From 2585cd62f0986a6e6d9c83363ed6dbcc66bc9f32 Mon Sep 17 00:00:00 2001 From: Lawrence Brakmo Date: Thu, 25 Jan 2018 16:14:05 -0800 Subject: [PATCH 01/12] bpf: Only reply field should be writeable Currently, a sock_ops BPF program can write the op field and all the reply fields (reply and replylong). This is a bug. The op field should not have been writeable and there is currently no way to use replylong field for indices >= 1. This patch enforces that only the reply field (which equals replylong[0]) is writeable. Fixes: 40304b2a1567 ("bpf: BPF support for sock_ops") Signed-off-by: Lawrence Brakmo Acked-by: Yuchung Cheng Signed-off-by: Alexei Starovoitov --- net/core/filter.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/net/core/filter.c b/net/core/filter.c index 18da42a81d0c8..bf9bb755e369c 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -3845,8 +3845,7 @@ static bool sock_ops_is_valid_access(int off, int size, { if (type == BPF_WRITE) { switch (off) { - case offsetof(struct bpf_sock_ops, op) ... - offsetof(struct bpf_sock_ops, replylong[3]): + case offsetof(struct bpf_sock_ops, reply): break; default: return false; From a33de3973488680def6a900e74ec67ba2bef226c Mon Sep 17 00:00:00 2001 From: Lawrence Brakmo Date: Thu, 25 Jan 2018 16:14:06 -0800 Subject: [PATCH 02/12] bpf: Make SOCK_OPS_GET_TCP size independent Make SOCK_OPS_GET_TCP helper macro size independent (before only worked with 4-byte fields. Signed-off-by: Lawrence Brakmo Signed-off-by: Alexei Starovoitov --- net/core/filter.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/net/core/filter.c b/net/core/filter.c index bf9bb755e369c..62e78748d95f6 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4470,9 +4470,10 @@ static u32 sock_ops_convert_ctx_access(enum bpf_access_type type, break; /* Helper macro for adding read access to tcp_sock fields. */ -#define SOCK_OPS_GET_TCP32(FIELD_NAME) \ +#define SOCK_OPS_GET_TCP(FIELD_NAME) \ do { \ - BUILD_BUG_ON(FIELD_SIZEOF(struct tcp_sock, FIELD_NAME) != 4); \ + BUILD_BUG_ON(FIELD_SIZEOF(struct tcp_sock, FIELD_NAME) > \ + FIELD_SIZEOF(struct bpf_sock_ops, FIELD_NAME)); \ *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF( \ struct bpf_sock_ops_kern, \ is_fullsock), \ @@ -4484,16 +4485,18 @@ static u32 sock_ops_convert_ctx_access(enum bpf_access_type type, struct bpf_sock_ops_kern, sk),\ si->dst_reg, si->src_reg, \ offsetof(struct bpf_sock_ops_kern, sk));\ - *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->dst_reg, \ + *insn++ = BPF_LDX_MEM(FIELD_SIZEOF(struct tcp_sock, \ + FIELD_NAME), si->dst_reg, \ + si->dst_reg, \ offsetof(struct tcp_sock, FIELD_NAME)); \ } while (0) case offsetof(struct bpf_sock_ops, snd_cwnd): - SOCK_OPS_GET_TCP32(snd_cwnd); + SOCK_OPS_GET_TCP(snd_cwnd); break; case offsetof(struct bpf_sock_ops, srtt_us): - SOCK_OPS_GET_TCP32(srtt_us); + SOCK_OPS_GET_TCP(srtt_us); break; } return insn - insn_buf; From 34d367c59233464dbd1f07445c4665099a7128ec Mon Sep 17 00:00:00 2001 From: Lawrence Brakmo Date: Thu, 25 Jan 2018 16:14:07 -0800 Subject: [PATCH 03/12] bpf: Make SOCK_OPS_GET_TCP struct independent Changed SOCK_OPS_GET_TCP to SOCK_OPS_GET_FIELD and added 2 arguments so now it can also work with struct sock fields. The first argument is the name of the field in the bpf_sock_ops struct, the 2nd argument is the name of the field in the OBJ struct. Previous: SOCK_OPS_GET_TCP(FIELD_NAME) New: SOCK_OPS_GET_FIELD(BPF_FIELD, OBJ_FIELD, OBJ) Where OBJ is either "struct tcp_sock" or "struct sock" (without quotation). BPF_FIELD is the name of the field in the bpf_sock_ops struct and OBJ_FIELD is the name of the field in the OBJ struct. Although the field names are currently the same, the kernel struct names could change in the future and this change makes it easier to support that. Note that adding access to tcp_sock fields in sock_ops programs does not preclude the tcp_sock fields from being removed as long as we are willing to do one of the following: 1) Return a fixed value (e.x. 0 or 0xffffffff), or 2) Make the verifier fail if that field is accessed (i.e. program fails to load) so the user will know that field is no longer supported. Signed-off-by: Lawrence Brakmo Signed-off-by: Alexei Starovoitov --- net/core/filter.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/net/core/filter.c b/net/core/filter.c index 62e78748d95f6..dbb6d2f60680e 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4469,11 +4469,11 @@ static u32 sock_ops_convert_ctx_access(enum bpf_access_type type, is_fullsock)); break; -/* Helper macro for adding read access to tcp_sock fields. */ -#define SOCK_OPS_GET_TCP(FIELD_NAME) \ +/* Helper macro for adding read access to tcp_sock or sock fields. */ +#define SOCK_OPS_GET_FIELD(BPF_FIELD, OBJ_FIELD, OBJ) \ do { \ - BUILD_BUG_ON(FIELD_SIZEOF(struct tcp_sock, FIELD_NAME) > \ - FIELD_SIZEOF(struct bpf_sock_ops, FIELD_NAME)); \ + BUILD_BUG_ON(FIELD_SIZEOF(OBJ, OBJ_FIELD) > \ + FIELD_SIZEOF(struct bpf_sock_ops, BPF_FIELD)); \ *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF( \ struct bpf_sock_ops_kern, \ is_fullsock), \ @@ -4485,18 +4485,18 @@ static u32 sock_ops_convert_ctx_access(enum bpf_access_type type, struct bpf_sock_ops_kern, sk),\ si->dst_reg, si->src_reg, \ offsetof(struct bpf_sock_ops_kern, sk));\ - *insn++ = BPF_LDX_MEM(FIELD_SIZEOF(struct tcp_sock, \ - FIELD_NAME), si->dst_reg, \ - si->dst_reg, \ - offsetof(struct tcp_sock, FIELD_NAME)); \ + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(OBJ, \ + OBJ_FIELD), \ + si->dst_reg, si->dst_reg, \ + offsetof(OBJ, OBJ_FIELD)); \ } while (0) case offsetof(struct bpf_sock_ops, snd_cwnd): - SOCK_OPS_GET_TCP(snd_cwnd); + SOCK_OPS_GET_FIELD(snd_cwnd, snd_cwnd, struct tcp_sock); break; case offsetof(struct bpf_sock_ops, srtt_us): - SOCK_OPS_GET_TCP(srtt_us); + SOCK_OPS_GET_FIELD(srtt_us, srtt_us, struct tcp_sock); break; } return insn - insn_buf; From b73042b8a28e2603ac178295ab96c876ba5a97a1 Mon Sep 17 00:00:00 2001 From: Lawrence Brakmo Date: Thu, 25 Jan 2018 16:14:08 -0800 Subject: [PATCH 04/12] bpf: Add write access to tcp_sock and sock fields This patch adds a macro, SOCK_OPS_SET_FIELD, for writing to struct tcp_sock or struct sock fields. This required adding a new field "temp" to struct bpf_sock_ops_kern for temporary storage that is used by sock_ops_convert_ctx_access. It is used to store and recover the contents of a register, so the register can be used to store the address of the sk. Since we cannot overwrite the dst_reg because it contains the pointer to ctx, nor the src_reg since it contains the value we want to store, we need an extra register to contain the address of the sk. Also adds the macro SOCK_OPS_GET_OR_SET_FIELD that calls one of the GET or SET