diff options
| -rw-r--r-- | include/uapi/linux/bpf.h | 36 | ||||
| -rw-r--r-- | net/core/filter.c | 70 | ||||
| -rw-r--r-- | tools/include/uapi/linux/bpf.h | 36 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/network_helpers.c | 74 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/network_helpers.h | 2 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/cgroup_skb_sk_lookup.c | 95 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/progs/cgroup_skb_sk_lookup_kern.c | 97 |
7 files changed, 386 insertions, 24 deletions
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 85cfdffde182..146c742f1d49 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -3121,6 +3121,38 @@ union bpf_attr { * 0 on success, or a negative error in case of failure: * * **-EOVERFLOW** if an overflow happened: The same object will be tried again. + * + * u64 bpf_sk_cgroup_id(struct bpf_sock *sk) + * Description + * Return the cgroup v2 id of the socket *sk*. + * + * *sk* must be a non-**NULL** pointer to a full socket, e.g. one + * returned from **bpf_sk_lookup_xxx**\ (), + * **bpf_sk_fullsock**\ (), etc. The format of returned id is + * same as in **bpf_skb_cgroup_id**\ (). + * + * This helper is available only if the kernel was compiled with + * the **CONFIG_SOCK_CGROUP_DATA** configuration option. + * Return + * The id is returned or 0 in case the id could not be retrieved. + * + * u64 bpf_sk_ancestor_cgroup_id(struct bpf_sock *sk, int ancestor_level) + * Description + * Return id of cgroup v2 that is ancestor of cgroup associated + * with the *sk* at the *ancestor_level*. The root cgroup is at + * *ancestor_level* zero and each step down the hierarchy + * increments the level. If *ancestor_level* == level of cgroup + * associated with *sk*, then return value will be same as that + * of **bpf_sk_cgroup_id**\ (). + * + * The helper is useful to implement policies based on cgroups + * that are upper in hierarchy than immediate cgroup associated + * with *sk*. + * + * The format of returned id and helper limitations are same as in + * **bpf_sk_cgroup_id**\ (). + * Return + * The id is returned or 0 in case the id could not be retrieved. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -3250,7 +3282,9 @@ union bpf_attr { FN(sk_assign), \ FN(ktime_get_boot_ns), \ FN(seq_printf), \ - FN(seq_write), + FN(seq_write), \ + FN(sk_cgroup_id), \ + FN(sk_ancestor_cgroup_id), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call diff --git a/net/core/filter.c b/net/core/filter.c index 1fe8c0c2d408..5815902bb617 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4003,16 +4003,22 @@ static const struct bpf_func_proto bpf_skb_under_cgroup_proto = { }; #ifdef CONFIG_SOCK_CGROUP_DATA +static inline u64 __bpf_sk_cgroup_id(struct sock *sk) +{ + struct cgroup *cgrp; + + cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data); + return cgroup_id(cgrp); +} + BPF_CALL_1(bpf_skb_cgroup_id, const struct sk_buff *, skb) { struct sock *sk = skb_to_full_sk(skb); - struct cgroup *cgrp; if (!sk || !sk_fullsock(sk)) return 0; - cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data); - return cgroup_id(cgrp); + return __bpf_sk_cgroup_id(sk); } static const struct bpf_func_proto bpf_skb_cgroup_id_proto = { @@ -4022,16 +4028,12 @@ static