outgoing packets by XX usec */ + + +#define TCP_REPAIR_ON 1 +#define TCP_REPAIR_OFF 0 +#define TCP_REPAIR_OFF_NO_WP -1 /* Turn off without window probes */ + +struct tcp_repair_opt { + __u32 opt_code; + __u32 opt_val; +}; + +struct tcp_repair_window { + __u32 snd_wl1; + __u32 snd_wnd; + __u32 max_window; + + __u32 rcv_wnd; + __u32 rcv_wup; +}; + +enum { + TCP_NO_QUEUE, + TCP_RECV_QUEUE, + TCP_SEND_QUEUE, + TCP_QUEUES_NR, +}; + +/* why fastopen failed from client perspective */ +enum tcp_fastopen_client_fail { + TFO_STATUS_UNSPEC, /* catch-all */ + TFO_COOKIE_UNAVAILABLE, /* if not in TFO_CLIENT_NO_COOKIE mode */ + TFO_DATA_NOT_ACKED, /* SYN-ACK did not ack SYN data */ + TFO_SYN_RETRANSMITTED, /* SYN-ACK did not ack SYN data after timeout */ +}; + +/* for TCP_INFO socket option */ +#define TCPI_OPT_TIMESTAMPS 1 +#define TCPI_OPT_SACK 2 +#define TCPI_OPT_WSCALE 4 +#define TCPI_OPT_ECN 8 /* ECN was negociated at TCP session init */ +#define TCPI_OPT_ECN_SEEN 16 /* we received at least one packet with ECT */ +#define TCPI_OPT_SYN_DATA 32 /* SYN-ACK acked data in SYN sent or rcvd */ + +/* + * Sender's congestion state indicating normal or abnormal situations + * in the last round of packets sent. The state is driven by the ACK + * information and timer events. + */ +enum tcp_ca_state { + /* + * Nothing bad has been observed recently. + * No apparent reordering, packet loss, or ECN marks. + */ + TCP_CA_Open = 0, +#define TCPF_CA_Open (1< +#include #include #include "bpf_dctcp.skel.h" #include "bpf_cubic.skel.h" diff --git a/tools/testing/selftests/bpf/prog_tests/cls_redirect.c b/tools/testing/selftests/bpf/prog_tests/cls_redirect.c index 9781d85cb223..e075d03ab630 100644 --- a/tools/testing/selftests/bpf/prog_tests/cls_redirect.c +++ b/tools/testing/selftests/bpf/prog_tests/cls_redirect.c @@ -7,6 +7,7 @@ #include #include +#include #include diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c index 85f73261fab0..b8b48cac2ac3 100644 --- a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c +++ b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 // Copyright (c) 2020 Cloudflare #include +#include #include "test_progs.h" #include "test_skmsg_load_helpers.skel.h" diff --git a/tools/testing/selftests/bpf/prog_tests/sockopt_sk.c b/tools/testing/selftests/bpf/prog_tests/sockopt_sk.c index b25c9c45c148..d5b44b135c00 100644 --- a/tools/testing/selftests/bpf/prog_tests/sockopt_sk.c +++ b/tools/testing/selftests/bpf/prog_tests/sockopt_sk.c @@ -2,6 +2,12 @@ #include #include "cgroup_helpers.h" +#include + +#ifndef SOL_TCP +#define SOL_TCP IPPROTO_TCP +#endif + #define SOL_CUSTOM 0xdeadbeef static int getsetsockopt(void) @@ -11,6 +17,7 @@ static int getsetsockopt(void) char u8[4]; __u32 u32; char cc[16]; /* TCP_CA_NAME_MAX */ + struct tcp_zerocopy_receive zc; } buf = {}; socklen_t optlen; char *big_buf = NULL; @@ -154,6 +161,27 @@ static int getsetsockopt(void) goto err; } + /* TCP_ZEROCOPY_RECEIVE triggers */ + memset(&buf, 0, sizeof(buf)); + optlen = sizeof(buf.zc); + err = getsockopt(fd, SOL_TCP, TCP_ZEROCOPY_RECEIVE, &buf, &optlen); + if (err) { + log_err("Unexpected getsockopt(TCP_ZEROCOPY_RECEIVE) err=%d errno=%d", + err, errno); + goto err; + } + + memset(&buf, 0, sizeof(buf)); + buf.zc.address = 12345; /* rejected by BPF */ + optlen = sizeof(buf.zc); + errno = 0; + err = getsockopt(fd, SOL_TCP, TCP_ZEROCOPY_RECEIVE, &buf, &optlen); + if (errno != EPERM) { + log_err("Unexpected getsockopt(TCP_ZEROCOPY_RECEIVE) err=%d errno=%d", + err, errno); + goto err; + } + free(big_buf); close(fd); return 0; diff --git a/tools/testing/selftests/bpf/progs/sockopt_sk.c b/tools/testing/selftests/bpf/progs/sockopt_sk.c index 712df7b49cb1..d3597f81e6e9 100644 --- a/tools/testing/selftests/bpf/progs/sockopt_sk.c +++ b/tools/testing/selftests/bpf/progs/sockopt_sk.c @@ -1,8 +1,8 @@ // SPDX-License-Identifier: GPL-2.0 #include -#include -#include +#include #include +#include #include char _license[] SEC("license") = "GPL"; @@ -12,6 +12,10 @@ __u32 _version SEC("version") = 1; #define PAGE_SIZE 4096 #endif +#ifndef SOL_TCP +#define SOL_TCP IPPROTO_TCP +#endif + #define SOL_CUSTOM 0xdeadbeef struct sockopt_sk { @@ -57,6 +61,21 @@ int _getsockopt(struct bpf_sockopt *ctx) return 1; } + if (ctx->level == SOL_TCP && ctx->optname == TCP_ZEROCOPY_RECEIVE) { + /* Verify that TCP_ZEROCOPY_RECEIVE triggers. + * It has a custom implementation for performance + * reasons. + */ + + if (optval + sizeof(struct tcp_zerocopy_receive) > optval_end) + return 0; /* EPERM, bounds check */ + + if (((struct tcp_zerocopy_receive *)optval)->address != 0) + return 0; /* EPERM, unexpected data */ + + return 1; + } + if (ctx->level == SOL_IP && ctx->optname == IP_FREEBIND) { if (optval + 1 > optval_end) return 0; /* EPERM, bounds check */ diff --git a/tools/testing/selftests/bpf/test_progs.h b/tools/testing/selftests/bpf/test_progs.h index e49e2fdde942..f7c2fd89d01a 100644 --- a/tools/testing/selftests/bpf/test_progs.h +++ b/tools/testing/selftests/bpf/test_progs.h @@ -16,7 +16,6 @@ typedef __u16 __sum16; #include #include #include -#include #include #include #include -- cgit v1.2.3 From a9ed15dae0755a0368735e0556a462d8519bdb05 Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Fri, 15 Jan 2021 08:35:01 -0800 Subject: bpf: Split cgroup_bpf_enabled per attach type When we attach any cgroup hook, the rest (even if unused/unattached) start to contribute small overhead. In particular, the one we want to avoid is __cgroup_bpf_run_filter_skb which does two redirections to get to the cgroup and pushes/pulls skb. Let's split cgroup_bpf_enabled to be per-attach to make sure only used attach types trigger. I've dropped some existing high-level cgroup_bpf_enabled in some places because BPF_PROG_CGROUP_XXX_RUN macros usually have another cgroup_bpf_enabled check. I also had to copy-paste BPF_CGROUP_RUN_SA_PROG_LOCK for GETPEERNAME/GETSOCKNAME because type for cgroup_bpf_enabled[type] has to be constant and known at compile time. Signed-off-by: Stanislav Fomichev Signed-off-by: Alexei Starovoitov Acked-by: Song Liu Link: https://lore.kernel.org/bpf/20210115163501.805133-4-sdf@google.com --- include/linux/bpf-cgroup.h | 38 ++++++++++++++++++++------------------ kernel/bpf/cgroup.c | 14 ++++++-------- net/ipv4/af_inet.c | 9 +++++---- net/ipv4/udp.c | 7 +++---- net/ipv6/af_inet6.c | 9 +++++---- net/ipv6/udp.c | 7 +++---- 6 files changed, 42 insertions(+), 42 deletions(-) (limited to 'net') diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h index bcb2915e6124..0748fd87969e 100644 --- a/include/linux/bpf-cgroup.h +++ b/include/linux/bpf-cgroup.h @@ -23,8 +23,8 @@ struct ctl_table_header; #ifdef CONFIG_CGROUP_BPF -extern struct static_key_false cgroup_bpf_enabled_key; -#define cgroup_bpf_enabled static_branch_unlikely(&cgroup_bpf_enabled_key) +extern struct static_key_false cgroup_bpf_enabled_key[MAX_BPF_ATTACH_TYPE]; +#define cgroup_bpf_enabled(type) static_branch_unlikely(&cgroup_bpf_enabled_key[type]) DECLARE_PER_CPU(struct bpf_cgroup_storage*, bpf_cgroup_storage[MAX_BPF_CGROUP_STORAGE_TYPE]); @@ -189,7 +189,7 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, #define BPF_CGROUP_RUN_PROG_INET_INGRESS(sk, skb) \ ({ \ int __ret = 0; \ - if (cgroup_bpf_enabled) \ + if (cgroup_bpf_enabled(BPF_CGROUP_INET_INGRESS)) \ __ret = __cgroup_bpf_run_filter_skb(sk, skb, \ BPF_CGROUP_INET_INGRESS); \ \ @@ -199,7 +199,7 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, #define BPF_CGROUP_RUN_PROG_INET_EGRESS(sk, skb) \ ({ \ int __ret = 0; \ - if (cgroup_bpf_enabled && sk && sk == skb->sk) { \ + if (cgroup_bpf_enabled(BPF_CGROUP_INET_EGRESS) && sk && sk == skb->sk) { \ typeof(sk) __sk = sk_to_full_sk(sk); \ if (sk_fullsock(__sk)) \ __ret = __cgroup_bpf_run_filter_skb(__sk, skb, \ @@ -211,7 +211,7 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, #define BPF_CGROUP_RUN_SK_PROG(sk, type) \ ({ \ int __ret = 0; \ - if (cgroup_bpf_enabled) { \ + if (cgroup_bpf_enabled(type)) { \ __ret = __cgroup_bpf_run_filter_sk(sk, type); \ } \ __ret; \ @@ -232,7 +232,7 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, #define BPF_CGROUP_RUN_SA_PROG(sk, uaddr, type) \ ({ \ int __ret = 0; \ - if (cgroup_bpf_enabled) \ + if (cgroup_bpf_enabled(type)) \ __ret = __cgroup_bpf_run_filter_sock_addr(sk, uaddr, type, \ NULL); \ __ret; \ @@ -241,7 +241,7 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, #define BPF_CGROUP_RUN_SA_PROG_LOCK(sk, uaddr, type, t_ctx) \ ({ \ int __ret = 0; \ - if (cgroup_bpf_enabled) { \ + if (cgroup_bpf_enabled(type)) { \ lock_sock(sk); \ __ret = __cgroup_bpf_run_filter_sock_addr(sk, uaddr, type, \ t_ctx); \ @@ -256,8 +256,10 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, #define BPF_CGROUP_RUN_PROG_INET6_BIND_LOCK(sk, uaddr) \ BPF_CGROUP_RUN_SA_PROG_LOCK(sk, uaddr, BPF_CGROUP_INET6_BIND, NULL) -#define BPF_CGROUP_PRE_CONNECT_ENABLED(sk) (cgroup_bpf_enabled && \ - sk->sk_prot->pre_connect) +#define BPF_CGROUP_PRE_CONNECT_ENABLED(sk) \ + ((cgroup_bpf_enabled(BPF_CGROUP_INET4_CONNECT) || \ + cgroup_bpf_enabled(BPF_CGROUP_INET6_CONNECT)) && \ + (sk)->sk_prot->pre_connect) #define BPF_CGROUP_RUN_PROG_INET4_CONNECT(sk, uaddr) \ BPF_CGROUP_RUN_SA_PROG(sk, uaddr, BPF_CGROUP_INET4_CONNECT) @@ -301,7 +303,7 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, #define BPF_CGROUP_RUN_PROG_SOCK_OPS_SK(sock_ops, sk) \ ({ \ int __ret = 0; \ - if (cgroup_bpf_enabled) \ + if (cgroup_bpf_enabled(BPF_CGROUP_SOCK_OPS)) \ __ret = __cgroup_bpf_run_filter_sock_ops(sk, \ sock_ops, \ BPF_CGROUP_SOCK_OPS); \ @@ -311,7 +313,7 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, #define BPF_CGROUP_RUN_PROG_SOCK_OPS(sock_ops) \ ({ \ int __ret = 0; \ - if (cgroup_bpf_enabled && (sock_ops)->sk) { \ + if (cgroup_bpf_enabled(BPF_CGROUP_SOCK_OPS) && (sock_ops)->sk) { \ typeof(sk) __sk = sk_to_full_sk((sock_ops)->sk); \ if (__sk && sk_fullsock(__sk)) \ __ret = __cgroup_bpf_run_filter_sock_ops(__sk, \ @@ -324,7 +326,7 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, #define BPF_CGROUP_RUN_PROG_DEVICE_CGROUP(type, major, minor, access) \ ({ \ int __ret = 0; \ - if (cgroup_bpf_enabled) \ + if (cgroup_bpf_enabled(BPF_CGROUP_DEVICE)) \ __ret = __cgroup_bpf_check_dev_permission(type, major, minor, \ access, \ BPF_CGROUP_DEVICE); \ @@ -336,7 +338,7 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, #define BPF_CGROUP_RUN_PROG_SYSCTL(head, table, write, buf, count, pos) \ ({ \ int __ret = 0; \ - if (cgroup_bpf_enabled) \ + if (cgroup_bpf_enabled(BPF_CGROUP_SYSCTL)) \ __ret = __cgroup_bpf_run_filter_sysctl(head, table, write, \ buf, count, pos, \ BPF_CGROUP_SYSCTL); \ @@ -347,7 +349,7 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, kernel_optval) \ ({ \ int __ret = 0; \ - if (cgroup_bpf_enabled) \ + if (cgroup_bpf_enabled(BPF_CGROUP_SETSOCKOPT)) \ __ret = __cgroup_bpf_run_filter_setsockopt(sock, level, \ optname, optval, \ optlen, \ @@ -358,7 +360,7 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, #define BPF_CGROUP_GETSOCKOPT_MAX_OPTLEN(optlen) \ ({ \ int __ret = 0; \ - if (cgroup_bpf_enabled) \ + if (cgroup_bpf_enabled(BPF_CGROUP_GETSOCKOPT)) \ get_user(__ret, optlen); \ __ret; \ }) @@ -367,7 +369,7 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, max_optlen, retval) \ ({ \ int __ret = retval; \ - if (cgroup_bpf_enabled) \ + if (cgroup_bpf_enabled(BPF_CGROUP_GETSOCKOPT)) \ if (!