From 5f4566498dee5e38e36a015a968c22ed21568f0b Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Fri, 8 Feb 2019 22:25:54 -0800 Subject: bpf: Fix narrow load on a bpf_sock returned from sk_lookup() By adding this test to test_verifier: { "reference tracking: access sk->src_ip4 (narrow load)", .insns = { BPF_SK_LOOKUP, BPF_MOV64_REG(BPF_REG_6, BPF_REG_0), BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3), BPF_LDX_MEM(BPF_H, BPF_REG_2, BPF_REG_0, offsetof(struct bpf_sock, src_ip4) + 2), BPF_MOV64_REG(BPF_REG_1, BPF_REG_6), BPF_EMIT_CALL(BPF_FUNC_sk_release), BPF_EXIT_INSN(), }, .prog_type = BPF_PROG_TYPE_SCHED_CLS, .result = ACCEPT, }, The above test loads 2 bytes from sk->src_ip4 where sk is obtained by bpf_sk_lookup_tcp(). It hits an internal verifier error from convert_ctx_accesses(): [root@arch-fb-vm1 bpf]# ./test_verifier 665 665 Failed to load prog 'Invalid argument'! 0: (b7) r2 = 0 1: (63) *(u32 *)(r10 -8) = r2 2: (7b) *(u64 *)(r10 -16) = r2 3: (7b) *(u64 *)(r10 -24) = r2 4: (7b) *(u64 *)(r10 -32) = r2 5: (7b) *(u64 *)(r10 -40) = r2 6: (7b) *(u64 *)(r10 -48) = r2 7: (bf) r2 = r10 8: (07) r2 += -48 9: (b7) r3 = 36 10: (b7) r4 = 0 11: (b7) r5 = 0 12: (85) call bpf_sk_lookup_tcp#84 13: (bf) r6 = r0 14: (15) if r0 == 0x0 goto pc+3 R0=sock(id=1,off=0,imm=0) R6=sock(id=1,off=0,imm=0) R10=fp0,call_-1 fp-8=????0000 fp-16=0000mmmm fp-24=mmmmmmmm fp-32=mmmmmmmm fp-40=mmmmmmmm fp-48=mmmmmmmm refs=1 15: (69) r2 = *(u16 *)(r0 +26) 16: (bf) r1 = r6 17: (85) call bpf_sk_release#86 18: (95) exit from 14 to 18: safe processed 20 insns (limit 131072), stack depth 48 bpf verifier is misconfigured Summary: 0 PASSED, 0 SKIPPED, 1 FAILED The bpf_sock_is_valid_access() is expecting src_ip4 can be narrowly loaded (meaning load any 1 or 2 bytes of the src_ip4) by marking info->ctx_field_size. However, this marked ctx_field_size is not used. This patch fixes it. Due to the recent refactoring in test_verifier, this new test will be added to the bpf-next branch (together with the bpf_tcp_sock patchset) to avoid merge conflict. Fixes: c64b7983288e ("bpf: Add PTR_TO_SOCKET verifier type") Cc: Joe Stringer Signed-off-by: Martin KaFai Lau Acked-by: Joe Stringer Signed-off-by: Alexei Starovoitov --- kernel/bpf/verifier.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index b63bc77af2d1..516dfc6d78de 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1640,12 +1640,13 @@ static int check_flow_keys_access(struct bpf_verifier_env *env, int off, return 0; } -static int check_sock_access(struct bpf_verifier_env *env, u32 regno, int off, - int size, enum bpf_access_type t) +static int check_sock_access(struct bpf_verifier_env *env, int insn_idx, + u32 regno, int off, int size, + enum bpf_access_type t) { struct bpf_reg_state *regs = cur_regs(env); struct bpf_reg_state *reg = ®s[regno]; - struct bpf_insn_access_aux info; + struct bpf_insn_access_aux info = {}; if (reg->smin_value < 0) { verbose(env, "R%d min value is negative, either use unsigned index or do a if (index >=0) check.