macros depending on the value of the TYPE field. Signed-off-by: Lawrence Brakmo Acked-by: Alexei Starovoitov Signed-off-by: Alexei Starovoitov --- include/linux/filter.h | 9 ++++++++ include/net/tcp.h | 2 +- net/core/filter.c | 48 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 58 insertions(+), 1 deletion(-) diff --git a/include/linux/filter.h b/include/linux/filter.h index 425056c7f96ce..daa5a676335fa 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -1007,6 +1007,15 @@ struct bpf_sock_ops_kern { u32 replylong[4]; }; u32 is_fullsock; + u64 temp; /* temp and everything after is not + * initialized to 0 before calling + * the BPF program. New fields that + * should be initialized to 0 should + * be inserted before temp. + * temp is scratch storage used by + * sock_ops_convert_ctx_access + * as temporary storage of a register. + */ }; #endif /* __LINUX_FILTER_H__ */ diff --git a/include/net/tcp.h b/include/net/tcp.h index 5a1d26a185998..6092eaff61cf4 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -2011,7 +2011,7 @@ static inline int tcp_call_bpf(struct sock *sk, int op) struct bpf_sock_ops_kern sock_ops; int ret; - memset(&sock_ops, 0, sizeof(sock_ops)); + memset(&sock_ops, 0, offsetof(struct bpf_sock_ops_kern, temp)); if (sk_fullsock(sk)) { sock_ops.is_fullsock = 1; sock_owned_by_me(sk); diff --git a/net/core/filter.c b/net/core/filter.c index dbb6d2f60680e..c356ec02b1a5d 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4491,6 +4491,54 @@ static u32 sock_ops_convert_ctx_access(enum bpf_access_type type, offsetof(OBJ, OBJ_FIELD)); \ } while (0) +/* Helper macro for adding write access to tcp_sock or sock fields. + * The macro is called with two registers, dst_reg which contains a pointer + * to ctx (context) and src_reg which contains the value that should be + * stored. However, we need an additional register since we cannot overwrite + * dst_reg because it may be used later in the program. + * Instead we "borrow" one of the other register. We first save its value + * into a new (temp) field in bpf_sock_ops_kern, use it, and then restore + * it at the end of the macro. + */ +#define SOCK_OPS_SET_FIELD(BPF_FIELD, OBJ_FIELD, OBJ) \ + do { \ + int reg = BPF_REG_9; \ + BUILD_BUG_ON(FIELD_SIZEOF(OBJ, OBJ_FIELD) > \ + FIELD_SIZEOF(struct bpf_sock_ops, BPF_FIELD)); \ + if (si->dst_reg == reg || si->src_reg == reg) \ + reg--; \ + if (si->dst_reg == reg || si->src_reg == reg) \ + reg--; \ + *insn++ = BPF_STX_MEM(BPF_DW, si->dst_reg, reg, \ + offsetof(struct bpf_sock_ops_kern, \ + temp)); \ + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF( \ + struct bpf_sock_ops_kern, \ + is_fullsock), \ + reg, si->dst_reg, \ + offsetof(struct bpf_sock_ops_kern, \ + is_fullsock)); \ + *insn++ = BPF_JMP_IMM(BPF_JEQ, reg, 0, 2); \ + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF( \ + struct bpf_sock_ops_kern, sk),\ + reg, si->dst_reg, \ + offsetof(struct bpf_sock_ops_kern, sk));\ + *insn++ = BPF_STX_MEM(BPF_FIELD_SIZEOF(OBJ, OBJ_FIELD), \ + reg, si->src_reg, \ + offsetof(OBJ, OBJ_FIELD)); \ + *insn++ = BPF_LDX_MEM(BPF_DW, reg, si->dst_reg, \ + offsetof(struct bpf_sock_ops_kern, \ + temp)); \ + } while (0) + +#define SOCK_OPS_GET_OR_SET_FIELD(BPF_FIELD, OBJ_FIELD, OBJ, TYPE) \ + do { \ + if (TYPE == BPF_WRITE) \ + SOCK_OPS_SET_FIELD(BPF_FIELD, OBJ_FIELD, OBJ); \ + else \ + SOCK_OPS_GET_FIELD(BPF_FIELD, OBJ_FIELD, OBJ); \ + } while (0) + case offsetof(struct bpf_sock_ops, snd_cwnd): SOCK_OPS_GET_FIELD(snd_cwnd, snd_cwnd, struct tcp_sock); break; From de525be2ca2734865d29c4b67ddd29913b214906 Mon Sep 17 00:00:00 2001 From: Lawrence Brakmo Date: Thu, 25 Jan 2018 16:14:09 -0800 Subject: [PATCH 05/12] bpf: Support passing args to sock_ops bpf function Adds support for passing up to 4 arguments to sock_ops bpf functions. It reusues the reply union, so the bpf_sock_ops structures are not increased in size. Signed-off-by: Lawrence Brakmo Signed-off-by: Alexei Starovoitov --- include/linux/filter.h | 1 + include/net/tcp.h | 40 +++++++++++++++++++++++++++++++++++----- include/uapi/linux/bpf.h | 5 +++-- net/ipv4/tcp.c | 2 +- net/ipv4/tcp_nv.c | 2 +- net/ipv4/tcp_output.c | 2 +- 6 files changed, 42 insertions(+), 10 deletions(-) diff --git a/include/linux/filter.h b/include/linux/filter.h index daa5a676335fa..20384c4bed25e 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -1003,6 +1003,7 @@ struct bpf_sock_ops_kern { struct sock *sk; u32 op; union { + u32 args[4]; u32 reply; u32 replylong[4]; }; diff --git a/include/net/tcp.h b/include/net/tcp.h index 6092eaff61cf4..093e967a29600 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -2006,7 +2006,7 @@ void tcp_cleanup_ulp(struct sock *sk); * program loaded). */ #ifdef CONFIG_BPF -static inline int tcp_call_bpf(struct sock *sk, int op) +static inline int tcp_call_bpf(struct sock *sk, int op, u32 nargs, u32 *args) { struct bpf_sock_ops_kern sock_ops; int ret; @@ -2019,6 +2019,8 @@ static inline int tcp_call_bpf(struct sock *sk, int op) sock_ops.sk = sk; sock_ops.op = op; + if (nargs > 0) + memcpy(sock_ops.args, args, nargs * sizeof(*args)); ret = BPF_CGROUP_RUN_PROG_SOCK_OPS(&sock_ops); if (ret == 0) @@ -2027,18 +2029,46 @@ static inline int tcp_call_bpf(struct sock *sk, int op) ret = -1; return ret; } + +static inline int tcp_call_bpf_2arg(struct sock *sk, int op, u32 arg1, u32 arg2) +{ + u32 args[2] = {arg1, arg2}; + + return tcp_call_bpf(sk, op, 2, args); +} + +static inline int tcp_call_bpf_3arg(struct sock *sk, int op, u32 arg1, u32 arg2, + u32 arg3) +{ + u32 args[3] = {arg1, arg2, arg3}; + + return tcp_call_bpf(sk, op, 3, args); +} + #else -static inline int tcp_call_bpf(struct sock *sk, int op) +static inline int tcp_call_bpf(struct sock *sk, int op, u32 nargs, u32 *args) { return -EPERM; } + +static inline int tcp_call_bpf_2arg(struct sock *sk, int op, u32 arg1, u32 arg2) +{ + return -EPERM; +} + +static inline int tcp_call_bpf_3arg(struct sock *sk, int op, u32 arg1, u32 arg2, + u32 arg3) +{ + return -EPERM; +} + #endif static inline u32 tcp_timeout_init(struct sock *sk) { int timeout; - timeout = tcp_call_bpf(sk, BPF_SOCK_OPS_TIMEOUT_INIT); + timeout = tcp_call_bpf(sk, BPF_SOCK_OPS_TIMEOUT_INIT, 0, NULL); if (timeout <= 0) timeout = TCP_TIMEOUT_INIT; @@ -2049,7 +2079,7 @@ static inline u32 tcp_rwnd_init_bpf(struct sock *sk) { int rwnd; - rwnd = tcp_call_bpf(sk, BPF_SOCK_OPS_RWND_INIT); + rwnd = tcp_call_bpf(sk, BPF_SOCK_OPS_RWND_INIT, 0, NULL); if (rwnd < 0) rwnd = 0; @@ -2058,7 +2088,7 @@ static inline u32 tcp_rwnd_init_bpf(struct sock *sk) static inline bool tcp_bpf_ca_needs_ecn(struct sock *sk) { - return (tcp_call_bpf(sk, BPF_SOCK_OPS_NEEDS_ECN) == 1); + return (tcp_call_bpf(sk, BPF_SOCK_OPS_NEEDS_ECN, 0, NULL) == 1); } #if