(sock)->sk_prot->bpf_bypass_getsockopt || \ !INDIRECT_CALL_INET_1((sock)->sk_prot->bpf_bypass_getsockopt, \ tcp_bpf_bypass_getsockopt, \ @@ -382,7 +384,7 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, optlen, retval) \ ({ \ int __ret = retval; \ - if (cgroup_bpf_enabled) \ + if (cgroup_bpf_enabled(BPF_CGROUP_GETSOCKOPT)) \ __ret = __cgroup_bpf_run_filter_getsockopt_kern( \ sock, level, optname, optval, optlen, retval); \ __ret; \ @@ -444,7 +446,7 @@ static inline int bpf_percpu_cgroup_storage_update(struct bpf_map *map, return 0; } -#define cgroup_bpf_enabled (0) +#define cgroup_bpf_enabled(type) (0) #define BPF_CGROUP_RUN_SA_PROG_LOCK(sk, uaddr, type, t_ctx) ({ 0; }) #define BPF_CGROUP_PRE_CONNECT_ENABLED(sk) (0) #define BPF_CGROUP_RUN_PROG_INET_INGRESS(sk,skb) ({ 0; }) diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index ba8a1199d0ba..da649f20d6b2 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -19,7 +19,7 @@ #include "../cgroup/cgroup-internal.h" -DEFINE_STATIC_KEY_FALSE(cgroup_bpf_enabled_key); +DEFINE_STATIC_KEY_ARRAY_FALSE(cgroup_bpf_enabled_key, MAX_BPF_ATTACH_TYPE); EXPORT_SYMBOL(cgroup_bpf_enabled_key); void cgroup_bpf_offline(struct cgroup *cgrp) @@ -128,7 +128,7 @@ static void cgroup_bpf_release(struct work_struct *work) if (pl->link) bpf_cgroup_link_auto_detach(pl->link); kfree(pl); - static_branch_dec(&cgroup_bpf_enabled_key); + static_branch_dec(&cgroup_bpf_enabled_key[type]); } old_array = rcu_dereference_protected( cgrp->bpf.effective[type], @@ -499,7 +499,7 @@ int __cgroup_bpf_attach(struct cgroup *cgrp, if (old_prog) bpf_prog_put(old_prog); else - static_branch_inc(&cgroup_bpf_enabled_key); + static_branch_inc(&cgroup_bpf_enabled_key[type]); bpf_cgroup_storages_link(new_storage, cgrp, type); return 0; @@ -698,7 +698,7 @@ int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog, cgrp->bpf.flags[type] = 0; if (old_prog) bpf_prog_put(old_prog); - static_branch_dec(&cgroup_bpf_enabled_key); + static_branch_dec(&cgroup_bpf_enabled_key[type]); return 0; cleanup: @@ -1360,8 +1360,7 @@ int __cgroup_bpf_run_filter_setsockopt(struct sock *sk, int *level, * attached to the hook so we don't waste time allocating * memory and locking the socket. */ - if (!cgroup_bpf_enabled || - __cgroup_bpf_prog_array_is_empty(cgrp, BPF_CGROUP_SETSOCKOPT)) + if (__cgroup_bpf_prog_array_is_empty(cgrp, BPF_CGROUP_SETSOCKOPT)) return 0; /* Allocate a bit more than the initial user buffer for @@ -1457,8 +1456,7 @@ int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level, * attached to the hook so we don't waste time allocating * memory and locking the socket. */ - if (!cgroup_bpf_enabled || - __cgroup_bpf_prog_array_is_empty(cgrp, BPF_CGROUP_GETSOCKOPT)) + if (__cgroup_bpf_prog_array_is_empty(cgrp, BPF_CGROUP_GETSOCKOPT)) return retval; ctx.optlen = max_optlen; diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index b94fa8eb831b..6ba2930ff49b 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -777,18 +777,19 @@ int inet_getname(struct socket *sock, struct sockaddr *uaddr, return -ENOTCONN; sin->sin_port = inet->inet_dport; sin->sin_addr.s_addr = inet->inet_daddr; + BPF_CGROUP_RUN_SA_PROG_LOCK(sk, (struct sockaddr *)sin, + BPF_CGROUP_INET4_GETPEERNAME, + NULL); } else { __be32 addr = inet->inet_rcv_saddr; if (!addr) addr = inet->inet_saddr; sin->sin_port = inet->inet_sport; sin->sin_addr.s_addr = addr; - } - if (cgroup_bpf_enabled) BPF_CGROUP_RUN_SA_PROG_LOCK(sk, (struct sockaddr *)sin, - peer ? BPF_CGROUP_INET4_GETPEERNAME : - BPF_CGROUP_INET4_GETSOCKNAME, + BPF_CGROUP_INET4_GETSOCKNAME, NULL); + } memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); return sizeof(*sin); } diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 69ea76578abb..c67e483fce41 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1124,7 +1124,7 @@ int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) rcu_read_unlock(); } - if (cgroup_bpf_enabled && !connected) { + if (cgroup_bpf_enabled(BPF_CGROUP_UDP4_SENDMSG) && !connected) { err = BPF_CGROUP_RUN_PROG_UDP4_SENDMSG_LOCK(sk, (struct sockaddr *)usin, &ipc.addr); if (err) @@ -1858,9 +1858,8 @@ try_again: memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); *addr_len = sizeof(*sin); - if (cgroup_bpf_enabled) - BPF_CGROUP_RUN_PROG_UDP4_RECVMSG_LOCK(sk, - (struct sockaddr *)sin); + BPF_CGROUP_RUN_PROG_UDP4_RECVMSG_LOCK(sk, + (struct sockaddr *)sin); } if (udp_sk(sk)->gro_enabled) diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c index 8e9c3e9ea36e..b9c654836b72 100644 --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -527,18 +527,19 @@ int inet6_getname(struct socket *sock, struct sockaddr *uaddr, sin->sin6_addr = sk->sk_v6_daddr; if (np->sndflow) sin->sin6_flowinfo = np->flow_label; + BPF_CGROUP_RUN_SA_PROG_LOCK(sk, (struct sockaddr *)sin, + BPF_CGROUP_INET6_GETPEERNAME, + NULL); } else { if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) sin->sin6_addr = np->saddr; else sin->sin6_addr = sk->sk_v6_rcv_saddr; sin->sin6_port = inet->inet_sport; - } - if (cgroup_bpf_enabled) BPF_CGROUP_RUN_SA_PROG_LOCK(sk, (struct sockaddr *)sin, - peer ? BPF_CGROUP_INET6_GETPEERNAME : - BPF_CGROUP_INET6_GETSOCKNAME, + BPF_CGROUP_INET6_GETSOCKNAME, NULL); + } sin->sin6_scope_id = ipv6_iface_scope_id(&sin->sin6_addr, sk->sk_bound_dev_if); return sizeof(*sin); diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index b9f3dfdd2383..a02ac875a923 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -409,9 +409,8 @@ try_again: } *addr_len = sizeof(*sin6); - if (cgroup_bpf_enabled) - BPF_CGROUP_RUN_PROG_UDP6_RECVMSG_LOCK(sk, - (struct sockaddr *)sin6); + BPF_CGROUP_RUN_PROG_UDP6_RECVMSG_LOCK(sk, + (struct sockaddr *)sin6); } if (udp_sk(sk)->gro_enabled) @@ -1462,7 +1461,7 @@ do_udp_sendmsg: fl6.saddr = np->saddr; fl6.fl6_sport = inet->inet_sport; - if (cgroup_bpf_enabled && !connected) { + if (cgroup_bpf_enabled(BPF_CGROUP_UDP6_SENDMSG) && !connected) { err = BPF_CGROUP_RUN_PROG_UDP6_SENDMSG_LOCK(sk, (struct sockaddr *)sin6, &fl6.saddr); if (err) -- cgit v1.2.3 From 458f7272341265e443c227ba55ee4a338021a60a Mon Sep 17 00:00:00 2001 From: Björn Töpel Date: Fri, 22 Jan 2021 11:53:49 +0100 Subject: xsk: Remove explicit_free parameter from __xsk_rcv() The explicit_free parameter of the __xsk_rcv() function was used to mark whether the call was via the generic XDP or the native XDP path. Instead of clutter the code with if-statements and "true/false" parameters which are hard to understand, simply move the explicit free to the __xsk_map_redirect() which is always called from the native XDP path. Signed-off-by: Björn Töpel Signed-off-by: Daniel Borkmann Reviewed-by: Maciej Fijalkowski Link: https://lore.kernel.org/bpf/20210122105351.11751-2-bjorn.topel@gmail.com --- net/xdp/xsk.c | 47 +++++++++++++++++++++++++++++++---------------- 1 file changed, 31 insertions(+), 16 deletions(-) (limited to 'net') diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 4a83117507f5..4faabd1ecfd1 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -184,12 +184,13 @@ static void xsk_copy_xdp(struct xdp_buff *to, struct xdp_buff *from, u32 len) memcpy(to_buf, from_buf, len + metalen); } -static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len, - bool explicit_free) +static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) { struct xdp_buff *xsk_xdp; int err; + u32 len; + len = xdp->data_end - xdp->data; if (len > xsk_pool_get_rx_frame_size(xs->pool)) { xs->rx_dropped++; return -ENOSPC; @@ -207,8 +208,6 @@ static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len, xsk_buff_free(xsk_xdp); return err; } - if (explicit_free) - xdp_return_buff(xdp); return 0; } @@ -230,11 +229,8 @@ static bool xsk_is_bound(struct xdp_sock *xs) return false; } -static int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp, - bool explicit_free) +static int xsk_rcv_check(struct xdp_sock *xs, struct xdp_buff *xdp) { - u32 len; - if (!xsk_is_bound(xs)) return -EINVAL; @@ -242,11 +238,7 @@ static int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp, return -EINVAL; sk_mark_napi_id_once_xdp(&xs->sk, xdp); - len = xdp->data_end - xdp->data; - - return xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL ? - __xsk_rcv_zc(xs, xdp, len) : - __xsk_rcv(xs, xdp, len, explicit_free); + return 0; } static void xsk_flush(struct xdp_sock *xs) @@ -261,18 +253,41 @@ int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) int err; spin_lock_bh(&xs->rx_lock); - err = xsk_rcv(xs, xdp, false); - xsk_flush(xs); + err = xsk_rcv_check(xs, xdp); + if (!err) { + err = __xsk_rcv(xs, xdp); + xsk_flush(xs); + } spin_unlock_bh(&xs->rx_lock); return err; } +static int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) +{ + int err; + u32 len; + + err = xsk_rcv_check(xs, xdp); + if (err) + return err; + + if (xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL) { + len = xdp->data_end - xdp->data; + return __xsk_rcv_zc(xs, xdp, len); + } + + err = __xsk_rcv(xs, xdp); + if (!err) + xdp_return_buff(xdp); + return err; +} + int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp) { struct list_head *flush_list = this_cpu_ptr(&xskmap_flush_list); int err; - err = xsk_rcv(xs, xdp, true); + err = xsk_rcv(xs, xdp); if (err) return err; -- cgit v1.2.3 From f0863eab966b95f46f96708b25996c6615856484 Mon Sep 17 00:00:00 2001 From: Björn Töpel Date: Fri, 22 Jan 2021 11:53:50 +0100 Subject: xsk: Fold xp_assign_dev and __xp_assign_dev Fold xp_assign_dev and __xp_assign_dev. The former directly calls the latter. Signed-off-by: Björn Töpel Signed-off-by: Daniel Borkmann Reviewed-by: Maciej Fijalkowski Link: https://lore.kernel.org/bpf/20210122105351.11751-3-bjorn.topel@gmail.com --- net/xdp/xsk_buff_pool.