\n", @@ -1659,6 +1660,8 @@ static int check_sock_access(struct bpf_verifier_env *env, u32 regno, int off, return -EACCES; } + env->insn_aux_data[insn_idx].ctx_field_size = info.ctx_field_size; + return 0; } @@ -2055,7 +2058,7 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn verbose(env, "cannot write into socket\n"); return -EACCES; } - err = check_sock_access(env, regno, off, size, t); + err = check_sock_access(env, insn_idx, regno, off, size, t); if (!err && value_regno >= 0) mark_reg_unknown(env, regs, value_regno); } else { -- cgit v1.2.3 From 46f8bc92758c6259bcf945e9216098661c1587cd Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Sat, 9 Feb 2019 23:22:20 -0800 Subject: bpf: Add a bpf_sock pointer to __sk_buff and a bpf_sk_fullsock helper In kernel, it is common to check "skb->sk && sk_fullsock(skb->sk)" before accessing the fields in sock. For example, in __netdev_pick_tx: static u16 __netdev_pick_tx(struct net_device *dev, struct sk_buff *skb, struct net_device *sb_dev) { /* ... */ struct sock *sk = skb->sk; if (queue_index != new_index && sk && sk_fullsock(sk) && rcu_access_pointer(sk->sk_dst_cache)) sk_tx_queue_set(sk, new_index); /* ... */ return queue_index; } This patch adds a "struct bpf_sock *sk" pointer to the "struct __sk_buff" where a few of the convert_ctx_access() in filter.c has already been accessing the skb->sk sock_common's fields, e.g. sock_ops_convert_ctx_access(). "__sk_buff->sk" is a PTR_TO_SOCK_COMMON_OR_NULL in the verifier. Some of the fileds in "bpf_sock" will not be directly accessible through the "__sk_buff->sk" pointer. It is limited by the new "bpf_sock_common_is_valid_access()". e.g. The existing "type", "protocol", "mark" and "priority" in bpf_sock are not allowed. The newly added "struct bpf_sock *bpf_sk_fullsock(struct bpf_sock *sk)" can be used to get a sk with all accessible fields in "bpf_sock". This helper is added to both cg_skb and sched_(cls|act). int cg_skb_foo(struct __sk_buff *skb) { struct bpf_sock *sk; sk = skb->sk; if (!sk) return 1; sk = bpf_sk_fullsock(sk); if (!sk) return 1; if (sk->family != AF_INET6 || sk->protocol != IPPROTO_TCP) return 1; /* some_traffic_shaping(); */ return 1; } (1) The sk is read only (2) There is no new "struct bpf_sock_common" introduced. (3) Future kernel sock's members could be added to bpf_sock only instead of repeatedly adding at multiple places like currently in bpf_sock_ops_md, bpf_sock_addr_md, sk_reuseport_md...etc. (4) After "sk = skb->sk", the reg holding sk is in type PTR_TO_SOCK_COMMON_OR_NULL. (5) After bpf_sk_fullsock(), the return type will be in type PTR_TO_SOCKET_OR_NULL which is the same as the return type of bpf_sk_lookup_xxx(). However, bpf_sk_fullsock() does not take refcnt. The acquire_reference_state() is only depending on the return type now. To avoid it, a new is_acquire_function() is checked before calling acquire_reference_state(). (6) The WARN_ON in "release_reference_state()" is no longer an internal verifier bug. When reg->id is not found in state->refs[], it means the bpf_prog does something wrong like "bpf_sk_release(bpf_sk_fullsock(skb->sk))" where reference has never been acquired by calling "bpf_sk_fullsock(skb->sk)". A -EINVAL and a verbose are done instead of WARN_ON. A test is added to the test_verifier in a later patch. Since the WARN_ON in "release_reference_state()" is no longer needed, "__release_reference_state()" is folded into "release_reference_state()" also. Acked-by: Alexei Starovoitov Signed-off-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov --- kernel/bpf/verifier.c | 132 +++++++++++++++++++++++++++++++++++--------------- 1 file changed, 