IS_ENABLED(CONFIG_SMC) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 406c19d6016b2..8d5874c2c4ff2 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -952,8 +952,9 @@ struct bpf_map_info { struct bpf_sock_ops { __u32 op; union { - __u32 reply; - __u32 replylong[4]; + __u32 args[4]; /* Optionally passed to bpf program */ + __u32 reply; /* Returned by bpf program */ + __u32 replylong[4]; /* Optionally returned by bpf prog */ }; __u32 family; __u32 remote_ip4; /* Stored in network byte order */ diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index d7cf861bf699f..88b62441e7e96 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -463,7 +463,7 @@ void tcp_init_transfer(struct sock *sk, int bpf_op) tcp_mtup_init(sk); icsk->icsk_af_ops->rebuild_header(sk); tcp_init_metrics(sk); - tcp_call_bpf(sk, bpf_op); + tcp_call_bpf(sk, bpf_op, 0, NULL); tcp_init_congestion_control(sk); tcp_init_buffer_space(sk); } diff --git a/net/ipv4/tcp_nv.c b/net/ipv4/tcp_nv.c index 0b5a05bd82e35..ddbce73edae89 100644 --- a/net/ipv4/tcp_nv.c +++ b/net/ipv4/tcp_nv.c @@ -146,7 +146,7 @@ static void tcpnv_init(struct sock *sk) * within a datacenter, where we have reasonable estimates of * RTTs */ - base_rtt = tcp_call_bpf(sk, BPF_SOCK_OPS_BASE_RTT); + base_rtt = tcp_call_bpf(sk, BPF_SOCK_OPS_BASE_RTT, 0, NULL); if (base_rtt > 0) { ca->nv_base_rtt = base_rtt; ca->nv_lower_bound_rtt = (base_rtt * 205) >> 8; /* 80% */ diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 95461f02ac9a2..d12f7f71c1c40 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -3469,7 +3469,7 @@ int tcp_connect(struct sock *sk) struct sk_buff *buff; int err; - tcp_call_bpf(sk, BPF_SOCK_OPS_TCP_CONNECT_CB); + tcp_call_bpf(sk, BPF_SOCK_OPS_TCP_CONNECT_CB, 0, NULL); if (inet_csk(sk)->icsk_af_ops->rebuild_header(sk)) return -EHOSTUNREACH; /* Routing failure or similar. */ From b13d880721729384757f235166068c315326f4a1 Mon Sep 17 00:00:00 2001 From: Lawrence Brakmo Date: Thu, 25 Jan 2018 16:14:10 -0800 Subject: [PATCH 06/12] bpf: Adds field bpf_sock_ops_cb_flags to tcp_sock Adds field bpf_sock_ops_cb_flags to tcp_sock and bpf_sock_ops. Its primary use is to determine if there should be calls to sock_ops bpf program at various points in the TCP code. The field is initialized to zero, disabling the calls. A sock_ops BPF program can set it, per connection and as necessary, when the connection is established. It also adds support for reading and writting the field within a sock_ops BPF program. Reading is done by accessing the field directly. However, writing is done through the helper function bpf_sock_ops_cb_flags_set, in order to return an error if a BPF program is trying to set a callback that is not supported in the current kernel (i.e. running an older kernel). The helper function returns 0 if it was able to set all of the bits set in the argument, a positive number containing the bits that could not be set, or -EINVAL if the socket is not a full TCP socket. Examples of where one could call the bpf program: 1) When RTO fires 2) When a packet is retransmitted 3) When the connection terminates 4) When a packet is sent 5) When a packet is received Signed-off-by: Lawrence Brakmo Acked-by: Alexei Starovoitov Signed-off-by: Alexei Starovoitov --- include/linux/tcp.h | 11 +++++++++++ include/uapi/linux/bpf.h | 17 ++++++++++++++++- net/core/filter.c | 34 ++++++++++++++++++++++++++++++++++ 3 files changed, 61 insertions(+), 1 deletion(-) diff --git a/include/linux/tcp.h b/include/linux/tcp.h index 4f93f0953c411..8f4c54986f974 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -335,6 +335,17 @@ struct tcp_sock { int linger2; + +/* Sock_ops bpf program related variables */ +#ifdef CONFIG_BPF + u8 bpf_sock_ops_cb_flags; /* Control calling BPF programs + * values defined in uapi/linux/tcp.h + */ +#define BPF_SOCK_OPS_TEST_FLAG(TP, ARG) (TP->bpf_sock_ops_cb_flags & ARG) +#else +#define BPF_SOCK_OPS_TEST_FLAG(TP, ARG) 0 +#endif + /* Receiver side RTT estimation */ struct { u32 rtt_us; diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 8d5874c2c4ff2..aa128407c44db 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -642,6 +642,14 @@ union bpf_attr { * @optlen: length of optval in bytes * Return: 0 or negative error * + * int bpf_sock_ops_cb_flags_set(bpf_sock_ops, flags) + * Set callback flags for sock_ops + * @bpf_sock_ops: pointer to bpf_sock_ops_kern struct + * @flags: flags value + * Return: 0 for no error + * -EINVAL if there is no full tcp socket + * bits in flags that are not supported by current kernel + * * int bpf_skb_adjust_room(skb, len_diff, mode, flags) * Grow or shrink room in sk_buff. * @skb: pointer to skb @@ -748,7 +756,8 @@ union bpf_attr { FN(perf_event_read_value), \ FN(perf_prog_read_value), \ FN(getsockopt), \ - FN(override_return), + FN(override_return), \ + FN(sock_ops_cb_flags_set), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call @@ -969,8 +978,14 @@ struct bpf_sock_ops { */ __u32 snd_cwnd; __u32 srtt_us; /* Averaged RTT << 3 in usecs */ + __u32 bpf_sock_ops_cb_flags; /* flags defined in uapi/linux/tcp.h */ }; +/* Definitions for bpf_sock_ops_cb_flags */ +#define BPF_SOCK_OPS_ALL_CB_FLAGS 0 /* Mask of all currently + * supported cb flags + */ + /* List of known BPF sock_ops operators. * New entries can only be added at the end */ diff --git a/net/core/filter.c b/net/core/filter.c index c356ec02b1a5d..6936d19ac7365 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -3328,6 +3328,33 @@ static const struct bpf_func_proto bpf_getsockopt_proto = { .arg5_type = ARG_CONST_SIZE, }; +BPF_CALL_2(bpf_sock_ops_cb_flags_set, struct bpf_sock_ops_kern *, bpf_sock, + int, argval) +{ + struct sock *sk = bpf_sock->sk; + int val = argval & BPF_SOCK_OPS_ALL_CB_FLAGS; + + if (!sk_fullsock(sk)) + return -EINVAL; + +#ifdef CONFIG_INET + if (val) + tcp_sk(sk)->bpf_sock_ops_cb_flags = val; + + return argval & (~BPF_SOCK_OPS_ALL_CB_FLAGS); +#else + return -EINVAL; +#endif +} + +static const struct bpf_func_proto bpf_sock_ops_cb_flags_set_proto = { + .func = bpf_sock_ops_cb_flags_set, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_ANYTHING, +}; + static const struct bpf_func_proto * bpf_base_func_proto(enum bpf_func_id func_id) { @@ -3510,6 +3537,8 @@ static const struct bpf_func_proto * return &bpf_setsockopt_proto; case BPF_FUNC_getsockopt: return &bpf_getsockopt_proto; + case BPF_FUNC_sock_ops_cb_flags_set: + return &bpf_sock_ops_cb_flags_set_proto; case BPF_FUNC_sock_map_update: return &bpf_sock_map_update_proto; default: @@ -4546,6 +4575,11 @@ static u32 sock_ops_convert_ctx_access(enum bpf_access_type type, case offsetof(struct bpf_sock_ops, srtt_us): SOCK_OPS_GET_FIELD(srtt_us, srtt_us, struct tcp_sock); break; + + case