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) (limited to 'net') diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c index 20598eea658c..8de01aaac4a0 100644 --- a/net/xdp/xsk_buff_pool.c +++ b/net/xdp/xsk_buff_pool.c @@ -119,8 +119,8 @@ static void xp_disable_drv_zc(struct xsk_buff_pool *pool) } } -static int __xp_assign_dev(struct xsk_buff_pool *pool, - struct net_device *netdev, u16 queue_id, u16 flags) +int xp_assign_dev(struct xsk_buff_pool *pool, + struct net_device *netdev, u16 queue_id, u16 flags) { bool force_zc, force_copy; struct netdev_bpf bpf; @@ -191,12 +191,6 @@ err_unreg_pool: return err; } -int xp_assign_dev(struct xsk_buff_pool *pool, struct net_device *dev, - u16 queue_id, u16 flags) -{ - return __xp_assign_dev(pool, dev, queue_id, flags); -} - int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_umem *umem, struct net_device *dev, u16 queue_id) { @@ -210,7 +204,7 @@ int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_umem *umem, if (pool->uses_need_wakeup) flags |= XDP_USE_NEED_WAKEUP; - return __xp_assign_dev(pool, dev, queue_id, flags); + return xp_assign_dev(pool, dev, queue_id, flags); } void xp_clear_dev(struct xsk_buff_pool *pool) -- cgit v1.2.3 From 8063e184e49011f6f3f34f6c358dc8a83890bb5b Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Wed, 27 Jan 2021 14:15:01 -0800 Subject: skmsg: Make sk_psock_destroy() static sk_psock_destroy() is a RCU callback, I can't see any reason why it could be used outside. Signed-off-by: Cong Wang Signed-off-by: Daniel Borkmann Cc: John Fastabend Cc: Jakub Sitnicki Cc: Lorenz Bauer Link: https://lore.kernel.org/bpf/20210127221501.46866-1-xiyou.wangcong@gmail.com --- include/linux/skmsg.h | 1 - net/core/skmsg.c | 3 +-- 2 files changed, 1 insertion(+), 3 deletions(-) (limited to 'net') diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h index fec0c5ac1c4f..8edbbf5f2f93 100644 --- a/include/linux/skmsg.h +++ b/include/linux/skmsg.h @@ -390,7 +390,6 @@ static inline struct sk_psock *sk_psock_get(struct sock *sk) } void sk_psock_stop(struct sock *sk, struct sk_psock *psock); -void sk_psock_destroy(struct rcu_head *rcu); void sk_psock_drop(struct sock *sk, struct sk_psock *psock); static inline void sk_psock_put(struct sock *sk, struct sk_psock *psock) diff --git a/net/core/skmsg.c b/net/core/skmsg.c index 25cdbb20f3a0..1261512d6807 100644 --- a/net/core/skmsg.c +++ b/net/core/skmsg.c @@ -669,14 +669,13 @@ static void sk_psock_destroy_deferred(struct work_struct *gc) kfree(psock); } -void sk_psock_destroy(struct rcu_head *rcu) +static void sk_psock_destroy(struct rcu_head *rcu) { struct sk_psock *psock = container_of(rcu, struct sk_psock, rcu); INIT_WORK(&psock->gc, sk_psock_destroy_deferred); schedule_work(&psock->gc); } -EXPORT_SYMBOL_GPL(sk_psock_destroy); void sk_psock_drop(struct sock *sk, struct sk_psock *psock) { -- cgit v1.2.3 From 772412176fb98493158929b220fe250127f611af Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Wed, 27 Jan 2021 11:31:39 -0800 Subject: bpf: Allow rewriting to ports under ip_unprivileged_port_start At the moment, BPF_CGROUP_INET{4,6}_BIND hooks can rewrite user_port to the privileged ones (< ip_unprivileged_port_start), but it will be rejected later on in the __inet_bind or __inet6_bind. Let's add another return value to indicate that CAP_NET_BIND_SERVICE check should be ignored. Use the same idea as we currently use in cgroup/egress where bit #1 indicates CN. Instead, for cgroup/bind{4,6}, bit #1 indicates that CAP_NET_BIND_SERVICE should be bypassed. v5: - rename flags to be less confusing (Andrey Ignatov) - rework BPF_PROG_CGROUP_INET_EGRESS_RUN_ARRAY to work on flags and accept BPF_RET_SET_CN (no behavioral changes) v4: - Add missing IPv6 support (Martin KaFai Lau) v3: - Update description (Martin KaFai Lau) - Fix capability restore in selftest (Martin KaFai Lau) v2: - Switch to explicit return code (Martin KaFai Lau) Signed-off-by: Stanislav Fomichev Signed-off-by: Alexei Starovoitov Reviewed-by: Martin KaFai Lau Acked-by: Andrey Ignatov Link: https://lore.kernel.org/bpf/20210127193140.3170382-1-sdf@google.com --- include/linux/bpf-cgroup.h | 38 ++++++++++++++++++++++++--------- include/linux/bpf.h | 52 +++++++++++++++++++++++++++++----------------- include/net/inet_common.h | 2 ++ kernel/bpf/cgroup.c | 8 +++++-- kernel/bpf/verifier.c | 3 +++ net/ipv4/af_inet.c | 9 +++++--- net/ipv6/af_inet6.c | 9 +++++--- 7 files changed, 84 insertions(+), 37 deletions(-) (limited to 'net') diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h index 0748fd87969e..c42e02b4d84b 100644 --- a/include/linux/bpf-cgroup.h +++ b/include/linux/bpf-cgroup.h @@ -125,7 +125,8 @@ int __cgroup_bpf_run_filter_sk(struct sock *sk, int __cgroup_bpf_run_filter_sock_addr(struct sock *sk, struct sockaddr *uaddr, enum bpf_attach_type type, - void *t_ctx); + void *t_ctx, + u32 *flags); int __cgroup_bpf_run_filter_sock_ops(struct sock *sk, struct bpf_sock_ops_kern *sock_ops, @@ -231,30 +232,48 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, #define BPF_CGROUP_RUN_SA_PROG(sk, uaddr, type) \ ({ \ + u32 __unused_flags; \ int __ret = 0; \ if (cgroup_bpf_enabled(type)) \ __ret = __cgroup_bpf_run_filter_sock_addr(sk, uaddr, type, \ - NULL); \ + NULL, \ + &__unused_flags); \ __ret; \ }) #define BPF_CGROUP_RUN_SA_PROG_LOCK(sk, uaddr, type, t_ctx) \ ({ \ + u32 __unused_flags; \ int __ret = 0; \ if (cgroup_bpf_enabled(type)) { \ lock_sock(sk); \ __ret = __cgroup_bpf_run_filter_sock_addr(sk, uaddr, type, \ - t_ctx); \ + t_ctx, \ + &__unused_flags); \ release_sock(sk); \ } \ __ret; \ }) -#define BPF_CGROUP_RUN_PROG_INET4_BIND_LOCK(sk, uaddr) \ - BPF_CGROUP_RUN_SA_PROG_LOCK(sk, uaddr, BPF_CGROUP_INET4_BIND, NULL) - -#define BPF_CGROUP_RUN_PROG_INET6_BIND_LOCK(sk, uaddr) \ - BPF_CGROUP_RUN_SA_PROG_LOCK(sk, uaddr, BPF_CGROUP_INET6_BIND, NULL) +/* BPF_CGROUP_INET4_BIND and BPF_CGROUP_INET6_BIND can return extra flags + * via upper bits of return code. The only flag that is supported + * (at bit position 0) is to indicate CAP_NET_BIND_SERVICE capability check + * should be bypassed (BPF_RET_BIND_NO_CAP_NET_BIND_SERVICE). + */ +#define BPF_CGROUP_RUN_PROG_INET_BIND_LOCK(sk, uaddr, type, bind_flags) \ +({ \ + u32 __flags = 0; \ + int __ret = 0; \ + if (cgroup_bpf_enabled(type)) { \ + lock_sock(sk); \ + __ret = __cgroup_bpf_run_filter_sock_addr(sk, uaddr, type, \ + NULL, &__flags); \ + release_sock(sk); \ + if (__flags & BPF_RET_BIND_NO_CAP_NET_BIND_SERVICE) \ + *bind_flags |= BIND_NO_CAP_NET_BIND_SERVICE; \ + } \ + __ret; \ +}) #define BPF_CGROUP_PRE_CONNECT_ENABLED(sk) \ ((cgroup_bpf_enabled(BPF_CGROUP_INET4_CONNECT) || \ @@ -453,8 +472,7 @@ static inline int bpf_percpu_cgroup_storage_update(struct bpf_map *map, #define BPF_CGROUP_RUN_PROG_INET_EGRESS(sk,skb) ({ 0; }) #define BPF_CGROUP_RUN_PROG_INET_SOCK(sk) ({ 0; }) #define BPF_CGROUP_RUN_PROG_INET_SOCK_RELEASE(sk) ({ 0; }) -#define BPF_CGROUP_RUN_PROG_INET4_BIND_LOCK(sk, uaddr) ({ 0; }) -#define BPF_CGROUP_RUN_PROG_INET6_BIND_LOCK(sk, uaddr) ({ 0; }) +#define BPF_CGROUP_RUN_PROG_INET_BIND_LOCK(sk, uaddr, type, flags) ({ 0; }) #define BPF_CGROUP_RUN_PROG_INET4_POST_BIND(sk) ({ 0; }) #define BPF_CGROUP_RUN_PROG_INET6_POST_BIND(sk) ({ 0; }) #define BPF_CGROUP_RUN_PROG_INET4_CONNECT(sk, uaddr) ({ 0; }) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 1aac2af12fed..321966fc35db 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1073,6 +1073,34 @@ int bpf_prog_array_copy(struct bpf_prog_array *old_array, struct bpf_prog *include_prog, struct bpf_prog_array **new_array); +/* BPF program asks to bypass CAP_NET_BIND_SERVICE in bind. */ +#define BPF_RET_BIND_NO_CAP_NET_BIND_SERVICE (1 << 0) +/* BPF program asks to set CN on the packet. */ +#define BPF_RET_SET_CN (1 << 0) + +#define BPF_PROG_RUN_ARRAY_FLAGS(array, ctx, func, ret_flags) \ + ({ \ + struct bpf_prog_array_item *_item; \ + struct bpf_prog *_prog; \ + struct bpf_prog_array *_array; \ + u32 _ret = 1; \ + u32 func_ret; \ + migrate_disable(); \ + rcu_read_lock(); \ + _array = rcu_dereference(array); \ + _item = &_array->items[0]; \ + while ((_prog = READ_ONCE(_item->prog))) { \ + bpf_cgroup_storage_set(_item->cgroup_storage); \ + func_ret = func(_prog, ctx); \ + _ret &= (func_ret & 1); \ + *(ret_flags) |= (func_ret >> 1); \ + _item++; \ + } \ + rcu_read_unlock(); \ + migrate_enable(); \ + _ret; \ + }) + #define __BPF_PROG_RUN_ARRAY(array, ctx, func, check_non_null) \ ({ \ struct bpf_prog_array_item *_item; \ @@ -1120,25 +1148,11 @@ _out: \ */ #define BPF_PROG_CGROUP_INET_EGRESS_RUN_ARRAY(array, ctx, func) \ ({ \ - struct bpf_prog_array_item *_item; \ - struct bpf_prog *_prog; \ - struct bpf_prog_array *_array; \ - u32 ret; \ - u32 _ret = 1; \ - u32 _cn = 0; \ - migrate_disable(); \ - rcu_read_lock(); \ - _array = rcu_dereference(array); \ - _item = &_array->items[0]; \ - while ((_prog = READ_ONCE(_item->prog))) { \ - bpf_cgroup_storage_set(_item->cgroup_storage); \ - ret = func(_prog, ctx); \ - _ret &= (ret & 1); \ - _cn |= (ret & 2); \ - _item++; \ - } \ - rcu_read_unlock(); \ - migrate_enable(); \ + u32 _flags = 0; \ + bool _cn; \ + u32 _ret; \ + _ret = BPF_PROG_RUN_ARRAY_FLAGS(array, ctx, func, &_flags); \ + _cn = _flags & BPF_RET_SET_CN; \ if (_ret) \ _ret = (_cn ? NET_XMIT_CN : NET_XMIT_SUCCESS); \ else \ diff --git a/include/net/inet_common.h b/include/net/inet_common.h index cb2818862919..cad2a611efde 100644 --- a/include/net/inet_common.h +++ b/include/net/inet_common.h @@ -41,6 +41,8 @@ int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len); #define BIND_WITH_LOCK (1 << 1) /* Called from BPF program. */ #define BIND_FROM_BPF (1 << 2) +/* Skip CAP_NET_BIND_SERVICE check. */ +#define BIND_NO_CAP_NET_BIND_SERVICE (1 << 3) int __inet_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len, u32 flags); int inet_getname(struct socket *sock, struct sockaddr *uaddr, diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index da649f20d6b2..cdf3c7e611d9 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -1055,6 +1055,8 @@ EXPORT_SYMBOL(__cgroup_bpf_run_filter_sk); * @uaddr: sockaddr struct provided by user * @type: The type of program to be exectuted * @t_ctx: Pointer to attach type specific context + * @flags: Pointer to u32 which contains higher bits of BPF program + * return value (OR'ed together). * * socket is expected to be of type INET or INET6. * @@ -1064,7 +1066,8 @@ EXPORT_SYMBOL(__cgroup_bpf_run_filter_sk); int __cgroup_bpf_run_filter_sock_addr(struct sock *sk, struct sockaddr *uaddr, enum bpf_attach_type type, - void *t_ctx) + void *t_ctx, + u32 *flags) { struct bpf_sock_addr_kern ctx = { .sk = sk, @@ -1087,7 +1090,8 @@ int __cgroup_bpf_run_filter_sock_addr(struct sock *sk, } cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data); - ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], &ctx, BPF_PROG_RUN); + ret = BPF_PROG_RUN_ARRAY_FLAGS(cgrp->bpf.effective[type], &ctx, + BPF_PROG_RUN, flags); return ret == 1 ? 