92 insertions(+), 40 deletions(-) (limited to 'kernel') diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 516dfc6d78de..b755d55a3791 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -331,10 +331,17 @@ static bool type_is_pkt_pointer(enum bpf_reg_type type) type == PTR_TO_PACKET_META; } +static bool type_is_sk_pointer(enum bpf_reg_type type) +{ + return type == PTR_TO_SOCKET || + type == PTR_TO_SOCK_COMMON; +} + static bool reg_type_may_be_null(enum bpf_reg_type type) { return type == PTR_TO_MAP_VALUE_OR_NULL || - type == PTR_TO_SOCKET_OR_NULL; + type == PTR_TO_SOCKET_OR_NULL || + type == PTR_TO_SOCK_COMMON_OR_NULL; } static bool type_is_refcounted(enum bpf_reg_type type) @@ -377,6 +384,12 @@ static bool is_release_function(enum bpf_func_id func_id) return func_id == BPF_FUNC_sk_release; } +static bool is_acquire_function(enum bpf_func_id func_id) +{ + return func_id == BPF_FUNC_sk_lookup_tcp || + func_id == BPF_FUNC_sk_lookup_udp; +} + /* string representation of 'enum bpf_reg_type' */ static const char * const reg_type_str[] = { [NOT_INIT] = "?", @@ -392,6 +405,8 @@ static const char * const reg_type_str[] = { [PTR_TO_FLOW_KEYS] = "flow_keys", [PTR_TO_SOCKET] = "sock", [PTR_TO_SOCKET_OR_NULL] = "sock_or_null", + [PTR_TO_SOCK_COMMON] = "sock_common", + [PTR_TO_SOCK_COMMON_OR_NULL] = "sock_common_or_null", }; static char slot_type_char[] = { @@ -618,13 +633,10 @@ static int acquire_reference_state(struct bpf_verifier_env *env, int insn_idx) } /* release function corresponding to acquire_reference_state(). Idempotent. */ -static int __release_reference_state(struct bpf_func_state *state, int ptr_id) +static int release_reference_state(struct bpf_func_state *state, int ptr_id) { int i, last_idx; - if (!ptr_id) - return -EFAULT; - last_idx = state->acquired_refs - 1; for (i = 0; i < state->acquired_refs; i++) { if (state->refs[i].id == ptr_id) { @@ -636,21 +648,7 @@ static int __release_reference_state(struct bpf_func_state *state, int ptr_id) return 0; } } - return -EFAULT; -} - -/* variation on the above for cases where we expect that there must be an - * outstanding reference for the specified ptr_id. - */ -static int release_reference_state(struct bpf_verifier_env *env, int ptr_id) -{ - struct bpf_func_state *state = cur_func(env); - int err; - - err = __release_reference_state(state, ptr_id); - if (WARN_ON_ONCE(err != 0)) - verbose(env, "verifier internal error: can't release reference\n"); - return err; + return -EINVAL; } static int transfer_reference_state(struct bpf_func_state *dst, @@ -1209,6 +1207,8 @@ static bool is_spillable_regtype(enum bpf_reg_type type) case CONST_PTR_TO_MAP: case PTR_TO_SOCKET: case PTR_TO_SOCKET_OR_NULL: + case PTR_TO_SOCK_COMMON: + case PTR_TO_SOCK_COMMON_OR_NULL: return true; default: return false; @@ -1647,6 +1647,7 @@ static int check_sock_access(struct bpf_verifier_env *env, int insn_idx, struct bpf_reg_state *regs = cur_regs(env); struct bpf_reg_state *reg = ®s[regno]; struct bpf_insn_access_aux info = {}; + bool valid; if (reg->smin_value < 0) { verbose(env, "R%d min value is negative, either use unsigned index or do a if (index >=0) check.