const struct bpf_func_proto bpf_skb_cgroup_id_proto = { .arg1_type = ARG_PTR_TO_CTX, }; -BPF_CALL_2(bpf_skb_ancestor_cgroup_id, const struct sk_buff *, skb, int, - ancestor_level) +static inline u64 __bpf_sk_ancestor_cgroup_id(struct sock *sk, + int ancestor_level) { - struct sock *sk = skb_to_full_sk(skb); struct cgroup *ancestor; struct cgroup *cgrp; - if (!sk || !sk_fullsock(sk)) - return 0; - cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data); ancestor = cgroup_ancestor(cgrp, ancestor_level); if (!ancestor) @@ -4040,6 +4042,17 @@ BPF_CALL_2(bpf_skb_ancestor_cgroup_id, const struct sk_buff *, skb, int, return cgroup_id(ancestor); } +BPF_CALL_2(bpf_skb_ancestor_cgroup_id, const struct sk_buff *, skb, int, + ancestor_level) +{ + struct sock *sk = skb_to_full_sk(skb); + + if (!sk || !sk_fullsock(sk)) + return 0; + + return __bpf_sk_ancestor_cgroup_id(sk, ancestor_level); +} + static const struct bpf_func_proto bpf_skb_ancestor_cgroup_id_proto = { .func = bpf_skb_ancestor_cgroup_id, .gpl_only = false, @@ -4047,6 +4060,31 @@ static const struct bpf_func_proto bpf_skb_ancestor_cgroup_id_proto = { .arg1_type = ARG_PTR_TO_CTX, .arg2_type = ARG_ANYTHING, }; + +BPF_CALL_1(bpf_sk_cgroup_id, struct sock *, sk) +{ + return __bpf_sk_cgroup_id(sk); +} + +static const struct bpf_func_proto bpf_sk_cgroup_id_proto = { + .func = bpf_sk_cgroup_id, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_SOCKET, +}; + +BPF_CALL_2(bpf_sk_ancestor_cgroup_id, struct sock *, sk, int, ancestor_level) +{ + return __bpf_sk_ancestor_cgroup_id(sk, ancestor_level); +} + +static const struct bpf_func_proto bpf_sk_ancestor_cgroup_id_proto = { + .func = bpf_sk_ancestor_cgroup_id, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_SOCKET, + .arg2_type = ARG_ANYTHING, +}; #endif static unsigned long bpf_xdp_copy(void *dst_buff, const void *src_buff, @@ -6157,8 +6195,22 @@ cg_skb_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) #ifdef CONFIG_SOCK_CGROUP_DATA case BPF_FUNC_skb_cgroup_id: return &bpf_skb_cgroup_id_proto; + case BPF_FUNC_skb_ancestor_cgroup_id: + return &bpf_skb_ancestor_cgroup_id_proto; + case BPF_FUNC_sk_cgroup_id: + return &bpf_sk_cgroup_id_proto; + case BPF_FUNC_sk_ancestor_cgroup_id: + return &bpf_sk_ancestor_cgroup_id_proto; #endif #ifdef CONFIG_INET + case BPF_FUNC_sk_lookup_tcp: + return &bpf_sk_lookup_tcp_proto; + case BPF_FUNC_sk_lookup_udp: + return &bpf_sk_lookup_udp_proto; + case BPF_FUNC_sk_release: + return &bpf_sk_release_proto; + case BPF_FUNC_skc_lookup_tcp: + return &bpf_skc_lookup_tcp_proto; case BPF_FUNC_tcp_sock: return &bpf_tcp_sock_proto; case BPF_FUNC_get_listener_sock: diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 85cfdffde182..146c742f1d49 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -3121,6 +3121,38 @@ union bpf_attr { * 0 on success, or a negative error in case of failure: * * **-EOVERFLOW** if an overflow happened: The same object will be tried again. + * + * u64 bpf_sk_cgroup_id(struct bpf_sock *sk) + * Description + * Return the cgroup v2 id of the socket *sk*. + * + * *sk* must be a non-**NULL** pointer to a full socket, e.g. one + * returned from **bpf_sk_lookup_xxx**\ (), + * **bpf_sk_fullsock**\ (), etc. The format of returned id is + * same as in **bpf_skb_cgroup_id**\ (). + * + * This helper is available only if the kernel was compiled with + * the **CONFIG_SOCK_CGROUP_DATA** configuration option. + * Return + * The id is returned or 0 in case the id could not be retrieved. + * + * u64 bpf_sk_ancestor_cgroup_id(struct bpf_sock *sk, int ancestor_level) + * Description + * Return id of cgroup v2 that is ancestor of cgroup associated + * with the *sk* at the *ancestor_level*. The root cgroup is at + * *ancestor_level* zero and each step down the hierarchy + * increments the level. If *ancestor_level* == level of cgroup + * associated with *sk*, then return value will be same as that + * of **bpf_sk_cgroup_id**\ (). + * + * The helper is useful to implement policies based on cgroups + * that are upper in hierarchy than immediate cgroup associated + * with *sk*. + * + * The format of returned id and helper limitations are same as in + * **bpf_sk_cgroup_id**\ (). + * Return + * The id is returned or 0 in case the id could not be retrieved. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -3250,7 +3282,9 @@ union bpf_attr { FN(sk_assign), \ FN(ktime_get_boot_ns), \ FN(seq_printf), \ - FN(seq_write), + FN(seq_write), \ + FN(sk_cgroup_id), \ + FN(sk_ancestor_cgroup_id), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c index 0ff64b70b746..999a775484c1 100644 --- a/tools/testing/selftests/bpf/network_helpers.c +++ b/tools/testing/selftests/bpf/network_helpers.c @@ -4,10 +4,14 @@ #include <stdio.h> #include <string.h> #include <unistd.h> + +#include <sys/epoll.h> + #include <linux/err.h> #include <linux/in.h> #include <linux/in6.h> +#include "bpf_util.h" #include "network_helpers.h" #define clean_errno() (errno == 0 ? "None" : strerror(errno)) @@ -77,9 +81,7 @@ static const size_t timeo_optlen = sizeof(timeo_sec); int connect_to_fd(int family, int type, int server_fd) { - struct sockaddr_storage addr; - socklen_t len = sizeof(addr); - int fd; + int fd, save_errno; fd = socket(family, type, 0); if (fd < 0) { @@ -87,24 +89,70 @@ int connect_to_fd(int family, int type, int server_fd) return -1; } - if (setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &timeo_sec, timeo_optlen)) { + if (connect_fd_to_fd(fd, server_fd) < 0 && errno != EINPROGRESS) { + save_errno = errno; + close(fd); + errno = save_errno; + return -1; + } + + return fd; +} + +int connect_fd_to_fd(int client_fd, int server_fd) +{ + struct sockaddr_storage addr; + socklen_t len = sizeof(addr); + int save_errno; + + if (setsockopt(client_fd, SOL_SOCKET, SO_RCVTIMEO, &timeo_sec, + timeo_optlen)) { log_err("Failed to set SO_RCVTIMEO"); - goto out; + return -1; } if (getsockname(server_fd, (struct sockaddr *)&addr, &len)) { log_err("Failed to get server addr"); - goto out; + return -1; } - if (connect(fd, (const struct sockaddr *)&addr, len) < 0) { - log_err("Fail to connect to server with family %d", family); - goto out; + if (connect(client_fd, (const struct sockaddr *)&addr, len) < 0) { + if (errno != EINPROGRESS) { + save_errno = errno; + log_err("Failed to connect to server"); + errno = save_errno; + } + return -1; } - return fd; + return 0; +} + +int connect_wait(int fd) +{ + struct epoll_event ev = {}, events[2]; + int timeout_ms = 1000; + int efd, nfd; + + efd = epoll_create1(EPOLL_CLOEXEC); + if (efd < 0) { + log_err("Failed to open epoll fd"); + return -1; + } + + ev.events = EPOLLRDHUP | EPOLLOUT; + ev.data.fd = fd; + + if (epoll_ctl(efd, EPOLL_CTL_ADD, fd, &ev) < 0) { + log_err("Failed to register fd=%d on epoll fd=%d", fd, efd); + close(efd); + return -1; + } + + nfd = epoll_wait(efd, events, ARRAY_SIZE(events), timeout_ms); + if (nfd < 0) + log_err("Failed to wait for I/O event on epoll fd=%d", efd); -out: - close(fd); - return -1; + close(efd); + return nfd; } diff --git a/tools/testing/selftests/bpf/network_helpers.h b/tools/testing/selftests/bpf/network_helpers.h index a0be7db4f67d..86914e6e7b53 100644 --- a/tools/testing/selftests/bpf/network_helpers.h +++ b/tools/testing/selftests/bpf/network_helpers.h @@ -35,5 +35,7 @@ extern struct ipv6_packet pkt_v6; int start_server(int family, int type); int connect_to_fd(int family, int type, int server_fd); +int connect_fd_to_fd(int client_fd, int server_fd); +int connect_wait(int client_fd); #endif diff --git a/tools/testing/selftests/bpf/prog_tests/cgroup_skb_sk_lookup.c b/tools/testing/selftests/bpf/prog_tests/cgroup_skb_sk_lookup.c new file mode 100644 index 000000000000..059047af7df3 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/cgroup_skb_sk_lookup.c @@ -0,0 +1,95 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2020 Facebook + +#include <test_progs.h> + +#include "network_helpers.h" +#include "cgroup_skb_sk_lookup_kern.skel.h" + +static void run_lookup_test(__u16 *g_serv_port, int out_sk) +{ + int serv_sk = -1, in_sk = -1, serv_in_sk = -1, err; + struct sockaddr_in6 addr = {}; + socklen_t addr_len = sizeof(addr); + __u32 duration = 0; + + serv_sk = start_server(AF_INET6, SOCK_STREAM); + if (CHECK(serv_sk < 0, "start_server", "failed to start server\n")) + return; + + err = getsockname(serv_sk, (struct sockaddr *)&addr, &addr_len); + if (CHECK(err, "getsockname", "errno %d\n", errno)) + goto cleanup; + + *g_serv_port = addr.sin6_port; + + /* Client outside of test cgroup should fail to connect by timeout. */ + err = connect_fd_to_fd(out_sk, serv_sk); + if (CHECK(!err || errno != EINPROGRESS, "connect_fd_to_fd", + "unexpected result err %d errno %d\n", err, errno)) + goto cleanup; + + err = connect_wait(out_sk); + if (CHECK(err, "connect_wait", "unexpected result %d\n", err)) + goto cleanup; + + /* Client inside test cgroup should connect just fine. */ + in_sk = connect_to_fd(AF_INET6, SOCK_STREAM, serv_sk); + if (CHECK(in_sk < 0, "connect_to_fd", "errno %d\n", errno)) + goto cleanup; + + serv_in_sk = accept(serv_sk, NULL, NULL); + if (CHECK(serv_in_sk < 0, "accept", "errno %d\n", errno)) + goto cleanup; + +cleanup: + close(serv_in_sk); + close(in_sk); + close(serv_sk); +} + +static void run_cgroup_bpf_test(const char *cg_path, int out_sk) +{ + struct cgroup_skb_sk_lookup_kern *skel; + struct bpf_link *link; + __u32 duration = 0; + int cgfd = -1; + + skel = cgroup_skb_sk_lookup_kern__open_and_load(); + if (CHECK(!skel, "skel_open_load", "open_load failed\n")) + return; + + cgfd = test__join_cgroup(cg_path); + if (CHECK(cgfd < 0, "cgroup_join", "cgroup setup failed\n")) + goto cleanup; + + link = bpf_program__attach_cgroup(skel->progs.ingress_lookup, cgfd); + if (CHECK(IS_ERR(link), "cgroup_attach", "err: %ld\n", PTR_ERR(link))) + goto