0 : -EPERM; } diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index d0eae51b31e4..972fc38eb62d 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -7986,6 +7986,9 @@ static int check_return_code(struct bpf_verifier_env *env) env->prog->expected_attach_type == BPF_CGROUP_INET4_GETSOCKNAME || env->prog->expected_attach_type == BPF_CGROUP_INET6_GETSOCKNAME) range = tnum_range(1, 1); + if (env->prog->expected_attach_type == BPF_CGROUP_INET4_BIND || + env->prog->expected_attach_type == BPF_CGROUP_INET6_BIND) + range = tnum_range(0, 3); break; case BPF_PROG_TYPE_CGROUP_SKB: if (env->prog->expected_attach_type == BPF_CGROUP_INET_EGRESS) { diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 6ba2930ff49b..aaa94bea19c3 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -438,6 +438,7 @@ EXPORT_SYMBOL(inet_release); int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) { struct sock *sk = sock->sk; + u32 flags = BIND_WITH_LOCK; int err; /* If the socket has its own bind function then use it. (RAW) */ @@ -450,11 +451,12 @@ int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) /* BPF prog is run before any checks are done so that if the prog * changes context in a wrong way it will be caught. */ - err = BPF_CGROUP_RUN_PROG_INET4_BIND_LOCK(sk, uaddr); + err = BPF_CGROUP_RUN_PROG_INET_BIND_LOCK(sk, uaddr, + BPF_CGROUP_INET4_BIND, &flags); if (err) return err; - return __inet_bind(sk, uaddr, addr_len, BIND_WITH_LOCK); + return __inet_bind(sk, uaddr, addr_len, flags); } EXPORT_SYMBOL(inet_bind); @@ -499,7 +501,8 @@ int __inet_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len, snum = ntohs(addr->sin_port); err = -EACCES; - if (snum && inet_port_requires_bind_service(net, snum) && + if (!(flags & BIND_NO_CAP_NET_BIND_SERVICE) && + snum && inet_port_requires_bind_service(net, snum) && !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE)) goto out; diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c index b9c654836b72..f091fe9b4da5 100644 --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -295,7 +295,8 @@ static int __inet6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len, return -EINVAL; snum = ntohs(addr->sin6_port); - if (snum && inet_port_requires_bind_service(net, snum) && + if (!(flags & BIND_NO_CAP_NET_BIND_SERVICE) && + snum && inet_port_requires_bind_service(net, snum) && !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE)) return -EACCES; @@ -439,6 +440,7 @@ out_unlock: int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) { struct sock *sk = sock->sk; + u32 flags = BIND_WITH_LOCK; int err = 0; /* If the socket has its own bind function then use it. */ @@ -451,11 +453,12 @@ int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) /* BPF prog is run before any checks are done so that if the prog * changes context in a wrong way it will be caught. */ - err = BPF_CGROUP_RUN_PROG_INET6_BIND_LOCK(sk, uaddr); + err = BPF_CGROUP_RUN_PROG_INET_BIND_LOCK(sk, uaddr, + BPF_CGROUP_INET6_BIND, &flags); if (err) return err; - return __inet6_bind(sk, uaddr, addr_len, BIND_WITH_LOCK); + return __inet6_bind(sk, uaddr, addr_len, flags); } EXPORT_SYMBOL(inet6_bind); -- cgit v1.2.3 From 62476cc1bf24b34d9442c7ba76e5eb6bf242f911 Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Wed, 27 Jan 2021 15:28:50 -0800 Subject: bpf: Enable bpf_{g,s}etsockopt in BPF_CGROUP_UDP{4,6}_SENDMSG Can be used to query/modify socket state for unconnected UDP sendmsg. Those hooks run as BPF_CGROUP_RUN_SA_PROG_LOCK and operate on a locked socket. Signed-off-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20210127232853.3753823-2-sdf@google.com --- net/core/filter.c | 4 ++++ tools/testing/selftests/bpf/bpf_sockopt_helpers.h | 21 +++++++++++++++++++++ tools/testing/selftests/bpf/progs/sendmsg4_prog.c | 7 +++++++ tools/testing/selftests/bpf/progs/sendmsg6_prog.c | 5 +++++ 4 files changed, 37 insertions(+) create mode 100644 tools/testing/selftests/bpf/bpf_sockopt_helpers.h (limited to 'net') diff --git a/net/core/filter.c b/net/core/filter.c index 9ab94e90d660..3d7f78a19565 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -7023,6 +7023,8 @@ sock_addr_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) case BPF_CGROUP_INET6_BIND: case BPF_CGROUP_INET4_CONNECT: case BPF_CGROUP_INET6_CONNECT: + case BPF_CGROUP_UDP4_SENDMSG: + case BPF_CGROUP_UDP6_SENDMSG: return &bpf_sock_addr_setsockopt_proto; default: return NULL; @@ -7033,6 +7035,8 @@ sock_addr_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) case BPF_CGROUP_INET6_BIND: case BPF_CGROUP_INET4_CONNECT: case BPF_CGROUP_INET6_CONNECT: + case BPF_CGROUP_UDP4_SENDMSG: + case BPF_CGROUP_UDP6_SENDMSG: return &bpf_sock_addr_getsockopt_proto; default: return NULL; diff --git a/tools/testing/selftests/bpf/bpf_sockopt_helpers.h b/tools/testing/selftests/bpf/bpf_sockopt_helpers.h new file mode 100644 index 000000000000..11f3a0976174 --- /dev/null +++ b/tools/testing/selftests/bpf/bpf_sockopt_helpers.h @@ -0,0 +1,21 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#include +#include + +int get_set_sk_priority(void *ctx) +{ + int prio; + + /* Verify that context allows calling bpf_getsockopt and + * bpf_setsockopt by reading and writing back socket + * priority. + */ + + if (bpf_getsockopt(ctx, SOL_SOCKET, SO_PRIORITY, &prio, sizeof(prio))) + return 0; + if (bpf_setsockopt(ctx, SOL_SOCKET, SO_PRIORITY, &prio, sizeof(prio))) + return 0; + + return 1; +} diff --git a/tools/testing/selftests/bpf/progs/sendmsg4_prog.c b/tools/testing/selftests/bpf/progs/sendmsg4_prog.c index 092d9da536f3..ac5abc34cde8 100644 --- a/tools/testing/selftests/bpf/progs/sendmsg4_prog.c +++ b/tools/testing/selftests/bpf/progs/sendmsg4_prog.c @@ -8,6 +8,8 @@ #include #include +#include + #define SRC1_IP4 0xAC100001U /* 172.16.0.1 */ #define SRC2_IP4 0x00000000U #define SRC_REWRITE_IP4 0x7f000004U @@ -21,9 +23,14 @@ int _version SEC("version") = 1; SEC("cgroup/sendmsg4") int sendmsg_v4_prog(struct bpf_sock_addr *ctx) { + int prio; + if (ctx->type != SOCK_DGRAM) return 0; + if (!get_set_sk_priority(ctx)) + return 0; + /* Rewrite source. */ if (ctx->msg_src_ip4 == bpf_htonl(SRC1_IP4) || ctx->msg_src_ip4 == bpf_htonl(SRC2_IP4)) { diff --git a/tools/testing/selftests/bpf/progs/sendmsg6_prog.c b/tools/testing/selftests/bpf/progs/sendmsg6_prog.c index 255a432bc163..24694b1a8d82 100644 --- a/tools/testing/selftests/bpf/progs/sendmsg6_prog.c +++ b/tools/testing/selftests/bpf/progs/sendmsg6_prog.c @@ -8,6 +8,8 @@ #include #include +#include + #define SRC_REWRITE_IP6_0 0 #define SRC_REWRITE_IP6_1 0 #define SRC_REWRITE_IP6_2 0 @@ -28,6 +30,9 @@ int sendmsg_v6_prog(struct bpf_sock_addr *ctx) if (ctx->type != SOCK_DGRAM) return 0; + if (!get_set_sk_priority(ctx)) + return 0; + /* Rewrite source. */ if (ctx->msg_src_ip6[3] == bpf_htonl(1) || ctx->msg_src_ip6[3] == bpf_htonl(0)) { -- cgit v1.2.3 From 073f4ec124bb2c431d9e4136e7f583abfea7f290 Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Wed, 27 Jan 2021 15:28:51 -0800 Subject: bpf: Enable bpf_{g,s}etsockopt in BPF_CGROUP_INET{4,6}_GET{PEER,SOCK}NAME Those hooks run as BPF_CGROUP_RUN_SA_PROG_LOCK and operate on a locked socket. Signed-off-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20210127232853.3753823-3-sdf@google.com --- net/core/filter.c | 8 ++++++++ tools/testing/selftests/bpf/progs/connect_force_port4.c | 8 ++++++++ tools/testing/selftests/bpf/progs/connect_force_port6.c | 8 ++++++++ 3 files changed, 24 insertions(+) (limited to 'net') diff --git a/net/core/filter.c b/net/core/filter.c index 3d7f78a19565..ba436b1d70c2 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -7025,6 +7025,10 @@ sock_addr_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) case BPF_CGROUP_INET6_CONNECT: case BPF_CGROUP_UDP4_SENDMSG: case BPF_CGROUP_UDP6_SENDMSG: + case BPF_CGROUP_INET4_GETPEERNAME: + case BPF_CGROUP_INET6_GETPEERNAME: + case BPF_CGROUP_INET4_GETSOCKNAME: + case BPF_CGROUP_INET6_GETSOCKNAME: return &bpf_sock_addr_setsockopt_proto; default: return NULL; @@ -7037,6 +7041,10 @@ sock_addr_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) case BPF_CGROUP_INET6_CONNECT: case BPF_CGROUP_UDP4_SENDMSG: case BPF_CGROUP_UDP6_SENDMSG: + case BPF_CGROUP_INET4_GETPEERNAME: + case BPF_CGROUP_INET6_GETPEERNAME: + case BPF_CGROUP_INET4_GETSOCKNAME: + case BPF_CGROUP_INET6_GETSOCKNAME: return &bpf_sock_addr_getsockopt_proto; default: return NULL; diff --git a/tools/testing/selftests/bpf/progs/connect_force_port4.c b/tools/testing/selftests/bpf/progs/connect_force_port4.c index 7396308677a3..a979aaef2a76 100644 --- a/tools/testing/selftests/bpf/progs/connect_force_port4.c +++ b/tools/testing/selftests/bpf/progs/connect_force_port4.c @@ -10,6 +10,8 @@ #include #include +#include + char _license[] SEC("license") = "GPL"; int _version SEC("version") = 1; @@ -58,6 +60,9 @@ int connect4(struct bpf_sock_addr *ctx) SEC("cgroup/getsockname4") int getsockname4(struct bpf_sock_addr *ctx) { + if (!get_set_sk_priority(ctx)) + return 1; + /* Expose local server as 1.2.3.4:60000 to client. */ if (ctx->user_port == bpf_htons(60123)) { ctx->user_ip4 = bpf_htonl(0x01020304); @@ -71,6 +76,9 @@ int getpeername4(struct bpf_sock_addr *ctx) { struct svc_addr *orig; + if (!get_set_sk_priority(ctx)) + return 1; + /* Expose service 1.2.3.4:60000 as peer instead of backend. */ if (ctx->user_port == bpf_htons(60123)) { orig = bpf_sk_storage_get(&service_mapping, ctx->sk, 0, 0); diff --git a/tools/testing/selftests/bpf/progs/connect_force_port6.c b/tools/testing/selftests/bpf/progs/connect_force_port6.c index c1a2b555e9ad..afc8f1c5a9d6 100644 --- a/tools/testing/selftests/bpf/progs/connect_force_port6.c +++ b/tools/testing/selftests/bpf/progs/connect_force_port6.c @@ -9,6 +9,8 @@ #include #include +#include + char _license[] SEC("license") = "GPL"; int _version SEC("version") = 1; @@ -63,6 +65,9 @@ int connect6(struct bpf_sock_addr *ctx) SEC("cgroup/getsockname6") int getsockname6(struct bpf_sock_addr *ctx) { + if (!get_set_sk_priority(ctx)) + return 1; + /* Expose local server as [fc00::1]:60000 to client. */ if (ctx->user_port == bpf_htons(60124)) { ctx->user_ip6[0] = bpf_htonl(0xfc000000); @@ -79,6 +84,9 @@ int getpeername6(struct bpf_sock_addr *ctx) { struct svc_addr *orig; + if (!get_set_sk_priority(ctx)) + return 1; + /* Expose service [fc00::1]:60000 as peer instead of backend. */ if (ctx->user_port == bpf_htons(60124)) { orig = bpf_sk_storage_get(&service_mapping, ctx->sk, 0, 0); -- cgit v1.2.3 From 4c3384d7abe58a68d78fd1b8b3bffbf62e1e29a1 Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Wed, 27 Jan 2021 15:28:53 -0800 Subject: bpf: Enable bpf_{g,s}etsockopt in BPF_CGROUP_UDP{4,6}_RECVMSG Those hooks run as BPF_CGROUP_RUN_SA_PROG_LOCK and operate on a locked socket. Note that