\n", @@ -1654,15 +1655,28 @@ static int check_sock_access(struct bpf_verifier_env *env, int insn_idx, return -EACCES; } - if (!bpf_sock_is_valid_access(off, size, t, &info)) { - verbose(env, "invalid bpf_sock access off=%d size=%d\n", - off, size); - return -EACCES; + switch (reg->type) { + case PTR_TO_SOCK_COMMON: + valid = bpf_sock_common_is_valid_access(off, size, t, &info); + break; + case PTR_TO_SOCKET: + valid = bpf_sock_is_valid_access(off, size, t, &info); + break; + default: + valid = false; } - env->insn_aux_data[insn_idx].ctx_field_size = info.ctx_field_size; - return 0; + if (valid) { + env->insn_aux_data[insn_idx].ctx_field_size = + info.ctx_field_size; + return 0; + } + + verbose(env, "R%d invalid %s access off=%d size=%d\n", + regno, reg_type_str[reg->type], off, size); + + return -EACCES; } static bool __is_pointer_value(bool allow_ptr_leaks, @@ -1688,8 +1702,14 @@ static bool is_ctx_reg(struct bpf_verifier_env *env, int regno) { const struct bpf_reg_state *reg = reg_state(env, regno); - return reg->type == PTR_TO_CTX || - reg->type == PTR_TO_SOCKET; + return reg->type == PTR_TO_CTX; +} + +static bool is_sk_reg(struct bpf_verifier_env *env, int regno) +{ + const struct bpf_reg_state *reg = reg_state(env, regno); + + return type_is_sk_pointer(reg->type); } static bool is_pkt_reg(struct bpf_verifier_env *env, int regno) @@ -1800,6 +1820,9 @@ static int check_ptr_alignment(struct bpf_verifier_env *env, case PTR_TO_SOCKET: pointer_desc = "sock "; break; + case PTR_TO_SOCK_COMMON: + pointer_desc = "sock_common "; + break; default: break; } @@ -2003,11 +2026,14 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn * PTR_TO_PACKET[_META,_END]. In the latter * case, we know the offset is zero. */ - if (reg_type == SCALAR_VALUE) + if (reg_type == SCALAR_VALUE) { mark_reg_unknown(env, regs, value_regno); - else + } else { mark_reg_known_zero(env, regs, value_regno); + if (reg_type_may_be_null(reg_type)) + regs[value_regno].id = ++env->id_gen; + } regs[value_regno].type = reg_type; } @@ -2053,9 +2079,10 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn err = check_flow_keys_access(env, off, size); if (!err && t == BPF_READ && value_regno >= 0) mark_reg_unknown(env, regs, value_regno); - } else if (reg->type == PTR_TO_SOCKET) { + } else if (type_is_sk_pointer(reg->type)) { if (t == BPF_WRITE) { - verbose(env, "cannot write into socket\n"); + verbose(env, "R%d cannot write into %s\n", + regno, reg_type_str[reg->type]); return -EACCES; } err = check_sock_access(env, insn_idx, regno, off, size, t); @@ -2102,7 +2129,8 @@ static int check_xadd(struct bpf_verifier_env *env, int insn_idx, struct bpf_ins if (is_ctx_reg(env, insn->dst_reg) || is_pkt_reg(env, insn->dst_reg) || - is_flow_key_reg(env, insn->dst_reg)) { + is_flow_key_reg(env, insn->dst_reg) || + is_sk_reg(env, insn->dst_reg)) { verbose(env, "BPF_XADD stores into R%d %s is not allowed\n", insn->dst_reg, reg_type_str[reg_state(env, insn->dst_reg)->type]); @@ -2369,6 +2397,11 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno, err = check_ctx_reg(env, reg, regno); if (err < 0) return err; + } else if (arg_type == ARG_PTR_TO_SOCK_COMMON) { + expected_type = PTR_TO_SOCK_COMMON; + /* Any sk pointer can be ARG_PTR_TO_SOCK_COMMON */ + if (!type_is_sk_pointer(type)) + goto err_type; } else if (arg_type == ARG_PTR_TO_SOCKET) { expected_type = PTR_TO_SOCKET; if (type != expected_type) @@ -2783,7 +2816,7 @@ static int release_reference(struct bpf_verifier_env *env, for (i = 0; i <= vstate->curframe; i++) release_reg_references(env, vstate->frame[i], meta->ptr_id); - return release_reference_state(env, meta->ptr_id); + return release_reference_state(cur_func(env), meta->ptr_id); } static int check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn, @@ -3049,8 +3082,11 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn } } else if (is_release_function(func_id)) { err = release_reference(env, &meta); - if (err) + if (err) { + verbose(env, "func %s#%d reference has not been acquired before\n", + func_id_name(func_id), func_id); return err; + } } regs = cur_regs(env); @@ -3099,12 +3135,19 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn regs[BPF_REG_0].id = ++env->id_gen; } } else if (fn->ret_type == RET_PTR_TO_SOCKET_OR_NULL) { - int id = acquire_reference_state(env, insn_idx); - if (id < 0) - return id; mark_reg_known_zero(env, regs, BPF_REG_0); regs[BPF_REG_0].type = PTR_TO_SOCKET_OR_NULL; - regs[BPF_REG_0].id = id; + if (is_acquire_function(func_id)) { + int id = acquire_reference_state(env, insn_idx); + + if (id < 0) + return id; + /* For release_reference() */ + regs[BPF_REG_0].id = id; + } else { + /* For mark_ptr_or_null_reg() */ + regs[BPF_REG_0].id = ++env->id_gen; + } } else { verbose(env, "unknown return type %d of func %s#%d\n", fn->ret_type, func_id_name(func_id), func_id); @@ -3364,6 +3407,8 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env, case PTR_TO_PACKET_END: case PTR_TO_SOCKET: case PTR_TO_SOCKET_OR_NULL: + case PTR_TO_SOCK_COMMON: + case PTR_TO_SOCK_COMMON_OR_NULL: verbose(env, "R%d pointer arithmetic on %s prohibited\n", dst, reg_type_str[ptr_reg->type]); return -EACCES; @@ -4597,6 +4642,8 @@ static void mark_ptr_or_null_reg(struct bpf_func_state *state, } } else if (reg->type == PTR_TO_SOCKET_OR_NULL) { reg->type = PTR_TO_SOCKET; + } else if (reg->type == PTR_TO_SOCK_COMMON_OR_NULL) { + reg->type = PTR_TO_SOCK_COMMON; } if (is_null || !(reg_is_refcounted(reg) || reg_may_point_to_spin_lock(reg))) { @@ -4621,7 +4668,7 @@ static void mark_ptr_or_null_regs(struct bpf_verifier_state *vstate, u32 regno, int i, j; if (reg_is_refcounted_or_null(®s[regno]) && is_null) - __release_reference_state(state, id); + release_reference_state(state, id); for (i = 0; i < MAX_BPF_REG; i++) mark_ptr_or_null_reg(state, ®s[i], id, is_null); @@ -5790,6 +5837,8 @@ static bool regsafe(struct bpf_reg_state *rold, struct bpf_reg_state *rcur, case PTR_TO_FLOW_KEYS: case PTR_TO_SOCKET: case PTR_TO_SOCKET_OR_NULL: + case PTR_TO_SOCK_COMMON: + case PTR_TO_SOCK_COMMON_OR_NULL: /* Only valid matches are exact, which memcmp() above * would have accepted */ @@ -6110,6 +6159,8 @@ static bool reg_type_mismatch_ok(enum bpf_reg_type type) case PTR_TO_CTX: case PTR_TO_SOCKET: case PTR_TO_SOCKET_OR_NULL: + case PTR_TO_SOCK_COMMON: + case PTR_TO_SOCK_COMMON_OR_NULL: return false; default: return true; @@ -7112,6 +7163,7 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env) convert_ctx_access = ops->convert_ctx_access; break; case PTR_TO_SOCKET: + case PTR_TO_SOCK_COMMON: convert_ctx_access = bpf_sock_convert_ctx_access; break; default: -- cgit v1.2.3 From 655a51e536c09d15ffa3603b1b6fce2b45b85a1f Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Sat, 9 Feb 2019 23:22:24 -0800 Subject: bpf: Add struct bpf_tcp_sock and BPF_FUNC_tcp_sock This patch adds a helper