From d7be143b67c2cf99bf93279217b1cf93a1e8a6b1 Mon Sep 17 00:00:00 2001 From: Andrey Ignatov Date: Fri, 30 Mar 2018 15:08:01 -0700 Subject: libbpf: Support expected_attach_type at prog load Support setting `expected_attach_type` at prog load time in both `bpf/bpf.h` and `bpf/libbpf.h`. Since both headers already have API to load programs, new functions are added not to break backward compatibility for existing ones: * `bpf_load_program_xattr()` is added to `bpf/bpf.h`; * `bpf_prog_load_xattr()` is added to `bpf/libbpf.h`. Both new functions accept structures, `struct bpf_load_program_attr` and `struct bpf_prog_load_attr` correspondingly, where new fields can be added in the future w/o changing the API. Standard `_xattr` suffix is used to name the new API functions. Since `bpf_load_program_name()` is not used as heavily as `bpf_load_program()`, it was removed in favor of more generic `bpf_load_program_xattr()`. Signed-off-by: Andrey Ignatov Signed-off-by: Alexei Starovoitov Signed-off-by: Daniel Borkmann --- tools/include/uapi/linux/bpf.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'tools/include/uapi') diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 58060bec999d..e1c1fed63396 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -296,6 +296,11 @@ union bpf_attr { __u32 prog_flags; char prog_name[BPF_OBJ_NAME_LEN]; __u32 prog_ifindex; /* ifindex of netdev to prep for */ + /* For some prog types expected attach type must be known at + * load time to verify attach type specific parts of prog + * (context accesses, allowed helpers, etc). + */ + __u32 expected_attach_type; }; struct { /* anonymous struct used by BPF_OBJ_* commands */ -- cgit v1.2.3 From e50b0a6f089308bec6b2d0198abed231dee4d277 Mon Sep 17 00:00:00 2001 From: Andrey Ignatov Date: Fri, 30 Mar 2018 15:08:03 -0700 Subject: selftests/bpf: Selftest for sys_bind hooks Add selftest to work with bpf_sock_addr context from `BPF_PROG_TYPE_CGROUP_SOCK_ADDR` programs. Try to bind(2) on IP:port and apply: * loads to make sure context can be read correctly, including narrow loads (byte, half) for IP and full-size loads (word) for all fields; * stores to those fields allowed by verifier. All combination from IPv4/IPv6 and TCP/UDP are tested. Both scenarios are tested: * valid programs can be loaded and attached; * invalid programs can be neither loaded nor attached. Test passes when expected data can be read from context in the BPF-program, and after the call to bind(2) socket is bound to IP:port pair that was written by BPF-program to the context. Example: # ./test_sock_addr Attached bind4 program. Test case #1 (IPv4/TCP): Requested: bind(192.168.1.254, 4040) .. Actual: bind(127.0.0.1, 4444) Test case #2 (IPv4/UDP): Requested: bind(192.168.1.254, 4040) .. Actual: bind(127.0.0.1, 4444) Attached bind6 program. Test case #3 (IPv6/TCP): Requested: bind(face:b00c:1234:5678::abcd, 6060) .. Actual: bind(::1, 6666) Test case #4 (IPv6/UDP): Requested: bind(face:b00c:1234:5678::abcd, 6060) .. Actual: bind(::1, 6666) ### SUCCESS Signed-off-by: Andrey Ignatov Signed-off-by: Alexei Starovoitov Signed-off-by: Daniel Borkmann --- tools/include/uapi/linux/bpf.h | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'tools/include/uapi') diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index e1c1fed63396..f2120c5c0578 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -136,6 +136,7 @@ enum bpf_prog_type { BPF_PROG_TYPE_CGROUP_DEVICE, BPF_PROG_TYPE_SK_MSG, BPF_PROG_TYPE_RAW_TRACEPOINT, + BPF_PROG_TYPE_CGROUP_SOCK_ADDR, }; enum bpf_attach_type { @@ -147,6 +148,8 @@ enum bpf_attach_type { BPF_SK_SKB_STREAM_VERDICT, BPF_CGROUP_DEVICE, BPF_SK_MSG_VERDICT, + BPF_CGROUP_INET4_BIND, + BPF_CGROUP_INET6_BIND, __MAX_BPF_ATTACH_TYPE }; @@ -1009,6 +1012,26 @@ struct bpf_map_info { __u64 netns_ino; } __attribute__((aligned(8))); +/* User bpf_sock_addr struct to access socket fields and sockaddr struct passed + * by user and intended to be used by socket (e.g. to bind to, depends on + * attach attach type). + */ +struct bpf_sock_addr { + __u32 user_family; /* Allows 4-byte read, but no write. */ + __u32 user_ip4; /* Allows 1,2,4-byte read and 4-byte write. + * Stored in network byte order. + */ + __u32 user_ip6[4]; /* Allows 