offsetof(struct bpf_sock_ops, bpf_sock_ops_cb_flags): + SOCK_OPS_GET_FIELD(bpf_sock_ops_cb_flags, bpf_sock_ops_cb_flags, + struct tcp_sock); + break; } return insn - insn_buf; } From f89013f66d0f1a0dad44c513318efb706399a36b Mon Sep 17 00:00:00 2001 From: Lawrence Brakmo Date: Thu, 25 Jan 2018 16:14:11 -0800 Subject: [PATCH 07/12] bpf: Add sock_ops RTO callback Adds an optional call to sock_ops BPF program based on whether the BPF_SOCK_OPS_RTO_CB_FLAG is set in bpf_sock_ops_flags. The BPF program is passed 2 arguments: icsk_retransmits and whether the RTO has expired. Signed-off-by: Lawrence Brakmo Signed-off-by: Alexei Starovoitov --- include/uapi/linux/bpf.h | 8 +++++++- net/ipv4/tcp_timer.c | 7 +++++++ 2 files changed, 14 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index aa128407c44db..c8cecf9cf5bd8 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -982,7 +982,8 @@ struct bpf_sock_ops { }; /* Definitions for bpf_sock_ops_cb_flags */ -#define BPF_SOCK_OPS_ALL_CB_FLAGS 0 /* Mask of all currently +#define BPF_SOCK_OPS_RTO_CB_FLAG (1<<0) +#define BPF_SOCK_OPS_ALL_CB_FLAGS 0x1 /* Mask of all currently * supported cb flags */ @@ -1019,6 +1020,11 @@ enum { * a congestion threshold. RTTs above * this indicate congestion */ + BPF_SOCK_OPS_RTO_CB, /* Called when an RTO has triggered. + * Arg1: value of icsk_retransmits + * Arg2: value of icsk_rto + * Arg3: whether RTO has expired + */ }; #define TCP_BPF_IW 1001 /* Set TCP initial congestion window */ diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index 6db3124cdbda9..257abdde23b0d 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -213,11 +213,18 @@ static int tcp_write_timeout(struct sock *sk) icsk->icsk_user_timeout); } tcp_fastopen_active_detect_blackhole(sk, expired); + + if (BPF_SOCK_OPS_TEST_FLAG(tp, BPF_SOCK_OPS_RTO_CB_FLAG)) + tcp_call_bpf_3arg(sk, BPF_SOCK_OPS_RTO_CB, + icsk->icsk_retransmits, + icsk->icsk_rto, (int)expired); + if (expired) { /* Has it gone just too far? */ tcp_write_err(sk); return 1; } + return 0; } From 44f0e43037d3a17b043843ba67610ac7c7e37db6 Mon Sep 17 00:00:00 2001 From: Lawrence Brakmo Date: Thu, 25 Jan 2018 16:14:12 -0800 Subject: [PATCH 08/12] bpf: Add support for reading sk_state and more Add support for reading many more tcp_sock fields state, same as sk->sk_state rtt_min same as sk->rtt_min.s[0].v (current rtt_min) snd_ssthresh rcv_nxt snd_nxt snd_una mss_cache ecn_flags rate_delivered rate_interval_us packets_out retrans_out total_retrans segs_in data_segs_in segs_out data_segs_out lost_out sacked_out sk_txhash bytes_received (__u64) bytes_acked (__u64) Signed-off-by: Lawrence Brakmo Signed-off-by: Alexei Starovoitov --- include/uapi/linux/bpf.h | 22 ++++++ net/core/filter.c | 143 ++++++++++++++++++++++++++++++++++++--- 2 files changed, 154 insertions(+), 11 deletions(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index c8cecf9cf5bd8..46520eae37fa9 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -979,6 +979,28 @@ struct bpf_sock_ops { __u32 snd_cwnd; __u32 srtt_us; /* Averaged RTT << 3 in usecs */ __u32 bpf_sock_ops_cb_flags; /* flags defined in uapi/linux/tcp.h */ + __u32 state; + __u32 rtt_min; + __u32 snd_ssthresh; + __u32 rcv_nxt; + __u32 snd_nxt; + __u32 snd_una; + __u32 mss_cache; + __u32 ecn_flags; + __u32 rate_delivered; + __u32 rate_interval_us; + __u32 packets_out; + __u32 retrans_out; + __u32 total_retrans; + __u32 segs_in; + __u32 data_segs_in; + __u32 segs_out; + __u32 data_segs_out; + __u32 lost_out; + __u32 sacked_out; + __u32 sk_txhash; + __u64 bytes_received; + __u64 bytes_acked; }; /* Definitions for bpf_sock_ops_cb_flags */ diff --git a/net/core/filter.c b/net/core/filter.c index 6936d19ac7365..a858ebc4ece43 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -3855,33 +3855,43 @@ void bpf_warn_invalid_xdp_action(u32 act) } EXPORT_SYMBOL_GPL(bpf_warn_invalid_xdp_action); -static bool __is_valid_sock_ops_access(int off, int size) +static bool sock_ops_is_valid_access(int off, int size, + enum bpf_access_type type, + struct bpf_insn_access_aux *info) { + const int size_default = sizeof(__u32); + if (off < 0 || off >= sizeof(struct bpf_sock_ops)) return false; + /* The verifier guarantees that size > 0. */ if (off % size != 0) return false; - if (size != sizeof(__u32)) - return false; - - return true; -} -static bool sock_ops_is_valid_access(int off, int size, - enum bpf_access_type type, - struct bpf_insn_access_aux *info) -{ if (type == BPF_WRITE) { switch (off) { case offsetof(struct bpf_sock_ops, reply): + if (size != size_default) + return false; break; default: return false; } + } else { + switch (off) { + case bpf_ctx_range_till(struct bpf_sock_ops, bytes_received, + bytes_acked): + if (size != sizeof(__u64)) + return false; + break; + default: + if (size != size_default) + return false; + break; + } } - return __is_valid_sock_ops_access(off, size); + return true; } static int sk_skb_prologue(struct bpf_insn *insn_buf, bool direct_write, @@ -4498,6 +4508,32 @@ static u32 sock_ops_convert_ctx_access(enum bpf_access_type type, is_fullsock)); break; + case offsetof(struct bpf_sock_ops, state): + BUILD_BUG_ON(FIELD_SIZEOF(struct sock_common, skc_state) != 1); + + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF( + struct bpf_sock_ops_kern, sk), + si->dst_reg, si->src_reg, + offsetof(struct bpf_sock_ops_kern, sk)); + *insn++ = BPF_LDX_MEM(BPF_B, si->dst_reg, si->dst_reg, + offsetof(struct sock_common, skc_state)); + break; + + case offsetof(struct bpf_sock_ops, rtt_min): + BUILD_BUG_ON(FIELD_SIZEOF(struct tcp_sock, rtt_min) != + sizeof(struct minmax)); + BUILD_BUG_ON(sizeof(struct minmax) < + sizeof(struct minmax_sample)); + + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF( + struct bpf_sock_ops_kern, sk), + si->dst_reg, si->src_reg, + offsetof(struct bpf_sock_ops_kern, sk)); + *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->dst_reg, + offsetof(struct tcp_sock, rtt_min) + + FIELD_SIZEOF(struct minmax_sample, t)); + break; + /* Helper macro for adding read access to tcp_sock or sock fields. */ #define SOCK_OPS_GET_FIELD(BPF_FIELD, OBJ_FIELD, OBJ) \ do { \ @@ -4580,6 +4616,91 @@ static u32 sock_ops_convert_ctx_access(enum bpf_access_type type, SOCK_OPS_GET_FIELD(bpf_sock_ops_cb_flags, bpf_sock_ops_cb_flags, struct tcp_sock); break; + + case offsetof(struct