we could remove the switch for prog->expected_attach_type altogether since all current sock_addr attach types are covered. However, it makes sense to keep it as a safe-guard in case new sock_addr attach types are added that might not operate on a locked socket. Therefore, avoid to let this slip through. Signed-off-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20210127232853.3753823-5-sdf@google.com --- net/core/filter.c | 4 ++++ tools/testing/selftests/bpf/progs/recvmsg4_prog.c | 5 +++++ tools/testing/selftests/bpf/progs/recvmsg6_prog.c | 5 +++++ 3 files changed, 14 insertions(+) (limited to 'net') diff --git a/net/core/filter.c b/net/core/filter.c index ba436b1d70c2..e15d4741719a 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -7023,6 +7023,8 @@ sock_addr_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) case BPF_CGROUP_INET6_BIND: case BPF_CGROUP_INET4_CONNECT: case BPF_CGROUP_INET6_CONNECT: + case BPF_CGROUP_UDP4_RECVMSG: + case BPF_CGROUP_UDP6_RECVMSG: case BPF_CGROUP_UDP4_SENDMSG: case BPF_CGROUP_UDP6_SENDMSG: case BPF_CGROUP_INET4_GETPEERNAME: @@ -7039,6 +7041,8 @@ sock_addr_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) case BPF_CGROUP_INET6_BIND: case BPF_CGROUP_INET4_CONNECT: case BPF_CGROUP_INET6_CONNECT: + case BPF_CGROUP_UDP4_RECVMSG: + case BPF_CGROUP_UDP6_RECVMSG: case BPF_CGROUP_UDP4_SENDMSG: case BPF_CGROUP_UDP6_SENDMSG: case BPF_CGROUP_INET4_GETPEERNAME: diff --git a/tools/testing/selftests/bpf/progs/recvmsg4_prog.c b/tools/testing/selftests/bpf/progs/recvmsg4_prog.c index fc2fe8a952fa..3d1ae8b3402f 100644 --- a/tools/testing/selftests/bpf/progs/recvmsg4_prog.c +++ b/tools/testing/selftests/bpf/progs/recvmsg4_prog.c @@ -8,6 +8,8 @@ #include #include +#include + #define SERV4_IP 0xc0a801feU /* 192.168.1.254 */ #define SERV4_PORT 4040 @@ -28,6 +30,9 @@ int recvmsg4_prog(struct bpf_sock_addr *ctx) if (ctx->type != SOCK_STREAM && ctx->type != SOCK_DGRAM) return 1; + if (!get_set_sk_priority(ctx)) + return 1; + ctx->user_ip4 = bpf_htonl(SERV4_IP); ctx->user_port = bpf_htons(SERV4_PORT); diff --git a/tools/testing/selftests/bpf/progs/recvmsg6_prog.c b/tools/testing/selftests/bpf/progs/recvmsg6_prog.c index 6060fd63324b..27dfb21b21b4 100644 --- a/tools/testing/selftests/bpf/progs/recvmsg6_prog.c +++ b/tools/testing/selftests/bpf/progs/recvmsg6_prog.c @@ -8,6 +8,8 @@ #include #include +#include + #define SERV6_IP_0 0xfaceb00c /* face:b00c:1234:5678::abcd */ #define SERV6_IP_1 0x12345678 #define SERV6_IP_2 0x00000000 @@ -31,6 +33,9 @@ int recvmsg6_prog(struct bpf_sock_addr *ctx) if (ctx->type != SOCK_STREAM && ctx->type != SOCK_DGRAM) return 1; + if (!get_set_sk_priority(ctx)) + return 1; + ctx->user_ip6[0] = bpf_htonl(SERV6_IP_0); ctx->user_ip6[1] = bpf_htonl(SERV6_IP_1); ctx->user_ip6[2] = bpf_htonl(SERV6_IP_2); -- cgit v1.2.3 From 65e6dcf73398ddb64bb782ff2acd918d3a37a53a Mon Sep 17 00:00:00 2001 From: Lorenzo Bianconi Date: Fri, 29 Jan 2021 23:04:08 +0100 Subject: net, veth: Alloc skb in bulk for ndo_xdp_xmit Split ndo_xdp_xmit and ndo_start_xmit use cases in veth_xdp_rcv routine in order to alloc skbs in bulk for XDP_PASS verdict. Introduce xdp_alloc_skb_bulk utility routine to alloc skb bulk list. The proposed approach has been tested in the following scenario: eth (ixgbe) --> XDP_REDIRECT --> veth0 --> (remote-ns) veth1 --> XDP_PASS XDP_REDIRECT: xdp_redirect_map bpf sample XDP_PASS: xdp_rxq_info bpf sample traffic generator: pkt_gen sending udp traffic on a remote device bpf-next master: ~3.64Mpps bpf-next + skb bulking allocation: ~3.79Mpps Signed-off-by: Lorenzo Bianconi Signed-off-by: Daniel Borkmann Reviewed-by: Toshiaki Makita Acked-by: Jesper Dangaard Brouer Link: https://lore.kernel.org/bpf/a14a30d3c06fff24e13f836c733d80efc0bd6eb5.1611957532.git.lorenzo@kernel.org --- drivers/net/veth.c | 78 ++++++++++++++++++++++++++++++++++++++++-------------- include/net/xdp.h | 1 + net/core/xdp.c | 11 ++++++++ 3 files changed, 70 insertions(+), 20 deletions(-) (limited to 'net') diff --git a/drivers/net/veth.c b/drivers/net/veth.c index 6e03b619c93c..aa1a66ad2ce5 100644 --- a/drivers/net/veth.c +++ b/drivers/net/veth.c @@ -35,6 +35,7 @@ #define VETH_XDP_HEADROOM (XDP_PACKET_HEADROOM + NET_IP_ALIGN) #define VETH_XDP_TX_BULK_SIZE 16 +#define VETH_XDP_BATCH 16 struct veth_stats { u64 rx_drops; @@ -562,14 +563,13 @@ static int veth_xdp_tx(struct veth_rq *rq, struct xdp_buff *xdp, return 0; } -static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq, - struct xdp_frame *frame, - struct veth_xdp_tx_bq *bq, - struct veth_stats *stats) +static struct xdp_frame *veth_xdp_rcv_one(struct veth_rq *rq, + struct xdp_frame *frame, + struct veth_xdp_tx_bq *bq, + struct veth_stats *stats) { struct xdp_frame orig_frame; struct bpf_prog *xdp_prog; - struct sk_buff *skb; rcu_read_lock(); xdp_prog = rcu_dereference(rq->xdp_prog); @@ -623,13 +623,7 @@ static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq, } rcu_read_unlock(); - skb = xdp_build_skb_from_frame(frame, rq->dev); - if (!skb) { - xdp_return_frame(frame); - stats->rx_drops++; - } - - return skb; + return frame; err_xdp: rcu_read_unlock(); xdp_return_frame(frame); @@ -637,6 +631,37 @@ xdp_xmit: return NULL; } +/* frames array contains VETH_XDP_BATCH at most */ +static void veth_xdp_rcv_bulk_skb(struct veth_rq *rq, void **frames, + int n_xdpf, struct veth_xdp_tx_bq *bq, + struct veth_stats *stats) +{ + void *skbs[VETH_XDP_BATCH]; + int i; + + if (xdp_alloc_skb_bulk(skbs, n_xdpf, + GFP_ATOMIC | __GFP_ZERO) < 0) { + for (i = 0; i < n_xdpf; i++) + xdp_return_frame(frames[i]); + stats->rx_drops += n_xdpf; + + return; + } + + for (i = 0; i < n_xdpf; i++) { + struct sk_buff *skb = skbs[i]; + + skb = __xdp_build_skb_from_frame(frames[i], skb, + rq->dev); + if (!skb) { + xdp_return_frame(frames[i]); + stats->rx_drops++; + continue; + } + napi_gro_receive(&rq->xdp_napi, skb); + } +} + static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq, struct sk_buff *skb, struct veth_xdp_tx_bq *bq, @@ -784,32 +809,45 @@ static int veth_xdp_rcv(struct veth_rq *rq, int budget, struct veth_xdp_tx_bq *bq, struct veth_stats *stats) { - int i, done = 0; + int i, done = 0, n_xdpf = 0; + void *xdpf[VETH_XDP_BATCH]; for (i = 0; i < budget; i++) { void *ptr = __ptr_ring_consume(&rq->xdp_ring); - struct sk_buff *skb; if (!ptr) break; if (veth_is_xdp_frame(ptr)) { + /* ndo_xdp_xmit */ struct xdp_frame *frame = veth_ptr_to_xdp(ptr); stats->xdp_bytes += frame->len; - skb = veth_xdp_rcv_one(rq, frame, bq, stats); + frame = veth_xdp_rcv_one(rq, frame, bq, stats); + if (frame) { + /* XDP_PASS */ + xdpf[n_xdpf++] = frame; + if (n_xdpf == VETH_XDP_BATCH) { + veth_xdp_rcv_bulk_skb(rq, xdpf, n_xdpf, + bq, stats); + n_xdpf = 0; + } + } } else { - skb = ptr; + /* ndo_start_xmit */ + struct sk_buff *skb = ptr; + stats->xdp_bytes += skb->len; skb = veth_xdp_rcv_skb(rq, skb, bq, stats); + if (skb) + napi_gro_receive(&rq->xdp_napi, skb); } - - if (skb) - napi_gro_receive(&rq->xdp_napi, skb); - done++; } + if (n_xdpf) + veth_xdp_rcv_bulk_skb(rq, xdpf, n_xdpf, bq, stats); + u64_stats_update_begin(&rq->stats.syncp); rq->stats.vs.xdp_redirect += stats->xdp_redirect; rq->stats.vs.xdp_bytes += stats->xdp_bytes; diff --git a/include/net/xdp.h b/include/net/xdp.h index c4bfdc9a8b79..a5bc214a49d9 100644 --- a/include/net/xdp.h +++ b/include/net/xdp.h @@ -169,6 +169,7 @@ struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf, struct net_device *dev); struct sk_buff *xdp_build_skb_from_frame(struct xdp_frame *xdpf, struct net_device *dev); +int xdp_alloc_skb_bulk(void **skbs, int n_skb, gfp_t gfp); static inline void xdp_convert_frame_to_buff(struct xdp_frame *frame, struct xdp_buff *xdp) diff --git a/net/core/xdp.c b/net/core/xdp.c index 0d2630a35c3e..05354976c1fc 100644 --- a/net/core/xdp.c +++ b/net/core/xdp.c @@ -514,6 +514,17 @@ void xdp_warn(const char *msg, const char *func, const int line) }; EXPORT_SYMBOL_GPL(xdp_warn); +int xdp_alloc_skb_bulk(void **skbs, int n_skb, gfp_t gfp) +{ + n_skb = kmem_cache_alloc_bulk(skbuff_head_cache, gfp, + n_skb, skbs); + if (unlikely(!n_skb)) + return -ENOMEM; + + return 0; +} +EXPORT_SYMBOL_GPL(xdp_alloc_skb_bulk); + struct sk_buff *__xdp_build_skb_from_frame(struct xdp_frame *xdpf, struct sk_buff *skb, struct net_device *dev) -- cgit v1.2.3 From c5dbb89fc2ac013afe67b9e4fcb3743c02b567cd Mon Sep 17 00:00:00 2001 From: Florent Revest Date: Wed, 10 Feb 2021 12:14:03 +0100 Subject: bpf: Expose bpf_get_socket_cookie to tracing programs This needs a new helper that: - can work in a sleepable context (using sock_gen_cookie) - takes a struct sock pointer and checks that it's not NULL Signed-off-by: Florent Revest Signed-off-by: Alexei Starovoitov Acked-by: KP Singh Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20210210111406.785541-2-revest@chromium.org --- include/linux/bpf.h | 1 + include/uapi/linux/bpf.h | 8 ++++++++ kernel/trace/bpf_trace.c | 2 ++ net/core/filter.c | 12 ++++++++++++ tools/include/uapi/linux/bpf.h | 8 ++++++++ 5 files changed, 31 insertions(+) (limited to 'net') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 1c8ea682c007..cccaef1088ea 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1885,6 +1885,7 @@ extern const struct bpf_func_proto bpf_per_cpu_ptr_proto; extern const struct bpf_func_proto bpf_this_cpu_ptr_proto; extern const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto; extern const struct bpf_func_proto bpf_sock_from_file_proto; +extern const struct bpf_func_proto bpf_get_socket_ptr_cookie_proto; const struct bpf_func_proto *bpf_tracing_func_proto( enum bpf_func_id func_id, const struct bpf_prog *prog); diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index dbf10bf08582..07cc2e404291 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -1673,6 +1673,14 @@ union bpf_attr { * Return * A 8-byte long unique number. * + * u64 bpf_get_socket_cookie(struct sock *sk) + * Description + * Equivalent to **bpf_get_socket_cookie**\ () helper that accepts + * *sk*, but gets socket from a BTF **struct sock**. This helper + * also works for sleepable programs. + * Return + * A 8-byte long unique number or 0 if *sk* is NULL. + * * u32 bpf_get_socket_uid(struct sk_buff *skb) * Return * The owner UID of the socket associated to *skb*. If the socket diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 6c0018abe68a..845b2168e006 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1760,6 +1760,8 @@ tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_sk_storage_delete_tracing_proto; case BPF_FUNC_sock_from_file: return &bpf_sock_from_file_proto; + case BPF_FUNC_get_socket_cookie: + return &bpf_get_socket_ptr_cookie_proto; #endif case BPF_FUNC_seq_printf: return