1,2,4-byte read an 4-byte write. + * Stored in network byte order. + */ + __u32 user_port; /* Allows 4-byte read and write. + * Stored in network byte order + */ + __u32 family; /* Allows 4-byte read, but no write */ + __u32 type; /* Allows 4-byte read, but no write */ + __u32 protocol; /* Allows 4-byte read, but no write */ +}; + /* User bpf_sock_ops struct to access socket values and specify request ops * and their replies. * Some of this fields are in network (bigendian) byte order and may need -- cgit v1.2.3 From 622adafb2a12cac6042d4d0d7eb735b7621bf28c Mon Sep 17 00:00:00 2001 From: Andrey Ignatov Date: Fri, 30 Mar 2018 15:08:06 -0700 Subject: selftests/bpf: Selftest for sys_connect hooks Add selftest for BPF_CGROUP_INET4_CONNECT and BPF_CGROUP_INET6_CONNECT attach types. Try to connect(2) to specified IP:port and test that: * remote IP:port pair is overridden; * local end of connection is bound to specified IP. All combinations of IPv4/IPv6 and TCP/UDP are tested. Example: # tcpdump -pn -i lo -w connect.pcap 2>/dev/null & [1] 478 # strace -qqf -e connect -o connect.trace ./test_sock_addr.sh Wait for testing IPv4/IPv6 to become available ... OK Load bind4 with invalid type (can pollute stderr) ... REJECTED Load bind4 with valid type ... OK Attach bind4 with invalid type ... REJECTED Attach bind4 with valid type ... OK Load connect4 with invalid type (can pollute stderr) libbpf: load bpf \ program failed: Permission denied libbpf: -- BEGIN DUMP LOG --- libbpf: 0: (b7) r2 = 23569 1: (63) *(u32 *)(r1 +24) = r2 2: (b7) r2 = 16777343 3: (63) *(u32 *)(r1 +4) = r2 invalid bpf_context access off=4 size=4 [ 1518.404609] random: crng init done libbpf: -- END LOG -- libbpf: failed to load program 'cgroup/connect4' libbpf: failed to load object './connect4_prog.o' ... REJECTED Load connect4 with valid type ... OK Attach connect4 with invalid type ... REJECTED Attach connect4 with valid type ... OK Test case #1 (IPv4/TCP): Requested: bind(192.168.1.254, 4040) .. Actual: bind(127.0.0.1, 4444) Requested: connect(192.168.1.254, 4040) from (*, *) .. Actual: connect(127.0.0.1, 4444) from (127.0.0.4, 56068) Test case #2 (IPv4/UDP): Requested: bind(192.168.1.254, 4040) .. Actual: bind(127.0.0.1, 4444) Requested: connect(192.168.1.254, 4040) from (*, *) .. Actual: connect(127.0.0.1, 4444) from (127.0.0.4, 56447) Load bind6 with invalid type (can pollute stderr) ... REJECTED Load bind6 with valid type ... OK Attach bind6 with invalid type ... REJECTED Attach bind6 with valid type ... OK Load connect6 with invalid type (can pollute stderr) libbpf: load bpf \ program failed: Permission denied libbpf: -- BEGIN DUMP LOG --- libbpf: 0: (b7) r6 = 0 1: (63) *(u32 *)(r1 +12) = r6 invalid bpf_context access off=12 size=4 libbpf: -- END LOG -- libbpf: failed to load program 'cgroup/connect6' libbpf: failed to load object './connect6_prog.o' ... REJECTED Load connect6 with valid type ... OK Attach connect6 with invalid type ... REJECTED Attach connect6 with valid type ... OK Test case #3 (IPv6/TCP): Requested: bind(face:b00c:1234:5678::abcd, 6060) .. Actual: bind(::1, 6666) Requested: connect(face:b00c:1234:5678::abcd, 6060) from (*, *) Actual: connect(::1, 6666) from (::6, 37458) Test case #4 (IPv6/UDP): Requested: bind(face:b00c:1234:5678::abcd, 6060) .. Actual: bind(::1, 6666) Requested: connect(face:b00c:1234:5678::abcd, 6060) from (*, *) Actual: connect(::1, 6666) from (::6, 39315) ### SUCCESS # egrep 'connect\(.*AF_INET' connect.trace | \ > egrep -vw 'htons\(1025\)' | fold -b -s -w 72 502 connect(7, {sa_family=AF_INET, sin_port=htons(4040), sin_addr=inet_addr("192.168.1.254")}, 128) = 0 502 connect(8, {sa_family=AF_INET, sin_port=htons(4040), sin_addr=inet_addr("192.168.1.254")}, 128) = 0 502 connect(9, {sa_family=AF_INET6, sin6_port=htons(6060), inet_pton(AF_INET6, "face:b00c:1234:5678::abcd", &sin6_addr), sin6_flowinfo=0, sin6_scope_id=0}, 128) = 0 502 connect(10, {sa_family=AF_INET6, sin6_port=htons(6060), inet_pton(AF_INET6, "face:b00c:1234:5678::abcd", &sin6_addr), sin6_flowinfo=0, sin6_scope_id=0}, 128) = 0 # fg tcpdump -pn -i lo -w connect.pcap 2> /dev/null # tcpdump -r connect.pcap -n tcp | cut -c 1-72 reading from file connect.pcap, link-type EN10MB (Ethernet) 17:57:40.383533 