cleanup; + + run_lookup_test(&skel->bss->g_serv_port, out_sk); + + bpf_link__destroy(link); + +cleanup: + close(cgfd); + cgroup_skb_sk_lookup_kern__destroy(skel); +} + +void test_cgroup_skb_sk_lookup(void) +{ + const char *cg_path = "/foo"; + int out_sk; + + /* Create a socket before joining testing cgroup so that its cgroup id + * differs from that of testing cgroup. Moving selftests process to + * testing cgroup won't change cgroup id of an already created socket. + */ + out_sk = socket(AF_INET6, SOCK_STREAM | SOCK_NONBLOCK, 0); + if (CHECK_FAIL(out_sk < 0)) + return; + + run_cgroup_bpf_test(cg_path, out_sk); + + close(out_sk); +} diff --git a/tools/testing/selftests/bpf/progs/cgroup_skb_sk_lookup_kern.c b/tools/testing/selftests/bpf/progs/cgroup_skb_sk_lookup_kern.c new file mode 100644 index 000000000000..3f757e30d7a0 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/cgroup_skb_sk_lookup_kern.c @@ -0,0 +1,97 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2020 Facebook + +#include <linux/bpf.h> +#include <bpf/bpf_endian.h> +#include <bpf/bpf_helpers.h> + +#include <linux/if_ether.h> +#include <linux/in.h> +#include <linux/in6.h> +#include <linux/ipv6.h> +#include <linux/tcp.h> + +#include <sys/types.h> +#include <sys/socket.h> + +int _version SEC("version") = 1; +char _license[] SEC("license") = "GPL"; + +__u16 g_serv_port = 0; + +static inline void set_ip(__u32 *dst, const struct in6_addr *src) +{ + dst[0] = src->in6_u.u6_addr32[0]; + dst[1] = src->in6_u.u6_addr32[1]; + dst[2] = src->in6_u.u6_addr32[2]; + dst[3] = src->in6_u.u6_addr32[3]; +} + +static inline void set_tuple(struct bpf_sock_tuple *tuple, + const struct ipv6hdr *ip6h, + const struct tcphdr *tcph) +{ + set_ip(tuple->ipv6.saddr, &ip6h->daddr); + set_ip(tuple->ipv6.daddr, &ip6h->saddr); + tuple->ipv6.sport = tcph->dest; + tuple->ipv6.dport = tcph->source; +} + +static inline int is_allowed_peer_cg(struct __sk_buff *skb, + const struct ipv6hdr *ip6h, + const struct tcphdr *tcph) +{ + __u64 cgid, acgid, peer_cgid, peer_acgid; + struct bpf_sock_tuple tuple; + size_t tuple_len = sizeof(tuple.ipv6); + struct bpf_sock *peer_sk; + + set_tuple(&tuple, ip6h, tcph); + + peer_sk = bpf_sk_lookup_tcp(skb, &tuple, tuple_len, + BPF_F_CURRENT_NETNS, 0); + if (!peer_sk) + return 0; + + cgid = bpf_skb_cgroup_id(skb); + peer_cgid = bpf_sk_cgroup_id(peer_sk); + + acgid = bpf_skb_ancestor_cgroup_id(skb, 2); + peer_acgid = bpf_sk_ancestor_cgroup_id(peer_sk, 2); + + bpf_sk_release(peer_sk); + + return cgid && cgid == peer_cgid && acgid && acgid == peer_acgid; +} + +SEC("cgroup_skb/ingress") +int ingress_lookup(struct __sk_buff *skb) +{ + __u32 serv_port_key = 0; + struct ipv6hdr ip6h; + struct tcphdr tcph; + + if (skb->protocol != bpf_htons(ETH_P_IPV6)) + return 1; + + /* For SYN packets coming to listening socket skb->remote_port will be + * zero, so IPv6/TCP headers are loaded to identify remote peer + * instead. + */ + if (bpf_skb_load_bytes(skb, 0, &ip6h, sizeof(ip6h))) + return 1; + + if (ip6h.nexthdr != IPPROTO_TCP) + return 1; + + if (bpf_skb_load_bytes(skb, sizeof(ip6h), &tcph, sizeof(tcph))) + return 1; + + if (!g_serv_port) + return 0; + + if (tcph.dest != g_serv_port) + return 1; + + return is_allowed_peer_cg(skb, &ip6h, &tcph); +} |