prog->expected_attach_type == BPF_TRACE_ITER ? diff --git a/net/core/filter.c b/net/core/filter.c index e15d4741719a..57aaed478362 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4631,6 +4631,18 @@ static const struct bpf_func_proto bpf_get_socket_cookie_sock_proto = { .arg1_type = ARG_PTR_TO_CTX, }; +BPF_CALL_1(bpf_get_socket_ptr_cookie, struct sock *, sk) +{ + return sk ? sock_gen_cookie(sk) : 0; +} + +const struct bpf_func_proto bpf_get_socket_ptr_cookie_proto = { + .func = bpf_get_socket_ptr_cookie, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_BTF_ID_SOCK_COMMON, +}; + BPF_CALL_1(bpf_get_socket_cookie_sock_ops, struct bpf_sock_ops_kern *, ctx) { return __sock_gen_cookie(ctx->sk); diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index dbf10bf08582..07cc2e404291 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -1673,6 +1673,14 @@ union bpf_attr { * Return * A 8-byte long unique number. * + * u64 bpf_get_socket_cookie(struct sock *sk) + * Description + * Equivalent to **bpf_get_socket_cookie**\ () helper that accepts + * *sk*, but gets socket from a BTF **struct sock**. This helper + * also works for sleepable programs. + * Return + * A 8-byte long unique number or 0 if *sk* is NULL. + * * u32 bpf_get_socket_uid(struct sk_buff *skb) * Return * The owner UID of the socket associated to *skb*. If the socket -- cgit v1.2.3 From 6306c1189e77a513bf02720450bb43bd4ba5d8ae Mon Sep 17 00:00:00 2001 From: Jesper Dangaard Brouer Date: Tue, 9 Feb 2021 14:38:09 +0100 Subject: bpf: Remove MTU check in __bpf_skb_max_len Multiple BPF-helpers that can manipulate/increase the size of the SKB uses __bpf_skb_max_len() as the max-length. This function limit size against the current net_device MTU (skb->dev->mtu). When a BPF-prog grow the packet size, then it should not be limited to the MTU. The MTU is a transmit limitation, and software receiving this packet should be allowed to increase the size. Further more, current MTU check in __bpf_skb_max_len uses the MTU from ingress/current net_device, which in case of redirects uses the wrong net_device. This patch keeps a sanity max limit of SKB_MAX_ALLOC (16KiB). The real limit is elsewhere in the system. Jesper's testing[1] showed it was not possible to exceed 8KiB when expanding the SKB size via BPF-helper. The limiting factor is the define KMALLOC_MAX_CACHE_SIZE which is 8192 for SLUB-allocator (CONFIG_SLUB) in-case PAGE_SIZE is 4096. This define is in-effect due to this being called from softirq context see code __gfp_pfmemalloc_flags() and __do_kmalloc_node(). Jakub's testing showed that frames above 16KiB can cause NICs to reset (but not crash). Keep this sanity limit at this level as memory layer can differ based on kernel config. [1] https://github.com/xdp-project/bpf-examples/tree/master/MTU-tests Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Daniel Borkmann Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/161287788936.790810.2937823995775097177.stgit@firesoul --- net/core/filter.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) (limited to 'net') diff --git a/net/core/filter.c b/net/core/filter.c index 57aaed478362..27022168fd78 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -3552,11 +3552,7 @@ static int bpf_skb_net_shrink(struct sk_buff *skb, u32 off, u32 len_diff, return 0; } -static u32 __bpf_skb_max_len(const struct sk_buff *skb) -{ - return skb->dev ? skb->dev->mtu + skb->dev->hard_header_len : - SKB_MAX_ALLOC; -} +#define BPF_SKB_MAX_LEN SKB_MAX_ALLOC BPF_CALL_4(sk_skb_adjust_room, struct sk_buff *, skb, s32, len_diff, u32, mode, u64, flags) @@ -3605,7 +3601,7 @@ BPF_CALL_4(bpf_skb_adjust_room, struct sk_buff *, skb, s32, len_diff, { u32 len_cur, len_diff_abs = abs(len_diff); u32 len_min = bpf_skb_net_base_len(skb); - u32 len_max = __bpf_skb_max_len(skb); + u32 len_max = BPF_SKB_MAX_LEN; __be16 proto = skb->protocol; bool shrink = len_diff < 0; u32 off; @@ -3688,7 +3684,7 @@ static int bpf_skb_trim_rcsum(struct sk_buff *skb, unsigned int new_len) static inline int __bpf_skb_change_tail(struct sk_buff *skb, u32 new_len, u64 flags) { - u32 max_len = __bpf_skb_max_len(skb); + u32 max_len = BPF_SKB_MAX_LEN; u32 min_len = __bpf_skb_min_len(skb); int ret; @@ -3764,7 +3760,7 @@ static const struct bpf_func_proto sk_skb_change_tail_proto = { static inline int __bpf_skb_change_head(struct sk_buff *skb, u32 head_room, u64 flags) { - u32 max_len = __bpf_skb_max_len(skb); + u32 max_len = BPF_SKB_MAX_LEN; u32 new_len = skb->len + head_room; int ret; -- cgit v1.2.3 From 2c0a10af688c02adcf127aad29e923e0056c6b69 Mon Sep 17 00:00:00 2001 From: Jesper Dangaard Brouer Date: Tue, 9 Feb 2021 14:38:14 +0100 Subject: bpf: Fix bpf_fib_lookup helper MTU check for SKB ctx BPF end-user on Cilium slack-channel (Carlo Carraro) wants to use bpf_fib_lookup for doing MTU-check, but *prior* to extending packet size, by adjusting fib_params 'tot_len' with the packet length plus the expected encap size. (Just like the bpf_check_mtu helper supports). He discovered that for SKB ctx the param->tot_len was not used, instead skb->len was used (via MTU check in is_skb_forwardable() that checks against netdev MTU). Fix this by using fib_params 'tot_len' for MTU check. If not provided (e.g. zero) then keep existing TC behaviour intact. Notice that 'tot_len' for MTU check is done like XDP code-path, which checks against FIB-dst MTU. V16: - Revert V13 optimization, 2nd lookup is against egress/resulting netdev V13: - Only do ifindex lookup one time, calling dev_get_by_index_rcu(). V10: - Use same method as XDP for 'tot_len' MTU check Fixes: 4c79579b44b1 ("bpf: Change bpf_fib_lookup to return lookup status") Reported-by: Carlo Carraro Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/161287789444.790810.15247494756551413508.stgit@firesoul --- net/core/filter.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) (limited to 'net') diff --git a/net/core/filter.c b/net/core/filter.c index 27022168fd78..1fec2e998e37 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -5581,6 +5581,7 @@ BPF_CALL_4(bpf_skb_fib_lookup, struct sk_buff *, skb, { struct net *net = dev_net(skb->dev); int rc = -EAFNOSUPPORT; + bool check_mtu = false; if (plen < sizeof(*params)) return -EINVAL; @@ -5588,22 +5589,28 @@ BPF_CALL_4(bpf_skb_fib_lookup, struct sk_buff *, skb, if (flags & ~(BPF_FIB_LOOKUP_DIRECT | BPF_FIB_LOOKUP_OUTPUT)) return -EINVAL; + if (params->tot_len) + check_mtu = true; + switch (params->family) { #if IS_ENABLED(CONFIG_INET) case AF_INET: - rc = bpf_ipv4_fib_lookup(net, params, flags, false); + rc = bpf_ipv4_fib_lookup(net, params, flags, check_mtu); break; #endif #if IS_ENABLED(CONFIG_IPV6) case AF_INET6: - rc = bpf_ipv6_fib_lookup(net, params, flags, false); + rc = bpf_ipv6_fib_lookup(net, params, flags, check_mtu); break; #endif } - if (!rc) { + if (rc == BPF_FIB_LKUP_RET_SUCCESS && !check_mtu) { struct net_device *dev; + /* When tot_len isn't provided by user, check skb + * against MTU of FIB lookup resulting net_device + */ dev = dev_get_by_index_rcu(net, params->ifindex); if (!is_skb_forwardable(dev, skb)) rc = BPF_FIB_LKUP_RET_FRAG_NEEDED; -- cgit v1.2.3 From e1850ea9bd9eca3656820b4875967d6f9c11c237 Mon Sep 17 00:00:00 2001 From: Jesper Dangaard Brouer Date: Tue, 9 Feb 2021 14:38:19 +0100 Subject: bpf: bpf_fib_lookup return MTU value as output when looked up The BPF-helpers for FIB lookup (bpf_xdp_fib_lookup and bpf_skb_fib_lookup) can perform MTU check and return BPF_FIB_LKUP_RET_FRAG_NEEDED. The BPF-prog don't know the MTU value that caused this rejection. If the BPF-prog wants to implement PMTU (Path MTU Discovery) (rfc1191) it need to know this MTU value for the ICMP packet. Patch change lookup and result struct bpf_fib_lookup, to contain this MTU value as output via a union with 'tot_len' as this is the value used for the MTU lookup. V5: - Fixed uninit value spotted by Dan Carpenter. - Name struct output member mtu_result Reported-by: kernel test robot Reported-by: Dan Carpenter Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Daniel Borkmann Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/161287789952.790810.13134700381067698781.stgit@firesoul --- include/uapi/linux/bpf.h | 11 +++++++++-- net/core/filter.c | 22 +++++++++++++++------- tools/include/uapi/linux/bpf.h | 11 +++++++++-- 3 files changed, 33 insertions(+), 11 deletions(-) (limited to 'net') diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 07cc2e404291..6b1f6058cccf 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -2239,6 +2239,9 @@ union bpf_attr { * * > 0 one of **BPF_FIB_LKUP_RET_** codes explaining why the * packet is not forwarded or needs assist from full stack * + * If lookup fails with BPF_FIB_LKUP_RET_FRAG_NEEDED, then the MTU + * was exceeded and output params->mtu_result contains the MTU. + * * long bpf_sock_hash_update(struct bpf_sock_ops *skops, struct bpf_map *map, void *key, u64 flags) * Description * Add an entry to, or update a sockhash *map* referencing sockets. @@ -4990,9 +4993,13 @@ struct bpf_fib_lookup { __be16 sport; __be16 dport; - /* total length of packet from network header - used for MTU check */ - __u16 tot_len; + union { /* used for MTU check */ + /* input to lookup */ + __u16 tot_len; /* L3 length from network hdr (iph->tot_len) */ + /* output: MTU value */ + __u16 mtu_result; + }; /* input: L3 device index for lookup * output: device index from FIB lookup */ diff --git a/net/core/filter.c b/net/core/filter.c index 1fec2e998e37..e7a9b1667dd6 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -5301,12 +5301,14 @@ static const struct bpf_func_proto bpf_skb_get_xfrm_state_proto = { #if IS_ENABLED(CONFIG_INET) || IS_ENABLED(CONFIG_IPV6) static int bpf_fib_set_fwd_params(struct bpf_fib_lookup *params, const struct neighbour *neigh, - const struct net_device *dev) + const struct net_device *dev, u32 mtu) { memcpy(params->dmac, neigh->ha, ETH_ALEN); memcpy(params->smac, dev->dev_addr, ETH_ALEN); params->h_vlan_TCI = 0; params->h_vlan_proto = 0; + if (mtu) + params->mtu_result = mtu; /* union with tot_len */ return 0; } @@ -5322,8 +5324,8 @@ static int bpf_ipv4_fib_lookup(struct net *net, struct bpf_fib_lookup *params, struct net_device *dev; struct fib_result res; struct flowi4 fl4; + u32 mtu = 0; int err; - u32 mtu; dev = dev_get_by_index_rcu(net, params->ifindex); if (unlikely(!dev)) @@ -5390,8 +5392,10 @@ static int bpf_ipv4_fib_lookup(struct net *net, struct bpf_fib_lookup *params, if (check_mtu) { mtu = ip_mtu_from_fib_result(&res, params->ipv4_dst); - if (params->tot_len > mtu) + if (params->tot_len > mtu) { + params->mtu_result = mtu; /* union with tot_len */ return BPF_FIB_LKUP_RET_FRAG_NEEDED; + } } nhc = res.nhc; @@ -5425,7 +5429,7 @@ static int bpf_ipv4_fib_lookup(struct net *net, struct bpf_fib_lookup *params, if (!neigh) return BPF_FIB_LKUP_RET_NO_NEIGH; - return bpf_fib_set_fwd_params(params, neigh, dev); + return bpf_fib_set_fwd_params(params, neigh, dev, mtu); } #endif @@ -5442,7 +5446,7 @@ static int bpf_ipv6_fib_lookup(struct net *net, struct bpf_fib_lookup *params, struct flowi6 fl6; int strict = 0; int oif, err; - u32 mtu; + u32 mtu = 0; /* link local addresses are never forwarded */ if (rt6_need_strict(dst) || rt6_need_strict(src)) @@ -5517,8 +5521,10 @@ static int bpf_ipv6_fib_lookup(struct net *net, struct bpf_fib_lookup *params, if (check_mtu) { mtu = ipv6_stub->ip6_mtu_from_fib6(&res, dst, src); - if (params->tot_len > mtu) + if (params->tot_len > mtu) { + params->mtu_result = mtu; /* union with tot_len */ return BPF_FIB_LKUP_RET_FRAG_NEEDED; + } } if (res.nh->fib_nh_lws) @@ -5538,7 +5544,7 @@ static int bpf_ipv6_fib_lookup(struct net *net, struct bpf_fib_lookup *params, if (!neigh) return BPF_FIB_LKUP_RET_NO_NEIGH; - return bpf_fib_set_fwd_params(params, neigh, dev); + return bpf_fib_set_fwd_params(params, neigh, dev, mtu); } #endif @@ -5614,6 +5620,8 @@ BPF_CALL_4(bpf_skb_fib_lookup, struct sk_buff *, skb, dev = dev_get_by_index_rcu(net, params->ifindex); if (!is_skb_forwardable(dev, skb)) rc = BPF_FIB_LKUP_RET_FRAG_NEEDED; + + params->mtu_result = dev->mtu; /* union with tot_len */ } return rc; diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 07cc2e404291..6b1f6058cccf 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -2239,6 +2239,9 @@ union bpf_attr { * * > 0 one of **BPF_FIB_LKUP_RET_** codes explaining why the * packet is not forwarded or needs assist from full stack * + * If lookup fails with BPF_FIB_LKUP_RET_FRAG_NEEDED, then the MTU + * was exceeded and output params->mtu_result contains the MTU. + * * long bpf_sock_hash_update(struct bpf_sock_ops *skops, struct bpf_map *map, void *key, u64 flags) * Description * Add an entry to, or update a sockhash *map* referencing sockets. @@ -4990,9 +4993,13 @@ struct bpf_fib_lookup { __be16 sport; __be16 dport; - /* total length of packet from network header - used for MTU check */ - __u16 tot_len; + union { /* used for MTU check */ + /* input to lookup */ + __u16 tot_len; /* L3 length from network hdr (iph->tot_len) */ + /* output: MTU value */ + __u16 mtu_result; + }; /* input: L3 device index for lookup * output: device index from FIB lookup */ -- cgit v1.2.3 From 34b2021cc61642d61c3cf943d9e71925b827941b Mon Sep 17 00:00:00 2001 From: Jesper Dangaard Brouer Date: Tue, 9 Feb 2021 14:38:24 +0100 Subject: bpf: Add BPF-helper for MTU checking This BPF-helper bpf_check_mtu() works for both XDP and TC-BPF programs. The SKB object is complex and the skb->len value (accessible from BPF-prog) also include the length of any extra GRO/GSO segments, but without taking into account that these GRO/GSO segments get added transport (L4) and network (L3) headers before being transmitted. Thus, this BPF-helper is created such that the BPF-programmer don't need to handle these details in the BPF-prog. The API is designed to help the BPF-programmer, that want to do packet context size changes, which involves other helpers. These other helpers usually does a delta size adjustment. This helper also support a delta size (len_diff), which allow BPF-programmer to reuse arguments needed by these other helpers, and perform the MTU check prior to doing any actual size adjustment of the packet context. It is on purpose, that we allow the len adjustment to become a negative result, that will pass the MTU check. This might seem weird, but it's not this helpers responsibility to "catch" wrong len_diff adjustments. Other helpers will take care of these checks, if BPF-programmer chooses to do actual size adjustment. V14: - Improve man-page desc of len_diff. V13: - Enforce flag BPF_MTU_CHK_SEGS cannot use len_diff. V12: - Simplify segment check that calls skb_gso_validate_network_len. - Helpers should return long V9: - Use dev->hard_header_len (instead of ETH_HLEN) - Annotate with unlikely req from Daniel - Fix logic error using skb_gso_validate_network_len from Daniel V6: - Took John's advice and dropped BPF_MTU_CHK_RELAX - Returned MTU is kept at L3-level (like fib_lookup) V4: Lot of changes - ifindex 0 now use current netdev for MTU lookup - rename helper from bpf_mtu_check to bpf_check_mtu - fix bug for GSO pkt length (as skb->len is total len) - remove __bpf_len_adj_positive, simply allow negative len adj Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Daniel Borkmann Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/161287790461.790810.3429728639563297353.stgit@firesoul --- include/uapi/linux/bpf.h | 75 +++++++++++++++++++++++++++ net/core/filter.c | 114 +++++++++++++++++++++++++++++++++++++++++ tools/include/uapi/linux/bpf.h | 75 +++++++++++++++++++++++++++ 3 files changed, 264 insertions(+) (limited to 'net') diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 6b1f6058cccf..4c24daa43bac 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -3847,6 +3847,69 @@ union bpf_attr { * Return * A pointer to a struct socket on success or NULL if the file is * not a socket. + * + * long bpf_check_mtu(void *ctx, u32 ifindex, u32 *mtu_len, s32 len_diff, u64 flags) + * Description + + * Check ctx packet size against exceeding MTU of net device (based + * on *ifindex*). This helper will likely be used in combination + * with helpers that adjust/change the packet size. + * + * The argument *len_diff* can be used for querying with a planned + * size change. This allows to check MTU prior to changing packet + * ctx. Providing an *len_diff* adjustment that is larger than the + * actual packet size (resulting in negative packet size) will in + * principle not exceed the MTU, why it is not considered a + * failure. Other BPF-helpers are needed for performing the + * planned size change, why the responsability for catch a negative + * packet size belong in those helpers. + * + * Specifying *ifindex* zero means the MTU check is performed + * against the current net device. This is practical if this isn't + * used prior to redirect. + * + * The Linux kernel route table can configure MTUs on a more + * specific per route level, which is not provided by this helper. + * For route level MTU checks use the **bpf_fib_lookup**\ () + * helper. + * + * *ctx* is either **struct xdp_md** for XDP programs or + * **struct sk_buff** for tc cls_act programs. + * + * The *flags* argument can be a combination of one or more of the + * following values: + * + * **BPF_MTU_CHK_SEGS** + * This flag will only works for *ctx* **struct sk_buff**. + * If packet context contains extra packet segment buffers + * (often knows as GSO skb), then MTU check is harder to + * check at this point, because in transmit path it is + * possible for the skb packet to get re-segmented + * (depending on net device features). This could still be + * a MTU violation, so this flag enables performing MTU + * check against segments, with a different violation + * return code to tell it apart. Check cannot use len_diff. + * + * On return *mtu_len* pointer contains the MTU value of the net + * device. Remember the net device configured MTU is the L3 size, + * which is returned here and XDP and TX length operate at L2. + * Helper take this into account for you, but remember when using + * MTU value in your BPF-code. On input *mtu_len* must be a valid + * pointer and be initialized (to zero), else verifier will reject + * BPF program. + * + * Return + * * 0 on success, and populate MTU value in *mtu_len* pointer. + * + * * < 0 if any input argument is invalid (*mtu_len* not updated) + * + * MTU violations return positive values, but also populate MTU + * value in *mtu_len* pointer, as this can be needed for + * implementing PMTU handing: + * + * * **BPF_MTU_CHK_RET_FRAG_NEEDED** + * * **BPF_MTU_CHK_RET_SEGS_TOOBIG** + * */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -4012,6 +4075,7 @@ union bpf_attr { FN(ktime_get_coarse_ns), \ FN(ima_inode_hash), \ FN(sock_from_file), \ + FN(check_mtu), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper @@ -5045,6 +5109,17 @@ struct bpf_redir_neigh { }; }; +/* bpf_check_mtu flags*/ +enum bpf_check_mtu_flags { + BPF_MTU_CHK_SEGS = (1U << 0), +}; + +enum bpf_check_mtu_ret { + BPF_MTU_CHK_RET_SUCCESS, /* check and lookup successful */ + BPF_MTU_CHK_RET_FRAG_NEEDED, /* fragmentation required to fwd */ + BPF_MTU_CHK_RET_SEGS_TOOBIG, /* GSO re-segmentation needed to fwd */ +}; + enum bpf_task_fd_type { BPF_FD_TYPE_RAW_TRACEPOINT, /* tp name */ BPF_FD_TYPE_TRACEPOINT, /* tp name */ diff --git a/net/core/filter.c b/net/core/filter.c index e7a9b1667dd6..439f43f00483 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -5637,6 +5637,116 @@ static const struct bpf_func_proto bpf_skb_fib_lookup_proto = { .arg4_type = ARG_ANYTHING, }; +static struct net_device *__dev_via_ifindex(struct net_device *dev_curr, + u32 ifindex) +{ + struct net *netns = dev_net(dev_curr); + + /* Non-redirect use-cases can use ifindex=0 and save ifindex lookup */ + if (ifindex == 0) + return dev_curr; + + return dev_get_by_index_rcu(netns, ifindex); +} + +BPF_CALL_5(bpf_skb_check_mtu, struct sk_buff *, skb, + u32, ifindex, u32 *, mtu_len, s32, len_diff, u64, flags) +{ + int ret = BPF_MTU_CHK_RET_FRAG_NEEDED; + struct net_device *dev = skb->dev; + int skb_len, dev_len; + int mtu; + + if (unlikely(flags & ~(BPF_MTU_CHK_SEGS))) + return -EINVAL; + + if (unlikely(flags & BPF_MTU_CHK_SEGS && len_diff)) + return -EINVAL; + + dev = __dev_via_ifindex(dev, ifindex); + if (unlikely(!dev)) + return -ENODEV; + + mtu = READ_ONCE(dev->mtu); + + dev_len = mtu + dev->hard_header_len; + skb_len = skb->len + len_diff; /* minus result pass check */ + if (skb_len <= dev_len) { + ret = BPF_MTU_CHK_RET_SUCCESS; + goto out; + } + /* At this point, skb->len exceed MTU, but as it include length of all + * segments, it can still be below MTU. The SKB can possibly get + * re-segmented in transmit path (see validate_xmit_skb). Thus, user + * must choose if segs are to be MTU checked. + */ + if (skb_is_gso(skb)) { + ret = BPF_MTU_CHK_RET_SUCCESS; + + if (flags & BPF_MTU_CHK_SEGS && + !skb_gso_validate_network_len(skb, mtu)) + ret = BPF_MTU_CHK_RET_SEGS_TOOBIG; + } +out: + /* BPF verifier guarantees valid pointer */ + *mtu_len = mtu; + + return ret; +} + +BPF_CALL_5(bpf_xdp_check_mtu, struct xdp_buff *, xdp, + u32, ifindex, u32 *, mtu_len, s32, len_diff, u64, flags) +{ + struct net_device *dev = xdp->rxq->dev; + int xdp_len = xdp->data_end - xdp->data; + int ret = BPF_MTU_CHK_RET_SUCCESS; + int