bpf_sock_ops, snd_ssthresh): + SOCK_OPS_GET_FIELD(snd_ssthresh, snd_ssthresh, struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, rcv_nxt): + SOCK_OPS_GET_FIELD(rcv_nxt, rcv_nxt, struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, snd_nxt): + SOCK_OPS_GET_FIELD(snd_nxt, snd_nxt, struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, snd_una): + SOCK_OPS_GET_FIELD(snd_una, snd_una, struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, mss_cache): + SOCK_OPS_GET_FIELD(mss_cache, mss_cache, struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, ecn_flags): + SOCK_OPS_GET_FIELD(ecn_flags, ecn_flags, struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, rate_delivered): + SOCK_OPS_GET_FIELD(rate_delivered, rate_delivered, + struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, rate_interval_us): + SOCK_OPS_GET_FIELD(rate_interval_us, rate_interval_us, + struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, packets_out): + SOCK_OPS_GET_FIELD(packets_out, packets_out, struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, retrans_out): + SOCK_OPS_GET_FIELD(retrans_out, retrans_out, struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, total_retrans): + SOCK_OPS_GET_FIELD(total_retrans, total_retrans, + struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, segs_in): + SOCK_OPS_GET_FIELD(segs_in, segs_in, struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, data_segs_in): + SOCK_OPS_GET_FIELD(data_segs_in, data_segs_in, struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, segs_out): + SOCK_OPS_GET_FIELD(segs_out, segs_out, struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, data_segs_out): + SOCK_OPS_GET_FIELD(data_segs_out, data_segs_out, + struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, lost_out): + SOCK_OPS_GET_FIELD(lost_out, lost_out, struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, sacked_out): + SOCK_OPS_GET_FIELD(sacked_out, sacked_out, struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, sk_txhash): + SOCK_OPS_GET_FIELD(sk_txhash, sk_txhash, struct sock); + break; + + case offsetof(struct bpf_sock_ops, bytes_received): + SOCK_OPS_GET_FIELD(bytes_received, bytes_received, + struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, bytes_acked): + SOCK_OPS_GET_FIELD(bytes_acked, bytes_acked, struct tcp_sock); + break; } return insn - insn_buf; } From 6f9bd3d731aac0d2ac21dd78a642af5df38fb5c5 Mon Sep 17 00:00:00 2001 From: Lawrence Brakmo Date: Thu, 25 Jan 2018 16:14:13 -0800 Subject: [PATCH 09/12] bpf: Add sock_ops R/W access to tclass Adds direct write access to sk_txhash and access to tclass for ipv6 flows through getsockopt and setsockopt. Sample usage for tclass: bpf_getsockopt(skops, SOL_IPV6, IPV6_TCLASS, &v, sizeof(v)) where skops is a pointer to the ctx (struct bpf_sock_ops). Signed-off-by: Lawrence Brakmo Signed-off-by: Alexei Starovoitov --- net/core/filter.c | 47 +++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 45 insertions(+), 2 deletions(-) diff --git a/net/core/filter.c b/net/core/filter.c index a858ebc4ece43..fe2c7937351f5 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -3232,6 +3232,29 @@ BPF_CALL_5(bpf_setsockopt, struct bpf_sock_ops_kern *, bpf_sock, ret = -EINVAL; } #ifdef CONFIG_INET +#if IS_ENABLED(CONFIG_IPV6) + } else if (level == SOL_IPV6) { + if (optlen != sizeof(int) || sk->sk_family != AF_INET6) + return -EINVAL; + + val = *((int *)optval); + /* Only some options are supported */ + switch (optname) { + case IPV6_TCLASS: + if (val < -1 || val > 0xff) { + ret = -EINVAL; + } else { + struct ipv6_pinfo *np = inet6_sk(sk); + + if (val == -1) + val = 0; + np->tclass = val; + } + break; + default: + ret = -EINVAL; + } +#endif } else if (level == SOL_TCP && sk->sk_prot->setsockopt == tcp_setsockopt) { if (optname == TCP_CONGESTION) { @@ -3241,7 +3264,8 @@ BPF_CALL_5(bpf_setsockopt, struct bpf_sock_ops_kern *, bpf_sock, strncpy(name, optval, min_t(long, optlen, TCP_CA_NAME_MAX-1)); name[TCP_CA_NAME_MAX-1] = 0; - ret = tcp_set_congestion_control(sk, name, false, reinit); + ret = tcp_set_congestion_control(sk, name, false, + reinit); } else { struct tcp_sock *tp = tcp_sk(sk); @@ -3307,6 +3331,22 @@ BPF_CALL_5(bpf_getsockopt, struct bpf_sock_ops_kern *, bpf_sock, } else { goto err_clear; } +#if IS_ENABLED(CONFIG_IPV6) + } else if (level == SOL_IPV6) { + struct ipv6_pinfo *np = inet6_sk(sk); + + if (optlen != sizeof(int) || sk->sk_family != AF_INET6) + goto err_clear; + + /* Only some options are supported */ + switch (optname) { + case IPV6_TCLASS: + *((int *)optval) = (int)np->tclass; + break; + default: + goto err_clear; + } +#endif } else { goto err_clear; } @@ -3871,6 +3911,7 @@ static bool sock_ops_is_valid_access(int off, int size, if (type == BPF_WRITE) { switch (off) { case offsetof(struct bpf_sock_ops, reply): + case offsetof(struct bpf_sock_ops, sk_txhash): if (size != size_default) return false; break; @@ -4690,7 +4731,8 @@ static u32 sock_ops_convert_ctx_access(enum bpf_access_type type, break; case offsetof(struct bpf_sock_ops, sk_txhash): - SOCK_OPS_GET_FIELD(sk_txhash, sk_txhash, struct sock); + SOCK_OPS_GET_OR_SET_FIELD(sk_txhash, sk_txhash, + struct sock, type); break; case offsetof(struct bpf_sock_ops, bytes_received): @@ -4701,6 +4743,7 @@ static u32 sock_ops_convert_ctx_access(enum bpf_access_type type, case offsetof(struct bpf_sock_ops, bytes_acked): SOCK_OPS_GET_FIELD(bytes_acked, bytes_acked, struct tcp_sock); break; + } return insn - insn_buf; } From a31ad29e6a30cb0b9084a9425b819cdcd97273ce Mon Sep 17 00:00:00 2001 From: Lawrence Brakmo Date: Thu, 25 Jan 2018 16:14:14 -0800 Subject: [PATCH 10/12] bpf: Add BPF_SOCK_OPS_RETRANS_CB Adds support for calling sock_ops BPF program when there is a retransmission. Three arguments are used; one for the sequence number, another for the number of segments retransmitted, and the last one for the return value of tcp_transmit_skb (0 => success). Does not include syn-ack retransmissions. New op: BPF_SOCK_OPS_RETRANS_CB. Signed-off-by: Lawrence Brakmo Signed-off-by: Alexei Starovoitov --- include/uapi/linux/bpf.h | 9 ++++++++- net/ipv4/tcp_output.c | 4 ++++ 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 46520eae37fa9..31c93a0bdbc29 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -1005,7 +1005,8 @@ struct bpf_sock_ops { /* Definitions for bpf_sock_ops_cb_flags */ #define BPF_SOCK_OPS_RTO_CB_FLAG (1<<0) -#define BPF_SOCK_OPS_ALL_CB_FLAGS 0x1 /* Mask of all currently +#define BPF_SOCK_OPS_RETRANS_CB_FLAG (1<<1) +#define BPF_SOCK_OPS_ALL_CB_FLAGS 0x3 /* Mask of all currently * supported cb flags */ @@ -1047,6 +1048,12 @@ enum { * Arg2: value of icsk_rto * Arg3: whether RTO has expired */ + BPF_SOCK_OPS_RETRANS_CB, /* Called when skb is retransmitted. + * Arg1: sequence number of 1st byte + * Arg2: # segments + * Arg3: return value of + * tcp_transmit_skb (0 => success) + */ }; #define TCP_BPF_IW 1001 /* Set TCP initial congestion window */ diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index d12f7f71c1c40..e9f985e42405a 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2905,6 +2905,10 @@ int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs) err = tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC); } + if (BPF_SOCK_OPS_TEST_FLAG(tp, BPF_SOCK_OPS_RETRANS_CB_FLAG)) + tcp_call_bpf_3arg(sk, BPF_SOCK_OPS_RETRANS_CB, + TCP_SKB_CB(skb)->seq, segs, err); + if (likely(!err)) { TCP_SKB_CB(skb)->sacked |= TCPCB_EVER_RETRANS; trace_tcp_retransmit_skb(sk, skb); From d44874910a26f3a8f81edf873a2473363f07f660 Mon Sep 17 00:00:00 2001 From: Lawrence Brakmo Date: Thu, 25 Jan 2018 16:14:15 -0800 Subject: [PATCH 11/12] bpf: Add BPF_SOCK_OPS_STATE_CB Adds support for calling sock_ops BPF program when there is a TCP state change. Two arguments are used; one for the old state and another for the new state. There is a new enum in include/uapi/linux/bpf.h that exports the TCP states that prepends BPF_ to the current TCP state names. If it is ever necessary to change the internal TCP state values (other than adding more to the end), then it will become necessary to convert from the internal TCP state value to the BPF value before calling the BPF sock_ops function. There are a set of compile checks added in tcp.c to detect if the internal and BPF values differ so we can make the necessary fixes. New op: BPF_SOCK_OPS_STATE_CB. Signed-off-by: Lawrence Brakmo Signed-off-by: Alexei Starovoitov --- include/uapi/linux/bpf.h | 29 ++++++++++++++++++++++++++++- net/ipv4/tcp.c | 24 ++++++++++++++++++++++++ 2 files changed, 52 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 31c93a0bdbc29..db6bdc3751268 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -1006,7 +1006,8 @@ struct bpf_sock_ops { /* Definitions for bpf_sock_ops_cb_flags */ #define BPF_SOCK_OPS_RTO_CB_FLAG (1<<0) #define BPF_SOCK_OPS_RETRANS_CB_FLAG (1<<1) -#define BPF_SOCK_OPS_ALL_CB_FLAGS 0x3 /* Mask of all currently +#define BPF_SOCK_OPS_STATE_CB_FLAG (1<<2) +#define BPF_SOCK_OPS_ALL_CB_FLAGS 0x7 /* Mask of all currently * supported cb flags */ @@ -1054,6 +1055,32 @@ enum { * Arg3: return value of * tcp_transmit_skb (0 => success) */ + BPF_SOCK_OPS_STATE_CB, /* Called when TCP changes state. + * Arg1: old_state + * Arg2: new_state + */ +}; + +/* List of TCP states. There is a build check in net/ipv4/tcp.c to detect + * changes between the TCP and BPF versions. Ideally this should never happen. + * If it does, we need to add code to convert them before calling + * the BPF sock_ops function. + */ +enum { + BPF_TCP_ESTABLISHED = 1, + BPF_TCP_SYN_SENT, + BPF_TCP_SYN_RECV, + BPF_TCP_FIN_WAIT1, + BPF_TCP_FIN_WAIT2, + BPF_TCP_TIME_WAIT, + BPF_TCP_CLOSE, + BPF_TCP_CLOSE_WAIT, + BPF_TCP_LAST_ACK, + BPF_TCP_LISTEN, + BPF_TCP_CLOSING, /* Now a valid state */ + BPF_TCP_NEW_SYN_RECV, + + BPF_TCP_MAX_STATES /* Leave at the end! */ }; #define TCP_BPF_IW 1001 /* Set TCP initial congestion window */ diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 88b62441e7e96..f013ddc191e0c 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2042,6 +2042,30 @@ void tcp_set_state(struct sock *sk, int state) { int oldstate = sk->sk_state; + /* We defined a new enum for TCP states that are exported in BPF + * so as not force the internal TCP states to be frozen. The + * following checks will detect if an internal state value ever + * differs from the BPF value. If this ever happens, then we will + * need to remap the internal value to the BPF value before calling + * tcp_call_bpf_2arg. + */ + BUILD_BUG_ON((int)BPF_TCP_ESTABLISHED != (int)TCP_ESTABLISHED); + BUILD_BUG_ON((int)BPF_TCP_SYN_SENT != (int)TCP_SYN_SENT); + BUILD_BUG_ON((int)BPF_TCP_SYN_RECV != (int)TCP_SYN_RECV); + BUILD_BUG_ON((int)BPF_TCP_FIN_WAIT1 != (int)TCP_FIN_WAIT1); + BUILD_BUG_ON((int)BPF_TCP_FIN_WAIT2 != (int)TCP_FIN_WAIT2); + BUILD_BUG_ON((int)BPF_TCP_TIME_WAIT != (int)TCP_TIME_WAIT); + BUILD_BUG_ON((int)BPF_TCP_CLOSE != (int)TCP_CLOSE); + BUILD_BUG_ON((int)BPF_TCP_CLOSE_WAIT != (int)TCP_CLOSE_WAIT); + BUILD_BUG_ON((int)BPF_TCP_LAST_ACK != (int)TCP_LAST_ACK); + BUILD_BUG_ON((int)BPF_TCP_LISTEN != (int)TCP_LISTEN); + BUILD_BUG_ON((int)BPF_TCP_CLOSING != (int)TCP_CLOSING); + BUILD_BUG_ON((int)BPF_TCP_NEW_SYN_RECV != (int)TCP_NEW_SYN_RECV); + BUILD_BUG_ON((int)BPF_TCP_MAX_STATES != (int)TCP_MAX_STATES); + + if (BPF_SOCK_OPS_TEST_FLAG(tcp_sk(sk), BPF_SOCK_OPS_STATE_CB_FLAG)) + tcp_call_bpf_2arg(sk, BPF_SOCK_OPS_STATE_CB, oldstate, state); + switch (state) { case TCP_ESTABLISHED: if (oldstate != TCP_ESTABLISHED) From d6d4f60c3a0933852dcc40a2142d93027ea1da76 Mon Sep 17 00:00:00 2001 From: Lawrence Brakmo Date: Thu, 25 Jan 2018 16:14:16 -0800 Subject: [PATCH 12/12] bpf: add selftest for tcpbpf Added a selftest for tcpbpf (sock_ops) that checks that the appropriate callbacks occured and that it can access tcp_sock fields and that their values are correct. Run with command: ./test_tcpbpf_user Adding the flag "-d" will show why it did not pass. Signed-off-by: Lawrence Brakmo Acked-by: Alexei Starovoitov Signed-off-by: Alexei Starovoitov --- tools/include/uapi/linux/bpf.h | 86 +++++++++++- tools/testing/selftests/bpf/Makefile | 4 +- tools/testing/selftests/bpf/bpf_helpers.h | 2 + tools/testing/selftests/bpf/tcp_client.py | 51 +++++++ tools/testing/selftests/bpf/tcp_server.py | 83 ++++++++++++ tools/testing/selftests/bpf/test_tcpbpf.h | 16 +++ .../testing/selftests/bpf/test_tcpbpf_kern.c | 118 ++++++++++++++++ .../testing/selftests/bpf/test_tcpbpf_user.c | 126 ++++++++++++++++++ 8 files changed, 480 insertions(+), 6 deletions(-) create mode 100755 tools/testing/selftests/bpf/tcp_client.py create mode 100755 tools/testing/selftests/bpf/tcp_server.py create mode 100644 tools/testing/selftests/bpf/test_tcpbpf.h create mode 100644 tools/testing/selftests/bpf/test_tcpbpf_kern.c create mode 100644 tools/testing/selftests/bpf/test_tcpbpf_user.c diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index af1f49ad8b88d..db6bdc3751268 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -17,7 +17,7 @@ #define BPF_ALU64 0x07 /* alu mode in double word width */ /* ld/ldx fields */ -#define BPF_DW 0x18 /* double word */ +#define BPF_DW 0x18 /* double word (64-bit) */ #define BPF_XADD 0xc0 /* exclusive add */ /* alu/jmp fields */ @@ -642,6 +642,14 @@ union bpf_attr { * @optlen: length of optval in bytes * Return: 0 or negative error * + * int bpf_sock_ops_cb_flags_set(bpf_sock_ops, flags) + * Set callback flags for sock_ops + * @bpf_sock_ops: pointer to bpf_sock_ops_kern struct + * @flags: flags value + * Return: 0 for no error + * -EINVAL if there is no full tcp socket + * bits in flags that are not supported by current kernel + * * int bpf_skb_adjust_room(skb, len_diff, mode, flags) * Grow or shrink room in sk_buff. * @skb: pointer to skb @@ -748,7 +756,8 @@ union bpf_attr { FN(perf_event_read_value), \ FN(perf_prog_read_value), \ FN(getsockopt), \ - FN(override_return), + FN(override_return), \ + FN(sock_ops_cb_flags_set), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call @@ -952,8 +961,9 @@ struct bpf_map_info { struct bpf_sock_ops { __u32 op; union { - __u32 reply; - __u32 replylong[4]; + __u32 args[4]; /* Optionally passed to bpf program */ + __u32 reply; /* Returned by bpf program */ + __u32 replylong[4]; /* Optionally returned by bpf prog */ }; __u32 family; __u32 remote_ip4; /* Stored in network byte order */ @@ -968,8 +978,39 @@ struct bpf_sock_ops { */ __u32 snd_cwnd; __u32 srtt_us; /* Averaged RTT << 3 in usecs */ + __u32 bpf_sock_ops_cb_flags; /* flags defined in uapi/linux/tcp.h */ + __u32 state; + __u32 rtt_min; + __u32 snd_ssthresh; + __u32 rcv_nxt; + __u32 snd_nxt; + __u32 snd_una; + __u32 mss_cache; + __u32 ecn_flags; + __u32 rate_delivered; + __u32 rate_interval_us; + __u32 packets_out; + __u32 retrans_out; + __u32 total_retrans; + __u32 segs_in; + __u32 data_segs_in; + __u32 segs_out; + __u32 data_segs_out; + __u32 lost_out; + __u32 sacked_out; + __u32 sk_txhash; + __u64 bytes_received; + __u64 bytes_acked; }; +/* Definitions for bpf_sock_ops_cb_flags */ +#define BPF_SOCK_OPS_RTO_CB_FLAG (1<<0) +#define BPF_SOCK_OPS_RETRANS_CB_FLAG (1<<1) +#define BPF_SOCK_OPS_STATE_CB_FLAG (1<<2) +#define BPF_SOCK_OPS_ALL_CB_FLAGS 0x7 /* Mask of all currently + * supported cb flags + */ + /* List of known BPF sock_ops operators. * New entries can only be added at the end */ @@ -1003,6 +1044,43 @@ enum { * a congestion threshold. RTTs above * this indicate congestion */ + BPF_SOCK_OPS_RTO_CB, /* Called when an RTO has triggered. + * Arg1: value of icsk_retransmits + * Arg2: value of icsk_rto + * Arg3: whether RTO has expired + */ + BPF_SOCK_OPS_RETRANS_CB, /* Called when skb is retransmitted. + * Arg1: sequence number of 1st byte + * Arg2: # segments + * Arg3: return value of + * tcp_transmit_skb (0 => success) + */ + BPF_SOCK_OPS_STATE_CB, /* Called when TCP changes state. + * Arg1: old_state + * Arg2: new_state + */ +}; + +/* List of TCP states. There is a build check in net/ipv4/tcp.c to detect + * changes between the TCP and BPF versions. Ideally this should never happen. + * If it does, we need to add code to convert them before calling + * the BPF sock_ops function. + */ +enum { + BPF_TCP_ESTABLISHED = 1, + BPF_TCP_SYN_SENT, + BPF_TCP_SYN_RECV, + BPF_TCP_FIN_WAIT1, + BPF_TCP_FIN_WAIT2, + BPF_TCP_TIME_WAIT, + BPF_TCP_CLOSE, + BPF_TCP_CLOSE_WAIT, + BPF_TCP_LAST_ACK, + BPF_TCP_LISTEN, + BPF_TCP_CLOSING, /* Now a valid state */ + BPF_TCP_NEW_SYN_RECV, + + BPF_TCP_MAX_STATES /* Leave at the end! */ }; #define TCP_BPF_IW 1001 /* Set TCP initial congestion window */ diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 3a44b655d852d..98688352208b5 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -14,13 +14,13 @@ CFLAGS += -Wall -O2 -I$(APIDIR) -I$(LIBDIR) -I$(GENDIR) $(GENFLAGS) -I../../../i LDLIBS += -lcap -lelf -lrt TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test_progs \ - test_align test_verifier_log test_dev_cgroup + test_align test_verifier_log test_dev_cgroup test_tcpbpf_user TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o test_obj_id.o \ test_pkt_md_access.o test_xdp_redirect.o test_xdp_meta.o sockmap_parse_prog.o \ sockmap_verdict_prog.o dev_cgroup.o sample_ret0.o test_tracepoint.o \ test_l4lb_noinline.o test_xdp_noinline.o test_stacktrace_map.o \ - sample_map_ret0.o + sample_map_ret0.o test_tcpbpf_kern.o TEST_PROGS := test_kmod.sh test_xdp_redirect.sh test_xdp_meta.sh \ test_offload.py diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h index 33cb00e46c49f..dde2c11d77710 100644 --- a/tools/testing/selftests/bpf/bpf_helpers.h +++ b/tools/testing/selftests/bpf/bpf_helpers.h @@ -71,6 +71,8 @@ static int (*bpf_setsockopt)(void *ctx, int level, int optname, void *optval, static int (*bpf_getsockopt)(void *ctx, int level, int optname, void *optval, int optlen) = (void *) BPF_FUNC_getsockopt; +static int (*bpf_sock_ops_cb_flags_set)(void *ctx, int flags) = + (void *) BPF_FUNC_sock_ops_cb_flags_set; static int (*bpf_sk_redirect_map)(void *ctx, void *map, int key, int flags) = (void *) BPF_FUNC_sk_redirect_map; static int (*bpf_sock_map_update)(void *map, void *key, void *value, diff --git a/tools/testing/selftests/bpf/tcp_client.py b/tools/testing/selftests/bpf/tcp_client.py new file mode 100755 index 0000000000000..481dccdf140ce --- /dev/null +++ b/tools/testing/selftests/bpf/tcp_client.py @@ -0,0 +1,51 @@ +#!/usr/bin/env python2 +# +# SPDX-License-Identifier: GPL-2.0 +# + +import sys, os, os.path, getopt +import socket, time +import subprocess +import select + +def read(sock, n): + buf = '' + while len(buf) < n: + rem = n - len(buf) + try: s = sock.recv(rem) + except (socket.error), e: return '' + buf += s + return buf + +def send(sock, s): + total = len(s) + count = 0 + while count < total: + try: n = sock.send(s) + except (socket.error), e: n = 0 + if n == 0: + return count; + count += n + return count + + +serverPort = int(sys.argv[1]) +HostName = socket.gethostname() + +# create active socket +sock = socket.socket(socket.AF_INET6, socket.SOCK_STREAM) +try: + sock.connect((HostName, serverPort)) +except socket.error as e: + sys.exit(1) + +buf = '' +n = 0 +while n < 1000: + buf += '+' + n += 1 + +sock.settimeout(1); +n = send(sock, buf) +n = read(sock, 500) +sys.exit(0) diff --git a/tools/testing/selftests/bpf/tcp_server.py b/tools/testing/selftests/bpf/tcp_server.py new file mode 100755 index 0000000000000..bc454d7d0be21 --- /dev/null +++ b/tools/testing/selftests/bpf/tcp_server.py @@ -0,0 +1,83 @@ +#!/usr/bin/env python2 +# +# SPDX-License-Identifier: GPL-2.0 +# + +import sys, os, os.path, getopt +import socket, time +import subprocess +import select + +def read(sock, n): + buf = '' + while len(buf) < n: + rem = n - len(buf) + try: s = sock.recv(rem) + except (socket.error), e: return '' + buf += s + return buf + +def send(sock, s): + total = len(s) + count = 0 + while count < total: + try: n = sock.send(s) + except (socket.error), e: n = 0 + if n == 0: + return count; + count += n + return count + + +SERVER_PORT = 12877 +MAX_PORTS = 2 + +serverPort = SERVER_PORT +serverSocket = None + +HostName = socket.gethostname() + +# create passive socket +serverSocket = socket.socket(socket.AF_INET6, socket.SOCK_STREAM) +host = socket.gethostname() + +try: serverSocket.bind((host, 0)) +except socket.error as msg: + print 'bind fails: ', msg + +sn = serverSocket.getsockname() +serverPort = sn[1] + +cmdStr = ("./tcp_client.py %d &") % (serverPort) +os.system(cmdStr) + +buf = '' +n = 0 +while n < 500: + buf += '.' + n += 1 + +serverSocket.listen(MAX_PORTS) +readList = [serverSocket] + +while True: + readyRead, readyWrite, inError = \ + select.select(readList, [], [], 2) + + if len(readyRead) > 0: + waitCount = 0 + for sock in readyRead: + if sock == serverSocket: + (clientSocket, address) = serverSocket.accept() + address = str(address[0]) + readList.append(clientSocket) + else: + sock.settimeout(1); + s = read(sock, 1000) + n = send(sock, buf) + sock.close() + serverSocket.close() + sys.exit(0) + else: + print 'Select timeout!' + sys.exit(1) diff --git a/tools/testing/selftests/bpf/test_tcpbpf.h b/tools/testing/selftests/bpf/test_tcpbpf.h new file mode 100644 index 0000000000000..2fe43289943c7 --- /dev/null +++ b/tools/testing/selftests/bpf/test_tcpbpf.h @@ -0,0 +1,16 @@ +// SPDX-License-Identifier: GPL-2.0 + +#ifndef _TEST_TCPBPF_H +#define _TEST_TCPBPF_H + +struct tcpbpf_globals { + __u32 event_map; + __u32 total_retrans; + __u32 data_segs_in; + __u32 data_segs_out; + __u32 bad_cb_test_rv; + __u32 good_cb_test_rv; + __u64 bytes_received; + __u64 bytes_acked; +}; +#endif diff --git a/tools/testing/selftests/bpf/test_tcpbpf_kern.c b/tools/testing/selftests/bpf/test_tcpbpf_kern.c new file mode 100644 index 0000000000000..66bf71541903f --- /dev/null +++ b/tools/testing/selftests/bpf/test_tcpbpf_kern.c @@ -0,0 +1,118 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "bpf_helpers.h" +#include "bpf_endian.h" +#include "test_tcpbpf.h" + +struct bpf_map_def SEC("maps") global_map = { + .type = BPF_MAP_TYPE_ARRAY, + .key_size = sizeof(__u32), + .value_size = sizeof(struct tcpbpf_globals), + .max_entries = 2, +}; + +static inline void update_event_map(int event) +{ + __u32 key = 0; + struct tcpbpf_globals g, *gp; + + gp = bpf_map_lookup_elem(&global_map, &key); + if (gp == NULL) { + struct tcpbpf_globals g = {0}; + + g.event_map |= (1 << event); + bpf_map_update_elem(&global_map, &key, &g, + BPF_ANY); + } else { + g = *gp; + g.event_map |= (1 << event); + bpf_map_update_elem(&global_map, &key, &g, + BPF_ANY); + } +} + +int _version SEC("version") = 1; + +SEC("sockops") +int bpf_testcb(struct bpf_sock_ops *skops) +{ + int rv = -1; + int bad_call_rv = 0; + int good_call_rv = 0; + int op; + int v = 0; + + op = (int) skops->op; + + update_event_map(op); + + switch (op) { + case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB: + /* Test failure to set largest cb flag (assumes not defined) */ + bad_call_rv = bpf_sock_ops_cb_flags_set(skops, 0x80); + /* Set callback */ + good_call_rv = bpf_sock_ops_cb_flags_set(skops, + BPF_SOCK_OPS_STATE_CB_FLAG); + /* Update results */ + { + __u32 key = 0; + struct tcpbpf_globals g, *gp; + + gp = bpf_map_lookup_elem(&global_map, &key); + if (!gp) + break; + g = *gp; + g.bad_cb_test_rv = bad_call_rv; + g.good_cb_test_rv = good_call_rv; + bpf_map_update_elem(&global_map, &key, &g, + BPF_ANY); + } + break; + case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB: + /* Set callback */ +// good_call_rv = bpf_sock_ops_cb_flags_set(skops, +// BPF_SOCK_OPS_STATE_CB_FLAG); + skops->sk_txhash = 0x12345f; + v = 0xff; + rv = bpf_setsockopt(skops, SOL_IPV6, IPV6_TCLASS, &v, + sizeof(v)); + break; + case BPF_SOCK_OPS_RTO_CB: + break; + case BPF_SOCK_OPS_RETRANS_CB: + break; + case BPF_SOCK_OPS_STATE_CB: + if (skops->args[1] == BPF_TCP_CLOSE) { + __u32 key = 0; + struct tcpbpf_globals g, *gp; + + gp = bpf_map_lookup_elem(&global_map, &key); + if (!gp) + break; + g = *gp; + g.total_retrans = skops->total_retrans; + g.data_segs_in = skops->data_segs_in; + g.data_segs_out = skops->data_segs_out; + g.bytes_received = skops->bytes_received; + g.bytes_acked = skops->bytes_acked; + bpf_map_update_elem(&global_map, &key, &g, + BPF_ANY); + } + break; + default: + rv = -1; + } + skops->reply = rv; + return 1; +} +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/test_tcpbpf_user.c b/tools/testing/selftests/bpf/test_tcpbpf_user.c new file mode 100644 index 0000000000000..95a370f3d3784 --- /dev/null +++ b/tools/testing/selftests/bpf/test_tcpbpf_user.c @@ -0,0 +1,126 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "bpf_util.h" +#include +#include "test_tcpbpf.h" + +static int bpf_find_map(const char *test, struct bpf_object *obj, + const char *name) +{ + struct bpf_map *map; + + map = bpf_object__find_map_by_name(obj, name); + if (!map) { + printf("%s:FAIL:map '%s' not found\n", test, name); + return -1; + } + return bpf_map__fd(map); +} + +#define SYSTEM(CMD) \ + do { \ + if (system(CMD)) { \ + printf("system(%s) FAILS!\n", CMD); \ + } \ + } while (0) + +int main(int argc, char **argv) +{ + const char *file = "test_tcpbpf_kern.o"; + struct tcpbpf_globals g = {0}; + int cg_fd, prog_fd, map_fd; + bool debug_flag = false; + int error = EXIT_FAILURE; + struct bpf_object *obj; + char cmd[100], *dir; + struct stat buffer; + __u32 key = 0; + int pid; + int rv; + + if (argc > 1 && strcmp(argv[1], "-d") == 0) + debug_flag = true; + + dir = "/tmp/cgroupv2/foo"; + + if (stat(dir, &buffer) != 0) { + SYSTEM("mkdir -p /tmp/cgroupv2"); + SYSTEM("mount -t cgroup2 none /tmp/cgroupv2"); + SYSTEM("mkdir -p /tmp/cgroupv2/foo"); + } + pid = (int) getpid(); + sprintf(cmd, "echo %d >> /tmp/cgroupv2/foo/cgroup.procs", pid); + SYSTEM(cmd); + + cg_fd = open(dir, O_DIRECTORY, O_RDONLY); + if (bpf_prog_load(file, BPF_PROG_TYPE_SOCK_OPS, &obj, &prog_fd)) { + printf("FAILED: load_bpf_file failed for: %s\n", file); + goto err; + } + + rv = bpf_prog_attach(prog_fd, cg_fd, BPF_CGROUP_SOCK_OPS, 0); + if (rv) { + printf("FAILED: bpf_prog_attach: %d (%s)\n", + error, strerror(errno)); + goto err; + } + + SYSTEM("./tcp_server.py"); + + map_fd = bpf_find_map(__func__, obj, "global_map"); + if (map_fd < 0) + goto err; + + rv = bpf_map_lookup_elem(map_fd, &key, &g); + if (rv != 0) { + printf("FAILED: bpf_map_lookup_elem returns %d\n", rv); + goto err; + } + + if (g.bytes_received != 501 || g.bytes_acked != 1002 || + g.data_segs_in != 1 || g.data_segs_out != 1 || + (g.event_map ^ 0x47e) != 0 || g.bad_cb_test_rv != 0x80 || + g.good_cb_test_rv != 0) { + printf("FAILED: Wrong stats\n"); + if (debug_flag) { + printf("\n"); + printf("bytes_received: %d (expecting 501)\n", + (int)g.bytes_received); + printf("bytes_acked: %d (expecting 1002)\n", + (int)g.bytes_acked); + printf("data_segs_in: %d (expecting 1)\n", + g.data_segs_in); + printf("data_segs_out: %d (expecting 1)\n", + g.data_segs_out); + printf("event_map: 0x%x (at least 0x47e)\n", + g.event_map); + printf("bad_cb_test_rv: 0x%x (expecting 0x80)\n", + g.bad_cb_test_rv); + printf("good_cb_test_rv:0x%x (expecting 0)\n", + g.good_cb_test_rv); + } + goto err; + } + printf("PASSED!\n"); + error = 0; +err: + bpf_prog_detach(cg_fd, BPF_CGROUP_SOCK_OPS); + return error; + +}