function BPF_FUNC_tcp_sock and it is currently available for cg_skb and sched_(cls|act): struct bpf_tcp_sock *bpf_tcp_sock(struct bpf_sock *sk); int cg_skb_foo(struct __sk_buff *skb) { struct bpf_tcp_sock *tp; struct bpf_sock *sk; __u32 snd_cwnd; sk = skb->sk; if (!sk) return 1; tp = bpf_tcp_sock(sk); if (!tp) return 1; snd_cwnd = tp->snd_cwnd; /* ... */ return 1; } A 'struct bpf_tcp_sock' is also added to the uapi bpf.h to provide read-only access. bpf_tcp_sock has all the existing tcp_sock's fields that has already been exposed by the bpf_sock_ops. i.e. no new tcp_sock's fields are exposed in bpf.h. This helper returns a pointer to the tcp_sock. If it is not a tcp_sock or it cannot be traced back to a tcp_sock by sk_to_full_sk(), it returns NULL. Hence, the caller needs to check for NULL before accessing it. The current use case is to expose members from tcp_sock to allow a cg_skb_bpf_prog to provide per cgroup traffic policing/shaping. Acked-by: Alexei Starovoitov Signed-off-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov --- kernel/bpf/verifier.c | 31 +++++++++++++++++++++++++++++-- 1 file changed, 29 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index b755d55a3791..1b9496c41383 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -334,14 +334,16 @@ static bool type_is_pkt_pointer(enum bpf_reg_type type) static bool type_is_sk_pointer(enum bpf_reg_type type) { return type == PTR_TO_SOCKET || - type == PTR_TO_SOCK_COMMON; + type == PTR_TO_SOCK_COMMON || + type == PTR_TO_TCP_SOCK; } static bool reg_type_may_be_null(enum bpf_reg_type type) { return type == PTR_TO_MAP_VALUE_OR_NULL || type == PTR_TO_SOCKET_OR_NULL || - type == PTR_TO_SOCK_COMMON_OR_NULL; + type == PTR_TO_SOCK_COMMON_OR_NULL || + type == PTR_TO_TCP_SOCK_OR_NULL; } static bool type_is_refcounted(enum bpf_reg_type type) @@ -407,6 +409,8 @@ static const char * const reg_type_str[] = { [PTR_TO_SOCKET_OR_NULL] = "sock_or_null", [PTR_TO_SOCK_COMMON] = "sock_common", [PTR_TO_SOCK_COMMON_OR_NULL] = "sock_common_or_null", + [PTR_TO_TCP_SOCK] = "tcp_sock", + [PTR_TO_TCP_SOCK_OR_NULL] = "tcp_sock_or_null", }; static char slot_type_char[] = { @@ -1209,6 +1213,8 @@ static bool is_spillable_regtype(enum bpf_reg_type type) case PTR_TO_SOCKET_OR_NULL: case PTR_TO_SOCK_COMMON: case PTR_TO_SOCK_COMMON_OR_NULL: + case PTR_TO_TCP_SOCK: + case PTR_TO_TCP_SOCK_OR_NULL: return true; default: return false; @@ -1662,6 +1668,9 @@ static int check_sock_access(struct bpf_verifier_env *env, int insn_idx, case PTR_TO_SOCKET: valid = bpf_sock_is_valid_access(off, size, t, &info); break; + case PTR_TO_TCP_SOCK: + valid = bpf_tcp_sock_is_valid_access(off, size, t, &info); + break; default: valid = false; } @@ -1823,6 +1832,9 @@ static int check_ptr_alignment(struct bpf_verifier_env *env, case PTR_TO_SOCK_COMMON: pointer_desc = "sock_common "; break; + case PTR_TO_TCP_SOCK: + pointer_desc = "tcp_sock "; + break; default: break; } @@ -3148,6 +3160,10 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn /* For mark_ptr_or_null_reg() */ regs[BPF_REG_0].id = ++env->id_gen; } + } else if (fn->ret_type == RET_PTR_TO_TCP_SOCK_OR_NULL) { + mark_reg_known_zero(env, regs, BPF_REG_0); + regs[BPF_REG_0].type = PTR_TO_TCP_SOCK_OR_NULL; + regs[BPF_REG_0].id = ++env->id_gen; } else { verbose(env, "unknown return type %d of func %s#%d\n", fn->ret_type, func_id_name(func_id), func_id); @@ -3409,6 +3425,8 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env, case PTR_TO_SOCKET_OR_NULL: case PTR_TO_SOCK_COMMON: case PTR_TO_SOCK_COMMON_OR_NULL: + case PTR_TO_TCP_SOCK: + case PTR_TO_TCP_SOCK_OR_NULL: verbose(env, "R%d pointer arithmetic on %s prohibited\n", dst, reg_type_str[ptr_reg->type]); return -EACCES; @@ -4644,6 +4662,8 @@ static void mark_ptr_or_null_reg(struct bpf_func_state *state, reg->type = PTR_TO_SOCKET; } else if (reg->type == PTR_TO_SOCK_COMMON_OR_NULL) { reg->type = PTR_TO_SOCK_COMMON; + } else if (reg->type == PTR_TO_TCP_SOCK_OR_NULL) { + reg->type = PTR_TO_TCP_SOCK; } if (is_null || !(reg_is_refcounted(reg) || reg_may_point_to_spin_lock(reg))) { @@ -5839,6 +5859,8 @@ static bool regsafe(struct bpf_reg_state *rold, struct bpf_reg_state *rcur, case PTR_TO_SOCKET_OR_NULL: case PTR_TO_SOCK_COMMON: case PTR_TO_SOCK_COMMON_OR_NULL: + case PTR_TO_TCP_SOCK: + case PTR_TO_TCP_SOCK_OR_NULL: /* Only valid matches are exact, which memcmp() above * would have accepted */ @@ -6161,6 +6183,8 @@ static bool reg_type_mismatch_ok(enum bpf_reg_type type) case PTR_TO_SOCKET_OR_NULL: case PTR_TO_SOCK_COMMON: case PTR_TO_SOCK_COMMON_OR_NULL: + case PTR_TO_TCP_SOCK: + case PTR_TO_TCP_SOCK_OR_NULL: return false; default: return true; @@ -7166,6 +7190,9 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env) case PTR_TO_SOCK_COMMON: convert_ctx_access = bpf_sock_convert_ctx_access; break; + case PTR_TO_TCP_SOCK: + convert_ctx_access = bpf_tcp_sock_convert_ctx_access; + break; default: continue; } -- cgit v1.2.3 From dd27c2e3d0a05c01ff14bb672d1a3f0fdd8f98fc Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Tue, 12 Feb 2019 00:20:39 -0800 Subject: bpf: offload: add priv field for drivers Currently bpf_offload_dev does not have any priv pointer, forcing the drivers to work backwards from the netdev in program metadata. This is not great given programs are conceptually associated with the offload device, and it means one or two unnecessary deferences. Add a priv pointer to bpf_offload_dev. Signed-off-by: Jakub Kicinski Reviewed-by: Quentin Monnet Signed-off-by: Daniel Borkmann --- kernel/bpf/offload.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c index 39dba8c90331..ba635209ae9a 100644 --- a/kernel/bpf/offload.c +++ b/kernel/bpf/offload.c @@ -35,6 +35,7 @@ static DECLARE_RWSEM(bpf_devs_lock); struct bpf_offload_dev { const struct bpf_prog_offload_ops *ops; struct list_head netdevs; + void *priv; }; struct bpf_offload_netdev { @@ -669,7 +670,7 @@ unlock: EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_unregister); struct bpf_offload_dev * -bpf_offload_dev_create(const struct bpf_prog_offload_ops *ops) +bpf_offload_dev_create(const struct bpf_prog_offload_ops *ops, void *priv) { struct bpf_offload_dev *offdev; int err; @@ -688,6 +689,7 @@ bpf_offload_dev_create(const struct bpf_prog_offload_ops *ops) return ERR_PTR(-ENOMEM); offdev->ops = ops; + offdev->priv = priv; INIT_LIST_HEAD(&offdev->netdevs); return offdev; @@ -700,3 +702,9 @@ void bpf_offload_dev_destroy(struct bpf_offload_dev *offdev) kfree(offdev); } EXPORT_SYMBOL_GPL(bpf_offload_dev_destroy); + +void *bpf_offload_dev_priv(struct bpf_offload_dev *offdev) +{ + return offdev->priv; +} +EXPORT_SYMBOL_GPL(bpf_offload_dev_priv); -- cgit v1.2.3