diff --git a/include/net/bpf_sk_storage.h b/include/net/bpf_sk_storage.h index 3c516dd07cafd..0e85713f56df3 100644 --- a/include/net/bpf_sk_storage.h +++ b/include/net/bpf_sk_storage.h @@ -20,6 +20,8 @@ void bpf_sk_storage_free(struct sock *sk); extern const struct bpf_func_proto bpf_sk_storage_get_proto; extern const struct bpf_func_proto bpf_sk_storage_delete_proto; +extern const struct bpf_func_proto bpf_sk_storage_get_tracing_proto; +extern const struct bpf_func_proto bpf_sk_storage_delete_tracing_proto; struct bpf_local_storage_elem; struct bpf_sk_storage_diag; diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index e4515b0f62a8d..cfce60ad1cb5c 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include @@ -1735,6 +1736,10 @@ tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_skc_to_tcp_request_sock_proto; case BPF_FUNC_skc_to_udp6_sock: return &bpf_skc_to_udp6_sock_proto; + case BPF_FUNC_sk_storage_get: + return &bpf_sk_storage_get_tracing_proto; + case BPF_FUNC_sk_storage_delete: + return &bpf_sk_storage_delete_tracing_proto; #endif case BPF_FUNC_seq_printf: return prog->expected_attach_type == BPF_TRACE_ITER ? diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c index c907f0dc7f87a..359908a7d3c12 100644 --- a/net/core/bpf_sk_storage.c +++ b/net/core/bpf_sk_storage.c @@ -6,6 +6,7 @@ #include #include #include +#include #include #include #include @@ -15,20 +16,8 @@ DEFINE_BPF_STORAGE_CACHE(sk_cache); -static int omem_charge(struct sock *sk, unsigned int size) -{ - /* same check as in sock_kmalloc() */ - if (size <= sysctl_optmem_max && - atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) { - atomic_add(size, &sk->sk_omem_alloc); - return 0; - } - - return -ENOMEM; -} - static struct bpf_local_storage_data * -sk_storage_lookup(struct sock *sk, struct bpf_map *map, bool cacheit_lockit) +bpf_sk_storage_lookup(struct sock *sk, struct bpf_map *map, bool cacheit_lockit) { struct bpf_local_storage *sk_storage; struct bpf_local_storage_map *smap; @@ -41,11 +30,11 @@ sk_storage_lookup(struct sock *sk, struct bpf_map *map, bool cacheit_lockit) return bpf_local_storage_lookup(sk_storage, smap, cacheit_lockit); } -static int sk_storage_delete(struct sock *sk, struct bpf_map *map) +static int bpf_sk_storage_del(struct sock *sk, struct bpf_map *map) { struct bpf_local_storage_data *sdata; - sdata = sk_storage_lookup(sk, map, false); + sdata = bpf_sk_storage_lookup(sk, map, false); if (!sdata) return -ENOENT; @@ -94,7 +83,7 @@ void bpf_sk_storage_free(struct sock *sk) kfree_rcu(sk_storage, rcu); } -static void sk_storage_map_free(struct bpf_map *map) +static void bpf_sk_storage_map_free(struct bpf_map *map) { struct bpf_local_storage_map *smap; @@ -103,7 +92,7 @@ static void sk_storage_map_free(struct bpf_map *map) bpf_local_storage_map_free(smap); } -static struct bpf_map *sk_storage_map_alloc(union bpf_attr *attr) +static struct bpf_map *bpf_sk_storage_map_alloc(union bpf_attr *attr) { struct bpf_local_storage_map *smap; @@ -130,7 +119,7 @@ static void *bpf_fd_sk_storage_lookup_elem(struct bpf_map *map, void *key) fd = *(int *)key; sock = sockfd_lookup(fd, &err); if (sock) { - sdata = sk_storage_lookup(sock->sk, map, true); + sdata = bpf_sk_storage_lookup(sock->sk, map, true); sockfd_put(sock); return sdata ? sdata->data : NULL; } @@ -166,7 +155,7 @@ static int bpf_fd_sk_storage_delete_elem(struct bpf_map *map, void *key) fd = *(int *)key; sock = sockfd_lookup(fd, &err); if (sock) { - err = sk_storage_delete(sock->sk, map); + err = bpf_sk_storage_del(sock->sk, map); sockfd_put(sock); return err; } @@ -272,7 +261,7 @@ BPF_CALL_4(bpf_sk_storage_get, struct bpf_map *, map, struct sock *, sk, if (!sk || !sk_fullsock(sk) || flags > BPF_SK_STORAGE_GET_F_CREATE) return (unsigned long)NULL; - sdata = sk_storage_lookup(sk, map, true); + sdata = bpf_sk_storage_lookup(sk, map, true); if (sdata) return (unsigned long)sdata->data; @@ -305,7 +294,7 @@ BPF_CALL_2(bpf_sk_storage_delete, struct bpf_map *, map, struct sock *, sk) if (refcount_inc_not_zero(&sk->sk_refcnt)) { int err; - err = sk_storage_delete(sk, map); + err = bpf_sk_storage_del(sk, map); sock_put(sk); return err; } @@ -313,14 +302,23 @@ BPF_CALL_2(bpf_sk_storage_delete, struct bpf_map *, map, struct sock *, sk) return -ENOENT; } -static int sk_storage_charge(struct bpf_local_storage_map *smap, - void *owner, u32 size) +static int bpf_sk_storage_charge(struct bpf_local_storage_map *smap, + void *owner, u32 size) { - return omem_charge(owner, size); + struct sock *sk = (struct sock *)owner; + + /* same check as in sock_kmalloc() */ + if (size <= sysctl_optmem_max && + atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) { + atomic_add(size, &sk->sk_omem_alloc); + return 0; + } + + return -ENOMEM; } -static void sk_storage_uncharge(struct bpf_local_storage_map *smap, - void *owner, u32 size) +static void bpf_sk_storage_uncharge(struct bpf_local_storage_map *smap, + void *owner, u32 size) { struct sock *sk = owner; @@ -328,7 +326,7 @@ static void sk_storage_uncharge(struct bpf_local_storage_map *smap, } static struct bpf_local_storage __rcu ** -sk_storage_ptr(void *owner) +bpf_sk_storage_ptr(void *owner) { struct sock *sk = owner; @@ -339,8 +337,8 @@ static int sk_storage_map_btf_id; const struct bpf_map_ops sk_storage_map_ops = { .map_meta_equal = bpf_map_meta_equal, .map_alloc_check = bpf_local_storage_map_alloc_check, - .map_alloc = sk_storage_map_alloc, - .map_free = sk_storage_map_free, + .map_alloc = bpf_sk_storage_map_alloc, + .map_free = bpf_sk_storage_map_free, .map_get_next_key = notsupp_get_next_key, .map_lookup_elem = bpf_fd_sk_storage_lookup_elem, .map_update_elem = bpf_fd_sk_storage_update_elem, @@ -348,9 +346,9 @@ const struct bpf_map_ops sk_storage_map_ops = { .map_check_btf = bpf_local_storage_map_check_btf, .map_btf_name = "bpf_local_storage_map", .map_btf_id = &sk_storage_map_btf_id, - .map_local_storage_charge = sk_storage_charge, - .map_local_storage_uncharge = sk_storage_uncharge, - .map_owner_storage_ptr = sk_storage_ptr, + .map_local_storage_charge = bpf_sk_storage_charge, + .map_local_storage_uncharge = bpf_sk_storage_uncharge, + .map_owner_storage_ptr = bpf_sk_storage_ptr, }; const struct bpf_func_proto bpf_sk_storage_get_proto = { @@ -381,6 +379,79 @@ const struct bpf_func_proto bpf_sk_storage_delete_proto = { .arg2_type = ARG_PTR_TO_BTF_ID_SOCK_COMMON, }; +static bool bpf_sk_storage_tracing_allowed(const struct bpf_prog *prog) +{ + const struct btf *btf_vmlinux; + const struct btf_type *t; + const char *tname; + u32 btf_id; + + if (prog->aux->dst_prog) + return false; + + /* Ensure the tracing program is not tracing + * any bpf_sk_storage*() function and also + * use the bpf_sk_storage_(get|delete) helper. + */ + switch (prog->expected_attach_type) { + case BPF_TRACE_RAW_TP: + /* bpf_sk_storage has no trace point */ + return true; + case BPF_TRACE_FENTRY: + case BPF_TRACE_FEXIT: + btf_vmlinux = bpf_get_btf_vmlinux(); + btf_id = prog->aux->attach_btf_id; + t = btf_type_by_id(btf_vmlinux, btf_id); + tname = btf_name_by_offset(btf_vmlinux, t->name_off); + return !!strncmp(tname, "bpf_sk_storage", + strlen("bpf_sk_storage")); + default: + return false; + } + + return false; +} + +BPF_CALL_4(bpf_sk_storage_get_tracing, struct bpf_map *, map, struct sock *, sk, + void *, value, u64, flags) +{ + if (!in_serving_softirq() && !in_task()) + return (unsigned long)NULL; + + return (unsigned long)____bpf_sk_storage_get(map, sk, value, flags); +} + +BPF_CALL_2(bpf_sk_storage_delete_tracing, struct bpf_map *, map, + struct sock *, sk) +{ + if (!in_serving_softirq() && !in_task()) + return -EPERM; + + return ____bpf_sk_storage_delete(map, sk); +} + +const struct bpf_func_proto bpf_sk_storage_get_tracing_proto = { + .func = bpf_sk_storage_get_tracing, + .gpl_only = false, + .ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL, + .arg1_type = ARG_CONST_MAP_PTR, + .arg2_type = ARG_PTR_TO_BTF_ID, + .arg2_btf_id = &btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON], + .arg3_type = ARG_PTR_TO_MAP_VALUE_OR_NULL, + .arg4_type = ARG_ANYTHING, + .allowed = bpf_sk_storage_tracing_allowed, +}; + +const struct bpf_func_proto bpf_sk_storage_delete_tracing_proto = { + .func = bpf_sk_storage_delete_tracing, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_CONST_MAP_PTR, + .arg2_type = ARG_PTR_TO_BTF_ID, + .arg2_btf_id = &btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON], + .allowed = bpf_sk_storage_tracing_allowed, +}; + struct bpf_sk_storage_diag { u32 nr_maps; struct bpf_map *maps[]; diff --git a/tools/testing/selftests/bpf/prog_tests/sk_storage_tracing.c b/tools/testing/selftests/bpf/prog_tests/sk_storage_tracing.c new file mode 100644 index 0000000000000..2b392590e8ca4 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/sk_storage_tracing.c @@ -0,0 +1,135 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Facebook */ + +#include +#include +#include +#include "test_progs.h" +#include "network_helpers.h" +#include "test_sk_storage_trace_itself.skel.h" +#include "test_sk_storage_tracing.skel.h" + +#define LO_ADDR6 "::1" +#define TEST_COMM "test_progs" + +struct sk_stg { + __u32 pid; + __u32 last_notclose_state; + char comm[16]; +}; + +static struct test_sk_storage_tracing *skel; +static __u32 duration; +static pid_t my_pid; + +static int check_sk_stg(int sk_fd, __u32 expected_state) +{ + struct sk_stg sk_stg; + int err; + + err = bpf_map_lookup_elem(bpf_map__fd(skel->maps.sk_stg_map), &sk_fd, + &sk_stg); + if (!ASSERT_OK(err, "map_lookup(sk_stg_map)")) + return -1; + + if (!ASSERT_EQ(sk_stg.last_notclose_state, expected_state, + "last_notclose_state")) + return -1; + + if (!ASSERT_EQ(sk_stg.pid, my_pid, "pid")) + return -1; + + if (!ASSERT_STREQ(sk_stg.comm, skel->bss->task_comm, "task_comm")) + return -1; + + return 0; +} + +static void do_test(void) +{ + int listen_fd = -1, passive_fd = -1, active_fd = -1, value = 1, err; + char abyte; + + listen_fd = start_server(AF_INET6, SOCK_STREAM, LO_ADDR6, 0, 0); + if (CHECK(listen_fd == -1, "start_server", + "listen_fd:%d errno:%d\n", listen_fd, errno)) + return; + + active_fd = connect_to_fd(listen_fd, 0); + if (CHECK(active_fd == -1, "connect_to_fd", "active_fd:%d errno:%d\n", + active_fd, errno)) + goto out; + + err = bpf_map_update_elem(bpf_map__fd(skel->maps.del_sk_stg_map), + &active_fd, &value, 0); + if (!ASSERT_OK(err, "map_update(del_sk_stg_map)")) + goto out; + + passive_fd = accept(listen_fd, NULL, 0); + if (CHECK(passive_fd == -1, "accept", "passive_fd:%d errno:%d\n", + passive_fd, errno)) + goto out; + + shutdown(active_fd, SHUT_WR); + err = read(passive_fd, &abyte, 1); + if (!ASSERT_OK(err, "read(passive_fd)")) + goto out; + + shutdown(passive_fd, SHUT_WR); + err = read(active_fd, &abyte, 1); + if (!ASSERT_OK(err, "read(active_fd)")) + goto out; + + err = bpf_map_lookup_elem(bpf_map__fd(skel->maps.del_sk_stg_map), + &active_fd, &value); + if (!ASSERT_ERR(err, "map_lookup(del_sk_stg_map)")) + goto out; + + err = check_sk_stg(listen_fd, BPF_TCP_LISTEN); + if (!ASSERT_OK(err, "listen_fd sk_stg")) + goto out; + + err = check_sk_stg(active_fd, BPF_TCP_FIN_WAIT2); + if (!ASSERT_OK(err, "active_fd sk_stg")) + goto out; + + err = check_sk_stg(passive_fd, BPF_TCP_LAST_ACK); + ASSERT_OK(err, "passive_fd sk_stg"); + +out: + if (active_fd != -1) + close(active_fd); + if (passive_fd != -1) + close(passive_fd); + if (listen_fd != -1) + close(listen_fd); +} + +void test_sk_storage_tracing(void) +{ + struct test_sk_storage_trace_itself *skel_itself; + int err; + + my_pid = getpid(); + + skel_itself = test_sk_storage_trace_itself__open_and_load(); + + if (!ASSERT_NULL(skel_itself, "test_sk_storage_trace_itself")) { + test_sk_storage_trace_itself__destroy(skel_itself); + return; + } + + skel = test_sk_storage_tracing__open_and_load(); + if (!ASSERT_OK_PTR(skel, "test_sk_storage_tracing")) + return; + + err = test_sk_storage_tracing__attach(skel); + if (!ASSERT_OK(err, "test_sk_storage_tracing__attach")) { + test_sk_storage_tracing__destroy(skel); + return; + } + + do_test(); + + test_sk_storage_tracing__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/test_sk_storage_trace_itself.c b/tools/testing/selftests/bpf/progs/test_sk_storage_trace_itself.c new file mode 100644 index 0000000000000..59ef72d02a61d --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_sk_storage_trace_itself.c @@ -0,0 +1,29 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Facebook */ + +#include +#include +#include + +struct { + __uint(type, BPF_MAP_TYPE_SK_STORAGE); + __uint(map_flags, BPF_F_NO_PREALLOC); + __type(key, int); + __type(value, int); +} sk_stg_map SEC(".maps"); + +SEC("fentry/bpf_sk_storage_free") +int BPF_PROG(trace_bpf_sk_storage_free, struct sock *sk) +{ + int *value; + + value = bpf_sk_storage_get(&sk_stg_map, sk, 0, + BPF_SK_STORAGE_GET_F_CREATE); + + if (value) + *value = 1; + + return 0; +} + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/progs/test_sk_storage_tracing.c b/tools/testing/selftests/bpf/progs/test_sk_storage_tracing.c new file mode 100644 index 0000000000000..8e94e5c080aae --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_sk_storage_tracing.c @@ -0,0 +1,95 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Facebook */ + +#include +#include +#include +#include + +struct sk_stg { + __u32 pid; + __u32 last_notclose_state; + char comm[16]; +}; + +struct { + __uint(type, BPF_MAP_TYPE_SK_STORAGE); + __uint(map_flags, BPF_F_NO_PREALLOC); + __type(key, int); + __type(value, struct sk_stg); +} sk_stg_map SEC(".maps"); + +/* Testing delete */ +struct { + __uint(type, BPF_MAP_TYPE_SK_STORAGE); + __uint(map_flags, BPF_F_NO_PREALLOC); + __type(key, int); + __type(value, int); +} del_sk_stg_map SEC(".maps"); + +char task_comm[16] = ""; + +SEC("tp_btf/inet_sock_set_state") +int BPF_PROG(trace_inet_sock_set_state, struct sock *sk, int oldstate, + int newstate) +{ + struct sk_stg *stg; + + if (newstate == BPF_TCP_CLOSE) + return 0; + + stg = bpf_sk_storage_get(&sk_stg_map, sk, 0, + BPF_SK_STORAGE_GET_F_CREATE); + if (!stg) + return 0; + + stg->last_notclose_state = newstate; + + bpf_sk_storage_delete(&del_sk_stg_map, sk); + + return 0; +} + +static void set_task_info(struct sock *sk) +{ + struct task_struct *task; + struct sk_stg *stg; + + stg = bpf_sk_storage_get(&sk_stg_map, sk, 0, + BPF_SK_STORAGE_GET_F_CREATE); + if (!stg) + return; + + stg->pid = bpf_get_current_pid_tgid(); + + task = (struct task_struct *)bpf_get_current_task(); + bpf_core_read_str(&stg->comm, sizeof(stg->comm), &task->comm); + bpf_core_read_str(&task_comm, sizeof(task_comm), &task->comm); +} + +SEC("fentry/inet_csk_listen_start") +int BPF_PROG(trace_inet_csk_listen_start, struct sock *sk, int backlog) +{ + set_task_info(sk); + + return 0; +} + +SEC("fentry/tcp_connect") +int BPF_PROG(trace_tcp_connect, struct sock *sk) +{ + set_task_info(sk); + + return 0; +} + +SEC("fexit/inet_csk_accept") +int BPF_PROG(inet_csk_accept, struct sock *sk, int flags, int *err, bool kern, + struct sock *accepted_sk) +{ + set_task_info(accepted_sk); + + return 0; +} + +char _license[] SEC("license") = "GPL";