IP 127.0.0.4.56068 > 127.0.0.1.4444: Flags [S], seq 1333 17:57:40.383566 IP 127.0.0.1.4444 > 127.0.0.4.56068: Flags [S.], seq 112 17:57:40.383589 IP 127.0.0.4.56068 > 127.0.0.1.4444: Flags [.], ack 1, w 17:57:40.384578 IP 127.0.0.1.4444 > 127.0.0.4.56068: Flags [R.], seq 1, 17:57:40.403327 IP6 ::6.37458 > ::1.6666: Flags [S], seq 406513443, win 17:57:40.403357 IP6 ::1.6666 > ::6.37458: Flags [S.], seq 2448389240, ac 17:57:40.403376 IP6 ::6.37458 > ::1.6666: Flags [.], ack 1, win 342, opt 17:57:40.404263 IP6 ::1.6666 > ::6.37458: Flags [R.], seq 1, ack 1, win Signed-off-by: Andrey Ignatov Signed-off-by: Alexei Starovoitov Signed-off-by: Daniel Borkmann --- tools/include/uapi/linux/bpf.h | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) (limited to 'tools/include/uapi') diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index f2120c5c0578..71051d01e8dd 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -150,6 +150,8 @@ enum bpf_attach_type { BPF_SK_MSG_VERDICT, BPF_CGROUP_INET4_BIND, BPF_CGROUP_INET6_BIND, + BPF_CGROUP_INET4_CONNECT, + BPF_CGROUP_INET6_CONNECT, __MAX_BPF_ATTACH_TYPE }; @@ -744,6 +746,13 @@ union bpf_attr { * @flags: reserved for future use * Return: SK_PASS * + * int bpf_bind(ctx, addr, addr_len) + * Bind socket to address. Only binding to IP is supported, no port can be + * set in addr. + * @ctx: pointer to context of type bpf_sock_addr + * @addr: pointer to struct sockaddr to bind socket to + * @addr_len: length of sockaddr structure + * Return: 0 on success or negative error code */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -809,7 +818,8 @@ union bpf_attr { FN(msg_redirect_map), \ FN(msg_apply_bytes), \ FN(msg_cork_bytes), \ - FN(msg_pull_data), + FN(msg_pull_data), \ + FN(bind), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call -- cgit v1.2.3 From 1d436885b23bf4474617914d7eb15e039c83ed99 Mon Sep 17 00:00:00 2001 From: Andrey Ignatov Date: Fri, 30 Mar 2018 15:08:08 -0700 Subject: selftests/bpf: Selftest for sys_bind post-hooks. Add selftest for attach types `BPF_CGROUP_INET4_POST_BIND` and `BPF_CGROUP_INET6_POST_BIND`. The main things tested are: * prog load behaves as expected (valid/invalid accesses in prog); * prog attach behaves as expected (load- vs attach-time attach types); * `BPF_CGROUP_INET_SOCK_CREATE` can be attached in a backward compatible way; * post-hooks return expected result and errno. Example: # ./test_sock Test case: bind4 load with invalid access: src_ip6 .. [PASS] Test case: bind4 load with invalid access: mark .. [PASS] Test case: bind6 load with invalid access: src_ip4 .. [PASS] Test case: sock_create load with invalid access: src_port .. [PASS] Test case: sock_create load w/o expected_attach_type (compat mode) .. [PASS] Test case: sock_create load w/ expected_attach_type .. [PASS] Test case: attach type mismatch bind4 vs bind6 .. [PASS] Test case: attach type mismatch bind6 vs bind4 .. [PASS] Test case: attach type mismatch default vs bind4 .. [PASS] Test case: attach type mismatch bind6 vs sock_create .. [PASS] Test case: bind4 reject all .. [PASS] Test case: bind6 reject all .. [PASS] Test case: bind6 deny specific IP & port .. [PASS] Test case: bind4 allow specific IP & port .. [PASS] Test case: bind4 allow all .. [PASS] Test case: bind6 allow all .. [PASS] Summary: 16 PASSED, 0 FAILED Signed-off-by: Andrey Ignatov Signed-off-by: Alexei Starovoitov Signed-off-by: Daniel Borkmann --- tools/include/uapi/linux/bpf.h | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'tools/include/uapi') diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 71051d01e8dd..9d07465023a2 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -152,6 +152,8 @@ enum bpf_attach_type { BPF_CGROUP_INET6_BIND, BPF_CGROUP_INET4_CONNECT, BPF_CGROUP_INET6_CONNECT, + BPF_CGROUP_INET4_POST_BIND, + BPF_CGROUP_INET6_POST_BIND, __MAX_BPF_ATTACH_TYPE }; @@ -947,6 +949,15 @@ struct bpf_sock { __u32 protocol; __u32 mark; __u32 priority; + __u32 src_ip4; /* Allows 1,2,4-byte read. + * Stored in network byte order. + */ + __u32 src_ip6[4]; /* Allows 1,2,4-byte read. + * Stored in network byte order. + */ + __u32 src_port; /* Allows 4-byte read. + * Stored in host byte order + */ }; #define XDP_PACKET_HEADROOM 256 -- cgit v1.2.3