mtu, dev_len; + + /* XDP variant doesn't support multi-buffer segment check (yet) */ + if (unlikely(flags)) + return -EINVAL; + + dev = __dev_via_ifindex(dev, ifindex); + if (unlikely(!dev)) + return -ENODEV; + + mtu = READ_ONCE(dev->mtu); + + /* Add L2-header as dev MTU is L3 size */ + dev_len = mtu + dev->hard_header_len; + + xdp_len += len_diff; /* minus result pass check */ + if (xdp_len > dev_len) + ret = BPF_MTU_CHK_RET_FRAG_NEEDED; + + /* BPF verifier guarantees valid pointer */ + *mtu_len = mtu; + + return ret; +} + +static const struct bpf_func_proto bpf_skb_check_mtu_proto = { + .func = bpf_skb_check_mtu, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_ANYTHING, + .arg3_type = ARG_PTR_TO_INT, + .arg4_type = ARG_ANYTHING, + .arg5_type = ARG_ANYTHING, +}; + +static const struct bpf_func_proto bpf_xdp_check_mtu_proto = { + .func = bpf_xdp_check_mtu, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_ANYTHING, + .arg3_type = ARG_PTR_TO_INT, + .arg4_type = ARG_ANYTHING, + .arg5_type = ARG_ANYTHING, +}; + #if IS_ENABLED(CONFIG_IPV6_SEG6_BPF) static int bpf_push_seg6_encap(struct sk_buff *skb, u32 type, void *hdr, u32 len) { @@ -7222,6 +7332,8 @@ tc_cls_act_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_get_socket_uid_proto; case BPF_FUNC_fib_lookup: return &bpf_skb_fib_lookup_proto; + case BPF_FUNC_check_mtu: + return &bpf_skb_check_mtu_proto; case BPF_FUNC_sk_fullsock: return &bpf_sk_fullsock_proto; case BPF_FUNC_sk_storage_get: @@ -7291,6 +7403,8 @@ xdp_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_xdp_adjust_tail_proto; case BPF_FUNC_fib_lookup: return &bpf_xdp_fib_lookup_proto; + case BPF_FUNC_check_mtu: + return &bpf_xdp_check_mtu_proto; #ifdef CONFIG_INET case BPF_FUNC_sk_lookup_udp: return &bpf_xdp_sk_lookup_udp_proto; diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 6b1f6058cccf..4c24daa43bac 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -3847,6 +3847,69 @@ union bpf_attr { * Return * A pointer to a struct socket on success or NULL if the file is * not a socket. + * + * long bpf_check_mtu(void *ctx, u32 ifindex, u32 *mtu_len, s32 len_diff, u64 flags) + * Description + + * Check ctx packet size against exceeding MTU of net device (based + * on *ifindex*). This helper will likely be used in combination + * with helpers that adjust/change the packet size. + * + * The argument *len_diff* can be used for querying with a planned + * size change. This allows to check MTU prior to changing packet + * ctx. Providing an *len_diff* adjustment that is larger than the + * actual packet size (resulting in negative packet size) will in + * principle not exceed the MTU, why it is not considered a + * failure. Other BPF-helpers are needed for performing the + * planned size change, why the responsability for catch a negative + * packet size belong in those helpers. + * + * Specifying *ifindex* zero means the MTU check is performed + * against the current net device. This is practical if this isn't + * used prior to redirect. + * + * The Linux kernel route table can configure MTUs on a more + * specific per route level, which is not provided by this helper. + * For route level MTU checks use the **bpf_fib_lookup**\ () + * helper. + * + * *ctx* is either **struct xdp_md** for XDP programs or + * **struct sk_buff** for tc cls_act programs. + * + * The *flags* argument can be a combination of one or more of the + * following values: + * + * **BPF_MTU_CHK_SEGS** + * This flag will only works for *ctx* **struct sk_buff**. + * If packet context contains extra packet segment buffers + * (often knows as GSO skb), then MTU check is harder to + * check at this point, because in transmit path it is + * possible for the skb packet to get re-segmented + * (depending on net device features). This could still be + * a MTU violation, so this flag enables performing MTU + * check against segments, with a different violation + * return code to tell it apart. Check cannot use len_diff. + * + * On return *mtu_len* pointer contains the MTU value of the net + * device. Remember the net device configured MTU is the L3 size, + * which is returned here and XDP and TX length operate at L2. + * Helper take this into account for you, but remember when using + * MTU value in your BPF-code. On input *mtu_len* must be a valid + * pointer and be initialized (to zero), else verifier will reject + * BPF program. + * + * Return + * * 0 on success, and populate MTU value in *mtu_len* pointer. + * + * * < 0 if any input argument is invalid (*mtu_len* not updated) + * + * MTU violations return positive values, but also populate MTU + * value in *mtu_len* pointer, as this can be needed for + * implementing PMTU handing: + * + * * **BPF_MTU_CHK_RET_FRAG_NEEDED** + * * **BPF_MTU_CHK_RET_SEGS_TOOBIG** + * */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -4012,6 +4075,7 @@ union bpf_attr { FN(ktime_get_coarse_ns), \ FN(ima_inode_hash), \ FN(sock_from_file), \ + FN(check_mtu), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper @@ -5045,6 +5109,17 @@ struct bpf_redir_neigh { }; }; +/* bpf_check_mtu flags*/ +enum bpf_check_mtu_flags { + BPF_MTU_CHK_SEGS = (1U << 0), +}; + +enum bpf_check_mtu_ret { + BPF_MTU_CHK_RET_SUCCESS, /* check and lookup successful */ + BPF_MTU_CHK_RET_FRAG_NEEDED, /* fragmentation required to fwd */ + BPF_MTU_CHK_RET_SEGS_TOOBIG, /* GSO re-segmentation needed to fwd */ +}; + enum bpf_task_fd_type { BPF_FD_TYPE_RAW_TRACEPOINT, /* tp name */ BPF_FD_TYPE_TRACEPOINT, /* tp name */ -- cgit v1.2.3 From 5f7d57280c1982d993d5f4ff0edac310f820f607 Mon Sep 17 00:00:00 2001 From: Jesper Dangaard Brouer Date: Tue, 9 Feb 2021 14:38:29 +0100 Subject: bpf: Drop MTU check when doing TC-BPF redirect to ingress The use-case for dropping the MTU check when TC-BPF does redirect to ingress, is described by Eyal Birger in email[0]. The summary is the ability to increase packet size (e.g. with IPv6 headers for NAT64) and ingress redirect packet and let normal netstack fragment packet as needed. [0] https://lore.kernel.org/netdev/CAHsH6Gug-hsLGHQ6N0wtixdOa85LDZ3HNRHVd0opR=19Qo4W4Q@mail.gmail.com/ V15: - missing static for function declaration V9: - Make net_device "up" (IFF_UP) check explicit in skb_do_redirect V4: - Keep net_device "up" (IFF_UP) check. - Adjustment to handle bpf_redirect_peer() helper Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Daniel Borkmann Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/161287790971.790810.11785274340154740591.stgit@firesoul --- include/linux/netdevice.h | 32 ++++++++++++++++++++++++++++++-- net/core/dev.c | 32 ++++++++++++++------------------ net/core/filter.c | 6 +++--- 3 files changed, 47 insertions(+), 23 deletions(-) (limited to 'net') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index ef517254367d..b9bcbfde7849 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3931,14 +3931,42 @@ int xdp_umem_query(struct net_device *dev, u16 queue_id); int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb); int dev_forward_skb(struct net_device *dev, struct sk_buff *skb); +int dev_forward_skb_nomtu(struct net_device *dev, struct sk_buff *skb); bool is_skb_forwardable(const struct net_device *dev, const struct sk_buff *skb); +static __always_inline bool __is_skb_forwardable(const struct net_device *dev, + const struct sk_buff *skb, + const bool check_mtu) +{ + const u32 vlan_hdr_len = 4; /* VLAN_HLEN */ + unsigned int len; + + if (!(dev->flags & IFF_UP)) + return false; + + if (!check_mtu) + return true; + + len = dev->mtu + dev->hard_header_len + vlan_hdr_len; + if (skb->len <= len) + return true; + + /* if TSO is enabled, we don't care about the length as the packet + * could be forwarded without being segmented before + */ + if (skb_is_gso(skb)) + return true; + + return false; +} + static __always_inline int ____dev_forward_skb(struct net_device *dev, - struct sk_buff *skb) + struct sk_buff *skb, + const bool check_mtu) { if (skb_orphan_frags(skb, GFP_ATOMIC) || - unlikely(!is_skb_forwardable(dev, skb))) { + unlikely(!__is_skb_forwardable(dev, skb, check_mtu))) { atomic_long_inc(&dev->rx_dropped); kfree_skb(skb); return NET_RX_DROP; diff --git a/net/core/dev.c b/net/core/dev.c index 07a0347c33fb..8c820fe0eff3 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2194,28 +2194,14 @@ static inline void net_timestamp_set(struct sk_buff *skb) bool is_skb_forwardable(const struct net_device *dev, const struct sk_buff *skb) { - unsigned int len; - - if (!(dev->flags & IFF_UP)) - return false; - - len = dev->mtu + dev->hard_header_len + VLAN_HLEN; - if (skb->len <= len) - return true; - - /* if TSO is enabled, we don't care about the length as the packet - * could be forwarded without being segmented before - */ - if (skb_is_gso(skb)) - return true; - - return false; + return __is_skb_forwardable(dev, skb, true); } EXPORT_SYMBOL_GPL(is_skb_forwardable); -int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb) +static int __dev_forward_skb2(struct net_device *dev, struct sk_buff *skb, + bool check_mtu) { - int ret = ____dev_forward_skb(dev, skb); + int ret = ____dev_forward_skb(dev, skb, check_mtu); if (likely(!ret)) { skb->protocol = eth_type_trans(skb, dev); @@ -2224,6 +2210,11 @@ int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb) return ret; } + +int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb) +{ + return __dev_forward_skb2(dev, skb, true); +} EXPORT_SYMBOL_GPL(__dev_forward_skb); /** @@ -2250,6 +2241,11 @@ int dev_forward_skb(struct net_device *dev, struct sk_buff *skb) } EXPORT_SYMBOL_GPL(dev_forward_skb); +int dev_forward_skb_nomtu(struct net_device *dev, struct sk_buff *skb) +{ + return __dev_forward_skb2(dev, skb, false) ?: netif_rx_internal(skb); +} + static inline int deliver_skb(struct sk_buff *skb, struct packet_type *pt_prev, struct net_device *orig_dev) diff --git a/net/core/filter.c b/net/core/filter.c index 439f43f00483..7059cf604d94 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -2083,13 +2083,13 @@ static const struct bpf_func_proto bpf_csum_level_proto = { static inline int __bpf_rx_skb(struct net_device *dev, struct sk_buff *skb) { - return dev_forward_skb(dev, skb); + return dev_forward_skb_nomtu(dev, skb); } static inline int __bpf_rx_skb_no_mac(struct net_device *dev, struct sk_buff *skb) { - int ret = ____dev_forward_skb(dev, skb); + int ret = ____dev_forward_skb(dev, skb, false); if (likely(!ret)) { skb->dev = dev; @@ -2480,7 +2480,7 @@ int skb_do_redirect(struct sk_buff *skb) goto out_drop; dev = ops->ndo_get_peer_dev(dev); if (unlikely(!dev || - !is_skb_forwardable(dev, skb) || + !(dev->flags & IFF_UP) || net_eq(net, dev_net(dev)))) goto out_drop; skb->dev = dev; -- cgit v1.2.3